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Biomedical subjects

M Takase

Publications and source records attributed to M Takase.

At least 91 records · Page 5Linked to original sources
PubMed1996

[A 83 year-old woman with dementia, gait disturbance, and convulsion].

We report a 83 year-old woman with dementia. She was apparently well until December of 1993 when she was 81-year-old. At that time, she was operated or her cataract. Her post operative course was uneventful, however, shortly after her operation, she had an onset of memory loss and abnormal behavior. She showed a fluctuating course in her mental disturbance. In 1995, her dementia worsened with nocturnal agitation. She was admitted to our service on June 12, 1995. She was alert and her blood pressure was 140/100 mmHg. She showed recent memory loss and disorientation to time. Motor wise, she was unable to stand unsupported. Her gait with support showed small steps and a wide base. She was bradykinetic and ataxic in her finger-to-nose and heel-to-knee test, however, no rigidity or tremor was noted. Her MRI showed T2-high signal lesions in both medial thalamic areas, in the right occipital lobe, and in the bilateral cerebral white matters as well as in the basal ganglia. She was discharged for out-patient follow up on July 3, 1995. Four days after the discharge, she showed declining responses to stimuli and she developed dyspnea on July 14, 1995. She was admitted again on the same day. Her body temperature was 38.5 degrees C and moist rales were heard in the left lung field. She appeared drowsy and no verbal response was obtained; no apparent motor palsy was noted. Blood count showed leukocytosis (14,300/ml). Blood gas analysis under 61 of oxygen inhalation through a mask was as follows: pH 7.460, PCO2 39.6 mmHg, PO2 67 mmHg, and HCO3-28.5 mEq/l. Two days after admission, she developed a convulsion in her left arm and she became unconscious. Her EEG showed periodically recurring lateralized epileptic discharges on the right fronto-central areas. Her subsequent course was complicated by status epilepticus and respiratory distress. She died on July 26, 1995. She was discussed in a neurological CPC. The chief discussant arrived at a conclusion that she suffered from multi-infarct dementia. Bilateral thalamic infarctions were considered to have played a significant role in her dementia. Post-mortem examination revealed subcortical leukoencephalopathy of Binswanger's type and cerebral infarctions in the thalamic and basal ganglia regions and in the right occipital lobe. In addition, she showed isolated angitis of the central nervous system involving mainly in the small arteries located in the superficial areas of the brain and the spinal cord. This patient was interesting in that despite relatively mild leukoaraiosis in MRI, post-mortem examination revealed profound pathologic changes in the subcortical white matters. In addition, she showed the isolated angitis of the CNS. The cause and the clinical correlates of her angitis were unclear.

Aged↗
PubMed1995

[Transcranial magnetic stimulation of the accesory nerve--investigation of the site and mechanism of excitation in the cat].

The site where transcranial magnetic stimulation excites the accessory nerve was studied in 5 cats. Transcranial magnetic stimulation of the accessory nerve was recorded from the right trapezius. The accessory nerve was stimulated electrically at the C1 level, jugular tubercle and jugular foramen. The latencies of the compound muscle action potentials (CMAPs) for each portion were measured and compared with the magnetic response, which was coincidental with that of the jugular tubercle. The accessory nerve was then transected in steps distally from the C1 level, and CMAPs following magnetic stimulation were recorded at each step. The CMAPs disappeared following the nerve transection at the jugular tubercle. The results of both approaches in this study conclude that transcranial magnetic stimulation excites the accessory nerve at jugular tubercle. This stimulation site was anatomically coincidental with that of the facial nerve and trigeminal nerve in being right before the point where the nerve bends. Following the accessory nerve transection at the C1 level, the amputation stump was moved cranially, and CMAPs disappeared. CMAPs recorded after the accessory nerve was returned to its original position. These examinations suggested that sudden alteration of the traveling lie of the nerve participates in the mechanism of transcranial magnetic stimulation.

Accessory Nerve↗
PubMed1994

Lactoferrin inhibits cholesterol accumulation in macrophages mediated by acetylated or oxidized low-density lipoproteins.

