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Moshe Inbar

Publications and source records attributed to Moshe Inbar.

27 records · Page 2Linked to original sources
PubMed2002

Effect of geminivirus infection and Bemisia infestation on accumulation of pathogenesis-related proteins in tomato.

The whitefly, Bemisia tabaci biotype B, has been shown to cause pathogenesis-related (PR) proteins to accumulate in plants as a result of direct feeding, but their specific role in plant defensive systems is unclear. Our objective was to compare accumulation of tomato PR proteins (beta-1,3-glucanase, chitinase, peroxidase, P2 and P4) in response to whitefly, with or without tomato mottle virus (ToMoV) infection. Tomato PR protein response was measured over time in plants divided into three treatments: uninfected controls (with or without whiteflies) and plants infested with viruliferous (ToMoV) whiteflies. Five- to six-leaf plants were infested with approximately 5 adult whitefly per leaf. Plants were sampled prior to whitefly infestation and at 14, 28, 42, and 56 days. By 56 days, plants infested with viruliferous whiteflies had significantly more eggs (2.5-fold) and nymphs (4.5-fold) than plants with nonviruliferous whiteflies. A significant increase in the enzymatic activity of all measured PR proteins, as compared to control plants, was only seen in viruliferous whitefly-infested plants. No significant difference was observed in enzyme activities between the uninfected control plants either with or without whiteflies. The greatest differences for all PR proteins assayed were observed 42 days after treatment initiation. Protein blot analyses showed that the differences in PR protein activities among the treatments were due to changes in specific enzyme levels within the plant and were associated with concomitant increases in levels of P2 and P4 PR proteins. Under our experimental conditions, it is clear that PR protein response is much more intense when it is attacked by whiteflies carrying ToMoV than by whitefly alone.

Animals↗
PubMed2002

Multitrophic interactions of the silverleaf whitefly, host plants, competing herbivores, and phytopathogens.

Our laboratory found that silverleaf whitefly (SLW; Bemisia argentifolii Bellows & Perring) feeding alters host plant physiology and chemistry. The SLW induces a number of host plant defenses, including pathogenesis-related (PR) protein accumulation (e.g., chitinases, beta-1,3-glucanases, peroxidases, chitosanases, etc.). Induction of the PR proteins by SLW feeding occurs in various plant species and varieties. The extent and type of induction is dependent on a number of factors that include host plant growing conditions, the length of time the host plant is exposed to SLW feeding, the plant variety, and SLW population densities. The appearance of PR proteins correlates well with reduced infestations of conspecific insect herbivore competitors. Greenhouse and field experiments in which herbivore competitors (cabbage looper, Trichoplusia ni; leaf miner, Liromyza trifolii) were placed on plants previously exposed to SLW feeding demonstrated behavioral differences (oviposition, feeding preferences) and reduced survival rates and development times of these insects. The interaction was asymmetrical, i.e., SLW infestations of plants previously exposed to leaf miners had little or no effect on SLW behavior (oviposition). Induction of plant-defensive proteins by SLW feeding was both local (at the feeding site) and systemic (uninfested leaves distant to the feeding site). There are interactions between diseases such as tomato mottle virus (ToMoV; a geminivirus) and the host plant and SLW. PR proteins were induced in tomato plants infected with ToMoV much as they were via non-viruliferous SLW feeding. The presence of ToMoV in tomato plants significantly increased the number of eggs produced by SLW females. Experiments using tomato plants, powdery mildew (PM), and tobacco mosaic virus (TMV) show that whitefly infestations can affect plant pathogen relationships but the effects vary among pathogen types. Enzyme analyses prior to pathogen inoculation showed that whitefly treatment significantly increased the activities of foliar chitinase and peroxidase. Evaluation of pathogen growth 3 weeks after inoculation showed that whitefly feeding significantly reduced the incidence of PM. However, TMV levels evaluated by ELISA were not significantly affected by whitefly feeding. Six weeks after inoculation with pathogens, the chitinase and peroxidase activities were still elevated in plants initially fed on by whiteflies but continuing pathogen infection had no effect on these enzymes. The possibility that geminivirus infection and/or SLW infestations isolate the host plant for the selected reproduction of the virus and the insect is discussed. Multitrophic cascade effects may contribute to the successful eruptive appearance of SLW on various crops, ranking them as a major pest. They may explain the general observation that when SLW infest a host plant there are few if any competing insect herbivores and pathogens found in the host. However, the results indicate that certain SLW-virus relationships could be mutualistic.

