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Biomedical subjects

D Fishman

Publications and source records attributed to D Fishman.

At least 19 recordsLinked to original sources
PubMed2006

The flow-cytometry-based evaluation of cellular immunity in cases of cutaneous leishmaniasis and healthy controls from the endemic area in southern Israel.

Only limited data are available on the early immunological events associated with human cutaneous leishmaniasis (CL). In this study, peripheral-blood mononuclear cells were obtained from 66 individuals (34 patients with cutaneous lesions and 32 apparently healthy controls) who had each spent no more than 3 months in the endemic region of Qetzioth, in southern Israel. These cells' responses to Leishmania major antigen were then explored, by the flow-cytometry-based evaluation of blast transformation (BT). The lymphocytes from 17 (50%) of the patients but only one (3%) of the controls displayed BT. When, in an ELISA, most (52) of the subjects were checked for anti-L. major antibodies, none of the 22 controls investigated but 19 (63%) of the 30 patients were found seropositive. Although 14 (47%) of the 30 patients who were checked for antibodies were BT-positive, the seropositive patients were not significantly more or less likely to be BT-positive than the seronegative patients (P<0.919). These data indicate that, in CL, the hosts' cellular and humoral responses develop independently within the first 3 months post-infection, but further investigation is required to confirm this hypothesis.

Animals↗
PubMed2005

[Prehospital medical care organization during the 2003 G8 summit: a new concept of Mobile Medical Squadrons (MMS)].

OBJECTIVE: The occurrence of the 2003 G8 summit in Evian and the threat of major civil riots or even terrorist attacks in the Swiss neighbourhood forced us to imagine a new system of rescue and medical care in case of numerous victims. Previous occurrences of the G8 in Europe or America have demonstrated the need of flexible and mobile structures, able to respond quickly to crowd movements, unlike the usual static structure of rescue systems designed for major accidents. METHODS: We developed a new concept of Mobile Medical Squadrons (MMS) consisting of several vehicles and medical care and rescue human resources. In our concept, each MMS consisted of 3 emergency doctors, 5 paramedics and 9 first-aid workers. They were designed to handle 15 patients, with a large autonomy in terms of rescue, medical care, evacuation and medical authority. The equipment included medical, resuscitation, simple decontamination, evacuation and communication materials. RESULTS: The MMS were dispatched four times during the G8 summit following civil riots. They took care of 12 injured patients. CONCLUSION: The concept of MMS as a reinforcement of the existing rescue and health care resources appears as a new flexible, a modular and useful concept for the medical management of collective prehospital emergency situations. Its use is suggested instead of the traditional static concept of rescue systems designed for major accidents.

Allied Health Personnel↗
PubMed2004

The integrity of cholesterol-enriched microdomains is essential for the constitutive high activity of protein kinase B in tumour cells.

A deregulated activity of PKB/Akt (where PKB stands for protein kinase B) renders tumour cells resistant to a variety of apoptosis-inducing stimuli. Elucidation of the mechanisms responsible for this deregulation is of prime importance for the development of novel anti-cancer drugs. Results of the present study demonstrate that the constitutive activity of PKB/Akt in B16BL6 melanoma cells depends on the integrity of cholesterol-enriched membrane microdomains, since the exposure of cells to cholesterol-depleting agents decreases the phosphorylation of this enzyme, with no change in its total protein level. Inhibitors of Hsp90 (heat-shock protein 90) decreased phosphorylation of PKB/Akt with a similar pattern. Dephosphorylation of the enzyme, as a consequence of raft disintegration, could be precluded by inhibition of serine/threonine (but not tyrosine) phosphatases. Our results imply that destabilization of lipid rafts seemingly affects the association of Hsp90 with the respective serine/threonine phosphatases, thereby increasing the accessibility to PKB/Akt to deactivating phosphatases. We have found recently that reconstituted expression of H-2K class I glycoproteins in class I-deficient B16BL6 cells also decreases the phosphorylation of PKB/Akt. Therefore it is possible that raft-associated regulation of this important enzyme involves both H-2K glycoproteins and Hsp90.

Animals↗
PubMed2004

Low electric field enhanced chemotherapy can cure mice with CT-26 colon carcinoma and induce anti-tumour immunity.

