Linkage-Editing Pseudo-Glycans: A Reductive α-Fluorovinyl-C-Glycosylation Strategy to Create Glycan Analogs with Altered Biological Activities

The acetal (O-glycoside) bonds of glycans and glycoconjugates are chemically and biologically vulnerable, and therefore C-glycosides are of interest as more stable analogs. We hypothesized that, if the O-glycoside linkage plays a vital role in glycan function, the biological activities of C-glycoside analogs would vary depending on their substituents. Based on this idea, we adopted a "linkage-editing strategy" for the creation of glycan analogs (pseudo-glycans). We designed three types of pseudo-glycans with CH2 and CHF linkages, which resemble the O-glycoside linkage in terms of bond lengths, angles, and bulkiness, and synthesized them efficiently by means of fluorovinyl C-glycosylation and selective hydrogenation reactions. Application of this strategy to isomaltose (IM), an inducer of amylase expression, and α-GalCer, which activates iNKT cells, resulted in the discovery of CH2-IM, which shows increased amylase production ability, and CHF-α-GalCer, which shows activity opposite that of native α-GalCer, serving as an antagonist of iNKT cells.

Heterogeneous carotid plaque is associated with cardiovascular events after percutaneous coronary intervention

Background

The relationship between carotid artery ultrasound findings and clinical outcomes in percutaneous coronary intervention (PCI) patients has not been fully elucidated.

Purpose

To investigate the relationship between carotid artery ultrasound findings and cardiovascular risks in PCI patients.

Methods

This was a single-center retrospective study investigating 691 patients who underwent PCI and carotid ultrasound testing. Maximum carotid intima-media thickness (CIMT) was defined as the greatest CIMT at the maximally thick point among the common carotid artery, carotid bulb, and internal carotid artery. A carotid plaque was defined as vessel wall thickening with a CIMT ≥1.5 mm. The characteristics of carotid plaque (heterogeneity, calcification, or irregular/ulcerated surface) were evaluated visually. Patients were divided into those with and without heterogeneous carotid plaque (maximum CIMT ≥1.5 mm and heterogeneous texture). The endpoint was the incidence of a major adverse cardiovascular event (MACE) defined as a composite of cardiovascular death, myocardial infarction, and ischemic stroke.

Results

Among 691 patients, 312 were categorized as having a heterogeneous plaque. Patients with heterogeneous plaques were at a higher risk of MACE than those without (p=0.002). A heterogeneous plaque was independently associated with MACE after adjusting for covariates (hazard ratio [HR], 1.80; 95% confidence interval [CI], 1.06–3.04; p=0.03). Calcified or irregular/ulcerated plaques were correlated with a higher incidence of MACE but both were not independently associated with MACE (HR, 1.37; 95% CI, 0.70–2.67, p=0.36 and HR, 1.13; 95% CI, 0.66–1.93; p=0.66, respectively).

Conclusions

The presence of a heterogeneous carotid plaque in patients who underwent PCI predicted future cardiovascular events. These patients may require more aggressive medical therapy and careful follow-up.

Funding Acknowledgement

Type of funding sources: None.

P856Incidence and Outcomes of irregular protrusion after stent implantation in patients with acute myocardial infarction: An in in vivo optical coherence tomography study

Background

Irregular protrusion, a protrusion of material with an irregular surface into the lumen of the vessel after stent implantation, can only be identified by optical coherence tomography (OCT). A previous study demonstrated that irregular protrusion after stent implantation was an independent predictor of 1-year major adverse cardiac events (MACE) in CAD patients. However, the true incidence and prognostic significance of irregular protrusion after stenting in patients with ST-segment elevation myocardial infarction (STEMI) have not previously examined.

Aims

The aims of this study were the following: 1) to evaluate the incidence of irregular protrusion detected by OCT in STEMI patients after stenting; and 2) to compare the long-term outcomes between patients with and without irregular protrusion.

Methods and results

A total of 210 STEMI patients who had post-procedure OCT imaging after coronary stenting within 12 hours after symptom onset were studied. We divided them into two groups: those with irregular protrusion (n=159) and those without (n=51) after stenting. There were no significant differences in baseline characteristics between the 2 groups except that peak CK-MB levels were higher in patients with irregular protrusion than those without (289 (137–563) vs. 260 (63–349) U/L, p<0.05). During mean follow-up period of 298 days, the overall incidence of MACE defined as cardiac death, target vessel-related myocardial infarction, and target lesion revascularization was 15.3%. Kaplan-Meier curve showed that the incidence of MACE did not differ between patients with and without irregular protrusion (14.7% vs. 17.7%, p=0.53 by Log-rank).

Conclusions

Irregular protrusion after stent implantation was detected in three-fourth of STEMI patients. Although patients with irregular protrusion had a greater myocardial damage, it did not influence clinical outcomes.

Acknowledgement/Funding

Donation course from Abbott Japan

P1624Blockade of protease activated receptor-1 signaling attenuates cardiac hypertrophy and fibrosis in renin-overexpressing hypertensive mice

Introduction

Recent evidences have demonstrated that coagulation pathway is involved in cardiovascular remodeling induced by renin-angiotensin system (RAS), which finally leads to heart failure. Protease activated receptor-1 (PAR-1) is widely expressed in the vasculature and the heart, and plays important roles in pro-inflammatory process in the cardiovascular system. Recently, we demonstrated that the activity of factor Xa (FXa), which functions not only as a coagulation factor but as an agonist for PAR-1, was enhanced in renin-overexpressing hypertensive mice (Ren-Tg).

Purpose

The purpose of this study was to investigate whether inhibition of PAR-1 signaling has protective effects on the progression of heart failure induced by chronic RAS activation in Ren-Tg.

Methods and results

We treated 12–16 weeks-old male wild type mice (WT) and Ren-Tg with continuous subcutaneous infusion of PAR-1 antagonist SCH79797 (25mg/kg/day) or vehicle for 4 weeks. After treatment period, left ventricular (LV) wall thickness calculated as interventricular septum plus posterior wall thickness measured by echocardiography was greater in Ren-Tg than in WT (0.25±0.003 versus 0.18±0.002 mm), and SCH79797 attenuated the increase to 0.22±0.01 mm in Ren-Tg (both p<0.05, respectively). The ratio of heart weight to body weight was greater in Ren-Tg than in WT (6.1±0.4 versus 4.6±0.7 mg/g), and SCH79797 attenuated the increase to 5.2±0.1 mg/g (both p<0.05). The area of cardiac fibrosis evaluated by Masson-trichrome staining was greater in Ren-Tg than in WT (2.6±0.2 versus 1.4±0.3%), and SCH79797 attenuated it to 1.6±0.3% in Ren-Tg (both p<0.05). Cardiac mRNA expressions of tumor necrosis factor-α, transforming growth factor-β1, and β-myosin heavy chain were all greater in Ren-Tg than in WT, and SCH79797 attenuated the increases in Ren-Tg (all p<0.05).

