[Gama hydroxybutyrate sodium (gama-OH)-diazepam combined anaesthesia for cleft palate repair in children below 3 years old]

To investigate the effect of Gama-OH-Diazepam combined anaesthesia for cleft palate repair in children below 3 years old.

METHODS

Heart rates were measured in 120 children at induction, at 5 minutes after endotrocheal intubation, at finishing of operation, and at 5 minutes after extubation. In addition, changes of SpO2 was randomly detected in 10 children.

RESULTS

Heart rate decreased after intubation, increased when operation was completed and decreased again after extubation. SpO2 of all stages were in the normal range.

CONCLUSIONS

This method of anaesthesia is suitable for cleft palate repair in children below 3 years old, with the advantages of little effect on the children's circulatory and respiratory systems, and being easy to perform and control.

In vivo transfer of a foreign gene to keratinocytes using the hemagglutinating virus of Japan-liposome method

The hemagglutinating virus of Japan (HVJ)-liposome method involves the entrapment of DNA and nuclear protein within liposomes and the use of HVJ to enhance liposome fusion with cell membranes. This method has been used successfully for in vivo gene transfer to various types of tissue. In this study, we investigated whether this method transfers genes effectively to normal and malignantly transformed keratinocytes in vivo. We applied HVJ-liposome complex (HLC) containing the beta-galactosidase gene to the tape-stripped skin of hairless rats and detected the enzyme activity in the keratinocytes of the treated skin. Comparison of this method with the naked DNA injection method, which was shown recently to be useful for in vivo gene transfer to keratinocytes, demonstrated that the transfer efficiency of the latter was about 5 times higher than that of the former. We assessed the efficacy of the HVJ-liposome method for gene transfer to transformed keratinocytes by examining the effect of HLC containing the herpes simplex virus thymidine kinase gene on the growth of mouse squamous cell carcinomas. Local injection of HLC into the tumors followed by administration of ganciclovir to mice resulted in tumor growth inhibition. These results indicate that the HVJ-liposome method is suitable for in vivo gene transfer to keratinocytes; also that this method may prove a good tool for basic research into keratinocyte biology and future keratinocyte gene therapy.

Hemorrhage induces acute cardioadaptation to ischemia-reperfusion by an alpha1-adrenoceptor-mediated, protein synthesis-independent mechanism

Hemorrhage and resuscitation (H-R) has been recognized as an exclusively destructive process that results in multiple organ dysfunction. Although it is well established that endogenous adaptation mechanisms exist, it is unknown whether H-R induces endogenous adaptive/protective mechanisms. Furthermore, alpha1-adrenoceptors and de novo protein synthesis have been variably implicated in myocardial adaptation responses. This study tests the hypothesis that H-R results in myocardial adaptation by a mechanism mediated by alpha1-adrenoceptors and requiring de novo protein synthesis. The aims of the present study were to determine 1) whether H-R stress results in acute cardioadaptation to subsequent global, normothermic ischemia-reperfusion (I-R); 2) whether H-R-induced endogenous adaptation is mediated by alpha1-adrenoceptors; and 3) whether H-R-induced endogenous adaptation requires de novo protein synthesis. Rats were hemorrhaged and resuscitated, sham operated, or neither, with and without prior alpha1-adrenoceptor or protein synthesis inhibition. Hearts were then isolated and subjected to a second insult consisting of global, normothermic I-R (20 min ischemia-40 min reperfusion). The results show that antecedent H-R improved post-I-R left ventricular developed pressure, compliance, coronary flow, and decreased reperfusion creatine kinase loss (P < 0.05, analysis of variance with Bonferroni-Dunn). H-R-induced adaptation was abolished by prior alpha1-adrenoceptor blockade (prazosin, 0.5 mg/kg ip); however, inhibition of de novo protein synthesis (cyclohexamide, 1.0 mg/kg ip) did not affect H-R-induced acute adaptation. This study constitutes the initial demonstration that H-R induces endogenous cardioadaptation, which is mediated by an alpha1-adrenergic signaling pathway, but does not require de novo protein synthesis.

