Genome Assembly of Pyrocephalus nanus: A Step Toward the Genetic Conservation of the Endangered Little Vermilion Flycatcher of the Galapagos Islands

Incredibly powerful whole genome studies of conservation genetics, evolution, and biogeography become possible for non-model organisms when reference genomes are available. Here, we report the sequence and assembly of the whole genome of the little vermilion flycatcher (Pyrocephalus nanus; family Tyrannidae), which is an endemic, endangered, and declining species of the Galapagos Islands. Using PacBio HiFi reads to assemble long contigs and Hi-C reads for scaffolding, we assembled a genome of 1.07 Gb comprising 267 contigs in 152 scaffolds, scaffold N50 74 M, contig N50 17.8 M, with 98.9% assigned to candidate chromosomal sequences and 99.72% of the BUSCO passeriformes 10,844 single-copy orthologs present. In addition, we used the novel HiFiMiTie pipeline to fully assemble and verify all portions of the mitochondrial genome from HiFi reads, obtaining a mitogenome of 17,151 bases, containing 13 protein-coding genes, 22 tRNAs, 2 rRNAs, two control regions, and a unique structure of control region duplication and repeats. These genomes will be a critical tool for much-needed studies of phylogenetics, population genetics, biogeography, and conservation genetics of Pyrocephalus and related genera. This genome and other studies that use it will be able to provide recommendations for conservation management, taxonomic improvement, and to understand the evolution and diversification of this genus within the Galapagos Islands.

High-Quality, Chromosome-Level Reference Genomes of the Viviparous Caribbean Skinks Spondylurus nitidus and S. culebrae

New World mabuyine skinks are a diverse radiation of morphologically cryptic lizards with unique reproductive biologies. Recent studies examining population-level data (morphological, ecological, and genomic) have uncovered novel biodiversity and phenotypes, including the description of dozens of new species and insights into the evolution of their highly complex placental structures. Beyond the potential for this diverse group to serve as a model for the evolution of viviparity in lizards, much of the taxonomic diversity is concentrated in regions experiencing increasing environmental instability from climate and anthropogenic change. Consequently, a better understanding of genome structure and diversity will be an important tool in the adaptive management and conservation of this group. Skinks endemic to Caribbean islands are particularly vulnerable to global change with several species already considered likely extinct and several remaining species either endangered or threatened. Combining PacBio long-read sequencing, Hi-C, and RNAseq data, here we present the first genomic resources for this group by describing new chromosome-level reference genomes for the Puerto Rican Skink Spondylurus nitidus and the Culebra Skink S. culebrae. Results indicate two high quality genomes, both ∼1.4 Gb, assembled nearly telomere to telomere with complete mitochondrion assembly and annotation.

Comparative genomics of symbiotic Photobacterium using highly contiguous genome assemblies from long read sequences

This study presents the assembly and comparative genomic analysis of luminous Photobacterium strains isolated from the light organs of 12 fish species using Oxford Nanopore Technologies (ONT) sequencing. The majority of assemblies achieved chromosome-level continuity, consisting of one large (>3 Mbp) and one small (~1.5 Mbp) contig, with near complete BUSCO scores along with varying plasmid sequences. Leveraging this dataset, this study significantly expanded the available genomes for P. leiognathi and its subspecies P. 'mandapamensis', enabling a comparative genomic analysis between the two lineages. An analysis of the large and small chromosomes unveiled distinct patterns of core and accessory genes, with a larger fraction of the core genes residing on the large chromosome, supporting the hypothesis of secondary chromosome evolution from megaplasmids in Vibrionaceae. In addition, we discovered a proposed new species, Photobacterium acropomis sp. nov., isolated from an acropomatid host, with an average nucleotide identify (ANI) of 93 % compared to the P. leiognathi and P. 'mandapamensis' strains. A comparison of the P. leiognathi and P. 'mandapamensis' lineages revealed minimal differences in gene content, yet highlighted the former's larger genome size and potential for horizontal gene transfer. An investigation of the lux-rib operon, responsible for light production, indicated congruence between the presence of luxF and host family, challenging its role in differentiating P. 'mandapamensis' from P. leiognathi. Further insights were derived from the identification of metabolic differences, such as the presence of the NADH:quinone oxidoreductase respiratory complex I in P. leiognathi as well as variations in the type II secretion system (T2S) genes between the lineages, potentially impacting protein secretion and symbiosis. In summary, this study advances our understanding of Photobacterium genome evolution, highlighting subtle differences between closely related lineages, specifically P. leiognathi and P. 'mandapamensis'. These findings highlight the benefit of long read sequencing for bacterial genome assembly and pangenome analysis and provide a foundation for exploring early bacterial speciation processes of these facultative light organ symbionts.

Renal Dysfunction and Arrhythmia Association in Patients Receiving Milrinone After Cardiac Surgery

OBJECTIVE

The altered pharmacokinetics of milrinone in renal impairment could result in an increased risk of cardiac arrhythmias. This study aimed to determine if there is an association between new-onset arrhythmias and renal impairment after cardiac surgery following milrinone administration.

