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Biomedical subjects

P Stewart

Publications and source records attributed to P Stewart.

At least 127 records · Page 7Linked to original sources

Proteinuria and renal function in diabetic patients fed a diet moderately restricted in protein.

Protein restriction has been used in the treatment of renal disease and may also be beneficial in the management of diabetic nephropathy. We evaluated the effects of moderate protein restriction (0.6 g/kg ideal body weight per day) for a 3-mo period on renal function in seven diabetic patients. Moderate protein restriction led to a decrease of approximately 50% in the albumin excretion rate in patients with overt proteinuria or microalbuminuria. This decrease occurred in some patients without a decrease in glomerular filtration rate, renal plasma flow, or plasma albumin concentration and may reflect subtle changes in filtration properties or permeability of glomeruli. In this pilot study moderate protein restriction has marked effects on albumin excretion irrespective of the initial degree of renal impairment. It is therefore suitable for longer-term study of its effects on the progression of renal disease in both patients with overt and incipient diabetic nephropathy.

Adult↗

High-dose cytarabine and total body irradiation with or without cyclophosphamide as a preparative regimen for marrow transplantation for acute leukemia.

Twenty-nine patients were conditioned for allogeneic marrow transplant with cytarabine (ara-C) (3 g/m2 every 12 hours for 12 doses) and total body irradiation (TBI) (200 cGy daily for six days) with or without cyclophosphamide (CY) (60 mg/kg) to determine toxicity and efficacy. Four patients had chronic myelogenous leukemia (CML) in accelerated phase or blast crisis, and 25 patients had acute leukemia, 24 at stages later than first remission. Three patients (10%) had fatal regimen-related toxicity and another 10% experienced severe toxicity in at least one organ system. The addition of CY to the ara-C and TBI regimen was not associated with an increase in the frequency of severe toxicity. Twenty-five of 29 patients engrafted eight to 33 days posttransplant: three died early before engraftment, and one patient failed to engraft. Ten of 29 patients are alive without disease, and the actuarial probability of disease-free survival for the entire group at 3 years is 33%. Three of ten patients with acute nonlymphocytic leukemia (ANL), six of 15 with acute lymphocytic leukemia (ALL), and one of four with CML are alive and disease free 25 to 42 months (median, 30 months) after transplant. High-dose ara-C (HDara-C) and TBI with or without CY can be administered with approximately the same toxicity as CY plus TBI. Phase III studies appear warranted to determine if these newer regimens provide improved results compared with currently used regimens.

Acute Disease↗

Associations between several sites of cancer and ten types of exhaust and combustion products. Results from a case-referent study in Montreal.

A population-based case-referent study provided information on the associations between several types of cancer and 10 types of exhaust and combustion products. All site-exposure combinations were investigated. An increased lung cancer risk, in particular squamous-cell cancers, due to exposure to gasoline and diesel exhausts was found. Among the associations that have not been subject to previous attention, the most promising leads for further investigation are the possible relations between gasoline and diesel exhaust and colorectal cancers, gasoline exhaust and kidney cancer, coal combustion products and pancreatic cancer (and possibly nonadenocarcinoma lung cancer), combustion products of heating oil and prostatic cancer, and natural-gas combustion products and bladder cancer.

Adult↗

First trimester diagnosis of adenosine deaminase deficiency.

Adenosine deaminase deficiency has been detected in the first trimester by direct analysis of enzyme activity in chorionic villi in a pregnancy at risk. Data for purine nucleoside phosphorylase activity in chorionic villi from healthy controls in the first trimester are also presented and should allow equally rapid diagnosis of this disorder.

Adenosine Deaminase↗

The appearance of compound cilia in the nasal mucosa of normal human subjects following acute, in vivo exposure to sulfur dioxide.

Electron microscopic examination of ultrathin sections of ciliated nasal epithelium obtained from seven normal, healthy human volunteers indicated increases in the prevalence of compound cilia following controlled, acute exposure to 0.75 ppm sulfur dioxide (SO2). Morphometric analyses of the specimens confirmed a statistically significant association between SO2 exposure and compounding of nasal epithelial cilia in four of the seven subjects. Concomitant freeze-fracture replicas prepared from these samples also revealed the occurrence of compound cilia with accompanying evidence of abnormal ciliary membrane ultrastructure in the nasal epithelium. These studies indicate that SO2 may be implicated as a causative agent in ciliary compounding in the upper respiratory tract and that compound cilia represent a form of acquired ciliary defect which may serve as a readily quantifiable marker of epithelial injury.

Cilia↗

The effect of ionizing radiation on advanced life support medications.

Advanced life support medications stored in emergency department stretcher areas, diagnostic radiology rooms, and radiotherapy suites are exposed to ionizing radiation. We hypothesized that radiation may decrease the potency and thus the shelf life of medications stored in these areas. Atropine, dopamine, epinephrine, and isoproterenol were exposed to a wide range of ionizing radiation. The potency of the four drugs was unaffected by levels of radiation found in ED stretcher areas and high-volume diagnostic radiograph rooms (eg, chest radiograph, computed tomography, fluoroscopy). The potency of atropine may be reduced by gamma radiation in high-use radiotherapy suites. However, dopamine, epinephrine, and isoproterenol were unaffected by high doses of gamma radiation. Atropine, dopamine, epinephrine, and isoproterenol may be safely kept in ED stretcher areas and diagnostic radiology rooms without loss of potency over the shelf life of the drugs.