Nitric oxide synthase is not involved in cardiac contractile dysfunction in a rat model of endotoxemia without shock

Endotoxin and proinflammatory cytokines induce nitric oxide synthase (NOS), and nitric oxide (NO) plays an important role in promoting endotoxin shock. However, the role of NOS in endotoxemic cardiac contractile dysfunction is not defined. To determine whether endotoxemic cardiac contractile dysfunction involves NOS, the present study used a rat model of endotoxemia without shock and examined the effects of glucocorticoids (dexamethasone, a potent inhibitor of inducible NOS, iNOS, expression), isoform nonselective NOS inhibitor (NG-monomethyl-L-arginine, L-NMA) and iNOS selective inhibitor (S-methylisothiourea sulfate, SMT) on cardiac contractile dysfunction. A sublethal dose of endotoxin (from Salmonella typhimurium, .5 mg/kg, i.p.) was given to adult rats, and left ventricular developed pressure (LVDP) examined by Langendorff technique was attenuated in hearts isolated at 4 or 6 h (66.7 +/- 3.4 and 60.3 +/- 5.5 mmHg, respectively, p < .05 vs. 102 +/- 2.4 mmHg in saline control) after endotoxin treatment. Pretreatment of rats with dexamethasone (4.0 mg/kg, i.v., -30 min) partially abolished endotoxin-induced contractile dysfunction at 6 h (LVDP 87.6 +/- 6.8 mmHg, p < .05 vs. endotoxin alone at 6 h). However, pretreatment with L-NMA (30 mg/kg, i.v., -5 min) or SMT (5.0 mg/kg, i.v., -1 min) failed to prevent the contractile dysfunction. Moreover, infusion of L-NMA or SMT in vitro could not restore contractile function in hearts isolated at 6 h after endotoxin treatment. In contrast, inhibition of NOS with L-NMA or SMT in vitro further attenuated coronary flow in endotoxin-treated hearts. Thus, endotoxemic cardiac contractile dysfunction in this non-shock rat model may not involve NOS, and inhibition of NOS may deteriorate coronary perfusion in endotoxemic heart.

[The frequencies of the vitamin D receptor gene alleles in adults of Han nationality in Beijing area]

Vitamin D receptor (VDR) gene is considered as one of candidate genes related to the genetic basis of bone and mineral metabolism. In order to determine VDR genotypes, we analysed the polymorphisms, or genotypes of Bsm I, Apa I, and Taq I restriction enzymes, by PCR technique in 223 unrelated healthy adults of Han nationality in Beijing area. Some of the VDR genotypes were also confirmed by Southern blotting analysis. We discovered that Chinese had high frequencies of b, a, T alleles, as high as 95%, 75%, and 95% respectively, which were different from those in Caucasians and Japanese, but similar to those in Koreans (P > 0.05). This difference gave us further insight into the different pathogeny of osteoporosis in various ethnics.

[Antioxidative effect of constituents of herba Epimedii (ESPS)]

Herba Epimedii is a traditional Yang invigorating Chinese herb widely used in clinic. The experimental results have shown that ESPS obviously increases superoxide dismutase(SOD) activity of red cells and liver in aged mice and rats, and increases glutathione peroxidase(GSH-Px) activity of red cells in aged mice. On the other hand, ESPS obviously helps to reduce the content of serum and liver lipoperoxide(LPO) in aged mice and rats, as well as the content of lipofuscin(LF) in cardiac muscle of aged mice. The results suggest that being helpful in increasing SOD and GSH-Px activities and inhibiting the formation of LPO and LF, ESPS may be a good antiageing agent.

[Normal spinal changes of bone mineral density in 445 individuals: assessment by quantitative computed tomography]

Spinal BMD was measured by QCT in 445 normal individuals aged 10-80 including 190 males and 255 females, which were divided into age-groups by every ten years. Statistic results showed that peak bone mass reached at 10-19 age-group for both male and female and that BMD assessed by QCT in females was not lower than that in males and BMD declined with increasing age. In females, BMD results in this study were different from those in USA. An acceleration bone loss was predominantly shown in the period after 40-49 age group. Among many factors related to bone loss, we consider that estrogen change may play a most important role for the remarkable bone loss in our country.

