Transmission of tuberculosis in Havana, Cuba: a molecular epidemiological study by IS6110 restriction fragment length polymorphism typing

The combination of molecular and conventional epidemiological methods has improved the knowledge about the transmission of tuberculosis in urban populations. To examine transmission of tuberculosis in Havana, Cuba, with DNA fingerprinting, we studied 51 out of 92 Mycobacterium tuberculosis strains isolated from tuberculosis patients who resided in Havana and whose infection was culture-confirmed in the period from September 1997 to March 1998. Isolates from 28 patients (55%) had unique IS6110 restriction fragment length polymorphism (RFLP) patterns, while isolates from 23 others (45%) had identical patterns and belonged to 7 clusters. Three clusters consisting of six, five and two cases were each related to small outbreaks that occurred in a closed setting. Three other clustered cases were linked to a large outbreak that occurred in another institution. Younger patients were more correlated to clustering than older ones. The finding that 45% of the isolates had clustered RFLP patterns suggests that recent transmission is a key factor in the tuberculosis cases in Havana. The IS6110 RFLP typing made it possible to define the occurrence of outbreaks in two closed institutions.

Use of antibiotics in pediatric intensive care and potential savings.

OBJECTIVE: Minimizing unwarranted prescription of antibiotics remains an important objective. Because of the heterogeneity between units regarding patient mix and other characteristics, site-specific targets for reduction must be identified. Here we present a model to address the issue by means of an observational cohort study. SETTING: A tertiary, multidisciplinary, neonatal, and pediatric intensive care unit of a university teaching hospital. PATIENTS: All newborns and children present in the unit (n = 456) between September 1998 and March 1999. Reasons for admission included postoperative care after cardiac surgery, major neonatal or pediatric surgery, severe trauma, and medical conditions requiring critical care. METHODS: Daily recording of antibiotics given and of indications for initiation. After discontinuation, each treatment episode was assessed as to the presence or absence of infection. RESULTS: Of the 456 patients 258 (56.6%) received systemic antibiotics, amounting to 1815 exposure days (54.6%) during 3322 hospitalization days. Of these, 512 (28%) were prescribed as prophylaxis and 1303 for suspected infection. Treatment for suspected ventilator-associated pneumonia accounted for 616 (47%) of 1303 treatment days and suspected sepsis for 255 days (20%). Patients were classified as having no infection or viral infection during 552 (40%) treatment days. The average weekly exposure rate in the unit varied considerably during the 29-week study period (range: 40-77/100 hospitalization days). Patient characteristics did not explain this variation. CONCLUSION: In this unit the largest reduction in antibiotic treatment would result from measures assisting suspected ventilator-associated pneumonia to be ruled out and from curtailing extended prophylaxis.

An examination of male and female odds ratios by BMI, cigarette smoking, and alcohol consumption for cancers of the oral cavity, pharynx, and larynx in pooled data from 15 case-control studies.

BACKGROUND: Greater tobacco smoking and alcohol consumption and lower body mass index (BMI) increase odds ratios (OR) for oral cavity, oropharyngeal, hypopharyngeal, and laryngeal cancers; however, there are no comprehensive sex-specific comparisons of ORs for these factors. METHODS: We analyzed 2,441 oral cavity (925 women and 1,516 men), 2,297 oropharynx (564 women and 1,733 men), 508 hypopharynx (96 women and 412 men), and 1,740 larynx (237 women and 1,503 men) cases from the INHANCE consortium of 15 head and neck cancer case-control studies. Controls numbered from 7,604 to 13,829 subjects, depending on analysis. Analyses fitted linear-exponential excess ORs models. RESULTS: ORs were increased in underweight (<18.5 BMI) relative to normal weight (18.5-24.9) and reduced in overweight and obese categories (>/=25 BMI) for all sites and were homogeneous by sex. ORs by smoking and drinking in women compared with men were significantly greater for oropharyngeal cancer (p < 0.01 for both factors), suggestive for hypopharyngeal cancer (p = 0.05 and p = 0.06, respectively), but homogeneous for oral cavity (p = 0.56 and p = 0.64) and laryngeal (p = 0.18 and p = 0.72) cancers. CONCLUSIONS: The extent that OR modifications of smoking and drinking by sex for oropharyngeal and, possibly, hypopharyngeal cancers represent true associations, or derive from unmeasured confounders or unobserved sex-related disease subtypes (e.g., human papillomavirus-positive oropharyngeal cancer) remains to be clarified.

