Faculty Bibliography

OBJECTIVE:To probe into changes of cerebral vascular hemodynamics indexes (CVHI) from normal population to different clinical stage before and after occurring of stroke. METHODS:Participants were selected from 25,355 stroke cohort study population aged 35 years and over in Northeast of China and 55 acute stroke patients were selected from Fuzhou PLA General Hospital. CVHI indexes were checked during baseline investigation or within one week after acute stroke. Participant enlisted in the study were divided into following 5 groups, normal population, high risk population, individuals before stroke, acute stroke patients and convalescence stroke patients. Characteristics of CVHI indexes in different population were analyzed and compared. RESULTS:V(min) of cerebral vascular in previous defined 5 group participants were 11.39 +/- 3.27, 9.66 +/- 3.18, 6.71 +/- 3.30, 4.13 +/- 1.27, 6.78 +/- 3.09, respectively. V(mean) and V(max) were with the same decreasing trends as V(min). However, RV in 5 group participants were 62.35 +/- 21.11, 82.32 +/- 31.16, 122.72 +/- 52.73, 137.46 +/- 49.56 and 115.89 +/- 55.51, respectively. Zcv, WV, DR and CP were also with the same increasing trends as RV. Abnormal rate of CVHI score (< 75 points) from normal population to convalescence stroke patients were 13.3%, 34.7%, 74.1%, 100% and 66.7%, respectively. CONCLUSION/CONCLUSIONS:From normal population to clinical stage of stroke, cerebral vascular velocity showed decreasing trends while other indexes, such as RV, Zcv, WV, DR and CP were increasing.

OBJECTIVE:To estimate relative risk (RR) of cerebral vascular hemodynamics indexes (CVHI) accumulative score as well as some other risk factors of stroke. METHODS:A cohort study was carried out in 25 355 participants aged 35 and over in Northeast of China from 1994 to 2001. In the baseline survey, exposure rates of hypertension, diabetes, family history of stroke and hypertension, etc. were collected and CVHI was examined. CVHI accumulative score was synthesized according to contribution of single index. During the 7-year following up, 228 stroke cases were identified and stroke coming on was defined as the endpoint of observation. Uni-variable and multiple variables analysis were carried out for estimating RR of CVHI and other risk factors of stroke. RESULTS:Uni-variables analysis indicated that RR (95% confidence interval, CI) of Hypertension, heart diseases, diabetes, family history of hypertension and stroke, overweight or obesity, alcohol intake, cigarette smoking and CVHI < 75 scores were 3.23 (2.48 - 4.20), 2.53 (1.92 - 3.33), 2.38 (1.55 - 3.64), 1.32 (1.02 - 1.72), 1.82 (1.37 - 2.41), 1.62 (1.25 - 2.11), 1.48 (1.07 - 2.04), 1.76 (1.34 - 2.31) and 7.30 (5.43 - 9.80) respectively. Cox regression analysis showed that CVHI below 75 points, family history of stroke, cigarette smoking, heart disease, hypertension, age and sex were the factors being selected in equation. There was a significant dosage response between the decrease of CVHI score and the increase of stroke risk. RR of stroke reached 12.55 when CVHI below 75 points and history of hypertension appeared in the same individuals. CONCLUSION/CONCLUSIONS:Abnormality of CVHI score seemed to be the most important and independent factor among stroke risk factors. Decrease of CVHI score might serve as a marker of high risk and play important role in stroke, especially coexistence with hypertension.

OBJECTIVE:To study the reference range of cerebrovascular hemodynamics indexes (CVHI) in a sampling population. METHODS:Fourteen thousand, four hundred and eighty participants without history of stroke or exposure to risk factors were screened from 26 cities in Northeast China, North China, East China, Northwest China, South China, and Southwest China in the prospective study on stroke intervention. CVHI were checked and 95% confidence intervals were calculated using normal distribution methods, which were grouped by age, sex, area, and check positions. RESULTS:Characteristics of CVHI 95% confidence intervals showed that low limit of carotid blood velocity as V(max), V(min), V(mean) decreased, but upper limit of cerebral RV, Zcv, WV, DR and CP increased with the increase of age. However, Q(mean) and DP did not show significant trends of age difference. Low limit of Q(mean), V(max) and upper limit of RV, DR, CP and DP in males were higher than that in females while upper limit of WV and Zcv in females were higher than that in males. Left carotid low limit of Q(mean), V(mean), V(max), V(min), and upper limit of WV, Zcv and CP were higher than that of the right but upper limit of RV, DR and DP were lower than that of the right. There were no obvious differences between areas. CONCLUSION/CONCLUSIONS:Obvious differences of CVHI 95% confidence intervals ranges were found between age groups, sex, and checking positions, respectively, suggesting that the reference ranges of CVHI to be estimated by every subgroup.

