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Biomedical subjects

K Okamura

Publications and source records attributed to K Okamura.

At least 217 records · Page 12Linked to original sources
PubMed1994

Funipuncture for evaluation of hematologic and coagulation indices in the surviving twin following co-twin's death.

OBJECTIVE: To examine the changes in hematologic and coagulation indices in the surviving twin when the co-twin dies because of the twin-twin transfusion syndrome. METHODS: Fetal blood was obtained by funipuncture in seven surviving twins upon the death of their co-twins. Five of them were monochorionic. In one case at 32 weeks' gestation, two repeated funipunctures were done in both twins before and in the surviving twin after the death of the co-twin. Fetal blood was examined for blood coagulation factors as well as complete blood counts. RESULTS: Although coagulation factors were not abnormal, three of the five monochorionic surviving twins had cerebral abnormalities postnatally. The fetal blood profile revealed anemia in the surviving twin, especially in the cases in which funipunctures were performed within 24 hours after the co-twin's death. This demonstrates that acute anemia in the surviving twin was induced by hemorrhage from the larger to the smaller twin at the time of death. CONCLUSION: Following the death of one twin, morbidity in the surviving twin can be produced by hypotensive ischemia of the brain due to hemorrhage through placental vascular anastomoses.

Blood Coagulation↗
PubMed1994

Cytotoxicity of simvastatin to pancreatic adenocarcinoma cells containing mutant ras gene.

Simvastatin (SV), a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, inhibits the synthesis of mevalonic acid. The dose-dependent (0.1-100 micrograms/ml) cytotoxicity of SV towards human (MIAPaCa-2, Panc-1, HPC-1, HPC-3, HPC-4, PK-1, PK-9) and hamster (T2) pancreatic carcinoma cell lines was determined by MTT assay. At up to 20 micrograms/ml of SV, the effect was reversible and was restored by 60 micrograms/ml mevalonic acid. Point mutation of Ki-ras at codon 12 in each cell line was detected by means of the modified polymerase chain reaction. The concentration of SV necessary to achieve 50% cytotoxicity was about 10 micrograms/ml, and at this concentration of SV, DNA synthesis assayed in terms of [3H]thymidine uptake, isoprenylation of p21ras examined by Western blotting and cell progression from G1 to S phase of the cell cycle analyzed by flow cytometry were all inhibited. Isoprenylation inhibitors of p21ras, such as SV, are expected to be useful for the treatment of pancreatic cancer.

Adenocarcinoma↗
PubMed1994

Immunological characterization of human decidual mononuclear cells: natural killer activity, response to interleukin-2 and distribution of interleukin-2 receptor subunits.

We investigated the immunological character of mononuclear cells obtained from the decidua in the first trimester of normal pregnancy. These cells showed in vitro cytotoxicity against NK cell targets, although with lower activity than that of the peripheral blood mononuclear cells. Response to IL-2 was dose-dependent. Since decidual CD56-positive cells express two IL-2 receptor subunits, p55 and p75, it is concluded that these cells have high-affinity receptors to IL-2. Peripheral blood CD56-positive cells, which express p75 alone, might have intermediate-affinity IL-2 receptors. These results indicate that the decidual mononuclear cells have a function resembling that of the peripheral blood NK cells in vitro, moreover, that even low levels of IL-2 can affect the character of the decidual mononuclear cells through the high-affinity IL-2 receptor. It is considered that the NK activity of decidual mononuclear cells is suppressed in conditions of low IL-2 levels to permit the maintenance of pregnancy, but can be rapidly elicited by intrauterine infections or abortion, both of which elicit the secretion of IL-2.

Cytotoxicity, Immunologic↗
PubMed1994

Cloning of the macrolide antibiotic biosynthesis gene acyA, which encodes 3-O-acyltransferase, from Streptomyces thermotolerans and its use for direct fermentative production of a hybrid macrolide antibiotic.

