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Biomedical subjects

J Owen

Publications and source records attributed to J Owen.

At least 19 recordsLinked to original sources
PubMed1992

Melatonin suppression in human subjects by bright and dim light in antarctica: time and season-dependent effects.

Full-spectrum light, of sufficiently high intensity, will suppress the secretion of melatonin at night in humans. Individual sensitivity to such suppression is variable, and the factors determining such sensitivity are largely unknown. By analogy with animal work previous short or long-term exposure to different light intensities may be an important determinant. We exploited the Antarctic environment to investigate these possibilities. Groups of healthy men, living on the British Antarctic Survey Base at Halley (75 degrees South) were exposed to dim (range 290-310 lux) and bright (range 2100-2300 lux) light either from 01.00-02.00 h or 05.00-0.600 h, both in winter and in summer. Plasma melatonin concentrations were determined by radioimmunoassay in serial blood samples taken before, during and after light treatment, and in control (darkness) conditions. Light suppression of melatonin was more effective in the latter part of the night in winter and this was particularly well-differentiated for dim light.

Adult↗
PubMed1992

Seminoma of the testis: long-term beneficial and deleterious results of radiation.

PURPOSE: The followup of 387 patients in a USA national survey of seminoma treated with radiation in 1973 and 1974 has been extended beyond 15 years to assess the long-term benefits and problems resulting from treatment. RESULTS: Survival at 15 years is 83% for Stage I, 68% for Stage II; freedom from recurrence at 15 years is 93% for Stage I, 96% for Stage II; NED survival at 15 years is 80% for Stage I, 68% for Stage II; cause specific freedom from cancer death is 98% for Stage I and 97% for Stage II at 15 years. Second malignancy rates were 8% at 15 years, and observed in 14 patients versus 4.2 expected (p < .001). Deaths due to these second cancers were also increased with seven observed versus two expected (p < .01). Non-cancer intercurrent disease death occurred in 23 patients versus 7.5 expected (p < .01). The most frequent cause was cardiac death which appeared in 10 patients versus 4.4 expected (p < .05) and 8 of the 10 patients received mediastinal radiation. Two additional patients died of pulmonary fibrosis after mediastinal radiation. Mediastinal radiation correlated with all intercurrent disease and cardio-pulmonary deaths (p < .05), but not with second malignancies. With the exception of one, all patients experiencing cardiac death after mediastinal irradiation were 40 years or older at the time of treatment, with a range of 32-58 years and a mean interval to death of 9.8 years. CONCLUSIONS: Recommendations for the future management of seminoma include: reducing the irradiated volume in the treatment of Stage I patients, completely eliminating mediastinal radiation in the treatment of patients with Stage IIA seminoma and treating patients with Stage IIB seminoma with chemotherapy. Radiation dose should not exceed 30 Gy for Stage I or 35 Gy for Stage IIA.

Adolescent↗
PubMed1992

Transverse uterine incision closure: one versus two layers.

OBJECTIVE: Closure of a low transverse cesarean incision with one layer of suture results in less operating time, better hemostasis, and less infectious morbidity than a two-layer closure. STUDY DESIGN: At our institution 906 women were randomized to closure of a low transverse cesarean incision with either one continuous layer of a locking No. 1 chromic suture and a CTX needle (n = 457) or two continuous layers of No. 1 chromic suture with the first layer locked (n = 449). The Student t test, chi 2 test of proportion, and Wilcoxon rank sum test were used to compare groups of patients. RESULTS: A one-layer closure required less operative time, 43.8 versus 47.5 minutes (p = 0.0003). Fewer additional uterine hemostatic sutures were required in 369 women in whom either the one- (n = 179) or the two-layer (n = 190) closure did not achieve hemostasis (p = 0.046). Endometritis was similar in both groups, 83 (22%) in the one-layer group versus 65 (18%) in the two-layer group (p = 0.17). In no outcome assessment was the two-layer closure superior to the one-layer closure. CONCLUSION: We recommend a one-layer closure when its use is anatomically feasible.

Adult↗
PubMed1992

Midtrimester pregnancy termination: a randomized trial of prostaglandin E2 versus concentrated oxytocin.

