Alveolar epithelial fluid clearance persists in the presence of moderate left atrial hypertension in sheep

Shaker channel mutants, in which the first (R362), second (R365), and fourth (R371) basic residues in the S4 segment have been neutralized, are found to pass potassium currents with voltage-insensitive kinetics when expressed in Xenopus oocytes. Single channel recordings clarify that these channels continue to open and close from -160 to +80 mV with a constant opening probability (Po). Although Po is low ( approximately 0.15) in these mutants, mean open time is voltage independent and similar to that of control Shaker channels. Additionally, these mutant channels retain characteristic Shaker channel selectivity, sensitivity to block by 4-aminopyridine, and are partially blocked by external Ca2+ ions at very negative potentials. Furthermore, mean open time is approximately doubled, in both mutant channels and control Shaker channels, when Rb+ is substituted for K+ as the permeant ion species. Such strong similarities between mutant channels and control Shaker channels suggests that the pore region has not been substantially altered by the S4 charge neutralizations. We conclude that single channel kinetics in these mutants may indicate how Shaker channels would behave in the absence of voltage sensor input. Thus, mean open times appear primarily determined by voltage-insensitive transitions close to the open state rather than by voltage sensor movement, even in control, voltage-sensitive Shaker channels. By contrast, the low and voltage-insensitive Po seen in these mutant channels suggests that important determinants of normal channel opening derive from electrostatic coupling between S4 charges and the pore domain.     

Alveolar liquid clearance is increased by endogenous catecholamines in hemorrhagic shock in rats

The primary objective of this study was to test the hypothesis that hemorrhagic shock would stimulate alveolar liquid clearance by a catecholamine-dependent mechanism. Anesthetized rats were hemorrhaged to a mean arterial pressure of 30 mmHg for 90 min, but they were not resuscitated. Alveolar liquid clearance was measured by the concentration of labeled and unlabeled protein over 2 h in an isosmolar physiological solution of 5% albumin that had been instilled into one lung. Hemorrhaged rats developed a severe metabolic acidosis that was associated with a 5- to 10-fold rise in plasma epinephrine levels. There was a 60% increase in alveolar liquid clearance in the hemorrhaged rats compared with control rats (55 +/- 6 vs. 34 +/- 7%; P < 0.05). Amiloride (10(-4) M) or propranolol (10(-4)M) inhibited the increase in alveolar liquid clearance. Thus the endogenous release of catecholamines associated with hemorrhagic shock markedly stimulates alveolar fluid clearance by a beta-adrenergic-mediated stimulation of active sodium transport. These data suggest a new, previously unrecognized mechanism that may protect against alveolar flooding in the acute phase of hemorrhagic shock.     

Alveolar lining fluid regulates mononuclear phagocyte 5-lipoxygenase metabolism

The lung clearance of technetium-99m diethylenetriamine penta-acetic acid (99mTc-DTPA) is a measure of respiratory epithelial permeability. Many factors may contribute to the wide range of normal values, including the method of correction for background activity. The aim of this study was to compare three methods of analysis, including their repeatability. 99mTc-DTPA lung clearance imaging was performed on eight nonsmokers (age 32+/-2 yrs, forced expiratory volume in one second (FEV1) 102.8+/-3.3% predicted yrs, mean+/-SEM and seven smokers (age 46+/-4 yrs, p<0.01, versus nonsmokers; FEV1 88.9+/-8.9%, p<0.05 versus nonsmokers) on two occasions each. The smokers were asked to refrain from smoking for 12 h. An uncorrected analysis was compared with two methods corrected for recirculating background activity using an intravenous correction and inter-renal and shoulder background regions of interest. The uncorrected method gave higher mean values for 50% lung clearance of 99mTc-DTPA (t50) values than the inter-renal (p<0.001) and shoulder (p<0.001) methods of correction in nonsmokers and the inter-renal method gave lower values than the shoulder-corrected method (p<0.05). In smokers there was no difference. There were no differences in mean t50 values obtained on two separate visits. There was no difference in the repeatability of the three methods of analysis. The three methods of analysis produced comparable results with no differences in repeatability.     

