Biomedical subjects

N Agarwal

Publications and source records attributed to N Agarwal.

At least 127 records · Page 7Linked to original sources

PubMed1991

Limitations of the TRISS method for interhospital comparisons: a multihospital study.

The value of the TRISS method for interhospital comparisons of trauma care was studied using data for 5,616 consecutive patients from three trauma centers and five community hospitals. Z-scores were used to compare mortality rates. Three limitations of the method were documented: 1) the lack of homogeneity within the patient subcategory of penetrating injuries, specifically between patients with gunshot versus stab wounds; 2) the inability of the TRISS method to predict the survival rate of patients suffering low falls; and 3) the inability of the TRISS method to account for multiple severe injuries to a single body part. Remedies to the first two of these limitations can be addressed within the present TRISS method. A remedy for the third requires a new method.

Abbreviated Injury Scale↗

PubMed1991

Repair of a traumatic noncircumferential hepatic bile duct defect using a vein patch: case report.

Injury to the bile ducts secondary to blunt trauma is a rare but potentially fatal condition that presents a difficult diagnostic and treatment challenge. Various treatment options exist for repair. Vein patch repairs have been criticized because of reports of subsequent fibrosis and stricture formation. This case report describes the successful repair of a traumatic, noncircumferential defect of a hepatic bile duct with a vein patch, and stresses the importance of an adequate duration of stenting.

Adolescent↗

PubMed1991

Renal cyst formation and multifocal neoplasia in transgenic mice carrying the simian virus 40 early region.

Simian virus 40 early region transgenic mice develop characteristic pathological abnormalities of the brain, kidney, and thymus, due to expression of large-T antigen. Earlier studies have indicated that the most consistent effect of large-T antigen expression is the formation of choroid plexus papillomas in the brain and that thymic hyperplasia and various kidney abnormalities are less frequently observed. The renal lesions reportedly consist of numerous glomerular abnormalities and tubular proliferation. Surprisingly, an analysis of 21 simian virus 40 early region transgenic mice, which were produced for this study, revealed a much higher incidence of polycystic kidney disease as well as earlier development of T-antigen-induced abnormalities. In marked contrast to earlier observations, there is an apparent reduction in the glomerular number in the affected kidneys, whereas the remaining glomeruli appear normal. The most striking feature of the T-antigen-induced renal abnormalities was extensive hyperplasia of tubular epithelial cells which was most marked in the distal tubules; all tubule segments are involved in the most severely affected animals. In most cases, cysts lined with hyperplastic epithelium were observed and papillary structures protruding from the cyst lining were evident. Multiple areas of focal neoplasia were apparent, and, in the most severely affected animals, there were areas in which tumor had replaced normal renal parenchyma. These results strongly suggest that T-antigen-induced renal cyst and tumor formation are part of the same pathological process which is initially manifested as tubular epithelial hyperplasia.

Animals↗

PubMed1991

Dietary cholesterol induced changes in lipid profile in patients with nephrotic syndrome and chronic renal failure.

Fifteen patients with nephrotic syndrome (9 aged below 30 years), 6 patients with chronic renal failure and 26 healthy males (14 below 30 years) were studied. After estimating the basal serum levels of total cholesterol (STC), triglycerides (STG), high density lipoprotein (HDL) and low density lipoprotein (LDL), the patients were given a high cholesterol and high fat breakfast (containing 32 g fat and 527 mg cholesterol) for 7 days. Lipoprotein levels were again estimated on days 8 and 16. In the basal state, all patients with nephrotic syndrome had markedly elevated levels of STC and LDL. In patients aged below 30 years, STG and VLDL levels were also elevated, while HDL levels were similar in both the groups in comparison to their respective age group controls. In patients with renal failure, basal levels of all lipoproteins were similar to levels in controls. After the high cholesterol fat diet, there was an insignificant rise in all lipoprotein values in patients with nephrotic syndrome and renal failure. However, HDL levels rose significantly in patients with nephrotic syndrome aged below 30 years. Patients with nephrotic syndrome and chronic renal failure can safely be given high cholesterol and high fat diet despite abnormalities in lipid lipoprotein metabolism.

