Contrast-enhanced MRI of intrasellar arachnoid cysts: relationship between the pituitary gland and cyst

We recently encountered two large intrasellar arachnoid cysts extending to the suprasellar region. The intensity of the cyst contents was identical to that of the cerebrospinal fluid on both T1- and T2- weighted MRI. On contrast-enhanced MRI, the pituitary gland was compressed posteroinferiorly and flattened in the sella turcica. In this report of rare intrasellar arachnoid cysts the discussion is focused on dislocation of the pituitary gland.

Is pre-intervention intravascular ultrasound necessary in evaluating target lesion calcification in patients undergoing transcatheter therapy?

To identify a subset of patients with a high probability of extensive calcification for further intravascular ultrasound (IVUS) examination, the frequency and extent of target lesion calcification as assessed by IVUS and its correlations with age, gender and risk factors as well as the value of angiography in identifying ultrasound calcification were analyzed in 88 patients undergoing balloon angioplasty for significant coronary atherosclerotic stenosis. The extent of calcification was semi-quantitatively graded as 0: no calcification; +: calcification arc < 90 degrees; ++: calcification arc from 90 degrees to 180 degrees; : calcification arc > 180 degrees. The distribution pattern of calcification was classified as superficial, deep or mixed. The results indicate: (1) the frequency of target lesion calcification was 38.6%, of which 52.9% showed a superficial pattern and 56.0% had a calcification arc < 90 degrees; and (2) only age was significantly associated with target lesion calcification in all of the patients. The frequency of calcification was remarkably higher in patients > or = 60 years old than in patients < or = 60 years old (61.9% vs 17.4%, p < 0.001); (3) among patients less than 60 years old, those with calcification had a higher average number of risk factors than those without; and (4) the total sensitivity of angiography in identifying ultrasound calcification was 43.6%, with a significantly higher sensitivity for calcification arc > 180 degrees and mixed pattern. In conclusion, pre-intervention IVUS may be necessary in patients > or = 60 years old and in those < 60 years old with more than two risk factors in selecting devices to optimize interventional strategies.

Acetylcholine in the hippocampus during the discrimination learning performance in a rat model of chronic cerebral ischaemia

Acetylcholine (ACh) release in the hippocampus of Wistar strain rats with permanent bilateral occlusion of the common carotid arteries was examined during a discrimination learning task using a microdialysis method. Such occlusion resulted in obvious impairment of the discrimination performance. The state, the basal value and released patterns, of ACh in the hippocampus differed in the sham-operated control and the experimental group, while ACh release was elevated during the dialysis experiment in both groups. These findings suggested that the bilateral occlusion produced persistent learning deficits from an early stage after the operation and that the impaired discrimination learning performance might be related to the diffusion of ACh in the hippocampus.

Identical origin of adrenal cortex and gonad revealed by expression profiles of Ad4BP/SF-1

BACKGROUND

Ad4BP/SF-1 was originally identified as a steroidogenic tissue-specific transcription factor. Recent gene disruption studies with the mammalian Ftz-F1 gene encoding Ad4BP/SF-1 clearly revealed the essential function of the factor for adrenal and gonadal differentiation.

RESULTS

In this study, we examined the early development of these tissues using Ad4BP/SF-1 as the marker. In rat foetuses of 11.5 days post-coitum (d.p.c.), a cell population designated adrenogenital primordium was firstly observed on symmetrical lines extending from the dorsal aorta to the dorsal coelomic epithelia of the primitive urogenital ridges. From 12.5 d.p.c., the rostral half of the adreno-genital primordium started to separate into two distinct cell populations. Judging from the distribution of primordial germ cells, the cell population on the dorsal aortal side is a primordium for the adrenal cortex whereas that on the coelomic epithelial side is for the gonads. At 13.5 d.p.c., these two primordia have separated completely.

CONCLUSION

These observations clearly identified a novel adreno-genital primordium from which both the adrenal cortex and the gonads originate. An RT-PCR study conducted to detect adrenal- and gonad-specific mRNAs supported the above observations.

