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At least 19 recordsLinked to original sources

PubMed1975

Diffusing capacity, specific diffusing capacity and interpretation of diffusion defects.

Six pathophysiologic mechanisms of a reduced single breath CO diffusing capacity are discussed and the usefulness of relating carbon monoxide (CO) uptake to the functioning alveolar volume (DL/VA, specific diffusing capacity) is illustrated for several pulmonary diseases. In patients with emphysema and pulmonary emboli (pulmonary vascular occlusive disease), reduced CO uptake is associated with significantly reduced DL/VA and is compatible with reduction of pulmonary capillary bed. In patients with pulmonary alveolar proteinosis, improvement in CO uptake and DL/VA follows lung lavage and suggests that lung units partially filled with proteinaceous material are responsible for hypoxemia, reduced CO uptake and reduced DL/VA. In most cases of radiation fibrosis, sarcoidosis and miscellaneous interstitial fibrosis, reduced CO uptake is associated with a normal DL/VA and suggests that loss of alveolar units, both capillaries and alveoli, has occurred. New regression equations for DL and DL/VA are established for children and adults. DL/VA is linearly related to height and independent of age and sex, while different predictive equations must be used for DL for the 5 through 17 and 18 through 76 age groups. The new regression equations for DL show better correlation in adults we studied over 50 years of age than previous regression equations which use a constant reduction of 2 to 3 ml CO per minute per mm of mercury for each 10 years of adult aging.

Adolescent↗

PubMed1977

Transmembrane bone morphogenesis across multiple-walled diffusion chambers. New evidence for a diffusible bone morphogenetic property.

Bone generation and regeneration are associated with a bone morphogen that recruits mesenchymal cells for differentiation into bone. Experiments with particulate bone matrix gelatin implanted in multiple-walled diffusion chambers suggest that bone morphogen is a rapidly diffusible molecule, and consists of a noncollagenous bone morphogenetic protein (BMP). When particulate bone matrix gelatin is implanted inside of diffusion chambers constructed of two to five membranes, ranging from 300 to 750 cu micronm in total thickness, large deposits of bone develop on the outside. The volumes of the deposits of new bone are inversely proportional to the thickness (or distance) of transmission of the BMP. Transmission for long distances through interstitial fluid can be accounted for by a low molecular mass hydrophobic BMP, disseminated according to the laws of diffusion.

Animals↗

PubMed1979

[Measurement of global diffusion capacity for CO, membrane diffusion capacity for CO and capillary blood volume in patients with bronchial emphysema after fominoben HCl. Short- and long-time trials (author's transl)].

The effect of 3'-chloro-2'-(N-methyl-N-[(morpholino-carbonyl)methyl]-aminomethyl)-benzanilide hydrochloride (fominoben HCl, P-B 89 Cl, Noleptan) on the global and membrane diffusion capacities and on the capillary blood volume in patients with emphysematous bronchitis is described. All 3 parameters, independent of the severity of the emphysema and the resulting respiratory insufficiency, are increased. It can thus be concluded that fominoben by improving the ventilation-perfusion ratio leads to an enlargement of the active diffusion surface (capillary surface), from which the increase in the global diffusion capacity results. The site of action of fominoben for its positive effect on respiration is thus established as being in the alveoli.

Adult↗

PubMed1977

Proliferation of diffusion chamber colony-forming units (CFUD) in cultures of normal human bone marrow in diffusion chambers in mice.

Normal human bone marrow contains cells capable of forming colonies of hemopoietic cells in fibrin clots in diffusion chambers implanted intraperitoneally (i.p.) into irradiated mice. The present paper describes the proliferation of such colony-forming units (CFUD) in cultures in vivo. Cells harvested from diffusion chambers after 1-14 days of culture in 450-R irradiated mice contained CFUD, which formed neutrophilic, eosinophilic, or megakaryocytic colonies when tested by secondary culture in fibrin clot chambers. When bone marrow was precultured in irradiated mice at a concentration of 10(6) cells per chamber, an initial fall in the number of neutrophilic CFUD was observed. This decrease was followed by an increase to a maximum at day 2, and then a secondary decrease. The number of neutrophilic CFUD recovered after 2 days of preculture in irradiated mice varied between 60% and 250% of the number present before preculture. Preculture in nonirradiated mice resulted in a significantly lower recovery of neutrophilic CFUD. In vitro treatment of bone marrow cells with hydroxyurea (OHU) after 2 days of preculture in irradiated mice resulted in a 68% +/- 5% reduction in the number of neutrophilic CFUD. In contrast, OHU had no similar effect on precultures from nonirradiated mice. Both the recovery and sensitivity to OHU of eosinophilic CFUD were independent of host irradiation. Similarly, no effect of host irradiation on the recovery or the 3H-thymidine (3HTdR) labeling index of morphologically recognizable granulocytic cells was observed at day 2. The data suggest an effect of humoral host factor(s) on the proliferation of early precursor cells, which are or become committed to differentiate into the neutrophilic pathway in diffusion chambers.