Alveolar epithelial fluid transport: basic mechanisms and clinical relevance

New evidence indicates that alveolar fluid clearance is driven by active sodium transport across the alveolar epithelium. Several in vivo as well as some in vitro studies indicate that vectorial sodium transport drives fluid clearance across the alveolar epithelium. This transport process can be upregulated by both catecholamine-dependent and catecholamine-independent mechanisms. Water transport appears to move across the alveolar epithelium primarily via transcellular water channels, recently termed aquaporins. Under some conditions, net alveolar fluid clearance continues even in the presence of acute lung injury. It is now possible to study the rate and mechanisms of alveolar fluid clearance in patients with either hydrostatic or increased permeability pulmonary edema. In addition, it may be possible to increase the rate of alveolar fluid clearance and hence the resolution of pulmonary edema in some patients, using aerosolized beta-adrenergic agonist therapy.     

A clinicopathologic study of the resected cases of adenosquamous carcinoma of the lung

Low-grade malignant tumors (LGMT) of the lung were surgically treated in our institute between 1981 and 1997. Both the characteristics and prognosis were examined. We studied 10 cases with LGMT of the lung, male to female ratio 1:1, age range 15 to 71 years, mean 55 years, 6 central and 4 peripheral. Five patients had lobectomy, 3 had sleeve lobectomy and 2 had bilobectomy. Pathologically, 5 samples were typical carcinoid, 3 were mucoepidermoid carcinoma and 2 were adenoid cystic carcinoma. None of the patients had lymph node metastasis. Nine patients were stage I and one stage IIIA. Seven patients underwent absolutely curative resection; 2, relatively non-curative resection; 1, non-curative resection. In preoperative examination, only 4 patients was diagnosed correctly and the others were misdiagnosed. Mean survival time was 167.5 months. One patient died from causes other than the primary cancer and the others are surviving (range 2-173 months). The LGMT group was significantly younger and had a significantly better prognosis compared with the control group (p=0.02). Mediastinal lymph node dissection is suggested to be omitted. However, further accumulation of cases is necessary regarding to the omission of lymph node dissection.     

Alveolar adenoma of the lung: further characterization of this uncommon tumour

Alveolar adenoma of the lung is a poorly characterized, uncommon pulmonary lesion with proliferation of alveolar epithelium and septal mesenchyme. We describe the electron microscopy, immunohistochemistry and DNA flow cytometry in a case of alveolar adenoma in a 55-year-old woman. Alveolar adenoma appears to be a distinct benign neoplasm of the alveolar structures. Our findings further suggest that it is not a precursor of bronchioloalveolar carcinoma or other type II pneumocyte lesions of presumed malignant potential.     

CT-image analysis of resected peripheral adenocarcinomas of the lung less than 1 cm in diameter

Conventional CT (10-mm thick) and helical thin-section CT (2-mm thick) high-resolution images were obtained to study the relationship between the appearance of small peripheral adenocarcinomas of the lung and pathological findings. Eleven cases in which adenocarcinomas less than 1.0 cm in diameter were resected were retrospectively reviewed. Conventional CT images revealed air spaces within pulmonary nodules in 82% of tumors, an ill-defined margin in 91%, and involvement of vessels in 91%. When these findings are observed in pulmonary nodules, thin-section CT should be used for further examination. Helical thin-section CT images showed inhomogeneous internal attenuation (91%), irregularly undulating margins (91%), and vascular involvement (100%).     

Epidermal growth factor increases lung liquid clearance in rat lungs

Epidermal growth factor (EGF) has been reported to stimulate the proliferation of epithelial cells and increase Na+ flux and Na+-K+-ATPase function in alveolar epithelial cell monolayers. Increases in Na+-K+-ATPase in alveolar type II cells (AT2) have been associated with increased active Na+ transport and lung edema clearance across the rat alveolar epithelium in a model of proliferative lung injury. Thus we tested whether administration of aerosolized EGF to rat lungs would increase active Na+ transport and lung liquid clearance. Sixteen adult Sprague-Dawley male rats were randomized to three groups. To a group of six rats, an aerosol generated from 20 microgram of EGF in saline was delivered to the lungs, to a second group of five rats only aerosolized saline was delivered, and a third group of five rats without treatment served as the control. Forty-eight hours postaerosolization of rat lungs with EGF there was an approximately 40% increase in active Na+ transport and lung liquid clearance compared with control rats, in the absence of changes in 22Na+, [3H]mannitol, and albumin permeabilities. The Na+-K+-ATPase activity in AT2 cells harvested from these lungs was increased in rats that received aerosolized EGF compared with AT2 cells from both control rats and rats receiving aerosolized saline. These results support the hypothesis that in vivo delivery of EGF aerosols upregulates alveolar epithelial Na+-K+-ATPase and increases lung liquid clearance in rats.     

