Search PubMed⌕ Search

Biomedical subjects

A Lindner

Publications and source records attributed to A Lindner.

At least 109 records · Page 6Linked to original sources
PubMed1995

Preoperative and postoperative follow-up in high-grade gliomas: comparison of transcranial color-coded real-time sonography and computed tomography findings.

Twenty patients with high-grade gliomas were prospectively studied by pre- and postoperative transcranial color-coded real-time sonography (TCCS) and CT, to determine the sensitivity of TCCS in the identification of residual tumor and tumor regrowth. Each patient was subjected to preoperative and early postoperative CT (postoperative day 1) and TCCS examinations (postoperative days 6 to 8) and subsequent CT and TCCS follow-up examinations within a time interval of 6 weeks to 3 months. In eight patients, a total of 15 biopsy specimens were intraoperatively obtained from the wall of the resection cavity. Histological findings of intraoperative biopsy specimens showed that hyperechogenic areas adjacent to the resection cavity always contained residual tumor tissue. Early postoperative TCCS identified these hyperechogenic areas in 19 of 20 patients. In 12 patients, postoperative CT revealed contrast enhancement at the resection margin, indicating residual tumor. In these patients the extension of these hyperechogenic areas on TCCS exceeded the contrast-enhancing areas on CT by a mean of 58%. In eight patients, postoperative CT displayed no contrast enhancement along the border of resection. TCCS and histological findings indicated residual tumor in seven of these eight patients. The size of the hyperechogenic lesions identified by postoperative TCCS increased in time and follow-up examinations revealed that tumor regrowth arose from these hyperechogenic areas in all patients. In four patients, tumor regrowth was identified, on average 0.7 months earlier by TCCS than by CT. From these data we conclude that the sensitivity of TCCS in detection of residual tumor and tumor regrowth seems to be superior to CT. The value of TCCS requires further clarification by comparative studies including histology and MRI.

Biopsy↗
PubMed1995

Spontaneous ureteral stent fragmentation.

A series of spontaneous multiple fragmentations of 3 ureteral stents presenting with a variety of clinical features is reported. Physical analysis measuring the tensile mechanical properties was done of the retrieved fragments together with 2 new stents, as well as electron microscopy scanning of the retrieved fragments. This methodology in evaluating fractured stents is unique in its capability to determine the accelerated aging process of stent material and to our knowledge has not been reported previously in this context. The retrieved catheters were moderately incrusted. The tensile elongation (maximal elongation at break point), known to be a sensitive indicator of the aging process of plastic materials, was dramatically decreased in the retrieved stents. The fractures in all catheters retrieved as well as in the new stents were found to pass exclusively through the side holes. Fragmented catheters had a distinctive electron microscopic appearance and physical properties, which may be defined in a systematic manner and may contribute to further refinement of stent quality.

Adult↗
PubMed1995

Ureteroscopy for ureterolithiasis with sedation only.

We examined the feasibility of performing ureteroscopy under sedation only. Twenty-eight ureteroscopies performed with sedation only were compared to 18 performed in an operating room setting. Durability towards the procedure was good in 86% of the cases. Stone-free rates were 42 and 72%, respectively. Fifty-seven percent of the patients required hospitalization with the most common complication being low-grade fever. Although our success rate is less favorable for sedation only, this setting is feasible, and in nearly half of the patients hospitalization was avoided with no need for an expensive operating room facility. Careful patient selection, a sharp learning curve and small-french instruments combined with pneumatic lithotriptors may also improve the results.

Adult↗
PubMed1995

Autoantibodies to prostate specific antigen in patients with benign prostatic hyperplasia.

