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S Lessin

Publications and source records attributed to S Lessin.

15 recordsLinked to original sources
PubMed2005

Pleiotrophin expression correlates with melanocytic tumor progression and metastatic potential.

BACKGROUND: Gene expression profiling of melanoma and nevic tissue has demonstrated that pleiotrophin (PTN) is significantly overexpressed in human melanomas. METHODS: To further evaluate PTN expression in melanocytic lesions, protein immunohistochemistry was performed on the spectrum of melanocytic lesions. RESULTS: Melanocytic nevi were consistently negative (n=58). In contrast, the great majority of metastatic melanomas were positive (33/34, 97%). The analysis of 34 primary melanomas demonstrated PTN positivity in 20 lesions while 14 lesions were negative. Within the primary melanomas, PTN immunoreactivity was associated with metastasis (p=0.0004) and decreased melanoma-related survival (p=0.0444). Univariate analysis of PTN immunoreactivity predicted an increased risk for metastasis (relative risk 9.1, p=0.003). CONCLUSIONS: The results of this study confirm previous gene profiling data showing differential PTN expression between melanocytic nevi and melanomas. In addition, lesional PTN expression is associated with metastatic potential and may be a prognostic factor for melanomas.

Adult↗
PubMed1998

Radiotherapy for unilesional mycosis fungoides.

PURPOSE: To evaluate the treatment outcome and natural history of patients with the diagnosis of unilesional mycosis fungoides, treated according to a prospective radiotherapy protocol in our institution since July 1975. METHODS AND MATERIALS: A total of 325 patients with the diagnosis of mycosis fungoides have been referred to the Department of Radiation Oncology at Allegheny University of Health Sciences from July 1975 through September 1996. Of these, 18 patients (5%) were classified as having unilesional mycosis fungoides and were irradiated with a curative intent using local electron fields. One patient received 22 Gy; 1 patient received 40 Gy, and the rest of the patients 30.6 Gy. Daily fractions ranged from 1.8 to 2.0 Gy. Treatments prior to radiation consisted of topical steroids and/or antifungal creams in the majority of patients, with temporary partial responses. One patient had received 2 years of topical mechlorethamine (HN2) and another patient had received topical carmustine solution (BCNU) without response prior to irradiation. RESULTS: The responses were measured clinically; posttreatment skin biopsy was not performed routinely unless there was clinical evidence of disease persistence. Complete response rate was 100%; all treated lesions cleared completely within 4 to 8 weeks after the completion of radiation. With a median follow-up of 43 months (range 12 to 240 months), 2 relapses have occurred, 2 and 71 months after the completion of radiation. Both relapses were confined to the skin and were remote from the original site. Both relapses responded to topical application of HN2. There have been no recurrences in the irradiated field nor systemic dissemination. No long-term side effects were found related to treatment, and all the patients are currently alive and without evidence of disease. Actuarial relapse-free and overall survival at 10 years are, respectively, 86.2% and 100%. CONCLUSION: Unilesional mycosis fungoides has a long natural history, is possibly the earliest manifestation of a malignant process, and local treatments, including local radiotherapy, result in long-term disease-free intervals and, possibly, cure. Total skin electron beam radiotherapy is not indicated for this disease entity.

Adult↗
PubMed1991

A clonal CD4-positive T-cell line established from the blood of a patient with Sézary syndrome.

The reported inability to establish long-term T-cell lines from the blood of cutaneous T-cell lymphoma patients with circulating neoplastic T cells has hindered the development of an in vitro system to investigate Sézary syndrome. We have established a rapidly proliferating T-cell line from the peripheral blood of a patient with Sézary syndrome, which expresses a mature helper T-cell phenotype and contains cytogenetic abnormalities and T-cell receptor gene rearrangements identical to those in the patient's blood. The method of establishment and characteristics of this line are described.

Aged↗
PubMed1990

Expression and function of gamma delta- and alpha beta-T cell receptor heterodimers on human somatic T cell hybrids.

