Rapid quantitative measurement of lung tissue phospholipids

A rapid procedure for the separation of phospholipids of lung tissue into acidic and nonacidic fractions by means of diethylaminoethyl cellulose acetate microcolumns is described. The fractions are then resolved into individual phospholipids by thin-layer chromatography and quantified by transmission densitometry.     

Chromium content of normal and pathologically altered lung tissue

Flameless atomic absorption spectrophotometry was used to determine the chromium (Cr) content of samples taken at autopsy from the lungs, bronchi, and regional hilar lymph nodes of 50 randomly selected patients from urban and rural areas; these patients were not known to have been excessively exposed to Cr. On the average, the Cr concentration in the lungs of patients younger than 40 yr of age was approximately 2 μg/g; for patients over 40, the average Cr values were between 5 and 15 μg/g dry wt. The highest values were found in samples from the apex of the lung. The Cr concentration in lung and lymph nodes increased in proportion to age and the degree of anthracosis. Chromium content in the bronchial wall was very low in all cases. Chromium values up to ten times greater as compared to age-matched average values were found in scarred lung tissue, probably caused by a postinflammatory lymph vessel blockade. Slightly elevated Cr values were found in smokers' lungs. Chromium values in tissue from primary lung carcinomas (n=9) were lower than those in neighboring lung tissue. Based on the results of this study the amount of Cr of lung and bronchial tissue does not appear to be associated with the induction of bronchial carcinoma.     

Isometric contraction by fibroblasts and endothelial cells in tissue culture: a quantitative study

We have used an isometric force transducer to study contraction of two types of nonmuscle cells in tissue culture. This method permits the quantitative measurement of contractile force generated by cells of defined type under the influence of external agents while allowing detailed morphological observation. Chick embryo fibroblasts (CEF), which form a contractile network inside a collagen matrix, and human umbilical vein endothelial cells (HUVE), which are located in a monolayer on the surface of the collagen matrix, were studied. CEF and HUVE in 10% FCS produce a substantial tension of 4.5 +/- 0.2 x 10(4) dynes/cm2 and 6.1 x 10(4) dynes/cm2, respectively. Both cell types contract when stimulated with thrombin, generating a force per cell cross-sectional area of approximately 10(5) dynes/cm2, a value approximately an order of magnitude less than smooth muscle. The integrity of the actin cytoskeleton is essential for force generation, as disruption of actin microfilaments with cytochalasin D results in a rapid disappearance of force. Intact microtubules appear to reduce isometric force exerted by CEF, as microtubule-disrupting drugs result in increased tension. Contraction by HUVE precedes a dramatic rearrangement of actin microfilaments from a circumferential ring to stress fibers.     

Radioimmunoassay for tubulin: a quantitative comparison of the tubulin content of different established tissue culture cells and tissues

A quantitative estimate of the cellular tubulin concentration can be obtained by the use of a radioimmunoassay based upon the competition between tubulin in cell extracts and a known amount of radioactively labeled homogeneous tubulin during binding to a limited amount of antitubulin antibodies. This assay shows that a variety of widely used tissue culture cells (mouse L cells, mouse 3T3 cells, chick embryo fibroblasts) have a tubulin content which corresponds to approximately 2.5-3.3% of their total protein. Transformation of mouse 3T3 cells by the DNA virus SV40, and of chick embryo cells by the RNA Rous sarcoma virus, does not change the intracellular tubulin concentration. Transformed cells of brain origin, such as some glia tumor cell lines and some neuroblastoma cell lines, have a much lower tubulin content than does normal brain tissue.The intracellular concentration of tubulin in mouse 3T3 cells is discussed in relation to the number of microtubules detected during interphase by immunofluorescence microscopy. These results are also discussed in view of a mechanism of microtubule elongation in vivo driven by self-assembly.     

The quantitative analysis of nanoplankton: a study of methods

The Filter-Transfer-Freeze (FTP) technique has been comparedto traditional techniques (Utermhl, electronic particle counter,counting chamber, etc.) for ability to give quantitative cell-densityestimates of either natural water samples or Laboratory cultures.The FTF technique was found to be equal or superior to theseother methods for nanoplankton populations. In addition, theFTF technique offers many advantages such as (i) good opticalquality of the sample. (ii) flexibility in preservation andfixation of sample, (iii) convenience of multiple optical modesfor sample analysis and (iv) rapid and easy preparation allowingaccurate analysis of oceanic nanoplankton on board ship.     

