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Thigh cuffs are used by cosmonauts to limit fluid shift during space flight, but the appropriate level of cuff pressure and the duration of application to optimize their beneficial effects require further detailed investigations. In the present study, 10 days head-down tilt (HDT) bed rest was performed to assess the effects of thigh cuffs (40 mmHg, 10 h/day) on haemodynamic changes of the middle cerebral artery (MCA) and on orthostatic tolerance in six healthy male volunteers. Another six healthy male volunteers without thigh cuffs served as the control group. Haemodynamic parameters of the MCA were measured using transcranial Doppler. Orthostatic tolerance was assessed before and after HDT. After HDT, the mean upright time in the control and thigh cuff groups was 14.0 +/- 4.1 and 19.2 +/- 0.7 min, respectively. Compared with values before HDT, the percentage increase in heart rate from baseline in the upright position after HDT was significantly higher in the control group and the percentage change from baseline of mean diastolic arterial blood decreased more after HDT in this group. In the control group, systolic blood velocity (Vs) and mean blood velocity (Vm) of the right MCA decreased significantly during HDT. In the thigh cuffs group, the Vs of the right MCA decreased significantly on Days 3 and 7 of HDT and the Vm of the right MCA decreased significantly on Day 7 of HDT. The results indicate that daily use of thigh cuffs during 10 days of HDT does not completely prevent the decrease in haemodynamics of the right MCA, but is effective in preventing orthostatic intolerance.

Objective: To study the effectiveness and feasibility of remote sensing technology in the rare species of wild plant resources., Method: The mechanism and characteristics of Paeonia sinjiangensis were analyzed to find the possibility of extracting from TM imagery. An expert system has been used with Landsat Thematic Mapper data to derive P. sinjiangensis. Then logical decision rules were used with the various datasets to assign values., Result: The land for P. sinjiangensis possible growth were mapped and accuracy tested was approving., Conclusion: The results suggest that the remote sensing expert interpretation system using satellite imagery and ancillary data will be feasible for research of rare wild medicinal plants distribution.

Cordyceps sinensis , one of the best known traditional Chinese medicines and health foods, has been highly valued for the treatment of a wide range of diseases and reported to have antioxidant properties. In the present study, the antioxidant activities of hot-water extracts from natural and cultured mycelia of C. sinensis were investigated and evaluated using six in vitro assays, including inhibition of linoleic acid peroxidation; scavenging abilities on DPPH•, hydroxyl and superoxide anion radicals; the reducing power and the chelating ability on ferrous ions. Among these assays, the extracts showed the best effect on the inhibition of linoleic peroxidation with the lowest IC50 values and with an inhibition rate over 90% at concentration of 0.8-1.6 mg/ml, more stable than that of α -tocopherol, a recognised natural antioxidant. The scavenging activities on superoxide anion and hydroxyl radicals of the two extracts were slightly lower than that of butylated hydroxytoluene. DPPH• scavenging activities of both extracts reached over 80% inhibition at 4-8 mg/ml. Both extracts showed moderate reducing power and ferrous ion chelating activity. The IC50 value of the extract from cultured mycelia in all the tests, except for linoleic acid peroxidation, was significantly lower than that of natural mycelia. There was no evident correlation between the antioxidant activity and the content of protein, polysaccharides and mannitol of extracts from C. sinensis ; the antioxidant activity may be due to a combined effect of these or some other compounds. These results suggested that both the extracts from cultured and natural mycelia have direct and potent antioxidant activities and that the cultured mycelia of the fungus could be used for the antioxidant activity to reduce the human demands on the natural resources of the fungus, an endangered species., (Copyright © 2007 Swiss Society of Food Science and Technology. Published by Elsevier Ltd. All rights reserved.)

Objective: The mechanisms of hypoxic-ischemic brain damage (HIBD) are still largely unknown. Elevation of intracellular calcium concentration and subsequent calcium-dependent proteases activation such as calpains seem to play an important role in the process of neuronal death. Calpain inhibitors showed neuroprotective effects in adult rat cerebral ischemia models. This study aimed to investigate the protective effect and associated mechanisms of calpain inhibitor-3 (MDL28170) on HIBD of neonatal rats., Methods: Seven-day old Sprague-Dawley rats were randomly divided into three groups: the control group (n = 18), HIBD group (n = 48) and calpain inhibitor-3 treated group (MDL group, n = 48). The mice in the latter two groups were subjected to hypoxia-ischemia (HI) insult. The puppies in MDL group were intraperitoneally injected with MDL28170 (25 mg/kg) at 0, 2 and 4 h after HI, while those in the other two groups were intraperitoneally injected with normal saline instead. All the pupies were sacrificed at 6 h, 24 h and 72 h after HI. Quantitative real-time fluorescent polymerase chain reaction was employed to detect micro-calpain gene expression, immunoblotting technique was used to measure mu-calpain and caspase-3 protein activation, apoptosis of ipsilateral cortex was detected by terminal deoxynucleotidyl transferase mediated d-UTP nick end labeling staining (TUNEL). CA1 neuronal loss was counted 24 h after HI by light microscopy., Results: After HI mu-calpain mRNA began to increase at 6 h and reached peak at 24 h compared to the control (1.805 and 4.83 vs. 1, P < 0.05); mu-calpain was activated through autolysis, the ratio of its activated fragment (76 000) vs. whole fragment (80 000) was significantly higher at 6 h (0.547 +/- 0.095) compared to the control (0.095 +/- 0.016, P < 0.05), it reached peak at 24 h (0.921 +/- 0.058, P < 0.01) and was still at a high level at 72 h (0.708 +/- 0.025, P < 0.05). Expression of activated caspase-3 protein reached peak at 24 h (3.78 +/- 0.30, P < 0.01), decreased to the same level as the control (1.56 +/- 0.07) at 72 h (1.82 +/- 0.11, P > 0.05). Apoptotic cells in the cortex ipsilateral to HI insult increased after HIBD, reached peak at 24 h (135.46 +/- 17.52/visual field) and was still markedly higher at 72 h (79.32 +/- 17.79/visual field) compared with the control (5.33 +/- 1.53/visual field, P < 0.01). At 24 h after HI CA1 neuronal loss (30.0 +/- 6.2/oil immersion lens field) in the HIBD group was significantly higher than that of the control (2.4 +/- 0.3/oil immersion lens field, P < 0.01). However, in the MDL group the expressions of mu-calpain and caspase-3 proteins were diminished, TUNEL positive cells at 6 h and 24 h were decreased and CA1 neuronal loss (18.2 +/- 2.4/oil immersion lens field, P < 0.05) was alleviated. The amount of micro-calpain mRNA was decreased in the MDL group, but there was no significant difference compared with the HIBD group., Conclusion: mu-calpain gene and protein expressions increased after HI, which may contribute to the pathogenensis of HIBD. Calpain inhibitor-3 may intervene neural necrosis and apoptosis by diminishing expressions of mu-calpain and caspase-3 to play a protective role after HI insult of neonatal brain.

