Faculty Bibliography

Human granulocytic anaplasmosis (HGA) is a potentially fatal tick-borne infection caused by Anaplasma phagocytophilum. Treatment options are limited for this entity, with doxycycline being the drug of choice. Certain fluoroquinolones such as levofloxacin are active against A. phagocytophilum in vitro. We report a hospitalized patient with HGA who improved coincident with a 13-day course of levofloxacin therapy, but clinically and microbiologically relapsed 15 days after completion of treatment. Relapse of infection after levofloxacin therapy was reproduced in a severe combined immune-deficient (SCID) mouse infection model. Quinolone therapy should not be considered curative of HGA

A large amount of knowledge has been acquired since the original descriptions of Lyme borreliosis (LB) and of its causative agent, Borrelia burgdorferi sensu stricto. The complexity of the organism and the variations in the clinical manifestations of LB caused by the different B. burgdorferi sensu lato species were not then anticipated. Considerable improvement has been achieved in detection of B. burgdorferi sensu lato by culture, particularly of blood specimens during early stages of disease. Culturing plasma and increasing the volume of material cultured have accomplished this. Further improvements might be obtained if molecular methods are used for detection of growth in culture and if culture methods are automated. Unfortunately, culture is insensitive in extracutaneous manifestations of LB. PCR and culture have high sensitivity on skin samples of patients with EM whose diagnosis is based mostly on clinical recognition of the lesion. PCR on material obtained from extracutaneous sites is in general of low sensitivity, with the exception of synovial fluid. PCR on synovial fluid has shown a sensitivity of up to >90% (when using four different primer sets) in patients with untreated or partially treated Lyme arthritis, making it a helpful confirmatory test in these patients. Currently, the best use of PCR is for confirmation of the clinical diagnosis of suspected Lyme arthritis in patients who are IgG immunoblot positive. PCR should not be used as the sole laboratory modality to support a clinical diagnosis of extracutaneous LB. PCR positivity in seronegative patients suspected of having late manifestations of LB most likely represents a false-positive result. Because of difficulties in direct methods of detection, laboratory tests currently in use are mainly those detecting antibodies to B. burgdorferi sensu lato. Tests used to detect antibodies to B. burgdorferi sensu lato have evolved from the initial formats as more knowledge on the immunodominant antigens has been collected. The recommendation for two-tier testing was an attempt to standardize testing and improve specificity in the United States. First-tier assays using whole-cell sonicates of B. burgdorferi sensu lato need to be standardized in terms of antigen composition and detection threshold of specific immunoglobulin classes. The search for improved serologic tests has stimulated the development of recombinant protein antigens and the synthesis of specific peptides from immunodominant antigens. The use of these materials alone or in combination as the source of antigen in a single-tier immunoassay may someday replace the currently recommended two-tier testing strategy. Evaluation of these assays is currently being done, and there is evidence that certain of these antigens may be broadly cross-reactive with the B. burgdorferi sensu lato species causing LB in Europe

OBJECTIVE:To evaluate the effectiveness of stroke prevention among high risk population, using Nao'an Capsules. METHODS:Participants were selected from 696,558 residents in Nanhui, using county of Shanghai city. Individuals aged 35 years old and over with at least one risk factor exposure to stroke, received cerebral vascular hemodynamic examination. 18,271 cases meeting the criteria of cerebral vascular hemodynamic indexes accumulative score below 70 points were defined as individuals with high-risk and targets to receive intervention. According to the willingness of the participants, 10,313 cases received Nao'an Capsules for intensive intervention based on general intervention measures compared to 7958 cases only receiving general intervention. After the implementation of intervention, incidence and mortality rates of stroke and the effectiveness of three-year intervention were studied. RESULTS:Incidence of stroke in Nao'an Capsules group was significantly lower than that of the general intervention (P < 0.01) with 53.8% in males and 58.4% in females. The relative risk (RR) in two gender groups were 0.46 (0.33 - 0.64) and 0.39 (0.30 - 0.50) respectively. Multiple logistic regression analysis indicated that the history of hypertension, accumulative score of cerebral vascular hemodynamic indexes, age, gender and Nao'an Capsules intervention were the variables selected into the equation and significantly related to stroke. Among the variables, Nao'an Capsule was the strongest factor with a RR of 0.41. CONCLUSION/CONCLUSIONS:Incidence of stroke in Nao'an Capsule intervention group was significantly lower than that in the general intervention group after 3 years of intervention, suggesting that Nao'an Capsule intervention was the strongest factor affecting stroke occurrence in individuals at high-risk.

