Percutaneous radio-frequency ablation of the thyroid guided by ultrasonography.
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Animals↗
Biomedical subjects
Y Mimura
Publications and source records attributed to Y Mimura.
Gender differences in cytokine secretion by human peripheral blood mononuclear cells: role of estrogen in modulating LPS-induced cytokine secretion in an ex vivo septic model.
Clinical studies demonstrate a better outcome of sepsis in females. Elevated estrogen levels and plasma cytokine imbalance occur in septic patients. We propose that gender-different cytokine secretion by the peripheral blood mononuclear cells (PBMCs) in sepsis determines the clinical outcome. A 2 x 10(6) PBMC sample from healthy volunteers (10 males and 10 females) was incubated with 1 ng/mL of lipopolysaccharide (LPS), estradiol (E2; 0, 0.03, 0.3, 3.0, 30 ng/mL), or 1 ng/mL of LPS + E2 (0, 0.03, 0.3, 3.0, 30 ng/ml), and supernatant cytokine levels were measured. Tumor necrosis factor alpha (TNF alpha) and interleukin (IL)-6 production by PBMCs from both sexes was time-dependently stimulated by LPS. At 6 h after LPS challenge, the TNF alpha level of male PBMCs was significantly higher but IL-6 secretion by female PBMCs was higher (two-way ANOVA: P < 0.05). E2 alone stimulated cytokine secretion by male PBMCs. Addition of the same E2 concentration as in sepsis patients' plasma modulated LPS-induced cytokine production. No significant sex differences in LPS-stimulated TNF alpha or IL-6 secretion by PBMCs were found, but IL-10 secretion by male PBMCs was significantly suppressed. This study demonstrated a gender difference in PBMCs responsiveness to LPS and E2 stimulation and E2-modulated cytokine secretion. In this PBMCs model of sepsis, only the supernatant IL-10 level was significantly lower in males. These ex vivo findings may partially explain the mechanism underlying the poorer outcome of male sepsis patients.
Adult↗
Japanese family with glucocorticoid-remediable aldosteronism diagnosed by long-polymerase chain reaction.
We report a Japanese family with glucocorticoid-remediable aldosteronism (GRA) in whom gene abnormality was identified by the long-polymerase chain reaction (PCR) method. The proband was a 21-year-old female incidentally found to have high blood pressure (173/107 mmHg). Laboratory tests showed hypokalemia (3.7 mmol/l), and high plasma aldosterone concentration (PAC, 234 pg/ml) with suppressed plasma renin activity (PRA, <0.1 ng/ml/h). The circadian rhythm pattern and the results of a rapid adrenocorticotrophic hormone (ACTH) test indicated ACTH-dependent changes in PAC. Imaging studies showed no adrenal mass on either side. A dexamethasone (Dexa) suppression test (1.0 mg/day orally for 7 days) showed a marked decrease of PAC 2 days after administration, and this decreased level was maintained throughout Dexa administration. High blood pressure and hypokalemia also improved during Dexa treatment. The proband's younger sister was 19 years old and had hypertension, PAC of 231 pg/ml, and PRA <0.1 ng/ml/h. The mother was 53 years old and had hypertension, PAC of 98.5 pg/ml, and PRA <0.1 ng/ml/h. The proband's elder sister was a 22-year-old normotensive with PAC of 110 pg/ml and PRA of 0.1 ng/ml. Long-PCR was performed for detection of the chimeric gene associated with GRA, using DNA samples from all four cases and two normal control subjects. Although the aldosterone synthase gene was expressed among all DNA samples, the chimeric gene was detected only in the proband, her younger sister and her mother. Our clinical data and genetic investigation confirmed the presence of GRA in this Japanese family.
Adult↗
Coexistence of Graves' disease and struma ovarii: case report and literature review.
