RESUMO
BACKGROUND: Although some glycolytic intermediates have been shown to modulate several cell type formation and activation, the functional role of fructose 1,6-bisphosphate (FBP) on osteoclastogenesis is still unknown. METHODS: Osteoclastogenesis was evaluated on bone marrow preosteoclasts cultured with M-CSF - 30 ng/ml, RANKL - 10 ng/ml, and two concentrations of FBP (100 and 300 µM). TRAP-positive stained cells were counted, and osteoclastogenic marker genes expression were evaluated by qPCR. Osteoclasts resorption capacity was evaluated by the expression of specific enzymes and capacity to resorb a mineralized matrix. The NF-κB activation was detected using RAW 264.7, stably expressing luciferase on the NF-κB responsive promoter. RESULTS: We show that FBP, the product of the first stage of glycolysis, inhibited RANKL-induced osteoclasts differentiation and TRAP activity. The treatment of preosteoclasts with FBP attenuated osteoclast fusion and formation, without affecting cell viability. Moreover, the inhibition of several osteoclastogenic marker genes expression (TRAP, OSCAR, DC-STAMP, Integrin αv, NFATc1) by FBP correlates with a reduction of mineralized matrix resorption capacity. The mechanism underlying FBP-inhibition of osteoclastogenesis involves NF-κB/NFATc1 signaling pathway inhibition. CONCLUSION: Altogether these data show a protective role of a natural glycolytic intermediate in bone homeostasis that may have therapeutic benefit for osteolytic diseases.
Assuntos
Frutosedifosfatos/farmacologia , NF-kappa B/metabolismo , Fatores de Transcrição NFATC/genética , Osteoclastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Ligante RANK/farmacologia , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Fêmur/citologia , Masculino , Camundongos Endogâmicos C57BL , Osteoclastos/citologia , Tíbia/citologiaRESUMO
Metronomic chemotherapy refers to the administration of chemotherapy at low, nontoxic doses on a frequent schedule with no prolonged breaks. The aim of the study is to rationally develop a CPT-11 metronomic regimen in preclinical settings of colon cancer. In vitro cell proliferation, apoptosis and thrombospondin-1/vascular endothelial growth factor (TSP-1/VEGF) expression analyses were performed on endothelial (HUVEC, HMVEC-d) and colorectal cancer (HT-29, SW620) cells exposed for 144 h to metronomic concentrations of SN-38, the active metabolite of CPT-11. HT-29 human colorectal cancer xenograft model was used, and tumour growth, microvessel density and VEGF/TSP-1 quantification was performed in tumours. In vitro and in vivo combination studies with the tyrosine inhibitor semaxinib were also performed. SN-38 preferentially inhibited endothelial cell proliferation alone and interacted synergistically with semaxinib; it induced apoptosis and increased the expression and secretion of TSP-1. Metronomic CPT-11 alone and combined with semaxinib significantly inhibits tumour growth in the absence of toxicity, which was accompanied by decreases in microvessel density and increases in TSP-1 gene expression in tumour tissues. In vitro results show the antiangiogenic properties of low-concentration SN-38, suggesting a key role of TSP-1 in this effect. In vivo, the CPT-11 metronomic schedule is effective against tumour and microvessel growth without toxic effect on mice.
Assuntos
Inibidores da Angiogênese/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Camptotecina/análogos & derivados , Neoplasias Colorretais/irrigação sanguínea , Neoplasias Colorretais/tratamento farmacológico , Indóis/farmacologia , Pirróis/farmacologia , Inibidores da Angiogênese/administração & dosagem , Animais , Antineoplásicos Fitogênicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Apoptose/efeitos dos fármacos , Camptotecina/administração & dosagem , Camptotecina/farmacologia , Proliferação de Células/efeitos dos fármacos , Ensaio de Imunoadsorção Enzimática , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células HT29 , Humanos , Técnicas Imunoenzimáticas , Imuno-Histoquímica , Indóis/administração & dosagem , Irinotecano , Masculino , Camundongos , Camundongos Nus , Microcirculação/efeitos dos fármacos , Pirróis/administração & dosagem , Trombospondina 1/efeitos dos fármacos , Trombospondina 1/metabolismo , Transplante Heterólogo , Fator A de Crescimento do Endotélio Vascular/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
HRPT2 and parafibromin studies improved the diagnostic accuracy in two patients with primary hyperparathyroidism (PHPT) referred to us after surgery, in whom the clinical data were at variance with the pathological diagnosis of adenoma and carcinoma, respectively. Patients were referred to us after parathyroidectomy. Patient #1 had had a 1.5-cm tumor easily removed with a histological diagnosis of parathyroid carcinoma and normocalcemia for 2 years. Re-examination of the histology showed no cardinal signs of parathyroid cancer. Patient #2, with severe PHPT, had had the removal of a 3.5-cm tumor described histologically as adenoma. Ten years later PHPT recurred and persisted despite removal of two mildly enlarged parathyroid glands that were histologically normal. Re-review of the initial histology showed a trabecular pattern, fibrous bands, and atypical mitoses, suggesting an atypical adenoma. Because of the suspicion that case #1 could be an atypical adenoma and case #2 a carcinoma further molecular studies were performed. No HRPT2 and parafibromin abnormalities were identified in patient #1, strongly indicating a benign lesion. In patient #2, an HRPT2 germline mutation was found (E115X in exon 4) and associated with no parafibromin staining. These data, together with the clinical features, supported the suspicion of a parathyroid carcinoma that was confirmed by histological examination of further slides of the tumor, showing capsular and vascular invasion. A lung 1.5-cm nodule detected by computed tomography was excised. Histology showed a metastasis of parathyroid carcinoma. HRPT2 gene studies improved the diagnostic accuracy in 2 parathyroid tumors that are of uncertain type.
