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Biomedical subjects

K Okamura

Publications and source records attributed to K Okamura.

At least 271 records · Page 15Linked to original sources

Regression of coronary atherosclerosis by combined LDL-apheresis and lipid-lowering drug therapy in patients with familial hypercholesterolemia: a multicenter study. The LARS Investigators.

The purpose of the LDL-Apheresis Regression Study (LARS) group, which included 13 institutions in Japan, was to investigate the effects on coronary atherosclerosis of LDL-apheresis combined with cholesterol-lowering drugs. Changes in coronary artery stenosis were assessed angiographically in 37 patients with familial hypercholesterolemia (7 homozygotes and 25 heterozygotes) and hypercholesterolemia which had not been defined as familial hypercholesterolemia (5 patients) by visual judgement and computer analysis. Definite regression was observed in 14 cases, including 4 homozygotes and 10 heterozygotes and others. Regression occurred as often in patients with severe coronary artery disease (2 or more vessel disease) as in those having less severe disease. Our results encourage initiation of aggressive cholesterol-lowering therapy to produce regression of coronary atherosclerosis in FH patients at high risk for cardiovascular events.

Adult↗

Multicentric development of pancreatic intraductal carcinoma through atypical papillary hyperplasia.

We report a case of multiple intraductal carcinomas of the pancreas associated with diffuse atypical papillary hyperplasia. A 67-year-old Japanese man with a complaint of epigastric pain was examined by endoscopic retrograde pancreatography, which demonstrated multiple dilated branches of the pancreatic duct in the body and tail of the pancreas. Histologic examination on the resected pancreas showed diffuse atypical papillary hyperplasia in multiple dilated ducts associated with multiple intraductal carcinomas. Histologic features are described and multicentric carcinogenesis through atypical papillary hyperplasia is discussed.

Aged↗

Scoparic acid A, a beta-glucuronidase inhibitor from Scoparia dulcis.

The 70% EtOH extract of Scoparia dulcis showed inhibitory activity against beta-glucuronidase from bovine liver. Bioassay-directed fractionation of the active extract led to the isolation of three labdane-type diterpene acids, scoparic acid A [1] [6-benzoyl-12-hydroxy-labda-8(17), 13-dien-18-oic acid], scoparic acid B [2] [6-benzoyl-14,15-dinor-13-oxo-8(17)-labden-18-oic acid], and scoparic acid C [3] [6-benzoyl-15-nor-14-oxo-8(17)-labden-18-oic acid], the structures of which were established by spectral means, including X-ray analysis. Scoparic acid A was found to be a potent beta-glucuronidase inhibitor.

Acetylation↗

Papillary adenoma of the pancreas with excessive mucin secretion.

A 68-year-old woman with papillary adenoma of the pancreas with excessive mucin secretion is reported. The patient was initially diagnosed as having chronic pancreatitis because of a history of repeated attacks of pancreatitis and localized dilatation of the main pancreatic duct. Four years later, endoscopic retrograde pancreatography showed markedly diffuse dilatation of the entire main pancreatic duct with amorphous filling defects of mucin. Excretion of mucin was observed through the enlarged orifice of Vater's ampulla. The patient was treated with distal pancreatectomy, and papillary adenoma with abundant mucin in the cytoplasm was histologically demonstrated. We describe unique clinical features of "mucin-producing pancreatic tumor" and discuss an important role of endoscopic retrograde pancreatography in the diagnosis.

Ampulla of Vater↗

Preserved thyroidal secretion of thyroxine in acromegalic patients with suppressed hypophyseal secretion of thyrotrophin.

