Thoracic Section Research Articles

Assessment of quality of life in patients with non-operated pancreatic cancer after videothoracoscopic splanchnicectomy.

IntroductionPancreatic tumours are a crucial medical issue. The majority of patients report sick in the late stage of carcinoma clinical advancement, which considerably limits the possibility of surgical treatment. Pancreatic cancer patients with no other alternative but palliative treatment constitute a large group.AimTo assess pain intensity levels and quality of life of pancreatic cancer patients after videothoracoscopic splanchnicectomy.Material and methodsBetween 2001 January and 2010 November in the Department of Thorax, General Surgery and Oncology of the Medical University of Lodz 262 patients with pancreatic tumours were hospitalized. In 121 cases grade 3 and grade 4 tumours were observed. Hundred and twenty-one videothoracoscopic procedures of sympathetic trunk and ganglion excision were performed in 89 patients.ResultsBefore the procedure the pain intensity level according to VAS was 5.66 (3.9-7.2; SD 1.24) in the trial group and 5.46 (4.1-7.1; SD 1.15) in the control group. The quality of life average assessment in both groups did not differ statistically (p = 1.07) and was 46.3 (32-66; SD 0.92) in patients before the operation and in the control group 50.3 (41-63; SD 0.75). On the 7th postoperative day the pain intensity on average was 2.33 (1.2-3.9; SD 0.78) and 4.57 (3.6-5.5; SD 0.69) respectively. One week after the procedure the quality of patients’ life was estimated at 64.1 (39-83; SD 1.38) and in the control group at 52.2 (42-65; SD 0.71); the differences are significant (p < 0.05). Thirty days after the procedure 12 patients did not take any painkillers (13.5%), and in the others a considerable decrease of the taken drugs was observed. On average, the pain intensity was estimated at 1.78 (0.6-3.6; SD 0.68). The quality of life, on the other hand, improved considerably in relation to the state prior to the procedure, but increased insignificantly in relation to the state on the 7th postoperative day to 70.9 (52-88; SD 1.14).ConclusionsSplanchnicectomy is a safe method of cancer pain treatment in patients with advanced pancreatic tumours. Videothoracoscopic excision of visceral nerve thoracic section contributes to the statistically significant decrease of cancer pain intensity and considerably improves the quality of patients’ lives.

Variations in local elastic modulus along the length of the aorta as observed by use of a scanning haptic microscope (SHM)

Variations in microscopic elastic structures along the entire length of canine aorta were evaluated by use of a scanning haptic microscope (SHM). The total aorta from the aortic arch to the abdominal aorta was divided into 6 approximately equal segments. After embedding the aorta in agar, it was cut into horizontal circumferential segments to obtain disk-like agar portions containing ring-like samples of aorta with flat surfaces (thickness, approximately 1 mm). The elastic modulus and topography of the samples under no-load conditions were simultaneously measured along the entire thickness of the wall by SHM by using a probe with a diameter of 5 μm and a spatial resolution of 2 μm at a rate of 0.3 s/point. The elastic modulus of the wall was the highest on the side of the luminal surface and decreased gradually toward the adventitial side. This tendency was similar to that of the change in the elastin fiber content. During the evaluation of the mid-portion of each tunica media segment, the highest elastic modulus (40.8 ± 3.5 kPa) was identified at the thoracic section of the aorta that had the highest density of elastic fibers. Under no-load conditions, portions of the aorta with high elastin density have a high elastic modulus.

