Endosulfan splenic pathology and amelioration by vitamin C in New Zealand rabbit

Endosulfan, a chlorinated hydrocarbon insecticide/acaricide, is a member of a cyclodiene sub-group of poisons to a wide variety of insects and mites. It is also toxic to humans and animals, but there is limited knowledge about endosulfan-related splenic and overall immunotoxicity. The aim of this study was to review pathological findings of endosulfan toxicity in the spleen and to examine potential protective effects of the anti-oxidant Vitamin C (Vit C). Here, after 6-week exposures, the spleens of New Zealand White rabbits were examined grossly and histopathologically and tissue caspase-3 activity was assessed immunohistochemically. Rabbits in four groups were used: Group END were given by oral gavage a sub-lethal dose of endosulfan (1?mg/kg) in corn oil daily for 6 weeks; Group END?+?C received the same dose of endosulfan daily and Vit C (20?mg/kg) every other day by gavage during this period; Group Vit C received oral corn oil daily and 20?mg/kg Vit C every other day; and Group OIL received corn oil daily for 6 weeks. Analyses of the tissues collected 1 week after the final dosing revealed lymphocyte depletion and necrosis in spleens of the hosts that received the pesticide (END only and END?+?C); hemorrhage and slight neutrophilic infiltration was also noted. Caspase-3 immunoreactivity was marked in lymphocytes in all spleens of rabbits in both END groups. Overall, these toxicities were mitigated by Vit C co-treatment; in END?+?C hosts, markedly decreased depletion of lymphocytes, inflammation and caspase-3 immunoreactivity were observed. However, even with mitigation, the level of toxicity present was still greater than any seen in the spleens of hosts that received OIL or Vit C alone. These results revealed endosulfan could cause toxicity in the rabbit spleen, characterized by depletion of lymphocytes, inflammation, necrosis and hemorrhage, and that this toxicity could begin to be mitigated by Vit C co-treatment.     

Clinico-hematological and micronuclear changes induced by cypermethrin in broiler chicks: Their attenuation with vitamin E and selenium

This study was carried out on 90 one-day-old broiler chicks to know clinico-hematological alterations, DNA damage caused by cypermethrin (CY), and attenuation of toxic effects by vitamin E (Vit E) and selenium (Se). Birds were randomly divided into five equal groups. Groups 1–4 received CY (600 ml kg^?1 b.wt) daily for 30 days by crop tubing. In addition to CY, groups 2, 3 and 4 received Vit E (150 mg kg^?1 b.wt), Se (0.25 mg kg^?1 b.wt), and Vit E (150 mg kg^?1 b.wt)+Se (0.25 mg kg^?1 b.wt), respectively. Group 5 served as control. Birds were monitored twice daily for clinical signs. They were weighed and blood samples were collected at experimental days 10, 20 and 30 for hematological studies. CY-treated birds showed more prominent signs of toxicity compared to CY+Vit E, CY+Se and CY+Vit E+Se birds. Body weight in groups 1–3 was significantly (P<0.05) smaller at days 20 and 30 when compared with the control group. Significantly (P<0.001) higher numbers of micronuclei appeared in chicks treated with CY compared to CY+Vit E- and CY+Se-treated birds. Significantly decreased total erythrocyte counts (TEC), hemoglobin (Hb) concentration and packed cell volume (PCV) in all treated groups were recorded. Treated birds suffered from macrocytic hypochromic anemia. Leukocytosis in early stage and later leucopenia was seen in treated birds. It can be concluded that CY induces toxic effects in broilers chicks; however, these toxic effects can be ameliorated by Vit E or Se. Combination of Vit E and Se was more effective to ameliorate toxic effects of cypermethrin.     

Effects of a continuous-combined regimen of low-dose hormone therapy (oestradiol and norethindrone acetate) and tibolone on the quality of life in symptomatic postmenopausal women: A double-blind,randomised study

