3-D Ultrafast Ultrasound Imaging of Microbubbles Trapped Using an Acoustic Vortex

Increasing the local concentration of microbubbles (MBs) within the blood flow plays a crucial role in several medical applications, but there are few imaging modalities available for volumetric tracking of the aggregated MBs in real time. Here we describe a device integrating acoustic vortex tweezers (AVTs) and ultrasound plane-wave imaging (PWI) to achieve the goal of controlling the spatial distribution of MBs in blood vessels and simultaneously monitoring this process using the same probe. Experiments were conducted using a 5-MHz 2-D array ultrasound probe (with three cycles of excitation at an acoustic pressure of 2000 kPa) and 1.2- [Formula: see text]-diameter MBs at a flow rate of 20 mm/s. The AVT waveform was produced by modulating the repetition frequency of the transmitted pulse asymmetrically (4 and 8 kHz at the inflow and outflow ends, respectively). In order to simultaneously capture MBs and carry out imaging with the same probe, the asymmetric AVT pulse signal and the ultrasound-imaging pulse signal were arranged in a staggered series, and the imaging was carried out using plane-wave pulses at nine angles (-7° to 7°) in compounded PWI (volume rate: 200 Hz). Microscopy observations showed that freely suspended MBs could indeed be gathered by the asymmetric AVT in the flow field to form an MBs cluster with a spot size of about [Formula: see text], which could resist the flow to remain at a fixed location for about 22 s. After the asymmetric AVT signal and the ultrasound-imaging pulse signal were turned on for 1 s, the ultrasound 3-D image showed that the signal intensity of the MB clusters increased by 13.1 dB ± 2.9 dB in relation to the background area. These results show that the proposed strategy can be used to accumulate flowing MBs at a desired location and to simultaneously observe this phenomenon. This tool could be used in the future to improve the outcomes of MB-related treatments for various diseases.

Tornado-inspired acoustic vortex tweezer for trapping and manipulating microbubbles

Spatially concentrating and manipulating biotherapeutic agents within the circulatory system is a longstanding challenge in medical applications due to the high velocity of blood flow, which greatly limits drug leakage and retention of the drug in the targeted region. To circumvent the disadvantages of current methods for systemic drug delivery, we propose tornado-inspired acoustic vortex tweezer (AVT) that generates net forces for noninvasive intravascular trapping of lipid-shelled gaseous microbubbles (MBs). MBs are used in a diverse range of medical applications, including as ultrasound contrast agents, for permeabilizing vessels, and as drug/gene carriers. We demonstrate that AVT can be used to successfully trap MBs and increase their local concentration in both static and flow conditions. Furthermore, MBs signals within mouse capillaries could be locally improved 1.7-fold and the location of trapped MBs could still be manipulated during the initiation of AVT. The proposed AVT technique is a compact, easy-to-use, and biocompatible method that enables systemic drug administration with extremely low doses.

Optical design of an LED motorcycle headlamp with compound reflectors and a toric lens

An optical design for a new white LED motorcycle headlamp is presented. The motorcycle headlamp designed in this study comprises a white LED module, an elliptical reflector, a parabolic reflector, and a toric lens. The light emitted from the white LED module is located at the first focal point of the elliptical reflector and focuses on the second focal point. The second focal point of the elliptical reflector and the focal point of the parabolic reflector are confocal. We use nonsequential rays to improve the optical efficiency of the compound reflectors. The toric spherical lens allows the device to meet the Economic Commission of Europe, regulation no. 113 (ECE R113). Furthermore, good uniformity is obtained by using aspherical surface optimization of the same toric lens. The reflectivity of the reflector is 95%, and the transmittance of each lens surface is 98%. The average deviation of the high beam is 14.17%, and the optical efficiency is 66.45%.

Abstract 2472: Acute colitis and colitis-associated cancer are exacerbated in mice deficient N-deacetylase/N-sulfotransferase-4

NDST4 is one member of N-deacetylase/N-sulfotransferase (heparan glucosaminyl) (NDST) family, which are responsible for heparan sulfate (HS) biosynthesis on a core protein to form heparan sulfate proteoglycans (HSPGs). The HS chains of HSPGs bind to and regulate their functions of various growth factors, cytokines and chemokines. HSPGs ubiquitously reside on cell surface, inside the cell, and in the extracellular matrix. Importantly, the content and distribution of HSPGs are altered during tumorigenesis. In the study, 30 (57.7%) of 52 primary colorectal carcinomas showed a dramatic reduction in NDST4 RNA transcripts, and genetic loss of NDST4 was significantly associated with poor survival of patients with colorectal cancer. We further generated an Ndst4-knockout mouse strain, which could develop and reproduce normally. Notably, using the dextran sodium sulfate mouse model of acute colitis, Ndst4 deficiency resulted in a significantly higher disease activity index and obviously hyperemic appearance in the cecum. In the development of colitis-associated cancer, the size of colonic tumors induced by azoxymethane/dextran sodium sulfate was significantly increased in Ndst4-deficient mice compared with wild-type mice. Taken together, loss-of-function of NDST4 might impair the modification of HS chains of specific HSPGs leading to tumor-promoting inflammation in the colon. The full spectrum of signaling pathways contributed by NDST4 to colitis and tumor progression remains to be elucidated.

