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Biomedical subjects

U Spengler

Publications and source records attributed to U Spengler.

At least 109 records · Page 6Linked to original sources
PubMed1998

The lignocaine metabolite (MEGX) liver function test and P-450 induction in humans.

AIMS: The N-deethylation of lignocaine to monoethylglycinexylidide (MEGX) is partially catalysed by the rifampicin inducible P-450 isoenzyme CYP3A4. This has led to the use of the MEGX test (MEGX plasma concentrations after i.v. lignocaine) as a marker of CYP3A4 activity. To test this hypothesis, we studied lignocaine and MEGX plasma pharmacokinetics. METHODS: Ten healthy volunteers received rifampicin (600 mg day(-1)) for 6 days, resulting in a four- to sixfold increase in urinary 6beta-hydroxycortisol output. On days 1 and 7 (pretreatment), day 11 (treatment), and day 14 (48 h after rifampicin), 50 mg lignocaine i.v. was administered. MEGX concentrations at 30 min [MEGX30min] were assessed and normalised to MEGX test results after 1 mg kg(-1) lignocaine. On days 7 and 14 the lignocaine and MEGX plasma concentrations were measured over a 300 min period. MEGX test results and lignocaine and MEGX plasma pharmacokinetics before and after induction with rifampicin were compared. RESULTS: The lignocaine plasma clearance increased from 7.5+/-1.2 ml min(-1) kg(-1) before to 8.6+/-2ml min(-1) kg(-1) (P=0.026) after induction. The normalised MEGX30min concentrations increased from 61+/-14 (day 7) to 82+/-34 microg l(-1) (day 14) by a mean of 21 microg l(-1) (95% confidence interval: -3 to 44 microg l(-1)) (P=0.055). CONCLUSION: An insignificant increase of MEGX plasma concentrations was found in 10 volunteers after induction of CYP3A4 activity by rifampicin. Therefore, the MEGX test is not a sensitive marker of P-450 induction in healthy human liver.

Adult↗
PubMed1998

Sodium selenite and N-acetylcysteine in antiretroviral-naive HIV-1-infected patients: a randomized, controlled pilot study.

BACKGROUND: The aim of this work was to study the effects of combined oral administration of N-acetylcysteine (NAC) and sodium selenite (Se) on plasma glutathione (GSH), lymphocyte subpopulations and viral load in asymptomatic human immunodeficiency virus (HIV)-infected patients. METHODS: We used a prospective, randomized and controlled therapy trial with partial crossover. Twenty-four antiretroviral-naive HIV-infected outpatients at Centers for Disease Control (CDC)'93 stages I and II were randomized to receive the antioxidant combination NAC 600 mg t.i.d. and Se 500 micrograms per day for either 24 weeks (group A, n = 13) or from the end of week 12 (group B, n = 11) until the end of week 24. Thus, group B served as untreated control during the first 12 weeks. RESULTS: There was (a) a trend towards an increase in the percentage of CD4+ lymphocytes after 6 weeks (P = 0.08); (b) an increase in the CD4/CD8 ratio after 6 and 12 weeks (P = 0.02 and P = 0.04 respectively); and (c) a decrease in the absolute CD8/CD38 count and percentage of lymphocytes after 6 weeks (P = 0.002 and P = 0.033 respectively) and 12 weeks (P = 0.033, P = 0.1 respectively) in group A compared with the control period of group B. The effects observed in group A were, however, not paralleled to the same extent by group B after crossing-over to treatment after 12 weeks. In addition, erythrocyte glutathione peroxidase (GSH-Px) activity and GSH, glutathionedisulphide (GSSG) concentrations and the reduced/total GSH ratio were not affected by the treatment. Serum selenium levels increased significantly (P < 0.001) upon treatment. Viral load was not altered. CONCLUSIONS: The changes in lymphocyte subsets after NAC/Se treatment were not comparable to those after standard antiretroviral drug therapy. This, however, does not preclude per se possible benefits of antioxidant supplementation in HIV disease.

