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1.
Pediatr Surg Int ; 21(4): 240-54, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15726388

RESUMO

Germ cell development is an active process in normal testes during the first 4 years after birth, with transformation of the neonatal gonocytes into adult dark spermatogonia and then primary spermatocytes. The hormonal regulation of these changes is not fully understood, with evidence both for and against a role for gonadotrophins and androgens. Early surgical intervention in infancy aims to prevent or reverse germ cell maldevelopment. Although hormonal treatment for maldescent has been shown to be ineffective, there is still controversy over whether it may be useful as an adjunct to surgery to stimulate germ cells. Current evidence suggests that hormonal therapy may not stimulate transformation of neonatal gonocytes but may trigger prepubertal mitosis of primary spermatocytes. Further studies are required to determine the role of hormone treatment on germ cell development.


Assuntos
Criptorquidismo/embriologia , Criptorquidismo/fisiopatologia , Espermatozoides/citologia , Espermatozoides/fisiologia , Testículo/citologia , Transformação Celular Neoplásica , Criptorquidismo/tratamento farmacológico , Criptorquidismo/cirurgia , Humanos , Sistema Hipotálamo-Hipofisário/fisiologia , Masculino , Neoplasias Testiculares/embriologia , Neoplasias Testiculares/epidemiologia , Testículo/fisiopatologia
2.
Eur J Pediatr Surg ; 12(1): 3-7, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11967751

RESUMO

BACKGROUND/PURPOSE: Administration of Adriamycin to pregnant rats leads to the development of esophageal atresia with tracheo-esophageal fistula. This defect arises from failure of the trachea to develop normally from the primitive foregut; instead,the upper foregut differentiates into trachea, then continues to the lower esophageal segment as a tracheo-esophageal fistula. Our aim was to explore the possibility of growing Adriamycin-exposed embryos using a whole-embryo culture technique and to determine whether or not esophageal atresia with tracheo-esophageal fistula could be prevented in an Adriamycin-treated rat model. METHODS: Rat embryos were exposed to Adriamycin in utero on days 6 - 9 of gestation, removed on day 10 and grown in vitro as described by New (11) for 48 hours using 100% serum from animals not exposed to Adriamycin. RESULTS: Thirty Adriamycin-exposed embryos were grown in vitro using normal serum. Histologic assessment of tracheo-esophageal development showed that 14 embryos had normal development, while 16 developed esophageal atresia. CONCLUSIONS: Growth of Adriamycin-exposed embryos was successful using "whole-embryo culture technique"; abnormal tracheo-esophageal development could in some cases be altered by removing the embryos at day 10 and exposing them to normal serum for 48 hours.


Assuntos
Antibióticos Antineoplásicos/efeitos adversos , Antineoplásicos/efeitos adversos , Doxorrubicina/efeitos adversos , Embrião de Mamíferos/efeitos dos fármacos , Atresia Esofágica/induzido quimicamente , Técnicas de Cultura de Órgãos/métodos , Anormalidades Induzidas por Medicamentos , Animais , Meios de Cultura , Atresia Esofágica/prevenção & controle , Feminino , Exposição Materna , Gravidez , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Fístula Traqueoesofágica/induzido quimicamente , Fístula Traqueoesofágica/prevenção & controle
3.
J Reprod Fertil ; 119(1): 85-91, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10864817

