Examination of factors affecting the intraoral perception of object size: a preliminary study.

Oral sensory function is essential for the successful performance of a range of ingestion. Although the perception of object size is important in determining the degree of manipulation, evidence suggests that people does not always perceive the size of the object in oral cavity accurately. The purpose of this study was to investigate the factors affecting the intraoral perception of object size. Twenty-three healthy young volunteers detected the size of cylinders inserted into oral cavity blindly and identified it from the reference set. The diameter of cross section varied from 10 to 14 mm in a gap of 1 mm and had three different temperatures (5, 36, 50 °C) in each. The perceived size was recorded, and the difference with the actual size was assessed. The required time for identification was also measured and compared between gender and between temperatures. The results demonstrated that the direction of size illusion was significantly affected by the required time for identification. Long manipulation led to overestimation, and short manipulation led to underestimation of object size irrespective of temperature and size. Gender was the other factor affecting intraoral size perception. The rate of overestimation was low in female participants comparing with male participants in this experiment, although the number of participants was limited. We therefore concluded that in order to detect the other factors affecting intraoral size perception, regulating oral manipulation time is indispensable.

Impact of control measures including decolonization and hand hygiene for orthopaedic surgical site infection caused by MRSA at a Japanese tertiary-care hospital.

BACKGROUND: Meticillin-resistant Staphylococcus aureus (MRSA) is the most common pathogen in orthopaedic surgical site infections (SSIs). However, few studies have investigated the transmission process of orthopaedic MRSA SSI. AIM: To investigate the transmission process of orthopaedic MRSA SSI using epidemiological and molecular analyses and to determine a method to prevent MRSA SSI in nosocomial orthopaedic surgery. METHODS: Active MRSA surveillance, preoperative decolonization and contact precautions for MRSA-positive cases was performed at our institution. Changes in epidemic strains were evaluated and the possibility of transmission from patients in an orthopaedic ward of a Japanese tertiary-care hospital was assessed by genotyping stored MRSA strains. In addition, data on the prevalence of MRSA SSI, MRSA colonization, and use of an alcohol antiseptic agent (mL/patient-days) during 2005-2022 were retrospectively assessed. FINDINGS: SCCmec type II strain in the SSI group decreased over time, associated with fewer outbreaks. Even during a period of high infection rates, no cases of transmission-induced SSI from nasal MRSA carriers were identified. The infection rate correlated negatively with the use of an alcohol antiseptic agent (r = -0.82; P < 0.0001). Two cases among five nasal carriers developed MRSA SSI caused by strains different from those related to nasal colonization. CONCLUSION: The infection control measures for transmission from the hospital reservoirs including strict adherence to hand hygiene and decolonization of carriers is likely to be important for the prevention of orthopaedic MRSA SSI. However, the need for contact precautions for decolonized nasal carriers might be low.

Typing of O26 enterohaemorrhagic and enteropathogenic Escherichia coli isolated from humans and cattle with IS621 multiplex PCR-based fingerprinting.

AIMS: This study evaluated a typing method of O26:H11 enterohaemorrhagic and enteropathogenic Escherichia coli (EHEC and EPEC) based on the variation in genomic location and copy numbers of IS621. METHODS AND RESULTS: Two multiplex PCRs, targeting either the left (5') or right (3') IS/chromosome junction of 12 IS621 insertion sites and one PCR specific of another truncated copy, were developed. Thirty-eight amplification profiles were observed amongst a collection of 69 human and bovine O26:H11 EHEC and EPEC. Seventy-one per cent of the 45 EHEC and EPEC with identical IS621 fingerprints within groups of two, three or four isolates had >85% pulsed field gel electrophoresis (PFGE) profile similarity, including four groups of epidemiologically related EHEC or EPEC, while most of the groups had <85% similarity between each others. Epidemiologically related EHEC from each of three independent outbreaks in Japan and Belgium also exhibited identical IS621 fingerprints and PFGE profiles. CONCLUSIONS: The IS621 fingerprinting and the PFGE are complementary typing assays of EHEC and EPEC; though, the former is less discriminatory. SIGNIFICANCE AND IMPACT OF THE STUDY: The IS621 printing method represents a rapid (24 h) first-line surveillance and typing assay, to compare and trace back O26:H11 EHEC and EPEC during surveys in farms, multiple human cases and outbreaks.

