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Biomedical subjects

W Maier

Publications and source records attributed to W Maier.

At least 271 records · Page 15Linked to original sources
PubMed1996

[Lermoyez syndrome--electrocochleographic studies].

BACKGROUND: Lermoyez's syndrome is usually regarded as a rare variant of Menière's disease with hearing improvement and reduction of tinnitus during vertiginous attacks. Electrocochleographic studies of this syndrome are restricted to one published case up to now. METHODS: In our ENT department we clinically and electrocochleographically examined three patients suffering from Lermoyez's syndrome. These results were compared to those typically found in Menière patients. RESULTS: Two of the three patients did not show an elevated summating potential or increased ratio of summating potential and compound action potential (SP/CAP ratio). There was no hearing improvement following oral glycerol administration, and the SP/CAP ratio did not change during a Lermoyez attack. On the other hand, we observed normal cochlear microphonics in ears affected by Lermoyez's syndrome, indicating good hair cell function. In one ear, the threshold of cochlear microphonics was even better than the pure tone threshold. CONCLUSIONS: Our observations suggest that endolymphatic hydrops may not be always the underlying pathologic correlate of Lermoyez's syndrome. Thus Lermoyez's syndrome should not be simply regarded as a variant of Menière's disease.

Action Potentials↗
PubMed1996

[Malignant head-neck tumors in childhood--an interdisciplinary challenge from the viewpoint of the ENT physician].

BACKGROUND: Malignant tumors of the head and neck are very rare in children, and their symptoms are usually uncharacteristic. In most cases these tumors are of mesenchymal origin: sarcoma or lymphoma. As their growth is quick and destructive, irreversible damage of adjacent structures or even infiltration of the endocranium occurs early and rapidly, resulting in a dramatic deterioration of survival rate and life quality in advanced stages. PATIENTS: Three cases of a malignant head-and-neck tumor in children are described, stressing typical key symptoms which might often be neglected or misinterpreted as aggravation or psychogenic if the physician is not aware of the possibility of a malignant tumor. The diagnostic and therapeutic approach is illustrated according to the tentative diagnosis and the underlying histologic results. RESULTS: In any suspicious case, diagnostics must start immediately and often under emergency conditions. Interdisciplinary communication is mandatory from the beginning and should be directed by oncopediatricians. Since there are often fundamental differences in diagnostic procedures and therapeutic regimen compared with malignant tumors in adults, unnecessary repetitive examinations and consecutive delay in the onset of therapy can be avoided by early planning of a diagnostic strategy. Therapeutic principles differ widely from those in malignancies of adults. Following biopsy, histological examination, and staging, cytostatic chemotherapy and/or radiation is usually performed, but surgical procedures are indicated only in rare cases in the presence of a very small tumor. Mutilating surgery is always contraindicated in children. Restaging should follow conservative therapy, after which surgical removal of necrotic masses or residual tumor may be indicated. CONCLUSIONS: An immediate onset of diagnostics and therapy is crucial for children's prognosis concerning survival and function of affected organs. An interdisciplinary approach is mandatory from the beginning. In early cases, this strategy gives a chance to restore organ function and life quality. In advanced cases, life and a residual organ function may be preserved but complete restoration is rare, especially if a rhabdomyosarcoma is the underlying histologic diagnosis.

Adult↗
PubMed1996

Spontaneous otogenic pneumocephalus.

A very rare case of otogenic pneumocephalus in a healthy 24-year-old man with a widely pneumatized right mastoid, precipitated by forceful Valsalva's maneuver, is reported. When a pneumocephalus is suspected, computed tomography scans are mandatory. The pertinent literature is discussed and the potential mechanisms causing spontaneous pneumocephalus are described. To the best of our knowledge, only two other similar cases have been reported up to now.

Adult↗
PubMed1996

Gender and AD.

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Aged↗
PubMed1996

Co-occurrence and contransmission of affective disorders and alcoholism in families.

