Effect of modification of the carboxyl groups of the sialic acid binding lectin from bullfrog (Rana catesbeiana) oocyte on anti-tumor activity

The sialic acid binding lectin from bullfrog Rana catesbeiana oocyte (cSBL) is known to have anti-tumor activity. In order to investigate the relationship between the net charge of cSBL and its anti-tumor effect, cSBL was modified with a water-soluble carbodiimide (EDC) in the presence of three kinds of nucleophiles, taurine, glycine methylester and ethylenediamine. cSBL having four carboxyl groups was partially modified (ca. 2 residues). The anti-tumor activity of modified cSBLs was in the order of ethylenediamine-modified cSBL > glycine methylester-modified cSBL > taurine modified cSBL > or = native cSBL. The results suggested that anti-tumor activity seems to increase with the increase in positive net charge, possibly enhancing the interaction of cSBL with sialoglycoprotein on the surface of tumor cells. The ribonuclease activity of ethylenediamine-modified cSBL decreased with the progress of the reaction, but the number of internalized molecules in the tumor cell increased. Thus, for antitumor activity, a higher incorporation of cSBL with reasonable RNase activity seems to be more important than total RNase activity.

Photochromism of diarylethenes with two nitronyl nitroxides: photoswitching of an intramolecular magnetic interaction

Photochromic diarylethenes that have p-phenylene-substituted benzothiophene aryl groups with and without nitronyl nitroxide radicals at both ends of the molecules were synthesized. The absorption maxima of the closed-ring isomers showed a hypsochromic shift with the increase in the pi-conjugated chain length. The unique behavior was attributed to the stabilization by the resonant quinoid structures. Both photocyclization and photocycloreversion quantum yields of the diarylethene with nitronyl nitroxide radicals were found to increase with the increase in the pi-conjugated chain length. Photoswitching of the magnetic interaction between two nitronyl nitroxide radicals was studied by means of ESR spectroscopy. The change in exchange interaction between open- and closed-ring isomers of 1,2-bis[6-[4-[4-(1-oxyl-3-oxide-4,4,5,5-tetramethylimidazolin-2-yl)phenyl]phenyl]-2-methyl-1-benzothiophen-3-yl]hexafluorocyclopentene was determined to be more than 30-fold.

Synthesis and photoisomerization of dithienylethene-bridged diporphyrins

Dithienylethene-bridged diporphyrins 1-6 were prepared as photochemical switching molecules. Porphyrin and dithienylethene are directly linked in 1, and linked, respectively, through a 1,4-phenylene spacer in 2, through a 4-ethynylphenylene spacer in 3, and through a di-4-phenylethynylene spacer in 4, while meso-ethynylated porphyrin and dithienylethene are directly connected in 5 and linked through a 1,4-phenylene spacer in 6. Compounds 1, 2, and 5 do not undergo any photochemical isomerization, probably due to efficient quenching of the excited dithienylethene by the attached porphyrin moiety via intramolecular energy transfer. Compounds 4 and 6 undergo open-to-closed and closed-to-open photoisomerizations in quantum yields of 4.3 x 10(-)(2) and 1.8 x 10(-)(3), and 2.6 x 10(-)(3) and 7.5 x 10(-)(4), respectively, by irradiation with 313 and 625 nm light, which are considerably smaller than quantum yields of 0.52 and 3.8 x 10(-)(3) for reference dithienylethene molecule 7. The fluorescence of 4 was regulated in a reversible manner by the photoisomerization of the dithienylethene moiety. In addition, the absorption properties of the porphyrin in 6 changed in response to the photochromic reaction of the dithienylethene bridge.

Synthesis of fluorescent diarylethenes having a 2,4,5-triphenylimidazole chromophore

Diarylethenes 1a-4a, having a fluorescent 2,4,5-triphenylimidazole chromophore in the aryl group, were synthesized. Upon excitation of the triphenylimidazole chromophore with 366 nm, 1a-4a underwent photocyclization reactions, and the solutions containing 1a-4a changed color from colorless to red-purple or to blue. The colors disappeared by irradiation with visible (lambda > 480 nm) light. The fluorescence intensity of the solutions also reversibly changed with the photochromic reactions. The fluorescence quantum yields of 1a, 2a, 3a, and 4a were determined to be 4.6, 7.7, 9.1, and 8.4%, respectively. The fluorescence quantum yields decreased with the increase in photocyclization quantum yields.

Recognition and transport characteristics of nonpeptidic compounds by basolateral peptide transporter in Caco-2 cells

Recent studies have revealed that diverse compounds lacking peptide bonds, such as valacyclovir and delta-aminolevulinic acid (delta-ALA), can be recognized by H+-coupled peptide transporters (PEPT1 and PEPT2). In the present study, recognition and transport characteristics of nonpeptidic compounds by the basolateral peptide transporter, which is distinct from PEPTs, were compared with those by PEPT1 using the human intestinal Caco-2 cells. [14C]Glycylsarcosine uptake via PEPT1 was inhibited by all nonpeptidic compounds tested. Similarly, most nonpeptidic compounds showed an inhibitory effect on [14C]glycylsarcosine uptake by the basolateral peptide transporter, although some kinds of nonpeptidic compounds, such as valine methyl ester, did not. Direct measurements of valacyclovir and delta-ALA transport revealed that both compounds were able to be transported by the basolateral peptide transporter. Because delta-ALA has been used recently in vitro and in clinical studies as an endogenous photosensitizer for photodynamic therapy, the intestinal transport characteristics of delta-ALA were further examined. Inhibition studies and Eadie-Hofstee plot analysis suggested that delta-ALA transport across the brush-border and basolateral membranes of the intestine was mainly mediated by peptide transporters. In addition, the apical-to-basolateral transport of delta-ALA was greater than that of the opposite direction. These findings provide the first evidence that the intestinal basolateral peptide transporter can recognize and transport nonpeptidic compounds, and play a definitive role in the absorption of delta-ALA.

Amino acid sequence and characterization of a rice bran ribonuclease

A base-nonspecific and acid ribonuclease (RNase Os) belonging to the RNase T2 family was purified from rice bran to a homogeneous state by SDS-PAGE. The primary structure of RNase Os was determined by protein chemistry and molecular cloning. The RNase Os was a simple protein and consisted of 205 amino acid residues. Its molecular weight was 22578 and its amino acid sequence showed that it was most similar to barley RNase among the known RNase T2 family enzymes having 157 amino acid residues identical with barley RNase. However, its N-terminus was blocked by a gamma-pyroglutamyl residue. The optimal pH of RNase Os was around 5.5. The base preference at the B1 and B2 site of RNase Os was estimated from the rates of hydrolysis of 16 dinucleoside phosphates, to be guanine as the case of RNase LE from tomato. RNase Os was successfully expressed from yeast cells using the E. coli yeast expression vector pYE-RNAP.

