Search PubMed⌕ Search

Biomedical subjects

R Schwartz

Publications and source records attributed to R Schwartz.

At least 271 records · Page 15Linked to original sources
PubMed1984

The reticular pattern as a radiographic sign of the Barrett esophagus: an assessment.

A two-part retrospective study was conducted to assess the value of a reticular pattern as a sign of columnar-lined esophagus. Radiographic, endoscopic, and histologic findings were reviewed in 124 patients with known Barrett esophagus; then all barium esophagrams done at our institution during a 3 1/2 month period were reviewed and presence of a reticular pattern was correlated with available endoscopic and histologic data. In patients with known Barrett esophagus, the reticular pattern was found in 26% of double-contrast examinations. Twelve of these patients underwent careful esophageal mapping biopsies: the pattern was in squamous mucosa with ulceration in two, in columnar epithelium with ulceration in six, and in columnar epithelium without ulceration in four. In the group of 314 unselected patients who had double-contrast examinations, the reticular pattern was found in 26 (8%). Thirteen of the 26 had had endoscopy and biopsy: the site of the pattern was located in a squamous carcinoma in one, in squamous epithelium adjacent to squamous carcinoma in three, in squamous epithelium with esophagitis in five (two of whom had columnar mucosa distally), in normal squamous mucosa in one, and in columnar epithelium with esophagitis in three. The reticular pattern is a strong indicator of important esophageal disease, but is not specific for Barrett esophagus.

Barrett Esophagus↗
PubMed1984

Somatomedins and insulin in diabetic pregnancies: effects on fetal macrosomia in the human and rhesus monkey.

The concentrations of the somatomedins (SMs) insulin-like growth factors I and II (SM-C/IGF-I and IGF-II) were measured by RIA in six normal and seven insulin-dependent diabetic pregnant women and their infants at delivery. SM-C/IGF-I and IGF-II levels in the two groups of women were similar. Maternal IGF-II concentrations correlated with maternal hemoglobin AIc levels (r = 0.68) and infant birth weight ratios (actual birth weight/expected 50th percentile sex-corrected birth weight for gestation age; r = 0.54). SMC/IGF-I and IGF-II levels in umbilical plasma in infants of diabetic mothers did not differ from those in control infants, but were lower than the corresponding maternal values. In contrast, umbilical plasma levels of C-peptide immunoreactivity were significantly elevated in the infants of diabetic mothers (2.25 +/- 1.85 (+/-SD) vs. 0.34 +/- 0.15 pmol/ml; P less than 0.01). The infant birth weight ratio was logarithmically correlated with the umbilical plasma C-peptide immunoreactivity (r = 0.78). SM levels were also measured by radioreceptor assay in five normal and five hyperinsulinemic rhesus monkey fetuses. When chronic hyperinsulinemia was produced by continuous SC infusion of insulin in the fetal rhesus monkey, the fetal birth weight ratio was also found to be logarithmically correlated with the fetal plasma insulin concentration (r = 0.81). The fetal SM peptide content was elevated only in the fetuses with plasma insulin levels greater than 3000 microU/ml. The fetal weight gains in response to hyperinsulinemia in the human and rhesus are similar. Since fetal SM levels in the humans and monkeys were not significantly different in the two groups, our data suggest that insulin plays the predominant role in stimulating human and subhuman primate excess fetal weight gain of the infant of the diabetic mother during the latter part of gestation.

Adult↗
PubMed1984

The undesirable effects of various changes of monoplane occlusion on complete denture retention.

The most commonly seen undesirable alterations to the occlusal plane, when using monoplane occlusion with nonanatomic teeth, have been outlined verbally and graphically. The introduction of dislodging forces to denture retention brought about by these variations in the monoplane have been examined, as well as methods for their correction. The order of presentation of undesirable alterations to the occlusal plane is a guide for a step-by-step correction of these changes. It provides the practitioner with a sequential checklist for correcting undesirable occlusal changes in monoplane denture occlusion with nonanatomic teeth.

