Alteration in the redox state of plasma in heart-transplant patients with moderate hyperhomocysteinemia

Hyperhomocysteinemia has recently been suggested to contribute to the progression of the so-called chronic rejection or cardiac allograft vasculopathy (CAV) in heart-transplant patients in which the major determinant of the increase in homocysteine (Hcy) was the progressive decline of renal function. The exact mechanisms of tissue injury by Hcy is unknown, but some aspects of its toxicity have been related to its capacity for altering the redox state of plasma and forming protein adducts by intermediate lactone. To study the relationships between Hcy levels and variations in the redox state governed by thiols, plasma levels of Hcy, cysteine, glutathione, cysteinylglycine, and corresponding disulfides and protein-mixed disulfides were evaluated in subjects with moderate hyperhomocysteinemia represented by heart-transplant patients with (HTRF) and without (HT) renal failure, as well as patients with renal failure of different origin (RF), and compared with those of a control group (C) of normal subjects matched for age and sex. Plasma levels of Hcy and the corresponding protein mixed disulfides increased progressively in HTs, RFs, and HTRFs with respect to control. These changes were correlated with cysteine variations (as cystine and protein-mixed disulfides) but not with glutathione or cysteinylglycine that varied only as disulfides with a similar tendency. Moreover, an alteration in the plasma redox was evidenced by the decrease in thiol/disulfide ratios of cysteine, Hcy, and cysteinylglycine. In all groups, cysteine was directly correlated with Hcy but not with glutathione or cysteinylglycine, which in turn were correlated each other. Therefore levels of plasma cysteine were more linked to Hcy than to metabolism of glutathione. The clinical meaning of cysteine changes remains undefined and requires further study.     

Equilibrative nucleoside transporter 1 genotype, cytidine deaminase activity and age predict gemcitabine plasma clearance in patients with solid tumours

AIM

Gemcitabine (GEM) enters normal and tumour cells via concentrative (CNT) and equilibrative nucleoside transporters (ENT) and is subsequently deaminated to the inactive difluorodeoxyurine (dFdU) by cytidine deaminase (CDA). The aim of our study was to ascertain whether the nucleoside transporter genotype and the CDA activity phenotype can predict total GEM plasma clearance.

METHODS

Forty-seven patients received GEM 1000–1250 mg m⁻² i.v. over 30 min. Plasma concentrations of GEM and dFdU were measured and individual pharmacokinetic profiles were determined. CDA activity was measured ex vivo in plasma samples. The two most common hENT1 and hCNT1 polymorphisms were determined from genomic DNA.

RESULTS

Multivariate analysis revealed that GEM plasma clearance (CL) was positively correlated with the end of infusion dFdU : GEM ratio (P < 0.0001), which is a marker of in vivo CDA activity. The ENT1 genotype characterized by high transport capacity (G/G) and age were inversely correlated with CL (P= 0.027 and 0.048, respectively). A strong correlation was found between end of infusion GEM concentration and area under the concentration–time curve from time 0 to infinity (AUC(0,∞)) (r²= 0.77).

CONCLUSIONS

Our results confirm the role of CDA and age on the interindividual variability of GEM CL and show the contribution of the hENT1 genotype for the first time.     

Essential amino acid supplementation decreases liver damage induced by chronic ethanol consumption in rats

The liver sustains the greatest damage from ethanol (EtOH) abuse. EtOH and its metabolites impair hepatocyte metabolism, causing intracellular accumulation of proteins and lipids and increasing radical oxygen species production. These processes are toxic to the mitochondrial respiratory chain and to mitochondrial DNA. We have recently shown that supplementating the diet of rodents with an essential amino acid-enriched mixture (EAAem) significantly increases mitochondrial mass and number in cardiac and skeletal muscles and improves mitochondrial function in aged animals. Thus, in this study we sought to test whether EAAem supplementation could reduce EtOH-induced liver damage. Groups of adult male Wistar rats were fed a standard diet and water ad libitum (the control group), drinking water with 20 percent EtOH (the EtOH group), or drinking water with 20 percent EtOH and EAAem supplementation (1.5 g/kg/day) (the EtOH+EAAem group) for 2 months. The blood EtOH concentration was measured, and markers for fat (Oil-Red-O), mitochondria (Grp75, Cyt-c-ox), endoplasmic reticulum (Grp78), and inflammation (Heme Oxigenase 1, iNOS, and peroxisomes) were analyzed in the liver of animals in the various experimental groups. EAAem supplementation in EtOH-drinking rats ameliorated EtOH-induced changes in liver structure by limiting steatosis, recruiting more mitochondria and peroxisomes mainly to perivenous hepatocytes, stimulating or restoring antioxidant markers, limiting the expression of inflammatory processes, and reducing ER stress. Taken together, these results suggest that EAAem supplementation may represent a promising strategy to prevent and treat EtOH-induced liver damage.     

