Communicating Radiation Risk to the Population of Fukushima

Radiological specialists from Nagasaki University have served on the medical relief team organized at Fukushima Medical University Hospital (Fukushima City) ever since the accident at the Fukushima Dai-ichi nuclear power plant. Furthermore, we have conducted the radiation crisis communication efforts by spreading correct information on the health effects of radiation as 'advisors on radiation health risk control'. Nagasaki University has been assisting the reconstruction efforts of Kawauchi Village in Fukushima Prefecture, which was the first village to declare that residents could safely return to their homes because radiation doses were found to be at comparatively low levels. In April 2013, Nagasaki University and the Kawauchi government office concluded an agreement concerning comprehensive cooperation toward reconstruction of the village. As a result, we established a satellite facility of the university in the village. In conclusion, training of specialists who can take responsibility for long-term risk communication regarding the health effects of radiation as well as crisis communication in the initial phase of the accident is an essential component of all such recovery efforts. Establishment of a training system for such specialists will be very important both for Japan and other countries worldwide.

Computational insights into binding of bisphosphates to farnesyl pyrophosphate synthase

Bisphosphonates (BPs) are the most widely used and effective treatment for osteoporosis and Paget's disease. Non-nitrogen containing BPs (non-N-BPs), namely etidronate, clodronate, tiludronate, as well as nitrogen-containing BPs (N-BPs), namely pamidronate, alendronate, ibandronate, risedronate, zoledronate and minodronate have been launched on the market to date. N-BPs act by inhibiting the enzyme farnesyl pyrophosphate synthase (FPPS), and several crystal structures of complexes between FPPS and N-BPs have been revealed. Understanding the physical basis of the binding between protein and small molecules is an important goal in both medicinal chemistry and structural biology. In this review, we analyze in detail the energetic basis of molecular recognition between FPPS and N-BPs. First, we summarize the interactions between ligands and proteins observed in N-BPs-FPPS complexes in the Protein Data Bank (PDB). Second, we present an interaction energy analysis on the basis of full quantum mechanical calculation of FPPS and N-BP complexes using the fragment molecular orbital (FMO) method. The FMO result revealed that not only hydrogen bond and electrostatic interaction but also CH-O and π-π interaction with FPPS are important for N-BP’s potency. Third, we describe a binding site analysis of FPPS on the basis of the inhomogeneous solvation theory which, by clustering the results from an explicit solvent molecular dynamics simulation (MD), is capable of describing the entropic and enthalpic contributions to the free energies of individual hydration sites. Finally, we also discuss the structure-activity relationship (SAR) of the series of minodronate derivatives.

Hematological alterations in the Otsuka Long-Evans Tokushima fatty (OLETF) rats--a model of type 2 diabetes mellitus

The OLETF rat develops microangiopathic complications similar to human diabetes and is considered a useful model of Type 2 DM. Erythrocyte, platelet and leucocyte abnormalities described in diabetic patients are thought to play a role in the development of diabetic microangiopathy. This study was designed to investigate whether OLETF rats show hematological alterations and the effect of sucrose treatment on metabolic and blood parameters. Hematological parameters, body weight, food and water intake, fasting and non-fasting blood glucose (BG) and HbA1c were measured in OLETF rats treated for two months with 30% sucrose added to drinking water. Non-treated OLETF rats and non-diabetic Long-Evans Tokushima Otsuka (LETO) rats were used as controls. In the control OLETF rats the number of platelets (Plt) and red blood cells (RBC) was higher, while the mean cell volume (MCV) and the mean cell hemoglobin content (MCH) were lower compared with LETO. Mean cell hemoglobin concentration (MCHC) was significantly higher in the diabetic rats. Sucrose administration decreased food intake and body weight and increased fasting blood glucose and HbA1c. It resulted in a decrease of RBC, Hb, Hct, MCV and MCH compared with control OLETF, while Plt count increased significantly. Our results point to significant alterations in erythrocyte count and morphology and Plt count in diabetic OLETF rats compared with non-diabetic LETO. Sucrose administration accelerated the development of diabetes, affected blood cells inducing the suppression of RBC and an increase in Plt count and some of its effects persisted after sucrose withdrawal.

Design and synthesis of non-peptidic inhibitors for the Syk C-terminal SH2 domain based on structure-based in-silico screening

Structure-based in-silico screening was carried out for the Syk C-terminal SH2 domain. Fragments that could interact with the pY or pY+1 pockets were selected by our in-silico screening. After tethering two fragments bound to these pockets, we have designed and synthesized new compounds that show favorable interaction with the pY+3 pocket. One such compound, having a cyclohexylmalonic acid moiety identified as a novel potent phosphotyrosyl mimetic, exhibited an affinity comparable to that of the monophosphorylated ligand peptide.

