Transcriptomic changes behind Sparus aurata hepatic response to different aquaculture challenges: An RNA-seq study and multiomics integration

Gilthead seabream (Sparus aurata) is an important species in Mediterranean aquaculture. Rapid intensification of its production and sub-optimal husbandry practices can cause stress, impairing overall fish performance and raising issues related to sustainability, animal welfare, and food safety. The advent of next-generation sequencing technologies has greatly revolutionized the study of fish stress biology, allowing a deeper understanding of the molecular stress responses. Here, we characterized for the first time, using RNA-seq, the different hepatic transcriptome responses of gilthead seabream to common aquaculture challenges, namely overcrowding, net handling, and hypoxia, further integrating them with the liver proteome and metabolome responses. After reference-guided transcriptome assembly, annotation, and differential gene expression analysis, 7, 343, and 654 genes were differentially expressed (adjusted p-value < 0.01, log2|fold-change| >1) in the fish from the overcrowding, net handling, and hypoxia challenged groups, respectively. Gene set enrichment analysis (FDR < 0.05) suggested a scenario of challenge-specific responses, that is, net handling induced ribosomal assembly stress, whereas hypoxia induced DNA replication stress in gilthead seabream hepatocytes, consistent with proteomics and metabolomics' results. However, both responses converged upon the downregulation of insulin growth factor signalling and induction of endoplasmic reticulum stress. These results demonstrate the high phenotypic plasticity of this species and its differential responses to distinct challenging environments at the transcriptomic level. Furthermore, it provides significant resources for characterizing and identifying potentially novel genes that are important for gilthead seabream resilience and aquaculture production efficiency with regard to fish welfare.

Fostering Flexibility: How Medicare Advantage Potentially Accelerated Telehealth Benefits

In 2018, the US Congress enacted a policy permitting Medicare Advantage (MA) plans to cover telehealth services in a beneficiary's home and through audio-only means as part of the basic benefit package of services, where prior to the policy change such benefits were only allowed to be covered as a supplemental benefit. MA plans were afforded 2 years of lead time for strategizing, negotiating, and capital investment prior to the start date (January 1, 2020) of the new coverage option. Our data analysis found basic benefit telehealth was offered by plans comprising 71% of enrollment in 2020 and increased to 95% in 2021. At the same time, remote access telehealth was offered as a supplemental benefit for 69% of enrollees in 2020, a decrease of 23% compared to 2019. These efforts by MA plans may have enabled traditional Medicare (TM) to leverage an existing telehealth infrastructure as a solution to the access issues created by public health policies requiring sheltering in place and social distancing during the COVID-19 pandemic. The success of this MA policy prompts consideration of additional flexibility beyond the standard basic benefit package, and whether such benefits reduce costs while improving access and/or outcomes in the context of a managed care environment like MA. Subject to oversight, such flexibility could potentially improve value in MA, and facilitate future changes in TM, as appropriate.

Physician responses to Medicare reimbursement rates

This paper investigates how office-based physicians respond to Medicare reimbursement changes. Using variation from an Affordable Care Act policy that increased reimbursements for office-based care in four states, we use a triple difference analysis, comparing physicians with higher and lower reimbursement changes in treated states to similar physicians in untreated states. We find two mechanisms through which physicians respond. First, the reimbursement change affected integration-physicians with larger increases in office-based reimbursement were less likely to vertically integrate with hospitals and more likely to continue providing office-based care than physicians with smaller reimbursement increases. Second, we find some evidence that physicians who continued practicing in an office setting increased the volume of services provided.

Sponge-derived fatty acids inhibit biofilm formation of MRSA and MSSA by down-regulating biofilm-related genes specific to each pathogen

AIM

A promising approach for the development of next generation antimicrobials is to shift their target from causing bacterial death to inhibiting virulence. Marine sponges are an excellent potential source of bioactive anti-virulence molecules (AVM). We screened fractions prepared from 26 samples of Irish coastal sponges for anti-biofilm activity against clinically relevant pathogens.

METHODS AND RESULTS

Fifteen fractions from eight sponge species inhibited biofilm of methicillin-susceptible Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA) and/or Listeria monocytogenes without causing growth inhibition. GC-MS analyses of Mycale contarenii fractions revealed the presence of myristic acid and oleic acid. These fatty acids repressed transcription of the fibronectin-binding protein fnbA and fnbB genes and the polysaccharide intercellular adhesin icaADBC operon, required for MRSA and MSSA biofilm formation, respectively.

CONCLUSIONS

This study illustrates the potential of AVM from Irish coastal sponges to specifically target bacterial virulence phenotypes, in this case repression of biofilm formation via decreased transcription of biofilm-associated genes in MSSA and MRSA.

The Two-Margin Problem in Insurance Markets

Insurance markets often feature consumer sorting along both an extensive margin (whether to buy) and an intensive margin (which plan to buy). We present a new graphical theoretical framework that extends a workhorse model to incorporate both selection margins simultaneously. A key insight from our framework is that policies aimed at addressing one margin of selection often involve an economically meaningful trade-off on the other margin in terms of prices, enrollment, and welfare. Using data from Massachusetts, we illustrate these trade-offs in an empirical sufficient statistics approach that is tightly linked to the graphical framework we develop.

