Synthesis, characterization, and biological verification of asialoglycoprotein receptor-targeted lipopolysaccharide-encapsulated PLGA nanoparticles for the establishment of a liver fibrosis animal model

Liver fibrosis is generally preceded by various liver injuries and often leads to chronic liver diseases and even cirrhosis. Therefore, a liver fibrosis animal model is the cornerstone for the development of therapeutic strategies for hepatic diseases. Although administration of hepatotoxic substances and/or bile duct ligation have been widely performed to construct the in vivo model over the last decades, they are seriously hindered by time-consuming protocols, high mortality, and instability, indicating that an effective and safe approach for the induction of liver fibrosis is still urgently needed nowadays. In this study, we have developed asialoglycoprotein receptor (ASGPR)-targeted lipopolysaccharide (LPS)-loaded poly (lactic-co-glycolic acid) (PLGA) nanoparticles named ALPNPs for establishing an animal model of liver fibrosis. The ALPNPs are characterized as having a spherical nanostructure with size of 182.9 ± 8.89 nm and surface charge of -8.3 ± 1.48 mV. An anti-ASGPR antibody bound to the surface of the nanoparticles with a crosslinking efficiency of 95.03% allows ALPNPs to have hepatocyte-binding specificity. In comparison to free LPSs, the ALPNPs can induce higher aspartate aminotransferase and total bilirubin concentrations in plasma, reduce the blood flow rate in the portal system and the kidneys, and increase vascular resistance in the liver, kidneys, and collateral shunting vasculature. Based on histological and RNA-seq analyses, the ALPNPs can provide similar capability on inducing hepatic inflammation and fibrosis compared to free LPS but possess higher liver targetability than the naked drug. In addition, the ALPNPs are less toxic in organs other than the liver in comparison to free LPS, demonstrating that the ALPNPs do not elicit off-target effects in vivo. Given the aforementioned efficacies with other merits such as biocompatibility and drug release controllability provided by PLGA, we anticipate that the developed ALPNPs are highly applicable in establishing animal models of liver fibrosis in pre-clinical studies.

Role of the gut microbiota and their metabolites in hemodialysis patients

High serum phosphate levels in chronic kidney disease (CKD) are linked to adverse health outcomes, including cardiovascular disease, kidney disease progression, and all-cause mortality. This study is aimed to find out which microorganisms or microbial functions have a significant impact on higher calcium-phosphorus product (Ca x P) after they undergo hemodialysis (HD) treatment. Feces samples from 30 healthy controls, 15 dialysis patients with controlled Ca xP (HD), and 16 dialysis patients with higher Ca xP (HDHCP) were collected to perform in 16S amplicon sequencing. We found gut microbial composition was significantly different between hemodialysis patients and healthy controls. Three phyla including Firmicutes, Actinobacteria, and Proteobacteria were significantly enriched in hemodialysis patients. Although only one genus, Lachnospiraceae_FCS020_group, was significantly increased in higher Ca xP group, there were four metabolic pathways predicted by PICRUSt significantly increased in higher Ca xP group and associated with causing VC, including the pentose phosphate pathway, steroid biosynthesis, terpenoid backbone biosynthesis, and fatty acid elongation pathway. Characterizing dysbiosis of gut microbiome played the important role in hemodialysis patients.

[Association between plasma selenium and the risk of impaired glucose regulation]

Objective: To investigate the association between plasma selenium exposure and the risk of impaired glucose regulation (IGR). Methods: A case-control study was conducted to select IGR patients who were admitted to the outpatient clinic of the Department of Endocrinology to perform oral glucose tolerance test(OGTT) at the Tongji Hospital affiliated to the Tongji Medical College from September 2004 to 2016 as a case group. Participants with normal glucose tolerance recruited from an unselected group of population undergoing routine health examinations in the same hospital were selected as a control group. The control group was matched according to the age (±5 years old) and sex of the case group. The inclusion criteria for subjects recruited were as follows: age ≥30 years, body mass index (BMI) <40 kg/m(2), no history of a diagnosis of IGR or type 2 diabetes, and no history of receiving pharmacological treatment for hyperlipidemia or hypertension. Patients with any clinically systemic disease such as neurological or endocrine disease, acute illness, chronic inflammatory disease or infectious disease were excluded from the study. A total of 1 957 subjects, 897 in the case group and 1 060 in the control group, were included. Questionnaires were used to collect information of all subjects, and peripheral venous blood was collected after fasting and OGTT, respectively. Plasma selenium, fasting blood glucose, blood lipid (total cholesterol, triglycerides, high density lipoprotein cholesterol, and low density lipoprotein cholesterol) and 2 h OGTT plasma glucose concentration were detected, respectively. The subjects were divided into low, medium and high concentration groups according to the tertiles of plasma selenium concentration in the control group. The multivariate unconditional logistic regression analysis was performed to analyze the association between plasma selenium exposure and IGR. Results: The age (mean±SD) of the case and control group was (53.71±11.38) and (53.95±12.17) years old. The plasma selenium concentration [M (P(25), P(75))] in the case group was 92.81(77.07, 107.05) μg/L, which was significantly higher than the control group [88.73 (77.13, 100.88) μg/L] (P<0.05). The results of multivariate unconditional logistic regression analysis showed that after adjusting for age, sex, BMI, family history of diabetes and hypertension, the risk of IGR was higher in the high-concentration group and the low-concentration group compared with the middle-concentration group, the values of OR (95%CI) were 1.22 (95%CI: 0.94-1.59) and 1.81 (95%CI: 1.42-2.30), respectively. Conclusion: The study suggested a U-shaped association between plasma selenium and IGR.

Promoting access to innovation for frail old persons. IAGG (International Association of Gerontology and Geriatrics), WHO (World Health Organization) and SFGG (Société Française de Gériatrie et de Gérontologie) Workshop--Athens January 20-21, 2012

Frailty tends to be considered as a major risk for adverse outcomes in older persons, but some important aspects remain matter of debate.

OBJECTIVES

The purpose of this paper is to present expert's positions on the main aspects of the frailty syndrome in the older persons.

PARTICIPANTS

Workshop organized by International Association of Gerontology and Geriatrics (IAGG), World Health Organization (WHO) and Société Française de Gériatrie et de Gérontologie (SFGG).

RESULTS

Frailty is widely recognized as an important risk factor for adverse health outcomes in older persons. This can be of particular value in evaluating non-disabled older persons with chronic diseases but today no operational definition has been established. Nutritional status, mobility, activity, strength, endurance, cognition, and mood have been proposed as markers of frailty. Another approach calculates a multidimensional score ranging from "very fit" to "severely frail", but it is difficult to apply into the medical practice. Frailty appears to be secondary to multiple conditions using multiple pathways leading to a vulnerability to a stressor. Biological (inflammation, loss of hormones), clinical (sarcopenia, osteoporosis etc.), as well as social factors (isolation, financial situation) are involved in the vulnerability process. In clinical practice, detection of frailty is of major interest in oncology because of the high prevalence of cancer in older persons and the bad tolerance of the drug therapies. Presence of frailty should also be taken into account in the definition of the cardiovascular risks in the older population. The experts of the workshop have listed the points reached an agreement and those must to be a priority for improving understanding and use of frailty syndrome in practice.

CONCLUSION

Frailty in older adults is a syndrome corresponding to a vulnerability to a stressor. Diagnostic tools have been developed but none can integrate at the same time the large spectrum of factors and the simplicity asked by the clinical practice. An agreement with an international common definition is necessary to develop screening and to reduce the morbidity in older persons.

IAGG workshop: health promotion program on prevention of late onset dementia

IAGG, WHO, and SFGG organized a international workshop on Health promotion programs on prevention of late on-set dementia. Thirty world specialists coming from Europe, North America, Asia, South America, Africa and Australia, shared their experience on methods and results of large epidemiological interventions to reduce incidents of dementia or delay its on-set. Chaired by Laura FRATIGLIONI, an expert in Epidemiological studies on dementia issues, the workshop gave opportunity for discussions and controversies about the state-of-the-art. Based on different national and international trials (ADAPT, MAPT, FINGER, GUDIAGE, GEM etc) the questions remained opened for different aspects of methodology, the choice of domain or multi domain intervention, the choice and the definition of the target populations, the best age of candidates, the issues related to the discrepancy between late effects, and interventions' duration. We are please to publish in the Journal, the presentations presented to this workshop. These publications will complete previously task force published in the journal in the last two years on methodological issues for Alzheimer's trials including end point, biomarkers, and the experience of past therapeutic trials.

