Hepatitis C infection in patients undergoing liver retransplantation

BACKGROUND

There is concern that repeat orthotopic liver transplantation in patients with hepatitis C virus (HCV) infection may be associated with poor long-term survival. The specific aims of the current analysis were to determine (1) the prevalence of HCV infection in a large cohort of patients undergoing retransplantation, (2) define the impact of HCV infection on patient survival, and (3) determine the predictors of outcome of HCV-positive patients undergoing retransplantation for graft failure not caused by primary nonfunction.

METHODS

We analyzed the United Network of Organ Sharing (UNOS) registry data of 1539 adults undergoing orthotopic liver retransplantation between January 1990 and February 1996; 357 patients (23%) were HCV-positive.

RESULTS

The prevalence of HCV infection increased significantly from 6.5% in 1990 to 38.4% in 1995 (P<0.0001). Comparing the HCV-positive versus HCV-negative groups, there were no significant differences with regards to age, time to retransplantation, biochemical parameters immediately preceding retransplantation, UNOS registry status mix, or cause of graft failure (% with primary nonfunction). However, Kaplan-Meier analysis demonstrated significantly diminished survival in the HCV-positive group (P=0.0038, log-rank test; relative risk, 1.36; 95% confidence interval: 1.07-1.71). Multivariate logistic regression analysis of the subgroup of HCV-positive patients undergoing retransplantation for graft failure not caused by primary nonfunction identified preoperative serum bilirubin and serum creatinine as significant predictors of outcome. Seven of 207 (3.4%) patients undergoing retransplantation died of recurrent HCV in their second allografts.

CONCLUSION

The prevalence of HCV infection in patients undergoing retransplantation appears to have significantly increased since 1990. HCV infection is an independent risk factor for death after retransplantation. However, acceptable results are attainable in highly selected patients, i.e., those patients without severe hyperbilirubinemia and renal failure, and retransplantation remains the only viable option for patients whose allografts fail because of recurrent disease.

High mutation detection rate in the COL4A5 collagen gene in suspected Alport syndrome using PCR and direct DNA sequencing

Approximately 85% of patients with Alport syndrome (hereditary nephritis) have been estimated to have mutations in the X chromosomal COL4A5 collagen gene; the remaining cases are autosomal with mutations in the COL4A3 or COL4A4 genes located on chromosome 2. In the present work, the promoter sequence and previously unknown intron sequences flanking exons 2 and 37 of COL4A5 were determined. Furthermore, intron sequences flanking the other 49 exons were expanded from 35 to 190 to facilitate mutation analysis of the gene. Using this information, all 51 exons and the promoter region were PCR-amplified and sequenced from DNA of 50 randomly chosen patients with suspected Alport syndrome. Mutations were found in 41 patients, giving a mutation detection rate of 82%. Retrospective analysis of clinical data revealed that two of the cases might be autosomal. Although it could not be determined whether the remaining seven cases (14%) were autosomal or X chromosome-linked, it is likely that some of them were autosomal. It is concluded that PCR amplification and direct DNA sequencing of the promoter and exons is currently the best procedure to detect mutations in COL4A5 in Alport syndrome.

Quantitative assessment of HCV load in chronic hemodialysis patients: a cross-sectional survey

Recent evidence has been accumulated showing that chronic hemodialysis (HD) patients have a very high prevalence of antibodies to hepatitis C virus (HCV). In contrast, there is little information addressing the virological characteristics of HCV infection in this population.

AIM

To measure HCV viral load and to correlate this with demographic, biochemical, and clinical features of a large cohort of HCV-infected patients on chronic HD.

METHODS

394 chronic HD patients were tested by branched-DNA signal amplification assay, anti-HCV enzyme-linked immunosorbent assay 2.0, and on the basis of the aspartate aminotransferase/alanine aminotransferase (AST/ALT) activity. Multivariate analysis by ordinal logistic regression model was performed: age, gender, race, time on HD, allocation of the patients among the HD units, etiology of end-stage renal disease, HBsAg status, anti-HCV positivity, HCV genotype, and AST/ALT levels were independent factors, and viremic levels of HCV in serum were assumed as dependent variables.

