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Biomedical subjects

J Brown

Publications and source records attributed to J Brown.

At least 289 records · Page 16Linked to original sources
PubMed1999

The Tripler LE3AN Program: a two-year follow-up report.

This paper provides a review of 2-year follow-up data on the Tripler Army Medical Center LE3AN Program. The LE3AN Program (emphasizing healthy Lifestyles, reasonable Exercise, realistic Expectations, Emotions, and Attitudes, and Nutrition) provides active duty service members a treatment strategy that involves a reasonable low-intensity exercise regimen, behavior modification, intensive nutritional counseling healthy meal planing, relapse prevention strategies, cognitive coping strategies, and healthy lifestyle principals to lose weight and maintain weight loss. Based on the 2-year data and additional clinical findings, we expand upon earlier preliminary reports. The 2-year follow-up data suggest that the program is a safe and efficacious treatment program.

Adult↗
PubMed1999

Characteristics of families who attend free vaccine fairs.

OBJECTIVE: To determine the health care resources and perceived barriers to care of families attending free vaccine fairs. DESIGN: A cross-sectional survey. SETTING: Twelve free vaccine fairs in Denver, Colorado, in 1994. PARTICIPANTS: A total of 533 consecutive parents or guardians of children receiving vaccine at the fairs. Interventions. None. MEASUREMENTS/RESULTS: Survey respondents reported that their children received regular health care through a private physician or health maintenance organization (HMO) (47%), a public clinic (20%), or a hospital-based clinic (14%); 18% had no regular site for health care. Twenty-seven percent of the families carried private insurance, although less than half of these plans covered children's vaccines: 9% were enrolled in an HMO or a preferred provider organization and 13% had Medicaid, whereas 50% had no health insurance. Families who received primary care at a private physician's office (OR: 1.7; 95% CI: 1.01-2.7) and those with no regular site for health care (OR: 2.0; 95% CI: 1.01-4.0) were more likely than those who went to a public clinic or hospital clinic to report free vaccine as the most important reason for attending a vaccine fair. Conversely, families who received well-child care at a hospital clinic were more likely to identify no appointment needed as the most important reason (OR: 2.7; 95% CI: 1. 4-5.1). Families with private health insurance (OR: 2.3; 95% CI: 1. 05-4.0) or no health insurance (OR: 2.3; 95% CI: 1.1-4.6) were more likely to identify free vaccine as the most important reason for attending a vaccine fair, whereas those enrolled in an HMO or preferred provider organization identified convenient time as the most important reason (OR: 3.2; 95% CI: 1.2-8.3). Families with Medicaid (OR: 3.2; 95% CI: 1.3-8.3) or with no insurance (OR: 2.1; 95% CI: 1.02-4.6) were more likely than were those with private insurance to identify no appointment needed as the most important reason for attending a vaccine fair. CONCLUSIONS: Most families attending free vaccine fairs have a regular source of health care. For families with private health insurance or with no health insurance, the availability of free vaccine is the major reason to bring their children to a vaccine fair, whereas for families whose insurance routinely covers the cost of childhood vaccine (HMO, Medicaid), convenience is the major determinant.

Colorado↗
PubMed1999

Effects of acidosis on leptin secretion from 3T3-L1 adipocytes and on serum leptin in the uraemic rat.

Marked hyperleptinaemia and metabolic acidosis are common findings in patients with chronic renal failure. In animal models, both leptin administration and acidosis reduce food intake. However, leptin causes loss of body fat, while acidosis induces muscle wasting. Whether a low pH and leptin production are related has not been studied. Leptin secretion was measured in cultured 3T3-L1 adipocytes exposed to acid or control pH for up to 96 h. In addition, serum leptin was compared between acidotic and bicarbonate-treated uraemic Wistar rats using the remnant model. Leptin levels in the culture medium were decreased at an acid pH of 7.1 compared with a control pH of 7.5 at 96 h (562+/-78 and 831+/-103 pg.48 h(-1). well(-1) respectively; mean+/-S.E.M.; P=0.037). Similarly, serum leptin in uraemic rats was found to be lower in the acidotic group than in the bicarbonate-treated group, although this observation fell just short of statistical significance (1273+/-171 compared with 2059+/-376 pg/ml; P=0.07). In conclusion, acidosis decreases leptin secretion from cultured adipocytes. Accordingly, acidotic uraemic rats seem to exhibit lower serum leptin levels than their bicarbonate-supplemented counterparts. This study is the first report providing a link between acidosis and leptin levels.

