Serum samples obtained from human immunodeficiency virus (HIV)-infected tuberculosis (TB) patients

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Approximately 5 to 10% of individuals who get infected with Mycobacterium tuberculosis progress to clinical tuberculosis (TB), whereas the remaining individuals develop a latent infection with the organism. Another 5 to 10% of these latently infected individuals reactivate their infection and progress to clinical TB during subsequent years/decades. In either case, active infection with M. tuberculosis is identified only when progression to bacteriologically detectable disease occurs. Thus, clinical TB, whether noncavitary paucibacillary or cavitary multibacillary disease, represents the late stages of a chronic disease process.Our studies of humoral immune responses elicited by M. tuberculosis at different stages of infection and disease progression have shown that the profile of antigenic proteins expressed by the in vivo bacteria that elicit antibodies correlates with the stage of the infection (21-23, 35-37, 45). Thus, purified-protein derivative-positive (PPD ϩ ) healthy individuals have antibodies to only a small subset (4-6) of the Ͼ100 culture filtrate proteins (CFP) of M. tuberculosis. In contrast, patients with noncavitary paucibacillary TB have antibodies directed against ϳ10 to 12 additional CFP antigens (35). As the disease progresses to the development of cavitary lesions, besides the presence of antibodies to the above-mentioned antigens, antibodies to an additional ϳ10 to 12 antigens appear. These results provide evidence that as M. tuberculosis adapts to different in vivo environments, the profile of antigenic proteins that are expressed changes. Evidence for adaptation by M. tuberculosis to different environmental conditions by altering gene/protein expression has also come from several other labs (3,11,12,29,32,41,42,47,49).M. tuberculosis is a slowly growing organism, and it takes weeks to months for the infection to progress to primary clinical TB. The time that elapses between the initiation of reactivation of latent infection and the manifestation of clinical TB is not known. The goal of the current studies was to identify antigenic proteins that are expressed during the asymptomatic, subclinical stages of infection when the in vivo M. tuberculosis bacilli replicate actively but the infection has not progressed to clinically identifiable disease (incipient, subclinical TB). Insight into these antigenic proteins will aid understanding of the host-pathogen interactions that lead to the progression of infection to clinical disease, and modulation of these host-pathogen interactions could potentially alter the outcome of infection. Moreover, antigenic proteins expressed during subclinical stages of active infection would also be useful for devising diagnostic markers that can differentiate between truly latent TB that is unlikely to progress to clinical disease and incipient, subclinical TB.

Laparoscopic cholecystectomy is the gold standard in gallbladder surgery all over the world today. The operation is routinely performed using four or three ports of entry into the abdomen. We have now modified this procedure and introduced a new innovative two-port method of gallbladder removal. Between September 1997 and November 1997, 50 consecutive patients (41 females and 9 males; mean age 41 years) with calculus cholecystitis underwent our new two-port procedure. In this operation, only the supraumbilical port (10 mm/5 mm) and the epigastric port (10 mm) were used for access. The gallbladder was manipulated through three strategically placed traction sutures, passed through the fundus, the body, and the neck area of the gallbladder, respectively. The operating time required was 35 to 125 minutes, with an average time of 56 minutes. None of the patients required conversion to the four-port technique. All patients were on liquids after 6 hours. The average hospital stay was 1.31 days. Postoperative pain was significantly reduced, and the procedure was cosmetically more acceptable to the patient.

A simplified procedure has been formulated and tested for determining average root length density (RLD) by auger sampling at a single site in wheat, corn and mustard. It involves the determination of horizontal root distribution in the representative half of the unit soil strip (distance from base of plant to mid-point in the rows) by excavating small monolith segments in the top soil layer. Average RLD is computed by dividing the integral of polynomial function fitted to the horizontal root distribution (in the unit soil strip) with its length. The average RLD, thus, obtained is interpolated on the curve between root length density and horizontal distance from the plant base (d) in the representative half of the unit soil strip. Root length density determined by centering 5 cm diameter auger at the interpolated d gave minimum deviation from the average RLD of that layer compared to the other possible single site sampling schemes with same-sized auger. These results indicate that for row crops, the best centre for single-site augering is about one-third of distance from the plant base to mid-way between the two rows.

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Efforts to devise immunoassays for tuberculosis (TB) that can be adapted to rapid formats are ongoing. The present study was aimed at determining whether urinary anti-Mycobacterium tuberculosis antibodies are present in patients with TB, to evaluate the feasibility of developing a urine antibody-based diagnostic test. Urinary antibodies directed against the culture filtrate proteins of M. tuberculosis, MPT 32, and the 81-kDa GlcB protein were detectable in patients with TB, although the sensitivity of antibody detection was lower (53%-64%), compared with serum antibodies (68%-77%). Surprisingly, with all 3 antigens, the use of paired serum and urine samples provided higher sensitivities of antibody detection than either single specimen, and anti-GlcB antibodies were present in the serum and/or urine of 39 (90%) of 43 smear-positive patients with TB. Although, with the current methods and antigens, the level of sensitivity is insufficient to design a urinary antibody diagnostic test, these studies provide the foundation for further studies on the development of a urine antibody-based immunoassay for TB.