Biomedical subjects
Publications and source records attributed to K Nakada.
Fecal and plasma E1S of a sow with mummified fetuses, was compared with normal delivery cases. Fecal and plasma fluctuation patterns in E1S were similar. In the sow with fetal mummification both fecal and plasma E1S concentration rapidly decreased after day 80-90 compared to normal farrowing sows. This coincided with the estimated time of fetal death.
The ability of ebselen, which exhibits glutathione peroxidase (GSH-Px)-like activity, to prevent cisplatin (CDDP)-induced nephrotoxicity was examined in rats. CDDP (6 mg/kg [20 micromol/kg] body weight) was injected intraperitoneally. In subgroups, daily ebselen doses of 2.75 (10 micromol), 5.5 (20 micromol), or 11.0 mg (40 micromol)/kg body weight were administrated orally 1 hour prior to CDDP treatment. Treatment with CDDP alone resulted in significantly increased plasma creatinine (Cr) and blood urea nitrogen (BUN) levels. Repeated administration of 5.5 and 11.0 mg/kg ebselen prevented the CDDP-induced elevation of plasma Cr and BUN levels and protected against kidney damage. Relative to controls, rat that received CDDP treatment displayed a decreased ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG), an indicator directly related to oxidative stress, and elevated malondialdehyde (MDA) levels in the kidney. In comparison with controls, activity of GSH-Px activity, which antioxidant enzyme, was also reduced in the kidney of rats treated with CDDP. Repeated administration of 5.5 or 11.0 mg/kg ebselen prevented CDDP-induced alteration of GSH/GSSG ratios, MDA levels, and GSH-Px activity; however, no protection against CDDP was observed with administration of 2.75 mg/kg ebselen. Effective protection of CDDP-induced nephrotoxicity with ebselen was observed only when the molar amount of each daily ebselen treatment equaled or exceeded
To assess whether cerebral arterial blood oxygen saturation (SaO2) can be calculated by EPI, we examined the relationship between peripheral SaO2 and T2+ signal intensity (SI) changes in the brain in three normal subjects, using 1.5 Tesla MRI. To decrease SaO2, hypoxia was induced by 100% helium-gas inhalation (60 sec). SI declined as SaO2 decreased during helium inhalation, while rapid recovery of SI to the baseline was noted with recovery from hypoxia. The differential effective transverse relaxation rate was closely correlated with SaO2 (r > 0.94). Consequently, using MRI, we were able to calculate arterial SaO2.
UNLABELLED: Our aim was to evaluate the early effect of local irradiation on normal bone marrow glucose metabolism in rodents, assessed by FDG biodistribution measured by tissue excision and gamma counting. METHODS: Sixty-one rats were divided into nine groups (n = 4-11 per group). Eight groups of rats received either local irradiation (10 Gy) or sham irradiation to the right femur on day 0. Irradiation was performed using a 60Co gamma-ray unit under anesthesia. Each group of rats was fasted overnight and then injected with 5.5-7.4 MBq FDG on day 1, 9, 18, or 30 after the local or sham irradiation. A control group of rats that received neither local nor sham irradiation was studied with FDG on day 0. 18F activity in tissue 1 h after injection was measured using a gamma counter. Smear specimens of bone marrow from bilateral femurs were examined by light microscopy. RESULTS: Tracer uptake was relatively stable in marrow from the sham-irradiated rats. By contrast, FDG uptake of the irradiated marrow on day 1 was significantly higher (mean +/- SD, 0.257 +/- 0.036 percentage injected dose [ID] per gram of tissue per kilogram of rat weight [%ID/g/kg]) than that of the sham group on day 1 (0.187 +/- 0.028 %ID/g/kg) and the control group (0.184 +/- 0.009 %ID/g/kg) (P < 0.05). Tracer uptake in the irradiated marrow on day 9 was significantly lower (0.148 +/- 0.023 %ID/g/kg) than that of the sham group on day 9 (0.193 +/- 0.021 %ID/g/kg) and the control group (P < 0.01). In contrast, the nonirradiated contralateral marrow from irradiated rats showed increased FDG uptake on day 18 (0.274 +/- 0.063 %ID/g/kg) that was significantly higher than that of the sham group on day 18 (0.208 +/- 0.030 %ID/g/kg) and the control group (0.183 +/- 0.018 %ID/g/kg) (P < 0.05). The irradiated marrow smear specimens initially revealed increased percentages of neutrophils on day 1 (45% of 500 nucleoid cells examined per slide) compared with that of the sham group (20%), followed by severely decreased overall cellularity on day 9. CONCLUSION: In this experimental system, normal marrow uptake of FDG transiently rose, then fell, and ultimately returned to baseline after external beam irradiation. Knowledge of this biphasic early irradiation effect on normal bone marrow may be important when the efficacy of radiation therapy on bone metastasis is evaluated using FDG PET after irradiation.
