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Biomedical subjects

M Singh

Publications and source records attributed to M Singh.

At least 721 records · Page 40Linked to original sources
PubMed1992

Hemodynamic responses during acute normovolemic hemodilution in anesthetized dogs.

Acute normovolemic hemodilution was induced by progressive replacement of blood by dextran (molecular weight 150,000) in anesthetized artificially ventilated dogs. Experiments were performed on dogs with intact autonomic innervation, dogs with beta-adrenergic blockade, dogs with cholinergic blockade, dogs with bilateral vagotomy, and dogs with combined bilateral vagotomy plus beta-adrenergic blockade. Hemodilution induced an increase in cardiac-output in all the groups. However, in dogs with low control heart rate (dogs with intact autonomic innervation, and dogs with beta-adrenergic blockade), cardiac-output increase was almost wholly due to an increase in heart rate. Whereas, in dogs with high control heart rate (dogs with cholinergic blockade, dogs with bilateral vagotomy, and dogs with combined bilateral vagotomy plus beta-adrenergic blockade), the increase in cardiac-output was almost wholly due to an increase in the stroke-volume. The increase in heart rate in dogs with intact autonomic innervation was not significantly different from the heart rate increase in dogs with beta-adrenergic blockade. In dogs with low control heart rate (beta-receptor blockade), hemodilution induced tachycardia, which was not significantly different from the response induced in intact dogs. This shows that the cardioacceleration was primarily mediated through the efferent vagus nerves, and the efferent sympathetic nerves did not make significant contribution in the reflex.

Animals↗
PubMed1992

Milk yields and hormone concentrations of Holstein cows in response to sometribove (somatotropin) treatment during the dry period.

Holstein cows (n = 135) under commercial management were used to determine whether sometribove (recombinant methionyl bST, 25 mg/d) administered during the dry period affected milk yield during the ensuing lactation. Cows scheduled to begin lactations (greater than or equal to 2) during January to March were assigned randomly to treatments of sodium bicarbonate excipient (n = 67) or bST (25 mg/d, n = 68). Subcutaneous injections were given for 14 d, corresponding to d -21 to -7 relative to expected calving date. Days dry prior to first injection (64.0, 60.2) and number of injections received (13.9, 13.8) were similar for control and treatment groups, but days from last injection to calving (8.8, 7.1) differed. No differences in incidence of dystocia or udder edema were detected. Previous lactation yields were 8251 and 7952 kg, and yields for lactations following treatment were 8328 and 7852 kg, based on complete lactation data. Mean test date 3.5% FCM yields for control and treated groups during experimental lactation differed before (30.3 vs. 28.1 kg) but not after (29.5 vs. 28.4 kg) covariance adjustment for previous total lactation milk yield. Test of heterogeneity of regression provided no evidence that respective curves for FCM yield during lactation were not parallel or of different magnitude. Elevation of serum bST during 2 wk of the dry period resulted in no apparent increase in extent of mammogenesis or lactogenesis that was translated into an increase in milk yield.

Animals↗
PubMed1992

Effects of maternal labetalol on the newborn infant.

Forty eight neonates, born to mothers suffering from pregnancy induced hypertension and receiving labetalol for control of blood pressure, were studied for the possible adverse effects of the drug. These were compared with eighty one neonates matched for gestation and weight and born to mothers with pregnancy induced hypertension treated with drugs other than labetalol. Incidence of birth asphyxia and intrauterine growth retardation (IUGR) in the study population was 10.4 and 22.9%, respectively and in the control group 5 and 19.7%, the difference between two groups was not statistically significant (p > 0.05). However, the incidence of hypoglycemia was significantly higher (p < 0.01) in the study group (47.9%) as compared to the control group (17.2%). Two-thirds of the hypoglycemic babies in the study population were asymptomatic and they were managed with sugar-fortified milk feeds. In the study population, the symptomatic hypoglycemic babies had hypoglycemia for prolonged duration of 43.3 +/- 23.3 hours as compared to 11.5 +/- 6.3 hours in symptomatic hypoglycemic babies of the control group (p < 0.01). The mothers of the symptomatic babies in the study group received higher doses of labetalol in the range of 287.6 +/- 142.3 mg/day while rest of the mothers in the same group whose babies had either asymptomatic hypoglycemia or normal blood glucose levels, received 239.5 +/- 118.5 mg/day, though the difference was not statistically significant. It is concluded that maternal labetalol therapy is associated with increased risk of neonatal hypoglycemia.