Adolescent↗

PubMed1991

High density lipoprotein.

High density lipoprotein (HDL) is a discoidal particle comprising phospholipid, cholesteryl esters and several apolipoproteins. It serves in transporting cholesterol from the periphery to the liver by the process of "reverse cholesterol transport". Compatible with this is the finding that the mass of the tissue cholesterol pools is inversely related to plasma HDL concentration. The plasma levels of components of HDL are determined by various physiological and pathological factors. The serum HDL levels are lower with advancing age, male sex, and in genetically predisposed, obese, sedentary persons. The effect of diet on serum HDL levels is not established; mild to moderate alcohol intake is associated with high serum HDL level. The main diseases affecting serum HDL levels are uncontrolled diabetes mellitus, uraemia and hyperthyroidism. Anabolic steroids, sex hormones, oral contraceptives, hypocholesterolaemics and beta blockers have been shown to affect serum HDL level variably. There is increasing epidemiological evidence to show that high levels of HDL are protective against coronary heart disease (CHD). A low serum HDL cholesterol concentration (less than 35 mg/dl) is associated with a significant increase in coronary risk in both men and women. Guidelines published by the National Cholesterol Education Programme do not recommend routine measurement of HDL cholesterol and adaptation of therapeutic modalities aiming to raise the low HDL levels. They recommend hygienic means (i.e. smoking cessation, aerobic exercises and weight loss) to raise the HDL cholesterol levels.

Female↗

PubMed1991

Assessment of severity in acute pancreatitis.

Assessment of severity of acute pancreatitis (AP) is a key determinant in the management of a patient. This review evaluates the various methods of assessment: clinical assessment, biochemical tests, Ranson's and Imrie's multiple prognostic criteria, simplified prognostic criteria, APACHE II, peritoneal lavage, and computed tomography. Although all of the above criteria can identify most of the seriously ill patients, each has some drawbacks. Individual preference and available institutional facilities greatly influence the method used for prognostic assessment in AP. However, some type of predictive assessment is possible in any hospital, and should be used in the management of patients with AP.

Acute Disease↗

PubMed1990

Opsin gene expression during early and late phases of retinal degeneration in rds mice.

Opsin mRNA levels, opsin synthetic rates and localization of opsin were studied throughout the photoreceptor's life span in the rds mice. Mutant mice 11 days to 11 months old were investigated. Opsin mRNA levels were studied by means of northern blot analysis. Opsin synthesis was measured by incorporation of [35S]methionine into newly synthesized opsin in vitro. Distribution of opsin in the retina was determined by immunoelectron microscopy. Opsin mRNA was detected in young as well as old retinas, and opsin synthesis could be detected at early phases of degeneration but not in late phases. The absence of opsin synthesis in older rds mice might be due to translational down-regulation or some other defect in the capacity to synthesize opsin. In young mice, opsin was detected in the subretinal space in opsin-laden vesicular membranes: such membranes were absent from retinas of older mice. This disappearance parallels the cessation of opsin synthesis and the consequent failure to deliver opsin to the subretinal space in retinas from older mice. Immunochemical analysis revealed the presence of small amounts of opsin in all retinas up to 11 months of age. Immunoelectron microscopy localized the residual opsin, mostly to the plasma membrane which envelops the nuclei and synaptic terminals. These opsin molecules might be a consequence of very low levels of opsin synthesis, too low to be detected by our assays, or may have been synthesized at an earlier age and retained in the plasma membrane of the old mutant photoreceptors.

Animals↗

PubMed1990

A study of dietary cholesterol induced changes in serum lipid lipoproteins in healthy male children, adolescents and middle aged volunteers.

