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Biomedical subjects

M Inbar

Publications and source records attributed to M Inbar.

At least 55 records · Page 3Linked to original sources
PubMed1986

Monoclonal antibodies embedded in their hybridoma cells: an immunodiagnostic concept.

Aldehyde fixation of hybridoma cells during active production of monoclonal antibodies (MAbs) resulted in the formation of an insoluble phase because a large number of immunologically active antibody molecules were immobilized on the fixed hybridoma cells. Such MAb preparations specific to large protein molecules and small haptens were used for the development of a homogeneous immunoassay concept.

Antibodies, Monoclonal↗
PubMed1985

Acral (volar-subungual) melanoma.

Acral melanoma occurs in the volar surface of the hands, feet, fingers, toes and subungual sites. Recently it has been recognized as a distinct entity with characteristic clinical and pathological features. Of our 340 patients with malignant melanoma, 24 (7 per cent) had acral melanoma. Sixteen were in the plantar skin, two in the palms and six in the nailbed. The delay in diagnosis was 6 months to 5 years and most of the patients presented with large neglected tumours. Fourteen lesions had histological features consistent with acral lentiginous melanoma - a unique pattern to this area. Fourteen patients were in clinical stage I at diagnosis, seven in stage II and three had distant metastases (stage III). The treatment was mainly surgical. Palmar-plantar lesions were widely excised. One patient underwent below-knee amputation. Lesions of the digits were treated by amputation of the affected toe. Fourteen of the patients underwent either prophylactic or therapeutic lymph node dissection. In 9 of them, regional metastases were found. In patients with advanced disease chemotherapy was added. Three patients had isolated limb perfusion. Fourteen patients died of metastatic disease within 1-5 years. Four are alive but have metastatic spread. Six patients are disease-free, one to 4.5 years following diagnosis.

Adult↗
PubMed1985

Endometrial carcinoma stage I--comparison of two different treatment regimes--evaluation of risk factors and its influence on prognosis; suggested step by step treatment protocol.

Two hundred twenty-four patients with stage I endometrial carcinoma were treated between the years 1964 and 1978. One hundred and fifteen patients were classified as clinical stage Ia (51.3%) and 109 patients as clinical state Ib (48.7%). For stage Ia the standard treatment protocol was total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH + BSO). In stage Ib disease, preoperative irradiation was performed followed by TAH + BSO after an interval of 4 to 6 weeks. Postoperative irradiation to the pelvis and vaginal vault was given when extrauterine spread was found and in cases of myometrial penetration beyond the inner one-third of the myometrium. At evaluation in May 1983, the rate of disease recurrence in stage Ia was 20% and in stage Ib 9.1%. Five-year survival in stage Ia was 77.3% and 72.4% in stage Ib. Preoperative irradiation was found justified for G3 disregarding the clinical stage, therefore the approach of routine preoperative irradiation in stage Ib is not recommended. The uterine cavity depth was found to be an inaccurate prognostic parameter. According to the data collected in our material the histological grade and myometrial invasion are much better prognostic parameter and should be taken into consideration while planning the treatment regime.

Adenocarcinoma↗
PubMed1985

Population differences in ovarian cancer in Israel.

One hundred and seven patients with epithelial carcinoma of the ovaries were studied in an Israeli population in the Tel Aviv area. The women under study belonged mainly to two ethnic groups: European and North American (Ashkenazi) and Afro-Asian immigrants. The highest incidence of this neoplasm was found in the Ashkenazi group and the lowest in the Afro-Asian (less than 50%). It has been found that there is an age variation in the onset of the disease between the two ethnic groups. The average age of all the patients was 57 years, but in the Afro-Asian group of patients, the malignancy was more commonly found in the 45-54 age group (P less than 0.05). A tendency of a shorter survival rate due to more aggressive disease in the Afro-Asian group was observed. Survival rate for patients with FIGO stages I and II was lower in the Afro-Asian group. These conclusions were supported by the statistical significance of the data.

Adenocarcinoma↗
PubMed1984

Monoclonal antibody specific to the beta subunit of human chorionic gonadotropin (hCG) and capable of agglutinating hCG-coated red blood cells.

Spleen cells of BALB/c mice immunized with human chorionic gonadotropin (hCG) were fused with NS-1 mouse myeloma cells. A hybrid cell line, clone PE4 secreting monoclonal antibody (MAb) to hCG was isolated by simultaneous screening with both a radioimmunoassay (RIA) and a hemagglutination inhibition assay (HAI). With the aid of the double-antibody radioimmunoassay, it was established that PE4-MAb recognizes the beta-subunit of hCG. It shows an affinity constant of 0.4 X 10(10) L/M and cross-reactivity of 0.1% to other related human glycopeptide hormones. PE4-MAb agglutinates sheep red blood cells coated with hCG and can be used in an HAI assay for hCG. Dual screening procedures have, thus, led to a monoclonal antibody showing high sensitivity in two different assays, and hence useful for the qualitative detection and quantitative determination of hCG by both RIA and HAI methods.

