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Biomedical subjects

N Agarwal

Publications and source records attributed to N Agarwal.

At least 163 records · Page 9Linked to original sources
PubMed1988

Systemic complications of acute pancreatitis.

The multisystem involvement in acute pancreatitis (AP) is a reflection of the pancreatic gland's capacity to produce a number of potent vasoactive peptides, hormones, and enzymes. The various prognostic criteria are early evaluations of these metabolic derangements. The pathogenesis of hypocalcemia, long recognized as an indicator of severity of AP, is multifactorial. Imbalances of parathyroid hormone (PTH)-calcitonin, the interactions of glucagon, gastrin and other pancreatic hormones with PTH-calcitonin, the role of free fatty acids in binding serum calcium with albumin, and the translocation of calcium ion in muscles and liver, have been recently described but remain conflicting theories. Yet, the time-honored theory of calcium-soap formation enjoys wide acceptance. Hyperglycemia, hypoglycemia, and occasional ketoacidosis in acute pancreatitis have been studied thoroughly. The complex cause-and-effect relationship between hyperlipidemia with acute pancreatitis needs further study. The coagulation abnormalities seem to be initiated by activated trypsin, and their role in microvascular coagulation appears to form a unifying hypothesis for major organ dysfunction, but this requires further investigation. Adult respiratory distress syndrome may be the result of active enzymes that digest pulmonary surfactant and/or microvascular thrombosis. The depression of cardiac function and shock are suspected to be secondary to vasoactive peptides such as bradykinin, or myocardial depressant factor, whose structure has yet to be elucidated. The renin-angiotensin alterations and renal complications in acute pancreatitis have received scant attention in the literature. The onset of moderate visual disturbances, or even blindness, in a patient with acute pancreatitis as a result of retinal vessel thrombosis is fortunately uncommon. Rare but interesting are the manifestations such as subcutaneous fat necrosis, arthralgia, and pancreatic encephalopathy. Despite the extensive literature on the complexities of the pathogenesis of complications of acute pancreatitis, there have been very few advances in the prevention and management of specific complications. It is hoped that further work on modification of enzymatic disturbances induced in acute pancreatitis will result in its effective treatment and prevention of serious complications.

Acute Disease↗
PubMed1987

Stimulation by serum of the Na+/H+ antiporter in quiescent pig kidney epithelial (LLC-PK1) cells and role of the antiporter in the reinitiation of DNA synthesis.

LLC-PK1 cells can be brought into a classical quiescent state by depriving them of serum for 6 days. At this time, pulse-labeling with [3H]-thymidine shows that only 3% of the cells are synthesizing DNA, but the quiescent cells can be stimulated with serum to re-enter the cell cycle at a point early in G1. The rate of amiloride-sensitive 22Na+ uptake (as a measure of the Na+/H+ antiporter) is relatively low during quiescence; it rises 2- to 3-fold within 4 h after serum addition. This increase in antiporter activity appears to be required for the resumption of DNA synthesis in the absence of bicarbonate, because ethylisopropylamiloride (EIPA) blocks [3H]-thymidine incorporation when serum is added to cells in bicarbonate-free medium. In the presence of bicarbonate, however, EIPA has no effect on [3H]-thymidine incorporation, indicating that another (bicarbonate-dependent) transport system can substitute for the antiporter under these conditions.

Amiloride↗
PubMed1987

Clinical evaluation of steroid receptors in ovarian neoplasms.

Estrogen and progesterone receptors were estimated in a total of 25 ovarian neoplasms. None of the benign tumors showed steroid receptors. In malignant tumors serous tumors were more often receptor positive than the mucinous. Receptor levels were correlated with the staging of the disease, menstrual status and the resectability of the tumor. The response to chemotherapeutic drugs was better in patients with low estrogen and progesterone receptors as compared to those with high levels. The latter group showed a definite response to progesterone treatment in vitro. These are the group of patients who may benefit by combination of hormones and chemotherapeutic drugs.

Cystadenoma↗
PubMed1987

Inhibition of aspartic proteinases by peptides containing lysine and ornithine side-chain analogues of statine.

The synthesis of two new analogues of statine are reported corresponding to analogues with the lysine side chain and the ornithine side chain. These analogues were designed on the basis of substrate specificity and molecular modeling of three-dimensional structures of the penicillopepsin: Iva-Val-Sta-OEt crystal structure. 4,8-Diamino-3-hydroxyoctanoic acid [LySta] and 4,7-diamino-3-hydroxyheptanoic acid [OrnSta] were synthesized respectively from Boc-Lys(Z)-al and Boc-Orn(Bzl,Z)-al by addition of lithio ethyl acetate to the aldehyde group. The [LySta] derivative was converted to the trichloroethoxycarbonyl derivative and separated into the corresponding 3S,4S and 3R,4R diastereomers. The [OrnSta] derivative was used as a mixture of 3-position diastereomers. These new amino acids were used to prepare the following inhibitors: Iva-Val-Val-[LySta]-OEt and Iva-Val-Val-[OrnSta]-OEt as well as the corresponding synthetic intermediates. Inhibition constants (Ki values) were measured for inhibition of porcine pepsin and penicillopepsin. Both compounds were potent inhibitors of penicillopepsin with Ki values 10-100 times smaller (2.1 and 1.1 nM, respectively) than the Ki of Iva-Val-Val-Sta-OEt (47 nM). In contrast both inhibitors are exceptionally weak inhibitors of porcine pepsin with Ki values greater than 1 microM. These results are correlated with the ability of the basic group in the new inhibitors to bind to aspartic acid-77 in penicillopepsin.

Amino Acids↗
PubMed1987

Ultrasound detection of antenatal meconium.

A new method for antenatal diagnosis of the presence of meconium in the amniotic cavity is reported. Ultrasonographic placental grading is a routine procedure in the monitoring of high-risk pregnancy. During serial scans of 58 patients, it was noted that in 11 cases placental grading was impossible after a certain period. At delivery, thick meconium was noted in all these cases.

Adult↗
PubMed1987

Synthesis and metabolic disposition of 14C-centperazine in rats.

The metabolic disposition of [2-14C]-centperazine (1; 3-ethyl-8-methyl-1,3,8-triazabicyclo[4.4.0]decan-2-one) following an injection of 5 mg/kg dose was studied in male albino rats. During the initial period of 45-60 min, a very rapid fall in blood level of radioactivity was noticed. Thereafter the rate of fall of blood radiocarbon went on decreasing but did not attain linearity even upto 24 h. The drug was found to be fairly distributed in all the tissues attaining highest concentration in most of them within 30 min. In 24 h, about 83.5% of the administered drug was eliminated from the body, of which 21.3% was recovered from the faeces and 61.1% from the urine. The 14CO2 accountes for only 1% of the total dose. The drug exhibited significant binding with all the tissues examined. The brain and muscle showed highest and lowest activity, respectively.

Animals↗