A molecular method based on PCR-restriction fragment length polymorphism (RFLP) analysis of internal transcribed spacer (ITS) ribosomal DNA sequences was designed to rapidly identify fungal species, with members of the genus Pleurotus as an example. Based on the results of phylogenetic analysis of ITS sequences from Pleurotus, a PCR-RFLP endonuclease autoscreening (PRE Auto) program was developed to screen restriction endonucleases for discriminating multiple sequences from different species. The PRE Auto program analyzes the endonuclease recognition sites and calculates the sizes of the fragments in the sequences that are imported into the program in groups according to species recognition. Every restriction endonuclease is scored through the calculation of the average coefficient for the sequence groups and the average coefficient for the sequences within a group, and then virtual electrophoresis maps for the selected restriction enzymes, based on the results of the scoring system, are displayed for the rapid determination of the candidate endonucleases. A total of 85 haplotypes representing 151 ITS sequences were used for the analysis, and 2,992 restriction endonucleases were screened to find the candidates for the identification of species. This method was verified by an experiment with 28 samples representing 12 species of Pleurotus. The results of the digestion by the restriction enzymes showed the same patterns of DNA fragments anticipated by the PRE Auto program, apart from those for four misidentified samples. ITS sequences from 14 samples (of which nine sequences were obtained in this study), including four originally misidentified samples, confirmed the species identities revealed by the PCR-RFLP analysis. The method developed here can be used for the identification of species of other living microorganisms.

Objective: To observe the expressions of mRNA and protein for the CCR2 in cerebral tissue with experimental hypoxic-ischemic brain damage (HIBD) to newborn rat., Methods: The HIBD model of SD rat was set up by ligating the right carotid artery and exposing the animals to 8% oxygen for 2.5 h. The dynamic change of CCR2 mRNA level was studied by using quantitative, real-time, fluorescence PCR assay (TaqMan), and the change of CCR2 protein was detected by SDS-PAGE assay., Results: The highest expression of CCR2 mRNA was showing at 24 h after HIBD, of which the level was significantly higher in hypoxic-ischemic (HI) cerebral hemisphere than in control (P < 0.05). The CCR2 mRNA level of 72 h after HIBD was still higher than that of control (P > 0.05) but had no difference on 7 d after HIBD when compared with control (P > 0.05). The increased expression of CCR2 protein was detected at 12 h after HIBD and peaked at 24 h after HIBD. The significant increase of CCR2 protein persisted in HI hemisphere up to 3 d after HIBD., Conclusion: The expressions of CCR2 mRNA and protein increase significantly in cerebral tissue of newborn rat with HIBD. The dynamic change of CCR2 expression is consistent with the process of HIBD, which suggests that CCR2 expression after HIBD may play an important role in the mechanism of brain damage.

Objective: To investigate the Nogo-A expression and its regeneration inhibition role in oligodendrocyte precursor cells (OLPs) after oxygen & glucose deprivation (OGD)., Methods: The OLPs were separated by the improved procedure of separation and purification through agitation and then cultured in chemically defined medium. The OGD model of OLPs was set up by using Na2S2O4 and Earle's fluid in the medium in vitro. Immunofluorescence assay was applied to identify the OLPs with its specific antibodies such as A2B5, O4 and O1. Western blot and immunofluorescence assay were used to analyze the expression of Nogo-A in OLPs at 10 min, 30 min and 60 min after OGD. The livability rate of cells in each group was detected by MTT., Results: The expression of Nogo-A was increased significantly compared with control at 10 min, 30 min and 60 min after OGD (P < 0.05). MTT result showed that the livability rate of OLPs with OGD was significantly lower than that of control (P < 0.05)., Conclusion: The expression of Nogo-A is increased while the OLPs livability is dropping down after OGD, which suggests that Nogo-A may play a role in OLPs damage and in the pathogenesis of restraining OLPs' regeneration.

Objective: White matter damage (WMD) in preterm infants is a well-recognized serious complication of prematurity. The collapse of cell skeleton of growth cone after hypoxia-ischemia (HI) is considered as the basic neuropathologic change of the long-term residuals of premature white matter damage. F-actin is the major component of cell skeleton and maintains the normal form of cells, its function and potential mechanism of WMD have not been reported. In this study, changes of F-actin and its influencing factor RhoA were investigated., Methods: Totally 184 Sprague-Dawley (SD) rats (age 2 days, body weight 6 to 8 grams) were randomly divided into 14 groups: 7 different time WMD groups (HI 12 h, 24 h, 48 h, 72 h, 7 d, 14 d, 28 d) and 7 corresponding control groups. The 2 day-old SD rats were subjected to ligation of right carotid artery (ischemia), and then they were put into a box full with 6% oxygen and 94% nitrogen for 4 hours (hypoxia). The light microscopy was used to observe the brain pathological changes and the electron microscopy was used to detect the brain ultrastructural changes after hypoxia and ischemia. Eighty SD rats were used for flurescent-immunohistochemical method to detect the distribution of F-actin in cell membrane and cytoplasm of both WMD groups and the control groups at 12 h, 24 h, 48 h, 72 h, 7 d after HI respectively. The distribution of F-actin was reflected by the percentage of non-integrity cells. Another 80 SD rats were used for real time RT-PCR to detect the expression of RhoAmRNA in the white matter tissue of both WMD groups (HI 12 h, 24 h, 48 h, 72 h, 7 d) and the control groups., Results: (1) Necrosis of lateral ventricle tissue was observed by 72 h after HI. Dilatation of ventricle and formation of capsular space beneath white matter had been observed by 14 d after HI. (2) Disregulation, pyknosis, mitochondrion swelling and chromatin agglutination were observed in WMD groups. The maldevelopment of myelins in WMD groups was detected at 1 h after HI. (3) The fluorescent stains decreased on cellular membrane, but increased in cytoplasm with time. The percentage of non-integrity cells was significantly higher (P < 0.05) in HI groups (0.32 +/- 0.04, 0.43 +/- 0.04, 0.56 +/- 0.03, 0.65 +/- 0.04, 0.87 +/- 0.03) than the controls (0.02 +/- 0.01, 0.02 +/- 0.01, 0.01 +/- 0.01, 0.02 +/- 0.01, 0.02 +/- 0.01). (4) The expression of RhoA mRNA was significantly increased (P < 0.05) in HI groups (1.205, 2.415, 4.830, 1.500) in the white matter tissue compared with the controls (0.300, 0.375, 0.375, 0.530) at 12 h, 24 h, 48 h, 72 h after HI. The expression of RhoA mRNA reached the peak value at HI 48 h, and then gradually decreased. The expression of RhoA mRNA at HI 7 d in WMD group (0.500) was not significantly different from the control (P > 0.05)., Conclusion: (1) The pathological and ultrastructural changes of white matter in WMD groups after HI suggest that the WMD model was successfully set up in premature 2 days SD rats. (2) F-actin is redistributed within cells after HI: expression in membrane is decreased and expression in plasma was increased. The redistribution possibly results in the collapse and retraction of cells. (3) The expression of RhoA mRNA is increased significantly after HI, which may lead to the redistribution of F-actin. (4) The increase of the expression of RhoA mRNA is not persistent, but the redistribution of F-actin is continued, which suggests that RhoA may not be the only factor affecting the redistribution of F-actin.

Objective: This study examined the NgR expression in oligodendrocyte precursor cells (OLPs) and its changes after oxygen & glucose deprivation (OGD) in order to explore the role of NgR expression in the regeneration of OLPs after OGD in neonatal rats., Methods: The OLPs from 2-day-old neonatal rats were separated by improved separation and purification through agitation and then cultured in chemically defined medium. OLPs OGD model was prepared using the medium consisting of Na2S2O4 and Earle's fluid in vitro. Immunofluorescence assay was applied to identify the OLPs with its specific antibodies such as A2B5, O4 and O1. Western blot was used to detect the NgR expression in OLPs 10 and 30 minutes after OGD. The livability rate of cells was detected by MTT., Results: NgR expression was found in both the cell body and the prominence of purified OLPs. NgR expression in OLPs increased significantly 10 and 30 minutes after OGD compared with that in OLPs without OGD (controls, P < 0.05). MTT showed that the livability rate of OLPs at 30 minutes following OGD was significantly lower than that of controls (65.97+/-3.69% vs 97.17+/-6.88%, P < 0.05)., Conclusions: NgR is expressed in both the cell body and the prominence of OLPs. NgR expression increases while cell livability decreases following OGD, suggesting that NgR may play a role in the inhibition of regeneration of OLPs.

