Butyrate Shapes Immune Cell Fate and Function in Allergic Asthma

The microbiome plays a fundamental role in how the immune system develops and how inflammatory responses are shaped and regulated. The “gut-lung axis” is a relatively new term that highlights a crucial biological crosstalk between the intestinal microbiome and lung. A growing body of literature suggests that dysbiosis, perturbation of the gut microbiome, is a driving force behind the development, and severity of allergic asthma. Animal models have given researchers new insights into how gut microbe-derived components and metabolites, such as short-chain fatty acids (SCFAs), influence the development of asthma. While the full understanding of how SCFAs influence allergic airway disease remains obscure, a recurring theme of epigenetic regulation of gene expression in several immune cell compartments is emerging. This review will address our current understanding of how SCFAs, and specifically butyrate, orchestrates cell behavior, and epigenetic changes and will provide a detailed overview of the effects of these modifications on immune cells in the context of allergic airway disease.

Neurofilament Proteins as Prognostic Biomarkers in Neurological Disorders

Neurofilaments: light, medium, and heavy (abbreviated as NF-L, NF-M, and NF-H, respectively), which belong to Type IV intermediate filament family (IF), are neuron-specific cytoskeletal components. Neurofilaments are axonal structural components and integral components of synapses, which are important for neuronal electric signal transmissions along the axons and post-translational modification. Abnormal assembly of neurofilaments is found in several human neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), infantile spinal muscular atrophy (SMA), and hereditary sensory-motor neuropathy (HSMN). In addition, those pathological neurofilament accumulations are known in α-synuclein in Parkinson's disease (PD), Aβ and tau in Alzheimer's disease (AD), polyglutamine in CAG trinucleotide repeat disorders, superoxide dismutase 1 (SOD1), TAR DNA-binding protein 43 (TDP43), neuronal FUS proteins, optineurin (OPTN), ubiquilin 2 (UBQLN2), and dipeptide repeat protein (DRP) in amyotrophic lateral sclerosis (ALS). When axon damage occurs in central nervous disorders, neurofilament proteins are released and delivered into cerebrospinal fluid (CSF), which are then circulated into blood. New quantitative analyses and assay techniques are well-developed for the detection of neurofilament proteins, particularly NF-L and the phosphorylated NF-H (pNF-H) in CSF and serum. This review discusses the potential of using peripheral blood NF quantities and evaluating the severity of damage in the nervous system. Intermediate filaments could be promising biomarkers for evaluating disease progression in different nervous system disorders.

Impact of Recurrence Score on type and duration of chemotherapy in breast cancer

Background

The use of Oncotype dx (Genomic Health, Redwood City, CA, U.S.A.) testing has been shown to change treatment decisions in approximately 30% of breast cancer (bca) cases, but research on how Recurrence Score testing has affected the type of chemotherapy offered is limited. We sought to determine if the availability of Oncotype dx testing resulted in a change to the type and duration of chemotherapy regimens used in the treatment of early-stage hormone receptor-positive bca.

Methods

In a population-based cohort study, patients treated in the 2 years before the availability of Oncotype dx testing were compared with patients treated in the 2 years after testing availability. Charts were audited and divided into 2 groups: pre-Oncotype dx and post-Oncotype dx. The groups were compared for differences in duration of chemotherapy (12 weeks vs. >12 weeks), types of agents used (anthracycline vs. non-anthracycline), and myelosuppressive potential of the chosen regimen.

Results

Of 834 patients who fulfilled the enrolment criteria, 360 fell into the pre-Oncotype dx era, and 474, into the post-Oncotype dx era. An increase of 11.2 percentage points, to 69.5% from 58.3%, was observed in the proportion of patients receiving short-course compared with long-course chemotherapy (p = 0.068). The proportion of patients prescribed anthracycline-containing regimens declined in the post-Oncotype dx era (47.7% pre vs. 32.2% post, p = 0.016). The selection of more-myelosuppressive chemotherapy protocols increased in the post-Oncotype dx era (67.4% pre vs. 78.8% post, p = 0.044).