[Diagnosis of superficial-type early carcinoma of the gallbladder by endoscopic ultrasonography--comparison with ultrasonography]

The detectability of superficial-type carcinoma of the gallbladder by ultrasonography (US) and endoscopic ultrasonography (EUS) were investigated. Eight patients with such carcinoma of the gallbladder were reviewed. They had undergone both US and EUS previous to surgery. The tumor was detected in 3 patients by US, 2 patients with IIa + IIb-type carcinoma and 1 patient with IIa-type carcinoma. Those lesions were visualized as localized thickening of the gallbladder wall or as broad-based tumor. In 2 patients, lesions were not initially detected by US, but were shown by US after the examination by EUS. The tumor was detected by EUS also in 1 case of IIb + IIa-type carcinoma besides those 3 patients mentioned above. All four of these lesions were visualized as broad-based tumor by EUS. It was difficult to detect pure IIb-type or small IIa-type carcinoma even by EUS. In patients with concomitant acute cholecystitis or gallbladder stone, it was difficult to evaluate the abnormal findings of the gallbladder wall.

[Clinical evaluation of 99mTc-HMPAO labeled leukocyte imaging in ulcerative colitis]

Inflammatory imaging using 99mTc-HMPAO-labeled mixed leukocytes was assessed for use in treating 11 cases diagnosed as ulcerative colitis: 10 cases with total colitis and 1 with left-sided colitis. They consisted of 8 patients with relapse-remitting type and 3 with chronic continuous type. Radionuclide abdominal images were obtained at 1 hr, 4 hr and 24 hr after intravenous injection of 200 MBq prepared 99mTc leukocytes. Obvious colonic activity noted at 4 hr served as the basis for positive comparative criterion in the present study. The diagnostic efficacy of radionuclide imaging was compared with endoscopic findings (based on Matts' classification) and the clinical manifestations as reference. The sensitivity and specificity of this imaging were 83.3% and 85.7%, respectively, these values being consistent with endoscopic findings and clinical manifestations at sites of disease activity. All of positive images changed to negative after treatment by leukocyte apheresis or glucocorticoid. Based on these results, 99mTc leukocyte imaging can be used to accurately evaluate severity and treatment response in ulcerative colitis. Leukocytes may be closely related to the pathogenesis of ulcerative colitis.

Efficacy of high-frequency ultrasound probes for the preoperative staging of invasion depth in flat and depressed colorectal tumors

BACKGROUND

Flat and depressed nonpolypoid types of colorectal tumors have drawn much attention. Since endoscopic mucosal resection technique is available, it is of great importance to distinguish intramucosal carcinoma from invasive carcinoma because determination of the invasion depth is essential for choosing this therapy. The usefulness of high-frequency (20 MHz) ultrasound probes for preoperative staging of invasion depth in this type of colorectal tumor was evaluated.

METHODS

Forty-nine cases of flat and depressed tumors were examined with the ultrasound probe and diagnostic accuracy was confirmed by comparing ultrasonic images with the pathologic findings of the specimens resected either by endoscopic mucosal resection or surgical operation.

RESULTS

The normal colonic wall was visualized as a nine-layered structure and the muscularis mucosae was depicted in 37 (76%) of 49 cases. Flat and depressed tumors were visualized as hypoechoic lesions and the invasion depth was accurately diagnosed in 43 (88%) of 49 lesions.

CONCLUSIONS

High-frequency ultrasound probes proved to be useful in determining the invasion depth and therapeutic strategy in flat and depressed colorectal tumors.

One-month oral toxicity study of the new quinolone antibacterial agent (S)-10-[(S)-(8-amino-6-azaspiro[3,4]octan-6-yl)-9-fluoro-2,3-dihydro-3- methyl-7-oxo-7H-pyrido [1,2,3-de] [1,4] benzoxazine-6-carboxylic acid hemihydrate in rats and cynomolgus monkeys

One-month oral toxicity of (S)-10-[(S)-(8-amino-6-azaspiro[3,4] octan-6-yl)]-9-fluoro-2,3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3-de] [1,4]benzoxazine-6-carboxylic acid hemihydrate (CAS 151390-79-3, DV-7751a) a new quinolone antibacterial agent was investigated in Sprague-Dawley rats at doses of 12.5, 50, 200 and 800 mg/kg/d and in cynomolgus monkeys at 10, 30 and 100 mg/kg/d. Rats receiving 200 mg/ kg showed abnormal urine crystals, enhanced deposition of lipid in hepatocytes and exacerbation of osteochondrotic lesions in the femoral condyle. In addition, dosing at 800 mg/kg induced decrease in body weight gain and increased levels of serum alkaline phosphatase (ALP), cholinesterase, leucine aminopeptidase and total cholesterol. Monkeys receiving 100 mg/kg showed abnormal urine crystals and increases in serum glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and ALP levels. The non-toxic doses of DV-7751a in rats and monkeys were 50 and 30 mg/kg, respectively, under the present experimental conditions.

