Endothelin-1 in the rat bile duct ligation model of hepatopulmonary syndrome: correlation with pulmonary dysfunction

BACKGROUND/AIMS

Models of hepatopulmonary syndrome require both hepatic injury and portal hypertension to develop pulmonary microvascular and gas exchange abnormalities. Recently, increased endothelin-1 levels associated with vasodilatation, have been observed in cirrhosis. We investigated endothelin-1 production in common bile duct ligated animals with hepatopulmonary syndrome in comparison to partial portal vein ligated animals that do not develop hepatopulmonary syndrome.

METHODS

Organ and plasma endothelin-1 were measured in sham, bile duct ligated and portal vein ligated rats, and Northern analysis and immunohistochemistry were performed in liver. Plasma endothelin-1 levels were correlated with pulmonary endothelial nitric oxide synthase levels and alveolar-arterial oxygen gradients.

RESULTS

Hepatic and plasma endothelin-1 increased only after bile duct ligation, and were accompanied by increased hepatic endothelin-1 mRNA and increased endothelin-1 protein in biliary epithelium. Plasma endothelin-1 levels correlated directly with both pulmonary endothelial nitric oxide synthase levels and alveolar-arterial gradients.

CONCLUSIONS

Enhanced hepatic production and increased plasma levels of endothelin-1 occur after bile duct ligation, but not after portal vein ligation, and correlate with associated molecular and gas exchange alterations in the lung. Endothelin-1 may contribute to the pathogenesis of hepatopulmonary syndrome.

Garlic prevents hypoxic pulmonary hypertension in rats

Hypoxic pulmonary vasoconstriction underlies the development of high-altitude pulmonary edema. Anecdotal observations suggest a beneficial effect of garlic in preventing high-altitude symptoms. To determine whether garlic influences pulmonary vasoconstriction, we assessed the effect of garlic on pulmonary pressures in rats subjected to alveolar hypoxia and on vasoconstriction in isolated pulmonary arterial rings. Garlic gavage (100 mg/kg body wt) for 5 days resulted in complete inhibition of acute hypoxic pulmonary vasoconstriction compared with the control group. No difference in mean arterial pressure or heart rate response to hypoxia was seen between the groups. Garlic solution resulted in a significant dose-dependent vasorelaxation in both endothelium-intact and mechanically endothelium-disrupted pulmonary arterial rings. The administration of NG-nitro-L-arginine methyl ester (a nitric oxide synthase inhibitor) inhibited the vasodilatory effect of garlic by 80%. These studies document that garlic blocks hypoxic pulmonary hypertension in vivo and demonstrate a combination of endothelium-dependent and -independent mechanisms for the effect in pulmonary arterial rings.

Time-resolved optical backscattering model in highly scattering media

A time-resolved backscattering model, which combines a single large-angle scattering with multiple small-angle scatterings, is used to produce a scattered-light profile about a medium. Inhomogeneity of the medium is included in the model. Some multidimensional integrals can be evaluated analytically.

Cholecystokinin B receptors in the periaqueductal gray potentiate defensive rage behavior elicited from the medial hypothalamus of the cat