Current luting cements: marginal gap formation of composite inlay and their mechanical properties

OBJECTIVE

The aims of this investigation were to investigate the effect of thermocycling on the marginal gap formation of composite inlays using three types of luting cements (Compolute, PermaCem, Fuji Plus, Panavia 21: as a control) and on mechanical properties of four luting cements.

METHODS

The maximum marginal gap in the dentin cavity of each of ten resin inlay specimens in each group, was measured by a microscope before and after 10,000 thermocycles. The dimensional change, shear bond strength to dentin, and material and conditions for flexural strength and modulus testing were examined.

RESULTS

Compolute and Panavia 21 showed marginal gaps of approximately 10 microm before thermocycling. In contrast, the gap widths after thermocycling was significantly wider. Although the gap widths of PermaCem and Fuji Plus were approximately 60-110 microm prior to thermocycling, they were significantly smaller in width after thermocycling. Statistical differences in the shear bond strength to dentin were not observed before or after thermocycling for all materials. The flexural strength and modulus were significantly increased after thermocycling compared with three products and with all four products, respectively.

SIGNIFICANCE

The mechanical properties of all four luting cements were closely related to their marginal gap formations and these mechanical factors have important roles in determining their marginal gap formations.

Reversible surface morphology changes of a photochromic diarylethene single crystal by photoirradiation

The surface morphology of a diarylethene single crystal [1,2-bis(2,4-dimethyl-5-phenyl-3-thienyl)perfluorocyclopentene] determined by atomic force microscopy changed reversibly upon photoirradiation. The crystal underwent a thermally irreversible but photochemically reversible color change (colorless to blue) upon alternate irradiation with ultraviolet (wavelength lambda = 366 nm) and visible (lambda > 500 nm) light that drove reversible photocyclization reactions. Upon irradiation with 366-nm light, new steps appeared on the (100) single-crystalline surface that disappeared upon irradiation with visible light (lambda > 500 nm). The step height, about 1 nm, corresponds to one molecular layer. Irradiation with 366-nm light formed valleys on the (010) surface that also disappeared by bleaching upon irradiation with visible light (lambda > 500 nm). The surface morphological changes can be explained by the molecular structural changes of diarylethenes regularly packed in the single crystal. These crystals could potentially be used as photodriven nanometer-scale actuators.

Relationships between perceived workload, stress and oxidative DNA damage

OBJECTIVES

The present study was performed to investigate the relationship between work-related factors, including psychological stress, and the formation of a type of oxidative DNA damage, 8-hydroxydeoxyguanosine (8-OH-dG), in order to examine their possible risk factor for occupational carcinogenesis.

METHODS

A total of 54 healthy workers (27 male and 27 female, aged 41.2 +/- 12.5 years) in a company were investigated for 8-OH-dG levels in the peripheral blood leukocytes at the time of a questionnaire survey regarding several factors, such as working hours, workload, fatigue, sleep, psychological stress and the prospect of alleviating it. Subjects were limited to non-smoking and non-drinking workers to exclude the influence of cigarette smoking and alcohol drinking, which have been reported to have associations with the formation of 8-OH-dG.

RESULTS

The levels of 8-OH-dG in female subjects were significantly related to the perceived workload (F = 5.56, P = 0.010), the perceived psychological stress (F = 6.15, P = 0.007), and the impossibility of alleviating stress (F = 3.82, P = 0.048). No associations were observed in male subjects.

CONCLUSIONS

Psychological stress and perceived over-work appear to be related to the pathogenesis of cancer via the formation of 8-OH-dG, particularly in female workers.

Psychosocial factors as a potential trigger of oxidative DNA damage in human leukocytes

Although numerous studies have been carried out on the stress-cancer linkage, the results are still inconclusive. One of the useful, but rarely applied, methods to assess this linkage is to examine the relationship between psychosocial stress and cancer-predisposing genetic alterations simultaneously. We investigated whether various psychosocial factors can be associated with the levels of 8-hydroxydeoxyguanosine (8-OH-dG), a biomarker of cancer-related oxidative DNA damage, in peripheral blood leukocytes in 362 healthy workers (276 males and 86 females). After adjustments for age, body mass index, cigarette smoking, and alcohol use, female subjects showed positive relationships between the amount of 8-OH-dG and the Tension-Anxiety, Depression-Rejection, Anger-Hostility, Fatigue, and Confusion scores of the Profile of Mood States, respectively. The levels of 8-OH-dG also increased reliably in the female subjects who had poor stress-coping behaviors, particularly wishful thinking strategy, in the NIOSH general job stress instrument. There were positive relationships of the 8-OH-dG levels to average working hours, a self-blame coping strategy, and recent loss of a close family member in male subjects. These findings in a nonclinical sample of healthy adults not only provide evidence of a stress-cancer linkage, but also suggest possible sex differences in the mechanisms of stress-related cancer initiation.

Can conditioned histamine release occur under urethane anesthesia in guinea pigs?

Many clinical and experimental data have shown that learning can occur under general anesthesia. To clarify this possibility with respect to allergic reactions, particularly asthmatic responses, we first established classical conditioned histamine release in response to a neutral odor by using pairings of the odor and an inhaled antigen for five sessions (Experiment 1) and then investigated whether conditioned histamine release into the plasma, bronchoalveolar lavage fluid (BALF), and lung tissue, which followed such a conditioning procedure, would be produced in urethane-anesthetized guinea pigs in the presence or absence of antigen (Experiment 2). Ovalbumin (OA) was used as the unconditioned stimulus (US) and dimethylsulfide (DMS) served as the conditioned stimulus (CS) in both experiments. In Experiment 1, the plasma histamine levels in the conditioned group increased significantly more than those of the unpaired control group in response to the CS during consciousness. In Experiment 2 in the absence of antigen, however, no significant differences in the histamine levels were found regarding the groups (DMS, triethylamine, saline, or unsensitized) or the time course (before, immediately, 5 min, and 10 min after the inhalations) during anesthesia, except for the finding that the histamine levels in the lung tissue specimens from the DMS group were significantly higher than those from the triethylamine group. In Experiment 2 in the presence of antigen, there was a significant increase in the plasma histamine levels after exposure to the US, irrespective of the presence of the CS, however, no significant difference in the histamine levels was observed between the US and the CS+US groups. These results indicated that a classically CS might not induce asthmatic responses under anesthesia.

