Hospital outbreak caused by a carbapenem-resistant strain of Acinetobacter baumannii: patient prognosis and risk-factors for colonisation and infection

Between October 2001 and August 2002, 30 hospital patients became infected or colonised by a multiresistant (including to carbapenems) epidemic strain of Acinetobacter baumannii (AbMR) in a hospital outbreak. This study analysed the risk-factors associated with acquisition of this epidemic strain and investigated the prognosis of patients infected by AbMR, with the aim of elucidating factors which lead to mortality. A case-control study of the acquisition of AbMR in patients infected or colonised in the hospital outbreak was performed. Independent risk-factors leading to death were studied by logistic regression analysis. Multivariate analysis of the risk-factors for colonisation/infection with AbMR revealed an independent association with the presence of an arterial catheter (OR, 1.13; 95% CI, 1.03-1.25) and administration of imipenem as monotherapy (OR, 11.12; 95% CI, 2.33-53.09). Multivariate analysis of the prognostic features leading to mortality revealed a significant association with hypotension or shock (OR, 24.63; 95% CI, 1.56-387.56) at the time of bacterial isolation.     

How reproducible is cutaneous electrogastrography? An in-depth evidence-based study1

AIM: To check on reproducibility of parameters of the cutaneous electrogastrogram registered at a close or a distant time span. METHODS: Twenty-two volunteers recruited by an advertisement (11 females and 11 males, median age 25 years, range: 18-35) underwent three surface electrogastrography examinations of which two were taken on consecutive days and the third one was accomplished at least 2 weeks before or after the two other sessions. The examination involved a 30-min fasted recording, followed by a 90-min postprandial registration after intake of a 394-kcal mixed solid-liquid test meal. RESULTS: Parameters of the electrogastrogram pertaining to the frequency of the gastric slow waves exhibited good to moderate reproducibility, whereas fair reproducibility characterized parameters expected to describe the power of gastric slow waves. With the exception of the difference fed minus fasted power (DeltaDP), in no instance was the medium term reproducibility any worse than the short term one. Categorical data analysis revealed that the relative time share of normogastria postprandially exhibited a better reproducibility than in the fasted period. The Cohen's kappa-value of 0.459 for the DeltaDP for the medium term reproducibility placed this parameter within the range of moderate agreement between repeat examinations. Of the two two-parameter combinations considered, the alliance of the fasted and fed normogastria performed worse than any of those parameters considered alone, whereas a combination of the DeltaDP with the fed-state normogastria revealed a kappa-value amounting to 0.510 for the medium term reproducibility. CONCLUSIONS: The feasibility of some electrogastrographic parameters to convey clinically useful information may be hampered by their fair reproducibility. Recoding of parameters of the cutaneous electrogastrogram from primary continuous to secondary categorical may help achieve a better agreement between repeat examinations.     

Molecular biology in prostate cancer

Summary Genes involved in cancer generation are usually tumor suppressors and oncogenes. Progressive genetic alterations in these genes are involved in the mechanisms of tumorigenesis. In prostate cancer, additionally several chromosomal loci that should harbor mutated genes have been proposed. Some genes have been found altered in prostate cancer, such as PTEN, TP53, AR, RNASEL (HPC1), ELAC2 (HPC2), CDKN2A and MSR1 and those can be natural targets for new strategies of treatment. Besides, gene therapy has been suggested to be suitable for prostate cancer treatment. This approach includesex vivo corrective therapy, suicide, and antisense therapy.     

Recombinant human alpha lymphotoxin (tumor necrosis factor-beta) induces peripheral neutrophilia and lymphopenia in the rat.

Recombinant human alpha lymphotoxin (rLT) administered intravenously to Lewis rats induces peripheral neutrophilia and lymphopenia in a dose-response dependent fashion. A dose of 30,000 units of rLT induced a neutrophilia (1589 +/- 326 to 5554 +/- 1050 neutrophils/cu mm) and lymphopenia (10,368 +/- 992 to 4636 +/- 878 lymphocytes/cu mm) at 2 hours after injection that was highly significant (P less than 0.001 and P less than 0.001, respectively) in comparison with vehicle controls. The kinetics of the neutrophilia that peaked at 2 hours as well as of the lymphopenia were highly reminiscent of the neutrophilia and lymphopenia following intravenous administration of either recombinant human interleukin-1 (IL-1) alpha or beta to rats. The peripheral neutrophilia was accompanied by a significant depletion of bone marrow neutrophils (P less than 0.001), as is also known to occur after administration of IL-1. Systemic blood pressure was not affected by rLT, which suggested that the changes in circulating leukocyte subsets were not attributable to hemodynamic changes nor to the hemodynamic-change-related release of adrenal hormones. Adrenalectomy did not alter the rLT-induced neutrophilia or lymphopenia, which suggested that rLT does not mediate its hematologic effects on peripheral blood leukocytes via the release of adrenal hormones. Pretreatment of rats with dexamethasone, indomethacin, or aspirin also did not alter rLT-induced neutrophilia or lymphopenia, which suggested that rLT-induced hematologic effects were not mediated via arachidonic acid metabolites, in stark contrast to IL-1 induced neutrophilia, which is inhibited by both dexamethasone and indomethacin.     

