Modulation of endogenous ADP-ribosylation in rat brain

Endogenous ADP-ribosylation of proteins was measured in homogenates, membranes, and cytosol from rat brain regions. Several proteins were ADP-ribosylated in homogenates, especially a 49 kDa protein. Sodium nitroprusside, a source of nitric oxide, particularly enhanced the ADP-ribosylation of 47 kDa and 39 kDa proteins. Levels of basal and sodium nitroprusside-stimulated ADP-ribosylated proteins were similar, but not identical, in homogenates from the cerebral cortex, hippocampus, striatum, thalamus and cerebellum. In neonatal cerebral cortex, ADP-ribosylation of an additional 110 kDa protein was detected and this was also enhanced by sodium nitroprusside. ADP-ribosylation of the 110 kDa protein was evident one and two days after birth, but not at five days and later. Each protein demonstrated unique sensitivities to sodium nitroprusside and rates of ADP-ribosylation. Cyclic GMP did not mimic the effects of sodium nitroprusside. Mg2+ inhibited ADP-ribosylation of the 49 kDa and 47 kDa proteins but had a smaller effect on the 39 kDa protein. ADP-ribosylation in the cytosol predominantly affected only a single protein of 39 kDa, and this was stimulated by sodium nitroprusside and by addition of cofactors necessary for activation of nitric oxide synthase. Several proteins in membranes were ADP-ribosylated and the 49 and 47 kDa proteins were released from the membranes coincidentally with ADP-ribosylation. The predominate substrates of endogenous ADP-ribosylation did not appear to be substrates for pertussis toxin-induced ADP-ribosylation. These and previously published results indicate that nitric oxide generated from sodium nitroprusside or endogenous sources may have modulatory effects through regulation of the endogenous ADP-ribosylation of proteins.

Higher rates of amino acid substitution in rodents than in humans

An analysis of 54 protein sequences from humans and rodents (mice or rats), with the chicken as an outgroup, indicates that, from the common ancestor of primates and rodents, 35 of the proteins have evolved faster in the lineage to mouse or rat (rodent lineage) whereas only 12 proteins have evolved faster in the lineage to humans (human lineage). The average rate of amino acid substitution is significantly faster in the rodent lineage than in the human lineage. In addition, the average rate of insertion/deletion is also faster in rodents than in humans and there is a positive correlation between the rate of amino acid substitution and the rate of insertion/deletion in a protein sequence.

Targeting liver tumors by administering liposomal doxorubicin into the hepatic artery

The plasma levels, organ distribution, and in vivo anti-tumor activity of liposomal doxorubicin administered i.v. or i.a. (hepatic) in rats bearing W256 liver tumors were studied. I.a. administration of liposomal doxorubicin resulted in 4-fold and 1.3-fold higher liver tumor and liver parenchyma doxorubicin levels, respectively, than i.v. administration, thus suggesting a more preferential distribution of liposomal doxorubicin into the liver tumor with i.a. administration. By contrast, the heart, spleen, and plasma AUCs were decreased 3.8-, 3.2-, and 16-fold, respectively, after i.a. administration. Cumulative urinary excretion at 8 hr was also 14 times lower in animals that received liposomal doxorubicin i.a. In good correlation with these findings, i.a. administration markedly enhanced the anti-tumor effect of liposomal doxorubicin against liver W256 tumors as measured by tumor growth inhibition 5 days after treatment (-16% for i.a. administration vs. +89% for i.v. administration, p less than or equal to 0.05) and prolongation of survival (ILS: 108% for i.a. administration vs. 26% for i.v. administration, p less than or equal to 0.05). Our results show that i.a. administration of liposomal doxorubicin results in preferential distribution of the anti-tumor agent into the tumor tissue and increased anti-tumor activity, while increasing the cardioprotective effect of the liposome carrier by decreasing the plasma peak and heart-tissue levels of the drug.

