Modulation of cutaneous reflexes in arm muscles during walking: further evidence of similar control mechanisms for rhythmic human arm and leg movements

Stimulation of cutaneous nerves innervating the hand evokes prominent reflexes in many arm muscles during arm cycling. We hypothesized that the mechanisms controlling reflex modulation during the rhythmic arm swing of walking would be similar to that documented during arm cycling. Thus, we expected cutaneous reflexes to be modulated by position in the walking cycle (phase dependence) and be different when walking compared to contraction while standing (task dependence). Subjects performed static postures similar to those occurring during walking and also walked on a treadmill while the superficial radial nerve was electrically stimulated pseudorandomly throughout the step cycle. EMG was recorded bilaterally from upper limb muscles and kinematic recordings were obtained from the elbow and shoulder joints. Step cycle information was obtained from force-sensing insoles. Analysis was conducted after averaging contingent upon the occurrence of stimulation in the step cycle. Phase-dependent modulation of cutaneous reflexes at early (~50–80 ms) and middle (~80–120 ms) latencies was observed. Coordinated bilateral reflexes were seen in posterior deltoid and triceps brachii muscles. Task dependency was seen in that reflex amplitude was only correlated with background EMG during static contraction (75% of comparisons for both early and middle latency reflexes). During walking, no significant relationship between reflex amplitude and background EMG level was found. The results show that cutaneous reflex modulation during rhythmic upper limb movement is similar to that seen during arm cycling and to that observed in leg muscles during locomotion. These results add to the evidence that, during cyclical movements of the arms and legs, similar neural mechanisms observed only during movement (e.g. central pattern generators) control reflex output. Electronic Publication     

Heparin in haemorrhagic infarction in cerebral venous sinus thrombosis

Morbidity and mortality in puerperal cerebral venous thrombosis (CVT) can be reduced by arresting the progression of thrombosis using heparin. However, conventional dose of heparin requires monitoring of coagulation parameters and carries a risk of haemorrhage. The present study involved 56 patients of puerperal CVT with CT evidence of haemorrhagic infarction. Twenty nine of these patients received low dose heparin till 30th post-partum day or symptomatic relief. Their clinical features and severity were similar to 27 patients who did not receive heparin. The mortality and morbidity at discharge was significantly less (P < 0.001) in heparin treated group. There were no haemorrhagic complications. Low dose heparin is safe and effective in cerebral venous thrombosis, even with haemorrhagic infarction.     

Cyclooxygenase-2 inhibition and experimental colitis: beneficial effects of phosphorothioated antisense oligonucleotide and meloxicam

BACKGROUND: The effects of cyclooxygenase-2 (cox-2) inhibition by a cox-2 selective antisense phosphorothioated oligonucleotide (AS) and meloxicam were examined in experimental colitis. METHODS: Colitis was induced by trinitrobenzenesulphonic acid (TNBS) and acetic acid (Hac) separately in male Sprague-Dawley rats. Both groups of animals were treated daily intraperitoneally with AS and a mismatched control oligo (CO) (3 mg/kg), and orally with meloxicam (7.5 mg/kg) 1 h before induction of colitis. The animals were killed on day 4 (Hac) and on day 5 (TNBS). Tissue samples from colon, ileum, liver, kidney and spleen were collected for mRNA, myeloperoxidase activity (MPO), prostaglandin E2 (PGE2) estimation and for histology, and blood samples for PGE2, thromboxane B2 (TxB2) and TNF-alpha. RESULTS: Both TNBS and Hac increased colonic MPO activity, PGE2 concentrations and infiltration of colonic wall by inflammatory cells. Serum levels of TNF-alpha were increased in both models, whereas PGE2 was increased only in TNBS colitis. Only meloxicam suppressed the level of PGE2 significantly below the basal level. The animals in both models also showed splenomegaly. The colitis-induced changes were significantly suppressed by the treatment of the test compounds but not by the CO. Cox-2 mRNA but not cox-1 was decreased by the AS, but not by meloxicam or in CO-treated colitic animals. CONCLUSION: The findings demonstrate comparable beneficial effects of the cox-2 selective antisense oligonucleotide and meloxicam, which seem to be mediated by a combined inhibition of both PGE2 and TNF-alpha in the present models of colitis.     

Platelet glycoprotein IIb/IIIa inhibition using eptifibatide with primary coronary stenting for acute myocardial infarction: a 30-day follow-up study.

The results of primary coronary stenting for acute myocardial infarction (AMI) have been reported to improve significantly with the concomitant administration of platelet glycoprotein IIb/IIIa inhibitor abciximab. There are, however, no data available with the use of eptifibatide, a more cost-effective, small-molecule GP IIb/IIIa blocker with a shorter half-life. In a prospective multicenter feasibility and efficacy study, we assigned 55 consecutive patients with AMI being taken up for primary stenting to receive eptifibatide just before the procedure (two boluses of 180 microg/kg 10 min apart and a 24-hr infusion of 2 microg/kg/min). Clinical outcomes were evaluated at 30 days after the procedure. The angiographic patency of the vessel with TIMI flow rates, TIMI myocardial perfusion (TMP) grade, and corrected TIMI frame counts were assessed at the end of procedure and before hospital discharge. At 30 days, the primary endpoint, a composite of death, myocardial infarction, and urgent target vessel revascularization (TVR) was seen in 12.7% of patients. The TIMI 3 and TMP grade 3 flow, which was seen in 93% and 86% of patient, respectively, at the end of the procedure, declined to 86% and 78%, respectively (P < 0.05) before hospital discharge. Corrected TIMI frame counts also decreased from 25.7 +/- 7.2 to 22.9 +/- 6.8 (P < 0.05). There were five (9.1%) instances of subacute thrombosis (SAT) presenting as AMI, needing urgent TVR in all, within 3-5 days of the primary procedure. No excessive bleeding complication, directly attributable to the use of eptifibatide, was observed. The study was terminated prematurely because of an unacceptable SAT rate. Administration of eptifibatide along with primary stenting for AMI is associated with a high TIMI 3 and TMP grade 3 flow acutely. However, these flows decline significantly before hospital discharge and lead to a high rate of SAT. The dosage and duration of infusion of eptifibatide in this setting needs further evaluation.     