In order to show the tissue-specific distribution of troponin T (TnT) isoforms in avian skeletal muscles, their expression was examined by electrophoresis of the breast and leg muscles of seven avian species and immunoblotting with the antiserum against fast skeletal muscle TnT. It has been reported in the chicken that breast-muscle-type (B-type) and leg-muscle-type (L-type) TnT isoforms are expressed specifically in the adult breast and leg muscles, respectively. Their differential expression patterns were confirmed in all birds examined in this study. The expression of a segment encoded by the exon x series of TnT was also examined by immunoblotting with the antiserum against a synthetic peptide derived from the exon x3 sequence, because the segment has been shown to be included exclusively in the B-type, but not in the L-type TnT. The expression of the segment was found only in the breast muscle, but not in the leg muscle of all birds examined. TnT cDNA sequences from the duck breast and leg muscles were determined and showed that only B-type TnT had an exon x-related sequence, suggesting that the expression of B-type TnT containing the exon x-derived segment is conserved consistently in the birds.
A total of 54 Holstein-Friesian cows (13 primiparous and 41 multiparous) was used to study maternal plasma oestrone sulphate (E1S) during pregnancy and its relationship to birth weight and viability of calves and time required for placental expulsion after calving. Plasma samples were obtained from the tail vein of cows once every month from days 90 to 180, every 2 weeks from days 181 to 270, and every day from day 270 of gestation to parturition. The E1S concentrations were measured by radioimmunoassay, and birth weight, placental measurements, neonatal viability and the period from calving to placental expulsion were recorded. E1S concentrations were correlated positively (0.71 > or = r > or = 0.32, P < 0.05 or P < 0.01) with calf birth weight and weights of cotyledons, intercotyledonary membranes and total placenta from days 210 of gestation to 1 day prepartum. Calf birth weight was correlated positively (p < 0.01) with the weight of the cotyledons (r = 0.87), intercotyledonary membranes (r = 0.78) and total placenta (r = 0.88). In addition, E1S concentrations were positively correlated (0.63 > or = r > or = 0.28, P < 0.05 or P < 0.01) with the neonatal viability after day 195 of pregnancy, and were negatively correlated (-0.29 > or = r > or = -0.55, P < 0.05 or P < 0.01) with the intervals from parturition to placental expulsion after 225 days of pregnancy. The results suggest that variation among dams for circulating E1S levels during late pregnancy may be caused by variation of placental development and ability for oestrogen production and conjugation, and they may influence fetal growth, neonatal viability and retained placenta.
The mechanisms of apoptosis in neuroblastomas have been investigated by examining the expression profiles of Fas, Fas ligand (FasL), and caspase 3 in 42 primary tumour tissues. Immunohistochemically, no or weak Fas expression was detected in 25 out of 29 neuroblastomas (86 per cent), whereas high levels of expression of FasL and pro-caspase 3 were noted in 30 and 29 of 42 tumours, respectively (approximately 70 per cent). Overexpression of pro-caspase 3, but not FasL, correlated significantly with a younger age and low tumour stage. Western blot analysis of ten neuroblastomas confirmed the lack of Fas expression and the presence of strong FasL expression in all samples and pro-caspase 3 expression in five tumours, of which four belonged to the favourable type. These favourable tumours also showed vigorous Asp-Glu-Val-Asp (DEVD) hydrolytic, or caspase 3-like activities, while the unfavourable tumour lacked such activity. Moreover, immunostaining for the p17 subunit of the caspase 3 heterodimer showed that active caspase 3 was mainly localized in apoptotic tumour cells. Combined together, our results suggest that caspase 3, activated via a Fas-independent pathway, may play important roles in apoptosis, suppression of growth, and, in some cases, regression of favourable neuroblastomas.
