Regional blood flow to canine parietal pleura and internal intercostal muscle

Transcapillary Starling forces in the parietal pleura and the underlying interstitium may potentially contribute to the exchange of fluid across this barrier. However, the extent of blood flow to the parietal pleura has not been measured. Thus, using standard microsphere techniques, we compared blood flow to the parietal pleura, including the subpleural interstitium, with blood flow to the adjacent internal intercostal muscle, as well as with flows to other serous tissues, including mediastinal pleura, pericardium, and parietal peritoneum, in anesthetized dogs that were either breathing spontaneously (n = 9) or ventilated to control arterial PCO2 (n = 5). Blood flow (ml.min-1.g-1) was measured after 20 min of equilibration in four successive body positions: right lateral decubitus, supine, left lateral decubitus, and prone. Overall, flow to parietal pleura was not different in spontaneous [1.07 +/- 0.14 (SE)] and mechanically ventilated animals (0.74 +/- 0.11). Flow to the internal intercostal muscle was significantly less than pleural blood flow, averaging 0.24 +/- 0.03 and 0.16 +/- 0.03 in the same groups, although again there was no effect of ventilation mode. Blood flow to other serous tissues in the thoracic cavity, specifically the mediastinal pleura (0.67 +/- 0.14) and pericardium (0.88 +/- 0.22), was similar to parietal pleural flow, whereas that to the parietal peritoneum was an order of magnitude lower (0.09 +/- 0.02, P less than 0.05). Changing body position had no effect on blood flow to any of the sampled tissues. Blood flow to the dorsal aspect of the chest wall muscle in spontaneously breathing animals tended to be greater than that to lateral or ventral portions of the chest wall.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mediastinal parathyroidectomy with the da Vinci robot

Mediastinal parathyroid glands are often located in a position which is inaccessible through a cervical approach. Because of the significant morbidity of open surgery, the need for minimal invasive approaches is high. More recently, robotic systems have been introduced to refine the dissection and optimize the view in the mediastinal region. We present two cases. The first case is a 34-year-old woman who was diagnosed with primary hyperparathyroidism. Because a bilateral neck dissection disclosed no parathyroid adenoma, we performed a parathyroid sestamibi scan and computed tomographic scan of neck and mediastinum to look for aberrant parathyroid glands. Both showed a parathyroid adenoma in the mediastinum on the left side. The second case is a 66-year-old man. A sestamibi scan showed a parathyroid adenoma of 3 cm in the superior mediastinum which was confirmed by and computed tomographic scan. In both cases, we performed a parathyroidectomy with the da Vinci robotic system through a left-sided approach. Three thoracoports were inserted around the mammary gland for the robot and a fourth auxiliary port was positioned in between. Single-lung ventilation was installed, and the mediastinum was entered by opening the parietal pleura along the left phrenic nerve. The upper margin for dissection was the left brachiocephalic vein that was followed until the right pleura. All the tissue in front of the pericardium was dissected en bloc. The sinking test of the nodule and a preoperative frozen section analysis confirmed the diagnosis of parathyroid adenoma, which was also proven by rapid parathyroid hormone analysis. The resection of a parathyroid adenoma from the aortopulmonary window represents an ideal case for robotic surgery.     

Functional and anatomical variability of canine cardiac sympathetic efferent pathways: implications for regional denervation of the left ventricle

