Cloning of cDNA encoding for a novel isozyme of fructose 6-phosphate, 2-kinase/fructose 2,6-bisphosphatase from human placenta

Two independent cDNA clones encoding fructose 6-phosphate, 2-kinase/fructose 2,6-bisphosphatase were isolated from a human placental cDNA library. The deduced amino acid sequences showed that one of the clones, 2K-1, was almost identical to the rat testis isozyme and the other, 2K-3, was different from any known isozymes expressed in mammalian tissues. The results of Southern blot analysis suggested that clones 2K-1 and 2K-3 were encoded as single copy genes and located in different parts of the genome. Since open reading frames of the cDNA clones were not complete, we obtained the 5'-end of the clone 2K-3 cDNA using the 5'-rapid amplification of cDNA end method. The entire cDNA (HP; 1,756 bp) had a coding capacity of 519 amino acids (M(r) = 59,410), and putative phosphorylation sites for protein kinases A and C on the C terminus. Northern blot analysis using a fragment of the HP as a probe showed that a major band of 5.4 kb, significantly different in size from known isozyme mRNAs such as liver (2.1 kb), muscle (1.9 kb), heart (4.0 kb), and testis (2.0 kb), was present in poly(A)+RNA preparations of human first trimester and term placentae. These results strongly suggested that this 5.4 kb mRNA codes a novel isozyme of fructose 6-phosphate,2-kinase/fructose 2,6-bisphosphatase.

[Serial changes of SPECT and MRI findings in a patient with herpes simplex encephalitis]

We report a case of herpes simplex encephalitis in which the patient was repeatedly examined by magnetic resonance imaging (MRI) and single photon emission computed tomography (SPECT). The patient was a 36 year-old woman who had been transferred to our institution 6 days after the onset of symptoms with mild consciousness disturbance, nuchal rigidity, and high fever. Cerebrospinal fluid examination revealed an elevated mononuclear cell count with normal sugar concentration. Intravenous aciclovir was started 7 days after the onset of symptoms. The initial plain computed tomography (CT) scans did not reveal any abnormal findings, but contrast enhanced CT the next day showed a slight enhancement effect around the affected middle cerebral artery. Serial MRI showed the initial high intensity lesion starting on the medial cortex of the temporal lobe, then spreading to throughout the entire temporal lobe. During this period SPECT showed a marked, broad hot spot in the temporal lobe. The medial temporal lobe was high density on the CT 15 days after the onset. As the encephalitic lesion spread more laterally, the hot spot on SPECT moved laterally and then decreased in activity. Eleven weeks after the onset, the MRI showed intracerebral vacuolization of the lesion and it appeared as a wide cold spot on SPECT. The cause of the hot spot seen in the acute period was thought to be vasoparalysis of the affected area rather than breakdown of the blood-brain barrier, or impaired washout of the isotope, because the SPECT images after acetazolamide administration showed the cold spot even in the subacute phase.

A 13-Mer peptide of a brain injury-derived protein supports neuronal survival and rescues neurons from injury caused by glutamate

Neuronal survival is mediated by several kinds of proteins. Among these, neurotrophic factors play important roles in the nervous system by supporting neuronal activity and survival. It has been suggested recently that certain factors promote neuronal survival in the case of brain injury. To examine this possibility, we purified a novel neurotrophic factor from Gelfoam that was implanted at the site of injury caused in neonatal rats. During amino acid sequence analysis, we found that a fragmental peptide of this neurotrophic protein consisting of 13 amino acids showed neurotrophic activity. This 13-mer peptide promoted survival of septal cholinergic and mesencephalic dopaminergic neurons in culture and rescued hippocampal neurons from injury caused by glutamate in culture. This peptide rescued neurons from cell death caused by glutamate, even when added 4.5 h after glutamate exposure.

