Avasopasem manganese (GC4419) protects against cisplatin-induced chronic kidney disease: An exploratory analysis of renal metrics from a randomized phase 2b clinical trial in head and neck cancer patients.

Head and neck squamous cell carcinoma (HNSCC) patients treated with high-dose cisplatin concurrently with radiotherapy (hdCis-RT) commonly suffer kidney injury leading to acute and chronic kidney disease (AKD and CKD, respectively). We conducted a retrospective analysis of renal function and kidney injury-related plasma biomarkers in a subset of HNSCC subjects receiving hdCis-RT in a double-blinded, placebo-controlled clinical trial (NCT02508389) evaluating the superoxide dismutase mimetic, avasopasem manganese (AVA), an investigational new drug. We found that 90 mg AVA treatment prevented a significant reduction in estimated glomerular filtration rate (eGFR) three months as well as six and twelve months after treatment compared to 30 mg AVA and placebo. Moreover, AVA treatment may have allowed renal repair in the first 22 days following cisplatin treatment as evidenced by an increase in epithelial growth factor (EGF), known to aid in renal recovery. An upward trend was also observed in plasma iron homeostasis proteins including total iron (Fe-blood) and iron saturation (Fe-saturation) in the 90 mg AVA group versus placebo. These data support the hypothesis that treatment with 90 mg AVA mitigates cisplatin-induced CKD by inhibiting hdCis-induced renal changes and promoting renal recovery.

Value of Mycobacterium tuberculosis fingerprinting as a tool in a rural state surveillance program.

OBJECTIVE: This study demonstrates the value of Mycobacterium tuberculosis fingerprinting used in conjunction with traditional epidemiologic methods to identify smoldering outbreaks of tuberculosis in endemic areas where background rates of tuberculosis are high. METHODS: IS6110 DNA fingerprinting was performed on isolates of M tuberculosis from verified cases of tuberculosis in Alabama from 1994 to 1998. A statewide database groups isolates into "clusters" and tracks them cumulatively over time. A large cluster was identified and was secondarily investigated using traditional epidemiologic methods. RESULTS: Twenty-five isolates were found to be identical by fingerprinting analysis. Patients were living within 10 counties across the state, and 12 cases were localized to a single county. This represented an ongoing, statewide tuberculosis outbreak previously unrecognized by local and state health officials. Secondary investigation of the cases revealed the primary sites of transmission to be a correctional facility and two homeless shelters. CONCLUSIONS: Population surveillance using M tuberculosis fingerprinting was successfully utilized to detect a significant and smoldering tuberculosis outbreak. Measures are currently in place to identify and prevent further transmission in the involved locations.

Identification of a contaminating Mycobacterium tuberculosis strain with a transposition of an IS6110 insertion element resulting in an altered spoligotype.

Molecular fingerprinting with the IS6110 insertion sequence is useful for tracking transmission of Mycobacterium tuberculosis within a population or confirming specimen contamination in the laboratory or through instrumentation. Secondary typing with other molecular methods yields additional information as to the relatedness of strains with similar IS6110 fingerprints. Isolated, relatively rare, random events within the M. tuberculosis genome alter molecular fingerprinting patterns with any of the methods; therefore, strains which are different by two or more typing methods are usually not considered to be closely related. In this report, we describe two strains of M. tuberculosis, obtained from the same bronchoscope 2 days apart, that demonstrated unique molecular fingerprinting patterns by two different typing methods. They were closely linked through the bronchoscope by a traditional epidemiologic investigation. Genetic analysis of the two strains revealed that a single event, the transposition of an IS6110 insertion sequence in one of the strains, accounted for both the differences in the IS6110 pattern and the apparent deletion of a spacer in the spoligotype. This finding shows that a single event can change the molecular fingerprint of a strain in two different molecular typing systems, and thus, molecular typing cannot be the only means used to track transmission of this organism through a population. Traditional epidemiologic techniques are a necessary complement to molecular fingerprinting so that radical changes within the fingerprint pattern can be identified.

Preventable childhood tuberculosis in Alabama: implications and opportunity.