The effects of continuous epidural analgesia on Doppler velocimetry of uterine arteries during different periods of labour analgesia

BACKGROUND

The transient effects of epidural bupivacaine 0.25-0.5% on the Doppler velocimetry of umbilical and uterine arteries had been reported, but the effects of continuous lower dose epidural bupivacaine (0.05-0.1%) infusion for labour analgesia have never been reported. In this study, we evaluated the effects of continuous epidural bupivacaine 0.075% on the Doppler velocimetry of uterine arteries.

METHODS

Twenty pregnant women for labour analgesia received continuous epidural bupivacaine 0.075% infusion. We used a 4-MHz continuous-wave Doppler probe (Multigon 500A) with a 200 Hz thump filter to detect uterine blood flow velocity. We recorded the velocimetry data for uterine relaxation and contraction during five time periods: pre-epidural insertion, 1, 2, and 4 h post-epidural infusion, and after delivery of fetus.

RESULTS

Our data showed that the velocimetric indices of uterine vascular resistance were significantly increased 1, 2, and 4 h after epidural infusion when compared with the pre-epidural level; these returned to the baseline after delivery.

CONCLUSION

Continuous epidural analgesia with bupivacaine 0.075% increases the resistance of uterine artery and therefore possibly reduces the uterine blood flow.

Prenatal three-dimensional ultrasound and magnetic resonance imaging evaluation of a fetal oral tumor in preparation for the ex-utero intrapartum treatment (EXIT) procedure

Recent attempts at predelivery management of obstructed fetal airways have focused on the EXIT (ex-utero intrapartum treatment) procedure, which allows sufficient time to secure the fetal airway through preservation of uteroplacental gas exchange. We report a fetus with an exophytic oral tumor noted at 34 weeks of gestation. In this case, three-dimensional (3D) ultrasound allowed a complete and interactive evaluation of the tumor and related facial anatomy, and confirmed that access to the fetal airway was unlikely during delivery. Fetal magnetic resonance imaging (MRI) further demonstrated that the tumor originated in the nasopharynx and obstructed the upper airway. Both imaging results led to a final decision to offer an EXIT procedure for the neonate. At 36 weeks' gestation, a successful EXIT procedure was performed to reduce the risk of respiratory distress immediately after birth. This report highlights the value of 3D ultrasound and MRI as essential prerequisites for optimization of the triage process in selecting EXIT candidates.

Left cervical aortic arch with aneurysm and obstruction: three-dimensional computed tomographic angiography and magnetic resonance angiographic appearance

Cervical arch is a rare congenital anomaly presumed to result from persistence of the third aortic arch and regression of the normal fourth arch. Rather rare is cervical aortic arch associated with aneurysm and obstruction, with eight known cases reported. Definitive diagnosis with a noninvasive imaging modality is desirable and very important to prevent the need for disaster intervention. We present two cases of a pulsatile mass in the left supraclavicular region. Three-dimensional computed tomographic angiography and magnetic resonance angiography clearly showed a left-sided cervical aortic arch (Haughton type D) with arch aneurysm and coarctation (pseudocoarctation).

Differential gene expression in a DNA double-strand-break repair mutant XRS-5 defective in Ku80: analysis by cDNA microarray

The ability of cells to rejoin DNA double-strand breaks (DSBs) usually correlates with their radiosensitivity. This correlation has been demonstrated in radiosensitive cells, including the Chinese hamster ovary mutant XRS-5. XRS-5 is defective in a DNA end-binding protein, Ku80, which is a component of a DNA-dependent protein kinase complex used for joining strand breaks. However, Ku80-deficient cells are known to be retarded in cell proliferation and growth as well as other yet to be identified defects. Using custom-made 600-gene cDNA microarray filters, we found differential gene expressions between the wild-type and XRS-5 cells. Defective Ku80 apparently affects the expression of several repair genes, including topoisomerase-I and -IIA, ERCC5, MLH1, and ATM. In contrast, other DNA repair-associated genes, such as GADD45A, EGR1 MDM2 and p53, were not affected. In addition, for large numbers of growth-associated genes, such as cyclins and clks, the growth factors and cytokines were also affected. Down-regulated expression was also found in several categories of seemingly unrelated genes, including apoptosis, angiogenesis, kinase and signaling, phosphatase, stress protein, proto-oncogenes and tumor suppressors, transcription and translation factors. A RT-PCR analysis confirmed that the XRS-5 cells used were defective in Ku80 expression. The diversified groups of genes being affected could mean that Ku80, a multi-functional DNA-binding protein, not only affects DNA repair, but is also involved in transcription regulation. Our data, taken together, indicate that there are specific genes being modulated in Ku80- deficient cells, and that some of the DNA repair pathways and other biological functions are apparently linked, suggesting that a defect in one gene could have global effects on many other processes.

Colorectal cancer in patients 20 years old or less in Taiwan

BACKGROUND

Colorectal cancer (CRC) is predominantly a disease of the elderly population, but it sometimes occurs in young patients. The diagnosis of CRC in youngsters is often overlooked by physicians or presentation may be delayed.

METHODS

With assistance from the cancer registry center of Taipei Veterans General Hospital, we collected data on all types of colorectal malignancy, including carcinoma, adenocarcinoma, or lymphoma in patients aged 20 or younger. All available medical charts and pathologic specimens were reviewed in detail.

RESULTS

A total of 28 cases were analyzed. The leading presenting symptom was abdominal pain (92%). The locations of the primary tumors were evenly distributed, and the major histologic type was predominantly adenocarcinoma. However, the proportion of mucinous adenocarcinoma was higher than that in the older population. Most of the cases were advanced (11 tumors were classified as Dukes stage C and another 11 as Dukes stage D). The overall 5-year survival rate was 21%.

CONCLUSIONS

Despite the rarity of CRC during the first two decades of life, physicians need to be aware of the possibility and to evaluate suggestive signs and symptoms by colonoscopy or barium enema. Family history of CRC, inflammatory bowel disease, previous polyps, or familial polyposis did not play a crucial role in this group of young patients.

Flow cytometry compared with indirect immunofluorescence for rapid detection of dengue virus type 1 after amplification in tissue culture

Dengue virus (DV) was detected early in infected mosquito C6/36 cells by using indirect immunofluorescence (IF) in conjunction with flow cytometry. Three fixation-permeabilization methods and three DV serotype 1 (DEN-1)-specific monoclonal antibodies, 8-8 (anti-E), 16-4 (anti-NS1), and 15F3-1 (anti-NS1), were evaluated for the detection of DEN-1 in infected C6/36 cells. We found that these three monoclonal antibodies were capable of detecting DV in C6/36 cells as early as 24 h postinoculation by using a conventional indirect IF stain. Both 8-8 and 16-4 detected DV earlier and showed a greater number of DV-positive cells than 15F3-1. In flow cytometry, 3% paraformaldehyde plus 0.1% Triton X-100 with 16-4, the best fixation-permeabilization method for testing DV, showed higher sensitivity (up to 1 PFU) than indirect IF stain. The higher sensitivity of 16-4 in detecting DEN-1 was found with both IF and flow cytometry. Flow cytometry, which had a sensitivity similar to that of nested reverse transcription-PCR, was more sensitive in detecting DV in the infected mosquito cells 10 h earlier than the conventional IF stain. When clinical specimens were amplified in mosquito C6/36 cells and then assayed for DV using flow cytometry and conventional virus isolation at day 7 postinfection, both methods had 97.22% (35 out of 36) agreement. Moreover, among 12 positive samples which were detected by conventional culture method, the flow cytometry assay could detect DV in 58.33% (7 out of 12) of samples even at day 3 postinfection. In conclusion, both monoclonal antibodies 8-8 and 16-4 can be used for the early detection of DEN-1-infected C6/36 cells, with 16-4 (anti-NS1) being the best choice for the rapid diagnosis of DV by both the IF staining and flow cytometry methods.