T cell somatic hybrids were obtained by fusion of human tetanus toxoid-specific gamma + delta + T cells and a T cell lymphoma cell line that expresses beta-chain but not alpha-chain transcripts. The hybrids simultaneously and independently expressed alpha beta and gamma delta TCR heterodimers on the cell surface without any significant differences in the level of expression. No heterodimers containing alpha delta-, beta delta-, beta gamma-, and alpha gamma-chains were transported to the cell membrane, indicating a chain specificity in dimer formation. The presence of productively rearranged gamma- and delta-alleles in the hybrid cells and immunoprecipitation of an identical type of TCR-gamma delta from both hybrid and parental gamma + delta + T cells suggests that TCR-gamma delta on the hybrid cells derives from gamma + delta + T cells. Anti-TCR (TCS-delta 1 or WT31) and anti-CD3 antibodies induced a rapid increase in [Ca2+]i in the double-positive hybrids and their variants positive for either the alpha beta or gamma delta complex. Double positive hybrid cells were refractory to stimulation with anti-CD3 antibody after pretreatment with a mixture of anti-TCR-gamma delta and anti-TCR-alpha beta antibodies but not with either antibody alone indicating the functional independence of the two receptors. However, only gamma delta heterodimer receptor was able to respond to tetanus toxoid presented on autologous APC as measured by induction of the p55 chain of IL-2R on stimulated cells.

Alleles↗
PubMed1988

Epidermal plasminogen activator is abnormal in cutaneous lesions.

To investigate the role of plasminogen activator (PA) in cutaneous disease, we have used biochemical and immunocytochemical techniques to examine PA in normal and lesional skin. In normal human dermis, tissue PA is the predominant PA activity; however, in normal epidermis, urokinase type PA is the predominant PA activity. In contrast, PA activity in epidermis from lesions of patients with a variety of cutaneous diseases was predominantly tissue type enzyme with a much smaller contribution from urokinase. Our patient population included individuals with benign chronic pemphigus, pemphigus vulgaris, pemphigus foliaceous, bullous pemphigoid, or psoriasis. Using rabbit antibody specific for tissue type PA, we have immunocytochemically localized this enzyme in lesions from individuals with the above disorders. Our results indicate that tissue PA is consistently elevated in cutaneous lesions with diverse etiology, pathology, and clinical presentation.

Adult↗
PubMed1984

Multichannel communication in normal and delinquent families.

Families containing adjudicated delinquents or nondisturbed adolescents were engaged in a laboratory interaction procedure aimed at assessing inconsistent (nonredundant) verbal-nonverbal communication patterns. Detailed analyses of verbal, facial, and auditory channels indicated higher rates of positive nonverbal, negative verbal communications in control versus delinquent families and in parent-parent versus parent-child interaction. Results are discussed in terms of the potential adaptive characteristics of such "positive inconsistent" communications.

Adolescent↗
PubMed1980

FPi analysis. II. Use of the method to monitor the in vivo kinetics of cell populations perturbed by hydroxyurea.

In a previous report, we described a new method called FPi analysis to analyze time sequences of DNA histograms taken from a perturbed population of cells. In this paper we utilize the method to analyze the in vivo kinetic response of bone marrow and of lung metastases of the B16 tumor to various chemotherapeutic agents. We show that the technique allows useful kinetic data to be obtained with minimal processing of the raw histograms, thus allowing fast analysis of the data. We also show that, in order to monitor the kinetic response of living tissues, it is essential to collect multiparameter distributions; to monitor only the one dimensional fluorescence histogram can give rise to misleading results. Using these multiparameter histograms, we are also able to monitor the growth fraction of the lung metastases during treatment, allowing discrimination between cell synchrony and cell recruitment from the resting compartment.

Animals↗
PubMed1979

Verbal-nonverbal congruence in normal and delinquent families.

Assessed affect expression for both normal and delinquent families (N = 5 families) in three communication channels (verbal, tonal and facial); group differences in channel inconsistency were determined. Interactions that involved mother-father, mother-son, and father-son were assessed independently. Analysis of variance procedures yielded a number of group differences in total affect expression and verbal-nonverbal inconsistency. When co-variance procedures controlled for demographic differences, however, reliable differences between normal and delinquent families no longer obtained. Findings are discussed in terms of results from previous encoding studies and the relationships among affect expression, diagnostic status, and demographic variations.

Adolescent↗
PubMed1979

Morphometric analysis of B2cAMP induced reverse transformation in synchronized CHO cells.