Citation Format: Tzu-Ming Jao, Ming-Hong Tsai, Chi-Yen Huang, Sheng-Tai Tzeng, Jing-Xing Lee, Wei-Chen Lo, Che-Wei Chang, Ya-Chien Yang. Acute colitis and colitis-associated cancer are exacerbated in mice deficient N-deacetylase/N-sulfotransferase-4. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2472. doi:10.1158/1538-7445.AM2014-2472

The causal relationship between electricity consumption and economic growth in a Gaming and Tourism Center: The case of Macao SAR, the People's Republic of China

A number of Asian cities decided to establish gaming and resort facilities in order to capitalize on the growing number of gamblers and their family members in Asia. In doing so, they expect to sustain economic growth but, on the other hand, will consume a considerable amount of energy. Nevertheless, the causal relationship between economic growth and electricity consumption in this type of service-oriented territories has never been investigated. Using the historical data obtained from the Government of Macao SAR, we found that electricity consumption and economic growth in terms of gross domestic product are co-integrated for the period of 1999 Quarter 1-2008 Quarter 4. Moreover, vector error correction (VEC) models indicated a lack of short-run relationships but showed that there was a long-run equilibrium relationship between electricity consumption and gross domestic product. The accuracy of VEC models was assessed by using the mean squared error and the mean absolute error. The error analysis shows that VEC models reproduced time series of gross domestic product and electricity consumption in difference form accurately.

Bridging bronchus in an infant demonstrated by direct coronal computed tomography and three-dimensional rendering display

Bridging bronchus is a rare anomaly in which the right lower lobe bronchus arises from the left main bronchus and bridges the lower mediastinum. The first reported case was diagnosed at autopsy in 1976. The second reported case was diagnosed by bronchography confirmed at autopsy in 1980. We describe a 9-month-old infant with such an anomaly. Our patient presented with cough, shortness of breath, and rhinorrhea with no fever or sputum production. The physical examination revealed only coarse breath sound and chest retraction with no other abnormalities. Chest radiography showed decreased lung volume and shifting of the mediastinum to the left. Diagnosis of this anomaly was not possible with computed tomography (CT) axial imaging. Direct coronal CT and 3D rendering with the surface-shaded display technique showed a small right upper lobe bronchus and proximal stenotic left main bronchus, with the intermediate bronchus originating from the left main bronchus and crossing the midline to enter the contralateral lung.

Modulation of catecholamine release by endogenous adenosine in the rat adrenal medulla

Adenosine was shown to inhibit norepinephrine (NE) release from sympathetic nerve endings. The purpose of this study was to examine whether endogenous adenosine restrains NE and epinephrine release from the adrenal medulla. The effects of an adenosine receptor antagonist, 1,3-dipropyl-8-(p-sulfophenyl) xanthine (DPSPX), on epinephrine and NE release induced by intravenous administration of insulin in conscious rats were examined. Plasma catecholamines were measured by HPLC with an electrochemical detector. DPSPX significantly increased plasma catecholamine in both control rats and rats treated with insulin. The effect of DPSPX on plasma catecholamine was significantly greater in rats treated with insulin. Additional experiments were performed in adrenalectomized rats to investigate the contribution of the adrenal medulla to the effect of DPSPX on plasma catecholamine. The effect of DPSPX and insulin on epinephrine in adrenalectomized rats was significantly reduced compared with that of the controls. Finally, we tested whether endogenous adenosine restrains catecholamine secretion partially through inhibiting the renin-angiotensin system. The effect of DPSPX on plasma catecholamine in rats pretreated with captopril (an angiotensin-converting enzyme inhibitor) was reduced. These results demonstrate that under basal physiological conditions, endogenous adenosine tonically inhibits catecholamine secretion from the adrenal medulla, and this effect is augmented when the sympathetic system is stimulated. The effect of endogenous adenosine on catecholamine secretion from the adrenal medulla is achieved partially through the inhibitory effect of adenosine on the renin-angiotensin system.

Epstein-Barr virus-associated hemophagocytic syndrome masquerading as lymphoma: a case report

Virus-associated hemophagocytic syndrome (VAHS) is a non-neoplastic, generalized histiocytic proliferation with prominent hemophagocytosis associated with a systemic viral infection. Although Epstein-Barr virus (EBV) is one candidate virus for this association, thorough serologic and molecular biologic studies to determine the presence of the viral infection have been lacking in many reports. Whereas elevated liver function tests are common findings in patients with VAHS, exudative ascites and abdominal lymphadenopathy are rare. We describe a case of EBV-AHS masquerading as lymphoma in which treatment with intravenous immunoglobulins was associated with complete clinical remission at 2 years and 6 months after the onset. Regardless of the exact mechanism responsible for ascites formation in VAHS, this case adds support to the possible involvement of EBV in patients with abdominal lymphadenopathy and ascites.

Asymmetric inter- and intramolecular cyclopropanation of alkenes catalyzed by chiral ruthenium porphyrins. Synthesis and crystal structure of a chiral metalloporphyrin carbene complex

Extensive investigations of asymmetric intermolecular cyclopropanation of terminal alkenes with diazoacetates catalyzed by ruthenium porphyrin [Ru(P*)(CO)(EtOH)] (1, H2P = 5,10,15,20-tetrakis[(1S,4R,5R,8S)-1,2,3,4,5,6,7,8-octahydro-1,4:5,8-dimethanoanthracene-9-yl]porphyrin) and the application of catalyst 1 to asymmetric intramolecular cyclopropanation of allylic or homoallylic diazoacetates are described. The intermolecular cyclopropanation of styrene and its derivatives with ethyl diazoacetate afforded the corresponding cyclopropyl esters in up to 98% ee with high trans/cis ratios of up to 36 and extremely high catalyst turnovers of up to 1.1 x 10(4). Examination of the effects of temperature, diazoacetate, solvent, and substituent in the intermolecular cyclopropanation reveals that (i) both enantioselectivity and trans selectivity increase with decreasing temperature, (ii) sterically encumbered diazoacetates N2CHCO2R, such as R = Bu(t), and donor solvents, such as diethyl ether and tetrahydrofuran, are beneficial to the trans selectivity, and (iii) electron-donating para substituents on styrene accelerate the cyclopropanations, with the log(k(X)/k(H)) vs sigma(+) plot for para-substituted styrenes p-X-C6H4CH=CH2 (X = MeO, Me, Cl, CF3) exhibiting good linearity with a small negative rho(+) value of -0.44 +/- 0.09. In the case of intramolecular cyclopropanation, complex 1 promoted the decomposition of a series of allylic diazoacetates to form the cyclopropyl lactones in up to 85% ee, contributing the first efficient metalloporphyrin catalyst for an asymmetric intramolecular cyclopropanation. Both the inter- and intramolecular cyclopropanations were proposed to proceed via a reactive chiral ruthenium carbene intermediate. The enantioselectivities in these processes were rationalized on the basis of the X-ray crystal structures of closely related stable chiral carbene complexes [Ru(P*)(CPh2)] (2) and [Ru(P*)(C(Ph)CO2CH2CH=CH2)] (3) obtained from reactions of complex 1 with N2CPh2 and N2C(Ph)CO2CH2CH=CH2, respectively.

