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A K Pandey

Publications and source records attributed to A K Pandey.

At least 19 recordsLinked to original sources
PubMed2001

Microbial metabolites as eco-friendly agrochemicals for the next millennium.

As a result of the increasing environmental and health-related problems caused by the synthetic agrochemicals currently used, suitable and non-hazardous innovative alternatives are being sought. Antagonism and allelopathy, both in nature and in agro-ecosystems, have attracted these researchers' attention, with the main goal of using these phenomena in the biological control of weeds. This article presents a review on the use and efficacy of microbial secondary metabolites which have potential as natural herbicides, either directly or as templates for bio-rational eco-friendly agrochemicals (allelochemicals). Their merits as alternatives to synthetic chemicals and biological control agents have been highlighted for an holistic approach in integrated pest/weed management.

Actinomycetales↗
PubMed2000

Stability constants of metal-humic acid complexes and its role in environmental detoxification.

Humic acid with hydroxyl-, phenoxyl-, and carboxyl-reactive groups can form coordination compounds with metals. The ion-exchange equilibrium method using Dowex AG 50W-X8, 20-25 mesh Na(+) form was used to determine stability constants of complexes formed between humic acid (isolated from the soil) 50-250 microg ( approximately 3x10(-5)-15x10(-5) mol/liter) and metal salts solution 200 microg at pH 3.5. The stability constant (log K) for different metal-humic acid complexes indicated the following order of the stabilities of complexes formed between humic acid and metal ions: Cu>Fe>Pb>Ni>Co>Ca>Cd>Zn>Mn>Mg. The data on stability constants demonstrated substantial deviation from Irwing-Williams series reported for divalent ions. The molar humic acid/metal ratios were also calculated. Some of the factors affecting the stability constants such as cation exchange capacity of humus soil, molecular radius, and molecular surface area of humic molecules were also estimated. The significance of the data to predict the behavior of these complexes in the environment is discussed.

Algorithms↗
PubMed2000

Individual kidney glomerular filtration rate in the interpretation of non-diagnostic curves on captopril renography.

Captopril renography is known to have low sensitivity in the detection of renovascular disease in patients with bilateral renovascular disease and in patients with unilateral renovascular disease with a small kidney. In these groups of patients, we have tried to make the standard captopril renogram more objective by simultaneously estimating the individual kidney glomerular filtration rate (IKGFR). Twenty-five patients (10 bilateral, 15 unilateral) with angiographically proven renal artery stenosis (RAS) were studied. Ten renal units in five hypertensive patients with normal renal arteries were used as controls. A fall of more than 10% in IKGFR post-captopril was considered a positive result. The sensitivities of renogram and IKGFR in patients with bilateral RAS were 52.9% and 88.2% respectively. In patients with unilateral RAS, the sensitivities of renogram and IKGFR were 30% and 80% respectively. A significant fall in IKGFR was noted in eight of the 15 'normal' renal units of the unilateral RAS group. In conclusion, individual kidney GFR estimation in combination with captopril renography improved significantly the sensitivity in patients with symmetrical bilateral RAS and unilateral RAS with a small, poorly functioning kidney. A fall in GFR in the normal counterpart of a unilateral RAS kidney may be indicative of ongoing damage in the non-involved kidney.

Adolescent↗
PubMed1999

Decay of the GRB 990123 optical afterglow: implications for the fireball model

Broad-band (ultraviolet to near-infrared) observations of the intense gamma ray burst GRB 990123 started approximately 8.5 hours after the event and continued until 18 February 1999. When combined with other data, in particular from the Robotic Telescope and Transient Source Experiment (ROTSE) and the Hubble Space Telescope (HST), evidence emerges for a smoothly declining light curve, suggesting some color dependence that could be related to a cooling break passing the ultraviolet-optical band at about 1 day after the high-energy event. The steeper decline rate seen after 1.5 to 2 days may be evidence for a collimated jet pointing toward the observer.

Journal Article↗
PubMed1999

In vitro susceptibility of opportunistic Fusarium spp. to essential oils.

The inhibitory effects of essential oils extracted from 10 Indian plants were evaluated against five fungi. The plants used for extraction of essential oils were six species of the genus Eucalyptus and Ocimum basilicum, Prosopis cineraria and Derris indica. The fungi used in the experiments were Fusarium solani, F. oxysporum, F. pallidoroseum, F. acuminatum and F. chlamydosporum. The susceptibility of the Fusarium species was tested by the paper disc method and the serial dilution technique. The results were compared with the inhibitory effects of miconazole on the fungi. The essential oils extracted from the Eucalyptus species markedly inhibited fungal growth. Prosopis cineraria did not show inhibiting properties. Among the fungi, F. oxysporum proved to be the most resistant species.

Antifungal Agents↗
PubMed1998

Leprosy vaccine: influence of dissolved oxygen levels on growth of a candidate strain (Mycobacterium w), and storage stability of the vaccine.

