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Biomedical subjects

S M Rosen

Publications and source records attributed to S M Rosen.

At least 19 recordsLinked to original sources

Transdermal fentanyl: seeding trial in patients with chronic cancer pain.

In this study, 6 patients with pain from advanced cancer were enrolled in a multicenter, open-label seeding trial of transdermal fentanyl. Following equianalgesic dose conversion, transdermal fentanyl patches were applied every 3 days. Mean fentanyl dosage doubled by week 2 and tripled by week 4. Pain control improved in all patients. There were no significant changes in mood, constipation, nausea, sedation, daily activities, or interpersonal relationships from pretrial to posttrial analyses. Following the study period, 5 patients were monitored for a mean total of 55 days with a mean final fentanyl dose of 240 micrograms/hr. As part of a comprehensive cancer pain management program, transdermal fentanyl appears to be safe and effective, and should prove to be a useful addition to currently available opioid analgesics.

Administration, Cutaneous

External electrical stimulation of the cochlea: clinical, psychophysical, speech-perceptual and histological findings.

Our progress towards the development of a particular form of cochlear implant for the totally deaf is described. A single channel stimulation at the round window or promontory is used. This involves a minimum of surgical intervention and infective risk, preserves the possibility of remission and allows the application of later developments. The signal used for stimulation is designed to be matched both to the deaf lip-reader's needs and to his new, restricted, auditory ability. This is done by concentrating on the acoustic pattern components of speech which carry intonation and voiced-voiceless information. Surgical electrophysical, psychoacoustic and speech perceptual aspects of our work with twelve patients are described. The tests involve responses, for example, relating to: threshold for sinusoids; frequency difference limens; periodic -aperiodic discrimination; stress placement; and consonant labelling using combined visual and electrical inputs. Relatively extensive measurements were made with six patients. Significant individual differences were found and the sets of responses provide an essential basis for an appraisal of the potential usefulness of our work to the individual patient. Possible reasons for the individual differences are discussed. A brief indication is given of the techniques which we have developed for the future speech training and speech production evaluation of patients with electro-cochlear voice monitoring. The final section of our paper mentions our histological investigation of the effects of this type of stimulation in the guinea pig.

Acoustic Impedance Tests

Nephrotoxicity of paraquat in man.

Renal function studies were performed in three cases of paraquat poisoning. Acute renal failure was observed in all three cases. Glomerular filtration rate improved for two patients who survived three weeks, illustrating the reversible nature of paraquat-induced acute renal failure. A mild to moderate transient proteinuria was observed during the first and second weeks following paraquat ingestion. Renal glucosuria, marked amino aciduria, and increased fractional excretion of phosphorus, sodium, and uric acid were observed. These findings, which have not been previously described in man, are indicative of proximal tubular dysfunction and parallel observations previously made in experimental animals.

Acute Kidney Injury

Serum ferritin level. Determinant of iron requirement in hemodialysis patients.

Seventeen patients without renal failure and 14 patients receiving long-term hemodialysis were studied. Serum and bone marrow ferritin determinations were made at the time of bone marrow aspiration. A good correlation was found between serum ferritin levels and bone marrow iron stores, as well as between bone marrow ferritin levels and iron stores. Serum ferritin determinations appear to give an accurate estimation of bone marrow iron stores, thereby providing a reliable guide for iron replacement therapy and reducing the need for repeated bone marrow aspirations. Serum ferritin levels of less than 105 ng/ml suggest decreased iron stores, and values greater than 120 ng/ml indicate adequate or increased iron stores. Preliminary data also suggest that bone marrow ferritin determinations may be useful in quantitating bone marrow iron stores.

Anemia, Hypochromic

Hemodialysis in treatment of acute chloral hydrate poisoning.

A young pregnant (32 weeks' gestation) woman with severe chloral hydrate intoxication was treated with hemodialysis. This resulted in dramatic improvement of her profound central nervous system depression, protracted ventricular arrhythmias, fetal distress, and resumption of spontaneous respiration. The blood concentration of trichloroethanol was measured hourly during the dialysis and its dialysance was calculated. This experience suggests that hemodialysis may be a useful adjunct in the treatment of severe chloral hydrate poisoning.

Adult

Maintenance hemodialysis in myeloma kidney disease.

Maintenance hemodialysis and chemotherapeutic agents were used in the treatment of seven patients with end-stage myeloma kidney disease. Results indicate that with the use of such therapy life can be prolonged substantially. It appears that patients with myeloma-with or without serious extrarenal complications-are suitable candidates for maintenance hemodialysis and should not be denied the treatment even in the face of systemic neoplasm.

Adult

Use of expanded polytetrafluoroethylene grafts for vascular access in hemodialysis: laboratory and clinical evaluation.

