Chemoprevention of 2-amino-1-methyl-6-phenylimidazo- [4,5-b]pyridine-induced colon carcinogenesis by 1-O-hexyl-2,3,5-trimethylhydroquinone after initiation with 1,2-dimethylhydrazine in F344 rats

The aim of this study is to investigate the chemopreventive effects of the synthetic phenolic antioxidant 1-O-hexyl-2,3, 5-trimethylhydroquinone (HTHQ) on 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP)-associated colon carcinogenesis in rats after initiation with 1,2-dimethylhydrazine (DMH) in male F344 rats. Groups of 20-22, 6-week-old male F344 rats were given four subcutaneous injections of 40 mg/kg body wt of DMH during the initial 4 weeks. They were then maintained on powdered basal diet containing 0.03% PhIP alone, PhIP together with 0.5 or 0.125% HTHQ, 0.5 or 0.125% HTHQ alone or basal diet for 32 weeks. A small number (1.1 +/- 1.1/rat) of colon tumors were induced by DMH treatment alone. After initiation with DMH, the number of colon tumors was greatly increased to 8.3 +/- 5.6 by the administration of PhIP. Additional treatment with HTHQ dose-dependently decreased the multiplicity of colon adenocarcinomas to 4.9 +/- 2.8 and 2.6 +/- 1.4 with 0.125 and 0.5%, respectively. This treatment similarly reduced atypical hyperplasias of the ventral prostate. Furthermore, HTHQ significantly reduced the multiplicity of duodenal adenocarcinomas induced by DMH + PhIP or DMH alone. Immunohistochemically, HTHQ was revealed to suppress PhIP-DNA adduct formation in the epithelial cells of the colon and prostate in a separate 2 weeks experiment. The present results clearly showed that HTHQ has chemopreventive potential for PhIP-associated colon and prostate carcinogenesis. The observed inhibition may largely be due to interference with PhIP-DNA adduct formation. In addition, HTHQ has been demonstrated to inhibit duodenal carcinogenesis in the post-initiation stage.     

Detergent-induced epidermal barrier dysfunction and its prevention

Various detergents are used as skin cleansing products. In some cases, skin cleanser removes not only dirt but also valuable skin lipids. Therefore, detergents may disrupt epidermal barrier function despite that using of detergents are required for good skin hygiene. Lipid supplements can reverse detergent-induced dysfunction of the skin barrier. Elevated transepidermal water loss (TEWL) and riboflavin penetration in 5% SLS-treated rat and human skin were reversed by supplementation of monoglyceride (MG), squalene (SQ), cholesterol ester (CE) and pseudo-ceramide (Cer2). MG and Cer2 achieved the best results. MG appears to inhibit elution of intercellular ceramides, since more ceramides remained when the detergent was supplemented with MG. Topical application of Cer2 is not effective for recovery from artificially induced barrier disruption, but supplemented Cer2 into skin cleanser has a beneficial effect for prevention of detergent-induced barrier disruption. In conclusion, the prevention of barrier disruption is most important matter for maintaining skin health and barrier function. Therefore, we think that Cer2-supplemented skin cleanser is useful for conservation of skin barrier function.     

Involvement of 5-HT7 receptors in serotonergic effects on spike afterpotentials in presumed jaw-closing motoneurons of rats

Supporting glial cells of the peripheral nervous system include satellite cells of dorsal root ganglia and Schwann cells of peripheral nerves. In the central nervous system, glial cells contain enzymes related to the tricarboxylic acid and glutamine cycles: pyruvate carboxylase, glutamate dehydrogenase, and glutamine synthetase. The present study used immunohistochemistry in the rat peripheral nervous system to determine the cellular distribution of these enzymes along with glutamine. In dorsal root ganglia and peripheral nerves, glutamine and glutamine related enzymes were enriched in satellite and Schwann cells. In the dorsal root ganglia, immunoreactive satellite cells surrounded neurons of all sizes. In peripheral nerve, immunoreactive Schwann cells were most easily observed surrounding large diameter, myelinated axons. These Schwann cells contained immunoreactivity in their cell bodies, nodes of Ranvier, and the rim of cytoplasm outside the myelin sheath. Myelin sheaths were non-immunoreactive. The peripheral glial tricarboxylic and glutamine cycles may be used to produce glutamine for neuronal cell uptake and conversion to glutamate for synaptic transmission. Alternatively, these cycles may function in peripheral glia similar to central nervous system astrocytes for supporting the energy demands of neurons.     

