Ethanol protects the heart against the calcium paradox injury

Rat hearts were depleted of Ca2+ (less than 10(-9) M) for 10 min, followed by 15 min of Ca2+-repletion. The calcium paradox injury occurs during Ca2+-repletion, after a period of calcium depletion. The calcium paradox injury was assessed by percent recovery (hemodynamics, [Ca2+]i, and energy levels) during Ca2+-repletion. A decrease in Na+ concentration during Ca2(+)-depletion did not allow for recovery during Ca2(+)-repletion, however 2.5% and 5% ethanol during Ca2(+)-depletion allowed for an approximate 50% recovery during Ca2(+)-repletion. A combination of ethanol (2.5% or 5%) with a low extracellular Na+ concentration (88 mM) allowed for complete recovery. Ethanol prevented a depletion of diastolic [Ca2+]i during Ca2(+)-depletion, and allowed for a return of normal diastolic [Ca2+]i during Ca2(+)-repletion. Ethanol modulates the activity of the Na+/Ca2+ exchanger and protects against the Ca2(+)-paradox injury.

Two-dimensional programmable optical neural network

A 2-D hybrid optical neural network using a high resolution video monitor as a programmable associative memory is proposed. Experiments and computer simulations of the system have been conducted. The high resolution and large dynamic range of the video monitor enable us to implement a hybrid neural network with more neurons and more accurate operation. The system operates in a high speed asynchronous mode due to the parallel feedback loop. The programmability of the system permits the use of orthogonal projection and multilevel recognition algorithms to increase the robustness and storage capacity of the network.

Phase measurement of a Fourier spectrum by a fringe-scanning phase-conjugate interferometer

We present a novel method for obtaining the phase distribution of an object spectrum by using a fringe-scanning phase-conjugate interferometer. A detailed analysis of the proposed technique is provided, and experimental demonstrations for validating this technique are also given. The major advantages of this method are its potentially high accuracy and its low space-bandwidth-product requirement for the detection system.

High-sensitivity fluorescence detector fluorescein isothiocyanate derivatives of amino acids separated by capillary zone electrophoresis

A fluorescence detector has been developed for capillary zone electrophoresis that produces a ten-fold improvement in precision compared with the previous state-of-the-art in fluorescence detection. This instrument, which is based on a sheath-flow cuvette flow chamber and a 0.05-W argon ion laser beam, combines a high numerical aperture collection optic, N.A = 0.65, with a high quantum yield photomultiplier tube, phi approximately = 0.15 at the wavelength of maximum emission. Detection limits (3 sigma) range from the injection of 1.7 . 10(-21) mol (1.3 . 10(-12) M) of fluorescein isothiocyanate (FITC)-labeled arginine, the best case, to 6 . 10(-21) mol (5.6 . 10(-12) M) of FITC-cysteine, the worse case. Signal linearity extends for at least five orders of magnitude from the detection limit to greater than 10(-16) mol (10(-7) M) injected.

Integrated optical interferometer with a stacked waveguide structure

An integrated optical interferometer consisting of Al(2)O(3) waveguides placed upon an oxidized Si substrate is presented. The two waveguides forming the branches of the interferometer are stacked on top of each other with a SiO(2) buffer layer in between. The interferometer further contains two directional couplers which are realized by bending the upper waveguide toward the lower one. A masked evaporation technique is introduced to fabricate the directional couplers. The operation of the interferometer is confirmed in temperature-sensing experiments while the application of the interferometer to humidity measurement is discussed.

Human antithrombin II (AT3) gene length polymorphism revealed by the polymerase chain reaction

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Grating-encoded multichannel photorefractive incoherent-to-coherent optical conversion

A dynamic multichannel incoherent-to-coherent optical converter based on the photorefractive effect of SBN:Ce is described. A number of grating-encoded input images, illuminated by incoherent light, are projected onto the crystal to yield photoinduced phase gratings. Coherent positive replicas of these images are simultaneously reconstructed by a coherent read beam. A simple theoretical description of this converter and corresponding experimental results are presented.

