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Biomedical subjects

S Taylor

Publications and source records attributed to S Taylor.

At least 523 records · Page 29Linked to original sources
PubMedDate not supplied

Proliferation of epithelia of noninvolved mucosa in patients with head and neck cancer.

BACKGROUND: Morphologically noninvolved mucosa in patients with head and neck cancer is altered by carcinogens. These alterations may include chromosome alterations, gene mutations, and other molecular abnormalities which may explain very high incidence of second tumors in this group of patients. The purpose of this study was to investigate the in vivo proliferative characteristics in epithelial tissues adjacent to the tumor in a series of patients with head and neck cancer. METHODS: Twenty-one patients with head and neck tumors received IV infusions of iododeoxyuridine (IdUrd) and/or bromodeoxyuridine (BrdUrd). Surgical specimens containing normal-appearing epithelium adjacent to the tumor were selected and stained with the respective monoclonal antibody. The percentage of S-phase cells (labeling index, LI) was counted in the basal and suprabasal layers of the epithelium. RESULTS: In 27 samples of oral epithelium obtained from 14 previously untreated patients, labeled (S-phase) cells were predominantly located in suprabasal layers with LI 31.6 +/- 3.1% (range 13.5-73.2%). In contrast, the LI of the basal layer was very low: 1.6 +/- 0.2% (range 0.5%-8.8%). There was no statistically significant difference between normal appearing and dysplastic samples (p > 0.05). In 10 samples obtained from 7 patients whose biopsies were studied 2 days to 2 month after concomitant radiation and chemotherapy, the LI of the oral mucosa basal layer was significantly higher (21.0 +/- 4.1%, range 6.3-39.2%). The LI of the suprabasal layer in treated patients was 14.3 +/- 2.4% (range 5.9-31.1%). The LI of nasal pseudostratified epithelium (4 samples) was 11.2%. The average LI of "basal" cells was 8.3% (range 5.9-11.9%) and that of "suprabasal" cells was 13.8% range (3.2-29.5%). The basal layer of the skin (5 samples) contained 9.3% labeled cells (range 3.3-16.3%); the LI of suprabasal layers of skin was 21.3% (range 7.8-33.2%). CONCLUSION: Both the frequency and the spatial distribution of S-phase cells are disordered in noninvolved epithelia in patients with head and neck tumors. These observations suggest that disordered proliferation may be an early consequence of field cancerization, a consequence that occurs prior to appearance of morphologically apparent hyperplasia or dysplasia.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Incidence and impact of resistance against approved antiretroviral drugs.

More than 15 antiretroviral drugs are now available for clinical use, and have led to significant reductions in morbidity and mortality for HIV infected individuals. Nevertheless, antiviral drug resistance emerges to all these drugs, which limits their benefit. This review addresses the biological basis of antiretroviral drug resistance, and the prevalence of specific drug resistance associated mutations in patients treated with the three currently available classes of agents, namely nucleoside analogue reverse transcriptase inhibitors, non nucleoside reverse transcriptase inhibitors and protease inhibitors. In addition, data on prevalence of HIV drug resistance in untreated individuals published to date are summarised, and the implications of potential transmission of drug resistant HIV is discussed.

Anti-HIV Agents↗
PubMedDate not supplied

Phase II trial of echinomycin for the treatment of advanced renal cell carcinoma. A Southwest Oncology Group study.

Forty-nine patients with metastatic or recurrent renal cell carcinoma were treated on a phase II trial of Echinomycin. Treatment consisted of Echinomycin 1.25 mg/m2 intravenously every 28 days. Among the 47 evaluable patients there were no complete responses and only one partial response for an overall response rate of 2% (95% confidence interval, 0-11%). Eighteen patients (38%) experienced toxicity of grade 3 or worse. The most common toxicities were nausea and vomiting. The results of this study indicate that Echinomycin is not sufficiently active to warrant further trials for the treatment of renal cell carcinoma.

Adult↗
PubMedDate not supplied

Local recurrence and survival among black women with early-stage breast cancer treated with breast-conservation therapy or mastectomy.

