Objective To develop a human immune-deficiency virus (HIV) infection risk appraisal model suitable for men who has sex with men (MSM) in Guangzhou,and to provide tools for follow-up the outcomes on health education and behavior intervention.Methods A cros-sectional study was conducted in Guangzhou from 2008 to 2010.Based on the HIV surveillance data,the main risk factors of HIV infection among MSM were screened by means of logistic regression.Degree on relative risk was transformed into risk scores by adopting the statistics models.Individual risk scores,group risk scores and individual infection risk in comparison with usual MSM groups could then be calculated according to the rate of exposure on those risk factors appeared in data from the surveillance programs.Results Risk factors related to HIV infection among MSM and the quantitative assessment standard (risk scores and risk scores table of population groups) for those factors were set up by multiple logistic regression,including age,location of registered residence,monthly income,major location for finding their sexual partners,HIV testing in the past year,age when having the first sexual intercourse,rate of condom use in the past six months,symptoms related to sexually transmitted diseases (STDs) and syphilis in particular.The average risk score of population was 6.06,with risk scores for HIV positive and negative as 3.10 and 18.08 respectively (P＜ 0.001 ).The rates of H IV infection for different score groups were 0.9％,2.0％,7.0％,14.4％ and 33.3％,respectively.The sensitivity and specificity on the prediction of scores were 54.4％ and 75.4％ respectively,with the accuracy rate as 74.2％.Conclusion HIV infection risk model could be used to quantify and classify the individual' s infectious status and related factors among MSM more directly and effectively,so as to help the individuals to identify their high-risk behaviors as well as lifestyles.We felt that it could also serve as an important tool used for personalized HIV health education and behavior intervention programs.

OBJECTIVETo study the relationship between occupational hazard susceptibility of formaldehyde and genetic polymorphisms of ALDH2 and CYP2E1.

METHODSGenotypes of ALDH2 and CYP2E1 (Rsa I/Pst I site) of 107 subjects exposed to formaldehyde were determined with PCR-RFLP through testing peripheral blood lymphocytes, and the concentration of air formaldehyde in workplace and urine formic acid of the subjects were measured with HPLC. The relationship between genotypes and the urine formic acid increment was analyzed with nonparametric rank sum testing.

RESULTSThe concentration of urine formic acid increment was related with ALDH2 genotypes (chi2 = 9.241, P < 0.05), and the means of urinary formic acid of subjects with GG, GA, AA genotype were (15.84 +/- 6.86), (12.06 +/- 7.94) and (7.31 +/- 5.37) mg/g creatinine, respectively. Mann-Whitney U test showed the formic acid increment between allele G homozygotes and allele A homozygotes was significantly different (U=26, P= 0.033). Our data indicated that the formaldehyde metabolism of ALDH2 GG homozygotic genotype was more active than ALDH2 AA homozygotic genotype(the difference of the two mean rank was 13.30). But the polymorphism of Rsa I / Pst I site of CYP2E1 5'-franking region was not correlated with the concentration of urine formic acid (chi2 = 4.285, P=0.117), and the urinary formic acid means of subjects with C1/C1, C1/C2, C2/C2 genotype were (11.14 +/- 7.91), (12.13 +/- 8.16) and (16.51 -/+ 3.78) mg/g creatinine, respectively. By Stepwise Multiple Regression Analysis, it showed that the urinary formic acid increment might be influenced by FA exposure concentration and ALDH2 genotype, and the model's R2 was 0.196.

CONCLUSIONThe metabolism of formaldehyde in human body was related with the genotypes of ALDH2, but not with the CYP2E1 (Rsa I/Pst I) polymorphisms.

Adolescent ; Adult ; Aldehyde Dehydrogenase ; genetics ; Aldehyde Dehydrogenase, Mitochondrial ; Alleles ; Cytochrome P-450 CYP2E1 ; genetics ; Disease Susceptibility ; Female ; Formaldehyde ; metabolism ; Gene Frequency ; Genotype ; Humans ; Male ; Occupational Exposure ; Polymorphism, Genetic ; Risk Factors

BACKGROUNDAbout 50% - 70% of patients with Chiari malformation I (CMI) presented with syringomyelia (SM), which is supposed to be related to abnormal cerebrospinal fluid (CSF) flow around the foramen magnum. The aim of this study was to investigate the cerebrospinal fluid dynamics at levels of the aqueduct and upper cervical spine in patients with CMI associated with SM, and to discuss the possible mechanism of formation of SM.

METHODSFrom January to April 2004, we examined 10 adult patients with symptomatic CMI associated with SM and 10 healthy volunteers by phase-contrast MRI. CSF flow patterns were evaluated at seven regions of interest (ROI): the aqueduct and ventral and dorsal subarachnoid spaces of the spine at levels of the cerebellar tonsil, C2 - 3, and C5 - 6. The CSF flow waveforms were analyzed by measuring CSF circulation time, durations and maximum velocities of cranial- and caudal-directed flows, and the ratio between the two maximum velocities. Data were analyzed by t test using SPSS 11.5.

