Effects of early postnatal dexamethasone therapy on calcium homeostasis and bone growth in preterm infants with respiratory distress syndrome

The effects of dexamethasone therapy on calcium homeostasis and bone growth were evaluated in 49 infants (24 placebo and 25 dexamethasone) who participated in a double-blind trial of early dexamethasone therapy for the prevention of chronic lung disease. Dexamethasone (0.25 mg kg(-1) b.i.d. on d 1-7; 0.12 mg kg(-1) b.i.d. on d 8-14; 0.05 mg kg(-1) b.i.d. on d 15-21; 0.02 mg kg(-1) b.i.d. on d 22-28) or saline placebo was given i.v. Serum calcium (Ca), phosphorus (P) and parathyroid hormone (PTH), and the corresponding urinary excretion of calcium (FECa) and phosphorus (FEP) were measured on d 2, 3, 7, 10, 14, 21 and 28 after starting the study. Radiographic evaluations of bone growth were also evaluated. Infants in the dexamethasone group had significantly higher PTH on d 2 (p < 0.01), 7 and 14 (p < 0.05) than infants in the placebo group. The dexamethasone-treated infants also had significantly higher FEP on d 2, 7 and 14 (p < 0.05) and lower FECa on d 7 and 14 (p < 0.05) than control infants. There was no significant difference between the groups in bone growth during the study. It was concluded that early dexamethasone therapy causes a transient elevation in PTH without apparent change in bone growth. The long-term effect remains to be evaluated further.

Application of random amplified polymorphic DNA analysis to differentiate strains of Salmonella typhi and other Salmonella species

A Random Amplified Polymorphic DNA (RAPD) fingerprinting method was developed to differentiate isolates of Salmonella serotype typhi (S. typhi) and other Salmonella isolates. A panel of five primers was used to examine 63 isolates of Salm. typhi, including 56 strains isolated in Taiwan and seven strains obtained abroad. Twenty-one RAPD types were revealed using the RAPD fingerprinting method. An RAPD with primer 6032 yielded a polymorphism in a 350 bp fragment that differentiated the attenuated vaccine strain Salm. typhi Ty21a from the rest of the Salm. typhi strains. Strains of Salm. typhi were divided into five types with primer D14307. Primer D14307 also proved capable of discrimination among 65 other Salmonella isolates representing 42 different serotypes. The bacterial DNA used in this RAPD protocol was obtained using a commercially available DNA extraction kit (GeneReleaser). The DNA of various strains of Salmonella from this simple extraction procedure could be discriminated within a few hours using the RAPD technique.

Lipopolysaccharide enhances neurogenic plasma exudation in guinea-pig airways

1. Lipopolysaccharide (LPS) is implicated in many pulmonary and airway inflammatory diseases. Tachykinins released from nerve endings increase vascular permeability. In this study, we have assessed the enhancement by LPS of tachykinin-mediated plasma exudation in guinea-pig airways, and examined the role of oxidants as well as leukocyte adherence. 2. LPS (100 microg kg(-1), i.v.) was administered 0-3 h before bilateral electrical stimulation of the cervical vagus nerves in animals anaesthetized with urethane and ventilated. Vagal stimulation increased vascular permeability in the airways. LPS enhanced the vagally-mediated plasma exudation with the peak effect at 1 h after LPS administration. LPS alone induced no significant plasma exudation. LPS also enhanced exogenous substance P (10(-8) mol kg(-1), i.v.)-induced plasma exudation. 3. The NK-1 receptor antagonist L-732,138 abolished vagally-induced plasma exudation and significantly inhibited the enhancement by LPS. Pretreatment with superoxide dismutase (SOD, 5000 U kg(-1), i.p.) did not affect the vagally-induced plasma exudation, but inhibited the LPS-enhanced neurogenic plasma leakage. The LPS-enhanced vagally-induced plasma exudation was not completely inhibited by either L-732,138 or SOD pretreatment alone, but was blocked by the combination of both pretreatments. 4. Neutrophil depletion by cyclophosphamide alone did not influence vagally-induced plasma exudation, but significantly inhibited the LPS-enhanced response. 5. In conclusion, we have demonstrated LPS enhanced neurogenic plasma exudation by augmenting the response to tachykinins, partly through NK-1 receptors, to directly increase vascular permeability or to enhance leukocyte adhesion-mediated endothelial cell injury. Tachykinins released from nerve endings may contribute to endotoxin-related airway inflammatory responses.

Comparison of once daily cefpodoxime proxetil suspension and thrice daily cefaclor suspension in the treatment of acute otitis media in children

An open-labeled and randomized trial was conducted to compare the efficacy and safety of once daily cefpodoxime proxetil suspension (10mg/kg/day) and thrice daily cefaclor (45mg/kg/day) in the treatment of acute otitis media in children. A total of 57 children aged from 6 months to 9 years were enrolled; 23 were treated with cefpodoxime and 34 with cefaclor. Satisfactory clinical outcome, either cure or improvement, was achieved at the end of treatment in 90% of patients in the cefaclor group and 95% of patients in the cefpodoxime group (p > 0.05). Clinical recurrence was identified at the follow-up visits in one case of the cefaclor group (3%), and none in the cefpodoxime group (p > 0.05). These drugs were well tolerated by 14/21 (67%) in the cefpodoxime-treated group and 27/32 (84%) in the cefaclor-treated group. The incidence of adverse events was slightly higher in the cefpodoxime group than in the cefaclor group, however the difference did not reach statistical significance (p > 0.05). The daily cost of once-daily cefpodoxime was lower than that of thrice-daily cefaclor. We conclude that cefpodoxime administered once daily is as effective and safe as cefaclor administered thrice daily in the treatment of acute otitis media in children. The less dosing frequency and lower daily price of cefpodoxime provide additional benefits.

Effect of erythromycin on feeding intolerance in very low birth weight infants: a preliminary observation

To investigate the effect of erythromycin on feeding intolerance in very low birth weight infants, from February 1997 to December 1997 twenty infants weighing less than 1500 g, with prolonged intolerance of enteral feeding, were enrolled in this study. The protocol for erythromycin treatment was: a loading dose of 30 mg/kg/day, divided into three portions given every eight hours intravenously for 1 hour over a three day period; then a maintenance dose of 3-5 mg/kg intravenously for one hour once a day was given until full feeding was well established. The assessment of erythromycin effect was the daily net orogastric balance (volume of orogastric tube feeding minus volume of orogastric aspirates). The mean gestational age was 27.1 +/- 2.0 weeks (mean +/- SD) and the mean birth weight was 1025 +/- 196 g. The mean age when erythromycin started was 19.5 +/- 14 days; the mean days after the initiation of erythromycin when orogastric tube feeding could be started and full feeding established were 2.4 +/- 1.1 days and 15.1 +/- 2.2 days, respectively. At the beginning of erythromycin treatment, the net balance of tube aspirates was -4.8 +/- 4.1 ml. The net balance rose significantly to 30.6 +/- 15.3 ml, 92.6 +/- 25.4 ml and 125.3 +/- 18.1 ml at 7, 14 and 21 days after erythromycin treatment, respectively. In conclusion, erythromycin treatment is a safe method to improve intolerance of enteral feeding in very low birth weight infants. It is suggested that the effect of erythromycin on gastrointestinal motility in these infants should be further investigated in the context of a randomized, controlled trial before widespread clinical implementation of this treatment.

Portal hypotensive effects of DL-028 and prazosin on portal hypertensive rats

The portal hypotensive effects of prazosin and DL-028 (chem- ical name: 3-[[4-(2-methoxyphenyl)piperazin-1-yl]methyl]- 2, 3-dihydroimidazo[1,2-c]quinazolin-5(6H)-one(27b)), a synthetic alpha1-adrenoceptor antagonist, were assessed in portal hypertensive rats. Portal hypertension was induced by partial portal vein ligation in Sprague-Dawley rats. Two weeks after ligation, when the hyperdynamic state was stabilized the rats were anesthetized after an overnight fast and cannulated for measuring mean arterial pressure (MAP), portal venous pressure (PVP), cardiac index (CI) and heart rate (HR). Both DL-028 and prazosin (1, 3.3 and 10 microgram/kg) induced dose-dependent decreases of PVP and MAP after intravenous infusion, with effects lasting for longer than 30 min. The maximum percentage reduction of PVP after DL-028 was 10, 10 and 15%, respectively, for the dosages given (1, 3.3 and 10 microgram/kg), and 5, 12 and 25%, respectively, after prazosin. CI was not changed by either drug. HR was not changed by either drug except DL-028 at 10.0 microgram/kg with a bradycardiac effect. Our results showed that both DL-028 and prazosin reduced PVP in portal hypertensive rats.

