Diagnostic value of quantitative SPECT/CT in assessing active sacroiliitis in patients with axial spondylarthritis and/or inflammatory low back pain

Fundamento. La precisión diagnóstica de la gammagrafía ósea (GO) aumenta con las imágenes SPECT/TAC haciendo conveniente reevaluar su utilidad diagnóstica en la sacroilitis de la espondiloartritis axial (EA). El objetivo fue comparar el rendimiento diagnóstico de la resonancia magnética (RM), la SPECT/TC y ambas pruebas combinadas, y evaluar la correlación entre los índices cuantitativos de ambas técnicas. Métodos. A 31 pacientes con EA activa y 22 con lumbalgia inflamatoria se les realizó una RM y una SPECT/TC de las articulaciones sacroilíacas y se calculó la precisión diagnóstica de ambas técnicas respecto al diagnóstico clínico. La correlación entre ambas pruebas se calculó comparando los índices de actividad del SPECT/TC con los sistemas de puntuación Berlín y SPARCC de RM. Resultados. Los valores de sensibilidad y especificidad de la SPECT/TC cuantitativa, tomando como punto de corte el cociente sacroilíaca/promontorio >1,36, fueron similares a los publicados para la RM. La combinación de ambas técnicas aumentó la sensibilidad manteniendo una alta especificidad. La correlación entre las escalas totales de RM y SPECT/TC fue moderada y mejoraba al utilizar únicamente las escalas de inflamación. Conclusiones. La SPECT/TC cuantitativa muestra una mejor precisión diagnóstica que la GO planar en la sacroilitis activa y una correlación moderada con las puntuaciones de RM. La combinación de ambas técnicas aumenta la precisión diagnóstica. Por tanto, la SPECT/TAC cuantitativa podría tener un papel relevante en el diagnóstico de sacroilitis en pacientes con alta sospecha de EA y RM negativa/no concluyente o en aquellos pacientes en los que no se pueda realizar una RM.(AU)

Background. The diagnostic accuracy of bone scintigraphy (BS) increases with SPECT/CT imaging. It would therefore be appropriate to reassess the diagnostic utility of scintigraphy in sacroiliitis with axial spondyloarthritis (SpA). The aim of this study was to compare the diagnostic performance of MRI, SPECT/CT and a combination of both techniques in sacroiliitis, and to evaluate the correlation between quantitative SPECT/CT indices and quantitative MRI inflammatory lesion scores. Methods. Thirty-one patients with active SpA and 22 patients with inflammatory low back pain underwent MRI and SPECT/CT of the sacroiliac joints. The diagnostic accuracy of both techniques was calculated using clinical diagnosis as the gold standard. The correlation between MRI and SPECT/CT was calculated by comparing the SPECT/CT activity indices and the Berlin/SPARCC scoring systems for MRI. Results. The sensitivity and specificity values in quantitative SPECT/CT, taking the sacroiliac/promontory ratio of >1.36 as the cut-off value, were close to those from MRI published in the literature. The combination of both techniques increased sensitivity while maintaining high specificity. There was a moderate correlation between SPECT/CT and MRI total scores. This correlation was improved by using solely the MRI inflammation scores. Conclusion. Quantitative SPECT/CT showed better diagnostic accuracy than planar scintigraphy and showed a moderate correlation with MRI scores in active sacroiliitis. The combination of both tests increased the diagnostic accuracy. Quantitative SPECT/CT could play a relevant role in the diagnosis of active sacroiliitis in patients with high a suspicion of SpA and a negative/inconclusive MRI test or in patients with whom MRI studies cannot be carried out.(AU)

Diagnostic value of quantitative SPECT/CT in assessing active sacroiliitis in patients with axial spondylarthritis and/or inflammatory low back pain.

