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Biomedical subjects

A Greenberg

Publications and source records attributed to A Greenberg.

At least 73 records · Page 4Linked to original sources

Toxicity of construction materials in the marine environment: a comparison of chromated-copper-arsenate-treated wood and recycled plastic.

Previous studies have demonstrated leaching from chromated-copper-arsenate (CCA)-treated wood, which is used in pilings and bulkheads, and resulting toxicity to various estuarine organisms. The current study compared effects of leachates from CCA-treated wood with those of recycled plastic "lumber," a possible alternative construction material. Limb regeneration in fiddler crabs, while depressed in leachates from CCA wood, was accelerated in three formulations of recycled plastics. The acceleration was reduced in subsequent trials with the same pieces of plastic. Using a sea urchin fertilization test, no effects were seen in 1- and 3-day leachates from the plastics. However, CCA wood reduced fertilization by 90%, and totally inhibited larval development of those that did fertilize. A smaller piece of wood, one-tenth the size (0.4 cm2), did not have a significant effect on fertilization or development. With 1-3 weeks of leaching, significant reductions in fertilization were seen in sea urchin gametes exposed to one plastic formulation and no fertilization was seen in leachates from the small piece of CCA wood. Two formulations enriched to 30% polystyrene (PS) had no significant effect on fertilization, but did reduce larval growth. When the same pieces of plastic and wood were used for a second set of experiments, all three formulations of plastic, as well as the small piece of wood, inhibited fertilization significantly, and one of the 30% PS formulations and the wood caused reduced larval growth. In another assay, snails and an alga were exposed to plastics for two months with no observed effect; the CCA leachates caused 100% snail mortality within one week and chlorosis of the alga.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Phase II trial of fludarabine phosphate for adenocarcinoma of the pancreas. An Illinois Cancer Center study.

We have conducted a phase II trial of fludarabine phosphate for advanced measurable adenocarcinoma of the pancreas. The drug was administered every 4 weeks by a daily-times-5 bolus schedule beginning at 20 mg/m2/day. No responses were observed in 20 evaluable patients, 18 of whom were previously untreated. Dose-limiting toxicity was leukopenia, and gastroenterologic side effects were frequent. Life-threatening or fatal renal dysfunction occurred in 3 patients. In this schedule fludarabine phosphate is ineffective against adenocarcinoma of the pancreas and appears to have unpredictable severe renal toxicity.

Adenocarcinoma↗

Hemoperitoneum complicating chronic peritoneal dialysis: single-center experience and literature review.

Hemoperitoneum is a well-recognized, if uncommon, complication of chronic peritoneal dialysis. In this review of 424 patients maintained on peritoneal dialysis at a single center during an 11-year period, 26 patients (6.1%) developed one or more episodes of hemoperitoneum. Three patients had hemoperitoneum on two separate occasions with different etiologies. One additional patient was seen on a hospital consultative service. Three types of bleeding episodes were observed. Twenty-one of 30 (70%) were benign, consisting of pink-tinged dialysate with little clinical consequence (group 1). Three (10%) consisted of minor hemoperitoneum associated with significant intra-abdominal pathology (group 2), and six (20%) required active intervention (group 3). The most frequent cause of hemoperitoneum was bleeding related to menstruation or ovulation; hemoperitoneum was more common in women than in men. Two patients had hemoperitoneum occurring after more than 6 years on dialysis. In both, the etiology was sclerosing peritonitis, an association not previously noted. The less common etiologies of hemoperitoneum encountered in our patients were similar to those in reports from other centers and are compiled here.

Female↗

Bulimia in opiate-addicted women: developmental cousin and relapse factor.

There has been a growing awareness that eating disorders and substance abuse may coexist in the same individual. While several studies have documented the prevalence of these problems, few have addressed their relationship in the recovering patient. In the present study, the charts and hospital course of all female patients admitted to an inpatient treatment program for opiate dependency were reviewed. Approximately 20% of the patients had bulimic pathology that predated the drug abuse and re-emerged during detoxification. A theoretical model is presented which examines the possible developmental interplay between the two disorders and the role that renewed food problems may serve as a prodrome for relapse. The difficulty in addressing these issues during both the assessment and treatment phases of recovery is also discussed.

Adult↗

Analysis of human exposure to benzo(a)pyrene via inhalation and food ingestion in the Total Human Environmental Exposure Study (THEES).

