Nitric oxide synthase-containing neural processes on large cerebral arteries and cerebral microvessels

We studied whether neural processes containing nitric oxide synthase (NOS) are associated with large cerebral arteries and/or intraparenchymal microvessels. The presence of NOS-positive nerves on large cerebral arteries was examined in whole-mount preparations processed for NADPH diaphorase histochemistry, a procedure that stains NOS-containing neurons. The association between NOS-containing neural processes and intracerebral microvessels was studied by electron microscopy in ultrathin brain sections reacted with antibodies against NOS. A dense perivascular plexus of NADPH diaphorase positive axons was observed in the anterior portion of the circle of Willis and its branches while in the basilar artery the innervation was less dense. Lesions of the major sources of perivascular innervation of the cerebral arteries indicated that these nerve fibers arise from the sphenopalatine ganglia. Within the brain parenchyma, NOS immunoreactivity was observed in dendrites and axonal terminals closely associated with the basal lamina of arterioles and capillaries. We conclude that NOS-containing nerves of peripheral origin innervate large cerebral arteries while NOS-containing neural processes of central origin, especially dendrites, are closely associated with cerebral arterioles and capillaries. The presence of NOS in perivascular dendrites raises the possibility that these structures are a major source of NO during neural activity. These findings, collectively, provide morphological evidence supporting the hypothesis that NOS neurons participate in the mechanisms that match neural activity to cerebral blood flow.

Oxidation chemistry of the endogenous central nervous system alkaloid salsolinol-1-carboxylic acid

The oxidation chemistry of salsolinol-1-carboxylic acid (1), an alkaloid endogenous to the central nervous system which is elevated as a result of ethanol consumption, has been studied by electrochemical approaches at pH 7.0 in aqueous solution. The first voltammetric oxidation peak of Ia of 1 at pH 7.0 occurs at Ep = +0.116 V, indicating that this alkaloid is a very easily oxidized compound. The peak Ia reaction is a 2e-2H+ oxidation of 1 to 1,2,3,4-tetrahydro-1-methyl-1-carboxy-6,7-isoquinolinedione (8), which rapidly decarboxylates (k > 10(3) s-1) to give predominantly the quinone methide tautomer of 3,4-dihydro-1-methyl-6,7-isoquinolinediol (2). The latter compound is responsible for the second observed oxidation peak IIa observed with 1. This peak is a 2e oxidation of 2 to a quinoid intermediate (9) which can either be attacked by water to yield 3,4-dihydro-1-methyl-5,7-dihydroxyisoquinolin-6-one (13b) (which is readily further oxidized to 3,4-dihydro-1-methyl-5-hydroxyisoquinoline-6,7-dione (3)) or aromatizes to yield 1-methyl-6,7-isoquinolinediol (4). Preliminary in vivo experiments have revealed that 2 and 13b are behavioral toxins when injected into the brains of laboratory mice. The in vitro oxidation reactions of 1 and 2 reported here might be of relevance to the neurodegenerative, behavioral, and addictive consequences of chronic alcoholism.

Microvascular transfer of the rectus abdominis muscle and myocutaneous flap in rats

A rat microvascular free rectus myocutaneous flap model with a superior epigastric vessel pedicle is presented. The rectus muscle has a predictable "flow-through" axial vascular system consisting of superior and inferior epigastric vessels anastomosing under the fascial sheath, and six to seven musculocutaneous perforating branches to the skin. The superior epigastric artery and vein, averaging 0.45 mm and 0.5 mm in diameter, can be used as the vascular pedicle in muscle or myocutaneous flap transplantation. Eight muscle and 15 myocutaneous flaps were transplanted to the groin. The myocutaneous flaps averaged 3.5 cm by 1.2 cm in size; the pedicle length averaged 11 mm. The 5 day survival was 100% for muscle flaps and 67% for myocutaneous flaps. The rectus myocutaneous flap is believed to be the first true myocutaneous model in the rat.

Unconfined lateral diffusion and an estimate of pericellular matrix viscosity revealed by measuring the mobility of gold-tagged lipids

Nanovid (video-enhanced) microscopy was used to determine whether lateral diffusion in the plasma membrane of colloidal gold-tagged lipid molecules is confined or is unrestricted. Confinement could be produced by domains within the plane of the plasma membrane or by filamentous barriers within the pericellular matrix. Fluorescein-phosphatidylethanolamine (F1-PE), incorporated into the plasma membranes of cultured fibroblasts, epithelial cells and keratocytes, was labeled with 30-nm colloidal gold conjugated to anti-fluorescein (anti-F1). The trajectories of the gold-labeled lipids were used to compute diffusion coefficients (DG) and to test for restricted motion. On the cell lamella, the gold-labeled lipids diffused freely in the plasma membrane. Since the gold must move through the pericellular matrix as the attached lipid diffuses in the plasma membrane, this result suggests that any extensive filamentous barriers in the pericellular matrix are at least 40 nm from the plasma membrane surface. The average diffusion coefficients ranged from 1.1 to 1.7 x 10(-9) cm2/s. These values were lower than the average diffusion coefficients (DF) (5.4 to 9.5 x 10(-9) cm2/s) obtained by FRAP. The lower DG is partially due to the pericellular matrix as demonstrated by the result that heparinase treatment of keratocytes significantly increased DG to 2.8 x 10(-9) cm2/s, but did not affect DF. Pericellular matrix viscosity was estimated from the frictional coefficients computed from DG and DF and ranged from 0.5 to 0.9 poise for untreated cells. Heparinase treatment of keratocytes decreased the apparent viscosity to approximately 0.1 poise. To evaluate the presence of domains or barriers, the trajectories and corresponding mean square displacement (MSD) plots of gold-labeled lipids were compared to the trajectories and MSD plots resulting from computer simulations of random walks within corrals. Based on these comparisons, we conclude that, if there are domains limiting the diffusion of F1-PE, most are larger than 5 microns in diameter.