Jerky/Earthbound facilitates cell-specific Wnt/Wingless signalling by modulating β-catenin-TCF activity

Wnt/Wingless signal transduction directs fundamental developmental processes, and upon hyperactivation triggers colorectal adenoma/carcinoma formation. Responses to Wnt stimulation are cell specific and diverse; yet, how cell context modulates Wnt signalling outcome remains obscure. In a Drosophila genetic screen for components that promote Wingless signalling, we identified Earthbound 1 (Ebd1), a novel member in a protein family containing Centromere Binding Protein B (CENPB)-type DNA binding domains. Ebd1 is expressed in only a subset of Wingless responsive cell types, and is required for only a limited number of Wingless-dependent processes. In addition, Ebd1 shares sequence similarity and can be functionally replaced with the human CENPB domain protein Jerky, previously implicated in juvenile myoclonic epilepsy development. Both Jerky and Ebd1 interact directly with the Wnt/Wingless pathway transcriptional co-activators β-catenin/Armadillo and T-cell factor (TCF). In colon carcinoma cells, Jerky facilitates Wnt signalling by promoting association of β-catenin with TCF and recruitment of β-catenin to chromatin. These findings indicate that tissue-restricted transcriptional co-activators facilitate cell-specific Wnt/Wingless signalling responses by modulating β-catenin-TCF activity.

Lung function evaluation before surgery in lung cancer patients: how are recent advances put into practice? A survey among members of the European Society of Thoracic Surgeons (ESTS) and of the Thoracic Oncology Section of the European Respiratory Society (ERS)

In recent years, an abundant literature related to preoperative evaluation of lung cancer patients has been published. Therefore, the European Respiratory Society (ERS) and the European Society of Thoracic Surgeons (ESTS) agreed to form a task force with the aim of developing new guidelines and recommendations to evaluate the fitness of lung cancer patients undergoing radical treatment. One of the first priorities of the task force members was to assess the state-of-the-art of functional evaluation and perioperative treatment of these patients. A multiplechoice survey covering several aspects of this subject was designed and administered online. This survey aimed at assessing how the recent advances in preoperative evaluation of lung function have been put into practice. More specifically, we focused on the cardiologic evaluation before lung resection, the role of diffusing capacity of the lung for carbon monoxide (DLCO) in predicting complications, and the interpretation of split function studies. We

Heterogeneous expression of endothelial connexin (Cx) 37, Cx40, and Cx43 in rat large veins

Gap junctions are clusters of transmembrane protein channels for intercellular communication and are composed of connexin (Cx). The vascular endothelial cells express Cx37, Cx40, and Cx43. We herein examined the spatial distribution of the endothelial connexins Cx37, Cx40, and Cx43 in rat large veins including the cranial vena cava, thoracic section of the caudal vena cava, and abdominal section of the caudal vena cava. We also examined the mean size of the endothelial cells and quantified the protein expression levels of the endothelial connexins. We found that the large veins heterogeneously expressed Cx37, Cx40, and Cx43 as follows: Cx40 > Cx37 > > Cx43 in the cranial vena cava, Cx37 > Cx43 > > Cx40 in the thoracic section of the caudal vena cava, and Cx40 > Cx43 > > Cx37 in the abdominal section of the caudal vena cava. Double immunostaining of two of the endothelial connexins revealed that the gap-junction plaques were composed of various combinations of endothelial connexins. The mean size of the endothelial cells was large, moderate, or small in the cranial vena cava, the abdominal section of the caudal vena cava, or the thoracic section of the caudal vena cava, respectively. The heterogeneity of the endothelial cells of the rat large veins in terms of the connexin expression suggests that the endothelial cells are differently coupled in the large veins. The present data are useful for investigating, for example, disease-related alterations in expression of endothelial connexins in large veins.

Evidence-Based Criteria to Help Distinguish Metastatic Breast Cancer From Primary Lung Adenocarcinoma on Thoracic Frozen Section

The distinction between primary lung adenocarcinoma and metastatic breast carcinoma in patients with a history of breast cancer is difficult by frozen section (FS) analysis. Our experience with 129 FSs from 121 patients with a pulmonary nodule and a history of breast cancer was reviewed. The pretest odds ratio of primary pulmonary carcinoma/metastatic breast carcinoma was 2.6. The incidence of 12 histopathologic features was assessed in a "training set" composed of 20 FSs, 10 with primary lung adenocarcinoma and 10 with metastatic breast cancer. A differential diagnosis model composed of significant pathologic features that favor the diagnosis of primary lung adenocarcinoma (acini, lepidic growth, nuclear pseudoinclusions, and scar) or metastatic breast carcinoma (comedonecrosis, solid nests, trabecular architecture, and cribriform growth) was identified. The external validity of this model was successfully tested by challenging 19 pathologists and trainees with a test set of 20 unknown FSs, supporting the clinical applicability of the diagnostic model.

