Pulmonary Sarcoidosis

Background: A 34-year-old male teacher was referred to the hospital with a persisting dry cough and dyspnea on exercise since eight weeks. He had no fever, neither complaints of ear, nose or throat. There were no complaints during the night. He had been a smoker until four months before presentation (12 pack years). At work a student was diagnosed with pulmonary tuberculosis, but the Mantoux and Quantiferon tests were negative. Physical examination was normal, without fever, lymphadenopathy or auscultation abnormalities. Laboratory investigation revealed a C-reactive protein of 2 mg/L. Pulmonary function testing showed a slight restriction. Immunological bronchial alveolar lavage (BAL) was rich of cells, especially T-lymphocytes of the CD4 type. CD4+/CD8+ ratio of the BAL was raised to 4.2, compared to a ratio of 2.4 in blood. There were no eosinophils found in the BAL. Conventional chest radiographs were performed, and showed multiple areas of consolidation in the bilateral lung fields, predominantly on the right side

The R" wave in V1 and the negative terminal QRS vector in aVF combine to a novel 12-lead ECG algorithm to identify slow conducting anatomical isthmus 3 in patients with tetralogy of Fallot

AimsPatients with repaired tetralogy of Fallot (rTOF) have an increased risk of ventricular tachycardia (VT), with slow conducting anatomical isthmus (SCAI) 3 as dominant VT substrate. In patients with right bundle branch block (RBBB), SCAI 3 leads to local activation delay with a shift of terminal RV activation towards the lateral RV outflow tract which may be detected by terminal QRS vector changes on sinus rhythm electrocardiogram (ECG).Methods and resultsConsecutive rTOF patients aged ≥16 years with RBBB who underwent electroanatomical mapping at our institution between 2017–2022 and 2010–2016 comprised the derivation and validation cohort, respectively. Forty-six patients were included in the derivation cohort (aged 40±15 years, QRS duration 165±23 ms). Among patients with SCAI 3 (n = 31, 67%), 17 (55%) had an R″ in V1, 18 (58%) had a negative terminal QRS portion (NTP) ≥80 ms in aVF, and 12 (39%) had both ECG characteristics, compared to only 1 (7%), 1 (7%), and 0 patient without SCAI, respectively.Combining R″ in V1 and/or NTP ≥80 ms in aVF into a diagnostic algorithm resulted in a sensitivity of 74% and specificity of 87% in detecting SCAI 3. The inter-observer agreement for the diagnostic algorithm was 0.875. In the validation cohort [n = 33, 18 (55%) with SCAI 3], the diagnostic algorithm had a sensitivity of 83% and specificity of 80% for identifying SCAI 3.ConclusionA sinus rhythm ECG-based algorithm including R″ in V1 and/or NTP ≥80 ms in aVF can identify rTOF patients with a SCAI 3 and may contribute to non-invasive risk stratification for VT.Cardiolog

Predictive value of lymphocytopenia and the neutrophil-lymphocyte count ratio for severe imported malaria

Background: Lymphocytopenia has frequently been described in patients with malaria, but studies on its association with disease severity have yielded conflicting results. The neutrophil/lymphocyte count ratio (NLCR) has been introduced as a parameter for systemic inflammation in critically ill patients and was found, together with lymphocytopenia, to be a better predictor of bacteraemia than routine parameters like C-reactive protein and total leukocyte count. In the present study, the predictive value of the NLCR and lymphocytopenia for severe disease was evaluated in patients with imported malaria. Methods. All patients diagnosed with malaria at the Harbour Hospital between January 1§ssup§st§esup§ 1999 and January 1§ssup§st§esup§ 2012 with differential white cell counts determined within the first 24 hours after admission were included in this retrospective study. Severe malaria was defined according to the WHO criteria. The performance of the NLCR and lymphocytopenia as a marker of severe malarial disease was compared back-to-back with that of C-reactive protein as a reference biomarker. Results: A total of 440 patients (severe falciparum malaria n = 61, non-severe falciparum malaria n = 259, non-falciparum malaria n=120) were included in the study. Lymphocytopenia was present in 52% of all patients and the median NLCR of all patients was 3.2. Total lymphocyte counts and NLCR did not differ significantly between groups. A significant correlation of total leukocyte count and NLCR, but not lymphocyte count, with parasitaemia was found. ROC analysis revealed a good negative predictive value but a poor positive predictive value of both lymphocytopenia and NLCR and performance was inferior to that of C-reactive protein. After complete parasite clearance a significant rise in total leukocyte count and lymphocyte count and a significant decrease in NLCR was observed. Conclusion: The NLCR was found to correlate with parasitaemia, but b

