Sensitive determination of bisphenol A and alkylphenols by high performance liquid chromatography with pre-column derivatization with 2-(4-carboxyphenyl)-5,6-dimethylbenzimidazole

A new and sensitive high-performance chromatographic method for the determination of bisphenol A and 8 alkylphenols with fluorescence detection is reported. Each phenol was derivatized by reaction with 2-(4-carboxyphenyl)-5,6-dimethylbenzimidazole at 40 degrees C for 60 min. The fluorescence derivatives were separated on a Wakosil 5C18 column (4.0 i.d. x 300 mm, 5 microm) with methanol:water (10:90) as mobile phase (detection wavelength: lambda(ex) 336 nm, lambda(em) 440 nm). The detection limits were in the range of 0.1-10.0 pg/mL in serum. The calibration graphs were linear to 1.0 microg/mL. The relative standard deviations were 7.2-8.9%, respectively. The proposed method was applied to the determination of bisphenol A in mother and infant rat serum.

Fat-suppressed T2-weighted MRI of the liver: comparison of respiratory-triggered fast spin-echo, breath-hold single-shot fast spin-echo, and breath-hold fast-recovery fast spin-echo sequences

The purpose of our study was to compare the value of respiratory-triggered fast spin-echo, breath-hold single-shot fast spin-echo, and breath-hold fast-recovery fast spin-echo sequences in detecting hepatic lesions. Fat-suppressed T2-weighted magnetic resonance (MR) images obtained with the three sequences in 36 patients with 138 lesions and nine patients without lesions were prospectively analyzed. Quantitative and qualitative analyses, including receiver operating characteristic (ROC) analyses, were performed. The mean lesion-to-liver contrast-to-noise ratio (CNR) for hepatic lesions was highest with the respiratory-triggered fast spin-echo sequence. On the basis of receiver-operating characteristic analyses, tumor detection rates were higher with the breath-hold fast-recovery fast spin-echo sequence (Az = 0.94) than with the respiratory-triggered fast spin-echo sequence (AZ = 0.80, P < 0.0001) or the single-shot fast spin-echo sequence (Az = 0.77, P < 0.0001). The image quality with the breath-hold fast-recovery fast spin-echo sequence was acceptable in all patients. The breath-hold fast-recovery fast spin-echo sequence provided the highest tumor detection in a short imaging time, although the mean lesion-to-liver CNRs were inferior to those of the respiratory-triggered fast spin-echo and the breath-hold single-shot fast spin-echo sequences.

Changes in myometrial and junctional zone thickness and signal intensity: demonstration with kinematic T2-weighted MR imaging

PURPOSE

To demonstrate uterine contractions by evaluating changes during time in the thickness of the myometrium and junctional zone and in signal intensity of the uterus with T2-weighted fast magnetic resonance (MR) images in a kinematic fashion.

MATERIALS AND METHODS

Sagittal MR imaging was performed with T2-weighted fast spin-echo (FSE) and multiphase-multisection single-shot FSE (SSFSE) in 60 premenopausal patients during free breathing. SSFSE MR images were evaluated with cine display. The pattern of uterine contractions and changes in signal intensities of the uterine structures were evaluated. Thickness of both myometrium and junctional zone, and their signal intensities, were measured during 15 phases of SSFSE and FSE MR imaging.

RESULTS

Slow-massive (mean, 55%), middle-cycle (mean, 80%), and fine (mean, 93%) contractions were observed. Shape of junctional zones dynamically changed during time, showing focal (mean, 58%) and diffuse (mean, 82%) thickening and wavelike motions (mean, 88%). Ratio of thickness of the myometrium to junctional zone with FSE MR imaging was not significantly different from the mean ratio during 15 phases of SSFSE MR imaging, although maximum percentage of change of the ratio during 15 phases was 42.5%-56.8%. The signal intensities of the myometrium (97%) and junctional zone (75%) changed during time.

CONCLUSION

Kinematic T2-weighted SSFSE MR images demonstrate uterine contractions related to dynamic changes in thickness and signal intensities of the myometrium and junctional zone, and these findings might affect the diagnosis of uterine disease.

