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Biomedical subjects

E Davis

Publications and source records attributed to E Davis.

At least 91 records · Page 5Linked to original sources
PubMed1991

The effect of smoking and menopause on the small blood vessels.

The small blood vessels were examined in 31 premenopausal and 31 postmenopausal women. In each group there were 14 non-smokers and 17 smokers of age groups 35-45 and 45-59. The women underwent full gynecological examination. Blood pressure was normal in each. The small blood vessels were examined by capillaroscopy of conjunctivae and nailfolds, by oscillometry of the radial artery, skin thermometry of the wrist and terminal phalanx, and by capillary fragility. When all abnormalities in non-smokers were compared with those in smokers in the menopausal groups, a significant difference was found, (Table 4), to the disadvantage of the smokers.

Adult↗
PubMed1990

Detection of salivary immunoglobulin A antibodies to HIV-1 in infants and children.

Secretory immunoglobulin A (slgA) antibodies of non-maternal origin are present in newborns and slgA to HIV-1 antigens has been detected in infected adults. In this study we investigated the presence of HIV-1-specific IgA in saliva from 41 children (aged 1 day-46 months) born to women at risk for HIV-1 infection. Saliva samples were assayed for HIV-1 antibodies with IgA-specific Western blot. The samples from 10 out of 11 children with subsequently proven infection, including one aged 6 months, demonstrated IgA antibodies to HIV-1 envelope antigens. Samples from infants under 15 months, who were born to infected mothers and subsequently shown to be uninfected, were slgA negative. Of the 12 children with continued indeterminate HIV-1 status, eight showed neither slgA nor serologic evidence of infection and four showed slgA antibodies. HIV-1-specific slgA was detectable before the age of 15 months and may prove to be valuable in the diagnosis of HIV-1 infection in infants.

Child, Preschool↗
PubMed1990

Splenic thrombopoiesis after bone marrow ablation with radiostrontium: a murine model.

Murine platelet production is normally supported by high-ploidy bone marrow megakaryocytes without significant contribution from splenic megakaryocytes with predominantly low-ploidy levels. We produced sustained bone marrow ablation using radiostrontium, and examined the processes by which splenic platelet production is initiated and maintained in the absence of bone marrow function. Bone marrow hematopoiesis, measured by total nucleated cell number and viability, megakaryocyte colony-forming cells, and granulocyte-macrophage colony-forming cells, was rapidly ablated in mice by using yttrium 90-free strontium 90. Platelet count declined from normal (1224 x 10(3)/microliters) to a nadir (98 x 10(3)/microliters) 11 days after 90Sr, and then rose to a stable level (705 x 10(3)/microliters) on days 20 through 115. Peripheral leukocyte concentration decreased rapidly and remained below 25% of normal in contrast to hemoglobin levels, which were minimally lowered. Mean spleen weight rose rapidly after 90Sr to 66% above normal. Splenic megakaryocyte frequency, measured by two-color fluorescence-activated flow cytometry, rose from basal levels (0.09% +/- 0.06%) to 0.15% +/- 0.07% (p less than 0.001), total spleen nucleated cells fell to 71% of normal, and the absolute number of spleen megakaryocytes was unchanged. Total spleen megakaryocyte colony-forming cells were not significantly increased above normal whereas total spleen granulocyte-macrophage colony-forming cells increased abruptly after day 13 to 10 times normal levels. Splenectomy after hematopoietic recovery from 90Sr bone marrow ablation resulted in a rapid decline of platelet levels, followed by death. Although the spleen became the sole site of platelet production, the splenic megakaryocyte ploidy distribution was only minimally changed from normal, and the modal ploidy class remained 2N. In contrast to experimental thrombocytopenia in mice with intact bone marrow, in which megakaryocyte ploidy is increased, thrombocytopenia associated with sustained bone marrow ablation does not result in upward regulation of splenic megakaryocyte ploidy as a compensatory mechanism.

Animals↗
PubMed1989

Emergency department sonography by emergency physicians.

