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Biomedical subjects

K Aoki

Publications and source records attributed to K Aoki.

At least 397 records · Page 22Linked to original sources
PubMed1995

Preconceptional natural-killer-cell activity as a predictor of miscarriage.

There is no immunological test for the prospective identification of alloimmune causes of miscarriage. We investigated whether activity of natural killer cells was predictive of subsequent abortion in women who had had unexplained recurrent abortions and had received no treatment. 24 women with high preconceptional NK activity, defined as mean plus 1 SD of NK activity of 47 controls, had a significantly higher abortion rate in the next pregnancy than 44 women with normal levels of NK activity (71 vs 20%; relative risk 3.5; 95% CI 1.8-6.5). The preconceptional evaluation of NK activity in women with recurrent miscarriages may thus be predictive of the risk of pregnancy loss at the next conception.

Abortion, Habitual↗
PubMed1995

A macrocircular ellagitannin, oenothein B, suppresses mouse mammary tumor gene expression via inhibition of poly(ADP-ribose) glycohydrolase.

Oenothein B, a macrocircular dimeric ellagitannin, was found to be a potent and specific inhibitor of poly(ADP-ribose) glycohydrolase. Oenothein B suppressed glucocorticoid-sensitive mouse mammary tumor virus (MMTV) transcription in 34I cells. This suppression was accompanied by inhibition of glucocorticoid-induced endogeneous de-poly(ADP-ribosyl)ation of high mobility group (HMG) 14 and 17 proteins. These results suggest that de-poly(ADP-ribosyl)ation of these proteins may be closely connected with the events initiating glucocorticoid-sensitive MMTV gene transcription.

Animals↗
PubMed1995

Potentiation and depotentiation of DNQX-sensitive fast excitatory synaptic transmission in telencephalone of the quail chick.

Whole-cell perforated-patch recording in slices revealed synaptic organization of the intermediate medial hyperstriatum ventrale, a telencephalic region intimately involved in the early learning processes in chicks. Local electrical stimuli elicited excitatory post-synaptic current (EPSC) mediated by monosynaptic activation of glutamate receptors of the non-N-methyl-D-aspartate type, which was followed by a late GABAA-ergic inhibition. The initial EPSC was potentiated at least for 60 min, when a tetanic stimulation (5 Hz x 60 s) was combined with post-synaptic depolarization at or above -30 mV. In some of these neurons, the potentiated responses underwent a subsequent depression when a second tetanus was accompanied by hyperpolarization at -80 mV or below.

Animals↗
PubMed1995

Differential expression of N-CAM, vimentin and MAP1B during initial pathfinding of olfactory receptor neurons in the mouse embryo.

Olfactory receptor neurons extend their primary axons from the nasal epithelium to the olfactory bulb primordium via the frontonasal mesenchyme. In the present study, expression of neuronal markers (vimentin and MAP1B) and N-CAM was immunohistochemically investigated in the development of the olfactory system in mouse embryos. Expression of vimentin and MAP1B was first observed at early day 10 of gestation (D10) in the posterosuperior region of the medial nasal epithelium, while N-CAM was initially detected in the mesenchyme adjacent to the vimentin- and MAP1B-positive nasal epithelium. As development proceeded, the localization of neuronal marker-positive cells was mostly included in the N-CAM positive region. In addition, we adopted in situ labelling with vital dye (DiI) to directly determine the localization of the olfactory nerve and N-CAM on the same sections. We demonstrated that most extending axons were located in the N-CAM positive region. These results suggest that the expression of N-CAM plays a crucial role in the initial pathfinding of the olfactory nerve.

Animals↗
PubMed1995

Prenatal diagnosis and therapy for a patient with vitamin B12-responsive methylmalonic acidaemia.

