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Biomedical subjects

Y Yoshioka

Publications and source records attributed to Y Yoshioka.

At least 109 records · Page 6Linked to original sources
PubMed1990

Bilaterally persistent sciatic arteries.

A very rare developmental anomaly showing bilaterally persistent sciatic arteries was found in a cadaver of 89 year old female. Both right and left sciatic arteries arose from the internal iliac arteries and appeared between the piriformis and superior gemellus muscles at the buttock, being about 10 mm in diameter. Each artery, which accompanied by the companion vein, i.e. sciatic vein, sent the branches to the gluteus maximus and the flexor muscles of thigh. On the other hand, the femoral arteries of both lower limbs were smaller than usual, measuring 4.7 mm in left and 5.2 mm in right. The terminal vessels of those were joined to the sciatic arteries at the popliteal fossa. In addition, the present case also had another developmental anomaly, i.e. superficial brachial artery in the right upper limb.

Aged↗
PubMed1990

[The method of fixation of intra-aortic balloon catheter in the iliac artery without sheath introducer].

This paper showed the procedure of fixation of intra-aortic balloon without sheath. For this purpose, we found to use Implantaid Lead Introducer (peel away type). This introducer can be removed from balloon catheter after insertion into iliac artery. Consequently, the incidence of thromboembolism of iliac artery and complications such as myonephropathic metabolic syndrome may be decreased.

Humans↗
PubMed1989

The position of the disulfide bonds in human plasma alpha 2 HS-glycoprotein and the repeating double disulfide bonds in the domain structure.

The positions of the inter- and intra-chain disulfide bonds of human plasma alpha 2 HS-glycoprotein were determined. alpha 2 HS-glycoprotein was digested with acid proteinase and then with thermolysin. The disulfide bonds containing peptides were separated by reversed-phase HPLC and detected by SBD-F (7-fluorobenzo-2-oxa-1,3-diasole-4-sulfonic acid ammonium salt) method. One inter-disulfide bond containing peptide and five intra-disulfide bond containing peptides (A-chain) were purified and identified as Cys-18 (B-chain)--Cys-14 (A-chain), Cys-71--Cys-82, Cys-96--Cys-114, Cys-128--Cys-131, Cys-190--Cys-201 and Cys-212--Cys-229, respectively. The location of the intra-disulfide bonds revealed that the A-chain of alpha 2 HS-glycoprotein is composed of three domains. Two domains were shown to possess intramolecular homology judging from the total chain length of the domains, size of the loops formed by the S--S bonds, the location of two disulfide loops near the C-terminal end of domains A and B, the distance between two S--S bonds of each domain, the amino acid sequence homology between these two domains (22.6%), number of amino acid residues between the second S--S loops and the end of domains A and B, and the positions of the ordered structures.

Amino Acid Sequence↗
PubMed1989

Tibial anatomy and functional axes.

Articular geometry of the tibia has been studied in relation to the functional axis and extra-articular bone landmarks, using a Cartesian coordinate system. Thirty-one cadaver limbs were used, 26 of them paired. The donor age range was 61 to 89 years (17 females, 14 males), none of whom showed evidence of significant arthritic deterioration. Most linear parameters were greater in males than females (p less than 0.005), and correlations between these parameters were noted, e.g., tibial length versus plateau width (r = 0.7, p less than 0.01) with both genders combined. Gender differences occurred in only two of the angular parameters--tibial torsion (p less than 0.025) and foot rotation (p less than 0.005). For the latter, mean rotation was internal (-5 degrees) for males, and external (11 degrees) for females. No correlations between angular parameters were found. In the paired limbs, there was asymmetrical distribution of just two parameters--varus tilt of the tibial plateau margins (p less than 0.005) and lateral deviation of the tuberosity (p less than 0.025). The data complement a previous report on the femur. These studies are relevant to the kinematics of the lower limb, design and sizing of resurfacing components, and possibly to the pathogenesis of osteoarthritis.

Aged↗
PubMed1989

Alignment of the first metatarsal-phalangeal joint: important criteria for a new joint replacement.

Joint replacement is one of many options for the treatment of the first metatarsophalangeal (MTP) joint. Studies of the geometry of that joint have shown that it consists of two distinct articulations, the metatarsophalangeal and the MT-sesamoidal. Both are important, but the MT-sesamoidal tolerates only small deviations from an ideal alignment. The aim of this study was to investigate the alignment of the first MTP joint of a potential patient population, in order to design an optimal surface replacement. One measurement, the extension angle between the MT and the proximal phalanx was found to be the most important alignment criterion for the successful design of an implant and the necessary instruments. This angle controls the delicate interplay between the metatarsal head and the sesamoids and tolerates only small deviations from the normal range before the chance of sesamoidal subluxation increases significantly. The pre-operative knowledge of this and other alignment criteria is important for the ideal placement of an anatomical implant.

