Antibiotic-mediated bacteriome depletion in ApcMin/+ mice is associated with reduction in mucus-producing goblet cells and increased colorectal cancer progression.

Recent epidemiological evidence suggests that exposure to antibiotics in early-to-middle adulthood is associated with an increased risk of colorectal adenoma. However, mechanistic studies in established preclinical cancer to examine these claims are extremely limited. Therefore, we investigated the effect of long-term exposure of an antibiotic cocktail composed of Vancomycin, Neomycin, and Streptomycin, on tumor development and progression in the ApcMin/+ mouse, an established genetic model for familial adenomatous polyposis. Clinical pathologies related to tumor development as well as intestinal and colon tissue histopathology were studied at ages 8, 12, and 16 weeks of age, which correspond to the approximate ages of development of neoplasia, gut inflammation with polyposis, and cancer progression, respectively, in this animal model. We show that the antibiotics significantly increase the severity of clinical symptoms, including effects on intestinal histology and goblet cell numbers. In addition, they promote small intestinal polyposis. Finally, metagenomic analysis of fecal samples demonstrated that antibiotic exposure is associated with a significant but nonuniform depletion of the animal's natural gut flora. Overall, these findings support the premise that long-term antibiotic exposure mediates the selected depletion of gut microbial communities and the concomitant thinning of the protective mucus layer, resulting in an increase in tumor development.

The importance of audiometric monitoring in patients with multidrug-resistant tuberculosis

Abstract INTRODUCTION: A total of 771 cases of multidrug-resistant tuberculosis (MDR-TB) were reported in Brazil in 2014. Treatment of MDR-TB with aminoglycosides can produce serious side effects such as permanent and irreversible hearing loss, which occurs in 5-64% of cases, and severely compromise patient quality of life. The goal of this research was to evaluate auditory and vestibular side effects in patients treated for MDR-TB and to identify associations between these complaints and the type of aminoglycoside used. METHODS: We performed a retrospective review of 599 medical records from patients with MDR-TB who were treated at the Hélio Fraga/Fiocruz Reference Center between 2006 and 2010. Cases without auditory or vestibular complaints and patients who were not treated with aminoglycoside drugs were excluded from the study. RESULTS: Of 164 eligible cases, 55 (33.5%) reported an auditory or vestibular complaint and medication was subsequently suspended, although hearing damage was not confirmed in all cases. Audiometric testing confirmed hearing loss in 11 (21.7%) of 12 cases submitted for evaluation. Hearing loss related to ototoxicity was confirmed in 15 (62.5%) cases. Tinnitus was significantly associated with the use of amikacin and streptomycin. CONCLUSIONS: Evaluations of ototoxicity symptoms were not usually reported in the routine care of patients with MDR-TB. Complaints of tinnitus were associated with amikacin and streptomycin use. These results require confirmation in future studies.

TRP channels in brown and white adipogenesis from human progenitors: new therapeutic targets and the caveats associated with the common antibiotic, streptomycin.

Transient receptor potential (TRP) channels are polymodal cell sensors responding to diverse stimuli and widely implicated in the developmental programs of numerous tissues. The evidence for an involvement of TRP family members in adipogenesis, however, is scant. We present the first comprehensive expression profile of all known 27 human TRP genes in mesenchymal progenitors cells during white or brown adipogenesis. Using positive trilineage differentiation as an exclusion criterion, TRP polycystic (P)3, and TPR melastatin (M)8 were found to be uniquely adipospecific. Knockdown of TRPP3 repressed the expression of the brown fat signature genes uncoupling protein (UCP)-1 and peroxisome proliferator-activated receptor γ coactivator (PGC)-1α as well as attenuated forskolin-stimulated uncoupled respiration. However, indices of generalized adipogenesis, such as lipid droplet morphology and fatty acid binding protein (FAPB)-4 expression, were not affected, indicating a principal mitochondrial role of TRPP3. Conversely, activating TRPM8 with menthol up-regulated UCP-1 expression and augmented uncoupled respiration predominantly in white adipocytes (browning), whereas streptomycin antagonized TRPM8-mediated calcium entry, downregulated UCP-1 expression, and mitigated uncoupled respiration; menthol was less capable of augmenting uncoupled respiration (thermogenesis) in brown adipocytes. TRPP3 and TRPM8 hence appear to be involved in the priming of mitochondria to perform uncoupled respiration downstream of adenylate cyclase. Our results also underscore the developmental caveats of using antibiotics in adipogenic studies.-Goralczyk, A., van Vijven, M., Koch, M., Badowski, C., Yassin, M. S., Toh, S.-A., Shabbir, A., Franco-Obregón, A., Raghunath, M. TRP channels in brown and white adipogenesis from human progenitors: new therapeutic targets and the caveats associated with the common antibiotic, streptomycin.