Acute disseminated encephalomyelitis in autoimmune hemolytic anemia

A 16-year-old female with chronic autoimmune hemolytic anemia is presented. She was diagnosed with acute disseminated encephalomyelitis by clinical findings and magnetic resonance imaging (MRI), and the condition occurred after a systemic infection with Cryptococcus neoformans. Intravenous immunoglobulin therapy remarkably improved the patient's neurologic deficit and resolved abnormalities evidenced on MRI. To our knowledge, this report is the first of a pediatric patient with autoimmune hemolytic anemia complicated by acute disseminated encephalomyelitis that developed after an apparently successful treatment of cryptococcal meningitis.

Modulatory effects of carbon monoxide on baroreflex activation in nucleus tractus solitarii of rats

Recent studies suggest that carbon monoxide (CO), which is produced in significant quantities in many brain regions, may function as a neurotransmitter. Heme oxygenase catalyzes the metabolism of heme to CO and biliverdin; however, the physiological role of CO in central cardiovascular regulation was not well understood. In the present study, we evaluated the baroreflex response of CO in the nucleus tractus solitarii (NTS) of rats. Male Sprague-Dawley rats were anesthetized with urethane, and blood pressure and heart rate were monitored intra-arterially. Unilateral microinjection (60 nL) of hematin, a heme molecule cleaved by heme oxygenase to yield CO, into the NTS produced prominent dose-related depressor and bradycardic effects. Baroreflex responses were elicited by increasing doses of phenylephrine (10 to 30 microg/kg IV) before and after intra-NTS administration of zinc deuteroporphyrin 2,4-bis-glycol (ZnDPBG) (1 nmol), an inhibitor of heme oxygenase activity, or vehicle alone. The reflex bradycardia elicited by phenylephrine was significantly inhibited by pretreatment with ZnDPBG. Furthermore, the inhibitory effect of ZnDPBG on baroreflex activation was dose dependent. These results suggest CO formed by brain heme oxygenase plays a significant role in central cardiovascular regulation and that inhibition of heme oxygenase attenuated baroreflex activation.

Identification of a novel mouse p53 target gene DDA3

We have identified a novel p53 regulated gene designated DDA3 through differential mRNA display on IW32 erythroleukemia cells containing a temperature sensitive p53 allele, tsp53val-135. DDA3 mRNA induction could be observed in all sublines expressing tsp53val-135 cultured at permissive temperature as well as in NIH3T3 cells undergoing DNA damage. Upregulation of DDA3 could be detected within 2 h after down-shifting the temperature to 32.5 degrees C; upon shifting back to 38.5 degrees C, DDA3 mRNA rapidly degraded with a half-life of less than 2 h. Actinomycin D, but not cycloheximide, inhibited the p53 dependent DDA3 induction, suggesting that the activation is through transcriptional regulation and does not require de novo protein synthesis. DDA3 was expressed in multiple mouse tissues including brain, spleen, lung, kidney and testis. Full-length DDA3 cDNA was cloned and it contained an open reading frame predicted to encode a proline rich protein of 329 amino acids. Overexpression of DDA3 in H1299 lung carcinoma cells suppressed colony formation. These results suggest that DDA3 is a p53-regulated gene that might participate in the p53-mediated growth suppression.

The influence of intravenous omeprazole on intragastric pH and outcomes in patients with peptic ulcer bleeding after successful endoscopic therapy--a prospective randomized comparative trial

BACKGROUND/AIMS

The role of omeprazole in preventing rebleeding in patients with peptic ulcer bleeding after successful endoscopic therapy has been controversial. In this study, we used 3 different formulas of intravenous omeprazole in the above patients. We wished to compare the intragastric pH and outcomes among them.

METHODOLOGY

Between July 1996 and May 1997, after having obtained initial hemostasis with endoscopic therapy, a total of 20 patients with peptic ulcer bleeding (spurting/oozing/non-bleeding visible vessel: 6/4/10) received intravenous bolus of omeprazole 20 mg every 3 hours; 20 patients (3/5/12) received intravenous bolus of omeprazole 40 mg every 6 hours; and, 20 patients (5/4/11) received intravenous bolus of omeprazole 80 mg every 12 hours for 3 days. One intragastric pH meter (Gastrograph Mark III, Medical Instruments Corp. Switzerland) was used to record 24-hour intragastic pH.

RESULTS

The intragastric pH in the patients receiving omeprazole 20 mg every 3 hours was 6.1, 6.0-6.2 (mean: 95% CI); in patients receiving omeprazole 40 mg every 6 hours it was 6.4, 6.2-6.5; and, in patients receiving omeprazole 80 mg every 12 hours it was 5.8, 5.7-5.9. The duration of intragastric pH > 6.0 in omeprazole 20 mg every 3 hours was 70.9%, 57.3%-84.4% (mean: 95% CI); in omeprazole 40 mg every 6 hours it was 83.1%, 73.1%-93.1%; and, in omeprazole 80 mg every 12 hours it was 66%, 51.5%-80.4%. Patients with peptic ulcers receiving omeprazole 40 mg intravenous bolus every 6 hours had the highest intragastric pH as compared with the other 2 groups (p < 0.0001). There were no significant differences concerning rebleeding rates, volume of blood transfusion, hospital stay, numbers of operation and mortality among the 3 groups.

