Biomedical subjects
Publications and source records attributed to T Iida.
The authors report the case of a 59-year-old woman with progressive neck and arm pain that initially appeared in the neck and later extended to the shoulder and upper extremity. This pain was caused by compression of the cervical cord between the atlas and axis by the vertebral artery, and disappeared promptly following microvascular decompression.
Thoracic disc herniation is a rare and slowly progressive disease which most commonly occurs at the lower thoracic spine without any preceding trauma. We reported a case with acutely developed vesicorectal dysfunction due to a ruptured disc at Th 11-12. This symptom disappeared soon after disc removal via the transpedicular approach combined with transversectomy. This 45-year-old woman suddenly suffered, without previous trauma, from severe back pain radiating down to the posterior thighs. Since difficulty in urination and defecatory incontinence succeeded two days later, she was transferred to our hospital. Neurological examination on admission revealed anesthesia below S1, hypotonic bladder with almost perfectly preserved urinary sensation, complete lack of anal reflex, and only weak motor function in the lower extremities. Both knee and ankle jerks were diminished bilaterally. A herniated disc was initially suspected at L5-S1 on the MRI, but denied by both myelography and CT myelography. These studies showed a disc hernia compressing the cord at Th 11-12 on the left side. Since the hernia was located centrolaterally, we employed the transpedicular approach. To make removal of the more centrally located hernia easier, we further added transversectomy of the twelfth vertebra. This hernia was successfully removed under the operating microscope without further damage to the cord being incurred. We did not perform any instrumental fixation, because we thought preservation of the rib and costvertebral joint could contribute to the stability of the spine. Her vesicorectal symptom subsided immediately after the operation. She was free of any symptoms except for the remaining mild perianal numbness a year and seven months postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)
Levels of PCDDs, PCDFs and coplanar PCBs were measured in human breast milk obtained from two Yusho patients and nine healthy subjects. The concentrations of PCDDs, PCDFs and coplanar PCBs in the breast milk of respective Yusho patients were 18.2 and 28.9, 168.8 and 418.3, and 23.8 and 55.1 pg Toxic Equivalents (TEQs)/g fat, respectively, and their mean concentrations in normal controls were 8.2, 5.1 and 21.8 pg TEQ/g fat, respectively. The results also indicated that there was a significant difference between Yusho patients and normal subjects in the concentrations of certain isomers of PCDDs, PCDFs and coplanar PCBs in the breast milk. For example, the levels of 1, 2, 3, 6, 7, 8-HxCDD were 4 and 8 times higher than the mean concentration in the normal subjects, and 2, 3, 4, 7, 8-PeCDF, 1, 2, 3, 4, 7, 8-HxCDF and 1, 2, 3, 6, 7, 8-HxCDF, so-called 'Yusho isomers' were 15 to 98 times higher than those in the normal subjects. Daily intakes of TEQ values were estimated to be 506 and 2200 pg TEQs/kg/day for breast-feeding babies of Yusho patients, and to be from 97 to 197 pg TEQs/kg/day for healthy subjects. These TEQ values were much greater than the ADI of 1-10 pg/kg/day, therefore, we should give due attention to the possible health effects due to PCDDs, PCDFs and coplanar PCBs in the breast milk of healthy mothers, as well as Yusho mothers.
This study was focused on the changes of high energy phosphates and tissue blood flow (TBF) in ischemia and reperfusion, of jaundiced rat liver. We ligated and cut the bile duct of male Wistar rats to induce jaundice. The rats were divided into two groups, BDL-4W which had ligation four weeks before examination and control which had no ligation. Two studies were performed; In study A, ischemia was induced by clamping portal vein and hepatic artery for 60 minutes. In study B, 15 minutes of ischemia was repeated four times with intervals of 10 minutes of reperfusion. A: 1) In BDL-4W, ATP was significantly lower than that in control at pre-ischemia and reperfusion. Recovery ratios (RR) of ATP in BDL-4W were significantly lower than those in control. 2) RR or TBF in BDL-4W were significantly lower than those in control. 3) In BDL-4W, xanthine was significantly higher than that in control at reperfusion. B: 4) There were no significant differences in the RR of ATP after reperfusion between two groups. 5) There were no significant differences in the RR of TBF between two groups. 6) There were no significant differences in xanthine after reperfusion between two groups. We concluded that intermittent brief ischemia was useful when 60 minutes of ischemia was required for the operation of jaundiced liver.