Effects of perfusion pressure on energy and work of isolated rat hearts

A chemomechanical study of hypertrophied hearts of 6-month-old spontaneously hypertensive rats (SHR) and that of age-matched Wistar-Kyoto (WKY) rats was carried out, analyzing the response of the heart to steady-state changes in coronary perfusion pressure. The ratio of heart (dry)-to-body (wet) weight of WKY rats was 0.37 +/- 0.02 (10(-3] and for SHR was 0.58 +/- 0.03 (10(-3] (p less than 0.01). In the apex-ejecting, isolated, pyruvate-perfused working hearts of WKY rats and SHR, coronary flow was constant when coronary perfusion pressure was set between 140 and 190 cm H2O (range of autoregulation). Coronary flow was perfusion pressure dependent when the coronary perfusion pressure was set below 110 cm H2O for both WKY rats and SHR. Cardiac output, developed pressure, rate of pressure development (dP/dt), and oxygen consumption were constant in the range of autoregulation but decreased in the direction of coronary flow when coronary flow was reduced by a drop in perfusion pressure. Similarly, the phosphorylation potential, phosphocreatine, adenosine triphosphate, and cyclic adenosine monophosphate were constant in the range of autoregulation but decreased directionally with coronary perfusion pressure below 110 cm H2O for both SHR and WKY rats. There was a significantly lower phosphorylation potential in SHR as compared with WKY rats when coronary perfusion pressure was reduced to 80 cm H2O. In the region of autoregulation, coronary flow and oxygen consumption were significantly less in SHR, although developed pressure was significantly greater at both high and low workloads.(ABSTRACT TRUNCATED AT 250 WORDS)

Reversibility of chronic alcohol cardiac depression: 31P magnetic resonance spectroscopy in hamsters

In order to investigate the reversibility of chronic alcohol cardiac depression, hamsters were fed with 50% ethanol for 3 1/2 months, reaching serum alcohol levels of 0.13 +/- 0.11 g/dl (mean +/- SD). Alcohol was then withdrawn for 2 days. Isolated hearts were perfused according to a modified Langendorff method. Energy metabolites were studied using 31P magnetic resonance spectroscopy of isolated perfused hearts standardized by HPLC analysis of freeze-clamped tissue. Total intracellular calcium [Ca2+]i was measured with atomic absorption spectrophotometry, marking the extracellular space in vivo with K(CoEDTA). In alcohol-treated hamster hearts developed pressure was significantly depressed compared to controls. End-diastolic pressure was significantly increased. Coronary flow was not changed, whereas oxygen consumption and high-energy phosphate levels were significantly depressed. Intracellular pH was significantly decreased. [Ca2+]i was significantly increased. Heart weights were significantly lower. After alcohol withdrawal ventricular function, high-energy phosphate levels, and [Ca2+]i were not significantly different from control. The results indicate that chronic alcohol consumption depresses ventricular function and energy levels and also leads to myocardial acidosis. The increase in intracellular calcium likely causes mitochondrial dysfunction. Withdrawal of alcohol is associated with reversibility of functional and energetic cardiac depression.

The human villous cytotrophoblast: interactions with extracellular matrix proteins, endocrine function, and cytoplasmic differentiation in the absence of syncytium formation

Human syncytiotrophoblasts are derived from villous cytotrophoblasts by cell fusion. Coincident with this morphologic transformation, trophoblasts acquire specific endocrine functions, including elaboration of chorionic gonadotropin (hCG). We wondered if syncytia formation was a prerequisite for biochemical differentiation or simply was one part of the differentiation program. By growing purified human cytotrophoblasts under serum-free conditions and manipulating the culture surface, we were able to disassociate morphologic from biochemical differentiation. We have shown previously (Endocrinology 1986, 118:1567) that human cytotrophoblasts grown in the presence of fetal calf serum flatten out, aggregate, and form functional syncytiotrophoblasts in vitro over 24-96 hr. Here we demonstrate that when grown in the absence of serum, the cells do not undergo these morphologic changes, but remain as individual spherical cells. If the culture surface was precoated with fibronectin or a variety of collagens, but not albumin, the cells regained their ability to flatten, aggregate, and form syncytia. Attachment to and syncytia formation on fibronectin was blocked by the addition of the R-G-D-S-containing peptide, Gly-Arg-Gly-Asp-Ser-Pro. Attachment to and syncytia formation on type I collagen was blocked by anti-human fibronectin F(ab')2 fragments, while association with type IV collagen was not affected by this antibody, suggesting that fibronectin mediates trophoblast association with type I collagen, but not type IV. Although syncytia formation did not occur when cytotrophoblasts were cultured under serum-free conditions in the absence of ECM proteins, biochemical differentiation was not affected. These cells secreted hCG at the same rate under serum-free conditions whether they were plated on plastic only--which prevented syncytia formation--or fibronectin, laminin or, type IV collagen--which allowed syncytia formation to occur. Furthermore, cytoplasmic differentiation in the absence of syncytia formation was confirmed by performing transmission electron microscopy on cytotrophoblasts grown under serum-free conditions in the presence of 8-bromo-cAMP. We conclude that syncytia formation is not a prerequisite for biochemical differentiation, but simply part of the trophoblast differentiation program.