Functional assessment of pancreatic parenchyma after secretin administration using serial T2-weighted echo-planar magnetic resonance imaging

Signal intensity (SI) changes of pancreatic parenchyma were evaluated after intravenous administration of secretin using T2-weighted single-shot spin-echo echo-planar imaging (EPI) to assess this method as a magnetic resonance (MR) test of pancreatic exocrine function. Nine volunteers were studied with serial single-shot EPI of the pancreas for 15 minutes after the injection of secretin or saline. The normal pattern of pancreatic SI change was demonstrated after intravenous injection of secretin, a single peak at 3-4 minutes in the head, body, and tail, followed by a gradual decrease in SI. Saline injection did not induce a significant SI change. There was no statistical difference in the peak contrast ratios (first mean, 1.21-1.25, vs. second mean, 1.18-1.22) and peak times (first mean, 3.2-3.7 minutes, vs. second mean, 3.1-3.6) in a repeat study. By evaluating the pattern of time-response curves obtained from serial T2-weighted EPI after secretin injection, pancreatic exocrine function may be directly assessed at the level of the head, body, and tail.

Simultaneous determination of six adenyl purines in human plasma by high-performance liquid chromatography with fluorescence derivatization

A sensitive method was developed for the simultaneous determination of six adenyl purines in human plasma by high-performance liquid chromatography. The adenyl purines (adenine, adenosine, AMP, ADP, ATP and cyclic AMP) were derivatized using 2-chloroacetaldehyde for fluorescence detection, and the reaction and separation conditions were reinvestigated to improve sensitivity for small volume sample analysis. Each derivatized purine was separated on a Capcell Pack SG120A column with mobile phase consisting of 0.05 M citric acid-0.1 M dipotassium hydrogen phosphate (pH 4.0)-methanol (97+3). The detection limits were 100-1000 fmol/ml by fluorescence detection, some 500 times better than previous reports. The proposed method was applied to determine adenyl purines in human plasma. The purine levels were as follows: ATP (9.2-22.2 pmol/ml), ADP (5.5-22.2 pmol/ml), AMP (0.8-3.2 pmol/ml). Other purines, adenine, adenosine, cAMP were lower than 0.1 pmol/ml.

Identification of cardiac abnormal structures with harmonic power Doppler contrast echocardiography

We describe two cases in which echocardiographic image enhancement with an intravenous contrast agent using harmonic power Doppler (HPD) imaging established the diagnosis of abnormal structures in the left ventricle (LV).

Evaluation of pelvic adhesions using multiphase and multislice MR imaging with kinematic display

OBJECTIVE

The purpose of this study was to evaluate whether kinematic multiphase and multislice MR imaging could reveal pelvic adhesions.

SUBJECTS AND METHODS

Before surgery, 52 women with gynecologic disorders underwent half-Fourier acquisition single-shot fast spin-echo imaging with multiphase and multislice acquisitions. Images were displayed in a cine mode, and the motion of each organ against adjacent organs was evaluated by two radiologists who were unaware of the patients' histories or of the findings of their clinical examinations or surgeries. Findings from MR imaging were classified into three types relative to the adjacent organs: type 1, sliding, defined as organs moving 1 cm or more; type 2, fine motion, defined as organs moving less than 1 cm; or type 3, no motion. Type 2 was further subdivided into two groups: type 2-A, independent fine movement, and type 2-B, synchronous fine movement. All MR imaging findings were verified by laparotomy or laparoscopy. Peristalsis at the rectum, colon, and small intestine were also evaluated.

RESULTS

A total of 317 interfaces were evaluated. For findings of type 1 (n = 8 interfaces) and type 2-A (n = 245) on kinematic MR imaging, the negative predictive values for adhesions were 100% and 95.5%, respectively. Findings of type 2-B (n = 52) and type 3 (n = 12) with no adhesions were observed in 40.4% and 66.7%, respectively. When type 1 and type 2-A were regarded as negative findings of adhesions, and type 2-B and type 3 as positive, sensitivity, specificity, and accuracy were 72.5%, 87.4%, and 85.4%, respectively. Peristalsis was observed in 69.2% of patients at the rectum, 86.5% at the colon, and 100% at the small intestine.

CONCLUSION

Multiphase and multislice MR imaging with kinematic display may provide new information about the presence of pelvic adhesions.