Salicylates inhibit flavivirus replication independently of blocking nuclear factor kappa B activation

Flaviviruses comprise a positive-sense RNA genome that replicates exclusively in the cytoplasm of infected cells. Whether flaviviruses require an activated nuclear factor(s) to complete their life cycle and trigger apoptosis in infected cells remains elusive. Flavivirus infections quickly activate nuclear factor kappa B (NF-kappaB), and salicylates have been shown to inhibit NF-kappaB activation. In this study, we investigated whether salicylates suppress flavivirus replication and virus-induced apoptosis in cultured cells. In a dose-dependent inhibition, we found salicylates within a range of 1 to 5 mM not only restricted flavivirus replication but also abrogated flavivirus-triggered apoptosis. However, flavivirus replication was not affected by a specific NF-kappaB peptide inhibitor, SN50, and a proteosome inhibitor, lactacystin. Flaviviruses also replicated and triggered apoptosis in cells stably expressing IkappaBalpha-DeltaN, a dominant-negative mutant that antagonizes NF-kappaB activation, as readily as in wild-type BHK-21 cells, suggesting that NF-kappaB activation is not essential for either flavivirus replication or flavivirus-induced apoptosis. Salicylates still diminished flavivirus replication and blocked apoptosis in the same IkappaBalpha-DeltaN cells. This inhibition of flaviviruses by salicylates could be partially reversed by a specific p38 mitogen-activated protein (MAP) kinase inhibitor, SB203580. Together, these results show that the mechanism by which salicylates suppress flavivirus infection may involve p38 MAP kinase activity but is independent of blocking the NF-kappaB pathway.

The effect of human bcl-2 and bcl-X genes on dengue virus-induced apoptosis in cultured cells

Infection of dengue viruses (DENs) can cause human dengue fever, hemorrhagic fever, or shock syndrome. Although DEN-induced apoptosis has been implicated in pathogenesis of the DEN-related diseases, the underlying mechanism remains largely unexplored. In this study, we investigated the effect of ectopic expression of human bcl-2 and bcl-X genes on DEN-induced apoptosis in cultured cells. We employed a human isolate of DEN serotype 2 (DEN-2), PL046, which not only caused cell-cycle arrest in the G1 phase but also induced apoptosis in infected baby hamster kidney (BHK-21) cells, murine neuroblastoma N18 cells, and human neuronal NT-2 cells. Our results reveal that overexpression of bcl-2 in fibroblast-like BHK-21 cells, although not inhibiting virus yields, delayed the process of DEN-induced apoptosis, thereby permitting surviving cells to become persistently infected. In contrast, stable bcl-2 expression in neuronal N18 cells failed to block DEN-induced apoptosis. On the other hand, Bcl-X(L), expressed predominantly in the nervous system, appeared to delay DEN's killing effect in neuronal N18 cells but not in fibroblast-like BHK-21 cells. In addition, inducible expression bcl-X(s), despite its proapoptotic property in other reported system, was found to merely accelerate cell death in DEN-infected N18 but not in infected BHK-21 cells. Thus, through studying the effect of human bcl-2-related genes, our results suggest that DEN infection may trigger target cells to undergo morphologically similar but biochemically distinct apoptotic pathways in a cell-specific manner.

The addition of morphine prolongs fentanyl-bupivacaine spinal analgesia for the relief of labor pain

The combination intrathecal fentanyl (25 microg) and bupivacaine (2.5 mg) provides effective labor analgesia for approximately 90 minutes. The purpose of this prospective, randomized, double-blinded investigation was to determine if the addition of morphine (150 microg) to the intrathecal combination of fentanyl (25 microg) and bupivacaine (2.5 mg) would prolong labor analgesia. By using the combined spinal epidural technique, 95 healthy primiparous laboring women in early labor received 2 mL of one of the two intrathecal study solutions, either FB (n = 48): fentanyl (25 microg) and bupivacaine (2.5 mg); or FBM (n = 47): fentanyl (25 microg) and bupivacaine (2.5 mg) plus morphine (150 microg). The mean duration of labor analgesia was significantly longer in the FBM group than in the FB group (252 +/- 63 min vs 148 +/- 44 min, P < 0.01). There were no significant differences between the two groups regarding the sensory levels, the incidence of nausea, vomiting, pruritus, hypotension, or operative delivery. In conclusion, the addition of 150 microg of morphine to the intrathecal combination of fentanyl plus bupivacaine prolonged the duration of labor analgesia duration without increasing adverse effects.

IMPLICATIONS

The addition of morphine (150 microg) to intrathecal fentanyl (25 microg) and bupivacaine (2.5 mg) prolongs the duration of labor analgesia duration without increasing adverse effects.

Antibody to the nonstructural protein NS1 of Japanese encephalitis virus: potential application of mAb-based indirect ELISA to differentiate infection from vaccination

An indirect enzyme-linked immunosorbent assay (ELISA) was developed to detect and differentiate the antibody responses to Japanese encephalitis (JE) virus nonstructural protein NS1 between infected and vaccinated individuals. The results showed that all convalescent sera from JE patients contained NS1-specific IgG antibodies, while 65 and 40% of these sera showed detectable NS1-specific IgM and IgA antibodies, respectively. Specificity analysis showed that NS1-specific IgM and IgA antibodies from JE patients do not cross-react to dengue virus NS1 glycoprotein, while IgG antibodies from 10% of JE patients showed significant cross-reaction to dengue virus NS1 glycoprotein. To differentiate infection from vaccination, the immune sera from 24 children vaccinated with inactivated JE vaccine were analyzed. The data showed that none of these immune sera had detectable NS1-specific IgG antibodies. The results demonstrated the potential application of JE NS1-specific indirect ELISA to differentiate infection from vaccination.

Ticlopidine-induced hepatitis

Ticlopidine is a commonly prescribed drug in cerebrovascular or cardiovascular diseases. Since the first introduction in 1970's, ticlopidine was shown to be a relatively safe drug. The adverse effects of ticlopidine were mainly bone marrow toxicity and elevation of liver function tests. Ticlopidine-induced hepatitis is rare and only 33 cases were reported in previous English literature. The 33 cases were mostly categorized in cholestatic liver injury; only 2 cases were hepatocellular. In Taiwan, a case of ticlopidine-induced cholestatic hepatitis was ever reported. Herein, we present another rare case of ticlopidine-induced hepatitis in Taiwan with the nature of hepatocellular injury.

Dengue NS1-specific antibody responses: isotype distribution and serotyping in patients with Dengue fever and Dengue hemorrhagic fever

To understand the antibody responses to dengue (DEN) nonstructural 1 (NS1) glycoprotein and their roles in protective immunity or pathogenesis of dengue fever (DF) and dengue hemorrhagic fever (DHF), we have analyzed the NS1-speccific IgM, IgA and IgG antibodies from patients with DF and DHF. An isotype-specific, indirect enzyme-linked immunosorbent assay (ELISA) was established by coating a NS1-specific monoclonal antibody (MAb), D2/8-1, to capture soluble NS1 antigens secreted in the culture supernatants of Vero cells infected with DEN virus. We observed strong anti-NS1 antibody responses in all of the convalescent sera of patients with DF and DHF. Similar NS1-specific isotypic and serotypic antibody responses were found in the sera from DF and DHF patients. The results showed that all DEN infections induced significant NS1-specific IgG, whereas 75% and 60% of primary DF patients vs. 40% and 90% of secondary DF patients produced IgM and IgA antibodies, respectively. Specificity analysis showed that DEN NS1-specific IgG and IgA antibodies cross-react strongly to Japanese encephalitis (JE) virus NS1 glycoprotein, whereas DEN NS1-specific IgM antibodies do not cross-react to JE virus NS1 glycoprotein at all. The serotype specificity of NS1-specific IgM, IgA and IgG were found to be 80%, 67% and 75% for primary infections, and 50%, 22% and 30% for secondary infections in positive samples of DF patients. Similar pattern was found in DHF patients. The results showed that all of the DF and DHF patients produced significant NS1-specific antibodies. We did not observe direct correlation between the anti-NS1 antibody responses and DHF because sera from patients with DF and DHF showed similar anti-NS1 antibody responses.

