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Biomedical subjects

M Brennan

Publications and source records attributed to M Brennan.

At least 127 records · Page 7Linked to original sources
PubMed1984

Is routine episiotomy necessary?

One hundred and eighty one primigravid women delivering vaginally in July and August 1982 in the Rotunda Hospital, Dublin, were randomly allocated to one of two groups. Patients in one group were to undergo episiotomy. Those in the other group were not to undergo episiotomy unless it was considered to be essential. The outcome was compared with that of the clinical practice over the previous six months at the hospital. Of the 92 patients allocated not to undergo episiotomy, seven (8%) had one done for medical reasons compared with 507 (89%) in the previous six months. First degree tears occurred in 23 (25%) and second degree tears in 43 (47%). Nineteen (21%), however, retained an intact perineum compared with only 35 (6%) of the women who had delivered in the preceding six months. Assessments of perineal pain, bruising, swelling, and healing and records of ingestion of analgesics were made for the first four days after delivery, and again at a check up six weeks after delivery, in patients who had had spontaneous vertex deliveries. Forty patients who underwent episiotomy and 37 who sustained a second degree tear formed two comparable groups. There was no difference in outcome between them. Data were also evaluated for 19 women who retained an intact perineum, 22 who sustained a first degree tear, and 11 who underwent episiotomy and epidural anaesthesia; all 52 of these women had spontaneous vertex deliveries. Despite severe soft tissue injury in two patients those who fared best were those who retained an intact perineum. First degree tears were associated with symptoms similar to those associated with second degree tears. Those who fared worst were women who underwent episiotomy after epidural anaesthesia. The value of routine episiotomy in primigravid patients is questioned, but the final decision can be made only by the accoucheur at the time of imminent delivery.

Adolescent↗
PubMed1984

Tuberculosis and nonsteroidal anti-inflammatory drugs.

In 1980 and 1982 two case reports documented reactivation of pulmonary tuberculosis in patients who had used nonsteroidal anti-inflammatory drugs (NSAIDs). A case-control study was designed to test the hypothesis that such an association does exist. Data for 38 patients were obtained from the patients' family physicians, and each patient was matched with a control from the same practice for age, sex, race and length of time in that practice. A statistically significant relation was found between the reactivation of tuberculosis and the use of NSAIDs. However, further research is imperative to determine whether the association is direct, indirect or secondary to an unknown factor. Physicians should keep in mind that NSAIDs are potent anti-inflammatory agents and may thus activate, spread and mask infections.

Aged↗
PubMed1984

Relationship of natural killer cytotoxicity to clinical and biochemical parameters of primary human breast cancer.

We have determined the natural killer (NK) activity of peripheral blood lymphocytes obtained from 121 women undergoing surgery for primary breast cancer. NK activity was measured using 51Cr-labeled K562 target cells and effector: target ratios of 100:1, 50:1 and 10:1. The patients' lymphocytes gave a wide range of values with a mean (+/- S.E.) cytotoxicity of 22.6% +/- 1.3, and a median of 20.9% at the 50:1 effector:target ratio. These results did not differ significantly from the mean and median NK levels obtained with the peripheral blood lymphocytes of normal blood donors (mean = 23.1% +/- 1.9, median = 18.8%). Mean NK activity determined at the first postsurgical examination (less than or equal to 6 months postoperative) was significantly lower than the mean NK activity at surgery. The most significant decreases were seen in patients undergoing chemotherapy prior to the first follow-up examination. Subsequent tests (greater than 6 mo, less than or equal to 12 mo) show a recovery of NK activity to preoperative levels. A negative correlation was seen between NK level and maximum tumor diameter. NK levels also varied with tumor histiotype. No association was seen between NK levels and either the number of involved lymph nodes, pathologic tumor grade, the presence of estrogen or progesterone receptor, or the age, menopausal status or smoking history of the patients. A positive correlation was seen, however, between NK levels and number of pregnancies and live births.

Adult↗
PubMed1983

Perceptual dimensions of infant cry signals: a semantic differential analysis.