Atropine↗

Marrow transplantation for acute nonlymphocytic leukemia following therapy for Hodgkin's disease.

Seven patients with acute nonlymphocytic leukemia (ANL) following therapy for Hodgkin's disease (HD) were treated with cyclophosphamide (Cy) alone or combined with 10.00 to 15.75 Gy total body irradiation (TBI) and marrow transplantation. Five patients were transplanted without an attempt at prior remission induction, one patient following failure of remission induction and one patient in first remission following successful induction. Four patients died of multiorgan failure, 15 to 70 days after transplant. Three patients died of progressive or recurrent leukemia 56, 120, and 280 days after transplant. These results illustrate the difficulty of treating patients for secondary leukemia with marrow transplantation and suggest that transplantation in the preleukemic phase should be studied.

Acute Disease↗

Proportionate mortality study of workers in the grain industry.

The proportionate mortality experience and proportionate cancer mortality experience were examined for 1,114 white male members of the American Federation of Grain Millers' life insurance plan. Mortality was significantly elevated for accidents and cancers of the lymphatic and hematopoietic systems, particularly from lymphosarcoma and reticulum cell sarcoma, other neoplasms of lymphoid tissue (i.e., giant follicular lymphoma and other primary malignant neoplasms of lymphoid tissue), and multiple myeloma. No increased mortality was seen for cancer of the respiratory tract, and nonmalignant diseases of the digestive tract were significantly lower than expected. Employees of grain mills showed higher mortality ratios of lymphatic and hematopoietic cancers as compared to other grain industry categories. A preliminary survey of pesticide usage suggested that grain mills were generally associated with greater use of pesticides than other industrial categories with considerable variation among the many facilities encompassed in this study.

Aged↗

CSF-CK activity.

Explore the source record for details and available documents.

Creatine Kinase↗

Cerebrospinal fluid gamma-aminobutyric acid levels in dogs with chronic portosystemic encephalopathy.

Cerebrospinal fluid (CSF) gamma-aminobutyric acid (GABA) levels were measured in a dog model of spontaneous chronic portosystemic encephalopathy. Dogs with congenital portacaval shunts (intra- or extra-hepatic) develop neurological features of abnormal psychomotor behaviour and depressed consciousness that are consistent with the symptoms of chronic portosystemic encephalopathy in humans. In the five dogs studied, plasma ammonia was elevated, as was CSF tryptophan, both usual biochemical abnormalities in portosystemic encephalopathy. CSF levels of GABA in five dogs with portosystemic encephalopathy (100 +/- 13 pmol/ml) were not significantly different from those in five control dogs (96 +/- 14 pmol/ml). CSF levels of GABA were not altered after ammonia infusion. If enhanced GABA-ergic neurotransmission, due to influx of gut-derived GABA into the brain, is responsible for the pathophysiology of chronic portosystemic encephalopathy in this model, it is not reflected by increased levels of GABA in CSF.

Ammonia↗

Measurement of the cross linking compound, pyridinoline, in urine as an index of collagen degradation in joint disease.

An enzyme linked immunoassay (ELISA) for the collagen cross link, pyridinoline, has been developed using affinity purified antibodies, with a sensitivity down to about 0.1 ng of cross link. Measurements of urinary pyridinoline were made in patients with rheumatoid arthritis (RA), osteoarthritis (OA), and a control group showing no signs of joint disease. Expressed relative to creatinine values, pyridinoline was significantly increased in both RA and OA groups compared with controls: these differences were much larger than could be attributed to any age related effects or to changes in urinary creatinine concentrations. These findings were confirmed by analysis of a series of 24 h urine collections which showed that the total pyridinoline excretions were significantly higher in both RA and OA groups than in the controls. As pyridinoline is much more prevalent in cartilage than in bone collagen, measurement of this compound in urine may provide an index for monitoring the increased joint destruction that occurs in arthritic disease.

Adult↗

Second marrow infusion for poor graft function after allogeneic marrow transplantation.

Fifty-seven patients undergoing allogeneic marrow transplantation had persistent poor graft function after transplant and received a second marrow infusion from the original donor. Eight donors were HLA-non-identical family members and 49 were HLA-identical siblings. Poor function of the initial graft occurred in the absence of demonstrable rejection or persistent malignancy. Preparative reconditioning was not given before the second marrow infusion. Thirty-four of the 57 patients survived more than 1 month after the boost and were evaluated for haematopoietic recovery. All 34 subsequently achieved a neutrophil count of more than 500 X 10(6)/l and 20 became independent of platelet transfusions. Forty-nine (86%) of the 57 patients demonstrated acute graft-versus-host disease (GVHD). In 24 of the 49 patients GVHD increased in severity (10 patients) or first appeared (14 patients) after the boost. Chronic GVHD developed in all of the 20 patients who survived more than 150 days after the second infusion. Currently, 10 patients survive (median follow-up of more than 5 years) and all have normal haematologic function. Although haematologic reconstitution and increased GVHD occurred in some patients receiving second marrow infusions, the relation of these outcomes to the marrow boost is unclear in the absence of a control group.

Adolescent↗