Development of the first PCR for detection of Psoroptes ovis var. cuniculi infection and its comparison to microscopic examination and serological assay in rabbits

Psoroptes mites are the common ecto-parasites of wild and domestic animals worldwide, which causes considerable economic losses in livestock industry. Microscopy is deemed to be the 'gold standard' for the diagnosis of Psoroptes mite infection but it has poor sensitivity for low mite infections and/or sub-clinical infections. To overcome these shortcomings, we screened four genes to develop a sensitive and specific PCR for the detection of Psoroptes mite infection in rabbits, and confirmed its practicability in detecting early infection and monitoring treatment outcome with traditional microscopy and serological tests. Results showed that PCR assay targeting ITS2 (ITS2-PCR) had a high specificity and sensitivity (detection limit: 40.3 pg/μL DNA) for detecting P. ovis DNA. In rabbits artificially infected with P. ovis, all three diagnostic tests showed the same detection rate from 14 days post infection (dpi) to 42 days dpi. However, these diagnostic tests behave differently at 7 dpi and after treatment: at 7 dpi, the detection rate of ITS2-PCR was higher than rPsoSP3-based iELISA and traditional microscopy (ITS2-PCR: 88.9%, rPsoSP3-iELISA: 77.7%, microscopy: 33.3%); at 7 days post treatment (dpt), positivity rates of ITS2-PCR and microscopy rapidly decreased to 0.00% and 11.1%, whereas rPsoSP3-iELISA remained 100% positive rate. Furthermore, the comprehensive comparisons of diagnostic performance and features of three diagnostic tests at 7 dpi were performed. Compared to ITS2-PCR or rPsoSP3-iELISA, microscopy had the lowest sensitivity, and the agreement between these assays was low (κ < 0.3). Field study showed that ITS2-PCR showed a higher detection rate than microscopy (19.4% and 11.1%, respectively). Our results suggested that the ITS2-PCR developed in this study provided a new laboratory tool for diagnosis of P. ovis var. cuniculi infection, and it had advantages over microscopic examination in detection low-level mite infections and serological assay in monitoring treatment outcome.

[The potential effect mechanism and research progress of extreme temperature exposure on asthma attacks]

Asthma is one of the common chronic respiratory diseases, and its incidence has been increasing worldwide in recent years. In the context of climate change, the frequency and intensity of extreme weather events are increasing. A large body of evidence suggests that exposure to extreme temperatures can increase the risk of asthma attacks, but the underlying mechanisms that trigger asthma attacks are still unclear. This study aims to systematically review the research progress on the association between extreme temperature and asthma attacks, and to elucidate the synergistic effects of extreme temperatures, indoor/outdoor environments, and individual vulnerabilities on asthma attacks. Additionally, this review discusses the potential mechanisms of asthma attacks triggered by extreme temperature, and highlights the important role of immune regulation and neuroregulation in the inflammatory response of asthma induced by extreme temperature. Moreover, we propose a potential mechanism framework to explain the disease pathogenesis of asthma which is induced by the interactions between extreme temperature and environmental factors, in order to provide a scientific basis for addressing the adverse impacts of extreme weather events and climate change.

[Impact of additional time spent for vaccination services on overall satisfaction rate in parents]

Objective: To understand the overall satisfaction rate with vaccination services in parents of children, and the impact of additional time consumed for vaccination service on overall satisfaction rate. Methods: From December 2019 to January 2020, a total of 3 178 parents of 0-3 years old children were investigated to collect the information about their basic characteristics, additional time spent for vaccination service and overall satisfaction through questionnaires. Binary logistic regression model and restricted cubic spline model were used to evaluate the impact of additional time spend on the overall satisfaction rate. Results: The overall satisfaction rate of parents with vaccination services was 92.32%. The median time for parents to move from home to vaccination clinic was 10.00 (10.00, 20.00) minutes, the median waiting time to make an appointment was 10.00 (5.00, 15.00) minutes, the median waiting time for vaccination was 5.00 (3.00, 10.00) minutes, and the median total additional time spent was 30.00 (20.00, 45.00) minutes. The binary logistic regression analysis showed that after adjusting the relevant factors, the main factors affecting the overall satisfaction rate were the waiting time for making an appointment (the 4- minutes group vs. 8- minutes group: OR=1.863, 95%CI: 1.307-2.657), waiting time for vaccination (the <4 minutes group vs. 8- minutes group: OR=1.529, 95%CI: 1.102-2.120; the 4- minutes group vs. 8- minutes group: OR=1.534, 95%CI: 1.104-2.130), total additional time spent (the 15- minutes group vs. 30- minutes group: OR=1.470, 95%CI: 1.094-1.976). Restricted cubic spline analysis showed that the waiting time for making an appointment (non-linear: χ²=13.18, P=0.001), the waiting time for vaccination (non-linear: χ²=13.50, P=0.001), and the total additional time consumed (non-linear: χ²=9.38, P=0.009) showed a non-linear inverted "V" dose response relationship to the overall satisfaction of vaccination services. Conclusions: The waiting time for parents to make an appointment, the waiting time for vaccination and the total additional time spent for receiving vaccination services affected the overall satisfaction rate of the vaccination services. And the waiting time for making an appointment was the most important factor, and it is necessary to shorten the waiting time for appointment. It is suggested that the vaccination clinic should make use of information technology (such as WeChat public account, APP) to make accurate appointments, make appointments to the time period to control the number of people within time period.

[The association between apparent temperature and hand, foot, and mouth disease and its spatial heterogeneity in Guangdong, Anhui and Jilin provinces]

Objective: To study the association between apparent temperature (AT) and the incidence of hand,foot, and mouth disease (HFMD) and its spatial heterogeneity in 46 cities in Guangdong, Anhui and Jilin provinces, and provide scientific evidence for the early warning of HFMD. Methods: The data of HFMD incidence and meteorological factors from 2009 to 2018 in Guangdong province, 2009 to 2015 in Anhui province, and 2013 to 2018 in Jilin province were collected. Distributed lag non-linear models were constructed to investigate the association between AT and the incidence of HFMD in 46 cities from three provinces in China. Meta-analysis was used to pool the city-specific estimates, and Meta-regression was applied to analyze the factors that may cause spatial heterogeneity. Results: The relationship between daily AT and the incidence of HFMD in 46 cities appeared nonlinear. The association in Guangdong was similar to that in Jilin, and the risk of HFMD increased with the increase of AT. While the risk of HFMD in Anhui first increased with the increase of AT, and peaked at 18.1 ℃ and then went down. AT on different levels showed different lag impacts and the higher AT showed greater and longer lag impact. The spatial heterogeneity of associations may have been caused by latitude, longitude, average temperature, and average sunshine hours. Conclusions: AT is a comprehensive index to evaluate the association between temperature, relative humidity and wind speed and the incidence of HFMD. Higher AT may increase the risk of HFMD. The AT and HFMD relationship across spatial heterogeneity varies depending on geographic location and meteorological conditions.