We report a rare case of Graves' disease associated with struma ovarii. A 26-year-old Japanese woman had preexisting Graves' disease and was positive for TSH receptor antibody. She had been on antithyroid medication at presentation. She noted a mass in the lower left abdomen, which was diagnosed as a left struma ovarii by radiological work-up including computed tomography, magnetic resonance imaging and scintigraphy. The surgically excised teratomatous tumor, containing cystic spaces with thyroid tissue, was histologically proved to be struma ovarii. Since thyroid function tests and TSH receptor antibody did not change after surgery, her hyperthyroidism was considered to be due to Graves' disease. Our case was diagnosed as struma ovarii before surgery using various imaging studies.
Adult↗
Pathophysiological relevance of the CD14 receptor in surgical patients: biological activity of endotoxin is regulated by the CD14 receptor.
Endotoxins (lipopolysaccharides, LPSs) are potent bacterial poisons, and they are always present in the intestine in considerable numbers. Stress, such that as a resulting from multiple injuries, burns, hypovolemia, hypoxia, intestinal ischemia, and surgery can lead to a breakdown of the gut barrier, allowing endotoxins to enter the systemic circulation via translocation. However, estimating the biological activity of translocated circulating endotoxins and identification of the mechanisms regulating their biological activities remain complex problems. CD14 has been found to exist as a soluble protein in the serum and as a glycosylphosphatidylinositol (GPI)-anchored protein of myeloid lineage cells. It plays key roles in both LPS-induced activation and in LPS internalization by cells. In this article, we outline: (i) the biological activity of circulating endotoxin; and (ii) the role of membrane and/or soluble CD14 regulating the bioactivity of circulating endotoxin in a human model of postoperative endotoxemia.
Anti-Bacterial Agents↗
Telomerase activity and telomere length in benign and malignant human thyroid tissues.
Several studies have demonstrated that telomerase is activated and telomere length is altered in various types of tumors. In this study, we investigated telomerase activities and telomere length in 21 thyroid tumors. Telomerase activity was detected in 11 of 12 thyroid cancers and three of nine follicular adenomas. The mean telomere lengths in the cancers tissue and follicular adenomas were lower than in the respective background tissues, the differences being significant (P=0.0055 and P<0.006), respectively. Our findings suggest that change in telomerase activity and telomere length may be important for development of thyroid tumors.
Adenoma↗
Testosterone modulates serum leptin concentrations in a male patient with hypothalamic hypogonadism.
Serial measurements of body mass index (BMI), serum concentrations of testosterone (T), estradiol (E) and leptin (L) were performed before and after gonadotropin (Gn) therapy in an 18-year-old male subject (BMI 25.4 kg/m2) with idiopathic hypothalamic hypogonadism (IHH). We also measured the BMI and serum concentrations of L in 99 age-matched healthy subjects. Serum L correlated significantly with BMI in control subjects (r=0.84, p<0.0001). Baseline serum concentrations of L in our case were markedly high and both T and E were very low, but Gn therapy resulted in a gradual decrease in L and improvement in T and E, finally reaching the control levels of BMI-matched subjects. Our results demonstrate that T is a powerful negative modulator of serum L independent of BMI in conditions associated with low T levels, such as IHH.
Adolescent↗
Release of endotoxin-binding proteins during major elective surgery: role of soluble CD14 in phagocytic activation.
Our previous study demonstrated that soluble CD14 (sCD14) modulates the biologic activity of circulating endotoxin, which appears after surgery. In this study, we examined the behavior of endotoxin-binding proteins, such as sCD14, lipopolysaccharide-binding protein (LBP), and bactericidal/permeability-increasing protein (BPI), in patients' plasma after major abdominal surgery and the phagocytic secretion of sCD14 from peripheral blood mononuclear cells (PBMCs) throughout the observation period. In a prospective study, 15 patients undergoing major abdominal surgery (gastrectomy, n = 3; pancreatectomy, n = 10: colectomy, n = 2) were involved in this study. The endotoxin-binding proteins were perioperatively (preoperatively; postoperative hour 6; days 1, 2, 3, 4, 5, 7, and 10) measured by an enzyme-linked immunosorbent assay (ELISA). To exclude the hemodilution effect of samples, each parameter was corrected by dividing the respective value by the albumin concentration. The phagocytic activity at each time point was tested as an ex vivo sCD14 secretion from PBMCs in the presence and absence of exogenously added endotoxin, Escherichia coli 055B5 (1 ng/ml). Significant endotoxemia (0.35 +/- 0.13 EU/ml; p < 0.05) was observed 6 hours after the beginning of surgery. The sCD14/albumin value rapidly increased at 6 hours after surgery, peaked on day 1, and sequentially declined, whereas the BPI/albumin and LBP/albumin ratios increased more gradually and peaked on day 2. The secretion of sCD14 from 2 x 10(6) PBMCs was significantly enhanced from 6 hours after operation. The increased plasma level of sCD14 may be explained by the parallel-enhanced sCD14 PBMC production. Activated secretion of these endotoxin-binding proteins may play a role in regulating the biologic activity of circulating endotoxin.
