Application of peroral cholangioscopy in an endemic area with high prevalence of hepatocellular carcinoma and choledocholithiasis

BACKGROUND/AIMS

Peroral cholangioscopy with a mother-baby scope system has been introduced for two decades. The paper presents the experience of peroral cholangioscopy at a university hospital in Taiwan where the prevalence of hepatocellular carcinoma and choledocholithiasis was high.

METHODOLOGY

A total of 27 sessions of peroral cholangioscopy were performed in 26 patients during a period of 4 years. Of them, 20 patients were for diagnosis and the rest 6 for removing the retained biliary stones.

RESULTS

The overall successful rate was 96.3%. The post-procedure complication rate was 11.5% with 2 cholangitis and 1 gram-negative septicemia. There were a total of 19 successful diagnostic sessions. These resulted in definite histological diagnosis in 5 patients and more precise diagnoses subsequently confirmed by surgery in 5 patients. In the remaining 9 patients with tentative diagnoses, 5 confirmed their diagnoses but 4 patients changed their diagnoses after peroral cholangioscopy. By this procedure, hepatocellular carcinoma and choledocholithiasis can be well identified and differentiated.

CONCLUSIONS

Peroral cholangioscopy is a safe and valuable modality in diagnosing and treating difficult biliary tract disease when handled with care. It is particularly useful in an endemic area with high prevalence of hepatocellular carcinoma and choledocholithiasis.

Sick sinus syndrome in a patient with single coronary artery anomaly

Single coronary artery anomaly is very rare. The reported manifestations include angina pectoris and congestive heart failure. Here we describe a case of single coronary artery anomaly presenting as sick sinus syndrome, which has no literature precedence. A 47-year-old woman had complained of intermittent dizziness for years. A Holter electrocardiogram showed sinus bradycardia and junctional or ventricular rhythm with a maximal ventricular pause of up to 3.2 seconds. Electrophysiologic study revealed prolonged corrected sinus nodal recovery time. Coronary angiography showed that the left anterior descending artery had a long course with a side branch originating from the proximal part and coursing anteriorly to the territory of the proximal portion of the right coronary artery. The sinus node is usually supplied by the sinoatrial branch via the right coronary artery. Aortography showed that the right coronary artery ostium was absent. A permanent pacemaker was implanted and the patient was discharged in good condition. The present case suggests that coronary artery anomaly may lead to compromised blood supply to the sinus node, and hence sick sinus syndrome.

Enhancement of dissolution and bioavailability of piroxicam in solid dispersion systems

Solid dispersion systems of water-insoluble piroxicam in polyethylene glycol (PEG) 4000 and in urea were prepared by fusion and solvent methods and were characterized in this study. The in vitro dissolution studies showed that the dispersion systems containing piroxicam and PEG4000 or urea gave faster dissolution than the corresponding simple mixtures. The differential scanning calorimetry (DSC) study indicated that the piroxicam-PEG system prepared by the fusion method is a solid dispersion, while the piroxicam-urea system prepared by the solvent method is likely to be a solid solution of piroxicam in urea. The storage testings showed that all dispersions were stable, except that uptake of water during storage may occur in the PEG system. A single-dose study with rabbits showed that the dispersion systems provided statistically significant to a higher extent and rate of bioavailability than the corresponding physical mixture (p < 0.05).

[Experimental studies on the diel rhythm changes of blood cAMP in growthing rats after mandibular retraction]

OBJECTIVE

To document the effect of orthopedic therapy on the metabolism of rats.

METHODS

Exerting backwards force on rats mandible and measuring concentration of rats' blood cAMP in three groups with radio-immunity. Drawing the time-concentration curve and making cosine analysis.

RESULTS

In natural state, there was a diel rhythm change of concentration of cAMP in rats' blood(P<0.05); After being imposed orthopedic forces to inhibit mandibular growth, the normal diel rhythm of cAMP in blood still existed(P<0.05). The results of parameter-comparison among groups were more complicated.

CONCLUSION

Further research is needed to clarify the mechanism whether local orthopedic forces influence the body metabolism.

Utility assessment for different clinical phases of breast cancer in Taiwan

BACKGROUND AND PURPOSE

Utility is an important index of health-related quality of life (HRQoL). The purpose of this study was to assess utility in different clinical phases of breast cancer in patients in Taiwan.

