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Biomedical subjects

J Epstein

Publications and source records attributed to J Epstein.

At least 73 records · Page 4Linked to original sources
PubMed1997

Postradiation osteonecrosis of the mandible: a long-term follow-up study.

OBJECTIVES: The objective of this study was to assess the long-term progress of 26 patients who experienced postradiation osteonecrosis of the jaw between 1975 and 1989. STUDY DESIGN: Of 26 patients who had been previously managed with hyperbaric oxygen therapy as a part of their treatment for postradiation osteonecrosis of the jaw, 20 were evaluated to determine their current status of the condition: resolved, chronic persisting (unresolved), or active progressive (symptomatic). RESULTS: Two of 20 patients experienced recurrences of the condition. In one of these patients, surgical treatment was identified as the stimulus of postradiation osteonecrosis. In the other patient, the recurrence appeared to be related to periodontal disease activity. In 60% (12 of 20) of the patients, the condition remained resolved, improvement in clinical staging occurred in 10% (2 of 20) (from symptomatic to unresolved or resolved), and 20% (5 of 20) of the patients continued to demonstrate chronic persisting postradiation osteonecrosis at the end of the long-term follow-up period. CONCLUSION: This study supports the contention that postradiation osteonecrosis can occur at any time after radiation therapy, and that patients remain at risk up to 231 months after treatment of the cancer and probably indefinitely after radiation therapy. Our findings also suggest that risk of second episodes of the condition after management of an initial episode is low. In addition, our follow-up study revealed that chronic nonprogressive postradiation osteonecrosis can remain stable without extensive intervention including combined hyperbaric oxygen therapy and surgery.

Adult↗
PubMed1997

The drug abuse treatment gap: recent estimates.

There is a widely acknowledged problem of drug abuse in the United States, but there is no widely accepted estimate of the number who need treatment for drug abuse. In this article, the authors present new estimates of the numbers of persons in this country who need and receive treatment. These estimates are derived from improved definitions and statistical estimating methods applied to the national Household Survey on Drug Abuse (NHSDS). There are two separate estimates (based on severity) of people needing treatment, yielding a combined total of 7.1 million people. These new estimates are crucial to better resource planning and allocation.

Data Collection↗
PubMed1997

Biology and therapy of multiple myeloma in 1996.

Since the introduction of melphalan-prednisone for the treatment of multiple myeloma (MM) three decades ago, the prognosis of patients has not been improved by the addition of other agents, probably due to marked resistance of tumor cells, even at diagnosis, to commonly employed cytotoxic drugs. The biological basis for drug resistance is reviewed and current methods of diagnosis and staging delineated. The overview on treatment focuses on recurrent advances with myeloablative therapy demonstrating, in randomized and historically controlled trials, that high-dose therapy increases the incidence of true complete remission (CR) from 5% to approximately 40%, with an extension of median event-free (EFS) and overall (OS) survival durations to 3.5 and > or = 5 years, respectively. It is concluded that high-dose therapy should be offered to all patients with symptomatic meyloma, and current therapeutic research explores posttransplant immunotherapy.

Antineoplastic Agents↗
PubMed1997

Latex allergies in dentistry: recognition and recommendations.

Latex allergies have been increasing in the health-care setting since the introduction of universal precautions in the early 1980s. Given the number of sensitized individuals, and assuming this number will rise with increasing exposure to latex, an efficient latex protocol should be implemented in dental offices. Patients should be screened by taking a detailed medical history, and precautions should be used when treating individuals at high risk for developing latex allergies. These precautions should be continued until an allergist has verified the patient's allergic status, and ruled out latex allergy as a concern.

Dental Equipment↗
PubMed1997

The use of external data sources and ratio estimation to improve estimates of hardcore drug use from the NHSDA.

Levels of hardcore drug use have been especially difficult to estimate because of the relative rarity of the behavior, the difficulty of locating hardcore drug users, and the tendency to underreport stigmatized behavior. This chapter presents a new application of ratio estimation, combining sample data from the National Household Survey on Drug Abuse (NHSDA) together with population counts of the number of persons arrested in the past year from the Uniform Crime Report (UCR) and the number of persons in drug treatment programs in the past year from the National Drug and Alcoholism Treatment Unit Survey (NDATUS). The population counts serve as a benchmark accounting for undercoverage and underreporting of hard drug users.

Cocaine↗
PubMed1996

Senescent fibroblasts as feeder cells for lymphoid cell cloning.

Senescent primary human skin fibroblasts were used as feeder layers for cloning lymphoid cells by limiting dilution. B-cells including mouse hybridoma cells, human multiple myeloma cells C1R and DIG, as well as an immortalized T-cell line (Jurkat cells) were cloned using this approach. From heterogenous populations, homogeneous (clonal) populations were obtained and further analyzed. The major advantages of senescent fibroblasts as feeder cells are (i) the need to establish primary cultures from experimental animals for preparing feeder cells is obviated; (ii) the risk of contamination with infectious agents is diminished; (iii) primary skin fibroblasts are easily maintained in culture, can be kept at confluence for extended periods of time, and do not undergo spontaneous transformation; and (iv) lymphoid cells are readily separated from fibroblast monolayers. The use of senescent fibroblasts overcomes limitations inherent with primary mouse cell cultures and irradiated cells commonly used as feeder cells in cloning techniques.