The analysis of patterns of co-occurrence and cotransmission of affective disorders and alcoholism in families may provide clues for understanding the excess comorbidity between these conditions in clinical settings and in the general population. This paper reports the results of a family study of the relatives of patients with bipolar disorder, unipolar depression and alcoholism, and combinations thereof. Excess comorbidity between affective disorders and alcoholism was observed in all groups of relatives. However, the sharing of familial aetiological components was not a major contributor to the excess comorbidity between affective disorders and alcoholism. Unipolar depression and alcoholism segregated independently in families, whereas a modest correlation between familial components of alcoholism and bipolar disorder was observed.

Adolescent↗
PubMed1996

[Psychiatric diseases and their treatment in general practice in Germany. Results of a World Health Organization (WHO) study].

As part of an international study initiated by the World Health Organization (WHO) about psychological disorders in primary health care, patients in the Federal Republic of Germany were compared with patients in other European centres. Patients from Germany do not differ from other European patients in respect to sociodemographic variables or psychiatric disorders. The most frequent CIDI-based diagnoses recorded in patients attending general practices are current depressive episodes (8.6%), generalized anxiety disorders (8.5%), neurasthenia (7.5%), and alcohol dependence (6.3%). In 20.9% of the patients at least one psychiatric diagnosis based on ICD-10 was recorded. In Germany significantly lower global ratings of health status are given than in other European centres although there is no difference in diagnostic prevalence rates. The recognition rate, i.e. the agreement between the CIDI-based ICD-10 diagnoses and the recognition as a case by the physician, is 56.2%-60.2%. On the other hand, the CIDI detects 90% of the patients described as psychologically ill by the physicians if subthreshold cases are also counted, or 46.4% if only defined diagnoses are taken into account. There is a significant correlation between severity of the psychiatric disorder and disability in social functioning. In Mainz and in the other European countries the disability rate of patients with a well-defined disorder is between 67.0% and 72.7%, whereas in Berlin this relation is not as clear, because especially in East Berlin there is a higher rate of unemployment in view of the political situation. Drug treatment is prescribed for 16.1% of the patients in primary care for psychiatric disorders. Half the patients recognized by physicians as cases receive medication. In the rest of Europe patients receive significantly more tranquillizers than in Germany, where the use of herbal drugs is more wide spread.

Adult↗
PubMed1996

The human serotonin 7 (5-HT7) receptor gene: genomic organization and systematic mutation screening in schizophrenia and bipolar affective disorder.

In the present study, we evaluated the possible contribution of genetic variation of the serotonin 5-HT7 receptor to the development of schizophrenia and bipolar affective disorder. Cloning and characterization of exon-flanking intronic sequences enabled us to investigate the whole coding region and the exon-intron boundaries of the human 5-HT7 receptor gene. Using single-strand conformational analysis, we screened for presence of DNA sequence variation in a sample of 137 unrelated individuals including 45 schizophrenic and 46 bipolar affective patients, as well as 46 healthy controls. We detected two rare naturally occurring receptor variants (Pro-279-Leu, Thr-92-Lys) and a silent nucleotide substitution (A-->G) at position +1233. The occurrence of the Pro-279-Leu and Thr-92-Lys substitutions was studied in an extended sample of patients (n = 462) and controls (n = 335). The Leu-279 variant was found in similar frequency in all groups, indicating that presence of this variant is not causally related to the development of schizophrenia or bipolar affective disorder. The Lys-92 variant was found in a single individual who suffered from bipolar affective disorder. Investigation of the patient's family revealed independent segregation between the Lys-92 variant and psychiatric illness. Our data suggests that genetic variation of the 5-HT7 receptor does not play a major role in the development of bipolar affective disorder and schizophrenia.

Bipolar Disorder↗
PubMed1995

Personality disorders and personality variations in relatives of patients with bipolar affective disorders.