Low electric field cancer treatment-enhanced chemotherapy (LEFCT-EC) is a new anticancer treatment which utilizes a combination of chemotherapeutic agents and a low electric field. We investigated the antitumour effectiveness of this technique in a model of murine colon carcinoma (CT-26). The low electric field was applied to approximately 65 mm3 intracutaneous tumours after intratumoral injection of 5FU, bleomycin or BCNU. We observed significant tumour size reduction and a prolongation of survival time. The complete cure of a significant fraction of animals treated by LEFCT-EC with 5FU (33%), bleomycin (51%) or BCNU (83%) was observed. Mice cured by LEFCT-EC developed resistance to a tumour challenge and their splenocytes had antitumour activity in vivo. Our results suggest that LEFCT-EC is an effective method for treatment of solid tumours.

Animals↗
PubMed2004

Non-immune functions of MHC class I glycoproteins in normal and malignant cells.

MHC class I glycoproteins play a pivotal role in the regulation of immune responses by presenting antigenic peptides to cytotoxic T lymphocytes and by regulating cytolytic activities of natural killer cells. Cells originating in malignant tumours are often characterized by a profound immune escape phenotype. This phenotype is frequently associated with alterations in MHC class I-related antigen processing and presentation that enable tumours to escape immune surveillance. However, it now becomes clear that MHC class I molecules do not only provide a mechanistic framework for the presentation of antigenic peptides but, rather, possess broader biological functions due to their ability to regulate cell-to-cell communication and receptor-mediated trans-membrane signal transduction. In the present review we made an attempt to reevaluate the significance of an altered MHC class I phenotype for tumour progression in view of the current state of knowledge concerning the aforementioned non-immune functions performed by these membrane glycoproteins.

Animals↗
PubMed2001

Tubal ligation and risk of ovarian cancer in carriers of BRCA1 or BRCA2 mutations: a case-control study.

BACKGROUND: In several case-control and prospective studies, tubal ligation has been associated with a decreased risk of invasive epithelial ovarian cancer. We aimed to assess the potential of tubal ligation in reducing the risk of ovarian cancer in women who carry predisposing mutations in the BRCA1 or BRCA2 genes. METHODS: We did a matched case-control study among women from Canada, the USA, and the UK who had undergone genetic testing and who carried a pathogenic mutation in BRCA1 or BRCA2. Cases were 232 women with a history of invasive ovarian cancer, and controls were 232 women without ovarian cancer, and who had both ovaries intact. Cases and controls were matched for year of birth, country of residence, and mutation (BRCA1 or BRCA2). The odds ratio for developing ovarian cancer was estimated for tubal ligation, adjusting for oral contraceptive use, parity, history of breast cancer, and ethnic group. FINDINGS: In an unadjusted analysis among BRCA1 carriers, significantly fewer cases than controls had ever had tubal ligation (30 of 173 [18%] vs 60 of 173 [35%], odds ratio 0.37 [95% CI 0.21-0.63]; p=0.0003). After adjustment for oral contraceptive use, parity, history of breast cancer and ethnic group, the odds ratio was 0.39 (p=0.002). Combination of tubal ligation and past use of an oral contraceptive was associated with an odds ratio of 0.28 (0.15-0.52). No protective effect of tubal ligation was seen among carriers of the BRCA2 mutation. INTERPRETATION: Tubal ligation is a feasible option to reduce the risk of ovarian cancer in women with BRCA1 mutations who have completed childbearing.

Adult↗
PubMed2001

The role of MHC class I glycoproteins in the regulation of induction of cell death in immunocytes by malignant melanoma cells.