ObjectiveThis study compared the effects of a continuous-combined regimen of low-dose hormone therapy (LD-HT) versus tibolone and supplemental calcium/vitamin D3 (control) on quality of life (QoL) in symptomatic postmenopausal women.DesignThis study was a prospective, randomised, double-blind, comparative trial with a control group.SettingThe study was conducted in a climacteric outpatient clinic in the University Hospital of Federal University of Juiz de Fora, Brazil.PopulationA total of 174 postmenopausal women under 60 years of age who attended the climacteric outpatient clinic between June 2009 and June 2011 were recruited. These women complained of moderate or intense vasomotor symptoms and exhibited no contraindications for the use of hormone therapy.InterventionsThe patients were randomised into three groups: (1) daily treatment with 2.5 mg tibolone (n = 64), (2) 50 mg calcium carbonate + 200 IU vitamin D3 (Ca/Vit D3, n = 54) or (3) 1 mg oestradiol + 0.5 mg norethindrone acetate (E2/NETA, n = 56) for 12 weeks.Primary outcome measuresThe primary outcome was the evaluation of QoL using the Women's Health Questionnaire (WHQ) in all subjects at baseline and after 4, 8 and 12 weeks of treatment.ResultsA total of 130 women in the following groups completed the study: tibolone (n = 42), Ca/Vit D3 (n = 44) and E2/NETA (n = 44). An improved QoL based on the WHQ was observed at T0 (80.12 ± 14.04, 77.73 ± 15.3, 77.45 ± 15.4) and T12 (57.0 ± 15.5, 55.7 ± 16.7, 58.4 ± 12.6) for the tibolone, E2 + NETA and Ca/Vit D3 groups, respectively (p values <0.05). The three groups exhibited significantly different scores at T12 for sexual behaviour and vasomotor symptoms. The tibolone group exhibited better sexual function compared with the E2/NETA and Ca/Vit D3 groups (4.2 ± 26, 5.6 ± 2.8, 5.4 ± 2.8, respectively, p values <0.05). LD-HT was superior to tibolone and Ca/Vit D3 treatment for improvements in vasomotor symptoms (3.2 ± 1.5, 4.0 ± 1.8, 4.3 ± 2.0, respectively, p values <0.05). Adverse effects were few and mild.ConclusionsAn improved QoL was observed in the three study groups. Tibolone primarily improved sexual function, and E2/NETA exhibited a superior response for vasomotor symptoms.     

Toxico-pathological changes induced by cypermethrin in broiler chicks: Their attenuation with Vitamin E and selenium

Ninety 1-day old broiler chicks of mixed gender (as hatched) procured from a local hatchery were randomly divided into five equal groups. All the treatments were given through crop tubing. Groups 1–4 received cypermethrin (CY) (600 mg kg^?1 b. wt.) daily for 30 days. In addition to CY (group 1), groups 2–4 received Vit E (150 mg kg^?1 b. wt.), Se (0.25 mg kg^?1 b. wt.), and Vit E (150 mg kg^?1 b. wt.)+Se (0.25 mg kg^?1 b. wt.), respectively. Group 5 served as control andreceived normal saline (2 ml kg^?1 b. wt.) for 30 days. Randomly selected six broiler chicks from each group were slaughtered at experimental days 10, 20 and 30 for the collection of serum/plasma and morbid tissues. Absolute organ weights were recorded. Total plasma proteins, fibrinogen and creatinine were significantly (P<0.05) increased while alkaline phosphatase (ALP), lactate dehydrogenase (LDH) and urea decreased significantly (P<0.05) in CY-treated group when compared with the control group. Kidneys were swollen grossly in treated broiler chicks. In liver, necrosis of hepatocytes, cytoplasmic vacuolation, bile duct hyperplasia and mononuclear cellular infiltration were observed. In kidneys, necrosis of tubular epithelial cells, cytoplasmic vacuolation, cellular infiltration and atrophy of glomeruli were observed. Sub-arachnoid space was much dilated in CY-treated broiler chicks. It can be concluded that CY induces biochemical and histopathological alterations in broilers chicks; however, these toxic effects can be ameliorated by Vit E or Se. Combination of Vit E and Se was more effective in ameliorating toxic effects of cypermethrin in broilers chicks.     

l-Arginine supplementation enhances eNOS expression in experimental model of hypercholesterolemic rabbits aorta

Introduction: Diminished bioavailability of nitric oxide is crucial in endothelial dysfunction and the development of atherosclerosis. Several studies have found that l-arginine as a nitric oxide (NO) donor has beneficial effect in prevention of atherosclerosis, but the mechanism is not completely known. We hypothesized that increased endothelial nitric oxide synthase (eNOS) and/or decreased inducible NOS (iNOS) expressions might be involved in the preventive effects of l-arginine in hypercholesterolemic rabbits. Methods: Seventeen male rabbits were divided randomly in two groups. They received rabbits chow supplemented with 1% cholesterol (group 1, n = 8) and the other group received also l-arginine (3% in drinking water) (group 2, n = 9) for 1 month. Blood samples were obtained before and after the experiment. At the end of experiment, the aortas were harvested. The serum levels of cholesterol and low-density lipoproteins (LDL) were measured. The intima/media thickness (IMT) ratio was measured and the determination of fatty streak formation was done with the aid of light microscopy. eNOS and iNOS expression in aorta were studied with immuohistochemistery. Results: The IMT ratio in first group having fatty streaks was 0.287 ± 0.15. No fatty streak lesion was detected in l-arginine-treated group. The results also indicated that eNOS expression (intensity) in aortas was significantly higher in l-arginine-treated group (group 1: 13.62 ± 2.7 and group 2: 21.77 ± 2.8; p < 0.05), but no significant difference was observed for iNOS expression between the groups. Conclusion: The expression of eNOS plays an important role in the protection of the vessel wall from atherosclerosis. l-Arginine in drinking water has a beneficial effect in the enhancement of eNOS protein expression.     