In vivo induction of cytotoxic T lymphocytes specific for a single epitope introduced into an unrelated molecule

Cytotoxic T lymphocytes (CTLs) recognise antigenic peptides in the context of major histocompatibility complex (MHC) class I molecules on virus-infected cells. The formation and transportation of antigenic peptides to class I MHC in the cells are multi-step reactions known as antigen processing. In order to design a good DNA vaccine, it is important to dissect the specificity of antigen processing. Here we describe the construction of an epitope-based plasmid vector as a device to investigate antigen processing in transfected cells. The epitope-based plasmid vector was constructed by insertion of an epitope-encoding minigene into the lacZ gene. We used a CTL epitope on influenza A virus nucleoprotein (NP366-374 epitope) as a model. Upon transfection, the epitope-based plasmid vector induced the expression of NP epitope antigenically as well as immunogenically. Immunization of mice with plasmid-transfected cells was able to induce NP epitope-specific CTLs in vivo. Moreover, the plasmid vector functioned as a gene vaccine; NP epitope-specific CTLs were primed in vivo upon transfection of the vector into dermis by electroporation. The results suggest that this epitope-based DNA delivery system may provide a new strategy for in vivo induction of epitope-specific CTLs to investigate antigen processing and presentation.

LD50 value, phototoxicity and convulsion induction test of the new quinolone antibacterial agent (S)-10-[(S)-(8-amino-6-azaspiro[3,4]octan-6-yl)]-9-fluoro-2, 3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxyl ic acid hemihydrate in laboratory animals

(S)-10-[(S)-(8-Amino-6-azaspiro[3,4]octan-6-yl)]-9-fluoro-2, 3-dihydro-3-methyl-7-oxo-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxyli c acid hemihydrate (CAS 151390-79-3, DV-7751a) a new quinolone antibacterial agent, was examined for LD50 value, phototoxicity and convulsion inducing potential in laboratory animals. A single oral administration of DV-7751a induced soft stool in rats at 1000 and 2000 mg/ kg and in monkeys at 250 mg/kg and vomiting in monkeys at 500 mg/kg or more. A single intravenous administration caused a decrease in locomotor activity, respiratory depression, convulsion, pulmonary edema and death in rats and mice. The LD50 values with oral administration were more than 2000 mg/ kg for rats and mice and more than 250 mg/kg for monkeys, and those with intravenous administration were 164.3 mg/kg for rats of both sexes at an injection rate of 2 ml/min, 118.8 mg/kg for male rats and 104 to 125 mg/kg for female rats at 0.5 ml/min, and 184.7 mg/kg for male mice and 187.4 mg/kg for female mice. DV-7751a showed very weak phototoxicity in mice after single oral administration of 600 mg/kg, followed by UVA irradiation, but no convulsion after oral administration of 200 or 1000 mg/kg in combination with 4-biphenylacetic acid at 400 mg/kg.

A new supportive method of aortic aneurysm surgery: centrifugal left heart bypass combined with an oxygenator and a heat exchanger

A new supportive method of centrifugal left heart bypass with oxygenation was performed in 25 patients and compared with standard left heart bypass in 45 patients. Femoro-femoral bypass was selected in another 6 patients because of the presence of a left atrial adhesion. Intraoperative complications related to standard left heart bypass, hypoxia, hypothermia, and ventricular fibrillation, were eliminated by using this method. This supportive method maintained good hemodynamics and improved the surgical result of extended thoracoabdominal aortic replacement. Hospital deaths decreased from 6.7% to 3.2%.