5-Aminolevulinic acid ameliorates cadmium-induced morphological, biochemical, and ultrastructural changes in seedlings of oilseed rape

Due to its prolific growth, oilseed rape (Brassica napus L.) can be grown successfully for phytoremediation of cadmium (Cd)-contaminated soils. Nowadays, use of plant growth regulators against heavy metals stress is one of the major objectives of researchers. The present study evaluates the ameliorate effects of 5-aminolevulinic acid (ALA, 0, 0.4, 2, and 10 mg/l) on the growth of oilseed rape (B. napus L. cv. ZS 758) seedlings under Cd stress (0, 100, and 500 μM). Results have shown that Cd stress hampered the seedling growth by decreasing the radical and hypocotyls length, shoot and root biomass, chlorophyll content, and antioxidants enzymes. On the other hand, Cd stress increased the level of malondialdehyde (MDA) and production of H2O2 and accumulation of Cd in the shoots. The microscopic study of leaf mesophyll cells showed that toxicity of Cd totally destroyed the whole cell structure, and accumulation of Cd also appeared in micrographs. Application of ALA at lower dosage (2 mg/l) enhanced the seedling growth and biomass. The results showed that 2 mg/l ALA significantly improved chlorophyll content under Cd stress and decreased the level of Cd contents in shoots. Application of ALA reduced the MDA and H2O2 levels in the cotyledons. The antioxidants enzymes (ascorbate peroxidase, peroxidase, catalase, glutathione reductase, and superoxide dismutase) enhanced their activities significantly with the application of 2 mg/l ALA under Cd stress. This study also indicated that higher dosage of ALA (10 mg/l) imposed the negative effect on the growth of oilseed rape. Microscopic study showed that application of ALA alleviated the toxic effects of Cd in the mesophyll cell and improved the cell structure. Use of 2 mg/l ALA under 500 μM Cd was found to be more effective, and under this dosage, cell structure was clear, with obvious cell wall and cell membrane as well as a big nucleus, which was found with well-developed two or more nucleoli. Chloroplast was almost round in shape and contained thylakoids membranes and grana, but starch grains were not found in chloroplast comparatively to other treatments. On the basis of our results, we can conclude that ALA has a promotive effect which could improve plant survival under Cd stress.

Cisplatin augments FAS-mediated apoptosis through lipid rafts

Cisplatin is widely and effectively used for the treatment of various types of cancer. However, its biochemical mechanisms are still unelucidated. Previously, we reported that membrane sphingomyelin (SM) was important for FAS-mediated apoptosis through lipid raft function. In this study, we strikingly show that cisplatin combined with CH11 (anti-FAS antibody, IgM) was able to induce marked apoptosis in SM synthase-restored WR/Fas-SMS1 cells, but not in SM synthase-deficient WR/FAS-SM(-) cells. In addition, we demonstrated that membrane SM played an important role in cisplatin/CH11-induced apoptosis through the classical caspase-dependent pathway, mainly by enhancing the formation of FAS-associated signaling complexes.

Impaired TCR signaling through dysfunction of lipid rafts in sphingomyelin synthase 1 (SMS1)-knockdown T cells

During T cell activation, TCRs cluster at the center of the T cell-antigen-presenting cell interface forming the central supramolecular activation cluster. Although it has been suggested that sphingolipid- and cholesterol-rich microdomains, termed lipid rafts, form platforms for the regulation and transduction of TCR signals, an actual role for membrane sphingomyelin (SM), a key component of lipid rafts, has not been reported. After cloning a gene responsible for SM synthesis, sphingomyelin synthase (SMS) 1, we established a SM-knockdown cell line (Jurkat-SMS1/kd) by transfection of SMS1-short-interfering RNA into Jurkat T cells, which is deficient in membrane expression of SM. Upon CD3 stimulation, expression of CD69 (the earliest leukocyte activation antigen), activation-induced cell adhesion and proliferation as well as TCR clustering was severely impaired in Jurkat-SMS1/kd cells. CD3-induced tyrosine phosphorylation and association of linker for activation of T cell with ZAP-70 and Grb2 and phosphorylation of protein kinase C (PKC) were also severely impaired in Jurkat-SMS1/kd cells. Finally, translocation of TCR, ZAP-70 and PKC into lipid rafts was markedly decreased in Jurkat-SMS1/kd cells. These findings indicate that membrane SM is crucial for TCR signal transduction, leading to full T cell activation through lipid raft function.

Adult Pseudomonas aeruginosa meningitis: high incidence of underlying medical and/or postneurosurgical conditions and high mortality rate

We analyzed the clinical and laboratory characteristics, therapeutic outcome and prognostic factors of 25 cases of cerebrospinal fluid (CSF) culture-proven Pseudomonas aeruginosa adult bacterial meningitis (ABM). Twelve P. aeruginosa strains, isolated from clinical CSF specimens, were tested for antibiotic susceptibility. The 25 cases included 17 men and 8 women, aged 17 to 86 years (median=51). Of the 25 cases of P. aeruginosa ABM, 18 were the result of postneurosurgical infection and the other 7 were spontaneous infections. The latter 7 cases had serious underlying medical conditions. The antibiotic susceptibility rates of the 12 strains were as follows: ceftriaxone 16.7% (2/12), ceftazidime 91.7% (11/12), cefepime 83.3% (10/12), imipenem 83.3% (10/12), meropenem 83.3% (10/12) and ciprofloxacin 66.7% (8/12). The therapeutic results showed an overall mortality rate of 40% (10/25). The emergence of third-generation cephalosporin-resistant P. aeruginosa strains cultured from clinical CSF specimens in recent years has resulted in a therapeutic challenge in the treatment of ABM.

