Production of long-chain polyunsaturated fatty acids by monoxenic growth of labyrinthulids on oil-dispersed agar medium

A novel method is proposed for the production of long-chain polyunsaturated fatty acids (LCPUFA) by labyrinthulids. The method comprises a monoxenic culture with Psychlobacter phenylpyruvicus, using agar medium in which oil was dispersed. Soybean oil (SBO) was selected as the optimum material for an oil-dispersed agar medium. The labyrinthulids showed three-dimensional growth and an anastomosing ectoplasmic network in the SBO-dispersed agar medium. The oil plate changed from an opaque culture to a more transparent culture, due to growth of the labyrinthulids. The optimum culture conditions were 25-30 degrees C, an initial pH of 6-10 and artificial seawater with a salt concentration of 50-100%. These conditions are close to those where these strains were isolated. The maximum LCPUFA production (0.59 g/l) and dry cell weight (4.93 g/l) was obtained using strain S3-2 (isolated from Ishigaki Island) with 1.5% SBO at 14 days. This value was about 30 times more than that using glucose instead of SBO. The method proposed is promising in terms of the production of LCPUFA from reproducible oils.

Regenerative repair of the mandible using a collagen sponge containing TGF-beta1

INTRODUCTION

Alveolar bone resorption and atrophy of the mandible are a major challenge for regeneration medicine. In the present investigation, a collagen sponge that contained TGF-beta1 was placed at a mandibular defect and the osteogenic effects of collagen-TGF-beta1, complex were evaluated.

MATERIAL AND METHODS

The Pm2, Pm3, and Pm4 teeth on both sides of the mandibles of 12 adult beagle dogs (9.0-12.0 kg) were extracted. After the extraction-site wounds healed, a bone defect (10.0 x 15.0 mm-wide, 10.0 mm-deep or 10.0 x 10.0 mm-wide, 10.0 mm-deep) was created on the mandible. A collagen sponge (10.0 x 10.0 x 10.0 mm) that contained TGF-beta1 (1.0 microg, 5.0 microg, or 10.0 microg, in physiological saline) was placed at the bottom of the defect and the overlying mucous membrane was sutured with 4-0 prolene. As a control, a collagen sponge that contained physiological saline only was placed in a defect on the opposite side. Two weeks after the surgery the wounds above the bone defects on both the control and TGF-beta1-treated sides had healed completely.

RESULTS

At four, six, or eight weeks post-operatively animals were killed. Soft X-ray and bone-salt measurement analyses confirmed clearly that there was greater calcified bone formation in the defects into which TGF-beta1 had been incorporated than with the control defects. The implanted collagen sponges were fully resorbed and the bone tissue had regenerated from the bottom of the defects on the TGF-beta1, side by four weeks. On the control side, no such regeneration was observed.

CONCLUSIONS

These results indicate that TGF-beta1, released slowly from a collagen sponge was effective in promoting bone remodeling when applied to mandibular defects in adult dogs.

Exposure to 2.45 GHz electromagnetic fields induces hsp70 at a high SAR of more than 20 W/kg but not at 5W/kg in human glioma MO54 cells

PURPOSE

To determine potential hazards from exposure to a high-frequency electromagnetic field (HFEMF) at 2.45 GHz by studies of the expression of heat-shock protein 70 (hsp70) in MO54 cells.

METHOD

MO54 cells were exposed to a HFEMF at average specific absorption rates (SAR) of 5, 20, 50 and 100 W/kg, using input powers of 0.8, 3.2, 7.8 and 13 W, at a temperature of up to 39 degrees C. An annular culture dish provided three levels of exposure for a given input power, designated inner, middle and outer rings. Two control groups were used: the first was subjected to sham exposure and the second was a temperature control, used to determine the effect of high temperature using incubation in a conventional incubator at 39 degrees C. Cell survival was determined in intervals up to 24 h. Protein was extracted from MO54 cells in both groups after 2, 4, 8 and 16 h exposure times. Changes in the hsp70 protein levels were analysed by Western blots.

RESULTS

Little or no cell death was observed in the sham-exposed cells, nor for incubation at 39 degrees C for up to 16 h. Cell survival decreased to about 30% after exposure to HFEMF for 24 h at an average SAR of 100 W/kg. A slight increase in hsp70 was observed in cells in both the inner and outer rings of the plate after exposure at SAR levels of 25 and 78 W/kg, respectively, for 2 h. With increasing exposure time, hsp70 expression increased except for an SAR of 5 W/kg. In the raised temperature control at 39 degrees C, hsp70 expression also increased as the incubation time increased. However, the expression level of hsp70 for the HFEMF exposure was greater than that for the raised temperature control.

CONCLUSION

HFEMF can produce an increased level of hsp70 expression in MO54 cells at SAR levels above 20 W/kg, even when the effect of raised temperature is taken into account.

Neuronal ectopic expression of tyrosine hydroxylase in the mouse striatum by combined administration of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine and 3-nitropropionic acid

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) is a dopaminergic neurotoxin which inhibits mitochondrial complex I. 3-Nitropropionic acid (3-NPA) inhibits mitochondrial complex II and produces specific striatal lesions. In order to produce a combined striatal neuronal and dopaminergic afferent lesion, we administered both toxins simultaneously to the mouse. The combination brought about a lesion in the striatum that was not simply additive of the two combined toxins. Intriguingly, a group of striatal neurons became immunoreactive to tyrosine hydroxylase after day 1. Some of them were clearly visible up to the dendritic details. Immuno-electron microscopy indicated that the tyrosine hydroxylase-positive striatal neurons contained densely immunoreactive polyribosomes. Reverse transcriptase-polymerase chain reaction analysis indicated the up-regulation of tyrosine hydroxylase mRNA in the treated striatum. These neurons were also immunoreactive to aromatic L-amino acid decarboxylase.We conclude that the combined administration of MPTP and 3-NPA caused a more profound damage to the nigro-striatal dopaminergic system, and thus some striatal neurons capable of up-regulating tyrosine hydroxylase were induced to produce dopamine, probably to compensate for the dopamine depletion.