Haemodynamic effects of 8-day octreotide and prazosin administration in portal hypertensive rats

BACKGROUND

Octreotide and prazosin are both effective portal hypotensive drugs in the control or prevention of variceal bleeding. The present study was undertaken to investigate the haemodynamic effects of octreotide and prazosin, alone or in combination, in portal hypertensive rats.

METHODS

Portal hypertension was induced by partial portal vein ligation. Portal hypertensive rats were allocated into one of the four groups-vehicle group (saline, 0.5 mL 12 h-1), octreotide group (30 micrograms kg-1 12 h-1), prazosin group (0.4 mg kg-1 12 h-1), and octreotide (30 micrograms kg-1 12 h-1) plus prazosin (0.4 mg kg-1 12 h-1) group-with eight rats in each group. Prazosin or saline was administered by gavage, whereas octreotide was administered by subcutaneous injection. The drug was given on the day of ligation and continued for 8 consecutive days. Systemic as well as splanchnic haemodynamic parameters were measured thereafter.

RESULTS

Portal vein-ligated rats exhibited typical hyperdynamic state compared with sham-operated rats. The portal venous pressure, portal tributary blood flow and cardiac index were significantly reduced by treatment of octreotide, prazosin or octreotide plus prazosin in portal hypertensive rats. Hyperdynamic parameters of systemic, renal and portal territory vascular resistances, and renal as well as hepatic arterial blood flow were ameliorated by treatment of octreotide or octreotide plus prazosin in portal hypertensive rats. Overall, octreotide treatment exerted more beneficial haemodynamic effects than prazosin treatment. The combination of octreotide and prazosin exerted better haemodynamic effects in cardiac index but worse effects in systemic as well as portal territory vascular resistance than octreotide treatment alone.

Intracranial arachnoid cysts in children: related signs and associated anomalies

Intracranial arachnoid cysts are benign development anomalies that may be clinically asymptomatic. The authors describe 30 children with intracranial arachnoid cysts in terms of clinical manifestations and relations to the associated brain anomalies or lesions. The mean age at onset of clinical manifestations was 4 years, 7 months (range 1 day to 14 years). The mean age at diagnosis was 6 years, 2 months (range 10 days to 16 years). Most patients with nonprogressive symptoms, such as seizures and headache, had focal epileptiform discharges on electroencephalogram, and they benefited from antiepileptic drugs. Surgery resulted in only partial reduction in both cyst size and seizure frequency in patients with intractable seizures, and it also failed to improve some neurologic signs, such as sexual precocity or cranial neuropathy resulting from long-term compression of arachnoid cysts. We conclude that the only absolute indication for surgery is the presence of progressive hydrocephalus or intracranial hypertension. The associated anomalies or lesions include brain tumors, giant nevocellular nevi, achondroplasia, microphthalmia, intracystic hemorrhage, dysgenesis of the corpus callosum, and heterotopia.

Increased level of exhaled nitric oxide and up-regulation of inducible nitric oxide synthase in patients with primary lung cancer

Monocyte-macrophage series have an important role in host surveillance against cancer. The cytotoxic/cytostatic activity of macrophages is, to a great extent, attributed to the up-regulation of inducible nitric oxide synthase (iNOS) and production of nitric oxide (NO). Here, in 28 patients with primary lung cancer and 20 control subjects, we measured the concentration of exhaled NO and nitrite in epithelial lining fluid (ELF) using a chemiluminescence NO analyser, and studied NOS expression in alveolar macrophages (AM) and lung tissues by flow cytometry; immunohistochemical analysis was also undertaken. The mean fluorescence intensity (FI) of iNOS expression in AM was significantly increased in patients with lung cancer (tumour side 263.5 +/- 15.2 FI, normal side 232.4 +/- 18.6 FI; n = 28) compared with that in control subjects (27.3 +/- 3.2 FI; n = 20, P< 0.001). The level of exhaled NO from cancer patients (16.9 +/- 0.9 p.p.b.; n = 28) was significantly higher than that in the control group (6.0 +/- 0.5 p.p.b.; n = 20, P < 0.001). The level of nitrite was also significantly higher in ELF from cancer patients (tumour side 271.1 +/- 28.9 nM and normal side 257.4 +/- 19.6 nM vs control subjects 32.9 +/- 4.1 nM; P< 0.001). The intensity of iNOS expression in AM was correlated with the level of exhaled NO (rs = 0.73, n = 76, P< 0.001) and the nitrite released in ELF (rs = 0.56, n = 76, P< 0.001). The nitrite generation of cultured AM from patients with lung cancer was significantly enhanced compared with that of control subjects after culture for 24 h (tumour side 5.75 +/- 0.69 and normal side 5.68 +/- 0.58 microM per 106 cells vs control group 38.3 +/- 3.6 nM per 106 cells; P< 0.001). The distribution of iNOS was identified in AM, tumour-associated macrophages, endothelium, chondrocytes, airway epithelium of both lungs and malignant cells (adenocarcinoma and alveolar cell carcinoma) of cancer patients. cNOS was labelled in alveolar macrophages, endothelial cells and nerve elements from lung tissue. Our results indicate that, in patients with primary lung cancer, the production of NO from alveolar macrophages was increased as a result of the up-regulation of iNOS activity. The increased NO production was not specific to the tumour side and might be attributed to the tumour-associated non-specific immunological and inflammatory processes of the host.

Ventral abdominal approach for laparoscopic ovariectomy in llamas

OBJECTIVE

To evaluate a technique for laparoscopic ovariectomy by a ventral abdominal approach in the llama.

STUDY DESIGN

Prospective evaluation.

ANIMAL POPULATION

Six healthy adult female llamas, aged 2 to 6 years.

METHODS

Laparoscopic ovariectomy was performed with the llamas in a 30-degree Trendelenburg position. The mesovarium and proper ligament of the ovary were isolated, and two Hulka clips were placed in opposite directions across each mesovarium and proper ligament of the ovary. Ovaries were removed through either the instrument cannula or instrument portal.

RESULTS

The ovaries, mesovarium, and proper ligaments of the ovaries were easily identified using laparoscopy by a ventral abdominal approach. The Hulka Clip Applicator was easy to use, and the Hulka Clips provided secure hemostasis of the vessels within the mesovarium. Mean duration of surgery was 35 minutes (range, 17 to 85 minutes). Two llamas were depressed after surgery but improved within 24 hours. No other complications occurred during an 18-month follow-up period.

CONCLUSIONS

Laparoscopic ovariectomy in the llama was facilitated by the use of Hulka Clips placed across the mesovarium and proper ligament of the ovary.

CLINICAL RELEVANCE

Laparoscopic ovariectomy in the llama can be accomplished easily with few complications.

Transplantation for adrenoleukodystrophy with HLA-A and B nonidentical paternal marrow: report of one case

We report the result of allogeneic bone marrow transplantation (BMT) in a 14-year-old boy who was neurologically severely involved with the childhood form of adrenoleukodystrophy (ALD) and received marrow from his HLA-A and B nonidentical, MLC-nonreactive paternal donor without T-cell depletion processing. Bone marrow transplantation corrected the excess content of very long chain fatty acid in plasma but did not arrest the deterioration of the neurological status during 3.5-year post-transplant follow-up period. Since partially matched or unrelated donors have been applied to clinical BMT successfully with current new techniques, ALD patients will have a better prognosis when they are transplanted in status of mild and early involvement. Our first experience may be helpful in more trials of BMT for genetic leukodystrophy in Taiwan.

Activation of human T-cell leukemia virus type 1 tax gene expression in chronically infected T cells

Expression of human T-cell leukemia virus type 1 (HTLV-1) is regulated both by the HTLV-1 Tax transactivator and by cellular transcriptional factors binding to the viral long terminal repeat (LTR), suggesting that cellular signals may play a role in regulating viral expression. Treatment of cells chronically infected with HTLV-1, which express low levels of HTLV-1 RNAs and Tax protein, with phorbol esters (i.e., phorbol12-myristate 13- acetate [PMA]), phytohemagglutinin (PHA), sodium butyrate, or combinations of cytokines resulted in induction of HTLV- 1 gene expression. PMA or PHA treatment following cotransfection of HTLV-1 Tax expression plasmids resulted in synergistic activation of HTLV-1 LTR-directed gene expression, apparently involving tyrosine ki- nase- mediated pathways. These results suggest that cellular activation stimuli may cooperate with HTLV-1 Tax to enhance expression of integrated HTLV-1 genomes and thus may play a role in the pathogenesis of HTLV-1 disease.