The present study comprised of 16 healthy male subjects of 8-12 years (Group A), 18 adolescent males (13-19 years) (Group B) and 20 middle aged volunteers (45-55 years) (Group C), who were fed a high cholesterol high fat diet (HCFD) consecutively for seven days. The serum lipid changes were noted. The diet was then withdrawn. Seven days later the lipid changes were again recorded. At basal stage, serum total cholesterol (STC), high density lipoprotein (HDL) and low density lipoprotein (LDL) were significantly higher in group C in comparison to Group A. LDL/HDL ratio was significantly lower in Group C than that of Group A. Seven days after feeding of HCFD significant elevations occurred in all the lipid subfractions of Groups AB. The rise in STC was mainly because of predominant rise in HDL leading to a significant fall in LDL/HDL ratio. In Group C, elevations occurred in all the lipid fractions except HDL that showed an insignificant rise. LDL/HDL ratio was insignificantly affected. After withdrawal of HCFD, all the lipid levels returned to normal except in Group A, where STC and LDL remained elevated. The LDL/HDL ratio again increased significantly. In conclusion, the serum lipid lipoprotein behaviour in response to HCFD is qualitatively different in young persons as compared to middle aged persons.

Adolescent↗

PubMed1990

Frequency of HLA genes and islet cell antibodies (ICA) and result of postpartum oral glucose tolerance tests (OGTT) in Saudi Arabian women with abnormal OGTT during pregnancy.

A consecutive series of 55 Saudi women with abnormal 75 g oral glucose tolerance test (OGTT) during pregnancy was reinvestigated 2-4 months after delivery. A 75 g OGTT was done and samples were also drawn for analysis of C-peptide concentration, islet cells antibodies (ICA) and HLA antigens. The results of these laboratory investigations and a number of patient characteristics were analyzed to identify risk factors for patients likely to have impaired OGTT after delivery. Twenty-five (45.5%) of the patients had an abnormal OGTT after delivery. The distribution of HLA antigen frequencies did not differ from a reference group of healthy Saudis. ICA were found in only one patient. Logistic regression analysis identified insulin treatment during pregnancy (p = 0.001) as the only factor to predict an abnormal OGTT after delivery.

Adult↗

PubMed1990

Opsin synthesis and mRNA levels in dystrophic retinas devoid of outer segments in retinal degeneration slow (rds) mice.

Opsin gene regulation, as a function of outer segment structure, was studied in normal and mutant retinal degeneration slow (rds) mice. We investigated the level of expression of the opsin gene in the rds mutant to determine if the reduced opsin content observed in this mutation (around 3% of normal) is a consequence of lowered expression of its gene. Normal BALB/c and rds mice were analyzed for levels of opsin mRNA and opsin content by Northern and immunoblot analysis, respectively. The rate of opsin synthesis in isolated retinas was measured by 35S-methionine incorporation in vitro, followed by analysis of the radiolabeled opsin by SDS-gel electrophoresis and autoradiography. Photoreceptor cell loss at various stages of degeneration was determined by quantitation of surviving photoreceptor nuclei. Opsin was localized in the mutant photoreceptors by immunoelectron microscopy of LR gold-embedded retinas using anti-opsin and antibody gold conjugates. The results indicate that 11- and 30-d-old mutant mice have considerable levels of opsin mRNA (60-70% of normal) and opsin synthetic rates (76-92% of normal), after the data from mutant mice are corrected for photoreceptor cell loss. We conclude, therefore, that the very low level of opsin observed in rds mice (approximately 3%) is not a result of greatly reduced expression of the opsin gene. Rather, continuous turnover of newly synthesized opsin as a result of its failure to become sequestered into an intact outer segment appears to account for the low levels of opsin in the rds mutant.

Animals↗

PubMed1990

Evaluating tests for acute pancreatitis.