To further elucidate the functional anatomy of canine cardiac innervation as well as to assess the feasibility of producing regional left ventricular sympathetic denervation, the chronotropic and (or) regional left ventricular inotropic responses produced by stellate or middle cervical ganglion stimulation were investigated in 22 dogs before and after sectioning of individual major cardiopulmonary or cardiac nerves. Sectioning the right or left subclavian ansae abolished all cardiac responses produced by ipsilateral stellate ganglion stimulation. Sectioning a major sympathetic cardiopulmonary nerve, other than the right interganglionic nerve, usually reduced, but seldom abolished, regional inotropic responses elicited by ipsilateral middle cervical ganglion stimulation. Sectioning the dorsal mediastinal cardiac nerves consistently abolished the left ventricular inotropic responses elicited by right middle cervical ganglion stimulation but minimally affected those elicited by left middle cervical ganglion stimulation. In contrast, cutting the left lateral cardiac nerve decreased the inotropic responses in lateral and posterior left ventricular segments elicited by left middle cervical ganglion stimulation but had little effect on the inotropic responses produced by right middle cervical ganglion stimulation. In addition, the ventral mediastinal cardiac nerve was found to be a significant sympathetic efferent pathway from the left-sided ganglia to the left ventricle. These results indicate that the stellate ganglia project axons to the heart via the subclavian ansae and thus effective sympathetic decentralization can be produced by cutting the subclavian ansae; the right-sided cardiac sympathetic efferent innervation of the left ventricle converges intrapericardially in the dorsal mediastinal cardiac nerves; and the left-sided cardiac sympathetic efferent innervation of the left ventricle diverges to innervate the left ventricle by a number of nerves including the dorsal mediastinal, ventral mediastinal, and left lateral cardiac nerves. Thus consistent denervation of a region of the left ventricle can not be accomplished by sectioning an individual cardiopulmonary or cardiac nerve because of the functional and anatomical variability of the neural components in each nerve, as well as the fact that overlapping regions of the left ventricle are innervated by these different nerves.     

Complete Thymectomy in Adult Rats with Non-invasive Endotracheal Intubation

Thymectomy in neonatal rodents is an established and reliable procedure for immunological studies. However, in adult rats, complications of hemorrhage and pneumothorax from pleural disruption can result in a significant mortality rate. This protocol is a simple method of rat thymectomy that utilizes a mini-sternotomy and endotracheal intubation. Intubation is accomplished with a non-invasive and easily reproducible method and allows for positive pressure ventilation to prevent pneumothorax and a controlled airway that allows sufficient time for careful thymus dissection to minimize pleural disruption. A 1.5 cm sternal incision decreases contact with mediastinal vessels and pleura, while still providing full visualization of the thymus. Following exposure of the mediastinum, the thymus is removed by blunt dissection under magnification. The pleural space is then sealed by suture closure of the pre-tracheal muscles followed by the application of surgical glue. The thorax is then closed by suture closure of the sternum, followed by suture closure of the skin. All thymectomies were complete as evidenced by immunohistochemical (IHC) staining of mediastinal tissue, and absence of naïve T-cells by flow cytometry, and the procedure had a 96% survival rate. This method is suitable when complete thymectomy with minimal complications is desired for further immunological studies in athymic adult rats.     

Image processing of thymus tumors]

Altogether 40 thymic tumor patients were investigated. Radiograms and pneumomediastinograms were subjected to processing aposteriori (increased contrast and spatial filtration). Spatial filtration improved selective analysis of spatial frequencies of imaging. Processing of images specified diagnosis of thymomas by underlining the shapes of normal and abnormal mediastinal formations and signs of invasion of the pericardium and pleura.     

Effects of SNP, ouabain, and amiloride on electrical potential profile of isolated sheep pleura.

The fluid and solute transport properties of pleural tissue were studied by using specimens of intact visceral and parietal pleura from adult sheep lungs. The samples were transferred to the laboratory in a Krebs-Ringer solution at 4 degrees C within 1 h from the death of the animal. The pleura was then mounted as a planar sheet in a Ussing-type chamber. The results that are presented in this study are the means of six different experiments. The spontaneous potential difference and the inhibitory effects of sodium nitroprusside (SNP), ouabain, and amiloride on transepithelial electrical resistance (R(TE)) were measured. The spontaneous potential difference across parietal pleura was 0.5 +/- 0.1 mV, whereas that across visceral pleura was 0.4 +/- 0.1 mV. R(TE) of both pleura was very low: 22.02 +/- 4.1 Omega. cm2 for visceral pleura and 22.02 +/- 3.5 Omega. cm2 for parietal pleura. There was an increase in the R(TE) when SNP was added to the serosal bathing solution of parietal pleura and to the serosal or mucosal bathing solution in visceral pleura. The same was observed when ouabain was added to the mucosal surface of visceral pleura and to either the mucosal or serosal surface of parietal pleura. Furthermore, there was an increase in R(TE) when amiloride was added to the serosal bathing solution of parietal pleura. Consequently, the sheep pleura appears to play a role in the fluid and solute transport between the pleural capillaries and the pleural space. There results suggest that there is a Na+ and K+ transport across both the visceral and parietal pleura.     