Enantioresolution and absolute stereochemistry of a photochromic bis(benzo[b]thienyl)ethene compound

The colored closed-ring isomers of a bis(benzo[b]thienyl) type photochromic diarylethene compound were enantioresolved by chiral column chromatography. The absolute stereochemistry of a (-)633-compound was determined by X-ray crystallography as (S,S). The relationship between the absolute stereostructure and the circular dichroism (CD) spectrum is discussed.

Marginal seal of resin-modified glass ionomers and compomers: effect of delaying polishing procedure after one-day storage

This study evaluated the effects of polishing after one-day storage in water on the marginal gap formation around fillings using three resin-modified glass ionomers, one compomer, one conventional glass ionomer, and one micro-filled composite as a control. The study also examined the marginal gap and bond strength in Teflon cavities and the flexural strength of these restorative materials, which may influence the marginal gap formation. Immediately after the setting procedure, the specimen was polished and a marginal gap of approximately 10-25 micrometers was observed regardless of the type of restorative material used. In contrast, we observed no gap or a 1-2 micrometer gap width when the specimens were polished after one-day storage. Only Dyract did not show this pattern. Statistical difference was observed between immediately polishing and polishing after one-day storage in all materials except Dyract. Hygroscopic expansion, bond strength and flexural strength play important roles in reducing the marginal gap in tooth cavities filled with two types of glass-ionomer restorative materials. In contract, these properties did not play important roles in reducing the marginal gap width for Dyract.

Enzymatic properties of phenylalanine101 mutant enzyme of ribonuclease rh from Rhizopus niveus

To investigate the role of Phe101, a component of a base recognition site (B2 site) of a base-nonspecific RNase Rh from Rhizopus niveus, we prepared several enzymes mutated at this position, F101W, F101L, F101I, F101A, F101Q, F101R, and F101K, and their enzymatic activities towards RNA, 16 dinucleoside phosphates, and 2', 3'-cyclic pyrimidine nucleotides were measured. Enzymatic activity toward RNA of F101W, F101L, and F101I were about 7, 20, and 3.8% of the native enzyme, respectively, and those of the other mutants were less than 1% of the RNase Rh. Similar results were also obtained with GpG as substrate. Thus, it was concluded that Phe101 is a very important residue as a component of the B2 site of RNase Rh, and its role could be replaced by Leu, then Trp and Ile, though in less effectively. The results suggested that some kind of interaction between B2 base and the side chain of amino acid residue at the 101th position, such as pi/pi or CH/pi interaction is very important for the enzymatic activity of RNase Rh. The mutation of Phe101 markedly affected the enzymatic activity toward dinucleoside phosphates and polymer substrates, but only moderately the rate of hydrolysis of cyclic nucleotides, indicating the presence of secondary effect of the mutation on B1 site.

Structural requirements for determining the substrate affinity of peptide transporters PEPT1 and PEPT2

Peptide transporters PEPT1 and PEPT2 transport numerous compounds including small peptides, peptide-like drugs and nonpeptidic compounds such as valacyclovir. PEPT1 and PEPT2 show low and high affinity for most substrates, respectively, but beta-lactam antibiotics without an alpha-amino group are the only known substrates that prefer PEPT1 to PEPT2. The aim of this study was to compare the recognition and affinity of various substrates between rat PEPT1 and rat PEPT2, and to determine the structural requirements influencing the substrate affinity. [14C]Glycylsarcosine uptake by PEPT1- or PEPT2-expressing transfectant was inhibited by di- and tripeptides, but not by amino acids, tetrapeptides or most cyclic dipeptides. All dipeptides and tripeptides examined showed more potent inhibition of [14C]glycylsarcosine uptake via PEPT2 than via PEPT1, irrespective of their charge and structure. Modification of the alpha-amino group of dipeptides reduced their substrate affinity to both transporters, as compared to unmodified dipeptides, but these dipeptides still showed potent inhibitory effects on PEPT2. Among the nonpeptidic substrates tested, only the eight-amino-octanoic acid displayed stronger inhibition of [14C]glycylsarcosine uptake in PEPT1 than in PEPT2. These findings suggest that alpha- or beta-amino carbonyl function is the key structure responsible for the higher affinity for PEPT2 than for PEPT1.

Syntheses of optically active trifluoronorcoronamic acids

Syntheses of optically active trifluoronorcoronamic acid 6 and its diastereomer 9 are described. Highly stereospecific and diastereoselective S(N)2 cyclization of gamma-cyanohydrins 3a and 3b gave cyclopropyl nitriles 4a and 4b. Hydrolysis of the cyano group and deprotection of the amino group of 4a provide trifluoronorcoronamic acid 6. Hofmann rearrangement of the amide which was generated by hydrolysis of the cyano group and oxidative cleavage of the aryl ring of 4b to provide trifluoro-allo-norcoronamic acid 9.

Classical conditioning of oxidative DNA damage in rats

This study investigated whether the formation of 8-hydroxydeoxyguanosine (8-OH-dG), a known oxidative DNA modification relevant to carcinogenicity, can be classically conditioned to a novel taste in order to clarify the possible role of the central nervous system (CNS) or psychological stress on cancer initiation via a classical conditioning mechanism. Male Wistar rats underwent one or two conditioned taste aversion (CTA) experiments in which ferric nitrilotriacetate (Fe-NTA), which has renal toxicity and can induce renal cell carcinoma, served as a visceral unconditioned stimulus (US), and a saccharin solution (SAC) was used as a conditioned stimulus (CS). The 8-OH-dG levels in the group conditioned with the combination of SAC and Fe-NTA significantly increased as compared to those of the uncombined groups by two repeats of the conditioning procedure (P=0.013). The rats that showed a painful response at the Fe-NTA administration had significantly higher values of 8-OH-dG than those without pain (P=0. 003). These results not only provide the first evidence regarding classical conditioning of oxidative DNA damage using the CTA procedure, but also suggest the involvement of the CNS and psychological stress in the pathogenesis of cancer via oxidative DNA damage.