RESUMO

At birth, the mouse gonocyte does not resume mitotic activity for several days in vivo but, in an in vitro clonogenic system, cell division commences soon after culture. Somatic testis cell underlays had potent inhibitory activity on gonocyte-derived colony formation (23 +/- 15% compared with 84 +/- 1% in controls; P = 0.0001) when added to cultures of gonocytes in vitro. A Sertoli cell line, TM4B, had an even more pronounced effect on gonocyte clonogenic capacity, with 1 +/- 1% compared with 72 +/- 17% colony formation in controls (P = 0.0003). Testis cells appeared to have a direct inhibitory effect since testis-conditioned medium did not show a significant reduction in the number of colonies. The observed reduction in colony formation with the testis cell underlay was not accounted for by decreased attachment of gonocytes as simultaneous addition of a single cell suspension of testis cells was still effective in significantly reducing colony number when compared with controls (P = 0.01). Therefore, the observed inhibition exerted by testis cells appears to be a consequence of decreased proliferation of gonocytes. Growth factors belonging to the transforming growth factor beta superfamily which are known to be expressed in testis, such as transforming growth factor beta and epidermal growth factor, did not exert any inhibitory action on gonocyte-derived colony formation when added together or alone. However, a shift to a smaller colony size occurred in the presence of transforming growth factor beta and transforming growth factor beta plus epidermal growth factor, indicating a reduction in colony cell proliferation. Evidence for the expression of the Müllerian inhibiting substance receptor on newborn gonocytes using in situ hybridization was inconclusive. This finding was in agreement with the lack of a direct action of Müllerian inhibiting substance on the formation of gonocyte-derived colonies in vitro. Leukaemia inhibitory factor, alone or in combination with forskolin, had neither an inhibitory nor an enhancing effect on gonocyte-derived colony formation. An in vitro clonogenic method to assay for the proliferation of gonocytes in the presence of specific growth factors, cell lines, testis cell underlays and cell suspensions was used to identify a somatic cell-mediated inhibitor which may be responsible for the inhibitory action on gonocyte proliferation in vivo shortly after birth.


Assuntos
Substâncias de Crescimento/farmacologia , Interleucina-6 , Mitose/efeitos dos fármacos , Espermatozoides/citologia , Testículo/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Células Clonais , Fator de Crescimento Epidérmico/farmacologia , Inibidores do Crescimento/farmacologia , Hibridização In Situ , Fator Inibidor de Leucemia , Linfocinas/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos ICR , Oligonucleotídeos Antissenso , Receptores de Peptídeos/análise , Receptores de Peptídeos/genética , Receptores de Fatores de Crescimento Transformadores beta , Espermatozoides/efeitos dos fármacos , Testículo/citologia , Fator de Crescimento Transformador beta/farmacologia
4.
Cells Tissues Organs ; 166(3): 249-58, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10765020

RESUMO

The processus vaginalis (PV) is a peritoneal diverticulum which forms to allow descent of the fetal testis to the scrotum. During human development fusion and obliteration of the PV often fails to occur with the result that inguinal hernias are the most prevalent congenital abnormality requiring surgery in childhood. Androgen is proposed to regulate testicular descent via the genitofemoral nerve which releases the neuropeptide calcitonin gene-related peptide (CGRP). It is possible that subsequent fusion of the PV and tissue remodelling following descent is indirectly controlled by androgen via CGRP action. An organ culture assay was developed to assess fusion of the PV taken from inguinal herniotomy in infants. Fusion was induced in vitro by CGRP but not by CGRP 8-37, CGRP 27-37 or dihydrotestosterone in equimolar concentrations. Fusion was accompanied by transformation of the epithelium, as shown by staining of intermediate filament proteins, cytokeratin and vimentin. Localization studies for CGRP receptors on 25 specimens indicated CGRP acts on mesenchymal fibroblasts but not directly on PV epithelium suggesting an indirect pathway. Hepatocyte growth factor/scatter factor was found to induce fusion of PV and may be involved as an intermediate molecule in the fusion cascade. This study represents the first approach to understanding the humoral control and underlying mechanism by which the PV fuses.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Hérnia Inguinal/patologia , Testículo/fisiopatologia , Animais , Fusão Celular/fisiologia , Criança , Pré-Escolar , Epitélio/patologia , Feminino , Humanos , Imuno-Histoquímica , Lactente , Masculino , Técnicas de Cultura de Órgãos , Ratos , Receptores de Peptídeo Relacionado com o Gene de Calcitonina/metabolismo , Testículo/embriologia , Coleta de Tecidos e Órgãos
5.
J Pediatr Surg ; 35(1): 77-81, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10646779