Thoracoscopic Thoracic Duct Sealing with LigaSure in Two Children with Refractory Postoperative Chylothorax

Chylothorax is an uncommon complication of cardiac surgery. We report two cases of the thoracoscopic management of persistent postoperative chylothorax by thoracic duct thermofusion and section with the LigaSure device. A 6-year-old boy and a 3-year-old girl developed persistent chylothorax following an aortic coarctation repair and a Fontan procedure, respectively. The former presented with a left chylothorax due to direct surgical injury, and the latter, a right chylothorax due to indirect lymphatic rupture secondary to increased venous pressure. In both patients, voluminous chylous drainage persisted for more than 3 weeks despite maximal medical treatment. Ultimately, a right thoracoscopic coagulation and section of the thoracic duct with the 5-mm LigaSure device was performed. The LigaSure is a computer-controlled bipolar diathermy system designed to seal blood vessels up to 7 mm in diameter, with no specific recommendations regarding the lymphatics. The lymph leakage ceased within 2 days in the first patient and immediately in the second one, with no recurrence after oral intake resumption on day 5. Both patients are free of recurrence at 1 year. Thoracoscopic coagulation and section of the thoracic duct above the diaphragm with the LigaSure device appears to be a simple, effective, and safe therapeutic option for treatment of refractory postoperative chylothorax in children.

Adiposity of calf- and yearling-fed Brangus steers raised to constant-age and constant-body weight endpoints

We tested the hypothesis that fatty acid biosynthesis and adipocyte diameter and volume would be greater in s.c. and i.m. adipose tissues of calf-fed steers than in yearling-fed steers at a constant BW, due to the greater time on feed for the calf-fed steers. Conversely, we predicted that the capacity for s.c. and i.m. preadipocytes to divide, as estimated by 3H-thymidine incorporation into DNA, would be greater in the less mature adipose tissues of calf-fed steers and in yearling-fed steers at 16 mo of age than in yearling-fed steers fed to 18 mo of age. Brangus steers were fed a corn-based finishing diet as calves (calf-fed; n = 9) or yearlings (n = 4) to 16 mo of age (CA yearling-fed); another group of yearlings (n = 5) was fed to a constant-BW end point of 530 kg (CW yearling-fed). Both groups of yearling-fed steers had free access to native pasture until 12 mo of age. At slaughter, the fifth to eighth thoracic rib section of the LM was removed, and fresh s.c. and i.m. adipose tissues were removed for in vitro incubations. There were no differences in the number of s.c. adipocytes/g or mean peak volumes of adipocytes across production groups (P > or = 0.14). However, s.c. adipose tissue of CA yearling-fed steers contained greater proportions of smaller adipocytes (<1,500 pL) than calffed or CW yearling-fed steers, and similar results were observed for i.m. adipose tissue. Acetate incorporation into total lipids was greater (P = 0.02) in s.c. adipose tissue of CA yearling-fed steers than in calf-fed or CW yearling-fed steers, and tended to be different (P = 0.10) across production groups in i.m. adipose tissue. The production system x cell fraction interaction was significant (P = 0.03) for s.c. adipose tissue DNA synthesis, which was greatest in adipocytes from CA yearling-fed steers, whereas there were no differences across production system in stromal vascular (SV) DNA synthesis. For i.m. adipose tissue, DNA synthesis was greatest in adipocytes and SV cells from CA yearling-fed calves, and was greater in SV cells than in adipocytes (both P = 0.01). Therefore, stage of adipose tissue development more strongly influenced fatty acid synthesis, adipocyte volume, and DNA synthesis than age at sampling, final BW, or time on the finishing diet.