CONCLUSIONS

After initial hemostasis had been obtained, patients with peptic ulcer bleeding receiving 40 mg intravenous bolus every 6 hours had the highest intragastric pH. However, they had similar outcomes with the other 2 groups.

Suspected nasopharyngeal carcinoma in three workers with long-term exposure to sulphuric acid vapour

Sulphuric acid vapour has been suspected of being an industrial carcinogen. In this study, a cluster is presented of three patients with nasopharyngeal carcinoma (NPC) who worked in the same building of a telecommunications conveyance station in southern Taiwan with long term exposure to sulphuric acid vapour concentrations as high as 0.18 mg/m3. All three workers were diagnosed with NPC within a 5 month period between September 1992, and March 1993. Compared with 19 other healthy workers from the same building, these three workers with NPC had worked significantly longer in this building than had the others (mean (SD) (years): 12.7 (0.6) v 7.4 (4.4); p = 0.01). With an in situ nucleic acid hybridisation and immunostaining method for colocalised Epstein-Barr virus (EBV) and secretory component (SC) protein among biopsy specimens of these three patients with NPCs, it was found that some tumour cells did not contain EBV and SC protein staining signals. These results indicate that EBV infection is not the only risk factor for NPC and long term exposure to relatively low concentrations of sulphuric acid vapour may be associated with the development of NPC.

Diagnosis of the congenital urethral anomalies of male child by voiding cystourethrography

Congenital urethral anomalies in boys are rare. This report concerns seven children with congenital urethral anomalies other than hypospadias from March 1995 to February 1998. Seven cases of congenital urethral anomalies were diagnosed by voiding cystourethrography (VCUG) from 1246 examinations of boys over a period of three years. There were four posterior urethral values, one anterior urethral valve, one anterior urethral diverticulum, and one megalourethra. Five of them had vesicoureteral reflux (VUR). Two cases of posterior urethral valve had renal failure in spite of surgery. Three cases exhibited renal cystic dysplasia. The clinical presentation and imaging findings are presented. Conventional fluoroscopically monitored VCUG is the principal examination used for bladder and urethra study in children. Therefore, in boys presenting the signs and symptoms related to voiding disturbance, VCUG is used to detect not only VUR but also anomalies in the bladder and urethra. In conclusion, VCUG is safe and essential for diagnosis of congenital urethral anomalies.

Influence of Helicobacter pylori on gastric secretion and gastrin release in normal Chinese subjects

BACKGROUND

Controversy exists concerning the influence of Helicobacter pylori on gastric secretion. Hyper-, normo- and hyposecretion of gastric acid in normal subjects with H pylori infection have been reported, although there is no such report for Chinese subjects. The goal of this study was to identify the effect of H pylori on gastric secretion in normal Chinese subjects.

METHODS

Twenty normal subjects with a normal upper gastrointestinal tract by endoscopy were recruited. H pylori status was assayed by a rapid urease test. Gastric secretion and gastrin release were also measured.

RESULTS

Among the subjects studied, nine were infected with H pylori. All enrolled subjects were males. Age and body weight were similar between both groups. No significant difference was found in basal acid output, maximal acid output, basal pepsin output or maximal pepsin output between the H pylori-positive group (median, 1.1 mmol/hour, 95% confidence interval 0.2-3.6 mmol/hour; 8.0, 3.0-18.3 mmol/hour; 0, -1.3-11.2 mmol/hour; and 4.1, -4.2-59.3 mmol/hour, respectively) and the H pylori-negative group (2.5, -1.3-11.3 mmol/hour; 12.2, 8.7-26.9 mmol/hour; 4.3, 1.8-13.5 mmol/hour; and 14.8, -5.7-73.0 mmol/hour, respectively). Serum basal gastrin and pepsinogen I concentration were 63.5, 50.0-78.6 pg/ml and 75.1, 50.6-89.8 ng/ml in the H pylori-positive group, and 65.9, 50.2-79.8 pg/ml and 79.1, 59.5-120.1 ng/ml in the H pylori-negative group (p > 0.05).

CONCLUSIONS

H pylori plays no role in the gastric secretion and gastrin release in normal Chinese subjects.

Effect of non-steroidal anti-inflammatory drugs on gastric and duodenal prostaglandin concentrations in patients with Helicobacter pylori infection

BACKGROUND/AIMS

Both Helicobacter pylori and non-steroidal anti-inflammatory drugs are reported to affect gastroduodenal prostaglandin synthesis. However, their influence on gastric mucosal prostaglandins remains unclear. The aim of this study was to investigate the influence of nonsteroidal anti-inflammatory drugs on mucosal prostaglandin synthesis in patients with Helicobacter pylori infection.

METHODOLOGY

We enrolled 87 Helicobacter pylori-infected patients in this study (gastric ulcer: 33, duodenal ulcer: 41, and non-ulcer dyspepsia: 13). Of them, 27 patients received non-steroidal anti-inflammatory drugs. Endoscopy was performed and biospy specimens from gastric body, antrum and duodenal bulb were assessed for Helicobacter pylori and prostaglandin concentration.