Strokes in children: a medical center-based study

Stroke is an important cause of mortality and morbidity in children. Cases of pediatric stroke admitted to National Taiwan University Hospital from January 1985 to December 1995 were reviewed. Patients whose stroke was obviously caused by premature birth, birth trauma or head injury were excluded. Totally 65 patients were enrolled, including 37 boys and 28 girls. Their ages ranged from birth to 18 years old. They were classified into two groups: ischemic stroke (38 patients) and hemorrhagic stroke (27 patients), according to the pathogenesis. The ages of onset, clinical manifestation, underlying diseases and treatment of these two groups were systematically analyzed. The major presenting symptoms of both ischemic and hemorrhagic strokes were motor deficit (65.8%) and consciousness disturbance (55.6%). A wide variety of diseases predisposing to strokes was identified. The major causes of hemorrhagic stroke were vascular malformation and oncologic conditions, with the latter, the most frequently encountered underlying diseases associated with childhood ischemic stroke. The mortality rate for hemorrhagic stroke was 37% and, for ischemic stroke, 21.1%. There was male predominance in pediatric stroke. Although the clinical symptoms and signs might provide some guidelines to differentiate between hemorrhagic and ischemic strokes, neuroimaging studies were crucial to more exact diagnosis. A variety of diseases may contribute to pediatric stroke. Early diagnosis determine treatability, then aggressive treatment are important.

Ca2+ uptake and Cd2+ accumulation in larval tilapia (Oreochromis mossambicus) acclimated to waterborne Cd2+

The present study compares the rates of Ca2+ uptake and Cd2+ accumulation in tilapia (Oreochromis mossambicus) between larvae preexposed to Cd2+ and naive larvae. Preexposure to Cd2+ induces some form of adaptation that attenuates the effects of Cd2+ later on. Exposure to Cd2+ decreased the uptake of Ca2+ but did not suppress the accumulation rate of Cd2+. A 12-fold increase in 96-h half-maximal lethal concentration was found in tilapia larvae preexposed to 0.45 microM Cd2+ from hatching for 3 days in comparison with naive 3-day-old larvae. The effects of Cd2+ on Ca2+ influx kinetics in larvae preexposed to 0.18 microM Cd2+ for 3 days were examined. The Michaelis constant for Ca2+ in the 0.18 microM Cd2+ preexposed larvae did not change significantly in the presence of Cd2+, whereas maximal velocity increased by approximately 23%. An enhanced Ca2+ uptake efficiency ( approximately 18%) was found in these Cd2+-acclimated larvae. The criterion that determines the survival of tilapia larvae encountering Cd2+ challenge is the degree of interference with Ca2+ homeostasis instead of the absolute amount of Cd2+ accumulated.

Case report: successful obliteration of a bleeding duodenal varix using endoscopic ligation

The occurrence of duodenal varices is rare and experience in the control of haemorrhage from duodenal varices is limited. A 69-year-old man with hepatocellular carcinoma presenting with upper gastrointestinal bleeding is reported. Emergency upper gastrointestinal endoscopy indicated one varix 1.5 cm in diameter with white nipple sign at the anterior wall of the duodenal bulb. Endosonography confirmed the diagnosis of duodenal varix. The patient was treated with endoscopic ligation and follow-up endoscopy showed complete eradication of duodenal varix 3 weeks later.

The effect of ciprofloxacin in the prevention of bacterial infection in patients with cirrhosis after upper gastrointestinal bleeding

OBJECTIVES

Cirrhotic patients with upper gastrointestinal bleeding are prone to bacterial infection. The aim of this study was to investigate the efficacy of prophylactic intestinal decontamination with oral ciprofloxacin for the prevention of bacterial infections in cirrhotic patients with upper gastrointestinal bleeding.

METHODS

A total of 120 cirrhotic patients with acute upper gastrointestinal bleeding were enrolled. Sixty patients received ciprofloxacin 500 mg twice daily given orally or through nasogastric tube immediately after upper gastrointestinal endoscopic examination; drug administration continued for 7 days. The remaining 60 patients, who received placebo, served as controls.

RESULTS

The incidence of proven bacterial infection in the ciprofloxacin-treated group was significantly lower than that of placebo group (10% vs 45%, p < 0.001). The incidences of bacteremia, spontaneous bacterial peritonitis, and urinary tract infection in the ciprofloxacin-treated group were significantly lower than those in the placebo group (0% vs 23%, 3.3% vs 13%, and 5% vs 18%, respectively; p < 0.05, respectively). Multivariate logistic regression analysis showed that a lack of prophylactic treatment with ciprofloxacin and severity of cirrhosis were the independent significant predictors for cirrhotic patients with acute gastrointestinal bleeding with infection.

CONCLUSIONS

Prophylactic intestinal decontamination with oral ciprofloxacin is effective in the prevention of bacterial infections in patients with cirrhosis who were suffering from acute upper gastrointestinal hemorrhage.

Vascular hyporeactivity persists despite increased contractility after long-term administration of isosorbide dinitrate in portal hypertensive rats

BACKGROUND/AIMS

Portal hypertension is associated with decreased vascular responsiveness to vasoconstrictors, which may contribute to the hyperdynamics. Isosorbide dinitrate is an effective portal hypotensive drug. The present study aimed to investigate whether chronic administration of isosorbide dinitrate could affect vascular responsiveness in portal hypertensive rats.

METHODS

Portal hypertension was induced by partial portal vein ligation. Sham-operated (Sham) rats served as controls. There were four animal groups for this study: portal vein ligation-isosorbide dinitrate group, portal vein ligation-vehicle (Veh) group, Sham-isosorbide dinitrate group and Sham-Veh group. Isosorbide dinitrate (5 mg x kg(-1) x 12 h(-1) was given by gavage for 8 days starting 1 day before ligation and continuing thereafter. Mesenteric arteries were removed for contractile study after hemodynamic measurement.

RESULTS

Contractile responses to KCI (15-90 mM) and phenylephrine (10(-9)-10(-4) M) were recorded. Both vascular reactivity and sensitivity were significantly reduced in portal vein ligation rats as compared to Sham rats. Chronic isosorbide dinitrate treatment reduced portal venous pressure in portal vein ligation rats. Moreover, the maximal contractile responses to KCl and phenylephrine were significantly enhanced in both portal vein ligation and Sham rats after isosorbide dinitrate treatment, but relative hyporeactivity persisted in portal vein ligation rats. In contrast, a single dose of isosorbide dinitrate did not alter the contractile sensitivity or reactivity to KCl or phenylephrine in either portal vein ligation or Sham rats.

CONCLUSION

Our results show that long-term administration of isosorbide dinitrate enhanced vascular contractility in both portal vein ligation and Sham rats, but relative hyporeactivity persisted in portal vein ligation rats.

Can advanced hemostatic parameters detect disseminated intravascular coagulation more accurately in patients with cirrhosis of the liver?

BACKGROUND

Laboratory diagnosis of disseminated intravascular coagulation (DIC) is difficult in patients with cirrhosis of the liver due to the complicated hemostatic changes of DIC. More recently, newer molecular hemostatic markers have been used to improve the diagnosis of DIC. This study evaluated the ability of the more advanced hemostatic tests to diagnose DIC in patients with cirrhosis of the liver.

METHODS

A series of hemostatic tests and parameters including activated partial thromboplastin time (APTT), prothrombin time (PT), thrombin time (TT), factor VIII assay, antithrombin (AT) activity, fibrinogen, plasminogen, protamine sulfate test (PST), fibrin (ogen) degradation product (FDP), D-dimer, thrombin-antithrombin complex (TAT) (measured by modified antithrombin, ATM), euglobulin lysis test (ELT) and platelet count were performed in 51 patients with cirrhosis of the liver. A diagnosis of DIC was made according to the following parameters and criteria: a) platelets less than 80 x 10(9)/l; b) PT greater than 1.5, c) APTT greater than 1.3; d) TT greater than 24 sec; e) AT less than 60%; f) ATM greater than 14.7 ng/ml (normal, mean +/- 3 SD); g) fibrinogen less than 1.50 g/l; h) positive PST; i) D-dimer greater than 1.0 microgram/ml; j) FDP greater than 20 micrograms/ml; k) ELT less than 150 min; l) plasminogen less than 50%. DIC was diagnosed if six or more of the above items were present, and at least two of them were item (a) to (h), and at least two were item (g) to (l).

RESULTS

Although eight patients had results that fitted the diagnostic criteria of DIC by using the more advanced tests, only two of them were diagnosed with DIC by conventional testing. The concentration of factor VIII in these eight patients did not markedly decrease.

CONCLUSIONS

New tests are not necessary to improve the diagnosis of DIC in patients with cirrhosis of the liver.