Attenuation of streptomycin ototoxicity by tetramethylpyrazine in guinea pig cochlea.

OBJECTIVE: Tetramethylpyrazine has been suggested to have a therapeutic effect on impaired hearing that is induced by aminoglycoside antibiotics. However, its effectiveness on streptomycin ototoxicity and its cellular mechanisms are relatively unknown. Here we investigate the protective effect of tetramethylpyrazine on streptomycin-induced ototoxicity in guinea pig cochlea. STUDY DESIGN: Prospective randomized laboratory study. SETTING: Hearing Research Laboratory of China Medical University. SUBJECTS AND METHODS: Adult guinea pigs were randomized to 4 groups. Hearing sensitivity of guinea pigs was tested by auditory brainstem response measurements before streptomycin exposure and again 10 days later. The cochlear tissues were prepared for electron microscopy and immunohistochemical staining of heat shock protein 70 (HSP70). The effect of tetramethylpyrazine on streptomycin-induced activation of caspase-3 was evaluated by Western blotting. RESULTS: Co-therapy with tetramethylpyrazine reduced a profound streptomycin-induced auditory threshold shift compared with streptomycin treatment alone (P = .0002 or P = .00008). Tetramethylpyrazine also attenuated the structural disruption in streptomycin-treated outer hair cells and marginal cells of vascular stria by transmission electronic microscopy and scanning electronic microscopy, respectively. Moreover, tetramethylpyrazine decreased the streptomycin-stimulated expressions of HSP70 and caspase-3. The correlation analysis demonstrated that HSP70 expression had a positive correlation with auditory brainstem response thresholds (|R| = 0.6-0.9, P = .0073 or P = .0169). CONCLUSIONS: Our data suggest that the protective effect of tetramethylpyrazine on hearing function is associated with the reduction of stress response and inhibition of apoptosis. Tetramethylpyrazine may have therapeutic potential for patients with ototoxicity diseases.

Intestinal alkaline phosphatase prevents antibiotic-induced susceptibility to enteric pathogens.

OBJECTIVE: To determine the efficacy of oral supplementation of the gut enzyme intestinal alkaline phosphatase (IAP) in preventing antibiotic-associated infections from Salmonella enterica serovar Typhimurium (S. Typhimurium) and Clostridium difficile. BACKGROUND: The intestinal microbiota plays a pivotal role in human health and well-being. Antibiotics inherently cause dysbiosis, an imbalance in the number and composition of intestinal commensal bacteria, which leads to susceptibility to opportunistic bacterial infections. Previously, we have shown that IAP preserves the normal homeostasis of intestinal microbiota and that oral supplementation with calf IAP (cIAP) rapidly restores the normal gut flora. We hypothesized that oral IAP supplementation would protect against antibiotic-associated bacterial infections. METHODS: C57BL/6 mice were treated with antibiotic(s) ± cIAP in the drinking water, followed by oral gavage of S. Typhimurium or C. difficile. Mice were observed for clinical conditions and mortality. After a defined period of time, mice were killed and investigated for hematological, inflammatory, and histological changes. RESULTS: We observed that oral supplementation with cIAP during antibiotic treatment protects mice from infections with S. Typhimurium as well as with C. difficile. Animals given IAP maintained their weight, had reduced clinical severity and gut inflammation, and showed improved survival. CONCLUSIONS: Oral IAP supplementation protected mice from antibiotic-associated bacterial infections. We postulate that oral IAP supplementation could represent a novel therapy to protect against antibiotic-associated diarrhea (AAD), C. difficile-associated disease (CDAD), and other enteric infections in humans.

