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Biomedical subjects

M A Drake

Publications and source records attributed to M A Drake.

At least 37 records · Page 2Linked to original sources
PubMed2002

[Language abnormalities in patients with multiple sclerosis].

BACKGROUND: Patients suffering from multiple sclerosis (MS) have a high frequency of cognitive deficits. Research has demonstrated impairments in memory, attention, information-processing speed, and executive functions. Although it has been traditionally held that language function is commonly preserved in MS, some studies have demonstrated language impairment in these patients, particularly in tasks of naming and word-generation. OBJECTIVES: The aim of the study was to examine language functioning in MS, with particular interest in naming ability and verbal fluency. MATERIAL AND METHODS: Thirty patients with MS, and 30 neurologically intact normal controls, matched for age and educational level were evaluated. As part of a wider neuropsychological evaluation, all subjects were administered the Boston Naming Tests. To compare performances, a comprehensive classification of error types was devised. RESULTS: MS patients showed significantly lower performance on both linguistic measures than the control subjects. On the Boston Naming Test, MS patients obtained significant lower scores than controls, with a high rate of semantic errors. Additionally, they tended to show an also high number of visuoperceptual errors. Low scores on naming task correlated with low performance on verbal fluency. CONCLUSIONS: This study reveals that language function can be impaired in MS, and that naming difficulties are a frequent finding. This naming deficit seems to have a double origin, stemming from disruption at the levels of the perceptual and/or the semantic systems.

Adult↗
PubMed2001

Aroma-active components of nonfat dry milk.

Application of aroma extract dilution analysis (AEDA) on the volatile components of low-, medium-, and high-heat-treated nonfat dry milks (NDM) revealed aroma-active compounds in the log(3) flavor dilution (log(3) FD) factor range of 1 to 6. The following compounds contributed the highest log(3) FD factors to overall NDM flavor: 2,5-dimethyl-4-hydroxy-3(2H)-furanone [(Furaneol), burnt sugar-like]; butanoic acid (rancid); 3-(methylthio)propanal [(methional), boiled potato-like]; o-aminoacetophenone (grape-like); delta-decalactone (sweet); (E)-4,5-epoxy-(E)-2-decenal (metallic); pentanoic acid (sweaty); 4,5-dimethyl-3-hydroxy-2(5H)-furanone [(sotolon), curry]; 3-methoxy-4-hydroxybenzaldehyde [(vanillin), vanilla]; 2-acetyl-1-pyrroline and 2-acetyl-2-thiazoline (popcorn-like); hexanoic acid (vinegar-like); phenylacetic acid (rose-like); octanoic acid (waxy); nonanal (fatty); and 1-octen-3-one (mushroom-like). The odor intensities of Furaneol, butanoic acid, methional, o-aminoacetophenone, sotolon, vanillin, (E)-4,5-epoxy-(E)-2-decenal, and phenylacetic acid were higher in high-heat-treated samples than others. However, the odor intensities of lactones, 2-acetyl-1-pyrroline, and 2-acetyl-2-thiazoline were not affected by heat treatment. Sensory evaluation results also revealed that heat-generated flavors have a major impact on the flavor profile of NDM.

Animals↗
PubMed2001

Characteristic aroma components of British Farmhouse Cheddar cheese.

Aroma components responsible for aroma typical of British Farmhouse Cheddar cheese were studied by aroma extract dilution analysis. Cheese extracts were prepared by direct solvent extraction, high-vacuum transfer, and class fractionation. Most aroma-active components of acidic and neutral/basic fractions have been previously associated with Cheddar cheese flavor. p-Cresol was mainly responsible for a "cowy-barny" note, whereas an intense "soil-like" note was due to 2-isopropyl-3-methoxypyrazine. At much lower odor intensity, 2-isobutyl-3-methoxypyrazine contributed a "bell pepper-like" note. Additionally, within the same wedge of cheese, the concentrations of p-cresol and 2-isopropyl-3-methoxypyrazine were lower at the narrow end (center) than at the rind side. Direct addition of p-cresol (> or =100 ppb) or 2-isopropyl-3-methoxypyrazine (> or =3 ppb) in a mild domestic Cheddar cheese resulted in increases in intensities of cowy/phenolic and earthy/bell pepper aroma notes.

Animals↗
PubMed2001

Development of a quantitative competitive PCR assay for detection and quantification of Escherichia coli O157:H7 cells.

A quantitative competitive PCR (QC-PCR) assay was developed to detect and quantify Escherichia coli O157:H7 cells. From 10(3) to 10(8) CFU of E. coli O157:H7 cells/ml was quantified in broth or skim milk, and cell densities predicted by QC-PCR were highly related to viable cell counts (r(2) = 0.99 and 0.93, respectively). QC-PCR has potential for quantitative detection of pathogenic bacteria in foods.

Animals↗
PubMed2001

Influence of adjunct cultures on ripening of reduced fat Edam cheeses.

