Search PubMed⌕ Search

Biomedical subjects

M Uchiyama

Publications and source records attributed to M Uchiyama.

At least 19 recordsLinked to original sources
PubMed1999

Chemical and immunochemical characterization of limulus factor G-activating substance of Candida spp.

The limulus test is a well-established method for the diagnosis of both gram (-) sepsis and invasive fungal infection. To diagnose deep-seated fungal infections, a (1-->3)-beta-D-glucan-specific chromogenic kit (Fungitec G test MK) has been developed and applied clinically. It is suggested that the limulus reactive substance was released from the fungi to the blood, however, its chemical properties were not precisely examined in detail because of the limited quantity available. In this study, we used chemically defined liquid medium to culture Candida spp. and collected the water soluble fraction, CAWS. The yield of CAWS was circa 100 mg/l, independent of the strain of Candida. CAWS reacted with limulus factor G (Fungitec G test MK) at concentrations as low as 100 ng/ml. Limulus factor G reactivity of CAWS was sensitive to (1-->3)-beta-glucanase, zymolyase and was, at least in part, bound to ConA-agarose. The ConA-bound fraction also reacted with anti-beta-glucan antibody. CAWS is mainly composed of mannan and (1-->6)-beta-glucan, in addition to protein, assessed by 1H-NMR spectroscopy. CAWS also reacted with typing sera of Candida spp., specific for cell wall mannan. Chemical, immunochemical and biochemical analyses of CAWS strongly suggested that the limulus factor G-activating substance was a mannan-beta-glucan complex, present within the architecture of the yeast cell wall.

Candida↗
PubMed1999

Solubilization of yeast cell-wall beta-(1-->3)-D-glucan by sodium hypochlorite oxidation and dimethyl sulfoxide extraction.

The limulus test is a well-established method for the diagnosis of both Gram-negative sepsis and invasive fungal infection. To diagnose fungal infections, a beta-(1-->3)-D-glucan-specific chromogenic kit (Fungitec G test MK) has been developed and applied clinically. We are concentrating our main efforts on developing a better standard to improve the precision of this method. To this end, we have successfully developed a protocol to obtain a soluble Candida spp. beta-(1-->3)-D-glucan (CSBG) by sodium hypochlorite (NaClO) oxidation and subsequent dimethyl sulfoxide (Me2SO) extraction (yield of 9.6 +/- 4.1%) of acetone-dried whole-cell preparations. The beta-glucan fraction is free from the cell-wall mannan, gives a symmetrical peak by gel filtration, and is soluble in dilute NaOH. The product is composed mainly of beta-(1-->3)- and beta-(1-->6)-D-glucosidic linkages. The specific activity of the beta-glucan is comparable with pachyman when combined with the Fungitec G test as the standard glucan and reacted as low as 10(-11) g/mL.

Candida↗
PubMed1999

Preoperative cervical cytology in endometrial carcinoma and its clinicopathologic relevance.

OBJECTIVE: The aim of this study was to assess the significance of malignant or suspicious cervical cytology in preoperative identification of poor prognostic factors in endometrial carcinoma and to determine whether preoperative abnormal cervical cytology is an independent prognostic factor for endometrial carcinoma. METHODS: We evaluated the correlation between preoperative cervical cytology and postoperative clinicopathologic findings, sites of metastasis, and receptor status from 99 surgically staged patients with endometrial carcinoma. RESULTS: Sixty-eight patients (68.7%) had normal cervical cytology, 1 (1.0%) had atypical cytology suspicious for malignancy, and 30 (30.3%) had malignant cytology on preoperative cervical cytology. Malignant and suspicious cervical smears were statistically correlated with surgical stage (P = 0.001), histopathology (P = 0.010), tumor grade (P = 0.012), depth of myometrial tumor invasion (P = 0.001), cervical involvement (P = 0. 01), lymph node metastases (P = 0.002), adnexal metastases (P = 0. 012), progesterone receptor (P = 0.007), and estrogen receptor (P = 0.031). No association was found between preoperative cervical cytology and patients' age or peritoneal cytology. Univariate analysis showed that cervical cytology was related to survival (P = 0.018). However, multivariate analysis of cervical cytology, stage, grade, and myometrial invasion showed that preoperative cervical cytology was not a significant prognosticator for survival. CONCLUSION: Patients with endometrial carcinoma who have malignant or suspicious cytology detected by preoperative cervical cytology are at increased risk of having known poor prognostic factors. However, positive preoperative cervical cytology itself does not appear to be an independent prognostic factor and probably should not influence treatment decisions in endometrial cancer.