Evaluation of radioiodinated 5-iodo-3-(2(S)-azetidinylmethoxy)pyridine as a ligand for SPECT investigations of brain nicotinic acetylcholine receptors

5-Iodo-3-(2(S)-azetidinylmethoxy)pyridine (5IA), an A-85380 analog iodinated at the 5-position of the pyridine ring, was evaluated as a radiopharmaceutical for investigating brain nicotinic acethylcholine receptors (nAChRs) by single photon emission computed tomography (SPECT). [123/125I]5IA was synthesized by the iododestannylation reaction under no-carrier-added conditions and purified by high-performance liquid chromatography (HPLC) with high radiochemical yield (50%), high radiochemical purity (> 98%), and high specific radioactivity (> 55 GBq/micromol). The binding affinity of 5IA for brain nAChRs was measured in terms of displacement of [3H]cytisine and [125I]5IA from binding sites in rat cortical membranes. The binding data revealed that the affinity of 5IA was the same as that of A-85380 and more than seven fold higher than that of (-)-nicotine, and that 5IA bound selectively to the alpha4beta2 nAChR subtype. Biodistribution studies in rats indicated that the brain uptake of [125I]51A was rapid and profound. Regional cerebral distribution studies in rats demonstrated that the accumulation of [125I]5IA was consistent with the density of high affinity nAChRs with highest uptake observed in the nAChR-rich thalamus, moderate uptake in the cortex and lowest uptake in the cerebellum. Administration of the nAChR agonists (-)-cytisine and (-)-nicotine reduced the uptake of [125I]5IA in all regions studied with most pronounced reduction in the thalamus, and resulted in similar levels of radioactivity throughout the brain. [125I]5IA binding sites were shown to be saturable with unlabeled 5IA. Behavioral studies in mice demonstrated that 5IA did not show signs of behavioral toxicity. Furthermore, SPECT studies with [123I]5IA in the common marmoset demonstrated appropriate brain uptake and regional localization for a high-affinity nAChR imaging radiopharmaceutical. These results suggested that [123I]5IA is a promising radiopharmaceutical for SPECT studies of central nAChRs in human subjects.     

Chronic graft-versus-host autoimmune disease in Fc receptor gamma chain-deficient mice results in lipoprotein glomerulopathy

Lipoprotein glomerulopathy (LPG) is a unique renal disease characterized by intraglomerular lipoprotein thrombi associated with severe proteinuria and frequent progression to renal failure. The histologic hallmark of LPG is the presence of laminated thrombi, consisting of lipid droplet, within the lumina of dilated glomerular capillaries. The findings of thrombi consisting of lipoproteins raised the possibilities that LPG might be related to a primary abnormality in lipid metabolism. However, the precise pathogenic basis of LPG remains unresolved. It was herein found that chronic graft-versus-host disease (GVHD) induced by the transfer of Ia-incompatible spleen cells from B6.C-H2(bm12) into coisogenic C57BL/6 mice with deficiency of Fc receptor gamma chain (FcRgamma) resulted in glomerulopathy that resembled LPG. The uptake of acetylated LDL was partially decreased in peritoneal macrophages isolated from FcRgamma-deficient mice compared with wild-type mice, suggesting that partial impairment of modified LDL uptake might contribute to the development of LPG associated with chronic GVHD in FcRgamma-deficient mice. LPG has been suggested to be a disorder of primary abnormality in lipid metabolism; these findings would therefore provide novel insight into the disease process.     

