Analysis and purification of phosphorylated isoprenoids by reversed-phase HPLC

Procedures were developed for analysis and purification of phosphorylated isoprenoids by reversed-phase HPLC. Dimethylallyl diphosphate (C5), geranyl diphosphate (C10), farnesyl diphosphate (C15), geranylgeranyl diphosphate (C20), and farnesylgeranyl diphosphate (C25) were cleanly separated on a C18 column by gradient elution with acetonitrile and 25 mM NH4HCO3. Reversed-phase HPLC was used to directly analyze extracts for phosphorylated isoprenoids and to follow the progress of enzyme-catalyzed reactions without having to hydrolyze the phosphate esters before analysis. Examples are provided for geranylgeranyl diphosphate synthase, geranylgeranylglyceryl phosphate synthase, and squalene synthase. The separations were run on preparative scales to purify products from the enzymatic reactions for mass spectrometry and to purify synthetic substrates.

LDL subclass phenotypes and the insulin resistance syndrome in women

BACKGROUND

Low-density lipoprotein (LDL) subclass phenotype B, characterized by predominance of small, dense LDL particles, is associated with elevated plasma triglycerides and apolipoprotein B and with lower high-density lipoprotein (HDL) cholesterol and apolipoprotein A-I. Because these abnormalities resemble the dyslipidemia of insulin resistance, we examined associations of LDL subclass phenotype with plasma insulin levels and with other aspects of the insulin resistance syndrome.

METHODS AND RESULTS

LDL subclass phenotypes were determined by gradient gel electrophoresis in 682 female twins aged 30 to 91 years who participated in the second examination of the Kaiser Permanente Women Twins Study. Prevalence of phenotype B and the intermediate phenotype (I) increased strongly with age, obesity, and non-insulin-dependent diabetes. In multivariate analysis of nondiabetic women, phenotype B or I was independently associated with each aspect of the insulin resistance syndrome, including higher plasma triglycerides, waist-hip ratio, fasting and postload insulin levels, and systolic blood pressure and lower HDL cholesterol levels after adjustment for age and body mass index. The prevalence of phenotype B or I rose progressively from 5.6% in women with no manifestations of the insulin resistance syndrome to 100% in women with four syndrome components. In 25 nondiabetic, monozygotic twin pairs discordant for subclass phenotype, the twins with phenotype B (or I) had significantly higher levels of body mass index, waist-hip ratio, and systolic blood pressure than their twins with phenotype A. Thus, nongenetic variation in these risk factors is important in explaining their associations with LDL subclass phenotype.

CONCLUSIONS

Small, dense LDL is an integral feature of the insulin resistance syndrome. Nongenetic (ie, behavioral or environmental) factors are important for the expression of the phenotype and for its association with other heart disease risk factors.

Calsequestrinlike calcium-binding protein is expressed in calcium-accumulating cells of Pistia stratiotes

To contend with high calcium (Ca) levels in the environment, many plant species contain crystal idioblasts, specialized cells which accumulate large amounts of Ca as oxalate crystals. The biochemical processes involved in the accumulation of Ca in crystal idioblasts are unknown, as these cells constitute only a minor proportion of the total plant tissue. To address how crystal idioblasts buffer cytosolic Ca during crystal formation, we purified these cells from water lettuce and assessed their biochemistry. We show here that crystal idioblast cells contain three Ca-binding proteins not detectable in mesophyll cells. One of the Ca-binding proteins shares antigenicity with rabbit calsequestrin, a high-capacity low-affinity Ca-binding protein, and is encoded by related nucleotide sequences. Immunocytochemical localization studies further demonstrate that a calsequestrinlike protein is present primarily in crystal idioblasts and is preferentially localized in the endoplasmic reticulum, an organelle enriched in Ca as evidenced by vital staining. We thus conclude that crystal idioblasts possess a buffering system involving calsequestrinlike proteins, a process that likely plays an essential role in the bulk control of Ca in plant cells.

Yeast squalene synthase: expression, purification, and characterization of soluble recombinant enzyme

Squalene synthase is the first pathway-specific enzyme in the cholesterol biosynthetic pathway. The gene (ERG9) encoding squalene synthase in Saccharomyces cerevisiae has been isolated and characterized (S. M. Jennings, Y. H. Tsay, T. M. Fisch, and G. W. Robinson, 1991, Proc. Natl. Acad. Sci. USA 88, 6038-6042: M. Fegueur, L. Richard, A. D. Charles, F. Karst, 1991, Curr. Genet. 20, 365-372). The structural gene for the enzyme was modified by the polymerase chain reaction to remove a hydrophobic C-terminal domain, and the open reading frame for the truncated protein was cloned into yeast and Escherichia coli expression vectors. In E. coli, overexpressed truncated squalene synthase was soluble and constituted 2-5% of total cellular protein. The recombinant enzyme was purified to > 95% homogeneity in two steps by chromatography on hydroxyapatite and phenyl-Superose. Soluble truncated squalene synthase is monomeric and catalyzes the two-step conversion of farnesyl diphosphate (FPP) to squalene via presqualene diphosphate in the presence of Mg2+ and NADPH. The concentration of FPP needed for half-maximal activity was 40 microM. At higher concentrations, FPP was an inhibitor. The activity of squalene synthase was stimulated by detergents and reached a maximal value of kcat = 3.3 s-1 at 100 microM FPP in the presence of 1% (v/v) Tween 80.