Tratamiento directamente observado de la tuberculosis en un hospital de la Ciudad de Buenos Aires / Directly observed treatment for tuberculosis in a Buenos Aires City hospital

Se describe la experiencia en la aplicación del tratamiento directamente observado de tuberculosis (TDO) en el período 1/1/1979-31/12/2009 y la comparación de los resultados obtenidos en el periodo 1979-1999 versus los de 2000- 2009. En un hospital de la Ciudad de Buenos Aires, 582 pacientes HIV negativos recibieron inicialmente rifampicina, isoniazida, pirazinamida y etambutol o estreptomicina. En la segunda fase 424 de estos pacientes tratados entre 01/01/1979 y 31/12/1999 (G1), recibieron esquemas bisemanales con rifampicina/isoniazida o isoniazida/estreptomicina y otros 158 pacientes, tratados entre 01/01/2000 y 31/12/2009 (G2) recibieron un esquema bisemanal o trisemanal con rifampicina/isoniazida. Se siguieron las recomendaciones de los programas de control de la Nación y la Ciudad. Los pacientes bajo TDO tuvieron tasas de tratamiento completo más elevadas (82.8% versus 48.7%), (p < 0.0001) con respecto a otros 483, que siguieron tratamiento autoadministrado (AUTO); la edad promedio fue de 36.3 ± 15.3 años, 63.1% eran varones y 69.4% tenían nacionalidad argentina. Presentaron tratamiento previo el 8.9%, comorbilidades el 6.1% y el 70.6% de las formas pulmonares fueron confirmadas bacteriológicamente. El 9.5% presentó efectos adversos a drogas y el sexo masculino presentó mayor frecuencia de abandonos (p = 0.004). Con respecto al G1, en el G2 hubo menor proporción de pacientes argentinos (48.7% vs. 77.1%), (p ≤ 0.0001), mayor frecuencia de comorbilidades (10.7% vs. 4.4%), (p = 0.005), de formas clínicas pulmonares con confirmación bacteriológica (95% vs. 87%), (p = 0.02) y de efectos adversos a drogas (17% vs. 6.6%), (p ≤ 0.0001). Hallamos tasas de cumplimiento total elevadas en TDO (82.8%), similares a las otras publicaciones.

The outcomes of directly observed therapy of tuberculosis (DOT) between 1/1/1979 and 12/31/2009 were analyzed. Results obtained in the 1979-1999 period were compared with those achieved in the 2000-2009 period. In a Buenos Aires City hospital, 582 HIV negative TB patients received rifampin, isoniazid, pyrazinamide and ethambutol or streptomycin in the initial stage, followed by a second stage where patients were included in two groups: G1 composed by 424 patients (period 1/1/1979-12/31/1999) who received either rifampin and isoniazid or rifampin and streptomicin twice a week, and G2, with 158 patients (period 1/1/2000-12/31/2009) who received either rifampin and isoniazid twice or three times a week. National and Buenos Aires City TB Control Programs recommendations were followed. Patients who underwent DOT had higher completeness rates than those included in self-administered therapy (82.8% vs. 48.7%), (p <0.0001). Mean age: 36.3±15.3 years, males: 63.1% and 69.4% were Argentine citizens. A 8.9% had been previously treated, 6.1% had co-morbidities. A 70.6% of pulmonary cases was bacteriologically confirmed, 82.8% of them completed the treatment, while 11.5% defaulted. Adverse effects to antituberculosis drugs were observed in 9.5% of cases; male patients showed higher rates of non adherence. G2 had a lower proportion of native people (48.7% vs. 77.1%), (p ≤ 0.0001), higher frequency of co-morbidities (10.7% vs. 4.4%), (p = 0.005), of bacteriologically confirmed pulmonary cases (95% vs. 87%), (p = 0.02) and more adverse effects than G1 (17% vs. 6.6%), (p ≤ 0.0001). In coincidence with other experiences, this work shows high treatment success rates in patients treated under DOT strategy.

