[Pharmacokinetics of isosorbide dinitrate studied by the extrapolation model]

To make a pharmacokinetic model of isosorbide dinitrate (ISDN), we infused ISDN at 1, 10 or 30 micrograms.kg-1.min-1 into anesthetized rabbits and measured concentrations of ISDN and its metabolites (2-ISMN and 5-ISMN) in plasma, urine and bile. We found the concentration gradient of ISDN between arteries and veins and between the ascending aorta and femoral artery. These concentration gradients may occur due to metabolism and accumulation of ISDN in many organs and tissues, let alone the vascular endothelium. There was no significant difference in plasma concentrations of ISDN or its metabolites between the hepatic vein and femoral vein. It seems that ISDN is metabolized in various organs and tissues. By ISDN infusion of more than 10 micrograms.kg-1.min-1, the plasma concentration of ISDN showed a pronounced increase. It appears that there is metabolic saturation of ISDN. Using these informations, we extrapolated the model to human and the estimated values were compared with observed values to determine the validity of the extrapolation model. There was no remarkable differences between the estimated values and observed values. This suggests the validity of the model. The plasma concentrations of ISDN, estimated by this extrapolated model, showed a linear increase (Y = 30X) with the flow rate range of 0.2-5.0 micrograms.kg-1.min-1, when the metabolic rate was normal. With ISDN infusion of more than 5.0 micrograms.kg-1.min-1, the plasma concentrations of ISDN showed a pronounced increase. In the conditions of impaired metabolism, the plasma concentrations of ISDN increase exponentially.(ABSTRACT TRUNCATED AT 250 WORDS)

Antimetastatic effect of yeast mannan-bleomycin conjugate against mouse Lewis lung carcinoma

A conjugate of bleomycin (BLM) and the mannan of bakers' yeast (Saccharomyces cerevisiae wild type strain) (WNM) was synthesized. The assay of its antimetastatic effect on Lewis lung carcinoma (3LL) implanted in C57BL/6 mice showed that this conjugate exhibited a higher antimetastatic effect and longer life-span elongation than those of free bleomycin and mannan with corresponding doses. This conjugate was also found to kill the 3LL cells in vitro. 14C-Labeled mannan-bleomycin conjugate was much more bound than 14C-labeled dextran-bleomycin conjugate to the 3LL. It was concluded that the anti-cancer mechanism of this conjugate, WNM-BLM possessed a specific binding effect to the tumor cells and exhibited a cytocidal effect on the 3LL target cells.

Comparative study on alpha 1-adrenoceptor antagonist binding in human prostate and aorta

1. Specific binding of [3H]-prazosin in prostatic and aortic membranes of humans was saturable and of high affinity (prostate: apparent dissociation constant, Kd = 0.35 +/- 0.03 nmol/L; aorta: Kd = 0.26 +/- 0.03 nmol/L). The density of [3H]-prazosin binding sites (Bmax) for prostate and aorta was 546 +/- 31 and 61.6 +/- 1.6 fmol/mg protein, respectively. 2. Prazosin, YM617, naftopidil and urapidil competed with [3H]-prazosin for the binding sites in a dose-dependent manner in the prostate and aorta of humans. The binding affinities of these antagonists in both tissues were compared, based on the inhibition constant, Ki. Both prazosin and urapidil showed similar affinity to [3H]-prazosin binding sites in human tissue, whereas YM617 and naftopidil showed approximately a 12 and two times higher affinity, respectively, to alpha 1-adrenoceptor sites of prostate than aorta. 3. The chloroethylclonidine treatment reduced partially the Bmax values for specific [3H]-prazosin binding in the prostate and aorta of humans with little effect on the Kd values. 4. These data suggest that YM617 is a relatively selective antagonist of human prostatic alpha 1-adrenoceptors.