Pathology of radiation induced heart disease

The aim of this paper is dual — to review the relevant literature on pathology of radiation induced heart disease (RIHD), and to present an illustrative case of our own. Therapeutic ionizing radiation, such as that used in the treatment of Hodgkin´s lymphoma and cancers of left breast, lungs, esophagus, and thymus, can cause cardiac damage that may take several years to manifest.The spectrum of RIHD is broad and includes [1] pericarditis and pericardial effusion; [2] endocardial fibrosis and valvular dysfunction; [3] nonischemic myocardial fibrosis; [4] obstructive coronary artery disease with resultant myocardial ischemia; [5] damage to the great vessels; and [6] conduction system dysfunction. Pericardial disease, however, is the most common manifestation of mediastinal irradiation. A case is described of a typical RIHD in a 52-year-old female who died from heart failure with a history of mediastinal neuroblastoma operated and irradiated at the age of 9 years. Her autopsy heart lesions comprised chronic and acute pericarditis with constrictive features, myocardial fibrosis with features of restrictive cardiomyopathy and fibrosis with calcification of the left heart valves. As a unique lesion, there were small calcifications in the mural endocardium and in the large arterial intima. This finding seems to be diagnostic for RIHD.     

Functional anatomy of the canine mediastinal cardiac nerves located at the base of the heart

The major canine cardiopulmonary nerves which arise from the middle cervical and stellate ganglia and the vagi course toward the heart in the dorsal mediastinum where they form, at the base of the heart dorsal to the pulmonary artery and aorta, the dorsal mediastinal cardiac nerves. In addition, the left caudal pole and interganglionic nerves project onto the left lateral side of the heart as the left lateral cardiac nerve. These nerves contain afferent and (or) efferent axons which, upon stimulation, modify specific cardiac regions and (or) systemic pressure. In addition, with the exception of the left lateral cardiac nerve, stimulation of each of these nerves produces compound action potentials in the cranial ends of the majority of the major cardiopulmonary nerves demonstrating that axons in each dorsal mediastinal cardiac nerve interconnect with axons in the majority of the cardiopulmonary nerves. Axons in the left lateral cardiac nerve connect primarily with axons in the left caudal pole and left interganglionic nerves. The dorsal mediastinal nerves project distally onto the heart as coronary nerves accompanying the right or left coronary arteries. These innervated the ventricular myocardium which is supplied by their respective vessels. The left lateral cardiac nerve projects directly onto the lateral epicardium of the left ventricle. The dorsal mediastinal and left lateral cardiac nerves are the major sympathetic cardiac nerves. Thus, the cardiac nerves located in the mediastinum at the base of the heart are not simple extensions of cardiopulmonary nerves, but rather have a unique anatomy and function of their own.     

Pulmonary ischemia induces lung remodeling and angiogenesis.

Cellular remodeling during angiogenesis in the lung is poorly described. Furthermore, it is the systemic vasculature of the lung and surrounding the lung that is proangiogenic when the pulmonary circulation becomes impaired. In a mouse model of chronic pulmonary thromboembolism, after left pulmonary artery ligation (LPAL), the intercostal vasculature, in proximity to the ischemic lung, proliferates and invades the lung (12). In the present study, we performed a detailed investigation of the kinetics of remodeling using histological sections of the left lung of C57Bl/6J mice after LPAL (4 h to 20 days) or after sham surgery. New vessels were seen within the thickened visceral pleura 4 days after LPAL predominantly in the upper portion of the left lung. Connections between new vessels within the pleura and pulmonary capillaries were clearly discerned by 7 days after LPAL. The visceral pleura and the lung parenchyma showed intense tissue remodeling, as evidenced by markedly elevated levels of both proliferating cell nuclear antigen and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling positive cells. Rapidly dividing cells were predominantly macrophages and type II pneumocytes. The increased apoptotic activity was further quantified by caspase-3 activity, which showed a sixfold increase relative to naive lungs, by 24 h after LPAL. Because sham surgeries had little effect on measured parameters, we conclude that both thoracic wound healing and pulmonary ischemia are required for systemic neovascularization.     