Objective: To identify the expression of micro-calpain mRNA and protein in cerebral tissues of neonatal rats after hypoxic-ischemic brain damage (HIBD) and its role in the pathogenesis of HIBD., Methods: Seven-day-old Sprague-Dawley rats were randomly divided into seven groups: control group and groups with 0, 6, 12, 24, 48, and 72 hours of exposure to HIDB. Quantitative real-time fluroscent polymerase chain reaction and Western blot technique were employed to detect the expression of micro-calpain mRNA and its protein respectively., Results: The micro-calpain mRNA in the ipsilateral cerebral tissues began to increase 6 hours after the HIDB and reached peak at 24 hours, and then gradually decreased but remained in a higher level than that of the control group until at 72 hours (P < 0.05). The activated micro-calpain protein started to increase 6-12 hours after the HIDB (P < 0.05) and reached peak at 24 hours (P < 0.01). Higher levels of micro-calpain protein were maintained until 48 and 72 hours after the HIBD (P < 0.05)., Conclusion: The expressions of micro-calpain mRNA and protein increase with the HIBD. The micro-calpain may play a role in the pathogenesis of the HIBD.

Objective: To study the expression of the AMPA receptor subunit glutamate receptor 2 (GluR2) and the cellular free calcium concentration in the white matter of neonatal rats with periventricular leukomalacia (PVL) and their roles in the pathogenesis of PVL., Methods: A PVL model was prepared by unilateral carotid artery ligation (UCL) followed by exposure to 6% oxygen for 4 hrs in 2-day-old rats. The neonatal rats performed a sham operation, without hypoxia-ischemia (HI), were used as the control group. At 12, 24, 48 and 72 hrs of HI, the expressions of GluR2 mRNA and protein in the white matter were detected using real time quantitative PCR and Western blot respectively. Spectrophotofluorimetry and Fura 2/AM were used to detect the cellular free calcium concentration., Results: The expressions of GluR2 mRNA and protein in the white matter were significantly reduced in the PVL group at 24 hrs of HI, and remained at lower expressions until 72 hrs of HI compared with the control group (P < 0.05). The cellular free calcium concentrations increased significantly in the PVL group at 12 hrs of HI, and remained at higher levels until 72 hrs of HI compared with the control group (P < 0.05)., Conclusions: The expressions of GluR2 mRNA and protein in the white matter decreased whereas the cellular free calcium concentration increased in neonatal rats with PVL. The decreased expression of GluR2 might lead to the overloading of cellular calcium in the white matter, which may cause neuronal damage and death.

Objective: Recent studies have indicated that the signal pathway of NgR-P75NTR- RhoA plays a key role in nerve injury and remodeling, but its exact mechanism and the role of the downstream molecule RhoA regulated by P75NTR remain unclear in hypoxia-ischemia (HI) neonatal animals. The present study was designed to assess the expression of P75NTR protein and RhoA mRNA in neonatal white matter and to investigate their relationship in newborn rats with white matter damage (WMD)., Methods: The rat WMD model was established by the ligation of right common carotid artery, followed by 6% hypoxia exposure for 4 hrs. The control group was sham-operated, without HI treatment. The histological changes of brain tissue were observed under light and electron microscopes. Expression of P75NTR protein and RhoA mRNA in the brain white matter after 12, 24, 48 and 72 hrs and 7 days of HI were detected by RT-PCR and immunohistochemistry, respectively., Results: Periventricular white matter damage was observed by 48 hrs of HI. Expression of P75NTR protein increased in the striatum and callosum zones at 12 hrs, peaked at 48 hrs, and remained at a higher level than control until 72 hrs of HI in the WMD group (P < 0.01). After 7 days of HI expression of P75NTR protein was no longer statistically different from controls. The RhoA mRNA was higher in the WMD group for the first 72 hrs and then declined to control values., Conclusions: Increased P75NTR protein might mediate apoptosis of nerve cells and inhibit the regeneration of neuron axons. The subsequent decline back to control value may be correlated with the aggregation of necrosis of nerve cells after HI. The patterns of RhoA mRNA expression were consistent with those of P75NTR protein, suggesting that the increased P75NTR level may promote RhoA mRNA expression.

A comprehensive phylogenetic classification of the kingdom Fungi is proposed, with reference to recent molecular phylogenetic analyses, and with input from diverse members of the fungal taxonomic community. The classification includes 195 taxa, down to the level of order, of which 16 are described or validated here: Dikarya subkingdom nov.; Chytridiomycota, Neocallimastigomycota phyla nov.; Monoblepharidomycetes, Neocallimastigomycetes class. nov.; Eurotiomycetidae, Lecanoromycetidae, Mycocaliciomycetidae subclass. nov.; Acarosporales, Corticiales, Baeomycetales, Candelariales, Gloeophyllales, Melanosporales, Trechisporales, Umbilicariales ords. nov. The clade containing Ascomycota and Basidiomycota is classified as subkingdom Dikarya, reflecting the putative synapomorphy of dikaryotic hyphae. The most dramatic shifts in the classification relative to previous works concern the groups that have traditionally been included in the Chytridiomycota and Zygomycota. The Chytridiomycota is retained in a restricted sense, with Blastocladiomycota and Neocallimastigomycota representing segregate phyla of flagellated Fungi. Taxa traditionally placed in Zygomycota are distributed among Glomeromycota and several subphyla incertae sedis, including Mucoromycotina, Entomophthoromycotina, Kickxellomycotina, and Zoopagomycotina. Microsporidia are included in the Fungi, but no further subdivision of the group is proposed. Several genera of 'basal' Fungi of uncertain position are not placed in any higher taxa, including Basidiobolus, Caulochytrium, Olpidium, and Rozella.

Unlabelled: OBJECTIVE To study the expression of NgR mRNA and NgR protein in the brain tissues of newborn rats with hypoxic ischemic brain damage (HIBD) its implications., Methods: Seventy two newborn SD rats (7 days) were randomly divided into two groups, with or without surgical induced HIBD. RT-PCR was used to detect the expression of NgR mRNA. The immunohistochemistry method and the Western Blot were used to detect the distribution and expression of NgR protein in the brain tissues., Results: Compared with the rats without HIBD, the expression of NgR mRNA and protein in the rats with HIBD increased significantly (P< 0. 05), although the expression started to decrease after 24 hours in HIBD condition., Conclusion: Increased NgR mRNA and NgR protein may be associated with the hypoxic-ischemic injury and may inhibit the neuron regeneration. The decreased expression of NgR mRNA and protein at a later stage may be associated with the loss of nerve cells.