When macrophages are incubated with acetylated or oxidized low-density lipoproteins (Ac- or OxLDL), cellular cholesteryl esters (CE) increase significantly. In the present study, we investigated the effect of whey protein on Ac- or OxLDL mediated accumulation of CE in macrophages and found that lactoferrin (Lf), a minor protein component of whey, inhibits the accumulation of CE dose-dependently. In the presence of bovine Lf (1 mg/ml), CE accumulation in macrophages incubated with AcLDL (100 micrograms of protein/ml) decreased by more than 80%. Human Lf was less potent than bovine Lf, and bovine transferrin had no effect. Binding of 125I-AcLDL to macrophages was also inhibited by Lf. Agarose gel electrophoresis revealed that Lf binds to Ac- or OxLDLs and neutralizes their negative charges. These results indicate that Lf inhibits the binding of modified LDLs to macrophages by direct interaction with modified LDLs, resulting in their loss of function as ligands of the scavenger receptor. Modification of the arginine residues of Lf with 1,2-cyclohexanedione abolished its ability to bind to AcLDL, suggesting that a region rich in basic amino acid residues near the N-terminus of Lf, which resembles the ligand-binding site of the scavenger receptor, may be responsible for this binding ability. As a result, the inhibitory effect of Lf on CE accumulation in macrophages was significantly weakened by this modification. Our results suggest the possibility that Lf in the blood stream may act as an anti-atherogenic agent in vivo.

Amino Acid Sequence↗
PubMed1994

Antimicrobial peptides of lactoferrin.

Lactoferrin was found to contain an antimicrobial sequence near its N-terminus which appears to function by a mechanism distinct from iron chelation. Antimicrobial peptides representing this domain were isolated following pepsin cleavage of human lactoferrin and bovine lactoferrin. The antimicrobial sequence was found to consist mainly of a loop of 18 amino acid residues formed by a disulfide bond between cysteine residues 20 and 37 of human lactoferrin, or 19 and 36 of bovine lactoferrin. The identified domain contains a high proportion of basic residues, like various other antimicrobial peptides known to target microbial membranes and it appears to be located on the surface of the folded protein allowing its interaction with surface components of microbial cells. The isolated domain, "lactoferrin", was shown to have potent broad spectrum antimicrobial properties and its effect was lethal causing a rapid loss of colony-forming capability. Such evidence points to the conclusion that this domain is the structural region responsible for the microbicidal properties of lactoferrin. The evidence also suggests the possibility that active peptides produced by enzymatic digestion of lactoferrin may contribute to the host defense against microbial disease.

Amino Acid Sequence↗
PubMed1994

Physicochemical and antibacterial properties of lactoferrin and its hydrolysate produced by heat treatment at acidic pH.

In order to apply functionally active lactoferrin (Lf) to food products, the effect of pH on the heat stability of Lf was studied. Lf was easily denatured to an insoluble state by heat treatment under neutral or alkaline conditions, above pH 6. In contrast, it remained soluble after heat treatment under acidic conditions at pH 2 to 5, and the HPLC pattern of Lf heat-treated at pH 4 at 100 degrees C for 5 min was the same as that of native Lf. Lf was found to be very thermostable at pH 4, and could be pasteurized or sterilized without any significant loss of its physicochemical properties. Lf was hydrolyzed by heat treatment at pH 2 to 3 at above 100 degrees C, and its iron binding capacity and antigenicity were lost. But the antibacterial activity of the hydrolysate was found to be much stronger than that of native Lf. The antibacterial component of Lf hydrolysate produced by heat treatment at acidic pH was verified to be a peptide including the sequence of residues 1-54 from the N-terminal end of the bovine Lf molecule.

Amino Acid Sequence↗
PubMed1994

Lactoferrin promotes nerve growth factor synthesis/secretion in mouse fibroblast L-M cells.

Fibroblast cells are known to have an ability to synthesize and secrete nerve growth factor (NGF). To investigate the mechanism of action of the iron-binding protein, lactoferrin (Lf), on cultured animal cells, the effect of bovine Lf (bLf) on NGF synthesis/secretion in mouse fibroblast cells was examined. Both apo- and holo-bLf induced an increase in NGF content in the cell-conditioned medium(CM) of mouse L-M cells, a line derived from L929 fibroblast cells, with similar effectiveness. The increase in NGF content in the CM of L-M cells cultured with bLf was not dependent on the induction of increase in cell numbers, but was due to induction of de novo synthesis of NGF in individual cells by bLf. Human Lf(hLf) also increased NGF content. However, apo- and holo-bovine transferrin (bTf) failed to stimulate the NGF synthesis. The time-dependent induction of NGF in L-M cells by bLf was different from that induced by basic fibroblast growth factor (bFGF) and bLf showed an additive effect with bFGF. These results suggest that the induction of NGF synthesis depends on a mechanism different from iron transport or bFGF.

Animals↗
PubMed1994

A review: the active peptide of lactoferrin.