RESUMO

BACKGROUND/PURPOSE: Recent evidence has suggested that calcitonin gene-related peptide (CGRP), which is released from the genitofemoral nerve, may trigger fusion of the patent processus vaginalis in children with inguinal hernia. The purpose of this study was to determine whether CGRP triggers the release of mesenchymal factors leading to subsequent fusion of the processus vaginalis. METHODS: The response of cultured epithelial cells derived from the patent processus vaginalis was analysed by a novel in vitro culture system. Epithelial cells lining fresh hernial sacs (removed at inguinal herniotomy) were detached enzymatically and cultured for 72 hours on Micropore filters, in the presence of either 100 ng/mL hepatocyte growth factor (HGF), 7.4 x 10(-6) mol/L CGRP (amino acids 1 to 37), 7.4 x 10(-6) mol/L CGRP (8 to 37) antagonist, 10% fetal calf serum (FCS), or serum-free medium (SFM) alone. Transformation from an epithelial cell morphology to motile mesenchymal fibroblast-like cells was assessed by an average migration score (AMS), ranging from 0 with no sign of migration, to 3 with greater than 75% of cells migrating. Confocal microscopy was used to record changes in expression of epithelial (cytokeratin) and mesenchymal (vimentin) markers, as well as actin. Beta-catenin also was examined because it is part of the molecular complex that links cadherins to actin resulting in cell-cell adhesion. RESULTS: Epithelial and mesenchymal markers underwent either down-regulation or up-regulation as epithelial cell sheets broke apart and individual cells commenced migration. The AMS after 72 hours of culture was 0.22 with SFM (control); with FCS the score was 1.4 (P < .01). The AMS score with CGRP (1 to 37) was 0.55 (P = .165) and with its analogue, CGRP (8 to 37), which is a competitive inhibitor, 0.67 (P = .309). Neither was significant. HGF caused a significant increase in the AMS to 1.56 (P = .01). CONCLUSION: Both HGF and FCS (which contains various undefined peptides and growth factors) produced transformation of hernial sac epithelial cells, whereas CGRP and its inactive analogue did not. CGRP receptors are localised to mesenchymal fibroblasts within the processus vaginalis connective tissue, suggesting that CGRP could act indirectly via HGF, which, in turn, promotes fusion of the processus vaginalis. In the future, a nonsurgical treatment of inguinal herniae in children might be possible by the local administration of agents which promote fusion.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina/fisiologia , Fator de Crescimento de Hepatócito/fisiologia , Hérnia Inguinal/fisiopatologia , Transativadores , Actinas/análise , Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Criança , Proteínas do Citoesqueleto/análise , Células Epiteliais/química , Células Epiteliais/fisiologia , Feminino , Fator de Crescimento de Hepatócito/farmacologia , Hérnia Inguinal/patologia , Humanos , Imuno-Histoquímica , Queratinas/análise , Masculino , Vimentina/análise , beta Catenina
6.
J Pediatr Surg ; 34(5): 872-5; discussion 876, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10359198

RESUMO

PURPOSE: The aim of this study was to determine whether apoptosis participates in separation of the foregut into trachea and esophagus and to evaluate the potential role of apoptosis in the development of esophageal atresia and tracheoesophageal fistula (EA + TEF) induced by Adriamycin. METHODS: Timed-pregnant rats were injected daily with either saline or Adriamycin (2 mg/kg) intraperitoneally on days 6 to 9 of gestation. Paraffin sections were prepared from 31 experimental and 31 control embryos at days 12 and 13 of gestation. Condensed nuclei were identified on the paraffin sections using the TUNEL method. Apoptosis was quantified by counting the positively stained cell nuclei in transverse sections of embryos. RESULTS: In day 12 control embryos the number of apoptotic nuclei in both lateral ridges of the foregut was high (15.67 +/- 1.38) but relatively low (4.17 +/- 0.80) in Adriamycin-treated embryos (P< .0001). In day 13 Adriamycin-treated embryos, the number of apoptotic nuclei in the region of the upper esophageal pouch was extremely high (23.78.5 +/- 2.20) compared with no detectable apoptotic nuclei in the control embryos. CONCLUSIONS: Apoptosis is required for normal tracheoesophageal embryogenesis and may be an important mechanism to be involved in the embryological development of esophageal atresia and tracheoesophageal fistula.