In the present study the Semantic Differential technique was used to examine perceived characteristics of infant cry sounds. 24 cries (6 each of pain, hunger, birth, and "pleasure") were rated by 39 mothers on 50 scales. A factor analysis of the scale ratings uncovered three main factors, labelled Affect, Potency, and Evaluation, respectively. 5 "factorially-pure" scales were selected to represent each factor. A hierarchical cluster analysis of the mean factor-scale ratings uncovered 3 major cry clusters which essentially represented 3 cry-type groups, hunger, pleasure, and pain/birth. A close correspondence was found between this set of clusters and another set generated independently from cry-recognition data, indicating that the semantic differential factor-scales effectively discriminated perceptually distinct cries. This procedure adequately separates the physical (acoustic) properties of signals from their listener-perceived (auditory) ones. This distinction is not possible with studies which depend upon multivariate techniques and casts doubt on their findings.

Adult↗
PubMed1983

The organization of cross-linking in collagen fibrils.

The cross-linked peptides in cyanogen bromide digests from rabbit and calf fibrils of type I collagen have been compared by gel filtration and electrophoresis. Fibrils were prepared in vitro from acid-soluble collagen, or tendons were used; both were reduced with borohydride to stabilize cross-linking adducts. The cross-linked peptides were isolated and hydrolyzed, and the reducible cross-links were analyzed. We propose that a prominent pattern of cross-linking involves in-register palisades of molecules overlapping by 27 nm and joined through the condensation of amino-terminal aldol adducts on the carboxy-terminal helical regions of overlapping molecules. Lateral association probably occurs through the carboxy-terminal aldehydes from two molecules forming tri- or quadrivalent adducts with residues in the overlapped molecule. This model favors the recently proposed quasi-hexagonal organization of molecules in fibrils in which rows of molecules occur in lateral register.

Animals↗
PubMed1982

Collagenase digestion demonstrates carboxy-terminal crosslinking in acid-soluble collagen.

Among the products of the collagenase cleavage of Type I acid-soluble collagen from calf and rabbit tendons, there can be found fragments with the lengths of half alpha-chains. Because purified collagenase cleaves the alpha-chains three-quarters of the length from the amino-terminus, the presence of half-length chains is evidence for the occurrence of crosslinks between two carboxy-terminal, quarter-length fragments, The collagen preparations were reduced with [3H]borohydride, the collagenase-cleaved fragments were separated by gel electrophoresis, and their 3H-labeled crosslink derivatives were analyzed. The major labeled components in the half-length chains were the reduced aldol condensation product and hydroxylysinonorleucine. These experiments demonstrate that the carboxy-terminal telopeptides in monomer-enriched collagen samples form aldol crosslinks which are probably intramolecular, but some intermolecular aldol and aldimine crosslinks may also be formed.

Animals↗
PubMed1982

Age-related changes in EGF and protease in submandibular glands of C57BL/6J mice.

The submandibular glands of male C57BL/6J mice were studied cytologically and chemically at the following ages (months): 1-1.5, 6-8, 12-13, 28-32. The relative proportion of granular convoluted tubules (GCT), as well as the size and content of secretion granules of GCT cells, progressively increased throughout the first year of life. Correspondingly, the concentration within the glands of two GCT cell products, epidermal growth factor (EGF) and protease, also steadily increased. In senescent glands, GCTs formed relatively less of the gland parenchyma and were composed of shorter cells with reduced amounts of secretory granules. The concentration of EGF was reduced to 17% of its peak value at one year, while protease activity declined to 50% of its peak value. These morphologic and chemical findings imply a functional impairment in submandibular glands of the mouse with senescence.

Aging↗
PubMed1982

The treatment of soft-tissue sarcomas of the extremities: prospective randomized evaluations of (1) limb-sparing surgery plus radiation therapy compared with amputation and (2) the role of adjuvant chemotherapy.

