Electrical Impedance Spectroscopy Quantifies Skin Barrier Function in Organotypic In Vitro Epidermis Models.

3 D human epidermal equivalents (HEEs) are a state-of-the-art organotypic culture model in pre-clinical investigative dermatology and regulatory toxicology. Here, we investigated the utility of electrical impedance spectroscopy (EIS) for non-invasive measurement of HEE epidermal barrier function. Our setup comprised a custom-made lid fit with 12 electrode pairs aligned on the standard 24-transwell cell culture system. Serial EIS measurements for seven consecutive days did not impact epidermal morphology and readouts showed comparable trends to HEEs measured only once. We determined two frequency ranges in the resulting impedance spectra: a lower frequency range termed EISdiff correlated with keratinocyte terminal differentiation independent of epidermal thickness and a higher frequency range termed EISSC correlated with stratum corneum thickness. HEEs generated from CRISPR/Cas9 engineered keratinocytes that lack key differentiation genes FLG, TFAP2A, AHR or CLDN1 confirmed that keratinocyte terminal differentiation is the major parameter defining EISdiff. Exposure to pro-inflammatory psoriasis- or atopic dermatitis-associated cytokine cocktails lowered the expression of keratinocyte differentiation markers and reduced EISdiff. This cytokine-associated decrease in EISdiff was normalized after stimulation with therapeutic molecules. In conclusion, EIS provides a non-invasive system to consecutively and quantitatively assess HEE barrier function and to sensitively and objectively measure barrier development, defects and repair.

De novo mutation in the SCN5A gene associated with early onset of sudden infant death.

BACKGROUND: Congenital long QT syndrome (LQTS), a cardiac ion channel disease, is an important cause of sudden cardiac death. Prolongation of the QT interval has recently been associated with sudden infant death syndrome, which is the leading cause of death among infants between 1 week and 1 year of age. Available data suggest that early onset of congenital LQTS may contribute to premature sudden cardiac death in otherwise healthy infants. METHODS AND RESULTS: In an infant who died suddenly at the age of 9 weeks, we performed mutation screening in all known LQTS genes. In the surface ECG soon after birth, a prolonged QTc interval (600 ms(1/2)) and polymorphic ventricular tachyarrhythmias were documented. Mutational analysis identified a missense mutation (Ala1330Pro) in the cardiac sodium channel gene SCN5A, which was absent in both parents. Subsequent genetic testing confirmed paternity, thus suggesting a de novo origin. Voltage-clamp recordings of recombinant A1330P mutant channel expressed in HEK-293 cells showed a positive shift in voltage dependence of inactivation, a slowing of the time course of inactivation, and a faster recovery from inactivation. CONCLUSIONS: In this study, we report a de novo mutation in the sodium channel gene SCN5A, which is associated with sudden infant death. The altered functional characteristics of the mutant channel was different from previously reported LQTS3 mutants and caused a delay in final repolarization. Even in families without a history of LQTS, de novo mutations in cardiac ion channel genes may lead to sudden cardiac death in very young infants.

Community income and surgical rates in the Netherlands.

BACKGROUND: The study describes variations in use of surgical procedures by community income in the Netherlands. From the literature it is known that surgical rates have a socioeconomic gradient. Both positive and negative associations of socioeconomic factors of patients (for example, income, education) with surgical rates have been reported. The question raised here is: how do (possible) socioeconomic variations in surgery in the Netherlands compare with variations observed elsewhere? DATA AND METHODS: The data comprised Dutch hospital discharges and population estimates for 1999. Socioeconomic status was indicated by a patient's income and based on the average family income of the postcode area of residence. Poisson regression was used to compute relative incidence (odds ratios) for 10 common surgical procedures. The model included age, gender, degree of urbanisation, and province of residence. RESULTS: The association between surgical rates and community level income is rather weak. For half of the surgical rates the authors observed higher utilisation rates in communities with low income levels, but the differences are small. The range of odds ratios in the lowest income quintile group (compared with the group with the highest income) observed is: 0.87 to 1.18. Men from a low income community received more appendicectomies (1.18), cholecystectomies (1.12), knee replacements (1.06), and prostatectomies (1.14) and less tonsillectomies (0.90). Women from a low income community received more appendicectomies (1.12), caesarean sections (1.18), hip and knee replacements (1.05,1.17), and hysterectomies (1.14). Whereas they received less coronary artery bypass grafts (0.92), cholecystectomies (0.87), and tonsillectomies (0.92). CONCLUSIONS: Compared with findings reported in the international literature, this study indicates that variations in use of surgical procedures by community income in the Netherlands are comparatively small. Because of lack of data the authors could not study the influence of variations in need for surgical care by community income, but as the incidence of conditions requiring surgical interventions generally is higher in lower income groups, it is suspected some degree of underutilisation exists in these groups.

Socioeconomic variations in the course of stroke: unequal health outcomes, equal care?

STUDY OBJECTIVE: The aim of this paper is to quantify the socioeconomic gap in long term health outcomes after stroke and related health care utilisation, in order to evaluate whether those in need of care do actually receive appropriate levels of care. DESIGN: Stroke patients from the lower socioeconomic group were compared with stroke patients from the higher socioeconomic group with respect to sociodemographic and clinical characteristics, health outcomes, and related health care utilisation. SETTING: Patients were recruited from admissions to 23 randomly selected hospitals in the Netherlands. PATIENTS: 465 patients were included who had had a stroke six months earlier and were followed up three years and five years after stroke. MAIN RESULTS: The observed odds ratios suggest that patients from the lower socioeconomic group experienced more disabilities up to three years after stroke and more handicaps up to five years after stroke. After adjusting for health care needs there were no significant associations between socioeconomic status and health care utilisation. The observed figures, however, suggest that a lower socioeconomic status tended to increase admission to nursing homes and to decrease receiving care in non-institutional settings. CONCLUSIONS: Overall, inequalities in long term health outcomes were observed but solid indications for large inequalities in health care utilisation were not found. More investments in coordinated stroke services are needed to alleviate the unfavourable health situation of disadvantaged groups and to ensure that health care services respond appropriately to the health care needs of different socioeconomic groups.

