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Biomedical subjects

Barry P Katz

Publications and source records attributed to Barry P Katz.

At least 19 recordsLinked to original sources

Risk factors for early radiographic changes of tibiofemoral osteoarthritis.

OBJECTIVE: To evaluate the risk factors for early radiographic changes of knee osteoarthritis. METHODS SUBJECTS: (n = 114) with unilateral or bilateral grade 0-1 knee osteoarthritis underwent x ray examination of the knees (semiflexed anteroposterior view) and assessment with the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index at baseline and 30 months later. Severity of joint space narrowing (JSN) and osteophytosis were graded in randomly ordered serial radiographs by two readers, blinded to the sequence of the films, using standard pictorial atlases. RESULTS: The odds of an initial appearance of radiographic features of knee osteoarthritis at month 30 were more than threefold greater in African Americans than in whites (osteophytosis: odds ratio (OR) 3.30, 95% confidence interval (CI) 1.04 to 10.54; JSN: OR 3.49, 95% CI 1.16 to 10.68). In addition, the appearance of osteophytosis was positively related to baseline stiffness (OR 1.91/2.1 points on the 2-10 WOMAC scale, 95% CI 1.29 to 2.82). CONCLUSIONS: The distinction between incident and established, but early, radiographic knee osteoarthritis is difficult because of the limits to which all possible evidence of the disease can be ruled out in a conventional baseline knee radiograph. Nonetheless, our finding that African Americans were at greater risk of early osteophytosis and JSN than other subjects differs from the results of our previous analysis of risk factors for progressive knee osteoarthritis in the same subjects. The development of osteophytes also was associated with joint stiffness. Future investigations should focus on the systemic and local influences that these ostensible risk factors represent.

Black or African American↗

Expression of OmpP2A and OmpP2B is not required for pustule formation by Haemophilus ducreyi in human volunteers.

Haemophilus ducreyi express two porin proteins, termed OmpP2A and OmpP2B. To test whether expression of OmpP2A and OmpP2B was necessary for virulence in humans, eight volunteers were experimentally infected with the parent (35000HP) in one arm and a double OmpP2A OmpP2B mutant (35000HP::P2AB) in the other arm. The pustule formation rates were 58.3% (95% CI, 33.2-83.5%) for the parent and 41.7% (95% CI, 19.3-64.0%) for the mutant (P=0.25). Biopsy of 35000HP and 35000HP::P2AB-infected sites yielded similar amounts of bacteria in quantitative culture. These results indicate that expression of OmpP2A and OmpP2B is not necessary to initiate disease or to progress to pustule formation in humans.

Adult↗

Factors associated with time of day of sexual activity among adolescent women.

BACKGROUND: Our objective was to describe familial, intrapersonal, and partner-related factors associated with time of day of sexual activity among adolescent women. METHODS: Annual questionnaires and daily diaries were collected from 106 adolescents. Participants contributed up to 3 questionnaires and 5 12-week diary periods over 27 months. Predictor variables included type of day (weekend, school day, vacation day); partner variables (argument with partner, partner emotional support, time spent with partner); parent/family variables such as supervision, monitoring, and attitudes about adolescent sexual behavior; and mood and behavior variables such as negative mood, positive mood, and sexual interest. The outcome variable for each diary day was no coitus, coitus between noon and 6 pm, or coitus after 6 pm. RESULTS: Coitus occurred on 12.0% of the diary days. Coital events were more than twice as likely to occur after 6 pm (8.5% of days) than in the afternoon (3.5% of days). Afternoon sex was least likely to occur on school days whereas evening sex occurred most often on weekends. An argument with a partner, partner emotional support, time spent with partner, sexual interest, and coital frequency were associated with increased likelihood of afternoon sex, whereas parental supervision and negative mood were associated with decreased likelihood of afternoon sex. For school days, skipping school was associated with increased likelihood of afternoon sex. Evening/night sexual activity was not associated with any parent/family variables. CONCLUSION: Afternoon sex on school days is relatively uncommon. Direct parental supervision may decrease afternoon sexual activity but relationship and intrapersonal factors also are important factors in the timing of sexual activity on any given day.