Role of vitamin C and selenium in attenuation of nicotine induced oxidative stress,P53 and Bcl2 expression in adult rat spleen

Forty adult female rats were randomly divided into four groups: control, nicotine, nicotine + vitamin C and nicotine + selenium group. Splenic tissues concentrations of thiobarbituric acid reactive substances (TBARS), nitric oxide, superoxide dismutase (SOD) and catalase (CAT) activities were measured. The P53 and Bcl2 proteins were detected by Western blot and their expression in splenic tissues were measured by quantitative real time PCR in all groups. Compared to control group, nicotine increased the concentrations of TBARS and nitric oxide significantly. However, Vit. C or Se supplementation with nicotine caused a significant decrease in these concentrations. SOD and CAT activities of nicotine group decreased significantly compared to control group. Treatment with Vit. C or Se plays a significant role in elevation of SOD and CAT activities. In splenic tissues, nicotine significantly decreases the protein levels and the mRNA expression of P53 and increases the protein levels of Bcl2 and its expression. Administration of Vit. C. to nicotine-treated rats completely reversed the decrease in P53 levels and its mRNA expression and the increase in Bcl2 levels and its mRNA expression to the control values. In contrast, Se administration did not induce any significant changes in these genes levels or expressions compared to nicotine group. Conclusion: Vit. C supplementation to nicotine treated rats was more effective than selenium in attenuation of nicotine-induced oxidative stress, p53 and Bcl2 expression in rat spleen tissues.     

Dichlorvos-induced testicular toxicity in male rats and the protective role of vitamins C and E

Dichlorvos is an organophosphorus insecticide that is used worldwide for pest control in agriculture and household use. Vitamins C and E are potential antioxidants protecting cells from oxidative stress. Vitamin C + vitamin E, dichlorvos, a combination of vitamin C + vitamin E + dichlorvos, or corn oil (control) were given to rats via oral gavage for 7 weeks. Body and testis weights, sperm parameters, hormone levels, histo- and cytopathological changes in testes were investigated at the end of 24 h and the 4th and 7th weeks comparatively with the control group. Body and testis weights, sperm morphology, FSH, LH, and testosterone levels were decreased significantly at the end of 4th and 7th weeks in the dichlorvos- and vitamins + dichlorvos-treated groups. A statistically significant decline in sperm motility and testosterone levels occurred by the end of 7th week in the dichlorvos- and vitamins + dichlorvos-treated groups. Light and electron microscopy revealed necrosis, edema and cellular damage in testicular tissues of the dichlorvos- and vitamins + dichlorvos-treated rats at the end of 4th and 7th weeks. In conclusion, dichlorvos caused subacute and subchronic reproductive toxicity, but vitamins did not confer protection.     

Quantitative analysis of liver fibrosis in rats with shearwave dispersion ultrasound vibrometry: Comparison with dynamic mechanical analysis

Ultrasonic elastography, a non-invasive technique for assessing the elasticity properties of tissues, has shown promising results for disease diagnosis. However, biological soft tissues are viscoelastic in nature. Shearwave dispersion ultrasound vibrometry (SDUV) can simultaneously measure the elasticity and viscosity of tissue using shear wave propagation speeds at different frequencies. In this paper, the viscoelasticity of rat livers was measured quantitatively by SDUV for normal (stage F0) and fibrotic livers (stage F2). Meanwhile, an independent validation study was presented in which SDUV results were compared with those derived from dynamic mechanical analysis (DMA), which is the only mechanical test that simultaneously assesses the viscoelastic properties of tissue. Shear wave speeds were measured at frequencies of 100, 200, 300 and 400 Hz with SDUV and the storage moduli and loss moduli were measured at the frequency range of 1–40 Hz with DMA. The Voigt viscoelastic model was used in the two methods. The mean elasticity and viscosity obtained by SDUV ranged from 0.84 ± 0.13 kPa (F0) to 1.85 ± 0.30 kPa (F2) and from 1.12 ± 0.11 Pa s (F0) to 1.70 ± 0.31 Pa s (F2), respectively. The mean elasticity and viscosity derived from DMA ranged from 0.62 ± 0.09 kPa (F0) to 1.70 ± 0.84 kPa (F2) and from 3.38 ± 0.32 Pa s (F0) to 4.63 ± 1.30 Pa s (F2), respectively. Both SDUV and DMA demonstrated that the elasticity of rat livers increased from stage F0 to F2, a finding which was consistent with previous literature. However, the elasticity measurements obtained by SDUV had smaller differences than those obtained by DMA, whereas the viscosities obtained by the two methods were obviously different. We suggest that the difference could be related to factors such as tissue microstructure, the frequency range, sample size and the rheological model employed. For future work we propose some improvements in the comparative tests between SDUV and DMA, such as enlarging the harmonic frequency range of the shear wave to highlight the role of viscosity, finding an appropriate rheological model to improve the accuracy of tissue viscoelasticity estimations.     

