A novel transcript from a pseudogene for human glucocerebrosidase in non-Gaucher disease cells

Human glucocerebrosidase (GC)-encoding cDNA clones were isolated from a promyelocytic HL-60 cDNA library and analyzed. A novel cDNA clone was found to originate from a gene referred to as a GC pseudogene. Using the polymerase chain reaction (PCR) with primers specific for the GC pseudogene, we found that all the human cell lines examined, HL-60, K-562, WI-38, HepG2 and HeLa, expressed a pseudogene transcript. In vitro translation of RNA synthesized by transcription of the pseudogene cDNA produced a polypeptide of approximately 30 kDa.

Brefeldin A inhibits muscle-specific gene expression during differentiation in C2C12 myoblasts

In analyzing regulatory mechanisms underlying differentiation-dependent expression of muscle proteins, we have found that mouse C2C12 myoblast cells treated with Brefeldin A (BFA), which specifically blocks the intracellular transport of protein from endoplasmic reticulum (ER) to the Golgi apparatus, failed to differentiate. BFA reversibly inhibited myotube formation at a threshold concentration of 1.0 micrograms/ml. The same concentration of BFA completely blocked accumulation of secretory proteins, e.g., fibronectin into the culture medium, probably due to retention in ER. Interestingly, the induction of muscle creatine phosphokinase (MCK) activity was sensitive to BFA, although a constitutive expression of lactate dehydrogenase, one of the cytosolic housekeeping enzymes, was resistant to BFA. In the kinetic analysis of MCK induction, translation of existing MCK mRNA was not inhibited by BFA since MCK activity became resistant to BFA once levels of MCK transcript accumulated. The differentiation-dependent accumulation of MCK transcript was also suppressed by BFA treatment to approximately 30% of control, although neither general transcriptional activity in vivo nor stability of existing mRNAs was affected even in the presence of BFA. Moreover, induction of muscle regulatory genes, MyoD1 and myogenin, which are upstream of the MCK gene, were inhibited at their transcription level by BFA. Such an effect on muscle regulatory gene transcription by BFA suggests that transport of some factor(s) to the cell surface may be a prerequisite for the muscle-specific gene expression upon differentiation of C2C12 myoblasts.

Age dependency of mitochondrial DNA decrease differs in different tissues of rat

Mitochondrial DNA contents were measured using non-radioactive DNA probes for specific mtDNA sequences. The nuclear repetitive DNA sequence, LINE, was used as an internal standard marker. Age-dependent decreases in the mtDNA/nucDNA ratio in rat hepatic cells were confirmed with this method and, furthermore, a similar decrease was found in cardiac muscles. On the other hand, in thigh skeletal muscles such a decrease was not observed, slight increases being rather found in 18- to 24-month-old rats. The possible relationship of the decrease in mtDNA and the mechanism underlying animal senescence was discussed.

Identification of two novel mouse nuclear proteins that bind selectively to a methylated c-Myc recognizing sequence

The c-Myc recognizes the sequence CACGTG (Blackwell, T. K., Kretzner, L., Blackwood, E.M., Eisenman, R. N., and Weintraub, H. (1990) Science 250, 1149-1151), and its binding is inhibited by methylation of the core CpG (Prendergast, G. C. and Ziff, E. B. (1991) Science 251, 186-189). We identified two novel nuclear proteins, MMBP-1 and MMBP-2, that bound specifically and under physiological salt condition to the c-Myc binding motif of which cytidine in the CpG sequence was methylated. MMBP-1 was about 42 kD and MMBP-2 was about 63 kD. MMBP-1 was found in specific cells, while MMBP-2 was found in all the cell lines tested, suggesting that MMBP-1 may modulate the role of MMBP-2 in tissue specific manner. We propose that the two proteins play a role in the regulation of c-Myc function through stabilizing or destabilizing the methylation state of the c-Myc binding motif.

Transitional expression of neural cell adhesion molecule isoforms during chicken embryonic myogenesis

The neural cell adhesion molecule, NCAM, is known to be expressed in chicken muscle as at least three principal molecular forms (molecular masses of 155 kDa, 145 kDa, and 120 kDa). They are generated from a single gene by alternative splicing. To distinguish these molecular species and to investigate their expressions in muscle differentiation during chicken embryonic development, we prepared antipeptide antibodies against three different domains of the NCAM. The antibody named MSD<+> was designed to detect muscle-specific domain (MSD) which was inserted into a muscle-specific NCAM by alternative splicing. The locus encompassing the MSD insertion site was detected with the antibody named MSD<->, and cytoplasmic sites near the transmembrane region were detected with the antibody named CYT. Immunoblot analysis utilizing the peptide antibodies prepared here revealed that, of three NCAMs, two isoforms, 155 kDa and 120 kDa, were recognized with the antibody MSD<+> and the same 155-kDa and the other 145-kDa molecule were recognized with the antibody CYT. The antibody MSD<-> was capable of detecting all three isoforms of the NCAM. Expression of the 120-kDa form with MSD but lacking a cytoplasmic tail increased but that of the 145-kDa form with cytoplasmic tail but lacking MSD declined during embryonic day 5 to day 18. The 155-kDa form NCAM with both MSD and cytoplasmic tail was expressed specifically and transiently during embryonic day 11 to day 14 in chick muscle; this period coincides with the period of extensive myotube formation. Thus, this largest isotype seems to play an important role in muscle differentiation.