Validation of New Gene Variant Classification Methods:a Field-Test in Diagnostic Cardiogenetics

Background: In the molecular genetic diagnostics of Mendelian disorders, solutions are needed for the major challenge of dealing with the large number of variants of uncertain significance (VUSs) identified using next-generation sequencing (NGS). Recently, promising approaches using constraint metrics to calculate case excess scores (CE), etiological fractions (EF), and gnomAD-derived constraint scores have been reported that estimate the likelihood of rare variants in specific genes or regions that are pathogenic. Our objective is to study the usability of these constraint data into variant interpretation in a diagnostic setting, using our cardiomyopathy cohort. Methods and Results: Patients (N = 2002) referred for clinical genetic diagnostics underwent NGS testing of 55–61 genes associated with cardiomyopathies. Previously classified likely pathogenic (LP) and pathogenic (P) variants were used to validate the use of data from CE, EF, and gnomAD constraint analyses for (re)classification of associated variant types in specific cardiomyopathy subtype-related genes. The classifications corroborated in 94% (354/378) of cases. Next, we reclassified 23 unique VUSs to LP, increasing the diagnostic yield by 1.2%. In addition, 106 unique VUSs (5.3% of patients) were prioritized for co-segregation or functional analyses. Conclusions: Our analysis confirms that the use of constraint metrics data can improve variant interpretation, and we, therefore, recommend using constraint scores on other cohorts and disorders and its inclusion in variant interpretation protocols

Environmental Salinity Determines the Specificity and Need for Tat-Dependent Secretion of the YwbN Protein in Bacillus subtilis

Twin-arginine protein translocation (Tat) pathways are required for transport of folded proteins across bacterial, archaeal and chloroplast membranes. Recent studies indicate that Tat has evolved into a mainstream pathway for protein secretion in certain halophilic archaea, which thrive in highly saline environments. Here, we investigated the effects of environmental salinity on Tat-dependent protein secretion by the Gram-positive soil bacterium Bacillus subtilis, which encounters widely differing salt concentrations in its natural habitats. The results show that environmental salinity determines the specificity and need for Tat-dependent secretion of the Dyp-type peroxidase YwbN in B. subtilis. Under high salinity growth conditions, at least three Tat translocase subunits, namely TatAd, TatAy and TatCy, are involved in the secretion of YwbN. Yet, a significant level of Tat-independent YwbN secretion is also observed under these conditions. When B. subtilis is grown in medium with 1% NaCl or without NaCl, the secretion of YwbN depends strictly on the previously described “minimal Tat translocase” consisting of the TatAy and TatCy subunits. Notably, in medium without NaCl, both tatAyCy and ywbN mutants display significantly reduced exponential growth rates and severe cell lysis. This is due to a critical role of secreted YwbN in the acquisition of iron under these conditions. Taken together, our findings show that environmental conditions, such as salinity, can determine the specificity and need for the secretion of a bacterial Tat substrate

Efficacy of OptiphosTM phytase on mineral digestibility in diets for breeding sows: effect during pregnancy an lactation

