Injection and flow control system for microchannels.

In spite of considerable efforts, flow control in micro-channels remains a challenge owing to the very small ratio of channel/supply-system volumes, as well as the induction of spurious flows by extremely small pressure or geometry changes. We present here an inexpensive and robust system for flow control in a microchannel system, based on a dynamic control of reservoir pressures at the end of each channel. This system allows flow equilibration with a time constant smaller than one second, and is also able to maintain stable flux from stopped flow to many microl min(-1) range over several hours. It is robust to changes in ambient pressure and temperature. This system further includes a feature for sub-microliter sample injection during the experiment. We quantify flow control in elastomer and thermoplastic channels, and demonstrate the impact on one application of the system, namely the reproducible, automated separation of large DNA by electrophoresis in a self-organized magnetic bead matrix in a microchannel.

[Treatment of rhabdomyosarcoma in mice C3H/He by Co 60 and hyperbaric oxygen (author's transl)]. / Traitement du rhabdomyosarcome chez la souris C3H/He par cobalthérapie sous oxygène hyperbare.

UNLABELLED: Experimental study of rhabdomyosarcoma with successive transplantation upon C3H/He mice, treated by irradiation (Co 60) and combined irradiation-hyperbaric oxygen (HBO), dating from 3, 14 and 15 days after transplantation. The data (tumor volume evolution, histological modifications, pulmonary metastases) are compared with controls. CONCLUSIONS: curative radiotherapy depends on starting treatment as soon as possible with or without HBO. After the 14th day, sensitisation to combined HBO and C60 is seen. The extension of pulmonary metastases is a function of tumor growth. Paradoxically metastases were less frequent after HBO only and more frequent after HBO-Co 60.

[Karyotypes, supernumerary chromosomes, rudimentary parthenogenesis and polyploidy in 2 species of the genus Phronima (Crustacea, Amphipoda)]. / Caryotypes, chromosomes surnuméraires, parthénogenèse rudimentaire et polyploidie chez deux espèces du genre Phronima (Crustaces, Amphipodes)

The diploid number of Phronima sedentaria and P. atlantica is 30, all the chromosomes are metacentric or submetacentric; the caryotypes of these two species are compared with those of other Amphipods. Some individuals of each species have a supernumerary chromosome. This element, found in both sexes, remains as an univalent at meiosis and goes earlier to one pole. In some cases nonfertilized ova undergo segmentation; this rudimentary parthenogenesis stops quickly and is partly related to polyploidization.

A canonical discriminant analysis of post-embryonic development in Notonecta Maculata fabricius (Insecta:Heteroptera).

A multivariate method, canonical discriminant analysis, was used to discern a pattern of growth in Notonecta maculata. A stepwise procedure reduced the 11 metrical characters measured on individuals of both sexes, from the 1st larval stage to the adult, to 4 significant variates which were used in the canonical analysis. The four canonical variates accounted for the meaningful part of the variablity. Relying on bivariate allometry and on an experimentation with a juvenile hormone analogue, each independent direction of variation was related to combined effects of such biological factors as a general growth trend, sex and juvenile hormone.

[Is long term medical follow up of tuberculous patients possible? (author's transl)]. / La surveillance hospitalière au long cours des tuberculeux est-elle possible?

Tuberculosis still remains a current disease, of difficult eradication as shown by numerous studies and epidemiological surveys. The authors studied 180 newly affected tuberculous patients admitted to Pr. Laval's department at Marseille and tried to discover why only 91 (50.6%) were still followed or could be traced 3 years after their first hospitalization. Five parameters were studied: origin, sex and age, living area, socio-economical data (change of address, lack of accomodation, profession), tobacco and alcohol addiction. No significant part was played by nationality, living area, or profession. On the other hand, changing of address, chronic tobacco and alcohol addiction were the factors responsible for loosing sight of the patients. An attempt to define this tuberculous patient, which would not be followed up for long, gave the picture of a 40 to 45 years old man, living in a hotel or with no fixed accomodation, smoking more than 20 cigarettes a day and drinking. Such a profile of a tuberculous patient should increase the watchfulness over likely ones.