Esophageal varices in congenital heart disease with total anomalous pulmonary venous connection

Total anomalous pulmonary venous connection (TAPVC) is an uncommon congenital anomaly in which the anatomical presentations vary widely among patients. We hereby present two newborns with TAPVC associated with asplenia syndrome; both had severe esophageal varices due to infradiaphragmatic pulmonary venous drainage. Ultrafast computed tomography (CT) scanning was superior to color Doppler echocardiography and cardiac catheterization as it provided a detailed portrait of the pulmonary drainage. The remarkable radiographic manifestations are presented.

Prophylactic intravenous ondansetron reduces the incidence of intrathecal morphine-induced pruritus in patients undergoing cesarean delivery

Pruritus is a common side effect of intrathecal morphine injection for postoperative pain control. Its incidence is especially high in patients undergoing cesarean delivery. We investigated the effectiveness of ondansetron in preventing intrathecal morphine-induced pruritus in such patients. We included 60 consecutive nonbreastfeeding women who were scheduled for elective cesarean delivery. After the administration of spinal anesthesia with bupivacaine and intrathecal morphine 0.15 mg injection, the patients were randomly divided into three groups. Group 1 received placebo (normal saline) IV injection, Group 2 diphenhydramine 30 mg IV injection, and Group 3 ondansetron 0.1 mg/kg IV injection. The incidence of pruritus was significantly lower in the ondansetron group (25%) when compared with that in the placebo group (85%) and in the diphenhydramine group (80%) (both P < 0.05). The postoperative pain score and time to flatus passage were not significantly different among the three groups. There were no headache or extrapyramidal signs associated with ondansetron use. In conclusion, ondansetron prophylaxis significantly reduced the incidence of intrathecal morphine-induced pruritus in patients undergoing cesarean delivery.

IMPLICATIONS

Ondansetron prophylaxis significantly decreases the incidence of pruritus, a common side effect of intrathecal morphine used to treat postcesarean delivery pain.

Effects of epidural fentanyl on labor pain during the early period of the first stage of induced labor in nulliparous women

BACKGROUND AND PURPOSE

It is generally accepted that epidural injection with local anesthetics and narcotics administered when the cervix has dilated to a diameter exceeding 4 cm can adequately control labor pain. However, many nulliparous women still suffer from labor pain for a few hours prior to the administration of epidural analgesia. This study examined the effectiveness of relief of labor pain obtained by injection of narcotics epidurally once the labor pain begins and the subject requests analgesia.

METHODS

Subjects scheduled for induced labour were divided into three groups: Group A (n = 60) received 5 x 10(-4)% fentanyl (10-20 mL) administered epidurally to relieve early first-stage labor pain. Group B (n = 60) received no analgesic in the early first stage of labor. For groups A and B, when cervical dilatation exceeded 4 cm, 10 to 15 mL of 5 x 10(-2)% bupivacaine and 2 x 10(-4)% fentanyl were injected epidurally and a continuous low dosage was maintained until full dilatation of the cervix resulted. Group C (n = 198) received no analgesic during the entire labor course.

RESULTS

There were no significant differences in the duration of the early period of the first stage of labor, the duration of the late period of the first stage, the duration of the second stage, the Apgar score, or the arterial blood gas of neonates among the three groups. However, group C had a significantly higher cesarean section rate (28.8%) than group A (16.7%) or group B (15%). Pain scores assessed with the Visual Analog Scale (VAS) throughout the entire labor course, were lower in group A than in group B; particularly during the early period of the first stage. The VAS scores in both groups A and B were significantly lower than those in group C during the late period of the first stage of labor.

CONCLUSIONS

The results indicate that once labor pain begins and the subject requests analgesia, epidural injection with fentanyl alone can relieve labor pain during the early period of the first stage. The analgesia does not cause adverse effects to the mothers or neonates. In addition, the labor course and the method of delivery are not affected.

Breast cancer detection using magnetic resonance imaging in breasts injected with liquid silicone

Two patients who had received silicone injections in their breasts several years ago presented with breast complaints. Excluding cancer in these patients was very difficult. Mammograms were very difficult to interpret, as were the physical findings. Carcinoma was successfully detected by magnetic resonance imaging. When women who underwent the injudicious injection of silicone reach the cancer-prone age, the examining physicians should have a greater awareness of the detection and management of carcinoma coexistent with silicone mastopathy. We think that MRI is potentially valuable in the evaluation of the breast lesions; it plays an important role in the detection of breast cancer in breasts augmented with liquid silicone.

Very-high-speed all-optical code-division multiplexing systems using a 2n prime code

We demonstrate experimental all-optical code-division multiplexing (AO-CDM) systems using 64-ps optical pulses and a 2" prime code of n = 3. A distinguishing feature of this experiment is that the modulation of an ultrashort optical clock stream by electrical data is realized without using any optical intensity modulator at each transmitter. Moreover, only low-cost optical 2 x 2 couplers and fiber delay lines are employed to implement all-serial encoders and decoders for a 2n prime code.

Membrane permeabilization by small hydrophobic nonstructural proteins of Japanese encephalitis virus

Infection with Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, may cause acute encephalitis in humans and induce severe cytopathic effects in various types of cultured cells. We observed that JEV replication rendered infected baby hamster kidney (BHK-21) cells sensitive to the translational inhibitor hygromycin B or alpha-sarcine, to which mock-infected cells were insensitive. However, little is known about whether any JEV nonstructural (NS) proteins contribute to virus-induced changes in membrane permeability. Using an inducible Escherichia coli system, we investigated which parts of JEV NS1 to NS4 are capable of modifying membrane penetrability. We found that overexpression of NS2B-NS3, the JEV protease, permeabilized bacterial cells to hygromycin B whereas NS1 expression failed to do so. When expressed separately, NS2B alone, but not NS3, was sufficient to alter bacterial membrane permeability. Similarly, expression of NS4A or NS4B also rendered bacteria susceptible to hygromycin B inhibition. Examination of the effect of NS1 to NS4 expression on bacterial growth rate showed that NS2B exhibited the greatest inhibitory capability, followed by a modest repression from NS2A and NS4A, whereas NS1, NS3, and NS4B had only trivial influence with respect to the vector control. Furthermore, when cotransfected with a reporter gene luciferase or beta-galactosidase, transient expression of NS2A, NS2B, and NS4B markedly reduced the reporter activity in BHK-21 cells. Together, our results suggest that upon JEV infection, these four small hydrophobic NS proteins have various modification effects on host cell membrane permeability, thereby contributing in part to virus-induced cytopathic effects in infected cells.

An evaluation of reachers for use by older persons with disabilities

With the steady growth in numbers of older persons, the number of elders who have impairments impacting on functional performance also increases. Many assistive devices are available that have the potential to help elders with impairments to maintain or regain independence. Reachers offer a good example of an inexpensive and useful assistive device for elders. A needs assessment study of the University at Buffalo Rehabilitation Engineering Research Center on Aging (RERC-Aging) found that 22% of elder owners of reachers were dissatisfied with at least one of the reachers they owned. This study sought to explore the reasons for this dissatisfaction by, first, determining the tasks for which older persons use reachers and, second, testing performance in these tasks with three reachers selected on their potential to most satisfactorily meet the needs of older persons with disabilities. In the first study component, 16 older people were selected randomly from the RERC-Aging study sample pool for telephone interviews. In the second component, 30 elders were selected randomly for an evaluation of reachers. All study participants were 60 years old or older, lived at home, and used one or more reachers in their daily tasks. Consumer criteria for evaluating reachers included adjustable length, one-hand use, life-time guarantee, lock system for grip, forearm support, light weight, and lever action trigger. The Winchester reacher was rated highest by consumers who actually tested three reachers that best met the consumer criteria.

