Endogenous analgesic effect of pregabalin: A double-blind and randomized controlled trial

BACKGROUND

Conditioned pain modulation (CPM) is widely used to measure endogenous analgesia, and a recent study indicated that drugs that act on endogenous analgesia are more effective in individuals with lower CPM. Recent animal studies have indicated that pregabalin activates endogenous analgesia by stimulating the descending pain inhibitory system. The present study examined whether the analgesic effect of pregabalin is greater in individuals with lower original endogenous analgesia using CPM.

METHODS

Fifty-nine healthy subjects were randomly assigned to either a pregabalin group or a placebo group, and 50 of them completed the study. CPM was measured before and after pregabalin or placebo administration. The correlation of initial CPM to change in CPM was compared between the pregabalin and placebo groups.

RESULTS

Initial CPM was significantly correlated with the change in CPM in the pregabalin group (r = -0.73, p < 0.0001) but not in the placebo group (p = 0.56) (difference in correlation coefficients between groups; p = 0.004). Furthermore, the initial CPM significantly affected the change in CPM in the pregabalin group but not in the placebo group (pregabalin group: adj R²  = 0.51, p < 0.001, y = -0.54x + 2.98; placebo group: p = 0.56, significant difference in regression slopes; p = 0.015). These results indicate that pregabalin has a higher endogenous analgesic effect in individuals with lower original endogenous analgesia.

SIGNIFICANCE

The analgesic effect of pregabalin depends on the original endogenous analgesia status. Its effect on conditioned pain modulation (CPM) was stronger for subjects with lower original endogenous analgesia, suggesting that the mechanism of pregabalin involves the improvement of endogenous analgesia.

Hydrothermal impacts on trace element and isotope ocean biogeochemistry

Hydrothermal activity occurs in all ocean basins, releasing high concentrations of key trace elements and isotopes (TEIs) into the oceans. Importantly, the calculated rate of entrainment of the entire ocean volume through turbulently mixing buoyant hydrothermal plumes is so vigorous as to be comparable to that of deep-ocean thermohaline circulation. Consequently, biogeochemical processes active within deep-ocean hydrothermal plumes have long been known to have the potential to impact global-scale biogeochemical cycles. More recently, new results from GEOTRACES have revealed that plumes rich in dissolved Fe, an important micronutrient that is limiting to productivity in some areas, are widespread above mid-ocean ridges and extend out into the deep-ocean interior. While Fe is only one element among the full suite of TEIs of interest to GEOTRACES, these preliminary results are important because they illustrate how inputs from seafloor venting might impact the global biogeochemical budgets of many other TEIs. To determine the global impact of seafloor venting, however, requires two key questions to be addressed: (i) What processes are active close to vent sites that regulate the initial high-temperature hydrothermal fluxes for the full suite of TEIs that are dispersed through non-buoyant hydrothermal plumes? (ii) How do those processes vary, globally, in response to changing geologic settings at the seafloor and/or the geochemistry of the overlying ocean water? In this paper, we review key findings from recent work in this realm, highlight a series of key hypotheses arising from that research and propose a series of new GEOTRACES modelling, section and process studies that could be implemented, nationally and internationally, to address these issues.This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

Involvement of tazarotene-induced gene 1 in proliferation and differentiation of human adipose tissue-derived mesenchymal stem cells

OBJECTIVE

Mesenchymal stem cells (MSC) have both self-renewal and multilineage differentiation potential, and bone marrow-derived MSC have been applied for tissue regeneration and repair. Although adipose tissue-derived MSC (ASC) have emerged as an alternative cell source, little information is available regarding the biologic difference between ASC derived from visceral and subcutaneous fat. Therefore, we aimed to compare the proliferation and gene expression profile of cultured human visceral ASC (VASC) and subcutaneous ASC (SASC), and to identify a novel gene involved in proliferation and differentiation of ASC.

MATERIALS AND METHODS

We performed microarray analysis of cultured VASC and SASC, and investigated the role of tazarotene-induced gene 1 (TIG1), a most differentially expressed gene, in the proliferation and differentiation of ASC.

RESULTS

SASC proliferated faster than VASC for over 10 passages, and TIG1 expression was consistently up-regulated in VASC of humans, rats and mice. Overexpression of the TIG1 gene in human SASC inhibited cell proliferation, whereas knockdown of TIG1 expression by siRNA promoted cell proliferation. In addition, overexpression of the TIG1 gene in SASC enhanced their differentiation into adipocytes, and promoted up-regulation of peroxisome proliferators-activated receptor gamma and CCAAT/enhancer binding protein alpha. On the other hand, TIG1 overexpression in SASC inhibited their differentiation into osteocytes and the expression of osteocalcin.

CONCLUSION

TIG1 plays an important role in regulating proliferation and differentiation of ASC.

Lysine decarboxylase of Vibrio parahaemolyticus: kinetics of transcription and role in acid resistance

AIM

The aim of this study was to investigate the detailed mechanisms of acid resistance in Vibrio parahaemolyticus.

METHODS AND RESULTS

All 11 strains of V. parahaemolyticus survived lethal acidic conditions following acid adaptation, and accumulation of cadaverine was detected. The addition of lysine improved survival, suggesting that lysine decarboxylase plays a role in the adaptive acid tolerance response. Two open reading frames (ORF) in V. parahaemolyticus, which are separated by a noncoding region, were found to be highly homologous to bacterial lysine decarboxylase (cadA) and lysine/cadaverine antiporter (cadB) genes. Transcriptional analyses of this operon revealed acid induction and enhanced induction by external lysine. The relative expression ratio of each transcript was found to follow the trend of cadA mRNA > cadB mRNA > cadBA bi-cistronic mRNA. A mutated strain, with a disrupted cadA gene, showed attenuated acid survival.

CONCLUSIONS

We identified the lysine decarboxylase gene operon of V. parahaemolyticus. Expression of this operon was induced under acidic conditions. The cadA-mutated strain constructed in this study showed weaker tolerance to acidic conditions than the wild-type strain.

SIGNIFICANCE AND IMPACT OF THE STUDY

Vibrio parahaemolyticus utilizes the lysine decarboxylation pathway for survival in acidic conditions.

