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Biomedical subjects

A Yoshida

Publications and source records attributed to A Yoshida.

At least 343 records · Page 19Linked to original sources
PubMed1997

Intracytoplasmic injection with late spermatids: a successful procedure in achieving childbirth for couples in which the male partner suffers from azoospermia due to deficient spermatogenesis.

OBJECTIVE: To investigate the feasibility of using late spermatids in intracytoplasmic sperm injection (ICSI) for patients in which there is a total lack of normal and testicular sperm. DESIGN: Clinical study. SETTING: Private fertility center with adjacent laboratory facilities. PATIENT(S): Thirty-six males diagnosed with azoospermia underwent testicular biopsy and the resulting spermatids from nine patients were used to fertilize oocytes retrieved from their respective wives by ICSI. INTERVENTION(S): Intracytoplasmic spermatid injection of oocytes with late spermatids obtained by testicular biopsy. MAIN OUTCOME MEASURE(S): Fertilization, pregnancy, and delivery rates. RESULT(S): Three of the cases resulted in pregnancies with childbirth occurring in all three, identical twins in one, and individual singletons in the other two cases. CONCLUSION(S): It is possible to achieve successful levels of pregnancy and childbirth in cases of azoospermia by intracytoplasmic injection of late spermatids.

Birth Weight↗
PubMed1997

Association between the short-term natural history of diabetic macular edema and the vitreomacular relationship in type II diabetes mellitus.

PURPOSE: The authors ascertain the association between the short-term natural history of untreated diabetic macular edema and the vitreomacular relationship. METHODS: The authors prospectively studied 82 type II diabetic patients with clinically significant macular edema over a six-month period. They used multiple linear regression analysis to evaluate the effect of ten variables on the short-term natural history of macular edema 6 months after diagnosis: age; gender; diabetes duration at diagnosis of macular edema; hemoglobin A1; insulin use; presence of proteinuria; presence of systemic hypertension, cardiac disorders, or both; degree of diabetic retinopathy; history of panretinal photocoagulation; and vitreomacular relationships, as determined by present lens biomicroscopy. RESULTS: At study entry, 22 (27%) eyes had vitreomacular separation and 60 (73%) eyes did not. Macular edema spontaneously resolved in 27 (33%) eyes 6 months after diagnosis. Of the 22 eyes with vitreomacular separation at study entry, 12 (55%) had spontaneous resolution of macular edema after 6 months, whereas only 15 of 60 (25%) of the eyes with vitreomacular adhesion at study entry had spontaneous resolution (P = 0.01). Stepwise regression analysis indicated that vitreomacular separation (P = 0.01) and diabetes duration (P = 0.03) contribute to resolution of macular edema. Of the 27 eyes with resolved macular edema, 17 (63%) had improved visual acuity of more than two lines, whereas no eyes had improved visual acuity if macular edema persisted. The prevalence of improved visual acuity of more than two lines was significantly higher in eyes with vitreomacular separation at study entry (36%, 8/22) than in eyes without (15%, 9/60; P = 0.04). CONCLUSION: Our findings suggest that vitreomacular separation may promote the spontaneous resolution of diabetic macular edema and consequently improve visual acuity.

Adolescent↗
PubMed1997

Responses of catecholamines, renin-angiotensin system, and atrial natriuretic peptide to exercise in untrained men and women.

1. Plasma norepinephrine (NE), epinephrine (E), renin activity (PRA), angiotensin II (ATII), aldosterone (ALD), and atrial natriuretic peptide (ANP) were measured in 20 male and 15 female subjects during submaximal treadmill test. 2. Exercise duration was not different between the two groups (male vs. female: 13.4 +/- 0.8 min vs. 11.6 +/- 0.7 min, ns). Female subjects had higher heart rate during exercise, while systolic blood pressure at peak exercise was higher in male subjects. 3. Plasma NE, E, ANP, and ATII responses were comparable between male and female subjects, but PRA both at rest and during exercise and ALD at rest were significantly higher in male subjects. 4. Cardiac responses to submaximal exercise were different between male and female subjects, but neurohormonal responses were comparable between the two groups except for the high PRA at rest and during exercise and high plasma ALD at rest in male subjects.