Mechanics of the canine diaphragm in pleural effusion

Pleural effusion is a complicating feature of many diseases of the lung and pleura, but its effects on the mechanics of the diaphragm have not been assessed. In the present study, radiopaque markers were attached along muscle bundles in the midcostal region of the diaphragm in anesthetized dogs, and the three-dimensional location of the markers during relaxation before and after the stepwise introduction of liquid into the left or right pleural space and during phrenic nerve stimulation in the same conditions was determined using computed tomography. From these data, accurate measurements of diaphragm muscle length and displacement were obtained, and the changes in pleural and abdominal pressure were analyzed as functions of these parameters. The effect of liquid instillation on the axial position of rib 5 was also measured. The data showed that 1) liquid leaked through the dorsal mediastinal sheet behind the pericardium so that effusion was bilateral; 2) effusion caused a caudal displacement of the relaxed diaphragm; 3) this displacement was, compared with passive lung inflation, much larger than the cranial displacement of the ribs; and 4) the capacity of the diaphragm to generate pressure, in particular pleural pressure, decreased markedly as effusion increased, and this decrease was well explained by the decrease in active muscle length. It is concluded that pleural effusion has a major adverse effect on the pressure-generating capacity of the diaphragm and that this is the result of the action of hydrostatic forces on the muscle.     

Peripheral carcinoma of the lung in magnetic resonance imaging

This study shows magnetic resonance imaging (MRI) to be a technique in the comprehensive diagnosis of peripheral carcinoma of the lung and in the determination of the extent of a tumor process in the chest. The paper specifies and systematizes the MRI signs of peripheral carcinoma of the lung, the signs of tumor invasion into the pleura, chest, and mediastinal structures. It also analyzes additional capacities of contrast enhancement.     

Effect of acute lymphatic obstruction on fluid accumulation in the chest in dogs.

The effect of acute obstruction to lymphatic drainage on fluid accumulation in the lungs, pleura, and pericardium was assessed in the intact dog. Catheters were positioned in the venae cavase, right atrium (RA), left atrium (LA), age on fluid accumulation in the lungs, pleura, and pericardium was assessed in the intact dog. Catheters were positioned in the venae cavae, right atrium (RA), left atrium (LA), and aorta (Ao) of nine anesthetized, spontaneouly breathing dogs, and hydrostic and colloid osmotic pressures were continuously monitored. Lymphatic obstruction was achieved by raising systemic venous pressure to either 10 mmHg or 25 mmHg by a combination of fluid infusion and inflation of balloon catheters in the venae cavae for 2 h. The same constant net intravascular filtration pressure was maintained in both groups by appropriate use of saline or colloid-containing fluids. Pleural and pericardial fluids were measured postmortem and lung water content was determined by weighing before and after drying. Failure to detect greater fluid accumulation at the higher obstructing pressure (25 mmHg) than at the lower obstructing pressure (10 mmHg) suggests that over the range of obstructing pressures used there is no acute change in the magnitude of lymphatic drainage in the chest.     

