[A multicenter prospective controlled study of catheter ablation for patients with persistent atrial fibrillation using domestic 3D cardiac electrophysiological mapping system]

OBJECTIVE

To verify the safety and efficacy of the domestic 3D cardiac electrophysiological mapping system for catheter ablation of persistent atrial fibrillation (AF).

METHODS

From December 2011 to April 2014, 255 patients (184 male) with persistent AF in 13 centers were enrolled in this multicenter prospective controlled study.The patients were allocated to catheter ablation group (experiment group) and antiarrhythmics drugs cardioversion group (control group) with the ratio 2∶1 according to the patients' intention. Left atria were constructed with 3D cardiac electrophysiology mapping system, magnetic sensored saline irrigated radiofrequency ablation catheter (FireMagic™ Cool 3D) and surface reference (Columbus™). Pulmonary vein isolation and left atrial roof line, mitral annulus isthmus line, three tricuspid annulus isthmus line, superior vena cava, the coronary sinus and complex atrial fragmented potentials were targeted if necessary under the guidance of the 3D mapping system. Antiarrhythmics drugs (except amiodarone) were applied to patients for 2 to 3 months after ablation. The patients were followed up for 9 months after 3 months blanking period. The patients in the control group underwent cardioversion with amiodarone and electrical cardioversion if needed. Patients in the control group were also followed up for 9 months.

RESULTS

Of the 255 patients, 167 cases were in the experiment group and 88 cases were in the control group. In per protocol set (PPS), 155 cases were in the experiment group, 79 cases in the control group. Catheter ablation was successful for all patients in the experiment group under the guidance of the 3D cardiac electrophysiological mapping system. Pumononary veins isolation was achieved in all patients. After 9 months follow-up beyond blanking period, in full analysis set, the success rate was 66.5% (111/167) in the experiment group, which was significantly higher than that in the control group (21.6% (19/88), P<0.001). In PPS, the success rate was also significantly higher in the experiment group than in the control group (67.1% (104/155) vs. 22.8%(18/79), P<0.001). The incidence of adverse events was 19.8% in the experiment group and 13.6% in the control group(P=0.223). The adverse events associated with catheter ablation included 1 case of left subclavian hematoma, 1 case of left subclavian bleeding and 1 case of pericardial effusion, which was alleviated by pericardiocentesis. No pulmonary vein stenosis occurred.

CONCLUSION

Domestic 3D cardiac electrophysiological mapping system can safely and effectively guide catheter ablation of persistent AF.

Comparative ultrastructure of pretarsi in five calyptrate species

Pretarsi are the most important structures that allow flies to walk on various smooth surfaces and act as contact sensory organs. The pretarsal ultrastructure, including adhesive pads, claws, unguitractors, and bristles, of five calyptrate species are presented and described in detail, including Calliphora calliphoroides (Rohdendorf, 1931), Lucilia sericata (Meigen, 1826), Sarcophaga portschinskyi (Rohdendorf, 1937), Muscina stabulans (Fallen, 1817) and Portschinskia magnifica Pleske, 1926. Two types of tenent setae (spoon-tipped and spatula-tipped) are present on the ventral side of pulvilli in all species. The density of tenent setae and the pulvilli area in forelegs, midlegs, and hindlegs of both sexes are different. Among the five species, Ca. calliphoroides has unusually large pulvilli to its body size. These results provide morphological details that help to understand the movement and attachment of flies.

Effects of the aqueous extract of a Tibetan herb, Rhodiola algida var. tangutica on proliferation and HIF-1α, HIF-2α expression in MCF-7 cells under hypoxic condition in vitro

Ethnopharmacological relevance

Rhodiola algida var. tangutica is a traditional Tibetan herb. Its root and rhizome have been successfully used as an effective clinical remedy for the prevention and treatment of cancer and high-altitude sickness. This study aimed to investigate the effect of Rhodiola algida var. tangutica on hypoxic MCF-7 breast cancer cells and the underlying mechanisms.

