Multimerization potential of the cytoplasmic domain of the human immunodeficiency virus type 1 transmembrane glycoprotein gp41.

We previously demonstrated that an envelope mutant of human immunodeficiency virus type 1 lacking the entire cytoplasmic domain interferes in trans with the production of infectious virus by inclusion of the mutant envelope into the wild-type envelope complex. We also showed that the envelope incorporation into virions is not affected when the wild-type envelope is coexpressed with the mutant envelope. These results suggest that an oligomeric structure of the cytoplasmic domain is functionally required for viral infectivity.

Coupling of osteopontin and its cell surface receptor CD44 to the cell survival response elicited by interleukin-3 or granulocyte-macrophage colony-stimulating factor.

The receptors for interleukin-3 (IL-3) and granulocyte-macrophage colony-stimulating factor (GM-CSF) share a common beta subunit, the distal cytoplasmic domain of which is essential for the promotion of cell survival by these two cytokines. Genes whose expression is specifically induced by signaling through the distal cytoplasmic domain of this receptor beta subunit were screened by a subtraction cloning approach in derivatives of a mouse pro-B-cell line. One gene thus identified was shown to encode a protein highly homologous (with only 7 amino acid substitutions) to murine osteopontin (OPN), a secreted adhesion protein.

Active detachment of Streptococcus mutans cells adhered to epon-hydroxylapatite surfaces coated with salivary proteins in vitro.

Although the formation of biofilms has been much studied, detachment of adherent cells from biofilms has been relatively neglected. Recent results have shown that adherent Streptococcus mutans cells can actively detach from epon-hydroxylapatite (EHA) rods conditioned with hog gastric mucin. The mechanisms for adherence and detachment of Strep.

Evaluation of linkage of markers on chromosome 6p with schizophrenia in Taiwanese families.

Previous studies have indicated possible linkage of schizophrenia with chromosome 6p21-24. In an attempt to replicate these findings, we studied the linkage of schizophrenia with nine markers on chromosome 6p21-24 in 39 Taiwanese schizophrenic nuclear families with at least two affected siblings. Two diagnostic models (narrow: Diagnostic and Statistical Manual of Mental Disorders-IV schizophrenia only; and broad: including schizophrenia, schizoaffective, and other nonaffective psychotic disorders) were used to define the disease phenotypes.

Antibacterial activities of extracts from Nigerian chewing sticks.

Ten aqueous extracts from wooden chewing sticks widely used in Nigeria for teeth cleaning were studied for antibacterial activities against 25 different bacteria using an agar diffusion assay. The extracts from five sticks, namely Garcinia kola, Anogeissus leiocarpus, Terminalia glaucescens, Sorindeia warneckei and Vitex doniana, exhibited strong activities against a wide spectrum of bacteria including medically and dentally relevant bacteria. Notably, these five chewing stick extracts showed potent activities against methicillin-resistant Staphylococcus aureus, vancomycin-resistant Enterococcus, and multidrug-resistant Burkholderia cepacia and Pseudomonas aeruginosa.

Isolation and characterization of an anti-HSV polysaccharide from Prunella vulgaris.

A water soluble substance was isolated from a Chinese herb, Prunella vulgaris, by hot water extraction, ethanol precipitation and gel permeation column chromatography. Chemical tests showed that the substance was an anionic polysaccharide. Using a plaque reduction assay, the polysaccharide at 100 microg/ml was active against the herpes simplex virus types 1 and 2 (HSV-1 and HSV-2), but was inactive against cytomegalovirus, the human influenza virus types A and B, the poliovirus type 1 or the vesicular stomatitis virus.

Cytokine receptor common beta chain as a potential activator of cytokine withdrawal-induced apoptosis.

Growth factors and cytokines play an important role in supporting cellular viability of various tissues during development due to their ability to suppress the default cell death program in each cell type. To date, neither the triggering molecule nor the transduction pathway of these default apoptosis programs is understood. In this study, we explored the possibility that cytokine receptors are involved in modulating cytokine withdrawal-induced apoptosis (CWIA) in hematopoietic cells.

Conferral of an antiviral state to CD4+ cells by a zipper motif envelope mutant of the human immunodeficiency virus type 1 transmembrane protein gp41.

We showed in a transient coexpression study that a single proline substitution for any of the five conserved leucine or isoleucine residues located in the envelope (Env) transmembrane protein gp41 zipper motif of the human immunodeficiency virus type 1 dominantly interferes with wild-type Env-mediated viral infectivity. In the present study, we intended to explore the feasibility of developing a genetic anti-HIV strategy targeting the zipper motif. Stable HeLa-CD4-LTR-beta-gal clones that harbored silent copies of Tat-regulated expression cassettes encoding the zipper motif Env mutants were first generated.

trans-dominant interference with human immunodeficiency virus type 1 replication and transmission in CD4(+) cells by an envelope double mutant.