Research note: responses of laying hens on saline drinking water to dietary supplementation with various zinc compounds

Production variables, eggshell defects, eggshell quality, the concentration of calcium-binding protein (CaBP), and the activity of carbonic anhydrase (CA) in the shell gland mucosa were determined in hens receiving town water (10 mg Na/L), or town water supplemented with 2 g NaCl/L (796 mg Na/L). Five treatments were examined. Control hens received town water and a proprietary layer mash containing .17% Na. The remaining four treatments received the water containing NaCl (2 g/L). Hens of Treatment 2 were fed the proprietary layer mash and those of Treatments 3, 4, and 5 received, respectively, the layer mash containing supplements of Zn-methionine (Zinpro-200; .5 g/kg), Zn sulfate (ZnSO4.7H2O; .46 g/kg), or chelated Zn-EDTA (.54 g/kg) to supply the same concentration of Zn (.1 g/kg). The treatments were applied for 6 wk. Hens receiving the saline drinking water without any dietary Zn supplement produced significantly (P < .05) more eggs with shell defects than hens receiving the town water. This increase in the incidence of eggshell defects was associated with significant reductions in eggshell breaking strength, the concentration of CaBP, and the activity of CA. Supplementing the saline drinking water with any of the three Zn compounds significantly reduced the incidence of eggshell defects and in some cases improved shell breaking strength, the concentration of CaBP, and the activity of CA.

Clinical and experimental studies of JPYS in reducing side-effects of chemotherapy in late-stage gastric cancer

This article reports a research project undertaken for more than 16 years by the Cancer Department of Guang An Men Hospital. Tonic Jian Pi Yi Shen (JPYS), which nourishes the spleen and kidney, was used in combination with chemotherapy in the treatment of late stage gastric cancer patients for the purpose of promoting completion of the chemotherapeutic course, improving the general condition, ameliorating the reaction in the digestive system, protecting hemopoiesis and strengthening immunocompetence. The results of lab experiments were found to coincide with those of clinical application.

Effect of temperature and coronary flow on the metabolic and mechanical function of the isolated rat heart

A number of cardiac metabolic intermediates, namely, adenosine triphosphate (ATP), H+, phosphocreatine (PCr), inorganic phosphate (Pi), adenosine diphosphate (ADP), and related functions of these intermediates, Gibbs' free energy of ATP hydrolysis (delta G) and phosphorylation ratio [ATP/(ADP.Pi)], are thought to adjust mitochondrial oxidative phosphorylation rates to conform to mechanical demand. The effects of hypothermia and altered perfusion pressure on these parameters were evaluated in 12 hearts from Sprague-Dawley rats perfused in the Langendorff mode. 31P-nuclear magnetic resonance (NMR) spectra were obtained at cardiac temperatures between 20 and 37 degrees C, and coronary perfusion pressures between 20 and 145 cm H2O. Coronary flow varied between 0.5 and 15 ml/min throughout this range of intervention. Heart rate (HR), left ventricular systolic pressure (LVSP), and specific volumetric coronary flow (SCF) were determined for each temperature and perfusion pressure. The product HR x LVSP directly correlated with perfusion pressure at all temperatures. The temperature dependence could be represented by an overall activation energy of 72.7 kJ/M. In the constant temperature experiment, SCF and HR x LVSP fell linearly with decreasing perfusion pressure. Quantitative evaluation of the relationship between cardiac function and the metabolic intermediates described above defined these intermediates as nonregulatory with the possible exception of H+.

Blockade of NMDA receptor-mediated mobilization of intracellular Ca2+ prevents neurotoxicity

NMDA receptor activation leads to elevated Ca2+ in cultured rat cortical and retinal ganglion cell neurons. If excessive, this Ca2+ response is associated with delayed neurotoxicity. We used dantrolene and ionomycin to test if the Ca2+ response to NMDA was due to mobilization of intracellular Ca2+ stores rather than merely to Ca2+ influx. In the presence of EGTA, ionomycin resulted in release and subsequent depletion of intracellular Ca2+ stores. Henceforth, despite normal extracellular Ca2+, NMDA elicited only about half of its former Ca2+ response. Similarly, when dantrolene was used to block Ca2+ release from intracellular stores, we observed > 50% smaller NMDA-evoked Ca2+ responses. These results quite surprisingly indicate that at least half the Ca2+ response to NMDA is due to release of intracellular Ca2+, a process triggered by influx of extracellular Ca2+. Dantrolene also protected neurons from NMDA receptor-mediated neurotoxicity. Release of intracellular Ca2+ may therefore be a necessary step in the cascade leading to neuronal damage induced by excessive NMDA receptor stimulation and may be amenable to pharmacological intervention.