It is well-known that Yusho disease was caused by polychlorinated dibenzofurans (PCDFs), and that 2, 3, 4, 7, 8-Pentachlorodibenzofuran (PnCDF), 1, 2, 3, 4, 7, 8- and 1, 2, 3, 6, 7, 8-Hexachlorodibenzofurans (HxCDFs) still retain in the patient bodies. As patients usually suffer from various chronic syndrome, an effective treatment is extremely needed. In order to assess the rice bran fiber (RBF) and cholestyramine on stimulating faecal excretion of PCDFs, two clinical trials were carried out in 1990 and 1991. In the first trial in 1990, 10 g of RBF (dietary fiber content was 50%) and 4 g of cholestyramine were administered to four Yusho patients three times a day for a week. The stool from patients were collected a week before and during the administration. These were pooled respectively, and then two samples for measurement. In the second trial in 1991, 10 g of dietary fiber rich RBF (refined-RBF, dietary fiber content was 85%) and 4 g of cholestyramine were administered to four Yusho patients three times a day for two weeks. In this trial, three stool samples were obtained from each patient, ie., a week before administration, and first and second week during administration. Level of PCDFs was determined by high resorption GC/MS and the following results were obtained. 1) In the first trial (1990) the faecal excretion of PnCDF and HxCDFs increased at the rates of 42-88% and 7-47%, respectively, in three out of four patients.(ABSTRACT TRUNCATED AT 250 WORDS)
We investigated the stimulating effect of dietary fiber on fecal excretion of PCDF and PCDD stored in the rat body. Twenty-eight male rats (71-74g body weight) were orally administered with 1ml of the causal rice oil of Yusho desease. The rice oil was contaminated with 2, 3, 4, 7, 8-pentaCDF (691.4ng), 1, 2, 3, 4, 7, 8-hexaCDF (708.6ng), 1, 2, 3, 6, 7, 8-hexaCDF (128.4ng), 1, 2, 3, 7, 8-pentaCDD (7.2ng), 1, 2, 3, 6, 7, 8-hexaCDD (34.1ng), 1, 2, 3, 7, 8, 9-hexaCDD (20.1ng) and 1, 2, 3, 4, 6, 7, 8-heptaCDD (115.9ng). The animals were fed a control diet containing 10% cellulose for seven days. Twenty-eight rats consisting of four rats a group were housed and rats of each group were given a treatment diet containing 10% rice-bran-fiber (RBF), 5% cholestyramine, 10% RBF + 5% cholestyramine, 10% RBF + 5% cholestyramine + 1% squalane, 10% burdock-fiber, 10% corn-fiber and 10% soybean-fiber during a period from eight to twenty-one days. The remaining four rats served as controls. PCDF and PCDD in feces, liver, small intestine and gastrointestinal tract were analyzed by high resolution gas chromatography-mass spectrometry. PCDF level in small intestine of rats administered with RBF + cholestyramine showed a decrease of 40% over the level of control rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Extracts prepared from tissue with granulomatous inflammation experimentally produced in liver of CBA-strain mice showed increased hydrolysis of leukotriene D4 (LTD4), Leu-Leu and Ala-Gly as compared with normal hepatic cells. Two dipeptidases, Leu-Leu dipeptidase and Ala-Gly dipeptidase, were purified from hepatic granulomas, and quantitative conversion of LTD4 into leukotriene E4 (LTE4) by both enzymes was demonstrated. M(r) values of the purified enzymes were 178,000 for Leu-Leu dipeptidase and 183,000 for Ala-Gly dipeptidase. The enzymes showed homogeneity, appearing as a single band on SDS/PAGE, and the M(r) values of the subunits were 56,000 and 57,000 for Leu-Leu and Ala-Gly dipeptidase respectively. The amino acid compositions of the two enzymes differed considerably from each other. The activity of Leu-Leu dipeptidase was inhibited by bestatin and captopril and stabilized with MnCl2. The Km for LTD4 was 25 microM with a V(max.) of 49.0 mumols/min per mg. In contrast, the activity of Ala-Gly dipeptidase was inhibited by cilastatin, cytinylglycine, EDTA and dithiothreitol, and also by captopril. The Km for LTD4 was 5.3 microM with a V(max.) of 50.4 mumols/min per mg. The findings indicate that the conversion of LTD4 into LTE4 by microsomal dipeptidases is elevated during granulomatous tissue reaction. This enzyme activity may become useful for biochemical quantification of the pathological tissue reaction that occurs in organized granulomas.