Purification and characterization of high molecular weight hCG from human first trimester placenta

Human chorionic gonadotropin (hCG) in first trimester placental cells is composed of immature alpha- and beta-subunits containing only N-linked high-mannose sugar chains. Intracellular immature intermediates are accumulated in rough endoplasmic reticulum in much greater quantity than mature hCG composed of mature subunits. We have previously shown that this immature hCG might be bound to other protein(s), including an ATP-binding protein, forming high molecular weight-hCG (HMW-hCG), which is not aggregate of immature hCG alone. To identify the ATP-binding protein forming the HMW-hCG in detail, proteins in HMW-hCG preparation were photoaffinity-labeled with 8-azido-[alpha-32P]ATP. Autoradiography followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that the labeled protein with M(r) = 78000 was immunoprecipitated with any antibody against alpha-subunit, beta-subunit and hCG, indicating that this protein is bound to immature hCG. Furthermore, to determine whether some other proteins associate to form HMW-hCG, we purified HMW-hCG without breakdown to its components using columns of DE52, Heparin-Sepharose and Sephacryl S-300. As the final step of the purification, HMW-hCG was allowed to adsorb on a column of ATP-agarose and anti-hCG IgG-agarose, respectively. SDS-PAGE analysis of eluted proteins from the columns bound to the respective column via the constituent of HMW-hCG, such as ATP-binding protein or immature hCG, showed four common protein bands with molecular weights of 78000, 43000, 28000 and 20000. The protein with M(r) = 43000 was stained with any antibody against alpha-subunit, beta-subunit and hCG, indicating it to be immature hCG. The protein band with M(r) = 78000, which might correspond to the ATP-binding protein described above, was stained with anti-heat shock protein 70 (HSP70) monoclonal antibody. To confirm the association of immature hCG and HSP70-like protein, immature hCG preparation was incubated with HSP70-like protein purified from placental extracts. The molecular weight change of immature hCG appeared to increase by this incubation and was close to HMW-hCG, but not exactly the same. These results suggest that immature hCG intermediate exists as HMW-hCG containing HSP70-like protein, which has ATP-binding capacity, and two other proteins in first trimester placental cells.

The binding of ricin to its receptor is not required for the expression of its toxicity

Ricin toxin is a toxic glycoprotein comprising two polypeptide chains, A and B, joined by a disulfide bond. The binding of its B-chain to the cell surface glycoconjugate having non-reducing terminal galactose (ricin receptors) has been assumed to allow the internalization of ricin into the cell, followed by the release of the free A-chain into cytosol, which then inhibits cellular protein synthesis in eukaryotic cells (cytotoxic effect). In order to investigate whether the binding of ricin to its receptors is essential to the expression of its toxicity, ricin was allowed to be incorporated into the cells using liposome encapsulated ricin (ricin-encapsulated liposomes). Protein synthesis in cultured Hela cells was inhibited by incubation not only with intact ricin but also with ricin-encapsulated liposomes, indicating that the binding of ricin to its receptor is not required for the expression of its toxicity.

[De novo aneurysm associated with a persistent primitive trigeminal artery: case report]

This paper presents a case of a de novo unruptured anterior communicating aneurysm associated with a persistent primitive trigeminal artery. The patient was a 65-year-old female with tinitis, for whom computed tomography with contrast medium indicated right dural enhancement. Dural arteriovernous malformation was suspected and angiography was thus conducted. A right persistent primitive trigeminal artery was demonstrated but no aneurysm could be found. Six years later, magnetic resonance angiography indicated an aneurysm on the anterior communicating artery. It was subsequently removed by surgery. A persistent primitive artery is frequently found to accompany aneurysm but de novo aneurysm associated with such an artery does not appear in the literature to date. The authors emphasize the importance of follow-up angiography in cases of persistent primitive artery not accompanied by an aneurysm.

Expression and distribution of low density lipoprotein receptor-related protein mRNA in the rat central nervous system

The low density lipoprotein receptor-related protein (LRP) is a multifunctional cell surface receptor that binds to the protease inhibitor alpha 2-macroglobulin (alpha 2 M). LRP has also been identified as the apolipoprotein E (apoE) receptor that mediates lipid metabolism. Recently it has been reported that apoE4, one of three common isoforms of apoE, is a main risk factor of Alzheimer's disease (AD). Moreover, all three of these proteins are reported to accumulate in the senile plaques in the brains of Alzheimer's patients. To understand the roles of LRP in the normal development of the central nervous system (CNS) and in the pathogenesis of AD, we studied the developmental expression and localization of LRP mRNA in the CNS. We used Northern blot analysis to investigate the developmental profile of LRP mRNA in the rat brain. LRP mRNA was first detected as early as in 18-day-old embryonic rat brain and was continuously expressed thereafter. A particularly high level of expression of the mRNA was observed in the perinatal stage. We also determined the cellular distribution of LRP mRNA in the CNS of 20-day-old embryonic and 6-week-old adult rat brains by in situ hybridization using a digoxigenin-labeled antisense riboprobe to LRP mRNA. In the embryonic rat brain, LRP mRNA was highly expressed in most of the cells, mainly neurons and glial cells. In the adult rat, LRP mRNA was expressed mostly in neurons in both the brain and the spinal cord. These results suggest that LRP plays crucial roles in development of the brain.