Adult↗
PubMed1997

Influence of extracellular H+ and Ca2+ on Ro 22-9194-induced block of sodium current in cardiac myocytes.

1. Ro 22-9194 reduced the Na current in ventricular myocytes in either a tonic block or phasic block manner. 2. Ro 22-9194 had a higher affinity to the inactivated state (Kdi = 10.3 microM) than to the rested state (Kdrest = 180 microM). 3. Extracellular acidification enhanced the tonic block but reduced the phasic block. 4. Elevation of extracellular Ca2+ inhibited the enhancing effects of extracellular acidification. 5. These findings suggest that Ro 22-9194 strongly inhibits Na+ channels of the ventricular myocytes of the diseased hearts, characterized by the depolarized cell membranes and by acid conditions.

Animals↗
PubMed1997

Clearance of pentosidine, an advanced glycation end product, by different modalities of renal replacement therapy.

We recently demonstrated that pentosidine, an advanced glycation end product, accumulates markedly as albumin-linked form (Palb) and in free-form (Pfree) in the plasma of patients with end-stage renal failure. The present study was undertaken to examine the clearance of Palb and Pfree by different modalities of renal replacement therapy, that is, hemodialysis (HD), continuous ambulatory peritoneal dialysis (CAPD), and renal transplantation. HD cleared Pfree (9.4 +/- 4.3 nmol/kg/HD) but not Palb, by diffusion but not by membrane adsorption, whereas CAPD cleared both Palb (4.03 +/- 2.01 nmol/kg/day) and Pfree (2.43 +/- 1.24 nmol/kg/day). Plasma total pentosidine levels were significantly (P < 0.05) lower in CAPD (0.97 +/- 0.41 nmol/ml) than in HD (1.19 +/- 0.41 nmol/ml), as the result of a lower serum albumin level in the former patients. Indeed, Palb expressed per mg albumin was virtually identical in HD and CAPD. By contrast, Pfree was significantly lower in CAPD than in HD. Palb levels were significantly correlated with plasma Pfree levels in both HD and CAPD patients, but not in the CAPD dialysate. Pentosidine transport across the peritoneum occurs mainly by diffusion, both as Palb and Pfree. Interestingly, peritoneal Palb clearance (0.17 +/- 0.07 ml/min) significantly (P < 0.00001) exceeded albumin clearance (0.11 +/- 0.05 ml/min). Palb levels being significantly higher (P < 0.0005) in the peritoneal fluid (36.28 +/- 18.55 pmol/mg) than in the serum (27.12 +/- 11.71 pmol/mg), thus raises the possibility of a facilitated diffusion of Palb or an active transport mechanism for protein-linked pentosidine into the peritoneal cavity. After renal transplantation, plasma Pfree fell rapidly, remained barely detectable after one month, and returned to normal at six months. By contrast, Palb fell more slowly and remained significantly above normal at six months, but returned eventually to normal levels. These findings demonstrate that: (1) both HD and CAPD remove Pfree; (2) the peritoneal clearance of Palb, might contribute to the lower level of plasma pentosidine in CAPD than in HD patients; and (3) renal transplantation is the best therapeutic modality to normalize both Palb and Pfree levels.

Adult↗
PubMed1997

A novel mutation causing complete deficiency of thyroxine binding globulin.