Neutrophil depletion attenuates endotoxin-induced dysfunction of cGMP-mediated pulmonary vasorelaxation

The effect of neutrophil depletion on endotoxin-induced dysfunction of guanosine 3',5'-cyclic monophosphate (cGMP)-mediated pulmonary vasorelaxation was studied in rats. Two mechanisms of neutrophil depletion were used: vinblastine (0.75 mg/kg iv) and rabbit anti-rat neutrophil antiserum (0.15 ml iv). Concentration-response curves were generated (10(-9) to 10(-6) M) for acetylcholine (ACh), A-23187, and sodium nitroprusside (SNP) in isolated pulmonary arterial rings preconstricted with phenylephrine 6 h after endotoxin (20 mg/kg ip). Absolute neutrophil count was significantly lowered from 1,050 +/- 206 (neutrophils/ml; mean +/- SE) in controls to 100 +/- 41 by vinblastine and to 50 +/- 29 by antiserum. Endotoxin produced histological evidence of pulmonary vascular endothelial damage and significantly increased lung neutrophil accumulation (myeloperoxidase assay, 5.1 +/- 0 vs. 1.2 +/- 0.1 in controls; 0.1 +/- 0.1 and 0.8 +/- 0.0 U/g lung wt after endotoxin in neutrophil-depleted rats by vinblastine and antiserum, respectively). Endotoxin produced significant impairment of endothelium-dependent cGMP-mediated pulmonary vasorelaxation by receptor-dependent (ACh) and -independent (A-23187) pathways as well as endothelium-independent relaxation (SNP). Neutrophil depletion significantly attenuated the endotoxin-induced impairment of all three of these mechanisms. We conclude that neutrophils contribute to endotoxin-induced impairment of GMP-mediated pulmonary vasorelaxation.

[Effect of active constituents of Herba Epimedii on hypothalamic monoamine neurotransmitters and other brain functions in aging rats]

The active constituents of Herba Epimedii can raise the hypothalamic monoamine neurotransmitters levels in aging male rats and improve the learning and memory in aging rats and mice. It can also inhibit the activities of AchE both in brain tissues and whole blood in mice.

Endotoxin induces cardiac HSP70 and resistance to endotoxemic myocardial depression in rats

Endotoxin (bacterial lipopolysaccharide, LPS) depresses myocardial function. However, heat shock and sublethal LPS can confer cardiac resistance to postischemic dysfunction. We hypothesized that a prior exposure to LPS stress induces the expression of cardiac heat shock protein 70 (HSP70) and resistance to endotoxemic myocardial depression. Moreover, induction of HSP70 by hyperthermia should also increase cardiac resistance to LPS toxicity. LPS (500 micrograms/kg ip) depressed rat left ventricular developed pressure (LVDP) maximally at 6 h (58.4 +/- 3.72 vs. 101 +/- 1.46 mmHg in saline control, P < 0.01), and myocardial contractile function recovered at 24 h. In rats pretreated with LPS 24 h earlier, subsequent LPS exposure did not depress LVDP (97.0 +/- 3.53 mmHg at 6 h, P < 0.01 vs. single exposure). Both LPS and hyperthermia (42 degrees C, 15 min) induced HSP72 mainly in the cardiac interstitial cells, including macrophages at 24 h after treatment. When hyperthermia-pretreated animals were similarly challenged with LPS, myocardial depression at 6 h was partially abrogated (LVDP 80.1 +/- 5.67 vs. 62.2 +/- 4.91 mmHg in sham+LPS group, P < 0.01). We conclude that LPS induces HSP70 in rat heart and that an exposure to LPS or heat stress confers cardiac resistance to endotoxemic myocardial depression.

Clinical application of Omniplane transesophageal echocardiography

One hundred and twenty-four patients with heart disease (75 cases of rheumatic heart disease, 26 cases of congenital heart disease, 13 cases of aortic disease and 10 cases of other disease) were examined by Omniplane transesophageal echocardiography (TEE). The result showed that Omniplane TEE transducer can be rotated from 0 degree to 180 degrees in probe and had the advantages of broader scope, obtaining more information, less stimulation to esophagus and easy to manipulate. It suggests that Omniplane TEE is a efficient technique in clinical diagnosis and can be extensively used in the future.

