Threat to U.S. mouse colonies.
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Animals↗
Biomedical subjects
S Perkins
Publications and source records attributed to S Perkins.
Proliferation, C-myc, and cyclin D1 expression in diffuse alveolar damage: potential roles in pathogenesis and implications for prognosis.
In this study we compared expression of DNA topoisomerase IIalpha, a marker of cellular proliferation, c-myc, and cyclin D1 in lung biopsy specimens showing diffuse alveolar damage (DAD) with control lung tissues. We subsequently correlated DNA topoisomerase IIalpha, c-myc, and cyclin D1 expression with survival. We hypothesized that poor outcome may correlate with a higher proliferation index, and that c-myc and cyclin D1 activation are potentially important regulators of both proliferation and apoptosis in DAD. Immnuohistochemical stains for c-myc, cyclin D1, and DNA topoisomerase IIalpha were performed on 10 cases of DAD (15 cases for DNA topoisomerase IIalpha) and 10 control lungs. A proliferation index for each case was calculated by dividing the number of nuclei expressing DNA topoisomerase IIalpha by the total number of nuclei counted. The percentages of alveolar pneumocytes and interstitial cells staining positively for c-myc and cyclin D1 were estimated. The average proliferation index (DNA topoisomerase IIalpha index) in DAD (0.16 +/- 0.06, n = 15) was significantly greater than in control lungs (0.00 +/- 0.01, n = 10) (P < .0001). The average proliferation index of patients with DAD who died of respiratory failure (0.18 +/- 0.05, n = 9) was significantly greater than the average proliferation index of patients whose respiratory disease resolved or stabilized (0.11 +/- 0.05, n = 5) (P < .03). Expression of c-myc in alveolar pneumocytes and interstitial cells was more intense and slightly more widespread in cases of DAD compared with control lungs. In 9 of 10 cases of DAD, cyclin D1 expression was present in up to 30% of alveolar pneumocytes and up to 10% of interstitial cells. No staining for cyclin D1 was present in control lungs. These results show that the proliferation index in DAD potentially correlates with patient survival. Furthermore, enhanced expression of c-myc and cyclin D1 may contribute to dysregulation of cellular proliferation and apoptosis observed in DAD.
Adolescent↗
Serum progesterone in predicting pregnancy outcome after assisted reproductive technology.
PURPOSE: Our purpose was to determine whether serum progesterone predicts pregnancy outcome after superovulation. METHODS: One hundred twenty-three consecutively pregnant patients were divided into three groups: group I, 55 patients following superovulation for assisted reproductive technologies; group II, 23 patients after correction of oligoovulation; and group III, 45 patients who conceived spontaneously. When beta-human chorionic gonadotropin was positive, progesterone was measured on the same serum sample. A serum progesterone level of 45 microns/L was set to differentiate between nonviable pregnancy and ongoing pregnancy. RESULTS: In group I, zero (0%) of 38 ongoing pregnancies and 10 (59%) of 17 nonviable pregnancies were observed with a progesterone level of < 45 microns/L [14.2 ng/ml (P < 0.001)]. In group II, 4 (27%) of 15 ongoing pregnancies and 5 (63%) of 8 nonviable pregnancies had a progesterone level of < 45 microns/L (P = NS). In group III, 10 (42%) of 24 ongoing pregnancies and 15 (71%) of 21 nonviable pregnancies were observed with a progesterone level of < 45 microns/L (14.2 ng/ml) (P = NS). CONCLUSIONS: A serum progesterone level of < 45 nM predicts nonviable pregnancy after superovulation for assisted reproductive technology.
Chorionic Gonadotropin↗
Immunomagnetic recovery of human neutrophil defensins from the human gingival crevice.