Prokaryotic symbiont communities in three ascidian species introduced in both Ireland and New Zealand

Ascidians or sea squirts are among the marine taxa with the most introduced species worldwide. These animals have a suite of biological characteristics that contribute to their successful establishment, including long reproductive seasons, rapid growth rates, and resistance to pollution. Here, we sequenced a fragment of the 16S ribosomal RNA gene to characterize symbiont diversity and host-specificity in the solitary species Syela clava and Ascidiella aspersa, and the colonial species Didemnum vexillum. Samples were collected from introduced populations in several marinas and mussel facilities around Ireland, and a marina in New Zealand. Two additional colonial species Botrylloides violaceus and Didemnum sp. were collected in Ireland, and ambient seawater was sampled from both countries for comparison. Data revealed a strong effect of host species and location on prokaryote symbiont composition, consistent with recent ascidian microbiome literature. However, a location effect did not manifest in alpha diversity metrics (e.g., the same ascidian species at different locations exhibited similar diversity) but was evident in beta diversity metrics (greater intra-specific differences across locations than within locations). Location effects were stronger than species effects only for the solitary species (i.e., A. aspersa from New Zealand was more similar to S. clava from New Zealand than to A. aspersa from Ireland). D. vexillum and A. aspersa hosted a high abundance of prokaryotic symbionts that were previously found in other ascidian species, while S. clava symbiotic community was more closely related to bacteria common in the marine environment. Further studies should aim to unravel host-microbe coevolutionary patterns and the microbial role in facilitating host establishment in different habitats.

Dynamic gill and mucus microbiomes during a gill disease episode in farmed Atlantic salmon

Amoebic gill disease (AGD) and complex gill disease (CGD) are recurrent gill disorders in Atlantic salmon, resulting in significant aquaculture losses. The role of gill microbiomes in gill disease development is unclear. We undertook a longitudinal study to characterise the gill tissue and gill mucus microbiomes of farmed Atlantic salmon before, and during, a gill disease episode. Using a newly optimised DNA extraction protocol, we sequenced rRNA genes from microbiomes of gill samples taken from 105 individual salmon on a farm, over a summer season. The AGD aetiological agent, Neoparamoeba perurans, was PCR-quantified targeting 18S rRNA genes. Similar analyses were carried out on mucus samples. Mucus scrapings were suitable, non-lethal substitutes for characterisation of the gill prokaryotic community in this study. Gill tissue and gill mucus microbiomes changed during the campaign, correlating with N. perurans concentrations. Time explained 35% of the gill tissue and gill mucus microbiome variance, while N. perurans concentrations explained 5%. Genera including Dyadobacter, Shewanella and Pedobacter were maximally abundant in gill and mucus samples at the timepoint prior to the the detection of gill disorder signs, at T3. Shewanella was significantly more abundant before than during the gill disease episode, and we suggest this genus could be considered in future studies addressing relationships between gill disease and the gill microbiome.

Association of Medicaid Expansion With Medicaid Enrollment and Health Care Use Among Older Adults With Low Income and Chronic Condition Limitations

Question

Was the expansion of Medicaid to working-age adults under the Patient Protection and Affordable Care Act (ACA) associated with changes in Medicaid enrollment and health care use among older adults with low income and chronic condition limitations?

Findings

In this cross-sectional study of 7153 US adults 65 years or older with low income, ACA Medicaid expansion was associated with significant increases in the likelihood of Medicaid enrollment and outpatient health care use among those with chronic condition limitations. No associations were found between ACA Medicaid expansion and Medicaid enrollment and health care use among those without such limitations.

Meaning

In this study, expansion of Medicaid to working-age adults was associated with increased Medicaid enrollment and outpatient health care use among older adults with low income and chronic condition limitations who were enrolled in Medicare.

Importance

Medicaid is an important source of supplemental coverage for older Medicare beneficiaries with low income. Research has shown that Medicaid expansion under the Patient Protection and Affordable Care Act (ACA) was associated with increased Medicaid coverage for previously eligible older adults with low income, but there has been little research on whether their health care use increased or whether such changes differed by beneficiaries’ health status.

Objective

To assess whether the ACA Medicaid expansion to working-age adults was associated with increased Medicaid enrollment and health care use among older adults with low income with and without chronic condition limitations.

Design, Setting, and Participants

This cross-sectional study used data from the National Health Interview Survey from 2010 to 2017 for adults 65 years or older with low income (≤100% of the federal poverty level). Data were analyzed from November 2020 to March 2022.

Exposure

Residence in a state with Medicaid expansion for working-age adults.

Main Outcomes and Measures

The main outcomes were Medicaid coverage and health care use, measured by physician office visits and inpatient hospital care. Survey weights were used in calculating descriptive statistics and regression estimates. In multivariate analysis, difference-in-differences models were used to compare changes in outcomes over time between respondents in Medicaid expansion states and respondents in nonexpansion states.