Conclusions

In the present study, the availability of Oncotype dx testing was observed to influence the choice of chemotherapy type in the setting of early-stage bca.

Depletion of SCFA-fermenting gut bacteria alters the epigenome of hematopoietic stem and progenitor cells

Gut dysbiosis alters the development and severity of atopic disease. We previously demonstrated that nursing dams and newborn mice treated with low-dose vancomycin alters gut microbial diversity with a marked loss of bacteria that produce short-chain fatty acids (including butyrate). Vancomycin-induced gut dysbiosis enhances the TH2 response to lung allergens due to altered dendritic cell trafficking and activation in addition to modifying the behavior of other mature leukocyte lineages. Butyrate supplementation reverses the vancomycin-induced TH2 pro-inflammatory phenotype.

Butyrate is known to exert some of its effects on target cells by inhibiting histone deacetylases (HDACs) with consequent effects on gene expression. Consistent with a role for epigenetic skewing of the hematopoietic compartment, we found that engraftment of total bone marrow from dysbiotic mice transferred enhanced TH2 proclivity in normobiotic recipients. Strikingly, we found unique regulatory states (H3K27ac marks) in purified hematopoietic stem and progenitor cells (HSPC) of TH2-skewed recipient mice. Single cell RNA sequence analyses identified a distinct transcriptomic signature in HSPC of dysbiotic mice that was reversed by butyrate supplementation. Together, these data suggest that the gut microbiome alters gene expression in blood progenitor cells with long term consequences on the immune response to peripheral allergens.

A novel "in-situ tulip-bud deployment" method for transcatheter closure of secundum atrial septal defect

OBJECTIVE

We devised a new technique for interventional closure of atrial septal defect (ASD) using the Amplatzer Septal Occluder (ASO), and validated this by comparing it with a cohort using the conventional method.

BACKGROUND

Transcatheter closure of ASD is a widely accepted modality of treatment. Although the outcome is good, there are occasional technical difficulties encountered.

METHOD

In this three-step technique, the device is protruded to form a "tulip bud." This "tulip bud" is then aligned adjacent to and along the plane of the ASD. The second step involves withdrawing the sheath in quick succession to deploy atrial discs over the septal defect. Finally, good placement of the occluder is checked before release.

RESULTS

Twenty-seven consecutive patients (1.4-77.2 years of age, median = 15) underwent device closure by this method. Nineteen (70.4%) had a deficient aortic rim (< 5 mm). Mean (+/- SD) ASD size by transesophageal echocardiography (TEE) was 16.0 +/- 5.1 mm. The chosen ASO size was 122 +/- 8% of the ASD size. The mean (+/- SD) duration of deployment and of deployment to release was 1.27 +/- 1.91 minutes and 5.18 +/- 2.63 minutes, respectively. The total fluoroscopy and procedure time was 9.93 +/- 5.61 minutes and 68.67 +/- 28.39 minutes, respectively. Twenty-one out of 27 patients (77.8%) had closure in one attempt. Comparing these 27 patients with the previous 48 consecutive patients with a deficient aortic rim by the conventional method, there was no difference in age, body weight, Qp/Qs, ASD size and ASO size or degree of oversizing (p > 0.05). The percentage of patients with aortic root deficiency was slightly higher in "tulip-bud" group compared to the conventional group (63.2% vs. 58.4%; p = 0.039). No complications were observed in either series.

CONCLUSION

This is a promising new method to circumvent some of the difficulties associated with closure of large ASDs and deficient aortic rim.

Multiple scattering effects on optical characterization of biological tissue using spectroscopic scattering parameters

Spectroscopic optical parameters measured from biological tissue have been used to estimate the size distribution and density of subcellular particles. The calculations are usually performed under an independent scattering assumption, where scattering of a particle ensemble is assumed to be the linear summation of individual particle scattering. We use rigorous numerical solutions of Maxwell's equations to investigate the validity of this independent scattering assumption and find that interparticle scattering can have significant contributions to the optical parameters of biological tissue. In addition, we find that the reduced scattering coefficient is less affected by multiple scattering compared to the scattering coefficient and thus in general produces better results for the inverse calculation. These observations may be useful in improving the characterization of biological tissues based on their spectroscopic light scattering measurements.

