rap1 p21 regulates the interaction of ras p21 with RGL, a new effector protein of ras p21

We have recently found that ralGDS family members (RGL and ralGDS) are putative effector proteins of ras p21. rap1 p21 is a small GTP-binding protein which has the same amino acid sequence as the effector loop of ras p21. We examined the effect of rap1 p21 on the interaction of ras p21 with RGL. The GTP-bound form of rap1 p21 interacted with RGL as well as did ras p21. rap1 p21 inhibited the interaction of ras p21 with RGL. RGL was phosphorylated by cyclic AMP-dependent protein kinase (protein kinase A). Phosphorylation of RGL did not affect its binding to ras p21 and rap1 p21 under the conditions that phosphorylation of Raf-1 reduced its affinity for ras p21. These results demonstrate that rap1 p21 but not protein kinase A regulates the interaction of ras p21 with RGL and suggest that rap1 p21 and protein kinase A may cooperate to distinguish the signal or ras p21 to RGL from that to Raf-1.

Role of nitric oxide during carrageenan-sensitized endotoxin shock in mice

We have previously clarified that sensitization with a sulfated polygalactose, carrageenan (CAR), enhances endotoxin-induced tumor necrosis factor (TNF) production and lethality in mice. The present study was performed to examine the role of nitric oxide (NO) in CAR-sensitized septic mice with two different types of NO synthase (NOS) inhibitors, a non-selective inhibitor to NOS subtypes, N omega-nitro-L-arginine methyl ester (L-NAME), and a selective inhibitor to inducible NOS, aminoguanidine. Seven or eight-week-old male ddY mice were given 5 mg of CAR intraperitoneally as a primer. Then, 5 micrograms of lipopolysaccharide (LPS) was injected into the tail vein 16 hours later the pretreatment. Marked synthesis of NO was induced in CAR-sensitized mice, as indicated by the high plasma levels of the stable endproducts, NO2-/NO3- peaking at 12 hr after the LPS challenge. The peak values at 12 hr after the LPS challenge were dependent on the dose of CAR with 1 to 5 mg, although the injection with 10 mg of CAR was adversely inhibited NO production compared with 5 mg of CAR. The LPS challenge was followed by either L-NAME (0.25, 0.5 or 1 mg) or aminoguanidine (1, 2 or 4 mg) in the septic mice sensitized with 5 mg of CAR. L-NAME reduced the plasma NO2-/NO3- level in a dose-dependent fashion, although it augmented liver injury, as measured by plasma levels of ornithine carbamyltransferase (OCT) and the LPS-induced lethality in a dose-dependent fashion. In contrast, aminoguanidine did not significantly deteriorate either liver injury or lethality in spite of the decrease of NO endproducts in a similar fashion to L-NAME. These findings suggest that the inhibition of constitutive NOS is detrimental and augments LPS-induced liver injury and subsequent lethality.

Variable clinical symptoms in familial amyotrophic lateral sclerosis with a novel point mutation in the Cu/Zn superoxide dismutase gene

We report a novel missense point mutation in exon 4 of the Cu/Zn superoxide dismutase (SOD) gene of affected members of a Japanese kindred segregating familial amyotrophic lateral sclerosis (FALS) through at least three successive generations. The mutation, which is predicted to cause the replacement of isoleucine at codon 104 by phenylalanine (I104F), is associated with a significant reduction in Cu/Zn SOD enzyme activity but results in a highly variable clinical phenotype. Age at onset varied from 6 to 55; the initial symptoms occurred in either the lower or upper extremities in different family members. The duration of the disease varied from 3 to 38 years. Two subjects, aged 59 and 34, remained asymptomatic until their death from other causes, although their offspring carrying the same mutation have already developed clinical evidence of the disease. These results suggest that FALS from this novel I104F mutation shows considerable clinical variation.

