Sonography of neck lymph nodes. Part II: abnormal lymph nodes

Assessment of cervical lymph nodes is essential for patients with head and neck carcinomas, and ultrasound is a useful imaging technique. Sonographic features that help distinguish between the causes of neck lymphadenopathy, including grey scale and Doppler features, are discussed. In addition to the distribution and location of nodes, the useful grey-scale features are: size, shape, internal architecture, intranodal necrosis, absence of hilar structure and calcification. The useful Doppler features are: distribution of vascularity and intranodal resistance. Ancillary features such as oedema of soft tissue and nodal matting are particularly helpful to identify tuberculous nodes.     

Isolated solitary vertebral body tuberculosis--study of seven cases

AIM: To describe the magnetic resonance imaging (MRI) findings in isolated solitary vertebral body tuberculosis. Also to emphasize tuberculosis as an important entity, besides neoplasms, in the differential diagnosis of pathologies involving a single vertebral body. MATERIAL AND METHODS: The clinical and imaging features of seven patients (four men and three women; age range 18-60 years), with proved solitary vertebral body tuberculosis were retrospectively studied. RESULTS: Isolated solitary vertebral body tuberculosis is seen in only 1.69% of the total proven cases of spine tuberculosis seen in our institute between 1993 and 2002. All patients presented with constitutional symptoms and localized pain and tenderness. MRI showed decreased signal intensity on T1-weighted images and increased signal intensity on T2-weighted images. Cortical break was seen in three patients of whom epidural and pre-vertebral extensions were seen in one each. CONCLUSIONS: Although tuberculosis affecting a solitary vertebral body is rare it should be considered as an important differential diagnosis, besides neoplasms. In these cases MRI serves as the best imaging technique available for diagnosis. However, confirmation can only be made on histopathology or culture of the specimen.     

Activity against multidrug-resistant Mycobacterium tuberculosis in Mexican plants used to treat respiratory diseases

The increase of multidrug-resistant Mycobacterium tuberculosis (MDR-TB) demands the search for alternative antimycobacterial drugs. The aim of this study was to evaluate plants used in Mexican traditional medicine to treat respiratory diseases for activity against MDR-TB. A group of 22 plants was screened for activity against Mycobacterium tuberculosis H37Rv and Mycobacterium avium at concentrations from 50 to 200 microg/mL. The antimycobacterial effect was determined by a microcolorimetric assay with Alamar blue dye. None of the aqueous extracts had antimycobacterial activity. Hexane extracts from Artemisia ludoviciana, Chamaedora tepejilote, Lantana hispida, Juniperus communis and Malva parviflora, and methanol extracts from Artemisia ludoviciana and Juniperus communis inhibited the growth of Mycobacterium tuberculosis. Mycobacterium avium was inhibited by Juniperus communis hexane extract and by Malva parviflora methanol extract. The active extracts were tested against monoresistant variants of Mycobacterium tuberculosis H37Rv (isoniazid, rifampin, streptomycin and ethambutol resistant) and the hexane extract of Lantana hispida showed the best activity. Lantana hispida hexane extract was also active against a group of MDR-TB clinical isolates. In contrast, it did not inhibit the growth of non-tuberculous mycobacteria. The hexane extract of Lantana hispida was fractionated by column chromatography and one of its fractions (FVI) inhibited the growth of all the MDR-TB clinical isolates at concentrations up to 25 microg/mL. This study supports the fact that selecting plants by ethnobotanical criteria enhances the probability of finding species with activity against mycobacteria, and our results point to Lantana hispida as an important source of potential compounds against MDR-TB.     

Multidrug-resistant tuberculosis in HIV-negative patients,Buenos Aires,Argentina

Initial multidrug-resistant (MDR) tuberculosis (TB) in HIV-negative patients treated at a Buenos Aires referral hospital from 1991 to 2000 was examined by using molecular clustering of available isolates. Of 291 HIV-negative MDRTB patients, 79 were initially MDR. We observed an ascending trend of initial MDRTB during this decade (p=0.0033). The M strain, which was responsible for an institutional AIDS-associated outbreak that peaked in 1995 to 1997, caused 24 of the 49 initial MDRTB cases available for restriction fragment length polymorphism. Of those, 21 were diagnosed in 1997 or later. Hospital exposure increased the risk of acquiring M strain-associated MDRTB by approximately two and a half times. The emergence of initial MDRTB among HIV-negative patients after 1997 was apparently a sequel of the AIDS-related outbreak. Because the prevalence of M strain-associated disease in the study population did not level out by the end of the decade, further expansion of this disease is possible.     

Primary Gastric Tuberculosis Mimicking Gastric Tumor That Results in Pyloric Stenosis

Summary BACKGROUND: Primary gastric tuberculosis is rarely seen. It usually produces a diagnostic challenge and may mimic peptic ulcer disease and even a neoplasia. We present a case of primary gastric tuberculosis initially thought to be a neoplasia. METHODS: A 46-year-old female was admitted with one-month history of nausea, vomiting and weight loss. A barium swallow showed a constant filling defect in the antral and prepyloric region. On upper endoscopy, an 8 cm mass was noted in antral and prepyloric regions. The biopsy specimens taken during endoscopy were insufficient for precise diagnosis. An operative diagnosis of gastric carcinoma leading to pyloric stenosis without any distant metastasis was made; a subtotal distal gastrectomy and roux-en-Y gastroenterostomy procedure was therefore applied. RESULTS: Pathologic evaluation revealed necrotic granulomatous inflammation throughout the wall of corpus, necrotizing granulomatous lymphadenitis in the lesser and greater curvature lymph nodes, and also in omentum. There were no findings of carcinoma. Ehrlich-Ziehl-Nielsen staining method revealed numerous acid-fast bacilli. Despite extensive studies, no evidence of extragastric tuberculous involvement was discovered, and she was prescribed an antituberculosis therapy for a period of one year. The patient remains asymptomatic. CONCLUSIONS: Primary gastric tuberculosis usually produces a diagnostic challenge and may mimic peptic ulcer disease and even a neoplasia.     