Expression and tumorigenicity of the Epstein-Barr virus BARF1 gene in human Louckes B-lymphocyte cell line.

We previously showed that the Epstein-Barr virus, which encodes the BARF1 gene, could transform rodent fibroblasts. In this work, the expression of the BARF1 gene was studied in the human Louckes B-lymphocyte cell line. Introduction of the BARF1 open reading frame under the control of the Mo-MuLV LTR promotor into nontumorigenic Louckes lymphoid cells led to the activation of the c-myc protooncogene and increased expression of the B-cell surface proteins, the transferrin receptor, CD21, and CD23. BARF1-expressing cells induced a diffuse lymphoma-like tumor in newborn rats treated with anti-thymocyte serum that was, however, transient and regressed after 3-4 weeks as the immune system recovered. The tumor induction was similar to that observed with lymphoid cell lines in vitro generated by infection with the B95-8 virus strain, in which lytic antigens are expressed at low levels. After long-term culture, Louckes cell clones lost expression of the BARF1 gene and were unable to induce tumors.

Expression of BARF1 gene encoded by Epstein-Barr virus in nasopharyngeal carcinoma biopsies.

We reported previously that the EBV BARF1 open reading frame encodes a Mr 31,000-33,000 protein (p31) with potential transforming and oncogenic properties. This gene was found capable of transforming both: (a) the rodent fibroblast lines Balbc/3T3 and NIH3T3 into cells producing aggressive tumors in newborn rats; and (b) the human EBV-negative B-cell line Louckes into cells leading to small tumors, which disappeared 3 weeks after injection. Our recent study showed that BARF1 ORF expression may confer the property of immortalization to primary kidney epithelial cells (M. X. Wei et al., Oncogene, 14: 3073-3081, 1997). Because this suggested that BARF1 could be involved in epithelial malignancy, we investigated its transcriptional and translational expressions in Algerian nasopharyngeal carcinoma (NPC) biopsies by reverse transcription-PCR and immunoblotting using rabbit polyclonal antisera prepared against two synthetic peptides corresponding to distinct, predicted epitopes of the BARF1 protein (NGGVMKEKD, amino acids 172-180, and GKNDKEE, amino acids 203-209). The BARF1 ORF was found to be transcribed and translated in >85% of our NPC biopsies, with high p31 protein level detected in several NPC patient biopsies as well as in NPC-derived xenografts. Our observation of BARF1 expression in a large proportion of NPC epithelial cells suggests that this EBV gene might play an important role in the malignant transformation of human epithelial cells in vivo.

N-terminal domain of BARF1 gene encoded by Epstein-Barr virus is essential for malignant transformation of rodent fibroblasts and activation of BCL-2.

The BARF1 gene encoded by the Epstein-Barr virus induces morphological changes, loss of contact inhibition and anchorage independence in established rodent Balb/c3T3 fibroblast. BARF1 gene was also capable of inducing malignant transformation in a human Louckes B cell line. Our recent study showed that BARF1 gene had an ability to immortalize primary epithelial cells. However we do not know which region(s) of BARF1 protein is(are) responsible for inducing malignant transformation in established rodent cells. Using the deletion mutants, we now localized a malignant transforming region in N-terminal of BARF1 protein. The mutants lacking this region were unable to transform the cells in malignant state. Furthermore, we demonstrated that only the mutants containing this region rendered the cells resistant to apoptosis induced by serum deprivation. Surprisingly, the BARF1 gene was capable of activating anti-apoptotic Bcl-2 expression and this activation was due to the N-terminal transforming region. These data suggest that the cooperation of BARF1 with Bcl-2 is essential for the induction of malignant transformation.

Establishment of a monkey kidney epithelial cell line with the BARF1 open reading frame from Epstein-Barr virus.