[Assessment for intelligence on patients with Pick's disease]

In contrast to Alzheimer's disease, it is unclear whether the MMS (Mini-Mental State) or the RCPM (Raven's Coloured Progressive Matrices) is clinically useful as a mental test battery in patients with Pick's disease, and it has not been fully evaluated whether intelligence of these patients really deteriorate along with the staging of dementia. The present study aimed to make these problems clear. We administered the MMS and the RCPM to 17 cases of Pick's disease, including 7 cases with predominantly frontal lobe atrophy and 10 cases with predominantly temporal lobe atrophy, which were all classified into 3 groups according to the staging of dementia by using the NM scale (New Clinical Scale for Rating of Mental States). We also investigated whether these patients had "Denkfaulheit" (laziness of thinking) and/or "gogi" aphasia (word meaning aphasia), which may affect performances on the mental test batteries. Two cases with predominantly frontal lobe atrophy and 5 cases with predominantly temporal lobe atrophy were assessed by the same examinations several years later. In cases with predominantly frontal lobe atrophy, all the patients presented with "Denkfaulheit". However, the mean RCPM score was normal in the mildly damaged patients, suggesting that their intelligence were relatively preserved. In the moderately and severely damaged groups, their intelligence could not be assessed owing to their severe "Denkfaulheit". In cases with predominantly temporal lobe atrophy, all the patients had "gogi" aphasia and 3 cases of the severely damaged groups presented with "Denkfaulheit".(ABSTRACT TRUNCATED AT 250 WORDS)

Involvement of protein phosphatase-1 in cytoskeletal organization of cultured endothelial cells

The phosphorylation and dephosphorylation of cytoskeletal proteins regulate the shape of eukaryotic cells. To elucidate the role of serine/threonine protein phosphatases (PP) in this process, we studied the effects of calyculin A (CLA), a potent and specific inhibitor of protein phosphatases 1 (PP-1) and 2A (PP-2A) on the cytoskeletal structure of cultured human umbilical vein endothelial cells (HUVECs). The addition of CLA (5 min) caused marked alterations in cell morphology, such as cell constriction and bleb formation. Microtubules and F-actin were reorganized, becoming markedly condensed around the nucleus. Although the fluorescence intensity of phosphoamino acids was not significantly different according to immunocytochemistry between cells with and without CLA, polypeptides of 135, 140, 158, and 175 kDa were specifically phosphorylated on serine and/or threonine residues. There was no significant effect on tyrosine residues. The effects of CLA on cytoskeletal changes and protein phosphorylation were almost completely inhibited by the non-selective kinase inhibitor, K-252a. The effect of CLA on cell morphology was at least 100 times more potent than that of okadaic acid, consistent with the inhibitory potency against PP-1. The catalytic subunit of PP-1 was also identified in HUVECs by Western blotting with its monoclonal antibody antibody. These results suggest that PP-1 is closely involved in sustaining the normal structure of the cytoskeleton.

Role of neutrophils in radical production during ischemia and reperfusion of the rat brain: effect of neutrophil depletion on extracellular ascorbyl radical formation

A growing body of experimental data indicate that oxygen radicals may mediate the brain injury during ischemia-reperfusion. One potential source of oxygen radicals is activated neutrophils. To study the role of neutrophils in radical production during cerebral ischemia-reperfusion, we evaluated the effects of depletion of circulating neutrophils by administration of an anti-neutrophil monoclonal antibody (RP3) on radical formation in rats with 1-h middle cerebral artery (MCA) occlusion. In the present study, we employed a new electron spin resonance method coupled with brain microdialysis. The method uses the endogenous ascorbyl radical (AR) concentration as a marker of oxygen radicals and requires no spin-trapping agents. In the vehicle controls, extracellular AR decreased during MCA occlusion. After reperfusion, AR significantly increased at 30 min and 1 h, returned to near basal level until 2 h, and increased again at 24 h after reperfusion. In the rats treated with RP3, AR decreased during MCA occlusion to the same extent as in the vehicle control. However, RP3 treatment completely inhibited the increase in extracellular AR after reperfusion. RP3 treatment exerted no effect on the changes in extracellular ascorbate or tissue PO2 throughout the experimental period. In conclusion, neutrophils are a major source of oxygen radicals during reperfusion after focal cerebral ischemia.