Multibeam coupling in photorefractive SBN:Ce

Theoretical and experimental results are presented for simultaneous multibeam coupling in photorefractive SBN:Ce. Within a single crystal, multiple signals are amplified through a coupling process that employs a single pump. The coupling gain of each signal results from coupling both between the pump and the signal and between different signals. The amount of gain that each signal receives is dependent on the intensity of the incident signal; thus a competition for the gain exists among the various signals.

31P and 1H magnetic resonance spectroscopy of acute alcohol cardiac depression in rats

Cardiac depression in the isolated rat heart perfused with 4% ethanol was correlated with intracellular phosphate energetics and tissue water distributions. Energy metabolites were assessed using 31P magnetic resonance spectroscopy (MRS) and correlated to the mitochondrial redox state using epicardial surface fluorometry. Changes in myocardial water compartmentation were measured by using 1H NMR spectroscopy with an extracellular chemical-shift reagent (DyTTHA) and correlated to results of 2D echocardiography (2DE). During alcohol perfusion there was a significant decrease in developed pressure and in coronary flow. No change was seen in ATP, PCr, pHi, Pi, or NADH. After withdrawal of alcohol from the perfusate cardiac function reverted to control values without a depletion of energy levels. During alcohol perfusion 1H MRS showed a marked redistribution of water from the intra- to the extracellular space, corresponding to a 35% left ventricular wall thinning confirmed by 2DE. The results indicate that acute alcohol cardiac depression is related to a dehydration of myocardial cells, but is not associated with intracellular acidosis or energy depletion.

Increased left ventricular diastolic stiffness in the early phase of hereditary cardiomyopathy

Isolated hearts from normal and cardiomyopathic hamsters (160 to 180 days of age) were perfused through the aorta and assessed by echocardiographic and 31P-NMR (nuclear magnetic resonance) techniques. A decreased left ventricular systolic pressure in cardiomyopathic hamsters was associated with diminished cardiac size and left ventricular wall thickness. However, the ratio of inner/outer cross-sectional area and estimated left ventricular volume at any given left ventricular weight was significantly higher, indicating relative left ventricular chamber enlargement in cardiomyopathic hamsters. Left ventricular volumes were increased with an intraventricular balloon. Gradual inflation of the balloon resulted in increments of left ventricular systolic and developed stress that rose to the same values in both groups. At this point, the normalized stress-strain relationship was approximately two times steeper for cardiomyopathic hamsters, while at lower strain values the diastolic stress in cardiomyopathic hamsters was less than in controls, possibly due to cardiac dilatation. Almost the same degree of dilatation was induced in control hearts by the acute addition of 1% alcohol, but it was not followed by increased diastolic stiffness. Examination of hearts by 31P-NMR techniques revealed a decreased phosphocreatine/inorganic phosphate (PCr/Pi) ratio in the cardiomyopathic hamsters that progressed further with balloon inflation and was associated with a relative fall in PCr and adenosine triphosphate (ATP) content. Results suggest increased diastolic stiffness in cardiomyopathic hamsters, which was not seen in acute cardiac depression with alcohol. Diastolic volume overload with increased wall stress is probably the major factor contributing to increased diastolic stiffness early in the cardiomyopathy.

Mechanics and energetics of overstretch: the relationship of altered left ventricular volume to the Frank-Starling mechanism and phosphorylation potential

Isovolumic perfused rat hearts containing an intraventricular balloon were used to assess the effects of incremental balloon volumes on developed pressure, oxygen consumption, coronary flow, phosphorylation potential obtained by P-31 nuclear magnetic resonance, wall thickness obtained by two-dimensional echocardiography, and diastolic wall stress. Three phases in developed pressure were noted: (1) volumes from 0 to 150 microliter resulted in a continuous increase in developed pressure; (2) with volumes from 150 to 250 microliter, developed pressure remained constant whereas developed (systolic) and diastolic wall stress rose sharply; and (3) with volumes from 250 to 400 microliter, developed pressure fell whereas developed (systolic) and diastolic wall stress continued to rise. The ln [(PCr)/(Pi)] was in synchrony with oxygen consumption at 0 and 50 microliter balloon volumes, and then diverged at volumes greater than 100 microliter. Oxygen consumption increased from 0 to 50 microliter, was constant from 50 to 250 microliter balloon volume, and then declined. The ln [(PCr)/(Pi)] fell precipitously at balloon volumes greater than 100 microliter, most likely limited by oxygen consumption. Coronary flow did not change significantly until 250 microliter or more of water was added to the balloon, and then it started to decline. Volumes greater than 100 microliter result in overstretch of myofibers, as observed by the precipitous decline in ln [(PCr)/(Pi)], and the steep increase in diastolic wall stress. With excessive volume loading, the drop in phosphorylation potential, ln [(PCr)/(Pi)], appears to contribute to the decrease in developed pressure.