Acute-Phase Proteins↗
Review of 41 patients operated on for primary hyperparathyroidism.
We reviewed 41 cases of operation for primary hyperparathyroidism (PHPT) in our institution between 1987 and 1999. The objective of this study was 1) to evaluate the sensitivity and positive predictive value of several localization studies for an enlarged parathyroid gland; 2) to determine whether a selective. unilateral-exploration operation is safe; and 3) to investigate rates of coexisting malignancies of other organs. A total of 61 enlarged parathyroid glands (701 +/- 131 mg wt) were removed, and the lesions consisted of 32 adenomas, two cancers, and seven hyperplasias. MIBI scintigraphy had both a high sensitivity (88.9%) and positive predictive value (88.9%) for localization of abnormal parathyroid glands and yielded better performance than the other techniques, including ultrasonography, CT scanning, and Tl-Tc scintigraphy. However, all of the localization techniques failed to detect enlarged glands (18/32 glands = 62.5%) in patients with multi-glandular parathyroid lesions. Initial operations with selective unilateral exploration of the neck were successful in 23 of 24 patients (95.8%). Operative failure was due to missing the second adenoma of a double adenoma. Malignant tumors were found in 11 patients (26.8%) previously treated or concurrently managed at the time of parathyroidectomy. There was a significant increase in serum-intact PTH level in patients with concurrent malignant tumors compared to patients who had no association of malignancies. In conclusion, 1) at least two preoperative localization tests, an MIBI scan and ultrasonography, are helpful in accurately localizing an abnormal parathyroid gland; 2) selective unilateral exploration is safe and desirable if the second ipsilateral gland is normal macroscopically; and 3) systematic examination for malignant tumors is necessary in PHPT patients before and after parathyroidectomy.
Aged↗
Catecholamine and cytokine response to laparoscopic adrenalectomy in patients with pheochromocytoma.
This study assesses the surgical stress of laparoscopic adrenalectomy (LA) in patients with pheochromocytoma using catecholamine and cytokine. The study was conducted on one patient who had laparoscopic adrenalectomy performed for pheochromocytoma, and three patients as controls who had undergone laparoscopic cholecystectomy (LC) for cholecystolithiasis. Catecholamines, tumor necrosis factor alpha (TNFalpha) and interleukin 6 (IL-6) were measured at 30-minute intervals intraoperatively, and on the first, third and fifth postoperative days (POD) respectively. Plasma TNFalpha and IL-6 were measured by a commercially available sandwich enzyme-linked immunosorbent assay test. During the operation. changes of catecholamine concentration in LA were far larger than those in LC. The changes of TNFalpha concentration in LA were also larger than those in LC. TNFalpha returned to basal value at the end of the operation in LC, but it did not in LA. TNFalpha concentration in LC changed a little after the surgery, whereas that in LA sharply increased and was maintained at a high level from 1 POD until 5 POD. Enhanced cytokine responses were observed in LA compared to LC during and after the surgery. We concluded that laparoscopic adrenalectomy may give those patients with pheochromocytoma more surgical stress than laparoscopic cholecystectomy for cholecystolithiasis, during and after the operation.
