Antibody to human herpesvirus-6 (HHV-6) was measured in cord blood mononuclear cell cultures by a neutralization (NT) test, in which the presence or absence of characteristic large cell formation in cells infected with HHV-6 was used as an indicator for neutralization of the virus. The NT test could measure antibodies during and just after the appearance of the skin rash in patients with exanthem subitum. The levels of antibodies measured by the NT test was generally higher than that by an indirect immunofluorescence assay.

Antibodies, Viral↗

PubMed1990

Simultaneous infection with human herpesvirus-6 and measles virus in infants.

Two infants (4 and 5 months of age) with a febrile episode for 3 and 5 days, respectively, developed skin rashes after the fever subsided and were diagnosed as exanthem subitum. The rash continued for 5 days followed by mild-to-moderate pigmentation. Human herpesvirus-6 and measles virus, which were confirmed by a specific immunofluorescence assay and by electron microscopy, were isolated simultaneously from blood in the acute stage of the disease but not from the convalescent stage. The titer of the herpesvirus-6 in blood was greater than that of measles. Specific serologic assays showed marked seroconversion against human herpesvirus-6 but not to measles virus. The results suggest that dual infection with human herpesvirus-6 and measles virus results in atypical exanthem subitum or modified measles with unique immunologic responses.

Exanthema Subitum↗

PubMed1990

Enzyme-linked immunosorbent assay for detection of IgG antibody to human herpesvirus 6.

A lysate of human herpesvirus 6 (HHV-6)-infected cord blood mononuclear cells was used as antigen for enzyme-linked immunosorbent assay for the detection of IgG antibody to HHV-6. Antibody responses after exanthem subitum were well correlated with clinical recovery from the disease and the level of antibody activities was well correlated with indirect immunofluorescence assay and the neutralization test. Seroconversion to other human herpesvirus, including cytomegalovirus, was not observed in infants with exanthem subitum. All of the infants had by the age of 1 month antibodies to HHV-6, which decreased with age to the lowest level at the age of 3 to 6 months and then increased and reached the maximum level by 1 to 2 years of age. After 3 years of age, the prevalence was almost stable.

Adolescent↗

PubMed1990

In vivo measurement of intra- and extracellular space of brain tissue by electrical impedance method.

An impedance method was applied to evaluate transcellular fluid shifts in ischaemic brain oedema. The admittances (apparent electrical conductivities) of tissues were measured at varied frequencies based on a simple model of an electrical equivalent circuit for tissues, which consisted of Re (resistivity of extracellular fluid), Ri (resistivity of intracellular fluid) and Cm (capacitance of cell membrane). Calculated were Re, Ri, Rinf (resistivity of total fluid), Re/Ri and alpha (Cole-Cole distribution index) of brain tissue by Cole-Cole an arc of a circle. During ischaemia induced by cat middle cerebral artery occlusion (MCAO), the parameters were examined continuously. After MCAO, cerebral blood flow (CBF) decreased to under 10 ml/100 g/min. Then Re and Re/Ri increased, but Ri decreased. These results indicated that fluid shift from extracellular (EC) to intracellular (IC) space occurred after ischaemic insult. Rinf showed no changes during ischaemia of 30 min, which demonstrated no changes of total fluid volume. Using this impedance technique, fluid accumulation and shift may be examined by changes of Re, Ri, Re/Ri and Rinf in various types of brain oedema in vivo.

Animals↗

PubMed1990

Interpeduncular high-density spot in severe shearing injury.

Thirty cases of severe shearing injury were analyzed utilizing serial computed tomography scans and clinical observations. Fatalities occurred in the majority of patients whose Glasgow Coma Scale scores at admission were 6 or less. The presence of perimesencephalic subarachnoid hemorrhage, hemorrhage in the corpus callosum, acute brain swelling, and intraventricular hemorrhage on computed tomography scans resulted in high mortality rates. In 13 patients, interpeduncular high-density spots were observed on computed tomography scans, which were performed in the acute stage of injury. Eight of these patients died, and those surviving had poorer neurological outcomes than corresponding patients with identical Glasgow Coma Scale scores on admission. In the management of severe shearing injury patients, more attention should be given to the presence of interpeduncular high-density spots as well as other important diagnostic computed tomography findings regarding diffuse brain injury.

Adolescent↗

PubMed1990

Severity of viremia and clinical findings in children with varicella.

The number of varicella zoster virus-infected mononuclear cells in blood samples obtained during 3 days before appearance of vesicular skin rashes could be estimated in 13 of 21 immunocompetent children with varicella and viremia (range, 1-83 per 10(7) mononuclear cells). The virus was isolated from 5% of adherent cells (1/21), 71% of nonadherent cells (12/17), 43% of T lymphocytes (9/21), and 33% of B lymphocytes (7/21). The number of vesicles on the body correlated with the maximum body temperature, duration of fever, and number of infected cells in the blood. These results indicate that varicella zoster virus infection in immunocompetent children is disseminated by circulating T and B lymphocytes and the severity of the viremia is reflected in the severity of the disease.