UNLABELLED: Childhood tuberculosis (TB) cases indicate recent community transmission and thus reflect the effectiveness of TB control efforts, particularly the contact investigation. OBJECTIVE: To evaluate all preventable childhood TB cases and implications in the context of TB morbidity trends. DESIGN: Statewide morbidity trends are presented from 1983 to 1997. Since 1992, each child TB case is classified as either preventable or not preventable, based on a standard definition. MAIN OUTCOME MEASURES: Case characteristics (preventable and not preventable), TB disease rates over time, and reasons for preventable case classification. SETTING: Alabama TB control program, from January 1, 1983 through December 31, 1997. RESULTS: For the period 1983-1997, nonwhite children had a higher disease rate (rate ratio: 5.7; 95% confidence interval: 4.3,7.6) than white children. Since 1990, the overall child rate has increased significantly despite a decline in the adult rate. Among 120 child cases diagnosed from 1992 to 1997, 25 (21%) were classified as preventable. The causes were contact investigation interview failure (12/25 = 48%), delay to evaluation (16%), source case noncompliance with previously prescribed preventive therapy (16%), and source case diagnosed out of state (16%) with no initial investigation performed in Alabama. All preventable cases identified were black children; the proportion of preventable cases did not vary by age group or sex. During 1996, the case rate for nonwhite children exceeded that of adult whites. CONCLUSIONS: Childhood TB in Alabama for nonwhites is rising despite a national downward trend. TB is clearly a disproportionate disease burden for the state's African American population, and the median case age is falling. Additional research and improved training in contact investigation are required to assess this situation and effectively intervene.

Spot sputum screening: evaluation of an intervention in two homeless shelters.

SETTING: Two homeless shelters in Birmingham, Alabama. OBJECTIVE: To interrupt tuberculosis transmission and evaluate the utility of spot sputum screening. DESIGN: Two shelters participated in the study between May 1996 and February 1997. A spot sputum specimen was collected on a given evening from each overnight client. Information was obtained regarding symptoms and tuberculin skin test (TST) status. There were four screenings during two rounds, with TST in round one only. RESULTS: Of 127 persons involved in the study, 120 (95%) provided specimens, and four tuberculosis cases were identified (4/127, 3.1%). Symptoms were infrequently reported. RFLP analysis (IS6110) confirmed a two-band cluster in three of the four cases; another matching two-band strain was found in a drug rehabilitation client staying in one shelter. Secondary RFLP typing (pTBN12) confirmed the homeless cluster. Costs were $1311 per case identified. Among 92 clients with a prior TST, 40% reported a positive result (37/92). Of 21 PPD tests read, 11 were > or =10 mm (52%). CONCLUSION: Spot sputum screening is effective in identifying unsuspected tuberculosis cases in shelters. It has acceptable costs, is logistically simple and efficient. Symptom screening was not useful in this general homeless population. RFLP analysis showed cloning of the two-band strain. Given the evidence for ongoing transmission, sputum screening should be considered in shelter settings.

In vitro evidence of two-component system phosphorylation between the Mycobacterium tuberculosis TrcR/TrcS proteins.

Two-component regulatory proteins, histidine kinases and response regulators, function in bacteria as sensing and adaptive factors in response to a wide range of environmental stimuli. Conserved histidine and glycine regions of histidine kinase sensor proteins were used to design degenerate oligonucleotide primers for amplification of DNA fragments from Mycobacterium tuberculosis. Two adjacent genes, trcR and trcS, which encode a response regulator and a histidine kinase, respectively, have been identified. Full-length and truncated TrcR and TrcS proteins have been expressed in Escherichia coli. Difficulties in expressing recombinant full-length TrcS and a truncated N -terminal form of TrcS reveal that the transmembrane domains are toxic to E. coli. Overexpressed truncated C-terminal transmitter domains of TrcS have been autophosphorylated in vitro and have transphosphorylated both the full-length recombinant TrcR protein and the N -terminal receiver/regulator domain of TrcR. In vitro autophosphorylation of TrcS requires the presence of Mn2+or Ca2+as a divalent cation cofactor and subsequent transphosphorylation of TrcR is evident in the presence of TrcS-phosphate and Ca2+. Transphosphorylation between these two proteins provides evidence that these M. tuberculosis genes encode functional two-component system regulatory proteins that are members of a signal transduction circuit.

