Nutrition and breast cancer risk: can an effect via insulin resistance be demonstrated?

It is postulated that the metabolic/endocrine concomitants of insulin resistance resulting from high animal fat intake and weight gain after the age of 30 could be contributing to the increasing incidence of postmenopausal breast cancer and recent changes in its biologic characteristics. Case/control studies have shown that hyperinsulinaemia and abdominal obesity, which are recognized as markers of insulin resistance, are risk markers for postmenopausal breast cancer also. Excess weight gain linked to high dietary intake of saturated fat is thought to be a major cause of insulin resistance.

Very-low-birth-weight outcomes of the National Institute of Child Health and Human Development Neonatal Research Network, May 1991 through December 1992.

Objectives: Our goals were to determine the mortality risk for infants weighing 501 to 1500 gm according to gestational age, birth weight, and gender and to document birth weight-related changes in mortality and morbidity over a 5-year time period.

Study Design: In this observational study perinatal data were prospectively collected by the 12 participating centers of the National Institute of Child Health and Human Development Neonatal Research Network from May 1991 through December 1992 and compared with the corresponding data from 1987 through 1990. Standard definitions were used to record sociodemographic factors, perinatal events, and the neonatal course to 120 days of life, discharge, or death.

Inhibition of proteolysis by cell swelling in the liver requires intact microtubular structures.

In the perfused rat liver, proteolysis is inhibited by cell swelling in response to hypo-osmotic media, glutamine and insulin. Colchicine, an inhibitor of microtubules, did not affect cell swelling in response to these agonists. However, the antiproteolytic action of these effectors was largely blunted in the presence of colchicine or the microtubule inhibitors colcemid and taxol.

Pseudomonas aeruginosa infection in very low birth weight infants: a case-control study.

The perinatal histories and hospital courses of all neonates born at Grady Memorial Hospital who developed Pseudomonas aeruginosa sepsis or meningitis in the 5-year period 1989-1993 were reviewed. In addition a case-control study was performed to evaluate selected risk factors for this infection. Twenty-one patients had one or more blood cultures positive for P.

Effects of atenolol on rest and exercise hemodynamics in patients with mitral stenosis.

Beta-blocker therapy remains controversial in patients with mitral stenosis. In this randomized, double-blind, crossover, placebo-controlled study, the effects of atenolol (50 and 100 mg/day) were assessed in 15 patients (aged 46 +/- 11 years) with mitral stenosis (mean valve area 1.0 +/- 0.

Timing of weight gain in relation to breast cancer risk.

Excessive weight gain in women at the time of intense hormonal change can result in metabolic dysfunction. The metabolic/endocrine effect of puberty, pregnancy or menopause on breast tissue 'aging' is likely to be more relevant to a woman's breast cancer risk than is her degree of obesity at the time when the cancer presents. Experimental evidence suggests that the susceptibility of mammary tissue to carcinogenesis is greatest in early adult life, and multiple studies show that a history of weight gain in early adult life is associated with increased breast cancer risk in Western women.

Modulation of phosphoenolpyruvate carboxykinase mRNA levels by the hepatocellular hydration state.

Exposure of isolated perfused rat livers to hypo-osmotic (225 mosmol/l) perfusion media for 3 h led to a decrease of about 60% in mRNA levels for phosphoenolpyruvate carboxy-kinase (PEPCK) compared with normo-osmotic (305 mosmol/l) perfusions. Conversely, PEPCK mRNA levels increased about 3-fold during hyperosmotic (385 mosmol/l) perfusions. The anisotonicity effects were not explained by changes in the intracellular cyclic AMP (cAMP) concentration or by changes of the extracellular Na+ or Cl- activity.

Intravenous immune globulin prophylaxis of late-onset sepsis in premature neonates.

To determine whether a single dose of intravenously administered immune globulin (IVIG) decreases late-onset sepsis in premature infants, we prospectively entered 753 neonates with birth weight 500 to 2000 gm, gestation < or = 34 weeks, and age < or = 12 hours into a multicenter, double-blind, controlled trial. Infants were randomly selected to receive a single intravenous infusion, 10 ml/kg, of either IVIG (500 mg/kg) or albumin (5 mg/kg) and were observed for 8 weeks for infection. Maternal and neonatal risk factors for infection did not differ between groups.