RESULTS

88 (22.3%) patients showed serological and/or virological signs of HCV infection. 59 (15%) out of 394 had detectable HCV RNA in serum, the mean HCV load was 19.4 x 10(5) (95% CI, 6.06 x 10(7) to 6.2 x 10(4)) Eq/ml. According to the criteria suggested by others [J Infect Dis 1994;169:1219-1225], there were 8 (13.5%) individuals with high-titer viremia (>1 x 10(7) Eq/ml) in the subset of viremic patients. A small subset (8/394 or 2%) of individuals was seronegative, but viremic; 29 (7%) out of 394 were seropositive without detectable HCV RNA in serum. Univariate analysis showed that the frequency of anti-HCV positivity was significantly higher in viremic patients as compared with individuals with no detectable HCV viremia: 51/59 (86%) vs. 29/335 (8.6%), p = 0.0001. Serum AST and ALT levels were significantly higher in viremic patients than in individuals with no detectable HCV RNA in serum: 23.8 (95% CI 60.8-9.3) vs. 17.1 (95% CI 50.4-5.8) U/l (p = 0.009) and 14.4 (95% CI 48.9-4.3) vs. 9.8 (95% CI, 37.3- 2. 5) U/l (p = 0.008). Logistic regression analysis showed an association between HCV viremia and anti-HCV positivity (p = 0. 00001) and ALT activity (p = 0.01).

CONCLUSIONS

Hepatitis C virus infection is highly prevalent in the HD population; the viral load is relatively low, and it was associated with elevated hepatic enzyme levels and anti-HCV positivity. No other clinical characteristics were associated with HCV RNA levels. Seronegative but viremic patients were also found. Longitudinal studies with long follow-up periods are necessary to evaluate the course of HCV load over time in this population.

Ocular toxicity from ethambutol: a review of four cases and recommended precautions

AIMS

To document the clinical and demographic features of cases of ethambutol ocular toxicity, to review the literature on this subject and to critically review current guidelines for ethambutol administration.

METHODS

Cases of ocular toxicity from ethambutol were sought retrospectively at Green Lane and Wellington Hospitals between 1992 and 1995. The records of cases identified were examined.

RESULTS

Four subjects with tuberculosis developed ocular toxicity 2 1/2, 7 1/2, 8 and 12 months after starting ethambutol. Normal visual acuity returned in three cases; one patient has severe, permanent visual impairment. Language difficulties were present in three subjects.

CONCLUSIONS

Impaired communication was potentially very important in this series. Special care is needed in educating patients about ethambutol. We propose additional recommendations: 1. the usual daily dose of ethambutol should be 15 mg/kg/day, not 25 mg/kg/day; using 25 mg/kg/day (or lesser doses in the presence of renal impairment) should prompt regular formal ophthalmological evaluation (e.g. monthly) in cases with comprehension or communication difficulties; 3. both ethambutol and isoniazid should be stopped immediately if severe optic neuritis occurs. Isoniazid should be stopped if less severe optic neuritis does not improve within six weeks after stopping ethambutol.

Resolution of recurrent hepatitis B in two liver transplant recipients treated with famciclovir

Recurrent hepatitis B infection after orthotopic liver transplantation remains problematic despite prophylaxis with hepatitis B immune globulin (anti-HBs IgG). Recently, famciclovir (an oral nucleoside analog) has been shown to have potent antiviral activity against hepatitis B in vitro as well as in patients with chronic hepatitis B. We present two patients who developed recurrent hepatitis B after orthotopic liver transplantation and were treated with famciclovir, 500 mg t.i.d. Both patients subsequently responded with marked improvement in biochemical liver tests and histology, with subsequent loss of hepatitis B surface antigen. Famciclovir is a useful agent in the treatment of hepatitis B in the liver transplant recipient.