Vascular access for chronic hemodialysis has evolved considerably over the past 10 years with development of vascular substitutes. The bovine heterograft is the choice of most dialysis centers when a subcutaneous conduit is needed in lieu of an in situ arteriovenous fistula. Bovine grafts have solved some problems, but further improvement in blood access prostheses is needed. Polytetrafluoroethylene (PTFE) grafts were evaluated in a laboratory and clinical study. In animals, PTFE proved to be satisfactory for fistula construction based on patency, incorporation into tissue, and ease of puncture. Ten patients underwent 11 vascular access procedures using PTFE grafts as a conduit. There were no technical operative complications. One graft was occluded by extravasation during dialysis and flow could not be restored. Otherwise, all grafts are patent 9 to 18 months postoperatively. Grafts of 8.0 mm in diameter have not given desirable flow rates, whereas 6.0 mm grafts have. Prolonged bleeding from puncture has been a problem in some cases. Otherwise, PTFE appears to be a satisfactory conduit for hemodialysis vascular access.

Adolescent

Compression neuropathy subsequent to renal transplantation.

Compression neuropathy occurred in 7 patients who underwent renal transplantation. The neuropathy occurred on the same side as the surgery and was associated with the use of selfretaining retractors. Other contributing factors were presence and degree of uremia and diabetes. We suggest that self-retaining retractors be used carefully and length of application reduced to a minimum. Efficient dialysis prior to transplantation may decrease the incidence and severity of neurologic deficit by reducing the extent of uremia.

Adult

Effect of dialysate calcium concentration on bone disease in patients on hemodialysis.

Plasma biochemistry, bone radiology and morphometry were studied in a group of 20 patients receiving maintenance hemodialysis. The aim was to determine if increasing the dialysate calcium concentration would decrease plasma parathyroid hormone and improve the radiologic appearances of bone in patients without producing serious side effects. Dialysate calcium concentration was increased stepwise from 4.5 to 6.0 and then to 7.0 mg/100 ml. Mean predialysis plasma calcium concentration increased from 9.4 to 9.7 and then to 10.0 mg/100 ml and mean predialysis phosphate concentration increased from 5.3 to 5.6 mg/100 ml. Parathyroid hormone concentration was elevated in all patients but the mean concentration did not change significantly although in seven patients a decrease occurred. Six patients had radiologic signs of renal bone disease, two patients showed improvement and three patients developed bone disease during the study. The patients with radiologic bone disease had the highest parathyroid hormone concentrations and the majority were female. Morphometric bone measurements showed that bone loss during the study occurred mainly in the male patients. Soft tissue calcification continued to appear during the study. Although the response to some patients to an increased dialysate calcium concentration was favorable, it was impossible to predict which types of patient would benefit from the use of a dialysate calcium concentration of 7.0 mg/100 ml.

Adult

Paraquat poisoning: new aspects of therapy.

Clinical, laboratory, and pulmonary physiologic features of three fatal cases of paraquat poisoning are presented. Experimental investigations and clinical experience would suggest several possible means of modifying paraquat toxicity. The following specific therapeutic interventions, several of which had previously been applied only in experimental circumstances, were used: (1) inhibition of absorption of paraquat with Fuller's Earth and catharsis by magnesium sulfate, (2) elimination of absorbed paraquat by hemodialysis with ultrafiltration and forced diuresis, (3) competition by d-propranolol for tissue binding sites, (4) modification of direct pulmonary tissue effects of paraquat by hypoxic breathing mixtures, superoxide dismutase, and corticosteroids. Treatment was unsuccessful. However, our clinical experience and data concerning paraquat concentration in body and dialysis fluids suggest a therapeutic approach aimed at preventing early and progressive tissue damage. A combination of Fuller's Earth and magnesium sulphate should be used immediately and in frequently repeated doses to prevent absorption. Diuresis and haemodialysis should be instituted as soon as possible to increase excretion. Hypoxic atomspheres should be created urgently to produce a PaO2 of 40-45 mmHg, and the use of superoxide dismutase be further investigated. It is hoped that the high mortality of paraquat poisoning will be modified by this combined approach of early and intensive treatment.

Adolescent

Hemodialysis of acute arsenic intoxication with transient renal failure.

A striking reduction in serum arsenic level was achieved after four hours of hemodialysis in a patient with acute arsenic intoxication and transient renal failure. Quantitative dialysance of arsenic and a comparison of daily urinary excretion of arsenic with amount removed by dialysis suggested that hemodialysis is indicated in the treatment of acute arsenic intoxication if there is concomitant renal failure. In the presence of normal renal function, supportive measures, including dimercaprol (BAL in Oil) therapy, constitute the best available treatment.

Acute Disease

Insulin and growth hormone secretion in the nephrotic syndrome.

Carbohydrate metabolism was studied in a series of patients with the nephrotic syndrome and compared with a similar number of normal controls. The nephrotic syndrome was associated with a smaller secretion of insulin in response to intravenous glucose and tolbutamide than occurred in normals. In the syndrom fasting serum growth hormone (G.H.) concentrations were increased and did not show the characteristic suppression after glucose administration, and the disappearance rate of glucose (k value) was lower. well marked correlation existed between serum G.H. concentrations and the total urinary protein excreted. These abnormal findings returned to normal in a patient who underwent a repeat study when the nephrotic syndrome had resolved.

Adolescent