Spatial clusters of latent tuberculous infection, Connecticut, 2010-2014

SETTING

In the United States, tuberculosis (TB) control is increasingly focusing on the identification of persons with latent tuberculous infection (LTBI).

OBJECTIVE

To characterize the local epidemiology of LTBI in Connecticut, USA.

METHODS

We used spatial analyses 1) to identify census tract-level clusters of reported LTBI and TB disease in Connecticut, 2) to compare persons and populations in clusters with those not in clusters, and 3) to compare persons with LTBI to those with TB disease.

RESULTS

Significant census tract-level spatial clusters of LTBI and TB disease were identified. Compared with persons with LTBI in non-clustered census tracts, those in clustered census tracts were more likely to be foreign-born and less likely to be of white non-Hispanic ethnicity. Populations in census tract clusters of high LTBI prevalence had greater crowding, persons living in poverty, and persons lacking health care insurance than populations not in clustered census tracts. Persons with LTBI were less likely than those with TB disease to be of Asian ethnicity, and persons with LTBI were more likely than those with TB disease to reside in a clustered census tract.

CONCLUSIONS

Characterizing fine-scale populations at risk for LTBI supports effective and culturally accessible screening and treatment programs.

Growth responses and ion accumulation in the halophytic legume Prosopis strombulifera are determined by Na2SO4 and NaCl

Halophytes are potential gene sources for genetic manipulation of economically important crop species. This study addresses the physiological responses of a widespread halophyte, Prosopis strombulifera (Lam.) Benth to salinity. We hypothesised that increasing concentrations of the two major salts present in soils of central Argentina (Na2SO4, NaCl, or their iso-osmotic mixture) would produce distinct physiological responses. We used hydroponically grown P. strombulifera to test this hypothesis, analysing growth parameters, water relations, photosynthetic pigments, cations and anions. These plants showed a halophytic response to NaCl, but strong general inhibition of growth in response to iso-osmotic solutions containing Na2SO4. The explanation for the adaptive success of P. strombulifera in high NaCl conditions seems to be related to a delicate balance between Na(+) accumulation (and its use for osmotic adjustment) and efficient compartmentalisation in vacuoles, the ability of the whole plant to ensure sufficient K(+) supply by maintaining high K(+)/Na(+) discrimination, and maintenance of normal Ca(2+) levels in leaves. The three salt treatments had different effects on the accumulation of ions. Findings in bi-saline-treated plants were of particular interest, where most of the physiological parameters studied showed partial alleviation of SO4(2-)-induced toxicity by Cl(-). Thus, discussions on physiological responses to salinity could be further expanded in a way that more closely mimics natural salt environments.

Missed opportunities to prevent tuberculosis in foreign-born persons, Connecticut, 2005-2008

SETTING

Factors that influence testing for latent tuberculosis infection (LTBI) among foreign-born persons in Connecticut are not well understood.

OBJECTIVE

To identify predictors for LTBI testing and challenges related to accessing health care among the foreign-born population in Connecticut.

DESIGN

Foreign-born Connecticut residents with confirmed or suspected tuberculosis (TB) disease during June 2005-December 2008 were interviewed regarding health care access and immigration status. Predictors for self-reported testing for LTBI after US entry were determined.

RESULTS

Of 161 foreign-born persons interviewed, 48% experienced TB disease within 5 years after arrival. One third (51/156) reported having undergone post-arrival testing for LTBI. Although those with established health care providers were more likely to have reported testing (aOR 4.49, 95%CI 1.48-13.62), only 43% of such persons were tested. Undocumented persons, the majority of whom lacked a provider (53%), were less likely than documented persons to have reported testing (aOR 0.20, 95%CI 0.06-0.67). Hispanic permanent residents (immigrants and refugees) and visitors (persons admitted temporarily) were more likely than non-Hispanics in the respective groups to have reported testing (OR 5.25, 95%CI 1.51-18.31 and OR 7.08, 95%CI 1.30-38.44, respectively).

CONCLUSIONS

The self-reported rate of testing for LTBI among foreign-born persons in Connecticut with confirmed or suspected TB was low and differed significantly by ethnicity and immigration status. Strategies are needed to improve health care access for foreign-born persons and expand testing for LTBI, especially among non-Hispanic and undocumented populations.