OBJECTIVE: We have assessed the mechanisms which maintain euthyroidism in acromegalic patients despite the suppression of thyrotrophin (TSH) secretion. MATERIALS: Fourteen untreated patients with acromegaly were analysed. Ten patients were also studied after pituitary surgery. METHODS: Thyroid hormones, growth hormone (GH), insulin-like growth factor-I (IGF-I) and thyroidal uptake of radioactive iodine, thyrotrophin releasing hormone (TRH) test and basal metabolic rate (BMR) were measured before and after pituitary surgery. RESULTS: Nine patients had palpable goitres. The TSH response to TRH stimulation was suppressed in eight patients, who maintained normal serum levels of total T3, T4 and free T4. The patients with normal TSH response had lower levels of free and total T4 than controls. The response of TSH to TRH correlated inversely with the serum level of total and free T4, and also with the plasma level of IGF-I (r = -0.74, P less than 0.05, n = 9). After pituitary surgery, the serum levels of total and free T4 were elevated for at least up to 6 months, with a decrease in the T3/T4 ratio and the BMR. CONCLUSION: GH may have a direct stimulatory action on the thyroid secretion of T4 possibly via increased IGF-I, despite suppressed TSH secretion. The post-operative elevation of serum T4 suggests the persistent secretion of T4 from the thyroid gland, in spite of instantaneous normalization of the accelerated conversion of T4 to T3, even after reduction of excess GH secretion.

Acromegaly↗

Risk factors in the pregnancy of patients with systemic lupus erythematosus: association of hypocomplementaemia with poor prognosis.

Fetal wastage is still high in the pregnancies of patients with systemic lupus erythematosus (SLE). We examined retrospectively the cases of 38 patients with inactive SLE in whom pregnancy was either desired or had already been obtained. The prevalence of antiphospholipid antibodies in the group with fetal loss was high. The antibodies were, however, also detected in five of 14 patients who had had a live birth. It was noted that low levels of serum complement activity (CH50 less than 25 U/ml) occurred in five of six patients with fetal loss, but in only two of 22 with a live birth. Serial studies also confirmed a close association between decreased serum complement activity and poor fetal prognosis in lupus pregnancy. Treatment with increased doses of prednisolone may help to achieve successful live births. Thus hypocomplementaemia may be associated with a worse prognosis for the fetus in the pregnancies of some patients with SLE in remission.

Adult↗

A probable case of superfecundation.

Discordant twins are of obstetrical concern because of high morbidity and mortality of either the smaller or the larger twin, or both. The discordance becomes apparent usually in the second trimester. We report a case of discordant twins diagnosed in the 10th week of gestation, which was concluded to be a case of superfecundation. The discordancy was persistent up to the 35th week of gestation, when 2 baby boys were born by cesarean section because of preeclampsia. The postnatal courses of the babies were uneventful.

Adult↗

Small hyperechoic renal tumors displaying no fat content on CT.

We report two cases of small renal adenocarcinoma and one case of small angiomyolipoma, which were identified as hyperechoic tumors by ultrasonography. None of the three tumors displayed fat content on plain CT. Since CT cannot reliably identify the intratumoral structure of small hyperechoic renal tumors, we recommend intraoperative pathological examination when CT findings do not correspond with the results of ultrasonography.

Adult↗

Synthesis of N-substituted C-normorphinans and their pharmacological properties.

Several N-substituted C-normorphinans (VIII and IX) were synthesized and tested for their analgetic and narcotic antagonist activities and physical dependence capacity. Treatment of N-formyl- octahydro-2-pyrindine (IIIc) with polyphosphoric acid readily gave N-formyl-C-normorphinan (IV). The N-nor bases (V and VII) obtained from IV were converted to VIII and IX. The N-methyl derivative (I), which was previously reported to be inactive by Haffner's method, exhibited potent analgetic activity by the hot plate method and the AcOH-induced writhing test. Compounds VIII and IX showed pharmacological properties similar to those of N-substituted morphinans and exhibited agonist (analgetic) and/or narcotic antagonist activities. The C-nor analogue (IXa) of cyclorphan (IIc) exhibited potent analgetic and antagonist activities with no physical dependence capacity in the single-dose suppression tests both in rats and monkeys.

Analgesics↗

Synthesis of the optically active trans-isomers of diltiazem and their cardiovascular effects and Ca-antagonistic activity.

Optically active trans-isomers of diltiazem were synthesized and their cardiovascular effects were evaluated in anesthetized dogs and in isolated guinea pig hearts. Both (+)-2 (2R,3S) and (-)-2 (2S,3R) were much less active than diltiazem (1, 2S,3S) with short duration of action. No substantial enantiomeric difference in activity was seen between them. Their Ca-antagonistic activities on Ca(2+)-induced contractions in K(+)-depolarized canine basilar arteries were also examined. Absolute stereochemistry of (+)-2 was determined to be 2R,3S by X-ray crystallographic analysis.