Microvascular transplant of the gastrocnemius muscle in rats

The rat gastrocnemius muscle can serve as a vascularized, innervated muscle transplant model. To establish the anatomic and technical details of this model, we performed ten gastrocnemius transplants and collected data on muscle weight, dimension, and vessel caliber from each muscle. The muscle, consisting of medial and lateral heads, is supplied by pairs of sural vessels averaging 0.2 mm in diameter. These vessels, however, can be taken in continuity with the femoral vessels (averaging 1.0-1.6 mm in diameter), which are used for transplantation. The muscles weighed an average of 2.8 g, and the average pedicle length was 24 mm. Eight of ten transplanted muscles were viable with intact circulation at 72 hr. The gastrocnemius transplant was technically reliable, and the muscle bulk and contour could allow biochemical and functional studies. Donor site morbidity limits this model to transplantation studies.

The dopamine D1 receptor antagonist SCH-23390 decreases the mRNA levels of the transcription factor zif268 (krox-24) in adult rat intact striatum--an in situ hybridization study

By in situ hybridization with an oligonucleotide probe, we have studied the cellular distribution of the messenger RNA encoding the transcription factor zif268 (krox-24) in the adult intact rat striatum and regulation of its synthesis by acute treatment with the dopamine D1 receptor antagonist SCH-23390. Zif268 mRNA was found in the striatal medium-sized neurons and not in the large cells. Its levels were decreased by SCH-23390, suggesting activation of this immediate early gene in the striatum through dopamine D1 receptor stimulation.

Somatostatin concentrations in cerebrospinal fluid and brain tissue of patients with refractory epilepsy

The somatostatin concentrations of cerebrospinal fluid (CSF) and brain tissue in 16 refractory epileptic patients were measured simultaneously by a radioimmunoassay (RIA) method. An increased level of somatostatin was found in the epileptic foci of cerebral cortex, determined by the cortical EEG. There were significant differences among the epileptic foci (75.58 +/- 6.58 pg/mg wet wt, +/- SEM), nonfocal tissues (37.04 +/- 6.55 pg/mg), and normal tissues of control patients (47.69 +/- 10.12 pg/mg), p < 0.001 and p < 0.05, respectively. The somatostatin concentrations of CSF in 11 epileptic patients were determined before (257.78 +/- 19.11 pg/mL) and after (178.36 +/- 8.78 pg/mL) the removal of epileptic focal area, and a dramatic decrease of the CSF somatostatin concentration after operation was detected (p < 0.01). We also found that the somatostatin level of cerebral scar induced by head injury in cases of posttraumatic epilepsy was highest (106.39 +/- 12.41 pg/mg). The results suggested that the surgical removal of the epileptic focal area in refractory epileptic patients may reduce the increased central somatostatin level, which could play an important part in the pathophysiological process of refractory epilepsy.

Stimulation of the fastigial nucleus enhances EEG recovery and reduces tissue damage after focal cerebral ischemia

Stimulation of the cerebellar fastigial nucleus (FN) increases CBF but not metabolism and reduces the tissue damage resulting from focal cerebral ischemia. This effect may result from enhancing CBF in the ischemic tissue without increasing local metabolic demands. To test this hypothesis, we studied whether the reduction in tissue damage is restricted to the neocortex, a region in which the CBF increase is independent of metabolism, and whether stimulation of the dorsal medullary reticular formation (DMRF), a treatment that increases both cerebral metabolism and CBF, also protects the brain from ischemia. In halothane-anesthetized Sprague-Dawley rats, the middle cerebral artery (MCA) was occluded either proximally or distally to the lenticulostriate branches. The FN or DMRF were then stimulated for 1 h (50-100 microA; 50 Hz; 1 s on/l s off). Twenty-four hours later, the infarct volume was determined. FN stimulation substantially reduced the size of the infarct, an effect that was greater with distal (-69 +/- 8%; n = 6; p < 0.001; mean +/- SD) than with proximal (-38 +/- 8%; n = 8; p < 0.001) MCA occlusion. The reduction occurred only in neocortex (-43 +/- 9%; p < 0.001) and not in striatum (-16 +/- 21%; p > 0.05). Stimulation of the FN also enhanced recovery of EEG amplitude in the ischemic cortex (+48%; p < 0.003). DMRF stimulation (n = 7) did not affect the stroke size or EEG recovery (p > 0.05). Thus, stimulation of the FN, but not the DMRF, attenuates the damage resulting from focal ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)

DNA methylation represses FMR-1 transcription in fragile X syndrome

Fragile X syndrome is the most frequent form of inherited mental retardation and segregates as an X-linked dominant with reduced penetrance. Recently, we have identified the FMR-1 gene at the fragile X locus. Two molecular differences of the FMR-1 gene have been found in fragile X patients: a size increase of an FMR-1 exon containing a CGG repeat and abnormal methylation of a CpG island 250 bp proximal to this repeat. Penetrant fragile X males who exhibit these changes typically show repression of FMR-1 transcription and the presumptive absence of FMR-1 protein is believed to contribute to the fragile X phenotype. It is unclear, however, if either or both molecular differences in FMR-1 gene is responsible for transcriptional silencing. We report here the prenatal diagnosis of a male fetus with fragile X syndrome by utilizing these molecular differences and show that while the expanded CGG-repeat mutation is observed in both the chorionic villi and fetus, the methylation of the CpG island is limited to the fetal DNA (as assessed by BssHII digestion). We further demonstrate that FMR-1 gene expression is repressed in the fetal tissue, as is characteristic of penetrant males, while the undermethylated chorionic villi expressed FMR-1. Since the genetic background of the tissues studied is identical, including the fragile X chromosome, these data indicate that the abnormal methylation of the FMR-1 CpG-island is responsible for the absence of FMR-1 transcription and suggests that the methylation may be acquired early in embryogenesis.

[Study on casting precision of plat castable ceramic crowns]

The plat castable ceramic crown was made with investment material prepared in our college with our own casting technique by a Chinese-made casting machine. The accuracy and fitness of the crown were studied and appraised. Results show that the margin of fitness is 46 microns and that the cement film thickness of the dies in the spacer material group is 65.13 microns. Hence the results are satisfactory. The Plat castable ceramic crown might be used in clinical dentistry.