The Total Human Environmental Exposure Study (THEES) focuses on benzo(a)pyrene (BaP) as an example of a combustion-generated polycyclic aromatic hydrocarbon (PAH) compound. Primary pathways for environmental exposures to BaP are inhalation and ingestion. This program of field studies was conducted in Phillipsburg, New Jersey, a small, industrial city in the Delaware River valley. The study protocols included direct monitoring of BaP exposures via inhalation and ingestion pathways during three separate periods, each lasting 14 days. BaP concentrations in air were sampled at outdoor and in-home locations, with personal air sampling added during the latter two phases. Cooked food samples from each household were acquired, using a constant portion "second plate" of each meal prepared at home. Ambient levels were 4-10 times higher during the cold months compared with the late summer study period. Space heating and regional aerosol were major contributors to community levels of BaP in the air during the wintertime. Penetration of outdoor air, cooking activities, combustion appliances, and cigarette smoke were important sources of indoor air exposures. Cooking activities, besides releasing BaP-enriched particles indoors, produced food imbued with BaP and added substantially to exposure via the ingestion route. Among the study subjects, the range and magnitude of dietary exposures (2 to 500 ng/d) were much greater than for inhalation (10 to 50 ng/d). Nevertheless, there were ample individual cases where inhalation of BaP was the predominant exposure route. Indoor air BaP levels were closely correlated with ambient levels in most of the homes. For some individuals, measured personal air BaP exposures were adequately predicted by time-weighting of microenvironmental (i.e., outdoor and in-home) concentrations. However, enormously high exposures for ingestion or inhalation were detected only by direct observation, not from microenvironmental data.

Administration, Inhalation↗

Catecholamine determination in sequential urine voiding: a method for detecting pheochromocytoma in patients without elevated urinary catecholamines.

The biochemical diagnosis of pheochromocytoma is based on the demonstration of increased amounts of catecholamines, or catecholamine metabolites, in 24-h urine samples. In patients whose 24-h urine catecholamines are within normal limits, and in whom short duration catecholamine elevations are suspected, timed urine collections have been used to detect these elevations. In this study, determination of catecholamines in sequential urine voidings and consideration of their relative values are suggested as a further method to detect pheochromocytomas, especially in cases without extended elevation of urinary catecholamine levels. The use of this method is demonstrated in three cases in which pheochromocytoma would not otherwise have been proven by laboratory determination.

Adrenal Gland Neoplasms↗

Resolution of cirrhotic glomerulonephritis following successful liver transplantation.

A 38-year-old man with liver failure due to Laennec's cirrhosis developed nephrotic range proteinuria and hematuria. Renal biopsy showed membranoproliferative glomerulonephritis with 2+ staining for IgA and complement consistent with cirrhotic glomerulonephritis. After orthotopic liver transplantation, proteinuria and hematuria rapidly resolved. This case indicates that glomerulonephritis associated with cirrhosis may be successfully treated with hepatic transplantation. Whether the improvement in glomerular abnormalities resulted from immunosuppression therapy or from restoration of normal hepatic function is unknown.

Adult↗

Biological monitoring for occupational cadmium exposure: the urinary metallothionein.

The relationship between urinary metallothionein and kidney and liver cadmium levels was examined in 68 active and retired smelter workers. Metallothionein was analyzed by a radioimmunoassay and liver and kidney cadmium levels were determined by in vivo neutron activation. Four workers suffered from severe renal dysfunction and excreted high amounts of total protein and beta 2-microglobulin and greater than 1 mg metallothionein/g creatinine. In the remaining 64 workers the urinary metallothionein levels correlated significantly with the cadmium levels in both liver and kidney. Similarly, in these individuals urinary metallothionein was significantly related to cadmium in blood and urine. These results demonstrate that urinary metallothionein is a sensitive biological indicator of cadmium exposure and body burden, before the onset of severe renal dysfunction.

Adult↗

Cyclosporine nephrotoxicity in cardiac allograft patients--a seven-year follow-up.

