Teaching infection control: a theoretical and practical essay

This article contains reflections concerning infection prevention and control measures starting from the adherence of health professionals to prevention measures. It points out worrisome environment-related aspects stemming from the use of disposable materials in spite of the benefits that they represent in terms of safety and reduction of operational costs, among others. All these issues are presented as a challenge to infection control teaching in the education of health professionals. Some guiding presuppositions are also presented.     

First report and toxicological assessment of the cyanobacterium Cylindrospermopsis raciborskii from Portuguese freshwaters

The freshwater cyanobacterium Cylindrospermopsis raciborskii has become increasingly prevalent in freshwaters worldwide. This species is a concern from a water quality perspective due to its known ability to produce a potent hepatotoxic alkaloid cylindrospermopsin, which has been implicated in outbreaks of human sickness and cattle mortality. C. raciborskii strains isolated from Brazil have also been found to produce the highly toxic paralytic shellfish poisons (PSPs). This article reports the toxicity of four strains of C. raciborskii taken from three reservoirs and one river in Portugal, as well as the occurrence of this species in other water bodies used for potable and recreational purposes. All four strains grown in pure culture in the laboratory were found to be toxic in the mouse bioassay at 8-24h after intraperitoneal administration of single doses ranging from 1337 to 1572 mgkg(-1) Histological examination indicated that liver damage was the primary lesion; in addition, there was inflammation in the intestine. HPLC/MS tests for the presence of cylindrospermopsin, microcystins, and PSP toxins were negative. The available evidence suggests that another toxin may be present. This constitutes the first report of toxic C. raciborskii in Europe and draws attention to the need for increased monitoring of this cyanobacterium in water bodies used for potable and recreational purposes.     

Mediterranean diet,but not red wine,is associated with beneficial changes in primary haemostasis

OBJECTIVE: (1) To compare the effect of an alcohol-free Mediterranean-type diet (MD) and a high-fat diet (HFD) on variables of primary haemostasis (bleeding time, plasma von Willebrand factor and platelet aggregation/secretion). (2) To test whether red wine supplementation modified these variables, independently of the diet. DESIGN, SUBJECTS AND INTERVENTION: Controlled prospective intervention study. Two groups, each consisting of 21 healthy male university students (22+/-3.4 y), received either MD or HFD during 90 days. Between days 30 and 60, both diets were supplemented with 240 ml/day of red wine. Baseline (T0) and T30, T60 and T90-day samples were drawn. Bleeding time was measured before (day 30) and after (day 60) wine supplementation. No drop out from the study was experienced. SETTING: University campus and outpatient nutrition clinic. RESULTS: All baseline (day 0) variables did not differ significantly between study groups. On day 30, individuals on MD had significantly higher levels of plasma beta-carotene, folate, ascorbate, and eicosapentaenoic acid in plasma lipid fractions, than those on HFD. Total plasma cholesterol, HDL and LDL did not change significantly in either study group at any time point. After 30 days on each diet, individuals on MD had longer bleeding time (BT) than those on HFD (7.6+/-2.8 vs 5.8+/-1.7 min; P=0.017). BT did not change significantly after I month of wine supplementation (7.1+/-2.0 vs 5.5+/-2.0 min, respectively). Plasma von Willebrand factor (vWF : Ag) on day 0 was 89+/-40 and 111+/-70% in MD and HFD groups, respectively (P=0.21). These values did not change significantly at 30, 60 or 90 days. MD intake was associated with an increase in platelet serotonin secretion (P=0.02) and a marginal increase in platelet aggregation after stimulation with epinephrine (P=0.07). Wine intake resulted in a marginal decrease in platelet (14)C-5-HT secretion with 4 micro M ADP (P=0.07). However, both platelet aggregation and secretion were consistently increased when using collagen as agonist (1 and 2 micro g/ml, P=0.01). CONCLUSION: The longer BT in individuals on MD, obtained independently of red wine, denotes less interaction of platelets with the vascular wall, which could be beneficial from the point of view of cardiovascular (CV) risk. This effect is not explained by changes in the measured haemostatic determinants of BT (plasma vWF, ex vivo platelet function), and might be attributed to other as yet unknown vascular factors. Moderate consumption of red wine results in a significant increase in ex vivo platelet aggregation and secretion after stimulation with collagen. This observation contradicts previous reports, although further studies are required to elucidate the influence of this finding on CV risk.     

Risk factors for failure of Helicobacter pylori therapy--results of an individual data analysis of 2751 patients

AIM: To study risk factors for failure of Helicobacter pylori eradication treatment. METHODS: Individual data from 2751 patients included in 11 multicentre clinical trials carried out in France and using a triple therapy, were gathered in a unique database. The 27 treatment regimens were regrouped into four categories. RESULTS: The global failure rate was 25.8% [95% CI: 24-27]. There was a difference in failure rate between duodenal ulcer patients and non-ulcer dyspeptic patients, 21.9% and 33.7%, respectively (P < 10(-6)). In a random-effect model, the risk factors identified for eradication failure in duodenal ulcer patients (n = 1400) were: to be a smoker, and to have received the group 4 treatment, while to receive a 10 day treatment vs. 7 days protected from failure. In non-ulcer dyspeptic patients (n = 913), the group 2 treatment was associated with failure. In both groups, age over 60 was associated with successful H. pylori eradication. There were less strains resistant to clarithromycin in duodenal ulcer patients than in non-ulcer dyspeptic patients. Clarithromycin resistance predicted failure almost perfectly. CONCLUSION: Duodenal ulcer and non-ulcer dyspeptic patients should be managed differently in medical practice and considered independently in eradication trials.     