A gene encoding the macrolide modification enzyme 3-O-acyltransferase (acyA) was cloned by chromosome walking onto the carbomycin biosynthetic region in Streptomyces thermotolerans TH475, with the 3' region of the gene encoding the macrolide modification enzyme 4"-O-acyltransferase (acyB1) as a probe. A shortened fragment (1.8 kb) containing acyA was subcloned with pIJ350. A high-level tylosin producer, Streptomyces fradiae MBBF, transformed with the plasmid could produce a hybrid macrolide, 3-O-acetyltylosin, most efficiently.

Acyltransferases↗
PubMed1994

The frequency of human parvovirus B19 infection in nonimmune hydrops fetalis.

Intrauterine infection of human parvovirus B19 has recently been identified as an etiology for nonimmune hydrops fetalis (NIHF) and fetal death. To examine the frequency of B19 infection in cases of NIHF, forty two cases of NIHF of unknown cause were tested for the presence of B19 antibodies by enzyme-linked immunosorbent assay (ELISA) and B19 DNA by polymerase chain reaction (PCR). Three maternal sera were positive for B19 IgM antibody and one fetal serum was positive for B19 DNA. Overall, four (10%) of the 42 cases were positive for B19 infection. All of the four cases positive for B19 infection were found during or just before an outbreak of erythema infectiosum and the incidence was calculated at 36% if only cases found during the outbreak were collected. In all four cases of B19 infection, NIHF was diagnosed at 20 to 23 weeks of gestation, which suggested that B19 infection might be a particular threat to the fetus during this stage of gestation. In conclusion, B19 infection may contribute to 10% of cause unknown NIHF and the incidence may be higher if cases during outbreaks are exclusively collected.

Antibodies, Viral↗
PubMed1994

Primary hypothyroidism manifested in childhood with special reference to various types of reversible hypothyroidism.

The clinical course of 15 patients with overt primary hypothyroidism manifested in childhood were studied. Nine female patients with goitrous hypothyroidism due to chronic thyroiditis showed almost normal height and became euthyroid spontaneously during iodine restriction. The other 6 nongoitrous patients (3M and 3F) (atrophic thyroiditis in 2, lingual goiter in 2 and probable hypoplastic thyroid in 2) showed physical growth retardation and remained irreversibly hypothyroid requiring replacement therapy. In the reversible group, the characteristic findings were high thyroidal radioactive iodine uptake (58 +/- 19%/24 h, N = 8) and positive perchlorate discharge test. Serum nonhormonal iodine levels were high in 4 of 6 patients measured. During the long-term follow-up period of 6 years in 6 patients, 2 patients remained euthyroid with normal growth and regular menstrual cycle and 4 patients became hypothyroid again (after eating seaweed in 1, despite iodine restriction in 2 and after the episode of painless thyroiditis in 1). Transient retardation of growth was observed during the second episode of hypothyroidism. In the irreversible group, one patient with blocking type TSH binding inhibitor immunoglobulin (TBII) became thyrotoxic 4 years later with the decrease in activity of blocking type TBII. These results suggested that reversible recovery of the thyroid function could be expected in patients with juvenile hypothyroidism due to chronic thyroiditis after (1) iodine restriction, (2) improvement of immunological perturbation, or (3) disappearance of blocking type TBII. However, careful follow-up is necessary, because hypothyroidism would recur again with transient retardation of growth in children.

Adolescent↗
PubMed1994

Postpartum exacerbation of HTLV-I associated myelopathy/tropical spastic paraparesis followed by an episode of painless thyroiditis.

A 28-year-old woman noticed a progressive gait disturbance after her first delivery. At the age of 32, the gait disturbance improved during her second pregnancy, but became worse after delivery and eventually resulted in a scissoring gait. At the age of 34, she became transiently thyrotoxic and was diagnosed as having painless thyroiditis and HTLV-I associated myelopathy/tropical spastic paraparesis (HAM/TSP). The findings of this case suggest that the postpartum exacerbation of HAM/TSP was probably due to a rebound phenomenon after immunosuppression during pregnancy, and that the immunological abnormalities associated with HAM/TSP might have played some role in the development of painless thyroiditis.