OBJECTIVE: Thyroxine binding globulin (TBG) is a serum protein that transports thyroxine. Three naturally occurring mutations have been reported to produce complete deficiency of TBG (TBG-CD). The first to be reported was TBG-CD5 in caucasian families of French-Canadian origin and consists of substitutions in exons 2 and 3. TBG-CD of English ethnic origin (TBG-CD6) is characterized by a thymine deletion in codon 165 (exon 1). In Japanese families with TBG-CD (TBG-CDJ), a variant has been characterized with a deletion of the first base of the codon for amino acid 352 (exon 4) in the common type TBG. In this communication we report a new type of TBG-CD in a family of Japanese ethnic origin that is characterized by a single nucleotide substitution in place of two nucleotides in exon 1. This is an uncommon mutation which we have been unable to find in other genes. DESIGN: Exons of the TBG gene amplified by the polymerase chain reaction (PCR) were subcloned and sequenced. To examine for the presence of the same mutation in potentially affected individuals, we performed PCR using primer-directed mutagenesis or allele-specific amplification. PATIENTS: The index case was of Japanese ethnic origin, and was diagnosed as having TBG deficiency on the basis of undetectable serum TBG. The patient consented to this evaluation and the protocol was in accordance with IRB standards. MEASUREMENTS: Serum thyroid hormones, thyrotrophin binding inhibitory immunoglobulin and TBG concentrations were measured by conventional radio-immunoassay. Genomic DNA was extracted from white blood cells. RESULTS: In the index case exons 2, 3 and 4 were normal, but nucleotides 144 (cytosine) and 145 (thymine) in exon 1 were substituted with a single base (adenine) which induced a frame shift in the reading frame, resulting in an early stop codon at codon 51. The patient and his daughters were confirmed as having this mutation using primer-directed mutagenesis or allele-specific amplification. CONCLUSIONS: We have described a novel mutation in the TBG gene in a Japanese family. This results in a frame shift and premature stop codon, and was associated with undetectable serum TBG in the index case.

Exons↗
PubMed1997

Sexual function and clinical features of patients with Klinefelter's syndrome with the chief complaint of male infertility.

In this report, we present the overall sexual function and clinical features of patients with Klinefelter's syndrome with the chief complaint of male infertility. The study consisted of 40 patients with a control group of 55 infertile non-azoospermic males with a normal 46,XY karyotype who visited the Reproduction Center of Toho University Hospital during the 5.5-year period between January 1991 and June 1996 with the chief complaint of male infertility. Among the 40 patients with Klinefelter's syndrome, 38 cases were pure 47,XXY, one case was 47,XXY with a pericentric inversion of chromosome 9 and one case was a mosaic of 46,XY/47,XXY(2:28). Thirty-nine of these 40 patients were azoospermic and one (47,XXY) had severe oligoasthenozoospermia. The sexual function of the patients was evaluated according to their responses to a preliminary questionnaire devised by our department. There was no significant difference in the frequency of sexual function disturbances between the patients with Klinefelter's syndrome and the control group (67.5% vs. 60.0%; chi 2 analysis; p = 0.454). The mean frequency of sexual intercourse per month in the patients with Klinefelter's syndrome was significantly higher than in the control group (4.4 +/- 2.8 vs 3.3 +/- 1.6: Welch's t-test, p < 0.05). A possible explanation for this variation may lie in the fact that many of these patients were diagnosed with azoospermia poor to the administration of the questionnaire and may have wished to continue to have relations as a couple.

Adult↗
PubMed1997

Color pattern formation on the wing of the butterfly Pieris rapae. 1. Cautery induced alteration of scale color and delay of arrangement formation.

Experimental approaches to color pattern formation of lepidopteran insects have been made exclusively by analyzing pattern alterations in adult wings induced by operations. We microcauterized the presumptive black region of the dorsal forewing of the butterfly Pieris rapae and analyzed not only the resultant color pattern in the adult wing but also the cell behavior in the pupal wing epidermis around the injury. Cautery induced color alterations were as follows: (i) cautery up to 49.5 h after pupation resulted in white regions appearing within the black region while later cauteries induced larger white regions; (ii) cautery between 50 and 59.5 h resulted in the white regions induced by the cauteries being dramatically decreased; (iii) cautery after 60 h resulted in white regions that had almost disappeared. The examination of the cell behavior in the pupal wing epidermis after cauteries showed that the row formation of scale precursor cells was delayed. This delayed area varied with the time of cautery, in the same manner as that in the induced white area in the adult wing ((i)-(iii) above). The relationship between scale color alteration and the developmental delay of the scale row formation is discussed.

