THE COMPUTERIZED GAIT ANALYSIS SYSTEM AND THREE DIMENSIONAL ANALYSIS OF FOOT-GROUND REACTION FORCES DURING LEVEL WALKING

A S9-2 computerized gait analysis system developed by us is reported. The advantages of the system are: synchronous measurement of the forces, angles and time parameters; high efficiency, accuracy and good repeatability; low cost and easy to operate. A three dimensional analysis of the foot-ground reaction forces of 41 normal subjects during level walking was carried out by the S9-2 system and a series of normal values of parameters and characteristic curves were obtained. The mechanism of formation of the parameters and curves and the sex influence were investigated and discussed. In old subject, before the development of "cautious gait", most values of the parameters did not differ significantly from those of the young subjects, except that the centre of gravity of the body crossing the hip earlier with a slight decrease in the medio-lateral balance capacity.     

Comparison of DNA adducts and sister chromatid exchange in lung cancer cases and controls

In a molecular epidemiological study of lung cancer cases (n = 81) and noncancer controls (n = 67), polycyclic aromatic hydrocarbon (PAH)-DNA adducts were evaluated in peripheral blood leukocytes from all subjects and in a smaller number of lung tissue specimens collected prior to or at surgery. Sister chromatid exchanges (SCE) in lymphocytes were also studied in a subset of cases and controls. Questionnaire, medical record, or tumor registry data provided a family history of cancer, as well as information on cigarette smoking, dietary and occupational exposure to PAHs, and other factors related to SCEs. In both cases and controls PAH-DNA adducts in leukocytes measured by an enzyme-linked immunosorbent assay were not significantly related to age, sex, ethnicity, amount of cigarette smoking, passive smoking, dietary charcoal, or caffeine consumption. Nor did family history of cancer or histological type of cancer significantly affect adduct levels. However, when subjects were stratified by smoking status (current, former, and nonsmoker), lung cancer cases who were current smokers had significantly higher levels of covalent adducts than current smoker controls. A seasonal variation was observed in PAH-DNA binding, with a peak in adduct levels during July-October. This peak corresponds to that seen in a prior study of aryl hydrocarbon hydroxylase inducibility by other investigators. The finding of significant levels of PAH-DNA adducts in former smokers and non-smokers supports an earlier observation that this marker is not smoking specific but reflects a pervasive and variable "background" exposure to PAH. These results are consistent with a genetically determined enhancement of PAH-DNA adduct formation in leukocytes of lung cancer cases which is evident in current smokers. The results in lung tissue are limited by the small number of samples. Adduct levels were not significantly increased in lung tissue of smokers compared with nonsmokers. An inverse linear correlation was seen between adduct values in lung tissue and age of the donors. SCEs were significantly related to pack years of smoking. However, there was no difference in the frequency of SCE between cases and controls; nor were SCE and DNA adducts significantly correlated in this small sample.     

Proanthocyanidin: a natural crosslinking reagent for stabilizing collagen matrices

While attempting to find a suitable crosslinking reagent for biopolymers, a naturally occurring proanthocyanidin (PA) obtained from grape seeds was selected to fix biological tissues. The cytotoxicity and crosslinking rate, reflected by the in vitro and in vivo degradation of fixed matrices has been studied. The shrinkage temperature of the fixed bovine pericardium increased from 66 to 86 degrees C. A cytotoxicity assay using fibroblast cultures revealed that PA is approximately 120 times less toxic than glutaraldehyde (GA), a currently used tissue stabilizer. In vitro degradation studies showed that fixed tissue was resistant to digestion by bacterial collagenase. Crosslinks between PA and tissues can be stabilized by decreasing the dielectric constant of the solution during storage. After subcutaneous implantation for periods ranging between 3 and 6 weeks, we found no apparent degradation of the GA- or PA-fixed tissues, whereas fresh tissue controls rapidly disintegrated. Beyond 6 weeks PA crosslinks began to degrade. More fibroblasts migrated and proliferated inside the PA-fixed implants compared with GA counterparts. Tissues crosslinked with PA manifested an enhanced collagen expression and deposition and did not calcify after implantation. GA, on the other hand, even after thorough rinsing continued to be cytotoxic, inhibited collagen synthesis and encouraged dystrophic calcification. Collagen matrices crosslinked with PA are expected to be of value in the design of matrices that will encourage cell ingrowth and proliferation, which are temporary in nature, and that are intended to regenerate or replace missing tissues, which can delay the biogradation of collagen. As such they should be of significant value in the emerging field of tissue engineering.     