Basic subsite theory assumptions may not be applicable to hydrolysis of cellooligosaccharides by almond beta-glucosidase

Steady-state kinetic parameters for the hydrolysis of cellooligosaccharides by almond beta-glucosidase were evaluated at pH 5.0 and 25 degrees C in relation to the subsite theory (K. Hiromi, Biochem. Biophys. Res. Commun., 40, 1-6, 1970). The value of k0/Km decreased monotonously with increasing degree of polymerization (DP) of the substrates (DP = 2-6). Also, the Km and k0 values for cellotriose were smaller than those for cellobiose. These DP dependencies differ from those of most amylases and glucosidases studied so far, to which the subsite theory has been successfully applied. The subsite parameters could not be consistently obtained, which suggests that one or both of the two basic assumptions of the subsite theory might not be applicable to the hydrolysis of cellooligosaccharides by the enzyme. That is, the intrinsic rate of the hydrolysis may depend on the DP and/or there may be interaction between subsites for binding the glucose residues of a substrate.

Bone defects in latent TGF-beta binding protein (Ltbp)-3 null mice; a role for Ltbp in TGF-beta presentation

The latent transforming growth factor (TGF)-beta binding proteins (LTBP)-1, -3 and -4 bind the latent form of the multipotent cytokine TGF-beta. To examine the function of the LTBPs, we made a null mutation of Ltbp-3 by gene targeting. The homozygous mutant animals developed cranio-facial malformations by 12 days. By three months, there was a pronounced rounding of the cranial vault, extension of the mandible beyond the maxilla, and kyphosis. The mutant animals developed osteosclerosis of the long bones and vertebrae as well as osteoarthritis between 6 and 9 months of age. These latter phenotypic changes were similar to those described for mice that have impaired TGF-beta signaling. Thus, we suggest that Ltbp-3 plays an important role in regulating TGF-beta bioavailability as the phenotype of the Ltbp-3 null mouse appears to result from decreased TGF-beta signaling. Histological examination of the skulls from null animals revealed no effects on calvarial suture closure. However, the synchondroses in the skull base were obliterated within 2 weeks of birth. This is in contrast to the wild-type synchondroses, which remain unossified throughout the life of the animal and enable growth of the skull base through endochondral ossification. Histological changes in mutant basooccipital-basosphenoid synchondrosis were observed 1.5 days after birth. Compared with wild-type or heterozygous littermates, the basooccipital-basosphenoid synchondrosis of Ltbp-3 null mice contained increased numbers of hypertrophic chondrocytes. The expression of bone sialoprotein-1 (a marker for osteoblasts) was observed in cells surrounding the synchondrosis at postnatal day 1.5 indicating ectopic ossification. The expression of Indian hedgehog (Ihh) (a marker for chondrocytes committed to hypertrophic differentiation) was found through the basooccipital-basosphenoid synchondrosis, whereas the expression of parathyroid hormone related protein (PTHrP), which inhibits chondrocyte differentiation, appeared to be diminished in Ltbp-3 null mice. This suggests that Ltbp-3 may control chondrocyte differentiation by regulating TGF-beta availability. TGF-beta may regulate PTHrP expression either downstream of Ihh or independently of Ihh signaling.

Apolipoprotein J/clusterin is induced in vascular smooth muscle cells after vascular injury

BACKGROUND

Understanding the precise molecular mechanisms underlying the phenomenon of restenosis after PTCA may help us to develop a new strategy for the treatment of restenosis after PTCA. The purpose of this study was to identify the genes involved in vascular restenosis.

METHODS AND RESULTS

Applying a differential hybridization method to a model of the balloon-injured rabbit aorta, we identified 6 cDNA clones that were upregulated after injury. Northern blot showed that 5 genes, but not apolipoprotein J (apoJ)/clusterin, were constitutively expressed in noninjured aorta and upregulated after balloon injury. ApoJ mRNA was not detectable in noninjured aorta (control), began to be expressed at 6 hours after injury, showed a peak level at 24 hours (a 48-fold increase), gradually declined, and returned to the control level at 24 weeks. Western blot and immunohistochemistry demonstrated no expression of apoJ protein in noninjured aorta, an expression of apoJ at 2 days after balloon injury, and a peak level (a 55-fold increase) at 2 to 8 weeks. The expression of apoJ protein continued until 24 weeks after injury. In situ hybridization revealed that apoJ mRNA was expressed in smooth muscle cells (SMCs) of media at 2 days after injury and in SMCs of media and neointima at 2 weeks. To analyze the function of apoJ, stably transfected rabbit SMCs were created. The expression of apoJ stimulated proliferation and migration of SMCs.

CONCLUSIONS

ApoJ is dramatically induced in media and neointima after vascular injury, suggesting that apoJ contributes to restenosis after angioplasty.

Direct neurotoxicity of tetracaine on growth cones and neurites of growing neurons in vitro

BACKGROUND

Local anesthetics have direct neurotoxicity on neurons. However, precise morphologic changes induced by the direct application of local anesthetics to neurons have not yet been fully understood. Also, despite the fact that local anesthetics are sometimes applied to the sites where peripheral nerves may be regenerating after injury, the effects of local anesthetics on growing or regenerating neurons have never been studied.

METHODS

Three different neuronal tissues (dorsal root ganglion, retinal ganglion cell layer, and sympathetic ganglion chain) were isolated from an age-matched chick embryo and cultured for 20 h. Effects of tetracaine were examined microscopically and by a quantitative morphologic assay, growth cone collapse assay.

RESULTS

Tetracaine induced growth cone collapse and neurite destruction. Three neuronal tissues showed significantly different dose-response, both at 60 min and at 24 h after the application of tetracaine (P < 0.01). The ED50 values (mean +/- SD) at 60 min were 1.53+/-1.05 mM in dorsal root ganglion, 0.15+/-0.05 mM in retinal, and 0.06+/-0.02 mM in sympathetic ganglion chain cultures. The ED50 values at 24 h were 0.43+/-0.15 mM in dorsal root ganglion, 0.07+/-0.03 mM in retinal, and 0.02+/-0.01 mM in sympathetic ganglion chain cultures. Concentration of nerve growth factor in the culture media did not influence the ED50 values. The growth cone collapsing effect was partially reversible in dorsal root ganglion and retinal neurons. However, in the sympathetic ganglion culture, no reversibility was observed after exposure to 1 mM tetracaine for 10 or for 60 min. Bupivacaine had similar neurotoxicity to the three types of growing neurons. (The ED50 values at 60 min were 2.32+/-0.50 mM in dorsal root ganglion, 0.96+/-0.16 mM in retinal, and 0.18+/-0.05 mM in sympathetic ganglion chain cultures. The ED50 values at 24 h were 0.34+/-0.09 mM in dorsal root ganglion, 0.21+/-0.06 mM in retinal, and 0.45+/-0.10 mM in sympathetic ganglion chain cultures.)

