Adenosine diphosphate sugar pyrophosphatase prevents glycogen biosynthesis in Escherichia coli

An adenosine diphosphate sugar pyrophosphatase (ASPPase, EC ) has been characterized by using Escherichia coli. This enzyme, whose activities in the cell are inversely correlated with the intracellular glycogen content and the glucose concentration in the culture medium, hydrolyzes ADP-glucose, the precursor molecule of glycogen biosynthesis. ASPPase was purified to apparent homogeneity (over 3,000-fold), and sequence analyses revealed that it is a member of the ubiquitously distributed group of nucleotide pyrophosphatases designated as "nudix" hydrolases. Insertional mutagenesis experiments leading to the inactivation of the ASPPase encoding gene, aspP, produced cells with marginally low enzymatic activities and higher glycogen content than wild-type bacteria. aspP was cloned into an expression vector and introduced into E. coli. Transformed cells were shown to contain a dramatically reduced amount of glycogen, as compared with the untransformed bacteria. No pleiotropic changes in the bacterial growth occurred in both the aspP-overexpressing and aspP-deficient strains. The overall results pinpoint the reaction catalyzed by ASPPase as a potential step of regulating glycogen biosynthesis in E. coli.     

Valor pronóstico del índice de riesgo nutricional para los candidatos a implante de un dispositivo de asistencia ventricular izquierda de flujo continuo

Introduction and objectivesMalnutrition has been shown to affect clinical outcomes in patients with heart failure. The aim of this study was to analyze the impact of preoperative nutritional status assessed by the nutritional risk index (NRI) on the prognosis of patients with a continuous-flow left ventricular assist device (cf-LVAD).MethodsWe performed a retrospective study of 279 patients who underwent cf-LVAD implantation between 2009 and 2015 in our center. Preoperative NRI was calculated and the patients were followed-up for 1 year. The association between preoperative NRI and postoperative clinical events was analyzed using multivariable logistic regression.ResultsThe prevalence of severe (NRI < 83.5), moderate (83.5 ≤ NRI < 97.5) and mild (97.5 ≤ NRI < 100) nutritional risk was 5.4%, 21.5%, and 9.3%. Mortality rates 1 year after cf-LVAD implantation in these 3 categories were 53.3%, 31.7%, 23.1% vs 18.0% (P < .001) in patients with a normal IRN. A normal preoperative NRI value was an independent predictor of lower risk of death from any cause during follow-up (aHR per 1 unit, 0.961; 95%CI, 0.941-0.981; P < .001) was and a predictor for a lower risk of postoperative infections (aOR, 0.968; 95%CI, 0.946-0.991; P = .007), respiratory failure (aOR, 0,961; 95%CI, 0.936-0.987; P = .004), and right heart failure (aOR, 0.963; 95%CI, 0.934-0.992; P = .014).ConclusionsMalnourished patients are at increased risk for postoperative complications and death after cf-LVAD implantation. Assessment of nutritional risk could improve patient selection and the early initiation of nutritional support.Full English text available from: www.revespcardiol.org/en     

Neutropenia, thrombocytopenia and hepatic injury associated with dexketoprofen trometamol therapy in a previously healthy 35-year-old woman

This case report describes a previously healthy 35-year-old woman, with an episode of fever, neutropenia, thrombocytopenia and elevation of biochemical markers of liver injury, 10 days after beginning drug therapy with dexketoprofen trometamol. Infectious and autoimmune causes of neutropenia, and viral or autoimmune hepatitis were excluded. The resolution following withdrawal of dexketoprofen trometamol confirms the possibility of an adverse drug reaction.     

Genetic evolution of the Spanish multidrug-resistant Salmonella enterica 4,5,12:i:- monophasic variant

We analyzed a collection of 60 Salmonella enterica 4,5,12:i:- phage type U302 multidrug-resistant monophasic variant strains, isolated in Spain between 2000 and 2007. Most strains showed resistance to ampicillin (A), chloramphenicol (C), sulfamethoxazole (Su), gentamicin (G), streptomycin (S), tetracycline (T), and co-trimoxazole (SxT) (an ACSuGSTSxT resistance pattern). Only one pulsed-field gel electrophoresis (PFGE) type was detected, with 19 subtypes (Simpson's index of diversity [SID]=0.89). Multiple-locus variable-number tandem-repeat analysis (MLVA) showed more variability, with 32 profiles (SID=0.97), but only showed diversity at the STTR5 and STTR6 loci. PCR and sequencing demonstrated all strains contained the same allantoin-glyoxylate pathway deletion. Four types of deletions were detected in the fljAB operon, all starting at the same position, at the STM2758 gene, and followed by an IS26 insertion. Furthermore, a representative set of strains of the four deletion types harbored plasmids with IS26. We propose that a Salmonella enterica serotype Typhimurium U302 multidrug-resistant (ACSuGSTSxT) strain, defective for the allantoin-glyoxylate pathway and containing IS26 at plasmid pU302L, could be the ancestor of the variant in Spain.     