Objective: To explore the role of high-risk human papillomavirus (HPV) DNA testing in improvement of recognition of cervical intraepithelial lesions (CIN) 2, 3 or cervical cancer confirmed by biopsy in women with abnormal cervical cytology including atypical squamous cells undetermined significance (ASC-US) and low squamous intraepithelial lesion (LSIL)., Methods: Total 940 patients with abnormal cervical liquid-based cytology including ASC-US and LSIL were included in this study. Hybrid capture II assay was applied in the high-risk HPV detection. The cervical pathologic diagnoses were obtained under colposcopy guided biopsy., Results: Of the 940 cases, 497 were ASC-US, and 443 LSIL. With pathological diagnosis of cervical biopsy, 417 cases were chronic inflammation, 315 condyloma, 124 CIN 1, 65 CIN 2, 19 CIN 3 or cervical cancer. The positive rate of high-risk HPV DNA in groups of ASC-US and LSIL were 59.6% and 84.9%, respectively. In each group of abnormal cytology, detection rates of CIN 2, 3 or cervical cancer in patients with positive HPV DNA were 8.8% and 14.1%, respectively, which were higher than those with negative HPV DNA (0.2% and 6.0%, P < 0.05). In group of ASC-US, high-risk HPV DNA test had a negative predictive value of 99.5%; detection rates of CIN 2, 3 or cervical cancer in patients with HPV DNA virus load 1-9.99 and > or = 10 was 1.6% and 10.7%, respectively., Conclusion: High-risk HPV DNA test were helpful to improve the detection rates of CIN 2, 3 or cervical cancer in patients with ASC-US.

Buprenorphine is available in Singapore as substitution treatment for opioid dependence since 2002. This study surveys buprenorphine related deaths in Singapore between September 2003 and December 2004. The aims are to establish the autopsy prevalence of buprenorphine related deaths and the demographical and toxicological profile of the cases. Toxicological screening was performed for all unnatural deaths, deaths involving known drug addicts, as well as when autopsy revealed no obvious cause of death. Twenty-one cases had buprenorphine detected in post-mortem blood and/or urine samples. Eighteen were sudden deaths. There were two fatal falls from height and one death by hanging. All subjects were male. The age range was 24-48 years. Fourteen subjects were between 30 and 39 years of age. The mean age was 35 years. The majority (62%) were Chinese. Eleven (52%) were known drug abusers. For sudden deaths, two groups were identified. Six cases died from natural causes. Blood buprenorphine levels ranged from undetected (detected in urine) to 3.2 ng/mL (mean 1.4 ng/mL). Twelve cases were attributed directly and indirectly to mixed drug poisoning. Blood buprenorphine levels ranged from undetected (detected in urine) to 17 ng/mL (mean 3.2 ng/mL). Nineteen cases showed concurrent abuse of buprenorphine and benzodiazepine, diazepam being the most frequently detected, followed by nitrazepam and midazolam. The availability of buprenorphine as substitution therapy is associated with an increase in buprenorphine related deaths. The danger of co-abuse of buprenorphine and benzodiazepines is highlighted.

Increased venous compliance in lower limbs may be contributed to postflight orthostatic intolerance; however, direct animal studies to address the changes of venous compliance to microgravity have been rare. The purpose of this study was to determine compliance changes in femoral veins of rabbits after 21 days of head-down rest. Head-down rest -20 dgrees rabbit model was used to simulate weightlessness. 24 healthy male New Zealand Rabbits were randomly divided into 21 days of head-down rest group (HDR), horizontal immobilization group (HIG) and Ctrl group (Ctrl), with 8 in each. We constructed pressure-volume relationships from femoral veins in vivo for all groups after simulation by changing the venous internal volume and measuring the corresponding pressure. Microstructure of femoral vein wall in 3 groups was observed. Compared among the groups, the corresponding intravenous pressure of Ctrl was the highest when intravenous volume was expanded and HDR was the lowest. The parameter 3 , and P 2 in quadratic equations of femoral venous P-V relationship of HDR group were significantly higher than these values of HIG group and Ctrl group. The structure of femoral vein wall of HDR rabbits changed significantly, outlines of some endothelium cells (EC) became short and columnar or cubic, some of EC fell off and smooth muscle layer became thinner. These results indicate that, the femoral venous compliance increased after weightlessness simulation. This may partially underlie the mechanism of orthostatic hypotension seen in astronauts during an orthostatic stress after exposure to microgravity.

This study was designed to examine the associations between serum polychtorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) levels and adverse hepatic-related health outcomes. Residents living in the vicinity of a closed pentachlorophenol (PCP) manufacturing factory (exposure area) and other areas nearby (control area) were identified from prior investigation of serum PCDD/Fs measurements. A total of 85 subjects were recruited for the study, 52 from exposure area and 33 from control, respectively. Average level of serum PCDD/Fs was 80.1 6 50.9 pg WHO-TEQ/g lipid for those residing in exposure area, and 25.5 6 18.2 in control area. Statistically higher odds ratio (ORs) for fatty liver and gamma-glutamyltransferase (GGT) activity was found in subjects with higher serum PCDD/Fs levels and high body mass index (BMI) as compared to those with lower PCDD/Fs levels and less BMI. Data suggest that dioxin exposure and high lipid content affect the prevalence of fatty liver in exposed subjects. Future study should be directed to prevent continuous exposure to environmental PCDD/Fs from the defunct PCP factory, and to characterize prospectively, with a larger study sample size, the potential long-term consequences on hepatic function associated with contaminant exposure.

Objective: This study investigated the 8003 base pair (bp) fragmentation damage of brain mitochondrial DNA in newborn piglets at different times after hypoxic-ischemic brain damage (HIBD) so as to explore the biomolecular foundation of neonatal neuronal metabolic disorders., Methods: Fifty 3-day-old piglets were randomly assigned into Control and HIBD groups. The HIBD group was subdivided into groups sacrificed at 0, 24, 48 and 72 hrs post-HIBD (n=10). HIBD was induced by left carotid ligation and exposure to 8% oxygen for 2 hours. The Control group was exposed to air and was sham-operated. The left hippocampal cortexes of all subjects were obtained to amplify the fragments of 200 bp and 8003 bp by the LX-PCR method. The PCR products were electrophoresed on agaros gels to obtain the integral optical density (IOD)., Results: The IOD of 8003 bp fragment was markedly reduced in the HIBD 0 hr group (22.616 +/- 2.276) when compared with that of the Control group (56.995 +/- 0.317) (P < 0.05). The IOD value remained lower at 24 hrs (27.719 +/- 0.309) and 48 hrs post-HIBD (49.491 +/- 3.233) (P < 0.05). Until 72 hrs post-HIBD, the IOD (55.972 +/- 2.236) restored to the control value., Conclusions: The brain mitochondrial DNA was fragmented in newborn piglets following brain hypoxia-ischemia. It did not recover to normal until 72 hrs post-HIBD. The fragmentation damage of mitochondrial DNA may be related to the depression of mitochondrial respiratory enzymes activity and neuron apoptosis.

Objective: To study the changes of ADF and G-actin in renal tubular epithelial cell of neonatal rats during kindney ischemic injury. To explore the interactions between ADF and G-actin and their relationships with actin cytoskeleton., Methods: Twenty-four neonatal rats were used to the experiments due to have the weights from 30 to 40 g respectively. Renal ischemia was induced by clamping the left renal pedicle for different periods of time that was in 10 min or 30 min. The kidneys of normal neonatal rats were functioned as the control group. Two kinds of primary antibodies, which one was rabbit anti-chick ADF antiserum and another was mouse monoclonal G-actin antibody, were used on one same section of kidney tissue. FITC-labeled and TRITC-labeled secondary antibodies were used to identify ADF and G-actin respectively. These samples were examined by using a fluorescene microscope., Results: In control group, ADF and G-actin showed to be diffused in cytoplasm of renal tubular epithelial cell. In ischemic injury group, the distributions of ADF and G-actin were changed significantly to apical region of tubular epithelial cells and the renal tubula lumen. Regardless of the ADF expression to not change but G-actin was increased after kidney ischemia., Conclusion: Under the physiolgical condition, ADF and G-actin got a diffuse distribution in cytoplasm of renal tubular epitbelial cell. However, when the kidney got in ischemia, the distributions of ADF and G-actin were changed significantly to apica region of tubular epithelial cell or the renal tubular lumen.