CONCLUSIONS

Short-term exposure to tetracaine produced irreversible changes in growing neurons. Growth cones were quickly affected, and neurites degenerated subsequently. Sensitivity varied with neuronal type and was not influenced by the concentration of nerve growth factor. Because a similar phenomenon was observed after exposure to bupivacaine, the toxicity to growing neurons may not be unique to tetracaine.

[Colony and phage-plaque direct sequencings by dye-terminator methods]

Direct sequencing using lambda phage DNA and E. coli colonies with plasmid DNA is a very powerful technique. Almost all of the reported direct sequencing methods involve either radioactive sequencing or fluorescent dye-primer sequencing. We present a direct colony sequencing strategy that uses a dye terminator (BigDye terminator kit) together with dye primer sequencing. We found that single-colony sequencing with the terminator yielded about 500 base pairs of sequence information. Signal strength was not improved when the number of cycles increased to 40. The colony used for the sequencing was estimated to contain about 5.6 x 10(7) cells. In addition, although a single plaque consisted of 2 x 10(6) cells, the pfu was not high enough to read with single-cycle sequencing, and only about 300 base pairs of sequence information were obtained from a single plaque using two cycle-sequencing reactions (re-cycle sequencing). The optimal amounts of the template were 500 ng of purified lambda DNA and 1 x 10(7) pfu of the lambda phage suspension, but with BigDye terminator it was possible to detect as little as 50 ng of purified lambda DNA and 2 x 10(6) pfu for lambda phage suspensions. Thus, colony direct sequencing and plaque direct sequencing are estimated to be very useful for rapid and high-throughout screening of genomic and cDNA libraries.

[Detection of visceral ischemia with doplex scanning method of mesenteric arteries: in patients with acute type B aortic dissection]

Between March, 1997 and January, 1999, 11 patients with acute type B aortic dissection underwent doplex scanning evaluation of mesenteric arteries for the early detection of visceral ischemia. Peak systolic velocity (PSV) of the celiac artery (CeA) and superior mesenteric artery (SMA) was measured on their admission. Mean PSV of CeA in the non-ischemic group (8 patients) and in the ischemic group (3 patients) was 1.66 +/- 0.34 m/sec and 3.60 +/- 0.49 m/sec (p = 0.0481), respectively. Mean PSV of the SMA in the non-ischemic group and in the ischemic group was 1.93 +/- 0.52 m/sec and 3.33 +/- 0.37 m/sec (p = 0.00768), respectively. All patients with PSV of the mesenteric arteries above 3.00 m/sec presented visceral ischemia that required emergency operation. If PSV of the mesenteric arteries exceeds 3.00 m/sec, urgent surgical repair should be considered.

Effects of 5-HT2 and 5-HT3 receptors on the modulation of nociceptive transmission in rat spinal cord according to the formalin test

We used the formalin test to clarify the 5-hydroxytryptamine (5-HT) receptor subtypes involved in the modulation of spinal nociceptive transmission in rats. Intrathecal administration of a 5-HT1A receptor agonist, 8-hydroxy-2-(di-n-propylamino)-tetraline (8-OH-DPAT; 1, 10, and 30 microg), or a 5-HT1B receptor agonist, 1, 4-dihydro-3-(1, 2, 3, 6-tetrahydro-4-pyridinyl)-5H-pyrrol (3, 2-b) pyridin-5-one (CP 93129; 1 and 10 microg), produced no significant change in the number of flinches. A 5-HT(2) receptor agonist, (+/-)-2, 5-dimethoxy-4-iodoamphetamine (DOI; 10, 30, and 100 microg), and a 5-HT3 receptor agonist, 2-methyl-5-HT (100 and 300 microg), produced dose-dependent decreases in the number of flinches in phases 1 (1 to 6 min) and 2 (10 to 61 min) of the test. The antinociceptive effects of DOI and 2-methyl-5-HT were antagonized by intrathecal pretreatment with a 5-HT2 receptor antagonist, ketanserin, and a 5-HT3 receptor antagonist, 3-tropanyl-3, 5-dichlorobenzoate (MDL-72222), respectively. These results suggest that 5-HT2 and 5-HT3 receptors in the spinal cord mediate antinociception to chemical stimuli.

[Endoventricular circular patch plasty (dor operation) for postinfarction left ventricular aneurysm and ischemic cardiomyopathy]

The determination of purse-string suture line is one of the most important point in endoventricular circular patch plasty (Dor operation) for postinfarction left ventricular aneurysm (LVAN), especially for ischemic cardiomyopathy (ICM). We suggest following three points to decide appropriate suture line. First, the purse-string suture on the basal side should be placed on the 1-2 cm level under diagonal branch. Secondly, lateral wall should not be over excluded to maintain left ventricular function. And the third, akinetic or dyskinetic lesion of apex and septal wall should be excluded as much as possible. Nine cases of five LVAN and four ICM were underwent Dor operation in our institute from Dec. 1999 to Jan. 2000. All patients were weaned from cardiopulmonary bypass easily except one patient, who was operated under IABP support, because of his preoperative severe heart failure. All patients recovered well without any serious complications and postoperative left ventricular graphies were satisfactory. Left ventricular ejection fraction and stroke volume index were increased from 34 +/- 17 to 55 +/- 16% and from 38 +/- 7 to 47 +/- 6 ml/m2, end-diastric and systric volume index decreased from 141 +/- 37 to 88 +/- 19 ml/m2 and from 96 +/- 41 to 41 +/- 23 ml/m2 respectively. The Dor procedure adopted our idea led to satisfactory result in hemodynamic and also in morphologic study.

A rat model of postthoracotomy pain: behavioural and spinal cord NK-1 receptor assessment

PURPOSE

To develop a new rat model of postthoracotomy pain for investigating its mechanisms and clarifying neurochemical changes.