Materials and methods

The antiproliferative effects of R. algida on MCF-7 breast cancer cells were compared in vitro under hypoxic and normal conditions by using MTT analysis. The influence of R. algida on cancer cell apoptosis was determined by flow cytometry. The expression levels of hypoxia-inducible factor (HIF)-1α and HIF-2α were evaluated by western blot analysis.

Results

R. algida inhibited the proliferation of MCF-7 breast cancer cells in a dose- and time-dependent manner. The results of flow cytometry indicated that the antiproliferative effect of R. algida was mediated by apoptosis induction. Pretreatment with R. algida significantly suppressed the hypoxia-induced proliferation and expression of HIF-1α and HIF-2α in MCF-7 breast cancer cells.

Conclusions

R. algida might exert an anti-carcinogenic effect on MCF-7 breast cancer cells by decreasing the protein levels of HIF-1α and HIF-2α, which are overexpressed under hypoxic conditions. This effect might be elicited by inhibiting the hypoxia-induced proliferation of MCF-7 breast cancer cells.

Prevalence of Mycoplasma pneumoniae: a cause for community-acquired infection among pediatric populaztion

BACKGROUND

Atypical pneumonia caused by Mycoplasma pneumoniae is a leading cause of mortality among the pediatric age group.

OBJECTIVES

Our study was designed to know the prevalence of M. pneumoniae in children with community-acquired pneumonia and the involvement in the cytoadherence to the respiratory epithelium by M. pneumoniae using electron microscopy and immuno-gold labeling technique.

MATERIALS AND METHODS

A total of 152 children of 1 month to 12 years of age of both sexes attending Hebei Provincial People's Hospital, Shijiazhuang, Hebei with diagnosed pneumonia were included in the study.

RESULTS

Out of 152 children 84 (55.3%) were males, and 68 (44.7%) were females. The mean age of the patients in the control group (50 patients) was 18.5 ± 3 months with 31 (62%) males and 19 (38%) females. IgM antibodies against M. pneumoniae were positive in 84 (55.3%) males and 68 (44.7%) females. Out of 50 patients 9 (18%) were found to positive for IgM M. pneumoniae antibodies of which four (44.4%) males and 5 (55.5%) females were positive. Our study observed that the gold particles were clustered on the filamentous extension of the tip of the cells. Out of 152 serum samples subjected to particle agglutination assay 138 (90.7%) were positive 1:320 titer, 9 were >1:80 and 3 showed titer was >1:40.

CONCLUSION

We suggest that clinicians should consider empirical therapy of broad spectrum antibiotics therapy to cover these atypical pathogens to reduce the severity before obtaining the serological results. From our study, we also suggest electron microscopic and biochemical studies for better diagnosis of these pathogens.

EPAS1 Gene Polymorphisms Are Associated With High Altitude Polycythemia in Tibetans at the Qinghai-Tibetan Plateau

OBJECTIVE

To test the hypothesis that the polymorphisms in the EPAS1 gene are associated with the susceptibility to high altitude polycythemia (HAPC) in Tibetans at the Qinghai-Tibetan Plateau.

METHODS

We enrolled 63 Tibetan HAPC patients and 131 matched healthy Tibetans as a control group, from the Yushu area in Qinghai where the altitude is greater than 3500 m. Eight single-nucleotide polymorphisms (SNPs) of the EPAS1 gene, including rs12619696, rs13420857, rs2881504, rs4953388, rs13419896, rs4953354, rs10187368, and rs7587138, were genotyped by the Sequenom MassARRAY SNP assay.

RESULTS

The frequencies of the G allele of EPAS1 SNP rs13419896 were significantly higher in the HAPC group than in the control group (P < .05). Moreover, the A alleles of rs12619696 and rs4953354 were prevalent in the HAPC group, and their counterpart homozygotes were prevalent in the normal Tibetan group (P < .05).

CONCLUSIONS

Compared with normal Tibetans, Tibetans with HAPC are maladapted and have a different haplotype in EPAS1 SNPs rs12619696, rs13419896, and rs4953354.