Adolescent↗

Incidence and prevalence of herpes simplex virus infections in adolescent women.

OBJECTIVES: We conducted this study to examine the incidence, prevalence, and risk factors for herpes simplex virus (HSV) 1 and HSV 2 infection in a cohort of young women who were closely followed for acquisition of sexually transmitted infections. STUDY DESIGN: Women between the ages of 14 and 18 years had blood and genital specimens obtained quarterly to test for incident sexually transmitted infections. Subjects also had 2 12-week periods each year when they kept a detailed behavioral diary and performed weekly vaginal swabs. Serum specimens were tested for HSV 1 and HSV 2 antibody, and genital specimens were tested for HSV DNA by PCR. RESULTS: A total of 100 subjects enrolled and had at least 2 sera that could be analyzed for seroconversion. The mean age of the subjects was 15.8 years at entry. The HSV 1 and HSV 2 seroprevalence at entry was 59.6% and 13.5%, respectively. During the study, 4 subjects acquired HSV 1 antibody and 7 acquired HSV 2 antibody, but there were no cases of symptomatic HSV infection identified. The annualized incidence among susceptible individuals was 8.9% for HSV 1 and 7.4% for HSV 2. Three of the 7 HSV 2 sero-converters had HSV 2 DNA detected in vaginal swabs. Age, duration of sexual activity, and the presence of other sexually transmitted infections were predictors of HSV 2 antibody positivity. CONCLUSIONS: Acquisition of HSV 1 and HSV 2 is relatively common in adolescent women, although symptomatic infection is uncommon. HSV 2 is shed in the genital tract despite the lack of symptoms.

Adolescent↗

A DltA mutant of Haemophilus ducreyi Is partially attenuated in its ability to cause pustules in human volunteers.

Haemophilus ducreyi produces two outer membrane proteins, called DltA (H. ducreyi lectin A) and DsrA (H. ducreyi serum resistance A), that contribute to the ability of the organism to evade complement-mediated serum killing. In contrast to their isogenic parent strain, 35000HP, the DsrA mutant FX517 exhibits 0% survival in 50% normal human serum and the DltA mutant FX533 exhibits 23% survival. Compared to 35000HP, FX517 does not cause pustule formation in human volunteers. To test whether DltA was required for virulence in humans, seven volunteers were experimentally infected with 35000HP and FX533. Four subjects were inoculated with fixed doses of 35000HP (101 CFU or 130 CFU) at three sites on one arm and escalating doses of FX533 (range, 46 CFU to 915 CFU) at three sites on the other arm. Pustules only developed at mutant-injected sites at doses nearly twofold higher than that of the parent, suggesting that FX533 was partially attenuated. Three subjects were inoculated with similar doses of the parent (67 CFU) and mutant (104 CFU) at three sites. Pustules formed at five of nine parent sites and one of nine mutant sites. Overall, the papule and pustule formation rates for 35000HP and FX533 were similar for the trial. However, for the five subjects who received similar doses of the parent and mutant, pustules developed at 7 of 15 sites (46.7%; 95% confidence interval [CI], 16.9% to 76.5%) inoculated with the parent and at 1 of 15 (6.7%; 95% CI, 0.1% to 18.4%) sites inoculated with the mutant (P = 0.043). We concluded that the DltA mutant was attenuated in its ability to cause disease at doses similar to that of the parent.

Adolescent↗

Expression of Haemophilus ducreyi collagen binding outer membrane protein NcaA is required for virulence in swine and human challenge models of chancroid.

Haemophilus ducreyi, the etiologic agent of the sexually transmitted genital ulcer disease chancroid, has been shown to associate with dermal collagen fibers within infected skin lesions. Here we describe NcaA, a previously uncharacterized outer membrane protein that is important for H. ducreyi collagen binding and host colonization. An H. ducreyi strain lacking the ncaA gene was impaired in adherence to type I collagen but not fibronectin (plasma or cellular form) or heparin. The mutation had no effect on serum resistance or binding to HaCaT keratinocytes or human foreskin fibroblasts in vitro. Escherichia coli expressing H. ducreyi NcaA bound to type I collagen, demonstrating that NcaA is sufficient to confer collagen attachment. The importance of NcaA in H. ducreyi pathogenesis was assessed using both swine and human experimental models of chancroid. In the swine model, 20% of lesions from sites inoculated with the ncaA mutant were culture positive for H. ducreyi 7 days after inoculation, compared to 73% of wild-type-inoculated sites. The average number of CFU recovered from mutant-inoculated lesions was also significantly reduced compared to that recovered from wild-type-inoculated sites at both 2 and 7 days after inoculation. In the human challenge model, 8 of 30 sites inoculated with wild-type H. ducreyi progressed to the pustular stage, compared to 0 of 30 sites inoculated with the ncaA mutant. Together these results demonstrate that the collagen binding protein NcaA is required for H. ducreyi infection.

