Slowing of intestinal transit by fat depends on naloxone-blockable efferent, opioid pathway

Slowing of transit through the proximal small intestine by fat in the distal gut is termed the ileal brake. Intravenous naloxone, an opioid receptor antagonist, abolished the fat-induced ileal brake, suggesting that an endogenous opioid pathway may be involved in this response. To test the hypothesis that slowing of intestinal transit by fat in the distal half of the gut depends on an opioid pathway located on the efferent limb of this response, we compared intestinal transit in dogs equipped with duodenal and midgut fistulas while naloxone was either compartmentalized with oleate to the distal half of the gut or with buffer to the proximal half of the gut. We found that intestinal transit depended on the perfusion conditions (P<0.00001). Specifically, compared with ileal brake (marker recovery of 35.7+/-7.4%), intestinal transit was accelerated when naloxone was delivered into the proximal half of the gut (76.2+/-5.2%) (P<0.005) but not the distal half of the gut (29.4+/-5.4%). We conclude that slowing of intestinal transit by fat in the distal half of the gut depends on an opioid pathway located on the efferent limb of the ileal brake.

Diterpenoids from Salvia miltiorrhiza

The abietane diterpenoid, neocryptotanshinone II, and the known 6,12-dihydroxyabieta-5,8,11,13-tetraen-7-one were isolated as minor components from the roots of Salvia miltiorrhiza. Their structures were established on the basis of spectral evidence.

Effects of prostacyclin inhibition on splanchnic hyposensitivity to glypressin in a hemorrhage-transfused rat model of portal hypertension

BACKGROUND

Hyposensitivity to vasopressin is a well-documented phenomenon in animals with portal hypertension and patients with cirrhosis and hemorrhage. Similar findings exist with infusion of glypressin (a long-acting vasopressin analogue), and this phenomenon could be ameliorated by inhibition of nitric oxide (NO) synthase. Besides NO, excessive formation of prostacyclin (PGI2) has been shown to play an important role in the development of hyperdynamic circulation and the mediation of hyporeactivity to vasoconstrictors in portal-hypertensive states. This study was designed to investigate whether the blockade of PGI2 activity by indomethacin infusion could enhance the portal-hypotensive effect of glypressin in portal-hypertensive rats with bleeding.

METHODS

Portal hypertension was induced by partial portal vein ligation (PVL). Fourteen days after operation systemic and portal hemodynamics were measured in stable or bleeding PVL rats receiving intravenous glypressin (0.07 mg/kg) or indomethacin (5 mg/kg) followed by glypressin infusion. In rats with a hypotensive hemorrhage 4.5 ml of blood was withdrawn, and 50% of the withdrawn blood was reinfused before the administration of glypressin or indomethacin.

RESULTS

Splanchnic hyposensitivity to glypressin was shown in hemorrhage-transfused PVL rats. Indomethacin infusion did not cause significant systemic and portal-hemodynamic changes in bleeding PVL rats (P > 0.05). The addition of indomethacin significantly enhanced the portal-hypotensive effects of glypressin and potentiated the increases in mean arterial pressure induced by glypressin infusion in bleeding PVL rats.

CONCLUSIONS

The improvement of splanchnic hyposensitivity to glypressin in a hemorrhage-transfused rat model of portal hypertension by the administration of indomethacin suggests that PGI2 has in the development of this hyposensitivity.

Establishment of an animal model of hepatic encephalopathy

BACKGROUND

Hepatic encephalopathy is a neuropsychiatric syndrome associated with acute liver failure, chronic parenchymal liver disease or portal systemic anastomosis. The spectrum of symptoms may vary from subtle mental changes to a disrupted circadian rhythm to hepatic coma. In order to investigate the possible pathogenetic mediators and the use of potential new therapies, the aim of our study was to create a reliable animal model for research on hepatic encephalopathy.

METHODS

Forty male Sprague-Dawley rats were used. Fulminant hepatic failure was induced by intraperitoneal injection of thioacetamide (TAA, 350 mg/kg) for three consecutive days (n = 30). Rats treated with normal saline served as controls (n = 10). The clinical stage of hepatic encephalopathy in TAA-treated rats was graded according to neurobehavioral testing. Spontaneous motor activities of rats were calculated using the Opto-Varimex animal activity meter. We also investigated the relationships between the neurobehavioral score and the motor activity count.

RESULTS

Compared with normal, saline-treated rats, those receiving consecutive injections of TAA had apparently lower neurobehavioral scores (p < 0.001) accompanied by significantly blunted motor activities (p < 0.001). A significant correlation was demonstrated between the neurobehavioral score and total movements in rats with encephalopathy (r = 0.71, p < 0.001). In addition, the neurobehavioral score also correlated well with ambulatory movements (r = 0.73, p < 0.001) and vertical movements (r = 0.45, p < 0.05).

CONCLUSIONS

The rat model is acceptable for the study of hepatic encephalopathy, as established in this study. This experimental model can be used to explore the pathogenesis and management of hepatic encephalopathy.

Treatment of mastalgia with tamoxifen in male patients with liver cirrhosis: a randomized crossover study

OBJECTIVE

Mastalgia is occasionally found in patients with liver cirrhosis, especially in those receiving spironolactone for treatment of ascites. The pathogenesis is still unclear. Estrogen excess in cirrhotic patients and estrogenic effects of the spironolactone are possible leading causes. Treatment directed against the preponderance of estrogenic stimulation in these patients has never been investigated. This study was designed to investigate the efficacy and safety of tamoxifen, an estrogen antagonist, on mastalgia in patients with liver cirrhosis.

METHODS

A total of 16 male cirrhotic patients with mastalgia were randomly assigned to two groups. One group was treated with tamoxifen (20 mg p.o., b.i.d.) for 1 month, followed by placebo for the next month. The other group was treated in the reverse order. All patients received spironolactone for ascites and/or peripheral edema, and the drug was continued during the study period. The size of the breasts and the degree of breast pain and tenderness were recorded in all subjects before and after the treatment periods. Serum levels of estradiol and testosterone were measured using the radioimmunoassay method.

RESULTS

Of the 16 patients, 14 experienced a decrease or disappearance of the breast pain and/or tenderness during the tamoxifen treatment period, whereas only two of the 16 patients felt an improvement during the placebo period (p < 0.05). There were significant improvements in the breast pain and tenderness scores and decreases in the breast sizes during the tamoxifen treatment period (before vs after: 1.4+/-0.3 vs 0.4+/-0.2, p = 0.002; 1.9+/-0.2 vs 0.5+/-0.2, p < 0.001; and 6.8+/-0.6 vs 5.5+/-0.6 cm, p = 0.02, respectively), whereas no obvious change was seen during the placebo period. Serum levels of estradiol and testosterone did not change significantly after the tamoxifen or placebo treatments (p > 0.05). No major side effects were noted during the therapeutic periods.

CONCLUSIONS

Tamoxifen is effective and safe in the management of mastalgia in male cirrhotic patients taking spironolactone.

Sequential changes in plasma cytokine and endotoxin levels in cirrhotic patients with bacterial infection

To delineate the clinical roles of plasma cytokine or endotoxin levels in the natural course of infection in patients with decompensated cirrhosis, 66 cirrhotic patients were studied within a 1.5-year period. Plasma levels of tumour necrosis factor-alpha (TNF-alpha), interleukin-1beta (IL-1beta), IL-6, IL-8 and endotoxin were determined on days 1, 4 and 7 after admission when hospital infection was suspected and 4 months later. A total of 24 patients (36.4%) were proven to be infected during hospitalization (group A), while 42 others were not infected (group B). Fever occurred in a very high proportion (22/24) of group A patients. Baseline levels of TNF-alpha (37.7+/-15.2 compared with 8.7+/-1.2 pg/ml; P<0.01) and IL-6 (180.5+/-20.5 compared with 24.6+/-7.5 pg/ml; P<0.0001) were higher in group A patients, while IL-1beta, IL-8 and endotoxin levels were not significantly different between the two groups. For patients with hospital infection, IL-6 levels determined during the episode were significantly higher than baseline levels. Using IL-6 >80 pg/ml as a baseline cut-off level to diagnose bacterial infection, the sensitivity, specificity and accuracy were 87.5, 100 and 95.5% respectively. The one-year cumulative probability of mortality (61.1% compared with 23.7%; P<0.001) and of bacterial re-infection (72.2% compared with 18.4%; P<0.0001) was higher in group A than in group B. Plasma TNF-alpha and IL-6 levels determined at 4 months were not different between the two groups. In conclusion, fever or elevated plasma IL-6 levels in patients with decompensated cirrhosis calls for early antibiotic treatment to prevent life-threatening bacterial infection. Bacterial infection is likely to recur in those patients with increased IL-6 levels, while severe episodes of infection occur in patients with increased TNF-alpha levels.

Hypodense alveolar macrophages in patients with diabetes mellitus and active pulmonary tuberculosis

SETTING

Alveolar macrophages (AM), a heterogeneous cell population, play a critical role in eliminating mycobacterial infections in collaboration with lymphocytes. Patients with diabetes mellitus (DM) show increased susceptibility to pulmonary tuberculosis (TB) infection. It is still uncertain whether there is a defect in T cell or AM activation in patients with DM against TB infection.