Asphyxia Neonatorum↗
PubMed1992

Prevention of hypoglycemia: a controlled evaluation of sugar fortified milk feeding in small-for-gestational age infants.

The study population included 110 term healthy small-for-gestational age (SGA) infants having a blood sugar of > 30 mg/dl at the age of < 30 minutes. They were randomized into two groups; (a) Group I (study group) received sugar-fortified milk formula and (b) Group II (control group) received standard milk formula. A minimum of 80 ml/kg/24 hour of milk was given. The first feeding was given within 45 minutes of birth and subsequently at 2 hours of age and then every 2 hourly till the age of 24 hours. The blood sugar (initial within 30 minutes of birth) was monitored at the age of 2, 4, 12 and 24 hours by dextrostix. The babies on fortified feeds received significantly (p < 0.001) higher amount of carbohydrate (8.1 mg/kg/min) as compared to those on standard milk (5.1 mg/kg/min). The incidence of hypoglycemia was reduced significantly (p < 0.01) by the sugar-fortified feeds. The mean blood sugar level in babies receiving fortified feeds was significantly higher at all the ages as compared to those receiving standard feeds. Nearly all the babies who subsequently developed hypoglycemia had a preceding blood sugar value of less than 60 mg/dl. The study highlights that sugar-fortified milk feeds are useful in preventing hypoglycemia in SGA infants and should be routinely recommended along with breast feeding in developing countries especially when facilities for monitoring of blood sugar are unsatisfactory or not available.

Blood Glucose↗
PubMed1992

Enterotoxigenic drug resistant plasmids in animal isolates of Escherichia coli and their zoonotic importance.

A study was undertaken to determine how widely drug resistant enterotoxigenic plasmids are distributed among the animal isolates of Escherichia coli, and their potential for exchange. Thirty-one strains of E. coli isolated from metritis, septicaemia and diarrhoea of animals were tested for the production of enterotoxins. Thirteen strains were enterotoxin producers. Five produced heat-stable enterotoxins (ST), four heat-labile (LT) and four strains produced both (LT/ST) types of enterotoxins. Most of the enterotoxin producing E. coli strains were isolated from diarrhoeal sources, followed by septicaemia and metritis. Of the 13 enterotoxigenic E. coli, nine were resistant to various antibiotics which transferred their drug resistance partially or completely into an E. coli K-12 recipient. Only one strain of serogroup 032, isolated from equine metritis, transferred ampicillin, oxytetracycline and doxycycline resistance and heat-labile enterotoxin biosynthesis determinants en bloc. Plasmid DNA analysis of the exconjugants showed the presence of a 41.8 MDa conjugative plasmid. The presence of such autotransferable enterotoxin biosynthesis replicons in their unusual ecological niches such as metritis and septicaemia suggests the ubiquitous nature of enterotoxin genes which perhaps were selected and spread due to the presence of genes for drug resistance. The potential of cross-infection of human beings from animals and vice versa via such plasmids is discussed.

Animals↗
PubMed1992

Course of antibody production by the DIG-ELISA method in neonatally infected and juvenile infected rats after primary infection with Breinlia booliati (Filarioidea: Onchocercidae).