DOT in rural China: experience from a case study in Shandong Province, China

SETTING

Four counties at varying levels of economic development in Shandong Province were sampled. All offered tuberculosis (TB) directly observed treatment (DOT) treatment at the County TB Dispensary (CTBD).

OBJECTIVE

To empirically document how DOT and home visits were implemented in rural China and to shed light on whether DOT is one of the key elements through which China achieves its high cure rates for TB.

DESIGN

A total of 404 rural smear-positive TB patients registered in the CTBDs were interviewed face-to-face with structured questionnaires. Village doctors and key informants from the CTBDs were also interviewed.

RESULTS

The majority of TB patients in rural areas do not receive DOT from village doctors and rarely get support, such as visits as required, from the CTBDs or township health providers in Shandong, China.

CONCLUSION

The lack of DOT in Shandong does not have a negative effect on TB treatment outcomes. Given that the DOTS strategy is still the core measure of TB control in China, implementation of other programme elements apart from DOT is necessary to ensure a successful TB treatment programme.

Trends in rural and urban differentials in incidence rates for ruptured appendicitis under the National Health Insurance in Taiwan

OBJECTIVES

Rural-urban disparities in health remain a major focus of concern. This population-based study examined the performance of Taiwan's universal healthcare system in reducing rural-urban disparities in health, through better accessibility. Changes in the rates of ruptured appendicitis were compared between residents of remote and non-remote areas in Taiwan, under the National Health Insurance (NHI) programme.

METHODS

We identified all 128,930 patients undergoing appendectomy in Taiwan between 1996 and 2001. The NHI inpatient files, enrolment files, major disease files, hospital registry and the household registry were linked to provide comprehensive individual and hospital information. Probit regression analyses were used to obtain adjusted estimates.

RESULTS

During the first 3 years, although the differences between the remote and non-remote areas were apparent, they were seen to be narrowing. This downward trend continued, and, since 1999, few discernible differences have been observed. After adjusting for individual and hospital characteristics, over time, the ruptured appendix rate among remote area residents was seen to be decreasing significantly faster (1.1%) than among non-remote area residents. More specifically, the children showed a substantially steeper narrowing trend (3.3%) in rural-urban disparities, than did adults.

CONCLUSIONS

Our findings have shown a significant narrowing of health disparities between remote and non-remote populations, resulting from free access to care and more healthcare provision in remote areas under the NHI programme; particular success has been observed in rural children. Although certain disparities still exist, Taiwan's universal healthcare system has effectively reduced rural-urban disparities in access to care and in ultimate health outcomes.

Provider payment reform in China: the case of hospital reimbursement in Hainan province

This paper develops a simple model of payment incentives and empirically evaluates provider payment reform in Hainan Province, China. We use a pre-post study design with a control group to analyse two years of claims data to assess the impact of a January 1997 change to prospective payment for a sub-sample of the hospitals. This difference-in-difference empirical strategy allows us to isolate the supply-side payment reform effects from demand-side changes, in contrast with previous studies of China's reforms. Our results validate the theory that Chinese providers' behavioural response to payment incentives is similar to that reported in the literature derived from the experience of industrialized countries. We find that prepayment is associated with a slower rate of growth of overall expenditures, programme spending and patient co-payments per inpatient admission, compared to fee-for-service (FFS). These findings suggest cautious optimism regarding the effectiveness of prospective payment for controlling costs and should be encouraging for policymakers in developing and transitional economies considering replacement of FFS with more aggregated forms of provider payment.