Restriction fragment length polymorphism screening of Mycobacterium tuberculosis isolates: population surveillance for targeting disease transmission in a community.

SETTING: Alabama State Tuberculosis Control Program, USA. OBJECTIVE: To combine molecular screening data with routine information to assess transmission of Mycobacterium tuberculosis and improve control efforts. DESIGN: Since January 1994, samples from tuberculosis cases statewide have been systematically analyzed by IS6110 restriction fragment length polymorphism (RFLP). All cases during 1994-1995 with a predominate RFLP pattern were evaluated and risk factors assessed. pTBN12 was used to evaluate a large cluster in the Birmingham-Jefferson County (BJC) area. RESULTS: Statewide, a common two-band pattern was found, named JH2 (99/566, 17.5%). The most important risk associated with this pattern was homelessness (odds ratio, 8.9; P < 0.001). In the BJC area, the homeless accounted for 29% (51/175) of new cases diagnosed during the study period. For the BJC homeless, there were 13 unique RFLP patterns, and JH2 was predominant (29/33, 88%) among three clusters. Secondary analysis of the homeless JH2 cluster revealed a large group that included 19 of 24 (79%) isolates analyzed. Compared with the BJC non homeless (n = 124), the homeless were younger (P < 0.001), of male gender (P < 0.001), black race (P = 0.002), and were heavy alcohol (P < 0.001) and non-injection drug (P = 0.001) users. CONCLUSIONS: By screening tuberculosis cases statewide, a common two-band RFLP pattern was identified. Its predominance is explained by an ongoing tuberculosis epidemic among Birmingham's homeless population, highlighting RFLP as a tool for population surveillance. The pattern differences observed by pTBN12 typing clearly demonstrate that the isolates might be related but are not clonal.

Low serum antimycobacterial drug levels in non-HIV-infected tuberculosis patients.

BACKGROUND: Despite the use of directly observed therapy (DOT) by tuberculosis control programs, patient treatment failure, relapse, and acquired drug resistance remain problematic in a small number. We investigated serum drug levels in non-HIV-infected tuberculosis patients who were receiving DOT by the health department and did not respond to treatment as expected. METHODS: The indications for checking levels were as follows: (1) slow clinical response or failure to convert the sputum culture within 12 weeks; (2) treatment failure, early disease relapse < 13 months since being declared cured; (3) relapse, late disease reactivation > or = 13 months since being declared cured; and (4) acquired drug resistance while receiving DOT. Baseline characteristics of control subjects who responded to therapy as expected were compared. Venous blood for analysis was obtained at 2 h after directly observed ingestion and measured by high-performance liquid chromatography. RESULTS: Twenty-four patients receiving daily or twice-weekly standard therapy with isoniazid (INH, 300 or 900 mg) and rifampin (RMP, 600 mg) were identified; 22 had drug levels evaluated at 2 h. For INH, 15 of 22 patients (68%) had levels less than the reported target range. For RMP, 14 of 22 patients (64%) had low levels. Among the 14 patients receiving INH, 900 mg, and RMP, 600 mg, 4 (29%) had very low levels of both. Use of a combination INH/RMP tablet was associated with lower INH levels (p=0.04); however, RMP levels were higher (p<0.02). Alcohol use was associated with significantly higher RMP (p<0.01) serum concentrations. CONCLUSIONS: Important questions remain concerning the utility and timing of serum drug measurements. However, if a patient is not responding to therapy as expected and one is assured that the Mycobacterium tuberculosis organism is susceptible to the drugs given and that the patient is taking the medication as prescribed, drug level monitoring should be considered.

Early bactericidal activity of isoniazid in pulmonary tuberculosis. Optimization of methodology. The DATRI 008 Study Group.