Comparison of a novel polytitanium chloride coagulant with polyaluminium chloride: coagulation performance and floc characteristics

Polymerized inorganic coagulants are increasingly being used in the water supply and wastewater treatment process, yet there is limited research on the development of polytitanium coagulants. The aim of this study is to synthesize polytitanium chloride (PTC) coagulants and investigate their coagulation behavior and floc characteristics for humic acid removal in comparison to polyaluminum chloride (PAC). The PTC samples with different B (molar ratios of OH/Ti) values were prepared using an instantaneous base-feeding method, employing sodium carbonate as the basification agent. The coagulation efficiency was significantly influenced by different B values. The results suggest that the humic acid removal increased with the increasing B value for PAC, while the inverse trend was observed for PTC. The optimum B value was chosen at 1.0 and 2.0 for PTC and PAC, respectively. Under the optimum coagulant dose and initial solution pH conditions, the PTC coagulant performed better than the PAC coagulant and the floc properties were significantly improved in terms of floc growth rate and floc size. However, the PAC coagulants produced flocs with better floc recoverability than the PTC coagulants.

Excision repair cross-complementation group 1 codon 118 polymorphism, micro ribonucleic acid and protein expression, clinical outcome of the advanced gastric cancer response to first-line FOLFOX-4 in Qinghai-Tibetan plateau population

CONTEXT

The excision repair cross-complementation group 1 (ERCC1) codon 118 C/T polymorphism has been associated with clinical outcome in cancer patients treated with platinum chemotherapy. Ethnic differences in the frequency of this polymorphism have been observed in Caucasian and African populations.

AIM

The aim of this study was to evaluate the frequency and survival benefit of the ERCC1 codon 118 C/T polymorphism in a high-altitude population with advanced gastric cancer.

MATERIALS AND METHODS

Polymerase chain reaction-restriction fragment length polymorphism was used to determine the frequency of ERCC1 118 codon C/T polymorphism in 206 advanced gastric cancer patients residing in the high-altitude Qinghai-Tibetan plateau. The influence of the ERCC1 codon 118 C/T polymorphism on its micro ribonucleic acid (mRNA) and protein expression, clinicopathological features; response to the platinum-based combination chemotherapy, and the outcome was evaluated.

STATISTICAL ANALYSIS

The Kaplan-Meier method was used for survival analysis. The correlation of ERCC1 codon 118 polymorphism with ERCC1 mRNA and protein expression, clinicopathological characteristics, and first-line oxaliplatin, 5-fluorouracil, and leucovorin (FOLFOX-4) response was determined by χ(2)-test.

RESULTS AND CONCLUSIONS

ERCC1 codon 118 C/T polymorphism was not associated with ERCC1 mRNA and protein expression, FOLFOX-4 response, and progression-free survival (PFS) or overall survival (OS). High ERCC1 mRNA and protein expression levels were associated with significantly lower FOLFOX-4 responses, PFS, and OS. ERCC1 codon 118 C/T polymorphism is not an important prognostic marker for advanced gastric cancer. Determination of ERCC1 mRNA and protein levels may be beneficial in predicting the response and outcome of FOLFOX-4 therapy in gastric cancer.

Observation of a charged (DD*)± mass peak in e+ e- → πDD* at sqrt[s] = 4.26 GeV

We report on a study of the process e+ e- → π± (DD*)∓ at sqrt[s] = 4.26  GeV using a 525 pb(-1) data sample collected with the BESIII detector at the BEPCII storage ring. A distinct charged structure is observed in the (DD*)∓ invariant mass distribution. When fitted to a mass-dependent-width Breit-Wigner line shape, the pole mass and width are determined to be Mpole = (3883.9±1.5(stat)±4.2(syst))  MeV/c2 and Γpole = (24.8±3.3(stat)±11.0(syst))  MeV. The mass and width of the structure, which we refer to as Zc(3885), are 2σ and 1σ, respectively, below those of the Zc(3900) → π± J/ψ peak observed by BESIII and Belle in π+ π- J/ψ final states produced at the same center-of-mass energy. The angular distribution of the πZc(3885) system favors a JP = 1+ quantum number assignment for the structure and disfavors 1- or 0-. The Born cross section times the DD* branching fraction of the Zc(3885) is measured to be σ(e+ e- → π± Zc(3885)∓)×B(Zc(3885)∓ → (DD*)∓) = (83.5±6.6(stat)±22.0(syst))   pb. Assuming the Zc(3885) → DD* signal reported here and the Zc(3900) → πJ/ψ signal are from the same source, the partial width ratio (Γ(Zc(3885) → DD*)/Γ(Zc(3900) → πJ/ψ)) = 6.2±1.1(stat)±2.7(syst) is determined.