Adhesins, Bacterial↗

Associations between joint space narrowing and molecular markers of collagen and proteoglycan turnover in patients with knee osteoarthritis.

OBJECTIVE: We examined whether plasma concentrations of biomarkers of the collagenase cleavage of type II collagen (C2C), types I and II collagens (C1,2C), type II collagen synthesis (CPII), proteoglycan aggrecan turnover (CS846), and the ratio C2C:CPII would distinguish subjects with progressive radiographic osteoarthritis (OA) from those with stable disease. METHODS: Subjects were 120 obese middle-aged women with unilateral knee OA who participated in a 30-month clinical trial of structure modification with doxycycline, in which a standardized semiflexed anteroposterior view of the knee was obtained at baseline, 16 months, and 30 months. Subjects were selected from a larger sample to permit a priori comparisons between 60 OA progressors and 60 nonprogressors, as defined by joint space narrowing (JSN) in the medial tibiofemoral compartment. Each group contained 30 subjects who exhibited clinically significant increases in knee pain over 30 months and 30 who did not. Plasma samples were obtained every 6 months for determination of C2C, CPII, CS846, and C1,2C. RESULTS: None of the biomarkers was a significant predictor of progression of JSN. Over the interval from baseline to 16 months, the mean and the maximum of the intercurrent CS846 values were significantly associated with JSN (i.e., 0.12-0.14 mm of JSN per SD decrease in mean or maximum CS846; p < 0.01). The mean of serial CS846 levels was related to JSN also during the interval between months 16 and 30. CONCLUSION: Markers of type II collagen synthesis/degradation and of proteoglycan aggrecan turnover were not predictive of JSN in knee OA in this pilot study. However, serial concentrations of proteoglycan aggrecan epitope CS846 were associated with JSN during both the intervals studied.

Anti-Bacterial Agents↗

Effects of doxycycline on progression of osteoarthritis: results of a randomized, placebo-controlled, double-blind trial.

OBJECTIVE: To confirm preclinical data suggesting that doxycycline can slow the progression of osteoarthritis (OA). The primary outcome measure was joint space narrowing (JSN) in the medial tibiofemoral compartment. METHODS: In this placebo-controlled trial, obese women (n = 431) ages 45-64 years with unilateral radiographic knee OA were randomly assigned to receive 30 months of treatment with 100 mg doxycycline or placebo twice a day. Tibiofemoral JSN was measured manually in fluoroscopically standardized radiographic examinations performed at baseline, 16 months, and 30 months. Severity of joint pain was recorded at 6-month intervals. RESULTS: Seventy-one percent of all randomized subjects completed the trial. Radiographs were obtained from 85% of all randomized subjects at 30 months. Adherence to the dosing regimen was 91.8% among subjects who completed the study per protocol. After 16 months of treatment, the mean +/- SD loss of joint space width in the index knee in the doxycycline group was 40% less than that in the placebo group (0.15 +/- 0.42 mm versus 0.24 +/- 0.54 mm); after 30 months, it was 33% less (0.30 +/- 0.60 mm versus 0.45 +/- 0.70 mm). Doxycycline did not reduce the mean severity of joint pain, although pain scores in both treatment groups were low at baseline and remained low throughout the trial, suggesting the presence of a floor effect. However, the frequency of followup visits at which the subject reported a > or = 20% increase in pain in the index knee, relative to the previous visit, was reduced among those receiving doxycycline. In contrast, doxycycline did not have an effect on either JSN or pain in the contralateral knee. In both treatment groups, subjects who reported a > or = 20% increase in knee pain at the majority of their followup visits had more rapid JSN than those whose pain did not increase. CONCLUSION: Doxycycline slowed the rate of JSN in knees with established OA. Its lack of effect on JSN in the contralateral knee suggests that pathogenetic mechanisms in that joint were different from those in the index knee.