In vitro stability of open wedge high tibial osteotomy with synthetic bone graft

It has been predicted that significant stress will be applied to the plate and lateral cortical hinge of an osteotomy site when early full weight bearing is commenced after an open wedge high tibial osteotomy. We hypothesized that the stress concentration on the plate or at the lateral cortical hinge would be reduced by inserting bone substitutes into the osteotomy gap. Two different types of tibia model were investigated: Group A, fixation with TomoFix with the osteotomy site left as an open space; and Group B, two β-TCP wedges are inserted into osteotomy site and fixed with TomoFix. Stress at five points was measured using strain gauges. Specimens were mounted onto a testing machine with an FTA (femoro-tibial angle) of 170°. Cyclic load tests and an ultimate load test were then performed. The mean stress on the plate was measured at 15.5 ± 1.8 Mpa in Group A. On the other hand, this value in Group B was only 9.52 ± 2.1 Mpa and this was a significant difference (P < 0.01). The mean stress on the lateral hinge in Groups A and B was 3.31 ± 0.5 and 2.49 ± 0.2, respectively which was also a significant difference (P < 0.05). The mean maximum breaking load in Group A was 2500 ± 280 N and in Group B 4270 ± 420 N which was a significant difference (P < 0.01). Hence, for OWHTO procedures, the use of β-TCP wedges and TomoFix is thus likely to improve the initial axial and possibly rotational stability at the osteotomy site in comparison with methods that leave the osteotomy gap open.     

Preparation and characterization of collagen-based ADSC-carrier sheets for cardiovascular application

The use of scaffolds composed of natural biodegradable matrices represents an attractive strategy to circumvent the lack of cell engraftment, a major limitation of stem cell therapy in cardiovascular diseases. Bovine-derived non-porous collagen scaffolds with different degrees of cross-linking (C0, C2, C5 and C10) were produced and tested for their mechanical behavior, in vitro biocompatibility with adipose-derived stem cells (ADSCs) and tissue adhesion and inflammatory reaction. Uniaxial tensile tests revealed an anisotropic behavior of collagen scaffolds (2 × 0.5 cm) and statistically significant differences in the mechanical behavior between cross-linked and non-cross-linked scaffolds (n = 5). In vitro, ADSCs adhered homogenously and showed a similar degree of proliferation on all four types of scaffolds (cells × 10³ cm^?2 at day 7: C0: 94.7 ± 37.1; C2: 91.7 ± 25.6; C5: 88.2 ± 6.8; C10: 72.8 ± 10.7; P = n.s.; n = 3). In order to test the in vivo biocompatibility, a chronic myocardial infarction model was performed in rats and 1.2 × 1.2 cm size collagen scaffolds implanted onto the heart 1 month post-infarction. Six animals per group were killed 2, 7 and 30 days after transplant. Complete and long-lasting adhesion to the heart was only observed with the non-cross-linked scaffolds with almost total degradation 1 month post-transplantation. After 7 and 30 days post-implantation, the degree of inflammation was significantly lower in the hearts treated with non-cross-linked scaffolds (day 7: C0: 10.2 ± 2.1%; C2: 16.3 ± 2.9%; C5: 15.9 ± 4.8%; C10: 17.4 ± 4.1%; P < 0.05 vs. C0; day 30: C0: 1.3 ± 1.3%; C2: 9.4 ± 3.0%; C5: 7.0 ± 2.1%; C10: 9.8 ± 2.5%; P < 0.01 vs. C0). In view of the results, the non-cross-linked scaffold (C0) was chosen as an ADSC-carrier sheet and tested in vivo. One week post-implantation, 25.3 ± 7.0% of the cells transplanted were detected in those animals receiving the cell-carrier sheet whereas no cells were found in animals receiving cells alone (n = 3 animals/group).We conclude that the biocompatibility and mechanical properties of the non-cross-linked collagen scaffolds make them a useful cell carrier that greatly favors tissue cell engraftment and may be exploited for cell transplantation in models of cardiac disease.     