[Comparison between anomia with word comprehension difficulty and Gogi aphasia due to lobar atrophy]

We used naming and pointing tests and a proverb completion task to compare two cases of aphasia that exhibited a selective disturbance of word processing. One patient had anomia with word comprehension difficulty due to partial ablation of the left temporal lobe and the other patient had Gogi aphasia due to lobar atrophy with left temporal predominance. We presented 90 pictures of common objects divided into 9 categories in the naming and pointing tests, and used 10 well-known Japanese proverbs as stimuli in the proverb completion task. Performance of the naming and pointing tests was severely impaired in both patients. In the patient with anomia, words the patient could not name or point to varied from session to session and phonemic cue effects were frequently observed. The proverb completion phenomenon was positive. These findings indicate that the patient had an obstruction of the access route to the intact word store or a partial rarefaction of the word store itself. In the patient with Gogi aphasia, the words the patient could not name or point to were consistent from one occasion to another, and no phonemic cue effects or signs of familiarity were observed at all. The proverb completion phenomenon was totally negative. These findings indicate that the patient has lost the word store itself. MR images in the case of anomia revealed a lesion extending from the anterior to the central portion of the inferior part of the left temporal lobe. In the case of Gogi aphasia, the MR images displayed knife-edged focal atrophy in the anterior aspect of both temporal lobes, more prominently on the left.(ABSTRACT TRUNCATED AT 250 WORDS)

Monitoring of exposure to methylpentanes by diffusive sampling and urine analysis for alcoholic metabolites

OBJECTIVES

To investigate the possibilities of personal ambient monitoring and biological monitoring for methylpentane isomers.

METHODS

The performance of activated carbon cloth to absorb 2- and 3-methylpentane was studied by experimental vapour exposure followed by solvent extraction and gas chromatography (GC). Urine from workers and rats exposed to 2- and 3-methylpentane was analysed by GC with or without acid or enzymatic hydrolysis.

RESULTS

Carbon cloth absorbed 2- and 3-methylpentane linearly to exposures up to eight hours and to 400 ppm, and was sensitive enough to detect a 15 minute peak of exposure. The two isomers were clearly separated from hexane on a DB-1 column. For analysis of the urine, enzymatic hydrolysis was superior to acid hydrolysis. Exposure of rats to methylpentane vapours showed that 2-methyl-2-pentanol and 3-methyl-2-pentanol were excreted in urine in proportion to the dose of 2-methylpentane and 3-methylpentane, respectively. 2-Methyl derivatives of 1-, 3-, and 4-propanol, 2-methylpentane-2,4-diol, and 3-methyl-2-pentanol were minor metabolites. Analysis of urine from the exposed workers showed that 2-methyl- and 3-methyl-2-pentanol are leading urinary metabolites after exposure to the corresponding methylpentane.

CONCLUSIONS

Diffusive sampling is applicable to monitor 2- and 3-methylpentane vapours as is the case for hexane vapour. 2-Methyl-2-pentanol and 3-methyl-2-pentanol will be markers of occupational exposure to 2-methylpentane and 3-methylpentane, respectively. Also, 2-methylpentane-2,4-diol might be a marker of exposure to 2-methylpentane.

Serotonin-induced 5-HT1A receptor desensitization in C6BU-1 glioma cells transfected with 5-HT1A receptor gene

In this study, it has been clearly demonstrated that a selective 5-hydroxytryptamine (5-HT)1A agonist, 8-OH-2-(di-n-propylamino)-tetraline (8-OH-DPAT, 1 microM) significantly inhibited forskolin (10 microM)-stimulated cyclic AMP (cAMP) accumulation in the C6BU-1 cells transfected with 5-HT1A receptor gene. Further, this 8-OH-DPAT-induced inhibition of forskolin-stimulated activity was significantly attenuated after pre-exposure to 5-HT (10 microM) for 12 h. Spiperone (10 microM), a 5-HT1A and 5-HT2A antagonist, prevented 5-HT-induced desensitization of 5-HT1A receptor, but a selective 5-HT2A receptor antagonist, ketanserin, did not. In addition, pre-exposure to a selective 5-HT2A agonist, 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (DOI, 10 microM), for 24 h did not alter the inhibitory effect of 8-OH-DPAT on forskolin-stimulated cAMP accumulation in these transfected cells, suggesting that prolonged exposure to 5-HT induced 5-HT1A receptor desensitization, mediated by 5-HT1A receptor but not 5-HT2A receptors.

