Improving cell-specific recombination using AAV vectors in the murine CNS by capsid and expression cassette optimization

The production of cell-type- and age-specific genetically modified mice is a powerful approach for unraveling unknown gene functions. Here, we present a simple and timesaving method that enables adeno-associated virus (AAV)-mediated cell-type- and age-specific recombination in floxed mice. To achieve astrocyte-specific recombination in floxed Ai14 reporter mice, we intravenously injected blood-brain barrier-penetrating AAV-PHP.eB vectors expressing Cre recombinase (Cre) using the astrocyte-specific mouse glial fibrillary acidic protein (mGfaABC1D) promoter. However, we observed nonspecific neuron-predominant transduction despite the use of an astrocyte-specific promoter. We speculated that subtle but continuous Cre expression in nonastrocytic cells triggers recombination, and that excess production of Cre in astrocytes inhibits recombination by forming Cre-DNA aggregates. Here, we resolved this paradoxical event by dividing a single AAV into two mGfaABC1D-promoter-driven AAV vectors, one expressing codon-optimized flippase (FlpO) and another expressing flippase recognition target-flanked rapidly degrading Cre (dCre), together with switching the neuron-tropic PHP.eB capsid to astrocyte-tropic AAV-F. Moreover, we found that the FlpO-dCre system with a target cell-tropic capsid can also function in neuron-targeting recombination in floxed mice.

Protein kinase Cγ negatively regulates the intrinsic excitability in zebrin-negative cerebellar Purkinje cells

Protein kinase C γ (PKCγ), a neuronal isoform present exclusively in the central nervous system, is most abundantly expressed in cerebellar Purkinje cells (PCs). Targeted deletion of PKCγ causes a climbing fiber synapse elimination in developing PCs and motor deficit. However, physiological roles of PKCγ in adult mouse PCs are little understood. In this study, we aimed to unravel the roles of PKCγ in mature mouse PCs by deleting PKCγ from adult mouse PCs of PKCγfl/fl mice via cerebellar injection of adeno-associated virus (AAV) vectors expressing Cre recombinase under the control of the PC-specific L7-6 promoter. Whole cell patch-clamp recording of PCs showed higher intrinsic excitability in PCs virally lacking PKCγ [PKCγ-conditional knockout (PKCγ-cKO) PCs] than in wild-type (WT) mouse PCs in the zebrin-negative module, but not in the zebrin-positive module. AAV-mediated PKCγ re-expression in PKCγ-deficient mouse PCs in the zebrin-negative module restored the enhanced intrinsic excitability to a level comparable to that of wild-type mouse PCs. In parallel with higher intrinsic excitability, we found larger hyperpolarization-activated cyclic nucleotide-gated (HCN) channel currents in PKCγ-cKO PCs located in the zebrin-negative module, compared with those in WT mouse PCs in the same region. However, pharmacological inhibition of the HCN currents did not restore the enhanced intrinsic excitability in PKCγ-cKO PCs in the zebrin-negative module. These results suggested that PKCγ suppresses the intrinsic excitability in zebrin-negative PCs, which is likely independent of the HCN current inhibition.

Acotiamide Hydrochloride, a Therapeutic Agent for Functional Dyspepsia, Enhances Acetylcholine-induced Contraction via Inhibition of Acetylcholinesterase Activity in Circular Muscle Strips of Guinea Pig Stomach

Acotiamide is a first-in-class prokinetic drug approved in Japan for the treatment of functional dyspepsia. Given that acotiamide enhances gastric motility in conscious dogs and rats, we assessed the in vitro effects of this drug on the contraction of guinea pig stomach strips and on acetylcholinesterase (AChE) activity in stomach homogenate following fundus removal. We also investigated the serotonin 5-HT4 receptor agonist mosapride, dopamine D2 receptor and AChE inhibitor itopride, and representative AChE inhibitor neostigmine. Acotiamide (0.3 and 1 μM) and itopride (1 and 3 μM) significantly enhanced the contraction of gastric body strips induced by electrical field stimulation (EFS), but mosapride (1 and 10 μM) did not. Acotiamide and itopride significantly enhanced the contraction of gastric body and antrum strips induced by acetylcholine (ACh), but not that induced by carbachol (CCh). Neostigmine also significantly enhanced the contraction of gastric body strips induced by ACh, but not that by CCh. In contrast, mosapride failed to enhance contractions induced by either ACh or CCh in gastric antrum strips. Acotiamide exerted mixed inhibition of AChE, and the percentage inhibition of acotiamide (100 μM) against AChE activity was markedly reduced after the reaction mixture was dialyzed. In contrast, itopride exerted noncompetitive inhibition on AChE activity. These results indicate that acotiamide enhances ACh-dependent contraction in gastric strips of guinea pigs via the inhibition of AChE activity, and that it exerts mixed and reversible inhibition of AChE derived from guinea pig stomach.