Observation of a charged charmoniumlike structure Zc(4020) and search for the Zc(3900) in e+e-→π+π-hc

We study e+e-→π+π-hc at center-of-mass energies from 3.90 to 4.42 GeV by using data samples collected with the BESIII detector operating at the Beijing Electron Positron Collider. The Born cross sections are measured at 13 energies and are found to be of the same order of magnitude as those of e+e-→π+π-J/ψ but with a different line shape. In the π±hc mass spectrum, a distinct structure, referred to as Zc(4020), is observed at 4.02  GeV/c2. The Zc(4020) carries an electric charge and couples to charmonium. A fit to the π±hc invariant mass spectrum, neglecting possible interferences, results in a mass of (4022.9±0.8±2.7)  MeV/c2 and a width of (7.9±2.7±2.6)  MeV for the Zc(4020), where the first errors are statistical and the second systematic. The difference between the parameters of this structure and the Zc(4025) observed in the D*D[over ¯]* final state is within 1.5σ, but whether they are the same state needs further investigation. No significant Zc(3900) signal is observed, and upper limits on the Zc(3900) production cross sections in π±hc at center-of-mass energies of 4.23 and 4.26 GeV are set.

No relation between ACE-I/D polymorphism and high altitude pulmonary edema in the Han Chinese

OBJECTIVES

To explore whether the angiotensin I -converting enzyme (ACE) I/D (insertion/ deletion) polymorphism is associated with the susceptibility to high altitude pulmonary edema (HAPE) in the Han Chinese.

METHODS

One hundred and forty-seven HAPE-p (HAPE patients) and 193 HAPE-r (HAPE resistants) were enrolled from the Yushu earthquake reconstruction workers in Qinghai province where the altitude is over 3 500 m above sea level. Blood samples were collected from each of the HAPE-p and HAPE-r groups. Information about physiological phenotypes was obtained via fieldwork investigation. The ACE-I/D polymorphism in HAPE-p and HAPE-r was detected by polymerase chain reaction (PCR).

RESULTS

The SaO2 was significantly lower while HR was significantly higher in HAPE-p group than those in HAPE-r group. The genotype frequencies of ACE-I/D for II, ID, DD in HAPE-r and HAPE-p groups were 0.430, 0.446, 0.124 and 0.435, 0.469, 0.095, respectively, the allelic frequencies of I and D were 0.650, 0.350 and 0.670, 0.330, respectively. The OR of ID, DD and D alleles relative to II for HAPE was 0.961 (0.610-1.514), 1.322 (0.634-2.758) and 1.080 (0.783-1.489). There was no significant difference of the genotypic and the allelic frequencies in ACE-I/D polymorphism between HAPE-p and HAPE-r groups.

CONCLUSIONS

There is no relation between ACE-I/D polymorphism and HAPE in the Han Chinese.

[Effect of different altitudes on telomere length of rat peripheral blood leukocyte]