Pharmacology of CS-866, a novel nonpeptide angiotensin II receptor antagonist

CS-866, (5-methyl-2-oxo-1,3-dioxolen-4-yl)methoxy-4-(1-hydroxy-1- methylethyl)-2-propyl-1-(4-[2-(tetrazol-5-yl)-phenyl]phenyl)met hylimidazol- 5-carboxylate, a prodrug type angiotensin receptor antagonist, is deesterified to the active acid, RNH-6270. RNH-6270 inhibited [125I]angiotensin II binding to bovine adrenal cortical membranes (angiotensin AT1 receptors) with an IC50 value of 7.7 nM, but not [125I]angiotensin II binding to bovine cerebellar membranes (angiotensin AT2 receptors), indicating the selectivity of the compound for angiotensin AT1 receptors. In guinea pig aortas, RNH-6270 reduced the maximal response of the concentration-contractile curve for angiotensin II (pD'2 = 9.9), but had no effect on the contractile response induced by phenylephrine or KCl. In conscious rats, intravenously injected RNH-6270 inhibited angiotensin II-induced pressor responses in a dose-dependent manner, and orally administered CS-866 produced a long-lasting inhibition of angiotensin II pressor responses. SK&F-525A, a P-450 inhibitor, suppressed the angiotensin II inhibitory effect of losartan, but not that of CS-866. These results demonstrate that RNH-6270 is a potent and AT1-selective angiotensin receptor antagonist and that, after oral administration, CS-866 has a long-lasting angiotensin II inhibitory action which is not affected by drug metabolizing enzymes in the liver.

Localization of rat endothelin-converting enzyme to vascular endothelial cells and some secretory cells

Endothelin is a potent vasoconstrictive peptide that is produced by vascular endothelial cells; it is formed from its precursor, big endothelin, by endothelin-converting enzyme (ECE). In this work, ECE was studied using specific monoclonal antibodies. In immunoblotting, ECE was estimated to be a 300 kDa protein on SDS/PAGE under non-reducing conditions, and 130 kDa under reducing conditions. Cross-linking experiments revealed that ECE is composed of two disulphide-linked subunits. Localization of ECE was studied at the cellular and subcellular levels in various rat tissues and cells. High-level expression of ECE was observed in membrane fractions of simian virus 40-transformed rat endothelial cells by immunoblotting, but the immunoreactive band was absent form aortic smooth muscle cells and cytosolic fractions of endothelial cells. In immunohistochemical analysis, ECE was found to be localized in the endothelial cells of the aorta, lung, kidney, liver and heart. Confocal immunofluorescent microscopy showed that most of the ECE in endothelial cells and cells transfected with ECE cDNA was clustered along the plasma membrane. Intact COS or CHO cells transfected with ECE cDNA rapidly and efficiently cleaved big endothelin-1 added to the culture medium. Thus endothelial cells express ECE on the plasma membrane and the active site of the enzyme faces outside the cells, i.e. it is an ectoenzyme. Other than endothelial cells, ECE was also present in some secretory cells. The enzyme was abundant in the adrenal gland, and localized in chromaffin cells. ECE was also highly condensed in pancreatic islet beta cells. It is concluded that ECE and endothelin may be involved in the regulated secretion of hormones.

Acute effect of calcium blocker on renal hemodynamics in diabetic spontaneously hypertensive rat

This study was done to examine the acute effect of a calcium channel blocker on renal hemodynamics in the diabetic spontaneously hypertensive rat (SHR). Streptozotocin was used to induce diabetes, and barnidipine (B) was used as a calcium blocker. Renal blood flow (RBF) and glomerular filtration rate (GFR) were measured by a clearance method with paraaminohypurate (PAH) and inulin, respectively. Rats were divided into two groups: nondiabetic SHR, N-SHR; diabetic SHR, DM-SHR. B increased RBF in N-SHR (7.44 +/- 1.99 versus 8.50 +/- 1.97 mL/min/g.kw) while there was no change in DM-SHR. B reduced renovascular resistance (RVR) in DM-SHR and N-SHR. B increased GFR in N-SHR (1.15 +/- 0.24 versus 1.34 +/- 0.25 mL/min/g.kw), in spite of no changes in DM-SHR. B did not modify filtration fraction (FF) in both groups. These results indicate (1) in SHR, B exerts beneficial effects on hypertensive renal damage by reducing mean arterial pressure (MAP), RVR, RBF, and GFR; (2) in diabetic SHR, B is less effective in restoring renal hyperfiltration in spite of reducing RVR.