Conclusions

Inhibition of PAR-1 signaling attenuates cardiac hypertrophy and fibrosis in Ren-Tg via inhibition of inflammatory cytokines production. These results support the involvement of PAR signaling in the development of heart failure induced by RAS, and may provide novel therapeutic insights for the treatment of hypertensive heart failure.

The pilot study: sphingomyelin-fortified milk has a positive association with the neurobehavioural development of very low birth weight infants during infancy, randomized control trial

AIM

This study was a randomised control trial to examine the effects of sphingomyelin (SM), on the mental, motor and behavioural development of premature infants.

PATIENTS AND METHODS

Randomised, double-blind controlled trial, enroling infants born with a birth weight of less than 1500 g between January 2004 and October 2007 at Juntendo University Hospital, with follow-up to 18 months. Twenty-four preterm babies were randomly assigned; 12 were assigned to a test group and fed SM-fortified milk (SM 20% of all phospholipids in milk) and 12 were assigned to a control group (SM 13% of all phospholipids in milk). We analysed the composition of the plasma phospholipids and red-cell-membrane fatty acids, after which VEP, Fagan, BSID-II, attention and memory tests were performed.

RESULTS

The percentage of SM in the total phospholipids was significantly higher in the trial group than in the control group at 4, 6 and 8 weeks. The Behaviour Rating Scale of the BSID-II, the Fagan test scores, the latency of VEP, and sustained attention test scores at 18 months were all significantly better in the trial group than in the control group.

CONCLUSION

This study is the first to report that nutritional intervention via administration of SM-fortified milk has a positive association with the neurobehavioural development of low-birth-weight infants. However, detailed studies on the effects of SM on longer-term development are required.

Greater fat oxidation with diacylglycerol oil consumption for 14 days compared with triacylglycerol oil consumption in overweight men and women

BACKGROUND

Several studies have reported increased fat oxidation with diacylglycerol (DAG) oil consumption. However, the effects of long-term DAG oil consumption on energy metabolism remain to be investigated.

OBJECTIVE

The objective of this study was to compare the effects of 14 days of either DAG or triacylglycerol (TAG) oil consumption on substrate oxidation, energy expenditure (EE) and dietary fat oxidation.

DESIGN

Eight males and six females participated in this randomized, double-blind, crossover feeding study. Each patient consumed the 14-day controlled test diet containing either 10 g day(-1) of DAG or TAG oil for acclimatization before a respiratory chamber measurement, followed by a 2-week washout period between diet treatments. Substrate oxidation and EE were measured in the respiratory chamber at the end of each dietary treatment. The patients consumed test oil as 15% of total caloric intake in the respiratory chamber (mean test oil intake was 36.1+/-6.6 g day(-1)).

RESULTS

Twenty-four hour fat oxidation was significantly greater with 14 days of DAG oil consumption compared with TAG oil consumption (78.6+/-19.6 and 72.6+/-14.9 g day(-1), respectively, P<0.05). There were no differences in body weight or body composition between diet treatments. Dietary fat oxidation was determined using the recovery rate of (13)CO(2) in breath, and was significantly enhanced with DAG oil consumption compared with TAG oil consumption, measured over 22 h after ingestion of (13)C-labelled triolein. Resting metabolic rate (RMR) was significantly greater with DAG oil consumption compared with TAG oil consumption (1766+/-337 and 1680+/-316 kcal day(-1), respectively, P<0.05).

CONCLUSION

Consumption of DAG oil for 14 days stimulates both fat oxidation and RMR compared with TAG oil consumption, which may explain the greater loss of body weight and body fat with DAG oil consumption that has been observed in weight-loss studies.

Simulation of exercise-dependent difference in metabolism with a mathematical model for analyses of measurements using near-infrared spectroscopy

Near-infrared spectroscopy (NIRS) is a useful technique for noninvasive measurement of muscle oxygenation. However, analyses of the dynamic changes in muscle metabolism based only on experimental observations of NIRS are difficult. Therefore, we constructed a mathematical model of muscle metabolism, comprising of the ATP synthesizing systems and O2 diffusion system, to identify the mechanisms responsible for those observations. A customized NIRS instrument was used to measure the changes in muscle oxygenation of the forearm flexor muscles during intermittent and continuous isometric flexion exercises when healthy male subjects participated in exercises tests. The exercise-dependent difference in changes could be distinguished and the simulated results agreed well with that measured experimentally. Although the contraction intensity for both exercises was identical, the magnitude of energy needed to perform the respective exercises was different. This difference was reflected by the changes in the ATP synthesizing systems, in which the energy needed during the latter-half of continuous exercise was mostly supplied by anaerobic system, whereas that during intermittent exercise was supplied by the aerobic and anaerobic systems that operated synergistically. From the results, we conclude that the model could be a useful tool for the elucidation of the relationship between experimental observations of NIRS and muscle metabolism.

Imaging of Regional Differences of Muscle Oxygenation during Exercise Using Spatially Resolved NIRS

The development of imaging systems using near-infrared spectroscopy (NIRS) has enabled noninvasive measurement of regional changes in muscle oxygenation. A spatially resolved NIRS (SR-NIRS) imaging instrument was utilized for real-time measurement of spatial-temporal changes in muscle oxygenation during exercises. Changes in muscle oxygenation and localized O<inf>2</inf>consumption in the quadriceps muscle were measured during sustained isometric knee extension without and with leg-press to the ground exercises. In the former exercise, the level of tissue oxygen saturation (TOS) of the rectus femoris (RF) muscle was found to be lower than that of vastus lateralis (VL) and vastus medialis (VM) muscles. The highest localized O<inf>2</inf>consumption rate, VO<inf>2</inf>, reflecting the localization in distribution of muscle metabolism, was detected in the RF muscle at the initial stage of exercise. As exercise progressed, VO<inf>2</inf>of the RF muscle decreased whereas that of the VL and VM muscles increased. In contrast, TOS decreased to about the same level for the VL, RF and VM muscles in the latter exercise. Also, VO<inf>2</inf>of all three muscles decreased as exercise progressed. Initial results demonstrated that the SR-NIRS instrument enables measurement of regional differences in muscle oxygenation in the quadriceps muscle during different exercises.