Acotiamide, a new orally active acetylcholinesterase inhibitor, stimulates gastrointestinal motor activity in conscious dogs

BACKGROUND Acotiamide hydrochloride (acotiamide), a novel selective acetylcholinesterase (AChE) inhibitor, has proven significantly effective in treating functional dyspepsia (FD) in clinical trials, particularly in alleviating meal-related symptoms. In the present study, we examined the gastrointestinal prokinetic effects of acotiamide administered orally or intraduodenally in conscious dogs and investigated in vivo and ex vivo anti-AChE activity of acotiamide to clarify its mechanism of prokinetic action.

METHODS

Gastrointestinal motility was measured in conscious dogs with chronically implanted force transducers.

KEY RESULTS

Oral administration of acotiamide stimulated postprandial gastroduodenal and colonic motor activities. Measurement of gastrointestinal motility showed that acotiamide, like itopride and mosapride, enhanced gastric antral motility. Further, acotiamide markedly improved clonidine (an α(2) -adrenoceptor agonist)-induced hypomotility in a dog model of gastric motor dysfunction. The postprandial gastric antral motility enhanced by acotiamide was completely abolished on treatment with the muscarinic receptor antagonist atropine. Results of an in vivo experiment on anti-AChE activity showed clearly increased acetylcholine-induced gastric motility on intraduodenal administration of acotiamide, just as observed with the AChE inhibitor neostigmine. Further, in ex vivo experiment, intraduodenal administration of acotiamide significantly inhibited AChE activity in canine gastric antrum.

CONCLUSIONS & INFERENCES

Our findings revealed that acotiamide administered through the alimentary tract exerts gastroprokinetic action via cholinergic pathways by inhibiting AChE activity. These results may also confirm the mechanism of action in clinical efficacy of acotiamide on FD.

Oligoclonal expansion of circulating and tissue-infiltrating CD8+ T cells with killer/effector phenotypes in juvenile dermatomyositis syndrome

Although triggering by infectious agents and abnormal immune responses may play some role in the pathogenesis of juvenile dermatomyositis syndrome (JDMS), the precise mechanism of muscle destruction and vascular damage is largely unknown. In this study, we tried to elucidate the role of cytotoxic T cells in two patients with JDMS, who were diagnosed based on the characteristic symptoms, laboratory data, MRI findings and electromyographic patterns. Peripheral blood T cell phenotypes were determined by flow cytometry, using mAbs against specific T cell receptor (TCR) Vbetas. Complementarity-determining region3 (CDR3) size analysis was performed by gene scanning of CDR3 polymerase chain reaction (PCR) amplification products specific for each Vbeta. Subsequently, CDR3 nucleotide sequences were obtained after cloning of the predominant products. The distribution of lymphocytes infiltrating the muscle tissue was analysed by immunohistochemistry. In both patients examined, a unique combination of TCR Vbeta repertoires was increased within the CD8+ T cells. These subpopulations expressed a characteristic phenotype, indicating that they are memory/effector T cells with killer functions. At the same time, immunohistological and molecular biological examinations of the biopsied muscle samples revealed that identical CD8+ T cell clones with identical phenotypes/TCR Vbeta infiltrated within the inflammatory tissue, in particular around vessels. These findings indicate that oligoclonal expansion of CD8+ T cells plays a central role in the pathogenesis of muscle injury in the juvenile form of dermatomyositis syndrome and may provide a useful clinical parameter of disease activity and responsiveness to anti-inflammatory therapy.

Collaborative work to evaluate toxicity on male reproductive organs by repeated dose studies in rats 10). Testicular toxicity of adriamycin observed 2 and 4 weeks after a single intravenous administration

The present study was performed to clarify whether toxic effects of the antitumor drug, adriamycin (ADR) on the male genital organ can be adequately detected 2 and 4 weeks after a single intravenous administration in the rat. ADR was intravenously administered once to 10 Crj:CD (SD) male rats/group aged 6 weeks (4-week group) and 8 weeks (2-week group) at doses of 0, 2 and 6 mg/kg. The rats were sacrificed at the age of 10 weeks. For comparison 10 rats/group were killed 2 weeks after a single intravenous administration at the age of 4 weeks (immature group). Saline was administered to control rats. Histopathological examination and a quantitative morphometry were carried out after measurement of testes weights at necropsy. In rats of the 4-week and 2-week groups, mean absolute testicular weight in all groups was significantly decreased. However, changes in mean relative weight were not evident in the 2-week group. Disappearance of seminiferous epithelial cells was observed histopathologically in rats dosed with 2 and 6 mg/kg in the 2-week group. The change was more severe in the 4-week group, when reduction of spermatogenesis and giant cells were also observed at 6 mg/kg. The quantitative morphometry in the 2-week group showed decreases in the numbers of spermatogonia and spermatocytes in stages X and XII at 2 mg/kg, and in the numbers of spermatogonia in all stages and spermatocytes in all stages except stage V at 6 mg/kg. Moreover, the numbers of spermatogonia and spermatocytes in all stages and spermatids in stages II-III and V were decreased with dose related manner in the 4-week group. In contrast, no obvious change in testes weights was apparent in the immature group. However, the numbers of spermatogonia and spermatocytes in all stages were decreased at 6 mg/kg. In conclusion, testicular toxicity of ADR could be detected 2 weeks after a single administration. Susceptibility of the testes of immature rats to ADR might be less than that of older animals.

