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Biomedical subjects

M Wilson

Publications and source records attributed to M Wilson.

At least 253 records · Page 14Linked to original sources
PubMed1998

Characterization of type IV pilus genes in Pseudomonas syringae pv. tomato DC3000.

Many strains of Pseudomonas syringae produce retractile pili that act as receptors for lytic bacteriophage phi 6. As these are also characteristics of type IV pili, it was postulated that P. syringae may possess genes for type IV pilus biogenesis. A cosmid clone bank of P. syringae pv. tomato DC3000 genomic DNA was used to complement a mutant of Pseudomonas aeruginosa defective in the PilD (XcpA) prepilin peptidase gene by selection for restoration of extracellular protein secretion, a function also known to require PilD. A cosmid able to complement this mutant was also able to complement mutations in the pilB and pilC genes, suggesting that, if the organization of these genes is similar to that of P. aeruginosa, the cosmid may contain the P. syringae pilA. This was confirmed by sequencing a region from this plasmid that was shown to hybridize at low stringency to the P. aeruginosa pilA gene. The deduced P. syringae PilA polypeptide possesses the characteristic properties of the type IV pilins. Heterologous expression of the P. syringae pilA in P. aeruginosa was also shown, conferring not only phi 6 phage sensitivity to P. aeruginosa pilA mutants but also sensitivity to PO4, a lytic bacteriophage specific for the pilus of P. aeruginosa. This suggests that additional components might be present in the mature pilus of P. aeruginosa that are the true receptors for this phage. Chromosomal mutations in P. syringae pv. tomato DC3000 pilA and pilD genes were shown to abolish its sensitivity to bacteriophage phi 6. To determine the importance of P. syringae pilus in plant leaf interactions, these mutations were tested under laboratory and field conditions. Although little effect was seen on pathogenicity, culturable leaf-associated population sizes of the pilA mutant were significantly different from those of the wild-type parent. In addition, the expression of the DC3000 pilA gene appears to contribute to the UV tolerance of P. syringae and may play a role in survival on the plant leaf surface.

Amino Acid Sequence↗
PubMed1998

Measuring the ability to meet family needs in an intensive care unit.

OBJECTIVE: To measure the ability to meet family needs in an intensive care unit (ICU). DESIGN: Descriptive survey. SETTING: University hospital ICU. SUBJECTS: Ninety-nine next of kin respondents and 16 secondary family respondents were recruited. INTERVENTIONS: A modified Society of Critical Care Medicine Family Needs Assessment instrument was used. MEASUREMENTS AND MAIN RESULTS: Demographic variables included patient age, gender, diagnosis, Acute Physiology and Chronic Health Evaluation (APACHE) II score on admission, Therapeutic Intervention Scoring System (TISS) score on the date of interview, cumulative TISS of the ICU on the day of interview, number of patients in the ICU at time of interview, nurse/patient ratio for the patient, average nurse/patient ratio of the entire unit, day of the week of the interview, timing of the interview, number of ICU attending physicians who cared for this patient (scheduled for a period of seven consecutive days), number of nurses who cared for the patient, if a nurse was assigned the same patient on two consecutive days worked, length of stay in the ICU, and length of hospital stay. Demographic information concerning the family member included gender, age, commuting time to the hospital, visiting time in the hospital per day, number in family group, relationship to the patient, ethnic background, and education level. The additive score of all questions in the needs assessment instrument was calculated and used as the dependent variable. The independent variables were demographic information concerning patients, ICU, and respondents. The model coefficient of determination (R2adj) was 0.20 with a p = .0079. Greater family dissatisfaction (i.e., higher score) was present if there were more than two ICU attendings per patient (p = .048), or if the same nurse was not assigned on two consecutive days (p = .044). Family satisfaction increased if the respondent was female (p = .006), if the patient had a higher APACHE II score (p = .007), and if the patient's relationship with the most significant family member was brother/sister (p = .012). The family needs instrument was reliable and demonstrated a high degree of concordance with a second respondent in the same family surveyed. CONCLUSIONS: Communication by the same provider was important when measuring the ability of an ICU to meet family needs. Instrument scores and the ability to meet family needs differed depending on the gender and the relationship to the patient of the most significant family member. We speculate that this instrument may be a useful adjunct in assessing quality of critical care services provided.

