Relation between the structure of benzphetamine analogues and their binding properties to cytochrome P-450 LM2.

Twelve substrates of a homologous series of tertiary amines (type I substrates) have been reacted with cytochrome P-450 LM2 incorporated into unilamellar liposomes and in soluble form. The apparent spectral dissociation constants (Ks) of the substrate enzyme complexes and the induced high-spin shifts have been correlated with the electron density of distinct carbon atoms as monitored by 13C-NMR chemical shifts, the solubility of the amines and steric parameters of the substrate molecules. The results obtained led to the conclusion that two different intrinsic properties of the substrates can be discriminated in relation to the substrate-enzyme interaction. A diminished electron density at the nitrogen atom is accompanied by an increased binding affinity. The steric structure of the respective substrate determines its capability to shift the spin equilibrium to the high-spin state. Some characteristics of the active center of the enzyme are derived from the evidenced properties of the substrates.

Long-term outcome of chronic hepatitis B in heart transplant recipients.

BACKGROUND: Hepatitis B is common in organ transplant recipients. It adversely affects the prognosis after liver and kidney transplantation. The long-term outcome of hepatitis B virus (HBV) infection in heart transplant recipients has not been studied before. METHODS: Between July 1984 and June 1993, 436 patients underwent heart transplantation at the Hannover Medical School. A total of 345 patients survived for more than 1 year and were included in this study. Of these, 74 were found to be hepatitis B surface antigen (HBsAg)-positive during follow-up; 69 acquired HBV infection at known time points 25+/-17 months after transplantation, and 5 had already been infected before heart transplantation. Mean follow-up was 105 (range, 25-157) months. RESULTS: Patients developed significant alanine aminotransferase (ALT) elevations after HBV infection, which peaked and then remained above normal. Preinfection levels of ALT were 15.4+/-6.4 U/L, peak values were 71.2+/-47.2 U/L, and mean values after HBV infection were 28.9+/-14.6 U/L. All patients remained HBsAg-positive. Thirteen patients (18%) became HBeAg-negative during follow-up, 10 with negative quantitative HBV-DNA assays. Mean HBV-DNA levels in the remaining patients were 292+/-267 (range, 0-978) pg/ml. Thirty-four patients died during follow-up (45.9%) compared to 78/271 (28.8%) in the control group (P=0.008). Six of the HBsAg-positive patients (17.1%) died of liver failure 6.2-10.6 years (mean, 8.6) after transplantation. Histology of 25 HBsAg-positive patients more than 5 years after infection revealed severe fibrosis or cirrhosis in 14 (56%), mild fibrosis in 9 (36%), and chronic hepatitis without fibroproliferation in 2 (8%). CONCLUSIONS: Hepatitis B infection after heart transplantation leads to chronic liver disease in the majority of the affected patients, causing cirrhosis in more than 55% within the first decade after transplantation. Liver failure is a common cause of death in the infected group of patients. Active HBV vaccination is mandatory for all organ transplant candidates, in particular before heart transplantation.

Famciclovir treatment of chronic hepatitis B in heart transplant recipients: a prospective trial.