Animals↗
PubMed1983

Breast carcinoma originating in cystosarcoma phyllodes.

Only three cases of carcinoma infiltrating the stroma of cystosarcoma phyllodes have been reported. An additional case is presented. Unlike the treatment of cystosarcoma phyllodes which is limited to complete removal of the tumor, carcinosarcomas should be treated in the same manner as carcinoma by mastectomy and axillary dissection.

Adenocarcinoma↗
PubMed1982

Monoclonal antibodies against immunodeterminants associated with the alpha and beta subunits of human chorionic gonadotropin.

Spleen cells of BALB/c mice immunized with human chorionic gonadotropin (HCG), a glycopeptide hormone composed of two nonidentical alpha and beta subunits, were fused with NS-1 mouse myeloma cells. Two hybrid cell lines, cone PC2 and clone PD3 secreting monoclonal antibodies (McAb) to HCG were isolated. With the aid of a double antibody radioimmunoassay it was established that PC2-McAb recognizes an immunodeterminant associated with beta-HCG subunit, whereas, PD3-McAb recognizes an epitope present on the alpha-HCG subunit. Both monoclonal antibodies showed an affinity constant of approximately 5 X 10(10) L/M. Because of these immunological characteristics, only PC2-McAb specifically reacts with HCG and shows cross-reactivities of less than 0.1% to other related human glycopeptide hormones. On the other hand, using a hemagglutination test based on antibody induced agglutination of sheep red blood cells coated with HCG, it was shown that only PD3-McAb is capable of inducing a positive reaction, although both monoclonal antibodies have a similar binding capacity to the coated cells. The potential of these two new monoclonal reagents for the qualitative detection and quantitative determination of HCG in human biological fluids is discussed.

Animals↗
PubMed1979

Dynamics and composition of serum lipids in hyperlipoproteinemias.

The microviscosity of serum lipids in patients with hyperlipoproteinemia and normal donors was determined by monitoring the degree of fluorescence polarization of the fluorescent probe 1,6-diphenyl-1,3,5-hexatrine (DPH). Determination of serum lipids--serum total cholesterol, serum triglycerides, and serum phospholipids--revealed that an increase in the ratio of cholesterol/triglyceride + phospholipid is accompanied by an increase in the degree of fluorescence polarization and an increase in the microviscosity values. Similar results were obtained with sonicated liposomes prepared from serum lipids extracts. This correlation between dynamics and composition of serum lipids was further supported by results obtained with an artificial model system of sonicated lipids dispersions. The results have shown that high microviscosity values are characteristic in patients with high levels of serum cholesterol, and that low microviscosity values are characteristic in patients with high levels of serum triglycerides. It is suggested therefore that this technique may serve as a basis for a rapid screening test for hyperlipoproteinemias.

Adult↗
PubMed1979

Fluorescence polarization of DPH-labeled cells adsorbing viruses and its diagnostic potential.

Mammalian or avian cells were labeled with a fluorescent probe DPH (1,6-diphenyl-1,3,5-hexatriene). Within a few minutes after adsorption of various naked and enveloped viruses, the degree of fluorescence polarization (P) of the DPH embedded in the adsorbing cells as measured at 37 degrees C, was reduced, a finding indicating a decrease in the microviscosity of the lipids in the cell membrane. This change of fluidity was proportional to the concentration of the adsorbing virus and could be abolished or inhibited by homologous specific antiviral sera, but not by heterologous sera. Potential use of fluorescence polarization tests is described for titration of virus concentration, as well as for serological identification of a virus.

Adsorption↗
PubMed1978

Translocation of a hydrocarbon fluorescent probe between Epstein-Barr virus and lymphoid cells: an assay for early events in viral infection.

