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Biomedical subjects

F Grünhage

Publications and source records attributed to F Grünhage.

9 recordsLinked to original sources

[Differential diagnosis of jaundice].

Jaundice is a symptom with a multitude of possible causes. These can be divided up into primary diseases of bilirubin metabolism, secondary hyperbilirubinemia in patients with liver disease, and diseases with bile duct occlusion. The major objective of the examination must be to exclude those causes that represent an acute danger to the patient, in particular cholangitis or cholecystitis. Symptoms that should cause alarm bells to ring include abdominal pain, fever and chills. When obtaining the patient's anamnesis, particular attention must be paid to lithiasis and previous operations. Laboratory findings of elevated alkaline phosphatase and gamma-GT indicate the presence of cholestasis. If an extrahepatic obstruction is suspected, ultrasonography of the upper abdomen is required.

Algorithms↗

Autoimmune hepatitis--sequel of a relapsing hepatitis A in a 75-year-old woman.

Acute hepatitis A virus (HAV) infection is a global cause of acute hepatitis. However, chronic HAV infection is unlikely. Nevertheless, there is some evidence that acute infection with HAV may trigger chronic active hepatitis which fulfils the criteria of autoimmune hepatitis (AIH). Whether AIH following HAV infection is virus specific remains unclear. Despite evidence that inherited factors may play a role in the development of autoimmunity after viral infection, the pathomechanism remains unclear. We describe a 75-year-old woman with a history of pulmonary sarcoidosis who developed AIH after acute HAV infection.

Acute Disease↗

E-cadherin expression is homogeneously reduced in adenoma from patients with familial adenomatous polyposis: an immunohistochemical study of E-cadherin, beta-catenin and cyclooxygenase-2 expression.

BACKGROUND AND AIMS: The adenomatous polyposis coli (APC) protein plays a crucial role in the regulation of beta-catenin, which is linked to the cell adhesion molecule E-cadherin. Furthermore, beta-catenin and cyclooxygenase-2 (COX-2) are both involved in the activation of nuclear transcription factors inducing cell proliferation. Germline mutations in the APC gene are the cause of familial adenomatous polyposis (FAP). To characterise the expression pattern of these proteins in FAP in comparison with sporadic adenomas, we studied 18 FAP-associated adenomas, 16 sporadic adenomas and seven normal colonic controls. METHODS: E-cadherin, beta-catenin, COX-2 expression and the proliferative index (Ki67) were assessed by immunohistochemistry (index of expressing cells / total number of cells) in adenomatous mucosa, adjacent non-neoplastic tissue and normal colonic controls. RESULTS: E-cadherin expression was significantly and homogeneously reduced in FAP adenomas (24%; 95%CI 16-32; sporadic adenomas 61%; 38-84; normal controls 98%; 96-100). Membraneous beta-catenin expression was significantly reduced in both FAP (30%; 11-49) and sporadic (42%; 19-65) adenomas (normal controls 96%; 88-104), whereas marked nuclear staining occurred in sporadic, but not in FAP adenomas. Stromal COX-2 expression and the proliferative index were increased only in sporadic adenomas (sporadic adenomas: COX-2 12%; 7-17, Ki67 24%; 15-33, FAP adenomas: COX-2 8%; 5-11, Ki67 5%; 2-9, normal controls: COX-2 4%; 2-7, Ki67 6%; 1-11). CONCLUSION: Proteins involved in cell adhesion and cell proliferation, especially E-cadherin, are expressed differently in FAP and sporadic adenoma, pointing to possible differences in the molecular pathways to adenoma.

Adenoma↗

[Drug- and toxin-induced hepatotoxicity].

The liver is essential for metabolism of drugs and exogenous toxins. Therefore, liver toxicity due to natural, domestic and industrial toxins or drugs is common but rarely recognised. Although thorough epidemiological data are missing, the number of cases with drug-induced liver toxicity is increasing, parallel to the growing number of drugs. Adverse hepatic reactions may present as acute or chronic liver damage. Independent from the cause and mechanism of liver damage, the clinical presentation may be either cytolytic or cholestatic. In addition, liver damage may be accompanied by a systemic hypersensitivity reaction against the applied agent. Drug- or toxin-induced liver damage includes vascular damage, induction of liver tumours and development of liver cirrhosis. The prerequisite for specialised treatment of drug-induced adverse hepatic reactions is establishing the diagnosis which is obtained by a thorough medical history taken by an experienced physician with a special emphasis on drug or toxin exposure. The diagnosis may be confirmed by additional diagnostic measures (e. g. liver biopsy) or the clinical course after exposure to the causing agent has been stopped. Only in a minority of cases a definite treatment may be available. Therefore, the main aim is to prevent chronic liver damage through early and correct diagnosis. Due to the extensive variety of possibly liver toxic drugs and chemical agents this aspect is a major challenge to physicians.

Antidotes↗

Haplotype study of three polymorphisms at the dopamine transporter locus confirm linkage to attention-deficit/hyperactivity disorder.