Manual validation of FreeSurfer's automated hippocampal segmentation in normal aging,mild cognitive impairment,and Alzheimer Disease subjects

Hippocampal volume is reduced in Alzheimer Disease (AD) and has been proposed as a possible surrogate biomarker to aid early diagnosis. Whilst automated methods to segment the hippocampus from magnetic resonance images are available, manual segmentation, in spite of being time-consuming and unsuitable for large samples, is still the standard. In order to study the validity of FreeSurfer's automated method, we compared hippocampal automated measures with manual tracing in a sample composed of healthy elderly (N = 41), Mild Cognitive Impairment (MCI) (N = 23), and AD (N = 25) subjects. Percent volume overlap, percent volume difference, correlations, and Bland–Altman plots were studied. Automated measures were slightly larger than hand tracing ones (mean difference 10%). Percent volume overlap showed good results, but was far from perfect (78%). Manual and automated volume correlations were approximately 0.84 and the Bland–Altman analysis showed acceptable interchangeability of methods. Within-group analysis demonstrated that patient samples obtained smaller values in validity indexes than controls. Globally, FreeSurfer's automated hippocampal volumetry showed adequate validity when compared to manual tracing, with a tendency to overestimation. Nevertheless, the greater difference between automated and manual segmentation in atrophic brains suggests that studies in AD based on this software could be more likely to produce false negatives.     

Treatment of Renal Tumors by Percutaneous Ultrasound-Guided Radiofrequency Ablation Using a Multitined Electrode: Effectiveness and Complications

Background

Radiofrequency ablation (RFA) is a minimally aggressive, therapeutic alternative for renal tumors. It can be an alternative to nephrectomy in patients with previous nephrectomy, bilateral tumors, von Hippel-Lindau disease, or small renal carcinomas and in those with contraindications for surgery.

Objective

To assess the effectiveness of the treatment of renal tumors by RFA in the short and medium term and to identify the possible complications and the factors that determine therapeutic success.

Design, setting, and participants

A retrospective review of patients with renal tumors treated with RFA between May 2005 and December 2008 was performed in a tertiary academic hospital. Patients were selected among those with previous nephrectomy, bilateral neoplasms, von Hippel-Lindau disease, surgical risk, comorbidity, advanced age, or patient's refusal to surgery. Tumors with evidence of extrarenal extension were excluded. Patients were followed up for 10–50 mo using computed tomography and magnetic resonance imaging.

Intervention

Ultrasound-guided RFA was performed on 65 tumors (range: 1.2–5.3 cm) of 58 patients using multitined electrodes.

Measurements

Incomplete ablation rate, therapeutic success rate, and complications rate.

Results and limitations

Therapeutic success was achieved in 59 of 65 tumors (91%): 53 in a single session, 5 in two sessions, and 1 in three sessions. A significant relationship was observed between size and growth pattern of the tumor and both therapeutic success and incomplete ablation rates. Therapeutic success in tumors >5 cm was 60%. Complications were detected in 10 patients (13%); 5% were considered major complications.Limitations include the lack of pathologic studies to confirm a complete ablation and the lack of a control group to compare with the results of those who underwent nephrectomy.

Conclusions

RFA is safe and effective in renal tumors. Corticomedullary lesions and tumors >3 cm have greater possibility of incomplete ablation. In tumors >5 cm, RFA has a significant failure rate.     

Mandibular Metastasis of a Signet Ring Cell Carcinoma of the Breast in a Patient who Underwent Bilateral Mastectomy more than 25 Years Earlier

Summary

Background

Metastatic tumors account for less than 1% of all malignant tumors occurring in the oral cavity.

Case Report

The clinical case of a 94-year-old patient with a mandibular tumor is reported here. The patient had undergone bilateral mastectomy more than 25 years before. An immunohistochemical study found hormone receptors in signet ring cells, suggesting a diagnosis of breast cancer metastasis.

Conclusion

Immunohistochemical diagnosis and antineoplastic hormone therapy is the cornerstone in the management of this clinical case.Key Words: Mandible, Metastasis, Breast cancer, Signet ring cells