Heterozygosity of the major histocompatibility complex controls the autoimmune disease in (NZW x BXSB) F1 mice

In the F1 hybrid of phenotypically normal NZW (H-2z) and systemic lupus erythematosus (SLE)-prone BXSB mice (H-2b), features of the disease became more severe than those seen in the BXSB mice, regardless of the presence or absence of the Yaa (Y-chromosome-linked autoimmune acceleration) mutant gene. To determine whether the gene(s) linked to the major histocompatibility complex (MHC) of NZW mice is involved in this event, we developed the H-2-congenic NZW.H-2d strain and compared the severity of autoimmune disease between (NZW x BXSB) F1 (H-2z/b) and (NZW.H-2d x BXSB) F1 mice (H-2d/b). The H-2z/b, but not H-2d/b, heterozygous F1 mice of both sexes showed an accelerated, higher incidence of proteinuria and a more severe thrombocytopenia than did the BXSB mice. In NZW x (NZW x BXSB) F1 backcross mice, the H-2z/b heterozygous progeny showed more severe disease than did the H-2z/z homozygotes. Thus, disease-accelerating events in (NZW x BXSB) F1 mice are linked to the H-2z/b heterozygosity. Because H-2d/z heterozygosity plays a crucial role for SLE in (NZB x NZW) F1 mice, in which SLE features differ from those in (NZW x BXSB) F1 mice, the present observations may imply that the different but related MHC heterozygosity acts as a predisposing genetic element in these different SLE syndromes.

Calcium and carbonate supply in the shell gland of hens laying eggs with strong and weak shells and during and after a rest from lay

The concentration of calcium-binding protein (CaBP) and the activities of calcium adenosine triphosphatase (Ca(2+)-ATPase) and carbonic anhydrase (CA) were determined in the shell gland mucosa of hens in two experiments. In Experiment 1, laying hens on a proprietary layer mash were compared with hens rested from lay by the feeding of whole grain barley. In Experiment 2 comparisons were made of laying hens fed the proprietary layer mash and producing eggs with either strong or weak shells. These latter comparisons were also made when the shell gland was quiescent or active with respect to daily eggshell formation. Feeding whole grain barley reduced egg production to zero after 11 days. This reduction in rate of lay was accompanied by significant reductions in all three markers, the effect on Ca(2+)-ATPase and CaBP being less than for CA. Control values were regained between 10 and 16 days after the barley was replaced with the layer mash. Relative shell strength and the physiological status of the shell gland with respect to time of daily eggshell formation had no significant effect on any marker in Experiment 2.

Colocalization of enkephalin-, glucagon-, and corticotropin-releasing factor-like immunoreactivity in GABAergic amacrine cells in turtle retina

The large number of amacrine cells which contain gamma-aminobutyric acid (GABA) in the turtle retina makes it difficult to examine specific GABAergic cell types. In order to selectively label subpopulations of GABAergic neurons, we have used fluorescent double-labeling immunocytochemical techniques to examine the localization of GABA-like immunoreactivity (LI) in amacrine cells which contain antigens resembling the neuropeptides glucagon (GLUC), corticotropin-releasing factor (CRF) or enkephalin (ENK). GABA-LI was found in 41% of the cells with GLUC-, 100% of the cells with CRF-, and 69% of the cells with ENK-LI. There were regional differences in the presence of GABA-LI in amacrine cell populations with ENK-LI. GABA-LI was present in about 80% of the cells with ENK-LI outside of the visual streak, while only 37% of the cells within the streak had GABA-LI. Based on the distinct morphologies and regional distributions of these peptidergic amacrine cells, we conclude that they represent different subpopulations of GABAergic amacrine cells in the turtle retina. Future studies can now utilize existing information regarding the synaptic connectivity of these peptidergic amacrine cells to help delineate the functions of GABAergic amacrine cells in the turtle retina.

Glutamate-immunoreactive terminals synapse on primate spinothalamic tract cells

Glutamate has been shown to excite spinothalamic tract (STT) neurons and has been localized to primary afferent neurons, spinal cord projection neurons, and interneurons in the spinal cord dorsal horn. The likelihood that glutamate-immunoreactive (GLU-IR) terminals directly innervate STT neurons was investigated. For these studies three lamina IV or V STT cells in the lumbar spinal cords of three monkeys (Macaca fascicularis) were identified electrophysiologically and characterized. Two were identified as high threshold neurons and one as a wide dynamic range neuron. Following intracellular injection of the cells with HRP and reaction to give the cells a Golgi-like appearance, the tissues were processed for electron microscopy. Postembedding immunogold methods with antibodies specific for glutamate were used to identify GLU-IR terminals apposing the somata and dendrites of the STT neurons, including dendrites that extended into laminae IV and III. The GLU-IR terminals were numerous and constituted a mean of 46% of the population counted that appose the STT soma and 50% of the profiles apposing the dendrites. Fifty-four percent of the somatic and 50% of the dendritic surface length was contacted by GLU-IR terminals. Most terminals contained round clear vesicles and some contained a variable number of large dense core vesicles. For one of the three cells examined it was determined that 45% of the terminals apposing the soma were GLU-IR and 30% of the terminals were gamma aminobutyric acid-immunoreactive (GABA-IR). In an additional monkey, a lamina I cell retrogradely labeled from the ventral posterolateral nucleus of the thalamus was found to be ensheathed in glial processes.(ABSTRACT TRUNCATED AT 250 WORDS)

Optical thresholding and maximum operations

Self-oscillations in nonlinear optical four-wave mixing and resonators are considered. Some unique properties of these oscillations can be employed for implementing parallel optical thresholding, comparing, and maximum operations. Both theoretical and experimental results that are obtained by utilizing the photorefractive nonlinearity are presented and discussed.