The present study was aimed to investigate the effect of different altitudes on telomere length of rat peripheral blood leukocyte and possible mechanism. Sixty male rats were randomly divided into three groups, lower altitude control group (10 m), moderate altitude group (2 260 m) and very high altitude group (simulated 5 000 m). The moderate altitude group and very high altitude group rats were transported to Xining and hypobaric chamber in Qinghai University, respectively. The peripheral blood specimens were extracted 30 d after the transportation. By means of real-time PCR, automatic blood cell analyzer, ELISA, TBA and WST-1 methods, the telomere lengths of blood leukocyte, the hemoglobin (Hb) contents, the plasma levels of telomerase reverse transcriptase (TERT) and hypoxia-inducible factor 1α (HIF-1α), the plasma content of malondialdehyde (MDA) and superoxide dismutase (SOD) activity were measured, respectively. The results showed that the telomere lengths of peripheral blood leukocyte in moderate altitude group were longer than those in control group and very high altitude group. The changes of TERT were compatible with the telomere length of peripheral blood leukocyte under different altitudes. The levels of HIF-1α in moderate altitude group and very high altitude group were higher than that of control group. The very high altitude group showed decreased SOD activities and increased level of MDA, compared with the other two groups. These results suggest that the telomere lengths of rat peripheral blood leukocyte in moderate altitude are elongated, and that the telomere-elongating effect is lost under very high altitude. The changes of HIF-1α, TERT and oxidative stress damage are the main mechanisms of telomere length changes. Moderate altitude living might be beneficial to increasing the life span in mammals.

Sensory organs of the antenna of two Fannia species (Diptera: Fanniidae)

The latrine fly (Fannia scalaris) and lesser house fly (Fannia canicularis) are ubiquitous fanniid species of forensic and medical importance. The external morphology of sensilla on the antennae is studied using a stereoscopic microscope and scanning electron microscope, and the internal structure of the antennae is revealed by paraffin sections under the light microscope and laser scanning confocal microscope. Only grooved bristles are found on the scape and pedicel. Four major types of surface sensilla are found on the antennal funiculus and are classified as: (a) trichoid sensilla, (b) two subtypes of basiconic sensilla, (c) clavate sensilla, and (d) coeloconic sensilla. Density of each sensilla type of the two species is calculated. A remarkable difference is observed that the higher density of clavate sensilla occurs on the posteroventral surface in F. scalaris, whereas they are on the anterodorsal surface in F. canicularis. Several cuticular depressions that were previously known as "olfactory pits" are observed on the funiculus of both species. Combining with previous studies, they are suggested to be classified into two types: pit and sacculus. Pit is single-chambered and filled with one type of sensilla, whereas the sacculus is a multi-chambered pit organ containing several types of sensilla. Surprisingly, the pits observed in our study are mostly situated at the lateral region of the antennal funiculus, whereas in other flies, they are found on the posteroventral or anterodorsal surface of antennal funiculus. In addition, the sacculus found in our study houses only basiconic-like sensilla, which is remarkably different from other findings. Moreover, observation under light microscope indicates that previous data of the complexity and the number of the "olfactory pits," which are an important type of efficient sensory convergence, could be underestimated. Thus, more precise methods such as paraffin section or transmission electron microscope are suggested for further study.

Neurological adaptations to hypoxia in Tibetan antelope (Pantholops hodgsonii) with a view of molecular biology of respiratory globin-neuroglobin

Neuroglobin (Ngb) is a respiratory protein that is preferentially expressed in brain of mouse and man. In this article, Tibetan antelope, living at altitude of 3 000-5 000 m for millions of years, was selected as the model of hypoxia-tolerant adaptation species. Using reverse transcription polymerase chain reaction (RT-PCR) and Western blot techniques, expression of Ngb gene was amplified and analyzed in antelope brain tissue. Our results showed that Ngb homology protein in Tibetan antelope was identified with more sequence similarity with cattle (96%), sheep (95%), and human (95%). We detected that there were some mutations occurred in the Open Reading Frame of Ngb in Tibetan antelope compared with sheep. Phylogenetic analysis of Ngb chain showed that it was closer to cattle than the others. This study suggests possible roles of central nervous system enriched Ngb in adaptation of Tibetan antelope to extremely high altitude.

[Study on the content of myoglobin and the activity of lactate dehydrogenase and malate dehydrogenase in skeletal muscle of tibetan antelope]

OBJECTIVE

To explore the adaptive mechanism to hypoxia in skeletal muscle of tibetan antelope.