Animals↗

Thyrotoxicosis with low serum total T3 level in patients with destructive thyroiditis and non-thyroidal illness.

The serum total T3 level, evaluated in 687 patients with thyrotoxicosis diagnosed by an elevated serum free T4 level and suppressed serum TSH level, was found to be high in 98.1% and normal in 1.9% of 592 patients with Graves' hyperthyroidism, and high in 75.8%, normal in 21.1% and low in 3.2% of 95 patients with destructive thyroiditis. Non-thyroidal illness was found in about a third of the patients with thyrotoxicosis and a normal serum total T3 level. The serum total T3 level was low with elevated serum thyroglobulin and reverse T3 levels in three patients with severe non-thyroidal illness, in whom the thyroidal radioactive iodine uptake was suppressed and the thyrotoxicosis resolved spontaneously with a normalization of the serum total T3 level after recovery from the destructive thyroiditis and non-thyroidal illness. It is therefore concluded that thyrotoxicosis with a low serum total T3 level, partially due to associated non-thyroidal illness, is more frequently found in patients with destructive thyroiditis than in those with Graves' hyperthyroidism.

Adult↗

Femoral artery blood flow monitoring has distinct advantages for examining redistribution of blood flow in fetal acidosis.

Changes of blood flow in umbilical artery, carotid artery and femoral artery were examined during the progression of acidemia in fetal sheep by means of indwelling transit-time ultrasonic blood flow meters. Moreover, catecholamines in fetal blood were measured and its interrelation to the alteration in blood flow was examined. Gradually progressing fetal acidemia was induced by repeated cord compression. Umbilical blood flow showed a initial increase thereafter maintaining a plateau through the experiment, which seemed to be dependent on fetal arterial pressure. Carotid artery flow gradually increased until the arterial pH in fetal blood declined to 7.20 and remained at this level even though the acidemia further progressed. Femoral artery flow markedly decreased around fetal arterial blood pH 7.20 and its change correlated well with the plasma level of catecholamines. This change of femoral artery flow may be evaluated by examination of the flow index as well as flow volume. Redistribution of blood flow in the progression of fetal acidemia may be initiated at around fetal arterial pH 7.20 and can be detected by studying femoral artery flow.

Acidosis↗

Reversible primary hypothyroidism and elevated serum iodine level in patients with renal dysfunction.

Recovery of thyroid function in patients with both thyroid and renal dysfunction was studied. Among 245 patients with primary hypothyroidism (serum TSH greater than 10 mU/l), 36 had mild to severe renal dysfunction (serum urea nitrogen greater than 7.1 mmol/l and creatinine greater than 106 mumol/l). Of these 36 patients, recovery of the thyroid function after iodine restriction was observed in 30 (83%), in whom an elevated serum non-hormonal iodine level (median 236, range 67-15,591 micrograms/l, N = 19) and a high thyroidal radioactive iodine uptake (51.5 +/- 29.3% at 24 h, N = 26) were observed. The perchlorate discharge test was positive in 7 of 13 patients examined, suggesting an iodide organification defect rather than an atrophic or destructive change in the thyroid. Antithyroid antibodies were negative in 22 patients (73%) and an almost normal thyroid gland or colloid goitre was confirmed histologically in 8 of them. After a 13.2 mg potassium iodide loading test, 24 h urinary excretion of iodine was about 60% in normal controls, but only 10% in a different group of six euthyroid patients with renal dysfunction. These findings suggest that impaired renal handling of iodine rather than autoimmune mechanism may have a significant role in the pathogenesis of reversible hypothyroidism found in patients with renal dysfunction, probably through a prolonged Wolff-Chaikoff effect.

Adult↗

Pericentric inversion of chromosome 9 in prenatal diagnosis and infertility.