OBJECTIVE

To study the difference in activation status of AM and T cells between patients with TB + DM and TB alone.

METHOD

The heterogeneity of AM from 14 patients with TB + DM, 9 with TB alone, 10 normal subjects and 8 DM alone patients, was studied using Percoll density fractionation. The intracellular H2O2 production of AM before and after stimulation with phorbol myristate acetate (PMA) or F-Met-Leu-Phen (FMLP) was assayed by loading cells with 2',7'-dichlorofluorescin (DCFH) and analyzed by flow cytometry. Lymphocytes subsets (CD3, CD4, CD8) and their activation status (CD25) in bronchoalveolar lavage were also measured.

RESULTS

The proportion of the least dense AM (< 1,030 g/ml) and the magnitude of DCFH oxidation of AM was higher in TB patients than in normal subjects, regardless of DM. Patients with TB + DM had a significantly lower proportion of the least density AM fraction than TB alone patients, regardless of disease extent. Among TB patients, the proportion of the least dense AM was inversely correlated with the bacterial load on sputum and the disease extent on chest radiograph. Stimulation of AM with PMA or FMLP induced an increase in the hypodense AM subpopulations and enhanced intracellular H2O2 generation in patients with TB + DM and to a similar extent in normal subjects, but not in patients with TB alone. There was no significant difference in CD3 numbers, CD4/CD8 ratio, and CD25+ cells between patients with TB alone and TB + DM. The activation status of AM or T lymphocytes from DM alone patients was not significantly different from those from normal subjects.

CONCLUSION

Hypodense subpopulations of AM increase in active TB patients and are related to the disease severity as well as activation status of AM. AM in TB patients complicated with DM was less activated, and may be contributory to the susceptibility to mycobacterial infection.

Systemic administration of d-amphetamine induces long-lasting oxidative stress in the rat striatum

The long-term effect of d-amphetamine (AMPH) on the induction of oxidative stress was examined in vivo in the rat brain. In this study, 2,3-dihydroxybenzoic acid (2,3-DHBA) and malonaldehyde (MDA) were used as the index of the hydroxyl radical and lipid peroxidation, respectively. The levels of 2,3-DHBA, MDA and dopamine (DA) in striatal homogenates were examined 7 days following injection of a single large dose of AMPH (7.5 mg/kg, i.p.) in rats pretreated with desipramine (10 mg/kg, i.p.), an agent that inhibits the metabolism of AMPH. Our results showed that 2,3-DHBA and MDA levels were significantly increased by AMPH, whereas DA and its metabolites, DOPAC and HVA were depleted in the striatum. Pretreatment with the glutamate NMDA receptor subtype antagonist MK-801 (1 mg/kg, i.p.) attenuated the increases of 2,3-DHBA and MDA, and provided partial protection against the long-lasting loss of DA produced by AMPH. Overall, the results demonstrate that AMPH could induce sustained production of free radical and oxidative damage, and lead to DA terminal degeneration in the striatum of the rat.

Pertussis seroepidemiology in Taipei

PURPOSE

We evaluated the seroprevalence of pertussis among apparently healthy Taipei residents.

METHODS

From January 1992 through December 1994, we recruited subjects from a well baby clinic (children < 3 years), kindergartens, primary, and secondary schools and colleges (3-20 years), a health exam clinic (> 20 years), and obstetric clinics (pregnant women). Subjects were stratified into 12 groups according to age and pregnant women were considered separately. The serum antibody titers against filamentous hemagglutinin (FHA) and pertussis toxin (PT) were measured by enzyme-linked immunosorbent assay.

RESULTS

The anti-PT and anti-FHA titers were elevated in the 4 to 6-month and 19 to 20-month age groups, coinciding with regular pertussis vaccinations. The anti-PT titers rose again in the 3 to 4-year age group, reflecting a higher prevalence of natural pertussis infection. The anti-PT titers gradually decreased among older age groups, although a peak occurred in the 11 to 15-year age group. The sequential changes in anti-FHA titers followed those of anti-Pt titers in the younger age groups, but the anti-FHA titers were persistently elevated beyond 15 years of age. The antibody levels were similar in the two sexes, except that anti-PT titers were higher in males of 19 to 20 months and 21 to 30 years of age. Anti-PT titers were equivalent between neonates (0-2 months) and pregnant women, but anti-FHA titers were much lower in neonates.

CONCLUSIONS

The seroprevalence patterns in this study indicate that young children, adolescents, and even adults remain at risk of pertussis, despite the current immunization program. Booster vaccinations after completion of the current four-dose immunization schedule, possibly continuing into adolescence, should be considered to block the transmission of infection.

Splanchnic endotoxin levels in cirrhotic rats induced by carbon tetrachloride

BACKGROUND

Bacterial translocation (passage of intestinal bacteria to mesenteric lymph nodes) observed in cirrhosis may be a source of endotoxin that can stimulate nitric oxide production and participate in the pathogenesis of hyperdynamic circulation. Currently, there are no published data concerning splanchnic endotoxin levels in cirrhotic rats. This study was designed to determine systemic and portal hemodynamics and to detect endotoxins in the portal and systemic circulation.

METHODS

Liver cirrhosis was induced by carbon tetrachloride intragastric gavage. Systemic and splanchnic endotoxin levels in control rats and cirrhotic rats with or without ascites were measured using a chromogenic Limulus assay. In addition, systemic and portal hemodynamic data were obtained using a thermodilution technique and catheterization.

RESULTS

Cirrhotic rats with ascites had the lowest systemic vascular resistance (2.6 +/- 0.1 mmHg.ml-1.min.100 g body weight, BW) compared with control rats (6.3 +/- 0.3 mmHg.ml-1.min.100 g BW; p < 0.05) and cirrhotic rats without ascites (3.7 +/- 0.3 mmHg.ml-1.min.100 g BW; p < 0.05). Cirrhotic rats with ascites displayed the highest splanchnic levels of endotoxin (10.6 +/- 3.1 pg/ml) compared with cirrhotic rats without ascites (2.0 +/- 0.7 pg/ml; p < 0.05) and control rats (2.0 +/- 0.4 pg/ml; p < 0.05). There was no difference in the splanchnic endotoxin levels between control rats and cirrhotic rats without ascites (p > 0.05). Similar results were observed with systemic endotoxin values (cirrhotic rats with ascites, 10.8 +/- 2.8 pg/ml; cirrhotic rats without ascites, 2.7 +/- 0.6 pg/ml; control rats, 2.5 +/- 0.4 pg/ml; p < 0.05). A significant correlation existed between portal and systemic endotoxin values in cirrhotic rats with or without ascites (r = 0.96, p < 0.001 and r = 0.9, p < 0.05, respectively), whereas this correlation did not exist in control rats (r = 0.5, p > 0.05).

CONCLUSIONS

Cirrhotic rats with ascites had the lowest systemic vascular resistance and the highest splanchnic endotoxin levels when compared with cirrhotic rats without ascites and control rats. These results suggest that splanchnic endotoxemia may be involved in the development and/or maintenance of hyperdynamic circulation.

Recurrence of esophageal varices following endoscopic treatment and its impact on rebleeding: comparison of sclerotherapy and ligation

BACKGROUND/AIMS

Endoscopic variceal ligation is superior to sclerotherapy because of its lower rebleeding and complication rates. However, ligation is not without drawbacks due to a higher tendency to variceal recurrence. We conducted a randomized cohort study to delineate the long-term history of variceal recurrence following ligation and sclerotherapy, and to clarify the impact of recurrence on rebleeding and on the consumption of endoscopic treatment resources.

METHODS

Two hundred cirrhotic patients with esophageal variceal bleeding were randomized to undergo maintenance endoscopic variceal sclerotherapy or ligation.

RESULTS

One hundred and forty-one patients achieved variceal eradication and were regularly followed up for 2.2 to 6.7 (mean: 5.1 +/- 1.2) years. The demographic data, hepatic reserve, bleeding severity, and endoscopic features of both sclerotherapy (n=70) and ligation (n=71) showed no difference. Forty (57.1%) patients who underwent sclerotherapy experienced 58 recurrences of esophageal varices, in contrast to the 46 (64.8%) patients who underwent ligation and experienced 81 episodes of recurrence. Kaplan-Meier analysis showed that within 2 years variceal recurrence was more frequent for ligation than sclerotherapy, and the difference decreased thereafter. Multiple recurrence appeared more common with ligation (1/2/3/4/5 episodes of recurrence: 46/23/8/3/1 vs. 40/14/3/1/0, p=0.08). On multifactorial analysis, the endoscopic treatment method and red wale markings were the two factors determining variceal recurrence. Rebleeding from recurrent esophageal varices was unusual and showed no difference between the two groups (7/58 vs. 6/81, p>0.05). Rebleeding from gastric varices was more common after eradication by sclerotherapy (7/19 vs. 1/16, p=0.085) than by ligation. The number of sessions required for eradication of recurrent varices was no different between the two groups.