Norepinephrine-induced sustained myocardial adaptation to ischemia is dependent on alpha 1-adrenoceptors and protein synthesis

The authors have shown that stimulation of cardiac alpha 1-adrenoceptors confers immediate cardioprotection in the isolated rat heart against post-ischemic dysfunction, and have recently demonstrated that in vivo treatment of rats with norepinephrine (NE) induces cardiac heat shock protein 72 and myocardial adaptation to ischemia 24 h after treatment. To characterize the delayed myocardial adaptive response induced by NE further, the present study examined its time course and effects of adrenoceptor antagonism and protein synthesis inhibition on this adaptive response during optimal myocardial protection. Rats were treated with NE (3.1 mumol/kg, i.p.) or normal saline (0.4 ml, i.p.), and hearts isolated at 2, 4, 24, 72 and 168 h after injection. Isolated hearts were subjected to 25 min of normothermic global ischemia and 40 min of reperfusion by the Langendorff technique, and left ventricular developed pressure (LVDP) was assessed. There was no difference in baseline LVDP among groups. Post-ischemic LVDP recovered to 44.7 +/- 2.1 mmHg in pooled saline control. LVDP was significantly improved in hearts isolated at 4, 24 and 72 h after injection of NE (66.3 +/- 3.8, 68.6 +/- 2.7 and 72.6 +/- 8.3 mmHg, respectively, P < 0.05 v control) but not in hearts isolated at 2 or 168 h. Effects of antecedent adrenoceptor antagonism and protein synthesis inhibition were examined in hearts isolated at 72 h after NE treatment. Prazosin pretreatment (2.4 mumol/kg, i.p.) abolished the delayed myocardial adaptive response induced by NE at 72 h (post-ischemic LVDP 48.3 +/- 6.1 mmHg, P > 0.05 v control) while propranolol pretreatment (3.4 mumol/kg, i.p.) had no effect (post-ischemic LVDP 67.3 +/- 3.7 mmHg, P < 0.05 v control). Cycloheximide pretreatment (3.6 mumol/kg, i.p.) also abolished the beneficial effect of NE at 72 h (post-ischemic LVDP 50.2 +/- 6.0 mmHg, P > 0.05 v control). In conclusion, administration of NE to rats can induce delayed and sustained cardioprotection against post-ischemic myocardial dysfunction. NE-induced myocardial adaptation to ischemia at 72 h is mediated by alpha 1-adrenoceptors and appears to require protein synthesis.

A novel keratin K5 gene mutation in Dowling-Meara epidermolysis bullosa simplex

We examined keratin K14 and K5 genes mutation in a Japanese Dowling-Meara epidermolysis bullosa simplex patient with severe generalized blistering and erosions at birth. The patient had a C to T transition at the first position of codon 174 in the keratin K5 gene, which resulted in a Leu->Phe substitution at the highly conserved 1A domain in keratin K5. Thus, our results revealed a novel mutation in the helix initiation peptide of keratin K5.

Norepinephrine induces cardiac heat shock protein 70 and delayed cardioprotection in the rat through alpha 1 adrenoceptors

OBJECTIVE

Previous studies have demonstrated that norepinephrine (NE) confers immediate cardioprotection against ischemia and reperfusion injuries. The present study tests the hypothesis that in vivo treatment with NE induces delayed cardioprotection against postischemic dysfunction in the rat heart which is associated with expression of c-fos and heat shock protein (HSP) 70 in the myocardium.

METHODS

Rats were treated with NE (3.1 mumol/kg, ip) and hearts isolated and perfused with a modified Langendorff technique 2 or 24 h after injection. Left ventricular developed pressure (LVDP) and left ventricular end-diastolic pressure (LVEDP) were recorded during 25 min normothermic global ischemia and 40 min reperfusion. Total RNA was extracted from left ventricular tissue at various time points and Northern hybridization was applied to detect c-fos and HSP70 mRNAs. Expression and distribution of c-fos and HSP72 proteins in the myocardium were examined by immunohistochemical staining.