Relationship between sperm mitochondrial membrane potential,sperm motility,and fertility potential

AIM:To analyze the relationship between sperm mitochondrial membrane potential and sperm motility parameters by means of a computer-assisted sperm analyzer (CASA) and in-vitro fertilization rate(%FR). METHODS: Semen samples were obtained from 26 men undergoing in vitro fertilization-embryo transfer (IVF-ET). Informed consent was obtained from all men prior to the study. Samples were prepared using wash and swim-up method in HEPES-HTF medium. The sperm motility (%MOT), progressive motility (%PMOT), average path velocity (VAP) microm/s), straight line velocity (VSL) (micro m/s), curvilinear velocity (VCL) (microm/s) and %hyperactivated sperm (%HA), and the %FR were assessed. The samples were incubated in the presence of 2.0 mciromol/L of 5,5',6,6'-tetra-chloro-1,1',3,3'-tetraethylbenzimidazolyl-carbocyanine iodide (JC-1) for 30 min at 37 degrees C in air and washed in PBS before flow cytometry (FACSCalibur: Becton Dickinson) analysis. The mitochondrial probe JC-1 was used to identify the mitochondrial membrane potential. The sperm was divided into three populations according to the fluorescence pattern as follows: the high mitochondrial membrane potential group (n=8), the moderate group (n=5), and the low group (n=13). Statistical analysis was performed using unpaired t-test. RESULTS:Significant differences were found between the high and the low groups in %MOT (91.1+/-8.5 vs 63.0+/-32.7, mean+/-SD), VAP (73.0+/-14.2 vs 52.1+/-12.5), VCL (127.0+/-28.1 vs 87.0+/-22.6), %HA (27.3+/-23.6 vs 7.2+/-9.0) and %FR [73.2 (48/56) vs 59.0 (69/117)]. No significant differences were found in other CASA parameters. CONCLUSION: When the sperm mitochondrial membrane potential increases, sperm motility parameters and fertility potential will also increase. The JC-1 dye method is useful to predict sperm fertility potential.     

Correlation between major histocompatibility complex class I molecules and CD8+ T lymphocytes in prostate,and quantification of CD8 and interferon-gamma mRNA in prostate tissue specimens

OBJECTIVE: To investigate the immunology of host-tumour interaction, critical for the development of immunotherapy against cancers, by assessing the major histocompatibility complex (MHC) class I expression in both benign and malignant prostate disease, and the relationship between their expression and degree of tumour-infiltrating lymphocytes. MATERIALS AND METHODS: Direct serial analysis of gene expression in tumours is an extremely sensitive and powerful tool for monitoring immunological changes in the immunotherapy of solid tumours. Most previous monitoring protocols rely mainly on the analysis of patient's peripheral blood but in the present study the direct molecular analysis of small tissue samples was used, and its accuracy compared with that of conventional immunohistochemical analysis. Twenty-four formalin-fixed, paraffin-embedded prostate samples (11 benign and 13 carcinoma) were used for the immunohistochemical analysis of CD8+ T lymphocytes and MHC class I expression. CD8+ T lymphocytes were counted using an ocular grid and MHC class I measured using digital image-analysis software. Twenty-seven frozen prostate tissue samples (12 benign and 15 carcinoma) were used for direct gene measurements of CD8 and interferon-gamma using a quantitative real-time polymerase chain reaction. RESULTS: There were significantly fewer CD8+ T lymphocytes in prostate carcinoma nests than in benign prostate. There was a significant correlation between the number of CD8+ T lymphocytes and MHC class I expression in the prostate. There was a strong correlation between the immunohistochemical estimates of CD8+ T lymphocytes and CD8 gene by polymerase chain reaction, but no significant difference between benign prostate and prostate carcinoma tissue in gene measurements. CONCLUSION: Down-regulation of MHC class I expression by prostate cancer cells is associated with fewer CD8+ T lymphocytes and hence might be important in cancer growth. In addition, the measurement of gene expression in small tissue samples might be useful for monitoring the efficacy of treatment throughout cancer therapy.     