3T3 Cells↗
PubMed1999

Knowledge and use of the food label among senior women in the management of type 2 diabetes mellitus.

Food selection is a key component in the management of diabetes. The foods selected affect the caloric and nutrient composition of the diet and blood glucose levels among people with diabetes. The nutrition information on the food label can guide decisions for food purchases. Whether senior women with diabetes use and comprehend the nutrition information on the food label has not been determined. Therefore, the purpose of this study was to assess knowledge and beliefs about the food label and diabetes management among women with type 2 diabetes mellitus =65 years of age. Focus groups were conducted and participants (n=24) completed a knowledge test about the food label. Analysis involved extensive review of the videotapes and transcripts of the focus groups. Participants reported that they referred to the nutrition information on the label when grocery shopping. Yet, comprehension of terms and product claims on the label was poor. The mean score on the food label knowledge test was only 49%. Misconceptions about the nutritional management of diabetes also were noted. Thus, senior women with diabetes need additional education about the food label to facilitate application of the information in meal planning and to manage diabetes successfully.

Aged↗
PubMed1999

Cryomyolysis in the management of uterine fibroids: technique and complications.

Uterine fibroids are common benign tumors of the uterus and a major public health problem. Between 20 and 25% of women over 35 years of age are estimated to have fibroids. Three subtypes of fibroids are recognized depending on their relationship to the myometrium, namely, submucosal, subserosal and intramural. Fibroids are frequently asymptomatic, but may be associated with menorrhagia, dysmenorrhea, pregnancy loss or infertility. They are composed predominantly of smooth muscle, with a variable amount of connective tissue, and they have a characteristic smooth white whorled appearance on cross sectional examination.

Journal Article↗
PubMed1998

The CGRP receptor can couple via pertussis toxin sensitive and insensitive G proteins.

Swiss 3T3 cell lines were constructed co-expressing receptor activity modifying protein (RAMP) 1 with the calcitonin receptor-like receptor (CRLR), and showed 125I-calcitonin-gene-related peptide (CGRP) 1 binding indicative of a type I CGRP receptor. Application of CGRP1 led to an increase in cAMP, which in 2/5 cell lines was augmented following pertussis toxin (PTX) pre-treatment. In Xenopus oocytes, expression of RAMP1, which potentiates an endogenous CGRP receptor, led to constitutive activation of co-expressed GIRK potassium channels. This potassium current was increased following CGRP application or co-expression of CRLR, but decreased by PTX or co-expression of transducin. We conclude that the CGRP receptor can signal to both PTX sensitive and insensitive G proteins.

3T3 Cells↗
PubMed1998

Molecular cytogenetic characterization of a critical region in bands 7q35-q36 commonly deleted in malignant myeloid disorders.

Loss of chromosome 7 (-7) or deletion of the long arm (7q-) are recurring chromosome abnormalities in myeloid leukemias. The association of -7/7q- with myeloid leukemia suggests that these regions contain novel tumor suppressor gene(s), whose loss of function contribute to leukemic transformation or tumor progression. Based on chromosome banding analysis, two critical regions have been identified, one in band q22 and another in bands q32-q35. Presently there are no data available on the molecular delineation of the distal critical region. In this study we analyzed bone marrow and blood samples from 13 patients with myeloid leukemia (de novo myelodysplastic syndrome [MDS], n = 3; de novo acute myeloid leukemia [AML], n = 9; therapy-related (t-) AML, n = 1) which, on chromosome banding analysis, exhibited deletions (n = 12) or in one case a balanced translocation involving bands 7q31-qter using fluorescence in situ hybridization (FISH). As probes we used representative clones from a contig map of yeast artificial chromosome (YAC) clones that spans chromosome bands 7q31.1-qter. In the 12 cases with loss of 7q material, we identified a commonly deleted region of approximately 4 to 5 megabasepairs in size encompassing the distal part of 7q35 and the proximal part of 7q36. Furthermore, the breakpoint of the reciprocal translocation from the patient with t-AML was localized to a 1,300-kb sized YAC clone that maps to the proximal boundary of the commonly deleted region. Interestingly, in this case both homologs of chromosome 7 were affected: one was lost (-7) and the second exhibited the t(7q35). The identification and delineation of translocation and deletion breakpoints provides the first step toward the identification of the gene(s) involved in the pathogenesis of 7q35-q36 aberrations in myeloid disorders.

