Susceptibility to levofloxacin of Myocobacterium tuberculosis isolates from patients with HIV-related tuberculosis and characterization of a strain with levofloxacin monoresistance. Community Programs for Clinical Research on AIDS 019 and the AIDS Clinical Trials Group 222 Protocol Team.

OBJECTIVE: To characterize the susceptibility to levofloxacin of clinical isolates of Mycobacterium tuberculosis (MTB) obtained from patients with HIV-related tuberculosis and to characterize the molecular genetics of levofloxacin resistance. DESIGN AND METHODS: Isolates from culture-positive patients in a United States multicenter trial of HIV-related TB were tested for susceptibility to levofloxacin by minimum inhibitory concentration (MIC) determinations in Bactec 7H12 broth. Automated sequencing of the resistance determining region of gyrA was performed. RESULTS: Of the 135 baseline MTB isolates tested, 134 (99%; 95% exact binomial confidence interval, 95.9-99.9%) were susceptible to levofloxacin with an MIC < or = 1.0 microg/ml. We identified a previously unrecognized mis-sense mutation occurring at codon 88 of gyrA in a levofloxacin mono-resistant MTB isolate obtained from a patient with AIDS who had received ofloxacin for 8 months prior to the diagnosis of tuberculosis. CONCLUSIONS: Clinical MTB isolates from HIV-infected patients were generally susceptible to levofloxacin. However, the identification of a clinical isolate with mono-resistance to levofloxacin highlights the need for circumspection in the use of fluoroquinolones in the setting of potential HIV-related tuberculosis and for monitoring of rates of resistance of MTB isolates to fluoroquinolones.

Predictors for multidrug-resistant tuberculosis among HIV-infected patients and response to specific drug regimens. Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA) and the AIDS Clinical Trials Group (ACTG), National Institutes for Health.

SETTING: Mortality associated with human immunodeficiency virus (HIV) related multidrug-resistant tuberculosis (MDR-TB) is reduced with effective early therapy. Identifying predictors of, and effective regimens for, MDR-TB is critical. OBJECTIVE: A multicenter prospective study was initiated to 1) determine the demographic, behavioral, clinical and geographic risk factors associated with the occurrence of MDR-TB among HIV-infected patients, and 2) to evaluate the overall survival and clinical response of MDR-TB patients treated with specific drug regimens. METHODS: Patients were prospectively evaluated for MDR-TB. Information included history of prior treatment for tuberculosis, close contact with a known case of MDR-TB, and residence in a facility with known or suspected MDR-TB transmission. Patients with known MDR-TB, or those suspected to be at high risk, were offered enrollment in a treatment pilot study. Study drugs included levofloxacin and at least two additional drugs to which the patient's isolate was known, or most likely, to be susceptible. Survival was the primary endpoint. RESULTS: Complete data are available for 156 HIV-infected patients with confirmed tuberculosis. Sixteen (10%) had MDR-TB. Only a history of prior tuberculosis treatment was associated with MDR-TB in multivariate analysis (OR = 4.4, P < 0.02). Twelve patients with MDR-TB enrolled in the treatment pilot had a median CD4 cell count of 51/mm3. The cumulative probability of survival at one year was 75% (95% CI 50.5-99.5) and at 18 months, 65.6% (95% CI 38.1-93.1). Toxicity requiring discontinuation of medications occurred in two patients. CONCLUSIONS: A history of treatment for tuberculosis was the only predictor for MDR-TB in a cohort of HIV-infected patients with tuberculosis. In addition, this prospective study supports the results of prior retrospective studies that effective treatment impacts on mortality. Current second-line treatment, including high dose levofloxacin, appears to be reasonably well tolerated.

Evolution of trends in the live kidney transplant donor-recipient relationship.