Preditores dos desfechos do tratamento da tuberculose / Predictors of tuberculosis treatment outcomes

OBJETIVO: Analisar os desfechos do tratamento da tuberculose e seus preditores. MÉTODOS: Estudo longitudinal de coorte de pacientes com tuberculose tratados entre 2004 e 2006 no Instituto de Pesquisa Evandro Chagas, na cidade do Rio de Janeiro. As razões de risco ajustadas (RRa) dos preditores foram estimadas. RESULTADOS: Foram incluídos 311 pacientes. As taxas de cura, de abandono, de mortalidade e de falha terapêutica foram, respectivamente, 72 por cento, 19 por cento, 6 por cento e 2 por cento. A troca de regime terapêutico por eventos adversos foi necessária em 8 por cento. O alcoolismo (RRa, 0,30), uso do regime estreptomicina+etambutol+ofloxacina (SEO; RRa, 0,32), infecção por HIV sem tratamento antirretroviral (TARV; RRa, 0,36) e o uso do regime rifampicina+isoniazida+pirazinamida+etambutol (RRa, 0,58) reduziram a probabilidade de cura. A faixa etária mais jovem (RRa, 3,84) e o alcoolismo (RRa, 1,76) aumentaram a probabilidade do abandono. Não foi possível determinar as RRa para os demais desfechos devido a suas baixas prevalências. Entretanto, medidas do risco relativo (RR) identificaram os seguintes potenciais preditores do óbito: uso de esquema SEO (RR, 11,43), infecção pelo HIV sem TARV (RR, 9,64), forma clínica disseminada (RR, 9,09), ausência de confirmação bacteriológica (RR, 4,00), diabetes mellitus (RR, 3,94) e comportamento homo/bissexual (RR, 2,97). A baixa renda (RR, 11,70) foi potencial preditor para falha terapêutica, ao passo que infecção pelo HIV com uso de TARV (RR, 2,46) e forma clínica disseminada (RR, 3,57) foram potenciais preditores para troca do esquema por evento adverso. CONCLUSÕES: O esquema SEO deve ser utilizado transitoriamente quando possível. Os dados confirmam a importância de TARV e sugerem a necessidade de seu início precoce.

OBJECTIVE: To analyze tuberculosis treatment outcomes and their predictors. METHODS: This was a retrospective longitudinal cohort study involving tuberculosis patients treated between 2004 and 2006 at the Instituto de Pesquisa Evandro Chagas, in the city of Rio de Janeiro. We estimated adjusted risk ratios (ARRs) for the predictors of treatment outcomes. RESULTS: Among 311 patients evaluated, the rates of cure, treatment abandonment, treatment failure, and mortality were 72 percent, 19 percent, 2 percent, and 6 percent, respectively. Changes in the treatment regimen due to adverse events occurred in 8 percent. The factors found to reduce the probability of cure were alcoholism (ARR, 0.30), use of the streptomycin+ethambutol+ofloxacin (SEO) regimen (ARR, 0.32), HIV infection without the use of antiretroviral therapy (ART; ARR, 0.36), and use of the rifampin+isoniazid+pyrazinamide+ethambutol regimen (ARR, 0.58). Being younger and being alcoholic both increased the probability of abandonment (ARR, 3.84 and 1.76, respectively). It was impossible to determine the ARR for the remaining outcomes due to their low prevalence. However, using the relative risk (RR), we identified the following potential predictors of mortality: use of the SEO regimen (RR, 11.43); HIV infection without ART (RR, 9.64); disseminated tuberculosis (RR, 9.09); lack of bacteriological confirmation (RR, 4.00); diabetes mellitus (RR, 3.94); and homosexual/bisexual behavior (RR, 2.97). Low income was a potential predictor of treatment failure (RR, 11.70), whereas disseminated tuberculosis and HIV infection with ART were potential predictors of changes in the regimen due to adverse events (RR, 3.57 and 2.46, respectively). CONCLUSIONS: The SEO regimen should not be used for extended periods. The data confirm the importance of ART and suggest the need to use it early.

mtDNA mutations, hearing loss and aminoglycoside treatment in Mexicans / Mutações em DNA mitocondrial, hipoacusia e tratamento de mexicanos com aminoglicosídeos

