Acylated pelargonidin 3-sambubioside-5-glucosides in Matthiola incana

Ten acylated pelargonidin 3-sambubioside-5-glucosides were isolated from the red-purple flowers of Matthiola incana, and also pelargonidin 3-glucoside was isolated from the brownish-red flowers of this plant. FAB mass measurements of 10 acylated anthocyanins gave their molecular ions [M]+ at 903-1195 m/z, which were based on acylated pelargonidin 3-sambubioside-5-glucosides with malonic acid, sinapic acid, p-coumaric acid, caffeic acid and/or ferulic acid. This was confirmed by the analysis of NMR spectra and the experiments of acid and alkaline hydrolysis. By spectral and chemical methods, seven of the 10 pigments were determined to be pelargonidin 3-O-[2-O-(2-O-(acyl-I)-beta-D-xylopyranosyl)- 6-O-(acyl-II)-beta-D-glucopyranoside]-5-O-[6-O-(malonyl)-beta-D- glucopyranoside], in which acyl moieties varied between sinapic, ferulic, caffeic and p-coumaric acids. The occurrence of these pigments was examined in 10 red-purple, 10 salmon-pink, three apricot and three copper colour cultivars of M. incana by HPLC. The acylated pelargonidin 3-sambubioside-5-glucosides were present as the dominant pigments in the red-purple, salmon-pink and apricot colour cultivars. On the other hand, pelargonidin 3-glucoside was present as a dominant anthocyanin in the copper colour cultivars and also pelargonidin 3-sambubioside-5-glucoside was confirmed by HPLC as a minor pigment in the copper colour flowers.

Genetic analysis of the chromosomal region encoding lysophospholipase L2 of Vibrio cholerae O1

From the Tn5-inserted mutant library of Vibrio cholerae O1, we found a mutant, NF404, which lost the production of both hemolysin and cholera toxin (CT) even though the Tn5-insertion site was out side from the structural genes for hemolysin and CT. Cloning and sequencing analysis of the homologous region from the wild-type strain, revealed that the sequence spanning the coding region of an ORF1 nominated as lypA, encoding a 39.5 kDa protein. Deduced amino acid sequence of the lypA gene had 37.6% identity to the lysophospholipase L2 (EC 3.1.1.5) of Escherichia coli. In the downstream of lypA, a second open reading frame (ORF2) encoding an unknown protein with molecular weight of 19.9 kDa was found. Assaying the lysophospholipase L2 activity in the cell extract of E.coli harboring lypA in an expression vector showed clear increase in the enzymatic activity.

Bronchoalveolar lavage fluid findings in patients with chronic hepatitis C virus infection

BACKGROUND

Hepatitis C virus (HCV) infection has recently been incriminated as an aetiological agent in idiopathic pulmonary fibrosis. This study was performed to determine the cellularity and lymphocyte phenotypes of bronchoalveolar lavage (BAL) fluid in patients with chronic hepatitis C.

METHODS

BAL fluid and lavage lymphocyte subsets from 13 patients (10 men) with active chronic hepatitis C, diagnosed by sustained elevated serum glutamic pyruvic transaminase and typical histological findings in the liver, were analysed. Lavage findings in these patients were compared with those from 13 healthy volunteers (eight men) as controls.

RESULTS

There was no difference in total cell counts in lavage fluid between the two groups. Lavage lymphocyte and eosinophil numbers were increased in patients with chronic hepatitis C. Surface marker analysis of the lymphocyte populations showed increases in CD2, CD3, CD4, and HLA-DR. CD4/CD8 ratios were not different.

CONCLUSIONS

The numbers of lymphocytes and eosinophils in BAL fluid are increased in patients with chronic hepatitis C. These findings suggest that HCV infection may trigger alveolitis.

Detection of the gene for toxic shock syndrome toxin 1 in Staphylococcus aureus by enzyme-labelled oligonucleotide probes

A colony hybridisation method with enzyme-labelled oligonucleotide probes was developed to detect the gene for toxic shock syndrome toxin 1 (tst). For rapid identification, bacterial colonies were transferred from agar plates directly on to nylon membranes. These procedures took only 3 h. Results obtained by this test correlated well with those obtained by the reverse passive latex agglutination test. Thus, this method is convenient and reliable for the detection of tst in staphylococci, which could be useful for both research and clinical purposes. This method demonstrated that tst was more prevalent in methicillin-resistant Staphylococcus aureus (56%) than in methicillin-susceptible S. aureus (4%).

