Vital capacity and airflow measured from partial flow-volume curves during 5 degrees head-down tilt

Ten healthy young males were subjected to 7 min of 5 degrees head-down tilt, during which their forced vital capacity, peak flow rate (from complete flow-volume curves), and MEF 40% and 25% (airflows when 40% and 25% of the vital capacity remains in the lungs) from the partial curves were measured. The values of these variables and the heart rate and blood pressure were not significantly different from the values obtained in the supine position. In view of these findings it is concluded that the increase in the intra-thoracic blood volume, known to occur with 5 degrees head-down tilt used as a model for simulating weightlessness, does not embarrass respiratory mechanics.     

Blood nitrite levels in patients with migraine during headache-free period

OBJECTIVE: To investigate blood nitrite levels after migraine attacks and to assess whether or not the change in nitric oxide levels observed during acute migraine persist after the attacks. BACKGROUND: Involvement of nitric oxide has been suggested in the initiation of acute migraine. Recent studies have shown alteration in the platelet response and platelet nitrite levels during migraine attacks. METHODS: Patients with migraine with aura and patients without aura were included in the study. The study was conducted on 50 patients with migraine and 90 healthy controls. Blood from the patients was collected at least 7 +/- 0.8 days after the last attack of migraine. Nitrite levels in the polymorphonuclear leukocytes, platelets, and plasma were estimated. Platelet aggregation response in some of these patients was also studied. RESULTS: No significant change in the polymorphonuclear leukocyte, platelet, and plasma nitrite levels in patients with migraine compared to controls was observed. Patients with migraine with aura had significantly lower polymorphonuclear leukocyte nitrite levels compared to those without aura (P<.05). In addition, no significant difference in the adenosine diphosphate-induced platelet aggregation was observed in the migraineurs compared to the healthy controls. CONCLUSIONS: Results obtained indicate that the platelet aggregation response and the blood nitrite levels were not altered significantly after an attack in the patients with migraine.     

Neutrophil-free radical generation and enzymatic antioxidants in migraine patients

The present study was undertaken to elucidate the role of circulating neutrophils if any in oxidative stress in migraine by evaluating free radical generation and activities of enzymatic antioxidants in the blood in 55 patients with migraine and 60 healthy controls. Free radical generation was assessed by flow cytometry, while activity of catalase, superoxide dismutase (SOD) and glutathione peroxidase (GPx) was estimated in blood polymorphonuclear neutrophils (PMNs) by standard procedures. Platelet SOD was also measured. No significant change was found in free radical generation and in the activity of catalase, SOD and GPx in migraine patients. Univariate analysis of PMN catalase level revealed that migraineurs with a positive family history had significantly lower catalase activity compared with those with a negative family history. No correlation was found in the activity of antioxidant enzymes with age, duration of disease, time since last attack and headache index. The platelet SOD also did not show any significant change in patients of migraine without aura. Platelet aggregation in the presence or absence of PMNs was also not altered significantly. Thus the findings of the present study suggest that neutrophils are not the cause of oxidative stress observed in migraine patients.     

Platelet 3H ketanserin binding in migraine

Platelet 3H ketanserin binding was studied in 33 patients of migraine and 30 healthy controls. The binding characteristics: equilibrium dissociation constant (Kd) and maximal number of binding sites (Bmax) determined by Scatchard analysis revealed a significant decrease in Kd and no change in Bmax in migraine cases. No correlation was observed between the Kd and Bmax with the clinical features of migraine. The findings of the present study show that there is a decreased affinity of platelet 5-HT2 receptors in migraine.     

Hepatoprotective effect of stem of Musa sapientum Linn in rats intoxicated with carbon tetrachloride

Methods. The study was designed to evaluate the hepatoprotective activity of aqueous extract of central stem of Musa sapientum (AqMS) against carbon tetrachloride induced hepatotoxicity in rats. Animals were divided into six groups. Group I served as normal control. Group II, III, IV, V &; VI were administered CCl₄ mixed with olive oil 1:1 (1.5 mL/kg) I.P., twice a week for 5 weeks. Group II was maintained as CCl₄ intoxicated control. Group III, IV and V received AqMS at a dose of 25, 50 and 100 mg/kg. Group VI received silymarin 100 mg/kg for 5 weeks orally once daily. Marker enzymes of hepatic functions estimated in serum were AST, ALT and ALP. Antioxidant parameters estimated were MDA and GSH in blood and liver and SOD in blood, after fifth week, animals were sacrificed, livers dissected out and evaluated for histomorphological changes.Results. There was significant rise in AST, ALT and ALP in CCl₄ intoxicated control group II. Treatment with AqMS prevented rise in levels of these enzymes. There was significant rise in MDA and fall in GSH in blood and liver in group II, indicating increased lipid peroxidation and oxidative stress upon CCl₄ ad-ministration. Treatment with AqMS prevented rise in MDA &; increased GSH in treated group. SOD levels were decreased in group II while groups treated with AqMS showed significant rise (p < 0.05). Maximum hepatoprotective effect was observed with 50 mg/kg dose. Hepatoprotective effect observed with this dose was comparable to standard hepatoprotective drug silymarin. The results of pathological study also support the results of biochemical findings.Conclusion. the results of the present study indicate that stem of Musa sapientum possess hepatoprotective effect and probably it is due to it’s antioxidant property.     

Anti-platelet effects of Curcuma oil in experimental models of myocardial ischemia-reperfusion and thrombosis

Extensive research on the mechanism of action and medicinal importance of curcumin obtained from turmeric (Curcuma longa) has unfolded its potential therapeutic value against many chronic ailments. Curcuma oil (C.oil), the highly lipophilic component from Curcuma longa has been documented for its neuroprotective efficacy against rat cerebral ischemia-reperfusion injury; however its effect on myocardial reperfusion injury remains unexplored. In the present study, effect of C.oil (500 mg/kg, po) was evaluated against myocardial ischemia-reperfusion induced injury in the rat model. C.oil failed to confer protection against cardiac injury, however significant reversal of ADP induced platelet aggregation (p < 0.05) was evident in the same animals. Moreover, collagen and thrombin induced platelet aggregation (p < 0.001) as well as tyrosine phosphorylation of various proteins in activated platelets was also suppressed. C.oil also offered significant protection against collagen-epinephrine induced thromboembolism in mice as well as augmented total time to occlusion against FeCl₃ induced arterial thrombosis in rats. C.oil however had no effect on coagulation parameters (TT, PT and aPTT) and exerted a mild effect on the bleeding time. Bioavailability of C.oil, as assessed by monitoring ar-turmerone, α,β-turmerone and curlone, was 13%, 11% and 7% respectively, indicating high systemic exposure. Moreover, longer mean residence time (MRT) of ar-turmerone (13.2 h), α,β-turmerone (11.6 h) and Curlone (14.0 h) and plasma elimination half lives in the range of 5.5 to 7.2 h correlated with single 500 mg/kg dose regimen of C.oil. In the present study, C.oil thus seems to be an efficacious and safe anti-platelet agent which was protective against intravascular thrombosis.