B-Lymphocytes↗

PubMed1990

Neutralizing antibodies to human herpesvirus-6 in healthy individuals.

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Adult↗

PubMed1990

Application of monoclonal antibodies for endothelin to hypertensive research.

We developed six kinds of monoclonal antibodies against endothelin (ET)-1 recognizing different epitopes with high affinities (5 x 10(10) M-1 to 5 x 10(11) M-1). Using these monoclonal antibodies, we developed radioimmunoassays for ET-1 with different specificities. Cross-reactivities with ET-2 ranged from 80% to 100%, and those with ET-3 ranged from 3% to 60%. Patients with essential hypertension (n = 20) showed a significant elevation in the plasma ET-1-LI level compared with age-matched control subjects (n = 12) (30.1 +/- 1.4 pg/ml versus 18.5 +/- 0.9 pg/ml, p less than 0.01). The plasma ET-1-LI level in hypertensive patients in stages II and III (World Health Organization classification) was significantly higher than that in those patients in stage I. There was no significant correlation between the plasma ET-1-LI level and systolic blood pressure (r = 0.11), diastolic blood pressure (r = -0.13), or age (r = 0.24) in all patients studied who had essential hypertension. In the neutralization experiment, monoclonal antibodies attenuated ET-1-induced contraction of rat aortic rings and the pressor action of ET-1 in pithed rats in vivo. The present study demonstrates the elevated plasma ET-1-LI level in patients with essential hypertension. Monoclonal antibodies developed in this study can become powerful tools to investigate the pathophysiological significance of ET in essential hypertension.

Animals↗

PubMed1990

Rat brain natriuretic peptide. Isolation from rat heart and tissue distribution.

We have isolated a cardiac natriuretic peptide of 5,000 d from atrial tissues from 500 rats and determined its amino acid sequence. The 5,000 d atrial natriuretic factor was elucidated to be a 45 amino acid peptide with the sequence of S-Q-D-S-A-F-R-I-Q-E-R-L-R-N-S-K-M- A-H-S-S-S-C-F-G-Q-K-I-D-R-I-G-A-V-S-R-L-G-C-D-G-L-R-L-F by sequencing the native peptide and its lysyl endopeptidase digests. The sequence of this peptide was identical to the amino acid sequence (51-95) of the rat brain natriuretic peptide precursor deduced from the complementary DNA (cDNA) sequence. The cardiac natriuretic peptide with a molecular weight of 5,000, or rat brain natriuretic peptide, was identified as the major storage form and as the sole secretory form derived from the brain natriuretic peptide precursor in the rat heart. The rat brain natriuretic peptide level in the atrium was 3.68 +/- 0.61 micrograms/g, which represents about 4% of that of atrial natriuretic factor. Rat brain natriuretic peptide was also detected in the ventricle. The ratio of brain natriuretic peptide to atrial natriuretic peptide in the ventricle was approximately 30% and much higher than that in the atrium. Rat brain natriuretic peptide, however, was not detectable in the brain. We conclude that the 5,000 d cardiac natriuretic peptide is rat brain natriuretic peptide with 45 amino acids derived from the brain natriuretic peptide precursor and is secreted from the rat heart as a novel cardiac hormone.

Amino Acid Sequence↗

PubMed1990

Rat brain natriuretic peptide--tissue distribution and molecular form.

Using an antiserum against the ring structure of rat brain natriuretic peptide (rat BNP), we have established a specific radioimmunoassay (RIA) for rat BNP and elucidated its tissue distribution and molecular form. Rat BNP-like immunoreactivity (-LI) was detected in the highest amount in cardiac extracts (574.0 +/- 138.8 pmol/g in the atrium and 4.3 +/- 1.1 pmol/g in the ventricle). The secretory rate of rat BNP-LI from the perfused whole heart was 50.0 +/- 1.9 fmol/min, about 60% of which was maintained even after atrial removal. We also detected rat BNP-LI throughout the spinal cord (134-175 fmol/g), although no detectable amount was present (less than 100 fmol/g) in other tissues including the brain. High performance-gel permeation chromatography and reverse phase-high performance liquid chromatography coupled with the RIA revealed that rat BNP with 45 amino acids is a major storage form as well as a secretory form of rat BNP-LI in the heart. The major component in the spinal cord was also rat BNP. These findings indicate that the tissue distribution and the processing pattern of rat BNP are different from those of atrial natriuretic peptide and porcine BNP, thereby suggesting the presence of complicated diversity of the natriuretic peptide system.

Animals↗

PubMed1990

Preparation of monoclonal antibodies against brain natriuretic peptide and their application to radioimmunoassay and passive immunization.