BACKGROUND: The diagnostic accuracy of bone scintigraphy (BS) increases with SPECT/CT imaging. It would therefore be appropriate to reassess the diagnostic utility of scintigraphy in sacroiliitis with axial spondyloarthritis (SpA). The aim of this study was to compare the diagnostic performance of MRI, SPECT/CT and a combination of both techniques in sacro-iliitis, and to evaluate the correlation between quantitative SPECT/CT indices and quantitative MRI inflammatory lesion scores. METHODS: Thirty-one patients with active SpA and 22 patients with inflammatory low back pain underwent MRI and SPECT/CT of the sacroiliac joints. The diagnostic accuracy of both techniques was calculated using clinical diagnosis as the gold standard. The correlation between MRI and SPECT/CT was calculated by comparing the SPECT/CT activity indices and the Berlin/SPARCC scoring systems for MRI. RESULTS: The sensitivity and specificity values in quantitative SPECT/CT, taking the sacroiliac/promontory ratio of >1.36 as the cut-off value, were close to those from MRI published in the literature. The combination of both techniques increased sensitivity while maintaining high specificity. There was a moderate correlation between SPECT/CT and MRI total scores. This correlation was improved by using solely the MRI inflammation scores. CONCLUSION: Quantitative SPECT/CT showed better diagnostic accuracy than planar scintigraphy and showed a moderate correlation with MRI scores in active sacroiliitis. The combination of both tests increased the diagnostic accuracy. Quanti-tative SPECT/CT could play a relevant role in the diagnosis of active sacroiliitis in patients with high a suspicion of SpA and a negative/inconclusive MRI test or in patients with whom MRI studies cannot be carried out.

[Renal cell carcinoma with sarcomatoid and rhabdoid features: a clinico-pathological series of 74 cases]. / Carcinomas renales con rasgos sarcomatoides y rabdoides: estudio clínico-patológico de 74 casos.

Objetives. Our aim is to analyze and compare the clinico-pathological features in renal cell carcinomas (RCC) with sarcomatoid and rhaboid phenotype. MATERIAL AND METHODS: We reviewed consecutive patients with nephrectomy RCC from January 1988 to January 2015. The subtyping of the RCC followed the recommendations of the College of American Pathologists. Cases with at least 1% of sarcomatoid and/or rhabdoid change were selected. They were classified as sarcomatoid or rhabdoid according with the predominant morphology, considering the global frecuency of both phenotypes as dedifferentiated component. The following variables were collected: sex, age, symptoms and existence of metastases at diagnosis, parameters listed in the protocol of renal carcinoma of the American College of Pathologists, pattern of tumor growth, perineural invasion, percentage of both tumor necrosis and characteristics of the inflammatory infiltrate. They were described by mean / median or percentage, and compared with Student-t / Mann-Whitney U or ? 2 / Fisher, depending on the sample characteristics. RESULTS: From 1,258 RCC, we identified 45 RCC with sarcomatoid predominance (3,6%) and twenty-nine with rhabdoid predominance (2,3%). RCC with sarcomatoid features showed a higher dedifferentiated component and perineural invasion (27.5 vs. 13.5%, p=0.003 and 28.9 vs. 3.4%, p=0.006, respectively) than RCC with rhabdoid features, while the former showed a higher proportion of neutrophilic inflammation (44.8 vs. 22.2%, p=0.04) and arose more frequently over high grade RCC (55.9 vs. 90.5%, p<0,001). CONCLUSIONS: There was overlapping of the clinico-pathological features of RCC with sarcomatoid and rhaboid phenotype, except for the dedifferentiated component, perineural invasion and neutrophilic inflammation. This close relationship could be explained by a common underlying mechanism, the epithelial-mesenchymal transition, with a double morphological expression that, if confirmed, could lead to selecting patients that would benefit from follow-up or treatment depending on their molecular characteristics.