Defensive rage behavior is mediated over a descending pathway from the medial hypothalamus to the dorsolateral midbrain periaqueductal gray (PAG) where further integration of this response takes place. The present study sought to determine the roles of CCK-A and CCK-B receptor activation in the PAG in modulating defensive rage behavior. The 'hissing' component of the defensive rage response was used throughout the experiment as the measure of defensive rage behavior. The basic design of the experiment involved placement of monopolar electrodes into the medial hypothalamus from which defensive rage could be elicited and cannula electrodes into the dorsal PAG for purposes of identifying defensive rage sites in this region and for microinjections of CCK compounds into these sites at a later time. Microinjections of the selective CCK-B receptor antagonist, LY288513 (1.05, 4.2, 17.0 nmol/0.25 microliter), into the PAG suppressed the hissing response in a dose- and time-dependent manner. Microinjections of the CCK-B agonist, pentagastrin, (0.5 and 1.0 nmol/0.25 microliter) facilitated the occurrence of defensive rage behavior. Moreover, administration of LY288513 (17 nmol/0.25 microliter) 55 min prior to pentagastrin (1.0 nmol/0.25 microliter) delivery blocked the facilitatory effects of pentagastrin. Administration of the CCK-A antagonist, PD140548 (34 nmol/0.25 microliter), into the PAG failed to alter response latencies for defensive rage behavior. In contrast, microinjections of the CCK-B antagonist, LY288513 (4.2, 17.0 nmol/0.25 microliter), facilitated the occurrence of predatory attack behavior elicited from the lateral hypothalamus. This finding demonstrates the specificity of the effects of CCK-B receptor blockade upon hissing. A combination of immunocytochemical and retrograde tracing procedures using microinjections of Fluoro-Gold (8%, 6 microliters) into the PAG were employed to identify the possible loci of CCK neurons that project to the PAG. The data revealed that neurons labeled for both CCK and Fluoro-Gold were located in the dorsolateral aspect of the midbrain tegmentum, identifying this region as a source of CCK inputs to the PAG. Overall, the findings demonstrate that CCK-B receptors in the PAG potentiate defensive rage behavior and likely suppress predatory attack.

Graphic analysis of the effective reflectivity of antireflection-coated films on diode facets

The wavelength dependence of the reflectivity of AR-coated facets and carrier density in relation to peak wavelength of the gain profile have been taken into consideration to study a one-facet AR-coated semiconductor diode laser. A graphic analysis method is developed to study cases in which analytical expressions of the reflectivity curves cannot be extracted. Results show that the upper bound of the carrier density that can be established inside the diode is generally (sometimes to a considerable degree) smaller than that determined by the claimed minimum reflectivity if the spectral width of the reflectivity curve cannot be regarded as infinite. This implies that the effective reflectivity of the AR-coated facet is generally larger than the claimed minimum reflectivity. To increase the effectiveness of AR film, it is essential to maintain tight control of the wavelength at which the reflectivity curve is minimum.

Amplification of photon echo signals by use of a fiber amplifier

The efficiency of photon-echo processes typically lies in the 0.1-1% range. For many photon-echo-based applications suggested in optical storage and all-optical communication the photon-echo output pulses would need to be used as input data to a new photon-echo process. In such cases amplification of the photon-echo output signals would be necessary for an acceptable signal-to-noise ratio to be obtained. We show that a Pr-doped ZBLAN fiber is able to produce significant amplification of photon-echo signals generated in Pr-doped Y(2)SiO(5) at 606 nm.

[Morphological observations of tumors in the cardiac conduction system]

OBJECTIVE

To investigate the incidence of tumors in the cardiac conduction system (CCS) and to study their relation to sudden deaths.

METHODS

The CCS from 149 cases of sudden death without extracardiac cause of deaths and those from 737 cases of non-cardiac death were sampled using technique designed by the authors. Routine histological examinations were carried out.

RESULTS

Tumors in the CCS were found in 12 cases (1.35%). Another case with tumor in the CCS was found in a specimen received for consultation. Of these 13 tumors, 10 were primary benign tumors affecting the CCS, 3 were metastatic tumors. The benign tumors included fibroma, hemangioma, lipomatous hypertrophy of the atrial septum, mesothelioma and rhabdomyoma. 8 of the 10 cases were located in the SAN or AVN. All the metastatic tumors were in the SAN. Of the 13 cases, 3 died suddenly.

CONCLUSION

Tumors in the CCS are the smallest tumors which can cause sudden death.

Isolation and functional analysis of a cDNA for human Jagged2, a gene encoding a ligand for the Notch1 receptor