Assuntos
Apoptose , Esôfago/embriologia , Traqueia/embriologia , Animais , Doxorrubicina/efeitos adversos , Desenvolvimento Embrionário e Fetal , Atresia Esofágica/induzido quimicamente , Feminino , Gravidez , Ratos , Ratos Sprague-Dawley , Fístula Traqueoesofágica/induzido quimicamente
7.
Pediatr Surg Int ; 15(1): 11-6, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-9914346

RESUMO

Adriamycin is teratogenic if given to pregnant rats. A wide range of anomalies involving the gastrointestinal, renal, and cardiovascular systems has been described, similar to the VATER association, yet it is not known if they are identical to the human pattern. The aim of this study was to document the visceral anomalies in rat fetuses exposed to adriamycin and to determine their similarities with the congenital defects in humans with the VATER association. The results revealed a spectrum of very similar anomalies. Furthermore, the characteristics of the tracheo-oesophageal anomalies had a lot of features in common with the human pattern. We conclude that the adriamycin-treated fetal rat is an excellent model for studying the VATER association.


Assuntos
Anormalidades Induzidas por Medicamentos/embriologia , Anormalidades Múltiplas/induzido quimicamente , Modelos Animais de Doenças , Doxorrubicina/toxicidade , Esôfago/anormalidades , Teratogênicos/toxicidade , Traqueia/anormalidades , Anormalidades Múltiplas/embriologia , Animais , Feminino , Humanos , Masculino , Gravidez , Ratos , Ratos Sprague-Dawley
8.
J Reprod Fertil ; 116(2): 335-44, 1999 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10615259

RESUMO

Survival and proliferation of mouse gonocytes was studied using a single cell clonogenic assay in vitro. The effect of growth factors and extracellular matrix on clonogenic development was quantitated. Fundamental requirements for growth of neonatal gonocytes included addition of fetal calf serum and coating culture wells with collagen IV alone or with added fibronectin. After 4-5 days, colonies ranged in size from four to > 128 cells, and some contained very elongated cells indicating migratory behaviour. Soluble stem cell factor did not have any effect on clonogenicity, although STO (subline of SIM mouse fibroblasts) cells, which produce membrane-bound stem cell factor, reduced colony formation from 79 +/- 5.9% to 20 +/- 3.3% without added growth factor. The majority of gonocytes and type A spermatogonia express the c-kit receptor according to in situ hybridization studies. However, the results indicate that the receptor may not be functional in neonatal gonocytes and their immediate progeny. The current assay for gonocytes can be extended to test new growth factors or proliferation-inducing agents directly, as well as to study cell-cell interactions. This assay and long-term propagation of neonatal germ cells will provide the much needed resources to enable greater understanding of the early development of germ cells.


Assuntos
Animais Recém-Nascidos/fisiologia , Espermatozoides/citologia , Animais , Divisão Celular , Células Cultivadas , Células Clonais , Colágeno , Meios de Cultura , Fibronectinas , Imuno-Histoquímica , Hibridização In Situ , Masculino , Camundongos , Camundongos Endogâmicos ICR , Fator de Crescimento Derivado de Plaquetas , Proteínas Proto-Oncogênicas c-kit/análise , Fator de Células-Tronco
9.
Anat Rec ; 252(2): 271-5, 1998 10.
Artigo em Inglês | MEDLINE | ID: mdl-9776081

RESUMO

A spectrum of tracheo-esophageal anomalies has been described in an adriamycin-treated model with common features to the human pattern. Tracheal agenesis was part of this spectrum. It is a rare congenital anomaly that has not been described in embryos. Virgin timed-pregnant Sprague-Dawley rats were injected with adriamycin i.p. at a dose of 2 mg/Kg on days 6-9 of gestation (plug day = day 0). Fetuses were recovered at term and histologic assessment of tracheo-esophageal anomalies was made. Also, embryos were removed on different gestational days and the embryology of these defects was analysed. Two out of sixty-two fetuses and nine out of 180 embryos were identified with tracheal atresia. Type III tracheal atresia was seen in the full-term fetuses with a tracheo-esophageal fistula arising from the origin of the left main bronchus. Day 13 embryos did not show normal tracheal development; instead, the lung buds developed from the ventral aspect of the foregut which continued to the stomach as a lower esophageal segment. A blind ending pouch was seen on the ventral aspect of the upper part of the foregut. The embryogenesis of tracheal atresia was similar to that of esophageal atresia except that the blind upper foregut pouch developed ventrally rather than dorsally.