A framework for the DNA-protein recognition code of the probe helix in transcription factors: the chemical and stereochemical rules

BACKGROUND

Understanding the general mechanisms of sequence specific DNA recognition by proteins is a major challenge in structural biology. The existence of a 'DNA recognition code' for proteins, by which certain amino acid residues on a protein surface confer specificity for certain DNA bases, has been the subject of much discussion. However, no simple code has yet been established.

RESULTS

The principles of DNA recognition can be described at two levels. The 'chemical' rules describe the partnerships between amino acid side chains and DNA bases making favourable interactions in the major groove of DNA. Here I analyze the occurrence of nucleotide-amino acid contacts in previously determined crystal structures of DNA-protein complexes and find that simple rules pertain. I also describe 'stereochemical' rules for the probe helix type of DNA-binding motif found in certain transcription factors including leucine zipper and homeodomain proteins. These are a consequence of the binding geometry, and specify the amino acid and base positions used for the contacts, and the sizes of residues in the contact interface.

CONCLUSIONS

The chemical rules can be generalized for any DNA-binding motif, while the stereochemical rules are specific to a particular DNA-binding motif. The recognition code for a particular binding motif can be described by combining the two sets of rules.

DNA polymerase alpha overcomes an error-prone pause site in the presence of replication protein-A

Eukaryotic DNA polymerase alpha pauses at some sites on the natural DNA template of M13mp2. Terminal misincorporations of dA or dG, in place of dT, by DNA polymerase alpha have been reported to be within one of the pause sites, pause site II (positions 6269 and 6270 (Fry, M., and Loeb, L.A. (1992) Proc. Natl. Acad. Sci. U.S.A. 89, 763-767)). The DNA products arrested within pause site II (position 6270) were separated, annealed with synthetic templates, and further elongated by DNA polymerase alpha. It was confirmed that a considerable amount of terminal misincorporation of dG in place of dT occurred at this position. When M13mp2 DNA was coated with various amounts of replication protein-A (RP-A), however, DNA polymerase alpha was able to overcome the pause site II, whereas pause bands at other sites barely decreased. In contrast, Escherichia coli single-stranded DNA-binding protein did not specifically abolish the arrested band at pause site II, though it generally suppressed the reaction. Since RP-A hardly increased the elongation frequency from the primer carrying a 3'-mismatched terminal deoxynucleotide, the reduction of arrested products by RP-A may be attributed to the change in the incorporation mode from noncomplementary to complementary deoxynucleotides within pause site II and may not be due to the reinitiation from the mismatched 3'-terminal deoxynucleotide. To confirm this, we amplified the reaction products at pause site III by means of a polymerase chain reaction method and showed that the complementary strand to pause site II, which was elongated in the presence of RP-A, did not carry any detectable misinsertion. Therefore, the errorprone step of the DNA synthesis catalyzed by DNA polymerase alpha may be readily avoided by RP-A.

Solution structure of the DNA binding octapeptide repeat of the K10 gene product

A putative transcription factor, the Drosophila K10 gene product, contains eight repeats of the octapeptide sequence SPNQQQHP or close variants. The solution structure of the K10 repeat was studied by NMR using a peptide composed of two SPNQQQHP units (referred to here as HP2). To overcome problems caused by degeneracy of backbone amide signals of Gln residues, a series of synthetic peptides containing an 15N-labelled main chain amide at different positions in HP2 were synthesized. In aqueous trifluoroethanol solution, HP2 folds into two structural units; the SPNQ part of each unit folds into a turn structure, while the C-terminal part shows some helical characteristics but is less structured. The N-terminal turn is likely to provide a core that produces a more stable helical structure upon binding to DNA and probably 'caps' the segmented helical unit at its N-terminus. This model is supported by a DNA footprinting study which shows that one SPNQQQHP unit spans four base pairs upon binding to A/T-rich sequences of DNA.