The human neutrophilic protein defensins are cationic, antimicrobial, cytotoxic, corticostatic chemotactic, opsonic peptides found in azurophilic granules and constitute about 5% of the total protein in human neutrophils. In the present study, defensins were recovered from the human gingival crevice using paramagnetic microspheres (beads), coated with anti-defensin antibodies. The bead-bound defensins were assayed using an enzyme-linked immunosorbent assay developed in this laboratory. Twenty sites were sampled; defensin was found in 100% of the sites and ranged in amount from 270-2000 ng/site. The large local concentrations of defensins, estimated in the mg/ml range, may have major effects on the microbiology of the gingival crevice.
Adult↗
Crystallization of ClfA and ClfB fragments: the fibrinogen-binding surface proteins of Staphylococcus aureus.
Recombinant constructs encoding the fibrinogen-binding domains of ClfA and ClfB from Staphylococcus aureus have been crystallized. ClfA was crystallized in the orthorhombic space group P212121 with unit-cell parameters a = 39.58, b = 81.39 and c = 112.65 A. A complete data set was recorded to 2.1 A resolution and had a Vm of 2. 3 A3 Da-1 with 46.5% solvent, suggesting one molecule per asymmetric unit. Co-crystals of ClfA with the 17 amino-acid C-terminal peptide of fibrinogen gamma-chain diffracted to 2.1 A resolution and had unit-cell parameters a = 39.11, b = 81.39 and c = 109.51 A in the space group P212121. ClfB was crystallized in the tetragonal space group P41212 or P43212 with unit-cell parameters a = 96.31, b = 96. 31 and c = 84.13 A and diffracted to 2.45 A resolution. The estimated Vm of 2.6 A3 Da-1 with 53% solvent indicated one molecule in the asymmetric unit.
Amino Acid Sequence↗
Mousepox: a threat to mouse colonies.
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Animals↗
Mousepox: a threat to U.S. mouse colonies.
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Animals↗
Determination of primary amino acid sequence and unique three-dimensional structure of WGH1, a monoclonal human IgM antibody with anti-PR3 specificity.
Transformed B cells making monoclonal IgM-lambda anti-PR3 antibody WGH1 from a patient with Wegener's granulomatosis were used to prepare mRNA and synthesize cDNA. PCR primers for human micro and lambda chains were then employed to amplify heavy- and light-chain V-regions followed by cloning into pCR2-1 vector and sequencing. Molecular modeling of VH regions employed knowledge-based homology modeling to obtain minimum energy conformation. The VH sequence was subgroup III with marked overall homology to VH1.9III. The VHCDR3 region of WGH1 was unique, consisting of 21 amino acid residues which included seven tyrosines as well as three negatively charged aspartic acid residues. The VL region was subgroup II with a negatively charged glutamic acid at position 100 in CDR3. Molecular modeling of VH revealed a major conformational difference in the shape of CDR3 compared with other antibodies for which three-dimensional structures have been determined. Monoclonal antibody WGH1 reacting with PR3 (a highly positively charged molecule) shows a unique reactive cassette within VHCDR3 with a number of negatively charged aspartic acid residues. WGH1 VHCDR3 contains a loop which shows a major projection not usually recorded in other previously studied antibody molecules.
Amino Acid Sequence↗
Bcl-2 and bax protein expression in indolent versus aggressive B-cell non-Hodgkin's lymphomas.
Bcl-2 and bax are cellular proteins that are important in the regulation of apoptosis. Overexpression of bcl-2 protein is associated with prolonged cell survival, whereas overexpression of bax correlates with increased apoptosis after injury. It has been suggested that the ratio of bcl-2 and bax determines a cell's susceptibility to apoptosis. We studied bcl-2 and bax expression by immunohistochemical methods in 46 cases of B-cel non-Hodgkin's lymphoma characterized by the Revised European-American Lymphoma (REAL) classification to determine whether expression of these two proteins correlated with the histological subtype or the predicted clinical behavior (indolent v aggressive). For each case, both the percentage of cells staining as well as the intensity of staining of bcl-2 and bax were recorded, and a bcl-2-bax protein ratio (BBPR) was calculated. Bax staining was identified in 100% of the lymphomas studied. In contrast, bcl-2 staining was seen in only 67%. Bcl-2 expression correlated with the subtype of lymphoma with positive staining in 100% of small lymphocytic lymphomas, 80% of follicle center lymphomas, 38% of diffuse large cell lymphomas, 33% of high-grade B-cell Burkitt's-like lymphomas, 0% of Burkitt's lymphomas, and 0% of B-cell lymphoblastic lymphomas. The BBPR of indolent lymphomas (mean, 1.8) was significantly greater than the BBPR of aggressive lymphomas (mean, 0.6) (P < or = .002). This suggests that bax and bcl-2 expression may be linked to biological behavior in non-Hodgkin's B-cell lymphomas.
