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Biomedical subjects

T Murray

Publications and source records attributed to T Murray.

At least 37 records · Page 2Linked to original sources
PubMed1997

Children's affective responses, cognitive appraisals, and coping strategies in response to the negative affect of parents and peers.

Although research has linked difficulties in parent mood functioning to developmental problems in children, little work has examined why such a link occurs. Following current social-cognitive perspectives on children's cognitive appraisals to negative parent affect, it was hypothesized that children would show more intense affective responses, less confidence, and less active coping strategies in response to parent, as opposed to peer, negative affect. In the current study, young children (N = 39) were read experimental vignettes portraying peers and parents in either happy, sad, or angry emotional states. Children were then interviewed about their affective responses, cognitive appraisals, and coping strategies to each vignette. Beyond experiencing more negative affective responses to parent, compared to peer negative affect, children felt they could do little to help themselves when faced with paternal distress and frequently indicated they would engage in avoidant coping strategies (e.g., hiding) to make themselves feel better when confronted with parent sadness. This study has implications for more industrious future research, as well as intervention projects that involve assisting children who live in households marked by high levels of negative adult affect.

Adaptation, Psychological↗
PubMed1997

Liposomal distribution in malignant glioma: possibilities for therapy.

We investigated the potential of 111In-labelled liposomes to specifically target recurrent high-grade glioma in eight patients, all of whom had clinical and radiological evidence of relapse following prior treatment with surgery and radiotherapy. The phospholipid liposomes were labelled with 74 MBq 111In and injected intravenously. The distribution of radioactive material in the brain was imaged using a dedicated neuro-SPET imager. Images were taken 1 h post-injection and repeated at 24, 48 and 72 h. In addition, whole-body images were performed with a gamma camera and blood taken for radioactivity determination. At 72 h post-injection, excellent tumour demarcation could be seen in seven of eight patients. The images obtained correlated well with the corresponding computed tomography images. Blood radioactivity levels gradually declined over the 72 h. Tumour uptake continued to rise throughout this time and, together with the steady fall in normal brain tissue, the tumour-to-brain contrast gradually increased (maximum 7:5). Whole-body images indicate that the liver is the major organ of uptake with up to 50% of the injected dose. No toxicity could be attributed to the injected liposomes. Although the total percentage uptake was low (1.1%), the tumour-to-brain contrast ratios, together with the SPET images, suggest the potential for tumour-specific targeting.

Brain Neoplasms↗
PubMed1997

Identification and characterization of pbpA encoding Bacillus subtilis penicillin-binding protein 2A.

Amino acid sequence analysis of tryptic peptides derived from purified penicillin-binding protein PBP2a of Bacillus subtilis identified the coding gene (now termed pbpA) as yqgF, which had been sequenced as part of the B. subtilis genome project; pbpA encodes a 716-residue protein with sequence similarity to class B high-molecular-weight PBPs. Use of a pbpA-lacZ fusion showed that pbpA was expressed predominantly during vegetative growth, and the transcription start site was mapped using primer extension analysis. Insertional mutagenesis of pbpA resulted in no changes in the growth rate or morphology of vegetative cells, in the ability to produce heat-resistant spores, or in the ability to trigger spore germination when compared to the wild type. However, pbpA spores were unable to efficiently elongate into cylindrical cells and were delayed significantly in spore outgrowth. This provides evidence that PBP2a is involved in the synthesis of peptidoglycan associated with cell wall elongation in B. subtilis.

Amino Acid Sequence↗
PubMed1996

Identification and characterization of pbpC, the gene encoding Bacillus subtilis penicillin-binding protein 3.

Penicillin-binding proteins (PBPs) are enzymes involved in the synthesis of peptidoglycan structures in Bacillus subtilis such as the vegetative cell wall and the spore cortex. The B. subtilis sequencing project has identified a gene (orf16, EMBL accession number D38161) which exhibits significant sequence similarity to genes encoding class B high-molecular-weight PBPs. We have found that orf16 encodes PBP3 and have renamed this locus pbpC. Transcriptional fusions to lacZ were used to demonstrate that pbpC is transcribed primarily during log-phase growth, with lower amounts expressed during sporulation. During spore germination and outgrowth, pbpC expression resumes coincident with an increase in the optical density of the culture. The major promoter for pbpC is located just upstream of the gene; a low level of expression during sporulation appears to originate from much further upstream. Loss of PBP3 does not produce any detectable change in phenotype with respect to cell morphology, growth, sporulation, spore heat resistance, or spore germination and outgrowth. This was also true when the pbpC mutation was combined with mutations affecting other PBP-encoding genes to produce double mutants. These findings are consistent with previous evidence that many PBPs of B. subtilis have redundant functions within the cell.

Amino Acid Sequence↗
PubMed1995

Pseudohypoparathyroidism type Ib is not caused by mutations in the coding exons of the human parathyroid hormone (PTH)/PTH-related peptide receptor gene.