CONCLUSIONS

Early recurrence and multiple recurrence of esophageal varices are more likely in patients undergoing endoscopic ligation, compared to sclerotherapy; however, the recurrence did not lead to a higher risk of rebleeding or require more endoscopic treatment.

An endoscopic injection with N-butyl-2-cyanoacrylate used for colonic variceal bleeding: a case report and review of the literature

We report a 64-yr-old patient with liver cirrhosis and bleeding esophageal varices that were obliterated by repeated endoscopic sclerotherapy. Eleven years later, he developed a massive, life-threatening rectosigmoid variceal hemorrhage. An endoscopic injection with N-butyl-2-cyanoacrylate (Histoacryl), performed over the rectosigmoid varices, achieved temporary hemostasis. The etiology, prevalence, relationship with portal hypertension, diagnosis, and treatment of colorectal varices are discussed.

The effect of incentive spirometry on chest expansion and breathing work in patients with chronic obstructive airway diseases: comparison of two methods

BACKGROUND

Chronic obstructive airway diseases (COAD), characterized by mucus hypersecretion, lead to exercise intolerance. Incentive spirometry has been used to prevent postoperative pulmonary atelectasis.

METHODS

To compare the efficacy of two incentive spirometers, Coach (volume-oriented) and Triflo (flow-oriented), in the work of breathing in COAD patients, 22 patients were randomized in this study: 12 patients (Triflo-II group) initially used Triflo-II for 10 minutes and then Coach for the same period. In contrast, the Coach group, including 10 patients, started with Coach followed by Triflo-II. After receiving incentive spirometry, lung expansion and work of breathing were assessed.

RESULTS

Patients in the Coach group significantly increased chest wall expansion (p = 0.041), as compared with patients using Triflo-II. Similarly, there was also a significantly increased abdominal wall expansion in the Coach group (p = 0.0056), compared with that in the Triflo-II group. The need of accessory muscle assistance for breathing in the Coach group was significantly less than in the Triflo-II group (p = 0.047). It was easier for patients in the Coach group to start a breath (p = 0.0058) than for those in the Triflo-II group. For the entire group, 17 patients (77.3%) preferred Coach to assist their breathing, and only 4 patients (18.2%) favored Triflo-II.

CONCLUSION

COAD patients achieved a larger expansion of the chest and abdomen with a Coach device. Our data provide a good rationale for an outcome study on the use of incentive spirometer in COAD patients.

Symptomatic esophageal stricture after endoscopic variceal ligation--success of endoscopic balloon dilation

Endoscopic variceal ligation is a preferred endoscopic method to treat esophageal variceal bleeding. Esophageal stricture complicated by endoscopic ligation is very unusual. We report a case of symptomatic esophageal stricture after variceal ligation. Endoscopic balloon dilatation was used to treat the stricture successfully. The possible mechanism of stricture formation is discussed.

An endoscopic injection with N-butyl-2-cyanoacrylate used for colonic variceal bleeding: a case report and review of the literature

We report a 64-yr-old patient with liver cirrhosis and bleeding esophageal varices that were obliterated by repeated endoscopic sclerotherapy. Eleven years later, he developed a massive, life-threatening rectosigmoid variceal hemorrhage. An endoscopic injection with N-butyl-2-cyanoacrylate (Histoacryl), performed over the rectosigmoid varices, achieved temporary hemostasis. The etiology, prevalence, relationship with portal hypertension, diagnosis, and treatment of colorectal varices are discussed.

Intra-striatal infusion of D-amphetamine induces hydroxyl radical formation: inhibition by MK-801 pretreatment

Recent evidence suggests that free radicals can be produced in the brain following systemic administration of repeated or high doses of D-amphetamine (AMPH). However, it has been proposed that the toxic effects of AMPH are mostly secondary to AMPH-induced hyperthermia, and agents that protect against AMPH neurotoxicity do so by blocking AMPH-induced hyperthermia or causing hypothermia. In this study, we examined the effects of AMPH on the formation of hydroxyl radicals (*OH) following its infusion into the rat striatum via a microdialysis probe. We found that intra-striatal perfusion of AMPH (10 microM) caused an increased formation of hydroxyl radicals but did not raise the core temperatures of the rats. Pretreatment with the NMDA antagonist MK-801 (0.5 mg/kg) attenuated hydroxyl radical production elicited by AMPH infusion, although core body temperatures in AMPH-treated rats were not significantly altered. Additionally, infusion of AMPH in the striatum increased extracellular dopamine concentration and this effect was potentiated by MK-801 pretreatment. Thus, these results demonstrate that direct infusion of AMPH in the striatum induces hydroxyl radical production without causing hyperthermia, and also imply that activation of glutamate NMDA receptors mediates, at least in part, AMPH-induced hydroxyl radical formation in the rat striatum.

Nitric oxide modulates interleukin-1beta and tumor necrosis factor-alpha synthesis by alveolar macrophages in pulmonary tuberculosis

Interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha released from alveolar macrophages (AM) in pulmonary tuberculosis (TB) are important in host defense against mycobacterial infection. Nitric oxide (NO) production is enhanced in AM of TB patients. We examined whether NO was implicated in (IL)-1beta and TNF-alpha synthesis by AM of TB patients. Purified AM were retrieved by bronchoalveolar lavage from 11 TB patients and 10 normal subjects, and were cultured with or without the NO inhibitor N(G)-monomethyl-L-arginine (L-NMMA). The release of IL-1beta and TNF-alpha, and expression of their messenger RNAs (mRNAs), were determined by enzyme-linked immunosorbent assay and Northern blot analysis. The release of IL-1beta and TNF-alpha was greater from AM of TB patients than from AM of normal subjects. L-NMMA inhibited nitrite, IL-1beta, and TNF-alpha production in TB patients. The mRNA expression for IL-1beta and TNF-alpha was upregulated in TB patients and was depressed by L-NMMA. Immunocytochemistry done with a monoclonal antibody against the p65 subunit of nuclear factor (NF)-kappaB showed that NF-kappaB was highly expressed and translocated to the nuclei of AM from TB patients, and was inhibited by L-NMMA. Inhibition of NF-kappaB by pyrrolidine dithiocarbamate attenuated IL-1beta and TNF-alpha synthesis. In conclusion, enhanced NO generation by AM of TB patients plays an autoregulatory role in amplifying the synthesis of proinflammatory cytokines, probably through NF-kappaB activation.

Endotoxemia augments neurogenic plasma exudation in guinea pig lungs

BACKGROUND

Lipopolysaccharide (LPS) is closely associated with the development of infection-induced deleterious pulmonary reactions. In this study, we investigated the enhancement effects of LPS on tachykinin-mediated plasma exudation in the lungs of guinea pigs. The role of oxidants was also explored.

METHODS

Intravenous LPS (100 mu kg-1) or its vehicle was administered 0 to 3 hours prior to bilateral electrical or sham stimulation of the cervical vagus nerves in animals anesthetized with urethane and artificially ventilated. Plasma exudation into the lungs was assessed by measurement of extravasated 125I-albumin which had been intravenously administered before stimulation.

RESULTS

The plasma exudation in the lungs increased after bilateral cervical vagal stimulation. LPS alone did not induce significant plasma exudation. The vagally-mediated plasma exudation was enhanced by LPS with the peak effect 1 hour after LPS administration. LPS also enhanced exogenous substance P (10(-8) mol kg-1, i.v.)-induced plasma exudation. The vagally-induced plasma exudation was abolished by a specific neurokinin-1 (NK-1) receptor antagonist, L-732,138. The LPS-induced enhancement response was also attenuated by L-732,138. The vagally-induced plasma exudation was not affected by superoxide dismutase (SOD, 5000 U kg-1, i.p.) pretreatment. However, SOD significantly inhibited the LPS-enhanced neurogenic plasma leakage. The LPS-induced enhancement was not completely abolished by either L-732,138 or SOD pretreatment alone, but by a combination of both.

CONCLUSION

LPS augments neurogenic plasma exudation partly through NK-1 receptors to increase vascular permeability and partly via the generation of oxidative metabolites. Tachykinins released from nerve endings may contribute to endotoxin-related pulmonary inflammatory responses.

Clinical analysis of a dysentery outbreak in Taichung

In September 1993, we collected 207 patients due to dysentery, who visited the Department of Pediatrics at China Medical College Hospital. In our report, 67.6% of these patients were amebic dysentery, 19.3% were combined infection with amebic and Shigella sonnei dysentery, and 13.1% were Shigella sonnei dysentery. Therefore, amebic dysentery was the predominant cause during this outbreak. The clinical features of this outbreak were, in descending order, watery stool, fever, abdominal pain, mucinous stool and bloody stool. No concurrent liver abscess was discerned. Because there had not been such a clustering of dysentery in Taichung for so many years, we thought that travel to endemic areas might have been the underlying predisposing cause. Most of the school water supplying system was ground water, which might have been contaminated by a few patients returning from endemic areas. We thought that fecal-oral route by contaminated water might have been the primary transmission route.