We previously reported that a human immunodeficiency virus type 1 (HIV-1) envelope (Env) mutant with the whole cytoplasmic domain deleted, denoted mutant TC, is able to dominantly interfere with wild-type (wt) virus infectivity. In the present study, the feasibility of developing a dominant negative mutant-based genetic anti-HIV strategy targeting the gp41 cytoplasmic domain was investigated. Mutants TC and 427,TC, a TC derivative with a Trp-to-Ser substitution introduced into residue 427 in the CD4-binding site, and a series of mutants with deletions in the cytoplasmic domain, effectively trans-dominantly interfered with wt Env-mediated viral infectivity, as demonstrated by an env trans-complementation assay.

Subcellular localization of the Streptococcus mutans P1 protein C terminus.

To determine the subcellular location of the Streptococcus mutans P1 protein C-terminal anchor, cell envelope fractionation experiments were conducted in combination with Western immunoblotting, using monoclonal antibody MAb 6-8C specific for an epitope that maps near the C terminus of P1 protein and also a polyclonal antibody preparation directed against the P1 C-terminal 144 amino acids (P1COOH). P1 protein was detected in cell walls but not the membrane purified from S. mutans cells by the monoclonal antibody.

Cutting edge: a short polypeptide domain of HIV-1-Tat protein mediates pathogenesis.

HIV-1 encodes the transactivating protein Tat, which is essential for virus replication and progression of HIV disease. However, Tat has multiple domains, and consequently the molecular mechanisms by which it acts remain unclear. In this report, we provide evidence that cellular activation by Tat involves a short core domain, Tat21-40, containing only 20 aa including seven cysteine residues highly conserved in most HIV-1 subtypes.

Surface expression of a protective recombinant pertussis toxin S1 subunit fragment in Streptococcus gordonii.

In this study, the expression of the Bordetella pertussis S1 subunit was tested in Streptococcus gordonii, a commensal oral bacterium which has the potential to be a live oral vaccine vehicle. The DNA fragment encoding the N-terminal 179 amino acids of the S1 subunit was ligated into the middle part of spaP, the surface protein antigen P1 gene originating from Streptococcus mutans. The resulting construct, carried on the Escherichia coli-Streptococcus shuttle vector pDL276, was introduced into S.

A G protein gamma subunit-like domain shared between RGS11 and other RGS proteins specifies binding to Gbeta5 subunits.

Regulators of G protein signaling (RGS) proteins act as GTPase-activating proteins (GAPs) toward the alpha subunits of heterotrimeric, signal-transducing G proteins. RGS11 contains a G protein gamma subunit-like (GGL) domain between its Dishevelled/Egl-10/Pleckstrin and RGS domains. GGL domains are also found in RGS6, RGS7, RGS9, and the Caenorhabditis elegans protein EGL-10.

Dopamine D4 receptor gene polymorphisms and neuroleptic response in schizophrenia.

Background: Dopamine D4 receptor (DRD4) gene polymorphisms are associated with various pharmacologic activities. This study investigated whether polymorphisms of 48-bp tandem repeats in the exon 3 of the DRD4 gene are related to neuroleptic response.

Methods: The neuroleptic response at the acute stage of schizophrenia was assessed in 80 (48 men, 32 women) schizophrenic patients.

Regulation of the p21-activated kinase-related Dictyostelium myosin I heavy chain kinase by autophosphorylation, acidic phospholipids, and Ca2+-calmodulin.

The Dictyostelium myosin I heavy chain kinase (MIHCK) is a member of the p21-activated kinase family (Lee, S.-F., Egelhoff, T.

Tropism, coreceptor use, and phylogenetic analysis of both the V3 loop and the protease gene of three novel HIV-1 group O isolates.

HIV-1 has been subdivided into two groups, M and O, based on phylogenetic analysis. To better understand the pathogenesis of group O viruses, we studied biologic and genetic characteristics of two primary isolates from Spain, ES1158.1 and ES1159.

mcl-1 is an immediate-early gene activated by the granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling pathway and is one component of the GM-CSF viability response.

mcl-1, a bcl-2 family member, was originally identified as an early gene induced during differentiation of ML-1 myeloid leukemia cells. In the present study, we demonstrate that Mcl-1 is tightly regulated by the granulocyte-macrophage colony-stimulating factor (GM-CSF) signaling pathway. Upon deprivation of survival factor from TF-1 myeloid progenitor cells, Mcl-1 levels quickly dropped prior to visible detection of apoptosis of these cells.