We reviewed Tc-99m DMSA scintigraphy in children with vesicoureteral reflux (VUR) in order to assess whether repeated Tc-99m DMSA scans are necessary for the follow up of these patients. Ninety-seven children who were followed up for more than one year (1-7.4 years, average 2.8 years) after the first DMSA scan were included in the study. Fifty-one patients had been diagnosed as primary VUR and 46 as secondary VUR. Age at the first examination ranged from 0 to 14 years (average 5.1 years). Planar images were taken 2 hours after injection. The % renal uptake per injected dose (%RU) was calculated from posterior images. Kidneys in 11 patients (11.3%) changed morphologically during the follow up. Of these, new photon deficient areas (PD) were detected in only 4 patients (4.1%). All of these 4 patients had neurogenic bladder and were managed with self-catheterization. Of the remaining 7 patients, cortical thinning progressed in 5 patients (5.2%) and PDs resolved in 3 patients (3.1%). In one of these 7 patients, PD resolved in one kidney and cortical thinning progressed in the contralateral kidney. Of 97 patients reviewed, % RU decreased more than 20% during the follow up in 6 patients (6.2%). All were diagnosed as secondary VUR due to neurogenic bladder. %RU decreased only in the contracted kidneys at the initial scan. Two of them underwent renal transplantation because of severe renal failure. In conclusion, new PD rarely developed and % RU decreased in only a few patients during the follow up of children with VUR. Repeated Tc-99m DMSA scintigraphy therefore seems to have little benefit in the follow up of children with VUR. It should be performed in selected patients with high risk of urinary tract infection or renal failure.
BACKGROUND/PURPOSE: The type of renal dysplasia resulting from obstructive uropathy depends on the completeness of the obstruction and its timing with respect to the stage of glomerulogenesis at the time of the obstruction. The authors created a successful obstructive uropathy model in the female fetal lamb to demonstrate the differing pathogenesis of renal dysplasia. METHODS: Female fetal lambs at 60 and 90 days' gestation had their urethra and urachus ligated transabdominally and were delivered by cesarean section at 145 days (full term). Kidney length and cortical thickness were measured, and samples were examined histologically. In the lambs operated on at 90 days, the urine was collected at delivery and Na and CI were measured and compared with the results obtained from normal full-term lambs. RESULTS: Seven of 10 female lambs had hydronephrosis or dysplastic kidneys. The cortext to kidney length ratio was 10+/-3% in the 90-days hydronephrotic group versus 29+/-6% in the controls (P<.001). Morphologically, the 90-day model had dilatation of the collecting tubules with normal glomerular numbers. The 60-day model had tubular cysts with fibromuscular cuffing and reduced glomerular numbers. The fetal urine Na was 47+/-3.3 mmol/L in controls versus 78+/-24 mmol/L in the hydropnephrotic lambs (P<.05). The urine CI in these lambs was 38+/-8.6 mmol/L in controls versus 55+/-14.5 mmol/L in the hydronephrotic lambs (P<.05). CONCLUSIONS: An obstructive uropathy model was created in female fetal lambs. There were no dysplastic changes in the kidneys in lambs operated on at 90 days' gestation, but there were definite dysplastic changes in those operated on at 60 days. Concentrations of Na and CI in the fetal urine are higher than normal in the 90-day model.