Chromosome Mapping↗
PubMed1998

Stromal expression of Jagged 1 promotes colony formation by fetal hematopoietic progenitor cells.

The Notch signaling system regulates proliferation and differentiation in many tissues. Notch is a transmembrane receptor activated by ligands expressed on adjacent cells. Hematopoietic stem cells and early progenitors express Notch, making the stromal cells which form cell-cell contacts with progenitor cells candidate ligand-presenting cells in the hematopoietic microenvironment. Therefore, we examined primary stromal cell cultures for expression of Notch ligands. Using reverse transcription-polymerase chain reaction, in situ hybridization, immunohistochemistry, and Western blotting, we demonstrate expression of Jagged 1 in primary stromal cultures. To investigate if the stromal expression of Jagged 1 has functional effects on hematopoietic progenitors, we cultured CD34(+), c-kit+ hematopoietic progenitor cells derived from the aorto gonadal mesonephros region of day 11 mouse embryos on the Jagged 1(-) stromal cell line S17 and on S17 cells engineered to express Jagged 1. The presence of Jagged 1 increased the number of colonies formed in subsequent methylcellulose culture fourfold. Larger increases in colony numbers were observed under the same culture conditions with CD34(+), c-kit+ hematopoietic progenitor cells derived from d11 fetal liver. These results obtained in vitro table Jagged 1 as a candidate regulator of stem cell fate in the context of stromal microenvironments in vivo.

Animals↗
PubMed1998

An update on dental imaging.

This paper reviews recent advances and current trends in dental radiology. Developments in the design of dental x-ray equipment which improve both radiation hygiene and image quality are described. Also discussed are new features which broaden the scope of intra-oral and panoramic radiological diagnosis in the general dental practice setting. The article concludes with the main recommendations from the latest guidelines on quality standards for radiography, selection criteria and quality assurance in general practice.

Equipment Design↗
PubMed1998

Determination of the conformations of cAMP receptor protein and its T127L,S128A mutant with and without cAMP from small angle neutron scattering measurements.

Small angle neutron scattering (SANS) measurements were performed on solutions of cAMP receptor protein (CRP) and on solutions of the T127L,S128A double mutant of CRP (CRP*) in D2O K3PO4 buffer containing 0.5 M KCl, in the absence and presence of 3',5' cyclic adenosine monophosphate (cAMP). Energy-minimized structures of the CRP were calculated by minimization of the x-ray crystallographic structure of CRP in either the exclusively "closed" form where the alpha-helices of the carboxyl-terminal domain are folded close to the amino-terminal domain and in the exclusively "open" form where the alpha-helices of the carboxyl-terminal domain are folded away from the amino-terminal domain. Neutron scattering models show that the CRP SANS data follow closely the data curve predicted for unligated CRP in the open form, whereas the cAMP-ligated data are more in agreement with the data predicted for the minimized cAMP-ligated CRP structure in the closed form. Thus, it appears that CRP undergoes a conformational change from the open form to the closed form in solution upon ligation with cAMP. The SANS data from the CRP* and cAMP-ligated CRP* are coincidental, which implies that there is very little structural difference between the two species of CRP*. This is in agreement with in vivo results, which show that whereas CRP activates transcription in the cell only in the presence of cAMP, CRP* activates transcription in the absence of cAMP, implying that CRP* is already in the correct conformation for the activation of transcription.

Crystallography, X-Ray↗
PubMed1998

RAMPs regulate the transport and ligand specificity of the calcitonin-receptor-like receptor.