Anti-Infective Agents↗

Use of the plasma stromelysin (matrix metalloproteinase 3) concentration to predict joint space narrowing in knee osteoarthritis.

OBJECTIVE: To determine whether baseline or serial plasma concentrations of stromelysin (matrix metalloproteinase 3 [MMP-3]) protein might distinguish subjects with progressive radiographic knee osteoarthritis (OA) from those with stable disease. METHODS: Subjects were 120 women with unilateral knee OA who participated in a 30-month randomized, placebo-controlled trial of structure modification with doxycycline. Anteroposterior views of both knees in a semiflexed position were obtained at baseline, 16 months, and 30 months. Subjects were selected to obtain comparisons of plasma MMP-3 levels between 60 progressors (21 taking doxycycline, 39 taking placebo) and 60 nonprogressors (30 taking doxycycline, 30 taking placebo) with respect to medial joint space narrowing (JSN) in the index knee. Each group consisted of 30 subjects who exhibited significant increases in knee pain. Blood samples were obtained semiannually for MMP-3 assay. RESULTS: Subjects in the placebo group whose MMP-3 concentration was in the upper tertile of the baseline distribution showed a 4-fold increase in the odds of progression of JSN as compared with the lower tertile (odds ratio 4.12, P = 0.037). Baseline MMP-3 levels were unrelated to knee pain. The within-subject mean of serial MMP-3 concentrations was associated with concurrent JSN in the placebo group over the 0-16-month interval (b = 0.18 mm/SD increase in the mean MMP-3, P < 0.01) and over the 16-30-month interval (b = 0.15, P < 0.05). Similar evidence of concurrent validity was found in the placebo group for the maximum of intercurrent MMP-3 values. CONCLUSION: The baseline MMP-3 level was a significant predictor of JSN in this pilot study. Moreover, serial plasma MMP-3 levels reflected concurrent JSN in the placebo group over the 30-month period of observation.

Anti-Bacterial Agents↗

Daily mood, partner support, sexual interest, and sexual activity among adolescent women.

The main objective of this study was to examine day-to-day associations of coitus, sexual interest, partner emotional support, negative mood, and positive mood among adolescent women. Diaries assessed partner interactions, sexual activity, substance use, and mood. Participants were 146 adolescent women who provided 28,376 diary days. Correlates of coitus on a given day included age, increased coital frequency in previous week, coitus on the previous day, partner support, increased same-day sexual interest, and decreased same-day negative mood. The data demonstrate complex associations of sexual interest, mood, partner interactions, and sexual activity. The findings extend understanding of the sexuality of adolescent women and have implications for a variety of interventions to reduce sexually transmitted infections and unplanned pregnancies.

Adolescent↗

Pelvic inflammatory disease during the post-partum year.

OBJECTIVE: To investigate the occurrence of, and risk factors for, pelvic inflammatory disease (PID) occurring during the post-partum year. METHODS: Demographic and clinical data for women who delivered a term infant with 5-minute Apgar score > or = 8 from 1992 through 1999 at a large urban hospital were extracted from an electronic medical record system. RESULTS: During the study period, 15 206 deliveries occurred among 12 549 women. PID was diagnosed during the post-partum year of 148 (1.0%) deliveries. In univariate analysis, young age, black race, and both pre-delivery history and post-partum diagnosis of chlamydial and gonococcal infection were associated with PID. In multivariate analysis, only young age and a positive test for gonorrhea before delivery or post-partum were independent predictors of PID. CONCLUSIONS: Pelvic inflammatory disease was diagnosed during the post-partum year in 1% of women studied. Young maternal age was an important demographic risk factor. Further investigation of post-partum STD acquisition and progression to PID is needed to determine whether women are at increased risk following delivery.

Chlamydia Infections↗

Indiana chronic disease management program risk stratification analysis.

