Lack of association between variants of the angiotensinogen gene and the risk of coronary artery disease in middle-aged Japanese men

The renin-angiotensin system is important in cardiovascular remodeling. Although a variant of the angiotensinogen gene is associated with an increased generation of angiotensinogen, it is unclear how this genetic variant might influence the activity of the renin-angiotensin system and thereby contribute to the predisposition to coronary artery disease (CAD). The relation between genetic polymorphisms in the gene-encoding angiotensinogen and the risk of CAD in middle-aged Japanese men was investigated. Two polymorphisms in exon 2 of the angiotensinogen gene, M235T and T174M, were analyzed in 327 patients with CAD and 352 matched control subjects. The genotype distribution of both polymorphisms did not differ between patients with CAD and control subjects. No combination of genotypes of the two polymorphisms was associated with CAD. Results indicate that the M235T and T174M variants of the angiotensinogen gene are not associated with CAD in Japanese men.

Association of a deletion polymorphism of the angiotensin-converting enzyme gene with left-ventricular hypertrophy in Japanese women with essential hypertension; multicenter study of 1,919 subjects

The relationship of an insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene to left-ventricular hypertrophy in individuals with essential hypertension (EH) was investigated in a large population of Japanese men and women. The ACE genotype of 762 subjects with EH (425 men and 337 women) and 1,157 healthy controls (604 men and 553 women) was determined by polymerase chain reaction analysis. The distribution of ACE genotypes did not differ significantly between patients with EH and control in both men and women. For women with EH, the DD genotype was positively associated with the thickness of the interventricular septum and inversely associated with the left ventricular end-diastolic dimension, both determined by echocardiography. In contrast, the DD genotype was not associated with any echocardiographic parameter in men with EH. These results indicate that the DD genotype is a risk factor for left-ventricular hypertrophy in Japanese women with EH, but not for Japanese men.

Long-term culture of primary rat hepatocytes on heparin- or lambda carrageenan-containing collagen gels

The interactions of glycosaminoglycans (GAGs) with collagen are thought to be important in cell adhesion and cell differentiation. To investigate whether the interactions of GAG or sulfated polysaccharide with collagen can maintain the functions of cultured primary rat hepatocytes, GAG- or sulfated polysaccharide-containing collagen gels were reconstituted in vitro and used for culture of hepatocytes. Among the GAGs and sulfated polysaccharides examined, heparin- and lambda carrageenan-containing collagen gels were found to be able to stimulate and sustain albumin synthesis, while the other GAG- or sulfated polysaccharide-containing collagen gels had almost no effect on maintenance of albumin synthesis. In the cultures using collagen gels that contained 400 micrograms/ml heparin or 100 micrograms/ml lambda carrageenan, albumin synthesis by rat hepatocytes was prolonged to about 4 and 5 weeks, respectively, but albumin synthesis was kept up for only one week in the cultures using conventional collagen gels. These results suggest that the interactions of heparin or lambda carrageenan might be of importance for long-term maintenance of hepatocyte functions.

Synthesis and antitumor activity of water-soluble enediyne compounds related to dynemicin A

The enediyne compounds 9-14, simple dynemicin A (1) analogues equipped with aryl carbamate moieties with various aliphatic amino or hydroxy groups at the C9 position, were synthesized and evaluated for DNA-cleaving ability, in vitro cytotoxicity, and in vivo antitumor activity. We found that the water-soluble compounds, in which the tert-amines such as the 2-(dimethylamino)ethyl (10b, 14b), 2-(pyrrolidino)ethyl (10c), or 1-azabicyclo[3.3.0]oct-5-ylmethyl (10d, 12d, 14d) group were attached, showed not only the enhanced in vivo antitumor activity but also the decreased toxicity compared to the corresponding 9-acetoxy enediyne compounds 6-8. In particular, compound 10c showed the most enhanced in vivo antitumor activity (T/C = 222% at a daily dose of 1.25 mg/kg for 4 days) at about half of the dose of 6. These results suggest that both the enhanced antitumor activity and the reduced toxicity might be due to the improved bioavailability or disposition of compounds 6-8 by their water-solubilization.