Pituitary gonadotrophs exhibit spontaneous low-amplitude fluctuations in cytoplasmic calcium concentration ([Ca2+]i) due to intermittent firing of nifedipine-sensitive action potentials. The hypothalamic neuropeptide, gonadotropin-releasing hormone, terminates such spontaneous [Ca2+]i transients and plasma-membrane electrical activity and initiates high-amplitude [Ca2+]i oscillations and concomitant oscillations in membrane potential (Vm). The onset of agonist-induced [Ca2+]i oscillations is not dependent on Vm or extracellular Ca2+ but is associated with plasma-membrane hyperpolarization interrupted by regular waves of depolarization with firing of action potentials at the peak of each wave. The Vm and Ca2+ oscillations are interdependent during continued gonadotropin-releasing hormone action (greater than 3-5 min), when sustained Ca2+ entry is necessary for the maintenance of [Ca2+]i spiking. The initial and sustained agonist-induced Ca2+ transients and Vm oscillations are abolished by blockade of endoplasmic reticulum Ca(2+)-ATPase, consistent with the role of Ca2+ re-uptake by internal stores in the oscillatory response during both phases. Such a pattern of synchronization of electrical activity and Ca2+ spiking in cells regulated by Ca(2+)-mobilizing receptors shows that the operation of the cytoplasmic oscillator can be integrated with a plasma-membrane oscillator to provide a long-lasting signal during sustained agonist stimulation.
A method for the determination of 4- and 6-hydroxylated bile acids with a vicinal glycol moiety in human urine by gas chromatography-mass spectrometry with negative ion chemical ionization detection is described. The 4 beta-hydroxylated bile acids labelled with 18O and 2H were prepared as internal standards by the exchange reaction of the carbonyl group on the steroid nucleus with H2(18)O, followed by metal deuteride reduction. Bile acids in urine were extracted with a Sep-Pak C18 cartridge and, after solvolysis and hydrolysis of the conjugated forms, transformed into pentafluorobenzyl ester diethylhydrogensilyl ether diethylsilylene derivatives. Subsequent resolution into individual 4- and 6-hydroxylated bile acids was carried out on a cross-linked fused-silica capillary column; a characteristic carboxylate anion, [M-PFB]-, was used to monitor each bile acid in the negative ion mode. The newly developed method was applied to the separation and determination of 4- and 6-hydroxylated bile acids in a urine specimen from a newborn infant.
