Magnetotactic bacteria can orient and migrate along ambient geomagnetic field lines because of their intracellular magnetic particles ( referred as magnetosomes) , which comprise nanometer-sized, membrane-bound crystals of the magnetic iron minerals. Magnetosome formation is a mineralization process with very strict biological controls over the accumulation, transportation and nucleation in the cell. This paper describes the current progresses of magnetosome formation and the function of proteins involved in this biomineralization process.

Objective To learn the present status of defluoridation water improvement project in Shanxi province in order to provide scientific basis for speeding up the prevention and control of endemic fluorosis.Methods According to "The National Technical Scheme for Endemic Disease Control" from 2005 to 2009, the investigation points were selected in the counties that implemented the measures of water improvement and defluoridation,the status of drinking water defluoridation Project was investigated, and the water fluoride levels were determined by fluoride selective ion electrode. Results The primary status was surveyed in 1658 water improvement and defluoridation projects in 51 counties. The resource of drinking water for water improvement and defluoridation projects was mostly ground water[accounting for 93.12% (1544/1658)]. Among 1658 water improvement and defluoridation projects 1405 projects worked well(accounting for 84.74%) and 190 projects intermittently worked (accounting for 11.46%). Sixty three projects abandoned (accounting for 3.80%), in Datong basin the abandoned projects accounted for 36.36% (12/33). Water fluoride content of 1595 water improvement and defluoridation projects had been determined, among them water fluoride content of 874 projects were above 1.0 mg/L (accounting for 54.80%). The situations of exceeded national standard in the five basins was different(H = 33.22,P ＜ 0.01). The rate of over national standard of fluoride levels in drinking water was 88.37%(38/43) in Datong basin. Therefore, in Datong basin water improvement should be strengthened. Conclusions In Shanxi province the water improvement and defluoridation projects are basically running normally. However, the qualified rate is lower for the water improvement and defluoridation projects. The water improvement status varies dramatically among areas.The situation is still grim in Shanxi province. Water improvement and defluoridation needs to be strengthened to improve the effect of prevention and control of the disease.

Aim To investigate whether necroptosis mediates chemical hypoxia-induced HT22 mouse hippocampal cell injury and inflammation.Methods HT22 hippocampal cells were exposed to cobalt chloride (CoCl2) to establish a model of the chemical hypoxia-induced injury and inflammation.The expression level of RIP3 (an index of necroptosis) was determined by Western blot.Cell counter kit-8 (CCK-8) assay was used to test the cell viability.Lactate dehydrogenase (LDH) activity in the culture medium was measured with commercial kits.Mitochondrial membrane potential (MMP) was examined by rhodamine123 staining followed by photofluorography.The intracellular level of reactive oxygen species (ROS) was detected by 2', 7'-dichlorfluorescein-diacetate (DCFH-DA) staining followed by photofluorography.The secretion levels of interleukin-1β (IL-1β) and tumor necrosis factor-a (TNF-α) were measured by ELISA.Results Treatment of HT22 hippocampal cells with 600 μmol·L-1 CoCl2 for 36 h markedly induced cytotoxicity, leading to a decrease in cell viability to (52.0±2.65) % , indicating that chemical hypoxia-induced cellular injury model was successfully set up.Besides, CoCl2 induced considerable injuries and inflammation, evidenced by increases in LDH activity, ROS production, MMP loss, as well as the secretion levels of IL-1β and TNF-α.Co-treatment of the cells with 40~100 μmol·L-1 Nec-1 (a specific inhibitor of necroptosis) and CoCl2 markedly attenuated the decrease in viability induced by CoCl2, reaching the best anti-cytotoxicity inhibitory effect at 80 μmol·L-1.Meanwhile, the co-treatment with 80 μmol·L-1 Nec-1 blocked the above injuries and inflammatory response induced by CoCl2.In addition, treatment of HT22 hippocampal cells for 6~48 h up-regulated the expression of RIP3, and Nec-1 alleviated the up-regulation of RIP3 expression level induced by CoCl2.Conclusion Necroptosis mediates chemical hypoxia-induced HT22 hippocampal cell injury and inflammation.

OBJECTIVETo evaluate the clinical outcome of accessory navicular fusion for treatment of the painful accessory navicular bone of type II in adults.

METHODSFrom June 2006 to June 2012, a total of 38 feet (in 35 adult patients) with painful accessory navicular with type I underwent an fusion operation of the primary and accessory navicular bones,including 26 males and 9 females with a mean age of (32.4±7.3) years old ranging from 18 to 44 years old. The course of disease ranged from 3 to 10 months. The perioperative complications and radiological outcomes were observed and recorded. The foot function before and after operation were assessed by the American Orthopedic Foot and Ankle Society (AOFAS) midfoot score, and the easement of the pain was evaluated by visual analog score (VAS).