Molecular characterization of a putative protein disulfide isomerase from Babesia caballi

We produced a mAb against the Babesia caballi extracellular merozoite termed mAb 2H2 and used it to screen a cDNA expression library prepared from B. caballi merozoite mRNA for highly expressed proteins. The complete nucleotide sequence of the cloned gene had 1547 nucleotides and contained a 36-nucleotide intron. The 1398 nucleotide open reading frame predicts a 51 kDa protein showing similarity to protein disulfide isomerase (PDI) from other species. The PDI gene had a predicted N-terminal signal sequence of 19 amino acids and a C-terminal tetrapeptide sequence (His-Thr-Glu-Leu; HTEL) for retention in lumen of the endoplasmic reticulum (ER). The recombinant protein expressed in baculovirus showed an apparent mass of 51 kDa, identical to that the native B. caballi protein. Moreover, the ER retention signal site (HTEL) of the recombinant protein retained its function in ER of insect cells. This 51 kDa protein was strongly expressed by extracelluar B. caballi merozoites in indirect immunofluorescence antibody tests, and was not expressed in the early phase of trophozoite development. Interestingly, detailed observation showed that the reaction of anti-P51 antibody and mAb 2H2 against pear-shaped forms was very erratic, some displaying one or two brightly fluorescent patterns.

Multicentre prospective study of perinatal depression in Japan: incidence and correlates of antenatal and postnatal depression

A multicentre study on the epidemiology of perinatal depression was conducted among Japanese women expecting the first baby (N = 290). The incidence rate of the onset of the DSM-III-R Major Depressive Episode during pregnancy (antenatal depression) and within 3 months after delivery (postnatal depression) were 5.6% and 5.0%, respectively. Women with antenatal depression were characterised by young age and negative attitude towards the current pregnancy, whereas women with postnatal depression were characterised by poor accommodation, dissatisfaction with sex of the newborn baby and with the emotional undermining. Antenatal depression was a major risk factor for postnatal depression.

Congenital dermatofibrosarcoma protuberans with fibrosarcomatous and myxoid change

This report describes a case of congenital dermatofibrosarcoma protuberans (DFSP) with fibrosarcomatous (FS) and myxoid areas. Immunohistochemical results showed that tumour cells in ordinary DFSP areas were diffusely positive for CD34, whereas in the FS and myxoid areas, few tumour cells were positive for this antigen. Ki-67 positive tumour cell numbers were greater in the FS (11.8%) and myxoid areas (19.8%) relative to ordinary DFSP areas (2.2%). Reverse transcription polymerase chain reaction and sequence analysis showed the presence of an identical COL1A1-PDGFB fusion transcript in ordinary DFSP (plaque-like area), FS, and myxoid areas of DFSP. These results indicate that the three components of DFSP have a common histogenesis. This study documents the first application of gene analysis involving the myxoid area of DFSP.

Characterization of monoclonal antibodies against Gnathostoma nipponicum

Monoclonal antibodies (mAbs) were produced against the proteins of advanced third-stage larvae (AdL3) of Gnathostoma nipponicum. Six mAbs (Gn2C3, Gn2H3, Gn4C3, Gn4E9, GnSH1, and Gn10B7) were obtained as determined by enzyme-linked immunosorbent assay (ELISA). Gn4E9 and GnSH1 seemed to be genus-specific, as they did not cross-react with Anisakis sp., Dirofilaria immitis, Gongylonema pulchrum, Toxocara canis, Trichinella sp., Trichuris vulpis, Metagonimus sp., or Spirometra erinaceieuropaei by ELISA. Immunohistochemistry showed that Gn2C3, Gn4E9, and Gn5H1 reacted strongly with the central esophagus; Gn2H3 reacted with cuticle,muscle, intestine, and the cervical sac; and Gn4C3 and Gn10B7 reacted with cuticle, muscle, esophagus, intestine, and the cervical sac of AdL3. In Western blotting analysis, Gn2C3, Gn4E9, and Gn5H1 reacted to 60-, 53-, 46-, and 41-kDa proteins; Gn4C3 reacted to the AdL3 protein of G. nipponicum (>42 kDa). Moreover, proteins purified using a mAb Gn4E9 immunoprecipitation method (sizes 60-, 53-, 46-, and 41-kDa) were used as antigens in ELISAs. A significant difference (P < 0.01) was shown between mouse sera infected with G. nipponicum and sera infected with Trichnella sp. or not infected. These results provide a rationale for evaluating esophageal proteins for the development of diagnostic methods for detecting G. nipponicum or Gnathostoma sp. infections.

Analysis of a growth-promoting factor for Babesia caballi cultivation

Serum-free media were examined to culture Babesia caballi. Daigo's T (DT) basal medium supplemented with Daigo's GF21 (GF21) or GIT medium, which already contains GF21, supported the parasite propagation at 37 C in a humidified atmosphere under 5% CO2 in air. Growth of B. caballi was dependent of the suitable concentration (10-20%) of GF21. Therefore, GF21 was suggested as the growth-promoting factor for B. caballi. However, GIT medium did not support the growth of parasites from cryopreserved stabilates, and serum supplementation was essential for the retrieval of parasites.

Metabolic alterations by clofibric acid in the formation of molecular species of phosphatidylcholine in rat liver

The mechanism by which p-chlorophenoxyisobutyric acid (clofibric acid) induces striking changes in the proportion of the molecular species of phosphatidylcholine (PC) in rat liver was studied. Treatment of rats with clofibric acid strikingly increased the content of 1-palmitoyl-2-oleoyl (16:0-18:1) PC, but decreased the contents of 1-palmitoyl-2-docosahexaenoyl (16:0-22:6), 1-stearoyl-2-arachidonoyl (18:0-20:4), and 1-stearoyl-2-linoleoyl (18:0-18:2) PC; the drug did not change the content of 1-palmitoyl-2-arachidonoyl (16:0-20:4) PC. The mechanism underlying these changes has been investigated with regard to the in vivo formation of the molecular species of PC by: (i) de novo synthesis, (ii) reacylation, and (iii) methylation of phosphatidylethanolamine (PE). We found that (i) the incorporation of [3H]glycerol, which was injected intravenously, into 16:0-18:1 diacylglycerol (DG) and 16:0-18:1 PC was increased markedly by clofibric acid feeding without changing the substrate specificity of CDP-choline:DG cholinephosphotransferase, (ii) the in vivo formation of 16:0-18:1 and 16:0-20:4 PC from 1-16:0-[3H]glycerophosphocholine (GPC), which was injected intraportally, was increased markedly by clofibric acid feeding, and (iii) the incorporation of [14C]ethanolamine, which was injected intravenously into 16:0-22:6, 18:0-22:6, and 18:0-20:4 PC, was decreased by clofibric acid feeding; the extent of the decrease in 16:0-20:4 PC was less than that of 18:0-20:4 PC. It was concluded, therefore, that (i) clofibric acid selectively increased the content and proportion of 16:0-18:1 PC by enhancing both the CDP-choline pathway and the remodeling of the pre-existing PC molecule, and (ii) the drug kept the content of 16:0-20:4 PC unchanged by stimulating the remodeling of the pre-existing PC molecule, whereas the formation of other more long chain, polyunsaturated molecular species, such as 16:0-22:6, 18:0-22:6, and 18:0-20:4, was decreased owing to the suppression of PE methylation.

