Responses of trembling aspen and hazelnut to vapor pressure deficit in a boreal deciduous forest.

The branch bag method was used to monitor photosynthesis and transpiration of trembling aspen (Populus tremuloides Michx.) and hazelnut (Corylus cornuta Marsh.) over a 42-day midsummer period in 1996, as part of the Boreal Ecosystem-Atmosphere Study (BOREAS). During the same period, daytime measurements of stomatal conductance (g(s)) and leaf water potential (Psi(leaf)) were made on these species, and sap flow was monitored in aspen stems by the heat pulse method. Weather conditions during the study period were similar to the long-term average. Despite moist soils, both species showed an inverse relationship between daytime g(s) and vapor pressure deficit (D) when D was > 0.5 kPa. Daytime Psi(leaf) was below -2 MPa in aspen and near -1.5 MPa in hazelnut, except on rainy days. These results are consistent with the hypothesis that stomatal responses are constrained by hydraulic resistance from root to leaf, and by the need to maintain Psi(leaf) above a minimum threshold value. Reductions in g(s) on sunny afternoons with elevated ambient D (maximum 2.3 kPa) were associated with a significant decrease in photosynthetic rates. However, day-to-day variation in mean carbon assimilation rate was small in both species, and appeared to be governed more by solar radiation than D. These results may be generally applicable to healthy aspen stands under normal midsummer conditions in the southern boreal forest. However, strong reductions in carbon uptake may be expected at the more extreme values of D (> 4 kPa) that occur during periods of regional drought, even if soil water is not locally limiting.

A simplified closed artificial ecosystem--recycling of organic matter into wheat plants.

A simplified closed system consisting of a plant growth chamber coupled to a decomposition chamber was used to study carbon exchange dynamics. The CO2 produced via the decomposition of wheat straw was used for photosynthetic carbon uptake by wheat plants. The atmosphere of the two chambers was connected through a circuit of known flow rate. Thus, monitoring the CO2 concentrations in both compartments allowed measurement of the carbon exchange between the chambers, and estimation of the rate of respiration processes in the decomposition chamber and photosynthetic rate in the producer chamber. The objective for CELSS research was to simulate a system where a compartment producing food via photosynthesis, would be supplied by CO2 produced from respiration processes. The decomposition of biomass by the decomposer simulated both the metabolism of a crew and the result of a recycling system for inedible biomass. Concerning terrestrial ecosystems, the objective was to study organic matter decomposition in soil and other processes related to permanent grasslands.

Transpiration of a boreal pine forest measured by branch bag, sap flow and micrometeorological methods.

Three independent methods were used to evaluate transpiration of a boreal forest: the branch bag, sap flow and eddy covariance methods. The branch bag method encloses several thousand needles and gives a continuous record of branch transpiration. The sap flow method provides a continuous record of sap velocity and an estimate of tree transpiration. The eddy covariance method typically measures evaporation rates between a forest and the atmosphere. We deployed an extra eddy covariance system below the forest to estimate canopy transpiration by difference. The three systems detected small water vapor fluxes despite a plentiful supply of energy to drive evaporation. We also observed that transpiration rates were low even when the soil was well supplied with water. Low rates of transpiration were attributed to the canopy's low leaf area index and the marked reduction in stomatal conductance as vapor pressure deficits increased. Water vapor fluxes, derived from the sap flow method, lagged behind those derived by the branch bag method by 1 to 2 h. The sap flow method also suffered from sampling errors caused by the non-uniformity of flow across the sapwood and the spatial variability of sapwood cross section throughout the forest. Despite technical difficulties associated with hourly measurements, daily totals of transpiration agreed well with values derived from micrometeorological systems.

Long-term cure of a non-small-cell lung cancer treated by monochemotherapy.

Cure after 8 years of a non-small-cell lung cancer (NSCLC), inoperable because of locoregional spread, is reported. The authors believe this case represents the longest survival after monochemotherapy reported to date and provides the opportunity to review studies of prognostic factors concerning long-term survival in NSCLC.

Prospective study of combined use of bronchial aspirates and biopsy specimens in diagnosis and typing of centrally located lung tumours.