Quantitation of changes in mitochondrial DNA during aging and regeneration of rat liver using non-radioactive DNA probes

By using DNA probes prepared from cloned cells which contain mitochondrial DNA (mtDNA) sequences in plasmids, the specific detection of mtDNA became possible in the presence of large excess of nuclear DNA by DNA-DNA hybridization. For this purpose, we prepared mtDNA probes labeled with non-radioactive substrate, which allowed a wider possibility of application. This method revealed that the contents of mtDNA in rat liver are strikingly decreased during aging. Furthermore, it was observed that although mtDNA content increased upon partial hepatectomy even in old rats, it decreased to the pre-operation level rather rapidly within 1 week after reaching peak in regenerated liver.

Optimization of the weighted median filter by learning

The weighted median filter (WMF) is a generalization of the median filter. The WMF is more effective for image processing than the conventional median filter. However, the design of the parameters of the WMF is a difficult problem. A novel method of optimizing the WMF is proposed that utilizes the close relation between the nonrecursive WMF and the feed-forward neural network with shift-invariant weight coefficients. The optimization problem of the WMF results in the learning of the interconnection weights of the network.

Direct evidence for the presence of methylmercury bound in the thyroid and other organs obtained from mice given methylmercury; differentiation of free and bound methylmercuries in biological materials determined by volatility of methylmercury

Peroxidase in mouse thyroid was inhibited by mercuric chloride but not by methylmercury in in vivo and in vitro systems (Nishida, et al., J. Histochem. Cytochem., 37, 723 (1989)). To identify the reason for the difference, the present study was conducted to examine whether methylmercury is indeed bound within cells or tissues. Mice were given radioactive methylmercury by intubation for 18 d and the tissues were dissected out and vacuum-dried. With this procedure, free methylmercury was evaporated off and the bound mercury remained. The thyroid, liver, kidney and fats examined showed no loss of radioactivity under the vacuum, indicating that the mercury was bound to the thyroid, as well as the other tissues. Radioactive mercuric chloride was nonvolatile regardless of the presence or absence of the tissues. The preferential affinity of methylmercury for SH-containing materials was re-confirmed by this method.

Binding of cholesterol and inhibitory peptide derivatives with the fusogenic hydrophobic sequence of F-glycoprotein of HVJ (Sendai virus): possible implication in the fusion reaction

Specificity of the binding of sterols and related compounds with purified F-protein (fusion protein) of the HVJ (Sendai virus) was studied by binding competition with [3H]cholesterol. Requirement for cholesterol or the A/B ring trans structure and nonrequirement for the 3-hydroxyl group were found in this binding. Binding of 125I-labeled Z-Phe-Tyr, an inhibitory peptide of viral membrane-cell membrane fusion, was studied by using purified proteins and virions. F-Protein and virions showed a specific binding with the peptide, whereas the result was negative with hemagglutinin and neuraminidase protein. Thermolysin-truncated F-protein (an F-protein derivative deprived of a 2.5-kDa fragment from the N-terminal of the F1 subunit and without fusogenic activity) exhibited a considerably diminished binding ability both to cholesterol and to inhibitory peptides. Therefore, the N-terminal hydrophobic sequence that was previously assigned as fusogenic seems to be the binding site of these molecules. In support of this, the binding of cholesterol with F-protein was inhibited by Z-Phe-Tyr and other fusion inhibitory peptides, whereas it was not affected with non-fusion-inhibitory Z-Gly-Phe. These results are discussed in relation to the notion that the binding of the N-terminal portion of the F1 subunit of F-protein with cholesterol in the target cell membranes facilitates the fusion reaction.