Assuntos
Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Atresia Esofágica/embriologia , Traqueia/anormalidades , Fístula Traqueoesofágica/embriologia , Anormalidades Induzidas por Medicamentos/patologia , Anormalidades Múltiplas/patologia , Animais , Antibióticos Antineoplásicos/toxicidade , Modelos Animais de Doenças , Doxorrubicina/toxicidade , Atresia Esofágica/induzido quimicamente , Atresia Esofágica/patologia , Feminino , Humanos , Gravidez , Ratos , Ratos Sprague-Dawley , Especificidade da Espécie , Síndrome , Traqueia/efeitos dos fármacos , Traqueia/patologia , Fístula Traqueoesofágica/induzido quimicamente , Fístula Traqueoesofágica/patologia
10.
J Immunol ; 161(8): 4098-105, 1998 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-9780181

RESUMO

Ets-1 is a transcription factor with restricted expression in lymphocytes, and it has been implicated in the regulation of T cell genes such as TCR alpha, TCR beta, CD4, IL-2, and TNF-alpha. We show in this study that Ets-1 is also expressed in some mast cells constitutively and can be induced in primary mast cells with stimuli that activate mast cells. We also show that Ets-1 plays a role in the regulation of granulocyte-macrophage CSF (GM-CSF), a cytokine expressed by activated mast cells. We have characterized a murine growth factor-independent mast cell line, FMP6-, derived from a factor-dependent cell line, FMP1.6. FMP6- has acquired a distinct connective tissue mast cell-like phenotype, as characterized by the expression of mast cell proteases MMCP-4 and MMCP-6, expression of IL-12, and the down-regulation of IL-4. The parental FMP1.6 cell line displays a mucosal mast cell-like phenotype. FMP6- cells have increased Ets-1 expression and achieve growth-factor independence by the autocrine production of GM-CSF and IL-3. Transient transfection of an Ets-1 expression construct in FMP6- cells results in transactivation of a GM-CSF reporter, while a point mutation in the consensus Ets binding site in the conserved lymphokine element, CLE0, abolishes Ets-1 transactivation. Importantly, antisense Ets-1 demonstrates an ability to repress the activity of the GM-CSF reporter. These data suggest a role for Ets-1 in mast cell growth regulation and activation, and because of the central role of mast cells in inflammatory processes, such as asthma and rheumatoid arthritis, they identify Ets-1 as potentially contributing to the pathophysiology of such diseases.


Assuntos
Fator Estimulador de Colônias de Granulócitos e Macrófagos/biossíntese , Mastócitos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Transdução de Sinais/imunologia , Fatores de Transcrição/metabolismo , Animais , Degranulação Celular/imunologia , Divisão Celular/imunologia , Linhagem Celular , Citocinas/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/imunologia , Mastócitos/citologia , Mastócitos/imunologia , Camundongos , Proteína Proto-Oncogênica c-ets-1 , Proteínas Proto-Oncogênicas/imunologia , Proteínas Proto-Oncogênicas c-ets , Fatores de Transcrição/imunologia
11.
J Pediatr Surg ; 33(1): 58-63, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9473101

RESUMO

BACKGROUND/PURPOSE: The association of esophageal atresia with tracheoesophageal fistula and vertebral anomalies is well known, although the embryology of the combined defects has not yet been analysed. The present study describes the origin and development of esophageal atresia with tracheoesophageal fistula and vertebral anomalies in embryos using a rat model of VATER association produced by Adriamycin administration. RESULTS: The lung buds were seen to develop from the laryngotracheal groove but the trachea failed to grow normally and the foregut overgrowth compensated for this failure. The trachea developed by trachealization of the foregut, which continued as a fistula to the lower esophageal segment. The notochord did not separate from the foregut at the correct time (before day 11 in rat embryos, Carnegie stage 11 in human embryos). Overgrowth of the foregut ventrally and caudally carried with it the attached notochord in the same direction leading to abnormal bending of this structure. CONCLUSION: This irregularity of the notochord may be responsible for abnormal development of the vertebrae.


