Expression of basic fibroblast growth factor receptor messenger RNA in the periinfarcted brain tissue

The present study examined whether expression of basic fibroblast growth factor receptor (bFGFR) messenger ribonucleic acid (mRNA) was upregulated by focal ischemia. We have studied the in situ hybridization autoradiography for bFGFR mRNA in the rat model of middle cerebral artery (MCA) occlusion. Male Wistar rats were used for occlusion of the left MCA, and were sacrificed 1, 3, 7 and 14 days after MCA occlusion. In situ hybridization was performed on the brain sections of these animals and sham controls by using 35S-labeled antisense and sense (control) RNA probes for rat bFGFR. Expression of bFGFR mRNA was observed in the periinfarcted area of the rats within 1-14 days after MCA occlusion. Expression was evident in the whole hemisphere of the infarcted side, especially at 1 and 3 days after ischemia, but no expression was detected in the contralateral side. On microautoradiograms, the signals of bFGFR mRNA were detected in both neurons and non-neural cells located in the periinfarcted area. Upregulation of bFGFR mRNA detected in the periinfarcted brain tissue suggests that receptor-mediated action of bFGF may be related to preservation of neurons injured by ischemia.

Association between blood polychlorinated biphenyl concentration and serum triglyceride level in chronic "Yusho" (polychlorinated biphenyl poisoning) patients

The association between blood polychlorinated biphenyl (PCB) concentration and serum triglyceride level was investigated in 259 "Yusho" patients (PCB poisoning) who underwent health examinations for Yusho in 1988. Geometric means of PCB and triglyceride were 3.84 ppb (95% confidence interval: 3.54-4.17) and 114.3 mg/dl (106.6-122.6), respectively. Both correlation and multiple regression analyses showed a weak but statistically significant correlation between these two variables. The mean triglyceride level adjusted for age and sex was then calculated for comparison among four PCB levels, using analysis of covariance. This indicated a progressive increase with increasing PCB: 98.36, 117.78, 117.84, and 127.65 mg/dl at < 2.7, 2.7+, 4.1+, and 6.1+ ppb, respectively (F = 2.01, P = 0.113). Comparing PCB levels, the difference in adjusted mean triglyceride levels was marginally significant between the first and second (P = 0.088), and the first and third quartiles (P = 0.066), and reached significance between the first and fourth quartiles (P = 0.021). Thus, a weak but significant association between blood PCB and serum triglyceride was observed in the patients 20 years after exposure, although their blood PCB and serum triglyceride were relatively close to the normal levels.

Transport mechanism of glutamate by hypotonic-treated glial plasmalemmal vesicles from rat hippocampus. Effects of concentration gradients of Na+ and K+ and of ionophores

Recently, we isolated a novel subcellular fraction of glial plasmalemmal vesicles (GPV), which showed a higher activity of Na(+)-dependent glutamate transport than synaptosomes (Nakamura et al., 1993). In order to study kinetically the glutamate transport mechanism, we measured the reaction under various ionic conditions both inside and outside the vesicles. The vesicles treated hypotonically and preloaded with KCl could take up glutamate in the presence of external Na+. The level of glutamate uptake was dependent on external concentrations of NaCl ([NaCl]o) and competitively inhibited by [KCl]o. However, it was dependent on [KCl]i, and competitively inhibited by [NaCl]i. The activation and inhibition constants of K+ were about 30 mM inside and 20 mM outside, respectively, whereas those of Na+ were 140 mM outside and 4 mM inside, respectively. These results suggest that the transport carrier molecules work asymmetrically to the membranes. Nigericin and monensin, acidic ionophores for K+ and Na+, respectively, inhibited the glutamate uptake. On the other hand, valinomycin, a neutral ionophore for K+, elevated the uptake level, suggesting that the inside-negative membrane potential induced by K+ diffusion enhances the uptake activity. We conclude that glutamate transport by glial cells requires both external Na+ and internal K+ and is regulated by the membrane potential.