METHODS

Male Wistar rats were randomly assigned to three groups that underwent either fourth and fifth intercostal nerve ligation, cutting of the fourth and fifth ribs, or a sham operation in which only pleura was cut. For behavioural response assessment during the following month, pinch and touch were used as mechanical stimuli, and acetone was used as a cold thermal stimulus. In addition, (125)I-substance P autoradiography was used to determine neurokinin (NK) receptor density in spinal cord laminae I and II at one to six weeks after surgery.

RESULTS

In rats with nerve ligation, hypersensitivity to noxious and non-noxious stimuli continued throughout the month. The "mirror phenomenon" was observed. The lowest threshold was obtained in the dorsomedial portion of the T4 dermatome on the side of surgery. In rats with rib cutting, a lowered threshold to noxious and non-noxious stimuli was observed for two weeks. In rats with sham operations, hypersensitivity was seen only at postoperative day one. NK-1 receptor density on the side of operation increased significantly in rats with nerve ligation from day seven to 28. Receptor density was highest on day 14 (22.97 +/- 1.04 fmol x mg(-1) tissue vs. control, 16.22 +/- 0.43), representing a 50% receptor excess on the side of ligation compared to the contralateral side.

CONCLUSION

Intercostal nerve damage induces long-term postthoracotomy pain and an increase of spinal NK-1 receptors in rats. This model may be useful for investigation of postthoracotomy pain.

Determination of picomolar levels of iron in seawater using catalytic cathodic stripping voltammetry

A new procedure for the direct determination of picomolar levels of iron in seawater is presented. Cathodic stripping voltammetry (CSV) is preceded by adsorptive accumulation of the iron(III)-2,3-dihydroxynaphthalene (DHN) complex from seawater, containing 20 microM DHN at pH 8.0, onto a static mercury drop electrode, followed by reduction of the adsorbed species. The reduction current is catalytically enhanced by the presence of 20 mM bromate. Optimized conditions include a 60-s adsorption period at -0.1 V and a voltammetric scan using sampled dc modulation at 10 Hz. In these conditions, a detection limit of 13 pM iron in seawater was achieved which can be lowered further by extending the adsorption time to 300 s. The new catalytic CSV method is approximately 5 times more sensitive than existing CSV methods and was tested on samples from the Atlantic Ocean.

[The trends of Vibrio parahaemolyticus foodborne outbreaks in Tokyo: 1989-2000]

The total number of foodborne outbreaks due to Vibrio parahaemolyticus in Tokyo during the last 12 years between 1989 and 2000 were 710. The number of outbreaks in a year was 55 in 1989, 75 in 1990, and there was a gradual decrease to 24 outbreaks in 1993 which was the smallest number during those 12 years. After 1994, the number of outbreaks increased dramatically year by year until 1998 (107 outbreaks). Then they had decreased slightly to 74 in 1999, 65 in 2000. The monthly incidence of V. parahaemolyticus foodborne outbreaks showed a peak in August (44.2%) each year. In the last 12 years, 88.7% of V. parahaemolyticus foodborne outbreaks occurred during the 3 months between July and September, while 99.9% occurred between June and October. The most prevalent serotype of V. parahaemolyticus also changed, the most prevalent was O4:K4 in 1989, O4:K8 in both 1990 and 1991, O1:K56 in 1992, and O4:K8 from 1993 through 1995. Serotype O3:K6 became the most prevalent in 1996 and has remained so to date. In addition, the new serotype O4:K68 had also appeared in 1998. The number of outbreaks due to serotype O4:K68 followed that of O3:K6. Thus, the trends of V. parahaemolyticus foodborne outbreaks during the last 12 years in Tokyo showed various characteristics and dramatic changes in causal organisms.

A novel cryoprotective protein (CRP) with high activity from the ice-nucleating bacterium, Pantoea agglomerans IFO12686

The ice-nucleating bacterium, Pantoea agglomerans IFO12686, induces the cryoprotective protein (CRP) by cold acclimation at 12 degrees C. The CRP was purified to apparent homogeneity by various chromatographies. We found that the purified CRP was a monomer of approximately 29,000 according to gel filtration chromatography and SDS-PAGE, and was a heat-stable protein. The CRP could protect freeze-labile enzymes, lactate dehydrogenase (LDH), alcohol dehydrogenase (ADH) and isocitrate dehydrogenase (iCDH), against freezing-thawing denaturation. The activity of the CRP was about 3.5 x 10(4) times more effective than bovine serum albumin (BSA) and 2 x 10(6) times than COR26 from the ice-nucleating bacterium Pseudomonas fluorescens KUIN-1. We confirmed that the CRP was a novel protein, as judged by the a different molecule mass from the already-known cryoprotectants, and has an extremely high cryoprotective activity.

Twenty-seven-year follow-up of arrhythmogenic right ventricular dysplasia

This case report describes clinical features, especially of surface ECG changes, observed for 27 years in a patient with arrhythmogenic right ventricular dysplasia (ARVD). The course of this patient was characterized by progressive deterioration of right ventricular function and progression of delayed potentials (so-called epsilon waves) following QRS complexes. However, the relation between ventricular arrhythmias and ECG changes or the degree of right ventricular abnormality was difficult to discern.

Antiallodynic effect of intrathecally administered 5-HT(2) agonists in rats with nerve ligation

We examined the antiallodynic effect of intrathecally administered serotonin receptor agonists including 5-HT(1A), 5-HT(1B), 5-HT(2) and 5-HT(3) receptor subtypes in a rat model using spinal nerve ligation at L5 and L6. Administration of the 5-HT(2) receptor agonist, alpha-methyl-5-hydroxytryptamine maleate (alpha-m-5-HT; 3-100 microg) or (+/-)-1-(4-iodo-2,5-dimethoxyphenyl)-2-aminopropane hydrochloride (DOI; 10-100 microg), showed dose-dependent antiallodynic actions with no associated motor weakness. The antiallodynic action of alpha-m-5-HT was more potent than that of DOI. The effects of 5-HT(2) agonists on tactile allodynia were reversed by intrathecal pretreatment with the selective 5-HT(2) antagonist ketanserin and with the mixed 5-HT(1) and 5-HT(2) antagonist methysergide. Neither the mixed 5-HT(1A) and 5-HT(1B) antagonist cyanopindolol nor the selective 5-HT(3) antagonist MDL72222 attenuated antiallodynic effects induced by 5-HT(2) agonists. In contrast, the selective 5-HT(1A) agonist 8-hydroxy-2-(di-n-propylamino)-tetralin hydrobromide (8-OH-DPAT; 1-50 microg), the 5-HT(1B) agonist 5-methoxy-3-(1,2,5,6-tetrahydro-4-pyridinil)-1H-indol (RU-24969; 10-100 microg) and the 5-HT(3) agonist 2-methyl-5-hydroxytryptamine maleate (2-m-5-HT; 30-300 microg) all lacked significant antiallodynic action with intrathecal administration. These results indicate that the 5-HT(2) receptor plays an essential role in spinal suppression of neuropathic pain by 5-HT.

