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Biomedical subjects

M Alexander

Publications and source records attributed to M Alexander.

At least 145 records · Page 8Linked to original sources
PubMed1992

Infection control.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1992

The prognostic significance of race and survival from laryngeal carcinoma.

Surveillance, Epidemiology, and End Results (SEER) program data suggest that blacks with laryngeal carcinoma have a significantly lower 5-year survival rate than whites. Most of this difference persists despite adjustment for "crude stage." To evaluate possible factors contributing to this residual survival deficit, 190 white and 23 black patients treated at the Martinez Veterans Administration Hospital between 1968 and 1988 were studied. The independent impact of race on survival rate was analyzed with respect to various prognostic factors including treatment delay, elapsed time (diagnosis to treatment), age, stage, cancer subsites, and type of therapy. No independent prognostic significance could be attributed to race. The differences noted in SEER data probably reflect a tendency for the use of crude stage to underestimate the impact of prognostic groups within the categories of "local" and "regional" disease, the independent prognostic significance of subsites (glottic versus supraglottic), and the variable distribution of these subsites in different populations. This study suggests that when stage, subsite, and quality of care are adequately considered, survival from laryngeal cancer in blacks is comparable to that of whites.

Adult↗
PubMed1991

[Tuberculosis of the larynx, oral cavity and pharynx].

A 44-year-old man, a heavy smoker over many years, complained of hoarseness for 8 weeks with weight loss and dysphagia. Malignant tumour of the pharynx was suspected. Examination revealed a swelling of the right upper lip, tumorous changes in the right buccal mucosa, about 6 x 6 cm in size, as well as enlargement of the cervical lymph-nodes. Microlaryngoscopy revealed a three-level tumour of the entire side of the right larynx. Histological examination of biopsies of the right false and true vocal cords as well as the buccal mucosa demonstrated numerous, partly caseous epithelioid granulomas with Langhans giant cells. Ziehl-Neelsen staining showed acid-fast rods. Combined tuberculostatic treatment with isoniazid, rifampicin, ethambutol and pyrazinamide achieved regression of all signs and symptoms within two months. This case emphasizes the need for including laryngeal tuberculosis in the differential diagnosis of seemingly malignant laryngeal tumours.

Adult↗
PubMed1991

Clinical evaluation of the efficacy and safety of noberastine, a new H1 antagonist, in seasonal allergic rhinitis: a placebo-controlled, dose-response study.

Noberastine (NOB), a new histamine H1 antagonist, has potent and specific peripheral antihistaminic activity. To evaluate the efficacy and safety of NOB in ragweed seasonal allergic rhinitis, 250 eligible patients were randomized to one of four parallel, double-blind treatment groups: NOB, 10, 20, and 30 mg, or placebo, each administered once daily for 3 weeks. Rescue medication was prohibited. Efficacy parameters included global response rate (percentage of responders), physician visit, patient-diary symptom scores, and onset of action. Efficacy analyses used alpha = 0.0167 (adjusted for multiple comparisons). Efficacy parameters demonstrated universal superiority of NOB therapy over placebo therapy with statistical significance achieved frequently; no statistically or clinically significant separation was demonstrated among NOB-treated groups. Global-response rates for all active-treatment groups (range, 62.7% to 71.1%) were statistically significantly greater than rates for the placebo-treated group (39.6%). Median time to first relief of symptoms was within 2 to 4 hours for NOB-treated groups versus 72 hours for the placebo-treated group. No significant abnormalities in safety parameters were ascribed to NOB treatment. Incidence and severity of adverse experiences of NOB-treated groups were comparable in incidence and severity to placebo treatment. NOB treatment did not appear to cause weight gain or sedation. Once-daily NOB, 10, 20, and 30 mg, is equally and highly effective and safe in the symptomatic management of seasonal allergic rhinitis compared to placebo.

Adolescent↗
PubMed1991

Relationship between Cell Surface Properties and Transport of Bacteria through Soil.

A study was conducted to relate the properties of Enterobacter, Pseudomonas, Bacillus, Achromobacter, Flavobacterium, and Arthrobacter strains to their transport with water moving through soil. The bacteria differed markedly in their extent of transport; their hydrophobicity, as measured by adherence to n-octane and by hydrophobic-interaction chromatography; and their net surface electrostatic charge, as determined by electrostatic interaction chromatography and by measurements of the zeta potential. Transport of the 19 strains through Kendaia loam or their retention by this soil was not correlated with hydrophobicities or net surface charges of the cells or the presence of capsules. Among 10 strains tested, the presence of flagella was also not correlated with transport. Retention was statistically related to cell size, with bacteria shorter than 1.0 mum usually showing higher percentages of cells being transported through the soil. We suggest that more than one characteristic of bacterial cells determines whether the organisms are transported through soil with moving water.

