Right ventricular systolic pressure by echocardiography as a predictor of pulmonary hypertension in idiopathic pulmonary fibrosis

RATIONALE: Pulmonary hypertension (PH) commonly complicates the course of patients with idiopathic pulmonary fibrosis (IPF). It has a significant impact on outcomes and is, therefore, important to detect. OBJECTIVES: We sought to characterize the accuracy and performance characteristics of the right ventricular systolic pressure (RVSP) as estimated by echocardiography (ECHO) alone and in conjunction with physiologic indices in predicting the presence of PH in IPF patients. METHODS: Cross-sectional study of IPF patients from two large tertiary centers in whom both ECHO and right-heart catheterization (RHC) were available. MEASUREMENTS AND MAIN RESULTS: There were 110 patients with available ECHOs and RHCs. Estimates of RVSP were reported in 60 of these patients (54.5%) of whom 22 (36.6%) had PH, while 16 of the 50 patients without RVSP estimate (32%) had PH. Twenty-four of 60 (40%) ECHOs accurately reflected the pulmonary arterial systolic pressure as measured by RHC. An optimal RVSP threshold for the screening of PH could not be detected. When assessed in combination with various thresholds of PFT and 6-minute walk test (6MWT) parameters, the performance characteristics of the RVSP were slightly improved. CONCLUSION: The RVSP is not an accurate test for the assessment of PH in IPF patients. Awareness of the various combinations of threshold values for RVSP with and without PFT and 6MWT might nonetheless assist clinicians in risk stratifying IPF patients for the presence of PH.     

A deep sequencing tool for partitioning clearance rates following antimalarial treatment in polyclonal infections

Background and objectives: Current tools struggle to detect drug-resistant malaria parasites when infections contain multiple parasite clones, which is the norm in high transmission settings in Africa. Our aim was to develop and apply an approach for detecting resistance that overcomes the challenges of polyclonal infections without requiring a genetic marker for resistance.Methodology: Clinical samples from patients treated with artemisinin combination therapy were collected from Tanzania and Cambodia. By deeply sequencing a hypervariable locus, we quantified the relative abundance of parasite subpopulations (defined by haplotypes of that locus) within infections and revealed evolutionary dynamics during treatment. Slow clearance is a phenotypic, clinical marker of artemisinin resistance; we analyzed variation in clearance rates within infections by fitting parasite clearance curves to subpopulation data.Results: In Tanzania, we found substantial variation in clearance rates within individual patients. Some parasite subpopulations cleared as slowly as resistant parasites observed in Cambodia. We evaluated possible explanations for these data, including resistance to drugs. Assuming slow clearance was a stable phenotype of subpopulations, simulations predicted that modest increases in their frequency could substantially increase time to cure.Conclusions and implications: By characterizing parasite subpopulations within patients, our method can detect rare, slow clearing parasites in vivo whose phenotypic effects would otherwise be masked. Since our approach can be applied to polyclonal infections even when the genetics underlying resistance are unknown, it could aid in monitoring the emergence of artemisinin resistance. Our application to Tanzanian samples uncovers rare subpopulations with worrying phenotypes for closer examination.     

Palatal evaluation and treatment in 22q11.2 deletion syndrome

Palatal involvement occurs commonly in patients with 22q11.2 Deletion Syndrome (22qDS), and includes palatal clefting and velopharyngeal dysfunction in the absence of overt or submucous clefts. The reported incidence and distribution of palatal abnormalities vary in the literature. The aim of this article is to revisit the incidence and presenting features of palatal abnormalities in a large cohort of patients with 22qDS, summarize the surgical treatments performed in this cohort, and provide an overview of surgical treatment protocols and management guidelines for palatal abnormalities in this syndrome. Charts of 1,121 patients seen through the 22q and You Center at the Children's Hospital of Philadelphia were reviewed for palatal status, demographic factors, deletion size, and corrective surgical procedures. Statistical analysis was performed using Pearson's chi‐squared test to identify differences between gender, deletion size, and palatal abnormality. Of the patients with complete evaluations, 67% were found to have a palatal abnormality. The most common finding was velopharyngeal dysfunction in 55.2% of patients, and in 33.3% of patients, this occurred in the absence of palatal clefting. There was no significant difference in the incidence of palatal abnormalities by gender; however, a difference was noted among race (p < 0.01) and deletion sizes (p < 0.01). For example, Caucasian and Asian patients presented with a much higher prevalence of palatal abnormalities, and conversely those with nested deletions presented with a much lower rate of palatal defects. Overall, 26.9% of patients underwent palatal surgery, and the most common indication was velopharyngeal dysfunction. Palatal abnormalities are a hallmark feature of 22q11.2 Deletion Syndrome; understanding the incidence, presenting features, and treatment protocols are essential for practitioners counseling and treating families affected with this disorder.     