Dental Occlusion, Balanced↗
PubMed1984

Chronic hyperinsulinemia in the fetal rhesus monkey. Effects of physiologic hyperinsulinemia on fetal growth and composition.

One of the hallmarks of the hyperglycemic-hyperinsulinemic infant of the diabetic mother (IDM) is macrosomia and selective organomegaly. Primary hyperinsulinemia, with insulin levels similar to those observed in human IDMs at delivery, was produced in the fetal rhesus monkey during the last third of gestation. The effects of this physiologically relevant hyperinsulinemia, in the absence of hyperglycemia, on fetal growth were studied. Fetal macrosomia, with a 23% increase in total body weight, was observed in physiologically hyperinsulinemic fetuses. A similar 27% increase in weight was produced by fetal insulin levels that were 10 times higher. A logarithmic correlation was observed between fetal birth weight ratio and fetal plasma insulin concentration. In contrast to this increase in weight, skeletal growth, as measured by crown-heel length and head circumference, was not affected by hyperinsulinemia. Only cardiomegaly was found in the low-dose hyperinsulinemic fetuses, whereas cardiomegaly, hepatomegaly, and splenomegaly were produced by hyperinsulinemia in which insulin levels were in the highest range. Compositional analysis of heart and skeletal muscle indicated no differences in the protein, RNA and DNA concentration, or in the protein-to-DNA ratio in hyperinsulinemic fetuses. We interpret these data as indicating that fetal insulin plays the predominant role in controlling the normal, as well as the augmented, fetal weight characteristic of the human infant of the diabetic mother.

Animals↗
PubMed1984

Glucose kinetics in glucose-infused small for gestational age infants.

To evaluate the maturation of glucose homeostasis in the small for gestational age (SGA) neonate, glucose kinetics were measured with 78% enriched D-[U-13C]glucose by the prime plus constant infusion technique in nine SGA infants and compared with the rate obtained in seven term appropriate for gestational age infants and 13 preterm appropriate for gestational age infants. All of the infants had received glucose intravenously from birth and continued to receive the glucose infusion throughout the study. Fasting plasma glucose and plasma insulin concentrations and plasma [13/12C]ratios were measured during the steady state turnover period. From this data, the glucose production rate was derived. During the turnover period, the SGA and both groups of appropriate for gestational age infants had similar average plasma glucose, plasma insulin, plasma glucagon concentrations, and similar persistent rates of glucose production during glucose infusion. We conclude that under stimulation of glucose infusion, the SGA infant and his AGA counterpart have similar hormonal regulatory responses as well as functional integrity in handling glucose during the second day after birth.

Blood Glucose↗
PubMed1984

Comparison of resting capillary flow dynamics in the finger and toe nailfolds.

The purpose of this study was to compare capillary dynamics in the nailfold regions of the human toes and fingers. Capillary blood flow velocity (VEL), vessel diameter, the total number of capillaries and the number of capillaries with active flow per mm2 of tissue were measured in the toe nailfold region of 17 and in the finger nailfolds of 15 male subjects 20 to 40 years of age. All measurements were made in the rest state at a skin temperature of 32 degrees C. Group averages were: (Formula: see text). These results demonstrate that compared to the finger the nailfold capillaries in the toe have a lower blood flow per vessel but a much higher capillary density. The combination of these factors indicates that total capillary blood flow is higher in the toe nailfold system.

Adult↗
PubMed1983

Glucose kinetics in nondiabetic and diabetic women during the third trimester of pregnancy.

