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Biomedical subjects

T Maeda

Publications and source records attributed to T Maeda.

At least 919 records · Page 51Linked to original sources
PubMed1990

[CT and sonographic diagnosis of retained surgical sponge].

Seven cases of pathologically proven retained surgical sponge were reviewed and classified into four types, depending on CT and US findings. Type I: CT shows a mass with tiny gas bubbles, and sonogram shows an echogenic area with strong posterior shadow. Type II: CT shows an irregular high density mass with no gas bubble, and sonogram shows an echogenic area with strong posterior shadow. Type III: CT shows a low density mass with irregular internal high density areas, and sonogram shows a cystic mass with zigzag internal components. Type IV: CT shows an elliptic high density mass with low density area internally. Judging from the experiment and operative findings, these patterns were decided by the number and status of the gauze, volume of the exudate and hematoma, and status of the granulation. The author concludes that these characteristic CT and US findings, together with a history of surgery, permit the correct diagnosis of retained surgical sponge.

Adult↗
PubMed1990

Structural and functional characterization of human aromatase P-450 gene.

The gene encoding aromatase P-450 (CYP XIX) has been isolated from two types of human genomic DNA libraries. It spans at least 70 kb and consists of 10 exons. The translational initiation site and the termination site are located in exon 2 and exon 10, respectively. The promoter region of the gene contains a TATA box, a CAAT box and two putative AP-1 binding sites beginning at -28, -83, -55 and -68 bp, respectively, from the transcriptional initiation site. In addition, a palindromic nucleotide sequence is observed between -209 and -196 and two types of repetitious hexanucleotide (consensus: AATGAA and CCATAAGG) are also present within the regions between -485 and -433 and between -358 and -331. Transient expression studies of chloramphenicol acetyltransferase constructs bearing various lengths of 5'-flanking region of the gene show that the region between -500 and -243 contains negative cis-acting element(s), whereas the region between -242 and -183 is required for efficient transcriptional activity. Northern blot analysis demonstrates that the expression of aromatose P-450 gene is remarkably stimulated by treatment of cells with 12-O-tetradecanoyl-phorbol 13-acetate. By chloramphenicol acetyltransferase assay the region up to nucleotide position -242 relative to the transcriptional initiation site is shown to participate in the transcriptional responsiveness to this phorbol ester.

Amino Acid Sequence↗
PubMed1990

Switch circular DNA formed in cytokine-treated mouse splenocytes: evidence for intramolecular DNA deletion in immunoglobulin class switching.

We have characterized circular DNA in mouse splenocytes treated with the mitogen lipopolysaccharide (LPS) and various cytokines, including transforming growth factor beta (TGF-beta) and interleukin 4 (IL-4). Using probes of immunoglobulin heavy chain constant genes (CH), excision products of class switch recombination were identified. The majority of the clones contained the 3' portion of the switch mu (S mu) region and the 5' portion of other switch regions. Some clones contained 3'-S gamma sequences instead of 3'-S mu. This indicates that isotype switching may occur not only from C mu, but also from one of the C gamma genes to other CH genes further down-stream. In the presence of LPS, the cytokine TGF-beta enhanced the detection of 5'-S alpha-positive clones, while the lymphokine IL-4 enhanced 5'-S gamma 1 positives. The data support the notion that TGF-beta and IL-4 can direct isotype-specific class switching.

Animals↗
PubMed1990

Occult papillary carcinoma of the thyroid. A study of 408 autopsy cases.

On examination of the thyroid glands in 408 consecutive autopsy cases, 64 occult papillary carcinomas (OPC) were found in 46 cases (11.3%) whose age ranged from 16 to 82 years. Their incidence was 26 of 247 (10.5%) in male and 20/161 (12.4%) in female cases. No definite correlation was found between the incidence of carcinoma and sex or age. All 64 carcinomas were less than 7.7 mm in diameter. They exhibited nuclear characteristics of papillary carcinoma although their growth patterns were "follicular" in the tumors less than 1 mm, and "papillary" in 70% of the tumors more than 3 mm in diameter. The carcinomas were classified into three types according to the presence or absence of capsular formation and fibrosis: encapsulated tumors (ET), nonencapsulated sclerosing tumors (NEST), and nonsclerosing tumors (NST). The NEST (28 tumors) and NST (26 tumors) were found in persons of all ages, whereas ET (ten tumors) were found only in those of older than 53 years. The mean tumor diameters of the three types, 4.57 mm for ET, 2.10 mm for NEST, and 0.85 mm for NST, were significantly different. These findings suggested that papillary carcinomas arose as minute carcinomas showing follicular pattern at any age as NST and then changed to NEST and ET, and papillary pattern became prominent if the tumors continued to grow. Very minute carcinomas were detected in serial sections of two of 27 fibrosclerotic nodules. Occult papillary carcinomas were found at significantly high incidence in cases with adenomatous goiter.

