[The association between serum total homocysteine and subacute combined degeneration of spinal cord].

Objective: The research was aimed to investigate the association between serum total homocysteine (tHcy) and subacute combined degeneration of the spinal cord (SCD). Methods: A retrospective survey of 106 newly diagnosed patients with SCD were enrolled in this research who were treated in the department of neurology of Xijing Hospital from January 2008 to February 2019, meanwhile, 121 patients with spinal cord lesion (not SCD) and 104 neurology mild outpatients were selected as controls. Serum tHcy level was determined by using the chemiluminescent immunoassay assay. A multivariate logistic regression model was used to analyze the risk factors for SCD. The area under the curve (AUC) of the receiver operating characteristic (ROC) curve, sensitivity, specificity and Youden index were used to evaluate the diagnostic efficacy of tHcy. Spearman correlation analysis was used to observe the correlation between tHcy and SCD severity. The SCD patients were categorized into normal or mild tHcy group, moderate tHcy group, and severe tHcy group based on tHcy levels. Clinical symptoms, nerve conduction velocity, magnetic resonance imaging (MRI) findings from the patients were studied. Results: The serum tHcy levels in SCD patients were 64.3(26.5, 98.8) µmol/L, while in patients with spinal cord lesion (not SCD) group were 13.7(10.8, 19.2) µmol/L, neurology mild outpatients were 10.6(8.2, 13.0) µmol/L, which was higher in SCD group (H=112.020,P<0.001), (H=165.525,P<0.001).The multivariate logistic regression model showed tHcy is the impact factor of SCD (OR=1.107, 95%CI:1.077-1.139, P<0.001). At ROC analysis, tHcy showed diagnostic value with an optimal cut-off value of 24.9 µmol/L (AUC 0.913, 95%CI: 0.875-0.951, sensitivity 79.2%, specificity 91.6%). Spearman correlation analysis showed that tHcy was positively correlated with functional disability rating scale (r=0.254, P=0.009). Conclusions: Serum tHcy is the risk factor for SCD and related to its disability. Focus on the increased level of tHcy plays a positive role in the diagnosis of SCD.

[The association between single nucleotide polymorphism of interleukin-1ß gene rs1143627 site and susceptibility to active tuberculosis].

Objective: To investigate the relationship between single nucleotide polymorphism (SNP) of IL-1ß gene and susceptibility to tuberculosis. Methods: A case-control study was conducted in Shenzhen Third People's Hospital from January 2012 to December 2014. A total of 1 533 patients with active tuberculosis were enrolled, including 1 432 cases of pulmonary tuberculosis[920 males and 512 females, mean age (37±14) years] and 101 cases of extrapulmonary tuberculosis [60 males and 41 females, mean age (35±13) years]. At the same time, 1 445 healthy controls (882 males and 563 females, mean age (37±20) years) were selected. The genotypes of rs1143627, rs1143623, rs16944 and rs2853550 of IL-1ß gene were detected by time-of-flight mass spectrometry. The allele frequencies of rs1143627 T>C (-31) were compared between patients with pulmonary tuberculosis and those with extrapulmonary tuberculosis. Fifty-three patients with active tuberculosis [male 32, female 21, mean age (37±15) years] were randomly selected, and the correlation between SNP alleles and tuberculosis severity was analyzed before and after treatment. Results: Time-of-flight mass spectrometry effectively detected the genotypes of 4 SNP loci. Among the 4 SNP loci, only the allele frequency of -31 locus was significantly different between the active tuberculosis group and the control group. The allele frequency of rs1143627 T locus in active tuberculosis group was 53.3%(1 634/3 066), which was significantly higher than that in the healthy control group 48.7%(1 407/2 890; OR=1.20, 95%CI=1.09-1.33, P=0.001 6) .The frequencies of the other 3 SNP alleles were not significantly different between the active tuberculosis group and the control group. The frequencies of the other 3 SNP alleles were 59% (1 821/3 066) and 60% (1 732/2 890) for rs1143623 G allele, 51% (1 574/3 066) and 52% (1 499/2 890) for rs16944 G allele, and 64% (1 964/3 066) and 65% (1 875/2 890) for rs2853550 T allele respectively. Stratified analysis showed that the frequency of the -31 T allele in patients with extrapulmonary tuberculosis (62.9%, 127/202) was significantly higher than that in patients with pulmonary tuberculosis (52.6%,1 507/2 864) (OR=1.53; 95% CI=1.13-2.05; P=0.005).The HRCT scores of patients with rs1143627 TT, TC and CC genotypes were 26.6, 13.9 and 13.3 respectively before anti-tuberculosis treatment, and after 2 years of anti-tuberculosis treatment, the HRCT scores of patients with rs1143627 TT, TC and CC genotypes were 14.7, 6.6 and 5.4 respectively, which indicated that TB patients with rs1143627T allele were associated with more severe pulmonary disease. Conclusion: The SNP of IL-1ß-31T>C was associated with susceptibility to active tuberculosis, and T allele was the susceptible gene and individuals carrying T allele were more likely to develop extrapulmonary tuberculosis.

