Mutated mitogen-activated protein kinase: a tumor rejection antigen of mouse sarcoma

The molecular basis of the polymorphic tumor rejection antigens of chemically induced sarcomas of inbred mice remains a mystery, despite the discovery of these antigens over 40 years ago and their critical importance to the foundation of tumor immunology. In an analysis of a panel of BALB/c 3-methylcholanthrene-induced tumors, we identified one tumor, CMS5, that elicited a strong cytotoxic T cell response with exquisite specificity for CMS5. A stable cloned line of T cells with this specificity (C18) was used to screen a CMS5 cDNA expression library. The gene encoding the C18-defined antigen was identified as a mutated form of a mouse mitogen-activated protein kinase, ERK2, and a peptide incorporating the resulting amino acid substitution (lysine to glutamine) was efficiently recognized by C18. Vaccination with this peptide elicited specific resistance to CMS5 challenge. Extensive efforts to isolate antigen-loss variants of CMS5 were unsuccessful, suggesting that the mutated mitogen-activated protein kinase is essential for maintenance of the malignant phenotype.

The optimal equilibration time for mouse embryos frozen by vitrification with trehalose

To determine the best equilibration time in the cryoprotectant before rapid cooling, 8-cell mouse embryos were exposed to a vitrification solution containing ethylene glycol, Ficoll and trehalose in modified phosphate-buffered saline at 5 degrees C for varying periods of time. They were frozen using an ultra rapid freezing method, thawed in a 20 degrees C water bath and cultured for 24 h with 5-bromo-2-deoxyuridine. Embryo development and the number of sister chromatid exchanges, a sensitive indicator of genetic damage, were observed. The results demonstrated that embryo development after freezing and thawing was similar among the groups exposed for periods of 5-40 min. However, the number of sister chromatid exchanges was significantly smaller in the group exposed for 5 min, indicating that this was the safest equilibration time in the vitrification solution.

Identification, characterization, and chromosomal organization of cell division cycle genes in Caulobacter crescentus

We report a detailed characterization of cell division cycle (cdc) genes in the differentiating gram-negative bacterium Caulobacter crescentus. A large set of temperature-sensitive cdc mutations was isolated after treatment with the chemical mutagen N-methyl-N'-nitro-N-nitrosoguanidine. Analysis of independently isolated mutants at the nonpermissive temperature identified a variety of well-defined terminal phenotypes, including long filamentous cells blocked at various stages of the cell division cycle and two unusual classes of mutants with defects in both cell growth and division. The latter strains are uniformly arrested as either short bagel-shaped coils or large predivisional cells. The polar morphology of these cdc mutants supports the hypothesis that normal cell cycle progression is directly responsible for developmental regulation in C. crescentus. Genetic and physical mapping of the conditional cdc mutations and the previously characterized dna and div mutations identified at least 21 genes that are required for normal cell cycle progression. Although most of these genes are widely scattered, the genetically linked divA, divB, and divE genes were shown by genetic complementation and physical mapping to be organized in one gene cluster at 3200 units on the chromosome. DNA sequence analysis and marker rescue experiments demonstrated that divE is the C. crescentus ftsA homolog and that the ftsZ gene maps immediately adjacent to ftsA. On the basis of these results, we suggest that the C. crescentus divA-divB-divE(ftsA)-ftsZ gene cluster corresponds to the 2-min fts gene cluster of Escherichia coli.

The expression of E-cadherin as a prognostic factor in breast cancer

We examined the clinical significance of E-cadherin expression in 98 patients with breast cancer. E-cadherin expression significantly correlated with histologic grade (p=0.0323) and tended to correlate with the absence of axillary lymph node metastases (p=0.0646). The expression of E-cadherin was associated significantly with the recurrence rate (p=0.0334) and marginally associated with disease-free (p=0.0597) but not overall survival, in univariate analysis. The association between E-cadherin expression and disease-free survival was lost in multivariate analysis. The prognostic value of E-cadherin expression in breast cancer appears to be limited. A larger, prospective study with long-term follow-up is needed.

Incidence of apoptotic bodies in membrana granulosa of the patients participating in an in vitro fertilization program

OBJECTIVE

To investigate the incidence of apoptotic bodies in mural granulosa cell masses and cumulus cell masses.

DESIGN

Nonrandomized, prospective study.

SETTING

Department of Obstetrics and Gynecology, Yamagata University School of Medicine, Yamagata, Japan.

PATIENT(S)

One hundred twenty-nine normally ovulating women underwent ovulation induction for IVF-ET with GnRH analogue (GnRH-a) and gonadotropins.

INTERVENTION(S)

Patients underwent follicle aspiration after the administration of hCG.

MAIN OUTCOME MEASURE(S)

The nuclei of recovered granulosa cells were examined by fluorescence microscopy and the incidence of apoptotic bodies was tabulated.