Adrenal Gland Neoplasms↗
Differential effect of chronic inhibition of calcium channel and angiotensin II type 1-receptor on aldosterone synthesis in spontaneously hypertensive rats.
We have investigated the in vivo effect of chronic blockade of Ca(2+)-channels and angiotensin II type 1 (AT(1))-receptors on aldosterone (Aldo)-synthesis in the adrenal glands of spontaneously hypertensive rats (SHR). Male SHR were administered Ca(2+)-antagonist, amlodipine (10 mg/kg per day) or AT(1)-receptor-antagonist, TCV-116 (1 mg/kg per day) from 7 until 11 weeks of age. Systolic blood pressure (SBP) and heart rate (HR) were significantly higher in SHR than Wistar-Kyoto (WKY) rats. Both treatments resulted in equivalent and significant reduction in SBP in SHR. Aldo-secretion in SHR, which was significantly higher than in WKY rats, was profoundly suppressed by TCV-116 compared with amlodipine. Both treatments resulted in thickening of the zona glomerulosa, which immunohistochemically contains Aldo, at the end of therapy. Competitive reverse transcription-polymerase chain reaction (RT-PCR) showed that CYP11A (P450scc) mRNA regulating the first step of Aldo-synthesis was significantly reduced from week 9 of age by amlodipine, and that CYP11B2 (P450aldo) mRNA regulating the last step of Aldo-synthesis was potently suppressed from 9 weeks of age by TCV-116. Our results indicate that chronic treatment with different antihypertensive agents directly modulates adrenocortical aldosterone synthesis in SHR in vivo via different mechanisms.
Adrenal Cortex↗
Ischaemic preconditioning ameliorates functional disturbance and impaired renal perfusion in rat ischaemia-reperfused kidneys.
1. The effects of ischaemic preconditioning (IP) on renal function, haemodynamics and lipid peroxidation in the rat ischaemia-reperfused kidney model were examined. 2. In Wistar male rats, application of a single or three periods of 5 min bilateral renal ischaemia was performed prior to 30 min bilateral ischaemia and 90 min reperfusion (IR). The glomerular filtration rate (GFR) was estimated in terms of inulin clearance. Fractional excretion of sodium (FE(Na)) and lithium (FE(Li)), indicating total and proximal tubular sodium handling, respectively, was also measured and renal blood flow was monitored throughout the experiment. In addition, renal lipid peroxidation (LPO) levels in reperfused kidneys were evaluated. 3. A 2.8-fold increase in recovery of GFR (P < 0.005), a 50% reduction in FE(Na) (P < 0.005) and a 40% decrease in FE(Li) (P < 0.05) after IR resulted from the single period of 5 min IP. Renal blood flow was also higher than that in the control group (P < 0.01). No change of LPO levels was observed. 4. We conclude that IP may have an ability to ameliorate reperfused renal function and haemodynamics with a suitable period of preconditioned ischaemia, although this effect is independent of LPO.
Animals↗
Hyperthyroidism in a patient with TSH-producing pituitary adenoma coexisting with thyroid papillary adenocarcinoma.
A 27-year-old woman who presented with a left thyroid nodule was found to have hyperthyroidism caused by a syndrome of inappropriate secretion of TSH. The levels of free T3, free T4 and TSH were 9.50 pg/mL, 4.05 ng/dL and 2.16 microU/mL, respectively. Magnetic resonance imaging of the head revealed a pituitary macroadenoma. The TSH response to TRH stimulation was normal and responses of other anterior pituitary hormones to stimulation tests were also normally preserved. Administration of octreotide with iodine successfully reversed hyperthyroidism prior to total resection of pituitary adenoma, which was followed by hemithyroidectomy of the left thyroid five months later. Histologically, the resected pituitary adenoma was a TSH-producing adenoma (TSH-oma) and the thyroid nodule was a papillary adenocarcinoma. Serum TSH diminished to undetectable levels immediately following pituitary adenomectomy but gradually normalized over nine months. Coexistence of a TSH-oma with thyroid cancer is very rare and only two similar cases have previously been documented. This combination raises the possibility that TSH may be involved in tumorigenesis in the thyroid gland.