Morphological traits of the “Pantesco” donkey

The Pantelleria donkey is mentioned in prestigious zootechnical texts and treatises of the late 19th and early 20th century Authors such as Chiari, Mascheroni, Dechambre and others. In ancient times, when the Arab colonial extension in the Mediterranean reached its peak, a number of donkeys was transferred to the isle of Pantelleria southwest from Sicily. They served as draft animals and means of locomotion. In this environment - scarcely suitable for the breeding of farm animals, considering the geo-morphological conditions of the island - one of the most precious and valued donkey races of the Mediterranean basin has its origins: the Pantelleria donkey. Unfortunately, during World War II, Pantelleria was transferred in one of the most important theatres of war in the Mediterranean and the few remaining subjects of the race, once highly esteemed and frequently exported, were almost extirpated. Since then, various efforts have been made to recover the “Pantesco” donkey, but only in 1989 the Regional Forest Administration launched a project to reconstitute this particular population. Owing to comprehensive and accurate research, three males and six females with a percentage of 80 to 90% of “Pantesco” blood could be recovered. The aim of this recovery plan was to prevent the loss of a genotype of great historical and biological value - in Sicily no less than in other European and Asian regions. Currently the “Pantesco” donkey population - finally registered at the general index of equine races and populations - consists of 51 subjects.The objective of our study was to determine the morphological type of this donkey population in order to provide useful data for its ethnic identification. The most significant morphometric traits of the thirty “Pantesco” donkeys examined (15 brood-mares, 13 stallions and 2 colts; those born after 2004 -15 subjects - were excluded from measurements ) were measured in an erect position, using Lydtin’s stick, calliper and flexible meter, and the most significant morphometric indices were calculated in order to provide for a reliable identification of the morphological type. The data obtained - mean values ± sd - (withers height:123.35±4.28cm; rump height: 129.43±4.43cm; chest height: 51.88±3.38cm; chest breadth: 28.61±6.66cm; body length: 124.82±8.86cm; lateral conformation body index :99.12±4.71; longitudinal thoracic section index: 41.65±2.42; body proportion index: 84.58±3.79; thorax height index: 42.05±2.07; pelvic index: 27.82±4.16; head length index: 42,28±1.53 and dactylo-thoracic index: 11.28±0.85 ), suggest that the “Pantesco” population can be assigned to the dolichomorphic type.

SU‐FF‐T‐388: Secondary Radiation Doses From CyberKnife SRS/RT

Purpose: Because of extensive use of conventional x‐rays in CyberKnife SRS/RT for treatment tracking and large number of monitor units (MU) in beam delivery, it is of great concerns of potential secondary radiation risks for patients with benign lesions. This study intend to determine the total secondary radiation dose and its components from both Linac and conventional x‐rays, to estimate the risks, and to assist to better manage frequency of x‐rays acquisition for treatment tracking and better guide through the treatment planning. Comparison with other modalities will also be discussed.Method and Materials: A human phantom was constructed from the Accuray head phantom adjacent to a thoracic and pelvic body section from a commercial humanoid phantom. Measurements were taken at the surface and depth for both high‐energy photons and conventional x‐rays, respectively. Thermoluminescent dosimeter (TLD) chips were placed at 0, 10, 20 and 30cm from the pseudo isocenter. At depth, TLD chips were covered with bolus material for backscatter and/or dose buildup.Results: The secondary radiation dose from conventional x‐rays was about 0.1cGy per exposure inside the radiation field and fell off rapidly outside. The secondary dose from the high‐energy photons was approximately 0.6cGy per 100MU at the distance 10cm from the pseudo‐isocenter and fell off gradually. On average, the total secondary dose to a patient under CK SRS/RT would be 84, 42 and 40cGy at 10, 20 and 30cm away from the pseudo‐isocenter, respectively. Conclusion: The secondary radiation dose to a patient under CK SRS/RT could be significant and high as compared to other similar modalities. During patient treatment, the frequency of x‐rays acquisition should be carefully evaluated between the clinical necessity and potential radiation risks. This is also true in the process of treatment plan development during which the number of fractions and MUs would be determined.