A retrospective study was conducted to examine whether emergency physicians can perform accurate ultrasonography that influences the diagnosis and treatment of selected disorders in the emergency department (ED). The physicians acquired a moderate level of expertise in sonography using a series of practical demonstrations and lectures. Patients with symptoms suggestive of cardiac, gynecologic, biliary tract, and abdominal vascular disease periodically underwent ED sonography. The initial interpretation was used as a diagnostic adjunct to subsequent therapy. The accuracy of positive sonographic findings was assessed by confirmatory testing, formal review, or confirmatory clinical course. Emergency physicians were able to diagnose correctly (1) the presence and approximate size of pericardial effusions, (2) the presence or absence of organized cardiac activity in patient with clinical electrical mechanical dissociation, (3) the presence or absence of intrauterine pregnancy in pregnant patients with lower abdominal/pelvic complaints, (4) the position of intrauterine devices in patients with suspected uterine perforation, (5) the presence of gallstones in patients with suspected biliary tract disease, and (6) the presence and size of abdominal aortic aneurysms in patients with pulsatile masses or unexplained abdominal pain. It was concluded that reliable sonography which influences diagnosis and therapy can be performed by emergency physicians and that sonography should become a standard procedure in EDs.

Aorta, Abdominal↗
PubMed1989

Analysis of transcription initiation in the Panolis flammea nuclear polyhedrosis virus polyhedrin gene.

The nucleotide sequence of the polyhedrin gene of Panolis flammea multiple nucleocapsid polyhedrosis virus (PfMNPV) has been determined. The coding sequences of this gene shared 82% similarity at the DNA level and 88% similarity at the protein level with the polyhedrin gene from Autographa californica (Ac) MNPV. A single nucleotide deviation from the consensus transcription initiation sequence for baculovirus very late genes was identified in the PfMNPV polyhedrin gene. RNA was prepared from Mamestra brassicae larvae infected with PfMNPV and compared with RNA harvested at 24 h post-infection from AcMNPV-infected Spodoptera frugiperda cells using Northern blotting with an AcMNPV polyhedrin gene-specific probe. The PfMNPV mRNA was estimated to be 1.0 kb compared with a larger size of 1.15 kb for the AcMNPV polyhedrin mRNA. A cDNA copy of the 5' end of the PfMNPV polyhedrin mRNA was made using the technique of primer extension and sequenced to demonstrate that the point of transcription initiation was similar to that of AcMNPV polyhedrin mRNA.

Animals↗
PubMed1988

Presurgical prediction of postsurgical visual acuity in patients with media opacities.

Of the estimated 1 million patients each year in the United States who undergo surgery for media opacities, perhaps 5-10% fail to improve because of pre-existing, undiagnosed retinal and/or optic nerve disease. In this paper, the standard presurgical evaluation (case history, visual acuity, refraction, pupillary response testing, biomicroscopy, ophthalmoscopy, tonometry, visual fields and color vision) and the supplementary presurgical evaluation (entoptic phenomena appreciation, ophthalmic ultrasonography, fluorescein angiography, laser interferometry, potential acuity meter, visual evoked potential, electroretinography, contrast sensitivity and hyperacuity measurements) are reviewed.

Cataract↗
PubMed1987

Characterization of c-Ki-ras oncogene alleles by direct sequencing of enzymatically amplified DNA from carcinogen-induced tumors.

Activated c-Ki-ras genes in liver tumors from rats exposed to the potent hepatocarcinogen aflatoxin B1 were analyzed to determine the nature of their activation by characterization of two c-Ki-ras alleles present in tumor-derived NIH 3T3 mouse transformants. Using selective hybridization of synthetic oligonucleotides to transformant DNA, we have determined that a single G X C to A X T base transition in either the first or second position of the 12th codon is associated with activation of the gene. Such mutations would lead to amino acid substitutions of aspartate or serine for glycine in the mutant proteins. To confirm these findings, we applied a technique for direct sequence analysis of a 90-base-pair region of the rat c-Ki-ras gene produced by primer-directed enzymatic amplification. Findings produced by this approach, which provides a convenient method to characterize mutations in multiple alleles without the necessity to clone individual genes, confirmed the presence and identity of the 12th codon mutations in the activated oncogene, as initially determined by the oligonucleotide hybridization technique.

Aflatoxin B1↗
PubMed1986

Nursing management of the patient with total en bloc resection of the temporal bone.

En bloc resection of the temporal bone is an extensive and complicated surgical procedure for removal of malignancies of the ear and temporal bone. The lengthy surgical procedure (18 to 36 hours) and the resultant functional disabilities and cosmetic deformities create special nursing management concerns. Preoperative preparation, carotid artery occlusion, and postoperative nursing management are discussed. Communication and psychological issues for the patient and family are presented.