[Minimally invasive direct coronary artery bypass grafting using subxiphoid approach]

We report twelve cases of minimally invasive coronary artery bypass grafting via small laparotomy using right gastroepiploic artery (RGEA) to the right coronary artery. Seven patients were operated on without partial sternotomy (N group), and lower partial sternotomy with Octopus 2 stabilization system was used in five of the cases (P group). Postoperative Doppler echographic imaging or angiographic study showed all RGEA grafts were functioning well in P group. However, graft occlusion was observed in two of the cases in N group. Inferior partial sternotomy combined with Octopus 2 stabilization system produce a clear surgical view, which avoids of both full-sternotomy and cardiopulmonary bypass. This method might be useful especially for reoperation.

Identification of a compound in Chamaecyparis taiwanensis inhibiting the ice-nucleating activity of Pseudomonas fluorescens KUIN-1

Inactivation of the ice-nucleating activity of Pseudomonas fluorescens KUIN-1 by compounds in the leaves from coniferous trees were investigated, and the inactivated material was identified. Intact cells of the strain KUIN-1 and the acetone or methanol extracts of leaves of various coniferous trees were allowed to react for 30 min at 18 degrees C. Antinucleation compounds were obtained from Chamaecyparis taiwanensis. When the acetone extract from the leaves of coniferous trees was added to the cell suspension (about 10(6) cells/ml) in 50 mM potassium phosphate buffer (pH 7.0), the ice nucleating temperature, T50, was significantly decreased (T50 < -5 degrees C). This inhibitor was isolated by using TLC, then identified as hinokitiol based on UV-VIS, IR, and mass spectral data. When intact cells of the strain KUIN-1 were incubated with hinokitiol, limonene, and alpha-pinene of the principal constituent of the leaves of coniferous trees in 50 mM potassium phosphate buffer (pH 7.0), the ice-nucleating activity decreased, but not in alpha-terpinene. Furthermore, the ice-nucleating activities from other ice-nucleating bacteria also decreased in the presence of hinokitiol. This inhibition was proportional to the concentration of hinokitinol. The pH and thermal stabilities of the ice-nucleating activity of the cells were changed by the addition of hinokitiol (10 mM).

The comparative effects of propofol versus thiopental on middle cerebral artery blood flow velocity during electroconvulsive therapy

Electroconvulsive therapy provokes abrupt changes in both systemic and cerebral hemodynamics. An anesthetic that has a minor effect on cerebral hemodynamics might be more suitable for patients with intracranial complications, such as cerebral aneurysm. The purpose of our present study was to compare the effects of thiopental and propofol on cerebral blood flow velocity. We continuously compared cerebral blood flow velocity at the middle cerebral artery (MCA) during electroconvulsive therapy, using propofol (1 mg/kg, n = 20) versus thiopental (2 mg/kg, n = 20) anesthesia. Systemic hemodynamic variables and flow velocity at the MCA were measured until 10 min after the electrical shock. Heart rate and arterial blood pressure increased in the thiopental group until 5 min after the electrical shock. In the propofol group, an increase in mean blood pressure was observed to 1 min after the electrical shock. Mean flow velocity at the MCA decreased after anesthesia in both groups, and increased at 0.5-3 min after the electrical shock in the thiopental group and at 0.5 and 1 min after the shock in the propofol group. The flow velocities at 0.5-5 min after the electrical shock were significantly more rapid in the thiopental group compared with the propofol group. ¿abs¿

IMPLICATIONS

Cerebral blood flow velocity change, measured by transcranial Doppler sonography during electroconvulsive therapy, was minor using propofol anesthesia compared with barbiturate anesthesia. Propofol anesthesia may be suitable for patients who cannot tolerate abrupt cerebral hemodynamic change.

A cold acclimation protein with refolding activity on frozen denatured enzymes

We found that a cold acclimation protein from an ice-nucleating bacterium, Patoea ananas KUIN-3, has refolding activity on frozen denatured protein. Based on a SDS-PAGE analysis, we confirmed that the cold shock-treated cells of strain KUIN-3 could produce some cold acclimation proteins that inhibit their syntheses by the addition of chloramphenicol during the cold acclimation. Among such proteins, Hsc25 had refolding activity similar to GroELS. Hsc25 was purified to apparent homogeneity by (NH4)2SO4 precipitation and some chromatographies. The purified Hsc25 was composed of 8 subunits of 25,000 each with a molecular mass of 200,000 and had refolding activity against denatured enzymes, which were denatured by heat-treatment at 100 degrees C, cryopreservation at -20 degrees C, or guanidine hydrochloride, in a manner similar to GroELS. The N-terminal sequence of Hsc25 was Met-Arg-Ala-Ser-Thr-Tyr-His-Ala-Ala-Arg-. Furthermore, Hsc25 had a high level of activity at low temperature (12 degrees C). Also, the dissociation constants, KD (M) as the binding specificity for enolase, mutarotase, isocitrate dehydrogenase, and lactate dehydrogenase were 1.82x10(-10), 4.35x10(-9), 8.98x10(-12), and 3.05x10(-11), respectively. The affinity of Hsc25 for frozen danatured enzymes was higher than the affinity for heat denatured enzymes when compared with the affinity of GroEL. These results are the first report on the characterization of a purified chaperon that was induced by cold acclimation.