DESIGN

A retrospective cohort study.

SETTING

A single-center tertiary care hospital.

PARTICIPANTS

Adult patients who received a milrinone infusion in the intensive care unit (ICU) setting after coronary artery bypass graft, valvuloplasty, annuloplasty, or a combination of these surgeries from July 1, 2014 to July 1, 2021. Renal impairment was defined using a creatinine clearance <60 mL/min, calculated using the Cockcroft-Gault equation.

INTERVENTIONS

Patients received a weight-based continuous intravenous infusion of milrinone.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the presence of new arrhythmias after the initial administration of a weight-based continuous intravenous infusion of milrinone postcardiac surgery. Of the 197 patients who met inclusion, there was no difference in the presence of new arrhythmias (42.9% v 40.3%, p = 0.76) or in the time to first new arrhythmia from milrinone initiation in those with renal impairment compared to those without renal impairment (29.1 hours v 33.3 hours, p = 0.54). Patients with renal impairment had a longer hospital stay than patients without renal impairment (17.5 days v 13.9 days, p = 0.016). Arrhythmia type, length of ICU stay, ICU mortality, and hospital mortality were not different between the cohorts.

CONCLUSIONS

There was no association between new arrhythmias, milrinone, and renal impairment in patients postcardiac surgery.

Chromosome-level genome assembly of the bioluminescent cardinalfish Siphamia tubifer, an emerging model for symbiosis research

The bioluminescent symbiosis involving the sea urchin cardinalfish Siphamia tubifer and the luminous bacterium Photobacterium mandapamensis is an emerging vertebrate model for the study of microbial symbiosis. However, little genetic data are available for the host, limiting the scope of research that can be implemented with this association. We present a chromosome-level genome assembly for S. tubifer using a combination of PacBio HiFi sequencing and Hi–C technologies. The final assembly was 1.2 Gb distributed on 23 chromosomes and contained 32,365 protein coding genes with a BUSCO score of 99%. A comparison of the S. tubifer genome to that of another nonluminous species of cardinalfish revealed a high degree of synteny, whereas a comparison to a more distant relative in the sister order Gobiiformes revealed the fusion of two chromosomes in the cardinalfish genomes. The complete mitogenome of S. tubifer was also assembled, and an inversion in the vertebrate WANCY tRNA genes as well as heteroplasmy in the length of the control region were discovered. A phylogenetic analysis based on whole the mitochondrial genome indicated that S. tubifer is divergent from the rest of the cardinalfish family, highlighting the potential role of the bioluminescent symbiosis in the initial divergence of Siphamia. This high-quality reference genome will provide novel opportunities for the bioluminescent S. tubifer–P. mandapamensis association to be used as a model for symbiosis research.

Type 2 Diabetes Management, Control and Outcomes During the COVID-19 Pandemic in Older US Veterans: an Observational Study

BACKGROUND

The COVID-19 pandemic required a change in outpatient care delivery models, including shifting from in-person to virtual visits, which may have impacted care of vulnerable patients.

OBJECTIVE

To describe the changes in management, control, and outcomes in older people with type 2 diabetes (T2D) associated with the shift from in-person to virtual visits.

DESIGN AND PARTICIPANTS

In veterans aged ≥ 65 years with T2D, we assessed the rates of visits (in person, virtual), A1c measurements, antidiabetic deintensification/intensification, ER visits and hospitalizations (for hypoglycemia, hyperglycemia, other causes), and A1c level, in March 2020 and April-November 2020 (pandemic period). We used negative binomial regression to assess change over time (reference: pre-pandemic period, July 2018 to February 2020), by baseline Charlson Comorbidity Index (CCI; > 2 vs. <= 2) and A1c level.

KEY RESULTS

Among 740,602 veterans (mean age 74.2 [SD 6.6] years), there were 55% (95% CI 52-58%) fewer in-person visits, 821% (95% CI 793-856%) more virtual visits, 6% (95% CI 1-11%) fewer A1c measurements, and 14% (95% CI 10-17%) more treatment intensification during the pandemic, relative to baseline. Patients with CCI > 2 had a 14% (95% CI 12-16%) smaller relative increase in virtual visits than those with CCI <= 2. We observed a seasonality of A1c level and treatment modification, but no association of either with the pandemic. After a decrease at the beginning of the pandemic, there was a rebound in other-cause (but not hypo- and hyperglycemia-related) ER visits and hospitalizations from June to November 2020.

CONCLUSION

Despite a shift to virtual visits and a decrease in A1c measurement during the pandemic, we observed no association with A1c level or short-term T2D-related outcomes, providing some reassurance about the adequacy of virtual visits. Further studies should assess the longer-term effects of shifting to virtual visits in different populations to help individualize care, improve efficiency, and maintain appropriate care while reducing overuse.