Reversibility of acute alcohol cardiac depression: 31P NMR in hamsters

Isolated hamster hearts were perfused with 2% ethanol for 30 min and then reequilibrated with control medium. One group of hamsters was pretreated with verapamil. Another group received diltiazem. Myocardial verapamil levels were 9.5 +/- 0.7 mg/g dry wt; diltiazem levels were 22 +/- 7 mg/g dry wt. Energy metabolites were assessed by using 31P NMR standardized with high-pressure liquid chromatography of freeze-clamped tissue. Intracellular calcium was measured by atomic absorption spectrophotometry, marking the extracellular space with K(CoEDTA). After 30 min of perfusion, untreated hamster hearts showed a 74% decrease in developed pressure, a marked increase in end-diastolic pressure, a decrease of ATP from 9.8 to 8.8 mmol, and an increase of Pi from 6.7 to 9.8 mmol, but no change of phosphocreatine (PCr) or intracellular pH (pHi). Verapamil pretreatment partially prevented cardiac depression during alcohol perfusion. Whereas diltiazem had no protective effect. After reequilibration, developed pressure and oxygen consumption significantly exceeded control values. ATP decreased to 8 mmol; pHi, PCr, and Pi showed no significant change. Verapamil-pretreated hearts showed better performance than untreated hearts without change in PCr and Pi, whereas ATP dropped slightly to 8.7 mmol. Thus, functional cardiac depression resulting from acute alcohol exposure is reversible. Increased intracellular calcium levels during alcohol exposure normalized after the removal of alcohol. There was no major change in high-energy phosphates during alcohol exposure or after the removal of alcohol. Verapamil protects the heart from functional depression during alcohol exposure without affecting energy resources.

Chemomechanics of altered perfusion pressure in rat hearts

In an apex-ejecting isolated perfused working rat heart, as well as isovolumic preparations of rat hearts, perfusion pressure was studied independent of afterload. A decrease in perfusion pressure caused an immediate decrease in developed pressure (10s). There was a significant increase in free Pi and the phosphorylation potential after 20-30 min of perfusion at a reduced coronary flow induced by a reduction in perfusion pressure. Developed pressure decreased prior to the phosphorylation potential and inorganic phosphate; however, the phosphorylation set a limit to maximum work performance. At a perfusion pressure of 140 cm H2O and an afterload of 140 cm H2O, work imposed on the heart was maximum; there was no further increase in work.

Effects of altered coronary perfusion pressure on function and metabolism of normal and cardiomyopathic hamster hearts

The effects of a sudden decrease in coronary perfusion pressure from 140 to 0 cmH2O for a 10-second interval were analyzed in normal and cardiomyopathic hamster hearts to determine whether cardiomyopathy would affect the relationship between altered coronary perfusion pressure and left ventricular geometry, wall thickness, myocardial hydrodynamics, and hemodynamics. In normal hamsters, an acute reduction in coronary perfusion pressure resulted in a decrease in left ventricular short axis epicardial cross-sectional area, base to apex length, diastolic wall thickness, myocardial water content and developed pressure. In cardiomyopathic hamsters all results induced by lowering the hydrostatic pressure of the perfusing medium were the same except that diastolic wall thickness failed to decline, indicating a decrease in intramyocardial elasticity in dilated cardiomyopathy. In parallel studies, hearts were freeze clamped at end-diastole and high energy phosphates and energy metabolites analyzed. In both normal and cardiomyopathic hamsters no significant changes were observed in ATP, PCr, or Pi levels at 10 s following the decrease in perfusion pressure. However, during the abrupt decrease in coronary perfusion pressure adenosine increased and cAMP decreased in both groups of animals. The erectile effect of altered coronary perfusion pressure is partially attenuated in the cardiomyopathic hamster in which no change in diastolic wall thickness occurs during an abrupt change in the hydrodynamics of the heart.

Influence of heart rate on metabolic and hemodynamic parameters in the Syrian hamster cardiomyopathy

The effect of varying heart rate in 155- to 170-day-old isolated, perfused cardiomyopathic Syrian hamster hearts was evaluated by 31P nuclear magnetic resonance spectroscopy. At a low paced heart rate of 170 bpm, cardiomyopathic hearts did not differ from normal hearts except for a lower developed left ventricular pressure. As pacing rate was increased progressively to 270/min, cardiomyopathic hearts showed prolongation of contraction, which led to a pronounced rise in diastolic pressure as the interstimulus interval shortened. This was accompanied by a marked decrease in energy-rich phosphorus compounds. By contrast, increasing heart rate in normal hearts did not change left ventricular pressure and caused only a mild reduction in energy-rich phosphorus compounds. Intracellular pH of cardiomyopathic animals paced at 270 bpm was significantly lower than in normal animals. Thus, indices reflecting mitochondrial function of 155- to 170-day-old cardiomyopathic hamsters appear adequate at low heart rate. Increasing the heart rate unmasks latent mitochondrial dysfunction.