BACKGROUND: Black women with breast cancer have significantly worse survival rates and receive diagnoses at relatively younger ages, compared with white patients with breast cancer, in the United States. Young age at diagnosis has been associated with increased risk for local recurrence (LR) after breast-conservation therapy (BCT). The goal of this study was to evaluate the impact of age and BCT on LR and survival rates among black patients with breast cancer. METHODS: The records for 363 black women treated for breast cancer (excluding stage IV disease) at a comprehensive cancer center were reviewed. RESULTS: Fifty-eight percent of patients (n = 211) had tumors < or = 5 cm in diameter. Forty-two of these patients (19.9%) received BCT; the LR rate for this group was 9.8%. A total of 168 patients (79.6%) underwent mastectomy; the LR rate for this group was 8.9%. Data on the primary operation were unavailable for one patient. Five-year disease-free survival rates were similar for patients treated with BCT and those treated with mastectomy (88% and 73%, respectively). LR was associated with significant decreases in 5-year overall survival rates for both the BCT group (67% vs. 95%, P < .01) and the mastectomy group (43% vs. 76%, P < .01). LR and 5-year disease-specific survival rates were similar for patients <50 years of age and patients > or = 50 years of age, regardless of treatment. CONCLUSIONS: LR and survival rates are not compromised by the use of BCT among black American patients. LR is associated with an increased risk of breast cancer death, regardless of treatment type. Younger age at diagnosis was not associated with an increased rate of LR after BCT in this series.

Adolescent↗
PubMedDate not supplied

Morphine and human aggression.

Twenty-eight male undergraduates received either 45 mg of immediate-release oral morphine tablets or a placebo. Subjects were then given the opportunity to administer electric shocks to an increasingly aggressive bogus opponent during a competitive reaction-time task. Subjects in the morphine condition were more willing to initiate attacks against their opponent than subjects in the placebo condition, and reacted more aggressively at all levels of provocation.

Adolescent↗
PubMedDate not supplied

The fear of healthy eating: understanding the paranoia.

Scientific research continues to point to the health benefits of including more fruits and vegetables in the diet. At the same time, some groups claim that pesticides used in their production pose significant health risks. This article reviews some of the position statements, describes the principles of risk and hazard assessment, and identifies regulatory processes to assure the safe use of pesticides.

Attitude to Health↗
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Efficacy of virtual reality exposure therapy to treat driving phobia: a case report.

An AB case design was used to examine the efficacy of virtual reality exposure therapy (VRET) in treating driving phobia. After a one week baseline, the patient received three treatment sessions over a ten day period. Treatment included practice of four VR driving scenarios. Peak anxiety decreased within and across sessions. Ratings of anxiety and avoidance declined from pre-treatment and post-treatment, with gains maintained at seven month followup. Phobia-related interference in daily functioning similarly decreased. The results suggest that it would be useful to further evaluate the efficacy of VRET for driving phobia in controlled clinical trials.

Adult↗
PubMedDate not supplied

Psychopathological correlates of anxiety sensitivity: evidence from clinical interviews and self-report measures.

Most research on anxiety sensitivity (AS) and its relation to psychopathology has examined the Anxiety Sensitivity Index (ASI) in various clinical samples. The present study was the first to investigate psychopathological correlates of AS using self-report measures, the anxiety, somatoform, and substance use disorders sections of the Structured Clinical Interview for the DSM-IV (SCID), and open-ended interview questions about the subjective meaning and origins of AS. A college student sample (N=317) was used for the correlational analysis, and subsamples of high-AS (n=44) and low-AS (n=41) participants completed the interviews. Despite having an ASI score (Mean=35.0) that was equivalent to that observed in panic disorder samples, the screening questions in the clinical interview indicated that only 55% of high-AS participants had panic attacks and the diagnostic assessment indicated that only 30% met criteria for an anxiety disorder. Several findings suggested that AS, at least as measured by the ASI, was strongly related to anxiety disorder symptoms and diagnoses, although there was substantial variation within the anxiety disorder classifications. There was also evidence that AS might extend to a broader catastrophic style concerning bodily symptoms and health that go beyond anxiety symptoms per se. The subjective meaning of AS derived from the interview data stressed the need for a formal, structured interview of AS.