Bacterial distribution and phylogenetic diversity in the Changjiang estuary before the construction of the Three Gorges Dam

The bacterial community structure in the Changjiang estuary was studied for comparison with future changes, related to the construction of the Three Gorges Dam. Population densities of bacteria in the surface water at station C1 estimated by CFU on marine agar plates and by DAPI direct count, were 2.8 x 10(4) ml(-1) and 4.2 x 10(5) ml(-1), respectively. Physicochemical properties of water, such as temperature and salinity, suggested that station C1 was affected by freshwater from the Changjiang River. Cluster analysis of the PCR-RFLP patterns obtained from 9 samples showed that the bacterial community structure at station C1 was different from the structure at the other stations. Bacterial diversity in the surface water at station C1 was studied based on the genotypes of the 250 clones of 16S rRNA, and on the phenotypes generated on Biolog GN plates for 70 isolates. Sequences of bacteria from two common marine groups, alpha- and gamma-Proteobacteria, were frequently observed. Some other divisions, including the beta-Proteobacteria, C/F/B group, low G+C gram positive, high G+C gram positive, chloroplasts, and relatives of Verrucomicrobia were also observed. The putative dominant species based on both genotype and phenotype analyses were close relatives of Alteromonas macleodii or Roseobacter spp. These results reflected the nutrient-rich environment at station C1.

Mexiletine inhibits pharmacological actions of salbutamol through blockade of beta2-adrenoceptors in bovine tracheal smooth muscle

We examined the effects of mexiletine, a class Ib antiarrhythmic drug, on the changes in tension and adenosine 3',5'-cyclic monophosphate (cAMP) content induced by salbutamol and forskolin in bovine tracheal smooth muscle. Salbutamol (0.0001-1 microM) produced concentration-dependent relaxation in bovine tracheal smooth muscle contracted with methacholine (0.3 microM). Mexiletine (5-500 microM) caused the rightward shifts of concentration-response curves for the relaxant responses to salbutamol in a concentration-dependent manner. Mexiletine (5, 50 or 500 microM) did not change basal cAMP levels, whereas it concentration-dependently attenuated the salbutamol (0.1 microM)-induced cAMP accumulation. On the other hand, mexiletine (500 microM) did not change the concentration-response curves for the relaxant responses to forskolin (0.001-10 microM). Mexiletine slightly but significantly (P<0.05) increased forskolin (1 microM)-induced cAMP accumulation. In radioligand binding experiments, mexiletine concentration-dependently displaced the specific binding of [125I]cyanopindolol to beta-adrenoceptors on bovine tracheal smooth muscle membranes. By contrast, lidocaine, another class Ib antiarrhythmic drug, did not change the binding of [125I]cyanopindolol. These results demonstrate that mexiletine prevents the binding of beta2-adrenoceptor agonists to their receptors and thereby suppresses manifestation of subsequent pharmacological responses.

[A case with diffuse vasospasm after perimesencephalic nonaneurysmal subarachnoid hemorrhage]

Perimesencephalic nonaneurysmal subarachnoid hemorrhage(PNSH), defined as bleeding in the cisterns around the midbrain with a negative four-vessel angiographic study, is uniformly associated with an excellent outcome without associated rebleeding or symptomatic vasospasm. Angiographic vasospasm is uncommon in patients with this disease, and if vasospasm is present, severe and diffuse angiographical vasospasm is rare. We report a case with PNSH who developed severe and diffuse angiographic vasospasm. The patient was a 52-year-old woman who suffered an acute severe headache. We diagnosed PNSH from CT and angiographical findings, and treated her conservatively. Serial angiography, that was performed on the fourteenth day after hemorrhage, showed diffuse and severe angiographic vasospasm affecting both the anterior and the posterior circulation. She was treated with normovolemia, and remained no neurological symptom. Follow-up MR angiography showed improvement of the angiographic vasospasm. When the presence of diffuse and severe vasospasm is detected, a diagnosis of PNSH should not be excluded.

Protein kinase Calpha plays a critical role in mannosylerythritol lipid-induced differentiation of melanoma B16 cells

Mannosylerythritol lipid (MEL), a novel extracellular glycolipid from yeast, was found to inhibit the proliferation of mouse melanoma B16 cells in a dose-dependent manner and to induce the apoptosis of B16 cells at concentrations higher than 10 microm (Zhao, X., Wakamatsu, Y., Shibahara, M., Nomura, N., Geltinger, C., Nakahara, T., Murata, T., and Yokoyama, K. K. (1999) Cancer Res. 59, 482-486). We show here that exposure of B16 cells to MEL (5 microm) for 2 days resulted in an increase of the levels of differentiation-associated markers of melanoma cells such as melanogenesis and tyrosinase activity, which were accompanied by morphological changes. The MEL-induced differentiation of B16 cells at this concentration was closely associated with arrest of the cell cycle at G(1) phase, but no significant population of apoptotic cells was identified. Expression of protein kinase Calpha (PKCalpha) was enhanced after exposure of B16 cells to MEL for 48 h. Antisense oligodeoxynucleotides against the mouse gene for PKCalpha prevented MEL-induced melanogenesis in B16 cells. Conversely, the effects of the expression of a constitutively active form of PKCalpha mimicked the effects of MEL on B16 cells. These data suggest that MEL, a yeast-derived glycolipid, triggers the differentiation of B16 melanoma cells through a signaling pathway that involves PKCalpha.

[Tracheal intubation without muscle relaxants using propofol and varying doses of fentanyl]

This study was designed to evaluate airway and intubating conditions without muscle relaxants after administration of fentanyl and propofol in 55 patients aged 20-60 years for elective surgery. Patients were randomly assigned to one of four groups to receive fentanyl 0, 2, 3, or 4 micrograms.kg-1, respectively. Three minutes after the administration of fentanyl, propofol (2 mg.kg-1) was given for induction of anesthesia. After the loss of consciousness, laryngoscopy and tracheal intubation, supplemented with topical anesthesia of lidocaine (2 mg.kg-1), were attempted. In control group, without administration of fentanyl, all patients were judged to provide poor intubating conditions. Increasing doses of fentanyl reduced the incidences of movement and persistent coughing on laryngoscopy and intubation in a dose-related manner. However, visualization of the vocal cord was significantly. (P < 0.05) more likely to be impossible in patients in 4 micrograms.kg-1 fentanyl group (40%) compared with patients in 2 micrograms.kg-1 fentanyl group (7%). There were no significant differences among groups receiving fentanyl with respect to vocal cord position. The vocal cords were closed in 26% of patients receiving fentanyl and propofol for intubation. Tracheal intubation without muscle relaxants is not recommended because of the potential unacceptable intubating conditions.

Succession of microbial communities during a biostimulation process as evaluated by DGGE and clone library analyses

AIMS

The objective of this study was to investigate the changes in the indigenous bacterial community structure for assessing the impact of biostimulation on spilled oil.