The prenatal therapy is described of a patient with vitamin B12-responsive methylmalonic acidaemia during the last 10 days of gestation with oral administration of vitamin B12 (20 mg/day) given to a mother did not normalize her urinary excretion of methylmalonic acid (MMA), which was 14.5 mmol/mol creatinine at 32 weeks of gestation. Before delivery, the mother was excreting 18.9 +/- 3.3 mmol MMA/mol creatinine (mean value at 7 days after vitamin B12 therapy), as well as at 32-37 weeks of gestation with no therapy. After birth, the level of MMA in the infant's urine was remarkably elevated (500-700 mmol/mol creatinine); the level of MMA in maternal urine decreased dramatically after delivery. Compared with two previous reports, the length of administration was not sufficient to reduce maternal MMA excretion. In future, the length of the therapy, route of administration and total dose of vitamin B12 to maintain an efficient level of vitamin B12 in an affected fetus should be considered.

Female↗
PubMed1995

The effect of diurnal variation on the regional differences in sweating and skin blood flow during exercise.

The aim of the present study was to examine changes in the control of heat-dissipation responses to exercise associated with the diurnal variation in core temperature from the viewpoint of the regional response patterns. We studied seven men during exercise on a cycle ergometer at 100 W for 40 min at 25 degrees C at 0630 (morning) 1630 (evening) hours on 2 separate days. Oesophageal temperature (T(oes)), local skin temperature, local sweating rate (msw) on the forehead, back, forearm and thigh, and skin blood flow by laser Doppler flowmeter (LDF) on the back and forearm were measured continuously. The T(oes) at rest was significantly higher in the evening than in the morning, the difference averaging approximately 0.4 degrees C (P < 0.05). The T(oes) thresholds for each site in msw and that for back in LDF were significantly different between the two times of day (P < 0.05). The change in T(oes) thresholds for sweating and vasodilatation for morning and evening were similar to T(oes) at rest. Although msw on the forehead was significantly higher in the morning than in the evening, msw on the back was significantly higher in the evening than in the morning (P < 0.05). Total local sweating rate (msw,tot) for each site during exercise was significantly higher on the forehead than on the forearm in the morning, and on the back than on the forearm in the evening, respectively (P < 0.05). The results would suggest that the diurnal variation of heat-dissipation responses to exercise is influenced not only by a central controlling mechanism but also by changes in the regional differences.

Adult↗
PubMed1995

Systemic lupus erythematosus with necrotizing vasculitis and upregulated expression of VLA-4 antigen.

We report on a patient (S.A.), with well-defined SLE who developed a perforation of the ileum due to pathologically confirmed necrotizing vasculitis. No anti-DNA antibody was detected at the ileal perforation, and the serum complement level was normal. These findings raise the alternative possibility of a cell-mediated immune mechanism as a cause of necrotizing vasculitis. Upregulated expression and function of VLA-4 antigen on peripheral blood T cells were observed, suggesting that T cells with VLA-4 antigen may participate in the onset and/or perpetuation of vascular inflammation.

Adult↗
PubMed1995

Computed radiography in pediatrics.

Computed radiography (CR) has various advantages such as dynamic range. Diagnostic accuracy with CR using reduced radiation dose is considered comparable with that of conventional film-screen radiography in diagnosing apparent chest abnormalities. In addition to reducing the radiation dose, delineation of the various structures in infants can be obtained with CR using postprocessing. Even in cases involving inadequate exposure, appropriate information can be obtained by postprocessing. For these reasons, the cumulative dose of radiation exposure will be reduced. Thus, reduction of the radiation dose is the greatest advantage of using CR in pediatrics.

Child↗
PubMed1995

Clinical significance of beta 2-glycoprotein I-dependent anticardiolipin antibodies in the reproductive autoimmune failure syndrome: correlation with conventional antiphospholipid antibody detection systems.

