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Biomedical subjects

O Kaplan

Publications and source records attributed to O Kaplan.

At least 19 recordsLinked to original sources
PubMed2006

Mild hydrolysis of nitriles by Fusarium solani strain O1.

High levels of an aromatic nitrilase (about 37 microkat/L culture) were induced in Fusarium solani O1 after transfer of the mycelium from a rich medium into a medium with 20 mmol/L picolinonitrile. The mycelium was entrapped in lense-shaped particles consisting of a polyvinyl alcohol/polyethylene glycol copolymer (LentiKats). The cell-free extract was immobilized by hydrophobic binding onto a Butyl Sepharose column. The enzyme was useful for the mild hydrolysis of nicotinonitrile, isonicotinonitrile and benzonitrile.

Aminohydrolases↗
PubMed2004

The relation between latent inhibition and symptom-types in young schizophrenics.

Latent inhibition (LI), retarded conditioning to a stimulus that has been previously repeatedly presented without reinforcement, was examined in young schizophrenics and normal controls using a within-subject visual search task. Healthy controls exhibited the usual LI effect. LI was potentiated in schizophrenics who simultaneously exhibited high levels of negative symptoms and low levels of positive symptoms. Schizophrenic groups with other combinations of positive and negative symptoms did not differ from controls. The pattern of data suggests that past inconsistencies in the LI-schizophrenia literature may be the result of opposing processes that are associated with positive and negative symptoms.

Adolescent↗
PubMed2004

Detection of cancer cells in the axillary drainage using RT-PCR after operations for breast cancer.

The object of this study was to examine whether MUC-1 can be detected in the axillary lymphatic drainage of patients who have undergone conservative surgery for breast cancer and to assess the correlations between the presence of MUC-1 and prognostic factors in breast cancer. Sixty-eight women with invasive ductal carcinoma of the breast underwent wide local excision and axillary lymph node dissection. Axillary drains were inserted in all these cases, and the presence of MUC-1 and beta-actin was evaluated by RT-PCR in the lymphatic fluid collected after the operation. Prognostic factors included tumour size and grade, vascular and lymphatic invasion, clearance margins of the resected specimens and status of the axillary lymph nodes. RT-PCR assays for MUC-1 in the axillary fluid were positive in 17 patients (25%). The presence of MUC-1 was associated with increased tumour size and showed a positive correlation with axillary lymph node metastases and incomplete resection of the tumour. RT-PCR can disclose cancer cells in the axillary fluid after conservative surgery for breast cancer. The presence of MUC-1 in the axillary drainage may be associated with poor prognostic features, and its detection may have implications for therapy as it suggests that re-excision should be considered.

Axilla↗
PubMed2002

Portal vein air embolization after blunt abdominal trauma: a case report and review of the literature.

Gas in the portal vein is a rare and often fatal condition in surgical patients. However, the presence of gas in the mesenteric and portal veins in association with abdominal trauma is a transient incidental finding that resolves spontaneously. We describe a young patient with Crohn's disease who suffered air embolism of the portal veins secondary to blunt abdominal trauma. The condition was clinically benign and resolved spontaneously. The pathogenesis is discussed and a review of the literature is provided.

Abdominal Injuries↗
PubMed2001

Performance on the visual search analog of latent inhibition is modulated by an interaction between schizotypy and gender.

Two experiments examined the visual search analog of latent inhibition (LI) and the novel popout (NPO) effect in healthy humans. In Experiments 1 (n=48) and 2 (n=180), subjects judged the positions (left or right side of a computer screen) of a unique target amongst a field of homogeneous distractors. In both experiments, there was a strong LI effect, as indicated by longer response times (RT) to those displays in which the target was previously a distractor and the distractors were previously the target, as compared with displays in which the target was novel and the distractors were previously the target. NPO, faster RT to a display in which the target was novel on a background of familiar distractors than to a display in which both target and distractors were novel, was not obtained. In Experiment 1, LI magnitude was not affected by gender. In Experiment 2, LI magnitude was larger for low schizotypal females than for high schizotypal females, a result not obtained for males. This pattern is similar to one reported for medicated schizophrenic out-patients (Lubow, R.E., Kaplan, O., Abramovich, P., Rudnick, R., Laor, N., 2000. Visual search in schizophrenics: latent inhibition and novel popout effects. Schizophr. Res., in press). Together, these data suggest that the LI deficits found in high schizotypal healthy subjects and in schizophrenic patients represent a dysfunction that is characterized by an inability to reduce attention allocated to irrelevant stimuli, and that this may serve as a trait marker for some subtypes of schizophrenia, particularly those associated with female gender.

