Heterozygous deletion of mitotic arrest-deficient protein 1 (MAD1) increases the incidence of tumors in mice.

Mitotic arrest-deficient protein 1 (MAD1) is a component of the mitotic spindle assembly checkpoint. We have created a knockout mouse model to examine the physiologic consequence of reduced MAD1 function. Mad1(+/-) mice were successfully generated, but repeated paired mating of Mad1(+/-) with Mad1(+/-) mice failed to produce a single Mad1(-/-) animal, suggesting that the latter genotype is embryonic lethal. In aging studies conducted for >18 months, Mad1(+/-) mice compared with control wild-type (wt) littermates showed a 2-fold higher incidence of constitutive tumors. Moreover, 42% of Mad1(+/-) (P < 0.03), but 0% of wt, mice developed neoplasia after treatment with vincristine, a microtubule depolymerization agent. Mad1(+/-) mouse embryonic fibroblasts (MEF) were found to be more prone than wt cells to become aneuploid; Mad1(+/-), but not wt, MEFs produced fibrosarcomas when explanted into nude mice. Our results indicate an essential MAD1 function in mouse development and correlate Mad1 haploinsufficiency with increased constitutive tumors.

Effect of electroconvulsive stimulation on morphological and physiological aspects of post-cardiac arrest cerebral microcirculation.

We investigated the effect of electroconvulsive stimulation (ECS) on cerebral circulation in vivo using the method for measuring microcirculation in real time with the photosensitizer dye Photosense and the fiber optic spectrofluorometer LESA-01-BIOSPEC. We have found that electroconvulsive stimulation significantly improved cerebral microcirculation (fourfold higher comparing to the control cerebral perfusion) after 30 min of room-temperature cardiac arrest. Morphologic study of the brain tissue showed the absence of rouleaux formation of erythrocytes ("sludged blood") in the cerebral cortex microcirculation after the application of electrical stimulus. Electroconvulsive stimulation may be useful for improving cerebral microcirculation (blood flow) in cases of long-term brain hypoxia/anoxia after prolonged cardiac arrest.

A coincidence of addiction to "Kratom" and severe primary hypothyroidism.

Here we present a case of a coincidence of addiction to "Kratom" (botanically known as Mitragyna speciosa Korth) and developed severe primary hypothyroidism. We are discussing a possibility that high dose of indole alkaloid mitragynine (the major alkaloid identified from "Kratom") might reduce the normal response of the thyroid gland to thyroid-stimulating hormone resulting in primary hypothyroidism. Further experimental investigations of mitragynine as a possible suppressor of thyroid gland function would be a matter of interest.

Cardiac mitochondrial membrane stability after deep hypothermia using a xenon clathrate cryostasis protocol - an electron microscopy study.

We investigated a new cryopreservation method using xenon, a clathrate-forming gas, under medium pressure (100psi). The objective of the study was to determine whether this cryostasis protocol could protect cardiac mitochondria at cryogenic temperatures (below 100 degrees Celsius).We analyzed transmission electron microscopy images to obtain information about changes in mitochondrial morphology induced by cryopreservation of the hearts. Our data showed absence of mitochondrial swelling, rupture of inner and outer membranes, and leakage of mitochondrial matrix into the cytoplasm after applying this cryostasis protocol. The electron microscopy results provided the first evidence that a cryostasis protocol using xenon as a clathrate-forming gas under pressure may have protective effects on intracellular membranes. This cryostasis technology may find applications in developing new approaches for long-term cryopreservation protocols.

Stability and autolysis of cortical neurons in post-mortem adult rat brains.

We investigated the dynamics of autolytic damage of the cortical neurons in adult brains for 24 hours at room temperature (+20 degrees C) after cardiac arrest. The progressive histological and ultrastructural changes were documented using routine and immunohistochemical staining as well as electron microscopy. Our results demonstrated that there were no autolytic damages in the ultrastructure of cerebral neurons in the first 6 hours after warm cardiac arrest, in agreement with previous studies in other mammals. Interestingly, the activation of caspase-3 was observed in a significant number of neurons of the cerebellum and neocortex 9 hours following cardiac arrest. No significant changes related to autolysis were observed using amnio-cupric acid and Nissl (thionine) staining.

Evidence for cooperative transforming activity of the human pituitary tumor transforming gene and human T-cell leukemia virus type 1 Tax.

Aneuploidy is frequent in cancers. Recently it was found that pituitary tumor transforming gene (PTTG; also called Pds1p or securin) is overexpressed in many different tumors. Human T-cell leukemia virus type 1 (HTLV-1) is a retrovirus that primarily infects CD4+ T lymphocytes and causes adult T-cell leukemia. Here, we report that overexpression of human PTTG cooperated with the HTLV-I Tax oncoprotein in cellular transformation. Coexpression of Tax and PTTG enhanced chromosomal instability and neoplastic changes to levels greater than overexpression of either factor singularly. Cells that overexpressed both PTTG and Tax induced tumors more robustly in nude mice than cells that expressed either PTTG alone or Tax alone.