Animals↗
PubMed1997

Color pattern formation on the wing of a butterfly Pieris rapae. 2. Color determination and scale development.

It has been shown that microcautery on the prospective apical black region of the early pupal forewing of a butterfly, Pieris rapae, causes alteration of the scale color on the adult wing and a delay in histogenesis of the pupal wing. From these results, it has been assumed that the developmental delay of scale cells in the pupal wing alters their developmental fate and the hypothesis that different color fates of scales are determined by differences in the developmental timetables between scale cells is proposed. In this study, we attempted to find the developmental timetables of individual scales expressing specific color to test this hypothesis. It was found that the holes on the upper surface of a scale become larger as they develop and the hole sizes of scales in the white region are always larger than in the black region on the same wings either during pupal period or after eclosion. This suggests that the scale hole size is a good index that reflects developmental rate of the scale and a difference in the hole size between adult scales is attributed to a difference in the developmental timetables when their ancestral scale precursor cells were in the pupal period. A comparison of the hole sizes between adult scales in different color regions suggested that normal white scales were in a more advanced state than were the black ones but white scales induced by microcautery were in a less advanced state than black ones on the same wing. This supports our hypothesis.

Animals↗
PubMed1997

Mutations associated with Sjögren-Larsson syndrome.

Sjögren-Larsson syndrome (SLS), a rare autosomal disorder characterized by ichthyosis, spastic neurological disorders and oligophrenia, is associated with deficiency of fatty aldehyde dehydrogenase encoded by a gene on chromosome 17q11.2. Mutations of the gene (GDB symbol ALDH10) were recently identified in three SLS patients. Another aldehyde dehydrogenase isozyme. ALDH3, also has a high activity for fatty aldehyde oxidation, and is encoded by a gene in chromosome 17q11.2. Abnormality of the ALDH3 gene could also cause a similar syndrome. The examination of the ALDH3 locus of three additional SLS patients showed that two are heterozygous with C-->G at nt 985 (Pro-->Ala at protein position 329). However, the mutation was found to be common (frequency of the atypical allele is about 0.25) in normal subjects, and not related to SLS. Isoelectric focusing analysis indicated that ALDH3 is hardly expressed in normal as well as patients' fibroblast cells, while ALDH10 expressed in the normal cells is diminished in the three patients' cells. The level of ALDH10 mRNA is also low in the patients' cells. The examination of the ALDH10 locus revealed the existence of a 3 base deletion coupled with a 21 base insertion at intron 6/exon 7 junction in one patient. This abnormality is the same as that found in the patient previously reported by other investigators. One patient is associated with a 2 base deletion at nt 1297 and consequent premature chain termination at protein position 434. Another patient is a compound heterozygote for the same 2 base deletion at nt 1297 and a 5 base insertion at nt 1311 and premature chain termination at protein position 457. Unique characteristics of the SLS mutations are pointed out.

Aldehyde Dehydrogenase↗
PubMed1997

Changes in size of the functional cyst on ultrasonography during early pregnancy.

To clearly define the clinical behaviors of the functional cyst by ultrasonography and distinguish this cyst from other sonolucent ovarian cysts in pregnancy, changes in functional cyst size during early pregnancy were retrospectively evaluated with the cyst diameters derived from ultrasonic records of 58 pregnant patients with functional cysts. Of the 58 cases, 7 cases of functional cysts over 6 cm in diameter and 5 cases after 15 weeks were observed. Percent changes in cyst size per weeks of gestation were calculated from diameters of all cases. These percent changes were averaged respectively in four chronologic groups (5-7, 7-9, 9-12, and 12-15 weeks of gestation). As a result, although the mean percent change in cyst size showed a tendency to increase from 5 to 7 weeks (+0.9% per week), it turned negative after 7 weeks, and the decreasing tendency grew as gestation advanced (7-9 weeks: -8.3% per weeks; 9-12 weeks: -11.7% per weeks; 12-15 weeks: -15.2% per week). Therefore, the result showed that the maximum cyst size is reached at about 7 weeks with gradual diminution thereafter and the sonolucent ovarian cyst may be followed as a functional cyst, even if it is large or persists after 14 weeks.

