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Biomedical subjects

W Wagner

Publications and source records attributed to W Wagner.

At least 217 records · Page 12Linked to original sources
PubMed1988

Sonography of the distal male urethra--a new diagnostic procedure for urethral strictures: results of a retrospective study.

We describe a new method of ultrasound investigation of the distal male urethra. With this procedure the periurethral structures are outlined, and the extent of periurethral scarring can be shown. In a retrospective study only strictures with significant periurethral scars recurred after internal urethrotomy. Patients without prominent scars had no stricture recurrence at the previous location. This new method allows for the appropriate decision to be made easier for optimal treatment of urethral strictures.

Humans↗
PubMed1988

Active and inactive forms of hemolysin (HlyA) from Escherichia coli.

The HlyA protein (Mr 110 kDa) which is the gene product of the hlyA gene encoded by the hemolysin determinant of Escherichia coli (Goebel, W. & Hedgpeth, J. (1982) J. Bacteriol. 151, 1290-1298) was observed to accumulate in the culture supernatant (in the presence of the three other Hly proteins HlyC, B and D) throughout the active growth cycle. However, the amount of extracellular HlyA protein did not correlate with the external hemolytic activity, which declined when the cells entered the stationary phase. External hemolytic activity was highly sensitive to phospholipase C and to ultrasonication. The size of the HlyA protein on SDS-PAGE was not changed by these treatments although the hemolytic activity was entirely abolished. On a polyacrylamide gel containing 2M urea but only 0.1% SDS hemolytically active HlyA migrated slightly ahead of the inactive HlyA suggesting that HlyA is more negatively charged than HlyA. Active hemolysin from unconcentrated hemolytic supernatants migrated on Sephacryl S-400 and on glycerol gradients as large complexes. Analysis of the hemolytically active fractions on SDS-PAGE yielded in both cases only HlyA (110 kDA) as major protein. An internal hemolytic activity appeared in most Escherichia coli K-12 strains in the stationary phase which was independent of the presence of HlyA or any other Hly gene product. This hemolytic activity which reached in some strains about 10% of the level determined by the hly genes was sensitive to proteinase K and disappeared upon shift of the cells to the logarithmic phase.

Chromatography↗
PubMed1988

[Recording of subcortical somatosensory evoked potentials using nasopharyngeal electrodes--a study in sedated patients].

Nasopharyngeal recording of evoked potentials is only seldom used, and a systematic description of subcortical SEP derivations using this method is essentially lacking. In twelve patients, sedated after neurosurgical operations and without signs of brainstem or cervical spinal cord dysfunction, subcortical SEP were recorded from nasopharynx (Pgz) and neck after stimulation of median and tibial nerves. Generally, a midfrontal reference (Fz) was used; in four cases, evoked potentials were additionally recorded against a non-cephalic reference. The main feature in Pgz-Fz recordings was a negative wave corresponding to the N13 (N30) component in neck derivations after stimulation of median (tibial) nerve. This wave is interpreted as reflection of medial lemniscal activity; so Pgz-Fz derivations make possible the isolated recording of the subcomponent N13b (medial lemniscus, or cuneate nucleus), without overlap with N13a (dorsal horn) - as do neck-to-scalp recordings-; and without the considerable artifacts known from farfield recordings. This interpretation is confirmed by SEP recordings in a brain death patient, showing a clear N13 component in neck-to-scalp derivations while lacking any negative wave at Pgz-Fz. In Pgz recordings against a non-cephalic reference, the P9 and P11 components (corresponding to the well known scalp farfield potentials) were clearly seen, whereas the P14 component was of low amplitude in three cases and lacking at all in one case. In conclusion, nasopharyngeal electrodes provide a useful tool in subcortical SEP recording; due to their position medio-ventrally to the lower brainstem, they complete standard electrode montages giving further informations about generator dipole location.

Adult↗
PubMed1988

[The effect of subcutaneous nitrosamine injections on the origin of tumors of the liver and their inhibition by vitamin C].