TU-D-330A-07: A Fast Pseudo-1D Active Contour for Medical Image Segmentation

Purpose: A snake (active contour) is a deformable curve used in medical image processing to localize region boundaries. The time required for snake convergence to a solution is lengthened by increased data set size and complex external energy field computations. A new gradient vector flow (GVF) snake algorithm was developed to increase the convergence speed of the conventional GVF snake algorithm. Method and Materials: The new algorithm reformulates a 2D closed curve to a pseudo‐1D open curve. This transformation reduces the solution search space and the area for external energy field computation. Further, curve deformations are restricted to one dimension, thus reducing the complexity for both deformation and external field computation. A binary 512×512 test image was created and the algorithms were run using each of three initializations. Additionally, both algorithms were applied to a 512×512 thoracic CT section. Results: The new algorithm, on average, converged to a solution for the binary image in 11.1s compared with 14.6s for the conventional algorithm (24% improvement). The greatest gains were seen in the GVF calculation where the mean reduction in time for GVF calculation alone was 2.9s (32% improvement). The time for contour fitting was also consistently decreased, with a mean reduction for fitting of 0.6s (11% improvement). The new algorithm on average converged to a solution for the CT section in 4.01s compared with 7.15s for the conventional algorithm (44% improvement). Area‐of‐overlap measures for the contours generated by both algorithms exceeded 0.97 for both binary and CT test images.Conclusion: A new active contour algorithm was developed, and a consistent speed improvement over the conventional algorithm was measured. This new algorithm is compatible with other optimization techniques and shows potential for processing large medical imagedata sets.Conflict of Interest: S.G.A shareholder R2 Technology, Inc.

Tracheomalacia in oesophageal atresia: morphological considerations by endoscopic and CT study☆

A Tracheomalacia complicates 11-33% of cases of Oesophageal Atresia with distal Tracheo-Oesophageal Fistula. The lesion generally involves only the thoracic segment of the trachea, and it has close anatomical relationships with the mediastinal structures, specially with the aortic arch. We therefore tried to define the most important morphotypes of tracheobronchial malacia by using dynamic fiberoptic bronchoscopy (DFB) and spiral multilayer computed tomography (CT). Between 1999 and 2003 we studied 40 children from two different institutions who had been operated on at birth for oesophageal atresia. All patients were been submitted to DFB, and the positive cases underwent examination by CT with an iodinated contrast medium. CT angiographic images of great vessels and multiplanar and three-dimensional images of the airways (virtual broncoscopy and broncography) were obtained for morphological evaluation. Twenty-five patients (62%) tested positive for malacia using DBF and all were also confirmed by CT study. In 11 cases (46%), the malacia was located at the thoracic section of the trachea, which was occluded by compression of the aorto-innominate complex. A simple intrinsic tracheomalacia without any vascular compression was present in eight cases (33%), while in five cases (21%), the malacia was complex. A correct morphological analysis of the malformed segment permitted 'tailored surgery' for each individual patient, allowing us to take account of the type of malacia, its length, and the compressive action exercised by the mediastinal great vessels.

Systemic Microcirculation after Complete High and Low Thoracic Spinal Cord Section in Rats

Spinal cord injury (SCI) produces multiple systemic and metabolic alterations. Although some systemic alterations could be associated with ischemic organ damage, little is known about microvascular blood flow (MVBF) in organs other than the spinal cord after acute SCI. We used laser Doppler flowmetry in anesthetized rats to assess MVBF in several tissues before and after complete T-2 and T-9 SCI at 1 h and on days 1, 3, and 7 post-SCI. Mean arterial blood pressure (MAP), heart rate and hematologic variables also were recorded. MAP changes after T-2 injury were not significant, while MAP decreased significantly 1 h after T-9 injury. Statistically significant bradycardia occurred after T-2 injury at 7 days; statistically significant tachycardia occurred after T-9 injury at 1, 3, and 7 days. Hematocrit significantly increased at day 1 and decreased at days 3 and 7 after T-2 injury. SCI was associated with significant decreases in MVBF in liver, spleen, muscle and fore footpad skin. Changes in MVBF in hind footpad skin and kidney were not significant. Changes were more pronounced at 1 h and 1 day post-SCI. Significant differences between MVBF after T-2 and T-9 SCI occurred only in liver. MVBF significantly correlated with regional peripheral vascular resistances (assessed using the MAP/MVBF ratio), but not with MAP. In conclusion, organ-specific changes in systemic MVBF that are influenced by the level of SCI, could contribute to organ dysfunction.