Association of tacrolimus time-to-therapeutic range on renal dysfunction and acute cellular rejection after orthotopic heart transplantation in a high use basiliximab population

BACKGROUND

Currently, clinicians often delay initiation of tacrolimus after orthotopic heart transplantation (OHT) to help mitigate nephrotoxicity. This study aimed to determine if there is an association between the time-to-therapeutic range (TTT) of tacrolimus, early renal dysfunction, and acute cellular rejection (ACR) after OHT.

METHODS

This was a retrospective, single center study with adult patients who underwent OHT from July 2013 to April 2020. Logistic regression analysis was utilized to examine the association of TTT with new renal dysfunction after tacrolimus initiation post-OHT.

RESULTS

In a study of 317 patients, the unadjusted analysis showed patients who developed new renal dysfunction after tacrolimus initiation had a numerically shorter TTT (9.5 vs. 11.0 days, P = .065), and were more likely to have supratherapeutic tacrolimus levels (56% vs. 39.2%, P = .010). When adjusted for established risk factors for renal dysfunction, TTT was significantly associated with new renal dysfunction (OR .95; 95% CI [.90, .99], P = .03). There was no association between TTT and the incidence of ACR (11.1 vs. 10.8 days, P = .64).

CONCLUSION

When adjusting for known risk factors, a shorter TTT was associated with new renal dysfunction. Supratherapeutic tacrolimus levels were also associated with new renal dysfunction. There was no association between TTT and ACR in the setting of high use basiliximab induction.

The Easter Egg Weevil (Pachyrhynchus) genome reveals syntenic patterns in Coleoptera across 200 million years of evolution

Patterns of genomic architecture across insects remain largely undocumented or decoupled from a broader phylogenetic context. For instance, it is unknown whether translocation rates differ between insect orders. We address broad scale patterns of genome architecture across Insecta by examining synteny in a phylogenetic framework from open-source insect genomes. To accomplish this, we add a chromosome level genome to a crucial lineage, Coleoptera. Our assembly of the Pachyrhynchus sulphureomaculatus genome is the first chromosome scale genome for the hyperdiverse Phytophaga lineage and currently the largest insect genome assembled to this scale. The genome is significantly larger than those of other weevils, and this increase in size is caused by repetitive elements. Our results also indicate that, among beetles, there are instances of long-lasting (>200 Ma) localization of genes to a particular chromosome with few translocation events. While some chromosomes have a paucity of translocations, intra-chromosomal synteny was almost absent, with gene order thoroughly shuffled along a chromosome. This large amount of reshuffling within chromosomes with few inter-chromosomal events contrasts with patterns seen in mammals in which the chromosomes tend to exchange larger blocks of material more readily. To place our findings in an evolutionary context, we compared syntenic patterns across Insecta in a phylogenetic framework. For the first time, we find that synteny decays at an exponential rate relative to phylogenetic distance. Additionally, there are significant differences in decay rates between insect orders, this pattern was not driven by Lepidoptera alone which has a substantially different rate.

Predictive Modeling of Virus Inactivation by UV

UV₂₅₄ disinfection strategies are commonly applied to inactivate pathogenic viruses in water, food, air, and on surfaces. There is a need for methods that rapidly predict the kinetics of virus inactivation by UV₂₅₄, particularly for emerging and difficult-to-culture viruses. We conducted a systematic literature review of inactivation rate constants for a wide range of viruses. Using these data and virus characteristics, we developed and evaluated linear and nonlinear models for predicting inactivation rate constants. Multiple linear regressions performed best for predicting the inactivation kinetics of (+) ssRNA and dsDNA viruses, with cross-validated root mean squared relative prediction errors similar to those associated with experimental rate constants. We tested the models by predicting and measuring inactivation rate constants of a (+) ssRNA mouse coronavirus and a dsDNA marine bacteriophage; the predicted rate constants were within 7% and 71% of the experimental rate constants, respectively, indicating that the prediction was more accurate for the (+) ssRNA virus than the dsDNA virus. Finally, we applied our models to predict the UV₂₅₄ rate constants of several viruses for which high-quality UV₂₅₄ inactivation data are not available. Our models will be valuable for predicting inactivation kinetics of emerging or difficult-to-culture viruses.

Impact of Thrombocytopenia on Postoperative Bleeding Incidence in Patients Receiving Aspirin Following Coronary Artery Bypass Grafting

BACKGROUND

Early postoperative aspirin following coronary artery bypass graft (CABG) surgery has been shown to maintain bypass graft patency, reduce mortality, and prevent adverse cardiovascular events. Despite this known benefit, aspirin may be delayed due to thrombocytopenia and perceived higher bleeding risk. The purpose of this study was to assess the impact of postoperative platelet count on bleeding in patients receiving aspirin after CABG.

METHODS

A retrospective analysis included all patients who underwent CABG surgery at our institution from April 2014 to June 2018 and received aspirin within 24 hours. The primary outcome was International Society on Thrombosis and Hemostasis (ISTH) major bleeding within 7 days (or up to discharge) following CABG surgery compared between patients with and without postoperative thrombocytopenia.