Cloning and expression of two human recombinant monoclonal Fab fragments specific for EBV viral capsid antigen

Serum titers of antibody to Epstein-Barr virus (EBV) viral capsid antigen (VCA) have been positively correlated with malignancies of lymphoid proliferation, such as Burkitt's lymphoma and Hodgkin's lymphoma. We have constructed a phage display combinatorial antibody Fab library from a patient with marginal zone B cell lymphoma associated with Sjögren's syndrome and carrying high serum anti-EBV-VCA IgG titer. Fab fragments were selected by panning against EBV-VCA protein coated onto ELISA plates, and selected Fab clones were characterized by ELISA, western blotting (WB), indirect immunofluorescence assay and immunohistochemistry. We have established two Fab clones, Fab-aVCA1 and Fab-aVCA21, which specifically recognize EBV-VCA by ELISA and WB. Inhibition ELISA competition showed that both clones could significantly reduce the binding of specific anti-EBV-VCA mAb to its relevant proteins. Furthermore, these two Fab clones could localize VCA protein in the EBV-positive P3HR1 and Daudi cell lines, as well as in tissue samples from patients with EBV-infected lymphoid malignancies. These results indicate that our two Fab clones are novel human mAbs specific for EBV-VCA protein and may have potential benefits for development of novel diagnostic and therapeutic approaches in EBV-related lymphoid malignancies.

Fractalkine in rheumatoid arthritis and allied conditions

Leukocyte adhesion and trafficking at the endothelium requires both adhesion molecules and chemotactic factors. Fractalkine (CX3C) is a unique chemokine, and is expressed on tumor necrosis factor-alpha- and interleukin-1-activated endothelial cells (ECs). Fractalkine receptor, CX3CR1, is expressed on NK cells, monocytes, and some portion of CD4- and CD8-positive T cells. Interactions between fractalkine and CX3CR1 can mediate not only chemotaxis, but also cell adhesion in the absence of substrates for other adhesion molecules. Furthermore, fractalkine activates NK cells, leading to increased cytotoxicity and interferon-gamma production. Recently, accumulating evidence has shown that fractalkine is involved in the pathogenesis of rheumatoid arthritis and allied conditions. This review examines new concepts underlying fractalkine-mediated leukocyte migration and tissue damage, focusing primarily on the pathophysiological roles of fractalkine in rheumatic diseases.

Absorption enhancement study of astragaloside IV based on its transport mechanism in caco-2 cells

The purpose of this study was to investigate the transport characteristics and mechanisms for discovering the possible causes of the low bioavailability of astragaloside IV and to develop an absorption enhancement strategy. Caco-2 cells used as the in vitro model. Results showed a low permeability coefficient (3.7 x 10(-8)cm/s for transport from the AP to BL direction), which remained unchanged throughout the concentration range studied, indicating that the transport of astragaloside IV was predominantly via a passive route. The AP to BL transport of astragaloside IV was found to be highly sensitive to the extracellular Ca2+ concentration, which suggested that its transport may be via a paracellular route. Both chitosan and sodium deoxycholate can increase the permeation efficiency of astragaloside IV. This study indicated that astragaloside IV having a low fraction dose absorbed in humans mainly due to its poor intestinal permeability, high molecular weight, low lipophilicity as well as its paracelluar transport may directly result in the low permeability through its passive transport. Meanwhile, chitosan and sodium deoxycholate can be used as absorption enhancers based on its transport mechanism.

Demonstration of different modes of cell death upon herpes simplex virus 1 infection in different types of oral cells

The effects of Herpes simplex virus 1 (HSV-1) infection on five different types of oral cancerous cells (neck metastasis of gingival carcinoma (GNM) cells and tongue squamous cells of carcinoma (TSCCa) and non-cancerous cells (buccal mucosal fibroblasts (BF), gingival fibroblasts (GF), oral submucosal fibrosis cells (OSF)) and one type of non-oral cancerous cells (KB cells) were investigated. In HSV-1-infected cells the cell viability, CPE, viral antigens accumulation, caspase-3 activity, annexin V binding and DNA fragmentation were estimated. Three different forms or pathways of cell death were considered: apoptosis (the presence or rise of caspase-3 activity, DNA fragmentation and annexin V binding), slow cell death (the presence or rise of DNA fragmentation, the absence or decline of caspase-3 activity and annexin V binding), and necrosis (the absence of decline of caspase-3 activity, DNA fragmentation and annexin V binding). The viability of all cell types, except for KB cells, was reduced by the infection. CPE and viral antigens data demonstrated that all six types of cells could be infected with HSV-1. Upon HSV-1 infection there occurred (i) a classical apoptosis in GF cells, (ii) apoptosis in the early phase of infection and necrosis in the late phase of infection in GNM and TSCCa cells, (iii) slow cell death followed by necrosis in BF and OSF cells (however, these cells showed a different type of CPE), (iv) a classical slow cell death in KB cells. It is hypothesized that HSV-1 infection has a potential to induce several distinct pathways leading to cell death or several forms of cell death. Moreover, more than one pathway may be involved in the death of particular cell type. As HSV-1 was demonstrated to infect different oral and non-oral cells and cause different pathways or forms of cell death, the safety of using HSV-1 as a vector for gene therapy should be re-considered.

Community-acquired spontaneous bacterial meningitis in adult diabetic patients: an analysis of clinical characteristics and prognostic factors

BACKGROUND

We analyzed the clinical characteristics and prognostic factors of community-acquired spontaneous bacterial meningitis (CASBM) in adult diabetic patients.

PATIENTS AND METHODS

Over a period of 15 years, 47 adult diabetic patients with CASBM were identified. The clinical characteristics, laboratory data and therapeutic outcome of these 47 patients were statistically analyzed.

RESULTS

The 47 patients were 31 men and 16 women, aged 22 to 79 years, and they accounted for 38.5% (47/122) of our adult patients with culture-proven CASBM. The most common causative pathogen was Klebsiella pneumoniae (n = 32), followed by pathogens of the streptococcal species (n = 6). Besides classic manifestations of bacterial meningitis, bacteremia and focal suppuration, especially liver abscess, were common features in this group of patients. Liver cirrhosis and/or alcoholism were the other frequent underlying conditions. 27 patients survived in the course of therapy. The prognostic factors with statistical significance were glucose ratio and cerebrospinal fluid (CSF) white blood cell (WBC) count.

