Search PubMed⌕ Search

Biomedical subjects

K Horiuchi

Publications and source records attributed to K Horiuchi.

At least 181 records · Page 10Linked to original sources
PubMed1988

Improved regional and global diastolic performance in patients with coronary artery disease after percutaneous transluminal coronary angioplasty.

To investigate the improvement of left ventricular (LV) function after successful percutaneous transluminal coronary angioplasty (PTCA), we studied resting ejection fraction, regional ejection fraction, filling fraction as an index of early diastolic performance, and regional filling fraction in 22 patients with single-vessel coronary artery disease and technically adequate LV angiograms before and 6 months after successful PTCA without restenosis. Before PTCA, filling fraction was significantly less in patients with coronary artery disease than in the control group, although there was no significant difference in ejection fraction. Filling fraction improved significantly after PTCA. Regional filling fraction increased significantly in jeopardizing myocardium, but regional filling fraction in nonjeopardized myocardium did not change significantly. Ejection fraction and regional ejection fraction did not change significantly after PTCA. Our results indicate that the improvement of regional diastolic performance in jeopardized myocardium may contribute to the improvement of global diastolic performance after successful PTCA.

Adult↗
PubMed1988

Role of coronary collateral vessels during transient coronary occlusion during angioplasty assessed by hemodynamic, electrocardiographic and metabolic changes.

The clinical role of collateral vessels was evaluated during transient coronary occlusion by percutaneous transluminal coronary angioplasty in 22 patients with (8) and without (14) collateral vessels. Coronary occlusion pressure, the ratio of mean coronary occlusion pressure to mean aortic pressure and myocardial perfusion pressure at 40 s of balloon inflation were significantly higher in patients with than in patients without collateral vessels. The changes in left ventricular systolic and end-diastolic pressure, maximal rate of rise of left ventricular pressure (peak dP/dt) and maximal rate of fall of left ventricular pressure (negative peak dP/dt) during balloon inflation were less in patients with than in patients without collateral vessels. Myocardial lactate was produced in patients without collateral vessels but not in those with such vessels. Marked ST segment elevation in the electrocardiogram occurred in patients without collateral vessels but either ST segment depression or mild ST segment elevation was observed in patients with collateral vessels. This study indicates that collateral vessels limit myocardial ischemia during coronary occlusion, probably as a result of increased myocardial perfusion pressure.

Adult↗
PubMed1988

Integration host factor interacts with the DNA replication enhancer of filamentous phage f1.

We present data which show that the Escherichia coli integration host factor (IHF) is an activator of phage f1 DNA replication. Phage f1 poorly infects bacterial strains lacking IHF because IHF is required for efficient expression of F-pili, the receptor for f1 phage. However, when F- strains are transfected with f1 DNA the phage replicates in IHF mutants (himA, himD, or himA himD) at a rate of only 3% of that in wild-type bacteria. A plasmid dependent on the f1 replicon fails to transform IHF mutants. By gel retardation analysis, we show that IHF specifically binds to the origin of replication. DNase I "footprinting" experiments demonstrate that IHF binds to multiple sites within the replication enhancer sequence, a cis-acting, A + T-rich sequence that potentiates f1 DNA replication. Moreover, the effect of IHF mutation on f1 growth is suppressed by initiator protein (f1 gene II) mutations that restore efficient replication from origins that lack a functional replication enhancer sequence. This genetic evidence supports the conclusion that the replication enhancer sequence is the site of action of IHF.

Bacterial Proteins↗
PubMed1988

Clinical evaluation of tumour imaging using 99Tc(V)m dimercaptosuccinic acid, a new tumour-seeking agent.

Considering the favourable nuclear properties of 99Tcm over 67Ga, we have developed a new tumour-seeking agent, 99Tc(V)m dimercaptosuccinic acid (Tc(V)-DMSA). In order to evaluate the clinical usefulness of Tc(V)-DMSA scintigraphies, 492 patients were studied with Tc(V)-DMSA, and in some cases, where possible, the results were compared with conventional 67Ga citrate scintigraphies. There was a high degree of usefulness of Tc(V)-DMSA in patients with head and neck tumours, medullary thyroid carcinomas and soft tissue tumours. But in patients with carcinomas of the lung, liver and gastrointestinal tract, malignant melanoma and lymphoma, Tc(V)-DMSA was of no or little use.