Analysis of the steps involved in Dengue virus entry into host cells

The initial steps of dengue viral entry have been divided into adsorption and penetration using acid glycine treatment to inactivate extracellular virus after attachment to baby hamster kidney (BHK) cells but prior to penetration. First, we showed that virus infection was accomplished within 2 h after adsorption. Second, the assay was used to examine the properties of dengue envelope E protein-specific monoclonal antibodies (MAbs), lectins, and heparin. We found that three MAbs, 17-2, 46-9, and 51-3, may neutralize dengue 2 virus (DEN-2) through inhibition of not only viral attachment but also of penetration. However, one MAb, 56-3.1, interfered specifically with attachment. Therefore, the functional domains of E protein involved in attachment and penetration may be different. Moreover, studies with lectins indicated that carbohydrates, especially alpha-mannose residues, present on the virion glycoproteins may contribute to binding and penetration of the virus into BHK and mosquito C6/36 cells. Finally, virus infectivity was inhibited by heparin through its blocking effects at both virus attachment and penetration. This suggests that cell surface heparan sulfate functions in both viral attachment and penetration of DEN-2 virus. In conclusion, our results further elucidated some aspects of the dengue virus entry process.

Localizations of NS3 and E proteins in mouse brain infected with mutant strain of Japanese encephalitis virus

Infection with a mutant Japanese encephalitis virus (JEV) strain RP-2ms showed reduced neurovirulence than wild type or RP-9 strains after inoculation in BALB/c mice. However, higher intracellular viral titer was detected in Rp-2ms infected cultured cells. Localizations of non-structural 3 (NS3) and envelope (E) proteins were demonstrated by immunocytochemistry. NS3 protein was primarily found in the pyramidal neurons in cerebrum, in the molecular and granular layers of cerebellum. Neither E nor NS3 protein was detected in Purkinje cells of the cerebellum. Immunoelectron microscopic observations showed that E and NS3 proteins were positive in JEV-induced membranous systems, mainly hypertrophic rough endoplasmic reticulum (rER) and membrane vesicle structure (MVS) but not smooth membrane structure. Virus particles were seen in the Golgi apparatus, rER, nuclear envelope, MVS and cytoplasmic vacuoles. Different mechanisms of intracellular trapping in vivo provide a possible basis for attenuation of RP-2ms strains of JEV.

Antiapoptotic but not antiviral function of human bcl-2 assists establishment of Japanese encephalitis virus persistence in cultured cells

Upon infection of Japanese encephalitis virus (JEV), baby hamster kidney (BHK-21) and Chinese hamster ovary (CHO) cells were killed by a mechanism involved in apoptosis. While readily established in a variety of cell lines, JEV persistence has never been successfully instituted in BHK-21 and CHO cells. Since stable expression of human bcl-2 in BHK-21 cells has been shown to delay JEV-induced apoptosis, in this study we investigated whether JEV persistence could be established in such cells. When constitutively expressing bcl-2, but not its closest homolog, bcl-XL, following a primary lytic infection, approximately 5 to 10% of BHK-21 and CHO cells became persistently JEV infected during a long-term culture. From the persistent bulks, several independent clones were selected and expanded to form stable cell lines that continuously produced infectious virus without marked cytopathic effects (CPE). Among these stable cell lines, the truncated nonstructural protein 1 (NS1) was also detected and was indistinguishable from the NS1 truncations previously observed in JEV-persistent murine neuroblastoma N18 cells. However, the stable expression of NS1 alone, regardless of whether it was truncated or full length, failed to render the engineered cells persistently infected by JEV, implying that aberrant NS1 proteins were likely a consequence of, rather than a cause for, the viral persistence. Enforced bcl-2 expression, which did not affect virus replication and spread during the early phase of cytolytic infection, appeared to attain JEV persistence by restriction of virus-induced CPE. Our results suggest that it is the antiapoptotic, rather than the antiviral, effect of cellular bcl-2 which plays a role in the establishment of JEV persistence.

Study of Dengue virus infection in SCID mice engrafted with human K562 cells

Here we report that severe combined immunodeficient (SCID) mice engrafted with human K562 cells (K562-SCID mice) can be used as an animal model to study dengue virus (DEN) infection. After intratumor injection into K562 cell masses of PL046, a Taiwanese DEN-2 human isolate, the K562-SCID mice showed neurological signs of paralysis and died at approximately 2 weeks postinfection. In addition to being detected in the tumor masses, high virus titers were detected in the peripheral blood and the brain tissues, indicating that DEN had replicated in the infected K562-SCID mice. In contrast, the SCID mice were resistant to DEN infection and the mock-infected K562-SCID mice survived for over 3 months. These data illustrate that DEN infection contributed directly to the deaths of the infected K562-SCID mice. Other serotypes of DEN were also used to infect the K562-SCID mice, and the mortality rates of the infected mice varied with different challenge strains, suggesting the existence of diverse degrees of virulence among DENs. To determine whether a neutralizing antibody against DEN in vitro was also protective in vivo, the K562-SCID mice were challenged with DEN-2 and received antibody administration at the same time or 1 day earlier. Our results revealed that the antibody-treated mice exhibited a reduction in mortality and a delay of paralysis onset after DEN infection. In contrast to K562-SCID, the persistently DEN-infected K562 cells generated in vitro invariably failed to be implanted in the mice. It seems that in the early stage of implantation, a gamma interferon activated, nitric oxide-mediated anti-DEN effect might play a role in the innate immunity against DEN-infected cells. The system described herein offers an opportunity to explore DEN replication in vivo and to test various antiviral protocols in infected hosts.

Epidural anesthesia combined with propofol sedation for abdominal hysterectomy in a patient with amyotrophic lateral sclerosis--a case report

Amyotrophic lateral sclerosis (ALS) is a disease characterized by progressive degeneration of the lower motor neurons, motor nuclei of the brain stem, and the descending pathway of the upper motor neurons. As the disease progresses, atrophy and weakness involve most of the skeletal muscles, including those of the tongue, pharynx larynx and chest. Impairment of respiration, altered response to muscle relaxants, and predisposition of aspiration affect a safe anesthetic management. General anesthesia with tracheal intubation might ensure intraoperative ventilatory management, but it could also increase the risk of aspiration with its entailing airway obstruction and demand the need of postoperative artificial ventilatory support. In this report, we described the use of epidural analgesia with 2% lidocaine combined with continuous infusion of low dose propofol for sedation for a ALS patient undergoing abdominal hysterectomy. The anesthetic management of this patient was smooth and successful. Besides, epidural morphine could provide excellent postoperative pain relief without respiratory complications.

Effects of ondansetron on postoperative emesis in Chinese children

BACKGROUND

Postoperative nausea together with vomiting (PONV) is a common adverse effect of general anesthesia. Ondansetron, a new serotonin (5-hydroxytryptamine) receptor antagonist of the subtype 3 is shown to be effective and safe in the prophylaxis and treatment of PONV. However, the clinical experiences of using ondansetron for prevention of PONV is lacking in Taiwan. The purpose of this study is to evaluate the efficacy and safety of ondansetron for prevention of PONV in Chinese children.

METHODS

Eighty pediatric patients aged from 2 to 12 years undergoing herinorrhaphy were prospectively randomized to receive either ondansetron 0.1 mg/kg or saline placebo. All patients received general anesthesia with tracheal intubation. The parents of patients were educated how to record the episodes of postoperative emesis and other complications and answer questions in the form of questionnaire. The observation period lasted for 24 h postoperatively.

RESULTS

The incidence of postoperative emesis was 55% and 10% in placebo and ondansetron group respectively. As to the severity of emetic symptoms it was milder in the ondansetron group. There was no difference in the incidence of other complications between the two groups.

CONCLUSIONS

The intravenous administration of ondansetron 0.1 mg/kg is safe and effective in reducing postoperative emesis in Chinese children undergoing herinorrhaphy surgery.

