Efficacy of transcutaneous posterior tibial nerve stimulation in functional constipation.

Most children with functional constipation (FC) improve with conventional treatments. However, a proportion of children have poor treatment outcomes. Management of intractable FC may include botulinum toxin injections, transanal irrigation, antegrade enemas, colonic resections, and in some cases sacral nerve stimulation (SNS). SNS is surgically placed, not readily available and expensive. Posterior tibial nerve stimulation (PTNS) allows transmission of electronic impulses and retrograde stimulation to the sacral nerve plexus in a portable, simple and non-invasive fashion. To assess the efficacy and safety of transcutaneous PTNS for the treatment of FC in children. Single-center, prospective interventional study. Children 4-14 years with Rome IV diagnosis of FC received ten daily PTNS (30 min/day) sessions. Electrodes placed over skin of ankle. Strength of stimulus was below pain threshold. Outcomes were assessed during treatment and 7 days after. Twenty-three subjects enrolled. Two children excluded (acute gastroenteritis, COVID-19 contact). Twenty completed the study (4-14 years), (8.4 ± 3.2 years, 71.4% female). We found significant improvement in the consistency of bowel movements (BM) (p = 0.005), fecal incontinence (FI) (p = 0.005), abdominal pain presence (p = < 0.001) and intensity (p = 0.005), and a significant for improvement in blood in stools (p = 0.037). There was 86.3% improvement in abdominal pain. 96.7% reported treatment satisfaction. Only one child required rescue therapy. CONCLUSION: We found significant improvement in stool consistency, FI, abdominal pain, and hematochezia. This suggests that transcutaneous PTNS could be a promising noninvasive treatment for FC in children. Large studies are needed. WHAT IS KNOWN: • Functional constipation is one of the most common disorders in children. • Current management of functional constipation consists of an integrative approach that includes medications, diet and behavioral strategies. WHAT IS NEW: • Posterior tibial nerve stimulation is a novel noninvasive and easy to use therapy that can improve stool consistency, fecal incontinence and blood in stools.

Correction: Cuban history of CRF19 recombinant subtype of HIV-1.

[This corrects the article DOI: 10.1371/journal.ppat.1009786.].

Cuban history of CRF19 recombinant subtype of HIV-1.

CRF19 is a recombinant form of HIV-1 subtypes D, A1 and G, which was first sampled in Cuba in 1999, but was already present there in 1980s. CRF19 was reported almost uniquely in Cuba, where it accounts for ∼25% of new HIV-positive patients and causes rapid progression to AIDS (∼3 years). We analyzed a large data set comprising ∼350 pol and env sequences sampled in Cuba over the last 15 years and ∼350 from Los Alamos database. This data set contained both CRF19 (∼315), and A1, D and G sequences. We performed and combined analyses for the three A1, G and D regions, using fast maximum likelihood approaches, including: (1) phylogeny reconstruction, (2) spatio-temporal analysis of the virus spread, and ancestral character reconstruction for (3) transmission mode and (4) drug resistance mutations (DRMs). We verified these results with a Bayesian approach. This allowed us to acquire new insights on the CRF19 origin and transmission patterns. We showed that CRF19 recombined between 1966 and 1977, most likely in Cuban community stationed in Congo region. We further investigated CRF19 spread on the Cuban province level, and discovered that the epidemic started in 1970s, most probably in Villa Clara, that it was at first carried by heterosexual transmissions, and then quickly spread in the 1980s within the "men having sex with men" (MSM) community, with multiple transmissions back to heterosexuals. The analysis of the transmission patterns of common DRMs found very few resistance transmission clusters. Our results show a very early introduction of CRF19 in Cuba, which could explain its local epidemiological success. Ignited by a major founder event, the epidemic then followed a similar pattern as other subtypes and CRFs in Cuba. The reason for the short time to AIDS remains to be understood and requires specific surveillance, in Cuba and elsewhere.

Immunohistochemical localization of 3ß-Hydroxysteroid dehydrogenase and progesterone receptors in the ovary and placenta during gestation of the placentotrophic lizard Mabuya sp (Squamata: Scincidae).

