Search PubMed⌕ Search

Biomedical subjects

K Shimada

Publications and source records attributed to K Shimada.

At least 1,189 records · Page 66Linked to original sources
PubMed1988

Structure of the mouse serum amyloid P component gene.

A genomic DNA clone corresponding to the mouse serum amyloid P component (SAP) has been isolated and characterized for the first time. The numbers of exons, the relative sites of intron/exon junctions, and the size of the coding region for mature SAP protein are all in complete agreement with those of the human SAP gene. In the 5'-flanking region of the mouse SAP gene, there is a small DNA segment (43-base pairs) which is highly homologous with the corresponding region of the human SAP gene. However, most parts of the 5'-flanking regions are not conserved between the mouse and human SAP genes, and several phorbol ester-responsive element-like sequences are present only in the mouse SAP gene.

Amino Acid Sequence↗
PubMed1988

Acute-phase response of mRNAs for serum amyloid P component, C-reactive protein and prealbumin (transthyretin) in mouse liver.

Acute-phase response of mRNAs for serum amyloid P component (SAP), C-reactive protein (CRP) and prealbumin was examined in C57BL/6 mouse liver by hybridization to specific cDNA probes. Although the level of SAP mRNAs in the unstimulated mouse was about one-tenth of that of CRP mRNAs, it increased up to 60-fold during the first 20 hr, and returned gradually to the original level at 69 hr after the administration of Escherichia coli lipopolysaccharide. On the other hand, the level of CRP mRNA rapidly increased up to 6-fold during the first 4 hr, and reverted to the original level as early as at 20 hr. In contrast, the level of mRNA for prealbumin decreased to about 0.5-fold during the first 20 hr, recovered and increased up to 1.6-fold of the original level during 32 to 69 hr.

Animals↗
PubMed1988

Structural organization of the mouse cytosolic malate dehydrogenase gene: comparison with that of the mouse mitochondrial malate dehydrogenase gene.

We cloned and characterized a mouse cytosolic malate dehydrogenase (cMDHase) (EC 1.1.1.37) gene, which is about 14 x 10(3) base-pairs long and is interrupted by eight introns. The 5' and 3' flanking regions and the exact sizes and boundaries of the exon blocks, including the transcription-initiation sites, were determined. The 5' end of the gene lacks the TATA and CAAT boxes characteristic of eukaryotic promoters, but contains G + C-rich sequences, one putative binding site for a cellular transcription factor, Sp1, and at least two major transcription-initiation sites. The sequences around the transcription-initiation sites are compatible with the formation of a number of potentially stable stem-loop structures. We compared structural organization of the mouse cMDHase gene with that of the previously characterized mouse mitochondrial MDHase (mMDHase) gene, and found that the conservation of intron positions spreads across much of the two genes. This result suggests that a common ancestral gene for the cytosolic MDHase and the mitochondrial MDHase was broken up by introns, before the divergence. We also compared the nucleotide sequence of the promoter region of the mouse cytosolic MDHase gene with that of the other three mouse genes coding for isoenzymes participating in the malate-aspartate shuttle, i.e. mitochondrial MDHase, cytosolic and mitochondrial aspartate aminotransferases (cAspATase and mAspATase). We found that highly conserved regions are present in the promoter region of the cAspATase gene.

Amino Acid Sequence↗
PubMed1988

Structural organization of the mouse mitochondrial malate dehydrogenase gene.

Structural organization of the mouse mitochondrial malate dehydrogenase (EC 1.1.1.37) gene was determined by analyzing a genomic DNA fragment isolated from a cosmid library. The gene is 12,000 base-pairs long and contains nine exons interrupted by eight introns of various sizes. The 5' and 3'-flanking regions, and the exact sizes and boundaries of the exon blocks including the transcription-initiation sites were determined. In the 5'-flanking region, there is neither a TATA box nor a CAAT box. Instead of these sequences, there are six copies of the GGGCGG or CCGCCC sequence, which is a potential binding site for the transcription factor, Sp1. The 5'-flanking region up to about 600 nucleotides is G + C-rich (65%) and contains sequences compatible with the formation of a number of potentially stable stem-loop structures. S1 nuclease mapping and primer extension analysis demonstrated that transcription of the mitochondrial malate dehydrogenase gene initiates at multiple sites. Comparison of the nucleotide sequence of the promoter region of the mitochondrial malate dehydrogenase gene with that of the mitochondrial aspartate aminotransferase gene, revealed that there are several highly conserved regions between these two mitochondrial enzyme genes participating in the malate-aspartate shuttle.