RESULTS

In vivo NE treatment improved postischemic recovery of both LVDP and LVEDP in the hearts isolated at 24 h after treatment but not in those isolated at 2 h. LVDP was 68.9 +/- 4.8 mmHg in NE 24 h group at the end of reperfusion in comparison to 43.6 +/- 2.9 mmHg in saline control group (P < 0.01). Pretreatment with prazosin abolished NE-induced cardioprotection while propranolol pretreatment had no effect. Northern analysis demonstrated rapid and transient increases in c-fos and HSP70 mRNAs in the myocardium after NE treatment. Accumulation of c-fos protein was observed at 3 h and increased amount of HSP72 protein was demonstrated at 24 h in the myocardium. Pretreatment of rats with prazosin eliminated NE-induced increase in cardiac HSP70 mRNA.

CONCLUSIONS

The results suggest that in vivo treatment with NE upregulates the expression of c-fos and HSP70 in the myocardium and induces delayed protection against postischemic myocardial dysfunction in the isolated rat heart. Induction of both the expression of cardiac HSP70 and the delayed cardioprotection by NE appears to be mediated by alpha 1 adrenoceptors.

[The angiographic classification and endovascular therapy of the vein of Galen aneurysmal malformation]

We treated 11 cases of the vein of Galen aneurysmal malformation, one of which was diagnosed by MRI only, and 10 underwent CAG diagnostic procedure. Among the 10 CAG diagnosed cases, 5 were classified as the vein of Galen aneurysmal malformation (VGAM) with the AV shunt directing to the vein of Galen. The other 5 were classified as the vein of Galen aneurysmal dilitation (VGAD) secondary to parenchymal AVM or dural AVF. 8 cases underwent endovascular treatment. For VGAM, the shunts in the wall of the vein were embolized. For VGAD, the primary AVM or AVF were embolized. The pathphysiology, angiographic characteristics, classification and the principle of endovascular therapy of the vein of Galen aneurysmal malformation were discussed.

Mutational analysis of Hsp90 alpha dimerization and subcellular localization: dimer disruption does not impede “in vivo' interaction with estrogen receptor

The molecular chaperone Hsp90 has been found ubiquitously as a predominantly cytoplasmic dimer. By interacting with cytoplasmic or nuclear proteins such as pp60v-src or steroid receptors, Hsp90 helps its targets to become competent for full biological activity. Mutational deletion analysis of some properties of chicken Hsp90 alpha was undertaken after transient transfection of the constructs in COS7 cells. First, Hsp90 mutants were analyzed for their ability to behave as cytosolic dimers. We confirmed that the C-terminal Hsp90 region (amino acids 446–728) was sufficient for dimerization, and found that deletion of three small subregions in the 200 C-terminal residues precluded Hsp90 dimer formation. Moreover, we demonstrated that the N-terminal region of the protein (1–442) was not involved in dimerization. Second, the subcellular localization of the wild-type (WT) protein and mutants was analyzed by specific immunodetection and confocal microscopy. Most of the mutants were cytoplasmic like Hsp90WT, a nuclear localization being barely detectable in the WT protein or in mutants with a C-terminal truncation equal to or shorter than 286 residues. Surprisingly a mutant encoding the N-terminal region (1–285) was nuclear localized. In addition, the in vivo interaction between the cytoplasmic Hsp90 and the nuclear ER was documented after coexpression of both proteins in the same cells: some Hsp90 was shifted into the nucleus via its interaction with ER. From an analysis of dimeric or monomeric cytoplasmic Hsp90 mutants, we found that disruption of Hsp90 dimer did not systematically impede its interaction with ER. Finally, Hsp90WT and cytoplasmic mutants were tested for their ability to rescue from lethality a yeast strain deleted of both Hsp90 genes. Interestingly, the delta 661–677 mutant that showed an impaired dimerization but interacted with ER was able to confer viability, while the mutant deleted of the 30 C-terminal residues (NC6) was monomeric, did not confer viability and did not interact with ER. We therefore suggest that Hsp90 properties analyzed here are not necessarily interdependent.