Cloning and sequence of the gene encoding a cefotaxime-hydrolyzing class A beta-lactamase isolated from Escherichia coli

Escherichia coli TUH12191, which is resistant to piperacillin, cefazolin, cefotiam, ceftizoxime, cefuzonam, and aztreonam but is susceptible to cefoxitin, latamoxef, flomoxef, and imipenem, was isolated from the urine of a patient treated with beta-lactam antibiotics. The beta-lactamase (Toho-1) purified from the bacteria had a pI of 7.8, had a molecular weight of about 29,000, and hydrolyzed beta-lactam antibiotics such as penicillin G, ampicillin, oxacillin, carbenicillin, piperacillin, cephalothin, cefoxitin, cefotaxime, ceftazidime, and aztreonam. Toho-1 was markedly inhibited by beta-lactamase inhibitors such as clavulanic acid and tazobactam. Resistance to beta-lactams, streptomycin, spectinomycin, sulfamethoxazole, and trimethoprim was transferred by conjugational transfer from E. coli TUH12191 to E. coli ML4903, and the transferred plasmid was about 58 kbp, belonging to incompatibility group M. The cefotaxime resistance gene for Toho-1 was subcloned from the 58-kbp plasmid by transformation of E. coli MV1184. The sequence of the gene for Toho-1 was determined, and the open reading frame of the gene consisted of 873 or 876 bases (initial sequence, ATGATG). The nucleotide sequence of the gene (DDBJ accession number D37830) was found to be about 73% homologous to the sequence of the gene encoding a class A beta-lactamase produced by Klebsiella oxytoca E23004. According to the amino acid sequence deduced from the DNA sequence, the precursor consisted of 290 or 291 amino acid residues, which contained amino acid motifs common to class A beta-lactamases (70SXXK, 130SDN, and 234KTG). Toho-1 was about 83% homologous to the beta-lactamase mediated by the chromosome of K. oxytoca D488 and the beta-lactamase mediated by the plasmid of E. coli MEN-1. Therefore, the newly isolated beta-lactamase Toho-1 produced by E. coli TUH12191 is similar to beta-lactamases produced by K. oxytoca D488, K. oxytoca E23004, and E. coli MEN-1 rather than to mutants of TEM or SHV enzymes. Toho-1 has shown the highest degree of similarity to K. oxytoca class A beta-lactamase. Detailed comparison of Toho-1 with other beta-lactamases implied that replacement of Asn-276 by Arg with the concomitant substitution of Thr for Arg-244 is an important mutation in the extension of the substrate specificity.

Inhibition of polar body formation in mouse denuded oocytes cultured in vitro by protein synthesis inhibitors

Denuded oocytes obtained from the ovaries of ddY mice underwent spontaneous germinal vesicle breakdown (GVBD) and polar body formation (PBF) by cultivation for 3 and 16 h, successively. To study the significance of protein synthesis in oocytes regarding their maturation, denuded oocytes were cultured in the presence of reversible (cycloheximide and puromycin) and irreversible (ricin) protein synthesis inhibitors. When denuded oocytes were cultivated in the continual presence of any inhibitor, only PBF but not GVBD was found to be inhibited. These inhibitions were dose dependent, ranging from 10(-9) to 10(-6) M, and were relative to the protein synthesis inhibitions by them. The PBF inhibition was relieved by withdrawing cycloheximide for first 2, 3 and 4 h in the course of the culture. Further, the PBF inhibition occurred in the presence of ricin for only the first 2 or 3 h in the course of the culture. These results suggested that proteins synthesized during 2 to 4 h in the course of culture may play important role in PBF.

