[The safety of long-term administration of losartan in current clinical practice: a non-intervention NCT-CZ 14/04/LOZ study]. / Bezpecnost dlouhodobého podávání losartanu v bezné klinické praxi: neintervencní studie NCT-CZ 14/04/LOZ.

INTRODUCTION: Losartan is the longest used angiotensin II receptor blocker in clinical practice. It is one of the first-line drugs for the treatment of hypertensive disease and there is enough data available today about its use in the treatment of the disease, including some specific situations (left ventricular hypertrophy, cerebrovascular accidents) and cases when the hypertension disease combines with another disease (e.g. diabetic nephropathy). The primary objective of the non-intervention multicentre prospective observational open clinical assessment NCT-CZ 14/04/LOZ was to verify on a large sample of patients the safety of Lozap and Lozap H in current clinical practice. MATERIAL AND METHOD: The six-month clinical study enrolled patients with recently diagnosed hypertension and/or poorly controlled hypertension [blood pressure > or = 140/90 mm Hg: 4432 patients (96%); blood pressure: < or = 139/89 mm Hg 84 patients (2%); value unspecified: 83 patients (2%)]. A standard form was used for data acquisition. A total of 4,599 patients was enrolled (of which 2,386 women, i.e. 51.9%) with mean age 61 +/- 12 years (18-95 years; median 60 years) with additional risk factors (cardiovascular diseases in 48%, diabetes mellitus in 33%, lipid metabolism disorder in 42%, obesity in 45% and smoking in 26% of cases, respectively). 2,631 patients (57%) had previously diagnosed hypertension. The average blood pressure (BP) at enrolment in the study was 159/95mm Hg (median 160/95 mm Hg), and the average heart rate was 76 strokes/min (median 76). RESULTS: The most frequently used dose was 50 mg of losartan (Lozap or Lozap H)--in 4,006 patients (87%) at enrolment in the study and in 3,982 patients (87%) at the end of the study. Adverse effects related to the treatment during the study were reported in a total of 9 patients (0.2%). The therapy was assessed as well tolerated in 96% of patients (4,409), as fairly tolerated in 3% of patients (131) and as poorly tolerated in 0.1% of patients (4). Systolic and diastolic blood pressure decreased by 23mm Hg and 14mm Hg respectively to a mean value of 136/81 mm Hg (median 135/80mm Hg) (P < 0.001 for both systolic and diastolic BP). Improvement in patient status was recorded in 93% of cases (4,254 patients) and no change was recorded in 6% of cases (294 patients). CONCLUSION: Losartan in the form of Lozap or Lozap is a safe and effective treatment of patients with hypertensive disease. It is effective and safe beginning with the dose of 50 mg and its combination with a diuretic represents a good and safe therapy in patients with insufficient BP response to a 50 mg dose of losartan alone. In case of poor blood pressure response the dose has to be titrated to 100 mg.

[Effect of the Tabby mutation on the dentition of mice]. / Effets de la mutation Tabby sur la dentition chez la souris.

The X-linked hypohidrotic ectodermal dysplasia in man leads to dental defects and is homologous to the Tabby (Ta) mutation in mouse. We currently investigate the effects of the Ta mutation on odontogenesis. The incisor germ of Ta showed an abnormal size and shape, a change in the balance between prospective crown- and root-analogue tissues and retarded cytodifferentiation. Although the enamel organ in Ta incisors was smaller, a larger proportion of the dental papilla was covered by preameloblasts-ameloblasts. The independent development of the labial and lingual parts of the enamel organ in rodent lower incisor might reflect their heterogeneous origin, as demonstrated for the upper incisor. The mandibular cheek dentition in Ta mice exhibits large variations classified in five morphotypes, based on the tooth number, shape, size and position. In Ta embryos, the mesio-distal extent of the dental epithelium was similar to that in WT, but its segmentation was altered. These morphotypes could be explained by a tentative model suggesting that 1) the positions of tooth boundaries differ in Ta and WT molars and among the Ta morphotypes; 2) the tooth patterns are determined by the distal boundary of the most mesial tooth primordium while the distal teeth take advantage of the remaining dental epithelium; 3) one tooth primordium in Ta mice might derive from adjacent parts of two primordia in WT.

Different morphotypes of functional dentition in the lower molar region of tabby (EDA) mice.

