RESUMEN
Ozone generators have attracted attention as a result of the spread of severe acute respiratory syndrome coronavirus-2. In a questionnaire survey targeting healthcare facilities, 20 (91%) used ozone generators in patient areas, and five (23%) used them in indoor spaces occupied by people. A search for ozone generators on the Amazon Japan website revealed that 76% of products lacked information on ozone emission rate, coverage area and/or use time. These results suggest that ozone generators may be used inappropriately in hospitals and clinics, and have been sold to the general public without adequate information for assessing their safety and efficacy.
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Contaminación del Aire Interior , COVID-19 , Ozono , Contaminación del Aire Interior/análisis , Personal de Salud , Humanos , SARS-CoV-2 , Encuestas y CuestionariosRESUMEN
Although angiogenesis plays a crucial role in cancer growth and progression, no reliable method for assessing angiogenesis in tumor tissue sections currently is available. Using biomarkers with high specificity for proliferating endothelial cells could help quantify angiogenic activity. Thymidine kinase-1 (TK1) is an enzyme involved in the salvage pathway of DNA synthesis and its activity is correlated with cell proliferation. We investigated the use of double immunostaining for TK1 and CD31 for identifying activated tumor vessels. Differences in TK1/CD31 positive vessel rates (PVRs) between tumor and adjacent normal tissues were evaluated in 39 colorectal carcinoma (CRC) samples and compared with those of Ki67/CD31 double stained tissues. Mean TK1/CD31 PVR (23.6%) in CRCs was 13.9 fold greater than in adjacent normal tissues (1.7%)). By comparison, mean Ki67/CD31 PVR in CRCs was 20.0%, i.e. only 4.8 fold greater than in normal tissues (4.2%). Also, mean TK1/CD31 PVR in normal tissues was significantly less than mean Ki67/CD31 PVR. Our findings indicate that double immunostaining for TK1/CD31 can detect activated tumor vessels more accurately than staining for Ki67/CD31 and potentially could identify tumors that will respond to anti-angiogenic therapy.
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Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Timidina Quinasa/metabolismo , Biomarcadores de Tumor , Proliferación Celular , Neoplasias Colorrectales/enzimología , Neoplasias Colorrectales/metabolismo , Regulación Enzimológica de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/genética , Timidina Quinasa/genéticaRESUMEN
INTRODUCTION: Positive peritoneal cytology (PPC) in endometrial cancer remains a controversial topic. Cleaved caspase-3 (CC3) and Ki-67 are excellent markers of apoptotic and proliferating cells, respectively. The objective of this study was to determine the significance of CC3 and Ki-67 expression in peritoneal cytology samples as prognostic factors for endometrial cancer with PPC. METHODS: Sixty endometrial cancer specimens with PPC alone were divided into 51 endometrioid tumours (43 endometrioid carcinomas and eight carcinomas with squamous differentiation) and nine non-endometrioid tumours (two serous carcinomas, three clear cell carcinomas and four carcinosarcomas). CC3 and Ki-67 expression in peritoneal cytology samples were immunocytochemically assessed and correlated with disease-free survival (DFS) and overall survival (OS). RESULTS: Expression levels of CC3 and Ki-67 were not associated with any clinicopathological parameter. Patients with non-endometrioid tumours had significantly shorter DFS (P = .001) and OS (P = .001). Low CC3 expression (CC3Low ) was significantly associated with shorter OS (P = .02), but not DFS (P = .13). Multivariate analysis showed that non-endometrioid histology and CC3Low were independent prognostic factors. However, Ki-67 expression was not associated with survival. When endometrioid and non-endometrioid tumours were assessed separately, CC3Low was significantly associated with shorter DFS (P = .002) and OS (P = .002) in patients with non-endometrioid tumours. CONCLUSIONS: Our results suggest that CC3Low in peritoneal cytology samples is a poor prognostic factor in patients with endometrial cancers, especially non-endometrioid tumours. Immunocytochemical analysis of CC3 expression could potentially facilitate identification of patients with high-risk endometrial cancer with PPC.