Effect of repeated local minocycline administration on periodontal healing following guided tissue regeneration

BACKGROUND

Infection after a periodontal surgical site has been prepared for guided tissue regeneration (GTR) is one of the common complications that can compromise healing. The purpose of this study was to assess the effect of repeated local antimicrobial therapy following GTR for improving clinical attachment gains, and to histologically evaluate the various cell populations and bacterial contamination of the retrieved expanded polytetrafluoroethylene membrane (ePTFE).

METHODS

Forty periodontal intrabony defects in 40 patients were treated by a flap procedure that included the use of ePTFE membranes to allow GTR. Patients were randomly assigned to 2 treatment groups: 20 patients were treated with the ePTFE alone (control group), and the other 20 were treated with the ePTFE combined with the administration of a weekly repeated local application of minocycline ointment for 8 weeks after membrane placement (test group). The membranes were retrieved 6 weeks after the initial surgery and sectioned serially in a coronal-apical plane. The sections were then divided into 9 fields and examined by light microscopy for the presence of inflammatory cells and oral bacteria. Clinical measurements were taken at the time of baseline examination and at a 6-month follow-up examination after removal of the ePTFE.

RESULTS

At the 6-month follow-up examination, control and test groups showed significant improvement; i.e., reduction in the probing depth and increased clinical attachment gain compared with the values at the baseline examination. However, the mean clinical attachment gain of the test group (3.0+/-0.3 mm) was significantly (P = 0.03) greater than that of the control group (2.0+/-0.5 mm). Histologically, the total number of the cells of both groups was similar. In both groups, mononuclear cells were dominant and fibroblasts, neutrophils, and plasma cells were rarely encountered. There was a tendency for the number of macrophages to be somewhat higher in the control group. The total number of bacteria in the test group was significantly less than that in the control group. The number of bacteria in both control and test groups decreased toward the apical portion.

CONCLUSIONS

In the present study, clinical attachment gain of intrabony defects following GTR was favorable with repeated local administration of minocycline ointment. However, a complete microbial eradication was not achieved.

Expressions of vascular endothelial growth factor and basic fibroblast growth factor in tumors induced by two different cloned cell lines established from transplantable rat malignant fibrous histiocytoma

In order to establish base-line data on angiogenic factors in development of mesenchymal tumors, expressions of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in implanted MT-8 and MT-9 tumors, both derived from a transplantable malignant fibrous histiocytoma (MFH) in the F344 rat, were investigated by immunohistochemistry and Western blotting method. MT-8 and MT-9 tumors were developed in syngeneic rats by implant of a tumor tissue fragment. MT-8 tumors were examined on post-implantation (PI) days 3, 6, 9 and 17, and MT-9 tumors were on PI days 9, 14, 17 and 23. The growth of MT-8 tumors was faster than that of MT-9 tumors. Histologically, MT-8 tumors were features of undifferentiated sarcomas, whereas MT-9 tumors exhibited a typical storiform growth pattern of MFH. Immunohistochemically, all cells constituting MT-8 and MT-9 tumors reacted with antibodies to VEGF and bFGF, indicating production of these factors by mesenchymal neoplastic cells. However, there were no marked differences in these immunoreactions between tumors examined. Thus, the bands obtained in the Western blotting methods were densitometrically scanned. The expression levels of VEGF and bFGF gradually increased PI day 3 to 9 in MT-8 tumors and PI day 9 to 17 in MT-9 tumors. On last examination day, the levels of bFGF in both tumors and of VEGF in MT-9 tumors decreased, but the VEGF expression level in MT-8 tumors was still increased. These findings indicated that VEGF and bFGF may contribute cooperatively to angiogenesis in an early growth of mesenchymal tumor development.

Phylogenetic analysis of the SSU rRNA from members of the Chrysophyceae

The nucleotide sequence for the nuclear-encoded small subunit ribosomal RNA gene (SSU rRNA) was determined for 24 species of the Chrysophyceae sensu stricto. These sequences were aligned, using primary and secondary structure, with nine previously published sequences for the Chrysophyceae, 14 for the Synurophyceae, and five for the Eustigmatophyceae (outgroup). Data analyses were the substitution rate calibration distance method using neighbor-joining (TREECON), Kimura 2-parameter neighbor-joining method (PAUP) and the maximum parsimony method (PAUP, PHYLIP). Trees from the analyses were largely congruent, but bootstrap support was weak at many nodes. The analyses recovered clades of uniflagellate and biflagellate organisms associated with current higher level taxonomy (e.g., subclass, order). The genus Ochromonas was polyphyletic, and O. tuberculata in particular was distantly related to the other Ochromonas species in the analysis. The family Paraphysomonadaceae occupied a basal position in three of four analyses. The class Synurophyceae appeared to be embedded within the Chrysophyceae, but bootstrap support was weak (< 50%) in all analyses except the PHYLIP parsimony analysis (= 81%). It was considered premature to place the Synurophyceae back into the Chrysophyceae based upon the analysis of one gene, especially given the ultrastructural and pigment differences between the two groups, but the relationship of these two groups deserves further study.