OBJECTIVE: This study examined the changing demographics and age profile between living donors and their recipients. A 46-year review of living donor renal transplants in a single transplant center was performed. PATIENTS: The study included 923 consecutive living donor renal transplants from January 1966 until December 2011. RESULTS: These 923 living donor kidneys transplants represent 41% of all transplants performed during this 46-year review. The majority involved sibling donation (39.5%) followed by parent to child (32.5%). Dividing the 46-year timeframe into quartiles, the mean age of donors has remained stable at 39.3 ± 10.9 years. In contrast, the mean age of recipients has trended upwards, from 28 ± 10.7 years in the first quartile (1966-1978) to 37 ± 17.5 years in the latest quartile (2001-2011). This represents an increase every year of approximately 4 months (P < .001). Over the same period, the difference between a given donor's age and their recipient's has decreased every year by approximately 4 months (P < .001). In a linear regression model of donor-recipient categories and their age difference over time, we found that both the child-to-parent and grandchild-to-grandparent groups had the largest effect on the donor-recipient age difference when compared to the classic parent-to-child relationship. CONCLUSION: This review of center-specific data shows that the difference in the age of the donor to their recipient has been narrowing over time. We have determined that this is primarily due to changes in donor-recipient demographics with an increasing number of younger donors to older recipients. Although the medical risks to donors living with a single kidney have yet to be shown different than that of the general population, the increasing volume of donors who are younger and those with no relation to the recipient should prompt closer follow-up within the transplantation medical community.

Phospholipase activity in bacteriophage-infected Escherichia coli. I. Demonstration of a T4 bacteriophage-associated phospholipase.

Phospholipase activity has been found to be associated with T4 phage and T4 ghost particles. The attachment of the phospholipase to the phage persists during purification through cesium chloride gradients and dialysis, indicating that it is firmly bound. The presence of the enzymatic activity on T4 ghosts suggests that it is not normally packaged within the head of the virus. The enzyme has specificity for phosphatidylglycerol and its activity is stimulated by 0.1% Triton X-100 and 20% methanol. It does not have a requirement for Ca(2+) and is inactivated at temperatures above 60 C. The association of the phospholipase with T4 phage grown in a phospholipase-deficient host and its absence on unsuppressed T4amtA3 suggests that it may be phage gene specific.

Visible absorption spectrum of liquid ethylene.

The visible absorption spectrum of liquid ethylene at approximately 108 K from 5500 A to 7200 A was measured by using a pulsed tunable dye laser, immersed-transducer, gated-detection opto-acoustic spectroscopy technique. The absorption features show the strongest band with an absorption coefficient of approximately 2 x 10(-2) cm(-1) and the weakest band with an absorption coefficient of approximately 1 x 10(-4) cm(-1). Proposed assignments of the observed absorption peaks involve combinations of overtones of local and normal modes of vibration of ethylene.

Response of piezoelectric transducers used in pulsed optoacoustic spectroscopy.

A general scaling relationship is derived for detector sensitivity in terms of the acoustic properties of the absorber, permitting the transfer of calibration among different materials. A limiting case of an exciting optical-pulse duration's being short compared with acoustic relaxation time is considered in detail. A strong temperature dependence of the detector response is predicted for several materials of technical interest.

Comparison of the presence-absence and membrane filter techniques for coliform detection in small, nonchlorinated water distribution systems.

The traditional membrane filter (American Public Health Association, Standard Methods for the Examination of Water and Wastewater, 16th ed., American Public Health Association, Washington, D.C., 1985) and presence-absence (P-A) (J. A. Clark, Can. J. Microbiol. 14:13-18, 1968) techniques for the detection of coliform bacteria were compared in a small nonchlorinated drinking water distribution system by using total positive samples and frequency-of-occurrence analyses. No significant differences (P less than 0.05) were found in detection of the presence of coliform bacteria or in changes in the frequency of occurrence with time. A reduction in P-A sample volume (to 50 ml) was not found to statistically affect the comparative results of traditional membrane filter and P-A tests.

Vibrio cholerae adherence and colonization in experimental cholera: electron microscopic studies.