Early bactericidal activity (EBA) of antituberculosis drugs is the rate of decrease in the concentration of tubercle bacilli sputum during the initial days of therapy. The study reported here was designed to optimize the methodology for obtaining precise EBA measurements. The study compared the results with two versus five treatment days; overnight sputum collections with early morning collections; and quantitative smears for acid-fast bacilli (AFB) with quantitative cultures. Isoniazid (INH) was used as a model drug. Among 28 smear-positive patients enrolled in the study in five cities in the United States, 16 were evaluable (INH-susceptible tuberculosis [TB] and adequate sputum collections). The mean baseline bacterial load was 6.69 log10 cfu/ml (SE = 0.24). Quantitative culture of 10- or 12-h sputum collections obtained on two baseline days and treatment Day 5 was the optimal method for EBA measurement. The mean 5-d EBA was 0.21 log10 cfu/ml/d (SE = 0.03; p < 0.001) and the EBA appeared to be constant during the first five treatment days. On the basis of these data, multiarm studies of investigational drugs will require 25 evaluable subjects per arm to detect (80% power and two-tailed alpha of 0.05) an EBA at least 50% as large as the EBA of INH. In countries with a low incidence of TB, the usefulness of this methodology for rapidly assessing new antituberculosis agents may be limited by the relatively large number of subjects required to compare EBA values across treatment arms.

Transmission of Mycobacterium tuberculosis to recipients of single lung transplants from the same donor.

Recipients of organ transplants are at increased risk for infection both because of immunosuppression and because of the transfer of microbes through the donor organs. We report two cases of M. tuberculosis disease in recipients of single lung transplants who shared a common donor. Both recipients developed pulmonary tuberculosis, one having fever and pulmonary infiltrates and the other having subclinical disease with M. tuberculosis organisms being recovered from bronchoalveolar lavage. Restriction fragment length polymorphism analysis on both isolates of M. tuberculosis revealed a common source. The donor of both lungs had a normal chest radiograph and no known prior history of M. tuberculosis infection of disease. These cases are the first report of two single lung recipients developing pulmonary tuberculosis from a common donor.

Laboratory contamination of Mycobacterium tuberculosis cultures.

The purpose of this study was to investigate possible laboratory contamination of Mycobacterium tuberculosis cultures which resulted in the misdiagnosis of tuberculosis. We have investigated three cases in which a patient's culture was positive for M. tuberculosis but there was not a high clinical suspicion for disease. In each instance, another patient with clinically obvious pulmonary tuberculosis had specimens cultured concurrently within the same clinical laboratory. The isolates from both the obvious cases of tuberculosis and the suspect cases were obtained through the State of Alabama TB Laboratory, but these isolates originated at a commercial laboratory, a community hospital laboratory, and at a university hospital. MTB isolates were fingerprinted by probing for the insertion sequence IS6110. With each of the three pairs of isolates (case and suspicious case), identical IS6110 banding patterns were found suggesting identical MTB strains. Because the patients were geographically separated, it is strongly suspected that laboratory contamination of M. tuberculosis cultures resulted in the three suspect cases being diagnosed with tuberculosis. These findings indicate that positive M. tuberculosis cultures resulting from laboratory contamination can occur.

Childhood tuberculosis in Alabama: epidemiology of disease and indicators of program effectiveness, 1983 to 1993.

An 11-year review of childhood tuberculosis in Alabama was made in order to define indicators of program effectiveness in interrupting community transmission. Minority (nonwhite) children, 96% of whom were black, had the highest risk of disease (odds ratio, 5.5; 95% confidence interval, 3.9, 7.7). Of 171 cases, 71% (n = 122) occurred in blacks and 2% (n = 3) occurred in Asian-Pacific islanders. Age 0 to 4 years (107 of 171) compared with age 5 to 14 years (64 of 171) was an additional risk factor for the development of tuberculosis (odds ratio, 3.4; 95% confidence interval 2.5, 4.7)), whereas gender was not. Males accounted for 49% of cases (83 of 171). During the period 1983 to 1993 there was no trend of increasing or decreasing numbers among child cases (trend test P = 0.94) despite significant changes by year. The purified protein derivative test had a 9% (8 of 89) false negative rate and was significantly more likely to be negative in children younger than 1 year (4 of 12 vs. 4 of 77; P = 0.01). During the 2-year interval 1992 to 1993, 19% of cases were thought to be preventable. We believe that the PPD skin test is useful and an improved contact investigation is essential to preventing childhood tuberculosis. Miniepidemics of transmission of tuberculosis from adults to a large group of children partially explain the observed disease pattern.