Effects of combination treatment with mood stabilizers and mirtazapine on plasma concentrations of neuroactive steroids in depressed patients

Antidepressants such as SSRIs or mirtazapine have been demonstrated to increase the concentrations of 3alpha-reduced neuroactive steroids throughout several weeks of treatment. However, no data are available on the impact of mood stabilizers such as lithium or carbamazepine on neuroactive steroid levels in depressed patients. Study 1 was performed in 26 drug-free depressed inpatients who were treated with either mirtazapine monotherapy (n=13) or combination therapy with mirtazapine and addition of lithium (n=13). Twenty drug-free depressed inpatients were included in study 2, receiving either mirtazapine monotherapy (n=10) or combination treatment with mirtazapine and carbamazepine (n=10). Plasma samples were taken weekly at 0800 h in the morning and quantified for neuroactive steroids by means of combined gas chromatography/mass spectrometry analysis. In study 1, the mirtazapine-induced rises in 3alpha,5alpha-tetrahydroprogesterone and 3alpha,5beta-tetrahydroprogesterone were abolished by additional lithium administration, as compared to mirtazapine monotherapy. In study 2, the mirtazapine-evoked increase in 3alpha,5alpha-tetrahydroprogesterone was reversed after additional administration of carbamazepine, presumably due to lowered mirtazapine levels after induction of cytochrome P450 enzymes. Apparently, the mood stabilizers lithium and carbamazepine do not enhance but rather reverse the increase in plasma concentrations of 3alpha-reduced neuroactive steroids in depressed patients pretreated with antidepressants such as mirtazapine.     

Residential facilities for older people in Italy: a five-region survey

BACKGROUND AND AIMS: To survey all Residential Facilities (RFs) for older people (more than 50% residents over 65 years of age) in five Italian regions (Calabria, Sardinia, Sicily, Umbria, Veneto), and to evaluate their logistic and organizational characteristics and staff and resident features. METHODS: Structured interviews with RF managers; selected RFs operating in five regions. RESULTS: A total of 853 RFs were operating in the five regions, with an average of 198.0 beds per 10,000 older people - a rate showing marked regional variability. The number of RFs actually surveyed was 754 (88.4% of sample pool). The mean number of RF beds was 59.8 (+/-65.0; median: 34), and the great majority (96%) had 24-hour staff cover. A large proportion (29%) were managed by local municipal authorities, religious non-profit associations (approx. 24%) and other non-profit organizations (approx. 21%). In the RFs 24,456 workers were employed; the number of staff per facility also showed great variability. The mean number of workers directly involved in resident care was 27.8 (+/-39.0; range: 1-331); the median number of staff members was 14, and the resident/staff ratio was 2.1. These 754 RFs hosted 42,687 residents, with an average of 53.5 (+/-58.5) older people in each facility, and 3.2 residents below the age of 65. The mean age of the entire resident sample was 79.3 years (+/-5.2) and there was a high proportion of residents with neurological (including dementia), psychiatric and medical disorders. CONCLUSIONS: The five regions varied considerably in residential bed provision; many other RF characteristics, including staff/resident ratios, showed similar variability. Most RFs hosted older people with a variety of neurological, psychiatric and medical disorders. Future phases of the project will aim at shedding light on many other features in these institutions, which care for 2.1% of the older population in Italy and may serve even greater proportions of older people in the future.     

Lateral temporal lobe epilepsies: Clinical and genetic features

Lateral temporal epilepsies are still a poorly studied group of conditions, covering lesional and nonlesional cases. Within nonlesional cases, autosomal dominant lateral temporal epilepsy (ADLTE) is a well-defined, albeit rare, condition characterized by onset in adolescence or early adulthood of lateral temporal seizures with prominent auditory auras sometimes triggered by external noises, normal conventional magnetic resonance imaging (MRI), good response to antiepileptic treatment, and overall benign outcome. The same phenotype is shared by sporadic and familial cases with complex inheritance. Mutations in the LGI1 gene are found in about 50% of ADLTE families and 2% of sporadic cases. LGI1 shows no homology with known ion channel genes. Recent findings suggest that LGI1 may exert multiple functions, but it is not known which of them is actually related to lateral temporal epilepsy.     