Adnexa Uteri↗
PubMed1997

Changes in corneal and lens autofluorescence and blood glucose levels in diabetics: parameters of blood glucose control.

PURPOSE: We investigated corneal and lens autofluorescence in patients with proliferative diabetic retinopathy (PDR) to determine a correlation between the two parameters and blood glucose levels and HbA1c. METHODS: Corneal and lens autofluorescence levels in 17 PDR patients and 8 healthy controls were measured with a fluorophotometer fitted with an anterior segment adapter. We measured the lower blood glucose level (BS1), corneal autofluorescence (CA1), and lens autofluorescence (LA1) simultaneously and the higher blood glucose level (BS2), CA2, and LA2 simultaneously on the same day. We defined parameter changes as: delta BS = BS2 - BS1, delta CA = CA2 - CA1, and delta LA = LA2 - LA1. RESULTS: Corneal and lens autofluorescence significantly increased in the patients, compared with the controls (p < 0.001). Lens autofluorescence had a significant positive correlation with HbA1c (r = 0.656, p < 0.01) in the patients. delta CA (ngEq/ml) correlated significantly with delta BS (mg/dl) (r = 0.631, P < 0.01). CONCLUSIONS: Results suggest that lens autofluorescence might represent the long-term control of diabetes, and corneal autofluorescence levels may represent short-term changes in the blood glucose level, because hyperglycemia accelerates with increasing corneal autofluorescence in PDR patients. Corneal and lens autofluorescence may be related to the breakdown of the blood-aqueous barrier.

Adult↗
PubMed1997

Structural abnormalities of autosomal chromosomes in the male partner do not influence fertilization and early development of embryos after intracytoplasmic sperm injection.

The objective of this study was to determine whether or not abnormalities in the autosomal structure of the male partner have any influence on fertilization and early embryo development after intracytoplasmic sperm injection (ICSI). Thirty-seven couples in whom the male partners were examined by the same andrologist were included in this study. Six couples (group I) in whom the male partner possessed autosomal structural abnormality underwent seven ICSI cycles. As a control group, 31 couples (group II) in which the male partner was karyotypically normal underwent 41 ICSI cycles. Although the normal fertilization rates seen in group I were significantly higher than those in group II (P < 0.05), there was no significant difference in the cleavage rates between the two groups. We did not perform the analysis of the female partner's chromosomes, but we surmise that structural autosomal abnormalities in the male partner do not adversely influence fertilization at ICSI and early development of embryos.

Adult↗
PubMed1997

Dicentric Y chromosome in an azoospermic male.

We describe a 28 year old male with a pseudodicentric Y chromosome who suffered from azoospermia attributed to maturation arrest of the primary spermatocyte, as diagnosed by testicular biopsy. Chromosome analysis, using G, Q and C banding techniques, revealed an abnormal karyotype of 45,X[7]/46,X,psu dic (Y)(pter-->q11.2::q11.2-->pter)[33]. Polymerase chain reaction (PCR) DNA analysis did not detect the absence of DAZ and RBM1 which are candidates for azoospermic factor (AZF) genes. Therefore, it is suggested that the maturation arrest of the primary spermatocyte in this patient was caused either by a pairing dysfunction between the X and Y chromosomes during meiosis or by deletions in the autosomal or the Y chromosomal spermatogenesis controlling genes, excluding DAZ and RBM1.

Adult↗
PubMed1997

Abnormal cyanide metabolism in uraemic patients.