Effects of dehydroepiandrosterone on oleic acid formation in the liver of rats, mice and guinea pigs

The purpose of the present study is to answer the question of whether there is a species difference in the effects of a pharmacological dose of dehydroepiandrosterone (DHEA) on the enzymes that participate in oleic acid (18:1) formation in the liver. Feeding a diet containing 0.5% (w/w) DHEA for 14 days markedly increased the activities of acyl-coenzyme A (CoA) synthetase, palmitoyl-CoA chain elongase and stearoyl-CoA desaturase in the liver of rats and mice. These enzyme activities, however, were not changed by DHEA in guinea pigs. The treatments of rats and mice with DHEA markedly increased proportions of 18:1 in hepatic lipids, especially phosphatidylcholine (selectively at C-2 position), triacylglycerol and cholesterol ester. DHEA caused no significant changes in acyl compositions of hepatic lipids of guinea pigs. The levels of DHEA or dehydroepiandrosterone sulfate (DHEAS) were markedly increased in serum and livers by DHEA administration to rats, mice and guinea pigs. High correlations were observed between hepatic levels of DHEA or DHEAS and stearoyl-CoA desaturase activities in rats. These results indicate that there are species differences in the inducing effects of DHEA or DHEAS on hepatic formation of 18:1 and that guinea pigs lack the machinery to induce the enzymes.

Developmental changes in 5-hydroxytryptamine-induced rhythmic activity in the spinal cord of rat fetuses in vitro

The roles played by glycine- and glutamate-mediated synaptic transmission in the generation of 5-hydroxytryptamine (5-HT)-induced rhythmic activity were examined in isolated spinal cord preparations from fetal rats. Bath application of 5-HT (0.1-30 microM) evoked rhythmic activity in lumbar ventral roots at and after E14.5. Bath application of strychnine (5 microM), a glycine-receptor antagonist, reduced the frequency of the rhythmic activity to 37% of control at E14.5. Although, kynurenate (4 mM), a glutamate-receptor antagonist, had little effect at this stage, it completely abolished the 5-HT-induced rhythmic activity at and after E18.5, when strychnine had little effect on the frequency. These results indicate that, at and shortly after its onset, the rhythmic activity is driven mainly by glycinergic rather than glutamatergic excitatory synaptic inputs, but that the latter become dominant later on.

The first host record of trichinosis in a red fox, Vulpes vulpes japonica, from Aomori Prefecture, northern Honshu, Japan

A case of wildlife trichinosis was found in a red fox (Vulpes vulpes japonica) captured at Rokkasho, Aomori Prefecture on November 27, 1998. Trichinella larvae were obtained from almost all of the muscle tissues except for the masseter. The highest number of larvae per gram of tissue was found in the muscles of the gluteal region and throat. The lowest number was found in the diaphragm and tongue. Trichina cysts within the muscle fibers had groups of fatty cells at the poles, and minimal tissue reaction was observed around the cyst. No calcification was found in the cyst. These morphological findings suggested that the considerable time had elapsed since the invasion. This is the first case of trichinosis in a red fox in Japan.

Detection of cytokeratin 19 and 20 mRNA in peripheral and mesenteric blood from colorectal cancer patients and their prognosis

To detect the presence of cancer cells in peripheral and mesenteric blood and to examine their relationship to prognosis in colorectal cancer patients undergoing curative surgery, we examined cytokeratin 19 and 20 mRNA in peripheral and mesenteric venous blood. Using reverse transcriptase polymerase chain reaction, cytokeratin 19 and 20 mRNA was amplified in peripheral and mesenteric blood samples obtained from 35 colorectal cancer patients who underwent curative surgery. Cytokeratin 19 or 20 mRNA in peripheral or mesenteric blood samples was detected in 18 of 35 cases (51%). There was no significant difference in Dukes' staging between the positive and negative groups. The median follow-up period was 56 months. In the positive group six patients (33%) showed recurrences. One patient (6%) showed recurrence in the negative group. The recurrence rate was significantly higher in the positive group than in the negative group. Five-year disease-free survival was significantly better in the negative group than in the positive group (94% vs. 65%). The detection of cytokeratin 19 or 20 mRNA in peripheral or mesenteric blood is thus associated with the prognosis for colorectal cancer patients undergoing curative surgery. Although the presence of these mRNAs in blood samples is a prognostic marker, the clinical utility of this assay is questionable because of the low recurrence rate in the positive group.

Comparison of the elimination between perfluorinated fatty acids with different carbon chain length in rats

Elimination in urine and feces was compared between four perfluorinated fatty acids (PFCAs) with different carbon chain length. In male rats, perfluoroheptanoic acid (PFHA) was rapidly eliminated in urine with the proportion of 92% of the dose being eliminated within 120 h after an intraperitoneal injection. Perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) was eliminated in urine with the proportions of 55, 2.0 and 0.2% of the dose, respectively. By contrast, four PFCAs were eliminated in feces with the proportion of less than 5% of the dose within 120 h after an injection. In female rats, the proportions of PFOA and PFNA eliminated in urine within 120 h were 80% and 51% of the dose, respectively, which were significantly higher compared with those in male rats. There was the tendency that PFCA with longer carbon chain length is less eliminated in urine in both male and female rats. Fecal elimination of PFCAs was not different between PFCAs in female rats and comparable to those in male rats. The rates of biliary excretion of PFCAs in male rats were slower than those in female rats. Sex-related difference in urinary elimination of PFOA was abolished when male rats had been castrated. On the contrary, treatment with testosterone suppressed the elimination of PFOA in urine in both castrated male rats and female rats. The effect of testosterone was in a time- and dose-dependent manner. These results suggest that PFCAs are distinguished by their carbon chain length by a renal excretion system, which is regulated by testosterone.