Distension-induced gastric accommodation in functional dyspepsia: effect of autonomic manipulation

Functional dyspepsia (FD) is associated with impaired gastric accommodation and autonomic dysregulation. The aim of this study was to investigate the effects of autonomic manipulation on distension-induced gastric accommodation in subjects with and without FD, using a newly developed gastric barostat paradigm. Twelve healthy subjects (HS) and 18 subjects with FD had four barostat examinations each: no intervention, intravenous atropine (1 mg), vagal stimulation (mental relaxation with deep breathing) and acute stress stimulation (serial subtraction task). Intrabag pressure increased from 1 to 15 mmHg in 5 min (ramp phase), and was maintained at 15 mmHg for 5 min (tonic phase). Volume responses were analysed using predefined parameters. There were no significant group differences in accommodation variables between HS and subjects with FD. The FD group could be subdivided into two distinct subgroups: subgroup 1 (n = 7, 38%) with low maximum volume and accommodation rate, and subgroup 2 with normal accommodation (n = 11). In subgroup 1, but not in subgroup 2 atropine increased maximum volume and accommodation rate substantially. Neither mental stress nor mental relaxation changed any of the accommodation variables. In a subgroup of subjects with FD, impairment of distension-induced gastric accommodation can be improved by cholinergic blockade, but not by acute physiological autonomic manipulation.     

Impaired modulation of motor cortex excitability by homonymous and heteronymous muscle afferents in focal hand dystonia.

A decrease of heteronymous median nerve-evoked inhibition of corticospinal projections to forearm extensor muscles was reported in a group of 10 dystonic patients by Bertolasi and colleagues in 2003. Here we tested the excitability of corticomotoneuronal connections to both wrist extensor (ECR) and flexor (FCR) muscles after conditioning stimulation of median and also radial nerve at rest in a group of 25 patients with focal hand dystonia compared to 20 healthy subjects. We also investigated the effect of the wrist dystonic posture, either in flexion or in extension, on the afferent modulation of ECR and FCR motor evolved potentials (MEPs). The heteronymous (median-induced) but also homonymous (radial-induced) inhibitions (interstimuli intervals 13-21 ms) of ECR MEP size observed in healthy subjects were decreased in patients. In addition, homonymous (median-induced) facilitation of FCR MEP size was also decreased in patients while heteronymous inhibition (radial-induced) was not. Neither the involvement of the target muscle in the dystonic posture nor the origin of the afferent volley (from a dystonic muscle) influenced the degree of impairment of afferent modulation of the MEP. These findings support the view that a global abnormal somatosensory coupling in focal hand dystonia may contribute to an inadequate motor command to wrist muscles.     

Scintigraphic validation of AC Biosusceptometry to study the gastric motor activity and the intragastric distribution of food in humans

Abnormal intragastric distribution of food (IDF) and a phasic contractility in the proximal stomach have been related to dyspeptic symptoms. Thus, the behaviour of the stomach and the proximal region, in particular, continues to attract attention and demand for reliable and comfortable techniques. The aims of this study were to employ AC Biosusceptometry (ACB) and scintigraphy to evaluate IDF and gastric motor activity in humans. Fifteen healthy volunteers ingested 60 mL of yogurt containing 2 mCi of 99mTc and 4 g of ferrite. Each volunteer had gastric motility and IDF evaluated twice on separate days; on one occasion by ACB and another by scintigraphy. Digital signal processing was performed in MatLab (Mathworks Inc., Natick, MA, USA). Results were expressed as mean +/- SD. Similar results of distal accumulation time (P < 0.001) were obtained for scintigraphy (6.93 +/- 3.25 min) and for ACB (7.04 +/- 3.65 min). Fast Fourier Transform revealed two dominant frequencies (P > 0.9). Besides the well-know frequency of 3 cpm, our results showed identical frequencies in proximal stomach recordings (P < 0.001) for scintigraphic (1.01 +/- 0.01 cpm) and ACB (0.98 +/- 0.06 cpm). In summary, our data showed that scintigraphy and ACB are promising techniques to evaluate several aspects of gastric motility. Moreover, ACB is non-invasive, radiation-free and deserves the same importance as conventional methods for this kind of analysis.     

Grafts of porcine intestinal submucosa for repair of cervical and abdominal esophageal defects in the rat.

Porcine small intestinal submucosa (SIS) is a cell-free collagen matrix that has demonstrated its ability as scaffold material for constructive remodeling of damaged or missing tissue. The purpose of this study was to evaluate the morphology and function of esophagoplasty in rat using a porcine SIS scaffold for the repair of a semi-circumferential defect in the cervical or in the abdominal esophagus. Sixty-seven rats underwent surgical excision of the anterior wall either of the cervical or of the abdominal esophagus and subsequent repair of the defect with an SIS patch graft. Outcomes of weight gain, signs of dysphagia, hematological and serum chemistry parameters, and barium swallow studies were used to assess the progress of healing and function over a 150-day time period. The grafts were studied for gross changes and histology at predetermined time points. Ninety-four percent of the SIS-treated rats survived, showing no significant differences in survival rate between groups. The grafted animals did well, without signs of dysphagia, and gaining weight. Barium swallow studies showed no evidence of fistula, significant stenosis, or diverticula. No hematological or serum biochemistry abnormalities were found. By 150 days, the SIS graft was replaced with esophageal-derived tissues. Specimens were completely lined by keratinized stratified squamous epithelium and showed complete regeneration of muscle fibers and scarce immunoreactivity for nerve. In the rat model, a patch graft technique using porcine SIS appears to induce esophageal regrowth either in cervical and abdominal esophagus. The repair mechanism occurred through a regenerative healing process.