Evaluation of masked neurological disorders in the chronic stage after middle cerebral artery occlusion in rats--methamphetamine-induced rotation and regional glucose metabolism in basal ganglia

Neurofunctional changes in rats in the chronic stage of focal cerebral ischemia induced by left middle cerebral artery (MCA) occlusion were examined. Neurological disorders and behavioral changes were observed with or without methamphetamine administration. Metabolic changes in the basal ganglia following methamphetamine intraperitoneal injection were evaluated by [14C]deoxyglucose autoradiography 30 days after occlusion. Neurological examination revealed persistent spontaneous rotation to the lesioned side in two of 18 rats, and forelimb flexion to the lesioned side in nine of 18 rats during a 28-day observation period after occlusion. Intraperitoneal administration of methamphetamine (4 mg/kg) induced full 360 degrees rotation toward the lesion side in 14 of 17 rats. The number of rotations was inversely correlated with the size of the intact striatum on the lesion side, especially in rats with cerebral infarct located only in the striatum. Rats with extensive cortical lesion in addition to striatal lesion did not demonstrate this relationship. Deoxyglucose autoradiography in methamphetamine-untreated rats showed symmetrical local cerebral glucose utilization in the basal ganglia except for the subthalamic nucleus, striatum and sensorimotor cortex. Autoradiography in methamphetamine-treated and MCA-occluded rats showed a remarkable increase in glucose utilization in the anterior striatum, entopeduncular nucleus, substantia nigra pars reticulata, and sensorimotor cortex contralateral to the occlusion side, but not on the lesioned side. Rotational movements observed in methamphetamine-treated rats are related to lack of stimulation of the basal ganglia system on the ischemic side.(ABSTRACT TRUNCATED AT 250 WORDS)

Treatment of severe localized cerebral vasospasm following recurrent hemorrhage from middle cerebral artery aneurysm--case report

A 52-year-old female presented with localized but severe cerebral vasospasm induced by recurrent aneurysmal subarachnoid hemorrhage. The middle cerebral artery (MCA) aneurysm was clipped and the subarachnoid hematoma evacuated 1 day after recurrent hemorrhage. The cerebral vasospasm, localized in a region near the MCA aneurysm, was reduced by papaverine and nicardipine vasodilating agents delivered via an Ommaya cerebrospinal fluid reservoir placed at craniotomy.

Mutagenicity and antimutagenicity of extracts of three spices and a medicinal plant in Thailand

Three kinds of spices (caraway, coriander and black pepper seeds) and a medicinal plant called 'tong tak' in Thai (Baliospermum axillar, a species of the spurge family) were fractionated into hot water, methanol and hexane extracts. These extracts were not mutagenic for Salmonella typhimurium strains TA98 and TA100 by the Ames assay. However, when the extracts were treated with nitrite, samples of the water and methanol extracts were mutagenic for strain TA100 without metabolic activation. The mutagenicity of the nitrite-treated methanol and hot water extracts of black pepper was highest (8380 and 22,200 His+ per 0.1 g of spice powder, respectively), and that of the nitrite-treated hot water extracts of caraway and tong tak was moderate. The hot water extracts were examined for their antimutagenic activity against mutagenicity induced by various carcinogens by the Ames assay, using the preincubation technique. The tested samples (equivalent to 1-2 mg of spice powder) reduced the mutagenicity induced by 2.7 nmole (397 ng) of N-methyl-N'-nitro-N-nitrosoguanidine by more than 84%, and that induced by dimethylnitrosamine (1.48 mg) or ICR-170 (10 ng) by 30-60%. However, they did not inhibit the mutagenic activity of 1-nitropyrene, 3-nitrofluoranthene, AF-2, methyl methanesulfonate, N-ethyl-N'-nitro-N-nitrosoguanidine, 2-aminoanthracene, 2-acetylaminofluorene, benzo[a]pyrene or IQ.