Calcitonin-gene-related peptide (CGRP) and adrenomedullin are related peptides with distinct pharmacological profiles. Here we show that a receptor with seven transmembrane domains, the calcitonin-receptor-like receptor (CRLR), can function as either a CGRP receptor or an adrenomedullin receptor, depending on which members of a new family of single-transmembrane-domain proteins, which we have called receptor-activity-modifying proteins or RAMPs, are expressed. RAMPs are required to transport CRLR to the plasma membrane. RAMP1 presents the receptor at the cell surface as a mature glycoprotein and a CGRP receptor. RAMP2-transported receptors are core-glycosylated and are adrenomedullin receptors.

3T3 Cells↗
PubMed1998

Stage specificity, dose response, and doubling dose for mouse minisatellite germ-line mutation induced by acute radiation.

Germ-line mutation induction at mouse minisatellite loci by acute irradiation with x-rays was studied at premeiotic and postmeiotic stages of spermatogenesis. An elevated paternal mutation rate was found after irradiation of premeiotic spermatogonia and stem cells, whereas the frequency of minisatellite mutation after postmeiotic irradiation of spermatids was similar to that in control litters. In contrast, paternal irradiation did not affect the maternal mutation rate. A linear dose-response curve for paternal mutation induced at premeiotic stages was found, with a doubling dose of 0.33 Gy, a value close to those obtained in mice after acute spermatogonia irradiation using other systems for mutation detection. High frequencies of spontaneous and induced mutations at minisatellite loci allow mutation induction to be evaluated at low doses of exposure in very small population samples, which currently makes minisatellite DNA the most powerful tool for monitoring radiation-induced germ-line mutation.

Animals↗
PubMed1998

Rho-mediated contractility exposes a cryptic site in fibronectin and induces fibronectin matrix assembly.

Many factors influence the assembly of fibronectin into an insoluble fibrillar extracellular matrix. Previous work demonstrated that one component in serum that promotes the assembly of fibronectin is lysophosphatidic acid (Zhang, Q., W.J. Checovich, D.M. Peters, R.M. Albrecht, and D.F. Mosher. 1994. J. Cell Biol. 127:1447-1459). Here we show that C3 transferase, an inhibitor of the low molecular weight GTP-binding protein Rho, blocks the binding of fibronectin and the 70-kD NH2-terminal fibronectin fragment to cells and blocks the assembly of fibronectin into matrix induced by serum or lysophosphatidic acid. Microinjection of recombinant, constitutively active Rho into quiescent Swiss 3T3 cells promotes fibronectin matrix assembly by the injected cells. Investigating the mechanism by which Rho promotes fibronectin polymerization, we have used C3 to determine whether integrin activation is involved. Under conditions where C3 decreases fibronectin assembly we have only detected small changes in the state of integrin activation. However, several inhibitors of cellular contractility, that differ in their mode of action, inhibit cell binding of fibronectin and the 70-kD NH2-terminal fibronectin fragment, decrease fibronectin incorporation into the deoxycholate insoluble matrix, and prevent fibronectin's assembly into fibrils on the cell surface. Because Rho stimulates contractility, these results suggest that Rho-mediated contractility promotes assembly of fibronectin into a fibrillar matrix. One mechanism by which contractility could enhance fibronectin assembly is by tension exposing cryptic self-assembly sites within fibronectin that is being stretched. Exploring this possibility, we have found a monoclonal antibody, L8, that stains fibronectin matrices differentially depending on the state of cell contractility. L8 was previously shown to inhibit fibronectin matrix assembly (Chernousov, M.A., A.I. Faerman, M.G. Frid, O.Y. Printseva, and V.E. Koteliansky. 1987. FEBS (Fed. Eur. Biochem. Soc.) Lett. 217:124-128). When it is used to stain normal cultures that are developing tension, it reveals a matrix indistinguishable from that revealed by polyclonal anti-fibronectin antibodies. However, the staining of fibronectin matrices by L8 is reduced relative to the polyclonal antibody when the contractility of cells is inhibited by C3. We have investigated the consequences of mechanically stretching fibronectin in the absence of cells. Applying a 30-35% stretch to immobilized fibronectin induced binding of soluble fibronectin, 70-kD fibronectin fragment, and L8 monoclonal antibody. Together, these results provide evidence that self-assembly sites within fibronectin are exposed by tension.

3T3 Cells↗