A comparative study of dirithromycin and erythromycin in bacterial pneumonia.

Dirithromycin, a new once-daily macrolide, was studied in a multicentre, randomised, double-blind trial in community-acquired bacterial pneumonia. A total of 591 patients received either a single daily dose of dirithromycin, 500 mg, or erythromycin, 250 mg, four times daily. Clinical response rates were similar in both treatment groups (127 dirithromycin-treated and 118 erythromycin-treated patients): at the time of the final consultation, the clinical and bacteriological response rates for dirithromycin-treated patients were 94.5% and 93.0%, while for erythromycin-treated patients, they were 92.1% and 90.3%, respectively. The nature and frequency of treatment-emergent events were comparable. We conclude that dirithromycin, 500 mg, once daily, is safe and effective in the treatment of community-acquired bacterial pneumonia. The once daily dose is likely to improve compliance, making it preferable to erythromycin.

Brugada syndrome: in search of a genotype-phenotype relationship.

The Brugada syndrome (BS) is an autosomal dominant inherited cardiac disease characterized by an electrocardiogram (ECG) with a varying degree of ST-segment elevation in the right precordial leads, and (non-)specific conduction disorders. Patients often present with (aborted) sudden cardiac death due to ventricular tachy-arrhythmias. In a minority of patients, mutations in the gene encoding the cardiac sodium channel (SCN5A) can be found. The Brugada syndrome is therefore considered to be an ion channel disease. Genetic heterogeneity has been demonstrated but other causally related genes await identification. A genotype-phenotype relationship in Brugada syndrome as in the long QT syndrome was until recently unknown. The first step towards the establishment of such a relationship seems to be the recent observation of more prevalent conduction abnormalities in patients with an SCN5A mutation. Further establishment of a genotype-phenotype relationship in Brugada syndrome may simplify genetic screening, increase our basic understanding of the pathophysiology of this disease and make a more accurate discussion of the disease possible. In this paper we discuss the possible phenotypical features which may be expected to be determined by differences in genotype in Brugada syndrome.

A widening health gap in general practice? Socio-economic differences in morbidity between 1975 and 2000 in The Netherlands.

BACKGROUND: During the past two decades, socio-economic inequalities in health have been a major research theme in Western Europe. Research has shown that there are persistent differences in health between people with a high socio-economic status (SES) compared with people with a low SES. There are also indications for a widening health gap. The present paper aimed to find out whether this widening health gap exists in The Netherlands using morbidity data from a general practice (GP) registry. METHODS: Incidence data from a GP registry were used, involving over 12,000 patients. Morbidity data from 1975 to 2000 were grouped into 25 disease categories. SES was based on household occupational status. Poisson regression was used to determine the relationship between morbidity and SES and its changes over time. Separate analyses were performed for men and women. RESULTS: In most disease categories, a clear SES gradient disadvantageous to the lowest-SES group was identified: 17 out of 22 morbidity categories for men and 17 out of 24 for women. For seven (men) and eight (women) morbidity categories out of 17, the SES gradient increased between 1975 and 2000. CONCLUSIONS: This study provides new evidence for a widening gap in health between higher and lower SES in The Netherlands, using GP-defined disease data and a wide range of morbidity categories.

Prolactin levels and pituitary enlargement in hormone-treated male-to-female transsexuals.

PRL levels were evaluated during long-term treatment with cyproterone acetate 100 mg and ethinyloestradiol 100 micrograms/day orally or depot-oestrogens in 214 male-to-female transsexuals. PRL levels increased above normal in all subjects (normal less than 300 mU/l). In 46 (21.4%) subjects PRL levels rose to greater than 1000 mU/l. The incidence of PRL levels greater than 1000 mU/l was 3.7-7.2% per treatment year. Grossly elevated PRL levels were associated with high doses of oestrogens (P less than 0.05) and advanced age at the start of treatment (P less than 0.05). In 23 subjects PRL levels greater than 1000 mU/l decreased by more than 50% spontaneously (n = 5) or after dose reduction (n = 18). In five of the subgroup of 15 subjects with persistent PRL levels greater than 1000 mU/l enlargement of the pituitary gland was shown by CT-scanning. These data suggest that the lowest possible oestrogen dose and lifelong follow-up of hormone-treated male-to-female transsexuals is essential.

Metabolism of Styrene Oxide and 2-Phenylethanol in the Styrene-Degrading Xanthobacter Strain 124X.

Styrene oxide and 2-phenylethanol metabolism in the styrene-degrading Xanthobacter sp. strain 124X was shown to proceed via phenylacetaldehyde and phenylacetic acid. In cell extracts 2-phenylethanol was oxidized by a phenazine methosulfate-dependent enzyme, probably a pyrroloquinoline quinone enzyme. Xanthobacter sp. strain 124X also contains a novel enzymatic activity designated as styrene oxide isomerase. Styrene oxide isomerase catalyzes the isomerization of styrene oxide to phenylacetaldehyde. The enzyme was partially purified and shown to have a very high substrate specificity. Of the epoxides tested, styrene oxide was the only substrate transformed. The initial step in styrene metabolism in Xanthobacter sp. strain 124X is oxygen dependent and probably involves oxidation of the aromatic nucleus.