Systemic administration of D-amphetamine induced a delayed production of nitric oxide in the striatum of rats

Nitric oxide (NO) is a free-radical gas with a role in various signal transduction processes. In the CNS, NO acts as an important central nervous messenger, but in excess it may be neurotoxic. Chronic or high dose administration of D-amphetamine (AMPH) has been shown to induce striatal neurotoxicity in rodents and primates. In this study, we studied whether AMPH given systemically elicits NO formation in the striatum of rats and determined the relationship between NO formation and striatal DAergic terminal damage. Our results demonstrated that a single large dose administration of AMPH with desipramine elicited a delayed production of NO and concomitant long-term DA loss in the striatum. These phenomena were blocked by treatment with either the nitric oxide synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME) or the glutamate N-methyl-D-aspartate antagonist MK-801. It appears that AMPH-induced NO formation is critical for development of long-lasting DAergic terminal toxicity in the striatum of rats.

Immunogenicity of oral poliovirus vaccine in Taiwan

Previous studies have shown that the immune response to trivalent oral poliovirus vaccine (OPV) varies widely from country to country. However, there has been no report on the immunogenicity of this vaccine in Taiwanese children. In this study, 98 children were followed up for 17 months to study the antibody responses following four doses of trivalent OPV. The results showed that, after two doses of vaccine, all children were protected against poliovirus type 1 and 2. All except two children also developed protective antibodies against poliovirus type 3. After three doses, the antibody levels in all subjects were above protective concentrations. The fourth dose, given at 18 months of age, further boosted the antibody titers. These findings show that the OPV currently used in Taiwan is highly immunogenic in Taiwanese children.

The rebleeding course and long-term outcome of esophageal variceal hemorrhage after ligation: comparison with sclerotherapy

BACKGROUND

Endoscopic variceal ligation is widely accepted as the optimum endoscopic treatment for esophageal variceal hemorrhage. However, the rebleeding course and long-term outcome of patients with esophageal variceal hemorrhage after ligation have been poorly defined. Therefore, we conducted a long-term follow-up study to delineate the outcome of ligation and compare it with that after sclerotherapy.

METHODS

One hundred and eighty-five liver cirrhotic patients with endoscopically proven esophageal variceal hemorrhage were randomized to undergo endoscopic variceal sclerotherapy or ligation. These patients received regular follow-up and detailed clinical assessment.

RESULTS

Two patients developed hepatoma within 6 months of entry in each group and were excluded. Another six patients in the sclerotherapy group and seven patients in the ligation group were excluded because of poor compliance or lost to follow-up. Therefore, 84 patients in each group were analyzed. In this long-term follow-up (55.3 +/- 12.5 months) the rebleeding rate for ligation was lower than that for sclerotherapy, regardless of whether the rebleeding was analyzed by patient number or Kaplan-Meier analysis. With regard to the rebleeding risk of various periods, the sclerotherapy risk was higher than that of ligation within 4 weeks of the initial endoscopic treatment or before variceal eradication. Multifactorial analysis showed hematemesis, poor hepatic function, and sclerotherapy were the risk factors determining rebleeding. The annual hepatocellular carcinoma incidence was 4.9%. There was no difference in survival between sclerotherapy and ligation. Multifactorial analysis showed that poor hepatic function was the only factor determining survival.

CONCLUSIONS

The rebleeding risk was higher in sclerotherapy than in ligation before variceal eradication, especially within 4 weeks of the initial endoscopic treatment. Long-term survival was dependent on hepatic reserve regardless of the treatment method.

Nitric oxide signaling pathway mediates the L-arginine-induced cardiovascular effects in the nucleus tractus solitarii of rats

We have previously demonstrated that L-arginine produces profound cardiovascular effects when microinjected into the nucleus tractus solitarii (NTS) of the rat. The present study extended our earlier work and examined further the underlying mechanisms of action of L-arginine in the NTS. Our results showed that intra-NTS microinjection of L-arginine (0.1-10 nmol) elicited dose-dependent depressor and bradycardic effects that were not significantly evoked by equivalent doses of D-arginine. The effects of L-arginine were blocked by pre-injection of 7-nitroindazole (0.02-1 nmol), a neuronal nitric oxide synthase inhibitor. Additionally, application of the calmodulin inhibitor W-7 (0.01-0.33 nmol) reduced cardiovascular responses to L-arginine (10 nmol) in a dose-dependent manner. Pre-injections of soluble guanylyl cyclase inhibitors, LY83583 (0.01-0.33 nmol) and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 0.03-1 pmol) both suppressed the L-arginine-induced depressor and bradycardic effects. Finally, the cardiovascular effects of L-arginine in the NTS were attenuated by HA1004 (0.1-1 nmol), a cGMP-dependent protein kinase inhibitor, but not by the protein kinase C inhibitor H-7 (1 nmol). Taken together, the results indicate that the cardiovascular effects produced by L-arginine in the NTS are inhibited by pharmacological interventions that block nitric oxide production and cGMP-PKG signaling pathway within the nucleus.

Aggregation inhibitory activity of minor acetophenones from Paeonia species

Two minor acetophenones, 2,5-dihydroxy-4-methoxy-acetophenone (2) and 2,5-dihydroxy-4-methylacetophenone (7) from Paeonia species were found to selectively inhibit the aggregation of rabbit platelets induced by arachidonic acid. They were more potent than the major compound, paeonol (1), and 7 also inhibited the formation of TXA2 and PGD2 from arachidonic acid.

The ileal brake: a fifteen-year progress report

The "ileal brake" is the primary inhibitory feedback mechanism to control transit of a meal through the gastrointestinal tract in order to optimize nutrient digestion and absorption. Neurohormonal factors mediating this response continue to be identified. Recently, additional brakes that fine-tune transit have been described. When gut traffic control is disrupted, pathologic states characterized by malabsorption and impaired drug bioavailability manifest as diarrhea and malnutrition. An understanding of the importance of these nutrient-triggered brakes provides essential clues to future treatments of chronic diarrhea, malnutrition, and drug malabsorption.

Serum uric acid levels in patients with cirrhosis: a reevaluation

It has been reported that the serum uric acid levels in patients with cirrhosis were decreased compared with healthy subjects. These studies suggested that the lower serum uric acid levels in cirrhotic patients were attributed mainly to an increased effective vascular volume, and consequently to an excessive renal clearance of uric acid. However, the previous observations are challenged by a recent hypothesis for the pathogenesis of hyperdynamic circulation and formation of ascites in cirrhosis. The current study was undertaken to reevaluate serum uric acid levels in patients with cirrhosis. Ninety-eight cirrhotic patients with normal renal functions were included in this study. All biochemical and hemodynamic data were utilized for analysis. The mean serum uric acid level (mean, 6.1+/-1.2 mg/dL; range, 2.7-9.1 mg/dL) was higher than that of the age- and sex-matched healthy control subjects (mean, 5.5+/-1.3 mg/dL; range, 2.9-8.1 mg/dL; p = 0.018). Using multiple regression analysis it was determined that the serum uric acid level was not related to the severity of liver disease, cardiac index, systemic vascular resistance, and hepatic venous pressure gradient but was related closely to age (r = 0.210, p = 0.026) and effective renal plasma flow (r = -0.677, p < 0.0001). Compared with cirrhotic patients without ascites, those with ascites had a significantly higher serum uric acid level (6.7+/-1.6 mg/dL vs. 5.6+/-1.7 mg/dL, p < 0.05) and lower effective renal plasma flow (396+/-125 mL/min vs. 445+/-149 mL/min, p < 0.05). In conclusion, for cirrhotic patients with normal serum creatinine levels, the current study shows that the mean serum uric acid level is higher than that of healthy control subjects. It is not related to the severity of liver failure and systemic and portal hemodynamics, but is related closely to renal functions, especially the renal plasma flow.

D-amphetamine-induced depletion of energy and dopamine in the rat striatum is attenuated by nicotinamide pretreatment

The present study examined the effects of nicotinamide on the D-amphetamine (AMPH)-induced dopamine (DA) depletion and energy metabolism change in the rat striatum. In chronic studies, co-administration of AMPH with desipramine, a drug that retards the metabolism of AMPH, (10 mg/kg, intraperitoneal [i.p.], respectively) caused a significant decrease of striatal DA content measured 7 days later. Pretreatment with nicotinamide (500 mg/kg, i.p.), the precursor molecule for the electron carrier molecule nicotinamide adenine dinucleotide (NAD), attenuated this effect of AMPH, whereas itself exerted no long-term effect on striatal DA content. In acute studies, a decrease in striatal adenosine triphospate/adenosine diphosphate (ATP/ADP) ratio was found 3 h after co-injection of AMPH and desipramine. However, nicotinamide pretreatment blocked the reduced striatal ATP/ADP ratio and resulted in a striking increase in striatal NAD content in AMPH-treated rats. Furthermore, nicotinamide was noted to increase striatal ATP/ADP ratio and NAD content in saline-treated rats. These findings suggest that nicotinamide protects against AMPH-induced DAergic neurotoxicity in the striatum of rats via energy supplement.

Increased progenitor cell proliferation in the peripheral blood of patients with bronchial asthma: the role of nitric oxide

BACKGROUND

Asthma exacerbation is associated with increased numbers of circulating CD34(+) progenitor cells, which may migrate to airways and develop into mature cells under the effects of cytokines and hematopoietic factors. Nitric oxide (NO) generation is enhanced in asthma and is known to suppress human hematopoiesis.