Interferons suppress mitochondrial gene transcription by depleting mitochondrial transcription factor A (mtTFA)

Mitochondrial gene transcription activity in organello was suppressed after culturing HeLa cells with 1000 U/ml of interferon-alpha (IFN-alpha) or IFN-gamma for 18 h. The suppression was associated with reduced levels of mitochondrial gene transcripts. Northern blot analysis of HeLa cell RNA showed marked reduction of the mRNA encoding for mitochondrial transcription factor A (mtTFA). Immunoblotting with antiserum directed against recombinant mtTFA showed a reduced level of the protein as well. Consistently, gel-retardation assay of mitochondrial extract showed reduced level of functional mtTFA, which is known to bind to both heavy and light strand promoters of bidirectionally transcribed mitochondrial DNA. We suggest that depletion of mtTFA is a pathway through which IFNs depress the mitochondrial respiration.

Structure-activity relationships of cyclic enediynes related to dynemicin A. II. Synthesis and antitumor activity of 9- and 12-substituted enediynes equipped with aryl carbamate moieties

Novel enediyne compounds 4-8, simple analogues of dynemicin A (1) equipped with the phenyl or 4-chlorophenyl carbamate moiety, were synthesized and evaluated for DNA-cleaving ability, in vitro cytotoxicity, and in vivo antitumor activity. As a result of the SAR study, it was revealed that the size and character of the substituents (R1 and R2) at the C9 position critically influenced both the stability and antitumor activity of the enediyne compounds. We found that the 9-deoxy compound 6a, a stable and less bulky enediyne having a hydrogen as the R1 and R2 substituents, showed a significant in vivo activity with a T/C of 215% at a daily dosage of 2.0 mg/kg for 4 days. The incorporation of an oxygen-containing functional group as the R3 substituent on a benzene ring resulted in considerable abolishing of both the in vitro and in vivo potencies. In a series of 9-acyloxy compounds, incorporation of the basic aromatic moiety such as 8e was effective for the in vitro activity, but it was ineffective for the in vivo activity. Furthermore, for the stereochemistry-activity relationships at the C9 position, the (9R*)-isomers of 8c, 8e, and 8f were found to show higher both in vitro and in vivo than the corresponding (9S*)-isomers. For the mechanistic studies, compound 6a underwent Bergman cycloaromatization via a diradical pathway under acidic conditions, whereas it scarcely showed DNA-cleaving activity due to the chemical stability of the aryl carbamate moiety under neutral conditions.

Structure-activity relationships of cyclic enediynes related to dynemicin A. I. Synthesis and antitumor activity of 9-acetoxy enediynes equipped with aryl carbamate moieties

A series of the 9-acetoxy enediyne compounds, 6a-k which were simplified from natural dynemicin A, and designed to be equipped with various aryl carbamate moieties, was synthesized and evaluated for DNA-cleaving ability, in vitro cytotoxicity, and in vivo antitumor activity. As a result of this study of the structure-activity relationships (SAR) with regard to the Rt substituent, both compounds 6a and 6f with the phenyl carbamate and 4-chlorophenyl carbamate moiety, respectively, were found to exhibit significant activity (T/C > 200%) against murine P388 leukemia in mice, in spite of having IC50 values in the micromolar range. In particular, compound 6f showed the most potent activity with a maximum T/C of 256% at a daily dosage of 4.0 mg/kg for four days. Furthermore, both compounds 6a and 6f were effective against Meth A sarcoma in mice and inhibited 71 and 77% of the tumor growth at 2.0 and 3.0 mg/kg dosages, respectively. In contrast to 6f, compound 6i possessing the 2-nitrophenyl carbamate moiety showed only a slight in vivo activity, while it had about one order of magnitude higher in vitro cytotoxicity than 6f. For the stereochemistry-activity relationships at the C9 position, the (9R*)-isomers of 6c, 6g, and 6j were found to show higher in vitro and in vivo potencies than the corresponding (9S*)-isomers.

