Quantification of traumatic hemomediastinum using transesophageal echocardiography: impact on patient management

STUDY OBJECTIVES: To determine whether the quantitative evaluation of hemomediastinum using transesophageal echocardiography (TEE) is predictive of the presence of a traumatic disruption of the thoracic aorta (TDA) or its branches in patients who have sustained severe blunt chest trauma. DESIGN: Retrospective study. SETTING: ICU of a tertiary referral teaching hospital. PATIENTS: Forty-one patients sustaining severe blunt chest trauma (32 men, nine women; mean age, 43+/-16 years; mean Injury Severity Score, 39+/-22) who underwent a TEE study were divided into two groups, patients with (group TDA+, n=15) or without (group TDA-, n=26) major vascular injury diagnosed using an alternative method such as aortography, surgery, or necropsy. The control group included 41 age- and sex-matched patients with an unremarkable TEE study performed to rule out an intracardiac source of emboli. INTERVENTIONS: The presence of hemomediastinum was quantitatively assessed by measuring the distances between the esophageal scope and anteromedial aortic wall (distance 1), and between the posterolateral aortic wall and left visceral pleura (distance 2) at the level of the aortic isthmus. An observer who was unaware of both medical history and final diagnosis measured the distances. MEASUREMENTS AND RESULTS: In group TDA+, TEE demonstrated aortic injuries in 13 patients, revealed an isolated hemomediastinum in one patient (ruptured intercostal arteries), and was unremarkable in the remaining patient, who sustained a disrupted right subclavian artery. No associated major vessel injuries were diagnosed in the group TDA- (normal aortograms). When compared to the control group, mean distances were greater in patients with chest trauma (distance 1=5.5+/-4.4 mm vs 2.7+/-0.8 mm, p=0.001; distance 2=3.8+/-5.0 mm vs 1.2+/-0.3 mm, p=0.02). The corresponding distances were even greater in group TDA+ when compared with group TDA- (distance 1=8.6+/-5.9 mm vs 3.7+/-1.5 mm, and distance 2=7.1+/-7.0 mm vs 2.0+/-1.7; for both differences, p<0.01). A threshold value of 5.5 mm for distance 1 or 6.6 mm for distance 2 had a sensitivity of 80%, a specificity of 92%, a positive and negative predictive value of 86% and 89%, respectively, for the diagnosis of underlying major vascular injury. CONCLUSIONS: TEE allows quantitative assessment of traumatic hemomediastinum. The presence of a large hemomediastinum requires further evaluation by aortography, even if the thoracic aorta appears normal during the TEE examination, in order to rule out an underlying major vascular injury which may be outside the field of view of the echocardiographer.     

Evaluation of periosteal membranes and coronally positioned flaps in the treatment of Class II furcation defects: a comparative clinical study in humans

The purpose of this study was to compare the clinical effectiveness of connective tissue grafts including periosteum used as a mechanical barrier for guided periodontal tissue regeneration and coronally positioned flaps in the treatment of Class II furcation defects. A total of 28 furcation defects were treated; 14 received a periosteal barrier and 14 received a coronally positioned flap. Reentry surgeries were performed at 6 months. No statistically significant differences were found preoperatively between the two treatment groups with respect to clinical parameters and osseous measurements. Postsurgically, both treatment modalities resulted in a significant decrease in probing depth and a significant gain in clinical attachment, but the differences observed were not statistically significant. The periosteal barrier group presented with a significantly better gain in vertical components of the alveolar bone (1.93 +/- 0.15 mm and 0.20 +/- 0.26 mm for periosteal barrier and coronally positioned flap groups, respectively; P < or = 0.001) and horizontal components of the alveolar bone (1.60 +/- 0.21 mm and 0.13 +/- 0.90 mm for periosteal barrier and coronally positioned flap groups, respectively; P < or = 0.001). The results of this trial indicate that similar clinical resolution of Class II furcation defects can be obtained with periosteal barriers and coronally positioned flaps. Periosteal barriers, however, are a better treatment alternative in achieving bone fill of the furcation area.     

Do viral load and CD8 cell count at initiation of tritherapy influence the increase of CD4 T-cell count?