Results

Of 21 859 adults included in the study, 7153 had chronic condition limitations (4983 [70.1%] female; mean [SD] age, 76.0 [0.1] years) and 14 706 did not have chronic condition limitations (9609 [66.3%] female; mean [SD] age, 74.85 [0.08] years). Of those with chronic condition limitations, 2707 (36.7%) were enrolled in Medicaid, 2816 (39.4%) had an office visit in the past 2 weeks, and 2152 (30.7%) used inpatient hospital care in the past year. Medicaid expansion was associated with differential increases in the likelihood of having Medicaid (4.92 percentage points; 95% CI, 0.25-9.60 percentage points; P = .04) and having an office visit in the past 2 weeks (5.31 percentage points; 95% CI, 0.10-10.51 percentage points; P = .046) compared with nonexpansion. There were no differential changes between expansion and nonexpansion states in receipt of inpatient hospital care (−0.62 percentage points; 95% CI, −5.39 to 4.14 percentage points; P = .79). Among adults without chronic condition limitations, 3159 (19.8%) were enrolled in Medicaid, and no differential changes between expansion and nonexpansion states in Medicaid enrollment (−0.24 percentage points; 95% CI, −3.06 to 2.57 percentage points; P = .86) or health care use were found.

Conclusions and Relevance

In this cross-sectional study, ACA Medicaid expansion for working-age adults was associated with increased Medicaid enrollment and outpatient health care use among older adults with low income and chronic condition limitations who were dually eligible for Medicare and Medicaid.

Immigrant Essential Workers Likely Avoided Medicaid And SNAP Because Of A Change To The Public Charge Rule

During the COVID-19 pandemic in the US, essential workers have provided health care, food, and other necessities, often incurring considerable risk. At the pandemic's start, the federal government was in the process of tightening the "public charge" rule by adding nutrition and health benefits to the cash benefits that, if drawn, could subject immigrants to sanctions (for example, green card denial). Census Bureau data indicate that immigrants accounted for 13.6 percent of the population but 17.8 percent of essential workers in 2019. About 20.0 million immigrants held essential jobs, and more than one-third of these immigrants resided in US states bordering Mexico. Nationwide, 12.3 million essential workers and 18.9 million of their household members were at risk because of the new sanctions. The rule change (which was subsequently revoked) likely caused 2.1 million essential workers and household members to forgo Medicaid and 1.3 million to forgo Supplemental Nutrition Assistance Program assistance on the eve of the pandemic, highlighting the potential of immigration policy changes to exacerbate health risks.

New records of Demospongiae (Porifera) from Reserva Marina El Pelado (Santa Elena, Ecuador), with description of Tedania (Tedania) ecuadoriensis sp. nov

The first taxonomic descriptions of the sponge diversity at El Pelado Marine Protected Area in the province of Santa Elena, Ecuador is reported. Tedania (Tedania) ecuadoriensis Jaramillo & Hajdu, sp. nov. is described from its shallow waters. In addition, Callyspongia (Callyspongia) aff. californica (sensuCruz-Barraza and Carballo 2008; non sensuDickinson 1945) and Cliona aff. euryphylle are reported for the first time. The former species is likely distributed over 4,000 km along the Tropical Eastern Pacific, whereas the latter might be an example of a trans-isthmian lineage. An amended diagnosis for Callyspongia (Callyspongia) and an updated identification key for the subgenera of Callyspongia are provided.

Economic Vulnerability of Households With Essential Workers

This study uses 2018 national survey data to characterize the proportion of essential workers in the US overall and living in economically vulnerable households, defined as income <$40 000 or at least 1 member uninsured or older than age 65.

Integrating morphological and molecular taxonomy with the revised concept of Stelligeridae (Porifera: Demospongiae)

This study reinforces and extends the findings of previous molecular studies showing that there is a close relationship between species assigned to the sponge genera Halicnemia, Higginsia, Paratimea and Stelligera and that the family Heteroxyidae is polyphyletic. The present study has led to the description of one new species of Halicnemia and six new species of Paratimea, the resurrection of Halicnemia gallica and a better understanding of the characters uniting Stelligeridae. A new species of Heteroxya is also described. We demonstrate that many of the taxa assigned to Heteroxyidae are more closely related to other families, and we propose several changes to the classification of Heteroscleromorpha. Desmoxyidae is resurrected from synonymy and transferred to Poecilosclerida; Higginsia anfractuosa is transferred to Hymedesmiidae, and a new genus, Hooperia, is erected for its reception; Higginsia durissima is returned to Bubaris (Bubaridae); Higginsia fragilis is transferred to Spanioplon (Hymedesmiidae); Hemiasterella camelus is transferred to Paratimea; and Raspailia (Parasyringella) australiensis and Ceratopsion axiferum are transferred to Adreus (Hemiasterellidae).