Carcinomas renales con rasgos sarcomatoides y rabdoides: estudio clínico-patológico de 74 casos / Renal cell carcinoma with sarcomatoid and rhabdoid features: a clinico-pathological series of 74 cases

Fundamento: Nuestro objetivo fue comparar las variables clínico-patológicas de los carcinomas renales (CCR) con fenotipos sarcomatoide y rabdoide. Material y métodos: Se revisaron 1.258 CCR de pacientes consecutivos nefrectomizados entre 1988 y 2015, y se seleccionaron aquellos con ≥1% de cambio sarcomatoide y/o rabdoide. Se clasificaron como sarcomatoide o rabdoide según el fenotipo predominante, considerándose componente desdiferenciado la suma del porcentaje de ambos. Se recopilaron: sexo y edad de los pacientes, síntomas y existencia de metástasis al diagnóstico, parámetros del protocolo de CCR del Colegio Americano de Patólogos, patrón de crecimiento tumoral, invasión perineural, porcentaje de necrosis tumoral y características del infiltrado inflamatorio. Se describieron mediante la media/mediana o el porcentaje y se compararon mediante t de Student/U de Mann-Whitney o χ2/F de Fisher. Resultados: Se identificaron 45 CCR con predominio sarcomatoide (3,6%) y 29 con rabdoide (2,3%); los primeros mostraron mayor componente indiferenciado e invasión perineural respecto a los CCR con rasgos rabdoides (27,5 vs. 13,5%; p=0,003 y 28,9 vs. 3,4%, p=0,006, respectivamente), mientras que estos mostraron doble frecuencia de inflamación neutrofílica (44,8 vs. 22,2%, p=0,04) y surgieron más frecuentemente sobre un CCR de alto grado (55,9 vs. 90,5%, p<0,001). Conclusiones: Los CCR con fenotipos sarcomatoide y rabdoide compartieron características clínico-patológicas, excepto para componente desdiferenciado, invasión perineural, inflamación neutrofílica y origen en CCR de alto grado. Esta similitud sugiere la presencia de un mecanismo común, la transición epitelio-mesénquima, con una expresión morfológica doble que, de confirmarse, podría suponer la posibilidad de seleccionar pacientes para tratamiento o seguimiento a partir de sus características moleculares

Objetives. Our aim is to analyze and compare the clinico-pathological features in renal cell carcinomas (RCC) with sarcomatoidand rhaboid phenotype. Material and methods: We reviewed 1,258 RCC from consecutive patients with nephrectomy from 1988 to 2015, and those with ≥1% of sarcomatoid and/or rhabdoid change were selected. They were classified as sarcomatoid or rhabdoid according with the predominant morphology, considering the global frecuency of both phenotypes as dedifferentiated component. The following variables were collected: sex, age, symptoms and existence of metastases at diagnosis, parameters listed in the protocol of renal carcinoma of the American College of Pathologists, pattern of tumor growth, perineural invasion, percentage of both tumor necrosis and characteristics of the inflammatory infiltrate. They were described by mean/median or percentage, and compared with Student-t/Mann-Whitney U or χ2/Fisher). Results: We identified 45 RCC with sarcomatoid predominance (3,6%) and twenty-nine with rhabdoid predominance (2,3%); the first one showed a higher dedifferentiated component and perineural invasion (27.5 vs. 13.5%, p=0.003 and 28.9 vs. 3.4%, p=0.006, respectively), while the former showed a higher proportion of neutrophilic inflammation (44.8 vs. 22.2%, p=0.04) and arose more frequently over high grade RCC (55.9 vs. 90.5%, p<0,001). Conclusions: There was overlapping of the clinico-pathological features of RCC with sarcomatoid and rhaboid phenotype, except for dedifferentiated component, perineural invasion and neutrophilic inflammation. This close relationship could be explained by a common underlying mechanism, the epithelial-mesenchymal transition, with a double morphological expression that, if confirmed, could lead to selecting patients that would benefit from follow-up or treatment depending on their molecular characteristics

Perineural Invasion is a Major Prognostic and Predictive Factor of Response to Adjuvant Chemotherapy in Stage I-II Colon Cancer.

