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Biomedical subjects

M Young

Publications and source records attributed to M Young.

At least 181 records · Page 10Linked to original sources
PubMed1995

New directions for assessing speech perception in persons with sensory aids.

This study examined the influence of stimulus variability and lexical difficulty on the speech perception performance of adults who used either multichannel cochlear implants or conventional hearing aids. The effects of stimulus variability were examined by comparing word identification in single-talker versus multiple-talker conditions. Lexical effects were assessed by comparing recognition of "easy" words (ie, words that occur frequently and have few phonemically similar words, or neighbors) with "hard" words (ie, words with the opposite lexical characteristics). Word recognition performance was assessed in either closed- or open-set response formats. The results demonstrated that both stimulus variability and lexical difficulty influenced word recognition performance. Identification scores were poorer in the multiple-talker than in the single-talker conditions. Also, scores for lexically "easy" items were better than those for "hard" items. The effects of stimulus variability were not evident when a closed-set response format was employed.

Adult↗
PubMed1995

Histogenesis of papillomas of the nose and paranasal sinuses.

OBJECTIVE: To determine by review of their histogenesis whether papillomas of the nose and paranasal sinuses are three distinct entities or, as has been favored in the literature, three variations of a single entity. METHODS AND PATIENTS: We examined biopsy sections from 191 patients with sinonasal papillomas. Biopsy sections included all types of sinonasal papillomas stained using routine methods and, in some cases, using immunohistochemistry for macrophages (PG-M1) and proliferation antigen (MIB-1). Two cases of inverted papilloma were also examined using transmission electron microscopy. RESULTS: Everted and cylindric cell papillomas are true papillomas, lined by stratified squamous and microcystladen, columnar, oncocytic epithelium, respectively. Inverted papillomas are polyps with marked, patchy squamous metaplasia and numerous microcysts containing macrophages in ductal and surface epithelium. There are no intermediate forms from any one of the three types to another. CONCLUSIONS: Some differences between the three types are already established with regard to sites of origin, tendency to recur, and association with malignancy. It is likely that their etiologies--eg, concerning human papillomavirus infection--will be found to differ, if their distinct histogeneses are considered.

Humans↗
PubMed1995

In-utero cocaine exposure and neonatal intestinal perforation: a case report.

This article describes a case of spontaneous neonatal intestinal perforation in a preterm infant with evidence of intrauterine exposure to cocaine. Clinical, laboratory, radiological, surgical, and pathological finds were inconsistent with necrotizing enterocolitis. Three previous case reports had made the association between spontaneous focal neonatal intestinal perforation and prior intrauterine cocaine exposure; however, in each case, there were extenuating circumstances that may weaken the etiological link. The case described here appears to strengthen the association/etiological link. After all other causes of focal neonatal intestinal perforation have been excluded, the possibility of intrauterine exposure to cocaine should be considered.

Adult↗
PubMed1994

Why do people sue doctors? A study of patients and relatives taking legal action.

To examine the reasons patients and their relatives take legal action, we surveyed 227 patients and relatives who were taking legal action through five firms of plaintiff medical negligence solicitors. Over 70% of respondents were seriously affected by incidents that gave rise to litigation with long-term effects on work, social life, and family relationships. Intense emotions were aroused and continued to be felt for a long time. The decision to take legal action was determined not only by the original injury, but also by insensitive handling and poor communication after the original incident. Where explanations were given, less than 15% were considered satisfactory. Four main themes emerged from the analysis of reasons for litigation: concern with standards of care--both patients and relatives wanted to prevent similar incidents in the future; the need for an explanation--to know how the injury happened and why; compensation--for actual losses, pain and suffering or to provide care in the future for an injured person; and accountability--a belief that the staff or organisation should have to account for their actions. Patients taking legal action wanted greater honesty, an appreciation of the severity of the trauma they had suffered, and assurances that lessons had been learnt from their experiences. A no-fault compensation system, however well intended, would not address all patients' concerns. If litigation is viewed solely as a legal and financial problem, many fundamental issues will not be addressed or resolved.

Adolescent↗
PubMed1994

Gene for familial psoriasis susceptibility mapped to the distal end of human chromosome 17q.

A gene involved in psoriasis susceptibility was localized to the distal region of human chromosome 17q as a result of a genome-wide linkage analysis with polymorphic microsatellites and eight multiply affected psoriasis kindreds. In the family which showed the strongest evidence for linkage, the recombination fraction between a psoriasis susceptibility locus and D17S784 was 0.04 with a maximum two-point lod score of 5.33. There was also evidence for genetic heterogeneity and although none of the linked families showed any association with HLA-Cw6, two unlinked families showed weak levels of association. This study demonstrates that in some families, psoriasis susceptibility is due to variation at a single major genetic locus other than the human lymphocyte antigen locus.