Identification of an ARS element and development of a high efficiency transformation system for Pichia guilliermondii

An Autonomously Replicating Sequence element adjacent to the RIB1 gene encoding GTP cyclohydrolase II of the yeast Pichia guilliermondii was identified by transformation experiments. Detailed sequence analysis unveiled two potential ARS elements located 5′ and 3′ of the RIB1 open reading frame. The chromosomal fragment containing the ARS-like sequence 3′ to the RIB1 structural gene, called PgARS, conferred high transformation frequencies of 10⁴–10⁵ transformants/μg of DNA to a pUC19-derived plasmid in P. guilliermondii. The PgARS element also conferred autonomous replication to hybrid plasmids in this host. Based on this element a series of Escherichia coli shuttle vectors for efficient transformation of the flavinogenic yeast P. guilliermondii was developed. Received: 22 September 1998 / 1 June 1999     

Tourniquet-induced Changes of Energy Metabolism in Human Skeletal Muscle Monitored by Microdialysis

Background: Tourniquets are often used as part of orthopedic surgery but may cause local and remote organ injury. The authors hypothesized that the procedures used to induce ischemia (circulatory occlusion or exsanguination) may have differential effects on the metabolic state of the muscle that should be reflected in the interstitial levels of metabolites.

Methods: Microdialysis probes were implanted in both quadriceps femoris muscles of 18 patients. Interstitial fluid was obtained during tourniquet-induced ischemia and reperfusion and was analyzed for glucose, lactate, choline, and purines by high-performance liquid chromatography.

Results: At a flow rate of 2 [mu]l/min, the average baseline concentrations in the dialysate were 2.5 mm for glucose, 1.7 mm for lactate, 5.2 [mu]m for choline, and 14.3 [mu]m for hypoxanthine. Circulatory occlusion by tourniquet caused a 40% decrease of the extracellular glucose concentration within 30 min. Concomitantly, the interstitial levels of lactate and hypoxanthine increased in a linear fashion to 206% (lactate) and 241% (hypoxanthine) of basal values. The extracellular concentration of choline was also significantly elevated. After exsanguination, the glucose levels were significantly more reduced (by 65%), and the levels of lactate (to 268%) and hypoxanthine (to 286%) were more increased than after circulatory occlusion alone.     

A Case for Offering HPV Self-Sampling to Well-Screened Women. Comment on Lesack et al. Willingness to Self-Collect a Sample for HPV-Based Cervical Cancer Screening in a Well-Screened Cohort: HPV FOCAL Survey Results. Curr. Oncol. 2022, 29, 3860–3869

Lesack et al. recently published a cross-sectional study that focused on human papillomavirus (HPV) self-sampling in the screened population, a population not conventionally thought of for HPV self-sampling. They found 52% of well-screened, highly educated women who participated in the Human Papillomavirus For Cervical Cancer (HPV FOCAL) screening trial in British Columbia, Canada, would be willing to self-collect an HPV sample. We published a similar study in 2021 on well-screened, highly educated women affiliated with a family medicine clinic in Edmonton, Alberta, Canada, and found that 60% of these women preferred to have the option of HPV self-sampling. Our findings reinforce Lesack et al.’s results and together provide evidence for offering HPV self-sampling as an option for the well-screened population.