Humans↗
PubMed1989

Platelet activating factor antagonists: synthesis and structure-activity studies of novel PAF analogues modified in the phosphorylcholine moiety.

New analogues of platelet activating factor (PAF), in which the phosphate and trimethylammonium moieties were replaced with an acylcarbamoyl moiety and a quaternary cyclic ammonium group, were synthesized. Their biological activities as PAF antagonists were evaluated by the inhibition of PAF-induced rabbit platelet aggregation in vitro and protective effects on PAF-induced hypotension in rats and PAF-induced death in mice. Investigation of structure-activity relationships revealed that PAF antagonist activity is strongly influenced by the acyl substituent of the nitrogen atom on the carbamoyl group and the nature of the polar head group at the 3-position of the glycerin backbone. Among the compounds tested, 2-[[N-acetyl-N-[[2-methoxy-3-[ (octadecylcarbamoyl)oxy]propoxy]-carbonyl]amino] methyl]-1-ethylpyridinium chloride (21, CV-6209) was one of the most potent compounds in the in vitro assay (IC50 = 7.5 X 10(-8) M) and the most potent and long-lasting in the in vivo assays. (R)-(-)-21 and (S)-(+)-21 were also synthesized, and no significant differences were observed in PAF antagonist activity in vitro and an inhibitory effect on PAF induced hypotension in vivo between (RS)-21 and its enantiomers.

Animals↗
PubMed1989

Automated exchange transfusion and exchange rate.

An automated blood exchange transfusion (BET) with a two-site technique has been devised by Goldmann et al and by us, using an infusion pump. With this method, we successfully performed exchange transfusions 189 times in the past four years on 110 infants with birth weights ranging from 530 g to 4,000 g. The exchange rate by the automated method was compared with the rate by Diamond's method. Serum bilirubin (SB) levels before and after BET and the maximal SB rebound within 24 hours after BET were: 21.6 +/- 2.4, 11.5 +/- 2.2, and 15.0 +/- 1.5 mg/dl in the automated method, and 22.0 +/- 2.9, 11.2 +/- 2.5, and 17.7 +/- 3.2 mg/dl in Diamond's method, respectively. The result showed that the maximal rebound of the SB level within 24 hours after BET was significantly lower in the automated method than in Diamond's method (p less than 0.01), though SB levels before and after BET were not significantly different between the two methods. The exchange rate was also measured by means of staining the fetal red cells (F cells) both in the automated method and in Diamond's method, and comparing them. The exchange rate of F cells in Diamond's method went down along the theoretical exchange curve proposed by Diamond, while the rate in the automated method was significantly better than in Diamond's, especially in the early stage of BET (p less than 0.01). We believe that the use of this automated method may give better results than Diamond's method in the rate of exchange, because this method is performed with a two-site technique using a peripheral artery and vein.

Bilirubin↗
PubMed1988

Geometry of the first metatarsophalangeal joint.

This study aimed to define the articular geometry of the metatarsophalangeal (MTP) joint of the great toe. Embedded in resin blocks, five pairs of cadaveric first MTP joints (all from men) were sequentially cut in the sagittal plane with a milling machine, removing 0.5 mm of bone in each cut. The photographed cartilaginous outline of each cut was digitized against reference markers, which enabled a computer system to superimpose each outline in three dimensions. The intersesamoidal ridge was found to be parallel to the lateral shaft. The peak of the ridge was just lateral to the midline of the MT head. The articular outline, through the ridge of each sample, was circular; however, other surface contours were noncircular. The undulating plantar aspect of the MTP head formed by the intersesamoidal ridge and related grooves was found to have symmetric relationships to the sesamoid bones and a consistent orientation to the shaft. The rounded distal dorsal aspect of the MTP head showed consistent differences to the concavity formed by the phalangeal base. The sample size is too small for the sizing of prostheses but it is adequate to study the geometry of the MTP joint. More data are needed for the accurate replication of a resurfacing prosthesis and understanding of joint kinematics.

Cartilage, Articular↗
PubMed1988

Difference in growth behavior of human, swine, equine, and avian influenza viruses at a high temperature.