Insulin-like growth factor (IGF) system components in human prostatic cancer cell-lines: LNCaP, DU145, and PC-3 cells

BACKGROUND

Evidence has been accumulating that in many tumors, insulin-like growth factors (IGFs) promote cancer cell growth in an autocrine/paracrine manner via the IGF-I receptor. In an effort to understand the role of IGFs in prostate cancer cell growth, we characterized the IGF system components produced by human prostatic cancer cell-lines, LNCaP, DU145, and PC-3, grown in serum-free medium.

METHODS

IGFs, their receptors, and IGF binding proteins (IGFBPs) produced by the three human prostate cell lines were characterized by reverse transcriptase-polymerase chain reaction (RT-PCR), radioimmunoassay (RIA), Western ligand blot, Western immunoblot, and Northern blot analyses.

RESULTS

mRNA for IGF-II and receptors for IGF-I and IGF-II were detected in all three cell-lines by RT-PCR. In contrast to the published study, only LNCaP cells expressed a trace amount of IGF-I mRNA. RIA on conditioned media collected from these cells revealed that all three cell-lines produced measurable IGF-II but not IGF-I. Western Ligand blot, Western immunoblot, and Northern blot analyses revealed that LNCaP, DU145, and PC-3 cells expressed IGFBP-2, IGFBP-2/-3/-4/-6, and IGFBP-2/-3/-4/-5/-6, respectively. IGF-II stimulated [3H]thymidine incorporation into DNA in DU145 and PC-3 cells significantly although the effect was small. DNA synthesis in PC-3 cells but not in LNCaP and DU145 cells was significantly inhibited by the IGF-I receptor-specific monoclonal antibody.

CONCLUSION

Theses results suggest potentially important roles of IGFs and IGFBPs in prostate cancer cell growth, and that in particular, IGF-II may play a critical role in prostate cancer cell growth.

Postradical orchiectomy hemorrhage: should an alteration in staging strategy for testicular cancer be considered?

We report 3 cases of postradical orchiectomy hemorrhage from separate institutions. The retroperitoneal and pelvic hematoma formed as a complication of orchiectomy can be misinterpreted to represent metastatic disease on postoperative staging computed tomography scans. As a result of inaccurate information obtained from these evaluations, significant alterations in patient management will result. Prevention and early recognition of this complication are crucial if unnecessary treatment is to be avoided.

Influence of daily drinking habits on ethanol-induced hyperuricemia

We examined the influence of alcohol drinking habits on the serum uric acid level after the ingestion of a small amount of ethanol. Subjects were divided into two groups according to their alcohol drinking habits--regular drinkers, who consume more than 60 g ethanol every day, and nondrinkers/occasional drinkers, who consume less than 20 g ethanol occasionally. Drinking 0.5 g ethanol/kg increased serum uric acid levels in regular drinkers by 52.6 +/- 26.3 mumol/L (0.8 +/- 0.4 mg/dL), whereas it did not in nondrinkers/occasional drinkers. Urinary excretion of uric acid was unaltered in both groups. Hypoxanthine and xanthine in both plasma and urine and serum acetate were increased more in regular drinkers than in nondrinkers/occasional drinkers. Accelerated adenine nucleotide degradation secondary to enhanced ethanol oxidation likely explains the ethanol-induced hyperuricemia in regular drinkers.

Photosensitivity in Ge-doped silica optical waveguides and fibers with 193-nm light from an ArF excimer laser

Photosensitivity in optical fibers and waveguides has been associated with the bleaching of an absorption band located near 5.0 eV (or 242 nm). We present new results for Bragg grating formation and UV bleaching experiments carried out using 193-nm light from an ArF excimer laser instead of the usual laser sources operating near 242 or 248 nm.

The gene for ribosomal protein L27 is located on the plastid rather than the nuclear genome of the chlorophyll c-containing alga Pleurochrysis carterae

The gene for ribosomal protein L27 (rpl27) has not been found in plastid genomes. We report here that the rpl27 gene is located in the plastid genome of the prymnesiophyte Pleurochrysis carterae. The deduced amino acid sequence showed 59% identity with E. coli L27. 1.0 kb transcript of the gene was detected by Northern blot analysis. Nucleotide sequence analysis of PCR products suggested that rpl27 is widespread in the genomes of Prymesiophyta and Rhodophyta. In all species of Prymnesiophyta examined in this study, the gene is located at the 3' downstream region of Rubisco operon.

Photosensitization of optical fiber and silica-on-silicon/silica waveguides

Localized heating with a flame is shown to be a simple and effective method for substantially augmenting the photosensitivity of high-silica optical waveguides to (UV) light. The method increases the photosensitivity of standard (Ge-doped core) telecommunications fiber by a factor greater than 10 (photoinduced Deltan(uv) > 10(-3)) and renders strongly photosensitive the cores of high-quality Ge:SiO(2)-on-Si and Ge:SiO(2)-on-SiO(2) planar waveguides that were negligibly photosensitive before treatment. We have written large-modulation-depth Bragg gratings, in both fiber and planar optical waveguides photosensitized by our method, using KrF (249-nm) radiation incident upon the waveguides through a zero-order-nulled phase mask. It is noteworthy that photosensitization by our method is achieved with a negligible increase in loss at the three principal optical communication windows.

