The pattern of childhood hepatitis B infection in two Gambian villages

Serologic markers of hepatitis B virus (HBV) infection were measured in children from Manduar and Keneba, two adjacent villages in The Gambia, in 1980 and in 1984. The rate of HBV infection over the 4 years differed markedly: in Manduar 71% of children who were less than 5 years of age in 1980 became infected, whereas in Keneba only 37% became infected. Male children were more frequent carriers of either HBs or e antigen than were female children. Marked clustering of hepatitis B surface antigen (HBsAg) antigenemia within sibling relationships was shown in both villages. The chance of the youngest child in a household being a carrier of HBsAg was strongly related to the number of antigen-positive siblings. Four years later, 53% of children who were initially positive for HBsAg and 33% who were positive for hepatitis B e antigen still carried these antigens. Jaundice was not observed.

High prevalence of CCDC103 p.His154Pro mutation causing primary ciliary dyskinesia disrupts protein oligomerisation and is associated with normal diagnostic investigations

RATIONALE

Primary ciliary dyskinesia is a genetically heterogeneous inherited condition characterised by progressive lung disease arising from abnormal cilia function. Approximately half of patients have situs inversus. The estimated prevalence of primary ciliary dyskinesia in the UK South Asian population is 1:2265. Early, accurate diagnosis is key to implementing appropriate management but clinical diagnostic tests can be equivocal.

OBJECTIVES

To determine the importance of genetic screening for primary ciliary dyskinesia in a UK South Asian population with a typical clinical phenotype, where standard testing is inconclusive.

METHODS

Next-generation sequencing was used to screen 86 South Asian patients who had a clinical history consistent with primary ciliary dyskinesia. The effect of a CCDC103 p.His154Pro missense variant compared with other dynein arm-associated gene mutations on diagnostic/phenotypic variability was tested. CCDC103 p.His154Pro variant pathogenicity was assessed by oligomerisation assay.

RESULTS

Sixteen of 86 (19%) patients carried a homozygous CCDC103 p.His154Pro mutation which was found to disrupt protein oligomerisation. Variable diagnostic test results were obtained including normal nasal nitric oxide levels, normal ciliary beat pattern and frequency and a spectrum of partial and normal dynein arm retention. Fifteen (94%) patients or their sibling(s) had situs inversus suggesting CCDC103 p.His154Pro patients without situs inversus are missed.

CONCLUSIONS

The CCDC103 p.His154Pro mutation is more prevalent than previously thought in the South Asian community and causes primary ciliary dyskinesia that can be difficult to diagnose using pathology-based clinical tests. Genetic testing is critical when there is a strong clinical phenotype with inconclusive standard diagnostic tests.

A study of the quality of perinatal autopsy in the former northern region. The Northern Perinatal Mortality Survey Steering Group

OBJECTIVE

To assess the quality of perinatal autopsy.

DESIGN

Review of all reports of post mortem examinations carried out following perinatal deaths from January 1994 to June 1994.

POPULATION

Former Northern Region of England.

METHODS

Assessment of post mortem reports concerning their content and interpretation, the assessment carried out by panel comprising a pathologist, obstetrician and paediatrician.

RESULTS

Reports were available for all 104 cases where post mortem examinations had been undertaken, of which 53 (51%) met the minimum standards for such autopsies proposed by the Royal College of Pathologists. Interpretative comments were judged to be adequate in 51 (49%).

CONCLUSIONS

The quality of perinatal autopsies is frequently poor. Improvement requires increased awareness of the potential value of the autopsy, and more consultation between pathologists, obstetricians and paediatricians.

Encopresis: a study of treatment alternatives and historical and behavioral characteristics

The historical, demographic and pre/post treatment behavioral profiles of a Health Maintenance Organization's (HMO) encopresis patients were studied. The efficacy of two maintenance treatments were also compared. Management included an initial bowel evacuation, high fiber diet, behavior modification program, and random assignment to maintenance on oral laxatives or conditional rectal cathartics. Of the 136 patients evaluated, 61 completed treatment (oral 24; rectal 37). Significant behavioral problems were identified. However, the majority (65%) of patients were managed without psychosocial intervention and successful completion of treatment significantly improved most behaviors. There were no significant differences in efficacy between the oral laxative or conditional rectal cathartic maintenance groups completing treatment. In 87% success continued 6 to 12 months post-treatment.