Adult↗
PubMed1999

Prognostic significance of progesterone receptor immunohistochemistry for lymph node metastases in endometrial carcinoma.

OBJECTIVE: The aim of this study was to determine whether progesterone receptor (PR), estrogen receptor (ER), p53 protein, and proliferating cell nuclear antigen (PCNA) expression constitute independent prognostic factors for lymph node metastases in endometrial carcinoma using immunohistochemical techniques on hysterectomy and biopsy specimens. METHODS: We evaluated the correlation between lymph node metastases and PR/ER immunohistochemistry, p53/PCNA expression, age, tumor grade, myometrial tumor invasion, cervical involvement, and ovarian metastases in a series of 99 cases of primary endometrial carcinoma surgically staged with systemic pelvic lymphadenectomy and para-aortic lymph node biopsy. RESULTS: Lymph node metastases from endometrial carcinoma were statistically correlated with negative PR immunohistochemistry (P = 0.001), intense p53 expression (66% or more of the tumor cells stained, P = 0.003), deep myometrial tumor invasion (greater than one-half, P = 0.001), and cervical involvement (P = 0.001). Tumor grade showed borderline statistical significance for lymph node metastases (P = 0.058). On multivariate analysis, negative PR, intense p53 expression, and cervical involvement were significant prognostic variables for lymph node metastases (P = 0.0001, 0.0023, and 0.002, respectively). Immunohistochemical study indicated that the PR status on preoperative biopsy specimens and hysterectomy specimens was in good agreement, but p53 status was not. Age, ovarian metastases, ER immunohistochemistry, and PCNA expression were not significantly related to lymph node metastases. CONCLUSION: PR immunohistochemistry appeared to be the most powerful prognostic factor associated with lymph node metastases in endometrial carcinoma, independent of other clinicopathological parameters.

Adult↗
PubMed1999

Identification of 1-aminocyclopropane-1-carboxylic acid synthase genes controlling the ethylene level of ripening fruit in Japanese pear (Pyrus pyrifolia Nakai).

The shelf life of Japanese pear fruit is determined by its level of ethylene production. Relatively high levels of ethylene reduce storage potential and fruit quality. We have identified RFLP markers tightly linked to the locus that determines the rate of ethylene evolution in ripening fruit of the Japanese pear. The study was carried out using sequences of two types of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase genes (PPACS1 and pPPACS2) and a ACC oxidase gene (PPAOX1) as probes on 35 Japanese pear cultivars expressing different levels of ethylene (0.0 to approximately 300 microl/kg fresh weight/h) in ripening fruit. When total DNA was digested with HindIII and probed with pPPACS1, we identified a band of 2.8 kb which was specific to cultivars having very high ethylene levels (> or = 10 microl/kg f.w./h) during fruit ripening. The probe pPPACS2 identified a band of 0.8 kb specific to cultivars with moderate ethylene levels (0.5 microl/kg f.w./h-10 microl/kg f.w./h) during fruit ripening. The cultivars that produce high levels of ethylene possess at least one additional copy of pPPACS1 and those producing moderate levels of ethylene have at least one additional copy of pPPACS2. These results suggest that RFLP analysis with different ACC synthase genes could be useful for predicting the maximum ethylene level during fruit ripening in Japanese pear.

Amino Acid Oxidoreductases↗
PubMed1999

Hypercholesterolemia and glomerular diseases in urinary screening of school children.

Although hypercholesterolemia frequently accompanies nephrotic syndrome, high serum total cholesterol (TC) levels are occasionally seen in children with non-nephrotic glomerular diseases. However, little is known of the significance, if any, of these elevated serum TC levels in non-nephrotic glomerular diseases. During the past 5 years, a total of 256,179 school children received yearly urinary screening at school for renal diseases and 1,702 children (0.66% of the total, although 174 children dropped out) had proteinuria and/or hematuria. Using the data obtained from the 1,528 children, we studied whether there is any association between serum TC levels and the presence of glomerular diseases. The detection rate of glomerular diseases (IgA nephropathy, membranoproliferative glomerulonephritis, focal segmental glomerular sclerosis, etc.) in the subjects with high serum TC levels (> or =200 mg/dl) was significantly higher (16 of 161, 9.94%, P<0.001) than in those with normal serum TC levels (<200 mg/dl) (10 of 1,367, 0.73%). There were no significant differences in serum albumin and blood urea nitrogen levels between the two groups. We conclude that children with chance proteinuria and/or hematuria may be at higher risk for glomerulonephritis of various types when they have unexplained hypercholesterolemia, and that measurement of serum cholesterol levels may be useful in urinary screening for renal diseases.

