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Biomedical subjects

R Takeuchi

Publications and source records attributed to R Takeuchi.

At least 73 records · Page 4Linked to original sources
PubMed1992

Genomic structure of the human caldesmon gene.

The high molecular weight caldesmon (h-CaD) is predominantly expressed in smooth muscles, whereas the low molecular weight caldesmon (l-CaD) is widely distributed in nonmuscle tissues and cells. The changes in CaD isoform expression are closely correlated with the phenotypic modulation of smooth muscle cells. During a search for isoform diversity of human CaDs, l-CaD cDNAs were cloned from HeLa S3 cells. HeLa l-CaD I is composed of 558 amino acids, whereas 26 amino acids (residues 202-227 for HeLa l-CaD I) are deleted in HeLa l-CaD II. The short amino-terminal sequence of HeLa l-CaDs is different from that of fibroblast (WI-38) l-CaD II and human aorta h-CaD. We have also identified WI-38 l-CaD I, which contains a 26-amino acid insertion relative to WI-38 l-CaD II. To reveal the molecular events of the expressional regulation of the CaD isoforms, the genomic structure of the human CaD gene was determined. The human CaD gene is composed of 14 exons and was mapped to a single locus, 7q33-q34. The 26-amino acid insertion is encoded in exon 4 and is specifically spliced in the mRNAs for both h-CaD and l-CaDs I. Exon 3 is the exon that encodes the central repeating domain specific to h-CaD (residues 208-436) together with the common domain in all CaD (residues 73-207 for h-CaD and WI-38 l-CaDs, and residues 68-201 for HeLa l-CaDs). The regulation of h- and l-CaD expression is thought to depend on selection of the two 5' splice sites within exon 3. Thus, the change in expression between l-CaD and h-CaD might be caused by this splicing pathway.

Alternative Splicing↗
PubMed1992

Developmental changes in nerve growth factor level in rat serum.

In serum, nerve growth factor (NGF) forms a complex with alpha 2-macroglobulin (alpha 2M), which formation inhibits the immunoreactivity between NGF and its antibodies. For measuring the serum level of NGF, it is thus necessary to liberate NGF from the NGF-alpha 2M complex and prevent reformation of such complex. The pretreatment of rat serum with 1 M guanidine hydrochloride for a few hours and operation of the enzyme immunoassay (EIA) in the presence of guanidine hydrochloride provided a reliable means for determination of the NGF level in serum. By this procedure we followed the serum NGF level in rats developmentally. It increased from prenatal day 2 to postnatal day 5 and decreased slightly at postnatal week 3, thereafter remaining constant throughout adulthood. In pregnant rats, the NGF level in serum increased threefold to fivefold before birth and then decreased rapidly. These data suggest that serum NGF level may reflect the demand for this molecule during establishment of the peripheral nervous system.

Aging↗
PubMed1992

Transient thyrotoxicosis in a patient with a functioning nodule; a possible occurrence of silent thyroiditis.

A 48-year-old woman with diffuse goiter presented with typical symptoms and signs of thyrotoxicosis. Thyroid scanning with I-123 revealed a localized accumulation of the radionuclide in the left lobe which corresponded to a small nodule later detected by ultrasonography, with suppression of the remaining tissues. Owing to the overall reduced radioactivity in the thyroid, she was suspected of having silent thyroiditis causing thyrotoxicosis. Meanwhile, the thyrotoxicosis subsided concurrently with an increase in radioactivity in the extranodular area that had initially been suppressed. The histology of thyroid tissues obtained at the time of operation revealed follicular adenoma or hyperplasia in the area of the localized I-123 uptake and findings similar to those in Hashimoto's thyroiditis in the remaining tissues, supporting our clinical diagnosis of silent thyroiditis together with a functioning nodule.

Female↗
PubMed1992

CT-based geometric data of human spine musculature. Part I. Japanese patients with chronic low back pain.