The growth of Mycobacterium w, a candidate strain for leprosy vaccine in submerged culture, was inhibited by the presence of over 40% oxygen saturation in the medium. Intracellular levels of superoxide dismutase and catalase were very low in the beginning. However, under controlled oxygenation, these levels increased with time. The augmentations of these antioxidant enzymes were associated with the elevated oxygen consumption by the culture. By maintaining the oxygen level below 20% during 6-day culture, it was possible to grow Mycobacterium w in five production batches up to a cell density of 3.7 +/- 0.70 x 10(9) bacilli ml-1. The shelf life of the vaccine produced in different batches was more than 2 years, both at 4 degrees C and at 26 degrees C. This provides a cost-effective, unit culture technology for the production of this candidate leprosy vaccine from a nonpathogenic organism, which will facilitate the widespread use of the vaccine.

Bacterial Vaccines↗
PubMed1998

Do the diminishing efficacy and increasing toxicity of sodium stibogluconate in the treatment of visceral leishmaniasis in Bihar, India, justify its continued use as a first-line drug? An observational study of 80 cases.

Eighty parasitologically confirmed cases of visceral leishmaniasis (kala-azar) in Bihar, India, were treated daily with 20 mg sodium stibogluconate/kg for 30 days, to assess the current efficacy and toxicity of this 30-day regimen. Clinical and parasitological cure was obtained in 48 (60%) of the patients. However, 26 (33%) patients did not respond to the first course of treatment (primary unresponsiveness), two relapsed after initial clinical and parasitological cure, and two were withdrawn from the study (one on day 6 of treatment because of cardiotoxicity in the form of supraventricular tachycardia and the other on day 24 because of severe loss of appetite). All 30 patients who were not entirely cured with sodium stibogluconate were successfully treated with amphotericin B. Electrocardiographic changes occurred in many of the patients as the result of treatment with sodium stibogluconate. Diminution in the height of the T wave was seen in 32 (40%), inversion of the T wave (Minnesota code 5-1, 5-2) in seven (9%), elevation of the ST segment (Minnesota code 4-1) in three (4%), prolonged QT interval (compared with baseline findings) in six (8%), and diminution in the height of the P, R and T waves in two (3%). Cardiac arrhythmia occurred in five patients (6%), supraventricular arrhythmia (coarse atrial fibrillation) occurred in one patient and ventricular tachycardia, ventricular fibrillation, torsade de pointes and multifocal ventricular ectopics occurred in the four patients (5%) who died of cardiotoxicity. Minor side-effects, such as pain at the site of injection (two cases), mild diminution in appetite (12 cases), metallic taste in mouth (six cases), and joint pain (two cases), were also observed. It was concluded that the efficacy of sodium stibogluconate in the study area has declined over the years and that its toxicity has increased. A more efficacious, safer and cheaper, alternative drug is required as the first line of treatment of kala-azar.

Adolescent↗
PubMed1996

Comparison of regimens of amphotericin B deoxycholate in kala-azar.

A total of 288 parasitologically proved patients of kala-azar were randomly allocated to three treatment groups. Patients in groups A, B and C received amphotericin B (AMB) in a dose of 1 mg/kg body weight (bw)/day, 0.75 mg/kg bw/day and 0.5 mg/kg bw/day for 20 days respectively. Apparent cure (afebrile at the end of therapy) occurred in all patients and parasitological cure in 96 (100%), 92 (96%) and 84 (88%) patients respectively in groups A, B and C. Ultimate cure (no relapse in six months of follow up) occurred in 95 (99%), 87 (91%) and 79 (82%) patients in groups A, B and C respectively. The difference between the ultimate cure in the three groups was significant (P < 0.05). The incidence of adverse events (rise in serum creatinine and fall in serum potassium, loss of appetite and shivering, rigor and fever during infusion indicative of renal, GIT and infusion related toxicities respectively) was similar in the three groups. This study showed that amphotericin B should be given at a dosage of 1 mg/kg bw/day for 20 days for Indian kala-azar patients to minimise relapses and prevent development of drug unresponsiveness.

Adolescent↗
PubMed1994

Daily versus alternate-day regimen of amphotericin B in the treatment of kala-azar: a randomized comparison.

Using a randomized study, we compared a daily and an alternate-day regimen of amphotericin B for the treatment of kala-azar, with respect to efficacy, adverse reactions, cost-effectiveness, and tolerance. The study subjects were 80 kala-azar patients, drawn from the first four decades of life and matched by age, sex, and parasite load. The patients were randomly allocated to treatment groups A and B (40 patients per group). Patients in group A received a daily regimen of amphotericin B, starting with an escalating dose of 0.05 mg/kg body weight per day until a daily dose of 1 mg/kg was reached; the latter dose was then given daily till a total dose of 20 mg/kg body weight had been administered. The patients in group B also started with an escalating dose of 0.05 mg/kg but when 1 mg/kg was reached the drug was given on alternate days. All 80 patients using the two treatment regimens were cured, no patient relapsed in either group in 6 months of follow-up, and their bone-marrow aspirates were free of amastigotes. Treatment of kala-azar patients with the daily regimen of amphotericin B at a dose 1 mg/kg body weight was as effective, not more toxic, equally well tolerated, and much more cost-effective than the alternate-day regimen and should be adopted for treatment of this condition.