Influence of a fat on muscle oxygenation measurement using near-IR spectroscopy: quantitative analysis based on two-layered phantom experiments and Monte Carlo simulation

The influence of a subcutaneous fat layer on measurement of muscle oxygenation using near-IR spectroscopy was quantitatively investigated by two-layered phantom experiments and Monte Carlo simulations, with the aim of developing an algorithm that can correct this influence. The phantom consisted of a fat-like layer, which was a mixture of agar and titanium dioxide powder, and a muscle-like layer, which was suspension of washed bovine blood in Intralipid solution. An LED with 760 and 840 nm elements was used as an optical source, and the backscattered light was detected by photodiodes at source-detector distances of 20, 30 and 40 mm. The relationships between changes in optical density and blood concentrations were obtained at fat-like layer thicknesses of 0.5,10 and 15 mm under fully oxygenated and fully deoxygenated states. It was experimentally found that the change in optical density is significantly decreased and the linearity of measurement characteristics is clearly distorted by the presence of a fat layer. In the simulations, normalized light reflectance and mean optical pathlength in a muscle layer were calculated. The simulation results of the light reflectance agreed well with the experimental results. When the absorption in a muscle layer was relatively high, the mean optical pathlength in the muscle layer, or the measurement sensitivity, was not so dependent on the absorption. Therefore, the modified Beer-Lambert law can still be applied to estimate changes in muscle absorption from changes in optical density, even when a fat layer is involved. The results of simulation also suggested that the influence of a fat layer can be eliminated by correcting the measurement sensitivity using the fat layer thickness.

Three-dimensional solution structure of oryzacystatin-I, a cysteine proteinase inhibitor of the rice, Oryza sativa L. japonica

The three-dimensional structure of oryzacystatin-I, a cysteine proteinase inhibitor of the rice, Oryza sativa L. japonica, has been determined in solution at pH 6.8 and 25 degrees C by (1)H and (15)N NMR spectroscopy. The main body (Glu13-Asp97) of oryzacystatin-I is well-defined and consists of an alpha-helix and a five-stranded antiparallel beta-sheet, while the N- and C-terminal regions (Ser2-Val12 and Ala98-Ala102) are less defined. The helix-sheet architechture of oryzacystatin-I is stabilized by a hydrophobic cluster formed between the alpha-helix and the beta-sheet and is considerably similar to that of monellin, a sweet-tasting protein from an African berry, as well as those of the animal cystatins studied, e.g., chicken egg white cystatin and human stefins A and B (also referred to as human cystatins A and B). Detailed structural comparison indicates that oryzacystatin-I is more similar to chicken cystatin, which belongs to the type-2 animal cystatins, than to human stefins A and B, which belong to the type-1 animal cystatins, despite different loop length.

Formation of the central pattern generator for locomotion in the rat and mouse

It is well known that in the neonatal rat spinal cord preparation, alternating rhythmic bursts in the left and right ventral roots in a given lumbar segment can be induced by bath-application of N-methyl-D-aspartate or 5-hydroxytryptamine. Alternation between L2 and L5 ventral roots on the same side, representing the activity of flexor and extensor muscles, respectively, can be observed as well. In the prenatal period in the rat, alternation between the left and right ventral roots is established between embryonic day (E) 16.5 and E18.5. The alternation between the L2 and L5 ventral roots emerges at E20.5. Recent findings show that locomotor-like rhythmic activity with similar characteristics can be induced in the neonatal mouse preparation. In the lumbar spinal cord in the neonatal mouse, it is likely that the rhythm-generating network is distributed throughout the lumbar region with a rostro-caudal gradient, a situation similar to that in the neonatal and fetal rat spinal cord. With this review we hope to highlight the dramatic changes that neuronal networks generating locomotor-like activity undergo during the prenatal development of the rat. Moreover, the distribution of the neuronal network generating the locomotor rhythm in the neonatal rat and mouse spinal cord is compared.

Formation of the central pattern generator for locomotion in the rat and mouse

It is well known that in the neonatal rat spinal cord preparation, alternating rhythmic bursts in the left and right ventral roots in a given lumbar segment can be induced by bath-application of N-methyl-D-aspartate or 5-hydroxytryptamine. Alternation between L2 and L5 ventral roots on the same side, representing the activity of flexor and extensor muscles, respectively, can be observed as well. In the prenatal period in the rat, alternation between the left and right ventral roots is established between embryonic day (E) 16.5 and E18.5. The alternation between the L2 and L5 ventral roots emerges at E20.5. Recent findings show that locomotor-like rhythmic activity with similar characteristics can be induced in the neonatal mouse preparation. In the lumbar spinal cord in the neonatal mouse, it is likely that the rhythm-generating network is distributed throughout the lumbar region with a rostro-caudal gradient, a situation similar to that in the neonatal and fetal rat spinal cord. With this review we hope to highlight the dramatic changes that neuronal networks generating locomotor-like activity undergo during the prenatal development of the rat. Moreover, the distribution of the neuronal network generating the locomotor rhythm in the neonatal rat and mouse spinal cord is compared.

Oxidative stress abolishes leptomycin B-sensitive nuclear export of transcription repressor Bach2 that counteracts activation of Maf recognition element

The mammalian transcription activator Nrf2 plays critical roles in executing oxidative stress response by binding to the regulatory DNA sequence Maf recognition element. Bach2 is an Nrf2-related transcription repressor and a tissue-specific partner of the Maf oncoprotein family. We show here how Bach2 is regulated by an oxidative stress-sensitive conditional nuclear export. In cultured cells, Bach2 was localized in cytoplasm through its C-terminal evolutionarily conserved cytoplasmic localization signal (CLS). The CLS directed leptomycin B-sensitive nuclear export of reporter proteins, suggesting its dependence on the nuclear exporter Crm1/exportin 1. However, the CLS sequence does not bear a resemblance to the leucine-rich class of nuclear export signal, and mutagenesis analysis indicated that a stretch of nonhydrophobic amino acids is essential for its activity. Oxidative stressors aborted the CLS activity and induced nuclear accumulation of Bach2. Whereas oxidative stress is known to activate MARE-dependent transcription, overexpression of Bach2 in cultured cells silenced the inducibility of MARE. The results suggest that Bach2 mediates nucleocytoplasmic communication to couple oxidative stress and transcription repression in mammalian cells.