Animal models sensitive to anti-anxiety agents

Animal models of anxiety serve two primary purposes in psychopharmacological research. (i) The pharmacological profile observed in the model provides a basis which, depending on its predictive validity, permits an estimation of clinical activity. (ii) Insofar as the 'anxiety' occurring in the animal model is homologous to human anxiety disorders, it is possible to investigate the underlying cellular and molecular mechanisms. The most commonly used laboratory procedures for the identification of anxiolytic effects of drugs are described in this paper.

Generation of a genetic polymorphism in clonal populations of the bacterium Streptomyces ambofaciens: characterization of different mutator states

In Streptomyces ambofaciens, colony pigmentation is an unstable character. Very unstable mutants selected from twelve wild type (WT) subclones of S. ambofaciens ATCC23877 were investigated. This research showed that the polymorphism in colony pigmentation had distinct features. The first aspect is the coexistence of four types of colonies: pigmented colonies (Pig+), pigment-defective colonies (Pigcol-), pigmented colonies harboring pigment-defective sectors (Pigsec+) or pigment-defective papillae (Pigpap+). The second feature was revealed by the study on Pigpap+ colonies. We showed that WT progeny after 14 days of growth consisted almost totally of Pigpap+ colonies. Pigpap+ colonies were also found to be genetically different from each other. Characterization of twelve colonies presenting more than 20 papillae (Hyperpap colonies) led to the isolation of twelve mutator strains which produced at high frequency Pigcol- and Hyperpap colonies. Each exhibited a specific mutator phenotype and were distinct from each other. Such strains constituted a part of the polymorphism observed in each of the WT progeny and also generated a high variability. Finally, we showed that pigment-defective papillae were mutants and constituted a new form of genetic instability.

Targeting the PML/RAR alpha translocation product triggers apoptosis in promyelocytic leukemia cells

The t(15;17) rearrangement found in acute promyelocytic leukemia (APL) yields a fusion transcript, PML/RAR alpha. PML/RAR alpha expression is linked to leukemogenesis and to clinical sensitivity to all-trans retinoic acid (RA). Paradoxically, RA treatment causes transient complete remissions in most t(15;17) APL cases. The precise roles of PML/RAR alpha in triggering leukemia or in causing a maturation block are not yet known. This study explores directly these PML/RAR alpha functions in the growth and differentiation of APL cells using a hammerhead ribozyme to target PML/RAR alpha mRNA in the NB4 APL cell line. When the PML/RAR alpha cleaving but not the non-catalytic control ribozyme is introduced into the NB4 APL cell line, PML/RAR alpha protein expression is reduced. This catalysis signals growth suppression, cytotoxicity, and apoptosis without overcoming the maturation block found in these leukemic cells. These biologic effects depend on the selective pressure used to express the ribozyme from an episomal vector. Introduction of a non-catalytic, control ribozyme into NB4 cells caused no observed phenotype due to anti-sense activities. Expression of the catalytic or non-catalytic ribozymes in control cells lacking PML/RAR alpha mRNA yielded no apparent growth or differentiation effects. Thus, use of a hammerhead ribozyme that targets PML/RAR alpha expression in APL cells reveals the anti-apoptotic function of this translocation product and demonstrates that PML/RAR alpha cleavage is insufficient to overcome the differentiation block observed in these leukemic cells. Taken together, these findings indicate that persistent PML/RAR alpha expression is required to maintain basal leukemic cell growth and point to the therapeutic potential of targeting PML/RAR alpha in APL.

Cerebral 1H MR spectroscopy and neuropsychologic status of patients with hepatic encephalopathy

OBJECTIVE

Our objective was to assess the metabolite levels (myo-inositol [ml], choline [Cho], creatine [Cr], glutamate or glutamine [Glx], and N-acetyl-L-aspartate [NAA]) visible on 1H MR spectroscopy in patients with subclinical and mild hepatic encephalopathy before and after liver transplantation and to correlate these data with the results of neuropsychiatric tests and related clinical findings.

SUBJECTS AND METHODS

A stimulated-echo sequence was used to localize a single voxel in the parietal region. Seventeen patients and 13 healthy volunteers were investigated. Nine of the 17 patients also were investigated after liver transplantation. A battery of neuropsychologic tests also was administered to patients to assess frontal, memory, and motor functions.