Assuntos
Anormalidades Múltiplas/embriologia , Atresia Esofágica/embriologia , Coluna Vertebral/anormalidades , Fístula Traqueoesofágica/embriologia , Anormalidades Induzidas por Medicamentos/embriologia , Animais , Doxorrubicina , Feminino , Notocorda/anormalidades , Ratos , Ratos Sprague-Dawley , Síndrome
12.
J Pediatr Surg ; 32(11): 1575-9, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9396529

RESUMO

BACKGROUND: Many patients who have esophageal atresia and tracheoesophageal fistula (EA-TEF) have associated tracheomalacia, which is thought to be one of the reasons for respiratory complications after surgical correction of the abnormality. METHODS: In this study, tracheas from Adriamycin-induced EA-TEF fetal rats were examined histologically and relevant cross-sectional parameters of the tracheas were measured. RESULTS: The tracheal lumen in tracheomalacia was small and irregular, losing its normal "D" shape. In most rats, the cartilaginous ring was broken into two to four segments, making the trachea lose its rigid support. The submucosa was thickened with prominent bulging of its membranous part into the tracheal lumen. The ratio of the inner luminal cross-sectional area to the outer tracheal cross-sectional area in EA-TEF rats was 15.7%, compared with a control ratio of 47.2%. In EA-TEF rats, the length of the cartilaginous ring was significantly shortened (P < .001), but not the length of membranous trachea, thus resulting in a cartilaginous/membranous (C/M) ratio of 1.55:1, markedly lower than that of normal rats (4.34:1, P < .001). The reduction of anterior-posterior diameter of the tracheal lumen was more marked than that of the transverse diameter. CONCLUSIONS: These observations suggest that the trachea in EA-TEF rats has a smaller lumen and is more flaccid than normal, making it prone to airway obstruction. The fact that tracheomalacia developed only in fetuses who had EA-TEF indicates that the factors that result in EA-TEF also cause tracheomalacia.


Assuntos
Atresia Esofágica/patologia , Traqueia/crescimento & desenvolvimento , Doenças da Traqueia/patologia , Fístula Traqueoesofágica/patologia , Obstrução das Vias Respiratórias/patologia , Animais , Modelos Animais de Doenças , Desenvolvimento Embrionário e Fetal , Feminino , Gravidez , Ratos , Ratos Sprague-Dawley , Traqueia/patologia
13.
J Pediatr Surg ; 32(11): 1580-6, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9396530

RESUMO

BACKGROUND: After surgical correction of their esophageal atresia and tracheoesophageal fistula (EA-TEF), many patients exhibit evidence of esophageal dysmotility. Controversy exists as to whether the esophageal motility disorders result from denervation caused by surgery or from an inherent abnormal innervation of the esophagus. METHODS: The present study used an Adriamycin-induced EA-TEF fetal rat model to trace the course and branching of both the vagus and recurrent laryngeal nerves. Abnormalities observed in EA-TEF rat fetuses include: (1) fewer branches from both recurrent laryngeal nerves; (2) deviation of the left vagus from its normal course below the aorta, passing behind the fistula to approach and join with the right vagus to form a single nerve trunk on the right side of the esophagus; (3) relatively few branches from the single vagal nerve trunk (composed of fibers of the left and the right vagus) on the surface of the lower esophagus. CONCLUSIONS: Fetuses affected by EA-TEF have inherent abnormalities in the course and branching pattern of the vagus nerves as they descend through the thorax, culminating in a deficient extrinsic nerve fiber plexus in the lower esophagus. These observations may account for the esophageal motility disorders seen in patients who have EA-TEF even before surgical intervention.