A novel human HER2-derived peptide homologous to the mouse K(d)-restricted tumor rejection antigen can induce HLA-A24-restricted cytotoxic T lymphocytes in ovarian cancer patients and healthy individuals

A mouse HER2-derived peptide, HER2p63 (A) (TYLPANASL), can induce K(d)-restricted mouse cytotoxic T lymphocytes (CTL) and also function as a tumor rejection antigen in an in vivo assay. Since the anchor motif of mouse K(d) for peptide binding has much similarity to that of human HLA-A2402, we asked if human HER2p63 (T) (TYLPTNASL) could induce HER2-specific CTL in HLA-A2402-positive individuals. Peripheral blood mononuclear cells (PBMC) of HLA-A2402-positive individuals were sensitized in vitro with HER2p63-pulsed autologous dendritic cells prepared from PBMC. CTL clone derived from these specifically lysed HER2-expressing cell lines bearing HLA-A2402. Cytotoxic activity of the CTL clone against the HER2-expressing cell line bearing HLA-A2402 was blocked by antibodies against CD3, CD8, HLA-A24 or MHC class I, and was also inhibited by the addition of excess HER2p63-pulsed C1R bearing HLA-A2402. Killer cells were generated from PBMC of seven healthy individuals and five ovarian cancer patients, all of HLA-A2402 type, by in vitro sensitization with HER2p63-pulsed autologous antigen presenting cells. These killer cells selectively lysed HER2-expressing SKOV3 transfected with HLA-A2402 cDNA, indicating high immunogenicity of HER2p63 in all 12 individuals examined.

Characterization and properties of intracellular proteins after cold acclimation of the ice-nucleating bacterium Pantoea agglomerans (Erwinia herbicola) IFO12686

The ice-nucleating bacterium Pantoea agglomerans (Erwinia herbicola) IFO12686 (INA(+)) responds to a decrease in temperature by the induction of proteins. The pattern of protein bands from strain IFO12686 following a shift in temperature from 30 to 12 degrees C could be divided into four major groups: (1) increasing protein bands, (2) decreasing protein bands, (3) increasing--decreasing protein bands, and (4) almost constant protein bands. We identified a cryoprotective function in the increasing protein band found in strain IFO12686. The increasing protein bands that followed a reduction in temperature were considered to have an important role in cold acclimation or adaptation. We showed that these proteins possessed cryoprotective activity when tested against the freeze-labile enzyme lactate dehydrogenase. The strain IFO12686 had greater cryotolerance than Pa. agglomerans IAM1595 (INA(-)), and the degree of cryotolerance was increased by cold acclimation.

Occupational asthma due to exposure to African cherry (Makore) wood dust

A 35-year-old man who had been a carpenter and a cabinet worker for over 15 years, was referred to our clinic with a 4-month history of cough, chest tightness and difficulty in breathing which occurred within minutes of exposure to African cherry wood (Makore). He developed a dual asthmatic reaction on specific challenge test with an extract of African cherry wood dust. Thus, the diagnosis of occupational asthma due to exposure to African cherry wood dust was confirmed by the specific challenge test. The mechanism of asthma due to African cherry wood dust exposure is not clear.

Antinociception in rat by sarpogrelate, a selective 5-HT(2A) receptor antagonist, is peripheral

The antinociceptive effect of sarpogrelate, a new selective 5-hydroxytriptamine (5-HT)(2A) receptor antagonist, in the formalin test was examined in rats. Sarpogrelate was administered intraperitoneally, locally (subcutaneously at the formalin test site) or intrathecally 10 min before formalin injection. Intraperitoneal (1-100 mg/kg) and local (0.01-1 mg) administration of sarpogrelate suppressed flinching behavior in both phases 1 (0-9 min) and 2 (10-60 min) in a dose-dependent manner. Intraperitoneal (100 mg/kg) and local (1 mg) injection 7 min after formalin injection reduced phase 2 flinches to the same degree as with the pre-treatment. Intrathecal administration (1-100 microg) showed no antinociceptive action, and facilitated phase 2 flinches at 10 microg. The plasma concentration of sarpogrelate after local administration of 1 mg was lower than after intraperitoneal administration of 10 mg/kg, although local administration produced more potent antinociception. The data imply that the antinociceptive effect of sarpogrelate results mainly from an action at peripheral sites.

Reduction of cerebral hyperemia with anti-hypertensive medication after electroconvulsive therapy

PURPOSE

Several different anti-hypertensive regimens have been introduced for the prevention of systemic hyperdynamic responses after electrically induced seizures. In the present study, the effects of anti-hypertensive medications on cerebral circulation were studied.

METHODS

Systemic blood pressure was controlled by several anti-hypertensive medications, nicardipine, prostaglandin EI, alprenolol and nitroglycerin, in 30 patients (150 electroconvulsive therapy trials). Changes in cerebral blood flow velocity were measured by transcranial Doppler sonography of the right middle cerebral artery from the start of anesthesia to 10 min after the electrical shock.

RESULTS

Administration of a Ca2+ antagonist, nicardipine, or prostaglandin EI did not alter the augmented cerebral blood flow velocity after the seizure. However, a beta-adrenergic blocking agent, alprenolol (P<0.05) or nitroglycerin (P<0.01) partially inhibited the increase in cerebral blood flow velocity. Maximal blood flow velocity was 133% larger than the pre-anesthesia value in the control group, 109% in the nicardipine group, 113% in the prostaglandin EI group, 72% in the alprenolol group, and 45% in the nitroglycerin group, respectively. The increase in cerebral blood flow velocity after electrically induced seizure was independent of systemic blood pressure. Internal jugular venous saturation (SjO2) was increased, and difference in arterial and venous concentrations of lactate was not altered in all groups.

CONCLUSIONS

Cerebral hemodynamics is altered by ECT, even when systemic hemodynamics are stabilized by antihypertensive medication. Although the effects of antihypertensive medicine on cerebral hemodynamics are variable, systemic blood pressure control by these agents does not induce cerebral ischemia after ECT.

[A recurrent case of amebic liver abscess seventeen years after the first occurrence]

A 49-year-old male who had been diagnosed as having amebic liver abscess when he was 32-year-old was admitted to our hospital with fever and watery diarrhea. Ultrasonography and CT examination demonstrated a solitary abscess in the right lobe of the liver. Cysts of Entamoeba histolytica were detected in the stool and an aspiration of the liver abscess looked like anchovy paste. Serum amebic antibody by the IFA method was positive and the case was diagnosed as amebic liver abscess. The patient was treated with metronidazole, and percutaneous transhepatic abscess drainage was performed. The liver abscess decreased remarkably in size and serum amebic antibody was negative after the treatment. Recurrence of amebic liver abscess is rare and we report this case with some literature.