Evidence for NF-kappaB- and CBP-independent repression of p53's transcriptional activity by human T-cell leukemia virus type 1 Tax in mouse embryo and primary human fibroblasts.

The human T-cell leukemia virus type 1 (HTLV-1) Tax oncoprotein can repress the transcriptional activity of the tumor suppressor protein p53. However, it remains controversial whether Tax requires NF-kappaB factors/activity and/or p300/CBP in order to inactivate p53 function. To address this issue, we have investigated Tax's effect on p53's transcriptional activation in IkappaB-kinase-deficient mouse embryonic fibroblasts (MEFs); some of which are entirely silent for Tax-induced NF-kappaB activity. We found that, in IKKalpha-/-, IKKbeta-/-, and IKKgamma-/- MEFs, p53 activation of a prototypic responsive plasmid (pG13-luciferase) was repressed by wild-type Tax. Curiously, p53's activity in MEFs was also repressed by a p300/CBP-binding deficient Tax protein. Our results highlight the complex nature of Tax-mediated repression of p53- activity, which requires further investigation.

Photodynamic therapy with chlorin e(6) for skin metastases of melanoma.

BACKGROUND: Photodynamic therapy (PDT) has been successfully applied in clinical settings to destroy neoplasms, but the efficacy of such a treatment is dependent on the type of neoplasm and the photosynthesizer used. Here, we perform a clinical assessment of PDT for skin metastases of pigmented melanoma using chlorin e(6). STUDY DESIGN/MATERIALS AND METHODS: PDT with chlorin e(6) photosensitizer was administered to 14 patients with skin metastases from melanoma (10 females, four males, mean age 49.6 years). Chlorin e(6) at a dose of 5 mg/kg of patient's weight was intravenously injected. The treatment course consisted of two courses of PDT exposure 1 h after intravenous chlorin e(6) injection and 24 h post-injection. The light energy density for each skin tumor was 80-120 J/cm(2) per treatment, with a light power density of 250-300 mW/cm(2). RESULTS: All skin melanoma metastases that received PDT showed complete regression with no recurrence during the study period. The complete response of all skin metastases from melanoma occurred in eight cases after one PDT treatment. In the remaining six individuals, tumors required multiple PDT courses prior to complete regression. No cases of photodermatitis were registered. The Karnofsky performance scale score of the patients with skin metastases from melanoma showed no significant difference before and after PDT. No patients had significant changes in blood cell counts that would indicate chlorin e(6) systemic toxic effect. Blood chemistry and urinalysis did not show any evidence of chlorin e(6) renal and hepatic injury. CONCLUSIONS: PDT with chlorin e(6) for skin metastases from melanoma is effective and well tolerated. Further clinical investigation of PDT with chlorin e(6) is warranted.

Local chemotherapy with cisplatin-depot for glioblastoma multiforme.

Glioblastoma multiforme (GBM) makes up as many as 30% of all primary brain tumors. Despite the employment of multimodal antitumor treatment, the overall survival is less than one year. Between 06/01/1998 and 06/01/2000 17 patients (Group A) with GBM (11 males, 6 females; median age 54.3 years) were administered local chemotherapy with cisplatin incorporated into biodegradable 6-carboxylcellulose polymer (cisplatin-depot (CDDP-D)). After the subtotal removal of GBM, twenty 1.5 x 1.5 cm polymer plates with a total area of 45 cm2 (the density of cisplatin immobilization on 6-carboxylcellulose being 1 mg/cm2, a total cisplatin dose of 45 mg) were implanted into the tumor bed. Group B (21 patients with GBM; 11 males, 10 females; median age 53.2 years) was control: the subtotal tumor ablation without CDDP-D implantation. Two to three weeks after the surgery all the patients of Groups A and B started a course of radiation therapy. A total dose of cranial irradiation was 20 Gy (1 fraction/day, 5 days/week; a daily dose of 2 Gy) followed by a boost tumor bed irradiation (1 fraction/day, 5 days/week; a daily dose of 2 Gy) up to the conventional dose of 60 Gy. Survival data for the patients were processed using the Kaplan-Meier method and analyzed by logrank test. All the patients of Group A tolerated surgical ablation of the brain tumor without side effects (brain edema, seizures, etc.). No patient of Group A had a reduction in blood cell counts during six weeks that would indicate systemic exposure to cisplatin. Blood chemistry and urinalysis did not show evidence of renal injury. No side effects of radiotherapy were registered in Group B either, regarding both the psychoneurological status of the patients and the basic values of homeostasis. Karnofsky performance scale (KPS) score of Group A and Group B patients demonstrated no significant differences before and after the surgery. The median overall survivals for patients of Group A and Group B were 427.5 and 211.0 days respectively (p = 0.00001; overall logrank test). Conclusion. Local chemotherapy of GBM with CDDP-D followed by irradiation is well tolerated and effective.