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Biomedical subjects

J Bowman

Publications and source records attributed to J Bowman.

At least 37 records · Page 2Linked to original sources

Expression and regulation of mutant forms of cardiac TnI in a reconstituted actomyosin system: role of kinase dependent phosphorylation.

When phosphorylated, the inhibitory subunit of troponin (TnI) causes a loss in calcium sensitivity and a decrease in actomyosin ATPase. To examine this process, we bacterially expressed wild type TnI and TnI mutants in which serine 22 and 23, a putative protein kinase A (PKA) site, and threonine 143, a putative protein kinase C (PKC) site, were replaced by alanine S22A/23A and TI43A. PKA dependent phosphorylation was approximately 90% reduced in the S22A/23A mutant and unaffected in T143A. PKC dependent phosphorylation was markedly reduced in T 143A relative both to a wild type construct and to S22A/23A, although some residual phosphorylation (likely at sites other than T143) was seen. The calcium sensitivity (i.e. inhibition of actomyosin ATPase in the presence of EGTA) and regulation of the reconstituted actomyosin system was preserved in the absence of phosphorylation using wild type TnI or either mutant. Calcium sensitivity was decreased by both PKA and PKC with the wild type TnI but was unaffected by PKA when the S22A/23A mutant was employed and by PKC when the T143A mutant was reconstituted. The calcium dependency of the ATPase curve was substantially right shifted when PKC phosphorylated wild type TnI was employed for regulation, and this was markedly attenuated when T143 A was reassociated (although a slight rightward shift and a reduction in maximal ATPase activity was still seen). These data confirm that phosphorylation of TnI by regulatory kinases plays a major role in the regulation of myofibrillar ATPase. The N-terminal serines (22 and 23) appear to be uniquely important for the PKA response whereas threonine 143 is involved in the PKC response although other residues may also have functional significance.

Actomyosin↗

Development of specialist dermatology nurse prescribing.

In 1993, nurses on the dermatology unit at the Cumberland Infirmary, Carlisle, undertook a prescribing trial in order to assess and evaluate the accuracy and safety of nurse prescribing in this specialty. The aim was to demonstrate a positive outcome with evidence which would provide a sound, logical argument to explore the legal right of experienced dermatology nurses to prescribe where necessary within the unit. Five nurses and three senior house officers (SHOs) took part in the study which compared their theoretical prescriptions for treatment with two consultants who actually prescribed. Sixty one per cent of treatment prescribed by the SHOs was of the same type and potency as the consultants' choice. Nursing staff, however, accurately prescribed 80 per cent of the topical treatment the patients received. The authors conclude that nurses should be given more prescribing rights.

Consultants↗

Los Angeles study of residential magnetic fields and childhood brain tumors.

A measurement study of residential magnetic fields and brain tumors in children that was added onto an ongoing case-control interview study in Los Angeles County, California, include 298 children under age 20 years with a primary brain tumor diagnosed from 1984 to 1991 and 298 control children identified by random digit dialing. Magnetic fields were determined for all Los Angeles homes where these 596 children lived from conception to diagnosis (1,131 homes) by mapping and coding the wiring configurations outside the home and by taking a series of exterior spot and profile measurements. In addition, for a subset of subjects (35%; 211 homes) 24-hour measurements were taken in the child's room and one other room. Although measured fields are consistently highest in the highest of the five wire code categories, fields in homes in this category are much lower in Los Angeles than in Denver, where the code originated. Brain tumor risk appears not to relate to measured fields inside (p for trend for child's room = 0.98) or outside (p for trend for front wall = 0.82) the home. An apparent increase in risk among children living at diagnosis in homes with underground wiring appears to be an artifact introduced by using current controls for historical cases because this apparent excess risk disappeared in an analysis restricted to the later years of the study when cases and controls were accrued concurrently. Our study does not show an overall association of pediatric brain tumors with measured fields, with "very high" wiring configurations, or with any of several other potential sources of exposure, such as use of various electrical appliances, but the prevalence of high fields (> 2 mG) and very high fields (> 3 mG) in Los Angeles homes was too low to detect a moderate effect of the magnitude reported in other studies.