Inhibition of restriction endonuclease activity by DNA binding fluorochromes

Activity of type II restriction endonuclease is affected by many common factors including buffer composition and sequences flanking the recognition site (Brabec et al., Eur.J. Biochem. 216, 183, 1993). The successful development of Optical Mapping (Schwartz et al., Science, 262, 110, 1993; Meng et al., Nature Genet. 9, 432, 1995; Wang and Schwartz, PNAS, 1995 Cai et al., PNAS, 92, 5164, 1995) relied on optimization of light microscope-based imaging of fluorescently labeled DNA molecules during restriction endonuclease digestion. Little was known about the effects of commonly used DNA-fluorochromes on restriction endonuclease activity. Thus, we developed an enzyme activity assay using lambda bacteriophage DNA or adenovirus-2 DNA to evaluate the effects of five DNA binding fluorochromes (4'-6-daimidine-2-phenylindole (DAPI), ethidium bromide (EtdBr), ethidium bromide homodimer (EthD-1), bis-benzimide (H33258) and benzothiazolium-4-quinolinium dimer (TOTO-1)) on the enzymatic activities of eleven type II restriction endonucleases (Asc I, Csp I, Dra I, EcoR I, Hha I, Hind III, Not I, Rsr II, Sfi I, SgrA I and Sma I). We found that the minor groove binding fluorochrome, DAPI, did not measurably inhibit activity of this group, with the exception of Dra I. Similarly, another minor groove binding fluorochrome H33258 inhibited Dra I and Not I (slightly). The three intercalating fluorochromes EtdBr, EthD-1 and TOTO-1, however, variably inhibited the other enzymes. Since Beta-mercaptoethanol (Beta-ME) is used to discourage photodamage of stained DNA molecules, we also assessed its effect on restriction endonuclease activity. Interestingly, Dra I, Hind III, Sfi I and Sma I retained full activities at high concentration of Beta-ME (5%), but Asc I, Csp I, Not I, Rsr II and SgrA I showed varying sensitivities to the Beta-ME. Isoschizomers Csp I and Rsr II behaved differently to both fluorochromes and Beta-ME. The results presented here should provide a basis for further development of new Optical Mapping-based techniques requiring fluorescence labeling of other actively imaged enzymatic reactions.

Alpha-adrenergic preservation of myocardial pH during ischemia is PKC isoform dependent

alpha-adrenergic stimulation of patients with ischemic heart disease should intuitively impose a destructive stress. However, therapeutic alpha1-adrenergic receptor mediated cardioadaptation prior to myocardial ischemia protects ventricular mechanical function, promotes electrophysiologic stability, and preserves myocyte viability. Prior to an anticipated cardiac ischemic insult, alpha1-adrenergic preconditioning attenuates ischemic myocardial acidosis by a protein kinase C-(PKC) dependent mechanism. The alpha1-adrenoceptor can directly stimulate calcium-independent nPKC isoforms via diacylglycerol (DAG) or indirectly stimulate calcium-dependent cPKC isoforms through the release of intracellular calcium via inositol triphosphate, (IP3). We hypothesized that alpha1-adrenergic limitation of ischemic acidosis is mediated by the family of calcium-dependent PKC isoforms. [31P]NMR spectra were obtained in isolated, buffer perfused rat hearts treated with alpha1-adrenergic stimulation [phenylephrine (PE) 50 microM, 2 min]; PKC blockade [chelerythrine chloride, (Chel) 20 microM]; or stearoyl-arachidonoyl glycerol (SAG, a DAG analogue, 100 microM, 2 min) administered 10 min prior to ischemia. Control hearts were perfused under normoxic conditions for 20 min. All hearts were then subjected to global ischemia (20 min, 37.5 degrees C). Developed pressure (DP) and heart rate were recorded continuously. pHi was obtained from chemical shift of inorganic phosphate. Immunohistochemical staining was utilized to delineate the translocation and activation profiles of specific PKC profiles established with each stimulus. Pre-ischemic alpha1-adrenergic stimulation did attenuate the myocellular hydrogen ion accumulation during sustained normothermic ischemia (6.90 +/- 0.13 vs control 6.54 +/- 0.10; P < 0.05). General PKC inhibition abrogated this effect (end-ischemic pH 6.17 +/- 0.10; P < 0.05 vs control and PE). Ischemic acidosis was not attenuated following selective nPKC stimulation (SAG, 6.48 +/- 0.08; NS vs control). Myocellular immunohistochemical staining revealed translocation of the calcium-independent PKC-epsilon isoform in the calcium-dependent PKC (SAG) group, but not in response to alpha1-adrenergic stimulation. The results suggest that (1) alpha1-adrenoceptor stimulation limits ischemic acidosis, (2) alpha1-adrenergic stimulated attenuation of ischemic acidosis is PKC dependent, (3) direct nPKC stimulation with SAG does not limit ischemic acidosis, and (4) SAG stimulates nPKC-epsilon isoform activation where alpha1-adrenergic stimulation does not. We conclude that alpha1-adrenergic stimulation limits ischemic acidosis by a cPKC-dependent mechanism and that the mobilization of the IP3 arm by receptor stimuli suppresses PKC-epsilon thus permitting the limitation of ischemic acidosis.