APACHE↗
PubMed1998

Data-driven quality improvement for HMO patients: one agency's experience with OASIS and OBQI.

The authors determined whether a home health agency could use Outcome Assessment and Information Set (OASIS) items and the Outcome-Based Quality Improvement (OBQI) model to enhance outcomes for health maintenance organization (HMO) patients. After an initial baseline period and four quarters of quality improvement activities, Improvement and Stabilization scores showed few significant changes. When the results were reviewed, investigators considered both the HMO authorization patterns and challenges encountered in using the OASIS-OBQI paradigm.

Aged↗
PubMed1998

Effects of creatine supplementation on body composition, strength, and sprint performance.

PURPOSE: To determine the effects of 28 d of creatine supplementation during training on body composition, strength, sprint performance, and hematological profiles. METHODS: In a double-blind and randomized manner, 25 NCAA division IA football players were matched-paired and assigned to supplement their diet for 28 d during resistance/agility training (8 h x wk[-1]) with a Phosphagen HP (Experimental and Applied Sciences, Golden, CO) placebo (P) containing 99 g x d(-1) of glucose, 3 g x d(-1) of taurine, 1.1 g x d(-1) of disodium phosphate, and 1.2 g x d(-1) of potassium phosphate (P) or Phosphagen HP containing the P with 15.75 g x d(-1) of HPCE pure creatine monohydrate (HP). Before and after supplementation, fasting blood samples were obtained; total body weight, total body water, and body composition were determined; subjects performed a maximal repetition test on the isotonic bench press, squat, and power clean; and subjects performed a cycle ergometer sprint test (12 x 6-s sprints with 30-s rest recovery). RESULTS: Hematological parameters remained within normal clinical limits for active individuals with no side effects reported. Total body weight significantly increased (P < 0.05) in the HP group (P 0.85 +/- 2.2; HP 2.42 +/- 1.4 kg) while no differences were observed in the percentage of total body water. DEXA scanned body mass (P 0.77 +/- 1.8; HP 2.22 +/- 1.5 kg) and fat/bone-free mass (P 1.33 +/- 1.1; HP 2.43 +/- 1.4 kg) were significantly increased in the HP group. Gains in bench press lifting volume (P -5 +/- 134; HP 225 +/- 246 kg), the sum of bench press, squat, and power clean lifting volume (P 1,105 +/- 429; HP 1,558 +/- 645 kg), and total work performed during the first five 6-s sprints was significantly greater in the HP group. CONCLUSION: The addition of creatine to the glucose/taurine/electrolyte supplement promoted greater gains in fat/bone-free mass, isotonic lifting volume, and sprint performance during intense resistance/agility training.

Adult↗
PubMed1998

Characterisation and molecular typing of Burkholderia pseudomallei: are disease presentations of melioidosis clonally related?

Eighteen cases of culture positive melioidosis caused by Burkholderia pseudomallei, were seen in four geographically separate communities in North Queensland, Australia. The genetic inter-relatedness of the clinical isolates were compared utilising random amplification of polymorphic DNA (RAPD) and multilocus enzyme electrophoresis (MEE). The isolates segregated into two groups that correlated with clinical presentation rather than geographical location. This is the first described association between the varied clinical presentations of this condition and specific molecular type. If proven on larger studies, this may further our understanding of the pathogenesis of this important condition.

Adolescent↗
PubMed1998

Functional and molecular characterization of teleost leukocytes.

The coupling of immunologically relevant in vitro assay systems, cell separation techniques, and the development of distinct clonal leukocyte lines has established the existence of T, B, natural killer, and accessory cell equivalents in teleosts. B cells are directly defined by monoclonal antibodies to teleost immunoglobulin (Ig) and identification of Ig H and L chain genes. As in mammals, fish B cells show Ig H-chain gene rearrangements, allelic exclusion, produce both membrane-bound and secreted forms of Ig, and transduce intracellular proliferative signals upon anti-Ig cross-linking. It has also been found that some fish B cells express a unique chimeric Ig chain with sequence homology to mammalian Ig delta. Teleost T cells are still indirectly defined as sIg- lymphocytes due to a lack of definitive surface markers. These mIg- lymphocytes are the responding cells in mixed leukocyte cultures, proliferate specifically to autologously processed and presented antigen, provide helper function for in vitro antibody responses, and produce interleukin-like factors upon activation. Recent identification of teleost T-cell receptor alpha and beta genes has now permitted the unequivocal genetic demonstration that some of these mIg- cells are bona fide T cells. It is anticipated that such long-term clonal cell lines will be indispensable tools for dissecting the physiology, biochemistry and molecular biology of teleost immune responses.