Cytogenetic analysis in workers occupationally exposed to nickel carbonyl

Chromosomal aberration and sister-chromatid exchange (SCE) base-line frequencies and SCE frequencies induced by 10 ng/ml mitomycin C (MMC) were analysed in cultured peripheral lymphocytes of 65 workers occupationally exposed to nickel carbonyl Ni(CO)4. The subjects were divided into 4 groups: (1) control; (2) exposed to nickel carbonyl (= exposed); (3) cigarette smokers; (4) smoking-exposed. The results show that there are no significant differences in chromosomal aberration frequencies, breaks or gaps, between the various groups. However, the SCE base-line frequency of the smoking-exposed group, with an average of 7.7/cell, was significantly higher than that of the control group, with an average of 6.5/cell (P less than 0.01), and also than that of the exposed group with an average of 5.9/cell (P less than 0.01). Similarly, the SCE frequency induced by 10 ng/ml MMC in the smoking-exposed group which averaged 15.5/cell was significantly higher than that of the control group (average of 13.2/cell (P less than 0.05], and also than that of the exposed group with an average of 12.3/cell (P less than 0.01). Under our experimental conditions, it may be that the level of exposure was not high enough to elicit an increase in chromosomal aberrations and SCE frequencies in the non-smoker exposed group. The fact that an increase in SCE frequencies was only found in the smoking-exposed group implies that the two factors, smoking and exposure to nickel carbonyl, are jointly responsible for the result.

Protein analysis of HLA-DR2.3 haplotype

The human major histocompatibility antigens (HLA-DR, HLA-DQ, and HLA-DP), consisting of alpha and beta chains, show extensive polymorphism. Based on differences of T-cell responses, the serologically defined DR2 specificity has been divided into Dw2, Dw12, and several putative additional "Dw subtype" specificities (AZH, FJO, and MN2, which we shall designate as "DR2.3", and LD-5a). To investigate the relationships of these specificities, DR and DQ molecules were analyzed by two-dimensional gel electrophoresis (2D-PAGE). The 2D-PAGE patterns of the DR molecules are identical among DR2.3 cells. Three DR beta chain polypeptides are expressed on DR2.3 cells. The electrophoretic mobilities of two of these beta chains are different from those of beta chains from the Dw2 and Dw12 cells. The DR molecules of the LD-5a cells show similar 2D-PAGE patterns with those of DR2.3 cells. The 2D-PAGE patterns of DQ molecules are identical among DR2.3 cells. The electrophoretic mobilities of DQ beta chains are different for Dw2, Dw12, LD-5a, and DR2.3 cells. These results indicate that the AZH, FJO, and MN2 cells have identical or very similar DR and DQ molecules and constitute a third, and relatively homogeneous, subgroup ("DR2.3") of the DR2 specificity. In addition, DR2.3 cells have a unique characteristic in that they express three DR beta chains.

The preventive effect of verapamil on ethanol-induced cardiac depression: phosphorus-31 nuclear magnetic resonance and high-pressure liquid chromatographic studies of hamsters

Alcoholic depression of left ventricular function was produced in normal hamsters by the administration of increasing concentrations of alcohol in drinking water (up to 50%) for 6 months. The result was assessed by phosphorus-31 nuclear magnetic resonance of isolated perfused hearts and high-pressure liquid chromatography of freeze-clamped tissues. Hemodynamic data and myocardial oxygen consumption were also monitored. Alcoholic hamsters had significantly higher inorganic phosphate and lower ATP levels, while maintaining normal intracellular pH, phosphocreatine, and creatine. Although coronary flow and oxygen consumption were maintained at normal levels, hamsters ingesting 50% ethanol had significantly lower left ventricular developed pressure and dP/dt. Treatment with verapamil during long-term ethanol consumption prevented the development of these metabolic and functional abnormalities. It is hypothesized that alcohol produces membrane abnormalities leading to adverse ion flux, and that these are largely prevented by concurrent administration of verapamil.

The three-dimensional structure of trichosanthin molecule

A model completed recently of two trichosanthin molecules in an asymmetric unit belonging to the monoclinic system is reported. It can be seen that the molecular structure consists of two domains, one large and one small, and that there are some features in the secondary structure. The dissimilarity between two molecules as well as their interactions in an independent unit correlated in a non-symmetric way has been described, moreover, the binding sites of the heavyatom position in the derivatives are also discussed.

