Biomedical subjects
M Kaye
Publications and source records attributed to M Kaye.
Direct functional assessment of human osteoblasts by radioautography: methodology and application in end stage renal disease.
Fragments approximately 1 mm3 of freshly obtained iliac crest cancellous bone were incubated for 30 minutes at 37 degrees C in Krebs buffer containing 3H-leucine or 3H-proline followed by radioautography. Grains per osteoblast, reflective of protein synthetic activity, were counted in normal controls and patients with end stage renal disease with or without significant aluminum storage in their bones. Compared with control the end stage renal disease patients without significant aluminum storage had more large osteoblasts with increased grain counts which were ascribed to secondary hyperparathyroidism. Cells from patients with greater than 30% surface aluminum had more small osteoblasts with grain counts intermediate between control and less than 2% aluminum, ascribed to an inhibitory effect of aluminum on the secondary hyperparathyroidism. Cell activity did not depend on location next to a tetracycline label or osteoid and it was suggested that all bone lining cells could be considered as osteoblasts. Aluminum storage was associated with impaired mineralisation in the presence of normal or increased osteoblastic protein synthetic activity suggesting that in these patients the mineralisation defect was not primarily due to an abnormality in osteoblast function.
Can "ethical" clinical trials be unethical?
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Identification of rat osteoclasts in bone smears with quantification of acid phosphatase activity in vitamin D deficiency.
Vitamin D deficiency may depress bone formation but its effect on bone resorption is not well defined. As an index of bone resorption, the activity of acid phosphatase, a lysosomal enzyme found in osteoclasts, was quantitated in situ from a bone tissue smear preparation. Activity of the enzyme, measured by integrative microdensitometry increased linearly from 25 to 60 min. The distribution of activity in osteoclasts quantitated appeared to follow a normal distribution with a median value of 0.19 integrated optical density units. Animals treated with vitamin D or 1,25 dihydroxycholecalciferol had significantly increased activity of acid phosphatase in osteoclasts compared to animals which were vitamin D deficient. The increase of acid phosphatase activity averaged 63%. Vitamin D or its metabolites may have a permissive effect on the action of parathyroid hormone or act directly to increase bone resorption.
Dialyzer reuse following manual reprocessing with a new sterilant, RenNew-D.
Dialysis patients are at risk for toxicity from formaldehyde used in the reprocessing of dialyzers for reuse; therefore, replacing formaldehyde as a dialyzer sterilant would be advantageous. The potential for RenNew-D as a sterilizing agent was investigated in seven stable in-center hemodialysis patients over 20 consecutive dialyses with cuprammonium cellulose hollow-fiber dialyzers. Treatment with RenNew-D showed no toxicity to patients or dialyzers except for two blood leaks occurring in one patient. The mean number of dialyzer uses was 4.9. In all the dialyzers that passed functional testing small solute clearances were maintained with reuse. The ability of RenNew-D to improve the biocompatibility of reused dialyzers was documented with mean neutrophil counts falling to only 78% of initial values during first reuse of dialyzers processed with RenNew-D compared with a decrease in neutrophil count to 2% of initial values during first use of the same dialyzers. Our results suggest that RenNew-D may be a useful alternative to formaldehyde for the purpose of dialyzer reuse. A reuse procedure that includes processing with RenNew-D is associated with improved biocompatibility, possibly because of maintenance of the blood-derived membrane coating established during prior dialysis.
Physicians' non-compliance with patients' refusal of life-sustaining treatment.
Should patients be treated when they have specifically refused treatment? Three competent patients are described with end-stage renal disease who, against the advice of their family, friends and care-givers, refused dialysis. Each was treated and subsequently they acknowledged their satisfaction with the outcome. Guidelines for treating patients when consent is refused are discussed and it is suggested that this is permissible in life-saving situations where the patients' refusal is idiosyncratic and irrational.
Patient access to medical records in a forensic center: a controlled study.
Several psychiatric facilities have opened their records partially or completely to patients. The authors report the results of a two-part study in which 20 patients on a minimum-security unit of a forensic center were allowed to read their records and later to write in them. Staff and patient attitudes toward granting patients access to their records were measured before and during the study and were compared with staff and patient attitudes on two units where patients were not granted access. Only eight study patients actually read their charts and none wrote in them, but the majority of both study and control patients felt that access had been helpful. No significant differences in patient behaviors were found on any of the units as a result of access. Staff attitudes toward access did not differ significantly before or after the study, and few differences were found in staff charting practices.
The right to remain silent during psychiatric examination in civil and criminal cases--a national survey and an analysis.
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Discontinuation of dialysis therapy in the demented patient.
