Tmprss2 maintains epithelial barrier integrity and transepithelial sodium transport

The mouse cortical collecting duct cell line presents a tight epithelium with regulated ion and water transport. The epithelial sodium channel (ENaC) is localized in the apical membrane and constitutes the rate-limiting step for sodium entry, thereby enabling transepithelial transport of sodium ions. The membrane-bound serine protease Tmprss2 is co-expressed with the alpha subunit of ENaC. αENaC gene expression followed the Tmprss2 expression, and the absence of Tmprss2 resulted not only in down-regulation of αENaC gene and protein expression but also in abolished transepithelial sodium transport. In addition, RNA-sequencing analyses unveiled drastic down-regulation of the membrane-bound protease CAP3/St14, the epithelial adhesion molecule EpCAM, and the tight junction proteins claudin-7 and claudin-3 as also confirmed by immunohistochemistry. In summary, our data clearly demonstrate a dual role of Tmprss2 in maintaining not only ENaC-mediated transepithelial but also EpCAM/claudin-7-mediated paracellular barrier; the tight epithelium of the mouse renal mCCD cells becomes leaky. Our working model proposes that Tmprss2 acts via CAP3/St14 on EpCAM/claudin-7 tight junction complexes and through regulating transcription of αENaC on ENaC-mediated sodium transport.

[Changes in prescription patterns for peripheral and cerebral vasoactive drugs before and after establishing prescription standards in France]

OBJECTIVES

Assess changes in the number of prescriptions for peripheral and cerebral vasoactive drugs for the treatment of lower limb arteritis and cerebrovascular disease since the promulgation in 1995 of prescription standards for the treatment of lower limb arteritis. Assess compliance to prescription standards with a detailed analysis of patient features, prescriptions written for lower limb arteritis, cerebrovascular disease and concomitant diseases and evaluate changes in treatment costs for lower limb arteritis and cerebrovascular disease as well as cost of the full prescription, including treatments for associated diseases.

METHODS

This study was based on data recorded during the Permanent Study of Medical Prescriptions conducted from March 1994 to February 1995 and from March 1995 to February 1996 by the IMS. Prescription costs were established from the National Description Files of the IMS. Treatment costs were expressed as public price (FF) tax included. Prescriptions meeting the following criteria were selected for each period: prescriptions written by general practitioners for drugs with peripheral and cerebral vasoactivity (excepting calcium antagonists with a cerebral target) belonging to the Anatomic Therapeutic Classes C4A1 of the European Pharmaceutical Marketing Research Association, Bromly 1996; prescriptions for diagnoses 447.6 (arteritis) and 437.9 (cerebrovascular disease) according to the 9th WHO classification. A random sample of 500 prescriptions was selected to calculate costs.

RESULTS

Since the advent of the prescription standards in 1995, prescriptions have dropped off by 6.3% for lower limb arteritis and by 14.8% for cerebrovascular disease. There was a 3.7 point decline in the percentage of multiple prescriptions of vasoactive drugs for lower limb arteritis (21.7% prior to March 1995 versus 18% after promulgation of the prescription standards, p > 0.1) and a 1.8 increase in the percentage of multiple prescriptions for cerebrovascular disease (14% prior to March 1995 and 15.8% after promulgation of the prescription standards, p > 0.1). For the treatment of lower limb arteritis, prescription costs fell by a mean 9% per prescription and for the treatment of cerebrovascular disease they rose by a mean 7% per prescription. The price rise, due to multiple prescriptions of vasoactive drugs was 190 FF per prescription for lower limb arteritis and 104 FF per prescription for cerebrovascular disease.

CONCLUSION

Despite the retrospective nature of this study where confounding factors could not be controlled, our findings are in agreement with those reported earlier suggesting that cost containment policy implemented by the prescription standards has had little efficacy. In patients with arterial disease of the lower limbs, the percentage of prescriptions not complying with the recommended standards decreased by one-third to one-half over a 2-year period since the prescription standards were first announced in 1994.