Targeted health insurance in a low income country and its impact on access and equity in access: Egypt's school health insurance

Governments are constantly faced with competing demands for public funds, thereby necessitating careful use of scarce resources. In Egypt, the School Health Insurance Programme (SHIP) is a government subsidized health insurance system that targets school children. The primary goals of the SHIP include improving access and equity in access to health care for children while, at the same time, ensuring programme sustainability. Using the Egyptian Household Health Utilization and Expenditure Survey (1995), this paper empirically assesses the extent to which the SHIP achieves its stated goals. Our findings show that the SHIP significantly improved access by increasing visit rates and reducing financial burden of use (out-of-pocket expenditures). With regard to the success of targeting the poor, conditional upon being covered, the SHIP reduced the differentials in visit rates between the highest and lowest income children. However, only the middle-income children benefitted from reduced financial burden (within group equity). Moreover, by targeting the children through school enrollment, the SHIP increased the differentials in the average level of access between school-going children and those not attending school (overall equity). Children not attending school tend to be poor and living in rural areas. Our results also indicate that original calculations may underestimate the SHIP financial outlays, thereby threatening the long run financial sustainability of the programme.

Selection of a cardiac surgery provider in the managed care era

OBJECTIVE

Many health planners promote the use of competition to contain cost and improve quality of care. Using a standard econometric model, we examined the evidence for "value-based" cardiac surgery provider selection in eastern Massachusetts, where there is significant competition and managed care penetration.

METHODS

McFadden's conditional logit model was used to study cardiac surgery provider selection among 6952 patients and eight metropolitan Boston hospitals in 1997. Hospital predictor variables included beds, cardiac surgery case volume, objective clinical and financial performance, reputation (percent out-of-state referrals, cardiac residency program), distance from patient's home to hospital, and historical referral patterns. Subgroup analyses were performed for each major payer category.

RESULTS

Distance from patient's home to hospital (odds ratio 0.90; P =.000) and the historical referral pattern from each patient's hometown (z = 45.305; P =.000) were important predictors in all models. A cardiac surgery residency enhanced the probability of selection (odds ratio 5.25; P =.000), as did percent out-of-state referrals (odds ratio 1.10; P =.001). Higher mortality rates were associated with decreased probability of selection (odds ratio 0.51; P =.027), but higher length of stay was paradoxically associated with greater probability (odds ratio 1.72; P =.000). Total hospital costs were irrelevant (odds ratio 1.00; P =.179). When analyzed by payer subgroup, Medicare patients appeared to select hospitals with both low mortality (odds ratio 0.43; P =.176) and short length of stay (odds ratio 0.76; P =.213), although the results did not achieve statistical significance. The commercial managed care subgroup exhibited the least "value-based" behavior. The odds ratio for length of stay was the highest of any group (odds ratio = 2.589; P =.000) and there was a subset of hospitals for which higher mortality was actually associated with greater likelihood of selection.

CONCLUSIONS

The observable determinants of cardiac surgery provider selection are related to hospital reputation, historical referral patterns, and patient proximity, not objective clinical or cost performance. The paradoxic behavior of commercial managed care probably results from unobserved choice factors that are not primarily based on objective provider performance.

Abdominal coarctation and Alagille syndrome

Structural cardiac defects such as peripheral pulmonary stenosis are well-described in Alagille syndrome (AS), which is transmitted in an autosomal dominant inheritance. The genetic defect, with incomplete penetrance and variable expression, is localized to the short arm of chromosome 20. Abdominal coarctation is an uncommon congenital anomaly, with a spectrum of symptoms that may range from hypertension, intermittent claudication to abdominal pain. The association of abdominal coarctation with AS is rarely described. We report such a patient who also had aberrations of the visceral vascular supply involving the celiac, splenic, and superior mesenteric arteries. The indications to treat the coarctation, and in the context of a patient with AS, in whom liver transplantation may be contemplated at some stage, merit discussion.