Two monoclonal antibodies (mAbs) directed toward brain natriuretic peptide (BNP), KY-BNP-I and KY-BNP-II, have been produced. Both mAbs against BNP possessed high affinities for BNP, with association constants (Ka) of 4.0 X 10(9) M-1 (KY-BNP-I) and 2.0 X 10(10) M-1 (KY-BNP-II). With these mAbs, specific RIAs for BNP have been established. The least detectable quantities of BNP were 5 pg/tube (KY-BNP-I) and 1 pg/tube (KY-BNP-II). Cross-reactivities of alpha-human and rat atrial natriuretic polypeptides were less than 0.001%. These RIAs detected BNP-like immunoreactivity (BNP-LI) not only in the porcine brain but also in the canine brain, with the highest concentration in the medulla oblongata. These RIAs also detected BNP-LI in both the porcine and canine hearts and in the porcine plasma. The iv pretreatment of purified mAb[KY-BNP-II] almost completely blocked the hypotensive action of iv administered BNP in rats, with the concomitant suppression of BNP-induced increase of the plasma cyclic GMP level. These results indicate that our mAbs against BNP will serve as a useful tool for the elucidation of the physiological and pathophysiological significance of BNP as a neuropeptide and as a hormone.

Animals↗

PubMed1990

Antiscorbutic activity of L-ascorbic acid 2-glucoside and its availability as a vitamin C supplement in normal rats and guinea pigs.

Bioavailability of a newly-synthesized and chemically-stable 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) as a vitamin C supplement was investigated in rats and guinea pigs. Oral administration of AA-2G to the animals resulted in an increase of serum ascorbic acid (AA) levels. However, in these sera the intact form was not detectable by the high performance liquid chromatography (HPLC) method, indicating its hydrolysis through the process of absorption. After an intravenous injection of AA-2G, the intact form diminished rapidly from the serum, followed by prolonged and marked elevation of serum AA levels. Various tissue homogenates from rats and guinea pigs were examined for their releasing activity of AA from AA-2G. High activity was observed in kidney, small intestine and serum of rats and in small intestine and kidney of guinea pigs. These hydrolytic activities were completely inhibited by castanospermine, a specific alpha-glucosidase inhibitor, suggesting the participation of alpha-glucosidase in the in vivo hydrolysis of AA-2G. AA-2G was found to exhibit obvious therapeutic effect in scorbutic guinea pigs by its repeated oral administrations. These results indicate that AA-2G is a readily available source of vitamin C activity in vivo.

Administration, Oral↗

PubMed1990

L-ascorbic acid alpha-glucoside formed by regioselective transglucosylation with rat intestinal and rice seed alpha-glucosidases: its improved stability and structure determination.

The definite structure and chemical stability of a new glucoside of L-ascorbic acid (AA) which was enzymatically glucosylated with rat intestinal and rice seed alpha-glucosidases were reported. The stability of this AA derivative in water under aerobic conditions was proved by its remarkable resistance against enhanced oxidative degradation by heat, Cu2+ ion or ascorbate oxidase, and it was found to have no reducing activity toward radicals. These properties were obviously distinguishable from those of AA. This glucoside was effectively hydrolyzed by alpha-glucosidases which possessed the ability to synthesize itself, resulting in the liberation of AA activity. The conjugate was composed of equimoles of AA and glucose. Nuclear magnetic resonance spectra, mass spectra, pH profiles of ultraviolet spectra and pK(a) value of 3.10 supported the coupling of alpha-glucose to the 2-position of AA. From these results, its structure was assigned 2-O-alpha-D-glucopyranosyl-L-ascorbic acid, being distinct from 6-O-alpha-D-glucopyranosyl-L-ascorbic acid formed with Aspergillus niger alpha-glucosidase. These findings indicate that the 2-O-glucoside formed by regioselective transglucosylation withstands oxidative degradation even in aqueous solutions and it can be used as an available active AA source for multicomponent liquid products.

Animals↗

PubMed1990

[Treatment of nausea and vomiting induced by a 24-hour i.v. infusion of cisplatin].

Nine advanced gastric cancer patients were given 17 courses of cisplatin administrations by means of a 24-hour intravenous infusion at a dose of 100 mg/m2. For an anti-emetic, 40 mg of metoclopramide was administered 5 times at 6-hour intervals, along with a 500 mg hydrocortisone administration at the start of the cisplatin infusion. Despite this preventative treatment, nausea and/or vomiting occurred in over one-third of all the courses. Thus, to combat this nausea and/or vomiting, a combination of lorazepam (1.5 mg/day, divided into 3 p.o.), dexamethasone (20, 10 and 10 mg by i.v. at 3, 8, and 24 hours, respectively, after start of the cisplatin infusion), and a 60 mg intravenous administration of metoclopramide (5 times at 6-hour intervals) was given, and it was found that this new method (Method IV) prevented both nausea and vomiting.

Antineoplastic Combined Chemotherapy Protocols↗