PURPOSE: We tested for a possible autoimmune process in benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: Titers of IgG antibodies to prostate specific antigen (PSA) were measured in the sera of 85 BPH patients, 20 controls and 17 chronic prostatitis patients by enzyme-linked immunosorbent assay. RESULTS: The mean anti-PSA titers in the BPH group were significantly higher than in the controls and prostatitis group (p < 0.0005). Accordingly, 59% of BPH patients could be defined as responders to PSA compared to none among the controls (p < 0.0005). CONCLUSIONS: Circulating autoantibodies to PSA were shown to exist in the sera of BPH patients. This observation suggests that autoimmune processes may have a role in BPH.

Adult↗
PubMed1995

[C-reactive protein (CRP)--an acute-phase protein with importance in laboratory medicine in veterinary medicine].

CRP is an acute phase protein (APP) formed by hepatic cells in acute phase reaction (APR). APR is initiated by a broad spectrum of cytokines of activated macrophages of blood and tissues. During the APR, plasma concentrations of APP are changed. Cytokines regulate APPs. CRP is a phylogenetically very old molecule. The degree of homology of amino acids in CRP is very high in a lot of species. CRP binding specificities depend on Ca++. The diagnostic importance of CRP in veterinary medicine is discussed.

Animals↗
PubMed1995

[The status of transcranial color-coded real time ultrasound in diagnosis of cerebral lesions].

Transcranial color-coded real-time sonography (TCCS) combines transcranial Doppler sonography and color-coded B-mode scanning of the brain parenchyma and cerebral vessels. This technique is not invasive and a broad spectrum of intracerebral lesions such as vascular lesions (ischemic stroke and intracerebral hemorrhage, aneurysms, arteriovenous malformations, arteriosclerotic vascular degeneration) and parenchymal lesions (brain tumors, degenerative and neuropsychiatric disorders) can be disclosed. Compared with MRI and CT, the ultrasound system is movable. Thus, it can be used easily in emergency rooms and intensive care units. In addition, TCCS can disclose new insights into the pathophysiology of disorders of the CNS, as in neuropsychiatric diseases. Ultrasound contrast agents improve the depiction of intracranial vessels. The pathology of the venous system can be identified.

Adult↗
PubMed1995

[Indications and use of stereolithographic skull reconstructions in oromaxillofacial surgery].

Stereolithography (SLA), a rapid prototyping technique, was introduced in 1991 at the Clinic for Maxillofacial Surgery in Vienna and was adapted, in cooperation with the company Laserform, for our clinical requirements. As a refinement to physical models milled out of polyurethane, which had been used since 1989, this technique offered new applications for preoperative planning in craniomaxillofacial surgery. The proportions of these 3D models correspond 1:1 to the patients dimensions, with a possible accuracy of 0.25 mm. Since 1992 stereolithography has been used in 124 cases, primarily in traumatology, tumor surgery and in craniofacial surgery.

Adult↗
PubMed1995

Presence of human papilloma virus in transitional cell carcinoma in Jewish population in Israel.

The possible causal association of human papilloma virus (HPV) with transitional cell carcinoma (TCC) of the urinary bladder in Israeli Jewish patients was assessed. One hundred and ten histopathological TCC sections were examined by peroxidase anti-peroxidase (PAP) method. HPV capsid antigen was demonstrated in 19 out of 110 cases (17.3%). HPV-DNA sequences, determined by in situ DNA-DNA hybridization at high stringency wash were present in 24 cases (21.8%): 16(14.5%) cases proved to be HPV6/11 and 8 (7.3%) were HPV 16/18 positive. Four (3.6%) of the HPV 6/11 positive specimens cross hybridized with HPV 31/33/35 at low stringency conditions. Sixteen samples known to be positive by in situ hybridization were reconfirmed by polymerase chain reaction (PCR). When the PCR was performed on the 43 negative cases, an additional 4(9.3%) HPV positive cases were revealed: two proved to be HPV 6/11 and two HPV 16/18. Comparison of the different methods for HPV detection in 59 TCC histopathological samples, showed good correlation; an overall positivity of 33.9% by PCR, 27.1% by in situ hybridization and 25.4% by PAP was observed. Forty one samples from nontumoral material of the bladder or post mortem specimens served as controls and 4.8% HPV DNA was present in only two cases: one HPV 6/11 and one 16/18. Hence, HPV in TCC of the bladder is detected at a relatively high frequency and might be involved in the pathogenesis of this tumor among Jewish population in Israel.