Microscopic changes at the neuromuscular junction in free muscle transfer

Free muscle transfers do not generate the same force after transfer as that at the original sites. Light and electron microscopy were used to study serially during 30 weeks the changes at the neuromuscular junction after free muscle transfer of the gracilis muscle in the adult Wistar rat. Under light microscopy, after staining with acetylthiocholine the neuromuscular junction showed changes of degeneration with withdrawal of the innervating axon terminal followed by regeneration and reconstitution of the neuromuscular junction. The newly formed neuromuscular junction still lacked the structural detail seen in the control neuromuscular junction, even after 30 weeks. With the electron microscope, mitochondrial swelling and clumping of the synaptic vesicles were followed by withdrawal of the axon terminal from the muscle membrane on denervation. The infolding of the muscle membrane at the neuromuscular junction became less prominent. With reinnervation the ultrastructure of the junction was only partially reestablished with poorly reconstituted primary and secondary folds of the muscle membrane 30 weeks after the transfer. Failure of complete reformation of the ultrastructure of the neuromuscular junction may provide another explanation for failure of full recovery of skeletal muscle function after free muscle transfer.     

Prevalence of long-term upper aerodigestive symptoms after uncomplicated bilateral thyroidectomy

BACKGROUND: Subjective nonspecific upper aerodigestive symptoms (UADS) are not uncommon after thyroidectomy. Their type, duration, and prevalence, however, have not been investigated in a controlled design. The objective of this study was to investigate the prevalence of UADS after thyroidectomy. METHODS: A consecutive cohort of 60 patients who had undergone uncomplicated total (n = 38) or near total (n = 22) thyroidectomy were investigated retrospectively at a mean of 4 years after surgery. An independent unblinded researcher interviewed each patient and asked for the presence or frequency of voice changes, cough, dysphagia, neck strangling, and annual incidence of common colds, before and after thyroidectomy. Sixty patients, matched for age, sex, and smoking habits, who had undergone laparoscopic cholecystectomy during the same years served as control subjects. RESULTS: The prevalence of UADS was similar before thyroidectomy (13%) and cholecystectomy (15%). After operation, UADS had a higher prevalence among thyroidectomized patients: nonspecific voice changes (28% vs 3%), neck strangling (22% vs 0%), and impaired swallowing (15% vs 3%) (P < or = .02 in each). Neck strangling was associated with voice changes and dysphagia (P < or = .03 each). CONCLUSIONS: Subjective UADS are common long after thyroidectomy. These symptoms may be related to injury to the extrinsic perithyroidal neural plexus innervating the pharyngeal and laryngeal structures.     

Antioxidant flavan-3-ols and flavonol glycosides from Maytenus aquifolium

TLC autographic assay revealed, in the EtOAc extract obtained from leaves and root bark of Maytenus aquifolium (Celastraceae), the presence of fi ve compounds exhibiting antioxidant properties towards beta-carotene. They were isolated and identified as epigallocatechin (1), (+) ouratea-catechin (2), proanthocyanidin (3), kaempferol 3-O-alpha-L-rhamnopyranosyl (1-->6)-O-[beta-D-glucopyranosyl (1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl (4) and quercetin 3-O-alpha-L-rhamnopyranosyl (1-->6)-O-[beta-D-glucopyranosyl (1-->3)-O-alpha-L-rhamnopyranosyl-(1-->2)]-O-beta-D-glucopyranosyl (5). The isolates were investigated for their redox properties using cyclic voltammetry and for their radical scavenging abilities through spectrophotometric assay on the reduction of 2,2-diphenyl-pycryl hydrazyl (DPPH). These results were correlated to the inhibition of beta-carotene bleaching on TLC autographic assay and to structural features of the flavonoids.     

Comparison of sustained-release morphine with sustained-release oxycodone in advanced cancer patients

The antinociceptive effect of morphine and oxycodone is mediated preferentially at micro and kappa receptors, respectively. The aim of this study was to evaluate the analgesic profile of the combination of morphine and oxycodone in cancer pain, compared to the standard administration of morphine alone. Controlled-release formulations of oxycodone (CRO) and morphine (CRM) were compared in 26 patients. The study started with an open-label, randomised titration phase to achieve stable pain control for 7 days, followed by a double-blind, randomised crossover phase in two periods, 14 days each. At any point, patients were allowed to use oral immediate-release morphine (IRM) as needed, in order to keep visual analogue scale < or =4. Pain, satisfaction, adverse effects and number of daily rescue morphine tablets were assessed. A total of 22 patients were evaluated. The weekly upload consumption ratio in morphine/oxycodone was 1 : 1.8 (1.80, 1.83, 1.76, 1.84). The weekly IRM consumption was higher in patients having CRM compared to patients having CRO (ratio morphine/oxycodone: 1.6, 1.6, 1.6, 1.7) (P<0.05). Patients receiving oxycodone complained of less nausea and vomiting. The rescue morphine analgesic consumption was 38% higher in patients receiving only morphine, compared to patients receiving both morphine and oxycodone. The results suggest that the combination of morphine/oxycodone (opioids with differential preferential sites of action) can be a useful alternative to morphine alone, resulting in a better analgesia profile and less emesis.