Amino Acid Sequence↗
PubMed1988

Structural organization of the mouse aspartate aminotransferase isoenzyme genes. Introns antedate the divergence of cytosolic and mitochondrial isoenzyme genes.

We have cloned and characterized a mouse cytosolic aspartate aminotransferase (AspAT) (EC 2.6.1.1) gene, which is about 32,000 base-pairs long and is interrupted by eight introns. The 5' and 3'-flanking regions, and the exact sizes and boundaries of the exon blocks, including the transcription-initiation sites, were determined. The 5' end of the gene lacks the TATA and CAAT boxes characteristic of eukaryotic promoters, but contains G + C-rich sequences, three putative binding sites for a cellular transcription factor, Sp1, and multiple transcription-initiation sites. The sequences around the transcription-initiation sites are compatible with the formation of a number of potentially stable stem-loop structures. We compared the structural organization of the mouse cytosolic AspAT gene with that of the mouse mitochondrial AspAT gene, which has nine introns. We found that the promoter regions share a high level of homology and five of the introns are at identical places. This close matching leads to the tentative conclusion that the introns were in place before the divergence of cytosolic and mitochondrial isoenzyme genes.

Amino Acid Sequence↗
PubMed1988

Cloning and sequence analysis of a cDNA for lymphocyte proliferation potentiating factor of rabbit polymorphonuclear leukocytes: identification rabbit interleukin 1 beta.

Complementary DNA for a rabbit PMN-derived lymphocyte proliferation potentiating factor (PMN factor) was cloned from a cDNA library constructed from poly(A)+RNA of early inflammatory exudate PMN. Oligodeoxyribonucleotides as probes for cloning were synthesized according to the previously reported amino acid sequence of the purified PMN factor. This cDNA encodes a 268-residue protein which is homologous to the established structures of human IL 1 beta (74%0 or murine IL 1 beta (71%). The NH2-terminal amino acid sequence of the endogenously produced PMN factor indicates that the mature molecule is made up of carboxy terminal 152 amino acids of the precursor molecule. Taking into consideration the previous studies on biological activities, this cloned PMN factor is therefore considered to be rabbit IL 1 beta.

Amino Acid Sequence↗
PubMed1988

Morphology of the mandibulo-stylohyoid ligament in human adults.

The mandibulo-stylohyoid ligament is a consistently occurring connective tissue band or sheet that courses between the angle of the mandible and the stylohyoid ligament. Previously, in a few instances it has been variously named and described as a thickening of deep cervical fascia. Recently, Shimada et al. (1986) described the connective tissue thickening and named it the mandibulo-stylohyoid ligament because of its arrangement and attachments. In the present study the ligament was dissected in 99 adult cadavers (both white and black, 98 right sides, 95 left sides). It was present in all of the specimens examined and has been classified into three types according to refinements in its morphology. Type 1: The ligament was a thick, separate band that coursed from the region of the angle of the mandible to the stylohyoid ligament. Type 2: The ligament had the same attachments as Type 1 but was more extensive, being continuous with the stylomandibular ligament. Type 3: The ligament had the same attachments as Type 1 but was thin and less well developed. The Type 1 arrangement occurred 41% of the time, Type 2, 37% of the time, and Type 3, 22% of the time. The consistency and arrangement of the ligament suggests an important role of additional structural support in the region of the angle of the mandible and hyoid bone.

Humans↗
PubMed1988

An autosomal dominant mutation of facial development in a transgenic mouse.