OBJECTIVE: To determine the diagnostic accuracy of examining bronchial secretions in pulmonary cytopathology and whether cytology and histopathology can complement each other in routine practice among lung specialists. DESIGN: A prospective study comparing 1225 cytological and biopsy results, conducted during 1987-93. Tumours were confirmed by histopathology, imaging techniques, or clinical outcome and imaging techniques combined. SETTING: 11 lung or internal medicine units, France. SUBJECTS: 1128 patients (874 men; 254 women) aged 65.3 (SD 13.7) years who underwent fibreoptic bronchoscopy for various pulmonary symptoms. RESULTS: Exact concordance between cytological and biopsy results was obtained in 1036/1187 (87.3%) satisfactory specimens. In all 574 lung tumours were diagnosed. One case (0.08%) was a false positive cytological diagnosis in a patient with tuberculosis. Patients with lung cancer were more likely to have positive cytological results than positive biopsy results (P < 0.001). Agreement in tumour typing was observed in 375/424 (88.4%) cases, when non-small cell carcinomas, small cell carcinomas and undifferentiated carcinomas were separated. In the 11 patients with squamous cell carcinomas in situ, eight (72.7%) of the carcinomas were diagnosed cytologically as squamous cell. Unsatisfactory material was obtained in only 20 (1.6%) and 19 (1.6%) cases by cytology and biopsy respectively. Examinations had to be repeated in 86 (7.6%) patients. CONCLUSIONS: Examination of bronchial secretions complements histopathology in both diagnosing and typing lung tumours and could be performed more systematically in patients undergoing fibreoptic bronchoscopy.

[Bronchial aspiration in the typing of bronchopulmonary cancers: apropos of 150 cytobiopsy correlations]. / L'aspiration bronchique dans le typage des cancers bronchopulmonaires: à propos de 150 corrélations cytobiopsiques.

We analysed 150 cases of primary lung cancers investigated by bronchial aspirate and biopsy methods with clinical, radiologic and bronchoscopic findings. Among the 150 cases studied, three were characterized by mixed tumor cell components, thus allowing 153 cyto-histological comparisons. The cytologic and histopathologic typing agreed strictly in 102 cases of 153 (66.7%) and was considered as correct in 40 cases (26.1%). Only cases with divergent evaluation between small-cell carcinoma and non small-cell carcinoma were considered as discordant: such misclassification occurred in 11 specimens (7.2%), including two cases with mixed patterns. The cytologic typing was in agreement with the final diagnosis in all epidermoid carcinomas, adenocarcinomas, large-cell carcinomas and poorly differentiated carcinomas. In small-cell carcinomas, cytology was in agreement with histopathology in 20 of 26 cases (77%), and could only indicate undifferentiated features in four cases (15.4%). The analysis of bronchial aspirate specimens gave reliable typing in 92% of cases, and indicated a better tumor cell differentiation than histopathology in 6.5% of cases. The results obtained show that aggressive treatments can be reliably proposed on the basis of cytologic findings, even without tissue corroboration. This proposal is particularly helpful in cases where biopsy cannot be performed (peripheral lesions) or creates a danger to the patient (iatrogenic hemorrhage).

A simplified ecosystem based on higher plants: ECOSIMP, a model of carbon cycle.

An experiment of Artificial Ecosystem in closed growth chambers is described. It comprises a biomass producer compartment coupled with a decomposer compartment. A model of carbon cycle is presented, simulating the CO2 changes in atmosphere and the carbon status in plants and in the decomposer system. Results of variation in several parameters such as photoperiod, rate of photosynthesis, percentage of harvested biomass introduced in decomposer, kinetics of biomass decomposition, are presented. Positive conclusions are deduced about the feasability of real experiments without particular control of CO2 nor buffering system. Applications in studies on plant-soil-atmosphere ecosystems, for spatial and terrestrial researches, are discussed.

[A case of semi-delayed hypersensitivity to dry sausage dust]. / Un cas d'hypersensibilité semi-retardée à la poussière de saucisson sec.

The authors record a case of semi-delayed hypersensitivity to sausage dust in an employee of a wholesale pork butcher and curing business. The symptoms combined cough and fever with rigors; there were no clinical or laboratory data to suggest alveolar disease. The immunoallergic "work-up" suggested a precipitin mediated disease with notably 10-14 precipitation arcs to the products of sausage sweepings. A microbiological analysis of the flora of the sausages, as well as an extensive search for precipitins and cutaneous tests have not enabled us to confirm the antigen responsible with certainty.