Polymorphism of human Ia antigens generated by reciprocal intergenic exchange between two DR beta loci

Class II molecules encoded by the human major histocompatibility complex (MHC) are involved in regulating T-cell response to antigens. The mechanisms for generating polymorphism in products of the MHC have been studied extensively for both the murine H-2 and the human HLA complex. Such studies indicate that point mutations plus selection have a major role in the generation of polymorphisms of class I and class II MHC genes. However, a non-reciprocal gene conversion mechanism has been proposed to explain several examples of clustered sequence variation in MHC genes. In all these examples, the proposed gene conversion event is unidirectional; that is, one of the two interacting genes acts as sequence donor and the other as sequence recipient. No examples of potential reciprocal genetic exchange (as occurs in the fungal system), in which the two interacting genes act as both donor and recipient of gene fragments, have been found in the MHC system or in other multigene families of higher organisms. We sequenced two different HLA-DR beta complementary DNAs from each of two different cells all expressing the same serologically defined determinant (DR2) but different T-cell-recognized (Dw) specificities (Dw12 and MN2). Sequence comparisons of these four cDNA clones (and two DR beta amino-acid sequences from the DR2-Dw2 subtype) suggest that new coding sequences for DR beta molecules in the DR2 haplotypes are potentially generated by reciprocal intergenic exchange.

Ileal hyperplastic response to starvation in the rat

The ability to respond to changes in the external and internal environments is a fundamental characteristic of intestinal structure and function. We compared the responses of the rat proximal and distal small intestine to the stresses of fasting and refeeding in the rat. In the duodenum, 3 days of starvation caused villus and crypt hypoplasia, reduced incorporation of [3H]thymidine into crypt cells, decreased cell migration rate on the villus, and lowered specific and total activities of several cellular enzymes. These changes were reversed by 1 day of refeeding. In contrast, mucosal hypoplasia did not occur in the ileum during fasting, and the specific activities of the disaccharidases were increased after 3 days of starvation. However, ileal [3H]thymidine incorporation, thymidine kinase activity, and ornithine decarboxylase activity decreased during starvation. These effects were also reversed by refeeding. The results of these studies illustrate differing responses for the proximal and distal small intestine and suggest the presence of distinctly differing mechanisms for the control of their mucosal mass and enzyme activities.

Corticosteroid therapy in Epstein-Barr virus infection. Effect on lymphocyte class, subset, and response to early antigen

Corticosteroid treatment of impending upper airway obstruction due to Epstein-Barr virus (EBV) infectious mononucleosis did not alter the pattern of lymphocyte changes induced by this viral infection during the first two weeks following administration of prednisone. By 12 weeks, 11 treated students had significantly fewer lymphocytes, including B, total T, helper, and T-suppressor cell numbers, than 11 untreated EBV-infected students, and values were closer to those noted in uninfected controls. Corticosteroid therapy did not alter the serologic response to early antigens of EBV. Fever and lymphadenopathy resolved somewhat more quickly in treated students.

Syngeneic responses by murine thymocytes: a role for non-MHC and non-MLS genes

A subpopulation of thymocytes from adult mice that is nonadherent to macrophage monolayers showed dramatically increased syngeneic mixed leukocyte responses (SMLR). Cloned cells were derived by limiting dilution from these SMLR-primed BALB/c thymocytes and were maintained and subcloned by repeated stimulation with syngeneic BALB/c spleen cells without the addition of exogenous interleukins. The cloned thymocytes were tested for their reactivities against H-2- and Mls-identical BALB/c and B10.D2 spleen cells (H-2d, Mlsb). We found that BALB/c and B10.D2 stimulator cells differed significantly in their capacity to restimulate the cloned BALB/c thymocytes. In addition, polyclonal syngeneic mixed leukocyte cultures (SMLC) of BALB/c thymocytes also showed differential restimulation by BALB/c and B10.D2 stimulators. Taken together, our data indicate a role for the product(s) specified by non-MHC and non-Mls gene(s) in the autorecognition by thymocytes.

Syngeneic responses by murine thymocytes: a role for non-MHC and non-MLS genes

A subpopulation of thymocytes from adult mice that is nonadherent to macrophage monolayers showed dramatically increased syngeneic mixed leukocyte responses (SMLR). Cloned cells were derived by limiting dilution from these SMLR-primed BALB/c thymocytes and were maintained and subcloned by repeated stimulation with syngeneic BALB/c spleen cells without the addition of exogenous interleukins. The cloned thymocytes were tested for their reactivities against H-2- and Mls-identical BALB/c and B10.D2 spleen cells (H-2d, Mlsb). We found that BALB/c and B10.D2 stimulator cells differed significantly in their capacity to restimulate the cloned BALB/c thymocytes. In addition, polyclonal syngeneic mixed leukocyte cultures (SMLC) of BALB/c thymocytes also showed differential restimulation by BALB/c and B10.D2 stimulators. Taken together, our data indicate a role for the product(s) specified by non-MHC and non-Mls gene(s) in the autorecognition by thymocytes.