RESULTS

A significantly lower mucosal prostaglandin E2 level at gastric body (142.2 +/- 28.1 ng/mg vs. 222.0 +/- 12.4 ng/mg, mean +/- SEM) and antrum (131.3 +/- 26.4 ng/mg vs. 226.0 +/- 19.0 ng/mg) was noted in Helicobacter pylori-infected gastric ulcer patients with non-steroidal anti-inflammatory drugs ingestion than in that of patients without non-steroidal anti-inflammatory drugs ingestion (p < 0.05). Using a multivariate analysis, we found that non-steroidal anti-inflammatory drug was an independent variable affecting gastric and duodenal mucosal prostaglandin E2 synthesis in patients with Helicobacter pylori-infected gastric ulcer.

CONCLUSIONS

Non-steroidal anti-inflammatory drugs decrease gastroduodenal mucosal prostaglandin E2 synthesis in gastric ulcer patients with Helicobacter pylori infection.

Cardiovascular effects of nitric oxide and adenosine in the nucleus tractus solitarii of rats

It has been shown that nitric oxide (NO) is synthesized in the central nervous system as well as in vascular endothelial cells. We recently reported that NO was involved in central cardiovascular regulation, modulated the baroreflex, and was involved in a reciprocal release with excitatory amino acids in the nucleus tractus solitarii (NTS) of rats. We also reported previously that adenosine increased the release of glutamate in the NTS. The purpose of the present study was to investigate the possible interaction of NO and adenosine in the NTS. Male Sprague-Dawley rats were anesthetized with urethane, and blood pressure was monitored intra-arterially. Unilateral microinjection of L-arginine (3.3 nmol/60 nL) into the NTS produced decreases in blood pressure and heart rate. Microinjection of adenosine (2.3 nmol/60 nL) also produced depressive and bradycardic effects. These cardiovascular effects were attenuated by prior administration of the specific adenosine receptor antagonist DPSPX (0.92 nmol). Similarly, prior administration of NO synthase inhibitor NG-monomethyl-L-arginine or NG-nitro-L-arginine methyl ester significantly attenuated the depressive and bradycardic effects of adenosine. These results demonstrate a reciprocal attenuation of adenosine receptor antagonist and NO synthase inhibitor on L-arginine and adenosine responses, respectively, in the NTS and implicate an interaction between NO and adenosine in central cardiovascular regulation.

Predictive factors for rebleeding in patients with peptic ulcer bleeding after multipolar electrocoagulation: a retrospective analysis

The role of endoscopic therapy for peptic ulcer bleeding is well-documented. Nevertheless, rebleeding occurs in 10% to 30% of patients, and such patients are at high risk for death without early retreatment or definitive surgery. The aim of our study was to predict which patients would rebleed within 1 month after successful multipolar electrocoagulation of 100 patients with active peptic ulcer bleeding (spurting, oozing, or nonbleeding visible vessel). We had achieved initial hemostasis in 97 patients and carried out univariate and multivariate analyses to predict which patients would rebleed. Rebleeding occurred within 1 month in 17 (17.5%) patients. we correlated 20 clinical and endoscopic factors with rebleeding episodes. With univariate analysis, blood transfusion of 500 ml or more at entry (p < 0.0001) and use of cimetidine (p = 0.01) were statistically significant for rebleeding. With multivariate analysis, use of omeprazole was an independent factor for preventing rebleeding (odds ratio, 7.68; 95% confidence interval, 1.642-35.929). We suggest that omeprazole may help to prevent rebleeding in patients who have had hemostasis with multipolar electrocoagulation.

A prospective randomized comparative trial showing that omeprazole prevents rebleeding in patients with bleeding peptic ulcer after successful endoscopic therapy

BACKGROUND

A blood clot in a peptic ulcer is unstable in a low pH environment. The use of omeprazole may prevent rebleeding by elevating intragastric pH in patients with bleeding peptic ulcer after hemostasis has been achieved.

OBJECTIVES

To assess the influence of using omeprazole and cimetidine on 24-hour intragastric pH and to determine their ability to prevent rebleeding after having achieved initial hemostasis in patients with active bleeding or nonbleeding visible vessels.

METHODS

One hundred patients with bleeding peptic ulcers who had obtained initial hemostasis were enrolled in this randomized comparative trial. In the cimetidine group (n = 50), a 300-mg intravenous bolus of cimetidine was given, followed by a 1200-mg continuous infusion daily for 3 days. Thereafter, 400 mg of cimetidine was given orally twice daily for 2 months. In the omeprazole group (n = 50), a 40-mg intravenous bolus of omeprazole was given, followed by 160 mg of continuous infusion daily for 3 days. Thereafter, 20 mg of omeprazole was given orally once daily for 2 months. A pH meter was inserted in each patient's fundus under fluoroscopic guidance after the intravenous bolus of cimetidine or omeprazole had been administered.

RESULTS

The stigmata of recent hemorrhage before endoscopic therapy in the omeprazole and cimetidine groups were, respectively, spurting (9 vs 12), oozing (4 vs 9), and nonbleeding visible vessel (37 vs 29) (P > .05). The duration of intragastric pH higher than 6.0 was longer in the omeprazole group (mean [+/- SD], 84.4% +/- 22.9%) than that of the cimetidine group (mean [+/- SD], 53.5% +/- 32.3%) (P < .001). Rebleeding occurred in 2 patients (4%) in the omeprazole group and in 12 patients (24%) in the cimetidine group by day 14 after enrollment (P = .004). There was a tendency for patients in the omeprazole group to require less blood transfusion (median, 0 mL; range, 0-2500 mL) than those in the cimetidine group (median, 0 mL; range, 0-5000 mL) (P = .08). The hospital stay and number of operations and mortality rate were similar between both groups.

CONCLUSIONS

The use of omeprazole is more effective than cimetidine in increasing intragastric pH and reducing rebleeding episodes in patients with bleeding peptic ulcers after successful endoscopic therapy. This suggests that omeprazole should be used routinely after successful endoscopic therapy.

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.