RESULTS

This study included 280 patients. Major bleeding occurred in 24.6% of the population, with no difference when stratified by the presence or absence of postoperative thrombocytopenia (27.3% versus 23.8%, p = 0.571). There was no significant difference in hemoglobin fall (13.6% versus 14%, p = 0.948), transfusion requirement (6.1% versus 4.2%, p = 0.531), or critical site bleeding (12.1% versus 7.9%, p = 0.298).

CONCLUSION

In this single-center analysis of patients who received aspirin within 24 hours of CABG, postoperative thrombocytopenia was not associated with an increase in bleeding.

Genomic Characterization and Curation of UCEs Improves Species Tree Reconstruction

Ultraconserved genomic elements (UCEs) are generally treated as independent loci in phylogenetic analyses. The identification pipeline for UCE probes does not require prior knowledge of genetic identity, only selecting loci that are highly conserved, single copy, without repeats, and of a particular length. Here, we characterized UCEs from 11 phylogenomic studies across the animal tree of life, from birds to marine invertebrates. We found that within vertebrate lineages, UCEs are mostly intronic and intergenic, while in invertebrates, the majority are in exons. We then curated four different sets of UCE markers by genomic category from five different studies including: birds, mammals, fish, Hymenoptera (ants, wasps, and bees), and Coleoptera (beetles). Of genes captured by UCEs, we find that many are represented by two or more UCEs, corresponding to nonoverlapping segments of a single gene. We considered these UCEs to be nonindependent, merged all UCEs that belonged to a particular gene, constructed gene and species trees, and then evaluated the subsequent effect of merging cogenic UCEs on gene and species tree reconstruction. Average bootstrap support for merged UCE gene trees was significantly improved across all data sets apparently driven by the increase in loci length. Additionally, we conducted simulations and found that gene trees generated from merged UCEs were more accurate than those generated by unmerged UCEs. As loci length improves gene tree accuracy, this modest degree of UCE characterization and curation impacts downstream analyses and demonstrates the advantages of incorporating basic genomic characterizations into phylogenomic analyses. [Anchored hybrid enrichment; ants; ASTRAL; bait capture; carangimorph; Coleoptera; conserved nonexonic elements; exon capture; gene tree; Hymenoptera; mammal; phylogenomic markers; songbird; species tree; ultraconserved elements; weevils.]

An Annotated Chromosome-Level Reference Genome of the Red-Eared Slider Turtle (Trachemys scripta elegans)

Among vertebrates, turtles have many unique characteristics providing biologists with opportunities to study novel evolutionary innovations and processes. We present here a high-quality, partially phased, and chromosome-level Red-Eared Slider (Trachemys scripta elegans, TSE) genome as a reference for future research on turtle and tetrapod evolution. This TSE assembly is 2.269 Gb in length, has one of the highest scaffold N50 and N90 values of any published turtle genome to date (N50 = 129.68 Mb and N90 = 19 Mb), and has a total of 28,415 annotated genes. We introduce synteny analyses using BUSCO single-copy orthologs, which reveal two chromosome fusion events accounting for differences in chromosome counts between emydids and other cryptodire turtles and reveal many fission/fusion events for birds, crocodiles, and snakes relative to TSE. This annotated chromosome-level genome will provide an important reference genome for future studies on turtle, vertebrate, and chromosome evolution.

Incidence of and Risk Factors for Hepatic Encephalopathy in a Population-Based Cohort of Americans With Cirrhosis

Hepatic encephalopathy (HE) is a devastating complication of cirrhosis. Data are limited regarding the incidence of and risk factors for HE among contemporary patients in the context of the shifting epidemiology of cirrhosis. We examined a 20% random sample of U.S. Medicare enrollees with cirrhosis and Part D prescription coverage from 2008 to 2014. We modelled incident HE using demographic, clinical, and pharmacologic data. Risk factors for HE were evaluated, including demographics/socioeconomics, cirrhosis etiology, severity of liver disease, and pharmacotherapy, along with gastroenterology consultation, as time-varying covariates. Among 166,192 Medicare enrollees with cirrhosis followed for 5.25 (interquartile range [IQR], 2.00-7.00) years, the overall incidence of HE was 11.6 per 100 patient-years. The cohort's median age was 65 years (IQR, 57-72), 31% had alcohol-related cirrhosis, and 49% had likely nonalcoholic fatty liver disease cirrhosis. The two strongest associations with HE were alcohol-related cirrhosis (adjusted hazard ratio [AHR], 1.44; 95% confidence interval [CI], 1.40, 1.47, relative to nonalcoholic nonviral cirrhosis) and the presence of portal hypertension (AHR, 3.42; 95% CI, 3.34, 3.50). Adjusting for confounders, benzodiazepines (AHR, 1.24; 95% CI, 1.21, 1.27), gamma aminobutyric acid (GABA)ergics (AHR, 1.17; 95% CI, 1.14, 1.21), opioids (AHR, 1.24; 95% CI, 1.21, 1.27), and proton pump inhibitors (PPIs) (AHR, 1.41; 95% CI, 1.38, 1.45) were all associated with incident HE. Only benzodiazepines, however, were associated with the risk of hospitalization with HE (incidence-rate ratio, 1.23; 95% CI, 1.20, 1.26). Conclusion: Novel data regarding the risk of HE for contemporary patients with cirrhosis are provided. The incidence of HE in an older population of Americans with cirrhosis is high, particularly among those with alcohol-related cirrhosis and portal hypertension. Several medication classes, namely PPIs, opiates, GABAergics, and benzodiazepines, represent potentially modifiable risk factors for HE.