Synthesis and biological evaluation of novel cyclic enediyne compounds related to dynemicin A as antitumor agents

Novel cyclic enediyne compounds, which are simple functional analogs of dynemicin A (1) having the bicyclo-[7.3.1]tridec-4-ene-2,6-diyne system, were synthesized and evaluated for the DNA-cleaving ability, in vitro cytotoxicity and in vivo antitumor activity. All of the sulfones 19-24, which were equipped with a 2-(arylsulfonyl)-ethoxycarbonyl group or the 2-(methylsulfonyl)ethoxycarbonyl group as a triggering device, showed both potent DNA-cleaving activity and cytotoxicity against various tumor cell lines. However, these compounds were entirely inactive or only slightly active against murine P388 leukemia in mice. On the other hand, the enediyne 2a having a phenyl carbamate moiety as a stable N-protecting group showed effective antitumor activity both in vitro and in vivo. In particular, it exhibited significant antitumor activity against Lewis lung carcinoma in mice. These results show that the character of the carbamate moiety of the cyclic enediynes strikingly affects their biological activities, that is, the sulfonylethyl carbamate moiety is an effective triggering device for both DNA-cleaving activity and cytotoxicity, and the phenyl carbamate moiety is significant for antitumor activity in vivo. As part of a mechanistic study, the reactivities of 2a and 21 were examined under a weakly basic condition (pH 9.3); both compounds failed to give the Bergman cycloaromatization product.

[A new solid-phase extraction method for human urinary 3-methoxy-4-hydroxyphenylethyleneglycol]

A new solid-phase extraction procedure for urinary 3-methoxy-4-hydroxy-phenylethyleneglycol (MHPG) was established. Sep-Pak Diol cartridge was used, because MHPG is a neutral and alcoholic compound. Aqueous samples were adsorbed to the cartridge, then MHPG was eluted by the addition of ethyl acetate. After the eluate was evaporated, the residuum was dissolved with HPLC mobile phase and injected into HPLC. The extraction procedure was highly specific to MHPG, and none of other acidic catecholamine metabolites, such as vanillylmandelic acid (VMA), homovanillic acid (HVA) and 3,4-dihydroxyphenylacetic acid (DOPAC), was extracted. The recovery of MHPG using this method was over 90% and higher than those using previously described methods such as liquid-liquid extraction with ethyl acetate. Of the three vanillyl alcohol isomers, isovanillyl alcohol was the most suitable as an internal standard for the correction of column-to-column variation of the recovery. Human urinary unconjugated MHPG extracted by the new procedure could be measured by HPLC with a fluorescence detection. Further complicated derivatization and more sensitive detection systems, such as GC-MS and HPLC-electrochemical detector (ECD), were not needed due to high selectivity and high recovery of the extraction procedure. In addition, the urinary total (conjugated plus unconjugated) MHPG content could also be determined by the same procedure after an enzymatic hydrolysis of conjugated MHPG. The newly developed extraction procedure was simple, rapid and highly specific, and might be applicable to the analysis of MHPG in various body fluids.

Increased susceptibility to primary infection with Listeria monocytogenes in germfree mice may be due to lack of accumulation of L-selectin+ CD44+ T cells in sites of inflammation

The host defense of germfree (GF) mice against primary infection with Listeria monocytogenes was compared with that of specific-pathogen-free (SPF) mice. In SPF mice, the numbers of bacteria in the peritoneal cavity, liver, and spleen decreased gradually to undetectable levels by day 8 after intraperitoneal infection with a sublethal dose (2 X 10(3) CFU) of L. monocytogenes. On the other hand, the elimination of bacteria in these organs of GF mice was significantly impaired at this stage after inoculation. We have reported previously that T cells coexpressing L-selectin and CD44 play an important role in protection against L. monocytogenes through trafficking to sites of inflammation. Consistent with our previous findings, the number of unique L-selectin+ CD44+ T cells in the peritoneal cavity was remarkably increased on day 8 after infection in SPF mice, whereas such an increase was not evident in GF mice at this stage. Listeria-specific T-cell proliferation was normally detected in the lymph node cells of GF mice inoculated with L. monocytogenes, whereas the T-cell-proliferative response of the peritoneal exudate cells of GF mice was significantly impaired compared with that of SPF mice. These results suggest that the priming of T cells against listerial antigens normally occurs in the peripheral lymphoid organs of GF mice but the trafficking of the activated T cells to the inflamed sites may be severely impaired in GF mice, resulting in increased susceptibility to infection with L. monocytogenes.