The influence of four adjunct cultures [Brevibacterium linens (BL2), Lactococcus lactis ssp. diacetylactis, Lactobacillus helveticus (LH212), and Lactobacillus reuteri (ATCC 23272)] on chemical and sensory characteristics of reduced fat Edam cheese was studied. The aminopeptidase activity of Lactococcus lactis ssp. diacetylactis was higher than that of Lactobacillus helveticus, Lactobacillus reuteri, and Brevibacterium linens, respectively. Mean percent fat and moisture contents of reduced fat cheese were 20.85 +/- 0.69 and 42.95 +/- 0.43, respectively. Percentage of fat and moisture of full fat control cheese were 30.06 +/- 0.78 and 39.11 +/- 0.60. Titratable acidity increased in all cheese with aging while pH initially decreased but increased in cheese after 6 mo aging at 7 degrees C. Lactic acid bacteria counts were on average one log higher for reduced fat cheeses than for full fat control cheese and counts decreasing with aging. Free amino acids (FAA) in cheeses increased with aging, and were higher in reduced fat cheeses than in the full fat control cheese. Reduced fat cheeses containing L. helveticus exhibited the highest FAA content. Descriptive sensory panelists (n = 9) did not detect differences among cheeses after 3 and 6 mo ripening, but aged/developed flavors (fruity, nutty, brothy, sulfur, free fatty acid) and sweetness increased between 3 and 6 mo. Expert panelists (n = 6) detected differences in texture quality among the cheeses. Reduced fat control cheeses and reduced fat cheeses with L. helveticus and L. reuteri received the highest texture quality scores. Addition of L. helveticus and Lc. lactis ssp. diacetylactis, as adjunct cultures to reduced fat Edam cheeses increased proteolysis, while the addition of L. helveticus and L. reuteri increased texture quality of cheeses.

Amino Acids↗
PubMed2001

Acid stress, starvation, and cold stress affect poststress behavior of Escherichia coli O157:H7 and nonpathogenic Escherichia coli.

The effects of acid shock, acid adaptation, starvation, and cold stress of Escherichia coli O157:H7 (ATCC 43895), an rpoS mutant (FRIK 816-3), and nonpathogenic E. coli (ATCC 25922) on poststress heat resistance and freeze-thaw resistance were investigated. Following stress, heat tolerance at 56 degrees C and freeze-thaw resistance at -20 to 21 degrees C were determined. Heat and freeze-thaw resistance of E. coli O157:H7 and nonpathogenic E. coli was enhanced after acid adaptation and starvation. Following cold stress, heat resistance of E. coli O157:H7 and nonpathogenic E. coli was decreased, while freeze-thaw resistance was increased. Heat and freeze-thaw resistance of the rpoS mutant was enhanced only after acid adaptation. Increased or decreased tolerance of acid-adapted, starved, or cold-stressed E. coli O157:H7 cells to heat or freeze-thaw processes should be considered when processing minimally processed or extended shelf-life foods.

Adaptation, Physiological↗
PubMed2000

A comparison of methods for the detection of Escherichia coli O157:H7 from artificially-contaminated dairy products using PCR.

Rapid nucleic acid-based methods to detect human pathogens in foods are dependent on the reliability of the DNA or RNA extraction method used. Skim milk, non-fat dry milk, Cheddar and Brie cheese, and reconstituted whey powder were seeded with serially diluted (10(0)-10(7) cfu 10 ml(-1)) Escherichia coli O157:H7 and subjected to DNA extraction (i) directly from the food product using a solvent-based procedure and (ii) using a guanidinium isothiocyanate (GITC) procedure after previous bacterial concentration. Both the efficiency of DNA extraction and the overall PCR detection limits were evaluated. In almost all instances, the total DNA yield using the solvent method was greater than that obtained for the concentration method. However, the purity of the DNA obtained after bacterial concentration was significantly better than that obtained after organic extraction alone. PCR detection limits after each DNA recovery method varied with the specific food, ranging from 10(1) to 10(4) cfu ml(-1) for all products except whey powder. DNA yields and subsequent PCR detection limits for reconstituted whey powder were extremely poor, and neither procedural changes nor the addition of PCR enhancement agents were able to improve recovery and/or detection. It is concluded that the efficiency of DNA extraction is an extremely important and frequently overlooked variable impacting the overall detection limits of PCR-based detection strategies.

Animals↗
PubMed2000

Downregulation of tyrosinase activity in human melanocyte cell cultures by yohimbine.