RESULTS

Before liver transplantation, significant reductions in mI:Cr (51%) and Cho:Cr (11%) and a significant increase in Glx:Cr (20%) were observed in patients compared with the respective ratios in healthy subjects. Patients also were significantly impaired on neuropsychologic tests measuring frontal and motor performance, but not memory. Impairment on the frontal index showed a significant correlation with mI:Cr levels; likewise, performance on the motor index showed a significant correlation with serum ammonia levels before transplantation. MR spectroscopy after liver transplantation showed changes in the metabolite ratios compared with the pretransplantation status. Even though the Glx:Cr ratios decreased after transplantation, the mI:Cr ratio remained lower than those of healthy subjects.

CONCLUSION

The relationship of changes in the metabolite ratios recorded from a voxel in the posteromedial parietal lobe to the neuropsychologic findings before and after liver transplantation is a major finding.

Templates for design of inhibitors for serine proteases: application of the program DOCK to the discovery of novel inhibitors for thrombin

The program DOCK was used to search for novel inhibitors for alpha-thrombin. Four among the top twelve best scoring compounds from the Cambridge Structural Data Base inhibited this enzyme, and three of them inhibited alpha-thrombin in a competitive mode. These molecules are expected to serve as general templates for structural elaboration in targeting diverse serine proteases for selective inhibition.

Systemic PCP treatment elevates brain extracellular 5-HT: a microdialysis study in awake rats

THE NMDA receptor antagonist phencyclidine (PCP) has low micromolar affinity for the 5-HT reuptake site, but it is uncertain whether PCP blocks 5-HT reuptake when given systemically to rats in behaviourally stimulating doses. We here report for the first time that systemically administered PCP (5 mg/kg, s.c.) increases extracellular 5-HT levels in the rat medial prefrontal cortex (to 322%) and dorsal hippocampus (to 233%). Increases were found also when citalopram (1 microM) was included in the perfusion medium (to 184 and 180%, respectively). Extracellular 5-HIAA concentrations increased during both conditions, and extracellular GABA decreased in the dorsal hippocampus. It is concluded that systemic PCP treatment elevates extracellular 5-HT levels, probably through mechanisms other than a blockade of 5-HT reuptake.

Comparison of the properties of polymeric and C8 based materials for solid phase extraction

The extraction properties of two polymeric solid phase extraction materials, styryldivinyl benzene (SDB) and 'Oasis' have been compared with those of a base deactivated C8 bonded silica gel using a range of acidic and basic test analytes. In the case of the two polymer phases good extraction of all the test compounds from aqueous buffer was obtained over the pH range 2-10. On the C8 material, efficient extraction of the most polar acidic analyte, anisic acid, was only obtained between pH 2 and 6. The use of methanol water mixtures, or methanol water mixtures modified with either trifluoroacetic acid (TFA) or triethylamine (TEA) as eluents was investigated for the recovery of the analytes following extraction. The use of TFA or TEA as ionic modifiers strongly influenced the efficiency of the elution step. The effect of a plasma matrix on extraction efficiency was also investigated, with the result depending upon the analyte. An approach to assessing the performance of the three phases has been developed based on the percentages of methanol in the eluent resulting in the recovery of 50% of the analyte, and in determining the difference between eluents giving recoveries of 10 and 90%.

Subcutaneous granuloma caused by Mycobacterium avium complex infection in a cat

A localised subcutaneous swelling developed on the nasal bridge of a cat receiving chemotherapy for alimentary tract lymphosarcoma. Cytological and histological examination of representative samples of the lesion demonstrated pyogranulomatous inflammation and abundant acid-fast bacilli. A Mycobacterium sp was cultured from tissue excised from the lesion. Extensive testing at three reference laboratories indicated the strain was a member of the Mycobacterium avium complex. The infection was treated successfully by cytoreductive surgery and a 6 weeks course of orally administered clofazimine.