UNLABELLED: Hepatitis B may take a rapid and aggressive course in patients under immunosuppression. Nucleoside analogues have been shown to suppress viral replication effectively. To investigate the effect of famciclovir in immunosuppressed patients, 21 heart transplant recipients with chronic hepatitis B infection were included in a prospective study. PATIENTS AND METHODS: Patients have been treated with Famciclovir for a median of 14 months. Hepatitis B virus replication and biochemical parameters were regularly tested and liver biopsies were taken before treatment and after a median time of 7 months. HBV-polymerase was sequenced in all patients before therapy and in those patients who experienced virological breakthrough. RESULTS: Nineteen patients were treated for at least 6 months. Hepatitis B virus-DNA levels declined in all patients and became negative in 8 patients. Mean hepatitis B virus-DNA levels decreased from 199+/-269 to 34+/-53 pg/ml after 24 weeks (P=0.003). During treatment HBeAg became negative in five patients. Mean alanine aminotransferase decreased from 42+/-26 to 24+/-10 U/L (P=0.006). Histological analysis revealed improved inflammatory activity according to the Ishak-score in 11/16 (69%) patients. Total inflammatory activity scores decreased from 8 to 6 (median, NS), but interface hepatitis score (P=0.02) and lobular inflammation score (P=0.006) improved significantly. Median fibrosis scores fell from 5 to 3 (P=0.002). Three patients developed virological breakthrough on famciclovir after 7, 8, and 26 months of treatment showing HBV-polymerase amino acid changes L528 M, S567A, and I581K, respectively. CONCLUSIONS: Famciclovir improves not only biochemical and virological features but also hepatic inflammation and liver fibrosis in patients with chronic hepatitis B under heavy immunosuppression. Virological breakthrough may develop and requires close monitoring.

[Hepatocellular carcinoma in a lemur (Varecia variegata rubra x variegata)--a case report]. / Hepatozelluläres Karzinom bei einem Vari (Varecia variegata rubra x variegata)--ein kasuistischer Beitrag.

This case report describes a spontaneous hepatocellular carcinoma in a six years-old female lemur (Varecia variegata rubra x variegata) with widespread metastases. Potential causes of hepatic neoplasms are discussed.

Rapid quantitative PCR assays for the simultaneous detection of herpes simplex virus, varicella zoster virus, cytomegalovirus, Epstein-Barr virus, and human herpesvirus 6 DNA in blood and other clinical specimens.

Rapid diagnosis of human herpesvirus primary infections or reactivations is facilitated by quantitative PCRs. Quantitative PCR assays with a standard thermal cycling profile permitting simultaneous detection of herpes simplex virus (HSV), varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6 (HHV6) DNA were developed and validated for diagnostic use. High specificity and sensitivity were achieved and the new PCR assays correlated well with commercial PCR assays. Twenty two thousand eight hundred sixty eight PCR tests were undertaken on specimens obtained from immunosuppressed patients. DNAemia was frequent with EBV (43.5%), HHV6 (32.4%), CMV (12.8%), and VZV (12.9%). As already described for EBV and CMV, high virus loads of HHV6 and VZV were associated with clinical symptoms and poor clinical outcome, for example, three of four patients with VZV virus loads >10(5) copies/ml died. A high proportion of lower respiratory specimens was positive for EBV- (38.8%), HHV6- (29.4%), and CMV-DNA (18.2%). For CMV, infection was confirmed in 66.7% of patients by virus isolation or positive pp65 antigenaemia. Differentiation of HHV6A, -B and HSV-1, -2 by melting curve analysis revealed that HHV6A and HSV-2 represented only 1.8% and 3.3% of all positive specimens, respectively. In conclusion, these results indicate significant improvements for the early diagnosis of primary infections or reactivations of five human herpesviruses especially in immunosuppressed patients. Detection of coinfections with multiple herpesviruses is facilitated. Quantitative results enable monitoring of virus load during antiviral therapy. A standard thermal cycling profile permits time and cost effective use in a routine diagnostic setting.

Evolution of influenza polymerase: nucleotide sequence of the PB2 gene of A/Chile/1/83 (H1 N1).

The complete nucleotide sequence of the PB2 gene of influenza virus A/Chile/1/83 (H1 N1) is presented. Sequence comparison between A/Chile PB2 protein and the known PB2 sequences of the influenza strains A/WSN/33 (H1 N1), A/PR/8/34 (H1 N1), A/NT/60/68 (H3 N2), A/Kiev/59/79 (H1 N1), A/FPV/Rostock/34 (H7 N1), and B/Ann Arbor/1/66 indicates extensive amino acid homology for the influenza A virus PB2 proteins. Small clusters of basic amino acids are conserved in all PB2 proteins including the influenza B PB2 protein which has only 39% sequence homology overall to the PB2 polypeptides of type A influenza viruses. The evolutionary rate of 5.7 x 10(-3) nucleotide substitutions per site per year and 0.25% amino acid changes per year between the A/Chile/1/83 and A/NT/60/68 PB2 appears to be higher than that calculated earlier for A/NT, A/PR/8 and A/WSN. An unusually high degree of sequence change between A/Chile/1/83 and A/Kiev/59/79 PB2 polymerase was revealed and this is discussed in terms of its probable origin.