Characteristic structures of actin gels induced with hepatic actinogelin or with chicken gizzard alpha-actinin: implication for their function

We studied the properties of actinogelin, a Ca2+-regulated actin cross-linking protein isolated from Ehrlich tumor cells or rat liver. Chicken gizzard alpha-actinin was used as a Ca2+-insensitive control. Actinogelin, which has very high gelation activity under low Ca2+ conditions, was found using electron microscopic or fluorescence studies to induce formation of a characteristic structure in which actin filaments and bundles radiate to (or converge from) all directions from spot-like core structures. A similar structure was induced with actinogelin, even in the presence of 0.7 saturation of tropomyosin. No such structure was detected with actinogelin under high Ca2+ conditions, and only a few were found with gizzard alpha-actinin. Because reconstituted structures are similar to those observed intracellularly, actinogelin may be important in the formation of similar microfilament organization in the cells. It seems also important that these structures are reconstituted with only two purified protein components, i.e., actinogelin and actin. Immunocompetition studies showed that actinogelin and gizzard alpha-actinin partially shared antigenicity, and their molecular shape and peptide maps were similar. Their amino acid compositions [Kuo et al., 1982], subunit and domain structures, and binding sites on actin [Mimura and Asano, 1987] are also very similar. Therefore, it is concluded that actinogelin belongs to alpha-actinin superfamily proteins. Furthermore, the presence of functionally different subfamilies concerned with Ca2+ sensitivity, gelation-efficiency, and others is discussed. Actinogelin, which induces networks of actin filaments, may be classified as high gelation type.

[Preoperative assessment of risk for gastroenterological operations in patients with hepatic cirrhosis]

In order to devise an easy and available method to assess the surgical risk of cirrhotic patients, we reviewed 52 cirrhotic patients who underwent gastroenterological operations at Tokyo Kosei Nenkin Hospital between 1968 and 1982, by means of multivariant discriminant analysis. Utilizing presence of ascites, serum albumin, ICG R15, prothrombin time and platelet count, we estimated the surgical risk as Risk Score. Furthermore, our method predicted short-term survival of other 150 cirrhotic patients who underwent gastroenterological operations at the First Surgical Department The University of Tokyo between 1968 and 1985. We conclude that our method is easily available, and that cirrhotic patients with Risk Score less than or equal to 2.5 tolerate all the gastroenterological operations except hepatic major resection, and that those with Risk Score of residual liver less than or equal to 2.5 tolerate well hepatic major resection.

Smoking, alcohol drinking and serum carotenoids levels

Serum carotenoids concentrations in healthy inhabitants, aged 40-79 years, of a community were measured. The results are as follows. 1. The alpha- and beta-carotene and lycopene levels in serum were significantly higher in females than males. The alpha- and beta-carotene concentrations tended to increase with advancing age, this being especially marked for serum beta-carotene levels in males. However, beta-carotene levels were high in females throughout the age range of 50-69 years. There was no significant change in serum level of lycopene with age. 2. There was no significant difference in intake frequency of foods containing large amounts of carotenoids among the groups with or without smoking and drinking, as serum alpha- and beta-carotene levels were closely associated with intake frequency of green-yellow vegetables. 3. Regular alcohol drinkers or current smokers showed lower serum beta-carotene concentrations, and the effect of alcohol drinking on serum carotene level seemed to be larger than that of smoking. A synergistic lowering action of smoking and drinking on serum beta-carotene level was suggested. Among the alcohol drinkers, the more cigarettes consumed per day, the lower the serum beta-carotene level was, but this was not the case among the non-drinkers. Ex-smokers showed intermediate values between current smokers and non-smokers. The results suggest that alcohol drinking and smoking habit might be associated with lower serum beta-carotene level, which in turn may be related to excess incidence of cancer among smokers or drinkers.

A workplace-based case-control study of gastric ulcer among male municipal employees in Japan

In order to detect risk factors of gastric ulcer among male workers in Japan, a workplace-based case-control study was conducted in a municipal government, using cases registered during 1981 to 1983 with individually matched controls. Statistically significant factors in univariate analysis were smoking, time interval from waking up to leaving home for job, meal time for supper, sleeping hours, anxiety, and gloomy feeling. Logistic analysis showed that among the above factors the significant relative risks were 11.9 (95% confidence interval: 1.6-89.4) for 1-9 cigarettes per day, 9.9 (2.6-37.7) for 10 cigarettes or more per day, and 5.3 (1.6-17.5) for gloomy feeling. These findings obtained among the male Japanese workers were almost consistent with those epidemiologic results in other developed countries that smoking and personality traits are major risk factors of gastric ulcer.