Can optimal acid suppression prevent rebleeding in peptic ulcer patients with a non-bleeding visible vessel: a preliminary report of a randomized comparative study

BACKGROUND/AIMS

The hypothesis that profound acid suppression might prevent clot lysis and thus benefit patients with a non-bleeding visible vessel has not been confirmed. Omeprazole can suppress gastric acid remarkably and may be beneficial for patients with peptic ulcer bleeding.

METHODOLOGY

Fifty-two patients with a non-bleeding visible vessel at the ulcer base were enrolled and randomized into four groups (N = 13 in each group). In the cimetidine group, the patients received cimetidine 300 mg i.v. bolus followed by 300 mg i.v. every 6 hr during hospitalization. In the heater probe thermocoagulation + cimetidine group, the patients received heater probe thermocoagulation and cimetidine 300 mg i.v. bolus followed by 300 mg i.v. every 6 h during hospitalization. In the omeprazole q.d. group, the patients received omeprazole 40 mg i.v. bolus followed by 40 mg i.v. daily for two days. In the omeprazole q 12 h group, the patients received omeprazole 40 mg i.v. bolus followed by 40 mg i.v. every 12 h for two days. A 24 hr intragastric pH was recorded for every case.

RESULTS

The mean 24 hr intragastric pH were higher in the omeprazole q.d. (mean 5.8) and the omeprazole q 12 h groups (mean 6.4) than in the cimetidine (mean 4.3) and the heater probe thermocoagulation + cimetidine groups (mean 4.9) (p < 0.05). Rebleeding occurred in 5, 2, 2 and 2 patients in the cimetidine, heater probe thermocoagulation + cimetidine, omeprazole q.d., and omeprazole q 12 h groups, respectively (p > 0.05). Volume of blood transfusion and number of days in hospital were not statistically different among the four groups.

CONCLUSIONS

Omeprazole can remarkably suppress gastric acid when it is compared to that of the H2 receptor blocker. Patients with a non-bleeding visible vessel using omeprazole do not exhibit a decrease in the rebleeding rate as compared with those patients using cimetidine.

Cerebral arteriovenous malformations in children: neuroimaging findings

Cerebral arteriovenous malformations (CAVMs) are uncommon in children. CAVMs represent the most frequent intracranial vascular pathology at pediatric ages. This report concerns 13 children below the age of 16; all were identified between September 1995 and December 1996 with 14 CAVMs among them. All were proved by conventional cerebral angiography (CCA). Thirteen computed tomography (CT), 7 magnetic resonance images (MRI), 2 magnetic resonance angiography (MRA) and 13 conventional cerebral angiography (CCA) were analyzed. Most CAVMs nidus were located in cerebral hemispheres. Four in the temporal lobe, two in the parietal lobe, three in the frontal lobe, two in the occipital lobe, and three in the corpus callosum. One of them was of a mixed type with two nidi. The major clinical features of CAVMs were intracranial hemorrhage and seizures. Experience here was that MRI is superior to CT in showing the exact anatomic relationships of the nidus and in demonstrating the extent of CAVMs nidus obliteration after treatment. MRA provided a noninvasive means of studying blood vessels and vascular pathology in relationship to the CAVMs nidus. Standard angiography is still necessary to characterize in-flow and out-flow of vessels in CAVMs when definitive treatment is considered.

Clarithromycin in the combination therapy for the eradication of Helicobacter pylori in peptic ulcer disease

BACKGROUND

Clarithromycin is a new macrolide antibiotic which is known to be highly effective in eradicating Helicobacter pylori (H. pylori). In Chinese, the role of clarithromycin for H. pylori is still unclear.

METHODS

Between January 1995 and February 1996, 75 patients with active H. pylori-positive duodenal ulcer were enrolled in this study. Three groups were randomized to have (1) 2 x 150 mg nizatidine twice daily, 2 x 250 mg amoxicillin four times daily, and 2 x 250 mg clarithromycin three times daily for two weeks (niz-amox-clar group, N = 25); or (2) 20 mg omeprazole twice daily plus 2 x 250 mg clarithromycin three times daily for two weeks (ome-clar group, N = 25); or (3) 300 mg bismuth subsalicylate four times daily, and 2 x 250 mg amoxicillin four times daily, 250 mg metronidazole four times daily for two weeks (triple therapy group, N = 25). All the patients received H2 receptor antagonist (150 mg nizatidine or ranitidine, or 400 mg cimetidine, twice daily) for the consecutive six weeks.

RESULTS

The eradication rate of H. pylori eight weeks after the entry of study was 80%(20/25) in the niz-amox-clar group, 76%(19/25) in the ome-clar group, 88%(22/25) in the triple therapy group (p < 0.05 among the three groups). The ulcer healing rates eight weeks after the entry of study for the niz-amox-clar, the ome-amox, and the triple therapy groups were 84%(21/25), 80%(20/25), and 80%(20/25), respectively (p < 0.05 among the three groups). The number of patients experiencing adverse effects in the niz-amox-clar group, the ome-clar group, and the triple therapy group were 10(40%), 7(28%), and 4(16%), respectively (p > 0.05 among the three groups).

CONCLUSIONS

Both nizatidine/amoxicillin/clarithromycin and omeprazole/clarithromycin regimens can achieve good eradication rates and may provide an effective alternative anti-H. pylori treatment in duodenal ulcer diseases.

Light-microscopic studies of 3T3 cell plasma membrane alterations mediated by melittin

Various light microscopic techniques were used to study the effect of melittin, a major toxic constituent of honey bee venom, on plasma membranes of 3T3 mouse fibroblasts. Bright-field light microscopy and Trypan Blue dye exclusion were used to demonstrate changes in membrane permeability after exposure to melittin. Differential interference contrast (DIC) microscopy showed that membrane vesiculation induced by melittin was dose dependent. Using both fluorescent lipid and glycoprotein markers, we found that membrane vesicles were primarily composed of lipids. A sequence of events associated with vesicle formation was depicted by DIC and fluorescence microscopy. Confocal laser scanning fluorescence microscopy demonstrated a translocation of membrane glycoproteins from the plasma membrane to the cytosol following melittin treatment. The significance of membrane vesiculation and translocation of membrane glycoproteins in damaged cells is discussed.