Nanopore sequencing of long ribosomal DNA amplicons enables portable and simple biodiversity assessments with high phylogenetic resolution across broad taxonomic scale

BACKGROUND

In light of the current biodiversity crisis, DNA barcoding is developing into an essential tool to quantify state shifts in global ecosystems. Current barcoding protocols often rely on short amplicon sequences, which yield accurate identification of biological entities in a community but provide limited phylogenetic resolution across broad taxonomic scales. However, the phylogenetic structure of communities is an essential component of biodiversity. Consequently, a barcoding approach is required that unites robust taxonomic assignment power and high phylogenetic utility. A possible solution is offered by sequencing long ribosomal DNA (rDNA) amplicons on the MinION platform (Oxford Nanopore Technologies).

FINDINGS

Using a dataset of various animal and plant species, with a focus on arthropods, we assemble a pipeline for long rDNA barcode analysis and introduce a new software (MiniBar) to demultiplex dual indexed Nanopore reads. We find excellent phylogenetic and taxonomic resolution offered by long rDNA sequences across broad taxonomic scales. We highlight the simplicity of our approach by field barcoding with a miniaturized, mobile laboratory in a remote rainforest. We also test the utility of long rDNA amplicons for analysis of community diversity through metabarcoding and find that they recover highly skewed diversity estimates.

CONCLUSIONS

Sequencing dual indexed, long rDNA amplicons on the MinION platform is a straightforward, cost-effective, portable, and universal approach for eukaryote DNA barcoding. Although bulk community analyses using long-amplicon approaches may introduce biases, the long rDNA amplicons approach signifies a powerful tool for enabling the accurate recovery of taxonomic and phylogenetic diversity across biological communities.

Complete mitochondrial genome sequences of the northern spotted owl (Strix occidentalis caurina) and the barred owl (Strix varia; Aves: Strigiformes: Strigidae) confirm the presence of a duplicated control region

We report here the successful assembly of the complete mitochondrial genomes of the northern spotted owl (Strix occidentalis caurina) and the barred owl (S. varia). We utilized sequence data from two sequencing methodologies, Illumina paired-end sequence data with insert lengths ranging from approximately 250 nucleotides (nt) to 9,600 nt and read lengths from 100–375 nt and Sanger-derived sequences. We employed multiple assemblers and alignment methods to generate the final assemblies. The circular genomes of S. o. caurina and S. varia are comprised of 19,948 nt and 18,975 nt, respectively. Both code for two rRNAs, twenty-two tRNAs, and thirteen polypeptides. They both have duplicated control region sequences with complex repeat structures. We were not able to assemble the control regions solely using Illumina paired-end sequence data. By fully spanning the control regions, Sanger-derived sequences enabled accurate and complete assembly of these mitochondrial genomes. These are the first complete mitochondrial genome sequences of owls (Aves: Strigiformes) possessing duplicated control regions. We searched the nuclear genome of S. o. caurina for copies of mitochondrial genes and found at least nine separate stretches of nuclear copies of gene sequences originating in the mitochondrial genome (Numts). The Numts ranged from 226–19,522 nt in length and included copies of all mitochondrial genes except tRNA^Pro, ND6, and tRNA^Glu. Strix occidentalis caurina and S. varia exhibited an average of 10.74% (8.68% uncorrected p-distance) divergence across the non-tRNA mitochondrial genes.

Northern Spotted Owl (Strix occidentalis caurina) Genome: Divergence with the Barred Owl (Strix varia) and Characterization of Light-Associated Genes

We report here the assembly of a northern spotted owl (Strix occidentalis caurina) genome. We generated Illumina paired-end sequence data at 90× coverage using nine libraries with insert lengths ranging from ∼250 to 9,600 nt and read lengths from 100 to 375 nt. The genome assembly is comprised of 8,108 scaffolds totaling 1.26 × 109 nt in length with an N50 length of 3.98 × 106 nt. We calculated the genome-wide fixation index (FST) of S. o. caurina with the closely related barred owl (Strix varia) as 0.819. We examined 19 genes that encode proteins with light-dependent functions in our genome assembly as well as in that of the barn owl (Tyto alba). We present genomic evidence for loss of three of these in S. o. caurina and four in T. alba. We suggest that most light-associated gene functions have been maintained in owls and their loss has not proceeded to the same extent as in other dim-light-adapted vertebrates.