Glucose kinetics were measured with 78% enriched D-[U-13C] glucose by the prime constant infusion technique during the third trimester of pregnancy in nine nondiabetic women, nine insulin-dependent diabetic women, six gestational diabetic women, and five control women (nonpregnant, nondiabetic) after an overnight fast. The patients not dependent on insulin were diagnosed as diabetic by oral glucose tolerance tests with the use of O'Sullivan and Mahan's criteria as modified by Carpenter and Coustan during the third trimester. The turnover studies were repeated post partum (6 weeks to 5 months after delivery) in 14 of the 24 pregnant subjects. All pregnant groups had a progressive fall in plasma glucose concentration during the study, but there was a steady state of plasma glucose concentration during the turnover period. In comparison to the control subjects, both the pregnant nondiabetic and pregnant insulin-dependent diabetic women had significantly higher plasma insulin concentrations throughout the study (p less than 0.05). There were no differences in the glucose turnover rate between any of the pregnant groups (1.7 +/- 0.2 mg . kg-1 min-1 in pregnant nondiabetic women; 1.5 +/- 0.2 mg . kg-1 min-1 in pregnant insulin-dependent diabetic women; and 2.1 +/- 0.4 mg . kg-1 min-1 in gestational diabetic women) and the control group of women (1.8 +/- 0.2 mg . kg-1 min-1) (mean +/- SEM). When the pregnant patients were studied post partum, the glucose turnover rate was similar when referenced to body weight; however, because of a 9.6% to 14.5% fall in weight post partum, the absolute values were higher in the pregnant women. We conclude that, in the basal state after an overnight fast, (1) both nondiabetic and diabetic patients accelerated their glucose turnover rate during pregnancy to provide for increased maternal and fetoplacental metabolic requirements, and (2) in the diabetic subjects the nearly normal plasma glucose and insulin concentrations and other metabolic parameters, as well as the glucose turnover rate, suggested good metabolic control during pregnancy in most of the insulin-dependent and in all of the gestational diabetic patients.

Adult↗
PubMed1983

Glucose kinetics in infants of diabetic mothers.

Glucose kinetic studies were performed to define the glucose turnover rate with 78% enriched D-[U-13C] glucose by the prime constant infusion technique at less than or equal to 6 hours of age in nine infants of diabetic mothers (four insulin-dependent and five chemical diabetic patients) at term. Five normal infants were studied as control subjects. All infants received 0.9% saline intravenously during the study with the tracer. Fasting plasma glucose, insulin, and glucose13/12C ratios were measured during the steady state, and the glucose turnover rate was derived. The average plasma glucose concentration was similar during the steady state in the infants of the diabetic mothers and in the control infants, and the glucose turnover rate was not significantly different among the groups: 2.3 +/- 0.6 mg . kg-1 min-1 in infants of insulin-dependent diabetic patients; 2.4 +/- 0.4 mg . kg-1 min-1 in infants of chemical diabetic patients; and 3.2 +/- 0.3 mg . kg-1 min-1 in the control subjects. Good control of maternal diabetes evidenced by the normal maternal hemoglobin A1c and plasma glucose concentration at delivery and cord plasma glucose concentration resulted in glucose kinetic values in the infants of diabetic mothers that were indistinguishable from those of control subjects. The data further support the importance of good control of the diabetic state in the pregnant woman to minimize or prevent neonatal hypoglycemia.

Blood Glucose↗
PubMed1983

Actinomycosis infection associated with intrauterine contraceptive devices.

Papanicolaou-stained cervicovaginal smears from 478 women with intrauterine contraceptive devices (IUDs) in place were reviewed for the presence of Actinomyces colonies. The overall infection rate was 12.6%. Plastic IUDs had a significantly higher infection rate than that of Copper 7 IUDs. The infection rate was found to increase with the duration of use of IUDs. The presence or absence of Actinomyces was not related to age, race, parity, previous abortions, or financial status of the patients.

Actinomycosis↗
PubMed1983

Impermeability of the rat placenta to insulin during organogenesis.

