[The laryngeal tube]

The laryngeal tube (VBM Medizintechnic GmbH, Sulz, Germany) is a supraglottic device designed for airway management in spontaneous or positive-pressure ventilation during anesthesia or in cardiopulmonary resuscitation. Currently, the tube is available in 4 versions: the standard laryngeal tube, the disposable tube (LT-D), the dual-lumen tube (with a tube for suction) (LTS II), and the disposable LTS (LTS-D). The design of the tube has been modified several times. It is easy to insert and the airway seal is more effective than that of the laryngeal mask. The incidence of complications is similar for both devices, though use of the laryngeal tube requires more adjustments. The standard tube is somewhat less effective than the ProSeal laryngeal mask, though the new LTS II has been improved considerably. The laryngeal tube is effective as an aid to management of the difficult airway. We reviewed the literature indexed on MEDLINE through December 2006 using the search terms laryngeal tube, anesthesia, equipment, and airway.

Infants attend to second-order relational properties of faces

Two experiments investigated whether 7-month-old infants attend to the spatial distance measurements relating internal features of the human face. A visual preference paradigm was used, in which two versions of the same female face (one either lengthened or shortened, and one nonmodified) were presented simultaneously. In Experiment 1, infants looked longer at the nonmodified faces, which were determined to match the average distance relationships found in a sample of faces drawn from the same population. Longer looking times for modified faces were found in Experiment 2, in which the nonmodified faces were unusually long and the modified faces conformed to average distance measurements. It is proposed that infants' attention to the spatial relations of internal face features is an optimal tool for lifelong face recognition.

[Multicenter study on the usefulness of the NasOral system for the denitrogenation and apneic oxygenation in anesthesia]

OBJECTIVES

To study the usefulness of the NasOral system for denitrogenation prior to anesthetic induction for improving pulmonary oxygen storage that maintains SpO2 within the normal range during induced apnea and facilitates apneic oxygenation.

MATERIAL AND METHODS

To establish the study population of 125, five hospitals of the Valencian Community (Spain) enrolled patients scheduled for elective procedures under general anesthesia. The patients were preoxygenated using the NasOral system (denitrogenation). For two minutes, the patients inhaled oxygen through the nose (FiO2 1) at a flow rate of 8-10 l/min (never less than the patient's own minute volume) and exhaled orally through a unidirectional valve. We measured time of apnea with SpO2 > or = 96% to assess the usefulness of the device for denitrogenation. We also measured PetCO2 after endotracheal intubation and after maximum time of apnea (< or = 10 minutes) to assess use of the device for apneic oxygenation during laryngoscopy.

RESULTS

We found no significant differences with regard to age, sex, ASA or Mallampati classification among patient groups enrolled at the participating hospitals. Cox's regression analysis was used to determine relative risk of SpO2 < 96%. At 10 minutes post-apnea, 88.8% of all patients maintained SpO2 > or = 96%. However, SpO2 > 96% was maintained by 94.1% in the Mallampati I group and by 84.1% in the Mallampati II group. SpO2 fell below the cut-off (< 96%) in 33.3% of obese patients and in 7.5% of non-obese patients. Analysis of the likelihood of SpO2 < 96% associated with the variables of obesity, sex, age, ASA and Mallampati classification was significant only for obesity, for which a risk of 1.95 was calculated relative to non-obesity (95% CI 1.14-3.35). The NasOral system allows performance of direct laryngoscopy for oral tracheal intubation, maintaining oxygen flow through the permeable airway to facilitate apneic oxygenation.

CONCLUSIONS

The NasOral system facilitates denitrogenation before induction of anesthesia in all patients with permeable nasal fossae as well as apneic oxygenation during laryngoscopy.

Sodium arsenite reduces proliferation of human activated T-cells by inhibition of the secretion of interleukin-2

Arsenic (As) is a common metalloid which contaminates drinking water in several regions of the world and chronic exposure is associated with skin, lung, bladder, and kidney cancer. Previous studies suggest that arsenic exposure leads to a diminution of phytohemaglutinin (PHA) stimulated T cell proliferation in humans. In order to understand the mechanism of this suppression, the effect of As was evaluated on the expression of CD25, and IL-2 secretion in human peripheral blood mononuclear cells (PBMC). Inhibition of proliferation was observed in all donors studied. Most of the donors did not show any change in the expression of CD25, but IL-2 secretion was inhibited in 6 of the 7 donors tested. Proliferative inhibition was due to a suboptimal levels of IL-2 secreted by lymphocytes, since the addition of recombinant IL-2 to the cultures reversed in a dose-dependent fashion the inhibitory effect of As. The determination of the mRNA of IL-2 and the intracellular IL-2 levels demonstrated that the inhibition is not at the transcriptional level. Electron microscopy studies revealed that cellular ultrastructure in Golgi apparatus, mitochondria, cytoskeleton, and perinuclear membrane were altered. These alterations suggest that due to sodium arsenite effects on cytoskeleton, the intracellular secretion of proteins is affected, including the one of IL-2, leading to an impaired proliferation of the T cells when stimulated with PHA.