Boronate-containing polymer as novel mitogen for lymphocytes

A novel water-soluble polymer (poly(AAm-co-PBA)) was synthesized by radical copolymerization of 3-acrylamidophenylboronic acid with acrylamide and evaluated as synthetic mitogen of lymphocytes. Boronic acid was introduced in the polymer as recognition site of sugar residues existing on the plasma membrane surface of lymphocyte, since it makes a covalent bonding with polyol compounds including sugars. Obvious increase in [3H]thymidine incorporation of lymphocytes was observed when murine spleen lymphocytes were cultured with poly(AAm-co-PBA), while little proliferative response of lymphocytes was observed in the presence of the homopolymer of acrylamide, the polymer without boronic acid moiety. This suggests that proliferation of lymphocytes was induced through the binding of phenylboronic acid moiety in poly(AAm-co-PBA) with glycoproteins existing on the plasma membrane surface of lymphocytes. Further, poly(AAm-co-PBA) was found to induce even the proliferation of B cell-depleted population of lymphocytes, suggesting T cell stimulation by this boronate-containing polymer.

Glial plasmalemmal vesicles: a subcellular fraction from rat hippocampal homogenate distinct from synaptosomes

By a Percoll density-gradient centrifugation of rat hippocampal homogenate, we found a novel subcellular fraction (specific gravity approximately 1.046 g/ml), besides synaptosomes (approximately 1.060 g/ml), which showed a high activity of Na(+)-dependent glutamate uptake. The initial rate of the glutamate uptake in this fraction was as high as twice that in synaptosomes. Activities of choline acetyltransferase and high affinity choline uptake were, on the other hand, much lower. gamma-Aminobutyric acid uptake activity was nearly equivalent in both fractions. Electron microscopic observations revealed that the fraction was morphologically different from synaptosomal or myelin fractions, but mainly consisted of two different types of empty membrane vesicles; irregular (0.3-0.8 micron in diameter) and spheroid type (0.2 micron). The immunoreactivity to glial fibrillary acidic protein was appreciably high in this fraction. The marker enzyme analysis showed the fraction was rich in plasma membranes. On the basis of these results, the fraction is termed glial plasmalemmal vesicles (GPV). We analyzed kinetically the reaction of Na(+)-dependent glutamate uptake by GPV comparing with that by synaptosomes. Km values for glutamate in GPV was 4.7 microM and Vmax was 33 nmol/mg/min, while in synaptosomes 11 microM and 17 nmol/mg/min, respectively. Hill coefficients of Na+ activation in GPV and synaptosomes were 1.1 and 2.0, respectively. Thus, the mechanism or transporter molecule in glial cells for Na(+)-dependent glutamate transport is likely to be different from that in neurons.

(2S,3S,4R)-2-(carboxycyclopropyl)glycine, a potent and competitive inhibitor of both glial and neuronal uptake of glutamate

The effects of several diastereoisomers of L-2-(carboxycyclopropyl)glycine (CCG) on L-glutamate uptake were compared among three different preparations, glial plasmalemmal vesicles (GPV), synaptosomes and cultured astrocytes from rat hippocampus. The (2S,3S,4R)-isomer (L-CCG-III) inhibited a Na(+)-dependent high-affinity L-glutamate uptake in GPV and synaptosomes in a dose dependent manner at a micromolar range. The potency was quite similar to that of L-threo-beta-hydroxyaspartate in both subcellular fractions and much higher than L-aspartate-beta-hydroxamate, which were known as potent inhibitors of glutamate uptake. The (2S,3R,4S)-isomer (L-CCG-IV) also inhibited the glutamate uptake in GPV and synaptosomes, but it was about 100 times less active than L-CCG-III. The (2S,3S,4S)- and (2S,3R,4R)-isomers (L-CCG-I and L-CCG-II, respectively) hardly showed any inhibitory action on the glutamate uptake. Dixon plot analysis of the initial uptake rate revealed that the inhibition was in a competitive manner and the value of the inhibition constant (Ki) was about 1 microM in both GPV and synaptosomes. L-CCG-III effectively inhibited the glutamate uptake by cultured hippocampal astrocytes as well. These results suggested that L-CCG-III inhibited the glutamate uptake in both neurones and glial cells of the mammalian central nervous system in a similar manner.

