The antibody response to specific immune complexes is under genetic control and correlates with the expression of a recurrent idiotype

The primary antigen-specific antibody response of various strains of mice to TEPC-15/PnC immune complexes has been examined. We found that both BALB/c and C3H mice were good responders to the PnC antigen; however, C3H mice were low responders, whereas BALB/c mice were high responders to the TEPC-15/PnC complexes. Using congenic strains on the C3H and BALB/c background, we have shown that the response to the complexes is not restricted by gene products of the H-2 complex or by the Igh (allotype) locus. However, responsiveness may be controlled by genes linked to the Igh locus, since we have shown that strains that are Ighj, Ighd, and Ighf are low responders, whereas strains that are Igha, Ighb, and Ighe are high responders to the immune complex. Moreover, responsiveness correlates with the expression of the T15 Id as measured using the anti-T15 monoclonal antibody, AB1-2. Thus, strains such as BALB/c, BALB.B, BALB.K, and CB-20, which express high levels of T15 (AB1-2) Id in their PFC response to PnC are relatively high responders to TEPC-15/PnC complexes, whereas C3H, C3H.SW, and C3H-OH, which express low levels of the T15 (AB1-2) Id, are low responders to the complexes. Finally, we found that BALB/c mice are high responders to complexes formed with T15+ antibodies, whereas they are low responders to complexes formed using T15- antibodies. The results suggest that the antigen-specific response to these immune complexes is Id-restricted.     

Incidence of Chest Tube Malposition in the Critically Ill: A Prospective Computed Tomography Study

Background: Malposition of percutaneously inserted chest tubes is considered as a rare complication in critically ill patients. Its incidence, however, remains uncertain. The aims of the study were to assess the true incidence of chest tube malposition in critically ill patients and to identify predicting factors.

Methods: The authors prospectively studied 122 chest tubes percutaneously inserted in 75 consecutive critically ill patients. For clinical reasons independent of the study, thoracic computed tomography scanning was performed in 63 patients, allowing direct visualization of 106 chest tubes. Based on these findings, chest tube position was classified as intrapleural, intrafissural, or intraparenchymal. Factors predicting chest tube malposition were analyzed by univariate and multivariate analysis.

Results: The mean delay between chest tube placement and thoracic scan was 3.5 +/- 2.9 days. Twenty-two chest tubes were diagnosed as being intrafissural (21%), and 10 were diagnosed as being intraparenchymal (9%). The only predicting factor associated with the risk of malposition was the use of a trocar for the percutaneous insertion of the chest tube (P = 0.032).     

Smoking, alcohol drinking and cancer risk for various sites of the larynx and hypopharynx. A case-control study in France.

The aim of this work was to study the effects of alcohol and tobacco consumption on laryngeal and hypopharyngeal cancer and to compare these across subsites (glottis, supraglottis, epilarynx, hypopharynx). Data from a hospital-based case-control study including 504 male cases (105 glottic cancers, 80 supraglottic cancers, 97 epilaryngeal cancers and 201 hypopharyngeal cancers) and 242 male controls with non-respiratory cancers were used for this analysis. Information about sociodemographic characteristics, detailed alcohol and tobacco consumption was collected through face-to-face interviews. Statistical analysis used logistic regression, and subsites were compared with polytomous logistic regressions. The risk of laryngeal and hypopharyngeal cancer increased with tobacco (duration and amount) and alcohol consumption; the effect of both agents was multiplicative. From the lowest to the highest consumption level, odds ratios ranged from 1.4 to 5.9 among regular drinkers and from 3 to 44 among current smokers. Risks among ex-smokers were approximately one-third of those for current smokers. Slightly elevated odds ratios were associated with consumption of black tobacco (OR=1.2) and hand-rolled cigarettes (OR=1.2). The risk of cancer was not clearly associated with the type of alcoholic beverage. Subsites did not differ significantly according to tobacco smoking, but differed according to alcohol consumption, with a significantly higher increased risk for hypopharyngeal than for glottic and supraglottic cancers.     