We investigated the relationship between active oxygen species (AOS) generation and cultured vascular endothelial cellular damage caused by simultaneous exposure to selenium compounds and sulfhydryl compounds such as cysteine (Cys) or reduced glutathione (GSH). Selenium compounds, selenite, selenate or selenomethionine (SeMet), are added to total parenteral nutrition (TPN) and intravenously administered. We confirmed by luminol dependent chemiluminescence, an indicator of AOS generation, that selenite generates AOS in the presence of clinical concentrations of sulfhydryl compounds, 0.5 mM Cys or 0.5 mM GSH, and that the amount of AOS generated reaches the maximum when their mole ratio is 1:50. However, AOS generation was not observed after simultaneous administration of various concentrations of selenate or SeMet with sulfhydryl compounds. Moreover, simultaneous exposure to 10 microM selenite and sulfhydryl compounds was found to result in significant increases in the [3H]-adenine and lactate dehydrogenase (LDH) release rates from cells, a significant decrease in the amount of cellular protein, and enhancement of cellular damage as compared with after exposure to selenite alone. However, simultaneous exposure to 10 microM selenate or 10 microM SeMet together with sulfhydryl compounds did not induce cellular damage. These findings revealed that selenite generates AOS and causes cellular damage in the presence of sulfhydryl compounds. Accordingly, it seems better to choose selenate or SeMet instead of selenite when a selenium compound is to be added to TPN.
To elucidate the mechanism that produces enormous molecular diversity in troponin T (TnT) of fast skeletal muscle, we determined the 5'-half genomic sequence of the chicken fast muscle TnT gene. The sequence of ca. 16 kb included seven exons (exons 1, 2, 3, 4, w, 5, and 6), which have been reported previously and presumed by sequencing TnT cDNAs. Additionally we found six 15 nt and one 18 nt sequences in the region between exons 5 and 6 (i.e. the exon x region). They were encompassed by consensus splice donor and acceptor sites and preceded by putative branch sites, and designated herein as exons xa to xg. Our result shows that the sequence derived from exons x1, x2, and x3, the exons presumed previously by cDNA sequencing, is actually encoded by the seven exons xa to xg, establishing the precise gene structure in the exon x region. Based on our data, together with that on the 3'-half genomic sequence of the quail fast muscle TnT gene, we conclude that the avian fast skeletal muscle TnT gene includes 27 exons, 16 of which are alternatively spliced.
PURPOSE: According to initial reports, stage 4 neuroblastoma patients with amplification of the MYCN proto-oncogene developed progressive disease within 8 months. The prognosis for such patients, however, should now be reevaluated in light of recent results achieved with up-to-date combination chemotherapy. PATIENTS AND METHODS: Patients with stage 3, 4, and 4S neuroblastoma and more than 10 copies of MYCN received induction chemotherapy, which from January 1985 to February 1991 consisted of regimen A(1 )(cyclophosphamide 1,200 mg/m(2) on day 1, vincristine 1.5 mg/m(2) on day 1, pirarubicin 40 mg/m(2) on day 3, and cisplatin 90 mg/m(2) on day 5) and from March 1991 to September 1993 consisted of regimen A(3 )(cyclophosphamide 1,200 mg/m(2) on days 1 and 2, pirarubicin 40 mg/m(2) on day 3, etoposide 100 mg/m(2) on days 1 through 5, and continuous infusion cisplatin 25 mg/m(2) on days 1 through 5). Most of these patients underwent radical surgery to remove the original tumor and local metastases, irradiation, and supralethal preconditioning regimens, followed by blood stem-cell transplantation (SCT). Data on the patients were collected in December 1998, and the factors contributing to disease-free survival were analyzed. RESULTS: During the study period, 66 patients with more than 10 copies of MYCN were treated. Five of nine patients with stage 3 disease, 13 of 55 with stage 4, and one of two with stage 4S survived for at least 66 months. It is interesting that all but one patient who survived for more than 66 months underwent SCT, in contrast with only five of 45 patients who died. CONCLUSION: Not all patients with advanced neuroblastoma who have more than 10 copies of MYCN will die. The requisites for survival in such patients seem to be intensive induction chemotherapy, effective surgery, irradiation, and the use of SCT.
