PubMed HealthSearch

Biomedical subjects

R L Bijlani

Publications and source records attributed to R L Bijlani.

At least 19 recordsLinked to original sources

Poor reliability of the first meal tolerance test.

The poor reproducibility of oral glucose tolerance test (OGTT) has been known for a long time. Some recent reports indicate that postprandial glycaemia achieved during the test is likely to be higher on the first occasion than on subsequent visits. We have analysed our recent data on meal tolerance tests (MTT) from this angle. Fifteen healthy subjects and 9 subjects having NIDDM were administered two essentially identical meals one or two weeks apart. In case of healthy subjects, the absolute as well as incremental postprandial glycaemia achieved at 0.5 h and 1.0 h on the first visit was significantly higher (P < 0.05) than on the subsequent visit. The effect of visit was insignificant in case of NIDDM subjects. The effect observed in healthy subjects may be due to the release of adrenaline during the first visit brought about by apprehension. In NIDDM subjects the apprehension is likely to be much less because of their having undergone such tests in the past. Hence a single casual OGTT or MTT is unreliable as a diagnostic tool in borderline cases of impaired glucose tolerance test. The test needs to be repeated at least once more to eliminate false positives.

Adult

Nutrient interaction in relation to glycaemic and insulinaemic response.

Although it is known that protein, fat and fibre reduce the postprandial glycaemia following an oral carbohydrate load, the nature and extent of interaction of different nutrients with one another in this respect is not well understood. The present study was designed to explore systematically the glycaemic and insulinaemic response to glucose (G) alone, or in combination with one or more of the following: casein (CS), maize oil (MO), cellulose (CL) and pectin (P). Besides 100 g G, eleven isoenergetic and six isocarbohydrate meals were studied on healthy adult males using an incomplete block design. Addition of other nutrients to G led to a lowering of the glycaemic response. The lowest glycaemic responses were seen in case of meals containing the largest number of nutrients. P was more effective in reducing postprandial glycaemia than CL. As in case of glycaemic response, low insulinaemic responses were also associated with P-containing meals, and meals containing the largest number of nutrients. But unlike in case of glycaemic response, there was a tendency for elevation of the insulinaemic response in case of CL-containing meals. The degree of attenuation of glycaemic response observed with meals containing several nutrients was roughly predictable on the basis of the attenuation observed with meals in which only one nutrient had been added at a time to G. But the glycaemic response of natural foods is unlikely to be predictable on the basis of their nutrient composition because of the overriding influence of several other factors such as physical form, cooking, processing, storage and antinutrient content of the food.

Adolescent

Effect of coingestion of paracetamol on glycaemic response.

Rate of gastric emptying is a frequently measured variable in glycaemic response studies. One of the indices employed for measurement of the gastric emptying rate is the blood level of paracetamol at frequent intervals of time following coingestion of paracetamol with the meal. But the effect of paracetamol itself on glycaemic response is not known. The present study was performed on ten healthy and five NIDDM subjects. Each subject underwent two meal tolerance tests in random sequence. On one occasion the meal was white bread; on the other occasion, the meal consisted of the same quantity of white bread and 1.5 g paracetamol. The postprandial glycaemica following the two meals was not significantly different. Thus the results validate the use of the paracetamol technique for gastric emptying in glycaemic response studies.

Acetaminophen

Modulation of postprandial glycaemia and insulinaemia by dietary fat.

The present study was designed to examine the effect of corn oil (Co) on postprandial glycaemia and insulinaemia when ingested with glucose (G), casein (Cs), cellulose (Cl) and pectin (P) in various combinations. The study was conducted on six healthy male volunteers, on each of whom six meal tolerance tests were performed. The meals were isocaloric and consisted of G; G and Co; G, Co and Cs; G, Co and P; G, Co, Cs and P; and G, Co, Cs and Cl. The meals were administered after an overnight fast. In addition to a fasting blood sample, blood was collected 0.5, 1.0, 1.5 and 2.0 h after ingestion for measurement of serum glucose and insulin levels. The glycaemic response to GCo was comparable to that to G, but the insulinaemic response was significantly lower. The glycaemic response to GCoCs was significantly lower than that to G but the insulinaemic response to both was comparable. The cellulose containing meal GCoCsCl showed a further reduction in the glycaemic response but not in the insulinaemic response. The pectin containing meals GCoP and GCoCsP gave the lowest glycaemic and insulinaemic responses, the responses to the latter being lower. Corn oil by itself has only a modest effect on the postprandial metabolic response to glucose. Addition of protein and fibre, specially pectin, leads to significant attenuation of glycaemic and insulinaemic responses.

