Biomedical subjects

T Goto

Publications and source records attributed to T Goto.

At least 469 records · Page 26Linked to original sources

PubMed1994

Localization of cathepsins B, D, and L in the rat osteoclast by immuno-light and -electron microscopy.

The localization of cathepsins B, D, and L was studied in rat osteoclasts by immuno-light and -electron microscopy using the avidin-biotin-peroxidase complex (ABC) method. In cryosections prepared for light microscopy, immunoreactivity for cathepsin D was found in numerous vesicles and vacuoles but was not detected along the resorption lacunae of osteoclasts. However, immunoreactivity for cathepsins B and L occurred strongly along the lacunae, and only weak intracellular immunoreactivity was observed in the vesicles and peripheral part of the vacuoles near the ruffled border. In control sections that were not incubated with the antibody, no cathepsins were found in the osteoclasts or along the resorption lacunae of osteoclasts. At the electron microscopic level, strong intracellular reactivity of cathepsin D was found in numerous vacuoles and vesicles, while extracellular cathepsin D was only slightly detected at the base of the ruffled border but was not found in the eroded bone matrix. Most osteoclasts showed strong extracellular deposition of cathepsins B and L on the collagen fibrils and bone matrix under the ruffled border. The extracellular deposition was stronger for cathepsin L than for cathepsin B. Furthermore cathepsins B and L immunolabeled some pits and part of the ampullar extracellular spaces, appearing as vacuoles in the sections. Conversely, the intracellular reactivity for cathepsins B and L was weak: cathepsin-containing vesicles and vacuoles as primary and secondary lysosomes occurred only sparsely. These findings suggest that cathepsins B and L, unlike cathepsin D, are rapidly released into the extracellular matrix and participate in the degradation of organic bone matrix containing collagen fibrils near the tip of the ruffled border.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Pentobarbitone, but not propofol, produces pre-emptive analgesia in the rat formalin model.

Injection of formalin into the hindpaw of a rat induces a biphasic response in pain-related behaviours, such that C-fibre activation during phase 1 triggers a state of central sensitization characterized by a longer lasting phase 2. As the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) may participate in processing of nociceptive inputs, we hypothesized that pentobarbitone and propofol, i.v. anaesthetics with known GABAA agonist properties, would interfere with development of central sensitization and thereby modify the phase 2 hyperalgesic response. Pentobarbitone administered i.v. before injection of formalin produced dose-dependent suppression of phase 2, even though animals had recovered from anaesthesia, whereas it had substantially less effect when given after phase 1 had resolved. Picrotoxin, a GABAA antagonist, reversed the effect of pentobarbitone on phase 2 pain behaviour but was itself a mild analgesic. In contrast, propofol had no effect on phase 2 formalin-induced pain behaviour. Thus we conclude that pentobarbitone, but not propofol, produced pre-emptive analgesia in this model, presumably by suppressing noxious stimulation-induced central sensitization via activation of GABAA receptors.

Analgesics↗

PubMed1994

Amino acid sequence of porcine antithrombin III.

Antithrombin III (ATIII) is a member of the serine protease inhibitor (serpin) family. As a step towards a better understanding of the heparin-binding mechanism of mammalian ATIIIs, the amino acid sequence of porcine ATIII was established by sequence analysis of the peptides derived from cyanogen bromide cleavage and enzymatic digestion with lysyl endopeptidase, V8 protease, and trypsin. Porcine ATIII was found to consist of 431 amino acid residues, with a calculated molecular weight of 48,930 without carbohydrate. Its molecular weight with 16.4% carbohydrate was estimated as 56,955, which is in good agreement with the value determined by SDS-PAGE. Porcine ATIII showed high sequence similarity to other mammalian ATIIIs, including the reactive site, heparin-binding basic amino acid residues, and disulfide bonds. The most notable feature of porcine ATIII was that it possesses only three carbohydrate chains, at Asn136, 156, and 193, whereas other mammalian ATIIIs have four, additional chain being at Asn97; this is replaced by Asp in porcine ATIII. In the case of human ATIII, the chains are at Asn96, 135, 155, and 192. The heparin-binding affinities of human and porcine ATIIIs were compared using an immobilized heparin column. Porcine ATIII eluted from the column with a peak at an NaCl concentration of 924 mM while human ATIII eluted at 838 mM NaCl. Neuraminidase treatment of each ATIII enhanced the heparin-affinity to the same extent. These results suggest that in spite of the high degree of amino acid sequence identity between porcine and human ATIIIs (91% identical), porcine ATIII has a higher heparin-binding affinity than human, because it lacks a carbohydrate chain at Asp97.