CONCLUSION

This study showed the high incidence of diabetes mellitus (DM) among the adult patients with CASBM in Taiwan. K. pneumoniae was the most frequent causative pathogen. Bacteremia and focal suppuration, especially liver abscess, were common findings. The values of glucose ratio and CSF WBC count had a statistically significant influence on the prognosis of our patients.

Identification of viridans streptococcal species causing bacterial meningitis in adults in Taiwan

In order to determine the species responsible for viridans-group streptococcal meningitis in adults in Taiwan, seven cases of culture-proven meningitis due to these organisms were studied. The cases were all identified at the Chang Gung Memorial Hospital-Kaohsiung over a period of 3 years, and they accounted for 9% (7/78) of all cases of culture-proven bacterial meningitis occurring in adults during this period. Of the seven viridans streptococci isolates recovered, Streptococcus constellatus accounted for four, Streptococcus anginosus for two, and Streptococcus oralis for one. Thus, it appears that streptococci of the milleri group are the most common species causing bacterial meningitis in adults in Taiwan. The tendency for these organisms to cause invasive central nervous system infections in adults should not be overlooked when these species are recovered from cerebrospinal fluid specimens.

Protean infectious types and frequent association with neurosurgical procedures in adult Serratia marcescens CNS infections: report of two cases and review of the literature

Serratia marcescens is a rare pathogen of adult central nervous system (CNS) infection. We report on the clinical features and therapeutic outcomes of two adult patients with such infections. The clinical characteristics of 13 other reported adult cases are also included for analysis. The 15 cases were nine males and six females, aged 19-83 years, in whom, underlying post-neurosurgical states and ear operation were noted in 93% (14/15). Fever and conscious disturbance were the most common clinical manifestations of these 15 cases, followed by hydrocephalus, seizures, and wound infections. The manifestation types were protean, including meningitis and focal suppurations such as brain abscess, cranial and spinal epidural abscess, cranial subdural abscess, and infected lumbar pseudomeningocele. One case of S. marcescens CNS infection was diagnosed postmortem; the other 14 were diagnosed by the positive culture from CSF or pus. Antibiotic therapy with or without neurosurgical intervention was the management strategy in 14/15 cases. The therapeutic results showed a high mortality rate.

Adult Enterobacter meningitis: a high incidence of coinfection with other pathogens and frequent association with neurosurgical procedures

BACKGROUND

The clinical characteristics of Enterobacter infection in adult bacterial meningitis were defined.

PATIENTS AND METHODS

The clinical manifestations and therapeutic outcomes of ten adult patients with Enterobacter infections in acute bacterial meningitis were analyzed.

RESULTS

Enterobacter infection was found in 4.5% (10/223) of our adult patients with culture-proven bacterial meningitis. The ten patients comprised seven men and three women aged between 16-69 years (mean 47 years). Coinfections with other pathogens were found in 50% of the cases, the most common pathogen being Klebsiella pneumoniae. Nine of the ten patients had a history of neurosurgery, and seven patients contracted the infection nosocomially. Multiple antibiotic-resistant strains, including resistance to third-generation cephalosporins, were found in three patients with polymicrobial infections. These three patients received iv imipenem/cilastin therapy. The therapeutic results showed that two of the ten patients died; five of the eight surviving patients had neurological sequelae.

CONCLUSION

The predominant coinfection with Enterobacteriaceae in adult Enterobacter meningitis may reflect the fact that most of the cases of polymicrobial Enterobacter infections have a potential gastrointestinal source. A postneurosurgical state was the most important predisposing factor for the development of Enterobacter infection in adult bacterial meningitis in our patients. The strains of the Enterobacter species in adult polymicrobial Enterobacter meningitis were commonly resistant to multiple antibiotics, including third-generation cephalosporins. In light of the high incidence of multiple antibiotic-resistant Enterobacter strains in adult polymicrobial Enterobacter meningitis, the choice of initial empiric antibiotics may include carbapenem (imipenem/cilastin or meropenem). Although the mortality rate was not high in this group of patients, most survivors suffered neurological sequelae.

Community-acquired Acinetobacter meningitis in adults

Community-acquired Acinetobacter meningitis in adults is an extremely rare infection of the central nervous system (CNS). Here we report one adult case of this rare CNS infection and review the clinical data of another seven cases reported in the English language literature. In total, eight patients (six men and two women) aged between 19 and 63 years were studied. The causative pathogen in our patient was Acinetobacter baumannii; in the other reported cases they were most likely Acinetobacter Iwoffii, Acinetobacter johnsonii, Acinetobacter junii, a genomic species 3 or 6. No underlying disease was found in seven of the eight cases and six of the eight patients acquired the infections before the age of 30 years. Fever and consciousness disturbance were the most common clinical manifestations. Waterhouse-Friderichsen syndrome (WFS) was found in two cases. Unlike the Acinetobacter strains found in nosocomial infections, the strain of Acinetobacter meningitis in the community-acquired case did not show multiple antibiotic resistance. Most adult patients with community-acquired Acinetobacter meningitis can be saved by timely therapy with appropriate antibiotics before deterioration of the systemic condition and impairment of consciousness.

Effects of surfactants on extraction of phenanthrene in spiked sand

Problems associated with polynuclear aromatic hydrocarbon (PAH) contaminated site in environmental media have received increasing attention. To resolve such problems, innovative in situ methods are urgently required. This work investigated the feasibility of using surfactants to extract phenanthrene on spiked sand in a batch system. Phenanthrene was spiked into Ottawa sand to simulate contaminated soil. Six surfactants, Brij 30 (BR), Triton X-100 (TR), Tergitol NP-10 (TE), Igepal CA-720 (IG), sodium dodecyl sulfate (SDS) and hexadecyl trimethyl ammonium bromide (HTAB) were used. Adjusting the extraction time, mixing speed and surfactant concentration yielded the optimum extracting conditions. The concentration of phenanthrene was identified with HPLC. Under the experimental conditions, results indicated that those surfactants were highly promising on site remediation since the residual phenanthrene concentration was effectively reduced. The optimum operating conditions were obtained at 30 min, 125 rpm and surfactant concentrations in 4%.

