Phylogenomic reconstruction of Cryptosporidium spp. captured directly from clinical samples reveals extensive genetic diversity.

Cryptosporidium is a leading cause of severe diarrhea and mortality in young children and infants in Africa and southern Asia. More than twenty Cryptosporidium species infect humans, of which C. parvum and C. hominis are the major agents causing moderate to severe diarrhea. Relatively few genetic markers are typically applied to genotype and/or diagnose Cryptosporidium. Most infections produce limited oocysts making it difficult to perform whole genome sequencing (WGS) directly from stool samples. Hence, there is an immediate need to apply WGS strategies to 1) develop high-resolution genetic markers to genotype these parasites more precisely, 2) to investigate endemic regions and detect the prevalence of different genotypes, and the role of mixed infections in generating genetic diversity, and 3) to investigate zoonotic transmission and evolution. To understand Cryptosporidium global population genetic structure, we applied Capture Enrichment Sequencing (CES-Seq) using 74,973 RNA-based 120 nucleotide baits that cover ~92% of the genome of C. parvum. CES-Seq is sensitive and successfully sequenced Cryptosporidium genomic DNA diluted up to 0.005% in human stool DNA. It also resolved mixed strain infections and captured new species of Cryptosporidium directly from clinical/field samples to promote genome-wide phylogenomic analyses and prospective GWAS studies.

Post-COVID-19 tomographic abnormalities.

BACKGROUND: The prevalence of persistent respiratory symptoms tends to be low in patients with a longer recovery time after COVID-19. However, some patients may present persistent pulmonary abnormalities.OBJECTIVE: To evaluate the prevalence of tomographic abnormalities 90 days after symptom onset in patients with COVID-19 and compare two chest high-resolution computed tomography (HRCT) analysis techniques.METHODS: A multicentre study of patients hospitalised with COVID-19 having oxygen saturation <93% on room air at hospital admission were evaluated using pulmonary function and HRCT scans 90 days after symptom onset. The images were evaluated by two thoracic radiologists, and were assessed using software that automatically quantified the extent of pulmonary abnormalities.RESULTS: Of the 91 patients included, 81% had at least one pulmonary lobe with abnormalities 90 days after discharge (84% were identified using the automated algorithm). Ground-glass opacities (76%) and parenchymal bands (65%) were the predominant abnormalities. Both chest HRCT technical assessments presented high sensitivity (95.9%) and positive predictive value (92%), with a statistically significant correlation at baseline (R = 0.80) and after 90 days (R = 0.36).CONCLUSION: The prevalence of pulmonary abnormalities on chest HRCT 90 days after symptom onset due to COVID-19 was high; both technical assessments can be used to analyse the images.

Systematic functional analysis of Leishmania protein kinases identifies regulators of differentiation or survival.

Differentiation between distinct stages is fundamental for the life cycle of intracellular protozoan parasites and for transmission between hosts, requiring stringent spatial and temporal regulation. Here, we apply kinome-wide gene deletion and gene tagging in Leishmania mexicana promastigotes to define protein kinases with life cycle transition roles. Whilst 162 are dispensable, 44 protein kinase genes are refractory to deletion in promastigotes and are likely core genes required for parasite replication. Phenotyping of pooled gene deletion mutants using bar-seq and projection pursuit clustering reveal functional phenotypic groups of protein kinases involved in differentiation from metacyclic promastigote to amastigote, growth and survival in macrophages and mice, colonisation of the sand fly and motility. This unbiased interrogation of protein kinase function in Leishmania allows targeted investigation of organelle-associated signalling pathways required for successful intracellular parasitism.

Incremental step test in patients with pulmonary hypertension.

Cardiopulmonary exercise testing (CPET) on a treadmill or cycle ergometer provides an integrated assessment of the cardiorespiratory system during exertion and is widely used in clinical practice. An incremental step test (IST) can be an alternative for eliciting maximal exercise responses. Therefore, 20 patients with pre-capillary PH (65% female, 41 ±â€¯15 yrs) randomly performed a symptom-limited CPET on a cycle ergometer and IST. Metabolic, cardiovascular, ventilatory and gas exchange variables were recorded during both tests. There was a greater desaturation and higher V̇O2PEAK in IST compared to CPET. The V̇O2GET, HR PEAK (% pred), ΔV̇E/ΔV̇CO2 and ΔHR/ΔV̇O2 were similar in both IST and CPET. By linear regression analyses, the work performed on IST [W = (mass × 9,8 m/s2 x vertical distance)] was a predictor of peak V̇O2 independent of the gender and age (r2 = 077, p = 0001). In conclusion, IST elicited higher peak cardiopulmonary responses and has a good agreement with known severity markers in patients with pre-capillary PH.