The cause of the embryopathy associated with diabetes mellitus is uncertain. To examine whether exogenously administered insulin may be teratogenic, tracer amounts of radiolabelled insulin were infused for two hours during organogenesis (day 12 1/2 of gestation) into three groups of pregnant rats: control (n = 8), diabetic (n = 5), and hyperinsulinemic (n = 4). For maternal plasma, no differences were found among the three study groups in the percentage of the protein-precipitable (insulin-containing) radioactivity. Tissue radioactivities were expressed relative to the two-hour maternal plasma sample. Maternal kidney samples had the highest total and protein precipitable counts followed in descending order by the maternal plasma, maternal liver, placenta, and embryo. No differences in radioactivities were noted among the three study groups for specific tissues studied. Protein-precipitable radioactivities in the embryo were more than 100-fold less than the maternal plasma values. In 11 of the 17 litters, the acid-insoluble fractions of the embryos were not distinguishable from background counts, and none of the remaining six were greater than twice background. These studies demonstrate that during the period of organogenesis, the rat embryo is protected from maternal insulin by the placenta, and hence, maternal insulin is an unlikely teratogen.

Animals↗
PubMed1983

Prolactinomas as part of the multiple endocrine neoplastic syndrome type 1.

The pituitary tumors seen in the multiple endocrine neoplastic syndrome type 1 have generally been considered "nonfunctional." Fewer than 40 persons with hyperprolactinemia as part of the syndrome have been described. A family with the largest number of subjects (six) with prolactinomas in one generation reported to date is described. The variable aggressiveness of this disease, the difficulty in treatment because of multiple prolactinomas or hyperplasia or both, and a case of tumor shrinkage with bromocriptine therapy are also demonstrated in this unique family.

Adult↗
PubMed1983

[Confirmation of the T classification of bladder tumors by transcutaneous sonography, intra-vesical sonography and computer tomography].

Forty-two patients with carcinoma of the bladder were examined by intravesical and transcutaneous sonography, as well as by computed tomography, in order to determine their T-classification. None of these methods permitted a distinction between T2 and T3a as recommended by the UICC (1978), with any degree of certainty. Intravesical sonography is best for defining superficial tumours. Transcutaneous sonography has proved satisfactory for differentiating muscle-infiltrating from extravesical tumours. Computed tomography shows infiltration of tumour into the perivesical fat and into neighbouring organs; infiltration of tumour into the prostate cannot always be demonstrated.

Humans↗
PubMed1983

[Computer tomography of malignant renal lymphomas].

The pre- and postcontrast CT findings of 11 patients with lymphoma involving the kidneys are described. In all cases the renal lesions showed low attenuation values after bolusinjection. In contrary to the literature renal lymphoma might present different attenuation values in the non-contrast enhanced CT scan. The density varies from hypo- to iso- and hyperdens. A bolusinjection of contrast media should be performed to depict even greater nodules.

Adult↗
PubMed1983

Comparison of in vitro and in vivo measurements of dietary Ca exchangeability and bioavailability.

An in vitro method for measuring dietary mineral exchangeability (miscibility with an extrinsic isotopic tracer) was tested by comparison with in vivo measurements in rats. Collards, spinach and soybeans, intrinsically labeled with 45Ca, were fed to rats together with extrinsically added 47Ca. Absorption of both tracers was determined by measuring their concentrations in the femur 2 days after consumption of the labeled test meals. The same intrinsically and extrinsically labeled foods were digested in vitro for estimation of Ca exchangeability and solubility after peptic-pancreatic digestion. Corresponding in vivo and in vitro estimates of exchangeability agreed closely for the three foods tested. Solubility after in vitro peptic-pancreatic digestion (potential bioavailability) showed discrepancies. In vitro values were somewhat higher for collards than in vivo fractional absorption. The reverse was true for Ca in soybeans and spinach. Thus, the in vitro procedure appears adequate for measuring intrinsic dietary Ca exchangeability but requires modification if it is to be a reliable substitute for in vivo measurements of Ca bioavailability.

Animals↗