Infection chains and evolution rates of hepatitis B virus in cardiac transplant recipients infected nosocomially.

Following an outbreak of hepatitis B virus (HBV) infection amongst immunosuppressed transplant recipients, the complete sequences of the HBV-DNA isolated from nine of the affected patients were determined. The DNA sequences were found to differ from each other by a maximum of three nucleotides and belonged to the same serotype (ayw3). By contrast, the sequences differed by 18 nucleotides from the most similar HBV-DNA sequence published, indicating a common source of infection. The infection chains that have been constructed according to the base differences between the DNAs agreed well with those previously established on the basis of epidemiological data [Drescher et al. (1994) Journal of Hospital Infection 26:81-92]. At least two HBV populations, differing by one or two nucleotides, were detected in four patients, and coexisted for differing periods of time. Mutations of the core and X-peptide were not found. The data were used to calculate evolution rates of HBV DNA, both for HBV persisting within a patient and for infection chains. The rates obtained were of the same order as described previously for immunocompetent patients, indicating that the immunosuppressive medication did not influence the evolution rate. However, the evolution rate was found to decrease with increasing evolution time.

Complete nucleotide sequence of the neuraminidase gene of the human influenza virus A/Chile/1/83 (H1N1). Brief report.

The complete nucleotide sequence of the neuraminidase (NA) gene of influenza virus A/Chile/1/83 (H1N1) has been determined after reverse transcription and cloning into the plasmid pAT 153/PvuII/8. The gene is 1461 nucleotides long and codes for a protein of 470 amino acids. The overall nucleotide and predicted amino acid sequence of the A/Chile/1/83 NA exhibits a high homology with other N1 neuraminidases. Hyper-variable regions concerning A to G exchanges are discussed.

Spontaneous human herpes virus type 1 infection in a chinchilla (Chinchilla lanigera f. dom.).

A 1-year-old male chinchilla with a 2-week history of conjunctivitis suffered subsequently from neurological signs comprising seizures, disorientation, recumbency and apathy. After 3 weeks of progressive central nervous disease the animal was killed in view of the poor prognosis. A non-suppurative meningitis and polioencephalitis with neuronal necrosis and intranuclear inclusion bodies were observed at necropsy and by light microscopy. The brain stem and cerebral cortices were most severely affected. Both eyes displayed ulcerative keratitis, uveitis, retinitis and retinal degeneration, and optical neuritis. Additionally, a purulent rhinitis with focal erosions, epithelial degeneration and intranuclear inclusion bodies was present. Ultrastructurally, herpes virus particles were detected in neurons of the brain. Immunohistochemistry with antisera specific for human herpes virus types 1 and 2 resulted in viral antigen labeling in neurons, glial cells and in neuronal processes. Viral antigen was found in the rhinencephalon, cerebral cortices, hippocampus, numerous nuclei of the brain stem, single foci in the cerebellum, and in a solitary erosive lesion of the right nasal vestibulum. Viral antigen was not detected in the eyes. The virus was isolated from the CNS, and nucleic acid sequence analysis of the glycoprotein B and the DNA polymerase revealed a sequence homology with human herpes virus type 1 of 99% and 100%, respectively. The clinical signs, the distribution of the lesions and the viral antigen suggest a primary ocular infection with subsequent spread to the CNS. Chinchillas are susceptible to human herpes virus 1 and may play a role as a temporary reservoir for human infections.