Systemic Microcirculation after Complete High and Low Thoracic Spinal Cord Section in Rats

Spinal cord injury (SCI) produces multiple systemic and metabolic alterations. Although some systemic alterations could be associated with ischemic organ damage, little is known about microvascular blood flow (MVBF) in organs other than the spinal cord after acute SCI. We used laser Doppler flowmetry in anesthetized rats to assess MVBF in several tissues before and after complete T-2 and T-9 SCI at 1 h and on days 1, 3, and 7 post-SCI. Mean arterial blood pressure (MAP), heart rate and hematologic variables also were recorded. MAP changes after T-2 injury were not significant, while MAP decreased significantly 1 h after T-9 injury. Statistically significant bradycardia occurred after T-2 injury at 7 days; statistically significant tachycardia occurred after T-9 injury at 1, 3, and 7 days. Hematocrit significantly increased at day 1 and decreased at days 3 and 7 after T-2 injury. SCI was associated with significant decreases in MVBF in liver, spleen, muscle and fore footpad skin. Changes in MVBF in hind footpad skin and kidney were not significant. Changes were more pronounced at 1 h and 1 day post-SCI. Significant differences between MVBF after T-2 and T-9 SCI occurred only in liver. MVBF significantly correlated with regional peripheral vascular resistances (assessed using the MAP/MVBF ratio), but not with MAP. In conclusion, organ-specific changes in systemic MVBF that are influenced by the level of SCI, could contribute to organ dysfunction.

Dual effect of GABA on descending monosynaptic excitatory postsynaptic potential in frog lumbar motoneurons

Monosynaptic excitatory postsynaptic potentials (EPSPs) evoked by stimulating ipsilateral ventrolateral column (VLC) in the thoracic section were recorded in lumbar motoneurons within the isolated spinal cord of the frog Rana ridibunda. Bath application of the selective GABA B receptor agonist (−)-baclofen (0.05 mM) caused a reduction in the peak amplitude of VLC EPSP. Baclofen did not cause any consistent change in the membrane potential or in the EPSP waveform within frog motoneurones. The selective GABA B receptor antagonist saclofen (0.1 mM) completely blocked the effect of (−)-baclofen on VLC EPSP. A decrease in VLC EPSP peak amplitude was also observed during GABA (0.5 mM) application. Unlike (−)-baclofen, inhibition of VLC EPSP induced by GABA was accompanied by a shortening of the EPSP time course and a reduction in membrane input resistance within lumbar motoneurons. The decrease in VLC EPSP peak amplitude induced by (−)-baclofen and GABA was accompanied by an increase in the paired-pulse facilitation. These data provide evidence for a dual pre- and postsynaptic GABAergic inhibition of the VLC monosynaptic EPSP in lumbar motoneurons within the frog spinal cord.