Adult↗
PubMedDate not supplied

Gender differences in dimensions of anxiety sensitivity.

Anxiety sensitivity (AS) is the fear of anxiety-related sensations arising from beliefs that these sensations have harmful physical, psychological, or social consequences. AS is measured using the Anxiety Sensitivity Index (ASI), a 16-item self-report questionnaire. Little is known about the origins of AS, although social learning experiences (including sex-role socialization experiences) may be important. The present study examined whether there were gender differences in: (a) the lower- or higher-order factor structure of the ASI; and/or (b) pattern of ASI factor scores. The ASI was completed by 818 university students (290 males; 528 females). Separate principal components analyses on the ASI items of the total sample, males, and females revealed nearly identical lower-order three-factor structures for all groups, with factors pertaining to fears about the anticipated (a) physical, (b) psychological, and (c) social consequences of anxiety. Separate principal components analyses on the lower-order factor scores of the three samples revealed similar unidimensional higher-order solutions for all groups. Gender x AS dimension analyses on ASI lower-order factor scores showed that: females scored higher than males only on the physical concerns factor; females scored higher on the physical concerns factor relative to their scores on the social and psychological concerns factors; and males scored higher on the social and psychological concerns factors relative to their scores on the physical concerns factor. Finally, females scored higher than males on the higher-order factor representing the global AS construct. The present study provides further support for the empirical distinction of the three lower-order dimensions of AS, and additional evidence for the theoretical hierarchical structure of the ASI. Results also suggest that males and females differ on these various AS dimensions in ways consistent with sex role socialization practices.

Adolescent↗
PubMedDate not supplied

An expanded anxiety sensitivity index: evidence for a hierarchic structure in a clinical sample.

Anxiety sensitivity (AS) is the fear of anxiety-related sensations. According to Reiss's (e.g., Reiss, 1991) expectancy theory, AS amplifies fear and anxiety reactions, and plays an important role in the etiology and maintenance of anxiety disorders, particularly panic disorder. Recent evidence suggests that AS has a hierarchical structure, consisting of multiple lower order factors, loading on a single higher order factor. If each factor corresponds to a discrete mechanism (Cattell, 1978), then the results suggest that AS arises from a hierarchic arrangement of mechanisms. A problem with previous studies is that they were based on the 16-item Anxiety Sensitivity Index, which may not contain enough items to reveal the type and number of lower order factors. Also, some of the original ASI items are too general to assess specific, lower order factors. Accordingly, we developed an expanded measure of AS--the ASI-R--which consists of 36 items with subscales assessing each of the major domains of AS suggested by previous studies. The ASI-R was completed by 155 psychiatric outpatients. Factor analyses indicated a four-factor hierarchical solution, consisting of four lower order factors, loading on a single higher factor. The lower order factors were: (1) fear of respiratory symptoms, (2) fear of publicly observable anxiety reactions, (3) fear of cardiovascular symptoms, and (4) fear of cognitive dyscontrol. Each factor was correlated with measures of anxiety and depression, and fear of cognitive dyscontrol was most highly correlated with depression, which is broadly consistent with previous research. At pretreatment, patients with panic disorder tended to scored highest on each of the factors, compared to patients with other anxiety disorders and those with nonanxiety disorders. These findings offer further evidence that Reiss's expectancy theory would benefit from revision, to incorporate the notion of a hierarchic structure of AS.

Adult↗
PubMedDate not supplied

Educational intervention strategies for children with visual impairments with emphasis on retinopathy of prematurity.

Young children with retinopathy of prematurity have many intervention needs. This article discusses the possible causes of retinopathy of prematurity and possible educational problems experienced by these children. In addition, possible intervention strategies are suggested in the areas of language development, social interaction, self-help skills, orientation and mobility, and educational technology as they relate to the needs of young children with retinopathy of prematurity.

Child↗
PubMedDate not supplied

Identification of a diversity segment of human T-cell receptor beta-chain, and comparison with the analogous murine element.

