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Biomedical subjects

S Baker

Publications and source records attributed to S Baker.

At least 217 records · Page 12Linked to original sources
PubMed1977

Malignant transformation and mutagenesis in mammalian cells induced by vicinal diol-epoxides derived from benzo(a)pyrene.

Benzo[a] pyrene and the syn- and anti-isomers of the 7,8-diol 9,10-oxide and of the 9,10-diol 7,8-oxide derived from this hydrocarbon have been tested for their abilities to induce malignant transformation in M2 mouse fibroblasts and mutagenesis in V79 Chinese hamster cells. The anti-isomer of the 7,8-diol 9,10-oxide induced more mutations and transformation than did the other three vicinal diol-epoxides. The two 9,10-diol 7,8-oxides were moderately mutagenic but did not induce any transformation. In contrast, benzo[a]-pyrene induced transformation in M2 fibroblasts but was not mutagenic in the V79 cells.

Animals↗
PubMed1977

The T gamma chain of human fetal hemoglobin at birth and in several abnormal hematologic conditions.

The T gamma chain of human fetal hemoglobin has a threonyl in stead of an isoleucyl residue in position 75. When the cord bloods from infants from varied ethnic backgrouds and geographic areas were tested for the presence of the T gamma chain, it was present in 28 or 98 samples. In some groups as many as 40% had the T gamma chain whereas none was detected in other. When the T gamma chain was present, its quantity was about 20% of the total gamma chains, but one case had 35%. Among beta-thalassemia homozygotes of the Mediterranean region, 70% and the T gamma chain in the amount of 20-50% of the total gamma chains, but seven Black beta-thalassemia homozygotes were negative for the T gamma chain. The fetal hemoglobin of 16 adult patients with sickle cell anemia had no T gamma chains, but 2 of 9 newborn children with sickle cell anemia had the T gamma chain. The frequency of the T gamma gene (16), the relationship of the T gamma gene to the G gamma and A gamma genes, and the significance of the T gamma gene are discussed.

Adult↗
PubMed1976

Mucosal recovery in treated childhood celiac disease (gluten-sensitive enteropathy).

Follow-up studies on 36 children, in whom celiac disease (gluten-sensitive enteropathy) was established by gluten challenge, were carried out after management on gluten-free diets for a mean of six years. Evaluations included measurement of height and weight, which for the group approximated normal distributions, and histologic examination of the duodenal or jejunal mucosa. Mucosal morphology was regarded as normal in 16, and there were minimal changes in 20. Epithelial cell height was within the normal range in all the children. Interepithelial lymphocytes were within normal range in the majority and lymphoid cells in the lamina propria were not different from those in control subjects. Mucosal lactase was significantly lower in patients than in control subjects in the duodenum and the jejunum, whereas sucrase and alkaline phosphatase values were significantly lower in the jejunum but not in the duodenum. Low content of mucosal lactase and increased numbers of interepithelial lymphocytes may be sensitive indicators of persisting ingestion of gluten in mucosa that is otherwise normal or approximately so in appearance.

Adolescent↗
PubMedDate not supplied

Phenobarbital pharmacokinetics and bioavailability in adults.

The pharmacokinetics and bioavailability of phenobarbital were examined in six healthy adult subjects after a 2.6 mg/kg intravenous and a 2.9 mg/kg oral dose. Serum concentrations of phenobarbital were followed by means of a high pressure liquid chromatographic assay for 21 days after drug administration. After the intravenous dose, the mean distribution half-life was 0.18 hour and the mean elimination half-life was 5.8 days. Mean total body clearance and mean renal clearance were 3.0 ml/hr/kg and 0.8 ml/hr/kg, respectively. The apparent volume of distribution was 0.60 liter/kg. After administration of phenobarbital tablets, the maximum phenobarbital serum concentration was 5.5 mg/liter at 2.3 hours after the dose. Adjusted absolute availability of phenobarbital from the tablets studied was 94.9 per cent (range 81-111.9 per cent). The elimination half-life averaged 5.1 days for the oral dose. There was no evidence of autoinduction of phenobarbital elimination over the study period.

Adult↗
PubMedDate not supplied

Amniotic fluid calcium concentration in the prenatal diagnosis of cystic fibrosis.

Calcium concentrations were measured in supernatant amniotic fluid in order to establish whether they may be used as a marker for cystic fibrosis. No difference in values were found, whether the sample was derived from a normal pregnancy or from a pregnancy which resulted in a baby affected with cystic fibrosis.

Amniotic Fluid↗
PubMedDate not supplied

Clinical criteria for the detection of pneumonia in adults: guidelines for ordering chest roentgenograms in the emergency department.

