Cost-benefit of serum pepsinogen screening for gastric adenocarcinoma in the Mexican population.

INTRODUCTION AND AIM: Helicobacter pylori (H. pylori) is known to be capable of causing chronic inflammation of the gastric mucosa that slowly progresses through the premalignant stages, reaching localized gastric adenocarcinoma (GAC). Its outcome is closely related to the stage at which diagnosis is made. The aim of the present study was to determine cost-benefit by comparing esophagogastroduodenoscopy, serum pepsinogen detection, and no screening at all. MATERIAL AND METHODS: Utilizing Markov chains and Monte Carlo simulation, the costs and effects of various detection modalities were simulated to analyze the cost-benefit of each strategy. For our population, we used the published data of patients with gastric cancer, applicable to the Mexican population. RESULTS: The results were reported as incremental cost-effectiveness ratios. The best strategy was serum pepsinogen determination, followed by the strategy of endoscopic examination with continued monitoring every 3 years. CONCLUSIONS: The performance of serum pepsinogen serology and directed endoscopic examination (and continued monitoring, if necessary) for GAC screening could be a cost-effective intervention in Mexico, despite the low-to-moderate general prevalence of the disease.

Cost-benefit of serum pepsinogen screening for gastric adenocarcinoma in the Mexican population. / Costo-beneficio de cribado de adenocarcinoma gástrico por pepsinógeno sérico en la población mexicana.

INTRODUCTION AND AIM: Helicobacter pylori (H. pylori) is known to be capable of causing chronic inflammation of the gastric mucosa that slowly progresses through the premalignant stages, reaching localized gastric adenocarcinoma (GAC). Its outcome is closely related to the stage at which diagnosis is made. The aim of the present study was to determine cost-benefit by comparing esophagogastroduodenoscopy, serum pepsinogen detection, and no screening at all. MATERIAL AND METHODS: Utilizing Markov chains and Monte Carlo simulation, the costs and effects of various detection modalities were simulated to analyze the cost-benefit of each strategy. For our population, we used the published data of patients with gastric cancer, applicable to the Mexican population. RESULTS: The results were reported as incremental cost-effectiveness ratios. The best strategy was serum pepsinogen determination, followed by the strategy of endoscopic examination with continued monitoring every 3 years. CONCLUSIONS: The performance of serum pepsinogen serology and directed endoscopic examination (and continued monitoring, if necessary) for GAC screening could be a cost-effective intervention in Mexico, despite the low-to-moderate general prevalence of the disease.

Rainbow: a toolbox for phylogenetic supertree construction and analysis.

UNLABELLED: Rainbow is a program that provides a graphic user interface to construct supertrees using different methods. It also provides tools to analyze the quality of the supertrees produced. Rainbow is available for Mac OS X, Windows and Linux. AVAILABILITY: Rainbow is a free open-source software. Its binary files, source code, and manual can be downloaded from the Rainbow web page: http://genome.cs.iastate.edu/Rainbow/

Pathologic findings and association of Mycobacterium bovis infection with the bovine NRAMP1 gene in cattle from herds with naturally occurring tuberculosis.

OBJECTIVE: To determine necropsy and Mycobacterium bovis culture results in cattle from herds with tuberculosis, the role of the bovine NRAMP1 gene in resistance and susceptibility to infection with M bovis, and the association between magnitude of the tuberculous lesions and various types of M bovis isolates. ANIMALS: 61 cattle from herds with tuberculosis in Texas and Mexico. PROCEDURE: 61 cattle were evaluated by necropsy; 59 had positive and 2 had negative caudal fold tuberculin intradermal test (CFT) results. Thirty-three cattle with positive CFT results were genotyped to evaluate polymorphism of the 3' untranslated region of the bovine NRAMP1 gene, using single-stranded conformational analysis, 9 were resistant to M bovis with no tuberculous lesions and negative M bovis culture results, and 24 were susceptible with tuberculous lesions and positive M bovis culture results. Isolates of M bovis were analyzed by restriction fragment length polymorphism (RFLP) on the basis of IS6110 sequences and direct-repeat fingerprinting patterns. RESULTS: 21 (35.6%; 21/59) cattle with positive CFT results had tuberculous lesions or positive culture results; in addition, 1 of 2 cattle with negative CFT results had tuberculous lesions and positive culture results. Tuberculous lesions were most common in the thorax (35/63; 55.5%) and lymphoid tissues of the head (10/63; 15.9%). Tuberculous lesions varied from 1 to 11/animal; 8 of 21 (38.1%) had solitary lesions. Associations were not found between resistance or susceptibility to infection with M bovis and polymorphism in the NRAMP1 gene or between the magnitude of the lesions and various RFLP types of M bovis isolates. CONCLUSIONS AND CLINICAL RELEVANCE: The NRAMP1 gene does not determine resistance and susceptibility to infection with M bovis in cattle.

Failure to identify non-bovine reservoirs of Mycobacterium bovis in a region with a history of infected dairy-cattle herds.

The State of Texas had the most (cumulative) tuberculous cattle herds of any state in the United States during the decade ending in 1997. Of the cumulative 18 infected herds in Texas, 12 herds were concentrated in El Paso County (designated the 'El Paso milkshed'). To identify whether non-bovine reservoirs were a source of Mycobacterium bovis infection of cattle in this region, an investigation was conducted on the premises of 14 dairy herds (12 tuberculous and 2 non-affected herds) between May 1995 and June 1997. None of the 670 mammalian, avian and environmental (soil, water and air) samples collected and cultured from the premises of these herds was positive for the presence of M. bovis. None of the 119 human urine samples obtained from employees of these dairies was culture positive for M. bovis. Of 124 dairy-farm workers with tuberculin skin-test results, 48 showed positive test results. There was, however, no difference in percentages of positive skin-test results between farms without, and farms having, bovine tuberculosis within the last two years or longer. The percentage of positive reactions did not increase with length of time employed at a dairy with a history of confirmed tuberculosis. These findings suggest that non-bovine reservoirs appear not to be a factor responsible for tuberculosis of cattle in the El Paso milkshed.