Animals↗
PubMed1998

Influence of growth mode and sucrose on susceptibility of Streptococcus sanguis to amine fluorides and amine fluoride-inorganic fluoride combinations.

This study evaluated the susceptibility to amine fluorides (AmFs) of planktonic and biofilm cultures of Streptococcus sanguis grown with and without sucrose. Cultures were incubated with AmFs (250 mg of fluoride liter-1) for 1 min. The susceptibility of biofilms was less than that of the planktonic form and was further decreased by growth in the presence of sucrose.

Amines↗
PubMed1998

Molecular characterization of an outer membrane protein of Actinobacillus actinomycetemcomitans belonging to the OmpA family.

The major outer membrane protein (OMP) of Actinobacillus actinomycetemcomitans is an OmpA homolog that demonstrates electrophoretic heat modifiability. The gene encoding this protein was isolated from a genomic library of A. actinomycetemcomitans NCTC 9710 by immunoscreening with serum from a patient with localized juvenile periodontitis. Expression of the cloned gene in Escherichia coli and subsequent Western blot analysis revealed a protein with an approximate molecular mass of 34 kDa. The amino acid sequence predicted from the cloned gene demonstrated that the mature protein had a molecular mass of 34,911 Da and significant identity to members of the OmpA family of proteins. We have named the major OMP of A. actinomycetemcomitans Omp34, and its corresponding gene has been named omp34.

Aggregatibacter actinomycetemcomitans↗
PubMed1998

Age-dependent reductions in A1 adenosine receptor expression in rat testes.

The rat testis expresses high levels of A1 adenosine receptors (A1 AR) that couple to the inhibition of adenylyl cyclase activity. However, the physiological role of these receptors in the testis is not clear. Previous studies have documented a number of changes in the testis associated with the aging process. The goal of this study was to assess whether alteration in the expression and function of the testicular A1 AR occurs in aging, using the Fischer 344 rats as an aging model. Quantitation of A1 AR expression by radioligand binding of [3H]1,3-dipropyl-8-cyclopentylxanthine, an antagonist radioligand, indicates reductions in receptor number by 35 +/- 13.3 and 53 +/- 18.2% in 18- and 25-mo-old rats, respectively, compared with 3-mo-old rats. Similar reductions in A1 AR expression were determined using Western blotting and receptor autoradiography. Quantitation of the Gi proteins using selective antibodies indicate age-dependent reductions in the levels of alpha i-1,2-, alpha i-3- and beta-subunits. Furthermore, the modulatory influences of guanosine 5'-O-(3-thiotriphosphate) on the binding of agonist and antagonist radioligands to the A1 AR were substantially reduced. Northern blotting analysis of rat testicular poly(A)+ RNA indicates both a 3.4-kb transcript and a 5.6-kb transcript that hybridized to the canine A1 AR cDNA probe. The levels of the 5.6-kb transcript were decreased by 24 +/- 18 and 52 +/- 3% in the 18- and 25-mo-old rats, respectively, compared with the 3-mo-old rats. These results indicate age-dependent deficits in the A1 AR signal transduction pathway in the testes and predict concomitant reductions in the action of adenosine.

Aging↗
PubMed1998

Effect of chronic fluoride exposure in uremic rats.