Structure elucidation of glykenin glycosidic antibiotics from Basidiomycetes sp. V. High-performance liquid chromatographic separation of components of glykenin

The glycosidic antibiotics of the glykenin (GK) family produced by Basidiomycetes sp. were separated into nine components (GK-I-VII and DG) by normal-phase chromatography. It was found that these components differ in the number and location of the acetyl groups in the sugar moiety. Each component (GK-I-VII and DG) was further separated into three isomers (A, B and C), which possess different aglycones, by reversed-phase chromatography on an ODS column with methanol-acetonitrile as eluent. The best composition of the eluent was found to be methanol-acetonitrile-1% trifluoroacetic acid (4:3.5:2.5). The profile analysis of GK-III-VII and DG was also carried out using a modified mobile phase. The combination of normal- and reversed-phase chromatography separated all components of the GK mixture except GK-I and II. The relationship between structure and separation behaviour of GK is discussed.

Glucagon increases intracellular free calcium in a distal tubular cell line

Glucagon (Glu) influences renal tubular function and growth, although the signal transduction of Glu in the kidney still remains obscure. Rabbit cortical tubules were transformed by the pSV-neo3 gene to make a homogeneous cell colony, which responded to vasopressin but not to parathyroid hormone. The [Ca2+]i of the cells at the 9-10th passages was measured by the fluorescence indicator, fura-2. The [Ca2+]i was increased by Glu (10(-8) M) or bradykinin (10(-8) M), between which heterologous desensitization was observed. The Glu range of 10(-14) to 10(-6) M) significantly increased [Ca2+]i, while cAMP was not produced at any dose of Glu. Since the ranges of doses were from physiological to pharmacological, two concentrations of 10(-13) and 10(-8) M were employed to investigate the mechanisms. Glu at 10(-13) M led to a sustained rise in [Ca2+]i, which was completely blocked by external EGTA (5 mM, Ca-free solution). Glu at 10(-8) M provided a similar level of peak and sustained rise in [Ca2+]i, the sustained phase of which was blunted in Ca-free solution. Inositol tri/tetra phosphates were significantly increased by 10(-8) M, but not by 10(-13) M Glu. These data suggest that [Ca2+]i elevation is a major component of Glu-induced second messengers in the physiological and pharmacological range of doses of Glu, and that there might be two classes of pathways leading to increase in [Ca2+]i in transformed rabbit cortical collecting tubule cells.

Alteration of immunoreactivity by hydrated autoclaving, microwave treatment, and simple heating of paraffin-embedded tissue sections

The effects of treatment in a hydrated autoclave (121 degrees C, 2 atm for 20 min), microwave oven (in water), and simple heating (60 degrees C overnight in distilled water or 90 degrees C for 10 min in ZnSO4) on the stainability of 56 antigens by commercially available antibodies in formalin-fixed paraffin-embedded tissue sections were evaluated. The detectability of nuclear antigens, glycoprotein, lymphocytic surface markers, and chromogranin A was significantly and reproducibly improved by these treatments, whereas the detectability of viral antigens and peptide hormones was attenuated or unchanged. This enhancement includes not only the distinctiveness of the positive staining, but also the number of positive cells, as revealed by comparing serial sections. Among these four heating procedures, microwave heating and autoclaving were more effective than the others on p53, c-erbB-2, and CA125, whereas simple heating was best for smooth-muscle actin (HHF35 and CGA7). Generally the effects of the heating procedures for these antigens were consistent among the cases, but the effects on GFAP varied with the case. The alterations we observed could significantly influence the interpretation of immunohistochemical staining of currently popular tumor markers such as p53 in terms of their prevalence (28% vs 64% in gastric cancer; 36% vs 82% in metastatic liver cancer) and other diagnostically important markers.

Polymerase chain reaction-single strand conformation polymorphism analysis of the p53 gene in paraffin-embedded surgical material from human renal cell carcinomas

p53 tumour suppressor gene mutations were studied in 118 renal cell carcinomas using paraffin-embedded surgical material. Optimal results were obtained with analysis of exon lengths between 150 and 200 base pairs for polymerase chain reaction. Single strand conformation polymorphism and sequencing analysis revealed only two point mutations (2/118, 2%): one involving codon 135; TGC-->TTC (cysteine-->phenylalanine) and the other codon 175; CGC-->CAC (arginine-->histidine). Both of these cases were classified as granular cell subtype on microscopic observation. The data suggest that the p53 tumour suppressor gene is not related to tumour initiation, promotion, or progression of renal cell carcinomas. However, there is the possibility that granular cell type carcinomas may have a different genetic background from clear cell type renal neoplasms.