Animals↗

PubMed1976

A diffusible stimulator of eosinophilopoiesis produced by lymphoid cells as demonstrated with diffusion chambers.

Previous experiments have indicated that eosinophilopoiesis is stimulated in lymphoid cell-dependent eosinophil responses to certain antigens. In order to study if the potential for this stimulation of eosinophilopoiesis is a function of lymphoid cells and can be expressed on challenge with the eosinophilia-inducing antigen, the diffusion chamber technique for the culture in vivo of murine hemopoietic cells has been modified. A quadrachamber diffusion assembly allows for the simultaneous maintenance in the same host of four cell populations, pairs of which are separated by a cell-impermeable Millipore diffusion membrane of defined porosity. Spleen cells for chambers were from normal mice and mice primed with tetanus toxoid; secondary challenge induces eosinophilia. These spleen cells were placed transfilter from isogeneic bone marrow cells and cultured in vivo for 6 days in normal mice that received tetanus toxoidintraperitoneally following chamber-assembly implant. The marrow cell transfilter from spleen cells of primed-donor origin exhibited significantly greater eosinophilopoiesis than contiguous-chamber marrow transfilter from normal spleen cells. Such stimulated eosinophilopoiesis was independent of total chamber marrow cellularity. The data indicated that antigen-stimulated lymphoid cells may be the source of an eosinophilopoietic factor.

Animals↗

PubMed1976

Measurement of Krogh's diffusion constant of CO2 in respiring muscle at various CO2 levels: evidence for facilitated diffusion.

Krogh's diffusion constant for CO2, KCO2, was determined in respiring muscle tissue at various levels of tissue PCO2, between 10 and 160 torr, using a technique described previously (Kawashiro et atl, 1975). With increasing mean tissue PCO2, KCO2 declined towards an apparently asymptotic value. The relationship between KCO2 (10(-9) mmol-cm(-1)-min(-1)-tor(-1)) and PCO2 (torr) at 37 degrees C could be approximated by the equation KCO2 = 17.3 [1 + 1.72 - exp(--0.027 - PCO2)]-At PCO2 = 0 torr KCO2 exceeded the asymptotic value, which was virtually attained at PCO2 = 100 torr, by more than a factor of two. Thus CO2 diffusion in muscle appears to be facilitated in the low PCO2 range. Specific CO2 production rate of tissue, which was determined simultaneously, did not vary with CO2 in the PCO2 range studied. Effects of facilitated CO2 transport on CO2 exchange in muscle are assessd using simple models. In the presence of CO2 facilitation muscle PCO2 is reduced, particularly during exercise.

Animals↗

PubMed1977

Diffusion rates of cell surface antigens of mouse-human heterokaryons. II. Effect of membrane potential on lateral diffusion.

The rate of appearance, in a population of mouse-human heterokaryons, of cells with intermixed mouse and human surface antigens may be used to estimate the rate of lateral diffusion of the antigens in a single cell. Most heterokaryons appear to restrict diffusion of their surface antigens. These restrictions are altered by exposing either heterokaryons or their parent cells to conditions that change cell surface membrane potential. Media containing unphysiological concentrations of potassium ion, drugs, affecting the Na+,K+ ATPase, or a channel-forming antibiotic, gramicidin, all affect lateral mobility of cell surface antigens in a manner consistent with a common effect on membrane potential.

Animals↗

PubMed1975

Diffusing capacity, membrane diffusing capacity, capillary blood volume, pulmonary tissue volume, and cardiac output measured by a rebreathing technique.

