The aim of this study was to examine the reliability of single-slice phase-contrast angiography (SSPCA) as a rapid technique for the investigation of suspected dural venous sinus occlusion. Images ...were obtained on 25 normal volunteers to document the accuracy of SSPCA in the demonstration of slow flow states. Normal volunteers were imaged using sagittal and coronal SSPCA (slice thickness 13 cm, matrix 256 x 256, TR 14 ms, TE 7 ms, flip angle 20 degrees, peak velocity encoding rate 30 cm/s). Sinus patency and flow rate were confirmed by measurement of flow in the superior sagittal and transverse sinuses using quantified single-slice phase difference images. Imaging was performed in 50 patients undergoing routine brain scans in order to determine the optimal slice orientation for clinical use. Twenty-one patients with suspected dural venous sinus thrombosis were also investigated with SSPCA and the diagnosis confirmed by one or more alternative imaging techniques. Imaging time was 29 s per acquisition and image quality was good in all cases. Variations in dural sinus patency and flow in normal volunteers were accurately predicted by SSPCA (kappa = 0.92). Use of a single angulated slice (130 mm thick, para-sagittal image angled 30 degrees towards coronal and 30 degrees towards transverse) provided sufficient separation of right- and left-sided venous structures to allow use of a single projection. The presence and extent of sinus occlusions in 14 patients and the absence of thrombosis in 7 were accurately identified by SSPCA. Sensitivity and specificity in this limited study were both 100%. The SSPCA technique takes less than 30 s and provides a reliable and rapid technique for the diagnosis of dural venous sinus thrombosis.
The anatomy of cadaveric lumbar apophyseal joints was examined as part of a study of possible correlations between lumbar apophyseal morphology, arthrosis, and cartilage thickness and stiffness.
To ...establish the morphometry of human upper lumbar apophyseal joints using an objective technique.
The apophyseal joints of 30 unfixed lumbar motion segments, all from different cadavers (24 male, five female, and one unknown, mean age 35 years, range 16-78 years) were exposed by dissection and disarticulation. Twenty-five motion segments were L1-L2, three were L2-L3, and two were L3-L4. The extent of fibrillation and linear dimensions of 29 of these specimens were examined, whereas the vertebrae and joints of 22 of them (18 being L1-L2) were cast in araldite resin.
The casts of the vertebrae were sectioned cephalocaudally at 1-mm intervals. Image processing of photographic slides of the sections established the orientations and dimensions of the lumbar apophyseal joints and their shapes using Fourier analysis.
Apophyseal joint surface area was 158 +/- 43 mm2, cephalocaudal length 15.2 +/- 2.7 mm, and straight line length between anterior and posterior borders was 13.2 +/- 1.9 mm. The joints were orientated at 62.5 +/- 11.8 degrees to the coronal plane. Average maximum depth of concavity was 1.8 +/- 0.7 mm. The posterior edges of two joint pairs twisted inward toward the midsagittal plane in a cephalocaudal direction; thus, some apophyseal joints bear part of the axial spinal load. The right inferior surfaces were more elongated cephalocaudally (but not longer) than their contralateral partners. Inferior apophyses were significantly more elongated cephalocaudally (but not longer) than their ipsilateral articulating superior surfaces.
In theory, Fourier analysis of joint surfaces was objective, but it dictated the criterion by which joints were grouped; care must be exercised so that measurement methods do not categorize joints artificially. "Symmetry" is too subjective to be applied to contralateral apophyseal joints; correlation coefficients should be quoted for areas and orientations. The morphology of contralateral lumbar apophyseal joint pairs was significantly correlated in all respects, as was the morphology of articulating lumbar apophyseal surfaces.
Patients with hypertrophic cardiomyopathy (HC) can experience exacerbation of exertional symptoms after a meal. The present study was designed to determine the prevalence and clinical correlates of ...postprandial symptom exacerbation (PPSE) in patients with HC. The records of 558 patients with HC and PPSE data who had undergone echocardiography at our institution from 2002 to 2006 were reviewed. Continuous-wave Doppler velocities were used to determine the left ventricular outflow tract gradient. Left ventricular filling was assessed using transmitral velocity curves. The Minnesota Living With Heart Failure questionnaire was administered to measure symptom limitations. A multivariate regression model was developed to determine the independent correlates with PPSE. Of the 558 patients whose records were reviewed, 189 (33.8%) had PPSE. The patients with PPSE were more likely to experience New York Heart Association class III/IV dyspnea or presyncope. PPSE was associated with greater resting outflow gradients and lower perceived quality of life. In conclusion, patients presenting with severe postprandial symptoms and reduced quality of life should be carefully evaluated for the presence of dynamic left ventricular outflow tract obstruction.