Synchronized tranformed and reverse-transformed (by 10(-3) M B2cAMP) CHO-K1 cells, growing adherent to plastic, are characterized by means of geometric and densitometric parameters at the level of both the entire cell and of the nuclei at various time intervals after selective miotic detachment. Transformed and reverse-transformed cells triple-stained with Feulgen, Napthol Yellow S, and periodic acid-Schiff appeared very similar in terms of integrated optical density (IOD), related to either polysaccharides, protein, or DNA amount. On the other hand, a shift from a polygonal to a spindle-shaped morphology is a accompanied by a significant decrease in both form factor and average optical density (AOD) of intact cell and nuclei, which are the most conspicuous measured changes caused by B2cAMP, in addition to a lengthening of the cell cycle duration. In both control and treated cells, important and parallel cell-cycle-dependent modulations of geometric and densitometric parameters are also observed, for both the cytoplasmic (i.e., cell morphometry) and DNA space (i e., nuclear morphometry). Specifically, the modulation in nulear morphometry during G1, S, G2, and M phases confirms previous findings on synchronized HeLa cells. The optical density threshold-dependence of geometric parameters shows that, while becoming fusiform, the cytoplasm of reverse-transformed cells had a particularly low optical density precisely in the polar area. Utilization of such an approach in the development of an objective morphological classification of all cell lines grown as monolayers "in vitro" is also discussed.

Animals↗
PubMed1979

Mass action and acridine orange staining: static and flow cytofluorometry.

We present results involving an approach to acridine orange staining of intact cells based on basic physicochemical considerations. We show by static microfluorometry of several in vitro and in vivo cell lines that the important parameters for such staining are the molar ratio (Formula: see text), and molar concentration of acridine orange. Differential nuclear DNA and cytoplasmic RNA staining are totally controlled by these two parameters. We show this by a physicochemical model of cell-dye interaction. Finally, we use the method to study the growth parameters of complex in vivo cell populations by automated multiparameter flow microfluorometry. We have explored also, both by static and flow systems, the effect on AO-cell staining of various cell pretreatments such as Triton X-100 and chelating agents.

Acridine Orange↗
PubMed1979

Early detection of micrometastases via flow microfluorimetry.

We show that by measuring the joint distribution of fluorescent and scattered light in a suspension of lung taken from the C57B1/6J mouse, we are able to discriminate in vivo between the lung metastases of the B16 melanoma and the normal lung tissue. We can in such a way detect metastatic cells in a very early stage of growth and also obtain growth curves for the metastatic population. We analyze the sensitivity of the method of detection and speculate how it might be used in aiding in human diagnosis.

Animals↗
PubMed1975

Hormonal regulation of isoenzymes of N-acetyl-beta-glucosaminidase and beta-galactosidase during spermatogenesis in the rat.

Isoenzymes of beta-galactosidase and of N-acetyl-beta-glucosaminidase were assayed during development of rat testis and as a function of hormonal treatments. Isoenzyme 1 of beta-galactosidase was highest in specific activity in the 4-day-old testis, at a point when Sertoli cells and gonocytes were the predominant cell type. Beta-galactosidase II, previously shown to be associated with the sperm acrosome, was undetectable through the spermatocyte stage of development, but increased in specific activity during the formation of spermatids. The specific activities of isoenzymes I and II of N-acetyl-beta-glucosaminidase increased markedly in association with the formation of spermatogonia and spermatocytes, and then declined with the appearance of spermatids. Following hypophysectomy of rats at 26 days of age or in adulthood the specific activities of the lysosomal enzymes beta-galactosidase I and N-acetyl-beta-glucosaminidase I and II increased markedly, while the acrosomal beta-galactosidase II was undetectable. The normal patterns of isoenzyme distributed were restored completely by administration of LH and FSH or testosterone to hypophysectomized animals. These results thus demonstrate specific patterns of isoenzyme concentration during spermatogenesis. Formation of the acrosome in developing spermatids is associated with the induction of new forms of beta-galactosidase (isoenzyme II) and N-acetyl-beta-glucosaminidase (sperm isoenzyme). These molecules appear to be specialized forms which may participate in fertilization, and their induction is dependent upon the actions of gonadotropins or testosterone.

Animals↗