PCR amplification and analysis of yeast artificial chromosomes

A strategy for the analysis of yeast artificial chromosome (YAC) clones that relies on polymerase chain reaction (PCR) amplification of small restriction fragments from isolated YACs following adapter ligation was developed. Using this method, termed YACadapt, we have amplified several YACs from a human Xq24-qter library and have used the PCR products for physical mapping by somatic cell hybrid deletion analysis and fluorescent in situ hybridization. One YAC, RS46, was mapped to band Xq27.3, near the fragile X mutation. The PCR product is an excellent renewable source of YAC DNA for analyses involving hybridization of YAC inserts to a variety of DNA/RNA sources.

Spontaneous incorporation of the glycosyl-phosphatidylinositol-linked protein Thy-1 into cell membranes

Thy-1 is a membrane protein that is attached to the plasma membrane by a glycosyl-phosphatidylinositol anchor. Purified rat brain Thy-1 could be reincorporated into the plasma membrane of murine Thy-1- cells directly from aqueous suspension and without the use of detergents. A peripheral staining pattern similar to that observed for endogenous Thy-1 was achieved. Treatment with phosphatidylinositol-specific phospholipase C removed nearly all antibody staining due to either endogenous or inserted Thy-1. Fluorescence recovery after photobleaching (FRAP) was used to compare the lateral mobility of endogenous and inserted Thy-1. Both forms exhibited large lateral diffusion coefficients, but with a substantial immobile fraction (approximately 50%) indicating that the immobile fraction was not due either to chemical differences between inserted and native Thy-1 or to some surface Thy-1 molecules having a protein anchor. However, the inserted Thy-1 failed to activate mouse T lymphocytes upon crosslinking as assayed by [3H]thymidine uptake. Since Thy-1 could be directly labeled with rhodamine, the effect of the size of the labeling ligand on the mobility obtained by the FRAP technique could be explored. Rhodamine-conjugated MRC-OX7 monoclonal antibody or its fragments [R-F(ab)2 or R-Fab] were compared with rhodamine as labels for Thy-1. The measured diffusion coefficients were 1.6 x 10(-9), 2.0 x 10(-9), and 3.2 x 10(-9) cm2/sec for Thy-1 labeled with R-F(ab)2, R-Fab, and rhodamine, respectively; mobile fractions were all in the 40-50% range. Thus, the size of the ligand affects the lateral mobility of this labeled membrane protein to a measurable extent.

[Thixotropic properties of whole blood in children with congenital heart disease]

The thixotropic parameters of whole blood in two groups of children with congenital heart disease (CHD) were measured. Group 1. cyanotic heart disease (CCHD), 20 cases; Group 2. acyanotic heart disease (ACHD), 30 cases. Fifty healthy children were controls matched with the patients in sex and age. Their thixotropic parameters were compared; the paired t-test was used. In the children with CCHD, the hematocrit (HCT), the yield stress (tau 0) the Newtonian contribution of viscosity (mu), the equilibrium value of the structural parameter (A), the apparent viscosity at 2.37 sec-1 (eta s) and the Non-Newtonian contribution of viscosity (eta s-mu) were significantly higher than those in corresponding control groups. In the children with ACHD, only the values of tau 0, eta s-mu, and eta s were higher than those in control groups. All of the thixotropic parameters in CCHD group were significantly higher than those in ACHD group. Thus we described quantitatively CHD in terms of thixotropy of blood. The thixotropic parameters of blood could be used as indexes of severity for pathologic changes of CHD.

Hemin-catalyzed decomposition of artemisinin (qinghaosu)

Artemisinin (qinghaosu) and its derivatives represent an important new class of antimalarial drugs. Previous work suggests that the antimalarial activity of artemisinin may be mediated by a reaction with intraparasitic hemin. Using cyclic voltammetry, artemisinin and dihydroartemisinin were irreversibly reduced at approximately -1 V. In the presence of concentrations of hemin as low as 50 nM, the reduction took place at much lower potentials (-0.435 to -0.460 V). Both reductions took place after adsorption onto the electrode surface. The shift of the reduction potential to more positive values is indicative of a catalytic process similar to that seen with hydrogen peroxide. The catalytic decomposition of artemisinin may play a role in the antimalarial activity of artemisinin.

Temperature and strain sensitivities of high-birefringence elliptical fibers

We have analyzed and calculated the temperature and strain sensitivities of a high-birefringence double-clad elliptical fiber. We propose a method to minimize these sensitivities without increasing the fiber size or weight; this is achieved by selecting suitable fiber parameters-core ellipticity, refractive index difference, and thickness of the inner cladding. In addition, we discuss the design of temperature- or strain-insensitive fibers which may be used in polarimetric strain or temperature sensors. This method may also be used to minimize or enhance other external effects.

Islet amyloid polypeptide immunoreactivity in the human fetal pancreas

Islet amyloid polypeptide is known to localize to the adult human Beta cell. We analysed the immunoreactivity for islet amyloid polypeptide in a series of 29 human fetal pancreata (9-24 weeks of gestation) with respect to age dependency and cellular localization using an antibody raised against synthetic rat islet amyloid polypeptide 12-37. Cells immunoreactive for islet amyloid polypeptide were demonstrated in low numbers from week 13 onwards while insulin positivity was already present at 9 weeks of gestation. In the age group 13-16 gestational weeks, cells positive for insulin were 20-fold more frequent than cells positive for islet amyloid polypeptide. This difference gradually disappeared with age, reaching parity in the adult gland. Double immunostaining demonstrated that all islet amyloid polypeptide immunoreactivity co-localized with insulin. Co-expression of insulin and islet amyloid polypeptide was more frequent in Beta-cell clusters (greater than or equal to 10 cells) than in single Beta cells; islet amyloid polypeptide positivity was present in 58 +/- 9% (mean +/- SEM; n = 4) of fetal, 88 +/- 9% (n = 3) of neonatal and 100% (n = 3) of adult clustered Beta cells, and only 8-18% of the single Beta cells. The results suggest that the developing fetal Beta cells, dependent on age and localization, differ in their capacity to express detectable amounts of immunoreactive islet amyloid polypeptide. Beta-cell maturation might therefore be associated with islet amyloid polypeptide expression.

