Biomedical subjects

E Ishikawa

Publications and source records attributed to E Ishikawa.

At least 73 records · Page 4Linked to original sources

PubMed1995

Noncompetitive enzyme immunoassay (hetero-two-site enzyme immunoassay) for gamma 2-melanocyte-stimulating hormone (gamma 2-MSH) and measurement of immunoreactive gamma 2-MSH in plasma of healthy subjects.

A noncompetitive enzyme immunoassay (hetero-two-site enzyme immunoassay) for gamma 2-melanocyte-stimulating hormone (gamma 2-MSH) was developed. gamma 2-MSH (1-12) was biotinylated, trapped onto an anti-gamma 2-MSH (1-12) IgG-coated polystyrene bead, eluted at pH 1 after washing to eliminate other biotinylated substances, and measured using two streptavidin-coated polystyrene beads and affinity-purified anti-gamma 2-MSH (1-12) Fab'-peroxidase conjugate. The detection limit of gamma 2-MSH (1-12) was 10-30 amol (16-48 fg)/assay and 130-400 fmol (210-630 pg)/L of plasma. There was little or only slight cross reaction with alpha-MSH, beta-MSH, and gamma 1-MSH. By this immunoassay, the concentration and molecular size of immunoreactive gamma 2-MSH in plasma of healthy subjects were examined, and the results were compared with those by competitive enzyme immunoassay. Immunoreactive gamma 2-MSH measured by competitive enzyme immunoassay was a mixture of substances with high molecular weights (100-500 kDa), and its concentration was calculated to be 50-60 pmol/L using gamma 2-MSH (1-12) as standard. Immunoreactive gamma 2-MSH detected by the noncompetitive enzyme immunoassay after removal of high molecular weight substances was not homogeneous and smaller than gamma 2-MSH (1-12), and its concentration was approximately 1 pmol/L. The exact nature of these immunoreactive gamma 2-MSHs remains to be elucidated. gamma 2-MSH (1-12) added to plasma was degraded rapidly, and the concentration of gamma 2-MSH (1-12) was very low, if any, in plasma of healthy subjects.

Adult↗

PubMed1995

Alpha fetoprotein-producing acinar cell carcinoma of the pancreas showing multiple lines of differentiation.

An alpha fetoprotein (AFP)-producing tumour occurring in the head of the pancreas of a 30-year-old woman is reported. Histological examination revealed a markedly solid proliferation of tumour cells with prominent nucleoli and occasional luminal structures, some of which contained mucinous material stained with mucicarmine and alcian blue. No squamoid corpuscles were recognized. Immunohistochemistry showed intense positivity for lipase trypsin, and AFP basically, and single cells were also positive for carcino-embryonic antigen, CA19-9, synaptophysin and neuron-specific enolase. Pancreatic hormone-positive cells were absent. Electron microscopical examination revealed numerous granules of variable sizes in the tumour cells, which were considered to be zymogen. The tumour is an acinar cell carcinoma with multi-directional differentiation including the ability to produce AFP. Among AFP-positive pancreatic tumours, acinar cell carcinoma and pancreatoblastoma seem to be the most frequent.

Adult↗

PubMed1995

TMP-153, a novel ACAT inhibitor, inhibits cholesterol absorption and lowers plasma cholesterol in rats and hamsters.