OBJECTIVES: To sort and classify the highly variable lower molar dentition in tabby (Ta) mice postnatally. The Ta syndome is homologous to the anhidrotic (hypohidrotic) ectodermal dysplasia (EDA) in human and includes severe developmental defects of teeth, hair and sweat glands. DESIGN: Analysis of tooth shape and cusp pattern and measurement of the mesio-distal crown length. SETTING AND SAMPLE POPULATION: Institute of Experimental Medicine, Academy of Sciences, Prague. Fixed heads of 107 tabby (Ta) homozygous and hemizygous mice and 90 wild type mice aged from post-natal day 11 to adulthood, collected during 1995-2001. OUTCOME MEASURE: Identification of distinct morphotypes of Ta dentition. Reduced tooth length in Ta teeth and specific differences in tooth length between distinct morphotypes. RESULTS: The variable dentitions in the lower molar region of Ta mice were classified in two basic morphotypes I and II. The morphotype I was further subdivided into particular morphotypes Ia, Ib and Ic. Proportion of the basic morphotypes I and II was different in the offspring of heterozygous (84% and 12%) compared with homozygous + hemizygous (45% and 52%) mothers. The proportions of particular morphotypes within a basic morphotype were similar in both offspring groups. CONCLUSION: The identification of the distinct morphotypes made possible to classify the structural variability of the mandibular functional dentition in Ta mice.

Different morphotypes of the tabby (EDA) dentition in the mouse mandible result from a defect in the mesio-distal segmentation of dental epithelium.

OBJECTIVES: Prenatal identification of the different dentition morphotypes, which exist in the lower molar region of tabby (Ta) adult mice, and investigation of their origin. The mouse Ta syndrome and its counterpart anhidrotic (hypohidrotic) ectodermal dysplasia (EDA) in human are characterized by absence or hypoplasia of sweat glands, hair and teeth. DESIGN: Analysis of tooth morphogenesis using serial histological sections and 3D computer aided reconstructions of the dental epithelium in the cheek region of the mandible. SETTING AND SAMPLE POPULATION: Institute of Experimental Medicine, Academy of Sciences, Prague. Heads of 75 Ta homozygous and hemizygous mice and 40 wild type (WT) control mice aged from embryonic day (ED) 14.0-20.5 (newborns), harvested during 1995-2001. OUTCOME MEASURE: Prenatal identification of five distinct morphotypes of Ta dentition on the basis of differences in tooth number, size, shape, position and developmental stage and of the morphology of the enamel knot in the most mesial tooth primordium. RESULTS: The mesio-distal length of the dental epithelium was similar in the lower cheek region in Ta and WT mice. In Ta embryos, there was altered the mesio-distal segmentation of the dental epithelium giving rise to the individual tooth primordia. Prenatally, two basic morphotypes I and II and their particular subtypes (Ia, Ib, Ic, and IIa, IIb, respectively) of the developing dentition were identified from day 15.5. The incidence of the distinct morphotypes in the present sample did not differ from postnatal data. The proportion of the morphotype I and II was dependent on mother genotype. CONCLUSION: The different dentition morphotypes in Ta mice originate from a defect in the mesio-distal segmentation of the dental epithelium in mouse embryos. This defect presumably leads to variable positions of tooth boundaries that do not correspond to those of the WT molars. One tooth primordium of Ta mice might be derived from adjacent parts of two molar primordia in WT mice.

Crown morphology and pattern of odontoblast differentiation in lower molars of tabby mice.

The Tabby mutation leads to abnormal crown morphology in the developing molars. To identify cusps which were altered in number, size, and position in the first lower molars of mutant mice, we analyzed the patterning of odontoblast differentiation using morphological criteria on serial sections and 3D reconstructions. In wildtype mice, polarized and functional odontoblasts were first observed in the median L2 and B2 cusps, then in the distal cusps L3 and B3, and finally in L1, B1, and 4. In Tabby mice, terminal differentiation of odontoblasts was retarded by 24-36 hours compared with wild-type mice. Polarized odontoblasts first appeared in the most mesial part of the tooth and progressively extended distally. The mesial part of the M1 in Tabby fetuses may correspond to the L2, B2 area from wild-type mice. The ante-molar dental primordium observed in some samples would thus represent remnants of cusps L1 and B1.