Mechanical factors are considered to play a dominant role in low back problems. Various spinal structures, including muscles, act in unison to resist the external load, including the body segments. An estimation of the forces in these requires a knowledge of the orientation, location, and area of cross-section of the muscles to complete the information for the formulation of a truly three-dimensional biomechanical mathematical model of the spine in the lumbar region. Computed tomography scans of 10 Japanese patients suffering from chronic low back pain were obtained to determine the geometric data of the abdominal and back muscles from the 12th thoracic vertebral to the first sacral vertebral level. The mean age +/- 1 SD of the group was 40.1 +/- 14.12 years (range, 24-70), 573 +/- 88.5 N of body weight (range, 441-705), and 1.63 +/- 0.09 m tall (range, 1.44-1.74). The geometric parameters quantified were the line of action, and the centroid and physiologic area of cross-section of each muscle as a function of the spinal level. The effective/physiological area of cross-section of each muscle changed along the length of the spine because of the change in the line of action of the muscle. The centroidal approach adopted for quantifying the lines of action of various muscles was found unsuitable for the abdominal muscles, excluding the rectus abdominis, because of the associated anatomic complexities. Alternatives are proposed to complete the data base. The application of the data for the formulation of a truly three-dimensional biomechanical model of the spine at the L3-4 level is briefly presented. Application to nonlinear optimization-based force predictions in various spinal structures is discussed.

Adult↗
PubMed1992

Ga-67 citrate accumulation in adenomatous goiter.

An elderly woman with a diffusely enlarged goiter and multiple miliary nodular lesions on chest x-ray showed Ga-67 accumulation in the right thyroid lobe. Histologic findings obtained after total thyroidectomy and open lung biopsy revealed papillary carcinoma in the left lobe with pulmonary metastases and adenomatous nodules in the right lobe. This is the first report of Ga-67 accumulation in adenomatous goiter.

Adenoma↗
PubMed1992

Human parathyroid hormone-related peptide-(107-111) does not inhibit bone resorption in neonatal mouse calvariae.

Recent analysis of the structure-function relationship of human PTH-related peptide (hPTHrP) has led to the discovery that its direct inhibitory activity on osteoclastic bone resorption resides fully in the 107-111 sequence of the peptide, as assessed by a bone resorption assay using isolated rat osteoclasts. Here we report that hPTHrP-(107-111) is inactive in neonatal mouse calvariae in culture. hPTHrP-(107-111), at doses of 10(-12)-10(-6) M and incubation periods up to 96 h, did not affect either basal or agonist-stimulated 45Ca release from prelabeled neonatal mouse calvariae, while salmon calcitonin was a potent and powerful inhibitor of both basal and stimulated 45Ca release from bone. Moreover, salmon calcitonin, but not hPTHrP-(107-111), inhibited the increase in osteoclast number in hPTHrP-(1-34)-treated bones. Furthermore, hPTHrP-(107-139) also failed to inhibit 45Ca release and the hPTHrP-(1-34)-induced increase in osteoclast number in this organ culture model when tested under conditions identical to those for hPTHrP-(107-111). The addition of indomethacin to hPTHrP-(107-111)- or hPTHrP-(107-139)-treated bones was without effect, excluding the possibility that the direct inhibitory activity of these peptides on osteoclasts is ablated by a prostaglandin-mediated mechanism. Although the mechanism underlying the apparent inability of the carboxyl-terminal PTHrP fragments to inhibit osteoclastic bone resorption in neonatal mouse calvariae is unknown, it may involve the complex microenvironment of osteoclasts in intact bone, which contains a large variety of cell types other than osteoclasts.

Animals↗
PubMed1991

Memory impairment and morphological changes in rats induced by active fragment of anti-nerve growth factor-antibody.

Treatment of rats with a specific Fab' fragment of anti-nerve growth factor (NGF)-antibody (anti-NGF, 12, 120 and 400 micrograms/4 weeks, i.c.v.) impaired their learning ability. The distance of swimming of anti-NGF-treated rats in a water maze was shortened more slowly by training than that of control rats. Anti-NGF treatment altered the staining of nuclei of cells in the hippocampus, parietal cortex and dentate gyrus with hematoxylin. It is suggested that the anti-NGF-induced amnesia could be due to change in nuclear morphology.

Animals↗
PubMed1991

Memory impairment and morphological changes in rats after continuous infusion of active fragment of anti-nerve growth factor-antibody.

We report here that the specific Fab' fragment of anti-nerve growth factor (NGF)-antibody (anti-NGF, 12, 120 and 400 micrograms/4 weeks, i.c.v.) impairs learning and memory. The goal latency of the control rats in water maze task was rapidly shortened by training compared to those of the anti-NGF-treated rats. The degree of reduction in movement counts of the anti-NGF-treated rats in habituation task was significantly smaller than that of the control rats. However, the step-through latency of the anti-NGF-treated rats was not significantly shorter than that of the control rats. With regard to the choline acetyltransferase activity, no effects were observed in any of the brain regions. Anti-NGF treatment altered nuclear morphology in the hippocampus and parietal cortex. As a result, it seems that the anti-NGF-induced amnesia could be due to an impairment of nuclear morphology.