METHODS

Based on a review of HRQoL literature pertaining to breast cancer and medical records of 979 breast cancer patients admitted to National Taiwan University Hospital from 1991 to 1995, a semi-open checklist describing the diagnosis and treatment activities and impacts of different clinical phases of breast cancer was constructed. The checklist was then reviewed and revised in consultation with surgeons, medical oncologists, radiation oncologists, nurses, and breast cancer patients. Thirty-one clinical and public health experts were invited to assess the utility of each phase with the visual analog scale (VAS), standard gamble (SG), and time trade-off (TTO) methods, according to the description of the average patient's life in the checklist. The Delphi technique was used to reach expert consensus.

RESULTS

The VAS utility scores were highest during screening phases (100 or 90), lower in phases of incidental finding of a tumor (75) and diagnosis (70), and lower still in the initial treatment phases, especially during adjuvant chemotherapy (50). The scores improved during the follow-up phases. There was a higher score for breast-conserving surgery (65) than modified radical mastectomy (60) only in the early follow-up phase. The scores for recurrence or metastasis (30) and terminal stage were considerably lower and reached the lowest level (10 in a general ward and 12.5 at home or in a hospice) among all phases. The utility scores assessed by SG and TTO were higher than those assessed by VAS.

CONCLUSIONS

In this study, we established a consensus among clinical and public health experts on the impact of different clinical phases of breast cancer on utility. The results of this study may be useful in cross-cultural comparisons and cost-utility analyses for breast cancer.

Production and application of LPA polyclonal antibody

By using colloidal gold as a hapten carrier, a kind of antibody against lysophosphatidic acid (LPA) was developed and used to successfully detect 500 ng/mL LPA in dot immunogold filtration assay. Such application of the LPA antibody could offer us a way to diagnose ovarian cancer at its early stage.

Carcinosarcoma of the urinary bladder--an aggressive tumor with diverse histogenesis. A clinicopathologic study of 4 cases and review of the literature

OBJECTIVE

Carcinosarcomas of urinary bladder are rare malignant neoplasms. Seventy-eight cases have been previously described. The histologic composition of these tumors is variable, but diagnosis requires the presence of both epithelial and mesenchymal malignant components. We report 4 additional cases, with an emphasis on unusual histologic features.

METHODS

Histologic and immunohistochemical examinations were performed on bladder tumors from 4 patients. Clinicopathologic features of previously reported and current cases were reviewed and summarized.

RESULTS

Four patients (3 men, 1 woman) age 54 to 77 years were found to have polypoid masses in the urinary bladder. In all cases, histologic examination showed biphasic neoplasms with distinct mesenchymal and epithelial components. The morphologic and immunohistochemical characteristics of the tumors varied. One of the cases was remarkable for the presence of liposarcoma, malignant peripheral nerve sheath tumor, and micropapillary urothelial carcinoma. Two of the patients died 2 years after diagnosis, which is consistent with the previously reported aggressive nature of urinary bladder carcinosarcomas.

CONCLUSIONS

Carcinosarcomas of the urinary bladder are rare, aggressive malignant neoplasms. To our knowledge, a liposarcomatous component has been reported in only 1 case previously, and components of micropapillary urothelial carcinoma and malignant peripheral nerve sheath tumor have not been reported previously in carcinosarcomas of the urinary bladder. Because of the aggressive biologic behavior of these tumors, they should be identified promptly and treated appropriately.

Radiation damping compensation of selective pulses in water-protein exchange spectroscopy

The observation of nuclear Overhauser effects (NOEs) between bound water and biological macromolecules such as proteins and nucleic acids can be improved by inverting the water resonance selectively while compensating for radiation damping effects. The efficiency of inversion, the offset profiles, and the appearance of 2D NOE-NOESY spectra can be improved in comparison with earlier methods.