Adriamycin (Doxorubicin) Cardiotoxicity: A Review

Adriamycin (doxorubicin hydrochloride) is an antineoplastic agent effective against a wide range of malignant conditions, although cardiac toxicity, especially dose-dependent cardiomyopathy, limits its long-term use. Previous mediastinal radiation therapy or left ventricular dysfunction and advanced age increase the risk of this complication developing. Unfortunately, there is no readily available, noninvasive method that can predict Adriamycin-induced congestive heart failure (CHF). However, both endomyocardial biopsy and radionuclide ejection-fraction measurement are promising techniques which may soon permit selection of patients who can safely receive this drug. At present, Adriamycin-induced CHF can best be prevented by limiting the total dose as follows: 400 to 450 mg per sq meter following mediastinal radiation and 500 to 550 mg per sq meter for patients without other significant risk factors. Consideration of dose-response data and use of a weekly schedule may soon permit the administration of Adriamycin for long-term antineoplasm therapy.     

Procedure for intrapleural implantation in mice by thoracotomy

An intrapleural implantation procedure by thoracotomy was developed for application in mice. Animal survival was found to depend on the following: (A) slow induction and quick reversal of a pneumothorax by controlled pleural air injection and withdrawal, (B) keeping the pleura open for the shortest possible time by quick insertion of the implant and immediate tight closure with prepositioned sutures, and (C) use of the right, not the left, pleural cavity especially for maximum size implants which for a 30-gram mouse was 12 X 5 X 4 mm. Surgical and postsurgical mortality was below 5% (n = over 300).     

Animal models of human anthrax: The Quest for the Holy Grail

Anthrax is rare among humans, few data can be collected from infected individuals and they provide a fragmentary view of the dynamics of infection and human host–pathogen interactions. Therefore, the development of animal models is necessary. Anthrax has the particularity of being a toxi-infection, a combination of infection and toxemia. The ideal animal model would explore these two different facets and mimic human disease as much as possible. In the past decades, the main effort has been focused on modelling of inhalational anthrax and the perception of specific aspects of the infection has evolved in recent years. In this review, we consider criteria which can lead to the most appropriate choice of a given animal species for modelling human anthrax. We will highlight the positive input and limitations of different models and show that they are not mutually exclusive. On the contrary, their contribution to anthrax research can be more rewarding when taken in synergy. We will also present a reappraisal of inhalational anthrax and propose reflections on key points, such as portal of entry, connections between mediastinal lymph nodes, pleura and lymphatic drainage.     

Structural characteristics of the mediastinal pleura and its blood vessels

By means of impregnation of the microcirculatory bed vessels after V. V. Kupriyanov and transmissive electron microscopy, topological picture of hemomicrovessels has been estimated in the glomerular constructions of the dog mediastinal pleura. The composition of cell elements and peculiarities in distribution of the latter in the zone of the milk spots are examined. Their structural characteristics are manifested as presence of mesothelium of a decomplexated type accumulation of macrophagal and lymphocyto-plasma cells, glomerular organization of the capillary network and postcapillary venules, two types of endothelial lining of the metabolic microvessels. The role of the milk spots in ensuring immune protection, in migration of macrophages and in filtration of the pleural liquid is discussed.     

252 例胸膜恶性肿瘤的临床病理分析

目的：探讨胸膜恶性肿瘤的病理类型、肿瘤所占比例、临床病理特征及鉴别诊断。方法：结合病理形态学及免疫组化方法对 252 例胸膜恶性肿瘤进行诊断及鉴别诊断。结果：252 例胸膜恶性肿瘤包括胸膜穿刺活检120 例,胸腔镜活检25 例,伴有胸膜转 移的恶性胸水107 例;男性143 例,女性109 例,年龄19-87 岁,平均年龄59.9 岁。临床主要症状是胸闷、气短、咳嗽、胸痛等。CT 表现为胸膜增厚、胸水(90%)、多发或单发胸膜结节和原发器官占位性病变。活检病例中,转移性癌86 例(34.1%),包括肺腺癌64 例(25.4%),小细胞癌11 例(4.4%),鳞癌11 例(4.4%),恶性间皮瘤47 例(18.7%),滑膜肉瘤9 例(3.6%),非霍奇金淋巴瘤3 例(1.2%); 恶性胸水病例病例中转移性癌95 例(37.7%),包括肺腺癌85 例(33.7%),小细胞癌6 例(2.4%),鳞癌2 例(0.8%),乳腺腺癌2 例 (0.8%),恶性间皮瘤8 例(3.2%),非霍奇金淋巴瘤4 例(1.6%)。结论：胸膜恶性肿瘤中以转移性腺癌多见,其次为恶性间皮瘤,结合 形态学及免疫组织化学检测不同标志物的表达有助于诊断胸膜恶性肿瘤的种类。     