Growth characteristics of a wide range of influenza A viruses from different mammals and bird species were examined in an established line of canine kidney (MDCK) cells at an ordinary (37 degrees C) and a high temperature (42 degrees C). Although all viruses employed in the present study possessed a capability of replicating at 37 degrees C, virus growth at 42 degrees C showed considerable variation and reflected differences in the natural hosts of the isolates. All reference strains and isolates from bird species grew well in the MDCK cells maintained at 42 degrees C, but human viruses did not, showing an asymmetrical growth behavior. In contrast to this, growth of swine and equine viruses showed growth characteristics intermediate between human and avian viruses. Of the two swine viruses examined, replication of one strain occurred equally well at both temperatures and another failed to grow at 42 degrees C. Similarly, two of the three equine viruses tested belonging to H3N8 antigenic subtypes grew at 42 degrees C. However, the results obtained from comparison of plaque sizes and growth curves indicated that the replication of the above swine and equine viruses was restricted under a stringent temperature when compared to avian viruses. The detailed analysis of cloned viruses revealed that some of the swine and equine viruses contained two variants which are readily distinguished by growth behavior at 42 degrees C. Genome analysis of parental and virus clones by oligonucleotide mapping and migration profiles of RNA segments did not detect any differences among the above variants exhibiting the asymmetrical growth characteristics at 42 degrees C.

Animals↗
PubMed1988

The moment of intraventricular hemorrhage.

A continuous monitoring of the germinal layer by linear scanning ultrasound has been proposed for the purpose of ascertaining the moment of intraventricular hemorrhage (IVH). Using a VHS videotape, we performed the 48 hours monitoring in 7 immature infants weighing less than 1,000 g who required respiratory support. Four cases of these developed IVH. In one case, which was 755 g in birth weight and 24 weeks in gestational age, the moment of IVH was successfully demonstrated on the ultrasonic monitor. At that moment, there were no significant changes in heart rate and systemic blood pressure. No direct manipulation or treatment, such as an endotracheal suctioning or a heel puncture which might induce a blood pressure fluctuation, was being given at the moment of IVH. About 15 minutes after the episode, abnormal seizure-like movement periodically developed.

Blood Pressure↗
PubMed1988

Identification and characterization of the products from the traJ and traY genes of plasmid R100.

The nucleotide sequence of part of the tra region of R100 including traJ and traY was determined, and the products of several tra genes were identified. The nucleotide sequence of traJ, encoding a protein of 223 amino acids, showed poor homology with the corresponding segments of other plasmids related to R100, but the deduced amino acid sequences showed low but significant homology. The first four amino acids at the N-terminal region of the TraJ protein were not essential for positive regulation of expression of traY, the first gene of the traYZ operon. The nucleotide sequence of traY shows that this gene may use TTG as the initiation codon and that it encodes a protein of 75 amino acids. Analysis of the traY gene product, which was obtained as the fusion protein with beta-galactosidase, showed that the N-terminal region of the product has an amino acid sequence identical to that deduced from the assigned frame but lacks formylmethionine. traY of plasmid F, which encodes a larger protein than the TraY protein of R100, is thought to use ATG as an initiation codon. However, a TTG initiation codon was found in the preceding region of the previously assigned traY coding frame of F. Interestingly, when translation of traY of F was initiated from TTG, the amino acid sequence homologous to the TraY protein of R100 appeared in tandem in the TraY protein of F. This may suggest that traY of F has undergone duplication of a gene like the traY gene of R100.

Amino Acid Sequence↗
PubMed1987

Femoral anteversion: assessment based on function axes.

This study describes a clinically oriented anatomical assessment of anteversion on 32 cadavers ranging from 61 to 89 years. The method used a three-dimensional reference system based on functional axes of the femur. Each soft tissue-free femur was mounted on an osteometric table and aligned to its functional axes. The long axes were defined as passing from the centre of the femoral head to the femoral attachment of the posterior cruciate ligament (PCL). A line that ran through the PCL attachment (equal distal origin of this system) and was parallel to a transepicondylar line served as transverse axis. Anteversion of the femur was defined as an angle formed to the transverse axis by a line running through the centre of the femoral head through the midpoint of the narrowest segment of the femoral neck. The measurement mean for anteversion among these specimens was 7.4 degrees with a range from -10.8 degrees (retroversion) to 22.1 degrees. There was no statistical difference in mean values (p less than 0.05) between sexes or between right and left sides of the group; however, there were large variations for anteversions when each side in the same individual was compared (although there was no dominant side). Retroversions were observed in four of 32 femurs (12.5%). No correlation was found between the anteversion in these femurs and rotational geometry at the knee. We compared our data with those obtained by conventional techniques, by which anteversion for each femur was measured after the bone had been placed on a flat surface.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1987

Autoimmunity and chondrolysis of the hip. A report of two cases.

