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Biomedical subjects

M Kawano

Publications and source records attributed to M Kawano.

At least 199 records · Page 11Linked to original sources

Thyroid nodules in female uremic patients on maintenance hemodialysis.

We investigated the incidence of thyroid nodules in female uremic patients on maintenance hemodialysis using a high-frequency sonographic scanner. In 47 (21.0%) of the 224 female normal controls and 33 (55.0%) of the 60 female patients, thyroid nodules were detected. The difference in these incidences between controls and patients was significant. There were no differences in age, duration of hemodialysis, the level of blood urea nitrogen, parathyroid hormone or thyroid stimulating hormone between the patients with thyroid nodules and those without nodules. Although there is a correlation between uremia and the development of thyroid nodules, the details of the underlying mechanism of their association remain unclear.

Adult↗

Antigenic and molecular properties of Murayama virus isolated from cynomolgus monkeys: the virus is closely related to avian paramyxovirus type 2.

A new virus that belonged to a member of paramyxovirus was isolated from cynomolgus monkeys showing respiratory disorders about 20 years ago and was named Murayama virus (MrV). Interestingly, it showed no serological relationship with the mammalian paramyxoviruses tested. On the other hand, it was related to Yucaipa (YuV) and Bangor virus (BaV) belonging to avian paramyxovirus type 2 (PMV2). In analysis using anti-MrV monoclonal antibodies, MrV showed the closest relationship with YuV, and furthermore some conserved epitopes were found among avian paramyxovirus, MrV, YuV, BaV, and Newcastle disease virus (NDV). Subsequently, the nucleotide sequences of the F and HN genes of MrV were determined. In comparison with the deduced amino acid sequence of MrV and other paramyxoviruses, MrV showed the highest homology with NDV and higher similarity to HPIV2 group rather than to HPIV1 group. The present study clearly indicates that MrV belongs to PMV2 adapting to monkeys.

Amino Acid Sequence↗

Follow-up evaluation of patients with Graves' disease treated by subtotal thyroidectomy and risk factor analysis for post-operative thyroid dysfunction.

Eight-year follow-up evaluation and analysis of factors related to postoperative thyroid dysfunction were made in 216 patients with Graves' disease treated by subtotal thyroidectomy. The postoperative status of thyroid function were as follows according to hypersensitive TSH level: 65 patients (30.1%) were euthyroid, 25 (11.5%) had overt hyperthyroidism requiring treatment, 14 (6.5%) had subclinical hyperthyroidism with normal thyroid hormone and suppressed TSH, 21 (9.8%) were overt hypothyroid requiring thyroid hormone replacement and 91 (41.1%) had latent hypothyroidism without hormone replacement. In order to know factors related to postoperative thyroid function, age, sex, preoperative levels of TSH receptor antibody (TRAb), thyroid antibody titers, degree of lymphocyte infiltration, duration of medical treatment, weight of the resected thyroid tissue and weight of the remnant thyroid tissue were determined. No factor except thyroid remnant and antimicrosomal antibody titer was related to postoperative thyroid function. The weight of remnant should be less than 6 g to avoid recurrent hyperthyroidism. As recurrence of hyperthyroidism was observed more than 5 yr after surgery, long follow-up is needed.

Adolescent↗

Temporal trends of persistent organochlorine residues in human adipose tissue from Japan, 1928-1985.

Trend monitoring of organochlorine contaminants, viz. PCBs, DDTs, HCHs and CHLs, was carried out by using formalin-preserved adipose tissue of Japanese males from 1928 through 1985 for understanding the long-term trends in their contamination levels. The highest residual concentrations were observed during the periods of maximum production (or import) and usage of these compounds in Japan. Time trends of the contaminants varied with the usage pattern and their physico-chemical properties. Effectiveness of government regulations on the production and use of organochlorines was seen faster in the case of DDTs and HCHs, which showed a prominent declining trend in their residues, whereas PCB levels exhibited a continuing increase and maintained a steady state even after two decades of a ban on their production, indicating that the exposure to PCBs is still prevailing. Generally, in terms of the spatial view, unlike aquatic fauna from the point-source environment (aquatic ecosystem) humans in the non-point-source environment (terrestrial habitat) revealed a slower rate of reduction in organochlorine residue burdens.

Journal Article↗

Persistent organochlorine residues in soils from tropical and sub-tropical Asian countries.

Soil samples from paddy fields, uplands, and urban areas (gardens and roadsides) collected from Vietnam, Thailand, and Taiwan were analysed to determine the residual levels of persistent organochlorine compounds such as DDTs, HCHs, and PCBs. DDT concentration in soil samples from Vietnam were found to be highest, with a mean value of 110 ng g(-1), and were followed by those in Taiwanese soils with a mean value of 20 ng g(-1). HCH concentrations were highest in soil samples from Vietnam (a mean value of 4.8 ng g(-1)) and were followed by those from Taiwan (a mean value of 1.4 ng g(-1)). Concentrations of PCBs were found to be highest in Taiwanese soil samples, with a mean of 95 ng g(-1). Interestingly, relatively high concentrations of PCBs in rural cultivated-soil samples from Vietnam were recorded with a mean value of 25 ng g(-1), probably suggesting PCB release from different kinds of weapons used during the Second Indochina war. The lowest concentrations of DDTs, HCHs, and PCBs were obtained in soil samples from Thailand, with mean values of 8.3 ng g(-1), 0.4 ng g(-1), and 2.7 ng g(-1), respectively.