Streptomycin and aminoglycoside derivatives are commonly used to treat tuberculosis and other stubborn infections; these drugs may alter auditory and/or vestibular function. Mutations in mitochondrial DNA have been associated with hypersensitivity to aminoglycosides; no studies have been conducted in Mexicans, which are very prone to such alterations because aminoglycosides have been prescribed carelessly for many years, irrespective of the ailment to be treated. AIM: We investigated "hot spot" mutations described previously as causing inner ear alterations. METHODS: Hot spot mutations at the 12S rRNA gene and the tRNA Serine (UCN) gene were screened by PCR-RFLP and sequencing in 65 subjects undergoing audiological and vestibular testing. STUDY DESIGN: Experimental. RESULTS: 32 individuals had healthy auditory and vestibular function, whereas 33 subjects had auditory affections. We found none of the previously reported mutations related to aminoglycoside hypersensitivity, or non-syndromic hearing loss. Two hearing-impaired patients that had been treated with streptomycin had the T1189C variant of the mitochondrial 12S rRNA region. CONCLUSION: Mutations related to hearing loss in other ethnic backgrounds were not found in Mexicans. However, the T1189C variant is possibly a putative mutation related to aminoglycoside hypersensitivity and was present in 2 patients.

Derivados de aminoglicosídeos e estreptomicina são comumente utilizados para tratar tuberculose e outras infecções mais resistentes; esses medicamentos podem alterar a função vestibular e/ou auditiva. Mutações no DNA mitocondrial têm sido associadas à hipersensibilidade a aminoglicosídeos; não há estudos conduzidos com mexicanos, que são muito predispostos a tais alterações, uma vez que aminoglicosídeos têm sido exageradamente prescritos há anos, sem associações à doença sendo tratada. OBJETIVO: investigamos mutações "hot spot" previamente descritas como causas de alterações no ouvido interno. MÉTODOS: Mutações hot spot no gene 12S rRNA e gene SerinatRNA (UCN) foram triados pela PCR-RFLP e sequenciados em 65 indivíduos sujeitos a exames audiométricos e vestibulares. Desenho do estudo: Experimental. RESULTADOS: 32 indivíduos com funções auditiva e vestibular normais, e 33 indivíduos com doenças auditivas. Não encontramos nenhuma das mutações previamente relatadas como associadas à hipersensibilidade aos aminoglicosídeos, ou perda auditiva não-sindrômica. Dois pacientes com hipoacusia que haviam sido tratados com estreptomicina tinham a variante T1189C na região 12S rRNA. CONCLUSÃO: Mutações associadas à hipoacusia em outras etnias não foram encontradas em mexicanos. Entretanto, a variante T1189C é possivelmente uma mutação associada à hipersensibilidade a aminoglicosídeos, e esteve presente em dois pacientes.

Desfechos do retratamento de pacientes com tuberculose com o uso do esquema 3 em Porto Alegre, Brasil / Retreatment of tuberculosis patients in the city of Porto Alegre, Brazil: outcomes

OBJETIVO: Descrever os desfechos do retratamento de pacientes com tuberculose com o uso do esquema 3 (estreptomicina, etambutol, etionamida e pirazinamida por 3 meses + etambutol e etionamida por 9 meses) devido à falência do tratamento com o esquema básico (rifampicina, isoniazida e pirazinamida por 2 meses + rifampicina e isoniazida por 4 meses). MÉTODOS: Estudo descritivo de coorte histórica, não controlada, com adultos que foram tratados com o esquema 3. Foram avaliados os desfechos desse tratamento, as reações adversas aos fármacos, as recidivas e os fatores associados. RESULTADOS: Foram incluídos no estudo 229 pacientes. A taxa de cura geral foi de 62 por cento. Entre os pacientes que usaram a medicação regularmente e aqueles que a usaram irregularmente, a taxa de cura foi de 88 por cento e 31 por cento, respectivamente. Observaram-se reações adversas em 95 pacientes (41,5 por cento), principalmente digestivas. Ocorreram 17 recidivas (12,0 por cento) nos cinco anos de seguimento. CONCLUSIONS: Os desfechos com o uso do esquema 3, em geral, não foram satisfatórios, pois esse esquema foi aplicado em uma população selecionada com alto risco de não adesão ao tratamento e apresenta altas taxas de reações adversas, especialmente as de tipo digestivo, possivelmente causadas pela etionamida. No entanto, para aqueles que conseguiram tomar a medicação regularmente, a taxa de cura foi satisfatória. A taxa de recidiva foi superior àquela preconizada por consensos internacionais, possivelmente devido ao tempo de tratamento curto (apenas 12 meses). Acreditamos que o esquema 3 estendido para 18 meses poderia ser uma alternativa para pacientes com comprovada adesão ao tratamento.