Mixed infection in adult bacterial meningitis

12 adult patients suffering from bacterial meningitis caused by mixed infection were identified at Kaohsiung Chang Gung Memorial Hospital over a period of 13 years (1986-1998), and they accounted for 6.5% (12/184) of our culture-proven adult bacterial meningitis. The 12 cases included seven males and five females, aged 17-74 years. Six of the 12 cases had community-acquired infections and the other six had nosocomially-acquired infections. Ten of the 12 cases had associated underlying diseases, with head trauma and/or neurosurgical procedure being the most frequent. Both gram-negative and gram-positive pathogens were identified in these 12 cases with gram-negative pathogens outnumbering the gram-positive ones. The implicated pathogens, starting with the most frequent, included Enterobacter species (Enterobacter cloacae, Enterobacter aerogenes), Klebsiella species (Klebsiella pneumoniae, Klebsiella oxytoca), Escherichia coli, Staphylococcus species (Staphylococcus aureus, Staphylococcus haemolyticus), Pseudomonas aeruginosa, Acinetobacter baumannii, Enterococcus, Serratia marcescens, Citrobacter diversus, Proteus mirabilis, Streptococcus viridans and Neisseria meningitidis. Six of the 12 cases were found to have multi-antibiotic-resistant strains, which included E. cloacae in one, A. baumannii in one, K. pneumoniae in one and S. aureus in three. The management of these 12 cases included appropriate antibiotics and neurosurgical procedures including shunt revision. Despite the complexity of implicated pathogens and the high incidence of emergence of resistant strains, the overall mortality rate (8.3%, 1/12) was not higher than that in adult bacterial meningitis. However, complete recuperation was difficult in adult patients with mixed bacterial meningitis.

Neuroimages of disseminated neurotuberculosis: report of one case

We report a 38-year-old male patient with rare concurrent intracranial and intramedullary tuberculoma demonstrated by serial magnetic resonance image (MRI) and confirmed by a pathological study. The involvement of the middle cerebral artery is also shown by magnetic resonance angiography. These findings have a good correlation with the clinical features including cranial nerve involvement, stroke-like symptoms, and paraplegia.

Screening solution-phase combinatorial libraries using pulsed ultrafiltration/electrospray mass spectrometry

A method is described whereby a family of homologues is synthesized in a one-pot reaction, without isolation or purification, and the reaction mixture is screened using a competitive binding assay based on pulsed ultrafiltration/electrospray mass spectrometry (PUF/ESMS) to tentatively identify those derivatives having the highest affinity for a target receptor. As a model system to test this approach, a synthetic scheme designed to prepare a series of analogues of the adenosine deaminase inhibitor erythro-9-(2-hydroxy-3-nonyl)adenine (EHNA), as diastereomeric mixtures, was carried out. Pulsed ultrafiltration screening of the crude reaction mixture against controls without protein detected protonated molecules corresponding to EHNA-type derivatives and three of its linear, alkyl homologues but did not show protonated molecules for an isobutyl or benzylic EHNA derivative, suggesting the latter was inactive. To verify this conclusion, we prepared E/THNA, the linear homologues, and the benzylic derivative (each as a diastereomeric mixture) and bioassayed them for them adenosine deaminase inhibition index ([I]/[S]0.5). The bioassay results for the individually synthesized analogues were in good agreement with that predicted by the observed relative ion enhancement in the PUF experiments. Thus, the PUF protocol might be used as a general method to quickly provide direction to the chemist in search of drug candidates.

Neuroimages of Japanese encephalitis: report of three patients

The cranial computed tomography (CT) and magnetic resonance image (MRI) studies of three Japanese encephalitis (JE) patients, 24 to 37 years of age, are reported. The initial findings of CT study were limited but initial MRI studies revealed multiple lesions involving the brainstem, basal ganglia and bilateral thalami. Follow-up MRI studies showed small residual lesions only. The result shows that MRI can delineate and detect brain lesions better than CT in patients in the acute stage of JE. The locations of lesions in MRI study are noteworthy and have a good correlation with pathologic anatomic distribution. Therefore, MRI study is helpful in early diagnosis of JE.

Pulsed ultrafiltration mass spectrometry: a new method for screening combinatorial libraries

In response to the need for rapid screening of combinatorial libraries to identify new lead compounds during drug discovery, we have developed an on-line combination of ultrafiltration and electrospray mass spectrometry, called pulsed ultrafiltration mass spectrometry, which facilitates the identification of solution-phase ligands in library mixtures that bind to solution-phase receptors. After ligands contained in a library mixture were bound to a macromolecular receptor, e.g., human serum albumin or calf intestine adenosine deaminase, the ligand-receptor complexes were purified by ultrafiltration and then dissociated using methanol to elute the ligands into the electrospray mass spectrometer for detection. Ligands with dissociation constants in the micromolar to nanomolar range were successfully bound, released, and detected using this method, including warfarin, salicylate, furosemide, and thyroxine binding to human serum albumin, and erythro-9-(2-hydroxy-3-nonyl)adenine binding to calf intestine adenosine deaminase. Repetitive bind- and-release experiments demonstrated that the receptor could be reused. Thus, pulsed ultrafiltration mass spectrometry was shown to provide a simple and powerful new method for the screening of combinatorial libraries in support of new drug discovery.

Influence of Na+ on DNA reactions with aromatic epoxides and diol epoxides: evidence that DNA catalyzes the formation of benzo[a]pyrene and benz[a]anthracene adducts at intercalation sites

