Fatigue strength of Ce-TZP/Al2O3 nanocomposite with different surfaces.

Ce-TZP/Al(2)O(3) nanocomposite (NANOZR) has not only higher strength, but also higher fracture toughness than conventional Y-TZP, indicating its potential for use in dental implants. Surface treatment to obtain osseointegration, however, may alter its surface topography, thus affecting the cyclic fatigue strength that plays such an important role in the durability of this material. The aim of this study was to evaluate the influence of surface treatment on cyclic fatigue strength in NANOZR as compared with grit-blasted and acid-etched Y-TZP (125BE Y-TZP). Bi-axial flexure strength was measured in both static and cyclic fatigue tests, as recommended by ISO 6872. The cyclic fatigue test was performed by the staircase method in distilled water at 37°C, with a load of 10(6) cycles and 10 Hz. Bi-axial flexure strength of NANOZR was 1111-1237 MPa and 667-881 MPa in the static and cyclic fatigue tests, respectively. The bi-axial flexure strength of NANOZR under all conditions was greater than that of 125BE Y-TZP in the static and cyclic fatigue tests. The cyclic fatigue strength of NANOZR was more than twice that of Y-TZP as specified in ISO 13356 for surgical implants (320 MPa), indicating the promise of this material for use in dental implants.

Effect of partial replacement of forage neutral detergent fiber with by-product neutral detergent fiber in close-up diets on periparturient performance of dairy cows.

The objective of this study was to determine the effect of partial replacement of forage neutral detergent fiber (NDF) with by-product NDF in close-up diets of dairy cattle on periparturient metabolism and performance. Holstein cows (n = 45) and heifers (n = 19) were fed corn silage-based diets containing 1) 30% oat hay, or 2) 15% oat hay and 15% beet pulp from d -21 relative to expected parturition until parturition. After parturition, all animals received the same lactation diet. Animals were group-fed from d -21 to -10 relative to expected parturition and fed individually from d -10 until 14 d in milk. Animals were required to have at least 5 d of prepartum dry matter intake (DMI) data to remain on the study. Data were analyzed as a randomized design and subjected to ANOVA using the MIXED procedure of SAS. Close-up diet did not affect DMI, total tract nutrient digestibility, energy balance, or serum content of nonesterified fatty acids and beta-hydroxybutyrate during the last 5 d prepartum. Prepartum body weight and body condition score were similar between treatments. There was no carryover effect of close-up diet on DMI, energy balance, milk yield, body weight, body condition score, or serum content of nonesterified fatty acids and beta-hydroxybutyrate during the first 14 d in milk. In summary, partial replacement of forage NDF (oat hay) with by-product NDF (beet pulp) did not affect periparturient metabolism or performance.

Case report: pulmonary embolism from thrombosis in a duplicated inferior vena cava developing after an electrophysiologic procedure.

Duplicated inferior cava (IVC) is an anomaly we rarely encounter during electrophysiologic procedures. We report a case with duplicated IVC who developed thrombosis of the left IVC following an electrophysiologic procedure, which resulted in an asymptomatic pulmonary embolism. It is speculated that several catheters placed in the torturous route through the left IVC caused either endothelial damage to the vessel wall, or hemostasis in the relatively narrow portion of the vessel, resulting in thrombus formation. Since the prevalence and characteristics of thrombo-embolic complications during electrophysiologic procedures in patients with a duplicated IVC remain unknown, we believe this case should be reported.

Changes in the lifestyle of Mongolian pastoralists in China in connection with urbanization.

The objective of this study was to elucidate changes in the health-related lifestyle of Mongolian pastoralists in China in connection with their urbanization. A total of 592 people participated in a survey that included a medical examination and an interview questionnaire. Files of 72 pastoral Mongolians, 78 urban Mongolians, 380 urban Han/Man and 21 urban Hui were used for this analysis. Urban Mongolians consumed meat and milk products less frequently than did pastoral populations (p < 0.001), and consumed fish and vegetables more frequently than did pastoral populations (p < 0.001). Urban Mongolian consumed mutton, beef, rengyo fish, milk, milk tea, curd, butter, yogurt, and sheep milk less frequently (p < 0.05) and pork, sword fish, and dried milk more frequently (p < 0.05) than pastoral Mongolian. Male pastoral Mongolians were more likely to drink and smoke than were urban Mongolians (p < 0.01), urban Han/Man (p < 0.01), or urban Hui (p < 0.01). The lifestyles of pastoral Mongolians in Inner Mongolia, China have changed in connection with urbanization. Understanding of the traditional pastoral lifestyle and the urban-living acculturation process will contribute to maximizing the positive impacts of urbanization on people's health in Inner Mongolia.