Gastric syphilis: polymerase chain reaction detection of treponemal DNA in pseudolymphomatous lesions

Syphilis is an unexpected diagnosis in the stomach. To establish the diagnosis, evidence of Treponema pallidum in the gastric lesion is necessary. However, it is sometimes difficult to prove the presence of the organisms by conventional methods. The authors describe two cases of early gastric syphilis with pseudolymphomatous histology in which T pallidum gene was detected by the polymerase chain reaction (PCR) using paraffin biopsy sections. The gastric lesion of each case endoscopically and histologically simulated that of malignant lymphoma. However, no clonality was proved by immunohistochemistry or PCR gene rearrangement analysis. No spirochetal organisms were detected with certainty by Warthin-Starry silver stain, whereas the organisms were shown by immunofluorescent stain in one patient. A PCR study showed the treponemal DNA in both patients, and its validity was supported by a direct sequencing and a restriction enzyme digestion. Positive results of serological tests for syphilis and regression of the lesions after antisyphilitic treatment were confirmatory of the diagnosis. Gastric syphilis should be considered as a differential diagnosis when an atypical lymphoid infiltrate fails to show monoclonality. The present PCR method would be helpful in showing T pallidum using routinely processed small biopsy specimens as the tissue source.

Interleukin (IL)-1 beta, IL-2, IL-4, IL-6 and transforming growth factor-alpha levels are elevated in ventricular cerebrospinal fluid in juvenile parkinsonism and Parkinson's disease

Interleukin (IL)-1 beta , IL-2, IL-4, IL-6, epidermal growth factor (EGF), and transforming growth factor (TGF)-alpha were measured for the first time in ventricular cerebrospinal fluid (VCSF) from control non-parkinsonian patients, patients with juvenile parkinsonism (JP) and patients with Parkinson's disease (PD) by highly sensitive sandwich enzyme immunoassays. All cytokines were detectable in VCSF from control and parkinsonian patients, and the concentrations were much higher than those in lumbar CFS. The concentrations of IL-1 beta, IL-2, IL-4 and TGF-alpha in VCSF were higher in JP than those in controls (P < 0.05). In contrast, the concentrations of IL-2 and IL-6 in VCSF from patients with PD were higher than those from control patients (P < 0.05). These results agree with our previous reports, in which the cytokine levels were elevated in the striatal dopaminergic region of the brain from patients with PD. Since VCSF is produced in the ventricles, the alteration of cytokines in VCSF may reflect the changes of cytokines in the brain. Because cytokines play an important role as mitogens and neurotrophic factors in the brain, the increases in cytokines as a compensatory response may occur in the brain of patients of JP or PD during the progress of neurodegeneration. Increase in cytokines may contribute not only as a compensatory response but as a primary initiating trigger for the neurodegeneration.

Induction of apoptosis in primary culture of rat hepatocytes by protease inhibitors

There is growing evidence that suggests the involvement of intracellular proteases in the process of apoptosis or programmed cell death. In this study, we have demonstrated that leupeptin, a cysteine protease inhibitor, can significantly increase the incidence of both apoptotic nuclear morphology change and internucleosomal DNA fragmentation in primary cultured hepatocytes in the absence of known apoptotic stimuli for hepatocytes. On the other hand, aspartic and serine protease inhibitors showed little or no effects on the apoptotic changes. In addition, we found that the apoptotic changes could be induced by chloroquine, an inhibitor of lysosomal proteolysis, but could not be induced by calpain inhibitors. These data suggest that inhibition of lysosomal cysteine proteases may induce apoptosis in primary cultured hepatocytes.

A large DNA-binding nuclear protein with RNA recognition motif and serine/arginine-rich domain

cDNA species encoding a large DNA-binding protein (NP220) of 1978 amino acids was isolated from human cDNA libraries. Human NP220 binds to double-stranded DNA fragments by recognizing clusters of cytidines. Immunofluorescent microscopy with antiserum directed against NP220 revealed a punctate or "speckled" pattern and coiled body-like structures in the nucleoplasm of various human cell lines. These structures diffused in the cytoplasm during mitosis. Western blot analysis showed that NP220 is enriched in the lithium 3,5-diiodosalicylate-insoluble fraction of nuclei. The domain essential for DNA binding is localized in C-terminal half of NP220. Human NP220 shares three types of domains (MH1, MH2, and MH3) with the acidic nuclear protein, matrin 3 (Belgrader, P., Dey, R., and Berezney, R. (1991) J. Biol. Chem. 266, 9893-9899). MH1 is a 48-amino acid sequence near the N terminus of both human NP220 and rat matrin 3. MH2 is a 75-amino acid sequence homologous to the RNA recognition motifs of heterogeneous nuclear RNP I and L. It is repeated three times in NP220 and twice in matrin 3. MH3 is a 60-amino acid sequence at the C terminus of both NP220 and matrin 3. NP220 has an arginine/serine-rich domain commonly found in pre-mRNA splicing factors. Close to the domain essential for DNA binding, there are nine repeats of the sequence LVTVDEVIEEEDL. Thus, NP220 is a novel type of nucleoplasmic protein with multiple domains.