Antigens, Viral↗
PubMed1994

[Early spontaneous fragmentation of a ureteral stent].

The use of ureteral stents to assure continuity and patency of the upper urinary tract has become common in endo-urology. We present an 82-year-old bedridden woman with hydronephrosis and pseudomonas sepsis. Because of ureteropelvic junction stenosis a stent was inserted. Shortly thereafter the stent fragmented spontaneously into 5 pieces. The importance of being familiar with endo-urological manipulations and their complications is emphasized.

Aged↗
PubMed1994

Contribution of transcranial color-coded real-time sonography to the etiopathogenetic classification of middle cerebral artery stenosis.

Transcranial color-coded real-time sonography (TCCS) and cranial computed tomography were applied to patients with middle cerebral artery (MCA) stenosis to evaluate whether these techniques may disclose additional aspects of the pathophysiology of the stenotic lesion. In 15 patients with MCA stenosis identified by transcranial Doppler sonography, the echogenicity of the stenotic segment was estimated subjectively by TCCS. The density of the stenotic segment, prior to being detected by TCCS, was quantified by computed tomography. In 5 of the 15 patients, transcranial image-directed Doppler sonography identified a hyperechogenic lesion in association with the stenotic vascular segment; computed tomography demonstrated a "dense" artery (Hounsfield units [HU] > 120) in the corresponding vascular segment. In 10 patients the echogenicity of the stenotic segment was found to be normal, with a computed tomography density of < 100 HU in the corresponding segment. Hyperechogenic and hyperdense stenotic vascular segments in TCCS and computed tomography, respectively, may indicate an arteriosclerotic vascular lesion with calcium deposits. Normal echogenicity and normal to slightly elevated computed tomography-density of a stenotic vascular segment may suggest the presence of a thrombotic/embolic lesion.

Adolescent↗
PubMed1994

Reliability of transcranial colour-coded real-time sonography in assessment of brain tumours: correlation of ultrasound, computed tomography and biopsy findings.

Transcranial colour-coded real-time sonography (TCCS) was carried out in 25 patients with brain tumours to determine whether this noninvasive method provides additional information about the extent of solid tumour, its differentiation from oedema, and its tissue components. All 25 patients had serial computed tomography (CT)-guided stereotactic biopsies. Comparison of ultrasound, CT and histological findings revealed that the vast majority of contrast enhancing areas on CT were hyperechogenic (32/33; 97%) and contained tumour tissue (29/32; 91%). Hyperechogenic areas always represented solid tumour (23/23 patients), even when CT showed low density non-enhancing lesions. In lesions hypoechogenic on TCCS and low density on CT, histology consistently revealed necrotic tumour (7/7). Biopsies obtained from parenchyma with normal echogenicity revealed tumour in only 3 of 16 specimens. Despite the high specificity of TCCS in the differentiation of tumour components, its sensitivity to tumour was inferior to that of CT (24/25; 96%). TCCS thus allows noninvasive preoperative identification of tumour tissue and its extent setting.

Biopsy↗
PubMed1994

Identification of ventricular enlargement and estimation of intracranial pressure by transcranial color-coded real-time sonography.

Transcranial color-coded real-time sonography (TCCS) was applied to 26 patients with ventricular enlargement to quantify the ventricular size and to estimate intracranial pressure. Intracranial pressures, as determined by lumbar, epidural, or ventricular tonometry, ranged from 6.5 to 55 cm H2O (8 patients had pressures > 18 cm H2O). The widths of the third ventricle and the frontal horns of both lateral ventricles depicted by TCCS were compared to corresponding computed tomography data: TCCS and computed tomography findings correlated well for the third ventricle (r = 0.96) and for the right (r = 0.86) and left (r = 0.92) frontal horns. The capability of the septum pellucidum to undulate relative to the ventricular wall during short (20-degree) rotatory movements of the head was related to intracranial pressure. In all patients with intracranial pressure below 17 cm H2O, rotatory head movements induced septum pellucidum undulation; no lateral deflection of the septum pellucidum was found in patients with an intracranial pressure above 21 cm H2O. Therefore, TCCS may be employed to quantify and follow-up ventricular enlargement. Dynamic neurosonographic tests may allow a gross estimation of intracranial pressure.