Mehrsegmentale Bildfusion an der Wirbelsäule / Multisegmental Image Fusion of the Spine

Fusion of medical images is a technique that permits the correlation of homologous anatomical structures in different imaging modalities on the basis of a spatial transformation of the data sets. CT and MRI of the spine provide complementary information of possible relevance for diagnostic and therapeutic decisions. Methods enabling a multisegmental CT-MRI fusion of the spine were developed. These solve the problem of altered spatial relationships of the individual anatomical structures due to differing patient positioning in successive data acquisitions. Routine clinical CT and MRI data of a thoracic section of the spine were obtained and transferred to a PC-workstation. Following segmentation of the CT-data, landmarks for each individual vertebra were defined in the CT and MRI data. For each individual vertebra the algorithm we developed then carried out a rigid registration of the CT information to the MR data. The fused data sets were presented as colour-coded images or on the basis of dynamic variation of transparency. To assess registration precision, fiducial registration errors (FRE) and target registration errors (TRE) were calculated. The algorithm permitted multi-segmental image fusion of the spine. The average time required for defining the landmarks was 22 seconds per landmark for CT, and 34 seconds per landmark for MR. The average FRE was 1.53 mm. The TRE for the vertebrae was less than 2 mm. The colour-coded images were particularly suitable for assessing the contours of the anatomical structures, whereas dynamic variation of the transparency of overlapping CT images enabled a better overall assessment of the spatial relationship of the anatomical structures. The algorithm permits precise multi-segmental fusion of CT and MR of the spine, which was not possible using current fusion-algorithms due to variations in the spatial orientation of the anatomical structures caused by different positioning of the axial skeleton in successive examinations.

Imbalances in regional lung ventilation: a validation study on electrical impedance tomography.

Imbalances in regional lung ventilation, with gravity-dependent collapse and overdistention of nondependent zones, are likely associated to ventilator-induced lung injury. Electric impedance tomography is a new imaging technique that is potentially capable of monitoring those imbalances. The aim of this study was to validate electrical impedance tomography measurements of ventilation distribution, by comparison with dynamic computerized tomography in a heterogeneous population of critically ill patients under mechanical ventilation. Multiple scans with both devices were collected during slow-inflation breaths. Six repeated breaths were monitored by impedance tomography, showing acceptable reproducibility. We observed acceptable agreement between both technologies in detecting right-left ventilation imbalances (bias = 0% and limits of agreement = -10 to +10%). Relative distribution of ventilation into regions or layers representing one-fourth of the thoracic section could also be assessed with good precision. Depending on electrode positioning, impedance tomography slightly overestimated ventilation imbalances along gravitational axis. Ventilation was gravitationally dependent in all patients, with some transient blockages in dependent regions synchronously detected by both scanning techniques. Among variables derived from computerized tomography, changes in absolute air content best explained the integral of impedance changes inside regions of interest (r(2) > or = 0.92). Impedance tomography can reliably assess ventilation distribution during mechanical ventilation.

Vascular proliferation and transforming growth factor-β expression in pre- and early stage of diabetes mellitus in Otsuka Long-Evans Tokushima fatty rats

The roles of transforming growth factor (TGF)-β1 in vascular proliferation, atherosclerosis, and plaque still remain controversial. TGF-β1 has been previously reported to inhibit the proliferation and migration of vascular smooth muscle cells and endothelial cells, in vitro. On the other hand, administration or transgenic overexpression of TGF-β1 enhances extracellular matrix synthesis and cellular hyperplasia of the intima and media in the normal artery and injured artery in vivo. We evaluated the correlation of arterial proliferation with plasma levels of TGF-β1 and TGF-β receptor type II, respectively, in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, a new strain of spontaneous non-insulin-dependant diabetes mellitus (NIDDM) models. OLETF rats ( n=30) were divided into three groups aged 5, 15, and 30 weeks. Long-Evans Tokushima Otsuka (LETO) rats ( n=30) were used as age-matched non-diabetic controls. Plasma TGF-β1 and insulin were determined by enzyme-linked immunosorbent assay. Immunoreactive TGF-β receptor type II antigen was detected by immunohistochemistry on the thoracic artery. Arterial media area was measured microscopically. Oral glucose tolerance test was performed to examine the stage of diabetes mellitus. The thoracic aorta wall section area increased significantly from the age of 15 weeks in OLETF rats, versus LETO rats. In both OLETF and LETO rats, plasma TGF-β1 increased significantly from the age of 15 weeks. In OLETF rats, plasma TGF-β1 increased significantly over that in LETO rats ( P<0.001). Furthermore, TGF-β receptor type II was detected on aortic wall as strong signals in OLETF rats, but only weakly in LETO rats. OLETF rats showed hyperinsulinemia and insulin resistance from the age of 15 weeks. With oral glucose tolerance test, from the age of 15 weeks, the high glucose level in OLETF rats was prolonged to 2 h after loading, and the insulin levels at both fasting and after loading were significantly higher than those of LETO rats ( P<0.001). There are significant linear relations between plasma TGF-β1 antigen and aorta wall section area, and plasma TGF-β1 antigen and fasting insulin level ( P<0.001, respectively). We found that plasma TGF-β1 and vascular TGF-β type II receptors existed to a greater extent in pre- and early stages of diabetes mellitus (DM) in OLETF rats compared with LETO rats. The greater extent of each in OLETF rats was associated with hyperinsulinemia and/or vascular thickening.