RESULTSTwo patients had transient superficial inflammation of the incision, no obvious perioperative complications occurred. All patients were follow-up for (53.5±14.7) months (12 to 84 months). Bone union was confirmed on plain radiography in 32 cases (35 feet). The mean time from the operation to union was (13.7±2.3) weeks (9 to 18 weeks). Postoperative pain VAS score was improved obviosly than preoperative (V=12.14,P< 0.01). The talar-to-first metatarsal angle [(9.4±3.5)° vs (8.3±2.7)°, t=0.736, P>0.05)], calcaneal tilt angle [(17.7±2.2)° vs (18.9±3.4)°, t=0.794, P>0.05],talonavicular uncoverage angle [(14.3±3.4)° vs(12.5?4.6)°,t=0.947, P>0.05) ],and height of the first tarsometatarsal joint [(14.8±3.1) mm vs (15.9±2.8) mm,t=0.814,P>0.05)] before and after operations had no statistic difference. The AOFAS midfoot score was improced from preoperative 45.6±5.3 to postoperative 82.5±7.4 (t=3.214,P< 0.01).

CONCLUSIONFor the painful accessory navicular bone of type II in adults, if the patient has a large navicular bone and not complicated with rigid flatfoot, once the conservative treatment fails, fusion of the primary and accessory naviculars may be a successful intervention. Overall, the procedure provides reliable pain relief, definite foot function improvement, and good patient satisfaction.

Adolescent ; Adult ; Female ; Follow-Up Studies ; Foot Diseases ; physiopathology ; surgery ; Humans ; Male ; Tarsal Bones ; abnormalities ; physiopathology ; surgery ; Treatment Outcome ; Young Adult

Objective To observe the long term effects of arthroscopic knee debridement and reconstructing operation for treating osteoarthritis in patients with Kaschin-Beck disease. Methods Thirty-one cases of patients with Kaschin-Beck disease were followed for 6 years after operation of articular clearing by arthroscope. Index of pain, symptoms of self-evaluation, range of motion, walking distance, standing test by affected leg when bending at 30° or 60° were recorded and compared with the preoperative results. Results Twenty-four cases were followed up for 6 years. Six years after operation the pain index(3.38 ± 2.87) was dramatically decreased compared to that before operation (6.88 ± 1.45, t = 5.30, P ＜ 0.05). Patients symptoms markedly improved by subjective self-evaluation was 70.83% (17/24), the effective rate was 100% (24/24). The number of cases that could stand up when leg bending at 30° or 60° were 21,18 cases, respectively, compared with that of preoperative of 14, 11 cases, respectively, the difference was statistically significant(x2 = 5.17,4.27, all P ＜ 0.05). Six years after operation the walking distance(3 cases ＜ 1 km, 11 cases 1 - 5 km and 10 cases ＞ 5 km) were greatly improved compared to the results before operation (12 cases ＜ 1 km, 9 cases 1 - 5 km and 3 cases ＞ 5 km, U = 2.88, P ＜0.05). Six years after operation the knee activity[(132.25 ± 14.52)°] remained at the same level, compared with that of preoperative [(131 .58 ± 14.68) °], the difference was not statistically significant (t = 0.16, P ＞ 0.05) .Conclusions The method of arthroscopic joint debridement to cure Kaschin-Beck disease knee osteoarthritis can significantly reduce pain, improve function and walking distance, with more stable long-term satisfactory outcome.

Objective To improve the recognition of nervous system symptoms of inborn errors.Methods Five patients with organic acidemias were screened by urine organic acid analysis(gas chromotography-mass spectrometry,GC/MS),3 cases of methylmalolic acidemias(MMA) and 2 cases of propionic acidemias(PA) were confirmed.They were treated with special diet and medicine after diagnosis.Result The improvement of mental development was observed after treatment.Conclusions Most of organic acidemias involve nervous systems,causing non-specific symptoms of nervous system as lethergy,seizures,mental retardation.Inborn errors of metabolism shall be kept in mind when causes of the symtoms of acidosis,seisures,mental retardation and lethergy are investigated.GC/MS is a very important method in diagnosis of organic acidemias.Early diagnosis and early treatment can improve the mental prognosis.