OBJECTIVES

We studied circulating progenitor cells in the blood of patients with varying severity of asthma and examined the contribution of NO to their proliferation into eosinophil-forming colonies ex vivo.

METHODS

With use of multiparameter flow cytometric analyses, the cell numbers and intracellular inducible NO synthase (iNOS) immunoreactivity of circulating CD34(+) cells in peripheral blood was measured. The serum level of GM-CSF or IL-5 was also determined. The colonies grown from progenitor cells were cultured in methylcellulose either in the presence or absence of growth factors, including GM-CSF, stem cell factor, and IL-3.

RESULTS

A significantly greater number of circulating CD34(+) cells increased together with higher intracellular iNOS immunoreactivity in moderate asthmatics compared with mild intermittent asthmatics and healthy subjects. There was no significant difference in iNOS immunoreactivities or CD34(+) progenitor cell numbers between healthy subjects and those with mild intermittent asthma. Serum levels of GM-CSF or IL-5 were significantly higher in all asthmatics compared with healthy subjects and correlated with circulating CD34(+) cells. A greater number of colonies was grown either in the presence or absence of growth factors with a higher percentage of cells of eosinophil lineage in asthmatics than in health subjects. N(G)-nitro-L-arginine methyl ester potentiated and sodium nitroprusside inhibited the colony growth in both asthmatic and healthy subjects without a significant change in the percentage of eosinophil lineage.

CONCLUSIONS

The production of NO from progenitor cells or other circulating cells may act in an autocrine or paracrine fashion to regulate progenitor cell growth and colony formation. However, this is not sufficient to control the increased proliferation of progenitor cells observed in asthma.

Effects of vasopressin on portal-systemic collaterals in portal hypertensive rats: role of nitric oxide and prostaglandin

This study investigated the effect of vasopressin on portal-systemic collaterals in portal hypertensive rats and the influence of nitric oxide (NO) and prostaglandin on the responsiveness of collateral vessels to vasopressin. The vascular responsiveness to graded concentrations of vasopressin was tested with or without the incubation of n(omega)-nitro-L-arginine (NNA) (100 micromol/L) and/or indomethacin (10 micromol/L) in perfused collateral vascular beds of rats with portal hypertension induced by partial portal vein ligation. In addition, concentration-response curves to vasopressin with incubation of a vasopressin V(1) receptor antagonist d(CH(2))(5)Tyr(Me) arginine vasopressin and concentration-response curves to a V(2) receptor agonist 1-desamino-8-D-arginine vasopressin were performed. Vasopressin significantly increased the perfusion pressure of collaterals, and this effect was suppressed by the addition of the V(1) receptor antagonist. Perfusion with the V(2) receptor agonist had no effect on the collaterals. Incubation with NNA, indomethacin, or both significantly potentiated the response of collaterals to vasopressin. In addition, the pressor response to vasopressin in the combination group was significantly higher than that in the NNA-alone group. The results show that vasopressin produces a direct vasoconstrictive effect on the portal-systemic collaterals of portal hypertensive rats. This effect is mediated by the vasopressin V(1,) but not V(2), receptors. The attenuation of the response to vasopressin by NO and prostaglandin suggest a function role of both mediators in the regulation of the portal-systemic collateral circulation in portal hypertensive rats.

Effects of sustained-release lanreotide on hemodynamics in rats with portal vein stenosis

BACKGROUND/AIMS

Somatostatin and its analogue have been shown to provide beneficial effects in the management of portal hypertension and hyperdynamic circulation. The current study was undertaken to evaluate the effects of lanreotide, a sustained-release somatostatin analogue, on hemodynamics in rats with portal hypertension.

METHODS

Immediately after portal vein stenosis, rats were randomly assigned to receive vehicle or a single intramuscular injection of lanreotide 10 mg/kg. Hemodynamic measurements (radioactive microsphere technique) with portal systemic shunts determinations were performed on the 4th and 8th day after surgery, respectively.

RESULTS

On the 4th day after surgery, rats treated with lanreotide had significantly lower cardiac index and higher systemic vascular resistance than rats treated with vehicle, while these values were no different on the 8th day after portal vein stenosis. In contrast, the elevation of portal pressure, portal tributary blood flow, and splanchnic fraction of cardiac output had ameliorated following lanreotide administration associated with an increase in splanchnic arterial resistance. Portal systemic shunts were lower in rats receiving lanreotide than in rats receiving vehicle.

CONCLUSION

The current study showed that a single injection of sustained-release lanreotide in rats with portal vein stenosis delayed the development of peripheral arterial vasodilatation and hyperdynamic circulation, while it modified the evolution of portal hypertension and splanchnic hyperemia. This treatment also prevents, in part, the development of portal systemic shunts in rats with portal vein stenosis.

Neutrophil adherence to lung epithelial cells induce interleukin-8 release

BACKGROUND

Neutrophil recruitment to the lungs and transmigration through the pulmonary epithelium to reach the respiratory tract are characteristics of airway inflammation. Interleukin-8 (IL-8) plays a critical role in the recruitment of neutrophils to epithelial cells. We investigated the effect of neutrophil adherence to epithelial cells on cytokine secretion.

METHODS

The production of IL-8 from cultured A549 epithelial cells was assayed and neutrophil adherence assay in the presence or absence of interferon-gamma (IFN-gamma) plus tumor necrosis factor-alpha (TNF-alpha) plus interleukin-1 beta (IL-1 beta) stimulation was studied on cultured A549 epithelial cells. The role of an adhesion molecule in the modulation of neutrophil adherence was examined by pretreatment with intercellular adhesion molecule-1 (ICAM-1) blocking antibody.

RESULTS

There was an increase in IL-8 release from epithelial cells that was time-dependent and in the magnitude of neutrophil adherence to the epithelial cells. Stimulation of epithelial cells with IFN-gamma +TNF-alpha +IL-1 beta significantly increased IL-8 release and neutrophil adherence. The spontaneous or IFN-gamma +TNF-alpha +IL-1 beta-induced IL-8 release was significantly augmented after the addition of neutrophils. The inhibition of neutrophil adherence to epithelial cells by ICAM-1 blocking antibody downregulated the augmented release of IL-8 with or without IFN-gamma +TNF-alpha +IL-1 beta stimulation. Placing a membrane filter on cultured epithelial cells to prevent neutrophil adherence significantly decreased IL-8 release from epithelial cells with IFN-gamma +TNF-alpha +IL-1 beta stimulation.

CONCLUSION

Our results indicate that lung epithelial cells not only provide a harboring site for neutrophils to be activated, but also amplify the neutrophil sequestration in the lung by releasing IL-8. Moreover, the release of IL-8 is dependent on the adherence between neutrophils and lung epithelial cells.

Early dexamethasone therapy and blood cell count in preterm infants

OBJECTIVE

To assess the effects of early postnatal dexamethasone therapy on hematologic values in preterm infants.

MATERIALS AND METHODS

We reviewed the hematologic data of 179 preterm infants who participated in a double-blind clinical trial of early postnatal dexamethasone therapy (<12 hours after birth) for the prevention of chronic lung disease. One group (86 infants) received saline and the other group (93 infants) received dexamethasone. Dexamethasone was given intravenously every 12 hours in tapering doses: 0.25 mg/kg on days 1 to 7, 0.12 mg/kg on days 8 to 14, 0.05 mg/kg on days 15 to 21, and 0.02 mg/kg on days 21 to 28. Blood samples were obtained on days 0, 3, 7, 10, 14, 21, and 28. None of the infants received prenatal steroid therapy.

RESULTS

Multiple regression analysis revealed significant differences in the values versus time curves of the white blood cell, neutrophil, lymphocyte, basophil, and eosinophil counts between the two groups. The white blood cell count was significantly higher in the dexamethasone group on days 7 through 14, and this was associated with significantly higher numbers of segmented neutrophils and band forms and significantly lower numbers of lymphocytes and eosinophils. The hematocrit and platelet counts were similar in the two groups throughout most of the trial. Except for platelet count, steroid therapy did not alter the hematologic values for infants with bacteremia.

CONCLUSION

Dexamethasone affects white blood cell, segmented neutrophil, lymphocyte, basophil, and eosinophil counts in neonates. This should be taken into consideration when evaluating preterm infants who are receiving dexamethasone.early dexamethasone therapy; neonatal blood count; preterm infant; respiratory distress syndrome.

