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Biomedical subjects

J Neuwirth

Publications and source records attributed to J Neuwirth.

At least 37 records · Page 2Linked to original sources
PubMed1990

[Anomalies of the basilar and vertebral arteries that are of practical importance].

Anomalies of vertebrobasilar vessels arise as early embryonal developmental deteriorations. The majority of them concerns the position, origin and shape of the vertebral and/or basilar arteries. In three patients, reported here, the aberrations were found occasionally and contributed in no way to the clinical symptomatology. In the first patient, a fenestration of A. basilaris was found with a fork-like division on its periphery. In the second patient we noted a doubled proximal origin of the vertebral artery. One artery arose from A. subclavia sinistra, the second one from the aortic arch. Both joined thereafter the common vertebral stem at the level of C4. In the third patient, A. vertebralis originated from the aortal arch, and, at the level of the thyroid, A. thyreoidea inferior originated from it. Attention is drawn to the practical importance of such variations as a possible source of diagnostic errors during cerebral arteriography.

Adult↗
PubMed1990

[Digital subtraction angiography in intracranial vascular malformations].

From a total number of 350 DSA examinations in the cervicocranial region intracranial vascular malformations were detected in 14 patients, i.e. in 4%. In six instances an aneurysm was involved, six times arteriovenous and twice a venous malformation. Using digital subtraction angiography, it is usually possible to diagnose by the intravenous or intraaortal route major findings, however, in the majority the finding serves only for orientation. For a more detailed diagnosis, in particular of small findings and findings before operation, a selective examination is more suitable.

Adult↗
PubMed1989

[The significance of digital subtraction angiography in diseases of the lungs and mediastinum].

The authors present their first experience with lung DSA in a group of 75 patients. The examination was most frequently performed by instilling a contrast medium into central, less frequently into peripheral veins. The most frequent indications included tumorous lung diseases and mediastinal tumours before an operation treatment, a suspected pulmonary embolism, lung and vascular malformation. Intravenous DSA proved to be also useful in the evaluation of pathological changes of thoracic aorta.

Adolescent↗
PubMed1989

[Dilatation technic in esophageal stenoses using a balloon catheter].

In dilating oesophageal stenoses by balloon catheters it becomes necessary to adapt the technique of the intervention to the type and degree of stenosis and condition of the patient. The dilatation may be successfully performed even in very narrow postinflammation, postoperation and postcorrosion stenoses. The dilatation is usually performed for the period of 30 minutes, the shortest period between interventions being twice in a week, being followed by weekly or several weeks intervals. In a careful application of the balloon catheters transnasally or transorally it becomes possible to decrease the unpleasant feelings of the patient and possible complications to a minimum.

Catheterization↗
PubMed1987

Titanium retinal tacks with pneumatic insertion. Histologic evaluation in rabbits.

Titanium retinal tacks were implanted through the formed vitreous into the posterior retinas of rabbits and evaluated by electroretinographic testing and by light microscopy at intervals after implantation. Tritiated thymidine autoradiography was used to evaluate the proliferation of ocular tissues in response to tack insertion. Within one month after implantation, the retinal tacks were surrounded by scar tissue produced by the proliferation of retinal glial cells and choroidal and scleral connective tissue cells. The tissue response was focal and there was no excessive fibrous tissue or vascular proliferation or any indication of iris neovascularization for six months. The observations of firm retinal adherence and low tissue reactivity suggest that titanium tacks can be used to secure the retina during retinal attachment surgery and can remain permanently in the eye.

Animals↗
PubMed1986

Clinical results of titanium retinal tacks with pneumatic insertion.

We used titanium retinal tacks inserted with a pneumatic instrument for retinal fixation in 11 operative procedures in ten eyes with complicated retinal detachments. Titanium was selected for permanent implantation because of its documented biologic tolerance. No intraoperative or postoperative complications related to the tacks were encountered. Three tacks, one 0.7 mm in length and two 1.6 mm in length, became dislodged postoperatively; 50 permanently implanted tacks, each 1.6 mm in length, remained in place after a mean follow-up of five months. Retinal reattachment at the end of the follow-up period was achieved in eight eyes and useful visual function was obtained in three eyes. Titanium retinal tacks are useful when immediate retinal fixation is required either temporarily or permanently to prevent retraction and detachment of the retina until adjunctive diathermy, cryopexy, or photocoagulation becomes effective.

Adult↗
PubMed1985

Clinicopathologic results of vitreous surgery for epiretinal membranes in patients with combined retinal and retinal pigment epithelial hamartomas.