Adult↗
PubMed1994

Effects of training on blood lactate-running speed relationship in thoroughbred racehorses.

In this study the effects of training history on the results of a standardized two-speed test in competing Thoroughbreds were investigated during a racing season. For nine Thoroughbreds, 1,755 training days were recorded. Within the observation period each horse completed a two-speed field test at intervals of 6-8 wk to determine its running velocity (v) eliciting blood lactate concentrations of 4 (v4) and 12 mmol/l (v12). Horses performed 29 two-speed tests. Changes of v4 and v12 in a horse between two consecutive tests were used to assess effects of training history variables calculated for the period between two consecutive tests. The percentage of days with gallop workouts between two consecutive tests showed a significant correlation with changes in v4 (r = 0.71, P < 0.01) and v12 (r = 0.56, P < 0.05). The number of gallop workouts (r = 0.60, P < 0.05) and the total time of training (r = 0.58, P < 0.05) correlated with the change of v4. Furthermore the percentage of days without training was negatively correlated to changes of v4 (r = -0.75, P < 0.01) and v12 (r = -0.56, P < 0.05). Therefore the actual training caused changes in the blood lactate-running speed relationship despite its relatively low volume, intensity, and frequency. Future studies have to evaluate how the training variables can be changed to improve the training effects on the blood lactate-running speed relationship of competing Thoroughbreds.

Animals↗
PubMed1994

[Technique and applications of stereolithographic cranial models].

3-D-modelling of the skull is useful referring to improve diagnostics, for surgical planning and simulation of surgical procedure. Stereolithography is a constructive process producing a model by building it up layer by layer with plastic using an "ultraviolet" laser to catalyse the polymerization of a liquid plastic solution. This fast prototyping derives from using a new interface between a CT-Scanner and a SLA. By avoiding the tool path problems inherent in conventional computerdriven CNC milling machines we succeeded in producing closed cavities and even intraosseous course of vessels and nerves. The compact and smooth surface makes manual postprocessing unnecessary. By using a new software (interpolation +/- 0.25 mm) we could improve the accuracy. At our studies we found a maximum aberration of at least 0.25 mm.

Adolescent↗
PubMed1994

[Effect of the time of sample collection after exertion and the specimen handling on the lactate content in the blood of horses].

The mean maximal lactate concentration of horses after exercise (Lamax) amounted to 4.5 +/- 2.2 mmol/l for gallop workouts of less than 11 m/s and more than 180 s (n = 35; category A), at more than 11 m/s and less than 180 s duration (n = 17; category B) to 16.3 +/- 4.8 mmol/l and at less than 11 m/s and less than 180 s duration (n = 10; category C) to 4.6 +/- 1.6 mmol/l. Lamax was always measured immediately after exercise following exercise of categories A and C. But for exercise bouts of category B Lamax was measured between the first and the tenth minute after exercise. Following exercise bouts in this category, mean lactate concentrations measured in two-minute intervals before and after Lamax always differed significantly (p < 0.01 to p < 0.001). The lactate concentration did not vary within seven days in whole blood samples deproteinized immediately after collection and in plasma samples. In the same sample material, when kept frozen, lactate contents remained stable for 60 days. In whole blood samples treated with Na-heparin or Na-heparin/Na-fluoride stored at 20-22 degrees C and 4 degrees C, the lactate concentration had already increased significantly within the first 24 hours.

Animals↗