Ethenesulfonamide and ethanesulfonamide derivatives, a novel class of orally active endothelin-A receptor antagonists

In the previous paper, we described a series of 2-phenylethenesulfonamide derivatives, a novel class of ET(A)-selective endothelin (ET) receptor antagonists, including the 2-methoxyethoxy derivative 2a and the 2-fluoroethoxy derivative (2b). In this paper, we wish to report further details of structure-activity relationships (SARs) of the two regions of the molecule in compound 2b, which were the alkoxy region at the 6-position of the core pyrimidine ring and the 2-phenylethenesulfonamide region. In these modifications, replacement of the 2-fluoroethoxy group with a methoxy group (6e) and replacement of the 2-phenylethenesulfonamide group with a 2-(pyridin-3-yl)ethenesulfonamide group (6l) or 2-phenylethanesulfonamide group (6q) were well tolerated both in the ET(A) binding affinity and ET(A) selectivity. Among them, compound 6e showed further improvement in oral activity compared to 2b. After oral administration, compound 6e inhibited the big ET-1 induced pressor response in conscious rats at 0.3mg /kg with a duration of >6.5h. Compound 6e also exhibited a potent antagonistic activity in the pithed rats.

Coumarin and chromen-4-one analogues as tautomerase inhibitors of macrophage migration inhibitory factor: discovery and X-ray crystallography

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine released from T-cells and macrophages. Although a detailed understanding of the biological functions of MIF has not yet been clarified, it is known that MIF catalyzes the tautomerization of a nonphysiological molecule, D-dopachrome. Using a structure-based computer-assisted search of two databases of commercially available compounds, we have found 14 novel tautomerase inhibitors of MIF whose K(i) values are in the range of 0.038-7.4 microM. We also have determined the crystal structure of MIF complexed with the hit compound 1. It showed that the hit compound is located in the active site of MIF containing the N-terminal proline which plays an important role in the tautomerase reaction and forms several hydrogen bonds and undergoes hydrophobic interactions. A crystallographic study also revealed that there is a hydrophobic surface which consists of Pro-33, Tyr-36, Trp-108, and Phe-113 at the rim of the active site of MIF, and molecular modeling studies indicated that several more potent hit compounds have the aromatic rings which can interact with this hydrophobic surface. To our knowledge, our compounds are the most potent tautomerase inhibitors of MIF. One of these small, drug-like molecules has been cocrystallized with MIF and binds to the active site for tautomerase activity. Molecular modeling also suggests that the other hit compounds can bind in a similar fashion.

Inhibitory effects of 1,4-naphthoquinone derivatives on rat cytochrome P4501A1-dependent monooxygenase activity in recombinant yeast microsomes

We reported previously that various naphthoquinone derivatives inhibited cytochrome P450-dependent monooxygenase of liver and placenta microsomes [Muto, N. et al. (1987) Biochem. Biophys. Res. Commun. 146, 487-494]. To understand the complex inhibitory behaviors that were observed, it is desirable to study the relationship between structure and inhibitory activity of naphthoquinones in a simplified system containing a single P450 species. In the present study, the inhibitory effects of six derivatives of 1,4-naphthoquinone (hereafter referred to as NQ) on rat cytochrome P4501A1-dependent 7-ethoxycoumarin O-deethylation were examined using yeast microsomes containing overexpressed rat P4501A1. Of these, 2-methyl-5-hydroxy-NQ, 2-methyl-NQ, 2-hydroxy-NQ, and NQ showed competitive inhibition, whereas 5,8-dihydroxy-NQ and 5-hydroxy-NQ showed noncompetitive inhibition. Judging from the inhibitor constant (K(i)), the binding affinity of the four competitive inhibitors for the substrate-binding pocket of P4501A1 is in the order: 2-CH(3)-5-OH-NQ > 2-CH(3)-NQ > NQ >> 2-OH-NQ. On binding with P4501A1, 2-CH(3)-5-OH-NQ, 2-CH(3)-NQ, and NQ induced distinct Type II, Type I, and reverse Type I spectra, respectively. These results indicate that methyl and hydroxyl groups introduced into NQ have unique effects on their binding mode and binding affinity.

Significant change in the structure of a ribozyme upon introduction of a phosphorothioate linkage at P9: NMR reveals a conformational fluctuation in the core region of a hammerhead ribozyme