RESULTSWe found no definite communication between the fourth ventricle and syringomyelia by MRI in the 10 patients. In both the groups, we observed cranial-directed flow of CSF in the early cardiac systolic phase, which changed the direction from cranial to caudal from the middle systolic phase to the early diastolic phase, and then turned back in cranial direction in the late diastolic phase. The CSF flow disappeared at the dorsal ROI at the level of C2 - 3 in 3 patients and 1 volunteer, and at the level of C5 - 6 in 6 patients and 3 volunteers. The durations of CSF circulation at all the ROIs were significantly shorter in the patients than those in the healthy volunteers (P = 0.014 at the midbrain aqueduct, P = 0.019 at the inferior margin of the cerebellar tonsil, P = 0.014 at the level of C2 - 3, and P = 0.022 at the level of C5 - 6). No significant difference existed between the two groups in the initial point and duration of the caudal-directed CSF flow during a cardiac cycle at all the ROIs. The maximum velocities of both cranial- and caudal-directed CSF flows were significantly higher in the patients than those in the volunteers at the aqueduct (P = 0.018 and P = 0.007) and ventral ROI at the inferior margin of the cerebellar tonsil (P < 0.001 and P = 0.002), as so did the maximum velocities of the caudal-directed flow in the ventral and dorsal ROIs at the level of C2 - 3 (P = 0.004; P = 0.007).

CONCLUSIONSThe direction of CSF flow changes in accordance with cardiac cycle. The syringomyelia in patients with CMI may be due to the decreased circulation time and abnormal dynamics of the CSF in the upper cervical segment. The decompression of the foramen magnum with dural plasty is an alternative for patients with CMI associated with SM.

Adolescent ; Adult ; Arnold-Chiari Malformation ; cerebrospinal fluid ; complications ; diagnosis ; Electrocardiography ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Syringomyelia ; etiology

This study was aimed to create strontium-calcium sulfate compounds for making a new bioactive material with osteoconductive and osteoinduceable activity for bone repairing. Its mechanics and degradation features were assessed in vitro. Powders of alpha-calcium sulfate hemihydrate (alpha-CSH) and SrCl2 were mixed completely to make Sr-calcium sulfate compounds materials with 6 different concentrations (0%, 0.1%, 0.3%, 0.5%, 1% and 2%) of Sr. Scanning electron microscope was used to observe the configuration of the new materials. The compressive strength of each material was tested. The materials were soaked into simulated body fluid (SBF) to test the features of degradation, which included pH, weight loss, declination of compressive strength and the changes of strontium ion concentration. The crystal appearances were influenced by incorporating of strontium. The compressive strength of non-strontium incorporating calcium sulfate was 36.65 +/- 2.22 MPa. When the concentration of strontium was increasing, the compressive strength measurements of the materials tended to decline. The compressive strength declined to 20.56 +/- 2.64 MPa when the strontium concentration reached to 2%. The pH value of the SBF declined when the time of degradation increased, but both of them were very stable. All of the materials got weight loss after being soaked in SBF for several weeks. The weight loss was slight within 4 weeks and it became dramatic after 4 weeks. When the concentration of strontium was increasing, the weight loss became more rapid and significant (P<0.05). During 0-4 weeks' degradation in SBF, the materials' compressive strength decreased much slower when the strontium concentration was below 0.5%; however, when the decrement of strength became faster, the strontium concentration became higher. The concentration of strontium ion in SBF began to increase faster after 4 weeks' soaking in SBF. As the concentration of strontium was increasing, the strontium ion concentration in SBF became higher (P = 0.000). The new compound materials made by the mixing of alpha-calcium sulfate hemihydrate and SrCl2 can provide efficient compressive strength. The features of degradation of the materials are very stable. The new materials can release lots of bone inducible substance-strontium ions to repair bone defection after 4 weeks of degradation.
Bone Substitutes ; chemical synthesis ; chemistry ; Calcium Sulfate ; chemistry ; Compressive Strength ; Humans ; Osteogenesis ; Strontium ; chemistry

Apoptosis ; drug effects ; Carcinoma, Hepatocellular ; pathology ; Cell Line, Tumor ; Doxorubicin ; pharmacology ; Hepatocytes ; cytology ; drug effects ; Humans ; Trans-Activators ; genetics

Bariatric Surgery ; methods ; Embolization, Therapeutic ; methods ; Ghrelin ; blood ; Humans ; Obesity ; blood ; surgery ; therapy

Objective To probe into the characteristics of traumatic effect of blast underpressure (BUP) on tympanic membrane and ossicular chain of guinea pigs exposed to blast underpressure. Methods The guinea pigs were exposed to experimental BUP generated by the underpressure generator and their tympanic membranes and auditory ossicules were observed with stereo-microscope.Results Most of the tympanic membranes in 72 guinea pigs (141 ears) presented with traumatic changes,such as engorgement,haemorrhage,epidermic desquamation and perforation,combined with fracture of ossicles in some guinea pigs.The traumatic severity of the tympanic membranes and auditory ossicules was related to the peak and the declinating duration of BUP.The minimum peak of the underpressure inducing perfo- ration was between-22.4kPa and-23.9kPa and the minimum peak inducing perforation of all the tym- panic membranes was between-83.1kPa and-87.2kPa.Conclusion The tympanic membrane in guinea pigs exposed to BUP changed traumatically,such as engorgement,haemorrhage,epidermic des- quamation,perforation and fracture of ossicles.The traumatic severity of the tympanic membranes and au- ditory ossicules is related to the peak and declinating duration of BUP.