Adenocarcinoma, Papillary↗
The usefulness of rabbits as an animal model for the neuropathological assessment of neurotoxicity following the administration of vincristine.
Vincristine is an effective chemotherapeutic agent for a variety of human neoplasms, but has dose-limiting neurotoxicity. Since laboratory rodents have proven to be refractive in such neurotoxicological studies, we conducted a neuropathological and behavioral assessment in rabbits treated with vincristine at doses known to be both chemotherapeutically effective and neurotoxic in humans. Rabbits (Kbl: NZW) were given vincristine intravenously at doses of 0 (saline), 200, 250 or 300 microg/kg once a week for 6 weeks, 500 microg/kg once a week for 3 weeks, or a single 500 microg/kg administration. Detailed periodic neurologic examination revealed ataxia in a few animals. Pathologically, axonal injury progressing to fiber degeneration was observed in sensory tracts such as the posterior spinocerebellar tract and posterior funiculus, and in peripheral nerves after treatment with vincristine. These alterations were observed even after a single dose of 500 microg/kg. In the group given weekly doses of 500 microg/kg, neuronal chromatolysis was also found in the spinal cord. These results suggest the rabbit is responsive to vincristine neurotoxicity producing a predominantly sensory neuropathy and confirming earlier studies.
Animals↗
Schedule dependency of paclitaxel-induced neuropathy in mice: a morphological study.
Paclitaxel, which is known to induce peripheral neuropathy in humans, was administered to BDF1 mice, and a neuropathological examination was then conducted. Paclitaxel was administered at a dose of 30 mg/kg once or several times at different intervals, 3 times, every 3 hours (q3hx3), every day (q1dx3), every 2 days (q2dx3) and 4 times, once a week (q7dx4). The spinal cord, spinal ganglion and peripheral nerves (sciatic and tibial) were then processed for neuropathological examination following perfusion of the anesthetized mice. The effect on the peripheral nerves was evaluated by counting the number of abnormal nerve fibers in the preparations of teased nerve fibers and in the epoxy resin 1-microm-thick sections. The drug-induced degeneration, such as axonal and myelin fragmentations and phagocytosis in the nerve fibers, was detected in the dorsal funiculus, the dorsal spinal roots and the peripheral nerves (sciatic and tibial). No drug-related degeneration was observed in the motor neurons in the spinal cord nor in the ventral spinal roots. The single treatment did not induce any changes. The severity of the degeneration was as follows: q2dx3>q1dx3>>q3hx3 and q7dx4. The degeneration in the mice treated on q3hx3 and q7dx4 was very slight, but it was clear that paclitaxel also induced degeneration on these schedules. These results suggest that paclitaxel induces a predominantly sensory neuropathy in mice and the severity is obviously dependent on the treatment schedule.
Action Potentials↗
Serum leptin correlates with serum uric acid but not serum testosterone in non-obese male adolescents.
To identify the serum factors that affect circulating leptin levels, we measured the serum concentrations of leptin, testosterone (T), estradiol (E), serum alanine aminotransferase, total cholesterol and uric acid (UA) in healthy male adolescents (age, 18.3 +/- 0.1 years, n=96). We also measured body mass index (BMI), percent body fat and thickness of skin fold to assess the effect of body constitution on serum leptin level. Since serum concentration of leptin significantly correlated with BMI (r=0.820, p<0.001), we analyzed the relation-ship between leptin/BMI ratio (L/BMI) and serum parameters. Analysis of data of subjects with normal serum T level showed a significant inverse correlation between L/BMI and serum T levels (n=96, r=-0.294, p<0.005), but no such correlation was present among non-obese subjects (n=70) with BMI of +/-20% of normal (22 kg/m2). There was no correlation between L/BMI and serum E level. Serum UA level significantly correlated with L/BMI in both the test group (n=96, r=0.520, p<0.001) and non-obese subjects (r=0.369, p<0.005). Stepwise multiple regression analysis showed that UA independently and significantly influenced serum leptin levels in both the test and control groups. Our results demonstrate that T weakly influences serum leptin concentration, and that UA concentrations strongly influences serum leptin in healthy male adolescents independent of their obesity level.