BACKGROUND: Perineural invasion (PNI) in colon cancer (CC) has been associated with poorer prognosis even in stage II disease (T3-4 N0 M0). The aim of this study is to analyze prognostic histopathologic factors in stage II colon cancer in patients treated with curative surgery as established in National Comprehensive Cancer Network guidelines. METHODS: From a prospective database of CC cases, 507 patients with stage I-II disease who had undergone curative resection from January 2000 and December 2012 were identified. Of these patients, 17 % received 5-flurouracil-based adjuvant chemotherapy. Together with demographic and anatomic variables, we also studied perineural and lymphovascular invasion, degree of differentiation, and their correlation with disease-free survival. RESULTS: Perineural invasion was identified in 57 patients (11.2 %) and lymphovascular invasion (LVI) in 82 (16.2 %) of the 507 patients. Perineural invasion was associated with LVI, the depth of invasion of the wall of the colon, and location of the tumor. Overall and disease-free survival of the complete series at 5 and 10 years was 89.5, 85.2, 83.2 and 81.6 %, respectively. In the PNI positive patients, disease-free survival at 5 years was significantly lower than in those without PNI (73.5 vs 88.6 %; p = 0.02). Multivariate analysis showed the presence of PNI to be a significant independent prognostic factor for disease-free survival (p = 0.025). Adjuvant chemotherapy reversed the impact of PNI on 5- to 10-year disease-free survival. CONCLUSIONS: PNI a major prognostic and predictive factor in stage II colon cancer, and our results support the use of adjuvant chemotherapy in patients with PNI.

Patterns and management of distant failure in locally advanced rectal cancer: a cohort study

PURPOSE: To determine the long-term outcomes of locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiation (CRT) and surgery, and to analyze the management and survival once distant failure has developed. METHODS: Data from LARC patients treated from 2000 to 2010 were retrospectively reviewed. CRT protocols were based on fluoropirimidines ± oxaliplatin. Follow-up consisted of physical examination, carcinoembryonic antigen levels, and chest-abdominal-pelvic CT scan. RESULTS: The study included 228 patients with a mean age of 59 years. Forty-eight (21.1 %) patients had distant recurrence and 6 patients (2.6 %) had local recurrence. Median follow-up was 49 months. The 5- and 10-year actuarial disease free survival was 75.3 and 65.0 %, respectively. The 5- and 10-year actuarial overall survival (OS) was 89.6 and 71.2 %, respectively. Patients were classified as having liver (14 patients) or lung (27 patients) relapse according to the organ firstly metastasized. The variables significantly associated by univariate Cox analysis to survival were the achievement of an R0 metastases resection and the Köhne risk index, while the metastatic site showed a statistical trend. By multivariate Cox analysis, the only variable associated with survival was a R0 resection (HR = 16.3, p\0.001). Median OS for patients undergoing a R0 resection was 73 months (95 % CI 67.8-78.2) compared to 25 months (95 % CI 5.47-44.5) in those non-operated patients (p\0.001). CONCLUSIONS: Combined treatment for LARC obtains a 5-year OS rounding 90 %. Follow-up based on thoracic abdominal CT scan allows an early diagnosis of metastatic lesions. Surgical resection of metastases, regardless of their location, greatly increases the patient's survival rate

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Patterns and management of distant failure in locally advanced rectal cancer: a cohort study.

PURPOSE: To determine the long-term outcomes of locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiation (CRT) and surgery, and to analyze the management and survival once distant failure has developed. METHODS: Data from LARC patients treated from 2000 to 2010 were retrospectively reviewed. CRT protocols were based on fluoropirimidines ± oxaliplatin. Follow-up consisted of physical examination, carcinoembryonic antigen levels, and chest-abdominal-pelvic CT scan. RESULTS: The study included 228 patients with a mean age of 59 years. Forty-eight (21.1 %) patients had distant recurrence and 6 patients (2.6 %) had local recurrence. Median follow-up was 49 months. The 5- and 10-year actuarial disease free survival was 75.3 and 65.0 %, respectively. The 5- and 10-year actuarial overall survival (OS) was 89.6 and 71.2 %, respectively. Patients were classified as having liver (14 patients) or lung (27 patients) relapse according to the organ firstly metastasized. The variables significantly associated by univariate Cox analysis to survival were the achievement of an R0 metastases resection and the Köhne risk index, while the metastatic site showed a statistical trend. By multivariate Cox analysis, the only variable associated with survival was a R0 resection (HR = 16.3, p < 0.001). Median OS for patients undergoing a R0 resection was 73 months (95 % CI 67.8-78.2) compared to 25 months (95 % CI 5.47-44.5) in those non-operated patients (p < 0.001). CONCLUSIONS: Combined treatment for LARC obtains a 5-year OS rounding 90 %. Follow-up based on thoracic-abdominal CT scan allows an early diagnosis of metastatic lesions. Surgical resection of metastases, regardless of their location, greatly increases the patient's survival rate.