Adults presenting to an emergency department with acute respiratory illness were studied prospectively in an effort to identify sensitive clinical criteria for the diagnosis of pneumonia. Of 308 patients studied, 118 (38%) had definite or equivocal infiltrates and were considered to have pneumonia. No single symptom or sign was reliably predictive of pneumonia. Cough was the most common symptom in patients with pneumonia (86%), but was equally common in those with other respiratory illness. Fever was absent in 36 patients with pneumonia (31%). Abnormal findings on lung examination, that is, rales, rhonchi, decreased breath sounds, wheezes, altered fremitus, egophony, and percussion dullness, were each found in fewer than half of the patients with pneumonia. Twenty-six patients (22%) with a completely normal chest examination had pneumonia. Abnormal vital signs (temperature greater than 37.8 degrees C (100 degrees F), pulse greater than 100/min, or respirations greater than 20/min) were 97% sensitive for the detection of pneumonia. These criteria retained their sensitivity when films were subjected to a second, blinded interpretation by a senior radiologist. We conclude that restricting chest roentgenograms to patients with at least one abnormal vital sign will detect almost all radiographically demonstrable pneumonia in adult emergency department patients.

Adolescent↗
PubMedDate not supplied

Disposition of 14C-eptifibatide after intravenous administration to healthy men.

Eptifibatide, a synthetic peptide inhibitor of the platelet glycoprotein IIb/IIIa receptor, has been studied as an antithrombotic agent in a variety of acute ischemic coronary syndromes. The purpose of the present study was to characterize the disposition of 14C-eptifibatide in man after a single intravenous (i.v.) bolus dose. 14C-Eptifibatide (approximately 50 microCi) was administered to eight healthy men as a single 135-microgram/kg i.v. bolus. Blood, breath carbon dioxide, urine, and fecal samples were collected for up to 72 hours postdose and analyzed for radioactivity by liquid scintillation spectrometry. Plasma and urine samples were also assayed by liquid chromatography with mass spectrometry for eptifibatide and deamidated eptifibatide (DE). Mean (+/- SD) peak plasma eptifibatide concentrations of 879 +/- 251 ng/mL were achieved at the first sampling time (5 minutes), and concentrations then generally declined biexponentially, with a mean distribution half-life of 5 +/- 2.5 minutes and a mean terminal elimination half-life of 1.13 +/- 0.17 hours. Plasma eptifibatide concentrations and radioactivity declined in parallel, with most of the radioactivity (82.4%) attributed to eptifibatide. A total of approximately 73% of administered radioactivity was recovered in the 72-hour period following 14C-eptifibatide dosing. The primary route of elimination was urinary (98% of the total recovered radioactivity), whereas fecal (1.5%) and breath (0.8%) excretion was small. Eptifibatide is cleared by both renal and nonrenal mechanisms, with renal clearance accounting for approximately 40% of total body clearance. Within the first 24 hours, the drug is primarily excreted in the urine as unmodified eptifibatide (34%), DE (19%), and more polar metabolites (13%).

Adult↗
PubMedDate not supplied

Parental understanding of basic infant nutrition: misinformed feeding choices.

To assess mothers' knowledge of good infant nutritional practices, a survey was conducted by the Institute of Pediatric Nutrition. The survey addressed issues related to breast-feeding, the use of iron-fortified formula, frequent spitting up, the introduction of cow's milk into the infant diet, and the nutritional value of fruit juice. Mothers who responded to the survey had difficulty identifying the most appropriate choices. This article presents the survey results and discusses the implications for health care providers who care for children and their families.

Adult↗
PubMedDate not supplied

HIV/AIDS, nurses, and the black church: a case study.

Historically, the Black church has participated by lending support, providing care, and being actively involved in the health and social welfare of its members. However, since the epidemic impact of HIV/AIDS in the Black community, the church has been sharply criticized for its lukewarm response and involvement. Nurses are in a unique position to participate in educating the Black community about HIV/AIDS through the church. This article provides an insight into the response by the Black church to the disease and the potential role of nurses in faith communities, and offers recommendations for planning an HIV/AIDS program and a list of helpful resources.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Evidence for the lack of mismatch-repair directed antirecombination during mouse meiosis.

Meiotic recombination was studied in DNA mismatch repair (MMR)-deficient mice using a strain carrying a Pms2 knockout mutation. Using single-sperm typing, recombination was analyzed over five intervals on four chromosomes in four Pms2 -/- animals. A total of 1936 meioses were studied and compared to 1848 meioses from three Pms2 +/+ controls. A smaller study was carried out on a single interval in each of two chromosomes in an MMR-deficient mouse homozygous for the Msh2 knockout mutation. A total of 792 meioses were examined in the Msh2 -/- and 880 meioses in the Msh2 +/+ animal. Recombination fractions were not significantly different in either of the MMR-deficient mouse strains when compared to MMR-proficient controls. Our results appear to conflict with mouse embryonic stem (ES) cell gene-targeting experiments where MMR plays a major role in determining the efficiency of homologous recombination between nonidentical sequences. A number of possibilities could explain the apparent lack of a significant effect on meiosis.