Dementia caused by dural arteriovenous fistulas reversed following endovascular therapy

We describe two patients who presented with dementia as the primary neurological manifestation of their dural arteriovenous fistula (dAVF). Although dementia is not the most common presentation for a dAVF, these cases show that obliterating the fistula can eliminate this dreadful manifestation. This awareness may facilitate the diagnosis of dementia in cases caused by dAVF and allow for a minimally invasive treatment that restores cognitive function back to baseline.

Thyroid function in idiopathic oedema

BACKGROUND

The role of abnormal thyroid function in the aetiology of idiopathic oedema is unclear. Previous studies of small samples of patients have suggested a high prevalence of latent hypothyroidism and a possible deiodination defect in the conversion of T4 to T3 in this condition. There is a need to clarify the possible significance of abnormal thyroid function in a larger sample of idiopathic oedema patients.

OBJECTIVE

The study was undertaken to compare basal thyroid function in idiopathic oedema patients and in an age and sex-matched control group.

PATIENTS AND DESIGN

After excluding one idiopathic oedema patient and three control subjects with abnormal thyroid function, basal thyroid function was compared in 44 idiopathic oedema patients and in 44 age and sex-matched controls.

MEASUREMENTS

Basal thyroid function was assessed in patient and control groups by measuring serum T4, fT4, T3, fT3 and TSH by standard methods.

RESULTS

There were no significant differences in basal thyroid function between patient and control groups except for an elevated mean fT4 concentration in the idiopathic oedema group (P = 0.03). Exclusion of patients and controls taking oestrogen abolished this difference. T4:T3 ratios were similar in patient and control groups.

CONCLUSION

Abnormalities of basal thyroid function are uncommon in patients with idiopathic oedema and appear unrelated to the pathogenesis of this disorder. Similar T4:T3 ratios between patient and control groups exclude a deiodination defect in idiopathic oedema.

The role of diuretics in the aetiology of idiopathic oedema

The hypothesis that diuretic use and abuse and other purging behaviours cause idiopathic oedema was investigated in 102 patients. Of 91 symptomatic idiopathic oedema patients tested at referral, 16 (17.6%) had diuretic and four (4.4%) laxative in their urine. None had grossly disturbed serum urea and electrolytes. Examination of primary care records from 41 idiopathic oedema patients who denied current diuretic consumption, and denied or were uncertain about past consumption, showed that 20 had not been prescribed diuretics by their general practitioners at any time; a further 18 had not been prescribed diuretics for between seven months and 12 years before referral. The absence of evidence of plasma volume depletion (as judged by similar concentrations of mean serum urea, creatinine, total protein and albumin in patient and age-matched control groups) suggests that neither systematic diuretic and laxative use or abuse, nor episodic overeating and vomiting were responsible for symptoms of idiopathic oedema in our patients. Idiopathic oedema has a strong genetic basis, and correction of major and minor risk factors for this condition leads to substantial amelioration of symptoms in most cases.

Ranitidine suppresses aluminium absorption in man

1. Intragastric pH monitoring was performed before and after the single-blind administration of ranitidine or placebo (saline) in eight healthy subjects and four patients with end-stage renal disease who were on regular haemodialysis. 2. The subjects were studied on two occasions and were given aluminum hydroxide (1185 mg) orally 90 min after the administration of ranitidine or saline. 3. Plasma aluminum concentrations and, in normal men, urinary excretion of aluminum were monitored before and after the oral aluminum load. 4. Intragastric pH increased significantly with ranitidine but not with placebo (P less than 0.001). Urinary aluminum excretion increased significantly after the administration of aluminum hydroxide during the placebo phase (P less than 0.001) but not during the ranitidine phase. Plasma aluminium concentrations were higher in the patients with renal failure than in the normal subjects (P less than 0.05), but were unchanged in both groups after the oral aluminium load. 5. This study shows that gastric pH is an important factor in the modulation of aluminum absorption in man, and indicates that reducing gastric acid secretion with ranitidine may reduce the toxicity of orally administered aluminium compounds.

Asian osteomalacia is determined by dietary factors when exposure to ultraviolet radiation is restricted: a risk factor model

Twenty-seven previously osteomalacic and 77 normal Asian women participated in a seven-day survey of dietary intake and daylight outdoor exposure. Individual levels of daylight outdoor exposure discriminated poorly between normal and osteomalacic women. The presence of osteomalacia was strongly related to varying degrees of vegetarianism. Lactovegetarianism (no meat, fish or egg consumption) was associated with significantly greater osteomalacic risk than ovolactovegetarianism (no meat or fish consumption). Unlike Asian rickets, high-extraction wheat cereal as chapatti was not a significant risk factor for osteomalacia in Asian women and dietary fibre was a less important risk factor than absent dietary meat, fish or egg. When exposure to ultraviolet radiation is limited, Asian osteomalacia (and Asian rickets) are determined by dietary factors.