[Pulmonary hypertension in patients with connective tissue diseases]

Pulmonary hypertension (PH) is said to be frequently associated with connective tissue diseases (CTD). The national surveillance of CTD associated PH (CTD-PH) by the study groups of the Ministry of Health and Welfare (MHW) revealed that mixed connective tissue disease (MCTD) had the highest incidence of PH (5.02%), next to systemic sclerosis (SSc) (2.64%). Patients with CTD-PH could be divided into two groups according to the prognosis: poor prognosis group and fairly good prognosis group. Poor prognosis was associated statistically with polyarthritis and high level of CK. Treatment of CTD-PH was still difficult, but adrenocoticosteroids could be tried in some patients, and drip infusion therapy of prostacyclin seemed very promising, but it has not been accepted by the MHW so far.

T2-weighted MRI of the female pelvis: comparison of breath-hold fast-recovery fast spin-echo and nonbreath-hold fast spin-echo sequences

In 49 patients who had pelvic abnormalities, breath-hold T2-weighted fast-recovery (FR)-fast spin-echo (FSE) (imaging time = 24 sec) and nonbreath-hold FSE MR images (2 min 8 sec) were compared qualitatively (on a four-point scale) and quantitatively (using signal-to-noise ratios (SNRs) and contrast ratios (/SIs of the lesions-SIs of the myometrium/SIs of the myometrium)). Motion artifacts were reduced on breath-hold FR-FSE (3.8:3.2 = breath-hold FSE:nonbreath-hold FSE, P < 0.01) and image quality was comparable (3.8:3.7, NS). In all patients, pathology (leiomyoma [N = 26], adenomyosis [N = 10], endometrial carcinoma [N = 8], and ovarian cystic lesions [N = 21]) was recognized with comparable lesion conspicuity (3.8:3.7, NS) and better delineation of the structures (3.9:3.6, P < 0.05) on the FR-FSE images. There was no significant difference in contrast ratios, although SNRs (e.g., myometrium 18.3:25.8, P < 0.01) were better and the uterine zonal anatomy was recognized better on the nonbreath-hold FSE (3.4:3.7, P < 0.05). These differences did not affect the diagnosis. Breath-hold FR-FSE provides the benefits of motionless imaging and a short examination time, although lower SNRs were noted. J. Magn. Reson. Imaging 2001;13:930-937.

[A case of intrasellar meningioma mimicking pituitary adenoma]

The authors report a patient with a rare intrasellar meningioma mimicking pituitary adenoma. A 60-year-old man was admitted to our hospital for evaluation of general fatigue. He had no neurological deficit including visual function. Endocrinological tests revealed panhypopituitarism. The craniogram showed slight enlargement of the sella turcica with thinning of the dorsum sellae. CT scan and MR imaging demonstrated a homogeneously enhanced intrasellar mass with slight suprasellar extension. Partial removal of the mass was performed via the transsphenoidal approach because it was extremely firm and hemorrhagic. Histological diagnosis was transitional meningioma. The patient has been well for two years after surgery without tumor progression on MR imaging. It is mandatory to distinguish intrasellar meningioma from pituitary adenoma preoperatively because of marked difference in their treatment strategies. Despite recent advances in neurodiagnostic imaging, it may still be difficult to differentiate pituitary adenoma from intrasellar meningioma. When we re-evaluated the MR imaging, we recognized that the tumor had demonstrated specific findings, ruling out pituitary adenoma, namely bright and homogeneous enhancement, dense enhancement in the early phase on the dynamic MR study, and flow void signal within the mass. The authors emphasize that careful evaluations of MR imaging will allow the correct preoperative diagnosis in patients with intrasellar meningioma mimicking pituitary macroadenoma.

Suppression of occurrence and advancement of beta-catenin-accumulated crypts, possible premalignant lesions of colon cancer, by selective cyclooxygenase-2 inhibitor, celecoxib