A modified hammerhead ribozyme (R32S) with a phosphorothioate linkage between G(8) and A(9), a site that is considered to play a crucial role in catalysis, was examined by high-resolution 1H and (31)P nuclear magnetic resonance (NMR) spectroscopy. Signals due to imino protons that corresponded to stems were observed, but the anticipated signals due to imino protons adjacent to the phosphorothioate linkage were not detected and the (31)P signal due to the phosphorothioate linkage was also absent irrespective of the presence or absence of the substrate. (31)P NMR is known to reflect backbone mobility, and thus the absence of signals indicated that the introduction of sulfur at P9 had increased the mobility of the backbone near the phosphorothioate linkage. The addition of metal ions did not regenerate the signals that had disappeared, a result that implied that the structure of the core region of the hammerhead ribozyme had fluctuated even in the presence of metal ions. Furthermore, kinetic analysis suggested that most of the R32S-substrate complexes generated in the absence of Mg(2+) ions were still in an inactive form and that Mg(2+) ions induced a further conformational change that converted such complexes to an activated state. Finally, according to available NMR studies, signals due to the imino protons of the central core region that includes the P9 metal binding site were broadened or not observed, suggesting that this catalytically important region might be intrinsically flexible. Our present analysis revealed a significant change in the structure of the ribozyme upon the introduction of the single phosphorothioate linkage at P9 that is in general considered to be a conservative modification.

A novel target recognition revealed by calmodulin in complex with Ca2+-calmodulin-dependent kinase kinase

The structure of calcium-bound calmodulin (Ca2+/CaM) complexed with a 26-residue peptide, corresponding to the CaM-binding domain of rat Ca2+/CaM-dependent protein kinase kinase (CaMKK), has been determined by NMR spectroscopy. In this complex, the CaMKK peptide forms a fold comprising an alpha-helix and a hairpin-like loop whose C-terminus folds back on itself. The binding orientation of this CaMKK peptide by the two CaM domains is opposite to that observed in all other CaM-target complexes determined so far. The N- and C-terminal hydrophobic pockets of Ca2+/CaM anchor Trp 444 and Phe 459 of the CaMKK peptide, respectively. This 14-residue separation between two key hydrophobic groups is also unique among previously determined CaM complexes. The present structure represents a new and distinct class of Ca2+/CaM target recognition that may be shared by other Ca2+/CaM-stimulated proteins.

A case of MALT (mucosa-associated lymphoid tissue) lymphoma occurring in the rectum

A case of mucosa-associated lymphoid tissue (MALT) lymphoma of the rectum is reported. A 64 year-old woman was referred to us for the evaluation of occult blood in the stool. A hard mass was palpable on digital examination. Biopsy specimens revealed a histologic picture compatible with MALT lymphoma. Abdominoperineal excision of the rectum was carried out. Chemotherapy was not performed, and the post-operative course was uneventful, with no evidence of recurrence for 2 years and 11 months. Surgical resection is an effective therapy for MALT lymphoma of the rectum.

Formation of a catalytically active dimer by tRNA(Val)-driven short ribozymes

A minizyme is a hammerhead ribozyme with a short oligonucleotide linker instead of stem/loop II. Minizymes with low activity as monomers form active dimeric structures with a common stem. We explored the use of dimeric minizymes as gene-inactivating agents by placing minizymes under the control of a tRNA(Val) promoter. The tRNA(Val) portion of the transcript did not hinder dimerization as the tRNA-embedded minizyme formed an active dimeric structure. The cleavage activity of this minizyme that had been expressed either in vitro or in HeLa cells was almost one order of magnitude higher than that of the tRNA(Val)-embedded conventional hammerhead ribozyme. The tRNA(Val)-driven minizyme inhibited reporter gene activity (95%) whereas the tRNA(Val)-driven hammerhead ribozyme resulted in approximately 55% inhibition.

Spiro-substituted piperidines as neurokinin receptor antagonists. III. Synthesis of (+/-)-N-[2-(3,4-dichlorophenyl)-4-(spiro-substituted piperidin-1'-yl)butyl]-N-methylbenzamides and evaluation of NK1-NK2 dual antagonistic activities

To discover a novel NK1-NK2 dual antagonist, we have synthesized a series of spiro-substituted piperidines utilizing YM-35375 as a lead compound, and evaluated affinities for NK1 and NK2 receptors. In the N-methylbenzamide moiety, introduction of methoxy groups increased affinity for the NK1 receptor without a significant loss of affinity for the NK2 receptor. We also found that a conformation in which the phenyl groups of the N-methylbenzamide and 3,4-dichlorophenyl moieties are close to each other through a cis-amide bond, may be favorable for showing high affinity for the NK1 receptor and that a hydrogen bond-accepting group in the spiro-substituted piperidine moiety may be crucial for exhibiting high affinity for the NK2 receptor. Among the compounds prepared, YM-44778 (31) showed high and well-balanced affinity for NK1 and NK2 receptors (IC50 values of 18 and 16 nM, respectively). This compound also exhibited potent antagonistic activities against both NK1 and NK2 receptors (IC50 values of 82 and 62 nM, respectively) in isolated tissues.

Laparoscopic repair of a diaphragmatic hernia through the foramen of morgagni

A 78-year-old woman is described who presented with a diaphragmatic hernia through the foramen of Morgagni. A definitive diagnosis was confirmed by a sagittal view on magnetic resonance imaging prior to surgery. The hernia was repaired laparoscopically under an abdominal wall lifting technique without pneumoperitoneum, and her symptoms completely resolved postoperatively with no evidence of recurrence. The laparoscopic repair was considered a suitable and safe procedure for the treatment of a Morgagni hernia.