METHODS AND RESULTS

Changes in the bacterial community structure were monitored by denaturing gradient gel electrophoresis (DGGE) and clone library methods based on 16S rRNA gene (rDNA) sequences. The results of DGGE, coupled with the use of the Shannon index and principal component analysis (PCA) and clone library analyses, were consistent. In the treated (fertilized) area, one operational taxonomic unit (OTU) became dominant during the fertilization period, and it was most closely related to Pseudomonas putida.

CONCLUSIONS

The bacterial community structure in the treated area was markedly different from that in the control (non-fertilized) area during the fertilization period, but in the two areas it became similar at 14 weeks after the end of fertilization.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results suggest that the bacterial community structure was disrupted by the biostimulation treatment, but that it recovered immediately after the end of fertilization.

Transient suppression of X-ray-induced apoptosis by exposure to power frequency magnetic fields in MCF-7 cells

Epidemiological studies suggest that exposure to power frequency magnetic fields may be a risk factor for breast cancer in humans. To study the relationship between exposure to 60-Hz magnetic fields (MFs) and breast cancer, cell cycle distribution, apoptosis, and the expression of related proteins (p21, Bax, and Bcl-2) were determined in MCF-7 cells following exposure to magnetic fields (60 Hz, 5 mT) alone or in combination with X rays. It was found that exposure of MCF-7 cells to 60-Hz MFs for 4, 8, and 24 h had no effect on cell cycle distribution. Furthermore, 60-Hz MFs failed to affect cell growth arrest and p21 expression induced by X rays (4 Gy). Similarly, 60-Hz MFs did not induce apoptosis or the expression of Bax and Bcl-2, two proteins related to apoptosis. However, exposure of cells to 60-Hz MFs for 24 h after irradiation by X rays (12 Gy) significantly decreased apoptosis and Bax expression but increased Bcl-2 expression. The effects of exposure to 60-Hz MFs on X-ray-induced apoptosis and Bax and Bcl-2 expressions were not observed at 72 h. These data suggest that exposure to 60-Hz MFs has no effects on the growth of MCF-7 cells, but it might transiently suppress X-ray-induced apoptosis through increasing the Bcl-2/Bax ratio.

FDG uptake in the morphologically normal thymus: comparison of FDG positron emission tomography and CT

The purpose of this study was to evaluate the correlation between fluorine-18 fluorodeoxyglucose (FDG) thymic uptake and a normal appearing thymus on CT. Non-attenuation corrected FDG positron emission tomography (PET) data from 94 young persons (mean age 25.4 years, range 18-29 years) with a normal thymus diagnosed on CT were retrospectively evaluated. No subject had clinical symptoms suggestive of thymus-related disease or mediastinal tumour (follow-up period 6-69 months). PET images were visually assessed and the count ratio between the thymus and the lung (T/L ratio) was calculated. Increased FDG uptake occurred in 32 (34%) subjects. In these 32 cases, the T/L ratio was 2.86+/-0.49 (range 2.02-3.99). In 86 subjects whose CT images were available to calculate the CT attenuation of the thymus (CAT), the CAT value was -17.5+/-45.7 HU (range -103.6 HU to 79.9 HU). The T/L ratio correlated with the CAT value (r=0.58). CAT values in subjects with positive PET findings were significantly higher than CAT values in subjects with negative PET findings (p<0.001, unpaired t-test). These results suggest that even in young adults, if the thymus has a relatively high CT attenuation value, the presence of physiological thymic uptake in FDG-PET is a normal variant. In this study, the diagnosis of normal thymus was based on CT appearance and clinical course. Further studies are needed to clarify the relationship between histopathology and FDG uptake in the thymus.

Determination of polycyclic aromatic hydrocarbons by liquid chromatography-electrospray ionization mass spectrometry using silver nitrate as a post-column reagent

Liquid chromatography-electrospray ionization mass spectrometry (LC-ESI-MS) using silver nitrate as a post-column reagent has been used for the determination of 10 polycyclic aromatic hydrocarbons (PAHs) in river water. In this method, after all the PAHs were separated by reversed-phase liquid chromatography, analytes formed complexes with silver cation by mixing with silver nitrate solution. The complexes then transfer the molecular ion, [M]+, of the PAHs by charge transfer using in source collision-induced dissociation. The positive ion ESI mass spectra of all PAHs tested in this study showed [M]+ as the base peak and abundant [M+Ag]+, [2M+Ag]- with very weak or no [2M+Ag]+. For the sample extraction, several solid-phase extraction parameters using the blue-chitin column were optimized. The limits of detection (S/N=3) of all PAHs for the spiked river water sample ranged from 0.001 to 0.03 ng/ml, and the detector responses were linear up to I ng/ml (correlation coefficients > or =0.0998). Repeatability and reproducibility were in the range from 4.3 to 6.8% and from 6.2 to 9.5%, respectively.

Lidocaine potentiates atrial natriuretic peptide-induced relaxation of bovine tracheal smooth muscle

The effect of lidocaine on the changes in tension and guanosine 3',5'-cyclic monophosphate (cGMP) content induced by atrial natriuretic peptide (ANP) and nitric oxide (NO) was examined in bovine tracheal smooth muscle preparations contracted with methacholine (0.3 microM). Lidocaine (10 microM) did not affect the methacholine-induced tensions, whereas 100 microM lidocaine significantly (P<0.01) attenuated methacholine-induced ones. Treatment of the tracheal preparations with lidocaine (10 and 100 microM) significantly (P<0.05) augmented the relaxant responses to ANP, whereas the same procedure did not alter the responses to sodium nitroprusside, (+/-)-(E)-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexeneamide (NOR 3) or 8-bromo-cGMP. Lidocaine (100 microM) enhanced cGMP accumulation induced by ANP (0.1 microM) but not by sodium nitroprusside (0.3 microM). In contrast, mexiletine (100 microM), another class Ib antiarrhythmic, did not affect ANP- and sodium nitroprusside-induced relaxations. These results suggest that lidocaine augments ANP-induced relaxation and cGMP accumulation, probably by modulating activation mechanism of particulate guanylyl cyclase.