Characterization of the hemolysin transporter, HlyB, using an epitope insertion

The prokaryotic hlyB gene product is a member of a superfamily of ATP-binding transport proteins that include the eukaryotic multidrug-resistance P-glycoprotein, the yeast STE6, and the cystic fibrosis CFTR gene products (Juranka, P. F., Zastawny, R. L., and Ling, V. (1989) FASEB J. 3, 2583-2592). Previous genetic studies have indicated that HlyB is involved in the transport of the 107-kDa HlyA protein from Escherichia coli; however, the HlyB protein has not been purified for biochemical studies due to its low abundance. In this study, we have engineered a monoclonal antibody epitope into the C-terminal end of HlyB that did not destroy its function. This has allowed us to use immunological methods to identify and localize various molecular forms of the HlyB protein present in vivo.

Titration calorimetric and differential scanning calorimetric studies of the interactions of n-butanol with several phases of dipalmitoylphosphatidylcholine

The interactions of n-butanol with dipalmitoylphosphatidylcholine (DPPC) were studied using titration calorimetry and differential scanning calorimetry (DSC). DSC results indicated that n-butanol induces the interdigitated phase in DPPC above 10 mg/mL butanol. A new application of titration calorimetry for measuring partition coefficients of nonsaturating solutes into lipids was developed. The partition coefficients and the heat of binding of n-butanol into DPPC were measured for the L beta', P beta', L alpha, and L beta I phases of DPPC. The partition coefficients were temperature dependent and ranged from 70 to 110 for the L beta I phase, from 170 to 183 for the L alpha phase, and similar to that for the L beta I phase in the P beta' phase. The binding to the L beta' phase could not be detected, giving an upper limit for this partition coefficient of 23. The enthalpies for binding to the L beta I and L alpha phases were 1.0 and 1.5 kcal/mol, respectively. The van't Hoff enthalpy was in good agreement with the calorimetric enthalpy for the partitioning into the L alpha phase; however, it was greater than the calorimetric enthalpy for the L beta I phase, suggesting that the interaction of n-butanol with this phase is cooperative in some way.

Oxidation chemistry and biochemistry of the central mammalian alkaloid 1-methyl-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline

The electrochemical oxidation of the central mammalian alkaloid 1-methyl-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline (1) has been studied in neutral aqueous solution at a pyrolytic graphite electrode (PGE). Voltammograms of 1 show two closely spaced oxidation peaks, Ia and IIa. At potentials less positive than the peak potential (Ep) for peak Ia, 1 is oxidized to a radical intermediate which dimerizes to give two diastereomers of 5,5'-bi(1-methyl-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline) (5 and 6). At potentials more positive than Ep for peak Ia the putative radical intermediate is further electrooxidized to a C(5)-centered carbocation which reacts with 1 in an ion-substrate reaction to give 5 and 6 or with water to give, ultimately, 1-methyl-1,2,3,4-tetrahydro-beta-carboline-5,6-dione (12). Dimers 5 and 6 give two reversible oxidation peaks at the PGE, the second of which corresponds to peak IIa observed in voltammograms of 1. Because 5 and 6 are easily oxidizable compounds they are only observed as products in the initial stages of the controlled potential electrooxidation of 1. Tyrosinase/O2, human ceruloplasmin/O2, and peroxidase/H2O2 also oxidize 1 to 5, 6, and 12 as the initial products. In the presence of glutathione the electrochemically driven and enzyme-mediated oxidations of 1 result in the formation of 5-S-glutathionyl-1-methyl-6-hydroxy-1,2,3,4-tetrahydro-beta-carboline as a major product. Central administration of diastereomer 5 or 6 to mice evoked behavioral responses similar to those caused by the opioid analgesics. These behavioral effects, which include spatial disorientation and a characteristic ducklike walk, became most pronounced approximately 3 h after drug administration and continued for about 3 days. Neurotransmitter and related metabolite analyses of whole brain reveal that 5 and 6 cause a general increase in dopaminergic and serotonergic activity and a small but significant decrease in cholinergic activity. These transmitter/metabolite disturbances appear to parallel the time course of the observed behavioral effects. The possible roles of in vivo oxidations of 1, an alkaloid which is elevated in mammalian brain following ethanol consumption, in the addictive, behavioral, and neurodegenerative consequences of chronic alcoholism are discussed.

Insulin attenuates vasopressin-induced calcium transients and a voltage-dependent calcium response in rat vascular smooth muscle cells

Insulin attenuates the contractile responses of vascular smooth muscle (VSM) to various agonists. Insulinopenic and insulin-resistant rats lack this normal attenuation of vascular contractile responses. To study this attenuating mechanism, the effects of insulin on calcium (Ca2+) responses of cultured VSM cells (a7r5) to arginine vasopressin (AVP) and membrane potential were investigated. Insulin (1 and 100 mU/ml) shifted AVP dose-response curves to the right, reducing relative potency of AVP by 16-fold and 220-fold, respectively. Responses to AVP were significantly attenuated within 30 min of insulin application. The AVP-elicited rise in [Ca2+]i was partially dependent upon extracellular Ca2+. AVP-elicited inward current was reduced by 90 min of insulin treatment (100 mU/ml), from a peak current of -103 +/- 27 pA (normal) to -37 +/- 15 pA (insulin treated). Peak voltage-dependent Ca(2+)-dependent inward current was unaffected by insulin; however, the current-voltage curve was shifted 16 +/-3 mV to the right by insulin. Thus, insulin may reduce VSM contractile responses by attenuating agonist-mediated rises in [Ca2+]i mediated, in part, by reductions in Ca2+ influx through both receptor- and voltage-operated channels.

