Synthesis and in vitro evaluation of antifungal and cytotoxic activities of eugenol glycosides

Six eugenol glycosides were prepared in order to assess their antifungal activity against Candida species. They were synthesized by glycosylation of eugenol with the appropriate glycosyl bromides followed by deacetylation with sodium methoxide in methanol and were evaluated in vitro for their antifungal activity through a Mueller–Hinton broth microdilution method. The peracetyl glycoside (derivative 4) was the most promising one since it was able to inhibit growth of C. albicans, C. tropicalis and C. glabrata with IC₅₀ values much lower than that of the prototype eugenol. Derivative 4 showed to be 160.0 and 3.4 times more potent than eugenol and fluconazole, respectively, against C. glabrata with low cytotoxity (selectivity index of 45). Moreover, it was possible to verify the positive effect of gluco configuration and lipophilicity on antifungal activity, since glucose peracetyl derivatives were more active than the free sugars of galacto configuration.     

The activity and expression of NTPDase is altered in lymphocytes of multiple sclerosis patients

BackgroundMultiple sclerosis (MS) is a demyelinating neurological disease, which is presumed to be a consequence of infiltrating lymphocytes that are autoreactive to myelin proteins. ATP and adenosine contribute to fine-tuning immune responses and NTPDase (CD39) and adenosine deaminase (ADA) are important enzymes in the control of the extracellular levels of these molecules at the site of inflammation. We evaluated the activity and expression of NTPDase and adenosine deaminase (ADA) activity in lymphocytes from patients with the relapsing–remitting form of MS (RRMS).MethodsThis study involved 22 patients with RRMS and 22 healthy subjects as a control group. The lymphocytes were isolated from blood and separated on Ficoll density gradients and after isolation the NTPDase and ADA activities were determined.ResultsThe NTPDase activity and expression were increased in lymphocytes from RRMS patients when compared with the control group (p < 0.05). In addition, a decrease in ADA activity was observed in lymphocytes from these patients when compared to the control group (p < 0.05).ConclusionsThe regulation of ATP and adenosine levels by NTPDase and ADA activities may be important to preserve cellular integrity and to modulate the immune response in MS.     

Ontogeny of soluble and particulate prolyl endopeptidase activity in several areas of the rat brain and in the pituitary gland

We have analyzed the activity of prolyl endopeptidase (PEP) in several areas of the rat brain (brain cortex, striatum, brain stem, cerebellum and hypothalamus) and in the pituitary gland during ontogeny. In all of these areas, we observed a reduction in PEP activity during development. However, the temporal profile of these alterations was found to be area specific and differences in the ontogeny of the soluble and particulate forms of PEP were observed. Thus, by postnatal day 20 (PD20), soluble PEP activity had began to decrease in the brain cortex and striatum, whereas decreased soluble PEP activity was observed earlier, at PD15, in the brain stem and cerebellum. Changes in the particulate fraction were even more pronounced. Senescence was associated with decreased soluble PEP activity in the striatum, but in contrast, particulate PEP activity was found to be increased in the senescent brain stem. The present results indicate that alterations in the levels of activity of PEP may represent an important event in the development and aging of the central nervous system.     

Gastrointestinal stromal tumor (GIST) mistaken for pancreatic pseudocyst – case report and literature review

A 74‐year‐old female patient underwent a Roux‐en‐Y cystjejunostomy for pancreatic pseudocyst developed several melena episodes and she was surgically reappraised. The main diagnostic concern was a pancreatic cystic neoplasm. A 12 × 8.0 × 5.0 cm retro‐gastric lesion was resected and pathology report indicated an unsuspected gastrointestinal stromal tumor (GIST). The report aimed to describe an atypical presentation of GIST.     

Liver failure caused by herpes simplex virus thymidine kinase plus ganciclovir therapy is associated with mitochondrial dysfunction and mitochondrial DNA depletion

Herpes simplex virus thymidine kinase (HSV-tk) converts ganciclovir (GCV) into an active compound, which can be incorporated into DNA molecules and terminate DNA synthesis. Gene transfer of HSV-tk followed by GCV administration has been used with success to treat experimental cancer and this strategy has entered into clinical trials. Although it is thought that the cytotoxic effect occurs mainly in tumoral dividing cells, where mitotic activity favors integration of the genotoxic compound into nuclear DNA, there are concerns of potential damage to normal nondividing cells. In the present work we have explored the mechanisms of HSV-tk/GCV toxicity and in particular whether this therapy may cause lesions of mitochondrial DNA (mtDNA) and mitochondrial dysfunction. We found that the administration of GCV to rats injected with adenovirus encoding HSV-tk induced hepatocellular damage characterized by the presence of apoptotic bodies, ballooning of hepatocytes, and severe hepatic steatosis with mitochondria enlargement and cristae dissolution at the ultrastructural level. Remarkably, Southern blot analysis showed substantial reduction in the amount of mtDNA in the liver. Using radiolabeled GCV we could demonstrate incorporation of this compound into both nuclear and mtDNA in HSV-tk-transduced rat hepatocytic cell line MCA-RH7777 and subsequent alteration of mitochondrial function. Our observations confirm that GCV can damage both nuclear and mtDNA in cells transduced with HSV-tk and that this effect could be responsible for severe mitochondrial dysfunction and toxicity in normal nondividing cells. These data are relevant for the design of clinical trials using adenoviral vectors encoding HSV-tk.     