Effect of long-term octreotide and isosorbide dinitrate on haemodynamics in rats with portal vein stenosis

1. Both octreotide and isosorbide dinitrate have been shown to have portal hypotensive effects in animals with portal hypertension. Moreover, in both animals and humans with portal hypertension, the reduction of portal pressure was enhanced when nitrovasodilators were combined with propranolol or vasopressin. The present study was undertaken to evaluate the effect of long-term administration of octreotide and isosorbide dinitrate on haemodynamics in rats with portal vein stenosis. 2. Portal hypertension was induced by portal vein stenosis. Portal hypertensive rats were allocated into one of four groups (eight rats in each group): vehicle group, octreotide group (100 micrograms/kg via subcutaneous injection every 12 h), isosorbide dinitrate group (5 mg/kg via gastric gavage every 12 h) and combined treatment group. Drug was given for eight consecutive days, starting 1 day before surgery. Haemodynamic values were measured using a radioactive microsphere technique. 3. Long-term octreotide treatment decreased portal pressure and improved the hyperdynamic circulation. In contrast, long-term administration of isosorbide dinitrate reduced portal pressure but did not ameliorate vasodilatation. A combination of octreotide and isosorbide dinitrate improved the hyperdynamic circulation with a reduction of portal pressure. In addition, the mean value of portal pressure after combination treatment was significantly lower than in rats receiving octreotide alone. 4. These results showed that, in rats with portal hypertension, long-term combined administration of octreotide and isosorbide dinitrate improved the hyperdynamic circulation together with a more profound reduction of portal pressure than rats receiving octreotide alone.

Early dexamethasone therapy in preterm infants: a follow-up study

OBJECTIVES

To study the outcome at 2-year corrected age of infants who participated in a double-blind controlled trial of early (<12 hours) dexamethasone therapy for the prevention of chronic lung disease (CLD).

METHODS AND MATERIALS

A total of 133 children (70 in the control group, 63 in the dexamethasone-treated group) who survived the initial study period and lived to 2 years of age were studied. All infants had birth weights of 500 to 1999 g and had severe respiratory distress syndrome requiring mechanical ventilation within 6 hours after birth. For infants in the treatment group, dexamethasone was started at a mean age of 8.1 hours and given 0.25 mg/kg every 12 hours for 1 week and then tapered off gradually over a 3-week period. The following variables were evaluated: interim medical history, socioeconomic background, physical growth, neurologic examinations, mental and psychomotor development index score (MDI and PDI), pulmonary function, electroencephalogram, and auditory and visual evoked potential.

RESULTS

Infants in the control group tended to have a higher incidence of upper respiratory infection and rehospitalization than did the dexamethasone-treated group because of respiratory problems. Although there was no difference between the groups in somatic growth in girls, the dexamethasone-treated boys had significantly lower body weight and shorter height than the control boys (10.7 +/- 3.0 vs 11.9 +/- 2.0 kg; 84.9 +/- 5.7 vs 87.5 +/- 4.8 cm). The dexamethasone-treated group had a significantly higher incidence of neuromotor dysfunction (25/63 vs 12/70) than did the control group. The dexamethasone-treated infants also had a lower PDI score (79 +/- 26) than did the control group (87 +/- 23), but the difference was not statistically significant. Both groups were comparable in MDI, incidence of vision impairment, and auditory and visual evoked potential. Significant handicap, defined as severe neurologic defect and/or intellectual defect (MDI and/or PDI </= 69), was seen in 22 children (31.4%) in the control group and 26 (41.2%) in the dexamethasone-treated group.

CONCLUSIONS

Although early postnatal dexamethasone therapy for 4 weeks significantly reduces the incidence of CLD, this therapeutic regimen cannot be recommended at present because of its adverse effects on neuromotor function and somatic growth in male infants, detected at 2 years of age. A longer follow-up is needed. If early dexamethasone therapy is to be used for the prevention of CLD, the therapeutic regimen should be modified. The proper route of administration, the critical time to initiate the therapy, and the dosage and duration of therapy remain to be defined further.

Sequestration of the G protein beta gamma subunit complex inhibits receptor-mediated endocytosis

Cell surface receptors that mediate endocytosis cluster into clathrin-coated pits, which pinch off to form vesicles that transport the receptors and their ligands. This multi-step process requires the coordinated action of many factors, including GTP-hydrolyzing proteins such as dynamin and regulators of actin cytoskeleton assembly. We note herein that sequestration of heterotrimeric G protein beta gamma subunits in intact cells strongly inhibits clathrin-coated pit-mediated endocytosis and causes rearrangement of the actin cytoskeleton. Our results suggest that cells contain a pool of free beta gamma and that it functions constitutively to permit endocytosis.

Increased exhaled nitric oxide in active pulmonary tuberculosis due to inducible NO synthase upregulation in alveolar macrophages

Nitric oxide (NO) plays an important role in resistance to Mycobacterium tuberculosis infection. Our aim was to determine whether inducible NO synthase (iNOS) expression and generation of reactive nitrogen intermediates (RNI) by alveolar macrophages (AM) are increased in patients infected with M. tuberculosis. NO levels in the exhaled air of 19 active pulmonary tuberculosis (TB) and 14 control subjects were measured using a chemiluminescence NO analyser. The expression of iNOS on AM was studied by labelling AM with anti-mac iNOS polyclonal antibody analysed with a flow cytometer. The spontaneous generation of RNI by cultured AM was also measured. Data are presented as mean+/-SEM. The level of NO in exhaled air was higher in patients with active TB (16.2+/-1.2 parts per billion (ppb)) compared to control subjects (6.5+/-0.9 ppb), p<0.0001. Exhaled NO decreased with anti-TB treatment. Compared to control subjects (29.0+/-4.5 fluorescence intensity (FI)), iNOS expression on AM was upregulated in TB patients (86.3+/-12.5 FI) p<0.001 and the capacity for spontaneous generation of nitrite was enhanced. Nitrite production was inhibited by N(G)-monomethyl-L-arginine (L-NMMA), a competitive inhibitor of iNOS. The expression of iNOS on AM was related to the concentration of exhaled NO (r=0.66, p<0.001) and the nitrite generation capacity of AM (r(s)=0.77, p<0.001). We conclude that the increase in exhaled nitric oxide observed in patients with active pulmonary tuberculosis is due to an upregulation of inhaled NO synthase expression in alveolar macrophages which have an enhanced capacity for nitric oxide production.

Chronic administration of octreotide ameliorates portal hypertension and portal hypertensive gastropathy in rats with cirrhosis

1. Portal hypertension and hyperdynamic circulation have been postulated to play a role in the pathogenesis of portal hypertensive gastropathy. Administration of octreotide to portal hypertensive rats has been shown to reduce portal pressure and ameliorate hyperdynamic circulation. 2. This study investigated the effects of chronic administration of octreotide on systemic and portal haemodynamics and the development of portal hypertensive gastropathy in carbon tetrachloride-induced cirrhotic rats. 3. After 12 weeks of carbon tetrachloride induction, cirrhotic rats were randomly assigned to receive either placebo (5% dextrose in water) or octreotide (65 micrograms/kg in 5% dextrose in water) subcutaneously twice daily for 10 days. Haemodynamic studies with a thermodilution technique and gastric morphometric analyses were performed at 10 days after treatment. 4. In cirrhotic rats, octreotide treatment induced a significant increase in systemic vascular resistance (2.7 +/- 0.2 versus 3.4 +/- 0.2 mmHg/ml.min-1.100 g-1, P < 0.05) and decrease in portal pressure (12.5 +/- 1.2 versus 9.9 +/- 0.5 mmHg, P < 0.05) compared with placebo-treated rats. In addition, octreotide treatment significantly reduced the mean cross-sectional area of gastric mucosal vessels (2290 +/- 145 versus 1810 +/- 101 micron 2, P < 0.05). 5. This study shows that chronic octreotide treatment ameliorates the development of portal hypertensive gastropathy in cirrhotic rats. The effect of octreotide on portal hypertensive gastropathy may, at least partly, be due to the alleviation of portal hypertension and hyperdynamic circulation.

Stereochemistry and biological activities of constituents from Cynanchum taiwanianum

The stereochemistry of new acetophenones, cynandione B-D (2-4), isolated from Cynanchum taiwanianum, elucidated by computer modelling calculation and NOESY spectrum. It establishes the absolute configurations of cynandiones B-D (2-4) as 7R; 7"S, 7S; 7"S and 7R; 7"R, respectively. Cynandione B (2) strongly inhibited the release of beta-glucuronidase and lysozyme in formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated rat neutrophils in a concentration-dependent manner with IC50 values of 1.5 +/- 0.2 and 1.6 +/- 0.2 microM, respectively. 2,5-Dihydroxyacetophenone (6) strongly inhibited the aggregation of washed rabbit platelets induced by arachidonic acid in a concentration-dependent manner with an IC50 value of about 4.8 microM. In human citrated platelet-rich plasma, 2,5-dihydroxyacetophenone (6) inhibited the secondary phase, but not the primary phase, of aggregation induced by adrenaline and ADP. These results suggest that the antiplatelet effect of 2,5-dihydroxyacetophenone (6) is due to inhibition of the formation of thromboxane A2.