Importance of airway blood flow on particle clearance from the lung

The role of the airway circulation in supporting mucociliary function has been essentially unstudied. We evaluated the airway clearance of inert, insoluble particles in anesthetized ventilated sheep (n = 8), in which bronchial perfusion was controlled, to determine whether airway mucosal blood flow is essential for maintaining surface transport of particles through airways. The bronchial branch of the bronchoesophageal artery was cannulated and perfused with autologous blood at control flow (0.6 ml.min-1.kg-1) or perfusion was stopped. With the sheep in a supine position and after a steady-state 133Xe ventilation scan for designation of lung zones of interest, an inert 99mTc-labeled sulfur colloid aerosol (2.1-microns diameter) was deposited in the lung. The clearance kinetics of the radiolabeled particles were determined from the activity-time data obtained for right and left lung zones. At 60 min postdeposition of aerosol, average airway particle retention for control bronchial blood flow conditions was 57 +/- 7 (SE)% for the right and 53 +/- 8% for the left lung zones. Clearance of particles was significantly impaired when bronchial blood flow was stopped, e.g., right and left lung zones averaged 77 +/- 6 and 76 +/- 7% at 60 min, respectively (P < 0.05). These data demonstrate a significant influence of the bronchial circulation on mucociliary transport of insoluble particles. Potential mechanisms that may account for these results include the importance of the bronchial circulation for nutrient flow, maintenance of airway wall temperature and humidity, and release of mediators and sequelae associated with tissue ischemia.     

Alveolar macrophage kinetics and multinucleated giant cell formation after lung injury

Multinucleated giant cells (MGC) are a prominent feature of some chronic inflammatory states in the lung. These cells are formed by macrophage fusion, but how this process relates to the kinetics of alveolar macrophage (AM) production and proliferation is not clear. In this serial study, we compare AM kinetics and MGC formation after instilling carbon, silica, asbestos, bleomycin, and saline into the lungs of mice. Animals were killed up to 16 weeks later with [3H]thymidine injected 1 h before death. Counts of AM and MGC were carried out after bronchoalveolar lavage, and cell labeling was assessed by autoradiography. All test substances induced an inflammatory response with equal AM numbers recovered up to 2 weeks. Subsequently, the number returned to normal after carbon but remained elevated in the other groups. After carbon the lung structure was normal, there was no increase in AM label, and no MGC formed. Bleomycin-injected lungs progressed to fibrosis with only a brief, small increase in AM labeling and no MGC formation. After silica, and particularly asbestos, the lungs showed fibrosis, and many granulomas with large MGC were seen. Lavaged AM from these lungs showed a significant increase in DNA synthesis after 2 weeks, followed by higher numbers of MGC, none of which were labeled. Labeled AM tended to be free of particles, whereas MGC after 4 weeks contained many particles. The results indicate a relationship between AM proliferation and fusion, whereby AM growth appears to be prerequisite for cell infusion and MGC formation as a feature of granulomatous disease.     

Prognostic impact of mutated K-ras gene in surgically resected non-small cell lung cancer patients

Mutated K-ras oncogenes have been detected in a third of lung adenocarcinomas, located usually in codon 12, its presence correlating negatively with survival. To further define the role of K-ras point mutations in non-small cell lung cancer, we studied the presence of mutated K-ras genes in surgical specimens from 66 patients. Polymerase chain reaction was performed from sections of formalin-fixed paraffin-embedded tissue. We screened for point mutations in codons 12, 13 and 61 of the K-ras gene by dot blot hybridization analysis with mutation-specific oligonucleotide probes. Ras gene mutations were present in 13 of 66 carcinomas (20%), nine in codon 12 and four in codon 61. Three squamous cell carcinomas harbored two different point mutations in K-ras codon 12. Mutated K-ras genes were found more frequently in squamous cell carcinomas (eight of 38) than in adenocarcinoma (three of 22). Analysis of nucleotide sequence disclosed a multifarious mutation pattern of K-ras codon 12, where the most common conversion was from glycine (GGT) to valine (GTT). K-ras point mutation positive subset had poorer survival, nine of the 13 patients died during the follow-up period as compared with 22 of 53 patients with no mutation in the K-ras gene (P = 0.01). The difference was also strikingly significant when stratified according to node status.     