Relationship of two ribonucleases with molecular masses of 45 kDa and 37 kDa from the culture medium of Lentinus edodes

Lentinus edodes (shiitake) produces three base non- specific and acid ribonucleases, RNase Le2, RNase Le37 and RNase Le45. The primary structures of the former two RNases, having molecular masses about 24 and 37 kDa, respectively, have been elucidated to be members of the RNase T2 family. The latter two are excreted from mycelia into the medium. In this report, we estimated the primary structure of RNase Le45 using the following experimental evidence. (i) The partial amino acid sequence of RNase Le45 determined that up to about 60% of total protein was identical with that of RNase Le37. (ii) The amino acid composition of RNase Le45 was identical to that of RNase Le37. (iii) The elution profiles on HPLC of lysylendopeptidase and Staphylococcus aureus V8 protease digests of RCM-RNase Le45 (reduced and S-carboxymethylated RNase Le45) were very similar to those of RNase Le37, except for the absence of C-terminus peptide which contained O-glycosylated peptides. However, RNase Le45 contained about 70 residues of mannose and 4 residues of hexosamine. These values were more than twice those of RNase Le37. (iv) RNase Le45 was immunologically indistinguishable from RNase Le37. (v) After treatment with both glycosidase EndoH and alpha-mannosidase, RNases Le37 and Le45 gave complex bands by slab-gel electrophoresis. However, one of the major bands with the highest mobility from RNase Le45 and Le37 showed the molecular mass of 29 kDa in common, which is slightly larger than that of RNase Le2 containing no carbohydrate. These results indicated that RNase Le45 is an enzyme which is a heavily glycosylated species of RNase Le37.

Crystal structure of a plant ribonuclease, RNase LE

Ribonuclease LE (RNase LE) from cultured tomato (Lycopersicon esculentum) cells is a member of the RNase T(2) family showing broad base specificity. The crystal structure of RNase LE has been determined at 1.65 A resolution. The structure consists of seven alpha-helices and seven beta-strands, belonging to an alpha+beta type structure. Comparison of the structure of RNase LE with that of RNase Rh, a microbial RNase belonging to the RNase T(2) family, reveals that while the overall folding topologies are similar to each other, major insertions and deletions are found at the N-terminal regions. The structural comparison, an amino acid sequence alignment of the RNase T(2) enzymes, and comparison of the disulfide-bonding pattern of these enzymes show that the structure of RNase LE shown here is the basic framework of the animal/plant subfamily of RNase T(2) enzymes (including a self-incompatibility protein called S-RNase), and the structure of RNase Rh is that of the fungal subfamily of RNase T(2) enzymes (including RNase T(2)). Subsequently, we superposed the active-site of the RNase LE with that of RNase Rh and found that (1) His39, Trp42, His92, Glu93, Lys96, and His97 of RNase LE coincided exactly with His46, Trp49, His104, Glu105, Lys108, and His109, respectively, of RNase Rh, and (2) two conserved water molecules were found at the putative P(1) sites of both enzymes. These facts suggest that plant RNase LE has a very similar hydrolysis mechanism to that of fungal RNase Rh, and almost all the RNase T(2) enzymes widely distributed in various species share a common catalytic mechanism. A cluster of hydrophobic residues was found on the active-site face of the RNase LE molecule and two large hydrophobic pockets exist. These hydrophobic pockets appear to be base binding sites mainly by hydrophobic interactions and are responsible for the base non-specificity of RNase LE.

Amino acid sequence of a nuclease (nuclease Le1) from Lentinus edodes

The fruit bodies of Lentinus edodes produce two acid nucleases, nucleases Le1 and Le3, both of which are thought to be candidates for the enzymes producing a tasty substance, 5'-GMP. To obtain the basic information on the mechanism of production of 5'-GMP, and structure-function relationship of these nucleases, the primary structure of nuclease Le1 was estimated by both protein chemistry and gene cloning. Nuclease Le1 is a glycoprotein and consists of 290 amino acid residues, and about 2 and 6 residues of hexosamine and neutral sugar, respectively. The nucleotide sequence of cDNA and genomic DNA encoding nuclease Le1 indicated the presence of 20 amino acid residues of a signal peptide. Nuclease Le1 has 115 and 108 residues of identical amino acid residues with nucleases P1 and S, respectively. The amino acid residues concerning the coordination with Zn2+ in nuclease P1 are all conserved in nuclease Le1. Nuclease Le1 contains 8 half-cystine residues and 4 of them are located at the same places as those of nucleases P1 and S.

Simple microplate method for determination of urinary iodine

BACKGROUND

Urinary iodine is a good biochemical marker for control of iodine deficiency disorders. Our aim was to develop and validate a simple, rapid, and quantitative method based on the Sandell-Kolthoff reaction, incorporating both the reaction and the digestion process into a microplate format.

METHODS

Using a specially designed sealing cassette to prevent loss of vapor and cross-contamination among wells, ammonium persulfate digestion was performed in a microplate in an oven at 110 degrees C for 60 min. After the digestion mixture was transferred to a transparent microplate and the Sandell-Kolthoff reaction was performed at 25 degrees C for 30 min, urinary iodine was measured by a microplate reader at 405 nm.

RESULTS

The mean recovery of iodine added to urine was 98% (range, 89-109%). The theoretical detection limit, defined as 2 SD from the zero calibrator, was 0.11 micromol/L (14 microg/L iodine). The mean intra- and interassay CVs for samples with iodine concentrations of 0.30-3.15 micromol/L were < or = 10%. The new method agreed well with the conventional chloric acid digestion method (n = 70; r = 0.991; y = 0.944x + 0.04; S(y|x) = 0.10) and with the inductively coupled plasma mass spectrometry method (n = 61; r = 0.979; y = 0.962x + 0.03; S(y|x) = 0.20). The agreement was confirmed by difference plots. The distributions of iodine concentrations for samples from endemic areas of iodine deficiency diseases showed similar patterns among the above three methods.

CONCLUSIONS

Our new method, incorporating the whole process into a microplate format, is readily applicable and allows rapid monitoring of urinary iodine.

Serum concentrations of 20K human growth hormone in normal adults and patients with various endocrine disorders. Study Group of 20K hGH

The 20K hGH isoform is produced by alternative splicing of GH mRNA, and comprises approximately 10% of all GH in the pituitary. The physiological role of 20K hGH remains to be determined partly because of the lack of a simple and specific assay. We have established sensitive enzyme-linked immunoadsorbent assays (ELISAs) specific to 20K and 22K hGH. The serum levels of 20K hGH after overnight fasting was 118 +/- 178 pg/mL (N=282) in normal women, significantly higher than in normal men (64 +/- 170 pg/mL, N=226). However, there was no difference in the proportion of 20K hGH to 20K plus 22K hGH between men (6.3 +/- 2.6%, N=176) and women (6.3 +/- 2.1%, N = 263). No correlation was detected between the ratio of 20K hGH and age, body height, body weight or body fat mass in normal subjects. The proportion of 20K hGH was significantly (P < 0.001) higher in patients with active acromegaly (9.2 +/- 2.2%, N=33) and in patients with anorexia nervosa (9.0 +/- 1.9, N=8), both of which are characterized by chronic elevation of circulating GH levels. The proportion of the 20K hGH in successfully treated acromegalic patients did not differ from that in normal subjects, suggesting that GH-producing pituitary tumors secrete a higher proportion of 20K hGH, or chronic excess of 22K hGH altering the metabolic clearance rate of 20K hGH. The values in patients with adult growth hormone deficiency (GHD), hyperthyroidism, primary hypothyroidism, or GH-independent short stature did not differ from those in normal subjects. The 20K ratio did not change after acute GH provocative tests such as insulin tolerance test and GRH test. These results suggest that secretion of 20K hGH from the pituitary is under the same control as that of 22K hGH.