Effects of TMP-153, N-[4-(2-chlorophenyl)-6,7-dimethyl-3-quinolyl]-N'-(2,4-difluorophe nyl)urea, on intestinal and hepatic acyl-CoA:cholesterol acyltransferase (ACAT) activities, cholesterol absorption and plasma cholesterol level in rats and hamsters were studied. TMP-153 has IC50 values of around 5-10 nM for the hepatic and intestinal ACAT from various animals. The most potent inhibition was observed in the intestinal ACAT from Golden hamsters (IC50 = 2.3 nM). The inhibition mode of TMP-153 was non-competitive for rat intestinal ACAT. TMP-153 inhibited cholesterol esterification both in human colonic adenocarcinoma cells, LS180, and in human hepatoma cells, HepG2 (IC50 = 150 nM and 330 nM, respectively). [14C]cholesterol and cold cholesterol absorption from the small intestine was markedly inhibited by oral administration of TMP-153 (1 mg/kg) without affecting lymph flow and triglyceride absorption. When the compound was given as a dietary admixture, plasma cholesterol was reduced in rats fed a cholesterol diet (ED50 = 0.25 mg/kg/day), but not in those fed a stock diet. On the other hand, TMP-153 showed more prominent hypocholesterolemic effect in Golden hamsters fed the stock diet (ED50 = 0.81 mg/kg/day) than in those fed the cholesterol diet (ED50 = 8.01 mg/kg/day). In hamsters fed the stock diet, TMP-153 markedly decreased the hepatic unesterified cholesterol in addition to esterified cholesterol content, but did not affect bile flow and the biliary secretion of bile acid and lipids. Different mechanisms for plasma cholesterol lowering by TMP-153 between rats and hamsters was discussed.

Adenocarcinoma↗

PubMed1995

TMP-153, a novel ACAT inhibitor, lowers plasma cholesterol through its hepatic action in golden hamsters.

The mechanism of the hypocholesterolemic action of N-[4-(2-chlorophenyl)-6,7-dimethyl-3-quinolyl]-N'-(2, 4-difluorophenyl) urea (TMP-153), a potent acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor, was studies in Golden hamsters. TMP-153 (0.5-1.5 mg/kg) dose-dependently reduced plasma total- and low density lipoprotein (LDL)-cholesterol without affecting high density lipoprotein (HDL)-cholesterol. TMP-153 markedly reduced the cholesterol influx into the plasma upon intravenous injection of Triton WR-1339. The compound also decreased cholesterol absorption calculated from dietary intake, biliary secretion and the absorption co-efficient. Hepatic cholesterol secretion was calculated by substracting the cholesterol absorption from the cholesterol influx. In hamsters, the liver accounted for 92% of the cholesterol influx with the remaining 8% coming from the intestine, and both were markedly decreased by TMP-153. Thus, it is likely that TMP-153 lowers plasma cholesterol through its hepatic action. In the liver, the compound significantly reduced the unesterified cholesterol content in addition to markedly reducing the content of esterified cholesterol. In accordance with this reduction, the half-life time of [125I]-LDL was significantly shortened by the compound, suggesting an increase in LDL receptors. However, the hepatic cholesterogenesis from [14C]acetate was decreased by TMP-153 treatment. This effect seems to be secondary, since the compound did not inhibit cholesterogenesis from [14C]acetate in HepG2 cells. From the data described above, the contribution of hepatic secretion and intestinal absorption of cholesterol to the plasma cholesterol level in Golden hamsters are discussed.

Animals↗

PubMed1995

Ultrasensitive enzyme immunoassay.

Ultrasensitive enzyme immunoassay methods are reviewed not only for antigens but also for antibodies and haptens with emphasis on factors which limit the sensitivity. Ultrasensitive immunoassays can be developed by noncompetitive solid phase assay systems rather than competitive ones for antigens and antibodies. However, no noncompetitive immunoassays have been available for hapten molecules which cannot be bound simultaneously by two different antibody molecules. This has been overcome by developing methods to derivatize haptens with amino groups so that the derivatized haptens may be measured by two-site noncompetitive assays. For ultrasensitive noncompetitive solid phase immunoassays, the nonspecific binding of labeled reactants (background noise) should be minimized. This has been achieved by developing methods to transfer the complex of analytes and labeled reactants from solid phase to solid phase with minimal dissociation of the complex. Thus, the sensitivity for antigens, haptens and antibodies has been markedly improved and some applications have been made.

Animals↗

PubMed1995

Sandwich capture enzyme immunoassay for water soluble blood group B substance in secretor saliva.