The purification of nucleoside diphosphate kinase from rat brain

Nucleoside diphosphate kinase from the cytosol of rat brain was purified to electrophoretic homogeneity through a series of chromatography columns, including DE-52, AcA-34 Ultrogel, phenyl-Sepharose and Q-Sepharose. The molecular weight of the enzyme was 64,000 as estimated by gel filtration, and it consisted of 3 identical 19,000 subunits. [35S]-GTP gamma S binding and autophosphorylation of the enzyme, and inhibition of the GTPase activity of G-protein were used to screen for the enzyme. These methods were shown to be useful for purifying and assaying the enzyme.

[The experimental research on the changes in the amount of prostaglandins in rat alveolar bone during tooth movement]

In this paper, the author observed that in different time the changes of the amount of endogenous prostaglandins in rat alveolar bone under continuous orthodontic force, and confirmed that there are certain amount of PGE1. PGE2 in the rat alveolar bone even without orthodontic force, and the amount is no difference between right and left side. After several hours when the orthodontic force was applied the amount of PGE1 and PGE2 in rat alveolar bone rose significantly. But it is transient and does not last 24 hours.

GABA-immunoreactive terminals synapse on primate spinothalamic tract cells

Gamma-aminobutyric acid (GABA) is a putative inhibitory neurotransmitter in the vertebrate nervous system. Several lines of evidence suggest that GABA plays an important role in the processing and modulation of sensory input in the spinal cord dorsal horn. In the present study, the relationship between GABA-immunoreactive (GABA-IR) terminals and spinothalamic tract (STT) cells in the monkey lumbar cord was investigated. Physiologically characterized STT cells, one located in lamina V and two located in lateral lamina IV, were intracellularly injected with horseradish peroxidase (HRP). A fourth STT cell, located in lamina I, was retrogradely labeled following injection of HRP into the contralateral thalamus. Immunogold labeling of ultrathin sections through the cell bodies and proximal dendrites of the STT neurons demonstrated that the percentage of the GABA-IR terminals in contact with these profiles was 24.7% and 36%, respectively. The average STT surface length contacted by GABA-IR terminals for cell bodies and proximal dendrites was 18.2% and 26.7%, respectively. For the lamina I cell, 7 out of 35 (20%) of the terminals were GABA-IR and they covered 9.6% of the surface analyzed. These data demonstrate that GABA-IR terminals synapse directly on STT cells, constituting a substantial proportion of the terminal population on these cells. Furthermore, compared to the cell bodies, a greater percentage of the input on the proximal dendrites is GABAergic. These anatomical data are consistent with the findings of a previously published iontophoretic study that demonstrated that GABA can exert a strong inhibitory influence on STT cells. These findings are discussed in relation to GABAergic involvement in tonic and phasic inhibition of STT neurons.

Isolated cardiomyocytes in conjunction with NMR spectroscopy techniques to study metabolism and ion flux

To distinguish cellular from vascular responses to physiological and pathophysiological stimuli, we developed methods to perform NMR spectroscopy on isolated ventricular cardiomyocytes. Isolated adult rat cardiomyocytes, placed in agarose beads and superfused with phosphate-free buffer (Media 199 (GIBCO 400-1100) gassed with 95% O2, 5% CO2), were used to evaluate a variety of cellular processes during different pharmacological and physiological interventions. Bioenergetic function was monitored with 31P NMR. Intermediary metabolism, gluconeogenesis, and glycolysis were monitored with 13C NMR. Sodium flux was monitored with 23Na NMR. Calcium flux was monitored with 19F NMR in conjunction with an intracellular calcium-chelating agent, 5F-1,2-bis(2-amino-phenoxy)ethane-N,N,N',N'-tetraacetic acid. Creatine kinase kinetics (forward rate constant (Kf) and flux of phosphocreatine to ATP) were estimated with 31P NMR saturation transfer data. Various combinations of NMR parameters were monitored simultaneously so that the interaction of metabolism and ion flux could be evaluated. We have demonstrated that it is possible to simultaneously monitor a variety of cellular processes in intact heart cells in real time, without the confounding influences of perfusion, contractile function, and extrinsic blood-borne neurohumoral agents. This model will be useful for longitudinal studies of myocyte metabolism and ion flux.

Substance-P-like immunoreactive amacrine cells in the adult and the developing rat retina

Substance-P-like immunoreactivity (SP-LI) cells in the Long-Evans rat retina were investigated by combining immunohistochemistry with [3H]thymidine autoradiography. Two subpopulations of SP-LI amacrine cells, with cell bodies in either the proximal portion of the inner nuclear layer (INL) or the ganglion cell layer (GCL), were identified based on morphology, pattern of distribution and development. In the INL, SP-LI cells were found scattered throughout the retina. However, in the GCL, they were limited to the superio-temporal region. Such a contrast in distribution specific to nuclear layers was present upon first detection of SP-LI amacrine cells and persisted throughout development. Birthdating revealed a temporal lag in the histogenesis of SP-LI cells situated in the GCL relative to that in the INL, suggesting that the two subpopulations developed separately. Overall, unique anatomical features of the SP-LI amacrine cells in the rat retina were observed which could only have been uncovered through detailed analyses in the adult as well as during postnatal development.

