The connective tissue of the rat lung: electron immunohistochemical studies

The ultrastructural distribution of specific connective-tissue components in the normal rat lung was studied by electron immunohistochemistry. Three of these components were localized: type I collagen, fibronectin and laminin. Type I collagen was present not only in major airways and vascular structures, but also in alveolar septa. Laminin was found in all basement membranes, and only in basement membranes, demonstrating once more that this glycoprotein is an intrinsic component of the basement membrane. Fibronectin was found free in the interstitium and on the surfaces of collagen fibers. The basement membranes of bronchial, glandular and endothelial cells of large vessels lacked fibronectin; however, capillary endothelial and occasionally epithelial alveolar basement membranes contained some fibronectin in an irregular, spotty distribution. This localization suggests that in the lung, as in other tissues, fibronectin is not an intrinsic component of the basement membrane, but rather a stromal and plasma protein. Only basement membranes in the alveolar parenchyma contained "trapped" plasma fibronectin.     

The theory of case-control studies for early detection programs

Although case-control studies are widely used for evaluating the benefit of early detection programs, the theoretical basis underlying this application has not been well developed. In this paper the properties of chronic disease case-control studies for evaluating early detection programs are investigated. An idealized case-control study is analyzed and the theoretical expression for the odds ratio associated with the benefit of screening is derived. The odds ratio is related to the natural history of disease and the screening program. Our results indicate that case-control studies result in odds ratios that are surprisingly close to unity and consequently have low power.     

Effect of early decrease in the lesion size on late brain tissue loss, synaptophysin expression and functionality after a focal brain lesion in rats

The purpose of the present study is to determine the effects of early decrease in the lesion size on late brain tissue loss, synaptogenesis and functionality after a focal brain lesion in rats. The lesion was induced either to the cortex using the photothrombotic ischemic stroke or to the striatum using the malonate poisoning model. The cortical and striatal lesions amounted to 66-80 mm(3) at day 1 post-lesion and were reduced by 50% after the acute administration of dipyridyl (a liposoluble iron chelator) and aminoguanidine (an inhibitor of the inducible nitric oxide synthase), respectively. Loss of histologically intact tissue and synaptophysin expression as an indicator of synaptogenesis were examined at day 35 post-lesion. Both types of lesion resulted in synaptophysin upregulation in contralateral and ipsilateral cortical areas. On the contrary, brain tissue loss was greater after the striatal (-17%) than the cortical lesion (-5%). Synaptophysin expression and tissue loss were not different between drug- and vehicle-treated rats. Moreover, a set of standard neurological tests revealed a difference in deficit between the both types of lesion, yet only in the acute post-lesion stage. However, it did not distinguish between vehicle- and drug-treated rats whatever the lesion location. Our results indicate that late histological endpoints measurements are not recommended to probe the potential neuroprotective properties of a drug administered within the acute post-lesion stage. They also suggest that inhibition of cytotoxic mechanisms involved in lesion growth is of no clinical interest when it cannot lead to a long-term histological protection and/or increased synaptogenesis.     

Radiation cell survival and growth delay studies in multicellular spheroids of small-cell lung carcinoma

The radiation sensitivity of two small-cell lung carcinoma cell lines growing as multicellular spheroids in static culture was determined using clonogenic cell survival and growth delay as endpoints. Growth delay determination suggested that clonogenic cell kill was less than was obtained by direct assay of cell survival. Recovery from potentially lethal damage was assayed in one line (HC12) but was not demonstrable, and clonogenic cell survival decreased with time in treated spheroids with diameters greater than 300 microns which contained a hypoxic cell population. Microscopic examination of the treated spheroids showed the emergence of an abnormal giant-cell population, and the progressive clonogenic cell loss that occurred after treatment was thought to be due to oxygen and nutrient deprivation of the remaining viable cells by this doomed cell population. Correction of the growth delay measurements for changes in cell size and clonogenic cell population allowed correlation of the growth delay and cell survival data.     

Subacute sclerosing panencephalitis: detection of measles virus RNA in appendix lymphoid tissue before clinical signs.

An appendix removed 15 days before onset of symptoms of subacute sclerosing panencephalitis was examined retrospectively for measles virus ribonucleic acid (RNA). Tissue sections hybridised in situ to a cloned measles virus probe of deoxyribonucleic acid specific for nucleocapsid protein showed that many cells of the lymphoid tissue contained measles virus RNA. In contrast, only a few infected lymphoid cells were detected in three out of six seropositive controls and none in three seronegative infants. A widespread chronic viral infection of the immune system, established after measles, may promote or even initiate nerve cell infection in subacute sclerosing panencephalitis.     