Colonization of the intestinal epithelium by Vibrio cholerae was examined in two model systems, in ligated ileal loops of adult rabbits and in the patent gut of infant rabbits, using both scanning and transmission electron microscopy. Time studies in the adult model showed a lag period of up to 1 h before the attachment of significant numbers of the vibrios. The bacteria appeared initially in small patches on the sides of the villi, predominantly along the transverse furrows. The number of adherent bacteria steadily increased, reaching a maximum between 4 and 7 h, when a dense mat of bacteria several layers thick covered much of the villi. After this time there was a rapid decline in the number of V. cholerae bound. By 12 to 16 h only a few bacteria could be seen on the surface of the villi, which had a rough, patchy appearance at these later times. Globular protrusions, with vibrios attached, may play a role in the clearance of bacteria. Colonization and clearance in the patent intestine of the infant rabbit occurred much as in the adult model. However, the bacteria adhered more uniformly and there was no lag in attachment. In both models the majority of bacteria were aligned horizontally with the epithelial surface, but some were attached in an end-on manner, with their flagella extending into the lumen. The bacteria adhered via their surface coats directly to the tips of the microvilli, except for a few vibrios that were partly embedded into the brush border. Some changes in the microvilli occurred as a consequence of the bacterial attachment.

Does phospholipase have a role in killing and sodium dodecyl sulfate lysis of T4 ghost-infected Escherichia coli?

The activation of Escherichia coli phospholipase by T4 ghost attachment was shown not to have a significant role in the killing or in the increased sensitivity of the bacterial cells to lysis by sodium dodecyl sulfate.

A graphical assessment of the potential impact of losses to follow-up on the validity of study results. The Terry Beirn Community Programs for Clinical Research on AIDS.

Losses to follow-up in clinical trials-patients for whom we do not know if the outcome of interest has occurred-can bias study results. If we investigate extreme case scenarios and find the study results do not change much, impact is negligible. If not, we may need to interpret the study's results with caution. At issue is how much caution do we need? We describe a graphical approach to assess the potential impact of losses to follow-up on the validity of study results. One can create the graphs using design estimates and interim or final data. We give two examples using design parameters and another example modelled after observed data from clinical trials conducted by the Terry Beirn Community Programs for Clinical Research on AIDS. The examples illustrate that tolerable levels of losses to follow-up change depending on the overall outcome and direction of differential losses.

Are race and sex differences in lung function explained by frame size? The CARDIA Study.

Using the CARDIA cohort of 20- to 32-yr-old black and white men and women, FVC and FEV1 were standardized for standing height, sitting height, leg height, elbow breadth, and biacromial diameter in such a way that the standardized lung function showed minimal statistical dependence on these measures of frame size. Race and sex differences in lung function have been reported even after adjustment for height; however, these differences might depend on aspects of frame size other than height. We found that within this age group height2 provided robust standardization for FVC and FEV1 for all race and sex strata of the population. Height explained approximately 40% of the variance of FVC and FEV1 in whites, 30% in black women, and 20% in black men. In black men only, standardization for the combination of sitting height, leg height, elbow breadth, and biacromial diameter improved explained variance to nearly 40% for FVC and nearly 30% for FEV1. After standardization for height, FVC and FEV1 were found to be 14 to 19% higher in whites than in blacks, and in men than in women. Standardization of FVC and FEV1 for sitting height, leg height, elbow breadth, and biacromial diameter combined reduced these differences to 13-16%. Thus, race and sex differences in lung function exist even after detailed adjustment for frame size.

Anthropometric predictors of coronary heart disease and total mortality: findings from the US Railroad Study.

Prospective data from the US Railroad Study were used to investigate the relations of several anthropometric variables to coronary heart disease and all-cause mortality in males initially free of cardiovascular disease. Middle-aged men were examined in 1957-1960 and followed until 1977 or death. Anthropometric indicators of total body fat (body mass index and the sum of the subscapular and triceps skinfolds) and central body fat (the ratios chest circumference/biacromial (shoulder) diameter, and chest circumference/standing height) were significantly and directly associated with age-adjusted coronary heart disease mortality. When systolic blood pressure, serum cholesterol, cigarette smoking, and vital capacity were also taken into account, the ratio chest circumference/biacromial diameter remained significantly associated with coronary heart disease mortality. Total, central, and peripheral body fat had a "U"-shaped relation with all-cause mortality. Measures of the ratio of central to peripheral body fat were inconsistently related to mortality. These results indicate that certain anthropometric measurements, especially those that may indicate central adiposity, are positively related to the development of fatal coronary heart disease and quadratically related to all-causes death rates.