A deranged expression of MHC class I glycoproteins, characteristic of a variety of malignancies, contributes to the ability of cancer to avoid destruction by T cell-mediated immunity. An abrogation of the metastatic capacity of B16 melanoma cells has been achieved by transfecting an MHC class I-encoding vector into class I-deficient B16 melanoma clones [Gorelik, E., Kim, M., Duty, L. & Galili, U. (1993) Clin. Exp. Metastasis 11, 439-452]. We report here that the deranged expression of class I molecules by B16 melanoma cells is more than a mere acquisition of the capacity to escape immune recognition. Namely, cells of the B16 melanoma prompted splenic lymphocytes to commit death after coculture. However, a class I-expressing and nonmetastatic CL8-2 clone was found to be less potent as an inducer of apoptosis than class I-deficient and metastatic BL9 and BL12 clones. Both Thy1.2(+) and Thy1.2(-) splenocytes underwent cell death when exposed to the class I-deficient BL9 clone. A proportion of CD4(+) and CD8(+) cells among splenocytes exposed to the BL9 clone was lower than that observed in a coculture with cells of the CL8-2 clone. Consistently, none of the melanoma clones studied produced a ligand to the FAS receptor (FAS-L). Thus, our results provide evidence that (i) the production of FAS-L may not be the sole mechanism by which malignant cells induce apoptosis in immunocytes, and (ii) absence of MHC class I glycoproteins plays an important role in preventing the elimination of potential effector immunocytes by tumor cells.

Alleles↗
PubMed2001

Prevalence and correlates of mitral regurgitation in a population-based sample (the Strong Heart Study).

Evidence suggesting that mitral regurgitation (MR) may be induced by appetite suppressant medications heightens the importance of understanding the prevalence and correlates of MR, especially its relation to obesity, in population-based samples. MR was assessed by color Doppler echocardiography in 3,486 American Indian participants in the Strong Heart Study. Mild (1+) MR was present in 19.2%, moderate (2+) MR in 1.6%, moderately severe (3+) in 0.3%, and severe (4+) in 0.2% of participants. In univariate analyses, MR was unrelated to gender, diabetes, or lipid levels, but was more frequent in North/South Dakota (28.3%) than in Oklahoma (21.6%) or Arizona (14.3%) (p <0.001). MR was related to lower body mass index (BMI) (p <0.001), older age (p <0.001), higher systolic blood pressure (p = 0.003), higher serum creatinine (p <0.001), and higher urine albumin/creatinine ratio (p <0.001). In multivariate analyses, the presence and severity of MR were independently associated with higher serum creatinine, lower BMI, mitral stenosis, prior myocardial infarction, female gender, mitral valve prolapse and, variably, older age. In conclusion, MR, mostly mild, is detected by color Doppler echocardiography in >20% of middle-aged and older adults. MR is independently associated with female gender, lower BMI, older age, and renal dysfunction, as well as with prior myocardial infarction, mitral stenosis, and mitral valve prolapse. It is not related to dyslipidemia or diabetes.

Aged↗
PubMed2001

The I1-imidazoline receptor in PC12 pheochromocytoma cells activates protein kinases C, extracellular signal-regulated kinase (ERK) and c-jun N-terminal kinase (JNK).

We sought to further elucidate signal transduction pathways for the I1-imidazoline receptor in PC12 cells by testing involvement of protein kinase C (PKC) isoforms (betaII, epsilon, zeta), and the mitogen-activated protein kinases (MAPK) ERK and JNK. Stimulation of I1-imidazoline receptor with moxonidine increased enzymatic activity of the classical betaII isoform in membranes by about 75% and redistributed the atypical isoform into membranes (40% increase in membrane-bound activity), but the novel isoform of PKC was unaffected. Moxonidine and clonidine also increased by greater than two-fold the proportion of ERK-1 and ERK-2 in the phosphorylated active form. In addition, JNK enzymatic activity was increased by exposure to moxonidine. Activation of ERK and JNK followed similar time courses with peaks at 90 min. The action of moxonidine on ERK activation was blocked by the I1-receptor antagonist efaroxan and by D609, an inhibitor of phosphatidylcholine-selective phospholipase C (PC-PLC), previously implicated as the initial event in I1-receptor signaling. Inhibition or depletion of PKC blocked activation of ERK by moxonidine. Two-day treatment of PC12 cells with the I1/alpha2-agonist clonidine increased cell number by up to 50% in a dose related manner. These data suggest that ERK and JNK, along with PKC, are signaling components of the I1-receptor pathway, and that this receptor may play a role in cell growth.

Adrenergic alpha-Agonists↗
PubMed2001

Left ventricular systolic dysfunction in a biracial sample of hypertensive adults: The Hypertension Genetic Epidemiology Network (HyperGEN) Study.