Journal Article↗

Sequence determination of the P gene of simian virus 41: presence of irregular deletions near the RNA-editing sites of paramyxoviruses.

The complete nucleotide sequence of the P gene of simian virus 41 (SV41) was determined. The gene was found to be 1406 nucleotides long and to contain a relatively small open reading frame encoding a cysteine-rich V protein with a calculated M(r) of 24076. We have demonstrated that RNA-editing events occur in SV41 P gene transcripts and that the ratio of edited mRNAs to faithfully copied mRNA (P-mRNA:V-mRNA) is about 1:5 at either 24 or 40 h post-infection. The mRNA with two G insertions was capable of encoding a P protein of 395 amino acids with a predicted M(r) of 41,992. A kinetic study of P and V proteins by Western blot analysis showed that in virus-infected cells the amounts of both proteins were almost equal although the V-mRNA was considerably more abundant than the P-mRNA. Alignment of the SV41 P and V proteins with those of nine other paramyxoviruses demonstrated that irregular gaps were present around the RNA-editing sites.

Amino Acid Sequence↗

Diabetes mellitus induces accelerated growth of aortic smooth muscle cells: association with overexpression of PDGF beta-receptors.

The mechanism of diabetic macroangiopathy was studied from the view point of phenotypic change of aortic smooth muscle cells (SMC). The growth rates of cultured SMC of diabetic rats or rabbits were higher than those of non-diabetic animals (controls). This difference of the growth responses was observed specifically with platelet-derived growth factor (PDGF). Of the three PDGF dimers, PDGF-AB heterodimer (PDGF-AB) and PDGF-BB homodimer (PDGF-BB) stimulated growth of diabetic SMC more than that of control SMC but PDGF-AA homodimer (PDGF-AA) did not. The binding of 125I-PDGF to the diabetic SMC was greater than that to control SMC. This was due to increase in the number of cell surface receptors for PDGF. On in vitro culture, SMC from diabetic rats expressed more PDGF beta-receptor mRNA than SMC from non-diabetic rats. Moreover, in vivo, the aortic media of diabetic rabbits expressed PDGF beta-receptor mRNA, but that from non-diabetic rabbits did not. Thus diabetic SMC over-react on PDGF stimulation through over-expression of the PDGF beta-receptor gene. The significance of this fact in development of diabetic macroangiopathy is discussed.

Animals↗

Decreased expression of the platelet-derived growth factor beta-receptor in fibroblasts from a patient with Werner's syndrome.

The study of Werner's syndrome, a premature ageing syndrome, may provide insight into the processes of natural ageing. We investigated the reason for the reduced growth potential of fibroblasts in Werner's syndrome which is considered to be similar to that of fibroblasts in normal senescence. The responses to different isoforms of platelet-derived growth factor (PDGF) of fibroblasts from a patient with Werner's syndrome (W-cells) and from a normal subject (control cells) were assessed by [3H]thymidine incorporation assay, a 125I-PDGF-AB binding experiment, and Northern blot analysis with a PDGF beta-receptor specific cDNA probe. PDGF-stimulated increase in [3H]thymidine incorporation in W-cells was much lower than that in control cells, especially with PDGF-AB and -BB as mitogens. The specific binding of 125I-PDGF-AB to W-cells was correspondingly lower than that to control cells. Furthermore, Northern blot analysis demonstrated a decreased basal level, and lack of PDGF-AB-induced up-regulation of the PDGF beta-receptor transcript in W-cells. Decreased expression of the PDGF beta-receptor due to decrease in its synthesis may be a causative factor of the decreased mitogenic response of W-cells to PDGF.

Cell Division↗

[Multichannel cochlear implantation in a deaf child].

A multichannel cochlear implantation was performed in an 8-year-old child and the following results were obtained. The surgical procedures were not particularly difficult as compared to cochlear implantation for adults. Postoperative rehabilitation requires a longer time than in adult patients. Cochlear implants are useful not only for the recognition of environmental sound but also for the recognition of speech. Cooperation with the medical facility, as well teachers and family members, is essential.

Child↗

Incidence of ultrasonographically-detected thyroid nodules in healthy adults.