Humans↗
Clumping factor B (ClfB), a new surface-located fibrinogen-binding adhesin of Staphylococcus aureus.
The surface-located fibrinogen-binding protein (clumping factor; ClfA) of Staphylococcus aureus has an unusual dipeptide repeat linking the ligand binding domain to the wall-anchored region. Southern blotting experiments revealed several other loci in the S. aureus Newman genome that hybridized to a probe comprising DNA encoding the dipeptide repeat. One of these loci is analysed here. It also encodes a fibrinogen-binding protein, which we have called ClfB. The overall organization of ClfB is very similar to that of ClfA, and the proteins have considerable sequence identity in the signal sequence and wall attachment domains. However, the A regions are only 26% identical. Recombinant biotinylated ClfB protein bound to fibrinogen in Western ligand blots. ClfB reacted with the alpha- and beta-chains of fibrinogen in the ligand blots in contrast to ClfA, which binds exclusively to the gamma-chain. Analysis of proteins released from the cell wall of S. aureus Newman by Western immunoblotting using antibody raised against the recombinant A region of ClfB identified a 124 kDa protein as the clfB gene product. This protein was detectable only on cells that were grown to the early exponential phase. It was absent from cells from late exponential phase or stationary phase cultures. Using a clfB mutant isolated by allelic replacement alone and in combination with a clfA mutation, the ClfB protein was shown to promote (i) clumping of exponential-phase cells in a solution of fibrinogen, (ii) adherence of exponential-phase bacteria to immobilized fibrinogen in vitro, and (iii) bacterial adherence to ex vivo human haemodialysis tubing, suggesting that it could contribute to the pathogenicity of biomaterial-related infections. However, in wild-type exponential-phase S. aureus Newman cultures, ClfB activity was masked by the ClfA protein, and it did not contribute at all to interactions of cells from stationary-phase cultures with fibrinogen. ClfB-dependent bacterial adherence to immobilized fibrinogen was inhibited by millimolar concentrations of Ca2+ and Mn2+, which indicates that, like ClfA, ligand binding by ClfB is regulated by a low-affinity inhibitory cation binding site.
Adhesins, Bacterial↗
Dexamethasone promotes expression of membrane-bound macrophage colony-stimulating factor in murine osteoblast-like cells.
The mechanisms by which glucocorticosteroids promote osteoclastogenesis in vitro are uncertain. As macrophage colony-stimulating factor (MCSF) is critical for osteoclastogenesis, we hypothesized that glucocorticosteroids might regulate membrane-bound MCSF (mMCSF) and soluble MCSF (sMCSF) production by stromal cells or osteoblasts. ST2 cells or murine calvarial osteoblasts (MOBs) were treated with dexamethasone (Dex; 100 nM) and/or 1,25-dihydroxyvitamin D [1,25(OH)2D; 10 nM] for 3 days. Control values for mMCSF and sMCSF as units per 100,000 cells were 9 +/- 1.4 and 511 +/- 56 in ST2 cells and 5.9 +/- 0.8 and 379 +/- 47 in MOB cells, respectively. Dex increased mMCSF to 156 +/- 16% and 143 +/- 26% compared with the control value in ST2 and MOB cells, respectively, whereas 1,25-(OH)2D caused increases of 195 +/- 16% and 164 +/- 21%. In the presence of both Dex and 1,25-(OH)2D, mMCSF increased to 209 +/- 24% and 216 +/- 26% in the two cell types, respectively. 1,25-(OH)2D caused modest increases in sMCSF, as expected, in both cell types (153 +/- 6% and 122 +/- 4%). Dex inhibited 1,25-(OH)2D-stimulated sMCSF (115 +/- 7% of control) in ST2 cells. Analysis of mMCSF transcript levels by semiquantitative RT-PCR revealed Dex-stimulated increases of 170 +/- 11% in ST2 cells and 126 +/- 16% in MOB cells compared with the control level. The increased expression of the transcript for sMCSF in the presence of Dex and 1,25-(OH)2D, measured by both RT-PCR and Northern analysis (219 +/- 53% and 242%, respectively), despite inhibition of sMCSF protein, indicated that the inhibitory effect of Dex in ST2 cells was posttranscriptional. Half-life studies showed that Dex prolonged MCSF messenger RNA from 2.8 to 7.5 h. These results suggest that Dex influences osteoclastogenesis by increasing the expression of mMCSF by accessory cells in culture.