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Caspasa 3/metabolismo , Neoplasias Endometriales/metabolismo , Peritoneo/metabolismo , Adenocarcinoma de Células Claras/metabolismo , Adenocarcinoma de Células Claras/patología , Apoptosis/fisiología , Carcinoma Endometrioide/metabolismo , Carcinoma Endometrioide/patología , Proliferación Celular/fisiología , Supervivencia sin Enfermedad , Neoplasias Endometriales/patología , Femenino , Humanos , Antígeno Ki-67/metabolismo , Persona de Mediana Edad , Peritoneo/patología , Pronóstico , Estudios Retrospectivos , Factores de RiesgoRESUMEN
High expression of thymidylate synthase (TS) and inactivation of p53 are allegedly associated with chemoresistance. The authors evaluated TS and p53 expression in gastric cancer treated with neoadjuvant S-1/cisplatin chemotherapy. Paraffin sections of pretreatment biopsy and surgical specimens from 41 gastric cancers were immunostained for TS and p53 protein after appropriate antigen retrieval. Fifty-one cases without neoadjuvant chemotherapy were also studied. In the pretreatment biopsies, high expression of TS was seen in 8% of the histologic responders, in 28% of the nonresponders and in 31% of the controls. High expression of p53 was observed in 56% of the nonresponders, but in 8% of the responders and in 29% of the controls (P<0.01 and P<0.05, respectively). The TS- and/or p53-high phenotype was seen in 76% of the nonresponders and in 54% of the controls, but in 8% of the responders (P<0.0001 and P<0.005, respectively). The data of the surgical specimens were consistent with those of the pretreatment biopsies. These results suggest that immunostaining for TS and p53 protein is useful for pretreatment selection of gastric cancer patients unresponsive to S-1/cisplatin chemotherapy.
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Antineoplásicos/uso terapéutico , Cisplatino/uso terapéutico , Neoplasias Gástricas/tratamiento farmacológico , Proteína p53 Supresora de Tumor/metabolismo , Resistencia a Antineoplásicos , Femenino , Humanos , Inmunohistoquímica , Masculino , Persona de Mediana Edad , Neoplasias Gástricas/enzimología , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/cirugía , Timidilato Sintasa/metabolismoRESUMEN
AIM: The acromegaly patient was diagnosed with Type 2 diabetes mellitus. His HbA1c was 10.6% and fasting blood glucose (FBG) 15.3 mmol/l. We prescribed glibenclamide (10 mg/day), but his HbA1c and FBG remained high. At this stage, treatment with short-acting insulin was instigated at a dose of 20 U/day. However, the patient's blood glucose level remained unsatisfactory. We tried using pioglitazone. METHOD: Pioglitazone was prescribed at 30 mg/day in combination with the insulin. RESULTS: The FBG and HbA1c value decreased to 7.2 mmol/l and 7.3%, respectively, within 2 months and insulin was discontinued. Pioglitazone alone was able to control the FBG level. CONCLUSIONS: Pioglitazone treatment might be considered as a choice for similar cases of diabetes secondary to acromegaly.
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Acromegalia/complicaciones , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Hipoglucemiantes/uso terapéutico , Tiazolidinedionas/uso terapéutico , Glucemia/análisis , Diabetes Mellitus Tipo 2/etiología , Quimioterapia Combinada , Humanos , Insulina/uso terapéutico , Masculino , Persona de Mediana Edad , Pioglitazona , Resultado del TratamientoRESUMEN
The immunohistochemical expression of type 1 blood group antigens (type 1 BGAs) was analyzed for 30 cases of testicular germ cell tumors (TGCTs), using monoclonal antibodies against DU-PAN-2, CA19-9, Lewis(a) (Le(a)), and Lewis(b) (Le(b)). DU-PAN-2 was expressed very frequently in all of the embryonal carcinomas (ECs). CA19-9 expression was demonstrated in 53% of ECs, but the number of positive cells was generally smaller than that for DU-PAN-2. CA19-9-negative ECs tended to show a higher number of DU-PAN-2-positive cells compared to CA19-9-positive ECs, and ECs in which DU-PAN-2 was more strongly expressed showed a relatively frequent expression of CA19-9. In 36% of seminomas and 56% of yolk sac tumors (YSTs), DU-PAN-2 was weakly expressed, and the positive cells were few in number. Little or no expression of CA19-9 was demonstrated in seminomas and YSTs. Regarding Le(a) and Le(b), the expressions were found to be limited to teratomas at a frequency of 57% and 86%, respectively, with the exception of one EC positive for Lea and one YST positive for Leb. Eighty-six percent of teratomas showed expressions of DU-PAN-2 and CA19-9. DU-PAN-2 was also seen in some intratubular malignant germ cells. The antibodies used were all negative for choriocarcinomas, syncytiotrophoblastic giant cells, and normal testicular tissues. The antigen expressions were predominantly observed on the surface of tumor cells developing luminal structures. In conclusion, although CA19-9 was relatively specific for ECs, it should be emphasized that ECs were rather characteristic of extensive DU-PAN-2 expression. Particularly in CA19-9-negative ECs, a combined analysis of DU-PAN-2 and CA19-9 would be helpful in confirming the histopathologic diagnosis of TGCTs. The clinical significance of DU-PAN-2 in ECs as a tumor marker remains to be clarified. Le(a) and Le(b) expressions were thought to be related to the differentiation or maturation rather than to the malignant transformation in TGCTs.