Inhibition of P-glycoprotein-dependent multidrug resistance by an isoquinolinesulfonamide compound H-87 in rat ascites hepatoma AH66 cells

The effects of an isoquinolinesulfonamide compound, H-87, on naturally acquired multidrug-resistance (MDR) in rat hepatoma AH66 cells were examined. AH66 cells were highly resistant to vinblastine, SN-38, an active camptothecin analog, adriamycin, and etoposide, compared with the sensitive variant AH66F cells. Although H-87 hardly affected the sensitivities to antitumor agents of AH66F cells, this compound completely inhibited the resistance to vinblastine, moderately inhibited the resistance to SN-38 and adriamycin and had little effect on etoposide, mitomycin C, cisplatin, and 5-fluorouracil. H-87 significantly decreased the efflux of vinblastine from the resistant cells and increased the drug accumulation. SN-38 and adriamycin also exhibited a weak but significant increase in vinblastine accumulation in AH66 cells. H-87 inhibited [3H]azidopine-photolabeling to 160 kDa P-glycoprotein in the plasma membrane of AH66 cells, as reported in acquired MDR leukemic cells. Consequently, the MDR-overcoming effect of H-87 seems to be due to its direct inhibition of the binding of antitumor agents on P-glycoprotein in the plasma membrane.

Selective activation of the proto-oncogene c-jun promoter by the transforming protein v-Rel

The transcription factor v-Rel is a transforming protein of the reticuloendotheliosis virus. We found that v-Rel activates the promoter of the proto-oncogene c-jun. Two elements in the c-jun promoter were required for the activation by v-Rel. One was a kB-site (v-Rel binding site), and the other was a c-jun promoter region between -52 and +148 (c-jun promoter (-52/+148)). Two promoters with the kB-site(s), those of human immunodeficiency virus (HIV) and SV40, were not activated by v-Rel, but their kB-sites were activated when introduced upstream of the c-jun promoter (-52/+148). Thus, the c-jun promoter (-52/+148) had information for the selective activation of the c-jun promoter by v-Rel. v-Rel bound to the c-jun kB-site with the higher affinity than c-Rel, thereby activating the c-jun promoter more efficiently than c-Rel. Moreover, the activity of v-Rel mutants upon the c-jun promoter correlates with their transforming activity. Thus, the c-jun promoter activation by v-Rel may play a role in the transformation caused by v-Rel.

Characterization of naturally acquired multiple-drug resistance of Yoshida rat ascites hepatoma AH66 cell line

Characteristics of multiple-drug resistance of rat ascites hepatoma AH66, a cell line induced by dimethylaminoazobenzene and established as a transplantable tumor, were compared with those of AH66F, a drug sensitive line obtained from AH66. The AH66 cell line was resistant to vinblastine, adriamycin, SN-38 an active form of camptothesine, etoposide, and clorambucil by 10-fold or more than the AH66F cell line. The resistance of AH66 cells to vinblastine, adriamycin, and SN-38 was closely related to P-glycoprotein overexpression in the plasma membrane, because the resistance was significantly inhibited by verapamil. AH66 cells contained much glutahione and had a high activity of glutathione S-transferase P-form (GST-P), compared with AH66F cells, and resistance to clorambucil was decreased by treatment with buthionine sulfoximine, an inhibitor of glutathione synthesis. AH66 cells have a similar topoisomerase I activity, but about 6 times lower topoisomerase II activity than AH66F cells. Therefore, the resistance to etoposide and a part of the resistance to adriamycin of AH66 cells seems to depend upon this low topoisomerase II activity. These results, show that the AH66 cell line has high multiple-drug resistance compared with the AH66F cell line, by several mechanisms. Consequently, the AH66 and AH66F cell lines are useful to study naturally acquired multiple-drug resistance of hepatomas.

Effect of antioxidants, anti-inflammatory drugs, and histamine antagonists on sparfloxacin-induced phototoxicity in mice