Molecular fingerprinting confirms extensive cow-to-cow intra-herd transmission of a single Mycobacterium bovis strain.

In this study we have characterized M. bovis isolates from a herd of cattle in Uvalde, Texas in which 52 of the 193 animals selected at random in 1994 from a herd of 331 were caudal fold skin-test positive. Thirty-two of 52 skin-test positive cattle had gross lesions at slaughter, and isolations of M. bovis were made from 29 animals. The herd was comprised of Red Devon cattle purchased between 1978 and 1980 (n = 26) and breeding bulls (n = 3) introduced at later times, and all were tuberculosis test negative at the time of purchase. Other animals were natural additions (offspring) of these cattle. One additional animal, a Holstein present on the ranch at the time of purchase in 1976, was retained to nurse orphaned and weak calves. Using several molecular fingerprinting techniques we have verified a clonal relationship among the M. bovis isolates consistent with infection originating with a single strain. The molecular fingerprint patterns demonstrate the stability of the profiles despite persistence and spread of the organism within the herd for two decades and confirms their use in epidemiological tracing.

Effect of tuberculosis on milk production in dairy cows.

OBJECTIVE: To evaluate differences in milk production between cows with positive and negative caudal fold tuberculin test results in a Mycobacterium bovis-infected dairy herd. DESIGN: Cross-sectional epidemiologic survey. ANIMALS: 369 Holstein cows with lactation duration between 200 and 360 days. PROCEDURE: The caudal fold tuberculin test was performed. Information on milk production data, parity, calving season, days of lactation, previous milk production, and whether cows had clinical mastitis was obtained from farm records. Composite milk samples were collected and submitted for bacterial culture. RESULTS: 170 cows had positive tuberculin test results, and 199 had negative results. Cows with positive test results produced less milk (mean, 347 kg [763 lb]) than did cows with negative test results after adjusting for variables biologically related to milk production. Calving season (spring, summer) was significantly associated with reduced milk production. Cows with clinical mastitis produced less milk than did cows without clinical mastitis, but the difference was not statistically significant in the multiple regression analysis. CLINICAL IMPLICATIONS: In this herd, tuberculosis was associated with a 4% decrease in milk production. Milk production losses per cow attributable to calving season (spring, summer) were 3 times those attributable to tuberculosis. However, because of the high prevalence of tuberculosis in this herd, the impact of tuberculosis on total herd milk production was an additional cause for concern.

Molecular epidemiology of Mycobacterium bovis in Texas and Mexico.

Seventy-nine Mycobacterium bovis isolates recovered from Mexican and Texas cattle were categorized into 16 and 25 distinct types on the basis of IS6110 and direct-repeat fingerprint patterns, respectively. By using a combination of both fingerprint patterns, 30 distinct restriction fragment length polymorphism types were defined. Fifty-eight of 79 isolates (73%) were distributed among nine clusters. Clustered isolates were identified within herds, as well as in geographically disperse herds in Texas and Mexico. This observation is consistent with active transmission within herds and among herds, presumably as a result of active or historical cattle movements. The majority of bovine isolates (64 of 79) exhibited a single copy of IS6110. Interestingly, in contrast to previous studies, a high percentage of bovine isolates (15 of 79) exhibited multiple IS6110 copies (two to five) distributed among 11 different restriction fragment length polymorphism types. It is speculated that transmission from noncattle sources may be responsible. Continued fingerprinting of isolates originating from nonbovine sources and herd surveys is expected to provide useful information regarding the epidemiology of tuberculosis in this region.

Fast algorithms for inferring evolutionary trees.

We present algorithms for the perfect phylogeny problem restricted to binary characters. The first algorithm is faster than a previous algorithm by Gusfield when the input matrix for the problem is sparse. Next, we present two online algorithms. For the first of these, the set of species is fixed and the characters are given as input one at a time, while, for the second, the set of characters is fixed and the species are given as input one at a time. These two online algorithms are then combined into an algorithm that can process any sequence of additions and deletions of species and characters.

Facial musculoskeletal asymmetry in hemifacial microsomia.

Computer-assisted medical imaging--transaxial computed tomography (CT) scans and three-dimensional surface reconstructions--was used to study the muscles of mastication and their osseous origins and insertions in 24 patients with untreated unilateral hemifacial microsomia (HFM). The relationship between the volume of a muscle of mastication and the shape and size of its origin and insertion in such patients varies widely. Comparison of mean volumes of specific muscles documents a statistically significant decrease among patients who have moderate to marked mandibular dysmorphology as compared with those with minimally dysmorphic mandibles. This study supports the hypothesis that the shape and size of the mandible are related to the muscles that originate and insert upon it. However, the variation among individual patients means that assumptions regarding muscle mass and, in turn, function cannot be made regarding an individual patient on the basis of osseous dysmorphology that has been demonstrated on skull radiographs alone.

[Percutaneous catheterization of the superior vena cava system, using the large veins at the base of the neck]. / Cateterizarea percutana a sistemului cav superior, folosind venele mari de la baza gîtului

Catheterization of the superior caval system by punctioning of the subclavial vein, or of the deep jugular vein, has many positive aspects. Confronting the data from the literature with their own experience the authors discuss the results obtained in a total of 1884 catheterizations of this type.