BACKGROUND: Tritherapies including protease inhibitors improve clinical status and usually increase CD4 T cell count. However, the dissociation between the marked decreases in viral load and the incomplete restoration of CD4 cell counts with a three-drug combination has been reported. We assessed this potential difference among our patients. METHODS: Patients were enrolled when a protease inhibitor was prescribed to them for the first time. Using a computerized medical record (ADDIS), we retrospectively assessed a potential relationship between the increase in CD4 T cells (deltaCD4) at M3, M6 and variables including sex, age, CDC staging, protease inhibitor, prior antiviral therapy, CD8 and viral load at baseline. We used Epi-Info 6.4 and BMDP software. RESULTS: Data were analyzed on 154 patients. The median CD4 T cell count was 157 at baseline, 215 at month 3 and 202 at month 6. The median viral load was 52000 copies at baseline, 530 at month 3 and 500 at month 6. In a univariate analysis, a significant relationship was found between deltaCD4 and CD8 at baseline. A statistically significant negative correlation appeared between the CD8 cell count at baseline and deltaCD4 at M6 (r=-0.28, Pearson). Moreover, we found that there also was a relationship between deltaCD4 and viral load at baseline. There was a correlation between deltaCD4 at M6 and the viral load at M0 (r=0.37, Pearson). In a multiple regression model, after CD8 count at baseline had been accounted for, we found a significant correlation between deltaCD4 and viral load at baseline (multiple r=0.33 at M3, and 0.40 at M6). CONCLUSIONS: Patients with a low viral load do not benefit from as great an increase in CD4 T cell count as others when they receive a tritherapy including protease inhibitors. These results suggest that another mechanism rather than direct viral pathogenicity leads to CD4 T cell destruction. This mechanism may not be efficiently stopped by antiviral therapy, especially protease inhibitors.     

Non-invasive assessment of inspiratory muscle performance during exercise in patients with chronic heart failure

AIMS: The aim of this study was to assess inspiratory performance at rest and during exercise in patients with chronic heart failure in comparison with healthy controls using a non-invasive index: the tension-time index of inspiratory muscles (TTMUS). METHODS: We studied 13 patients with chronic heart failure (57 +/- 7 years) and 10 control subjects (58 +/- 6 years) at rest and during an incremental maximal exercise test. Measurements included breathing pattern (inspiratory time, total time of respiratory cycle, minute ventilation, tidal volume and respiratory frequency), mouth occlusion pressure and mean inspiratory pressure (calculated as follows: 5 x mouth occlusion pressure x inspiratory time). The maximal inspiratory pressure was measured at rest. TTMUS was calculated from the equation: TTMUS = PI/PIMAX x TI/TTOT, where PI/PIMAX is the ratio of mean inspiratory pressure to maximal inspiratory pressure and TI/TTOT is the ratio of mean inspiratory time to total time of the respiratory cycle. RESULTS: At rest, the results in patients showed non-significantly higher mouth occlusion pressure, lower maximal inspiratory pressure (P < 0.001), and a higher ratio of mean inspiratory pressure to maximal inspiratory pressure (P < 0.01). There was no difference in the breathing pattern. TTMUS was thus significantly higher in the patients with chronic heart failure (P < 0.001). At maximal exercise (77 +/- 16 W for patients with chronic heart failure vs 142 +/- 27 W for controls, P < 0.001), the ratio of mean inspiratory time to total time of respiratory cycle, the mouth occlusion pressure and the ratio of mean inspiratory pressure to maximal inspiratory pressure were not different. TTMUS was thus comparable in the two groups. During exercise, at comparable workloads (20, 40 and 60 W), the patients showed higher mouth occlusion pressure (P < 0.01) and a higher ratio of mean inspiratory pressure to maximal inspiratory pressure (P < 0.001), whereas the ratio of mean inspiratory time to total time of the respiratory cycle was similar. TTMUS was thus higher in the patients at each workload (P < 0.05). CONCLUSION: This study shows that the determination of TTMUS at rest and during exercise allows the observation of alterations in inspiratory muscle performance as a result of both reduced inspiratory strength, as measured by the maximal inspiratory pressure, and increased ventilatory drive, as reflected by the mouth occlusion pressure in patients with chronic heart failure. The non-invasiveness of this new index is an additional argument for its use in a clinical setting.     

Unsymmetrically substituted polyamine analogue induces caspase-independent programmed cell death in Bcl-2-overexpressing cells

The polyamine analogue, N1-ethyl-N11-[(cycloheptyl)methyl]-4,8-diazaundecane (CHENSpm)-induced programmed cell death in NCI H157 cells is accompanied by cytochrome c release, the loss of mitochondrial membrane potential, activation of caspase-3, caspase-mediated poly(ADP-ribose) polymerase cleavage, G2-M arrest, and DNA and nuclear fragmentation. Overexpression of Bcl-2 completely inhibits CHENSpm-induced cytochrome c release, caspase-3 activation, and poly(ADP-ribose) polymerase cleavage. However, Bcl-2 does not abrogate CHENSpm-induced programmed cell death. These results suggest that although cytochrome c release and activation of the caspase-3 protease cascade contribute to the rapid and efficient execution of apoptosis, a caspase cascade-independent pathway also exists and can be activated by CHENSpm treatment.     