METHODS

Tibetan sheep which living at the same altitude (4 300 m) with tibetan antelope and low altitude (1 800 m) sheep as control, the content of myoglobin (Mb) and lactic acid (LA), the activity of lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) in skeletal muscles among three animals were analyzed by spectrophotometer.

RESULTS

The content of myoglobin in skeletal muscle of tibetan antelope significantly higher than that of tibetan sheep and low altitude sheep (P < 0.05). And the content of LA in skeletal muscle of tibetan antelope significantly lower than that of tibetan sheep and low altitude sheep (P < 0.05), activity of LDH and MDH in skeletal muscle was significantly lower and higher respectively than that of tibetan sheep and low altitude sheep (P < 0.05). There was no significant difference between tibetan sheep and low altitude sheep.

CONCLUSION

Tibetan antelope may improve their ability to get oxygen under hypoxia by increasing the content of myoglobin in skeletal muscle, and the proportion of aerobic metabolism is high in skeletal muscle, it may be relate that with high myoglobin content in skeletal muscle, we suppose that high myoglobin content in skeletal muscle of tibetan antelope might be one of the molecular basis to adapt hypoxia.

[Effect of high altitude hypoxia on the activity and protein expression of CYP2C9 and CYP2C19]

This study is to investigate the effect of high altitude hypoxia on the activity and protein expression of CYP2C9 and CYP2C19. Rats from plain (P) and rats with acute middle altitude hypoxia (AMH), chronic middle altitude hypoxia (CMH), acute high altitude hypoxia (AHH) and chronic high altitude hypoxia (CHH) were administered orally phenytoin sodium (PHT) and omeprazole (OMZ) to evaluate the activity of CYP2C9 and CYP2C19, separately. The serum concentrations of PHT and metabolite 4'-hydroxyphenytoin (HPPH) at 12 h after treatment and the serum concentrations of OMZ and metabolite 5-hydroxy omeprazole (5-OHOMZ) at 3 h after treatment were determined by RP-HPLC. The activity of CYP2C9 and CYP2C19 was evaluated by the ratio of HPPH to PHT and the ratio of 5-OHOMZ to OMZ, respectively. The protein expressions of CYP2C9 and CYP2C19 were determined by ELISA method. The activities of CYP2C9 (HPPH/PHT) in P, AMH, CMH, AHH and CHH were 0.67 +/- 0.31, 0.75 +/- 0.29, 0.76 +/- 0.23, 0.79 +/- 0.31 and 0.75 +/- 0.18, respectively, and the activities of CYP2C19 (5-OHOMZ/OMZ) in P, AMH, CMH, AHH and CHH were 0.17 +/- 0.06, 0.20 +/- 0.10, 0.11 +/- 0.05, 0.37 +/- 0.13 and 0.19 +/- 0.05, respectively. The protein expressions of CYP2C9 in P, AMH, CMH, AHH and CHH were 4.20 +/- 1.27, 3.95 +/- 0.81, 3.93 +/- 1.11, 4.32 +/- 1.03 and 4.12 +/- 0.86 ng x g(-1), respectively, and the protein expressions of CYP2C19 in P, AMH, CMH, AHH and CHH were 3.91 +/- 1.82, 3.63 +/- 2.07, 2.55 +/- 0.85, 4.78 +/- 2.37 and 3.51 +/- 1.03 ng x g(-1), respectively. The activities and protein expressions of CYP2C9 in AMH, CMH, AHH and CHH were not significantly different with those of P. The protein expressions of CYP2C19 in AMH, CMH, AHH and CHH were not significantly different with those of P, but the activity of CYP2C19 in AHH was significantly higher than that of P. This study found significant changes in the activity of CYP2C19 under the special environment of acute high altitude hypoxia.