Hepatoprotection by "dangqui-long-hwei-wan" in male mice

Dangqui-long-hwei-wan (D.L.H.W.) is a traditional Chinese prescription for treatment of hepatitis. The hepatoprotective effects of D.L.H.W. and its constituents were investigated on carbon tetrachloride-induced liver damage mice. The hepatoprotective effect is more prominent for aqueous extracts of the complete formula of D.L.H.W., especially the one cited in the Chinese medical book Hsuan-Ming-Lun (H.M.L.). Our results are in accordance with those described in the Chinese medical literature and the indications suggested in clinical treatment (Wang, 1982). The results further indicate that Scutellariae Radix plays an important role in the hepatoprotective activity. Moschus could be omitted from D.L.H.W. with no significant influence on its effect. The underlying mechanism for the hepatoprotective effect of D.L.H.W. possibly results from the inhibition of the formation of *CCl3 and the enhancement of immunity of hepatitis-carrying patients.

Rectal carcinoma with stercoral ulcer perforation

We report a case of ruptured stercoral ulceration due to chronic constipation which is caused by rectal carcinoma. This case suffered from difficulty of stool passage for 5 months. Periumbilical pain and current-jelly stool were experienced before his admission. Physical examination revealed diffuse abdominal rebounding pain and laboratory data showed leukocytosis. Computed tomography demonstrated marked dilatation of the sigmoid colon with stool impaction due to neoplastic growth in the rectosigmoid junction. Thickening and edematous change of the colonic wall were noted. There was amorphous material with gas in the mesocolon, which indicated fecal peritonitis. Emergent operation with Hartman's procedure and left colostomy was performed. Diffuse pressure gangrene of the sigmoid colon wall with a perforating hole was identified. Pathologically, the resected colon specimen showed non-specific-acute and chronic inflammatory change. The perforating hole was surrounded by a necrotic border of ulcerative mucosa. After the operation, pelvic drainage was undertaken for 1 month and then the patient was discharged uneventfully.

Microbial populations, fermentation end-products, and aerobic stability of corn silage treated with ammonia or a propionic acid-based preservative

We studied the effects of ammonia treatment on microbial populations during the fermentation of corn silage. We also compared the effects of ammonia to a preservative containing buffered propionic acid and other antifungal compounds on the fermentation and aerobic stability of corn silage. In the first experiment, whole-plant corn was ensiled without treatment or treated with ammonia-N to supply an additional 0.3% N (fresh-forage basis). The addition of ammonia immediately increased silage pH and had no effect on numbers of lactic acid bacteria, but delayed their growth compared with untreated silage. Numbers of enterobacteria declined more slowly, but numbers of yeasts and molds declined more quickly in silage treated with ammonia. During the early stages of ensiling, lactic acid increased more rapidly in untreated than in treated silage. The reverse was true for acetic acid concentrations. When exposed to air, growth of yeasts and molds was delayed in ammonia-treated silage. In a second experiment, various levels (0.1 to 0.3%, fresh weight) of ammonium-N or a preservative with buffered propionic acid were added to whole-plant corn and allowed to ensile for 106 d. Silage treated with ammonia had a greater ratio of L- to D-lactic acid than did other silages. Untreated silage was aerobically stable for 32.3 h, whereas the low (42 h) and moderate (52.7 h) concentrations of both additives numerically improved aerobic stability. High concentrations of ammonia-N (0.3%) or a buffered propionic acid preservative (0.3%), markedly improved the aerobic stability of corn silage (82 and 69 h for ammonia and propionic acid-treated silage, respectively).

Regulation of ecdysteroid signalling: molecular cloning, characterization and expression of 3-dehydroecdysone 3 alpha-reductase, a novel eukaryotic member of the short-chain dehydrogenases/reductases superfamily from the cotton leafworm, Spodoptera littoralis

One route of inactivation of ecdysteroids in insects involves ecdysone oxidase-catalysed conversion into 3-dehydroecdysone (3DE), followed by irreversible reduction by 3DE 3 alpha-reductase to 3-epiecdysone. The 3DE 3 alpha-reductase has been purified and subjected to limited amino acid sequencing. It occurs as two distinct forms, including a probable trimer of subunit molecular mass of approx. 26 kDa. A reverse-transcriptase PCR-based approach has been used to clone the cDNA (1.2 kb) encoding the 26 kDa protein. Northern blotting showed that the mRNA transcript was expressed in Malpighian tubules during the early stage of the last larval instar. Conceptual translation of the 3DE 3 alpha-reductase cDNA and database searching revealed that the enzyme belongs to the short-chain dehydrogenases/reductases superfamily. Furthermore, the enzyme is a novel eukaryotic 3-dehydrosteroid 3 alpha-reductase member of that family, whereas vertebrate 3-dehydrosteroid 3 alpha-reductases belong to the aldo-keto reductase (AKR) superfamily. Enzymically active recombinant 3DE 3 alpha-reductase has been produced using a baculovirus expression system. Surprisingly, we observed no similarity between this 3DE 3 alpha-reductase and a previously reported 3DE 3 beta-reductase, which acts on the same substrate and belongs to the AKR family.