Subtypes of substantia nigra dopaminergic neurons revealed by apamin: Autoradiographic and electrophysiological studies

In the intact animal, some substantia nigra dopaminergic neurons exhibit regular, and some exhibit burst firing patterns. In the in vitro slice preparation, however, all dopaminergic neurons exhibit a nonburst firing pattern. Burst firing patterns are thought to be regulated, in part, by a small conductance calcium-activated potassium channel (SK channels). To test whether SK channels reside within the midbrain dopaminergic cell regions of the mouse, receptor autoradiographic experiments were conducted with the SK channel antagonist, 125I-apamin. To determine whether SK channels play a role in burst firing pattern generation in substantia nigra dopaminergic neurons, changes in firing patterns of these cells were examined in the in vitro slice preparation following apamin superfusion (1-1000 nM). It was demonstrated that a) specific binding of radiolabeled apamin was found within the dopaminergic cell regions of the substantia nigra pars compacta, and ventral tegmental area (2.7-4.7 fmol/mg tissue); b) the firing patterns of less than half of the dopaminergic neurons were changed from a regular pattern to that of a burster with concentrations as low as 1 nM, but the firing patterns of many neurons were not changed by the drug; and c) blockade of the SK channel did not interfere with the inhibitory effects of dopamine on dopaminergic neuronal impulse flow, indicating that the known hyperpolarizing effects mediated by this dopamine receptor are not importantly mediated via the SK channel.

Seizures increase acetylcholine and choline concentrations in rat brain regions

Seizures induced by three convulsant treatments produced differential effects on the concentration of acetylcholine in rat brain. Status epilepticus induced by (i) coadministration of lithium and pilocarpine caused massive increases in the concentration of acetylcholine in the cerebral cortex and hippocampus, (ii) a high dose of pilocarpine did not cause an increase of acetylcholine, and (iii) kainate increased acetylcholine, but the magnitude was lower than with the lithium/pilocarpine model. The finding that the acetylcholine concentration increases in two models of status epilepticus in the cortex and hippocampus is in direct contrast with many in vitro reports in which excessive stimulation causes depletion of acetylcholine. The concentration of choline increased during seizures with all three models. This is likely to be due to calcium- and agonist-induced activation of phospholipase C and/or D activity causing cleavage of choline-containing lipids. The excessive acetylcholine present during status epilepticus induced by lithium and pilocarpine was responsive to pharmacological manipulation. Atropine tended to decrease acetylcholine, similar to its effects in controls. The N-methyl-D-aspartate (NMDA) receptor antagonist, MK-801, reduced the excessive concentration of acetylcholine, especially in the cortex. Inhibition of choline uptake by hemicholinium-3 (HC-3) administered icv reduced the acetylcholine concentration in controls and when given to rats during status epilepticus. These results demonstrate that the rat brain concentrations of acetylcholine and choline can increase during status epilepticus. The accumulated acetylcholine was not in a static, inactive compartment, but was actively turning-over and was responsive to drug treatments. Excessive concentrations of acetylcholine and/or choline may play a role in seizure maintenance and in the neuronal damage and lethality associated with status epilepticus.

Amphetamine-induced and spontaneous release of dopamine from A9 and A10 cell dendrites: an in vitro electrophysiological study in the mouse

d-Amphetamine (d-AMP) is a potent releaser of dopamine (DA), and its central nervous system stimulant action is mediated primarily through its effect on the substantia nigra and ventral tegmental area dopaminergic neurons (nuclei A9 and A10, respectively). The purpose of the present experiment was to use electrophysiological techniques to examine dendritic release of DA in the in vitro slice preparation, and determine whether: (1) d-AMP inhibits the firing rates of both A9 and A10 cells; (2) the d-AMP-induced inhibition is mediated via the dendritic release of DA; and (3) there is spontaneous dendritic release of DA. Superfusion with d-AMP (2-100 microM) produced identical inhibitory dose-response curves for A9 and A10 cells, and a dose of 6.25 microM caused more than 50% inhibition in the cell firing rates. The d-AMP-induced inhibition was attenuated by blocking DA synthesis. Either D2 receptor blockade (sulpiride, 1 microM), or DA synthesis inhibition (alpha-methylparatyrosine, 50 microM) resulted in a marked increase in the firing rates of dopaminergic cells. These data suggest that d-AMP comparably releases DA from both A9 and A10 cell dendrites, that it releases newly-synthesized DA to inhibit cell firing, and that DA is tonically released to regulate cell firing rates via interactions with inhibitory D2 autoreceptors.

Histamine is a transient marker of small intestinal injury induced by luminal acetic acid and casein

We compared the time course of histamine release with other markers of intestinal injury in a rabbit model of necrotizing enterocolitis. Injury was induced by luminal acetic acid (200 mM) and casein (10 mg/ml) and experiments terminated after 45 min or 3 hr. Compared to saline controls there was a significant elevation of epithelial permeability (51Cr-EDTA clearance) and luminal protein levels at both time points. Luminal fluid histamine levels were approximately 120-fold greater than saline controls at 45 min but were indistinguishable from control values at 3 hr. We conclude that although mast cell activation is a characteristic of this model, elevations in histamine levels are transient.