Amino acids and peptides. LVII. Synthetic peptide with a sequence of ribonuclease from Sulfolobus solfataricus, SSR(1-62), does not function as an RNase

The 62 residue peptide, SSR(1-62), whose sequence corresponds to that of ribonuclease (RNase) from Sulfolobus solfataricus, and its related peptides, SSR(1-22) and SSR(10-62), were chemically synthesized and their RNase activity and DNA-binding activity were examined. The RNase activity assay using yeast RNA or tRNA(fMet) as substrate showed that the synthetic peptide SSR(1-62) did not hydrolyze yeast RNA or tRNA(fMet). These data were not consistent with previous reports that both the native peptide isolated from S. solfataricus [Fusi et al. (1993) Eur. J. Biochem. 211, 305-311] and the recombinant peptide expressed in Escherichia coli [Fusi et al. (1995) Gene 154, 99-103] were able to hydrolyze tRNA(fMet). However, the synthetic SSR(1-62) exhibited DNA-binding activity. In the presence of synthetic SSR(1-62), the cleavage of DNA (plasmid pUCRh2-4) by restriction endonuclease (EcoRI) was not observed, suggesting that synthetic SSR(1-62) bound to DNA protected DNA from its enzymatic digestion. Neither SSR(1-22) nor SSR(10-62) prevented DNA from being cleaved by a restriction enzyme. These findings strongly suggest the importance of not only the N-terminal region of SSR(1-62) but also the C-terminal region for DNA-binding. Circular dichroism spectroscopy of synthetic SSR(1-62) indicated a beta-sheet conformation, in contrast with synthetic SSR(1-22), which exhibited an unordered conformation.

Detection of exogenous growth hormone (GH) administration by monitoring ratio of 20kDa- and 22kDa-GH in serum and urine

We previously demonstrated that individual subjects have fairly constant ratios of serum concentrations of 20 kDa- (20K) and 22 kDa-GH (22K). The aim of this study is to demonstrate the possibility of utilizing the changes in the ratio of 20K/22K for detecting the exogenous administration of 22K. A male patient with idiopathic dilated cardiomyopathy (age 51) received 22K (4U, s.c.) every other day. The concentrations of 20K and 22K in serum and urine were measured using enzyme-linked immunosorbent assays before and after administration. The administration of 22K increased total GH concentration, and markedly decreased the ratio of 20K/22K in serum, especially 2-10 h after the administration. From calculations, it became clear that the concentration of exogenous 22K reached a peak between 2-4 h after the administration and decreased to a negligible level after 24 h. The ratio of 20K/22K in the 0-24 h urine was 5 times lower than that in the 24-48 h urine. These data suggest that, by monitoring the ratio of 20K/22K in serum or urine, it is possible to determine whether or not GH has been externally administered and to calculate the serum GH that has been administered.

Amino acid sequence of an unique ribonuclease with a C-terminus rich in O-glycosylated serine and threonine from culture medium of Lentinus edodes

The mushroom Lentinus edodes produces three base-non-specific and acid ribonucleases, RNases Le2, Le37, and Le45. The latter two are excreted from mycelia into the medium. The primary structure of RNase Le37, which had a molecular mass of 37 kDa, was sequenced. It was a member of the RNase T2 family, as is RNase Le2. RNase Le37 was some 30 amino acid residues longer at the C-terminal end than RNase Le2. The C-terminal region of RNase LE37 was rich in O-glycosylated serine and threonine. In fungal glucoamylases and chitinases, which hydrolyze raw-starch and chitin, respectively, have structures resembling the structure of the C-terminal of RNase Le37.

[Fundamental and clinical study of three-dimensional compensating filters and direct dose monitoring system for total body irradiation]

We devised 3D-compensating filters to improve dose distribution during total body irradiation (TBI). This study investigated the effect of these 3D-compensating filters and related complications in patients who had undergone bone marrow transplantation (BMT) followed by TBI. The 3D-compensating filters were fabricated by CT measurement of body thickness. The effectiveness of the 3D-compensating filters in producing a homogeneous dose distribution was checked by a thermoluminescent dosimeter (TLD) and semiconductor detectors in all patients. At the pelvis, the dose was measured simultaneously with an ionization chamber. The average dose distribution to each site when the 3D-compensating filter was used was 93% to the head, 97% to the neck, 99% to the thorax, and 98% to the pelvis in TLD when the scheduled dose was taken as 100%. There was no significant difference between the TBI and non-TBI groups with regard to the frequency of lung toxicity. Clinical interstitial pneumonitis occurred in 22.7% of the patients, interstitial pneumonitis with CMV in 13.6%, and idiopathic pneumonitis in 6.1% without any virus infection. Only one patient was regarded as having radiation-induced pneumonitis. 3D-compensating filters can be conveniently produced within a short time following CT measurement, and they seem to be safe and useful for dose flattening during TBI.

Marginal gap formation of light-activated base/liner materials: effect of setting shrinkage and bond strength

OBJECTIVES

The purpose of this study was to compare the effect of setting shrinkage and the shear bond strength on the marginal gap formation in dentin cavities of commercially available light-activated base/liner materials during the early stage of setting, with those of chemical-cured base/liner materials.

METHODS

The maximum marginal gap width and the opposing width in the dentin cavity was measured 30 min after the start of mixing. The setting shrinkage and shear bond strength to dentin was measured as the same procedure. To estimate the setting shrinkage, the maximum marginal gap width and the opposing width that occurred with materials placed in a Teflon cavity was measured.

RESULTS

The two light-activated base/liner materials produced a significantly wider marginal gap than the chemical-cured base/liner materials (p < 0.05). There were no significant differences in the width of the marginal gap between the remaining five light-activated base/liner and chemical-cured base/liner materials (p > 0.05). The material that produced the smaller marginal gap width in the dentin cavity had a smaller marginal gap width in the Teflon cavity. There was a highly significant correlation between the two findings (r = 0.93, p < 0.01). However, shear bond strength to dentin had no effect on the marginal gap in the dentin cavity (r = 0.04, p > 0.50).