Adolescent↗
PubMed1990

Specific [125I]brain natriuretic peptide-26 binding sites in rat and pig kidneys.

Specific binding sites for porcine brain natriuretic peptide-26 (BNP-26), a member of the atrial natriuretic peptide family (ANPs), were investigated in the kidney by using receptor autoradiographic and membrane binding techniques with [125I]BNP-26. The binding sites were discretely localized in rat and porcine kidney areas corresponding anatomically to the glomeruli and inner medulla. There were no differences between the localization of [125I]BNP-26 and [125I]alpha-rat ANP binding sites in the kidney. [125I]BNP-26 binding to solubilized membranes from isolated glomeruli of the rat kidney was saturable, and a single class of high-affinity sites was labeled with a KD of 372 pM. The radioligand bound to two sites in solubilized inner medullary membranes of the rat, a low-affinity site with a KD of 30 nM, and a high-affinity site with a KD of 33 pM. The rank order of potency to inhibit binding was BNP-26 = alpha-rat ANP-(1-28) greater than atriopeptin III (ANP-(103-126)) much greater than atriopeptin I (ANP-(103-123)) greater than des-Cys105,Cys121- ANP-(104-126). Thus, [125I]BNP-26 presumably recognizes ANP receptors in the kidney. The possibility that BNP-26 regulates, as a circulating hormone, kidney functions by binding to ANP receptors would have to be considered.

Animals↗
PubMed1990

Cholinesterase activity in terminal Schwann cells associated with Ruffini endings in the periodontal ligament of rat incisors.

A nonspecific cholinesterase activity was demonstrated in terminal Schwann cells associated with Ruffini endings in the periodontal ligament of rat incisors at the light and electron microscopic levels. The terminal Schwann cells are ultrastructurally characterized by a well-developed Golgi apparatus and rough endoplasmic reticulum. The cells in this study were positive for nonspecific cholinesterase, whereas ordinary Schwann cells associated with more proximal nerve fibers reacted negatively. The reaction products were densely deposited in the cisternae of the rough endoplasmic reticulum and along the nuclear envelop. A moderately intense labeling was found in the cytoplasmic extensions, in which the reaction products gathered in caveolae and vesicles. These findings indicate that nonspecific cholinesterase is a useful marker to distinguish terminal Schwann cells from ordinary Schwann cells and that the enzyme may be synthesized in the rough endoplasmic reticulum and conveyed toward the axon terminals. Since this enzyme has been known to be shared by the inner bulb of Pacinian corpuscles and the lamellar cells of Meissner's corpuscles, its possible involvement in mechanoreceptive functions in these specialized Schwann cells deserves further investigation.

Animals↗
PubMed1990

Assessment of bilirubin clearance capacity of a newly developed ion-exchange adsorption column and its possible use as a supportive therapy in hepatorenal syndrome.

We assessed the bilirubin reduction capacity of three different types of devices in vitro: a high-permeable membrane column for double-filtration plasmapheresis (DFP) (Evaflux 2A, Kuraray, Japan), and non-coated charcoal column for hemoperfusion (HP) (N-180, Asahi Medical, Japan), and ion-exchange columns for plasma adsorption (PA) (BR-350, Asahi Medical, Japan, and B-001, Kuraray, Japan). A column for DFP reduced the concentration of low-molecular proteins effectively such as plasma bilirubin and bile acids in an albumin-dependent manner. A charcoal column adsorbed low-molecular substances preferentially. But in these two columns, the loss of fibrinogen is a limiting factor for determining the processing plasma volume. Ion-exchange columns for PA adsorbed bile acids, disconjugated bilirubin, and monoconjugated bilirubin more efficiently compared with delta-bilirubin and unconjugated bilirubin. Pretreatment of the column with heparin reduced the loss of fibrinogen to less than 10%. We applied the BR-350 ion-exchange column in vivo for treatment of three patients with hyperbilirubinemia. After treatment, an alcoholic hepatitis patient with the hepatorenal syndrome (HRS) recovered from acute renal failure. However, in a patient with primary biliary cirrhosis and in a patient with fulminant hepatitis, the decrease of serum bilirubin was transient and no obvious beneficial responses were noted. The capacity and ability of the BR-350 column to adsorb plasma bilirubin was shown sufficient to treat deeply jaundiced patients, because 4 liters of the plasma of a patient with 108 mg/dl of initial total bilirubin concentration was able to be processed continuously without an obvious decrease in bilirubin adsorption capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adsorption↗
PubMed1990

IgE-positive epidermal Langerhans cells in allergic contact dermatitis lesions provoked in patients with atopic dermatitis.