Adolescent↗

Mental health status of a Latin American community in New South Wales.

OBJECTIVE: To determine the levels and predictors of psychological distress within a Latin American community in the Hunter region of New South Wales, Australia. METHOD: Participants (n = 184) were interviewed in their homes by a bilingual interviewer using a specially prepared questionnaire and the General Health Questionnaire (GHQ-12). RESULTS: Of the 13 independent variables examined, two demographic and two immigrant-related variables were significantly associated with an above-threshold score: marital status, employment status, perceived discrimination, and dissatisfaction with life in Australia. CONCLUSIONS: Compared to results from other community surveys, the levels of psychological distress within this Latin American community appear to be relatively high.

Acculturation↗

Play it safe in long-term care facilities.

Instead of caring for patients, nurses and other healthcare workers at long term facilities are increasingly becoming patients themselves. Over the past decade, the injury rate among nursing home workers jumped by 55%, with more than 200,000 of these workers injured annually. This article discusses the types of injuries suffered and how they can be prevented.

Accidents, Occupational↗

A randomised controlled trial of strategies to prompt attendance for a Pap smear.

OBJECTIVE: To assess the comparative efficacy, by randomised controlled trial, of three interventions designed to encourage "at risk" women to have a Pap smear: an educational pamphlet; letters inviting attendance at a women's health clinic; and letters from physicians. METHODS: Subjects at risk for cervical cancer who had not been adequately screened were identified by a random community survey and randomly allocated to one of the intervention groups or a control group. Six months after intervention implementation, a follow up survey assessed subsequent screening attendance. Self report was validated by comparison with a national screening data base. RESULTS: A significantly greater proportion of women (36.9%) within the group receiving a physician letter reported screening at follow up than in any other group (P = 0.012). The variables most strongly predicting screening attendance were: age, perceived frequency of screening required, use of oral contraceptives, and allocation to receive the physician letter intervention. CONCLUSIONS: The relative efficacy of the GP letter in prompting screening attendance shows that this strategy is worthy of further investigation. There remains a need to examine the barriers to screening for older women, and to develop tailored strategies for this population.

Adolescent↗

Mechanisms of recovery of swallow after supraglottic laryngectomy.

This study examines oropharyngeal swallow disorders and measures of pharyngeal and laryngeal movement during deglutition from videofluorographic studies of oropharyngeal swallow in 9 patients who had undergone supraglottic laryngectomy and 9 age-matched normal subjects. The swallows of surgical patients were examined at 2 weeks and 3 months postoperatively. Two critical factors in recovery of swallowing were identified: (a) airway closure at the laryngeal entrance, that is, the space between the arytenoid cartilage and the base of the tongue, and (b) the movement of the tongue base to make complete contact with the posterior pharyngeal wall. When patients achieved these two functions, they returned to normal swallowing. The duration of tongue base contact to the posterior pharyngeal wall and extent of anterior movement of the arytenoid increased significantly from 2 weeks to 3 months in the surgical patients. At 2 weeks postsurgery, patients who had undergone supraglottic laryngectomy exhibited significantly shorter airway closure and tongue base to pharyngeal wall contact, reduced laryngeal elevation, increased width of cricopharyngeal (CP) opening, and later onset of airway closure and tongue base movement than normal subjects. These significant differences remained at 3 months postoperatively, although swallow measures were moving toward normal in the patients who had undergone supraglottic laryngectomy. Comparison of patients not eating at 2 weeks with patients at the time of first eating revealed significantly longer duration of tongue base contact to the pharyngeal wall, longer duration of airway closure, and greater movement of the arytenoid in patients who were eating. Results indicate that the focus of swallowing therapy after supraglottic laryngectomy should be on improvement of posterior movement of the tongue base and anterior tilting of the arytenoid to close the airway entrance and improve bolus propulsion (in the case of the tongue base).