Animals↗
PubMed2002

Lack of ErbB-2 oncogene product overexpression in soft tissue sarcomas.

The c-erbB-2 gene and its products (also designated HER-2 and c-neu) encode for a 185-kd transmembrane glycoprotein with intracellular tyrosine kinase activity. c-erbB-2 belongs to the epidermal growth factor receptor family, of which there are four known members, and has molecular homology to the epidermal growth factor receptor. It seems that this family is critical in control of growth, differentiation, and mobility of many normal and transformed epithelial cell types. We have looked for overexpression of c-erbB-2 gene product in paraffin-embedded material from 230 cases of soft tissue sarcoma, in order to establish a possible new prognostic marker and a potentially new treatment option. In all the cases, irrespective of the sarcoma histological type, the immunostaining for erbB-2 was negative. Applications of erbB-2 for prognostication as well as the option of receptor targeting by trastuzumab monoclonal antibodies were aborted.

Adolescent↗
PubMed2002

A possible role for IVIg in the treatment of soft tissue sarcoma: a clinical case and an experimental model.

A patient with a malignant peripheral nerve sheath tumor (MPNST) was treated with IVIg for multiple sclerosis. Her MPNST course was remarkably longer and more indolent than expected; she achieved a disease-free interval (DFI) of 30 months. Seven other patients, who were not treated by IVIg, had a relatively aggressive course (median DFI 3 months). These results led us to examine the effect of IVIg on the growth of sarcoma in vitro and in vivo in an experimental model of MCA-bearing mice. When added to MCA-105 sarcoma cell cultures, IVIg produced a dose-dependent inhibitory effect on [(3)H]-thymidine incorporation. The maximal inhibitory effect was at a concentration of 50 mg/ml IVIg. Cell cycle analysis revealed a hypodiploid peak at the lower fluorescence values which appeared in the samples treated with IVIg. These results demonstrate that the anti-proliferative activity results from an apoptotic effect of IVIg on the tumor cells. In a second set of experiments, we evaluated the capability of IVIg, when administered orally or subcutaneously, to inhibit the growth of MCA-105 sarcoma lung metastases. A decrease in the mean lung weight was observed in the mice that were treated by s.c. or oral administration, the latter being more effective. A possible role for IVIg in the treatment of MPNST and other soft tissue sarcomas is suggested.

Animals↗
PubMed2002

Role of (18)F-FDG dual-head gamma-camera coincidence imaging in recurrent or metastatic colorectal carcinoma.

UNLABELLED: (18)F-FDG PET has been shown to be of high diagnostic accuracy for the evaluation of recurrent colorectal cancer. However, the limited availability of PET scanners precludes (18)F-FDG assessment of many patients for whom the study is indicated. An alternative is the SPECT system in coincidence mode. The aim of this study was to determine the role of dual-head camera (18)F-FDG coincidence imaging (DHC (18)F-FDG) in patients with recurrent colorectal cancer. METHODS: Sixty-seven DHC (18)F-FDG studies were performed on 62 patients with suspected recurrent colorectal cancer. Reports of contemporary CT were available for the purpose of correlation for 61 of the studies. The final diagnosis of the imaging findings was based on histology or clinical and imaging follow-up of at least 6 mo. RESULTS: In lesion-based analysis, 103 tumor sites were suspected on DHC (18)F-FDG, CT, or colonoscopy. Ninety-three of them were found to be true tumor sites. For DHC (18)F-FDG, the sensitivity was 88%, specificity was 80%, positive predictive value (PPV) was 98%, negative predictive value (NPV) was 42%, and accuracy was 87%. For CT, the sensitivity was 63%, specificity was 10%, PPV was 85%, NPV was 3%, and accuracy was 57%. In patient-based analysis, DHC (18)F-FDG differentiated patients with recurrent cancer from disease-free patients with a sensitivity of 91%, specificity of 73%, PPV of 94%, NPV of 62%, and accuracy of 88%. DHC (18)F-FDG detected tumor sites in 12 (67%) of 18 patients with elevated carcinoembryonic antigen and negative CT findings. CONCLUSION: DHC (18)F-FDG is an adequate readily available technique for assessment of recurrent colorectal cancer and has a diagnostic accuracy better than that of CT.