A quinine-activated cationic conductance in vertebrate taste receptor cells

The chincona alkaloid quinine is known to be a bitter tasting substance for various vertebrates. We examined the effects of quinine on isolated taste receptor cells from the bullfrog (Rana catesbeiana). Membrane currents were recorded by whole-cell recording, while quinine hydrochloride was applied extracellularly from a puffer pipette. At the resting potential (-77 +/- 9 mV, mean +/- SD, n = 49 cells), taste cells generated inward currents in response to quinine stimulation (> 1 mM), indicating a depolarizing response in the taste cells. Two types of current responses were observed; a newly found quinine-activated cationic conductance and a previously reported blocking effect of quinine on K+ conductances. The cationic current was isolated from the K+ current by using a Cs(+)-containing patch pipette. The relative permeabilities (Pion) of the quinine-activated cationic conductance were: PNa/PK/PCs = 1:0.5:0.42. The quinine dose-response relation was described by the Hill equation with the K1/2 of 3.6 mM and Hill coefficient of 5.3. When extracellular [Ca2+] (1.8 mM) was reduced to nominally free, the conductance was enhanced by about sixfold. This property is consistent with observations on quinine responses recorded from the gustatory nerve, in vivo. The quinine-induced cationic current was decreased with an application of 8-bromo-cAMP. We conclude that the bitter substance quinine activates a cation channel in taste receptor cells and this channel plays an important role in bitter taste transduction.

Effects of YM-51084 and YM-51085, new inhibitors produced by Streptomyces sp. Q21705, on cathepsin L

The structures of YM-51084 and YM-51085, new protease inhibitors produced by Streptomyces sp. Q21705, were determined by 1H- and 13C-NMR and mass spectrometry. Both were characterized by the basic structures of an acyl-tripeptide. YM-51084 was elucidated to be isovaleryl-tyrosyl-valyl-phenylalaninal and YM-51085 was the reduced phenylalaninol form of YM-51084. These compounds proved to strongly inhibit human kidney cathepsin L; the IC50 values being 9.6 x 10(-9) M and 3.5 x 10(-7) M, respectively.

Magnesium-mediated conversion of an inactive form of a hammerhead ribozyme to an active complex with its substrate. An investigation by NMR spectroscopy

The effects of magnesium ions on a 32-mer ribozyme (R32) were examined by high resolution NMR spectroscopy. In solution, R32 (without its substrate) consisted of a GAAA loop, stem II, a non-Watson-Crick 3-base pair duplex and a 4-base pair duplex that included a wobble G:U base pair. When an uncleavable substrate RNA (RdC11) was added to R32 without Mg2+ ions, a complex did not form between R32 and RdC11 because the substrate recognition regions of R32 formed intramolecular base pairs (the recognition arms were closed). By contrast, in the presence of Mg2+ ions, the R32-RdC11 complex was formed. Moreover, titration of mixtures of R32 and RdC11 with Mg2+ ions also induced the ribozyme-substrate interaction. Elevated concentrations (1.0 M) of monovalent Na+ ions could not induce the formation of the R32-RdC11 complex. These data suggest that Mg2+ ions are not only important as the true catalysts in the function of ribozyme-type metalloenzymes, but they also induce the structural change in the R32 hammerhead ribozyme that is necessary for establishment of the active form of the ribozyme-substrate complex.

High-resolution NMR study of a GdAGA tetranucleotide loop that is an improved substrate for ricin, a cytotoxic plant protein

Ricin is a cytotoxic plant protein that inactivates ribosomes by hydrolyzing the N-glycosidic bond at position A4324 in eukaryotic 28S rRNA. Recent studies showed that a four-nucleotide loop, GAGA, can function as a minimum substrate for ricin (the first adenosine corresponds to the site of depurination). We previously clarified the solution structure of this loop by NMR spectroscopy [Orita et al. (1993) Nucleic Acids Res. 21, 5670-5678]. To elucidate further details of the structural basis for recognition of its substrate by ricin, we studied the properties of a synthetic dodecanucleotide, r1C2U3C4A5G6dA7G8A9U10G11A12G (6dA12mer), which forms an RNA hairpin structure with a GdAGA loop and in which the site of depurination is changed from adenosine to 2'-deoxyadenosine. The N-glycosidase activity against the GdAGA loop of the A-chain of ricin was 26 times higher than that against the GAGA loop. NMR studies indicated that the overall structure of the GdAGA loop was similar to that of the GAGA loop with the exception of the sugar puckers of 6dA and 7G. Therefore, it appears that the 2'-hydroxyl group of adenosine at the depurination site (6A) does not participate in the recognition by ricin of the substrate. Since the 2'-hydroxyl group can potentially destabilize the developing positive charge of the putative transition state intermediate, an oxycarbonium ion, the electronic effect may explain, at least in part, the faster rate of depurination of the GdAGA loop compared to that of GAGA loop. We also show that the amino group of 7G is essential for substrate recognition the ricin A-chain.