To see whether or not IgE-bearing epidermal Langerhans cells are specific to skin lesions of atopic dermatitis (AD), we performed immunohistochemical and immunoelectron microscopic examinations of dinitro-chlorobenzene (DNCB) contact dermatitis lesions provoked in uninvolved skin of eight patients with AD. In all of the eight examined, IgE-positive epidermal Langerhans cells were observed in the DNCB dermatitis lesions. Typical staining of anti-IgE was absent in the epidermis of normal-appearing skin of five patients with AD. Thus, it is likely that IgE positive epidermal Langerhans cells non-specifically occur in different eczematous diseases provoked in patients with AD.

Adolescent↗
PubMed1990

The tumour-localizing properties of porphyrin derivatives.

The tumour-localizing abilities of various kinds of porphyrin derivatives in tumour-bearing hamsters were assessed by nitrogen-pulsed laser spectrofluorometry (N2-PLS). On examination of porphine derivatives (from haemoglobin), it was found that the dimer and acetylated and amidated compounds had a high affinity for tumour tissue; the dimer and hydroxylated compound of phorbine derivatives (from chlorophyll) also showed a high affinity. Furthermore, of the metalloporphines (gallium, zinc and indium complexes), those which contained hydrophilic groups showed a high affinity for tumour tissue; of the metallophorbines (gallium, zinc and indium complexes), those which contained hydrophobic groups showed a high affinity. A correlation was found between the side-chain structure of the porphyrins and metalloporphyrins and their affinity for tumour tissue.

Animals↗
PubMed1990

Adenylyl cyclase is dispensable for vegetative cell growth in the fission yeast Schizosaccharomyces pombe.

Disruption of the cyr1 gene of Schizosaccharomyces pombe, which encodes adenylyl cyclase, did not confer lethality to fission yeast cells, although they grew 40% slower than wild-type strains in complete medium. These cells contained no measurable amount of cAMP and no adenylyl cyclase activity. When h+ and h- cyr1 disruptants were mixed, they underwent mating even in rich medium. Propagation of homothallic cyr1 disruptants was difficult, probably because such cells readily mate and produce asci and thus stop growing. A greater than 10-fold increase in the amount of cyr1 mRNA was observed when cloned cyr1+ was introduced into Sch. pombe cells on a multicopy plasmid. The total adenylyl cyclase activity was similarly high in these transformants. However, the level of intracellular cAMP was hardly affected. Evidence suggests that this was not due to increased phosphodiesterase activity. Thus, cAMP level in growing fission yeast cells appears to be regulated not by the amount of adenylyl cyclase protein but by a feedback mechanism at the enzyme level. The cAMP level fell by approximately 50% under nitrogen starvation, which triggers sexual development in Sch. pombe. We suggest that fission yeast controls the level of intracellular cAMP primarily to regulate sexual development rather than to drive or arrest the cell cycle.

Adenylyl Cyclases↗
PubMed1990

Acute aggregation of serotonin-immunoreactive platelets in the injured spinal cord of rat and change of serotonin content in the neural fibers.

Serotonin (5-HT) immunoreactivity was investigated at the injury site of the rat spinal cord by light and electron microscopic immunohistochemistry. The animals were perfused with fixative immediately, 1-5 min, 7-60 min, and 1-48 h after a 3-sec extradural compression of the thoracic cord with a Sugita aneurysm clip. Five minutes after injury, abundant hemostatic plugs containing platelets with high 5-HT immunoreactivity appeared at the traumatized cord segment, whereas 5-HT-containing varicose fibers became less immunoreactive. The 5-HT-immunoreactive platelets initially were localized to the periphery of the hemostatic plugs. By 30 min after injury, the platelets had decreased 5-HT, but neural fibers and terminals began to show increased 5-HT immunoreactivity, which increased and lasted as long as 48 h. These results indicate that platelets contributed to the initial 5-HT concentration increase at the injury site but that later 5-HT accumulation occurred in the neural elements.

Animals↗
PubMed1990

Isolation and purification of a non-A, non-B hepatitis-associated microtubular aggregates protein.

Blood-borne type non-A, non-B (NANB) hepatitis-associated microtubular aggregates protein was isolated and partially sequenced. The microtubular aggregates were isolated from the hepatocytes of NANB-infected chimpanzees and were found to have a buoyant density in sucrose solution of 1.21 to 1.23 g/ml. A single protein, recognized by our anti-microtubular aggregates monoclonal antibodies, was found to have an Mr of 44,000 (p44). This p44 protein was not found in uninfected chimpanzees. We determined a partial amino acid sequence for p44, and showed that it has no homology to any known proteins.

Amino Acid Sequence↗
PubMed1990

Cloning, sequencing and expression in Escherichia coli of cDNA for a non-A, non-B hepatitis-associated microtubular aggregates protein.

