Ullrich-Turner syndrome with a small ring X chromosome and presence of mental retardation

Since some patients with Ullrich-Turner syndrome (UTS) have mental retardation, we reviewed our experience to look for a high-risk subgroup. Among 190 UTS and gonadal dysgenesis patients with X chromosome abnormalities, 12 had mental retardation. All of the six (100%) with a small ring X were educable (EMI) or trainable mentally impaired (TMI) with more severe delay than expected in UTS. Among the 184 with other X abnormalities, only 6 had similar delays (2 from postnatal catastrophes), for a frequency of 3.3% mental retardation among those without a small ring X; only 2.2% of these had unexplained mental retardation. Polymerase chain reaction studies showed no Y-derived material in the 2 patients who were evaluated, and in situ hybridization confirmed X origin of the ring in the 6 subjects who were evaluated. We describe the phenotype of the 6 individuals with a small ring X, and an additional 2 patients with a small ring X who were identified outside the survey. The subjects with a small ring X comprised a clinically distinct subgroup which had EMI/TMI and shorter stature than expected in UTS. Seizures and a head circumference <10th centile were observed in half of the patients with a small ring X, and strabismus, epicanthus, and single palmar creases were present in more than half. A “triangular” face in childhood, pigmentary dysplasia, sacral dimple, and heart defects were also common. Neck webbing appeared to be less frequent than in 45, X. We hypothesize that the high risk of mental retardation in this form of the UTS results from lack of lyonization of the ring X due to loss of the X inactivation center. Excluding those with a small ring X, mental retardation is not significantly increased in patients with UTS. © 1992 Wiley-Liss, Inc.     

Ultimate tensile strength of dentin: Evidence for a damage mechanics approach to dentin failure

Dentin structure and properties are known to vary with orientation and location. The present study explored the variation in the ultimate tensile strength (UTS) of dentin with location in the tooth. Hourglass specimens were prepared from dentin located in the center, under cusps, and in the cervical regions of human molar teeth. These were tested in tension at various distances from the pulp. Median tensile strengths ranged from 44.4 MPa in the inner dentin near the pulp, to 97.8 MPa near the dentino-enamel junction (DEJ). This increase in the median UTS with distance from the pulp to the DEJ was statistically significant (P <.001). Of particular importance was the observation that the UTS measurements followed a Weibull probability distribution, with a Weibull modulus of about 4.5. The Weibull behavior of the UTS data strongly suggests that the large variances in fracture strength data result from a distribution of preexisting defects in the dentin. These findings justify a damage-mechanics approach to studies of dentin failure.     

Concentrating stroke care provision in the Czech Republic: The establishment of Stroke Centres in 2011 has led to improved outcomes

This article describes policy processes that have led to the re-organisation of stroke care in the Czech Republic since 2011, which has been part of a broader process of care concentration in several medical fields. Currently, stroke care is provided by 13 Comprehensive and 32 Primary Stroke Centres. The paper explains factors that supported the reform implementation, reviews implications, and discusses future challenges.Mandatory reporting of quality indicators, the introduction of a benchmarking system, integration with pre-hospital emergency care, and the introduction of countrywide patient triage have supported more timely treatment for stroke patients and better quality of care. Data from the Stroke Care Quality Indicators of the Czech Stroke Society show positive trends in many areas: the number of patients treated with intravenous thrombolysis quadrupled in eight years, with 26.4 % of all acute stroke patients receiving thrombolysis in 2018. Czech Republic now ranks third in Europe in the number of thrombolysis per population and second in the number of mechanical thrombectomies per population. The Czech experience provides an example of positive outcomes of concentrated stroke care, while highlighting the importance of proper implementation processes. In particular, it is essential to involve stakeholders and to provide reputational incentives through continuous benchmarking.     

Phalloarteriography in the diagnosis of erectile impotence

An angiographic method has been developed for x-ray visualization of the arteries supplying the cavernous bodies of the penis, namely, the internal iliac, internal pudendal, and penile artery and its branches (dorsal, deep, and bulbocavernous arteries). Under normal conditions the technique makes pulsations in both dorsal penile arteries palpable, and the flow rate of fluid into the cavernous bodies necessary to produce and maintain erection can be determined. The principle of the method involves artificial passive erection or semierection, during which we perform selective or semiselective arteriography of the bed supplied by the internal iliac artery, or retrograde arteriography by puncture of the dorsal artery of the penis. Thirty males complaining of more than 1 year of impotence (including 12 diabetics) were investigated, 29 by our standard technique and 1 by translumbar pelvic arteriography with retrograde arteriography of the dorsal penile artery. All patients showed severe stenosis or obliteration of the vessels supplying the cavernous bodies. There was agreement between absence of pulsation in the dorsal penile arteries and the angiographic findings. Flow rates necessary to produce erection varied from 45 to 160 ml/min, with a mean of 90 ml/min. For controls, angiographic studies were performed in 4 men with clearly psychogenic impotence, all of whom were found to have normal-appearing arteries supplying the cavernous bodies. On the basis of these findings and previously reported histological investigations, we believe that most impotence is the symptomatic and functional result of arterial disease. The arteriographic technique described allows a precise anatomical diagnosis to be made, and can indicate surgical and microsurgical correction.