Experiments were conducted on Wistar rats for the purpose of finding out, whether peroral vitamin C application is capable of inhibiting carcinogenesis through subcutaneous injection of nitrosamine. One group of animals received injections of N-nitrosodiethylamine, while high doses of vitamin C were additionally administered to a second group in drinking water. Vitamin C only was given to a third group (control). Numerous liver carcinomas developed in response to nitrosamine application. No numerical difference was found to exist between the groups with and without vitamin C.

Animals↗
PubMed1988

[Is cerebral panangiography unnecessary in determining brain death?].

UNLABELLED: The diagnosis of brain death, i.e. death of cortex and brainstem, can be established by neurologic examination only if there is no intoxication, sedative therapy, or hypothermia. In the latter cases, until now only cerebral panangiography can establish the diagnosis. We investigated, whether in these cases cerebral perfusion scintigraphy (CPS) in combination with brainstem auditory evoked potential (BAEP) can replace CPA for establishing the diagnosis. METHODS: 40 patients, treated in our interdisciplinary ICU because of primary or secondary brain lesions and in whom determination of brain death by neurological examination was contraindicated, were subjected to the following procedure: When coma was diagnosed, brainstem reflexes were examined. If negative, an atropine-test was done and this being negative, apnea-testing was performed. If apnea was positive, BAEP, CPS and CPA were performed. The results of BAEP and CPS were compared with the results of CPA. RESULTS: In 38 patients with suspected brain death the first examination showed complete correspondence between BAEP and CPS on one hand and CPA on the other hand (Table 3). In patient No. 39, CPS as well as CPA showed minimal supratentorial circulation, whereas BAEP were negative as was circulation in the fossa posterior. In patient No. 40 as well CPS and CPA showed minimal supratentorial circulation. Brainstem testing with BAEP was negative although CPA showed minimal brainstem perfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain↗
PubMed1988

[Auditory evoked potentials in determining brain death].

Until now, in hypothermic patients, patients under barbiturate therapy etc. brain death can only unequivocally be determined by cerebral panangiography. We evaluated in 41 patients, whether panangiography can be substituted by recording of brain stem auditory evoked potentials in combination with cerebral perfusion scintigraphy. Our results demonstrate, that even if no potential except wave I can be recorded, a minimal intracranial perfusion may exist, so that by definition the patient is not dead. During the course of our investigations we found one patient, in whom disappeared auditory evoked potentials recovered. So we conclude, that the recording of auditory evoked potentials is only an adjunct in determination of brain death, not an objective method as is cerebral panangiography. But recording of auditory evoked potentials is helpful in excluding brain death in certain patients.

Brain Death↗
PubMed1987

Alkaline phosphatase which lacks its own signal sequence becomes enzymatically active when fused to N-terminal sequences of Escherichia coli haemolysin (HlyA).

Fusion of the alkaline phosphatase gene (phoA) which lacks its own signal peptide sequence to the N-terminal region of hlyA, the structural gene for Escherichia coli haemolysin, leads to active alkaline phosphatase (AP). AP activity depends on the length of the N-terminal region of hlyA. An optimum is reached when 100-200 amino acids of HlyA are fused to PhoA but fusion of as little as 13 amino acids of HlyA to PhoA is sufficient to yield appreciable AP activity. When cells are treated with lysozyme most of the AP activity is found associated with the membrane fraction but a substantial amount is also found in the soluble fraction, most of which may represent a periplasmic pool of AP. The soluble portion of AP activity is significantly increased when the cells are disrupted by ultrasonication, which indicates that the fusion proteins are only loosely associated with the membrane and that large parts are already located on the outside of the cytoplasmic membrane. The expected fusion proteins were identified in the soluble and the membrane fractions and their amounts in these fractions correlated well with AP activity.

Alkaline Phosphatase↗
PubMed1987

Psammous desmo-osteoblastoma. Ultrastructural and immunohistochemical evidence for an osteogenic histogenesis.