Reconstitution of anti-tumor effects of lentinan in nude mice: roles of delayed-type hypersensitivity reaction triggered by CD4-positive T cell clone in the infiltration of effector cells into tumor

Lentinan, an antitumor polysaccharide used clinically in Japan, requires the intact T cell compartment to manifest its antitumor effects. The aim of the current study was to clarify the mechanisms playing crucial roles in the T cell requirement in the expression of antitumor effects of lentinan. Lentinan treatment of BDF1 mice transplanted intradermally with FBL-3 induced complete tumor regression and a marked increase in survival time. The antitumor action of lentinan was abolished in mice treated simultaneously with antibodies to CD4 and CD8 antigens, whereas antibody to CD4, CD8 or NK1.1 alone was ineffective. The natural killer, cytotoxic T lymphocyte, and helper T cell activities were already augmented in this FBL-3/BDF1 system and thus further augmentation of these activities by lentinan was not observed. These activities did not correlate with the antitumor activity of lentinan, as was confirmed in lymphocyte subset depletion experiments. On the contrary, the delayed-type hypersensitivity (DTH) response against tumor-associated antigens was triggered by lentinan and was abrogated only in mice treated simultaneously with antibodies to CD4 and CD8 antigens. Furthermore, a non-cytolytic tumor-associated antigen-specific CD4+ T cell clone able to induce the DTH response in concert with lentinan reconstituted the antitumor effects in B6 nude mice when administered with lentinan. These results suggest that, in addition to the augmentation of immune effector cell activity against tumors, infiltration of these cells into the tumor burden initiated by the DTH responses at tumor sites may be involved in eradication of tumors by lentinan.

Dietary polydextrose affects the large intestine in rats

We compared the effects of dietary polydextrose with those of dietary fibers on the luminal pH and morphology of the large intestine in rats. In Experiment 1, animals were fed diets supplemented with two levels (5 and 10 g/100 g) of polydextrose or dietary fiber (cellulose or galactomannan derivatives) for 52 d. Polydextrose and galactomannan derivatives significantly lowered large intestinal pH and increased the cecal weight and surface area compared with cellulose. However, the thickness of the cecal muscular layer was significantly less in the polydextrose-fed groups than in the cellulose-fed groups. In Experiment 2, rats were fed either a fiber-free diet or a diet containing 5, 10 or 20 g/100 g polydextrose for 92 d. Dietary polydextrose significantly acidified the cecal contents and promoted cecal mucosal growth but thinned the cecal muscular layer. The shape of colonic mucosa of the group fed the 20 g/100 g polydextrose diet was clearly different from that of the group fed the fiber-free diet. These findings indicate that the effect of polydextrose on the morphology of the large intestine is different from the effect of dietary fibers.

[Informed consent in anesthesia]

Informed consent is required for not only operative procedures but also anesthesia. One hundred and sixty-two patients, including those in a control group, were interviewed between the 3rd and 10th days after operations. An information sheet describes the anesthetic management and complications (possibilities of teeth damage, hoarseness and sore throat) in a simple style. This survey showed that those who had received the information sheet before operation showed significantly deeper understanding of anesthesia (56.2%) compared with those who had not received the information sheet (40.3%) (P < 0.05). The information sheet did not cause or increase anxiety about anesthesia. Those who had anxiety about anesthesia before the operation needed detailed printed information (63.8%) compared with those without anxiety (36.6%) (P < 0.01). An information sheet describing the anesthetic management and complications is useful for obtaining informed consent.

