Biomedical subjects

V Barak

Publications and source records attributed to V Barak.

131 records · Page 8Linked to original sources

PubMedDate not supplied

Short-term systemic effects of head and neck irradiation.

BACKGROUND: Various localized side effects which accompany head and neck irradiation [IR] have been widely reported. However, systemic side effects/have been only sparsely reported in the short-term period post-IR in an animal model. The potential modulatory role of zinc-desferrioxamine [Zn-DFO] on IR effects was examined because of its known ability to protect against the damage induced by free radicals which are mediated by redox-active metal ions. MATERIALS AND METHODS: We used three groups of male Wistar rats: a] sham irradiated controls b] irradiated [15 Gy]; c] irradiated and treated with Zn-DFO [20 mg/k] one hour prior to IR. During the first two weeks post-IR, body weight and food and water intake were monitored daily, while lymphocytes, segmented neutrophils and white blood cells [WBC] were counted at 10 minutes 4 and 16 hours and 1, 3, 7 and 14 days. Serum TNF-a and IL-6 were obtained at 10 minutes and 7 days. RESULTS: On day 7 post-IR, body weight and food and water intake were reduced by 84% 96% and 85% [p < 0.01], respectively in the above mentioned three groups of rats. This resulted in the death of 22% of the animals and was followed by recovery towards the end of the second week. At all time points examined between 10 minutes and 14 days, WBC were reduced by 52-74%. On the 7th day, Zn-DFO demonstrated a 33% protective effect against the WBC reduction. At 10 mins post-IR, a 84.8-fold [p < 0.01] increase of TNF-alpha, but not IL-6, was noted. However, on the 7th day post-IR, both TNF-alpha and IL-6 levels were increased by 48.5-fold and 102.5-fold [0.01], respectively. CONCLUSION: The data presented delineate the severe short-term systemic effects of head and neck IR in a rat model. We suggest considering the severe cachectic and immunocompromised status of the animals when performing various short-term studies with this model. During this period nutritional and immunological support for the examined animals is recommended. Further evaluation of the underlying mechanisms of IR-induced leukopenia and cachexia in animals and the possible implications for humans is warranted.

Animals↗

PubMedDate not supplied

The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines.

Sambucus nigra L. products - Sambucol - are based on a standardized black elderberry extract. They are natural remedies with antiviral properties, especially against different strains of influenza virus. Sambucol was shown to be effective in vitro against 10 strains of influenza virus. In a double-blind, placebo-controlled, randomized study, Sambucol reduced the duration of flu symptoms to 3-4 days. Convalescent phase serum showed a higher antibody level to influenza virus in the Sambucol group, than in the control group. The present study aimed to assess the effect of Sambucol products on the healthy immune system - namely, its effect on cytokine production. The production of inflammatory cytokines was tested using blood - derived monocytes from 12 healthy human donors. Adherent monocytes were separated from PBL and incubated with different Sambucol preparations i.e., Sambucol Elderberry Extract, Sambucol Black Elderberry Syrup, Sambucol Immune System and Sambucol for Kids. Production of inflammatory cytokines (IL-1 beta, TNF-alpha, IL-6, IL-8) was significantly increased, mostly by the Sambucol Black Elderberry Extract (2-45 fold), as compared to LPS, a known monocyte activator (3.6-10.7 fold). The most striking increase was noted in TNF-alpha production (44.9 fold). We conclude from this study that, in addition to its antiviral properties, Sambucol Elderberry Extract and its formulations activate the healthy immune system by increasing inflammatory cytokine production. Sambucol might therefore be beneficial to the immune system activation and in the inflammatory process in healthy individuals or in patients with various diseases. Sambucol could also have an immunoprotective or immunostimulatory effect when administered to cancer or AIDS patients, in conjunction with chemotherapeutic or other treatments. In view of the increasing popularity of botanical supplements, such studies and investigations in vitro, in vivo and in clinical trials need to be developed.

Humans↗

PubMedDate not supplied

Effects of retinoic acid and phorbol ester on lymphocytes and monocytes in B-lymphocytic leukemia.