Impact of perineural and lymphovascular invasion on oncological outcomes in rectal cancer treated with neoadjuvant chemoradiotherapy and surgery.

BACKGROUND: The prognostic significance of perineural and/or lymphovascular invasion (PLVI) and its relationship with tumor regression grade (TRG) in patients with locally advanced rectal cancer (LARC) treated with neoadjuvant chemoradiotherapy (CRT) and surgery. METHODS: A total of 324 patients with LARC were treated with CRT and operated on between January 1992 and June 2007. Tumors were graded using a quantitative 5-grade TRG classification and the presence of PLVI was histologically studied. RESULTS: At a median follow-up of 79.0 months (range 3-250 months), a total of 80 patients (24.7%) relapsed. The observed 5- and 10-year overall survival (OS) was 83.2 and 74.9 %, respectively. The 5- and 10-year disease-free survival (DFS) was 75.1 and 71.4%, respectively. A significant correlation was found between the TRG and survival (log rank, p < 0.001). The 10-year OS was 32.7% for grade 1, 63.8% for grade 2, 75.0% for grade 3, 90.4% for grade 3+, and 96.0%,for grade 4. The 10-year DFS was 31.8% for grade 1, 58.6% for grade 2, 70.4% for grade 3, 88.4% for grade 3+, and 97.1% for grade 4. In patients with PLVI, the TRG had no impact on survival. When excluding patients with PLVI, the TRG was an independent prognostic factor for OS and DFS. CONCLUSIONS: The presence of PLVI is a more powerful prognostic factor than TRG in LARC patients treated with neoadjuvant CRT followed by surgery. PLVI denotes an aggressive phenotype, suggesting that these patients may benefit from adjuvant systemic therapy.

Can component-based microarray replace fluorescent enzimoimmunoassay in the diagnosis of grass and cypress pollen allergy?

BACKGROUND: Few data on the diagnostic accuracy in pollinosis of the microarray ISAC of allergens are available. OBJECTIVE: We aim to comparatively analyse ISAC CRD103 with the whole-extract ImmunoCAP in grass and cypress pollen allergy, evaluating the suitability of the manufacturer's recommended cut-off points for both techniques. METHODS: We studied 120 atopic patients grouped into grass and cypress pollen-allergic patients and controls based on clinical history and skin prick tests. Specific IgE against Phleum pratense and Cupressus arizonica by ImmunoCAP and ISAC CRD103 were performed on all subjects. RESULTS: In the grass pollen group (43 allergic/26 controls), both microarray and CAP showed high sensitivity (Se) and specificity (Sp) values (ISAC: Se 97.7, Sp 92.3; CAP: Se 95.3, Sp 96.1) for recommended cut-off points. Comparing the optimal (ISAC: 0.4 ISU; CAP: 0.33 kU/L) with the recommended cut-off points within the same technique, diagnostic agreement was observed in both techniques. Thus, CAP and ISAC showed similar diagnostic performance in grass pollen allergy when using recommended cut-off points. In cypress pollen group (12 allergic/92 controls), the microarray (Se: 91.7, Sp 91.3) showed similar Se but significantly higher Sp (P=0.034) than CAP (Se: 91.7, Sp: 80.4) using recommended cut-off points. However, although diagnostic performance of the microarray did not change when comparing the optimal (0.82 ISU) with the recommended cut-off point, CAP improved diagnosis of cypress pollen allergy, when applying the optimal (0.66 kU/L)(CAP Se: 91.7, Sp: 89.1) instead of the manufacturer's recommended cut-off point. Thus, when the most suitable cut-off point for both techniques (ISAC: 0.3 ISU; CAP: 0.66 kU/L) is selected, microarray and CAP provide equivalent diagnoses. CONCLUSIONS AND CLINICAL RELEVANCE: Component-based microarray ISAC CRD103 and whole-allergen CAP showed high Se and Sp diagnosing equally grass and cypress pollen allergy. The cut-off point for each allergen should be properly applied for both techniques.