[Usefulness of serum pancreatic phospholipase A2 determination in patients with various pancreatic diseases]

A radioimmunoassay kit (SHIONORIA P-PLA2) to measure human serum pancreatic phospholipase A2 (P-PLA2) concentrations was evaluated for their basic properties and clinical usefulness. The performance of the kit was found to be quite satisfactory. To test its clinical usefulness, specimens mainly from patients with pancreatic diseases were obtained and examined for serum P-PLA2 levels. All serum specimens from patients with acute pancreatitis (n = 7) were found to have elevated levels of serum P-PLA2. In patients with chronic pancreatitis (n = 93) and pancreatic cancer (n = 37), serum P-PLA2 levels showed a wide range of distribution, from abnormally elevated values to abnormally low values. We compared these data with those of other pancreatic markers such as: amylase, elastase 1, trypsin, and PSTI. Among these, P-PLA2 was highly specific to pancreatic disease and best represented the state of pancreatic disorders. Abnormally elevated levels of serum P-PLA2 concentrations seem to reflect the inflammation of pancreas, while abnormally low levels indicate the hypofunction of pancreatic exocrine glands. These results suggest that the measurement of serum P-PLA2 concentrations is a useful diagnostic test for pancreatic disorders.

Two new members of the maf oncogene family, mafK and mafF, encode nuclear b-Zip proteins lacking putative trans-activator domain

The v-maf oncogene of the avian musculoaponeurotic fibrosarcoma virus, AS42, encodes a nuclear protein which contains a characteristic b-Zip domain. By screening a chicken embryo fibroblast (CEF) cDNA library under moderately stringent hybridization conditions, we picked up a series of cDNA clones for a novel maf-related gene which we named mafK. We also identified another maf-related gene named mafF by screening a chicken genomic library using a mafK probe. Structural analyses suggested that the mafK and mafF genes consist of three exons. The exon-intron structures of the two genes resemble each other, but differ from that of the chicken c-maf gene. As compared to the c-Maf protein, the proteins encoded by the mafK and the mafF genes are rather small in size and lack the regions corresponding to the amino terminal acidic domain present in the c-Maf protein. On the other hand, the structures of the b-Zip domain are well conserved among these Maf-related proteins. When overexpressed by using an avian retroviral vector, the two maf-related genes did not induce morphological transformation of CEF cells but induced colony formation in soft agar with very low efficiencies. With a specific antibody, the MafK protein was detected predominantly in the nuclei of the cells infected with the virus which carries the mafK gene. Tissue distributions of these three maf-family genes are different from one another, probably reflecting their different functions in vivo.

Dantrolene protects against ischemic, delayed neuronal death in gerbil brain

The effect was examined of dantrolene, a drug for malignant hyperthermia acting through preventing release of Ca from the ryanodine-type intracellular stores in muscle cells, on ischemic delayed neuronal death in field CA1 of gerbil hippocampus. Dantrolene (1.6 mM in concentration, 3 microliters each in volume), when administered bilaterally in the lateral ventricles 30 min after reperfusion after transient forebrain ischemia for 3 min at 37 degrees C, significantly protected against the neuronal death. It is proposed that the dantrolene-sensitive (most likely, the ryanodine-type) intracellular Ca stores in CA1 pyramidal cells play a pivotal role in the development of ischemic neuronal damage.

Site-directed mutagenesis of a hexapeptide segment involved in substrate recognition of phenylalanine dehydrogenase from Thermoactinomyces intermedius

Phenylalanine dehydrogenase from Thermoactinomyces intermedius and leucine dehydrogenase from Bacillus stearothermophilus show a 59% sequence similarity in their substrate-binding domains, although their substrate specificities are different. We prepared a phenylalanine dehydrogenase mutant enzyme whose inherent hexapeptide segment (124F-V-H-A-A-129R) in the substrate-binding domain was replaced by the corresponding part of leucine dehydrogenase (M-D-I-I-Y-Q) in order to investigate the mechanism of substrate recognition by phenylalanine dehydrogenase. The catalytic efficiencies (kcat/Km) of the mutant enzyme with aliphatic amino acids and aliphatic keto acids as substrates were 0.5 to 2% of those of the wild-type enzyme. In contrast, the efficiencies for L-phenylalanine and phenylpyruvate decreased to 0.008 and 0.035% of those of the wild-type enzyme, respectively. These results suggest that the hexapeptide segment plays an important role in the substrate recognition by phenylalanine dehydrogenase.