Luminescence, Electron Paramagnetic Resonance, and Optical Properties of Lunar Material

Dust samples have been found to luminesce weakly under proton excitation, but not under ultraviolet. Damage, recovery, and heating effects have been investigated. Chips of breccia show luminescence, from white inclusions only, under ultraviolet and protons. Some rock chips show general luminescence, mainly from plagioclase. No natural or excited thermoluminescence has been found for dust or chips. The electron paramagnetic resonance spectrum shows the same broad Fe(3+) dipole resonance for dust and for some chips; other chips show no response. The polarization characteristics of dust are found to be identical to those of the Sea of Tranquillity, independently of proton damage. Chips show characteristics unlike any part of the lunar surface.

Transcriptomics of CD29+/CD44+ cells isolated from hPSC retinal organoids reveals a single cell population with retinal progenitor and Müller glia characteristics

Müller glia play very important and diverse roles in retinal homeostasis and disease. Although much is known of the physiological and morphological properties of mammalian Müller glia, there is still the need to further understand the profile of these cells during human retinal development. Using human embryonic stem cell-derived retinal organoids, we investigated the transcriptomic profiles of CD29+/CD44+ cells isolated from early and late stages of organoid development. Data showed that these cells express classic markers of retinal progenitors and Müller glia, including NFIX, RAX, PAX6, VSX2, HES1, WNT2B, SOX, NR2F1/2, ASCL1 and VIM, as early as days 10-20 after initiation of retinal differentiation. Expression of genes upregulated in CD29+/CD44+ cells isolated at later stages of organoid development (days 50-90), including NEUROG1, VSX2 and ASCL1 were gradually increased as retinal organoid maturation progressed. Based on the current observations that CD24+/CD44+ cells share the characteristics of early and late-stage retinal progenitors as well as of mature Müller glia, we propose that these cells constitute a single cell population that upon exposure to developmental cues regulates its gene expression to adapt to functions exerted by Müller glia in the postnatal and mature retina.

Distributional fixed-point equations for island nucleation in one dimension: a retrospective approach for capture-zone scaling

The distributions of interisland gaps and captures zones for islands nucleated on a one-dimensional substrate during submonolayer deposition are considered using a novel retrospective view. This provides an alternative perspective on why scaling occurs in this continuously evolving system. Distributional fixed-point equations for the gaps are derived both with and without a mean-field approximation for nearest neighbor gap-size correlation. Solutions to the equations show that correct consideration of fragmentation bias justifies the mean-field approach, which can be extended to provide closed-from equations for the capture zones. Our results compare favorably to Monte Carlo data for both point and extended islands using a range of critical island size i=0,1,2,3. We also find satisfactory agreement with theoretical models based on more traditional fragmentation theory approaches.

Gap-size and capture-zone distributions in one-dimensional point-island nucleation and growth simulations: asymptotics and models

The nucleation and growth of point islands during submonolayer deposition on a one-dimensional substrate is simulated for critical island size i=0,1,2,3. The small- and large-size asymptotics for the gap-size and capture-zone distributions (CZDs) are studied. Comparisons to theoretical predictions from fragmentation equation analyses are made, along with those from the recently proposed generalized Wigner surmise (GWS). We find that the simulation data can be fully understood in the framework provided by the fragmentation equations, while highlighting the theoretical areas that require further development. The GWS works well for the small-size CZD behavior, but completely fails to describe the large-size CZD asymptotics of the one-dimensional system.

Cell-Based Therapies for Glaucoma

Glaucomatous optic neuropathy (GON) is the major cause of irreversible visual loss worldwide and can result from a range of disease etiologies. The defining features of GON are retinal ganglion cell (RGC) degeneration and characteristic cupping of the optic nerve head (ONH) due to tissue remodeling, while intraocular pressure remains the only modifiable GON risk factor currently targeted by approved clinical treatment strategies. Efforts to understand the mechanisms that allow species such as the zebrafish to regenerate their retinal cells have greatly increased our understanding of regenerative signaling pathways. However, proper integration within the retina and projection to the brain by the newly regenerated neuronal cells remain major hurdles. Meanwhile, a range of methods for in vitro differentiation have been developed to derive retinal cells from a variety of cell sources, including embryonic and induced pluripotent stem cells. More recently, there has been growing interest in the implantation of glial cells as well as cell-derived products, including neurotrophins, microRNA, and extracellular vesicles, to provide functional support to vulnerable structures such as RGC axons and the ONH. These approaches offer the advantage of not relying upon the replacement of degenerated cells and potentially targeting earlier stages of disease pathogenesis. In order to translate these techniques into clinical practice, appropriate cell sourcing, robust differentiation protocols, and accurate implantation methods are crucial to the success of cell-based therapy in glaucoma. Translational Relevance: Cell-based therapies for glaucoma currently under active development include the induction of endogenous regeneration, implantation of exogenously derived retinal cells, and utilization of cell-derived products to provide functional support.