OBJECTIVE: To describe the outcomes of retreatment in tuberculosis patients receiving the regimen known, in Brazil, as regimen 3 (streptomycin, ethambutol, ethionamide, and pyrazinamide for 3 months + ethambutol and ethionamide for 9 months) after treatment failure with the basic regimen (rifampin, isoniazid, and pyrazinamide for 2 months + rifampin and isoniazid for 4 months). METHODS: A descriptive, uncontrolled, historical cohort study involving adult tuberculosis patients treated with regimen 3. We evaluated adverse drug effects, recurrence, treatment outcomes, and associated factors. RESULTS: The study included 229 patients. The overall cure rate was 62 percent. For the patients who used the medications regularly and those who did not, the cure rate was 88 percent and 31 percent, respectively. Adverse events occurred in 95 patients (41.5 percent), and most of those events were related to the gastrointestinal tract. In the five-year follow-up period, relapse occurred in 17 cases (12.0 percent). CONCLUSIONS: Overall, the outcomes of treatment with regimen 3 were unsatisfactory, in part because this regimen was administered to a selected population of patients at high risk for noncompliance with treatment, as well as because it presents high rates of adverse effects, especially those related to the gastrointestinal tract, which might be caused by ethionamide. However, for those who took the medications regularly, the cure rate was satisfactory. The recurrence rate was higher than that recommended in international consensus guidelines, which might be attributable to the short (12-month) treatment period. We believe that regimen 3, extended to 18 months, represents an option for patients with proven treatment compliance.

[Streptomycin-induced apoptosis of rat cochlear hair cell cultured in vitro].

OBJECTIVE: To evaluate if caspase pathway was involved in streptomycin-induced cell apoptosis in cochlear hair cells. METHODS: F344 rats at postnatal day 3 or 4 were used for the study in cochlear organotypic cultures. The cochlear basilar membrane was micro-dissected out and cultured overnight, and then treated with 1 mmol/L streptomycin for 24 hours. Before the termination, the activity of caspase-8, 9 or 6 were detected with FAM-peptide-FMK labeled caspase-8, 9 or 6, respectively. The stereocilia and cuticular plate of hair cells were stained with TRITC conjugated phalloidin, and the nuclei were stained with Topro-3 DNA probe. The specimens were observed and photographed under confocal fluorescent microscope. RESULTS: Streptomycin with 1 mmol/L causes about 80% cochlear hair cells missing in the basal turn and 10% hair cell loss in the apex. After streptomycin treatment, the nuclear shrinkage and fragmentation were found in most cochlear hair cells, and the caspase-8, caspase-9 and caspase-6 were greatly activated. CONCLUSIONS: Apoptosis is involved in the cochlear hair cells death induced by Streptomycin in vitro. The caspase activities in upstream and downstream are maybe the major apoptotic pathway.

[Ototoxic effects of streptomycin in vestibular organotypic cultures].

OBJECTIVE: To investigate the ototoxic effects of streptomycin in vestibular organotypic cultures. METHODS: F344 rats with age at postnatal day three or four were used for this study. The maculae of saccule and utricle were routinely dissected out and cultured with serum-free medium containing various dose of streptomycin for 24 hours. The ciliary turf of vestibular hair cells was stained with fluorescent phalloidin, and its nucleus was stained with to pro-3 DNA probe. The vestibular hair cells were quantitatively counted and photographed under confocal fluorescent microscope. RESULTS: Morphological feature of vestibular hair cells were good in normal control cultures. However, the density of hair cells was decreased in evidence with increase of streptomycin sulfate concentrations. Twenty-four hours after streptomycin cultures, 0.25 mmol/L streptomycin caused a 10% hair cell missing, 50% hair cell loss from 1 mmol/L streptomycin treatment, and more than 75% hair cells gone post-3 mmol/L streptomycin cultures. After streptomycin treatment, the nuclear shrinkage and fragmentation were found in vestibular hair cells, whereas the vestibular supporting cells were normal. CONCLUSION: Streptomycin induced-vestibular hair cells lesion was in a dose dependent manner with nuclear shrinkage and fragmentation. This may suggest that streptomycin leads vestibular hair cell die through apoptosis.