Clinical usefulness of end-tidal CO2 profiles during incremental exercise in patients with chronic thromboembolic pulmonary hypertension.

INTRODUCTION: Great ventilation to carbon dioxide output (ΔV˙E/ΔV˙CO2) and reduced end-tidal partial pressures for CO2 (PetCO2) during incremental exercise are hallmarks of chronic thromboembolic pulmonary hypertension (CTEPH) and idiopathic pulmonary arterial hypertension (IPAH). However, CTEPH is more likely to involve proximal arteries, which may lead to poorer right ventricle-pulmonary vascular coupling and worse gas exchange abnormalities. Therefore, abnormal PetCO2 profiles during exercise may be more prominent in patients with CTEPH and could be helpful to indicate disease severity. METHODS: Seventy patients with CTEPH and 34 with IPAH underwent right heart catheterization and cardiopulmonary exercise testing. According to PetCO2 pattern during exercise, patients were classified as having an increase or stabilization in PetCO2 up to the gas exchange threshold (GET), an abrupt decrease in the rest-exercise transition or a progressive and slow decrease throughout exercise. A subgroup of patients with CTEPH underwent a constant work rate exercise test to obtain arterial blood samples during steady-state exercise. RESULTS: Multivariate logistic regression analyses showed that progressive decreases in PetCO2 and SpO2 were better discriminative parameters than ΔV˙E/ΔV˙CO2 to distinguish CTEPH from IPAH. This pattern of PetCO2 was associated with worse functional impairment and greater reduction in PaCO2 during exercise. CONCLUSION: Compared to patients with IPAH, patients with CTEPH present more impaired gas exchange during exercise, and PetCO2 abnormalities may be used to identify more clinically and hemodynamically severe cases.

Prevalência de nódulos de tireóide detectados por ecografia em mulheres após os 40 anos / Prevalence of thyroid nodules in 40 years-old or old women

Nódulos de tireóide säo uma condiçäo clínica comum e em seu diagnóstico diferencial inclui-se o câncer de tireóide. Como o câncer de tireóide é raro, é importante conhecer a prevalência de nódulos de tireóide em grupos fortemente pre-dispostos para dimensionar seu impacto e adequar estratégias diagnósticas. OBJETIVOS: O objetivo deste estudo foi verificar a prevalência de nódulos de tireóide diagnosticados por ecografia em mulheres na maturidade. MÉTODOS: Entre agosto de 1996 e dezembro de 1997 foram avaliadas, de forma consecutiva, pacientes do sexo feminino com idade de 40 anos ou mais que realizavam ecografia no Serviço de Radiologia do HCPA...

[Prevalence of thyroid nodules in 40 years-old or old women]. / Prevalência de nódulos de tireóide detectados por ecografia em mulheres após os 40 anos.

OBJECTIVES: Thyroid nodules constitute a very common clinical problem and the differential diagnosis includes thyroid cancer. As thyroid cancer is rare, it is important to know the prevalence of thyroid nodules in cohorts strongly predisposed to this problem to be able to measure its impact on the health care system, and to devise appropriate diagnostic strategies. The aim of this study was to determine the prevalence of thyroid nodules in women 40 year-old or older by echography. METHODS: Between August 1996 and December 1997, 207 women, 40 year-old or older, were consecutively evaluated by thyroid echography in the Radiology Division of the Hospital de Clínicas de Porto Alegre. Patients who came to the Division to be submitted to thyroid echography were excluded. The mean age of patients studied was 54.7 years (median: 53, range: 40-86 years). One hundred and twenty three patients (54.9%) had a normal thyroid and eighty-two had an abnormal gland (39.6%). Thyroid nodules were detected in seventy-three women (35.3%) and these were larger than 1 cm in 35 women (16.9%). Women without thyroid nodules were younger (53.1 +/-10.7 years) than women with thyroid nodules (58.2 +/-10.6 years) p=0.001; and the prevalence of any thyroid nodule (p=0.001) or nodules larger than 1 cm (p=0.007) increased with age. CONCLUSIONS: Thyroid nodules are very common in women 40 year-old or older, their prevalence increases with age in this cohort and these nodules are potentially palpable (larger than one cm) in one of six women in this age group It is important to have these data in mind when ordering thyroid echographic studies in women 40 year-old or older.