Effects of photoperiod and feeding level on perirenal adipose tissue metabolic activity and leptin synthesis in the ovariectomized ewe

Leptin is secreted by adipose tissue and plays a pivotal role in regulating both body energy homeostasis and reproductive function in rodents. Among livestock, sheep is a seasonal breeder whose reproductive period is initiated by short daylength. We show that plasma leptin and leptin gene expression in perirenal adipose tissue were decreased when ovariectomized Lacaune ewes were exposed to short days (8 versus 16 h light/d). This effect of the photoperiod occurred despite the nutritional status, with leptin levels lower in underfed than in refed ewes, and without significant changes in perirenal fat mass and adipocyte size. Plasma prolactin and leptin followed a similar pattern suggesting a relationship between the two hormones. These findings indicate, for the first time, that adipose tissue leptin is modulated by daylength independently of food intake, body fatness and gonadal activity. Furthermore, plasma non-esterified fatty acids of underfed ewes subjected to short days were more elevated than for underfed ewes on long days. On the other hand, refed ewes placed under long daylength tended to have a higher adipose tissue lipogenic activity than refed ewes on short days. We propose that these adaptations of leptin production and lipogenic activity with long photoperiod are of physiological significance for body fat deposition, which naturally occurs during long days when food is abundant. Conversely, a low leptin level during short days may enhance the sensitivity to food deprivation during the natural reproductive season, where any food shortage would decrease plasma leptin under a threshold critical for reproduction. Furthermore, in this situation, the observed enhanced ability to mobilize body fat may be related to the necessity to cope with energy shortage.

Targeting of PML/RARalpha is lethal to retinoic acid-resistant promyelocytic leukemia cells

Acute promyelocytic leukemia (APL) cells, containing the t(15;17) rearrangement, express the fusion protein, PML/RARalpha. Clinically, patients respond to all-trans retinoic acid (ATRA) through complete remissions associated with myeloid maturation of leukemic cells. This clinical ATRA response of APL is linked to PML/RARalpha expression. Unfortunately, these remissions are transient and relapsed APL is often ATRA-resistant. The role PML/RARalpha plays in the growth and maturation of these APL cells with acquired ATRA resistance has not been fully explored. This study uses an ATRA-resistant NB4 cell line (NB4-R1) to investigate the contribution of PML/RARalpha expression to ATRA resistance. Targeting of PML/RARalpha in NB4-R1 cells was undertaken using two approaches: homologous recombination and hammerhead ribozyme-mediated cleavage. Reducing PML/RARalpha protein in NB4-R1 cells rendered these cells more sensitive to ATRA. These cells were growth-inhibited in ATRA, apoptosis was induced, and there was no apparent signaling of differentiation. Sequence analysis identified a mutation in the ligand binding domain (LBD) of the RARalpha portion of PML/RARalpha. Results show that these retinoid-resistant NB4 cells require persistent PML/RARalpha expression for leukemic cell growth. Taken together, these findings can account for why these cells do not respond to ATRA and how reduction of PML/RARalpha abrogates the antiapoptotic effect it confers to these leukemic cells.

N-0923, a novel soluble dopamine D2 agonist in the treatment of parkinsonism

N-0923, a novel aminotetralin dopamine D2 agonist, was shown to effectively reverse parkinsonian symptoms in nine dopa/agonist-responsive Parkinson's disease patients. The drug was given up to 4.5 hours by continuous intravenous (i.v.) infusion using an i.v. pump. The onset of anti-parkinsonian effect was seen within minutes of the initiation of the infusion and was absent within 90 minutes of cessation of the infusion. The short elimination half-life of N-0923 (90 min) would allow for the rapid initiation of drug effect when necessary and at the same time permit the effect to be terminated quickly if necessary. The drug would be useful in situations where oral medication is not feasible or is associated with erratic absorption. The patients tolerated the drug well. Dose escalation load was limited by nausea and vomiting. It should be noted that the doses were increased until these symptoms occurred, but therapeutic effects were noted well before the side effects occurred. Using a modified Columbia scale, maximum improvement consisted of a 27-95% drop in score. Maximum response was obtained at infusion rates varying from 2-16 microg/kg per hour and at blood levels of 0.11-1.49 microg/mL.