Effects of aniso-osmolarity and hydroperoxides on intracellular pH in isolated rat hepatocytes as assessed by (2',7')-bis(carboxyethyl)-5(6)-carboxyfluorescein and fluorescein isothiocyanate-dextran fluorescence.

Freshly isolated rat hepatocytes were plated for 4-6 h and either loaded with (2',7)-bis(carboxyethyl)-5(6)-carboxyfluorescein (BCECF) or allowed to endocytose fluorescein isothiocyanate (FITC)-coupled dextran in order to study the effects of aniso-osmotic exposure and oxidative stress on cytosolic (pHcyt) and apparent vesicular pH (pHves) by single-cell fluorescence recordings. In the presence of normo-osmotic (305 mosmol/l) medium pHcyt was 7.23 +/- 0.

Effects of anisotonic exposure on duck hepatitis B virus replication.

In cultured hepatocytes from in vivo duck hepatitis B virus-infected ducks the effect of medium osmolarity on viral replication was studied. A 10-day exposure to hypotonic media (277 mOsm/L due to removal of 26 mmol/L NaCl) lowered the duck hepatitis B virus DNA content of cells and of the medium by about 50%, whereas hyperosmotic exposure (421 mOsm/L by addition of 46 mmol/L NaCl) increased it about four-fold compared with normotonic standard incubation medium (329 mOsm/L). The tissue levels of viral RNA transcripts increased during the 10 days of hypertonic exposure but decreased only slightly after hypoosmotic treatment.

Recognition and medical management of necrotizing enterocolitis.

The signs and symptoms associated with necrotizing enterocolitis (NEC) and the common scenarios in which NEC is observed are described to help physicians appreciate the breadth of this illness and to aid in the identification and diagnosis of those affected. An outline for medical management of infants with NEC is presented, based on the pathophysiology of this disease.

Epidemiology of necrotizing enterocolitis.

The descriptive epidemiology of necrotizing enterocolitis (NEC) is presented. Areas addressed include incidence, race, sex, age of onset, mortality rates, and endemic versus epidemic disease. Both descriptive and case control studies are reviewed to uncover clues relevant to the causes, pathogenesis, and prevention of NEC.

Does early physical maturity influence breast cancer risk?

Earlier onset of menarche and tallness in adult women are mainly confirmed as risk markers for breast cancer. Recent disparate case-control studies have reported abdominal-type obesity and higher circulating levels of insulin, testosterone and insulin-like growth factor 1, to be further risk markers for breast cancer. There is evidence that abdominal-type obesity is recognisable in girls even before puberty, and disparate studies have shown it to be correlated with earlier onset of menarche, insulin resistance leading to hyperinsulinaemia, and an abnormal sex steroid profile.

Effect of hepatocyte swelling on microtubule stability and tubulin mRNA levels.

Incubation of isolated rat hepatocytes under conditions known to induce cell swelling caused several alterations in microtubule physiology. As shown by immunofluorescence microscopy experiments in the absence and presence of triethyllead or colchicine (two well-established microtubule inhibitors), an apparent stabilization of the microtubule network became evident in hepatocytes exposed to hypotonic (190 mosmol/L) conditions. A similar stabilizing effect was also observed upon cell swelling induced by addition of insulin (100 nmol/L) or glutamine (10 mmol/L).

Immunoglobulin secretion by the normal and the infected newborn infant.

The development of quantitative single-cell immunoassays has provided a novel opportunity to demonstrate the isotype-specific immunoglobulin responses in normal and infected neonates. The reverse enzyme-linked immunospot assay was used to determine the number of immunoglobulin-secreting cells (IgSCs) in peripheral blood. Baseline numbers of IgSCs were established in 69 uninfected term and preterm infants within 5 days of birth; values above the 99th percentile were considered elevated.