Suppression of occurrence and advancement of premalignant lesions is important for cancer prevention. Our previous studies clarified that beta-catenin-accumulated crypts, independent of aberrant crypt foci (ACF), are probably direct precursors of colon cancers in rats. Here we investigated the effects of a selective cyclooxygenase-2 inhibitor, celecoxib, on the development of beta-catenin-accumulated crypts in comparison with those on ACF. Male F344 rats were divided into 4 groups. Groups 1 - 3 were administered azoxymethane (AOM) s.c. at a dose of 15 mg / kg body weight, once weekly for 3 weeks to induce beta-catenin-accumulated crypts. Groups 2 and 3 also received experimental diet containing celecoxib (500 and 1500 ppm, respectively) for 8 weeks, starting a week before the first dosing of AOM. At termination, the frequency and crypt multiplicity (number of crypts / lesion) of beta-catenin-accumulated crypts of groups 2 and 3 were significantly less than that of group 1. Furthermore, numbers of silver-stained nucleolar organizer regions (AgNORs) / nucleus in beta-catenin-accumulated crypts were also decreased by exposure to celecoxib. In this study, celecoxib had greater effects on the frequency and growth of beta-catenin-accumulated crypts than on those of ACF. These findings represent additional evidence that beta-catenin-accumulated crypts are premalignant lesions of colon cancer. The results also suggest that beta-catenin-accumulated crypts could be a novel target for evaluation of possible chemopreventive agents against colon carcino-genesis, and indicate that possible chemopreventive effects of celecoxib on the initial stage of colon carcinogenesis may be related to modulation of cell proliferation activity in such early lesions.

Effects of dermatan and dextran sulfates on arginine amidase activity released from isolated rabbit arteries

We examined the levels of arginine amidase secreted from isolated rabbit arteries treated with dermatan and dextran sulfates, and the relation between the secretion of arginine amidase activity and the concentration of dermatan sulfate added to these arteries. The results showed that while dextran sulfate tended to accelerate the release of arginine amidase activity from the isolated rabbit ear artery, the induction was not significant. There was a significant increase in the level of arginine amidase released from the lower portion of isolated rabbit aorta (p<0.05), but no significant change in the upper portion of the aorta. In contrast, the addition of dermatan sulfate significantly increased the level of arginine amidase activity released from the isolated rabbit ear artery and the upper and lower portions of the aorta (p<0.05). Linear dose-response relationships were observed between the level of arginine amidase activity released from the isolated rabbit ear artery and aorta and the concentration of dermatan sulfate added.

KL-6 as a novel marker for activities of interstitial pneumonia in connective tissue diseases

The objective of this study was to determine the role of serum KL-6 levels as a marker for the activity of interstitial pneumonia in patients with connective tissue diseases. The serum concentrations of KL-6, a glycoprotein produced mainly by pulmonary type II epithelial cells, were measured in 21 patients with connective tissue disease. The activity of interstitial pneumonia was compared with the associated serum KL-6 concentrations. Serum KL-6 concentrations in patients with interstitial pneumonia were significantly higher than those in the controls. Among patients with active interstitial pneumonia, serum KL-6 concentrations following the treatment (after improvement) were significantly lower than the pretreatment values. The extent of the pulmonary fibrosis correlated positively with the serum KL-6 concentrations during the inactive phase of the interstitial pneumonia. These results suggest that sequential measurement of serum KL-6 levels is a new and useful means for the evaluation of interstitial pneumonia in patients with connective tissue diseases.

Sequential analysis of morphological and biological properties of beta-catenin-accumulated crypts, provable premalignant lesions independent of aberrant crypt foci in rat colon carcinogenesis

Our previous study (Cancer Res., 60: 3323-3327, 2000) showed that frequent beta-catenin gene mutations are present in beta-catenin-accumulated crypts, which occur early in rodent colonic carcinogenesis, with a lack of the appearance of aberrant crypt foci (ACF). To clarify the nature of such lesions, we performed a sequential analysis of the morphological and biological properties of beta-catenin-accumulated crypts. Azoxymethane was administered s.c. to male F344 rats (15 mg/kg body weight) once a week for 3 weeks, and the animals were sacrificed at 5, 10, and 20 weeks after the carcinogen treatment. Both the number of crypts/lesion and the diameter of beta-catenin-accumulated crypts were significantly increased with time courses of 5, 10, and 20 weeks from carcinogen exposure (P < 0.01). Likewise, the histological abnormality in those crypts, assessed by semiquantitative analyses, was also increased with time (P < 0.01). Conversely, ACF did not show any increase in histological abnormality during the time course and maintained a monotonous histology throughout the experiment. The histological abnormality score for beta-catenin-accumulated crypts was significantly higher than for ACF at every time point (P < 0.001). The number of AgNOR/nucleus in beta-catenin-accumulated crypts was significantly higher than in ACF (P < 0.001). Beta-catenin-accumulated crypts were accompanied frequently by Paneth cells and had decreased hexosaminidase activity. Such data, together with the results in our previous report, strongly suggest that beta-catenin-accumulated crypts, which are independent of ACF, are truly premalignant lesions for colon cancer.