BACKGROUND:Borrelia lonestari infects Amblyomma americanum, the tick species that is the most common cause of tick bites in southeast and south-central United States, and this spirochete has been detected in an erythema migrans (EM)-like skin rash in 1 patient. Therefore, B. lonestari is considered to be a leading candidate for the etiologic agent of EM in this region. METHODS:Skin biopsy specimens obtained from patients from the Cape Girardeau area of Missouri who had EM-like lesions were cultured in Barbour-Stoenner-Kelly medium and evaluated by polymerase chain reaction (PCR) targeting multiple genes. Serum specimens were tested by enzyme-linked immunosorbent assay for antibodies against sonicated whole-cell Borrelia burgdorferi. Results were compared with those obtained over the same period for patients from New York State who had EM. RESULTS:B. lonestari was not detected by PCR in any of 31 skin biopsy specimens collected from 30 Missouri patients. None of 19 cultures of Missouri skin samples that were suitable for evaluation were positive for B. burgdorferi, compared with 89 (63%) of 142 cultures of samples collected from New York State patients (P<.001). None of the 25 evaluable Missouri patients were seropositive for antibodies against B. burgdorferi, compared with 107 (75%) of 143 New York State patients (P<.001). CONCLUSIONS:Neither B. lonestari nor B. burgdorferi is likely to be the cause of EM-like skin lesions in patients from the Cape Girardeau area of Missouri. The etiology of this condition remains unknown.

OBJECTIVE:To probe into the relationship between hypertension and hemodynamic score of cerebral vascular accumulative function by though studying the history of hypertension and level of blood pressure. METHODS:The database of blood pressure and cerebral vascular hemodynamic indexes (CVHI) were from baseline data and measurement in a cohort. 18,512 participants who met the included criteria were enlisted in the study. The function scores were estimated using uniform methods according to CVHI. Participants were grouped by age, years of having hypertension and level of blood pressure. Differences of the function score between different groups were compared. RESULTS:The function score in hypertension group was significantly lower than that of normal tension group, which decreased by 13.3 points. Within 5 years of hypertension history, the function score decreased as course of hypertension prolonged. The same trend was found between the score and level of both systolic and diastolic blood pressure. When systolic blood pressure elevated to 140 mmHg or diastolic blood pressure elevated to 95 mmHg, the function score was below 75 points. CONCLUSION/CONCLUSIONS:There were significant relationship between decrease of the function scores and medical history, course of hypertension as well as level of blood pressure.

The effects of variations in Barbour-Stoenner-Kelly (BSK) medium on the infectivity and pathogenicity of Borrelia burgdorferi clinical isolates were assessed by retrospective and prospective studies using a murine model of Lyme borreliosis. Thirty of 35 (86%) mice infected with any of six virulent B. burgdorferi clinical isolates grown in a BSK-H medium developed clinically apparent arthritis. By contrast, arthritis was observed in only 25 of 60 (42%) mice inoculated with two of these B. burgdorferi strains grown in a different lot of BSK-H medium (P < 0.001). In a prospective study, mice inoculated with a B. burgdorferi clinical isolate grown in a BSK medium prepared in-house produced significantly greater disease than those injected with the same isolate cultured in BSK-H medium (P < 0.05). The attenuated pathogenicity is not due to the loss of plasmids during in vitro cultivation. The data suggest that variations in BSK medium have a significant impact on the infectivity and pathogenicity of B. burgdorferi clinical isolates.

To investigate the role of Toll-like receptor 2 (TLR2)-mediated signaling in host innate defense and development of Lyme disease, the pathogenicity of Borrelia burgdorferi sensu stricto clinical isolates representing two distinct genotypes (RST1 and RST3A) was assessed in TLR2(-/-) C3H/HeJ mice. All TLR2(-/-) mice infected with a B. burgdorferi RST1 isolate developed severe arthritis. The numbers of spirochetes in heart, joint and ear biopsy specimens were significantly higher in TLR2(-/-) mice than in wild-type mice similarly infected as determined by real-time quantitative polymerase chain reaction. Interestingly, despite the higher spirochete levels in heart tissues, milder carditis was observed in TLR2(-/-) than in wild-type mice infected with this RST1 isolate (P=0.02). By contrast, no positive cultures were obtained from any of the blood and tissue specimens from TLR2(-/-) mice inoculated with two RST3A clinical isolates. The data suggest that there is impaired host innate defense against infection and TLR2-independent killing of B. burgdorferi clinical isolates in TLR2-deficient C3H/HeJ mice.

