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Biomedical subjects

D M Smith

Publications and source records attributed to D M Smith.

At least 487 records · Page 27Linked to original sources
PubMedDate not supplied

Immobilized pH gradient two-dimensional gel electrophoresis and mass spectrometric identification of cytokine-regulated proteins in ME-180 cervical carcinoma cells.

Two-dimensional (2-D) polyacrylamide gel electrophoresis combined with mass spectrometry is a powerful combination of technologies that allows high resolution separation of proteins and their rapid identification. Immobilized pH gradient (IPG) first-dimensional gels have several advantages over carrier ampholyte isoelectric focusing, including a high degree of reproducibility, good protein spot resolution, and a selection of pH range. Here we demonstrate the utility and efficacy of combining IPG 2-D gel electrophoresis with mass spectrometry to identify interferon-gamma- (IFN) and tumor necrosis factor (TNF)-regulated proteins in ME-180 cervical carcinoma cells. Three cytokine-regulated proteins have been identified, using imidazole-zinc-stained preparative IPG 2-D gels and in-gel tryptic digestion followed by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) mass spectrometry for determination of peptide masses and sequences: 1) triosephosphate isomerase, a glycolytic pathway enzyme, 2) proteasome subunit C3, which is important in protein degradation, and 3) Ran, a GTP-binding protein important in cell cycle regulation, protein import into the nucleus, and RNA export from the nucleus.

Amino Acid Sequence↗
PubMedDate not supplied

Predicting nonelective hospitalization: a model based on risk factors associated with diabetes mellitus.

Nonelective hospitalizations for urgent or emergent reasons are frequent events for patients with diabetes mellitus, and their occurrence is difficult to predict. A model for predicting nonelective hospitalizations is described. It is based on risk factors: prior visits to the emergency room, hypoalbuminemia, cardiomegaly, anemia, systolic hypotension, and hyperglycemia. To test the model, the authors conducted a prospective cohort study in which 429 ambulatory patients with diabetes mellitus were stratified into three risk levels for hospitalization and followed for two years. Patients in higher risk groups were more likely to be hospitalized (high risk, 58.1%; medium-risk, 40.2%; low risk, 26.6%, p less than 0.01) and had more hospitalizations per patient (1.47 vs. 0.80 vs. 0.46, p less than 0.01) and more hospital days per patient (14.6 vs. 8.6 vs. 5.3, p less than 0.01). When the two-year study period was divided into four six-month intervals, there was no significant difference across the four periods. This study demonstrates the validity of the model for predicting nonelective hospitalizations of patients with diabetes mellitus over time.

Ambulatory Care↗
PubMedDate not supplied

A controlled trial to increase office visits and reduce hospitalizations of diabetic patients.

An intervention package was examined to determine its effectiveness in increasing office visits and in reducing the incidence of nonelective hospitalizations (those for urgent or emergent reasons). The intervention included mailings of information, appointment reminders, and intense follow-up by telephone of visit failures for rescheduling. Eight hundred fifty-four patients receiving drug therapy for diabetes mellitus were stratified by risk of nonelective hospitalization and randomly assigned to the control group or the intervention group. After two years, the intervention group averaged 9.1 per cent more kept scheduled visits per month than the control group (0.371 vs. 0.340, p = 0.02). However, the mean incidence of nonelective hospitalizations per month was not significantly different between intervention and control groups (0.040 vs. 0.041, p = 0.9), nor was there a difference in nonelective hospital days per month (0.443 vs. 0.425, p = 0.7). The authors conclude that while mailings and telephone calls can increase office visits, the intervention is not sufficient to reduce morbidity necessitating nonelective hospitalizations of diabetic patients.

Adolescent↗
PubMedDate not supplied

Evolutionary relationships between the amphibian, avian, and mammalian stomachs.

