Purification of a cytochrome bd terminal oxidase encoded by the Escherichia coli app locus from a delta cyo delta cyd strain complemented by genes from Bacillus firmus OF4.

Escherichia coli GK100, with deletions in the operons encoding its two terminal oxidases, cytochrome bo and ctyochrome bd, was complemented for growth on succinate by a recombinant plasmid (pMS100) containing a 3.4-kb region of DNA from alkaliphilic Bacillus firmus OF4. The complementing DNA was predicted to encode five proteins, but neither sequence analysis nor complementation experiments with subclones provided insight into the basis for the complementation.

Simplified ganglioside composition of photoreceptors compared to other retinal neurons.

Purpose: The quantitative and qualitative ganglioside composition of retinal photoreceptor cells is unknown. The aim of this study was to analyze the lipid, especially ganglioside, make-up of photoreceptors compared to other retinal cells.

Methods: Retinas from adult normal rats were mechanically separated into outer (photoreceptors) and inner (other retinal neurons and glia) halves be planar vibratome sectioning.

Pharmacokinetic interaction between multiple-dose venlafaxine and single-dose lithium.

Venlafaxine is a structurally novel antidepressant. Because lithium and antidepressants may be administered concomitantly, it is important to determine whether the disposition of venlafaxine and lithium is affected by coadministration. An open-label study was conducted to evaluate the effects of multiple-dose, steady-state venlafaxine administration on the pharmacokinetics of a single oral dose of lithium.

Monosialoganglioside GM1 reduces ischemia--reperfusion-induced injury in the rat retina.

Purpose: Gangliosides are normal components of cell membranes, contribute to structural rigidity and membrane function, and have been shown to protect against various insults to the brain. This study evaluates the effect of exogenously administered monosialoganglioside GM1 on retinal damage induced by transient retinal ischemia and reperfusion.

Methods: Retinal ischemia was induced unilaterally in Long Evans rats by increasing intraocular pressure to 160 mm Hg for 60 minutes.

Mastocytosis presenting as a skeletal disorder.

Mastocytosis is a rare disease of mast-cell proliferation with involvement of the reticuloendothelial systems including skin, bone, gastrointestinal tract, liver, lungs, spleen, and lymph nodes. Systemic mastocytosis is characterized by a combination of symptoms that relate to the mast cells' release of vasoactive substances, such as histamine. These symptoms include urticaria pigmentosa, flushing, syncope with hypotension, headaches, nausea, vomiting, diarrhea, and occasional bronchospasm.

Rapamycin: distribution, pharmacokinetics, and therapeutic range investigations.

Rapamycin (RAPA) is a potent immunosuppressive drug that is presently undergoing clinical trials. The most of the drug is sequestered in erythrocytes resulting in whole blood concentrations being considerably higher than plasma concentrations. The drug is metabolized by the same P450 3A enzyme that is involved in the metabolism of cyclosporine and tacrolimus.

Risk factor assessment for the acquisition of fluoroquinolone-resistant isolates of Pseudomonas aeruginosa in a community-based hospital.

A case-control study was performed in a community-based nonteaching hospital to assess patient risk factors for the acquisition of fluoroquinolone-resistant isolates of Pseudomonas aeruginosa. Fifty-five patients who were hospitalized between July 1, 1993 and December 31, 1993 and who had P. aeruginosa recovered from a clinical specimen were included in the analysis.

Rate of degeneration of human acetabular cartilage after hemiarthroplasty.

Biopsy specimens of cartilage and subchondral bone were obtained from the weight-bearing dome of the acetabulum in twelve elderly patients who were having a revision of a hemiarthroplasty of the hip because of pain. Biopsy specimens of acetabular cartilage and subchondral bone were also obtained from eight patients of comparable age who were having a primary hemiarthroplasty for a displaced fracture of the femoral neck; these served as the control specimens. The specimens were stained with hematoxylin and eosin for the initial histological assessment of cartilage structure and cellularity as well as the integrity of the tidemark.

Phonational profiles of male trained singers and nonsingers.

The purpose of this study was to compare the mean speaking fundamental frequency (SFF), speaking frequency range, and mean speaking intensity for a group of trained male singers and a group of age-matched non-singers in three age ranges: 20 to 35 years old; 40 to 55 years old; and older than 65 years. Each subject was recorded as he read "The Rainbow Passage" and produced the vowel /a/ to the limits of his phonational frequency range. The data indicated that the mean SFF of the nonsingers was significantly lower among the middle-aged speakers than with the young or elderly.

Purification of three catalase isozymes from facultatively alkaliphilic Bacillus firmus OF4.

Cell extracts of facultatively alkaliphilic B. firmus OF4 were assayed for catalase activity and their catalase isozyme content was analyzed on native polyacrylamide gels stained for catalase activity. pH-10.

Shared phenotypic expression of osteoblasts and chondrocytes in fracture callus.

Endochondral ossification in fracture healing of rats at 4, 8, 11, 14, and 21 days was analyzed using immunological and molecular probes for markers of the chondrocyte and osteoblast phenotype. These markers were osteocalcin, type I and type II collagen, including the probes homologous to the alternatively spliced forms of alpha 1 type II collagen, type IIA and type IIB. Histologic examination was performed on serial sections of the same tissue blocks to correlate cellular morphology with the immunohistochemical and in situ hybridization findings.