Barium Sulfate↗

Impact of the diagnostic procedure on outcome measures of swallowing rehabilitation in head and neck cancer patients.

This study was designed to determine whether swallow rehabilitation outcomes were affected by the type of evaluation procedure utilized by the clinician. The two evaluation techniques compared were the bedside examination and videofluoroscopy (the modified barium swallow). Ten institutions participated in this study, enrolling a total of 103 partial laryngectomized patients, 21 in the bedside arm and 82 in the videofluoroscopy arm. Data on recovery of oral intake were collected weekly. All patients received an X-ray study of swallow at 3 months after the operation. Mean time to oral intake of food was significantly lower in patients assessed with bedside examination. Overall swallow measures of transit times and swallow efficiencies after 3 months revealed significantly better function in the videofluoroscopy group. Results are discussed in terms of the visibility of swallow physiology with the two assessment techniques, the accuracy of therapy planning with the bedside examination versus videofluoroscopy and the ability of head and neck cancer patients to tolerate some aspiration without developing aspiration pneumonia.

Deglutition↗

Effects of dietary fish oil on myocardial ischemic/reperfusion injury of Wistar Kyoto and stroke-prone spontaneously hypertensive rats.

The purpose of the present study was to determine whether 15 weeks of dietary fish oil supplementation to Wistar Kyoto (WKY) and stroke-prone spontaneously hypertensive rats (SP-SHR) would alter cardiac contractile performance. Isolated perfused working hearts were used to determine the effects of varying left atrial filling pressures on cardiac pump output and pressure development. In addition, the ability of these hearts to recover cardiac output after a 60-minute period of low-flow ischemia followed by 30 minutes of reperfusion was assessed. Myocardial high-energy phosphate levels and long-chain acylcarnitine content were measured. Fish oil supplementation had no effect on indirect tail-cuff systolic blood pressure of WKY rats, but produced a small decrease in systolic blood pressure of SP-SHR. In response to varying left atrial filling pressures, hearts from WKY rats and SP-SHR exhibited no major differences in aortic flow, left intraventricular diastolic pressure, systolic pressure, positive and negative rate of pressure change per unit of time (dP/dt), or relaxation time; however, coronary flow values were lower in SP-SHR groups relative to respective WKY groups. Fish oil supplementation had no effect on these cardiac parameters. When these hearts were subjected to ischemia and reperfusion, the recovery of cardiac contractile performance was significantly improved in fish oil-fed WKY and SP-SHR groups, compared with their corn oil-fed counterparts. There were no differences in the recovery of the above cardiac hemodynamic parameters between corn oil-fed WKY and SP-SHR. These results provide further support to the hypothesis that dietary fish oil can significantly reduce the mortality risk from cardiovascular disease.

Animals↗

Metabolic effects of treadmill exercise training on the diabetic heart.

This study determined whether exercise training in rats would prevent the accumulation of lipids and depressed glucose utilization found in hearts from diabetic rats. Diabetes was induced by intravenous streptozotocin (60 mg/kg). Trained diabetic rats were run on a treadmill for 60 min, 27 m/min, 10% grade, 6 days/wk for 10 wk. Training of diabetic rats had no effect on glycemic control but decreased plasma lipids. In vivo myocardial long-chain acylcarnitine, acyl-CoA, and high-energy phosphate levels were similar in sedentary control, sedentary diabetic, and trained diabetic groups. The levels of myocardial triacylglycerol were similar in sedentary control and diabetic rats but decreased in trained diabetic rats. Hearts were perfused with buffer containing diabetic concentrations of glucose (22 mM) and palmitate (1.2 mM). D-[U-14C] glucose oxidation rates (14CO2 production) were depressed in hearts from sedentary diabetic rats relative to sedentary control rats. Hearts from trained diabetic rats exhibited increased glucose oxidation relative to those of sedentary diabetic rats, but this improvement was below that of the sedentary control rats. [9,10(-3)H]palmitate oxidation rates (3H2O production) were identical in all three groups. These findings suggest that exercise training resulted in a partial normalization of myocardial glucose utilization in diabetic rats.

