Comparative hemodynamic effects of periodic obstructive and simulated central apneas in sedated pigs

Chen, Ling, and Steven M. Scharf. Comparativehemodynamic effects of periodic obstructive and simulated centralapneas in sedated pigs. J. Appl.Physiol. 83(2): 485-494, 1997.It has beenspeculated that because of increased left ventricular (LV) afterload,decreased intrathoracic pressure (ITP) is responsible for decreasedcardiac output (CO) in obstructive sleep apnea. If this were true, thenobstructive apnea (OA) should have a greater effect on CO than wouldcentral apnea (CA). To assess the importance of decreasedITP during OA, we studied seven preinstrumented sedated pigs with OAand simulated CA that were matched for blood gases and apneaperiodicities (with 15- or 30-s apnea duration). Compared with OA, CAwith 30-s apnea duration produced comparable decreases in heart rate(from baseline to end apnea: OA, 106.6 ± 4.8 to 93.4 ± 4.4 beats/min, P < 0.01; and CA, 111.1 ± 6.2 to 94.0 ± 5.2 beats/min,P < 0.01) and comparable increasesin LV end-diastolic pressure and LV end-diastolic myocardial segmentlength but greater increases in mean arterial pressure (97.1 ± 3.7 to 107.7 ± 4.3 Torr, P < 0.05;and 97.3 ± 4.8 to 119.3 ± 7.4 Torr,P < 0.01) and systemic vascularresistance (2,577 ± 224 to 3,346 ± 400 dyn · s · cm⁵,P < 0.01; and 2,738 ± 294 to5,111 ± 1,181 dyn · s · cm⁵,P < 0.01) and greater decreases inCO (3.18 ± 0.31 to 2.74 ± 0.26 l/min,P < 0.05; and 3.07 ± 0.38 to2.30 ± 0.36 l/min, P < 0.01) andstroke volume (32.2 ± 2.9 to 25.9 ± 2.4 ml,P < 0.05; and 31.5 ± 1.9 to 19.8 ± 3.1 ml, P < 0.01). Only CA increased LV end-systolic myocardialsegment length. Similar findings were observed with 15-s apneaduration. We conclude that CA produced greater depression of CO andgreater changes of afterload-related LV dysfunction than did OA.Therefore, decreased ITP was not the dominant factor determining LVfunction with apneas.

     

禾木科植物染色体消除型远缘杂交的研究进展

植物远缘杂交是作物育种中广泛应用的技术。除了核型稳定的种间杂交可以获得杂种以外,还可以利用核型不稳定的种间杂交后父本染色体消除的现象,通过胚培养和染色体加倍处理获得加倍单倍体(     

Analysis der Basalstoffwechselregelung in Abhängigkeit von Umweltfaktoren und Körpergewicht

In large-scale experiments carried out over a period of about 15 years, white rats were subjected to chronic treatment with antithyroid drugs, substances counteractingLangerhans' islets (mostly alloxan), hormone fragments, and native hormones respectively. The O₂-consumption (mostly in an artificial microclimate) was measured in each test. The test batches were either gradually diminished by killing the animals one after another, to yield histological series in chronological order, or a whole batch was pooled together at the end of a test. In all experiments a relationship could be established between O₂-consumption and the histology (histochemical tests included) of liver and endocrine glands. In a recent experiment, moreover, serum enzymes and the level of blood sugar were determined; a chromatographic analysis of thyroid hormone fractions and blood cells-counts were made. Combining these methods led to numerous variables suitable for numerical treatment. Besides a treatment of the data by elementary methods (variance analysis, t-test, U-test, linear 2-dimensional regression analysis), multidimensional space models, employing traditional and novel calculi were used. The regression equations in 23-dimensional statements were linear, quadratic and cubic. In a concordance analysis 25 variables were carried along. To develop a satisfactory theory, the coefficients of the differential equations underlying the material were determined by means of an approximation method suited for random samples subject to variance. For solution, integrals, polynomials of e-functions, using mostly the regression calculus in two steps were sought. The oscillations caused by environmental factors were extracted as the differences between the function values of the optimal particular and real integral and the empirical ordinates. This isolated swinging remainder was analysed followingFourier. The spectra or the oscillation portions themselves were brought into functional relation with one another by means of functional operators always controlled by hetero- and auto-correlation. The model of the control of metabolism by the diencephalic-pituitary-thyroid-system could thus be reduced to an n-dimensional linear space model, which, however, is not quite satisfactory.     

Neuere Aspekte zur altersabhängigen Involution des sensiblen peripheren Nervensystems

Zusammenfassung An Hand von Befunden aus der Literatur und aus dem eigenen Laboratorium beschreiben die Autoren die Altersveränderungen in den sensiblen Ganglien. Es zeigt sich, daß jenseits des 35. Lebensjahres zunehmend sensible Neurone degenerieren. Sodann wird auf Grund von Befunden aus der Literatur (Ronge, 1944; Bolton, Winkelmann und Dyck, 1966) das Problem der vom Hautwachstum und von der altersbedingten Involution abhängigen Anzahl der Meissnerschen Tastkörperchen pro Hautflächeneinheit mathematisiert. Die Abhängigkeit allein von der Zeit kann durch eine gewöhnliche Differentialgleichung 4. Ordnung beschrieben werden, die linear in den konstanten Koeffizienten ist. Soll dagegen die wachstumsbedingte Flächenänderung der Haut berücksichtigt werden, kann als adäquates Modell eine hyperbolische (homogene, lineare, partielle) Differentialgleichung (2. Ordnung) akzeptiert werden. Es werden partikuläre Integrale für beide Differentialgleichungen angegeben, die mit den Befunden in Einklang stehen.

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Summary On the basis of results given in the literature and on own laboratory findings the authors describe age-dependent changes in the sensory ganglia. Beyond the 35th year of age the number of neurons undergoing degeneration increases. In a mathematical analysis it is shown how the number of Meissner corpuscles per unit of skin depends on the growth- rate of the skin and the age-dependent involution. The dependence from time can be demonstrated by an ordinary differential equation of 4th order which is linear in the constant coefficients. If, however, the growth-dependent increase per area skin is to be considered, a hyperbolic differential equation (which is linear, homogeneous, and with variable coefficients) seems to be an adequate model. Particular integrals, which satisfy the values of measurement are given for both, the ordinary and the partial differential equation.

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Herrn Professor Dr. Ludwig v. Bertalanffy in Verehrung und Dankbarkeit und mit herzlichsten Glückwünschen zum 65. Geburtstag gewidmet.

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Mit dankenswerter Unterstützung durch einen Forschungsauftrag des Staatssekretariates für Hochschulwesen der DDR.Rechentechnische Assistenz: Leit. Med.-techn. Ass. Ruth Pieper.Phototechnik: Oberpräparator Fritz Henkel. — Graphische Gestaltung: Akad. Bildhauer Hellmut Helwin.     

A Highly Conserved Residue of the HIV-1 gp120 Inner Domain Is Important for Antibody-Dependent Cellular Cytotoxicity Responses Mediated by Anti-cluster A Antibodies

Previous studies have shown that sera from HIV-1-infected individuals contain antibodies able to mediate antibody-dependent cellular cytotoxicity (ADCC). These antibodies preferentially recognize envelope glycoprotein (Env) epitopes induced upon CD4 binding. Here, we show that a highly conserved tryptophan at position 69 of the gp120 inner domain is important for ADCC mediated by anti-cluster A antibodies and sera from HIV-1-infected individuals.