OBJECTIVE: The objective of this study was to compare the ability of risk stratification models derived from administrative data to classify groups of patients for enrollment in a tailored chronic disease management program. SUBJECTS: This study included 19,548 Medicaid patients with chronic heart failure or diabetes in the Indiana Medicaid data warehouse during 2001 and 2002. MEASURES: To predict costs (total claims paid) in FY 2002, we considered candidate predictor variables available in FY 2001, including patient characteristics, the number and type of prescription medications, laboratory tests, pharmacy charges, and utilization of primary, specialty, inpatient, emergency department, nursing home, and home health care. METHODS: We built prospective models to identify patients with different levels of expenditure. Model fit was assessed using R statistics, whereas discrimination was assessed using the weighted kappa statistic, predictive ratios, and the area under the receiver operating characteristic curve. RESULTS: We found a simple least-squares regression model in which logged total charges in FY 2002 were regressed on the log of total charges in FY 2001, the number of prescriptions filled in FY 2001, and the FY 2001 eligibility category, performed as well as more complex models. This simple 3-parameter model had an R of 0.30 and, in terms in classification efficiency, had a sensitivity of 0.57, a specificity of 0.90, an area under the receiver operator curve of 0.80, and a weighted kappa statistic of 0.51. CONCLUSION: This simple model based on readily available administrative data stratified Medicaid members according to predicted future utilization as well as more complicated models.

Adult↗

Severity of joint pain and Kellgren-Lawrence grade at baseline are better predictors of joint space narrowing than bone scintigraphy in obese women with knee osteoarthritis.

OBJECTIVE: To compare the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of a baseline late-phase bone scan and assessments of the radiographic and symptomatic severity of knee osteoarthritis (OA) at baseline as predictors of loss of articular cartilage thickness, as reflected in joint space narrowing (JSN) in the medial tibiofemoral compartment. METHODS: Subjects (174 obese women, 45-64 yrs of age, with unilateral knee OA) were a subset of a larger cohort who participated in a placebo controlled trial of a disease modifying OA drug. Uptake of technetium medronate (99mTc-MDP) in anteroposterior (AP) and lateral views of a late-phase bone scan was measured at baseline in a region of interest drawn around the medial tibia, and was adjusted for (i.e., expressed as a ratio to) uptake in a reference segment of the tibial shaft, which served as an internal standard. Each subject underwent a fluoroscopically standardized radiographic examination of the knees (semiflexed AP view) and a pain assessment with the WOMAC OA Index at baseline, 16 months, and 30 months. RESULTS: Controlling for baseline joint space width and treatment group, multiple linear regression models showed that the adjusted 99mTc-MDP uptake at baseline was a significant predictor of joint space narrowing (JSN) in the index knee at 16 months (b = 0.180, p = 0.015) and 30 months (b = 0.221, p = 0.049). In the contralateral knee, uptake was only a marginally significant predictor of JSN at 30 months (b = 0.246, p = 0.083). Uptake in the upper and middle tertiles of the distribution predicted subjects who would exhibit JSN >/= 0.50 mm within 16 months with 65% sensitivity (PPV 23%) and 36% specificity (NPV 77%). In contrast, a prediction rule based solely on the presence of Kellgren-Lawrence grade 3 OA severity and greater than median WOMAC Pain score identified progressors with 65% sensitivity (PPV 48%) and 79% specificity (NPV 88%). CONCLUSION: Although the level of adjusted 99mTc-MDP uptake was significantly associated with JSN in knees with established radiographic OA, baseline bone scintigraphy is inferior to the radiographic severity of OA and knee pain (alone or in combination) as a predictor of loss of articular cartilage in subjects with knee OA.

Aged↗

Subject retention and adherence in a randomized placebo-controlled trial of a disease-modifying osteoarthritis drug.