[Genetic cloning and expression of hypoxia inducible factor 1 alpha in high altitude hypoxic adaptation species Tibetan antelope (Pantholops hodgsonii)]

In order to investigate the role of the hypoxia inducible factor 1 alpha (HIF-1α) in the adaptation mechanism to high altitude hypoxia, the cloning of the HIF-1α gene cDNA of Tibetan antelope (Pantholops hodgsonii), using RT-PCR and RACE, was applied, and the comparative analysis of the tissue-specific expressions of HIF-1α among Tibetan antelope, Tibetan sheep and plain sheep was performed using real-time PCR and Western blot. The sequence analysis indicated that the cDNA sequences acquired by cloning from the HIF-1α gene of Tibetan antelope comprised a 2 471-bp open reading frame (ORF) and a 1 911-bp 3'UTR. The similarity between its coding sequence, predicted amino acid sequence and HIF-1α of other mammals exceeded 87%, in which the similarity with cow was up to more than 98%, which showed that this sequence was the cDNA of HIF-1α of Tibetan antelope. The results of real-time PCR and Western blot showed that expressions of HIF-1α mRNA and protein appeared in Tibetan antelope's lung, cardiac muscle and skeletal muscle, with the highest expression in lung. HIF-1α mRNA and protein had obvious differential expression in these tissues. Further research showed that Tibetan antelope and Tibetan sheep possessed higher expressions of HIF-1α protein in the three tissues above-mentioned compared with plain sheep, and the expressions of HIF-1α mRNA and protein in Tibetan antelope's lung, cardiac muscle and skeletal muscle were higher than those of Tibetan sheep. It illustrates that the hypoxic HIF-1α-specific expression is one of the molecular bases of high altitude hypoxia adaptation in Tibetan antelope.

[Comparisons of endocrine hormones levels between Tibetan antelope and Tibetan sheep]

The Tibetan antelope, a prototype mammal, has developed a unique adaptation to extreme high altitude-associated hypoxia. To investigate the role of the endocrine system in adaptation to high altitude in the Tibetan antelope, comparisons of endocrine hormones levels between Tibetan antelope (n = 9) and Tibetan sheep (n = 10) were performed. Both two kinds of animals were captured at an altitude of 4 300 m and then transported to experimental base at 2 800 m altitude. The blood samples were drawn from right external jugular vein in the next morning, and the 20 hormones in hypothalamus-adenohypophysis-peripheral hormonal axis were measured with radioimmunoassay or enzyme-linked immunosorbent assay. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean pulmonary arterial pressure (mPAP) were recorded using catheterization. Moreover, hemoglobin (Hb) content was measured by blood analyser. The results showed that, the levels of FT(3), FT(4) and Ang II in Tibetan antelope were significantly lower than those in Tibetan sheep, whereas TRH, CRH, GHRH, F, E(2), Ald, ACTH and CGRP levels were significantly greater in Tibetan antelope than those in the Tibetan sheep. Compared with Tibetan sheep, Tibetan antelope showed lower HR, mPAP, SBP, DBP and Hb content. In Tibetan antelope and Tibetan sheep, both Hb and Ang II were correlated positively with respective mPAP. In Tibetan antelope, FT(3) level was correlated positively with GH and negatively with ACTH. These results suggest that the endocrine system of Tibetan antelope is characterized by low energy expenditure and high stress, which may be one of the mechanisms underlying the Tibetan antelope adaptation to chronic hypoxia.

Comparison of anastomotic leakage and stricture formation following layered and stapler oesophagogastric anastomosis for cancer: a prospective randomized controlled trial

The objective of this prospective, randomized, controlled trial, conducted from May 2002 to December 2007, was to compare post-operative anastomotic leakage and stricture formation following layered manual versus stapler oesophagogastric anastomosis in patients who underwent resection of oesophageal or gastric cardia carcinoma. Patients (n = 516) were randomized to receive either layered manual or circular stapled oesophagogastric anastomosis. Mean follow-up time was > 12 months. Anastomotic leakage occurred in one (0.4%) patient in the layered group and six (2.2%) in the stapler group; no statistically significant between-group difference. After operation, two (0.8%) patients in the layered group and 13 (5.0%) in the stapler group developed a benign oesophageal stricture; the difference between the groups was statistically significant. Compared with stapler anastomosis, layered manual anastomosis may significantly reduce the incidence of anastomotic strictures. This method is easy to apply and could be used as an alternative procedure for oesophagogastric anastomosis after resection for oesophageal or cardia carcinoma.

