Kinetics of nucleation in a dilute polymer solution.
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Journal Article↗
Biomedical subjects
M Nakata
Publications and source records attributed to M Nakata.
Immunohistochemical study of nerve fibres with substance P- or calcitonin gene-related peptide-like immunoreactivity in the junctional epithelium of developing rats.
The beginning of innervation in the junctional epithelium of maxillary first molars was examined in gingival tissues from 19 to 32-day-old rats. Substance P- or calcitonin gene-related peptide (CGRP)-like immunoreactivity was demonstrated by the avidin-biotin peroxidase complex method. In 19-day-old rats, nerve fibres with substance P- or CGRP-like immunoreactivity were seen in the connective tissue and oral epithelium, but not in the reduced enamel epithelium, which would be transformed into the junctional epithelium. In 21-day-old rats, the fibres with substance P- or CGRP-like immunoreactivity formed a plexus in the oral sulcular epithelium and thin varicose fibres were seen for the first time entering the adjacent reduced enamel epithelium. These fibres also penetrated the middle portion of the reduced enamel epithelium, but did not reach the cuboidal reduced ameloblasts. More nerve fibres had CGRP-like immunoreactivity than substance P-like immunoreactivity. In 23-day-old rats, many fibres with both immunoreactivities were seen in the basal layers of the junctional epithelium, but only a few were seen in its superficial layers. In 28-32-day-old rats, numerous fibres with both immunoreactivities were distributed in the whole junctional epithelium and showed a similar pattern of innervation. For all immunoreactive fibres, the density in the middle portion in the junctional epithelium was the highest. The nerve plexus was formed in the basal layers and some fibres with a varicose appearance were found in the superficial layers.
Animals↗
The action of GABAB antagonists in the trigeminal nucleus of the rat.
The iontophoretic administration of the GABAB antagonists (P-(3-aminopropyl)-P-diethoxymethyl-phosphinic acid (CGP 35348) and 2-hydroxy-saclofen blocked the action of iontophoretically applied L-baclofen on neurons in the trigeminal nucleus of rats, anesthetized with halothane. The substance CGP 35348 appeared to be more potent than 2-hydroxy-saclofen. The iontophoretic administration of GABA resembled L-baclofen in depressing excitatory transmission and facilitating segmental inhibition in the trigeminal nucleus. The depression of excitatory transmission was also blocked by CGP 35348 and the facilitation of segmental inhibition produced by GABA was partially blocked. These observations indicate that CGP 35348 is not only a baclofen antagonist but actually a GABAB receptor antagonist and the baclofen was acting at GABAB receptors in the trigeminal nucleus. The portion of the effect of GABA, not blocked by CGP 35348, was probably mediated by GABAA receptors, since it was previously found that segmental inhibition in the trigeminal nucleus could be modulated by GABAA agonists and antagonists as well.
Animals↗
Protein binding and DNase-I-hypersensitive sites in the cis-acting regulatory region of the spore-coat SP96 gene of Dictyostelium.
The spore-coat protein gene (SP96) of Dictyostelium discoideum is transcribed only in prespore cells. To identify the cis-acting region of this gene, mutant mini-genes which contained different lengths of 5' upstream region, the partially deleted SP96 coding region and ca. 600 bp of 3' flanking sequence were transformed into D. discoideum cells. Expression of the mini-genes was analysed by Northern hybridization. Our results indicate that the 5' upstream region from -686 to -494 contains an important cis-acting element for the temporal and cell type-specific transcription. A nuclear factor which specifically bound the cis-acting region was identified by gel retardation assay. DNase-I-hypersensitivity of the 5' upstream region was examined and it was shown that the appearance of two new hypersensitive sites correlates with transcriptional activation of the gene. One of the two sites maps to the TATA region and the other was located in the cis-acting region identified by deletion analysis. Our results suggest that gene activation occurs by conformational changes in the chromatin structure of the cis-acting region followed by subsequent binding of regulatory factors and the TATA-binding protein.
Animals↗
Role of perforin in lymphocyte-mediated cytolysis.
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Amino Acid Sequence↗
Histologic investigation of the human pulp after thermodebonding of metal and ceramic brackets.