OBJECTIVE: To describe the methods by which remarkable levels of subject retention and adherence were achieved in a 30-month multicenter randomized placebo-controlled trial (RCT) of a disease-modifying osteoarthritis drug (DMOAD). METHODS: Subjects were obese 45-64-year-old women with unilateral knee osteoarthritis. Before randomization, each volunteer completed a 4-week "faintness-of-heart" (FOH) test, during which she was required to demonstrate reliable appointment keeping and > or =80% adherence to the dosing regimen. Subjects who passed the FOH test were randomized to treatment with doxycycline or placebo for 30 months. The double-blind phase entailed 15 bimonthly followup visits; intervisit adherence data were downloaded from the dosing monitor and used to estimate therapeutic coverage and to identify correctable patterns of nonadherence. Subjects received token incentives and a small cash payment at each followup visit. Measures to prevent or treat side effects of doxycycline were dispensed free of charge. Study coordinators monitored safety and reinforced participation through between-visit telephone calls. RESULTS: Of 463 eligible volunteers, 32 (7%) failed the FOH test and were excluded from the double-blind phase. Among the 431 subjects randomized to treatment groups, 307 (71%) completed the 30-month RCT and 124 discontinued the study drug prematurely. Nearly half of the dropouts returned for their 16- and 30-month radiographs, resulting in loss to followup of 14.8% of randomized subjects. The 2 treatment groups did not differ significantly with respect to rates of discontinuation or retention. Therapeutic coverage over 30 months was very high in both groups. CONCLUSION: The rate of discontinuation in this 30-month RCT (29%) was lower than that of any DMOAD trial of > or =2 years duration published to date. The proportion of subjects for whom 30-month radiographs were available (85%) and adherence to the dosing regimen (mean >80%) also were remarkably high.

Antirheumatic Agents↗

Can a nurse-directed intervention reduce the exposure of patients with knee osteoarthritis to nonsteroidal antiinflammatory drugs?

OBJECTIVE: : The objective of this study was to evaluate a nurse-directed self-management intervention for managed care patients with knee osteoarthritis (OA), emphasizing nonpharmacologic (NonPharm) management of pain and functional impairments and minimization of exposure to the risks and costs of nonsteroidal antiinflammatory drugs (NSAIDs). METHODS: : Subjects were 186 patients from a large health maintenance organization (HMO) who satisfied American College of Rheumatology clinical criteria for knee OA. Two of 4 HMO sites (and their patient cohorts) were randomly assigned to the education group; the other 2 served as a delayed-intervention control group. At each location of care for the education group, an arthritis nurse educator, in consultation with the patient's primary care physician (PCP), followed a detailed algorithm for implementing and monitoring the response to NonPharm treatment modalities (eg, quadriceps strengthening exercises, counseling in principles of joint protection, use of thermal modalities). The nurses apprised the PCP of the patient's progress and made algorithm-based recommendations, as appropriate, for reduction of dose, and eventual discontinuation, of NSAIDs in favor of acetaminophen. Outcomes (measured at baseline, 3, 6, and 12 months) included pain and function scales from the Western Ontario and McMaster Universities (WOMAC) OA Index. RESULTS: : The treatment groups were similar at baseline with respect to sociodemographic and clinical characteristics. Medical record audits revealed that NonPharm treatments (most often exercise) were implemented by 75% of patients in the education group but by only 18% of patients receiving routine care (P < 0.00001). Over the subsequent 12 months, 20 patients (26%) in the education group, but only 3 (5%) in the control group (P = 0.002), underwent changes in drug treatment of OA pain consistent with the NSAID-sparing goals of the intervention, ie, acetaminophen as initial drug of choice; reduction in dose, or discontinuation, of NSAID; switch from an NSAID to an analgesic. Only one patient in the education group required reinstitution of NSAIDs because of an increase in knee pain. Mean WOMAC scores indicated no deterioration of pain control or function over 12 months in the group treated according to the algorithm. CONCLUSION: : Incorporation into the primary care setting of self-care education for patients with knee OA, with collaboration between a proactive arthritis nurse and the patient's PCP, can reduce reliance on NSAIDs without a resultant increase in OA pain and disability.

Journal Article↗

Expression of the LspA1 and LspA2 proteins by Haemophilus ducreyi is required for virulence in human volunteers.