Signaling through Notch receptors has been implicated in the control of cellular differentiation in animals ranging from nematodes to humans. Starting from a human expressed sequence tag-containing sequence resembling that of Serrate, the gene for a ligand of Drosophila melanogaster Notch, we assembled a full-length cDNA, now called human Jagged2, from overlapping cDNA clones. The full-length cDNA encodes a polypeptide having extensive sequence homology to Serrate (40.6% identity and 58.7% similarity) and even greater homology to several putative mammalian Notch ligands that have subsequently been described. When in situ hybridization was performed, expression of the murine Jagged2 homolog was found to be highest in fetal thymus, epidermis, foregut, dorsal root ganglia, and inner ear. In Northern blot analysis of RNA from tissues of 2-week-old mice, the 5.0-kb Jagged2 transcript was most abundant in heart, lung, thymus, skeletal muscle, brain, and testis. Immunohistochemistry revealed coexpression of Jagged2 and Notch1 within thymus and other fetal murine tissues, consistent with interaction of the two proteins in vivo. Coculture of fibroblasts expressing human Jagged2 with murine C2C12 myoblasts inhibited myogenic differentiation, accompanied by increased Notch1 and the appearance of a novel 115-kDa Notch1 fragment. Exposure of C2C12 cells to Jagged2 led to increased amounts of Notch mRNA as well as mRNAs for a second Notch receptor, Notch3, and a second Notch ligand, Jagged1. Constitutively active forms of Notchl in C2C12 cells also induced increased levels of the same set of mRNAs, suggesting positive feedback control of these genes initiated by binding of Jagged2 to Notch1. This feedback control may function in vivo to coordinate differentiation across certain groups of progenitor cells adopting identical cell fates.

[Colored Doppler ultrasound-guided fine-needle aspiration biopsy of portal vein thrombosis: value in diagnosis and assessment of therapeutic efficacy for portal vein thrombosis]

OBJECTIVE

To investigate the value of colored Doppler ultrasound-guided fine-needle aspiration(FNA) biopsy of portal vien thrombosis(PVT) in diagnosis and assessment of therapeutic efficacy for PVT.

METHODS

Cytologic findings from 25 portal vien thrombosis patients who underwent FNA were reviewed before and after hepatic arterial chemo-embolization(HAE) and portal vien chemotherapy.

RESULTS

1. Biopsy specimens sufficient for histologic analysis were obtained in all cases (100%). No complications resulted from this procedure. 2. The blood flow within the portal vien with thrombosis could be detected by colored Doppler systems in 25 cases before the patients accepted the treatment. The proliferation and a trabecular cellular arrangement presented in all the cell blocks. Of the 25 cases, 4 (16.0%) demonstrated necrosis of the tumor thrombi and the disappearance of blood flow within portal vein thrombi three weeks after the treatment. Among the 4, 2 were followed-up clinically and underwent second stage resection. 21 (84.0%) cases had no significant change in portal vein thrombosis pathologically and ultrasonically after the treatment.

CONCLUSION

Colored Doppler ultrasound-guided FNA biopsy of portal vein thrombi is a safe, accurate, sampling-reliable biopsy technique.

The role of endothelial nitric oxide synthase in the pathogenesis of a rat model of hepatopulmonary syndrome

BACKGROUND & AIMS

The hepatopulmonary syndrome occurs when intrapulmonary vasodilatation causes impaired arterial gas exchange in liver disease. The pathogenesis is poorly understood, although nitric oxide may be involved. Common bile duct ligation in the rat is a model of the hepatopulmonary syndrome, but no studies have evaluated NO in pulmonary vasodilatation in this model. The aim of this study was to determine whether NO contributes to intrapulmonary vasodilatation after bile duct ligation.

METHODS

Endothelial and inducible NO synthase (NOS) levels and localization and NO activity in pulmonary artery rings were assessed after bile duct ligation.

RESULTS

Pulmonary endothelial NOS levels increased and alveolar vascular staining was enhanced after bile duct ligation. No change in pulmonary inducible NOS levels or localization was detected. Increased endothelial NOS levels correlated with alterations in gas exchange and were accompanied by enhanced NO activity and a blunted response to phenylephrine, reversible by NOS inhibition, in pulmonary artery rings. Portal-vein-ligated animals, which do not develop intrapulmonary vasodilatation, had no changes in pulmonary NOS production or in NO activity in pulmonary artery rings.

CONCLUSIONS

NO, derived from pulmonary vascular endothelial NOS, contributes to intrapulmonary vasodilation in animal hepatopulmonary syndrome.

[Identification of deer's foetus and its mixed drugs and flase drugs]

In this paper, the traditional Chinese Materia Medicas--the foetuses of sika deer, red deer and the one of sheep and OX are compared and identified on characters and dissecting characteristices. The comparion and identification table about charaeters and commodity shape drawings is attached.