To determine the prevalence and correlates of left ventricular systolic dysfunction in hypertensive patients in a biracial population-based sample, clinical evaluation and echocardiography were performed in 2086 participants in the Hypertension Genetic Epidemiology Network (HyperGEN) examination; 86% had normal ejection fraction (>54%), 10% had mild ventricular dysfunction (ejection fraction 41% to 54%), and 4% had severe ventricular dysfunction (ejection fraction </=40%). Prevalences of mild and severe ventricular dysfunction were higher in men than women (14% versus 8% and 7% versus 3%, P<0.001) and, weakly, in diabetics than nondiabetics (13% versus 10% and 6% versus 4%, P=0.07). Patients with severe ventricular dysfunction were older than those with mild dysfunction or normal function (mean, 58 versus 54 and 54 years, respectively; P=0.005) and had higher mean creatinine (1.20 versus 1.05 and 1.00 mg/dL) and uric acid (6.9 versus 6.3 and 6.1 mg/dL) levels (both P<0.001). Those with severe ventricular dysfunction, compared with those with mild dysfunction or normal ejection fraction, had greater mean ventricular internal dimension (6.2 versus 5.6 and 5.1 cm) and mass (61 versus 50 and 43 g/m(2.7)) and lower relative wall thickness (0.31 versus 33 and 0.35; all P<0.0001). Severe and mild ventricular dysfunction was associated with lower myocardial contractility (mean stress-corrected midwall shortening, 68% versus 94% versus 106% of predicted; P<0.0001). In regression analyses, lower ejection fraction as a continuous variable was independently and positively associated with male gender, diabetes, uric acid level, and body mass index. With the addition of echocardiographic variables, lower ejection fraction was associated with male gender, black race, prior myocardial infarction, and higher ventricular mass and lower relative wall thickness, pulse pressure, and body mass index. In a population-based sample of hypertensive patients, left ventricular systolic dysfunction was related to male gender, black race, diabetes, and elevated uric acid levels, as well as higher ventricular mass and lower relative wall thickness.

Adult↗
PubMed2001

[Thoracic pain].

Explore the source record for details and available documents.

Acute Disease↗
PubMed2001

"Natural histories" of mitral valve prolapse. Influence of patient selection on cardiovascular event rates.

BACKGROUND: In previous studies the reported incidence of cardiovascular events among mitral valve prolapse patients has differed more than 10 fold. We endeavored to determine the relation between the clinical features and mode of ascertainment of mitral valve prolapse and the resulting event rate. METHODS: Between January 1979 and August 1996, 275 patients (129-47% men, 146-53% women, mean age 43 +/- 19 years), were followed for a mean of 98 months after evaluation in a referral center for valvular heart disease. Comparative data were obtained from a separate, less selected population consisting of 316 patients. RESULTS: A total of 65 events occurred (2.9/100 patient-years): 46 (2.0/100 patient-years) mitral surgery, 12 cardiac deaths (0.5/100 patient-years), 6 neurologic ischemia (0.26/100 patient-years), and 1 infective endocarditis (0.04/100 patient-years). The overall event rate varied significantly according to demographic, clinical and echocardiographic variables (all p < 0.0001). It was higher among males (odds ratio-OR 2.1), subjects > or = 45 years of age (OR 14.7), those with a holosystolic murmur (OR 25.9), an enlarged left ventricle (OR 13.5) or left atrium (OR 34.9) and those with 3-4+ mitral regurgitation at color Doppler echocardiography (OR 40.0). It was lower in those with an audible mid-systolic click (OR 0.05). These ORs closely resembled those we reported previously in a less selected population. At multivariate analysis, male gender (p = 0.013), severe Doppler mitral regurgitation (p = 0.0048), and left atrial enlargement (p = 0.046) were all independent predictors of events. CONCLUSIONS: In a population of mitral valve prolapse patients, including many with significant mitral regurgitation at baseline, we identified similar predictors of events but an overall event rate nearly 3 times higher than that we previously reported for relatively unselected patients or family members in New York City (1/100 patient-years). Therefore, the impact of patient selection on the prevalence of mitral regurgitation, older age and male gender strongly affects the adversity of the "natural history" of mitral valve prolapse.