Adult

Glycaemic response to maize, bajra and barley.

The postprandial glycaemic response to maize (Zea mays), bajra (Pennisetum typhoideum) and barley (Hordeum vulgare) was studied in a pool of 18 healthy volunteers and 14 patients having non-insulin-dependent diabetes mellitus (NIDDM). In response to maize, none of the variables examined was significantly different as compared to white bread. The glycaemic response to bajra was significantly lower than that to white bread in healthy subjects, but the two responses were indistinguishable in NIDDM subjects. The insulinaemic responses to bajra and white break were not significantly different in either group of subjects. The glycaemic response to barley was significantly lower than that to white bread in both groups of subjects. But the insulinaemic response to barley was significantly lower than that to white bread only in healthy subjects. In NIDDM subjects, there was a tendency for the response to barley to be higher than that to white bread 0.5 h after ingestion. Barley, with a low glycaemic index (68.7 in healthy and 53.4 in NIDDM subjects) and a high insulinaemic index (105.2) in NIDDM subjects seems to mobilize insulin in NIDDM. This makes it a specially suitable cereal for diabetes mellitus.

Adult

Nutrient interaction in relation to glycaemic response in isocarbohydrate and isocaloric meals.

The present study was designed to examine the effect of casein (Cs) on postprandial glycaemia when ingested with glucose (G) alone or in combination with corn oil (Co), cellulose (Cl) or pectin (P). The study was conducted on a pool of ten healthy male volunteers in two sets of five volunteers each. The meals administered in the two sets were similar in composition but were isocarbohydrate (100 g G) in one set, and isocaloric (400 kcal) in another set. The meals in each set consisted of G, G Cs, G Cs Co, G Cs Cl and G Cs P. Each of the five volunteers in a given set underwent five meal tolerance tests (MTT), once with each meal, in a Latin Square design. During the MTT, the meal was administered after an overnight fast. In addition to a fasting venous blood sample, blood was collected 0.5, 1.0, 1.5 and 2.0 h after ingestion for measurement of serum glucose and insulin levels. In both sets, the highest glycaemic response was that to G. In the isocarbohydrate set, G Cs gave a significantly lower glycaemic and insulinaemic response than G. Further addition of Co made no essential difference but both the fibre containing meals gave significantly lower glycaemic responses. The insulinaemic response was attenuated only in case of G Cs P but not in case of G Cs Cl. In the isocaloric set, Cs as G Cs was observed to stimulate insulin secretion rather than attenuate postprandial glycaemia G Cs Co gave a reduction in glycaemic as well as insulinaemic response as compared to G. Both fibre containing meals led to further reduction in both responses, P being somewhat more effective than Cl. Addition of other nutrients to G, in general, reduces postprandial glycaemia.

Adolescent

Modulation of postprandial glycaemia and insulinaemia by cellulose in mixed nutrient combinations.

The present study was designed to examine the effect of cellulose (CL) on postprandial glycaemia and insulinaemia when ingested with glucose (G), casein (CS) and maize oil (CO) in various combinations. The study was conducted on five healthy male volunteers, on each of whom five meal tolerance tests were performed. The meals were isoenergetic and consisted of G; G and CL; G, CS and CL; G, CO and CL; G, CS, CO and CL. The meals were administered after an overnight fast. In addition to a fasting venous blood sample, blood was collected 0.5, 1.0, 1.5 and 2.0 h after ingestion for measurement of serum glucose and insulin levels. The glycaemic response to G + CS + CL and G + CS + CO + CL was significantly lower, while the insulinaemic response to G + CL was significantly higher than that to G. Addition of CL to G did not alter the glycaemic response, but accentuated the insulinaemic response. Further addition of CS in isoenergetic meals attenuated the glycaemic response, which may be because of a reduction in the amount of G in the meals. Like CS, CL also seemed to have an insulinotropic effect. The mechanism of the insulinotropic effect of CL cannot be deduced from the present study, but it is possible that like G, CL also stimulates gastric inhibitory peptide (GIP) secretion from the duodenum, which in turn stimulates insulin secretion.

Adult

Nutrient composition is a poor determinant of the glycaemic response.

1. The glycaemic response of healthy males to potato, bread, rice and green gram (Phaseolus aureus Roxb.) was compared with that to meals equivalent to these foods in terms of carbohydrate, protein, fat and fibre content, but made up of maize flour, casein, maize oil and ispaghula husk. 2. Natural foods led to a higher postprandial glycaemia than their respective equivalents, but the difference was significant only in the case of potato at 0.5 h (P less than 0.05). 3. The insulin response, studied only in the case of rice and green gram, followed a trend similar to the glycaemic response but the differences between natural foods and equivalents were even more marked. 4. A food is more than the sum of its major nutrients. Several poorly understood factors may contribute to the glycaemic response to a food. In addition to the quantity of nutrients, the response may be the result of the specific type of nutrients, non-nutrient chemicals and anti-nutrients composing the food, and their unique physical arrangement within the food.