[Can the results of large-scale clinical trials be applied to clinical practice?]

The management of a patient in cardiac failure should lead the physician to ask if the patient might benefit from treatment with an angiotensin converting inhibitor. Meta-analyses give a positive reply but often lack detail. Analysis of large scale therapeutic trials is the only way to determine whether the results are applicable in an individual case. This analysis starts with validation of the methodology (correct randomisation, respect of double blind protocol, identity of groups) and synthesis of results expressed, if possible, in absolute values. In a second stage, the criteria of inclusion, exclusion, and the comorbidity of enrolled patients, should be compared with those of the patient under consideration. In addition, the amplitude of the therapeutic benefit and the importance of undesired effects must be taken into account in the therapeutic decision. This approach allows a reasoned prescription based on documented facts.

Peripheral arterial obliterative disease. Cost of illness in France

The main purpose of this study, carried out in 1995, was to determine, using available sources, the cost of peripheral arterial obliterative disease (PAOD) in France over a 1-year period. This cost-of-illness study was based on a retrospective analysis of the available literature and databases. It involved a description of epidemiological data and a cost estimate of the different medical resources consumed over 1 year. For this latter purpose, a payer perspective was chosen. Data were extracted from national representative surveys and databases with respect to morbidity and mortality [from the National Institute of Health and Medical Research (Institut National de la Santé et de la Recherche Médicale; INSERM) and the National Sickness Insurance Fund for Salaried People (Caisse Nationale d'Assurance Maladie des Travailleurs Salariés; CNAMTS)], consultations, examination tests and drug prescriptions [from the French Medical Audit conducted by Intercontinental Medical Statistics (IMS)], hospitalisations [from the Statistical Unit of the Department of Health-Service des Statistiques, des Etudes et des Systemes d'Information (SESI) and the National Public Research Centre in Health Economics (Centre de Recherche d'Etude et de Documentation en Economie de la Santé; CREDES)] and related health expenditure from CNAMTS. In France, the prevalence of stage II PAOD (Leriche and Fontaine classification) in 1992 was estimated to be 675,000; 53% of these patients had undergone vascular or bypass surgery. The total annual cost of healthcare (including consultations, drugs, laboratory tests, hospitalisation and hydrotherapy) for the management of patients with PAOD ranged from 3.9 billion French francs (F) to F4.6 billion (1995 values), depending on the type of hospital considered. 50% of this cost was related to hospitalisations and 75% was covered by the CNAMTS. Although this study was only a partial evaluation and did not take into account indirect costs or nonmedical direct costs, such as transport and care by healthcare assistants and paramedics, these results may help to establish public health priorities and modify clinical practice to favour an earlier diagnosis of PAOD.

[Psychosocial management of retinitis pigmentosa patients from the viewpoint of the physician and the patient]

For patients with retinitis pigmentosa (RP), the disease means having to adapt and adjust continuously to their visual loss, i.e., repeatedly giving up everyday activities which they are no longer capable of performing. RP patients and those around them (parents, partner, children) face a lifetime of coming to terms with the disease and coping. The ophthalmologist is confronted with a patient to whom he can offer no therapy. Rather, once the diagnosis has been established, the patient must be assisted and advised according to the development of the disease, and given the necessary support. In other words, RP is a challenge not only for the patient, but also for the ophthalmologist.

[Toxoplasmic pleuro-pericarditis associated with Hodgkin's disease]

Pericarditis caused by toxoplasma infection is exceptional: 16 cases only have been published since 1943. The authors report a case of Hodgkin's disease associated with, and revealed by, toxoplasmic pleuro-pericarditis, and they review the literature on this complication of toxoplasmosis. Since the infection can be cured and since pericarditis may become chronic and constrictive if untreated, toxoplasmosis should be envisaged and confirmed or infirmed by serological tests in all patients presenting with pericarditis of uncertain origin. Provided it has not reached the chronic stage, toxoplasmic pericarditis responds well to the conventional treatment with pyrimethamine and sulfonamides.