Two novel compounds from Paeonia suffructicosa

A new hexacyclic triterpenoid, mudanpinoic acid A (1), and a new gallic acid glycoside, mudanoside B (2), along with nine known compounds--benzoic acid, resacetophenone, paeoniflorigenone, beta-sitosterol, betulinic acid, oleanoic acid, quercetin, beta-sitosterol-beta-D-glucoside, and trans-caffeic acid stearyl ester-were isolated from the dried root cortex of Paeonia suffruticosa. The structures of the novel compounds were elucidated on the basis of spectral methods, and that of compound 1 was confirmed by X-ray crystallographic analysis.

Haemodynamic effects of chronic octreotide and tetrandrine administration in portal hypertensive rats

Octreotide is an effective portal hypotensive drug in the control of variceal bleeding. Tetrandrine is a type of calcium channel blocker recently reported to reduce portal hypertension. The present study was undertaken to investigate the haemodynamic effects of octreotide and tetrandrine, alone and in combination, in portal hypertensive rats. Portal hypertension was induced by partial portal vein ligation. Portal hypertensive rats were allocated into one of the four groups: vehicle group (saline, 0.5 mL/day), octreotide group (100 microg/kg per 12 h), tetrandrine group (20 mg/kg per 12 h), and octreotide (100 microg/kg per 12 h) plus tetrandrine (20mg/kg per 12 h) group. Tetrandrine or saline was administered by gavage, and octreotide by subcutaneous injection. The drug was given for 8 consecutive days, starting 1 day before ligation and continuing onwards. Haemodynamic parameters were measured thereafter, using the radioactive microsphere method. The portal venous pressure and portal tributary blood flow were significantly reduced, while portal territory and renal vascular resistances were significantly enhanced, by octreotide, tetrandrine, or octreotide plus tetrandrine in portal hypertensive rats, compared with the vehicle group. Our results showed that long-term administration of octreotide, tetrandrine, or octreotide plus tetrandrine led to portal hypotensive effects in portal hypertensive rats, but octreotide alone exerted better anti-hyperdynamic effects compared with tetrandrine alone. A combination of octreotide and tetrandrine offered no major beneficial anti-hyperdynamic effects compared with octreotide alone.

Effect of sucralfate granules in suspension on endoscopic variceal sclerotherapy induced ulcer: analysis of the factors determining ulcer healing

Oesophageal ulcers commonly occur after endoscopic variceal sclerotherapy and usually cause complications and a delay in further sclerotherapy. The aims of this study are to investigate the effect of sucralfate granules in suspension on the treatment of endoscopic variceal sclerotherapy induced ulcer and analyse the factors determining the ulcer healing. Fifty-two patients with oesophageal variceal bleeding received elective endoscopic variceal sclerotherapy. After endoscopically proved oesophageal ulcers, they were randomized to receive either sucralfate granules in suspension (n = 22) or antacid (n = 23). Follow-up endoscopy was performed weekly. Ulcer healing rates were compared between the groups using the log-rank test. Forty-one ulcers receiving sucralfate and 48 ulcers receiving antacid treatment were evaluated. The clinical characteristics of the ulcers were similar in both groups. The ulcers in patients receiving sucralfate healed faster than those receiving antacid (P<0.02). On analysis of factors affecting ulcer healing, ulcers smaller than 1 cm2 (n = 59) appeared to heal faster than those larger than 1 cm2 (n = 30; P= 0.059) and shallow ulcers (n = 46) healed faster than deep ulcers (n = 43; P<0.001). On multifactorial analysis, ulcer depth was the only factor determining ulcer healing. The ulcer healing effects of sucralfate became more prominent when the ulcer was larger than 1.0cm2 (1.7+/-0.6 weeks vs 2.3+/-0.6 weeks, P= 0.011) and deep (1.7+/-0.7 weeks vs 2.5+/-1.0 weeks, P= 0.013) when compared with those receiving antacid. Sucralfate granules in suspension speed the healing of endoscopic variceal sclerotherapy induced ulcer, especially deep and large ulcers.

Hemodynamic effects of eight-day octreotide and propranolol administration in portal hypertensive rats

Octreotide and propranolol are both effective portal hypotensive drugs in the control or prevention of variceal bleeding. The present study was undertaken to investigate the hemodynamic effects of octreotide and propranolol, alone or in combination, in portal hypertensive rats. Portal hypertension was induced by partial portal vein ligation. Portal hypertensive rats were allocated into one of the four groups: vehicle group (saline, 0.5 ml/day), octreotide group (100 microg/kg/12 hr), propranolol group (30 mg/kg/day), and octreotide (100 microg/kg/12 hr) plus propranolol (30 mg/kg/day) group. Propranolol or saline was administered by gavage, octreotide by subcutaneous injection. Drug was given one day before ligation and continued for eight consecutive days. Systemic as well as splanchnic hemodynamic parameters were measured thereafter. The portal venous pressure, portal tributary blood flow, and cardiac index were significantly reduced by octreotide, propranolol, or octreotide plus propranolol in portal hypertensive rats. Portal territory, systemic, and renal vascular resistances were significantly enhanced, while hepatic arterial blood flow significantly reduced, in the octreotide and octreotide plus propranolol groups as compared to vehicle group. Our results showed that eight-day administration of octreotide, propranolol, or octreotide plus propranolol led to portal hypotensive and antihyperdynamic effects in portal hypertensive rats. Overall, octreotide treatment alone resulted in better antihyperdynamic profiles than propranolol treatment alone. The combination of octreotide and propranolol offered no therapeutic benefits and was slightly less effective than octreotide alone.

Evaluation of analgesia induced by epidural administration of medetomidine to cows

OBJECTIVE

To evaluate analgesic effects after epidural administration of medetomidine to cows, compared with effects of lidocaine hydrochloride and 0.9% NaCl solution.

ANIMALS

6 adult beef cows.

PROCEDURE

3 treatments were administered to each cow, with a 1-week interval between subsequent treatments. Treatments consisted of 5 ml of physiologic saline (0.9% NaCl) solution; 0.2 mg of lidocaine/kg of body weight, not to exceed 100 mg (5 ml); and 15 micrograms of medetomidine/kg, diluted with 0.9% NaCl solution to provide a volume of 5 ml. Epidural injections were given in the first or second coccygeal space. Heart rate, respiratory rate, and arterial blood pressure values were recorded before injection, 5 and 10 minutes after injection, and at 10-minute intervals thereafter. Onset and duration of analgesia, sedation, and ataxia were recorded. A repeated-measures ANOVA was used to detect differences between treatments.

RESULTS

Epidural administration of 0.9% NaCl solution did not induce analgesia. Lidocaine induced analgesia within 5 to 20 minutes, which lasted 10 to 115 minutes (mean +/- SD, 43.3 +/- 37.2 minutes). Heart rate decreased during lidocaine-induced analgesia. Heart and respiratory rates decreased, but blood pressure remained unchanged, after medetomidine administration. Medetomidine induced analgesia within 5 to 10 minutes, which lasted 412 +/- 156 minutes. Mild to moderate sedation and moderate ataxia were observed. Two cows became recumbent, but were easily coaxed to stand. Medetomidine-induced salivation and increased frequency of urination were observed in all cows.

CONCLUSIONS AND CLINICAL RELEVANCE

Epidural administration of medetomidine induced prolonged analgesia that was suitable for perineal surgery, postoperative analgesia, and relief of continuous straining.

Advances in nutrition and gastroenterology: summary of the 1997 A.S.P.E.N. Research Workshop

BACKGROUND

The 1997 A.S.P.E.N. Research Workshop was held at the annual meeting in San Francisco, on January 26, 1997. The workshop focused on advances in clinical and basic research involving the interface between nutrient and luminal gastroenterology.

METHODS

Presentations on the genetic regulation of gastrointestinal development, the molecular biology of small intestinal adaptation, the effect of nutrition support on intestinal mucosal mass, the relationship between nutrition and gastrointestinal motility, nutrient absorption, and gastrointestinal tract substrate metabolism were made by the preeminent leaders in the field.

RESULTS

The investigators presented an insightful analysis of each topic by reviewing data from their own laboratories and the published literature.

CONCLUSIONS

This workshop underscored the important interactions between nutrition and luminal gastroenterology at the basic science, metabolic/physiologic, and clinical levels. The integration of presentations from the different disciplines provided a unique interaction of information and ideas to advance our understanding of nutrition and gastrointestinal tract.