Adult

Objective structured practical examination: a new concept in assessment of laboratory exercises in preclinical sciences.

The objective structured practical examination (OSPE) was used as an objective instrument for assessment of laboratory exercises in preclinical sciences, particularly physiology. It was adapted from the objective structured clinical examination (OSCE). The OSPE was administered to two consecutive classes in conjunction with the conventional examination in which the candidate is expected to perform a given experiment. The scores of the students in the two components of the examination were used to compare the OSPE with the conventional examination and to evaluate the new instrument of assessment. The OSPE appears to be a reliable device with a good capacity for discriminating between different categories of students. It is better in these respects than the conventional practical examination. Moreover, it has scope for being structured in such a way that all the objectives of laboratory teaching can be tested and each aspect can be assigned the desired weightage.

Education, Medical, Undergraduate

Dietary fibre: consensus and controversy.

Technological advances have reduced and refined man's plant food intake and consequently brought about an unprecedented decline in his consumption of dietary fibre (DF). The emergence of certain diseases selectively in regions which have been affected the most by this dietary change has led to an enhanced awareness of the functions of DF. DF is a heterogeneous group of substances which resist digestion by the endogenous enzymes of the human gut, although they are fermented to a substantial extent by the bacterial flora of the large intestine. Chemically, DF essentially consists of nonstarch polysaccharides and lignin, and its major constituents are cellulose, hemicelluose, lignin and pectin. The physiological effects of DF are attributable largely to its physicochemical properties. DF primarily affects gastrointestinal (GI) function; its effects are observable at all stages from ingestion through defaecation. It restricts caloric intake, shows gastric and small intestinal transit, and affects the activity of digestive enzymes and release of GI hormones. Its overall impact is to reduce apparent digestibility of nutrients marginally but consistently. In the large intestine, DF accelerates transit, supports bacterial growth and serves to hold water. As a result, the faecal weight and water content increase, and the transit time generally becomes shorter. Secondary to its GI effects, DF attenuates postprandial glycaemia and has long term effects on glucose tolerance and lipoprotein metabolism. These effects have important implications in the aetiopathogenesis of constipation and its sequelae including diverticulosis, cholesterol gallstones, colorectal cancer, obesity, diabetes mellitus and atherosclerosis. DF has traditionally been used therapeutically for constipation; now its use in diabetes is also well established. Our appreciation of the role of DF in human nutrition has undergone a major change in the last two decades. From a redundant constituent of plant foods, it has now moved to the position of an essential nutrient, the deficiency of which seems to have serious consequences.

Animals

Assessment of Laboratory exercises in physiology.

Assessment is an integral part of the teaching-learning process. It contributes to the realization of learning objectives by inculcating habits which are conducive to better scores in the examination. A system of assessing laboratory work which combines the performance of experiments by the student with some short questions based on an instrument, experimental data or tracing has been critically examined. The performance of the student in the two parts of the examination is poorly correlated (r = 0.36 to 0.72), suggesting that they test different abilities, and that combining them may improve the objectivity of the examination. The overall practical assessment is better correlated with the overall theory assessment (r = 0.71, 0.87). The correlation between different forms of examination also improves when only the top 10% and bottom 10% of the class is considered. Since the results quoted are based on only a few examinations at a single medical school, generalizations are not justified.

Education, Medical, Undergraduate

The significance of some significant features of breast milk.

The composition of milk shows reasonable species variation. Further, the composition in a given mother changes with the stage of lactation. It appears reasonable to assume that nature arranges the secretion of milk of a composition which is best suited for an infant. The colostrum, secreted during the first five days of lactation, has higher concentration of total protein, lactoferrin, and immunoglobulins but lower concentrations of fat and lactose. The milk secreted from day 6 through 15 is called transitional milk because its composition is intermediate between that of colostrum and mature milk which follows. Even in mature milk, small changes in composition go on throughout lactation. Further, if the infant is preterm, the composition of milk is different, and its appears to be more suitable for the premature infant. A large number of biochemical differences are now known between human milk and animal milk. Although the significance of several of these differences is not known, enough is known to explain why breast milk is better digested and more protective against infections. Besides, some constituents of breast milk might also have a role to play in growth and metabolism of the infant.

Breast Feeding