Induction of mcl1/EAT, Bcl-2 related gene, by retinoic acid or heat shock in the human embryonal carcinoma cells, NCR-G3.

NCR-G3 cells were established from a testicular embryonal carcinoma and were differentiated into multi-lineages including trophectoderm cells by exposure to retinoic acid. The differentiated cells began to produce human chorionic gonadotropin (hCG), a trophectoderm-specific hormone, which was regulated at the mRNA level. As we assumed that genes responsible for differentiation were differentially expressed at the early stage of retinoic acid-induced differentiation, we prepared a cDNA library from retinoic acid-treated NCR-G3 cells. This cDNA library was then screened for genes whose expression was induced during the differentiation of these cells. From about 5 x 10(4) clones screened, three independent sequences were isolated. Sequencing analysis revealed that clone 1002 codes for mcl1/EAT, which has a Bcl-2 homology domain. The expression of mcl1/EAT, the Bcl-2 related gene, was increased at an early stage of the retinoic acid-induced differentiation and preceded the up-regulation of cytokeratin and hCG genes after ratinoic acid treatment. Furthermore, mcl1/EAT was also up-regulated by heat shock, which has recently been shown to induce the cells to differentiate.

Genotypes of sarco(endo)plasmic reticulum Ca(2+)-dependent ATPase II gene in substrains of spontaneously hypertensive rats.

OBJECTIVE: To search for a genetic marker of the sarco(endo)plasmic reticulum Ca(2+)-dependent ATPase (SERCA) II gene in spontaneously hypertensive rats (SHRs) and to investigate differences in blood pressure and intracellular Ca2+ among some substrains of SHRs and Wistar-Kyoto (WKY) rats related to their SERCA II genotypes. DESIGN AND METHODS: The coding region of the SERCA II gene was sequenced in SHRs. Blood pressure and intracellular Ca2+ concentration ([Ca2+]i) in platelets were measured in substrains of SHRs and WKY rats with different SERCA II genotypes. RESULTS: A point mutation that provided restriction fragment length polymorphisms (RFLPs) by HindIII or Saul was found in the SERCA II gene. The polymerase chain reaction (PCR) products were digested by HindIII in SHR substrains and WKY-Kyoto rats, whereas they were digested by Saul in normotensive strains and SHR-Toho. Among SHR-Kyoto, SHR-Toho, WKY-Kyoto and WKY-Charles River, the substrains with the HindIII-digested SERCA II genotype showed slightly but significantly higher systolic blood pressure and augmented agonist-stimulated [Ca2+]i than those with the Saul-digested genotype. CONCLUSIONS: RFLPs were found in the SERCA II gene. In the substrain analysis of SHRs and WKY rats, higher blood pressure and increased [Ca2+]i were associated with the SERCA II genotype digested by HindIII. The SERCA II gene locus has the potential to contribute to the development of hypertension and abnormal intracellular Ca2+ metabolism in SHRs. These RFLPs in the SERCA II gene should be a useful genetic marker.

Expression of human platelet-activating factor receptor gene in EoL-1 cells following butyrate-induced differentiation.

Platelet-activating factor (PAF) is a potent lipid mediator of allergic inflammation through its interaction with eosinophils. Expression of the PAF receptor is modulated by many agents, including those responsible for cell differentiation. We report here that differentiation of a human eosinophilic leukaemia cell line, EoL-1, by sodium n-butyrate is associated with induction of PAF receptor gene expression, as indicated by: PAF receptor mRNA accumulation; increases in the binding of [3H]WEB 2086, a PAF antagonist; analysis of cell-surface expression of PAF receptor protein using a monoclonal anti-(PAF receptor) antibody; and augmentation of PAF-induced increase in the intracellular concentration of calcium. Using cDNA cloning, the receptor expressed in EoL-1 cells was identified as 'Transcript 1', one of two transcripts which was previously reported from human genomic analysis (Mutoh, Bito, Minami, Nakamura, Honda, Izumi, Nakata, Kurachi, Terano and Shimizu (1993) FEBS Lett. 322, 129-134). The PAF-induced calcium response and phosphoinositide turnover were decreased by pertussis toxin (PTX) treatment, suggesting that these signals are coupled largely with PTX-sensitive G-protein(s) in EoL-1 cells. These systems may provide a useful experimental model with which to investigate the relationship between eosinophilic differentiation and PAF receptor induction, and the role of eosinophils in allergic responses.

