Potent inhibitory effect of troglitazone on carotid arterial wall thickness in type 2 diabetes

There is increasing evidence that insulin resistance may be causally related to atherosclerosis. The measurement of common carotid arterial intimal and medial complex thickness (IMT) by B-mode ultrasound technique has been recognized as a powerful and non-invasive method to evaluate early atherosclerotic lesions. We investigated the effect of treatment with troglitazone, an insulin sensitizer, on IMT in a total of 135 Japanese subjects with type 2 diabetes. Troglitazone (400 mg daily) was administered for 6 months in 57 patients. Compared to control group (n = 78), the group given troglitazone showed a significant decrease in IMT as early as 3 months after the administration (IMT change: -0.080[SE 0.016] mm vs. control 0.027[SE 0.007] mm, P < 0.001). The decrease in IMT was also found after 6 months, although further decrease was not observed. Both HbA1c and postprandial serum triglycerides were decreased after troglitazone, but there was no statistically significant relation between a decrease in IMT and those in HbA1c or postprandial triglycerides. These findings indicate that troglitazone has a potent inhibitory effect on progression of early atherosclerotic lesions probably through the decreased insulin resistance in type 2 diabetes.

Neurochemical changes in the spinal cord in degenerative motor neuron diseases

Human amyotrophic lateral sclerosis (ALS), a typical motor neuron disease, is characterized pathologically by selective degenerative loss of motoneurons in the CNS. We have demonstrated significant reductions of neurotransmitter-related factors, such as acetylcholine-(ACh)-synthesizing enzyme activity and glutamate and aspartate contents in the ALS, compared to the non-ALS spinal cord obtained at autopsy. We have also shown considerable reductions in activities of cytochrome-c oxidase (CO), an enzyme contributing to aerobic energy production, and transglutaminase (TG), a Ca(2+)-dependent marker enzyme for tissue degeneration, in the ALS spinal cord. We found marked increases in fragmented glial fibrillary acidic protein (GFAP), a filamentous protein specifically associated with reactive astrocytes, in the ALS spinal cord relative to non-ALS tissue. These biochemical results corresponded well to pathomor-phological neuronal degenerative loss and reactive proliferation of astroglial components in the ALS spinal cord tissue. However, these results only indicate the final pathological and biochemical outcomes of ALS, and it is difficult to follow up cause and process in the ALS spinal cord during progression of the disease. Therefore, we used an animal model closely resembling human ALS, motor neuron degeneration (Mnd) mutant mice, a subline of C57BL/6 that shows late-onset progressive degeneration of lower motor neurons with paralytic gait beginning around 6.5 mo of age, to follow the biochemical and pathological alterations during postnatal development. We detected significant decreases in CO activity during early development and in activity of superoxide dismutase (SOD), an antioxidant enzyme, in later stages in Mnd mutant spinal cord tissue. TG activity in the Mnd spinal cord showed gradual increases during early development reaching a maximum at 5 mo, and then tending to decrease thereafter. Amounts of fragmented GFAPs increased continuously during postnatal development in Mnd spinal cord. These biochemical changes were observed prior to the appearance of clinical motor dysfunctions in the Mnd mutant mice. Such biochemical analyses using appropriate animal models will be useful for inferring the origin and progression of human ALS.

Alteration of enzymatic activities implicating neuronal degeneration in the spinal cord of the motor neuron degeneration mouse during postnatal development

Oxidative stress is suggested as a significant causative factor for pathogenesis of neuronal degeneration on spinal cord of human ALS. We measured some enzymic activities implicating neuronal degeneration process, such as cytochrome c oxidase (CO), superoxide dismutase (SOD), and transglutaminase (TG) in spinal cord of an animal model of ALS, motor neuron degeneration (Mnd) mouse, a mutant that exhibits progressive degeneration of lower spinal neurons during developmental growth, and compared them with age-matched control C57BL/6 mice. CO activity in Mnd spinal cord decreased during early postnatal period, while SOD activity reduced in later stage. In Mnd tissue, TG activity in lumbar cord was increasing during early stage, but tended to decline in later period gradually. These biochemical alterations became evident prior to the appearance of clinical motor dysfunction which were observed in later stages of development in Mnd spinal cord.