Assuntos
Hiperparatireoidismo Primário/genética , Neoplasias das Paratireoides/genética , Proteínas Supressoras de Tumor/genética , Adenoma/genética , Adenoma/patologia , Carcinoma/genética , Carcinoma/patologia , Humanos , Hiperparatireoidismo Primário/patologia , Masculino , Pessoa de Meia-Idade , Neoplasias das Paratireoides/patologiaRESUMO
Early onset of primary hyperparathyroidism (PHPT) and multiglandular involvement suggest a familial form in which germline mutation of a PHPT-related gene(s) and a somatic event at the same locus can be often demonstrated. We investigated the involvement of multiple endocrine neoplasia type 1 (MEN1) and HRPT2 genes in a 39-year-old man with recurrent PHPT. PHPT was firstly diagnosed at the age of 21 and the patient had two recurrences separated by extended periods of normocalcemia. This unusual history prompted us to investigate other family members and study the MEN1 and HRPT2 genes. An HRPT2 germline missense mutation in exon 3 (R91P) was found in the index case, which was associated with different HRPT2 somatic alterations in each of the three examined parathyroid tumors. These findings are consistent with Knudson's 'two hit' concept of biallelic inactivation of classical tumor suppressor genes. Screening of 15 asymptomatic relatives was negative for the R91P germline mutation. All the three abnormal parathyroid specimens showed cystic features at histology and were negative for parafibromin immunostaining. In one specimen, diffuse parafibromin staining was evident in a rim of normal parathyroid tissue surrounding the adenomatous lesion. Our study shows that different somatic genetic events at the HRPT2 locus are responsible for the asynchronous occurrence of multiple adenomas in a patient carrying an HRPT2 germline mutation. The finding of diffuse parafibromin staining in a rim of normal parathyroid tissue, but not in the contiguous adenomatous lesion, reinforces the concept that loss of parafibromin expression is responsible for the development of parathyroid tumors in this setting.
Assuntos
Hiperparatireoidismo Primário/patologia , Glândulas Paratireoides/patologia , Proteínas Supressoras de Tumor/genética , Adulto , Análise Mutacional de DNA , Mutação em Linhagem Germinativa , Humanos , Perda de Heterozigosidade , Masculino , Mutação de Sentido Incorreto , Glândulas Paratireoides/química , Proteínas Proto-Oncogênicas/genética , Recidiva , Proteínas Supressoras de Tumor/análiseRESUMO
Papillary thyroid carcinoma is a slow growing tumor with low metastatic potential. The most frequent sites of distant metastases are lung and bone; less frequent sites are brain, liver, kidney, and skin. Ovarian metastases from papillary thyroid carcinoma are exceptional. We describe a case of bilateral ovarian metastases from a papillary thyroid carcinoma associated with autoimmune thyroiditis in a 38-year-old woman who underwent thyroidectomy and cervical lymph-node dissection 7 years before, followed by 948 mCi of 131I. A primary ovarian cancer could be excluded by the typical pathological aspects of a papillary thyroid carcinoma in a context of an aggressive form of thyroid cancer. On the other hand, the clinical history and the absence of normal thyroid epithelium and teratomatous components could exclude a papillary thyroid carcinoma arising in struma ovarii. This is a singular case of papillary thyroid carcinoma metastasizing to the ovary, combined with an autoimmune thyroiditis.