The aim of this study was to establish radioimmunoassay (RIA) for fecal estrone sulfate (E1S) and to elucidate changes in fecal E1S during pregnancy in the sow. Fecal E1S was extracted on a commercially available solid phase column, and the E1S fraction obtained was subjected to RIA. The sensitivity of the RIA was 8.5 pg/tube. The intra- and inter-assay coefficients of variation were 8.8-8.9% and 10.7-14.2%, respectively. Mean recovery for E1S added to fecal samples was as high as 95.0%. A significant positive correlation (r = 0.904, n = 147 p < 0.0001) existed between fecal and plasma E1S concentrations. Mean E1S concentration in feces and plasma fluctuated exhibiting two peaks. The first peak of E1S concentration was evident on day 28-32 in feces and on days 26-30 in plasma. The E1S concentration in both feces and plasma remained at baseline levels during mid-pregnancy, but began to rise gradually around days 72-82 and 70-80, in feces and plasma respectively, and reached a peak concentration on days 110-114. Following parturition, the concentration of E1S in plasma declined rapidly, but there was a two-day delay before a decline in fecal E1S. Apart from this two-day delay, changes in fecal E1S were similar to those in plasma E1S. The study indicates that the measurement of E1S in feces could be a useful tool for early pregnancy diagnosis and for monitoring fetal development in sows and gilts.
An experiment using 16 Beagle bitches (aged 11 months to 6 years and 2 months) in their 56th to 58th day of pregnancy was carried out to investigate the effects of two injections of a low dose of fenprostalene, a long-acting prostaglandin F2alpha analogue, and pretreatment with prifinium bromide, a parasympathetic nerve blocking agent, on the induction of parturition and severity of side effects. The bitches were divided into three treatment groups: one injection of 5 microg/kg of fenprostalene (group I, n=5); one injection of 7.5 mg/head of prifinium bromide followed by one injection of 5 microg/kg of fenprostalene at 5 min after prifinium bromide injection (group II, n=6); and one injection of 7.5 mg/head of prifinium bromide followed by two injections of 2.5 microg/kg of fenprostalene, one injection at 5 min after prifinium bromide injection and the next at 1 hr after the fenprostalene first injection (group III, n=5). Following the injection of fenprostalene, side effects such as salivation, vomiting, colic symptoms, and watery diarrhea occurred most frequently (80-100% of cases) in group I bitches. Apart from colic symptoms, no side effects were observed in group III bitches. Group III bitches also showed the smallest increase in plasma cortisol concentration. No significant difference in the time to initiation of parturition was found between the three groups. The one-week survival rate of newborn puppies was highest in group III. The results showed that pretreatment with prifinium bromide and two injections of 2.5 microg/kg of fenprostalene can alleviate side effects following fenprostalene administration and have no adverse effect on the survival of newborn puppies, indicating that this method is a reliable and safe way of inducing parturition in bitches.
Thirteen primiparous and 41 multiparous Holstein-Friesian cattle were used to study the relationship between maternal plasma progesterone (P4) and estrone sulfate (E1S) concentrations and the prevalence of dystocia. The calvings in 4 heifers and 30 cows were normal (eutocia), while the calvings in 9 heifers and 11 cows were difficult (dystocia). Neither the concentrations of P4 nor E1S were different between the groups with eutocia and dystocia from days 90 to 270 of pregnancy. However, a few days prior to parturition, eutocial cows and heifers showed a sharp decline of plasma P4, while dystocial cattle did not show such a remarkable decline of P4 concentration. Plasma P4 levels in dystocial cows a few days antepartum were significantly higher than in eutocial animals (P<0.05 or P<0.01). Prepartum E1S concentrations were significantly lower (P<0.05) in dystocial than eutocial cattle during the prepartum period from days 6 to 1 in heifers and from days 3 to 1 in cows. These results suggest that insufficient production of E1S and delayed regression of the corpora lutea are possible causes of dystocia in cattle.