Cytotoxic neolignans from the stem wood of Machilus obovatifolia

Four new cytotoxic neolignans, machilusol A (1), machilusol C (3), machilusol D (4), machilusol E (5) as well as two new inactive neolignans, machilusol B (2) and machilusol F (6), were isolated from the stem wood of Machilus obovatifolia. All structures were identified by means of spectroscopic analysis.

Effect of atrial fibrillation on pulmonary venous flow patterns assessed by Doppler transesophageal echocardiography

STUDY OBJECTIVES

To investigate the effect of atrial fibrillation (AF) on pulmonary venous flow (PVF) patterns in a cohort with nonrheumatic AF.

DESIGN AND SETTINGS

A prospective and controlled study undertaken at a tertiary referral medical center.

PATIENTS AND MEASUREMENTS

The echocardiographic parameters of left superior PVF as assessed by Doppler transesophageal echocardiography in 40 patients with chronic AF (group 1) were compared to those of 33 volunteers with sinus rhythm (group 2) and well-matched baseline characteristics.

RESULTS

: All group 1 patients presented with single systolic forward flow (SFF) patterns. In contrast, single and double SFF patterns were found equally in group 2. With regard to reverse flow (RF), most group 1 patients (33 of 40) had an early systolic RF and none had atrial RF; however, most group 2 subjects (29 of 33) had an atrial RF. Some of the group 1 patients (17%) had a late systolic RF in the absence of significant mitral regurgitation. In group 1, the SFF appeared later and disappeared earlier than in group 2. The mean systolic peak velocity and time-velocity integral (TVI) of the SFF were significantly lower in group 1 compared to group 2. The diastolic peak velocity and TVI were not significantly different between groups.

CONCLUSIONS

: Our data indicate that AF independently and significantly affects the PVF and leads to characteristic flow patterns different from sinus rhythm. The presence of AF reduces SFF in addition to the absence of atrial RF. These changes in the flow patterns should be taken into account while interpreting the implications of PVF in the presence of AF.

Crystal and molecular structure of an eight-coodinate N-methyltetraphenylporphyrin complex: diacetato(N-methyl-meso-tetraphenylporphyrinato)thallium(III)

The crystal structure of diacetato(N-methyl-meso-tetraphenylporphyrinato)thallium(III), Tl(N-Me-tpp)(OAc)2 (1), was established, and the coordination sphere around the Tl3+ ion is described as an eight-coordinate square-based antiprism in which two cis chelating bidentate OAc- groups occupy two apical sites. The plane of the three pyrrole nitrogen atoms (i.e., N(1), N(3), N(4)) strongly bonded to Tl3+ is adopted as a reference plane 3N. The pyrrole N(2) ring bearing the methyl group (i.e., C(45)H3) is the most deviated one from the 3N plane, making a dihedral angle of 21.4 degrees, whereas smaller angles of 9.1 degrees, 7.1 degrees, and 0.9 degree occur with pyrroles N(1), N(3), and N(4), respectively. Because of its larger size, the thallium(III) ion Tl3+ is considerably out of the 3N plane; its displacement of 1.17 A is in the same direction as that of the two apical OAc- ligands. The intermolecular acetate exchange process for 1 in THF-d8 solvent is examined through 1H NMR temperature-dependent measurements. In the slow-exchange region, the methyl and carbonyl carbons of the OAc- groups in 1 are separately located at delta 18.6 [3J(Tl-13C) = 405 Hz] and 170.8 [2J(Tl-13C) = 334 Hz] at -80 degrees C, respectively.