Adolescent↗
Long-term administration of adrenocorticotropin modulates the expression of IGF-I and TGF-beta 1 mRNAs in the rat adrenal cortex.
The effects of long-term adrenocorticotropin (ACTH) therapy on the expression of IGF-I and TGF-beta 1 on rat adrenal cortex was investigated. ACTH (0.1 mg/kg/day) or saline as control was injected intraperitoneally in 5-week-old Wistar rats every day for 4 weeks. ACTH significantly increased adrenal weight (P < 0.05) and serum corticosterone (P < 0.05). Competitive RT-PCR analysis on the adrenocortical mRNA showed increased IGF-I (P < 0.01) at 4 weeks of ACTH and increased TGF-beta 1 (P < 0.01) at 1 week of ACTH compared the control group. ACTH also significantly increased proliferating cell nuclear antigen mRNA level (P < 0.01), at 4 weeks of treatment, which correlated with IGF-I level (P < 0.01), but correlated negatively with ACTH-stimulated TGF-beta 1 level (P < 0.05). There was a weak correlation between IGF-I and serum corticosterone (P < 0.05), and between TGF-beta 1 mRNA levels and serum corticosterone concentration (P < 0.05). Histologically, ACTH induced hypertrophy in the zona fasciculata cells and increased the clear cells containing lipid deposits. Immunohistochemistry showed that IGF-I peptide was mainly expressed in the periphery of the zona fasciculata at 4 weeks of ACTH therapy, while the same therapy caused a slight increase in TGF-beta 1 expression in the same area. Our results show that an increase in adrenocortical growth resulting from ACTH treatment is associated with an increase in IGF-I mRNA expression but only a transient increase in TGF-beta 1 mRNA expression.
Adrenal Cortex↗
Changes in endotoxin-binding proteins during major elective surgery: important role for soluble CD14 in regulation of biological activity of systemic endotoxin.
Assessment of circulating endotoxin during the perioperative period, which is only demonstrated by the Limulus amebocyte lysate (LAL) test, may be modulated by several endotoxin-binding proteins. Endotoxin-neutralizing capacity (ENC) and the plasma levels of soluble CD14 (sCD14), lipopolysaccharide-binding protein, and bactericidal/permeability-increasing protein (BPI) were determined in 40 patients 6 h prior to skin incision for major abdominal surgery. The bioactivity of plasma endotoxin was tested by the polymyxin B-inhibited stimulatory activity of the plasma samples on healthy monocytes as measured by the release of tumor necrosis factor alpha. Plasma endotoxin levels in almost all patients increased from 0.05 +/- 0.01 to 0.23 +/- 0.03 experimental units (EU) per ml (P < 0.001); more specifically, 17 of 40 samples showed endotoxin levels of greater than 0.2 EU per ml and corresponding reductions in ENC. Soluble CD14 plasma levels were decreased from 5. 6 +/- 0.3 to 4.6 +/- 0.3 microg per ml (P < 0.05). ENC was strongly correlated with the sCD14 plasma concentration throughout the period of observation. The addition of sCD14-neutralizing monoclonal anti-sCD14 antibodies reduced ENC both pre- and postoperatively. No correlation could be established between ENC and the plasma levels of BPI, high-density lipoproteins, or low-density lipoproteins determined by measuring the concentrations of apoprotein A and apoprotein B. Biologically active endotoxin was found in only 6 of 17 samples with endotoxin levels greater than 0.2 EU per ml in the LAL test. These samples could be characterized by their perioperative loss of at least 35% of their sCD14. No change in sCD14 was detected in the remaining 11 samples. The perioperative loss of ENC is partly caused by the loss of sCD14 resulting from its consumption by endotoxin reaching the bloodstream. This study demonstrated the role of sCD14 on the bioactivity of circulating endotoxin in a human model of endotoxemia after major abdominal surgery.
Abdomen↗