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Antígenos de Neoplasias/metabolismo , Biomarcadores de Tumor/metabolismo , Neoplasias de Células Germinales y Embrionarias/metabolismo , Neoplasias Testiculares/metabolismo , Adolescente , Adulto , Anticuerpos Monoclonales , Antígeno CA-19-9/metabolismo , Antígeno Carcinoembrionario/metabolismo , Carcinoma Embrionario/inmunología , Carcinoma Embrionario/metabolismo , Carcinoma Embrionario/patología , Niño , Preescolar , Tumor del Seno Endodérmico/inmunología , Tumor del Seno Endodérmico/metabolismo , Tumor del Seno Endodérmico/patología , Femenino , Humanos , Técnicas para Inmunoenzimas , Lactante , Recién Nacido , Antígenos del Grupo Sanguíneo de Lewis/metabolismo , Masculino , Persona de Mediana Edad , Neoplasias de Células Germinales y Embrionarias/inmunología , Neoplasias de Células Germinales y Embrionarias/patología , Orquiectomía , Seminoma/inmunología , Seminoma/metabolismo , Seminoma/patología , Neoplasias Testiculares/inmunología , Neoplasias Testiculares/patologíaRESUMEN
Immunohistochemical expressions of type 1 blood group antigens were studied for 95 cases of thyroid tumors, including 29 follicular adenomas, 23 follicular carcinomas, and 43 papillary carcinomas, applying monoclonal antibodies against DU-PAN-2, CA19-9, Lewis(a) (Le(a)), and Lewis(b) (Le(b)). Normal thyroid tissue invariably failed to express all four antigens. In follicular adenomas, DU-PAN-2 and CA19-9 were focally expressed in 7% and 21% of cases, and in follicular carcinomas, CA19-9 expression was limited to one case (4%); all cases were negative for DU-PAN-2. No or little expression of Le(a) or Le(b) was observed in these follicular tumors. In contrast, DU-PAN-2, CA19-9, Le(a), and Le(b) were expressed in 98%, 84%, 33%, and 49% of 43 papillary carcinomas, respectively. The positive stainings were observed mainly on the luminal surface of the tumor cells. The number of tumor cells that expressed DU-PAN-2 generally was greater than that of tumor cells that expressed CA19-9, Le(a), or Le(b). There was no significant difference in antigen expressions in female papillary carcinomas between subjects who were younger and older than 50 years old. The results suggest that DU-PAN-2 would be a useful immunohistochemical marker for distinguishing papillary carcinomas from follicular tumors. These immunohistochemical profiles imply the following: the activity of alpha2-3 sialyltransferase, a specific glycosyltransferase, would be more strongly enhanced in papillary carcinomas than in follicular tumors; the antigen expressions in papillary carcinomas may not be related to the alteration of the female sex hormone environment.