Fibrolamellar hepatocellular carcinoma--an atypical MR manifestation

We report the imaging findings, specifically magnetic resonance pictures of a non-cirrhotic case of fibrolamellar hepatocellular carcinoma in an older patient (60 years). Computed tomography revealed non-enhanced hypodense central scar without notable intratumoral calcification. MR imaging revealed a mass, which was homogeneously hypointense on T1-weighted images (T1WI) and turned hyperintense on T2-weighted images (T2WI). Stellate central scar was depicted with more hypointensity on T1WI, however, it became markedly hyperintense on T2WI. This manifestation is very different from the typical pattern reported in the literature. In gadolinium enhanced T1WI, the mass other than the central scar got enhanced. Fibronodular hyperplasia and fibrolamellar hepatocellular carcinoma should be differentiated with reference to the clinical and imaging findings. Collagenous central scar was described pathologically within the latter. However, a discrepancy between the pathological and magnetic resonance pattern concerning the central scar which was collagenous and corresponding to hyperintensity on T2WI was found. To our knowledge no similar entity has been described in the literatures so far.

DNA immunization with Japanese encephalitis virus nonstructural protein NS1 elicits protective immunity in mice

Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, is a zoonotic pathogen that is prevalent in some Southeast Asian countries and causes acute encephalitis in humans. To evaluate the potential application of gene immunization to JEV infection, we characterized the immune responses from mice intramuscularly injected with plasmid DNA encoding JEV glycoproteins, including the precursor membrane (prM) plus envelope (E) proteins and the nonstructural protein NS1. When injected with the plasmid expressing prM plus E, 70% of the immunized mice survived after a lethal JEV challenge, whereas when immunized with the plasmid expressing NS1, 90% of the mice survived after a lethal challenge. As a control, the mice immunized with the DNA vector pcDNA3 showed a low level (40%) of protection, suggesting a nonspecific adjuvant effect of the plasmid DNA. Despite having no detectable neutralizing activity, the NS1 immunization elicited a strong antibody response exhibiting cytolytic activity against JEV-infected cells in a complement-dependent manner. By contrast, immunization with a construct expressing a longer NS1 protein (NS1'), containing an extra 60-amino-acid portion from the N terminus of NS2A, failed to protect mice against a lethal challenge. Biochemical analyses revealed that when individually expressed, NS1 but not NS1' could be readily secreted as a homodimer in large quantity and could also be efficiently expressed on the cell surface. Interestingly, when NS1 and NS1' coexisted in cells, the level of NS1 cell surface expression was much lower than that in cells expressing NS1 alone. These data imply that the presence of partial NS2A might have a negative influence on an NS1-based DNA vaccine. The results herein clearly illustrate that immunization with DNA expressing NS1 alone is sufficient to protect mice against a lethal JEV challenge.

Ultrastructure and localization of E proteins in cultured neuron cells infected with Japanese encephalitis virus

A unique structure and in situ localization of E proteins were demonstrated in cultured neurons infected with neurovirulent and aneurovirulent strains of local Japanese encephalitis virus (JEV). Dilated rough endoplasmic reticulum (rER) containing smooth membrane structures (SMS) was continuous with the outer membrane of the nuclear envelope. These membranes were found to be connected to unique dense bodies, membrane vesicle structures (MVS). The de novo formation of SMS, annulate lamellae, and the appearance of MVS indicated proliferation of the membranous system in response to JEV infection. E proteins were possibly assembled in the virions in the nuclear envelope or rER or on the plasma membrane. The interconnections between MVS, rER, and the nuclear envelope and immunogold labeling of E proteins on the MVS provided strong evidence that MVS serve as a reservoir of JEV components during virus assembly.

Transplantation of microencapsulated PC12 cells provides long-term improvement of dopaminergic functions

The purpose of this study is to examine if microencapsulated PC12 cells may provide long term effects to the hemiparkinsonian rats. A modified technique was used to encapsulate PC12 cells into gelled microspheres. We found that the PC12 cells can survive in the modified microcapsules in vitro. Most of the PC12 cells formed cluster 3 weeks after incubation. The PC12 cell-loaded microcapsules were also examined in vitro. Adult Sprague-Dawley rats, anesthetized with chloral hydrate, were injected unilaterally with 6-hydroxydopamine into the medial forebrain bundle. The effectiveness of this lesion was tested by measuring apomorphine or methamphetamine-induced rotation one month after lesioning. The unilaterally lesioned rats were transplanted with microencapsulated PC12 cells. Results showed that apomorphine and methamphetamine-induced rotations were greatly suppressed after transplantation. One year after the grafting, the animals were anesthetized with urethane for the voltammetric study. Low dose of KCl was directly injected into the grafted striatum through pressure microejection. We found that KCl-induced DA release, as measured by voltammetric techniques, was regenerated in the striatum. The animals were later sacrificed for histological examination. We found that capsules were present in the lesioned striatum one year after grafting. Most of the capsules contained no PC12 cell. However, some capsules were filled entirely with PC12 cells. Taken together, our data suggested that PC12 cells can survive in the capsule in vitro and may provide long-term dopaminergic effects to the hemiparkinsonian rats.

Effect of enforced expression of human bcl-2 on Japanese encephalitis virus-induced apoptosis in cultured cells

Infection by Japanese encephalitis virus (JEV), a mosquito-borne flavivirus, causes acute encephalitis in humans and induces severe cytopathic effects in different types of cultured cells. This study attempted to determine whether apoptosis contributes to virus-induced cell death in a culture system by characterizing JEV lytic infection in baby hamster kidney BHK-21 cells, murine neuroblastoma N18 cells, and human neuronal progenitor NT2 cells. According to our results, the replication of JEV, and not the UV-inactivated virions per se, triggered apoptosis in these cell lines, as evidenced by nuclear condensation, DNA fragmentation ladder, and in situ end labeling of DNA strand breaks with terminal transferase (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling assay). Different strains of JEV, regardless of whether they are neurovirulent to mice, could induce apoptosis of the infected cells. In addition, enforced expression of the human protooncogene bcl-2 in BHK-21 cells, which did not influence virus production, appeared to delay the process of JEV-induced apoptosis, despite the fact that most infected cells were inevitably killed after prolonged cultures. However, Bcl-2 proteins expressed in N18 cells failed to block JEV-induced apoptosis, although they did prevent Sindbis virus-induced apoptosis from occurring in the same cells. This finding suggests that these two viruses may utilize similar but not identical mechanisms to kill their infected cells. The results presented here thus demonstrate that apoptosis can be a general mechanism for JEV-induced cell death and that enforced bcl-2 expression may be inadequate in protecting all cell types from JEV-induced apoptosis in cell cultures.

Inhibition of Japanese encephalitis virus infection by nitric oxide: antiviral effect of nitric oxide on RNA virus replication

The antiviral effects of nitric oxide (NO) on Japanese encephalitis virus (JEV), a member of the family Flaviviridae, were investigated in this study. In vitro, inhibition of replication of JEV in gamma interferon-activated RAW 264.7 murine macrophages was correlated to cellular NO production. When cocultured with infected murine neuroblastoma N18 cells, gamma interferon-activated RAW 264.7 cells also efficiently hindered JEV replication in contiguous bystanders, and this anti-JEV effect could be reversed by an NO synthase (NOS) inhibitor, N-monomethyl-L-arginine acetate. In vivo, the mortality rate increased as the NOS activity of JEV-infected mice was inhibited by its competitive inhibitor, N-nitro-L-arginine methyl ester. Moreover, when an organic donor, S-nitro-N-acetylpenicillamine (SNAP), was used, the NO-mediated antiviral effect was also observed in primarily JEV-infected N18, human neuronal NT-2, and BHK-21 cells, as well as in persistently JEV-infected C2-2 cells. These data reaffirm that NO has an effective and broad-spectrum antimicrobial activity against diversified intracellular pathogens. Interestingly, the antiviral effect of NO was not enhanced by treatment of N18 cells with SNAP prior to JEV infection, a measure which has been shown to greatly increase the antiviral effect of NO in infection by vesicular stomatitis virus. From biochemical analysis of the impact of NO on JEV replication in cell culture, NO was found to profoundly inhibit viral RNA synthesis, viral protein accumulation, and virus release from infected cells. The results herein thus suggest that NO may play a crucial role in the innate immunity of the host to restrict the initial stage of JEV infection in the central nervous system.