The aim of the present study was to examine the LH response to exogenous estradiol in 4 heifers with ACTH-induced ovarian follicular cysts. During the control experiment, administration of estradiol 24 hr after PGF2alpha in luteal phase heifers resulted in a LH response in all 4 heifers. The LH response was obtained between 16-20 hr after estradiol administration. The peak LH concentration (Mean +/- SEM; 5.1 +/- 0.8 ng/ml) during the control study was significantly different (P<0.05) from the concentration after cyst formation. None of the 4 heifers responded to estradiol after ovarian cyst formation. This result suggests that heifers with ACTH-induced ovarian follicular cysts may have a defective hypothalamio-pituitary response to exogenous estradiol similar to cows with spontaneous ovarian cysts.
UNLABELLED: A prospective study of 201TI uptake was performed to compare 201TI uptake with nuclear deoxyribonucleic acid (DNA) content and clinical behavior of tumors in metastatic thyroid carcinoma and to assess the significance of 201TI uptake in evaluating clinical characteristics of thyroid carcinoma. METHODS: Fifty-six patients with metastases of differentiated thyroid carcinoma had 201TI scintigraphy. Grade of 201TI uptake was semiquantitatively assessed according to tumor-to-background ratio on 2-h late scan. Nuclear DNA content was analyzed within 3 wk of 201TI study by flow cytometry using biopsy material and was classified as diploidy or aneuploidy. Patients were followed up to examine incidence of tumor growth and/or anaplastic transformation. RESULTS: DNA content was diploidy in 48 patients and aneuploidy in 8 patients. 201TI uptake in the DNA-aneuploid group (2.61 +/- 0.29) was significantly higher than that in the DNA-diploid group (1.82 +/- 0.35, P < 0.01 for both groups). Tumor growth was observed in all patients with DNA aneuploidy but in only 5 of 48 patients with DNA diploidy (P < 0.01). Anaplastic transformation was observed in 3 patients in the DNA-aneuploid group but in none of the patients in the DNA-diploid group. CONCLUSION: High 201TI uptake indicates greater incidence of abnormal DNA content with aggressive clinical behavior of metastatic tumors. Thus, 201TI scintigraphy may be useful in characterizing metastatic thyroid carcinoma and in identifying those patients with poorer prognoses.
The objectives of the present study were to clarify and compare the characteristics of the transient rises in intracellular calcium concentrations ([Ca2+]i) induced either by spermatozoa or by stimulation with artificial activators in bovine oocytes. These transient rises in [Ca2+]i in oocytes matured in vitro were recorded with Ca2+ imaging using the Ca2+ indicator fura-2. During fertilization, a series of transient rises in [Ca2+]i was observed. The first Ca2+ response peaked at a concentration of 521 +/- 39 nM (n = 20) and lasted for 4 min, while the subsequent Ca2+ responses were significantly smaller and shorter, with a peak of 368 +/- 13 nM (n = 23) and a duration of 2 min. Injection of inositol 1,4,5- triphosphate (InsP3) into unfertilized oocytes caused a transient rise in [Ca2+]i in a dose-dependent manner. The maximum response was induced by 20 nA x 1 sec injection of InsP3. Thimerosal, a sulfhydryl reagent, induced the repetitive transient rises in [Ca2+]i. The peak and the duration of the rises in [Ca2+]i induced by InsP3 or thimerosal were smaller and shorter, respectively, than those of the first rise induced by spermatozoa. Ethanol and Ca2+ ionophore IA23187, which are general parthenogenetic activators of unfertilized oocytes, each induced a single transient rise in [Ca2+]i. The duration of the rise in [Ca2+]i by ethanol or Ca2+ ionophore was significantly longer than that by spermatozoa at fertilization, although the peaks were smaller. These results clarified the characteristics of the rises in [Ca2+]i induced by spermatozoa and by several artificial reagents, and showed that the first rise in [Ca2+]i induced by spermatozoa had a higher peak [Ca2+]i and a longer duration compared with each the subsequent rises in [Ca2+]i and the rises in [Ca2+]i induced by artificial reagents. These indicate that a mode like as the first rise in [Ca2+]i induced by spermatozoa is an effective trigger for artificial activation of oocytes.