Misoprostol attenuates acetic acid-induced damage in rabbit distal small intestine

The influence of misoprostol pretreatment (100 micrograms/loop intraluminally) on small intestinal damage induced by acetic acid was evaluated in anesthetized rabbits. In this model injury was induced by intraluminal administration into loops of distal small intestine, of a solution of calcium gluconate (50 mg/ml) and acetic (200 mM). After 3 hr damage was associated with increase in loop fluid volume, loop fluid protein levels and epithelial permeability to 51Cr-EDTA, all of which were attenuated by misoprostol pretreatment. Similar protective effects were noted 45 min after the insult, suggesting that misoprostol may be therapeutically useful in conditions where the epithelial barrier is compromised.

Potential role of histamine monochloramine in a rabbit model of ileitis

Histamine chloramines, derived from the chlorination of histamine by granulocyte-derived oxidants, are potential mediators of intestinal injury and dysfunction in states of atopy or inflammation. We assessed the ability of histamine monochloramine to increase epithelial permeability in rabbit distal small intestine and determined whether the conditions for histamine chloramine formation are favorable in a rabbit model of ileitis. Epithelial permeability, quantified by the blood-to-lumen clearance of 51Cr-labeled ethylenediaminetetraacetic acid, was enhanced by luminal perfusion with either histamine or histamine monochloramine (10 microM), although the latter was twice as effective (p less than 0.05). In a rabbit model of ileitis induced by a luminal solution of acetic acid (200 mM) and casein (10 mg/ml) there was a marked increase in epithelial permeability and in the release into the lumen of histamine, myeloperoxidase, 6-keto-prostaglandin F1 alpha and protein. These results suggest that the conditions are favorable for histamine chloramine formation and that histamine and histamine chloramine may impair the integrity of the epithelial barrier.

Nucleus A10 dopaminergic neurons in inbred mouse strains: firing rate and autoreceptor sensitivity are independent of the number of cells in the nucleus

Inbred mouse strains have different numbers of midbrain dopaminergic neurons; for example, BALB/cJ mice have 20-25% more neurons than CBA/J mice. As the number of cells decrease, for example in Parkinson's disease and in animals with midbrain dopaminergic cell lesions, the activity of their remaining cells increases. The purpose of the present experiment was to determine whether the functional properties of dopaminergic neurons in the ventral tegmental area (nucleus A10) differ in inbred mouse strains which possess different numbers of cells. The firing rate and autoreceptor sensitivity of A10 dopaminergic cells were examined in the in vitro slice preparation in BALB/cJ, C3H/HeJ, CBA/J, and DBA/2J mouse strains. It was observed that the autoreceptors on mouse dopaminergic neurons exhibit pharmacological properties of dopamine autoreceptors; activation of the autoreceptor produced a marked inhibition (50-70%) in cell firing rate by quinpirole (10(-8) M), LY-141865 (10(-7) M), (+)-3-(3-hydroxyphenyl)-N-n-propyl-piperidine (10(-6) M), propyl-norapomorphine (10(-5) M) and dopamine (10(-4) M), and this inhibition was blocked or reversed by specific dopamine D2 receptor antagonists [(-) sulpiride and spiroperidol, 10(-6) M]. The baseline firing rates of the A10 cells did not differ among the four inbred strains [range 2.5 +/- 0.2 (C3H/HeJ)-3.4 +/- 0.3 (CBA/J) spikes/s +/- SEM], and there was no significant difference in autoreceptor sensitivity among the mouse strains as assessed either by superfused dopamine (inhibitory dose 50% approximately 150 microM), or by superfused quinpirole (inhibitory dose 50% approximately 10 nM).(ABSTRACT TRUNCATED AT 250 WORDS)

[Intermittent exotropia associated with accommodative esotropia]

Intermittent exotropia associated with accommodative esotropia is a rare particular type of strabismus. 8 cases of XT-ET were presented here. The clinical features of them were summarized as follows: 1. The age of onset was early. 2. The initial symptom was esotropia, exotropia was observed by doctor. 3. The most patients (6/8) associated high or medium hyperopia. 4. The AC/A rate were normal or lower than normal. 5. The angle of deviation varied with the examination, exotropia 30 degrees-15 degrees<-->orthophoria<-->esotropia 15 degrees-30 degrees. 6. The esotropia can be corrected with spectacles. The visual-vestibular interaction examination for eye movement were examined in 3 cases, but have no regular expression yet. Finally, the incidence (0.4%, 8/21 58) and treatment for this disease were discussed.