[Self-assessment questionnaire of alcoholic craving (ECCA Questionnaire: Behavior and Cognition in Relation to Alcohol: French translation and validation of the Obsessive-Compulsive Drinking Scale]

Clinical, neurobiological and neuropsychological hypotheses suggest that the dimension of alcohol craving includes the concept of both obsessive thoughts about alcohol use and compulsive behaviors toward drinking. Anton et al. (1995) developed a 14 items self-rating scale, the Obsessive Compulsive Drinking Scale (OCDS) which includes items for assessing three dimensions: global, and the obsessive and the compulsive subdimensions. In this study, we included 156 patients, 105 men and 51 women, who met DSM IV diagnostic criteria for alcohol dependence. The mean age of our population was 39.1 +/- 11.2 years without difference between sexes. We did not found any correlation between the CAGE score and the OCDS total score or the obsessive and compulsive subscores (respectively, r = .15, r = .10 et r = .18). Moreover, we did not found any correlation between OCDS scores and mean daily alcohol consumption (r = .18, r = .16, r = .19). This could indicate that the dimension measured by the scale was somewhat independent of actual drinking. As such, it might act as an independent measure of the "state of illness" for alcohol-dependent patients. The test-retest correlation for the OCDS total score was .95 and the obsessive and compulsive subscales test-retest correlations were .93 and .89 respectively. The internal consistency of the items of the OCDS was high (alpha = .89). Principal component analysis had identified in the french version of the OCDS, three factors accounting for 63.5% of the total variance. These results indicate that the french version of the OCDS seems to validly measure a dimension of alcohol dependence. The ease of administration, reliability, and concurrent validity of the OCDS makes it particularly useful as an outcome measurement tool for various clinical therapeutic protocols in alcoholism.

Serologic responses by immunoblot following natural infection with rotavirus serotypes G1 and G4 in children

Serologic responses to proteins of rotavirus serotypes G1, P1A[8]; G2, P1B[4]; G3, P1A[8]; and G4, P2A[6] were evaluated by immunoblotting paired sera from 17 children with primary rotavirus infection. Ten children were infected with G1, P1A[8]; five with G4, P1A[8]; and two with G4, P2A[6] viruses. Anti-VP6 and anti-VP2 were seen in most responses. Homotypic anti-VP7 developed following G1 and G4 infections in 8 (80%) and 6 (86%) cases, respectively. Homotypic anti-VP4 developed in 9 (60%) cases following P1A[8] infection and in 0 of 2 cases following P2A[6] infection. Heterotypic anti-VP7 appeared against G4 (20%) and G3 (20%) following the 10 G1 infections, and against G3 (86%) and G1 (57%) following the 7 G4 infections. Heterotypic anti-VP4 occurred in only 3 (18%) children. The data show the antigenic predominance of internal proteins VP6 and VP2. Homotypic antibodies developed against VP7 but not against VP4 in most cases, while heterotypic antibodies were infrequent.

Repair of exposed hydroxyapatite orbital implant by a tarsoconjunctival pedicle flap

OBJECTIVE

This study aimed to determine a surgical method of management of exposed hydroxyapatite orbital implants.

DESIGN

Noncomparative small case series.

PARTICIPANTS

Four patients with exposures of hydroxyapatite orbital implants are described.

INTERVENTION

A superiorly based tarsoconjunctival pedicle flap is fashioned from the upper eyelid; this flap is inverted and placed over the scleral-covered, exposed hydroxyapatite orbital implant. The flap is divided as a second-stage procedure 4 weeks later.

MAIN OUTCOME MEASURE

Mucosal coverage of the previously exposed orbital implant was measured.

RESULTS

Four cases are presented with excellent postoperative results at 3 to 18 months' follow-up.

CONCLUSION

A suitably fashioned pedicle flap from the upper eyelid is an effective method of managing exposed hydroxyapatite orbital implants.