The inhibitory effects of mangiferin, a naturally occurring glucosylxanthone, in bowel carcinogenesis of male F344 rats

Mangiferin, 1,3,6,7-tetrahydroxyxanthone-C2-beta-D-glucoside, is one of xanthone derivatives and C-glucosylxanthones, is widely distributed in higher plants and is one of constituents of folk medicines. Recent studies showed that mangiferin has a potential as an anti-oxidant and an anti-viral agent. In this study, we examined the effects of mangiferin in rat colon carcinogenesis induced by chemical carcinogen, azoxymethane (AOM). We performed two experiments: a short-term assay to investigate the effects of mangiferin on the development of preneoplastic lesions by AOM, aberrant crypt foci (ACF), and the following long-term assay for the influence of mangiferin on tumorigenesis induced by AOM. In the short-term assay, 0.1% mangiferin in a diet significantly inhibited the ACF development in rats treated with AOM compared to rats treated with AOM alone (64.6+/-22.0 vs. 108.3+/-43.0). In the long-term assay, the group treated with 0.1% mangiferin in initiation phase of the experimental protocol had significantly lower incidence and multiplicity of intestinal neoplasms induced by AOM (47.3 and 41.8% reductions of the group treated with AOM alone for incidence and multiplicity, respectively). In addition, the cell proliferation in colonic mucosa was reduced in rats treated with mangiferin (65-85% reductions of the group treated with AOM alone). These results suggest that mangiferin has potential as a naturally-occurring chemopreventive agent.

Gadolinium-enhanced MR angiography in the evaluation of congenital cardiovascular disease pre- and postoperative states in infants and children

The purpose of this study was to evaluate the utility of dynamic contrast magnetic resonance (MR) angiography under sedation for assessing congenital cardiovascular disease in infants and small children before and after cardiac surgery. In 38 patients with cardiovascular abnormalities, thoracic vasculatures were evaluated in either the preoperative (group 1; 23 patients, median age 9 months old) or the postoperative (group 2; 15 patients median age 1. 3 years old) state using gadolinium-enhanced dynamic MR angiography. Acquired data were processed with a multiprojection volume reconstruction. Image quality (grades 1-5, undiagnostic to excellent), presence or absence of the extracardiac vasculature, its pathology (group 1), and the patency of the postsurgical shunt or reconstructed vasculature (group 2) were evaluated. All images were of diagnostic image quality (mean grade 4.4-3.2). Recognition of the thoracic vasculature was correctly made in all cases (38/38, 100%). In group 1, anomalies and pathologic changes were correctly identified in 22 of 23 cases (95.7%). In one patient with dextrocardia and the cardiac type of total anomalous pulmonary venous return, the abnormality was not recognized. In group 2, the patency of the shunt flow after Glenn (n = 6), modified Fontan (n = 4), Rastelli (n = 1), and Blalock-Taussig (n = 3) operations was well demonstrated in each case. The reconstructed pulmonary artery (n = 1), veins (n = 2), and aorta (n = 1) were correctly visualized. In one case, stenosis of the reconstructed left pulmonary vein was missed by MR angiography. In 14 of 15 cases in group 2 (93.3%), MR angiography correctly gave information on the operated areas. In conclusion, dynamic contrast MR angiography under sedation is useful for evaluation of the thoracic vasculature of infants and small children in the pre- and postoperative states. J. Magn. Reson. Imaging 2000;12:1034-1042.

Synthesis, absolute configuration and biological activity of both enantiomers of 2-(5,6-dichloro-3-indolyl)propionic acid: new dichloroindole auxins

Racemic 2-(5,6-dichloro-3-indolyl)propionic acid (5,6-Cl2-2-IPA) was synthesized from 5,6-dichloroindole-3-acetic acid (5,6-Cl2-IAA) by successive esterification, methoxycarbonylation, methylation, and double hydrolysis. The racemate was converted to the diastereomeric esters of (S)-(-)-1-phenylethyl alcohol. These were separated by HPLC into two optically active diastereomers and then hydrolyzed with p-TsOH to the optically active enantiomers of 5,6-Cl2-2-IPA. The absolute configurations of both the 5,6-Cl2-2-IPA enantiomers were determined by comparing the 1H-NMR spectra of their diastereomeric (S)-(-)-1-phenylethyl esters with those of the diastereomeric (S)-(-)-1-phenylethyl esters of 2-(3-indolyl)propionic acid (2-IPA) whose absolute configurations are already known. There was no essential difference between (S)-(+)- and (R)-(-)-5,6-Cl2-2-IPA in hypocotyl growth-inhibiting activity toward Chinese cabbage, but their inhibitory activities were stronger than that of the potent mother auxin, 5,6-Cl2-IAA. No essential difference in the coleoptile elongating activity of Avena sativa was apparent for the enantiomers, this activity being about one-third that of 5,6-Cl2-IAA.