Combined Modality Therapy↗
PubMed1985

Endocrine profile of pregnancy in the patas monkey (Erythrocebus patas).

Spontaneous toxemia occurs in approximately 6% of pregnancies in patas monkeys (Erythrocebus patas). To assess further the relevance of this animal as a model system for toxemia of pregnancy in humans, we characterized the endocrine profile of the patas pregnancy by analyzing weekly blood samples for estrone, estradiol, estriol, progesterone, aldosterone, and PRA throughout gestation. The profiles obtained bear striking resemblance to those described for human pregnancy, an unexpected finding since the patas monkey is not a higher hominoid. We conclude that the patas monkey may provide a model of toxemia relevant to study of the human disorder and is superior to other animal models which require surgical manipulation and are characterized by secondary hyperreninemia.

Aldosterone↗
PubMed1985

Deletion of the proximal long arm of chromosome 3 in an infant with features of Turner syndrome.

A case of deletion of the proximal one-fourth of chromosome 3 long arm is described. While the Turner syndrome phenotype was present neonatally, the patient has no structural or numerical abnormality of the sex chromosomes, and thus may represent an autosomal deletion with a clinical picture similar to Turner syndrome. Her score on the Noonan syndrome index of Duncan et al. (1981) is 27%, making Noonan syndrome unlikely.

Child↗
PubMed1983

Urinary 3-methylhistidine excretion in man: the role of protein-bound and soluble 3-methylhistidine.

The influence of dietary meat and meat stock intake on urinary excretion of 3-methylhistidine (3MH) was examined in human adults. In the absence of 3MH ingestion for 48 h, the study subjects adjusted to an intrinsic urinary 3MH: creatinine value. If the meat and meat stock-free diet was maintained on subsequent days, only minute diurnal variations occurred, and the values of random urine samples during the day were representative of the 24 h 3MH: creatinine value. The mean 3MH: creatinine value (SD) for a group of adults (n 7) was 0.105 +/- 0.023 (mumol of 3MH/mg creatinine), which is approximately 35% lower than the corresponding value in healthy growing infants (0.148 +/- 0.039) (Seashore et al. 1981). Ingestion of meat soup and meat causes different patterns of urinary excretion of 3MH which are consistent with the finding that meat extracts, such as soup and stock, contain considerable amounts of 3MH. The 3MH contents of beef, chicken and turkey were 3.8 +/- 0.15, 3.0 +/- 0.09 and 2.3 +/- 0.29 mumol/g dry wt meat respectively. All three meats contained a water-soluble 3MH-fraction (% total 3MH: beef 8, chicken 21, turkey 23). Amino acid analysis of the soluble fraction with or without hydrochloric acid hydrolysis demonstrated free 3MH in chicken and turkey (5.2 and 2.8% of the total respectively) but not in beef. Patients undergoing urinary 3MH measurements should maintain a diet that is free not only of solid meats, but also of meat stock. The ingestion of commercial food products (e.g. frozen or canned meals, sauces, pizza, etc.) may impair the validity of such measurements because of their meat-stock content. A dietary regimen is presented which is based on a shorter 12 h urine collection. The shorter collection time is satisfactory in the light of the steady rate of 3MH-excretion after 2 d of a diet free of meat and meat stock.

Adult↗
PubMed1982

Urinary 3-methylhistidine excretion in juvenile-onset diabetics: evidence of increased protein catabolism in the absence of ketoacidosis.

Urinary 3-methylhistidine excretion (an indicator of protein catabolism) was measured in ten diabetic patients and in age and weight matched control subjects. The diabetic group, while receiving their usual insulin dose, excreted 42% more 3-methylhistidine than the control group (2.7 versus 1.9 mumole/kg body weight/24 hr). When the insulin dose of the diabetic subject was reduced by 15% or 25%, the concentrations of blood and urinary glucose were significantly increased by the rate of urinary 3-methylhistidine excretion was not increased further. These findings demonstrate augmented protein catabolism in diabetics even in the absence of ketoacidosis. It appears that blood and urine glucose levels are more sensitive to changes in insulin availability than protein catabolism.

Adult↗