Adenosine Triphosphatases↗
PubMedDate not supplied

Prevalence of incidental paranasal sinuses opacification in pediatric patients: a CT study.

A prospective evaluation of the paranasal sinuses was performed on a consecutive series of 137 pediatric patients referred for cranial CT. Approximately one-half of the patients less than 13 years of age had some degree of maxillary or ethmoid sinus opacification. The prevalence and severity of opacification was approximately the same for the maxillary and ethmoid sinuses. Sphenoid sinus abnormality was less common (16% of patients) and was usually minimal or mild. No incidental frontal sinus abnormalities were observed. This study confirms previous reports, based on plain film radiography, of the prevalence of incidental maxillary sinus opacification in children. However, contrary to some prior studies, we did not find a relatively higher rate of opacification in children less than 1 year of age. This may be due to overdiagnosis of maxillary sinus opacification on plain films, in small children. The diagnosis of sinusitis in childhood must take into account not only the radiographic findings but clinical signs and symptoms. Correlation is needed to avoid overdiagnosis in patients referred for sinus radiography for nonspecific indications or who have incidental opacification noted on radiographic or CT studies of the skull and brain.

Adolescent↗
PubMedDate not supplied

Plasma lipoprotein distribution of apolipoprotein E in familial hypercholesterolemia.

Although familial hypercholesterolemia (FH) has been well characterized in terms of the etiology of the major lipoprotein abnormality, that of low density lipoproteins (LDL), less information is available on changes in other lipoproteins which could influence the atherogenic process in this disorder. The present study has focused on such potential abnormalities by studying in detail the lipoprotein association of apolipoprotein E (apo E) in a large group of subjects homozygous for FH. Total plasma apo E levels in homozygous subjects were significantly elevated (p less than 0.001) relative to heterozygous subjects which were, in turn, significantly greater (p less than 0.001) than controls (137.6 micrograms/ml, 69.4 micrograms/ml, 46.5 micrograms/ml respectively). After separation of plasma lipoproteins by 4% agarose chromatography, an increased mass of apo E in lipoproteins of intermediate size was present; this may reflect the absence of LDL receptors that normally mediate their clearance. Homozygous FH subjects also demonstrated an increased mass of apo E-enriched high density lipoproteins (HDL) of large size, but a reduction in HDL cholesterol and apo A-I. The increase in the potentially atherogenic remnant lipoproteins and the decrease in HDL are associated with an increased risk for atherosclerosis, even in the absence of the LDL elevation, which is characteristic of FH. The increase in apo E-enriched HDL could reflect a compensatory mechanism that permits reverse cholesterol transport in the absence of LDL receptors.

Apolipoprotein C-III↗
PubMedDate not supplied

The use of modular nutrients in pediatrics.

BACKGROUND: Nutrient modules are commonly used by pediatricians and dietitians. There is no readily available current literature to which those using nutrient modules can refer. Therefore, we review nutrient module composition, module use in pediatrics, and complications associated with the use of nutrient modules. METHODS: Using an online database, Meduline, we searched the literature from 1996 through 1995. RESULTS: Nutrient modules are single or multiple nutrients that can be combined with a diet to add nutrients or to change the composition of the diet. These nutrients exist as a food or as medically compounded elements of a diet but alone are not complete foods. DISCUSSION: The addition of modules to a diet can alter the composition of a diet so that a single nutrient may become deficient and the diet cannot support normal growth and development. With use of nutrient modules, diets can be prepared to meet the specific needs of children with common or rare nutritional problems. CONCLUSION: Health care providers who use nutrient modules must understand the importance of diet composition and the careful monitoring of pediatric patients.

Child↗
PubMedDate not supplied

Leadership through interdisciplinary teams: a case study of an acute pain service.

Interdisciplinary teams are rapidly becoming the standard for the organization and delivery of acute care services. Increasingly, research is showing that an interdisciplinary approach has the potential to improve patient care. Implementing a team approach, however, has challenges because of the various perspectives that different disciplines bring. In this paper we present a case study of an Acute Pain Service to illustrate how an interdisciplinary team can work to improve pain management in hospitals. The development of the Acute Pain Service will be described along with a discussion of the challenges that were faced. Key lessons will be presented that may lend direction for the implementation of an Acute Pain Service or for any other interdisciplinary team.

Acute Disease↗