Identification of Biomphalaria havanensis and Biomphalaria obstructa populations from Cuba using polymerase chain reaction and restriction fragment length polymorphism of the ribosomal RNA intergenic spacer

In Cuba, several Biomphalaria species have been reported such as B. orbignyi, B. schrammi, B. helophila, B. havanensis and B. peregrina; only the latter three are considered as potential hosts of Schistosoma mansoni. The specific identification of Biomphalaria species is based on anatomical and morphological characters of genital organs and shells. The correct identification of these snails is complicated by the high variation in these characters, similarity among species and in some cases by the small size of the snails. In this paper, we reported the classical morphological identification, the use of PCR and RFLP analysis of the internal transcribed spacer region of the ribosomal RNA genes for molecular identification of seven snail populations from different localities in Cuba. Using morphological and molecular analysis, we showed that among the studied Cuban Biomphalaria populations only B. havanensis and B. obstructa species were found.

Detection of coronary stenoses with contrast enhanced, three-dimensional free breathing coronary MR angiography using the gadolinium-based intravascular contrast agent gadocoletic acid (B-22956).

PURPOSE: To determine the diagnostic value of the intravascular contrast agent gadocoletic acid (B-22956) in three-dimensional, free breathing coronary magnetic resonance angiography (MRA) for stenosis detection in patients with suspected or known coronary artery disease. METHODS: Eighteen patients underwent three-dimensional, free breathing coronary MRA of the left and right coronary system before and after intravenous application of a single dose of gadocoletic acid (B-22956) using three different dose regimens (group A 0.050 mmol/kg; group B 0.075 mmol/kg; group C 0.100 mmol/kg). Precontrast scanning followed a coronary MRA standard non-contrast T2 preparation/turbo-gradient echo sequence (T2Prep); for postcontrast scanning an inversion-recovery gradient echo sequence was used (real-time navigator correction for both scans). In pre- and postcontrast scans quantitative analysis of coronary MRA data was performed to determine the number of visible side branches, vessel length and vessel sharpness of each of the three coronary arteries (LAD, LCX, RCA). The number of assessable coronary artery segments was determined to calculate sensitivity and specificity for detection of stenosis > or = 50% on a segment-to-segment basis (16-segment-model) in pre- and postcontrast scans with x-ray coronary angiography as the standard of reference. RESULTS: Dose group B (0.075 mmol/kg) was preferable with regard to improvement of MR angiographic parameters: in postcontrast scans all MR angiographic parameters increased significantly except for the number of visible side branches of the left circumflex artery. In addition, assessability of coronary artery segments significantly improved postcontrast in this dose group (67 versus 88%, p < 0.01). Diagnostic performance (sensitivity, specificity, accuracy) was 83, 77 and 78% for precontrast and 86, 95 and 94% for postcontrast scans. CONCLUSIONS: The use of gadocoletic acid (B-22956) results in an improvement of MR angiographic parameters, asssessability of coronary segments and detection of coronary stenoses > or = 50%.

Vertebrate conserved non coding DNA regions have a high persistence length and a short persistence time.

BACKGROUND: The comparison of complete genomes has revealed surprisingly large numbers of conserved non-protein-coding (CNC) DNA regions. However, the biological function of CNC remains elusive. CNC differ in two aspects from conserved protein-coding regions. They are not conserved across phylum boundaries, and they do not contain readily detectable sub-domains. Here we characterize the persistence length and time of CNC and conserved protein-coding regions in the vertebrate and insect lineages. RESULTS: The persistence length is the length of a genome region over which a certain level of sequence identity is consistently maintained. The persistence time is the evolutionary period during which a conserved region evolves under the same selective constraints.Our main findings are: (i) Insect genomes contain 1.60 times less conserved information than vertebrates; (ii) Vertebrate CNC have a higher persistence length than conserved coding regions or insect CNC; (iii) CNC have shorter persistence times as compared to conserved coding regions in both lineages. CONCLUSION: Higher persistence length of vertebrate CNC indicates that the conserved information in vertebrates and insects is organized in functional elements of different lengths. These findings might be related to the higher morphological complexity of vertebrates and give clues about the structure of active CNC elements.Shorter persistence time might explain the previously puzzling observations of highly conserved CNC within each phylum, and of a lack of conservation between phyla. It suggests that CNC divergence might be a key factor in vertebrate evolution. Further evolutionary studies will help to relate individual CNC to specific developmental processes.