Steroid hormones protect spinal cord neurons from glutamate toxicity

The effects of steroid hormones on glutamate neurotoxicity were examined in cultured spinal cord neurons. The extent of neuronal damage, produced by glutamate exposure for 15 min, was estimated based on the activity of lactate dehydrogenase released from degenerated neurons to the media during 24 h of post-exposure incubation. This damage was dependent on the glutamate concentrations used. The addition of dexamethasone, a synthetic steroid, in post-exposure media remarkably reduced the extent of damage in a dose-dependent manner. The half effective concentration for the steroid was approximately 0.7 microM, which was in the range of pharmacological concentration. Dexamethasone was effective even when it was added 2 h after glutamate exposure. Some endogenous steroid hormones--aldosterone, progesterone and testosterone--also showed similar neuroprotective effects. However, cholesterol, a precursor of these steroid hormones, had no effect on glutamate neurotoxicity. This direct protective effect on neurons against glutamate neurotoxicity may explain, at least partly, the mechanisms of beneficial effects of steroid hormones on in vivo spinal cord injury.

Biodistribution of micelle-forming polymer-drug conjugates

Polymeric micelles have potential utility as drug carriers. To this end, polymeric micelles based on AB block copolymers of polyethylene oxide (PEO) and poly(aspartic acid) [p(Asp)] with covalently bound Adriamycin (ADR) were prepared. The micelle forming polymer-drug conjugates [PEO-p(Asp(ADR)] were radiolabeled and their biodistribution was investigated after intravenous injection in mice. Long circulation times in blood for some compositions of PEO-p[Asp(ADR)] conjugates were evident, which are usually atypical of colloidal drug carriers. This was attributed to the low interaction of the PEO corona region of the micelles with biocomponents (e.g., proteins, cells). Low uptake of the PEO-p(Asp(ADR)] conjugates in the liver and spleen was determined. The biodistribution of the PEO-p[Asp(ADR)] conjugates was apparently dependent on micelle stability; stable micelles could maintain circulation in blood, while unstable micelles readily formed free polymer chains which rapidly underwent renal excretion. Long circulation times in blood of PEO-p(Asp(ADR)] conjugates are thought to be prerequisite for enhanced uptake at target sites (e.g., tumors).

Analysis of micelle formation of an adriamycin-conjugated poly(ethylene glycol)-poly(aspartic acid) block copolymer by gel permeation chromatography

The micelle-forming behavior of a drug-block copolymer conjugate (adriamycin-conjugated poly(ethylene glycol)-poly(aspartic acid) block copolymer; PEG-P[Asp(ADR)]) was analyzed by gel permeation chromatography (GPC). Four compositions of the conjugates were observed to form micellar structures in aqueous media, and their micelle-forming behavior was found to be dependent on the composition and media. These micelles did not reach equilibrium within short time periods like low molecular weight surfactants. One composition formed stable micelles in the presence of serum.

Biological activities of the intestinal microflora in mice treated with antibiotics or untreated and the effects of the microflora on absorption and metabolic activation of orally administered glutathione conjugates of K-region epoxides of 1-nitropyrene