PBMC concentrated from 12 patients with CLL were incubated for up to 6 days with various doses of TPA or RA in an attempt to induce differentiation. The results show a great heterogeneity in the cellular response to both inducers. TPA produced two major changes in B-CLL cells, namely the development of some hairy-cell leukemia features with an increase in Ig secretion and the expression of Leu M5 and TAC receptors. In contrast to TPA, RA induced only modest or no changes in surface, but increased numbers of large macrophages were seen as assessed by latex-bead ingestion, expression of Fc receptors and cytochemistry. These changes were more obvious after exposure to RA than to TPA. Thus, while TPA induces mostly differentiation and hairy-cell features in B-lymphocytes, RA induces activation of the monocyte pool with no obvious changes in the lymphocytic compartment.

Acid Phosphatase↗

PubMedDate not supplied

CA15-3 serum levels in breast cancer and other malignancies--correlation with clinical course.

Serum levels of the breast cancer-associated tumor marker CA15-3 were evaluated in three patient groups: breast, colorectal and ovarian cancer and in healthy subjects. Of 51 blood samples obtained from 31 patients with metastatic breast cancer (Stage IV disease), 98% had marker levels greater than 30 u/ml and 86% had levels greater than 50 u/ml. In contrast, of 49 samples from 42 patients with Stage I-II disease, 45% had levels greater than 30 u/ml but only 6% had levels greater than 50 u/ml (mean 29.5 +/- 18 u/ml). The mean level of the CA15-3 antigen in patients with Stage IV breast cancer and responding to therapy was 79.8 +/- 27 u/ml, while the mean level in patients not responding to therapy was 134 +/- 66 u/ml (P less than 0.02). The mean serial changes in CA15-3 levels for those responding to therapy was -28.4% while the mean change for those not responding to therapy was +44%. The mean marker level for 26 patients with colorectal carcinoma was 29.8 +/- 29 u/ml; 23% of these patients had levels greater than 30 u/ml and 7% had levels greater than 50 u/ml. No substantial difference was seen in those with active compared with nonactive colorectal carcinoma. The mean marker level for 14 patients with active ovarian carcinoma was 83 +/- 62 u/ml. Of these patients, 78% had CA15-3 levels greater than 30 u/ml and 50% had levels greater than 50 u/ml. All healthy subjects (n = 22) had marker levels less than 30 u/ml. We compared CA15-3 and CEA blood levels in the same patient population; 86% of patients with metastatic breast cancer (Stage IV disease) had CA15-3 levels greater than 50 u/ml while only 72% of these patients had CEA levels greater than 5 ng/ml. These findings suggest that the CA15-3 assay reflects the clinical course of patients with advanced breast cancer and may be superior to CEA as a monitor of therapeutic efficacy.

Antigens, Tumor-Associated, Carbohydrate↗

PubMedDate not supplied

Screening for prostate cancer.

In an attempt to detect prostate cancer when the tumor is still confined to the prostate, a screening program was established. We studied the efficacy of digital rectal examination (DRE) and serum prostate-specific antigen (PSA) in the early detection of prostate cancer. One thousand men aged 50-75 years underwent DRE and serum PSA determination. Transrectal ultrasound-guided biopsies were obtained in each case of a suspicious DRE. Six systematic biopsies were performed if the PSA level was > 10 ng/ml, even if DRE and transrectal ultrasonography revealed no areas suspicious of cancer. A suspicious DRE was noted in 11.5% of the subjects; 16% had elevated levels of serum PSA (> 4 ng/ml) and 3.9% had serum PSA > 10 ng/ml. Biopsies were obtained from 90 patients, of which 31 were positive for prostate cancer. The cancer detection rate was 2.2% for DRE, 2.0% for PSA > 10 ng/ml, and 3.1% for the two methods combined. Clinical staging revealed that in 29 of the 31 patients with prostate cancer, the tumor was confined to the prostate: Stage A in 9 cases and stage B in 20 cases. Only two patients had clinically advanced cancer, and 22 patients underwent radical prostatectomy. Pathological examination disclosed biologically significant tumors in 91% of the cases in terms of tumor volume and grade. Although there is little evidence that screening will result in the reduction of the disease-specific mortality rate, early detection of prostate cancer by DRE, serum PSA, and transrectal ultrasound should be encouraged.

Aged↗