Effect of adrenaline on transmesothelial resistance of isolated sheep pleura

The effect of adrenaline on the transmesothelial resistance (RTM) of sheep's visceral and parietal pleura was studied using the Ussing chamber technique. Basal transmesothelial resistance of visceral pleura was found to be 20.71 +/- 0.31 Omega cm2, whereas that of parietal pleura was found to be 19.53 +/- 0.34 Omega cm2. Immediately after the addition of adrenaline (10(-7) M) both apically and basolaterally on the visceral and parietal pleura, these values were significantly increased (P < 0.05). Addition of the nonselective beta-receptor blocker, propranolol (10(-5) M), suppressed this effect in both visceral and parietal pleura, while addition of the nonselective alpha-receptor blocker, phentolamine (10(-5) M), partly suppressed the above-mentioned increase in the parietal pleura. In conclusion, our results show that adrenaline has a rapid effect on both pleurae. This rapid effect is mediated by the stimulation of beta-adrenergic receptors in the case of visceral pleura, while in the case of parietal pleura this effect seems to be due to a stimulation of alpha- and beta-adrenergic receptors. On the visceral pleura the effect of adrenaline vanishes after some minutes and on the parietal this effect is more permanent than the visceral's one, suggesting differences in the distribution of the adrenergic receptors between the visceral and parietal pleura.     

The clinical significance of and the factors associated with macrolide resistance and poor macrolide response in pediatric Mycoplasma pneumoniae infection: A retrospective study

BackgroundMacrolide-resistant Mycoplasma pneumoniae (MRMP) infection is increasing worldwide. However, its clinical significance is still uncertain.MethodsThe data of the Laboratory Medicine Department of Chang Gung Memorial Hospital in northern Taiwan was searched for children with molecular confirmed macrolide-susceptible Mycoplasma pneumoniae (MSMP) and MRMP infections between January 2011 and December 2018. The clinical features, laboratory data, and chest image presentations were compared between patients with MRMP and MSMP infections and between patients with good and poor macrolide response, respectively.ResultsRecords from 158 patients were recovered. Of the enrolled patients 34 (22%) suffered MRMP infection, 27 (17%) had pleural effusions, and 47 (32%) had poor macrolide response. The macrolide resistance rate was 12% in 2011, 20% between 2015 and 2016, and 50% between 2017 and 2018, respectively. Other than a poor macrolide response, the MRMP and MSMP infections are clinically indistinguishable. The presence of pleural effusion and MRMP infections were found to be independently associated with a poor macrolide response, with odds ratios (95% confidence interval) of 14.3 (4.9–42.0) and 14.6 (5.4–40), respectively. The macrolide resistance rate of the patients with a poor macrolide response was 49% and 18% among all the patients enrolled and the patients with a pleural effusion, respectively.ConclusionThe macrolide resistance rate had possibly increased in recent years in Taiwan and should be continuously monitored. In addition, the macrolide response could be misleading in predicting a macrolide resistance especially for the patients with a pleural effusion.     

Primary “adenosquamous” mesothelioma of the pleura

Summary The case of a 64-year-old man with adenosquamous mesothelioma of the pleura is described. These two elements were intimately associated, which suggested that they formed an integral part of the tumor. To the authors, pluripotentiality of the mesothelium seems essential for the pathogenesis of this unusual neoplasm.     

Nodular hemangiomatosis of pleura and peritoneum

Multiple, simultaneously occurring hemangiomas in one or more organs are known as hemangiomatosis syndromes in the context of phacomatosis manifesting in childhood. Nevertheless, hemangiomas of the serous membranes are extremely rare and often present as solitary lesions. We report the case of an elderly patient who suffered from diffuse hemangiomatosis of the visceral peritoneum and pleura and deceased due to acute respiratory distress syndrome following persistent and unmanageable pulmonary hemorrhage. We present an unusual case of a disseminated but histologically benign appearing hemangiomatosis of the serous membranes.     

Malignant mesothelioma of the pleura

Summary Between March 1981 and February 1985, 93 out of 132 patients with a histologically confirmed diagnosis of malignant pleural mesothelioma were eligible for therapy and were prospectively assigned to receive either combined therapy or best supportive care, according to their personal preferences. Fifty-seven patients underwent multimodal therapy including surgical resection where possible, polychemotherapy, and radiation therapy in case of partial remission. Thirty-six patients received maximal supportive care only, as did 39 patients who were not eligible for treatment. The median survival was 13 months for treated patients compared to 7 for those receiving best supportive care and 5 for patients not amenable to treatment. Median progress-free survival was 6, 2, and 1 month respectively. Surgical resection did not prolong life expectancy within the treated group. In view of significant differences in the distribution of various cofactors over the two study groups, stepwise Cox model analyses were performed. Prognostic nontreatment variables related to prolonged survival were: good performance status, stage I and II, absence of chest pain, age below 50 years, and epithelial histology. Although in the Cox model analyses the survival improvement of patients being treated could be greatly attributed to other cofactors, multimodal treatment showed some prolongation of life expectancy.     