Dietary zinc methionine effect on eggshell quality of hens drinking saline water

In two experiments individually caged 60-wk-old laying hens were exposed to daily temperatures ranging between 18 and 35 C and given various dietary and drinking water treatments. In Experiment 1 these were: 1) basal diet and town water; 2) basal diet and town water supplemented with 2 g NaCl/L; 3) basal diet supplemented with .2 g zinc methionine (Zinpro-200)/kg diet and town water; or 4) basal diet supplemented with .2 g zinc methionine/kg and town water supplemented with 2 g NaCl/L. In Experiment 2, Treatments 1 and 2 were the same as in Experiment 1. Birds on Treatments 3 and 4 received the town water supplemented with 2 g NaCl/L and the basal diet supplemented with either .5 g zinc methionine/kg (Treatment 3) or .28 g ZnSO4H2O/kg to approximate the same dietary zinc concentration in Treatment 3 (Treatment 4). In both experiments, dietary zinc methionine plus 2 g NaCl/L in the drinking water significantly improved shell breaking strength over those birds on the 2 g NaCl/L with no zinc methionine supplementation. This same pattern occurred for shell weight, shell weight per unit of surface area, and percentage of shell defects. There were no improvements in the parameters measured from the supplementation of ZnSO4. The zinc methionine compound apparently was effective in overcoming the negative influence of the added 2 g NaCl/L of town water.

The purification of a guanine nucleotide regulatory protein from rat brain membrane and the measurement of its GTPase

A guanine nucleotide regulatory protein (G-protein) was purified to homogeneity from rat brain membrane though a series of chromatography runs, including DE-52 ion exchange, AcA-34 ultrogel, and octyl-Sepharose columns. The purified G-protein consisted of 3 subunits with molecular weights of 41000, 36000, and 8000, respectively. The alpha-subunit of the G-protein possessed high affinity GTP binding sites (k = 22.5 nmol/L) and GTPase activity (Km = 82.5 nmol/L, Vmax = 2.8 pmol/min/microgram protein), and it could be ADP-ribosylated by [adenylate-32P]-NAD in the presence of pertussis toxin. These results suggest that the purified protein was Gi-protein.

Changes in the response states of primate spinothalamic tract cells caused by mechanical damage of the skin or activation of descending controls

1. The responses of a population of 318 spinothalamic tract (STT) cells to mechanical stimulation of the skin were recorded in anesthetized macaque monkeys by several teams of investigators. The responses were subjected to k-means cluster analysis, a multivariate statistical procedure. 2. For an analysis that pertained to the responsiveness of the neurons, the mean responses to four standard mechanical stimuli (Brush, Pressure, Pinch, and Squeeze) were used. Although no true clusters were found, the cells could be partitioned into four groups (called clusters a, b, c, and d) that responded progressively more vigorously to the stimuli. 3. For an analysis that pertained to the selectivity of the cells for various stimulus intensities, from innocuous to highly noxious, the data were normalized by taking the ratio of the mean response evoked by each stimulus to the sum of the responses and multiplying by 100. This procedure does not have a bias toward selection of any particular number of clusters and resulted in three clusters of STT cells. 4. Cluster 1 STT cells responded best to Brush. Cluster 2 cells responded weakly to Brush and Pressure and maximally to Pinch. Cluster 3 cells responded weakly to Brush, Pressure, and Pinch and maximally to Squeeze. 5. The response states of STT cells with respect to mechanical stimulation of the skin can be defined by their cluster assignments on the basis of the responsiveness (clusters a-d) and selectivity (clusters 1-3) of the cells. The response states of newly recorded STT cells can be determined by discriminant analysis from the nearest centroids of the two types of clusters in the reference population of STT cells. 6. No consistent changes in response state were detected when a second series of mechanical stimuli was applied 1 cm from the site stimulated initially or when the stimulus series was alternately repeated at the initial site and at progressively more proximal sites. However, when the stimulus series was applied five times to the initial site, the response state of five of eight cells tested showed a change. Although a change in response state required repetitive damage, even a single stimulus series increased background activity and responses to Brush at undamaged sites. 7. The background activity and responses to Brush and Pressure of all five STT cells recorded in the superficial laminae increased after repeated testing. The background activity of five STT cells recorded in the nucleus proprius also increased, but the responses of only three of the cells to Brush and Pressure increased.(ABSTRACT TRUNCATED AT 400 WORDS)

l-Homocysteic acid selectively activates receptors of rat retinal ganglion cells

To explore the possible role of L-homocysteic acid (HCA) as a retinal transmitter, whole-cell recordings with patch electrodes were performed on isolated rat retinal ganglion cells (RGCs) in culture. HCA elicited an inward current at -60 mV. Similar to currents evoked at this potential in RGCs by N-methyl-D-aspartate (NMDA), HCA-activated currents were of relatively small amplitude (10-150 pA), and the noise level increased dramatically during the response. When HCA was co-applied with concentrations of NMDA that elicited a maximal response, the current was not increased over that of NMDA alone. HCA-evoked currents were almost completely blocked by the NMDA antagonists D-2-amino-5-phosphonovalerate (D-AP5), Mg2+, or 7-chlorokynurenate (7-Cl KYN). Unlike its effects on other preparations, even millimolar concentrations of HCA did not activate kainate-like currents. These observations suggest that HCA specifically activates the NMDA receptor-channel complex of rat RGCs.