Activity of prolyl endopeptidase (EC 3.4.21.26) which hydrolyses the Pro7-Phe8 bond in angiotensin II has been found to elevate in experimentally produced granulomatous inflammation in liver and skin. We purified the enzyme 1,536-fold by 6 steps from murine hepatic granulomas. The purified enzyme has a molecular weight of 79 kDa and physicochemical properties equivalent to those previously reported for prolyl endopeptidase purified from other sources. By HPLC analysis, the cleavage of Phe8-Leu10 and Phe8 from angiotensin I and II, respectively, was detected and quantified. Monospecific IgG was prepared from serum of rabbits injected with purified enzyme. Concentration of the enzyme was immunohistochemically detected in cells which form granulomatous organization, but not in inflammatory cells surrounding the foci. The antibody, however, cross reacted with the enzyme in adjacent liver cells and weakly stained their cytoplasm. The findings indicate that this enzyme, in addition to angiotensin converting enzyme, may serve as a useful biochemical marker for granulomatous tissue reactions.
The aim of the present study was to further investigate the role of the adrenergic system on insulin action using the euglycemic clamp technique. Whole-body glucose metabolism (GM) was calculated as the glucose infusion rate for maintaining euglycemia under insulin infusion and used as an indicator of insulin sensitivity. Euglycemic clamps were performed in adrenodemedullated, epinephrine-treated, phentolamine-treated (alpha-blockade), propranolol-treated (beta-blockade), and epinephrine plus phentolamine and/or propranolol-treated rats. The following results were obtained at an insulin level of approximately 80 mU/l. GM in adrenodemedullated rats (13.97 +/- 0.98 mg/kg/min) was significantly higher than that of the control rats (10.26 +/- 0.50 mg/kg/min, P less than 0.01). GM in epinephrine-treated rats (1.7 mg/kg body weight/h) was 2.12 +/- 0.49 mg/kg/min (P less than 0.001 vs. control). Dose-response curves for phentolamine and propranolol established maximally effective doses (3.0 mg and 12 mg/kg body weight/h, respectively). Using these doses, GM in epinephrine plus phentolamine-treated rats (4.90 +/- 0.39 mg/kg/min) was significantly higher than that of epinephrine alone and GM in epinephrine and propranolol-treated rats (4.49 +/- 0.47 mg/kg/min) was also significantly higher than that of the epinephrine alone. GM in the epinephrine plus both propranolol and phentolamine (5.94 +/- 0.45 mg/kg/min) was significantly higher than that of the epinephrine alone, but not different from either treatment alone and was not additive. Neither phentolamine alone (9.48 +/- 1.45 mg/kg/min), propranolol alone (10.36 +/- 0.55 mg/kg/min) or the combination of blockades (11.14 +/- 0.65 mg/kg/min) had any effect on GM.(ABSTRACT TRUNCATED AT 250 WORDS)
In cultured pituitary gonadotrophs, gonadotropin-releasing hormone (GnRH) caused dose-dependent and biphasic increases in cytoplasmic calcium concentration ([Ca2+]i) and LH release. Both extra- and intracellular calcium pools participate in GnRH-induced elevation of [Ca2+]i and LH secretion. The spike phase of the [Ca2+]i response represents the primary signal derived predominantly from the rapid mobilization of intracellular Ca2+. In contrast, the prolonged phase of the Ca2+ signal depends exclusively on Ca2+ entry from the extracellular pool. The influx of Ca2+ occurs partially through dihydropyridine-sensitive calcium channels. Both [Ca2+]i and LH responses to increasing concentrations of GnRH occur over very similar time scales, suggesting that increasing degrees of receptor occupancy are transduced into amplitude-modulated Ca2+ responses, which in turn activate exocytosis in a linear manner. However, several lines of evidence indicated the complexity over the relationship between Ca2+ signaling and LH exocytosis. In contrast to [Ca2+]i measurements in cell suspension, single cell Ca2+ measurements revealed the existence of a more complicated pattern of Ca2+ response to GnRH, with a biphasic response to high agonist doses and prominent oscillatory responses to lower GnRH concentrations, with a log-linear correlation between GnRH dose and the frequency of Ca2+ spiking. In addition, analysis of the magnitudes of the [Ca2+]i and LH responses of gonadotrophs to a wide range of GnRH concentrations in the presence and absence of extracellular Ca2+, and to K+ and phorbol ester stimulation, showed non-linearity between these parameters with amplification of [Ca2+]i-mediated exocytosis. Studies on cell depleted of protein kinase C under conditions that did not change the LH pool suggested the participation of protein kinase C in this amplification, especially during the plateau phase of the secretory response to GnRH.