4-Sulfenyl-2-carbamoyl-4-isoxazolin-3-ones: biological isostere to 4-chloro-2-carbamoyl-4-isoxazolin-3-ones

4-Sulfenyl-2-carbamoyl-4-isoxazolin-3-ones (4) were designed on the basis of biological isosterism and prepared in four steps. Some of these compounds showed sufficient pre-emergent herbicidal activities against various kinds of weeds. Among the synthesized compounds, 2-(N-(4-chlorophenyl)-N-isopropylcarbamoyl)-4-ethylthio-5-methyl-4 -isoxazolin-3-one (4cd) exhibited the most promising activity.

5-Hydroxytryptamine-induced locomotor rhythm in the neonatal mouse spinal cord in vitro

We examined the 5-hydroxytryptamine (5-HT)-induced locomotor rhythm in isolated spinal cord preparations taken from neonatal mice on postnatal day (P) 0-3. Motor activity was recorded from L2 and L5 ventral roots. Bath application of 5-HT (15-100 microM) evoked rhythmic bursts that alternated between the two sides, and the bursts in the L2 ventral root alternated with those in the ipsilateral L5 ventral root. After transection of the mid-lumbar cord, the locomotor rhythm in L2 persisted, while that in the L5 ventral root was abolished. This suggests that the upper lumbar region has a greater ability to generate a locomotor rhythm than the lower lumbar spinal cord. Kynurenate, a broad-spectrum glutamate receptor antagonist, blocked the 5-HT-induced locomotor rhythm indicating that ionotropic glutamate receptors are required for the rhythm to be generated.

A nuclear export signal in the N-terminal regulatory domain of IkappaBalpha controls cytoplasmic localization of inactive NF-kappaB/IkappaBalpha complexes

Appropriate subcellular localization is crucial for regulation of NF-kappaB function. Herein, we show that latent NF-kappaB complexes can enter and exit the nucleus in preinduction states. The nuclear export inhibitor leptomycin B (LMB) sequestered NF-kappaB/IkappaBalpha complexes in the nucleus. Using deletion and site-directed mutagenesis, we identified a previously uncharacterized nuclear export sequence in residues 45-54 of IkappaBalpha that was required for cytoplasmic localization of inactive complexes. This nuclear export sequence also caused nuclear exclusion of heterologous proteins in a LMB-sensitive manner. Importantly, a LMB-insensitive CRM1 mutant (Crm1-K1) abolished LMB-induced nuclear accumulation of the inactive complexes. Moreover, a cell-permeable p50 NF-kappaB nuclear localization signal peptide also blocked these LMB effects. These results suggest that NF-kappaB/IkappaBalpha complexes shuttle between the cytoplasm and nucleus by a nuclear localization signal-dependent nuclear import and a CRM1-dependent nuclear export. The LMB-induced nuclear complexes could not bind DNA and were inaccessible to signaling events, because LMB inhibited NF-kappaB activation without affecting the subcellular localization of upstream kinases IKKbeta and NIK. Our findings indicate that the dominant nuclear export over nuclear import contributes to the largely cytoplasmic localization of the inactive complexes to achieve efficient NF-kappaB activation by extracellular signals.

Developmentally regulated activity of CRM1/XPO1 during early Xenopus embryogenesis

In this work, we have investigated the role of CRM1/XPO1, a protein involved in specific export of proteins and RNA from the nucleus, in early Xenopus embryogenesis. The cloning of the Xenopus laevis CRM1, XCRM1, revealed remarkable conservation of the protein during evolution (96.7% amino acid identity between Xenopus and human). The protein and mRNA are maternally expressed and are present during early embryogenesis. However, our data show that the activity of the protein is developmentally regulated. Embryonic development is insensitive to leptomycin B, a specific inhibitor of CRM1, until the neurula stage. Moreover, the nuclear localization of CRM1 changes concomitantly with the appearance of the leptomycin B sensitivity. These data suggest that CRM1, present initially in an inactive form, becomes functional before the initiation of the neurula stage during gastrula-neurula transition, a period known to correspond to a critical transition in the pattern of gene expression. Finally, we confirmed the gastrula-neurula transition-dependent activation of CRM1 by pull-down experiments as well as by the study of the intracellular localization of a green fluorescent protein tagged with a nuclear export signal motif during early development. This work showed that the regulated activity of CRM1 controls specific transitions during normal development and thus might be a key regulator of early embryogenesis.

Induction by perfluorinated fatty acids with different carbon chain length of peroxisomal beta-oxidation in the liver of rats

The potency of the induction of peroxisomal beta-oxidation was compared between perfluorinated fatty acids (PFCAs) with different carbon chain lengths in the liver of male and female rats. In male rats, perfluoroheptanoic acid (PFHA) has little effect, although perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA) and perfluorodecanoic acid (PFDA) potentially induced the activity. By contrast, PFHA and PFOA did not induce the activity of peroxisomal beta-oxidation in the liver of female rats while PFNA and PFDA effectively induced the activity. The induction of the activity by these PFCAs was in a dose-dependent manner, and there is a highly significant correlation between the induction and hepatic concentrations of PFCAs in the liver regardless of their carbon chain lengths. These results strongly suggest that the difference in their chemical structure is not the cause of the difference in the potency of the induction. Hepatic concentrations of PFOA and PFNA was markedly higher in male compared with female rats. Castration of male rats reduced the concentration of PFNA in the liver and treatment with testosterone entirely restored the reduction. In contrast to the results obtained from the in vivo experiments, the activity of peroxisomal beta-oxidation was induced by PFDA and PFOA to the same extent in cultured hepatocytes prepared from both male and female rats. These results, taken together, indicate that difference in accumulation between PFCAs in the liver was responsible for the different potency of the induction of peroxisomal beta-oxidation between PFCAs with different carbon chain lengths and between sexes.

Increase in hepatic content of oleic acid induced by dehydroepiandrosterone in the rat

The effects of dehydroepiandrosterone (DHEA) on the acyl composition of lipids in rat liver were studied. The content of oleic acid (18:1) in hepatic lipids was increased markedly by feeding rats a diet containing 0.5% (w/w) DHEA for 14 days. Treatment of rats with DHEA caused an increase in the activity of the terminal desaturase of the stearoyl-CoA desaturation system, without changing either the activity of NADH-cytochrome b5 reductase or the microsomal content of cytochrome b5. Among the changes observed in hepatic lipids, the increase in 18:1 content in phosphatidylcholine (PtdCho) was the most prominent; an approximately 2.5-fold increase in the proportion of 18:1 was induced at position 2, but not at position 1, by DHEA. This selective elevation of 18:1 at position 2 of PtdCho seems to be produced by the concerted actions of the induced 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase and the induced stearoyl-CoA desaturase. The content of 18:1 in serum lipids was unchanged by DHEA treatment, suggesting that secretion of lipids containing 18:1 into the circulation was not affected by DHEA. These results suggest that the elevation of hepatic content of 18:1 caused by DHEA treatment is mainly due to the induction of stearoyl-CoA desaturase.