Local capsaicin application to the stellate ganglion and stellatectomy attenuate neurogenic inflammation in rat bronchi

The present study investigated the contributions of vagal and nonvagal sensory nerve fibers on neurogenic inflammation in rat bronchial airways. A surgical procedure was developed via the rat mediastinum ventral intercostal space to prepare an intercostal opening without causing pneumothorax for performing stellate ganglionectomy alone, thoracic vagus nerve section alone, and stellatectomy plus thoracic vagotomy, and for injecting capsaicin (2 μl, 10 mg/ml) and 6-hydroxydopamine (2 μl, 50 mg/ml) into the ganglion. One week later in our procedure, we investigated if neurogenic inflammation induced by an intravenous injection of capsaicin (300 nmol/ml/kg) and innervation density of substance P-immunoreactive sensory axons could be decreased after chronic denervation in the rat lower airways. The major findings were that surgical removal of the right stellate ganglion and local capsaicin application resulted in a significant attenuation of neurogenic plasma extravasation in the right bronchial tree evoked by systemic capsaicin application. Reduction of neurogenic plasma extravasation was totally abolished by combined stellatectomy and thoracic vagotomy. The number of substance P-containing axons was also greatly decreased following these surgical and capsaicin treatments. It is concluded that sensory nerve fibers from both vagal source and nonvagal (spinal) source, which associated with the stellate ganglion, contributed significantly to neurogenic inflammation in the bronchial airways with a slightly higher contribution from the vagus nerve.

Effects of spinal section and of positive-feedback excitatory reflex on sympathetic and heart rate variability.

The sympathetic outflow appears to be capable of displaying a rhythmicity synchronous with cardiovascular Mayer's waves even after spinal section. To test the hypothesis that spinal sympathetic low frequency (LF) oscillation can be enhanced during sympathetic excitation, we recorded cardiac sympathetic nerve activity (SNA), R-R interval, arterial pressure, and ventilation in 9 unanesthetized decerebrate-vagotomized cats before and after C1 spinal section. LF and high frequency (HF) components were detected in the variability of SNA, R-R interval, and systolic arterial pressure both before and after spinal section. In this latter condition, a significant coherence between LF(SNA) and LF(R-R) was present in 5 animals, whereas HF(SNA) and HF(R-R) were correlated in 4 animals. During an excitatory sympathetic spinal reflex elicited by aortic constriction, the efferent sympathetic firing was markedly enhanced (from 7+/-2 to 33+/-7 spikes/s); concomitantly, the powers of both LF(SNA) and HF(SNA) were also increased. Coherence between LF(SNA) and LF(R-R) became significant in all cases, whereas HF(SNA) and HF(R-R) became correlated in 6 animals. In 3 animals, the reflex sympathetic excitation was no longer elicitable after interrupting a vast contingent of sympathetic afferents by means of thoracic dorsal root section. We report for the first time that LF and HF oscillations are detectable in SNA, R-R interval, and systolic arterial pressure variabilities of decerebrate-vagotomized spinal cats and that an excitatory spinal reflex is capable of increasing the power of both SNA spectral components.