We examined the effects of antioxidants, anti-inflammatory drugs, and histamine antagonists on auricular inflammation and retinal degeneration induced by the phototoxicity of sparfloxacin (SPFX), a quinolone antibacterial agent. Catalase (CAT), dimethyl sulfoxide (DMS0), dexamethasone (DM), indomethacin (IM), phenidone (PD), AA-861 (AA), pyrilamine maleate (PY), or cimetidine (CM) was continuously administered to female Balb/c mice using microosmotic pumps for 72 hr and intraperitoneally once before SPFX administration. The mice were given a single oral administration of 50 or 100 mg/kg SPFX and irradiated with ultraviolet-A (UVA) light at 1.5 mW/cm(2) for 4 hr. SPFX administration plus UVA irradiation induced thickening and inflammation of the auricular skin and retinal degeneration in the eye. CAT and DMS0 significantly inhibited the auricular thickening only 4 hr after SPFX administration. DM, IM, and PD also inhibited this toxicity from 4 to 48 or 72 hr. On the other hand, PY and CM showed no effect on this change. With regard to the eye, CAT and DMSO completely inhibited the occurrence of retinal degeneration and IM and PD tended to decrease its incidence, whereas DM, AA, PY, and CM showed no or an exacerbating effect. These results suggest that reactive oxygen species contribute to the initiation of auricular inflammation and retinal degeneration and that cyclooxygenase products are also involved in the initiation and later progression of auricular inflammation. They also show that histamine and 5-lipoxygenase products are not involved in either phototoxic lesion.

[Evaluation of the clinical usefulness of super dynamic 99mTc-HM-PAO SPECT in ischemic cerebrovascular disease--detection of hypo- and hyperperfusion area]

The purpose of this study is to assess the clinical usefulness of super dynamic SPECT of 99mTc-HM-PAO. Six patients with unilateral occlusion of middle cerebral artery (MCA) or internal carotid artery (ICA) in the chronic phase, and 5 patients with subacute cerebral infarction were studied. We used a ring-type SPECT "HEADTOME." Two types of collimator were used: a high sensitivity (HS) collimator for super dynamic scan and a high resolution (HR) collimator for static scan. First, the intravenous constant infusion of 99mTc-HM-PAO (925-1480 MBq) for 1 minute was started. After 30 seconds from the beginning of the injection, we performed the 12 seconds/frame super dynamic SPECT for 2 minutes. Then, the static SPECT for 10 minutes was done. For semiquantitative analyses, differential percentage of regional activity between affected and non-affected hemispheres was calculated in the 6th frame image of super dynamic SPECT and static SPECT image. In all 6 patients with unilateral occlusion of MCA and ICA, super dynamic SPECT images showed the better contrast of low perfusion areas in comparison with the static SPECT images. In 5 patients with subacute cerebral infarction who showed focal hyperactivities on static SPECT, focal hyperactivities (hyperperfusion or hyperemia) were displayed in 3 cases, whereas, focal hypo- or isoactivities (hypo- or isoperfusion) were shown in 2 cases on super dynamic SPECT. However, all patients with subacute cerebral infarction showed hyperfixation on static SPECT as compared with super dynamic SPECT. Although the image quality on super dynamic SPECT is not as high as that on static SPECT, cerebral hemodynamics would be detected with less backdiffusion of 99mTc-HM-PAO from the brain to blood, and with less accumulation of hydrophilic components in subacute infarct region. In conclusion, super dynamic SPECT in early distribution of 99mTc-HM-PAO using dedicated SPECT device might be helpful to detect cerebral perfusion close to true cerebral blood flow distribution.

Monoclonal antibodies specific to the integral membrane protein P0 of bovine peripheral nerve myelin

Two monoclonal antibodies (mAbs), 58A and 46E, were generated against the major protein P0 of bovine peripheral nervous system myelin (PNSM). The reactivities of the mAbs were assessed by enzyme-linked immunosorbent assay (ELISA), Western blot, and immunohistochemistry. Both mAbs, 58A and 46E, reacted to PNSM of bovine, human, rat and rabbit, but not to chicken PNSM or the brains of rat and rabbit. In the Western blot, these mAbs showed specific binding to bovine P0 as well as deglycosylated P0, but not to myelin-associated glycoprotein (MAG) of bovine spinal cord. The analyses of the lysylendopeptidase-digested peptides of bovine P0 revealed that the epitopes for the mAbs 58A and 46E were located on the amino acid residues 68-79 and 210-216, respectively. Since the mAbs 58A and 46E recognize the extracellular domain and the cytoplasmic domain of P0, respectively, they could be useful for studies on P0's role in myelin formation, its adhesive properties, and functions of the N-terminal extracellular and C-terminal cytoplasmic domains of the protein.