Assuntos
Atresia Esofágica/patologia , Transtornos da Motilidade Esofágica/etiologia , Esôfago/inervação , Nervo Laríngeo Recorrente/anormalidades , Nervo Vago/anormalidades , Animais , Modelos Animais de Doenças , Desenvolvimento Embrionário e Fetal , Atresia Esofágica/cirurgia , Feminino , Gravidez , Ratos , Ratos Sprague-Dawley
14.
Anat Rec ; 249(2): 240-8, 1997 10.
Artigo em Inglês | MEDLINE | ID: mdl-9335470

RESUMO

BACKGROUND: The embryology of tracheo-esophageal anomalies is controversial. The development of an adriamycin-treated animal model has enabled improved understanding of the embryogenesis of these anomalies. Using this model, we aimed to describe the events leading to esophageal atresia and tracheo-esophageal fistula. METHODS: Timed-pregnant Sprague-Dawley rats were injected daily with adriamycin intraperitoneally at a dose of 2 mg/Kg on days 6-9 of gestation. Histological sections were prepared from 96 experimental and 34 control rat embryos at 11-14 days gestation (plug day = day 0). RESULTS: The tracheal bud failed to develop normally from the foregut, leaving the foregut to give origin to both bronchi and differentiate into the respiratory system, and then continue as a fistula to the lower esophageal segment. Dorsal pouching of the proximal foregut, which is seen clearly on day 13, is responsible for the development of the upper esophageal segment. CONCLUSIONS: We conclude that failure of the tracheal bud to develop normally from the primitive foregut is the main event which leads to the tracheo-esophageal anomalies. As the proximal part of the primitive foregut develops primarily into a trachea rather than an esophagus, the anomaly of the esophagus could be described as agenesis instead of atresia.


Assuntos
Atresia Esofágica/embriologia , Doenças do Esôfago/embriologia , Fístula Traqueoesofágica/embriologia , Animais , Antibióticos Antineoplásicos/toxicidade , Modelos Animais de Doenças , Doxorrubicina/toxicidade , Desenvolvimento Embrionário e Fetal/efeitos dos fármacos , Atresia Esofágica/induzido quimicamente , Doenças do Esôfago/induzido quimicamente , Feminino , Gravidez , Ratos , Ratos Sprague-Dawley , Fístula Traqueoesofágica/induzido quimicamente
15.
J Urol ; 157(5): 1889-91, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-9112556

RESUMO

PURPOSE: Recently evidence has been accumulating that some undescended testes present later in childhood after apparent normalcy in infancy. These ascending testes appear to explain why a significant number of orchiopexies are performed later in childhood despite the recommendation that surgery for cryptorchidism be performed in infancy. We aimed to determine whether the cause of these ascending testes was persistence of the processus vaginalis. MATERIALS AND METHODS: A total of 25 boys 4 to 13 years old with no history of testicular maldescent at birth underwent transscrotal orchiopexy in a 2-year period. A total of 33 orchiopexies was performed (8 bilateral). The spermatic cord was carefully dissected and operative findings of the nature of the spermatic cord were noted. RESULTS: In all cases dissection within the spermatic cord revealed a similar finding, namely a fibrous string situated deep to the cremasteric muscle and spermatic fasciae. Transection of this string allowed adequate elongation of the vas deferens and gonadal vessels to permit scrotal placement of the testis. Histological examination revealed characteristic processus vaginalis tissue in which the peritoneal derived mesothelial lining cells were present within a partially obliterated processus vaginalis. CONCLUSIONS: Cryptorchidism presenting later in childhood may be an acquired abnormality caused by failure of natural growth of the spermatic cord when the processus vaginalis leaves a fibrous remnant, which prevents normal elongation. These observations suggest that the ascending testis is acquired postnatally and the cause may be related to inguinal hernia.