Common bile duct ligation in the rat: a model of intrapulmonary vasodilatation and hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) causes impaired oxygenation due to intrapulmonary vasodilatation in patients with cirrhosis. Chronic common bile duct ligation (CBDL) in the rat results in gas-exchange abnormalities similar to HPS, but intrapulmonary vasodilatation has not been evaluated. We assess intrapulmonary vasodilatation, measured in vivo, after CBDL. Sham, 2- and 5-wk CBDL, and 3-wk partial portal vein ligated (PVL) rats had hepatic and lung injury, portal pressure, and arterial blood gases assessed. The pulmonary microcirculation was evaluated by injecting microspheres (size range 5.5-10 microm) intravenously and measuring the size and number of microspheres bypassing the lungs in arterial blood. CBDL animals developed progressive hepatic injury and portal hypertension accompanied by gas-exchange abnormalities and intrapulmonary vasodilatation. PVL animals, with a similar degree of portal hypertension, did not develop intrapulmonary vasodilatation or abnormal gas exchange. No lung injury was observed. CBDL, but not PVL, causes progressive intrapulmonary vasodilatation, which accompanies worsening arterial gas exchange. These findings validate CBDL as a model to study HPS.

[Character and UV spectral identification of deer's heart]

In this paper, the fresh and dried hearts of Cervus nippon and C. elaphus are identified on character, fluorescence and UV spectra. The alcohol extract of the blood of the deer's hearts has mininum absorption at UV 310 nm.

Mapping sequence specific DNA-protein interactions: a versatile, quantitative method and its application to transcription factor XF1

We have developed a method for the quantitative, exhaustive sequence specificity determination of DNA-binding proteins. The QuESSD method overcomes the limitations inherent in other published in vitro selection methods, not only defining the consensus sequence, but also quantifying the effect on DNA-protein affinity of replacing each base in the recognition domain with every other base. The features distinguishing this method from other in vitro selection approaches are: (1) instead of synthesizing one target oligonucleotide population containing a long randomized domain, we synthesize several oligonucleotide populations, each randomized at two positions. (2) Instead of carrying out several cycles of selection and amplification, we carry out a single cycle. (3) We have developed data collection and analysis procedures that eliminate artifacts and allow generation of quantitative results. The QuESSD method yields accurate measures of: (a) the selectivity of the protein for each base at each position within the recognition domain (normalized relative selectivity), (b) the contributions of individual sites within the recognition domain to the binding affinity (selectivity variance), (c) the relative binding affinity of any given sequence (global selectivity). We confirmed results by (1) tabulating directly the frequency of appearance of individual species in the pool of protein-bound oligonucleotides by cloning and sequencing individual oligonucleotides, and (2) competition EMSA analysis of oligonucleotides designed on the basis of QuESSD data. We have used this method to map the sequence specificity of the nuclear protein XF1 and to distinguish the sequence specificities of XF1 and the AH receptor complex, both of which bind to XRE1, a xenobiotic responsive element (XRE) located upstream of the CYP1A1 gene. Using data obtained by the QuESSD method, we designed oligonucleotides specific for XF1 or for the AH receptor, and prepared CAT reporter gene constructs carrying these oligonucleotides, or wild-type XRE1, upstream of a minimal promoter. Transfection studies using these constructs indicated that XF1 can function as a weak activator of basal transcription, and can, under some circumstances, compete with the AH receptor for binding to XRE1.

[Color Doppler in evaluating the effects of octreotide on portal hemodynamics]

OBJECTIVE

To study the effects of octreotide on portal pressure and the relationship between the portal pressure and portal hemodynamics measured by color Doppler.

METHODS

A high portal resistance model by injecting bletilla hyacinthina was established in 6 dogs. The portal pressure and portal hemodynamics studied by color Doppler were measured respectively by two investigators before and after injecting octreotide into the peripheral vein.

RESULTS

Portal hypertension was caused by injecting bletilla hyacinthina into the portal vein. The portal pressure was reduced and portal venous velocity increased after injecting octreotide into the peripheral vein. There was a significant negative correlation between the portal pressure and portal venous velocity.