Assuntos
Carcinoma Papilar/patologia , Neoplasias Ovarianas/patologia , Neoplasias Ovarianas/secundário , Neoplasias da Glândula Tireoide/patologia , Adulto , Carcinoma Papilar/terapia , Feminino , Humanos , Excisão de Linfonodo , Metástase Neoplásica , Neoplasias Ovarianas/terapia , Dosagem Radioterapêutica , Neoplasias da Glândula Tireoide/terapia , TireoidectomiaRESUMO
The aim of the present study was to test the polymerase chain reaction (PCR) as a tool to identify human papillomavirus (HPV) in routine cytological samples scraped from the uterine cervix. Moreover, attention has been focused on the correlation between HPV types and early intraepithelial lesions. The study involved 586 women who had undergone conventional Pap test. Analysis of HPV infection was performed by PCR and HPV typing by dot blot. In a group of 78 cases histologically diagnosed as high-grade squamous intraepithelial lesions (HSILs), the cytological diagnosis was correct in 92.3% and the HPV test was positive in 89.8% of cases; combined positivity at Pap and/or HPV tests raised this figure to 99.0%. In a group of 67 cases histologically diagnosed as low-grade squamous intraepithelial lesions (LSILs), the cytological diagnosis was correct in 73.1% and the PCR-based HPV test was positive in 64.2%; combined positivity at Pap and/or HPV tests raised this figure to 91.0%. This study confirms the limitations of screening programs based on Pap test only. Our results suggest, in fact, that adding the HPV test to primary screening could increase the yield of preinvasive cervical lesions.
Assuntos
Papillomaviridae/classificação , Infecções por Papillomavirus/diagnóstico , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/virologia , Esfregaço Vaginal , Adulto , Feminino , Humanos , Immunoblotting , Programas de Rastreamento , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos , Estudos Prospectivos , Displasia do Colo do Útero/patologiaRESUMO
The limited availability of human donors makes the search for alternative islet sources mandatory for future developments in pancreatic islet transplantation. In this study, we report on the massive isolation of bovine islets of proven in vitro and in vivo viability. The islets were prepared by collagenase digestion, sequential filtrations, and density-gradient purification by modifying a technique previously developed in our laboratory for the porcine pancreas. The prepurification yield was 2,743 +/- 78 islet equivalents (IE)/g pancreas (mean +/- SE), with a postpurification recovery of 78.7 +/- 2.2%. Purity ranged from 80 to 90%. The histological and immunocytochemical studies demonstrated the identity and integrity of the islets with well-preserved insulin-, glucagon-, and somatostatin-containing cells. The morphological integrity of cultured bovine islets was demonstrated for up to 4 weeks from isolation. Insulin secretion from freshly isolated islets was similar at 3.3 mmol/l glucose (0.36 +/- 0.06 pmol.IE-1.min-1) and at 14 mmol/l glucose (0.42 +/- 0.00 pmol.IE-1.min-1), and it increased significantly (P < 0.01) at 25 mmol/l glucose (1.44 +/- 0.12 pmol.IE-1.min-1). Arginine, theophylline, and propionic acid increased insulin secretion from freshly isolated islets at 3.3 and 14 mmol/l glucose, but not at 25 mmol/l glucose. Islets cultured at 37 degrees C in CMRL 1066 culture medium for at least 10 days were shown to become responsive to a lower glucose concentration, as demonstrated by the significant increase of insulin release in response to 14 mmol/l glucose, when compared with basal secretion. This recovered responsivity to glucose was maintained after 4 weeks of culture.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/citologia , Animais , Bovinos , Separação Celular/métodos , Células Cultivadas , Glucose/farmacologia , Insulina/metabolismo , Secreção de Insulina , Camundongos , Camundongos Nus , Taxa Secretória/efeitos dos fármacos , Fatores de Tempo , Transplante HeterólogoRESUMO
Inactivating mutations of the calcium-sensing receptor gene (CaR) might explain abnormalities in the regulation of both parathyroid cell proliferation and parathyroid hormone secretion. In a previous study, using RNAse A protection assay, no mutations were identified in a series of parathyroid specimens from patients with primary and secondary hyperparathyroidism, but the analysis was incomplete, since part of exon 6 could not be analyzed. In the present study, we examined the presence of mutations in the CaR gene in 20 parathyroid adenomas using direct sequencing. The entire coding region of the CaR gene was successfully amplified by polymerase chain reaction and directly sequenced. This analysis did not identify CaR gene mutations in any tumors studied. A polymorphism that encoded a single amino acid change (Ala826Thr) was identified in 4 parathyroid adenomas and in 8 of 50 normal unrelated subjects. Loss of heterozygosity studies were also performed on adenomas using markers for the locus of the CaR gene on chromosome 3q. No allelic loss was demonstrated. In conclusion, our results extend previous observation and suggest that clonal somatic mutations of the CaR gene and allelic loss at the CaR locus on chromosome 3q do not play a major role in the pathogenesis of sporadic parathyroid tumors.