Studies on derivatives of 2,3-dihydro-4H-1,3,2-benzoxazaphosphorine. Synthesis and structure analysis of 2,3-disubstituted-2,3-dihydro-4H-1,3,2-benzoxazaphosphorin-4-one -(thio ne)-2-sulfide(oxide)

A series of novel organocyclophosphorus compounds including twenty-three 2,3-disubstituted-2,3-dihydro-4H-1,3,2-benzoxazaphosphorin-4-one-2 -sulfide (compounds I) and three 2,3-disubstituted-2,3-dihydro-4H-1,3,2-benzoxazaphosphorin-4-th ion e-2-oxide (compounds II) have been synthesized. Their structures were determined by IR, UV, 1HNMR, X-ray diffraction and elemental analysis. Each of compounds I showed a strong absorption between 1290-1319 cm-1 in the IR spectrum. Comprehensive studies of the spectral data and experimental results indicated that this strong characteristic absorption is different from that of the P = O linkage and thus could be considered as a result of the stretching vibration of (unsaturated C)-N single bond. In the course of synthesis of the compounds, an abnormal product (Formula: see text) is frequently formed as an isomer of the expected product I (Formula: see text). However, by suitable choice of condensation conditions, either of the isomers could be made predominantly in yield and be readily isolated from the other by recrystallizing for several times from appropriate solvent. Data for the melting point, IR, UV and 1HNMR spectra of three pairs of the isomers are given, and primary analyses of the spectra are made as well.

Thymocyte and macrophage interactions: separation of murine thymocyte subsets and enrichment of syngeneic cell-responding thymocytes by adsorption to macrophage monolayers

The spontaneous binding of murine thymocytes to macrophage monolayers was employed to separate thymocytes into macrophage-unbound and -bound subsets, and the functional reactivities of these two subpopulations were examined. Macrophage-unbound thymocytes were found to be enriched in functional subsets reactive to semi-allogeneic and allogeneic stimulating spleen cells by proliferation in mixed leukocyte culture (MLC). Furthermore, macrophage-unbound thymocytes were frequently found to respond to syngeneic spleen cells. This syngeneic proliferative response showed both memory and specificity upon subsequent restimulation and thus seems to represent a syngeneic mixed leukocyte reaction (SMLR). Syngeneic responding thymocytes were also found to produce interleukin 2 when cultured with syngeneic but not allogeneic stimulator cells. In contrast, macrophage-bound thymocytes showed greatly reduced proliferative responses to allogeneic stimulators and no responses to syngeneic stimulators. The macrophage-bound thymocyte subset was not enriched in detectable suppressive activity; proliferative responses of macrophage-unbound thymocytes to either allogeneic or syngeneic cells were neither suppressed nor enhanced when macrophage-unbound thymocytes were added to the cultures. Thus, the macrophage-unbound subset seems to be enriched in functionally mature thymocytes and the macrophage-bound subset appears to be enriched in functionally immature thymocytes. This functional separation of thymocytes by macrophage adherence also correlated well with thymocyte subpopulations separated by bovine serum albumin density gradients; the low density mature thymocytes showed enhanced responses to both allogeneic and syngeneic stimulators, whereas the high density immature cells were unresponsive. This correlation was supported further by binding studies in which T cell tumor lines derived from C57BL/6 mice were used. ERLD tumor cells, which are similar to cortical immature thymocytes in both enzymatic and surface antigenic markers, were found to bind readily to macrophages, whereas both EL-4 and E male G2 tumor cells, with characteristics of mature thymocytes, bound to macrophages poorly. The binding of thymocytes and ERLD tumor cells to macrophages was not genetically restricted. We speculate that thymocyte binding to macrophages may play a critical role during the functional maturation of thymocytes.