Digital tomosynthesis imaging of the lung

We report our preliminary results of pulmonary imaging by digital tomosynthesis, and describe some advantages of these digitally processed longitudinal tomographic images. Digital tomosynthesis of the lung was performed in 60 subjects, including 56 patients with a localized lesion or diffuse disseminated lesions, with a fluororadiographic TV unit with linear tomographic capability, in conjunction with an image processing unit. Dual energy subtraction digital tomosynthesis was also available in our system. Multiple longitudinal tomographs of the lung, which were reconstructed from a single set of tomographic image data, facilitated easy evaluation of the morphology of pulmonary abnormalities together with related broncho-vascular structures located in the same longitudinal plane as the lesion, and were immune from any problem caused by inconsistent depth of respiration. The image quality of the reconstructed tomographs was greatly improved by digital image processing to reduce tomographic blur and enhance image clarity. Dual energy subtraction digital tomosynthesis was effective in clearly showing the size, configuration, and distribution of calcification in the lesion. Digital tomosynthesis provided useful information in making the roentgenologic diagnosis of pulmonary lesions.

[Analysis of cells and proteins in bronchoalveolar lavage fluid]

We studied cells and proteins in bronchoalveolar lavage fluid examined at the First Department of Internal Medicine of Shinshu University Hospital between 1990 and 1994. The samples came from 21 healthy subjects and from 216 patients with various diseases. Lymphocyte counts were abnormally high in patients with bronchiolitis obliterans organizing pneumonia. Sjögren's syndrome, sarcoidosis and hypersensitivity pneumonitis. Neutrophil counts were very high in the patients with diffuse panbronchiolitis and in those with high-altitude pulmonary edema, and eosinophil counts were high in those with eosinophilic pneumonia. The CD4:CD8 ratio was significantly higher in the patients with stage I sarcoidosis than in the healthy subjects. The total protein concentration and the albumin concentration were significantly higher in the patients with eosinophilic pneumonia and in those with high-altitude pulmonary edema than in the healthy subjects, and these findings suggest that in those two conditions the permeability of the pulmonary microvasculature was abnormally high.

[Pulmonary malignant fibrous histiocytoma presenting as hemothorax]

A 39-year-old woman, who suffered from a sudden episode of severe left-sided back pain, was admitted to our hospital because of hemothorax. Chest CT scans revealed a mass extending from the left hilum to the posterior thoracic wall. The mass occluded the left pulmonary artery at the left main bronchus. Examination of a frozen section of a specimen obtained during a thoracotomy showed a sarcomatous tumor. A left pneumonectomy was then performed. Microscopic examination of a specimen revealed that the tumor was composed of spindle cells with cellular atypia and mitosis forming fascicles and storiform arrays. Malignant fibrous histiocytoma (storiform-pleomorphic pattern) was diagnosed. Chemotherapy was carried out six times during the year after surgery. No recurrence of the tumor has been seen during 20 months of follow-up.

An aminopeptidase inhibitor, bestatin, enhances progesterone and oestradiol secretion by porcine granulosa cells stimulated with follicle stimulating hormone in vitro

We examined the presence of cell surface aminopeptidase on cultured porcine granulosa cells by employing the aminopeptidase assay using alanine-p-nitroanilide and histochemical staining using L-leucyl-beta-naphthylamide. Porcine granulosa cells obtained from follicles 4-5 mm in diameter were cultured for 7 days. The aminopeptidase assay showed that the porcine granulosa cell culture had aminopeptidase activity and that this activity was inhibited in a dose-dependent manner by bestatin which binds to cell surfaces and inhibits cell surface aminopeptidases. Histochemical staining also indicated that cultured granulosa cells had aminopeptidase activity. Porcine granulosa cells were cultured in the presence or absence of porcine follicle stimulating hormone (FSH, 3.125 nmol/l) and/or bestatin (0.4, 4.0 and 40.0 micrograms/ml) for 7 days, and the production of progesterone and oestradiol was measured. In the presence of porcine FSH, the production of progesterone and oestradiol by granulosa cells was increased significantly by approximately 5- and 2-fold respectively. These increases were enhanced further by bestatin (40.0 micrograms/ml). In the absence of porcine FSH, progesterone production was enhanced by bestatin (40.0 micrograms/ml), whereas no significant effect of bestatin on oestradiol secretion was observed. These findings indicate that the inhibition of membrane-bound aminopeptidase(s) on the cell surfaces affects the steroidogenesis of granulosa cells, and that these aminopeptidase(s) are important regulators of granulosa cell differentiation.