Drug-resistant tuberculosis in adults: implications for the health care worker.

In recent years, several outbreaks of drug-resistant tuberculosis have occurred in U.S. hospitals. In response to this recognized risk of tuberculosis exposure in health care facilities, the Centers for Disease Control and the Occupational Safety and Health Administration have issued guidelines or policy procedures for minimizing risks of tuberculosis transmission within these facilities. Some of the recommendations outlined in these governmental documents have been controversial. In this review the guidelines/policies and the debate surrounding them are discussed as they affect the health care worker who cares for adult patients with tuberculosis.

The intracellular nature of Salmonella infection during the early stages of mouse typhoid.

In mouse enteric fever (typhoid) infection with S. typhimurium, the bacteria appear to grow intracellularly, and at least during the early phase of infection they are in splenic PMNs rather than macrophages. Inflammation caused by salmonella infection and other infections, such as MHV, results in inflammatory responses that enhance resistance to salmonella infection. At least in the case of MHV, this effect is most pronounced on the rate of salmonella growth. Since the effects of the Ity locus on salmonella growth rate are readily seen during the first few days of infection, when salmonella are primarily within PMNs, the Ity locus is able to mediate its effect on salmonella pathogenesis in PMNs in vivo. Whether or not macrophages play a predominant role in salmonella pathogenesis later in infection is not yet known.

Immunology of tuberculosis.

TB is a chronic, necrotizing infection caused by M. tuberculosis. The clinical manifestations of disease are the result of a balance between the host response and bacterial virulence. Cellular immunity is responsible for effective control of infection, but cytokines released during the process of cellular immunity may also cause harm to the host. Humoral immunity plays little part in protection against TB. Individuals with defective cellular immunity are much more susceptible to disease from M. tuberculosis and are more likely to have a disseminated form of TB.

The use of monozygotic and dizygotic twins to estimate the effects of inheritance on the levels of immunoglobulin isotypes and antibodies to phosphocholine.

In the elderly there is a pronounced increase in susceptibility to infectious disease. Evidence for particular immune deficits that result in susceptibility to specific agents is lacking, however, and there is little information on the degree to which differences in the susceptibility among the elderly are due to genetic versus environmental effects. A strong association has been observed between eventual fatal pneumonia and elevated levels of IgM antibody to phosphocholine (PC) levels at age 70. In this study we evaluated the heritability of IgM and IgG antibody levels to phosphocholine in the elderly using monozygotic and dizygotic male twins. We observed genetic regulation of serum levels of IgM antibody to PC, a finding which suggests that susceptibility of the elderly to fatal pneumonia may be heritable. Levels of total IgM were under separate genetic control and there was no genetic effect on IgG and IgA levels or levels of IgG antibody to phosphocholine.

A 'safe-site' for Salmonella typhimurium is within splenic polymorphonuclear cells.

Following oral or systemic infection with Salmonella typhimurium, the focus of infection is in the liver and spleen. The majority of Salmonella surviving in the liver and spleen by 4 h post infection are already in an environment where they are largely protected from subsequent killing. Previous studies have shown that the majority of surviving Salmonella are intracellular. In the present study we sought to determine the cell type containing most of the cell-associated Salmonella liberated from the spleen. We enriched for Salmonella-containing cells by Ficoll-Hypaque separation followed by fluorescence-activated cell sorting. Approximately 85% of the total intracellular Salmonella were found in Mac-1+/J-11d+ cell fractions of the Ficoll-Hypaque band and pellet. By microscopic examination of stained cells from the sorted cell populations, it was evident that virtually all of the Salmonella were in polymorphonuclear cells (PMN). The numbers of Salmonella observed microscopically were similar in numbers to Salmonella colony forming units detected by plating. Salmonella containing PMN in the Ficoll band generally contained a single bacterium, while those from the probably less healthy cells in the Ficoll pellet generally contained several Salmonella.