CONCLUSION

Color Doppler is helpful in evaluating the effects of octreotide on the portal pressure.

The diabetic state increases the activity but not the number of peritoneal macrophages in the GK rat promoting the tube formation of cultured endothelial cells in rat aorta

The influence of the diabetic state on the number and activity of intraperitoneal macrophages was investigated in the GK rat. This rat is a model of non-insulin-dependent diabetes mellitus and was established from the normal Wistar rat. The cell number of a macrophages preparation in diabetic GK rats (10-15 weeks of age) did not differ from that in normal Wistar rats (9-10 weeks of age). The co-cultured macrophages in diabetic GK rats (9-12 weeks of age) significantly increased the tube formation of aortic endothelial cells (EC) compared with that in age-matched Wistar rats. The conditioned medium obtained from a culture of macrophages from GK rats also increased tube formation more than that from a culture of macrophages from Wistar rats. The effect of macrophages in the GK rat was not influenced by interferon-gamma (160 and 460 pM), but macrophages in normal rats were activated by these concentrations of interferon-gamma. In conclusion, the diabetic state increased the activity but not the number of macrophages in the GK rat, to stimulate tube formation of EC. The tube-forming effect of macrophages in the diabetic state may depend on released factors which differ from that of normal macrophages.

Computerized microimage analysis of age-related changes of the human sinoatrial node

This paper reports the age-related changes in the histological features of the sinoatrial node (SAN). The hearts of 106 persons dying at different ages (2 days-83 years), without clinical or pathological evidence of cardiac disease, were taken and divided into seven age-groups. Serial sections with a thickness of 2 microns, parallel to the long axis of the SAN, were prepared. Sections with the maximal area of the SAN were stained with hematoxylin/eosin (H & E) and Betty's method. The largest area of SAN were calculated by a computerized microimage analysis system. The age-related changes of the human SAN were discussed.

[Surgical treatment of 165 cases of stage III small cell lung carcinoma]

The author analysed the effect of surgical therapy in 165 cases with stage III SCLC from 1979 to the end of 1991, and compared with 87 cases of combined therapy and 78 cases in simple operative therapy. The author also makes an observation of cases with pre-operative and (or) post-operative chemo- and radiation therapy. Their over-all 5 year survival rate was 16.6%. Stage among 5 year survival cases in TNM stage. IIIa was 20.4% and no for Stage IIIb. The 5 year survival of combined therapy was 22.8% and that of simple operative group was 7.9%. The result shows that in the Stage III SCLC combined therapy is superior to that of simple operative group. It seems that postoperative radiation and chemotherapy is better than pre-operative in combined therapy group. The author's opinion is that surgical indication of SCLC is limited to stage IIIa.

[A KABP (knowledge, attitude, belief and behavior) study about AIDS among taxi drivers and hotel attendants in Beijing]

This article reports the KABP study on 448 taxi drivers and 556 hotel attendants in Beijing for the first time in China. A self-administered questionnaire was used to investigate knowledge, attitude, belief and practice (KABP) about AIDS. In terms of knowledge, 23.8% of hotel attendants and 36.8% of taxi drivers did not know that contact with blood could transmit HIV. Thirtyfive percent of hotel attendants and 42.2% of taxi drivers did not believe that intravenous drug users were at high risk. Some drivers (13.6%) and hotel attendants (3.4%) reported having multiple sexual partners. Forty-one point nine percent of taxi drivers and 16.6% of hotel attendants preferred the idea of multiple sexual partners. Among hotel attendants, a negative association was found between knowledge about AIDS and multiple sexual behavior (P < 0.01). Regarding attitude toward condom use, 56.2% of taxi drivers and 47.8% of hotel attendants who have had a sexual experience thought that condom use interfered with sexual pleasure. Seventy-six point eight percent of taxi drivers and 79.8% of hotel attendants believed that they could change their behaviors in order to minimize the chances of getting HIV. This study indicates that HIV education is important in reducing the number of sexual partners and promoting the use of safe sex practices like condom use. Furthermore, as reported by the study population, education can change behavior.