Estimation of aortic wall sclerosis in hypertension by use of carotid pulse tracing and cine magnetic resonance

In order to evaluate aortic wall sclerosis in hypertension, the authors studied the following two parameters of carotid pulse tracing and ascending aortic wall distensibility by using cine magnetic resonance (MR) in 15 age- and sex-matched normal volunteers (NC) (mean age, fifty-four years old) and 15 hypertensive patients (HT) (mean age, fifty-four years old). As the parameters of carotid pulse tracing, they measured the interval from aortic second heart sound to dicrotic notch (A2-DN), and the height from dicrotic notch to top/total height of carotid pulse tracing (b/a ratio). Ascending aortic distensibility was calculated from the following formula: (max area - min area)/(min area x pulse pressure). A2-DN interval was lower in HT than in NC (18.4 +/- 7.9 vs 31.5 +/- 9.2 ms, P < 0.01). The b/a ratio was lower in HT than in NC (0.34 +/- 0.07 vs 0.44 +/- 0.09, P < 0.01). Ascending aortic distensibility was lower in HT than in NC (2.08 +/- 1.37 vs 7.26 +/- 2.51 x 10(-3) mmHg(-1), P < 0.01). In conclusion, ascending aortic wall sclerosis is advanced in hypertension. A2-DN interval and b/a ratio measured by carotid pulse tracing are useful indicators in evaluating the ascending aortic wall distensibility in hypertension.

Evaluation of aortic distensibility in patients with coronary artery disease by use of cine magnetic resonance

To evaluate the aortic wall sclerosis in patients with coronary artery disease (CAD), the authors measured the aortic distensibility (AD) at the ascending and descending aorta by using cine magnetic resonance (MR). Cine MR was performed in 15 patients with CAD and 15 normal controls (NCs). Patients with CAD had angiographically significant coronary arterial stenosis and almost normal left ventricular function. Age and sex were matched in the patients with CAD and the NCs. Ascending and descending aortic areas of transverse image were measured in the maximum and minimum frames. AD was calculated from the following formula: (max area - min area)/(min area x pulse pressure). Although systolic and diastolic blood pressures showed no significant differences between patients with CAD and NC, AD was significantly lower in patients with CAD than in the NCs in each transverse section (P < 0.05). In conclusion, it is indicated that aortic wall sclerosis is advanced in patients with CAD.

Five new anthocyanins, ternatins A3, B4, B3, B2, and D2, from Clitoria ternatea flowers

Five new ternatins 1-5 have been isolated from Clitoria ternatea flowers, and the structures have been determined by chemical and spectroscopic methods as delphinidin 3-malonylG having 3'-GCG-5'-GCG, 3'-GCG-5'-GC, 3'-GCGCG-5'-GC, 3'-GCGC-5'-GCG, and 3'-GCGC-5'-GC side chains, respectively, in which G is D-glucose and C is p-coumaric acid. Pigment 1 had symmetric 3',5'-side chains. Compounds 3 and 4 are structural isomers. These ternatins were shown to form an intramolecular stacking between the aglycon ring and the 3',5'-side chains in solution.

[Two cases of primary Sjögren's syndrome with pulmonary involvement histopathological study of open-lung biopsy specimens]

We report two cases of primary Sjögren's syndrome with pulmonary involvement, in which open lung biopsies were done. The patient in the first case was a 58-year-old woman and the patient in the second case was a 54-year-old woman. Both patients were admitted to our hospital because of dry coughing and exertional dyspnea. Chest X-ray films and CT scans showed interstitial shadows in both cases and multiple bullae in the first case. Pulmonary-function tests showed decreased diffusing capacity, and examination of bronchoalveolar lavage fluid revealed increased percentages of lymphocytes. Open-lung biopsy specimens showed thickening of the alveolar septa and interstitial mononuclear cell infiltration, composed predominantly of lymphocytes, with lymphoid follicles in both cases, and peribronchiolar mononuclear cell infiltration in the first case. Therefore, the histopathological diagnosis was cellular interstitial pneumonia with lymphoid follicles. Both patients were treated with oral corticosteroids. Symptoms were relieved and laboratory findings improved.