[Complications of lymphography. A propos of 5 cases]. / Complications de la lymphographie. A propos de cinq observations

Complications noted following lymphography have been published by several authors. The authors report here a series of 5 cases occurring in patients with mediastinal and lung cancer. They report the various clinical manifestations resembling fat embolism, the free interval and general signs, pulmonary, neurological, hematological and dermatological symptoms associated with inconstant laboratory abnormalities which permit one to suggest a complex pathogenesis: --Immuno-allergic (early shock due to circulating antibodies). --Mechanical and vascular: incomplete removal of low viscosity lipiodol by the pulmonary macrophage system permits liberation of micro-vascular emboli. --By abnormality of blood coagulation and the onset of a syndrome of widespread intravascular coagulation. Better recognition of the pathogenesis associated with the development of new therapeutic principles, should permit better prevention and control of these complications.

[Contribution to the study of the phagocytosing ability of broncho-alveolar macrophages in smokers and non-smokers (author's transl)]. / Contribution à l'étude du pouvoir phagocytaire des macrophages broncho-alvéolaire chez les fumeurs et les non fumeurs.

Broncho-alveolar macrophages were obtained by bronchial washing from 20 pairs of matched smokers and non-smokers. The following parameters were studied: phagocytosing ability of macrophages on silica in cell culture in the presence or absence of cotinin, a biocompound of nicotin; migration inhibitory factor (MIF), and power and level of alpha 1-antitrypsin in sera of patients. The results are reported as a function of absolute number of macrophages obtained, their viability, the amount of cigarettes smoked, and the action of cotinin. MIF was stronger in the smokers. There was no difference between the groups as far as power and level of alpha 1-antitrypsin are concerned. Cotinin provokes important lesions in the macrophages. The phagocytic power was not significantly different in smokers and non smokers, but the results were better in non-smokers.

[Smoking habit at school. First habit at school. First results of a survey done in Marseille and its suburbs (author's transl)]. / Le tabagisme scolaire. Premiers résultats d'une enquête réalisée dans l'agglomération marseillaise.

The authors report the first results of a transversal survey done from the end of November 1976 to the end of April 1977 in 4 secondary schools (CES, CEG) in Marseille and its suburbs. 1.795 children, between 11 and 15, in the first and fourth form, filled up a questionary inquiring into their smoking habits and consumption. Already a certain number of results can be drawn: --in this group of children, mostly girls (926 G/882 B) 181 were regular smokers (10,07%); --among these smokers, 70 smoked every day (38,6%), 60 smoked more than a packet a week (33%), finally 122 inhaled smoke; --they acquired the habit of smoking regularly between the age of 14 and 15, in the 3rd and 4th forms, as there was only 9,4% of smokers in the 3rd and 19% in the 4th form; --finally, parents seem to play a fundamental inducing part in this habit, as among smoking children 32.8% have parents both smoking, 41% a smoking mother, 71.2% a smoking father, while for non smokers the percentage were respectively of 19.9%, 24.9% and 54.3%.

[Methodologic problems concerning pharmacology effect on bronchomotricity in asthma (Raw, V/V) (author's transl)]. / Problèmes méthodologiques pour apprécier l'action pharmacologique sur la bronchomotricité chez les asthmatiques à partir des mesures des Rva et des boucles V/V.

Study of spirometric, flow-rate and Raw modifications in three groups of 5 to 8 asthmatic patients (stage I or II) before and after acetylcholine and pneumallergen (dust) action is made. The same modifications were studied on the action of dust before and after a chemical protector effect. In two control groups the following parameters were verified: 1) the stability of Raw and V/V (normal subjects: 8); 2) the reproductibility of the acetylcholine bronchospasm, before and after the action of chemical protector (asthmatic patients: 11). Some considerations about the methodology in the practice of bronchomotricity data are submitted.