Aspergillus fumigatus diffusates suppress polymorphonuclear neutrophil phagocytic functions and respiratory burst levels in hematopoietic stem cell transplantation patients.

Invasive aspergillosis (IA) is a severe infection that commonly occurs in immunocompromised patients after hematopoietic stem cell transplantation (HSCT). The present study explores the effect of Aspergillus fumigatus diffusates (AfDs) on phagocytic function and superoxide anion (O2(-)) burst levels in polymorphonuclear neutrophils (PMNs) from post-HSCT patients. A. fumigatus conidia with or without AfD were used to stimulate the PMN from healthy donor or HSCT patient for two hours. PMN morphology was visualized by scanning electron microscopy. The levels of respiratory burst O2(-) produced by the PMNs were determined by flow cytometry. PMN phagocytic rates and phagocytic indexes were observed and calculated using periodic acid-Schiff (PAS) staining under a light-field microscope. No difference was found between the PMN phagocytic rates, phagocytic indexes, or O2(-) respiratory burst levels in health donor PMNs following treatments of A. fumigatus conidia with or without AfD. However, significant inhibition of these indices was seen in the PMNs from HSCT patients following treatment of A. fumigatus conidia plus AfD, compared to that with conidium treatment alone (P < 0.05). Therefore, AfD significantly inhibited the phagocytic function of PMNs from HSCT patients, potentially through inhibition of intracellular respiratory burst levels during phagocytosis. This suggests that the reason underlying the greater susceptibility of HSCT patients to aspergillosis might be the existence of AfD in vivo during infection. Further research on the mechanisms by which AfD affects the phagocytic function of PMNs from HSCT patients is therefore of great significance for the prevention of IA.

Recurrence of peptic ulcer in uraemic and non-uraemic patients after Helicobacter pylori eradication: a 2-year study.

BACKGROUND: The role of Helicobacter pylori in the pathogenesis of peptic ulcer disease in patients with uraemia remains unclear. AIM: To evaluate the long-term effect of H. pylori eradication in these patients. METHODS: Uraemic and non-uraemic patients with peptic ulcer were enrolled in this study. Patients having history of non-steroidal anti-inflammatory drugs use or cardiovascular disease that need aspirin use were excluded. After confirmation of H. pylori infection, they received a triple therapy and were followed up for 2 years. RESULTS: Between September 1999 and December 2005, 34 patients (41%) of the end-stage renal disease [H. pylori (+) group] and 67 (84%) of the non-uraemic patients with peptic ulcer disease (PU group) received anti-H. pylori therapy. After triple therapy, 32 (94%) from the end-stage renal disease group and 64 (96%) from the peptic ulcer group obtained successful eradication. During the 2-year follow-up, three patients in the end-stage renal disease group were excluded because of the presence of cardiovascular disease and aspirin use in two cases and died of heart failure in one case; two patients in peptic ulcer group refused follow-up. Finally, 29 uraemic and 62 non-uraemic patients had achieved the follow-up. Recurrence of peptic ulcer was more in the end-stage renal disease group than in the peptic ulcer group with intention-to-treat analysis (eight of 32, 25% vs. two of 64, 3%, P = 0.001, OR: 10.0, 95% CI: 1.979-50.540) or per-protocol analysis (eight of 29, 28% vs. two of 62, 3%, P < 0.001, OR: 11.4, 95% CI: 2.245-58.168). CONCLUSIONS: Peptic ulcer recurrence after H. pylori eradication is higher in end-stage renal disease patients with peptic ulcer than in peptic ulcer patients without renal disease. Factors aside from H. pylori play an important role in peptic ulcer recurrence in end-stage renal disease patients.

[Immunocytochemical study of mononuclear cells in peripheral blood and cerebrospinal fluid of patients with Japanese B encephalitis].

Using the technique of monoclonal antibody-immunogold-silver staining (M-IGSS), the mononuclear cells in peripheral blood (PB) and cerebrospinal fluid (CSF) were screened for immunoreactivity against JBE virus antigen (JBEV-Ag), interleukin-2 receptor (Tac), class II human leucocyte antigen (HLA-DR) and interferon-r (IFN-r) in 17 ELISA diagnosed JEB patients and 17 control cases with non-inflammatory and non-immunological diseases. It was found that JBEV-Ag+ cells were present in PB (16/17) and CSF (12/17) of the JBE group, but absent in both the control group and another 5 cases with mumps virus meningitis. The percentages of Tac+, HLA-DR+ and IFN-r+ cells in JBE patients were higher than those in controls.

[Experimental studies on therapeutic effect of rat monoclonal antibody-bleomycin A6 conjugate against human colorectal cancer].