To elucidate the effects of the intestinal microflora on absorption and activation of glutathione conjugates of 4,5-epoxy-4,5-dihydro-1-nitropyrene (1-NP 4,5-oxide) and 9,10-epoxy-9,10-dihydro-1-nitropyrene (1-NP 9,10-oxide), we investigated the biological activities of the microflora in specific-pathogen-free (SPF) mice and SPF mice treated with various antibiotics and established the methodology of antibiotic treatment to eliminate the intestinal microflora. Mice were given various kinds of antibiotics by intragastric gavage twice a day for five days. A mixture of antibiotics bacitracin (BC), neomycin (NM) and streptomycin (SM) was the most effective in reducing the various activities of the intestinal microflora. The treatment decreased the bacterial counts and the activities of enzymes of the intestinal contents cysteine conjugate beta-lyase (beta-lyase), beta-glucuronidase and nitroreductase which were derived from the intestinal microflora, but did not affect the activities of gamma-glutamyltransferase and aminopeptidase which were derived from host tissue cells. Furthermore, the treatment did not affect absorption of glucose from the intestinal tract, body weight or liver enzyme activities. The treatment with only an aminoglycoside antibiotic, kanamycin or NM, decreased neither the number of anaerobes in the intestine nor the beta-lyase or nitroreductase activities from the intestinal contents. Glutathione conjugates of [3H]-1-NP oxides were administered to two groups of ICR mice that had been treated with antibiotics (BC, NM, SM) or saline (control group) orally. The radioactivity in the blood increased and reached the maximum level 2 or 3 h after administration of the conjugates in the control group; however, that in the antibiotic-treated group was only slightly increased if at all. Excretion of [3H]-labeled metabolites into the urine was approximately 20% of the total dose in the control group, but it was < 2% in the antibiotic-treated group during 48 h. After 48 h, DNA in the lower intestinal mucosa was extracted and the DNA adducts were analyzed by the 32P-postlabeling method. Three new DNA adducts were detected in the lower intestinal mucosa of the control group but not of the antibiotic-treated group. These results suggest that the intestinal microflora plays an important role in absorption of the metabolites of glutathione conjugates of 1-NP oxides from the intestinal tract and activation of the metabolites in the intestine.

[Laboratory findings in the medical examination of chronic "Yusho" (PCB poisoning) patients: with special reference to blood PCB and serum triglyceride]

Associations of blood PCB concentration with serum levels of triglyceride, gamma-GTP, total-, and conjugated-bilirubin were investigated in "Yusho" patients twenty years after outbreak, using the information obtained from the medical examinations in 1988 and 1989. Study subjects were 259 patients in 1988, and 268 patients in 1989, including 190 patients who consecutively received both examinations. Blood PCB concentrations (mean +/- SE) were 4.78 +/- 0.22 ppb in 1988, and 4.47 +/- 0.17 ppb in 1989. The results of blood-chemical analysis were compared among four categorized concentrations of blood PCB, using the analysis of variance. Significant difference was observed for triglyceride (1988: p < 0.025, 1989: p < 0.005), but not for gamma-GTP, total-, and conjugated-bilirubin. In 1988, the mean triglyceride levels were 108, 137, 145, and 166 mg/dl at < 2.7, > or = 2.7, > or = 4.1, and > or = 6.1 ppb of blood of PCB, respectively. Corresponding figures in 1989 were 106, 129, 154, and 156 mg/dl at < 2.7, > or = 2.7, > or = 4.0, and > or = 5.7 ppb of blood PCB, respectively. Thus, clear positive association between blood PCB and serum triglyceride was observed in the patients twenty years after exposure.

Morphometric studies on the juxta-insular and tele-insular acinar cells of the pancreas in normal and streptozotocin-induced diabetic rats

In the present study on the exocrine pancreas, stereological techniques were applied at the level of electron microscopy to confirm morphological differences between juxta-insular and tele-insular acinar cells of normal rats and to evaluate the effect of B cell secretion on these differences in streptozotocin-diabetic rats. As no similar data have been previously published, we conducted a systematic sampling analysis with special reference to the acinar cell volume, the granule content and the nuclear size. In the normal rats, the juxta-insular acinar cell had an average volume of 918 microns3 and contained 420 zymogen granules which occupied 10.2% of the cell. In tele-insular acini, the average cell volume was estimated at 755 microns3 and the cell contained 231 zymogen granules which amounted to 6.8% of the cell. The juxta-insular acinar cell was 18% larger in size and contained 45% more zymogen granules, but no difference was observed in the size of zymogen granules. In addition, the numerical density of cell nuclei was slightly larger in the tele-insular acini in spite of the similarity in the volume density and diameter of the nuclei in the cells of the two areas. In the streptozotocin-induced diabetic rats, no differences were observed in the cell volume and the zymogen granule content between the juxta- and tele-insular acini. These data suggest that the morphological inhomogeneity in the pancreatic acini is caused by the influence of B cell secretion on the activity of the juxta-insular acini.