Digital pure shear-strain moiré patterns

A method of constructing digital shear-strain moiré patterns with pure shear-strain fringes is proposed here with the help of digital image processing techniques and moiré carrier patterns of rotation. This method is developed from a digital pure secondary moiré pattern method. The pure shear-strain moiré patterns do not require a high fringe density of primary moiré patterns. It can give the shear-strain values at every point over the whole field and give the visible distribution of the shear-strain field.

Parallel subtraction of Fourier power spectrum using holographic interferometry

We propose and demonstrate parallel subtraction of the Fourier power spectrum of two images with the use of real-time holographic interferometry. The subtraction, which exhibits shift invariance, is achieved by employing a Mach-Zehnder interferometer and a photorefractive crystal. The results are presented and discussed.

Creatine and cyclocreatine effects on ischemic myocardium: 31P nuclear magnetic resonance evaluation of intact heart

The purpose of this study was to investigate the effects of prior dietary supplementation with creatine (Cr) or cyclocreatine (Cy, a synthetic analogue of Cr) on high energy phosphate metabolism of the ischemic myocardium. To this end, 48 rats were fed the following powdered rat chow diet for 21 days: 16 were fed chow without additives (CON); 16 were fed a diet containing 1% Cr by weight (CR); 16 were fed a diet containing 1% Cy by weight (CY). At the end of the feeding period, rats were anesthetized, hearts harvested and perfused in the Langendorff mode using Krebs-Henseleit buffer (maintained at 37 degrees C, equilibrated with 95% O2/5% CO2) to which 11 mM glucose was added. 31P nuclear magnetic resonance (NMR) studies of myocardial bioenergetics were done using a Bruker AM 500 spectrometer. After acquisition of preischemic spectra, global ischemia was produced by clamping aortic inflow. Ischemia was maintained until adenosine triphosphate (ATP) became NMR invisible (CON = 34 +/- 11 min; CR = 32 +/- 13 min; CY = 56 +/- 13 min; p less than 0.05 CY vs. CR and CON). Half-lives of ATP were 19 min for CON and CR and 37.5 min for CY; half-lives of phosphagen were 4 min for CON and CR and 11 min for CY. Time for return of mechanical function (heart rate x systolic pressure) after ischemia was similar for all three groups (CON = 28 +/- 28, CR = 34 +/- 22, and CY = 22 +/- 15 min), even though the CY group was subjected to longer periods of ischemia). These data indicate that CY, but not CR, pretreatment provides myocardial protection either during and/or after ischemia and allows return of mechanical function after much longer episodes of ischemia than in CON and CR. One factor in the mechanism of protection may be the prolonged maintenance of phosphagen due to the higher equilibrium concentration of phosphocyclocreatine which in turn provides substrate for continued synthesis of ATP during and after ischemia, thus defining Cy as a bioenergetic protective agent. Other mechanisms of protection remain to be defined.

Effect of helium-neon laser irradiation on serum lipid peroxide concentrations in burnt mice

The effect of helium-neon irradiation on serum lipid peroxide concentrations in mice following 6-7% body surface area burns was investigated in a controlled study. Immediately following injury by an 8-sec 100 degrees C scalding, 25 mice were irradiated by a helium-neon laser at 0.05 J/cm2. A control group of the same size underwent identical treatment but received only sham irradiation. Serum lipid peroxide concentrations increased markedly in the control group at 0.5-4 h (P less than 0.0001, two sample t-test). In the laser treated group, the lipid peroxide concentrations remained relatively constant and were significantly depressed relative to the control group 4 h following burning (P less than 0.0001, two-sample t-test).

Responses in egg shell quality from dietary ascorbic acid supplementation of hens receiving saline drinking water

Three experiments were conducted to determine whether the poor shell quality of eggs from hens receiving saline drinking water could be improved by the simultaneous addition of ascorbic acid to the diet. In one experiment, the responses were compared with those of hens receiving ascorbic acid in the drinking water. In this experiment, providing the ascorbic acid in the drinking water on a daily basis was compared with dosing the water on alternate days. The results showed that saline water increased the incidence of egg shell defects without affecting food and water intakes, egg production or egg weight. Changes in a range of shell quality measures mirrored the changes in the incidence of egg shell defects. Supplementation of the diet or drinking water with ascorbic acid prevented the increase in shell defects and the decrease in shell quality. The degree of response to dietary ascorbic acid was dependent on the concentration used, a response similar to that observed previously when the ascorbic acid was added to the drinking water.