Haemophilus ducreyi colocalizes with polymorphonuclear leukocytes and macrophages and evades phagocytosis during experimental infection of human volunteers. H. ducreyi contains two genes, lspA1 and lspA2, which encode predicted proteins of 456 and 543 kDa, respectively. Compared to its wild-type parent, an lspA1 lspA2 double mutant does not inhibit phagocytosis by macrophage and myelocytic cell lines in vitro and is attenuated in an experimental rabbit model of chancroid. To test whether expression of LspA1 and LspA2 was necessary for virulence in humans, six volunteers were experimentally infected. Each volunteer was inoculated with three doses (ranging from 85 to 112 CFU) of the parent (35000HP) in one arm and three doses (ranging from 60 to 822 CFU) of the mutant (35000HP Omega 12) in the other arm. The papule formation rates were 88% (95% confidence interval [95% CI], 76.8 to 99.9%) at 18 parent sites and 72% (95% CI, 44.4 to 99.9%) at 18 mutant sites (P = 0.19). However, papules were significantly smaller at mutant sites (mean size, 24.8 mm(2)) than at parent sites (mean size, 39.1 mm(2)) 24 h after inoculation (P = 0.0002). The pustule formation rates were 44% (95% CI, 5.8 to 77.6%) at parent sites and 0% (95% CI, 0 to 39.4%) at mutant sites (P = 0.009). With the caveat that biosafety regulations preclude testing of a complemented mutant in human subjects, these results indicate that expression of LspA1 and LspA2 facilitates the ability of H. ducreyi to initiate disease and to progress to pustule formation in humans.

Adolescent↗

Syphilis testing in association with gonorrhea/chlamydia testing during a syphilis outbreak.

We used an electronic medical records system retrospectively to evaluate how frequently, in a public hospital and its clinics, combined gonorrhea/chlamydia tests were accompanied by a syphilis test before and during a syphilis outbreak. Among 70,330 gonorrhea/chlamydia tests (1996-2000), the proportion with a syphilis test increased from 13% (preoutbreak) to 50% (intervention period) for men and from 6% to 13% for nonpregnant women. The increased syphilis testing coincided with a multifaceted public health intervention.

Adult↗

Bone scintigraphy is not a better predictor of progression of knee osteoarthritis than Kellgren and Lawrence grade.

OBJECTIVE: To determine the predictive value of bone scintigraphy with respect to joint space narrowing (JSN) in patients with knee osteoarthritis (OA), based on quantitative estimates of uptake of a bone-seeking radiopharmaceutical and fluoroscopically standardized knee radiography. METHODS: Our study group included 86 obese women, 45-64 years of age, with unilateral knee OA. Uptake of technetium medronate (99mTc-MDP) in late-phase bone scans was measured at baseline in 5 regions of interest (ROI: lateral femur, lateral tibia, medial femur, medial tibia, and patellofemoral joint) and was adjusted for uptake (i.e., expressed as a ratio to uptake) in a ROI in the shaft of the tibia, which served as an internal standard. Each subject underwent a fluoroscopically standardized radiograph of the knees (semiflexed anteroposterior view) at baseline, 16, and 30 months. Magnification-corrected minimum joint space width in the medial tibiofemoral compartment was measured by digital image analysis. RESULTS: Followup was available for 79 patients (92%) at 16 months and from 73 patients (85%) at 30 months. On average, 99mTc-MDP uptake in each ROI and in the whole knee (average of 4 tibiofemoral ROI) was 170-240% of that in the tibial shaft. Uptake in the medial tibia and in the whole knee was significantly correlated with JSN at 16 and 30 months (r = 0.22-0.30, p < 0.05). However, after controlling for age, body mass index, and radiographic severity of OA, the associations between adjusted uptake and JSN were not significant. The rate of JSN in knees of patients with OA who were in the lower tertile with respect to adjusted 99mTc-MDP uptake in the medial tibia was significantly less rapid than in patients in whom uptake was in the middle and upper tertiles (0.04 mm/yr vs 0.18 mm/yr; p < 0.05). However, after controlling for overall radiographic severity at baseline, the difference in 30-month JSN in knees of patients with OA in the lower versus middle/upper tertiles was not significant. CONCLUSION: The predictive utility of bone scintigraphy is confirmed by these data. However, its practical value is considerably diminished, insofar as similarly predictive information may be obtained by routine radiographic examination, without the radiation exposure and cost of scintigraphy.

Cartilage, Articular↗