Arsenic-trioxide-induced apoptosis of chronic lymphocytic leukemia cells.

Chronic lymphocytic leukemia (CLL) cells are characterized by defective apoptosis which leads to their extended survival. Arsenic trioxide (As(2)O(3)) was reported to induce cell death in many malignant cells, but the specific pathway of As(2)O(3)-induced apoptosis/necrosis remains controversial. Our aim was to determine if As(2)O(3) kills CLL cells through apoptosis and whether this is accompanied by reduction in Bcl-2 levels. Cells from nine patients with CLL were incubated with increasing concentrations of As(2)O(3) (0.5-2 microM) for 2, 7, or 14 days. Cells viability was measured using Alamar Blue assay and apoptosis using human Annexin V-FITC and propidium iodine (PI) kit (BMS306FI; Bender MedSystems, Vienna, Austria). Intracellular Bcl-2, Bax, and caspase-3 levels were measured by flow cytometry. As(2)O(3) significantly reduced CLL cell viability (P < 0.01) and induced apoptotic cell death in a time- and dose-dependent manner. After 7 days, CLL cells showed a significant decrease in mean fluorescence intensity (MFI) of Bcl-2 on flow cytometry study. Bax and caspase-3 levels showed significant decrease in MFI only after prolonged incubations (7 and 14 days) and mostly at higher concentrations of As(2)O(3). The mechanism underlying the reduction in viability of CLL cells incubated with As(2)O(3) is mediated by induction of apoptosis maybe through the down-regulation of Bcl-2. Further studies are needed to elucidate the potential therapeutic role of As(2)O(3) in CLL.

Vascularization of wide pore agarose-gelatin cryogel scaffolds implanted subcutaneously in diabetic and non-diabetic mice.

Polymeric scaffolds have been reported to promote angiogenesis, facilitating oxygen delivery; however, little is known about the effect of diabetes on the neo-vascularization of implanted polymeric scaffolds at subcutaneous (SC) sites. In this study we compare the effect of diabetes on scaffold vascularization following SC implantation into diabetic and non-diabetic mice. Wide pore agarose cryogel scaffolds with grafted gelatin were prepared by a two-step freezing procedure and subsequent thawing. The scaffolds were implanted subcutaneously into streptozoticin-induced diabetic mice and control, non-diabetic mice. The vascularization process was estimated using histological sections, in which endothelial cells were identified by Von Willebrand factor (vWF) and CD31 antigen staining and the pericyte layer was confirmed by alpha-smooth muscle actin (alpha-SMA) visualization. Comparative analysis showed a similar thickness of fibrous capsules around the vascularized scaffolds in both diabetic and non-diabetic animals. Intensive staining for alpha-SMA indicated the formation of mature blood vessels in the surrounding fibrous capsule and tissue invading the scaffold area. No statistically significant differences in capillary density and area occupied by blood vessels were found between diabetic and non-diabetic mice. In conclusion, the present study shows no adverse effects of diabetes on new blood vessel formation in SC implanted agarose cryogel scaffolds with grafted gelatin.

Tyrphostins reduce chemotherapy-induced intestinal injury in mice: assessment by a biochemical assay.

Intestinal injury that results from chemotherapy belongs to the major factors of dose-limitation in tumour therapy. The tyrphostins AG1714 and AG1801 reduce cisplatin and 5-FU-induced small intestinal mucosal damage, using a quantitative biochemical assay. The assay is based on the determination of the enzymatic activity of gamma-glutamyl transpeptidase, a marker of the brush border epithelium of the small intestine.

Involvement of tumor necrosis factor alpha and interleukin-1beta in enhancement of pentylenetetrazole-induced seizures caused by Shigella dysenteriae.