Rb and p16INK4a expression in resected non-small cell lung tumors

Inactivation of the cyclin-dependent kinase inhibitor p16INK4a (CDKN2/MTS1) is documented in a wide variety of cancer cell lines and tumors. We have shown that loss of p16INK4a protein expression is a common event in early stage non-small cell lung cancer (NSCLC), correlates with a significantly worse survival, and is more common in higher stage disease. One hundred NSCLC tumors from patients undergoing definitive thoracotomies at a single institution were examined for p16INK4a and retinoblastoma protein (pRB) expression. Abnormal pRB staining was identified in 15% of the tumors, whereas 51% possessed aberrant p16INK4a protein expression. Tumors with aberrant expression of p16INK4a by immunohistochemistry were associated with a significantly worse survival (P=0.04). Additionally, the inverse correlation of pRB and p16INK4a expression previously noted in lung cancer cell lines and tumors was confirmed in this large cohort of patients, with 65% of the tumors demonstrating inverse expression of pRB and p16INK4a (p=0.00019). A statistically significant increase in aberrant p16INK4a expression, as well as inverse expression of p16INK4a and pRB, was seen with increasing pathological stage of disease. These findings establish the prognostic significance (of the absence of p16INK4, in resected NSCLC and confirm the critical importance of disrupting the pathway of cyclin-dependent kinase-mediated phosphorylation of pRB in the molecular oncogenesis and progression of NSCLC.     

1H spin-lattice relaxation parameters in the length of human intestine resected for cancer

1H spin-lattice relaxation curves were acquired for samples of intestinal adenocarcinoma (B) and of uninvolved tissue at the upper (A) and lower (C) resection margin of lengths of intestine taken at surgery from 20 patients. Each sample showed a wide distribution of relaxation times with the order of 90% of the signal in a single peak at long times. Several different single-parameter relaxation times computed from discrete-exponential analysis showed that most of the relaxation times for C and B are in the upper two-thirds of the range of times for A. The mean time for the tumor is about 10% longer (with p < 0.01) than for the upper resection margin. The difference between the tumor and the lower resection margin is not significant. Distribution width parameters associated with A and C were significantly larger than those associated with the tumors. Two-exponential fits indicate that the fast-relaxing component represents a smaller signal fraction for the tumor B than for A or C.     

Factors influencing ten-year survival in resected stages I to IIIa non-small cell lung cancer

OBJECTIVE: The purpose of this study was to determine (in survivors of 5 years after resection of their lung cancer) whether age, sex, histologic condition, and age have any influence on furthering survival beyond 5 years. METHODS: From 1973 to 1989, 686 patients were alive and well 5 years after complete resection of their lung cancers. Survival analysis was carried out with only deaths from lung cancer treated as deaths. Deaths from other causes were treated as withdrawals. Multivariate Cox regression was used to test the relationship of survival to age, sex, histologic condition, and stage. RESULTS: The population in this study had the following characteristics at the time of operation: The male/female ratio was 1.38:1, and the median age was 61 years. The histologic condition of their lung cancer was adenocarcinoma in 412 patients, squamous cell in 244 patients, large cell carcinoma in 29 patients, and small cell carcinoma in 1 patient. The stage of the disease was stage IA in 263 patients, IB in 261 patients, IIA in 12 patients, IIB in 68 patients, and IIIA in 82 patients. The extent of resection was a lobectomy or bilobectomy in 579 patients, pneumonectomy in 55 patients, and wedge resection or segmentectomy in 52 patients. A recurrence or a new lung primary occurrence was considered as failure to remain free of lung cancer. The median follow-up on all patients was 122 months from initial treatment. Of the 686 patients, 26 patients experienced the development of late recurrence and 36 new cancers, beyond 5 years. Overall survival for 5 additional years after a 5-year check point was 92.4%. Likewise, survival by nodal status was 93% for N0 tumors, 95% for N1 tumors, and 90% for N2 tumors. Survival by stage was 93% for stage I tumors and 91% for stage II or IIIA tumors. CONCLUSIONS: In patients with surgically treated lung cancer, neither age, sex, histologic condition, nor stage is a predictor of the risk of late recurrence or new lung cancer. The only prognostic factor appears to be the survival of the patient free of lung cancer for 5 years from the initial treatment, with a resultant favorable outlook to remain well for 10 or more years.     