Exaggerated intestinal histamine release by casein and casein hydrolysate but not whey hydrolysate

Loops of rabbit distal small intestine received luminal acetic acid (pH 4.0) alone or in combination with bovine casein, casein hydrolysate, or whey hydrolysate. Blood-to-lumen movement of 51Cr-labeled ethylenediaminetetraacetic acid (EDTA) (an index of epithelial permeability) and loop fluid histamine levels were quantified after 45 min. Luminal acetic acid caused a marked increase in 51Cr-EDTA accumulation which was not modified by the addition of bovine casein or hydrolysates by of casein or whey. However, acetic acid-induced histamine release was potentiated by casein and casein hydrolysate (six- and four-fold respectively) but was not altered by whey hydrolysate. Casein hydrolysate-dependent histamine release was evident in naloxone-pretreated rabbits, suggesting that beta-casomorphins were not solely responsible. We conclude that luminal casein or casein hydrolysate, but not whey hydrolysate. can activate intestinal mast cells under conditions of enhanced epithelial permeability. This effect appears to involve components other than beta-casomorphins.

Affinity chromatography of Escherichia coli (m5U54)-methyltransferase on tRNA-agarose

tRNA-agarose was prepared by condensing periodate-oxidized tRNA to an agarose matrix containing hydrazide functional groups. The tRNA-agarose was used to take partially purified tRNA (m5U54)-methyltransferase to homogeneity. The method is simple and reproducible and gives high yields.

[The visual-vestibular interaction in normal subjects]

Full-field optokinetic nystagmus (OKN) at constant speed of 40 0/s and 60 0/s, vestibular ocular reflex (VOR) (sinusoidal 0.2 Hz, 60 0/s peak velocity) with different background (light and dark) and VOR-fix were observed in 72 normal subjects (144 normal eyes). The gain, FCV and DP of OKN, VVOR, VOR were also analysed. The gain of OKN is reduced accompanied with stimulation increasing, while the FCV is increased. The gain of VVOR is 1.08 +/- 0.09 (X +/- SD), while the gain of VOR is 0.64 +/- 0.09. The FCV of VOR is much reduced than that of VVOR. The FCV in the groups under 30 years of age are much faster than the groups above 30 years of age. The VOR--fix gain is 0.05 +/- 0.04. The DP of OKN, VVOR, and VOR are 0.05 +/- 0.04. The results showed an co-operation between visual and vestibular systems and the results also suggested that the series methods of visual-vestibular interaction (OKN, VVOR, VOR, VOR-fix) might be useful in eye movement examination.

[The visual-vestibular interaction in normal subjects]

Full-field optokinetic nystagmus (OKN) at constant speed of 40 degrees/s and 60 degrees/s, vestibular ocular reflex (VOR) (sinusoidal 0.2Hz, 60 degrees/s peak velocity) with different background (light and dark) and VOR-fix were observed in 72 normal subjects (144 normal eyes). The gain, FCV and DP of OKN, VVOR, VOR were also analysed. The gain of OKN is reduced accompanied with stimulation increasing, while the FCV is increased. The gain of VVOR is 1.08 +/- 0.09(mean +/- SD), while the gain of VOR is 0.64 +/- 0.09. The FCV of VOR is much reduced than that of VVOR. The FCV in the groups under 30 years of age are much faster than the groups above 30 years of age. The VOR-fix gain is 0.05 +/- 0.04. The DP of OKN, VVOR, and VOR are 0.05 +/- 0.04. The results showed an co-operation between visual and vestibular systems and the results also suggested that the series methods of visual-vestibular interaction (OKN, VVOR, VOR, VOR-fix) might be useful in eye movement examination.

Microvascular exchange during burn injury: II. Formulation and validation of a mathematical model

A mathematical model of microvascular exchange in the rat following a burn injury was developed by extending an existing model of normal microvascular exchange to include perturbations characteristic of burn injuries without fluid resuscitation. The changes anticipated for small (10% body surface area) and large (40% body surface area) burns are incorporated systematically into the model until there is no improvement in the statistical fit of the simulation predictions with the experimental data of Lund and Reed (Circulatory Shock 20:91-104, 1986). The "best fit" perturbations for the small burn include the experimentally measured changes in mean arterial pressure and injured tissue pressure as well as changes to plasma protein and fluid transport coefficients in the injured tissue. The larger burn "best fit" simulation required changes to the plasma protein transport coefficients in the intact tissues as well as all of the changes listed above. The simulation results are compared with the available experimental information on burn injuries as well as with the specific data of Lund and Reed (Circulatory Shock 20:91-104, 1986).