Neurologic manifestations, mainly convulsions, are the most frequent extraintestinal complications of shigellosis. We used an animal model to study the roles of tumor necrosis factor alpha (TNF-alpha) and interleukin-1 beta (IL-1beta) in Shigella-related seizures. Administration of Shigella dysenteriae 60R sonicate enhanced the sensitivity of mice to the proconvulsant pentylenetetrazole (PTZ) within 7 h. This was indicated by a significantly higher mean convulsion score and an increased number of mice responding with clonic-tonic seizures in the Shigella-pretreated group. Preinjection of mice with anti-murine TNF-alpha (anti-mTNF-alpha) or anti-murine IL-1beta (anti-mIL-1beta) 30 min prior to administration of Shigella sonicate abolished their enhanced response to PTZ at 7 h. Mean convulsion scores were reduced by anti-mTNF-alpha from 1.2 to 0.8 (P = 0.017) and by anti-mIL-1beta from 1.3 to 0.7 (P = 0.008). Preinjection of anti-mTNF-alpha also reduced the percentage of mice responding with clonic-tonic seizures, from 48 to 29% (P = 0.002), and preinjection of anti-mIL-1beta reduced it from 53 to 21% (P = 0. 012). Neutralization of TNF-alpha or IL-1beta did not protect the mice from death due to S. dysenteriae 60R. These findings indicate that TNF-alpha and IL-1beta play a role in the very early sensitization of the central nervous system to convulsive activity after S. dysenteriae administration. Similar mechanisms may trigger neurologic disturbances in other infectious diseases.

Tyrphostin 4-nitrobenzylidene malononitrile reduces chemotherapy toxicity without impairing efficacy.

In mice, 4-nitrobenzylidene malononitrile (AG1714), which belongs to the tyrphostin family, reduced toxicity induced by doxorubicin and cisplatin without impairing their antitumor efficacy. AG1714 reduced mortality induced by doxorubicin and cisplatin. It prevented, in a dose-dependent manner, cisplatin-induced nephrotoxicity as assessed by measurement of serum creatinine and blood urea nitrogen levels. The protective effect of AG1714 was most pronounced on its administration 2 h before cisplatin. AG1714 also prevented doxorubicin-induced myelosuppression as assessed by the scoring of bone marrow nucleated cells and colony-forming units. Cisplatin-induced small intestinal injury was also protected by AG1714 as assessed by histopathological analysis. In vitro, AG1714 reduced cisplatin-induced apoptosis in a murine fibroblastic cell line (A9) and did not affect doxorubicin-induced apoptosis of B-16 melanoma cells. In contrast to its protective effect against mortality and injury of normal tissues induced by chemotherapy, AG1714 did not impair its antitumor activity and in some tumor models enhanced it. This was evident by using the murine tumors B-16 melanoma, Lewis lung carcinoma, and methylcholanthrene-induced fibrosarcoma and the human tumors SK-28 melanoma and human ovary carcinoma xenografts in nude mice. Experiments in which low and high doses of cisplatin and doxorubicin were administered to tumor-bearing mice demonstrated that AG1714 reduced mortality of high-dose chemotherapy and increased its therapeutic index. AG1714 could provide a novel, useful tool to improve chemotherapy by allowing dose intensification.

[Effectiveness of semax in acute period of hemispheric ischemic stroke (a clinical and electrophysiological study)]. / Effektivnost' semaksa v ostrom periode polusharnogo ishemicheskogo insul'ta (klinicheskoe i élektrofiziologicheskoe issledovanie).

Efficiency of Semax (synthetic derivative of ACTH-4-10) was studied in 30 patients in acute period of hemispherical ischemic stroke. Control group consisted of 80 patients with the strokes analogous in severity and location of the damages and which were treated by conventional therapy. Different clinical rating scales were used for both objectivization of the severity of the patients' state and estimation of the degree of neurological defect. The control of Semax influence on the functional state of the brain included monitoring of EEG with mapping, repeated analysis of somatosensory evoked potentials and their mapping. It was established that including of Semax in combined intensive therapy of acute ischemic stroke had some influence on the rate of restoration of the damaged neurological functions in terms of increasing the regress of general cerebral and focal, especially motor disorders. The most effective daily doses were 12 mg for patients with strokes of moderate severity and 18 mg for patients with severe strokes (treatment course--5 and 10 days).

[The metabolic therapy of ischemic stroke: the use of nootropil]. / Metabolicheskaia terapiia ishemicheskogo insul'ta: primenenie nootropila.