[Respiratory function profile in scleroderma. 20 cases (author's transl)]. / Profil fonctionnel respiratoire dans les sclérodermies.

This study involved 20 patients, 13 female and 7 male, with a mean age of 49 years, suffering from localized (6 cases) scleroderma or generalized without Raynaud's syndrome (6 cas), with Raynaud's syndrome (6 cas) or acrosclerosis (2 cases). Respiratory function tests included study of volumes, flow rates, CO transfer (TLCO) and blood gases. There were 38% normal chest X-rays, 58% ventilatory disturbances (predominance of restrictive syndrome and decrease in (TLCO) was found in only 25% of cases. The authors emphasize the extent of pulmonary vascular lesions in these patients.

[Dermatoglyphics of subjects with bronchial cancers]. / Les dermatoglyphes des sujets atteints de cancers bronchiques.

Every high smokers are not able to make a lung carcinoma, on the over hand nonsmokers can be able to develop a bronchial carcinoma. It is possible that genetic factors can be involved in the occurrence of this carcinoma. Dermatoglyphic studies are one of the technics to appreciate this problem. The study was done upon 37 bronchial carcinoma and 51 lung diseases (European origin, only man, same age). There are some big differences upon: --The Cummins index: the right index as well as the left are higher in bronchial carcinoma than in controls, but it is significative only for the right one (p less than 0,05) (28,89 +/- 3,7 to 26,88 +/- 4,55). --The frequency of the ten fingerprints: the differences between lung carcinoma and controls are highly significative (p less than 0,01) for the whorls (22,7 to 34,9) and slightly significative (p less than 0,05) for the ulna loops (65,4 to 57,4), the other fingerprints (arch, radial loops) are quite the same in the two groups. The studies upon the other figures (TFRC and the position of the axial tri-radius) do not show any differences. It seems to us that the dermatoglyphic studies of men with bronchial carcinoma differ from controls (hospitalized for lung diseases). These population have the same dermatoglyphic structure than a control population from blood donors of Marseilles. The dermatoglyphic studies can be an aid to identify high risk people.

Evaluation of the distribution of air and blood in emphysema patients using radioisotopic tracers.

Continuous recording of the respiratory cycle with the simultaneous or sequential radionucleic exploration (gamma camera) of ventilation (133Xe) and perfusion (MAT-99) was performed to determine the V/Q index in regional areas (Polaroid photography, mini-computer, memory visualization system, Benson incremental tracer, etc.) from the level of 1,024 points. An average ratio per sector was calculated and only three median sectors were retained. The wash-in and wash-out curves were traced by computer, and the calculation of the average T 1/2 for the different compartments of each median sector (apex--middle and base) was done in about 22 observations: in 18 diffuse emphysema, 11 of which were associated with giant cystic emphysema (spirometric, plethysmographic and radiographic data), T 1/2 values were greater than those of normal subjects (compartments C1 and C2) in diffuse emphysema and can become indefinable in zones of cystic emphysema. The values of the index V/Q approach the normal in diffuse emphysema with a tendency toward equalization of the ratios from the apex to the base. Extremely large divergence is observed in the elevated V/Q ratios in cystic emphysema.

[The value of body tomodensitometry for diagnosis in pneumology]. / Apports de la tomodensitometrie corporelle dans le diagnostic en pneumologie.

The authors present a preliminary work on 37 pulmonary tomodensitometry performed on 18 bronchial cancers, 7 pleuro-pulmonary metastases, 4 normal lungs and 8 various respiratory diseases. This method presents a double advantage:--first it localizes the affection in relation to pleura, mediastinum or heart; specially interesting in case of a transparietal puncture in carcinology;--secondly, densitometry enables a differentiation between dense tumoral tissue and ventilatory disorders or pleurisy; it is also useful in determining the tumoral target volume. Finally this new technique can show air cavities (emphysema, tuberculous or cancerous caverns) as well as pleurisies of small volume.