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Biomedical subjects

M Melamed

Publications and source records attributed to M Melamed.

At least 19 recordsLinked to original sources

Human monoclonal antibodies to C, c, E, e and G antigens of the Rh system.

A panel of heterohybridomas secreting human IgG and IgM monoclonal antibodies to the C, c, G, E, and e antigens of the Rh system has been established. Both classes of antibody have been shown to react with red blood cells carrying their respective antigens; those of the IgM class being able to directly agglutinate unmodified red blood cells in saline. The heterohybridomas have been shown to be suitable for bulk culture and produce levels of antibody in the range of 15-73 micrograms/ml in the spent culture supernatant.

Antibodies, Monoclonal

Flow cytometry as a predictive indicator in patients with operable gastric cancer.

Adenocarcinoma of the proximal portion of the stomach (gastroesophageal [GE] junction and cardia) is increasing in incidence. The inferior survival of patients with GE-cardia lesions as compared with patients with tumors located in the body and antrum has been attributed to anatomic features. To determine if a biological difference could explain the varying prognosis, flow cytometric studies were performed prospectively in 50 patients with operable gastric cancer and analyzed for association with site, histology, gender, age, stage, and disease-free survival. DNA aneuploidy significantly correlated with tumor location: 96% of GE-cardia carcinomas were aneuploid as compared with 48% of body-antrum tumors (P = .0008). Nodal involvement was more common in aneuploid tumors (P = .0548), and women were more likely to have diploid tumors than were men (P = .0233). The median disease-free survival for patients with diploid tumors was 18.5 months as compared with 5.4 months for patients with aneuploid carcinomas (P = .076). Furthermore, within the body-antrum of the stomach, patients with diploid tumors had a significantly better disease-free survival than did those with aneuploid tumors from the same site (18.4 v 4.7 months, P = .0185). These results indicate there is a difference in the DNA content of gastric tumors located in different sites within the stomach and that DNA content correlates with prognosis.

Adenocarcinoma

Influence of tumor cell DNA ploidy on the natural history of rectal cancer.

We have examined tumor cell DNA content as a possible variable in the behavior of early rectal cancer treated by local excision. Flow cytometry assays of tumor cell DNA content were carried out on specimens of archived, paraffin-embedded tissue specimens from 30 patients (11 male and 19 female) whose early rectal cancers were treated by curative local excision more than 60 months previously. The cancers invaded to the muscularis mucosae in 2 patients (1 with aneuploid disease and 1 with diploid disease), into the submucosa in 15 patients (7 with aneuploid disease and 8 with diploid disease), and the muscularis propria in 13 patients (8 with aneuploid disease and 5 with diploid disease). A total of 16 patients had aneuploid disease and 14 had diploid disease. Local recurrence of cancer developed in 12 patients. Of these 12 patients, 10 (83 percent) had aneuploid disease. By contrast, of the 18 patients who remained free of disease, 12 (67 percent) had diploid disease. Seven of the 12 patients with recurrence died. Six of these seven (86 percent) had aneuploid disease. The aggressive clinical behavior of the tumors with aneuploid DNA content was not otherwise predictable by standard histologic features. Aggressive tumor behavior appears to correlate closely with aneuploidy in locally treated rectal cancers, as opposed to a lack of correlation in our patients treated with major resection. The fact that these cancers are being treated by local excision may allow the prognostic impact of DNA content to reflect the natural history of cancer.

Adenocarcinoma

beta-Glucosidase in Candida albicans and its application in yeast identification.