We have created a transgenic mouse which showed an autosomal dominant mutation of facial development. This facial malformation was characterized by a short snout and a twisted upper jaw. All offspring showing the dysmorphic phenotype carried the injected gene. In order to analyze the primary cause of this mutation, newborn mice and embryos were examined. The outcome was that the malformation of nasal and premaxillary bone was not the primary defect but was a secondary event. The primary cause of this dysmorphism was a developmental defect in the first branchial arch. Genomic DNA fragments flanking the insertion site of this mutant mouse were cloned. Using these fragments, we have assigned the integration site to chromosome 13. The gene responsible for a previously reported mutant mouse, one which also has a short snout, is also reported to be on chromosome 13. In the fragments flanking the insertion site of the transgenic mouse, at least one fragment was highly conserved in mammals. These results indicate that this malformation is due to the insertional disruption of a host gene. However, the possibility that this mutation is caused by an inappropriate expression of the injected gene still remains to be investigated.

Animals↗
PubMed1988

Blue rubber bleb naevus syndrome.

An autopsy case of blue rubber bleb naevus syndrome (BRB-NS) is reported. There was the usual occurrence of cavernous haemangioma in the skin and intestine and cardiac involvement by a haemangiomatous lesion might have directly led to the patient's death. By light and electron microscopy, all the haemangiomatous lesions examined were cavernous with the exception of the cardiac tumour which was a mixed-vessel (capillary and cavernous) type of a haemangioma. These findings indicate that any vascular tumour-like lesions may occur in BRBNS. The principal combination of haemangiomas in the skin and intestine in BRBNS regardless of their type is the typical feature of this syndrome.

Female↗
PubMed1988

Clinical analysis of the small kidney associated with VUR.

Analysis was performed on the clinical features of children with VUR who had one or two kidneys that were at least -2 SD smaller than normal for age of its renal ratio. The prevalence of the small kidney was 15.6% (97/623 children). Of 107 small kidneys, 87 (82%) were associated with moderate (grade IV) to severe (grade V) reflux and renal scarring was evident on 95 kidneys (88%). About half of the kidneys were diagnosed as scarred atrophy and 40% as congenital hypoplasia. The renal growth after antireflux surgery was evaluated by the change of the renal ratio and it was found that about three-fourths remained small during the pre- and postoperative periods. Accelerated growth was only exceptional.

Adolescent↗
PubMed1988

Plasma levels of immunoreactive mesotocin and vasotocin during oviposition in chickens: relationship to oxytocic action of the peptides in vitro and peptide interaction with myometrial membrane binding sites.

Plasma concentrations of immunoreactive vasotocin (AVT) and mesotocin (MT) were measured periodically before and subsequent to spontaneous oviposition in conscious chickens. The concentrations of AVT and MT approximately an hour prior to oviposition were 5.2 +/- 1.1 microU/ml and 14.7 +/- 5.1 pg/ml, respectively. Plasma AVT levels increased abruptly at oviposition (25.1 +/- 3.3 microU/ml) and decreased to 5.0 +/- 0.6 microU/ml within 30 min postoviposition. Significant changes in MT were not observed. The data indicate that AVT is selectively released during oviposition. The uterus was removed immediately after oviposition and the oxytocic potencies of several peptides were tested on muscle strips in vitro. The order of oxytocic potencies was AVT greater than or equal to arginine vasopressin (AVP) much greater than MT = pressinoic acid. Partially purified membranes were prepared from separate portions of the uteri used in the oxytocic assay. [3H]arginine8 vasopressin, [3H]AVP, bound to membranes saturably (Bmax = 17 fmol/mg protein) and with high affinity (Kd = 0.7 nM). The rank order of potency of the peptides in displacing [3H]AVP from the binding sites was the same as in the oxytocic assay which suggests that the [3H]AVP binding sites in uterine membranes represent physiological receptors that interact with AVT during oviposition.

Animals↗
PubMed1988

Changes in plasma levels of prolactin and estradiol, nutrient intake, and time spent nesting during the incubation phase of broodiness in the Chabo hen (Japanese bantam).