宝安区暂住人口涂阳肺结核病的管治研究

目的 研究暂住人口肺结核病的管治。方法 采用世界银行贷款中国结核病控制项目的管治方法,对暂住人口涂阳肺结核病人采用DOTS管理和免费治疗,以同期常住人口涂阳肺结核病人为对照组。结果 1993～2000年,暂住人口肺结核涂阳病人是常住人口涂阳肺结核病人的2.8倍。暂住人口涂阳肺结核病人治愈率为94.8％,常住人口为95.7％,两者间差别无显著性意义(P<0.05)。结论 开放城市的暂住人口迅速增加,暂住人口肺结核病是开放城市结核病防治的主要工作。对暂住和常住人口涂阳肺结核病人实行DOTS管治的效果是一样的。     

由小鼠肺组织病理学改变评价结核DNA疫苗的保护效力

目的 评价结核分支杆菌MPT64和ESAT6 DNA疫苗的保护效力。方法 将BALB/c小鼠随机分为5组,分别用生理盐水(A）、载体质粒（B）、卡介苗（C）、MPT64 DNA疫苗（D）和ESAT6 DNA疫苗（E）免疫小鼠。最后一次免疫3周后以结核分支杆菌H37Rv腹腔内攻击小鼠。攻击5或10周后,观察肺组织病理改变。结果 结核分支杆菌攻击5周后,A和B组小鼠肺组织病变表现为以渗出性反应为主的混合性组织反应;C组表现为以上皮样细胞肉芽肿和肺泡壁结核肉芽组织中度增生为主的增殖性组织反应;D组3只和E组1只小鼠与A、B组表现相似,D组2只和E组4只小鼠与C组表现相似。结核分支杆菌攻击10周后,A、B和D组肺病变主要表现为由许多泡沫样巨噬细胞、淋巴细胞和少量上皮样细胞组成的结核性肉芽肿及肺泡壁结核性肉芽组织中度增生、增厚;C和E组均表现为上皮样细胞和淋巴细胞组成的结核性肉芽肿及肺泡壁结核性肉芽组织中到重度增生、增厚。各组小鼠均未见干酪样坏死。结论 结核分支杆菌MPT64和ESAT6 DNA疫苗能增强机体免疫力,ESAT6 DNA疫苗的保护效力比MPT64 DNA疫苗强,但均未超过卡介苗。     

Knowledge and practices regarding tuberculosis: a survey of final-year medical students from Canada, India and Uganda

CONTEXT: Tuberculosis is one of the most common infectious diseases worldwide and is responsible for the largest number of deaths from a single infectious cause. OBJECTIVE: The objective of this study was to compare the knowledge of and practices regarding tuberculosis in final-year medical students at schools from endemic and non-endemic areas. SUBJECTS: Final-year medical students at McMaster University in Canada, the Christian Medical College in India, and Makerere University in Uganda. METHODS: A questionnaire consisting of 20 multiple-choice questions assessing knowledge, practices, and exposure. A total knowledge score (maximum=13) and a total practice score (maximum=5) were created for each study site. RESULTS: 160 questionnaires were returned; the response rate was 68.4% (65/95) for McMaster University, 39.7% (23/58) for the Christian Medical College and 78.3% (72/92) for Makerere University. Students from Makerere University had the highest knowledge scores but differences were non-significant after adjustment for patient exposure and curriculum time (F(2,153)= 1.80, P=0.16). Differences in practice scores, however, remained significant after adjusting for curriculum time and patient exposure (F(2,153)=5.14, P=0.006). Knowledge score (F(1,156)=5.05, P=0.02), patient exposure (F(1,153)=9.11, P=0.003), and curriculum time and patient exposure (F(2,153)=5.14, P=0.006) were statistically significant positive predictors of the total practice score. CONCLUSIONS: This study demonstrated significant differences in undergraduate exposure to tuberculosis, total knowledge, and practice competency at three medical schools in Canada, India, and Uganda. In general, the knowledge base and practice competency of all three graduating classes was adequate.     

Can serial qualitative polymerase chain reaction monitoring predict outcome of pulmonary tuberculosis treatment?

BACKGROUND: The aim of this study was to assess the use of qualitative one-tube nested polymerase chain reaction (PCR) for monitoring the treatment response in smear-positive pulmonary tuberculosis, and the factors determining the negative conversion of sputum smear, culture, and PCR during treatment. METHODOLOGY: A total of 53 patients receiving a standard short course of chemotherapy with 24 months follow-up period after treatment cessation were included in the study. Sputum specimens were collected serially for smear, culture, and PCR until the treatment was complete. RESULTS: The conversion rate for sputum culture, smear, and PCR at 8 weeks after treatment were 84.9, 58.5, and 47.1%, and at 16 weeks of treatment were 100, 88.7, and 79.2%, respectively. At the end of the treatment period, there were four PCR persisters, one of whom had disease relapse. Only cavitary disease had an influence over the negative conversion of the smear and PCR at 8 weeks (RR 3.5, 95% CI 1.04-11.95, P=0.04 for smear; RR 5.06, 95% CI 1.196-21.42, P=0.03 for PCR). CONCLUSION: Qualitative PCR was not useful for monitoring therapy in smear-positive pulmonary tuberculosis. Mycobacterium DNA was cleared slowly in cavitary disease. The PCR may be performed at the time of treatment cessation to identify those with potential for disease relapse.