[A case of traumatic lung cyst]

Traumatic lung cyst is an uncommon lung injury due to closed chest trauma. A 5-year-old boy was admitted to our hospital after being run over by motor vehicle. Computed tomography of the chest demonstrated multiple cystic lesions. This case was diagnosed as traumatic lung cysts. Computed tomography taken 37 days after initial injury showed complete resolution of the cysts. Computed tomography was useful in diagnosing traumatic lung cyst and following its clinical course.

Lateral difference in the reproduction of arm positioning movement: an examination of the hypothesis on the levels of psychological processes

The purpose of this study was to determine whether the hypothesis on the levels of psychological processes (Hatta, 1977, 1978) accounts for lateral differences in arm positioning movement (a spatial localization task). Fifteen right-handed male subjects were asked to perform a constrained criterion movement, 12 cm in length, with the left or right arm. Then, after a 10-sec retention interval, they were asked to perform the movement with the same arm, estimating lengths of 6, 12 or 24 cm. Different levels of psychological processes were assumed to be involved in estimating these various movement lengths--half, the same, or double that of the original. All possible combinations of the arm (left/right) and three movement length were tested. The CE scores were lower (more accurate) for the left arm (half; 1.5 +/- 8.1 mm, same; 4.3 +/- 6.2mm, double; 5.9 +/- 20.3 mm) than those for the right arm (half; 5.9 +/- 7.6 mm, same; 10.6 +/- 10.6 mm, double; 11.8 +/- 23.6 mm) in all conditions, indicating a lateral difference (the right hemisphere dominance) in arm positioning tasks. This typical lateral difference, which displayed no significant difference among conditions, is supposed to be mediated by complex or high-level psychological processes. These psychological processes are required by the subjects in the estimation of the various movement lengths. This study suggests that the level of psychological processes is a crucial factor in the manifestation of lateral differences in the performance of arm positioning movements.

Soluble CD23 and IL-5 levels in the serum and culture supernatants of peripheral blood mononuclear cells in a girl with cutaneous paragonimiasis: case report

We examined the levels of soluble CD23 (sCD23) and IL-5 in the serum and culture supernatants of the peripheral blood mononuclear cells of a 9-year-old girl with cutaneous paragonimiasis without respiratory symptoms. Before treatment, levels of both sCD23 and IL-5 in her serum and culture supernatants were elevated compared with those of controls. After successful treatment with praziquantel, sCD23 and IL-5 levels rapidly reduced to normal levels. These results indicate that sCD23 and IL-5 are involved in the immune-mediated pathological responses seen in paragonimiasis.

Increase of glial fibrillary acidic protein fragments in the spinal cord of motor neuron degeneration mutant mouse

We analyzed protein fractions extracted from the spinal cord of the motor neuron degeneration (Mnd) mouse, a mutant that exhibits progressive degeneration of lower spinal motor neurons, by one- and two-dimensional polyacrylamide gel electrophoresis (PAGE) after solubilization of the tissue with medium containing sodium dodecyl sulfate (SDS)-urea during growth of the animal, in comparison with those of age-matched controls (C57BL/6). Several protein spots were detected around a region of pI 5.6-6.0 and molecular mass of 35-50 kDa in Mnd spinal cord tissue on the two-dimensional PAGE separation profile with Coomassie brilliant blue staining, while only a few spots around the same region were found in the control spinal cord. These spots were all immunoreactive with an antibody against glial fibrillary acidic protein (GFAP), a cytoskeleton filamentous protein specific to astroglial cells. The protein spot with molecular mass of 50 kDa showed immunoreactivity with anti-GFAP antibody, had a blocked amino-terminus, and is assumed to be intact GFAP. Several protein spots with slightly smaller molecular masses of 35 to 48 kDa lacked the head domain of the GFAP molecule as a result of cleavage at the 29th and 56th residues from the amino terminus. In Mnd spinal cord tissue, the densities of the immunoreactive GFAP bands with smaller molecular masses increased with development, and became dominant at the time of the appearance of behavioral paralytic gait around 6 to 7 months of age. These results suggest that the increased GFAPs devoid of head domains are related to the degenerative loss of motor neurons in the Mnd spinal cord. Histopathological and GFAP immunohistochemical examination of Mnd spinal cord preparation demonstrated progressive degenerative loss of motor neurons, and considerable increases in number of GFAP-stained astrocytes in the ventral horn at 7 to 9 months of age. These processes of degenerative loss of motor neurons and proliferation of reactive astrocytes with increased levels of fragmented GFAP in the Mnd spinal cord during development seem to be characteristic and preceded the deterioration of motor activities in this animal model of amyotrophic lateral sclerosis.

