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Biomedical subjects

W Köhler

Publications and source records attributed to W Köhler.

At least 37 records · Page 2Linked to original sources
PubMed2000

An X-linked gene involved in androgenetic alopecia: a lesson to be learned from adrenoleukodystrophy.

BACKGROUND: Adrenoleukodystrophy (ALD), including its adult variant adrenomyeloneuropathy (AMN), is an X-linked recessive trait characterized by progressive demyelinization of the nervous system. The gene defect involves a peroxisomal transporter protein, resulting in accumulation of very-long-chain fatty acids in the brain and other organs such as the adrenal glands. Affected men show various endocrine disorders. Moreover, disturbances of hair growth are frequently mentioned in reports on ALD/AMN. OBJECTIVE: This study was performed to delineate further the hair status and type of hair loss in men with AMN. METHODS: We examined and documented the status of hair growth in 16 men suffering from AMN. A meticulous history with particular regard to hair changes was taken from all patients and their family members. RESULTS: The age of the patients varied between 27 and 62 years, their mean age was 39.8 years. Twelve men showed male-pattern androgenetic alopecia (AGA), Hamilton grades IV-VIII, 3 men had a female-pattern AGA (Ludwig grade I or II). Ten of the patients with male-pattern AGA had reached Hamilton stage VII or VIII. The remaining scalp hair was unusually scarce and thin in 11 cases, regardless of the grade of AGA. Moreover, in 10 of 16 patients the eyelids showed pronounced madarosis. The remaining body hair was found to be normal. If present, endocrine manifestations had started prior to the onset of alopecia, and in 11 of 12 patients hair loss was apparent before neurological symptoms were noted. CONCLUSION: ALD/AMN gives rise to two different types of hair loss. Firstly, affected men show diffuse hair loss involving the entire scalp and the eyelashes. Secondly, they tend to develop AGA more frequently and earlier and in a severer form. Paradoxically, pronounced AGA is present although the patients may simultaneously show some degree of hypogonadism. Hence, the X-linked ALD mutation can be taken as a well-defined gene within the polygenic spectrum of genes responsible for AGA. This may be of theoretical importance for the elucidation of the pathogenetic pathways of AGA.

Adrenoleukodystrophy↗
PubMed1997

Leukodystrophy incidence in Germany.

Through a survey of all departments of pediatrics, neurology and neuropathology in Germany, we calculated the incidence of all major forms of leukodystrophy. Only diagnoses based on specific biochemical tests in association with typical findings and/or neuroradiologically proven white matter involvement were accepted. In accordance with these strict criteria, 617 cases of leukodystrophy were found (incidence of all forms: app. 2.0/100,000). Minimal incidence was estimated at 0.8/100,000 for adrenoleukodystrophy/adrenomyeloneuropathy (ALD/AMN), 0.6/100,000 for metachromatic leukodystrophy (MLD), and 0.6/100,000 for Krabbe disease. Thus ALD/AMN is apparently underdiagnosed in Germany. A considerable proportion of leukodystrophies could not be classified in spite of adequate diagnostic procedures in experienced centers.

Adolescent↗
PubMed1997

Testicular dysfunction in adrenomyeloneuropathy.

Adrenomyeloneuropathy (AMN) is a disorder due to a disturbance in the peroxisomal beta-oxidation of saturated very long chain fatty acids. It is characterized by symptoms of the nervous as well as the endocrine systems, especially the adrenal cortex and the gonads. We investigated the testicular function in 49 male AMN patients aged 36.2 +/- 1.5 years (range, 18.5-59 years). Twenty-four of these patients were suffering from adrenocortical insufficiency. Twenty-five AMN patients showed neurological symptoms without 'Addison's disease'. To register the frequency and the degree of gonadal impairment, LH and FSH, testosterone, free testosterone and inhibin-B were determined. Gonadotropin concentrations were significantly higher in AMN patients than in healthy controls (LH, 8.0 +/- 1.2 vs 2.77 +/- 0.11 IU/l; FSH, 10.1 +/- 1.6 vs 4.0 +/- 0.17 IU/l; P < 0.001). Serum LH was elevated in 31 patients (63.3%); 28 patients (57.1%) showed elevated serum FSH indicating deficient spermatogenesis. Mean testosterone did not differ significantly between patients and healthy controls, but mean free testosterone was significantly lower in patients than in controls (16.3 +/- 1.0 vs 28.5 +/- 1.68 pg/ml, P < 0.002). Inhibin-B concentrations did not differ between AMN patients and healthy men. The testosterone/LH ratio reflecting an impairment of the Leydig cells was significantly lower in AMN patients than in controls (P < 0.01). An impairment of the Leydig cells and/or of the Sertoli cells was evident in 81.6% of AMN patients. Twenty-one of thirty-nine patients (53.8%) admitted erectile dysfunction. These data indicate that endocrine dysfunction in AMN is not only confined to adrenocortical functions, but testicular dysfunctions also frequently occur, thus permitting the term 'adreno-testiculo-myelo-neuropathy'.

Adolescent↗
PubMed1996

Occurrence of extracellular hyaluronic acid and hyaluronatlyase in streptococci of groups A, B, C, and G.

Streptococci of serological groups A (GAS), B (GBS), C (GCS) and G (GGS) were examined in vitro using an optimized medium in respect of their ability to produce hyaluronic acid (HA) and hyaluronatlyase (HY). In this study, 614 GAS (including 123 streptococcal toxic shock syndrome strains, STSS), 247 GBS, 225 GCS and 143 GGS were investigated in qualitative and quantitative tests. Only 4% of GAS and 2.7% of GCS were able to express HA. In contrast to GAS, isolates of GCS showed a highly specific HA formation (to 1 g HA/g dry biomass). In all strains of GBS and GGS, not even a single isolate was positive for HA. HY expression was detectable in all four serological groups. In GAS, only 12.5% of strains were positive; the most common types being 22 and 4, whereas in GBS, GCS and GGS, 72.1%, 84% and 85.3% of isolates, respectively, could be reported as positive. The data suggest that the HA capsule only plays a secondary role in infections caused by GAS strains pathogenic for humans.

Bacterial Proteins↗