RESUMO
BACKGROUND AND PURPOSE: Protein tyrosine phosphatase receptor type Q (PTPRQ) was extracted from the cerebrospinal fluid (CSF) of patients with probable idiopathic normal-pressure hydrocephalus (iNPH) by proteome analysis. We aimed to assess the feasibility of using CSF PTPRQ concentrations for the additional diagnostic criterion of iNPH in Japanese and Finnish populations. METHODS: We compared PTPRQ concentrations among patients with probable iNPH and neurologically healthy individuals (normal control [NC] group), patients with normal-pressure hydrocephalus (NPH) of acquired and congenital/developmental aetiologies, patients with Alzheimer's disease and patients with Parkinson's disease in a Japanese analysis cohort. A corresponding iNPH group and NC group in a Finnish cohort was used for validation. Patients in the Finnish cohort who underwent biopsy were classified into two groups based on amyloid and/or tau deposition. We measured PTPRQ expression levels in autopsied brain specimens of iNPH patients and the NC group. RESULTS: Cerebrospinal fluid PTPRQ concentrations in the patients with NPH of idiopathic, acquired and congenital/developmental aetiologies were significantly higher than those in the NC group and those with Parkinson's disease, but iNPH showed no significant differences when compared with those in the Alzheimer's disease group. For the patients with iNPH, the area under the receiver-operating characteristic curve was 0.860 in the Japanese iNPH and 0.849 in the Finnish iNPH cohorts. Immunostaining and in situ hybridization revealed PTPRQ expression in the ependymal cells and choroid plexus. It is highly possible that the elevated PTPRQ levels in the CSF are related to ependymal dysfunction from ventricular expansion. CONCLUSIONS: Cerebrospinal fluid PTPRQ levels indicated the validity of this assay for auxiliary diagnosis of adult chronic hydrocephalus.
Assuntos
Doença de Alzheimer , Hidrocefalia de Pressão Normal , Adulto , Peptídeos beta-Amiloides , Biomarcadores , Humanos , Proteínas Tirosina Fosfatases , Proteínas Tirosina Fosfatases Classe 3 Semelhantes a ReceptoresRESUMO
The extracellular polysaccharides (EPS) produced by lactic acid bacteria (LAB) are associated with the rheology, texture, and mouthfeel of fermented milk products, including yogurt. This study investigated the immunomodulatory effects of EPS purified from the culture supernatant of Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) OLL1073R-1. The crude EPS were prepared from the culture supernatant of L. bulgaricus OLL1073R-1 by standard chromatographic methods, and were fractionated into neutral EPS and acidic EPS (APS). Acidic EPS were further fractionated into high molecular weight APS (H-APS) and low molecular weight APS (L-APS). High molecular weight APS were shown to be phosphopolysaccharides containing D-glucose, D-galactose, and phosphorus. Stimulation of mouse splenocytes by H-APS significantly increased interferon-gamma production, and, moreover, orally administered H-APS augmented natural killer cell activity. Oral administration of yogurt fermented with L. bulgaricus OLL1073R-1 and Streptococcus thermophilus OLS3059 to mice showed a similar level of immunomodulation as H-APS. However, these effects were not detected following administration of yogurt fermented with the starter combination of L. bulgaricus OLL1256 and S. thermophilus OLS3295. We conclude from these findings that yogurt fermented with L. bulgaricus OLL1073R-1, containing immunostimulative EPS, would have an immunomodulatory effect on the human body.
Assuntos
Fatores Imunológicos/farmacologia , Lactobacillus delbrueckii/metabolismo , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/farmacologia , Animais , Meios de Cultivo Condicionados , Fermentação , Galactose/análise , Glucose/análise , Interferon gama/biossíntese , Interleucina-4/biossíntese , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Peso Molecular , Fósforo/análise , Polissacarídeos Bacterianos/química , Baço/imunologia , Streptococcus thermophilus/metabolismo , Iogurte/microbiologiaRESUMO
The formalization of long-standing cooperative joint research efforts between Japanese and U.S. scientists has resulted in the development of specific areas of mutual program interest. The overall future objective of this program is to foster and encourage collaboration of mutual interest and benefit.