OBJECTIVE: Our purpose was to determine whether beta 2-glycoprotein I-dependent anticardiolipin antibodies may represent a superior marker of reproductive risk than do conventional antiphospholipid antibodies. STUDY DESIGN: The incidence of beta 2-glycoprotein I-dependent and beta 2-glycoprotein I-independent anticardiolipin antibodies and of six conventional antiphospholipid antibodies was statistically compared between study groups with and without autoantibody-associated features of reproductive failure. Sera from 356 women were randomly selected from the frozen sera bank at the Center for Human Reproduction, Chicago. They included sera from 259 patients with autoantibody-associated features of reproductive failure such as unexplained infertility, endometriosis, and repeated pregnancy loss and 97 infertile controls. Autoantibody levels by a modified enzyme-linked immunosorbent assay for beta 2-glycoprotein I-dependent and beta 2-glycoprotein I-independent anticardiolipin antibodies and a standard enzyme-linked immunosorbent assay for anticardiolipin antibody and five other antiphospholipid antibodies were then compared. RESULTS: Patients demonstrated a significantly higher incidence of beta 2-glycoprotein I-dependent anticardiolipin antibodies (5.4%) than did controls (0%) in a modified enzyme-linked immunosorbent assay (p = 0.01). No such difference was, however, noted for beta 2-glycoprotein I-independent anticardiolipin antibodies or any one of six antiphospholipid antibodies. Two or more among six antiphospholipid antibodies, especially if involving anticardiolipin antibodies, antiphosphatidylserine and antiphosphatidylinositol, as assayed by standard enzyme-linked immunosorbent assay, were significantly more often (p = 0.02) positive in the patients (5.0%) than in the controls (0%). Moreover, positivity in two of those three antiphospholipid antibodies correlated in 59% of cases to positivity in the beta 2-glycoprotein I-dependent anticardiolipin antibody. CONCLUSIONS: As a single test beta 2-glycoprotein I-dependent anticardiolipin antibody appears to be superior to cofactor-independent anticardiolipin antibody or any other single conventional antiphospholipid antibody for the detection of autoantibody-associated conditions of reproductive failure. A broadly based panel of conventional antiphospholipid antibodies, especially if inclusive of anticardiolipid antibody, antiphosphatidylserine, and antiphosphatidylinositol, may, however, achieve similar results.

Abortion, Habitual↗
PubMed1995

Successful management of congenital protein C deficiency with recurrent pregnancy loss.

A 29-year-old woman experienced unexplained intrauterine fetal death (IUFD) three times, at 16, 27 and 27 gestational weeks. She was found to be protein C-deficient and the existence of infarction in the placenta was suspected at 20 weeks' gestation during her fourth pregnancy. Both heparin and antithrombin III were administered until delivery of a small-for-dates but live baby. Massive infarction in the placenta was evident at term. Anticoagulation with heparin is a useful treatment approach for cases of recurrent IUFD with protein C deficiency.

Adult↗
PubMed1995

Hyperglycemia facilitates urinary excretion of C-peptide by increasing glomerular filtration rate in non-insulin-dependent diabetes mellitus.

We have evaluated the feasibility of monitoring the 24-hour urinary excretion rate of C-peptide (U-CPR) as a measure of integrated beta-cell function in patients with non-insulin-dependent diabetes mellitus (NIDDM). In 37 normoalbuminuric patients, U-CPR of 117.9 +/- 9.1 micrograms/d (mean +/- SEM) during the poorly controlled glycemic phase (fasting plasma glucose [FPG], 171 +/- 7 mg/dL; hemoglobin A1C [HbA1c], 8.8% +/- 0.4%) was significantly higher than the value of 83.3 +/- 13.7 micrograms/d (P < .001) during the well-controlled phase (FPG, 135 +/- 6 mg/dL; HbA1c, 7.0% +/- 0.2%), although the plasma insulin response to meals was lower during the former phase (53.3 +/- 6.3 microU/mL) versus the latter phase (65.7 +/- 6.6, P < .005). Endogenous creatinine clearance (Ccr) was significantly elevated during the poorly controlled phase (105.4 +/- 7.3 v 88.7 +/- 4.7 mL/min, P < .005). In 26 microalbuminuric patients, the plasma insulin response was greater during good glycemic control, but U-CPR did not differ between the two phases. Ccr was comparable at two phases in this group (92.7 +/- 7.4 v 91.1 +/- 5.9 mL/min, NS). U-CPR correlated positively with Ccr in both groups (r = .593, P < .001 in normoalbuminuria; r = .585, P < .001 in microalbuminuria). In addition, when biosynthetic human C-peptide was infused intravenously at an identical rate in two healthy subjects, resulting steady-state plasma levels of CPR were lower, and fractional U-CPR was higher during the moderately hyperglycemic phase versus the euglycemic phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

