Value of a single preoperative PFA-100 measurement in assessing the risk of bleeding in patients taking cyclooxygenase inhibitors and undergoing total knee replacement.

BACKGROUND: The usefulness of the PFA-100 in assessing the risk of bleeding in non-cardiac surgery is not clear. This study aims to examine this by correlating preoperative PFA-100 measurement with perioperative bleeding in patients receiving cyclooxygenase (COX) inhibitors. METHODS: PFA-100 with adenosine-5'-diphosphate (ADPCT) and epinephrine (EPICT) cartridges were measured before operation in consecutive patients undergoing elective total knee replacement and taking different COX inhibitors. Surgery and anaesthesia were performed by the same team using standardized techniques. Intraoperative blood loss and postoperative drain output were recorded by anaesthetists and nurses blinded to the PFA-100 measurements. Surgeons, similarly blinded, were asked to rate the quality of haemostasis. Correlation was sought between these data and PFA-100 measurements. RESULTS: Thirty patients were studied, involving 51 knees. Preoperative PFA-100 EPICT was correlated with drain output (r=0.30, P=0.03). The correlation becomes stronger when a 20% in vitro haemodiluted sample was used for measurement (r=0.42, P=0.01). Receiver-operating characteristic curve analysis using the diluted measurements [area under curve (AUC) 0.74 (95% CI 0.54-0.94)] suggested using a cut-off value of 188 s for EPICT, which will predict excessive drain output with 89% sensitivity, 54% specificity, and a likelihood ratio of 1.93. Diluted EPICT was also correlated with surgeon rating of haemostasis (r=0.36, P=0.04) although none of the measurements correlated with intraoperative blood loss. CONCLUSIONS: Preoperative PFA-100 prolongation is correlated with increased postoperative drain output. It can be a potentially useful preoperative measurement in patients taking COX inhibitors.

Coactivations of elbow and shoulder muscles in hemiplegic persons with chronic stroke during robot-assisted training.

The motor recovery procedure of chronic stroke during robot-assisted training has not been well studied previously. In this work, we analyzed the variations in the coactivating patterns of elbow and shoulder muscles (biceps, triceps lateral, anterior deltoid, and posterior deltoid) in hemiplegic persons with chronic stroke (n=4) during a 20-session's interactive robot-assisted treatment. Significant decreases in muscle cocontractions (P<0.05) for all muscle pairs started from the 8th session of the training. Improvements were also observed in motor scores of Fugl-Meyer and modified Ashworth scale after the treatment. The results suggested an increased dexterity and selective control on individual muscles for both elbow and shoulder joints in a designed task after the robot-assisted training.

The therapeutic effects of myoelectrically controlled robotic system for persons after stroke--a pilot study.

In this study, a myoelectrically controlled robotic system with one degree of freedom was developed to assist elbow training in the horizontal plane for patients after stroke. The system could provide assistive extension torque which was proportional to the amplitude of the subject's processed and normalized electromyograhpic (EMG) signal from triceps. The system also provided different resistive torques during movement, which were based on the maximum isometric voluntary extension (MIVE) and flexion (MIVF) torques. A study investigated its effect after 20-session of training for four weeks on the functional improvement of the affected arm in 3 subjects after stroke. Outcome measurements on the muscle strength at the elbow joint showed that there were increases in the MIVE and MIVF torques of the affected arms of all the subjects after the four-week rehabilitation training. The subjects could also reach a more extended position without the assistance of the robotic system than that before the four-week training.

Effect of American ginseng extract (Panax quinquefolius) on formalin-induced nociception in mice.

Twenty-three ICR mice were force fed orally with American ginseng extract, Panax quinquefolius, (Cold FX) for 4 days. Another 20 mice were fed with water as placebo in a similar fashion. Formalin tests which yield typically two phases of pain behavior were done in both groups. Although there was no difference in the first phase between groups, mice treated with Cold FX spent significantly less time in licking and biting of the injured paws in the second phase. The data indicate that American ginseng may have analgesic effect in this chronic pain model.

Effects of melatonin, morphine and diazepam on formalin-induced nociception in mice.

The possible analgesic effect of melatonin was investigated in young male ICR mice. The formalin test which elicits typically 2 phases of pain response, the acute (first) phase and tonic (second) phase, was used. The test was performed in the late light period when the mice have been reported to be more sensitive to pain. Compared to control mice, no significant difference in nociceptive response was observed when melatonin was injected intraperitoneally at doses of 0.1, 5, and 20, mg/kg body weight. The combined effects of melatonin with diazepam and/or morphine, were also investigated. Melatonin, injected at 20 mg/kg 15 min before formalin test, significantly increased the antinociceptive response of diazepam (1 mg/kg) or morphine (5 mg/kg) in the second phase. In addition, when melatonin was given at 20 mg/kg together with diazepam and morphine, antinociceptive responses in both the first and second phase were increased. These data indicate the synergistic analgesia effect of melatonin with morphine and diazepam and suggest the possible involvement of melatonin as an adjunct medicine for pain patients.