Radiation myelopathy: a clinicopathological study with special reference to correlation between MRI findings and neuropathology

We describe magnetic resonance imaging (MRI) and neuropathological findings in a patient with chronic progressive radiation myelopathy (CPRM). An 81-year-old man with esophageal cancer underwent radiotherapy. Four years later he developed a progressive neurological deficit below the irradiated level of the spinal cord. Neurological examination revealed spastic paraplegia. MRI findings showed an area of high signal intensity on T2-weighted images of the thoracic spinal cord. On the basis of clinical and MRI findings, we diagnosed his condition as CPRM. MRI performed thirteen months after onset of neurological signs revealed mild atrophy of the spinal cord detected on T1-weighted images and an area of high signal intensity within the spinal cord detected on T2-weighted images. Neuropathological examination revealed findings consistent with radiation myelopathy. We speculate that the area of high signal intensity within the spinal cord detected on T2-weighted images might be a result of proliferation of small vessels, which was discovered upon autopsy.

Dysplasia and HPV infection initially detected by DNA analysis in cytomorphologically normal cervical smears

OBJECTIVE

We examined the relationship between the risk of dysplasia and human papillomavirus (HPV) infection initially detected by DNA analysis in Japanese women with cytomorphologically normal cervical smears.

METHOD

We applied the polymerase chain reaction method to detect HPV DNA in 800 women and subsequently followed up 49 women positive for HPV DNA.

RESULTS

HPV 16 or HPV 18 DNA was detected in 53 (6.6%) of 800 women with normal smears (negative). During the follow-up period (23 months), the presence of HPV DNA could not be detected in 41 (83.7%) of 49 women after its initial presence. The remaining eight women had repeated HPV DNA, and four of these eight women had lesions that progressed to mild dysplasia.

CONCLUSION

The results indicated that some women with cytomorphologically normal smears may have HPV DNA which can be transient, and persistence of HPV types 16 or 18 DNA plays an important role in the pathogenesis of cervical dysplasia.

Detection of an increase in ascorbate radical in an irradiated experimental tumour system using ESR

We measured Asc.- (ascorbate radical) produced by the reaction of AscH- (ascorbic acid) with HO. or O2.- after irradiation in mouse. It is possible to measure Asc.- easily using ESR and a dialysis method in which Asc.- was collected at room temperature in the interstitial fluid through the dialysis membrane. After irradiation, Asc.- increased in both normal muscle and tumour tissues (SCC-VII) in proportion to the radiation dose. Asc.- increased after treatment with the agents H2O2 and FeCl2, while it decreased after treatment with SOD and catalase. These results suggest that the amount of HO. and O2.- produced is reflected in the Asc.- production. Also, the increase in Asc.- production when WR-2721 was administered prior to irradiation was less than for experiments in which irradiation only was performed. This method is useful for the following reasons. First, no special treatment, such as freezing of the sample, and no administration of noxious agents are necessary to measure Asc.-. Second, irradiation using a dose of only a few Gy shows an increase in production of Asc.-. Third, this method does not require removal of organs. Using this method, Asc.- can serve as an indicator of the amount of HO. and O2.- produced by irradiation in vivo.

Nitrite, nitrate and cGMP in the cerebrospinal fluid in degenerative neurologic diseases

To investigate whether nitric oxide (NO) plays a role in degenerative neurologic disease (DND), we measured nitrite, nitrate and cyclic GMP in cerebrospinal fluid (CSF) samples from patients with Parkinson's disease (PD), spinocerebellar ataxia (SCA) and amyotrophic lateral sclerosis (ALS). We found no significant change in CSF nitrite, nitrate or cyclic GMP in patients with any DND compared with control values. These results suggest that NO production is preserved in PD, SCA and ALS.