Possible ameliorative effects of kolaviron against reproductive toxicity in sub-lethally whole body gamma-irradiated rats

Ionizing radiation is one of the environmental factors that may contribute to reproductive dysfunction by a mechanism involving oxidative stress. We investigated the possible ameliorative effects of kolaviron (KV) (a biflavonoid from the seeds of Garcinia kola) on sperm characteristics, testicular lipid peroxidation (LPO) and antioxidant status after a whole body γ-irradiation in Wistar rats. Vitamin C (VC) served as standard antioxidant in this study. The study consists of four groups of 6 rats each. Group I received corn oil, whereas group II received a single dose of γ-radiation (5 Gy). The animals in groups III and IV were pretreated with KV (250 mg/kg) and VC (250 mg/kg) by oral gavage five times in a week, respectively, for 6 weeks prior to and 8 weeks after exposure to γ-radiation. Gamma-irradiation resulted in a significant (p < 0.05) decrease in body weight and relative testes weight. Also, γ-irradiation significantly (p < 0.05) decreased the activities of superoxide dismutase, catalase and glutathione S-transferase as well as glutathione level, but markedly elevated malondialdehyde levels in the serum and testes. Irradiated rats showed testicular degeneration with concomitant decrease in sperm motility and viability. Although sperm abnormalities significantly increased, it has no effect on the epididymal sperm count. KV and VC significantly (p < 0.05) decreased the body weight loss and increased relative testes weights of the rats. Furthermore, supplementation of KV and VC ameliorated radiation-induced toxicity by increasing the activities of antioxidant enzymes, decreased LPO and abrogated testicular degeneration. Taken together, γ-irradiation caused reproductive dysfunction by depleting the antioxidant defence system in the rats, while administration of KV or VC ameliorated the radiation-induced testicular toxicity.     

Does flexion of the femoral implant in total knee arthroplasty increase knee flexion: A randomised controlled trial

IntroductionProsthetic and operative modifications in total knee arthroplasty (TKA) have been proposed to maximise post-operative knee flexion as it is essential in routine functional activities.MethodsWe performed a double blind randomised controlled trial to compare clinical outcomes of primary cruciate-retaining TKA for osteoarthritis with the femoral component implanted in either 4° flexion in the sagittal plane (F) or in a neutral position (C). The primary outcome of knee flexion and secondary outcomes knee extension, quadriceps strength, WOMAC, SF-12v2, timed stand test, stair climb test and satisfaction were assessed at 1 year. Knee flexion and extension were also assessed intra-operatively. Implant flexion was measured from true lateral radiographs.ResultsThirty-nine participants (40 knees) were recruited, 20 knees per group. Three subjects from the control group and two from the flexed group were lost to 1 year follow-up but numbers were sufficient to satisfy the sample size calculation. Significant differences were found between the groups in knee flexion (F: 113.6 ± 8.8° pre-operative, 122.4 ± 6.0° intra-operative, 110.2 ± 7.5° 1 year, C: 117.4 ± 11.7°, 117.4 ± 7.6°, 103.5 ± 10.7°. p = 0.031) and mental component score of the SF12-v2 (F 53.3 ± 13.2, C 61.1 ± 7.3, p = 0.009) but there were no significant differences in other outcomes and patients were equally satisfied.ConclusionFlexing the femoral implant in this cruciate retaining TKA system provided a significant difference in knee flexion compared to a neutral position. The improvement appears to occur predominantly at surgery and was not associated with a clinical or functional benefit at 1 year. (ACTRN12606000325505). Level of evidence: Level 1; randomised controlled trial.     