Animals↗
PubMed1996

Circulating clonal lymphocytes in myeloma constitute a minor subpopulation of B cells.

The mononuclear cells in the blood of myeloma patients have been reported to contain a high proportion of phenotypically abnormal myeloma B lymphocytes. These cells have been proposed to constitute the drug-resistant proliferative myeloma cell compartment. To determine the extent of B lymphocyte involvement, the proportion of clonotypic cells among the CD19-expressing cells from myeloma patients was estimated by quantitative polymerase chain reaction analysis of the third complementarity determining region (CDR3). The results indicate that the B lymphocytes constitute, on average, 6% of blood mononuclear cells, and that only a minor fraction of these are clonally related to the myeloma cells. While the small number of circulating clonal cells is not incompatible with their proposed role as a reservoir of proliferating myeloma progenitors, the majority of the B cells appear not to be clonally related to the myeloma cells.

Antigens, CD19↗
PubMed1996

The collectins in innate immunity.

The collectins are proteins with collagen tails and globular lectin domains that appear to play an important role in mammalian first line host defense. Recent insights have clarified the structural basis of ligand recognition, the interactions of collectins with complement cascades, and the association with disease susceptibility.

Animals↗
PubMed1995

Nuclear morphometric analysis of metastasis in Wilms' tumor after multimodal therapy: comparison with primary tumor.

OBJECTIVES: The outlook for children with Wilms' tumor has improved with the use of multimodal therapy, and survival rates now exceed 85%. Yet, 15% of children with tumors with favorable histologic findings continue to recur unpredictably. We previously reported that nuclear morphometry (the distribution of nuclear roundness factor [NRF], lowest values for ellipticity, and age) when combined in a multivariate analysis accurately predicted response to therapy for patients with histologically favorable Wilms' tumors. METHODS: To investigate further the nuclear shape changes associated with disease recurrence, we analyzed histologic sections taken from primary tumors and postmultimodal therapy metastatic lesions for 7 children who had a recurrence with initially histologically favorable primary tumors. RESULTS: Mean NRF was significantly lower (P = 0.0001) in the metastatic lesion (35 +/- 5) group when compared with the primary tumor group (50 +/- 5). The percent coefficient of variation for NRF was also significantly lower (P = 0.006) in the metastatic lesion when compared with the primary tumor. Nuclear area was increased (P = 0.02), although the nuclear perimeter was unchanged (P = 0.1). CONCLUSIONS: (1) Nuclei in metastatic lesions from Wilms' tumors with favorable histologic findings after multimodal therapy are more round and exhibit less variable distribution, suggesting clonal homogeneity within the metastatic lesion. (2) Nuclei in the metastatic lesions have greater area than in the primary tumors yet have an unchanged perimeter, which may be due to internal nuclear expansion secondary to increased cellular deoxyribonucleic acid (DNA) ploidy. Although the results of this study are promising, we are currently extending this hypothesis to a larger group of patients.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1995

Biological aspects of multiple myeloma.

Although considerable progress has been made towards understanding many aspects of myeloma, the myeloma stem cell and the factors that drive the disease remain elusive. Recent developments in the molecular analysis of clonality have helped to confirm the presence of pre-switch B cells that are of the same clone as the myeloma plasma cells. The role of these cells in myelomagenesis has not been demonstrated, and the isotypic heterogeneity of the clonally-relevant cells suggests that the pre-switch B cells are pre-malignant progenitors of the tumour cells. Thus, the circulating clonal B cells appear to be the earliest progenitors of the mature, monoclonal plasma cells. IL-6, and possibly other cytokines, are involved in driving this process. The role of IL-6 in myeloma is complex and more involved than its proposed growth factor function. In the absence of IL-6, dependent cells become apoptotic. Increased IL-6 signalling also leads to apoptosis of myeloma cells, possibly as a result of terminal differentiation. In the presence of exogenous IL-6, the IL-6 receptor appears to be the rate-limiting factor in the pathway's activity. IL-6 may regulate the survival of myeloma cells by stimulating c-myc transcription, possibly from the P0 promoter. The high levels of c-myc transcripts and protein could regulate myeloma cell proliferation and apoptotic death by controlling p53 expression and, through it, the expression of the Rb and BAX genes. Proliferative signalling in myeloma cells is likely to be intrinsic, within the tumour cell compartment. Molecules such as CD28 and B7, both expressed by less mature myeloma cells, could represent one such self-self stimulatory mechanism, with IL-6, possibly through stimulation of c-myc expression, providing the signals for survival and differentiation.

B7-1 Antigen↗