Structure, chromosomal location, and expression profile of EXTR1 and EXTR2, new members of the multiple exostoses gene family

Hereditary multiple exostoses (EXT) is an autosomal dominant disorder that is characterized by the appearance of multiple outgrowths of the long bones (exostoses) at their epiphyses. Genetical heterogeneities have segregated at least on chromosome 8, 11, and 19 and been designated EXT1, EXT2, and EXT3, respectively. Recently, the responsible genes for EXT1 and EXT2 have been isolated and appeared to define a structurally related gene family. In the present study, we have identified novel genes which share significant sequence homologies with the EXT genes. The predicted protein products of the novel EXT-related genes, EXTR and EXTR2 (for EXT-related genes 1 and 2), consist of 919 and 330 amino acid residues, respectively. These genes were transcribed ubiquitously in various tissues. Based on PCR-assisted analyses of both a human/rodent mono-chromosomal hybrid cell panel and a radiation hybrid mapping panel, EXTR1 was localized to the chromosome 8p21 region, where loss of heterozygosity has been frequently observed in various tumors, and EXTR2 was assigned to the chromosome 1p21 region, where osteopetrosis, a dominant hereditary disease of bone, has been mapped by genetic linkage analysis, implying that the protein products of these two EXT-related genes, as well as of the EXT genes, have potential tumor suppressor activity.

Apatite induction by insoluble dentin collagen

Phosphoproteins are thought to play a role in mineral formation in dentin. A portion of this phosphoprotein is bound to collagen. We have investigated the requirement for bound phosphate in mineral induction by isolated dentin collagen. Insoluble bovine dentin collagen obtained by ethylene-diamino-tetra-acetic acid (EDTA) demineralization had 19.5 mol of P/mol of collagen that could not be extracted with 0.5 M EDTA in 4 M guanidine HCl. When this collagen was incubated in supersaturated solutions that did not spontaneously precipitate, apatite was induced. With progressive enzymatic dephosphorylation, induction times for mineral formation became progressively longer. The dentin did not induce mineral formation when 90% of the ester phosphate was removed. Insoluble bone collagen, which had even less phosphate, also did not induce mineral formation. Mineral induction times by dentin collagen increased with decreasing solution saturations. Using these data, the interfacial tension for mineral induction was determined to be 90 ergs/cm2. This value approximated that of phosphatidic acid liposomes and of phosvitin cross-linked to agarose beads, and it might reflect the energetics of heterogeneous nucleation on a highly phosphorylated surface. Sequestering of calcium-phosphate clusters on the phosphoprotein probably accounts for the observed calcium binding by dentin collagen in excess of that required to neutralize the phosphate esters of the collagen. Because the phosphoprotein is immobilized at a low density on the collagen, it cannot self-associate in calcium-phosphate solutions as it does when it is free in solution. This immobilized phosphoprotein allows the mineral clusters formed on its surface to grow into a crystalline order.

A distamycin A-inducible fragile site, FRA8E, located in the region of the hereditary multiple exostoses gene, is not involved in HPV16 DNA integration and amplification

The rare fragile site is a specific point on a chromosome that is expressed as an isochromatid gap or break under certain conditions of cell culture and is inherited in a Mendelian codominant fashion. Five folate-sensitive fragile sites were cloned, and the molecular basis of fragile site mutation was shown to be a new class of mutation, called dynamic mutation, resulting from an allelic expansion of (CCG)n repeats. The mechanism responsible for other types of rare fragile sites, i.e., distamycin A-inducible and BrdU-requiring, is unknown, although cytogenetic studies suggested that these fragile sites play a mechanistic role in breakage and recombination and may also be integration and modification sites of foreign viral DNA genomes. A distamycin A-inducible fragile site, FRA8E, is mapped to 8q24.1 in which various loci implicated in genomic instability are located. Here we identified a YAC clone spanning both FRA8E and the hereditary multiple exostosis (EXT1) gene, using fluorescence in situ hybridization (FISH) analysis of a yeast artificial chromosome (YAC) contig. By using P1 clones as probes, the FRA8E locus was further localized to a 400-kb region including the EXT1 gene. Furthermore, the integration and amplification site of human papillomavirus 16 DNA in the ASCC (argyrophil small cell carcinoma) cells were shown not to coincide with FRA8E, but to be involved in an extensively broad genomic region of 8q24.1, including the c-myc gene.

