Biocompatibility and gelation of chitosan-glycerol phosphate hydrogels

The aim of this study was to evaluate the cytotoxicity and gelation of thermosensitive chitosan-beta-glycerol phosphate (GP) solutions, which undergo sol-gel transition around body temperature. Chitosan 0.5-2% (w/v) mixed with GP 5-20% (w/v) solutions all gel at 37 degrees C and possess pH around the physiological range. High GP and chitosan concentrations result in faster gelation time. Extracts of all chitosan concentrations mixed with or without 5% (w/v) GP and 2% (w/v) chitosan combined with 10% (w/v) GP demonstrated up to 34% increase in proliferation rate of goat bone marrow derived mesenchymal stem cells when compared with control medium. Extracts from all other chitosan-GP combinations resulted in reduced cell proliferation relative to control medium. Increasing GP content in the gel resulted in a linear increase in the osmolality of the extracts in contact with the gels. The results of this study indicate that chitosan-GP is a biocompatible hydrogel, extracts of which can stimulate mesenchymal stem cell proliferation at certain concentrations. This material is therefore a promising vehicle for cell encapsulation and injectable tissue-engineering applications.     

Vestibular thresholds for yaw rotation about an earth-vertical axis as a function of frequency

Perceptual direction detection thresholds for yaw rotation about an earth-vertical axis were measured at seven frequencies (0.05, 0.1, 0.2, 0.5, 1, 2, and 5 Hz) in seven subjects in the dark. Motion stimuli consisted of single cycles of sinusoidal acceleration and were generated by a motion platform. An adaptive two-alternative categorical forced-choice procedure was used. The subjects had to indicate by button presses whether they perceived yaw rotation to the left or to the right. Thresholds were measured using a 3-down, 1-up staircase paradigm. Mean yaw rotation velocity thresholds were 2.8 deg s⁻¹ for 0.05 Hz, 2.5 deg s⁻¹ for 0.1 Hz, 1.7 deg s⁻¹ for 0.2 Hz, 0.7 deg s⁻¹ for 0.5 Hz, 0.6 deg s⁻¹ for 1 Hz, 0.4 deg s⁻¹ for 2 Hz, and 0.6 deg s⁻¹ for 5 Hz. The results show that motion thresholds increase at 0.2 Hz and below and plateau at 0.5 Hz and above. Increasing velocity thresholds at lower frequencies qualitatively mimic the high-pass characteristics of the semicircular canals, since the increase at 0.2 Hz and below would be consistent with decreased gain/sensitivity observed in the VOR at lower frequencies. In fact, the measured dynamics are consistent with a high pass filter having a threshold plateau of 0.71 deg s^-1 and a cut-off frequency of 0.23 Hz, which corresponds to a time constant of approximately 0.70 s. These findings provide no evidence for an influence of velocity storage on perceptual yaw rotation thresholds.

Coronary artery bypass grafting in patients with low ejection fraction: the effect of intra-aortic balloon pump insertion on early outcome

Background: Survival benefit with intra-aortic balloon pump (IABP) insertion for coronary artery bypass grafting (CABG) patients with left ventricular dysfunction is controversial. The aim of this study was to assess the early results of CABG that predict 30-day mortality and prolonged length of hospital stay (LOS) after isolated CABG and the role of IABP application as a main predictor in patients with an ejection fraction (EF) of 30% or less. Materials and Methods: Eight hundred and thirty-three patients who underwent isolated CABG with EF 30% as the control group. Demographic and clinical characteristics and postoperative complications were considered. Data were analyzed using the student's t-test and chi-square test for univariate analysis and the analysis of covariance and logistic regression for multivariate analysis. Results: The thirty-day mortality rate (1.6% vs. 0.7%, P P P = 0.002) and prolonged LOS (P = 0.009). Also, urinary tract infection, prolonged ventilation, and renal failure as postoperative complications were statistically more in the group with the application of IABP. Conclusion: Low ejection fraction can positively affect thirty-day mortality and prolonged LOS and ICU stay in patients who undergo CABG. In these patients, IABP insertion is a strong predictor for early complication and mortality.     

Diagnosis of colon cancer by attenuated total reflectance-fourier transform infrared microspectroscopy and soft independent modeling of class analogy

This study tries to demonstrate that attenuated total reflectance-fourier transform infrared (ATR-FTIR) microspectroscopy in combination with chemometric methods can reliably distinguish malignant colon tissues from healthy ones. It is important to explore a noninvasive and rapid method for detection of colon cancer biopsies. Initially, principal component analysis was applied to examine the degree of separation between tissue samples. Soft independent modeling of class analogy (SIMCA) was also employed to evaluate the prediction accuracy of ATR-FTIR microspectroscopy for the diagnosis of colon cancer. There were significant differences in the fourier transform infrared spectra of normal and cancerous colon biopsies in the 1,800–900 cm⁻¹ spectral region. The SIMCA results demonstrated that the accuracy, specificity, and sensitivity of the proposed diagnostic method were 93.3, 100, and 88.2%, respectively, which could help satisfy clinical diagnostic requirements.     