Role of the polycomb repressive complex 2 in acute promyelocytic leukemia

Epigenetic changes are common alterations in cancer cells. Here, we have investigated the role of Polycomb group proteins in the establishment and maintenance of the aberrant silencing of tumor suppressor genes during transformation induced by the leukemia-associated PML-RARalpha fusion protein. We show that in leukemic cells knockdown of SUZ12, a key component of Polycomb repressive complex 2 (PRC2), reverts not only histone modification but also induces DNA demethylation of PML-RARalpha target genes. This results in promoter reactivation and granulocytic differentiation. Importantly, the epigenetic alterations caused by PML-RARalpha can be reverted by retinoic acid treatment of primary blasts from leukemic patients. Our results demonstrate that the direct targeting of Polycomb group proteins by an oncogene plays a key role during carcinogenesis.     

Renal transplantation in patients with Balkan endemic nephropathy

BACKGROUND: Balkan endemic nephropathy (BEN) is a chronic tubulointerstitial disease prevalent in Croatia, Romania, Bulgaria, Bosnia and Herzegovina, and Serbia. In addition to renal disease, an increased incidence of upper urothelial carcinomas (UUCs) has been observed in the foci of BEN. Carcinoma may occur alone or in combination with BEN. Immunosuppression is associated with an increased risk for development of different malignancies. There are no data in the literature about the outcome of patients with BEN after transplantation. METHODS: We performed a retrospective evaluation of the database and review of the charts and pathology reports of 601 renal transplant recipients treated at our institution. RESULTS: From January 1995 to December 2004, kidney transplantations were performed in nine patients with BEN. One-year graft survival was 100%. A man, who was transplanted in 1997 died 2 years after transplantation with a functioning graft due to disseminated cancer from the pelvis of his own kidney. A female patient developed UCC 2 years after transplantation. They were both treated with a bolus of methylprednisolone before transplantation, because of four HLA-mismatches. A male patient developed UCC in the native and transplanted kidneys. He underwent a native nephroureterectomy with partial nephroureterectomy of transplanted kidney. His graft function was preserved with decreased immunosuppression. Three years later a urinary bladder carcinoma was discovered on a regularly performed multislice computed tomography. One patient developed a skin malignancy. Other patients have had uneventful posttransplantation courses with excellent graft function. Thus, 33.3% of patients with BEN developed UUC, compared with a 0.67% prevalence of urinary tract tumors among transplanted patients with other causes of end-stage renal disease. CONCLUSION: Patients with BEN are at increased risk for the development of UCC after transplantation. Regular screening for early detection of malignancy is mandatory. Longer follow-up and results from other transplant centers are needed to further investigate the relationship between BEN and UCC after renal transplantation.     

Outcome After Renal Transplantation in a “Senior” Program: The Croatian Experience

Background

The Eurotransplant “senior” program allocates kidneys from elderly donors to patients >65 years old. It aims to increase the number of renal transplantations. Kidneys are allocated locally without human leukocyte antigen (HLA) matching to decrease the cold ischemia time. Croatia has introduced its own “senior” program based on HLA matching. We compared results with those from Eurotransplant.

Methods

We identified and prospectively followed all patients aged of ≥65 years who underwent a first renal transplantation. We recorded their HLA matching, cold ischemia time, renal function, surgical and medical complications, and duration of hospitalization.

Results

Through October 2007, 22 elderly patients received an allograft from donors who were >65 years old. There were 8 female and 14 male patients of mean age at transplantation of 67.4 years. Mean donor age was 66 years. The number of HLA mismatches ranged from 1 to 5, and cold ischemia time from 7 to 15 hours. One-year patient survival was 95.4%, and graft survival was 81.8%. Delayed graft function, defined as the need for dialysis for >7 days after transplantation, occurred in 63.6% of patients. Older recipients required prolonged hospitalization after transplantation (45 days; range, 16-131). Frequent posttransplant complications included posttransplant diabetes mellitus in 1 patient, delayed wound healing in 5 patients, and lymphocoel in 2 patients. Maligancies occurred in 3 patients, neoplasm of the native kidney, posttransplant lymphoproliferative disease, and skin cancer. One patient experienced acute rejection that was successfully treated with steroids. Seventeen patients experienced 20 viral infections. There was only 1 serious infection (pulmonary tuberculosis). The major problems were cardiovascular complications which occurred in 40.9% of patients.