Journal Article↗
PubMed1991

Biodegradation by an arthrobacter species of hydrocarbons partitioned into an organic solvent.

An Arthrobacter strain mineralized naphthalene and n-hexadecane dissolved in 2,2,4,4,6,8,8-heptamethylnonane. The extent of mineralization increased with greater volumes of solvent. Measurements under aseptic conditions of the partitioning of naphthalene into the aqueous phase from the solid phase or from heptamethylnonane showed that the rates were rapid and did not limit mineralization. The rate of mineralization of hexadecane was rapid, although partitioning of the compound into aqueous solution was not detected. The Arthrobacter sp. grown in media with or without heptamethylnonane did not excrete products that increased the aqueous solubility of naphthalene and hexadecane. Measurements of the number of cells in the aqueous phase showed that the Arthrobacter sp. attached to the heptamethylnonane-water interface, but attachment was evident even without a substrate in the heptamethylnonane. Tests with small inocula of the Arthrobacter sp. demonstrated that at least a portion of naphthalene or hexadecane dissolved in heptamethylnonane was degraded by cells attached to the solvent-water interface. The cells did not adhere in the presence of 0.1% Triton X-100. The surfactant prevented mineralization of the hexadecane initially dissolved in heptamethylnonane, but it increased the rate and extent of mineralization of naphthalene initially dissolved in heptamethylnonane. The data show that organic solvents into which hydrophobic compounds partition affect the biodegradation of those compounds and that attachment of microorganisms to the organic solvent-water interface may be important in the transformation.

Journal Article↗
PubMed1991

Effect of sodium chloride on transport of bacteria in a saturated aquifer material.

Determinations were made of the influence of NaCl concentration, cell density, and flow velocity on the transport of Pseudomonas sp. strain KL2 through columns of aquifer sand under saturated conditions. A pulse-type boundary condition was used. The experiments were conducted by using 0.3-m-long Plexiglas columns with an internal diameter of 0.05 m. When a 1-h pulse of a 0.01 M NaCl solution containing 10(8) cells per ml was added at a flow rate of 10(-4) m s-1, the bacterial density in the effluent never exceeded 2.2% of the density of cells added, and only 1.5% of the bacteria passed through the aquifer material. In contrast, when the bacteria were applied in distilled water, the relative cell density in the effluent approached 100%, and 60% of the bacteria were transported through the aquifer solids. Under these conditions, the breakthrough of Pseudomonas sp. strain KL2 was slower than chloride. When the flow rate was 2.0 x 10(-4) m s-1, the cell density in the effluent reached 7.3% of that added in 0.01 M NaCl solution, but only 3.9% of the bacteria were transported through the aquifer particles. On the other hand, the density in the effluent approached 100% of that added in deionized water, and 77% of the added bacteria were recovered. When the density of added cells was 10(9) cells per ml at a flow rate of 10(-4) m s-1, the densities in the effluent reached 70 and 100% of those added in salt solution and deionized water, respectively, and 44 and 57% of the bacteria were transported through the aquifer solids.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Movement↗
PubMed1990

Deregulated Bcl-2 gene expression selectively prolongs survival of growth factor-deprived hemopoietic cell lines.

The t(14;18) of human follicular B cell lymphoma translocates the Bcl-2 gene into the Ig H chain locus and markedly deregulates Bcl-2 expression. We sought to determine if Bcl-2 could be directly implicated in a growth-factor pathway. Consequently, we introduced a retrovirus containing the murine Bcl-2 gene (N2-M-Bcl-2) or the parental retrovirus (N2) into a series of factor-dependent hemopoietic cell lines. Overexpressed Bcl-2 resulted in no long term IL-2, IL-3, or IL-6 independent clones, indicating that Bcl-2 could not spare the need for a specific ligand-receptor interaction. However, Bcl-2 did extend the short term survival of IL-3-dependent cell lines after factor deprivation. Although viable, IL-3-deprived pro B lymphocytes (FL5.12) bearing N2-M-Bcl-2 were in Go, and deregulated Bcl-2 did not obviously influence cell-cycle progression. Bcl-2 predominant effects were to delay the onset of cell death and to modestly augment viable cell growth in the first 48 h after IL-3 deprivation. This death sparing was associated with increased levels of Bcl-2 RNA and protein in factor-deprived cells possessing N2-M-Bcl-2. This result was not restricted to prolymphocytes because an IL-3-dependent mast cell line (32D) as well as a promyeloid line (FDC-P1) demonstrated the same response to Bcl-2. Moreover, the effect was not limited to the IL-3/IL-3R signal transduction pathway in that promyeloid cells maintained in granulocyte-macrophage-CSF or IL-4 displayed a similar response. Yet, Bcl-2-enhanced cell survival was not universal as an IL-2-dependent T cell line, and an IL-6-dependent myeloma line demonstrated no consistent effect upon IL withdrawal. Thus, Bcl-2 appears to interfere with cell death but in a cell type and/or factor-restricted fashion.