Penicillin-nonsusceptible Streptococcus pneumoniae infections in children

The emergence of penicillin-nonsusceptible Streptococcus pneumoniae (PNSSP) has brought a new clinical challenge. In Taiwan, reports of the prevalence and clinical features of PNSSP infections in children are limited. This study reviewed the resistance patterns of all clinical isolates of S. pneumoniae obtained from patients under 17 years of age from January 1993 through July 1998 in a medical center. Their clinical features and treatment responses were analyzed, with special attention paid to those patients with invasive PNSSP infections. Totally, 170 clinical isolates of S. pneumoniae were obtained from 168 patients aged under 17 years. Among those infections, there were 56 sinusitis (including 4 sinusitis with bacteremia), 44 pneumonia (including 23 pneumonia with bacteremia or empyema), 23 otitis media (including 5 otitis media with bacteremia), 9 simple bacteremia, 9 conjunctivitis, 8 meningitis, 4 peritonitis, 3 skin infections and the other 14 isolates were colonization. One hundred eleven isolates (65.3%) showed reduced penicillin susceptibility by the disk diffusion method. A trend of increasing percentiles of PRSP was noted: 27.3% (3/11) in 1993, 37.5% (9/24) in 1994, 55.5% (10/18) in 1995, 77.5% (31/40) in 1996, 66.0% (31/47) in 1997, and 87.1% (27/31) in 1998. Minimum inhibitory concentration (MIC) determinations by the E-test showed some of the isolates were intermediately resistant. Prior antibiotic usage was associated with a higher incidence of PNSSP infections. However, most children responded well to antimicrobial treatment.

Chemistry and biological activities of constituents from Morus australis

A novel constituent named australone B (1) was further isolated from the cortex of Morus australis (Moraceae). The structure of 1 has been elucidated by one- and two-dimension spectra. In human citrated platelet-rich plasma, 1 showed strong inhibition of aggregation induced by adrenaline in a concentration-dependent manner with an IC(50) value of about 33.3 microM. Compound 1 (30 microM) also showed inhibitory effects on superoxide anion formation from rat neutrophils stimulated with formyl-Met-Leu-Phe (fMLP)/cytochalasin B (CB). Morusin (2) inhibited superoxide anion formation from rat neutrophils stimulated with phorbol myristate acetate (PMA) in a concentration-dependent manner with an IC(50) value of 66.9+/-2.5 microM.

Beneficial effects of combined terlipressin and tetramethylpyrazine administration on portal hypertensive rats

The purpose of this study was to investigate the therapeutic effects of terlipressin (TP) alone or in combination with tetramethylpyrazine (TMP) on anesthetized portal hypertensive rats. Portal hypertension was induced by either partial portal vein ligation (PVL, without cirrhosis) or bile duct ligation (BDL, with cirrhosis) in Sprague-Dawley rats. Each PVL or BDL rat received only one of the two regimens: vehicle for 3 min followed by TP (0.017 mg x kg(-1) x min(-1) for 3 min) or TMP (10 mg x kg(-1) x min(-1) for 3 min) followed by TP. In PVL rats, infusion of vehicle followed by TP induced significant reduction of portal venous pressure (PVP, -15.0+/-1.0%) and prominent elevation of mean arterial pressure (MAP, 57.3+/-8.1%) as well as total peripheral resistance (TPR, 113+/-11%) from baseline, and there was a cardiodepressant response (cardiac index, CI, -26.3+/-1.1%). Infusion of TMP followed by TP induced significant reduction of PVP (-20.3+/-0.4%) and CI (-9.9+/-1.2%) and significant elevation of MAP (31.3+/-2.5%) and TPR (46.0+/-4.1%) from baseline. In BDL rats, infusion of vehicle followed by TP also induced significant reduction of PVP (-13.8+/-1.7%) but an increase in MAP (57.1+/-2.2%) and TPR (101+/-6%) from baseline, and there also was a cardiodepressant response (CI, -21.4+/-2.3%). Infusion of TMP followed by TP induced significant reduction of PVP (-18.9+/-1.4%) and CI (-11.9+/-2.1%), but an increase in MAP (36.2+/-2.5%) and TPR (55.0+/-5.2%). Compared with vehicle followed by TP, TMP not only significantly enhanced portal hypotensive (PVP reduction) effects of TP but also attenuated the systemic pressor (MAP and TPR elevation) and cardiodepressant (CI reduction) effects of TP in both PVL and BDL rats. Our results suggest that TP, alone or in combination with TMP, induced portal hypotensive effects in two models of portal hypertensive rats. Combination of TP and TMP was beneficial in enhancing portal hypotensive effects of TP and ameliorating the systemic pressor and cardiodepressant effects of TP.

Modulation of cardiovascular effects produced by nitric oxide and ionotropic glutamate receptor interaction in the nucleus tractus solitarii of rats

Both nitric oxide (NO) and glutamate in the brain stem nuclei are involved in central cardiovascular regulation. In the present study, we investigated possible functional interactions between NO and glutamate in the modulation of cardiovascular function in the nucleus tractus solitarii (NTS) of anesthetized rats. In Sprague-Dawley rats, intra-NTS unilateral microinjections of L-glutamate (0.1 nmol/60 nl) and its ionotropic agonists NMDA (5 pmol) and AMPA (2 pmol) resulted in significant decreases in mean blood pressure (MBP) and heart rate (HR). The cardiovascular effects of L-glutamate, NMDA and AMPA were significantly blocked by prior administration of the neuronal NO synthase (nNOS) inhibitor, 7-nitroindazole (7-NI, 0.5 nmol), or by the soluble guanylyl cyclase (sGC) inhibitor, 1H-[1.2.4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ, 0.03-1 pmol). Conversely, a depressor and bradycardic effect was elicited by microinjection of either the NO precursor L-arginine (10 nmol) or the NO donor sodium nitroprusside (SNP, 0.2 nmol) into the NTS. Prior administration of the NMDA receptor antagonists MK-801 (0.1-1 nmol) and APV (0.1-4 nmol) significantly attenuated these effects of L-arginine. Similarly, cardiovascular responses to L-arginine in the NTS were inhibited by pre-injections with the non-NMDA receptor antagonists CNQX (10-330 pmol) and NBQX (2-10 pmol). Furthermore, APV (4 nmol) and CNQX (330 pmol) attenuated the depressor and bradycardic effects of SNP, respectively. This study demonstrates that baroreflex-like responses to microinjections of L-glutamate and its ionotropic agonists into the NTS involve synthesis of NO and activation of sGC. Reciprocally, central cardiovascular effects of NO also depend on responsive ionotropic glutamate receptors.

Experimental assessment of the feasibility of integrating an endoscopic imaging system into an existing hospital information system

The National Cheng Kung University (NCKU) Hospital operates a comprehensive integrated hospital information system. This was designed and installed as an integral component of the building of the hospital, which opened in 1988. The information system provides a service to all staff in the hospital, administrative and clinical, across the whole of the hospital. To make sure that the information is accessible, where and when it is needed, a comprehensive communications network consisting of both hardware and software mechanisms supports the information system. This paper explores the requirements for a computerised image system for endoscopy and assesses two approaches to the implementation of such a system, as a stand-alone system and as a subsystem of the NCKU hospital information system already in place. The latter would satisfy the original design specification of developing a single system to cover all aspects of hospital operation but places additional demands on the endoscopy systems designer to ensure integration. Both operational modes are set out in the paper and their implications assessed.

Hemostatic changes in patients with liver cirrhosis

BACKGROUND

Hemostatic changes in liver disease are complicated. An overall evaluation of the main hemostatic parameters in patients with different degrees of cirrhosis of the liver has not been reported in Taiwan.

METHODS

A series of hemostatic tests and parameters including activated partial thromboplastin time, prothrombin time, thrombin time, bleeding time, factor VIII assay, antithrombin activity, fibrinogen, plasminogen, protamine sulfate test, fibrin(ogen) degradation products, D-dimer, thrombin-antithrombin complex (measured by modified antithrombin), tissue plasminogen activator (tPA), plasminogen activator inhibitor-1, euglobulin lysis test and venous occlusion test were performed in 51 patients with cirrhosis of the liver and 33 healthy controls. Among the cirrhotics, 18 were classified as Child-Pugh group A, 16 were B and 17 were C.

RESULTS

Plasminogen, antithrombin and platelet count decreased progressively, starting with group A, then B and then C, relative to the controls. Factor VIII, activated partial thromboplastin time, prothrombin time, bleeding time, D-dimer and fibrin(ogen) degradation products increased progressively starting with group A, to B and then C, relative to controls. Severity of cirrhosis correlated with hemostatic changes. No significant change in the fibrinolytic response after challenge with the venous occlusion test was found in either Child-Pugh groups A, B, C or the controls, though progressive increases in tPA were found starting with group A, to B and then C, relative to controls.

CONCLUSIONS

Our study proved a close relationship between the severity of cirrhosis and hemostatic changes. Activated partial thromboplastin time was better than bleeding time or thrombin time to demonstrate the severity of liver damage and hemostatic change in cirrhosis. Because the deterioration of coagulation function and increased fibrinolytic activity paralleled the severity of liver cirrhosis, adequate treatment for cirrhotic bleeding should not only correct the coagulation defects, but should also lower the increasing fibrinolytic activity.

Evidence against a role for endotoxin in the hyperdynamic circulation of rats with prehepatic portal hypertension

BACKGROUND/AIMS

Excessive formation of nitric oxide may mediate the generalized vasorelaxation and hyporesponsiveness to vasoconstrictors observed in portal hypertensive states. Endotoxin, released from the bowel and detoxified by the liver, could stimulate inducible nitric oxide synthase directly or indirectly via the cytokine cascade. This study investigated the effect of chronic intraperitoneal injection of polymyxin B, a neutralizing antagonist of endotoxin, on the hemodynamics of partially portal vein-ligated (PVL) rats.