Although the gut is homologous among different vertebrates, morphological differences exist between different species. The most obvious variation in the guts of extant vertebrates appears in the stomach. To investigate the evolution of this structure, we compared the histology of the stomach and gastrointestinal tract in amphibian (Xenopus laevis), avian (Gallus gallus), and mammalian (Mus musculus) organisms, and defined the expression patterns of several genes within the developing guts of these lineages. In all three groups, we find that the anterior portion of the stomach has a similar glandular histology as well as a common embryonic expression of the secreted factors Wnt5a and BMP-4. Likewise, within the amniote lineages, the posterior nonglandular stomach and pyloric sphincter regions are also comparable in both histological and molecular phenotypes. The posterior stomach expresses Six2, BMPR1B, and Barx1, whereas the pyloric sphincter expresses Nkx2.5. Although the adult Xenopus stomach exhibits both glandular and aglandular regions and a distinct pyloric sphincter similar to that of the amniotic vertebrates, the histology of the Xenopus tadpole gut shows less distinct variation in differentiation in this region, which is most likely a derived condition. The molecular signature of the embryonic Xenopus gut correlates with the more derived morphology of the larval phase. We conclude that the global patterning of the gut is remarkably similar among the different vertebrate lineages. The distinct compartments of gene expression that we find in the gut be necessary for the unique morphological specializations that distinguish the stomachs from terrestrial vertebrates.

Animals↗
PubMedDate not supplied

'Spin, cool, and filter' red cells prepared in a regional blood center.

Red cells depleted of leukocytes by the "spin, cool, and filter" (SCF) method are effective in preventing most febrile, nonhemolytic transfusion reactions (FNHTR). To determine whether red cell concentrates may be centrifuged in a blood center and filtered subsequently at an outlying facility, the authors examined how leukocyte removal was affected by the transport and storage of centrifuged red cells before microaggregate filtration (MAF). One hundred fourteen red cell units were each divided into two aliquots. After centrifugation, one aliquot from each unit was retained in the blood center, and the other was transported on a truck for 2 to 12 hours. Aliquots were stored for variable periods, after which the residual leukocytes were counted. Neither transportation nor storage significantly affected leukocyte removal by MAF. However, an unacceptable proportion of all SCF units failed to meet American Red Cross standards for leukocyte-poor blood and studies of factors influencing leukocyte depletion were undertaken. A relative centrifugal force of 6700 X g was needed to produce consistently acceptable units when blood was 8 to 15 days old. These results show that making SCF red cells is a practical, inexpensive way for blood centers to provide hospitals with products that prevent most FNHTR; however, each facility that prepares these products must perform quality control carefully.

Blood Banks↗
PubMedDate not supplied

Density gradient isolation of peripheral blood mononuclear cells using a blood cell processor.

Large numbers of mononuclear cells (MNC) are needed for hematologic reconstitution using peripheral blood stem cells. The possibility of isolating those cells by discontinuous Ficoll-diatrizoate density gradient centrifugation in two blood cell processors (the Haemonetics V50 [V50] and the Cobe 2991 [2991]) were examined. Buffy coats from peripheral blood containing 6.23 X 10(8) MNC were separated in the V50, resulting in a recovery of 75 percent. The purity of the cells, defined as the percentage of lymphocytes and monocytes among all leukocytes, was 95 percent. With larger cell loads (3 to 7 X 10(9) MNC), the yield was higher in the V50 than in the Cobe 2991 (92 versus 75%). After separation in the V50 or the 2991, the cloning efficiencies of hematopoietic progenitor cells (CFU-GM and BFUe) were not different from those of cells isolated on 5 ml Ficoll-diatrizoate gradients in centrifuge tubes. Both leukapheresis and MNC separation can be carried out with the same bowl and tubing set in the V50. With that approach, an average of 6 X 10(9) MNC were processed in 16 experiments. An average recovery of 82 percent with 95 percent purity was achieved. The authors conclude that, in terms of simplicity of operation, cost effectiveness, and maintenance of sterility, the V50 may be better suited than the 2991 for the purification of MNC from peripheral blood.

Cell Separation↗