[Isolation of Vibrio cholerae in imported frozen seafood and their cholera-enterotoxin production]

A survey study for Vibrio cholerae in imported seafood was conducted during January 1991 to December 1994. A total of 7,439 specimens (approximately 20% of all imported food) were randomly picked up and examined for contamination of V. cholerae. Among these, V. cholerae O1 were isolated from 9 specimens, but they were all cholerae enterotoxin (CT)-negative. In terms of V. cholerae non-O1, a total of 2,803 specimens (37.4%) were contaminated with this vibrio. Shrimp, especially the ones still in their shells and imported from Asian countries such as India and Indonesia, were highly contaminated with V. cholerae. Although no strains of V. cholerae O1 isolated in this study produced CT, 2 strains of V. cholerae non-O1 were proved to be CT-producers. Taking together the high contamination of V. cholerae in imported seafood and a part of those strains producing CT, we believe that careful survey for the possible contamination of V. choleare in imported seafood is necessary.

Acute respiratory distress syndrome due to methicillin-resistant Staphylococcus aureus sepsis in hyper-IgE syndrome

We report the case of a 34 year old woman with acute respiratory distress syndrome (ARDS) and disseminated intravascular coagulation (DIC) due to methicillin-resistant Staphylococcus aureus (MRSA) sepsis with hyperimmunoglobulin E syndrome (HIES). Although chemotactic activity of neutrophils was impaired in this patient, neutrophils accumulated in the lungs as assessed by bronchoalveolar lavage fluid (BALF) counts. In addition to antibiotics and oxygen therapy, the administration of recombinant human granulocyte colony-stimulating factor (rhG-CSF) resulted in a remarkable recovery.

Granulosa cells express integrin alpha 6: possible involvement of integrin alpha 6 in folliculogenesis

To identify differentiation antigens of granulosa cells, we have raised two monoclonal antibodies against porcine granulosa cells (POG-2 antibody) and human granulosa cells (OG-1 antibody). Analysis of N-terminal amino acid sequences of purified OG-1 and POG-2 antigens revealed that they were identical to human integrin alpha 6 and its porcine homolog, respectively. An immunohistochemical study showed that integrin alpha 6 was highly expressed on granulosa cells in preovulatory follicles in the human ovary, whereas it was highly expressed on granulosa cells in small follicles in the porcine ovary. As a common characteristic of integrin alpha 6 expression in both ovaries, granulosa cells located in inner layers, which are not in contact with the basal lamina, expressed integrin alpha 6 on the cell surface. This expression profile suggests that the interaction between integrin and extracellular matrices occurs in the granulosa cells located in inner layers. This cell surface interaction is reported to modulate soluble signals to the cells. Since the expression of integrin alpha 6 on inner-layer granulosa cells is related to stages of differentiation, this interaction may be involved in folliculogenesis.

Magnetic resonance imaging of neurogenic tumors of the thoracic inlet: determination of the parent nerve

To investigate the value of magnetic resonance imaging (MRI) in determining the parent nerves of neurogenic tumors in the thoracic inlet, analysis of MR images was performed in nine patients with surgically resected neurogenic tumors in the thoracic inlet (two neurofibromas and one schwannoma of the vagus nerve, three schwannomas of the brachial plexus, and two schwannomas and one ganglioneuroma of the sympathetic nerves). These MR images were compared with surgical and pathologic findings. The multidirectional capability and excellent tissue contrast of MRI facilitated recognition of the location, shape, and extent of the tumors. MRI, which permitted an easy understanding of the spatial relation between the tumors and the subclavian vessels, scalenus muscles, and brachial plexus, was useful in determining the nerves of origin. Two neurofibromas, four of six schwannomas, and one ganglioneuroma were recognized to extend along the axes of the parent nerves on MR images. MRI is useful in determining the parent nerve of neurogenic tumors in the thoracic inlet and is helpful in planning surgical treatment of these tumors.

X-ray Holographic Microscopy of Biological Specimens with an Electronic Zooming Tube

X-ray holographic microscopy of biological specimens has been performed using in-line holography with the following improvements: (i) an electronic zooming tube is utilized as a detector, and (ii) the object planes are restricted by a metal frame which is not transparent to X-rays at the wavelengths used in the present experiments. The latter modification is useful in computer reconstruction and serves as a reference area where there are no photons in the reconstructed images. This system can minimize the inclusion of errors when recording and reading out holograms compared with methods using an X-ray resist as a detector, or optical reconstruction methods. Two-dimensional images of human cells have been successfully obtained with the present system. Comparison of these images with optical images revealed a good coincidence in structure outlines but not in internal structure images. Holographic observation of HeLa cells at different wavelengths showed a wavelength dependence of the reconstructed images. Since the electronic zooming tube is applicable to a wide range of X-ray wavelengths and has a promising potential to improve its resolution, these results strongly suggest that the present system is a good candidate for the development and establishment of an X-ray holographic microscopy system.