Assuntos
Adenoma/genética , Cálcio/metabolismo , Neoplasias das Paratireoides/genética , Periodicidade , Receptores de Superfície Celular/genética , Adulto , Idoso , Análise Mutacional de DNA , Feminino , Humanos , Perda de Heterozigosidade , Masculino , Pessoa de Meia-Idade , Mutação , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Receptores de Detecção de CálcioRESUMO
Toxic multinodular goiter is a cause of nonautoimmune hyperthyroidism and is believed to differ in its nature and pathogenesis from toxic adenoma. Gain-of-function mutations of the TSH receptor gene have been identified as a cause of toxic adenoma. The pathogenesis at the molecular level of hyperfunctioning nodules in toxic multinodular goiter has yet not been reported. Six patients with a single hot nodule within a multinodular goiter and 11 patients with toxic thyroid adenoma were enrolled in our study. At histology five hyperfunctioning nodules in multinodular goiters showed the features of adenomas, and one was identified as a hyperplastic nodule. The entire exon 10 of the TSH receptor gene was directly sequenced after PCR amplification from genomic DNA obtained from surgical specimens. Functional studies of mutated receptors were performed in COS-7 cells. Five out of 6 (83%) hyperfunctioning nodules within toxic multinodular goiters harbored a TSH receptor mutation. A TSH receptor mutation was also evident in the hyperfunctioning nodule that at histology had the features of noncapsulated hyperplastic nodule. Among toxic adenomas, 8 out of 11 (72%) nodules harbored a TSH receptor mutation. All the mutations were heterozygotic and somatic. Nonfunctioning nodules, whether adenomas or hyperplastic nodules present in association with hyperfunctioning nodules in the same multinodular goiters, had no TSH receptor mutation. All the mutations identified had constitutive activity as assessed by cAMP production after expression in COS-7 cells. Hyperfunctioning thyroid nodules in multinodular goiters recognize the same pathogenetic event (TSH receptor mutation) as toxic adenoma. Other mechanisms are implicated in the growth of nonfunctioning thyroid nodules coexistent in the same gland.
Assuntos
Adenoma/genética , Bócio Nodular/genética , Mutação , Receptores da Tireotropina/genética , Neoplasias da Glândula Tireoide/genética , Nódulo da Glândula Tireoide/genética , Adulto , Animais , Células COS , AMP Cíclico/biossíntese , DNA/química , Feminino , Expressão Gênica , Bócio Nodular/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Receptores da Tireotropina/metabolismo , Análise de Sequência de DNA , Nódulo da Glândula Tireoide/fisiopatologia , Tireotropina/metabolismo , TransfecçãoRESUMO
The angiogenic phenotype of 13 normal adrenal glands (N), 13 aldosterone-producing adenomas (APA), 12 cortisol-producing adenomas (CPA), 13 nonfunctioning adrenal cortical adenomas (NFA), and 13 adrenal cortical carcinomas (CA) was investigated. Intratumoral vascular density was explored by CD34, a marker of endothelial cells, and the angiogenic status was investigated by vascular endothelial growth factor (VEGF) expression, an important angiogenic factor expressed by tumoral cells. Vascular density, quantified as the number of vessels per square millimeter, was significantly lower (P < 0.0001) in CA (110.3 +/- 27.8) than in N (336.6 +/- 14.5), APA (322.8 +/- 19.1), CPA (288.5 +/- 14.3), and NFA (274.2 +/- 19.8). VEGF expression, calculated as the percentage of positive cells, was significantly greater (P < 0.0001) in CA (85.3 +/- 2.1) than in APA (56.5 +/- 7.5), CPA (38.5 +/- 7.0), N (33.1 +/- 6.1), and NFA (0.76 +/- 0.6). In APA, a negative relation between CD34 and plasma renin activity (P < 0.0002) and a positive association between CD34 and aldosterone levels (P < 0.05) was found. In conclusion, the angiogenic phenotype of CA is characterized by VEGF overexpression but low vascularization, a finding suggesting a dissociation between angiogenic potential and neoangiogenic capabilities of these tumors. The lack of VEGF expression in NFA and the close association between angiogenesis and functional status in APA also suggest a possible influence of the angiogenic phenotype on hormonal secretion of these endocrine tumors.