Lateral diffusion of membrane-spanning and glycosylphosphatidylinositol-linked proteins: toward establishing rules governing the lateral mobility of membrane proteins

In the plasma membrane of animal cells, many membrane-spanning proteins exhibit lower lateral mobilities than glycosylphosphatidylinositol (GPI)-linked proteins. To determine if the GPI linkage was a major determinant of the high lateral mobility of these proteins, we measured the lateral diffusion of chimeric membrane proteins composed of normally transmembrane proteins that were converted to GPI-linked proteins, or GPI-linked proteins that were converted to membrane-spanning proteins. These studies indicate that GPI linkage contributes only marginally (approximately twofold) to the higher mobility of several GPI-linked proteins. The major determinant of the high mobility of these proteins resides instead in the extracellular domain. We propose that lack of interaction of the extracellular domain of this protein class with other cell surface components allows diffusion that is constrained only by the diffusion of the membrane anchor. In contrast, cell surface interactions of the ectodomain of membrane-spanning proteins exemplified by the vesicular stomatitis virus G glycoprotein reduces their lateral diffusion coefficients by nearly 10-fold with respect to many GPI-linked proteins.

[Study on thixotropic parameters of whole blood from healthy children]

With low shear-30 rheometer, the authors used a modified protocol to measure thixotropic parameters of whole blood from 200 healthy newborns and children, so as to suggest the normal range of blood thixotropic parameters in four age groups, namely, the newborns, 1 year- group, 5 year- and 10-15 year group. The results demonstrated that the thixotropic parameters in the newborn group were higher than those in other three groups. However, these thixotropic parameters in the group 1-10 years were lower than those in the 10-15 year group. No significant sex differences were noted among the fore three groups, but sex differences appeared obviously in the 10-15 year group. It implied that the changes relying on the age is consistent with children's growth, development and physiologic activities.

The effect of radix Salviae Miltiorrhizae (RSM) on substance P in cerebral ischemia--animal experiment

The levels of substance P (SP) in rat brains were assayed in 64 rats. Bilateral common carotid artery ligation was done in 49 rats. Half an hour before ligation, 25 rats were given 10 g/kg of RSM; 24 rats were given the same volume of normal saline as controls. Sham operation was done in 15 rats. Half an hour and 3 hours after cerebral ischemia, the rats were quickly decapitated. SP concentration was assayed in the cerebral cortex, caudate nucleus and brain stem. In saline-treated animals, the SP level of caudate nucleus at 3-hour group was significantly decreased as compared with the 0.5-hour group and sham-operated group respectively. No significances were found among RSM-treated groups and sham-operated groups. The SP levels were shown: brain stem greater than caudate nucleus greater than cerebral cortex. The preliminary results suggest that SP may be involved in the pathophysiologic procedures of cerebral ischemia and RSM may attenuate the dysfunction of SP during cerebral ischemia.

Fluorescence recovery after photobleaching techniques to measure translational mobility in microscopic samples

The scope of photobleaching applications and the method itself are briefly reviewed. Two current applications in this laboratory are then outlined. First, the use of spatial Fourier transforms to analyze video photobleaching measurements is presented. This method extracts diffusion coefficients using all the image data and it does not require that the initial condition created by photobleaching be known. Second, the use of genetic engineering methods coupled with photobleaching analysis is discussed as means to uncover the structural determinants of membrane protein lateral mobility.

Mapping of human chromosome 22 with a panel of somatic cell hybrids

The adenylosuccinate lyase (ADSL) which is essential for generating adenylate, maps to the long arm of chromosome 22. By using a Chinese hamster ovary cell line deficient in ADSL activity, we have constructed a set of 17 somatic cell hybrids containing defined regions of human chromosome 22. This panel was extended with six additional hybrids, obtained in other laboratories using various methods of selection. Southern analysis of the hybrids with 38 chromosome 22 probes defined 14 different subregions which could be linearly organized on the long arm of chromosome 22. The order of the probes thus deduced is fully compatible with their previous localization and with the genetic map. The ADSL gene was further sublocalized between the MB and D22S22. This panel, which enables the rapid assignment of chromosome 22 single copy probes to small subregions, will be an important tool in the construction of a detailed physical map of this part of the genome.

Contraction, Serotonin-Elicited Modulation, and Membrane Currents of Dissociated Fibers of Aplysia Buccal Muscle

Feeding muscles of the buccal mass of Aplysia are innervated by cholinergic and serotonergic neurons. Buccal muscle 15 contracts in response to acetylcholine (ACh). During feeding arousal, ACh-elicited contraction of muscle 15 is potentiated by serotonin (5-HT). This paper demonstrates a dissociated cell preparation of muscle 15 in which cellular mechanisms regulating contraction can be investigated. Dissociated muscle fibers contracted in response to both KCl and ACh. Serotonin (10-6 M) significantly potentiated the shortening caused by both KCl and ACh. Potentiation lasted at least 4 min, similar to potentiation in intact muscles. Four types of currents recorded by patch clamp methods are illustrated. With 540 mM KCl in the patch electrode, stretch-activated channels having a chord conductance of 150 pS are observed in on-cell patches. In whole cell configuration, ACh elicits inward current at a holding potential of -60 mV. With high potassium in the electrode, depolarization elicits an outward current. The voltage-dependent outward current is blocked with cesium in the electrode and 4-aminopyridine and tetraethylammonium outside the cells. The remaining voltage-dependent inward current is calcium dependent. The voltage-dependent inward and outward currents are activated within the range of depolarization produced by ACh and may therefore play roles in regulating contractile responses elicited by ACh.

The investigation of antiepileptic action of qingyangshen (QYS)--effect of QYS on the concentrations of neuropeptides in rat brain

The concentrations of central neuropeptides, somatostatin (SS) and substance-P (SP), were determined in the different brain regions of young-aged male rats after a long-term administration of anticonvulsants Qingyangshen (QYS), Diphenylhydantoin (DPH), and Carbamazepine (CBZ). The results were compared with Pentylenetetrazol (PTZ)-induced seizure model and normal saline-treated controls. No effects of QYS on the concentrations of SS and SP were found in the rats of four-week or eight-week group. Both of DPH and PTZ increased the SS levels in the midbrain of rats in four-week group. DPH, CBZ, and PTZ also increased the SP levels in the cerebral cortex, striatum, and brain stem of rats in eight-week group. Our present data indicated that the central neuropeptides SS and SP were involved in the processes of epilepsy and antiepilepsy. Since QYS did not influence the contents of SS and SP after a long-term administration, it suggested that the anticonvulsant mechanism of QYS may be different from those of DPH and CBZ, i.e. it may be not due to its effect on the central neuropeptide pathway.