[Bacteriological studies of travellar's diarrhoea. 5) Analysis of enteropathogenic bacteria at Osaka Airport Quarantine Station from January 1992 through September 3rd, 1994]

During the last 2 years and 8 months before the closure of Osaka Airport Quarantine Station (from Jan. 1992 to Sep. 3, 1994), a total of 7,421,909 overseas travellers were quarantined. 15,919 reported themselves of suffering from diarrhoea. Bacteriological examination of a total of 6,031 individuals' stools were performed. 1) Various enteropathogenic bacteria were isolated from 31.2% of the stools examined. Isolated species were as follows: Plesiomonas shigelloides, 1,127 cases (59.9%); Vibrio parahaemolyticus, 293 cases (15.6%); Salmonella spp., 262 cases (13.9%); Shigella spp., 235 cases (12.5%); Aeromonas sobria, 93 cases (4.9%); V. cholerae non-O1, 69 cases (3.7%). 2) The enteropathogenic bacteria were isolated through out the year without any seasonal variation. 3) The major regions where the travellers were infected with the pathogens are as follows: V. cholerae non-O1 (NAG Vibrio) and enteropathogenic Escherichia coli, South-East and South-West Asia; Vibrio other than NAG, South-East and East Asia; Shigella, widely distributed but especially in India; P. shigelloides and Salmonella, widely distributed. 4) 2 strains of toxigenic (cholera toxin-producing) V. cholerae O139 were isolated from patients who had visited Indonesia and Thailand, respectively. 5) In 320 cases (17%), plural enteropathogenic bacteria were isolated from single patients, suggesting a high frequency of the mixed infections. 6) Among Shigella strains, S. sonnei were isolated the most, followed by S. flexneri (24.7%), S. boydii (8.8%) and S. dysenteriae (2.9%). 7) Among Salmonella serovers, Salmonella Enteritidis was isolated the most frequently (39 cases, 14.1%). 8) 218 (91.6%) of 238 Shigella strains and 103 (37.6%) of 276 Salmonella strains were resistant to one or more drugs tested (SM.CP.TC.KM.ABPC.NA.OFLX). 9) All of the 22 V. cholerae O1 strains were Ogawa, E1 Tor. Among them, 19 were toxigenic strains and 3 were non-toxigenic. 10) O4:K8 was the most frequently isolated serover of V. paraemolyticus. 87.4% of all V. parahaemolyticus strains were positive with thermostable direct hemolysin (TDH) gene, and 12.6% of them were positive with TDH-related hemolysin (TRH) gene by DNA-probe methods.

Further studies on the urinary metabolites of 2,4-dinitrotoluene and 2,6-dinitrotoluene in the male Wistar rat

1. Conjugates of 2,4-dinitrobenzyl alcohol (2,4-DNB) and 2,6-dinitrobenzyl alcohol (2,6-DNB), which were major urinary metabolites of the male Wistar rat dosed orally with 2,4-dinitrotoluene (2,4-DNT) or 2,6-dinitrotoluene (2,6-DNT), were examined by hplc using potassium 2,4-dinitrobenzyl glucuronide (2,4-DNB-G), potassium 2,6-dinitrobenzyl glucuronide (2,6-DNB-G), pyridinium 2,4-dinitrobenzyl sulphate (2,4-DNB-S), and pyridinium 2,6-dinitrobenzyl sulphate (2,6-DNB-S) as authentic compounds. Other metabolites were also examined by hplc. 2. Conjugates detected from urine following administration of 2,4-DNT and 2,6-DNT were 2,4-DNB-G and 2,6-DNB-G, which accounted for about 10.7 and 17.4% of the administered dose respectively. No peaks corresponding to pyridinium 2,4-DNB-S and pyridinium 2,6-DNB-S were detected in urine samples. 3. 2-Amino-4-nitrobenzoic acid (0.71%), 4-amino-2-nitrobenzoic acid (0.52%) and 4-acetylamino-2-nitrobenzoic acid (3.9%), in addition to known metabolites 4-amino-2-nitrotoluene (0.04%), 2,4-DNB (0.25%), 2,4-dinitrobenzoic acid (6.9%) and 4-acetylamino-2-aminobenzoic acid (3.4%), were detected in ether extracts of urine of rat given 2,4-DNT. 2,6-Dinitrobenzoic acid (0.17%) and two known metabolites, 2-amino-6-nitrotoluene (0.44%) and 2,6-DNB (0.53%), were detected in ether extracts of urine of rat given 2,6-DNT.