Glycogenosis type V (McArdle's disease) with hyperuricemia. A case report and clinical investigation

A 28-year-old male with glycogenosis type V associated with continuous hyperuricemia during mild daily activities is reported. An aerobic exercise test using a bicycle ergometer revealed that purine metabolites, i.e., ammonia, inosine, hypoxanthine and xanthine, were transiently increased by the exercise and that a subsequent increment in uric acid continued until the following day. The accelerated purine degradation by the muscle exercise was thus shown to be able to cause the overt hyperuricemia in a patient with glycogenosis type V. Therapeutic use of fructose for glycogenosis was disappointing due to fructose-induced hyperuricemia. A search for myogenic hyperuricemia is essential for therapeutic trials.

Decreased renal clearance of xanthine and hypoxanthine in a patient with renal hypouricemia: a new defect in renal handling of purines

Renal handling of urate, xanthine and hypoxanthine was studied in a hypouricemic patient who had increased plasma concentrations of xanthine and hypoxanthine. The patient, a 50-year-old man, had been suffering from Parkinson's disease, while neither systemic disorders nor particular renal diseases known to affect plasma purine levels were found. His serum urate level was 58 +/- 6 mumol/l (healthy controls for males, 310 +/- 48 mumol/l, mean +/- SD) and the renal uric acid clearance was 3 times higher than that of the controls, establishing a diagnosis of renal hypouricemia. Xanthine and hypoxanthine concentrations in the plasma were elevated to 1.3 +/- 0.1 mumol/l (controls, 0.5 +/- 0.3) and 5.9 +/- 3.5 mumol/l (controls, 1.6 +/- 0.4), respectively. Both renal xanthine and hypoxanthine clearance was only half the value of the controls, indicating reduced urinary excretion of xanthine, and hypoxanthine appears to be responsible for their elevation in plasma. A probenecid loading test revealed no response of urinary urate excretion but normal responses of xanthine and hypoxanthine excretion. However, urinary excretion of urate, xanthine or hypoxanthine did not respond at all to pyrazinamide administration. These findings indicate that the patient had a defective renal handling of xanthine and hypoxanthine as well as urate.

Low glucose-1, 6-bisphosphate and high fructose-2, 6-bisphosphate concentrations in muscles of patients with glycogenosis types VII and V

The level of glucose-1, 6-bisphosphate, a potent allosteric activator of phosphofructokinase, was markedly decreased in muscles of patients with glycogenosis type VII (muscle phosphofructokinase deficiency) and type V (muscle phosphorylase deficiency). Glucose-1-phosphate kinase activity in muscle was virtually absent in a patient with glycogenosis type VII, whereas it was normal in a patient with type V glycogenosis. Glucose-1-phosphate level was increased in type VII glycogenosis, whereas it was decreased in type V glycogenosis. Another activator of phosphofructokinase, fructose-2, 6-bisphosphate was increased in muscles of patients with both types of glycogenosis although it was much higher in type VII than in type V. This finding may be partly related to the difference of fructose-6-phosphate concentrations. The results suggest that phosphofructokinase would contribute to the major glucose-1-phosphate kinase activity in normal human muscle and would also form a kind of self-activating system.

Grating axicon for collimating Cerenkov radiation waves

An axicon optical element that utilizes a diffraction grating has been fabricated for collimating the Cerenkov radiation wave. The grating axicon has the advantage of a simple structure, which can easily be fabricated by the computerized numerical control machining technique. The collimation function of the grating axicon is confirmed for Cerenkov-type second-harmonic generation in LiNbO(3) waveguides, and correction of the aberration caused by substrate anisotropy is investigated. The aberration can be compensated by appropriately inclining either the substrate facet or the grating axicon.

Glucose infusion abolishes the excessive ATP degradation in working muscles of a patient with McArdle's disease

A 23-year-old woman with McArdle's disease performed mild leg exercise on a bicycle ergometer. Saline or 10% glucose solution was infused throughout exercise. After exercise with saline infusion, her plasma concentrations of ammonia, hypoxanthine and creatine kinase increased greatly. Conversely, after exercise with glucose infusion, there were no appreciable changes in these plasma substances. In addition, she noticed that glucose infusion relieved her from muscle symptoms during exercise. These findings suggest that glucose infusion to patients with McArdle's disease ameliorates excessive ATP degradation in exercising muscles.