Reactive mesothelial cell and mesothelioma of the pleura

Summary The results of a light and electron microscopic study and enzyme histochemistry of reactive mesothelial cells and diffuse and localized (solitary) pleural mesotheliomas were compared, in order to establish a diagnosis and elucidate the cell of origin of the mesotheliomas. The reactive mesothelial cells were usually regular in appearance but could be cuboidal or columnar, or even peg-shaped with large nuclei and prominent nucleoli. Colloidal iron and alcian blue staining were positive in the plasma membrane, microvilli and in parts of the cytoplasm of mesothelial cells. These stains were mostly negative following testicular hyaluronidase treatment. The neoplastic cells of diffuse pleural mesothelioma had some epithelial characteristics such as microvilli, desmosomes, and a prominent basement membrane and were similar to reactive mesothelial cells with regard to cellular form and staining for acid mucopolysaccharides. In this study the colloidal iron and PAS stains appeared to be more intense in mesothelioma cells than in reactive mesothelial cells.In enzyme histochemistry, naphthol AS-D acetate esterase and -naphthyl acetate esterase activity were demonstrated strongly in neoplastic cells. The nuclear-cytoplasmic ratio, the numbers of microvilli and mitochondria and the amount of glycogen were greater in the neoplastic cells when studied by electron microscopy. Electron lucent intracytoplasmic fibrils appeared wider and more distinct in mesothelioma cells.Localized mesotheliomas, thought to be an entirely different entity from reactive mesothelial cells, showed little characteristic morphology in light microscopic pictures, few cytoplasmic organelles were seen ultrastructurally.     

Expression of Na+-glucose cotransporter (SGLT1) in visceral and parietal mesothelium of rabbit pleura

Indirect evidence for a solute-coupled liquid absorption from rabbit pleural space indicated that it should be caused by a Na(+)/H(+)-Cl(-)/HCO(3)(-) double exchanger and a Na(+)-glucose cotransporter [Agostoni, E., Zocchi, L., 1998. Mechanical coupling and liquid exchanges in the pleural space. In: Antony, V.B. (Ed.), Clinics in Chest Medicine: Diseases of the Pleura, vol. 19. Saunders, Philadelphia, pp. 241-260]. In this research we tried to obtain molecular evidence for Na(+)-glucose cotransporter (SGLT1) in visceral and parietal mesothelium of rabbit pleura. To this end we performed immunoblot assays on total protein extracts of scraped visceral or parietal mesothelium of rabbits. These showed two bands: one at 72kDa (m.w. of SGLT1), and one at 55kDa (which should also provide Na(+)-glucose cotransport). Both bands disappeared in assays in which SGLT1 antibody was preadsorbed with specific antigen. Molecular evidence for Na(+)/K(+) ATPase (alpha1 subunit) was also provided. Immunoblot assays for SGLT1 on cultured mesothelial cells of rabbit pleura showed a band at 72kDa, and in some cases also at 55kDa, irrespectively of treatment with a differentiating agent. Solute-coupled liquid absorption hinders liquid filtration through parietal mesothelium caused by Starling forces, and favours liquid absorption through visceral mesothelium caused by these forces.     

Na+-glucose cotransporter is also expressed in mesothelium of species with thick visceral pleura

Molecular evidence for Na+-glucose cotransporter (SGLT1) in rabbit pleural mesothelium has been recently provided, confirming earlier functional findings on solute-coupled liquid absorption from rabbit pleural space. In this research we checked whether SGLT1 is also expressed in pleural mesothelium of species with thick visceral pleura, which receives blood from systemic circulation, but drains it into pulmonary veins. To this end immunoblot assays were performed on total protein extract of scraped visceral and parietal mesothelium of lambs and adult sheep, and of a human mesothelial cell line. All of them showed SGLT1 specific bands. Moreover, confocal immunofluorescence images of lamb pleural mesothelium showed that SGLT1 is located in apical membrane. Therefore, a solute-coupled liquid absorption should also occur from pleural space of species with thick visceral pleura. Because of this protein-free liquid entering interstitium between visceral mesothelium and capillaries, inherent Starling forces should be different than hitherto considered, and visceral pleura capillaries could absorb liquid even in these species.     

Effect of amiloride in human and sheep parietal pleura

The fluid and solute transport properties of human parietal pleura were studied and compared with sheep parietal pleura in vitro. The pleura was mounted as a planar sheet between Ussing-type chambers. The results presented are the mean values of nine different experiments. The transepithelial electrical resistance (R(TE)) of both pleurae species was measured before and after the addition of amiloride in both sides of pleura. The R(TE) for human was 25.74 +/- 1.23 Ohm x cm(2), while for the sheep it was 38.18 +/- 0.83 Ohm x cm(2). The addition of amiloride to the serosal bathing solution increased the R(TE) of human pleura to 30.48 +/- 1.01 Ohm x cm(2) and sheep pleura to 40.32 +/- 0.82 Ohm x cm(2), while amiloride had no effect on the basolateral side. From the above, it is strongly suggested that the human pleura seems to be more leaky than sheep pleura. Although the R(TE) was increased in both pleurae, the elevation in human pleura was significantly higher, thus results from experiments in sheep pleura could only partly be extrapolated in human pleura.     