Assuntos
Neoplasias , Feminino , Humanos , Cooperação Internacional , Japão , Masculino , Pesquisa , Estados UnidosRESUMO
Recent studies have demonstrated that at the early stages of carcinogenesis of the large intestine(s) (LI), severely dilated crypt(s) (SDC) appear followed by atypical and/or neoplastic crypt(s) (ANC) and, subsequently, carcinomas. Thus both SDC and ANC appear to be premalignant changes and are probably initiated foci. Since the Japanese in Japan (JIJ) show a much lower rate of large intestinal carcinomas (LIC) compared to people in the Western Hemisphere, a study was designed to answer the question: Is the difference between the rates due to a difference in initiation or promotion? If the difference is due to less initiation, large intestinal epithelium of JIJ should contain fewer initiated foci. For testing this hypothesis, a retrospective histopathologic study was conducted on 100 LI of JIJ resected at the Cancer Institute, Tokyo, Japan, between 1977 and 1978, and mucosae remote from carcinomas were examined for SDC and ANC. In sharp contrast to a 100% incidence of SDC in the cases in the United States, only 1 of 100 LI of patients with LIC at the Cancer Institute demonstrated the presence of SDC. However, ANC was seen in 10 of 100 LI (10%), a figure comparable to that in the United States (7%). The extreme rarity of SDC in JIJ represents lesser initiation of that type. The presence of a comparable number of ANC in JIJ indicates that ANC is the predominant morphologic type of initiated foci in JIJ. This study suggests that not only promotional agents but also different initiating factors may be responsible for the difference in incidence and prevalence of LIC in the two populations. Comparative studies of parallel experimental animal models with the use of high and low doses of azoxymethane support this conclusion.
Assuntos
Neoplasias Intestinais/patologia , Intestino Grosso/patologia , Adolescente , Adulto , Fatores Etários , Idoso , Humanos , Mucosa Intestinal/patologia , Neoplasias Intestinais/epidemiologia , Japão , Pessoa de Meia-Idade , Estados UnidosRESUMO
Neurogenic tumors were found protruding from various parts of the body of 23 coho salmon. The tumor-bearing fish were first- or second-generation fish derived from eggs imported at the eyed stage to Japan from the United States. Twenty-two of the tumors were in young adults and varied from 14 to 80 mm in maximum diameter. Histologically, the tumors were composed of spindle-shaped cells with abundant fibrous stroma. One tumor showed typical nuclear palisading. All tumors in young adults invaded locally muscle and adipose tissues. These tumors were similar in histologic appearance to malignant schwannomas in humans. One tumor found in a fingerling coho salmon was identified as an ependymoblastoma. The Vectstain avidin-biotin-peroxidase complex immunoperoxidase staining procedure for S-100 protein revealed that the S-100 protein existed in an ependymoblastoma and in areas of typical nuclear palisading in a malignant schwannoma in coho salmon. The occurrence of soft tissue tumors in coho salmon was first recorded in Japan. The morphology and etiology of the present cases were compared with those of the tumors in salmon reported from the United States. Judging from the conditions in which the fish were reared, the development of these tumors was not related to halogenated compounds formed during water chlorination, as suggested previously. The environmental factor(s) responsible for their development has not yet been identified, and genetic influences may have been a contributory factor.