Variation of chest radiographic patterns in pulmonary tuberculosis by degree of human immunodeficiency virus-related immunosuppression. The Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA). The AIDS Clinical Trials Group (ACTG).

Our aim was to evaluate the effect of human immunodeficiency virus (HIV) disease stage on chest radiographic (CXR) findings among patients with HIV-related pulmonary tuberculosis (TB). Data are from a prospective multicenter treatment trial for HIV-related TB. Baseline CXR findings and CD4+ lymphocyte counts were compared among patients with HIV-related TB. Data from published studies describing CXR findings in HIV-infected patients were reviewed and a pooled-data analysis was conducted. Of 135 patients with culture-confirmed HIV-related TB, 128 had both CXR and CD4+ lymphocyte data. CD4+ lymphocyte counts of < 200/mm3 (n = 98) were significantly associated with hilar/mediastinal adenopathy on CXR (30%, vs. 7% with counts > or = 200/mm3; P = .01); counts of > or = 200/mm3 (n = 30) more frequently were associated with cavitation (20% vs. 7%; P = .08). Analyses of these results, pooled with other published data, confirmed these findings. This study demonstrates associations of certain CXR findings with HIV disease stage. Knowledge of the degree of immunosuppression is important when evaluating CXR findings in HIV-infected patients.

The impact of human immunodeficiency virus infection on drug-resistant tuberculosis.

Infection with human immunodeficiency virus (HIV) has been associated with increased rates of single- and multidrug-resistant (MDR) tuberculosis in the New York City area. In order to examine the relationship of HIV infection to drug-resistant tuberculosis in other selected regions of the United States, we established a registry of cases of culture-proven tuberculosis. Data were collected from sites participating in an NIH-funded, community-based HIV clinical trials group. All cases of tuberculosis, regardless of HIV status, which occurred between January 1992 and June 1994 were recorded. Overall, 1,373 cases of tuberculosis were evaluated, including 425 from the New York City area, and 948 from seven other metropolitan areas. The overall prevalence of resistance to one or more drugs was 20.4%, and 5.6% of isolates were resistant to both isoniazid and rifampin (MDR). In the New York City area, HIV-infected patients were significantly more likely than persons not known to be HIV-infected, to have resistance to at least one drug (37% versus 19%) and MDR (19% versus 6%). In other geographic areas, overall drug resistance was 16%, and only 2.2% of isolates were MDR. In multiple logistic regression analyses, HIV infection was shown to be a risk factor for drug-resistant tuberculosis, independent of geographic location, history of prior therapy, age, and race. We concluded that HIV infection is associated with increased rates of resistance to antituberculosis drugs in both the New York City area and other geographic areas. MDR tuberculosis is occurring predominantly in the New York City area and is highly correlated with HIV infection.

Evaluation of an intensive intermittent-induction regimen and duration of short-course treatment for human immunodeficiency virus-related pulmonary tuberculosis. Terry Beirn Community Programs for Clinical Research on AIDS (CPCRA) and the AIDS Clinical Trials Group (ACTG).

This study examined whether adding levofloxacin to a standard four-drug regimen improved the 8-week culture response and compared effectiveness of 9 versus 6 months of intermittent therapy for human immunodeficiency virus-related pansusceptible pulmonary tuberculosis. Patients were randomized to receive either four or five drugs, the fifth being levofloxacin. Patients who completed induction therapy were randomized to complete 9 versus 6 months of intermittent therapy with isoniazid and rifampin. In the randomized induction phase, 97.3% of patients in the four-drug group and 95.8% in the five-drug group had sputum culture conversion at 8 weeks (P = 1.00). In the continuation phase, one patient (2%) assigned to 9 months and two patients (3.9%) assigned to 6 months of therapy had treatment failure/relapse (P = 1.00). In conclusion, this study showed that levofloxacin added no benefit to a highly effective, largely intermittent, four-drug induction regimen. Both 9 and 6 months of intermittent therapy were associated with low treatment failure/relapse rates.