Reactions of the benzo[a]pyrene (BP) and benz[a]anthracene (BA) metabolites, (+/-)-trans-7 8-dihydroxy-anti-9, 10-epoxy-7, 8, 9, 10-tetrahydro-BP (BPDE), (+/-)-trans-3, 4-dihydroxy-anti- 1,2-epoxy-1,2,3,4-tetrahydro-BA (BADE), (+/-)-BP-4,5-oxide (BPO), and (+/-)-BA-5, 6-oxide (BAO), were examined under pseudo-first-order conditions at varying Na+ (2.0-100 Mm) and native calf thymus DNA (ctDNA) concentrations. In 0.2 mM ctDNA and 2.0 mM Na+, at a pH of 7.3 most BPDE, BADE, BPO, and BAO (87-95%) undergo DNA catalyzed hydrolysis or rearrangement. For BPDE and BPO, overall, pseudo-first-order rate constants, k, in 2.0 mM Na+ and 0.2 mM ctDNA are 21-72 times larger than values obtained without DNA. For BADE and BAO, the rate constants are less strongly influenced by DNA; k values in 0.2 mM ctDNA are only 9-12 times larger than values obtained without DNA. Kinetic data for BPDE, BPO, BADE, and BAO and DNA intercalation association constants (KA) for BP and BA diols which are model compounds indicate that KA values for BPDE and BPO in 2.0 mM Na+ are 6.6-59 times larger than those of BADE and BAO. The greater DNA enhancement of rate constants for BPDE and BPO, versus BADE and BAO, correlates with the larger KA values of the BP metabolites. DNA adducts, which account for less than 10% of the yields, also form. For BPDE in 0.20 mM ctDNA, k decreases 5.1 times as the Na+ concentration increases from 2.0 to 100 mM. Nevertheless, the DNA adduct level remains constant over the range of Na+ concentrations examined. These results provide evidence that, for BPDE in 0.20 mM DNA and 2.0 mM Na+, ctDNA adduct formation follows a mechanism which is similar to that for DNA catalyzed hydrolysis. The pseudo-first-order rate constant for adduct formation, kAd, given approximately by kAd approximately equal to (kcat,AdKA[DNA])/(1 + KA[DNA]), where kcat,Ad is a catalytic rate constant. for BADE, BPO, and BAO, the influence of varying DNA and Na+ concentrations on k values is similar to that for BPDE, and provides evidence that the formation of adducts follows the same rate law.

Hepatic resection of hepatocellular carcinoma in cirrhotic livers: is it unjustified in impaired liver function?

BACKGROUND

Resection for hepatocellular carcinoma in patients with cirrhosis and impaired liver function is usually unjustified because of higher surgical risks and poorer long-term prognosis.

METHODS

A retrospective comparison of the background and resectional results of patients with cirrhosis and hepatocellular carcinoma was carried out between those with preoperative indocyanine green 15-minute retention rate of 20% or greater (group A, impaired function group, n = 36) and those with indocyanine green 15-minute retention rate of 10% or less (group B, normal function group, n = 34).

RESULTS

The group A patients had significantly lower serum albumin level and higher serum bilirubin level, longer prothrombin time, higher incidence of associated esophageal varices, and poorer Child's classifications for cirrhosis. Although the tumor diameter in both groups was similar (A, 6.9 versus B, 7.1 cm; p = 0.94), the resected liver amount in group B was greater (227.4 versus 473.2 gm; p = 0.038) because of a greater extent of liver resection (p < 0.001) and a wider surgical margin (0.34 versus 1.85 cm; p < 0.0001). The amount of operative blood loss and blood transfusion, operative morbidity, and operative mortality were not different between the two groups. The pathologic characteristics and staging were also comparable. The 5-year disease-free and actuarial survival rates of groups A and B were 30.9% and 29.6% (p = 0.16) and 45.2% and 33.4% (p = 0.11), respectively.

CONCLUSIONS

If the amount of resected nontumorous liver parenchyma could be reduced, resection of hepatocellular carcinoma in selected patients with cirrhosis and impaired liver function is still justified in spite of a narrow surgical margin.

High-performance liquid chromatography-electrospray mass spectrometry of retinoids

High-performance liquid chromatography (HPLC)-electrospray mass spectrometry (LC-MS) was used to analyze vitamin A-active retinoids including retinoic acid, retinol, retinal, and retinyl acetate. Unlike previous LC-MS methods such as negative ion electron capture chemical ionization, no derivatization of retinoic acid was required. HPLC separations were carried out on a C30 reversed phase column with gradient elution using mobile phases containing water, methanol, and methyl-tert-butyl ether. Ammonium acetate (5 mM) was added to the mobile phase to facilitate ion pair formation during reversed phase HPLC of retinoic acid, and acetic acid (0.5% v/v) was added to the mobile phase to enhance protonation during LC-MS analysis of nonacidic retinoids. During negative ion electrospray, retinoic acid formed abundant deprotonated molecules, [M-H]-, of m/z 299 without significant fragmentation. Although retinol, retinal, and retinyl acetate did not ionize during negative ion electrospray, the positive ion electrospray mass spectra of these retinoids showed an abundant protonated molecule of m/z 285 for retinal and base peaks of m/z 269 corresponding to elimination of water or acetic acid from the protonated molecules of retinol or retinyl acetate, respectively. No ions from retinoic acid were detected during positive ion electrospray. Limits of detection for retinoic acid, retinal, retinol, and retinyl acetate were 23 pg, 1.0 ng, 0.5 ng, and 10 ng, respectively.

Multiple fluorescence lifetimes for oligonucleotides containing single, site-specific modifications at guanine and adenine corresponding to trans addition of exocyclic amino groups to (+)-(7R,8S,9S,10R)- and (+)-(7S,8R,9R,10S) -7,8-dihydroxy-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene

Fluorescence decay profiles of four oligonucleotide duplexes, [table: see text] ((+)- and (-)-trans-1) and [table: see text] ((+)- and (-)-trans-2), in which an exocyclic amino group of deoxyadenosine (A*) or deoxyguanosine (G*) has been alkylated by trans opening at C-10 of the epoxide group of either the (+)-(R,S,S,R)- or (-)-(S,R,R,S)-enantiomer of (+/-)-7 beta,8 alpha-dihydroxy-9 alpha,10 alpha-epoxy-7,8,9,10- tetrahydrobenzo[a]pyrene (BPDE in which the benzylic 7-hydroxy group and the epoxide oxygen are trans), exhibit more than one fluorescence lifetime. Decay profiles of the oligomers, measured at 15 degrees C with excitation and emission wavelengths of 335 and 400 nm, respectively, have been analyzed using a triple-exponential decay law. Results for (+)- and (-)-trans-1 and -2 have been compared with results for the modified, single-stranded oligonucleotides ((+)- and (-)-trans-SS-1, and (+)- and (-)-trans-SS-2) and for the cis and trans opened products formed on alkylation at the 6-amino group of 2'-deoxyadenosine 5'-phosphate by (+)-(R,S,S,R)-BPDE ((+)-trans- and (+)-cis-A). The profiles of (+)-trans- and (+)-cis-A are well represented by single-exponential decay laws with lifetimes of 86 and 110 +/- 3 ns, respectively. For the single- and double-stranded oligomer adducts, which exhibit at least three fluorescence lifetimes, two of the lifetimes are short (0.5-14 +/- 1 ns) and one is long (35-59 +/- 3 ns). The fluorescence lifetimes and the amplitudes of the long-lived components in the decay profiles of the double-stranded oligomer adducts are generally smaller than those for the corresponding single-stranded adducts. The data provide evidence that the double-stranded oligomer adducts exist as multiple conformations. Previously reported NMR results suggest that the short lifetime fluorescence components are due to major adduct conformations in which the pyrenyl group is intercalated ((+)- and (-)-trans-1) or lies in the minor groove ((+)- and (-)-trans-2). The observation of long lifetime fluorescence species for the double-stranded oligomers is consistent with the presence of minor conformations (approximately 1-5%) in which the double-stranded oligomer either is locally denatured or is a mixture of locally denatured double-stranded conformations and equilibrium concentrations of single-stranded oligomers.