Statistical shape modelling for the analysis of head shape variations

The aim of this study is, firstly, to create a population-based 3D head shape model for the 0 to 2-year-old subjects to describe head shape variability within a normal population and, secondly, to test a combined normal and sagittal craniosynostosis (SAG) population model, able to provide surgical outcome assessment.3D head shapes of patients affected by non-cranial related pathologies and of SAG patients (pre- and post-op) were extracted either from head CTs or 3D stereophotography scans, and processed. Statistical shape modelling (SSM) was used to describe shape variability using two models – a normal population model (MODEL1) and a combined normal and SAG population model (MODEL2). Head shape variability was described via principal components analysis (PCA) which calculates shape modes describing specific shape features.MODEL1 (n = 65) mode 1 showed statistical correlation (p < 0.001) with width (125.8 ± 13.6 mm), length (151.3 ± 17.4 mm) and height (112.5 ± 11.1 mm) whilst mode 2 showed correlation with cranial index (83.5 mm ± 6.3 mm, p < 0.001). The remaining 9 modes showed more subtle head shape variability. MODEL2 (n = 159) revealed that post-operative head shape still did not achieve full shape normalization with either spring cranioplasty or total calvarial remodelling.This study proves that SSM has the potential to describe detailed anatomical variations in a paediatric population.     

Inhibition of 5‐lipoxygenase attenuates inflammation and bone resorption in lipopolysaccharide‐induced periodontal disease

1 Background

Arachidonate‐5‐lipoxygenase (5‐LO) activity and increased leukotriene B4 (LTB4) production have been implicated in various inflammatory conditions. Increased production of leukotrienes has been associated with periodontal diseases; however, their relative contribution to tissue destruction is unknown. In this study, an orally active specific 5‐LO inhibitor is used to assess its role in inflammation and bone resorption in a murine model of lipopolysaccharide (LPS)‐induced periodontal disease.

2 Methods

Periodontal disease was induced in Balb/c mice by direct injections of LPS into the palatal gingival tissues adjacent to the maxillary first molars three times per week for 4 weeks. Animals were treated with biochemical inhibitor (2 mg/kg/daily) or the same volume of the vehicle by oral gavage. Microcomputed tomography analysis was used to assess bone resorption. Enzyme immunoassay determined LTB4, and enzyme‐linked immunosorbent assays quantified tumor necrosis factor (TNF), interleukin (IL)‐12, and IL‐10 in gingival tissues. Histologic sections were used for the morphometric analysis (number of neutrophils and mononuclear cells). Osteoclasts were counted in tartrate‐resistant acid phosphatase–stained sections.

3 Results

Administration of 5‐LO inhibitor effectively reduced production of LTB4 (23.7% decrease) and significantly reduced TNF and IL‐12 levels in gingival tissues. Moreover, reduction of LTB4 levels in gingival tissues was associated with a significant decrease in bone resorption and a marked reduction in number of osteoclasts and inflammatory cells.

4 Conclusion

5‐LO activity plays a relevant role in inflammation and bone resorption associated with the LPS model of experimental periodontal disease.     

Effect of repeated radiofrequency catheter ablation on left atrial function for the treatment of atrial fibrillation

Radiofrequency catheter ablation (RFCA) is a potential curative treatment for atrial fibrillation (AF) by eliminating the arrhythmia and inducing left atrial (LA) reverse remodeling. However, the effect on LA function, especially after repeated procedures, has scarcely been studied. The aim of this study was to evaluate the impact of RFCA on LA size and function in patients with AF after a first and a repeated procedure. RFCA was performed in 154 patients with symptomatic drug-refractory AF. LA volumes and function were assessed with real-time 3-dimensional echocardiography before and 6 months after the procedure. Recurrence of the arrhythmia was defined as any atrial tachyarrhythmia lasting >30 seconds, clinically documented or by 24-hour Holter recording, after the first 6 months after ablation. Of the 154 patients, 104 (67%) required only a first ablation, and 50 (33%) required redo RFCA. LA volume was reduced after first RFCA (from 60 ± 19 to 52 ± 17 ml for 3-dimensional LA maximum volume, p <0.001, and from 38 ± 18 to 33 ± 15 ml for 3-dimensional LA minimum volume, p <0.000) without impairment of LA contractile function, measured as the active emptying percentage of total volume (39 ± 25% vs 43 ± 26%, p = NS). After repeated RFCA procedures, 3-dimensional LA maximum volume was reduced (from 57 ± 18 to 52 ± 18 ml, p = 0.04), also without further LA contractile function impairment (active emptying percentage of total volume) (36 ± 24% vs 36 ± 25% of total volume, p = NS). This effect was similar in paroxysmal and persistent AF. In conclusion, RFCA induces reductions in LA volumes without a deleterious impact on contractile function, even after repeated ablation.