[Nerve sutures and nerve grafts for repairing a gap in peripheral nerve injury: an experimental study]

An experimental study was performed using the canine sciatic nerve in order to compare the efficacies of a vascularized trunk graft (VTG), a free trunk graft (FTG), a vascularized cable graft (VCG), a free cable graft (FCG) and a two stage procedure (TSP) for the repair of a peripheral nerve defect. Both a 4 cm, and a 5 cm nerve defect was repaired using each method, and also a 6 cm defect, using VCG and FCG. After 24 weeks, the intraneural blood flow (IBF) was measured in the 4 cm defect group, and the recovery of nerve regeneration and muscle reinnervation were evaluated by motor nerve conduction velocity, wet muscle weight, and histological examinations of the nerve and the muscles. VTG and VCG both demonstrated superior IBF. The IBF after TSP was less than after VTG and VCG but greater than after FTG and FCG. In the 4 cm defect group, VTG showed the most favorable recovery in both the axonal regeneration and muscle reinnervation and was followed by VCG. Although the recovery after FTG, FCG and TSP appeared to be worse than after VTG and VCG, there was no significant difference. In the 5 cm defect group, VTG showed the most favorable recovery followed by VCG and FCG. For axonal regeneration, FTG was significantly worse than VTG, VCG and FCG. TSP was worst within the 5 cm defect group for muscular reinnervation, although it showed somewhat better axonal regeneration than FTG. In the 6 cm defect group, no significant difference was found between VCG and FCG for the axonal regeneration. Clinically, TSP is used for repairing a short nerve defect just beyond the critical distance that cannot be overcome by a primary end-to-end suture. Nerve grafting, other than FTG, appeared to be the most reliable method of bridging a long nerve defect, and FCG might be the most practical method.

The characteristics of renal hemodynamics in diabetic spontaneously hypertensive rats in comparison with diabetic Wistar-Kyoto rats

Diabetic Sprague-Dawley (SD) rats are known to exhibit renal hyperfiltration and hyperperfusion accompanied by renal hypertrophy. We examined whether such characteristics of renal hemodynamics in diabetic SD rats are also observed in diabetic spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats. SHR and WKY rats were divided into four groups: D-S, diabetic SHR; N-S, nondiabetic SHR; D-W, diabetic WKY rats; and N-W, nondiabetic WKY rats. Streptozotocin (STZ), 90 mg, was intraperitoneally injected to induce diabetes. Renal blood flow (RBF) and glomerular filtration rate (GFR) were measured by a clearance method with paraaminohypurate and insulin, respectively, 7-12 days after diabetes induction. In D-S and D-W, there was no increase in the kidney weight and RBF, in spite of significant increases in GFR and fasting blood sugar levels. These results indicate that, in both WKY and SHR, diabetes does not always produce renal hypertrophy and does not result in an increase in RBF.

Adrenomedullin as a novel antimigration factor of vascular smooth muscle cells

The present study investigated the effect of adrenomedullin, a novel vasorelaxant peptide, on the migration of cultured rat vascular smooth muscle cells (SMCs) by using the Boyden-chamber method. Fetal calf serum (FCS) and platelet-derived growth factor (PDGF)-BB strongly stimulated SMC migration. Adrenomedullin clearly inhibited SMC migration stimulated with 5% and 10% FCS in a concentration-dependent manner. The migration induced by 10 and 25 ng/mL PDGF-BB was also inhibited by adrenomedullin in a concentration-dependent manner. Inhibition by adrenomedullin of FCS- and PDGF-induced SMC migration was paralleled by an increase in the cellular level of cAMP. In fact, the percent increase in cAMP level was strongly correlated with the percent decrease in migration activity of SMCs after treatment with adrenomedullin. 8-Bromo cAMP, a cAMP analogue, reproduced the inhibition by adrenomedullin of FCS- and PDGF-induced SMC migration. An activator of adenylate cyclase, forskolin, also reduced FCS- and PDGF-induced SMC migration. These data indicate that adrenomedullin inhibits the migration of SMCs stimulated with FCS and PDGF, probably through a cAMP-dependent process. On the basis of these results and the finding that adrenomedullin is synthesized in and secreted from vascular endothelial cells, adrenomedullin may play a role as a local antimigration factor in some pathophysiological states.