Drug Evaluation↗
PubMed1988

Japanese clinical trials with Takeda acellular pertussis vaccine.

Japanese clinical trials with Takeda acellular pertussis vaccine revealed that infants 3 to 8 months of age reacted sufficiently to the vaccine: anti-PT ant-FHA levels after vaccination were as high as those observed with 2 year old children. No substantial difference in general reactions was noted between infants and 2 year old children. Less local reactions were noted in infants.

Age Factors↗
PubMed1988

The effect of deoxygenation rate on the formation of irreversibly sickled cells.

The effects of the deoxygenation rate on the formation of irreversibly sickled cells (ISCs) were investigated by using metabolically replete sickle cells (SS cells). We found that the formation of ISCs required Ca2+ and that the amount formed depended on the rate of deoxygenation. When less dense SS discocytes were deoxygenated slowly by flushing with 95% N2 and 5% CO2 at a rate of 3 mL/min, the percentage of ISCs increased from 5% to 26.5% after 24 hours. In contrast, upon rapid deoxygenation (10, 35 mL/min) ISC formation was reduced significantly. The difference may be related to fact that more sickle-shaped cells were formed upon slow deoxygenation than upon the rapid deoxygenation that resulted in the formation of star-shaped and granulated cells. So-called ISCs were formed more easily from sickle-shaped cells. To express the shape of sickled cells numerically, we calculated the mean maximum cell length (MCL) after cells were incubated under various deoxygenation conditions. The MCL of slowly deoxygenated SS cells after 24 hours of incubation was about twice (20.0 +/- 7.0 micron) that of quickly deoxygenated (35 mL/min) SS cells (12.5 +/- 5.0 microns) (initial MCL, 8.0 +/- 1.0 micron). The decrease in potassium content was greater with slow deoxygenation than with rapid deoxygenation. Because the increase in sodium influx was less than that of potassium efflux under slow deoxygenation, SS cells became more dense than those rapidly deoxygenated. In the absence of Ca2+, morphological changes were the same as in the presence of Ca2+; however, under this condition there was no change in density, and no ISCs were formed regardless of the rate of deoxygenation. These results demonstrate that the number of ISCs formed correlates with the MCL. The length of fibers of sickle hemoglobin may be a determinant of the length of sickled cells. This suggests that membrane stretching plays an important role in cell density and irreversible membrane deformation.

Anemia, Sickle Cell↗
PubMed1987

Radioiodinated 2'-iodospiperone: a new radioligand for in vivo dopamine receptor study.

In vivo dopamine receptor binding of the newly synthesized ligand, 125I-2'-iodospiperone (125I-2'-ISP), was studied in mouse brain. The highest accumulation was found in the striatum. Analysis of the striatal homogenate showed the 125I-2'-ISP to be metabolically stable. Furthermore, this striatal binding was saturable and displaced only by dopaminergic drugs. On the other hand, the accumulation in the cortex was as low as that of the cerebellum and uneffected by the administration of serotoninergic drugs and dopaminergic drugs; results assessed by macroautoradiographic studies. Thus, the newly synthesized 125I-2'-ISP presented high affinity for dopamine receptors in vivo and therefore, holds great potential for the in vivo dopamine receptor studies, provided 123I becomes readily available.

Animals↗
PubMed1987

Interaction between the replication origin and the initiator protein of the filamentous phage f1. Binding occurs in two steps.

