Purification and characterization of human immunodeficiency virus (HIV) core precursor (p55) expressed in Saccharomyces cerevisiae.

The core structure of retroviruses, including the human immunodeficiency virus (HIV), consists of proteins that are initially synthesized as polyprotein precursors and then processed by a virally encoded protease yielding the mature core polypeptides. To obtain sufficient quantities of the purified HIV core precursor p55 for detailed studies, a segment of HIV DNA encoding the full length core precursor polyprotein p55 was expressed in Saccharomyces cerevisiae using a plasmid containing a constitutive galactose promoter. The expression of this DNA produced a protein with an estimated molecular size of 55,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE); this protein was immunoreactive to anti-HIV p24 antisera.

The effects of aging on cerebral blood flow in migraine.

We studied cerebral blood flow (CBF) with the 133xenon inhalation technique in 92 migraine patients (49 classic/complicated, 43 common), aged 19 to 85 years, in the headache-free period. We compared results to 49 control subjects, aged 22 to 80 years. CBF declined with age in both groups, but at a slower rate in migraine patients, a difference most pronounced in classic migraine.

Preliminary observations on brain energy metabolism in migraine studied by in vivo phosphorus 31 NMR spectroscopy.

We measured brain energy phosphate metabolism and intracellular pH (pHi) in a cross-sectional study of migraine patients by in vivo phosphorus 31 NMR spectroscopy. During a migraine attack the ratio ATP/total phosphate signal (mole % ATP) was preserved, but there was a decrease in mole % phosphocreatine (PCr) and an increase in mole % inorganic phosphate (Pi) resulting in a decrease of the PCr/Pi ratio, an index of brain phosphorylation potential. This was found in classic but not common migraine.

Effects of fluprazine hydrochloride on maternal behaviour in mice.

Fluprazine hydrochloride treatment disrupted both retrieval and nursing components of maternal behaviour when dam and pups were separated for a 30 min post-infection interval. Subsequent experiments revealed that pup contact during this interval, even when restricted to visual/auditory stimulation, abolished the drug's effect on nursing but not retrieval. Fluprazine appears to strongly and consistently disrupt retrieval while its effects on nursing appear more indirectly mediated.

Effects of flossing on plaque and gingivitis in third grade schoolchildren.

The purpose of this investigation was to determine whether flossing, as an adjunct to toothbrushing, performed in a school-based program can contribute significantly to a reduction in gingivitis. Four volunteer third grade classrooms (n = 112) were randomly assigned to finger-floss, looped-floss, flossholder, and brushing-only control group. Measures taken at baseline and in four weeks included gingival (GI), plaque (PI), and flossing dexterity indices (FDI).

The application of molecular biology to the development of novel vaccines.

In summary, we have shown that yeast is the preferred host for the expression of recombinant-derived hepatitis B vaccines, and that a yeast expression system which is productive, stable and scaleable can be developed for each of the three HBV envelope proteins. The versatility of regulated and integrated yeast expression systems in the production of foreign polypeptides with biomedical utility also has been highlighted. We also have shown that careful attention to the development of recombinant clones helps to optimize the entire production process leading to highly purified products which share many biochemical properties with the plasma-derived vaccine.

Risk identification at the time of admission to coronary care unit in patients with suspected myocardial infarction.

The in-hospital clinical course was evaluated in 2,162 consecutive patients admitted with a diagnosis of suspected myocardial infarction. Of these, 1609 patients were considered to be in the high-risk group, based on the presence of 16 clinical criteria present at the time of admission. The remaining 553 patients were classified as low risk.

Antigenic analysis of the Epstein-Barr virus major membrane antigen (gp350/220) expressed in yeast and mammalian cells: implications for the development of a subunit vaccine.

The Epstein-Barr virus (EBV) major surface membrane antigen, gp350/220, was expressed in recombinant yeast cells and in several recombinant mammalian cell lines. Each of the expressed proteins was analyzed for its ability to bind to a panel of anti-gp350/220 monoclonal antibodies and to a series of anti-EBV positive human sera. The antigens also were used as immunogens for the immunization of rabbits.

Free jejunal segment for treatment of cervical esophageal stricture in a dog.

A 2-year-old female Chinese Shar Pei was admitted with a 20-cm cervical esophageal stricture that was untreatable by conventional medical and surgical methods. A free jejunal segment was used to replace the strictured portion of the esophagus. Twenty-one months after surgery, the dog was able to eat liquefied canned dog food with minimal regurgitation and was maintaining normal body weight.

Platelet activity and selective beta-blockade in migraine prophylaxis.

Migraine is associated with increased platelet activity and an incidence of cerebrovascular ischemic events. Because cerebrovascular events might result from platelet aggregation, enhancing platelet activity further in the treatment of migraine is not desirable. beta-Adrenoceptor blockers effective in migraine prophylaxis include propranolol (nonselective) and metoprolol (beta 1-selective), but it is uncertain how beta-receptor subtype selectivity might influence platelet behavior in migraine.

Characterization of the human T lymphocyte adenosine receptor: comparison of normal and systemic lupus erythematosus cells.

To determine whether a defect in the T cell response to adenosine exists at the level of the adenosine receptor in systemic lupus erythematosus (SLE) we measured the binding affinity and maximum binding of T cell membranes from both normal and SLE T cells by utilizing radiolabeled adenosine ligands. Normal T lymphocyte membranes possess a single class of [3H]5-N-ethylcarboxamide adenosine binding sites with a Kd of 0.61 microM, a Bmax of 23.

Mobility of the human T lymphocyte surface molecules CD3, CD4, and CD8: regulation by a cAMP-dependent pathway.