Kalimantacin A, B, and C, novel antibiotics produced by Alcaligenes sp. YL-02632S. II. Physico-chemical properties and structure elucidation

Kalimantacin A, B and C are new antibiotics produced by Alcaligenes sp. YL-02632S. Their structures were elucidated to be novel long chain structure compounds containing O-carbamoyl, amide and carboxylic acid moieties based on various 2D NMR experiments and MS analysis.

YM-47141 and YM-47142, new elastase inhibitors produced by Flexibacter sp. Q17897. II. Structure elucidation

YM-47141 and YM-47142 are new elastase inhibitor produced by Flexibacter sp. Q17897. These structures were elucidated by MS and NMR spectral analysis. YM-47141 and YM-47142 were the cyclic peptides containing tricarbonyl moiety hydrated on the center carbonyl carbon in DMSO-d6.

YM-47141 and 47142, new elastase inhibitors produced by Flexibacter sp. Q17897. I. Taxonomy, fermentation, isolation, physico-chemical properties and biological activities

In the course of our screening for elastase inhibitors from microorganism, we have found two new cyclic-depsipeptides designated YM-47141 and 47142. In this paper, we described the taxonomy of the producing organism and isolation, physico-chemical properties, and biological activities of YM-47141 and 47142.

Effects of glycyrrhetinic acid on aminonucleoside nephrosis in rats

The effects of glycyrrhetinic acid (GA), an aglycon of glycyrrhizin extracted from the roots of Glycyrrhizae radix, on puromycin aminonucleoside (PA) nephrosis were studied in rats. Urine protein excretion in female rats (130 g-150 g) receiving PA (50 mg/kg) alone was significantly elevated on the 2nd day after injection of PA and reached a peak on the 14th day. Urinary protein on the 14th day was reduced to 74% in animals treated with GA (20 mg/kg) starting on the 2nd day after injection of PA. The increase in serum cholesterol and the decrease in serum protein were also suppressed by GA. Observation by electron microscopy revealed that the degree of abnormality in glomerular epithelial cells, i.e. loss or fusion of foot processes, was lower in the rats treated with GA after PA injection than in the rat treated with PA alone. Moreover, pretreatment with GA did not suppress urinary protein excretion but when it was given at the same time as PA and after PA a significant decrease in urinary protein excretion was observed.

High-resolution NMR study of a synthetic oligoribonucleotide with a tetranucleotide GAGA loop that is a substrate for the cytotoxic protein, ricin

Ricin is a cytotoxic protein that inactivates ribosomes by hydrolyzing the N-glycosidic bond at position A4324 in eukaryotic 28S rRNA. Its substrate domain forms a double helical stem and a 17-base loop that includes the sequence GAGA, the second adenosine of which corresponds to A4324. Recently, studies of mutant RNAs have shown that the four-nucleotide loop, GAGA, can function as a substrate for ricin. To investigate the structure that is recognized by ricin, we studied the properties of a short synthetic substrate, the dodecaribonucleotide r-CUCAGAGAUGAG, which forms a RNA hairpin structure with a GABA loop and a stem of four base pairs. The results of NMR spectroscopy allowed us to construct the solution structure of this oligonucleotide by restrained molecular-dynamic calculations. We found that the stem region exists as an A-form duplex. 5G and 8A in the loop region form an unusual G:A base pair, and the phosphodiester backbone has a turn between 5G and 6A. This turn seems to help ricin to gain access to 6A which is the only site of depurination in the entire structure. The overall structure of the GAGA loop is similar to those of the GAAA and GCAA loops that have been described but that are not recognized by ricin. Therefore, in addition to the adenosine at the depurination site, the neighboring guanosine on the 3' side (7G) may also play a role in the recognition mechanism together with 5G and 8A.

Resistance to ketosis in moderately obese patients: influence of fatty liver

To elucidate whether the presence of fatty liver influences ketogenesis in obesity, the metabolic and hormonal changes in basal and low-dose epinephrine (EPI)-stimulated states were studied in 12 obese patients (OB) with normal glucose tolerance, consisting of 6 without fatty liver (OBN) and 6 with fatty liver (OBF). In the basal state, the total ketone body (TKB) concentration and the TKB to free fatty acid (FFA) ratio were significantly (p < 0.01) lower in the OBF than in the OBN group, despite elevated, but comparable, FFA levels in both groups. The basal FFA level and the TKB/FFA ratio correlated with the degree of fatty liver (p < 0.05-0.01). EPI infusion resulted in accelerated lipolysis and diminished FFA-induced ketogenesis, similar to the findings of the basal data. These results suggest that fatty liver per se is related to diminished FFA-induced ketogenesis, leading to resistance to ketosis in obesity.