Increases in fragmented glial fibrillary acidic protein levels in the spinal cords of patients with amyotrophic lateral sclerosis

Using one-dimensional polyacrylamide gel electrophoresis, we analyzed protein fractions extracted from the spinal cords of patients with amyotrophic lateral sclerosis (ALS). Several protein bands with molecular weights of 35-55 kDa were stained with Coomassie brilliant blue much more intensely in the ALS than in the non-ALS spinal cord. Glial fibrillary acidic protein (GFAP) immunoreactivity showed a significant decrease of 50 and 45 kDa band and increase in fragmented 36 and 37 kDa bands, which represented GFAP fragments devoid of 59 and 40 residues from the N-terminal, respectively, as determined by protein sequence analysis. Immunohistochemical examination of ALS spinal cord transections demonstrated increased GFAP-stained astrocytes in the shrunken ventral horn with massive degeneration of motoneurons. These results will provide new insight into the possible role of astrocytes in the pathophysiology and/or pathogenesis of ALS.

Direct evidence for the role of nitric oxide on the glutamate-induced neuronal death in cultured cortical neurons

It has been reported that glutamate-induced neurotoxicity is related to an increase in nitric oxide (NO) concentration. An NO-sensitive electrode has been developed to measure NO concentration directly. Using this electrode, we examined NO concentration and neuronal survival after glutamate application in rat cultured cortical neurons. We also examined the effects of NMDA receptor antagonists, MK-801 and ketamine, and the NO synthetase inhibitor, L-NMMA on NO production and neuronal death. After 7 days in culture, application of glutamate (1 mM) or L-arginine (0.3 mM) to the cultured medium increased NO concentration, and decreased the number of anti-microtubule-associated protein 2 positive neurons. Both pretreatment with MK-801 (300 microns) and ketamine (300 microns) prevented glutamate-, but not L-arginine-induced increase in NO concentration and neuronal death. L-NMMA prevented both glutamate- and L-arginine-induced NO production and neuronal death. The nitric oxide donor, S-nitroso-N-acetyl-D,L-penicillamine (SNAP) also caused neuronal death, and MK-801, ketamine and L-NMMA did not prevent SNAP-induced toxicity. We have demonstrated excitatory amino acid-induced changes of NO concentration and the parallel relationship between changes of NO concentration and neuronal death. In conclusion, an increase in NO concentration does induce neuronal death, and the inhibition of the production of NO prevents glutamate-induced neuronal death.

Effects of Hochu-ekki-to, Yoku-kan-san and Saiko-ka-ryukotsu-borei-to on behavioral despair and acetic acid-induced writhing in mice

Effects of the Kampo (Chinese herbal) medicines Hochu-ekki-to Yoku-kan-san and Saiko-ka-ryukotsu-borei-to, on behavioral despair and acetic acid-induced writhing were studied in mice. The Kampo medicines were administered for 14 consecutive days in the drinking water. In a behavioral despair study, mice were placed in a water tank containing a water wheel from which there was no escape for 15 min and the number of wheel rotations was counted as escape attempts. In accord with previous studies, imipramine (10 mg/kg i.p.) given daily for 3 days 10 min before testing markedly increased the number of wheel rotations. Hochu-ekki-to (60, 150 and 300 mg/kg/day) similarly increased the number of wheel rotations but the effect was not dose-dependent. Yoku-kan-san markedly increased the number of wheel rotations at lower doses (60 and 150 mg/kg/day), but decreased the number at the highest dose (300 mg/kg/day). Saiko-ka-ryukotsu-borei-to also increased the number of wheel rotations at the lowest does (60 mg/kg/day) but decreased the number at higher doses (150 and 300 mg/kg/day). In an antinociception study, all these Kampo medicines reduced the number of acetic acid-induced writhings, although the effect of Saiko-ka-ryukotsu-borei-to were not dose-dependent. These results suggests that these Kampo medicines may have antidepressive and antinociceptive properties.