[Methanogens from feces of patients with intestine disorder]

Fecal specimens from 10 colorectal cancer, 1 duodenum diverticulosis and 2 healthy adults were examined. Nine fecal enrichments contained Methanobrevibacter. The percentage of methanogen positive individuals was 69% Methanobrevibacter were isolated from fecal enrichments of 4 colorectal cancer and 1 duodenum diverticulosis. The percentage of breath methane positive individuals and methane production had significantly increased in colorectal cancer patients. It will be hopeful that methane production in breath samples at the end of exhalation will became a rapid, simple and non-penetrative method for monitoring precancerous colonic or rectal carcinogenesis and monitoring the relapse of individuals with carcinosectomy.

[Characterization of a human cell line from an anaplastic carcinoma of the thyroid gland]

A new cell line derived from a thyroid anaplastic carcinoma, CAL 62, has been established in culture. This line is constituted by highly tumorigenic cells. Their epithelial phenotype is stable in culture. Immunochemical staining for human thyroglobulin is negative. Cytogenetic analysis showed a gain of chromosome 20, the translocation i (14q), and breakpoints of centrometric chromatine. These results are similar to those previously reported by other investigators. CAL 62 radiosensibility has been studied. The survival curve of the in vitro irradiated cells has been adjusted with a linear-quadratic model. This cell line is thus showed to be radioresistant. Cell line CAL 62 constitutes an appropriate model for in vitro studies of thyroid anaplastic carcinoma.

In vivo correlation of myocardial metabolism, perfusion, and mechanical function during increased cardiac work

STUDY OBJECTIVE

The aim was to study the in vivo interaction and regulation of myocardial perfusion, metabolism, and pump function in an open chest canine model using a combination of potentially non-invasive and clinically useful techniques.

DESIGN

To assess potential regulatory mechanisms and the interaction of myocardial perfusion, metabolism, and contractile function responses during changes in cardiac workload, noradrenaline (1 microgram.kg-1.min-1) was infused and hypoxia was produced by increasing the inspired ratio of nitrogen to oxygen to produce a PaO2 of 2.6-4.0 kPa in separate interventions.

SUBJECTS

Nine mongrel dogs of either sex, age 2-5 years, weight 8.5(SD 2.2) kg, were studied in separate interventions.

MEASUREMENTS AND MAIN RESULTS

Myocardial perfusion was determined using 2H nuclear magnetic resonance (NMR) measured washout of deuterium oxide from the left ventricle interpreted with a one component Kety-Schmidt exponential model. High energy phosphate bioenergetics were determined by 31P NMR measurements of the phosphocreatine/ATP ratio. Redox state was estimated by nicotinamide adenine dinucleotide fluorometry expressed as percent change from the baseline, normalised to maximum response measured at 100% inspired N2. Mechanical function was evaluated using heart rate X systolic blood pressure and oxygen consumption measurements. During both noradrenaline infusion and hypoxia, mechanical function increased significantly from control values: heart rate X systolic blood pressure = 1.9(SD 0.5), 3.6(0.1), and 2.6(0.4), respectively; oxygen consumption = 0.9(2), 1.6(0.1), and 1.2(0.6) ml.min-1.100 g-1. Myocardial perfusion increased to support the increased workloads, from 87(10) to 131(20), and from 60(12) to 182(14) ml.min-1.100 g-1, respectively. ADP, estimated by the phosphocreatine/ATP ratio, did not change during noradrenaline infusion [2.4(0.2) to 2.4(0.7)], but decreased during hypoxia [2.4(0.4) to 1.7(0.5)]. Redox state decreased during noradrenaline infusion, from 100% to 84(0.7)%, and increased during hypoxia, from 100% to 140(10)%.

CONCLUSIONS

Similar changes in workload induced by different physiological stimuli are associated with different biochemical responses even though changes in perfusion are similar. The data suggest that myocardial function is regulated by different biochemical mechanisms under different physiological conditions, ie, there is probably no universal regulator of myocardial function. It is now possible to evaluate potential metabolic regulators of myocardial function in an in vivo animal model.

Histochemical studies on the mechanism of macromolecule leakage across the glomerular capillary wall. Barrier effect of the anionic groups of the capillary wall against the serum protein leakage

For the purpose of revealing the barrier effect of the anionic groups of glomerular capillary wall against the serum protein leakage, morphologic and histochemical observations were made on the rat kidney perfused in situ with three kinds of cationic macromolecules different in chemical characteristics followed by blood flow restoration. The polyethyleneimine perfusion resulted in the complete disapperance of ionized anionic groups of glomerular capillary and the massive protein leakage through glomeruli by blood flow restoration. Cationic ferric colloid perfusion induced moderate protein leakage, and avidin perfusion was less in neutralization effect of anionic groups and the protein leakage was of least. The protein leakage from glomeruli, however, was stopped or markedly suppressed soon after the blood flow restoration by the newly formed functioning anionic barrier probably by some particular serum protein deposition. The findings indicate that the deionization of the glomerular capillary wall will not be responsible for the persistent albuminuria.

