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Hepatitis B (HBV) and hepatitis C (HCV) viral infections often recur after orthotopic liver transplantation (OLT), but viral infections acquired with OLT have not been widely investigated. The aim of the study was to evaluate the incidence, evolution, and diagnostic problems of de novo HBV and HCV infections in liver transplant recipients with long-term follow-up. Altogether 121 transplant recipients entered the study. HBV, HDV, and HCV infections were diagnosed by means of serology and the polymerase chain reaction (PCR). Three patients became hepatitis B surface antigen (HBsAg)-positive after OLT, all of whom showed signs of persistent viral replication. Twelve patients became anti-HCV-positive after OLT: After clearance of passive antibodies, active anti-HCV seroconversion was usually delayed. The viral genome was detected in 9 of 12 patients, with fluctuations of viremia during their follow-up. The other three patients, who were HBsAg-positive before and after OLT, were repeatedly HCV-RNA-negative despite persistent anti-HCV reactivity. Four pre-OLT HBsAg-positive patients had evidence of HBV-related liver transplant disease. The remaining 8 of 12 patients experienced repeated alanine aminotransferase increases more than two times normal after transplant. De novo infections due to primary hepatotropic viruses were frequent after OLT in our experience. Early diagnosis of infection, especially when the HCV is involved, may be problematic and should be taken into account in patients showing persistent aminotransferase abnormalities. Monitoring viral markers and accurate evaluation of biopsy specimens are mandatory. The interference between HBV and HCV might play a role in the replicative cycle of one or both viruses in co-infected patients.

A particular mitochondrial DNA (mtDNA) deletion, the so-called "common deletion", accumulates progressively with age in human post-mitotic cells. We investigated the presence of age-related mtDNA deletions in mouse heart and, according to the free-radical theory of aging, the potential involvement of reactive oxygen species (ROS). Hearts from young, adult and old male Balb/c mice were homogenized and centrifuged in order to discard nuclear DNA. The supernatant was then utilized to prepare mtDNA by SDS-proteinase K digestion. The presence of a mtDNA4236 deletion was estimated by PCR analysis, by separating the amplificated segment on agarose gel. The incidence of the mtDNA4236 deletion was 16%, 28% and 78% in young, adult and old mice, respectively. 8-hydroxy-2'-deoxyguanosine (8-OH-dG), a marker of DNA oxidation, was also determined by HPLC-electrochemical analysis. 8-OH-dG was not detectable in young mice, while its concentrations (moles 8-OH-dG/10(6) moles dG; mean +/- SD) were 59.0 +/- 1.41 and 31.0 +/- 4.24 (p < 0.02) in adult and old mice, respectively. These data indicate that a mtDNA4236 deletion is progressively associated with aging in mouse hearts, and that oxidative damage to mtDNA is greater in middle-aged than senescent animals.

Biochemical and structural changes occurring in the myocardium with aging are mainly resulting from the association of a general tissue atrophy with the hypertrophy of the remaining myocytes. Whilst hypertrophy seems to be a compensatory process to the loss of cardiomyocytes and to a mild systolic hypertensive condition that accompanies elderly people, atrophy should be the modification more closely related to aging 'per se.' In support to the free radical theory of aging, several signs of oxidative damage have been shown in the aged heart, such as lipofuscin accumulation, decreased phospholipid unsaturation index, greater formation of both hydrogen peroxide and 8-hydroxy-2'deoxyguanosine. As a compensatory reaction, the activities of the main oxygen-radical scavenger enzymes are stimulated in the mitochondria of aged rat heart. Endothelium-mediated vasoregulation is more susceptible to oxidative stress in aged with respect to young rats, suggesting that also the vasculature can be negatively influenced by the oxygen free radicals generated during aging. The possible primary role of oxygen free radicals in the development of myocardial atrophy is also discussed.

Acetylcholine-induced, endothelium-dependent relaxation of norepinephrine-precontracted aortic strips, was severely impaired after exposure to a hypoxanthine/xanthine oxidase reaction generating oxygen radicals. This effect was more evident in aortic strips of aging rats (24 months old) in comparison to young rats (3 months old). The addition of authentic .NO (1 microM) completely relaxed aortic strips exposed to oxidative stress both in young and aging rats. In vitro EPR measurements showed that the .NO signal was reduced by enzymatic O2.- generating reaction. The activity of a partial purified preparation of constitutive NO synthase from rat cerebellum was significantly decreased after exposure to exogenous oxygen radicals. Pretreatment of aortic strips with 100 microM alpha-tocopherol-phosphate, produced a significant improvement of acetylcholine-dependent relaxation in the aortic strips exposed to oxidative stress, particularly in the aged vessel. The content of malondialdehyde in aortic tissue did not change after oxidative stress or alpha-tocopherol pretreatment. Alpha-tocopherol was unable to recover the NO synthase activity depressed in vitro by hypoxanthine/xanthine oxidase reaction. This study confirms that an oxidative stress impairs the endothelium-mediated vasodilation. Alpha-tocopherol pretreatment protects the vessel against this damage. The mechanism of action of alpha-tocopherol is unknown, but seems unrelated to an antioxidant activity.