Animals↗
PubMed1990

Collection and quality of rhesus monkey semen.

Electroejaculation is an accepted method of semen collection from nonhuman primates. Although both penile and rectal probe stimulation techniques have been used, there has been a general lack of consistency and detail regarding their application. This report describes the collection, processing, and evaluation of rhesus monkey semen contrasting two methods of penile electroejaculation: 1) a constant-voltage method where stimulus current is a variable and 2) a constant-current method where stimulus current is operator-controlled. The constant-current method was the more efficient procedure, requiring a lower stimulus current for successful electroejaculation. The influence on semen quality of potentially toxic agents used in the procedure, surgical glove powder and electrolyte cream, was tested; both were detrimental as measured by motility loss. No correlation was found between coagula volume and sperm numbers. The intra- and interanimal variability in semen samples from six monkeys was also evaluated. Penile electroejaculation, combined with control of stimulus current, provides a consistent, successful, and humane method for the collection of semen in the rhesus monkey.

Animals↗
PubMed1990

Effect of organic amendments on bacterial multiplication in lake water.

In Cayuga Lake water amended with 30 micrograms of glucose or amino acids per ml, an added strain of Pseudomonas fluorescens and indigenous bacteria grew extensively, Pseudomonas sp. B4 and two rhizobia multiplied at a moderate extent, and introduced Escherichia coli and Klebsiella pneumoniae multiplied but to only a slight degree. The amendments did not enhance growth of Micrococcus flavus and Arthrobacter citreus, and an asporogenous strain of Bacillus subtilis decreased in numbers. The pseudomonads, rhizobia, E. coli and K. pneumoniae multiplied extensively when inoculated into sterile lake water amended with amino acids, A. citreus grew to a slight extent, but the numbers of M. flavus and B. subtilis did not change appreciably. In nonsterile lake water amended with 30 micrograms of Trypticase soy broth per ml, the indigenous bacteria greatly increased in abundance, the pseudomonads, rhizobia, and E. coli developed to a lesser extent, the numbers of K. pneumoniae, A. citreus and M. flavus showed little increase, and B. subtilis decreased in numbers. Tests in pure culture containing 2 to 64 micrograms of Trypticase soy broth per ml demonstrated good growth of P. fluorescens, Pseudomonas sp. B4, and the rhizobia at all concentrations; an initial decline followed by growth of E. coli, K. pneumoniae and R. leguminosarum biovar phaseoli at low concentrations; little or no growth or decline at the low levels but multiplication at the high levels by A. citreus and B. subtilis; and decline of M. flavus. It is proposed that the apparent Ks value, mumax value, length of lag phase and resistance to stress can be used to predict behavior of bacteria in lake water receiving low levels of organic nutrients.

Amino Acids↗
PubMed1990

Home monitors for infants: use, misuse, and "over-the-counter" use.

The prevalence of "over-the-counter" monitors, was surveyed in infants referred to five Belgian paediatric centres between September 1987 and March 1988 for evaluation of their risk for sudden infant death (SID). Questionnaires were collected from 1625 families. Of the infants, 8.9% were already being monitored at home. For 78.1% of the infants no medical advice had been solicited, and for 21.9%, a paediatrician or a general practitioner had advised home monitoring without previous evaluation. Forty of 824 infants referred with no history of SID, and no history of apparent life-threatening event (ALTE), were monitored (4.8%). Monitoring was started for 3.8% (5 out of 130) of the infants who had lost a cousin or an uncle to SID, and for 22.2% (69 of 310) of the younger siblings of a SID victim. Of the 341 infants who had presented with an ALTE, monitoring was started in 32 (9.4%). The infants were monitored with respiratory monitors only, and in 86% of the monitors, the alarm delay had been regulated unnecessarily low.

Belgium↗
PubMed1990

An insulin response element in the glyceraldehyde-3-phosphate dehydrogenase gene binds a nuclear protein induced by insulin in cultured cells and by nutritional manipulations in vivo.

Two independent cis-acting insulin response elements (IREs) in the gene encoding glyceraldehyde-3-phosphate dehydrogenase [D-glyceraldehyde-3-phosphate: NAD+ oxidoreductase (phosphorylating), EC 1.2.1.12], designated IRE-A and IRE-B, are sufficient to direct insulin-inducible gene expression. Using the electrophoretic mobility shift assay, a 4-fold increase in the amount of IRE-A DNA bound to nuclear proteins was detected when extracts isolated from insulin-stimulated differentiated 3T3-L1 cells or from the liver of rats refed a high-carbohydrate/low-fat diet after a 72-hr fast were compared to control nuclear extracts. The points of contact between protein and IRE-A DNA may represent a sequence recognized by at least one class of insulin-sensitive transcription factor(s).

Animals↗