Clinical observations on acupuncture treatment of peripheral facial paralysis aided by infra-red thermography--a preliminary report

We have carried out clinical observations on 34 patients with peripheral facial paralysis treated by acupuncture therapy prescribed according to selection of treatment regimen on the basis of facial thermogram and temperature. A comparison was made with a control group of 97 patients who received conventional acupuncture therapy only. It was found that 1) The cure rate in the group of selecting acupoints by thermogram (hereinafter referred to as the thermography--aided treatment group) was 67.65%, with a marked improvement rate of 26.40%; while the cure rate of the conventional acupuncture treatment group (hereinafter called the conventional treatment group) was 46.39%, the marked improvement rate being 29.90%, indicating a significant difference in therapeutic efficacy between the two groups (P less than 0.02). 2) The average duration of acupuncture therapy for the thermography aided treatment group was 6.02 weeks, whereas that for the conventional treatment group, 24 weeks. There was also a significant difference between the two groups (P less than 0.01). And 3) During the entire therapeutic course, 25.2 sessions of treatment were given on the average in the thermography--aided treatment group, and 78.8 sessions in the conventional treatment group, showing a very significant difference (P less than 0.001). The present thermography--aided method exhibits advantages over the conventional one in enhancing the cure rate and shortening the duration of treatment, which is worthy to be popularized in clinical practice. And it is also of certain significance in standardization and scientification of acupuncture therapy.

Corticotropin releasing factor-like immunoreactivity (CRF-LI) in horizontal cells of the developing rat retina

This study describes a phenomenon of transient expression of corticotropin releasing factor-like immunoreactivity (CRF-LI) in immature horizontal cells of the developing rat retina. These cells could be distinguished from those destined to become CRF-LI amacrine cells in the adult by their location within the outer portion of the neuroblastic layer (NBL) and by their ontogenetic pattern. Upon initial detection on postnatal day 3 (PD-3), faint CRF-LI cellular profiles were found in the outer portion of the NBL, limited to the central region of the retina. Subsequently, on PD-5, these profiles began to appear in the periphery, forming a single horizontal row along the outermost aspect of the developing inner nuclear layer (INL), concomitant with the establishment of the outer plexiform layer (OPL). The results of our birth-dating study combining immunohistochemistry and [3H]-thymidine autoradiography indicated that these cells were generated between embryonic day 14 and 18. These findings are consistent with them being horizontal cells. Between PD-7 and PD-9, CRF-LI in horizontal cells began to diminish progressively following a center-to-periphery gradient such that only sporadic, faintly immunoreactive patches of cells could be seen by the time of eye opening (PD-15). Around PD-19, it declined to levels below immunohistochemical detection. However, when rats were reared in complete darkness beginning at birth until PD-21, the period of CRF-LI expression in horizontal cells was prolonged and persisted throughout the first three postnatal weeks of development.

Anticardiolipin antibodies: a study of frequency in TIA and stroke

We undertook a prospective study of consecutive patients to determine the frequency of elevated IgG and IgM anticardiolipin antibodies in transient ischemic attack and ischemic stroke and found elevated IgG antibodies in 8.2% (9 of 110) and IgM in 9.1% (10 of 110), only the former being significantly greater than in a healthy control population. We suggest that anticardiolipin screening be concentrated on the young.

Use of ascorbic acid to prevent the decline in eggshell quality observed with saline drinking water

Three experiments were carried out to determine the value of ascorbic acid in overcoming the poor eggshell quality problem associated with the use of saline drinking water. Laying hens were supplied with either town water or town water supplemented with NaCl, ascorbic acid, or a combination of NaCl and ascorbic acid. Supplementing the drinking water lf laying hens with NaCl (2 g/L) significantly increased the incidence of eggshell defects and significantly decreased eggshell quality. Simultaneous supplementation of the saline drinking water with ascorbic acid (1 g/L) prevented these detrimental effects. This response to ascorbic acid was dependent upon concentration. Ascorbic acid acted as a preventive rather than a remedial treatment: hens producing eggs with defective shells as a result of receiving saline drinking water failed to show any improvement in eggshell quality or any reduction in the incidence of eggshell defects when the saline water was supplemented with ascorbic acid.

Reproductive performance of artificially inseminated hens receiving saline drinking water

Laying hens were selected at random and placed in individual cages in a commercial type layer shed. One hundred hens received town water and one hundred received town water supplemented with 2 g NaCl/L. Half the hens on each water treatment were inseminated every 7 days with mixed semen collected from six cockerels of a commercial table egg strain maintained on town water. The remaining hens were inseminated with semen from six cockerels receiving town water supplemented with 2 g NaCl/L. Eggs were collected and stored at 12 C over a 7-day period before eggs with defective shells were identified and removed. All remaining eggs were incubated and candled at 7 and 18 days of incubation to detect infertile eggs and embryonic deaths. Data from six consecutive hatches were analyzed. The incidence of eggs with defective shells doubled in hens receiving the saline drinking water. These hens had a significantly (twofold) higher incidence of embryonic deaths and a significantly lower (13%) hatchability of fertile eggs. For every 100 eggs laid the numbers of settable eggs and chicks hatched were significantly reduced in hens receiving the saline drinking water. The saline water reduced the numbers hatched by 20% for every 100 eggs laid. The water treatment given to the cockerels had little effect on reproductive performance.