Acetylcysteine↗
PubMed1997

CD30 induction and cytokine profiles in hepatitis C virus core-specific peripheral blood T lymphocytes.

Since an efficient control of virus infections may depend on the appropriate lymphokine profile, we studied cytokine responses and CD30 induction, a recently proposed surrogate marker of type 2 cells, in 10 healthy anti-hepatitis C virus (HCV)-seropositive blood donors without viremia (group A) and in 15 patients with hepatitis C (group B). Intracytoplasmic IFN-gamma, IL-2, IL-4, and IL-10 were determined by triple-color flow cytometry in the CD3+ and CD3+/CD30+ lymphocyte subsets after stimulation of PBMC with rHCV core protein and five core-derived peptides corresponding to the four immunodominant Th epitopes C.T1 to C.T4. In group A, more type 1 cytokines were induced by the rHCV core protein and all immunodominant core peptides (p < 0.05), whereas IL-10-producing T cells were found more frequently in group B. Induction of CD30+ T cells was found almost exclusively in group B (p < 0.01). The difference in cytokine responses was due to the CD3+/CD30- T cell subset and not the CD3+/CD30+ subset, which predominantly produced both IL-10 and IFN-gamma, but only small amounts of IL-2 and IL-4. We conclude that immunodominant HCV core peptides induce preferentially type 1 cytokines in healthy anti-HCV-positive blood donors and CD30 expression in patients with chronic hepatitis C. However, in both groups, CD30+ T lymphocytes produce an intermediate Th0-like cytokine profile. Thus, chronicity in HCV infection may reflect a lack of type 1 cytokine production.

Adult↗
PubMed1997

The low-dose monoethylglycinexylidide test: assessment of liver function with fewer side effects.

The hepatic metabolism of lidocaine (1 mg/kg intravenously) to its metabolite monoethylglycinexylidide (MEG-X) is the basis of the standard MEG-X test. To reduce the lidocaine-induced side effects, we evaluated the MEG-X formation after 0.5 and 1 mg/kg lidocaine intravenously in subjects with normal (n = 5) and severely impaired liver function (n = 7) (study I). From this study, a low-dose test (MEG-X concentration 30 minutes after 50 mg lidocaine intravenously [MEG-X30min] normalized to standard MEG-X test results) was developed. Sensory side effects from this low dose and from the standard MEG-X test were compared in a double-blind, randomized, cross-over study (study II) comprising 15 individuals with normal liver function and 45 patients with cirrhosis (15 Child A, 15 Child B, and 15 Child C). In study I, MEG-X formation rate was dose-independent in patients with severely impaired liver function. In study II, normalized MEG-X test results (ranging from < or = 4 to 120 microg/L) were virtually identical to the standard test results (mean difference: -1.9 microg/L; 95% confidence interval [CI]: -5.3; 1.5 microg/L). Fewer individuals experienced side effects (30% vs. 53%) with the low-dose test (P = .0013). In a multivariate analysis, the Child-Pugh score was inversely related to the occurrence of side effects. The low-dose MEG-X test gives almost identical results to the standard MEG-X test and is associated with fewer side effects, which occur less often in individuals with more severely compromised liver function.

Adult↗
PubMed1997

Renal functional reserve and nitric oxide in patients with compensated liver cirrhosis.