Translocation of the hydrocarbon fluorescent probe diphenylhexatriene (DPH) between membranes was studied by fluorescence polarization (P) analysis. First, using a model system, the high P value (0.324) of DPH-labeled cholesterol/phosphatidylcholine liposomes and the low P value (0.157) of DPH-labeled phosphatidylcholine liposomes allowed detection of DPH translocation between interacting liposomes. This was monitored by the change in P in either direction. Early events during cell-virus interactions were similarly studied by monitoring DPH translocation. The P value of DPH-labeled Epstein-Barr Virus (EBV) was significantly higher (0.350-0.392) than the P value of DPH-labeled lymphoid cells (0.238-0.289). Hence, DPH translocation could be detected by changes in P following incubation of DPH-labeled EBV and nonlabeled cells. A marked decrease in P was observed after incubation of DPH-labeled EBV with either nonlabeled lymphoblastoid Raji cells or fresh human B lymphocytes. However, only a slight decrease in P was obtained when DPH-labeled EBV was incubated with either nonlabeled fresh human T lymphocytes or fresh T or B rabbit lymphocytes. Moreover, incubation of fresh human B lymphocytes with the purified C3 component of complement (a putative inhibitor for the EBV receptor) prior to the addition of DPH-labeled EBV abolished the observed decrease in the P value. Most of these experiments were carried out with both the P3HR-1 and the B95-8 strains of EBV. DPH translocation, as determined by fluorescence polarization analysis, is, therefore, measuring some early event during interaction of this enveloped virus and mammalian cells. The potential applicability of this technique to other viruses is illustrated by an experiment with Semliki Forest virus.

Cells, Cultured↗
PubMed1978

Decreased microviscosity of membrane lipids in leukemic cells: two possible mechanisms.

Steady-state fluorescence polarization studies with the fluorescent lipid probe 1,6-diphenyl 1,3,5-hexatriene were done to determine the degree of microviscosity of cellular membrane lipids and serum lipoproteins in human normal donors and leukemic patients. The results show a marked decrease in microviscosity of cellular membrane lipids in both intact lymphocytes and isolated cellular plasma membranes obtained from leukemic patients in clinical relapse as compared to intact lymphocytes and isolated cellular plasma membranes obtained from normal donors and leukemic patients in complete clinical remission. Concomitant to these dynamic changes in cellular membrane lipids, the degree of microviscosity of lipids in the blood serum of leukemic patients in clinical relapse is markedly reduced as compared to serum obtained from normal donors and leukemic patients in complete clinical remission. Moreover, an in vitro incubation of leukemic lymphocytes with normal low density lipoproteins results in an increased microviscosity of cellular membrane lipids. In addition to the interrelation between cellular membrane lipids and serum lipoproteins, plasma membrane vesicles with a high degree of lipid microviscosity were isolated from the blood serum and pleural effusion of leukemic patients in clinical relapse. Such membrane vesicles could not be detected in normal serum. Therefore, we suggest that the two major mechanisms associated with the decreased microviscosity of membrane lipids in human leukemic cells are an abnormal exchange in lipids between the leukemic cell surface membrane and leukemic serum lipoproteins and an exfoliation of plasma membrane vesicles with a high degree of microviscosity from the cell surface of leukemic cells.

Cell Membrane↗
PubMed1978

Dynamic parameters of membrane lipids in normal and leukemic human lymphocytes isolated from peripheral blood and bone marrow.

The degree of microviscosity (eta), and lipid fluidity (LFU) of cellular membranes of normal and leukemic lymphocytes obtained from peripheral blood and bone marrow of normal donors and acute lymphatic leukemic (ALL) patients was quantitatively monitored by fluorescence polarization analysis with the aid of the fluorescent lipophilic probe 1,6-diphenyl-1,3,5-hexatriene when embedded in cellular membranes of intact cells. The results have shown a marked decrease in eta and a significant increase in LFU in lymphocytes obtained from both peripheral blood and bone marrow of ALL patients at admission when compared to both T- and B-lymphocytes obtained from peripheral blood of normal donors. Moreover, both dynamic parameters, eta and LFU, show normal characteristic values in lymphocytes obtained from bone marrow of ALL patients in complete hematological remission. Since in few cases a decrease in eta and an increase in LFU were observed in bone marrow lymphocytes isolated from ALL patients in remission, the possibility that these dynamic parameters may serve as a diagnostic tool for an early detection of a new relapse is discussed.

B-Lymphocytes↗
PubMed1978

Decrease in 5'-nucleotidase activity in malignant transformed and normal stimulated cells.

Analysis of six different cell types of normal and transformed fibroblasts grown in vitro and of four different cell types of normal and leukemic lymphocytes grown in vivo have shown a marked decrease of 3- to 30-fold in the specific activity of 5'-nucleotidase in the malignant cells as compared to their normal parental cells. The results have also indicated that a serum stimulation of untransformed or normal fibroblasts and a stimulation of normal lymphocytes by concanavalin A resulted in a significant decrease in the specific activity of 5'-nucleotidase of the stimulated cultures as compared to the resting cells. In both the malignant cells and the stimulated normal cells, the decrease in 5'-nucleotidase activity was not accompanied by a similar decrease in the specific activity of acid phosphatase, indicating a specific enzyme alteration in the surface membranes of the transformed and the normal stimulated cells.

Animals↗