Adolescent↗
PubMed1999

Apolipoprotein E epsilon 4 allele and nephrotic glomerular diseases in children.

Hyperlipidemia is a well-recognized complication of the nephrotic syndrome and is a factor contributing to the progression of the initial glomerular injury and the development of glomerulosclerosis. Apolipoprotein E (apoE) is a plasma protein and apoE epsilon 4 allele is associated with higher plasma cholesterol levels. With this in mind, we studied apoE phenotypes and alleles in children with nephrotic glomerular diseases (NGD, n=29), including idiopathic nephrotic syndrome (n=16), membranoproliferative glomerulonephritis (n=7), and focal segmental glomerulosclerosis (FSGS, n=6). Children with NGD had a higher epsilon 4 allele frequency (20.7%) than controls (10.8%), and those with FSGS had both higher apoE4/3 (66.7%) and epsilon 4 allele (33.3%) frequencies than controls (20.4% and 10.8%, respectively). In IgA nephropathy (n=30, disease controls), no significant association with specific apoE was found. Further studies are needed to clarify the significance of the observed high frequencies of apoE epsilon 4 allele in children with NGD and apoE4/3 phenotype distribution in FSGS.

Adolescent↗
PubMed1999

Inflammatory and immunopharmacological activities of meta-periodate oxidized zymosan.

Zymosan (ZYM), a strong complement-activating yeast cell preparation composed mainly of mannan and beta-glucan moieties, is a potent inflammatory substance with immunopharmacological activity. We previously analyzed the metabolism of ZYM in mice and found that it was deposited in liver and spleen for at least several months and then gradually oxidatively degraded. In this paper, we prepared oxidized ZYM by sodium metaperiodate oxidation (NaIO4) and borohydride reduction (I/B-ZYM) and/or limited hydrolysis of oxidized moieties (I/B/H-ZYM). Activities of the resulting products were assessed by (i) vascular permeability in mice, (ii) H2O2 synthesis by macrophages, (iii) TNF-alpha synthesis by macrophages, and (iv) reactivity to anti-ZYM sera. As a general trend, NaIO4, oxidation products exhibited reduced, but still significant, activity. Interestingly, the H2O2 production induced by I/B/H-ZYM was significantly reduced after extensive sonication. Antagonist(s) for H2O2 synthesis were concomitantly solubilized by sonication of I/B/H-ZYM. On the contrary, TNF-alpha production induced by I/B/H-ZYM was comparable with that of ZYM. These facts strongly suggest that highly branched 1,3-beta- and 1,6-beta-glucosidic linkages resistant to NaIO4 oxidation are important for biological activity of ZYM. Further, the minimal structure in ZYM necessary for biological activity may depend on the activity tested.

Animals↗
PubMed1999

Serum lipoproteins and apolipoprotein E in infants with congenital hypothyroidism.

BACKGROUND: Hypothyroid adults have a high risk of atherosclerosis, secondary to increased levels of various cholesterol fractions, particularly low-density lipoprotein cholesterol (LDL-C). We investigated the existence of a correlation between thyroid hormone deficiency and serum lipoproteins and a possible effect of different apolipoprotein E (apoE) phenotypes on lipoprotein levels in 75 infants with hypothyroidism. METHODS: Seventy-three of the 75 infants had congenital hypothyroidism. At the age of one month, prior to the initiation of thyroid hormone substitution therapy, thyroid-stimulating hormone (TSH), thyroid hormones and lipid profile parameters were determined. Subsequently, apoE phenotyping in all patients was performed by isoelectric focusing followed by immunoblotting. RESULTS: Significant negative correlations were identified between triiodothyronine (T3) and LDL-C and total cholesterol (TC) levels and between thyroxine (T4) and TC levels. There were no correlations between TSH and free (F)T4 and lipid profile parameters. Although infants carrying at least one E4 allele had higher LDL-C (as well as TC and triglyceride) levels than those carrying at least one E2 allele, these differences were not statistically significant. No significant differences in thyroid hormones were noted in E4 allele carriers in comparison with other patients. CONCLUSIONS: The observed lack of a significant correlation between thyroid hormones (except T3), apoE phenotypes and lipoprotein levels suggests that, early in infancy, other factors may play a more important role in determining lipoprotein levels.