Animals↗
A randomized controlled trial of strict glycemic control and tertiary level obstetric care versus routine obstetric care in the management of gestational diabetes: a pilot study.
OBJECTIVES: The purpose of this study was to determine whether strict maternal glycemic control for the treatment of gestational diabetes lessened the risk of fetal macrosomia, birth trauma, neonatal hypoglycemia, and operative delivery. The aim of the pilot study was to prepare for a multicenter trial by assessing patient acceptance of the study, by determining realistic accrual rates, and by detecting any major adverse outcomes in the control group that received routine obstetric care. STUDY DESIGN: The study was a prospective randomized controlled trial comparing fetal-neonatal and maternal outcomes in 300 women with gestational diabetes. Women randomized to the treatment arm were managed by strict glycemic control and tertiary level obstetric care, and women in the control arm received routine obstetric care. RESULTS: Three hundred women with gestational diabetes mellitus were studied. There was no difference in maternal age, weight, or length of gestation between groups. The treatment mean birth weight was 3437 +/- 575 gm compared with 3544 +/- 601 gm in the control group, a difference of 107 gm (not significant). Macrosomia rates were similar. There was no birth trauma in either group. The frequency of neonatal hypoglycemia and other metabolic complications was the same. The mode of delivery also showed similar patterns. The treatment group had significantly lower preprandial and postprandial glucose levels by 32 weeks' gestation, which continued to term. CONCLUSION: This pilot study suggests that intensive treatment of gestational diabetes mellitus may have little effect on birth weight, birth trauma, operative delivery, or neonatal metabolic disorders. It has demonstrated the safety of proceeding to a multicenter trial of sufficient sample size to confirm these findings.
Adult↗
An STS-based radiation hybrid map of the human genome.
We have constructed a physical map of the human genome by using a panel of 83 whole genome radiation hybrids (the Stanford G3 panel) in conjunction with 10,478 sequence-tagged sites (STSs) derived from random genomic DNA sequences, previously mapped genetic markers, and expressed sequences. Of these STSs, 5049 are framework markers that fall into 1766 high-confidence bins. An additional 945 STSs are indistinguishable in their map location from one or more of the framework markers. These 5994 mapped STSs have an average spacing of 500 kb. An additional 4484 STSs are positioned with respect to the framework markers. Comparison of the orders of markers on this map with orders derived from independent meiotic and YAC STS-content maps indicates that the error rate in defining high-confidence bins is < 5%. Analysis of 322 random cDNAs indicates that the map covers the vast majority of the human genome. This STS-based radiation hybrid map of the human genome brings us one step closer to the goal of a physical map containing 30,000 unique ordered landmarks with an average marker spacing of 100 kb.
Animals↗
Neutralizing human monoclonal antibodies to conformational epitopes of human T-cell lymphotropic virus type 1 and 2 gp46.