Pseudohypoparathyroidism type Ib (PHP-Ib) is thought to be caused by a PTH/PTH-related peptide (PTHrP) receptor defect. To search for receptor mutations in genomic DNA from 17 PHP-Ib patients, three recently isolated human genomic DNA clones were further characterized by restriction enzyme mapping and nucleotide sequencing across intron/exon borders. Regions including all 14 coding exons and their splice junctions were amplified by polymerase chain reaction, and the products were analyzed by either temperature gradient gel electrophoresis or direct nucleotide sequencing. Silent polymorphisms were identified in exons G (1 of 17), M4 (1 of 17), and M7 (15 of 17). Two base changes were found in introns, 1 at the splice-donor site of the intron between exons E2 and E3 (1 of 17) and the other between exons G and M1 (2 of 17). Total ribonucleic acid from COS-7 cells expressing minigenes with or without the base change between exons E2 and E3 showed no difference by either Northern blot analysis or reverse transcriptase-polymerase chain reaction. Radioligand binding was indistinguishable for both transiently expressed constructs. A missense mutation (E546 to K546) in the receptor's cytoplasmic tail (3 of 17) was also found in 1 of 60 healthy individuals, and PTH/PTHrP receptors with this mutation were functionally indistinguishable from wild-type receptors. PHP-Ib thus appears to be rarely, if ever, caused by mutations in the coding exons of the PTH/PTHrP receptor gene.

Adolescent↗
PubMed1994

Increased risk of lung cancer after breast cancer radiation therapy in cigarette smokers.

BACKGROUND: Ionizing radiation is a lung carcinogen in a variety of settings, including after breast cancer radiation therapy. The authors explored whether cigarette smoking and breast cancer radiation therapy have a multiplicative effect on the risk of subsequent lung cancer. METHODS: This case-control study investigated women registered with primary breast cancer in the Connecticut Tumor Registry who developed a second malignancy between 1986 and 1989. Those diagnosed with a subsequent primary lung cancer were compared with those diagnosed with a subsequent nonsmoking, nonradiation-related second malignancy, and age-adjusted odds ratios were calculated with logistic regression. RESULTS: No radiation effects were observed within 10 years of initial primary breast cancer. Among both smokers and nonsmokers diagnosed with second primary cancers more than 10 years after an initial primary breast cancer, radiation therapy was associated with a 3-fold increased risk of lung cancer. A multiplicative effect was observed, with women exposed to both cigarette smoking and breast cancer radiation therapy having a relative risk of 32.7 (95% confidence interval [CI], 6.9-154). The radiation carcinogenic effect was observed only for the ipsilateral lung and not for the contralateral lung both in smokers and nonsmokers. CONCLUSIONS: Breast cancer radiation therapy, as delivered before 1980, increased the risk of lung cancer after ten years in nonsmokers, and a multiplicative effect was observed in smokers. For both smokers and nonsmokers, this effect was observed only for the ipsilateral lung and not the contralateral lung. Modern techniques, however, significantly decrease the radiation dose to the lungs, which may decrease the risk of lung cancer. Nonetheless, due to the available choices in early-stage breast cancer treatment, current practices may need to be revised for young breast cancer patients who smoke.

Breast Neoplasms↗
PubMed1994

Cigarette smoking and other behavioral risk factors for recurrence of colorectal adenomatous polyps (New York City, NY, USA).

Adenomatous polyps (hereinafter referred to as adenomas) are known precursors of colorectal cancer. Cigarette smoking has been associated with adenomas but not with colorectal cancer, while alcohol and fat intake have been associated with both adenomas and cancer in some studies. Approximately 30 percent of patients with resected adenomas develop another adenoma within three years. This case-control study explores the association of cigarette smoking with adenoma recurrence. Between April 1986 and March 1988, we administered a questionnaire to colonoscoped patients aged 35 to 84 years in three New York City (NY, USA) practices. We compared 186 recurrent polyp cases (130 males, 56 females) and 330 controls (187 males, 143 females) who had a history of polypectomy but normal follow-up colonoscopy, by cigarette-smoking pack-years adjusted for possible confounders. Risk for a metachronous or recurrent adenoma was significantly greater in the highest quartile of smokers than in never-smokers among both men (odds ratio [OR] = 1.8, 95 percent confidence interval [CI] = 1.0-3.4) and women (OR = 3.6, CI = 1.7-7.6). Adjustment for time since smoking cessation reduced risk only slightly, as did adjustment for dietary fat intake, which itself remained significant. No association was found between alcohol intake and risk of recurrence. Cigarette smokers appear to have an elevated risk of adenoma recurrence that is not eliminated entirely by smoking cessation. Intervention trials that use adenoma recurrence as an endpoint should take smoking into account.

Adenomatous Polyps↗
PubMed1994

Glottic configuration after arytenoid adduction.