Objective: To investigate the expression of aquaorin-4 (AQP4) in the cultured neonatal rat primary astrocytes during hypoxia and during reoxygenation after hypoxia., Methods: The astrocytes were randomly assigned to the hypoxia group (the astrocytes were exposed to hypoxia for 3 h, 6 h, 12 h and 24 h respectively), the reoxygenation group (after exposure to 12 h hypoxia, the astrocytes were returned to normoxic cultures for 3 h, 6 h, 12 h and 24 h respectively), and the normoxic group (control group). AQP4 mRNA expression in astrocytes of all groups was detected by Real Time PCR, and AQP4 protein expression was determined by immunofluorescence., Results: The AQP4 mRNA and protein expressions significantly decreased with the time of hypoxia, and during reoxygenation, the decreased expressions were gradually up-reguated., Conclusion: It is likely that the decreased expression of AQP4 is associated with brain edema and in such brain edema conditions AQP4 may play a prominent role in the reestablishment of brain osmotic equilibrium.

Intrastrain internal transcribed spacer (ITS) heterogeneity is first reported from Ganoderma, a fungal genus within Basidiomycetes. ITS amplification products from 4 strains, representing 4 Ganoderma species, were cloned and sequenced. Two to five different ITS types were found within a single strain. The clone sequences were analyzed along with other sequences from Ganoderma retrieved from GenBank. The results show that sequence variation within strains varies considerably with species and the heterogeneity may occur in the 3 parts (ITS1, ITS2, and 5.8S) of the ITS region.

Aims: The nutritional requirements for mycelial growth of Cordyceps sinensis in semi-synthetic liquid media were investigated. The results provide a basis for further physiological study and industrial fermentation of the fungus., Methods and Results: Nutritional requirements, including 17 carbohydrates, 16 nitrogen compounds, nine vitamins, four macro-elements, four trace-elements and eight ratios of carbon to nitrogen, were studied for their effects on the mycelial growth in submerged cultures of C. sinensis by using one-factor-at-a-time and orthogonal matrix methods. Among these variables, sucrose, peptone, folic acid, calcium, zinc and a carbon to nitrogen ratio 12 : 1 were identified as the requirements for the optimum mycelial growth. The concentrations of sucrose, peptone and yeast extract were optimized and the effects of medium composition on mycelial growth were found to be in the order sucrose > yeast extract > peptone. The optimal concentration for mycelial growth was determined as 50 g l(-1) sucrose, 10 g l(-1) peptone and 3 g l(-1) yeast extract., Conclusions: Under optimal culture conditions, over 22 g l(-1) of mycelial biomass could be obtained after 40 days in submerged cultures., Significance and Impact of the Study: Cordyceps sinensis, one of the most valued medicinal fungi, is shown to grow in axenic culture. This is the first report on nutritional requirements and design of a simplified semi-synthetic medium for mycelial growth of this psychrophilic species, which grows slowly below 20 degrees C. The results of this study will facilitate research on mass production of the fungus under defined culture conditions.

Background: The purpose of this study was to investigate cerebral blood flow (CBF) velocity in humans during 21 days of head-down tilt (HDT) bed rest with and without lower-body negative pressure (LBNP)., Material/methods: Twelve healthy male volunteers were exposed to -6 degrees HDT bed rest for 21 days. Six subjects received -30 mmHg LBNP sessions for 1 h per day from the 1st to the 7th day and from the 15th to the 21st day of HDT, and six others served as controls. CBF velocity was measured by use of the transcranial Doppler technique in the right middle cerebral artery before and during HDT., Results: In the control group, mean and systolic CBF velocities decreased on day 1 of HDT compared with the pre-HDT value, and dropped further on day 3 of HDT, then remained significantly below the pre-HDT baseline on days 7 and 10 of HDT, and reached a minimum value on day 21 of HDT. In the LBNP group, mean and systolic CBF velocities decreased significantly on day 1 of HDT compared with the pre-HDT value, and remained lowered throughout HDT. Diastolic CBF showed no significant change throughout HDT in both groups. There were no significant differences in these parameters between the two groups., Conclusions: The results of this study suggest that CBF velocity is reduced during 21 days of HDT, and brief daily LBNP sessions used in the first and last weeks of 21-day HDT bed rest does not improve CBF velocity.

Objective: To determine whether effect of energy metabolism on G1/S renal tubular epithelial cells (RTEs) is strongly associated with anoxemia., Methods: Neonatal pig's RTEs were synchronized by the Excess Thymidine Block technique and the distribution of G1/S phases was determined by flow cytometry (FACS). The hypoxic-cell model of G1-phase RTEs was established by exposure of the RTEs to sodium cyanide (NaCN), and the preventive (NaCN+Cantharidin) group and un-treated control group were set up at the same time. The ATP levels in three RTEs groups were measured by high-performance liquid chromatography., Results: FACS measurements revealed that (99.52 +/- 0.83) % of the neonatal RTEs were at G1/S transition. The concentration of ATP in the RTEs of hypoxic group at 0, 60, 120 minutes after with NaCN treatment for one hour was higher than that of the preventive group and un-treated control group (P<0.05). At 180 minutes after NaCN treatment, the RTEs' ATP in hypoxic group was significantly reduced as compared with those of the preventive and un-treated control groups (P<0.05)., Conclusion: Abnormal energy metabolism in newborn piglet's RTEs is significantly associated with anoxia that may further interfere with the advance of RTEs' cell cycle and Cantharidin can regulate the ATP metabolism of hypoxic RTEs.

DNA sequences of the internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (nrDNA) and small-subunit of mitochondrial ribosomal DNA (mt-rDNA) were obtained from 12 different collections initially identified as either Postia caesia or P. subcaesia based on morphological criteria. Sequences of ITS from British collections separate into three clear groups, each with identical sequences, regardless of the lignicolous host and distribution. These British collections can be distinguished morphologically as two groups, (a) thick and larger basidiomata (1.5-5.0x2.0-6.0x3.0-15 cm) with a strigose to tomentose pileus and (b) thin and smaller basidiomata (0.5-2.0x1.0-2.5x1.5-4.0 cm) with a smooth pileus. The former were all collected from hardwoods and the latter from both hardwoods and coniferous woods. Group (a) corresponds to one of the sequence groups, but group (b) displays two different sequences. Two collections from Norway, one from each of the morphological groups, exhibit further sequence variation within the ITS regions, although closer to those of British group (b). Representative sequences of mt-rDNA from each of the three British ITS sequence groups remain distinct, but those from the two Norwegian collections, however, are identical to one of the British groups. Further comparison of basidiospore size revealed no clear distinction among these groups, although the ratio of spore length to spore width is generally greater in group (a). Although there is no clear separation of these collections into two species, there is a clear tendency of variation at both morphological and molecular levels, among them. Differences in morphology and DNA sequences do not warrant species recognition, but do demonstrate high variability within the species complex.

The new species, Termitomyces bulborhizus, is described from south-west China. The stipe of the basidiome is swollen into a prominent bulbous base at ground level, and this, together with the floccules on the stipe surface, distinguishes this species within the genus. T. bulborhizus is compared with closely related species, including three originally described from China, and a key to T. bulborhizus and related species is provided.