A cartilage matrix deficiency experimentally induced by vitamin B6 deficiency

A vitamin B6-deficiency-induced disorder in avian articular cartilage resembling osteoarthritis has been further characterized. We measured several parameters of proteoglycan (PG) metabolism, i.e., fixed charge density and sulfated glycosaminoglycans (S-GAG) content in PN-deficient versus control articular cartilage and synovial fluid from the knee joint. Statistically significant changes were: 1) decreased content and increased extractability of total sulfated PGs from articular cartilage with guanidine HCl; 2) elevation of S-GAG concentration in synovial fluid; 3) increased plasma cystathionine (sulfur amino acid) levels. PG synthesis as assessed by 35SO4 incorporation into S-GAGs was not impaired. A lack of cartilage swelling in 0.15 M saline and the normal water content indicated that although disturbed, the collagen network was not disrupted. This finding was in agreement with a previous microscopic study that revealed no fissures in the articular cartilage. Previous findings of a normal aggregating PG size-distribution and absence of elevated metalloproteases made a disturbance of aggregating PG metabolism unlikely. Escape into the synovial fluid of small PGs, normally bound to articular collagen, was believed to result from an alteration in collagen molecular organization that could be secondary to elevated circulating SH-compounds.

Protective effects of nicaraven, a new hydroxyl radical scavenger, on the endothelial dysfunction after exposure of pig coronary artery to hydroxyl radicals

Recently, we have reported that a new synthetic compound, 1,2bis(nicotinamido)-propane (nicaraven), improved cardiac function following preservation and reperfusion. In this study, we investigated the efficacy of nicaraven as a radical scavenger by using an in vitro model of oxidative stress, to clarify mechanisms of the protective effect of this new compound on reperfusion injury in rat heart. Ring segments of epicardial right coronary arteries (RCA) of pig were suspended in organ chambers and exposed to hydroxyl radicals (.OH), generated (by two different systems) by 0.28 mM FeSO4/0.28 mM H2O2 and DHF/Fe3+-ADP (2.4 mM, 43 nM, and 1.56 uM, respectively) to the bathing solution for 60 min. Prior exposure of the coronary arteries to .OH significantly produced right-ward shift of the dose-response curves of the bradykinin-induced endothelium-dependent relaxations (an increase in the ED50 value for bradykinin by 4.37 and 1.98 times than control in two different .OH generating systems, respectively), but did not affect the maximum relaxation responses. The presence of nicaraven (10(-4) and 10(-5) M) in the .OH generating system, shifted the dose-response curves to bradykinin to the control level, suggesting a significant hydroxyl radical scavenging effect of the drug. These results indicate that nicaraven, a new hydroxyl radical scavenger, exhibits a protective effect on hydroxyl radical-induced endothelial dysfunctions of pig coronary artery.

A case of sarcoid reaction associated with papillary thyroid carcinoma

Sarcoid reaction, a granulomatous lesion similar to those seen in sarcoidosis, has been reported to be associated with various disorders. Here we describe a 54-year-old woman, who was diagnosed with sarcoid reaction associated with papillary carcinoma of the thyroid. Her history included total thyroidectomy with radical neck dissection for a papillary carcinoma of the thyroid. She was found to have a right subclavian mass. Dissection of the mass was performed for the diagnosis of metastatic papillary carcinoma to the lymph node, but the pathological examination showed granuloma without caseation as well as metastasis to the lymph node. Polymerase chain reaction (PCR) of the specimen excluded a possibility of Mycobacterium infection. There was no supporting evidence for systemic sarcoidosis in this patient; the patient showed no skin, eye, or lung lesions, or bilateral hilar lymphadenopathy, and she did not show increase in serum gamma-globulin or in plasma angiotensin-converting enzyme (ACE) levels, or increased CD4/CD8 ratio of lymphocytes obtained from bronchoalveolar lavage. These findings suggest that the present case had sarcoid reaction associated with papillary carcinoma. Although sarcoid reaction has been reported to be associated with various malignancies, only five cases, to our knowledge, are reported in the literature, which were associated with papillary carcinoma.