Objective To observe the changes of expressions of glucose transporter 1,3 gene(GLUT1 mRNA and GLUT3 mRNA) in hippocampus after hypoxic-ischemic brain damage in newborn rats and effects of progesterone on them.Methods Forty SD rats(7-day-old) were divided randomly into 4 groups:normal group,sham operation group,hypoxic-ischemic group and progesterone group.Rats were subjected to right common carotid artery ligation and exposed to 80 mL/L oxygen and 920 mL/L nitrogen gas for 2 hours to establish hypoxic-ischemic model in hypoxic-ischemic group and progesterone group.The rats in sham operation group only received right common carotid artery ligation.Progesterone(8 mg/kg) or sesame oil(of same volume) was given intraperitonealy in progesterone group or other groups 30 minutes before operation.All rats were killed 24 hours after operations.The expressions of GLUT1 mRNA and GLUT3 mRNA in hippocampus of rats in every group were assessed by adopting RT-PCR technique.Results The expressions of GLUT1 mRNA and GLUT3 mRNA in the hypoxic-ischemic group(0.674?0.083,0.785?0.093) increased markedly compared with those in sham operated group(0.374?0.061,0.519?0.060)(Pa0.05).Conclusions Progesterone maintain the energy supply of the brain by up-regulating the expression of GLUT1 mRNA and GLUT3 mRNA and accelerating the transportation of glucose into brain,which may be one of the protective mechanisms.

Objective To develop a candidate reference method for the measurement of progesterone in human serum.Methods The serum sample is mixed with the internal standard [3,4-~(13)C_2] progesterone.After extraction with n-hexane and purified by a aqueous solution of 2-Hydroxypropyl-?- cyclodextrin (HP-?-CD),the serum progesterone and labeled progesterone are converted to the 3-enol heptafluorobutyrate and analyzed by gas chromatography mass spectrometry (GC/MS) with selected ion monitoring.The concentration of serum progesterone is calculated by bracketing method.Results The results gave coefficients of variation (CVs) of 0.69% to 2.12%.The analytical recoveries ranged from 98.3% to 100.1%.The results of measuring certified reference materials of serum progesterone are agree with the target value.Conclusion The procedure for measuring progesterone in serum is a highly accurate and precise method and may be used as a candidate reference method for serum progesterone assays.

The selective side-chain cleavage of phytosterol to 4-androstene-3,17-dione(4-AD)and 1,4-androstadiene-3,17-dione(ADD)by Mycobacterium sp.was described.Because of the similarity in chemical structure between 4-AD and ADD,it is difficult to separate them from the fermentation broth.So far,it has been verified that the ADD can be produced by dehydrogenation of 4-AD.In this reaction,3-Ketosteriod-1-Dehydrogenase(ksdD)plays an important role.The gene knocking out method was used to solve the problem.Partial sequence of ksdD was obtained by PCR which was 631bp in length.Then,a targeting vector pUC19-MK was constructed,which was electroporate into the original strain Mycobacterium neoauru.The method of homologous recombination was used to knock out ksdD gene located in the chromosome of Mycobacterium neoauru.In this way,ksdD would lose its enzyme activity.In the result,5 transformants were screened.The experiments of steroid transformation by the transformants were carried out.The productivity of 4-AD reached 17.52% after 144h,which is 192% higher than the original strain.Meanwhile,the productivity of ADD reached 6.12%,which is 89.9% lower than the original strain.

OBJECTIVETo study the roles of platelet (PLT) and its regulating factors, megakaryocyte, thrombopoietin (TPO) and transforming growth factor beta1 (TGF-beta1), in immune vasculitis in young rabbits.

METHODSAn experimental model of Kawasaki disease (KD) of weanling rabbits was reproduced by bovine serum. PLT count, total number and differentiating count of megakaryocyte, and serum TPO and TGF-beta1 levels were measured 0, 4, 8, 12, 16, 20, 24 and 28 days after KD induction. Pathological analysis of coronary artery, liver, spleen, kidney and brain was performed 17 and 28 days after KD induction.

RESULTSIn the KD group, PLT count, the total number of megakaryocyte, and the middle board megakaryocyte percentage increased 12, 16, 20, 24 and 28 days; serum TPO level increased 8, 12, 16, 20, 24 and 28 days; serum TGF-beta1 level increased 16, 20, 24 and 28 days after KD induction compared with those in the normal control group (p<0.05). The pathological examinations of coronary artery, liver, spleen, kidney and brain showed severe inflammatory injuries of tiny arteries and small/medium-sized arteries 17 and 28 days after KD induction, respectively in the KD group. The aortas were showed as mild inflammatory injuries.

CONCLUSIONSPLT, megakaryocyte, TPO and TGF-beta1 participate in the pathogenesis of KD, and they may play an important role in the injuries of immune vasculitis. This suggests that they may serve as markers for the assessment of severity in KD.

Animals ; Blood Platelets ; physiology ; Disease Models, Animal ; Humans ; Megakaryocytes ; physiology ; Mucocutaneous Lymph Node Syndrome ; etiology ; Rabbits ; Thrombopoietin ; physiology ; Transforming Growth Factor beta1 ; physiology ; Vasculitis ; etiology ; immunology ; pathology