We previously reported that the BARF1 (BamH1-A right frame 1) gene product from Epstein-Barr Virus (EBV) may have oncogenic properties since injection into new-born rats of transfected cell lines resulted in the development of BARF1 expressing tumors, which were aggressive in the case of murine fibroblasts and transient in that of human B lymphocytes. As EBV has been associated with nasopharyngeal carcinoma (NPC) and evidence of BARF1 transcription in this cancer was emerging from our biopsy analyses, we examined the effects of BARF1 transfection into primate primary epithelial cells. The expression of the BARF1 open reading frame in primary monkey kidney epithelial cells led us to the establishment of continuously dividing lines. The BARF1 transfectants showed the major characteristics of immortalized cells: morphological change, short cell doubling time, ability to divide at low cell density and continuous growth over 50 passages. Injection of BARF1 transfectants into nude mice did not induce any tumor. Established subclones were shown to be epithelial cells expressing known keratins as well as the BARF1 coded mRNA and protein. This is the first report indicating that expression of the BARF1 gene product in primary epithelial cells may contribute to the establishment of cell lines.

Structural and membrane modifying properties of suzukacillin, a peptide antibiotic related to alamethicin. Part A. Sequence and conformation.

The primary structure and conformation of the polypeptide antibiotic suzukacillin A are investigated. Suzukacillin A is isolated from the Trichoderma viride strain 1037 and exhibits membrane modifying and lysing properties similar to those of alamethicin. A combined gas chromatographic mass spectrometric analysis of the trifluoroacetylated peptide methyl esters of partial hydrolysates revealed a tentative sequence of 23 residues including 10 2-methylalanines and one phenylalaninol, which shows many fragments known from alamethicin: Ac-Aib-Pro-Val-Aib-Val-Ala-Aib-Ala-Aib-Aib-Gln-Aib-Leu-Aib-Gly-Leu-Aib-Pro-Val-Aib-Aib-Glu(Pheol)-Gln-OH. All chiral amino acids and phenylalainol have L-configuration. Ultraviolet and infrared spectroscopy, circular dichroism in various solvents and in particular 13C nuclear magnetic resonance have been used for a comparative study of suzukacillin with alamethicin. Suzukacillin has a partially alpha-helical structure and the helix content increases largely from polar to lipophilic solvents. Suzukacillin aggregates more strongly than alamethicin in aqueous medis due to a longer alpha-helical part and higher number of aliphatic residues. A part of the alpha-helix is exceptionally stabilized due to 2-methylalanine residues shielding the peptide bonds from interactions with polar solvents. In lipophilic solvents and lecithin vesicles particularly large temperature induced reductions of the high alpha-helix content are found for alamethicin. Suzukacillin shows similar temperature coefficients in lipophilic media, however, in contrast to alamethicin a more linear change in intensity of the Cotton effects is observed.

Structural and membrane modifying porperties of suzukacillin, a peptide antibiotic related to alamethicin. Part B. Pore formation in black lipid films.

Suzukacillin, a polypeptide consisting of presumably 23 amino acids and 1 phenylalaninol, is produced by a Trichoderma viride strain No. 1037 and it can be isolated from the culture medium. It shows membrane-modifying properties similar to those of alamethicin. Discrete condustance fluctuations indicate the formation of oligomer pores of varying diameter. On the basis of voltage jump relaxation experiments evidence is given that the dimer is the nucleation state from which pore formation starts and the oligomer disappears. According to the voltage-current characteristics, voltage-dependent and voltage-independent conductances are observed. A slow process is involved, which can be interpreted as a change in the equilibrium distribution between different conformations of the suzukacillin monomer at the membrane interphase. This change results from its interaction with the lipid matrix. Differences in experimental observations between suzukacillin and alamethicin are attributed to the relatively larger alpha-helix and higher number of aliphatic side chains of the suzukacillin monomer and to a more intense interaction with the lipid membrane. This leads to a higher probability of forming dimers from monomers and to the occurrence of "inactivation".

Expression and analysis of the Epstein-Barr virus BARF1-encoded protein from a tetracycline-regulatable adenovirus system.