BACKGROUND: We previously investigated the factors involved in uraemic neuropathy in patients undergoing regular haemodialysis and found a significant relationship between the severity of vibration sensation impairment and the patients' smoking habits. The administration of methylcobalamin markedly improved the severity of uraemic neuropathy in terms of vibration perception thresholds. We presumed that abnormal cyanide metabolism is involved in the development of uraemic neuropathy. METHODS: Serum levels of thiocyanate (SCN-), the detoxication product of cyanide, were determined in 12 patients with preterminal chronic renal failure (PCRF), 30 patients undergoing regular haemodialysis (HD patients), and 13 healthy volunteers as a control group. Nine of the 30 HD patients were smokers. In addition, in 10 HD patients without smoking habits and 10 non-smoking healthy volunteers, the proportion of each vitamin B12 analogue in total vitamin B12 was estimated. RESULTS: The mean serum SCN- level of the 12 PCRF patients (5.1 +/- 1.5 micrograms/ml) was significantly higher than that of the control (2.8 +/- 0.9 micrograms/ml) (P < 0.01). The mean SCN- level before haemodialysis in the 21 non-smoking HD patients was identical to that in the PCRF group, whereas the level in the nine smoking HD patients (7.2 +/- 1.8 micrograms/ml) significantly higher than that in the non-smoking subgroup (P < 0.01). In 16 HD patients with methylcobalamin treatment, serum SCN- levels were lower than in those without methylcobalamin treatment (4.5 +/- 0.5 micrograms/ml in non-smoking subgroup, P < 0.05). And in the methylcobalamin-treated subgroup (n = 5), the proportion of each vitamin B12 analogue in total vitamin B12 was normal. In the untreated subgroup (n = 5), the proportion of cyanocobalamin fraction (10.5 +/- 2.6%) was as high as the level in Leber's disease patients, while the proportion of methylcobalamin fraction was low. And the serum cyanocobalamin level was higher in the treated subgroup. CONCLUSION: In uraemic patients, cyanide detoxication capability is impaired because of a reduced SCN- clearance, and increased cyanocobalamin synthesis indicates elevation of cyanide pool, which would be related to the development of uraemic neuropathy. Methylcobalamin was considered to be utilized in cyanide detoxication process via cyanocobalamin synthesis.

Adult↗
PubMed1997

Pertechnetate thyroid uptake is not always suppressed in patients with subacute thyroiditis.

The authors studied the clinical courses and immunologic aspects in 15 patients (age range, 32-69 years old; 14 women) with clinical features that were similar to subacute thyroiditis (SAT). In 2 patients (group A) whose thyrotropin-binding inhibitory immunoglobulins (TBII) and thyroid stimulating antibody (TSAb) showed strongly positive activity at the initial visit, Tc-99m pertechnetate thyroid uptake (Tc-99m uptake) was elevated (5.6% and 3.8%, respectively, normal; 0.7-3.0%). In 6 (group B) of 13 other patients, Tc-99m uptake was not completely suppressed (2 normal, 4 near normal) and imaging showed uptake in one lobe. In 7 (group C), however, there was no evidence of uptake in either lobe. Inflammatory process was localized in one lobe in all group B patients, and was in both lobes in all group C patients but one. Serum TSH levels were detectable in at least 4 patients (2 group B, 2 group C) low in all. There were no patients in both groups B and C in whom TBII and/or TSAb were detected at the initial visit. In SAT, marked suppression of Tc-99m uptake may be ascribed mainly to inflammatory follicular cell damage, but it is not always suppressed, owing to an association similar to Graves' disease and other unknown mechanism(s).

Adult↗
PubMed1997

Posterior fracture-dislocation of the shoulder with infraspinatus interposition: the buttonhole phenomenon.

We present a case with a posterior fracture-dislocation in which interposition of the infraspinatus precluded closed reduction by means of standard manipulation. The fractured greater tuberosity included the lesser tuberosity, allowing the infraspinatus to dislocate anterior to the dislocated humeral head and interpose between the humeral head and the glenoid cavity. The infraspinatus constricted the humeral neck together with the teres minor. Traction in the zero-position was thus required for resolution of constriction and subsequent reduction. Computed tomography was useful to demonstrate interposition of the infraspinatus and to plan the treatment.

Adult↗