Cell Line, Tumor ; DNA Repair ; DNA Repair Enzymes ; Hep G2 Cells ; Humans

BACKGROUNDThere are few researches for the healing of metaphyseal fractures; moreover, the animal models to study the metaphyseal fractures are usually made by the oscillating saw osteotomy without reliable fixation, which is not in accordance with our current clinical practice. In this study, we established a new model to observe the healing process of metaphyseal fractures.

METHODSEighteen New Zealand rabbits were used in the study. The fracture model was created by splitting the medial tibial plateau in rabbits, then reset, and fixed with compression screws. At 1, 2, 3, 4, 6, and 8 weeks postoperatively, the tibial specimens were collected; firstly, a general observation and an X-ray examination of the specimens was done, and then they were embedded in methylmethacrylate and cut into sections with hard tissue slicer. The sections were stained with Giemsa reagent and examined under light microscopy.

RESULTSThere was no fracture displacement in the tibial specimens of all time points, except for one showing a collapse. No external callus formation could be observed by X-ray and general examination. After 1 week of the operation, the fracture gap was filled by mesenchymal tissue; 2 weeks postoperatively, a large number of woven bones were formed; from the third week onwards, the woven bone began to turn into lamellar bone, and new trabecular structure began to form. In all of the slices, no obvious chondrocytes formed in fracture areas; thus, there was no endochondral ossification.

CONCLUSIONSThis model was an ideal fracture animal model and suitable for the study of metaphyseal fracture healing. The X-ray and histological images demonstrated that metaphyseal fracture healing was a process of direct bone healing through intramembranous bone formation under the conditions of minor trauma, good reduction, and firm fixation.

Animals ; Fracture Healing ; physiology ; Fractures, Bone ; diagnostic imaging ; pathology ; Rabbits ; Radiography

Objective:To examine the effects of in-house made heat preservation socks on body temperature maintenance in elderly patients undergoing posterior approach spinal surgery.Methods:This was a randomized, controlled trial.A total of 84 patients aged 65-75 years treated with posterior approach spinal surgery under general anesthesia were enrolled.Patients were randomly divided into two groups: the experimental group(n=42)and the control group(n=42). The two groups were treated with the same anesthesia procedure.The control group was given routine temperature management, while the experimental group used in-house made heat preservation socks in addition to routine temperature management during the entire surgical process.The anal temperature of patients was dynamically monitored with a disposable body temperature probe, and body temperature, heart rate, mean arterial pressure and oxygen saturation were recorded at the time of anesthesia induction and intubation(T 0), skin incision(T 1), 1 hour into surgery(T 2), 2 hours into surgery(T 3), the end of surgery(T 4), arrival at the post-anesthesia care unit(T 5), immediately after extubation(T 6)and 1 hour after extubation(T 7). The occurrence of intraoperative body temperature lower than 36℃, postoperative extubation time, incidence of shivering, postoperative incision infection rate and average length of stay were recorded.Changes in C-reactive protein and procalctonin levels were recorded. Results:There was no significant difference in sex composition, age, height, weight, body mass index and operative time between the two groups(all P>0.05). From T 2 to T 7, the body temperature of the experimental group was higher than that of the control group[T 2: (36.5±0.5)℃ vs.(36.3±0.3)℃, (36.6±0.6)℃ vs.(36.2±0.4)℃, (36.6±0.6)℃ vs.(36.2±0.4)℃, (36.6±0.6)℃ vs.(36.2±0.4)℃, (36.6±0.6)℃ vs.(36.2±0.4)℃, (36.6±0.5)℃ vs.(36.2±0.3)℃, t=2.229, 3.514, 3.823, 3.790, 3.722, 4.408, P=0.029, 0.001, 0.001, 0.001, 0.001, 0.000]. The incidence of intraoperative body temperature lower than 36 ℃ in the control group was higher than that in the experimental group(47.6% vs.21.4%, χ2=6.372, P=0.012). The incidence of postoperative shivering in the experimental group was lower than that in the control group(21.4% vs.59.5%, χ2=12.649, P<0.001). There was no significant difference between the two groups in postoperative incision infection rate, average length of stay and postoperative inflammatory infection indicators(all P>0.05). Conclusions:For elderly patients undergoing posterior spinal surgery, the in-house made heat preservation socks have favorable effects on body temperature maintenance and help reduce the occurrence of hypothermia and postoperative shivering.