Sedative effects of medetomidine and its reversal by atipamezole in llamas

OBJECTIVE

To determine a dose of medetomidine that will induce sedation in llamas, to assess effects of medetomidine sedation on arterial blood gas variables, and to determine efficacy of atipamezole in reversing medetomidine-induced sedation.

DESIGN

Prospective, randomized clinical trial.

ANIMALS

15 clinically normal adult llamas.

PROCEDURE

9 llamas received various doses of medetomidine (0.01, 0.02, or 0.03 mg/kg [0.005, 0.009, or 0.014 mg/lb] of body weight, i.m.). Heart and respiratory rates and sedative effects were recorded. Using the lowest dose that induced deep sedation, 6 different llamas were used to assess effects of medetomidine on arterial blood gas variables. These same 6 llamas were later given atipamezole (0.125 mg/kg [0.057 mg/lb], i.v.) 30 minutes after medetomidine injection. Heart and respiratory rates, sedative effects, and time from atipamezole injection to standing were recorded.

RESULTS

Sedation began 6.67 +/- 1.15 minutes (mean +/- SD) after medetomidine administration (0.03 mg/kg, i.m.). Arterial blood gas variables measured 30 and 60 minutes after injection were not different from baseline. Llamas that did not receive atipamezole remained recumbent for 91.50 +/- 24.68 minutes. After atipamezole administration, llamas were able to stand in 5.80 +/- 3.27 minutes.

CLINICAL IMPLICATIONS

Medetomidine induced light to deep sedation in a dose-dependent manner in clinically normal llamas. A dose of 0.03 mg/kg induced deep sedation with a short period of analgesia. Atipamezole rapidly reversed effects of medetomidine, and llamas recovered quickly and were soon able to stand.

Association of human herpes virus 6 (HHV-6) with multiple sclerosis: increased IgM response to HHV-6 early antigen and detection of serum HHV-6 DNA

Viruses have long been suggested to be involved in the etiology of multiple sclerosis (MS). This suggestion is based on (1) epidemiological evidence of childhood exposure to infectious agents and increase in disease exacerbations with viral infection; (2) geographic association of disease susceptibility with evidence of MS clustering; (3) evidence that migration to and from high-risk areas influences the likelihood of developing MS; (4) abnormal immune responses to a variety of viruses; and (5) analogy with animal models and other human diseases in which viruses can cause diseases with long incubation periods, a relapsing-remitting course, and demyelination. Many of these studies involve the demonstration of increased antibody titers to a particular virus, whereas some describe isolation of virus from MS material. However, no virus to date has been definitively associated with this disease. Recently, human herpesvirus 6 (HHV-6), a newly described beta-herpes virus that shares homology with cytomegalovirus (CMV), has been reported to be present in active MS plaques. In order to extend these observations, we have demonstrated increased IgM serum antibody responses to HHV-6 early antigen (p41/38) in patients with relapsing-remitting MS (RRMS), compared with patients with chronic progressive MS (CPMS), patients with other neurologic disease (OND), patients with other autoimmune disease (OID), and normal controls. Given the ubiquitous nature of this virus and the challenging precedent of correlating antiviral antibodies with disease association, these antibody studies have been supported by the detection of HHV-6 DNA from samples of MS serum as a marker of active viral infection.

Cardiovascular effects of nitric oxide and N-methyl-D-aspartate receptors in the nucleus tractus solitarii of rats

Nitric oxide (NO) is an endogenously synthesized effector molecule that acts as a neurotransmitter with novel properties in both the central and peripheral nervous systems. We previously reported that NO was involved in central cardiovascular regulation and modulated the baroreflex in the nucleus tractus solitarii (NTS) of rats. The aim of the present study was to determine whether NO and excitatory amino acids reciprocally release each other in the NTS. In normotensive Sprague-Dawley rats, intra-NTS microinjection of L-arginine (1 to 100 nmol/60 nL) produced a dose-dependent decrease in blood pressure and heart rate. Microinjection of excitatory amino acids L-glutamate and NMDA also produced depressor and bradycardic effects. These effects of L-glutamate or NMDA were blocked by prior administration of NO synthase inhibitor N(G)-methyl-L-arginine or N(G)-nitro-L-arginine methyl ester. Similarly, prior administration of N-methyl-D-aspartate (NMDA) receptor antagonist MK-801 and non-NMDA receptor antagonist 6,7-dinitroquinoxaline-2,3-dione significantly attenuated the depressor and bradycardic effect of L-arginine. These results demonstrated a reciprocal attenuation of NO synthase inhibitor and NMDA receptor antagonist on NMDA and L-arginine responses, respectively, in the NTS and suggest that NO and NMDA receptors may interact in central cardiovascular regulation.

Intestinal transit and absorption of soy protein in dogs depend on load and degree of protein hydrolysis

Soy protein, in both intact and hydrolyzed forms, is widely used as the nitrogen source in infant and adult formulas. This protein is also consumed in vast quantities worldwide as soybean-based food products. Digestion is the rate-limiting step in the assimilation of proteins from the gut. As a result, intestinal transit must be slowed when a higher load of protein is available or when this nutrient is delivered in the intact rather than hydrolyzed form. However, little information is available on the effect of load and degree of hydrolysis of soy protein on intestinal transit and protein absorption. To test the hypothesis that inhibition of intestinal transit and protein absorption depend on the load of soy protein and the state of hydrolysis of this nutrient, we compared intestinal transit and protein absorption in dogs equipped with duodenal and midintestinal fistulas during intestinal perfusion with 0, 50, 100, or 200 g/L solutions of intact soy protein versus 0, 100, 200, 300, or 400 g/L solutions of hydrolyzed soy protein. We found that intestinal transit was slowed in a load-dependent fashion by intact (P < 0.001) and hydrolyzed (P < 0.05) soy protein. Soy protein inhibited intestinal transit more potently in the intact than hydrolyzed form (P < 0.05). A greater amount of protein was absorbed by the proximal half of the small intestine when soy protein was delivered in the hydrolyzed than intact form (P < 0.05), and the efficiency of protein absorption was maintained at a high and nearly constant level of 82.6 to 87.4% for intact soy protein and 89.0 to 92.3% for hydrolyzed soy protein. We conclude that in dogs intestinal transit and absorption of soy protein depend on the load and the degree of protein hydrolysis.

Comparison of Vibrio cholerae O1 isolates by polymerase chain reaction fingerprinting and ribotyping

The rRNA gene restriction patterns and the polymerase chain reaction (PCR) fingerprinting types of 53 Vibrio cholerae O1 isolates were studied. Five and eight patterns were observed from 27 toxigenic and 26 non-toxigenic O1 isolates after BglI cleavage. PCR fingerprinting with three primer sets aimed at enterobacterial repetitive intergenic consensus (ERIC) sequences, ERIC-related sequences in V. cholerae, another kind of repeated sequences in V. cholerae (VCR) and arbitrary sequences divided the same strains into seven and 10 PCR types, respectively. Eight ribotypes had unique PCR patterns. PCR fingerprinting identified more than one pattern among isolates within each of the remaining ribotypes. However, ribotyping was able to differentiate the same PCR types in one case. A single ribotype and a single PCR pattern were found in toxigenic O1 strains isolated in Taiwan from imported food and imported cases of cholera between 1993 and 1995. Typing of V. cholerae O1 by PCR fingerprinting correlated well with ribotyping, but was more discriminating. PCR assay provides a rapid and simple means of typing these strains for epidemiological studies.

Plasma substance P levels in patients with liver cirrhosis: relationship to systemic and portal hemodynamics

OBJECTIVES

Nitric oxide has been proposed as being responsible for the hyperdynamic circulation observed in portal hypertensive states. Substance P, a neuropeptide partly cleared by liver, induces vasodilation through the activation of the endothelial nitric oxide pathway. This study investigated the plasma levels of substance P in cirrhotic patients and the relationship of these levels to systemic and portal hemodynamics.

METHODS

Sixty-four patients with cirrhosis and 53 healthy controls had blood samples taken for determining plasma values of substance P by ELISA. Systemic and portal hemodynamics were measured on the same day of blood sampling using a Swan-Ganz catheterization and thermodilution technique.

RESULTS

Plasma levels of substance P were higher in cirrhotic patients than in healthy controls (45.7 +/- 2.0 vs 32.9 +/- 1.0 pg/ml, p < 0.001) and directly correlated with Child-Pugh's score (r = 0.52, p < 0.0001). Compared with compensated cirrhotic patients, decompensated cirrhotic patients had higher plasma levels of substance P accompanied by a lower systemic vascular resistance and higher hepatic venous pressure gradient. There was no significant correlation between plasma levels of substance P and systemic vascular resistance and hepatic venous pressure gradient. In addition, no significant difference in plasma levels of substance P was observed between cirrhotic patients with and cirrhotic patients without a hepatic venous pressure gradient > 12 mm Hg or between patients with and patients without large esophageal varices.