Saturable function of P-glycoprotein as a drug-efflux pump in multidrug-resistant tumour cells

P-glycoprotein acts as an active drug-efflux pump in multidrug-resistant tumour cells. We studied the capacity of P-glycoprotein to extrude drugs from the cells. For nanomolar concentrations of vinblastine P388/ADR cells, which overexpress P-glycoprotein in the plasma membrane, accumulated vinblastine, at 37 degrees C for 30 min, to a much lower extent than the sensitive cells (P388/S), while in the micromolar range the cellular concentration was similar for both types of cells. When cells were incubated with a low (10 nM) or high concentration (1 microM) of vinblastine while energy deprived, the vinblastine concentration increased only in the resistant cells incubated with the low concentration of vinblastine, and this increased level was lowered to the level under the normal conditions by addition of glucose. In contrast, the cellular concentrations in other cases were increased to the normal level by glucose. After cells were loaded with the low concentration of vinblastine, the cellular vinblastine was extruded more rapidly from the resistant cells than from the sensitive cells. The courses of vinblastine efflux from the cells loaded with the high concentration of vinblastine were similar in both types of cells. NA-382, a reported P-glycoprotein inhibitor, effectively increased the intracellular vinblastine and inhibited the drug efflux only from multidrug-resistant cells, P388/ADR and AH66 cells, which were incubated with the low concentration of vinblastine. Cellular uptake of NA-382 was also less in P388/ADR cells than in P388/S cells in culture with 10 nM but not 1 microM of the agent, and this low level was reversed to the level in the sensitive cells by 10 microM vinblastine. These results indicate that P-glycoprotein as a drug-efflux pump works effectively under low extracellular concentrations of substrates, but does not under the high concentrations.

Autoregulatory loop in the regulation of the mammalian ftz-f1 gene

The mammalian ftz-f1 (mftz-f1) gene encoding Ad4BP/SF-1 has been demonstrated to be essential for the development of adrenal and gonadal glands. In a previous study, we identified an E box as the transcriptional element in the 5'-upstream region of the rat mftz-f1 gene. In the present study, we found a steroidogenic cell-specific transcriptional element in the first intron of the gene. Gel mobility shift and DNase I footprint analyses clearly revealed that Ad4BP itself binds to the element (Ad4 site). This finding was further supported by the positive effect of an Ad4BP expression vector on the transcription and by the significant decrease in the transcription caused by nucleotide substitutions within the Ad4 site. Similar loss was also caused by substitutions in the E box, indicating that the two elements are essential for the full transcriptional activity of the gene. DNase I hypersensitivity assays revealed that the chromatin structure around the Ad4 site and the E box was "open up" in the adrenal glands and Y-1 cells, whereas "closed down" in the liver. These observations indicated that the mftz-f1 gene is controlled by the autoregulatory loop in the steroidogenic tissues. The autoregulatory mechanism seems to be necessary to keep the mftz-f1 gene activated and thus maintain the tissues differentiated.

Multiprotein transcription factor UAF interacts with the upstream element of the yeast RNA polymerase I promoter and forms a stable preinitiation complex

Like most eukaryotic rDNA promoters, the promoter for rDNA in Saccharomyces cerevisiae consists of two elements: a core element, which is essential, and an upstream element, which is not essential but is required for a high level of transcription. We have demonstrated that stimulation of transcription by the upstream element is mediated by a multiprotein transcription factor, UAF (upstream activation factor) which contains three proteins encoded by RRN5, RRN9, and RRN10 genes, respectively, and probably two additional uncharacterized proteins. The three genes were originally defined by mutants that show specific reduction in the transcription of rDNA. These genes were cloned and characterized. Epitope tagging of RRN5 (or RRN9), combined with immunoaffinity purification was used to purify UAF, which complemented all three (rrn5, rrn9, and rrn10) mutant extracts. Using rrn10 mutant extracts, a large stimulation by UAF was demonstrated for template containing both the core element and the upstream element but not for a template lacking the upstream element. In the absence of UAF, the mutant extracts showed the same weak transcriptional activity regardless of the presence or absence of the upstream element. We have also demonstrated that UAF alone makes a stable complex with the rDNA template, committing that template to transcription. Conversely, no such template commitment was observed with rrn10 extracts without UAF. By using a series of deletion templates, we have found that the region necessary for the stable binding of UAF corresponds roughly to the upstream element defined previously based on its ability to stimulate rDNA transcription. Differences between the yeast UAF and the previously studied metazoan UBF are discussed.