To investigate the role of nitric oxide (NO) with respect to kidney function and liver cirrhosis, we evaluated renal function, as well as cyclic guanosine monophosphate (cGMP) and NOx (nitrite/nitrate [NO3-/NO2-]) as indirect markers of NO formation in plasma and urine at rest and during amino acid (aa)-induced glomerular hyperfiltration in patients with Child A liver cirrhosis and portal hypertension (n = 12), and in healthy controls (n = 10). Baseline filtration rate (GFR) and effective renal plasma flow (ERPF) were significantly lower in patients with cirrhosis than in controls (GFR: mean 88 +/- SD 16 mL/min vs. 106 +/- 15 mL/min, P = .01, ERPF: 477 +/- 93 vs. 561 +/- 72 mL/min, P = .002). In both groups amino acid (aa) infusion increased GFR, ERPF, as well as cGMP and urinary NOx. Changes in GFR were similar in cirrhotic patients and controls (28.3% +/- 14% in cirrhotics and 26% +/- 11% in controls), but the degree of aa-induced changes in ERPF was more marked in patients with liver cirrhosis (31.8% +/- 17% vs. 18.6% +/- 12%, P = .02). Plasma levels of NOx and cGMP were similar in either group at baseline and during aa infusion, whereas NOx and cGMP excretion in cirrhotics was constantly 14% to 24% lower than in the control group. We conclude that patients with compensated liver cirrhosis and portal hypertension already have an impaired kidney function. In addition our data suggest a cirrhosis-related dissociation between ERPF and GFR during aa stimulation. Further studies are warranted to find out whether a local imbalance between vasoconstrictors and vasodilators, e.g., decreased local NO formation, plays a key role for this phenomenon.

Adult↗
PubMed1997

Effect of cytochrome P450 induction on phosphorus metabolites and proton relaxation times measured by in vivo 31P-magnetic resonance spectroscopy and 1H-magnetic resonance relaxometry in human liver.

Experimental and clinical studies have led to the hypothesis that the phosphodiester signal obtained by 31P magnetic resonance (MR) spectroscopy may be a specific marker for the hepatic induction of oxidative metabolism (P450 induction) by phenobarbitone or ethanol. Systematic studies in humans are lacking. Therefore, we studied 10 volunteers who received rifampin (600 mg/d) for 6 days, resulting in a documented induction of oxidative metabolism as measured by an increase in urinary 6-beta-hydroxycortisol output in all volunteers (P = .0004). 31P-MR spectroscopy and 1H-MR relaxometry were performed before and after hepatic P450 induction. As shown by 31P-MR spectroscopy, the median phosphomonoester concentration (PME) relative to nucleoside triphosphate (NTP) increased by 21% from 0.63 (range, 0.40-0.89) before induction to 0.76 (0.49-1.67) after induction (P = .0451). The median level of phosphodiesters (PDE) relative to NTP increased by 28% from 4.82 (3.41-6.67) before induction to 6.18 (4.63-11.63) after induction (P = .0091). An increase in the level of inorganic phosphates (Pi) relative to NTP was observed, but changes were not significant. As shown by 1H-MR relaxometry, a nonsignificant trend of the liver parenchyma to shorter relaxation times was observed after P-450 induction. In conclusion, both PME/NTP and PDE/NTP ratios (measured by in vivo 31P-MR spectroscopy) increased significantly after hepatic induction with rifampin. Further clinical studies with 31P-MR spectroscopy must take into account the potential effects of P450-inducing agents.

Adult↗
PubMed1997

Liver histopathology in patients with concurrent chronic hepatitis C and HIV infection.

To investigate the influence of human immunodeficiency virus (HIV) coinfection on preexisting long-term chronic C hepatitis (HCV) 68 liver biopsies from 22 HIV/HCV-coinfected, 13 HIV- and 33 HCV-monoinfected patients and 71 livers obtained at autopsy from 26 HIV/HCV-coinfected and 45 HIV-monoinfected patients were studied by histo- and immunohistochemistry. All HIV patients had reached the advanced stage of immunodeficiency (stage III CDC), except for 3 haemophilias (stage II CDC). HCV infection was associated with a higher degree of portal, periportal and lobular inflammation-regardless of whether there was concurrent HIV infection. HIV/HCV coinfection was associated with a significantly higher rate of granulocytic cholangiolitis than HCV and HIV monoinfection (P < 0.05), a histological feature uncommon in C hepatitis. In HIV/HCV coinfection cholestasis was a predominant histological feature. HCV monoinfection and HCV/HIV coinfection were associated with the highest fibrosis index. In HIV/HCV coinfection centrilobular fibrosis was significantly more marked than in HCV monoinfection (P < 0.05), suggesting an HIV-associated fibrogenic effect. Patients with chronic C hepatitis showed a significantly increased rate of posthepatitic cirrhosis compared with the patients without HCV infection (P < 0.05). At autopsy, 10 of the 20 HIV/HCV-coinfected haemophiliacs had developed cirrhosis because of chronic C hepatitis, whereas cirrhosis was found in only 2 of 6 HIV/HCV-coinfected non-haemophiliacs (1 case of chronic B and C hepatitis, and 1 case of chronic alcohol abuse). No cirrhosis was observed in the 45 autopsy patients with HIV monoinfection. The findings suggest that HIV coinfection aggravates the course of preceding long-term chronic C hepatitis by a more marked (centrilobular) fibrosis. HIV/HCV-coinfected patients are threatened by a higher rate of posthepatitic cirrhosis-particularly in multitransfused haemophiliacs-and cholestatic hepatopathy.