The humoral immune system antigen-binding proteins (immunoglobulins) are disulphide-linked heterodimers of light and heavy chains. The gene for the variable region which determines antigen specificity is assembled when one member from each of the dispersed clusters of variable (V) gene segments, diversity (D) elements (for the heavy chains only) and joining (J) segments rearrange and fuse during B-cell development (reviewed in ref. 1). Short recognition sequences adjacent to these elements appear to be involved in the recombination process. The cellular immune system antigen recognition proteins are receptors on the surface of T cells, which are composed of disulphide-linked alpha-chains and beta-chains, each of which has a variable and constant region. Recently, cDNA clones of the beta-chain mRNA have been isolated; the genomic arrangement is very similar to immunoglobulin genes with multiple V beta genes, and two clusters of J beta segments, each of which is upstream from a constant-region gene segment. The V beta and J beta segments have adjacent recombinational recognition sequences like the immunoglobulin elements. However, approximately 10 nucleotides of the cDNA clones between the V beta and J beta regions were not present in the corresponding genomic elements and may have been due to intervening D beta segments. Here we describe a diversity element (D beta 1.1) in a region of high human-mouse homology about 650 bases 5' to the first J beta cluster. Two transcripts which include sequences upstream of D beta 1.1 are found in the human thymus. This region may have some other function besides providing the beta-chain with a diversity segment.

Amino Acid Sequence↗
PubMedDate not supplied

Organization and sequences of the variable, joining and constant region genes of the human T-cell receptor alpha-chain.

An essential property of the immune system is its ability to generate great diversity in antibody and T-cell immune responses. The genetic and molecular mechanisms responsible for the generation of antibody diversity have been investigated during the past several years. The gene for the variable (V) region, which determines antigen specificity, is assembled when one member of each of the dispersed clusters of V gene segments, diversity (D) elements (for heavy chains only) and joining (J) segments are fused by DNA rearrangement. The cloning of the beta-chain of the T-cell antigen receptor revealed that the organization of the beta-chain locus, which is similar to that of immunoglobulin genes, is also composed of noncontiguous segments of V, D, J and constant (C) region genes. The structure of the alpha-chain seems to consist of a V and a C domain connected by a J segment. We report here that the human T-cell receptor alpha-chain gene consists of a number of noncontiguous V and J gene segments and a C region gene. The V region gene segment is interrupted by a single intron, whereas the C region contains four exons. The J segments, situated 5' of the C region gene, are dispersed over a distance of at least 35 kilobases (kb). Signal sequences, which are presumably involved in DNA recombination, are found next to the V and J gene segments.

Amino Acid Sequence↗
PubMedDate not supplied

Effects of vasoactive intestinal peptide on human sperm motility.

Sperm flagellar activity is modulated by cAMP. In target tissues, vasoactive intestinal peptide (VIP) stimulates adenyl cyclase activity, which elevates intracellular cAMP levels and activates protein kinase activity. This study investigated the effects of VIP on motility of sperm from 17 subjects. Motile activities, monitored before (0 min, baseline) and for 40 min after incubation with VIP (0.2 microgram/mL cell suspension), were analyzed by computer-assisted semen analysis. The data (mean +/- SEM) are expressed as percentages of baseline values and changes were compared by trend analysis for interval level measures by repeated measures analysis of variance orthogonal polynominal contrasts. The addition of VIP significantly increased motile sperm concentration (110 +/- 17% [10 min], 132 +/- 15% [20 min], 152 +/- 18% [30 min], 125 +/- 18% [40 min]; p < .02) and sperm with rapid straight-line motility (V > 25 microns/s) (167 +/- 20%, 174 +/- 19%, 173 +/- 23%, 141 +/- 16%; p < .02). Mean track speed (micron/s) was increased (125 +/- 12%, 134 = 9%, 129 +/- 12% and 126 +/- 12%; p < .02), while mean progressive velocity, amplitude of head displacement, and beat frequency were not affected by VIP. These results indicate that VIP stimulates sperm motile activity by cAMP-mediated phosphorylation of axonemal proteins.

Adenylyl Cyclases↗