A potent antimicrobial peptide, 'lactoferricin', was found to be generated upon gastric pepsin cleavage of lactoferrin. The active peptide consists mainly of a loop of 18 amino acid residues, derived from the N-terminal region of the lactoferrin molecule. Like various other antimicrobial peptides that display membrane-disruptive properties, it contains a high proportion of basic amino acid residues. A physiologically diverse range of micro-organisms was tested and found to be susceptible to inhibition by this natural peptide including Gram-negative and Gram-positive bacteria, yeasts and filamentous fungi. Its antimicrobial effect against sensitive micro-organisms was lethal. Electron microscopy studies revealed that it induces a profound change in cell ultrastructural features and causes substantial cell damage in bacteria and fungi. These findings suggest the possibility that active peptides of lactoferrin may have a role in the host defense against microbial disease. If produced in substantial quantities in vivo such peptides could have important physiological significance, especially in nursing infants.

Amino Acid Sequence↗
PubMed1994

Localization and purification of serum albumin in the testis of Xenopus laevis.

The distribution of serum albumin is of interest in the Xenopus (X.) laevis testis, since albumin is probably a major protein that binds testosterone (T) in the plasma and interstitial fluid. This study was undertaken to determine the localization and purification of serum albumin in the X. laevis testis. The interstitial tissue and spermatogenia immunoreacted strongly with a sheep antiserum raised against X. laevis albumin. A weak staining was also seen in spermatocytes and early spermatids, but there was no staining in Sertoli cells. In order to clarify whether serum albumin was really localized on the surface of testicular cells in the X. laevis testis, a membrane-rich fraction was prepared from testes and extracted with 0.6 M KCl. The KCl extract was then subjected to gel filtration, ammonium sulfate precipitation and high-performance liquid chromatography (HPLC). A protein with M(r) = 74 kD was obtained by this procedure and its NH2-terminal amino acid sequence was determined. The sequence of the first 19 amino acids was DTDADXXKXIADVYTALTE, suggesting that this protein was identical to serum albumin (M(r) = 74 kD). When the membrane fraction of blood cells in this animal was handled in the same manner, no appreciable amount of albumin was detected. These results suggest that the 74 kD serum albumin, possibly associated with bound T, may play an important role in the differentiation of germ cells during spermatogenesis of X. laevis testis.

Amino Acid Sequence↗
PubMed1994

[Neurophysiological study of hemifacial spasm--F wave of the facial muscles].

We studied the F wave of the facial muscles on both the normal side and the spastic side in 14 patients with hemifacial spasm. The purpose of this study was to determine if the mechanism of hemifacials spasm originates in ephaptic transmission in the facial nerve at the site of vascular compression or in a hyperexcited facial motor nucleus. Larger amplitude, longer duration and shorter latency F waves in the peripheral nerves than in normals indicate anterior horn cell hyperexcitability. We found abnormal potentials exhibiting synkinesis (lateral spread), a typical electrophysiological finding in hemifacial spasm, in the facial nerve evoked electromyograms of the 14 patients, none of whom had experienced facial palsy or facial nerve block. Electrical stimulation was delivered transcutaneously to the most distal portion of the marginal mandibular branch of the facial nerve. Using surface electrodes the F waves were obtained over the mentalis muscle as the second response after the M wave. While the F waves were normal on the patients' normal side, on the spastic side, their duration was longer (mean duration about 1.9 times that of the normal side), their onset latency was slightly shorter, and their F/M amplitude latency was greater than on the normal side. After microvascular decompression, the facial spasm and abnormal F-wave findings resolved. Onset latency was not increased, and on the spastic side some patients displayed facial spasm clinically and electrophysiologically for one year after MVD. In other words, there was hardly any focal demyelination of the facial nerve, so it is possible that ephaptic transmission and ectopic excitation are the mechanism of HFS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Effects of a novel thyrotropin-releasing hormone analogue, JTP-2942, on extracellular acetylcholine and choline levels in the rat frontal cortex and hippocampus.

The effects of a novel thyrotropin-releasing hormone (TRH) analogue, N alpha-[(1S,2R)-2-methyl-4-oxocyclopentanecarbonyl]-L-histidyl-L-pr olinamide (JTP-2942) on acetylcholine (ACh) release and on the extracellular choline level were investigated in rat frontal cortex and hippocampus by microdialysis, and were compared with effects of TRH. JTP-2942 (0.3 mg/kg i.p.) produced a marked (> 300%) and persistent increase of ACh release in both the frontal cortex and hippocampus, while TRH (3 mg/kg i.p.) caused a significant but transient increase of ACh to about 200% in the frontal cortex. Both drugs significantly decreased the choline levels in both brain regions. Investigation of the effects of JTP-2942 (0.001-1 mM) and TRH (1 and 10 mM) on ACh release and choline levels when perfused through the dialysis probe revealed that JTP-2942 had a greater effect than TRH in both the frontal cortex and the hippocampus. The action of JTP-2942 was about 1000-fold more potent than that of TRH in both brain regions. Oral administration of JTP-2942 at a dose of 10 mg/kg markedly and persistently increased the release of ACh and at doses of 1-10 mg/kg decreased the extracellular choline level in the frontal cortex and hippocampus. These results also suggest that JTP-2942 has some selectivity for the hippocampus compared to the frontal cortex after both systemic administration and local injection. The increase of ACh release caused by JTP-2942 was completely antagonized by perfusion with tetrodotoxin (TTX, 1 microM), suggesting that the action of JTP-2942 on cholinergic neurons was mediated via neuronal activity.