Progressive programmed cell death inwards across the anther wall in male sterile flowers of the gynodioecious plant Plantago lanceolata

A cell death signal is perceived and responded to by epidermal cells first before being conveyed inwards across the anther wall in male sterile Plantago lanceolata flowers. In gynodioecious plants, floral phenotype is determined by an interplay between cytoplasmic male sterility (CMS)-promoting factors and fertility-restoring genes segregating in the nuclear background. Plantago lanceolata exhibits at least four different sterilizing cytoplasms. MS1, a "brown-anther" male sterile phenotype, segregates with a CMSI cytoplasm and a non-restoring nuclear background in P. lanceolata populations. The aim of this study was to investigate the cytology of early anther development in segregating hermaphrodite and male sterile flowers sharing the same CMSI cytoplasm, and to determine if the sterility phenotype correlates with any changes to the normal pattern of programmed cell death (PCD) that occurs during anther development. Cytology shows cellular abnormalities in all four anther wall layers (epidermis, endothecium, middle layer and tapetum), the persistence and enlargement of middle layer and tapetal cells, and the failure of microspore mother cells to complete meiosis in male sterile anthers. In these anthers, apoptotic-PCD occurs earlier than in fertile anthers and is detected in all four cell layers of the anther wall before the middle layer and tapetal cells become enlarged. PCD is separated spatially and temporally within the anther wall, occurring first in epidermal cells before extending radially to cells in the inner anther wall layers. This is the first evidence of a cell death signal being perceived and responded to by epidermal cells first before being conveyed inwards across the anther wall in male sterile plants.

Assessing the Zoantharian Diversity of the Tropical Eastern Pacific through an Integrative Approach

Zoantharians represent a group of marine invertebrates widely distributed from shallow waters to the deep sea. Despite a high diversity and abundance in the rocky reefs of the Pacific Ocean, very few studies have been reported on the diversity of this group in the Tropical Eastern Pacific coasts. While molecular techniques recently clarified some taxonomic relationships within the order, the taxonomy of zoantharians is still highly challenging due to a lack of clear morphological characters and confusing use of different data in previous studies. Our first insight into the zoantharian diversity at El Pelado Marine Protected Area - Ecuador led to the identification of six species: Terrazoanthus patagonichus; Terrazoanthus sp.; Antipathozoanthus hickmani; Parazoanthus darwini; Zoanthus cf. pulchellus; and Zoanthus cf. sociatus. A metabolomic approach using UHPLC-HRMS was proven to be very efficient as a complementary tool in the systematics of these species and specialized metabolites of the ecdysteroid and alkaloid families were identified as key biomarkers for interspecific discrimination. These results show good promise for an application of this integrative approach to other zoantharians.

Sulfated steroid-amino acid conjugates from the Irish marine sponge Polymastia boletiformis

Antifungal bioactivity-guided fractionation of the organic extract of the sponge Polymastia boletiformis, collected from the west coast of Ireland, led to the isolation of two new sulfated steroid-amino acid conjugates (1 and 2). Extensive 1D and 2D NMR analyses in combination with quantum mechanical calculations of the electronic circular dichroism (ECD) spectra, optical rotation, and ¹³C chemical shifts were used to establish the chemical structures of 1 and 2. Both compounds exhibited moderate antifungal activity against Cladosporium cucumerinum, while compound 2 was also active against Candida albicans. Marine natural products containing steroidal and amino acid constituents are extremely rare in nature.

An update of recent evidence of the relationship between objective and self-report measures of the physical environment and physical activity behaviours

The physical environment has the potential to influence the physical behaviours of large numbers of people; hence creating supportive environments has the potential to increase physical activity (PA). During the last decade, there has been growing interest in how the physical environment shapes PA behaviour. This area of research is important given that levels of PA participation are declining globally. Literature was reviewed that examined the association between physical environmental attributes and PA behaviours. The environmental attributes were grouped into four categories based on a conceptual framework of environmental factors that might influence PA and included functionality, safety, aesthetics and destinations. Positive associations were found between both perceived and objectively measured environmental factors and PA behaviour. The availability, accessibility and convenience of destinations and facilities, as well as the general functionality of the neighbourhood (eg, the presence of sidewalks, traffic conditions) and aesthetics were positively associated with various levels of PA. The review highlights the need for future studies: to examine behaviour-specific environmental attributes, to collect objectively-measured environmental data and to include both objective and perceived environmental data in the same studies, and to adopt prospective study designs to allow causal relationships to be established.

Long-term results of low-dose intravenous ciclosporin for acute severe ulcerative colitis

BACKGROUND

Intravenous ciclosporin for acute, severe colitis is usually administered in a dose of 4 mg/kg/day, with concurrent intravenous steroids. This is associated with considerable morbidity. We have been using a low-dose regimen, most commonly without concurrent steroids, for seven years, and present the outcome.

METHODS

Records of all patients admitted for severe ulcerative colitis, treated by one physician over seven years, were reviewed.

RESULTS

Thirty-one patients received low-dose intravenous ciclosporin (2 mg/kg/day) for a median 8 days. Eleven early patients received concurrent intravenous corticosteroids. Three patients had hypertension requiring dose reduction, one elevated creatinine and one elevated liver enzymes (all transient), and four experienced infection (two arm cellulitis, one perianal abscess, one post-operative wound infection). Twenty-four patients (77%) avoided urgent colectomy, and were discharged on oral ciclosporin and azathioprine. After a median 18 months (range 3-77), 14 patients (45% of total) avoided colectomy, of whom eight had flares responding to medical therapy and two had persistent, mildly active disease.