Fournier's gangrene after missed acute perforated appendicitis: A case report

Fournier''s gangrene (FG) is a rare progressive necrotizing fasciitis (NF) with high mortality rate. This case report describes a young patient with FG with no known history of disease or invasive therapeutic interventions.     

Bardet‐Biedl syndrome type 3 in an Iranian family: Clinical study and confirmation of disease localization

Bardet‐Biedl syndrome (BBS) is a group of autosomal recessive MCA/MR syndromes characterized by pigmentary retinopathy, postaxial polydactyly, hypogenitalism, obesity, and mental retardation. Five BBS loci have been identified; among them, BBS type 1 (BBS1) and type 3 (BBS3) are most common and most rare, respectively. We encountered an Iranian family that had seven affected members. All patients had a history of mild to severe obesity, but it was reversible in some patients by caloric restriction and exercise. All patients had pigmentary retinopathy, beginning as night blindness in early childhood and progressing toward severe impairment of vision by the end of the second decade. Polydactyly varied in limb distribution, ranging from four‐limb involvement to random involvement or even to nonaffectedness. Six of the seven patients were not mentally retarded. Although kidney anomaly or an adrenal mass was pres‐ ent in two patients, the fact that one patient had seven children rules out reproductive dysfunction. Linkage analysis with microsatellite markers showed that the disease in the family was assigned to a region around marker loci at 3p13‐p12 (maximum LOD score = 4.15 and recombination fraction θ = 0, at D3S1603 microsatellite marker), to which the BBS3 locus has been mapped. Haplotype analysis did not reduce the extent of the previously reported critical region of BBS3. A comparison of clinical manifestations of our patients with those of previously reported BBS3 patients did not support any type‐specific phenotypes, though manifestations in our patients are similar to those in BBS3 patients of a family in Newfoundland. Am. J. Med. Genet. 94:433–437, 2000. © 2000 Wiley‐Liss, Inc.     

Beneficial effects of quercetin on sperm parameters in streptozotocin‐induced diabetic male rats

Quercetin (QR) is a strong antioxidant and has been shown to reduce oxidative stress in the long‐term treatment of streptozotocin (STZ)‐induced diabetes in animal models. Antioxidants have significant effects on spermatogenesis, sperm biology and oxidative stress, and changes in antioxidant capacity are considered to be involved in the pathogenesis of chronic diabetes mellitus. The present study aims to examine the influence of QR on spermatogenesis in STZ‐induced diabetes in male Wistar rats. Animals (n = 50) were allocated into five groups: Group 1: Control rats given 0.5 ml of 20% glycerol in 0.9% normal saline. Group 2: Control rats given buffer (pH4.0).Group 3: diabetic controls. Group 4: rats given QR 15 mg/kg/day (i.p.). Group 5: STZ + QR rats. Animals were kept in standard conditions. At the end of the experiment (28th day), blood samples were taken for determination of testosterone, total antioxidant capacity, and levels of malondialdehyde and oxidized low‐density lipoprotein. All rats were euthanized, testes were dissected out and spermatozoa were collected from the epididymis for analysis. Sperm numbers, percentages of sperm viability and motility, and total serum testosterone increased significantly in QR‐treated diabetic rats (P < 0.05) compared with control groups. In histopathology, degeneration and inflammation in testes cells associated with diabetes were improved and testes weights in the QR‐treated diabetic group decreased significantly in comparison with controls (P < 0.05). We conclude that QR has significant beneficial effects on the sperm viability, motility, and serum total testosterone and could be effective for maintaining healthy sperm parameters and male reproductive function in diabetic rats. Copyright © 2010 John Wiley & Sons, Ltd.     

Association between serum inflammatory parameters and the disease severity in COVID‐19 patients

ObjectiveMost patients infected with the novel coronavirus (SARS‐CoV‐2), as the causative agent of COVID‐19 disease, show mild symptoms, but some of them develop severe illness. The purpose of this study was to analyze the blood markers of COVID‐19 patients and to investigate the correlation between serum inflammatory cytokines and the disease severity.MethodsIn this prospective cross‐sectional study, 50 patients with COVID‐19 and 20 patients without COVID‐19 were enrolled. According to ICU admission criteria, patients were divided into two groups of non‐severe and severe. Differences in the serum levels of C‐reactive protein (CRP), IL‐6, and TNF‐α, as well as erythrocyte sedimentation rate (ESR), lymphocytes (LYM) count, and neutrophils (NEU) count between the two groups were determined and analyzed.ResultsOut of the 50 patients with COVID‐19, 14 were diagnosed as severe cases. There was no significant difference between the two groups of COVID‐19 patients in terms of gender and age. Blood tests of COVID‐19 patients showed a significant decrease and increase in NEU and LYM counts, respectively. There were significant differences in the serum levels of IL‐6, TNF‐α, and CRP between the severe and non‐severe groups, which were higher in the severe group.Also, there was a significant correlation between the disease severity and CRP with ESR (r = 0.79), CRP with IL‐6 (r = 0.74), LYM with NEU (r = −0.97), and ESR with TNF‐α (r = 0.7).ConclusionThe findings of this study, as the first study in Iran, suggest that the levels of IL‐6, TNF‐α, ESR, and CRP could be used to predict the severity of COVID‐19 disease.