It has been recently noted that laryngeal paralysis results in a complex alteration of the glottis. The membranous segment of the paralyzed vocal fold is shortened, and, during phonation, patients use hyperfunction to shorten the normal vocal fold to about the same length. Additionally, if the paralyzed vocal fold is not near the midline, the angle between the membranous and cartilaginous segments of the vocal fold is decreased, resulting in a "posterior" gap which cannot be closed by hyperadduction of the normal side. To determine whether arytenoid adduction addresses these problems, videolaryngoscopy was analyzed in 11 patients before and after surgery, and results were compared to patient satisfaction and acoustic and aerodynamic assessment. The posterior gap and glottic competence were improved in all patients, but only 6 had improvement in symptoms. Two had persistent vocal fold bowing but achieved good function after Teflon injection. Three patients, all with paralysis for more than 20 years, had no increase in vocal fold length and very little subjective vocal improvement. Arytenoid adduction is most effective in acute cases. Poor functional results in chronic paralysis are related to failure to achieve vocal fold lengthening, presumably due to soft-tissue contracture.

Arytenoid Cartilage↗
PubMed1993

Lung cancer after radiation therapy for breast cancer.

BACKGROUND: Radiation, including radiation therapy (RT) for a variety of conditions, is known to be a lung carcinogen. METHODS: Data from the Surveillance, Epidemiology, and End Results program of the National Cancer Institute for 1973-1986 were utilized to investigate whether RT for breast cancer affects the risk of subsequent lung cancer. The relative risk was calculated by comparing the incidence rate in patients with irradiated breast cancer with that in those with nonirradiated breast cancer. RESULTS: It was found that the risk of lung cancer overall was increased in women who underwent irradiation compared with those who were not irradiated 10 years after the initial breast cancer diagnosis with a relative risk of 2.0 (95% confidence interval, 1.0-4.3). In addition, the risk of lung cancer was in the ipsilateral lung compared with the contralateral lung for irradiated women. This increase was observed after 10 years for lung cancer overall and for the three major histologic subgroups (small cell, squamous cell, and adenocarcinoma). Specific information on RT doses and treatment plans and cigarette smoking were not available. CONCLUSIONS: It was concluded that RT for breast cancer may increase the risk of lung cancer after a latency period of 10 years.

Adult↗
PubMed1993

Dietary risk factors for the incidence and recurrence of colorectal adenomatous polyps. A case-control study.

OBJECTIVE: To investigate the association of dietary factors with the incidence and recurrence of colorectal adenomatous polyps. DESIGN: Two case-control studies. SETTING: Three university-based colonoscopy practices in New York City. PATIENTS: For the incidence study, 286 patients with pathologically confirmed incident adenomatous polyps (162 men and 124 women) were compared with 480 controls (210 men and 270 women) with no current or previous neoplasia. For the recurrence study, 186 patients with recurrent polyps (130 men and 56 women) were compared with 330 controls (187 men and 143 women). These patients had a history of polyps but no current neoplasia. MEASUREMENTS: Structured interviews using the Block food frequency questionnaire were conducted on all participants and were compared over quartiles of crude nutrient intake of total and saturated fat; fiber; protein; carbohydrates; carotene; vitamins A, C, and E; and various food groups. Data were adjusted for age, Quetelet index, and caloric intake by multiple logistic regression for men and women separately. RESULTS: For incident polyps, elevated adjusted odds ratios (high to low quartile) for women were found for saturated fat (odds ratio, 2.3; 95% CI, 0.9 to 5.8) and the ratio of red meat to chicken and fish intake (odds ratio, 1.9; CI, 1.0 to 3.6). Protective associations were observed for fish and chicken (odds ratio, 0.6; CI, 0.3 to 1.2) and vitamin A intake (odds ratio, 0.4; CI, 0.2 to 0.9). Among women, recurrent polyps showed an association with total dietary fat (odds ratio, 4.4; CI, 1.0 to 19.5), saturated fat (odds ratio, 3.8; CI, 1.0 to 14.9; P = 0.15 for the trend), and total fiber (odds ratio, 0.2; CI, 0.1 to 0.5; P = 0.01) and a borderline association with carbohydrates (odds ratio, 0.3; CI, 0.1 to 1.3; P = 0.10). No consistent relations were observed for men, although increased caloric intake increased the risk for incidence and recurrence in both men and women. CONCLUSIONS: These findings are consistent with previously described relations between diet and the incidence of colon cancer and suggest that, at least in women, dietary modification may be warranted in patients diagnosed with polyps.

Adult↗
PubMed1993

Nitric oxide production is inhibited in trauma patients.

Elevated levels of nitrates/nitrites, the stable endproducts of nitric oxide (NO), were recently observed in septic patients. In this setting, NO maintains blood flow by vasodilation and inhibition of platelet aggregation. Trauma patients were found to have low plasma levels of nitrates/nitrites, even when they developed sepsis. The current study substantiated that trauma patients have suppressed production of NO; reductions in plasma nitrate/nitrite levels correlated with low urinary excretion of these endproducts. Nitric oxide production was upregulated in trauma patients with clinical infection compared with trauma patients without infection, but was still significantly suppressed compared with nitric oxide production in normal controls. The inability of trauma patients to produce NO may be an important component of the susceptibility of these patients to infection.

Adolescent↗