CONCLUSIONS

Low-dose intravenous ciclosporin (2 mg/kg/day), usually used as a monotherapy and followed by azathioprine, achieves similar long-term efficacy to higher dose ciclosporin combined with steroids in severe acute ulcerative colitis. Morbidity appears to be low.

Tissue cytokine and chemokine expression in inflammatory bowel disease

OBJECTIVE AND DESIGN

This study aimed to determine if mucosal expression of the chemokines IL-8, RANTES and MCP-1 and the pro-inflammatory cytokines TNFalpha and IL-6 are elevated in patients with inflammatory bowel disease.

MATERIALS AND SUBJECTS

Intestinal mucosa samples were obtained at the time of surgical resection, n = 16 from each of the following groups: normal/control, CD and UC.

METHODS

An homogenate was prepared of each tissue sample and cytokines measured by ELISA.

RESULTS

IL-8 was significantly increased in both disease groups compared to controls Similarly, RANTES levels were also significantly increased. MCP-1 levels were increased in both disease groups, this increase was statistically significant in the UC group only. TNFalpha and IL-6 were significantly increased in the CD group only.

CONCLUSIONS

Chemokines, together with key cytokines that promote their release are elevated in mucosal tissues from patients with IBD. It is likely that these chemokines play an important role in the perpetuation of tissue destructive inflammatory processes.

Oral fluid collection by post for viral antibody testing

BACKGROUND

The objective of this study was to estimate the prevalence of hepatitis B virus exposure (HBV) in the population of the Republic of Ireland, by using oral fluid (saliva) collection by post for hepatitis B anti-core antibody (anti-HBc). This paper discusses the methodological approach used and the strategies that were adopted to improve response rates.

METHODS

The sampling frame used was the Register of Electors for Irish parliamentary elections. A multistage stratified cluster sample was taken, and a total of 962 households were selected nationally. A four-letter approach was employed for sample collection. Households received an initial letter outlining the purpose of the study. This was followed by a letter containing six swabs for oral fluid collection, along with easy-to-follow instructions. Non-respondents received two reminder letters, and were also telephoned where possible. A telephone helpline was provided. All testing was anonymous and unlinked.

RESULTS

The study achieved a good household response rate (60.4%), and more than 98% of the 1738 specimens received were suitable for testing. The prevalence of anti-HBc in the Irish population was estimated to be 0.51%. The observed design effect was 1.29.

DISCUSSION

From a review of the literature, this is the first study where a representative sample of a national population was asked to self-collect oral fluid samples and return these by post for serological testing. The technique may have many future applications in epidemiological research.

In-vitro cyclosporin sensitivity of proliferating lymphocytes is predictive of in-vivo therapeutic response in ulcerative colitis

BACKGROUND

The efficacy of cyclosporin in the management of ulcerative colitis is recognized. Not all patients respond to this treatment. Existing clinical and laboratory parameters are of little use in identifying those most likely to respond.

AIMS

To determine whether in-vitro sensitivity to cyclosporin as measured by a lymphocyte proliferation assay is predictive of in-vivo response to therapy.

METHODS

The study comprised seven responders with ulcerative colitis, seven non-responders, and 14 healthy matched controls. A lymphocyte proliferation assay was carried out in the presence of a range of concentrations of cyclosporin and a dose-response curve constructed for each subject. The IC(50) value, the concentration of cyclosporin that resulted in 50% inhibition of proliferation, was calculated for each subject. IC(50) values for responders, non-responders and controls were compared using a Mann-Whitney test.

RESULTS

There was a wide range of values obtained for the study group as a whole. IC(50) values for non-responders were significantly higher than those of responders (P < 0.05).

CONCLUSIONS

There is a population-wide variation of in-vitro sensitivity to cyclosporin. This is reflected in in-vivo sensitivity as measured by clinical response to cyclosporin treatment. Future therapeutic strategies need to address this inherent variability of individual response to therapy.

Transjuglar liver biopsy: a review

Transjugular liver biopsy is advocated as the technique of choice for use in those with contraindications to standard transabdominal biopsy. This technique was introduced to our unit in 1995. We audited our experience in performing transjugular liver biopsies over a three year period. Eighty-eight biopsies were performed in seventy-eight patients. We identified no major procedure related complications, despite the presence of coagulopathy and thrombocytopenia in 85% and 47% of cases respectively. Biopsy provided histological diagnosis in 97.7% of cases. Availability of the technique allowed us to perform liver biopsy safely and quickly in patients with both acute and chronic liver problems in whom standard techniques were contraindicated. We conclude that transjugular liver biopsy is a safe and effective technique, invaluable in the investigation and management of patients in a liver diseases referral unit.