Culture and characterization of thymic epithelium from autoimmune NZB and NZB/W mice

Autoimmune NZB and NZB/W mice display early abnormalities in thymus histology, T cell development, and mature T cell function. Abnormalities in the subcapsular/medullary thymic epithelium (TE) can also be inferred from the early disappearance of thymulin from NZB. It has also been reported that NZB thymic epithelial cells do not grow in culture conditions that support the growth of these cells from other strains of mice. In order to study the contribution of TE to the abnormal T cell development and function in NZB and NZB/W mice, we have devised a culture system which supports the growth of TE cells from these mice. The method involves the use of culture vessels coated with extracellular matrix produced by a rat thymic epithelial cell line. TEA3A1, and selective low-calcium, low-serum medium. In addition TEA3A1 cells have been used as an antigen to generate monoclonal antibodies specific for subcapsular/medullary TE. These antibodies, as well as others already available, have been used to show that the culture conditions described here select for cells displaying subcapsular/medullary TE markers, whereas markers for cortical TE and macrophages are absent.

Polarization characteristics of double-clad elliptical fibers

A scalar variational analysis based on a Gaussian approximation of the fundamental mode of a double-clad elliptical fiber with a depressed inner cladding is studied. The polarization properties and graphic results are presented; they are given in terms of three parameters: the ratio of the major axis to the minor axis of the core, the ratio of the inner cladding major axis to the core major axis, and the difference between the core index and the inner cladding index. The variations of both the spot size and the field intensity with core ellipticity are examined. It is shown that high birefringence and dispersion-free orthogonal polarization modes can be obtained within the single-mode region and that the field intensity distribution may be more confined to the fiber center than in a single-clad elliptical fiber.

Preparative slab electrofocusing of methane monooxygenase from a type I methanotroph Methylomonas GYJ3

The isolation and purification of methane monooxygenase from a type I methanotroph Methylomonas GYJ3 to near homogeneity is reported. The isoelectric focusing in flat-bed granulated gels has resolved the methane monooxygenase into three protein components. The specific activity of the enzyme is 198.4 n mol per min per mg protein, degree of purification 4.13-fold. Recovery of the focused proteins is high and elution simple. Several purification steps may be omitted from the previously published scheme by other techniques.

Culture and characterization of thymic epithelium from autoimmune NZB and NZB/W mice

Autoimmune NZB and NZB/W mice display early abnormalities in thymus histology, T cell development, and mature T cell function. Abnormalities in the subcapsular/medullary thymic epithelium (TE) can also be inferred from the early disappearance of thymulin from NZB. It has also been reported that NZB thymic epithelial cells do not grow in culture conditions that support the growth of these cells from other strains of mice. In order to study the contribution of TE to the abnormal T cell development and function in NZB and NZB/W mice, we have devised a culture system which supports the growth of TE cells from these mice. The method involves the use of culture vessels coated with extracellular matrix produced by a rat thymic epithelial cell line. TEA3A1, and selective low-calcium, low-serum medium. In addition TEA3A1 cells have been used as an antigen to generate monoclonal antibodies specific for subcapsular/medullary TE. These antibodies, as well as others already available, have been used to show that the culture conditions described here select for cells displaying subcapsular/medullary TE markers, whereas markers for cortical TE and macrophages are absent.

Fusion of influenza hemagglutinin-expressing fibroblasts with glycophorin-bearing liposomes: role of hemagglutinin surface density

Influenza virus gains access to the cytoplasm of its host cell by means of a fusion event between viral and host cell membrane. Fusion is mediated by the envelope glycoprotein hemagglutinin (HA) and is triggered by low pH. To learn how many hemagglutinin trimers are necessary to cause membrane fusion, we have used two NIH 3T3 fibroblast cell lines that express HA protein at different surface densities. On the basis of quantitations of the number of HA trimers per cell and the relative surface areas of the two cell lines, the HAb-2 cells have a 1.9-fold higher plasma membrane surface density than the GP4F cells. The membrane lateral diffusion coefficient and the mobile fraction for HA is the same for both cell lines. A Scatchard analysis of the binding of glycophorin-bearing liposomes to the cells showed 1700 binding sites for the GP4F cells and 3750 binding sites for the HAb-2 cells, with effectively the same liposome-cell binding constant, about 7 x 10(10) M-1. Binding was specific for glycophorin on the liposomes and HA expressed on the cells. A competition experiment employing toxin-containing and empty liposomes allowed us to quantitate the number of liposomes that fused per cell, which was a small constant fraction of the number of bound liposomes. For the HAb-2 cells, about 1 in every 70 bound liposomes fused and for the GP4F cells about 1 in every 300 bound liposomes fused. Hence, the HAb-2 cells showed 4.4 times more fusion per bound liposome, even though the surface density of HA was only 1.9 times greater. We conclude the following: (i) One HA trimer is not sufficient to induce fusion. (ii) The HA bound to glycophorin is not the HA that induces fusion. That is, even though each HA has a binding and a fusion function, those functions are not performed by the same HA trimer.