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Antígenos de Neoplasias/biosíntesis , Biomarcadores de Tumor/metabolismo , Antígeno CA-19-9/biosíntesis , Carcinoma Papilar/metabolismo , Neoplasias de la Tiroides/metabolismo , Adenocarcinoma Folicular/metabolismo , Adenocarcinoma Folicular/patología , Adenoma/metabolismo , Adenoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma Papilar/patología , Femenino , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de la Tiroides/patología , Tiroiditis Autoinmune/metabolismo , Tiroiditis Autoinmune/patologíaRESUMEN
Immunoreactivity of prostate-specific antigen (PSA), a kallikrein-like enzyme present in the seminal plasma, was demonstrated by indirect immunoperoxidase staining using a PSA antiserum in the apical cytoplasm along the luminal border of small-sized duct epithelial cells of the major salivary (parotid and submandibular) gland of both sexes (56/56, 100%). No PSA-like immunoreactivity was seen in large-sized duct epithelial cells and acinar cells. Minor salivary gland ducts were negative. When inflammatory and atrophic changes were observed, ductal expression of PSA-like immunoreactivity was decreased (12/37, 32%) and the site of intracellular localization often became diffusely cytoplasmic. The immunoreactivity was absorbed by human seminal plasma. Immunoreactivities of prostatic acid phosphatase and sex hormone receptors were undetectable in the salivary gland. Twenty-nine (34%) of 86 salivary gland tumors with ductal differentiation were immunoreactive for PSA mainly in the cytoplasm. A PSA monoclonal antibody ER-PR8 detected immunoreactivity in the prostate but not in the salivary glands or their tumors. Prostate-specific antigen-like immunoreactivity in small-sized (intercalated) duct epithelial cells of the major salivary gland and their tumors may be due to cross-reactivity of the antiserum with kallikrein-like substances.
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Antígeno Prostático Específico/análisis , Neoplasias de las Glándulas Salivales/química , Glándulas Salivales Menores/química , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Anticuerpos Monoclonales/análisis , Células Epiteliales/química , Células Epiteliales/patología , Femenino , Humanos , Técnicas para Inmunoenzimas , Masculino , Persona de Mediana Edad , Conejos , Conductos Salivales/química , Conductos Salivales/patología , Neoplasias de las Glándulas Salivales/patología , Glándulas Salivales Menores/patologíaRESUMEN
Enterochromaffin-like (ECL) cells are included in the endocrine cells present in the gastric oxyntic mucosa, and have been attracting attention as histamine-secreting cells contributing to gastric secretion. However, the anatomical location of ECL cells in relation to parietal cells and chief cells has not yet been sufficiently investigated. To elucidate this location of ECL cells, we performed an immunocytochemical study using anti-histamine antibody and electron microscopic examination of guinea pig gastric mucosa. ECL cells were located near the basement membranes in the gastric oxyntic region, and were in contact with both chief cells and parietal cells in the same glandular epithelium. The ratio of ECL cells in contact with chief cells was clearly greater than that in contact with parietal cells. An omega-shaped morphology, indicating emiocytosis, was found in ECL cells by electron microscopy. These findings suggest that ECL cells have a paracrine effect on chief cells and parietal cells, and may have an important physiological role in pepsinogen secretion.
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Células Principales Gástricas/ultraestructura , Células Similares a las Enterocromafines/ultraestructura , Mucosa Gástrica/citología , Células Parietales Gástricas/ultraestructura , Animales , Células Cultivadas , Células Principales Gástricas/citología , Células Similares a las Enterocromafines/citología , Células Similares a las Enterocromafines/fisiología , Mucosa Gástrica/anatomía & histología , Cobayas , Inmunohistoquímica , Masculino , Microscopía Electrónica , Células Parietales Gástricas/citología , Sensibilidad y EspecificidadRESUMEN
Previous studies have suggested that heat shock proteins (HSP) of Helicobacter pylori (H. pylori) are involved in the induction of autoimmunity mediated gastritis. In the present report, the cross-reactivity between H. pylori-related HSP60 and gastric epithelial cells was investigated by the indirect immunoperoxidase method using two monoclonal antibodies (mAb) against H. pylori-derived HSP60, H9 and H20. H9 is reactive with an epitope common to bacterial HSP60, while H20 is specific to H. pylori HSP60. A total of 70 paraffin-embedded gastric biopsy specimens were analyzed after heat-induced epitope retrieval. Both mAb were cross-reactive with the gastric epithelial cells, with a higher frequency seen for the H9-reactive epitope. The frequency of positive epithelial decoration was not significantly different between H. pylori-positive and H. pylori-negative gastric mucosae. A variety of epithelial and non-epithelial cells were immunostained with mAb H9, while mAb H20 was cross-reactive only with small intestinal epithelia. Reactivity was mainly located in the Golgi area and rarely in the cytoplasm. These results suggest a noteworthy pitfall in immunohistochemical interpretations of HSP60-associated autoimmune reactions in the gastric mucosa.