Expression, purification, and neurotrophic activity of amyloid precursor protein-secreted forms produced by yeast

The secreted form of amyloid precursor protein (APPs) including most of the extracellular domain of APP is released from the cell surface, suggesting physiological significance of APPs in vivo. We used the methylotrophic yeast Pichia pastoris as a host system for the production of recombinant APPs (rAPPs). Two rAPPss derived from isoforms of APP (APP695 and APP770) were secreted into the culture medium from the yeast, which carried cDNA encoding the N-terminal portion of APP under the control of a P. pastoris alcohol oxidase promoter. Like APPss produced by the transfected COS-1 cells, the purified rAPPss from yeast were shown to be biologically active in terms of neurite outgrowth of embryonic rat neocortical explants. These rAPPss could be valuable tools for investigating the biological functions of APPss.

The occurrence of nicked human chorionic gonadotropin (hCG) by a thermolytic endoprotease

A nicked form of human chorionic gonadotropin (nicked hCG), in which only one peptide bond between residues 47 and 48 (-Gly-Val-) of beta-subunit is cleaved, has been found in the urine and blood of pregnant women. In this study, we investigated the occurrence of nicked hCG and the localization of the nicking enzyme for hCG. First, to determine what type of protease nicks hCG, an in vitro proteolytic study using various proteases was performed. Amino-terminal amino acid sequence analysis of the beta-subunit purified from protease-treated hCG indicated that thermolysin actively nicks hCG. Secondly, to determine which tissues are related to the formation of nicked hCG, the distribution of radioactivity in various tissues after i.v. administration of radiolabeled hCG to female rats was examined. The radioactivity accumulated predominantly in the kidney (17%), liver (9.3%) and ovary (0.9%) after 30 min of injection. Analysis of molecular species of beta-radiolabeled hCG in various tissues and body fluids, using sodium dodecyl sulfate polyacrylamide gel electrophoresis followed by autoradiography, indicated that a nicked hCG-like molecule was found in the kidney, predominantly, as well as in the serum and urine. To examine the role of the kidney in producing nicked hCG, hCG was incubated with rat kidney particulate fraction (KPF). Immunoblot analysis of KPF-treated hCG indicated that KPF produced a nicked hCG-like molecule. Furthermore, the possibility that placental trophoblast cells produce nicked hCG was also examined using the choriocarcinoma cell BeWo.(ABSTRACT TRUNCATED AT 250 WORDS)

Oligomannose-coated liposomes as an adjuvant for the induction of cell-mediated immunity

The effect of the coating of ovalbumin-reconstituted liposomes with various oligosaccharides on their immunogenicity was investigated in mice. The coating of liposomes with oligomannose or yeast mannan drastically enhanced their ability to induce an ovalbumin-specific delayed-type footpad swelling response with a peak at 24 to 48 h post-challenge. Among various oligosaccharides tested, only those with mannose residue at the nonreducing termini manifested the activity when applied to liposomes. Since such oligosaccharides are ubiquitously found in the body, these results suggested the usefulness of oligomannose-coated liposomes as a safe adjuvant for the induction of cell-mediated immunity.

On the conformation of Phe78 of a chromoprotein antibiotic, neocarzinostatin

A structure of neocarzinostatin, an antitumor chromoprotein antibiotic, has been built using X-ray crystallographic data and NMR data, particularly NOE data observed between the apoprotein and the chromophore. Chemical shift changes of protons of the chromophore upon binding to the apoprotein indicated that the aromatic plane of Phe52 has the conformation almost perpendicular to the C-2-C-3 triple bond of the core of the chromophore while Phe78 takes multiple conformations in solution although one of the stable conformations has been assigned for Phe78 in a crystal structure.