Assuntos
Adenoma/irrigação sanguínea , Neoplasias do Córtex Suprarrenal/irrigação sanguínea , Córtex Suprarrenal/irrigação sanguínea , Neovascularização Patológica , Adenoma/química , Adenoma/metabolismo , Neoplasias do Córtex Suprarrenal/química , Neoplasias do Córtex Suprarrenal/metabolismo , Adulto , Idoso , Aldosterona/biossíntese , Aldosterona/sangue , Antígenos CD34/sangue , Vasos Sanguíneos/patologia , Fatores de Crescimento Endotelial/análise , Humanos , Hidrocortisona/biossíntese , Técnicas Imunoenzimáticas , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intercelular/análise , Linfocinas/análise , Microcirculação/anatomia & histologia , Pessoa de Meia-Idade , Renina/sangue , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio VascularRESUMO
Toxic multinodular goiter, a heterogeneous disease producing hyperthyroidism, is frequently found in iodine-deficient areas. The pathogenesis of this common clinical entity is still unclear. The aim of the present study was to search for activating TSH receptor (TSHr) or Gs alpha mutations in areas of toxic or functionally autonomous multinodular goiters that appeared hyperfunctioning at thyroid scintiscan but did not clearly correspond to definite nodules at physical or ultrasonographic examination. Surgical tissue specimens from nine patients were carefully dissected, matching thyroid scintiscan and thyroid ultrasonography, to isolate hyperfunctioning and nonfunctioning areas even if they did not correspond to well-defined nodules. TSHr and Gs alpha mutations were searched for by direct sequencing after PCR amplification of genomic DNA. Only 2 adenomas were identified at microscopic examination, whereas the remaining 18 hyperfunctioning areas corresponded to hyperplastic nodules containing multiple aggregates of micromacrofollicules not surrounded by a capsule. Activating TSHr mutations were detected in 14 of these 20 hyperfunctioning areas, whereas no mutation was identified in nonfunctioning nodules or areas contained in the same gland. No Gs alpha mutation was found. In conclusion, activating TSHr mutations are present in the majority of nonadenomatous hyperfunctioning nodules scattered throughout the gland in patients with toxic or functionally autonomous multinodular goiter.
Assuntos
Bócio Nodular/genética , Hipertireoidismo/genética , Mutação Puntual , Receptores da Tireotropina/genética , Adenoma/genética , Adulto , Feminino , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Bócio Nodular/patologia , Bócio Nodular/cirurgia , Humanos , Hiperplasia , Hipertireoidismo/etiologia , Hipertireoidismo/cirurgia , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Neoplasias da Glândula Tireoide/genéticaRESUMO
The molecular biology of follicular cell growth in thyroid nodules is still poorly understood. Because gain-of-function (activating) mutations of the thyroid-stimulating hormone receptor (TShR) and/or Gs alpha genes may confer TSh-independent growth advantage to neoplastic thyroid cells, we searched for somatic mutations of these genes in a series of hyperfunctioning and nonfunctioning follicular thyroid adenomas specifically selected for their homogeneous gross anatomy (single nodule in an otherwise normal thyroid gland). TShR gene mutations were identified by direct sequencing of exons 9 and 10 of the TShR gene in genomic DNA obtained from surgical specimens. Codons 201 and 227 of the Gs alpha gene were also analyzed. At histology, all hyperfunctioning nodules and 13 of 15 nonfunctioning nodules were diagnosed as follicular adenomas. Two nonfunctioning thyroid nodules, although showing a prevalent microfollicular pattern of growth, had histological features indicating malignant transformation (a minimally invasive follicular carcinoma and a focal papillary carcinoma). Activating mutations of the TShR gene were found in 12 of 15 hyperfunctioning follicular thyroid adenomas. In one hyperfunctioning adenoma, which was negative for TShR mutations, a mutation in codon 227 of the Gs alpha gene was identified. At variance with hyperfunctioning thyroid adenomas, no mutation of the TShR or Gs alpha genes was detected in nonfunctioning thyroid nodules. In conclusion, our findings clearly define a different molecular pathogenetic mechanism in hyperfunctioning and nonfunctioning follicular thyroid adenomas. Activation of the cAMP cascade, which leads to proliferation but maintains differentiation of follicular thyroid cells, typically occurs in hyperfunctioning thyroid adenomas. Oncogenes other than the TShR and Gs alpha genes are probably involved in nonfunctioning follicular adenomas.