Therapeutic uterine-cervix cancer vaccines in humans

Infection with high-risk human papillomavirus (HPV) types is involved in early stages of uterine=cervix cancer development. The virally encoded E6 and E7 oncoproteins behave as tumor-specific antigens and represent targets for a vaccine designed to control HPV-induced tumors. Using either proteins or peptides based on E6 and E7 oncoproteins of HPV16 and 18, phase I clinical trials of therapeutic vaccines against HPV-associated cervical cancers have recently been reported. Although the effectiveness of these vaccines cannot be evaluated in such small studies, they constitute an important step toward the development of therapeutic uterine=cervix cancer vaccines. A polytope DNA vaccination approach combined with immunomodulatory cytokines may offer an excellent strategy to reduce the risk of relapse and metastasis following conventional therapies.

[Cyclosporosis. Report of a clinical case in Concepción, Chile]

Cyclospora cayetanensis is a newly recognized parasite widely distributed throughout the world, and isolated from children, immunocompetent adults and HIV infected individuals. The clinical manifestations of the infection are watery prolonged diarrhea, anorexia, fatigue, nausea, bloating and weight loss. In immunocompetent individuals, diarrhea is usually self limited but may last several weeks. In immunocompromised hosts it is prolonged, severe and can be associated with biliary tract involvement. We report a 50 years old female that, five days after returning from Cuba, presented with low grade fever, anorexia, fatigue, explosive diarrhea and weight loss. Physical examination was normal. A stool specimen contained many organisms with morphological features of Cyclospora caetanensis. The diagnosis was confirmed at the Centers for Disease Control (Atlanta Ga).

[Frequency of human trichinosis in Concepción and Arauco, Chile: study in autopsied persons at the Concepción Medico-Legal Service. June 1996-March 1997]

The frequency of trichinosis was determined in 300 dead persons, residents in the provinces of Concepción and Arauco, and requiring necropsy at the Servicio Medico Legal of Concepción. Diaphragm muscle samples were taken from June 1996 to March 1997. The diagnosis was made by trichinoscopy and artificial digestion techniques. Five samples (1.67%) were positive. There was not differences between sexes. Positive cases were found mainly among 30 to 49 years old people belonging to middle-lower class. Both diagnostic techniques showed different sensitivity as a consequence of the parasitic load and on the contrary, the artificial digestion was less sensitive when the cyts were fully calcified.

Patterns of drug, alcohol and tobacco use among high school students in Santiago, Chile

A survey using a self-administered questionnaire, based on a sample of 1,240 students from four public schools in Santiago, showed that 70.1 per cent of the students used alcohol, 56.3 per cent tobacco, 7.3 per cent cannabis, 2.5 per cent tranquillizers, 1.9 per cent stimulants and 0.7 per cent tranquillizers together with stimulants. Frequent alcohol consumption was found among 14.5 per cent of the students, 11.1 per cent of them smoked more than six cigarettes a day and 1.4 per cent smoked cannabis more than once a week. Consumption of these substances were more frequent among students who came from presumably more affluent residential neighbourhoods. Easy access to drugs played an important role in the occurrence of drug abuse.

GLC determination of griseofulvin in human plasma

A specific and quantitative GLC method for the determination of griseofulvin in human plasma is described. The method involves extraction with ether, evaporation, addition of the internal standard dissolved in benzene, and GLC analysis using an electron-capture detector. The sensitivity of the method is 0.05 mug/ml of plasma. The results obtained with this specific GLC method were compared with the results obtained with the more frequently used spectroflurometric method by analyzing duplicate plasma samples obtained from 12 subjects following a single dose of griseofulvin. It was deduced that the 30% higher plasma levels obtained spectrofluormetrically were due to the coextraction and presence of the metabolite 6-demethylgriseofulvin in the assay solutions.