Genetic defect in muscle phosphofructokinase deficiency. Abnormal splicing of the muscle phosphofructokinase gene due to a point mutation at the 5'-splice site

The genetic defect in muscle phosphofructokinase deficiency (type VII glycogenosis, Tarui disease) was investigated. Six cDNAs for muscle phosphofructokinase, including a full-length clone, were isolated from a non-amplified library of muscle from a patient. By sequence analysis of these clones, a 75-base in-frame deletion was identified. The rest of the sequence was identical to that of the normal cDNA, except for a silent base transition at position 516 (ACT (Thr) to ACC (Thr]. The deletion was located in the 3'-terminal region of exon 13 (numbered with reference to the rabbit muscle phosphofructokinase gene (Lee, C.-P., Kao, M.-C., French, B.A., Putney, S.D., and Chang, S.H. (1987) J. Biol. Chem. 262, 4195-4199]. Genomic DNA of the patient was amplified by polymerase chain reaction. Sequence analysis of the amplified DNA revealed a point mutation from G to T at the 5'-end of intron 13. This mutation changed the normal 5'-splice site of CAG:GTATGG to CAG:TTATGG. A cryptic splice site of ACT:GTGAGG located 75 bases upstream from the normal splice site was recognized and spliced in the patient.

Asymptomatic hereditary xanthinuria: a case report

A 22-year-old man with hereditary xanthinuria is reported. A biochemical study of the patient showed elevated serum levels of xanthine and hypoxanthine with concomitant increases in urinary excretion of xanthine and hypoxanthine. The xanthine oxidase activity in the duodenal mucosa of the patient was about 1.5% of normal value. Urinary excretion of xanthine and hypoxanthine of his parents and his eldest brother were significantly higher than the corresponding normal values, but the values were much less than those of the patient. The results suggested that the patient was homozygote, and his parents and his eldest brother were heterozygotes.

Decreased xanthine oxidase activities and increased urinary oxypurines in heterozygotes for hereditary xanthinuria

Two brothers with hereditary xanthinuria (xanthine oxidase deficiency) and several members of their family were studied. In both subjects, plasma and urinary concentrations of uric acid were low whereas xanthine and hypoxanthine concentrations were markedly elevated. Xanthine oxidase activity was virtually absent in the patients' duodenal mucosa, a finding that established the diagnosis of hereditary xanthinuria. In their parents (obligate heterozygotes), the duodenal xanthine oxidase activity was about 50% of that in control subjects (father 9.3 and mother 12.8 mU/g tissue compared with 21.3 +/- 5.0 mU/g tissue, mean +/- SD). The residual xanthine oxidase from the parents exhibited normal kinetics with respect to hypoxanthine. The parents' urinary xanthine and hypoxanthine concentrations were significantly greater than those of control subjects, while their plasma concentrations of oxypurines were normal. Similar findings were observed in at least 6 other relatives, a finding that suggested that they were heterozygotes. This study suggests that obligate hereditary xanthinuria heterozygotes have only 50% of the xanthine oxidase activity of controls; this deficiency results in a partial metabolic blockage at this enzymatic step in heterozygotes.

Hyperinsulinemia due to impaired insulin clearance associated with fasting hypoglycemia and postprandial hyperglycemia: an analysis of a patient with antiinsulin receptor antibodies

Antiinsulin receptor antibodies were detected in the serum of a patient with insulin-resistant diabetes. Fasting hypoglycemia and postprandial hyperglycemia recurred every day. The plasma insulin level was 553 +/- 359 pmol/L [77 +/- 50 microU/mL (mean +/- SD)] in the fasting state and rose above 7500 pmol/L postprandially. The glycemic clamp at 2.8 mmol/L (50 mg/dL) without insulin infusion revealed that the half-life of plasma endogenous insulin was 173 min, indicating severely impaired plasma insulin clearance. During the clamp the glucose infusion rate was almost constant (0.9-1.2 mg/kg.min) despite an exponential decline in the plasma insulin level from 460 pmol/L (65 microU/mL) to 129 pmol/L (18 microU/mL). Intravenous insulin administration did not appreciably accelerate the basal constant decrease in the plasma glucose level during the postabsorptive period. These results indicate the coexistence of marked insulin resistance and constant ability to decrease plasma glucose level. In in vitro experiments, antireceptor immunoglobulin G from this patient increased the fructose 2,6-bisphosphate concentration in the presence of glucagon (less than 0.1 nmol/L) in primary cultured rat hepatocytes. The antireceptor immunoglobulin G stimulated autophosphorylation of rat liver insulin receptor. We conclude that antiinsulin receptor antibodies could impair plasma insulin clearance, resulting in persistent hyperinsulinemia, and that continuous receptor stimulation by the antibodies was responsible for the development of hypoglycemia.

Metabolism of pyrazinamide and allopurinol in hereditary xanthine oxidase deficiency

The metabolism of pyrazinamide and allopurinol was studied in three xanthinuric patients from two families with hereditary xanthinuria to determine whether both substrates were oxidized only by xanthine oxidase or by other oxidases as well. One xanthinuric patient could neither metabolize pyrazinamide into 5-hydroxypyrazinamide nor allopurinol into oxypurinol. Two xanthinuric patients could metabolize both pyrazinamide into 5-hydroxypyrazinamide and allopurinol into oxypurinol but could not oxidize pyrazinoic acid to 5-hydroxypyrazinoic acid. These findings suggest that xanthinuria comprises at least two subgroups.