Three-dimensional reconstruction and quantitative analysis of rat lung type II cells: a computer-based study

The three-dimensional structure of alveolar epithelial type II cells was imaged using a computer-based system designed for reconstruction and quantitative analysis of serially sectioned specimens. Six type II cells were reconstructed from serial ultrathin sections of lungs from two Sprague Dawley male rats and the results were compared to standard morphometric estimates of type II cell composition from five other Sprague Dawley male rats. A minor portion of the type II cell surface was in contact with the alveolar airspace while most of the cell surface was embedded in the alveolar septal interstitium. The type II cells contained multiple Golgi regions located close to the nucleus. Mitochondria formed a few branching filamentous networks extending throughout the cell. The reconstructed cells appeared to represent a homogeneous population having fractional volumes of intracellular organelles very similar to those found by morphometric techniques. The spatial distribution of secretory organelle volume suggests that the organization of this cell type reflects an ordered progression of secretory particle maturation which is consistent with earlier hypotheses of lamellar body assembly.     

肺部真菌微生物组研究进展

人体微生物组在健康维护与疾病发展过程中发挥着重要作用。最新研究发现,曾经被视为无菌部位的肺部,其微生物构成也非常丰富,不过针对肺微生物组方面的研究仍然处于早期阶段。真菌及相关基因产物作为人体微生物组的重要组成部分,其在肺部或其他疾病发生与防治方面所具有的潜在功能和意义尚不清晰。本文主要对肺部真菌微生物组的研究技术方法、群落结构特征与功能作用等进行综述,分析了该研究领域目前存在的主要不足,并提出了相关研究建议。     

Motile plant cell body: a "bug" within a "cage"

Analysis of the cytoskeleton in morphogenetically active plant cells allows us to propose a unified concept for the structural organization of eukaryotic cells. Their cytoarchitecture is determined by two principal structural complexes: nucleus-microtubule-based cell bodies ("bugs") and plasma-membrane-F-actin-based cell periphery complexes ("cages"). There are dynamic interactions between each of these entities in response to extracellular and intracellular signals. In the case of the cell body, these signals determine its polarization, rotation and migration. Interactions between cell body and cell periphery complexes determine cell growth polarity and morphogenesis throughout the eukaryotic kingdom.     

Innervation of the carotid body. An experimental quantitative study

The innervation of the carotid body in the cat was studied by means of light- and electron-microscopic techniques. Sinus nerve resection, glossopharyngeal resection, bilateral cervical sympathectomy, excisions of two nerves, and injection of 6-hydroxydopamine (6-OH-DA) were performed in different groups of animals. It was found that resection of the sinus nerve produces a rapid phase of degeneration of intralobular fibers and synaptic boutons, followed by a reinnervation with a progressive reappearance of these elements. This reinnervation is retarded by sympathectomy and prevented by 6-OH-DA. It is therefore concluded that reinnervation is due to collateral regeneration of nearby sympathetic fibers. Resection of the sinus nerve produces an increase in the number of argentaffin cells and dense-cored vesicles in the cytoplasm of principal cells. These findings suggest the existence of efferent synaptic contacts between this nerve and principal cells. Part of the intralobular fibers and synaptic boutons degenerate after bilateral sympathectomy demonstrating that sympathetic axons connect synaptically to the principal cells. Sympathetic fibers reach the carotid body, not only from branches of the cervical plexuses but also from fibers running in the adventitia of the common carotid artery, and via glossopharyngeal and sinus nerves. The vagus nerve contributes a few fibers to the parenchymal lobules of the carotid body.     

Carbohydrate-rich tissue components in lung cancer and in normal bronchial tissues: a histochemical study

Synopsis The carbohydrate-rich compounds in bronchopulmonary neoplasms and in non-neoplastic tissue have been characterized histochemically. Glycogen was present in few epidermoid and large-cell carcinomas. Epithelial mucosubstances were produced by adeno-, mucoepidermoid, and large-cell carcinomas. The mucosubstances produced by carcinoma cells had characteristics different from those occurring in normal tissue. The most striking characteristic was the presence of a sialidase-labile compound in certain neoplasms.Hyaluronic acid was present in the stroma of the carcinomas. In a third of the cases studied, chondroitin sulphates were also present. Higher sulphated compounds were observed as well. This stromal reaction was correlated with the occurrence of a round cell reaction, but not with mast cells. This was considered to indicate the production of stromal material and fibres, but it can also explain the high levels of carbohydrate-rich substances in serum and urine in cases where neoplastic tissue itself does not produce such substances. It also agrees with the theory of carbohydrate-rich compounds acting as a barrier preventing immunological reactions against neoplastic cells.     

Cuttlefish camouflage: a quantitative study of patterning

To investigate camouflage design, we compared the responses of two species of cuttlefish ( Sepia officinalis and Sepia pharaonis ) with controlled but naturalistic backgrounds, consisting of mixtures of 1-mm and 9-mm diameter coloured pebbles. Quantitative analysis of image data using methods adapted from functional imaging research found differences in how the two species camouflage themselves. Whereas S. officinalis switches from background resemblance to a disruptive pattern as it moves from a fine to a coarsely patterned background particle, S. pharaonis blends the two types of pattern. We suggest that the differences may arise because S. pharaonis needs to produce camouflage that is effective when viewed over a relatively wide range of distances.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 335–345.