Health reform for children: the Egyptian experience with school health insurance

In June 1992, the People's Assembly of Egypt passed Law 99 expanding health insurance to cover all school children. This was one of the most important initiatives undertaken in recent years by the Ministry of Health, and it effectively increased the number of beneficiaries covered by the Health Insurance Organization (HIO) from 3.75 million in 1988 to about 14 million in 1993. This paper first examines the policy processes for the introduction of this innovation in Egypt's health system. Next, the paper discusses the implementation and consequences of the new policy in terms of coverage, financing, benefits, and delivery of services, along with data on utilization and expenditures. Several important lessons derive from this analysis. First, major reform efforts are possible when there is a strong political commitment and the proposed program and solutions are acceptable to the key stakeholders. Second, compromises and trade-offs are essential to construct a politically feasible and ethically acceptable reform initiative. Third, while these trade-offs might yield short-term gains, the trade-offs in the long term may undermine the reform's capacity to achieve the anticipated equity enhancements and can potentially undermine the financial sustainability of the reform.

Cardiac manifestations in tuberous sclerosis: a 10-year review

OBJECTIVE

Tuberous sclerosis is a genetic disorder with multisystem involvement. The aim of this study was to focus primarily on the cardiac aspects of this condition.

METHOD

This review included 10 children with tuberous sclerosis presenting to our department during a 10-year period.

RESULTS

From our data, 80% were found to have cardiac involvement. There was an equal prevalence of neurologic complications.

CONCLUSIONS

Cardiac tumours and seizures were the most common problems encountered. Whereas most patients had no symptoms referable to the cardiovascular system and required no active intervention, many of those with neurologic involvement needed appropriate treatment.

Mental health care utilization in prepaid and fee-for-service plans among depressed patients in the Medical Outcomes Study

OBJECTIVE

We compare mental health utilization in prepaid and fee-for-service plans and analyze selection biases.

DATA SOURCE

Primary data were collected every six months over a two-year interval for a panel of depressed patients participating in the Medical Outcomes Study, an observational study of adults in competing systems of care in three urban areas (Boston, Chicago, and Los Angeles).

STUDY DESIGN

Patients visiting a participating clinician at baseline were screened for depression, followed by a telephone interview, which included the depression section of the NIMH Diagnostic Interview Schedule. Patients with current or past lifetime depressive disorder and those with depressed mood and three other lifetime symptoms were eligible for this analysis. We analyze mental health utilization based on periodic patient self-report. ANALYTIC METHODS: We use two-part models because of the presence of both nonuse and skewness of use. Standard errors are corrected nonparametrically for correlations across observations due to clustered sampling within participating physicians and repeated observations on the same individual.

PRINCIPAL FINDINGS

The average number of mental health visits was 35-40 percent lower in the prepaid system, adjusted and unadjusted for observed differences in patient characteristics, including health status. Utilization differences were concentrated among patients of psychiatrists, with only minor differences among patients of general medical providers. Analyzing the effect of switches that patients make between payment systems over time, we found some evidence of adverse selection into fee-for-service plans based on baseline utilization, but not based on utilization at the end of the study. In particular, after adjusting for observed patient characteristics and health status, patients switching out of prepaid plans had higher baseline use than predicted, whereas patients switching out of fee-for-service had lower use than predicted. Switching itself appears to be related to an immediate decline in utilization and was not followed by an increase or "catch-up" effect.

CONCLUSIONS

The absence of the commonly found "catch-up" effect following switching and the significant decrease in utilization during the switching period suggests an interruption in care that does not occur for patients staying within a payment system. This finding emphasizes the need for integrating new patients quickly into a system, an issue that should not be neglected in the current policy discussion.

Border crossing for hospital care and its implications for the use of statewide data

A major concern of researchers using state data sets for population-based analyses and market share studies in the health care sector is the potential bias caused by 'border crossing'--patients receiving care out of state. By using the Health Care Financing Administration (HCFA) discharge abstract files for 1987 and 1988, we found that 'border crossing' is not a serious problem for the two large states we examined. Only 4.4% of New York patients and 2.15% of California patients received care out of state. At the county and zip code level, 'border crossing' is more frequent but tends to be concentrated in areas adjacent to other states. Even excluding all zips with more than 10% of patients crossing the 'border' results in a small loss of patients (2.2% for New York and 1.0% for California).