Superior mesenteric artery syndrome

Superior mesenteric artery (SMA) syndrome is a rare clinical disease. We present a case of a 15-year-old girl with complaints of vomiting and epigastric pain during on admission. Her general appearance was tall and thin. She had the upper gastrointestinal (UGI) barium study, angiography and abdominal sonography performed to confirm the diagnosis of SMA syndrome. She received medical treatment and was discharged after the symptoms were relieved. Her followup had a smooth course in our out-patient department.

Gastric secretion in Chinese patients with cirrhosis

The role of gastric secretion has been controversial in patients with cirrhosis. Except for studies of gastric secretion in cirrhotic patients who underwent a shunt operation, there is no report correlating gastric secretion with portal pressure in patients with cirrhosis. In this study, we evaluated gastric secretion in cirrhotic patients and correlated it with hemodynamic parameters. Within 12 months, 20 normal volunteers and 16 cirrhotic patients were enrolled. Gastric secretion was assessed in all patients, but portal pressure hemodynamic studies were performed only in cirrhotic patients. We found that the median basal acid output, maximal acid output, and basal pepsin output in the controls (1.41 mmol/h, 9.2 mmol/h, and 0.02 mg/h, respectively) and in the cirrhotic patients (0.6 mmol/h, 7.84 mmol/h, and 1.5 mg/h, respectively) were not statistically different. However, maximal pepsin output was lower in the cirrhotic patients (1.5 mg/h) than in the normal subjects (5.14 mg/h) (p < 0.05). Gastric secretion correlated poorly with hepatic venous pressure gradient (HVPG) and the presence of congestive gastropathy in cirrhotic patients. The severity of congestive gastropathy correlated poorly with HVPG. Helicobacter pylori has difficulty replicating in the stomach when HVPG is > 14 mm Hg. We conclude that patients with cirrhosis have a lower maximal pepsin output than that of the healthy subjects. Gastric secretion correlates poorly with HVPG and the presence of congestive gastropathy in patients with cirrhosis.

De novo antimicrobial peptides with low mammalian cell toxicity

De novo antimicrobial peptides with the sequences: (KLAKKLA)n, (KLAKLAK)n (where n = 1,2,3), (KALKALK)3, (KLGKKLG)n, and (KAAKKAA)n (where n = 2,3), were prepared as the C-terminus amides. These peptides were designed to be perfectly amphipathic in helical conformations. Peptide antibacterial activity was tested against Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus. Peptide cytotoxicity was tested against human erythrocytes and 3T3 mouse fibroblasts. The 3T3 cell testing was a much more sensitive test of cytotoxicity. The peptides were much less lytic toward human erythrocytes than 3T3 cells. Peptide secondary structure in aqueous solution, sodium dodecylsulfate micelles, and phospholipid vesicles was estimated using circular dichroism spectroscopy. The leucine/alanine-containing 21-mers were bacteriostatic at 3-8 microM and cytotoxic to 3T3 cells at about 10 microM concentrations. The leucine/alanine- or leucine/glycine-containing 14-mers and the leucine/glycine 21-mer were bacteriostatic at 6-22 microM but had much lower cytotoxicity toward 3T3 cells and higher selectivities than the natural antimicrobial peptides magainin 2 amide and cecropin B amide. The 7-mer peptides are devoid of biological activity and of secondary structure in membrane mimetic environments. The 14-mer peptides and the glycine-containing 21-mer show modest levels of helicity in model membranes. The leucine/alanine-containing 21-mer peptides have substantial helicity in model membranes. The propensity to alpha-helical conformation of the peptides in amphipathic media is proportional to their 3T3 cell cytotoxicity.

Characteristics of patients with benign gastric outlet obstruction requiring surgery after endoscopic balloon dilation

OBJECTIVES

The aim of this study is to identify factors that will predict which patients with benign gastric outlet obstruction will not respond to endoscopic balloon dilation, in a long-term observation.

METHODS

Over a 51-month period, 42 patients with benign gastric outlet obstruction received endoscopic balloon dilation. The "through-the-scope" technique with the aid of a guide wire was used for dilation. Fifteen factors were analyzed prospectively in 40 patients. Multivariate analysis was used to find the independent factors of the failure of treatment.

RESULTS

The median follow-up period was 23 months (range 1-51 months). Twenty-eight (67%) patients achieved sustained improvement, and 14 (33%) patients underwent surgery. The overall symptom-free rates in 12, 24, 36, and 48 months were 85.3%, 78%, 68.8%, and 68.8%, respectively. The independent prognostic factor for failure of treatment was the need for more than two courses of endoscopic balloon dilation to relieve symptoms (odds ratio, 6.857; 95% confidence interval, 1,031-45,606).

CONCLUSIONS

Endoscopic balloon dilation for the treatment of benign gastric outlet obstructions is an effective alternative to surgery. Patient who needs more than two courses of endoscopic balloon dilation to relieve symptoms should receive surgery.

Intravenous omeprazole prevents rebleeding in peptic ulcer patients with a non-bleeding visible vessel: a preliminary report of a randomized controlled study

BACKGROUND

In patients with peptic ulcer bleeding, acid can enhance platelet disaggregation and cause lysis of the clot. Omeprazole, a potent acid suppressor, may be helpful in reducing their rebleeding rate.

