Co-pyrolysis of phumdi and para grass biomass from Loktak Lake

In the present work, the pyrolysis of para grass (PG) and phumdi (PH) biomass samples was conducted in the temperature range of 300-500 °C to obtain the optimum temperature for obtaining the maximum yield of bio-oil. Further, co-pyrolysis experiments of PH and PG were also conducted at the same optimized temperature and varied compositions to investigate the synergistic effect. It was observed during the co-pyrolysis, that the maximum bio-oil yield of 37.80 wt% was obtained at the mass ratio of 1:1. The GC-MS, FT-IR and ¹H NMR analysis revealed that the bio-oils produced from all the processes were rich in functionalities. Phenolic compounds such as 2-methoxy-4-vinyl phenol, phenol, 2-methoxy, phenol 4-ethyl constituted a significant portion of bio-oils. The biochars obtained at the optimum pyrolytic conditions were analyzed by FT-IR and TOC analyzer.

Nitric oxide status in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) are at an increased risk of cardiovascular (CVD) morbidity and mortality, mainly due to atherosclerosis. Decreased production or reduced bioavailability of nitric oxide (NO) can result in endothelial dysfunction (ED). Multiple mechanisms are known to cause a state of NO deficiency in patients with CKD. Patients in various stages of CKD grouped as group-1 (CKD stage 1 and 2), group-2 (CKD stage 3 and 4), group-3 (CKD stage 5) and healthy controls were included in the study. Each group of patients and controls comprised 25 subjects. Plasma nitrites, L-arginine, asymmetric dimethyl arginine (ADMA) and citrulline were measured in all the subjects. Patients in all stages of CKD had lower NO and higher ADMA levels compared to controls. Further, group-2 and group-3 patients had lower levels of NO and higher levels of ADMA than group-1 patients. L-arginine levels showed no difference between patients and controls. However, group-3 patients had lower L-arginine levels compared to group-1 patients. Citrulline levels were decreased in group-3 patients. NO production was decreased in patients in all stages of CKD. The decrease could be due to decreased availability of the substrate, L-arginine or due to an increased ADMA, a potent inhibitor of endothelial NO synthase. Therapeutic interventions directed towards improvement of NO production in addition to management of other CVD risk factors may prevent development of ED and facilitate proper management of CKD patients who are at increased risk for CVD.

Antinociceptive activity of Malvastrum coromandelinum

The aerial parts of Malvastrum coromandelinum showed antinociceptive activity in the 0.6% acetic acid-induced writhing test in mice, the effects of acetone extract (200 mg/kg, p.o.) being comparable with acetylsalicylic acid (100 mg/kg, p.o.)

Depression in patients with HIV infection

The epidemiology, clinical features, and drug treatment of depression in HIV-infected patients are discussed. The lifetime prevalence of depression in patients infected with HIV has been estimated at 22-45%. The signs and symptoms of depression are similar in HIV-infected and noninfected patients, but patients with HIV infection may more frequently have sleep and appetite disturbances. Diagnosis should focus on affective or cognitive depression symptoms that reflect mood state alone. Patients with a history of depression, homosexual men, women, and i.v. drug abusers are among HIV-infected individuals who may be at increased risk for depression. Depression may alter the course of HIV infection by impairing immune function or influencing behavior. Depression my contribute to nonadherence to therapy. Antidepressant therapy is effective in most HIV-positive patients with major depression. Tricyclic antidepressants (TCAs) have produced response rates as high as 89%, but their usefulness has been limited by adverse effects. Selective serotonin-reuptake inhibitors and other non-TCAs have also demonstrated efficacy and are generally better tolerated. Psychostimulants have improved mood, cognition, and energy level, and androgens have been used for their anabolic effects. The systemic concentrations of antidepressants may be altered by coadministered drugs that affect their cytochrome P-450 isoenzyme-mediated metabolism; in turn, the metabolism and toxicity of certain antiretrovirals may be affected by antidepressants. Guidelines on the treatment of depression in the general population may be applied to patients with HIV infection. Depressive disorders are prevalent among patients with HIV infection but often respond to a variety of treatments.

Antinociceptive and anti-inflammatory activity of Sida rhomboidea leaves

Various organic extracts of Sida rhomboidea leaves were studied for antinociceptive and anti-inflammatory activity at a dose of 200 mg/kg. Ethyl acetate extract has shown significant (P < 0.01) antinociceptive activity. Percentage inhibition of edema by butanolic extract (33.05, P < 0.001) is comparable to that of phenylbutazone, 100 mg/kg inhibition (38.83%). Phytochemical screening of the extracts indicated the presence of alkaloids, steroids and/or triterpenoids and their glycosides, tannins, flavonoids and their glycosides, carbohydrates and absence of cardiac glycosides.