Effects of calcium antagonists on the erythrocyte membrane

The effects of dihydropyridine compounds nimodipine, nicardipine and NB818 (isopropyl methyl-6-carbamoyloxymethyl-4-(2,3-dichlorophenyl)-1,4-dihydro-2-methyl- 3,5- pyridine-dicarboxylate) on erythrocyte membranes have been studied. These compounds showed protective effects against hypotonic haemolysis, but not against heat-induced haemolysis. An increase in deformability of erythrocytes by these calcium antagonists was observed using a capillary tube centrifugal method. The erythrocytes showed slight stomatocytosis after 30 min of incubation with calcium antagonists, but did not show significant changes in mean corpuscular volume and ATP levels.

DNA sequence polymorphisms in Alu repeats

We have developed an efficient method for detection of sequence differences in genomic DNA based on a new principle (M. Orita et al., 1989, Genomics 5: 874-879). Using this method, we show here that approximately half the Alu repeats interspersed in the human genome are significantly polymorphic. Analysis of Alu repeat polymorphism should be useful in construction of a high-resolution map and also in identifying genotypes of individuals for clinical and other purposes because the repeats are ubiquitous and the technique for their detection is simple.

Detection of ras gene mutations in human lung cancers by single-strand conformation polymorphism analysis of polymerase chain reaction products

A simple, sensitive method of DNA analysis of nucleotide substitutions, namely, single-strand conformation polymorphism analysis of polymerase chain reaction products (PCR-SSCP analysis), was used for detection of mutated ras genes in surgical specimens of human lung cancer. Of a total of 129 tumors analysed, 22 contained a mutated ras gene. Of the 66 adenocarcinomas analysed, 14 contained an activated c-Ki-ras2 gene (the mutations in codon 12 in 6, in codon 13 in 4, in codon 18 in one, and in codon 61 in 3), one contained a c-Ha-ras1 gene with a mutation in codon 61 and 3 contained N-ras genes with mutations (in codon 12 in one and in codon 61 in 2). Mutated rats genes were also found in 2 of 36 squamous cell carcinomas (c-Ha-ras1 genes with mutations in codon 61) and 2 of 14 large cell carcinomas (c-Ki-ras2 genes with mutations in codon 12). No mutation of the ras gene was detected in 8 small cell carcinomas and 5 adenosquamous cell carcinomas. These results indicate that activation of the ras gene was not frequent (17%) in human lung cancers, that among these lung cancers mutation of the ras gene was most frequent in adenocarcinomas (27%) and 73% of the point mutations were in the c-Ki-ras2 gene in codon 12, 13, 18 or 61.

A new RFLP in intron 1 of the human c-Ha-ras1 gene and its close relationship with the variable tandem repeats in the region 3' to the gene

Based on restriction fragment length polymorphism (RFLP) analysis of BamHI or MspI fragments, the human c-Ha-ras1 alleles could be divided into two major groups, one having about 80 copies of a 28 base pair (bp) sequence in the variable tandem repeat (VTR) region 1.4-kilobase pairs (kb) downstream from the end of the coding exon and the other having 40 copies of the sequence. We found a second RFLP in intron 1 of the c-Ha-ras1 gene at a position about 80 bp upstream from the 5'-end of exon 1. The size of the PstI fragments carrying this region is either 371 or 359 bp depending on the numbers of a hexanucleotide sequence, GGGCCT. In larger fragments, the unit sequence was repeated four times, while in smaller fragments it was repeated twice. Unexpectedly, we found that the alleles with 80 copies of the 28 bp sequence in the VTR region all carried two repeats of GGGCCT in intron 1, while alleles with 40 copies all had four repeats of the GGGCCT sequence.

Age-related changes of erythrocyte membrane in the senescence-accelerated mouse

Age-related changes in erythrocytes in senescence-accelerated mice (SAM-P) and control mice with normal aging characteristics (SAM-R) were examined. A significant decrease in the number of erythrocytes and significant increases in MCV and ATP levels were observed with aging in SAM-P, while no significant changes were seen in SAM-R. Erythrocytes in aged SAM-P were less fragile than those in aged SAM-R. The contents of cholesterol and phospholipids in erythrocyte membranes increased significantly in aged SAM-P, but the molar ratio of cholesterol/phospholipid decreased. The plasma cholesterol level of SAM-P decreased with aging. Changes such as those observed in SAM-P were not seen in SAM-R during the period of observation.