Assuntos
Adenoma/genética , Neoplasias da Glândula Tireoide/genética , Adenoma/patologia , Adenoma/fisiopatologia , Adolescente , Adulto , Códon , Éxons , Feminino , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Receptores da Tireotropina/genética , Neoplasias da Glândula Tireoide/patologia , Neoplasias da Glândula Tireoide/fisiopatologiaRESUMO
A reduced expression of calcium-sensing receptor (CaR) messenger ribonucleic acid and protein accompanied by abnormalities in parathyroid cell proliferation and PTH secretion are present in primary hyperparathyroidism. We studied the expression of CaR protein by immunohistochemistry in 36 sporadic parathyroid adenomas and investigated the relationship between CaR expression and several preoperative clinical parameters, including the set-point of Ca(2+)-regulated PTH secretion (measured in vivo). The adenomas were classified in 4 categories according to the intensity of immunohistochemical staining: 5 (14%) showed a CaR staining intensity similar to that of normal parathyroid ( ), 10 (27%) showed moderate staining (++), 16 (45%) showed weak staining (+), and 5 (14%) were negative (-). The intensity of CaR staining was not related to preoperative serum Ca(2+), PTH levels or adenoma volume. Twenty-nine patients underwent preoperatively the calcium infusion test to evaluate the PTH-Ca(2+) set-point. Individual values of PTH-Ca(2+) set-point ranged from 1.38-1.93 mmol/L and were significantly correlated with basal Ca(2+) levels (r = 0.96; P: = 0. 0001) and adenoma volume (r = 0.5; P: = 0.01). The mean PTH-Ca(2+) set-point values were significantly different in the 4 groups of patients classified according to immunohistochemical staining intensity of their adenoma (P: = 0.025; F = 3.78); the mean PTH-Ca(2+) set-point was significantly higher in the groups classified as negative than in those classified as weak or moderate. No correlation was observed between the PTH-Ca(2+) set-point and basal PTH levels or between the percent maximal PTH inhibition and adenoma volume and basal PTH or Ca(2+) levels. In summary, our data suggest that there is a relationship between apparent CaR protein expression and PTH-Ca(2+) set-point abnormality, suggesting that a reduced receptor content might have an important role in the pathogenesis of primary hyperparathyroidism.
Assuntos
Cálcio/metabolismo , Hiperparatireoidismo/metabolismo , Glândulas Paratireoides/metabolismo , Hormônio Paratireóideo/metabolismo , Receptores de Superfície Celular/biossíntese , Adenoma/metabolismo , Adulto , Idoso , Western Blotting , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias das Paratireoides/metabolismo , Receptores de Detecção de CálcioRESUMO
In this study we comparatively analysed deltoid histochemistry, biochemistry and mitochondrial DNA (mtDNA) in two groups of ten sporadic ocular mitochondrial myopathies (OMM), respectively with and without ragged red fibres (RRF). (1) All but one RRF--patients presented the mild form of OMM with blepharoptosis but without ophthalmoplegia; (2) the occurrence of cytochrome c oxidase deficient (COX-) fibres was significantly higher in the RRF+ group, but four RRF- cases also showed COX- fibres; (3) no difference was observed in biochemical findings between the groups; (4) two RRF- patients without COX- fibres showed mtDNA heteroplasmy; (5) in two RRF- patients without deltoid mtDNA deletion, biopsy of an eyelid muscle showed significant mitochondrial alterations. These results suggest that the expression of a mitochondrial defect can vary and that the absence of RRF in a skeletal muscle biopsy does not necessarily rule out the diagnosis of OMM, if other data support that.