Prevalence of hepatitis B anti-core antibody in the Republic of Ireland

The aim of this study was to estimate the prevalence of hepatitis B exposure in the population of the Republic of Ireland, by measuring the prevalence of hepatitis B anti-core antibody in oral fluid collected by postal survey. A random multi-stage stratified sample of Irish households was obtained, using the Irish electoral register as the sampling frame. A total of 962 households were selected, and a household response rate of 60.4% was achieved. Oral fluid specimens totalling 1714 were tested for antibody to hepatitis B core antigen (anti-HBc), using an Immune Capture Enzyme Immuno-Assay. Five specimens (0.29%) were found to contain anti-HBc. Adjusting for study design, the estimated anti-HBc prevalence in the Republic of Ireland is 0.51%. This study demonstrates that self-collection of oral fluid samples is acceptable to the public, and based upon the data generated, that the Republic of Ireland has a low prevalence of hepatitis B infection.

Metallothionein is expressed in adipocytes of brown fat and is induced by catecholamines and zinc

Metallothionein (MT) is thought to have an antioxidant function and is strongly expressed during activation of thermogenesis and increased oxidative stress in brown adipose tissue (BAT). Localization and regulation of MT expression in BAT was therefore investigated in rats and mice. Immunohistochemical analysis of BAT from rats exposed to 4 degrees C for 24 h showed that MT and uncoupling protein 1 (UCP1) were coexpressed in differentiated adipocytes, and both cytoplasmic and nuclear localization of MT was observed. Cold induction of MT-1 expression in BAT was also observed in mice. Administration of norepinephrine to rats and isoproterenol to mice stimulated MT and UCP1 expression in BAT, implying a sympathetically mediated pathway for MT induction. In mice, zinc, and particularly dexamethasone, induced MT-2 expression in BAT and liver. Surprisingly, zinc also induced UCP1 in BAT, suggesting that elevated zinc may induce thermogenesis. We conclude that expression of MT in mature brown adipocytes upon beta-adrenoceptor activation is consistent with a role in protecting against physiological oxidative stress or in facilitating the mobilization or utilization of energy reserves.

The cause of neuronal degeneration in Alzheimer's disease

Alzheimer's disease is associated with a specific pattern of pathological changes in the brain that result in neurodegeneration and the progressive development of dementia. Pathological hallmarks common to the disease include beta-amyloid plaques, dystrophic neurites associated with plaques and neurofibrillary tangles within nerve cell bodies. The exact relationship between these pathological features has been elusive, although it is clear that beta-amyloid plaques precede neurofibrillary tangles in neocortical areas. Examination of the brains of individuals in the preclinical stage of the disease have shown that the earliest form of neuronal pathology associated with beta-amyloid plaques resembles the cellular changes that follow structural injury to axons. Thus, the development of beta-amyloid plaques in the brain may cause physical damage to axons, and the abnormally prolonged stimulation of the neuronal response to this kind of injury ultimately results in the profound cytoskeletal alterations that underlie neurofibrillary pathology and neurodegeneration. Therapeutically, inhibition of the neuronal reaction to physical trauma may be a useful neuroprotective strategy in the earliest stages of Alzheimer's disease.

A practical guide to the management of oesophageal varices

Bleeding oesophageal varices are a frequent and sometimes fatal complication of portal hypertension. Prompt resuscitation and arrest of haemorrhage are the immediate short term priorities. Vasoactive therapy to reduce portal pressure is administered on presentation. Early endoscopy is necessary to make a definitive diagnosis and initiate appropriate therapy; usually emergency sclerotherapy or banding. After the acute bleeding episode, follow-up therapy is instituted either to obliterate the varices by sclerotherapy or banding, or to chronically lower portal pressure and hence reduce the risk of bleeding pharmacologically; a combination of both strategies may be also used. Active surveillance of those at risk of developing varices is advocated. Long term beta-blocker therapy has been demonstrated to be effective in both the primary prevention of variceal haemorrhage and the prevention of rebleeding in those who have already bled. Despite a multitude of therapeutic regimes and ongoing clinical trials, mortality from this condition remains disappointingly high.

The source of disparity vergence innervation determines prism adaptation

A physiological model of prism adaptation argues that adaptation magnitude and rate are functions of the magnitude of reflex vergence innervation. It has also been shown that there is reduced prism adaptation magnitude for a given disparity stimulus where only peripheral sensory fusion is present (the 'eccentricity effect'). This study attempted to determine whether the eccentricity effect is attributable to reduced reflex vergence innervation in peripheral fusion. Experiments were run in a Maxwellian view haploscope. Convergence and divergence adaptation to 6 delta disparity stimuli were quantified for seven binocularly normal subjects using subjective heterophoria measurements. Vergence response during central or peripheral fusion was quantified objectively by infrared oculography. Six of seven subjects revealed an eccentricity effect. However, in three of seven subjects the eccentricity effect was not predictable from the manifest vergence response. The results suggest that the source of reflex vergence innervation affects prism adaptation. A model is proposed whereby different sources of reflex disparity vergence innervation stimulate prism adaptation by way of separate neurological pathways of differing responsiveness.