Treatment of human melanocyte cell cultures with the alpha-2 adrenergic receptor antagonist yohimbine results in a marked down-regulation of tyrosinase activity. A 30% decrease occurs within 12 h of exposure of cells to yohimbine (100 microM), and by 48 h tyrosinase activity in treated melanocytes is less than a fifth that of control cultures. The inhibition is dose dependent and occurs in human melanocytes derived from either black or white skin types, and also in mouse melanoma cells. The yohimbine-induced decrease in tyrosinase activity is reversible, with enzyme levels returning to 90% of control values 48 h after removal of drug. Although tyrosinase activity is markedly suppressed by yohimbine, the compound has no effect on cell proliferation, cellular translation, or DNA synthesis. Treatment of melanocyte cultures with yohimbine blocks the increase in tyrosinase activity by either 3-isobutyl-1-methylxanthine, dibutyryl cAMP, or forskolin. Results of cAMP immunoassays, show that intracellular levels of the cyclic nucleotide are unaffected in cells treated with yohimbine. Tyrosinase inhibition by yohimbine does not involve a decrease in substrate availability since tyrosine uptake studies show that yohimbine has no effect on the amount of tyrosine entering the cell. Incubation of a melanosome-enriched fraction with yohimbine does not cause a lowering of tyrosinase activity, suggesting that an intact cell is required for yohimbine action. In addition, tyrosinase extracts show no reduction in activity when incubated directly with yohimbine, indicating that the drug does not act as a direct inhibitor of the enzyme. Finally, results of western immunoblotting show that yohimbine does not significantly lower the amount of tyrosinase protein in human melanocytes. These findings suggest that yohimbine acts through an as yet unidentified signaling pathway to lower the catalytic activity of pre-existing tyrosinase molecules present in melanocytes.

Adrenergic Antagonists↗
PubMed2000

Survival of Escherichia coli O157:H7 in buttermilk as affected by contamination point and storage temperature.

The effects of contamination point (during fermentation versus postfermentation) and storage temperature (5 and 12 degrees C) were determined for survival of Escherichia coli O157:H7 in fermented buttermilk. E. coli O157:H7 was recovered from buttermilk inoculated during fermentation for 22 days and in buttermilk inoculated postfermentation for 32 days. For storage temperatures of 5 and 12 degrees C, D-values were lower for E. coli O157:H7 inoculated during fermentation (2.5, 2.2 days) than postfermentation (5.6, 4.8 days) (P < 0.05). Developed acidity in inoculated buttermilks was not different from controls (P > 0.05). The extended recovery of viable enterohemorrhagic E. coli O157:H7 from both processing scenarios indicates that the presence of E. coli O157:H7 in buttermilk is not limited to postprocessing contamination.

Animals↗
PubMed1999

Sharpening the focus on populations: an intentional community health nursing approach. Part II.

An interpretive study conducted in a Midwestern metropolitan area was designed to examine expertise in everyday community health nursing (CHN) practice. Twenty-five nurses from three practice areas (traditional, nontraditional, and program development) participated in group and individual interviews and field observations, sharing stories of their practice. Transcribed interviews and field observation notes were analyzed as a text. One of the major findings of the study focused on experiences of the nurses as they developed the population aspects of their everyday practice. Part I describes the natural development of a population focus of CHN generalists whose care most often targeted individuals and families. The stories of how their practices evolved and were supported by their institutions provided insights into how nurses develop a broad population-focused practice perspective. Part II examines the practice of those CHN specialists who nurse their target populations from an intentional perspective. Their population-focused practice, in which they repeatedly displayed what the research team terms multilingual and multiperspectival skills, was solidly based in their prior individual and family-focused experience and expertise in program planning and evaluation.

Attitude of Health Personnel↗
PubMed1999

Articulating the culture and tradition of community health nursing.

While community health nursing (CHN) leaders speculate about the future, nurses on the front lines care for vulnerable families and populations in the midst of diminishing resources, radical changes in health care delivery systems, and unwieldy bureaucracies. Narrative data from a recent interpretive study provided an unexpected opportunity to explore how CHN practice in diverse settings is evolving in response to such changes. Data consisted of interviews and observations of 25 nurses in their practice setting. Several clinical stories or exemplars are selected to highlight how the "culture" of agency settings shapes public health nursing (PHN) practice in ways that need to be recognized and strengthened or affirmed. Clinical storytelling can play a crucial role in preserving the PHN tradition and restoring and transforming local cultures when PHNs, administrators, educators, and researchers commit to PHN excellence.

Community Health Nursing↗
PubMed1997

The responsive use of self in community health nursing practice.

This interpretive study examined the expertise that is often unrecognized in the everyday practice of community health nurses. Twenty-five nurses participated in the study and were asked to describe meaningful clinical situations during group and individual interviews. Field notes of observations of clinical situations and transcribed interviews were analyzed as a text. A major finding of the study involved the nurse's responsive use of self. Responsiveness to the other enabled the nurse to gain a situated understanding of clients' lives and to cultivate clients' strengths and connections to a responsive community.

Adolescent↗
PubMed1996

Case report: scrotal cellulitis secondary to hot tub exposure.

Inflammatory disorders of the scrotum vary in their presentation and etiology. This may range from relatively minor cutaneous infections to scrotal gangrene. Herein presented is a case of scrotal cellulitis secondary to cutaneous inoculation from a hot tub.

Bacterial Infections↗
PubMed1978

An information service for practicing veterinarians.

Many Indiana veterinarians are relatively isolated from colleagues and information sources. Their information needs cannot be easily met by public or medical libraries. The Veterinary Medical Information Center (VMIC) at Purdue University, which began operation in the fall of 1977, offers information services designed to meet the specific needs of veterinary medical practitioners in the state of Indiana. Questions received by the center have covered all facets of animal medicine and management. After two years of free service, VMIC will begin charging clients for services and will consider expansion of the service to other states. VMIC operations will be evaluated through data collected by the center and follow-up surveys.

Animals↗