RESULT(S)

The incidence of apoptotic bodies was significantly higher in mural granulosa cell masses than in cumulus cell masses in the entire group of 129 patients. Both incidence of apoptotic bodies of mural granulosa cell masses and cumulus cell masses were significantly higher in patients with less than six follicular oocytes compared with patients with six or more oocytes. Nonpregnant patients showed significantly higher incidence of apoptotic bodies in mural granulosa cell masses compared with pregnant patients.

CONCLUSION(S)

These results indicate that mural granulosa cell masses and cumulus cell masses may have different functions in follicular maturation. The incidence of apoptotic bodies in mural granulosa cell masses can be used as an indicator of success of IVF.

An antibiotic, ascofuranone, specifically inhibits respiration and in vitro growth of long slender bloodstream forms of Trypanosoma brucei brucei

Ascofuranone, a prenylphenol antibiotic isolated from a phytopathogenic fungus, Ascochyta visiae, strongly inhibited both glucose-dependent cellular respiration and glycerol-3-phosphate-dependent mitochondrial O2 consumption of long slender bloodstream forms of Trypanosoma brucei brucei. This inhibition was suggested to be due to inhibition of the mitochondrial electron-transport system, composed of glycerol-3-phosphate dehydrogenase (EC 1.1.99.5) and plant-like alternative oxidase. Ascofuranone noncompetitively inhibited the reduced coenzyme Q1-dependent O2 uptake of the mitochondria with respect to ubiquinol (Ki = 2.38 nM). Therefore, the susceptible site is deduced to be the ubiquinone redox machinery which links the two enzyme activities. Further, ascofuranone in combination with glycerol completely blocked energy production, and potently inhibited the in vitro growth of the parasite. Our findings suggest that ascofuranone might be a promising candidate for the chemotherapeutic agents of African trypanosomiasis.

Treatment of ureteral and renal stones by electrohydraulic lithotripsy

Manipulation of ureteral and renal calculi can be done under direct vision using a fiberscope with increased safety and efficacy. We treated 207 ureteral and renal stones in 198 patients using electrohydraulic lithotriptor combined with transurethral fiberscope from July 1985 till January 1991. Electrohydraulic lithotripsy (EHL) successfully fragmented 187 out of 207 stones (90.3%). A total of 119 patients (57.5%) became stone-free 3 months after operation, which increased to 170 cases (82.1%) at a mean follow-up of 20 months. There were 6 ureteral perforations (4 due to fiberscope and 2 due to EHL spark damage to the ureteral mucosa), which were treated immediately by open operation (2.9%). In 7 cases (3.4%), the stone could not be fragmented due to its hardness. We believe electrohydraulic lithotropsy treatment combined with transurethral fiberscopy is a safe, effective, noninvasive and economical method for the treatment of urinary tract stones.

[A case of advanced gastric cancer showing complete disappearance of cancer cells in multiple liver metastases due to low-dose PMUE therapy]

A case of gastric cancer with liver metastasis who responded well to low-dose PMUE (CDDP, MMC, UFT, etoposide) therapy is reported. A 65-year-old man underwent distal partial gastrectomy with D2 lymph node dissection under the diagnosis of type 5 gastric cancer with multiple liver metastases. Pathological findings revealed papillary adenocarcinoma in the primary lesion and metastatic lymph nodes (No. 8a). Low-dose PMUE therapy after resection of primary lesion was effective for the liver metastases. Exacerbation was suspected, so the lesions of metastases were resected again after 2 years and 11 months postoperative course. All 4 resected lesions of metastases became old fibrous tissue with hyalinization, and 2 of 4 lesions were necrotic and surrounded by fibrous connective tissue. None of these 4 lesions included viable cancer cells. The patient has now been followed with no evidence of exacerbation. It was suggested that low-dose PMUE therapy was effective for liver metastasis of gastric cancer, especially the differentiated type.

An antibiotic, ascofuranone, specifically inhibits respiration and in vitro growth of long slender bloodstream forms of Trypanosoma brucei brucei

Ascofuranone, a prenylphenol antibiotic isolated from a phytopathogenic fungus, Ascochyta visiae, strongly inhibited both glucose-dependent cellular respiration and glycerol-3-phosphate-dependent mitochondrial O2 consumption of long slender bloodstream forms of Trypanosoma brucei brucei. This inhibition was suggested to be due to inhibition of the mitochondriai electron-transport system, composed of glycerol-3-phosphate dehydrogenase (EC 1.1.99.5) and plant-like alternative oxidase. Ascofuranone noncompetitively inhibited the reduced coenzyme Q1-dependent O2 uptake of the mitochondria with respect to ubiquinol (Ki = 2.38 nM). Therefore, the susceptible site is deduced to be the ubiquinone redox machinery which links the two enzyme activities. Further, ascofuranone in combination with glycerol completely blocked energy production, and potently inhibited the in vitro growth of the parasite. Our findings suggest that ascofuranone might be a promising candidate for the chemotherapeutic agents of African trypanosomiasis.

