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Biomedical subjects

U Spengler

Publications and source records attributed to U Spengler.

At least 163 records · Page 9Linked to original sources
PubMed1991

Polymorphic structure of the tumor necrosis factor (TNF) locus: an NcoI polymorphism in the first intron of the human TNF-beta gene correlates with a variant amino acid in position 26 and a reduced level of TNF-beta production.

Since a dysregulated synthesis of tumor necrosis factor alpha (TNF-alpha) may be involved in the pathogenesis of autoimmune diseases, it was of interest to precisely locate the recently reported NcoI restriction fragment length polymorphism (RFLP) of the TNF-alpha region. However, by mapping of 56.8 kb of overlapping cosmid clones and direct sequencing, we could localize the polymorphic NcoI restriction site within the first intron of the TNF-beta gene and not in the TNF-alpha gene. To study whether regulatory mechanisms are affected by this polymorphism, we analyzed the TNF-alpha/TNF-beta production of phytohemagglutinin-stimulated peripheral blood mononuclear cells of individuals homozygous for the TNF-beta NcoI RFLP by ELISA and concomitant Northern blot analysis. On days 2-4 after stimulation with mitogen, the TNFB*1 allele corresponding to a 5.3-kb NcoI fragment presented with a significantly higher TNF-beta response. A mRNA analysis demonstrated that higher protein levels of TNF-beta correlate also with increased amounts of TNF-beta transcripts. No allelic association was found in respect to TNF-alpha production. To further investigate a possible allelic influence on transcription, we determined the DNA sequence of 2 kb of the 5' portion of our cloned TNFB*2 allele and compared it with the available TNF-beta sequences. By computer-aided recognition motif search of DNA binding factors, we report putative binding sites conserved between mouse and man in the 5' flanking region as well as in intron 1 of the TNF-beta gene, found also in other cytokine promoter sequences. In addition, by polymerase chain reaction amplification and sequencing of 740 bp of the 5' part of TNF-beta of individuals typed homozygously for the NcoI RFLP, we could show that amino acid position 26 is conserved as asparagine in the TNFB*1 and as threonine in the TNFB*2 sequence. A previously reported, EcoRI RFLP in the 3' untranslated region of TNF-beta does not segregate with either of the two alleles. Thus, four TNFB alleles can be defined at the DNA level.

Alleles↗
PubMed1991

Hepatitis B virus antigen-specific T-cell activation in patients with acute and chronic hepatitis B.

Since the hepatitis B virus is noncytopathic, it is generally believed that the individual specific immune response determines the course of infection. The lack of data about hepatitis B virus-specific T-cell reactions in acute infection led us to investigate the specific cellular immune response of infected individuals in terms of proliferation, and gamma-interferon and lymphotoxin production. Our results demonstrate that peripheral blood mononuclear cells (PBMNC) from patients with acute and chronic hepatitis B respond weakly to HBsAg. In contrast, patients with acute hepatitis show a vigorous response to the nucleocapsid antigen (HBcAg) in terms of proliferation and lymphokine production, while only few chronic virus carriers gave a proliferative response. Either of the antigens could activate lymphocytes to produce gamma-interferon and lymphotoxin, cytokines which may modulate antiviral immune response.

Acute Disease↗
PubMed1991

Formation of iso-ursodeoxycholic acid during administration of ursodeoxycholic acid in man.