Bleomycin A6 (A6), a single component of bleomycin complex, is highly active against human colon and cecum cancer cells in vitro and xenografts in nude mice. R19, a rat monoclonal antibody against human cecum cancer Hce-8693 cells, was linked to A6. R19-A6 conjugate retained complete activity of McAb R19 and 10% activity of A6. As determined by clonogenic assay with human cecum cancer Hce-8693 cells for 1 hour exposure. The 50% inhibitory concentration (IC50) values for R19-A6, A6 and M3-A6 (conjugate of irrelevant Mc-A6) were 0.019, 1.05 and 1.00 mumol/L, respectively. The effect of the conjugate R19-A6 was 55-fold stronger than that of free A6 and 53-fold than irrelevant conjugate M3-A6. Clonogenic assay with human colon cancer HT-29 cells showed that the IC50 values were 0.078 mumol/L and 4.0 mumol/L for R19-A6 and free A6, respectively. The cytotoxicity to Hce-8693 and HT-29 cells was markedly blocked by unconjugated McAb R19 but not by irrelevant McAb MARK-3. The R19-A6 conjugate exerted 90% inhibition on the growth of cecum cancer Hce-8693 xenografts in nude mice, whereas equivalent doses of free A6, R19 plus A6 mixture and M3-A6 showed 52%, 34% and 48% inhibition, respectively. Histopathological examination showed no toxic changes in the heart, lung, liver, kidney and bone marrow in the R19-A6 conjugate treated animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Anthropomorphic dummy neck modeling and injury considerations.

This study investigates the modeling of the Hybrid III dummy head and neck system and its response under impulsive loading. Two neck models were proposed, one rigid, one flexible; both give satisfactory head kinematics upon comparing to minisled test results. The flexible neck model provides a more detailed understanding of the Hybrid III neck structure behavior. It indicates that the Hybrid III neck has a torque response similar to a human neck but has higher shear response. During flexion whiplash, the torque at the occipital condyle reverses its direction at about 25 ms after impact. Since concussion may be related to the head angular acceleration, which reaches its peak value in the first 25 ms, it might be necessary to extend the existing human torque-rotation corridor to include the neck response in this region. For flexion whiplash impact, simulation results indicated that the neck injury threshold is reached before exceeding the head injury threshold as the impact velocity is increased.

Response of a human head/neck/upper-torso replica to dynamic loading--I. Physical model.

A human head/neck/upper-torso replica was constructed and instrumented and its response to impact and dynamic loading was studied. The model consists of a water-filled cadaver skull; plastic vertebrae, sternum and ribs; silicon rubber disks and ligaments; and fabric muscles. The static behavior of the system under sagittal plane and lateral loading was adjusted so as to correspond to that of cadaver behavior under similar loading. The structure was loaded impulsively by the sudden arrest of a supporting sled running on a track and by direct head impact with a suspended steel ball. The measured response included the head acceleration, the disk pressures, the muscle strains, the intracranial pressures and the skull strains; the sled motion was also monitored. These data were recorded with a microcomputer and oscilloscopes; the overall system deformation was observed by high-speed cameras. The muscle contraction effects were determined with the aid of microcomputer-controlled devices including a vacuum system, solenoid valves and plastic syringes.

Response of a human head/neck/upper-torso replica to dynamic loading--II. Analytical/numerical model.

A three-dimensional lumped-parameter model of the human head/neck/upper-torso was developed to predict its motion for any specified initial conditions and that could also be used to compare with the results of other investigators. This model consists of ten rigid bodies representing the head, cervical vertebrae C1-C7, T1 and T2 combined with the rest of the torso. These rigid bodies were connected by intervertebral joints described by a stiffness matrix relating the force (moment) and translation (rotation). Fifteen pairs of muscles were incorporated in the model, represented by three-point linear elements with nonlinear constitutive relationships obtained from cadaver test results. The calculated response compared favorably with human volunteer data for both flexion and lateral whiplash. However, tests on an inanimate replica of a human indicated greater flexibility than predicted by the corresponding numerical model. The difference is believed to be due to insufficient mass of the muscles incorporated in the structure.

Three-dimensional response of a lumped parameter head-neck model due to impact and impulsive loading.

A numerical procedure developed previously for predicting sagittal-plane motion of the human head-neck system due to impact and impulsive loading has been extended to three dimensions. In both situations, a lumped parameter approach is employed, but the current model lumps the mechanical response of each intervertebral joint into a single force-deformation relation evaluated from mechanical properties assembled by various investigators. Computations were performed to obtain the response of the model to a two-dimensional case of flexion whiplash, to one three-dimensional case of side impact to the skull and to another involving base acceleration normal to the sagittal plane. Agreement of the kinematic variables with the results of both the previous two-dimensional analysis and experimental data from a volunteer run is satisfactory, but somewhat poorer correspondence was found for the three-dimensional predictions upon comparison with data obtained from a physical model and from a volunteer when subjected to the prescribed loading. The differences in response are attributed to higher stiffness of facet separation of the model relative both to the structure and the volunteer, to insufficient damping, as well as to substantial differences in the mechanical deformation characteristic of the components of the prototypes and the numerical model.

The measurement of audiometric zero level of air conduction.

The audiometric zero level of air conduction for 100 healthy youths was determined over a frequency range from 20 Hz to 10 KHz in 1971-1973 under the laboratory conditions. The results obtained have been further verified recently on a selected group of 12 persons. This paper also presents the transfer experiments from the original earphone TDH-39(MX-41/AR) to six other types of earphones. The deviation of our data thus obtained from the recommendation by ISO is discussed.