Epstein-Barr virus (EBV) has been associated with human cancers of lymphocytic or epithelial origin. Potential functions of the BARF1 early gene in EBV oncogenesis emerged from our observations showing expression of BARF1-encoded protein in nasopharyngeal carcinoma biopsies, and induction of either malignant transformation (in rodent fibroblast and human B cell lines) or immortalization (in monkey primary epithelial cells) following BARF1 transfection. We previously reported expression of the BARF1 product as a cytoplasm/membrane-associated protein from 293-tTA cells infected with a BARF1-recombinant adenovirus. Since constitutive expression of BARF1 from this heterologous system became inefficient, we developed a tetracycline-regulatable recombinant vector expressing BARF1 and green fluorescent protein from a dicistronic message. As here reported, stable and efficient expression of BARF1 from this vector in either permissive or non-permissive cell lines, allowed the first sequencing identification and further molecular characterization of BARF1-encoded protein.

Epstein-Barr virus encoded BALF1 gene is transcribed in Burkitt's lymphoma cell lines and in nasopharyngeal carcinoma's biopsies.

BACKGROUND: The Epstein-Barr virus (EBV) encodes two anti-apoptotic cellular Bcl2 homologs, BALF1 and BHRF1. BHRF1 has an anti-apoptotic activity but is rarely expressed in nasopharyngeal carcinoma (NPC). However, BALF1 is not yet well characterized. OBJECTIVES: The objective of the study was to characterize BALF1 gene. First, the search of its transcriptional expression in EBV-positive B cell lines, EBV-positive Burkitt's lymphoma's cell lines and nasopharyngeal carcinoma's biopsies. Second, the examination of its anti-apoptotic activity in serum dependent assays. STUDY DESIGN: We first analysed the transcriptional expression of BALF1 by reverse transcriptase DNA polymerase chain reaction (RT-PCR) method. For the analysis of its anti-apoptotic activity, we transfected NIH3T3 cells with pBABE-BALF1 expression plasmid and studied serum dependence of these transfectants. RESULTS: BALF1 expression was detected in the latent stage and increased more significantly during the lytic phase in IgG-treated AKATA and TPA-SB-treated P3HR1-TK negative cell lines. As its expression was not affected by the inhibitor of viral DNA synthesis, this gene does not belong to late gene family. When analysed its transcription in Burkitt's lymphoma (BL)-derived cell lines and NPC biopsies, all BL-derived cell lines and more than 80% of NPC biopsies transcribed this gene. The study of serum dependence of BALF1-transfected NIH3T3 cells showed: with 10% of serum, BALF1 transfectants grew significantly more higher cell density than vector alone transfected NIH3T3 cell lines and with 1% of serum, BALF1 transfectants were capable of growing, but with about 40% reduced rate in comparison with those with 10% serum, while vector alone transfected NIH3T3 cells could not almost grow. CONCLUSION: BALF1 gene was transcribed in EBV-associated tumor cells. BALF1 could render cells to serum independent. These results suggest that BALF1 gene could play its role in EBV oncogenesis.

Co-existence of the A and B types of Epstein-Barr virus DNA in lymph node biopsies from Algerian patients with Hodgkin's disease and non-Hodgkin's lymphoma.

The association of Epstein-Barr virus (EBV) with Hodgkin's disease (HD) and non-Hodgkin's lymphoma (NHL) was examined in Algerian patients. The DNA extracted from fresh lymph node biopsies of 17 HD and five NHL was analysed by polymerase chain reaction (PCR). Fifteen out of 17 biopsies (88%) from HD contained EBV genome. Viral type analysis showed the coexistence of A and B types of EBV in 14 biopsies (93%), and the sole presence of A type virus in one biopsy. Among five NHL biopsies examined, four biopsies contained both A and B types of EBV, while one revealed A type-virus only. This co-infection of Algerian HD and NHL patients does not seem to be related with any histologic form of these diseases. The analysis of viral types in the saliva from 12 Algerian healthy individuals revealed six EBV positives with only one A type. Two types of lymphoma in Algeria therefore are closely associated with EBV, and are characterized by coinfection with A and B types of EBV.

Studies on changes in DNA polymerase activity during the cell cycle in synchronized KB cells.

