Local variations of the dynamic elastic modulus around running cracks

The variation of the dynamic elastic modulus in the immediate vicinity of the tip of the running crack was studied through an iterative procedure, based on the theoretical expressions for the stress-field components and the experimental relation between strain rate and elastic modulus. It was found that the elastic modulus varied strongly around the tip of the crack, both in radial and polar sense. Also it was observed that the polar distribution of the elastic modulus presented clear off-axis extrema in directions that were in good agreement with experimentally measured branching angles, thus indicating a possible relation between these two phenomena.     

Kinetic analysis of papaya proteinase omega

Papaya proteinase omega (pp omega) has been purified from dried latex both by immunoaffinity and traditional methods. Kinetic analysis revealed that (1), the pp omega-catalysed hydrolysis of N-benzoyl-L-arginine p-nitroanilide (BApNA) has a lower specificity (kcat/Km) than the same reaction catalysed by papain; (2), the pp omega-catalysed hydrolysis of a tripeptide substrate having phenylalanine at the second position (S2-site) showed a more similar specificity to that catalysed by papain; (3), the significant difference between the two enzymes is that steady state kinetics with both L-BApNA and a tripeptide enables the identification in pp omega of other ionizations affecting binding. The active sites of papain and pp omega can therefore be distinguished by pH-dependence of kcat/Km.     

Determination of the radiation sensitivity of the stromal cells in the murine long-term bone marrow culture by measuring the induction and rejoining of interphase chromosome breaks

PURPOSE: To determine the radiosensitivity of bone marrow stromal cells, the rate of interphase chromosome breakage and rejoining of stromal cells in the murine long term bone marrow culture and of human skin fibroblasts were compared. METHODS AND MATERIALS: The cells were irradiated with doses up to 6 Gy and repair times up to 6 hr were investigated. After induction of premature chromosome condensation by fusing the cells with mitotic HeLa cells, the number of interphase chromosome fragments was counted. RESULTS: The number of radiation induced breaks was found to be not significantly different for both cell types with 6.16 +/- 0.26 breaks per Gray for the fibroblasts and 5.96 +/- 0.20 breaks per Gray for the stromal cells. A significant difference was observed in the repair rate. The fibroblasts rejoined 39.6% of the breaks induced initially during the first hour after irradiation and 5.6 +/- 1.84 breaks remained unrejoined after 6 hr, while the stromal cells were able to rejoin 63.2% in 1 hr and had 2.05 +/- 0.07 breaks unrejoined after 6 hr. CONCLUSION: If the well substantiated assumption is made, that the capacity to repair DNA double strand breaks or interphase chromosome breaks is correlated with the cellular radiosensitivity, this finding indicate, that murine bone marrow stromal cells are more radioresistant than human skin fibroblasts.     

Reliability and validity of the measurement of position sense in women with osteoarthritis of the knee

OBJECTIVE: We examined the test-retest reliability and the construct validity of the measurement of knee position sense for describing the functional weightbearing performance of women with osteoarthritis (OA) of the knee. METHODS: For the purpose of this study, position sense was defined as the error occurring when subjects attempted to reproduce a criterion angle in standing with visual cues eliminated. Five such tests were recorded photographically on 3 different occasions. On each occasion the 10 subjects also completed a self-paced walking test over a 13 m indoor walkway. RESULTS: The photographic measurements were reproducible (r = 0.90) and there was no change in positioning accuracy across sessions. There was a significant (p < 0.05) inverse correlation of 0.70 between the standard deviation of the mean individual measurements of position sense (precision of the test) and those of walking speed. CONCLUSION: Our study demonstrates good measurement reliability and a comparable mean angular error with repeated tests. It also suggests the amplitude of the variability of this error is a strong determinant of an individual OA patient's functional performance in walking.     

A coverage plan for health centres in Murewa district in Zimbabwe: an example of action research

Good access to health facilities providing good first-level health care remains problematic in many developing countries. It is a hindrance to effective and efficient functioning of the hospital, as outpatient departments become overcrowded with patients from areas without health centres. In many cases the quality of care delivered to these patients is poor because within the district health system the hospital is not the best place for the supply of comprehensive, integrated and continuous care. Eventually, high hospital involvement in first-level care can jeopardize the delivery of adequate referral care for those patients who desperately need the hospital's technology and expertise. This paper provides an account of the way this problem was investigated and managed by the district health management team in the Murewa district in north-east Zimbabwe. The design of a comprehensive 'master plan' or 'coverage plan' is presented as well as the problems and difficulties encountered. The Murewa experience highlights the relevance of a coverage plan for rational and coherent health infrastructure planning at district level. The approach followed by the Murewa team illustrates the use of action research as an integral part of the management of district health systems.     

Percutaneous endoscopic gastrostomy (PEG) in upper gastrointestinal tract occlusion in gynecologic oncology

BACKGROUND AND AIMS: Intestinal obstruction is a frequent cause of death in patients suffering from gynecological cancer, who have undergone multiple treatment in the form of surgery and/or chemotherapy and/or radiotherapy. The usual form of rescue treatment consists in the use of a nasogastric tube to administer support and analgesic treatment. Surgical gastrostomy is not a viable proposition in these extremely weak patients with large masses compressing and displacing the stomach. Percutaneous endoscopic gastrostomy (PEG), a technique first introduced for nutritional purposes, can be beneficially used to achieve decompression in these patients. METHODS: PEG was performed in a total of 67 patients who had already undergone multiple treatment for abdominal-pelvic neoplasia with upper gastrointestinal obstruction, who could no longer be operated and who had a life expectancy of less than sixty days. In three cases positioning was not possible owing to the lack of transillumination of the gastric and abdominal wall. 54/64 patients had previously undergone at least two operations. RESULTS: Esophagogastric lesions were found in 29% of patients, some of which were attributed to the nasogastric tube. Symptomatic wellbeing was obtained in 76.5% a few days after PEG. PEG remained in situ from 4 to 472 days. Slight peristomal infection was observed in 9% of cases. In seven cases it was necessary to add octreotide owing to the reappearance of symptoms. CONCLUSIONS: PEG is relatively easy to use and allows obstructive symptoms to be resolved in the majority of patients. Special medical skills are not required and the patient may be easily managed at home together with support therapy and pain management. Once PEG has been performed, it is possible to take fluids and semi-liquid foods, offering the patient a chance to taste flavours which have often been forgotten. PEG enables neoadjuvant chemotherapy to be performed in patients with previously untreated intestinal obstruction.     

Adherence to pharmacologic management of hypertension

Adherence to pharmacologic therapy of hypertension is low (in the range of 50-70%) and has important implications both for blood pressure control and cardiovascular complications. Based on a review of the literature using the levels of evidence grading technique, determinants of adherence to the pharmacologic therapy of hypertension have been assessed. Additionally, interventions to improve compliance were evaluated. Patient-centred, health care provider-centred and drug-specific factors have all been shown to affect adherence rates. We conclude that the extent of adherence to pharmacologic therapy is modifiable. Measurable improvements in adherence can be obtained from simplified medication regimens and a combination of behaviour strategies, including the tailoring of pill-taking to patients' daily habits and rituals, the advocacy of self-monitoring of pills and blood pressure, and the institution of reward systems.