Objective: To study the mechanism of cantharidin in protecting F-actin microfilaments from disruption by hypoxic damage by observing the effects of cantharidin on intracellular ATP metabolism in G(1)/S-phase renal tubule epithelial cells (RTECs)., Methods: G1-phase RTECs were divided into cantharidin-treated group, exposed to sodium cyanide (CN) and cantharidin, hypoxic-group with CN exposure and non-treated control group. ATP levels were measured in the 3 groups with high-performance liquid chromatography., Results: The concentration of CN exposure for 1 h, ATP level in the RTECs with cantharidin treatment were significantly higher than that in both hypoxic and non-treated control groups (14.50+/-0.26 mmol/g protein, 4.25+/-0.11 mmol/g protein, 8.58+/-0.13 mmol/g protein, respectively, P<0.01)., Conclusion: Cantharidin prevents the disruption of the actin cytoskeleton in hypoxic damage by preventing abnormal intracellular ATP metabolism.

Objective: To observe the distribution and change of insulin-like growth factor-1 receptor (IGF-1R), estrogen receptor-alpha (ER-alpha) and their co-expression in the brains of normal newborn female rats and in the brains of those with hypoxic-ischemic brain damage (HIBD)., Methods: The 7 day-old female SD rats were subjected to the ligation of right carotid artery (ischemia), then they were put into a box full with 8% oxygen and 92% nitrogen for an hour (hypoxia). The methods of immunohistochemistry and double-immunohistochemistry were used to detect the expression of IGF-1R, ER-alpha and their co-expression in the brain., Results: (1) There were extensive immunoreactions of IGF-IR, ER-alpha in newborn rat's brain, and there were extensive co-localization of IGF-1R and ER-alpha in the same cells of cerebral cortex. (2) There were no changes in the expressions of IGF-1R and ER-alpha, no changes in the co-expression of IGF-1R and ER-alpha at 24 hours of HIBD; whereas there were increasing expressions of IGF-1R, ER-alpha and increasing co-expression of IGF-1R, ER-alpha in the cerebral cortex on the 7th day of HIBD., Conclusion: The above results suggest that there are co-action of IGF-1R and ER-alpha in the repair of hypoxic-ischemic brain damage.

Objective: To investigate the variations of actin of newborn porcine Renal Tubalar Epithelial (RTE) cell during ATP deficiency and shed light on the possible mechanisms of renal deficiency during newborn asphyxia., Methods: After the establishment of ATP deficiency cell-model, the ATP content of the RTE cell of the control and hypoxic groups was determined. And the variations of actin in newborn porcine RTE cell during ATP deficiency were detected using flow-cytometry., Results: It was found that the ATP content of new-born porcine RTE cell decreased with the continuance of hypoxia, and the changes in G-actin and F-actin contents of RTE cell both appeared at the time of one-minute ATP deficiency. The G-actin decreased first and then increased, and the F-actin decreased step by step., Conclusion: As the ATP deficiency time elongated, G-actin of the newborn porcine RTE cell decreased first and then increased, and the F-actin decreased step by step. This may destruct the cell bone-skeleton of the newborn RTE cell and maybe one of the important mechanisms of renal deficiency during newborn asphyxia.

A 42-year-old female developed fulminant hepatic failure after having ingested an undetermined quantity of a herbal product over a period of approximately four months prior to the onset of her illness. Clinically, the cause of liver failure was assessed to be drug-induced and she eventually underwent total hepatectomy, with porto-caval shunting, in anticipation of a living-unrelated liver transplant. Unfortunately, her condition deteriorated and she died less than 48 hours post-operatively, approximately three weeks post-admission. An autopsy showed that the subject was deeply jaundiced and severely obese (BMI: 47.1 kg m(-2)), with evidence of diffuse haemorrhage, including the presence of 1.35 l of blood in the peritoneal cavity. The liver had been removed and was later recovered as a formalin-fixed specimen which was markedly contracted, comprising multiple micronodules interspersed with extensive areas of dense fibrotic tissue. Histologically, there was massive necrosis of the hepatic parenchyma, such that the residual hepatocytes were disposed as nodules displaying variable cellular regeneration and ballooning degeneration, attended by florid ductal proliferation and mixed inflammatory infiltrates. Infective, autoimmune, metabolic, vascular, neoplastic and most other natural causes of massive hepatocellular necrosis were effectively excluded. Analysis of the post-mortem blood samples yielded fluconazole, metronidazole, frusemide, lignocaine and tramadol, (therapeutic agents administered to the patient during her last illness). Subsequent analysis of the residual capsules revealed that they were adulterated by fenfluramine, N-nitrosofenfluramine (1.3-1.6 mg per capsule), nicotinamide (13.3-15.6 mg per capsule) and thyroid extract. None of the herbal ingredients is currently known to be hepatotoxic and much the same applies to fenfluramine, nicotinamide (except when taken in mega-doses) and thyroid extract. However, as nitrosamines are known to be variably hepatotoxic, it would be reasonable to surmise that, in the absence of a more plausible cause of liver damage, N-nitrosofenfluramine was the likely cause of massive hepatocellular necrosis in this instance.

Background: The increased femoral venous compliance is one of the factors of orthostatic intolerance after space flight. The purpose of this study was to observe the effect of daily head-up tilt (HUT) on stress-strain relationship of femoral vein during simulated weightlessness in rabbits., Methods: Head-down tilt (HDT) 20 degrees rabbit model was used to simulate weightlessness. Twenty-four healthy male New-Zealand rabbits were randomly divided into three groups: simultaneous control, 21 d HDT, and 21 d HDT plus daily 2 h HUT 45 degrees, with 8 in each. Twenty-one days later, stress-strain relationship of femoral vein was examined., Results: Under the same stress, the circumferential strain both in the 21 d HDT group and the 21 d HDT plus daily 2 h HUT group increased significantly than those in the control group. There were no significant differences between these two groups. There were no significant changes in the longitudinal strain among three groups under the same stress., Conclusions: The femoral venous compliance of rabbits increase significantly after 21 days simulated weightlessness. Daily 2 h HUT 45 degrees could not prevent increase of femoral venous compliance in rabbits induced by 21 days simulated weightlessness.

Objective: To explore the changes of cardiac function and lower body negative pressure tolerance after self-generated Lower Body Negative Pressure device training and provide experimental evidences for its appliance., Method: Twelve healthy male subjects were randomly divided into two groups, and received training on two conditions for entirely closing the valve or opening to -30 mmHg of peak LBNP separately. The group A was trained for five days and three minutes per day. Heartfunction, HUT and tolerance of LBNP were measured in pre-training, 3 d and post-training. The group B was trained for ten days and five minutes each day. All the measurements that was the same as in group A were made., Result: Heart function of group A decreased and tolerance of LBNP increased significantly (P<0.05). In group B, heart function increased significantly after 8 days training, so did tolerance of LBNP., Conclusion: It suggested that lower body negative pressure tolerance could be improved by self-generated Lower Body Negative Pressure device training. The changes of cardiac function, however, were based on the project of training.

Objective: To study the change of beta 1-integrin in neonatal rats with ischemic renal injury., Methods: Twenty-four neonatal rats weighing from 30 to 40 g were chosen. Anesthesia was carried out by peritoneal injection of nembutal-sodium solution (4 mg/100 g). Renal ischemic injury model was induced by clamping the left renal pedicle for different periods of time. The kidneys of normal neonatal rats were functioned as the control group. Immunofluorescence technique was used to detect the location of beta 1-integrin in kidney, especially in cortex., Results: In control group, beta 1-integrin subunit was found to be located mainly in the basal membrane of tubular epithelial cell. After 10 minutes of ischemia, immunostaining highlighted the broken basement membranes of the experiment groups. The longer the ischemia continued, the more the broken points we observed. There were significant differences between the experiment groups and the control group. Yet, no significant difference in the IOD value of beta 1-integrin was seen between the 10-min-ischemia and 30-min-ischemia groups., Conclusion: Under physiological condition, beta 1-integrin is distributed over the basal membrane of the tubular epithelial cell of neonatal rat. Ischemic injury can cause the changes of beta 1-integrin which may be the reason of exfoliation and depolarization of tubular epithelia cell.