Ten human monoclonal antibodies derived from peripheral B cells of a patient with human T-cell lymphotropic virus (HTLV)-associated myelopathy are described. One monoclonal antibody recognized a linear epitope within the carboxy-terminal 43 amino acids of HTLV gp21, and two monoclonal antibodies recognized linear epitopes within HTLV type 1 (HTLV-1) gp46. The remaining seven monoclonal antibodies recognized denaturation-sensitive epitopes within HTLV-1 gp46 that were expressed on the surfaces of infected cells. Two of these antibodies also bound to viable HTLV-2 infected cells and immunoprecipitated HTLV-2 gp46. Virus neutralization was determined by syncytium inhibition assays. Eight monoclonal antibodies, including all seven that recognized denaturation-sensitive epitopes within HTLV-1 gp46, possessed significant virus neutralization activity. By competitive inhibition analysis it was determined that these antibodies recognized at least four distinct conformational epitopes within HTLV-1 gp46. These findings indicate the importance of conformational epitopes within HTLV-1 gp46 in mediating a neutralizing antibody response to HTLV infection.
Antibodies, Monoclonal↗
Cytotoxic effects of MPTP on SH-SY5Y human neuroblastoma cells.
Morphological and metabolic endpoints were used to evaluate MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) toxicity to SH-SY5Y human neuroblastoma cells. After 8 hours of exposure, MPTP was found to affect cell viability only at a very high concentration (3 x 10(-3) M), but its metabolite MPP+ could decrease viability at 10(-4) M. MPTP, via its metabolite MPP+, inhibited NADH dehydrogenase activity when concentrations exceeded 10(-4) M (for MPP+ 10(-5)M). The Ki were 2.4 x 10(-3) M and 3 x 10(-4)M for MPTP and MPP+, respectively. MPTP at concentrations greater than 10(-4) M altered cell morphology as early as one hour after exposure. These changes included formation of cell surface blebs and attenuated neurites. After 8 hours at 10(-3) M and 24 hrs at 10(-4) M, MPTP caused ultrastructural changes of mitochondria with increased electron-density of the matrix and disorganization of cristae, as well as abnormal aggregation of filamentous material of the cytoskeleton. Because these changes of structure and function took place at concentrations lower than those needed to affect cell viability, they may play a role in MPTP neurotoxicity in SH-SY5Y cell culture.
1-Methyl-4-phenylpyridinium↗
Single-agent paclitaxel in advanced non-small cell lung cancer: single-center phase II study using a 3-hour administration schedule.
The efficacy and safety of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) administered as a 3-hour infusion was investigated in a phase II study involving 21 patients with stage III/IV non-small cell lung cancer. The study included two quality of life assessments (the Hospital Anxiety and Depression Scale and the Rotterdam Symptom Checklist) to test their suitability for use in a future randomized phase III trial of paclitaxel and best supportive care versus best supportive care alone. Four (19%) of the 21 patients (95% confidence interval, 8% to 38%) achieved a partial response. The median time to disease progression for all patients entered was 19 weeks. Paclitaxel was well tolerated, with dose reduction required in only one patient because of arthralgia/myalgia. No dose reductions, delays, or discontinuations were required for hematologic toxicity. Completion and compliance with quality of life questionnaires was high, and these research tools proved to be acceptable for future use in phase III studies with paclitaxel.
Adult↗
The power of E-mail takes author's voice across the globe.
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Computer Communication Networks↗
A gene map of the human genome.
The human genome is thought to harbor 50,000 to 100,000 genes, of which about half have been sampled to date in the form of expressed sequence tags. An international consortium was organized to develop and map gene-based sequence tagged site markers on a set of two radiation hybrid panels and a yeast artificial chromosome library. More than 16,000 human genes have been mapped relative to a framework map that contains about 1000 polymorphic genetic markers. The gene map unifies the existing genetic and physical maps with the nucleotide and protein sequence databases in a fashion that should speed the discovery of genes underlying inherited human disease. The integrated resource is available through a site on the World Wide Web at http://www.ncbi.nlm.nih.gov/SCIENCE96/.
Amino Acid Sequence↗