Hearing impairment in patients with tuberculosis from Northeast Brazil

Este trabalho teve por objetivo descrever o perfil auditivo de pessoas que realizaram tratamento para tuberculose com estreptomicina em Recife nos anos de 2000 e 2001. Para tal foi utilizado o banco de dados do Sistema de Informação de Agravos de Notificação, fornecido pela Secretária de Saúde deste município, sendo selecionadas 78 pessoas que usaram a droga no período em estudo. Do total de pacientes selecionados sete eram menores de 18 anos ou maiores de 58 anos, 19 haviam falecido, 13 não foram localizados, dois eram presidiários, um negou-se a participar, restando, pois 36 indivíduos que puderam ser submetidos a uma entrevista, a meatoscopia e a audiometria. No grupo estudado predominou o sexo masculino (79,4%) e a média das idades era de 38,8 anos. Dos 36 pacientes, 27 (75,0%) apresentaram alteração auditiva, sendo a mais freqüente a sensório-neural bilateral (63,9%), com predomínio de freqüências agudas, a partir de 4000 Hz. Os achados com elevados percentuais de alteração auditiva entre os usuários de estreptomicina, apontam para a necessidade de aprofundamento deste tema em outros estudos, e também sugerem a necessidade de estruturação de um sistema de monitoramento auditivo para a população de pacientes submetidos a esse quimioterápico no tratamento para tuberculose.

A rare case of streptomycin-induced toxic epidermal necrolysis in a patient with tuberculosis: a therapeutic dilemma.

OBJECTIVE: To report a case of streptomycin-induced toxic epidermal necrolysis (TEN). CASE SUMMARY: A 55-year-old woman was admitted for treatment of active pulmonary tuberculosis (TB). She was given standard oral anti-TB chemotherapy including isoniazid, rifampin, pyrazinamide, and streptomycin. On the fourth day of therapy, she experienced high fever at 39 degrees C, chills, vomiting, pruritus, and diffuse erythema, followed by extensive bullae formation and skin denudation. Diagnosis of TEN was considered, and all anti-TB drugs were discontinued. Skin biopsy disclosed complete epidermal necrosis with dermal-epidermal cleavage and absence of inflammatory infiltrate, highly suggestive of TEN. The patient was transferred to the intensive care unit. Her general condition and skin lesions improved. A staged-fashion exposure test to the 4 anti-TB drugs allowed the incrimination of streptomycin as the offending agent. DISCUSSION: Anti-TB drugs, mainly rifampin, ethambutol, and isoniazid, have been incriminated in TEN. Streptomycin-induced TEN remains an extremely rare event. However, minor allergic skin reactions (rash, urticaria) have been described with this drug. Our patient presents a rare case of streptomycin-related TEN. Even though dangerous, a step-wise exposure test was necessary to allow safe treatment of active pulmonary TB. It also provided a strong argument of a cause-effect relationship between TEN and streptomycin. An objective causality assessment using the Naranjo rating scale revealed that the adverse drug event was highly probable. CONCLUSIONS: Streptomycin should be added to the list of drugs that induce TEN.

Adverse drug reactions observed during DOTS.

A total of 8.37% of the 1195 patients treated at NDTB Centre with DOTS under RNTCP between January 2002 to June 2003 presented with adverse drug reactions. Patients showing any sort of adverse reactions were studied in detail by personal interviews and a semi-structured questionnaire. The profile of patients presenting with adverse reactions showed that majority of the patients (53%) had gastrointestinal reactions, the commonest presenting complaint being nausea and vomiting. General aches and pains were complained by about 35% and giddiness was the presenting complaint in 27% irrespective of the use of streptomycin, although giddiness was observed more often in Category II patients (59%). Skin rash and itching was complained by about 17% of patients and 11% complained of arthralgia, while only 1% had hepatotoxicity during treatment. Majority of the adverse reactions (67%) were observed within the first four weeks of treatment and only 0.25% of patients treated with DOTS had interruption of treatment for short periods.

Chemical and physical labyrinthectomy for Meniere's disease.