CONCLUSIONS

Plasma levels of substance P are increased in patients with cirrhosis and may contribute to the pathogenesis and/or maintenance of hyperdynamic circulation in decompensated patients. The severity of cirrhosis is more important than portal hypertension and the severity of esophageal varices for the development of increased plasma substance P levels.

Phosphatidylinositol (4,5)-bisphosphate-dependent activation of dynamins I and II lacking the proline/arginine-rich domains

Dynamins comprise a family of GTPases that participate in the early stages of endocytosis. The GTPase activity of neuronal specific dynamin I is stimulated by microtubules, negatively charged phospholipid vesicles, and Src homology 3-containing proteins, including Grb2. These activators were previously shown to bind to a proline/arginine-rich domain (PRD) in the carboxyl-terminal region of the enzyme. Dynamin II, which is ubiquitously expressed, had not been purified or characterized previously. In this study, the enzymatic properties of rat dynamin II and of D746, a dynamin II truncation mutant lacking the PRD, have been characterized. Dynamin II has a higher basal activity than dynamin I, but the two types of dynamin are stimulated similarly by microtubules, Grb2, and phospholipids. D746 is not activated by microtubules or Grb2, highlighting the significance of the PRD for these interactions, but it is activated by phospholipid vesicles containing phosphatidylserine or phosphatidylinositol-4,5- bisphosphate. Moreover, in contrast to previous reports, the PRD appears not to be required for phospholipid-stimulated self-assembly of dynamin, which is a key element in the regulation of its activity. Similar results were obtained with bovine brain dynamin I that had been subjected to limited proteolytic digestion to remove the PRD. Our data highlight the potential involvement of dynamin pleckstrin homology domains in the regulation of GTPase activity by phospholipids.

Sequential changes of esophageal motility after endoscopic injection sclerotherapy or variceal ligation for esophageal variceal bleeding: a scintigraphic study

OBJECTIVE

Endoscopic injection sclerotherapy and variceal ligation are two popular endoscopic methods used to treat esophageal variceal hemorrhage. These two methods have not been compared with regard to esophageal dysfunction after treatment. This is a prospective investigation of esophageal dysmotility after endoscopic injection sclerotherapy and variceal ligation.

METHODS

Sequential changes of esophageal motility after endoscopic injection sclerotherapy (n = 25) and variceal ligation (n = 25) were investigated in 50 cirrhotic patients with recent variceal bleeding. Another 22 cirrhotics without esophageal varices were included as controls. Radionuclide esophageal transit tests were performed before initial endoscopic treatment, and 1 and 3 months after variceal eradication.

RESULTS

The baseline esophageal transit time was longer in both the sclerotherapy (n = 25, 7.8 +/- 1.4 s) and ligation groups (n = 25, 8.2 +/- 1.8 s) than in controls (n = 22, 6.7 +/- 0.7 s, p < 0.005). The transit time was longer in patients with large varices than in those with small varices (8.3 +/- 1.7 vs. 7.2 +/- 0.7 s, p < 0.05). In the sclerotherapy group, the transit time was prolonged 1 month after variceal eradication, compared with its pretreatment state (n = 20, 7.6 +/- 1.5 vs. 10.0 +/- 2.2 s, p < 0.0001) but was shortened at 3 months compared with 1 month after variceal eradication (n = 12, 10.7 +/- 1.5 vs. 8.6 +/- 2.2 s, p < 0.05). Multiple regression analysis showed that the number of treatment sessions required to eradicate varices was the only significant factor associated with prolonged transit time (p < 0.05). In the ligation group, the transit time changed little at 1 month or 3 months after variceal eradication.

CONCLUSIONS

Impairment of esophageal motility can be significant with endoscopic injection sclerotherapy but is reversible. However, endoscopic variceal ligation exerts no significant impact on esophageal motility.

Recent advances in the pathophysiology of portal hypertension

Portal hypertension is a common complication of chronic liver disease. Increased resistance to portal blood flow through a cirrhotic liver initiates the development of portal hypertension. In addition, alteration of neural and humoral regulations, endothelins, and stellate cells all contribute to the increased intrahepatic resistance. Moreover, the collateral circulation represents an additional site of increased resistance to portal blood flow. Increased splanchnic blood flow appears to play an important role in the maintenance of chronic portal hypertension. Several mechanisms have been proposed to explain this haemodynamic derangement including increased circulating vasodilators, endothelial-derived vasodilators, and decreased vascular reactivity to vasoconstrictors. Finally, the development of portal hypertension induces peripheral arterial vasodilation. The arterial vasodilatation may result in an increase in vascular underfilling which in turn leads to sodium retention and plasma volume expansion. The increased plasma volume is necessary for the development of increased cardiac output and the full expression of hyperdynamic circulation in portal hypertension.

Hemodynamic effects of acute tetrandrine and terlipressin administration on portal hypertensive rats

The purpose of this study was to investigate the therapeutic effects of tetrandrine and terlipressin, alone or in combination, on anesthetized portal hypertensive rats. Portal hypertension was induced by partial portal vein ligation in Sprague-Dawley rats. Each portal hypertensive rat received one of three regimens: vehicle plus terlipressin, tetrandrine (.50 mg.kg-1.min-1) [corrected] plus terlipressin, or tetrandrine (.75 mg.kg-1.min-1) [corrected] plus terlipressin. Terlipressin dosage was 0.025 mg.kg-1.min-1 [corrected] infused for 3 min. Infusion of vehicle followed by terlipressin induced significant reduction of portal venous pressure (PVP, -24.3 +/- 1.5%) and prominent elevation of mean arterial pressure (MAP, 73.3 +/- 4.6%) as well as total peripheral resistance (TPR, 133 +/- 8%) from baseline, and there was a cardiodepressant response (cardiac index, CI, -30.6 +/- 3.8%; heart rate, HR, -10.4 +/- 2.1%). Infusion of tetrandrine (.50 mg.kg-1.min-1) [corrected] induced significant reduction of PVP (-7.2 +/- 0.9%), MAP (-12.5 +/- 1.6%), and TPR (-14.3 +/- 4.2%) from baseline. Infusions of tetrandrine followed by terlipressin induced significant reduction of PVP (-14.2 +/- 2.4%) but an increase in MAP (22.6 +/- 2.7%) and TPR (71.1 +/- 10.5%). Infusion of tetrandrine (.75 mg.kg-1.min-1) [corrected] induced significant reduction of PVP (-9.9 +/- 0.8%). MAP (-19.2 +/- 2.1%), and TPR (-24.1 +/- 2.1%) from baseline. Infusions of tetrandrine followed by terlipressin induced significant reduction of PVP (-14.0 +/- 1.1%) but an increase in MAP (14.0 +/- 2.7%) and TPR (75.2 +/- 5.2%). Compared with vehicle followed by terlipressin, tetrandrine significantly attenuated systemic pressor (MAP and TPR elevation), cardiodepressant (CI reduction) as well as portal hypotensive (PVP reduction) effects of terlipressin. Our results suggest that tetrandrine and terlipressin, alone or in combination, induced portal hypotensive effects in portal hypertensive rats. Combined tetrandrine and terlipressin administration ameliorated systemic pressor and cardiodepressant effects of terlipressin, but it also attenuated the latter's portal hypotensive effects.

Early postnatal dexamethasone therapy for the prevention of chronic lung disease in preterm infants with respiratory distress syndrome: a multicenter clinical trial

OBJECTIVES

To study whether early postnatal (<12 hours) dexamethasone therapy reduces the incidence of chronic lung disease in preterm infants with respiratory distress syndrome.

MATERIALS AND METHODS

A multicenter randomized, double-blind clinical trial was undertaken on 262 (saline placebo, 130; dexamethasone, 132) preterm infants (<2000 g) who had respiratory distress syndrome and required mechanical ventilation shortly after birth. The sample size was calculated based on the 50% reduction in the incidence of chronic lung disease when early dexamethasone is used, allowing a 5% chance of a type I error and a 10% chance of a type II error. For infants who received dexamethasone, the dosing schedules were: 0.25 mg/kg/dose every 12 hours intravenously on days 1 through 7; 0.12 mg/kg/dose every 12 hours intravenously on days 8 through 14; 0.05 mg/kg/dose every 12 hours intravenously on days 15 through 21; and 0. 02 mg/kg/dose every 12 hours intravenously on days 22 through 28. A standard protocol for respiratory care was followed by the participating hospitals. The protocol emphasized the criteria of initiation and weaning from mechanical ventilation. The diagnosis of chronic lung disease based on oxygen dependence and abnormal chest roentgenogram was made at 28 days of age. To assess the effect of dexamethasone on pulmonary inflammatory response, serial tracheal aspirates were assayed for cell counts, protein, leukotriene B4, and 6-keto prostaglandin F1alpha. All infants were observed for possible side effects, including hypertension, hyperglycemia, sepsis, intraventricular hemorrhage, retinopathy of prematurity, cardiomyopathy, and alterations in calcium homeostasis, protein metabolism, and somatic growth.