The course of antibody production in Wistar neonatal and juvenile rats after primary infection with Breinlia booliati was studied by the DIG-ELISA technique using filter papers impregnated with capillary blood drawn from the infected rat tails at 7, 14, 28, 60 and 90 days post infection. Sera of neonatally infected rats did not react with adult worm antigen until day 7 and the titers of antibody remained at very low levels for the next 7 days. There was little tendency to eliminate the filarial larvae during this time. The antibody levels then rose rapidly throughout the next fortnight and increased to a maximum at day 60 after which the titer leveled out at a constant high value until early patency at day 90. On the other hand, antibodies could be detected in sera of juvenile infected rats as early as day 7 and the levels of antibody rose markedly to a maximum at day 28. During the period from day 60 to day 90 at early patency, the antibodies declined gradually to lower levels. The humoral immune responses of 42 neonatally infected rats and 53 juvenile infected rats of 3 strains (Lewis, Wistar and Sprague Dawley) were tested against soluble B. booliati antigens from both female (1:50) and male (1:10) worm extracts by the DIG-ELISA method. Antibodies were detected in sera from all the microfilaremic and amicrofilaremic rats belonging to neonatally and juvenile infected groups. Sera of clean neonatal rats did not give a positive reaction zone.

Age Factors↗
PubMed1992

Angiomyolipoma of kidney.

Angiomyolipoma is an uncommon benign tumour accounting for less than 1% of all surgically excised tumours of the kidney. It may present as an isolated lesion or in association with tuberous sclerosis. An impalpable tumour is often detected incidentally during investigation of a case for some urinary tract pathology. CT scan has proved to be a useful investigation for pre-operative diagnosis; it may however, be of no value if the fat content of the tumour is low. Here a case of angiomyolipoma of left kidney is reported where pre-operative diagnosis was suggested by CT scan and histopathology confirmed it.

Female↗
PubMed1992

The effects of recombinant human erythropoietin on the cell mediated immune response of renal failure patients.

Recombinant human erythropoietin (rHuEpo) is now widely employed in correction of the anemia of end stage renal disease (ESRD). Recent reports suggest that rHUEpo, in addition to its effect on CFU-E and burst-forming-unit-erythroid (BFU-E), may stimulate granulocyte/macro-phage production and pluripotential progenitors of the myeloid and monocyte lineage. Furthermore, there is now data which demonstrate that ESRD patients who received rHuEpo have enhanced cytokine production. Taken together, these observations suggest that the administration of rHuEpo may augment the diminished immune response of renal failure patients. To evaluate the effects of rHuEpo therapy on cell-mediated immunity in hemodialysis patients, a prospective controlled study was conducted. Two parameters of immune function were tested. One was natural killer cell (NK) activity, and the other proliferation in response to the T cell mitogen concanavalin A (Con-A). NK activity of the ESRD patients was comparable with that of normal controls at the start of the study and was unaffected by rHuEpo therapy. In contrast to this, anemic ESRD patients initially demonstrated impaired mitogen driven proliferation (initial stimulation index (S.I.) = 42.5 +/- 11.9) which significantly improved following rHuEpo therapy (final S.I. = 73.3 +/- 14.7, p < 0.05). The later value exceeded the mitogen response in less anemic ESRD patients who did not receive rHuEpo (initial S.I. = 60.7 +/- 16.5, final S.I. = 61.0 +/- 16.7), but did not reach values seen in normal controls. The data suggest that rHuEpo therapy may be associated with enhanced immune responses in patients with ESRD.

Aged↗
PubMed1992

Effect of Magic Johnson's HIV status on HIV-related attitudes and behaviors of an STD clinic population.