Amino Acid Sequence↗

PubMed1994

Nitrous oxide induces preemptive analgesia in the rat that is antagonized by halothane.

BACKGROUND: Noxious stimulation-induced sensitization of the central nervous system has been proposed as a key element in the development of subsequent protracted pain. Accordingly, the authors used the formalin model of pain to test the hypothesis that general anesthesia can produce preemptive analgesia and thereby interfere with noxious stimulation-induced central sensitization. METHODS: Rats received 0.9% or 1.8% halothane, 30% or 75% nitrous oxide (N2O), or 75% N2O plus 0.9% halothane (n = 4 or 5 per group). Control rats (n = 5) received only 100% oxygen. Fifteen minutes after the induction of anesthesia, formalin was injected subcutaneously into a hind paw of each rat, and anesthesia was maintained for 5 more min. Because the behavioral pain response to formalin (i.e., flinching of the injected paw) is biphasic, these treatment groups were anesthetized only during phase 1 (acute phase). Another group (n = 5) received 75% N2O only during phase 2 (delayed phase). Reversibility of the N2O effect was tested by the administration of naloxone before phase 1 or naltrexone during phase 2 (n = 5 per group). Finally, additional rats anesthetized as described above (n = 4 or 5 per group) underwent tail-flick testing during anesthesia. RESULTS: All anesthetics reduced phase 1 pain behavior, but only N2O produced antinociception on tail-flick testing. Thirty percent and 75% N2O, administered during phase 1, suppressed phase 2 flinching 29% and 49%, respectively, whereas nitrous oxide administered after phase 1 did not suppress phase 2 pain behavior. This effect of nitrous oxide was reversed by an opioid antagonist given during phase 1 but not phase 2. Halothane administered during phase 1 had no effect on phase 2 flinching, and it antagonized the effect of 75% N2O. CONCLUSIONS: Nitrous oxide induces dose-dependent preemptive analgesia in this model that is reversed partially by naloxone, thus suggesting the involvement of endogenous opioids in this action. In contrast, halothane has no preemptive analgesic properties and even antagonizes the analgesic effect of nitrous oxide. Hence, the hypnotic potency of an anesthetic is a poor indication of its preemptive analgesic potential.

Analgesia↗

PubMed1994

Subarachnoid morphine reduces stimulation-induced but not basal expression of preproenkephalin in rat spinal cord.

BACKGROUND: To evaluate directly the possibility that the potent exogenous opioid analgesic morphine may alter neuronal expression of opioid peptide genes, we assessed the effect of subarachnoid morphine on basal and noxious stimulation-induced expression of preproenkephalin in spinal cord neurons. METHODS: Twenty male Sprague-Dawley rats were prepared 48 h in advance with lumbar subarachnoid catheters. In the first phase, basal expression was evaluated in rats that received morphine 10 micrograms or saline intrathecally (n = 5 per group). Subsequently, the experiment was repeated (n = 5 per group), except that 10 min after morphine or saline administration rats received a hindpaw footpad injection of 50 microliters 5% formalin. Rats were killed during pentobarbital anesthesia 2 h later, and messenger RNA transcribed from preproenkephalin was measured in lumbar spinal cord with quantitative in situ hybridization with a complementary sulfur 35-labeled oligonucleotide probe and emulsion autoradiography. RESULTS: In control (nonstimulated) rats, 20% of the neurons in laminae I-II and 10% of those in laminae III-IV expressed preproenkephalin. Injection of formalin increased the fraction of positive neurons by 34% (P < 0.05) and 20% (P < 0.05) in laminae I-II and V-VI, respectively, but had no effect on expression in laminae III-IV. Subarachnoid morphine did not alter basal expression of preproenkephalin but markedly attenuated the noxious stimulation-induced increase in laminae I-II (P < 0.01) and V-VI (P < 0.05) by preventing the stimulation-evoked recruitment of preproenkephalin-expressing neurons that otherwise would have occurred. CONCLUSIONS: Subarachnoid morphine does not acutely alter basal expression of preproenkephalin in spinal cord neurons but inhibits the increase in preproenkephalin expression that would otherwise occur after noxious stimulation.