We studied the incidence of thyroid nodules in healthy adults, who had no history of thyroid disease, in Tokushima, Japan, where goiter is not considered endemic. Examination was performed by palpation and using a 10-MHz real-time sonographic scanner. Palpable thyroid nodules were present in two (0.9%) of 227 men and in four (1.8%) of 224 women. On the other hand, nodules were detected by ultrasonography in 42 men (18.5%) and 47 women (21.0%). There was no significant difference in the incidence detected by ultrasonography between men and women in any of the age groups, except in men above 60 years old. It is concluded that thyroid nodules are not an uncommon disorder even in men. Since, clinically, the incidence of nodularity appears to be higher in women than in men, there may be difference between men and women in the development of nodules until they become clinically detectable.

Adult↗

Neuroanatomical analysis of peptidergic input in the spinal nucleus of bulbocavernosus.

The spinal nucleus of bulbocavernosus (SNB) is located in the anterior horn of the lower lumbar and upper sacral segments of the spinal cord and plays a significant role in the regulation of external sphincters and other muscles of the urogenital tract and rectum. The present study examined characteristic features of peptidergic input to this nucleus in rat using a double immunostaining method at both light and electron microscopic levels, focused on an analysis of relationship between cholinergic motoneurons and neuropeptide Y (NPY) axon terminals in the SNB. At the light microscopic level, NPY immunoreactive terminals were frequently distributed in the SNB and some were in the vicinity of the cholinergic cells. At the electron microscopic level, some of NPY immunoreactive terminals were seen to form synaptic contacts with cholinergic neurons on their somata and dendrites in the SNB. These findings suggest that NPY terminals are involved in the functioning of cholinergic SNB motoneurons via the synapse.

Animals↗

Surgical and medical management of patients with pulmonary metastasis from parathyroid carcinoma.

BACKGROUND: The aim of this study was to characterize patients with pulmonary metastasis of parathyroid carcinoma and to evaluate the long-term effect of surgical and medical therapy. METHODS: Seven patients with pulmonary metastasis of parathyroid carcinoma were treated between 1980 and 1992. Six patients underwent resection of pulmonary metastases, and one patient has had long-term bisphosphonate therapy alone. Bisphosphonate was also given before or after operation to three patients. RESULTS: Two patients underwent a unilateral thoracotomy for a single pulmonary lesion, and four other patients with multiple lesions underwent staged bilateral thoracotomies. The postoperative serum calcium level returned to normal after each thoracotomy in three patients who were alive and well 3, 8, and 12 years after the first thoracotomy. Hypercalcemia persisted in the other three patients. In two of the patients, bisphosphonate therapy was also unable to control hypercalcemia. In one patient the serum calcium level has been maintained in the 13 mg/dl range by bimonthly bisphosphonate therapy alone for 3 years. CONCLUSIONS: The aggressive surgical approach to pulmonary metastasis of parathyroid carcinoma was shown to be effective for palliation in selected patients. Bisphosphonate therapy is an alternative to resection but has only a temporary calcium-lowering effect.

Adolescent↗

[Posterolateral rotatory instability of the elbow--a case report and anatomical study of the lateral collateral ligament].

A 20-year-old woman was referred to our clinic complaining of recurrent subluxation of her right elbow. A posterolateral rotatory instability test revealed that she had insufficiency of the lateral collateral ligament. She was surgically treated; the ligament was reconstructed by using the palmaris longus tendon. A year after operation, she had no pain in her elbow, and regained full range of elbow motion. The function of the lateral collateral ligament is often overlooked. We, therefore, dissected 24 elbow joints and studied anatomically in order to confirm the origin and insertion of the lateral collateral ligament. The ligament originates from the lateral epicondyle, and runs distally in fan shape. It further inserts partly to the annular ligament and partly to the supinator crest. After complete sectioning of the ligament, the forearm was fixed in supination, then flexed with valgus moment. This maneuver elicited subluxation of the radio-humeral joint, which was similar to what we observed in the clinical case. From these observations, we have concluded that the ligament is important for stability of elbow joint as well as the medial collateral ligament.

Adult↗

Regulation of the concentration of pre beta high-density lipoprotein in normal plasma by cell membranes and lecithin-cholesterol acyltransferase activity.

A minor fraction of plasma high-density lipoprotein (pre beta-1 HDL) has been shown to promote cholesterol efflux from peripheral cell membranes [Castro, G. R., & Fielding, C. J. (1988) Biochemistry 27, 25-29]. When isolated native plasma is incubated at 37 degrees C, this fraction is specifically decreased. On the other hand, the level of plasma pre beta-1 HDL is fully protected in the presence of even very low levels of fibroblasts, vascular smooth muscle cells, or macrophages. Blood cells were completely inactive in maintaining plasma pre beta-1 HDL levels in the absence of peripheral cells, even at the relatively high levels present in whole blood. The loss of pre beta-1 observed in isolated plasma was dependent upon lecithin-cholesterol acyltransferase (LCAT) activity. These data suggest that reverse cholesterol transport catalyzed by pre beta-1 HDL, and subsequent LCAT-mediated cholesterol esterification, is directly dependent upon the interaction between this HDL species and competent peripheral cells.

Cell Membrane↗