In squamates, progesterone (P) plays a key role in the inhibition of uterine mobility during egg retention in oviparous species, and during gestation in viviparous species. The corpus luteum (CL) is the main organ responsible for the production of P; however, in some species, the CL degenerates early and the P needed for gestation maintenance should be produced in other tissues. Mabuya sp (Scincidae) is a viviparous lizard with a prolonged gestation, it produces microlecithal eggs and, consequently, has an obligate placentotrophy related with a highly complex placenta. Its CL degenerates at early stages of gestation and therefore, other sources of P should exist. The aim of this study was to determine and localize by immunohistochemistry the production of P by detection of the enzyme 3ß-Hydroxysteroid dehydrogenase (3ß-HSD) and P receptors (PR) during gestation in the ovary and placenta of Mabuya sp. Positive and negative control sections were used. The ovary of this species localizes 3ß-HSD and PR in the same tissues. The CL of the ovaries of females at early stages of gestation were positive for both molecules, whereas they did not localize from mid gestation to the end of pregnancy. Previtellogenic and vitellogenic follicles labelled for both molecules in the follicular epithelium and thecae. The placenta of Mabuya sp. demonstrated the potential for P production from mid gestation to the end of gestation in the uterine and chorionic tissues. PR were located in the uterine tissues throughout gestation, with a decrease towards its completion. Western blot analysis confirmed the presence of 3ß-HSD mainly in the ovary of early pregnant females and in the placental tissues at mid gestation stages. Therefore, the chorioallantoic placenta of Mabuya sp. has an endocrine function producing the P needed for gestation and replacing the CL from mid gestation to the end of pregnancy.

Helicobacter pylori from Peruvian amerindians: traces of human migrations in strains from remote Amazon, and genome sequence of an Amerind strain.

BACKGROUND: The gastric pathogen Helicobacter pylori is extraordinary in its genetic diversity, the differences between strains from well-separated human populations, and the range of diseases that infection promotes. PRINCIPAL FINDINGS: Housekeeping gene sequences from H. pylori from residents of an Amerindian village in the Peruvian Amazon, Shimaa, were related to, but not intermingled with, those from Asia. This suggests descent of Shimaa strains from H. pylori that had infected the people who migrated from Asia into The Americas some 15,000+ years ago. In contrast, European type sequences predominated in strains from Amerindian Lima shantytown residents, but with some 12% Amerindian or East Asian-like admixture, which indicates displacement of ancestral purely Amerindian strains by those of hybrid or European ancestry. The genome of one Shimaa village strain, Shi470, was sequenced completely. Its SNP pattern was more Asian- than European-like genome-wide, indicating a purely Amerind ancestry. Among its unusual features were two cagA virulence genes, each distinct from those known from elsewhere; and a novel allele of gene hp0519, whose encoded protein is postulated to interact with host tissue. More generally, however, the Shi470 genome is similar in gene content and organization to those of strains from industrialized countries. CONCLUSIONS: Our data indicate that Shimaa village H. pylori descend from Asian strains brought to The Americas many millennia ago; and that Amerind strains are less fit than, and were substantially displaced by, hybrid or European strains in less isolated communities. Genome comparisons of H. pylori from Amerindian and other communities should help elucidate evolutionary forces that have shaped pathogen populations in The Americas and worldwide.

Sputum PCR-single-strand conformational polymorphism test for same-day detection of pyrazinamide resistance in tuberculosis patients.

Pyrazinamide is a first-line drug for treating tuberculosis, but pyrazinamide resistance testing is usually too slow to guide initial therapy, so some patients receive inappropriate therapy. We therefore aimed to optimize and evaluate a rapid molecular test for tuberculosis drug resistance to pyrazinamide. Tuberculosis PCR-single-strand conformational polymorphism (PCR-SSCP) was optimized to test for mutations causing pyrazinamide resistance directly from sputum samples and Mycobacterium tuberculosis isolates. The reliability of PCR-SSCP tests for sputum samples (n = 65) and Mycobacterium tuberculosis isolates (n = 185) from 147 patients was compared with four tests for pyrazinamide resistance: Bactec-460 automated culture, the Wayne biochemical test, DNA sequencing for pncA mutations, and traditional microbiological broth culture. PCR-SSCP provided interpretable results for 96% (46/48) of microscopy-positive sputum samples, 76% (13/17) of microscopy-negative sputum samples, and 100% of Mycobacterium tuberculosis isolates. There was 100% agreement between PCR-SSCP results from sputum samples and Mycobacterium tuberculosis isolates and 100% concordance between 50 blinded PCR-SSCP rereadings by three observers. PCR-SSCP agreement with the four other tests for pyrazinamide resistance varied from 89 to 97%. This was similar to how frequently the four other tests for pyrazinamide resistance agreed with each other: 90 to 94% for Bactec-460, 90 to 95% for Wayne, 92 to 95% for sequencing, and 91 to 95% for broth culture. PCR-SSCP took less than 24 hours and cost approximately $3 to $6, in contrast with the other assays, which took 3 to 14 weeks and cost $7 to $47. In conclusion, PCR-SSCP is a relatively reliable, rapid, and inexpensive test for pyrazinamide resistance that indicates which patients should receive pyrazinamide from the start of therapy, potentially preventing months of inappropriate treatment.

Diagnosis of pediatric pulmonary tuberculosis by stool PCR.