Severe hyponatremia and hyperkalemia induced by trimethoprim-sulfamethoxazole in patients with Pneumocystis carinii pneumonia.

An antimicrobial agent trimethoprim-sulfamethoxazole (Tmp-Smx) does not usually cause electrolyte disturbances at regular doses, and few cases of Tmp-Smx-induced electrolyte imbalance have been reported in the English-language literature to date. Recently, however, we treated two patients with Pneumocystis carinii pneumonia who developed severe hyponatremia and hyperkalemia on administration of high-dose Tmp-Smx. These electrolyte disturbances were attributable to the direct effect of Tmp-Smx on the renal distal tubules, were reversible, and corrected by infusion of a sodium-enriched and potassium-free liquid. Therefore, it is suggested that even after electrolyte disturbances have occurred, high-dose Tmp-Smx therapy may be continued for severe infectious diseases under appropriate electrolyte correction.

Intracerebral vascular occlusion in familial erythrophagocytic lymphohistiocytosis: a case report of two siblings.

Neuropathological findings in two siblings with familial erythrophagocytic lymphohistiocytosis (FEL) are reported. Case 1 showed the typical neuropathological findings of FEL with lymphohistiocytic infiltration of the leptomeninges and perivascular spaces. A characteristic erythrophagocytosis was detected in inguinal lymph nodes, lung and bone marrow. Case 2 revealed calcification and necrotic lesions in the brain. In the necrotic areas, parenchymal calcification, vascular medial calcification, and occlusion of many vessels due to subendothelial fibrosis were detected. The areas of necrosis correlated with the distribution of occluded vessels. These changes were most prominent in putamen, internal capsule, thalamus and dentate nucleus. Hypercytokinemia is suspected to be the underlying mechanism for the clinical and laboratory findings in patients with FEL, although the relationship to the vascular pathology is unclear.

Functional coupling of SSTR4, a major hippocampal somatostatin receptor, to adenylate cyclase inhibition, arachidonate release and activation of the mitogen-activated protein kinase cascade.

Somatostatin has a modulatory role in regulating the membrane conductance in hippocampal neurons. To examine the signal transducing molecules involved in this process, we isolated the cDNA encoding the dominant rat hippocampal somatostatin receptor, SSTR4. Distribution of SSTR4 in the adult central nervous system was restricted to the hippocampus, cerebral cortex, striatum, hypothalamus, and thalamus, as determined by Northern blot analysis and in situ hybridization. In SSTR4-expressing Chinese hamster ovary cells, SSTR4 was functionally coupled not only to inhibition of adenylate cyclase, but also to activation of both arachidonate release and mitogen-activated protein (MAP) kinase cascade, with similar ED50 values. All of these pathways, including both MAP kinase kinase and MAP kinase activation, were completely blocked by pretreatment with pertussis toxin. On the other hand, neither inositol 1,4,5-trisphosphate synthesis nor intracellular Ca2+ mobilization was induced upon SSTR4 stimulation. These data indicate that the hippocampal functions of somatostatin might be mediated through diverse but selective second messenger systems activated via SSTR4 and reveal an unsuspected coupling of a neuronal SSTR subtype to a mitogenic signaling pathway. SSTR4, in addition, provides a useful system to study the Ca(2+)-independent, Gi-dependent (pertussis toxin-sensitive) pathway of MAP kinase activation.

cDNA sequences encoding human fructose 1,6-bisphosphatase from monocytes, liver and kidney: application of monocytes to molecular analysis of human fructose 1,6-bisphosphatase deficiency.