High concentrations of cholecystokinin octapeptide suppress protein kinase C activity in guinea pig pancreatic acini

In pancreatic acini, calcium-mobilizing agents increase intracellular calcium and stimulate the production of diacylglycerol, and then activate protein kinase C (PKC). However, there are few studies which have examined the activation of PKC in intact acini. To examine the activation of PKC in intact acini by calcium-mobilizing agents, we measured the binding of [3H]phorbol-12,13-dibutyrate (PDBu) to intact acini. Acini were incubated with 10 nM [3H]PDBu at 25 degrees C with or without agents. The binding reactions were terminated by filtration. The filters were counted by a scintillation counter after washing. Acini possessed a single class of binding sites to PDBu, with Kd = 70 nM. CCK-8 and carbachol upregulated the binding affinity of PKC to PDBu in the acini. The ability of calcium-mobilizing agents to increase binding of [3H]PDBu to the acini had a close correlation to their ability to stimulate the amylase secretion from the acini, and higher concentrations of CCK-8 for amylase secretion suppressed binding of [3H]PDBu to the acini. 8Br-cAMP, 8Br-cGMP, and calcium ionophore did not inhibit the maximal activation of PKC induced by CCK-8. The calmodulin inhibitor W7 did not reverse the inhibitory effect of higher concentrations of CCK-8 on PKC activation. These results indicate that calcium-mobilizing agents upregulate the binding affinity of PKC to PDBu in intact acini, and that higher concentrations of CCK-8 for amylase secretion may activate the intracellular mechanism that inhibits PKC activity in acini. This inhibitory mechanism was mediated by some other mechanism other than cAMP-, cGMP-, calcium- and calmodulin-dependent mechanisms.

Fucoidin, a potent inhibitor of leukocyte rolling, prevents neutrophil influx into phorbol-ester-induced inflammatory sites in rabbit lungs

The polysaccharide fucoidin, a homopolymer of sulfated L-fucose, is known, by interfering with the function of L-selectin, to inhibit leukocyte rolling, which is an early and essential step in the process of leukocyte extravasation into inflamed sites. We tested the inhibitory effect of fucoidin on neutrophil accumulation in lung inflammation induced by phorbol myristate acetate and peritoneal inflammation induced by thioglycollate in rabbits. Pretreatment (10 mg/kg) followed by continuous administration (10 mg/kg/h) of fucoidin dramatically reduced the number of neutrophils recruited into the lungs (determined by neutrophil counts in bronchoalveolar lavage fluid; 97.7 +/- 0.52% reduction) and peritoneal cavity (determined by neutrophil counts in peritoneal lavage fluid; 98.4 +/- 1.29% reduction). Fucoidin treatment also increased the systemic neutrophil count. These results suggest that the inhibition of leukocyte rolling, which may be a primary function of fucoidin, leads to a reduction of neutrophil accumulation at inflammatory sites, which may be beneficial for attenuating neutrophil-mediated tissue injury.

Augmented sympathoadrenal activity during treadmill exercise in patients with Wolff-Parkinson-White syndrome and atrial fibrillation

It is believed that reciprocating tachycardia and accessory pathways play important roles in atrial fibrillation (AF) in patients with Wolff-Parkinson-White (WPW) syndrome. However, the mechanism by which AF occurs is not yet fully understood. This study was performed to evaluate the contribution of sympathoadrenal activity to the onset of AF in patients with WPW syndrome. Symptom-limited treadmill exercise testing was performed and plasma norepinephrine and epinephrine concentrations were measured simultaneously in 27 patients with WPW syndrome and 20 control subjects. In 13 patients with WPW syndrome and AF, plasma norepinephrine and epinephrine concentrations increased to 3.69 +/- 2.44 and 0.76 +/- 0.69 ng/ml at maximum exercise, respectively. These values were significantly higher (p < 0.001) than those in control subjects and in patients without AF. Pretreatment with 0.2 mg/kg of propranolol significantly reduced the incidence of exercise-induced atrial premature complexes (chi 2 = 7.33, p < 0.05). With oral beta-blockade for an average of 22.8 months, the incidence of AF decreased significantly from 1.77 +/- 0.53/patient per year to 0.33 +/- 0.57/patient per year (p < 0.001). Augmented sympathoadrenal activity in patients with WPW syndrome may contribute to AF.