1. Laying hens were given food containing per kg diet: 1 mg pyrimethamine, 10 mg sulphadimethoxine (SDM) or 1 mg pyrimethamine with 10 mg SDM, for 14 days. Residues in the eggs were determined by high performance liquid chromatography. 2. Pyrimethamine was mainly found in yolk. Its concentration was slightly higher when it was given with SDM. 3. The concentrations of SDM in eggs were not different when it was given alone or in combination with pyrimethamine. 4. After withdrawal, pyrimethamine residues decreased below the detection limit (0.02 mg/kg) in the yolk after 11 to 12 d and in the albumen after 2 to 3 d. SDM in yolk fell below the detection limit (0.01 mg/kg) on day 7, whereas in albumen it was not detectable after 2 to 3 d.
In Xenopus laevis oocytes, activation of angiotensin II (AII) receptors on the surrounding follicular cells sends a signal through gap junctions to elevate cytoplasmic calcium concentration ([Ca2+]i) within the oocyte. The two major candidates for signal transfer through gap junctions into the oocyte during AII receptor stimulation are Ins(1,4,5)P3 and Ca2+. In [3H]inositol-injected follicular oocytes, AII stimulated two- to fourfold increases in phosphoinositide hydrolysis and production of inositol phosphates. Injection of the glycosaminoglycan, heparin, which selectively blocks Ins(1,4,5)P3 receptors, prevented both AII-stimulated and Ins(1,4,5)P3-induced Ca2+ mobilization in Xenopus follicular oocytes but did not affect mobilization of Ca2+ by ionomycin or GTP. These results indicate that the AII-regulated process of gap junction communication between follicular cells and the oocyte operates through an Ins(1,4,5)P3-dependent mechanism rather than through transfer of Ca2+ into the ooplasm and subsequent Ca(2+)-induced Ca2+ release.
Epidermolysis bullosa acquisita (EBA) is a rare acquired subepidermal blistering disorder associated with autoimmunity to type VII collagen. Although the full clinical spectrum of EBA is still being defined, it is now known that EBA has greater clinical heterogeneity than previously suggested. We describe a patient with EBA which closely approximated the severity of the recessive form of dystrophic epidermolysis bullosa.
The effects of cryopreservation on early embryonic development were investigated in Chinese hamster embryos. Embryos were randomly divided into 3 groups, as follows: the control group, embryos which were simply cultured; the DMSO group, embryos which were exposed to dimethyl sulfoxide (DMSO) and then cultured; the cryopreservation group, embryos which were cryopreserved and then cultured. The percentages of embryos which developed into blastocysts after 40 hours of cultivation were high in all groups. However, there were significant differences in the mean number of blastomeres with lower values after an exposure to DMSO and cryopreservation (73.2 in the control group, 62.0 in the DMSO group, and 40.2 in the cryopreservation group). No significant differences in chromosome abnormality rate were evident and there was no distinct tendency for variation in karyotype among the 3 groups. These results indicate that DMSO adversely affects the division of blastomeres, and that cryopreservation with DMSO as a cryoprotectant might aggravate these adverse effects.