K1 and K3 capsular antigens of Klebsiella induce tumor necrosis factor activities.

Capsular polysaccharide antigens isolated from Klebsiella pneumoniae sero-type 1 (K1) and sero-type 3 (K3) could induce tumor necrosis factor-alpha in ICR mice. K1 and K3 capsular antigens were found to be non-toxic by brine shrimp bioassay. When injected into Ehrlich ascites tumor-bearing mice, both K1 and K3 capsular antigens exhibited significant suppression in the growth of tumor cells. The significance of these observations is discussed.

Activation of the anti-tumor effector cells by Radix bupleuri.

Radix bupleuri, the root of Bupleuri spp., Chinese medicinal herbs used for the treatment of influenza, malaria and menstrual disorders, were extracted with hot water and separated into five different fractions (RB, RBI, RBII, RBIII and RBIV) by stepwise alcohol precipitation. One of these fractions, RBI, was then fractionated into RBIa and RBIb by gel filtration using G-100 Sephadex. These two fractions were further purified into RBIai, RBIaii and RBIbi, RBIbii fractions respectively by ion-exchange chromatography using DEAE-Sephadex. Each of these fractions is a heteropolymer consisting mainly of carbohydrate and varying proportions of protein and uronic acid. RBIaii was found to show strong anti-tumor activities in sarcoma-bearing mice. Mechanistic studies showed that RBIaii exhibited a potent activating effect on the cytotoxic activity of macrophages, NK and LAK cells against tumor cells. In addition, RBIaii could increase the number of tumor infiltrating lymphocytes (TILs) in the tumor site of WEHI-164-bearing mice. Furthermore, RBIaii could induce the release of interferon-gamma by lymphocytes in vitro.

Delineation of the cis-acting element mediating EBNA-2 transactivation of latent infection membrane protein expression.

To delineate the cis-acting element through which EBNA-2 transactivates latent membrane protein 1 (LMP1), we assayed the effect of EBNA-2 on the activity of LMP1 promoter upstream deletion mutants in the context of the LMP1 or heterologous promoters controlling chloramphenicol acetyltransferase (CAT) reporter gene expression in Epstein-Barr virus-negative Burkitt lymphoma cells. Assays of progressive 5' deletions of the LMP1 promoter revealed low constitutive and at least eightfold EBNA-2-stimulated activity from -512 to +40 (-512/+40), -334/+40, and -234/+40 LMP1CAT plasmids. More extensive 5'-deleted -205/+40, -155/+40, and -147/+40 LMP1CAT plasmids also had low constitutive activity but were not EBNA-2 responsive. The most 5'-deleted -55/+40 LMP1CAT plasmid had moderate constitutive activity and was not EBNA-2 inducible. Either orientation of the -334/+40 LMP1 sequence conferred EBNA-2 responsiveness when positioned upstream of an enhancerless simian virus 40 or herpes simplex virus thymidine kinase (TK) promoter. EBNA-2 and the cis-acting LMP1 DNA were both required to increase TK promoter-initiated mRNA, indicating that the EBNA-2 effect is at the transcriptional level. Further deletion analysis of the EBNA-2-responsive cis-acting element defined a -234/-92 LMP1 DNA fragment which conveyed EBNA-2 responsiveness to the herpes simplex virus TK promoter. The 5' 30 bp between -234 and -205 were essential for EBNA-2 responsiveness. Thus, these experiments define a 142-bp cis-acting element which is sufficient for conveying EBNA-2 responsiveness and an essential 30-bp component of that element. The role of this element in LMP1 and LMP2B expression and its possible role in LMP2A expression are discussed.

Epstein-Barr virus nuclear protein 2 transactivates a cis-acting CD23 DNA element.