Twenty-five human permanent teeth scheduled for extraction for orthodontic reasons were used to study the effect of thermodebonding on the pulp tissue. One week before brackets were removed the teeth were bonded with either metal or ceramic brackets, with two alternative adhesives. For debonding, three different techniques were used: (1) debonding of ceramic brackets warmed up indirectly by resistance heating of a metallic bow applied to the bracket slot, (2) debonding of metal brackets warmed up directly by inductive heating of the bracket itself, and (3) debonding of ceramic brackets warmed up indirectly by inductive heating of metallic plier tips, applied to the mesial and distal bracket surfaces. Teeth with metal brackets removed without heat by squeezing the wings together served as a control group. The teeth were extracted 24 hours after debonding and subjected to a light microscopic study after histologic preparation and staining. In addition, the location of adhesive remnants was evaluated. While the thermodebonding of metal brackets worked properly and without any obvious pulp damage, there were problems related to the thermodebonding of ceramic brackets: (1) if more than one heating cycle was necessary, several teeth showed localized damage of the pulp with slight infiltration of inflammatory cells, (2) bracket fractures occurred frequently, and enamel damage could be shown, and (3) often with Transbond (Unitek/3M, Monrovia, Calif.) as the adhesive, more than one heating cycle was necessary for bracket removal, and thus patients complained about pain.
Adolescent↗
Demonstration of type III collagen in the dentin of mice.
It has been reported that, although type III collagen is present in human dentin where there is dentinogenesis imperfecta and in reparative dentin, it is absent in normal dentin. In a preliminary study, however, we observed evidence showing that small amounts of fibers showing positive labeling for type III collagen are present in the molars of normal mice. In the present study, in order to localize type III in normal dentin, immunofluorescent and immunoelectron microscopic examinations of the molars of normal mice were carried out using affinity-purified antibodies to mouse type III and type I collagen. The fibers positive for type III collagen were much more frequently observed in the root than in the crown. These fibers ran in peritubular dentin or near that in parallel to them. The incidence of the existence of dentinal tubules associated with type III collagen-positive fibrils either in or near peritubular dentin was low. These fibrils positive for type III collagen showed a clear cross-banding. In dentinal tubules, unusual collagen aggregations, segment long-spacing-like and fibrous long-spacing-like structures which were intensively stained for type I collagen but weakly so for type III collagen were seldom observed. Type III collagen-positive fibers often extended towards the pulp beyond the odontoblast layer, suggesting that these fibers were produced, at least partly, by the pulp cells.
Animals↗
Expression of perforin and cytolytic potential of human peripheral blood lymphocyte subpopulations.
To verify the physiological role of the pore-forming protein perforin in vivo, its expression in subpopulations of human peripheral blood lymphocytes was examined by immunocytochemical staining and their cytolytic potentials compared. In addition to NK cells and gamma delta T cells, which uniformly expressed abundant perforin in their cytoplasmic granules, only a small subpopulation of CD8+ alpha beta T cells contained perforin, namely the CD11b+ subset. However, in vitro activation with an anti-CD3 antibody and IL-2 induced perforin expression in approximately 50% of the CD8+CD11b- T cells and also in a small subset of CD4+ T cells. A distribution of perforin in CD8+ and CD4+ T cells, similar to in vitro activated T cells, was observed in fresh peripheral blood lymphocytes from infectious mononucleosis patients. In all instances, the expression of perforin correlated with the cytolytic potential of these subpopulations. The results strongly suggest that perforin plays a role in the manifestation of cytotoxic activity in vivo.
Antigens, CD↗
The effects of radical scavengers and leukocyte-depleted blood on reperfusion injury of extirpated rabbit lung.
Oxygen radicals produced by polymorphonuclear leukocytes were considered primarily responsible for reperfusion injury in lung transplantation. Using the extirpated rabbit lungs as a transplant model, we measured lung water volume, the oxygen radicals of lung tissue using a direct method (electron spin resonance) and an indirect method (measurement of peroxide lipids). The effects of free radical scavengers, human superoxide dismutase (h-SOD) and catalase (CAT), and leukocyte-depleted blood on reperfusion injury were evaluated in three experimental groups. Group I (n = 8, control): Lung reperfusion was performed with blood from other rabbits. Group II (n = 7): Immediately before reperfusion, h-SOD (1,500 u/ml) and CAT (3,000 u/ml) were added to the blood. Group III (n = 7): Reperfusion was performed with the leukocyte-depleted blood. Severe pulmonary edema and an elevation of malondialdehyde (MDA) occurred in Group I. In Group II, addition of radical scavengers to the reperfusion blood produced only mild pulmonary edema, but an elevation of MDA occurred as in Group I. In Group III, pulmonary edema and MDA elevation were almost completely suppressed.
Animals↗
Analysis of retained ventricular shunt catheters.