Autoantibodies to the insulin receptor impair clearance of plasma endogenous insulin

Plasma insulin clearance was studied in a patient with autoantibodies to the insulin receptor, manifesting persistent hyperinsulinemia associated with alternating hyper- and hypoglycemia. In the postabsorptive period, the plasma glucose level gradually decreased. To prevent the development of hypoglycemia, glucose was infused and the glycemic level was clamped at 50 mg/dl without insulin infusion. The plasma C-peptide level was below the detectable range during the clamp, indicating no appreciable secretion of insulin. The plasma insulin level declined exponentially with a markedly prolonged disappearance rate (half-time: 3.0 h) during the study. These results indicate that hyperinsulinemia in the postabsorptive period in this patient is attributable to the impairment of plasma insulin clearance through receptor-mediated mechanisms, and also confirm that the receptor plays the principal role in plasma insulin removal.

Increases in hepatic fructose-2,6-bisphosphate level and fructose-6-phosphate,2-kinase activity in rats with ventromedial lesions of the hypothalamus

To investigate altered fructose-2,6-bisphosphate (fructose-2,6-P2) metabolism, we measured fructose-2,6-P2 levels and fructose-6-phosphate,2-kinase (fructose-6-P,2-kinase) activities in various tissues, including liver, kidney, heart, and skeletal muscle, of ventromedial hypothalamus (VMH)-lesioned rats during feeding and starvation. The plasma insulin level was 6 times or more higher in these rats than in the controls. The fructose-2,6-P2 level in liver was much greater in VMH-lesioned rats than in the controls: 15.1 +/- 2.2 nmol/g tissue versus 7.7 +/- 0.7 in the fed state, 5.3 +/- 1.1 versus 1.6 +/- 0.4 in the starved state. In kidney, heart, and skeletal muscle, fructose-2,6-P2 levels were not different between the two animal groups. The activity of hepatic fructose-6-P,2-kinase remained high after 20 h of starvation in VMH-lesioned rats, whereas it was decreased markedly in the controls. The hepatic concentration of fructose-6-phosphate was also high in VMH-lesioned rats. Both fructose-6-P,2-kinase activity and fructose-6-phosphate concentration in the liver of starved VMH-lesioned rats were comparable to those of control rats in fed conditions. These results indicate that the alteration of fructose-2,6-P2 metabolism is characteristic of liver in VMH-lesioned rats, and that the increase in hepatic fructose-2,6-P2 may activate hepatic glycolysis not only during feeding but also during starvation, leading to the enhanced lipogenesis in these obese rats.

Exaggerated insulin secretory response in patients with insulinomas to midaglizole, a drug with alpha 2-adrenergic blocking activity

Midaglizole is a new alpha 2-adrenergic blocking agent which increases insulin release from normal pancreatic islets. We studied its effect in four patients with insulinomas. In three patients oral administration of 150 mg of midaglizole caused a large increase in serum insulin and a corresponding decrease in plasma glucose. The magnitude of the response cannot exclude the possibility that midaglizole has direct beta cell stimulatory activity. Two of the three patients had operations, and their insulin responses to midaglizole became normal after removing the tumours. In contrast, midaglizole did not stimulate insulin secretion in the fourth patient. A midaglizole stimulation test might be useful in screening patients with insulinomas.

Inosine and adenosine formation in ischemic and non-ischemic contracting muscles of rats: difference between fast and slow muscles

Inosine and adenosine formation was evaluated in different types of rat skeletal muscle during ischemic and non-ischemic contraction. Extensor digitorum longus (EDL, fast) and soleus (slow) muscles were stimulated electrically via the sciatic nerve (5 Hz, 10 min). Under non-ischemic condition, the concentrations of IMP, inosine, adenosine, and hypoxanthine increased in EDL muscles but not in soleus muscles during stimulation. Under ischemic condition, these metabolites increased in both EDL and soleus muscles, although the increases in IMP and inosine were greater in EDL muscles. The increase in inosine had a strong positive correlation with that in IMP in ischemic EDL and soleus muscles, but the ratio, delta inosine/delta IMP was smaller in EDL muscles. The increase in adenosine under ischemic condition was not significantly different between the two muscles. These findings suggest that ischemia enhances degradation of purine nucleotides in contracting fast and slow muscles, and that although the degradation of purine nucleotides to IMP is greater in fast muscles than in slow muscles, the relative degradation rate of IMP to inosine is rather smaller in fast muscles.

Erythrocyte glycolysis and its marked alterations by muscular exercise in type VII glycogenosis

Levels of erythrocyte glycolytic intermediates after the phosphofructokinase (PFK) step, including 2,3-bisphosphoglycerate (2,3-DPG), were decreased at rest in patients from separate families with type VII glycogenosis. The concentration of 2,3-DPG was about half of the normal control value during a period of unrestricted daily activity but was further decreased to one third of normal after a one-day bed rest. Mild ergometric exercise rapidly increased the levels of fructose-1,6-bisphosphate, dihydroxyacetone phosphate plus glyceraldehyde-3-phosphate, and 2,3-DPG in patients' circulating erythrocytes but did not in those of normal subjects. This indicated that a crossover point at the PFK step in glycolysis disappeared after physical exercise and, consequently, the 2,3-DPG concentration, which had decreased because of blockage of the PFK step, was restored considerably. This apparently exercise-related alteration in intermediary metabolism at the beginning of glycolysis was reproduced in vitro by incubating normal erythrocytes in the presence of inosine or ammonia, both of which have increased levels in circulating blood during and after exercise in this disorder. We conclude that physical activity in addition to a genetic deficiency in erythrocyte PFK affects glycolysis in erythrocytes in type VII glycogenosis and that myogenic factors released from exercising muscles may be responsible for this change.