Mycobacterium bovis: polymerase chain reaction identification in bovine Lymphonode biopsies and genotyping in isolates from Southeast Brazil by spolygotyping and restriction fragment length polymorphism

Diagnosis of the Mycobacterium tuberculosis complex by direct PCR of mediastinal lymphnode DNA and microbiological tests were compared in cattle suspicious of bearing tuberculous-like lesions detected during slaughter. The PCR procedure applied on DNA samples (n=54) obtained by adding alpha -casein into the thiocyanate extraction mix was positive in 70% of the samples. PCR confirmed the identification of 23 samples (100%) that grew in culture, 9 samples (60%) that failed to grow in culture, plus 6 (37.5%) samples that resulted in growth of bacterial contaminants. Genotyping by IS6110-RFLP and DR-spoligotyping analysis of seven samples revealed the presence of several polimorphisms. Seven of the isolates contained multiple copies of IS6110, thus defining the existence of five singular genotypes.

Female asylum seekers with musculoskeletal pain: the importance of diagnosis and treatment of hypovitaminosis D.

BACKGROUND: Hypovitaminosis D is well known in different populations, but may be under diagnosed in certain populations. We aim to determine the first diagnosis considered, the duration and resolution of symptoms, and the predictors of response to treatment in female asylum seekers suffering from hypovitaminosis D. METHODS: Design: A pre- and post-intervention observational study. Setting: A network comprising an academic primary care centre and nurse practitioners. Participants: Consecutive records of 33 female asylum seekers with complaints compatible with osteomalacia and with hypovitaminosis D (serum 25-(OH) vitamin D < 21 nmol/l). Treatment intervention: The patients received either two doses of 300,000 IU intramuscular cholecalciferol as well as 800 IU of cholecalciferol with 1000 mg of calcium orally, or the oral treatment only. Main outcome measures: We recorded the first diagnosis made by the physicians before the correct diagnosis of hypovitaminosis D, the duration of symptoms before diagnosis, the responders and non-responders to treatment, the duration of symptoms after treatment, and the number of medical visits and analgesic drugs prescribed 6 months before and 6 months after diagnosis. Tests: Two-sample t-tests, chi-squared tests, and logistic regression analyses were performed. Analyses were performed using SPSS 10.0. RESULTS: Prior to the discovery of hypovitaminosis D, diagnoses related to somatisation were evoked in 30 patients (90.9%). The mean duration of symptoms before diagnosis was 2.53 years (SD 3.20). Twenty-two patients (66.7%) responded completely to treatment; the remaining patients were considered to be non-responders. After treatment was initiated, the responders' symptoms disappeared completely after 2.84 months. The mean number of emergency medical visits fell from 0.88 (SD 1.08) six months before diagnosis to 0.39 (SD 0.83) after (P = 0.027). The mean number of analgesic drugs that were prescribed also decreased from 1.67 (SD 1.5) to 0.85 (SD 1) (P = 0.001). CONCLUSION: Hypovitaminosis D in female asylum seekers may remain undiagnosed, with a prolonged duration of chronic symptoms. The potential pitfall is a diagnosis of somatisation. Treatment leads to a rapid resolution of symptoms, a reduction in the use of medical services, and the prescription of analgesic drugs in this vulnerable population.