Hyaluronan in human cerebrospinal fluid

We studied the concentration of hyaluronan in cerebrospinal fluid (CSF) in various diseases and attempted to define its reference interval. A radioassay utilizing cartilage proteins with affinity for hyaluronan was used in determining the concentration of 200 lumbar and 27 ventricular CSF specimens and 11 brain cyst fluids. Molecular weight distributions were determined by gel chromatography and localization in brain tissue by histochemistry. The hyaluronan level of lumbar CSF showed an increase with age; comparatively healthy children had (mean +/- SD) 50 +/- 41 micrograms/L (n = 40) and adults 166 +/- 77 micrograms/L (n = 9); i.e. significantly different values. The highest level was recorded in a patient with meningitis (> 8000 micrograms/L). More than 4000 micrograms/ L was noted in a patient with tumour metastasis in the cerebellum. Significantly elevated levels were especially found with spinal stenosis, head injury and cerebral infarction, but also in inflammatory medical disorders, hydrocephalus and encephalitis. We found no significant increase in multiple sclerosis and some other neurological diseases. Ventricular CSF of adults contained significantly less hyaluronan (53 +/- 73 micrograms/L; n = 16) than lumbar CSF. Hyaluronan in cyst fluids varied from 31 to 25,000 micrograms/L. Weight average molecular weight of hyaluronan in CSF was 2.9-3.0 x 10(5) and in brain tumour cyst fluid 2.4 x 10(6). In search for the origin of hyaluronan in CSF it was found that its concentration in the choroid plexus and leptomeninges was low, but that hyaluronan was accumulated in the superficial layer of the cerebral cortex. Continued screening for hyaluronan in CSF may be valuable in cases of inflammatory diseases, tumours and obstruction to CSF flow.     

Autologous tumor killing activity as a prognostic factor in primary resected nonsmall cell carcinoma of the lung

BACKGROUND: Cytotoxic activity of peripheral blood lymphocytes obtained during surgery against autologous fresh tumor cells has been reported. However, the role of lymphocyte autologous tumor killing or natural killer activity during the postoperative period remains obscure. In this article, the authors describe the importance of postoperative autologous tumor killing activity as a prognostic factor in patients with primary resected nonsmall cell lung carcinoma (NSCLC) after long term follow-up. METHODS: Forty-two patients who had resection of NSCLC, with primary culture of autologous tumor cells taken successfully, were studied. Cytotoxic activity against autologous, allogenic NSCLC and K562 leukemia cells was examined using peripheral blood lymphocytes obtained during the 2 weeks immediately following surgery. Factors related to prognosis were analyzed by univariate and multivariate analyses. RESULTS: The overall 5- and 10-year survival rates for the NSCLC patients were 40.5% and 27.5%, respectively. Statistical analysis of survival curves revealed a significant difference with regard to T classification (P = 0.025), N classification (P = 0.0015), stage (P = 0.028), and postoperative autologous tumor killing activity (P = 0.0008); there were no significant differences in relation to age, gender, histology, differentiation, visceral pleural invasion, resectability, surgical method, allogeneic tumor killing activity, or natural killer activity. Multivariate analysis demonstrated a significant correlation between disease recurrence and N classification (P = 0.0003), T classification (P = 0.023), stage (P = 0.001), and autologous tumor killing activity (P = 0.007), indicating independent prognostic significance. The phenotypes of the effector cells involved in autologous tumor killing activity were CD3(+), CD4(-), CD8(+), and CD11b(-). Autologous tumor killing activity was inhibited by competing unlabeled autologous tumor cells. CONCLUSIONS: Autologous tumor killing activity during the 2 weeks immediately following surgery is an important prognostic factor in resected NSCLC.     

The role of alveolar macrophages in Pneumocystis carinii degradation and clearance from the lung

Although studies indicate that alveolar macrophages participate in host defense against Pneumocystis carinii, their role in organism degradation and clearance from the lung has not yet been established. We, therefore, quantified the uptake and degradation of 35S-labeled P. carinii by cultured macrophages, demonstrating significant degradation of P. carinii over 6 h. We further evaluated the role of macrophages in elimination of P. carinii from the living host. Rats received either intratracheal PBS, liposomal PBS (L-PBS), or liposomal dichloromethylene diphosphonate (L-Cl2MDP), a preparation which leads to selective depletion of macrophages. Over 72 h, L-Cl2MDP-treated animals had loss of > 85% of their alveolar macrophages. In contrast, L-PBS-treated rats had cellular differentials identical to rats receiving PBS. Macrophage-depleted rats and controls were next inoculated with P. carinii and organism clearance was determined after 24 h. P. carinii elimination was evaluated with both cyst counts and an ELISA directed against glycoprotein A (gpA), the major antigen of P. carinii. Both assays indicated that macrophage-depleted rats had substantial inpairment of P. carinii clearance compared to L-PBS- or PBS-treated rats. These data provide the first direct evidence that macrophages mediate elimination of P. carinii from the living host.