A prospective study on pregnancy risk of antiphospholipid antibodies in association with systemic lupus erythematosus.

This prospective study is an attempt to address the issues of whether or not antiphospholipid antibodies (aPL) constitute a significant risk factor for pregnancy in individuals with systemic lupus erythematosus (SLE) and whether or not combination therapy of high-dose prednisolone (PSL) and low-dose acetylsalicylic acid (ASA) offers efficient control. Antibodies against six phospholipids were measured in sera of patients with stable SLE who had no severe complications before pregnancy, and were followed up during subsequent pregnancies. Four of 12 patients with SLE demonstrated aPL-positivity. Six of 8 patients without aPL had appropriate-for-date (AFD) live babies, the remaining two suffering intrauterine fetal death (IUFD) in the first trimester, one having a chromosome abnormality. Two aPL-positive patients treated only with 5-15 mg/day PSL during pregnancy ended in IUFD in the second trimester. In contrast, the other two patients treated with high-dose PSL and low-dose ASA each had AFD live babies at 38 weeks gestation. The results suggest that APL is a crucial risk factor in pregnancy with stable SLE. Combination therapy of high-dose PSL and low-dose ASA may enable aPL-positive patients with SLE to have AFD live babies.

Antibodies, Antiphospholipid↗
PubMed1995

Age-related changes in ConA-induced cytokine production by splenocytes from senescence accelerated mice SAMP8.

In vitro production of interleukin-2 (IL-2), IL-4, IL-5 and interferon-gamma (IFN-gamma) by splenocytes stimulated with concanavalin A (ConA) was studied in senescence-accelerated mice (SAMP8; 2-14.5 months old) by employing AKR (2-9 months old), origin of SAM strain, as controls. Male and female SAMP8 mice showed an age-related decrease in IL-2 production from the age of 9 months and the phenomena were accompanied by an increase in IFN-gamma production with a large increment. AKR mice showed no decrease in IL-2 production even at 9 months of age, but there was an increase in IFN-gamma production showing levels lower than those in SAMP8 mice. Between IL-2 and IFN-gamma production during the ages of 2-9 months, there were negative correlations in male and female SAMP8 mice and a positive correlation in female AKR mice. The levels of IL-4 production were lower in SAMP8 than in AKR mice, although there was no difference in IL-5 production between SAMP8 and AKR mice. Male and female SAMP8 mice showed a positive correlation between IL-5 and IFN-gamma production. Only in SAMP8 females was an increase in IFN-gamma accompanied by an increase in IL-4. From these changes in the cytokine production profile was it concluded that SAMP8 mice were senescence-accelerated in immuno-responses in comparison with AKR mice and had some functional deficiency with respect to IL-4 production, a part of which resulted from over-production of IFN-gamma.

Aging↗
PubMed1995

Prevalence of macro- and microvascular diseases in non-insulin-dependent diabetic and borderline glucose-intolerant subjects with insulin resistance syndrome.

