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Biomedical subjects

H Maier

Publications and source records attributed to H Maier.

At least 181 records · Page 10Linked to original sources
PubMed1994

[Surgical voice rehabilitation after laryngectomy by a modification of the Asai procedure].

A new technique of primary neoglottic reconstruction for surgical restoration of voice following total laryngectomy is described in detail. The procedure is based on the principle of Asai's technique, but can be performed as a one-step procedure. Within the last 2 years, the technique has been used in 20 patients with T2-T4 tumors without subglottic extensions and without extensive infiltration of the hypopharyngeal mucosa. The mean period of observation was 14.2 +/- 5.5 months. In two patients the speech fistula had to be removed because of aspiration problems, while six patients required dilatations of the fistula because of stenosis. As a long-term result a satisfactory voice was achieved without aspiration problems in 17 of 20 patients.

Follow-Up Studies↗
PubMed1993

Distribution of secretoneurin-like immunoreactivity in comparison with substance P- and enkephalin-like immunoreactivities in various human forebrain regions.

The distribution of secretoneurin-like immunoreactivity, a peptide derived from secretogranin II, was studied by means of immunocytochemistry and compared to the pattern of staining for substance P- and enkephalin-like immunoreactivities in the human basal forebrain, with special reference to the basal ganglia. Secretoneurin-like immunoreactivity was characterized by gel filtration and reversed-phase high pressure liquid chromatography analysis. Chromatographic analysis revealed a single peak for secretoneurin-like immunoreactivity. No secretoneurin-immunopositive forms of high molecular weight were found. Secretoneurin-like immunoreactivity appeared mainly in dot- and fibre-like structures. In addition, a band-like terminal staining (woolly fibres) that has been shown by others for substance P- and enkephalin-like immunoreactivities, was also observed for secretoneurin-like immunoreactivity. Medium-sized cells were found arranged in clusters or singly within the caudate and putamen. In the basal ganglia, a high density of secretoneurin-like immunoreactivity was found in the internal segment of the globus pallidus, the ventral pallidum and in the pars reticulata of the substantia nigra. In these areas the immunostaining appeared mainly as woolly fibres. The bed nucleus of the stria terminalis and medial amygdala displayed a high density of fine beaded secretoneurin-like immunoreactive fibres, sometimes forming pericellular contacts. The nucelus basalis of Meynert was highly innervated by secretoneurin-like immunoreactive fibres, mainly in the form of woolly fibres. In general, a large overlap was found between secretoneurin- and substance P-like immunoreactivity in all examined areas of the basal ganglia. In the bed nucelus of the stria terminalis and medial amygdala secretoneurin-like immunoreactivity was distributed very similarly to enkephalin-like immunoreactivity. These data provide evidence that in different subsets of neurons and neuronal pathways secretoneurin-like immunoreactivity coexists with substance P- and enkephalin-like immunoreactivity in several areas of the human brain.

Adult↗
PubMed1993

Immunostaining for proliferating cell nuclear antigen: its role in determination of proliferation in routinely processed human brain tumor specimens.

Alcohol- and formalin-fixed, paraffin-embedded samples of 71 brain tumors (35 gliomas, 22 metastatic carcinomas, 8 meningiomas and 6 other tumors) were investigated by immunocytochemistry with three different monoclonal antibodies against proliferating cell nuclear antigen (PCNA)/cyclin (19A2; 19F4; PC10). PC10 was found to work best; it is applicable to both alcohol- and formalin-fixed tumor samples. PCNA labeling indices (LIs) were compared in the same tumors with LIs obtained by Ki-67 immunostaining of frozen sections and by in vitro incubation with bromodeoxyuridine (BrdUrd); in the latter preparations, BrdUrd LIs could be compared with PCNA LIs in the very same areas of serial sections. In gliomas, PCNA LIs were 0.7-80.2% (mean 31.7%), in metastases 0-76.0% (mean 47.8%), and in meningiomas 0-53.0% (mean 19.3%). In general, PCNA LIs were highly significantly correlated with Ki-67 LIs (P = 0.0002) and BrdUrd LIs (P = 0.0001). However, when tumor subgroups are considered, only gliomas show a significant correlation with Ki-67 and BrdUrd LIs. Despite this statistical correlation, PCNA expression was out of proportion to proliferation indices as determined by both other methods in almost one third of all brain tumors. Immunocytochemistry for PCNA produces a broad spectrum of staining intensity of labeled nuclei, whose number is dependent upon the sensitivity of the immunocytochemical technique used. Thus, inter-observer and inter-laboratory variabilities in PCNA LI determination may occur. Overlapping of PCNA LIs between tumor subgroups of varying malignancy further limits the informational value for the individual case.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Expression of the histone H3 gene in benign, semi-malignant and malignant lesions of the head and neck: a reliable proliferation marker.