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Chaperonina 60/análisis , Mucosa Gástrica/microbiología , Infecciones por Helicobacter/inmunología , Anticuerpos Antibacterianos/inmunología , Anticuerpos Monoclonales/análisis , Anticuerpos Monoclonales/inmunología , Especificidad de Anticuerpos , Autoinmunidad , Chaperonina 60/inmunología , Mucosa Gástrica/inmunología , Gastritis/inmunología , Gastritis/microbiología , Infecciones por Helicobacter/microbiología , Helicobacter pylori/inmunología , Humanos , Inmunohistoquímica , Reproducibilidad de los ResultadosRESUMEN
Normal and malignant plasma cells (PC), follicular dendritic cells (FDC), myofibroblasts (MFB) and perineurial cells (PNC) were investigated for the expression of MUC-1 glycoprotein (MUC-1gp) by immunohistochemical and immunoelectron microscopic techniques using monoclonal antibodies E29, 115D8, DF3 and a combination of the three. MUC-1 glycoprotein-positive PC detected by the combined antibodies were frequently seen in a variety of pathological lesions tested, including chronic cervicitis, chronic synovitis, Hodgkin's disease, allergic rhinitis and sinusitis, tuberculous lymphadenitis, foreign body granuloma, multiple myeloma, and chronic tonsillitis. In the lesions containing MUC-1gp-positive PC, the infiltration of immunoglobulin (Ig) E PC and/or IgE-bound mast cells was significantly increased, but MUC-1gp-positive PC did not contain any specific immunoglobulin heavy or light chains. The findings suggest that the expression of MUC-1 gp in PC, although not restricted to IgE-class cells, may be induced in an allergic status. Plasma cells and PNC mainly reacted with the antibodies E29 and 115D8, while FDC and MFB were principally reactive with the antibody DF3. In some cases of multiple myeloma, the neoplastic PC were predominantly immunoreactive with DF3. The results indicate: (i) the epitopic variability of MUC-1gp molecules expressed on the non-epithelial cells; and (ii) the epitopic alterations during malignant transformation. It should also be noted that the expression of MUC-1gp in the non-epithelial cells represents a pitfall in histopathological diagnosis.
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Células Dendríticas/metabolismo , Fibroblastos/metabolismo , Mucina-1/metabolismo , Nervios Periféricos/metabolismo , Células Plasmáticas/metabolismo , Anticuerpos Monoclonales , Células Dendríticas/patología , Fibroblastos/patología , Humanos , Técnicas para Inmunoenzimas , Microscopía Inmunoelectrónica , Mucina-1/inmunología , Neoplasias/metabolismo , Nervios Periféricos/patología , Células Plasmáticas/ultraestructuraRESUMEN
Hemangiopericytoma is a rare tumor originating from pericytes. In May 1988, a 33-year-old man was found to have a well-defined nodular shadow in the right upper lobe during a routine chest X-ray examination. Although the mass had been thought to be benign, in December 1992 it was found to have grown. In May 1993, the patient was referred to our hospital for further examination. A chest X-ray film and a high-resolution CT scan revealed a well-defined nodule in the right upper lung field without vascular gathering or pleural puckering. The tumor was slightly less dense than was soft tissues. There was no evidence suggesting another primary tumor or metastasis. In July 1993, because the mass was suspected to be a low-grade malignant tumor, a segementectomy (rt-S2) was done. On the basis of histologic, immunohistochemical and electronmicroscopic findings, pulmonary hemangiopericytoma was diagnosed. The postoperative course was uneventful. The patient has been well for 2 years and five months after the operation, with no sign of recurrence or metastasis.