54 patients were treated by notropil (pyracetam). The results of therapy were evaluated statistically according to a number of clinical scales and neurophysiologic indices (EEG and evoked potentials with mapping of bioelectric activity). The results were compared with the data about 56 patients of the control group which were treated by traditional method without application of notropil. Notropil was applied by two ways: small doses (4-12 g daily) during 5 days or high doses (10-12 g daily) during 30 days from the moment when the patient admitted to the hospital. Intravenous injections of the drug were used in all cases as well as its internal administration. It was showed either efficiency of the drug, especially in high doses, in early beginning of the treatment and its duration for at least 30 days or good tolerance of the drug. Authors supposed that application of pyracetam is not adequate in strokes with severe disorders of consciousness and cerebral edema.

Late administration of a lipophilic tyrosine kinase inhibitor prevents lipopolysaccharide and Escherichia coli-induced lethal toxicity.

Septic shock induced by gram-negative bacteria results primarily from excessive stimulation by lipopolysaccharide (LPS) of macrophages to produce tumor necrosis factor (TNF)-alpha and interleukin (IL)-1. The cellular effects of LPS, TNF-alpha, and IL-1 are mediated via tyrosine phosphorylation pathways. A recent report indicated that selective inhibitors of tyrosine kinases, tyrphostins of the AG126 family, protect mice against LPS-induced lethal toxicity in mice. Protection was most effective when the tyrphostin was injected before the LPS. In the present study, tyrphostin AG556, which is more lipophilic than those of the AG126 family, was effective in preventing LPS-induced lethal toxicity when administered 2 h after LPS. AG556 also prevented viable Escherichia coli-induced lethal toxicity when given 2 h before and, to a lesser extent, 2 h after the bacterial inoculation. AG556 may block a critical step downstream of the signaling pathway induced by LPS after TNF-alpha production.

Prevention of lipopolysaccharide-induced lethal toxicity by tyrosine kinase inhibitors.

Septic shock results from excessive stimulation of the host immune system, especially macrophages, by lipopolysaccharide (LPS), or endotoxin, which resides on the outer membrane of bacteria. Protein tyrosine kinase inhibitors of the tyrphostin AG 126 family protect mice against LPS-induced lethal toxicity. The protection correlates with the ability of these agents to block LPS-induced production of tumor necrosis factor alpha (TNF-alpha) and nitric oxide in macrophages as well as LPS-induced production of TNF-alpha in vivo. Furthermore, this inhibitory effect correlated with the potency of AG 126 to block LPS-induced tyrosine phosphorylation of a p42MAPK protein substrate in the murine macrophage.

[Immunoreactive disorders and their correction in patients with rhegmatogenous retinal detachment complicated by vitreoretinal proliferation]. / Narusheniia immunoreaktivnosti i ikh korrektsiia u bol'nykh s regmatogennoi otsloikoi setchatki, oslozhnennoi vitreoretinal'noi proliferatsiei.

Examination of the immunologic state of 73 patients with rhegmatogenous retinal detachment complicated by vitreoretinal proliferation has revealed correlation between the severity of the latter and disturbances in the immune state of the patient's body. 44% of patients with the stage C and 62% of patients with the stage D have immunodeficiency expressed by reduced level of T- and B-lymphocytes and their subpopulation. It is shown that disturbances in immunoreactivity can serve as an unfavourable sign for prognosis of effectiveness of surgical intervention in patients with rhegmatogenous retinal detachment. In 70% of the patients these disturbances lead to unfavourable outcome of the operation. For normalization of the revealed disturbances in the immune state, immunomodulator thymaline was used in a complex treatment of 17 patients. The preparation rose the effectiveness of the treatment in 78% of patients and reduced the number of postoperative complications. It is recommended to study the immunologic state of the patient with rhegmatogenous retinal detachment complicated by vitreoretinal proliferation for the purpose of its further correction and a higher effectiveness of surgical treatment of such patients.

[Characteristics of the immune status of patients with uveal melanoma during the performance of organ-preserving treatment]. / Osobennosti immunnogo statusa bol'nykh uveal'nymi melanomami v protsesse provedeniia organosokhrannogo lecheniia.

The paper presents data about changes in the immune status of patients with uveal melanoma in the process of organ-preserving treatment. The presence of 2 types of reaction on the treatment are shown. They are characterized by intensification or depression of the cellular immunity, in particular of its T-cellular link. The type of reaction depends on the initial state of the immune reactivity of the body, the size of the tumor and the type of the injurious factor. The increase of immune reactivity correlates with the best clinical outcomes of the treatment. This allows to use the determination of the immune status in prognosticating the outcome of treatment.