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Résumé Nous avons mis au point une technique d'angiographic qui visualise la vascularisatioh artérielle des corps caverneux, soit les artères iliaques internes, honteuses internes, péniennes et leurs branches dorsales, profondes et bulbocaverneuses. Dans les conditions normales, la technique permet de palper le pouls dans les artères dorsales de la verge et de mesurer, dans les corps caverneux, le débit nécessaire pour produire et maintenir une érection. Le principe de la méthode repose sur une érection ou semi-érection artificielle passive associée, soit à une artériographie sélective ou semi-sélective du territoire de l'iliaque interne, soit à une artériographie rétrograde par ponction de l'artère dorsale de la verge.Trente hommes (dont 12 diabétiques) ont été étudiés: ils présentaient tous une impuissance depuis plus d'un an. L'investigation a été faite, dans 29 cas avec notre technique standard, dans un cas par aortographie translombaire et arteriographie rétrograde de l'artère dorsale de la verge. Il existait dans tous les cas des sténoses serrées ou des oblitérations de l'arbre artériel allant aux corps caverneux. Les lésions mises en évidence par l'artériographie concordaient avec l'absence de pulsations dans les artères dorsales de la verge. Les débits nécessaires pour produire l'érection ont varié entre 45 et 160 ml/min, avec une moyenne de 90 ml/min. A titre de contrôle, des artériographies ont été faites chez 4 hommes atteints d'impuissance manifestement psychogène: chez tous, l'irrigation artérielle des corps caverneux était normale.Ces résultats, et des études histologiques antérieures, nous amènent à penser que, dans la plupart des cas, l'impuissance est la manifestation symptomatique et fonctionnelle d'une maladie artérielle. La technique d'angiographic que nous avons décrite donne un diagnostic anatomique précis et permet de poser les indications de la chirurgie ou de la microchirurgie correctrice.

     

Fibrous hamartoma of infancy. A study of eight cases with immunohistochemical and electron microscopical findings.

Eight cases of fibrous hamartomas of infancy are presented. Actin positivity and desmin negativity in collagen forming spindle-shaped cells and electron microscopical findings point to the myofibroblastic nature of this entity. "Dark cells" which spread regularly in all but one of our tumors were immunohistochemically determined to be a mixture of B and T cell lymphocytes. Their selective location and possible role are discussed.     

The renal cytochrome P-450 arachidonic acid system

In addition to cyclooxygenase and lipoxygenase, arachidonic acid (AA) is metabolized by the cytochrome P-450 monooxygenase system. The kidney is one of the major extrahepatic tissues that display cytochrome P-450 enzyme activities, in particular the cortex, specifically the proximal tubule demonstrate the highest concentration. AA is metabolized by the renal cytochrome P-450 epoxygenase and /-1 hydroxylases to epoxyeicosatrienoic acids and /-1 alcohols (20- and 19-mono-hydroxyeicosatetraenoic acids), respectively. These metabolites possess a broad spectrum of biological and renal effects which include: vasodilation, vasoconstriction, inhibition and stimulation of Na⁺–K⁺-ATPase, inhibition of ion transport mechanisms, natriuresis, inhibition of renin release and stimulation of cell growth. These metabolites are endogenous constituents of the kidney and are present in urine with increasing concentration under pathological conditions such as pregnancy-induced hypertension. The cytochrome P-450-dependent metabolism of AA is specifically localized to the proximal tubule and exhibits developmental changes, i.e., renal production of metabolites is very low in the fetus, newborn and up to 3 weeks of age, after which a remarkable increase in enzyme activities is observed. These characteristics call attention to the importance of this enzyme system in producing cellular mediators for regulating renal function in normal and diseased states.     

Predictors of cervical coinfection with multiple human papillomavirus types.

Women infected with multiple human papillomavirus (HPV) types seem to be at higher risk of cervical intraepithelial neoplasia, although there is controversy about whether coinfections are associated with lower or higher grades of dysplasia. There is no established risk factor profile for infection with multiple HPV types. We analyzed data from a prospective cohort of 2,075 Brazilian women to identify determinants of HPV coinfection. Cervical specimens were collected for cytology and HPV DNA detection. Data on baseline and time-dependent putative risk factors were obtained by interview. Baseline predictors of HPV coinfection included younger age, greater number of recent sexual partners, a history of condyloma but not of other sexually transmitted diseases, and younger age at first sexual intercourse. In repeated measures analyses, there was a weak positive association between the number of sexual partners in the time interval between two study visits and the risk of coinfection. Our results suggest that the risk factor profile for HPV coinfection among HPV-infected women shares several similarities with risk factors for any HPV infection.