In this report we attempt to explain the discrepancy between beta-glucosidase (EC 3.2.1.21) activity in Candida albicans as measured by commercial kits and that found in an experimental assay. beta-Glucosidase activity in American and Israeli isolates of C. albicans was evaluated with the API ZYM and YeastIdent systems (Analytab Products) and with experimental biochemical assays. Activity was found with whole cells and cell extracts of isolates from both sources. The greatest beta-glucosidase activity was found at pH 5.0 and with p-nitrophenyl-beta-glucopyranoside (PNP-BDG) as the substrate. In assays with beta-naphthyl-beta-D-glucopyranoside and 6-bromo-2-naphthyl-beta-D-glucopyranoside (6-Br-2-naphthyl-BDG), no enzyme activity was detected in whole cells and only limited activity was found in cell extracts of isolates from both sources. In studies with PNP-BDG at pH 5.0 and 7.5, 29 to 38% less activity was found at both pHs with American whole cells, and minor activity (20%) was found at pH 7.5 with isolates from both sources. Because assays with PNP-BDG in cell extracts of isolates from both sources showed no significant differences in activity, the more limited beta-glucosidase activity in American whole cells was most likely due to less efficient transport. Because the API ZYM system uses 6-Br-2-naphthyl-BDG as the substrate and because the substrate is buffered at pH 7.5 in the API YeastIdent kit, both systems appear to be of limited value for the detection of beta-glucosidase activity in C. albicans.

Candida albicans

Phase I/II trial of intravesical methotrexate for superficial bladder tumors.

Twenty-one patients with superficial transitional cell carcinoma of the bladder received a total of 121 doses of intravesical methotrexate (MTX) at 11 different concentrations of drug, ranging from 40 mg/m2 (mean concentration of 2.9 X 10(-3) M) to 500 mg/m2 (4.9 X 10(-2) M). Biochemical evidence of absorption was minimal in all cases. The maximum serum level was observed within 0.5-2 h in all patients and ranged from 1.8 X 10(-8) M to 5.0 X 10(-7) M. By 24 h the serum levels were negligible and ranged from 5.5 X 10(-9) M (the lowest limit detectable by the assay) to 4.4 X 10(-8) M in the patient who received the highest dosage of 500 mg/m2. Biologic evidence of absorption was minimal. Myelosuppression, mucositis, and nausea were not observed. Eighteen patients received six consecutive weekly doses ranging from 40 to 500 mg/m2. All patients had repeat cytoscopy performed within 2-4 weeks after six consecutive doses to evaluate local toxicity and efficacy. Flow cytometry was performed on the bladder washings of 22 patients, illustrating the use of flow cytometry, in conjunction with conventional cytology, as an additional means of objectively quantifying results. Despite MTX's established activity in systemic treatment of advanced bladder carcinoma, this study failed to demonstrate any clinical response to intravesically administered MTX, in doses of up to 500 mg/m2, and in concentrations of up to 4.9 X 10(-2) M.

Adult

Investigations of serum testosterone levels in patients with laryngeal cancers.

Serum testosterone levels were determined by a radioimmunological method in 102 patients with laryngeal carcinoma and in a control group of 10 healthy men. All patients were examined before the initiation of any operative or radiation therapy and after termination of treatment. The testosterone levels in the cancer patients showed a tendency toward higher values when compared with a control group of healthy men. These results indicate that hormone preparations could be considered as part of the therapy of laryngeal carcinomas.

Adult

Immunohistologic dissection of the human kidney using monoclonal antibodies.

Nine murine monoclonal antibodies which detect differentiation antigens of the human kidney are described. Immunofluorescence and immunoperoxidase studies demonstrate that these antigens are expressed by different cell types comprising the nephron. Monoclonal antibody MA99 detects a glycoprotein complex of the glomerular basement membrane. Monoclonal antibody S4 detects a glycoprotein of 160,000 daltons (gp160) expressed by glomerular and proximal tubular epithelial cells. Monoclonal antibodies S23, S27 and S6 immunoprecipitate a glycoprotein of 120,000 daltons (gp120) found on cells of the proximal tubule and portions of Henle's loop. Monoclonal antibody C26 identifies a glycoprotein of 40,000 daltons (gp40) expressed by cells of the distal and collecting tubules. Monoclonal antibodies M2 and S8 are specific for A and B blood group antigens, respectively, found on cells of the collecting tubule in individuals of the respective blood type. This panel of antibodies is useful in the study of normal renal embryogenesis, microanatomy and physiology as well as pathological processes including tumors.