Leptomycin B inactivates CRM1/exportin 1 by covalent modification at a cysteine residue in the central conserved region

The cellular target of leptomycin B (LMB), a nuclear export inhibitor, has been identified as CRM1 (exportin 1), an evolutionarily conserved receptor for the nuclear export signal of proteins. However, the mechanism by which LMB inhibits CRM1 still remains unclear. CRM1 in a Schizosaccharomyces pombe mutant showing extremely high resistance to LMB had a single amino acid replacement at Cys-529 with Ser. The mutant gene, named crm1-K1, conferred LMB resistance on wild-type S. pombe, and Crm1-K1 no longer bound biotinylated LMB. (1)H NMR analysis showed that LMB bound N-acetyl-L-cysteine methyl ester through a Michael-type addition, consistent with the idea that LMB binds covalently via its alpha, beta-unsaturated delta-lactone to the sulfhydryl group of Cys-529. When HeLa cells were cultured with biotinylated LMB, the only cellular protein bound covalently was CRM1. Inhibition by N-ethylmaleimide (NEM), an alkylating agent, of CRM1-mediated nuclear export probably was caused by covalent binding of the electrophilic structure in NEM to the sulfhydryl group of Cys-529, because the crm1-K1 mutant showed the normal rate for the export of Rev nuclear export signal-bearing proteins in the presence of not only LMB but also NEM. These results show that the single cysteine residue determines LMB sensitivity and is selectively alkylated by LMB, leading to CRM1 inactivation.

cDNA cloning of a stage-specific gene expressed during HCG-induced spermatogenesis in the Japanese eel

A single injection of human chorionic gonadotropin (HCG) can induce complete spermatogenesis in immature Japanese eel (Anguilla japonica) testes consisting of only premitotic spermatogonia. Proliferation of spermatogonia, meiosis and spermiogenesis begin on 3, 12 and 18 days after HCG injection, respectively. To isolate the genes responsible for regulating the initiation of meiosis, differential mRNA display using poly (A)+ RNA extracted from testes of eels at different times after HCG treatment was carried out. Five cDNA clones in which expression was initiated before the onset of meiosis were obtained. Northern blot analysis showed that one clone, which encoded activin betaB subunit, was expressed in the initial phase of spermatogenesis (1-6 days after HCG treatment), in agreement with the previous suggestion that activin B induces the initiation of spermatogenesis in the Japanese eel. The remaining four were expressed in the testes during the following time frames: 3-18 days (two clones), 6-18 days (one clone) and 9-18 days (one clone) after HCG treatment. One of the two clones expressed on day 3 exhibited strong expression on days 12 and 15, just at the initiation period of meiosis. This clone was selected as a candidate gene responsible for initiating meiosis, and its full-length cDNA isolated. The cDNA contained an open reading frame of 1571 nucleotides encoding a protein of 260 amino acid residues, which showed high homology with the proliferating cell nuclear antigen (PCNA) of human, mouse and Xenopus. Northern blot analysis using eel PCNA cDNA showed that a 1.6 kb transcript first appeared on day 3 and became abundant, reaching maximum levels on days 12-15. In situ hybridization analysis revealed that PCNA mRNA was expressed strongly in late type B spermatogonia before the sixth mitotic division. It has already been shown that spermatogonia have a regulatory point to enter meiosis between the fifth and sixth mitotic division. The coincidence of PCNA expression and this regulatory point suggests an involvement of PCNA in the progression of mitotic germ cells into meiosis during HCG-induced spermatogenesis in the eel.

A novel nuclear export signal sensitive to oxidative stress in the fission yeast transcription factor Pap1

Pap1, a fission yeast AP-1-like transcription factor, is negatively regulated by CRM1/exportin 1, the nuclear export factor. Pap1 was localized normally in the cytoplasm but was accumulated in the nucleus when Crm1 was inactivated by a temperature-sensitive mutation or by treatment with leptomycin B, a specific export inhibitor. Deletion of the C-terminal cysteine-rich domain (CRD) resulted in nuclear accumulation of Pap1, while a glutathione S-transferase-green fluorescent protein-CRD fusion protein was localized in the cytoplasm in a Crm1-dependent manner. Deletion and mutational analyses identified several important amino acids in a 19-amino acid region in the CRD as a nuclear export signal (NES). Strikingly, a cysteine residue (Cys-532), in addition to two leucines and an isoleucine, was important for the NES function and the presence of at least one of the two cysteine residues was essential. Unlike classical NESs such as the human immunodeficiency virus Rev NES, the Pap1 NES lost the function upon treatment with oxidants such as diethyl maleate. The oxidative stress response is conserved through evolution, as green fluorescent protein-fused proteins bearing the Pap1 NES expressed in mammalian cells responded to diethyl maleate. These results show that the hydrophobic amino acid-rich region containing two important cysteines in Pap1 serves as a novel NES, which is sensitive to oxidative stress.

Rostrocaudal progression in the development of periodic spontaneous activity in fetal rat spinal motor circuits in vitro

Rostrocaudal progression in the development of periodic spontaneous activity in fetal rat spinal motor circuits in vitro. Developmental changes in the periodic spontaneous bursts in cervical and lumbar ventral roots (VRs) were investigated using isolated spinal cord preparations obtained from rat fetuses at embryonic days (E) 13.5-18. 5. Spontaneous bursts were observed in the cervical VR at E13.5-17.5, and in the lumbar VR at E14.5-17.5. Bursts occurrence in the cervical and lumbar VRs was correlated in a 1:1 fashion at E14.5-16. 5. The bursts in the cervical VR preceded those in the lumbar VR at E14.5, but the latter came to precede the former by E16.5. The interval between spontaneous bursts in the lumbar VR was greatly prolonged after spinal cord transection at the midthoracic level at E14.5, whereas that in the cervical VR became significantly longer at E14.5-16.5. These results suggest that the dominant neuronal circuit initiating the spontaneous bursts shifts from cervical to lumbar region during this period. Bath application of a glutamate receptor antagonist, kynurenate (4 mM), had little effect on the spontaneous bursts in either cervical or lumbar VRs at E14.5-15.5. At E16.5, kynurenate abolished the spontaneous bursts in the cervical VR. Concomitant application of kynurenate and strychnine (5 microM), a glycine receptor antagonist, abolished all spontaneous bursts, suggesting that the major transmitter mediating the spontaneous bursts changes from glycine to glutamate in the cervical region by E16.5, but not in the lumbar region during this period.