Fructose 1,6-bisphosphatase deficiency is an autosomal recessive inherited disorder of gluconeogenesis. We could isolate cDNAs encoding human fructose 1,6-bisphosphatase from normal monocytes, liver and kidney, but not from normal lymphocytes. The cDNAs contained an open reading frame coding for 338 amino acids, and their nucleotide sequences in monocytes and liver were identical. G644C645 nucleotides in this sequence were the same as those of cDNA from HL-60 cells, although our result differed from a previous report (M. El-Maghrabi et al. (1993) J. Biol. Chem. 268, 9466-9472) on an alteration to C644G645 nucleotides in human liver cDNA resulting in a change of Gly-214 to Ala-214 in the enzyme. The Gly-214 (GGC) residue was therefore conserved in the enzymes hitherto isolated from humans and other animals. Analysis of monocytes in seven patients with fructose 1,6-bisphosphatase deficiency showed a DNA fragment with apparent normal size in two sisters but no detectable DNA fragment in the other five patients. Monocytes were thus useful as an alternative source for mRNA from human liver for the molecular analysis of fructose 1,6-bisphosphatase deficiency.

[A case of clinical Reye syndrome with symmetrical abnormal signal areas in the pons and thalami by MRI].

We report a two-year-old boy with clinical Reye syndrome. Brain CT disclosed symmetrical low-density areas in the pons and thalami, a part of which was recognized as being of high-intensity on both T1 and T2 weighted MRI. These lesions were suspected of being caused by vascular involvement, since the methemoglobin induced by bleeding may have contributed to the high-intensity regions. The lesions gradually disappeared within four months after the onset, and clinical symptoms also improved markedly without serious neurologic impairment. This case was characterized by the marked improvement in neurological and radiological findings in spite of the serious neurological involvement at onset.

[Effect of coix seed on the changes in peripheral lymphocyte subsets].

Coix seed has been used in patients with verruca vulgaris and verruca planae juveniles, which have been considered to be induced by viral infection. Moreover, coixenolide, component in the seeds of coix, was reported to show anti-tumor activity. Possibly coix seed may have some influence on the cytotoxic activity of peripheral lymphocytes but there has been no data on this. Then we investigated the changes in number of cytotoxic lymphoid cells in seven volunteers before, during (four weeks) and after taking six coix seed tablets. Lymphocyte subsets were analyzed with monoclonal antibodies using a flow cytometer. The level of CD3+CD56+ (MHC-non restricted cytotoxic T cells) markedly increased at four weeks (before 1.9 +/- 0.5% vs four weeks 4.2 +/- 0.7%, p less than 0.01). The level of CD16+CD57- (the mature, most active natural killer cells) increased at three weeks (before 4.5 +/- 0.8% vs three weeks 5.2 +/- 0.8%, p less than 0.05). The level of CD3-CD56+ (natural killer cells) and the level of CD16+CD57+ (the variable active natural killer cells) decreased at one week and returned to normal level thereafter (before 13.7 +/- 2.1% vs one week 11.2 +/- 1.5%, p less than 0.05; before 8.8 +/- 1.5% vs one week 6.9 +/- 1.3%, p less than 0.05, respectively). These results indicate that coix seed modulate the peripheral blood lymphocyte subsets and may be effective to virus disease through the enhancement of cytotoxic activity.

Immunohistochemical study of temporal variations in cytochrome P-450 isozymes in rat testis and their modifications by the inductive effects of cadinenes.

Temporal variations in cytochrome P-450 isozymes of rat testis, PB-P-450 (forms of cytochrome P-450 strongly induced by phenobarbital) and MC-P-448 (forms of cytochrome P-450 strongly induced by 3-methylcholanthrene), were investigated immunohistochemically by the avidin-biotin-complex method using specific antibodies against PB-P-450 and MC-P-448 isozymes. Immunoreactivity to both PB-P-450 and MC-P-448 isozymes was observed in Leydig cells. The number of PB-P-450 positive Leydig cells was found to undergo significant time-of-day variation with a peak time of 0000 hours (light phase from 0800 to 2000 hours). Injection of cadinenes (300 mg/kg per day intraperitoneally at 48 and 96 h before sacrifice) induced PB-P-450 isozyme but did not induce MC-P-448 isozyme. The induction of PB-P-450 isozyme by cadinenes was time dependent, and the early dark phase (2000 and 0000 hours) was most sensitive. These results suggest that temporal variation of cytochrome P-450 isozymes is one of the important physiological variations in detoxification and activation of various xenobiotics and chemicals in the testis.

The effect of hyperbaric oxygen on cerebral hemoglobin oxygenation and dissociation rate of carboxyhemoglobin in anesthetized rats: spectroscopic approach.