Isolation of two different phenotypes of mycorrhizal mutants in the model legume plant Lotus japonicus after EMS-treatment

Lotus japonicus has been proposed as a model plant for the molecular genetic study of plant-microbe interaction including Mesorhizobium loti and arbuscular mycorrhizal (AM) fungi. Non-mycorrhizal mutants of Lotus japonicus were screened from a collection of 12 mutants showing non-nodulating (Nod-), ineffectively nodulating (Fix-) and hypernodulating (Nod++) phenotypes with monogenic recessive inheritance induced by EMS (ethylmethane sulfonate) mutagenesis. Three mycorrhizal mutant lines showing highly reduced arbuscular mycorrhizal colonization were obtained. All of them were derived from Nod- phenotypes. In Ljsym72, the root colonization by Glomus sp. R-10 is characterized by poor development of the external mycelium, formation of extremely branched appressoria, and the blocking of hyphal penetration at the root epidermis. Neither arbuscules nor vesicles were formed in Ljsym72 roots. Fungal recognition on the root surface was strongly affected by the mutation in the LjSym72 gene. Unique characteristics in mutant lines Ljsym71-1 and Ljsym71-2 were the overproduction of deformed appressoria and arrested hyphal penetration of the exodermis. Small amounts of internal colonization including degenerated arbuscule formation occurred infrequently in these types of mutants. Not only fungal development on the root surface but also that in the root exodermis and cortex was affected by the mutation in LjSym71 gene. These mutants represent a key advance in molecular research on the AM symbiosis.

[Aortic valve replacement with a stentless porcine aortic root bioprosthesis]

From April, 1999 to November, 1999, 8 patients underwent the aortic valve replacement using Medtronic Freestyle aortic root bioprosthesis. Mean age was 67.8 years old. Aortic valve etiology was as follows, AS: 1 case, AR: 2 cases, ASR: 3 cases, IE: 1 case, mechanical valve malfunction due to subvalvular pannus: 1 case. The implanted valve size was 25: 2 cases, 23: 3 cases, 21: 1 cases, 19: 2 cases. Surgical technique was subcoronary: 7 cases, full-root: 1 case. Post-op 2D-echo revealed tribial aortic valve incompetence in two cases because of size discrepancy between the aortic annulus and the ascending aorta. Pacemaker implantation was needed in 1 case because of the complete A-V block. In comparison with 5 cases of aortic valve replacement with Hancock II performed in same period, there were no significant differences about the implanted valve size and mean systolic pressure gradient, but the effective orifice area in Freestyle cases was significantly larger than Hancock II cases.

Effect of anti-inflammatory agents on corneal wound-healing process after surface excimer laser keratectomy

PURPOSE

To investigate the effect of anti-inflammatory agents on conjunctival inflammation and corneal haze formation after excimer laser keratectomy.

SETTING

Department of Ophthalmology, University of Tokyo Faculty of Medicine, Tokyo, Japan.

METHODS

After excimer laser keratectomy was performed in 21 rabbits (42 eyes), saline, betamethasone 0.1%, or diclofenac 0.1% was topically applied 6 times a day for 4 weeks and then 3 times a day for 8 weeks. The degree of conjunctival inflammation was determined 1, 2, 3, and 7 days after the keratectomy. The degree of corneal haze was quantitatively measured using a digital analyzer before and once a week after the keratectomy. The expression of type IV collagen in the corneas at baseline and 4 and 12 weeks after the keratectomy was examined immunohistochemically.

RESULTS

Compared with saline, betamethasone and diclofenac significantly decreased early-phase conjunctival inflammation. Betamethasone significantly inhibited corneal haze formation compared with saline at 3 to 5 and 8 to 12 weeks. Diclofenac did not inhibit corneal haze formation significantly. Although betamethasone tended to be more effective in inhibiting corneal haze formation and deposition of type IV collagen than diclofenac, there was no statistical difference between the 2 anti-inflammatory agents.

CONCLUSION

Topically applied betamethasone effectively suppressed corneal haze formation after excimer laser keratectomy. Diclofenac was not statistically effective in inhibiting corneal haze formation.

Analysis of liquid accumulated in the distended capsular bag in early postoperative capsular block syndrome

PURPOSE

To analyze the transparent liquid between the posterior lens capsule and the posterior chamber intraocular lens (PC IOL) in early postoperative capsular block syndrome and discuss the mechanism of posterior capsule distention.

SETTING

Department of Ophthalmology, Tokyo University School of Medicine, and Tokyo Research Institute, Seikagaku Corporation, Tokyo, Japan.

METHODS

This study evaluated 3 cases of capsular block syndrome presenting with transparent liquid in the distended capsular bag 1 day after cataract surgery. The transparent liquid material between the posterior capsule and PC IOL was aspirated and analyzed using high-performance liquid chromatography (HPLC). Also, sodium hyaluronate was diluted using a dialyzer to determine whether the aqueous humor was drawn into the capsular bag by an osmotic gradient across the capsule.

RESULTS

The elution time of the samples was almost the same as that of sodium hyaluronate 1.0% (Healon) The concentration of the samples ranged from 3.29 to 9. 01 mg/mL by HPLC analysis. The sodium hyaluronate absorbed the physiological salt solutions through the dialyzer and expanded to 1. 9 times its original volume.

CONCLUSIONS

These results indicate that the main ingredient of the transparent liquid in capsular bags is sodium hyaluronate and that the distention is caused by aqueous humor being drawn into the capsular bag by an osmotic gradient across the capsule when the capsulorhexis diameter is smaller than that of the PC IOL and by viscoelastic material retained and trapped in the bag intraoperatively.

Serum total bile acid level as a sensitive indicator of hepatic histological improvement in chronic hepatitis C patients responding to interferon treatment

BACKGROUND AND METHODS

Serum total bile acid (TBA) levels are used clinically as a sensitive and reliable index of hepatobiliary diseases. In the present study, to assess the clinical usefulness of determining TBA in interferon (IFN)-treated patients, changes in liver function test values, including TBA and liver histology, were examined in 36 chronic hepatitis C patients for 3 years after a sustained response to IFN treatment.