The ms1 mutation in soybean: involvement of gametes in crosses with tetraploid soybean

Previous studies indicated that ms1ms1 malesterile female-fertile soybean (Glycine max [L.] Merr.) plants can produce seeds with different ploidy levels. The codominant chlorophyll-deficient mutant y11 was used in attempts to understand the embryo-endosperm relationship in seed production in ms1ms1 plants and to determine the mechanism of gamete formation in the ms1 mutation. Crosses were conducted between yellow-green male-sterile plants (ms1ms1Y11y11) and green fertile tetraploid cultivars (Ms1Ms1Ms1Ms1Y11Y11Y11Y11) in the greenhouse in the summers of 1987 and 1988. A total of 2,007 cross-pollinations were made. Thirty hybrid seeds were obtained, and plants were analyzed for chromosome number, fertility, and color. All the hybrid seedlings were tetraploid and fertile. No triploids were found. Among the 30 F1 plants, 7 were green (Y11Y11Y11Y11), 17 were green-yellow (Y11Y11Y11y11), and 6 were yellow-green (Y11Y11y11y11). The segregation ratio was close to the expected 1 green: 2 green-yellow: 1 yellow-green (X(2) = 0.38; 0.90>p>0.75). From the results of this experiment, we conclude that: (1) triploids were not produced by crossing diploid ms1ms1 soybean plants with tetraploid plants; (2) tetraploid progeny can be produced from these crosses by the fusion of 2n ms1 eggs, or fusion of other 2n gametophyte cells in the embryo sac with a 2x sperm from tetraploid plants; (3) the megaspore mother cell of male-sterile plants undergoes meiotic division without cytokinesis after telophase II and forms more than the normal number of gametes, which can fuse with each other to generate tetraploid gametophyte cells.

[Protective effect of a platelet activating factor antagonist in experimental liver injury]

The present study was conducted to observe the effect of platelet activating factor antagonist-WEB 2086 on the galactosamine/endotoxin (GalN/E)-induced rat liver injury. The results showed that the WEB 2086 (1, 20 or 40 mg/kg, ip) diminished significantly GaIN/E induced elevations of ALT.AST and ACP in the serum (P less than 0.01). Histological changes of the liver were also found to be improved significantly by WEB 2086 administration. Additionally, WEB 2086 decreased significantly the GaIN/E-induced increase of Malondialdehyde (MDA) and Myeloperoxidase (MPO) in the liver (P less than 0.05-0.01), and prevented the decreasing of superoxide dismutase (SOD) in the liver (P less than 0.01). The results obtained with WEB 2086 confirm that platelet activating factor (PAF) has an important role in the pathophysiology of liver injury, PAF-antagonists may have protective effects on liver injury.

[Observation of efficacy of different dialytic therapies in renal transplantation preparation]

Fifty-seven cadaveric renal transplantations in fifty-five cases were analysed of them, thirty cases were prepared by continuous ambulatory peritoneal dialysis (CAPD group); twenty-seven transplantations in twenty-five cases were prepared by hemodialysis (HD group). Our data show that there is no significant difference in the survival duration between CAPD group and HD group; that there is also no significant difference in the survival duration between the two groups treated with the same immunosuppressive drugs, and that patients prepared by CAPD have a low risk of peritonitis after transplantation. It is better not to remove the Tenckhoff catheter until the graft function is stable so that it can be used for the transient peritoneal dialysis in the case of the insult of graft function or for the sampling of the peritoneal effusion for diagnosis of suspectable peritonitis after renal transplantation.

[Effect of monocrotaline on human kidney cells]

The effect of monocrotaline on human kidney cells has been studied by means of monolayer cell culture, cytochemistry and 3H-thymidine incorporation. The result shows that this drug can inhibit cell DNA synthesis, featuring an irreversible damaging action to DNA templet. Also, when the process of glycolysis and saccharide utilization in the cells is inhibited, the amount of lactic acid produced decreases and the pH value becomes higher.

Cell membrane is a major locus for ultraviolet B-induced alterations in accessory cells

In vitro ultraviolet B (UVB) irradiation of human blood monocytes inhibits their accessory cell function for antigen- and mitogen-induced T cell responses. These studies were designed to characterize the nature of the UVB-induced defect in human monocyte accessory cell function. Irradiated monocytes were deficient in their ability to serve as accessory cells for OKT3-induced T cell activation. In vitro exposure of monocytes to 100 J/m2 UVB completely inhibited the T cell proliferative response (51502 cpm, non-UVB-irradiated; 302 cpm, UVB-irradiated). Analysis of the accessory signals altered by UVB indicated that irradiated monocytes were incapable of binding to OKT3 molecules attached to the CD3 antigen on T cells. Provision of an alternative mechanism for binding of OKT3 molecules by attaching anti-mouse IgG to the bottom of microtiter wells completely restored accessory cell function. Further characterization of the defect demonstrated that UVB radiation did not deplete p72 Fc receptors from the surface of irradiated monocytes. However, UVB exposure did produce a dose-dependent decrease in monocyte membrane expression of ICAM-1. It is proposed that UVB radiation leads to changes within the cell membrane that inhibit the ability of monocytes to express selected molecules necessary for binding of T cells.

Interstitial deletion of the short arm of chromosome 20 in arteriohepatic dysplasia (Alagille syndrome)

An autosomal dominant transmission of arteriohepatic dysplasia, or Alagille syndrome, with reduced penetrance and variable expressivity has been suggested from familial pedigrees, but the nature of the genetic defect and its chromosomal localization are not firmly established. We report the case of an 8-year-old boy with arteriohepatic dysplasia, in whom high-resolution chromosome study showed a partial deletion of the short arm of chromosome 20, which encompasses subbands p11.23 to p12.3. In situ hybridization and Southern blotting localized four restriction fragment length polymorphism probes within the deletion and another one distal to the deletion. Because one patient has already been reported to have arteriohepatic dysplasia and deletion of the short arm of chromosome 20, and six additional patients with such a deletion had major features of Alagille syndrome, this syndrome should now be assigned to chromosome 20p.

[Evaluation of antipyrine clearance in chronic liver diseases]

Antipyrine (AP) clearance was determined in 23 cases with liver cirrhosis (LC), 12 with chronic active hepatitis (CAH), 12 with hepatocellular carcinoma (mcHCC), 20 with non-hepatic diseases and 70 healthy controls. ICG Clearance was performed simultaneously in 9 cases of them. The results showed that AP clearance was significantly decreased in patients with LC and moderately decreased in CAH and HCC, its diagnostic sensitivity in LC was significantly higher than that of GPT. The significant positive correlation between the AP and ICG clearance was noted and AP clearance also well correlated with serum albumin level and prothrombin time. It is suggested that AP clearance may be used as a quantitative test to determine the reserve capacity of liver and as a substitutive test for ICG clearance.