Adolescent↗
PubMed1997

Serum selenium versus lymphocyte subsets and markers of disease progression and inflammatory response in human immunodeficiency virus-1 infection.

Serum selenium levels were determined cross-sectionally in 57 HIV-infected patients who were classified according to the Centers for Disease Control (CDC) 1993 classification system. Mean serum selenium levels were lower in CDC stage II (58.7 +/- 12.2 micrograms/L; p < 0.01; n = 18) and stage III (47.6 +/- 11.3 micrograms/L; p < 0.01; n = 19) HIV-infected patients, than in healthy subjects (80.6 +/- 9.6 micrograms/L; n = 48) and stage I patients (73.6 +/- 16.5 micrograms/L; n = 20). Serum selenium levels were positively correlated with CD4 count, CD4/8 ratio, hematocrit, and serum albumin (r = 0.42; r = 0.39; r = 0.48; and r = 0.45; p < 0.01, respectively) and inversely with serum levels of thymidine kinase (r = -0.49; p < 0.01; n = 49) and beta 2-microglobulin (r = -0.46; p < 0.001; n = 49). In addition, serum selenium levels in 20 randomly selected AIDS-free individuals (CDC I: n = 10; CDC II: n = 10) were inversely correlated with serum concentrations of interleukin-8 (IL-8) and soluble tumor necrosis factor receptors (sTNFR) types I and II. There was no correlation with serum immuneglobulin A and total serum protein levels. The results show that the progressive deprivation of serum selenium in HIV-infection is associated with loss of CD(4+)-cells and with increased levels of markers of disease progression and inflammatory response.

Adult↗
PubMed1997

Adenovirus-induced liver necrosis in a case of AIDS.

Adenovirus-induced liver necrosis is rare. Because the era of AIDS (acquired immunodeficiency syndrome) this entity was seen predominantly in infants suffering from inborn immunodeficiency syndromes or from iatrogenic immunosuppression because of bone marrow or liver transplantation. Here, we report a case of a 30-year-old woman with AIDS who developed fever and rapidly progressing liver failure. A frozen section from a needle biopsy of the liver allowed a quick diagnosis of viral liver necrosis. The light-microscopic and electron microscopic aspects were typical of adenovirus infection and should be known to the surgical pathologist. The diagnosis was confirmed by immunohistochemistry and DNA hybridization analysis.

Acquired Immunodeficiency Syndrome↗
PubMed1997

Successful thrombolysis after prosthetic pulmonary valve obstruction under aspirin monotherapy.

In a 22-year-old woman with recent onset of left-sided chest pain and exertional dyspnea, echocardiography revealed obstruction of a St. Jude Medical bileaflet prosthetic valve (size 23 mm) in the pulmonary position. Oral anticoagulation had been replaced for the previous 7 years by aspirin as the sole antithrombotic treatment. The valve had been inserted 16 years ago for pulmonary atresia. Valve function was restored by systemic application of 9 million units of urokinase.

Adult↗
PubMed1997

Anomalous expression of costimulatory molecules B7-1, B7-2 and CD28 in primary biliary cirrhosis.