Assuntos
Doenças dos Peixes/patologia , Neoplasias de Tecido Nervoso/veterinária , Salmão , Animais , Feminino , Doenças dos Peixes/etiologia , Água Doce , Masculino , Microscopia Eletrônica , Neoplasias de Tecido Nervoso/patologia , Neoplasias de Tecido Nervoso/ultraestrutura , Neurilemoma/veterinária , Corantes de Rosanilina/toxicidadeRESUMO
Concentrations of estrogen receptor (ER) and alpha-fetoprotein were determined by dextran-coated charcoal assay and analyzed with Scatchard plots and radioimmunoassay, respectively, in cytosols of 72 human breast cancers. The values for ER ranged from 0 to 340 fmoles/mg cytosol protein. The concentrations of alpha-fetoprotein, which were low in all tumor cytosols examined, ranged from less than 0.1 to 1.1 ng/mg cytosol protein. No positive relationship was found between ER and alpha-fetoprotein concentrations. These results show that ER, but not alpha-fetoprotein, usually accounts for most of the high estrogen-binding capacity in cytosols of human breast cancers.
Assuntos
Neoplasias da Mama/análise , Receptores de Estrogênio/análise , alfa-Fetoproteínas/análise , Citosol/análise , Feminino , HumanosRESUMO
Liver tumors were observed in 2 South American lungfish (Lepidosiren paradoxa) and in 1 African lungfish (Protopterus amphibius) kept in 3 different aquariums in Japan for 2-5 years. In the first case a single, large nodule (70 X 60 X 55 mm) in the liver had been noted externally as a swelling 1 year prior to death. In the second case 2 rounded nodules (25 X 15 X 15 mm and 15 X 10 X 10 mm) were incidentally found at autopsy. In the third case, which also demonstrated abdominal swelling for 1 year preceding death, 2 green nodules (50 X 50 X 40 mm and 17 X 17 X 17 mm) were found in the liver together with multiple metastatic lesions. Histologically, variation was evident from tumor to tumor, even within the same animal. The most common histologic type was typical trabecular hepatomas. Admixtures of glandular or papillary structures were noted in some tumors. A region of poorly differentiated hepatocellular carcinoma with spindle-shaped cells in a sheetlike arrangement was noted in one case. The cause of these tumors is unknown. Since liver tumors were discovered at relatively high incidence (3/14 autopsied cases, including 6 species), lungfish seem to be predisposed to the development of liver tumors.
Assuntos
Carcinoma Hepatocelular/veterinária , Doenças dos Peixes/patologia , Neoplasias Hepáticas/veterinária , Animais , Autopsia , Antígeno Carcinoembrionário/análise , Carcinoma Hepatocelular/secundário , Feminino , Doenças dos Peixes/microbiologia , Peixes , Histocitoquímica , Japão , Masculino , Microscopia Eletrônica , alfa-Fetoproteínas/análiseRESUMO
Nephroblastomas were observed in 50 Japanese eel reared at a farm for 5 to 9 months from 1989 after collection in the wild. The tumors, arising from the trunk kidney near the anus, were noted externally as abdominal swellings and varied in size from 30 to 75 mm in maximum diameter. Most were elastic, solid, and well encapsulated. Histologically, the nephroblastomas were composed of combinations of three main tissue elements. Spindle- or oval-shaped cells resembling human blastema cells were observed in most tumors to some larger or smaller degree. Although variation was evident from tumor to tumor, and even within the same tumor, the most common histological type was epithelial with formation of alveolar nests, the cells sometimes being arranged in tubular structures simulating normal renal tubules. A muscle tissue element with distinct cross-striations was also observed. Liver metastases were found in one case. Histological examination of apparently normal kidneys from 100 eels revealed one early-stage nephroblastoma. The cause of these tumors is unclear, although they have been discovered with increasing incidence after the spread of indoor eel culture with raised water temperatures (26-27 degrees C) in Japan. Environmental factor(s) associated with the new aquaculture method may thus play a role in their genesis.