Adolescent↗
PubMed2001

[Photodynamic therapy of nasal basal cell carcinoma].

Photodynamic therapy (PDT) is a noninvasive modality used topically for several skin cancers. We evaluated the effects of PDT on basal cell carcinoma (BCC) of the nose, using aminolevulinic acid (ALA) as a photosensitizer and a non-laser light source (Versa-Light). The advantages of this light source are synergistic, hyperthermia and fewer side effects. A paste of 20% ALA was applied topically to biopsy-proven BCC of the nose. Lesions were covered with occlusive light-shielding dressing and after 18 hours they were submitted to 10 minutes of exposure to the light. Initial evaluation was made after 21 days and every 3 months thereafter. Patients who did not respond after 2 treatments were referred for surgery. Mean follow-up in 31 patients was 19 months (range 6-36). There were no significant side-effects. There was complete response in 24/27 (88.9%), in whom there was recurrence in 2/27 (7.4%).

Administration, Topical↗
PubMed2001

Effects of intravenous gamma immunoglobulins treatment on severe peritonitis in rats.

BACKGROUND: Generalized purulent peritonitis is characterized by an early exposure of the immune system to a large number of bacterial antigens. The hypothesis that intravenous IgG treatment may improve the outcome of severe experimental peritonitis was studied. METHODS: Peritonitis was induced in rats by cecal ligation and perforation. Continuous intravenous fluid infusion, broad-spectrum antibiotics, and twenty-four hours treated forty rats after the induction of the disease they were re-operated and the perforated cecum was excised. Twenty of these animals received in addition specific rat IgG in two intravenous infusions (0.4 gr./kg), two and twenty four hours after the induction of peritonitis. RESULTS: Elevated WBC counts and mild metabolic acidosis was found one day after the induction of peritonitis. IgG treatment was associated with lower WBC counts in the following days and with higher pH than in the control group (p < 0.05 for both parameters). All peritoneal cultures and 90% of blood cultures were positive 24 hours after the initial operation. These rates decreased in the following days and in the IgG treatment rats the peritoneal cavity and blood were sterile earlier than in the control animals (p < 0.05). Serum IgG was depleted in the control animals within 48 hours after the induction of peritonitis, while in the IgG treated animals its levels were remarkably elevated. IgG administration significantly improved the survival, which was 70% in the IgG treatment rats as compared to 40% in the control rats. CONCLUSION: These results indicate that intravenous IgG has beneficial effects on severe experimental peritonitis.

Animals↗
PubMed2000

Visual search in schizophrenia: latent inhibition and novel pop-out effects.

A visual search task was used to assess attentional function in a mixed group of schizophrenic patients and in normal controls. Subjects identified presence or absence of a unique shape presented with homogeneous distractors. Response time (RT) was examined as a function of prior experience with target, distractor, or both. On each trial, targets and/or distractors were either novel or familiar. Schizophrenic patients were slower than controls in all conditions. In the test phase, three target/distractor conditions were examined (PE - target and distractors pre-exposed but reversed; NPE - target novel and distractors pre-exposed; NOV - novel target and distractors). As predicted, normal controls, but not schizophrenics, showed latent inhibition (LI: PE minus NPE). The latter finding was due to the absence of normal LI in female patients. A novel pop-out effect (NOV minus NPE) was obtained which did not interact with any of the other variables. The results suggest that the LI effect is indeed related to the processing of irrelevant stimuli, and that, at least female schizophrenic patients process such stimuli differently from controls. Past inconsistencies in the LI-schizophrenia literature may be the result of disproportionate gender compositions in patient and control groups.

Adult↗
PubMed2000

Noninvasive real-time monitoring of intracellular cancer cell metabolism and response to lonidamine treatment using diffusion weighted proton magnetic resonance spectroscopy.