BACKGROUND: T lymphocytes require two important signals for efficient activation: 1) recognition of antigens bound to self major histocompatibility complex antigens, and 2) simultaneous stimulation via so-called costimulatory molecules. Interaction of the costimulatory B7 molecules on antigen presenting cells with CD28 on T lymphocytes appears to be particularly important, as it modifies secretion of cytokines, especially interleukin 2. In primary biliary cirrhosis biliary epithelial cells aberrantly express major histocompatibility complex class II antigens and may function as antigen presenting cells. METHODS: We studied expression of HLA-DR, B7-1, B7-2 and CD28 on cryostat liver sections in 16 patients with primary biliary cirrhosis, three patients each with autoimmune hepatitis and primary sclerosing cholangitis and nine patients with chronic viral hepatitis (five hepatitis B, four hepatitis C) using mouse monoclonal antibodies in an indirect immunoperoxidase technique. RESULTS: In advanced primary biliary cirrhosis, HLA-DR was found on 57% of bile ducts, B7-2 on 5% of bile ducts, and B7-1 could not be detected on any bile duct. Neither B7-1 nor B7-2 was seen on bile ducts in the four patients with early primary biliary cirrhosis. HLA-DR+ bile ducts also lacked expression of B7 molecules in autoimmune hepatitis. In contrast, HLA-DR, B7-1 and B7-2 were expressed simultaneously on professional antigen presenting cells such as macrophages in epitheloid granulomas. CONCLUSION: HLA-DR+ biliary epithelial cells in primary biliary cirrhosis insufficiently co-express B7-1 or B7-2 molecules. Therefore, they must either use different costimulatory molecules, or otherwise are deficient in lymphocyte activation. Since recognition of antigen in the absence of B7-CD28 interaction may lead to anergy of lymphocytes, this might contribute to the impaired cytokine secretion found in primary biliary cirrhosis.

Antigens, CD↗
PubMed1997

Cholestasis associated with mesalazine therapy in a patient with Crohn's disease.

BACKGROUND/AIMS: Mesalazine is a widely prescribed medication, developed as an alternative to sulfasalazine in the treatment of inflammatory bowel disease. In contrast to sulfasalazine, there are only a few case reports on its causing hepatic injury. We here report on a patient with cholestasis after mesalazine therapy for Crohn's disease of the ileum. METHODS/RESULTS: The patient, a 30-year-old man, developed clinical signs of severe hepatic injury 4 months after treatment with mesalazine (4 g/day) including biopsy-proven hepatocellular cholestasis with minimal focal mononuclear inflammatory infiltration. Contrary to previous reports, no symptoms of generalized hypersensitivity were seen. The patient's illness was resolved by discontinuing the mesalazine treatment and he recovered completely in 40 days. CONCLUSIONS: This case reinforces the possibility of a causal relationship between mesalazine treatment and toxic hepatic injury without systemic hypersensitivity.

Adult↗
PubMed1997

Semiquantitation of intrahepatic MDR3 mRNA levels by reverse transcription/competitive polymerase chain reaction.

BACKGROUND/AIMS: Knockout mice lacking mdr2, the murine analogue of human MDR3 P-glycoprotein, develop chronic non-suppurative cholangitis. Recently, a deficiency in MDR3 messenger RNA (mRNA) has been reported in a subtype of progressive familial intrahepatic cholestasis. Thus, reduced MDR3 gene expression could be involved in human cholestatic liver diseases. METHODS: We developed a sensitive and specific reverse transcription/competitive polymerase chain reaction for the semiquantitation of intrahepatic MDR3 mRNA levels. Using this method we determined the MDR3 mRNA levels in 52 liver specimens from primary biliary cirrhosis (n=11), chronic hepatitis B (n=5), chronic hepatitis C (n=14), non-cholestatic cirrhosis (n=9) and controls (n=13). RESULTS: MDR3 mRNA was detected in all specimens with some variation in mRNA levels. No significant differences in the mean MDR3 mRNA levels were present between the groups studied, including normal controls. CONCLUSIONS: We found no evidence for deficient or severely reduced intrahepatic MDR3 mRNA in primary biliary cirrhosis, nor were mRNA levels altered significantly by virus-induced inflammation or by cirrhosis. The reverse transcription/competitive polymerase chain reaction assay described here should be a useful tool in the semiquantitative study of MDR3 mRNA levels in small tissue specimens.