HPLC preparation of highly purified single-stranded M13 DNA

Closed-circular, single-stranded viral DNAs are widely employed in DNA cloning and sequencing experiments. Because of their well-defined structure and sequence, closed-circular, single-stranded DNAs have also been used for ligand binding experiments and light scattering measurements. However, there is a high molecular weight impurity observed in light scattering experiments, which sometimes contaminates single-stranded DNA purified from phage that has been precipitated in polyethylene glycol, average molecular weight 8000, and purified by standard phenol-chloroform extraction. Three methods have been examined that remove this impurity from closed-circular, single-stranded M13mp19 DNA (SS M13 DNA). One employs a commercial peparation. This procedure yields pure but degraded SS M13 DNA, as shown by light scattering measurements and HPLC. Another employs a Whatman DE52 (diethylamino cellulose) column. This procedure yields intact DNA, but in poor yield (less than 20% of that obtained by phenol-chloroform extraction). The last was the most successful. This employs HPLC with a Waters AP-1 column with DEAE 8HR bedding. This procedure, which provides DNA in high yield (80%-90% column recovery) with an intact structure, is an efficient method for the isolation of high-purity, closed-circular, single-stranded viral DNA suitable for physical investigations and ligand binding measurements.

[Urogenital rhabdomyosarcoma in children: analysis of 39 cases]

From 1967 to 1992, 39 patients with urogenital rhabdomyosarcoma were admitted to our hospital. Of them 30 were male and 8 female and their age ranged from 4 months to 14 years (32 were less than 5 years). Primary tumor was located in bladder or/and prostate in 26, paratesticule 9, vagina 3, and penis 1. Among the 31 patients receiving treatment, 23 were followed up. There were 15 (65%) survivors, including 13 who were free from tumor for over 4 years. The eldest two patients were 20 and 21 years of age. Two patients with vaginal tumor and 4 with bladder tumor preserved their organs with normal function. Biopsy were done only in 8 patients. In recent years, conservative surgery combined with chemotherapy for urogenital rhabdomyosarcoma has been justified.

Nucleotide sequence of the coat protein coding region of the potyvirus tobacco vein-banding mosaic virus

The sequence of the 3' 1184 nucleotides of tobacco vein-banding mosaic virus (TVBMV) genome has been determined. It contains a single open reading frame which encompasses the whole of the coat protein of TVBMV. The sequence of the first 20 amino acids at the N-terminal region of the coat protein has also been determined chemically to be GDDQTVDAGKNVQSNQKQRN. The sequence matches the translation product of the open reading frame starting with amino acid-271; a glycine residue. Thus the coat protein of TVBMV has a calculated M(r) of 30,210. The 3' non-coding region of TVBMV is 185 nucleotides in length. Sequence alignment of the coat proteins or the 3' non-coding regions from TVBMV and other reported potyviruses indicated that TVBMV is a separate species of the potyvirus genus.

Cloning and characterization of the latent membrane protein (LMP) of a specific Epstein-Barr virus variant derived from the nasopharyngeal carcinoma in the Taiwanese population

A DNA fragment containing Epstein-Barr virus (EBV) terminal fragment sequence was obtained from a genomic library of nasopharyngeal carcinoma (NPC). One of the clones (clone 1510) contained the gene encoding latent membrane protein (LMP). Sequence analysis revealed that this gene had 95% homology with the LMP sequence of the B95-8 strain. Among the sequence variations, there was a change from G to T at nucleotide position 169,426, resulting in the loss of an XhoI site in exon 1 of the LMP gene. A pair of primers bracketing the XhoI site were designed to synthesize the EBV DNA fragment from nucleotides 169,081-169,577 by using the polymerase chain reaction (PCR) method. The PCR products were then subject to XhoI digestion and to DNA sequencing analysis. This restriction enzyme site polymorphism along with the sequence variations were also observed in 50 biopsy tissues as well as in the throat washings of 6 out of 20 healthy individuals that we examined, indicating that the EBV strain predominantly existing in these biopsy tissues was different from strains of B95-8, Jijoye or nude mouse passaged cells (C15) with an African origin, but closely resembled other nude mouse passaged CAO cells which were originally derived from China. Balb/c 3T3 cells carrying this NPC-LMP gene showed a transformed cell morphology and were tumorigenic in nude mice. The relationship between this unique type of EBV and NPC has yet to be established.

Room-temperature steady-state fluorescence properties of poly(dG-dC).poly(dG-dC)

We report the steady-state fluorescence properties of the alternating polynucleotide poly(dG-dC).poly(dG-dC) in low-salt solution at room temperature for excitation at the Hg lines 265, 280 and 297 nm. Its fluorescence spectrum peaks at about 325 nm and, within the experimental error, its shape does not change significantly with the excitation wavelength. The fluorescence anisotropy is found to decrease strongly for short-wavelength excitation, a behavior which is very similar to that exhibited by free guanine. In view of the fact that the anisotropy for free cytosine is virtually constant at the aforementioned three excitation wavelengths, the results suggest that in this polynucleotide the emission stems from guanine. The values of the fluorescence quantum yield for the three excitation wavelengths are found to be very low, 0.8 x 10(-5), 0.8 x 10(-5), and 2.8 x 10(-5), respectively; these are compatible with transfer of energy from the lower-energy electronic state of guanine, before vibronic relaxation is established, to cytosine. Upon denaturation, the fluorescence spectrum becomes very broad and the fluorescence quantum yield increases; these observations support the authenticity of the emission from the nondenatured polynucleotide.