Sandwich capture enzyme immunoassays (EIA I and EIA II) are described. Water soluble B substance was reacted simultaneously with affinity-purified dinitrophenyl goat anti-B IgG and affinity-purified goat anti-B IgG-peroxidase conjugate. The complex formed of B substance, dinitrophenyl IgG and IgG-peroxidase conjugate was trapped onto a polystyrene ball coated with affinity-purified goat anti-dinitrophenyl bovine serum albumin IgG. After washing, peroxidase activity bound to the ball was assayed by fluorometry (the sandwich capture EIA I). In the sandwich capture EIA II, the complex was, after thorough washing, eluted from the ball with dinitrophenyl-L-lysine, and then peroxidase activity in the eluate was assayed. The thorough washing and elution processes improved the sensitivity 3.3-fold, and B substance in saliva samples from type B and AB secretors could be detected 200- to 500-fold more sensitively than hemagglutination inhibition, a method commonly used in forensic practices.

ABO Blood-Group System↗

PubMed1995

Endovascular papillary angioendothelioma-like tumour associated with lymphoedema.

A case of endovascular papillary angioendothelioma-like tumour associated with lymphoedema is described. Microscopically, the tumour was composed of anastomosing vascular channels, some of which contained papillary projections, producing tuft-like or glomeruloid appearances. The dermis also showed moderate lymphoedema and lymphocytic infiltrate. The tumour resembled endovascular papillary angioendothelioma but also had several features that differed from typical examples: occurrence in an old patient and less prominent endothelial hobnail features and lymphocytic infiltrate. Three types of proliferating cells were observed: 1 mature flattened endothelial cells, which were strongly positive for endothelial markers (factor VIII-related antigen, CD31, CD34) and bound ulex europaeus agglutinin 1;2 immature endothelial cells with round nuclei and vacuolated or pale cytoplasm, which were strongly positive for CD31 and muscle-specific actin (HHF35) and focally positive for other endothelial markers; and 3 stromal spindle cells in papillary or glomeruloid areas, which were positive for vimentin, HHF35, and alpha-smooth muscle actin but negative for desmin. The tumour was diploid by flow cytometry. The patient was well without disease twelve months after the excision. We postulate that this tumour was caused by circulatory disturbance, namely lymphoedema associated with syringomyelia and a Charcot's joint.

Aged↗

PubMed1995

Atypical polypoid adenomyomas of the uterus.

We performed a clinicopathological immunohistochemical, ultrastructural, and flow cytometric study on six cases of atypical polypoid adenomyoma of the uterus including one with an adenocarcinoma within it. The tumours occurred in nulliparous women aged 22-48 years (average, 33.0 years); three arose in the uterine corpus, and three in the endocervix. Histologically, they were composed of endometrial glands admixed with a stromal component of interlacing bundles of smooth muscle cells. The glands exhibited varying degrees of architectural and cytological atypia. Most of the stromal cells showed strong staining for HHF35, alpha-smooth muscle actin, and vimentin, and some cells contained desmin. Electronmicroscopy, in one case, confirmed the presence of a well-differentiated smooth muscle component. The stromal component may arise as a result of extensive metaplasia of endometrial stromal cells. Uninvolved endometrium showed ciliated cell metaplasia in three patients, and atypical complex hyperplasia in two. One patient had a well-differentiated adenocarcinoma of endometrioid type arising in an endocervical atypical polypoid adenomyoma. All tumours had a diploid DNA content and relatively small S phase fraction (average, 6.23%). The follow-up periods ranged from 4 to 42 months (average, 13.5 months), and all patients were alive and well. Although the histogenesis of atypical polypoid adenomyoma of the uterus remains uncertain, it is suggested that it may arise because of oestrogen-related factors.

Adenomyoma↗

PubMed1995

Choriocarcinoma in situ: a case at an early gestational stage.