[Alveolar cancer and localized parieto-alveolar fibrosis]. / Cancer alvéolaire et fibrose pariéto-alvéolaire localisée.

We report a case, cytologically diagnosed, of broncho-alveolar cancer associated with localised interstitial pulmonary fibrosis. This association of fibrosis with bronchiolo-alveolar cancer is classical and a pathogenic affiliation has been deduced by the majority of authors. We review the pathogenesis in relation to recent datas concerning the activation of successive oncogenes: the first stage of carcinogenesis may correspond to the activation of an oncogene coding for a fibroblastic growth factor leading to fibrosis.

[Partial deficiency of cell-mediated immunity in some cases of bronchiectasis (author's transl)]. / Déficit partiel de l'immunité cellulaire dans certaines formes de bronchectasies.

Two case-reports are presented to support the hypothesis that bronchiectasis may occasionally be associated with a partial deficiency of T lymphocyte functions. This deficiency would represent another etiology of the heterogenous sino-pulmonary syndrome of which several causes have been identified or postulated: immunoglobulin deficiency, alpha-1-antitrypsin deficiency, mucociliary abnormality, phagocytosis or bactericidia abnormalities, etc.

["Small cell" carcinoma of the lung. Results obtained using combination chemotherapy (adriamycin, vincristine, cyclophosphamide) in 38 patients (author's transl)]. / Cancer pulmonaire à "petites cellules" Résultats de l'association adriamycine-vincristine-cyclophosphamide chez 38 patients.

A cyclic and sequential combination of adriamycin, vincristine (or VM 26) and cyclophosphamide was used, with a follow up of 4 to 33 months in 38 patients with a "micro-cellular" carcinoma of the lung. Radiotherapy was used in association in a variable manner. Chemotherapy alone resulted in marked regression of the lesions (regression is greater than 50%) in approximately 65 per cent of cases and a level of complete regression which varied from 31 to 45 per cent according to the degree of diffusion of the lesions at the time of admission. In this study, survival in apparently localised forms was 70 per cent after one year and 55 per cent at eighteen months, whilst it was 34 per cent at one year and nil at eighteen months in patients with evidence of metastatic disease at the time of entry. These encouraging results indicate a hope for improvement, in certain patients reacting favourably to this protocol, in the still grave prognosis of "small cell" carcinoma of the lung.

[Alpha-1-antitrypsin deficiency. Phenotype study of 60 members of the same family]. / Déficit en alpha-1-antitrypsine. Etude du phénotype de 60 membres d'une même famille

In two brothers treated for severe pulmonary emphysema, was demonstrated an alpha-1-antitrypsin deficiency associated with a ZZ phenotype (Pi system). The authors carried out a genetic study of the family including 60 members spread over 4 generations. In all, were demonstrated 4 subjects of phenotype ZZ, 29 of phenotype MZ, 3 of phenotype MS ; one subject had a phenotype SZ and 23 members of this family had normal levels of alpha-1-antitrypsin and were of phenotype MM. The disease was transmitted in all cases as an autosomic codominant. The interest of a study of the phenotype in alpha-1-antitrypsin deficiency is emphasized together with the practical steps to be taken on discovery of a subject with the allele responsible for a reduction in serum levels of alpha-1-antitrypsin.

[Effusions rich in amylase without pancreatitis. 14 cases]. / Les épanchements riches en amylase en dehors des pancréatites. Quatorze observations

This study involved 14 cases or pleural effusions or ascites rich in amylase and unrelated to chronic pancreatitis, a pseudo-cyst of the pancreas or acute pancreatitis. A pleural effusion rich in amylase may be secondary to a pancreatic neoplasm but this possibility seems rare. Amylase-containing effusions related to a nonpancreatic neoplasm are more common. The lesion is in general an advanced pleuro-pulmonary carcinoma, frequently an adenocarcinoma. The amylase activity of neoplastic effusion fluid is significantly increased but although levels similar to those of certain pancreatic effusions may be seen, very high figures would appear to be rare. Finally, two cases of amylase-rich pleural effusions were related to a pleuro-digestive fistula and one left-sided effusion was secondary to abdominal trauma.