Family studies may elucidate etiological relationships between two psychopathological conditions. This study explored the prevalences of personality disorders (DSM-III-R) and the variation of personality traits measured by the Munich Personality Test (MPT) in first-degree relatives of patients with bipolar disorder in comparison to control families recruited in the general population. Although the overall prevalence of having any personality disorder did not distinguish both groups of relatives we found significantly more compulsive personality disorders among relatives of probands with bipolar disorder. Relatives of patients with bipolar disorder also revealed significantly higher mean scores of "rigidity' (MPT); other personality traits, including neuroticism and extraversion, did not distinguish both groups. The observed differences in personality features between both groups of relatives are not mediated by current or previous axis I disorders. Therefore, they may reflect overlap of etiological factors of familial origin.

Adult↗
PubMed1995

Linkage analysis between pericentrometric markers on chromosome 18 and bipolar disorder: a replication test.

Replication was attempted of a recent report on linkage between bipolar affective disorder and pericentrometric loci on chromosome 18. Linkage to these markers was excluded in a sample of five extended multiplex families using lod-score and affected-pedigree-member methods. In one family, however, the lod score exceeded 1.0. Although the proposed susceptibility genes are unlikely to have a major impact on the occurrence of bipolar disorder, they might modify the genetic risk in a minority of familial cases.

Adult↗
PubMed1995

Systematic screening for mutations in the promoter and the coding region of the 5-HT1A gene.

In the present study we sought to identify genetic variation in the 5-HT1A receptor gene which through alteration of protein function or level of expression might contribute to the genetic predisposition to neuropsychiatric diseases. Genomic DNA samples from 159 unrelated subjects (including 45 schizophrenic, 46 bipolar affective, and 43 patients with Tourette's syndrome, as well as 25 healthy controls) were investigated by single-strand conformation analysis. Overlapping PCR (polymerase chain reaction) fragments covered the whole coding sequence as well as the 5' untranslated region of the 5-HT1A gene. The region upstream to the coding sequence we investigated contains a functional promoter. We found two rare nucleotide sequence variants. Both mutations are located in the coding region of the gene: a coding mutation (A-->G) in nucleotide position 82 which leads to an amino acid exchange (Ile-->Val) in position 28 of the receptor protein and a silent mutation (C-->T) in nucleotide position 549. The occurrence of the Ile-28-Val substitution was studied in an extended sample of patients (n = 352) and controls (n = 210) but was found in similar frequencies in all groups. Thus, this mutation is unlikely to play a significant role in the genetic predisposition to the diseases investigated. In conclusion, our study does not provide evidence that the 5-HT1A gene plays either a major or a minor role in the genetic predisposition to schizophrenia, bipolar affective disorder, or Tourette's syndrome.

Base Sequence↗
PubMed1995

Potential linkage for schizophrenia on chromosome 22q12-q13: a replication study.

In an attempt to replicate a potential linkage on chromosome 22q12-q13.1 reported by Pulver et al. [1994: Am J Med Genet 54:36-43], we have analyzed 4 microsatellite markers which span this chromosomal region, including the IL2RB locus, for linkage with schizophrenia in 30 families from Israel and Germany. Linkage analysis by pairwise lod score analysis as well as by multipoint analysis did not provide evidence for a single major gene locus. However, a lod score of Zmax = 0.612 was obtained for a dominant model of inheritance with the marker D22S304 at recombination fraction 0.2 by pairwise analysis. In addition, using a nonparametric method, sib pair analysis, a P value of 0.068 corresponding to a lod score of 0.48 was obtained for this marker. This finding, together with those of Pulver et al. [1994: Am J Med Genet 54:36-43] and Coon et al. [1994: Am J Med Genet 54:72-79], is suggestive of a genetic factor in this region, predisposing for schizophrenia in a subset of families. Further studies using nonparametric methods should be conducted in order to clarify this point.

Chromosomes, Human, Pair 22↗
PubMed1995

Linkage studies of bipolar disorder in the region of the Darier's disease gene on chromosome 12q23-24.1.