A case of choriocarcinoma in situ arising in an 11 week gestational placenta is reported. Histologically, a localized nodule, measuring 5 mm, of neoplastic trophoblastic proliferation appeared to arise directly from normal stem villi and projected into the intervillous space. The tumour was composed of biphasic cytotrophoblast and syncytiotrophoblast. No fetal elements were observed. The patient had a normal full-term spontaneous vaginal delivery 22 months after curettage and was free of disease without therapy at 32 months. This tumour provides evidence for an origin of choriocarcinoma from villous trophoblast. Our report illustrates the need to perform thorough microscopic examination of the products of conception, especially in the absence of a fetus or fetal parts.

Adult↗

PubMed1995

Yolk sac tumour of the ear.

We report the second known case of yolk sac tumour of the external auditory canal, occurring in an eight-month-old girl. The excised tumour demonstrated histopathological and immunohistochemical features identical to those of yolk sac tumours of gonadal origin. The tumour was aneuploid by flow cytometry. The patient received chemotherapy post-operatively and has had no evidence of disease 13 months after surgery.

Ear Canal↗

PubMed1995

The 24-hour rhythms in plasma growth hormone, prolactin and thyroid stimulating hormone: effect of sleep deprivation.

Twenty-four hour secretory rhythms of growth hormone (GH), prolactin (PRL) and thyroid stimulating hormone (TSH) were investigated in 9 normal adult men by means of serial blood sampling at 30 min intervals. The profiles of pituitary hormones were compared in 6 subjects between in normal nocturnal sleep condition and in delayed sleep condition. Plasma GH was measured with use of highly sensitive enzyme immunoassay (EIA) recently developed. Plasma TSH was also evaluated by highly sensitive time-resolved fluorometric immunoassay (TR-FIA). Time series analysis of plasma GH and PRL was performed by auto- and cross- correlation and spectral analysis. The detection limit of EIA for GH was 0.3 pg/ml and all plasma GH levels were within the detectable range of this EIA. Cross-correlation and spectral analysis suggested the presence of approximately 2-3 h rhythmicity of plasma GH. Plasma PRL appeared to have some 24-hour rhythmicity besides its sleep-dependent component. Sleep deprivation caused marked elevation of plasma TSH during night time. It is suggested that there appears two mechanisms regulating GH secretion: one has a sleep-independent and ultradian rhythm and another has a sleep-dependent rhythm.

Activity Cycles↗

PubMed1995

Solitary fibrous tumor of the nasal cavity and orbit.

Solitary fibrous tumors (SFT) are rare spindle cell neoplasms generally associated with the serosal surface, especially the pleura. Two SFT are reported arising in the nasal cavity and orbit, occurring in a 33 year old female and a 21 year old male, respectively. The lesions lacked the characteristic features of other recognized neoplasms that occur in these regions. Immunohistochemically, the tumors cells were diffusely and strongly positive for vimentin and CD34 and some or many tumor cells expressed neuron-specific enolase and Leu-7. Ultrastructurally, the tumor cells showed no distinct features although they were suggested to be primitive mesenchymal or fibroblast-like cells. Both tumors were diploid by flow cytometry. The two patients have had benign clinical courses with limited follow-up. Our findings suggest that SFT is of mesenchymal cell origin and support another location for SFT, indicating additional evidence against mesothelial origin. SFT should be included in the differential diagnosis of spindle cell tumors arising in the nasal cavity and orbit.

Adult↗

PubMed1995

Spindle cell hemangioendothelioma: an immunohistochemical and flow cytometric study of six cases.