Animals↗

PubMed1994

Effects of strong pulsed magnetic fields on the cardiac activity of an open chest dog.

The heart of an open chest dog was stimulated by strong magnetic fields which were damped sinusoidal pulses with the one-cycle period of 1.47 ms. Stimulation effects were detected by electrocardiograph (ECG) and arterial blood pressure as a function of the strength of the field, the triggering point in the cardiac cycle, and the position of a stimulating coil. The threshold for arrhythmias was a minimum for the stimuli triggered at the apex of the T wave and on the P wave in the ECG. Premature ventricular and premature atrial contractions occurred according to whether the coil was placed over the ventricles or the atria. Ventricular defibrillation can not be attained by the magnetic stimulus with the flux density of 9.2 T which was the maximum field used.

Animals↗

PubMed1994

Development and characterization of chimeric anti-carcinoembryonic antigen monoclonal antibodies and their Fab fragments.

In an attempt to reduce the immunogenicity of two different murine anti-carcinoembryonic antigen (CEA) monoclonal antibodies (MAbs), KM10 and A10, we produced recombinant mouse/human chimeric MAbs and the respective Fab fragments carrying the variable regions of the murine MAbs. Chimeric A10 Fab fragment was expressed in Escherichia coli, and produced in large quantities in a mini-jar fermentation system. In competitive binding assays, chimeric MAbs and their Fab fragments showed identical specificity to human CEA epitopes, as compared to the parental MAbs or Fab fragments. Both chimeric Fab fragments exhibited strong immunohistochemical reactivity with various gastrointestinal carcinomas and no reactivity with CEA-related antigens, such as NCA (nonspecific cross-reacting antigen) or BGPI (biliary glycoprotein I). Furthermore, chimeric KM10 MAb elicited substantially higher antibody-dependent cellular cytotoxicity than the murine MAb. Complement-dependent cytotoxicity in vitro was much weaker with chimeric KM10 MAb. These results indicate that chimeric MAbs or Fab fragments could potentially replace the parental murine antibodies or their Fab fragments in therapy or diagnosis of human gastrointestinal carcinomas.

Animals↗

PubMed1994

Cellular origin and extent of clonal involvement in multiple myeloma: genetic and phenotypic studies.

The cellular origin and extent of clonal involvement in multiple myeloma (MM) are controversial. The third-complementarity-determining region (CDR3) of the immunoglobulin heavy chain gene is the target region of VH replacements and somatic mutations. We analysed the CDR3 sequences of myeloma cells from eight newly diagnosed and three relapsed patients in order to elucidate the target cell of malignant transformation in MM. We also examined the extent of clonal involvement in MM using a CDR3 clone-specific nucleic acid probe. The peripheral lymphocytes from the five MM patients were separated into fractions such as CD34+, CD20+CD10+, CD20+CD21+, CD20+CD19- and CD2+ cells. Amplified CDR3 DNAs from these subpopulations were hybridized with the probe specific to each patient's tumour cells. We found no evidence of ongoing VH replacements or somatic mutations in CDR3 in MM. However, frequent nucleotide mutations in D and JH segments were observed. Circulating malignant cells were detected in the CD34+ and all of the CD20+ subpopulations, but not in the CD2+ fraction. MM is a neoplasm originating from a B-lineage cell which has already undergone antigen-dependent selection. Nevertheless, the tumour cells are composed of heterogeneous subpopulations at various stages of differentiation, similar to normal B-lineage cells. Conversely, T cells were not involved in MM. These results imply that there is an analogous developmental pathway between the normal B-lineage cells and the tumour cells of MM.

Aged↗

PubMed1994

Endotoxin levels in sera of elderly individuals.