Microporous segmented polyetherurethane vascular graft: I. Dependency of graft morphology and mechanical properties on compositions and fabrication conditions

The influence of polyurethane compositions and fabrication conditions on the pore morphology and mechanical properties of microporous segmented polyetherurethane (SPEU) grafts, which were produced by the coagulation technique, were carefully investigated in this article. SPEU resins based on polytetramethylene oxide (PTMO) were synthesized by the solution polymerization method. Different types of coagulant were adapted to examine the feasibility of producing a microporous SPEU graft with good structural regularity. The experimental results indicate that a microporous SPEU graft with a uniform pore structure can be fabricated quite conveniently by using a proper concentration of water and ethanol mixed coagulant. Tensile tests demonstrated that the fabricated microporous SPEU grafts possess high mechanical strengths and satisfy the requirements as vessel replacements. The burst strength test also revealed that the SPEU graft can sustain extremely high internal pressure. Furthermore, a high compliant SPEU (high porosity) graft can be obtained by blending a proper amount of "soluble filler" (i.e., free PTMO polyol in this study) into the SPEU resin.

Distal end of the atrioventricular nodal artery predicts the risk of atrioventricular block during slow pathway catheter ablation of atrioventricular nodal re-entrant tachycardia

OBJECTIVE

To search for a reliable anatomical landmark within Koch's triangle to predict the risk of atrioventricular (AV) block during radiofrequency slow pathway catheter ablation of AV nodal re-entrant tachycardia (AVNRT).

PATIENTS AND METHODS

To test the hypothesis that the distal end of the AV nodal artery represents the anatomical location of the AV node, and thus could be a useful landmark for predicting the risk of AV block, 128 consecutive patients with AVNRT receiving slow pathway catheter ablation were prospectively studied in two phases. In phase I (77 patients), angiographic demonstration of the AV nodal artery and its ending was performed at the end of the ablation procedure, whereas in the subsequent phase II study (51 patients), the angiography was performed immediately before catheter ablation to assess the value of identifying this new landmark in reducing the risk of AV block. Multiple electrophysiologic and anatomical parameters were analysed. The former included the atrial activation sequence between the His bundle recording site (HBE) and the coronary sinus orifice or the catheter ablation site, either during AVNRT or during sinus rhythm. The latter included the spatial distances between the distal end of the AV nodal artery and the HBE and the final catheter ablation site, and the distance between the HBE and the tricuspid border at the coronary sinus orifice floor.

RESULTS

In phase I, nine of the 77 patients had complications of transient (seven patients) or permanent (two patients) complete AV block during stepwise, anatomy guided slow pathway catheter ablation. These nine patients had a wider distance between the HBE and the distal end of the AV nodal artery, and a closer approximation of the catheter ablation site to the distal end of the AV nodal artery, which independently predicted the risk of AV block. In contrast, none of the available electrophysiologic parameters were shown to be reliable. When the distance between the distal end of the AV nodal artery and the ablation target site was more than 2 mm, the complication of AV block virtually never occurred. In phase II, all 51 patients had successful elimination of the slow pathways without complication when the ablation procedure was guided by preceding angiography with identification of the distal end of the AV nodal artery.

CONCLUSIONS

The distal end of the AV nodal artery shown by angiography serves as a useful landmark for the prediction of the risk of AV block during slow pathway catheter ablation of AVNRT.

Metal complexes of N-tosylamidoporphyrin: cis-acetato-N-tosylimido-meso-tetraphenylporphyrinatothallium(III) and trans-acetato-N-tosylimido-meso-tetraphenylporphyrinatogallium(III)

