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Biomedical subjects

R Ray

Publications and source records attributed to R Ray.

At least 235 records · Page 13Linked to original sources
PubMed1983

Modulation of synapse formation by cyclic adenosine monophosphate.

Synapses between neuroblastoma-hybrid cells and myotubes exhibit a high degree of plasticity. Increase of cyclic adenosine monophosphate (AMP) levels of the hybrid cells for several days results in the appearance of functional voltage-sensitive Ca2+ channels, which are required for evoked secretion of acetylcholine. The results show that cyclic AMP regulates synaptogenesis by regulating the expression of voltage-sensitive Ca2+ channels, and suggest that cyclic AMP affects posttranslational modifications of some glycoproteins and cellular levels of certain proteins.

Animals↗
PubMed1983

Measuring the costs of children: an alternative approach.

Problems related to the concept of the "cost of a child", more commonly known as the general equivalence scale, are reviewed. The importance of this concept is noted with regard to both theoretical and empirical studies relating to taxation, poverty, income distribution, dietary needs, income maintenance programs, supplementary and child benefits, and other social security payments. "This paper proposes a new methodology for calculating the scale using a framework which is consistent with utility theory and which overcomes the identification problem without having to enforce the arbitrary prior assumptions of recent studies. The proposed method allows easy calculation of not only the basic 'scale' parameter but also how it varies with price and reference utility. [The author illustrates] the usefulness of the procedure by estimating on U.K. budget data at two different levels of aggregation and employing two sets of quite different functional forms. The results are plausible, compare favourably with one another and, hence, confirm the robustness and usefulness of the proposed procedure."

Adolescent↗
PubMed1983

Peritonitis in continuous ambulatory peritoneal dialysis patients.

Peritonitis is the most important complication of continuous ambulatory peritoneal dialysis (CAPD). We reviewed our experience with peritonitis over a 2 1/2-year period. Our patients spent 4% of their total time on dialysis in hospital due to peritonitis. Thirty-eight percent of the episodes of peritonitis were treated without hospitalization. We evaluated the dialysate bag change technique as commonly performed with currently available devices (extension tubing and titanium Luerlock Tenckhoff catheter adapter). The aseptic techniques described for dialysis extension tubing changes appear adequate (with no increased incidence of peritonitis demonstrated shortly after an extension tubing set change). Long-term sterility is maintained at the dialysate bag puncture port and at the orifice of the dialysis catheter adapter (no positive cultures from the bag port and orifice of the titanium adapter). Etiologic diagnosis of uremia was not a risk factor predisposing to peritonitis. The incidence of peritonitis was greater among patients with less formal education and lower income. Out data suggest that patients with less formal education and of lower economic status be carefully evaluated before commencing CAPD.

Bicarbonates↗
PubMed1983

Evaluation of continuous ambulatory peritoneal dialysis.

This study was undertaken to ascertain whether 19 patients maintained on continuous ambulatory peritoneal dialysis (CAPD) for at least 1 year experienced any deterioration in peritoneal membrane function. Selected serum chemistries and skinfold measurements were also evaluated to determine whether patients dialyzed by CAPD could maintain a normal nutritional status. This study demonstrates that patients maintained on CAPD had stable dialysate protein losses, glucose absorption from the dialysate, and constant urea, creatinine, and sodium removal. When these patients were subdivided by incidence of peritonitis, the group with a lower incidence of peritonitis (one episode every 349 +/- 155 SEM days) showed stable serum protein concentration and improvement in upper arm area whereas the group with a high incidence of peritonitis (one episode every 95 +/- 7 SEM days) showed a reduction in upper arm muscle area. Thus, our data suggest that over a 1-year period, there is no deterioration in peritoneal membrane characteristics and CAPD is effective in maintaining the nutritional status of the patient. However, both membrane function and nutritional status may be impaired by frequent episodes of infection.

Adolescent↗
PubMed1983

Comparison of home hemodialysis to continuous ambulatory peritoneal dialysis.