Generation and characterization of organ-tropism mutants of Japanese encephalitis virus in vivo and in vitro

Using gamma-ray irradiation, a pair of virulent (RP-9) and attenuated (RP-2ms) variants of Japanese encephalitis virus (JEV) were generated from a Taiwanese isolate, NT109. The two variants differed in plaque morphology, virus adsorption, and growth properties in BHK-21 cells: (i) RP-2ms produced smaller plaques than RP-9; (ii) RP-2ms adsorbed less efficiently to host cells but yielded a higher virus titer (burst size); and (iii) RP-2ms virions were mostly accumulated intracellularly, whereas RP-9 was released extracellularly. In addition, in an in vitro binding assay, the envelope (E) protein of RP-9, but not that of RP-2ms, bound specifically to a cellular protein of 57-kDa derived from BHK-21 cells. When injected into mice intracerebrally, RP-2ms was much less virulent than RP-9, with 50% lethal doses of > 10(7) and 0.4 plaque forming units, respectively. Moreover, when inoculated intraperitoneally, their organ tropism differed in that the main target organ for RP-2ms was liver, whereas that for RP-9 was brain. These results suggest that RP-2ms was less neurovirulent and less neuroinvasive from peripheral routes. Molecular analysis of the virus structural proteins detected only two differences between RP-9 and RP-2ms: one in E protein, Glu-138 in RP-9 and Lys-138 in RP-2ms, and the other in prM, Tyr-43 in RP-9 and His-43 in RP-2ms. Since the N-terminal 92 amino acids of prM are cleaved and not present in mature JEV virions, the single-amino-acid change of the E protein at position 138 may account for the difference between the mutants in the in vitro binding assay. Such mutation in E protein, or perhaps in conjunction with the prM mutation, may be responsible, in part, for the phenotypic differences observed in vitro and in vivo between the two mutants.

Perioperative alterations of the thromboelastography in patients receiving one-stage bilateral total knee arthroplasty

BACKGROUND

Total knee arthroplasty is associated with activation of coagulation and fibrinolytic system in the perioperative period. The coagulation and fibrinolytic activation in one-stage bilateral total knee arthroplasty has not been described before. Thromboelastography is a real-time aid in the monitoring of coagulation and is clinically valuable in the evaluation of whole blood hemostasis. We evaluated the coagulation and fibrinolysis system activation during and after one-stage bilateral total knee arthroplasty by thromboelastography.

METHODS

Twenty patients, ASA class I-II, undergoing one stage bilateral total knee arthroplasty were included in this study. All patients received continuous spinal anesthesia with isobaric 0.2% bupivacaine. Arterial blood samples were obtained for thromboelastography in the following sequences (1) after induction of anesthesia (baseline), (2) 20 min after releasing tourniquet of the first leg (3) 20 min after releasing tourniquet of the second leg, (4) 2 h postoperatively, (5) 24 h postoperatively.

RESULTS

There was a significant shortening of reaction time (R value) after deflation of the first leg tourniquet, and a further decrease of R value after deflation of the second leg tourniquet and two hours postoperatively. The perioperative change of coagulation time was similar to that of R value. The maximum amplitude decreased after releasing tourniquet of the second leg and two hours postoperatively.

CONCLUSION

The activation of coagulation, as monitored by thromboelastography, is predominant in one-stage bilateral total knee arthroplasty after releasing tourniquet of the second leg and returns to baseline 24 h postoperatively.

A highly attenuated strain of Japanese encephalitis virus induces a protective immune response in mice

A pair of virulent (RP-9) and attenuated (RP-2ms) mutants of Japanese encephalitis virus (JEV) were generated from a Taiwanese isolate NT109. The mutants differed in several aspects in vitro and in vivo. RP-2ms exhibited smaller plaque than RP-9 on BHK-21 cells, and when intracerebrally injected, RP-2ms was much less neurovirulent than RP-9. As peripherally inoculated, RP-2ms lost neuroinvasiveness while RP-9 penetrated blood-brain barrier, replicated in mouse brain, and killed all the mice. Single RP-2ms immunization completely protected C3H and ICR mice from a lethal challenge with RP-9; the sera from such mice contained antibodies against JEV envelope and nonstructural 1 proteins, indicating RP-2ms had replicated in the mice Neutralizing activity against NT109 in such sera was further demonstrated by plaque reduction neutralization test. In addition, significant lymphoproliferation was detected in spleen cells from the RP-2ms-immunized mice, and cytotoxic activity in these cells specific for the MHC-matched, JEV-infected cells, but not mock cells, was also observed. Altogether, these results demonstrate that RP-2ms, a highly attenuated JEV strain, can induce a protective immunity in mice.

Identification of immunodominant, group-specific and subcomplex-specific, continuous epitopes in the core regions of Japanese encephalitis virus using synthetic peptides

Two flaviviruses, Japanese encephalitis (JE) virus and Dengue (DEN) virus which have high pathogenicity for humans, continue to pose a serious public health problem in tropical and subtropical countries of the world. In order to identify the immunodominant B-cell epitopes for diagnostic application, we have prepared a series of 15-mer synthetic peptides from JE virus core protein based on computer analysis. Four linear, immunodominant epitopes corresponding to amino acids 91-105 (P78), 1-15 (P73), 8-22 (P74), and 34-48 (P75) of JE virus core proteins were identified by employing an enzyme-linked immunosorbent assay (ELISA), using high-titered immune sera from JE-vaccinated children. P78 was found to be the most immunodominant. The sero-specificity of these peptides was tested by binding to seroconverted samples from JE and DEN-1 patients. P78 and P74 belonged to group-specific epitopes which reacted with both JE and DEN-1 patient sera. P73 and P75 belonged to subcomplex-specific epitopes which reacted only with JE but not with DEN-1 patient sera. The study suggests that these peptides corresponding to the immunodominant epitopes of JE virus core protein might have the potential to be used as peptide-based diagnostic reagents for the detection and differentiation of JE and DEN antibody responses.

Persistence of Japanese encephalitis virus is associated with abnormal expression of the nonstructural protein NS1 in host cells

Persistent infection with Japanese encephalitis virus (JEV) was established in murine neuroblastoma N18 cells, and the persistency has been maintained in cell culture for over 6 months. From the persistently infected cells, a clone named C2-2 was selected and expanded to form a stable cell line. The vast majority of C2-2 cells showed viral protein staining by immunofluorescence and continuously produced low levels of virus (10(3) to 10(4) PFU/ml) without marked cytopathic effects or cyclic variations. In addition to the wild-type viral proteins, truncated forms of the viral nonstructural protein 1 (NS1) as well as its derivative NS1' were produced in C2-2 cells. Both truncated NS1 and NS1' contain deletions at their N-termini; however, the analyses by RT-PCR and direct sequencing of the viral RNA failed to detect any truncations or mutations within the NS1 region, suggesting that NS1 truncation was a result of a unique posttranslational proteolytic cleavage of NS1 in the persistently infected cells. Similar but not identical truncation of NS1 was also observed in two other persistently infected cell lines established in Vero and DBT (murine astrocytoma) cells. However, viruses released from C2-2 cells did not produce truncated NS1 upon infection of N18 cells, suggesting that NS1 truncations were the result of virus-cell interaction in persistently infected cells. These data indicate a strong association between abnormal NS1 expression and JEV persistency. A probable involvement of dysfunctional NS1 in the establishment and/or maintenance of JEV persistency in tissue culture is discussed.

Long-term propofol infusion and airway management in a patient with Goldenhar's syndrome

A 2-year-old patient of Goldenhar's syndrome received an operation for corneal transplantation. Difficult endotracheal intubation from the congenital anomaly was treated with laryngeal mask airway and pediatric fiberoptic laryngoscope. Long-term propofol infusion (> 10 h) for anaesthetic maintenance in this small child was used with rapid and smooth recovery.