Between May 1975 and April 1981, 43 adult patients with high-grade soft tissue sarcomas of the extremities were prospectively randomized to receive either amputation at or above the joint proximal to the tumor, including all involved muscle groups, or to receive a limb-sparing resection plus adjuvant radiation therapy. The limb-sparing resection group received wide local excision followed by 5000 rads to the entire anatomic area at risk for local spread and 6000 to 7000 rads to the tumor bed. Both randomization groups received postoperative chemotherapy with doxorubicin (maximum cumulative dose 550 mg/m2), cyclophosphamide, and high-dose methotrexate. Twenty-seven patients randomized to receive limb-sparing resection and radiotherapy, and 16 received amputation (randomization was 2:1). There were four local recurrences in the limb-sparing group and none in the amputation group (p1 = 0.06 generalized Wilcoxon test). However, there were no differences in disease-free survival rates (71% and 78% at five years; p2 = 0.75) or overall survival rates (83% and 88% at five years; p2 = 0.99) between the limb-sparing group and the amputation treatment groups. Multivariate analysis indicated that the only correlate of local recurrence was the final margin of resection. Patients with positive margins of resection had a higher likelihood of local recurrence compared with those with negative margins (p1 less than 0.0001) even when postoperative radiotherapy was used. A simultaneous prospective randomized study of postoperative chemotherapy in 65 patients with high-grade soft-tissue sarcomas of the extremities revealed a marked advantage in patients receiving chemotherapy compared with those without chemotherapy in three-year continuous disease-free (92% vs. 60%; p1 = 0.0008) and overall survival (95% vs. 74%; p1 = 0.04). Thus limb-sparing surgery, radiation therapy, and adjuvant chemotherapy appear capable of successfully treating the great majority of adult patients with soft tissue sarcomas of the extremity.

Adolescent↗
PubMed1981

Lithium carbonate and granulocyte production: dose optimization.

To determine the optimal dose of lithium for inducing granulocytosis, the authors administered lithium carbonate to normal volunteers at five dose levels. The authors performed assessments of circulating and marginated blood pools of granulocytes and of marrow reserve granulocytes to confirm that the early granulocytosis following lithium administration is due to increased granulocyte production rather than redistribution. At 300 mg/day and 600 mg/day, lithium had no significant effect on granulocyte production. Doses of 900, 1200, and 1500 mg/day, corresponding to lithium levels of 0.55 to 1.50 mEq/liter, were associated with increased granulocyte production. Within this therapeutic range, no correlation between lithium level and granulocyte production was demonstrated. This study suggests that any lithium dose which achieves a lithium level of greater than 0.55 mEq/liter, i.e., doses greater than or equal to 900 mg/day, is adequate to induce granulocytosis. While lithium did not increase platelet production, doses of 900 mg/day to 1500 mg/day were associated with decreased bleeding times.

Adult↗
PubMed1981

Computed tomographic evaluation of laryngeal neoplasms.

Nineteen patients with laryngeal lesions each underwent diagnostic studies consisting of laryngoscopy and computed tomography (CT). Sixteen patients had linear tomography and coronal and sagittal reconstruction of their transaxial CT images. The results of each examination were compared with the surgical and pathological findings to assess their relative value. The results confirmed previous reports of the accuracy and value of transaxial CT and direct laryngoscopy, but indicated that coronal and sagittal reconstruction as well as linear tomography added no significant information.

Carcinoma, Squamous Cell↗
PubMed1981

A study of patients with psychosocial problems in a family practice.

This study was conducted to test the hypothesis that family practice patients with intrapersonal psychosocial problems are likely to be identified as having more health problems in general than patients not afflicted in this way. A second general objective of the study was to provide a health profile of patients having intrapersonal problems as compared with patients who do not. The total number of patients identified as having intrapersonal problems was 321 patients, 30.5 percent of this teaching practice population, but for purposes of the study a small sample (n = 94) was randomly selected. A control group was randomly selected from patients matched by age and sex in the practice. Study group patients were found to have a significantly greater number of family problems, hospital admissions, major surgical procedures, number of visits to the practice, gastrointestinal disorders, and illness due to inflammatory causes when compared to controls. This group was also found to have received more psychiatric care, more attention from allied health professionals, and more frequent psychotropic drugs. This study suggests that family physicians care for a cohort of patients with a high frequency of psychosocial problems and that these patients have an increased use of health care services.

Adolescent↗
PubMed1979

Sterile host yeasts (SHY): a eukaryotic system of biological containment for recombinant DNA experiments.

A system of biological containment for recombinant DNA experiments in Saccharomyces cerevisiae (Brewer's/Baker's yeast) is described. The principle of containment is sterility: the haploid host strains all contain a mating-type-non-specific sterile mutation. The hosts also contain four auxotrophic mutations suitable for selection for the various kinds of vectors used. All vectors are derivatives of pBR322 which can be selected and maintained in both yeast and Escherichia coli. The system has recently been certified at the HV2 level by the National Institutes of Health.

Containment of Biohazards↗