Changes in the incidence of acute appendicitis in Glasgow Asian and white children between 1971 and 1985

Between 1971 and 1985 there was a significant rise in the annual hospital discharge rate for acute appendicitis in Glasgow Asian boys aged 10-19.9 years. A smaller and statistically insignificant rise occurred in Asian girls of 10-19.9 years; discharge rates for younger Asian boys and girls did not change significantly. In keeping with national trends, discharge rates for acute appendicitis in all Glasgow children fell significantly between 1971-85. The divergent trend in older Asian children may reflect dietary adaptation which is most marked in older Asian boys.

The importance of limited exposure to ultraviolet radiation and dietary factors in the aetiology of Asian rickets: a risk-factor model

Regional variation in the prevalence of Asian rickets was examined in Coventry, Bradford and Glasgow. Records of 152 weeks of daylight outdoor exposure were obtained from 104 Glasgow Asian children, 53 of whom had been treated for rickets. Records of seven-day weighed dietary intake were obtained from 84 Asian children, 43 of whom had been treated for rickets. There was a marked north-south gradient in the prevalence of Asian rickets. In all cases of severe rickets with deformity the child was vegetarian. Severe rickets was associated with lower intake of meat, higher intake of chapati and lower daylight outdoor exposure values than in normal children. Multivariate analysis employing a combination of these variables provided good separation between rachitic and normal groups. A risk-factor model is proposed which suggests that regional variation in the prevalence of rickets among Asian communities in Britain is mainly determined by the effects of latitude and the nature of the urban environment on available ultraviolet radiation. Where UV radiation is restricted, individual propensity to rickets within a given Asian community is mainly determined by dietary factors.

Prevention of rickets in Asian children: assessment of the Glasgow campaign

In March 1979 the Greater Glasgow Health Board launched a campaign to reduce the high prevalence of rickets in Asian children in the city. A precampaign survey had shown that voluntary low dose vitamin D supplementation would reduce the prevalence of rickets in Asian children. A survey carried out two and three years after the launch of the official campaign also showed a reduction in the prevalence of rickets in children taking low dose supplements equivalent to about 2.5 micrograms (100 IU) vitamin D daily. There was a considerable reduction in the total prevalence of rickets in this survey compared with the precampaign survey. Hospital discharges of Asian children with rickets declined rapidly after the start of the campaign.

The evaluation of new services: possibilities for preventing congenital toxoplasmosis

We examine the resource implications of two potential health services aimed at preventing congenital toxoplasmosis: a screening service involving serological surveillance for toxoplasma infection in pregnant women and its prophylactic treatment; and a health education campaign to help pregnant women avoid acquiring toxoplasma infection, through advice about special precautions regarding hygiene. Measuring the costs and benefits of prevention is complicated by uncertainty of the incidence of congenital toxoplasmosis in the United Kingdom, the extent of its harmful manifestations--mental and visual handicap--and the effectiveness of preventive measures. Hence an important aspect of this study is that it exemplifies the use of 'sensitivity analysis' as an aid to evaluation in the absence of hard data. We find that a screening service would seem unlikely to save resources, but that a health education campaign would seem much more likely to do so and further assessment of its potential effectiveness would be valuable.

Co-ordinating prevention

A major reason why the balance between pronouncements on prevention and action is tipped so much towards the former is that, in most countries, responsibility for prevention is fragmented and vaguely defined. If an effective and efficient national prevention policy is to come about, then it is important that overall responsibility be placed in the hands of a single agency, and for that agency to recognise that priorities in prevention must be a function of costs as well as benefits. The first task of such an agency will be to sort out the fundamental objectives of public policy by clarifying what is meant by prevention and specifying the rationale for government intervention and hence the sorts of prevention which should be the responsibility of the public sector. Given this, national expenditure on prevention from any source which contributes to government prevention strategy can be identified and expressed in the form of a programme budget showing the proportions of total prevention expenditure going to each of the defined programme areas (environment, occupational health and safety, screening, health promotion, etc.). This framework gives a broad overview of the existing situation and by forcing consideration of benefit valuation in any decision to alter the balance of expenditure between programmes, ought to lead to a more rational prevention strategy than would result from a focus on individual programmes in isolation. Moreover, through an emphasis on costs and benefits, the overseers of prevention policy will be better placed to consider the relative efficiency of existing policies--since all share the common objective of reducing future morbidity and mortality. Finally, consideration will also need to be given to issues of equity. The approach described, illustrated by the case of the United Kingdom, will, if adopted, increase the likelihood that a rational and sensible national prevention policy will emerge.