We evaluated prospectively various outcome measurements of patients assigned initially to continuous ambulatory peritoneal dialysis (CAPD) and home hemodialysis (HHD) from February 1979 to August 1981 and the causes for failures of the techniques. Morbidity was assessed by time in hospital/time on dialysis. Fifty-six patients were trained for CAPD and 37 for HHD. Those assigned to CAPD experienced an increased frequency of hospitalization (7.5% CAPD, 2.8% HHD, respectively) primarily due to episodes of peritonitis. There was also a higher modality failure rate (43% vs. 16%). However, the groups were not comparable in all respects. For example, the CAPD population included 21 patients with major cardiovascular diseases versus only three in the HHD group. The demographic characteristics of both populations including race, sex, age, income, place of residence, marital status, and education were similar. At the time of this study there is no direct evidence showing that healthy patients otherwise able to perform HHD may be maintained with less morbidity for a prolonged period utilizing CAPD. Therefore, we suggest that HHD is the home method of choice for patients able to proceed with this technique. CAPD may be indicated for patients in whom the period of home dialysis is expected to be relatively short and who would be otherwise unable to carry out home dialysis, for example, patients awaiting transplantation and those unable to be maintained on hemodialysis because of impaired cardiac function. To fully evaluate CAPD as a long-term maintenance therapy, a prospective trial must be performed.

Adult↗
PubMed1982

Clinical assessment and follow-up of functional capacity in patients with chronic congestive cardiomyopathy.

The presumption that the results of left ventricular systolic function tests performed at rest are related to the symptoms of chronic congestive heart failure or to exercise capacity is unproved. Thirty-three patients with chronic congestive cardiomyopathy underwent serial exercise tests, determinations of ejection fraction and systolic time intervals, echocardiograms, assessment of symptom score, chest roentgenogram, and physical examination over a mean ( +/- standard deviation) of 24.8 +/- 14.1 months. Maximal exercise performance achieved correlation with symptoms (r = 0.66) but not with indexes of left ventricular function. Edema, elevated jugular venous pressure, rales and radiologic evidence of pulmonary venous hypertension were more common in patients with severe limitation of exercise capacity. in 17 patients whose functional capacity changed during the follow-up period, congruent changes in left ventricular function measured at rest were not consistently observed. Thus the findings on history, physical examination and radiologic examination correlate with exercise capacity, but indexes of left ventricular performance at rest do not and therefore are of limited use in assessing treatment. The clinical course of patients with chronic congestive cardiomyopathy can be followed up safely, effectively and economically by simple clinical observations. Serial laboratory testing of left ventricular function can be reserved for specific indications, research and patients with valvular heart disease.

Adult↗
PubMed1982

Walk-in clinic drop-outs.

Data were collected among 159 consecutive new patients in a walk-in clinic. Patients were given an appointment for a subsequent visit after the initial clinical diagnostic interview, and 61% completed their referral. A long waiting list and a diagnosis of depressive neurosis were significantly associated with drop-out. Possible forms of follow-up are suggested.

Adult↗
PubMed1981

Peritoneal abnormalities during infectious episodes of continuous ambulatory peritoneal dialysis.

Exchanges were performed in 1-hour and 3- to 5-hour cycles when patients were noninfected and during episodes of peritonitis. The hourly exchange dialysate effluent volume decreased with the occurrence of peritonitis. These exchanges were associated with increased glucose absorption from dialysate, diminished sodium removal and augmented clearances of urea and creatinine. Protein losses were increased in the dialysate effluent of patients during an episode of peritonitis during the hourly exchanges. In the long-dwell exchanges obtained after clinical improvements of peritonitis, only protein losses were increased over control. Clearances, sodium loss in dialysate and glucose absorption were not altered from control.

Adult↗
PubMed1981

Continuous ambulatory peritoneal dialysis. Treatment of dialysis-related ascites.

Continuous ambulatory peritoneal dialysis is a new dialysis technique. It is unknown at this time which patient would be served best by this therapy. Two cases of dialysis-related ascites were successfully treated by this technique. We suggest that the continuous control of salt and water balance possible with this technique, as well as frequent drainage of the peritoneal cavity to prevent fluid reaccumulations, contributed to successful treatment. Continuous ambulatory peritoneal dialysis may be used to treat dialysis-related ascites.

Adult↗
PubMed1980

Lower limb anomalies in the thrombocytopenia absent-radius (TAR) syndrome.

We report a case of the TAR syndrome with severe abnormalities of the lower limbs. The syndrome of thrombocytopenia and radial deformities occasionally presents diagnostic difficulties when severe limb anomalies are present. Based on this case and 2 additional cases from the literature, reduction anomalies of the lower limbs should be considered part of the TAR syndrome.

Female↗