Animals

Malignant cells in cerebrospinal fluid (CSF): the meaning of a positive CSF cytology.

We reviewed the correlation between malignant cells in cerebrospinal fluid (CSF) (positive cytology) and pathologic findings at autopsy. The purpose was to discover: (1) the incidence of negative CSF cytology in patients with CNS malignancy, (2) the incidence of false-positive cytology, and (3) the relationship between a true-positive cytology and the distribution of malignant tumor at autopsy. Of 117 patients with CNS tumor and premortem cytologic examination of the CSF, 31 (26 percent) were positive and 86 (74 percent) were negative. Only 1 of 66 patients with tumor that did not reach the leptomeninges had a positive cytology. Of 51 patients with leptomeningeal tumor at autopsy, cytology was positive in 30 (59 percent) and negative in 21 (41 percent). Five potentially "false-positive" cytologies were encountered: three patients were treated, and tumor may have been eradicated; in two patients with lymphoma, inflammatory cells associated with infection were apparently mistaken for malignant cells. These data indicate that a positive CSF cytology is a reliable indicator of CNS malignancy and almost always reflects leptomeningeal tumor.

Brain Neoplasms

Preliminary report of the lung cancer detection program in New York.

The early lung cancer detection program in New York is described, and preliminary prevalence rate data are reported. Cigarette-smoking men over the age of 45, who are considered at high risk, are encouraged to enroll in the program and, to date, 6,612 have done so. These men receive PA and lateral chest x-rays annually, while a randomly selected sub-population of about half also have sputum cytology every four months. A controlled study of sputum cytology as an adjunct to the chest x-ray is now in progress. There were 15 cases of late lung cancer (pathologic stages II and III) detected at the initial examination, and 11 early cases (pathologic stages O and I). In the population of 3,387 men who had x-rays alone there were three early lung cancers detected; in the population of 3,225 men who had both examinations four early cancers were detected by x-ray and four by cytology. In addition, three cases of larynx cancer were detected by cytology. The early lung cancers detected by x-ray were peripheral and most were bronchiolar or adenocarcinoma; the early cancers detected by cytology were central epidermoid carcinoma of major bronchi. No early carcinomas were detected by both techniques. These findings suggest that a combination of chest x-rays and sputum cytology can be more effective than either one alone in detecting early lung cancer.

Age Factors

[Morphologic study of teflon implanted in the prelaryngeal space of dogs].

The authors described their experimental studies on dogs, using aliomaterial teflon- in forming FTM slap in the prelaryngieal space for the purposes of the reconstructing plastica of the larynx. The teflon was a suitable material because of its good tolerance and well occuring reactions of the pathologic organization, combined with the processes of resorption and its substitution with connective tissue. The authors found the period of 10 to 20 days as the earliest and most suitable period for the usage of FTM slap.

Animals

Simulated paraspinal tumor or abscess by rounded atelectasis of the lower lobe.

Lower lobe atelectasis may simulate paraspinal tumor or abscess when margins of the completely collapsed lobe become rounded laterally and the inferior edge separates from the diaphragm. We believe this unusual appearance relates to (1) influence of the pulmonary ligament and (2) total collapse of the lobe to its minimum possible volume. Three cases of different etiologies are herein presented.

Adenoma

Endoscopic diagnosis of advanced gastric cancer. Factors influencing yield.

Factors influencing diagnostic yield by directed endoscopic biopsy and cytology were studied in 50 patients with advanced gastric cancer using a forward-viewing panendoscope. The diagnostic yield was higher for exophytic lesions than for infiltrative tumor, and directed brush cytology alone was more productive than directed biopsy alone. The lesions that provided non-diagnostic tissue were mostly recurrent or infiltrative cancers, and were most often in the cardia, antrum, or were of the linitis plastica type. The combination of infiltrative character and location in antrum or cardia, especially if recurrent, often resulted in non-diagnostic biopsy and cytology specimens.

Biopsy