The relative merits of various serum pancreatic enzymes, ultrasonography (US), and computerized tomography (CT) have been evaluated. In practice, the diagnosis of acute pancreatitis (AP) remains hinged on the clinical picture and elevated serum amylase. The advantages of total serum amylase are its technical simplicity, ready availability, and sensitivity. Within 24 h of onset of symptoms, elevation of amylase is as sensitive as that of lipase, pancreatic isoamylase, immunoreactive trypsin, or elastase. However, after the first hospital day, it is the least sensitive of the enzymatic tests. Its greatest disadvantage is its overall low specificity. Lipase assays are now fast, reliable, practical, more specific, almost as sensitive, and not more expensive than amylase assays. The current feeling is that lipase assays should be used more often or even should replace amylase assays. However, comparative studies using objective criteria for AP are required to evaluate the utility of lipase estimations over that of amylase. Other enzymes such as P-isoamylase, immunoreactive trypsin, chymotrypsin, or elastase are more cumbersome, expensive, and not better than lipase. They should be reserved for cases of doubtful diagnoses. The levels of these pancreatic enzymes neither correlate with the severity of the disease nor can they accurately predict the subsequent clinical course of the patients. The main role of ultrasonography remains in the evaluation of the biliary tract in AP. The contrast-enhanced computed tomography (CECT) is useful for estimating the presence and extent of pancreatic necrosis. Thereby, it enables prompt recognition of patients at high risk for systemic and local complications. Routine use of CECT may aid in the identification of pancreatitis when enzyme elevations are modest, but the utility of the procedure in all clinically mild cases is questionable. Patients who are seriously ill or who present a diagnostic problem should have a CECT. A normal CT under such circumstances excludes clinically severe AP. Serial CT should be done in patients demonstrating phlegmonous extrapancreatic spread.

Acute Disease↗

PubMed1990

Oral versus axillary temperatures in human volunteers.

We measured the oral and axillary temperatures of 100 individuals (including 40 females) in the medical wards. Twenty six had fever ranging from 37.3 degrees C to 40.5 degrees C while the rest had normal temperature. Although the oral temperature was higher than axillary temperature in all the cases, there was no correlation between the two; in one case the difference was as high as 1 degrees C. We conclude that while recording temperature the site must be clearly stated, and no attempt must be made to extrapolate the axillary to the oral temperature.

Adolescent↗

PubMed1990

Post heparin lipoprotein lipase activity in patients of ischaemic heart disease and in controls.

A single high fat meal diet (66 gm fat) was given to 30 healthy males and 20 male patients of ischaemic heart disease (IHD). Ten minutes prior to the 4th postprandial hour, 500 units of heparin--a lipoprotein lipase (LPL) activator--was given, and its effect seen on serum triglyceride (STG) levels observed. Besides higher fasting STG levels, the decline in 4 hour post-prandial STG level was significantly lower in patients of IHD. One explanation for higher fasting STG values and prolonged postprandial lipaemia in these subjects could be deficient LPL activity.

Adult↗

PubMed1990

Establishment of human retinal pigment epithelial cell lines by oncogenes.

The primary human retinal pigment epithelial cells were transfected with oncogenic sequences derived from viruses and cellular homologues of retroviral oncogenes 'protooncogenes' linked to simian virus 40 (SV-40) and retroviral promoters. Foci of cells were noted between 2 to 4 weeks after transfection. Individual colonies of cells were expanded from cultures transfected with SV-40 virion DNA, SV-40 large T antigen gene, Ha-ras oncogene, human and mouse c-myc and adenovirus E1A gene. Established cell lines tested were positive for the specific oncogene sequences by Southern hybridization and also expressed the protein as assayed by immunofluorescence and immunoblot analysis. Cell lines established with SV-40 large T antigen, and SV-40 virion DNA, exhibited epithelioid morphology up to the 25th passage and later became more rounded. However, all cell lines established with other oncogenes continued to retain epithelial morphology. Functional analysis of the cell lines demonstrated the presence of polarity and the ability to phagocytize rod outer segments, characteristics of retinal pigment epithelial cells. The use of oncogenes with immortalization/transformation potential may allow the establishment of cell lines from ocular tissues for analysing the biochemical basis of a disease like retinitis pigmentosa.

Antigens, Polyomavirus Transforming↗

PubMed1990

Outcomes of surgery for colorectal cancer in patients age 80 years and older.