Adult↗
PubMed1999

Thyroxine inversely regulates serum intermediate density lipoprotein levels in children with congenital hypothyroidism.

BACKGROUND: Although there have been numerous studies on the effects of thyroid hormones on serum lipid profiles, the effects of thyroxine on intermediate how density lipoprotein (IDL) remain uncertain. In an attempt to clarify, this issue, under conditions with very little influence exerted by sex hormones on serum lipid profiles, we studied the relationship between serum thyroid hormone levels and the proportion of serum IDL fractions in children. METHODS: Nineteen children with congenital hypothyroidism and 13 children with non-thyroid diseases were enrolled in this study. Blood samples were taken to measure serum thyroid stimulating hormone, triiodothyronine, free thyroxine (FT4), total cholesterol, high density lipoprotein (HDL) cholesterol, triglyceride and apolipoprotein levels. Lipoprotein fractions, including very low density lipoprotein (VLDL), IDL, low density lipoprotein (LDL) and HDL, were determined by their electrophoretic mobility in a non-denaturing polyacrylamide gel. RESULTS: The proportion of IDL fractions showed a significant inverse correlation with serum FT4 levels and a significant correlation with serum total cholesterol and apolipoprotein B and C-II levels. Serum VLDL, LDL and HDL fractions did not correlate with serum thyroid hormone levels. CONCLUSION: From these results and other studies, we suggest that thyroxine promotes the conversion of IDL into LDL, possibly by its stimulatory effects on hepatic lipase activity.

Apolipoproteins↗
PubMed1999

A study of therapy for pediatric hepatoblastoma: prevention and treatment of pulmonary metastasis.

Our results of treatment for pediatric hepatoblastoma are presented with special emphasis on pulmonary metastasis. The pulmonary metastasis rate of hepatoblastoma was 44% (11/25). In 19 patients with resected hepatoblastomas, the 5-year survival rate without pulmonary metastasis was 90% (9/10); while with pulmonary metastasis it was 22% (2/9). Six patients with unresected hepatoblastomas all died within 4 months regardless of chemotherapy and/or metastasis. To improve survival in patients with hepatoblastoma, preoperative or postoperative chemotherapy was thought to be essential for tumors extending over 2 hepatic segments and having predictable factors for pulmonary metastasis (large size or histological evidence of capsular invasion). A long-term multidisciplinary approach including hepatic lobectomy, current multiagent chemotherapy (including CDDP, THP-ADR), and partial pulmonary resection for localized lung areas with metastases would ultimately be needed.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Sacrococcygeal teratoma: a series of 19 cases with long-term follow-up.

A series of 19 cases of sacrococcygeal teratoma (SCT) with follow-up of 5 to 25 years is presented. Twelve patients were neonates, age 0 to 26 days (5 immature teratomas and 7 mature teratomas, representing 3, 6, 2, and 1 Altman's type I, II, III, and IV tumors, respectively), four were infants, age 1 to 6 months (all mature teratomas, representing 1, 1, and 2 Altman's type I, II, and IV tumors), and 3 were children, age 1 to 4 years (all malignant teratomas, all Altman's IV tumors). Eight babies were delivered by elective caesarean section (CS). Though the mean gestational age at CS was 34.3 weeks in our series, we now believe that CS often must be performed earlier, depending on a tumor size or fetal condition. Eleven neonates and 4 infants were operated upon using a sacral approach in 10 and an abdominosacral approach in 5, and all survived. However, 4 patients had neurogenic bladder and were treated by urinary catheterization or vesicostomy for 2 to 5 years after surgery. Postoperative urogenital sequelae are seen in patients with a large tumor, urethral compression, urinary retention, or edema of the lower body. Malignant tumors usually had metastasized by the time of diagnosis, but the prognosis for outcome has been improved following surgery and combination chemotherapy.

Adolescent↗
PubMed1999

Effects of xenon on the performance of various respiratory flowmeters.