Primary lymphoma of bone. Correlation of magnetic resonance imaging features with cytokine production by tumor cells.

Background: Primary lymphoma of bone is a rare, aggressive neoplasm that can present with a large, soft-tissue mass despite minimal evidence of cortical destruction on plain radiographs.

Methods: High resolution magnetic resonance imaging (MRI) examinations of four patients with primary lymphoma of bone were reviewed retrospectively, and in each case intramedullary tumors demonstrated "penetrating channels" extending through the cortex. The MRI studies were correlated with the histopathologic assessment of the tumor for each patient.

Apoptosis in colorectal tumour cells: induction by the short chain fatty acids butyrate, propionate and acetate and by the bile salt deoxycholate.

The short chain fatty acids acetate, propionate and butyrate are produced when dietary fibre is fermented by the colonic bacteria. We have previously shown that sodium butyrate induces apoptosis in 3 colorectal tumour cell lines. We have extended our study to 3 adenoma and 4 carcinoma cell lines and investigated whether propionate and acetate also induce apoptosis.

Differential tumor necrosis factor expression by resident retinal cells from experimental uveitis-susceptible and -resistant rat strains.

Experimental autoimmune uveoretinitis (EAU) and endotoxin-induced uveitis (EIU), models for human ocular immunopathological syndromes, result in ocular inflammation in susceptible, but not in resistant rat strains. Moreover rapid photoreceptor degeneration occurs in susceptible rats developing EAU. In order to see whether differences in local ocular immune regulation may account for changes in resistance or susceptibility, we have examined the in vitro production of the cytotoxic cytokine tumor necrosis factor (TNF) by two resident ocular cell types, retinal Müller glia (RMG) and retinal pigmented epithelium (RPE).

BCL-2 expression in human colorectal adenomas and carcinomas.

As BCL-2 oncoprotein has been implicated as a survival factor in a number of tissues, we examined colorectal tumour specimens and cell lines for BCL-2 expression. BCL-2 protein was expressed in 19/22 adenocarcinomas and 12/13 adenomas. 6/9 carcinoma cell lines and 7/8 adenoma cell lines were also BCL-2 positive.

Analysis of type II and type X collagen synthesis in cultured growth plate chondrocytes by in situ hybridization: rapid induction of type X collagen in culture.

Type X collagen is produced by hypertrophic chondrocytes and serves as a highly specific marker for chondrocyte maturation. This study was designed to compare the expression of type II and type X collagen in growth plate sections and in distinct populations of chondrocytes in culture by in situ hybridization. Growth plate sections were treated with type II and type X collagen cDNA probes.

Comparison of the influence of spermicidal and non-spermicidal contraception on bacterial vaginosis, candidal infection and inflammation of the vagina--a preliminary study.

This preliminary study compared the signs, symptoms and prevalence of bacterial vaginosis (BV) and candidal infections in women using spermicides, with those using other forms of contraception, to establish whether nonoxynol-9 had any therapeutic value against BV or gave rise to vaginal candidiasis and inflammation. Overall results showed that the prevalence of BV in non-spermicide users was 35/113 (31%) but was significantly less in spermicide users, 10/66 (15%), P < 0.05.

The abundance of atp gene transcript and of the membrane F1F0-ATPase as a function of the growth pH of alkaliphilic Bacillus firmus OF4.

Molecular biological and biochemical studies of the F(1)F(0)-ATP synthase of alkaliphilic Bacillus firmus OF4 show that the enzyme used at pH 7.5 and pH 10.5 is a unique product of the atp operon, expressed at the same levels and yielding an enzyme with the same subunit properties and c-subunit/holoenzyme stoichiometry.

Reconstitution of energy-linked activities of the solubilized F1F0 ATP synthase from Bacillus subtilis.

The F1F0 ATP synthases from wild-type Bacillus subtilis and an uncoupler-resistant mutant have comparable subunit structures. In accord with an earlier hypothesis, ATP hydrolysis and ATP-Pi exchange by the two synthases were equally stimulated and inhibited by protonophores, respectively, when reconstituted alone in either wild-type or mutant lipids.

Induction and regulation of nitric oxide synthase in retinal Müller glial cells.

Müller glial cells from the rat retina were examined for their capacity to produce nitric oxide (NO). Treatment of retinal Müller glial (RMG) cells with lipopolysaccharide (LPS), interferon-gamma, and tumor necrosis factor-alpha induced NO synthesis as determined by nitrite release in media. Simultaneous addition of LPS, interferon-gamma, and tumor necrosis factor-alpha caused the largest increase in NO synthesis.

Superoxide inhibits proliferation and phagocytic internalization of photoreceptor outer segments by bovine retinal pigment epithelium in vitro.

Experiments were performed to investigate the effect of free radical damage on two aspects of retinal pigmented epithelium (RPE) metabolism, namely, proliferation and phagocytosis. Bovine RPE cells were maintained in monolayer cultures, either as passaged (for proliferation and lysosomal activity assays) or primary cultures (for phagocytosis measurements). Free radicals (superoxide anions) were generated by a xanthine oxidase (XO)-hypoxanthine (HX) reaction.