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).     

The effect of outflow pressure upon thoracic duct lymph flow rate in fetal sheep.

Edema develops when lymph does not return to the venous circulation at a rate equal to the rate of capillary filtration. Fetal sheep develop edema as well as an increased central venous pressure while undergoing atrial pacing at 320 beats per min. We hypothesized that the increased central venous pressure augmented the appearance of fetal edema by impairing the return of thoracic duct lymph to the venous circulation. To investigate this hypothesis, we studied the effect of outflow pressure upon thoracic duct lymph flow in 10 unanesthetized fetal sheep who had low resistance lymph catheters placed in the cervical thoracic duct near its junction with the left jugular vein. After the ewe and fetus recovered for 5 d, we altered the outflow pressure of the lymph catheter by adjusting its height with respect to amniotic fluid pressure and measured the resultant change in thoracic duct lymph flow rate. We found that lymph flow rate was constant over the range of outflow pressures (central venous pressures) normally encountered but decreased in a linear fashion at pressures greater than 0.68 kPa (5.1 torr). Lymph flow stopped at an outflow pressure of 2.40 kPa (18 torr). The data points are best fit by two lines obtained by a piecewise linear regression rather than a single line obtained from a linear regression. We conclude that fetal thoracic duct lymph flow is sensitive to elevations in outflow pressure. Lymph flow begins to diminish at outflow pressures corresponding to central venous pressures commonly encountered in pathologic conditions and may augment the appearance of fetal edema.     

Small-dose oral iron absorption test in anaemic and non-anaemic elderly hospitalized patients

Abstract: The small-dose (20 mg) oral iron absorption test (OIAT) was performed in 76 hospitalized elderly patients and 30 healthy adults. Of the elderly patients, 34 were considered as iron deficient (serum ferritin level <20 μg/L) of whom 23 were anaemic and 11 not anaemic, 21 had the anaemia of chronic disorders (ACD) and another 21 were non-anaemic patients with a normal serum ferritin level. There was a significant inverse correlation between the serum ferritin level as a measure of iron store and the maximum increase in serum iron during a 3-h test (C_max), in the elderly as well as in the healthy adult group. A decision limit of 80 μg/dL for C_max is a good discriminant between absent (serum ferritin <20 μg/L) and adequate body iron stores. Sixty-eight per cent of the patients with a serum ferritin level <20 μg/L but virtually none of the ACD patients, non-anaemic elderly inpatients with normal serum ferritin levels and healthy adults had a C_max level >80 μg/L. Although further investigation is needed before the OIAT can be recommended as a valuable test for evaluating iron absorption, predicting mild iron deficiency and differentiating between different categories of anaemia, it seems worthwile that more effort should be done to validate this simple and safe test.     

Postmenopausal HRT is not independent risk factor for dural sinus thrombosis

While a dural sinus thrombosis (DST), is a well-known consequence of the use of oral contraceptives, the role of hormone replacement therapy (HRT) in DST was not previously evaluated. We report two postmenopausal women, presenting with DST under HRT. Antiphospholipid antibodies in one case and borderline protein S deficiency in another were diagnosed. Only five cases of DST under HRT were previously reported and in two of them additional prothrombotic risk factors were found. According to these and previous cases, HRT is not an independent risk factor for DST.     

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.