Molecular characterization of ataxia telangiectasia T cell clones. II. The clonal inv(14) in ataxia telangiectasia differs from the inv(14) in T cell lymphoma

We compared inversions of chromosome 14 in an ataxia telangiectasia clone and in a malignant T cell line (SUP-T1). The R-banding chromosome analysis showed a clear difference between the distal breakpoint of the two inversions. Fine mapping of the distal breakpoint in the ataxia telangiectasia inv(14) was performed by in situ hybridization. We conclude that this breakpoint is centromeric to the immunoglobulin heavy chain locus and to the D14S1 anonymous locus. Our results favor the existence of an unknown oncogene in band 14q32.1.

Identification of a complex associated with processing and polyadenylation in vitro of herpes simplex virus type 1 thymidine kinase precursor RNA

Cleavage and polyadenylation of substrate RNAs containing the herpes simplex virus type 1 (HSV-1) thymidine kinase (tk) gene polyadenylation signal region were examined in HeLa cell nuclear extract. 3'-End RNA processing was accurate and efficient and required ATP and Mg2+. Cleavage, but not polyadenylation, occurred in the presence of EDTA or when ATP was replaced with 3' dATP (cordycepin) or AMP(CH2)PP, a nonhydrolyzable analog of ATP. Processing in vitro and in vivo showed the same signal element requirements: a series of substrates containing linker scanning, internal deletion, and small insertion mutations was processed with the same relative efficiencies and at the same sites in vitro and in vivo. A complex involved in 3'-end RNA processing was identified by gel mobility shift analysis. This complex formed rapidly, reached a maximum level after 20 to 30 min, and was much reduced after 2 h. Very little complex was formed at 0 degree C or with substrates lacking a polyadenylation signal. Entry of 32P-labeled tk substrate into the complex could be prevented by addition of excess 35S-labeled tk or adenovirus L3 precursor RNAs. Competition was not observed with tk RNAs lacking a complete polyadenylation signal.

The fragile X site in somatic cell hybrids: an approach for molecular cloning of fragile sites

Fragile X syndrome is a common form of mental retardation associated with a fragile site on the human X chromosome. Although fragility at this site is usually evident as a nonstaining chromatid gap, it remains unclear whether or not actual chromosomal breakage occurs. By means of somatic cell hybrids containing either a normal human X or a fragile X chromosome and utilizing two genes that flank the fragile site as markers of chromosome integrity, segregation of these markers was shown to be more frequent if they encompass the fragile site under appropriate culture conditions. Hybrid cells that reveal marker segregation were found to contain rearranged X chromosomes involving the region at or near the fragile site, thus demonstrating true chromosomal breakage within this area. Two independent translocation chromosomes were identified involving a rodent chromosome joined to the human X at the location of the fragile site. DNA analysis of closely linked, flanking loci was consistent with the position of the breakpoint being at or very near the fragile X site. Fragility at the translocation junctions was observed in both hybrids, but at significantly lower frequencies than that seen in the intact X of the parental hybrid. This observation suggests that the human portion of the junctional DNA may contain part of a repeated fragility sequence. Since the translocation junctions join heterologous DNA, the molecular cloning of the fragile X sequence should now be possible.

Fine-structure analysis of the processing and polyadenylation region of the herpes simplex virus type 1 thymidine kinase gene by using linker scanning, internal deletion, and insertion mutations

Most eucaryotic mRNAs are polyadenylated. In higher eucaryotes, the sequence AATAAA is located 7 to 30 base pairs (bp) upstream from the site of processing and polyadenylation and is a critical part of the signal for processing and polyadenylation. Efficient cleavage and polyadenylation also require sequences downstream of polyadenylation sites. The herpes simplex virus type 1 thymidine kinase (tk) gene contains two copies of the AATAAA hexanucleotide and a GT box (18 of 19 consecutive residues are G or T) previously shown to be required for efficient processing and polyadenylation of tk mRNA (C. N. Cole and T. P. Stacy, Mol. Cell. Biol., 5:2104-2113). To define further the sequence requirements for efficient polyadenylation, we prepared linker scanning, internal deletion, and small insertion mutations in the polyadenylation region of the tk gene. These mutations were analyzed by S1 nuclease protection analysis of cytoplasmic RNA isolated from transfected Cos-1 monkey kidney cells. When the proximal AATAAA was deleted, no tk mRNA polyadenylated in the normal region was detected, whereas replacement of the second AATAAA with an XbaI linker had no effect on polyadenylation. When various portions of the GT box were replaced with linker, the amount of tk mRNA produced was reduced to 23 to 82% of the normal amount, but polyadenylation in the normal region was never abolished. Thus, no single portion of the GT box was absolutely required. In some cases, extended transcripts, polyadenylated at a cryptic site within pBR322, were detected. A spacing of 6 bp between AATAAA and the GT box was too short for efficient processing and polyadenylation. A spacing of 30 bp appeared to work almost as efficiently as did the wild-type spacing of 18 bp. Taken together, these results indicate that efficient polyadenylation requires both AATAAA and downstream GT-rich sequences. In addition, processing and polyadenylation are affected both qualitatively and quantitatively by sequences at polyadenylation sites and at more distant locations.

The bioenergetics of Golgi apparatus function: evidence for an ATP-dependent proton pump

The energy requirement for the processing of newly-synthesized proteins by the Golgi was examined. Rat liver Golgi preparations enriched more than 100-fold have high ATPase activity that co-purified with the Golgi marker enzyme galactosyl transferase. The ATPase activity was 80% inhibited by dicyclohexylcarbodiimide and may represent a proton pump. Evidence is presented for a functional role of the ATPase in Golgi. First, measurement of [14C]methylamine uptake demonstrated ATP-dependent acidification. Second, inhibition of the ATPase with dicyclohexylcarbodiimide resulted in a 3-fold accumulation of newly-synthesized protein in the Golgi.