A 1.7 kb cDNA encoding a novel antigen (p44; apparent Mr 44K) associated with non-A, non-B (NANB) hepatitis, was isolated from the hepatic cDNA library of a chimpanzee infected with NANB hepatitis. The library was screened with a monoclonal antibody against this antigen. The cDNA cloned contained an open reading frame encoding a 444 amino acid protein with an Mr calculated to be 50,468. The cDNA hybridized to a 1.9 kb mRNA obtained from chimpanzee hepatocytes infected with either the NANB or hepatitis delta viruses. It hybridized weakly to mRNA from hepatitis B virus-infected hepatocytes, and not at all to mRNA from normal chimpanzee hepatocytes. Southern blot analysis revealed that p44 is a host protein in chimpanzees, and that an identical gene exists in the human genome.

Amino Acid Sequence↗
PubMed1990

Effects of butenafine hydrochloride, a new benzylamine derivative, on experimental dermatophytosis in guinea pigs.

Butenafine hydrochloride, N-4-tert-butylbenzyl-N-methyl-1-naphthalenemethylamine hydrochloride (butenafine), is a novel antifungal agent of the class of benzylamine derivatives. Butenafine was investigated for its activity against guinea pig dermatophytosis caused by Trichophyton mentagrophytes or Microsporum canis in comparison with those of naftifine, tolnaftate, clotrimazole, and bifonazole. Topical butenafine showed excellent efficacy against dermatophytosis when it was applied once daily, and the effect was superior to those of all four reference drugs. When applied once at 24 or 48 h before infection, the drug exhibited excellent prophylactic efficacy against experimental T. mentagrophytes infection. The concentrations of butenafine in animal skin at 24 and 48 h after application of 0.2 ml of a 1% solution were several hundred times higher than those required to kill T. mentagrophytes and M. canis. The good efficacy of butenafine against dermatophytosis may be attributable to its fungicidal activity and long retention in the skin after topical application.

Animals↗
PubMed1990

Effects of butenafine hydrochloride, a new benzylamine derivative, on experimental tinea pedis in guinea pigs.

Butenafine is a new antifungal benzylamine. The efficacy of butenafine was investigated in an experimental tinea pedis model in guinea pigs, which is pathologically similar to natural infections in humans. Butenafine (0.1 ml) in 0.2 to 1.0% solutions was applied to the site of infection. Treatment was started on day 10 postinfection and was continued for 20 days. Butenafine applied once daily exhibited excellent dose-related therapeutic efficacy. The efficacy of butenafine was significantly superior to those tolnaftate, clotrimazole, and bifonazole.

Animals↗
PubMed1990

Reduction of proteinuria by adrenalectomy and its restoration by glucocorticoids in rats bearing functioning pituitary tumor.

Intense proteinuria in rats bearing a functioning pituitary tumor MtT SA5 was considered to be evoked by overproduction of albumin due to elevated serum growth hormone (GH). The present study revealed a striking reduction of proteinuria by bilateral adrenalectomy. Supplementation for about 6 weeks with glucocorticoids to adrenalectomized tumor-bearing rats again induced marked proteinuria, but supplementation with mineralocorticoids failed to augment proteinuria. An analysis of systemic blood pressure and renal blood flow did not yield any conclusive result. In spite of an assumption that glucocorticoids enhance GH production of the tumor based on the presence of glucocorticoid receptor in the tumor tissue, no difference was found in serum GH levels between glucocorticoid- and mineralocorticoid-supplemented adrenalectomized rats. The mechanism remains to be clarified, but modification of glomerular permeability or a change in glomerular hydraulic pressure by glucocorticoids might be considered.

Adrenalectomy↗
PubMed1990

Application of the immunohistochemical method as a predictive assay in radiotherapy of squamous cell carcinoma of oropharynx and hypopharynx.

We analyzed various subsets of lymphocytes infiltrated into cancer tissues from 15 patients (10 cases of oropharyngeal cancer and 5 of hypopharyngeal cancer) before treatment and after irradiation with approximately 10 Gy (1,000 rad) and 30 Gy by the method of biotin-avidin-horseradish peroxidase using mouse monoclonal antibodies. The infiltration was graded (marked) to - (none). In 3 cases, tumor-infiltrating lymphocytes were remarkably increased at the delivery of a small dose of irradiation (approx. 10 Gy): 2 of them showed remarkable radiosensitivity, and the lymphocyte subpopulation of the cancer tissue was mainly composed of Leu-3a + 3b-positive and Leu-8-negative lymphocytes (helper inducer T lymphocytes or delayed-type hypersensitivity cells). On the other hand, the third one proved to be rather radioresistant, and the lymphocyte subpopulation was mainly composed of Leu-14-positive lymphocytes (B lymphocytes). These findings indicate that the analysis of the lymphocyte subpopulation infiltrating into cancer tissues at the delivery of small doses of irradiation is applicable as a predictive assay in radiotherapy of squamous cell carcinoma of the oropharynx and hypopharynx.

Aged↗