Enhancement of serotonergic and noradrenergic neurotransmission in the rat hippocampus by sustained administration of bupropion

Rationale  

Previous studies reported that bupropion, an effective antidepressant, exerts modulatory actions on serotonin (5-HT) and norepinephrine (NE) neurons.     

Identification of urinary metabolites of orally administered N,N-dimethyl-p-toluidine in male F344 rats

The metabolism of orally administered N,N-dimethyl-p-toluidine (DMPT) in male F344 rats was investigated. The rat urinary metabolite profile was determined by analytical reverse-phase high performance liquid chromatography (HPLC). Four radiolabeled peaks were observed, isolated, and purified by solid-phase extraction (SPE) and preparative HPLC methods. The 4 peaks were identified as p-(N-acetylhydroxyamino)hippuric acid (M1), DMPT N-oxide (M2), N-methyl-p-toluidine (M3), and parent DMPT. Metabolites M1 and M2 were identified by spectrometric and spectroscopic methods, including mass fragmentation pattern identification from both liquid chromatography/mass spectrometry and gas chromatography/mass spectrometry, and from chemical analysis of nuclear magnetic resonance spectra. Structural confirmation of metabolite M2 was accomplished by comparison with a synthetic standard. Peaks M3 and the peak suspected to be DMPT were identified by comparison of their HPLC retention times and mass fragmentation patterns with authentic standards of N-methyl-p-toluidine and DMPT, respectively. DMPT metabolism is similar to that reported for N,N-dimethylaniline.     

Huge immature teratoma of the liver in an adult: a case report and review of the literature

Teratoma tumors are tumors of childhood and, to the best of our knowledge, only 9 cases of hepatic teratoma and 1 case of immature teratoma of the liver had been reported in adults in the English literature. We present the second case of immature liver teratoma in a 22-year-old woman who presented with a 4-month history of abdominal pain and fullness sensation. A computed tomography (CT) scan of the abdomen and pelvis showed a huge well-defined heterogeneous mass in the right lobe of the liver containing fat, calcification, and cystic and solid parts, all suggestive of a teratoma. A right hepatectomy and an omentectomy were performed. The pathology report showed a 27 cm mass composed of ectodermal, mesodermal and endodermal components with minimal atypia and foci of immature components suggestive of immature teratoma, which is the largest liver teratoma to be reported. The patient was discharged in good health. During 8 months of follow-up, a CT scan and α-fetoprotein levels were both normal, and the patient is still alive.     

Absence of a role for interleukin‐13 in inflammatory bowel disease

IL‐13 has been implicated in the pathogenesis of ulcerative colitis (UC), and may have a role in animal models of gut fibrosis. We studied the involvement of IL‐13 in inflammation and fibrosis in UC and Crohn's disease (CD). Intestinal biopsies and anti‐CD3/CD28‐ or anti‐CD2/CD28‐stimulated lamina propria mononuclear cells from UC and CD patients and control subjects were cultured, and IL‐13, IL‐4, IL‐5, IL‐17A and IFN‐γ production was measured. Mucosal IL‐13‐producing cells were characterised by flow cytometry. Gut explants from strictured CD, non‐strictured CD and healthy donors were cultured ex vivo, and secreted IL‐13, IL‐1β and collagen were measured. IL‐13 production by mucosal explants and activated lamina propria mononuclear cells did not differ between CD, UC and control subjects, and was at least a log lower than IFN‐γ and IL‐17A. IL‐13‐producing cells, and in particular natural killer T cells, were uniformly low in all groups. IL‐4 and IL‐5 were undetectable in culture supernatants. Explants of CD strictures produced low amounts of IL‐13, whereas IL‐1β and collagen were elevated. We could not confirm that UC or strictured CD are associated with elevated IL‐13 production. These data suggest that an anti‐IL‐13 Ab would not be an appropriate therapeutic strategy in inflammatory bowel disease.     

Tissue-Engineered Heart Valve: Future of Cardiac Surgery

Background

Heart valve disease is currently a growing problem, and demand for heart valve replacement is predicted to increase significantly in the future. Existing “gold standard” mechanical and biological prosthesis offers survival at a cost of significantly increased risks of complications. Mechanical valves may cause hemorrhage and thromboembolism, whereas biologic valves are prone to fibrosis, calcification, degeneration, and immunogenic complications.

Methods

A literature search was performed to identify all relevant studies relating to tissue-engineered heart valve in life sciences using the PubMed and ISI Web of Knowledge databases.

Discussion

Tissue engineering is a new, emerging alternative, which is reviewed in this paper. To produce a fully functional heart valve using tissue engineering, an appropriate scaffold needs to be seeded using carefully selected cells and proliferated under conditions that resemble the environment of a natural human heart valve. Bioscaffold, synthetic materials, and preseeded composites are three common approaches of scaffold formation. All available evidence suggests that synthetic scaffolds are the most suitable material for valve scaffold formation. Different cell sources of stem cells were used with variable results. Mesenchymal stem cells, fibroblasts, myofibroblasts, and umbilical blood stem cells are used in vitro tissue engineering of heart valve. Alternatively scaffold may be implanted and then autoseeded in vivo by circulating endothelial progenitor cells or primitive circulating cells from patient’s blood. For that purpose, synthetic heart valves were developed.

Conclusions

Tissue engineering is currently the only technology in the field with the potential for the creation of tissues analogous to a native human heart valve, with longer sustainability, and fever side effects. Although there is still a long way to go, tissue-engineered heart valves have the capability to revolutionize cardiac surgery of the future.