Inexplicable suppression of hepatic uptake of gallium-67, a case report

We describe here a case report of a patient with acute lymphocytic leukemia in whom hepatic gallium-67 (Ga-67) uptake was suppressed. The patient was hospitalized with increasing dyspnea. In Ga-67 scintigraphy, there was no hepatic uptake, although other physiological uptake was clearly observed. In addition, the scintigraphy showed increased accumulation in the right lung consistent with infection. We considered possible reasons for these findings. The patient had no history of chemotherapy or blood transfusion, and his iron metabolism was almost normal. He was not receiving any medication which might reduce hepatic blood flow. Blood chemistry suggested normal hepatic and renal function. The patient died from pneumonia 6 weeks later. The autopsy revealed extensive infiltration of the right lung with Bacillus cereus (B. cereus). Metabolic acidosis and/or iron utilization of B. cereus may induce both increased Ga-67 accumulation in the infected lesion and suppressed uptake in the liver, but these mechanisms could not explain normal physiological uptake in the other organs. This case warranted the further study of the hepatic Ga-67 uptake mechanism.

[Similarity between primary health care and health promotion]

Primary Health Care is recognized as a core health strategy in developing countries, proclaimed by the Declaration at Alma-Ata, while for industrialized countries, Health Promotion was stated in the Ottawa Charter. The concept of Primary Health Care, having been influenced by the Social Development movement for basic human needs in the 70s, is almost entirely consistent with Health Promotion, which is in accord with the principles of Human Development pronounced in the late 80s through the 90s. Thus, Health Promotion could be developed as a health strategy also in developing countries while Primary Health Care could similarly be adopted as a health strategy in the industrialized world.

18F-FDG PET detection of colonic adenomas

The adenomatous polyp of the colon is clinically important as a precursor of colonic cancer. The aim of this preliminary study was to evaluate the potential usefulness of (18)F-FDG PET for detecting adenomatous polyps of the colon.

METHODS

We performed a retrospective study of 110 subjects who underwent both PET study and total colonoscopy. On nonattenuation-corrected PET images, focal distinct FDG accumulation along the large intestine was considered a positive finding, and the PET results were compared with colonoscopic findings. Histology and adenoma size were determined by polypectomy.

RESULTS

Fifty-nine adenomatous polyps, 5-30 mm in size, were found in 30 subjects by total colonoscopy. PET findings were positive for 14 of the 59 adenomas (24%). The positivity rate for PET images rose with the increase in size of the adenomas; it was 90% in adenomas (9/10) that were > or =13 mm. The overall false-positive rate was 5.5% (6/110 subjects).

CONCLUSION

Increased glucose metabolism is observed in colonic adenomas, and detectability with PET increases with the increase in adenoma size. Adenomas are premalignant lesions, and it is important to realize that colonic adenomas may be found incidentally during an FDG PET study.

Acute and chronic haloperidol treatments increase parkin mRNA levels in the rat brain

Mutations in the parkin gene cause autosomal recessive juvenile parkinsonism. We examined the effects of acute and chronic treatment with haloperidol on parkin mRNA expression in the rat brain by reverse transcription-polymerase chain reaction. Acute haloperidol treatment (2 mg/kg) increased parkin mRNA levels in the striatum and nucleus accumbens but not in the medial prefrontal cortex and substantia nigra. Four-week-treatment with haloperidol decanoate (25 mg eq/kg) produced a significant increase in parkin mRNA levels in the striatum without affecting to those in the medial prefrontal cortex, nucleus accumbens and substantia nigra. These results suggest that Parkin may be involved in the haloperidol-induced synaptic plasticity, since Parkin regulates the turnover of the synaptic protein, CDCrel-1.

Completely inverse images in dual-isotope SPECT with Tl-201 and I-123 MIBG in a patient with myocarditis

Dual-isotope myocardial SPECT in a female patient with idiopathic myocarditis showed completely inverse images in Tl-201 and I-123 MIBG SPECT. In the dual-isotope SPECT performed 13 days after her admission, Tl-201 SPECT images showed reduced accumulation in the apex and normal accumulation in the other regions, whereas the corresponding I-123 MIBG SPECT images showed normal findings in the apex and reduced uptake in the other regions. These rare discrepancies were due to the difference in photon attenuation of the two isotopes in the apex and denervated-but-viable myocardium in the basal region, which were suggested by the following findings of gated perfusion SPECT and echocardiography. Gated SPECT with Tc-99m tetrofosmin performed 23 days after admission revealed normal myocardial perfusion and normal wall motion. Iodine-123 MIBG SPECT findings reflected impaired wall motion in echocardiography performed on admission, which resembles a phenomenon called "memory image" in coronary artery disease. The present case indicated a pitfall in interpreting dual-isotope imaging.

Comparison of image reconstruction algorithms in myocardial perfusion scintigraphy

The purpose of this study was to compare the clinical utility of two image reconstruction algorithms in myocardial perfusion SPECT (single-photon emission computed tomography): filtered back-projection (FBP) and ordered subset expectation maximization (OSEM). A rest/stress one-day protocol with 99mTc-MIBI or tetrofosmin was performed on 102 consecutive patients who underwent coronary angiography. After SPECT data acquisition, images were reconstructed with FBP and OSEM algorithms. We assessed diagnostic performance (sensitivity, specificity and accuracy) in detecting coronary artery stenosis and evaluated regional tracer uptake with a 4-point scoring system. Although there were no significant differences in diagnostic performance between FBP and OSEM reconstruction, the OSEM method yielded higher uptake in the RCA area than the FBP method by reducing the count-loss artifact due to hepatic uptake of the tracers. In addition, regional uptake in the LCX area was significantly lower in the OSEM image than in the FBP image; this phenomenon was observed mainly in patients with coronary stenosis and/or infarction in the LCX territory. In conclusion, OSEM and FBP offered comparable diagnostic performance in stress myocardial perfusion SPECT. The OSEM method contributed to reduction of the count-loss artifact in inferior and posterior walls and to easy recognition of hypoperfusion in the LCX area.

