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Biomedical subjects

M Berman

Publications and source records attributed to M Berman.

At least 37 records · Page 2Linked to original sources
PubMed1991

A naturally occurring 6-9-kilodalton interleukin-1 (IL-1) inhibitor prevents IL-1-mediated islet cytotoxicity but not IL-1-mediated suppression of insulin secretion.

Earlier studies have shown direct effects of interleukin-1 (IL-1) on isolated pancreatic islets. Coculture of isolated rat pancreatic islets with human rIL-1 beta for 6 days resulted in dose-dependent cytotoxicity (up to 100%) and suppression of insulin secretion (up to 88.5%). The cytotoxic effects of rIL-1 beta beta were blocked by the simultaneous presence of a naturally occurring 6-9-kilodalton (kDa) inhibitor of IL-1-induced T-cell proliferation. However, the ability of rIL-1 beta to suppress insulin secretion was not blocked by the 6-9-kDa inhibitor of IL-1 activity. This IL-1 inhibitor is produced by mononuclear cells and is resistant to pH 2, sensitive to heating at 56 degrees C for 30 min, has a pI of 4.5-5.6, and appears to be different from other recognized IL-1 inhibitors in both composition and mechanism of action. Unlike this IL-1 inhibitor, a monoclonal antibody specific for rIL-1 beta was able to neutralize both the islet cytotoxic and insulin modulatory effects of rIL-1 beta. These results demonstrate the use of an IL-1 inhibitor to prevent at least one mechanism of islet destruction, and suggest separate pathways for IL-1 mediated islet cytotoxicity and suppression of insulin secretion.

Animals↗
PubMed1991

Pathogenesis of corneal epithelial defects: role of plasminogen activator.

Previous studies have suggested that the plasminogen activator (PA)/plasmin system has important roles in the pathogenesis of epithelial defects and stromal ulceration. The current studies were performed to localize PA species and identify them as tissue-type PA (tPA) or urokinase-like PA (uPA) as the two have distinct regulatory properties potentially related to the mechanisms of defect formation and ulceration. To determine the locations and types of PA species, antibodies to tPA or to uPA or the drug amiloride (a drug that inhibits uPA but not tPA) were incorporated into fibrin/fibronectin (Fn) clots overlying frozen sections to block regional fibrinolysis. Normal rabbit eyes showed tPA activity in association with corneal epithelium, corneal endothelium, and ciliary body/iris. After epithelial scrape or alkali burn, corneal tPA activity was detected initially in the defect zone colinear with fibrin/Fn and was symmetrical to resurfacing epithelium. The observation that initial fibrinolysis occurs in the defect zone, known to contain fibrin/Fn, suggests that tPA from blood (limbal vascular endothelium) and/or from corneal epithelium has become bound to (and activated on) the fibrin/Fn. PA activity was also associated with the leading edges of migrating epithelium post-scrape and post-burn and was not inhibited by antibodies to either tPA or uPA but was inhibited by amiloride. After complete closure of the primary defect post-scrape, only tPA appeared to be associated with the epithelium in that all PA activity was inhibited by antibodies to tPA. The observation that leading edge activity post-burn, in correlation with the formation of secondary defects, continues to be inhibitable by amiloride but not by antibodies to tPA suggests that uPA remains abnormally on the leading edge, and that sustained uPA activity in that location results in inappropriate degradation of subepithelial fibrin/Fn to result in a defect. Successful regulation of uPA activity at the leading edge of corneal epithelium post-burn would be expected to be useful therapeutically in the healing of epithelial defects and the prevention of stromal ulceration.

Animals↗
PubMed1990

New passive perfusion PTCA catheter.