Renal function was observed retrospectively in a population of 228 adults who underwent a cardiac allograft at the University of Pittsburgh from June 1980 through June 1987, survived a minimum of one year, and received cyclosporine. Renal function was determined by serial measurement of serum creatinine concentration. Serum creatinine rose from 1.2 +/- 0.0 mg/dl at time of hospital discharge to 2.0 +/- 0.0 mg/dl at two and four years and 3.3 +/- 0.1 mg/dl at seven years. The fall in renal function was biphasic, with a rapid decline (reciprocal creatinine slope -0.018 dl/mg-mo) through 24 months and a slower decline thereafter -0.0036 dl/mg/month). This occurred despite a progressive decrease in cyclosporine levels from 668 +/- 23 ng/ml (whole blood RIA) to 380 +/- 12 ng/ml at seven years. Three of 222 patients (1.6%) developed end-stage renal disease within 18 months of initiation of cyclosporine therapy. Only one additional patient of 26 followed through 54 months (3.8%) developed end-stage disease thereafter. The decline in renal function seen with cyclosporine is rapid in the first 18 months, with a slower but continuing decline seen with later follow up. At least in heart transplantation, the risk of end-stage renal disease is significant, but not prohibitive.

Adult↗

Factors associated with human exposures to polycyclic aromatic hydrocarbons.

The number and quantities of PAH emitted and accumulated within various environmental media require the development and application of new methods for determining the major routes of exposure to individual and selected compounds. From research that has been conducted on airborne BaP and other selected PAH it appears that they can accumulate indoors as well as outdoors. Smoking seems to be a major contributor for direct and passive inhalation, but the role of cooking and wood burning related to indoor emissions needs to be investigated further. The available data indicate that many PAH will be distributed between both particles and the gas phase. Therefore, new techniques for simultaneously sampling PAH in both phases are required for the indoor environment and personal monitoring studies. These will increase our understanding of the distribution of each component and increase the accuracy of exposure and risk assessments conducted for Total PAH. A strategy (THEES) has been developed for the measurement of BaP exposure from multiple pathways. It should be extended to other PAH, which will assist in quantifying the significance of indoor air related exposures. The inhalation exposures could be derived from indoor combustion sources, penetration of outdoor air indoors, and personal activities, such as cooking and smoking. The reactivity of PAH requires further investigation, since it appears that a number of nitro-PAH will be produced. Some of the resulting compounds will need to be factored into PAH exposure assessments.

Air Pollutants↗

Extinction of expression of the translocated myc gene in somatic cell hybrids between mouse myeloma and L-cells.

Most murine plasma-cell tumors show a t(12;15) reciprocal chromosomal translocation which truncates the first exon of one of the myc gene alleles and fuses it to one of the switch regions of the immunoglobulin (Ig) heavy-chain locus. This results in constitutive activation of the translocated myc gene and the production of smaller-sized mRNA molecules, which are initiated at new sites in the first myc intron. The normal myc allele is not expressed in these myeloma cells. We have studied the expression of the translocated myc gene in somatic cell hybrids between mouse myeloma and L-cells. Our previous findings show that Ig gene expression is extinguished in such hybrids. In the present work we found that the hybrids contain the normal and translocated myc genes. In contrast to the myeloma parental cells which express the translocated myc gene, the hybrids are similar to the L-cells in expressing only the normal myc allele. Our results suggest that the L-cell, fibroblast-like phenotype, is dominant in these hybrids, and show that the translocated myc gene is expressed in a tissue-specific manner in the context of the myeloma cell, and is not expressed when subjected to a fibroblast-like cellular environment.

Alleles↗

Atheroembolic involvement of renal allografts.

Renal atheroembolism is a well-recognized cause of renal insufficiency. Two renal allograft recipients with cholesterol atheroemboli in their allograft biopsies are described. In one patient, the origin of the atheroemboli was the recipient aorta while in the second patient the source was the donor. Renal allograft atheroembolism should be considered in elderly recipients or recipients of kidneys from older donors.

Adult↗

Hypercalcemia in patients with advanced chronic renal failure not yet requiring dialysis.

Six patients with progressive chronic renal failure not yet requiring dialysis and not consuming supplemental calcium or vitamin D developed hypercalcemia. Three had proven and 1 suspected tertiary hyperparathyroidism, 1 parathyroid carcinoma and 1 aplastic bone. None of the 3 patients who underwent bone biopsy had heavy bone aluminum staining. The patients with proven parathyroid-mediated hypercalcemia had marked elevation of C-terminal parathyroid hormone and alkaline phosphatase values and, when performed, radiographs consistent with osteitis fibrosa. When these findings are absent or the diagnosis is otherwise uncertain, a bone biopsy may provide a definitive diagnosis and guide management.

Adult↗