Automated on-line in-tube solid-phase microextraction followed by liquid chromatography/electrospray ionization-mass spectrometry for the determination of chlorinated phenoxy acid herbicides in environmental waters

A method for the determination of six chlorinated phenoxy acid herbicides in river water was developed using in-tube solid-phase microextraction (SPME) followed by liquid chromatography/electrospray ionization-mass spectrometry (LC/ESI-MS). In-tube SPME is an extraction technique for organic compounds in aqueous samples, in which analytes are extracted from a sample directly into an open tubular capillary by repeated draw/eject cycles of the sample solution. Simple mass spectra with strong signals corresponding to [M-H]- and [M-RCOOH]- were observed for all herbicides tested in this study. The best separation of these compounds was obtained with a C18 column using linear gradient elution with a mobile phase of acetonitrile-water containing 5 mmol l-1 dibutylamine acetate (DBA). To optimize the extraction of herbicides, several in-tube SPME parameters were examined. The optimum extraction conditions were 25 draw/eject cycles of 30 microliters of sample in 0.2% formic acid (pH 2) at a flow rate of 200 microliters min-1 using a DB-WAX capillary. The herbicides extracted by the capillary were easily desorbed by 10 microliters acetonitrile. Using in-tube SPME-LC/ESI-MS with time-scheduled selected ion monitoring, the calibration curves of herbicides were linear in the range 0.05-50 ng ml-1 with correlation coefficients above 0.999. This method was successfully applied to the analysis of river water samples without interference peaks. The limit of quantification was in the range 0.02-0.06 ng ml-1 and the limit of detection (S/N = 3) was in the range 0.005-0.03 ng ml-1. The repeatability and reproducibility were in the range 2.5-4.1% and 6.2-9.1%, respectively.

Late preconditioning in rat retina: involvement of adenosine and ATP-sensitive K(+) channel

To determine whether stimulation of adenosine receptors and opening of ATP-sensitive K(+) channels were involved in the protective effect of late preconditioning in the rat retina, rats were subjected to 60 min of retinal ischemia, and ischemic preconditioning was achieved by applying 5 min of ischemia 24 h before 60 min of ischemia. In non-preconditioned rats, cell loss in the ganglion cell layer and thinning of the inner plexiform and inner nuclear layer were observed 7 days after 60 min of ischemia. Ischemic preconditioning completely prevented the retinal tissue damage and 8-phenyltheophylline or 5-hydroxydecanoate reduced the protective effect of ischemic preconditioning. Therefore, stimulation of adenosine receptors and opening of ATP-sensitive K(+) channels might be involved in the mechanism of histological protection by late preconditioning in the retina.

Role of K+ channels in N-acetylprocainamide-induced relaxation of bovine tracheal smooth muscle

We examined the relaxant effects of N-acetylprocainamide, the major hepatic metabolite of procainamide, on bovine tracheal smooth muscle, focusing on the possible involvement of K+ channels. N-acetylprocainamide produced a concentration-dependent and full inhibition of the tension development elicited by methacholine (0.3 or 1 microM). The potency of N-acetylprocainamide in diminishing methacholine-elicited tension development was one-half of that of procainamide. By comparison, N-acetylprocainamide inhibited high-K+ (40 mM)-induced contraction more potently than procainamide though both inhibitions were largely reduced when compared to those against methacholine-induced contraction. Iberiotoxin (30 nM), Ba(2+) (1 mM) or a combination of both agents significantly attenuated the relaxant effect of N-acetylprocainamide on methacholine-induced contraction, whereas apamin (100 nM), 4-aminopyridine (300 microM), and glibenclamide (10 microM) did not affect it. These results suggest that N-acetylprocainamide, similar to procainamide, elicits tracheal smooth muscle relaxation mainly through the activation of plasma membrane K+ channels.

F-18 FDG uptake in endometrial cancer

Endometrial cancer, which is one of the most common malignant gynecologic diseases, was detected by F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in a 60-year-old woman with abdominal distention. FDG PET revealed heterogeneous and marked accumulation in the endometrium, which was thought to represent endometrial cancer. In addition, focal intense accumulation of FDG in both lungs suggestive of lung metastases were noted. Endometrial cancer and lung metastases were confirmed by endometrial biopsy and computed tomography of the chest, respectively.

A new isolation method for labyrinthulids using a bacterium, Psychrobacter phenylpyruvicus

A new isolation method for labyrinthulids, marine microbes with spindle-shaped vegetative cells and gliding movement, is presented. The method for isolating labyrinthulids has been found to be more difficult and less reproducible than that for thraustochytrids, classified in the same order. So far serum seawater agar fortified with antibiotics has been proposed to be the best for isolation of labyrinthulids. The method presented here involves placing plant samples on an agar medium on which a marine bacterium, Psychrobacter phenylpyruvicus, has been grown. The new method, which utilizes fallen mangrove leaves as source material, was more than twice as effective as isolation agar medium without the bacterium. The increased effectiveness appears to derive partly from the bacterial colonies' delaying extension of fungal mycelium. The bacterium was more effective for the isolation of labyrinthulids than either the bacterium Shewanella sp. or the yeast Rhodotorula rubra.

Mannosylerythritol lipid induces characteristics of neuronal differentiation in PC12 cells through an ERK-related signal cascade

Rat pheochromocytoma PC12 cells undergo neuronal differentiation in response to nerve growth factor (NGF). The differentiation involves protein kinase cascades that include the kinases MEK and ERK, as well as activation of the transcription factors c-Jun and c-Fos. We show here, that exposure of PC12 cells to mannosylerythritol lipid (MEL), a yeast extracellular glycolipid, enhances the activity of acetylcholinesterase and interrupts the cell cycle at the G1 phase, with resulting outgrowth of neurites and partial cellular differentiation. Treatment with MEL stimulates the phosphorylation of ERK to a similar extent as treatment with NGF, although, the appearance of phosphorylated ERK is somewhat delayed. Both the MEL-induced outgrowth of neurites and the increase in the activity of acetylcholinesterase are prevented by PD98059, a specific inhibitor of MEK. Northern blotting analysis of c-jun transcripts and analysis of transcription in PC12 cells of a c-jun/CAT reporter construct demonstrated a significant increase in the rate of transcription of the c-jun gene upon treatment with MEL. The sequence elements required for the MEL-mediated activation of transcription of the c-jun gene are located between nucleotides -126 and -79 in the 5' flanking region. Our results suggest that MEL induces characteristics of neuronal differentiation in PC12 cells, with transactivation of the c-jun gene, via an ERK-related signal cascade that is partially overlapping the pathways activated in response to NGF. These results might provide the groundwork for the use of microbial extracellular glycolipids as novel reagents for the treatment of cancer cells.

FDG accumulation in aortic walls

A 65-year-old woman with no symptoms underwent whole-body F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) for cancer screening. FDG accumulation was detected incidentally in her arterial walls, including the aortic wall. She had no history of inflammatory or cardiovascular disease. Although accumulation of FDG is well recognized in the aortic wall when vasculitis is present, this patient showed no symptoms of active vasculitis during the 22-month follow-up period after the PET study. The aortic wall might be a site where FDG accumulates physiologically in elderly persons.