We have recently described a family in which there is cosegregation of major affective disorder with Darier's disease and have mapped this autosomal dominant skin disorder to 12q23-q24.1. This has provided an interesting candidate region for genetic studies of bipolar disorder. We have studied the segregation of seven markers spanning the Darier's disease locus in 45 bipolar disorder pedigrees and found modest evidence in support of linkage under heterogeneity for 5 of these markers. Nonparametric analyses were suggestive of linkage with a marker at the gene encoding a secretory form of phospholipase A2. Our sample has relatively low power to detect linkage under heterogeneity and independent researchers should examine markers from this region in further samples of bipolar pedigrees.

Alleles↗
PubMed1995

Relation of schizophrenia and panic disorder: evidence from a controlled family study.

The intention of this controlled family study was to evaluate reasons for comorbidity of schizophrenia and panic disorder. Observed rates of psychiatric disorders in first-degree relatives of patients and of controls were compared with rates predicted by possible hypotheses explaining comorbidity. The sample consisted of 59 patients with schizophrenia (including seven with schizophreniform disorder), 54 patients with panic disorder (with or without agoraphobia), 29 comorbid patients with lifetime diagnoses of panic disorder and schizophrenia (or schizophreniform disorder, 2 patients) and 109 controls, and their 1068 first-degree relatives. Information from clinical performance, clinical and structured interviews, and from family history was joined to establish DSM-III-R diagnoses in patients and relatives. As expected, schizophrenia and panic disorder were found to be familial. The hypothesis, that the familial load for primary panic disorders distinguished schizophrenics (4.3%) and controls (0.9%), could be verified (P < 0.01); the familial aggregation for primary panic disorders did not distinguish schizophrenics and subjects with panic disorder. However, the risk for schizophrenia was not enhanced in relatives of patients with panic disorder (0%) in comparison to controls (0.3%, P > 0.05). The observed familial aggregation pattern of psychiatric disorders in relatives of schizophrenics, panic patients, comorbid patients, and controls refers to an etiological relation of schizophrenia and panic disorder, or at least to a relationship of subgroups of these disorders.

Adult↗
PubMed1995

Molecular cloning and heterologous expression of acridone synthase from elicited Ruta graveolens L. cell suspension cultures.

Cell suspension cultures of Ruta graveolens L. produce a variety of acridone alkaloids, and the accumulation can be stimulated by the addition of fungal elicitors. Acridone synthase, the enzyme catalyzing the synthesis of 1,3-dihydroxy-N-methylacridone from N-methylanthraniloyl-CoA and malonyl-CoA, had been isolated from these cells, and the partial enzyme polypeptide sequence, elucidated from six tryptic fragments, revealed homology to heterologous chalcone synthases. Poly(A)+ RNA was isolated from Ruta cells that had been treated for 6 h with a crude cell wall elicitor from Phytophthora megasperma f. sp. glycinea, and a cDNA library was constructed in lambda 2AP. Clones harboring acridone synthase cDNA were isolated from the library by screening with a synthetic oligonucleotide probe complementary to a short stretch of sequence of the enzyme peptide with negligible homology to chalcone synthases. The identity of the clones was substantiated by DNA sequencing and by recognition of five additional peptides, determined previously from tryptic acridone synthase digests, in the translated sequence. An insert of roughly 1.4 kb encoded the complete acridone synthase, and alignments at both DNA and protein levels corroborated the high degree of homology to chalcone synthases. Expression of the enzyme in vector pET-11c in the Escherichia coli pLysS host strain proved the identity of the cloned cDNA. The heterologous enzyme in the crude E. coli extract exhibit high acridone but no chalcone synthase activity. The results were fully supported by northern blot hybridizations which revealed that the specific transcript abundance did not increase but rather decreased upon white light irradiation of cultured Ruta graveolens L. cells, a condition that commonly induces the abundance of chalcone synthase transcripts.

Acyltransferases↗