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Biomedical subjects

S A Miller

Publications and source records attributed to S A Miller.

At least 145 records · Page 8Linked to original sources
PubMed1985

Scientific and public health rationale for the Dietary Guidelines for Americans.

The Dietary Guidelines for Americans, published by DHHS and USDA in 1980, have recently been reviewed by an expert committee that has recommended only minimal changes to scientifically update them. Initial efforts to develop dietary guidelines for prevention of diseases were fraught with controversy, some of which has continued. This controversy exemplifies a larger issue concerning the role that contemporary science, and specifically government, has in assuring and maintaining public health. Two broad questions need to be asked: what is the government's role in facilitating application of contemporary nutrition knowledge to public health, and what standard of scientific surety should be the basis for its application? Government's role in assuring public health and safety indirectly through information is well established. In deciding when the data are sufficient to inform the public, public health scientists must, at some point, make the leap of faith, even though some doubts may remain.

Agriculture↗
PubMed1985

Pulmonary macrophage function during experimental cytomegalovirus interstitial pneumonia.

Since cytomegalovirus (CMV) infections may alter host defense against a variety of pathogens, phagocytosis, oxygen uptake, and H2O2 release by pulmonary macrophages obtained from guinea pigs with acute CMV interstitial pneumonia were evaluated. Experimental animals were inoculated subcutaneously on day zero with 10(7.5) 50% tissue culture infective doses of virulent guinea pig CMV. Control animals received an uninfected salivary gland suspension. The animals were sacrificed on day 7; the tissues were cocultivated for virus isolation, and the lungs were lavaged to obtain pulmonary macrophages. CMV was isolated from buffy coat cells (96%), bone marrow cells (71%), whole lungs (77%), pulmonary macrophages (60%), and pulmonary granulocytes (49%). There was no significant difference between groups at sacrifice in the total number of macrophages obtained by pulmonary lavage or in the phagocytic activity of the macrophages in vitro. However, in CMV-infected animals, the maximum rates of O2 consumption in response to the soluble stimulus, phorbol myristate acetate, and the particulate stimulus, Staphylococcus aureus, were 47 and 55%, respectively, of the rates in uninfected controls. Total macrophage O2 consumption in CMV-infected animals was 32 and 37%, respectively, of control values in response to the same stimuli. In CMV-infected animals, the maximum rates of H2O2 release were 22% of those in simultaneous controls for both stimuli, and total H2O2 release was 30 and 25%, respectively, of that in controls in response to these stimuli. Such alterations in macrophage oxidative function may contribute to superinfection during CMV pneumonia.

Acute Disease↗
PubMed1985

Protection of respiration of a crude mitochondrial preparation in cerebral ischaemia by control of blood glucose.

There is evidence that systemic hyperglycaemia influences the evolution of cerebral ischaemia adversely, through enhancement of brain lactic acidosis. A potential protective regimen based on induction of mild hypoglycaemia with insulin was therefore studied. Respiratory control in brain mitochondria prepared from the ischaemic hemisphere of rats subjected to unilateral common carotid artery occlusion for one hour was abolished, but was partially preserved in insulin-treated rats (p = 0.01).

Animals↗
PubMed1985

The effects of hyperglycaemia on changes during reperfusion following focal cerebral ischaemia in the cat.

The effects of isosmolar loads of glucose and saline after onset of focal cerebral ischaemia (middle cerebral artery occlusion) were compared in cats. In cats given saline cerebral blood flow (CBF) fell and then rose slightly on the marginal gyrus (infarct penumbra). There was a sustained fall in CBF on the suprasylvian and ectosylvian gyri (infarct core). Reperfusion restored blood flow to preocclusion levels with no overall postischaemic hypoperfusion. Below ischaemic flows of 14 ml/100 g/min brain specific gravity was reduced in a smaller proportion of gyri by contrast with non reperfused cortex, suggesting that in some gyri resolution of cerebral oedema had taken place. GABA uptake was normal in the infarct core, but was reduced within the ischaemic penumbra. In animals given glucose after occlusion, CBF fell on the marginal gyrus during reperfusion. The degree of resolution of cerebral oedema was less than in saline infused cats. GABA uptake showed a pattern of abnormality similar to that seen in saline infused cats, except that uptake values were lower in the infarct core. Pial surface potassium activity remained elevated in the penumbra following reperfusion in glucose infused cats, but returned to normal in saline infused cats. Implications for the management of cerebral ischaemia in man are discussed.

Animals↗
PubMed1985

Cancer, diet, and public policy.

The response of Government to the relationship between diet and chronic disease is a legitimate public health policy issue, yet the proper role of Government is a subject of continuing debate. Regulatory mechanisms designed to address questions of food additives or contaminants in food are ill-suited to address questions of diet/disease relationships because of the different standards and types of evidence involved. In this paper we examine, through the use of several examples, the question of whether current evidence on the relationship of diet to cancer is sufficient to make changes in public health policy. Finally, we discuss potential Governmental approaches, both short- and long-term, to implementing policy in the area of diet and cancer.

Diet↗
PubMed1985

Does bacteremia occur during flexible sigmoidoscopy?