Synthesis of 7-substituted-4-(3',4',5'-trisubstituted-1-pyrazolyl)pyramido-[5,4-c] cinnolines and their anti-inflammatory activities

Eight title compounds were synthesised from substituted anelines. All compounds were tested for inhibition of bovine serum albumin denaturation. Few selected compounds were studied for their ability to provide protection against carrageenin-induced edema in rat paw and to inhibit denaturation of bovine serum albumin in an attempt to elucidate their cellular mechanism of action. There was no relationship between anti-inflammatory activity of 7-substituted-4-(3',4',5'-trisubstituted-1-pyrazolyl)pyrimido[5,4- c] cinnolines and their bovine serum albumin denaturation effectiveness.

Myocardial contractile protein ATPase activities in adrenalectomized and thyroidectomized rats

This report compares the effects of adrenalectomy and thyroidectomy, with and without hormone replacement, on loss of contractile protein ATPase activities. The rationale for this study was derived from the similarities in their intracellular receptors, mechanisms of action, and the large number of proteins regulated by both hormones. Rats were adrenalectomized, thyroidectomized, or both, and were subsequently treated for 6 weeks with hydrocortisone, triiodothyronine, or saline. Sham-operated rats were given saline for the same period of time. Six weeks of adrenal insufficiency resulted in diminished enzymatic activity of myofibrillar, Ca(2+)-activated myosin ATPase, and actin-activated myosin ATPase fractions. Treatment with hydrocortisone prevented the decline in enzymatic activity due to adrenalectomy. Likewise, thyroidectomy caused a loss of enzymatic activity which was prevented by treatment with triiodothyronine. The full deleterious effect of combined ablation could be partially prevented by treatment with either hydrocortisone or triiodothyronine, but the latter was most effective. The results suggest that hydrocortisone and triiodothyronine each had significant positive effects in the presence of the other, but not in its absence, on the activity of myofibrillar Ca(2+)-dependent Mg-ATPase and Ca(2+)-activated myosin ATPase. The effects of these two hormones on actin-activated myosin ATPase activity were more independent of each other. We conclude that the actions of thyroid and glucocorticoid hormones on the heart are interrelated and that optimum myocardial function results from their combined action.

Myofibrillar and membrane-bound enzymes in skeletal muscle from myodystrophic mice

1. Experiments were carried out to examine the biochemical changes, such as contractile protein biochemistry and membrane bound enzyme alterations associated with skeletal muscles of myd/myd. 2. Our studies demonstrate that there was a progressive decline in myofibrillar ATPase activity, and this decrease is greatest in 30 weeks old animals of myd/myd as compared to controls. 3. The proteolytic activity of myofibrils isolated from myd/myd was significantly higher than controls. 4. There was no significant difference in Ca2+ ATPase activity of myosin and actin-activated myosin ATPase activity of myd/myd and their controls. 5. Mg2+ ATPase and Na(+)+K(+)-ATPase of myodystrophic SL showed significant increase compared to controls. 6. Isoproterenol stimulated adenylate cyclase activity was significantly lower in the SL of dystrophic mice compared to controls. 7. GTP+isoproterenol stimulate adenylate cyclase was significantly higher in control SL and SR when compared to SL and SR isolated from myd/myd. 8. Guanylate cyclase activity was greater in myodystrophic mice both in the absence and presence of Triton X-100. cGMP and cAMP phosphodiesterase activities were greater in dystrophic mice as compared to controls. 9. These observations suggest that there are significant changes in myofibrillar ATPase, myofibrillar protease and membrane bound enzymes of myd/myd compared to control.

Effects of acute and chronic ethanol on cardiac contractile protein ATPase activity of Syrian hamsters

Ethanol consumption is known to affect cardiac and skeletal muscle. In vivo experiments on cardiac muscle showed that ethanol affects cardiac contractility and Vmax, suggesting that contractile proteins of the myocardium were affected by ethanol. Therefore, experiments were carried out to examine the effects of ethanol on the cardiac contractile protein ATPase activities. Cardiac myofibrils isolated from ethanol-fed hamsters showed a significant decrease in myofibrillar ATPase activities between pCa 6 and 4. On the other hand, addition of ethanol (0.1%) in vitro to cardiac myofibrils from control hamster had no significant effect on the ATPase activities, suggesting that hamsters need to be exposed for longer periods of time to induce demonstratable changes in the contractile protein ATPase activity. Actin-activated myosin ATPase activities were significantly lower in myofibrils from ethanol-fed hamsters at 1:1 and 1:2 ratios of myosin to actin. These investigations revealed that chronic (4 weeks) exposure of hamsters to ethanol reduced cardiac contractile protein ATPase activity, which may help explain impaired cardiac function in chronic alcoholics.