OBJECTIVE:To describe the distribution of cerebral vascular hemodynamic indexes (CVHI). METHODS:A number of 25,355 age 35 and over were selected in the Northeast China by cluster sampling. CVHI were checked during baseline survey and were followed to see the occurrence of stroke. Distribution of CVHI among non-stroke population, individuals prior to the onset of stroke and patients with stroke were described. RESULTS:The CVHI accumulative score, V(mean), V(max) and V(min) were dramatically decreasing, but RV, Zcv, WV and DR were significantly increasing as age increased. V(max), RV and CP were significantly higher in males but WV was lower than that of females. The CVHI accumulative score, V(min) and RV were 95.0, 10.23 and 75.8 in non-stroke population, 51.25, 6.71 and 122.72 pre stroke group, and 55.0, 6.78 and 115.89 in patients with stroke respectively. There were significant differences among three groups after controlling of age and sex (P < 0.01). CONCLUSION/CONCLUSIONS:Variance of CVHI was closely related to age, and there appeared a significant abnormal of CVHI before and after stroke.

OBJECTIVE:To establish a predicting model for stroke according to cerebral vascular hemodynamic indexes and major risk factors of stroke. METHODS:Participants selected from a stroke cohort with 25,355 population in China. The first step was to carry out principal component analysis using CVHI. Logistic regression with principal component and main risk factors of stroke were then served as independent variables and stroke come on as dependent variables. The predictive model was established according to coefficient of regression and probability of each participant was also estimated. Finally, ROC curve was protracted and predictive efficacy was measured. RESULTS:The accumulative contribution rates of four principal components were 58.1%, 79.4%, 88.4% and 94.6% respectively. Seven variables were being selected into the equation with the first to fourth principal component as history of hypertension, age and sex. Area under ROC curve was 0.855 and optimal cut-off point was probability over 0.05. Sensitivity, specificity and accuracy of stroke prediction were 80.7%, 78.5% and 78.5% respectively. CONCLUSION/CONCLUSIONS:The model established by principal component and regression could effectively predict the incidence of stroke coming on.

The density of spirochetes in field-collected or experimentally infected ticks is estimated mainly by assays based on microscopy. In this study, a real-time quantitative PCR (qPCR) protocol targeting the Borrelia burgdorferi-specific recA gene was adapted for use with a Lightcycler for rapid detection and quantification of the Lyme disease spirochete, B. burgdorferi, in field-collected Ixodes scapularis ticks. The sensitivity of qPCR for detection of B. burgdorferi DNA in infected ticks was comparable to that of a well-established nested PCR targeting the 16S-23S rRNA spacer. Of the 498 I. scapularis ticks collected from four northeastern states (Rhode Island, Connecticut, New York, and New Jersey), 91 of 438 (20.7%) nymphal ticks and 15 of 60 (25.0%) adult ticks were positive by qPCR assay. The number of spirochetes in individual ticks varied from 25 to 197,200 with a mean of 1,964 spirochetes per nymphal tick and a mean of 5,351 spirochetes per adult tick. No significant differences were found in the mean numbers of spirochetes counted either in nymphal ticks collected at different locations in these four states (P = 0.23 by one-way analysis of variance test) or in ticks infected with the three distinct ribosomal spacer restriction fragment length polymorphism types of B. burgdorferi (P = 0.39). A high degree of spirochete aggregation among infected ticks (variance-to-mean ratio of 24,877; moment estimate of k = 0.279) was observed. From the frequency distribution data and previously published transmission studies, we estimated that a minimum of 300 organisms may be required in a host-seeking nymphal tick to be able to transmit infection to mice while feeding on mice. These data indicate that real-time qPCR is a reliable approach for simultaneous detection and quantification of B. burgdorferi infection in field-collected ticks and can be used for ecological and epidemiological surveillance of Lyme disease spirochetes.