Acetylcholine↗
PubMed1993

Killing of Candida albicans by lactoferricin B, a potent antimicrobial peptide derived from the N-terminal region of bovine lactoferrin.

Candida albicans was found to be highly susceptible to inhibition and inactivation by lactoferricin B, a peptide produced by enzymatic cleavage of bovine lactoferrin. Effective concentrations of the peptide varied within the range of 18 to 150 micrograms/ml depending on the strain and the culture medium used. Its effect was lethal, causing a rapid loss of colony-forming capability. 14C-labeled lactoferricin B bound to C. albicans and the rate of binding appeared to be consistent with the rate of killing induced by the peptide. The extent of binding was diminished in the presence of Mg2+ or Ca2+ ions which acted to reduce its anticandidal effectiveness. Binding occurred optimally at pH 6.0 and killing was maximal near the same pH. Such evidence suggests the lethal effect of lactoferricin B results from its direct interaction with the cell surface. Cells exposed to lactoferricin B exhibited profound ultrastructural damage which appeared to reflect its induction of an autolytic response. These findings suggest that active peptides of lactoferrin could potentially contribute to the host defense against C. albicans.

Amino Acid Sequence↗
PubMed1993

A gene, SMP2, involved in plasmid maintenance and respiration in Saccharomyces cerevisiae encodes a highly charged protein.

The smp2 mutant of Saccharomyces cerevisiae shows increased stability of the heterologous plasmid pSR1 and YRp plasmids. A DNA fragment bearing the SMP2 gene was cloned by its ability to complement the slow growth of the smp2 smp3 double mutant (smp3 is another mutation conferring increased stability of plasmid pSR1). The nucleotide sequence of SMP2 indicated that it encodes a highly charged 95 kDa protein. Disruption of the genomic SMP2 gene resulted in a respiration-deficient phenotype, although the cells retained mitochondrial DNA, and showed increased stability of pSR1 like the original smp2 mutant. The fact that the smp2 mutant is not always respiration deficient and shows increased pSR1 stability even in a rho0 strain lacking mitochondrial DNA suggested that the function of the Smp2 protein in plasmid maintenance is independent of respiration. The SMP2 locus was mapped at a site 71 cM from lys7 and 21 cM from ilv2/SMR1 on the right arm of chromosome XIII.

Amino Acid Sequence↗
PubMed1993

Relationship between clinical symptoms and EEG findings in borderline personality disorder.

Borderline personality disorder (BPD) was diagnosed in female patients (N = 41) between the ages of 18 and 30 using the Diagnostic Interview for Borderline Patients (DIB) and DSM-III. Comparing the EEG findings of BPD (N = 18) and non-BPD (N = 21) groups, there were no EEG findings characteristic of BPD. We also assessed the relationship between the EEG findings and DIB items. Positive spikes appeared in patients with high scores for Impulse Action Patterns, while wave and spike phantoms were observed in patients with high scores for Interpersonal Relations. Dividing the patients into BPD and non-BPD groups, a similar tendency to that observed from an analysis of all patients was observed in the non-BPD group, but no such tendency was observed in the BPD group. The results suggest that BPD patients include those in whom vulnerability of cerebral function plays an important role in the development of these two clinical symptoms as well as those in whom vulnerability of cerebral function plays almost no pathogenic role.

Adult↗
PubMed1993

MKK1 and MKK2, which encode Saccharomyces cerevisiae mitogen-activated protein kinase-kinase homologs, function in the pathway mediated by protein kinase C.