To search for a reliable proliferation marker in epithelial head and neck lesions, we have analysed the expression of the histone H3 gene by in situ hybridisation and compared this with the immunoreactivity of the widely used monoclonal antibody Ki-67. In many lesions, the Ki-67 staining failed to delineate proliferation. In contrast, the H3 hybridisation signals were in accordance with the histopathology of the biopsies: in hyperplastic epithelia, significant H3 mRNA levels were only seen in areas with inflammation. Dysplastic cells showed distinctly elevated H3 expression. Benign and semi-malignant tumours, i.e. basal cell carcinomas, showed moderate H3 signals at the periphery. In squamous cell carcinomas, H3 expression was always high at the expanding zone of the tumour and was most extensive in undifferentiated carcinomas. Thus, the expression of the histone H3 gene closely reflected the dynamics of neoplastic growth within and around head and neck tumours.

Biomarkers, Tumor↗
PubMed1993

[Balloon occlusion test of the internal carotid artery for evaluating resectability of blood vessel infiltrating cervical metastasis of advanced head and neck cancers--Heidelberg experience].

During the last two years 17 patients of the ENT-Department of the University of Heidelberg suffering from squamous-cell carcinomas of the head and neck underwent a balloon occlusion test of the internal carotid artery (ICA). The investigation was performed because of tumorous infiltration of the large cervical vessels. The balloon occlusion of the ICA was accomplished at the Department of Neuroradiology of the University of Heidelberg. While stopping bloodflow in the ICA of one side for 15-20 min, clinical, electrophysiological and Doppler sonographic monitoring was performed, to detect severe cerebral complications. The specific electrophysiological monitoring contained the detection of MSSEP's (median nerve stimulated somatosensorial evoked potentials) and TCMEP's (transcortical motor evoked potentials) during test occlusion. Balloon occlusion was not possible in three patients because of severe arteriosclerosis. Test occlusion had to be discontinued in three patients because of clinical complications (temporary amaurosis, orthostatic complications). Finally, seven patients showed contraindications during test occlusion for permanent occlusion of the ICA. Four patients had a permanent occlusion of the ICA after tumour resection. In two patients the ICA was removed without problems in test occlusion. The third patient underwent a permanent carotid occlusion because of bleeding complications (in spite of poor clinical tolerance of the test occlusion). In the fourth patient, only intraoperative neuromonitoring with MSSEP's was conducted before permanent carotid occlusion. All four patients did not show any neurological deficits after resection of the ICA. Neurophysiological monitoring played an important role in predicting cerebral complications after permanent occlusion of the ICA.

Adult↗
PubMed1993

Dental status and oral hygiene in patients with head and neck cancer.

Poor oral hygiene is believed to play a role as a risk factor for head and neck cancer, especially for oral cancer. Only few epidemiologic data exist about dental status and oral hygiene in these patients. We performed a case-control study involving 100 patients with squamous cell carcinoma of the upper aerodigestive tract and 214 age- and sex-matched control subjects with no known tumorous disease. In the tumor patients, oral hygiene and dental status proved to be significantly worse: the majority of the tumor patients seldom or never brushed their teeth and the frequency of dental visits was significantly lower. Tartar of 3 mm or more was found in 40.9% of the tumor patients and in 22% of the control subjects. In the tumor group, the incidence of decayed teeth was significantly higher compared with the control subjects. Chronic inflammation of the gingiva was observed in 28% of the tumor patients vs. 13.5% in the control group. Oral hygiene was negatively correlated with alcohol as well as with tobacco consumption. The social status of subjects also correlated with oral hygiene, which was found to be worst in subjects from the lower social strata. The present study revealed a poor dental status and oral hygiene in patients with head and neck cancer. The pathogenetic mechanism being associated with this suspected risk factor remains to be investigated.

Adult↗
PubMed1993

[Can muscle transposition of an antagonist modify regeneration of the peroneal nerve?].

The prognosis after injury and microsurgical repair of the peroneal nerve is poor. However, clinical experience seems to indicate better results if nerve repair or neurolysis is combined with transposition of the tibialis posterior muscle. This hypothesis was tested in 20 rabbits by severing the peroneal nerve of one lower extremity. Nerve repair with muscle transposition was performed in ten rabbits and nerve repair without muscle transposition in the remaining ten animals. Six to twelve months later, histological and histochemical studies of nerve and muscle tissue were performed. No significant differences between the two groups could be determined.

Animals↗
PubMed1993

[The epidemiology of parotid tumors. A case control study].