Adult↗
PubMed1994

Modulation of circadian rhythm of blood pressure by cortisol in patients with hypopituitarism.

We conducted a study to determine the effect of exogenous cortisol on circadian blood pressure changes in patients with hypopituitarism. Under replacement with hydrocortisone of 15 to 25mg either once (8:00) or twice a day (8:00 and 20:00), and with prednisolone of 3.75 to 5mg once a day, the patients underwent non-invasive ambulatory blood pressure monitoring for 24 hours. The average 24-hour blood pressure before hydrocortisone replacement was 92.9 +/- 1.0 (systolic)/53.2 +/- 0.8mmHg (diastolic), while that after hydrocortisone replacement once or twice a day and prednisolone replacement significantly increased to 108.2 +/- 1.4/63.5 +/- 0.9mmHg, 109.1 +/- 1.6/62.3 +/- 1.0mmHg, and 105.4 +/- 1.2/62.3 +/- 0.9mmHg, respectively. Hydrocortisone replacement once a day showed a significant increase in day-night differences of blood pressure, while hydrocortisone replacement twice a day did not. There were no differences in nocturnal decrease in pulse rate between these two replacements. The daytime and nighttime urinary excretions of 17-hydroxycorticosteroids in hydrocortisone replacement once a day were 7.7mg/12hr (daytime) and 1.4mg/12hr (nighttime), respectively, while those in hydrocortisone replacement twice a day were 3.9mg/12hr (daytime) and 3.6mg/12hr (nighttime), respectively. Urinary 17-ketosteroids, epinephrine and norepinephrine did not show any differences between hydrocortisone replacement once and twice a day. These results suggest that hydrocortisone administration is one of the factors which modulate the circadian variation of blood pressure in patients with hypopituitarism, and may also suggest that the circadian change of cortisol secretion participates, at least in part, in the formation of an intrinsic circadian rhythm of blood pressure.

Blood Pressure↗
PubMed1994

Effects of lysosomal protease inhibitors on the degradation of acetylated low density lipoprotein in cultured rat peritoneal macrophages.

The effect of protease inhibitors, leupeptin and pepstatin A, on the metabolism of acetylated low density lipoprotein (acetyl-LDL) was investigated in cultured rat peritoneal macrophages and compared with that of chloroquine. While both leupeptin and pepstatin inhibited the proteolytic degradation of 125I-acetyl-LDL, a combination of both showed an additive effect. Similar to chloroquine, both protease inhibitors diminished [3H] oleate incorporation into cellular cholesteryl[3H] oleate and increased cholesterol content of macrophages. These results suggest that both thiol protease and cathepsin D participate in the physiological degradation of apolipoprotein in macrophages. The inhibition of apolipoprotein degradation seemed to have an effect on cholesterol metabolism in macrophages cultured with acetyl-LDL.

Acetylation↗
PubMed1994

[Trigonoplasty for vesicoureteral reflux--from open surgery to endoscopic surgery].

To evaluate endoscopic trigonoplasty compared to open trigonoplasty for vesicoureteral reflux, we analyzed clinical results, complications, the use of analgesics for postoperative pain and bladder irritability and postoperative length of hospitalization. One of six patients undergoing endoscopic trigonoplasty subsequently underwent open trigonoplasty due to failure of trocar placement, therefore, 7 patients having vesicoureteral refluxy renoureteral units underwent open trigonoplasty and 5 patients with vesicoureteral reflux 7 renoureteral units underwent endoscopic trigonoplasty. Mean operative time was 143 +/- 48 minutes for open surgery and 185 +/- 54 minutes for endoscopic surgery. Vesicoureteral reflux disappeared in 8 renoureteral units but was worse in one unit after open trigonoplasty, while vesicoureteral reflux subsided in 6 units and improved in one unit from grade II to grade I after endoscopic trigonoplasty. There were no intraoperative complications after open surgery, while one patient had pneumoperitoneum due to inadequate placement of a trocar during endoscopic surgery. There were no early postoperative complications after endoscopic surgery. However, 2 patients developed hematuria after open surgery. The degree of postoperative pain and irritability following endoscopic trigonoplasty was lower than that after open trigonoplasty and analgesics were used less frequently after endoscopic surgery. The mean postoperative hospital stay was 16.7 +/- 3.2 days for open surgery and 14.4 +/- 2.9 days for endoscopic surgery. These results indicate that endoscopic trigonoplasty is a useful procedure for vesicoureteral reflux because it is minimally invasive.