METHODS

Concomitantly with endotoxin (600 EU) and dactinomycin (80 microg), polymyxin B (0.1 mg) or normal saline (N/S) was administered via an intraperitoneal route to male Sprague-Dawley rats. Twenty-four hours later, mean arterial pressure was determined. In PVL rats polymyxin B (0.1 mg in 5 cc N/S) or N/S was given intraperitoneally twice daily from 2 days prior to operation until 5 days (short-term) or 14 days (long-term) after the operation. Long-term polymyxin B- or N/S-treated sham-operated rats were included as controls. Hemodynamic studies with a thermodilution technique were performed at the end of treatment. Blood samples were collected from another series of PVL rats with long-term treatment to determine plasma levels of endotoxin and tumor necrosis factor-alpha. Plasma levels of endotoxin and tumor necrosis factor-alpha were measured by Limulus assay and the ELISA method, respectively.

RESULTS

With the dosage of 0.1 mg polymyxin B, hypotension in rats subjected to endotoxin and dactinomycin administration could be corrected (polymyxin B vs. placebo: 130.0+/-7.7 vs. 108.8+/-6.7 mm Hg, p<0.05). However, long-term or short-term treatment with the same dosage of polymyxin B failed to ameliorate the hyperdynamic circulation of PVL rats. In addition, long-term treatment with polymyxin B did not change systemic and portal hemodynamics in sham-operated rats. Plasma levels of endotoxin and tumor necrosis factor-alpha were comparable in PVL rats treated with long-term polymyxin B or N/S (p>0.05).

CONCLUSIONS

Our findings do not support the role of endotoxin in the hyperdynamic circulation of PVL rats.

Prevalence of antimicrobial resistance among clinical isolates of Haemophilus influenzae in Taiwan

The purpose of this study was to determine the prevalence of resistance to various antimicrobial drugs among Haemophilus influenzae isolates in Taiwan. Two hundred and ninety-six clinical isolates of H. influenzae were prospectively obtained from nine teaching hospitals throughout Taiwan, from June 1994 to April 1995. All isolates were examined for the presence of type b encapsulation and beta-lactamase production. Antibiotic susceptibility was determined by means of standard broth microdilution procedures. Twenty-three isolates (7.8%) were type b, and the overall rate of beta-lactamase production was 58.1% (172/296). The rates of resistance to antibiotics were 58.1% for ampicillin, 33.8% for trimethoprim-sulfamethoxazole, 20.6% for chloramphenicol, 27% for tetracycline, 6.7% for azithromycin, 3.4% for cefaclor, and 0.3% for cefuroxime. Cefixime, ceftriaxone, and ciprofloxacin were active against all H. influenzae isolates. Thirty (10.1%) of the 296 isolates were resistant to three drugs (ampicillin, chloramphenicol, and tetracycline), 16 of which (5.4%) were resistant to four drugs (ampicillin, chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole). There was a marked increase in the rates of ampicillin resistance and beta-lactamase production among H. influenzae isolates compared with a previous survey in Taiwan conducted 9 years ago. In addition, isolates with multiple drug resistance were also identified. Continued efforts are needed to monitor antibiotic resistance patterns of H. influenzae in the region.

Systemic administration of lipopolysaccharide induces release of nitric oxide and glutamate and c-fos expression in the nucleus tractus solitarii of rats

There is increasing recognition that communication pathways exist between the immune system and brain, which allows bidirectional regulation of immune and brain responses to infection. The endotoxin lipopolysaccharide (LPS) has been reported to elicit release of cytokines and expression of inducible nitric oxide synthase (iNOS) in peripheral organs. Whereas LPS given systemically causes endotoxic shock, little is known about its central nervous system action, particularly the induction of iNOS. Nitric oxide (NO) and glutamate in the nucleus tractus solitarii (NTS) are important mediators of central cardiovascular regulation. We have previously demonstrated that intravenous injections of LPS increased the NO precursor L-arginine-induced depressor effect in the NTS. The present study investigated further the effects of LPS on the release of NO and glutamate in the NTS and the expression of c-fos, an immediate early response gene product, in neural substrates for central cardiovascular control. In vivo microdialysis coupled with chemiluminescence and electrochemical detection techniques were used to measure extracellular levels of NO and glutamate in the rat NTS. Immunohistochemistry was used for the examination of c-fos protein expression. We found that intravenous infusion of LPS (10 mg/kg) produced a biphasic depressor effect, with an early, sharp hypotension that partially recovered in 15 minutes and a secondary, more prolonged hypotension. In the NTS, a progressive increase of extracellular glutamate and NO levels occurred 3 and 4 hours after LPS was given, respectively. The effects of LPS on the induction of delayed hypotension and NO formation in the NTS were abolished by pretreatment with the iNOS inhibitor aminoguanidine. Finally, c-fos protein expression in the NTS and related structures for cardiovascular regulation was observed after LPS challenge. Taken together, these data suggest that an endotoxin given systemically can elicit delayed increases of glutamate release and iNOS-dependent NO production in the NTS and activate the central neural pathway for modulating cardiovascular function.

Spider angiomas in patients with liver cirrhosis: role of alcoholism and impaired liver function

BACKGROUND

Spider angioma is a common sign in patients with liver cirrhosis, but the pathogenesis is still unclear. Alcohol and hyperestrogenemia are both possible etiologies. This study was designed to investigate the relationship of spider angiomas in patients with liver cirrhosis to alcohol, liver function test results, and plasma levels of sex hormones.

METHODS

Eighty-two patients with liver cirrhosis and 18 healthy subjects were enrolled in this study. The number, size, and location of the spider angiomas were recorded for all subjects. Plasma levels of estradiol and testosterone were measured.

RESULTS

Cirrhotic patients had significantly higher estradiol/testosterone ratios (26.8 +/- 5.1 x 10(-3) versus 8.8 +/- 2.0 x 10(-3); P = 0.002) than healthy controls. Twenty-seven (33%) of the 82 cirrhotic patients had spider angiomas. Cirrhotic patients with spider angiomas were younger (56 +/- 3 versus 66 +/- 1 years; P = 0.002) and had higher serum bilirubin levels (3.3 +/- 0.6 versus 1.7 +/- 0.2 mg/dl; P = 0.002), longer prothrombin time (16.8 +/- 0.8 versus 14.8 +/- 0.4 sec; P = 0.01), and higher prevalence of alcoholism (41% versus 20%; P = 0.04) than those without. Stepwise logistic regression showed that alcoholism and serum bilirubin level were the only significant and independent predictors associated with the presence of spider angiomas in cirrhotic patients (odds ratio = 3.5; 95% confidence interval = 1.2-10.8; P = 0.03, and odds ratio = 2.8; 95% confidence interval = 1.3-5.7; P = 0.006, respectively).

CONCLUSIONS

Alcoholism and impaired liver function are important predictors of the presence of spider angiomas in patients with liver cirrhosis.

Effects of octreotide on central hemodynamics and systemic oxygen use in patients with viral cirrhosis

OBJECTIVE

Octreotide has potentially beneficial effects in patients with cirrhosis. However, the effects of octreotide on central hemodynamics and oxygen use have not been established. The present study was undertaken to evaluate the effect of octreotide on central hemodynamics and oxygen use in patients with viral cirrhosis.

METHODS

Twenty-five patients with cirrhosis were enrolled in the study. They were randomly assigned to receive either placebo (n = 10) or a continuous infusion of 100 microg/h of octreotide after an initial 100-microg bolus (n = 15). Hemodynamic measurements and oxygenation values were obtained before and 60 min after octreotide or placebo administration.

RESULTS

Placebo administration did not have any effect on hemodynamic and oxygenation values. In patients who received octreotide, systemic hemodynamic values including cardiac index, mean arterial pressure, and systemic vascular resistance were not affected. The mean pulmonary arterial pressure tended to increase after octreotide administration but was statistically insignificant. There was a significant increase in pulmonary arterial vascular resistance, whereas the pulmonary capillary wedge pressure and right atrial pressure were significantly decreased. Arterial oxygen tension, systemic oxygen uptake, and oxygen extraction ratio were significantly decreased after octreotide administration, whereas oxygen transport as well as arterial and mixed venous oxygen contents remained unchanged.

CONCLUSIONS

In patients with viral cirrhosis, octreotide administration exerted a significant effect on pulmonary circulation. It also resulted in a decrease in systemic oxygen uptake and oxygen extraction ratio. These results suggested that octreotide may impair tissue oxygenation in patients with viral cirrhosis.

Portal hypotensive effects of combined terlipressin and DL-028, a synthetic alpha 1 adrenoceptor antagonist administration on anesthetized portal hypertensive rats

AIMS/BACKGROUND

The purpose of this study was to investigate the therapeutic effects of terlipressin, alone or in combination with DL-028, a synthetic alpha 1-adrenoceptor antagonist on anesthetized portal hypertensive rats.