Association between [18F]fluorodeoxyglucose uptake and prognostic parameters in breast cancer.

BACKGROUND: This study analysed the correlation between [(18)F]fluorodeoxyglucose (FDG) uptake assessed by positron emission tomography (PET) in breast tumours, and histopathological and inmunohistochemical prognostic factors. METHODS: FDG-PET was performed before surgery in 275 women with primary breast cancer. The standarized uptake value (SUV) was compared with histopathological findings after surgery. RESULTS: A positive relationship was found between the SUV and tumour size (r = 0.46, P < 0.001), axillary lymph node status (P < 0.001), histological type (P < 0.001), histological grade (P < 0.001), oestrogen receptor status (P < 0.001), p53 (P < 0.001) and Ki-67 (P < 0.001) expression. Multivariable linear regression showed that tumour size, histological grade, Ki-67 expression, oestrogen receptor status and histological type were significantly related to the SUV. CONCLUSION: The SUV is a preoperative and non-invasive metabolic factor that relates to some prognostic factors in breast cancer.

Fluorodeoxyglucose positron emission tomography with sentinel lymph node biopsy for evaluation of axillary involvement in breast cancer.

BACKGROUND: This study analysed the value of [(18)F]fluorodeoxyglucose positron emission tomography (FDG-PET) in detecting axillary lymph node involvement in women with breast cancer. METHODS: In the first 150 women in this prospective study, axillary lymph node dissection (ALND) was performed regardless of the PET results. In a second group (125 women) FDG-PET was complemented with sentinel lymph node biopsy (SLNB) only in those who did not have pathological axillary uptake. RESULTS: The sensitivity and specificity of FDG-PET in detecting axillary involvement was 84.5 and 98.5 per cent respectively in the whole series of 275 patients, with two false-positive and 22 false-negative results. False-negative results were associated with some intrinsic tumour characteristics. In 21 women, PET revealed pathological uptake, suggesting involvement of the internal mammary lymph node chain. Whole-body PET identified a second synchronous tumour in five asymptomatic patients and haematogenous metastases in two patients. CONCLUSION: The high positive predictive value of PET (98.4 per cent) suggests that FDG uptake in the axilla could be an indication for full ALND without previous SLNB.

18F-FDG PET complemented with sentinel lymph node biopsy in the detection of axillary involvement in breast cancer.

AIM: The presence of axillary involvement is the most important prognostic factor in breast cancer. This study analysis the value of 18F-FDG PET in the detection of the lymph node status. METHODS: This study includes 200 breast cancer patients. The PET scans were obtained after the injection of 370 MBq of 18F-FDG; the breast areas, axillary, supraclavicular and internal mammary lymph node chains were evaluated. In a subgroup of 100 patients the PET-FDG scan was complemented with the study of the sentinel node (SN) in those cases which did not demonstrate pathological lymph node uptake. The standardized uptake value (SUV) was related to the tumour characteristics of size, histological type, axillary status and histological grading. RESULTS: The sensitivity and specificity of PET-FDG in the detection of axillary involvement was 84.1 and 97.8%, respectively. Seventeen false negative cases were obtained, and were associated with low SUV in the mammary tumour. In 15 cases the PET-FDG scans revealed pathological uptake foci that suggested involvement of the internal mammary chain. CONCLUSIONS: The PET-FDG avoids routine SN study in those cases presenting axillary uptake, but it must be complemented by sentinel node study in those cases without pathological uptake. The association of PET-FDG and SN improves the sensitivity in the detection of axillary involvement. Its sensitivity and specificity in the analysis of axillary status can be extended to the evaluation of the internal mammary chain.