Alleles↗
PubMed1994

Physicians' implementation of dietitians' recommendations: a study of the effectiveness of dietitians.

OBJECTIVE: To determine how often dietitians' recommendations were implemented by physicians and to identify workplace and demographic factors that correlated with successful implementation of recommendations. DESIGN: A cohort of hospitals was surveyed by mail. Dietitians recorded recommendations written in five consecutive medical record entries and sent them to the chief clinical dietitian. Seventy-two hours later, physicians' order sheets were reviewed to assess implementation. Dietitians completed demographic questionnaires. SUBJECTS: Forty-four general hospitals in Philadelphia and the surrounding area were surveyed. To ensure similar standards of nutrition care, only hospitals approved by the Joint Commission on Accreditation of Healthcare Organizations were selected. STATISTICAL ANALYSIS PERFORMED: chi 2, Fisher's exact test, and the Kruskall-Wallis test were used to correlate demographic variables with implementation rate. MAIN OUTCOME MEASURE: Implementation of the dietitians' recommendations by physicians' orders. RESULTS: Responses were obtained from 35 of the 44 hospitals and 98 (70%) of the clinical dietitians. Of the 865 recommendations, 42% were implemented. Significantly higher implementation rates were noted for recommendations solicited by (50%) or discussed with the physician (65%). Dietitians were more successful in teaching hospitals and when they reported to a hospital-operated foodservice rather than a contract foodservice. Success correlated with a lower workload when measured by the ratio of admissions to staff but not when measured by the ratio of beds to staff. CONCLUSIONS: Dietitians could have a greater effect on nutrition care by discussing recommendations with physicians. Further research is needed about staffing formulas and methods to improve the effectiveness of dietitians.

Adult↗
PubMed1994

Detection of human androgen receptor mRNA expression abnormalities by competitive PCR.

A competitive polymerase chain reaction (PCR) method for analysis of androgen receptor (AR) mRNA expression is described. The technique involves the use of an in vitro-transcribed RNA (cRNA) corresponding to a region of the AR mRNA transcript as a competitor in reverse transcription and PCR (RT-PCR) using total cellular RNA. The competitor RNA contains a site-directed mutation that produces a restriction fragment length polymorphism after RT-PCR and endonuclease digestion. We demonstrate that incorporation of the competitor RNA into RT-PCR reactions allows rapid semiquantitative determination of relative AR mRNA levels without the necessity of following PCR product formation kinetically; reaction products are assessed at the conclusion of the reaction sequence and without the use of radioactive probes or other specialized detection systems. We have used competitive PCR to demonstrate low levels of AR mRNA in an androgen-unresponsive human prostate cell line (PC3). In addition, we have also used this method to confirm that genital fibroblasts obtained from a subject with penoscrotal hypospadias (a non-intersex masculinization defect) that exhibit low levels of high-affinity androgen binding also exhibit abnormally low AR mRNA levels. These last results suggest that some non-intersex malformations of the urogenital tract are associated with abnormalities in the expression of the androgen receptor.

Base Sequence↗
PubMed1994

Factor VIII gene inversions causing severe hemophilia A originate almost exclusively in male germ cells.

The factor VIII gene, which is defective in hemophilia A, is located in the last megabase of the long arm of the X chromosome. Inversions due to intrachromosomal homologous recombination between mispaired copies of gene A located within intron 22 of the gene and about 500 kb telomeric to it account for nearly half of all cases of severe hemophilia A. We hypothesized that pairing of Xq with its homolog inhibits the inversion process, and that, therefore, the event originates predominantly in male germ cells. In all 20 informative cases in which the inversion originated in a maternal grandparent, DNA polymorphism analysis determined that it occurred in the male germline. In addition, all but one of 50 mothers of sporadic cases due to an inversion were carriers. Thus, these data support the hypothesis and indicate that factor VIII gene inversions leading to severe hemophilia A occur almost exclusively in male germ cells.

Blotting, Southern↗
PubMed1994

Eosinophilic granuloma of the eyelid.

A 15-year-old girl presented with a left lower eyelid tumor consistent with a nonresolving chalazion. The specimen was biopsied. Histopathologic examination revealed eosinophilic granuloma, an entity that rarely presents on the eyelid. The histopathologic features of eosinophilic granuloma--a member of the histiocytosis X group of diseases--are reviewed. Our patient responded well to incisional biopsy and has required no additional treatment.

Adolescent↗
PubMed1994

Analysis of Bacillus subtilis tag gene expression using transcriptional fusions.