Pediatric pulmonary tuberculosis diagnosis is difficult because young children are unable to expectorate sputum samples. Testing stool for tuberculosis DNA from swallowed sputum may diagnose pulmonary tuberculosis. Hospitalized children with suspected tuberculosis had stool, nasopharyngeal, and gastric aspirates cultured that confirmed pulmonary tuberculosis in 16/236 patients. Twenty-eight stored stools from these 16 children were used to evaluate stool polymerase chain reaction (PCR) for tuberculosis diagnosis compared with 28 stool samples from 23 healthy control children. Two DNA extraction techniques were used: fast-DNA mechanical homogenization and Chelex-resin chemical extraction. DNA was tested for tuberculosis DNA with a hemi-nested IS6110 PCR. PCR after Fast-DNA processing was positive for 6/16 culture-proven tuberculosis patients versus 5/16 after Chelex extraction (sensitivity 38% and 31%, respectively). All controls were negative (specificity 100%). If sensitivity can be increased, stool PCR would be a rapid, non-invasive, and relatively bio-secure initial test for children with suspected pulmonary tuberculosis.

DNA-level diversity and relatedness of Helicobacter pylori strains in shantytown families in Peru and transmission in a developing-country setting.

The efficiency of transmission of a pathogen within families compared with that between unrelated persons can affect both the strategies needed to control or eradicate infection and how the pathogen evolves. In industrialized countries, most cases of transmission of the gastric pathogen Helicobacter pylori seems to be from mother to child. An alternative model, potentially applicable among the very poor in developing countries, where infection is more common and the sanitary infrastructure is often deficient, invokes frequent transmission among unrelated persons, often via environmental sources. In the present study, we compared the genotypes of H. pylori from members of shantytown households in Peru to better understand the transmission of H. pylori in developing-country settings. H. pylori cultures and/or DNAs were obtained with informed consent by the string test (a minimally invasive alternative to endoscopy) from at least one child and one parent from each of 62 families. The random amplified polymorphic DNA fingerprints of 57 of 81 (70%) child-mother strain pairs did not match, nor did the diagnostic gene sequences (>1% DNA sequence difference), independent of the child's age (range, 1 to 39 years). Most strains from siblings or other paired family members were also unrelated. These results suggest that H. pylori infections are often community acquired in the society studied. Transmission between unrelated persons should facilitate the formation of novel recombinant genotypes by interstrain DNA transfer and selection for genotypes that are well suited for individual hosts. It also implies that the effective prevention of H. pylori infection and associated gastroduodenal disease will require anti-H. pylori measures to be applied communitywide.

Aspectos moleculares de la resistencia a pirazinamida en M. tuberculosis: implicancias para el desarrollo de nuevos métodos de diagnóstico y terapéutica / Molecular aspects of the resistance to pirazinamida in M. tuberculosis: implications for the development of new methods of diagnosis and therapeutics

Objetivo: Deseamos entender el polimorfismo del gen pirazinamidasa de M.tuberculosis en la población /peruana, y su correlación con las características ®estructura-función¼ de la enzima que codifica, para establecer los fundamentos moleculares del uso de técnicas de ADN para el diagnóstico de resistencia a PZA. Asimismo deseamos estudiar el efecto de altas concentraciones de Fe y Zn en la actividad enzimßtica de pncA como potenciadores de la terapia antituberculosa. Material y métodos: Hemos empleado la prueba MABA como la prueba referencia para comparar la técnica SSCP en la medición de la sus-ceptibilidada PZA. Adicionalmente hemos secuenciado el gen de pirazinamidasa de 20 cepas de M. tuberculosis y hemos determinado la actividad enzimßtica pirazinamidasa utilizando la prueba de Wayne. Para medir el efecto de los iones en la actividad enzimßtica, utilizamos la prueba de Wayne cuantitativa. Resultados: Hemos estudiado el polimorfismo del gen pncA utilizando secuenciamiento y el SSCP. Esta última técnica, sorprendentemente mostró unaimportante sensibilidad (92.9 por ciento y especificidad y un valor predictivo positivo de 93 por ciento para diagnosticar resistencia a PZA. Diversas mutaciones en el gen fueron detectadas en cepas resistentes a PZA,produciendo cambios de aminoßcidos asociados al sitio catalítico pero mayormente al sitio de coordinación del Zn, siendo la mutación D49N aparentemente la mßs prevalerte dentro de la población VIH positivos. Conclusiones: Las mutaciones mßs frecuentes asociadas a resistencia a PZA parecen afectar fundamentalmente la coordinación del Zn, frente a lo cual altas concentraciones de este ión, estimula la actividad pirazinamidasa, repotenciando el efecto de la PZA.