SIGNIFICANCE

It appeared that the setting shrinkage of light-activated base/liner materials in the early stage of setting had a greater effect on the marginal gap formation in the dentin cavity than the bond strength to the dentin structure.

Evaluation of porcine fat with fiber-optic spectroscopy

Spectroscopy using four types of fiberoptic probes and a sensor at wavelengths of 400 to 1,100 nm was evaluated to assess porcine fat quality. The shapes of the spectrum for the leaf fat with white color and various firmnesses differed with the type of probe: surface, contact, insertion, or transmittance. The internal reflectance ratio using the insertion probe at wavelengths from approximately 600 to 1,000 nm was positively correlated with the hardness, melting point, and saturated fatty acid content of the fat, but it was negatively correlated with the refractive index and polyunsaturated fatty acid content. The correlations between the internal reflectance ratio using the insertion probe and the monounsaturated fatty acid content were strong only near 1,100 nm. Surface reflectance at more than 650 nm was negatively correlated with refractive index. Transmittance at almost all wavelengths showed positive correlations with monounsaturated fatty acid content, but it was negatively correlated with hardness, melting point, and saturated fatty acid content. The interactance using the contact probe did not have a significant correlation with any physiochemical characteristics. The strongest relationships for hardness, refractive index, saturated fatty acid content, monounsaturated fatty acid content, polyunsaturated fatty acid content, and melting point were obtained at 650 nm (r = .88), 660 nm (r = -.91), 645 nm (r = .73), 1,095 nm (r = .68), and 930 nm (r = -.76), respectively, using the insertion probe and 1,050 nm (r = -.79) using the transmittance probe (P<.05). These results indicated that fiber-optic methods were rapid and useful techniques for the evaluation of porcine fat quality.

Water storage effect on the marginal seal of resin-modified glass-ionomer restorations

The effect of storage in water on the marginal adaptation of glass-ionomer restorations placed in extracted human premolars and Teflon molds was studied. When the cavity preparations were filled with a glass ionomer and polished immediately after setting, a marginal gap of approximately 15 microns was formed. In contrast, when polishing following storage in water the marginal gap was 0 to 2 microns for the resin-modified and the conventional glass ionomers respectively. The bond strength of the glass ionomer to enamel and to dentin and the flexural strength of the glass ionomer increased after storage in water. Therefore the marginal seal of glass-ionomer restorations may not only be improved due to hygroscopic expansion during storage in water but also may exhibit greater bond strength.

Computed tomographic epidurography: an aid to understanding deformation of the lumbar dural sac by epidural injections

Local anaesthetics injected into the epidural space may deform the dural sac to a variable degree, thereby contributing to variability in the extent of the block. We investigated deformation of the lumbar dural sac after injection into the lumbar epidural space. The subjects were 26 patients with low-back pain who underwent lumbar epidurography and computed tomographic (CT) epidurography, of whom seven also underwent myelography and computed tomographic myelography. The epidural space was entered via the sacral hiatus in 24 patients and through the L5/S1 interspace in two patients. Ten millilitres of local anaesthetic was then injected into the epidural space followed by 20 mL of contrast medium. Computed tomographic epidurography was undertaken approximately 30-min after the epidural injection at the mid-vertebral and mid-discal levels from the first lumbar through to the first sacral vertebrae. The dural sac usually showed an oval or hexagonal shape on the transverse views at the first and second lumbar vertebral levels, and the shape of an inverted triangle below the level of the third lumbar vertebra. A median line of translucency was also observed on the posteroanterior epidurographic view in 25 of the 26 patients. This line was though to be a manifestation of the dural deformation to the inverted triangle. Dural sac deformation usually shows a specific pattern, although there are individual variations. Dural deformability is an important consideration in any analysis of the spread of epidural block or of the changes of epidural pressure after epidural injection of local anaesthetics.

Theoretical study of signal-to-noise ratio on near-field photochromic memory with fluorescence readout

The signal-to-noise ratio (SNR) on the fluorescence readout of a near-field photochromic memory was theoretically studied. Under various conditions the shot-noise-limited SNR was analyzed. SNR by bright spot recording (BSR) that was better than that by dark spot recording (DSR) was obtained under the condition of low writing power or wide bandwidth. Under the condition of bandwidth W = 1 MHz and P(write) = 10(-8) W only BSR can attain sufficiently high SNR, and the SNR was greater by as much as 30 dB than that of DSR. It was concluded that BSR is a promising method for high-density near-field photochromic memory with a fluorescence readout.

Amino acids and peptides. LV. Application of 2-adamantyl derivatives as protecting groups to the synthesis of peptide fragments related to Sulfolobus solifataricus ribonuclease. II

Segment condensations were performed to construct peptide fragments related to Sulfolobus solifataricus Ribonuclease. At each condensation step, the new protecting groups were stable. The protected peptide fragments were treated with a low-high HF procedure to give the desired peptide fragments. These peptide fragments were also prepared by the solid-phase method, and the obtained peptides were compared with those obtained by the solution method. The peptide fragments obtained by the solution method were identical with those obtained by the solid-phase method on analytical HPLC, indicating that the new protecting groups could be easily removed by HF, and no racemization occurred during the synthesis of the protected peptides.

Amino acids and peptides. LIV. Application of 2-adamantyl derivatives as protecting groups to the synthesis of peptide fragments related to Sulfolobus solifataricus ribonuclease. I

The 2-adamantyloxycarbonyl group was employed for the protection of the epsilon-amino group of Lys and the hydroxyl group of Tyr, and the 2-adamantyl ester was employed for the protection of the beta-carboxyl group of Asp in order to construct eight peptide segments as building blocks for the preparation of peptide fragments related to the sequence of Sulfolobus solifataricus Ribonuclease. The usefulness of the above protecting groups developed in our laboratory was confirmed.

Cilnidipine, the N- and L-type calcium channel antagonist, reduced on 24-h urinary catecholamines and C-peptide in hypertensive non-insulin-dependent diabetes mellitus

To evaluate the effects of cilnidipine (CNP), L- and N-type calcium channel blocker and nilvadipine (NVP) on 24-h urinary epinephrine (U-EP), norepinephrine (U-NE), dopamine (U-DA) and C-peptide (U-CPR) in patients associated with hypertension and non-insulin-dependent diabetes mellitus (HT-NIDDM), a randomized crossover study was performed with 35 HT-NIDDM patients. The patients were given CNP (10 mg/day) and NVP (8 mg/day), separately, for 4 weeks each. After CNP treatment, U-NE, U-DA and U-CPR levels were significantly reduced compared with pre-treatment levels: 160.4 +/- 12.7 to 111.7 +/- 8.9 microg/day (mean +/- S.E., P < 0.005); 934.8 +/- 163.4 to 590.3 +/- 33.4 microg/day (P < 0.05); 86.7 +/- 9.9 to 57.6 +/- 7.4 microg/day (P < 0.05), respectively. Although no significant differences were observed in U-EP, U-NE, U-DA and U-CPR levels by NVP treatment, U-NE, U-DA and U-CPR levels after CNP treatment were significantly lower than those after NVP treatment: 111.7 +/- 8.9 versus 155.0 +/- 13.7 microg/day (P < 0.02); 590.3 + 33.4 versus 822.2 +/- 104.3 microg/day (P < 0.05); 57.6 +/- 7.4 versus 80.6 +/- 8.1 microg/day (P < 0.05), respectively. In conclusion, it was demonstrated that CNP treatment significantly reduced U-NE, U-DA and U-CPR excretion compared with NVP treatment in HT-NIDDM patients.