An immunocytochemical study of the respiratory system of Podarcis hispanica (Reptilia).

The endocrine cells and nerves of the respiratory tract of the reptile Podarcis hispanica were investigated by immunocytochemistry under light microscopy. Immunoreactivities were more numerous in the lung than in the trachea. In the tracheal epithelium, endocrine cells immunoreactive to PHI, PYY, and Leu-enkephalin were detected, while immunoreactivity to serotonin, calcitonin, CGRP, PHI, and Leu-enkephalin was found in pulmonary endocrine cells. Numerous nerve fibers positive to NSE, PGP9.5, chromogranin, tyrosine hydroxylase, calcitonin, CGRP, bombesin, substance P, VIP, NPY, and PYY were found in the lungs. In addition, neurons positive to NSE and PGP9.5 were also found. Immunoreactivities to PHI and PYY in cells and to NSE, PGP9.5, chromogranin, tyrosine hydroxylase, calcitonin, CGRP, and PYY in nerves, were reported first in the respiratory system of reptiles.

Colocalization of immunoreactivities to serotonin, calcitonin and CGRP in endocrine pulmonary cells of the iberian lizard Podarcis hispanica (Reptilia).

The coexistence of immunoreactivities to serotonin (5HT), calcitonin (CT) and calcitonin gene-related peptide (CGRP) was studied in pulmonary endocrine cells of the Iberian lizard by immunocytochemistry and in semithin/thin sections under light and electron microscope. Immunostaining of serial sections revealed coexistence of 5HT/CT/CGRP immunoreactivities in some cells, while in others only 5HT/CT or CGRP immunoreactivities were found. Appropriate absorption controls excluded crossreactivity between the antisera used. Ultrastructurally, cells immunoreactive to 5HT/CT and CGRP share similar features, with round or slightly ovoid secretory granules of mean diameter from 165 to 180 nm. The possible functional significance of the copresence of 5HT, CT and CGRP is discussed.

Some peptide-like colocalizations in endocrine cells of the pyloric caeca and the intestine of Oncorhynchus mykiss (Teleostei).

The coexistence of immunoreactivities to cholecystokinin, glucagon, glucagon-like peptide 1, salmon pancreatic polypeptide, neuropeptide tyrosine, and peptide tyrosine tyrosine was studied immunocytochemically, revealing for the first time in fish intestine the existence in the same cell of immunoreactivities to cholecystokinin-glucagon/glucagon-like peptide 1, cholecystokinin-salmon pancreatic polypeptide, glucagon/glucagon-like peptide 1-salmon pancreatic polypeptide, glucagon/glucagon-like peptide 1-neuropeptide tyrosine, salmon pancreatic polypeptide tyrosine tyrosine, and glucagon/glucagon-like peptide 1-peptide tyrosine tyrosine. Colocalization of cholecystokinin-salmon pancreatic polypeptide was observed only in the pyloric caeca of the rainbow trout Oncorhynchus mykiss, while the other colocalizations also occurred in proximal and middle intestinal segments. In all cases, endocrine cells immunoreactive to only one of the paired antisera were detected except for anti-glucagon and anti-glucagon-like peptide 1, which always immunostained the same cells.

Endocrine cells and nerves in the pyloric ceca and the intestine of Oncorhynchus mykiss (Teleostei): an immunocytochemical study.

The endocrine cells of rainbow trout pyloric ceca and intestine have been investigated immunocytochemically using the avidin-biotin method. Twenty-six antisera were tested and 13 endocrine cell types immunoreacted with antisera to serotonin, somatostatin-25, bombesin, C-flanking bombesin, substance P, salmon PP, NPY, PYY, PP, glucagon, GLP1, Met-enkephalin, and CCK/G. Glucagon and GLP1 immunoreactivities appear in the same cells. Nerves positive to serotonin, substance P, PHI, and VIP were also found. The presence of cells positive to somatostatin-25, C-flanking bombesin, and salmon PP are described for the first time in fish intestine.