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Biomedical subjects

S Kalhan

Publications and source records attributed to S Kalhan.

28 records · Page 2Linked to original sources
PubMed1991

Altered diastolic function in asymptomatic infants of mothers with gestational diabetes.

Left and right ventricular filling was studied prospectively in 50 full-term (39.4 +/- 1.3 wk) asymptomatic newborns of mothers with gestational diabetes mellitus (GDM). Their data were compared with those of 80 asymptomatic full-term (39.8 +/- 1.2 wk) infants who served as control subjects. Infants were examined in the immediate newborn period (less than 48 h) and then again at 2-4 and 6-9 wk. Although mean weight, length, and gestational age did not differ, the mean +/- SD left ventricular dimensions during diastole (1.73 +/- 0.15 vs. 1.81 +/- 0.18 cm, P = 0.007) and systole (1.22 +/- 0.15 vs. 1.31 +/- 0.17 cm, P = 0.004) were significantly lower in infants of mothers with GDM compared with control infants. Diastolic measurements suggested a shift from the early diastolic filling of the ventricle to the later period of atrial systole in infants of mothers with GDM. A lower initial one-third area fraction and a higher peak flow velocity and velocity time integral during atrial systole were noted at the mitral valve in infants of mothers with GDM. These changes had resolved by 2-4 wk of age. The altered diastolic filling patterns in infants of mothers with GDM indicate poor myocardial relaxation and/or decreased passive compliance of the ventricular myocardium. These alterations were observed in asymptomatic infants in the absence of left ventricular or septal hypertrophy. If exposed to significant stress such as asphyxia or sepsis, the observed myocardial dysfunction could lead to higher morbidity in these infants.

Adult↗
PubMed1987

Decreased fetal movements with sustained maternal hyperglycemia using the glucose clamp technique.

The purpose of this study was to evaluate the effect of sustained maternal hyperglycemia (120 mg/dl) on fetal activity. The glucose infusion study group was comprised of nine healthy gravidas between 36 and 40 weeks' gestation, and six patients served as controls. The protocol design included an overnight fast for all patients. Fetal movements were evaluated by external fetal monitoring. A 2-hour preinfusion evaluation of fetal activity served as the baseline control for each patient studied. Study patients then received a glucose infusion by a glucose clamp technique to maintain a sustained hyperglycemia of 120 mg/dl for 3 hours. After the glucose infusion, fetal movements were observed for 1 hour. Control patients received a saline infusion for 2 hours after a 2-hour baseline evaluation. Maternal hyperglycemia was associated with a significant decrease of fetal movements greater than 1 second duration during the first hour of glucose infusion. Fetal movements returned to baseline during the second and third hours of glucose infusion. Saline infusion was not associated with a decrease in fetal activity. We conclude that sustained maternal hyperglycemia is associated with a transient decrease in fetal movement during the first hour of glucose infusion followed by a return to the control (preinfusion) level of fetal activity. These data may have implications in the study of fetal behavior in diabetes mellitus.

Blood Glucose↗
PubMedDate not supplied

Altered diastolic function in infants of mothers with gestational diabetes: no relation to macrosomia.

In a previous study, asymptomatic infants of mothers with gestational diabetes (IGDMs) were observed to have altered left ventricular (LV) filling. In the present study, we reanalyzed the data to examine whether the observed abnormalities were related to maternal diabetes or due to the greater preponderance of macrosomic infants (32%) in the gestational diabetes group. No echocardiographic (systolic or diastolic) differences were observed when the data were compared in 16 large-for-gestational-age (LGA) and 24 appropriate-for-gestational-age (AGA) infants among IGDM. Comparison of 16 LGA IGDM and 17 LGA infants of control mothers revealed lower LV size during diastole and systole in the IGDM. The present analysis suggests that the cardiac alterations in the IGDMs are not due to the preponderance of macrosomia but, rather, the consequence of altered in utero metabolic environment.

Case-Control Studies↗
PubMedDate not supplied

Protein/amino acid metabolism and nutrition in very low birth weight infants.

A large number of studies in recent years have described protein and nitrogen metabolism in the neonate. However, the majority of these data are difficult to interpret because of a number of confounding variables, particularly in very low birth weight (VLBW) infants. In contrast, application of state-of-the-art tracer isotopic and molecular biology methods in isolated cell system and whole animals has resulted in major advances in our understanding of the regulation of protein breakdown, synthesis, and protein accretion. The following workshop summary reviews the recent developments in basic physiology of protein metabolism in cellular and animal models in relation to human preterm infants, and identifies the important areas toward which future basic and clinical research should be directed to provide for optimal nitrogen accretion and growth of the VLBW infant.

Amino Acids↗
PubMedDate not supplied

Determination of body composition in children and adolescents: validation of bioelectrical impedance with isotope dilution technique.

The determination of body composition as part of the clinical and auxologic follow up of childhood growth disorders necessitates the use of a quick, portable, reliable and simple non-invasive method. The present study was undertaken to validate bioelectrical conductance, height2/resistance (Ht2/R), against isotopically determined total body water (TBW) using heavy water tracer H2[18O]. The subjects (n = 56) consisted of normal children, children with various endocrine disorders, and young adults between the ages of 8-26 years. Isotopically determined TBW and fat free mass (FFM) were highly correlated with Ht2/R (r = 0.94, p = < 0.001, and r = 0.94, p = < 0.001, respectively). In a multiple regression analysis, 96% of the variability in FFM in normal subjects could be predicted by the following equation: FFM = 0.524 Ht2/R + 0.415 Wt-0.32, while in the group of patients by FFM = 0.659 Ht2/R + 0.254 Wt + 2.851. These data suggest that bioelectrical impedance measurements give valid and reliable estimates of FFM in children and adolescents. This easy technique could be incorporated in the auxologic follow up of children on hormone therapy.

Adolescent↗