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Hemangiopericitoma/diagnóstico por imagen , Neoplasias Pulmonares/diagnóstico por imagen , Radiografías Pulmonares Masivas , Adulto , Hemangiopericitoma/patología , Humanos , Neoplasias Pulmonares/patología , MasculinoRESUMEN
Immunoreactivities of prostatic acid phosphatase (PACP) and prostate-specific antigen (PSA) were demonstrated in normal anal glands of males (11 of 25) and urethral glands of both sexes (six of six), by indirect immunoperoxidase staining. These prostatic antigens were colocalized in nonmucous epithelial cells. In the anal gland, PACP and PSA were distributed exclusively in acinus-forming, tall columnar cells, while columnar cells with brush borders, goblet cells, and transitional cells in the duct were negative. The anal glands from 20 females were devoid of such acinar structures and were negative for the antigens. Normal urinary bladder mucosa (n = 17) lacked immunoreactivity. A few endocrine-type cells, which showed PACP immunoreactivity but no PSA staining, were identified in normal rectal mucosa (n = 17) and were found rarely in the anal gland. The results of the present study suggest (1) that the development of acinar cells in the anal gland is an androgen-dependent phenomenon, and (2) that the ability to express PACP and PSA is a feature common to cloacogenic glandular epithelium.
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Fosfatasa Ácida/análisis , Antígenos de Neoplasias/análisis , Sistema Urogenital/química , Adulto , Anciano , Anciano de 80 o más Años , Epitelio/química , Femenino , Humanos , Masculino , Persona de Mediana Edad , Próstata/enzimología , Antígeno Prostático EspecíficoRESUMEN
Helodermin-like and salmon calcitonin (sCT)-like immunoreactivities co-existed in a subset of human calcitonin (hCT)-containing cells in normal human thyroid tissue and medullary thyroid carcinomas. Helodermin/sCT-immunoreactive cells were mostly different from calcitonin gene-related peptide (CGRP)-positive cells. Helodermin and sCT immunoreactivities were not identified in pulmonary and pancreatic hCT-positive neuroendocrine tumors, except for a few lung tumor cells showing positive staining with one of two sCT antisera used. Helodermin immunoreactivity demonstrated by rabbit antiserum R0086 was completely abolished in the presence of synthetic sCT, while sCT immunoreactivity was not absorbed by synthetic helodermin. The carboxyl terminal Arg30-Thr31 sequence (and Pro35 amide structure) of helodermin would be the epitopic site recognized by this antiserum, since a similar amino acid sequence is present in sCT molecules but absent from hCT and CGRP.
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Calcitonina/metabolismo , Péptidos/metabolismo , Glándula Tiroides/metabolismo , Secuencia de Aminoácidos , Calcitonina/genética , Péptido Relacionado con Gen de Calcitonina/genética , Péptido Relacionado con Gen de Calcitonina/metabolismo , Células Cultivadas , Humanos , Inmunohistoquímica , Péptidos y Proteínas de Señalización Intercelular , Datos de Secuencia Molecular , Péptidos/genética , Homología de Secuencia de Ácido Nucleico , Glándula Tiroides/citología , Neoplasias de la Tiroides/metabolismo , Células Tumorales Cultivadas , Ponzoñas/metabolismoRESUMEN
Carcinoembryonic antigen (CEA) and nonspecific cross-reacting antigen (NCA) were studied immunohistochemically in formalin-fixed, paraffin-embedded tissues of 73 cases of medullary carcinoma of the thyroid (MTC) using 2 polyclonal antibodies (CEA antisera cross-reactive with or without NCA), 3 monoclonal antibodies recognizing epitopes only on CEA, and one monoclonal antibody against NCA. The staining patterns of the 5 antibodies against CEA in MTCs were not different, and they reacted with 86.3% of all cases. With regard to the effects of fixatives on the staining patterns, samples fixed with formalin or 4% paraformaldehyde demonstrated CEA immunoreactivity in both the cell membrane and cytoplasm. In Bouin-fixed tissue, the immunoreactivity was predominant on the cell membrane, whereas cytoplasmic positivity predominated in alcohol-fixed specimens. Thus the difference in fixatives used in previous studies does not appear to be a major reason for the difference in the reported incidence of CEA-positive MTCs. It is concluded that CEA is still a useful tumor marker for MTC and that it is detectable only in thyroid tumors originating from C cells, as seen in our series. The epitope defined by monoclonal antibody F106-88, present only on NCA, was found in 42.5% of all cases (49.2% of CEA-positive MTCs). The NCA immunoreactivity was located in the tumor cell cytoplasm as globular aggregates, which were also labeled for CEA.