Infant VEP and preferential looking acuity measured with phase alternating gratings

Previously, infants' grating acuity was found to be temporally tuned, but adults' grating acuity was not. In infants, acuity was higher for gratings phase alternating at 7.5 and 14 reversals/sec than for stationary gratings and gratings alternating at 2.5 or 23 reversals/sec. Also, when preferential looking (PL) and visually evoked potential (VEP) acuity were estimated with phase alternating gratings (14 reversals/sec), the acuity difference between the two techniques was smaller than that obtained when phase alternating gratings were used to estimate VEP acuity and stationary gratings were used to estimate PL acuity. In the present study, it was determined if PL grating acuity was tuned in older children and if the smaller difference between VEP and PL acuity found when infants were tested with phase alternating gratings was independent of temporal rate. Grating acuity in infants older than 2 yr was found to be not tuned, and the smaller difference between VEP and PL grating acuity in infants when both were measured with phase-alternating gratings was not rate dependent. VEP acuity and PL acuity for phase alternating gratings developed at different rates, converging to nearly equivalent levels by 12 mo of age.

Differences in tests of aniseikonia

The New Aniseikonia Test (NAT), a hand-held direct-comparison test using red/green anaglyphs, has several potential advantages as a screener. We compared the validity of the NAT to that of the Space Eikonometer in three experiments: (1) aniseikonia was induced by calibrated size lenses in a double-blind study of 15 normal subjects; (2) habitual aniseikonia was measured with both instruments in four patients; and (3) eight of the normal subjects were retested with a computer-video simulation of the NAT. The NAT underestimated induced aniseikonia by a factor of 3 in the normal subjects and underestimated habitual aniseikonia in four patients. The Space Eikonometer correctly measured the magnitude of induced aniseikonia in the normal subjects. The simulation test did not show underestimation in the eight normal subjects. We could not attribute the NAT's underestimation of aniseikonia to the red/green anaglyph method, printing error, psychophysical method, or the direct-comparison test format. We speculate that the NAT induces a different sensory fusion response to aniseikonia than do the other tests, and that this altered sensory fusion response diminishes measured aniseikonia. We conclude that the NAT is not a valid measure of aniseikonia.

Retinal eccentricity of fusion detail affects vergence adaptation

Adaptation of tonic vergence ("vergence adaptation" or "prism adaptation") may be produced by sustained accommodative, disparity, or proximal vergence innervation. Phoria measures were used in the present study as indices of tonic vergence adaptation to convergence and divergence stimuli in five subjects. Amblyoscope targets stimulated fusion either over the central or peripheral retina while holding accommodative and proximal stimuli constant. The magnitude and rate of tonic vergence adaptation were greater under the central fusion condition than under the peripheral fusion condition, even though the vergence stimuli were matched between central and peripheral fusion conditions. These results show that tonic vergence adaptation is influenced by the retinal eccentricity of target fusional patterns. However, additional work is required to identify the mechanism(s) underlying this eccentricity effect.

Normal retinotopic mapping in human strabismus with anomalous retinal correspondence

Burian proposed that a functional retinotopic remapping of the deviated eye on striate visual cortex may be the physiologic basis for the perceptual phenomenon of anomalous retinal correspondence (ARC) in human strabismus. This investigation searched for this type of retinotopic remapping in five esotropes and one exotrope with ARC by means of visual evoked potential (VEP) topographic mapping. Uniocular stimulation of the foveas (corresponding points) during binocular vision in a normal subject yielded identical VEP scalp topographies from each eye. Stimulation of anomalously corresponding points produced different VEP scalp topographies from each eye in the six strabismic subjects. Uniocular stimulation of the anatomic foveas of each eye (noncorresponding points) in a strabismic subject during binocular vision produced identical VEP scalp topographies. These results suggest that there is no significant functional binocular realignment of retinotopic mapping in the visual cortex of human strabismics with ARC.

Signal to noise ratio considerations in the analysis of sweep visual-evoked potentials

More investigators are recommending rapid sweep displays to estimate visual-evoked potential (VEP) sensory thresholds. Theoretically, phase-sensitive analysis offers a higher signal to noise ratio (SNR) than phase-insensitive techniques and, therefore, a more reliable and equally valid threshold estimate. Phase-sensitive analysis assumes that the VEP phase does not change over the period of one sweep. This study tests the assertion that the VEP phase is sufficiently stable for valid and reliable phase-sensitive detection. Mathematical analysis shows that phase-sensitive detection yields a lower SNR than phase-insensitive analysis if the phase error is < 45 degrees . We recorded the VEP to contrast reversing sinusoidal gratings of sweeping spatial frequency (12.5-0.2 epd) from 26 subjects. In most, phase varied > 180 degrees Over one sweep. Moreover, these large phase shifts could not be diminished by modifying contrast reversal rate, direction of spatial frequency sweep, or sweep time. We conclude that when using spatial frequency sweeps, phase-insensitive detection is superior to phase-sensitive. The filter's bandwidth and the effect of SNR on sensory threshold estimations also are discussed.