Assuntos
Anguilla , Neoplasias Renais/patologia , Neoplasias Renais/veterinária , Tumor de Wilms/patologia , Tumor de Wilms/veterinária , Animais , Japão , Microscopia EletrônicaRESUMO
The effect of 4-isopropylcatechol (4-IPC), a potent, irreversible cutaneous depigmenting agent, on protein biosynthesis of malignant melanoma cells in mice was studied by examining the in vitro amino acid (leucine) incorporation into a microsome fraction in cell sap. The present study revealed that 4-IPC does not inhibit the protein biosynthesis of the cell-free system in mouse liver, but remarkably inhibits it in mouse melanoma cells, which contain a high level of tyrosinase. The enhanced inhibition was found also in the mouse liver cell-free system when tyrosinase was added. Air oxidation products of 4-IPC were not responsible for such inhibition. These results may indicate that 4-IPC directly inhibits protein biosynthesis, probably by some intermediates that occur in an early stage of enzymatic oxidation of 4-IPC.
Assuntos
Catecol Oxidase/farmacologia , Catecóis/farmacologia , Melanoma/metabolismo , Animais , Sistema Livre de Células/efeitos dos fármacos , Células Cultivadas/efeitos dos fármacos , Técnicas In Vitro , Leucina/metabolismo , Masculino , Melanócitos/efeitos dos fármacos , Melanoma/enzimologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/metabolismo , Neoplasias Experimentais/enzimologia , Neoplasias Experimentais/metabolismo , Oxirredução , Biossíntese de ProteínasRESUMO
We have compared the incidence of estrogen receptor (ER) in breast tumors and its clinical correlation with responses to endocrine therapies in Japanese and American patients. There was no correlation between tumor histopathology and the presence of ER, and the ER values in primary and metastatic lesions from the same patients were similar in most Papanese cases. Japanese patients with low and high plasma estradiol levels had identical incidences of ER-positive tumors. The correlation between tumor ER and response to endocrine therapy is similar between Japanese and American patients. The incidence of ER-positive tumors is higher in postmenopausal American patients in both primary and metastatic lesions. It is possible that the reported increase in tumor lymphocyte infiltration in Japanese patients may explain this difference. The reported 5-year survival advantage of Japanese breast cancer patients cannot be explained by differences between the two populations in the response to endocrine therapy for advanced disease.
Assuntos
Neoplasias da Mama/metabolismo , Receptores de Estrogênio/metabolismo , Sistema ABO de Grupos Sanguíneos , Adrenalectomia , Adulto , Idoso , Neoplasias da Mama/sangue , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Castração , Estradiol/sangue , Feminino , Hormônios Esteroides Gonadais/uso terapêutico , Humanos , Hipofisectomia , Japão , Menopausa , Pessoa de Meia-Idade , Metástase Neoplásica , Remissão Espontânea , Estados UnidosRESUMO
We examined loss of heterozygosity (LOH) on all autosomal chromosomes in 53 non-small cell lung carcinomas. Frequent LOH was observed on the long arms of chromosomes 1 (37%), 2 (31%), 5 (30%), 8 (31%), and 13 (32%), and the short arms of chromosomes 3 (54%) and 17 (62%). LOH on chromosomes 3p and 17p was observed in all informative cases of squamous cell carcinoma, but was significantly less frequent in adenocarcinomas (P = 0.003 and 0.001, respectively). Similarly, LOH on chromosome 13q was observed frequently in squamous cell carcinomas (5 of 9 informative cases, or 56%), but in only 5 of 26, or 19%, of adenocarcinomas. In contrast, LOH on chromosome 2q was observed only in adenocarcinomas. In addition, this chromosomal arm was lost more frequently in poorly differentiated, compared to well differentiated adenocarcinomas. Furthermore, a correlation between fractional allelic loss and pathohistological grade was identified. These results implicate the presence of several tumor suppressor genes associated with development and/or progression of non-small cell lung carcinomas.