Investigation of type IIC von Willebrand disease

Type II von Willebrand disease (vWD) is characterized by qualitative abnormality of von Willebrand factor (vWF). It is characterized by the absence of the largest, or the largest and intermediate-size plasma vWF multimers. Type IIC vWD is a very rare variant subtype. We report the tenth case of type IIC vWD who is a 32-year-old Japanese with a history of lifelong mild bleeding problems. The multimeric analysis of vWF of the patient's plasma revealed that the multimers were composed of the increased smallest multimer and progressively decreased larger multimers, with each multimer replaced by a single band instead of a normal triplet structure. The family study highly suggested that the propositus is the first case of homozygote for type IIC vWD gene, although previous studies have suggested that type IIC vWD is due to double heterozygosity of two different mutant genes. The patient's von Willebrand factor antigen showed a slight response to 1-deamino-8-D-arginine vasopressin (DDAVP), whereas his ristocetin cofactor showed no response. The patient responded very well to an intermediate-purity factor VIII concentrate, and then underwent cholecystectomy without bleeding problems.

Multilobulated cystic formation in the brain stem with Benedikt's syndrome: case report

A 26-year-old man presented with an unusual multilobulated cystic formation in the brain stem with normal pressure hydrocephalus, followed by fluctuating cyst volume and Benedikt's syndrome. Ventriculoperitoneal shunting to relieve the hydrocephalus caused an increased cystic size, resulting in worsened neurological deficits. Cystectomy and an additional shunt resolved the symptoms. Immunohistochemical and electron microscopic examinations of the surgical specimen revealed no epithelial lining but numerous astrocytic processes on the luminal surface, probably resulting from expansion of the cyst. This case suggests that cystectomy before shunt emplacement is recommended in similar cases.

Enzymic synthesis of the trisaccharide core region of the carbohydrate chain of N-glycoprotein

Transmannosylation from mannotriose (Man beta 1-4Man beta 1-4Man) to the 4-position at the nonreducing end N-acetylglucosaminyl residue of N,N'-diacetylchitobiose was regioselectively induced through the use of beta-D-mannanase from Aspergillus niger. The enzyme formed the trisaccharide Man beta 1-4GlcNAc beta 1-4GlcNAc (3.7% of the enzyme-catalysed net decrease of N,N'-diacetylchitobiose) from mannotriose as a donor and N,N'-diacetylchitobiose as an acceptor. Mannobiose (Man beta 1-4Man) was also shown to be useful as a donor substrate for the desired trisaccharide synthesis.

Limited visual search on the WAIS Picture Completion test in patients with schizophrenia

The Wechsler Adult Intelligence Scale was examined in 39 patients with schizophrenia, the visual cognitive task of Picture Completion showing the most impairment. In order to clarify the role of eye movements in Picture Completion, searching eye movements in 12 schizophrenic patients and 12 normal controls were recorded using an infrared eye-mark recorder. Schizophrenic patients as a group showed fewer eye fixations, and shorter total length of scan path than normal controls during the last 10 s of exposure to the picture. However, the patients who responded correctly, did so with a similar number of fixations and similar length of total scan path to those of normal controls. The patients who failed in the task took a significantly longer time for the first survey of the picture than the successful patients and normal controls. The less efficient strategy of visual search seen in the patients who failed might be a manifestation of poor reality testing and be related to frontal lobe dysfunction.

[Response to a questionnaire on DNR-order from 307 trustee members of Japanese Medical Societies]

A questionnaire on the use of DNR-order was conducted on 427 trustee members of Japan Society of Reanimatology, Intensive Care Medicine and Anesthesiology with responses from 307 or 71.9%. The results of the questionnaire are as follows: DNR-order is unnecessary, 2.9%. Necessary depending on the situation, 96.7%. Here dying in dignity was the main reason for necessity of DNR-order and ethical, legal and technical problems were the reasons cited for objection. Patients' will is indispensable for DNR-order, 11.4%. Patients' will is not indispensable, 84.9%. Quality and quantity of treatment after the decision of DNR-order should not be limited or withdrawn, 21.2%. Should be withdrawn except for respirator, 60.6%. The percentage of those who had carried out a DNR-order was 69.1% (most of them more than once), but half of them did not describe the order on the chart. A guideline for a DNR-order by scientific societies and/or governmental policy for a DNR-order should be made and publicized not only for the benefit of the patients and their families but also for physicians themselves.