Infant grating acuity is temporally tuned

Studies of infant visual development have shown that acuity estimated with pattern visually evoked potential (VEP) techniques is higher than acuity estimated with preferential looking (PL) techniques. A major difference is that VEP stimuli are temporally modulated while PL stimuli are typically stationary. We measured PL acuity in 2-10-month-old infants for stationary gratings and for gratings phase alternating at 2.5, 7.5, 14 and 23 reversals/sec using a computer generated staircase method. The acuity functions were temporally tuned at 7.5 or 14 rev/sec for infants 3 months and older. Acuity for 7.5 and 14 rev/sec gratings was 0.5 to 1.0 octave higher than for stationary, 2.5 and 23 rev/sec gratings. When adults' grating acuity was measured foveally and 5 deg eccentrically, tuning occurred only for the eccentric targets, suggesting that the retinal area used by the infants to detect gratings acts like the adult perifovea. In a second experiment, VEP and PL acuity were both measured from the same infants using 14 reversals/sec gratings. The VEP/PL acuity difference was less for phase alternating gratings than for stationary gratings. The magnitude of the difference was age dependent, decreasing from 2 octaves at 2 months to 0.5 octave at 12 months. Even though the use of phase alternating gratings results in improved PL acuity, temporal modulation does not completely account for the difference between VEP and PL acuity.

Blink vergence in an antimetropic patient

A patient with uncorrected antimetropia was found to attain motor fusion through blinking. Although this patient was also able to attain motor fusion through saccadic vergence and slow fusional vergence, he usually relied on blink vergence. In this patient, blink vergence was an efficient alternative to slow fusional vergence.

Stress management as a component of occupational therapy in acute care settings

The recent explosion of stress literature in the medical community has created a new awareness of "stress" as a potentially destructive force in itself. Contributing the physical and psychological dysfunction, stress has now been linked with a wide range of diagnoses including cancer, cardiac disease and arthritis. The importance of incorporating stress management activities into daily life is increasingly apparent. Occupational therapists concerned with patients' ability to achieve health enhancing independent living skills are in a key position to help patients master stress management skills and incorporate them into activities of daily living. This article will explore the incorporation of stress management into occupational therapy programming for a variety of acute care patients. It will review the components of stress, the stress cycle, the relaxation response, the occupational therapy role based on a model of human occupation, and will review current programs through case study of four patients: one diagnosed with cancer (leukemia), one with anorexia nervosa, one with chronic pain and the fourth, a patient in medical intensive care.

Randomized phase II studies in advanced colorectal carcinoma: a North Central Cancer Treatment Group study

5-FU, semustine (MeCCNU), triazinate (TZT), and razoxane (ICRF-159) have each shown activity against advanced colorectal cancer in studies by at least two investigative groups. Objective response rates, however, have been low, without evidence of increased patient survival. The hope of this study was that enhanced activity might result from giving these agents in two-drug combinations. There were 167 eligible and evaluable patients randomized among the programs: 5-FU at a dose of 500 mg/m2/day by iv push X 5 (F); 5-FU at a dose of 400 mg/m2/day iv X 5 plus TZT at a dose of 175 mg/m2/day iv X 3 (FT); 5-FU at a dose of 400 mg/m2/day plus ICRF-159 at a dose of 600 mg/m2/day orally X 3 (FI); MeCCNU at a dose of 150 mg/m2/day orally plus TZT at a dose of 200 mg/m2/day iv X 3 (MT); MeCCNU at a dose of 150 mg/m2 orally plus ICRF-159 at a dose of 500 mg/m2/day orally X 3 (MI); and ICRF-159 at a dose of 425 mg/m2/day orally X 3 plus TZT at a dose of 125 mg/m2/day iv X 3 (IT). Patients with limiting conditions (serum creatinine greater than 1.5 mg/dl or elevated bilirubin) were randomized among programs F, FI, and MI. Objective response rates by treatment arm were: F--13% (four of 31 patients); FT--13% (four of 31); FI--15% (four of 27); MT--11% (three of 28); MI--13% (four of 32); and IT--6% (one of 17). Response rates of combination arms were not significantly larger than those of 5-FU alone. With regard to survival, patients initially treated with 5-FU alone had the most favorable experience (median, 10.8 mos). Multivariate analysis showed the following factors to have a significant and independent influence on survival: Eastern Cooperative Oncology Group performance score, grade, site of indicator lesion, and the presence of 5-FU in the treatment regimen. Toxic effects most frequently seen were nausea, vomiting, thrombocytopenia, leukopenia, diarrhea, stomatitis, alopecia, and dermatitis. The incidence and severity of toxicity were roughly comparable among the six treatment arms.

Dynamics of cover test eye movements

The dynamics of unilateral cover test eye movements, never before systematically investigated with an objective recording system, are shown to be more complex than textbook accounts of them. We administered the cover test to nine heterophoric subjects by means of electromechanical occluders. Eye movements were recorded using the infrared photoelectric technique. Saccadic and vergence movements of the fixating eye were observed in almost all records when the occluded eye was uncovered. These movements were found in esophores and exophores and in both large and small phoria cases. Such movements were previously described in other asymmetric vergence tasks and appear to obey Hering's law of equal innervation. Uncovering the dominant eye, in cases of clear dominancy, resulted in shorter latency and larger amplitude saccades than did uncovering the nondominant eye. These large saccades were frequently of unequal amplitude in each eye. Trained subjects appear to use dynamic overshoots to increase this saccadic inequality and thereby attain vergence during saccades. Movements after the application of a cover to one eye, while grossly similar to textbook descriptions of them, are found to contain small vergence drifts and refixation (correcting) saccades in the nonoccluded eye.