Assuntos
Adenocarcinoma/genética , Alelos , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma de Células Escamosas/genética , Heterozigoto , Neoplasias Pulmonares/genética , Southern Blotting , HumanosRESUMO
To investigate the mechanisms underlying respiratory tract carcinogenesis in chromate workers, we measured the concentration of chromium in samples of tissues from 50 bronchial bifurcations and other bronchial tissue obtained at autopsy, or during surgical procedures, from 9 exchromate workers known to be at risk of developing lung cancer. The mean duration of exposure was 21 years and the average time between cessation of exposure and death/surgery was 15 years. The area of the tissue samples was measured by image analysis and the chromium concentration determined by neutron activation analysis. Chromium concentrations ranged from 0.04 to 39 x 10(-10) g/microns tissue thickness/mm2 and in 80% of the cases the concentrations were greater at bifurcations than in neighboring epithelial tissue. The mean concentration ratios between bifurcations and adjacent areas were 1.5 (n = 1) in the trachea, 3.0 (n = 9) in the main bronchi, 3.6 (n = 22) in lobar bronchi, and 10.9 (n = 3) in subsegmental bronchi. Our results demonstrated long-term retention of chromium in the bronchial walls of chromate workers and also that chromium concentrations were higher at airway bifurcations than elsewhere, thus providing solid evidence for a deposition "hot spot" concept.
Assuntos
Brônquios/química , Cromo/análise , Exposição Ocupacional , Idoso , Brônquios/patologia , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
In 1979, 2 species of pond frogs (Rana nigromaculata and Rana plancyi plancyi) were imported from China, and hybrids were made between these and Japanese, Korean, and Taiwanese pond frogs (R. nigromaculata, Rana plancyi fukienensis and Rana brevipoda) that had been kept for a number of years in the Laboratory for Amphibian Biology of Hiroshima University. From 1982, development of tumors, especially in the peritoneal cavity, was noticed frequently in the hybrids and also later, although rarely, in the Japanese pond frogs. Such tumors had never previously been observed among pond frogs in the laboratory. Histological and immunohistochemical studies identified the i.p. tumors to be pancreatic carcinomas with occasional production of insulin and/or somatostatin. Ultrastructural investigation revealed both endocrine and exocrine secretion granules together with C-type retrovirus particles in the carcinoma cells. Other tumors included a retroperitoneal rhabdomyosarcoma, liver adenomas, and an unclassifiable mesenchymal tumor of the foot pad.
Assuntos
Carcinoma/veterinária , Neoplasias Pancreáticas/veterinária , Ranidae , Animais , Animais de Laboratório , Carcinoma/patologia , Quimera , Humanos , Microscopia Eletrônica , Neoplasias Pancreáticas/patologiaRESUMO
In order to scrutinize the possible significance of (nonatypical) mucous cell hyperplasia of the pancreas to neoplasia, we analyzed these lesions in terms of c-Ki-ras activation, which is known to be very frequent in pancreatic carcinomas. A total of 16 such mucous cell hyperplasias were collected from 10 pancreases resected for chronic pancreatitis. Tiny tissue fragments were taken from hematoxylin-stained sections by microdissection, and DNA analysis was carried out by the polymerase chain reaction amplification and oligonucleotide hybridization methods. Activating mutations of c-Ki-ras oncogene at codon 12 were detected in 10 of the 16 lesions (62.5%), a high rate as seen in carcinomas. The results indicated a clonal origin of cells comprising the mucous cell hyperplasia suggesting a neoplastic and/or precancerous nature.
Assuntos
Regulação da Expressão Gênica , Genes ras , Pâncreas/patologia , Pancreatite/genética , Adulto , Idoso , Sequência de Bases , Doença Crônica , Feminino , Humanos , Hiperplasia , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Pâncreas/metabolismo , Pancreatite/patologia , Mutação PuntualRESUMO
The cyclododecapeptide, (Ala1-Pro2-Gly3-Val4-Gly5-Val6)2, was synthesized and its secondary structure was evaluated from extensive studies in dimethyl sulphoxide, trifluoroethanol and water using NMR methods. A selective decoupling technique in 13C-NMR has been utilized in order to assign the C=O carbon resonances. Temperature dependence of the peptide NH protons and the solvent perturbation of the peptide NH and C=O resonances show the occurrence in all solvents of a beta-turn (a 10-membered H-bond between the Val4 NH and Ala1 C=O) and a gamma-turn, an 11-membered H-bond between the Gly3 NH and the Gly5 C=O; and a possible 14-membered H-bond between the Ala1 NH and the Val4 C=O in dimethyl sulphoxide and trifluoroethanol. These secondary structural features are compared with the linear polyhexapeptide and found the the beta-turn and the gamma-turn are the common conformational features of these peptide systems.