We have demonstrated the presence of two DNA polymerases in KB cells and studied the variation of their activities in a synchronous cell population. During the cell cycle we observed in nuclei, only one DNA dependent DNA polymerase, the 3.4 S or minipolymerase, and similarly in the cytoplasm only one enzyme, the 8.3 S or maxipolymerase. The former shows preference for native DNA and the latter for denatured DNA. Their Mg++ and K+ requirements are different and their pH optima are 8.5 and 7 for nuclear polymerase and cytoplasmic polymerase respectively. The cytoplasmic polymerase activity remains stable from one cell cycle to the other with each cell reconstituting its stock at the start of the following cycle (G1 and early S phases). On the contrary nuclear activity decreases in G2, M and early G1, then increases to a maximum in the middle of the S phase. This fluctuation in enzyme activity could be due to degradation, transfer to the cytoplasm or the association of the enzyme with the chromatin and/or the nuclear membrane after completion of DNA synthesis. Our results do not permit us to choose between these three hypotheses. However their significance is discussed in the light of the results obtained by some authors who, on the contrary, have tended to minimise the role of the minipolymerase in DNA duplication, whereas we, from our findings, ascribe a preponderant role to this enzyme. The cytoplasmic maxipolymerase (8.3 S) may simply be a storage form of the enzyme from which minipolymerase can be formed as needed.

Expression of the protein encoded by Epstein-Barr virus (EBV) BARF1 open reading frame from a recombinant adenovirus system.

Epstein-Barr virus (EBV) has been associated with human cancers of lymphocytic or epithelial origin, but viral functions implied in oncogenesis are not yet clear. We previously reported the oncogenic transformation of rodent fibroblast and human B lymphocyte cell lines by the BARF1 coding sequence from EBV. We more recently observed immortalizing effects of this gene on monkey kidney primary epithelial cells. Here we describe an efficient recombinant adenovirus expression system which allowed us to characterize BARF1 translation products, with the help of rabbit polyclonal antibodies raised to the entire protein. The present data demonstrate that BARF1 encodes a 31-33 kDa hydrophobic protein, linked to cell membranes though also recovered in the cytosol, and recognized by human sera from patients with various EBV-related pathologies.

Transcriptional expression of the viral genome in the Epstein-Barr virus-induced tamarin lymphoma and the corresponding lymphoblastoid tumour lines.

Inoculation of the cottontop tamarin with Epstein-Barr virus (EBV) invariably gives rise to mono- or oligoclonal large cell lymphoma occurring at multiple sites, and which resembles to a certain extent B cell lymphoma that occurs in the immunodeficient patient. The viral transcriptional pattern in tamarin tumour biopsies and in the corresponding tumour cell lines was investigated by means of the synthesis of radioactive single-stranded cDNA. It was found that the EBV transcripts came mainly from the fragments BamH1-H, BamH1-S, BamH1-A and EcoR1-Dhet. Transcripts from a few other early or late genes, namely BARF1, BSLF1/BMLF1, BBLF-4, BLLF1 and BXLF2, were also detected in one of the three biopsies tested. It would be important to characterize the transcripts that originate from the region where viral latent expression has not previously been observed. Our results also revealed that there is a sharp increase in EBV transcription in the tumour cell lines derived from the tamarin lymphomas. Simultaneously, the copy number of the viral genome was found to be amplified. Such a significant change in viral activity might be indicative of a close virus-host cell interaction in vivo.

Inhibition of human and woodchuck hepatitis virus DNA polymerase by the triphosphates of acyclovir, 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-iodocytosine and E-5-(2-bromovinyl)-2'-deoxyuridine.

The triphosphates of acyclovir (ACV), 1-(2'-deoxy-2'-fluoro-beta-D-arabinofuranosyl)-5-iodocytosine (FIAC) and E-5-(2-bromovinyl)-2'-deoxyuridine (BVdU) have been examined for their inhibitory effects on the endogenous DNA polymerase reactions of human hepatitis B virus (HBV) and woodchuck hepatitis virus (WHV). All three triphosphates (ACVTP, FIACTP and BVdUTP) inhibited the HBV and WHV DNA polymerases by competing with the corresponding natural substrates. FIACTP was the most potent inhibitor of HBV and WHV DNA polymerase while ACVTP was the least effective inhibitor. The inhibitory properties of these compounds were compared with those of the 5'-triphosphates of 1-beta-arabinofuranosyl-cytosine (ara-CTP) and 1-beta-arabinofuranosylthymine (ara-TTP). The 50% inhibitory doses for HBV and WHV DNA polymerases were in the following order: FIACTP less than BVdUTP less than ara-TTP less than ACVTP less than ara-CTP. BVdUTP appeared to be an efficient alternate substrate to dTTP for HBV DNA polymerase while FIACTP was much less efficient when substituted for dCTP. ACVTP did not act as an alternate substrate to dGTP and appeared to prevent DNA chain elongation.