Adolescent↗
PubMed1994

[Biochemical analysis of the external striated urethral sphincter of male rabbits. Difference in the proportions of muscle fiber types in the male rabbit external urethral sphincter by axial subdivisional study].

We studied the difference in the proportion of fast and slow myosin subunits in axially subdivided external urethral sphincter of male rabbit using myosin light chain and heavy chain analyses. The whole urethras from 6 adult male Japanese White rabbits were sagittally bisected and one halves from all animals were processed for myosin light chain analysis and another halves from all animals for myosin heavy chain analysis. Each half urethra containing the external urethral sphincter was subdivided into 4 parts, namely prostatic (P), prostatic apical (PA), infraprostatic (IP) and bullbourethral glandular (BUG) portions, from cranial to caudal direction. The electrophoretic samples from 4 different parts were separately processed. The external urethral sphincter muscle in each part from all animals were processed together for a sample because of the minute amount of the muscle. Two-dimensional electrophoresis according to the procedure of O'Farrell for myosin light chains and SDS-polyacrylamide gel electrophoresis containing 40% glycerol for myosin heavy chains were carried out. Molar ratio of myosin subunits were estimated by the dye elution procedure. The relative proportions of slow myosin molecules in respective parts were 33.4% (P), 26.3% (PA), 18.5% (IP) and 11.0% (BUG) from myosin light chain analysis and 20.3% (P), 16.1% (PA), 7.2% (IP) and 5.0% (BUG) from myosin heavy chain analysis. The urethral striated musculature in male rabbit was predominantly composed of fast myosin subunits as a whole. But the proportion of slow myosin subunits occupied a relatively high percentage in the proximal region and tended to decrease toward the distal end.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

[Results of treatment for advanced non-seminomatous germ cell tumors of the testis based on Indiana University classification].

From 1980 to 1990, we treated 45 patients with non-seminomatous germ cell tumors of greater than or equal to stage II according to the Japanese general rule for clinical and pathological studies on testicular tumors. The patients were divided into 2 groups based on the Indiana University Classification: 26 good risk patients (score < or = 6) and 19 poor risk patients (score > or = 7). The clinical results, the % dose intensity of Cisplatin and half-lives of tumor makers were analyzed in the two groups. The per cent dose intensity of Cisplatin of the induction chemotherapy was 61 +/- 24% in 1980-1985 and 87 +/- 18% in 1986-1990. The NED rate improved from 66.7% (10/15) to 81.8% (9/11) in the good risk patients and from 33.3% (3/9) to 50.0% (5/10) in the poor risk patients between the above two periods. When the % dose intensity of Cisplatin exceeded 80%, the NED rate increased from 66.7% (10/15) to 90.0% (9/10) in good risk patients and from 33.3% (2/6) to 45.5% (5/11) in poor risk patients. The NED rate was only 25.0% (4/16) in the poor risk patients whose residual tumors were not resected. The half-lives of AFP and beta-HCG from the latter part of the first course to the second course were 6.8 +/- 1.9 days and 4.4 +/- 1.4 days, respectively, in the patients with a good prognosis, while they were 6.5 +/- 1.5 days and 4.4 +/- 2.9 days, respectively, in with a poor prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

[Clinical analysis of methicillin-resistant Staphylococcus aureus (MRSA) infection].