Early activation of mucosal dendritic cells and macrophages in acute Campylobacter colitis and cholera: An in vivo study

Background and Aim: Macrophages and dendritic cells are closely related mononuclear phagocytic cells. Little is known about their in vivo role in acute intestinal bacterial infections in humans. We undertook to evaluate these cells in rectal mucosal biopsies of patients with acute colitis. Methods: All mucosal mononuclear phagocytic cells in rectal biopsies of patients with acute Campylobacter colitis (n = 5), shigellosis (n = 5), and cholera (n = 10) were evaluated ultrastructurally and compared with those in controls (n = 5). Results: Mononuclear phagocytic cells in the superficial rectal mucosa showed a higher prevalence of ultrastructural features of activation in Campylobacter colitis and cholera than in controls. A lower prevalence of features of activation with increased monocytes was seen in shigellosis. Cells with the ultrastructural morphology of activated dendritic cells constituted 41% and 45% of all mononuclear phagocytic cells in two of five patients with Campylobacter colitis and 4–22% of cells in four of 10 patients with cholera. Their presence in patients with Campylobacter colitis was associated with significant surface epithelial damage and prominent acute inflammatory changes in the mucosa. Conclusions: This is the first ultrastructural study to show activated macrophages and dendritic cells in vivo in acute Campylobacter colitis and cholera. Dendritic cell activation occurred early in the clinical course of these infections. Surface epithelial damage may play a role in the activation of dendritic cells.     

Comparative Study of Alveolar Bone Height and Implant Survival Rate Between Autogenous Bone Mixed with Platelet Rich Plasma Versus Venous Blood for Maxillary Sinus Lift Augmentation Procedure

Aim and Objectives

The aim of this study was to evaluate changes in alveolar bone height by means of radiographic examination and Straumann implant survival rate following maxillary sinus lift augmentation using autogenous bone in combination with platelet rich plasma (PRP) versus venous blood (VB).

Methods

Fifty patients requiring sinus lift augmentation procedure included in the study were divided into two groups (n = 25). During the procedure the sub antral sinus cavity was augmented using autogenous bone taken from mandibular ramus area and mixed with PRP in one group and autogenous bone mixed with VB in the other group. Orthopantomograms were taken preoperatively, immediate, at 6 months and 1 year postoperatively. Height of alveolar bone at the site of sinus augmentation was measured on the radiographs. One hundred and twenty-one Straumann dental implants were placed after healing period.

Results

Age of the patients in the study groups ranged from 36 to 69 years. Differences in mean values of bone height measurements recorded in the PRP series revealed significant differences among the three subgroups (P = 0.001). Significant differences were noted between immediate postop and 6 month (P < 0.01), immediate postop and year (P < 0.01). In the VB series also significant differences were revealed among the three subgroups (P = 0.0280). Significant differences were noted between immediate postop and 6 month (P < 0.05). Comparison of results of subgroups of the two series at the three intervals revealed significant differences at ‘immediate postop’ values (P = 0.0002) and ‘sixmon’ values (P = 0.0435). Differences between ‘year’ values were not significant. Two implants were lost in PRP group.

Conclusion

The results of this limited study reveals that both groups recorded a good increase in the alveolar bone height after sinus augmentation and showed no significant differences between these groups when compared to each other at 1 year postoperatively. When both sub groups compared with immediate postop to year, PRP group showed significant difference and blood group showed no significant difference.     

Larvicidal and pupicidal activities of ecbolin A and ecbolin B isolated from Ecbolium viride (Forssk.) Alston against Culex quinquefasciatus Say (Diptera: Culicidae)

The mosquitocidal activity of different fractions and isolated compounds from the ethyl acetate extract of Ecbolium viride root was assessed on larvae and pupae of Culex quinquefasciatus Say (Diptera: Culicidae). The larvae and pupae were exposed to concentrations of 6.125, 12.5, 25 and 50 ppm for fractions and 1, 2.5, 5 and 10 ppm for compound. Among the 12 fractions screened, fraction 6 from the ethyl acetate extract of E. viride was recorded to have the highest larvicidal and pupicidal activities against C. quinquefasciatus. The lethal concentration (LC₅₀ and LC₉₀) values of fraction 6 were 4.26 and 9.0 ppm against C. quinquefasciatus larvae and 6.55 and 12.19 ppm against C. quinquefasciatus pupae, respectively, in 24 h. Fraction 7 was recorded to have moderate activity with LC₅₀ and LC₉₀ values of 11.25 and 25.02 ppm against C. quinquefasciatus larvae and 13.33 and 31.15 ppm against C. quinquefasciatus pupae, respectively, in 24 h. Ecbolin A and ecbolin B were identified from fractions 7 and 6, respectively. The structure of the isolated compounds was identified on the basis of spectral data (¹H NMR and ¹³C NMR) and compared with literature spectral data. Further, the isolated compound, ecbolin B, from fraction 6 was recorded to have strong larvicidal and pupicidal activities than ecbolin A. The LC₅₀ and LC₉₀ values of ecbolin B on C. quinquefasciatus larvae were 1.36 and 2.76 ppm, and on pupae, these were 1.54 and 3.51 ppm, respectively. The present results suggest that ecbolin B could be used as a mosquitocidal agent against C. quinquefasciatus.