Effect of the immunosuppressive regimen on the incidence of cytomegalovirus infection in 378 heart transplant recipients: A single centre,prospective cohort study

BackgroundCytomegalovirus (CMV) infection is a major complication of immunosuppression after heart transplant. Recent studies suggest the actual immunosuppressive regimen may affect the risk of CMV infection.ObjectivesTo evaluate incidence, risk factors and clinical consequences of CMV infection and assess the possible differential effect of distinct immunosuppressive protocols.Study designSingle centre, prospective cohort study of 378 consecutive heart transplant recipients undergoing CMV monitoring. Preemptive treatment was the standard of care. Patients were grouped as follows: group A, without any CMV infection; group B, with CMV infection not requiring pre-emptive treatment; group C, treated for CMV infection or disease.ResultsMost recipients never required antiviral therapy because of no CMV infection/disease (group A, 31%) or CMV levels below the cut-off for pre-emptive treatment (group B, 28%). Group C recipients (41%) were significantly older than group A patients (49.1 ± 13.2 vs. 44.8 ± 15.1 years; p = 0.028). Most cases occurred within the second month post-transplant. CMV viremia was detected in 77% and 62% of patients primed with thymoglobulin or ATG Fresenius, respectively, (OR 2.06, 95% C.I. 1.27–3.34; p = 0.0034). Use of everolimus was associated with a significantly lower rate of CMV infection compared to azathioprine or mycophenolate (OR 0.19, 95% C.I. 0.09–0.39; p < 0.0001). Major opportunistic infections were significantly more common in groups B and C.ConclusionIn a large and homogeneous cohort of heart transplant recipients, we observed a strong relationship between the immune suppressive regimen and CMV infection, as well as an increased incidence of other opportunistic infections in recipients with CMV infection/disease.     

Linear and non-linear analysis of heart rate variability in master athletes and healthy middle-aged non-athletes

The present study examined the autonomic cardiac modulation of veteran athletes by the use of traditional and modern methods of heart rate variability (HRV) analysis. Twenty-nine healthy male master soccer players were divided into two groups; group A consisted of fourteen participants (age 48.9 ± 5.8 years), who were engaged to regular aerobic exercise and group B of fifteen sedentary ones (age 50.8 ± 5.7 years). Sixteen age-matched non-athletes formed control group C. All participants underwent ambulatory 24-h continuous electrocardiogram monitoring for the calculation of time and frequency domain HRV indices. Additionally, Poincaré analysis SD₁ and SD₂ as well as multiresolution wavelet analysis σ_wav(16) and σ_wav(32) markers were calculated. Time-domain indices were significantly increased in group A compared to groups B and C. Group A presented greater values of SD₁ (by 43%, p < 0.01 and 34.4%, p < 0.05 than groups B and C respectively) and SD₂ (by 26% compared to B and by 34.1% to C, p < 0.05). Index σ_wav(16) was higher in group A than in B and C by 35.6% (p < 0.01) and 23.5% (p < 0.05) respectively and so did σ_wav(32) by 22% (p < 0.05) and 24% (p < 0.05). Strong correlations were reported among indices. In conclusion, physically active master athletes attain better cardiac autonomic activity than sedentary counterparts, as proved by the application of Poincaré and multiresolution wavelet analyses, which can be useful research tools of cardiac autonomic modulation in sports cardiology.     

Role of left atrial speckle tracking echocardiography in predicting persistent atrial fibrillation electrical cardioversion success and sinus rhythm maintenance at 6 months

PurposeWe assessed the value of left atrium speckle tracking imaging (STI) indices, and clinical and other echocardiographic parameters in persistent atrial fibrillation (AF) patients to predict the efficacy of electrical cardioversion (EC) and sinus rhythm (SR) maintenance at 6 months.Material/methodsEighty persistent AF patients planned to receive EC, underwent echocardiography including STI. After 24 h, patients with successful EC were examined to predict SR maintenance. After 6 months patients with no AF recurrence in electrocardiogram (ECG) underwent 7-day ECG to exclude silent AF. Every AF > 1 min was a recurrence.ResultsSR restored in 61 patients, 19 unsuccessful. Prior use of statins (68.8% vs. 42.1%, p = 0.03) was the only factor, determined later by univariate analysis to be a significant EC success predictor (OR = 1.09, CL ± 95% 1.001–1.019, p < 0.03). Both groups received similar antiarrhythmics and had similar echocardiographic parameters. After 6 months, SR was maintained in 19 patients (31.1%, Group I); AF recurrences were registered in 42 patients (68.8%, Group II). In Group I, only the mitral valve deceleration time (MVDT) 224.18 ± 88.13 vs. 181.6 ± 60.6 in Group II, p = 0.04) and the dispersion of time to peak longitudinal strain (dTPLS) (86.0 ± 68.3 vs. 151.8 ± 89.6, p = 0.03) differed significantly. The univariate analysis revealed dTPLS as a significant predictor of SR maintenance.ConclusionHigh EC efficacy and frequent AF recurrences were observed. The dispersion of time to the maximal longitudinal strain (LS) of left atrial segments facilitated prediction of SR maintenance. The value of 7-day ECG monitoring for detection of arrhythmia after 6 months was limited.     