MicroRNA profile of extracellular vesicles released by Müller glial cells

Introduction

As with any other radial glia in the central nervous system, Müller glia derive from the same neuroepithelial precursors, perform similar functions, and exhibit neurogenic properties as radial glia in the brain. Müller glial cells retain progenitor-like characteristics in the adult human eye and can partially restore visual function upon intravitreal transplantation into animal models of glaucoma. Recently, it has been demonstrated that intracellular communication is possible via the secretion of nano-sized membrane-bound extracellular vesicles (EV), which contain bioactive molecules like microRNA (miRNA) and proteins that induce phenotypic changes when internalised by recipient cells.

Methods

We conducted high-throughput sequencing to profile the microRNA signature of EV populations secreted by Müller glia in culture and used bioinformatics tools to evaluate their potential role in the neuroprotective signalling attributed to these cells.

Results

Sequencing of miRNA within Müller EV suggested enrichment with species associated with stem cells such as miR-21 and miR-16, as well as with miRNA previously found to play a role in diverse Müller cell functions in the retina: miR-9, miR-125b, and the let-7 family. A total of 51 miRNAs were found to be differentially enriched in EV compared to the whole cells from which EV originated. Bioinformatics analyses also indicated that preferential enrichment of species was demonstrated to regulate genes involved in cell proliferation and survival, including PTEN, the master inhibitor of the PI3K/AKT pathway.

Discussion

The results suggest that the release by Müller cells of miRNA-enriched EV abundant in species that regulate anti-apoptotic signalling networks is likely to represent a significant proportion of the neuroprotective effect observed after the transplantation of these cells into animal models of retinal ganglion cell (RGC) depletion. Future studies will seek to evaluate the modulation of putative genes as well as the activation of these pathways in in vitro and in vivo models following the internalisation of Müller-EV by target retinal neurons.

Type 1 diabetes in North East England and North Cumbria: patterns and time trends in 0-14-year-olds from 2012 to 2020

Introduction

It is important to understand patterns in the epidemiology of type 1 diabetes because they may provide insight into its etiology. We examined the incidence of type 1 diabetes in children aged 0-14 years, and patient demographics and clinical parameters at presentation, over the period 2012-2020 using the North East and North Cumbria Young Persons diabetes register.

Methods

Patients up to the age of 14 years with type 1 diabetes, and their families- managed in a total of 18 young persons diabetes clinics-were approached in person at the time of clinic appointments or in the days following diagnosis and they consented to their data being included in the register. Data were submitted regionally to a central unit. Descriptive statistics including crude and age-specific incidence rates were calculated. Temporal trends were analyzed using Joinpoint regression. Comparisons in incidence rates were made between age, sex and areas of higher and lower affluence as measured by the Index of Multiple Deprivation (IMD).

Results

A total of 943 cases were recorded between January 2012 and December 2020. Median age at diagnosis was 8.8 years (Q1: 5.3, Q3: 11.7). There were more males than females (54% male). The median HbA1c at diagnosis was 100 mmoL/L (IQR: 39) and over one third (35%) were in ketoacidosis (pH < 7.3). Crude incidence decreased from 25.5 (95% confidence interval [CI] 20.9, 29.9) in 2012 to 16.6 (95% CI: 13.0, 20.2) per 100,000 in 2020 (5.1% per annum, 95% CI 1.1, 8.8%). During the period of the study there was no evidence of any trends in median age, HbA1c, BMI or birthweight (p = 0.18, 0.80, 0.69, 0.32) at diagnosis. Higher rates were observed in males aged 10-14 years, but similar rates were found for both sexes aged 0-9 years and there was no difference between areas of higher or lower deprivation (p = 0.22).

Conclusion

The incidence of diabetes in the young may be falling in the North East of England and North Cumbria. The reasons are unclear as there were no associations identified between levels of deprivation or anthropometric measurements. Potential mechanisms include alterations in socioeconomic background or growth pattern. Further research is needed to understand the reasons behind this finding.