RESULTS

Alanine aminotransferase and gamma-glutamyl transpeptidase values significantly decreased during the period of IFN treatment compared to the same measures before IFN treatment. Albumin, cholinesterase, total cholesterol and platelet count values temporarily decreased during IFN treatment, then increased significantly and reached a plateau 6-12 months after the end of IFN treatment. The zinc sulphate turbidity test and TBA values began to decrease during IFN treatment and continued to decrease during the 3-year follow-up period. The histological activity index of the liver (Knodell's score) significantly decreased, whereas the staging score was unchanged 1 year after the end of IFN treatment. In patients who had a TBA value > 10 micromol/L before IFN treatment, a significant correlation was observed between the decrease of TBA and liver histology grading score.

CONCLUSIONS

A decrease in serum TBA level reflected histological improvement in the liver more precisely than did changes in the other liver function test values following IFN therapy.

Accuracy of carboxyhemoglobin dilution method for the measurement of circulating blood volume

PURPOSE

The management of circulating blood volume (BVc) is crucial in intensive care unit (ICU) patients. The purpose of this study was to verify the accuracy and precision of the carbon monoxide-labeled hemoglobin (CO-Hb) dilution method (CO method) by comparing it with the 51Cr-labeled erythrocyte dilution method (51Cr method) for the measurement of BVc.

METHODS

A prospective study was performed in 18 patients who underwent coronary artery bypass grafting (CABG) under mild hypothermic cardiopulmonary bypass (CPB). The BVc was measured by both the CO method and the 51Cr method at 24 hr after ICU admission in order to verify the accuracy and precision of the CO method. Paired data were assessed in absolute terms, and percentage errors were calculated by the degree of agreement.

RESULTS

Small mean differences and standard deviations between the CO method and the 51Cr method (-70.2 +/-184.8 mL) and small percentage errors (-0.49+/-1.29%) indicated the accuracy and precision of the CO method, and a close correlation was observed (r = 0.97).

CONCLUSION

The CO method can measure BVc with a similar degree of accuracy as the 51Cr method. It is simple, repeatable and safe without the risk of exposure to radioactivity in the ICU.

Epidural block with mepivacaine before surgery reduces long-term post-thoracotomy pain

PURPOSE

To examine the effect of continuous epidural block initiated before thoracic surgery upon early and long-term postoperative pain.

METHODS

In a double-blind study, 70 patients scheduled for thoracic surgery under general anesthesia were assigned randomly to receive continuous epidural block with mepivacaine 1.5% initiated either 20 min before surgical incision (Pre group) or at completion of surgery (Post group). In both groups the initial dose was 4 ml, followed by a continuous infusion at 4 ml x hr(-1) until 72 hr after operation. Indomethacin suppositories, 50 mg, were administered on request as supplementary analgesics. Visual analogue scale at rest was assessed four hours after operation, and then every 24 hr after operation on postoperative days 1 through 7, and also days 14 and 30. At three and six months after operation, all patients were interviewed by telephone with respect to postoperative pain. The most severe pain was assessed using modified numerical rating scale.

RESULTS

By a visual analogue scale, postoperative pain was less in the Pre group than in the Post group at four hours, two and three days after operation (P < 0.05). By a numerical rating scale six months after operation, pain was less in the Pre group than in the Post group (P = 0.015). The percentage of pain-free patients was higher in the Pre group than in the Post group at three (P = 0.035) and six (P = 0.0086) months after operation.

CONCLUSION

Continuous epidural block initiated prior to surgery may reduce long-term post-thoracotomy pain.

Steady-state inhibitory kinetic studies on the ligand binding modes of Aspergillus niger glucoamylase

Inhibitory activities of 1-deoxynojirimycin and gluconolactone on Aspergillus niger glucoamylase were studied in relation to the subsite structure of the enzyme. Although both of these inhibitors are considered to bind at subsite 1 of the enzyme active site, 1-deoxynojirimycin showed competitive type inhibition but gluconolactone was a mixed type (or noncompetitive type) inhibitor for the hydrolysis of p-nitrophenyl alpha-D-glucoside. The former type of inhibition suggested that the main binding mode of the substrate was productive, but the latter, nonproductive. A possible way of explaining these apparent inconsistent results is to assume that the main binding mode of the substrate is productive and gluconolactone forms a nonproductive ternary complex with the enzyme and the substrate.

Intrathecal co-administration of NMDA antagonist and NK-1 antagonist reduces MAC of isoflurane in rats

BACKGROUND

Intravenous administration of N-methyl-D-aspartate (NMDA) receptor antagonists and alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptor antagonists reportedly reduce the minimum alveolar anaesthetic concentration (MAC) for inhalation anaesthetics. If pain perception can be prevented by the intrathecal administration of antinociceptive receptor antagonists, these agents may reduce the requirements for inhalation anaesthetics. We studied the effect of intrathecal administration of an AMPA/kainate receptor antagonist, a metabotropic glutamate (mGlu) receptor antagonist and co-administration of NMDA and a neurokinin-1(NK-1) receptor antagonist drugs at low doses on the MAC.

METHODS

After Wistar rats (n=36) were fitted with indwelling intrathecal catheters, the MAC of isoflurane was determined following intrathecal administration of a non-NMDA receptor antagonist (CNQX) at 10 microg, a mGlu receptor antagonist (AP3) at 10 microg, or a combination of NMDA receptor antagonist (APV) at 0.01 microg to 1 microg with NK-1 receptor antagonist (CP96345, CP) at 0.1 microg to 10 microg. Subsequently, a reversal dose of intrathecal NMDA with substance P (SP) was administered, and the MAC of isoflurane was redetermined. Conscious rats (n=15) were also examined for the presence of locomotor dysfunction following the intrathecal co-administration of APV and CP.

RESULTS

Neither CNQX nor AP3 reduced the MAC of isoflurane. APV at 0.01 microg plus CP at 1 microg, as well as APV at 0.1 microg plus CP at 10 microg, reduced the MAC of isoflurane, with respective reductions of 7.6% and 14%; (P<0.05). Co-administration of NMDA plus SP reversed the decrease in the MAC of isoflurane. Locomotive activity was not changed.

CONCLUSIONS

The NMDA receptor and the NK-1 receptor are important determinants of the MAC of isoflurane, exerting this influence by inhibition of pain transmission in the spinal cord, while mGlu and AMPA receptors have no effect on the MAC of isoflurane.