The use of intratympanic gentamicin is currently a popular and easily performed office procedure for the conservative treatment of the Meniere's disease patient who has failed medical therapy or who is not a candidate for surgical therapy. The procedure provides excellent control for the symptom of vertigo. Despite this success, there remains a significant risk of hearing loss irrespective of administered dose. In the future, antioxidant [42,43] or salicylate therapy may prevent aminoglycoside toxicity [44]. These prophylaxis methods have shown promise in the laboratory. Current methods do not allow for accurate drug delivery to the inner ear. Middle ear mucosal status, round window thickness or adhesion, patency of eustachian tube, and the effect of endolymphatic hydrops on ototoxicity are factors simply out of the control of the operator's hands. Judging by the number of recent articles, intratympanic gentamicin instillation will continue to be an area of interest for the otologist. Users should be encouraged to be consistent and conservative in gentamicin dosing. It is clear that vestibular ablation is not necessary for adequate control of vestibular symptoms and that larger doses may increase the risk of hearing loss. American Academy of Otolaryngology-Head and Neck Surgery guidelines [45] should be used and adhered to for reporting on the treatment of Meniere's disease, so that the literature may be more comparable. In the same light, a prospective standardized trial would be helpful in determining ultimate efficacy and risk to the patient. Transmastoid labyrinthectomy remains the surgical standard for extirpating the offending labyrinth when hearing preservation is not an issue. In appropriate patients, the procedure is a safe and effective method for relieving patients of vertiginous attacks. Most patients tolerate the procedure very well and are able to compensate fairly well over the course of several weeks to months.

Atypical muscle pathology and a survey of cis-mutations in deaf patients harboring a 1555 A-to-G point mutation in the mitochondrial ribosomal RNA gene.

We investigated three families with maternally inherited deafness associated with a 1555 A-to-G substitution in the 12S ribosomal RNA gene. Probands in these families developed deafness following streptomycin treatment, whereas several family members who did not receive aminoglycoside showed onset of deafness in middle age. One proband had a non-synonymous A14062G mutation in the ND5 gene and the other had a non-synonymous G15221A mutation in the cytochrome b gene and a T1391C mutation in the 12S ribosomal RNA gene, whose importance in disease expression remains to be clarified. Two muscle biopsies from the patients with and without streptomycin treatment, showed similar findings; a moth-eaten appearance with decreased cytochrome c oxidase activity and abnormal mitochondrial morphology. These findings suggest that even without exposure to aminoglycoside the A1555G mutation may impair mitochondrial function and that the mitochondrial abnormalities associated with the A1555G mutation may be expressed in tissues other than those of the auditory system.

Recovery from vestibular ototoxicity.

OBJECTIVE: Determine whether subjects with documented vestibular ototoxicity recover vestibular function and, if so, investigate the recovery dynamics. STUDY DESIGN: Prospective and retrospective reviews and repeated measures. SETTING: Clinical research and technology center. SUBJECTS: Twenty-eight subjects who received vestibulotoxic medications were followed for at least 12 months after initial treatment. CONTROLS: Our subject sample was compared with a published database of normal individuals. INTERVENTIONS: All 28 subjects received systemically administered medications known to be ototoxic. The subjects' treating physicians controlled medication, dosage, and administration schedules. MAIN OUTCOME MEASURES: Tests of horizontal canal vestibulo-ocular function were performed. Subjects' auditory and vestibular symptoms were recorded. RESULTS: Eleven subjects (39%) showed changes in horizontal canal vestibulo-ocular gain constant (GC) and/or time constant (TC) consistent with vestibular ototoxicity. When tested 1 year after ototoxic drug administration, eight of the nine subjects who experienced ototoxic decrease in GC showed a recovery of GC to normal limits. Only one of the eight subjects who experienced ototoxic decrease in TC showed recovery of TC to within normal limits. Ototoxicity onset and recovery were independent of baseline vestibular function, and ototoxicity onset did not correlate with cumulative dose of ototoxic medication. There was no relationship between subjective symptoms and ototoxicity onset. CONCLUSIONS: Recovery of GC after vestibular ototoxicity is more commonly observed than recovery of TC. Because ototoxic changes developed and continued in an unpredictable time and manner in relation to ototoxic drug administration, we propose that once ototoxic changes in vestibulo-ocular reflex are detected, ototoxic medications should be discontinued as soon as possible.