Evaluation of cross-sensitization among dye-intermediate agents using a modified lymphocyte transformation test

We evaluated cross-sensitization between p-phenylenediamine (pPDA) and p-aminophenol (pAP) or m-phenylenediamine (mPDA) by a modified lymphocyte transformation test. Guinea pigs were sensitized with pPDA using the maximization test procedure. Lymph node cells from the animals were then cultured with pPDA, pAP or mPDA in the presence or absence of epidermal cells (EC). Transformed lymphocyte counts were evaluated by means of 3H-thymidine uptake. Non-sensitized guinea pigs were used as controls. Blastogenesis in lymphocytes from sensitized guinea pigs was enhanced when cultured with pPDA, pAP or mPDA in the absence or presence of EC than without the sensitizers, and the extent of response depended on the concentration of pPDA, pAP or mPDA added to the cultures. Blastogenesis in lymphocytes from control animals was not significantly enhanced in response to pPDA, pAP or mPDA in the presence or absence of EC. The extent of the response to pPDA was greater than that to pAP, which in turn was greater than that to mPDA. In contrast, because pPDA, pAP and mPDA are color developing agents, cross-sensitization between pPDA and pAP or mPDA could not be evaluated by the results of an in vivo challenge due to pigmentation in the patch application sites. The results suggested that there is cross-sensitization between pPDA and pAP or mPDA, and that the modified lymphocyte transformation test is a useful predictive means of detecting cross-sensitization among chemicals, especially for color developing agents.

Transient giant negative T wave in acute anterior myocardial infarction predicts R wave recovery and preservation of left ventricular function

OBJECTIVE

To investigate the value of a giant negative T wave (> or = 1.0 mV) in precordial leads of 12-lead electrocardiograms in the acute phase of Q wave myocardial infarction as a predictor of myocardial salvage.

METHODS

Coronary angiographic and electrocardiographic findings, left ventricular ejection fraction in the chronic stage, and levels of cardiac enzymes were compared in patients with myocardial infarction with (group GNT, n = 31) and without (group N, n = 20) a giant negative T wave. GNT patients were divided into two subgroups according to the presence (GNT:R[+], n = 10) or absence (GNT: R[-], n = 21) of R wave recovery with an amplitude > or = 0.1 mV in at least one lead that had shown Q waves.

RESULTS

The maximum level of creatine kinase and the total creatine kinase were lower in group GNT compared with group N (P < 0.05). The left ventricular ejection fraction was higher in group GNT than in group N (P < 0.05). The maximum creatine kinase and total creatine kinase were lower in GNT:R(+) than in GNT:R(-) (P < 0.01). The left ventricular ejection fraction was higher in GNT:R(+) than in GNT:R(-) (P < 0.01). The frequency of R wave recovery was significantly higher when giant negative T waves appeared within 100 h of myocardial infarction or when the maximum potential was > or = 1.4 mV. The appearance of a giant negative T wave > or = 1.4 mV had a sensitivity of 90%, a specificity of 71.4%, a diagnostic accuracy of 77.4%, a positive predictive value of 60%, and a negative predictive value of 93.8% for prediction of R wave recovery.

CONCLUSIONS

The appearance of a giant negative T wave, especially within 100 h of the onset of myocardial infarction, with a maximum potential of > or = 1.4 mV, may predict a reappearance of the R wave and a better left ventricular function in patients in the chronic stage of anterior myocardial infarction.