Regeneration of the junctional epithelium and connective tissue after transplantation of detergent-processed allo-teeth

The authors have developed a new artificial dental implant and evaluated it in a dog model in terms of its potential to produce: I) regeneration of junctional epithelium; II) regeneration and attachment of connective tissue. The implants were constructed from allo-teeth. We removed the cell components from the periodontal ligaments of these teeth with a detergent (1% TritonX-100); the remaining acellular periodontal ligament acted as an extracellular matrix upon which regeneration and attachment could proceed. We placed 10 of these implants in the just-extracted sites of three beagle dogs. We observed regeneration of both junctional epithelium and connective tissue at all implant sites after 3 months. The connective tissue was attached in all cases. Use of the acellular periodontal ligament as an extracellular matrix may facilitate regeneration of host periodontal ligament tissue, thus contributing to recovery of host immunological defense and long-term oral function.

The role of the sentinel lymph node in gastrointestinal cancer

Evaluation of the clinical significance of the sentinel node concept in GI cancer has just begun. The authors' preliminary data, using intraoperative radiation techniques and the gamma probe, suggest that it is worthwhile to continue the evaluation of this procedure to determine its role in an accurate staging and a minimally invasive approach to GI cancers.

[Estimating cost functions of cancer screening programs provided by municipalities]

OBJECTIVE

To estimate cost functions of cancer screening programs for stomach, lung, colorectal, cervical, and breast cancers provided by municipalities and to describe the relationship between the costs and the scale of cancer screening programs.

METHODS

Subjects were all the municipalities in Japan. Questionnaires were sent to 3,182 subjects and 1,860 responses were received. Data obtained from questionnaires were the number of persons screened and the total cost of each program in the 1998 fiscal year. A cost function of each program was specified as a linear model, a power model, and a cubic model, and the fitness of each model was estimated.

RESULTS

Long-run cost functions of all the cancer screening programs allowed better explanation of the relationship between the number of persons screened and the total cost than short-run cost functions. The average costs of stomach, colorectal, and cervical cancer screening programs increased and the average cost of the lung cancer screening program decreased, as the number of persons screened increased. The cost function of the breast cancer screening program could not be identified.

CONCLUSIONS

It is necessary to estimate not only cost functions but also production functions of cancer screening programs using the data related to products, costs, and factors of production to evaluate the efficiency of cancer screening programs.

Application of positron emission tomography imaging to cancer screening

Whole-body positron emission tomography (PET) with(18)F-fluorodeoxyglucose (FDG) is a diagnostic modality that can noninvasively survey the entire body and sensitively detect various cancers. In this study, we examined the potential application of whole-body PET for cancer screening in asymptomatic individuals. PET was performed in conjunction with conventional examinations including physical examination, laboratory study, ultrasonography and chest computed tomography. Between September 1994 and March 1999, 3165 asymptomatic individuals participated in 5575 screening sessions (2017 men and 1148 women; mean +/- SD age, 52.2+/-10.4 years). Follow-up periods were no less than 10 months. PET results were compared with the screening outcomes. Within 1 year after screening, malignant tumours were discovered in 67 of the 3165 participants (2.1%). PET findings were true-positive in 36 of the 67 cancers (54%). Most of the 36 patients underwent potentially curative surgery; thus a wide variety of cancers were detected by PET at potentially curable stages. However, PET findings were false-negative in 31 of the 67 patients (46%). 14 of these 31 (45%) were of urological origin. FDG PET imaging has the potential to detect a wide variety of cancers at potentially curable stages. However, PET imaging is not suited to screening test of general population because PET examination involves substantial cost.

Intraaneurysmal Embolization for Wide-necked Aneurysms. Remodeling Technique, Combined Neck-Clipping and Coiling Therapy, Scaffolding Technique

SUMMARY

We reported the results of the endovascular treatment using Guglielmi detachable coil (GDC) for wide-necked aneurysms. Fourteen aneurysms were treated with remodeling technique. One aneurysm was performed endovascular treatment followed by partial neck clipping. The other was treated with scaffolding technique. All aneurysms could not be performed by conventional GDC treatment initially because of coil protrusion into the parent artery due to wide neck of these aneurysms. These aneurysms sited at anterior circulation system in 10 cases, and at posterior circulation system in 6 cases. Immediately after the procedure, the obliteration rate could be obtained complete occlusion in 3 cases, > 95% occlusion in 7 cases, > 90% occlusion in 3 cases and < 90% occlusion in 3 cases. In 14 patients followup angiography or magnetic resonance image (MRI) was carried out. The angiographic follow-up period is range from 2 to 19 months (mean: 10 months). The results of angiographical follow-up indicated increasing obliteration rate with all aneurysms except for 2 cases. In these 2 cases, the reembolization was needed for recanalization of the aneurysm. The clinical follow-up period is range form one to 26 months (mean: 15 months). There is no evidence of aneurysmal rupture and all cases have been survival without any permanent neurological deficits. The GDC treatment with additional technique (remodeling technique, combined neck-clipping and coiling therapy, scaffolding technique) provides safety and effectiveness, even if there are wide-necked aneurysms.

Multiple "mirror" aneurysms involving intracavernous carotid arteries and vertebral arteries: case report

BACKGROUND

Bilateral intracavernous carotid artery aneurysms are rare. Moreover, the proportion of vertebrobasilar aneurysms in association with multiple aneurysms is extremely low. We describe a rare case of "mirror" aneurysms on the bilateral intracavernous carotid and bilateral vertebral arteries.

CASE DESCRIPTION

A 54-year-old male suffered from ophthalmic pain and oculomotor palsy on the left side. Cerebral angiography disclosed a giant left cavernous aneurysm and large asymptomatic aneurysms on the right intracavernous carotid artery and bilateral vertebral arteries. The cavernous sinus syndrome on the left side was successfully treated by left carotid artery ligation. However, 2 years later, severe subarachnoid hemorrhage (SAH) occurred. Computed tomography revealed thick clots densely distributed in the basal cisterns and third and fourth ventricles, indicating that the SAH originated from one of the vertebral artery aneurysms. Consciousness disturbance progressed rapidly, leading to cardiopulmonary arrest.

CONCLUSION

The literature contains no case of mirror intracranial aneurysms involving both intracavernous carotid and vertebral arteries. Multi-staged surgical techniques with optimal combinations of direct clipping, ligation or trapping, and endovascular embolization may be essential for patients with multiple aneurysms to avoid SAH.