Singlet-singlet energy transfer along the helix of a double-stranded nucleic acid at room temperature

An irreversible electronic energy trap has been formed in calf thymus DNA by methylating about 75% of its G bases at position N-7. This has allowed us to measure for the first time the efficiency of transfer of energy along the helix of a double-stranded nucleic acid at room temperature. It is found that about one out of every three photons absorbed by the other bases is trapped. We have also simulated the data with a stochastic model that uses the dipole-dipole interaction to calculate the efficiency of transfer. In order to approximate the experimental results, the model requires that: (i) the fluorescence quantum yield of T, C, and G in DNA be about 2 x 10(-3), which is about two orders of magnitude larger than the value of the fluorescence quantum yield reported for DNA; and (ii) the fluorescence quantum yield of A in DNA be negligibly small. Requirement (i) is consistent with energy transfer taking place before a very efficient fluorescence quenching process sets in, which could be formation of excited-state complexes (excimers) that do not fluoresce appreciably. Requirement (ii) implies a very short fluorescence lifetime for A, which is consistent with the reported absence of a significant number of photoproducts formed by A in DNA. The simulations find that, on the average, the excitation energy takes about 1.2 steps to reach the trap; that is to say, bases that are nearest and next nearest neighbors of the trap are, in effect, the only energy donors. Both intra- as well as interstrand energy transfer (the latter only for the C-trap base pair) make significant contributions. The value of the efficiency for pairwise base-base intrastrand transfer is about 60%, whereas those for base-trap intra- and interstand transfer are 90% and 80%, respectively. The corresponding values for the rate constant of transfer are 2 x 10(11), 1 x 10(12), and 4 x 10(11) s-1. Transfer is inefficient when A is the donor or the acceptor. In addition to the dipole-dipole term, the only other significant term in the expansion of the interaction potential is the dipole-quadrupole term which, however, makes only a small contribution to the overall transfer efficiency. The electron exchange interaction appears to be much less efficient than the coulombic interaction.

Periodontal conditions in elderly people of Shanghai, People's Republic of China, in 1986

In a stratified multi-stage random sample, 1600 persons of 60 years and older in Shanghai, People's Republic of China, were investigated for periodontal conditions using the CPITN method. Periodontal conditions seemed to deteriorate steadily but rather slowly with increasing age. In the older age groups, there was a trend for an increased proportion of both subjects and sextants scoring CPITN code 4 (deep pockets). The increase in tooth loss with increasing age was more clearly visible: increasing percentages of edentulousness and decreasing mean numbers of teeth remaining in dentate subjects.

Acute transformation of chronic large granular lymphocyte leukemia associated with additional chromosome abnormality

A patient with large granular lymphocyte (LGL) leukemia that transformed into an acute or aggressive form after 20 months of the chronic phase is reported. The patient's leukemic cells were mature, medium-sized lymphocytes with sparse azurophil granules and the surface phenotypes of the cells were CD2+, CD3-, CD11+, and CD16+. Molecular analysis showed a germ line configuration in both T-cell receptor beta-chain genes and T-cell receptor tau-chain genes. A clonal anomaly of chromosome (trisomy 8) was demonstrated in peripheral blood cells. LGL after acute transformation of the disease displayed large blastic morphology with prominent nucleoli, intense basophilic cytoplasm, and numerous granules. Karyotypic analysis demonstrated a mosaic of trisomy 8 and trisomy 8 with an additional marker chromosome. Thus, transformation of chronic LGL leukemia into an acute or aggressive form in this patient was associated with morphologic and karyotypic changes of the leukemic cells. Patients with a stable form of chronic LGL leukemia should be examined carefully for the possible acute crisis associated with a clonal evolution.

Effects of hematocrit on thixotropic properties of human blood

The rheological properties of whole human blood exhibit thixotropic behavior at low shear rates up to about ten reciprocal seconds (1). The accepted cause of this shear rate-dependent and time-dependent behavior is the progressive breakdown of rouleaux into individual red cells. Huang developed a rheological equation which incorporates the kinetics of rouleau breakdown in his models (2). This five-parameter equation was used successfully to represent the hysteresis loop and the torque-decay curve of whole human blood. Numerical values of these five thixotropic parameters, which characterize the rheological behavior of the blood from apparently healthy human subjects, were established (3). In this communication, we examined the effect of hematocrit on each of the above mentioned parameters. The results show that the following parameters will increase their values with an increase in hematocrit: the yield stress, Newtonian contribution of viscosity, non-Newtonian contribution of viscosity, apparent viscosity and the equilibrium value of the structural parameter which indicates the relative amount of rouleaux in blood. Mathematical equations were developed to give the relationship between parameters and hematocrit. Two other thixotropic parameters, viz. the kinetic rate constant of rouleaux breakdown into individual red cells and the order of the breakdown reaction, were found to be independent of the hematocrit. It is consistent with reaction kinetic theory that the rate constant and the order of reaction are independent of the concentration of reactants.

Thixotropic properties of whole blood from healthy human subjects

The steady state non-Newtonian viscosity of whole human blood has been widely studied as a function of the shear rate; and used to characterize the blood in various pathological disorders. In our previous studies, we demonstrated that blood is a thixotropic fluid. Its time-dependency and shear rate dependency of rheological behavior can be represented by an equation developed by Huang. Parameters of the equation can be used for the characterization of an individual's blood. They provide information, such as the kinetic rate constant of breakdown of RBC rouleaux to individual erythrocytes and the relative amount of rouleau formation in the dynamic equilibrium between rouleaux and individual erythrocytes. In this communication, the thixotropic parameters from blood samples of fifteen apparently healthy human subjects were investigated. When compared to the use of apparent viscosity values for the correlation with a pathological disorder, thixotropic parameters are preferable. The mean values of thixotropic parameters obtained from apparently healthy human subjects provide a base for comparison with the same parameters as obtained from blood samples of patients with certain pathological disorders involving the circulation.