From 1989 to 1991 a case-control study was conducted at the ENT Department of the University of Heidelberg. One hundred and one patients with parotid tumors (84 benign and 17 malignant) were compared with 404 control patients in a matched-pair study design. Using a questionnaire containing 21 sides, all interviews were conducted by the same interviewer. The questionnaire contained such aspects as "professional surroundings and exposure to environmental dusts", "consumption of tobacco and alcohol", "living area", "nutrition", "hobbies" and "social life". Questions about personal and familial diseases, consumption of medicine and exposure to irradiation were also asked. Differences in exposure to occupational dusts were seen. The highest relative risk (RR) for developing a parotid tumor was seen with weekly exposure to nickel during a period of more than 10 years (RR = 6.0; confidence interval, 1.4-25.5). Similar risk was found with exposure to chromium, asbestos and cement dusts (RR chromium = 3.4; confidence interval, 0.9-14.5; RR asbestos + cement = cement 3.0, confidence interval 1.0-8.9). Higher relative risks were also detected in patients exposed to diagnostic dental x-rays.

Adult↗
PubMed1992

Intraoral cheek transposition flap for primary reconstruction of the soft palate.

A method for primary reconstruction of the soft palate following radical tumor resection is described. The resulting defects can be repaired with 2 layers of tissue by combination of a cranial pedicled pharyngeal flap and a cranial pedicled intraoral cheek transposition (IOCT-) flap. For additional resection of the lateral pharyngeal wall the technique can be combined with a masseter crossover flap. The method allows satisfying restoration of swallowing and speech with relatively small operative effort.

Deglutition Disorders↗
PubMed1992

The combined masseter muscle/intraoral cheek transposition (IOCT) flap for primary reconstruction of the dorsal oral cavity.

A method for primary reconstruction of the dorsal oral cavity after tumor resection of T2 or small T3 tumors is presented. By combination of the masseter muscle flap with a cranial pedicled intraoral cheek transposition (IOCT) flap, a reconstruction of the defects with two layers of tissue is possible. This easy and functional reconstruction method is especially useful for high-risk patients because of the markedly reduced operating time.

Aged↗
PubMed1992

Risk factors of cancer of the larynx: results of the Heidelberg case-control study.

Squamous cell carcinoma of the larynx is a multifactorial disease. It is firmly linked to several environmental risk factors. In the meanwhile, a considerable amount of epidemiologic evidence has been built up to implicate chronic consumption of alcohol and tobacco, occupation, diet, and social status in the etiology of the laryngeal cancer. Herein is a report from the first case-control study on the role of these risk factors conducted in a German population of patients with laryngeal cancer.

Adult↗
PubMed1992

Classic, atypical, and anaplastic meningioma: three histopathological subtypes of clinical relevance.

This study correlates the histopathological classification of meningiomas with clinicopathological features of biological activity. A retrospective evaluation of 1799 surgical specimens of meningiomas from 1582 patients was made. The classic histopathological type, atypical meningiomas defined by increased cellularity and at least five mitotic figures in 10 high-power fields, anaplastic (malignant) meningiomas, and hemangiopericytic or papillary meningiomas were seen in 87.6%, 7.2%, 2.4%, and 2.8% of operations, respectively. The rates of recurrence in surgically treated patients with classic, atypical, anaplastic, and hemangiopericytic or papillary meningiomas were 6.96%, 34.6%, 72.7%, and 68.2%, respectively. The extent of surgery and the tumor size and site were studied in detail in 252 tumors of all histopathological types. Recurrences were rare in classic meningiomas after complete resection, whereas atypical and anaplastic tumors recurred after complete resection much more frequently. Classic meningiomas, hemangiopericytomas, and papillary meningiomas were smaller at surgery than atypical and malignant meningiomas. Atypical and malignant tumors were operated on more often in falcine and lateral convexity regions than were classic meningiomas. To support the authors' subjective categorization by a quantitative parameter related to proliferation, 112 meningiomas comprising all histopathological subtypes were investigated for staining of argyrophilic nucleolar organizer region proteins (Ag-NOR's). The Ag-NOR counts showed significant differences between classic, atypical, and anaplastic tumors but no significant differences between primary and recurrent tumors. Hemangiopericytomas and papillary meningiomas had lower Ag-NOR values than anaplastic meningiomas. A correlation of Ag-NOR numbers with the authors' histopathological scale of malignancy supports the introduction of atypical meningiomas with intermediate biological behavior on the classification scale between classic and anaplastic meningiomas. Overlapping of Ag-NOR numbers among all groups of malignancy may restrict the prognostic value of Ag-NOR counting in the individual case.

Aged↗