OBJECTIVES: The purpose of this study was to determine whether a concentrated oxytocin infusion can reliably effect uterine evacuation in the midtrimester and whether such an infusion is associated with fewer side effects than prostaglandin E2 vaginal suppositories. STUDY DESIGN: Patients received either prostaglandin E2 (n = 42) or oxytocin (n = 45) for indicated midtrimester abortions in a prospective, randomized trial. Treatment consisted of either prostaglandin E2 vaginal suppositories (one every 4 hours) or infusions of an escalating concentration of oxytocin (one every 4 hours). Unless delivery had occurred or was imminent after 24 hours, the agent was considered to have failed, and patients were crossed to the alternative method. RESULTS: Delivery indications were similar between the two groups. There were 6 (14%) first-agent failures with prostaglandin E2 and 9 (20%) with oxytocin (p = 0.48). Considering the failures and subsequent crossovers, 103 patient trial regimens were completed. Fever, nausea, vomiting, and diarrhea were more frequent with prostaglandin E2 (p < 0.005). CONCLUSIONS: Concentrated oxytocin is a satisfactory alternative to prostaglandin E2 for midtrimester abortion.

Abortifacient Agents↗
PubMed1992

Lithium treatment: a comparison of once- and twice-daily dosing.

The effects of once- and twice-daily dosing with lithium carbonate were compared in a non-blind, cross-over study on 20 consecutive patients with mood disorders. Mental status, side effects and target organ function were examined after a minimum of a 1-month treatment with each regimen. Eighteen patients completed the study and 2 withdrew because of side effects. There were no significant differences between the 2 groups on the Hamilton Rating Scale for Depression, the Bech-Rafaelsen Mania Scale, the UKU Side Effects Scale or in serum lithium, electrocardiogram and urine volumes. Most blood tests showed no significant difference between the 2 treatment schedules except for white blood cells, ionized calcium and phosphate concentration. The once-daily regimen was associated with a higher white cell count, increased serum phosphate and elevated serum ionized calcium. We conclude that patients are able to tolerate once-daily dosing with lithium carbonate as well as twice-daily dosing.

Adolescent↗
PubMed1978

Intraoperative autotransfusion for elective aortic surgery.

Intraoperative autotransfusion using the Bentley ATS 100 was used in 23 patients requiring Dacron replacement of their abdominal aorta. An average 2000 ml of blood was reinfused and a total heparinization dose was given. The mean haemoglobin fell 2.8 g/dl and on average 2 pints of banked blood were given in the postoperative period. Coagulation studies performed before and after surgery showed minimal alteration. We feel that further evaluation of this system is essential so that an alternative is established for when banked blood is not available. The system is particularly useful at the present time for such emergencies as a leaking abdominal aortic aneurysm and severe trauma to the liver.

Aorta, Abdominal↗
PubMed1978

Review of cervical orthoses.

Six commonly prescribed cervical orthoses are presented for a qualitative review of their structural properties and their clinical applicability. A quantitative review of each brace has previously been reported. The characteristics of 1) structure, 2) ease of donning, 3) ease of adjusting, 4) comfort, and 5) general clinical applicability are summarized for each brace. Generally, as the orthosis becomes more restrictive, it also becomes more cumbersome and more difficult to don. Ease of adjustment and comfort are compromised. The one exception was the Somi orthosis which was comfortable, easy to don and adjust, and which still provided good stability in forward flexion. The information presented in this paper in conjunction with information on the quantitative qualities of each brace and the services available at most health care facilities may be used as a guide for selecting specific cervical orthoses.

Braces↗
PubMed1977

Spectinomycin hydrochloride in the treatment of gonorrhoea: Its effect on associated Chlamydia trachomatis infections.

Sixty-three heterosexual men were successfully treated with a single injection of spectinomycin hydrochloride 2 g for urethral infections with Neisseria gonorrhoeae. Chlamydia trachomatis was recovered from the urethra of 11 of these men both before and after treatment. In six men, the organism was isolated after but not before treatment. No isolates were obtained from the remaining men either before or after treatment. All 17 of the men who yielded C. trachomatis developed post-gonococcal urethritis. Eight of 46 men from whom no isolate was obtained in their cultures developed post-gonococcal urethritis. Seventeen of 50 women successfully treated with spectinomycin for cervical infections with N. gonorrhoeae yielded isolates of C. trachomatis both before and after treatment. The organism was isolated from five women before but not after treatment, and from four women after but not before treatment. In 24 women culture for C. trachomatis was negative both before and after treatment. Spectinomycin hydrochloride in the dosage used rarely eliminated C. trachomatis from the genital tract of either men or women; in this respect it resembled two other drugs commonly used for the treatment of gonorrhoea-pencillin and ampicillin.

Chlamydia Infections↗