Purification and characterization of caffeine synthase from tea leaves

Caffeine synthase (CS), the S-adenosylmethionine-dependent N-methyltransferase involved in the last two steps of caffeine biosynthesis, was extracted from young tea (Camellia sinensis) leaves; the CS was purified 520-fold to apparent homogeneity and a final specific activity of 5.7 nkat mg-1 protein by ammonium sulfate fractionation and hydroxyapatite, anion-exchange, adenosine-agarose, and gel-filtration chromatography. The native enzyme was monomeric with an apparent molecular mass of 61 kD as estimated by gel-filtration chromatography and 41 kD as analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme displayed a sharp pH optimum of 8.5. The final preparation exhibited 3- and 1-N-methyltransferase activity with a broad substrate specificity, showing high activity toward paraxanthine, 7-methylxanthine, and theobromine and low activity with 3-methylxanthine and 1-methylxanthine. However, the enzyme had no 7-N-methyltransferase activity toward xanthosine and xanthosine 5'-monophosphate. The Km values of CS for paraxanthine, theobromine, 7-methylxanthine, and S-adenosylmethionine were 24, 186, 344, and 21 microM, respectively. The possible role and regulation of CS in purine alkaloid biosynthesis in tea leaves are discussed. The 20-amino acid N-terminal sequence for CS showed little homology with other methyltransferases.

Isolation and characterization of mammalian homologues of Caenorhabditis elegans lin-7: localization at cell-cell junctions

In Caenorhabditis elegans, the vulval induction is mediated by the let-23 receptor tyrosine kinase (RTK)/ Ras signaling pathway. The precise localization of the let-23 RTK at the epithelial junctions is essential for the vulval induction, and requires three genes including lin-2, -7, and -10. The mammalian homologue of lin-2 has been identified as a protein interacting with a neuronal adhesion molecule, neurexin, and named CASK. CASK has recently been reported to interact with syndecans and an actin-binding protein, band 4.1, at epithelial and synaptic junctions, and to play central roles in the formation of cell-cell junctions. The product of C. elegans lin-7 directly interacts with let-23 RTK and localize it at epithelial junctions. Here, we report three rat homologues of lin-7 ubiquitously expressed in various tissues. These homologues are accumulated at the junctional complex region in cultured Madin-Darby canine kidney cells, and are also localized at the synaptic junctions in neurons. The mammalian homologues of lin-7 may be implicated in the formation of cell-cell junctions.

Putative hemochromatosis gene mutations and alcoholic liver disease with iron overload in Japan

It is well known that alcoholic liver disease is associated with iron overload. To study the role of hemochromatosis gene mutations on the pathogenesis of alcoholic liver disease (ALD), we have analyzed C282Y and H63D mutations on the chromosomes obtained from 95 Japanese alcoholics. Patients were divided in two groups [i.e., 64 alcoholic patients with liver damage (group I) and 31 alcoholics without liver damage (group II)]. In group I, biochemical examinations showed that serum levels of iron and ferritin were significantly high, and unsaturated iron binding capacity levels were low, compared with those of group II. An analysis by means of allele-specific polymerase chain reaction demonstrated that C282Y mutation was not observed in both groups I and II. H63D mutation was observed in only two heterozygotes of group I and in one heterozygote of group II. Results could not indicate the relationship between ALD and these mutations. We speculate that other causes of iron overload may exist in ALD with iron overload.

Differential localization and activity of the A- and B-forms of the human progesterone receptor using green fluorescent protein chimeras

Subcellular localization and transcriptional activity of green fluorescent protein-progesterone receptor A and B chimeras (GFP-PRA and GFP-PRB) were examined in living mammalian cells. Both GFP-PRA and B chimeras were found to be similar in transcriptional activity compared with their non-GFP counterparts. GFP-PRA and PRA were both weakly active, while GFP-PRB and PRB gave a 20- to 40-fold induction using a reporter gene containing the full-length mouse mammary tumor virus long-terminal repeat linked to the luciferase gene (pLTRluc). Using fluorescence microscopy, nuclear/cytoplasmic distributions for the unliganded and hormone activated forms of GFP-PRA and GFP-PRB were characterized. The two forms of the receptor were found to have distinct intracellular distributions; GFP-PRA was found to be more nuclear than GFP-PRB in four cell lines examined. The causes for and implications of this differential localization of the A and B forms of the human PR are discussed.

The effect of primers on bond strength of polyacid-modified resin composites (compomers)

This study evaluated the effect of primer on shear bond strength and marginal gaps of six new compomers immediately after light-activation. A resin-modified glass ionomer cement, a conventional glass-ionomer cement and a microfilled composite were used for comparison. The marginal gap widths of each of the four compomers and a microfilled composite used with the primer were significantly smaller compared with those used without the primer. The bond strength values of five compomers used with the primer were significantly higher than those used without the primer. The bond strength of conventional glass-ionomer was not affected by the primer (or the conditioner).

Structure-function relationships of acid ribonucleases: lysosomal, vacuolar, and periplasmic enzymes

It is surprising that only relatively recently has attention been directed to the characterization of the properties of acid ribonucleases (RNases), leading to some understanding of their biochemistry and their functional roles. The present review summarizes current progress in this field under the following general topics: (1) the wide distribution of acid RNases in organisms from viruses to animals; (2) recent findings concerning their primary and three-dimensional structure; (3) the structure-function relationship of acid RNases, with a fungal RNase from Rhizopus niveus as a model enzyme; (4) the unique localization of acid RNases in the periplasm of bacteria, vacuoles in plants, and lysosomes of animals and protozoa; and (5) the diversity of physiological roles, depending on the organism, such as self-incompatibility factors and defense proteins in some plants, the surface protein of an animal virus related to pathogenicity, and possible relationship to human cancer.

