Intracranial arterial dolichoectasia in autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a systemic disorder with a variety of cardiovascular manifestations. This study presents a group of patients with ADPKD who had intracranial arterial dolichoectasia. One hundred seventy-eight ADPKD patients were screened with magnetic resonance angiography, 40 ADPKD patients had conventional angiography, and 98 ADPKD patients underwent a brain autopsy. For comparison, 360 patients without ADPKD who had magnetic resonance angiography and conventional angiography or brain autopsy were also studied. The prevalence of asymptomatic intracranial arterial dolichoectasia was 2.2% (4 of 178), 2.5% (1 of 40), and 2.0% (2 of 98) in the three ADPKD groups, respectively. None of the patients without ADPKD had intracranial arterial dolichoectasia. In addition to the seven patients with asymptomatic disease, two ADPKD patients with vertebrobasilar dolichoectasia had posterior circulation ischemic symptoms. The mean age of the nine patients (five men and four women) was 56.6 yr (range, 41 to 67 yr). The posterior circulation was involved in five patients, the anterior circulation was involved in two patients, and both were involved in two patients. Arterial dissection was believed to have caused middle cerebral artery dolichoectasia in one patient, and intracranial arterial dissections were strongly suspected in two other patients. Six of the nine patients with intracranial arterial dolichoectasia had additional vascular manifestations of ADPKD. Some patients with ADPKD are at an increased risk of developing intracranial arterial dolichoectasia and dissections. Recognizing this association is important because (1) it may be a cause of stroke; (2) it may mimic a saccular aneurysm on radiographic studies; and (3) it suggests that the arteriopathy of ADPKD may be more generalized than previously believed.     

Linkage mapping of fifty-eight new rat microsatellite markers

Fifty-eight new anonymous simple sequence repeats (SSR) were generated and mapped to various rat chromosomes. Among them two genes (rat homologs for human cadherin-14 and mouse fibroblast growth factor-related protein) were mapped on Chromosomes (Chrs) 2 and 11 respectively. The majority of markers were generated from a small insert genomic library specific to Chr 11, 13, 14, and 15. Twenty new markers were mapped to Chr 13, which is known to contain a blood pressure quantitative trait locus (QTL). Several approaches to obtain microsatellite markers are described. The protocols and newly generated markers should be useful for ongoing rat genome project.     

Purification of alcohol dehydrogenase from four genotypes of the olive fruit fly Bactrocera (Dacus) oleae

Two forms of a sampling theorem for concentric circles are established for a bandlimited two-dimensional (2-D) function. The location of the samples is prescribed either on equidistant circles or on the roots of the Bessel function J0( ). Both methods give comparable results, however, the number of samples required for their numerical evaluation is significantly less for the root-sampling formulation.     

Forms of extraction of silicon compounds in rice husks

The forms of extraction of silicon compounds in rice husk, proposed as a source of silicon dioxide, were examined. A model in which the silica particles distributed in the plant cells of rice husk are separated by organic layers from mineralizer impurities was proposed. Crystallization of silicon dioxide begins after elimination of the layers of carbon formed at the site.     

Stability of austenite in chrome-nickel stainless steel and susceptibility to corrosion cracking

Conclusions The susceptibility to corrosion cracking of austenitic chromium-nickel steels does not depend on the occurrence of the transformation in the process of deformation.Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 3, pp. 73–75, March, 1967.     

A method for calculating the tangent on the basis of the Hough transform

A method for calculating the tangent direction for a digital curve on the basis of the Hough transform is proposed. The initial data for the Hough transform are taken from tables of angular intervals obtained from a catalog of digital curves. Such a catalog is constructed for a chosen size of the local window on the basis of a specially developed indexation of curves. When determining the intervals of tangent directions for the catalog of curves, several methods of parameterization are used: straight line, elliptic or sinusoidal arc, and superposition of harmonics. The curve selection criterion is the maximum curvature of the corresponding smooth parametric curves. This makes it possible to adapt the method to a class of initial curves. Comparison with earlier-developed methods has demonstrated a significant increase in accuracy, especially with an increase in the curvature.     

The renal factor in the post-traumatic "fluid overload" syndrome

Hypervolemia with hypertension often occurs 36-72 hours following massive blood and fluid replacement for hypovolemic shock. This syndrome of "fluid overload" has been attributed to the rapid intravascular flux of previously sequestered fluid in patients with impaired diuresis. This hypothesis was tested in 35 injured patients who received a mean of 9.3 L of blood and 17.4 L of salt during resucitation. The renal parameters measured soon after resuscitation included: 1) renal clearance of inulin (GFR), para-amino hippurate (ERPF), milliosmoles, sodium, and free water; 2) inulin space, renal vascular resistance (RVR), O2 consumption, renin, renal blood flow (RBF), and response to furosemide. Eighteen patients developed hypertension, hypervolemia, and respiratory insufficiency. When compared to the 17 normovolemic, non-hypertensive patients, the 18 hypervolemic patients had significantly increased RVR, with a significant decrease in RBF despite an increase in plasma volume and cardiac output. Furosemide produced less diuresis and natriuresis in the hypertensive patients. The balance between hypovolemia and "fluid overload" seemed percarious in the hypertensive patients. Peripheral renin and catecholamine levels were normal in both groups. Patients with post-traumatic "fluid overload" appear to have a combination of hypervolemia, respiratory insufficiency, hypertension, increased cardiac output, decreased extracellular fluid space, and decreased renal perfusion. These findings suggest that decreased interstitial fluid space compliance rather than "fluid overload" is the underlying factor leading to respiratory insufficiency. The therapeutic aspects of these findings are discussed.