A rebreathing method for estimating diffusing capacity, membrane diffusing capacity, pulmonary capillary blood volume, pulmonary capillary blood flow, and pulmonary tissue volume consists of rebreathing into a bag for 15 sec while acetylene, (18O)-carbon monoxide, oxygen, and helium are continuously sampled by a mass spectrometer. Because the masses of carbon monoxide and nitrogen are nearly identical at 28, it was necessary to use a stable isotope, C18O, to distinguish this gas with the mass spectrometer. Comparison of the pulmonary capillary blood flow by the rebreathing technique with the simultaneously obtained indicator dilution measurement in anesthetized dogs revealed good agreement. Estimations of pulmonary tissue volume appeared to be quite reproducible and consistent; the values tended to be somewhat smaller and less variable among normal subjects than reported by other investigators. After subtraction of capillary blood volume, tissue volume was 311 plus or minus 73 ml at rest and increased significantly to 352 plus or minus 61 ml at 75 watts of exercise. Pulmonary tissue volume in dogs using the rebreathing method averaged 9.2 ml per kg of body weight, a mean comparable to previously reported estimates using the ether plethysmographic method. The slope of pulmonary capillary blood flow (cardiac output in normal subjects) as a function of oxygen consumption during exercise in normal subjects of 0.0060 times oxygen consumption in milliliter per min was identical to published values. The rebreathing technique provides a rapid, reliable, noninvasive method for estimating pulmonary hemodynamic parameters.

Acetylene↗

PubMed1975

Anti-immunoglobulin analysis by diffusion patterns of inhibition and facilitation of complementary lysis in agar. I. Diffusion-lysis patterns of heterologous guinea pig anti-immunoglobulins.

Anti-rabbit immunoglobulin-containing sera were produced by immunizing guinea pigs with guinea pig red cells sensitized with rabbit-produced haemolysin against them. Such sera, and their 7S and 19S fractions, were radially diffused in agar containing sheep red cells sensitized with rabbit haemolysin and fractions thereof. After diffusion, the preparations were treated with guinea pig complement, which produced partial lysis in the background and a series of alternating rings of more and less lysis than that in the background. These were interpreted as a due to the presence of at least four anti-immunoglobulins (anti-Ig's) as follows: a 19S anti-Ig which inhibited lysis by 7S and 19S haemolysin; a 7S anti-Ig which facilitated lysis by 7S and 19S heamolysin; a 7S anti-Ig which inhibited lysis by 7S and 19S haemolysin; a 7S anti-Ig which facilitated lysis by 19S haemolysin. Similar patterns were obtained using correspondingly produced sera against mouse immunoglobulin, and sensitizing the sheep cells in the agar with mouse-produced haemolysin.

Animals↗

PubMed1979

Diffuse parenchymal amyloidosis of lungs and breast. Its association with diffuse plasmacytosis and kappa-chain gammopathy.

A patient had systemic amyloidosis that extensively involved the lungs and breasts. Diffuse parenchymal pulmonary amyloidosis is rare but well described. Involvement of the breast in systemic amyloidosis is, however, most unusual. This patient's amyloidosis was associated with diffuse plasmacytosis and a kappa-chain gammopathy. The plasmacytosis was most prominent in the renal interstitium. Immunoperoxidase staining of the renal infiltrate and breast demonstrated IgG/kappa-staining plasma cells exclusively, suggesting that these cells were a monoclonal proliferation that contributed to the patient's M-protein and possibly to the patient's amyloid deposits.

Amyloidosis↗

PubMed1975

Anti-immunoglobulin analysis by diffusion patterns of inhibition and facilitation of complementary lysis in agar. II. Diffusion-lysis as a method for recognizing in vivo immunosuppressive activity of anti-immunoglobulins.

This paper provides evidence that it is possible to prepare facilitating anti-mouse immunoglobulin (that is, anti-mouse immunoglobulin which facilitates complementary lysis of red cells sensitized with mouse-produced haemolysin) which, when injected into mice 24 hours before an injection of sheep red cells, very markedly reduced the number of haemolysin-producing cells detectable in spleen four days later. The diffusion-lysis method was used to recognize this and other anti-Ig's in heterologous antiserum and fractions thereof. The effective antibody was in the gamma2 fraction of antiserum produced in guinea pigs by injecting them with guinea pig red cells sensitized with mouse-produced haemolysin. This method of immunizing was used in order to stimulate the production of antibody against immunoglobulin which had undergone the configurational change characteristically occurring when antibody unites with antigen. The 19S fraction of the antiserum contained inhibiting anti-mouse immunoglobulin (anti-mouse immunoglobulin which inhibits complementary lysis of red cells sensitized with mouse-produced haemolysin) and interfered with immune depression by the gamma2 fraction. It is postulated that the gamma2 fraction induces complementary lysis only of lymphocytes whose surface immunoglobulin receptors have bound antigen and undergone configurational change. It is suggested that facilitating anti-immunoglobulin of the type described is responsible for immune suppression by anti-lymphocyte serum (ALS). Facilitating anti-mouse immunoglobulin was demonstrated in two samples of ALS (anti-mouse) which were active in suppressing graft rejection, but inhibiting anti-mouse immunoglobulin only was found in a sample which was ineffective in suppressing graft rejection.

Agar↗

PubMed1976