Effects of riboflavin analogues and diuretics on the spontaneously hypertensive rat heart

The chronic treatment of spontaneously hypertensive rats (SHR) with 7,8-dimethyl-10-(3-chlorobenzyl) isoalloxazine [CBI], 7,8-diethyl-10-aminol isoalloxazine [DEAI], enduron (methyclothiazide) and amiloride were studied for their effects on blood pressure and cardiac contractile protein ATPase activities. After 35 weeks of treatment all the above antihypertensive agents showed a decrease in blood pressure in the SHR (p less than 0.01). Chronic treatment with CBI, DEAI, enduron, and amiloride significantly improved the myofibrillar ATPase activity at all pCa2+ concentrations (p less than 0.01). Furthermore, CBI, DEAI, enduron, and amiloride drug treatments enhanced actin-activated myosin ATPase activity (p less than 0.01). The Ca2(+)-activated myosin ATPase activity was significantly elevated after treating with CBI and DEAI (p less than 0.01). These results suggest that the antihypertensive agents used in this study helped in reducing the blood pressure with a subsequent increase in myocardial contractile protein ATPase activity.

Changes in myocardial contractile protein ATPases in chronically adrenalectomized rats with and without glucocorticoid replacement

Studies were conducted to examine the effects of chronic adrenalectomy (Adx) and adrenalectomy plus glucocorticoid replacement therapy on rat cardiac contractile protein ATPase activities. The Ca2+-dependent Mg-ATPase activity of myofibrils isolated from rat ventricles 3 weeks postadrenalectomy (Adx) was significantly decreased at all pCa2+ concentrations (P less than 0.01), compared to sham-operated (SO) rats. Similarly, Ca2+-, K+-EDTA, and actin-activated myosin ATPase activities of Adx rat hearts were markedly decreased below that of SO rats (P less than 0.01). Dexamethasone administration to Adx rats prevented the decrease of Ca2+- and K+-ATPase activities of myosin, but not of myofibrillar Ca2+-dependent Mg-ATPase or actin-activated myosin Mg-ATPase activities. These studies suggest that glucocorticoid insufficiency induced by adrenalectomy results in altered myocardial contractile protein ATPase activity which may underlie impaired cardiac performance.

Cardiovascular changes in chronically adrenalectomized conscious rats

Mean arterial blood pressure (MABP), heart rate (HR), stroke volume index (SVI), cardiac index (CI), systemic vascular resistance index (SVRI), and central venous pressure (CVP) were measured in conscious, freely moving, sham-operated (SO) and chronically adrenalectomized (ADX) rats. After 3 weeks of ADX, the rats exhibited hypotension, tachycardia, and diminished SVI and CI. From 3 to 6 weeks after surgery, the HR decreased and SVRI increased. These changes were obscured when the same measurements were obtained in the same rats under enflurane anesthesia. Cardiovascular responses to an epinephrine (0.4 microgram/kg/min) infusion were measured in conscious SO and ADX rats. The magnitude of change from baseline to peak was similar in all groups, indicating that ADX did not alter the responsiveness of the cardiovascular system to epinephrine. The peak MABP response to epinephrine in ADX rats was significantly below that of SO control rats, suggesting that ADX impaired the ability of the cardiovascular system to maintain normal arterial blood pressure. No differences were found in plasma concentrations of Na+, K+, Cl-, PO4 =, or hematocrit that would help to explain the effect of long-term adrenalectomy. The data underscore the cardio-depressant effect of enflurane anesthesia, demonstrate the importance of a conscious rat model in studying the effects of ADX on the cardiovascular system, and emphasize that the full effects of ADX occur over a period of several weeks.

Effects of organophosphorus agents on sarcoplasmic reticulum in skinned skeletal muscle fibers

These experiments were designed to determine whether skinned skeletal muscle fibers could be useful in screening new antidotes to organophosphorus poisons. Isometric force and fiber diameter were measured in mechanically skinned fibers from mice and frogs. Fibers were depleted of calcium and placed in a calcium loading solution that contained 0.5 mM EGTA with pCa 6.25. The elapsed time (zero time) before a contracture began and the maximum rate of force development (slope) were measured and divided by the square of the diameter (normalized zero time, normalized slope). The zero time was assumed to be the time required for the sarcoplasmic reticulum to attain a threshold concentration for calcium-induced calcium release, and the slope was assumed to indicate primarily the rapidity of the release of calcium from the sarcoplasmic reticulum. Organophosphorus agents, sarin, soman, tabun, and VX were also placed in the loading solutions. Only sarin failed to shorten the normalized zero times of mouse fibers compared to controls, and all agents decreased the normalized slopes. The normalized zero times of frog fibers were not altered by the agents, but the normalized slopes were altered by some agents. Pralidoxime chloride (PAM) and 3-Cl-2,5,6-trimethylbenzoic acid (TBA) were also added to the loading solution for mouse fibers; PAM was marginally effective in moderating some actions of the organophosphates. Because the effects of the agents on the fibers were so definite, we concluded that the skinned muscle fiber might indeed be useful as a screening tool for developing and testing new antidotes to organophosphorus poisons.