This study was undertaken to ascertain whether patients with insulin resistance syndrome, a cluster of risk factors for coronary artery disease (CAD), are really a high risk population for macro- and microvascular diseases in Japanese NIDDM and borderline glucose-intolerant subjects. A diagnosis of insulin resistance syndrome was made if four of the six following criteria are satisfied: glucose disposal rate < 2.2 mg/kg/min, fasting plasma IRI > 15 microU/ml or peak plasma IRI > 100 microU/ml during meal tolerance test, plasma triglyceride > 150 mg/dl at fasting or > 200 mg/dl after meal, serum HDL-cholesterol < 40 mg/dl, blood pressure > 140 mm Hg systolic and > 90 mm Hg diastolic or treatment with antihypertensive agents, and body mass index (BMI) > 27 for men or > 25 for women. We compared the prevalence of CAD, cerebral vascular disease (CVD), peripheral vascular disease (PVD), retinopathy and nephropathy between the insulin resistance syndrome group (group A, n = 57) and the remaining group (group B, n = 164). Both groups did not differ with respect to age, duration of diabetes, BMI, fasting plasma glucose, HbA1c, composition of NIDDM and borderline glucose-intolerance (BGI) or treatment modality. The prevalence of CAD was significantly higher in group A compared with that in group B (31.6% vs. 14.0%, P < 0.002), but not for CVD (8.8% vs. 3.7%, respectively, P = 0.12) or PVD (1.8% vs. 2.4%, respectively, P = 0.76). The prevalence of late-stage retinopathy in group A was significantly higher than that in group B (12.3% vs. 2.4%, respectively, P < 0.005). Macroalbuminuria, but not microalbuminuria, was significantly higher in group A than that in group B (12.3% vs. 3.6%, P < 0.02). We conclude that the insulin resistance syndrome preferentially increases the development of CAD, and is also involved in the progression of microvascular diseases.

Adult↗
PubMed1995

Metabolic regulation and microangiopathy in a cohort of Japanese IDDM-patients.

In Caucasian patients with insulin-dependent diabetes mellitus (IDDM) proliferative diabetic retinopathy (PDR) and persistent proteinuria (PP) are associated, and major risk factors for development of microangiopathy have been identified. The aim of the present study was to evaluate whether these risk factors are also relevant and whether an association exists between the microangiopathic complications in Japanese IDDM-patients. A clinic-based cohort of 324 Japanese IDDM-patients was followed (a mean follow-up of 7 years). Annual examination for development of PDR and PP was performed. Fifty-eight patients developed PDR and 24 developed PP. Development of PDR was associated to high HbA1c-levels, i.e., the 4th quartile (RR 7.9, P < 0.0001), background retinopathy at admission (RR 9.9, P < 0.0001), high age at diabetes onset (RR 2.9, P < 0.0001) and female gender (RR 1.7, P < 0.05). Development of PP was associated to high HbA1c-levels (RR 2.8, P < 0.001) and background background retinopathy at admission (RR 7.9, P < 0.0001). The risk of developing PP was 9 times higher in patients developing PDR than in patients not developing PDR (P < 0.0001). The effect of metabolic control in our cohort was similar to that found in the DCCT and SDIS studies. In conclusion, development of PP is closely associated with PDR, also in Japanese IDDM-patients. The effect of metabolic control is the same as in Caucasian patients. Development of malignant angiopathy in IDDM-patients is not confined to Caucasian IDDM-patients, and the incidence rates are comparable to those found in Caucasian IDDM.

Adolescent↗
PubMed1995

Prevalence of the myelodysplastic syndromes in Japan.

To determine the prevalence of the myelodysplastic syndromes (MDS) in Japan, we conducted a nationwide survey in 1991. The survey included the sex, birth date and type of MDS of the patients from all (n = 2315) hospitals with 200 beds or more and 188 hospitals randomly selected from 7526 hospitals (1/40) with 199 beds or less. The point prevalence of MDS was estimated to be almost 3000 as of September 1, 1991, and it was 3.4 per 100,000 men of 15 years old or older and 2.1 per 100,000 women of 15 years old or older. Refractory anemia (RA) was most common (51%) followed by RA with excess of blasts (RAEB; 18%) and RAEB in transformation (RAEB-t; 14%). RAEB, RAEB-t and chronic myelomonocytic leukemia (CMML) showed a high male/female ratio (3.0 or higher) although the sex ratio of other types was almost 1.0.

Adolescent↗