Assuntos
Elastina , Peptídeos Cíclicos , Tropoelastina , Sequência de Aminoácidos , Fenômenos Químicos , Química , Elastina/análogos & derivados , Espectroscopia de Ressonância Magnética , Fragmentos de Peptídeos , Peptídeos Cíclicos/síntese químicaRESUMO
Heat shock protein 90 was purified from calf uterus and rat liver. Both heat shock protein 90s had similar molecular weights, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, of Mr 87,000 and 88,000, isoelectric points of 5.2, and Stokes radii of 6.7 and 6.5 nm, respectively. Heat shock protein 90 bound to phenyl-Sepharose CL-4B even at low ionic strength, and also bound to butyl-Toyopearl at high ionic strength. Heat shock protein 90 bound to phenyl-Sepharose could be eluted with a buffer containing organic solvents or detergents such as 2-propanol, dioxane, dimethylformamide, methyl cellosolve, 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate or Triton X-100, but not with ionic salts such as 1 M KCl. These results suggest that heat shock protein 90 possesses a significant hydrophobic region on the surface of the molecule. Hydrophobicities of heat shock protein 90 and 4S calf uterine estrogen receptor were both decreased by formation of a 8 S estrogen receptor complex. The role of the hydrophobic region of heat shock protein 90 in the interaction with estrogen receptor and other proteins is discussed.
Assuntos
Proteínas de Choque Térmico/isolamento & purificação , Fígado/metabolismo , Útero/metabolismo , Animais , Bovinos , Cromatografia em Gel , Eletroforese em Gel Bidimensional , Feminino , Conformação Proteica , Ratos , Ratos Endogâmicos , Receptores de Estrogênio/análiseRESUMO
BACKGROUND: Ciliated cells in gastrectomies from patients dwelling in the Pacific and Atlantic basins have been reported previously. AIM: To compare all the results in an attempt to explain the findings. METHODS: Sections from 3406 gastrectomies were reviewed: 1966 and 1440 from the Atlantic and Pacific basins, respectively. Ciliated cells and intestinal metaplasia (IM) were recorded; IM was classified into focal or extensive IM. The total number of sections/gastrectomy was noted. RESULTS: In the Atlantic basin, 5% of specimens had ciliated metaplasia (CM); it was more frequent in intestinal carcinoma (IC; 9%) than diffuse carcinoma (DC; 3%) or miscellaneous gastric diseases (MGD; 3%). In the Pacific basin, the frequency of specimens with CM was 29%: it was more frequent in IC (43%) than in DC (16%) or MGD (10%). The difference between the frequency of CM in specimens with IC or with DC/MGD in the Atlantic and the Pacific basins was significant (p < or = 0.05). The presence of CM was influenced by age and the extent of IM in both basins, but not by sex or the number of sections investigated. CONCLUSIONS: CM-apparently an independent microscopic marker-was significantly higher in the Pacific than in the Atlantic basin. Environmental carcinogens involved in the evolution of IM and IC seem to be implicated in gastric ciliogenesis. Carcinogens that differ in nature and/or in strength in both basins might activate the latent natural genes encoding ciliated processes in gastric cells in patients subsequently developing gastric carcinoma, more notably of intestinal type.