Assuntos
Blefaroptose/metabolismo , Mitocôndrias Musculares/metabolismo , Miopatias Mitocondriais/metabolismo , Oftalmoplegia Externa Progressiva Crônica/metabolismo , Adolescente , Adulto , Idoso , Blefaroptose/genética , Blefaroptose/patologia , Criança , DNA Mitocondrial/biossíntese , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mitocôndrias Musculares/enzimologia , Mitocôndrias Musculares/patologia , Miopatias Mitocondriais/genética , Miopatias Mitocondriais/patologia , Oftalmoplegia Externa Progressiva Crônica/genética , Oftalmoplegia Externa Progressiva Crônica/patologia , Oxirredutases/metabolismo , FenótipoRESUMO
In this study, bovine islets were isolated by collagenase digestion and density gradient purification, equilibrated stepwise with 3 M dimethylsulfoxide at 24 degrees C, nucleated at -150 degrees C, slow cooled at 0.25 degrees C/min down to -40 degrees C, and finally stored at -150 degrees C. After variable periods of time, the islets were quickly thawed at 37 degrees C, and dimethylsulfoxide was removed by 0.75 M sucrose. Postthawing recovery was 86 +/- 6% islet equivalents. Histology confirmed the identity and morphological integrity of the islets. Insulin release from the frozen-thawed islets was 0.13 +/- 0.03 microU/is/min at 3.3 mmol/L glucose and increased significantly (0.27 +/- 0.04 microU/is/min, P < 0.05) at 25 mmol/L glucose. Encapsulated, cryopreserved islets reversed hyperglycemia in diabetic mice after 6-8 days following implantation. Therefore, the method described in this paper permitted successful cryopreservation of bovine islets of proven in vitro and in vivo viability.
Assuntos
Criopreservação/métodos , Diabetes Mellitus Experimental/cirurgia , Transplante das Ilhotas Pancreáticas/fisiologia , Ilhotas Pancreáticas , Animais , Glicemia/metabolismo , Cápsulas , Bovinos , Células Cultivadas , Técnicas de Cultura/métodos , Diabetes Mellitus Experimental/sangue , Ilhotas Pancreáticas/citologia , Camundongos , Camundongos Endogâmicos BALB CRESUMO
Histidine-proline-rich glycoprotein (HPRG) is a protein that is synthesized by parenchimal liver cells. The protein has been implicated in a number of plasma-specific processes, including blood coagulation and fibrinolysis. We have recently reported the association of an HPRG-like protein with rabbit skeletal muscle AMP deaminase (AMPD). The results of the immunological analysis reported here demonstrate that an antibody against human plasma HPRG reacts with an AMPD preparation from human skeletal muscle. To probe the localization of the putative HPRG-like protein in human skeletal muscle, serial sections from frozen biopsy specimens were processed for immunohistochemical and histoenzymatic stains. A selective binding of the anti-HPRG antibody to Type IIB muscle fibers was detected, suggesting a preferential association of the novel protein to the AMPD isoenzyme contained in the fast-twitch glycolytic fibers.
Assuntos
AMP Desaminase/metabolismo , Músculo Esquelético/metabolismo , Proteínas/imunologia , AMP Desaminase/isolamento & purificação , Proteínas Sanguíneas/imunologia , Western Blotting , Histocitoquímica , Humanos , Imuno-Histoquímica , Fibras Musculares de Contração Rápida/metabolismo , Fibras Musculares de Contração Lenta/metabolismo , Músculo Esquelético/químicaRESUMO
Previous studies have demonstrated the tumor-targeting potential of radioiodinated 5-iodo-2'-deoxyuridine (IUdR) in experimental animal models following direct intratumoral or intracavitary administration. The aim of this study was to measure the tumor uptake and metabolic fate of 5-[125I]iodo-2'-deoxyuridine ([125I]UdR) in humans after a single intratumoral injection. Ten patients with colorectal cancer were injected intratumorally with [125I]UdR) (0.24-3.9 MBq) during endoscopy 24 hr before ablative surgery. Blood and urine samples were collected up to 72 hr after [125I]UdR injection. Following resection, the radioactivity in the tumor and the surrounding tissues was measured in a gamma counter, and microautoradiography was performed on semi-thin tissue sections to assess localization of the radiopharmaceutical at the cellular level. An average of 0.234% of the injected dose was present per gram of tumor (range 0.009-0.918, median value 0.147), and tumor-to-nontumor radioactivity incorporation ratios were high for colonic mucosa when the nontumor tissue was taken at 1 cm (mean 629, range 27-2391) and 15 cm (mean 2387, range 122-12674) from the injection site. Microautoradiography confirmed these high tumor-to-nontumor ratios and demonstrated localization of [125I]UdR in the tumor cell nuclei. These results suggest that radioiodinated IUdR might have potential as a tumor-targeting agent in humans, provided homogeneous intratumoral distribution of the radiopharmaceutical by a suitable route of loco-regional administration can be achieved.