Osteonectin gene expression in fibrotic liver

Osteonectin is an extracellular matrix (ECM) protein which is secreted by various cell types, and regulates tissue remodeling and cell proliferation. In the present study, we have examined the expression of osteonectin in fibrotic liver. Osteonectin transcripts were undetectable in normal liver, however, the abundant expression of the osteonectin gene was detected in fibrotic liver. The transcripts of osteonectin were only detected in hepatic lipocytes and the number of lipocytes was increased in fibrotic liver. These results suggested that in fibrotic liver, enhanced osteonectin expression may play an important role in liver fibrosis.

Evaluation of contact sensitivity to formaldehyde and tetramethylthiuram monosulfide using a modified lymphocyte transformation test

To examine the validity of a modified lymphocyte transformation test for evaluating contact hypersensitivity from weak sensitizers, guinea pigs were sensitized with formaldehyde (F) or tetramethylthiuram monosulfide (TMTM) using the maximization test procedure. Lymph node cells from the animals were then cultured with F or TMTM, in the presence or absence of epidermal cells (EC). Transformed lymphocyte counts were evaluated by uptake of 3H-thymidine. Nonsensitized guinea pigs were used as controls. The lymphocytes from sensitized guinea pigs showed stronger blastogenesis when cultured with F or TMTM in the presence of EC than when the sensitizers were not added to the culture and the response depended on the concentration of F or TMTM. Cultures in the absence of EC also showed significant enhancement of blastogenesis by F or TMTM, but the responses were significantly weaker than those in the presence of EC. Lymphocytes from the control animals did not show significantly enhanced blastogenesis in response to F or TMTM, even when EC was added to the cultures. The results suggested that contact sensitivity for weak sensitizers can be evaluated by this modified lymphocyte transformation test, especially when lymph node cells were co-cultured with EC.

Insertion of a novel transposable element in the tyrosinase gene is responsible for an albino mutation in the medaka fish, Oryzias latipes

In the medaka fish (Oryzias latipes) many mutants for body color have been isolated. A typical example is the recessive oculocutaneous albino mutant i, which has amelanotic skin and red-colored eyes with no tyrosinase activity. To cast light on the molecular basis of the albino mechanism, we performed Southern blot analysis of genomic DNA from the mutant with an authentic tyrosinase gene probe; the results demonstrate that an extra 1.9 kb fragment is present inside the first exon. The insertion is responsible for the oculocutaneous albinism. About 80 copies of this fragment are present in the genomes of albino-i and wild-type fish; these repeated sequences are here designated Tol1 elements and the particular element found in the tyrosinase gene of albino-i is denoted Tol1-tyr. The nucleotide sequence of Tol1-tyr shows that the fragment (i) carries terminal inverted repeats of 14 bp, and (ii) is flanked by duplicated 8 bp segments of the host chromosome. These are properties of DNA-mediated transposable elements. Comparison of the nucleotide sequence of Tol1-tyr with other sequences in DNA databases, with special attention to sequences of transposable elements known to date, did not reveal any similarity. Thus, Tol1 constitutes a hitherto unknown family of DNA transposable elements.

Differential expression of transforming growth factor-alpha and epidermal growth factor during postnatal development of rat submandibular gland

The concentration and the localization of transforming growth factor (TGF)-alpha and epidermal growth factor (EGF) in the submandibular glands (SMGs) of male Wistar rats of different ages (postnatal 0 to 10 weeks of age) were examined. Highest levels of TGF-alpha were seen early, at postnatal day 0; the levels dropped thereafter in an age-dependent manner, while EGF was not detectable before the third postnatal week. Immunoreactive localization of EGF was restricted to the granules of the granular convoluted tubule (GCT) cells in the mature SMGs, whereas TGF-alpha was observed throughout postnatal development over the entire duct system. TGF-alpha was demonstrated in the cytoplasm at early stages when the GCT granules were not observed and was also located on the granules at the late stage, as was the case for EGF, indicating that TGF-alpha is colocated with EGF in the mature SMG. These results demonstrate the differences between the expression of TGF-alpha and that of EGF in the developing rat SMG.