To determine whether benzodiazepine tranquilizers increase the risk of accidental injury requiring medical attention, we used pharmacy claims submitted to a large third-party payer to identify 4,554 ...persons who had been prescribed these agents and a matched control group of 13,662 persons who had been prescribed drugs other than benzodiazepines. We then used diagnoses recorded on claims submitted by medical care providers to identify all accident-related care received by these persons during three months before their first-observed prescription for a benzodiazepine or nonbenzodiazepine agent, respectively, and six months subsequently. We found accident-related care was more likely among persons who had been prescribed benzodiazepines; among these persons, the probability of an accident-related medical encounter was higher during months in which a prescription for a benzodiazepine had recently been filled compared to other months; and persons who had filled three or more prescriptions for these agents in the six months following initiation of therapy had a significantly higher risk of an accident-related medical event than those who had filled only one such prescription. Approximately two-fold risks of accident-related care were found, after controlling for age, sex, and prior utilization.
Quantum chemical calculations and experiments on model compounds are used to study the effect of conformational changes on intramolecular electron transfer in perylenebisimide–biphenyl dyads. The ...molecular orbital energy level of the biphenyl moiety and thus the free energy change for electron transfer depends on the dihedral angle between the two phenyl rings. Dramatic changes in the orbital energy levels result in very different electron transfer behavior for three model compounds. These changes are accurately predicted by calculations using density functional theory, which also give accurate results for geometries, suggesting such calculations can be useful in designing molecular electronic species.
The two iron-only hydrogenases (I and II) from Clostridium pasteurianum have been investigated by variable temperature magnetic circular dichroism (MCD) and electron paramagnetic resonance (EPR) ...spectroscopies. Samples were studied both reduced with dithionite under an atmosphere of H2 and after oxidation with thionine. The results are consistent with four and two 4Fe-4S1+,2+ (F)-clusters in hydrogenases I and II, respectively. All four F-clusters are reduced and paramagnetic in reduced hydrogenase I, with up to one exhibiting an S = 3/2 ground state and the remainder having conventional S = 1/2 ground states. Both F-clusters have S = 1/2 ground states in reduced hydrogenase II; however, one appears to be only partially reduced under the conditions used for reduction. MCD studies of the oxidized enzymes show no temperature-dependent features in the visible region which can be attributed to the EPR-active S = 1/2 hydrogen-activating cluster, suggesting predominantly oxygen and nitrogen coordination for the iron atoms of this center. However, temperature-dependent MCD transitions arising from a hitherto undetected S > 1/2 Fe-S clusters are apparent in both oxidized hydrogenases. Detailed EPR studies of oxidized hydrogenase I revealed resonances from an S = 3/2 species, however, spin quantitation reveals this to be a trace component that is unlikely to be responsible for the observed low temperature MCD spectrum. The nature and origin of these S > 1/2 Fe-S clusters are discussed in light of the available spectroscopic data for these and other iron-only hydrogenases.
High resolution ultrasonography was used to establish the presence of polycystic ovaries (PCO) in 50 women with symptoms of polycystic ovary syndrome and in 17 women with congenital adrenal ...hyperplasia. One hundred and thirty-seven post-menarcheal, premenopausal female members of the families of these patients were scanned to assess the heredity of the condition. Familial PCO was found in 56 of the 61 pedigrees (92%) in which sufficient members were available for study. The frequency of PCO in the relatives of the patients with congenital adrenal hyperplasia was no different from that found in the main group. Twenty-four out of thirty-six (67%) mothers of probands and 45 out of 52 (87%) sisters of probands were affected. The segregation ratio (fraction of females affected) for all sibships was 107 out of 133 (80.5%). The volumes of the polycystic ovaries (mean 9.97 ml, 95% confidence limits (CL) +/- 0.75) were significantly different from those of the normal ovaries (mean 5.38 ml, 95% CL +/- 0.26) (P less than 0.0001), although there was no significant difference between the volumes of the ovaries of the probands and those of their affected relatives. Even after allowing for a high frequency of PCO in the general population (22%), the observed segregation ratios were significantly different from those predicted for autosomal dominant (P less than 10(-4)) and X-linked dominant (P = 0.0002) modes of inheritance. A number of mechanisms which might account for the observed segregation ratio are considered. These include meiotic drive due to a genetic segregation distorted, vertical transmission of an infective agent, and environmental factors, such as the effect of maternal androgen on gonadal development.
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