RESULTS

Infants in the dexamethasone group had a significantly lower incidence of chronic lung disease than infants in the placebo group either judged at 28 postnatal days (21/132 vs 40/130) or at 36 postconceptional weeks (20/132 vs 37/130). More infants in the dexamethasone group than in the placebo group were extubated during the study. There was no difference between the groups in mortality (39/130 vs 44/132); however, a higher proportion of infants in the dexamethasone group died in the late study period, probably attributable to infection or sepsis. There was no difference between the groups in duration of oxygen therapy and hospitalization. Early postnatal use of dexamethasone was associated with a significant decrease in tracheal aspirate cell counts, protein, leukotriene B4, and 6-keto prostaglandin F1alpha, suggesting a suppression of pulmonary inflammatory response. Significantly more infants in the dexamethasone group than in the placebo group had either bacteremia or clinical sepsis (43/132 vs 27/130). Other immediate, but transient, side effects observed in the dexamethasone group are: an increase in blood glucose and blood pressure, cardiac hypertrophy, hyperparathyroidism, and a transient delay in the rate of growth.

CONCLUSIONS

In preterm infants with severe respiratory distress syndrome requiring assisted ventilation shortly after birth, early postnatal dexamethasone therapy reduces the incidence of chronic lung disease, probably on the basis of decreasing the pulmonary inflammatory process during the early neonatal period. Infection or sepsis is the major side effect that may affect the immediate outcome. Other observable side effects are transient. In view of the significant side effects and the lack of overall improvement in outcome and mortality, and the lack of long term follow-up data, the routine use of early dexamethasone therapy is not yet recommended.

Hemodynamic effects of chronic tetrandrine treatment in Sprague-Dawley rats

Tetrandrine is a calcium channel antagonist with reported anti-hypertensive effect. The present study aimed to investigate the hemodynamic effects of chronic tetrandrine treatment on normotensive Sprague-Dawley rats. Animals were allocated into one of the two groups: tetrandrine group and vehicle group. Tetrandrine (20 mg/kg) or vehicle was administered by gavage every 12 hours for consecutive 8 days. After 8 days of tetrandrine treatment, systemic hemodynamics and organ blood flows were measured on the next morning after an overnight fast, using radioactive microsphere method. Mean arterial pressure (96 +/- 2 vs. 118 +/- 4 mmHg) and systemic vascular resistance (254 +/- 35 vs. 369 +/- 5 dyn.sec.cm5 x 10(3)/100 g body wt) were significantly decreased in the tetrandine group as compared to the vehicle group. The cardiac-index (35.2 +/- 2.7 vs. 25.5 +/- 0.8 mL/min/100 g body wt) was increased in the tetrandrine group. The portal venous pressure, portal tributary blood flow, portal territory vascular resistance, renal blood flow, renal vascular resistance, heart rate and body weight were similar between the two groups. In conclusion, long-term treatment of tetrandrine reduced mean arterial pressure and systemic vascular resistance but did not change splanchnic or renal hemodynamics in normal rats.

Effect of endogenous nitric oxide on tumour necrosis factor-alpha-induced leukosequestration and IL-8 release in guinea-pigs airways in vivo

1. Tumour necrosis factor-alpha (TNF-alpha) is implicated in the pathogenesis of many pulmonary and airway diseases. TNF-alpha stimulation may release interleukin-8 (IL-8) in airways mediated via an increase in intracellular oxidant stress. In the present study, we have assessed leukosequestration and IL-8 release in the airways in response to intratracheal administration of human recombinant TNF-alpha, and examined the modulatory role of endogenous NO by pretreatment with a NO synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME). 2. TNF-alpha (10(2)-10(-4) u) was administered intratracheally in male guinea-pigs which were anaesthetized with urethane and were ventilated artificially. TNF-alpha induced a time- and dose-related increase in neutrophil numbers and a concomitant increase in human IL-8 equivalent level retrieved from bronchoalveolar lavage (BAL) with the peak effect at 10(3) u at 6 h of TNF-alpha injection (late phase). Intratracheal administration of recombinant human (rh)IL-8 (0.025, 0.25, 2.5 ng) producing a similar range of human IL-8 equivalent levels in BAL as measured in our results induced neutrophil recovery in BAL fluid to a similar extent. Administration of anti-IL-8 antibody prevented the late phase of neutrophil recruitment induced by TNF-alpha or rhIL-8. 3. Pretreatment with L-NAME significantly enhanced the TNF-alpha (10(3) u)-induced neutrophil recruitment and human IL-8 equivalents production at 6 h, but not at 1 h of TNF-alpha administration (early phase). L-Arginine reversed the responses to L-NAME. Pretreatment with 0.2% DMSO (i.v.) significantly inhibited TNF-alpha-induced neutrophil recruitment and human IL-8 equivalents release both in the early and late phase of the responses. Pretreatment with DMSO also inhibited the enhancement effect of L-NAME on the late phase of TNF-alpha-induced responses. DMSO failed to modify exogenous rhIL-8-induced neutrophil recruitment. Neither L-NAME nor DMSO alone induced any significant change in neutrophil numbers or human IL-8 equivalent level in BAL fluid. 4. Neutrophil depletion by cyclophosphamide pretreatment failed to modify TNF-alpha-induced human IL-8 equivalent release. 5. The expression of beta 2-integrin, CD11b/CD18 on neutrophils was increased only in the late but not early phase of TNF-alpha stimulation. L-NAME failed to modify these responses. 6. In conclusion, we demonstrated that NO may be an important endogenous inhibitor of TNF-alpha-induced leukocyte chemotaxis via inhibition of IL-8 production. Thus, the production of NO in airway inflammatory diseases may play a negative feedback role in self-limiting the magnitude of inflammatory responses.

A giant retroperitoneal ganglioneuroma with intraspinal involvement: report of one case

A 9-year-old girl was discovered to have had a huge retroperitoneal mass causing moderate hydronephrosis and anterior displacement of the right kidney and which was found on a renal ultrasonographic examination. A series of examinations including (1)IVP, (2) abdominal computed tomography, (3) MRI and(4) incisional biopsy revealed a giant dumb-bell shaped retroperitoneal ganglioneuroma with intraspinal involvement. Secondary scoliosis was also noticed. We successfully resected the huge ganglioneuroma of the right retroperitoneum in a two stage procedure: her postoperative course was uneventful.

Effects of carbon dioxide insufflation combined with changes in body position on blood gas and acid-base status in anesthetized llamas (Llama glama)

OBJECTIVE

To study the combined effects of intra-abdominal CO2 insufflation with changes in body position during laparoscopy in xylazine-ketamine-halothane anesthetized llamas.

STUDY DESIGN

Prospective, controlled study.

ANIMALS

Nine castrated, male llamas weighing 114 +/- 23 kg, 3 to 13 years old.

METHODS

Three llamas (preliminary study [PS] group) were used to study the effect of right, lateral, dorsal, and left lateral recumbency on gas exchange and acid-base status. The other six (experimental study [ES] group) were used to study the combined effects of changes in body position and CO2 insufflation to an intraabdominal pressure of 10 to 12 mm Hg. Heart rate, respiratory rate, and indirect arterial blood pressures (systolic [SAP], mean [MAP], and diastolic [DAP]) were recorded every 5 minutes during anesthesia. Arterial blood gases (PaO2 and PaCO2) and acid-base status (pHa and HCO3-) were measured immediately after induction of anesthesia and before each change of position.

RESULTS

In the PS group, significant decreases in SAP, MAP and PaCO2 and increases in PaO2 and pHa were observed when the llamas were turned from right lateral to dorsal recumbency. Values for HCO3- were lower than the postinduction values, but they remained unaffected by the changes in position. In the ES group, values for MAP were significantly lower when the llamas were placed in dorsal and left lateral recumbency than those observed during right lateral recumbency. Arterial O2 tension during right lateral recumbency was lower but returned to preinsufflation values when the llamas were placed in the dorsal position. All llamas recovered uneventfully within 30 minutes after termination of anesthesia.

CONCLUSIONS

Insufflation of CO2 and changing body position induce minor and transient changes in cardiovascular and respiratory function.

CLINICAL RELEVANCE

Laparoscopy with mild intra-abdominal CO2 insufflation (10 to 12 mm Hg) can be used safely in spontaneously breathing llamas anesthetized with xylazine, ketamine, and halothane.