Immunocytochemical localization of aromatic L-amino acid decarboxylase and catechol-O-methyltransferase in blood vessel wall of the human dental pulp

Relative large amounts of DOPA as compared with the concentrations of norepinephrine are found in human dental pulp. AADC and COMT are localized in blood vessel walls of human dental pulp. This localization suggests a functional relationship between COMT and AADC with regard to the metabolism of DOPA.

Signal transduction in the cell cycle regulation of Caulobacter differentiation

Caulobacter crescentus differentiates to form a new cell type during asymmetric cell division. Recent results indicate that signal transduction pathways mediated by protein kinases and essential response regulators play a central role in the regulation of development and cell division in response to cell cycle checkpoints.

Nuclear encoding of a chloroplast RNA polymerase sigma subunit in a red alga

A chloroplast RNA polymerase sigma factor is encoded by a nuclear gene, sigA, in the red alga Cyanidium caldarium RK-1. The encoded protein functions as an RNA polymerase sigma factor in vitro and it is localized to the chloroplast in vivo. SigA shows high sequence similarity to the sigma factors of cyanobacteria, which is indicative of the ancestral endosymbiotic event and subsequent transfer of the sigA gene to the nuclear genome.

Irrelevance of the mutated p53 gene product to tumor rejection antigen in 3-methylcholanthrene-induced fibrosarcomas

The relevance of mutated p53 to in vivo rejection of MC-induced fibrosarcomas and/or in vitro CTL activity against these tumors was investigated. p53 gene was found to be altered in nine MC-induced fibrosarcomas of BALB/c origin. The mutated p53 cDNA derived from several MC-induced fibrosarcomas was transduced into CMS8 which lacks p53 expression. Immunization of mice with these mutated p53 transfectants failed to protect them from original MC-induced fibrosarcomas from which mutated p53 genes were derived. CTL lines specific for these MC-induced fibrosarcomas destroyed the original MC-induced fibrosarcomas, but not CMS8 transduced with mutated p53 genes derived from the same lines. A series of 9mer peptides consisting of mutated amino acid residues of p53 of Meth A, CMS17 and CMS9 were prepared, and target P1HTR cells were pulsed with them. None of CTLs for these fibrosarcomas were reactive with P1HTR pulsed with these peptides. In conclusion, peptides derived from mutated p53 genes may serve as target antigens for CD8(+) MHC class I restricted CTL as reported, but may often not contribute as target antigens to the rejection of MC-induced fibrosarcomas.

The effects of high dietary fat and indomethacin on 7,12-dimethylbenz(a)anthracene-induced mammary carcinomas in rats

The effects of high dietary fat and indomethacin (IND) on tumorigenesis, tumor growth, tumor histology, cell kinetics and receptor contents of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinomas were investigated in Sprague-Dawley (S-D) rats. Tumorigenesis was stimulated by high dietary fat and inhibited by IND. However, both high dietary fat and IND stimulated tumor growth. Switching the animals from the high-fat diet with or without IND to the low-fat diet suppressed tumor growth and affected the cell kinetics. Histologically, the tumors showed a dense proliferation of ductal cells in the high-fat alone or IND-treated high-fat diet group. Tumors in the low-fat or IND-treated low-fat group, as well as the group switched from a high-fat or IND-treated high-fat diet to a low-fat diet, demonstrated well-developed glandular structures. The estrogen receptor and progesterone receptor contents were not different between the groups either prior to or following switching diets. Therefore, high dietary fat stimulates tumorigenesis and tumor proliferation, while IND has dual effects: a stimulating effect on tumor proliferation, but an inhibiting effect on tumorigenesis. It also appears that hormone-receptor status does not play an important role in the stimulatory effects of high-fat diet or IND on tumor proliferation.

The fate of Mn2+ ions inside Saccharomyces cerevisiae cells seen by electron paramagnetic resonance

The fate of Mn2+ inside Saccharomyces cerevisiae cells was monitored during import and export processes, using information from electron paramagnetic resonance (EPR) spectroscopy analysis. EPR spectra showed that when entering the cell in high number, manganese ions immediately precipitated. If recorded under conditions that favored manganese efflux, EPR spectra indicated that only osmotically free ions were exported and that bound manganese had to turn into the soluble form before being able to leave the cell.