Rapid and sensitive detection of point mutations and DNA polymorphisms using the polymerase chain reaction

We report a rapid and sensitive method for the detection of base changes in given sequences of genomic DNA. This technique is based on the facts that specific regions of genomic sequences can be efficently labeled and amplified simultaneously by using labeled substrates in the polymerase chain reaction and that in nondenaturing polyacrylamide gels, the electrophoretic mobility of single-stranded nucleic acid depends not only on its size but also on its sequence. The process does not involve restriction enzyme digestion, blotting, or hybridization to probes. We found that most single base changes in up to 200-base fragments could be detected as mobility shifts. RAS oncogene activation was detected by this technique. We also show that the interspersed repetitive sequences of human, Alu repeats are highly polymorphic.

Use of labeled primers in polymerase chain reaction (LP-PCR) for a rapid detection of the product

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Loss of heterozygosity at polymorphic chromosomal loci in patients with malignant melanoma

One type of aberration of DNA found in human cancers is loss of heterozygosity at chromosomal loci. This loss suggests that inactivation of particular genes is involved in the genesis of cancer cells. We have analyzed tumor DNA and normal DNA from eight patients with malignant melanomas using 24 polymorphic DNA probes and detected loss of heterozygosity in three patients at five loci on four different chromosomes. These results indicate that the frequency of loss of heterozygosity at chromosomal loci is relatively high in malignant melanomas, but that the regions lost are not restricted to specific chromosomes.

Elevated pancreatic glucagon in moderately obese patients: relationship of fatty liver and hypertriglyceridemia

To elucidate if the presence of fatty liver and hypertriglyceridemia (HTG) influences pancreatic A-cell function in obesity, basal and arginine-stimulated glucagon (IRG) secretions were studied in 7 normal subjects and in 28 moderately obese patients (OB) with normal glucose tolerance. The patients were divided into 4 groups, based on the presence of fatty liver and/or HTG. BMI was similar in all four obese groups. Basal IRG, as well as the sum of secretory response to arginine, namely sigma IRG values, were significantly (p less than 0.01) higher in the OB subgroup having both fatty liver and HTG than in the other three groups; these values were similar in subgroups of OB without fatty liver, and showed no significant difference from the normals. Basal and sigma IRG values in all OB correlated well with the degree of fatty liver and HTG, demonstrating that by stepwise analysis the effects of fatty liver and HTG were independent for basal and sigma IRG values. These results suggest that the combination of fatty liver and HTG may serve as a good predictor of hyperglucagonemia in simple obesity, and, hence, metabolic heterogeneity among obese patients should be considered in evaluating A-cell function.

Detection of polymorphisms of human DNA by gel electrophoresis as single-strand conformation polymorphisms

We developed mobility shift analysis of single-stranded DNAs on neutral polyacrylamide gel electrophoresis to detect DNA polymorphisms. This method follows digestion of genomic DNA with restriction endonucleases, denaturation in alkaline solution, and electrophoresis on a neutral polyacrylamide gel. After transfer to a nylon membrane, the mobility shift due to a nucleotide substitution of a single-stranded DNA fragment could be detected by hybridization with a nick-translated DNA fragment or more clearly with RNA copies synthesized on each strand of the DNA fragment as probes. As the mobility shift caused by nucleotide substitutions might be due to a conformational change of single-stranded DNAs, we designate the features of single-stranded DNAs as single-strand conformation polymorphisms (SSCPs). Like restriction fragment length polymorphisms (RFLPs), SSCPs were found to be allelic variants of true Mendelian traits, and therefore they should be useful genetic markers. Moreover, SSCP analysis has the advantage over RFLP analysis that it can detect DNA polymorphisms and point mutations at a variety of positions in DNA fragments. Since DNA polymorphisms have been estimated to occur every few hundred nucleotides in the human genome, SSCPs may provide many genetic markers.

Altered basal C-peptide/insulin molar ratios in obese patients with fatty liver

To elucidate if the presence of fatty liver in obesity influences hepatic insulin extraction under basal conditions, serum immunoreactive insulin (IRI) and C-peptide immunoreactivity (CPR) were measured in 20 obese patients with normal glucose tolerance and in 8 normal subjects. The obese patients were subdivided into two groups matched for age and body weight according to the presence or absence of fatty liver: 8 obese patients without fatty liver (OBN) and 14 with fatty liver (OBF). Basal levels of IRI and CPR were significantly greater in the obese patients than in the normals, but were similar in the two obese groups. In the OBF group, the CPR/IRI molar ratios, a relative measure of hepatic insulin uptake, were significantly lower than in the other two groups, while the ratios of the normal and OBN groups were similar. The CPR/IRI molar ratios in all obese patients correlated well with the degree of fatty liver (r = 0.785, p less than 0.001). These results suggest that hepatic insulin extraction in a subgroup of obese patients is either reduced or indistinguishable from that of non-obese subjects, and that basal CPR/IRI molar ratio may serve as a useful indicator of the presence of fatty liver in simple obesity.