In agonist-stimulated clonal pituitary gonadotrophs (alpha T3-1 cells), cytoplasmic calcium ([Ca2+]i) exhibited rapid and prominent peak increases, followed by lower, but sustained, elevations for up to 15 min. The [Ca2+]i response to GnRH was rapidly inhibited by prior addition of a potent GnRH antagonist. In the absence of extracellular Ca2+ the initial peak [Ca2+]i response was only slightly decreased, but the prolonged increase in [Ca2+]i was abolished, indicating that the peak is derived largely from intracellular calcium mobilization and the sustained phase from Ca2+ influx. Application of the endoplasmic reticulum Ca(2+)-ATPase blocker thapsigargin caused progressive and dose-dependent elevation of [Ca2+]i and decreased the peak amplitude of the GnRH-induced Ca2+ response. On the other hand, addition of dihydropyridine calcium channel antagonists before or after GnRH treatment prevented or terminated the plateau phase, respectively, consistent with entry of Ca2+ through L-type voltage-sensitive Ca2+ channels (VSCC) as the major Ca2+ influx pathway during GnRH action. The presence of L-type VSCC in alpha T3-1 cells was further indicated by the ability of elevated extracellular K+ levels and the dihydropyridine calcium channel agonist Bay K 8644 to elevate [Ca2+]i in an extracellular calcium-dependent manner. These actions of depolarization and Bay K 8644 were inhibited by nifedipine, with an IC50 of 10 nM. High extracellular K(+)- and GnRH-induced Ca2+ entry was also attenuated by phorbol esters and permeant diacylglycerols, indicating that protein kinase-C exerts inhibitory modulation of VSCC activity. In contrast to normal pituitary gonadotrophs, in which GnRH induces a frequency-modulated oscillatory [Ca2+]i response, single alpha T3-1 cells exhibited a nonoscillatory amplitude-modulated signal during agonist stimulation. The [Ca2+]i responses observed in alpha T3-1 gonadotrophs indicate that the immortalized cells retain functional GnRH receptors and their coupling to the Ca2+ signaling pathway. Ca2+ influx through L-type channels maintains the plateau phase of the [Ca2+]i response during agonist stimulation and is inhibited by activation of protein kinase-C.
Endothelin (ET) and GnRH act through specific receptors to promote Ca2+ mobilization and influx pathways in pituitary gonadotrophs. In the present study cytoplasmic calcium ([Ca2+]i) and secretory responses to these two agonists are compared. In single gonadotrophs, low concentrations of both agonists cause oscillatory [Ca2+]i responses after a latent period. Such responses usually consist of discrete transients arising from the normal resting level, but are sometimes super-imposed on an elevated basal calcium level. At high doses, ET-1 and GnRH induce biphasic responses, composed of a spike phase followed by a plateau that often shows high frequency and low amplitude Ca2+ transients. The duration of the latent period and the frequency of the subsequent oscillations are correlated, and both are dependent on agonist concentration. The frequencies and amplitudes of Ca2+ spiking are also interrelated; increases in frequency are followed by more rapid decreases in the amplitude of the Ca2+ transients. After K(+)-induced depolarization, gonadotrophs retain their oscillatory Ca2+ responses to ET-1 and GnRH, with the same frequency as controls. Activation of protein kinase-C by phorbol esters does not alter the frequency of ET-induced Ca2+ transients, but significantly reduces their amplitudes. In contrast, treatment with nanomolar concentrations of thapsigargin converts ET-induced oscillations into a biphasic response, suggesting that Ca(2+)-ATPase in the endoplasmic reticulum participates in the oscillatory mechanism. The two agonists differ in their threshold doses and concentration dependence, ET being significantly less potent than GnRH. Also, gonadotrophs stimulated by ET-1 exhibit different post-treatment responsiveness than those exposed to GnRH. While GnRH-treated cells recover their full [Ca2+]i and secretory responses within 30 min as well as normal [Ca2+]i and secretory responses to ET-1, endothelin-treated cells are refractory to further stimulation with ET and exhibit either attenuated or enhanced Ca2+ and LH responses to GnRH, depending on the duration of exposure to ET-1 and the subsequent recovery period. These data indicate that both receptors use the same mechanism(s) for Ca2+ release, but have different capacities to generate, maintain, and reinitiate the Ca2+ signal.