Five of the genes known to encode the synthesis of poly(glycerol phosphate), the major teichoic acid of Bacillus subtilis 168, are organized in two divergently transcribed operons (a divergon), denoted tagAB and tagDEF. To monitor their expression, the 399 bp intergenic region separating the first structural genes of these operons was fused, in both orientations, to a lacZ reporter gene, allowing measurement of promoter activity under specific physiological conditions. Under all experimental conditions, tagA and tagD appeared coordinately expressed, the level of tagD being always higher than that of tagA. No influence of the chromosomal context was observed. Phosphate limitation was accompanied by reduced tag gene expression. Following the onset of sporulation, expression of tag genes diminished rapidly and was essentially abolished by stage II. During germination, the activity of tag genes was detectable before the rise in culture turbidity associated with spore outgrowth. In contrast to tagC (dinC), the expression of which is DNA-damage-inducible, the induction of SOS functions had no effect on tagA and tagD gene expression. The biological significance of these results is discussed.

Bacillus subtilis↗
PubMed1994

Characterization of spo0A homologues in diverse Bacillus and Clostridium species identifies a probable DNA-binding domain.

Spo0A is a phosphorylation-activated transcription factor of Bacillus subtilis. It is a member of the response regulator superfamily of bacterial signal transduction proteins and controls many of the changes in gene expression that occur during the transition into stationary phase and during the initiation of sporulation. To identify the domains of Spo0A most critical for determining its structural and functional features, presumptive homologues of the spo0A gene were characterized in a collection of eight Bacillus species and six Clostridium species representing phylogenetically diverse members of these genera. An alignment of the partial or complete DNA sequences of these homologues revealed three regions of especially high conservation in the effector domain. We speculate that the most highly conserved of these corresponds to the recognition helix of a putative helix-turn-helix motif, and, therefore, represents the actual DNA-containing surface of the protein. In the case of homologues identified in Bacillus anthracis and Clostridium acetobutylicum and retrieved by polymerase chain reaction amplification, we confirmed by gene-disruption analysis that the homologue actually is required for initiation of sporulation. Apparent homologues of the B. subtilis spoIVB gene were also discovered immediately upstream from the spo0A homologues in all Bacillus and Clostridium species examined. The discovery of homologues of B. subtilis sporulation genes in these diverse species implies that the gene products required for specifying pathways of sporulation-specific gene activation and for determining key morphogenetic changes may be highly conserved and suggests that an approach similar to that undertaken here might be used as a general strategy to retrieve and compare their gene sequences. Exhaustive efforts to detect a spo0A-like gene in non-endospore formers, including close relatives of Bacillus such as Listeria and Staphylococcus, were uniformly unsuccessful, suggesting that regulation of gene activity during the transition into stationary phase mediated by Spo0A-like proteins may be exclusive to the endospore-forming bacteria.

Amino Acid Sequence↗
PubMed1994

Potential Role of Elicitins in the Interaction between Phytophthora Species and Tobacco.

The potential role of extracellular elicitor proteins (elicitins) from Phytophthora species as avirulence factors in the interaction between Phytophthora and tobacco was examined. A survey of 85 Phytophthora isolates representing 14 species indicated that production of elicitin is almost ubiquitous except for isolates of Phytophthora parasitica from tobacco. The production of elicitins by isolates of P. parasitica correlated without exception with low or no virulence on tobacco. Genetic analysis was conducted by using a cross between two isolates of P. parasitica, segregating for production of elicitin and virulence on tobacco. Virulence assays of the progeny on tobacco confirmed the correlation between production of elicitin and low virulence.

Journal Article↗
PubMed1994

Antiviral activity of human immunodeficiency virus type 1 protease inhibitors in a single cycle of infection: evidence for a role of protease in the early phase.

The antiviral activities of two substrate-based inhibitors of human immunodeficiency virus type 1 (HIV-1) protease, UK-88,947 and Ro 31-8959, were studied in acute infections. H9 and HeLaCD4-LTR/beta-gal cells were infected either with HIV-1IIIB or a replication-defective virus, HIV-gpt(HXB-2). Both inhibitors were capable of blocking early steps of HIV-1 replication if added to cells prior to infection. Partial inhibition was also obtained by addition of inhibitor at the time of or as late as 15 min after infection. The inhibitors were ineffective if added 30 min postinfection. The inhibitory effects were studied by cDNA analysis with PCR followed by Southern blot hybridization and by infectivity assays allowing quantitation of HIV-1 in a single cycle of replication. When UK-88,947-treated H9 cells were coinfected with HIV-1 and human T-cell leukemia virus type I only the replication of HIV-1 was inhibited, demonstrating viral specificity. Pretreating the infectious virus stocks with the inhibitors also prevented replication, indicating that the inhibitors block the action of the viral protease and not a cellular protease. A panel of primer sets was used to analyze cDNA from cell lysates by PCR amplification at 4 and 18 h postinfection. Four hours after infection, viral specific cDNA was detected with all of the four primer pairs used: R/U5, nef/U3, 5' gag, and long terminal repeat (LTR)/gag. However, after 18 h, only the R/U5 and nef/U3 primer pairs and not the 5' gag or LTR/gag primer pair were able to allow amplification of cDNA. The results suggest a crucial role of HIV-1 protease in the early phase of viral replication. Although it is not clear what early steps are affected by the protease, it is likely that the target is the NC protein, as referred from our previous reports of the in situ cleavage of the nucleocapsid (NC) protein by the viral protease inside lentiviral capsids. The results suggest that it is not the inhibition of initiation and progression of reverse transcription but the stability of full-size unintegrated cDNA which is affected in the presence of protease inhibitors. Alternatively, the cleavage of the NC protein may be required for the proper formation of preintegration complex and/or for its transport to the nucleus.