Three hundred patients treated for colorectal cancer during the period 1975-1980 were divided into two groups (less than 80 yr, 236; greater than or equal to 80 yr, 64). No statistically significant differences were seen between the two groups for American Joint Committee on Cancer (AJCC) stage, site, and length of stay. Operative mortality (30 days) was associated with type of treatment (p less than 0.01), stage (p less than 0.05), and age (p less than 0.01) but not with site of cancer. Five-year survival curves excluding 30-day mortalities showed no significant difference between the two age groups. Proportional hazards linear model (multivariate) analysis showed that, whereas 5-yr survival was related to stage (p less than 0.001) and type of operation, patients greater than or equal to 80 did not have a significantly greater risk of death than patients less than 80 yr. Since the age of the patient influences operative morality, but not 5-yr survival, increasing attention needs to be paid to minimizing operative risk by careful preoperative assessment, optimization of underlying cardiac, pulmonary, and nutritional deficiencies, and monitoring numerous physiologic variables during the intraoperative and postoperative period. Resection of cancer should not be limited or denied on the basis of age alone.

Adenocarcinoma↗

PubMed1990

Ancylostoma ceylanicum: ATP production and effect of anthelmintics.

Dicarboxylic acids and a few amino acids were found to support mitochondrial phosphorylation in A. ceylanicum. Anaerobiasis markedly reduced this activity. Maximum effect was observed on succinate supported phosphorylation which in anaerobic atmosphere yielded only 2% ATP compared to that in the presence of air. Known as well as candidate anthelmintics significantly inhibited ATP formation. Mebendazole, amongst them, registered greatest effect. Oxygen consumption by the mitochondria exhibited poor response to the action of anthelmintics other than praziquantel.

Adenosine Triphosphate↗

PubMed1989

Opsin distribution and synthesis in degenerating photoreceptors of rd mutant mice.

The distribution of opsin and the capacity of photoreceptors to synthesize opsin was studied in retinas of mice bearing the rd (retinal degeneration) mutation and compared to control normal mice. Opsin was localized by means of pre-embedding and post-embedding immunocytochemistry and electron microscopy. Cones were identified with anti-cone antibodies and peanut agglutinin lectin which labels cone matrix sheaths. Opsin synthesis was measured by incorporation of [35S]methionine into opsin which was detected by immunoblots. Immunocytochemistry revealed that degeneration of rod outer segments was accompanied by accumulation of opsin in the plasma membrane enveloping the inner segment, nuclei and synaptic terminals. Rod photoreceptors degenerated faster than cones. By post-natal day 19 (P19), 87% of the remaining inner segments were cones. Opsin synthesis in rd mice could no longer be measured after P15. However, opsin molecules could be detected both by immunocytochemistry and immunoblotting up to P30. Between P20 and P30 all detectable opsin was localized in the plasma membrane which envelopes nuclei and synaptic terminals. Unlabeled surviving nuclei after P30 are probably cones. The opsin which is detected in rod inner segment plasma membranes might be derived, by back diffusion, from degenerating outer segments and represent molecules synthesized at an earlier time. Alternatively opsin accumulation might be a result of low levels of opsin synthesis, undetectable by [35S]methionine incorporation, which continues in the absence of outer segments.

Animals↗

PubMed1989

Fetal foot length--a new parameter for assessment of gestational age.

Ultrasonographic measurement of fetal foot length, a new parameter, was correlated with the gestation age. One hundred and five ultrasonographic measurement of fetal foot length was performed between 13 and 42 weeks gestation. Comparison of linear regression of foot length versus gestational age demonstrated a strong correlation with an r2 value of 0.84 (P less than 0.001). Ninety-five percent confidence intervals at each week compared favorably with both biparietal diameter and femur length data. Mean foot lengths at each week of gestation compared favorably with data based on pathological specimens described in 1920 (Streeter GL: Weight, sitting height, head size, foot length and menstrual age of the human embryo. Contrib Embryol Carnegie Inst. 11: 143, 1920). Measurement of fetal foot length is of particular use when other parameters do not accurately predict gestational age, e.g. hydrocephalus, anencephaly, short limb dysplasia. It can also be used in conjunction with biparietal diameter and femur length in the management of patients with premature labor in order to patients with premature labor in order to accurately predict gestational age. Hence the present study demonstrates that the ultrasonographic measurement of foot length is a reliable indicator of gestational age.

Embryonic and Fetal Development↗