A mitochondrial genome sequence of the Tibetan antelope (Pantholops hodgsonii)

To investigate genetic mechanisms of high altitude adaptations of native mammals on the Tibetan Plateau, we compared mitochondrial sequences of the endangered Pantholops hodgsonii with its lowland distant relatives Ovis aries and Capra hircus, as well as other mammals. The complete mitochondrial genome of P. hodgsonii (16,498 bp) revealed a similar gene order as of other mammals. Because of tandem duplications, the control region of P. hodgsonii mitochondrial genome is shorter than those of O. aries and C. hircus, but longer than those of Bos species. Phylogenetic analysis based on alignments of the entire cytochrome b genes suggested that P. hodgsonii is more closely related to O. aries and C. hircus, rather than to species of the Antilopinae subfamily. The estimated divergence time between P. hodgsonii and O. aries is about 2.25 million years ago. Further analysis on natural selection indicated that the COXI (cytochrome c oxidase subunit I) gene was under positive selection in P. hodgsonii and Bos grunniens. Considering the same climates and environments shared by these two mammalian species, we proposed that the mitochondrial COXI gene is probably relevant for these native mammals to adapt the high altitude environment unique to the Tibetan Plateau.

Human ABCA1 BAC transgenic mice show increased high density lipoprotein cholesterol and ApoAI-dependent efflux stimulated by an internal promoter containing liver X receptor response elements in intron 1

By using BAC transgenic mice, we have shown that increased human ABCA1 protein expression results in a significant increase in cholesterol efflux in different tissues and marked elevation in high density lipoprotein (HDL)-cholesterol levels associated with increases in apoAI and apoAII. Three novel ABCA1 transcripts containing three different transcription initiation sites that utilize sequences in intron 1 have been identified. In BAC transgenic mice there is an increased expression of ABCA1 protein, but the distribution of the ABCA1 product in different cells remains similar to wild type mice. An internal promoter in human intron 1 containing liver X response elements is functional in vivo and directly contributes to regulation of the human ABCA1 gene in multiple tissues and to raised HDL cholesterol, apoAI, and apoAII levels. A highly significant relationship between raised protein levels, increased efflux, and level of HDL elevation is evident. These data provide proof of the principle that increased human ABCA1 efflux activity is associated with an increase in HDL levels in vivo.

Characterization and localization of human type10 17beta-hydroxysteroid dehydrogenase

The tissue distribution, subcellular localization, and metabolic functions of human 17beta-hydroxysteroid dehydrogenase type 10/short chain L-3-hydroxyacyl-CoA dehydrogenase have been investigated. Human liver and gonads are abundant in this enzyme, but it is present in only negligible amounts in skeletal muscle. Its N-terminal sequence is a mitochondrial targeting sequence, but is not required for directing this protein to mitochondria. Immunocytochemical studies demonstrate that this protein, which has been referred to as ER-associated amyloid beta-binding protein (ERAB), is not detectable in the ER of normal tissues. We have established that protocols employed to investigate the subcellular distribution of ERAB yield ER fractions rich in mitochondria. Mitochondria-associated membrane fractions believed to be ER fractions were employed in ERAB/Abeta-binding alcohol dehydrogenase studies. The present studies establish that in normal tissues this protein is located in mitochondria. This feature distinguishes it from all known 17beta-hydroxysteroid dehydrogenases, and endows mitochondria with the capability of modulating intracellular levels of the active forms of sex steroids.

Surface modification of titanium through amino group implantation

We modified Ti surfaces by implantation of amino (NH(2+)) groups at 10(16) and 10(17) cm(-2). The implanted surfaces were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning Auger electron spectroscopy (AES), and second ion mass spectroscopy (SIMS). The experimental results showed that the implanted Ti specimens were covered by a dominant hydrocarbon overlayer due to contamination and the surface oxide layer of implanted specimens became thicker. XPS, AES, and SIMS depth profiles showed that implanted elements had a typical ion implantation distribution and that titanium nitride (TiN) was formed.