Controlled hypotensive anesthesia to reduce blood loss in radical cystectomy for bladder cancer

Controlled intraoperative hypotension has been reported to reduce blood loss in major cancer operations. We did a retrospective evaluation on the effects of induced controlled hypotensive anesthesia using enflurane or trimethaphan compared to standard normotensive anesthesia in 37 consecutive patients who were undergoing single stage radical cystectomy with pelvic lymphadenectomy and bilateral ureteroileal cutaneous urinary diversion. Group 1 contained 16 patients who received induced hypotensive anesthesia and group 2 contained 21 patients who received normotensive anesthesia. Average age, pathological stage, and hematocrit values preoperatively and 5 days postoperatively were not significantly different. The average blood loss in group 1 was 821 plus or minus 78 cc and in group 2 it was 1,740 plus or minus 132 cc, a difference of 919 cc (p less than 0.001). Concomitantly, total blood replacement was significantly different. The hypotensive group required an average of 1.38 plus or minus 0.25 units or 700 plus or minus 100 cc and the normotensive group averaged 3.25 plus or minus 0.45 units or 1,600 plus or minus 225 cc (p less than 0.05). In addition, only 69 per cent of the hypotensive group required blood replacement compared to 90 per cent of the normotensive group. Our data demonstrate that controlled hypotensive anesthesia markedly reduces blood loss for radical bladder cancer surgery.

Smoking cessation in patients with cardiopulmonary disease: an initial study

Thirty-five smokers, all with current, long-standing, cardiovascular or pulmonary disease, were randomly assigned to either health motivation treatment, or to aversive smoking. The former included self-management skills, a film model, verbal commitment, and discussion of the costs and benefits of smoking and abstinence. The latter included normally paced (every 30 sec.) aversive smoking, relaxation training, role playing high risk situations, and discussion of maladaptive thought patterns. Strong differences between the conditions in abstinence rate and reduction from baseline did not emerge; however, the data generally favored the health motivation condition both in attrition rates and in outcome immediately posttreatment and at six month follow-up. Negative mood states were found to be related to minimal reduction in smoking; and consistent mood dysphoria at pre and posttreatment predicted relapse at three month follow-up.

Measuring the benefits of screening for open neural tube defects

Evaluation of the costs and benefits of public sector programmes is necessary to plan the optimum uses for society's resources. Here the benefits of screening for open neural tube defects are examined, and the most appropriate methodological approach to their valuation is discussed in the context of the possible provision by the National Health Service of a routine prenatal screening programme. It is argued that, in measuring the benefits of screening, previous evaluations have adopted an approach that is rather unsatisfactory from the standpoint of economic methodology. An attempt is therefore made here to show the effect that adopting a more appropriate approach would have on the estimated value of the benefit of routine screening. The effect is found to be a substantial increase in its estimated value.

An economic appraisal of the benefits of screening for open spina bifida

Appraisal of the costs and benefits of public sector programmes is an essential part of planning the optimal allocation of society's resources. This paper reports a study of the potential benefits to be derived if the UK National Health Services (NHS) were to introduce a mass-screening programme for the prenatal detection of fetuses affected by open spina bifida. These benefits are compared with the costs of a screening programme as estimated in the Report [1] by the Working Group on Screening for Neural Tube Defects of the Department of Health and Social Security (DHSS), A satisfactory screening test for open spina bifida has been developed in recent years, but routine prenatal screening has not yet become generally available. The paper therefore considers first the inferences that may be drawn about the efficiency and desirability of implementing a national screening programme from comparison of its costs and benefits. A brief description of screening and its likely impact is followed by a discussion of previous attempts at measuring the benefits of a screening programme and it is argued that these evaluations have adopted an approach which is rather unsatisfactory from the standpoint of economic methodology. A more appropriate conceptual approach to measuring the benefits of a screening programme is outlined and, after discussing the resolution of the theoretical and practical problems encountered in applying it, estimates of the benefits are calculated. The findings are compared first with those of previous studies which are shown to have under-estimated the benefits and secondly with the costs of a screening programme which almost certainly are lower than the benefits. It is therefore concluded that a screening programme would constitute an efficient use of NHS resources. Details of the data and their sources are appended.

Vowel height and the perception of consonant nasality

By means of an articulatory synthesizer, the perception of the oral-nasal distinction in consonants was explored experimentally. This distinction was chosen because it is achieved by a very simple articulatory maneuver and because it is phonologically relevant in virtually every language. Lowering the velum in equal increments provided continua of CV syllables varying in size of velopharyngeal port which were divided perceptually into /d/ and /n/ categories by American English listeners. To test the hypothesis that the coarticulation of these nasal consonants with lower (more open) vowels requires a larger area of velopharyngeal coupling to give a nasal consonant precept, three oral-nasal continua incorporating the vowels /i/, /delta/, and /alpha/, respectively, were presented for identification. The results were compared with those of A. S. House and K. N. Stevens [J. Speech Hear. Disord. 21, 218-232 (1956)] and A. S. House [J. Speech Hear. Disord. 22, 190-204 (1957)] obtained with steady-state vowels and consonantal murmurs and with those of M. H. L. Hecker [J. Acoust. Soc. Am. 34, 179-188 (1962)]. Three conclusions emerged. First, the relationship between vowel height and the amount of velopharyngeal coupling needed for a nasal precept occurs in conditions where subjects are required to make linguistically relevant judgments. Second, the relationship can arise in conditions where vocalic coarticulation is present. Third, the relationship is not confined to vowels but can also be observed in the case of dynamically articulated consonants. One of the continua was also used for discrimination experiments, which yielded the classical pattern of high discriminability at the category boundary.