The appearance of iso-ursodeoxycholic acid (isoUDCA; 3 beta,7 beta-dihydroxy-5 beta-cholan-24-oic acid) in serum of patients with chronic cholestatic liver disease and of healthy subjects during administration of ursodeoxycholic acid (UDCA) is reported. Comparison of the mass spectrum of the newly appearing bile acid with that of authentic 3 beta,7 beta-dihydroxy-5 beta-cholan-24-oic acid revealed its identity as the 3 beta-epimer of UDCA. The appearance of 13C-isoUDCA in serum after ingestion of 13C-UDCA proved its product precursor relationship with UDCA. The putative intermediate in the epimerization of UDCA to isoUDCA, 3-oxo-7 beta-hydroxy-5 beta-cholan-24-oic acid, was identified in serum of patients with cholestatic liver disease during treatment with UDCA. Serum concentrations of isoUDCA after 4 weeks of UDCA treatment were 1.37 +/- 0.79 mumol/l (mean +/- S.D.) in eight patients with primary biliary cirrhosis (PBC), 1.25 +/- 0.91 mumol/l in six patients with primary sclerosing cholangitis (PSC) and 3.87 +/- 0.44 mumol/l in four healthy controls. The intestinal bacterial flora as well as microsomal enzymes of the liver may be involved in the epimerization of UDCA to isoUDCA as indicated by decreased serum levels of isoUDCA under antibiotic treatment with doxycycline (100 mg/day) in healthy subjects and a correlation (r = 0.873, p less than 0.001) between the hepatic microsomal function measured by the 14C-aminopyrine breath test and the fractional conversion of applied UDCA to isoUDCA (isoUDCA/UDCA + isoUDCA) in patients with PBC or PSC. Future studies of bile acid metabolism under UDCA treatment should include measurement of isoUDCA to further elucidate its biological role.

Adult↗
PubMed1991

Allelic variation in the TNF-beta gene does not explain the low TNF-beta response in patients with primary biliary cirrhosis.

Autoimmune disorders in humans are often associated with particular alleles of major histocompatibility genes. However, the chronic inflammatory liver disease primary biliary cirrhosis (PBC) has not been found to be correlated with certain haplotypes so far. Interestingly, an impaired production of tumour necrosis factor beta (TNF-beta) upon mitogen stimulation was observed for PBC patients, especially in the immunologically active stages of the disease. Furthermore, the identification of alleles of the TNF-beta gene which differ in one unique amino acid, and in the production of TNF-beta after phytohaemagglutinin stimulation, has prompted the idea of a possible linkage between the impaired TNF-beta response in PBC and the genetic prevalence of a certain TNF haplotype. We report here a rapid method for typing the TNFB*1 and TNFB*2 genes by a standard polymerase chain reaction. PBC patients (n = 60) as well as randomized healthy controls (n = 179) of the Munich area were studied for the occurrence of the TNF alleles. No deviation was found in the PBC collective (0.7) for the TNFB*2 distribution when compared with the control (0.67).

Alleles↗
PubMed1991

Immune response of peripheral blood mononuclear cells to HBx-antigen of hepatitis B virus.

The hepatitis B virus genome encodes a transcriptional transactivator protein designated HBxAg. We have investigated whether this antigen is a target structure for human T-lymphocytes. Using recombinant HBxAg protein, we found HBxAg-specific stimulation of peripheral blood mononuclear cells in patients with acute hepatitis B virus infection (6 of 6) and chronic hepatitis B virus infection (6 of 17) but not in healthy individuals. With HBxAg-specific synthetic polypeptides, several T-cell epitopes were identified. Most were located in the carboxyterminal half of the HBxAg protein. Five T-cell clones specific for a T-cell epitope located at the carboxyterminal region of HBxAg were established and found to belong to the CD2/CD4-positive, CD8-negative subtype. These data establish for the first time HBxAg as an antigen in the cellular immune response.

Acute Disease↗
PubMed1990

Low diacylglycerol values in colonic adenomas and colorectal cancer.

The biochemical events that make colonic epithelial cells proceed along the adenoma-carcinoma sequence are not well understood. The phosphoinositol signal transduction pathway is involved in the regulation of cell growth and differentiation. To determine its role in colonic neoplasias we performed mass measurements of its second messenger sn-1,2-diacylglycerol in biopsy specimens from normal mucosa and neoplasias of the colon. Normal colonic mucosa was also investigated in patients without colonic abnormalities (n = 10). Compared with pooled diacylglycerol values from five colonic sites (100%), values in patients with a normal colon were highest in the ascending colon (120 (5)%, p less than 0.05) and lowest in the rectum (81 (5)%, p less than 0.01). Absolute diacylglycerol values in patients with normal colons (2.62 (0.16) nmol/mg protein) were not significantly different from those found in the normal mucosa of patients with colorectal neoplasias (2.45 (0.17) nmol/mg protein). Both colonic adenomas (n = 15) and colorectal carcinomas (n = 14) showed significantly decreased diacylglycerol values compared with the adjacent normal mucosa of each patient (72 (4)%, p less than 0.001, and 71 (4)%, p less than 0.001 respectively). The appreciable decrease in mass diacylglycerol values clearly distinguishes adenomas and carcinomas of the colon from the surrounding normal mucosa. This finding suggests that profound metabolic changes of the phosphoinositol signal transduction pathway occur early in the adenoma-carcinoma sequence and may be important in colonic carcinogenesis.