To identify the causes of ventricular shunt catheter retention, 42 shunt removals in 28 patients in our neurosurgical clinic from 1982 to 1991 were analyzed. The mean patient age was 13.8 years (2 mos-78 yrs), and mean shunt duration was 20.1 months (0.5-94 mos). There were nine retained ventricular catheters, including five with obstruction of the ventricular catheter. Shunt duration was significantly longer compared with the unretained group. Three retained ventricular catheters were stained by HE for histological examination. Light microscopy showed the inner lumen of catheters filled with granulomatous connective tissue and reactive glial tissue, and giant cell reaction to silicone material. Scanning electron microscopy of two catheters found peeling on the inner surface of the catheter, evidence of aging of the material. Granulomatous connective tissue and glial tissue reaction to aged silicone are suggested as the cause of catheter retention.
Adolescent↗
A new anthracycline antibiotic, cinerubin R. Taxonomy, structural elucidation and biological activity.
A novel anthracycline antibiotic, cinerubin R, was isolated from the fermentation broth of Streptomyces eurythermus strain H1715MY2. The structure of cinerubin R was elucidated to be 4"-aculosyl-4'-rhodinosyl-7-rhodosaminyl-epsilon-py rromycinone. Cinerubin R was active against Gram-positive bacteria and inhibited the growth of divergent multi-drug-resistant cells to the same extent as their parental cells.
Animals↗
[Electrophysiological evaluation of human consciousness level by "Automated Fluctuation Analysis" of human high frequency EEG].
This study is done to clarify the clinical meaning of "Automated Fluctuation Analysis" of high frequency EEG in man especially focused on the fine alteration of consciousness level of the subjects. Twenty normal volunteers were utilized for this study. They were divided into two groups, the subjects who felt sleepiness (Group S; N = 8) and the subjects who denied it (Group W; N = 12), during the EEG recording. "Automated Fluctuation Analysis" of high frequency EEG had been presented in our previous paper. In short, it is made of three steps, amplification of EEG signal, A/D conversion and Fast Fourier Transform by signal processor and extraction of Lorentzian parameters. Power spectral density (PSD) was displayed on log-log graph. Then the third step is performed by the best curve fitting program to the following equation, S (f) = S1/[1 + (f/fc1)2] + S2/ [1 + (f/fc2)2], where S(f) is power spectral density at any frequency f, S1 and S2 are plateau level of initial and second Lorentz, respectively and fc1 and fc2 are the corner or half power frequency of initial and second Lorentz, respectively. The algorithm of this program to extract these parameters were mathematically based on Brown & Dennis. As results, 1. PSD of human high frequency EEG was composed of double Lorentzians and vanished into white level within 1kHz. 2. A topographical display of S1 value revealed hyperfrontal in group W, which is in accordance with the cerebral blood flow study by Ingvar.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
[Clinical study of synchronous multiple primary cancer involving the lung].
Ten cases of synchronous multiple primary cancer involving the lung were experienced in our hospital during the period from January 1962 to May 1987. The incidence rate was 1.3% of all hospitalized cases of primary lung cancer. The counterpart organs were thyroid gland (4 cases), stomach (2 cases), colorectum (2 cases) and lung (2 cases). Three of four thyroid cancer cases were resected at the same time of pulmonary resection, whereas the stomach and colorectal cancer cases underwent two stage operation. Lung perfusion scintigraphy was very useful in determining the operative method for synchronous multiple primary lung cancer. The 5-year survival rate of all cases of synchronous multiple primary cancer involving the lung was 26.3%, with no hospital death. Surgical treatment is recommended for such cases when both cancers are expected to be resected completely.
Adult↗
[Sudden death due to bilateral pulmonary thromboembolism in a patient with multiple myeloma: an autopsy case report].
We encountered a patient with multiple myeloma who died suddenly, in whom bilateral pulmonary artery thrombosis was found at autopsy. The patient was a 50-year-old woman who had received chemotherapy for multiple myeloma at a local clinic for 4 years, and was transferred to our hospital because of recurrence of multiple myeloma in August 1990. Despite chemotherapy performed after admission, serum globulin level increased and her low back pain worsened, and she was generally restricted to bed. On October 21, she developed sudden dyspnea, became markedly cyanotic, lost consciousness, and then suffered a cardiopulmonary arrest. Autopsy revealed bilateral pulmonary artery thrombosis as well as thrombosis in the pelvic veins. Hyperviscosity due to multiple myeloma and long-term recumbency were the probable causes of pelvic venous thrombosis and subsequent pulmonary artery thrombosis. We report a rare case of bilateral pulmonary artery thrombosis which developed during the course of multiple myeloma and led to sudden death.
Death, Sudden↗
The surgical treatment of invasive thymoma. Resection with vascular reconstruction.