A catalogue of genes in mouse embryonal carcinoma F9 cells identified with expressed sequence tags

We used expressed sequence tags (ESTs) to identify genes expressed in mouse embryonal carcinoma F9 cells and prepared 2132 ESTs from undifferentiated F9 cDNA libraries: 1026 were prepared after randomly selecting clones from one of the libraries and the remaining 1106 ESTs were prepared after classifying 2896 clones of the libraries into four classes, according to the levels and patterns of expression. Among the former 1026 ESTs, 797 (78%) matched known genes, 61 (6%) matched database sequences of uncharacterized cDNAs, and 168 (16%) represented novel genes. The ESTs matching known genes were catalogued according to putative structural and cellular functions. As many as 53% were related to transcription and translation, and 19% were related to energy metabolism, including transcripts of mitochondrial DNA. These percentages were significantly higher in F9 cells than in the human heart and brain, and a human liver cell line, HepG2. We found that approximately 7% of the ESTs corresponding to low-abundance mRNAs are either related to retinoic acid-regulated genes or mammalian development- and/or differentiation-related genes. Cataloguing of the genes expressed in the F9 cells paves the way for isolating genes involved in early mammalian development.

A high linoleate and a high alpha-linolenate diet induced changes in learning behavior of rats. Effects of a shift in diets and reversal of training stimuli

Rats fed from weaning on semi-purified diets supplemented either with linoleate-rich safflower oil (S) or alpha-linolenate-rich perilla oil (P) were mated. Half of the progeny were weaned to the original diet of the dams (SS and PP), the other two groups were shifted to diets enriched in the other fatty acid (SP and PS). Brightness-discrimination learning ability was tested daily for 30 d beginning at 11 weeks of age, with a bright light as the positive stimulus. The learning performance was inferior in the group fed the safflower diet through two generations (SS) as compared with groups fed the perilla diet through two generations (PP) or for which the diets were shifted at weaning (PS and SP). The docosahexaenoate content of brain phospholipids was significantly less in the SS group compared with the three other groups. After 30 d of the learning test, the effect of shifting the stimulus was tested for another 30 d, this time using a dim light as the positive stimulus. The learning performance was superior in the PP group to the SS group throughout the latter 30 sessions, the difference being even more obvious than during the first 30 d. These results indicate that the decrease in the discrimination-learning ability induced by alpha-linolenate deficiency is a relatively reversible process; both the docosahexaenoate content in brain and the learning performance were restored by supplementing alpha-linolenate after the weaning.

Deoxycholic acid as an endogenous risk factor for hepatocarcinogenesis and effects of gomisin A, a lignan component of Schizandra fruits

Although hepatocarcinogensis has been reported to be promoted by exogenous administration of bile acids, the relation of endogenous bile acids to hepatocarcinogenesis is not completely understood. This study investigates the relationship between serum concentration of bile acids, the appearance of preneoplastic change, glutathione S-transferase placental form (GST-P)-positive foci in the liver of male Donryu rats which had been fed 0.06% 3'-methyl-4-dimethylamino-azobenzene (3'-MeDAB), and the effects of gomisin A, previously reported to inhibit the tumor promotion process. During the feeding of 3'-MeDAB for 5 weeks, the concentrations of serum bile acids were found to have increased significantly to several times the levels found at the start of the experiment. The increase of serum bile acids, especially deoxycholic acid (DCA), and the appearance of preneoplastic lesions, the number and area of GST-P-positive foci in the liver, were significantly inhibited by simultaneous oral administration of gomisin A (30 mg/kg). When DCA (100 mg/kg) was orally administered after an initiation by 3'-MeDAB, serum bile acids and preneoplastic changes were significantly increased, these increases were inhibited by combined feeding of 0.03% gomisin A in the diet. There were good correlations between the serum concentration of DCA and the number of GST-P-positive foci in the liver in both experimental protocols. These results confirm that DCA is an endogenous risk factor for hepatocarcinogenesis and suggest that anti-promoter effect of gomisin A is based on improving metabolism of bile acids, including DCA.