Possible involvement of endothelium-derived hyperpolarizing factor (EDHF) in the depressor responses to platelet activating factor (PAF) in rats

1. In anaesthetized rats, platelet activating factor (PAF; 1 microg kg(-1)) decreased mean arterial blood pressure by around 60 mmHg (n=18). This depressor response was completely blocked by the PAF antagonist, CV-6209 (1 mg kg(-1)), indicating the role of PAF-specific receptor in the response. 2. N(G)-nitro-L-arginine methyl ester (L-NAME; 50 mg kg(-1)), an NO synthase inhibitor, profoundly elevated systemic blood pressure (n=19), indicating an important role of NO in the basal blood pressure regulation. The depressor response to PAF (1 microg kg(-1)) normalized against that to sodium nitroprusside (SNP) (10 microg kg(-1)) was not substantially different between rats treated without and with L-NAME (n=4). In contrast, the depressor effect of acetylcholine (0.03 - 1.0 microg kg(-1)) normalized against that of SNP (10 microg kg(-1)) was significantly attenuated by L-NAME (n=5). 3. Charybdotoxin (0.4 mg kg(-1)) plus apamin (0.2 mg kg(-1)) significantly attenuated the depressor response to PAF (1 microg kg(-1)) (n=5) without affecting the blood pressure change due to SNP (1 mg kg(-1)) (n=3). Charybdotoxin (0.4 mg kg(-1)) (n=4) or apamin (0.2 mg kg(-1)) (n=4) alone did not affect the PAF-induced depressor response. 4. These findings suggest that EDHF may make a significant contribution to the depressor response to PAF in rats. Although NO plays the determinant role in the basal blood pressure regulation, its contribution to PAF-produced depressor response seems to be less as compared with that to the depressor response to acetylcholine.

[Recurrent episodes of fever of unknown origin as temporal lobe epilepsy]

A 67-year-old woman was admitted to our department for the recurrent fever of unknown origin that occurred once approximately every 1 month for the last 3 years. No clinical and laboratory abnormality were found, except an interictal EEG showing fronto-temporal spike discharges. During hospitalization a characteristic febrile episode was accompanied by automatism, thereby, it became clear that the undetermined periodic febrile episodes were due to temporal lobe epilepsy. In this case, the thermoregulatory center of the hypothalamus might be symptomatic zone of temporal lobe epilepsy.

Outlining the body contours with scattered photons in lymphoscintigraphy for sentinel nodes

Although lymphoscintigraphy is a useful method of detecting the sentinel nodes of malignancy, conventional lymphoscintigraphy images only the sentinel nodes without revealing their anatomical location. We, therefore, used scattered photons to attempt to outline the body contours of patients with either breast or esophageal cancer. Lymphoscintigraphy was performed 3 to 4 hours after the injection of 111 MBq of 99mTc tin colloid into the peritumoral region. Images were obtained with dual-energy windows of 130 to 150 keV for the primary photons and 70 to 110 keV for the scattered photons. The images constructed from the scattered photons clearly showed the contours of the body, and the fusion images constructed from the primary and scattered photons allowed for easy identification of the location of the sentinel nodes. The results of this study confirm that images obtained from scattered photons on lymphoscintigraphy are helpful in identifying the anatomical location of sentinel nodes.

Long-term treatment with haloperidol decreases the mRNA levels of complexin I, but not complexin II, in rat prefrontal cortex, nucleus accumbens and ventral tegmental area

The effect of long-term treatment with haloperidol on gene expression of the presynaptic protein complexins was investigated in the discrete brain regions of rats, using reverse transcription-polymerase chain reaction. Four-week-treatment with haloperidol decanoate (25 mg eq/kg) produced a significant decrease in the mRNA levels of complexin I in the medial prefrontal cortex, nucleus accumbens and ventral tegmental area, but not in the striatum and substantia nigra. No significant changes in complexin II mRNA levels were observed in any brain region examined here. The reduced expression of complexin I may be associated with the haloperidol-induced depolarization block of mesocorticolimbic dopamine neurons.

Involvement of K(+) channel in procainamide-induced relaxation of bovine tracheal smooth muscle

The relaxant effect of procainamide, a class Ia antiarrhythmic agent, was examined in bovine tracheal smooth muscle. Procainamide produced concentration-dependent decreases in tension and full relaxation in the preparations contracted with methacholine (0.3 microM). By comparison, in preparations contracted with 40 mM K(+), procainamide had only slight relaxant effects. The relaxant effects of cromakalim and salbutamol on 40 mM K(+)-contracted preparations were significantly (P<0.01) smaller than those on 0.3 microM methacholine-contracted ones. On the other hand, the concentration-response relationships for quinidine, lidocaine, mexiletine and propafenone were not so dramatically different between 0.3 microM methacholine- and 40 mM K(+)-contracted preparations. Tetraethylammonium (300 microM), iberiotoxin (30 nM) and Ba(2+) (1 mM) significantly (P<0.05) attenuated the relaxant effects of procainamide on methacholine-induced contractions, whereas apamin (100 nM), 4-aminopyridine (300 microM), and glibenclamide (10 microM) did not affect them. The inhibitory effect of a combination of iberiotoxin and Ba(2+) was greater than that of iberiotoxin or Ba(2+) alone (P<0.01). These results suggest that the activation of at least two types of K(+) (maxi-K(+) and inward rectifier K(+)) channels contributes to the procainamide-induced relaxation of bovine tracheal smooth muscle.

Properties of a bacterium which degrades solid poly(tetramethylene succinate)-co-adipate, a biodegradable plastic

Various microorganisms were screened for their ability to degrade poly(tetramethylene succinate)-co-(tetramethylene adipate) (PBSA). Strain BS-3, which was newly isolated from a soil sample, was selected as the best strain. From taxonomical studies, the strain was tentatively ascribed to belong to the genus Acidovorax, most probably to the species A. delafieldii. Strain BS-3 could degrade both solid and emulsified PBSA, and also emulsified poly(tetramethylene succinate). During the degradation, a lipase activity was observed in the culture broth. This lipase activity was induced more strongly by PBSA than by tributyrin or triolein which are typical substrates of lipase. These observations strongly suggest that this lipase was involved in the PBSA biodegradation in strain BS-3.

Cloning and expression of genes encoding meta-cleavage enzymes from 4,6-dimethyldibenzothiophene-degrading Sphingomonas strain TZS-7

Sphingomonas strain TZS-7 was reported as the first strain to have the ability to degrade 4,6-dimethyldibenzothiophene (4,6-dmDBT) by the ring-destructive pathway. Two genes for meta-cleavage dioxygenases were cloned from strain TZS-7. Expression of each gene showed that one enzyme was specific for 2,3-dihydroxybiphenyl while another was more specific for catechol. The genes for the two enzymes were named dmdC and catA. The analysis of deduced amino acid sequences indicates that CatA falls into the class of meta-cleavage dioxygenases acting on dihydroxylated monocyclic compounds and DmdC falls into the class of meta-cleavage dioxygenases acting on dihydroxylated polycyclic compounds.