Two patients with rapidly progressive chondrolysis of the hip are reported. Immunofluorescent staining showed deposits of immunoglobulins and complement components in the synovium and the remaining femoral head cartilage. Seven patients with osteoarthritis of the hip and knee, or femoral neck fractures, were used as controls and all had a negative immunofluorescent staining reaction in the synovium. We suggest that an autoimmune reaction against articular cartilage antigens may play a role in the development of chondrolysis.

Aged↗
PubMed1987

Repressor gene finO in plasmids R100 and F: constitutive transfer of plasmid F is caused by insertion of IS3 into F finO.

Fertility factor F confers bacterial conjugation, a process which involves at least 20 tra genes. Resistance plasmids such as R100, R6-5, and R1 have homology with F in the tra region. Conjugal transfer of these plasmids is, however, repressed, while transfer of F is constitutive. Repression of R transfer is due to the existence of the two genes, called finO and finP; constitutive transfer of F is believed to be due to a lack of finO in F. In this paper, we report the identification and DNA sequence of the finO gene of R100, encoding a protein of 21,265 daltons. We show that F does actually encode finO, but the gene has been inactivated by insertion of IS3. Lederberg and Tatum (Nature [London] 158:558, 1946), who discovered sexuality in bacteria, may have had an Escherichia coli K-12 strain harboring such an finO F factor, which facilitated the generation of recombinant progeny useful for genetic analysis of bacteria and established the foundation for molecular genetics.

Amino Acid Sequence↗
PubMed1987

Exercise-induced changes in branched chain amino acid/aromatic amino acid ratio in the rat brain and plasma.

Central fatigue was induced by running rats on a treadmill. Amino acid and ammonia metabolism in the brain and blood were followed with time to correlate its changes with physical exhaustion. The blood ammonia level did not change during running, but was prominently increased at exhaustion. The brain level of ammonia was also prominently high at the end of exercise with a time course of change similar to that of the blood level. Plasma concentrations of branched chain amino acids (BCAA) and aromatic amino acids (AAA) increased as the animals continued to run; however, the plasma BCAA/AAA ratio was definitely depressed at exhaustion. This was also true with the brain BCAA/AAA ratio. A positive correlation was demonstrated between the plasma and brain BCAA/AAA ratios at r=0.5040 and P less than 0.05. These exercise-related changes suggest that physical exercise-induced central fatigue involves not only an increase in brain ammonia, but also a disturbance in brain amine metabolism accompanying plasma and brain BCAA/AAA ratio depression. Furthermore, the ammonia level and BCAA/AAA ratio in the brain correlated with those in the blood. It is reasonable to consider that the blood ammonia concentration and plasma BCAA/AAA ratio may serve as important indices of the clinical condition of exercise-induced central fatigue.

Amino Acids↗
PubMed1987

[Early gastric cancer associated with ectopic gastric mucosa (submucosal cysts)].

A 72 year-old man visited our hospital complaining of anorexia and hungry epigastric pain. Gastroscopy and upper G-I series examination established the diagnosis of double gastric cancers. Total gastrectomy, R2 lymphadenectomy and beta anastomosis were performed. The type IIc early cancer lesion at the pyloric vestibule was sm in depth and revealed a histological pattern of tubular adenocarcinoma. The multiple lesions on the anterior and posterior walls of the lesser curvature were a cluster of submucosal cysts, and were partially accompanied by signet-ring cell carcinoma having the depth m. The two lesions were histologically isolated without continuity, and the histology progress was PoHoeta (-) ps(-), Stage I, aw(-), ow(-). Postoperative course was uneventful. Though multiple diffuse ectopic gastric mucosa is seemed to be benign submucosal tumor of the stomach, occasional co-existence of cancer has been frequently reported. Even if the results of gastroscopy and upper G-I series results are negative, there is always a possible risk of overlooking a small cancerous focus. On detecting ectopic gastric mucosa, immediate and thorough resection seems desirable, especially when accompanied by cancer. The pathogenesis of multiple diffuse ectopic gastric mucosa has remained controversial and has been explained by the theory of either congenital or acquired aberration. From the histological findings, the pathogenesis of this case could not be determined.

Adenocarcinoma↗