The crystal structures of acetato-N-tosylimido-meso-tetraphenylporphyrinatothallium(III), Tl(N-NTs-tpp)(OAc) (1), and acetato-N-tosylimido-meso-tetraphenylporphyrinatogallium(III), Ga(N-NTs-tpp)(OAc) (2), were determined. The coordination sphere around the Tl3+ ion is a distorted square-based pyramid in which the apical site is occupied by a chelating bidentate OAc- group, whereas for the Ga3+ ion, it is a distorted trigonal bipyramid with O(3), N(3), and N(5) lying in the equatorial plane. The porphyrin ring in the two complexes is distorted to a large extent. For the Tl3+ complex, the pyrrole ring bonded to the NTs ligand lies in a plane with a dihedral angle of 50.8 degrees with respect to the 3N plane, which contains the three pyrrole nitrogens bonded to Tl3+, but for the Ga3+ complex, this angle is found to be only 24.5 degrees. In the former complex, Tl3+ and N(5) are located on the same side at 1.18 and 1.29 A from its 3N plane, but in the latter one, Ga3+ and N(5) are located on different sides at -0.15 and 1.31 A from its 3N plane. The free energy of activation at the coalescence temperature Tc for the intermolecular acetate exchange process in 1 in CD2Cl2 solvent is found to be delta G++171 = 36.0 kJ/mol through 1H NMR temperature-dependent measurements. In the slow-exchange region, the methyl and carbonyl (CO) carbons of the OAc- group in 1 are separately located at delta 18.5 [3J(Tl-13C) = 220 Hz] and 176.3 [2J(Tl-13C) = 205 Hz] at -110 degrees C.

Surgical results in patients with hepatitis B-related hepatocellular carcinoma and positive hepatitis B early antigen

Hepatitis B virus (HBV) infection is the major risk factor in the pathogenesis of hepatocellular carcinoma (HCC). Patients who are positive for hepatitis B early antigen (HBeAg) have active liver disease. The present study aimed to evaluate the possible role of HBeAg in patients with resectable HCC. A series of 249 HCC patients with complete preoperative hepatitis marker who had undergone potentially curative resection were enrolled. Patients with hepatitis C virus infection were excluded. Of these patients, 27 were positive for hepatitis B surface antigen (HBsAg) and HBeAg (group I), 171 were positive for HBsAg and negative for HBeAg (group II), and 51 were negative for hepatitis B markers (group III). The clinicopathologic features and postoperative survivals were compared among the three groups. The prevalence of HBeAg was 10.8%. Group I patients were significantly younger and had worse liver function, smaller tumors, and a higher incidence of liver cirrhosis and chronic active hepatitis than those in groups II and III. No increase in tumor invasiveness was noted in group I patients. The operative morbidity, mortality, and postresection survival were comparable among the three groups. Our findings indicated that HBeAg positivity is not a negative factor for resection in HCC patients and has no significant influence on postresection survival.

Home telecare system using cable television plants--an experimental field trial

To solve the inconvenience of routine transportation of chronically ill and handicapped patients, this paper proposes a platform based on a hybrid fiber coaxial (HFC) network in Taiwan designed to make a home telecare system feasible. The aim of this home telecare system is to combine biomedical data, including three-channel electrocardiogram (ECG) and blood pressure (BP), video, and audio into a National Television Standard Committee (NTSC) channel for communication between the patient and healthcare provider. Digitized biomedical data and output from medical devices can be further modulated to a second audio program (SAP) subchannel which can be used for second-language audio in NTSC television signals. For long-distance transmission, we translate the digital biomedical data into the frequency domain using frequency shift key (FSK) technology and insert this signal into an SAP band. The whole system has been implemented and tested. The results obtained using this system clearly demonstrated that real-time video, audio, and biomedical data transmission are very clear with a carrier-to-noise ratio up to 43 dB.

The role of bcl-2, p53, and ki-67 index in predicting tumor recurrence for low grade superficial transitional cell bladder carcinoma

PURPOSE

We assess the prognostic significance of bcl-2 expression, p53 mutation and ki-67 index for low grade, superficial transitional cell bladder carcinoma.

MATERIALS AND METHODS

The medical records of 93 cases of primary, low grade (24 G1, 69 G2), superficial (70 pTa, 23 pT1) transitional cell carcinoma of the bladder were reviewed. Association of bcl-2, p53 and ki-67 index immunoreactivity with tumor grade and stage was examined. Prognostic significance of tumor grade, pathological stage, bcl-2 expression, p53 mutation and ki-67 index in predicting tumor recurrence was assessed.

RESULTS

Of the tumors 60 (70%) had p53 mutation and 9 (10.5%) expressed bcl-2. These 2 markers did not relate to tumor grade or pathological stage. Median ki-67 index was 10.9% and positively correlated with tumor grade. Recurrence was noted in 34.9% of patients with a median followup of 26 months (range 1 to 84). The ki-67 index was the only significant prognostic indicator in univariate and multivariate analyses. This marker can further distinguish grade 2 tumors with a favorable prognosis from those with an unfavorable outcome.