Phosphorus in most diets for breeding sows is digested for 20 to 40%, thus leading to a relatively high amount of P in the manure. To enhance the P digestibility in diets for both lactating and gestating sows, two separate experiments were carried out to study the efficacy of OptiphosTM phytase derived from E. coli and produced by the yeast Pichia pastoris. Thirty crossbred gestating sows and 36 lactating sows were used in these studies. Five treatments were imposed on the gestating sows: 1) a negative control treatment, based on a low-P diet without added feed phosphate and microbial phytase. Diets in Treatments 2, 3 and 4 were the same as the negative control diet, except that an amount of Optiphos phytase of 125, 250 and 1,000 U.kg-1 of diet, respectively, was added. Treatment 5 was the positive control diet, based on the same diet with 1.0 g of added digestible P.kg-1 of diet from monocalcium phosphate. The lactating sows of Treatments 1 to 6 received a negative control diet, the same diet with an amount of OptiphosTM phytase of 125, 250, 500 and 1000 U.kg-1 of diet and a positive control diet supplemented with 1.5 g of digestible P.kg-1, respectively. The negative control diets were different in ingredient composition because of the different nutrient requirements between lactating and gestating sows. The ratio between Ca and digestible P was kept at 2.8:1 and 3.3:1 for the lactating and gestating diets, respectively, with a minimum of 5.0 g Ca.kg-1. Feeding level of the sows was according to Dutch recommendations. Six sows per treatment were used. The lactating sows received the diets from 2 weeks before farrowing until weaning of the piglets at 4 weeks of age and the gestating sows from day 49 to day 100 of pregnancy. Faecal samples of the sows were collected by rectal stimulation on days 14 and 21 post-farrowing, and on days 70 and 100 of pregnancy. Digestibility coefficients of dry matter, organic matter, ash and the minerals under investigation were calculated using Cr2O3 as an indigestible marker. In addition, several performance characteristics were registered. Phosphorus digestibility was clearly enhanced by the addition of microbial phytase to the lactating sow diets, as was the digestibility of ash, Ca, Na, K, Cu, and Zn. In the gestating sows only digestibility of P was significantly enhanced by microbial phytase. In both gestating and lactating sows the lowest level of phytase addition (125 U.kg-1 of diet) already resulted in the highest response in P digestibility without further improvement at higher phytase inclusion levels. The additional amount of digestible P absorbed with a phytase supplement of 125 or more U.kg-1 in lactating sows was on average 0.90 g/kg. An average amount of 0.36 and 0.67 g digestible P.kg-1 was generated in gestating sows at day 70 and day 100 of pregnancy by this phytase inclusion, respectively. No signs of any adverse effect of phytase on sow or piglet health and performance were observed. OptiphosTM phytase was already highly effective at a dose of 125 U.kg-1 of diet. Possible reasons for the lack of further improvement of P digestibility at higher doses of phytase are discussed. If feed phosphates are (partly) replaced by 125 U phytase.kg-1 of diet, then P excretion can be reduced by 0.85 kg.sow-1.year-1

Phylogeographic Patterns in Africa and High Resolution Delineation of Genetic Clades in the Lion (Panthera leo)

Comparative phylogeography of African savannah mammals shows a congruent pattern in which populations in West/Central Africa are distinct from populations in East/Southern Africa. However, for the lion, all African populations are currently classified as a single subspecies (Panthera leo leo), while the only remaining population in Asia is considered to be distinct (Panthera leo persica). This distinction is disputed both by morphological and genetic data. In this study we introduce the lion as a model for African phylogeography. Analyses of mtDNA sequences reveal six supported clades and a strongly supported ancestral dichotomy with northern populations (West Africa, Central Africa, North Africa/Asia) on one branch, and southern populations (North East Africa, East/Southern Africa and South West Africa) on the other. We review taxonomies and phylogenies of other large savannah mammals, illustrating that similar clades are found in other species. The described phylogeographic pattern is considered in relation to large scale environmental changes in Africa over the past 300,000 years, attributable to climate. Refugial areas, predicted by climate envelope models, further confirm the observed pattern. We support the revision of current lion taxonomy, as recognition of a northern and a southern subspecies is more parsimonious with the evolutionary history of the lion.Netherlands Organization for Scientific Research (NWO) (project no. 820.01.002)