Adult↗
PubMed2002

[Hormone replacement therapy in breast cancer survivors: the Israeli Society for Clinical Oncology and Radiotherapy policy letter].

The Israeli Society for Clinical Oncology and Radiotherapy requested that experts in breast cancer therapy assess the Society's policy regarding the use of hormone replacement therapy (HRT) in breast cancer survivors. The following recommendations are based on updated literature, which is limited since it summarizes only retrospective data. There is currently no evidence of an increased risk of breast cancer recurrence, death attributable to cancer, or overall mortality among breast cancer survivors who use HRT. We therefore recommend that there is no need to avoid HRT in women with menopausal symptoms who are interested in receiving such treatment, as long as ovarian ablation does not play a major role in their adjuvant therapy. Women should be informed about the limitations of available data. There are some concerns regarding the use of HRT in patients whose tumors developed while undergoing HRT and in such cases treatment should be reserved only for those with severe menopausal symptoms. For women with milder symptoms or those who are not interested in HRT, other treatment options should be outlined. The policy should be updated according to future publication of results from ongoing randomized prospective studies.

Breast Neoplasms↗
PubMedDate not supplied

Sarcoma and thyroid disorders: a common etiology?

We have recently observed that many of our sarcoma patients presented also with thyroid disorders. Literature data are almost unavailable on this topic. The relationship between the sarcoma and thyroid disorders is examined. Retrospective analysis of files of patients with sarcoma and clinically overt thyroid disorders was carried out. Of the 375 patients with soft tissue sarcomas (STS) and 235 with bone sarcoma (BS) including small blue round cell tumors (SBRC), 28 patients (4.6%) had an associated significant thyroid disorder. The types of sarcoma were mainly liposarcoma followed by malignant fibrous histiocytoma, leiomyosarcoma and bone sarcoma. The primary sites were mainly limb and trunk. The interval between the diagnosis of the thyroid disorder and the sarcoma varied between -14 years (thyroid first) and +16.5 years (thyroid later) with a median of -0.2 years. Thyroid disorders included goiter, thyroiditis and carcinoma. There are both basic-science and clinical evidence to a possible common pathway that leads to the association between overt thyroid disorders and sarcomas of bone or soft tissues. Oncogene erbA activity is related to thyroid receptors to T3 and to development of sarcoma. Cross talk of the sarcoma oncogene and the erbA might contribute to the development of sarcoma. The thyroid hormone receptor and the highly related viral oncoprotein v-erbA are found exclusively in the nucleus as stable constituents of chromatin. It has been shown that v-erbA can block the spontaneous differentiation in erythroid cells transformed by various retroviral oncogenes. V-erbA can alter the spectrum of neoplasia induced by the v-src oncogene, which causes predominantly sarcomas and erythroblastosis in chicks. The erbA can cooperate with other oncogenes such as v-erbB or with v-fms, v-ras, and c-kit. Cooperation with v-myc may play a role in the development of rhabdomyosarcoma especially in thyroid hormone deficiency state. The possible clinical implications are the need to screen patients with sarcoma to thyroid disorders, and patients with thyroid disorders for malignant diseases.

Adult↗
PubMedDate not supplied

Induction chemotherapy for bone sarcoma in adults: correlation of results with erbB-4 expression.

Tumor response to preoperative chemotherapy is an important prognostic factor for localized, operable extremity osteosarcoma. Other clinical variables include tumor size and location, age and sex, and serum enzymes. Advances in molecular oncology yielded a second group of factors such as multidrug resistance status, loss of heterozygosity of RB gene, and HER2/erbB-2 expression. The aim of this study was to investigate the expression and the prognostic value of the newly described erbB-4 receptor in specimens from adults with bone sarcomas treated by pre- and postoperative chemotherapy. Thirty-three patients with non-metastatic bone sarcoma have been treated by two doxorubicin-based induction chemotherapy regimen, followed by limb sparing surgery and tailored adjuvant chemotherapy. Pre-chemotherapy tissue specimens were investigated for the expression of erbB-4 receptor and post-induction specimens were assessed for pathological response. The clinical response rates were 32-36%. The degree of induced necrosis was correlated with the disease-free survival (DFS). Patients achieving >/=90% necrosis had an improved DFS over patients with poor histological response. ErbB-4 expression was significantly associated with poor histologic response and shorter DFS. ErbB-4 expression may be used for prognostication of adults with bone sarcomas.

Adult↗