Assuntos
Adenocarcinoma/diagnóstico por imagem , Neoplasias Colorretais/diagnóstico por imagem , Idoxuridina , Radioisótopos do Iodo , Radioimunodetecção , Idoso , Idoso de 80 Anos ou mais , Autorradiografia , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Injeções Intralesionais , Masculino , Pessoa de Meia-IdadeRESUMO
The long arm of chromosome 17 is a frequent target of allelic losses at multiple sites during breast cancer formation and progression. Several genes linked to breast carcinomas have been mapped on this chromosome such as BRCA1, NME and erbB2 genes. The aim of this work was to delineate a deletion map on chromosome 17q and to examine the role of loss of heterozygosity (LOH) during breast tumor development and progression looking for correlation between LOH on 17q and various histopathological parameters. A series of 71 human mammary carcinomas and the corresponding peripheral blood lymphocytes has been studied for loss of heterozygosity at 6 different polymorphic loci on chromosome 17q. 46 out of 71 (65%) tumors showed LOH on 17q. A positive correlation was found between allelic loss for BRCA1 flanking markers and young age at diagnosis. The absence of estrogen receptors was more frequently observed in tumors with deleted BRCA1 flanking markers.
RESUMO
The aim of the present study was to establish the usefulness of conventional thyroid ultrasonography (US) and color flow-doppler (CFD) sonography in the assessment of 'cold' thyroid nodules. One hundred and four consecutive patients with thyroid nodules who were to undergo surgery were examined by US and CFD before thyroidectomy. Conventional US evaluated the presence of a halo sign, hypoechogenicity and microcalcifications. The vascular pattern on CFD was classified as follows: Type I, absence of blood flow; Type II, perinodular blood flow; Type III, marked intranodular blood flow. On histology, 30 nodules were diagnosed as malignant (carcinoma, CA) and 74 as benign nodules (BN). On US, the echographic pattern most predictive for malignancy was absent halo sign, which was found in 20/30 CA and in 17/72 BN (P = 0.0001; specificity 77.0%; sensitivity 66.6%). The most specific combination on US, absent halo sign/microcalcifications, was found in 8/30 CA and in 5/74 BN (P < 0.005; specificity 93.2%, sensitivity 26.6%). The Type III pattern on CFD was found in 20/30 CA and 38/74 BN (not statistically significant). The combination of absent halo sign on US with Type III pattern on CFD was found in 15/30 CA and in 8/74 BN (P < 0.0001; specificity 89.0%, sensitivity 50.0%). The combination of absent halo sign/microcalcifications on US with Type III pattern on CFD was the most specific combination of the two techniques, being found in 5/30 CA and in only 2/74 BN (P < 0.01; specificity 97.2%, sensitivity 16.6%). In conclusion, findings on US and CFD become highly predictive for malignancy only when multiple signs are simultaneously present in a thyroid nodule. Thus the predictive value of these techniques increases at the expense of their sensitivity. Only in a small proportion of patients with thyroid carcinoma is US and CFD information highly predictive of malignancy.
Assuntos
Neoplasias da Glândula Tireoide/etiologia , Nódulo da Glândula Tireoide/complicações , Nódulo da Glândula Tireoide/diagnóstico por imagem , Ultrassonografia Doppler em Cores , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , CintilografiaRESUMO
OBJECTIVE: To determine the usefulness of parathyroid hormone (PTH) measurement in needle aspirates of a suspicious neck mass to confirm its parathyroid nature in patients with primary hyperparathyroidism. METHODS: Thirty-three patients with surgically proved primary hyperparathyroidism were submitted to neck ultrasound (US), parathyroid scintigraphy, and assay of PTH in the aspirate (PTHa) of the suspicious cervical mass. RESULTS: Based on the results of neck US and parathyroid scintigraphy, patients were divided into two groups. Group 1: 16 patients (seven with nodular goiter) with concordant positive US and scintigraphic results. In all but one patient, PTHa was detectable and often markedly elevated (> 1000 pg in 12 patients, between 292 pg and 803 pg in three patients and 53 pg in one patient). The patient with undetectable PTHa had a small lower left parathyroid adenoma (8x8x10 mm). Group 2: 17 patients (12 with nodular goiter) with discordant US and scintigraphic results. PTHa established the parathyroid nature of the mass in 13 cases (> 1000 pg in 8 patients, between 501 pg and 953 pg in three patients and 90 and 79 pg in two patients): 11 of these had a suspected lesion by US examination but the scintigraphy results were negative; two had a mass that gave positive scintigraphy results but was of uncertain origin according to US: in both cases an intrathyroidal parathyroid adenoma was found. PTHa was undetectable in four cases (three with nodular goiter): all of these had equivocal US results, and three had positive scans and one a negative scan. CONCLUSIONS: Assay of PTHa is a simple method and should be useful for confirming the parathyroid nature of a cervical mass in patients with discordant or non-diagnostic US and scintigraphic results.