The endotoxin levels in serum of 377 72-year-old individuals were quantitated. The study population was a representative sample of this age group and was participating in a general study of health and disease among the elderly in Göteborg, Sweden. The endotoxin levels in serum were quantified by the chromogenic Limulus amebocyte lysate assay and were correlated with the health status and laboratory findings for each individual. The mean endotoxin levels (+/- 1 standard deviation) in men and women, when excluding four outliers, were 6.6 +/- 3.8 and 6.9 +/- 3.8 pg/ml, respectively. All included, 21.5% of individuals had endotoxin levels equal to or above the sensitivity limit of 10 pg/ml. Strong positive correlations were found between endotoxin levels and plasma triglycerides (P > 0.995) and between endotoxin levels and serum protein (P > 0.9875). The endotoxin activity also correlated with mean corpuscular hemoglobin concentration (P < 0.005, negative correlation), body mass index (P > 0.9875), and decreased appetite (P > 0.9875). A high alcohol consumption was associated with increased endotoxin levels (P = 0.995). There are no previous studies which examine endotoxin levels in serum samples from individuals representative of the population. This study showed that elderly individuals had the same mean level of endotoxin as has been found in other age groups. The increased endotoxin levels seen in heavy drinkers may be explained by a decreased ability of the liver to remove endotoxin. The correlations found between endotoxin and triglycerides, protein, mean corpuscular hemoglobin concentration, decreased appetite, and body mass index are discussed.

Aged↗

PubMed1994

The human T-cell leukemia virus type I Tax protein induces apoptosis which is blocked by the Bcl-2 protein.

The Tax protein of human T-cell leukemia virus type I activates transcription of cellular and viral genes and can immortalize primary T lymphocytes. We have previously reported that the Tax protein transforms Rat-1 cells. Here we show that Tax-transformed Rat-1 cells detach from plates to undergo apoptotic cell death by serum deprivation. These cells exhibit DNA fragmentation into oligonucleosomal fragments and chromatin condensation. Constitutive expression of a proto-oncogene, bcl-2, effectively blocks Tax-mediated apoptosis caused by serum deprivation without affecting the levels of Tax expression and the transformed phenotype of the cells.

Animals↗

PubMed1994

Synthesis and antiulcer activities of novel 2-[(6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridin-9-yl)sulfinyl]-1H- benzimidazole analogues.

A synthetic study on a series of benzimidazole derivatives including cycloalka[b]pyridine moiety has been carried out. Among these compounds synthesized, a novel antipeptic agent with 6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine moiety (TY-11345) was found to be superior to omeprazole in (H+ + K+)-ATPase inhibitory activity and antisecretory potencies.

Animals↗

PubMed1994

Action of FR901228, a novel antitumor bicyclic depsipeptide produced by Chromobacterium violaceum no. 968, on Ha-ras transformed NIH3T3 cells.

FR901228, a novel antitumor antibiotic, reversed the transformed morphology of the Ha-ras transformants, Ras-1 cells, and inhibited their growth. The reduction of c-myc expression was observed in FR901228-treated Ras-1 cells by RNA dot-blot hybridization. This reduction of c-myc expression and morphological reversion of the transformed cells to normal were correlated with growth inhibition (G0/G1 arrest in cell cycle).

3T3 Cells↗

PubMed1994

The significance of right ventricular ischemia in reflex bradycardia in humans.

Heart rates (HR) were measured before (control HR) and after (ischemic HR) balloon inflation during percutaneous transluminal coronary angioplasty in 96 patients with effort angina pectoris. The delta HR, defined as (ischemic HR-control HR), in the right coronary artery occlusion was significantly smaller than that in the left anterior descending artery or left circumflex artery occlusion. Among right coronary artery occlusions the delta HR in segment 1 occlusion was significantly smaller than that in segment 2 or segment 3 occlusion. It is suggested that the ischemia of the right ventricle plays an important role in producing a reflex bradycardic response in humans.

Angina Pectoris↗

PubMed1994

Mesenchymal cell-based repair of large, full-thickness defects of articular cartilage.