Purification, characterization and molecular cloning of Cha o 1, a major allergen of Chamaecyparis obtusa (Japanese cypress) pollen

Pollen of Chamaecyparis obtusa (Japanese cypress) is one of the causes of allergic pollinosis in Japan. A major allergen of the pollen designated Cha o 1, was purified by two-step ion exchange chromatography. Cha o 1 was separated into four components with molecular masses of 48.5 kDa and 52.0 kDa, each with pIs of 6.77 and 6.82. The 23-residue N-terminal sequence of Cha o 1 was determined and shown to have high identity with that of Cry j 1, a major allergen of Cryptomeria japonica pollen. cDNA coding for Cha o 1 was cloned by hybridization screening using Cry j 1 cDNA as a probe. One of the cDNA clones, pCHA-1 was sequenced and found to code for a putative 21-residue signal peptide and a 354-residue native protein with a derived molecular mass of 38.1 kDa. The deduced amino acid sequence of Cha o 1 showed 79-80% identity with those of Cry j 1. These findings were consistent with observations of a close crossreaction between the two allergens. Homology analyses revealed that Cha o 1 had 46-49% identity with Amb a 1 families and Amb a 2, the major allergens of short ragweed. Cry j 1 has pectate lyase enzyme activity, suggesting that Cha o 1 may have the same enzyme activity as Cry j 1.

Elevated levels of soluble Fc epsilon RII/CD23 and antibodies to Epstein-Barr virus in patients with Sjögren's syndrome

To clarify how Epstein-Barr virus (EBV) infection is responsible for Sjögren's syndrome (SjS) we measured both IgG and IgM antibodies to viral capsid antigen (VCA) of EBV in the sera of normal healthy subjects and patients with SjS. Anti-VCA IgG was detectable in all controls and patients however, anti-VCA IgG titers in the sera of SjS patients were significantly higher than those of the controls (p < 0.01). No anti-VCA IgM was detected in the sera of controls whereas anti-VCA IgM was detected in the sera from 10 out of the 13 patients with SjS. This suggests that SjS might be associated with EBV. The serum levels of sCD23 (IgE-binding factor) were also measured to assess the differential state in patients with SjS. The sCD23 level of normal individuals was 211.26 +/- 12.01 micrograms/L (value is mean +/- SE), and was 443.77 +/- 71.94 micrograms/L in the 13 patients with SjS. The mean sCD23 level in the 9 patients with SjS without any complication was 360.67 +/- 35.63 micrograms/L. In the patients with SjS, sCD23 levels were significantly higher than those in the normal individuals (p < 0.01).

Epitope analysis of HLA-DR-restricted helper T-cell responses to Der p II, a major allergen molecule of Dermatophagoides pteronyssinus

T-cell epitopes of Der p II, a major allergen of Dermatophagoides pteronyssinus, were analyzed by using human T-cell clones. We tested 38 cloned T cells from two Japanese patients with allergic rhinitis, and identified at least two peptides (K33-T47 and I58-C73) as helper T-cell epitopes. The former epitope was shown to be restricted by HLA-DRB1*1502, and the latter by HLA-DRB1*0405, both of which are typical Japanese HLA-DR alleles, suggesting that those T-cell epitopes might be important for the onset of house-dust mite allergy in the Japanese population. We prepared 15 analog peptides of the HLA- DRB1*1502-restricted 15-mer peptide. Of those 15 residues, five (F35, L37, A39, F41, and E42) were critical for the epitope activity, and three residues (F35, A39, and E42) seemed to be included in anchor motifs for HLA-DRB1*1502. The epitope peptide was also recognized by HLA-DRB1*1502-positive healthy donors; however, only allergic T cells showed Th2 functions. Antigen-presenting cells of nonallergic donors were able to activate allergic T cells to express Th2 function. This seemed to suggest that antigen recognition of T cells, as well as additional unknown factors which promote Th2, rather than Th1, responses, might be important for the onset of house-dust mite allergy.

Experimental model of chronic tonsillar herniation associated with early stage syringomyelia

This report describes an experimental model of chronic tonsillar herniation and its effects on the spinal cord. In ten rats, a small piece of chemically induced mammary cancer was transplanted to the supraoccipital bone. In all cases, the transplanted cancers grew into the posterior fossa, destroying the supraoccipital bone and compressing the cerebellum extradurally. In six of the ten rats, tonsillar herniation was observed at 8-14 weeks after transplantation. Transdural infiltration of the tumor cells was not apparent in any animal. In those rats with tonsillar herniation (n = 6), the spinal cord from the C5 to the T8 segments showed enlargement of the central canal without exception. Histological examination revealed the following changes: stretching and thinning of the ependymal cells; swelling of the astrocytic processes; and extra-cellular edema, predominantly in the dorsal gray matter, but also in the ventral inner portion of the dorsal column. In the control group (n = 4) and those rats without tonsillar herniation (n = 4), such histological changes of the spinal cord were not observed. Although the lesions can not be regarded as representing mature syringomyelia, they most likely constitute an earlier evolutionary stage.