Effects of ultraviolet irradiation on surface marker expression by epidermal immunocompetent cells and contact sensitization to dinitrofluorobenzene in mice

We studied the effects of ultraviolet (UV) irradiation on murine epidermal Ia-positive Langerhans cells (Ia + LC) and Thy-I-positive dendritic epidermal cells (Thy-I + dEC). We also studied contact hypersensitivity to dinitrofluorobenzene (DNFB) introduced through UV-treated epidermis. C3H/HeN mice were exposed to UVB or 8-methoxypsoralen plus UVA (PUVA). UVB and PUVA treatment led to a dramatic reduction in surface marker expression of both Ia + LC and Thy-I + dEC. High-dose UVB irradiation (360 J/m2) interfered with contact hypersensitivity to DNFB; the density of Ia + LC may thus be related to the sensitizing potential. In contrast, low-dose UVB (120 J/m2) and PUVA treatment had little effect on contact hypersensitivity despite a marked reduction in Ia + LC. The density of Thy-I + dEC appeared not to be associated with contact hypersensitivity. These results suggest that there may be a Langerhans cell density-independent mechanism for the induction of contact hypersensitivity.

Concurrent multiple morphea and neonatal lupus erythematosus in an infant boy born to a mother with SLE

An infant boy born to a mother with systemic lupus erythematosus developed multiple morphea and annular erythematous lesions. The annular lesions appeared on his face, back, chest and extremities one month after birth and faded within 7 months. The sclerotic lesions progressed until the age of 6 months and remain on his back, chest, right cheek, the nape of the neck and left shoulder at the age of 3 years. Histological findings in the sclerotic lesions were consistent with scleroderma. Serological tests, performed at 14 months of age, were within normal limits. The mother developed acute SLE and died of cardio-renal failure 8 months after the delivery. It is highly probable that maternal factors transferred through the placenta caused the sclerotic lesions in the infant.

Effects of saikosaponin-d on aminonucleoside nephrosis in rats

The effects of saikosaponin-d extracted from the roots of Bupleurum falcatum L. on aminonucleoside nephrosis were studied in rats. Urine protein excretion in rats receiving aminonucleoside alone was significantly elevated on the 2nd day after the last injection of aminonucleoside and reached a peak on the 11th day. Urinary protein on the 11th day was reduced by 48 and 46%, respectively in animals treated with saikosaponin-d from the 2nd and 8th day after the last injection of aminonucleoside. Electron microscopically, the degree of abnormality, e.g. loss or fusion of foot processes, in the glomerular epitherial cells was significantly lower in the rats treated with saikosaponin-d after aminonucleoside injection than in the rats treated with aminonucleoside alone. It is concluded that saikosaponin-d prevents the development of proteinuria induced by aminonucleoside in the rat.

Multiple agminate juvenile melanoma

A multiple agminate juvenile melanoma of the right ear lobe occurred in a 46-year-old man.

Effects of saikosaponin-d on enhanced CCl4-hepatotoxicity by phenobarbitone

The effects of saikosaponin-d extracted from the roots of Buplerum falcatum L. on increased toxicity of CCl4 and increased activities of microsomal enzymes induced by phenobarbitone have been examined. Saikosaponin-d showed protection against the CCl4-hepatotoxicity enhanced by phenobarbitone. It also inhibited increases in the content of cytochrome P450 and NADPH-cytochrome c reductase activity, which are induced by the phenobarbitone treatment, but the spectral characteristics of P450 were not altered. The rate of microsomal lipid peroxidation by NADPH and CCl4 was significantly lowered in-vitro in rats pretreated with phenobarbitone and saikosaponin-d compared with those pretreated with phenobarbitone alone.

Effects of saikosaponin-d on enhanced CCl4-hepatotoxicity by phenobarbitone

The effects of saikosaponin-d extracted from the roots of Buplerum falcatum L. on increased toxicity of CCl4 and increased activities of microsomal enzymes induced by phenobarbitone have been examined. Saikosaponin-d showed protection against the CCl4-hepatotoxicity enhanced by phenobarbitone. It also inhibited increases in the content of cytochrome P450 and NADPH-cytochrome c reductase activity, which are induced by the phenobarbitone treatment, but the spectral characteristics of P450 were not altered. The rate of microsomal lipid peroxidation by NADPH and CCl4 was significantly lowered in-vitro in rats pretreated with phenobarbitone and saikosaponin-d compared with those pretreated with phenobarbitone alone.

Erythrocyte deformability in aging

Blood viscosity and the deformability and other properties of erythrocytes were compared among 60-, 150-, 320- and 710-day-old rats. Blood viscosity was remarkably higher in the 320- and 710-day old rats than in those 60- and 150 days' old. Measurement by the capillary centrifugal method showed that the deformability of erythrocytes is significantly decreased with age. The increase in blood viscosity with aging could be attributed to the decrease in erythrocyte deformation. Osmotic fragility and the number of higher density erythrocytes also increase with age. The negative surface charge in erythrocytes obtained from old rats was higher than in those from younger rats.