By measuring near-infrared transmittance spectra, we examined the effect of HBO on cerebral Hb oxygenation in normal and ischemic brain in the anesthetized rat. The oxygenation state of Hb was around 80% in the rat brain under 1 ATA air breathing. HBO did not induce further cerebral Hb oxygenation above 2 ATA in control animals but improved tissue oxygenation in the ischemic brains. The oxidation-reduction state of cyt. aa3 in the normal brain was not affected by HBO. In the ischemic brain, however, HBO prevented ischemia-induced reduction of cyt. aa3. Non-invasive optical monitoring of COHb with visible reflectance spectrophotometry was also examined. HBO markedly accelerated dissociation of COHb. Tight correlation was found between the optical signal and COHb content determined from blood samples. These results demonstrated the usefulness of optical monitoring in vivo under hyperbaric conditions.

Trickle water and feeding system in plant culture and light-dark cycle effects on plant growth.

Rockwool, as an inert medium covered or bagged with polyethylene film, can be effectively used for plant culture in space station. The most important machine is the pump adjusting the dripping rate in the feeding system. Hydro-aeroponics may be adaptable to a space laboratory. The shortening of the light-dark cycles inhibits plant growth and induces an abnormal morphogenesis. A photoperiod of 12-hr-dark may be needed for plant growth.

The effects of various chemicals on the development of hyperplastic liver nodules in hepatectomized rats treated with N-nitrosodiethylamine or N-2-fluorenylacetamide.

The effects of various hepatocarcinogenic, non-hepatocarcinogenic and non-carcinogenic chemicals on the induction of hyperplastic liver nodules by N-nitrosodiethylamine (DEN) or N-2-fluorenylacetamide (2-FAA) as an initiator were studied in male Fischer 344 rats. Rats were injected intraperitoneally with 200 mg of DEN/kg body weight or were fed on basal diet containing 200 ppm of 2-FAA for 2 weeks, and then given various test chemicals starting from week 3. They were also partially hepatectomized in week 3. All animals were killed at the end of week 8 and examined histologically. For quantitative analysis, hyperplastic nodules in the liver were measured with a color video image processor, VIP-21C. The effect of various chemicals in rats treated with DEN or with 2-FAA were compared. The production of hyperplastic liver nodules was greatest in rats treated with strong hepatocarcinogens, and less in rats treated with weak hepatocarcinogens. Very few hyperplastic nodules were produced after treatment with non-hepatocarcinogens or noncarcinogens. Hyperplastic nodules were formed in rats treated with phenobarbital, which is a hepatopromoter. Saccharin, which is a urinary bladder promoter, did not enhance the production of hyperplastic nodules in the liver. These results indicate that many hepatocarcinogens enhance liver carcinogenesis. The classification of chemicals as liver carcinogens is discussed on the basis of the results.

Crystal structure analysis of a complete turn of B-DNA.

DNA is probably the most discussed and least observed of all biological macromolecules. Although its role in biology is a central one, with many examples such as operators and restriction sites where specific base sequences have control functions or interact with specific enzymes, the structures that DNA can adopt have been based until now only on sequence-averaged fibre diffraction patterns. Recent improvements in triester synthesis methods have made possible the preparation of sufficient homogeneous DNA of predetermined sequence for crystallization and X-ray structure analysis. We report here the first single-crystal structure analysis of more than a complete turn of right-handed B-DNA, with the self-complementary dodecamer sequence d(CpGpCpGPApApTpTpCpGpCpG) or CGCGAATTCGCG.

Effect of hyperbaric oxygen on cyanide intoxication: in situ changes in intracellular oxidation reduction.

To evaluate the efficacy of hyperbaric oxygen on cyanide intoxication, changes in the intracellular oxidation-reduction state of the renal cortex were observed in situ in 16 New Zealand white rabbits by detecting the reduced pyridine nucleotide fluorescence that represents the degree of cyanide blockade of the respiratory chain. The data indicated that 100% oxygen at 2 ATA exerted both prophylactic and therapeutic antagonistic effects on the cyanide poisoning. Administration of hyperbaric oxygen could constitute a significant treatment if proper chemical treatment is carried out concomitantly.

Mutagenic activity of selenium compounds.

The mutagenicities of selenate (SeO2/4-) and selenite (SeO2/3-) were determined by two bacterial assay systems: Kada's rec-assay and Ames's Salmonella test. In both assays, these compounds were found to be weak mutagens. In the Salmonella test, selenate (0.05 revertants/nmole) and selenite (0.2 revertants/nmole) gave rise to base-pair substitution.