[Electromyographic study on the external urethral sphincter of the male--power spectrum analysis with fast Fourier transformation]

In 23 male patients, the electrical activity of external urethral sphincter muscle was sampled before examination of cystometry (Rest), at first desire to void (FDV), maximum desire to void (MDV) and during urination (Void) by means of electromyography (EMG). Sampling time of each event was 2400 msec. The electrical activity was amplified with a lower limiting frequency of 20 Hz and an upper limiting frequency of 10000 Hz, and recorded on magneto-optical desk. Spectra were obtained using a Hamming window. The action potential of the muscle was quantitatively analyzed and power spectrum of the needle EMGs were analyzed from the magneto-optical disk by a spectrum analyzer using fast Fourier transformation (FFT, Sande-Tukey method). From each power spectrum, mean power frequency (MPF) was obtained from a calculator connected to the spectrum analyzer. Twenty three patients were divided into three groups as follows: 8 patients without any neurological abnormality (normal group), 7 patients with neurogenic bladder showing detrusor-sphincter-dyssynergia (DSD+ group) and 8 patients with neurogenic bladder without detrusor-sphincter-dyssynergia (DSD- group). The results obtained were as follows: 1) The motor unit potentials at Rest had the mean amplitude of 210 +/- 59.4 microV, 329.3 +/- 157.1 microV and 177.6 +/- 132.8 microV in normal group, DSD+ group and DSD- group, respectively. The mean duration were 4.3 +/- 0.2 msec, 5.9 +/- 1.9 msec, and 7.3 +/- 4.5 msec., respectively. The mean phases were 2.8 +/- 0.6, 2.8 +/- 0.5 and 2.5 +/- 0.3, respectively. Statistically there was no difference in amplitude, duration and phase among three groups. 2) In normal group, the power over than -20 dB was distributed from 150 to 220 Hz windows at Rest and FDV. The needle EMGs at MDV showed interference pattern and the power increased over -20 dB in all windows. The power of high frequency area relatively increased. The action potential of the muscle disappeared during urination and the power also disappeared. The average MPF was 103 Hz, 102 Hz, 150 Hz and 98 Hz at Rest, FDV, MDV and Void, respectively. 3) In DSD+ group, the needle EMGs showed interference pattern in MDV and Void, and the power increased only in low frequency area. The average MPF was 104 Hz, 105 Hz, 114 Hz and 120 Hz at Rest, FDV, MDV and Void, respectively. 4) Because of damage to nerves, the action potential of the muscle was difficult to obtain from 3 patients of DSD- group, and the power was not demonstrated.(ABSTRACT TRUNCATED AT 400 WORDS)

Piperazinealkanol ester derivatives of indomethacin as dual inhibitors of 5-lipoxygenase and cyclooxygenase

Piperazinealkanol ester derivatives of indomethacin were prepared and tested for inhibitory activities against 5-lipoxygenase (5-LO) and cyclooxygenase (CO). They inhibited 5-hydroxyeicosatetraenoic acid (5-HETE) formation by the cytosol of guinea pig polymorphonuclear leukocytes and thromboxane B2 (TXB2) formation by washed rabbit platelet suspension. Of the test compounds, 2-[4-(2-hydroxyethyl)-1-piperazinyl]-1-phenylethyl 1-(4-chlorobenzoyl)-5-methoxy-2-methyl-3-indolylacetate dimaleate (II-8) was found to be the most active dual inhibitor of 5-LO and CO, and its inhibitory potency was higher than that of 2-[4-(3-hydroxypropyl)-1-piperazinyl]-ethyl [1-(4-chlorobenzoyl)-5-methoxy-2-methyl]-3-indolyacetate (CR-1015) (I), the lead compound.