Animals↗

Functional results after total or near total glossectomy with laryngeal preservation.

Locally advanced tongue cancer is a devastating disease for which there are limited therapeutic options that will result in a high rate of cure while preserving function. To determine the oncologic effectiveness of total or near total glossectomy with laryngeal preservation and the possibility of speech and swallowing rehabilitation following treatment, we reviewed our experience with 27 patients treated between 1982 and 1989. Twenty-four patients were eligible for 2-year follow-up and their disease-specific survival was 51%. Swallowing was achieved initially in 18 patients (67%), while 12 had successful long-term deglutition (44%). Oral communication was accomplished in 25 patients (92%). Significant aspiration occurred in three patients and was severe enough to require interval laryngectomy in two patients. The role of laryngeal suspension, palatal augmentation prosthesis, and videofluoroscopy as rehabilitation adjuncts for the total glossectomy patient are described.

Adult↗

Light reflection rheography: an effective non-invasive technique for screening patients with suspected deep venous thrombosis.

Light reflection rheography is a simple non-invasive technique for assessing venous function in the leg. One hundred and twenty-four patients referred for venography with a clinically suspected deep venous thrombosis were investigated by light reflection rheography to determine the accuracy of the technique in diagnosing acute thrombosis. In half of the patients venography confirmed a deep venous thrombosis. Light reflection rheography had a sensitivity of 92 per cent and a specificity of 84 per cent in detecting acute thrombosis. The technique had a negative predictive value of 92 per cent in selecting those patients with no thrombosis. Light reflection rheography can be performed at the bedside or in the radiography department which makes it a suitable technique for screening patients with suspected deep venous thrombosis.

Female↗

Intravenous drug abuse causes Rh immunization.

Intravenous drug abuse causes many health problems. From March 1989 to January 1990 of 27 Rh-negative women (28 pregnancies) referred to our centre, 4 women (5 pregnancies) were Rh immunized due to the sharing of needles and blood with their Rh-positive partners. Severe hydrops was present in 4 of their 5 fetuses when they were first seen at 17-35 weeks of gestation. Only the fetus first seen at 35 weeks survived. That infant was moribund at birth and now has evidence of leukomalacia and porencephaly. The fifth fetus, not hydropic, required two intravascular fetal transfusions in order to survive. A fifth woman, immunized in a similar manner, had a spontaneous abortion. These fetuses represent some of the earliest and severest examples of hydrops fetalis ever seen at our centre. The severity of their fetal hemolytic disease is probably due to the fact that their mothers' exposure to Rh(D) antigen by blood sharing was continuous and ongoing. Because of their aberrant behaviour, these women have suffered irreversible reproductive damage.

Abortion, Spontaneous↗

Diarrheal disease due to Clostridium difficile in general practice.

A total of 288 stool samples from patients attending their general practitioners was examined for the presence of Clostridium difficile. C. difficile or its cytotoxin was found in 16 patients (5.5%) and was the most common enteric pathogen detected. Most patients had only mild to moderate diarrhea but in the majority of patients the diarrhea was protracted. Eleven of the 16 patients had received antimicrobial agents in the 3 mths preceding onset of diarrhea and there was good circumstantial evidence that 2 other patients had also been exposed. None of the patients had a history of any inflammatory bowel disease or possible occupational exposure. The prescribing habits of general practitioners with regard to antimicrobial agents were monitored for a 1 yr period. Tetracyclines and amoxycillin accounted for approximately 25% each of all prescriptions dispensed. Ten of the 16 patients were treated with antimicrobials (mainly metronidazole) and in most cases the diarrhea resolved. We conclude that C. difficile may be a significant cause of community-acquired diarrhea.

Adult↗