METHODS

Between March and October 1994, 40 patients with a non-bleeding, visible vessel (NBVV) at ulcer bases were enrolled for study. They were randomized into four groups. Group 1 (n = 10) patients received cimetidine 300mg intravenously (i.v.) q6h; Group II (n = 10) patients received heater probe thermocoagulation therapy and cimetidine 300mg i.v. q6h; Group III (n = 10) patients received omeprazole 40mg intravenous bolus initially followed by 40mg i.v. qd and Group IV (n = 10) patients received omeprazole 40mg intravenous bolus initially followed by 40mg i.v. q12h. Endoscopic examination was done for follow-up, daily, for 1-3 days.

RESULTS

Preliminary results showed that the age, initial hemoglobin, ulcer size as well as NBVV size in Groups I-IV were not significantly different (p < 0.05). The rebleeding rates were 40% in Group I, 20% in Group II, 20% in Group III and 0% in Group IV, (p < 0.05 when Group IV is compared with Group I).

CONCLUSIONS

Intravenous omeprazole 40mg given q12h can reduce the rebleeding rate of patients with a NBVV.

Bleaching herbicide flurtamone interferes with phytoene desaturase

The mode of action of the furanone herbicide flurtamone and derivatives was investigated with cress seedlings and with the unicellular cyanobacterium Anacystis. Either in the light or in the dark these compounds inhibited the formation of alpha- and beta-carotene and all of the xanthophylls in the seedlings. Instead, phytoene, a precursor of colored carotenoids, was accumulated. In illuminated seedlings photooxidative destruction of chlorophyll was observed. The I(50) value of flurtamone inhibition of carotenoid biosynthesis in intact Anacystis cells and the K(1) value for interaction of flurtamone with phytoene desaturase with Anacystis thylakoids were 30 and 18 nanomoles, respectively. Concentrations of flurtamone which strongly inhibited carotenoid synthesis had no direct peroxidative activities and did not inhibit photosynthetic electron transport.

Analysis of antibody reactivities in ELISA using protein blots as antigen substrates: S-ELISA

We describe here a novel immunoassay procedure, designated strip-ELISA (S-ELISA), in which specific antigens are purified by SDS-PAGE, transferred to support membranes, and utilized in situ as substrate in routine ELISA procedures. Using two different lentivirus systems, simian immunodeficiency virus and equine infectious anemia virus, we demonstrate the utility of S-ELISA for screening hybridoma supernatants during production of monoclonal antibodies and for the dissection of polyclonal antibody responses into defined antigen specificities. The data presented here indicates that the S-ELISA combines the sensitivity of conventional ELISA with the specificity afforded by Western blotting procedures, producing a relatively simple and versatile assay for evaluating antibody reactivities.

[Evaluation of the causative bacteria of pneumonia in the elderly in recent years]

A study of 62 cases of elderly pneumonia (EP) in their sixties and eighties with etiologic bacteria confirmed by cultures of sputum, blood or pleural effusion was carried out Greater change of etiologic bacteria of EP in patients of eighties has been found when they were compared with those of sixties. In the group of eighties the incidence of Gram-negative bacilli increased (77%), including pseudomonas aeruginosa (48.39%), Klebsiella pneumoniae (17.35%) and Enteric coli (9.68%), while Staphylococcus aureus accounted only for 16.1%. There were 2 species of Streptococcus pneumoniae; both were mixed with other bacteria in cultures. In patients of eighties the etiologic agents isolated from pneumonia were more resistant to many common antibiotics. The above mentioned results suggest that the diagnosis of etiology of pneumonia in the elderly should be emphasized.

[Carcinoembryonic antigen assay in serum and pleural effusion of pulmonary malignancies and benign lesions]

Levels of carcinoembryonic antigen(CEA)in the serum and pleural effusion in malignancies (65) and benign (25) of lung were determined. There are 20 cases of adenocarcinoma, 16 undifferentiated carcinoma, 7 squamous cell carcinoma, 4 alveolar carcinoma, 12 unclassified carcinoma, 1 polymorphous adenoma, 1 mesothelioma, 1 thymoma, 1 metastatic cancer from kidney and 2 metastatic breast cancer. In the benign lesions, there are 20 tuberculosis, 2 heart failure, 1 pneumonia, 1 empyema and 1 cirrhosis. The mean of the CEA level in the serum of lung cancer group was 12.63 ng/ml as compared with that of the tuberculosis group, 3.01 ng/ml (P less than 0.01). The level of CEA in pleural fluid in the lung cancer group was 57.30 ng/ml as compared with that of tuberculosis group, 5.55 ng/ml (P less than 0.01). The content of CEA in the serum and pleural fluid in lung cancer group was remarkably different (P less than 0.01). CEA level in the serum of adenocarcinoma is the highest (mean 15.51 ng/ml). If we set 5 ng/ml as the margin of normal CEA level in serum, the positive rate for cancer would be 54.2%. It is suggested that the margin of CEA normal value be set at 10 ng/ml for the pleural fluid. Higher readings may imply cancer.

Depression of intramyocardial oxyhemoglobin dissociation by angiographic contrast media

The effect of the addition of radiographic contrast material (Renografin) to blood on the oxyhemoglobin dissociation curve and P50 was measured by a metabolic deoxygenation technique in a strongly buffered red cell suspension. With incubation time constant, increasing doses produced progressive decreases in P50. With incubation time varied at a constant dose, a decrease in P50 was seen after only one minute. In addition, in vivo studies were performed on 11 patients undergoing cardiac catheterization. Simultaneous proximal coronary sinus and aortic samples were drawn as controls, and then at one minute and five minutes after injection of the left coronary artery. In eight patients studies were performed after, and in three prior to left ventriculography. At one minute after left coronary injection there was a significant decrease of coronary sinus as compared to aortic P50 (p less than .10) (only when left ventriculography was performed prior to coronary arteriography). The magnitude of these effects in vivo is unknown, but they would be expected to be more severe in areas distal to a critical coronary lesion due to stasis of blood flow and ischemic metabolic changes.