Generation and characterization of Japanese encephalitis virus specific monoclonal antibodies

Monoclonal antibodies (MoAbs) specifically against Japanese encephalitis virus (JEV) were generated by fusion of immunized mouse spleen cells with NS-1 myeloma cells. Nakayama-NIH (Na) and three Taiwan local strains of JEV, i.e., TL isolated from a patient's brain in 1965, NT109 (JE7) isolated from Cx. tritaeniorhynchus in 1985, and RP9, a plaque purified clone of NT109, were used in the immunization. The specificities of moAbs were determined by immunoprecipitation and western blotting, using JEV-infected cell lysates. They were confirmed by the same methods using recombinant JEV proteins as antigens. From Na immunization, 4 anti-E, 3 anti-NS1 and 3 anti-NS3 moAbs were generated. Seventeen anti-E, three anti-NS1 and three anti-NS3 specific moAbs were generated from mice immunized with Taiwan local JEV strains. Overall 21 anti-E, 6 anti-NS1, and 6 anti-NS3 moAbs were produced and characterized. The isotypes of these moAbs were also determined and described. Interestingly, a majority of the moAbs generated for RP9 were IgG1 isotype. In conclusion, 33 moAbs specific to JEV were generated and characterized, and some of these anti-JEV moAbs were made against Taiwan local isolates. These moAbs provide a powerful tool to study JEV, especially the antigenic properties of Taiwan's local strains.

Acid extrusion in S3 segment of rabbit proximal tubule. I. Effect of bilateral CO2/HCO3-

Monitoring the absorbance spectra of the pH-sensitive dye dimethylcarboxyfluorescein, we studied intracellular pH (pHi) regulation in the isolated perfused S3 segment of rabbit proximal tubule. To explain a previous observation, that steady-state pHi is higher in the presence than in the absence of CO2/HCO3- (N. L. Nakhoul, L. K. Chen, and W. F. Boron. J. Gen. Physiol. 102: 1171-1205, 1993), we examined the effect of bilateral (i.e., luminal and basolateral) CO2/HCO3- on the acid extrusion processes responsible for recovery of pHi from acid loads. To compute fluxes from rates of pHi change, we determined the pHi dependence of intrinsic intracellular buffering power, which was approximately 50 mM/pH at pHi 6.5 and fell linearly to approximately 20 mM at pHi 7.4. In one series of experiments, we monitored the rate of pHi recovery from an acid load imposed by an NH4+/NH3 prepulse. Over a broad range of pHi values, total net acid extrusion was approximately four times higher in bilateral presence of CO2/HCO3- than in its absence. In a second group of experiments, which were designed to determine the effect of CO2/HCO3- on luminal Na+/H+ exchange, we monitored the rate of pHi recovery elicited by adding Na+ back to only the lumen, after first removing Na+ bilaterally. Initial rate of luminal Na(+)-dependent net acid extrusion in presence of CO2/HCO3- was approximately 229 microM/s (pHi 6.92), approximately 1.8 times higher than the flux of approximately 127 microM/s (P < 0.005) obtained in absence of CO2/HCO3- (pHi 6.66). CO2/HCO3- alkali-shifted the flux vs. pHi relationship by 0.3-0.4 pH units. In a final series of experiments, we examined the effect of CO2/HCO3- on the Na(+)-independent alkalinization that follows the rapid, initial acidification elicited by bilateral Na+ removal. In the presence of CO2/HCO3-, lag time for initiation of the Na(+)-independent alkalinization was only approximately 36 vs. approximately 211 s (P < 0.002) in absence of CO2/HCO3-. Also, Na(+)-independent net acid extrusion rate was approximately two to three times higher in presence than in absence of CO2/HCO3- at comparable pHi. This Na(+)-independent acid extrusion was insensitive to N-ethylmaleimide (2 mM), but was inhibited approximately 94% by efforts to deplete intracellular ATP (i.e., removal of glucose and amino acids, plus addition of 2 mM cyanide and 10 mM iodoacetic acid). Stimulation of luminal Na+/H+ exchange and Na(+)-independent acid extrusion appears to be the major, if not the entire, explanation for the higher steady-state pHi caused by bilateral addition of CO2/HCO3-.

Acid extrusion in S3 segment of rabbit proximal tubule. II. Effect of basolateral CO2/HCO3-

Monitoring intracellular absorbance spectra of the pH-sensitive dye dimethylcarboxyfluorescein we studied intracellular pH (pHi) regulation in the isolated perfused S3 segment of the rabbit proximal tubule. In the preceding study [Am. J. Physiol. 268 (Renal Fluid Electrolyte Physiol. 37): F179-F192, 1995.], we demonstrated that simultaneously adding CO2/HCO3- to both lumen and bath stimulated two acid-extruding mechanisms, one dependent on luminal Na+ (a Na+/H+ exchanger) and one independent of Na+ (presumably a H+ pump). Here, we examine the effects of adding CO2/HCO3- to the lumen only or to the bath only. Over a broad pHi range, the total rate of pHi recovery from an acid load in the presence of Na+ was not increased by luminal CO2/HCO3-. On the other hand, basolateral CO2/HCO3- increased the pHi recovery rate to an even greater extent than had bilateral CO2/HCO3-. Regarding the Na(+)-independent pHi recovery mechanism, we found that luminal CO2/HCO3- failed to increase the pHi recovery rate compared with controls also studied in the absence of Na+. Neither did luminal CO2/HCO3- significantly affect the lag time between the maximal acid load and the initiation of the Na(+)-independent pHi recovery (approximately 147 vs. approximately 212 s in controls). On the other hand, adding CO2/HCO3- to only the bath substantially increased the rate of Na(+)-independent pHi recovery, which generally was greater than that observed with bilateral CO2/HCO3-. CO2/HCO3- only in the bath also reduced the lag time to approximately 51 s, which is not significantly different from the value of approximately 36 s observed with bilateral CO2/HCO3-. Our data are consistent with the hypothesis that basolateral (but not luminal) CO2/HCO3- stimulates both a luminal Na+/H+ exchanger and a luminal H+ pump.

Effect of basolateral CO2/HCO3- on intracellular pH regulation in the rabbit S3 proximal tubule

We used the absorbance spectrum of the pH-sensitive dye dimethylcarboxyfluorescein to monitor intracellular pH (pHi) in the isolated perfused S3 segment of the rabbit proximal tubule, and examined the effect on pHi of switching from a HEPES to a CO2/HCO3- buffer in the lumen and/or the bath (i.e., basolateral solution). Solutions were titrated to pH 7.40 at 37 degrees C. With 10 mM acetate present bilaterally (lumen and bath), this causing steady-state pHi to be rather high (approximately 7.45), bilaterally switching the buffer from 32 mM HEPES to 5% CO2/25 mM HCO3- caused a sustained fall in pHi of approximately 0.26. However, with acetate absent bilaterally, this causing steady-state pHi to be substantially lower (approximately 6.9), bilaterally switching to CO2/HCO3- caused a transient pHi fall (due to the influx of CO2), followed by a sustained rise to a level approximately 0.18 higher than the initial one. The remainder of the experiments was devoted to examining this alkalinization in the absence of acetate. Switching to CO2/HCO3- only in the lumen caused a sustained pHi fall of approximately 0.15, whereas switching to CO2/HCO3- only in the bath caused a transient fall followed by a sustained pHi increase to approximately 0.26 above the initial value. This basolateral CO2/HCO3(-)-induced alkalinization was not inhibited by 50 microM DIDS applied shortly after CO2/HCO3- washout, but was slowed approximately 73% by DIDS applied more than 30 min after CO2/HCO3- washout. The rate was unaffected by 100 microM bilateral acetazolamide, although this drug greatly reduced CO2-induced pHi transients. The alkalinization was not blocked by bilateral removal of Na+ per se, but was abolished at pHi values below approximately 6.5. The alkalinization was also unaffected by short-term bilateral removal of Cl- or SO4=. Basolateral CO2/HCO3- elicited the usual pHi increase even when all solutes were replaced, short or long-term (> 45 min), by N-methyl-D-glucammonium/glucuronate (NMDG+/Glr-). Luminal CO2/HCO3- did not elicit a pHi increase in NMDG+/Glr-. Although the sustained pHi increase elicited by basolateral CO2/HCO3- could be due to a basolateral HCO3- uptake mechanism, net reabsorption of HCO3- by the S3 segment, as well as our ACZ data, suggest instead that basolateral CO2/HCO3- elicits the sustained pHi increase either by inhibiting an acid-loading process or stimulating acid extrusion across the luminal membrane (e.g., via an H+ pump).