A survey of genes expressed in undifferentiated mouse embryonal carcinoma F9 cells: characterization of low-abundance mRNAs

As a first step to catalogue mRNAs present in mouse embryonal carcinoma F9 cells, 879 clones corresponding to low-abundance mRNAs were selected from among 2,896 randomly picked up clones of undifferentiated F9 cDNA libraries, using DNA probes complementary to poly(A)+RNAs prepared from undifferentiated F9 cells and to ones prepared from mouse fibroblast L cells. Five-hundred and eighty-two of the 879 clones were partially sequenced, and the subsequent homology search revealed that 201 corresponded to 180 known genes or known DNA sequences, which include not only housekeeping genes but also various tissue-specific genes. Interestingly, at least 24 of the 180 genes are development-related genes in mammals. Among these 24, those for midkine (growth and/or differentiation factor) and interferon-beta are reportedly up-regulated, and those for ECA39 (target for c-Myc regulation), REX-1 (zinc finger protein), and OCT-3 (POU-domain transcription factor) are down-regulated during the development of mouse embryonal carcinoma cells. Thirty-seven of the 582 clones matched the 36 previously reported unidentified ESTs (expressed sequence tags) and the remaining 344 corresponded to 329 novel ESTs. Therefore, partial sequencing of F9 cDNA clones corresponding to low-abundance mRNAs in F9 cells not only provides valuable information concerning development-related genes in mammals, but also many novel ESTs useful for studying mammalian genomes.

Angiotensin II receptor antagonist TCV-116 induces regression of hypertensive left ventricular hypertrophy in vivo and inhibits the intracellular signaling pathway of stretch-mediated cardiomyocyte hypertrophy in vitro

BACKGROUND

Previous studies have demonstrated that angiotensin II (Ang II) acts as a growth-promoting factor directly on cardiac myocytes and that angiotensin-converting enzyme inhibitor induces regression of hypertrophied hearts both in experimental animals and in humans. These results suggest that the renin-angiotensin system (RAS) is involved in the formation of left ventricular hypertrophy (LVH). To elucidate the role of RAS in the progression of cardiac hypertrophy, we evaluated the effect of an Ang II receptor antagonist on LVH in spontaneously hypertensive rats (SHRs) and investigated the molecular mechanisms by which antagonizing Ang II receptors reduces cell hypertrophy of myocytes using the in vitro model of mechanical stretch.

METHODS AND RESULTS

In the in vivo study, we treated SHRs with the nonpeptide Ang II receptor antagonist TCV-116 (0.1, 1, or 10 mg/kg per day) or hydralazine (10 mg/kg per day). Blood pressure was measured by the tail-cuff method, and wall thickness of left ventricle was serially monitored using M-mode echocardiography. Rats were killed at the age of 13, 17, 21, or 25 weeks, and left ventricular (LV) weight, transverse diameter of cardiomyocytes, relative amount of V3 myosin heavy chain (MHC), and degree of interstitial collagen accumulation were examined. Untreated SHRs progressively developed severe hypertension, but treatment with TCV-116 or hydralazine inhibited the increase in blood pressure. Treatment with TCV-116 reduced LV weight, LV wall thickness, transverse diameter of myocytes, relative amount of V3 MHC, and interstitial fibrosis, whereas treatment with hydralazine slightly prevented an increase in LV wall thickness but did not exert significant reduction in other parameters. In the in vitro study, neonatal rat cardiomyocytes were cultured on deformable silicone dishes and mechanically stretched with or without pretreatment of CV-11974 (an active metabolite of TCV-116), and [3H]phenylalanine incorporation, activity of mitogen-activated protein (MAP) kinase, and c-fos mRNA expression were analyzed. Pretreatment of cultured cardiomyocytes with 10(-7) mol/L CV-11974 inhibited an increase in [3H]phenylalanine incorporation, MAP kinase activity, and c-fos gene expression induced by stretch of cardiomyocytes.

CONCLUSIONS

The Ang II receptor antagonist TCV-116 induced regression of cardiac hypertrophy and had cardioprotective effects on hypertrophied myocardium in vivo, and antagonizing Ang II receptors inhibited intracellular signaling of stretch-mediated cardiomyocyte hypertrophy in vitro. These results suggest a crucial role of the cardiac RAS in the development of LVH produced by pressure overload.

Maspin, a serpin with tumor-suppressing activity in human mammary epithelial cells

A gene encoding a protein related to the serpin family of protease inhibitors was identified as a candidate tumor suppressor gene that may play a role in human breast cancer. The gene product, called maspin, is expressed in normal mammary epithelial cells but not in most mammary carcinoma cell lines. Transfection of MDA-MB-435 mammary carcinoma cells with the maspin gene did not alter the cells' growth properties in vitro, but reduced the cells' ability to induce tumors and metastasize in nude mice and to invade through a basement membrane matrix in vitro. Analysis of human breast cancer specimens revealed that loss of maspin expression occurred most frequently in advanced cancers. These results support the hypothesis that maspin functions as a tumor suppressor.