Choledocholithiasis: a prospective study of spontaneous common bile duct stone migration

BACKGROUND

The rate of spontaneous migration of bile duct stones through the duodenal papilla is not well known. Endoscopic retrograde cholangiography (ERC) has been the standard method to diagnose bile duct stones, but accumulating data show there is a good agreement between ERC and endoscopic ultrasonography (EUS). The aim of the study was to evaluate the incidence and time course of stone migration in patients with bile duct stones by analyzing discrepancies between EUS and ERC as a function of the elapsed time between these two procedures. Stone migration was considered as the absence of stones at time of ERC regardless of the number of stones seen at EUS.

METHODS

The main criterion for inclusion was the presence of bile duct stone as shown by EUS. Ninety-two consecutive patients were prospectively included in this study.

RESULTS

Choledocholithiasis was absent at ERC in 12 patients. In univariate analysis, presence of gallbladder was significantly associated with an increased rate of stone migration (correction for multiple testing would remove this statistical significance). The size of the stone was the only independent factor to predict migration.

CONCLUSION

Migration occurred in about 21% of cases within 1 month. Our study emphasizes the need to analyze carefully the results of comparative imaging studies of bile duct stones.

Ultrastructure of hepatocyte abnormalities in perimetastatic areas

The ultrastructural pathology of non-invaded hepatocytes located in close proximity to metastases from diverse gastrointestinal carcinomas was studied. Observed abnormalities included swelling of rough and smooth endoplasmic reticulum, proliferation of lysosomes, and mitochondrial alterations as presence of granules and paracrystalline inclusions, marked pleomorphism, and lack of cristae. These results show that, contrary to the classical conception, the non-invaded cells surrounding primary tumours or their metastases could be abnormal.

Microvascular pathology in the skeletal muscle paraneoplastic phenomenon

An electron microscopic investigation was made in order to study capillary alterations in the muscle paraneoplastic phenomenon associated with different malignant tumours. Several abnormalities were found including basement membrane widening and lamination, endothelial hypertrophy, a varied degree of lumen occlusion, and proliferative changes in pericytes. A degenerative process leading to capillary necrosis was also observed. A mononuclear cell infiltrate formed by macrophages, lymphocytes and mast cells was seen. The capillary changes observed suggest the existence of an autoimmune vascular factor in the etiopathogenesis of muscle damage in this phenomenon.

[Restoration of transcription antitermination of N- bacteriophages in Escherichia coli with a mutant RNA polymerase]

The N protein of bacteriophage lambda modifies Escherichia coli RNA polymerase in such a way that it transcribes through termination signals, in a process called antitermination. In general N-mutants are not able to perform transcription antitermination. In this paper we report the suppression of N7 and Nmar3 mutations by Escherichia coli ron-lon strain. The lon mutation causes the N protein half-life to raise, suggesting that excess of N7 fragment or Nmar3 protein overcome the defect in antitermination. Under these conditions the lambda N-phages produced a titer similar to lambda wild type, although the plaques were smaller. These observations highlight the relevance of N half life in the regulation of transcription antitermination.

Developmental regulation of CUP gene expression through DNA methylation in Mucor spp

Inserts which carried the CUP gene from Saccharomyces cerevisiae or Mucor racemosus were used as hybridization probes to measure the methylation state and expression of the CUP gene from Mucor rouxii at different stages of growth. It was observed that the fungus contains a CUP multigene family. All the CUP genes were present in a hypermethylated DNA region in nongrowing and isodiametrically growing spores and were not transcribed at these stages. After germ tube emergence, CUP genes became demethylated and transcriptionally active. Development, demethylation, and transcription of CUP genes were blocked by the ornithine decarboxylase inhibitor 1,4-diaminobutanone. These results suggest that genes that are activated during development became demethylated in this fungus.

Structure of a ribosomal protein gene in Mucor racemosus

As an extension of our analysis of the translational apparatus of Mucor racemosus we have isolated a gene encoding a ribosomal protein of Mucor. Based on a method developed for S. cerevisiae, we identified by hybrid selection and in vitro translation a lambda-Charon 4A clone containing the genomic copy of a Mucor ribosomal protein. The gene consisted of two exons of 57 and 387 nucleotides. The two exons were separated by an 131 nucleotide intron. The processed transcript was 714 nucleotides in length and contained a 25 nucleotide untranscribed leader and an 114 nucleotide untranscribed 3'-end. The protein predicted from the nucleotide sequence contained 148 amino acids and exhibited 61% identity with the S19 ribosomal protein of Xenopus laevis. The promoter region of the gene contained sequences highly homologous to the RPG and Homol1 promoter elements found in S. cerevisiae. Southern blot analysis indicated that the Mucor genome contains three copies of this gene.