Percutaneous coronary angioplasty with a new passive perfusion balloon catheter was compared to a standard angioplasty balloon catheter during prolonged balloon inflations in miniature swine. Inflations with the passive perfusion balloon were alternated with a standard balloon with the initial balloon chosen randomly in 24 coronary arteries. End-points for terminating the balloon inflation were the appearance of 2 mm of ST segment deviation from baseline on the electrocardiogram, the occurrence of ventricular fibrillation, or 30 min of balloon inflation. During balloon inflation contrast injections were performed through the guiding catheter and flow distal to the balloon was graded 0-3 using the TIMI scale. The average (+/- SD) inflation time for the standard balloon was 3.1 +/- 2.2 minutes and for the perfusion balloon was 27.2 +/- 4.8 min (P less than 0.001). Electrocardiographic evidence of 2 mm of ST segment deviation from baseline was seen during 11/13 inflations with the standard balloon and in 3/11 balloon inflations with the perfusion balloon. Ventricular fibrillation occurred during 2/13 of the standard balloon inflations and in none during passive balloon inflations. Distal contrast flow during passive balloon inflations averaged 2.7 +/- 0.5 (TIMI scale 0-3) and was absent during inflations with the standard balloon. The perfusion balloon allowed prolonged inflations with excellent distal flow when compared to the standard balloon.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1990

Polymorphous low grade adenocarcinoma of minor salivary gland: a clinicopathologic and comparative immunohistochemical study.

Retrospective review of seven cases of polymorphous low grade adenocarcinoma (PLGA) revealed that the original histologic diagnosis in five instances was mixed tumor (four benign and one malignant). Comparison of PLGA tumors with eleven representative cases of benign pleomorphic adenoma of minor salivary gland (BPA) showed marked similarity in cytologic features. PLGA and BPA also exhibited similar mucohyaline and/or fibromyxoid stromal components. In contrast, tumor margins of the two neoplasms were quite different; margins of PLGA were consistently infiltrative, whereas those of BPA were generally well circumscribed and encapsulated. Immunophenotypic comparison confirmed the glial fibrillary acidic protein (GFAP) positivity in BPA reported by others, whereas cases of PLGA were uniformly nonreactive with this antibody. Although previous reports have emphasized the histologic similarities of PLGA and adenoid cystic carcinoma, our findings indicate that differentiation of PLGA from BPA may represent a more common diagnostic problem. Awareness of comparative histologic features is important in the differential diagnosis of these minor salivary gland neoplasms. Also, monoclonal GFAP may be useful in distinguishing cases of PLGA from BPA where histologic features are otherwise similar.

Adenocarcinoma↗
PubMed1989

Human papillomavirus genotype as a prognostic indicator in carcinoma of the uterine cervix.

The clinical implications of specific human papillomavirus (HPV) types in invasive cervical carcinomas are only beginning to be appreciated. In this series of 100 women with cervical cancers analyzed for the presence of HPVs 6, 11, 16, 18, and 31 by Southern blot hybridization, a more aggressive clinical behavior was demonstrated for tumors containing HPV 18 than for those with HPV 16 or those in which no HPV was identified. Among 69 stage Ib tumors, no significant differences were found in the size of tumor, presence of parametrial involvement, or lymph node metastasis among patients whose tumor contained HPV 16, HPV 18, or no HPV DNA; however, 45% of the women with HPV 18-containing tumors (five of 11) had recurrence, as compared with only 16% of those with HPV 16 (five of 31) during the 20-month mean follow-up period. This tendency for HPV 18-containing tumors to recur was seen with all histologic subtypes of cervical cancers and with all grades of tumor. In addition, patients with HPV 18-containing tumors were more likely to give a history of recent normal Papanicolaou smears than were those whose tumors contained HPV 16. Forty-four percent of women with HPV 18 in their tumors had a history of three class I Papanicolaou smears in the 3 years before the diagnosis of cancer, whereas a similar history was elicited in only 16% of those with HPV 16 in their tumors, suggesting that HPV 18-containing tumors might progress to invasion without a prolonged preinvasive period.

Carcinoma, Squamous Cell↗
PubMed1988

Adenocarcinoma of the cervix associated with human papillomavirus.