Suitability of DCPs with Screw Locking Elements to allow sufficient interfragmentary motion to promote secondary bone healing of osteoporotic fractures

This paper analyses the suitability of a system comprising a Dynamic Compression Plate (DCP) and Screw Locking Elements (SLEs) to allow sufficient interfragmentary motion to promote secondary bone healing in osteoporotic fractures.Four fixation systems were mounted on bone-simulating reinforced epoxy bars filled with solid rigid polyurethane foam. Group 1, used for comparison purposes, represents a system comprised of a Locking Compression Plate (LCP) and eight locking screws. Groups 2 and 3 represent a system comprised of a DCP plate with eight cortical screws and two SLEs placed on the screws furthest from (group 2) and nearest to (group 3) the fracture. Group 4 represents the system comprised of a DCP plate with SLEs placed on all eight cortical screws. Cyclic compression tests of up to 10,000 load cycles were performed in order to determine the parameters of interest, namely the stiffnesses and the interfragmentary motion of the various configurations under consideration. Tukey's multiple comparison test was used to analyse the existence or otherwise of significant differences between the means of the groups.At 10,000 cycles, interfragmentary motion at the far cortex for group 2 was 0.60 ± 0.04 mm and for group 3 0.59 ± 0.03 mm (there being no significant differences: p = 0.995). The mean interfragmentary motion at the far cortex of the LCP construct was 70% less than that of the two groups with 2SLEs (there being significant differences: p = 1.1 × 10^?8). In the case of group 4 this figure was 45% less than in groups 2 and 3 (there being significant differences: p = 5.6 × 10^?6). At 10,000 cycles, interfragmentary motion at the near cortex for group 2 was 0.24 ± 0.06 mm and for group 3 0.24 ± 0.03 mm (there being no significant differences: p = 1.000). The mean interfragmentary motion at the near cortex of the LCP construct was 70.8% less than that of the two groups with 2SLEs (there being significant differences: p = 0.011). In the case of group 4 this figure was 66.7% less than in groups 2 and 3 (there being significant differences: p = 0.016). The mean stiffness at 10,000 cycles was 960 ± 110 N mm^?1 for group 2 and 969 ± 53 N mm^?1 for group 3 (there being no significant differences: p = 1.000). For group 1 (the LCP construct) the mean stiffness at 10,000 cycles was 3144 ± 446 N mm^?1, 3.25 times higher than that of groups 2 and 3 (there being significant differences: p = 0.00002), and 1.6 times higher than that of the DCP + 8SLEs construct (1944 ± 408 N mm^?1, there being significant differences: p = 0.007).It is concluded that using the DCP + 2SLEs construct sufficient interfragmentary motion is ensured to promote secondary bone healing. However, if too many SLEs are used the result may be, as with the LCP, an excessively rigid system for callus formation.     

Undergraduate medical students. Simulation-based activity to conduct the informed consent process for health research studies

IntroductionTraining through medical simulation allows for continuous learning under controlled conditions. Simulation-based training activities can be used simultaneously with other educational strategies to strengthen the attitudinal skills needed to develop an informed consent process in the context of health research.ObjectiveTo facilitate learning in undergraduate medicine students, and to evaluate their competences to carry out an informed consent process in a scenario that resembles reality.Materials and methodsIn this semi-longitudinal study, a simulation-based activity was conducted with 136 medical students of the fourth (Group A) and fifth year (Group B) of the Marist University of Mérida, in southern Mexico.ResultsThe mean score for both groups was 72.48 ± 1.05 (95% CI = 70.4–74.5); 86.2 ± 0.96 (95% CI = 84.2–88.0); and 77.7 ± 0.72 (95% CI = 76.3–79.1), in the pre-test, the simulation and the post-test, respectively. The students of group A self-evaluated their performance with 3.93/5.00, and those of Group B, 4.04/5.00.DiscussionThis study showed that Group A students did not score lower on simulation-based activity when compared to students in Group B, suggesting that before the fifth year of undergraduate medical education, students could properly develop an informed consent-process for health research if they receive early education about medical ethics and research bioethics. Issues related to bioethics in human health research can be included as soon as medical students initiate research methodology courses.     