The PKC1 gene of Saccharomyces cerevisiae encodes a homolog of mammalian protein kinase C that is required for normal growth and division of yeast cells. We report here the isolation of the yeast MKK1 and MKK2 (for mitogen-activated protein [MAP] kinase-kinase) genes which, when overexpressed, suppress the cell lysis defect of a temperature-sensitive pkc1 mutant. The MKK genes encode protein kinases most similar to the STE7 product of S. cerevisiae, the byr1 product of Schizosaccharomyces pombe, and vertebrate MAP kinase-kinases. Deletion of either MKK gene alone did not cause any apparent phenotypic defects, but deletion of both MKK1 and MKK2 resulted in a temperature-sensitive cell lysis defect that was suppressed by osmotic stabilizers. This phenotypic defect is similar to that associated with deletion of the BCK1 gene, which is thought to function in the pathway mediated by PCK1. The BCK1 gene also encodes a predicted protein kinase. Overexpression of MKK1 suppressed the growth defect caused by deletion of BCK1, whereas an activated allele of BCK1 (BCK1-20) did not suppress the defect of the mkk1 mkk2 double disruption. Furthermore, overexpression of MPK1, which encodes a protein kinase closely related to vertebrate MAP kinases, suppressed the defect of the mkk1 mkk2 double mutant. These results suggest that MKK1 and MKK2 function in a signal transduction pathway involving the protein kinases encoded by PKC1, BCK1, and MPK1. Genetic epistasis experiments indicated that the site of action for MKK1 and MKK2 is between BCK1 and MPK1.

Amino Acid Sequence↗
PubMed1993

Double-masked comparative study of UF-021 and timolol ophthalmic solutions in patients with primary open-angle glaucoma or ocular hypertension.

A double-masked comparative clinical study of UF-021 (Rescula), a unique prostaglandin-related compound, was carried out at 18 centers with timolol maleate 0.5% ophthalmic solution as an active reference drug. After a wash-out period, UF-021 (0.12%) or timolol (0.5%) was given topically twice a day for 12 weeks to 158 patients with primary open-angle glaucoma or ocular hypertension, in a randomized double-masked manner. Both groups showed a significant reduction in intraocular pressure from the second week to the end of the study. In overall improvement rating, 91.4% of the cases (64/70) in the UF-021 group and 88.3% (68/77) in the timolol group were judged to be "Extremely improved" or "Improved". Five and 4 cases reported having side effects in the UF-021 and timolol groups, respectively, but none of the cases required any change or discontinuation of treatment. While UF-021 did not affect blood pressure, both systolic and diastolic blood pressures in the timolol group were significantly decreased. These results suggest that UF-021 (0.12%) has the potential to lower intraocular pressure equivalent to timolol (0.5%), while having no effect on cardiovascular functions.

Administration, Topical↗
PubMed1993

Lysozyme in cervical mucus of patients with chorioamnionitis.

Lysozyme and lactoferrin, antimicrobial substances present in cervical mucus, play an important role in defense mechanisms against ascending infections in development of chorioamnionitis (CAM). In this study, we measured the concentration of lysozyme in cervical mucus, and studied its relationship with other factors, and obtained following results. The concentration of lysozyme in cervical mucus decreased more significantly in positive CAM in preterm labor than in negative CAM and control subjects (P < 0.001). A direct correlation between the concentrations of lysozyme and lactoferrin was observed (r = 0.709). In positive CAM, the concentration of elastase in cervical mucus reached a significantly high level (more than 8,000 micrograms/L), and a no correlation between the concentrations of elastase and lysozyme was observed. These findings suggest a reduction of the defense mechanism occurred because the concentrations of both lysozyme and lactoferrin in cervical mucus during preterm labor (positive CAM) decreased.

Cervix Mucus↗
PubMed1993

Role of cell-binding in the antibacterial mechanism of lactoferricin B.

The antibacterial cell-binding properties of lactoferricin B, a potent bactericidal peptide derived from bovine lactoferrin, were investigated for the first time. To facilitate measurements of binding the peptide was radiolabelled by reduction and treatment with iodo-[1-14C]acetamide. 14C-lactoferricin B bound rapidly to the surface of Escherichia coli and Bacillus subtilis. The rate of binding was consistent with the rapid rate of killing caused by this peptide. The extent of binding was reduced in the presence of Mg2+ or Ca2+ ions which act to reduce its antimicrobial effectiveness. The optimal pH for binding was strain-dependent and the killing effect was maximal near the optimal pH for cell binding with each strain tested. These observations indicate that direct interaction of lactoferricin B with the cell surface is necessary for its lethal effect. The number of peptide molecules bound (> 10(6) per cell) was more than would be expected for binding to specific protein receptors. Lactoferricin B inhibited bacterial uptake of 3H-proline with effectiveness similar to polymyxin B, a known membrane-disruptive agent. The cell-binding event appears to lead to a disruption of normal permeability functions of the cytoplasmic membrane.

Anti-Bacterial Agents↗