Assuntos
Cílios/patologia , Lesões Pré-Cancerosas/etnologia , Gastropatias/etnologia , Estômago/patologia , Adulto , Fatores Etários , Idoso , América/epidemiologia , Europa (Continente)/epidemiologia , Feminino , Gastrectomia , Mucosa Gástrica/patologia , Humanos , Masculino , Metaplasia/etnologia , Metaplasia/patologia , Pessoa de Meia-Idade , Ilhas do Pacífico/epidemiologia , Lesões Pré-Cancerosas/patologia , Antro Pilórico/patologia , Fatores Sexuais , Gastropatias/patologia , Neoplasias Gástricas/etnologia , Neoplasias Gástricas/patologiaRESUMO
The three basic pigment cell types found in poikilothermic vertebrates, melanocytes (melanin-producing cells), erythrophores (red or yellow pigment cells), and iridophores (iridescence-producing cells), are derived from neural crest. Neoplasms of pigment cells in fish are also of three phenotypes, melanomas (melanophoromas), erythrophoromas, and iridophoromas, showing the phenotypes of their corresponding normal pigment cells. These pigment cell tumors are among the most common types in bony fish and seem to be more common in fish than in mammals, including humans. Moreover, there are no mammalian neoplasms corresponding to erythrophoromas and iridophoromas in fish. The complexities in the nature and classification of pigment cell tumors in fish will be discussed on the basis of a survey of our collection of these tumors at the Cancer Institute. The etiology of pigment cell tumors in fish is obscure. In order to know whether activated oncogene is involved in the genesis of erythrophoromas in goldfish, the ras genes from normal and erythrophoroma cells were cloned and their nucleotide sequences were compared. The goldfish ras gene and human ras genes showed striking homology. However, no point mutation at the 12th codon was observed in ras genes isolated from erythrophoromas. Besides pigment cell tumors in fish, abnormal pigmentation or depigmentation in flounders associated with diseased conditions is also described.
Assuntos
Cromatóforos/patologia , Peixes/fisiologia , Melanoma/patologia , Neoplasias Cutâneas/patologia , Animais , Cromatóforos/ultraestrutura , Melanoma/etiologia , Melanoma/ultraestrutura , Microscopia Eletrônica , Neoplasias Cutâneas/etiologia , Neoplasias Cutâneas/ultraestruturaRESUMO
The p34 protein is a non-glycosylated, integral membrane protein characteristic of rough microsomes and is believed to play a role in the ribosome-membrane association. Here, antibodies directed against p34 were examined as to their inhibitory effect on ribosome binding to and protein translocation across the microsomal membrane. Preincubation of the stripped (ribosome-depleted) membrane with anti-p34 immunoglobulins (IgGs) or their Fab fragments led to more than 80% inhibition of the binding of ribosomes and their large (60S) subunit to the membrane. The inhibition was dependent on the amount of antibodies used, but comparable amounts of IgGs and Fab fragments from nonimmune serum had less effect. The p34 antibodies were also inhibitory for cotranslational translocation of secretory proteins, i.e. placental lactogen and serum albumin, across the membrane. These results suggest that p34 is involved in the binding of ribosomes to the microsomal membrane and that it is in close proximity to the protein translocation site in the microsomal membrane.
Assuntos
Anticorpos , Membranas Intracelulares/metabolismo , Proteínas de Membrana/imunologia , Microssomos/ultraestrutura , Ribossomos/metabolismo , Animais , Sítios de Ligação , Transporte Biológico , Fragmentos Fab das Imunoglobulinas , Imunoglobulina G , Lactogênio Placentário/metabolismo , Ratos , Albumina Sérica/metabolismoRESUMO
As a first step in the investigation of the reconstitution of steroid hormone receptor systems, we studied the reconstitution of 9 S estrogen receptor (ER) from purified vero ER, which is the estradiol binding subunit, and heat shock protein 90 (hsp 90). By using a phosphate buffer containing molybdate, thiocyanate, dimethylformamide, glycerol, etc., vero ER could be converted to 9 S ER with hsp 90, but not with the control protein, ovalbumin. Inactivation of ER during the reconstitution was suppressed partially by hsp 90, but not by ovalbumin. Like native 8 S ER, the reconstituted ER was sedimented at about 8.9 S and 4.6 S on glycerol gradient centrifugation in low and high salt buffers, respectively.