ATP Binding Cassette Transporter, Subfamily B↗
PubMed1997

Serum selenium, plasma glutathione (GSH) and erythrocyte glutathione peroxidase (GSH-Px)-levels in asymptomatic versus symptomatic human immunodeficiency virus-1 (HIV-1)-infection.

OBJECTIVES: Antioxidant defense status was investigated in HIV-infected patients by measuring serum selenium, erythrocyte glutathione peroxidase (GSH-Px) activity, plasma thiol (-SH) and glutathione (GSH) concentrations along with the assessment of the clinical stage and surrogate markers of HIV-disease. DESIGN, SETTING AND SUBJECTS: Serum selenium levels were determined cross-sectionally in 104 sequentially selected HIV-infected patients (83 outpatients and 21 patients with ongoing AIDS defining events). The patients were classified into three stages of the disease, I, II and III according to the 1993 Centers For Disease Control (CDC) classification system for HIV-infection. GSH-Px activities, plasma SH and plasma GSH concentrations were determined in a subset of 24 patients at stage I and 12 patients at stage III with an active AIDS-defining disease. RESULTS: Mean serum selenium levels were lower in CDC stage II (68.7 +/- 20.9 micrograms/l; P < 0.01; n = 34) and stage III (51.4 +/- 14.7 micrograms/l; P < 0.01; n = 37) HIV-infected patients than in healthy subjects (89.2 +/- 20.9 micrograms/l; n = 72) and stage I patients (82.3 +/- 20.5; microgram/l; n = 33). Serum selenium levels were positively correlated with CD4-count (r = 0.42; P < 0.001; n = 104) and inversely with levels of soluble tumor necrosis factor receptors type II (r = -0.58; P < 0.01; n = 35), neopterin (r = -0.5; P < 0.001; n = 80) and beta 2-microglobulin (r = -0.4; P < 0.001; n = 94). Hepatitis C virus (HCV) and HIV-coinfected patients at CDC stages I and II showed markedly lower selenium concentrations compared to HIV-infected patients without concomitant HCV-infection. Serum selenium and GSH-Px activity in hospitalized AIDS patients was significantly lower as compared to asymptomatic patients and healthy subjects, whereas plasma SH and GSH concentrations were lower in both, asymptomatic -and AIDS-patients, than in the controls. CONCLUSION: The results show that stages I-III of HIV-disease are characterized by significant impairments of antioxidative defenses provided by selenium, GSH-Px, SH-groups and GSH.

Adult↗
PubMed1997

Inadequate erythropoietin response to anaemia in HIV patients: relationship to serum levels of tumour necrosis factor-alpha, interleukin-6 and their soluble receptors.

Severe anaemia is a frequent complication in advanced HIV infection. In our study we investigated the interaction between cytokine network, HIV infection and erythropoietin (Epo) response with increasing anaemia levels. No correlations could be established between circulating tumour necrosis factor (TNF)-alpha and any of the examined parameters. However, a negative correlation was found between haemoglobin values and soluble TNF receptor levels (sTNF-R-I: r = -0.54; P < 0.001; sTNF-R II: r = -0.47; P < 0.001) as well as interleukin-6 levels (r = -0.29; P < 0.01). In contrast, no significant increase in log[Epo], counterbalancing haemoglobin decline and paralleling the rise in sTNF receptors, was found. In patients classified as stage III, according to the Centers for Disease Control (CDC) classification, the erythropoietin response was significantly more impaired than in patients from CDC groups I and II (P < 0.01). The results of this study suggest that similar to its action in vitro, activation of the TNF/TNF-R system may impair erythropoietin production in HIV-associated anaemia. Due to the brief half-life of TNF-alpha, this activation is particularly reflected by elevations of soluble TNF receptor levels.

Adult↗