The plasma concentrations of prolactin (PRL) and estradiol, time spent nesting, consumption of feed and water, body weight, and hematocrit were measured during egg laying, incubating, and brooding of the chicks in a Japanese strain of dwarf bantam hen, Chabo. Plasma levels of PRL increased before incubation, were maintained at high levels during incubation, and decreased rapidly at the onset of hatching the young. The concentration of estradiol decreased before incubation and was maintained at low levels when circulating levels of PRL were high. During incubation, hens spent greater than 95% of the day on the nest, reduced their daily intake of feed and water by 63 and 78%, respectively, and decreased their body weight by 19% by the end of incubation. Thus, Chabo hens show a mode of incubation behavior similar to that reported in larger chickens. The temporal changes between nutrient intake and plasma levels of PRL at the start and end of incubation behavior suggested that changes in nutrient intake may not cause changes in the concentration of PRL, whereas the association between increased levels of PRL and decreased levels of estradiol suggested that they may be causally associated. Plasma levels of PRL also appeared to be associated with time spent on the nest.

Animals↗
PubMed1988

Diuresis mediated by the superior laryngeal nerve in rats.

Diuresis mediated by the superior laryngeal nerve (SLN) was investigated using pentobarbital-anesthetized rats. A marked increase in urine flow was induced by application of water to the larynx. The diuretic effect of water was conspicuous during the first 30 min after the application and lasted for more than 1 hr. In contrast, a 160 mM solution of NaCl produced only slight diuresis. After bilateral sectioning of the SLNs, water-induced diuresis was considerably reduced. The results suggest that water fibers contained in the SLN may make a major contribution to the diuresis.

Animals↗
PubMed1988

Expression of tissue-specific genes in transgenic mice.

The ability to introduce cloned genes into mouse germ line has been used for analyzing cis-acting DNA sequences involved in tissue-specific and developmental regulation of the introduced gene. Using this system we have attempted to produce a transgenic mouse model for human dominantly inherited disease, familial amyloidotic polyneuropathy. Recently the mutant transthyretin gene which is considered to be responsible for this disease has been cloned and well characterized at molecular level. We have produced transgenic mice by microinjecting human mutant gene. Amyloid deposition was observed in the mucosa of alimentary tract and renal glomeruli, suggesting that this approach is successful in establishing the mouse model for human genetic disease. In addition, these experiments suggest that the expression of the mutant gene is regulated normally during developmental process and that the cause of adult onset is not due to the dysregulation of this gene expression.

Amyloidosis↗
PubMed1988

Frantz's tumor: a papillary and cystic tumor of the pancreas in girls.

Four girls with Frantz's tumor, a papillary and cystic tumor of the pancreas, are studied and discussed in comparison with 112 cases in the literature, including 58 Japanese cases. The neoplasms occur predominantly in girls and young women. Up to recently, the tumors have possibly been misclassified as nonfunctioning islet cell tumor or carcinoma, acinar cell carcinoma, papillary cystadenocarcinoma, or pancreatoblastoma according to microscopic findings and frequently have been managed with aggressive surgery such as pancreatoduodenectomy. The tumors are well encapsulated and the cut surfaces show characteristically solid and hemorrhagic-necrotic patterns. Ultrasonography and CT scan are the most useful tools for the diagnosis. The neoplasms usually behave like a very low-grade malignancy, so that complete removal is the treatment of choice for the tumor arising anywhere in the pancreas. Immunochemical and electron microscopic studies can differentiate Frantz's tumor from other neoplasms and also suggest that the tumors originate from primordial cells or multipotential stem cells capable of differentiating into both exocrine and endocrine lines.

Adolescent↗
PubMed1988

Renal growth and progression of reflux nephropathy in children with vesicoureteral reflux.

We analyzed renal growth and development of renal scars in 754 children with primary and 169 with secondary vesicoureteral reflux. The incidence of a small kidney was 15.5 per cent in the primary and 24.1 per cent in the secondary groups. About three-fourths of the small kidneys remained small from the first examination through followup. Catch-up renal growth was only exceptional. New scars or progression of previous scarring was observed in 7.4 and 30 per cent of the primary and secondary groups, respectively. Factors that promote formation of new scars are high grade vesicoureteral reflux, recurrent urinary tract infections and abnormal bladder function that results in high pressure reflux. We emphasized the importance of precise examination of the lower urinary tract. An early antireflux operation should be performed on children with severe reflux or recurrent urinary tract infections.

Child↗