Eleven pure adenocarcinomas of the cervix were analyzed for human papillomavirus (HPV) types 6, 11, 16, 18 and 31 by Southern blot hybridizations. Seven tumors were positive for papillomavirus DNA. Five hybridized to the HPV 18 specific probe and two tumors hybridized to HPV 16. All tumors were negative for HPV 6/11 and 31, and no additional tumors became positive with hybridizations under nonstringent conditions to a mixture of HPV probes. No papillomavirus DNA was detected in 11 noncervical malignancies or in six hysterectomy specimens in which cancer was not present. The histopathologic and clinical features of the patients were correlated with the presence of HPV. The women with papillomavirus DNA in their adenocarcinomas tended to be younger (mean age, 37.3) than those that were negative for HPV (mean age, 49.0). The findings suggest that papillomaviruses may be an etiologic factor in the development of some adenocarcinomas of the cervix.

Adenocarcinoma↗
PubMed1988

Applications of a general method for deconvolution using compartmental analysis.

A method of deconvolution is illustrated using compartmental models. The approach can be used to determine an arbitrary unknown input function from a measured response and the impulse response of the system. Compartmental models are constructed to specify (a) the function fitting the response data and (b) the impulse response of the system. Simulation of these models is then used to construct the unknown input function.

Alanine↗
PubMed1988

Visual and clinical analysis of Bac-T-Screen urine screen results.

Of 337 urine specimens evaluated, 75 of the 113 that showed positive readings on the Bac-T-Screen urine-screening instrument were found by subsequent semiquantitative culture to yield either less than 10,000 CFU of mixed bacteria per ml or no growth (less than 100 CFU/ml by our criteria). We tried to determine what factors contributed to the positive Bac-T-Screen results by examining the 75 Bac-T-Screen-positive urine specimens with three visual methods: Gram staining, hemacytometer chamber counting, and filtering through a 5.0-microns-pore-size nitrocellulose filter with subsequent microscopic examination of the stained filter. Somatic cells and other particles present in those urine specimens that yielded positive readings by the Bac-T-Screen included epithelial cells in 43%, crystals and amorphous material in 33%, and leukocytes in 17% of the specimens. There was no relationship between the numbers of particles seen in urine and the magnitude of the relative absorbance reading obtained with the Bac-T-Screen. A retrospective chart review was conducted for patients with positive Bac-T-Screen results and negative cultures. Of the 75 patients, 6 were thought to have urinary tract infections on the basis of clinical criteria; the majority of the remaining 69 patients had clinical histories revealing systemic or urogenital conditions consistent with shedding of particles in the urine. A positive reading by the Bac-T-Screen system seemed to be related to the presence of somatic cells and other particles in urine; bacteriuria was not always detectable in these cases.

Bacteriuria↗
PubMed1988

Molecular abnormalities of bcr and c-abl in chronic myelogenous leukemia associated with a long chronic phase.

Median duration of the chronic phase of chronic myelogenous leukemia (CML) is 3 years; less than 20% of patients have a chronic phase greater than 7 years. It is unknown whether the length of chronic phase is stochastic or is predetermined for each patient. Since molecular abnormalities of bcr and c-abl occur in CML, we sought to determine whether there were differences in bcr and c-abl translocation or transcription in individuals with long v short chronic phase. These studies were performed in six patients with CML in whom chronic phase was 7+ to 26 years and 20 patients in whom chronic phase was less than 7 years. All patients had translocation of c-abl to within bcr. The distribution of breakpoints in bcr were similar in both groups. Transcription of the chimeric bcr/c-abl mRNA was comparable. These data suggest that changes in bcr or c-abl alone do not determine the duration of chronic phase in CML; other factors are likely involved.

Adult↗
PubMed1988

Plasminogen activator activity in vitamin A-deficient rat corneas.