Dietary intake of cadmium and lead among the general population in Korea

This survey was conducted in Seoul, Pusan, Chunan, and Haman in Korea to clarify cadmium and lead burden in the general Korean populations in terms of dietary intake of cadmium and lead and the concentrations of the two metals in blood. People who participated in the study were 141 healthy nonsmoking women aged 21-56 years. Determination of cadmium and lead in 24-hr food duplicates and blood samples was carried out by graphite furnace atomic absorption spectrophotometry. The geometric means for the four sites in combination were 21.2 micrograms/day for dietary cadmium, 20.5 micrograms/day for dietary lead, 1.27 ng/ml for blood cadmium, and 44.3 ng/ml for blood lead. Cadmium intake from boiled rice accounted for 23% of total daily cadmium intake. The counterpart value for lead intake from boiled rice was 12%. Blood cadmium levels and dietary cadmium intake were lower and blood lead level and dietary lead intake were higher in Korean women than in Japanese women. The values for dietary cadmium are similar to, and the values for dietary lead are somewhat lower than, the levels reported from Europe and the United States. Dietary intake was the main source of cadmium exposure, whereas lead exposure was from both ambient air and foods in the Korean population.

Enkephalin-immunoreactive fastigial neurons in the rat cerebellum project to upper cervical cord segments

By using enkephalin immunohistochemistry combined with retrograde fluorescent labelling, a great majority of neurons in the rat cerebellum sending their axons to the spinal cord were shown to contain enkephalin immunoreactivity. These neurons were numerous and clustered in the fastigial nucleus but far less abundant in other cerebellar nuclei. Enkephalin-immunoreactive fibers present in the ventral horn and the central cervical nucleus of upper cervical cord segments almost completely disappeared contralaterally following kainic acid-induced cell loss in the fastigial nucleus. The results indicate that fastigial and some other cerebellar nucleus neurons provide enkephalin-containing projections toward these spinal sites.

Immunohistochemical evidence for enkephalin and neuropeptide Y in rat inferior colliculus neurons that provide ascending or commissural fibers

Enkephalin- and neuropeptide Y-expressing neurons which offer commissural axons or axons toward auditory thalamus were identified in the rat inferior colliculus. These neurons exhibited a differential distribution pattern. The results provide evidence for regional specificity and chemical heterogeneity of neurons in the auditory midbrain.

Identification and characterization of two isoforms of an endothelin-converting enzyme-1

We report the cloning and sequencing of 5'-terminal region of a beta form of rat ECE-1 cDNA which is different only in its N-terminal amino-acid sequence to the cDNA we have cloned previously (alpha form [K. Shimada et al. (1994) J. Biol. Chem. 269, 18275-18278]). No significant difference was found in the specific activity and substrate specificity between the two isoforms. The expression level of ECE-1 alpha mRNA was higher than that of ECE-1 beta in various rat cells and tissues, suggesting that the physiologically important isoform is ECE-1 alpha. The present findings verified the presence of two forms of ECE-1 over many species, which are created probably through alternative splicing.

[Measurement of radical in irradiated experimental tumor: direct detection of ascorbate radical in mice using ESR]

We measured ascorbate radical (AR) produced by the reaction of ascorbic acid (Asc) with hydroxyl radical (.OH) or superoxide (O2-) after irradiation in normal muscle and SCC-VII tumor of C3H/He mice. AR can be measured using electron spin resonance (ESR) equipment and the dialysis method. The tube for collecting AR was inserted such that the dialysis membrane was in contact with the normal thigh or the center of the tumor lesion. The AR in the interstitial fluid around the membrane was collected through the dialysis membrane. After irradiation with 10 Gy, AR increased in both the normal muscle and tumor tissue; the percent increase was 53.1% for normal muscle tissue and 33.8% for tumor tissue. The maximum percent increases in AR in the normal muscle and the tumor tissue were 11.7 and 9.5% for 2.5 Gy, 28.5 and 18.5% for 5 Gy, 53.1 and 33.8% for 10 Gy, and 88.5 and 44.8% for 15 Gy, respectively. The amount of AR increased to maximums of 144.3% and 160.1% after treatment with H2O2 and FeCl2, respectively, while it decreased to minimums of 65.3% and 81.3% after treatment with superoxide dismutase (SOD) and catalase, respectively. These results suggest that the amount of .OH and O2- is reflected in the amount of AR production. This method is useful for the following reasons. First, no special treatment, such as freezing of the samples, and no administration of noxious agents are necessary. Second, irradiation using a dose of only several Gy shows an increase in the production of AR. Third, this method is less invasive.(ABSTRACT TRUNCATED AT 250 WORDS)