CONCLUSIONS

The ki-67 labeling index is an independent predictor of tumor recurrence for patients with primary superficial, low grade bladder cancers.

Modulation of ciliary activity by tumor necrosis factor-alpha in cultured sinus epithelial cells. Possible roles of nitric oxide

The primary function of well-differentiated ciliated epithelium in the paranasal sinus is to eliminate harmful agents through the beating action of cilia. Respiratory epithelium also contributes to local inflammatory processes through the release of various proinflammatory cytokines. Recently, considerable attention has been focused on the intimate relationship between the cytokine-dependent regulation of the ciliary beat frequency (CBF) and intra-cellular production of nitric oxide (NO) in ciliated epithelial cells. The aims of this study are to examine the effect of tumor necrosis factor-alpha (TNF-alpha), one of the major proinflammatory cytokines, on the ciliary activity of human sinus epithelial cells and to assess the hypothesis that NO is involved in this regulatory mechanism. Human maxillary or ethmoidal sinus mucosa (n = 23) were cultured by the explant-outgrowth method. CBF of the outgrowth ciliated cells was measured by the photoelectrical method before and after being treated with TNF-alpha (0.1, 1 and 10 ng/ml) or dexamethasone (10(-6) M and 10(-7) M). We also investigated the expression of nitric oxide synthase (NOS) isoforms, enzymes responsible for NO synthesis, by fluorescent immunohistochemistry. TNF-alpha increased CBF at relatively low concentrations (0.1 and 1 ng/ml) and decreased CBF at a high concentration (10 ng/ml). Dexamethasone decreased CBF at a concentration of 10(-6) M. Fluorescent immunohistochemistry demonstrated that the expression of inducible NOS was augmented by TNF-alpha and attenuated by dexamethasone, whereas that of endothelial NOS remained unchanged. We conclude that human sinus epithelial cells potentially contribute to the inflammatory process by regulating their ciliary motility through an NO-dependent pathway. Proinflammatory cytokines and steroids are able to modulate this mechanism by the induction or inhibition of expression of different NOS isoforms.

Effects of Welsh onion extracts on human platelet function in vitro

Welsh onion has been consumed for prevention of cardiovascular disorders. However, its underlying mechanisms are still unclear. This study investigated whether Welsh onion extracts can alter human platelet function (ie, platelet adhesion, aggregation, and thromboxane release). To clarify the underlying mechanisms, we also measured the intracellular calcium ([Ca2+]i) and cyclic nucleotide levels in platelets. Our results showed that 1) boiled extracts directly induced platelet aggregation in a dose-dependent manner; 2) raw extracts inhibited platelet adhesion and ADP-evoked platelet aggregation, while boiled extracts enhanced them; 3) raw green extract suppressed ADP-stimulated platelet [Ca2+]i elevation and thromboxane production, whereas boiled green extract enhanced them; 4) raw green extract elevated platelet cAMP level, whereas boiled green extract had no effect on cAMP level. Furthermore, the boiled green extract, but not the raw extract, induced pronounced platelet morphological changes. In conclusion, raw extracts of Welsh onion inhibit platelet function in vitro while boiled extracts activate platelets.

Prediction of common secondary structures of RNAs: a genetic algorithm approach

In this study we apply a genetic algorithm to a set of RNA sequences to find common RNA secondary structures. Our method is a three-step procedure. At the first stage of the procedure for each sequence, a genetic algorithm is used to optimize the structures in a population to a certain degree of stability. In this step, the free energy of a structure is the fitness criterion for the algorithm. Next, for each structure, we define a measure of structural conservation with respect to those in other sequences. We use this measure in a genetic algorithm to improve the structural similarity among sequences for the structures in the population of a sequence. Finally, we select those structures satisfying certain conditions of structural stability and similarity as predicted common structures for a set of RNA sequences. We have obtained satisfactory results from a set of tRNA, 5S rRNA, rev response elements (RRE) of HIV-1 and RRE of HIV-2/SIV, respectively.