Control of myofibrillar ATPase activity and force in myodystrophic muscle

Myofibrillar ATPase activity was measured as a function of the free calcium concentration in skeletal muscles of control and myodystrophic mice. In addition, the force developed in skinned extensor digitorum longus (EDL) fibers of control and myodystrophic mice was measured as a function of the free calcium concentration, and a histomorphometric study was performed on soleus and EDL muscles of control and myodystrophic mice. The results showed that the myofibrillar ATPase activity and the force-generating mechanisms of control and myodystrophic muscles were controlled to the same relative degree by equivalent concentrations of calcium ions. Upon maximal activation of the ATPase activities, we measured 18% less activity in myodystrophic muscles than in control muscles. Maximal activation of the force-generating capacity in skinned fibers showed there was no significant difference in force produced in the control compared to myodystrophic fibers. The histomorphometric study revealed no alteration in the relative distribution of different fiber types in myodystrophic compared to control muscles. However, the histomorphometry did reveal a larger slow (type 1) relative cellular area compared to total cross-sectional area in myodystrophic muscle than in controls. We propose that the lower ATPase activity but equal force-generating capacity of myodystrophic muscles compared to control muscles is due to myodystrophic muscles being composed of a greater fraction of myofibrils from slow (type 1) fibers than control muscles.

Phosphorylation of cardiac regulatory proteins by cyclic AMP-dependent protein kinase

Cardiac myofibrils were purified from canine myocardium, and the regulatory proteins (troponin + tropomyosin) were extracted and shown to contain endogenous cyclic AMP-dependent protein kinase activity. Other cyclic nucleotide stimulated the protein kinase activity but only at higher concentrations. The enzyme was able to catalyze phosphorylation of conventional substrates such as histones and casein as well as a component of the regulatory protein fraction with a molecular weight of 28,000 daltons. Endogenous phosphorylation required the presence of Mg2+ and was inhibited by Ca2+. A protein kinase inhibitor obtained from skeletal muscle inhibited the cyclicAMP-dependent phosphorylation. Escherichia coli alkaline phosphatase dephosphorylated the endogenous substrates. The level of phosphorylation found is severalfold higher than we have previously reported. A protein kinase, with its close association with the regulatory proteins, seems to be well suited to transmitting the message from the cyclic AMP to the regulatory proteins, a phenomenon that may influence the cardiac contractility via the troponin phosphorylation. The inhibitory effect of troponin on actomyosin might be changed by its state of phosphorylation.

Biochemical and morphological correlates of cardiac ischaemia: Contractile proteins

Experimentally-induced ischaemia in the dog heart was produced by ligating the left circumflex artery. Myosin B isolated from the ischaemic portion of the myocardium differed from myosin B isolated from control tissue in its diminished response to the calcium chelator ethyleneglycol bis (beta-amino-ethylether)-N, N'-tetraacetic acid (EGTA). In the presence of EGTA, ischaemic myosin B required 2.5 +/- 0.5 min for completion of superprecipitation, whereas control myosin B required 6.6 +/- 2.5 min. Likewise, the Mg++ -activated ATPase activity of ischaemic myosin B was inhibited by EGTA to a lesser degree than control myosin B. Experiments with reconstituted myosin B using desensitized control myosin B and regulatory proteins suggest that ischaemia induces changes in the regulatory proteins (troponin and tropomyosin).

Interaction of Ca++ binding sites of troponin: significance for Ca++ movements

Ca++ binding data for seven preparations of troponin and 37 preparations of native tropomyosin were analyzed by the method of nonlinear least squares. The analysis was based on the assumption that two classes of independent binding sites exist. Data from one-third the preparations could not be fitted with all binding parameters at true least-squares minimum, and computed values of parameters for two-thirds the preparations were biologically uniterpretable. We conclude that troponin does not contain two classes of independent binding sites. Comparison of Scratchard plots of Ca++ binding by troponin and native tropomyosin modifies binding through a cooperative effect on troponin. Certain features of the Scratchard plots are imcompatible with the possibility that troponin possess more than two classes of independent sites. We interpret these results to mean that troponin's binding sites interact and that the interaction is increased by tropomyosin. The interaction would cause Ca++ affinity to vary with time during a muscle contraction. The effect of variable Ca++ affinity on intracellular Ca++ movements and the time course of the active state is discussed.