[Randomized comparison of continuous and intermittent oral administration of 5'-deoxy-5-fluorouridine in the treatment of advanced gastric cancer; a phase II trial by the Multi-institutional Cooperative Study Group]

To investigate the optimal dosage schedule for 5'-deoxy-5-fluorouridine (5'-DFUR), a randomized comparative study was performed in patients with inoperable or advanced gastric cancer. Eight hundred mg/m2/day of 5'-DFUR was administered in the continuous administration group, while in the intermittent administration group 1,400 mg/m2/day was given for 4 days followed by 3 days with no medication in a one-week cycle, making the total dose 5,600 mg/m2/week in both regimens. In both groups, 5'-DFUR was administered for more than 4 weeks. Overall response rate was 14.3% (3/21) for both administration methods. The response rate for the primary site was 9.5% (2/21) in the continuous administration group, and 14.3% (3/21) in the intermittent group. As to toxicity, the incidence of diarrhea was 26.7% in the continuous group and 4.2% in the intermittent group. Although there was no significant difference between these two dosage schedules in efficacy and toxicity, the lower incidence of diarrhea suggested the clinical usefulness of the intermittent administration method. This result emphasized the need to further studies to investigate the most appropriate dosage schedule for fluorinated pyrimidine derivatives.

Enhanced release of ammonia and hypoxanthine from exercising muscles in patients with idiopathic hypoparathyroidism

Semiischemic forearm exercise tests were carried out in two patients with idiopathic hypoparathyroidism who had muscle cramps and high serum levels of creatine kinase. Although cubital venous lactate levels increased normally after forearm exercise, venous ammonia and hypoxanthine were greatly increased. The abnormal responses of ammonia and hypoxanthine were normalized 3 months after treatment with 1 alpha-hydroxyvitamin D3. These findings suggest that excess purine degradation occurred in exercising muscles of patients with idiopathic hypoparathyroidism.

Myogenic hyperuricemia. A common pathophysiologic feature of glycogenosis types III, V, and VII

To identify the mechanism of hyperuricemia in glycogen storage diseases (glycogenoses) that affect muscle, we studied the effects of exercise and prolonged rest on purine metabolism in two patients with glycogenosis type III (debrancher deficiency), one patient with type V (muscle phosphorylase deficiency), and one patient with type VII (muscle phosphofructokinase deficiency). All had hyperuricemia except for one patient with glycogenosis type III. Plasma concentrations of ammonia, inosine, and hypoxanthine increased markedly in all the patients after mild leg exercise on a bicycle ergometer. The plasma urate concentrations also increased, but with a delayed response. Urinary excretion of inosine, hypoxanthine, and urate increased greatly after exercise, consistently with the increases in plasma levels. Hypoxanthine and urate concentrations were extremely high in the plasma and urine of the patient with glycogenosis type VII. With bed rest, the plasma hypoxanthine level returned to normal within a few hours, and the plasma urate concentration decreased from 18.6 to 10.6 mg per deciliter (1106 to 630 mumol per liter) within 48 hours. Similarly, the urinary excretion of these purine metabolites was reduced by bed rest. These findings indicate that muscular exertion in patients with glycogenosis types III, V, and VII causes excessive increases in blood ammonia, inosine, and hypoxanthine due to accelerated degradation of muscle purine nucleotides. These purine metabolites subsequently serve as substrates for the synthesis of uric acid, leading to hyperuricemia.

[Present diagnostic status of scirrhous type gastric cancer--with special reference to the endoscopic diagnosis]

First, we presented an actual diagnostic situation in nowadays for gastric cancer of Borrmann 4, which is virtually the same as scirrhous gastric cancer. Among 12 patients treated by the author, all of whom were discovered late, only 3 underwent surgery. In fact, with inoperable cases in Borrmann 4, even those endoscopically found to show insufficient stretching of the gastric wall, thickening and tortuosity of folds, uneven gastric mucosa, redness and white coating, there may be negative in gastric biopsy. However, the significance of an endoscopic examination for diagnosis of scirrhous cancer is in obtaining proof of the carcinoma (especially when still operable) by gastric biopsy. Thus, one must strive not to overlook slight redness, white coating which means small erosions, but to go over gastric biopsy again and again. Next, with carcinoma presenting a leather bottle (linitis plastica type) of the stomach itself, the II c portion of the stomach consisted of fundic glands (undifferentiated carcinoma) shall become the primary focus supporting Nakamura's theory. One case of diffuse invasive cancer, mistakenly diagnosed as a II c case, and two cases of regional type, one similar to II c and the other a Borrmann 2 carcinoma of advanced carcinoma showing strongly fibrous scirrhous tendency toward infiltration, were jointly monitored.