The present study was undertaken to determine whether a cAMP pathway mediates the mobility of CD3, CD4, and CD8 within the membrane. Crosslinking CD3, CD4, and CD8 with monoclonal antibody and anti-antibody induced rapid accumulation of intracellular cAMP, occupancy of cAMP receptors, and was temporally associated with the mobilization and directed movement of these molecules to a pole of the cell. This capping process could be partially inhibited in a dose-dependent manner by treatment of T cells with 2',5'-dideoxyadenosine, a ribose-modified adenosine analogue that binds to the P site of the catalytic subunit of adenylate cyclase and reduces adenylate cyclase activity.

On estimating census undercount in small areas.

"Net undercount rates in the U.S. decennial census have been steadily declining over the last several censuses.

Eicosanoid metabolism by Leishmania donovani-infected macrophages: mouse strain responses in prostanoid synthesis.

Arachidonic acid (20:4) conversion to prostanoids was examined in murine peritoneal macrophages infected in vitro with Leishmania donovani. Four strains of mice differing in resistance to in vivo L. donovani infection were studied.

Dynamics and significance of coagulase-negative staphylococcal intramammary infections.

Cows (n = 139) were sampled within 17 d postpartum and monthly thereafter to examine dynamics of mammary infections and relationships between infection status, milk yield, SCC, NAGase activity, and chloride concentration. Forty-eight and 67% of cows and 19.5 and 30.

Efficacy of propranolol therapy after acute myocardial infarction related to coronary arterial anatomy and left ventricular function.

The effect of the beta-adrenergic blocking agent propranolol on morbidity and mortality risk after acute myocardial infarction was studied relative to coronary anatomy and left ventricular (LV) ejection fraction in a subset of 406 patients participating in a randomized study of 3,837 patients in the Beta Blocker Heart Attack Trial (BHAT). Median follow-up for this subset of patients was 28 months. The mortality rate was 2% (2 of 100) in patients with 2- and 3-vessel coronary artery disease taking propranolol and 10% (12 of 126) in those taking placebo (p less than 0.

High-dose clonidine motor syndrome: relationship to serotonin syndrome.

Reciprocal forepaw treading, hindlimb abduction, and Straub tail are some of the abnormal motor behaviors of the classical 'serotonin syndrome,' which results from activation of serotonin (5-HT) receptors. However, we also observed them in the syndrome evoked by the alpha-adrenergic agonist clonidine, at high doses (5-40 mg/kg). Other features of the clonidine syndrome (scored from videotapes) were body and head tremor, forelimb hyperextension, ataxia, vertical jumping, tactile hyperreactivity, and autonomic signs (piloerection, pupillary dilatation, salivation, proptosis).

Regional lymph node and pulmonary metastases after local hyperthermia of melanomas in C57BL/6 mice.

The effects of local tumor hyperthermia on regional lymph node metastases are inconclusive. We studied the effects of hyperthermia on the incidence of popliteal, femoral, and abdominal lymph node metastases in C57BL/6 mice with primary B16 melanomas (F10 variant) growing subcutaneously in the left foot. Tumors were heated to 42.

Cardiovascular and respiratory measurements in awake and isoflurane-anesthetized horses.

Circulatory and respiratory function was monitored in nonmedicated, spontaneously breathing horses (n = 7) immediately before, during, and 1 hour after 85 +/- 4.1 (X +/- SEM) minutes of constant 1.57% isoflurane in O2 anesthesia.

Expression and secretion in yeast of a 400-kDa envelope glycoprotein derived from Epstein-Barr virus.

The major envelope glycoprotein (gp350) of Epstein-Barr virus has been expressed and secreted in the yeast Saccharomyces cerevisiae as a 400-kDa glycoprotein. This is the first example of the secretion of such a large, heavily glycosylated heterologous protein in yeast. Since gp350 proved highly toxic to S.

Regulated overproduction of the GAL4 gene product greatly increases expression from galactose-inducible promoters on multi-copy expression vectors in yeast.

High-level, galactose-inducible expression originating from GAL promoters in Saccharomyces cerevisiae is mediated by highly specific interactions between the GAL4-coded protein and nucleotide sequences. The potential utility of recombinant GAL promoter/foreign gene constructions for the regulatable and high-level expression of foreign proteins in yeast is well recognized. However, the utility of this system is limited severely in the case of multiple copies of such constructions due to the very low level of the GAL4-coded protein and to the loss of inducibility which occurs if levels of the GAL4 protein are amplified constitutively.

Defective lymphopoiesis in bone marrow of motheaten (me/me) and viable motheaten (mev/mev) mutant mice. I. Analysis of development of prothymocytes, early B lineage cells, and terminal deoxynucleotidyl transferase-positive cells.

This study identifies defects in the early stages of lymphopoiesis that may contribute to the abnormalities in the development and/or function of peripheral T and B lymphocytes in mice homozygous for the motheaten (me/me) and viable motheaten (mev/mev) mutations. The results indicate that in me/me and mev/mev mice prothymocytes in bone marrow are present in essentially normal numbers, as determined by intrathymic injection, but apparently lack the ability to home effectively to the thymus, as determined by intravenous transfer; early B lineage cells in bone marrow, identified by the B220 antigen, are markedly depleted, including immature B cells (sIg+), pre-B cells (cIg+, sIg-), and pro-B cells (B220+, cIg-, sIg-); TdT+ bone marrow cells, especially a subset that expresses the B220 B lineage antigen, are markedly depleted by two weeks of age; normal numbers of TdT+ thymocytes are present during the first 3 wk of postnatal life, but rapidly decrease thereafter. The results further indicate that neither the defective thymus homing capacity of prothymocytes nor the deficiency of TdT+ bone marrow cells is due to autoantibodies.