We have used diffusion-weighted proton magnetic resonance spectroscopy (DWMRS) to noninvasively selectively observe only the intracellular metabolites of breast cancer and melanoma cell lines in vitro in real time. Breast cancer cell lines representing different stages in breast cancer progression were chosen for study. Intracellular biochemical profiles of six cell lines perfused in alginate beads were obtained. Spectral differences between groups of cell lines, including choline, lactate, and threonine peaks, were investigated. We also monitored response to the antineoplastic agent, lonidamine (LND), as a function of time and drug concentration in perfused cancer cells. Previous studies reported that this drug induced intracellular acidification and lactate accumulation. Diffusion weighted proton spectra demonstrated a 2- to 9-fold increase in the intracellular lactate signal as a response to LND treatment in several cancer cell lines. These results are consistent with the hypothesis that the principal mechanism of LND in some cancer cells is marked inhibition of lactate transport. Moreover, we have shown that there is a factor of two to three between the response of melanoma cells and that of some types of breast cancer cells. The higher sensitivity of the melanoma cells, as predicted by proton DWMRS, was correlated with changes in water-suppressed magnetic resonance spectra and confirmed by a biological assay. This study demonstrates the feasibility of using DWMRS for monitoring intracellular metabolism and for studying the effects and mechanisms of action of anticancer drugs. We believe that this method can be used for noninvasive clinical applications, such as the differentiation between benign and malignant tissue, real-time monitoring of response to therapy, dose response, and toxicity effects.

Animals↗
PubMed2000

Octreotide treatment in patients with severe acute pancreatitis.

We investigated the effect of octreotide in the treatment of severe acute pancreatitis in a case-control study. Experimental and clinical studies on the effect of octreotide in the treatment of acute pancreatitis have shown controversial results. Since January 1992, we have been conducting a prospective randomized study on the effect of octreotide in severe acute pancreatitis, in three hospitals in Israel. The entering criteria included three or more of the Ranson prognostic signs and CT findings of severe pancreatitis. Patients were randomly assigned to conservative treatment either with or without octreotide (0.1 mg subcutaneously three times a day). The end points of the study included: complication rate (ARDS, sepsis, renal failure, pseudocyst, fistula, and abscess), length of hospital stay, and mortality. From January 1992 to December 1996, 60 patients entered the study. After evaluating the files, 10 patients were excluded due to failure to meet the entering criteria, incomplete data, or incorrect diagnosis. Of the remaining 50 patients, 25 were assigned to octreotide (treatment group) and 25 to conservative treatment only (control group). The two groups matched with regard to age, sex, etiology, and severity of the disease. The complication rate was lower in the treatment group with regard to sepsis (24% vs 76%, P = 0.0002) and ARDS (28% vs 56%, P = 0.04). The hospital stay was shorter in the treatment group (20.6 vs 33.1 days, P = 0.04). Two patients died in the treatment group and eight in the control group (P < 0.019). These results suggest that octreotide may have a beneficial effect in the treatment of severe acute pancreatitis.

Adult↗
PubMed2000

The effects of somatostatin and octreotide on experimental and human acute pancreatitis.

The role of somatostatin and octreotide for AP has been studied for two decades, yet the data still remain inconclusive. The inconsistencies of the results of experimental studies and clinical trials may stem from the fact that the optimal therapeutic modality has not been determined. Furthermore, although they are similar in structure and physiologic activities, the mechanisms of action and effects of somatostatin and octreotide in AP may be different. Because the data are sparse, most reports, primarily those in the English literature, on the efficacy of somatostatin and octreotide in the management of AP were reviewed. Included are both nonrandomized and prospective, double-blind, clinical trials and studies on the effects of these agents on various experimental models of the disease. The results of the studies on somatostatin and octreotide are presented and discussed separately, with specific reference to the experimental and treatment details. The main focus of the review is the effect of subcutaneous and intravenous administration of octreotide. Analysis of the data suggests that somatostatin could not be recommended for AP and that the efficacy of subcutaneous administration of octreotide is also questionable. Theoretically, intravenous octreotide may be more appropriate for this condition, but recent results with this therapeutic method are limited and contradictory. Studies that would delineate the optimal therapeutical modality and the patient population most likely to respond to the treatment are prerequisite for large-scale clinical trials on the effects of octreotide on human pancreatitis.

Acute Disease↗
PubMed2000

Return visits to the emergency room after minor trauma from motor vehicle accidents.

Most patients with minor trauma following motor vehicle accidents (MVAs) are discharged from the emergency room (ER) of a trauma centre after evaluation and observation. Some return with similar or additional symptoms. This study aimed to determine which patients returned, if any injuries had been missed, and what should be the policy of medical management. We reviewed the records of 8836 patients with minor trauma following MVAs who were examined in an inner city trauma centre during 1997. When the group of patients who returned to the emergency room (n = 160) was compared with the whole post-MVA minor trauma group, the former was found to have more males (75.6% vs. 55.9%), younger age (36.31 years vs. 39.72 years), more motorcyclists than drivers, passengers and pedestrians ( p < 0.002, for the three variables), and had more multi-site injures. During the return visits the patients stayed longer in the emergency room, were examined by more consultants and had repeated radiological evaluations and tests, compared with the initial visit. However, in none of the patients was the initial diagnosis revised nor were additional injuries found and consequently the initial management was not changed in any of them. It is concluded that the initial thorough evaluation by the primary traumatologist is adequate for MVA patients with minor trauma. These patients do not require any follow up in specialized clinics, and are best managed in the community by their general practitioners.