This paper reports data on the effects that Earvin "Magic" Johnson's announced HIV infection had on the clients of an Philadelphia sexually-transmitted-disease (STD) clinic. Interviews conducted after Johnson's announcement (N = 148) included questions about whether respondents had heard his announcement and how this news had influenced their sexual attitudes and behaviors. The findings include comparisons of matched samples (N = 138) of respondents interviewed before and after the news. The comparisons focused on 3 areas related to the human immunodeficiency virus (HIV): 1) passive concern; 2) sense of personal risk; and 3) resolve to be tested for HIV in the next 6 months. A significantly greater percent (92%) of the postannouncement respondents reported planning HIV tests than did the preannouncement respondents (52%). Although the differences in perceived risk were not statistically significant, 25% of the preannouncement and 34% of the postannouncement respondents indicated high perceived risk for HIV. Forty-four percent of the postannouncement sample indicated that, as a result of the news, they were now using condoms; 32% reported no effect; and 54% reported a variety of behavior changes that included monogamy (21%), greater selectivity (10.6%), fewer sexual partners (9.2%), and abstinence (3.5%). Overall, the announcement by Magic Johnson that he had been infected with HIV was associated with increased concern about HIV and with attitude and behavior changes that would lead to reduced risk. This was especially true for those in the sample at relatively higher risk.

Adult↗
PubMed1992

A new transport incubator for primary care of low birth weight babies.

A new portable, cheap and indigenous incubator made of polystyrene has been devised for delivery of primary health care services to the newborn babies in the community. Twenty six babies with a mean weight of 1726 g (range 1388-1981g) and gestational age of 35.3 weeks (range 34-38 wks) were continuously evaluated for 2 hours observation period, in naked and clothed conditions. Rectal, abdominal skin, foot, ambient air and nursery temperatures were recorded. The baseline core temperature of the babies was 36.58 (+/- 0.21) degrees C; after incubator care it was recorded s 36.80 (+/- 0.10) degrees C in naked infants. The baseline core temperature of the clothed babies was 36.63 (+/- 0.21) while it was 37.01 (+/- 0.18) after 2 hours of incubator care. An ambient air temperature of 33-34 degrees C in the incubator (thermoneutral temperature range for these babies being 31.0-33.8 degrees C) was achieved within 30-60 minutes of incubator stay (nursery temperature being 28 +/- 0.6 degrees C). No evidence of carbon dioxide narcosis, hypoxia, acidosis, or adverse thermoregulatory behavior was observed. One baby had hypoglycemia (blood sugar less than 35 mg/dl) and another had sweating. There is a scope for providing additional facilities like administration of oxygen, phototherapy, X-rays through the incubator without disturbing the baby.

Body Temperature Regulation↗
PubMed1992

Ultrastructure of murine cardiac ganglia in experimental Chagas' disease.

Albino mice, infected with Trypanosoma cruzi (Tulahuen strain) were sacrificed on days 7, 9, 12, 14, 16, 18, 21, 32 and 39 following infection. Transmission electron microscopic examination of the cardiac ganglia revealed no ultrastructural change at day 7. At day 9 there was peri- and intraganglionic monocytic infiltration but parasites were absent. Between days 12 and 16 there was intense monocytic infiltration, with intra-ganglionic presence of parasites within fibroblasts, monocytes and macrophages. None were seen within capsular cells, endothelial cells, Schwann cells, satellite cells and ganglion cells. The Schwann cells and satellite cells, however, showed phagocytic activity. Satellite cells were also reactive with proliferative pseudopodia which encircled neuronal processes. By day 18, parasites were absent in the ganglia. But monocytes were still present up to day 39, some of them still engulfing satellite cell and neuronal processes. Satellite cells continued to be reactive and Schwann cells phagocytic. Ganglion cells remained normal throughout the experiment. The results suggest that infection of Schwann cells, satellite cells and ganglion cells may depend upon the tissue tropism of the strain of the parasite used and its concentration in the inoculum. The results are consistent with the view that any parasympathetic dysfunction in experimental Chaga's disease in the mouse may be of a transient nature.

Animals↗
PubMed1992

Assessment of newborn baby's temperature by human touch: a potentially useful primary care strategy.

