X-linked hypophosphatemia in adults: prevalence of skeletal radiographic and scintigraphic features

The radiologic studies of 38 essentially untreated adults with X-linked hypophosphatemia (XLH) were reviewed to determine the prevalence of radiologic features, to compare the findings in men and in women, and to elucidate the natural history of the disease by comparing the findings in young, intermediate-age, and older patients. Bone-reinforcement lines were common, but no characteristic mineral mass alteration was established. Looser zones were more prevalent in older subjects. Osteoarthritis was common, occurring in the ankles, knees, feet, sacroiliac joints, and wrists. Enthesopathy was infrequent in the younger group but was present in every member of the intermediate and older groups and was often accompanied by extra ossicles. Curvatures of the lower-extremity long bones were common in all age groups. Three new skeletal alterations in XLH were found to be common: flaring of the iliac wings, trapezoidal distal femoral condyles, and alterations in talar morphology, including shortening of the talar neck and flattening of the talar dome. Technetium-99m methylene diphosphonate scintigrams of 17 subjects were often abnormal, depicting bowing deformity and focal tracer accumulation in diaphyseal cortices and in periarticular and extraarticular regions. The mean metabolic index was moderately elevated (4.0). Both radiographic and scintigraphic findings were more severe in men, consistent with hemizygosity. The natural history of untreated XLH in both sexes is characterized by the development of a variety of age-related skeletal abnormalities during adulthood.     

Women worried about their familial breast cancer risk--a study on genetic advice in general practice

AIMS: To ascertain whether women who consulted their GP because they perceived themselves as at increased risk of familial breast cancer were indeed at increased risk, and to evaluate potential strategies for assessing genetic risk of breast cancer in general practice. METHODS: Sixty-seven out of 81 women who had consulted their GP for advice about their possible increased risk of developing breast cancer due to breast cancer in the family were interviewed. Familial breast cancer risk was assessed by a clinical geneticist. This assessment was compared with two recent guidelines for referral for genetic counselling. RESULTS: More than half (52%; n = 35) the women had a relative risk of two and over for developing breast cancer, while another half of these 35 (25%; n = 17) had a relative risk of three and over. All the women (n = 17) with a relative risk of three and over were identified by means of the two current guidelines for referral for genetic counselling, while more than half of the women (61%; n = 11) with a relative risk between two and three were identified. CONCLUSIONS: More than half the women concerned about their familial risk of breast cancer are indeed at increased risk of breast cancer. Current guidelines correctly identify women at high risk. However, doubts about the health gain and feasibility of referral warrant caution, and need further investigation.      

Mounting and calibration of stairs on piezoelectric force platforms

To calculate the centre of pressure using piezoelectric force plates mounted on pads, no net tensile stresses may be imposed on the surface of the plate. This condition is violated when stairs are attached to the plates, unless the plates are preloaded. Typical shear forces encountered when climbing stairs were used to determine required preloads of approximately 16.4 N/cm step height. Vertical and horizontal loads were applied at known locations on the steps, and points of application were calculated. Deviations were within ± 3 mm. The effect of point of application inaccuracy on calculated joint moments is considerable. A 2 cm medial shift in the point of application resulted in calculated peak knee abduction/adduction moment errors of 35%.     

Role of type A and type B monoamine oxidase in the metabolism of released [3H]dopamine from rat striatal slices

The effects of selective inhibition of multiple forms of monoamine oxidase (MAO) on the in vitro release and metabolism of newly-synthesized [³H]dopamine (DA) were examined using rat brain slices. Striatal slices were preincubated in the presence of [³H]l-tyrosine (20 μM) followed by a short incubation period in the presence of the selective irreversible MAO-inhibitor agents clorgyline (type A) and deprenyl (type B). Tissue pretreated in this manner was then subjected to a release incubation, and DA release and metabolism were determined under spontaneous and depolarizing conditions. Pretreatment with clorgyline (10^?7 M) significantly reduced the spontaneous, as well as K⁺-evoked, formation of both 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA). Deprenyl (10^?7 M) pretreatment did not significantly affect these variables, but clorgyline + deprenyl pretreatment resulted in a reduction of both DOPAC and HVA that was greater than that produced by clorgyline alone. By contrast, deprenyl pretreatment significantly decreased both DOPAC and HVA under depolarizing conditions, but only in the presence of the DA uptake inhibitor nomifensine (10^?5 M). In the absence of MAO inhibition, nomifensine increased K⁺-evoked formation of DOPAC and HVA, while spontaneous formation was not affected. The results suggest that released DA is deaminated primarily by the type A form of MAO; however, in the absence of the type A MAO, or under conditions that promote exclusive postsynaptic deamination, minor but significant metabolism occurs via the type B enzyme. Data obtained are further discussed in relation to the mechanism of MAO-inhibitor drug action and pre- versus postsynaptic formation of DOPAC and HVA.     

Hepatocellular carcinoma: assessment of resectability by computed tomography and ultrasound

A retrospective review of the CT and ultrasound scans from examinations of 30 patients who had hepatocellular carcinoma (hepatoma) was undertaken with special emphasis placed on evaluation of hepatic distribution of tumor, vascular invasion, and extrahepatic spread. Although both CT and ultrasound detected hepatoma in 29 of 30 patients (96%), CT showed more extensive hepatic parenchymal involvement in eight of the patients. Vascular invasion was seen more frequently with ultrasound than with CT. Invasion into the main portal vein was seen by ultrasound in 11 of 30 patients (37%). Extrahepatic spread of tumor was much more frequently detected by CT and was present in 21 of 30 patients (70%). A reasoned approach to the diagnostic workup of hepatomas that will minimize invasive procedures and unnecessary surgery is presented.     

Dopaminergic nature of feeding-induced behavioral stereotypies in stressed pigeons

Dopamine dependence of feeding-induced behavioral stereotypies (FIBS) was demonstrated by FIBS facilitation following chronic treatment with a dopamine (DA) agonist, apomorphine, and by FIBS inhibition following the administration of haloperidol, a DA antagonist. However, individuals that emitted FIBS were differentiated from those not emitting FIBS not by assayed telencephalic DA concentrations alone but by a higher stereotyping index (SI), a score positively related to the ratio of telencephalic DA-norepinephrine (NE) concentrations. These latter findings support the hypothesis of Antelman and Caggiula [3] which indicates that a catecholamine interaction in the brain serves to facilitate or inhibit some behavioral actions associated with stress.