Angiodysplasia of the appendix

Angiodysplasia of the gastrointestinal tract is thought to be one of the most common causes of lower gastrointestinal bleeding in the elderly, and, in the majority of cases, lesions are located in the cecum or ascending colon. The authors report an extremely rare case of appendicular angiodysplasia. A 76-yr-old woman was hospitalized with massive recurrent red anal bleeding. Selective superior mesenteric arteriography revealed an extravasation of contrast material from the appendicular artery, and this finding proved to be bleeding from an angiodysplasia of the appendix. An appendectomy was performed, and anal bleeding did not recur postoperatively. A review of the literature revealed this to be an extremely rare case of angiodysplasia.

Developmentally and regionally regulated expression of growth hormone secretagogue receptor mRNA in rat brain and pituitary gland

Distribution and development of growth hormone secretagogue receptor (GHS-R) mRNA expression in rat brain and pituitary gland were examined using ribonuclease protection assay. In adult male rats, GHS-R mRNA levels were highest in the pituitary gland, whereas those in the hypothalamus and hippocampus were 57 and 30% of those in the pituitary gland, respectively. Less abundant but detectable levels of GHS-R mRNA were found in the midbrain, pons, and medulla oblongata, but expression was barely detectable in the cerebellum and cerebral cortex. The expression of GHS-R mRNA was detected at late gestation (embryonic day 19) in the pituitary gland, hypothalamus, and brainstem. The mRNA levels increased with age in the pituitary gland, and decreased postnatally in the brainstem, while they remained constant in the hypothalamus during development. In contrast, GHS-R mRNA was not detectable in the hippocampus during the fetal period, but was first detected on postnatal day 7. Expression of GHS-R mRNA was also examined in the spontaneous dwarf rat (SDR), a model for isolated GH deficiency, to examine alterations in GHS-R mRNA expression in a GH-deficient state. GHS-R mRNA levels in the pituitary gland of SDRs were higher than those of control rats, suggesting negative regulation of GHS-R mRNA by GH in this region. GHS-R mRNA levels increased in the hypothalamus of female, but not in male SDRs. In contrast, GHS-R mRNA levels were not affected by GH in the brainstem and hippocampus. These results indicate that region-specific, developmentally regulated expression of GHS-R mRNA may reflect divergent physiological roles of GHS/GHS-R in distinct regions of the central nervous system and the pituitary gland.

Retinoic acids and thyroid hormone act synergistically with dexamethasone to increase growth hormone-releasing hormone receptor messenger ribonucleic acid expression

The effects of all-trans-retinoic acid (RA), 9-cis-retinoic acid (9cRA), and thyroid hormone (T3) on GH-releasing hormone receptor (GHRH-R) messenger RNA (mRNA) expression were studied using ribonuclease protection assay in the fetal rat pituitary gland and in MtT/S cells, a clonal GH cell line derived from an estrogen-induced somatotropic tumor in the rat. Although RA (1 microM), 9cRA (1 microM), or T3 (1 nM) alone showed little effect on GHRH-R mRNA expression in the MtT/S cells, each of these substances was found to act synergistically with dexamethasone (DEX; 500 nM) to increase GHRH-R mRNA expression. The effects of RAs and T3 were dose dependent, with maximum effects observed at 1 microM and 1 nM, respectively. The maximum effect of RAs or T3 was not further augmented by the addition of T3 or RAs, respectively. No apparent differences were observed in this study between the actions of RA and 9cRA. The Northern analyses showed that MtT/S cells express retinoic acid receptor alpha2 mRNA and thyroid hormone receptor beta2 mRNA, and DEX did not affect the levels of these mRNAs. This suggests that the role of DEX in enabling RAs or T3 to up-regulate GHRH-R mRNA levels is not an induction of the expression of each specific receptor for RAs and T3. The similar enhancement of DEX induction of GHRH-R mRNA by RAs or T3 was also observed in the fetal rat pituitary gland in culture, suggesting that RA and/or T3 is involved in the mechanisms responsible for the developmentally regulated expression of GHRH-R mRNA.