Six cases of spindle cell hemangioendothelioma (SCH) are presented with immunohistochemical and flow cytometric analyses. One case was associated with Maffucci's syndrome. All lesions were solitary or multifocal in the extremities, and prepresentation duration ranged from years to decades. One case recurred but none had metastases. Histologically, in four of the six cases the main lesions appeared to arise within vessels, predominantly muscular vessels. All lesions consisted of cavernous hemangioma-like areas and solid cellular areas resembling Kaposi's sarcoma. Cellular atypia was minimal. At the periphery of the lesions, a cluster of large thick or thin walled, and probably malformed, vessels were observed. Immunohistochemically, factor-VIII related antigen, CD34, vimentin, and lectin binding Ulex europaeus agglutinin 1 stained endothelial cells lining vascular channels, and vacuolated, or epithelioid cells. Spindle cells in the solid areas were negative for these endothelial markers except for vimentin, but showed divergent positive immunoreactions of HHF35, alpha-smooth muscle actin, desmin, and collagen type IV. Five cases were diploid and one was aneuploid. There was no significant correlation among DNA ploidy, S-phase fraction, and local recurrence in SCH although the number of cases examined was small. These results suggest SCH may be a benign lesion, probably a reactive process, rather than a low-grade angiosarcoma.

Adult↗

PubMed1995

Measurement of human immunodeficiency virus type 1 p24 in serum by an ultrasensitive enzyme immunoassay, the two-site immune complex transfer enzyme immunoassay.

Human immunodeficiency virus type 1 (HIV-1) p24 antigen was measured by an ultrasensitive enzyme immunoassay (two-site immune complex transfer enzyme immunoassay). The antigen was reacted simultaneously with 2,4-dinitrophenyl-biotinyl-bovine serum albumin-anti-recombinant p24 (rp24) Fab' conjugate and anti-rp24 Fab'-beta-D-galactosidase conjugate. The complex that was formed, comprising the three components, was transferred from polystyrene beads coated with affinity-purified (anti-2,4-dinitrophenyl group) immunoglobulin G (IgG) to polystyrene beads coated with streptavidin. The detection limit of rp24 was 2.4 fg (0.1 amol) per assay or 0.24 pg/ml with as little as 10 microliters of serum. When sera were treated at low pH, p24 was detected in 34 (68%) of 50 serum samples from asymptomatic carriers, in 25 (86%) of 29 serum samples from patients with advanced HIV-1 infection, and in none of 117 serum samples from HIV-1-seronegative individuals. Levels of p24 in serum were inversely correlated to those of anti-HIV-1 p24 IgG, and the recovery of rp24 added to serum decreased to zero with increasing levels of anti-HIV-1 p24 IgG in serum. This sensitive method may be used as a powerful tool for investigating the disease.

Antigen-Antibody Complex↗

PubMed1995

Two novel mutations in the coding region for neurophysin-II associated with familial central diabetes insipidus.

Familial central diabetes insipidus is an autosomal dominant disease caused by a deficiency of arginine vasopressin (AVP). We previously reported three distinct mutations in the AVP gene in Japanese familial central diabetes insipidus pedigrees that result in a substitution of Ser for Gly57 in the neurophysin-II (NPII) moiety of the AVP precursor, a substitution of Thr for Ala at the COOH-terminus of the signal peptide, and a deletion of Glu47 in the NPII moiety. In this study, we analyzed the AVP gene in two pedigrees by direct sequencing of the polymerase chain reaction-amplified DNA and found two novel mutations in exon 2, which encodes the central part of the NPII moiety of the precursor. The mutation in one pedigree was a C to A transition at nucleotide position 1891, which replaces Cys67 (TGC) with stop codon (TGA). As the premature termination eliminates part of the COOH domain of the NPII moiety and the glycoprotein moiety, the conformation of the truncated protein is likely to be markedly different from that of normal precursor. In another pedigree, a G to T transversion was detected at nucleotide position 1874, which substitutes polar Trp (TGG) for hydrophobic Gly62 (GGG). It is possible that mutated NPII molecules, as a consequence of a conformational change, cannot bind AVP or self-associate to form higher oligomer complexes. Interestingly, all mutations we have identified to date, with the exception of the signal peptide mutation, are located in exon 2, suggesting the importance of the highly conserved central part of the NPII molecules and/or the NPII moiety in the precursor for AVP synthesis.

Adolescent↗

PubMed1995

Synthesis of 3-ureido derivatives of coumarin and 2-quinolone as potent acyl-CoA: cholesterol acyltransferase inhibitors.