Novel mutations in type 2 Gaucher disease in Chinese and their functional characterization by heterologous expression

We investigated 10 unrelated Chinese patients with type 2 Gaucher disease and performed ex vivo expression for the novel mutations to characterize their functional defects. These patients were diagnosed by enzymatic assays and clinicopathologic features over the past five years in a national centre in China. Genomic DNA was sequenced by a two-stage PCR approach for mutations in the functional GBA gene. Novel mutations were expressed with baculovirus-transfected Sf21 cells. Six novel mutations were found (in traditional nomenclature): P122L, Y363C, N382K, L383R, L385P, and M416V. Review of reported mutations indicated clustering of type 2 mutations in three regions of the GBA gene. Expression of novel mutations revealed that the enzyme defect could arise from one of two mechanisms: loss of catalytic activity (Y363C and M416V) or enzyme instability (P122L and N382K).     

儿童智商与父母智商的相关性

目的：通过对儿童智商（IQ）与父母亲IQ和IQ分项相关研究，探讨儿童IQ和父母亲IQ的深层关系。方法：在合肥市某中学、小学和幼儿园，分别按年龄和性别分层，随机抽取4-14岁健康儿童206名及其父母作为研究对象，应用韦氏智力量表（成人和儿童）测定儿童和其父母的IQ，填写自编的影响儿童智力发育因素调查问卷。最后在考虑儿童的年龄、性别、克托莱指数（Quetelet index）和是否独生子女等可能混杂因素下将儿童的总IQ、语言IQ和操作IQ与其父母的总IQ、语言IQ、操作IQ和IQ分项进行多元逐步回归分析。结果：按F〉2．0标准，儿童总IQ与父母亲总IQ成正相关（偏相关系数分别为0．50和0．22）；儿童语言IQ与母亲算术、母亲知识、父亲算术、父亲拼物成正相关（偏相关系数0.23-0．37）；儿童操作IQ和母亲积木图案、母亲拼物和父亲拼物成正相关（偏相关系数0．31-0．50）。结论：父母亲的总IQ和父母IQ分项中的算术、拼物、积木图案和知识等对儿童总IQ、语言IQ和操作IQ影响最大。     

Molecular epidemiologic studies of polycyclic aromatic hydrocarbon-DNA adducts and breast cancer

We review our studies on the role of polycyclic aromatic hydrocarbon (PAH)-DNA adducts in breast cancer. Additionally we report on analyses of the reliability of the scoring procedures used with immunohistochemical assay for PAH-DNA adducts and of potential bias arising from the use of benign breast disease (BBD) controls. We conducted a case-control study utilizing two control groups: BBD controls who donated tissue and blood samples, and healthy controls who donated blood samples. In comparisons of tumor tissue from cases and benign tissue from BBD controls, increasing adduct levels were significantly associated with case-control status [odds ratio (OR) = 2.40, 95% confidence interval (CI) 1.18-4.92], whereas in comparisons of nontumor tissue from cases and benign tissue from BBD controls the association was nonsignificant (OR = 1.97, 95% CI 0.94-4.17). We also show among cases, but not among BBD controls, that the GSTM1 null genotype is associated with increased adduct levels in breast tissue. Our reliability study found the scoring procedures used with the immunohistochemical assay to have high reliability, 0.93 in nontumor, 0.82 in tumor, and 0.74 in benign tissues. However, we found that the technician significantly contributed to the total variability of a series of data. Finally, we did not find a consistent bias to the null associated with the use of BBD controls; however, BBD controls may overestimate the prevalence of family history of breast cancer compared to that of healthy controls (18% vs.14%). We hypothesize that the higher prevalence results from a referral bias and discuss how this may influence our results.     

Klinefelter综合征患者和双亲对诱变剂敏感性研究

为了解诱变剂对Ｋｌｉｎｅｆｅｌｔｅｒ综合征发生的影响，对Ｋｌｉｎｅｆｅｌｔｅｒ综合征患者，患者双亲及对照进行丝裂霉素Ｃ，乙醛或乙醇诱导非二倍体，染色体结构畸变及微核观察，发现丝裂霉素Ｃ诱导的患者当色体结构畸变和微核均显著多于对照和双亲，乙醛和乙醇能诱导非二倍体和微核增加，但患者和双亲增加的程度极显著高于对照，提示Ｋｌｉｎｅｆｅｌｔｅｒ综合征患者对于丝裂霉素Ｃ，乙醛和乙醇诱导染色体畸变更敏感。双亲对     

Responses of reticulospinal neurons in the lateral reticular nucleus area of the rat to cutaneous noxious and non-noxious stimulation

Response properties of reticulospinal neurons in the lateral reticular nucleus (LRN) area to natural cutaneous stimulation were investigated systematically in 45 urethane-anesthetized rats by using extracellular recording techniques. A total of 64 neurons were tested with peripheral stimuli, of which 19 were responsive only to noxious stimuli; 7 responsive to both noxious and non-noxious stimuli; 4 responsive only to non-noxious stimuli; and 34 not responsive to any cutaneous stimuli. Both the noxious and non-noxious receptive fields were large and bilateral. Among the neurons responding to noxious stimuli, the majority (72%) was excited. This study provides evidence that some reticulospinal neurons in the rat LRN area are involved in the mechanisms of nociception.