Resistance to Friend murine leukemia virus infection conferred by the Fv-4 gene is recessive but appears dominant from the effect of the immune system

Fv-4 is a mouse gene that dominantly confers resistance to infection with Friend murine leukemia virus (F-MuLV) (S. Suzuki, Jpn. J. Exp. Med. 45:473-478, 1975). However, the resistance caused by Fv-4 is recessive in nude mice, which suggests that immunological effects play important roles in this resistance in vivo (K. Higo, Y. Kubo, Y. Iwatani, T. Ono, M. Maeda, H. Hiai, T. Masuda, K. Kuribayashi, F. Zhang, T. Lamin, A. Adachi, and A. Ishimoto, J. Virol. 71:750-754, 1997). To determine the immunological effect on the resistance in vivo, we infected immunologically immature newborn mice homozygous (Fv-4(r/r)) and heterozygous (Fv-4(r/-)) for Fv-4. Although the Fv-4(r/r) mice showed complete resistance to F-MuLV whether infected neonatally or as adolescents, the Fv-4(r/-) mice showed high sensitivity to viral proliferation and disease induction when infected as newborns but complete resistance when infected as adolescent mice. To confirm the immunological effect on the resistance in adolescent mice with the Fv-4(r/r) and Fv-4(r/-) genotypes, we examined the effect of an immunosuppressant drug, FK506, on the resistance. The mice with the Fv-4(r/r) genotype treated with FK506 still showed resistance, but the mice with the Fv-4(r/-) genotype became highly sensitive to F-MuLV infection. Flow cytometric analysis to detect the Fv-4 gene product showed that the Fv-4 gene product was expressed on the cells from newborn and adolescent mice. The Fv-4 gene product was also detected on the cells from the FK506-treated mice as well as on those from untreated mice. However, a quantitative difference in the gene product between the cells with the Fv-4(r/r) and Fv-4(r/-) genotypes was detected by indirect staining for flow cytometry. These results show that the resistance to F-MuLV infection conferred by the Fv-4 gene is originally recessive, but it looks dominant in adolescent mice mainly because of the effect of the immune system.

Identification of proteins of Escherichia coli and Saccharomyces cerevisiae that specifically bind to C/C mismatches in DNA

The pathways leading to G:C-->C:G transversions and their repair mechanisms remain uncertain. C/C and G/G mismatches arising during DNA replication are a potential source of G:C-->C:G transversions. The Escherichia coli mutHLS mismatch repair pathway efficiently corrects G/G mismatches, whereas C/C mismatches are a poor substrate. Escherichia coli must have a more specific repair pathway to correct C/C mismatches. In this study, we performed gel-shift assays to identify C/C mismatch-binding proteins in cell extracts of E. COLI: By testing heteroduplex DNA (34mers) containing C/C mismatches, two specific band shifts were generated in the gels. The band shifts were due to mismatch-specific binding of proteins present in the extracts. Cell extracts of a mutant strain defective in MutM protein did not produce a low-mobility complex. Purified MutM protein bound efficiently to the C/C mismatch-containing heteroduplex to produce the low-mobility complex. The second protein, which produced a high-mobility complex with the C/C mismatches, was purified to homogeneity, and the amino acid sequence revealed that this protein was the FabA protein of E.COLI: The high-mobility complex was not formed in cell extracts of a fabA mutant. From these results it is possible that MutM and FabA proteins are components of repair pathways for C/C mismatches in E.COLI: Furthermore, we found that Saccharomyces cerevisiae OGG1 protein, a functional homolog of E.COLI: MutM protein, could specifically bind to the C/C mismatches in DNA.

Bronchiolar disease: spectrum and radiological findings

Two types of bronchiole, the terminal bronchiole and the respiratory bronchiole, have structural and functional differences. The former is characterized as a conducting airway and the latter is closely related to a gas-exchange function as it has numerous alveoli on the wall. Therefore, the diseases occurring at bronchiole demonstrate different pathological, radiological and clinical pictures depending on which bronchiole is mainly involved. The disease that mainly involves the conducting airway is appreciated as a small airway disease. Constrictive bronchiolitis is a well-recognized entity classified in this category. Whereas the disease mainly involves the respiratory bronchiole and distal alveolar space, it is recognized as an interstitial and parenchymal disease. BOOP or RB-ILD is classified in this category. These two types of bronchiolar diseases reveal the contrast clinical pictures, including incidence, causative disease, response to the treatment, prognosis, respiratory function test as well as the radiological findings. This pictorial essay will illustrate the radiological features of the varieties of bronchiolitis.

Lidocaine potentiates the relaxant effects of cAMP-elevating agents in bovine tracheal smooth muscle

The effect of lidocaine on the relaxation and accumulation of adenosine 3',5'-cyclic monophosphate (cAMP) induced by salbutamol, forskolin and 3-isobutyl-1-methylxanthine (IBMX) was examined in bovine tracheal smooth muscle preparations precontracted with methacholine (0.3 microM). Lidocaine attenuated the methacholine-induced contraction in a concentration-dependent manner. Pretreatment of the preparations with lidocaine (100 microM) caused significant leftwards shifts of concentration/response curves for the relaxant responses to salbutamol, forskolin, and IBMX, whereas it did not change the responses to diltiazem. Similar leftwards shifts were observed when the preparations were treated with procaine (6 microM) or bupivacaine (40 microM). Lidocaine (100 microM) augmented cAMP accumulation induced by salbutamol (10 nM) and forskolin (1 microM). These results suggest that lidocaine augments the relaxant responses to cAMP-elevating agents through enhancement of cAMP accumulation.

Enantiomer separation of pharmaceuticals by capillary gas chromatography with novel chiral stationary phases

New chiral stationary phases of polydimethylsiloxane anchored with (S)-(-)-t-leucine derivatives were provided for use in enantiomer separation of pharmaceuticals by capillary gas chromatography. Fifteen pharmaceuticals were separated into their enantiomeric pairs by converting them into pentafluoropropionyl and heptafluorobutyryl derivatives. The separation factor and resolution obtained from the new phases were superior to those from the conventional Chirasil-Val capillary column.