Epstein-Barr virus (EBV) nuclear protein 2 (EBNA-2) is essential for B-lymphocyte growth transformation. EBNA-2 upregulates mRNAs encoding CD23, a B-lymphocyte surface protein closely associated with EBV-induced growth transformation. To further investigate this EBNA-2 effect, we searched in the genomic DNA spanning the type a and type b CD23 mRNA start sites for a cis-acting fragment that would render a promoter transactivatable by EBNA-2. An 800-bp CD23 DNA fragment (-335 to +465 relative to the type a CD23 mRNA start site) conferred EBNA-2 responsiveness to the herpes simplex virus thymidine kinase (TK) promoter when transfected into EBV-negative B-lymphoma cells. Deletional analysis identified a -275/-89 subfragment that was EBNA-2 responsive when cloned in either orientation and at variable distances upstream of the heterologous promoter. EBNA-2 and the cis-acting CD23 element increased TK-promoted mRNA and did not alter the herpes simplex virus TK promoter transcription start site. As expected, a type a CD23 promoter (-335/+80) which contained the EBNA-2-responsive element was transactivated by EBNA-2. As in EBV infection and stable EBNA-2 transfection, the CD23 DNA element in cis with heterologous or homologous promoters was less responsive to type 2 than to type 1 EBNA-2, whereas the EBNA-2-responsive DNA fragment from the EBV latent membrane protein 1 promoter was more responsive to the type 2 EBNA-2. These experiments delineate a 186-bp, EBNA-2-responsive cell DNA fragment and provide firm evidence that EBNA-2 transactivates transcription of cell genes. The greater type 1 versus type 2 EBNA-2 responsiveness of the CD23 promoter and the lack of a similar effect on the latent membrane protein 1 promoter is consistent with the hypothesis that greater cell gene transactivation by type 1 EBNA-2 is the basis for the more efficient growth-transforming properties of type 1 EBV.

Epstein-Barr virus nuclear antigen 2 transactivates latent membrane protein LMP1.

Several lines of evidence are compatible with the hypothesis that Epstein-Barr virus (EBV) nuclear antigen 2 (EBNA-2) or leader protein (EBNA-LP) affects expression of the EBV latent infection membrane protein LMP1. We now demonstrate the following. (i) Acute transfection and expression of EBNA-2 under control of simian virus 40 or Moloney murine leukemia virus promoters resulted in increased LMP1 expression in P3HR-1-infected Burkitt's lymphoma cells and the P3HR-1 or Daudi cell line. (ii) Transfection and expression of EBNA-LP alone had no effect on LMP1 expression and did not act synergistically with EBNA-2 to affect LMP1 expression. (iii) LMP1 expression in Daudi and P3HR-1-infected cells was controlled at the mRNA level, and EBNA-2 expression in Daudi cells increased LMP1 mRNA. (iv) No other EBV genes were required for EBNA-2 transactivation of LMP1 since cotransfection of recombinant EBNA-2 expression vectors and genomic LMP1 DNA fragments enhanced LMP1 expression in the EBV-negative B-lymphoma cell lines BJAB, Louckes, and BL30. (v) An EBNA-2-responsive element was found within the -512 to +40 LMP1 DNA since this DNA linked to a chloramphenicol acetyltransferase reporter gene was transactivated by cotransfection with an EBNA-2 expression vector. (vi) The EBV type 2 EBNA-2 transactivated LMP1 as well as the EBV type 1 EBNA-2. (vii) Two deletions within the EBNA-2 gene which rendered EBV transformation incompetent did not transactivate LMP1, whereas a transformation-competent EBNA-2 deletion mutant did transactivate LMP1. LMP1 is a potent effector of B-lymphocyte activation and can act synergistically with EBNA-2 to induce cellular CD23 gene expression. Thus, EBNA-2 transactivation of LMP1 amplifies the biological impact of EBNA-2 and underscores its central role in EBV-induced growth transformation.

Rate of arabinitol production by pathogenic yeast species.

D-Arabinitol is a five-carbon polyol that is produced by many fungi. Detection of the metabolite has been reported in serum from patients with invasive candidiasis. We studied the production and assimilation of arabinitol by 46 clinical isolates of yeast species. Cultures of isolates of Candida albicans (9 strains), Candida tropicalis (12 strains), Candida parapsilosis (13 strains), Candida krusei (4 strains), Candida pseudotropicalis (3 strains), Torulopsis glabrata (3 strains), and Cryptococcus neoformans (2 strains) were assayed by gas-liquid chromatography. Yeast cells were cultured at 34 degrees C in yeast nitrogen base with 3.0 g of glucose per liter. At 1.5- to 3-h intervals, cells were counted and glucose and arabinitol were measured in media filtrates. The levels of arabinitol in cultures with 7.5 X 10(6) yeast cells per ml were compared. The mean concentrations of the metabolite in C. albicans, C. tropicalis, C. parapsilosis, and C. pseudotropicalis cultures wee 14.1, 1.6, 8.4, and 5.5 micrograms/ml, respectively. No arabinitol was detected in cultures of C. krusei, T. glabrata, or C. neoformans.