Analysis of Variance↗
PubMed1990

Stimulation of nerve growth factor synthesis/secretion by 1,4-benzoquinone and its derivatives in cultured mouse astroglial cells.

Previously we reported that astroglial cells cultured from mouse brain synthesize and secrete nerve growth factor (NGF) and that, in quiescent cells, catecholamines markedly increase the NGF content in the conditioned medium (CM). We wished to further assess the structural properties required for exhibition of such effect of compounds containing a ring structure analogous to that of catechol on astroglial NGF synthesis. During our study, we found that hydroquinone, which was confirmed not to stimulate NGF synthesis in mouse fibroblast cells in another of our investigations, is a potent stimulator of NGF synthesis in astroglial cells and that 1,4-benzoquinone, an oxidized form of hydroquinone, is a more effective stimulator than hydroquinone itself. In addition, the results of experiments with 1,2-benzoquinone derivatives indicated that the presence of a long aliphatic side chain in the molecule eliminates the stimulatory effect of 1,4-benzoquinone on NGF synthesis in astroglial cells.

Animals↗
PubMed1990

A nosocomial outbreak of epidemic keratoconjunctivitis due to adenovirus type 37.

An outbreak of epidemic keratoconjunctivitis occurred at the department of ophthalmology of a hospital in Yokohama, involving 14 inpatients, 12 outpatients, and 2 doctors. Adenovirus type 37 (Ad-37) was isolated from the conjunctival swab in 12 of 18 cases. In neutralization tests, the isolates showed some cross-reaction with adenovirus type 19 (Ad-19). The Ad-37 isolates were indistinguishable from each other and from the prototype Ad-37, but distinct from the prototype Ad-19 in the restriction endonuclease analysis of viral DNA.

Adenovirus Infections, Human↗
PubMed1990

Cauda equina neurinoma associated with normal pressure hydrocephalus--case report.

A 45-year-old male was hospitalized because of gait disturbance, urinary incontinence, and memory disturbance. A computed tomographic (CT) scan revealed dilatation of the cerebral ventricles, and a metrizamide CT scan showed reflux into all ventricles. Cerebrospinal fluid obtained at the time of metrizamide CT was highly xanthochromic. Myelograms demonstrated a tumor between the inferior portion of the fifth lumbar vertebra and that of the second sacral vertebra. After removal of a spinal tumor involving nerve fibers at the cauda equina, his symptoms disappeared and the spinal fluid protein normalized. Three months after surgery, a CT scan revealed reduction of cerebral ventricular size. There are 10 reported cases of spinal tumors resulting in normal pressure hydrocephalus. All these and present cases involved protein in the spinal fluid, which might have been the cause of the hydrocephalus.

Cauda Equina↗
PubMed1990

Highly sensitive enzyme immunoassay for beta-nerve growth factor (NGF): a tool for measurement of NGF level in rat serum.

A sensitive two-site enzyme immunoassay (EIA) system was established for mouse beta nerve growth factor (NGF) isolated from mouse submaxillary gland. Our EIA system is based on the sandwiching of antigen between anti-mouse beta NGF antibody IgG coated on a polystyrene plate and biotinylated anti-mouse beta NGF antibody IgG. The bound antibody complex was quantified with streptavidin linked-beta-D-galactosidase (beta-D-galactosidase, EC 3.2.1.23). With this system NGF concentrations as low as 0.02 pg/well (corresponding to 8 x 10(-19) mol) could be measured reproducibly. The sensitivity of this EIA system permitted the quantification of endogenous immunoreactive beta NGF in rat serum. The mean level in serum of male rats (153.2 pg/ml) was found to be almost the same as that of female rats (127.6 pg/ml).

Animals↗
PubMed1987

[A case of breast cancer with a chondrosarcomatous appearance].

A case of a breast tumor which showed the appearance of invasive ductal carcinoma and chondrosarcoma is reported. The patient was a 36-year-old female. Simple mastectomy and lymph node dissection were performed for the tumor. Local recurrence and metastases to the contralateral breast, lymph nodes, subcutaneous tissue, and bones arose after the operation. She died of the disease 2 years and 3 months after the operation. It is thought that this tumor had formed as a result of metaplasia of the carcinomatous tissue, since a histological transition between the carcinoma and sarcoma was demonstrated.

Adult↗