UNLABELLED: Osteochondral progenitor cells were used to repair large, full-thickness defects of the articular cartilage that had been created in the knees of rabbits. Adherent cells from bone marrow, or cells from the periosteum that had been liberated from connective tissue by collagenase digestion, were grown in culture, dispersed in a type-I collagen gel, and transplanted into a large (three-by-six-millimeter), full-thickness (three-millimeter) defect in the weight-bearing surface of the medial femoral condyle. The contralateral knee served as a control: either the defect in that knee was left empty or a cell-free collagen gel was implanted. The periosteal and the bone-marrow-derived cells showed similar patterns of differentiation into articular cartilage and subchondral bone. Specimens of reparative tissue were analyzed with use of a semiquantitative histological grading system and by mechanical testing with employment of a porous indenter to measure the compliance of the tissue at intervals until twenty-four weeks after the operation. There was no apparent difference between the results obtained with the cells from the bone marrow and those from the periosteum. As early as two weeks after transplantation, the autologous osteochondral progenitor cells had uniformly differentiated into chondrocytes throughout the defects. This repair cartilage was subsequently replaced with bone in a proximal-to-distal direction, until, at twenty-four weeks after transplantation, the subchondral bone was completely repaired, without loss of overlying articular cartilage. The mechanical testing data were a useful index of the quality of the long-term repair. Twenty-four weeks after transplantation, the reparative tissue of both the bone-marrow and the periosteal cells was stiffer and less compliant than the tissue derived from the empty defects but less stiff and more compliant than normal cartilage. CLINICAL RELEVANCE: The current modalities for the repair of defects of the articular cartilage have many disadvantages. The transplantation of progenitor cells that will form cartilage and bone offers a possible alternative to these methods. As demonstrated in this report, autologous, bone-marrow-derived, osteochondral progenitor cells can be isolated and grown in vitro without the loss of their capacity to differentiate into cartilage or bone. Sufficient autologous cells can be generated to initiate the repair of articular cartilage and the reformation of subchondral bone. The repair tissues appear to undergo the same developmental transitions that originally led to the formation of articular tissue in the embryo.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1994

FR901228, a novel antitumor bicyclic depsipeptide produced by Chromobacterium violaceum No. 968. I. Taxonomy, fermentation, isolation, physico-chemical and biological properties, and antitumor activity.

A novel antitumor bicyclic depsipeptide, FR901228, was isolated from a broth culture of Chromobacterium violaceum No. 968 as colorless prisms and the molecular formula was determined as C24H36N4O6S2. This antibiotic reverted the transformed morphology of a Ha-ras transformant to normal, and exhibited prominent antitumor activities against murine and human tumor cell lines both in vitro and in vivo.

3T3 Cells↗

PubMed1994

[On a circular notice about herbs in Kisodani of mid-Edo period].

There is a circular notice about the gathering of herbs in Kiso-dani of Mid-Edo Period, and this notice is stocked at T. Simada's house in Nakatsugawa City. Thirty-two herb names and the prices are recorded in this notice, and some of them have the precise description of collection, medical parts, processing, general treatment, etc. Doeki Mimura contributed greatly to the development of Kiso Yakushu (crude drug), however, we cannot pass over the activity of Saiyaku-shi (medical officer) as well.

History, 18th Century↗

PubMed1994

[Preliminary clinical results of surgery for type A acute aortic dissections using gelatin-resorcin-formaldehyde glue].

We used gelatin-resorcin-form-aldehyde (GRF) glue to fuse the false lumen of type A acute aortic dissection in four patients. All were operated on within 3-24 hours after onset, and gluing of the two cylinders of the dissecting aorta could be done safely in a short time. Initial intimal tears were located in the transverse aorta in three patients and in the proximal descending aorta in one. Simple transection and end-to-end anastomosis of the ascending aorta was done for the first two cases. But in the last two patients, we resected the intimal tear in the transverse aorta and applied GRF glue to the stump of the aortic arch and to that of the aortic root, followed by graft replacement of the ascending aorta. There were no hospital deaths. But we had to reoperate on one patient five months after the first operation due to potentially residual dissection in the aortic root. GRF glue is a very useful adhesive for acute aortic dissection operations, but further refinement of the operative technique using it is necessary.

Acute Disease↗

PubMed1994

[Detection of intratumoral DNA heterogeneity in primary lung cancer using a multiple sampling method].

The nuclear DNA contents of 18 freshly resected specimens of primary lung cancer tissue were determined by flow cytometry with a multiple sampling method. A DNA aneuploidy pattern was observed in all cases. In three cases, a diploid DNA pattern was observed along with abnormal DNA stem lines. Twelve cases (66%) had two or more abnormal DNA stem lines, and were classified as DNA multiploidy. The frequencies of DNA aneuploidy and DNA multiploidy were higher than in previously reported studies. Intratumoral DNA heterogeneity was observed in 10 cases (55%). Three of these were a mixture of DNA diploidy and DNA aneuploidy, and the other seven were a mixture of DNA aneuploidy and DNA multiploidy. If multiple sampling had not been performed in these cases, their ploidy patterns would have been misinterpreted. We conclude that multiple sampling is important in determining the precise DNA ploidy patterns of primary lung cancers.

Adenocarcinoma↗