Microvascular exchange during burn injury: III. Implications of the model

The present work investigates the implications of the predictions of a dynamic mathematical model of microvascular exchange following a nonresuscitated burn injury in a rat (Bert et al.: Circulatory Shock 28:199-219, 1989). Transport coefficients, transmicrovascular pressures, and the resultant fluid and protein fluxes were examined in order to assess their quantitative importance to the dynamic behavior of small (10% body surface area) and large (40% body surface area) burns. Edema accumulation in the injured tissue is dependent not only on events occurring in that tissue but is influenced strongly by interaction with the plasma and the noninjured tissue compartments.

An analysis of intermediate fertility variables in Shanghai, Hebei and Shaanxi

"On the basis of the data from China's first thorough survey on fertility [conducted in 1985], organized by the State Statistical Bureau, this study will analyze...intermediate fertility variables in Shanghai, Hebei and Shaanxi according to the [Bongaarts] Model. It will also provide a general survey of the model."

The influence of proglumide, a putative CCK antagonist, on cerebral ischemia in gerbil

Studies were conducted to clarify the possible role of CCK in cerebral ischemia and to evaluate the effects of proglumide, a competitive and reversible CCK antagonist, as a potential therapeutic or prophylactic tool in the treatment of cerebral ischemia. Proglumide at the doses of 10, 50 and 150 mg/kg was administered to gerbils before unilateral carotid ligation, and its effect on stroke index score, incidence and mortality rate was observed. Our results show that proglumide injected prior to carotid ligation at the dose of 150 mg/kg significantly reduces both incidence and mortality rate and changes the distribution of the stroke index score in gerbils. There was a significant inverse relationship between the dose of proglumide and both incidence and mortality: the greater the injection dose of proglumide, the lower the incidence and mortality. These results suggest that CCK may be involved in the pathological processes of cerebral ischemia and proglumide or related compounds prove to be effective in the pharmacological prophylaxis of ischemic brain damage.

Studies on immunopathogenesis in epidemic hemorrhagic fever: sequential observations on activation of the first complement component in sera from patients with epidemic hemorrhagic fever

Sequential measurements of activation of the 1st component of complement (C1) in the sera of 29 patients hospitalized with epidemic hemorrhagic fever (EHF) were performed according to a method recently developed. These patients were treated with supportive, routine therapy, but not immunosuppressive agents. This paper describes the kinetic observations on the activation of C1 in the 29 cases. The data confirm that an apparently increased extent of activation occurred in their sera. It was found that the more severely ill the patients were, the more apparent the activation. Additionally, beginning with the 15th day of disease, the extent of C1 activation diminished in most of the moderate and severe types of patients, but not in those with moribund illness and fatal ones. On the basis of the study, it may be reasonably concluded that C1 activation was correlated well with the severity and clinical course of EHF, indicating that the classical C pathway was activated in these patients. We feel that our findings are important to an understanding and elucidation of the immunopathogenetic mechanisms of EHF.

Studies on immunopathogenesis in epidemic hemorrhagic fever: sequential observations on activation of the first complement component in sera from patients with epidemic hemorrhagic fever

Sequential measurements of activation of the 1st component of complement (C1) in the sera of 29 patients hospitalized with epidemic hemorrhagic fever (EHF) were performed according to a method recently developed. These patients were treated with supportive, routine therapy, but not immunosuppressive agents. This paper describes the kinetic observations on the activation of C1 in the 29 cases. The data confirm that an apparently increased extent of activation occurred in their sera. It was found that the more severely ill the patients were, the more apparent the activation. Additionally, beginning with the 15th day of disease, the extent of C1 activation diminished in most of the moderate and severe types of patients, but not in those with moribund illness and fatal ones. On the basis of the study, it may be reasonably concluded that C1 activation was correlated well with the severity and clinical course of EHF, indicating that the classical C pathway was activated in these patients. We feel that our findings are important to an understanding and elucidation of the immunopathogenetic mechanisms of EHF.