Onset of vecuronium neuromuscular blockade at the hand with an arterio-venous shunt

PURPOSE

To evaluate the onset of vecuronium neuromuscular blockade in the hand with an arterio-venous shunt for haemodialysis.

METHODS

In 15 adult patients receiving haemodialysis for renal failure the onset of vecuronium-induced neuromuscular blockade after 0.08 mg-kg-1 vecuronium i.v. was measured. Using train-of-four mechanomyographic monitoring, the force of contraction of the adductor pollicis of both hands with and without arterio-venous shunt was measured simultaneously.

RESULTS

The times from the injection to the first depression of twitch response (latent onset) and 95% twitch depression (onset) in the hand with and without arterio-venous shunt were 114.7 +/- 33.4 and 218.7 +/- 59.9 and 117.3 +/- 34.3 and 208.7 +/- 60.9 sec respectively. No difference in the onset of vecuronium neuromuscular blockade in the hand an arterio-venous shunt was demonstrated.

CONCLUSION

The presence of an arteriovenous fistula does not modify the onset on neuromuscular blockade. Either arm can be used to monitor onset of neuromuscular blockade in chronic renal failure patients with an arterio-venous shunt in the hand for haemodialysis.

Identification, partial characterization, and distribution of versican and link protein in bovine dental pulp

The dynamics of changes in the cellularity and extracellular matrix composition of dental pulp varies considerably during tooth development and maturation. In this paper, we studied matrix proteoglycans where we hypothesized that they played important roles in structural, spatial, and transport aspects of pulpal development and maintenance. The pulpal tissue was collected from partially erupted bovine incisors, pulverized, and then extracted with 6 M guanidine-HCl. The extract was subjected to anion column chromatography (DEAE-8HR), and the fractions collected were screened by dot-blot immunoassay by means of monoclonal antibodies generated against 4- and 6-sulfated chondroitin sulfate isomers, and keratan sulfate, 2-B-6, 3-B-3, and 5-D-4, respectively. The chondroitin-6-sulfate was the major glycosaminoglycan species and occurred as a large-molecular-weight proteoglycan (> 500 kDa). After further purification, it was subjected to agarose/acrylamide composite gel electrophoresis, and it migrated as a single band stained with Stains-All. The band was immunopositive against antibody 3-B-3 by Western blot analysis. The partial amino acid sequence analyses of the core protein clearly indicated this molecule to be versican. The presence of link protein was also confirmed by Western blot analysis with an anti-link protein monoclonal antibody, 8-A-4. Furthermore, immunohistochemical study indicated that the distributions of versican and link protein coincide in the dental pulp and are enriched in the peripheral area of the tissue just beneath the odontoblast layer. Since the dental pulp contains hyaluronan, versican may bind to hyaluronan via its hyaluronan-binding domain, where this association is stabilized by link protein. This complex, then, could form large hydrated proteoglycan aggregates that fill the extracellular space, support odontoblasts, and/or facilitate the transport function of metabolites and nutrients within the tissue.

Phosphodiesterase type 4 that regulates cAMP level in cortical neurons shows high sensitivity to rolipram

To characterize the role of phosphodiesterase type 4 (a cAMP-specific and rolipram-sensitive phosphodiesterase) among phosphodiesterases in the regulation of the intracellular cAMP level in cortical neurons, we investigated the effects of phosphodiesterase inhibitors on the intracellular cAMP levels in primary cultured rat cortical neurons. Selective inhibitors of phosphodiesterase type 4 and type 2 significantly enhanced beta-adrenoceptor-mediated cAMP increase. Selective inhibitors of phosphodiesterase type 1, type 3 and type 5/6 had no effect on the cAMP level. Rolipram enhanced the beta-adrenoceptor-mediated cAMP increase in cortical neurons, astrocytes and vascular smooth muscle cells at different minimum effective concentrations (10, 100 and 1000 nM, respectively). These findings indicate that phosphodiesterase type 4, showing a high-sensitivity to rolipram, plays a major role in regulating cAMP in the cortical neurons, and that rolipram at low doses enhances the intracellular cAMP increase in the cortical neurons selectively.