Base Sequence↗
PubMed1994

Mineralocorticoids, hypertension, and cardiac fibrosis.

Uninephrectomized rats drinking 1% sodium chloride were given aldosterone (Aldo, 0.75 microgram/h, subcutaneous [s.c.] infusion), deoxycorticosterone (DOC, 20 mg/wk, s.c.), corticosterone (B, 2 mg/d, s.c.), or the antiglucocorticoid-antiprogestin RU486 (2 mg/d, s.c.) for 8 wk, and hemodynamic and tissue responses were compared with a non-steroid-treated control group. Aldo and DOC markedly increased systolic BP and caused considerable (40-50%) cardiac hypertrophy; B and RU486 caused neither hypertension nor cardiac hypertrophy. Measurements of ventricular cross-sectional areas showed hypertrophy due to an increase in mass of the left ventricle only. Cardiac hydroxyproline concentration was increased considerably by Aldo and DOC, to a lesser degree by RU486, and not by B. Aldo markedly elevated left ventricular interstitial collagen (2.5-fold vs control, P < 0.01 vs all groups); other steroid treatments also increased interstitial collagen over control (DOC x 1.8-, RU486 x 1.6-, B x 1.3-fold), with identical responses for right and left ventricles (r = 0.94). A different pattern of perivascular fibrosis was noted; DOC elevated perivascular collagen (2.1-fold vs control, P < 0.01 vs all other groups); RU486 raised levels 1.4-fold vs control, but neither Aldo nor B significantly affected perivascular collagen. These data are consistent with interstitial cardiac fibrosis reflecting type I (mineralocorticoid) receptor occupancy by administered Aldo or DOC, or by elevated endogenous B after type II (glucocorticoid) receptor blockade after RU486 administration; perivascular fibrosis may reflect a composite response after type I receptor agonist/type II glucocorticoid receptor antagonist occupancy.

Aldosterone↗
PubMed1994

Relations of exercise to body image and sexual desirability among a sample of university students.

College students (N = 212) completed a survey designed to elicit information about their exercise habits, perceived sexual desirability, and body image. A number of body-image items were associated with both perceived physical attractiveness and perceived sexual desirability. Total body image was related to gender, exercise level, perceived physical attractiveness, perceived sexual desirability, and perception of self as a sexual partner.

Adolescent↗
PubMed1994

Effect of intrauterine cocaine exposure on respiratory distress syndrome in very low birthweight infants.

To evaluate the effect of intrauterine cocaine exposure on lung maturity of very low birthweight infants, the medical records of all infants with birthweight < 1500 g born between January 1989 and December 1990 at DC General Hospital were reviewed. Infants with conditions known to cause lung maturity, severe congenital anomalies, proven early sepsis, and birthweight > or = 500 g were excluded. A total of 69 infants were included in the study. Chest roentgenograms of these infants were evaluated by a pediatric radiologist, who was unaware of the infant's medical course, for evidence of respiratory distress syndrome (RDS), and radiological findings were correlated with clinical signs. Forty infants were exposed to cocaine in utero (cocaine group) and 29 were not exposed (noncocaine group). African-American ethnicity, pregnancy-induced hypertension, prolonged rupture of membranes, and alcohol use were similar in both groups. Tobacco use among cocaine group mothers was higher (42.5% versus 13.8%; P = .01). Gestational age (28.3 +/- 2.8 versus 28.3 +/- 3 weeks), birthweight (966 +/- 282 versus 1059 +/- 295 g), male gender, and Apgar scores were similar in both groups. Thirty (75%) infants in the cocaine group developed RDS compared with 19 (66%) in the noncocaine group (P > .05). Using multiple logistic regression analysis and controlling for smoking, alcohol use, and prolonged rupture of membranes (24 to 72 hours), the incidence of RDS between the groups remained statistically insignificant. We conclude that intrauterine cocaine exposure does not alter the incidence of RDS in very low birthweight infants.

Cocaine↗