Phosphorylation control of cardiac acetyl-CoA carboxylase by cAMP-dependent protein kinase and 5'-AMP activated protein kinase

Acetyl-CoA carboxylase (ACC) is regarded in liver and adipose tissue to be the rate-limiting enzyme for fatty acid biosynthesis; however, in heart tissue it functions as a regulator of fatty acid oxidation. Because the control of fatty acid oxidation is important to the functioning myocardium, the regulation of ACC is a key issue. Two cardiac isoforms of ACC exist, with molecular masses of 265 kDa and 280 kDa (ACC265 and ACC280). In this study, these proteins were purified from rat heart and used in subsequent phosphorylation and immunoprecipitation experiments. Our results demonstrate that 5' AMP-activated protein kinase (AMPK) is able to phosphorylate both ACC265 and ACC280, resulting in an almost complete loss of ACC activity. Although cAMP-dependent protein kinase phosphorylated only ACC280, a dramatic loss of ACC activity was still observed, suggesting that ACC280 contributes most, if not all, of the total heart ACC activity. ACC280 and ACC265 copurified under all experimental conditions, and purification of heart ACC also resulted in the specific copurification of the alpha2 isoform of the catalytic subunit of AMPK. Although both catalytic subunits of AMPK were expressed in crude heart homogenates, our results suggest that alpha2, and not alpha1, is the dominant isoform of AMPK catalytic subunit regulating ACC in the heart. Immunoprecipitation studies demonstrated that specific antibodies for both ACC265 and ACC280 were able to coimmunoprecipitate the alternate isoform along with the alpha2 isoform of AMPK. Taken together, the immunoprecipitation and the purification studies suggest that the two isoforms of ACC in the heart exist in a heterodimeric structure, and that this structure is tightly associated with the alpha2 subunit of AMPK.

Effects of tiadenol and di-(2-ethylhexyl)phthalate on the metabolism of phosphatidylcholine and phosphatidylethanolamine in the liver of rats: comparison with clofibric acid

Metabolic changes induced by 2,2'-(decamethylenedithio)diethanol (tiadenol) and di-(2-ethylhexyl)phthalate (DEHP) in the biosynthesis of phosphatidylcholine (PtdCho) and phosphatidylethanolamine (PtdEtn) in rat liver were compared with changes induced by p-chlorophenoxyisobutyric acid (clofibric acid). Treatment of rats with either tiadenol or DEHP increased the hepatic contents of PtdCho and PtdEtn, as was observed with clofibric acid treatment. The administration of tiadenol, DEHP, or clofibric acid slightly, but significantly, increased, in common, the activity of CTP:phosphocholine cytidylyltransferase, a key enzyme for the synthesis de novo of PtdCho, and suppressed the activity of PtdEtn N-methyltransferase. With regard to the enzymes involved in the synthesis of PtdEtn, the three peroxisome proliferators enhanced the activity of phosphatidylserine (PtdSer) decarboxylase and markedly decreased the activity of CTP:phosphoethanolamine cytidylyltransferase. Treatment of rats with the three compounds markedly increased, in common, the content and the proportion of the molecular species of PtdCho containing oleic acid (18:1), but considerably decreased the proportion of the molecular species of PtdCho containing linoleic acid (18:2) in the liver, resulting in a striking decrease in the concentration of the molecular species of PtdCho containing 18:2 in the serum. The present study suggests that the administration of peroxisome proliferators to rats increases the contents of hepatic PtdCho and PtdEtn for hepatomegaly and proliferation of organelles by the same mechanism, irrespective of their chemical structures.

Alterations by perfluorooctanoic acid of glycerolipid metabolism in rat liver

The effects of perfluorooctanoic acid (PFOA) feeding on hepatic levels of glycerolipids and the underlying mechanism were investigated. Feeding of rats with 0.01% of PFOA in the diet for 1 week caused an increase in the contents of phosphatidylcholine (PtdCho), phosphatidylethanolamine (PtdEtn), phosphatidylinositol (PtdIns), phosphatidylserine (PtdSer) and triglyceride (TG), which were 2.2, 2.4, 2.4, 1.6 and 5.2 times over control, respectively, on the basis of whole liver. The activities of glycerol-3-phosphate acyltransferase, diacylglycerol kinase and PtdSer decarboxylase were significantly increased upon PFOA feeding, whereas the activities of CTP:phosphoethanolamine cytidylyltransferase and PtdEtn N-methyltransferase were decreased. On the other hand, the activity of CTP:phosphocholine cytidylyltransferase was not increased by PFOA. Upon PFOA feeding, hepatic level of 16:0-18:1 PtdCho was markedly increased and, by contrast, the levels of molecular species of PtdCho which contain 18:2 were decreased, resulting in the reduced concentration of molecular species of serum PtdCho containing 18:2. The increase in the level of hepatic 16:0-18:1 PtdCho seemed to be due to 3-fold increase in the activities of both delta9 desaturase and 1-acylglycerophosphocholine (1-acyl-GPC) acyltransferase. The mechanism by which PFOA causes the accumulation of glycerolipids in liver was discussed.

Determination of perfluorinated carboxylic acids in biological samples by high-performance liquid chromatography

This paper describes a method for the quantitative determination of perfluorinated carboxylic acids (PFCAs), perfluorohexanoic acid (C6-PFCA), perfluoroheptanoic acid (C7-PFCA), perfluorooctanoic acid (C8-PFCA), perfluorononanoic acid (C9-PFCA) and perfluorodecanoic acid (C10-PFCA), in biological samples. PFCA in liver homogenates was extracted as an ion pair with tetrabutylammonium (TBA) ion into organic solvent, then the PFCA was derivatized with 3-bromoacetyl-7-methoxycoumarin (BrAMC) and quantified by HPLC with fluorescence detection. This method is applicable for the studies on tissue accumulation and elimination of PFCAs in animals after the administration.

The pattern of antiganglioside antibody reactivities producing myelinated nerve conduction block in vitro

We studied the pattern of human antiganglioside antibody reactivities causing an acute conduction block in rat myelinated nerve fibers, using an in vitro preparation of the sciatic-tibial nerve. With the aid of complements, IgM antibodies reacting with the terminal disaccharide of galactose (beta1-3)N-acetylgalactosamine produced the block. These findings may help us to understand the mechanism in which the conduction block occurs in neuropathies associated with antiganglioside antibodies.