[Percutaneous transluminal angioplasty for cervical carotid artery stenosis]

Percutaneous transluminal angioplasty (PTA) was attempted in 16 patients (17 procedures) with cervical internal carotid artery (ICA) stenosis. Among the 16 patients, 14 were male and 2 were female aged from 44 to 76 years (average 63.4 years). One had cerebral infarction on the acute stage, and the other 15 were in the chronic stage. On CT scan and MRI, there were nine multiple lacunar infarctions and seven watershed infarctions. On angiographical findings, 13 had Rt.-ICA stenosis and 4 had Lt. ICA stenosis. Stenotic lesion existed beyond the level of the third cervical vertebral body in eleven cases, and so-called long segmental stenosis ranged from 3 to 5 cervical vertebral bodies in 3 cases. Before PTA, 14 patients underwent a balloon occlusion test for 3 to 20 minutes (average 9 minutes). Neurological symptoms of hemiparesis or sensory disturbance occurred in 3 patients during balloon inflation, but these disappeared completely after balloon deflation. It took from 1.5 to 2 hours (average 1.7 hours) to carry out PTA including the balloon occlusion test. All cases had satisfactory results with no morbidity or mortality. The mean stenosis ratio of pre-PTA, approximately 80% (55-93%), improved to that of 22% (0-50%) after PTA. Bradycardia and hypotension occurred transiently in 9 cases during and after PTA, but no symptoms remained by atropine sulfate and catecholamine infusion intravenously. In the following 1 to 26 months (mean 9.0 months) after PTA, 3 cases restenosed. The restenosis was recognized by MR angiography after 8 to 26 months (average 15.7 months) of PTA.(ABSTRACT TRUNCATED AT 250 WORDS)

The specific inhibition of crystal growth of monohydrogen potassium L-tartrate by d-catechin

Crystal growth of monohydrogen potassium L-tartrate in an ethanolic aqueous solution was specifically inhibited by d-catechin, but not by either its epimeric isomer at C3, l-epicatechin or by gallic acid and caffeic acid. 3D-Structure similarity search of d-catechin with two molecules of the tartrate and docking study of d-catechin with the crystal model of the tartrate suggested that d-catechin mimics a structure consisting of the two tartrate molecules in the inhibition. Differences in the conformation of the catechol moieties of d-catechin and l-epicatechin may explain the distinct inhibitory effects of the epimeric isomers.

[A case of an intracerebral mass lesion consisting of traumatic granulation tissue]

We reported a rare case of an intracerebral granulomatous lesion accompanying severe edema formation in the healing stage of traumatic brain contusions. A 44-year-old male patient came to our outpatient clinic due to progressing headache and nausea. Upon computed tomographic examination, a low density mass with strong surrounding edema was detected at the right frontal base. Magnetic resonance images revealed a high intensity mass on both T1- and T2-weighted images at the right frontal base. Upon intravenous injection of a contrast agent, this lesion exhibited multifocal marginal contrast enhancement. Two additional small enhanced mass lesions were detected at the tip of the right temporal lobe and the medial portion of the left temporal lobe. We tentatively diagnosed it as a right frontal brain tumor and attempted the total removal of the right frontal mass. Unexpectedly, pathological diagnosis was intracerebral granulation tissue associated with accumulation of hemosiderin-laden macrophages and capillary wall thickening. In addition, there was no reactive gliosis. We speculated on the pathogenesis of intracerebral granulation tissue as follows. Since the patient was a heavy drinker and often fell down when he was drunk, it is likely that he might be suffering from intracerebral hematomas due to traumatic contusions. This assumption may be supported by the fact that an old subdural hematoma was observed during the operation and the radiological examination revealed multiple lesions. The gathering and proliferation of mesenchymal cells possibly derived from blood circulation probably began at the site of the damaged brain tissue, thus forming intracerebral granulation tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Evaluation of calcium hydroxide-containing root canal sealers with an improved rabbit ear chamber

An improved rabbit ear chamber was used to evaluate calcium hydroxide-containing root canal sealers on their potential to induce dystrophic calcification in connective tissue. Four sealers and two control materials were introduced into the chambers and the effects of these materials on the living vascular tissue were observed continuously under a biomicroscope up to 9 weeks. Conventional histopathological investigation and examinations with a scanning electron microscope and an X-ray microanalyzer were done to supplement the results. Sealapex and Calvital (Ca(OH)2 + iodoform) revealed almost the same tissue reaction as calcium hydroxide-saline paste; they rapidly made a precipitate-barrier of calcium phosphate in the connective tissue, inducing calcification. However, Dentalis KEZ (ZnO-Ca(OH)2 + eugenol) caused mild disorders of microcirculation without calcification, as well as Canals (ZnO + eugenol). New A (Ca(OH)2 + fatty acid) had good compatibility with microvessels as well as New B (ZnO + fatty acid), however they induced no calcification and disintegrated rapidly in the tissue. These sealers were reclassified according to what they actually bring about in the tissue, not according to what they include.