We have treated 96 patients with thymoma during the past 27 years; 57 of them had invasive thymoma. Surgical resection was undertaken in 45 of the 57 patients with invasive thymoma, including 14 patients in whom tumors were extirpated with vascular reconstruction. In addition, six patients with other thymic malignancies were treated in the same way. In six patients only angioplasty was performed, whereas artificial grafts were used in the other 14 patients. Ten of the 20 patients are still alive and well. One has probably been cured, since no signs of recurrence have been noted during the postoperative follow-up period of 8 years. No complications or occlusive symptoms were observed in these patients postoperatively, except in one who died after gastrointestinal hemorrhage. In one patient long-term patency of the vascular graft was confirmed by angiography and magnetic resonance imaging 5 years after operation. This intensive surgical procedure improved the quality of life for patients with the superior vena caval syndrome and may also have improved the prognosis of the patients with invasive thymoma.
Adult↗
[Electrophysiological evaluation of diazepam anesthetic effect by "automated fluctuation analysis" of high frequency EEG in human].
"Automated fluctuation analysis" of human scalp EEG was made in order to evaluate anaesthetic effect of intravenous diazepam injection. Seven patients without disturbed consciousness were utilized for this study. Analytical system is composed of high fidelity pre-amplifier and signal processor. After 10,000 amplification of the signal, A/D conversion and Fast Fourier Transform were programmed with following parameters, sweep time; 12 sec., frequency resolvability; 1.2 Hz, frequency limit; 1 kHz, Fourier points; 2048 and Fourier time; 15. Power spectral density (PSD) was displayed on log-log graph. The best curve fitting program was next applied to the following equation, S(f) = S1/[1 + (f/fcl)2]+S2/[1 + (f/fc2)2] S(f): power spectral density, S1,S2: plateau levels of the initial and the second Lorentz, fcl, fc2: the corner or half power frequencies of the initial and the second Lorentz). As results, 1) PSDs of high frequency EEG up to 1 kHz were composed of double Lorentzian fluctuations. 2) From our previous animal study, it is suggested that the initial and the second Lorentz reflect the cortical and subcortical functions, respectively. 3) After diazepam injection, the second Lorentz was suppressed according to the time and dose and disappeared when the subjects fell asleep, and reappeared when waked up. There was excellent correlation between the consciousness level and the second Lorentz. 4) The initial Lorentz reflected higher cortical function; the ability of calculation or language were reduced after diazepam injection, and the hyperfrontal activity of the initial Lorentz disappeared. These results may suggest that "Automated Fluctuation Analysis" of high frequency EEG may have a potential to develop a new field in clinical neuroelectrophysiology.
Adult↗
[Pulmonary thromboembolism associated with myelodysplastic syndrome].
We present a 65-year-old female with myelodysplastic syndrome (MDS) who has attended our O.P.D. since 1983. In early December, 1990, dyspnea on effort developed which then progressed to dyspnea at rest at the end of December. She was admitted on January 8 with orthopnea. Chest X-ray films revealed loss of vascular shadows of the right lung. Blood gas analysis showed hypoxemia and hypocapnemia. Abnormalities in the coagulation-fibrinolytic system (increased TAT (thrombin-anti-thrombin III complex) and alpha 2-PIC (plasmin inhibitor complex)), possibly due to MDS, were detected. The diagnosis of pulmonary thromboembolism was made by pulmonary perfusion scintigram and pulmonary arteriography. After commencement of anticoagulation therapy on January 15, the subjective symptoms, blood gas analysis, pulmonary scintigram, and disorders of the coagulation-fibrinolytic system improved. The patient was discharged on March 5, 1991. The present case of myelodysplastic syndrome was associated with abnormalities of the coagulation-fibrinolytic system and was complicated by pulmonary thromboembolism.
Aged↗
Interleukin-2 activated T cells (T-LAK) express CD16 antigen and are triggered to target cell lysis by bispecific antibody.
Human PBMCs from healthy donors were cultured with 100 U/ml rIL-2 for up to 5 weeks and tested at short and long activation times for the ability to mediate CD3 and CD16 targeted cytotoxicity using chemically cross-linked bispecific antibodies. At each period, LAK activity was augmented with the use of bispecific antibodies (BA), whereas interestingly enough, at later periods (4-5 weeks) when CD16 positive lymphocytes are not present by flow cytometry, CD16 targeted cytotoxicity was induced. We suspected the possibility of CD16 expression on activated T cells and have purified the T cell subpopulations to see the targeted cytotoxicity. Populations enriched for T cells by Percoll density centrifugation, treatment with anti-CD16 plus complement or sorting for CD5+ cells, were all able to mediate CD16 targeted cytotoxicity following activation with rIL-2. These data suggest that IL-2 activated T cells express CD16 in addition to CD3.
Antibody Specificity↗