A study of the interaction of alcohol drinking and tobacco smoking among French cases of laryngeal cancer.

Laryngeal cancer represents an important cause of cancer in France, and the individual effects of alcohol and tobacco on this cancer site are well known. However the problem of the interaction between these agents is less extensively documented, and the role of the high consumptions of alcohol has not been studied frequently. A case-control analysis was undertaken to investigate the joint effect of alcohol and tobacco by comparing 197 glottic and 214 supraglottic cancer cases to 4135 controls representative of the French general population. Heavy drinkers were available from the two groups of cases, the highest alcohol category being equivalent to a consumption of more than 2 litres of wine per day. The relative risks estimated for heavy drinkers and smokers were high, and the results indicated an even stronger effect of alcohol drinking and tobacco smoking on the upper part of the laryngeal region. Additive and multiplicative models were fitted to the data. The multiplicative hypothesis was found to be the most appropriate, implying that the risks associated with alcohol and tobacco multiply when the exposures occur simultaneously. The public health implications of this result and the contribution of heavy drinkers and smokers to the frequency of upper respiratory and digestive tract cancers are discussed.     

Transbronchial biopsy without fluoroscopy in patients with diffuse roentgenographic infiltrates and the acquired immunodeficiency syndrome

Transbronchial biopsy with the flexible fiberoptic bronchoscope is usually performed with the assistance of fluoroscopy in order to increase diagnostic yield and decrease the incidence of pneumothorax. We have compared the results of transbronchial biopsy performed with or without fluoroscopic guidance in patients with diffuse roentgenographic infiltrates who had or were suspected of having the acquired immunodeficiency syndrome. Neither the sensitivity for Pneumocystis carinii (88.5 versus 92%) nor the percentage of patients developing pneumothoraces after transbronchial biopsy (8.6 versus 11.1%) was significantly different in those patients who had the procedure without fluoroscopic guidance compared with those in whom fluoroscopy was used. There were no patients with significant hemorrhage or deaths in either group. This complication rate compares favorably with other reports of transbronchial biopsy in immunocompromised patients in which fluoroscopy was used. "Blind" transbronchial biopsy is a safe and effective diagnostic procedure in this patient population.     

Long-chain omega-3 fatty acids regulate bovine whole-body protein metabolism by promoting muscle insulin signalling to the Akt–mTOR–S6K1 pathway and insulin sensitivity

The ability of the skeletal musculature to use amino acids to build or renew constitutive proteins is gradually lost with age and this is partly due to a decline in skeletal muscle insulin sensitivity. Since long-chain omega-3 polyunsaturated fatty acids (LC n –3PUFA) from fish oil are known to improve insulin-mediated glucose metabolism in insulin-resistant states, their potential role in regulating insulin-mediated protein metabolism was investigated in this study. Experimental data are based on a switchback design composed of three 5 week experimental periods using six growing steers to compare the effect of a continuous abomasal infusion of LC n –3PUFA-rich menhaden oil with an iso-energetic control oil mixture. Clamp and insulin signalling observations were combined with additional data from a second cohort of six steers. We found that enteral LC n –3PUFA potentiate insulin action by increasing the insulin-stimulated whole-body disposal of amino acids from 152 to 308 μmol kg⁻¹ h⁻¹ ( P = 0.006). The study further showed that in the fed steady-state, chronic adaptation to LC n –3PUFA induces greater activation ( P < 0.05) of the Akt–mTOR–S6K1 signalling pathway. Simultaneously, whole-body total flux of phenylalanine was reduced from 87 to 67 μmol kg⁻¹ h⁻¹ ( P = 0.04) and oxidative metabolism was decreased ( P = 0.05). We conclude that chronic feeding of menhaden oil provides a novel nutritional mean to enhance insulin-sensitive aspects of protein metabolism.