肿瘤自身抗体检测对早期肺癌的诊断价值

目的探讨肺癌自身抗体P53、PGP9.5、SOX2、GAGE7、GBU4-5、MAGEA1和CAGE对早期肺癌的诊断价值。方法采用ELISA法检测肺癌组(46例首次确诊的肺癌患者)和对照组(包含22名肺部良性疾病患者及23例健康体检者)血清中肺癌自身抗体P53、PGP9.5、SOX2、GAGE7、GBU4-5、MAGEA1和CAGE表达水平,分析评价7种肺癌自身抗体单独检测和联合检测对肺癌的临床诊断价值。结果肺癌组患者血清中7种自身抗体的水平明显高于对照组(均P<0.05)。肺癌组患者7种抗体联合检测的阳性率明显高于对照组(65.22%vs 15.56%,χ²=23.252,P<0.001)。单一肺癌自身抗体检测的敏感性为4.35%~36.96%,特异性为93.30%~100.00%,AUC为0.695~0.832。7种肺癌抗体联合检测的敏感性为65.22%,特异性为84.44%,AUC为0.897。结论早期肺癌患者血清中7种肺癌自身抗体水平均较高。单一肺癌自身抗体检测的特异性较高,但敏感性较低。7种肺癌自身抗体联合检测具有较高的敏感性,可成为临床早期肺癌新的辅助诊断指标。     

Identification of pathological subtypes of early lung adenocarcinoma based on artificial intelligence parameters and CT signs

Objective: To explore the value of quantitative parameters of artificial intelligence (AI) and computed tomography (CT) signs in identifying pathological subtypes of lung adenocarcinoma appearing as ground-glass nodules (GGNs). Methods: CT images of 224 GGNs from 210 individuals were collected retrospectively and classified into atypical adenomatous hyperplasia (AAH)/adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (IAC) groups. AI was used to identify GGNs and to obtain quantitative parameters, and CT signs were recognized manually. The mixed predictive model based on logistic multivariate regression was built and evaluated. Results: Of the 224 GGNs, 55, 93, and 76 were AAH/AIS, MIA, and IAC, respectively. In terms of AI parameters, from AAH/AIS to MIA, and IAC, there was a gradual increase in two-dimensional mean diameter, three-dimensional mean diameter, mean CT value, maximum CT value, and volume of GGNs (all P<0.0001). Except for the CT signs of the location, and the tumor–lung interface, there were significant differences among the three groups in the density, shape, vacuolar signs, air bronchogram, lobulation, spiculation, pleural indentation, and vascular convergence signs (all P<0.05). The areas under the curve (AUC) of predictive model 1 for identifying the AAH/AIS and MIA and model 2 for identifying MIA and IAC were 0.779 and 0.918, respectively, which were greater than the quantitative parameters independently (all P<0.05). Conclusion: AI parameters are valuable for identifying subtypes of early lung adenocarcinoma and have improved diagnostic efficacy when combined with CT signs.     

Shunt in the diagnosis of initial lung lesion in smokers

Cigarette smoking is an important risk factor for all respiratory tract diseases. Unfortunately, the symptoms develop slowly, thus patients feel the consequences of the slowly developing inflammation too late. The inflammation first develops in the area of respiratory bronchioles. In this stage, the disease is asymptomatic. The study included a sample of 31 smokers, mean age 36.38 years, with normal spirometry indices, acid-base status and arterial blood gases. The mean smoking index was 11.28 smoking/years. All subjects were healthy, without any subjective health problems or disease indicators. The aim was to define dead lung area (V/Q) as an early indicator of changes in smokers. Study results demonstrated the mean shunt value in smokers of 8.25%, which showed positive correlation with smoking. The shunt size yielded negative correlation with the forced expiratory volume in one second and midexpiratory flow in smokers. In conclusion, determination of lung shunt is a simple method that is sensitive enough in the diagnosis of initial lung lesion due to cigarette smoking.     

The x-ray morphological characteristics of the early manifestations of sarcoidosis

The paper is devoted to an analysis of combined x-ray findings supplemented by CT findings in patients with sarcoidosis detected for the first time with early signs of this disease. A conclusion has been made that apart from lymph node enlargement, sarcoidosis is characterized by lung parenchymal changes which manifest themselves as symptoms of broncho-alveolitis. Characteristic x-ray symptom complexes are described. Roentgeno-semiotics of these changes were compared with the results of morphological investigation of transbronchial puncture specimens. Roentgenologically detectable changes showed good correlation with morphology findings. The authors have also emphasized the importance of morphological verification of this disease at early stages.     

Mycobacterium tuberculosis DNA in tissue affected by sarcoidosis.

OBJECTIVE--To investigate the prevalence of Mycobacterium tuberculosis DNA in granulomatous tissues from patients with sarcoidosis and from controls matched for age, sex, and tissue by using the polymerase chain reaction. DESIGN--Single blind control trial. SUBJECTS--16 patients with sarcoidosis who had undergone diagnostic biopsy of lung, skin, or lymph node and 16 patients with squamous cell carcinoma or Hodgkin''s disease to act as controls. In addition, four lung specimens infected with M tuberculosis were included as positive controls. RESULTS--M tuberculosis DNA was present in sarcoid tissues containing granulomas from seven of the 16 patients and one of the 16 matched controls. Two of the four specimens known to be infected with M tuberculosis were positive in the controlled experiment. CONCLUSION--These figures suggest that M tuberculosis DNA is detected as readily in patients with sarcoidosis as in patients with frankly tuberculous tissues and imply that M tuberculosis may be linked to the cause of sarcoidosis.