In 14 patients from which methicillin-resistant Staphylococcus aureus (MRSA) was isolated at the Department of Urology, Tone Chuo Hospital June, 1992 and October, 1993, the site of infection, background of patients, and drug resistance were analyzed. The 14 patients consisted of 11 males and 3 females between 45 and 85 years old with a mean of 71.6 years. The site from which MRSA was isolated was urine in 11, wound in 2, nasal cavity in 1, pharynx in 1, and renal fistula in 1 (detected at 2 or more sites in 2). The underlying condition was prostate hyperplasia in 2, prostate cancer in 4 (after radical prostatectomy in 1, complicated by bladder stone in 1), bladder tumor in 3, (during bladder instillation of BCG in 1), perirenal abscess in 2, renal pelvic tumor in 1, neurogenic bladder in 1, and after Boari's operation in 1. Urethral catheterization had been performed in 3. A fewer of 38 degrees C or above was noted in 3. Mixed infection was observed in 10, and was caused by Escherichia coli in 2, Proteus mirabiris in 1, Candida in 1, Klebsiella in 2, Pseudomonas aeruginosa in 2, and Serratia in 2. Four patients has previously been administered antibiotics, which were third generation cephems in 3 and penicillin in 1. The drug sensitivity was 100% for vancomycin (VCM), 30% for imipenam (IMP), 31% for minomycin (MINO), 31% for amikacin (AMK), and 7% for fosfomycin (FOM). As for chemotherapy, VCM+FOM+sulbactam/cefoperazone were administered to 6, and ceftazidime+ MINO were administered to 1.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

[Marked effectiveness of the LH-RH analogue in a case of prostate cancer with large lymph node metastasis].

A 78-year-old man visited our hospital complaining of pollakisuria, dysuria, and edema of lower extremities. Physical examination revealed a hard, fixed and fist size mass in the abdomen Lymph nodes of left supraclavicular fossa were hardly palpable. His prostate was larger than a hen's egg, stony hard and fixed in the pelvis on digital rectal examination (DRE). The prostate specific antigen (PSA) level was elevated to 584 ng/ml. Computerized tomography (CT) revealed enlarged retroperitoneal lymph nodes. Bone scan showed multiple abnormal uptake. Prostate biopsy showed poorly differentiated adenocarcinoma. Treatment with the LH-RH analogue was very effective. The retroperitoneal lymph nodes were no longer enlarged on CT. The prostate had become soft and was reduced to walnut size on DRE. The PSA level had decreased to within the normal range. The multiple abnormal uptake on the bone scan decreased. This is the 21st case of prostate cancer with large lymph node metastasis in Japan.

Adenocarcinoma↗
PubMed1994

[Influence of ionized calcium concentration during cardiopulmonary bypass on pediatric cardiac surgery].

Changes of serum ionized calcium concentration (Ca2+) during cardiopulmonary bypass (CPB) were analyzed in 30 pediatric cardiac patients less than 15 kg body weight. Ca2+ decreased suddenly after the start of CPB, and it gradually increased to the normal value. Citrate added to the stored blood for priming and its metabolism might play a role in these changes of Ca2+. Addition of adequate volume of calcium chloride to the priming prevented sudden decrease of Ca2+. Although addition of citrate before aortic declamp effectively decreased Ca2+ and may prevent reperfusion cardiac injury associated with hypercalcemia, there were no correlation between predeclamp level of Ca2+ and serum CPK and GOT levels.

Body Weight↗
PubMed1994

[Point mutation of T3 receptor-beta gene and syndrome of inappropriate secretion of TSH].

Thyroid hormone receptors (TRs) are bound to the T3-responsive element of DNA as dimers and heterodimerization with TR-auxiliary protein (TRAP) strongly enhances this binding. In affected members of families with the thyroid hormone resistance syndrome, significant point mutations have been identified in the hormone-binding domain of one of the two alleles of the TR beta gene, especially in two "hot spot" regions, avoiding the regions required for DNA binding, dimerization or binding to TRAP. These findings suggested that DNA-binding and receptor dimerization are important for dominant negative inhibition by the mutant TR, which is responsible for thyroid hormone resistance in a heterozygous patient with a point mutation in the TR beta gene.

DNA↗