Prospective study of the risk of Clostridium difficile diarrhoea in elderly patients following treatment with cefotaxime or piperacillin-tazobactam

BACKGROUND: Rates of Clostridium difficile diarrhoea have recently been rising, with the elderly being at highest risk. AIM: To compare the incidence of C. difficile colonization and diarrhoea in elderly patients treated for presumed infection with either empirical cefotaxime (CTX) or piperacillin-tazobactam (PT). METHODS: A prospective, ward-based, crossover study was carried out on two well-matched care of the elderly wards at a UK tertiary care hospital, in patients requiring empirical broad-spectrum antibiotic treatment. RESULTS: There was a highly significant increased incidence of C. difficile colonization (26/34 vs. 3/14, P=0.001) and diarrhoea (18/34 vs. 1/14, P=0.006) in patients who received CTX as opposed to PT. DNA fingerprinting suggested that most infections arose from strains acquired from the hospital environment. CONCLUSIONS: Elderly patients are significantly less likely to develop C. difficile diarrhoea after treatment with PT than after CTX. The source of C. difficile appears to be predominantly from the ward environment.     

Treatment of Helicobacter pylori infection

The article presents information gained from a survey among Norwegian hospitals in March 1997 concerning their treatment of infections with Helicobacter pylori. Altogether 52 hospitals answered the questionnaire. A combination of proton pump inhibitors, metronidazole and clarithromycin was used by 59% as first choice and urea quick test (94%) and urea breath test (42%) as the primary diagnostic procedures, whereas serology was in little use (17%). Besides ordinary ulcer disease, indications for treatment were: ulcer induced by non-steroid anti-inflammatory drugs (79%), gastrooesophageal reflux (37%), non-ulcer dyspepsia (14%) and cancer prophylaxis (14%). The gastro group at the Department of Pharmacotherapeutics at the University of Oslo invited specialists from all health regions to discuss indications for treatment of H pylori, the diagnosis and the role of general practitioners. The extensive use of clarithromycin might be doubtful due to development of resistance. Indications for treatment of H pylori other than ulcer disease and mucosa associated lymphoid tissue lymphoma are still uncertain. Uncritical use of serological tests in primary care should be discouraged. At present there is no uniform strategy for the diagnosis and treatment of H pylori infection, and a coordinated strategy between general practitioners and specialists is needed.     

Surfaces coated with protein layers: a surface force and ESCA study

This paper is structured in two parts. The first briefly reviews a number of lines of published evidence, including direct experimental evidence, supporting the contention that enamel microstructures are time dependent and have a regular periodicity. The second presents the results of a large-scale study designed to test a central assumption underlying most histological ageing approaches in enamel: that the number of cross striations between adjacent striae of Retzius, called the circaseptan interval, are uniform within a tooth and between all teeth in the dentition of an individual. The study uses a sample of 158 anterior teeth from three modern human populations. Teeth were sectioned and circaseptan intervals were determined by dividing measurements of the distance between adjacent striae of Retzius, by cross-striation length. In order to exercise as much procedural rigour as possible, all measurements were made from photomicrographs. Two sections were taken from each tooth, the sampling location within each tooth was recorded, and all populations included multiple teeth from single individuals. Results statistically validate the uniformity hypothesis within the anterior dentition. These, together with the weight of published evidence, suggest that data derived from the use of enamel microstructures in age estimation techniques and growth and development studies, are valid.     

Lipiodol avidity of neuroendocrine liver metastases

AIMS: Lipiodol has been shown to concentrate in most hepatocellular carcinomas as well as in some liver metastases, including those of neuroendocrine origin. Our aim was to determine the proportion of neuroendocrine liver metastases that take up lipiodol and to identify tumour characteristics that predict avidity. METHODS: Avidity was assessed in 12 patients with neuroendocrine liver metastases by performing an abdominal CT scan immediately after selective hepatic arterial injection of 5 ml of unlabelled lipiodol and this was correlated with number and size of lesions as well as angiographic and plain CT scan features. RESULTS: In seven patients the tumours displayed lipiodol avidity (four solitary, three multiple); five patients had non-avid lesions (all multiple). A large dominant liver tumour was the only predictor of avidity (mean diameter of largest lesion 9 cm vs. 3 cm for patients with non-avid tumours: P=0.01). Avidity was not related to vascularity or CT density of lesions. CONCLUSIONS: Although this is a small study, it would appear that approximately 50% of neuroendocrine liver metastases selectively concentrate lipiodol, which could have implications for targeted cancer therapy.