Adenocarcinoma↗
PubMed1989

Small intestinal transit, bacterial growth, and bowel habits in diabetes mellitus.

To investigate diabetic alterations of small intestinal transit and bacterial growth, we performed hydrogen breath tests (10 g lactulose via duodenal tube at the ligament of Treitz), bacterial cultures, and determinations of unconjugated serum bile acids in 19 patients with long-standing diabetes and 7 healthy controls. Asymptomatic diabetics had a late rise in breath hydrogen, indicating prolonged jejunal-cecal transit (86 +/- 10 min, p less than 0.05) as an early pathogenic event. Rise in breath hydrogen in symptomatic diabetics (constipation: 50 +/- 6 min; diarrhea: 41 +/- 11 min) was not significantly different from controls (57 +/- 8 min). Bacterial studies and increased unconjugated serum bile acids suggest bacterial overgrowth in some symptomatic diabetics. Bacterial overgrowth was associated more frequently (p less than 0.05) with a rise in breath hydrogen before 45 min or after 75 min. Changes in the hydrogen breath test, bacterial growth, or unconjugated serum bile acids did not correlate with gastrointestinal symptoms of diabetes.

Adult↗
PubMed1989

Clonal analysis of liver-derived T cells of patients with primary biliary cirrhosis.

Lymphocyte infiltration in liver tissue is one important histological finding in primary biliary cirrhosis (PBC). So far, functional analyses of lymphocytes in PBC have focused on circulating lymphocytes, whereas lymphocytes at the involved site, the liver, have not been examined functionally. We have established interleukin 2 (IL-2)-dependent T lymphocyte lines (TLL) and clones (TLC) from liver biopsies of 14 patients with PBC. Phenotypic analysis using the monoclonal antibodies MT910 (CD2), MT811 (CD8), and MT151 (CD4) revealed that in nine of 14 TLL cytotoxic-suppressor T cells predominated (CD8+:52-84%; CD4+:14-48%), whereas in five of 14 TLL a preponderance of the CD4+ subpopulation was found (CD4+:56-73%; CD8+:28-45%). From 10 patients 137 TLC were generated which phenotypically correlated to the TLLs. We have tested the cytotoxic potential of seven TLL and 43 TLC in LDCC (lectin-dependent cell-mediated cytotoxicity), NK (natural killing) and ADCC (antibody-dependent cell-mediated cytotoxicity) assays. All TLL and all but one CD8+ TLC tested showed high activity in the LDCC assay, reflecting the cytolytic activity of cytotoxic T cells (CTL). CD4+ clones with LDCC activity were rarely found. NK activity and K cell activity could only be found in two clones. For the first time TLC and TLL from liver tissue of PBC patients could be generated. The high cytotoxic activity displayed by T cells derived from the liver indicates an important role for this immunological mechanism in the tissue damaging process.

Adult↗
PubMed1989

Gallbladder motility before and after extracorporeal shock-wave lithotripsy.

To determine whether extracorporeal shock-wave lithotripsy of gallbladder stones alters gallbladder motility, gallbladder contraction in response to intravenous cholecystokinin was investigated by ultrasound. Twenty-one patients with symptomatic gallstones were studied before and after shock-wave lithotripsy, 12 with and 9 without concomitant litholytic therapy (combination of ursodeoxycholic acid and chenodeoxycholic acid). Gallbladder emptying was significantly delayed and less complete in both groups of patients before shock-wave treatment (with bile salts: residual volume, 51% +/- 10% and half-ejection time, 40 +/- 5 min; without bile salts: residual volume, 46% +/- 7%; half-ejection time, 30 +/- 4 min) compared with healthy controls (residual volume, 15% +/- 4%; half-ejection time, 18 +/- 2 min). Gallbladder motility was not altered in either group 1 day and 1 yr after lithotripsy. The findings indicate (a) that extracorporeal shock-wave lithotripsy has no immediate or long-term adverse effects on gallbladder motility and (b) that the defect of gallbladder motility associated with gallstone disease is not abolished by removal of the stone.