Adolescent↗
PubMed1993

Evaluation of amphotericin B as a first line drug in comparison to sodium stibogluconate in the treatment of fresh cases of kala-azar.

A total of 150 patients of kala-azar matched for age and sex and parasitologically proved were randomly allocated to two equal treatment groups. Patients in one group received amphotericin B(AMB) in a dose of 1 mg/kg body weight (BW) on alternate days starting with 0.05 mg/kg/bw on first day with daily increments, till a total dose of 20 mg/kg/bw was given; the patients in the second group received sodium stibogluconate (SAG) in the dose of 20 mg/kg/bw, im daily for 30 days. The efficacy, safety and cost-effectiveness of the two drugs were compared. Apparent cure (afebrile at the end of therapy) in 75 (100%) and 69 (92%) patients and ultimate cure (no relapse in six months of follow up) in 75 (100%) and 60 (80%) patients occurred in the AMB and SAG groups respectively. The difference between the ultimate cure in the two groups was significant (P < 0.001). Six (8%) and 9(12%) patients of SAG group showed primary (with no response to SAG during treatment) and secondary unresponsiveness (with no response to SAG after relapse) respectively and they were cured with amphotericin B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Endocrinology of calcium metabolism in amphibians, with emphasis on the evolution of hypercalcemic regulation in tetrapods.

Amphibians are the most diverse group as regards the endocrinology of Ca homeostasis because in them only "true" parathyroid glands made first appearance but its involvement varies greatly according to their phyletic affinities and habitats. Presence of ultimobranchial gland, parathyroid and renal 25-hydroxyvitamin-D-1-hydroxylase enzyme in anurans represents their tetrapod pattern of Ca regulation. Among "higher" urodeles, both parathyroid and pituitary are involved in hypercalcemic regulation whereas in "lower" urodeles (some of them are "aparathyroid" too), pituitary alone appears to discharge this function. The latter situation is analogous to the fish. Apodans do possess ultimobranchial and parathyroid glands but the problem of their Ca metabolism has not yet been explored. This review deals exhaustively with the endocrinology of Ca metabolism in amphibians. Also, the evolution of hypercalcemic regulation in tetrapods will be discussed in the light of recent developments.

25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
PubMed1992

Dose-dependent vitamin D3, 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3-induced hypercalcemia and hyperphosphatemia, and the correlative changes in the activity of ultimobranchial and parathyroid glands of the toad, Bufo andersoni Boulenger.

Vitamin D3, 25(OH) vitamin D3 and 1,25 (OH)2D3 were administered daily to unfed male Bufo andersoni for 15 days which resulted in a significant hypercalcemia and hyperphosphatemia in a dose-dependent fashion. 1,25(OH)2D3 is more potent than the other metabolites. The treatment activated ultimobranchial gland but induced degenerative changes in parathyroid of the toads.

Animals↗
PubMed1991

Further experiences of Küntscher's nailing for tibial shaft fractures.

We present the experience of managing 429 fractures of the tibia fixed with straight Küntscher rods. The overall impression is quite encouraging because this method involves a short and easy operation with limited exposure and provides sound fixation. Complications have been negligible.

Adolescent↗
PubMed1991

Results of partial patellectomy.

We present an assessment of 200 patellar fractures treated mostly (175) by partial patellectomy. In 23 cases in which the quadriceps mechanism was 75% intact (MRC power approximately 4), the fractures were treated conservatively, with an overall acceptable result. The operative series with an average follow-up of 3 years has shown 80.3% excellent to good results. A classification of fractures of the patella, based on the anatomical fracture line and quadriceps functional loss as recorded in 690 case histories, is suggested.

Adult↗
PubMed1991

Comparison of regimes of treatment of antimony-resistant kala-azar patients: a randomized study.

Three hundred twelve patients with antimony-resistant kala-azar were randomized into three groups. The first group (A) received pentamidine isethionate intravenously three times each week until parasitological cure was achieved. Group B received pentamidine concomitantly with a 20-day regimen of sodium stibogluconate. Group C received pentamidine injections that were followed by 20 days of sodium stibogluconate therapy. All patients became afebrile after 10 injections of pentamidine. Parasitologic cure was achieved in approximately 98% of the patients who had 33 or more injections of this drug. The addition of the antimony compound did not appear to enhance the rate of parasitologic cure. Three patients continued to have parasites after 40 injections of pentamidine. After six months, the rate of parasitologic cure was significantly higher in Group C (pentamidine followed by sodium stibogluconate) than in either Group A or B. Forty patients relapsed after apparent parasitologic cure and were successfully treated with five additional injections of pentamidine, followed by a course of antimony therapy. Minor side effects with pentamidine included an uneasy feeling during intravenous injection (12%), intestinal disturbances (6%), cellulitis (5%), abscess formation (1%), and allergic manifestations (2%). Major reactions to this drug included hyperglycemia (10%; reversible in 6% and irreversible in 4%), and delayed hypoglycemia (8%). Four deaths were associated with the administration of this compound. It is concluded that pentamidine is an effective but toxic drug for the treatment of antimony-resistant kala-azar.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