The Drosophila melanogaster ecd1 mutation causes a severe temperature-sensitive deficiency in the titre of the steroid hormone ecdysone. This mutation was used to investigate the role of ecdysone in both the transcription of the genes mapped at the 3C11-12 intermoult puff region and the puff formation. Thoroughly synchronized ecd1 larvae were shifted to the non-permissive temperature at various times of the development; after 24 or 48 h, the levels of the transcripts derived from Sgs-4, Pig-1 and ng-1, the three genes located at the 3C11-12 polytene bands, were determined. The results showed that the levels of the transcripts encoded by Pig-1 and ng-1 are unaffected by the drop in the ecdysone titre occurring in non-permissive conditions whereas the amount of Sgs-4 mRNA is greatly reduced. These data clearly indicate that transcription of the three genes mapped within the puff region is affected differently by the hormone. Furthermore, ecd1 larvae cultured at the non-permissive temperature show a prominent puff at the 3C11-12 polytene bands, indicating that ecdysone is not essential for puff induction and that puff size is not simply correlated with high-level Sgs-4 transcription.

The D. melanogaster dunce gene is involved in both the learning and memory processes of the fly. The gene encodes for a cAMP-specific phosphodiesterase, a function playing a central role in the regulation of the intracellular cAMP level. Molecular cloning of dunce has so far not been completely achieved, although it is known that the gene encodes a large set of RNAs and has a complex organization, extending for more than 140 kilobases and containing several genes within its introns. Here we report the isolation and the characterization of 21/7, a cDNA clone representative of a novel dunce splicing pattern. The nucleotide sequence of this clone led to the identification of a dunce exon included in at least one transcript so far uncharacterized.

We have explored the expression of gap junctional proteins and corresponding mRNAs by insulin-producing B-cells of native rat pancreas and of a transplantable rat insulinoma. By immunostaining cryostat sections (indirect immunofluorescence) and crude membrane preparations (Western blots) with antibodies against connexins 26, 32, and 43 and by hybridizing total islet and insulinoma RNA (Northern blot) with cRNAs for the latter two proteins, we have found that normal and tumoral B-cells express connexin 43 but do not show detectable levels of either connexin 32 or 26. By evaluating the conductance (dual patch-clamp whole-cell recording) and permeability of junctional channels (microinjection of Lucifer yellow), we have found that control B-cells show low levels of electrical and dye coupling in only a portion of the pairs studied. By studying B-cells of glibenclamide-treated rats, we have found that sustained stimulation of insulin release in vivo is associated with a two-fold increase in the level of connexin 43 gene transcripts and in the incidence of both ionic and dye coupling. These observations indicate that (1) connexin 43 is a major component of communicating channels between insulin-producing cells; (2) some but not all B-cells are electrically coupled by low conductance junctional channels; and (3) connexin 43 gene transcripts and incidence of junctional coupling are modulated in parallel during sustained stimulation of B-cell functioning in vivo.

The molecular organization of the dunce gene of Drosophila melanogaster has proved to be particularly complex, with two divergently transcribed genes, Sgs-4 and Pig-1, nested within its 79 kb intron (1). Here we report the identification and the molecular characterization of a third gene nested within the transcription unit of dunce. This newly identified gene is located nearly 6 kb downstream Pig-1, within a more upstream dunce intron. The gene is developmentally regulated and transcribed with the same polarity of dunce; several lines of evidence indicate that it might encode for a salivary gland secreted (Sgs) protein.

Nephrology nurses who are highly involved in the care of dialysis patients receiving Epoetin alfa are frequently responsible for educating and monitoring them as well. The following case study shows one methodology that can be used to accomplish these goals. The article highlights topics and terms for patient teaching, and an interdisciplinary care plan for monitoring Epoetin alfa treatments.

The aim of our study was to evaluate the efficacy of long-term migraine prophylaxis with flunarizine. The efficacy of the drug was evaluated on the basis of the frequency, pain severity and duration of migraine attacks. Frequency, the most modified parameter, was reduced to about half of the pre-treatment level in one to three months time. The condition remained more or less stable from the third treatment month onwards. The results showed remarkable efficacy of long-term prophylaxis with flunarizine, and the response was better in younger patients with a short history of migraine.

The effect of increased doses of Somatostatin-14 (3, 10, 30, 100, 300 micrograms/h) on basal release of insulin, pancreatic glucagon and pancreatic polypeptide (PP) was investigated on eight normal volunteers. Levels of Somatostatin-like immunoreactivity (SLI) was determined in order to correlate the increased SLI levels with the degree of islet hormone inhibition (r = 0.9947, p less than 0.01). By increasing the basal levels of SLI by one-third, a significant inhibition (p less than 0.01) of insulin, glucagon, and PP was noted (78.5, 78.6, 75.2%, respectively, on basal levels). The maximal effect was obtained with 300 micrograms/h for insulin, with 30 micrograms/h for glucagon and 100 micrograms/h for PP. In evaluating the relative inhibitory potency of somatostatin, expressed as ED50, the theoretic potency of somatostatin on each peptide had similar values, ranging from 30 to 10 micrograms/h. The present data show that a minimal peripheric increase in SLI is able to regulate basal islet pancreatic hormones.