Structure-function analysis of the maf oncogene product, a member of the b-Zip protein family

The v-maf oncogene, identified as the transforming gene of the avian retrovirus AS42, encodes a protein containing a b-Zip motif. From this structural feature, the v-Maf protein was expected to form a dimer and function as a nuclear DNA-binding protein. In this study, we demonstrate that this protein indeed localizes predominantly in the nucleus and forms a homodimer through its leucine zipper structure. To delineate the structural requirement for the transforming activity, we constructed and characterized a panel of v-maf mutants harboring various deletions or point mutations. A region of about 100 amino acid residues located near its carboxyl terminus, which contains the b-Zip motif, was found to be essential for the basal transforming activity of v-Maf on chicken embryo fibroblasts. On the other hand, the amino-terminal two-thirds of the v-Maf protein seems to play a role in potentiating the transforming activity of v-Maf. It was also found that the c-maf proto-oncogene, without any structural modification in its protein-coding region, could transform cells as efficiently as could the v-maf oncogene when transduced by a retroviral vector. Thus, it is probably deregulated expression that makes the v-maf gene oncogenic. In addition, we discovered one point mutation, altering the structure of the b-Zip domain, which further enhances the transforming activity of the v-maf oncogene. Such mutant will be useful in exploring the mechanism of action of the Maf protein.

Mutagenicity of the bile of dogs with an experimental model of an anomalous arrangement of the pancreaticobiliary duct

To learn the reasons for the high incidence of biliary carcinoma in patients with anomalous arrangement of the pancreaticobiliary duct (APBD) mutagenicity of the bile of APBD-modeled dogs that had received a dorsal pancreatico-cholecystostomy was assayed by the Ames Salmonella mutation test. The bile from two out of 18 APBD dogs was mutagenic for Salmonella typhimurium strain TA98 under the condition of metabolic activation by rat liver S9 fraction, while the bile from 17 normal dogs was not mutagenic. Furthermore, the bile from five APBD dogs i.p. administered 1-nitropyrene (1-NP), which is a typical environmental mutagen, was more mutagenic for strain TA98 than that from 1-NP-treated normal dogs. The bile from the APBD dogs had very high amylase activity, indicating that the bile contained pancreatic juice as a result of the pancreatico-cholecystostomy. When pancreatic juice from a normal dog was added to the bile from 1-NP-treated normal dogs, mutagenicity of the bile increased 1.6- to 2.0-fold. Furthermore, sulfatase increased the mutagenic activity of the bile in the presence of the pancreatic juice. HPLC revealed that the bile from a 1-NP-treated APBD dog contained mutagenic 1-nitro-6/8-hydroxypyrene and 1-nitro-3-hydroxypyrene, while bile from a 1-NP-treated normal dog did not contain these deconjugated products. The pancreatic juice from a normal dog had very high gamma-glutamyltransferase (GGT) and aminopeptidase activities and low sulfatase activity, but it had no beta-glucuronidase activity. In addition, the bacteria that easily infect the biliary duct of APBD dogs, Escherichia coli, Klebsiella, Enterobacter and Proteus, had high beta-glucuronidase activity. In particular, Klebsiella showed a very high sulfatase activity. These results suggest that pancreatic juice enzymes and bacteria infecting the biliary duct deconjugate the detoxified mutagens in the bile and induce mutagenicity of the bile from APBD dogs or APBD patients.

A histochemical study on glycoconjugates in epithelial cells in the distal colonic mucosa of adult and developing mice

Glycoconjugates were histochemically studied in the distal colon of developing ICR mice in view of the presence of goblet and vacuolated cells. Alcian blue, high iron diamine and periodic acid-Schiff stainings were performed to characterize glycoconjugates. In addition, two lectins, Ulex europeus agglutinin I and Limax flavus agglutinin, were applied to detect fucosyl and sialyl residues, respectively. The reactivities to these stainings, noted from day 18 of gestation, did not seem to undergo any major change throughout their development. The present results suggest that: 1) goblet cells secrete sulfated glycoconjugates containing fucosyl and sialyl residues as terminal sugars; 2) vacuolated cells have glycoconjugates containing sialyl residues but no or few fucosyl residues nor sulfonic groups, and certain sialyl residues in the glycoconjugates are probably O-acetylated or O-acylated at least in part; and 3) the brush border of absorptive cells contains glycoconjugates sialylated and fucosylated to same extent but rarely sulfated. Since glycoconjugates elaborated by goblet and vacuolated cells differ from each other, one should be fully aware of the presence of these two types of mucin-producing cells in the distal colon.