Hepatocellular proliferation and hepatocarcinogen bioactivation in mice with diet-induced fatty liver and obesity

Human liver cancer is in part associated with obesity and related metabolic diseases. The present study was undertaken in a mouse model of diet-induced obesity (DIO) and hepatic steatosis, conditions which can be associated with hepatic neoplasia, to determine whether the rates of cell proliferation or hepatocarcinogen bioactivation were altered in ways which could facilitate hepatocarcinogenesis. DIO mice were generated by feeding C57BL/6 (B6) male mice a high-fat diet beginning at 4 weeks of age; age-matched conventional lean (LEAN) B6 mice fed a low fat diet (10% Kcal from fat) were used for comparison. Groups of 28 week old DIO and LEAN mice were dosed with the bioactivation-dependent DNA-reactive hepatocarcinogen 2-acetylaminofluorene (AAF), at 2.24 or 22.4 mg/kg, given by gavage 3 times per week for 31 days, or received no treatment (DIO and LEAN control groups). Compared with the LEAN control group, the DIO control group had a higher mean body weight (16.5 g), higher mean absolute (1.4 g) and mean relative (25.5%) liver weights, higher (394%) liver triglyceride concentrations, and an increased incidence and severity of hepatocellular steatosis at the end of the dosing phase. The DIO control group also had a higher mean hepatocellular replicating fraction (31% increase, determined by proliferating cell nuclear antigen immunohistochemistry). Hepatocarcinogen bioactivation, based on formation of AAF DNA adducts as measured by nucleotide ³²P-postlabeling, was similar in both DIO and LEAN AAF-dosed groups. Thus, hepatocellular proliferation, but not hepatocarcinogen bioactivation, was identified as an alteration in livers of DIO mice which could contribute to their susceptibility to hepatocarcinogenesis.     

Biochemical and histopathological evaluation of histamine receptors (H1R,H2R,H3R and H4R)-agonist in rabbits

The present study was designed to investigate the biochemical and histopathological changes in the livers of rabbits treated with histamine and histamine receptors (H1R–H4R)-agonist. The cohort comprised of six groups containing five rabbits each. Control group received sterile distilled water (1 mL/kg × b.i.d.) and treated groups received subcutaneous histamine (100 μg/kg × b.i.d.) and H1R–H4R-agonist (histamine trifluoro-methyl toluidide, amthamine, R-[?]-α-methylhistamine, clobenpropit, respectively) each in a dose of 10 μg/kg × b.i.d. (12 h [8 am and 8 pm]) for 30 days. Hepatotoxicity due to these agonists was analyzed using biochemical and histopathological methods. Histamine and H1R–H3R-agonist were found to be hepatotoxic as shown by statistically significant (p < 0.05) elevated levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST), most marked in the H3R-agonist group. However, their levels in H4R-agonist group remained very similar to the control group. The entire drug treated groups as compared to control showed significant elevated levels of alkaline phosphatase (ALP). Histopathological examination revealed obvious changes in histamine, H2R- and H3R-agonist groups in terms of alteration of hepatic microstructure, congestion, focal necrosis and increased incidence of multinucleate hepatocytes while H1R and H4R groups showed minimal changes. From the findings of the present study it may be concluded that on repeated administration, histamine and HR-agonists-induced hepatotoxicity which is most pronounced with H3R-agonist though not severe enough to jeopardize the vital functions of liver and warrants further long-term studies.     

A prospective observational study to compare transfusion outcomes in ABO identical versus ABO non-identical single donor platelet concentrates: An experience from a tertiary healthcare center in India

ABO incompatible single donor platelet concentrates (SDPC) have a concern about unsatisfactory increments as well as possibility of hemolytic transfusion reaction. But from Indian population no study has commented on the clinical and laboratory outcome of ABO mismatched platelet transfusion. The aim of study was to compare transfusion outcomes in ABO identical versus ABO non-identical single donor platelet concentrates. In this prospective observational study, 400 SDPC transfusions among different patients were included. In group A (n = 200), ABO identical SDPC transfusions and in group B (n = 200) ABO non-identical SDPC transfusions were added. Corrective count increment (CCI), absolute count increment (ACI), percent platelet recovery (PPR) were calculated and incidents of hemolytic transfusion reactions were noted. In group A mean ± SD of ACI, CCI and PPR were as 30.78 ± 12.51, 15.10 ± 6.677, 39,948.9 ± 20,099.392. In group B, mean ± SD of ACI, CCI and PPR were – 25.4 ± 15.65, 12.509 ± 5.906, 33,559.2 ± 22,150.304. And when CCI, ACI, PPR were compared with group A and group B, statistically significant differences were noted (P < 0.05). There was statistically significant difference in CCI, ACI and PPR in oncology patients and other prophylactic recipients except patients with dengue and other infectious disease. But there was no hemolytic transfusion reaction noted in any group. Our study clearly establish the potential benefits of ABO-identical PLT transfusion. It also points out that in emergency conditions or when there is a paucity in inventory, ABO non-identical SDPC transfusion may be lifesaving and clinically significant.