Adolescent↗
PubMed2001

[Advanced Trauma Life Support: towards a standardization of care for the trauma patient].

The ATLS concept is a strategy for the treatment of the injured patient and a teaching method. ATLS originates from the USA and it was introduced in the French speaking part of Switzerland two years ago. This article describes the principles that made ATLS successful, as well as its objectives and impact on the treatment of injured patients. As a consequence, a trend is now emerging towards a standardisation of care of the trauma patient.

Advanced Cardiac Life Support↗
PubMed2000

BRCA1 and BRCA2 mutation analysis of 208 Ashkenazi Jewish women with ovarian cancer.

Ovarian cancer is a component of the autosomal-dominant hereditary breast-ovarian cancer syndrome and may be due to a mutation in either the BRCA1 or BRCA2 genes. Two mutations in BRCA1 (185delAG and 5382insC) and one mutation in BRCA2 (6174delT) are common in the Ashkenazi Jewish population. One of these three mutations is present in approximately 2% of the Jewish population. Each mutation is associated with an increased risk of ovarian cancer, and it is expected that a significant proportion of Jewish women with ovarian cancer will carry one of these mutations. To estimate the proportion of ovarian cancers attributable to founding mutations in BRCA1 and BRCA2 in the Jewish population and the familial cancer risks associated with each, we interviewed 213 Jewish women with ovarian cancer at 11 medical centers in North America and Israel and offered these women genetic testing for the three founder mutations. To establish the presence of nonfounder mutations in this population, we also completed the protein-truncation test on exon 11 of BRCA1 and exons 10 and 11 of BRCA2. We obtained a detailed family history on all women we studied who had cancer and on a control population of 386 Ashkenazi Jewish women without ovarian or breast cancer. A founder mutation was present in 41.3% of the women we studied. The cumulative incidence of ovarian cancer to age 75 years was found to be 6.3% for female first-degree relatives of the patients with ovarian cancer, compared with 2.0% for the female relatives of healthy controls (relative risk 3.2; 95% CI 1.5-6.8; P=.002). The relative risk to age 75 years for breast cancer among the female first-degree relatives was 2.0 (95% CI 1.4-3.0; P=.0001). Only one nonfounder mutation was identified (in this instance, in a woman of mixed ancestry), and the three founding mutations accounted for most of the observed excess risk of ovarian and breast cancer in relatives.

Adult↗
PubMed2000

Lycopene interferes with cell cycle progression and insulin-like growth factor I signaling in mammary cancer cells.

Recent studies have shown that high insulin-like growth factor I (IGF-I) blood level is a risk factor in breast and prostate cancer. The aim of this study was to determine whether the mitogenic activity of IGF-I in mammary cancer cells can be reduced by the dietary carotenoid lycopene. The anticancer activity of lycopene, the major tomato carotenoid, has been suggested by in vitro, in vivo, and epidemiological studies. Growth stimulation of MCF7 mammary cancer cells by IGF-I was markedly reduced by physiological concentrations of lycopene. The inhibitory effects of lycopene on MCF7 cell growth were not accompanied by apoptotic or necrotic cell death, as determined by annexin V binding to plasma membrane and propidium iodide staining of nuclei in unfixed cells. Lycopene treatment markedly reduced the IGF-I stimulation of tyrosine phosphorylation of insulin receptor substrate 1 and binding capacity of the AP-1 transcription complex. These effects were not associated with changes in the number or affinity of IGF-I receptors, but with an increase in membrane-associated IGF-binding proteins, which were previously shown in different cancer cells to negatively regulate IGF-I receptor activation. The inhibitory effect of lycopene on IGF signaling was associated with suppression of IGF-stimulated cell cycle progression of serum-starved, synchronized cells. Moreover, in cells synchronized by mimosine treatment, lycopene delayed cell cycle progression after release from the mimosine block. Collectively, the above data suggest that the inhibitory effects of lycopene on MCF7 cell growth are not due to the toxicity of the carotenoid but, rather, to interference in IGF-I receptor signaling and cell cycle progression.

Anticarcinogenic Agents↗