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Biomedical subjects

W Wagner

Publications and source records attributed to W Wagner.

At least 361 records · Page 20Linked to original sources
PubMed1967

Hydraulic compression of mice to 166 atmospheres.

Hydraulic uniform compression elicited tremors, uncoordinated limb movements, and tonic convulsions in liquid-breathing mice at pressures ranging from 50 to 100 atmospheres. Such abnormal muscular activity was observed neither in control animals nor in mice caudally to a spinal transection. Uniform compression of isolated preparations of mouse muscle in saline failed to contract at pressures up to 200 atmospheres.

Animals↗
PubMedDate not supplied

Acral lentiginous melanoma of the oral cavity.

Lentiginous melanomas may be classified clinicopathologically as either lentigo maligna melanomas or acral lentiginous melanomas. Lentigo maligna melanoma is generally characterized by its slow rate of growth, lateness of metastasis, and relatively good prognosis. Acral lentiginous melanoma, while demonstrating a radial growth phase which is histologically similar to that of lentigo maligna, appears biologically more similar to superficially spreading malignant melanoma once the vertical growth phase supervenes. Mucous membrane melanomas with lentiginous characteristics are likely to be aggressive lesions with a marked propensity for metastasis and a uniformly poor prognosis, much like the acral lentiginous type of melanoma. It would seem, therefore, that superficial melanomas of the oral mucous membranes with a lentiginous pattern should best be termed acral lentiginous melanomas instead of lentigo maligna melanomas so as to more accurately predict their true biologic potential. An amelanotic case is presented which we believe illustrates this point.

Aged↗
PubMedDate not supplied

Validation of three-dimensional surface characterising methods: scanning electron microscopy and confocal laser scanning microscopy.

Surface characteristics of enosseous titanium implants have been known to influence the quality of osseointegration. Parameters recommended for metrical analysis should be supplemented by a topographical description. In this study, Ra values obtained by established tactile and optical profilometric methods are correlated with those obtained by stereo scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). As test specimens, standardised CVD diamond-coated titanium alloys with different microwave coating power ranging from 2,000 to 3,000 W were used. A non-CVD-coated corund grit-blasted specimen (NC) was used as reference. After coating with a CVD, power of 2,000 W Ra ranges from 4.33 to 5.69 microm depending on the method used. With increasing power of the coating process, the amplitude of the surface roughness is significantly increased to 4.53 to 6.89 microm. Ra values of the same sample obtained by different methods are also significantly different (p = 0.001). Compared with the established methods of tactile and optical profilometry, SEM and CLSM offer valid data on the surface roughness accompanied by a topographical imaging. In future studies, the underlying method should be specified to interpret roughness values correctly, as not every method is suitable for each specimen and values obtained by different methods vary extremely.

Diamond↗
PubMedDate not supplied

[Antibacterial concentrations in serum and tooth-jawbone tissue following perioperative administration of propicillin].

Antibacterial Concentrations in Serum and Dental Tissues after Preoperative Application of Propicillin. After resecting radicular and follicular cysts in the jaws, the serum, bone, capsule and fluid of the cysts from 40 patients were studied for their propicillin concentration. The patients received 1 Mega unit (0.7 g) propicillin orally as oblong tablets one or two hours before surgery. One or two hours after the application of propicillin, the distribution coefficients between serum and the three tissues were 0.78 and 0.87 for the spongious bone, 0.07 and 0.06 for the cyst capsule and 0.14 and 0.08 for the cyst fluid. The mean concentrations in all three tissues were distinctly above the MICs of the bacteria most frequently isolated from the mouth for at least two hours.

Administration, Oral↗
PubMedDate not supplied

SEP testing in deeply comatose and brain dead patients: the role of nasopharyngeal, scalp and earlobe derivations in recording the P14 potential.

Median nerve somatosensory evoked potentials (SEPs) were tested in 50 patients (20 brain dead, 18 comatose and in 12 progressing from coma to brain death, i.e., 32 cases with brain death and 30 cases with coma were recorded). Derivations were taken from nasopharynx, earlobes, scalp, and neck using cephalic and non-cephalic references. Cortical and subcortical SEP components were evaluated, focussing on the P14 potential. There is evidence that rostral and caudal parts of the P14 generator (lemniscus medialis) are differently affected in brain death, resulting in an abolition of the rostral part, while occasionally leaving intact for some time the caudal part. Non-cephalic referenced scalp records pick up the whole P14 dipole, whereas nasopharyngeal and earlobe derivations pick up different parts of P14, depending on the reference used. Scalp-to-nasopharynx records derive the most rostral part of P14; this "rostral P14" was bilaterally lost in all brain dead patients, but preserved in all deeply comatose patients with diffuse brain-stem injuries. Scalp-to-earlobe records, in contrast, picked up a P14 dipole segment reaching more caudally, resulting in a P14 potential also in brain dead patients. It is concluded that midfrontal scalp-to-nasopharynx derivations give the most valuable contribution to the electrophysiological assessment of brain death versus deep coma.

Adolescent↗
PubMedDate not supplied

Neonatal rat cartilage has the capacity for tissue regeneration.

One of the most relevant issues in future medicine is tissue regeneration. Transplantation medicine alone cannot solve the problem of incurable conditions of vital organs. One approach to this might be the replication of the spontaneous regeneration that is found in embryonic/neonatal tissue. In this study, a tissue model for basic investigation of regeneration mechanisms in vivo was established. We demonstrated by histology and immunohistochemical staining for types I and II collagen that neonatal rat cartilage unlike adult cartilage has the capacity for rapid scarfree regeneration after full-thickness incision. The underlying mechanism was identified in the preserved proliferative capacity of neonatal chondrocytes. This in vivo model should prove useful in further studies of the role of cellular (e.g., GA cell cycle regulators) and extracellular (e.g., cytokines) factors in tissue regeneration and wound healing.

Animals↗
PubMedDate not supplied

[Cavernoma of the medulla oblongata mimicking "Anorexia nervosa" - a case report].

An 11-year-old girl presented with recurrent vomiting, reduced food and fluid intake, weight loss and dizziness. In an external hospital she was diagnosed as having habitual vomiting and a beginning eating disorder. The physical examination revealed a very thin, malnourished child with abdominal pain on palpation but without neurologic deficits. Laboratory findings, X-rays, endoscopy and ultrasound revealed no pathological results either. Since the EEG and the cranial computed tomography (CT) were normal, we also suspected the beginning of an eating disorder especially due to some psychical peculiarities. The MRI which was done for ultimate exclusion of an infratentorial tumor showed a well defined displacing structure in the dorsal medulla oblongata and in the upper cervical spinal cord. A corresponding prolongation of the central conduction time was found in the median nerve SSEP whereas the BAEPs were normal. The tumor was excised in toto and the histological examination confirmed the suspected diagnosis of cavernous hemangioma (cavernoma). The post operative phase was without any complications and the intiated nutrition was well tolerated. Neurological deficits were not observed.

Abdominal Pain↗