DNA fragmentation induced in high-cell-density culture of primary rat hepatocytes is an active process dependent on energy availability, gene expression, and calmodulin

We previously reported that internucleosomal DNA fragmentation, a biochemical feature of apoptosis, was induced spontaneously in high-cell-density culture of adult rat hepatocytes. To understand better the intracellular mechanism of the DNA fragmentation in this system, we have examined the effects of several inhibitors of specific intracellular functions on the DNA fragmentation. We found that the DNA fragmentation could be suppressed by treatment of the cells with inhibitors of mitochondrial respiration, KCN and CCCP, or a protein synthesis inhibitor, cycloheximide. We also demonstrated that calmodulin inhibitors, chlorpromazine and W-7, could suppress the DNA fragmentation. Together, these results lead us to conclude that the DNA fragmentation in hepatocytes cultured at high cell density is an active process dependent on energy availability, gene expression, and calmodulin, rather than a passive event resulting from necrosis. However, by analyzing the incidence of apoptotic morphology during culture, we found that only 2-3% of cells exhibited apoptotic morphology, while the incidence of DNA fragmentation was estimated to be much higher. Based on these results, we estimated that the DNA fragmentation may result from the incomplete progression of apoptosis or from the occurrence of another type of active cell death.

Transforming growth factor-alpha in human submandibular gland and saliva

A sensitive sandwich enzyme immunoassay (EIA) for transforming growth factor-alpha (TGF-alpha) utilizing a polyclonal antibody that recognizes limited epitopes of both human TGF-alpha and rat TGF-alpha in combination with a monoclonal anti-TGF-alpha IgG1 galactosidase conjugate was developed. This assay shows no cross-reactivity with human epidermal growth factor. We can quantify the TGF-alpha level in not only human TGF-alpha (detection limit: 1 pg/ml), but also rat TGF-alpha (detection limit: 10 pg/ml) by virtue of cross-reactivity. Employing this assay system, we demonstrated that TGF-alpha is present in both human submandibular glands and submandibular/sublingual saliva.

p53 protein and proliferating cell nuclear antigen in eccrine poroma and porocarcinoma. an immunohistochemical study

The expression of p53 protein and proliferating cell nuclear antigen (PCNA) in 18 eccrine poromas and four porocarcinomas was examined by immunohistochemistry. Immunoreactivity for p53 in eccrine poromas was negative in five tumors, < 10% of tumor cells in one (low expresser), 10-50% in seven (moderate expressers), and > 50% in five (high expressers). The duration of the presence before excision of p53-negative poromas was shorter, and the size of these tumors was smaller in comparison with those of p53-positive poromas. Moreover, all high expressers showed some atypical cells in limited areas. Of the four porocarcinomas, three were high expressers and one a low expresser of p53 protein. The low-expresser tumor showed clinically more rapid growth and histologically no poromatous foci in contrast to the high expressers. No significant correlation was found between p53 protein expression and PCNA positive staining in either eccrine poromas or porocarcinomas. However, the percentages of PCNA-positive cells in porocarcinomas were significantly higher than those in poromas, with no overlapping values. These results suggest that the PCNA index is useful in differentiating between poroma and porocarcinoma and that p53 gene mutation may occur in long-standing eccrine poromas and correlate with atypical changes in histology as well as subsequent progression to porocarcinoma.

p53 protein expression and p53 gene mutation in thymic epithelial tumors. An immunohistochemical and DNA sequencing study

p53 protein expression in 34 thymic epithelial tumors was examined immunohistochemically, and p53 gene mutation was detected in selected cases by DNA sequencing, using formalin-fixed and paraffin-embedded tissues. The tumors comprised 12 noninvasive thymomas, 9 invasive/metastatic thymomas, and 13 thymic carcinomas. All the tumors were immunoreactive for p53 protein. The p53-positive tumor cells in noninvasive thymoma were less than 10% (low expressor) in 7 cases and 10% to 50% (moderate expressor) in 5 cases. In invasive/metastatic thymoma, two were low expressors and seven were moderate expressors. In thymic carcinomas, there were nine moderate expressors and four high expressors (with > 50% positive cells). There was significant difference in p53 protein immunopositivity between thymic carcinoma and each of the noninvasive or invasive/metastatic thymomas. The DNA sequencing study confirmed the presence of p53 gene point mutation in all 10 cases examined, including three low expressors. These results suggest that p53 gene mutation is an early event in thymic tumorigenesis, and the p53 protein-positive cells increase with the progression of the tumor. Immunostaining reactivity of p53 may be a useful adjunct to differentiate thymic carcinoma from thymoma.