The replication initiator protein of bacteriophage f1 (gene II protein) binds to the phage origin and forms two complexes that are separable by polyacrylamide gel electrophoresis. Complex I is formed at low gene II protein concentrations, and shows protection from DNase I of about 25 base-pairs (from position +2 to +28 relative to the nicking site) at the center of the minimal origin sequence. Complex II is produced at higher concentrations of the protein, and has about 40 base-pairs (from -7 to +33) protected. On the basis of gel mobility, complex II appears to contain twice the amount of gene II protein as does complex I. The 40 base-pair sequence protected in complex II corresponds to the minimal origin sequence as determined by in-vivo analyses. The central 15 base-pair sequence (from +6 to +20) of the minimal origin consists of two repeats in inverted orientation. This sequence, when cloned into a plasmid, can form complex I, but not complex II. We call this 15 base-pair element the core binding sequence for gene II protein. Methylation interference with the formation of complex I by the wild-type origin indicates that gene II protein contacts six guanine residues located in a symmetric configuration within the core binding sequence. Formation of complex II requires, in addition to the core binding sequence, the adjacent ten base-pair sequence on the right containing a third homologous repeat. A methylation interference experiment performed on complex II indicates that gene II protein interacts homologously with the three repeats. In complex II, gene II protein protects from DNase I digestion not only ten base-pairs on the right but also ten base-pairs on the left of the sequence that is protected in complex I. Footprint analyses of various deletion mutants indicate that the left-most ten base-pairs are protected regardless of their sequence. The site of nicking by gene II protein is located within this region. A model is presented for the binding reaction involving both protein-DNA and protein-protein interactions.

Base Sequence↗
PubMed1987

Procurement of radioiodinated glucose derivative and its biological character.

Radiolabeled glucose derivatives are attracting great interest in the clinical field. Development of an analogous substrate labeled with a practical radionuclide, 123I, is most desirable, however, no radioiodine labeled glucose derivative has been reported as being chemically and biologically compatible. Thus, in the present study, a glucose derivative substituted at the C-2 position by a p-iodobenzyl group, a 2-O-(p-iodobenzyl)-D-glucose (IBG) was designed and its synthesis was carried out. A very easy and simple synthetic method was developed, and the obtained IBG showed appropriate purity and stability for its radioiodination. [125I]IBG was obtained by radioisotopic exchange reaction with high radiochemical purity and radiochemical yield, requiring no purification. The good in vivo and in vitro stability and the chemical and biological characteristic displayed by the new [125I]IBG stimulated the measurement of the brain uptake index (BUI). In the presence of glucose, brain uptake inhibition was detected, a good indication of a glucose carrier mediator for the transport of [125I]IBG through the blood-brain barrier, a similar feature to that of [14C]glucose or 3-O-[14C]methylglucose. The newly designed ligand IBG holds good promise for the study of regional cerebral glucose utilization, should the 123I become available.

Animals↗
PubMed1987

Detection of the cross-linking amino acid, histidinoalanine, in human brown cataractous lens protein.

In human nuclear cataract, with its progression, high polymers protein mass, which is aggregated and strengthened by disulfide cross-links and other covalent cross-links, accumulates in the nuclear region to cause hardening of the lens nucleus. However, the structure of non-disulfide covalent cross-links has not been clearly confirmed yet. Recently a cross-linking amino acid, histidinoalanine, was discovered in connective tissue and is thought to cause hardening of the tissue with aging. The content of this amino acid in the lens nucleus was studied. Nuclear cataract was classified on the basis of nuclear color as described by Pirie (1986). The content of histidinoalanine was found to be 0.05 +/- 0.03 nmol mg-1 in normal nucleus; 0.06 +/- 0.03 nmol mg-1 in grade I (uniform pale yellow); 0.05 +/- 0.03 nmol mg-1 in grade II (deep yellow nucleus); 0.38 +/- 0.07 nmol mg-1 (P less than 0.01) in grade III (hazel-brown nucleus) and 3.35 +/- 2.76 nmol mg-1 (P less than 0.01) in grade IV (deep brown nucleus). The result suggests that histidinoalanine is one of the non-disulfide cross-links of lens proteins in nuclear cataract and is closely related to the grade of cataract.

Adult↗
PubMed1987

Cornelia de Lange syndrome with cleft palate.

4 cases of Cornelia de Lange syndrome with cleft palate are presented. All cases had the characteristic features of this syndrome. As to oral manifestations, high arches were noted in 2 cases, cleft of hard and soft palate in 1 case, submucous cleft palate in 2 cases. As the others abnormalities, partial anodontia and microdontia were presented. In this report, characteristic features of these 4 cases with referential literature are described.

Abnormalities, Multiple↗