[Indications for percutaneous transvenous mitral commissurotomy: evaluation according to the Sellors classification]

Fifty-eight consecutive patients underwent percutaneous transvenous mitral commissurotomy (PTMC) for mitral stenosis from August 1987 to June 1990. Patients were divided by echocardiographic characteristics of the mitral valve according to the Sellors classification into three groups: group 1 (mobile cusps, 20 patients), group 2 (thickened cusps, 34 patients), group 3 (rigid cusps, 4 patients). Immediately after PTMC, the mitral valve area increased significantly from 1.41 +/- 0.37 to 2.07 +/- 0.38 cm2 (p < 0.01) in group 1 and from 1.09 +/- 0.21 to 1.64 +/- 0.25 cm2 (p < 0.01) in group 2. The mitral valve area did not increase significantly in group 3 (from 0.82 +/- 0.27 to 1.10 +/- 0.22 cm2). Mitral regurgitation developed or increased in severity in four patients (100%) in group 3 (p < 0.01 vs group 1, 20% and group 2, 21%). The symptomatic improvement was 0% for group 3 (p < 0.01 vs group 1, 90% and group 2, 91%). At follow-up period (mean 24.6 months), symptomatic improvement was maintained in 44 patients (76%) of the total patient population. The mitral valve area was maintained well in group 1 and group 2, but three patients in group 2 showed recurrence of symptoms due to valvular restenosis. PTMC is an effective nonsurgical treatment for patients with mobile or with thickened cusps. Surgical method is preferable for patients with rigid cusps.

The effect of recombinant human erythropoietin (r-HuEPO) on left ventricular mass and left ventricular hemodynamics in hemodialysis patients

The purpose of this study was to examine the effect of recombinant human erythropoietin (r-HuEPO) on left ventricular mass. Twenty-seven hemodialysis patients (13 men and 14 women) were given r-HuEPO for renal anemia. Blood pressure and heart rate were measured before and after the 16-week course of r-HuEPO, and at the same time echocardiography was performed to measure left ventricular dimensions and wall thickness. These measurements were used to calculate left ventricular volume, cardiac output (CO), and left ventricular mass (LVmass). Diastolic blood pressure (DBP) increased after administration of r-HuEPO (from 75.8 +/- 10.8 mmHg to 85.6 +/- 12.7 mmHg), but there was no change in systolic blood pressure (SBP) or heart rate. LVmass increased significantly in seven cases (from 194.7 +/- 40.0 g to 240.3 +/- 47.3 g). These cases, Group I, showed no decline in stroke volume (SV) or CO, and showed significant increases in SBP. In the remaining 20 cases, Group II, LVmass decreased or was unchanged. In this group SV and CO decreased, but there was no increase in SBP. We conclude that increases in LVmass may be associated with elevated systolic blood pressure and hypertrophy of the left ventricular wall, when hemodialysis patients with severe renal anemia are given r-HuEPO.

Better grading systems for evaluating the degree of lymph node invasion in cancer of the thoracic esophagus

To evaluate the quality of various grading systems for lymph node invasion in cancer of the thoracic esophagus, the surgical results of 142 patients who underwent systematic lymph node dissection with curative intent were analyzed. The survival probability of patients in the same grade was modeled using a Weibull distribution and the parameters were estimated by the maximum likelihood principle. The quality of each grading system was measured by the Akaike Information Criterion (AIC) of the estimated statistical model, by which the smaller the AIC of a grading system, the smaller the loss of information for predicting outcomes. The AIC of the TNM grading of the International Union Against Cancer, the grading of the Japanese Society for Esophageal Diseases, and the grading designed according to the total number of positive lymph nodes became substantially smaller in that order. The AIC of grading systems variously designed on rather simple criteria were examined with the aim of creating a better grading system. It was concluded that a grading system based on the total number of positive nodes and the state of the paratracheal and/or middle mediastinal node groups was better than the other systems examined.