[Evaluation of preoperative diagnosis of primary hyperparathyroidism--special reference to normocalcemic cases]

Since the opening of our clinic 117 years before, we have treated 62 cases of primary hyperparathyroidism (PHPT), among which there were 6 cases (1 male, 5 females) whose calcium levels fell within the normal range. However, in all these cases the serum ionized calcium (Ca++) levels and the serum ionized calcium/calcium ratio (Ca++/Ca ratio) were high. Moreover, in comparing them with hypercalcemic patients (56 cases), the serum Ca++ levels were significantly lower, but the (Ca++/Ca ratio) was significantly higher. Also, the excised weight of 606.1 +/- 520.3 mg was significantly smaller than that of hypercalcemic patients, which was 1,967.9 +/- 2,086.3 mg. Preoperative locations showed significantly lower levels in comparison with hypercalcemic patients by all methods including computed tomography (CT), ultrasonography, scintigraphy, and magnetic resonance imaging (MRI). In normocalcemic patients following parathyroidectomy, although the decrease in serum calcium levels was not significant, the serum Ca++ levels and the Ca++/Ca ratio decreased significantly, so that not only are they useful parameters for preoperative diagnosis of PHPT, but they are also considered necessary and indispensable for observation of the post-operative course and judging therapeutic effects including the operation. Based on our study we concluded that in multiple and recurrent stone formers with normal range of serum Ca levels, regardless of the presence or absence of local diagnosis, if the serum Ca++ level and Ca++/Ca ratio are high, existence of primary hyperparathyroidism must be suspected, and adequate treatments should be instituted promptly.

A case of aldosterone producing adenoma associated with high PRA after long-term angiotensin converting enzyme inhibitor treatment

A 62-year-old patient with non-insulin dependent diabetes (NIDDM) was admitted to our hospital for blood pressure control. He had been treated with angiotensin converting enzyme inhibitor (ACEI) for 7 years and showed marked hypokalemia with increased urinary potassium excretion. Hormonal examination revealed a normal plasma aldosterone concentration and increased plasma renin activity (PRA, 13.4 ng/ml/h), so potassium losing nephropathy was suspected. After discontinuation of the ACEI, PRA decreased to normal. An adrenal adenoma was found on abdominal magnetic resonance imaging (MRI) and adrenalectomy was performed to confirm aldosterone producing adenoma (APA). Although ACEIs are said not to alter PRA in APA, this drug was primarily responsible for the increased PRA in this case. This is a rare case of APA, which showed markedly increased PRA during ACEI treatment.

[Two cases of Morgagni's hernia]

Two cases of Morgagni's hernia comprising protrusion of the omentum alone are reported. The treated patients were 65- and 63-year-old obese women. They were referred to our hospital because of chest pain or vomiting accompanied by abnormal shadow in right cardiophrenic angle on chest roentgenogram. Computed tomogram (CT) demonstrated a mass of fat density behind the sternum for the both patients. The first patient was diagnosed as Morgagni's hernia by pneumoperitoneum, and surgical repair was done by the transabdominal approach. Magnetic resonance imaging (MRI) was carried out for the second patient, and showed intrathoracic mass lesion which was continuous with the subphrenic tissue. Although the second patient was diagnosed as mediastinal lipoma, median sternotomy revealed that the mass lesion was Morgagni's hernia. Postoperatively, both patients recovered uneventfully. The Morgagni's hernia has been reported to be about 3% of all diaphragmatic hernia. This disease may be discovered either because it causes respiratory or gastrointestinal complaints, or because an abnormal shadow in right cardiophrenic angle on a chest roentgenogram. If air-filled structures are present in the hernia, a barium study will confirm the diagnosis. In a case with a hernia containing only omentum, the diagnosis is difficult. CT has been regarded as the procedure of choice by several authors. The coronal and sagittal views of MRI can demonstrate the relationship between the herniated structures and the diaphragm, heart, pericardium. We emphasize the role of MRI for the diagnosis of Morgagni's hernia.