Mechanical behavior of excised canine visceral pleura

A computer-controlled optical electromechanical biaxial test system was employed to study the mechanical response of excised sheets of canine visceral pleura. Three classes of tests were performed: uniform biaxial stretching tests and tests in which the specimen was cyclically stretched along one axis while either the load or dimension was maintained at a prescribed level in the orthogonal direction. The tests were defined completely within the software. Strain was inferred from tracking four particles affixed to the central region of the specimen surface. The visceral pleura was found to behave similarly to other biological soft tissues and required preconditioning to yield repeatable responses. In addition, the visceral pleura appeared to possess in-plane transverse isotropic material symmetry and to exhibit strong in-plane mechanical coupling at lower loads. The data presented herein is sufficient for determination of certain three-dimensional constitutive laws which are essential for further biomechanical analyses of the visceral pleura's role in lung response.     

肝切除术并发胸腔积液的影响因素分析及诊治体会

目的：探讨肝切除术后并发胸腔积液的影响因素及防治方法。方法：回顾分析123例肝切除术后并发胸腔积液35例患者的临床资料。35例胸腔积液患者均予以保肝、营养支持及利尿治疗;对其中10例中等量以上积液者同时采用B超定位下胸腔穿刺引流治疗,3例合并膈下积液者行膈下积液穿刺引流并加强抗感染治疗,3例合并肺部感染者依据药敏加强抗感染及排痰治疗。结果：本组肝切除术后胸腔积液发生率为28．5％（35／123）;其发生与患者术前肝功能、肝切除量、术中肝门阻断时间及术后腹水量有关（P〈0．05）,与患者的性别、年龄无关（P〉0．05）。35例中,治愈34例;另1例治疗过程中出现肝衰,并发多脏器功能衰竭死亡。结论：胸腔积液是肝切除术后的常见并发症。严格掌握肝切除术适应证、控制肝切除范围,加强术前术后保肝治疗,根据积液量和合并症情况选择合适的治疗方案,对于胸腔积液的预防和治疗具有十分重要的意义。     

Influence of the softness of the parietal pleura on respiratory sliding mechanisms

The pleural surfaces of the lung and chest wall slide against each other with low friction. Normal load support can be effected either by a combination of quasi-static fluid pressure and solid-solid contacts of relatively stiff asperities, or by shear-induced hydrodynamic pressures in the pleural fluid layer. To distinguish between these mechanisms, we measured surface topography and spatial distribution of stiffness of rat parietal pleura using atomic force microscopy. The topography of the pleural surface has unevenness at length scales smaller than the thickness of pleural fluid, similar to mesothelial cell diameters. The estimated maximum normal contact pressure that could be borne by asperities of the soft pleura is much less than that required to support a substantial difference between pleural fluid pressure and the pleural surface pressure. These results suggest that during sliding motion, unevenness of the pleural surface is smoothed by local hydrodynamic pressure, preventing any significant contribution of solid-solid contacts.     

Enteropathogenic Escherichia coli decreases the transepithelial electrical resistance of polarized epithelial monolayers.

The mechanisms whereby enteropathogenic Escherichia coli (EPEC) causes diarrhea remain undefined. We found that EPEC caused a decrease in transepithelial electrical resistance across polarized monolayers of Caco-2 and MDCK epithelial cells. This occurred approximately 6 to 10 h after bacterial addition and was reversible if the monolayers were treated with tetracycline or gentamicin. Although significant alterations in host actin occurred beneath adherent EPEC, actin filaments supporting tight junctions were not noticeably affected in the epithelial cells, nor was the distribution of ZO-1, a tight junction protein. Despite the decrease in transepithelial electrical resistance, EPEC did not cause an increase in [3H]inulin penetration across MDCK monolayers. Unlike in the parental strain, mutations in any loci involved in adherence or formation of attaching and effacing lesions were unable to cause a decrease in transepithelial resistance. These data indicate that EPEC causes a decrease in transepithelial electrical resistance by disrupting a transcellular (intracellular) pathway rather than by disrupting intercellular tight junctions (paracellular) and that these disruptions occur only when attaching and effacing lesions are formed.     

胸腹水粘度测定的实验研究

目的 :探讨胸水与腹水粘度测定的可行性及临床意义。方法 :使用锥板式粘度仪 ,对胸腹水进行三种切变率 ( 2 0s- 1 、40s- 1 、80s- 1 )下的粘度进行测定。结果 :胸腹水的成分符合粘度测定的要求 ,即具有非牛顿流体的特性。结论 :胸腹水粘度测定对胸腹水性质的判定及对临床观察治疗有积极意义。