Objective: By studying the distribution and expression of beta 1-integrin and its mRNA in renal tubular epithelial cell at different ischemia/reperfusion time phases we probe the role of beta 1-integrin in I/R injury of neonatal animals., Methods: The neonatal SD rat ischemia/reperfusion model was set up. Immunofluorescent staining and in situ hybridization (ISH) were used to show the distribution and expression of beta 1-integrin with its mRNA in renal tubular epithelial cells and the quantities of beta 1-integrin and its mRNA were counted by ImagePlus-Pro system., Results: 1. beta 1-integrin was located at the basal plasma membrane in normal renal tubular epithelial cells. After ischemia for 0.5 h, the redistribution was not significant. After reperfusing for 0.5 h, beta 1-integrin began to move onto the lateral and apex surfaces of cells. This kind of change was most apparent after reperfusion for 2 h and was accompanied with reduced expression and destruction of renal tubular. No positive dying was seen in the lumen. The regeneration started 24 hours post-ischemia. beta 1-integrin was redistributed onto the basal plasma membrane. After reperfusion for 120 hours, the regeneration ended, but the expression did not gain the normal level. 2. The mRNA of beta 1-integrin was mainly expressed in the cell plasma. Its expression was increased while reperfusion for 0.5 h to 2 h and was still above normal level after 24 h to 120 h of reperfusion., Conclusion: The distribution of beta 1-integrin was "depolarized" and its expression was reduced. But the level of mRNA was raised, which indicated that during ischemia/reperfusion injury, there were mechanisms that influenced the distribution and synthesis of beta 1-integrin at the same time.

Objective: To study the protective effects of repeated +4 Gz/3 min exposures on memory and balance changes induced by +10 Gz/5 min exposure in rats., Method: 32 male SD rats were randomly divided into 4 groups: control group (C) ; +10 Gz/5 min group (10 Gz); 3 d training group (3 d) ; 5 d training (5 d) group (exposed to +4 Gz/3 min per day for 3 or 5 days before +10 Gz/5 min exposure). Changes of memory and balance in rats of all the 4 groups were observed after +10 Gz/5 min exposure., Result: In +10 Gz group, the percentage of correct reaction (CR) decreased significantly at all times after +10 Gz exposure (P<0.01), and the reaction time (RT) lengthened significantly at all times after +10 Gz exposure (P<0.01); as compared with control group. In 3 d training group, CR decreased significantly at 1 d, 2 d and 6 d after +10 Gz exposure (P<0.05), RT lengthened significantly at all times after +10 Gz exposure (P<0.05); as compared with control group. CR increased significantly at 2 d, 4 d and 6 d after +10 Gz exposure (P<0.01), RT shortened significantly at 1 d, 2 d, 4 d and 6 d after +10 Gz exposure (P<0.01) as compared with +10 Gz group. In 5 d training group, there were no apparent changes compared to control group; but CR increased significantly and RT shortened significantly at the time of 1 d, 2 d, 4 d and 6 d after +10 Gz exposure (P<0.01) as compared with +10 Gz group. Balancing function (BF) of +10 Gz group decreased significantly immediately and 2 d after +10 Gz exposure (P<0.01) as compared with control group. BF in 3 d and 5 d training group improved significantly immediately and 2 d after +10 Gz exposure as compared with +10 Gz group (P<0.01)., Conclusion: It is suggested that repeated low +Gz exposures could provide protective effect on memory and balance changes induced by high +Gz exposure in rats.

Objective: To clarify the effect of hypoxia and ischemia on the concentration of Ca2+ in myocardial mitochondria, and on the activity of respiratory chain complex IV--cytochrome oxidase (CCO) in neonatal swines, and to find out the change of myocardial mitochondria during hypoxic-ischemic brain damage (HIBD)., Methods: The study was performed on neonatal swines. For establishment of HIBD model, the left carotid was ligated and the swine was placed under hypoxia for two hours. Then the concentration of Ca2+ and the activity of respiratory chain complex IV in myocardial cell mitochondria were measured at 0 hour and 24, 48, 72 hours after reoxygenation. The measured values from these 0-, 24-, 48-, 72-hour-HIBD-groups (n = 10 per group) and from the normal control group (n = 10) were statistically analyzed by means of ANOVA, Newman-Keuls test and linear correlation., Results: After the swines were placed under hypoxia-ischemia for two hours, 1. the concentration of Ca2+ in myocardial mitochondria increased, till 24 hours after re-oxygenation, and then it descended at 48 hours and 72 hours after reoxygenation; 2. the activity of myocardial mitochondrial respiratory chain complex IV descended, though activity recovery was seen at 48 and 72 hours, it did not come back to normal level at 72 hours after reoxygenation; 3. the concentration of Ca2+ in myocardial mitochondria was negatively correlated with the activity of respiratory chain complex IV., Conclusion: The results showed that in the neonatal swines with HIBD, the mitochondrial respiratory chain in myocardial cell was damaged by hypoxia-ischemia, yet it could be rehabilitated after reoxygenation. Calcium overload in myocardial mitochondria after hypoxia-ischemia might be one of the causes of the descending activity of respiratory chain complex IV.

The purpose of the present study was to investigate the changes of orthostatic tolerance and cardiac function during 21 d head-down tilt (HDT) bed rest and effect of lower body negative pressure in the first and the last week in humans. Twelve healthy male volunteers were exposed to -6 degrees HDT bed rest for 21 d. Six subjects received -30 mmHg LBNP sessions for 1 h per day from the 1st to the 7th day and from the 15th to the 21st day of the HDT, and six others served as control. Orthostatic tolerance was assessed by means of standard tilt test. Stroke volume (SV), cardiac output (CO), preejection period (PEP) and left ventricular ejection time (LVET) were measured before and during HDT. Before HDT, all the subjects in the two groups completed the tilt tests. After 10 d and 21 d of HDT, all the subjects of the control group and one subject of the LBNP group could not complete the tilt test due to presyncopal or syncopal symptoms. The mean upright time in the control group (15.0 +/- 3.2 min) was significantly shorter than those in the LBNP group (19.7 +/- 0.9 min). SV and CO decreased significantly in the control group on days 3 and 10 of HDT, but remained unchanged throughout HDT in the LBNP group. A significant increase in PEP/LVET was observed on days 3 and 14 of HDT in both groups. The PEP/LVET in the LBNP group was significantly lower on day 3 of HDT, while LVET in the LBNP group was significantly higher on days 3, 7 and 14 of HDT than those in the control group. The results of this study suggest that brief daily LBNP sessions used in the first and the last weeks of 21 d HDT bed rest were effective in diminished the effect of head-down tilt on orthostatic tolerance, and LBNP might partially improve cardiac pumping function and cardiac systole function.

Objective: To develop a kind of self-generating lower body negative pressure device., Method: The device consists of a flexible bellows, reinforced by several steel rings and sealed by gasproof adhesive plaster. An adjustable valve, a one-way flap valve, shoulder straps and handles are incorporated on the top of the bellows. The user's lower body was contained in the bellows. As the user's legs were extended, the bellows was elongated and the air pressure in it decreased., Result: Negative pressures of -58, -46, -38 and -26 mm-Hg respectively was created with the adjustable inlet valve completely closed, one-quarter open, half open, or fully open., Conclusion: This self-generating lower body negative pressure device combines exercise and LBNP into one thing and is safe and easy to use. It might be used in preventing cardiovascular deconditioning during spaceflight or for anti-G training of pilots.