Frequency characteristics of airway and tissue impedances in respiratory diseases.

We measured the frequency characteristics (at 10-40 Hz) of airway (Za) and tissue (Zt) impedances in cases of chronic obstructive pulmonary disease [asthmatic bronchitis (AB), chronic pulmonary emphysema (CPE)] and interstitial pneumonitis (IP) by use of an improved random noise oscillation and body box method. The results were then compared with those obtained for normal subjects. The real part of Za was markedly elevated in patients with AB but only slightly elevated in those with CPE. To interpret these data we used an electromechanical analogue including serial inhomogeneity with shunt impedance. From this model we concluded that AB causes both the central and peripheral airway resistances to increase, while CPE brings about a rise mainly in peripheral resistance. In IP patients, only the imaginary part of Zt decreased, which might reflect the decrease in both lung and chest wall compliance. In CPE patients, but not in AB patients, the real part of Zt fell. These data were consistent with the assumption that the decrease in mass per unit volume of lung tissue and hyperinflation of the chest wall in CPE patients might lower the tissue resistances.

The molecular biology of Epstein-Barr virus.

Epstein-Barr virus (EBV) was discovered in continuously growing tumor cells derived from African patients with Burkitt's lymphoma. In the intervening twenty years, much biological and biochemical information has been accumulated. The virus infects B lymphocytes and occupies a unique position among human herpesviruses in that it is the only one which is capable of forming a latent infection whereby complete copies of the virus genome persist in growth transformed cells. Since there are no fully permissive cell systems of virus replications, only the established B cell lines are available for study of the molecular events of EB virus in infected cells. A viral cycle consists of four stages, latent, early replicative, middle replicative and late replicative stages. In the latent state, only small parts of the viral genome are transcribed and express transformation proteins: nuclear antigens (EBNAs) and lymphocyte determined membrane antigen (LYDMA). After reactivation of viral genome and during a productive cycle, more than 50 RNAs are expressed and over 30 viral-specified polypeptides are detectable by immunoprecipitation with a high titer human anti-EBV serum. During the early replicative stage, early antigens (EA) and DNA enzymes, both necessary for DNA synthesis, are synthesized. In the late replicative stage, about 30-40 mRNA are transcribed and two major late antigen complexes, viral capsid antigens (VCA) and membrane antigens (MA), are identified. These antigens are indispensable for the formation of virions.

Locally invasive pulmonary aspergillosis in a healthy man successfully treated with oral fluconazole.

A 74-year-old healthy man with locally invasive form of pulmonary aspergillosis (PA) is reported. Chest X-ray film showed a segmental infiltration of right upper lobe (RUL) without cavitation, and the transbronchial lung biopsy specimen contained numerous hyphae of aspergillus species. Complication of bronchial asthma, or bronchiectasis were absent, and hyphae of aspergillus were present at only one segment of RUL. After 5 months of therapy with oral fluconazole, the PA had dramatically improved. Fluconazole was found to be effective for the locally invasive form of PA in a healthy man.

[Epidural anesthesia with high dose fentanyl for a patient with dilated cardiomyopathy].

Dilated cardiomyopathy is defined as a syndrome of dilated ventricles with gross impairment of ventricular systolic function. Recently, there are several anesthetic reports regarding this syndrome. But any appropriate anesthetic method has not been established. A 59-year-old man with dilated cardiomyopathy underwent low anterior resection of rectum. We employed the technique of high dose epidural fentanyl anesthesia as the anesthetic method. During surgery, mild hypotension developed, but other cardiovascular abnormalities were not observed during and after the operation. Based on this result, the authors recommend that high dose epidural fentanyl anesthesia is an anesthetic method of choice for patients with dilated cardiomyopathy.