A single endotoxin challenge induces delayed myocardial protection against infarcation

Sublethal endotoxemia attenuates cardiac functional injury from global ischemia but it is unknown whether endotoxemia can protect myocardium against infarction. Furthermore, increases in myocardial catalase and heat shock protein (HSP) following endotoxemia have been associated with cardiac ischemic protection. We therefore hypothesized that a 72-hr pretreatment with endotoxin (ETX) would reduce myocardial tissue necrosis in association with augmented catalase activity and stress protein expression. Rabbits were treated with normal saline or lipopolysaccharide (Salmonella typhimurium) at 10, 5, and 1 microgram/kg doses. Three days after saline or ETX injection they were subjected to 45 min of coronary artery occlusion followed by 3 hr of reperfusion. Area of necrosis (tetrazolium staining) was normalized to anatomic risk zone size (Evans blue staining). Catalase activity was measured by a standard assay and HSP 72 was assessed by immunohistochemistry. During regional ischemia and reperfusion there were no differences in heart rate or mean arterial blood pressure between groups. ETX treated rabbits had the same risk zone size as controls. Infarct size was reduced in the ETX treated rabbits at the 10 and 5 microgram/kg doses compared with control rabbits (17.5 +/- 1.5% and 22.2 +/- 3.1% vs 45.3 +/- 2.5%; P < 0.05) but no protective effect was observed at the 1.0 micrograms/kg dose (38.0 +/- 4.6%; P > 0.05 vs control). Catalase activity was not different between control and ETX (5 microgram/kg) treated groups (997.8 +/- 59.1 U/g vs 1099.6 +/- 69.3 U/g myocardium; P > 0.05) but endotoxin induced expression of myocardial HSP 72. We conclude that a single challenge with endotoxin can induce delayed myocardial protection against infarction in vivo. This delayed cardioprotective response involves enhanced stress protein expression without changes in myocellular catalase activity.

[Immunohistochemical double labelling studies on liver tissues superinfected with hepatitis C virus and hepatitis B virus]

OBJECTIVE

To explore the relatiship between hepatitis C virus (HCV) and hepatitis B virus (HBV) replication in liver tissue of patients superinfected with HCV and HBV.

METHODS

The expresion and distribution of HCVAg and HBVAg in paraffin-embeded liver tissue from 25 autopsy cases were studied with immunohistochemical double labelling techniques using monoclonal anti-HCV NS3 and anti-HCV NS5 as well as polyclonal anti-HBs and anti-HBc.

RESULTS

HBsAg and HCV NS3 or NS5 antigen were detected at the same section in 11 and 12 cases, and HBcAg and HCV NS3 or NS5 antigen in each 10 cases, respectively. Nearly all of the specimens with single labelling stained positive tissue for HC-VAg or HBVAg were also those positive with double labelling studies for HCVAg and HBVAg. The distribution of HCV and HBV infected hepatocytes was characterized as diffuse and single or cluster scattered in liver lobular. There were no differences in expression related to replication such as membranous, cytoplasmic type of HBsAg or cytoplasmic type of HBcAg and the cases positive for HCV NS3Ag or HCV NS5Ag between the group of HCV superinfected with HBV and the group infected with single HCV or HBV (chi 2 = 0.154 and 0.198, P > 0.05).

CONCLUSION

The results suggested that there was no interference or suppression each other in liver tissues superinfected with HCV and HBV.