Novel 3-ureido derivatives of 4-phenylcoumarin and 4-phenyl-2-quinolone were synthesized and evaluated for acyl-CoA: cholesterol acyltransferase (ACAT)-inhibitory activity. These derivatives inhibited rat intestinal ACAT with IC50 values at the 10(-8) to 10(-9) M level and were found to normalize plasma cholesterol levels in cholesterol-fed rats when administered as dietary admixtures.

Animals↗

PubMed1995

[Evaluation of the residual functional reserve and the early regeneration after the hepatic resection using asialoglycoprotein receptor imaging agent].

99mTc-DTPA-galactosyl human serum albumin (99mTc-GSA) is a newly developed liver imaging ligand which specifically binds to asialoglycoprotein receptor on the hepatic cell surface. We investigated whether 99mTc-GSA scintigraphy was able to be used as indexes for the residual functional reserve and the early regeneration of the hepatocyte after the hepatic resection. Four patients with metastatic liver cancer, 3 patients with hepatocellular carcinoma, and 1 patient with cholangiocellular carcinoma were studied. Basically, each patient was examined 4 times (before, 3, 10, 20 days after the operation). Immediately after i.v. injection of 185 MBq (3 mg) of 99mTc-GSA, serial images and dynamic data were obtained. Serial changes of HH15, as an index of blood clearance of the tracer calculated from the uptake ratio of heart at 15 minutes to that at 3 minutes, and LHL15, as an index of hepatic accumulation calculated from the uptake ratio of liver to liver plus heart at 15 minutes after the injection were analyzed before and after hepatectomy. Three out of 4 lobectomy patients which showed increased HH15, and decreased LHL15 as compared with the preoperative data were considered to be decreased residual hepatic functional reserve. The remaining one lobectomy patient showed increased HH15, but increased LHL15 inversely. One patient of two partial resections of hepatocellular carcinoma with liver cirrhosis demonstrated transiently decreased HH15, and increased LHL15. Two patients with metastatic liver cancer (one partial resection, six partial resections) showed decreased HH15, and increased LHL15. Postoperatively increased hepatic accumulation was presumed to be increased functioning hepatocyte or transiently increased asialoglycoprotein receptor on the cell surface by up-regulation. 99mTc-GSA scintigraphy might be helpful for non-invasive method to detect the residual functional reserve and the early regeneration of the hepatocyte after the hepatic resection.

Aged↗

PubMed1994

Conjugation of recombinant reverse transcriptase of HIV-1 to beta-D-galactosidase from Escherichia coli for ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) of anti-HIV-1 IgG.

Recombinant reverse transcriptase (RT) of HIV-1 was conjugated to beta-D-galactosidase from Escherichia coli in three different ways. Maleimide groups were introduced into beta-D-galactosidase molecules using N,N'-o-phenylenedimaleimide in the absence (method I) or presence (method II) of N-ethylmaleimide or into beta-D-galactosidase molecules, which had been treated with excess of 4,4'-dithiodipyridine to block thiol groups, using N-succinimidyl-6-maleimidohexanoate (method III). Subsequently, the maleimide groups were reacted with thiol groups introduced into recombinant RT molecules using N-succinimidyl-S-acetylmercaptoacetate. The conjugates were tested by a sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay). The immune complex consisting of 2,4-dinitrophenyl-bovine serum albumin-recombinant RT conjugate, anti-HIV-1 IgG and recombinant RT-beta-D-galactosidase conjugate was captured by polystyrene beads coated with (anti-2,4-dinitrophenyl group) IgG, eluted with N epsilon-2,4-dinitrophenyl-L-lysine and transferred to polystyrene beads with (anti-human IgG gamma chain) IgG. The conjugate prepared by method III, which showed the least polymerization, the least loss of the specific enzyme activity and the lowest nonspecific binding, improved the sensitivity of the enzyme immunoassay for anti-HIV-1 IgG approximately 30-fold compared with RT-horseradish peroxidase conjugate.

Animals↗