Up to 10% of patients may have bacteremia after rigid sigmoidoscopy. The aim of our study was to determine the frequency of bacteremia accompanying flexible sigmoidoscopy. Blood samples for aerobic and anaerobic cultures were obtained before, during, and after flexible sigmoidoscopy in 100 patients who were examined a mean distance of 49.5 cm, range 15-60 cm, after a bowel preparation of two Fleet enemas. In one patient, a transient bacteremia with Streptococcus intermedius was documented and was attended by no associated clinical manifestations. This organism has been previously isolated from patients with endocarditis, peritonitis, emphysema, and hepatic and appendiceal abscesses. There was no association in our study with bacteremia and such factors as length of bowel examined and duration of procedure, the presence of bowel pathology, performance of endoscopic biopsies, liver disease, and portal hypertension or poor bowel preparation. We conclude that the extremely low incidence of significant bacteremia with flexible sigmoidoscopy may be related to the smaller diameter of the instrument and provides further support for the routine use of flexible rather than rigid sigmoidoscopy.

Adult↗
PubMed1984

A kinetic model for the action of the enzyme activated irreversible inhibitor 4-amino-5-hexynoic acid in vivo.

The extent of inactivation of three aminotransferases by the enzyme activated inhibitor 4-amino-hex-5-ynoate (acetylenic-GABA) increased with increasing dose in an exponential fashion. Theoretical treatment of the data allowed an estimate of the effective concentration of the drug at its site of action to be made and it was apparent that any rises in substrate concentration produced by the inactivation did not protect the enzyme significantly. Altered diet produced distinct changes in the extent of inactivation of aspartate aminotransferase, but not with ornithine aminotransferase. Cysteine sulphinate, a substrate only of aspartate aminotransferase, also affected the inactivation of ornithine aminotransferase, suggesting that secondary metabolic effects were responsible.

4-Aminobutyrate Transaminase↗
PubMed1984

Vaccination against transplacental cytomegalovirus transmission: vaccine reactivation and efficacy in guinea pigs.

The guinea-pig model of cytomegalovirus (CMV) infection was used in continuing studies of experimental CMV vaccines for prevention of congenital CMV infection. Low-passage guinea-pig cytomegalovirus (GPCMV) vaccine, which has been shown to be effective in preventing transplacental CMV transmission, was tested for reactivation during pregnancy. In Hartley strain guinea pigs intraperitoneally given 10(5.5) 50% tissue culture infective doses (TCID50) of low-passage vaccine, 27 (41%) of 66 throat swabs obtained during subsequent pregnancies showed CMV, in contrast to 28 (24%) of 115 throat swabs obtained from nonpregnant control animals. High-passage GPCMV vaccine (approximately 5 X 10(3) TCID50) did not cause acute viremia, detectable generalized infection, or GPCMV reactivation during subsequent pregnancies. Immune pregnant animals and their fetuses were protected against generalized CMV infection when challenged with virulent GPCMV. In contrast, nonimmune pregnant controls developed generalized maternal, placental, and fetal infection. Experimental low-dose, high-passage GPCMV vaccine can protect against transplacental CMV transmission without apparent vaccine reactivation during pregnancy.

Animals↗
PubMed1984

Distribution of alpha 1-antitrypsin variants in a US white population.

A white population from the State of Minnesota of primarily German and Scandinavian heritage was subtyped for alpha 1-antitrypsin variants using isoelectric focusing. The frequencies of the genes PI*M1 (0.724), PI*M2 (0.137) and PI*M3 (0.095) were consistent with those for white populations documented in the literature from Northern Europe. Other genes identified in the study were PI*F, PI*I, PI*P, PI*S and PI*Z.

Gene Frequency↗
PubMed1983

A point prevalence of otitis media in a Nigerian village.

One hundred seventy children and 103 adults from a rural Nigerian village were examined for the presence of middle and external ear pathology. Ear, nose and throat examination included: (1) pneumatic otoscopic exam, (2) tympanometry and (3) contralateral acoustic reflex. A diagnostic algorithm was applied to these 3 findings for each subject and each ear. Our data showed a point prevalence of otitis media in children (less than or equal to 15 years) to be 21.2% compared to 4% in adults (greater than 15 years). Of the 36 children with otitis media, only 3 had perforation and otorrhea; a diagnosis of otitis media with effusion behind an intact tympanic membrane was made in the other 33 children. The prevalence of otitis media varied significantly with age and evidence of upper respiratory tract infection. There was no significant difference between sexes. External ear pathology was found as an independent variable in 24% of the 170 children; three-fourths of these children had concurrent middle ear pathology. The results are discussed in relation to the current understanding of the differences that exist in the epidemiology and pathogenesis of otitis media in different racial groups.

Acoustic Impedance Tests↗
PubMed1983

Fetal sex determined by ultrasound.

In an ultrasonographic laboratory we scanned 545 consecutive obstetric patients for obstetric indications based on the consultative needs of the physicians involved in their care. We attempted to determine the sex on all fetuses. The gestational age ranged from 15 weeks to term. Fetal sex was established in 196 (36%). After the 25th week of gestation, we predicted the sex in greater than 50%. There were no errors in the entire series. The basis of sex determination was the demonstration of male and female genitalia.

Female↗