Thymocyte and macrophage interactions: separation of murine thymocyte subsets and enrichment of syngeneic cell-responding thymocytes by adsorption to macrophage monolayers

The spontaneous binding of murine thymocytes to macrophage monolayers was employed to separate thymocytes into macrophage-unbound and -bound subsets, and the functional reactivities of these two subpopulations were examined. Macrophage-unbound thymocytes were found to be enriched in functional subsets reactive to semi-allogeneic and allogeneic stimulating spleen cells by proliferation in mixed leukocyte culture (MLC). Furthermore, macrophage-unbound thymocytes were frequently found to respond to syngeneic spleen cells. This syngeneic proliferative response showed both memory and specificity upon subsequent restimulation and thus seems to represent a syngeneic mixed leukocyte reaction (SMLR). Syngeneic responding thymocytes were also found to produce interleukin 2 when cultured with syngeneic but not allogeneic stimulator cells. In contrast, macrophage-bound thymocytes showed greatly reduced proliferative responses to allogeneic stimulators and no responses to syngeneic stimulators. The macrophage-bound thymocyte subset was not enriched in detectable suppressive activity; proliferative responses of macrophage-unbound thymocytes to either allogeneic or syngeneic cells were neither suppressed nor enhanced when macrophage-unbound thymocytes were added to the cultures. Thus, the macrophage-unbound subset seems to be enriched in functionally mature thymocytes and the macrophage-bound subset appears to be enriched in functionally immature thymocytes. This functional separation of thymocytes by macrophage adherence also correlated well with thymocyte subpopulations separated by bovine serum albumin density gradients; the low density mature thymocytes showed enhanced responses to both allogeneic and syngeneic stimulators, whereas the high density immature cells were unresponsive. This correlation was supported further by binding studies in which T cell tumor lines derived from C57BL/6 mice were used. ERLD tumor cells, which are similar to cortical immature thymocytes in both enzymatic and surface antigenic markers, were found to bind readily to macrophages, whereas both EL-4 and E male G2 tumor cells, with characteristics of mature thymocytes, bound to macrophages poorly. The binding of thymocytes and ERLD tumor cells to macrophages was not genetically restricted. We speculate that thymocyte binding to macrophages may play a critical role during the functional maturation of thymocytes.

Managing families of the demented elderly

Dementing illness affects about 10 percent of people over 65 years of age, and families encounter many problems as they attempt to care for these relatives. Physicians can assist in several ways, beginning with establishing an accurate diagnosis, as terms such as "senility," "dementia," and "hardening of the arteries" are imprecise and may convey an attitude of hopelessness. A psychiatric, medical, and laboratory evaluation usually leads to a specific diagnosis. About one half of all cases are due to Alzheimer's disease, but there is frequently a treatable component to the demented patient's condition. In addition to making an accurate diagnosis and treating reversible problems, physicians can assist the family in having the patient do all he or she is capable of including increasing specific activities, can help the family understand that even their best efforts may not lead to improvement, can point out ways for the family to balance the patient's needs with their own, and can teach the family how to communicate more effectively with the patient.

Cognitive correlates of diffuse cerebral atrophy determined by computed tomography

The relationship between severity of diffuse cerebral atrophy determined by computed tomography (CT) and severity of cognitive impairment was examined in 55 men, 50 to 77 years old. Partial correlations, controlling for the effects of age and education, indicated that increased cerebral atrophy was associated with decline in orientation, recent memory, and general level of intellectual functioning. Correlations between degree of atrophy and decline in immediate and remote memory were not significant. Despite significant associations between cerebral atrophy and some aspects of intellectual functioning, considerable variance in performance on cognitive tasks was not explained by cerebral atrophy. Therefore, the degree of diffuse cortical and central atrophy observed on CT scan did not closely predict the degree of cognitive dysfunction, nor did the observation of cerebral atrophy necessarily indicate the presence of dementia.

Early detection and specificity analysis of human cytolytic T lymphocyte (CTL) colonies generated in soft agarose culture: a potential assay for definition of CTL defined (CD) determinants

In this communication we describe and early, large-scale screening assay for the detection of colonies with varied cytolytic specificity. The colonies are generated in soft agarose culture from day 3 mixed lymphocyte culture (MLC) alloactivated cells. A cell mediated lympholysis (CML) assay utilizing as few as 500 target cells has made it possible to prescreen for cytolytic T lymphocyte (CTL) colonies and to test for antigen specificities as early as 11 and 14 days, respectively, after MLC priming. Large numbers of colonies, from 80 to over 150, have been prescreened against a specific sensitizing target cell, and as many as 30 CTL colonies have been simultaneously tested against a panel of multiple targets carrying defined HLA-A, -B, -C, -DR antigens to evaluate antigen specificity. All CTL colonies are lytic against the specific sensitizing target cell and do not lyse the target autologous to the responder. Some are found to be operationally specific in that they lyse only those target cells which share HLA serologically defined (SD) antigens with the sensitizing cells, and other show cytolytic patterns which are not correlated with known HLA-SD antigens. These observations support, at a much finer level of analysis, the possible distinction between SD and CTL defined (CD) determinants.