Cost performance and efficacy of off-pump coronary artery bypass grafting

Off-pump coronary artery bypass grafting (Off-Pump CABG) may provide an alternative form of surgical revascularization by avoiding the unwanted complications of cardiopulmonary bypass, particularly in high-risk patients. To clarify the efficacy and cost performance of Off-Pump CABG, we studied the postoperative course of Off-Pump CABG and compared it to On-pump coronary artery bypass grafting (On-Pump CABG). From Aug. 1998 to Feb. 2002, twenty-eight patients who had preoperative complications such as cerebral vascular disease (11), chronic renal failure (4), atheromatous aorta (4), one lung (1), severely impaired left ventricular function (6), re-do CABG (1), and cancer (1) underwent Off-Pump CABG. Another thirty-six patients who underwent On-Pump CABG served as a control. The Off-Pump CABG patients were almost the same age as the On-Pump CABG patients (68 +/- 8 vs 64 +/- 8 years, ns). The Number of grafts was similar in both groups (2.6 +/- 1.0 vs 2.9 +/- 1.0, ns). Peak CK, peak CKMB, peak LDH, and peak GOT release were significantly lower in the Off-Pump CABG group compared with the On-Pump CABG group. Graft patency rates were similar in both groups (98% in Off-Pump CABG vs 98% in On-Pump CABG). The total cost for surgery and patient care was significantly lower (p < 0.0001) in the Off-Pump CABG group (dollar 21000 +/- 7000) compared with the On-Pump CABG group (dollar 33000 +/- 4200). Off-Pump CABG is less invasive to the myocardium, is less expensive, and has a similar efficacy in comparison with On-Pump CABG.     

Discovery of novel [Arg49]phospholipase A2 isozymes from Protobothrops elegans venom and regional evolution of Crotalinae snake venom phospholipase A2 isozymes in the southwestern islands of Japan and Taiwan.

Protobothrops (formerly Trimeresurus) elegans, a Crotalinae snake, inhabits Ishigaki and Iriomote islands of the Sakishima Islands of Japan which are located between Okinawa island of Japan and Taiwan. Two phospholipase A(2) (PLA(2)) isozymes were purified to homogeneity from P. elegans venom and sequenced. This led to a discovery of novel PLA(2) isozymes with Arg at position 49, that is, [Arg(49)]PLA(2) forms, named PeBP(R)-I and PeBP(R)-II. They are polymorphic at position 3, Val for PeBP(R)-I and Ile for PeBP(R)-II. The cDNAs encoding PeBP(R)-I and PeBP(R)-II were cloned. The cDNA encoding an [Asp(49)]PLA(2) named PePLA(2) was also obtained. In contrast to PLA(2) isozymes from Protobothrops genus with 122 amino acid residues, PeBP(R)-I and PeBP(R)-II are composed of 121 amino acid residues due to lack of Pro at position 90. They exhibited necrotic and edema-inducing activities but no hemorrhagic activity was detected. A phylogenetic tree constructed for venom PLA(2) isozymes of Protobothrops genus and of related genera in the southwestern islands of Japan and Taiwan revealed that PeBP(R)-I and PeBP(R)-II of P. elegans are evolutionarily much closer to PmK49PLA(2), a [Lys(49)]PLA(2), from P. mucrosquamatus (Taiwan) than BPI and BPII, both [Lys(49)]PLA(2) forms, from P. flavoviridis (Amami-Oshima and Tokunoshima islands of Japan). Such evolutionary relationships are also seen in neutral [Asp(49)]PLA(2) isozymes from the three Protobothrops species. Thus, P. elegans is the species much closer to P. mucrosquamatus than P. flavoviridis. Their evolutionary distances seem to be well related to geological history of the islands where they have lived. In addition, it was clearly noted that Ovophis okinavensis (Amami-Oshima), which had formerly belonged to the Trimeresurus genus, and Trimeresurus stejnegeri (Taiwan) are the species fairly distant from Protobothrops genus.     

Feeding function, blink reflex and MRI in the severely handicapped

Blink reflexes were studied in 41 patients with severe handicaps, and were correlated with feeding problems and other lower brainstem symptoms such as drooling, an absent gag reflex and stridor. Ventrodorsal diameters of the pons and medulla oblongata on sagittal MRI were also studied in 29 of the cases. The patients were divided into three groups: tube feeding (25 cases), oral feeding (13 cases) and mixed feeding (3 cases). In the tube feeding group, all but three cases showed a prolonged or absent R1 component, and all cases showed prolonged or absent R2 and R2' components. These abnormalities were significantly more frequent in the tube than in the oral feeding group. The patients with drooling, stridor or an absent gag reflex more frequently showed prolonged or absent components than the patients without these symptoms. The brainstem size on MRI was not different between the tube and oral feeding group. These results suggest that the blink reflex, particularly its late components, is a useful indicator for evaluating feeding function and other lower brainstem functions.