Gadolinium-enhanced MR angiography in the evaluation of congenital cardiovascular disease pre- and postoperative states in infants and children

The purpose of this study was to evaluate the utility of dynamic contrast magnetic resonance (MR) angiography under sedation for assessing congenital cardiovascular disease in infants and small children before and after cardiac surgery. In 38 patients with cardiovascular abnormalities, thoracic vasculatures were evaluated in either the preoperative (group 1; 23 patients, median age 9 months old) or the postoperative (group 2; 15 patients median age 1. 3 years old) state using gadolinium-enhanced dynamic MR angiography. Acquired data were processed with a multiprojection volume reconstruction. Image quality (grades 1-5, undiagnostic to excellent), presence or absence of the extracardiac vasculature, its pathology (group 1), and the patency of the postsurgical shunt or reconstructed vasculature (group 2) were evaluated. All images were of diagnostic image quality (mean grade 4.4-3.2). Recognition of the thoracic vasculature was correctly made in all cases (38/38, 100%). In group 1, anomalies and pathologic changes were correctly identified in 22 of 23 cases (95.7%). In one patient with dextrocardia and the cardiac type of total anomalous pulmonary venous return, the abnormality was not recognized. In group 2, the patency of the shunt flow after Glenn (n = 6), modified Fontan (n = 4), Rastelli (n = 1), and Blalock-Taussig (n = 3) operations was well demonstrated in each case. The reconstructed pulmonary artery (n = 1), veins (n = 2), and aorta (n = 1) were correctly visualized. In one case, stenosis of the reconstructed left pulmonary vein was missed by MR angiography. In 14 of 15 cases in group 2 (93.3%), MR angiography correctly gave information on the operated areas. In conclusion, dynamic contrast MR angiography under sedation is useful for evaluation of the thoracic vasculature of infants and small children in the pre- and postoperative states. J. Magn. Reson. Imaging 2000;12:1034-1042.

Effects of subtotal resection of the fundus on development of intestinal metaplasia induced by X-ray irradiation in Donryu rats

Eight-week-old male Crj:Donryu rats underwent subtotal resection of the fundus and X-ray irradiation. Six months later the animals were autopsied and examined for intestinal metaplasia. The numbers of alkaline phosphatase-positive foci with the two treatments in combination were significantly increased, compared to the operation alone and non-treatment groups. Histologically assessed intestinal metaplasia was also increased in the combined treatment group. In conclusion, subtotal resection of the fundus combined with X-ray irradiation is an effective induction protocol for intestinal metaplasia.

[A case of myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) related glomerulonephritis associated with systemic sclerosis treated by steroid pulse therapy: a case report]

A 57-year-old woman had been diagnosed as systemic sclerosis (SSc) with Raynaud's phenomenon, acrosclerosis and polyarthritis since 1995. She admitted to our hospital in July 1996 because of general fatigue, hemosputa and progressive renal insufficiency. On admission, the blood pressure was normal and laboratory findings showed elevation of the serum creatinin level and a high titer of the myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) (> 1000 EU). The renal biopsy revealed crescentic glomerulonephritis. Both renal insufficiency and high titers of MPO-ANCA improved remarkably after methylpredonisolone pulse therapy. This case was suggestive of elucidating the pathogenesis of SSc and MPO-ANCA related glomerulonephritis.

CikA, a bacteriophytochrome that resets the cyanobacterial circadian clock

The circadian oscillator of the cyanobacterium Synechococcus elongatus, like those in eukaryotes, is entrained by environmental cues. Inactivation of the gene cikA (circadian input kinase) shortens the circadian period of gene expression rhythms in S. elongatus by approximately 2 hours, changes the phasing of a subset of rhythms, and nearly abolishes resetting of phase by a pulse of darkness. The CikA protein sequence reveals that it is a divergent bacteriophytochrome with characteristic histidine protein kinase motifs and a cryptic response regulator motif. CikA is likely a key component of a pathway that provides environmental input to the circadian oscillator in S. elongatus.