Comparison of base specificity and other enzymatic properties of two protozoan ribonucleases from Physarum polycephalum and Dictyostelium discoideum

Base specificity and other enzymatic properties of two protozoan RNases, RNase Phyb from a true slime mold (Physarum polycephalum) and RNase DdI from a cellular slime mold (Dictyostelium discoideum), were compared. These two RNases have high amino acid sequence similarity (83 amino acid residues, 46%). The base specificities of two base recognition sites, The B1 site (base recognition site for the base at 5'-side of scissile phosphodiester bond) and the B2 site (base recognition site for the base at 3'-side of the scissile bond) of the both enzymes were estimated by the rates of hydrolysis of 16 dinucleoside phosphates. The base specificities estimated of B1 and B2 sites of RNase Phyb and RNase DdI were A, G, U > C and A > or = G > C > U, and A > or = G, U > C and G > U > A, C, respectively. The base specificities estimated from the depolymerization of homopolynucleotides and those from the releases of four mononucleotides upon digestion of RNA coincided well with those of the B2 sites of both enzymes. Thus, in these enzymes, the contribution of the B2 site to base specificity seems to be larger than that of the B1 site. pH-stability, optimum temperature, and temperature stability, of both enzymes are discussed considering that RNase Phyb has one disulfide bridge deleted, compared to the RNase DdI with four disulfide bridges.

Antifungal activity of radicicol against Mucor flavus IFO 9560

The antifungal activity of radicicol against Mucor flavus IFO 9560 was investigated. Radicicol induced bursting of spores during germination and morphological changes of the mycelial tip such as overbranching and swelling during exponential growth. In addition, radicicol showed a dose-dependent inhibitory effect on spore germination. Radicicol also inhibited the incorporation of radioactive precursors into DNA, RNA, protein, and chitin fractions by 20-30%, but not into the lipid fraction. There were no inhibitory effects on either endogenous or exogenous cellular respiration. Moreover, leakage of UV-absorbing, phenol sulfate-positive, or folin reagent-positive materials from the mycelia was not observed at an early stage of growth inhibition. On the other hand, kinetic studies of chitin synthase in the untreated mycelia revealed that radicicol noncompetitively inhibited the enzyme at Ki of 87 microM. Furthermore, upon incubation of the normal mycelia with radicicol in 50 mM KH2PO4-NaOH buffer (pH 6.5) containing 10 mM MgCl2, chitin synthase from the mycelia was inactivated gradually at first, and completely after 24-h incubation. These results suggested that radicicol exhibits the antifungal activity by disturbing cell wall biosynthesis through the inactivation of chitin synthase. However, at an early stage of growth inhibition, radicicol was thought to affect cellular function including nucleic acid and protein syntheses, in addition to the reversible noncompetitive inhibition of chitin synthase.

Primary structure, expression, and site-directed mutagenesis of inorganic pyrophosphatase from Bacillus stearothermophilus

The complete primary structure of inorganic pyrophosphatase [EC 3.6. 1.1] from Bacillus stearothermophilus (ATCC 12016) was determined at the amino acid level by automated Edman degradation. The subunit of the enzyme consists of 164 amino acid residues with a calculated molecular mass of 18,796. The amino acid sequence of the enzyme is almost identical to that of thermophilic bacterium PS-3. Based on the determined primary structure, a PCR-amplified semi-synthetic gene was constructed and expressed in Escherichia coli JM109. The recombinant Bst. PPase showed the same characteristics and activity as the authentic enzyme, and exhibits higher thermostability than the E. coli enzyme. Furthermore, we prepared tyrosine-substituted variants by site-directed mutagenesis to elucidate the role of two highly conserved tyrosines (Y46 and Y130). As a result, two variants, Y46F and Y130F, lost most of their enzyme activity, whereas their conformations were unaffected. However, the wild-type and two variants exhibited different thermostability behaviors in the presence or absence of Mg2+. Therefore, these tyrosines may contribute to the structural integrity of the active site of the enzyme.

Serum concentration of 20K human growth hormone (20K hGH) measured by a specific enzyme-linked immunosorbent assay. Study Group of 20K hGH

Several GH isoforms have been identified in pituitary and serum, the most abundant of which is the 22K human GH (hGH) isoform. The 20K hGH isoform is produced by alternative splicing of GH messenger ribonucleic acid and comprises approximately 10% of all GH in the pituitary. The physiological role of 20K hGH remains to be determined, partly because of the lack of a simple and specific assay. We have established sensitive enzyme-linked immunosorbent assays (ELISAs) specific to 20K and 22K hGH. To determine whether regulation of 20K hGH secretion is the same as that for 22K hGH, we measured serum concentrations of both species of hGH in normal subjects and patients with a variety of endocrine disorders. The serum levels of 20K hGH after overnight fasting was 118 +/- 178 pg/mL (n = 282) in normal women, significantly higher than that in normal men (64 +/- 170 pg/mL; n = 226). However, there was no difference in the proportion of 20K hGH to 20K plus 22K hGH between men (6.3 +/- 2.6%, mean +/- SD; n = 176) and women (6.3 +/- 2.1%; n = 263). No correlation was detected between the ratio of 20K hGH and age, body height, body weight, or body fat mass in normal subjects. The proportion of 20K hGH was significantly (P < 0.001) higher in patients with active acromegaly (9.2 +/- 2.2%; n = 33) and patients with anorexia nervosa (9.0 +/- 1.9; n = 8), both of which are characterized by chronic elevation of circulating GH levels. The proportion of 20K hGH in successfully treated acromegalic patients did not differ from that in normal subjects, suggesting that GH-producing pituitary tumors secrete a higher proportion of 20K hGH, or that a chronic excess of 22K hGH alters the MCR of 20K hGH. The values in patients with adult GH deficiency, hyperthyroidism, primary hypothyroidism, or GH-independent short stature did not differ from those in normal subjects. The 20K ratio did not change after acute GH provocative tests, such as the insulin tolerance test and the GHRH test. These results suggest that secretion of 20K hGH from the pituitary is under the same control as that of 22K hGH. This new assay may provide a tool for understanding the physiological or pathophysiological role of the 20K hGH isoform.

Great earthquakes and medical information systems, with special reference to telecommunications

The Hanshin-Awaji earthquake in January 1995 caused the greatest number of deaths and injuries in Japan since World War II. Various weaknesses of modern information systems were exposed during and after the earthquake. The authors carried out a questionnaire survey to investigate the current state of hospital information and to examine the kinds of information needed immediately after an earthquake. The survey results show that information about the ability to admit new patients and the availability of medical supplies is necessary immediately after such a disaster. These results will be useful for planning countermeasures against this kind of disaster.