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Biomedical subjects

B Urban

Publications and source records attributed to B Urban.

31 records · Page 2Linked to original sources
PubMed1994

Spiral CT of the liver: current applications.

Spiral CT allows rapid imaging of the liver resulting in improved contrast dynamics compared with conventional CT techniques. Improved lesion detection has been shown with spiral CT by using overlapping reconstruction intervals and by eliminating respiratory misregistration. Vascular and parenchymal abnormalities, including portal venous thrombosis or cirrhosis with development of collateral vessels, are readily appreciated using spiral technique. Combining spiral CT and portography enhances lesion detection by maintaining high levels of hepatic contrast enhancement for the duration of the liver scan.

Humans↗
PubMed1993

Complement resistance of pathogenic Entamoeba histolytica mediated by trypsin-sensitive surface component(s).

Pathogenic forms of the protozoan parasite Entamoeba histolytica were reported previously to resist the cytolytic effect of the alternative complement pathway (AP) only temporarily during exposure to complement. In contrast, nonpathogenic forms of E. histolytica had been found to show AP resistance as a stable property. We studied the mechanisms of AP resistance of the two forms. Upon exposure to AP activity, resistant pathogenic or nonpathogenic forms bound significantly less C3 products than complement-sensitive pathogenic amebae, indicating that the two resistant forms both inhibited AP amplification. Various enzymatic treatments and inhibition of membrane mobility by cytochalasin B and glutaraldehyde fixation showed that the mechanisms of AP inhibition differed between pathogenic and nonpathogenic forms; in contrast to nonpathogenic forms, pathogenic amebae required intact membrane mobility and a trypsin-sensitive surface component(s) to inhibit AP activation.

Animals↗
PubMed1988

Subtypes of depression in patients with chronic pain.

Recent studies have shown that depression can be assessed in patients who have chronic pain. This study shows that various subtypes of depression can be differentiated in such patients using a standardized diagnostic schema for psychiatric disorders and a self-rating instrument for assessing the level of psychologic distress. In addition, when examining the onset of pain and subtypes of depression, there was no correlation between the onset of major depression and pain, whereas there was a strong positive correlation between the onset of chronic depression and pain. The recognition of the subtypes of depression has clinical implications in the management of the patient with chronic pain and depression.

Adult↗
PubMed1988

Involuntary movements of the lower extremity following dorsal root entry zone lesions in a man treated for phantom limb pain.

A patient developed continuous patterned involuntary movements of abduction-adduction, flexion-extension of his right lower extremity following surgical placement of spinal dorsal root entry zone lesions for the treatment of phantom limb pain. The stereotype movements were monitored by video and electromyographic recording of quadriceps femoris and hamstring muscles. Administration of para-chlorophenylbutyric acid (baclofen) dramatically stopped the involuntary movements and electromyographic silence ensued. Voluntary muscle movements were preserved. The theoretical implications of this unique movement disorder and central patterning of motor activity within the spinal cord are discussed.

Baclofen↗
PubMed1987

Chromosome 18 aneuploidy: anatomical variations observed in cases of full and mosaic trisomy 18 and a case of deletion of the short arm of chromosome 18.

Cases of full and mosaic trisomy 18 and a body of an infant with the 18p-syndrome were dissected in detail to compare the anatomical variations associated with these 3 chromosome imbalances involving autosome 18. The types and numbers of morphologic variations present in both the full and mosaic trisomy 18 bodies were similar to the types and numbers of variations seen in all other cases of full trisomy 18 that have been studied by gross dissection. Apart from an atrial septal defect, the body of the infant with the 18p- imbalance showed only 2 striking defects: 1) deficiencies of the levator palpebrae superioris muscle of the upper eyelid, and 2) absence of the ligament of the head of the femur. The first variation provides a morphologic basis to explain the ptosis which is observed frequently in affected individuals. Absence of the ligament of the head of the femur may be a factor contributing to congenital dislocation of the hip, which is reported occasionally in affected individuals. In addition to providing more detailed information about the phenotype of individual aneuploidy syndromes, studies of cases of different imbalances of single autosomes may provide additional insights about the genotype/phenotype relationships of specific chromosome segments.

Brachial Plexus↗
PubMedDate not supplied

Identification of the aberrant hepatic artery with axial spiral CT.

PURPOSE: To determine whether axial spiral computed tomography (CT) allows detection of the replaced hepatic artery as part of preoperative planning for pancreatic tumor resection. MATERIALS AND METHODS: Axial spiral CT scans (8-mm section thickness, 4-mm overlapping reconstructions) were obtained in 50 patients with periampullary tumor and were examined by three radiologists. Readers' interpretations were compared with angiographic results. RESULTS: Eight patients had an aberrant hepatic artery. Two of the three readers detected or suspected all of these abnormalities (100% sensitivity), and one reader identified seven of eight aberrant arteries (88% sensitivity). However, readers requested angiographic confirmation in 14 of 24 tests. Sensitivity, specificity, and accuracy were 96%, 87%, and 88%, respectively, for all readers. CONCLUSION: Axial spiral CT may simplify preoperative evaluation of periampullary tumors. However, angiographic support was necessary in most cases in this study. Improvements in CT techniques may eventually allow spiral CT to replace angiography in the examination of these patients.

Ampulla of Vater↗
PubMedDate not supplied

Ultrastructural changes in the trabecular meshwork of congenital glaucoma.

Trabeculectomy specimens from 10 patients with congenital glaucoma were studied by electron microscopy. In all cases proliferation of fibrous connective tissue was found from the inner wall of Schlemm's canal. Accumulation of collagen fibres, sometimes of varied thickness and irregular striation, and agglomerations of microfibrillar material with the structure of collagen microfibrils were observed. This material formed basement membrane-like structures and 'shaggy' or fingerprint-like patterns. The ultrastructural examination of the trabecular meshwork revealed no significant differences between the morphological picture of primary congenital glaucoma and that found in Axenfeld and Rieger anomalies. Ultrastructural pictures of glaucoma cases examined in the present study converged also with those of juvenile glaucoma cases reported in literature, which may indicate the existence of a pathogenic factor common to these forms of glaucoma.

Female↗
PubMedDate not supplied

[Secondary intraocular lens implantation in aphakic eyes].

PURPOSE: Presentation of the results of secondary IOLs implantations in 35 aphakic patients operated on from January 1989 to June 1994 (in the years 1989-1994, first half). MATERIAL AND METHODS: Of 20 men and 15 women, in 17 patients cataract was removed by phacotomy, in 18-by intracapsular cryoextraction. Secondary anterior IOL implantation was performed 1 month--20 years after cataract surgery. The power of the lenses ranged from +17.0D to +23.5D and was calculated basing on the measurement of eyeball length and corneal refraction. RESULTS: Early complications found in 9 patients after surgery included: shallow anterior chamber in 2, anterior chamber haemorrhage in 1, iris "bombee" in 1, iritis in 1, united suteres in 2, corneal erosion in 1 and choroidal detachment in 1 eye. These symptoms declined one week after conservative treatment. In 2 patients, additional corneal suteres were inserted. One month after surgery, in all patients, visual acuity was 5/10-5/5. In 5 eyes, slight decentralisation of the pupil was observed.

Adult↗