Morphological aspects of Schistosoma mansoni adult worms isolated from nourished and undernourished mice: a comparative analysis by confocal laser scanning microscopy

Malnutrition hampers the course of schistosomiasis mansoni infection just as normal growth of adult worms. A comparative morphometric study on adult specimens (male and female) recovered from undernourished (fed with a low protein diet - regional basic diet) and nourished (rodent commercial laboratory food, NUVILAB) white mice was performed. Tomographic images and morphometric analysis of the oral and ventral suckers, reproductive system and tegument were obtained by means of confocal laser scanning microscopy. Undernourished male specimens presented smaller morphometric values (length and width) of the reproductive system (first, third and last testicular lobes) and thickness of the tegument than controls. Besides that, it was demonstrated that the dorsal surface of the male worms bears large tubercles unevenly distributed, but kept grouped and flat. At the subtegumental region, vacuolated areas were detected. It was concluded that the inadequate nutritional status of the vertebrate host has a negative influence mainly in the reproductive system and topographical somatic development of male adult Schistosoma mansoni, inducing some alterations on the structure of the parasite.

Genetic and environmental components of phenotypic variation in immune response and body size of a colonial bird, Delichon urbica (the house martin).

Directional selection for parasite resistance is often intense in highly social host species. Using a partial cross-fostering experiment we studied environmental and genetic variation in immune response and morphology in a highly colonial bird species, the house martin (Delichon urbica). We manipulated intensity of infestation of house martin nests by the haematophagous parasitic house martin bug Oeciacus hirundinis either by spraying nests with a weak pesticide or by inoculating them with 50 bugs. Parasitism significantly affected tarsus length, T cell response, immunoglobulin and leucocyte concentrations. We found evidence of strong environmental effects on nestling body mass, body condition, wing length and tarsus length, and evidence of significant additive genetic variance for wing length and haematocrit. We found significant environmental variance, but no significant additive genetic variance in immune response parameters such as T cell response to the antigenic phytohemagglutinin, immunoglobulins, and relative and absolute numbers of leucocytes. Environmental variances were generally greater than additive genetic variances, and the low heritabilities of phenotypic traits were mainly a consequence of large environmental variances and small additive genetic variances. Hence, highly social bird species such as the house martin, which are subject to intense selection by parasites, have a limited scope for immediate microevolutionary response to selection because of low heritabilities, but also a limited scope for long-term response to selection because evolvability as indicated by small additive genetic coefficients of variation is weak.

Redescription of the Male of Lutzomyia lutziana (Costa Lima) and Description of the Female (Diptera: Psychodidae)

During the course of taxonomic studies of New World phlebotomine sand flies, it was discovered that the female specimen considered to be the female of Lutzomyia lutziana does not belong to this species. A new description of the female of L. lutziana is presented, based on specimens captured in Lassance, State of Minas Gerais, the type locality of the species. The male of L. lutziana is also redescribed, based on an exemplar caught in Curvelo, State of Minas Gerais.

Identification of Human T-lymphotropic Virus Type I (HTLV-I) Subtypes Using Restrited Fragment Length Polymorphism in a Cohort of Asymptomatic Carriers and Patients with HTLV-I-associated Myelopathy/tropical Spastic Paraparesis from São Paulo, Brazil

Although human T-lymphotropic virus type I (HTLV-I) exhibits high genetic stability, as compared to other RNA viruses and particularly to human immunodeficiency virus (HIV), genotypic subtypes of this human retrovirus have been characterized in isolates from diverse geographical areas. These are currently believed not to be associated with different pathogenetic outcomes of infection. The present study aimed at characterizing genotypic subtypes of viral isolates from 70 HTLV-I-infected individuals from São Paulo, Brazil, including 42 asymptomatic carriers and 28 patients with HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), using restricted fragment length polymorphism (RFLP) analysis of long terminal repeat (LTR) HTLV-I proviral DNA sequences. Peripheral blood mononuclear cell lysates were amplified by nested polymerase chain reaction (PCR) and amplicons submitted to enzymatic digestion using a panel of endonucleases. Among HTLV-I asymptomatic carriers, viral cosmopolitan subtypes A, B, C and E were identified in 73.8%, 7.1%, 7.1% and 12% of tested samples, respectively, whereas among HAM/TSP patients, cosmopolitan A (89.3%), cosmopolitan C (7.1%) and cosmopolitan E (3.6%) subtypes were detected. HTLV-I subtypes were not statistically significant associated with patients' clinical status. We also conclude that RFLP analysis is a suitable tool for descriptive studies on the molecular epidemiology of HTLV-I infections in our environment.