Mineral induction by immobilized phosphoproteins

Dentin phosphoproteins are thought to have a primary role in the deposition of mineral on the collagen of dentin. In this study we determined the type of binding between collagen and phosphoproteins necessary for mineral formation onto collagen fibrils and whether the phosphate esters are required. Bovine dentin phosphophoryn or phosvitin from egg yolk were immobilized on reconstituted skin type I collagen fibrils by adsorption or by covalent cross-linking. In some samples the ester phosphate was removed from the covalently cross-linked phosphoproteins by treatment with acid phosphatase. All samples were incubated at 37 degrees C in metastable solutions that do not spontaneously precipitate. Reconstituted collagen fibrils alone did not induce mineral formation. The phosphoproteins adsorbed to the collagen fibrils desorbed when the mineralization medium was added, and mineral was not induced. The mineral induced by the cross-linked phosphoproteins was apatite, and the crystals were confined to the surface of the collagen fibrils. With decreasing medium saturation the time required for mineral induction increased. The interfacial tensions calculated for apatite formation by either phosphoprotein cross-linked to collagen were about the same as that for phosphatidic acid liposomes and hydroxyapatite. This similarity in values indicates that the nucleation potential of these highly phosphorylated surfaces is about the same. It is concluded that phosphoproteins must be irreversibly bound to collagen fibrils for the mineralization of the collagen network in solutions that do not spontaneously precipitate. The phosphate esters of phosphoproteins are required for mineral induction, and the carboxylate groups are not sufficient.

Molecular cloning and expression of a rat cDNA encoding 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase

The cDNA of a 5-aminoimidazole-4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (AICARFT/IMPCHase) was isolated from rat liver RNA by reverse transcription and the polymerase chain reaction (PCR). The rat AICARFT/IMPCHase cDNA included 1928 bp containing a coding region of 1779 bp for a 592-amino acid polypeptide (Mr = 64 200). Rat and human AICARFT/IMPCHase cDNAs show 84 and 91% homology at the nucleotide and amino acid sequence level, respectively. The protein produced by the rat cDNA using pET-expression system catalysed the penultimate and final steps of de novo purine biosynthesis. Northern analysis identified a 2.8-kb AICARFT/IMPCHase mRNA and the level of the AICARFT/IMPCHase transcripts increased markedly at 24 h after partial (70%) hepatectomy.

[Re-rupture of intracranial aneurysm caused by insertion of an intraventricular drainage tube]

A 42-year-old man was admitted to our hospital with subarachnoid hemorrhage, requiring the clipping of an intracranial aneurysm and removal of intracranial hematoma. Anesthesia was induced with thiamylal and maintained with oxygen-nitrous oxide-isoflurane. Trimethaphan was administered continuously and his systolic blood pressure was stably maintained between 100-110 mmHg. Seven minutes after insertion of an intraventricular drainage tube through the dura, his blood pressure increased to 146/76 mmHg. By transdural echogram, re-rupture of the aneurysm was confirmed, and after 6 minutes, a fresh intracranial hematoma was observed. The decrease of intracranial pressure following insertion of the intraventricular drainage tube or the stimulation by several intraventricular punctures seems to have caused re-rupture of the aneurysm. When hemodynamic change is observed without obvious cause in a patient with subarachnoid hemorrhage, it is important to speculate that a re-rupture of the aneurysm has occurred, and to treat the problem accordingly.

[Tricuspid valve replacement for infectious endocarditis associated with ventricular septal defect--report of three cases]

We reported two male and one female patient (17, 36 and 47 years old, respectively) who presented infectious endocarditis (IE) in association with ventricular septal defect (VSD). In all cases, surgical treatment was performed in the acute stage of IE for persistent sepsis, pulmonary embolisms, and for giant vegetations. Because the tricuspid valve apparatus was severely damaged, valve replacement with the Carpentier-Edwards pericardial bioprosthesis was done and small VSD was directly closed in all cases. In one case, a complete heart block occurred, which necessitated postoperative implantation of a permanent pacemaker. All patients recovered and resumed their original social activities without the relapse of endocarditis.