[Preoperative radiotherapy of carcinoma of the stomach and breast]

Sixty-one patients with gastric cancer and thirty-seven with breast cancer who had undergone preoperative radiotherapy were analysed retrospectively for assessment of various radiotherapeutic effects and prognosis. Most of the sixty-one patients with gastric cancer were found to be stage III or more with borderline operable lesions on admission. Of the sixty-one patients, sixteen were evaluated postoperatively to be stage I by histopathological examination. The 3-year survival rate in these sixteen patients was an admirable 60%. Of the thirty-seven patients with breast cancer, the 3-year survival rate among twenty-four in Stage III exceeded 90%. This survival rate is very high in comparison with other reports. For radiotherapy we adopted a less-fractionated irradiation method with a large dose instead of the conventional fractionated one. This irradiation method has not only a direct radiotherapeutic effect, but also produces a favorable effect on the host's immunocompetence. For gastric cancer, twice weekly treatment with 5 Gy and 3 Gy per week, and irradiation twice with 20 Gy and 10 Gy for breast cancer were very suitable preoperative irradiation doses.

Further characterization of a conserved actin-binding 27-kDa fragment of actinogelin and alpha-actinins and mapping of their binding sites on the actin molecule by chemical cross-linking

A conserved actin-binding domain (Mr = 27,000) of rat hepatic actinogelin, rat skeletal muscle, and chicken gizzard alpha-actinins (Mimura, N., and Asano, A. (1986) J. Biol. Chem. 261, 10680-10687) was separated into two components having different isoelectric points (peptides A and B) by chromatofocusing. Thermolysin digestion of peptide A generated peptide B with concomitant loss of peptide A. Amino acid compositions and tryptic maps of peptides A and B also demonstrated that peptide A is a precursor of peptide B upon thermolysin digestion. All of peptides A and B retained the activity to bind with F-actin competitively to each other. By the gel-filtration method, it was also shown that the native actin-binding 27-kDa fragments are monomeric and globular. The non-actin-binding 50- or 53.5-kDa fragment of actinogelin/alpha-actinins was, however, found to be asymmetric and dimeric in the native state. Chemical cross-linking of the 27-kDa fragment with F-actin with a water-soluble carbodiimide produced at least four different complexes (I-IV). Chemical cleaving analysis of the cross-linked products (complexes I and II) indicated that the 27-kDa fragment possesses two possible binding sites on actin at the NH2-terminal residues 1-12 (for complex I) and at residues spanning 86-119 or 123 (for complex II).

The long-term prognosis of patients gastrectomized for benign gastroduodenal diseases

To study the long-term prognosis after gastrectomy, a total of 6,662 gastrectomized patients who had been operated on for benign gastroduodenal diseases between 1965 and 1980 were followed up from September 1, 1984 to May 30, 1986. The final vital status for the observed period could not be confirmed in 493 patients (7.4%), giving a follow-up rate of 92.6%. The average observation period was 13.1 years. The mortality from total deaths was almost identical to that of the general population adjusted for sex, age, and time trends of mortality, except for lower mortality among males in the first five years after operation. The risk of cancer mortality at all sites was lower than that of the general population, mainly due to the lower mortality from stomach cancer. This trend was not affected either by the type of gastroduodenal disease or by the method of operation. However, lung cancer mortality among males was significantly higher and one of the reasons for that could be excess smoking by males.

[Family study of cancer among gastrectomized patients]

The purpose of this study was to examine whether patients with gastric cancer differ from those with benign gastroduodenal diseases in terms of familial disposition. This series consisted of 1,233 patients with gastric cancer and 2,200 patients with benign gastroduodenal diseases, who had had a gastrectomy between 1972 and 1979 in one hospital. The family information on cancer deaths of first and second relatives of the patients was obtained at the time of operation. The age-adjusted relative risk of positive family history of cancer was higher among the patients with gastric cancer than that among those with benign gastroduodenal diseases. The patients with diffuse type of cancer had a higher risk of positive family history than those with intestinal type of cancer. The non-cancer patients with family history had a slightly higher risk, although not statistical significant, to die from cancer than those without family history. Higher frequency of blood type A was seen in gastric cancer patients with positive family history. These results suggest that certain types of gastric cancer may seem to be associated with genetic factor.

[Three cases of adenocarcinoma of the lower esophagus and cardia showing marked regression after radiotherapy with FT-207]

Three cases of adenocarcinoma of the lower esophagus and cardia which is considered to be difficult to control by radiotherapy alone, were given radical irradiation combined with FT-207 suppository. Dosages of radiation and FT-207 were 70 Gy/35 f and 1.5 g/day (1 case) or 1.0 g/day (2 cases), respectively. The treatment was successful locally; dysphagia was improved in all cases and 1 case has shown no recurrence for a period of two and a half years. Side effects were leukopenia and hemorrhagic esophagitis in the case given 1.5 g/day of FT-207, but these were cured by conservative therapy. These results emphasize that radiotherapy combined with anticancer drugs should be considered as a local therapy for inoperable adenocarcinoma of the lower esophagus and cardia.