Plasminogen activator (PA) activity during epithelial wound healing in vitamin A-deficient rats was investigated to determine whether a relationship exists between corneal defect formation and PA activity. Uniform, central 3 mm diameter corneal epithelial wounds were made by scalpel debridement in vitamin A-deficient and in pair-fed control rats. Cryostat sections of such corneas, taken at various times post-scrape, were overlaid with fibrin films containing plasminogen to examine the distribution of PA activity; and antibodies to tissue plasminogen activator (tPA) or to urokinase-like activator (uPA) were incorporated into the films so that the immunochemical natures of detected PA activities could be determined. Corneas from pair-fed controls showed tPA-dependent lysis in association with the regenerating epithelium as well as in the defect region during epithelial wound healing. Corneas from vitamin A-deficient rats also demonstrated tPA activity in association with corneal epithelium post-scrape but showed no detectable tPA activity in the defect region. Histological examination of the vitamin A-deficient corneas demonstrated that a pseudomembrane composed of PMNs, cell debris, and fibrinous exudate had formed on the scrape-debrided stromal surface. The migrating edge of regenerating epithelium overlaid this membrane and was, therefore, not in contact with the stromal surface. The formation of the pseudomembrane, which delays reepithelialization, might have resulted from the absence of PA activity in the defect region. Both excessive and inadequate levels of PA activity may result in impaired epithelial wound healing.

Animals↗
PubMed1987

Cloning and characterization of a novel T cell activation gene.

We have used the technique of subtractive hybridization to identify a T cell gene selectively expressed during activation via the antigen-receptor pathway. This gene, termed TCA3 (for T cell activation) encodes a mRNA which is expressed following concanavalin A (Con A) activation of T cell clones at levels of approximately 1% total poly(A)-containing mRNA. The cDNA isolate, termed TCA3.0, is 512 bases in length excluding poly(A) and encodes a predicted 92-amino acid protein having the characteristics of a secreted polypeptide of approximately 69 amino acids. The genomic organizations of TCA3 was determined for two lambda phage clones and was found to be a single copy gene containing at least three exons dispersed over less than 4.7 kb. The temporal appearance of TCA3 mRNA in response to several activating agents was examined. It is not transcribed in response to interleukin 2 stimulation, but is transcribed in response to either antigen or Con A stimulation and can be detected as early as 1 hr poststimulation. Expression TCA3 in response to Con A is blocked by cyclosporin A treatment. The combined data suggest that TCA3 may represent a new lymphokine.

Amino Acid Sequence↗
PubMed1987

Possible cytogenetic marker associated with myelofibrosis in chronic granulocytic leukemia and its prognostic significance.

An association between myelofibrosis (MF) and chronic granulocytic leukemia (CGL) has been recognized. MF is usually a sign of a poor prognosis but its relation to other important parameters of CGL is not known. We observed a 54-year-old, white male patient who was well until May 1983 when he began developing gradually increasing right hip and left shoulder pain. Clinical evaluation 3 months later revealed splenomegaly and a white blood count of 126,000 with 29 segmented neutrophils, 22 bands, 7 metamyelocytes, 11 myelocytes, 6 promyelocytes, 5 blasts, 2 eosinophils, 5 basophils, and 3 lymphocytes. Cytogenetic analysis by G-banding technique showed a male karyotype with all 20 bone marrow cells examined positive for the Philadelphia chromosome. The patient was placed on busulfan therapy with good symptomatic improvement, but later suffered severe thrombocytopenia. At the end of October 1983, he was admitted with blast crisis and thrombocytopenia and was initiated on vincristine and cytosine arabinoside therapy. His bone marrow was repeatedly inaspirable and the biopsy was characterized by diffuse fibrosis. Chromosome analysis of 16 spontaneously dividing cells in the blood at this time revealed that 86% of cells had a karyotype of 46,XY,t(9;22)(q34;q11),t(1;3)(p32;p21) with the rest of the cells having only the Ph chromosome. The patient died 4 months later of intracranial hemorrhage. Chromosome #3 involvement has been reported in acute MF and essential thrombocytosis, but no specific cytogenetic abnormalities have been found in MF associated with CGL. It is unclear whether t(1;3) in this case represents a cytogenetic marker of MF or blast transformation, but it is certainly associated with poor prognosis and short survival.

Blast Crisis↗