Fibro-osteo-cemental lesions of the jaw bones are a heterogeneous group of diseases which present problems in classification. Psammous desmo-osteoblastoma is one of four newly proposed entities (Makek 1983) and has until now been characterized by its light microscopic, clinical and radiological features. On electron microscopy this tumour exhibits fibroblastic (preosteoblastic), osteoblastic and osteocytic cells and a globular mineralization unlike the mineralization of the psammoma bodies. Immunohistological investigations with anti-osteonectin, a bone specific protein linking mineral to collagen, showed positive intracellular staining in all tumour cells and extracellular staining in the osteoid. The psammoma bodies were, however, not stained. These results confirm the view of the osteogenic histogenesis of psammous desmo-osteoblastoma, with an osteogenic differentiation of the tumour cells, bone formation and association of psammoma bodies which are not of bone origin. This combination of findings supports the view that psammous desmo-osteoblastoma represents a new and distinct entity occurring in desmal preformed cranio-facial bones which should be incorporated in a revised WHO-classification.

Adolescent↗
PubMed1987

Experimental studies on the disappearance of subretinal fluid after episcleral buckling procedures without drainage.

We have developed an experimental model to show that an additional mechanism apart from absorption by pigment epithelium is responsible for the absorption of subretinal fluid. The cause of a fast diminution of subretinal fluid after a buckling procedure is the prominence of the buckle as an obstacle to fluid movements in the eye. This results in any fluid being pushed through the retinal hole into the vitreous. When the retinal hole is closed by the buckle, the remaining part of the subretinal fluid is slowly absorbed by the pigment epithelium present. We performed a preliminary qualitative and quantitative analysis of the phenomena occurring using the finite element method of Zienkiewicz.

Absorption↗
PubMed1987

[Atypical ultrasound picture of pleomorphic adenoma].

Presentation of an atypical sonomorphology in a case of pleomorphic adenoma of the parotid gland. The tumour was resected and worked up for histological examination. The results emphasise the difficulty of differentiating the subtypes of parotid neoplasms by ultrasonography alone.

Adenoma, Pleomorphic↗
PubMed1987

[Sonographic diagnosis of mesothelial cyst of the diaphragm].

We present a case of a female patient of 65 years of age, who was referred to our clinic for surgery because of a suspected intrahepatic cyst, and who was suffering from upper abdominal complaints. Detailed sonographic examination revealed a cystic process outside the liver, the respiratory shift of structures during the sonographical examination being the criterion. However the final diagnosis of a mesothelial cyst of the diaphragm was possible only after laparotomy and histological examination.

Aged↗
PubMed1987

[Sensitivity and specificity of sonography and sialography in relation to the diagnosis of parotid tumors].

The results of parotid sialography from a group of patients between 1980 and 1982, were subjected to retrospective evaluation, and compared with sonographic results from another group between 1983 and 1985. In the first period studied sialography showed 75% sensitivity and 100% specificity. Both sensitivity and specificity of sonography were 100% in the second group. Thus, sonography appears superior with regard to diagnosis of intraglandular tumours of the parotid.

Humans↗
PubMed1987

Differential effects of a new dibenzo-epine neuroleptic compared with haloperidol. Results of an open and crossover study.

Fluperlapine (NB-106-689) was tested on 26 schizophrenic patients in an open and crossover study. In addition to its good antipsychotic effect, it also alleviated the apathic and depressive syndromes. Six patients who had shown only slight or no improvement after 4 weeks of haloperidol therapy responded positively to fluperlapine. The alleviation of the anergic syndrome was especially impressive. The therapeutic response of the depressive-apathic syndromes could represent an important extension of pharmacotherapy for schizophrenia. The virtual lack of extrapyramidal motor side effects with fluperlapine supports an intensification of the search for other nonclassic dibenzo-epine neuroleptics.

Adolescent↗