Cytologic features of solitary fibrous tumor of the parotid gland. A case report

BACKGROUND: Solitary fibrous tumor (SFT) is a rare neoplasm that most commonly involves the pleura but is increasingly recognized at other locations, including lung, liver, thyroid and parotid glands, with only a few reports describing its cytologic features. CASE: The fine needle aspiration biopsy (FNAB) features of an SFT located in the left parotid gland of a 34-year-old woman were compared to the histologic and immunohistochemical aspects of the lesion. CONCLUSION: This case confirms that SFT has distinct cytomorphologic features and that FNAB can be helpful in its diagnosis.     

252例胸膜恶性肿瘤的临床病理分析

目的：探讨胸膜恶性肿瘤的病理类型、肿瘤所占比例、临床病理特征及鉴别诊断。方法：结合病理形态学及免疫组化方法对252例胸膜恶性肿瘤进行诊断及鉴别诊断。结果：252例胸膜恶性肿瘤包括胸膜穿刺活检120例,胸腔镜活检25例,伴有胸膜转移的恶性胸水107例;男性143例,女性109例,年龄19—87岁,平均年龄59．9岁。临床主要症状是胸闷、气短、咳嗽、胸痛等。CT表现为胸膜增厚、胸水（90％）、多发或单发胸膜结节和原发器官占位性病变。活检病例中,转移性癌86例（34．1％）,包括肺腺癌64例（25．4％）,小细胞癌11例（4．4％）,鳞癌11例（4．4％）,恶性间皮瘤47例（18．7％）,滑膜肉瘤9例（3．6％）,非霍奇金淋巴瘤3例（1．2％）;恶性胸水病例病例中转移性癌95例（37．7％）,包括肺腺癌85例（33．7％）,小细胞癌6例（2．4％）,鳞癌2例（0．8％）,乳腺腺癌2例（0．8％）,恶性间皮瘤8例（3．2％）,非霍奇金淋巴瘤4例（1．6％）。结论：胸膜恶性肿瘤中以转移性腺癌多见,其次为恶性间皮瘤,结合形态学及免疫组织化学检测不同标志物的表达有助于诊断胸膜恶性肿瘤的种类。     

Receptive properties of primary afferent fibres from rabbit pleura,in vitro

Abstract We investigated the physiological properties of mediastinal pleural primary afferent units by recording single nerve fibre activity from the phrenic nerve in an in vitro preparation of rabbit tissue. A total of 41 units with conduction velocities in the group III and IV range were examined for their responsiveness to mechanical, thermal and chemical stimuli. Most receptive fields were adjacent to the phrenic nerve-pericardiacophrenic artery complex. The thresholds to punctate mechanical stimulation (von Frey hairs) were widely scattered around a median of 5.4 mN; all fibres showed slowly adapting responses to mechanical stimulation. Heat sensitivity was observed in 7/41 units (17%), while 17/41 (41%) of the fibres exhibited a spurious transient excitation to strong and rapid cooling. Chemosensitivity was scarce with respect to capsaicin (7/33 (21%) of the units responding) but more common to CO2-saturated synthetic interstitial fluid (pH 6.1, 5/16 (31%) responding). The most effective stimulus was a mixture of bradykinin, serotonin, histamine and prostaglandin E2 ('inflammmatory soup') which evoked stimulus responses in 27/33 (82%) of the afferent fibres challenged. Sensitization to mechanical stimuli occurred in 5/41 (12%) of the units, following the application of heat or inflammatory mediators. The rabbit pleura appears as a tissue mainly innervated by multimodal mechano- and chemosensitive afferent units.