OBJECTIVE:To evaluate efficacy and optimal cut-off-point through cerebral vascular hemodynamic indexes (CVHI) examination to predict stroke. METHODS:A number of 20,333 people at 35 years old and over were checked by CVHI and accumulative score was calculated according to the value of detected indexes. Risk factors of stroke were investigated simultaneously. One hundred and sixty-eight patients with stroke occurred during 4-year following up. Typical syndromes and signs stroke were used as golden standard to evaluate screening efficacy of CVHI. RESULTS:Score of optimal cut-off-point of cerebral vascular hemodynamic indexes was under 75 in ROC curve analyses. Sensitivity, specificity, accuracy, positive and negative predictive values, positive and negative likelihood ratios as well as Youden's index for predicting stroke within 4 years after examination were found to be 87.50%, 67.70%, 67.86%, 2.21%, 99.85%, 2.71, 0.18 and 0.55 respectively. Sensitivity and positive predict values for predicting cerebral vascular thrombosis were superior to predicting cerebral hemorrhage. Positive predicting value in risk exposure population was higher than that of overall population. Coefficiency of variation of cerebral vascular hemodynamic examination was 4.03%. The agreement rate of examination between two physicians was 97.62% and Kappa value was 0.94. CONCLUSION/CONCLUSIONS:The score of optimal cut-off-point of cerebral vascular hemodynamic indexes examination was 75. Both Efficacy and reliability for predicting stroke seemed to be good, especially for predicting cerebral vascular thrombosis.

The pathogenicity of Borrelia burgdorferi sensu stricto clinical isolates representing 2 distinct ribosomal DNA spacer restriction fragment-length polymorphism genotypes (RSTs) was assessed in a murine model of Lyme disease. B. burgdorferi was recovered from 71.5% and 26.6% of specimens from mice infected with RST1 and RST3 isolates, respectively (P<.0001). The average ankle diameter and histologic scores for carditis and arthritis were significantly higher after 2 weeks of infection among mice infected with RST1 isolates than among those infected with RST3 isolates (P<.001). These clinical manifestations were associated with larger numbers of spirochetes in target tissues but not with the serum sensitivity of the individual isolates. Thus, the development and severity of disease in genetically identical susceptible hosts is determined mainly by the pathogenic properties of the infecting B. burgdorferi isolate. The RST1 genotype is genetically homogeneous and thus may represent a recently evolved clonal lineage that is highly pathogenic in humans and animals.

Variability of disease manifestations has been noted in patients with Lyme disease. A contributing factor to this variation may be the number of spirochetes present in infected patients. We evaluated clinical and laboratory findings for patients with erythema migrans with regard to the number of Borrelia burgdorferi organisms detected by quantitative PCR (qPCR) in 2-mm skin biopsy specimens. B. burgdorferi was detected in 80% (40 of 50) of the specimens tested; the mean number of spirochetes in these specimens ranged over 3 orders of magnitude (10 to 11,000 spirochetes per 2-mm biopsy specimen). Larger numbers of spirochetes were significantly associated with a shorter duration of the erythema migrans skin lesion (P = 0.020), smaller skin lesions (P = 0.020), and infection with a specific genotype of B. burgdorferi (P = 0.008) but not with the number or severity of symptoms. Skin culture positivity was significantly associated with skin lesions containing larger numbers of spirochetes (P = 0.019).

Direct detection of Borrelia burgdorferi sensu lato, the etiologic agent of Lyme borreliosis, is the most reliable laboratory diagnostic tool. Several methods have been developed for direct detection of B. burgdorferi in infected vectors, host tissues, and clinical specimens from patients with Lyme borreliosis. These include microscope-based assays, antigen detection assays, in vitro cultivation, and nucleic acid-based detection of B. burgdorferi. The sensitivity and specificity of these methods depend on various factors and are also variable among laboratories. To date, only in vitro cultivation of B. burgdorferi has been widely accepted to confirm clinical diagnosis of Lyme borreliosis. Nevertheless, various polymerase chain reaction-based molecular assays have shown increasing significance in the laboratory diagnosis of Lyme borreliosis because of their high sensitivity, specificity, and capability for quantification and typing of spirochetes in clinical specimens. In this review, the currently available methods for direct detection of B. burgdorferi in clinical samples and quantitative analysis of spirochete load in different biological sources are discussed.