Mutations in the leucine zipper-like heptad repeat sequence of human immunodeficiency virus type 1 gp41 dominantly interfere with wild-type virus infectivity.

It has been previously shown that a proline substitution for any of the conserved leucine or isoleucine residues located in the leucine zipper-like heptad repeat sequence of human immunodeficiency virus type 1 (HIV-1) gp41 renders viruses noninfectious and envelope (Env) protein unable to mediate membrane fusion (S. S.-L.

The myxoma virus M-T4 gene encodes a novel RDEL-containing protein that is retained within the endoplasmic reticulum and is important for the productive infection of lymphocytes.

To investigate the contribution of the myxoma virus M-T4 gene to viral virulence, both copies of the M-T4 gene were inactivated by disruption and insertion of the Escherichia coli guanosine phosphoribosyltransferase gene. Infection of European rabbits with the recombinant M-T4-deleted virus, vMyxlacT4, resulted in disease attenuation. In contrast, infection of rabbits with vMyxlac elicited the classical features of lethal myxomatosis.

Adenylosuccinate synthetase from maize. Purification, properties, and mechanism of inhibition by 5'-phosphohydantocidin.

Adenylosuccinate synthetase (AdSS) is the site of action hydantocidin, a potent microbial phytotoxin. A kinetic analysis of the mode of inhibition of a plant adenylosuccinate synthetase by the active metabolite 5'-phosphohydantocidin (5'-PH) was the objective of the present study. AdSS was purified 5800-fold from maize (Zea mays), to our knowledge the first purification of the enzyme from a plant source.

Couples' satisfaction with health care service during labor and delivery.

The purpose of this study was to examine consumer satisfaction with health care service during labor and delivery. An exploratory study was conducted by obtaining information from 191 couples who were hospitalized at one medical center in southern Taiwan. A Consumer Satisfaction Questionnaire with three additional open questions developed by the authors and a Social Support Scale modified from the Family APGAR Index were administered.

Concordance of positive and negative symptoms in coaffected sib-pairs with schizophrenia.

Positive and negative symptom (NGS) dimensions were examined for their concordance in 46 coaffected schizophrenic sib-pairs. Results showed that the symptom dimensions of negative symptoms (NGS), delusion-hallucination (DHS), and thought disorganization (TDS) could be formulated. Discrete genetic endowment of these three symptom dimensions was not found as shown by the low concordance in sib pair analysis (kappa = 0.

Oral recrudescent herpes simplex virus infection.

Objective: The objective of this study is to determine the frequency of involvement of different intraoral sites by oral recrudescent herpes simplex virus in immunocompromised patients and whether keratinized intraoral sites are always affected by this virus.

Study Design: The records of 30 hospitalized patients who had oral ulcers culture positive for herpes simplex virus were reviewed for the location of oral ulcers, febrile episodes, and medical diagnoses.

Results: The data revealed that oral recrudescent herpes simplex virus may involve any intraoral site in immunocompromised patients with nonkeratinized sites representing approximately half of all sites; this is more frequent than has been previously reported.

Inhibitory effects of phytopolyphenols on TPA-induced transformation, PKC activation, and c-jun expression in mouse fibroblast cells.

The effects of 12 phytopolyphenols, including 3 catechin derivatives, 8 flavanols, and curcumin, on 12-O-tetradecanoylphorbol 13-acetate (TPA)-induced transformation in mouse fibroblast cells are described. The location of hydroxyl functional groups at 2', 3', or 4' site(s), especially at the 4' site, as in apigenin, fisetin, morin, myricetin, and quercetin, seems essential for anti-TPA-induced transformation, anti-protein kinase C (PKC) activation, and anti-TPA-induced c-jun expression activities. Among the catechin derivatives, those with a cis form structure and with an additional hydroxyl group at the R1 site and galloyl groups at the R2 site, such as epigallocatechin gallate, have stronger inhibitory effects on the above-mentioned biochemical activities.

Activation of myosin-I by members of the Ste20p protein kinase family.

The heavy chain of myosin-ID isolated from Dictyostelium was identified as an in vitro substrate for members of the Ste20p family of serine/threonine protein kinases which are thought to regulate conserved mitogen-activated protein kinase pathways. Yeast Ste20p and Cla4p and mammalian p21-activated protein kinase (PAK) phosphorylated the heavy chain to 0.5-0.