METHODS

Portal hypertension was induced by either partial portal vein ligation (PVL) or bile duct ligation (BDL) in Sprague-Dawley rats. Each portal hypertensive rat received only one of the two regimens: vehicle plus terlipressin or DL-028 plus terlipressin. Terlipressin dosage was 0.017 mg/kg/min infused for 3 min, while vehicle or DL-028 (0.50 microgram/kg/min) was continuously infused for 40 min, starting 10 min before terlipressin infusion.

RESULTS

In PVL rats, infusions of vehicle plus terlipressin induced significant, maximum reduction of portal venous pressure (PVP, -11.0 +/- 1.8%) and prominent elevation of mean arterial pressure (MAP, 50.3 +/- 9.0%) from baseline. Infusions of DL-028 plus terlipressin induced maximum PVP reduction (-17.5 +/- 2.8%) and MAP elevation (39.8 +/- 7.4%). In BDL rats, infusion of vehicle plus terlipressin also induced significant, maximum reduction of PVP (-6.8 +/- 2.1%) and prominent elevation of MAP (61.4 +/- 7.8%) from baseline. Infusions of DL-028 plus terlipressin induced maximum PVP reduction (-17.9 +/- 2.2%) and MAP elevation (47.9 +/- 7.4%). Compared to vehicle plus terlipressin, DL-028 significantly enhanced portal hypotensive effects of and attenuated systemic pressor effects of terlipressin in both PVL and BDL rats.

CONCLUSIONS

Our results suggest that terlipressin, alone or in combination with DL-028, induced portal hypotensive effects in portal hypertensive rats. The combination of terlipressin with DL-028 was beneficial in enhancing the portal hypotensive effects and ameliorating the systemic pressor effects of terlipressin.

Effect of anaemia on haemodynamics in patients with cirrhosis

BACKGROUND

It has been suggested that increased blood haemoglobin attenuates splanchnic vasodilatation in portal-hypertensive rats by nitric oxide inactivation. However, the haemodynamic effect of anaemia in cirrhotic patients of varying severity has been rarely discussed. The aim of this study was to evaluate the influence of anaemia on systemic and splanchnic haemodynamics in cirrhotic patients of differing severity.

METHODS

Two hundred and twenty-five cirrhotic patients were included in this study. All biochemical and haemodynamic results were utilized for analysis. Anaemia was defined as a haemoglobin level below the cut-off value of 12 g/dL, which might best predict low systemic vascular resistance.

RESULTS

Compared with non-anaemic patients, anaemic patients had decreased mean arterial pressure (90 +/- 1 vs 95 +/- 1 mmHg, P = 0.002), and decreased systemic vascular resistance (1022 +/- 25 vs 1227 +/- 30, P < 0.0001), and increased cardiac index (4.3 +/- 0.1 vs 3.8 +/- 0.1 L/min per m2, P < 0.0001) and increased hepatic venous pressure gradient (16.7 +/- 0.5 vs 14.4 +/- 0.6 mmHg, P = 0.006). Haemoglobin concentration exerted an influence on the degree of vasodilatation in cirrhotic patients, with Child-Pugh's A class (but not in Child-Pugh's B and C classes), and in patients without ascites (but not in patients with ascites).

CONCLUSIONS

It was concluded that anaemia has a negative effect on hyperdynamic circulation in patients with early cirrhosis which is not observed in patients with advanced cirrhosis.

Plasma concentrations of interferon-alpha in patients with liver cirrhosis: relationship to systemic and portal hemodynamics

BACKGROUND

Nitric oxide (NO) plays an important role in the pathogenesis of the hyperdynamic circulation observed in portal hypertensive states. Interferon (IFN)-alpha can stimulate NO formation directly or indirectly via cytokines. However, IFN-alpha concentrations seem to increase or decrease in cirrhotic patients. This study investigated the plasma concentration of IFN-alpha in patients with cirrhosis and its relationship to systemic and portal hemodynamics.

METHODS

Thirty-six patients with cirrhosis and 47 healthy controls had blood samples taken for the determination of plasma concentrations of IFN-alpha by enzyme-linked immunosorbent assay. Systemic and portal hemodynamics were measured in patients with cirrhosis on the same day of blood sampling using Swan-Ganz catheterization and the thermodilution technique.

RESULTS

As compared with healthy subjects, patients with cirrhosis demonstrated a significantly higher IFN-alpha detectable rate (> 3 pg/ml, 14.9% vs 36.1%, p < 0.05). In cirrhotic patients, the IFN-alpha detectable rates were similar between those with and without decompensation, a hepatic venous pressure gradient greater than 12 mmHg, or the presence of large esophageal varices (p > 0.05). There was no significant difference in the systemic vascular resistance or hepatic venous pressure gradient between cirrhotic patients with and without a detectable plasma IFN-alpha concentration.

CONCLUSIONS

Plasma IFN-alpha concentrations tended to increase in patients with cirrhosis. However, IFN-alpha concentrations do not play a role in the hyperdynamic circulation observed in patients with cirrhosis.

Isolation of Japanese encephalitis virus from mosquitoes collected in Northern Taiwan between 1995 and 1996

Mosquito collections were carried out from May to October in 1995 and 1996 at Yingko and Sanhsia of Taipei County and Chunan of Miaoli County. A grand total of 13,576 mosquitoes consisting of 13 species in 407 pools were processed and inoculated into Aedes albopictus clone C6/36 cell cultures. One hundred thirty seven pools of these showed the presence of viral antigens in the infected C6/36 cell lysates which were identified by the indirect fluorescent antibody test using a monoclonal antibody against Japanese encephalitis (JE) virus. The postive pools, were divided into 97, 20, 1, 8, 1, 1, 7, and 2 pools from Culex tritaeniorhynchus Giles, Aedes albopictus Skuse, Aedes vexans nocturnus (Theobald), Armigeres subalbatus (Coquillett), Culex annulus Theobald, Culex fuscanus Wiedemann, Culex quinquefasciatus Say, and Culex sitiens Wiedemann respectively. The dominant species collected at night was Culex tritaeniorhynchus, while Aedes albopictus was the dominant species collected in daytime. Besides the pigpens, avian habitats are also a dominate source of JE virus in this study.

Muscle phosphofructokinase deficiency (Tarui's disease): report of a case

A 14-year-old girl had an acute episode of rhabdomyolysis after vigorous exercise and seizures. Laboratory studies revealed elevated creatine phosphokinase (CPK) activity and myoglobinuria without acute renal failure, as well as mild indirect hyperbilirubinemia, and hyperuricemia. The elevated CPK activity, mild indirect hyperbilirubinemia, and hyperuricemia persisted during a 10-month follow-up period, during which chronic hemolysis without overt anemia was also noted. A muscle biopsy specimen from the left biceps muscle revealed occasional muscle fiber necrosis and mild excess of glycogen accumulation on periodic acid-Schiff staining. Histochemical reactions were negative with phosphofructokinase (PFK) stain when fructose-6-phosphate was used as the substrate, but positive when fructose 1,6-bisphosphate was used as the substrate. These findings confirmed the diagnosis of muscle PFK deficiency (Tarui's disease), which is a defect of glycolysis in muscles and erythrocytes. Less than 40 such patients have been reported to date. When a specific metabolic myopathy is suspected in children with rhabdomyolysis, symptoms of hemolysis should also be sought to identify Tarui's disease. To the best of our knowledge, this is the first case of Tarui's disease identified in Taiwan.

Influence of perinatal factors on limit of viability in extremely low birth weight infants

This retrospective study investigated the influence of perinatal factors on the limit of viability in extremely low birth weight (ELBW) infants. From January 1997 to May 1998, all infants weighing less than 1000 gm admitted to NICU of China Medical College Hospital were enrolled in this study. Still-born infants and infants with congenital anomaly were excluded. The end outcome was survival of the infants (defined as alive at discharge). Eighty-four infants were included in this study. Their mean gestational age (GA) was 25.8 +/- 1.76 weeks, mean birth weight (BW) was 772 +/- 114 gm, and overall survival rate was 48.8%. The smallest intact survival was a female infant of GA 23 weeks and BW 530 gm. Early neonatal mortality rate (< 7 days) was 26.2% (23/84). The cut off levels, below which mortality significantly increased, were GA < 24 weeks and BW < 700 gm (odds ratio, 6.11, confidence interval, 2.01 to 18.63 for GA; odds ratio, 2.65, confidence interval, 1.09 to 6.39 for BW). The two most significant factors which independently affected neonatal survival were GA < 24 weeks and early neonatal dexamethasone treatment for the prevention of chronic lung disease (odds ratio, 9.24, confidence interval, 2.53 to 33.76 for GA; odds ratio, 35.83, confidence interval, 7.03 to 183 for dexamethasone treatment). We conclude that in order to further reduce neonatal mortality, efforts should be made in the areas of prenatal care and women's health to prevent extreme prematurity and low birth weight infants. In the case of an impending delivery of an ELBW infant, an active plan of management for all gestations > or = 24 weeks seems appropriate. Finally, unless it is proven to be safe, early neonatal dexamethasone treatment for prevention of chronic lung disease should not be routinely used in ELBW infants.