[The applicability of a new stable fluorescence reagent CGE (N) for TLC measurements and spectrofluorimetry]

A new stable fluorescent reagent, CGE (N), was designed and synthesized in our laboratory. This paper presents the results of using it to detect a compound having aminogroup. Glycine as an example was derived by using CGE (N), the best condition of derivatisation reaction was pH8, T 50 +/- 1 degree C, and time 3-5 h. Spread agent was CHCl3: CH3OH:CH3COOC2H5: iceHAc (1:3:5:1). Rf of glycine-CGE (N) was 0.45, of which fluorescent spectrum Em was 356nm (at Ex = 277nm). The correlation coefficient between the fluorescent scanning area and quantity was over 0.99, the linear relation retained for 24 h, the detection limit 0.24 microgram, and the linear range 0.24-19.2 micrograms. The data revealed that stability, sensitivity and reproducibility were good. These indicate that CGE(N) is a fine fluorescent reagent for compounds having primary amino-group and this method is reliable.

Sequential quantitative scintigraphy of parotid glands with chronic inflammatory diseases

A practical, time-saving procedure for sequential quantitative scintigraphy is introduced and 4 parameters chosen from 12 parameters by discriminant analysis are used to evaluate the function of the parotid gland. The examination was performed in 120 cases, including 16 cases with recurrent parotitis in childhood, 33 with chronic obstructive parotitis (COP), 37 with Sjögren's syndrome (SS), 4 with sialadenosis, and 30 normal controls. The scintigraphic findings were analyzed and compared with the histologic findings. The diagnostic value of this method was investigated and scaling for differential diagnosis of COP and SS was established. Scintigraphy is considered to be a useful method for evaluation of parotid function and as a diagnostic aid for SS and COP, especially in patients in whom sialography cannot be performed.

[The qualitative and quantitative analyses of protein with a novel fluorescence agent (EPQS) by fluorescent scanning on solid substrate]

We synthesized a new fluorescence agent, EPQS, which could be soluble in water and was stable in the analytical process. It was characteristic of good fluorescence parameters. Human serum albumin (HSA) was marked with EPQS and purified by the paper electrophoresis dialysis. We determined the fluorescent spectra and excitation spectra of the marked HSA, or EPQS on the cellulose acetate paper by RF-510 fluorescence spectrophotometer-thin-layer chromatoscanner. The former lambda ex = 370nm lambda em = 470nm; the latter lambda ex = 382nm lambda em = 476 nm. Then we touched different quantity of EPQS-HSA upon the cellulose acetate. The fluorescent scanning on the paper disclosed that the relationship between the quantity adopted and the fluorescence intensity is linear. These showed that the protein could be quickly determined qualitatively and quantitatively by this simple method, and EPQS was useful.

[Clinical study and long-term follow-up observations on the effect of PCV and SV+A in the treatment of duodenal ulcer]

From Aug. 1977 to June 1988, vagotomy had been performed in 238 patients with duodenal ulcer (DU). According to the clinical signs and the result of gastric acid secretion test, (GAST) parietal cell vagotomy (PCV) and selective vagotomy plus antrectomy (SV+A) were performed in 100 and 138 cases respectively. The patients were followed up for 1 to 10 years. 96% and 97% of them belonged to Visick grade I and II respectively. The recurrence rate was 1.96% in PCV group, while no ulcer recurrence was seen in SV+A group, long-term side effect was rare and the nutritional status was quite good. The follow-up data showed that recurrence rate could be greatly reduced if the mode of vagotomy was selected according to results of GAST.

[States of dentine surface and interface between dentine and coupling agent]

In order to research the states of dentine surface and dentine surface primed with coupling agent, we used microscope, transmission electron microscope (TEM) and solid fluorescence method. Observed under microscope, patterning of dentinal tubules and their poles was very explicit; through the view of interface between coupling agent adsorbed and human dentine powder by TEM, it was revealed that the coupling agent was adsorbed onto the dentine surface as if it "grew out" of the dentine surface; through examination of interface between the coupling agent adsorbed and dentine surface by fluorescence spectrum, which differed from that of the coupling agent or dentine surface, i.e., this fluorescence spectrum of interface changed obviously (red shift). This phenomenon indicated that there was a chemical reaction occurring between tooth surface and adsorbed coupling agent. Therefore we can conclude that the three examinations are necessary to provide the argument for establishment of chemical bonding mechanism between dentine and coupling agent.