This study was conducted to test the hypothesis that the margin of safe fluoride exposure is narrowed in rats that are physiologically compromised by renal dysfunction. The study objective was to determine whether increases in fluoride retention and tissue fluoride levels in rats with surgically induced renal insufficiency result in toxic fluoride effects not ordinarily observed in healthy animals. Uremic and sham-operated control rats received 0 microg/ml, 5 (0.26 mmol/l), 15 (0.79), or 50 microg/ml (2.63 mmol/l) of fluoride in their drinking water for 3 or 6 months. Fluoride retention was monitored, and, following euthanasia, tissue fluoride and biochemical markers of tissue function were analyzed. Selected tissues were saved for histology, and bone marrow cells were harvested for determining the frequency of sister chromatid exchange, a marker of genetic damage. In spite of significantly higher levels of fluoride in the tissues of the animals with renal insufficiency, there were no clinically adverse, fluoride-induced, extraskeletal physiological, biochemical, or genetic effects of chronic exposure to common levels of fluoride in these rats.

Animals↗
PubMed1998

Diagnosis of deep venous thrombosis by use of soluble necrosis factor receptor.

The purpose of this clinical study was to find a relationship between soluble tumor necrosis factor (TNF) receptor, deep venous thrombosis (DVT), and pulmonary emboli (PE). Clinical diagnosis of deep venous thrombosis and pulmonary emboli is a major dilemma for the clinician. Most existing tests are technician dependent, are expensive, or require sophisticated equipment. Advances in molecular biology will permit investigation of the value of TNF receptor as a test for screening, diagnosis, and evolution of DVT and PE. Forty patients with diagnosis of DVT, documented by real-time ultrasound imaging, were the subject of this clinical study. Five cc of plasma from each patient was studied by enzyme-linked immunosorbent assay (Elisa) for measurement of soluble TNF receptor. Significantly increased concentration of plasma-soluble TNF receptor was present in patients with DVT as opposed to normal individuals. There was a close relationship between plasma concentration of soluble TNF receptor and evaluation of the disease. In this preliminary clinical study, it appears that plasma measurement of soluble TNF receptor could be used as a clinical test for diagnosis of DVT and PE.

Adult↗
PubMed1998

Commensal communism and the oral cavity.

The world we live in contains unimaginable numbers of bacteria, and these and other single-celled creatures represent the major diversity of life on our planet. During the last decade or so, the complexity and intimacy of the interactions which occur between bacteria and host eukaryotic cells during the process of infection have begun to emerge. The study of such interactions is the subject of the new discipline of cellular microbiology. This intimacy of bacteria/host interactions creates a major paradox. The average human being is 90% bacteria in terms of cell numbers. These bacteria constitute the commensal or normal microflora and populate the mucosal surfaces of the oral cavity, gastrointestinal tract, urogenital tract, and the surface of the skin. In bacterial infections, much of the pathology is due to the release of a range of bacterial components (e.g., modulins such as lipopolysaccharide, peptidoglycan, DNA, molecular chaperones), which induce the synthesis of the local hormone-like molecules known as pro-inflammatory cytokines. However, such components must also be constantly released by the vast numbers of bacteria constituting the normal microflora and, as a consequence, our mucosae should constantly be in a state of inflammation. This is patently not the case, and a hypothesis is forwarded to account for this "commensal paradox", namely, that our commensal bacteria and mucosal surfaces exist in a state of bio-communism, forming a unified "tissue" in which interactions between bacteria and epithelia are finely balanced to ensure bacterial survival and prevent the induction of damaging inflammation. Evidence is emerging that bacteria can produce a variety of proteins which can inhibit the synthesis/release of inflammatory cytokines. The authors predict that such proteins are simply one part of an extensive signaling system which occurs between bacteria and epithelial cells at mucosal surfaces such as those found in the oral cavity.

Bacterial Infections↗
PubMed1998

Use of quality-of-life outcome assessments in current cancer clinical trials.

During the past decade, the importance of integrating quality of life with other indicators of efficacy in cancer clinical trials has been emphasized. This article reviews quality-of-life assessment in clinical trial reports. All empirical studies using patient ratings published in the Journal of Clinical Oncology from 1992 to 1996 were identified. Of these, 59 articles (4%) included quality-of-life assessment, most frequently measured by self-report questionnaires. Most articles reported clinical trials of symptom management or treatment. Future research needs to specify relationships between quality of life, toxicity, and survival. Continued development of this field requires more frequent inclusion of quality of life in clinical studies.

Clinical Trials as Topic↗