Fifty healthy term neonates delivered at All India Institute of Medical Sciences Hospital were assessed by three pediatricians for skin temperature to the nearest +/- 0.5 degrees C at the three body sites, i.e., mid-forehead, abdomen and dorsum of right foot by touch. The predicted temperatures at different sites were compared with simultaneously recorded temperatures at the same sites with the help of an electronic thermometer having a sensitivity of +/- 0.1 degree C. Rectal temperature was also recorded in all the babies with a rectal thermister to compare the variations between the core and skin temperatures. There was a good correlation between the skin temperatures of the babies as perceived by touch and values recorded with the help of an electronic thermometer. All the hypothermic babies were correctly picked up by all the observers. There was good correlation between core temperature and skin temperature at different sites except forehead. It is amazing that even during the month of May, when ambient temperature was maintained between 26-28 degrees C, nearly one fifth of the healthy term babies were under cold stress as evidenced by greater than 2 degrees C difference between the core and peripheral skin temperatures. It is recommended that health professionals and mothers should be explained the importance of evaluating the core and peripheral skin temperature by touch for early identification of babies under cold stress in order to prevent occurrence of life threatening hypothermia.

Abdomen↗
PubMed1992

Neonatal hypoglycemia--clinical profile and glucose requirements.

A total of 2248 infants born at All India Institute of Medical Sciences Hospital, New Delhi were selectively screened for hypoglycemia over a period of 15 months. Hypoglycemia (blood glucose less than 30 mg/dl) was diagnosed in 107 cases (4.8%). Preterm babies had three times increased risk (12.8%) as compared to term babies (3.6%). Small-for-dates (SFDs) and large-for-dates (LFDs) infants were at increased risk of manifesting hypoglycemia (7 and 10 times, respectively) as compared to the appropriate-for-dates (AFDs) babies (2.7%). Approximately two-thirds of the hypoglycemic babies (67.3%) had one or more risk factors including birth asphyxia (24.2%), diabetic mothers (23.8%), respiratory distress (13.9%) and septicemia (11.6%). A total of 59.8% cases were asmyptomatic while the rest had one or more symptoms. The most common symptom observed was lethargy (81.4%), followed by jitteriness (67.4%), respiratory abnormalities (41.9%), hypotonia (39.5%) and seizures (30.2%). The amount of glucose (mg/kg/min) needed to maintain a stable blood sugar in various categories of hypoglycemic babies was observed to be in the following decreasing order of amount; symptomatic babies with seizures (Gp IV), IGDM's/IDM's and symptomatic babies with other features (Gp III), SFDs and LFDs (Gp II) and AFDs (Gp I). Such a categorization of hypoglycemic babies will help to treat them more precisely.

Birth Weight↗
PubMed1992

Spectrum of neonatal hyperbilirubinemia: an analysis of 454 cases.

A prospective study of 454 newborn babies with pathological hyperbilirubinemia revealed that in about one-third of cases (34.6%), no cause could be identified despite detailed investigations. Nearly three-fifth of infants (62.5%) had hyperbilirubinemia due to hemolytic causes. On the basis of four variables, i.e., peak serum bilirubin level, age of attaining the peak level, age of starting phototherapy and total duration of phototherapy, the cases of hyperbilirubinemia can be categorized into three groups: (a) Group I (mild) included non-hemolytic hyperbilirubinemia, i.e., idiopathic, bacterial infections, intrauterine infections and others, (b) Group II (moderate) comprised of hemolytic as well as non-hemolytic hyperbilirubinemia due to prematurity, administration of oxytocin, bruising/cephalhematoma, and (c) Group III (severe) comprised of hyperbilirubinemia due to hemolysis as a result of blood group incompatibility between the mother and the neonate and G-6-PD deficiency. Sixty six babies required exchange blood transfusion (EBT) and a total of 100 EBTs were performed. Most of the babies (80.3%) requiring exchange blood transfusion belonged to Group III. The most common cause of hemolytic hyperbilirubinemia needing exchange blood transfusion was Rh isoimmunization followed by G-6-PD deficiency and ABO isoimmunization. There was no death attributable to the procedure of exchange blood transfusion.

Female↗