Adult↗
PubMed1988

Crohn's disease is frequently complicated by giardiasis.

Giardiasis is a common infection, and many of its symptoms are similar to those of Crohn's disease. Despite a long discussion on the role of microbiologic agents in Crohn's disease, giardiasis has never been investigated. We studied giardiasis as assessed by the occurrence of cysts in 86 patients with Crohn's disease, in 82 patients with other gastrointestinal disease, and in 52 patients without gastrointestinal disease. In addition, in 20 patients with Crohn's disease the effects of metronidazole on giardiasis and disease activity were studied. Frequency of giardiasis was 61.6% in patients with Crohn's disease, 31.7% in patients with other gastrointestinal disease, and 5.8% in the control group (p less than 0.01). Stool frequency, disease activity, and humoral signs of inflammation in patients with Crohn's disease showed no relationship to giardiasis. All but two patients treated with metronidazole became free of cysts. Crohn's disease activity index decreased in 14 of 20 patients (p less than 0.05). In conclusion, giardiasis is a common finding in patients with Crohn's disease. Treatment of giardiasis can, in individual cases of Crohn's disease, result in a quick recovery from symptoms of high disease activity.

Adult↗
PubMed1984

Carcinogenicity of dichloroacetylene: an inhalation study.

Dichloroacetylene (DCA) is a by-product of the synthesis of certain chlorinated, aliphatic hydrocarbons (e.g., vinylidene chloride). In a long-term carcinogenicity inhalation study, groups of 30 male and 30 female rats and mice were exposed to DCA vapour under the following conditions: mice, group I: 9 p.p.m. 6 h/day, 1 day/week for 12 months; group II: 2 p.p.m. 6 h/day, 1 day/week for 18 months; group III: 2 p.p.m. 6 h/day, 2 days/week for 18 months; rats: 14 p.p.m. 6 h/day, 2 days/week for 18 months; controls: under identical conditions except for addition of DCA to breathing air. The most important result is a striking increase in the formation of kidney cystadenomas of the proximal tubuli in all DCA exposed animals. The median latency time of this tumor varied widely in both mice and rats. Renal cystic adenocarcinomas were found in statistically significant numbers in male mice. In addition to kidney tumors, the development of cystadenomas of the Harderian gland in mice and of liver cholangiomas in rats were highly significant findings. DCA failed to induce liver tumors in mice. Our results confirm that DCA possesses a high carcinogenic potential, pronounced organotropic properties and distinct species differences referring to the number and nature of the induced tumors. The risk associated with handling chlorinated aliphatic hydrocarbons is essentially increased by the decomposition product DCA.

Acetylene↗
PubMed1983

Mutagenicity of dichloroacetylene and its degradation products trichloroacetyl chloride, trichloroacryloyl chloride and hexachlorobutadiene.

Dichloroacetylene (DCA) is a highly reactive compound that decomposes rapidly in contact with air into a series of chlorinated aliphatic hydrocarbons (e.g., phosgene, trichloroacetyl chloride, trichloroacryloyl chloride and hexachlorobutadiene). Experiments were performed to compare the mutagenic properties of DCA and its degradation products on the histidine-dependent tester strains TA98 and TA100 of Salmonella typhimurium. In these experiments, DCA vapour was streamed under analytical control through the bacterial suspensions. DCA is soluble in aqueous solution and was stable under the experimental steady-state conditions of the bacterial exposure. There is a linear correlation between the supply of DCA vapour and solubilized DCA in the range of 1000 and 16 000 ppm. Mutagenic response was observed with strain TA100 if the bacteria were suspended in Oxoid medium. No mutagenicity could be detected with strain TA98. DCA mixtures with acetylene, as used as stabilizer for animal experiments, were not mutagenic in either bacterial strain, irrespective of the presence or absence of S9 mix in the cell suspension. One of the degradation products of DCA, trichloroacryloyl chloride, showed pronounced mutagenic properties with and without drug-metabolizing enzymes. Other degradation products of DCA, such as trichloroacetyl chloride and hexachlorobutadiene, were not mutagenic, either in the presence or absence of liver homogenate.

Acetylene↗