Accidents, Traffic↗
PubMed2000

Photodynamic therapy of murine colon cancer and melanoma using systemic aminolevulinic acid as a photosensitizer.

BACKGROUND: Side effects of conventional photosensitizers, such as hematoporphyrins, are a limiting factor in the use of photodynamic therapy (PDT). We evaluated the effect of PDT on mice colon carcinoma and melanoma using systemic 5-aminolevulinic acid (ALA). METHODS IN VITRO STUDIES: CT26 colon carcinoma and B16 melanoma cells were incubated with ALA for 48 h. Subsequently, cells were subjected to photoradiation at 40, 60 and 100 J/cm2 and viability was assessed. In vivo studies: Balb/C mice were injected subcutaneously with 2x10(5) CT26 colon cancer cells and C57/Bl mice were injected subcutaneously with 2x10(5) melanoma cells. ALA 60 mg/kg was injected intra-peritoneally when tumors were visible. After 24 h mice were subjected to photoradiation (100 J/cm2). RESULTS IN VITRO STUDIES: There was a significant decrease in the viability of treated cells as compared with non-treated tumor cells and with treated splenocytes (p<0.001). In vivo studies: PDT induced necrosis of both tumors. PDT also significantly prolonged the survival of the treated mice (p<0.05). CONCLUSIONS: Photodynamic therapy using systemic ALA as a photosensitizer was effective in treating mice colon cancer and melanoma in both in-vitro and in-vivo studies. Further pre-clinical and clinical studies are being conducted now.

Aminolevulinic Acid↗
PubMed1999

Elevated expression of the CC chemokine regulated on activation, normal T cell expressed and secreted (RANTES) in advanced breast carcinoma.

Breast carcinoma is the most common malignant disease among women and the second most lethal one. In search for a better understanding of the role of cellular mediators in the progression of this disease, we investigated the potential involvement of the CC chemokine Regulated on Activation, Normal T Cell Expressed and Secreted (RANTES) in breast carcinoma progression. To this end, RANTES expression was determined in breast tumor cell lines and in sections of breast carcinomas, followed by analysis of the incidence and intensity of its expression in different stages of the disease. Our study reveals that high and physiologically relevant levels of RANTES are constitutively produced by T47D and MCF-7 breast tumor cell lines. Analysis of RANTES expression in sections of breast carcinomas demonstrates a high incidence of RANTES expression in epithelial tumor cells; the chemokine was expressed in 74% of the sections. RANTES expression was rarely detected in normal duct epithelial cells or in epithelial cells that constitute benign breast lumps, which were located in proximity to tumor cells. High incidence and intensity of RANTES expression were detected in sections of most of the patients with stage II and stage III of the disease (expression was detected in 83 and 83.3%, respectively), whereas RANTES was expressed at a lower incidence and intensity in sections of patients with stage I of breast carcinoma (55% of the cases). Most importantly, the expression of RANTES was minimally detected in sections of patients diagnosed with benign breast disorders and of women that underwent reduction mammoplasty (15.4% of the cases). These results indicate that the expression of RANTES is directly correlated with a more advanced stage of disease, suggesting that RANTES may be involved in breast cancer progression. Moreover, it is possible that in patients diagnosed with benign breast disorders, RANTES expression may be indicative of an ongoing, but as yet undetectable, malignant process.

Adenocarcinoma↗
PubMed1999

The effects of target and distractor familiarity on visual search in de novo Parkinson's disease patients: latent inhibition and novel pop-out.

De novo Parkinson's disease (PD) patients identified presence or absence of a unique shape presented with homogeneous distractors. Response time (RT) was examined as a function of prior experience with target and/or distractor assessing latent inhibition (LI; slower RTs to a target that was formerly a distractor against a background of distractors that were formerly targets as compared with a novel target with distractors that were formerly targets) and novel pop-out effects. PD patients were slower than controls in detecting test-phase targets compared with preexposure-phase targets. Female PD patients with right-side motor symptoms had elevated LI compared with female controls and female PD patients with left-side symptoms. Male PD patients with right-side symptoms did not exhibit LI. Results are discussed in terms of the dopamine hypothesis and the reciprocal relationship between PD and schizophrenia.

Exploratory Behavior↗