BACKGROUND: Attention-deficit/hyperactivity disorder (ADHD) is often treated using methylphenidate, a psychostimulant that inhibits the dopamine transporter. This led E.H. Cook and colleagues to consider the dopamine transporter locus (DAT1) as a primary candidate gene for ADHD. That group reported a significant association between ADHD and the 480-base pair (bp) allele of the variable number of tandem repeats (VNTR) polymorphism located in the 3' untranslated region of the DAT1 gene. This association was later replicated in additional studies. METHODS: The DAT1 gene has additional common polymorphisms in intron 9 and exon 9. We investigated the possibility of linkage of DAT1 and ADHD using the VNTR polymorphism and two additional common polymorphisms in 102 nuclear families with an ADHD proband. Using the transmission disequilibrium test, we examined the transmission of the alleles of each of these polymorphisms, as well as the haplotypes of the polymorphisms. RESULTS: We did not observe significant evidence for the biased transmission of the alleles of either the VNTR or the additional two polymorphisms when examined individually, although there was a trend for the biased transmission of the 480-bp allele of the VNTR. When we examined the haplotypes of the three polymorphisms we found significant evidence for biased transmission of one of the haplotypes containing the 480-bp VNTR allele. We also genotyped six additional DNA sequence variants of the DAT1 gene. However, these variants were not sufficiently polymorphic in our sample to be informative. Two of the DNA variants that result in an amino acid change, Ala559Val and Glu602Gly, were not observed in our sample. CONCLUSIONS: Our results support previous findings of an association between the DAT1 gene and ADHD.

Alleles↗

Dopamine D3 receptor variant and tardive dyskinesia.

In the search for genetic factors contributing to tardive dyskinesia, dopamine receptor genes are considered major candidates. The dopamine D3 receptor is of primary interest as dopamine D3 receptor knock-out mice show locomotor hyperactivation resembling extrapyramidal side-effects of neuroleptic treatment. Furthermore, Steen and colleagues (1997) recently reported an association between tardive dyskinesia and a dopamine D3 receptor gene variant. In the present study we tried to replicate this finding. We investigated 157 patients with schizophrenia or schizoaffective disorder receiving long-term neuroleptic medication who never or persistently displayed tardive dyskinesia. As advanced age is a main risk factor for tardive dyskinesia, we also compared older patients with a long duration of schizophrenia not displaying tardive dyskinesia to younger patients with a shorter duration of the illness displaying tardive dyskinesia. However, we found no evidence that the dopamine D3 receptor gene is likely to confer susceptibility to the development of tardive dyskinesia.

Adult↗

Systematic screening for DNA sequence variation in the coding region of the human dopamine transporter gene (DAT1).

The dopamine transporter (DAT) plays a central role in dopaminergic neurotransmission in the human brain. Genetic association studies have used a variable number of tandem repeat (VNTR) polymorphism in the 3'-flanking region of the dopamine transporter gene (DAT1) to implicate the DAT in the development of various neuropsychiatric disorders. In this study, we have examined the possibility that a mutation exists in the coding region of the DAT1 gene which through linkage disequilibrium accounts for the observed associations. The complete coding region, as well as exon-intron boundaries, was screened in 91 unrelated individuals including 45 patients with bipolar affective disorder and 46 healthy control individuals by the means of single strand conformation analysis. Our findings suggest that the DAT1 gene is highly conserved since we detected only two rare missense substitutions (Ala559Val, Glu602Gly) and three silent mutations (242C/T, 1342A/G, and 1859C/T) in the whole coding region. Five sequence variants were observed in intronic sequences but none affects known splice sites. The lack of frequent variants of possible functional relevance indicates that genetic variation in the coding region of the DAT1 gene is not responsible for the previously observed associations with neuropsychiatric disorders. The two rare missense substitutions were found in single bipolar patients but not in controls. Investigation of the patients' families revealed independent segregation between the Ala559Val variant and affective disorder. The Glu602Gly variant was inherited by the proband from an affected father. It therefore remains possible that Glu602Gly may be a rare cause of bipolar affective disorder.

Amino Acid Substitution↗

Polymorphisms in the dopamine D2 receptor gene and their relationships to striatal dopamine receptor density of healthy volunteers.

The density of striatal dopamine D2 receptors has been shown to vary considerably among healthy subjects. This variability might be due to genetic or environmental factors. In the present analysis we searched for relationships between dopamine D2 receptor gene (DRD2) polymorphisms and striatal dopamine D2 receptor density in vivo, as measured by positron emission tomography and [11C]raclopride in 56 healthy subjects. There was a significant association between presence of a putative functional DRD2 promoter allele (-141C Del) and high striatal dopamine receptor density (t= 2.32, P= 0.02). In agreement with some previous studies the presence of the DRD2 TaqIA1 allele was associated with measures of low dopamine receptor density (t=2.58, P=0.01). Also the DRD2 TaqIB1 allele was associated with low dopamine receptor density (t= 2.58, P= 0.01) wheras there was no significant relationship between another common silent intronic DRD2 short tandem repeat polymorphism (STRP) and striatal dopamine D2 receptor density. The results suggest that DRD2 genotypes may participate differentially in the regulation of striatal dopamine D2 receptor density in healthy human subjects. The results should be interpreted with caution because of the limited sample size.

Adult↗