Glucocorticoids are effective inhibitors of epidermal proliferation and skin tumorigenesis. Glucocorticoids affect cellular functions via glucocorticoid receptor (GR), a well-known transcription factor. Recently, we generated skin-targeted transgenic mice overexpressing GR under control of the keratin5 promoter (K5-GR mice). To test the hypothesis that GR plays a role as a tumor suppressor in skin, we bred K5-GR transgenic mice with Tg.AC transgenic mice, which express v-Ha-ras oncogene in the skin, and compared the susceptibility of F1 offspring to TPA-induced skin carcinogenesis. GR overexpression in the epidermis dramatically inhibited skin tumor development. In K5-GR/ras+ double transgenic mice papillomas developed later and the average number of tumors per animal was 15% (in males) and 40% (in females) of the number seen in wild type (w.t./ras+) littermates. In addition, the papillomas in w.t./ras+ animals were eight to nine times larger. GR overexpression resulted in a decrease in keratinocyte proliferation combined with a modest increase in apoptosis and differentiation of keratinocytes in K5-GR/ras+ papillomas. Our data clearly indicate that interference of GR transgenic protein with nuclear factor kappa B (NF-kappaB) transcription factor had resulted in NF-kappaB blockage in K5-GR/ras+ tumors. We discuss the role of NF-kappaB blockage in tumor-suppressor effect of GR.

Weightlessness is inavoidable during spaceflight. It brings profound physiological effects on human body. Vascular remodeling is one of the important changes of cardiovascular system caused by weightlessness or simulated weightlessness. The paper summarized the studies on the effects of weightlessness or weightlessness simulation on vascular remodeling in recent years. The emergence and development of the concept of vascular remodeling were briefly reviewed. The advances of study on vascular remodeling in recent years was briefly discussed with the points focused on the effects of weightlessness or weightlessness simulation on cardiovascular remodeling and its mechanism. It is proposed that cardiovascular remodeling might be important in studying the causes of orthostatic intolerance after spaceflight.

Objective: To present the development and application of a self-powered short arm human centrifuge., Method: Self-powered short arm human centrifuge consisted of human power, adjustable resistance trig, short arm and supporting construction parts. It was driven by human power. The short arm turned around the supporting part so artificial gravity is produced. The physical load can be adjusted by the adjustable resistance part. G-level depends on the rotative velocity of the central shaft. Nine healthy male volunteers received self-powered short arm human centrifuge training for 5 min per day with rotative velocity of 30-34 r min-1 for 7 d. Cardiac pumping function was measured before and after training., Result: Heart rate (HR) decreased significantly while left ventricular ejection time (LVET) increased significantly after 3 d training, and HR and LVET changed further after 7 d training. Stroke volume increased significantly only after 7 d training., Conclusion: Self-powered short arm human centrifuge combines artificial gravity and exercise and included other advantages of safety and economy of construction. Cardiac pumping function could be improved by 7 d training. It may be used for anti-G physiological training or as a countermeasure to counteract the effect of microgravity.

Objective: To explore the effect of +Gz exposure time on memory and behavior in rats., Method: Twenty-four male SD rats were randomly divided into control group (A), +10 Gz/3 min group (B) and +10 Gz/5 min group (C). Rats in group A and B were exposed to +10 Gz for 3 min or 5 min respectively. Changes of memory and behavior in rats were observed after +Gz exposure., Result: As compared with control, percentage of right reflex decreased significantly and reaction time lengthened significantly immediately, 1 d, 2 d, 4 d and 6 d after +10 Gz/5 min exposure (P<0.01); reaction time lengthened significantly immediately and 2 d after +10 Gz/3 min exposure (P< 0.01). As compared with +10 Gz/3 min, percentage of right reflex decreased significantly and reaction time lengthened significantly at 1 d, 2 d, 4 d and 6 d after +10 Gz/5 min exposure (P<0.01). As compared with control and +10 Gz/3 min, time stayed in center grille lengthened significantly immediately after +10 Gz/5 min exposure (P<0.01); balancing function decreased significantly immediately and 2 d after +10 Gz/5 min exposure (P< 0.01)., Conclusion: It is suggested that +10 Gz/ 3 min exposure may induce a provisional disturbance in memory function and a change in behavior in rats, and +10 Gz/5 min exposure may induce a sustained disturbance in memory function and an obvious change in behavior in rats.

Objective. To observe the changes of pressure-volume relationships of rabbit femoral veins and their structural changes caused by simulated weightlessness. Method. Head-Down Tilt (HDT) -20 degrees rabbit model was used to simulate weightlessness. Twenty four healthy male New Zealand Rabbits were randomly divided into 21 d HDT group,10 d HDT group and control group, (8 in each group). Pressure-volume (P-V) relationship of rabbits femoral veins was measured and the microstructure of the veins was observed. Result. The femoral vein P-V relationship curves of HDT groups showed a larger volume change ratio than that of control group. This change was that 21 d HDT group was even more obvious than that of HDT-10 d group. B1 and B2 in quadratic equations of 21 d HDT group were significantly higher than the values of both 10 d HDT group and control group during expansion (inflow) and collapse (outflow) (P<0.01). The result of histological examination showed that the contents and structure of femoral vein wall of HDT-rabbits changed significantly. Endothelial cells of femoral vein became short and columnar or cubic, some of which fell off. Smooth muscle layer became thinner. Conclusion. Femoral venous compliance increased after weightlessness-simulation and the femoral venous compliance in 21 d-HDT rabbits increased more obviously than that in 10 d-HDT rabbits. The structure of femoral vein wall had changed obviously.

Selenium compounds are potential chemopreventive agents for prostate cancer. There are several proposed mechanisms for their anticancer effect, including enhanced apoptosis of transformed cells. Because the transcription factor nuclear factor-kappa B (NF-kappa B) is often constitutively activated in tumors and is a key antiapoptotic factor in mammalian cells, we tested whether selenium inhibited NF-kappa B activity in prostate cancer cells. In our work, we used sodium selenite and a novel synthetic compound, methylseleninic acid (MSeA), that served as a precursor of the putative active monomethyl metabolite methylselenol. We found that both selenium forms inhibited cell growth and induced apoptosis in DU145 and JCA1 prostate carcinoma cells. Sodium selenite and MeSeA, at the concentrations that induced apoptosis, inhibited NF-kappa B DNA binding induced by tumor necrosis factor-alpha and lipopolysaccharide in DU145 and JCA1 prostate cells. Both compounds also inhibited kappa B. Luciferase reporter activity in prostate cells. A key to NF-kappa B regulation is the inhibitory kappa B (I kappa B) proteins that in response to diverse stimuli are rapidly phosphorylated by I kappa B kinase complex, ubiquitinated, and undergo degradation, releasing NF-kappa B factor. We showed that sodium selenite and MSeA inhibited I kappa B kinase activation and I kappa B-alpha phosphorylation and degradation induced by TNF-alpha and lipopolysaccharide in prostate cells. NF-kappa B blockage by I kappa B-alpha d.n. mutant resulted in the sensitization of prostate carcinoma cells to apoptosis induced by selenium compounds. These results suggest that selenium may target the NF-kappa B activation pathway to exert, at least in part, its cancer chemopreventive effect in prostate.

Studies on effect of simulated microgravity on cardiovascular function and counter effect of lower body negative pressure (LBNP) in recent years were summarized. The mechanism of simulated microgravity induced orthostatic intolerance may involve the reduction of cardiovascular function and cerebral blood flow, and endocrine changes. The significance of mathematical model in the study of mechanism of microgravity induced orthostatic intolerance was also discussed. The counter effect of LBNP was emphasized.