BACKGROUND: The anesthetic gas xenon has distinctly different physical properties compared with air, nitrous oxide, or oxygen. This led us to predict that xenon would affect the performance of commercially available flowmeters. METHODS: Flow was generated by an anesthesia ventilator connected to a lung simulator via a semiclosed breathing circuit. With the system filled with air or with various concentrations of xenon or nitrous oxide in a balance of oxygen, the tidal volume was measured with two rotating vanes, a Pitot tube, a variable-orifice flowmeter, and two constant-temperature hot-wire flowmeters. RESULTS: Although xenon minimally affected both rotating vane flowmeters, it caused the Pitot tube and the variable-orifice flowmeters to overread in proportion to the square root of the density of the gas mixture used (xenon is 4.6 times more dense than air). In contrast, the hot-wire anemometers underread with xenon; for example, their readings in the presence of 45% and 70% xenon were less than 10% of those displayed when air was used. Nitrous oxide minimally affected all the flowmeters except the variable-orifice device. The Pitot flowmeter was also affected, but only when its gas analyzer port was open to the ambient air so that it no longer corrected its readings for changes in gas composition. In these cases, nitrous oxide produced overreadings in the same manner as did xenon. CONCLUSION: Among the four types of flowmeters studied, only the rotating-vane type is sufficiently accurate for use during anesthesia with xenon.

Anesthetics, Inhalation↗
PubMed1999

Melatonin rhythms in delayed sleep phase syndrome.

The aim of this study was to compare circadian and sleep characteristics between patients with delayed sleep phase syndrome (DSPS) and healthy controls. The authors studied 8 DSPS patients and 15 normal controls. Serum melatonin concentration was assessed every hour for 24 h under dim light conditions. The sleep phase and the melatonin rhythm in DSPS patients were significantly delayed compared to those in normal controls. Sleep length was significantly greater in DSPS patients compared to that in controls, but the duration of melatonin secretion did not differ between the two groups. The final awakening, relative to melatonin onset, melatonin midpoint, and melatonin offset, was significantly longer in DSPS patients than in controls. By contrast, the timing of sleep onset relative to melatonin rhythm did not differ between the two groups. The authors found a significant positive correlation between sleep phase markers and melatonin phase markers in DSPS. They postulate that a delayed circadian pacemaker may be responsible for delayed sleep phase syndrome. The alteration of phase angle between melatonin rhythm and sleep phase suggested that not only the delay of the circadian clock but also a functional disturbance of the sleep-wake mechanism underlies DSPS.

Adolescent↗
PubMed1999

Neurogenic vasodilatation of canine isolated small labial arteries.

Mechanisms underlying vasodilatation to nerve stimulation by electrical pulses and nicotine were analyzed in isolated canine small labial arteries. Transmural electrical stimulation (5 and 20 Hz) produced a contraction followed by a relaxation in labial arterial strips denuded of the endothelium, partially contracted with prostaglandin F2alpha. The contraction was abolished by prazosin or combined treatment with alpha, beta-methylene ATP. In the treated strips, neurogenic relaxation was abolished by NG-nitro-L-arginine (L-NA), a nitric oxide (NO) synthase inhibitor, and restored by L-arginine. The D-enantiomers were without effect. Nicotine (10(-4) M) also relaxed the arteries, in which the contractile response was abolished by prazosin and alpha, beta-methylene ATP. The relaxant response was attenuated but not abolished by L-NA; the inhibition was reversed by L-arginine. The remaining relaxation by nicotine was abolished by calcitonin gene-related peptide (CGRP)-[8 to 37], a CGRP1 receptor antagonist. Relaxations elicited by a lower concentration of nicotine (2 x 10(-5) M) sufficient to produce similar magnitudes of response to those induced by 5-Hz electrical nerve stimulation were also inhibited partially by L-NA. Histochemical study with the NADPH-diaphorase method demonstrated positively stained nerve fibers and bundles in the arterial wall, suggesting the presence of neuronal NO synthase. It is concluded that the relaxation induced by electrical nerve stimulation of small labial arteries is mediated exclusively by NO synthesized from L-arginine in nerve terminals, whereas nicotine in the concentrations used evokes relaxations by a mediation of nerve-derived NO and also CGRP, possibly from sensory nerves. The reason why nicotine but not electrical pulses stimulates sensory nerves and elicits vasorelaxation remains unsolved.

Animals↗