Two patients (a 44-year-old woman and a 26-year-old man) with progressive visual loss associated with macular combined retinal-retinal pigment epithelial hamartomas underwent pars plana vitrectomies with peeling of macular epiretinal membranes. Histopathologic findings for one of the membranes were similar to those in idiopathic or other secondary epiretinal membranes. Although the epiretinal membranes were satisfactorily removed, visual acuity improved in neither eye. Fluorescein angiography showed persistence of vascular tortuosity and leakage and cystoid macular edema after surgery in both cases. One eye developed a late postoperative operculated retinal tear which was successfully treated with cryopexy. The role of vitrectomy and membrane removal in cases of macular combined retinal-retinal pigment epithelial hamartomas appears to be limited.

Adult↗
PubMed1985

Computer-assisted spectral electroretinography in vitrectomy patients.

Computer-assisted spectral electroretinography (CASE), using full field stimulation in the presence of a rod saturating background light, has been found to be a useful means of evaluating retinal function in patients with vitreal opacities. By this means, cone electroretinograms (ERGs) to white as well as spectrally selective stimuli could easily be detected in 22 of 24 eyes with vitreal opacities obscuring any view of the fundus and with minimal or no detectable ERGs to standard single flash stimuli. The responses to spectral stimuli in the presence of a rod saturating background light provides a means of estimating the optical density of the opacity. The results indicate that most patients undergoing vitrectomy for such opacities have considerable superimposed retinal damage and that the opacities themselves are seldom sufficiently dense to decrease the ERG to any great extent. Five eyes studied before and after vitrectomy indicate that successful vitrectomy has no effect on the ERG. The results suggest that CASE may be a useful substitute to the bright flash ERG for evaluating global retinal function behind an opaque media.

Adolescent↗
PubMed1982

Cytomegalovirus retinitis in a young homosexual male with acquired immunodeficiency.

A case is reported of histopathologically documented CMV retinitis. It is part of a recently appreciated syndrome in young homosexual men, in which cellular immune deficiency has been documented and in which CMV infection may play a role. This case demonstrates that CMV retinitis is not excluded by negative CMV serology or cultures.

Acquired Immunodeficiency Syndrome↗
PubMed1978

Effects of total fasting in obese women. II. Acid-base balance.

Acetoacetate, beta-hydroxybutyrate, pyruvate and lactate in whole blood, the acid-base balance according to Astrup, SGOT and SGPT, and the serum and urinary sodium and potassium were estimated in 10 fasting obese women. Fasting led metabolic acidosis due to a tenfold increase of acetoacetate and beta-hydroxybutyrate, while pyruvate and lactate had a tendency to decrease. Serum and urinary sodium and potassium decreased; A tendency to increased SGOT and SGPT was observed. Sodium bicarbonate administered in general since the 8th or 9th day of fasting led in 4 to 5 days to an earlier correction of blood pH, while pCO2, actual HCO3, standard HCO3, base excess, buffer base, pO2, Hb saturation and total CO2 reached the prefasting values only several days after blood pH normalisation. The administration of NaHCO3 corrected the serum level of sodium while its excretion remained low. Bicarbonate had no influence on the decreasing trend of serum potassium, but the urinary output of potassium was stabilized. It is suggested that in fasting subjects 1. the correction of the metabolic acidosis by NaHCO3 does not reduce the rate of lipid catabolism and does not lead to fluid retention and 2. liver damage in fasting may be prevented by blood pH normalisation.

Acetoacetates↗
PubMed1978

Peripheral conversion and uptake of androgens in a XXY-man with Klinefelter's syndrome.

The conversion of 3H-testosterone and the uptake of 3H-testosterone and 3H-5alpha-dihydrotestosterone were investigated in pubic skin and pubic hair follicles of a XXY-man with inadequate pubic hair. The uptake of both androgens was demonstrated in the skin as well as in the hair follicles. Similarly the activity of steroid 5alpha-reductase was present in both tissues. The total conversion of 3H-testosterone was 2-3 times higher in the patient than in control persons. In the XXY-man the major metabolites were 5alpha- and 5beta-androstanediols, whereas in the normal men 5alpha-dihydrotestosterone and 4-androstenedione were mainly formed from testosterone. An explanation of the inadequate growth of pubic hair in our patient seems to be related to a conversion of testosterone - at its low plasma level - to its relatively inactive metabolites.

Adult↗