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Effect of RenNew-D as a sterilant on the performance of reused dialyzers.
RenNew-D (Alcide), a novel demand-release sporocidal agent, was employed instead of formaldehyde in the reprocessing for reuse of cuprophan hollow fiber dialyzers (Gambro) and the performance of these dialyzers was evaluated over 40 consecutive dialyses in six patients on maintenance hemodialysis. When RenNew-D was part of automated reprocessing performed with 4.3% bleach as specified by the manufacturer (Lixivitron), dialyzer survival was prolonged (16.7 +/- 7.2 uses) and hemodialysis neutropenia was unchanged with reuse. When RenNew-D was part of manual reprocessing conducted in the absence of bleach, marked improvement in dialyzer biocompatibility was observed but with a decreased survival (4.8 +/- 3.0). The majority of dialyzer failures were due to a fall in fiber bundle volume below a 85% set limit. Small solute clearances were maintained with both types of reprocessing. Dialyses were well tolerated throughout. Our data suggest that RenNew-D is a safe and efficacious product which can serve as a valuable alternative to formaldehyde for the purpose of dialyzer reuse.
Dialyser reuse: a study in applied medical ethics.
A dialysis unit's introduction of automated recycling of dialysers is described. The responses of the staff and the patients are outlined, along with the pertinent ethical issues. Suggestions regarding the educational processes necessary with any innovation in long-term medical care are discussed.
Aluminum and phosphate: the double bind.
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Osteoclast enlargement in endstage renal disease.
In normal subjects and patients with endstage renal disease, osteoclast cell volumes were constructed using serial 2-micron thick plastic embedded sections from iliac crest bone biopsy specimens. Four cells randomly selected from each of the subjects were analyzed to give both the cell volume from the cumulative areas and thickness of each cell slice and also the cell axes taking the vector along the bone face as width or Y, thickness from the bone surface as breadth or X and vertical dimension length or Z. The mean cell volume was 6,230 microns3 in the control subjects and was significantly larger being 11,730 microns3 and 13,680 microns3 in the two patient groups. The cells showed polarity with the largest axes, Y and Z, being those in apposition to the bone surface. Howship's lacunae were enlarged in the patients and the cross-sectional area of an individual lacuna corresponded to the area of the contiguous osteoclast, r = 0.62, P less than 0.001. All patients had secondary hyperparathyroidism and osteoclast numbers were increased. There was no correlation between osteoclast size and duration of renal failure, previous vitamin D intake, or aluminum exposure. It is suggested that in ESRD, osteoclasts undergo both an increase in number and size and that these cells, being larger, remove more bone than the smaller cells in normal subjects.
Consent to dialyzer reuse: is it ethically necessary?
It is argued that consent by the patient to reuse dialyzers which have been mechanically cleansed is not required provided adequate standards of practice and safety are utilized. Based on medical benefits, administrative order and cost saving we propose that specific informed consent for such reuse should not be mandatory and that it could at times be unhelpful, both to care givers and recipients.
Miranda comes to the hospital: the right to remain silent in civil commitment.
One procedural protection that has not generally made the transition from the criminal justice system to involuntary civil commitment is the Fifth Amendment protection against self-incrimination. The authors present the results of a study of the implementation of the right to remain silent, which demonstrate that warning patients that anything they say may be used against them in the commitment hearing has little impact on their willingness to talk to staff or to cooperate with treatment. The authors discuss the possible reasons for their findings.
Residual formaldehyde in new and reused dialyzers.
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Dialyzer performance over prolonged reuse.
Studies were performed in patients on maintenance hemodialysis to evaluate the role of prolonged dialyzer reuse in the management of end-stage renal disease. For this purpose the patients were dialyzed without interruption with the same hollow fiber dialyzers (GambroR 120M) reprocessed with the Lixivitron IIR equipment. The data obtained from in vivo clearances in sixteen patients demonstrate that membrane permeability to small solutes (urea, creatinine, phosphate) is maintained up to thirty dialyzer uses. In vitro studies confirmed this observation and established that clearances of larger solutes (vitamin B12) are also maintained over similar extensive dialyzer reuse. Hematological and blood gas studies were performed serially during dialysis in five additional patients. Although circulating leucocyte and neutrophil counts, hemoglobin concentration as well as arterial pH and partial pressures of oxygen and carbon dioxide changed appropriately during dialysis, there was no observable difference from the first to the twentieth use of the same dialyzer. Thus, these results clearly demonstrate that prolonged dialyzer reuse in end-stage renal disease patients constitutes a stable form of renal replacement therapy provided adequate dialyzer reprocessing is applied.