In order to evaluate the relation between pericentric inversion of chromosome 9 (inv(9)) and clinical problems, the characteristics of inv(9) were investigated on the basis of chromosomal analyses of fetuses and infertile couples. The incidence of such inversion in fetuses with parents having an offspring who suffered from various clinical problems was significantly higher than the basic incidence obtained in fetuses karyotyped by reason of advanced maternal age. In the chromosomal examination of the parents whose fetuses were diagnosed as inv(9), it was revealed that either parent might be the carrier. Furthermore, in the inv(9) carrying fetuses, the number of females was significantly greater than that of males. Analysis of infertile couples revealed that the incidence of such inversion in males was significantly higher than the basic incidence mentioned above. Moreover, infertile couples with an inv(9) carrier showed a significantly higher incidence of intrauterine fetal death, compared with infertile couples with a translocation carrier or those in which the etiology was unknown. These results indicate that inv(9) may often cause clinical problems in offspring of the carrier and infertility with unknown mechanisms related to sex.

Chromosome Aberrations↗

Relation between fetal blood gas levels and the outcome of babies in severe preeclampsia.

The purpose of this study is to ascertain that fetal blood gas values obtained by cordocentesis could be a clinical standard to decide whether or not we should terminate pregnancy and switch to exutero salvage for avoiding hypoxic damage. Fetal blood sampling was performed 38 times in 36 cases of severe preeclampsia. The relation between fetal blood gas values and the prognosis of the baby was statistically examined. Six of 36 fetuses of severe preeclampsia died prenatally or postnatally. There were significant differences in delta-values (difference from the normal mean value in each gestational week) of pO2, pCO2, and pH between survivors and non-survivors. delta pO2 value is most reliable to predict fetal prognosis. Since conventional fetal evaluation methods such as fetal heart rate monitoring are unreliable in the early gestational period, fetal gas evaluation is preferable to decide further intervention.

Blood Gas Analysis↗

Meningioma developed 25 years after radiation therapy for Cushing's disease.

A 44-year-old woman who had been therapeutically irradiated with 45 Gy to the sellar lesion for Cushing's disease has been in remission for 25 years. A large but asymptomatic brain tumor was accidentally found in the right middle fossa by a routine follow-up computed tomography. Upon surgical removal of the tumor, the histology revealed a fibroblastic meningioma. Although the incidence of meningioma following irradiation to pituitary adenoma is rare, a follow-up computed tomography should be taken to any possible late onset, and curable complication.

Adenoma↗

[Urodynamic findings in patients with a urethral Kock pouch after radical cystectomy].

Urodynamic evaluation was performed in 11 male patients, who underwent radical cystectomy with pelvic lymph node dissection for bladder cancer followed by bladder replacement with a urethral Kock pouch, 3 to 21 months after the operation. Frequency of micturition were 4.9 +/- 1.5 times (mean +/- S.D.) during the day-time and 1.5 +/- 1.2 times during the night-time. Tidal volume of micturition ranged from 300 to 550 ml and residual volume from 10 to 30 ml. Urinary continence was completely preserved in all patients (100%) during the day-time and 8 (72.7%) during the night-time. On pouchmetry, maximum capacity of the pouch was 429.2 +/- 82.4 ml, and intra-pouch pressure was 16.2 +/- 5.4 cmH2O at the capacity of 200 ml and 38.7 +/- 11.5 cmH2O at the maximum capacity. Maximum intra-pouch pressure on voiding was 80.0 +/- 19.4 cmH2O. Uroflowmetry demonstrated intermittent voiding curves in all the patients, with maximum flow rate of 15.2 +/- 6.5 ml/sec, voided volume of 405.9 +/- 80.7 ml and residual rate of 4.5 +/- 2.6%. Maximum intra-urethral pressure at the external urethral sphincter was 28.0 +/- 11.3 cmH2O when the pouch was empty and increased in response to pouch filling up to 64.7 +/- 27.0 cmH2O. Maximum urethral closing pressure and total profile length on the urethral pressure profile were 30.2 +/- 12.4 cmH2O and 20.9 +/- 9.0 mm, respectively, with the pouch empty, and 23.2 +/- 14.5 cmH2O and 20.0 +/- 7.6 mm, respectively, with the pouch full.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