Assuntos
Criptorquidismo/etiologia , Cordão Espermático/anormalidades , Adolescente , Fatores Etários , Criança , Pré-Escolar , Criptorquidismo/patologia , Criptorquidismo/cirurgia , Humanos , Masculino , Cordão Espermático/patologia
17.
J Pediatr Surg ; 32(1): 12-4, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9021557

RESUMO

A histopathologic study of tracheoesophageal anomalies was conducted on an Adriamycin-treated animal model to determine how closely it resembles the human pattern. Adriamycin was administered (2 mg/kg body weight) to timed-pregnant rats on days 6 through 9 of gestation. The fetuses were recovered at term, dissected and prepared for histological studies. Dissection showed a similar range of variants of tracheoesophageal anomalies as seen in humans. Esophageal atresia with distal tracheoesophageal fistula was by far the most common type. Other varieties were seen such as esophageal atresia without a fistula, tracheal atresia and hypoplastic esophagus with atrophic mucosa, and muscle coat. Serial sectioning of the distal segment showed tracheobronchial elements extending to a variable distance from the origin of the fistula.


Assuntos
Atresia Esofágica/patologia , Fístula Traqueoesofágica/patologia , Anormalidades Induzidas por Medicamentos , Animais , Atrofia , Modelos Animais de Doenças , Doxorrubicina/administração & dosagem , Doxorrubicina/efeitos adversos , Epitélio/patologia , Atresia Esofágica/induzido quimicamente , Esôfago/anormalidades , Esôfago/patologia , Feminino , Idade Gestacional , Humanos , Injeções Intraperitoneais , Masculino , Mucosa/patologia , Músculo Liso/patologia , Gravidez , Ratos , Ratos Sprague-Dawley , Teratogênicos , Traqueia/anormalidades , Fístula Traqueoesofágica/induzido quimicamente
18.
J Pediatr Surg ; 32(1): 15-7, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9021558

RESUMO

Calcitonin gene-related peptide (CGRP) receptors are located in the cremaster muscle of the gubernaculum of rats, and causes gubernacular contraction in vitro, suggesting that CGRP plays an important role in testicular descent. It has been postulated that CGRP released from the genitofemoral nerve acts as a "chemoattractant" for gubernacular migration to the scrotum. The aim of this study is to investigate whether the gubernacular cells of rats exhibit a chemotactic response to CGRP in vitro. Chemotaxis of gubernacular cells from Sprague-Dawley rats (1 to 6 days old) was measured using blind-well chambers. The migration of cells, which passed from the upper to the lower compartment through a polycarbonate filter, were counted using microscopy. The lower compartment included 10(-11), 10(-10), 10(-9), and 10(-8) M CGRP or phosphate buffered saline (PBS) as control. The chemotactic index (CI) was defined as the ratio of migration toward CGRP versus PBS as control. There was no significant migration even at varying CGRP concentrations. Isolated rat gubernacular cells therefore did not exhibit a chemotactic response to CGRP and the role CGRP plays in testicular descent still remains unclear. This result does not exclude the possibility that the gubernaculum responds to CGRP as a whole organ rather than as individual cells.


Assuntos
Peptídeo Relacionado com Gene de Calcitonina/farmacologia , Fatores Quimiotáticos/farmacologia , Ligamentos/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Peptídeo Relacionado com Gene de Calcitonina/metabolismo , Contagem de Células , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Fatores Quimiotáticos/metabolismo , Quimiotaxia , Cultura em Câmaras de Difusão , Epididimo/citologia , Epididimo/efeitos dos fármacos , Epididimo/fisiologia , Células Epiteliais , Epitélio/efeitos dos fármacos , Ligamentos/citologia , Ligamentos/fisiologia , Plexo Lombossacral/metabolismo , Masculino , Membranas Artificiais , Mesoderma/citologia , Mesoderma/efeitos dos fármacos , Músculo Esquelético/citologia , Músculo Esquelético/efeitos dos fármacos , Cimento de Policarboxilato , Ratos , Ratos Sprague-Dawley , Escroto/anatomia & histologia , Testículo/citologia , Testículo/inervação , Testículo/fisiologia
19.
Pediatr Surg Int ; 12(8): 556-64, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9354725

RESUMO

Associated congenital anomalies have emerged as the most significant prognostic factor in babies born with oesophageal atresia and/or tracheo-oesophageal fistula (OA-TOF). The most frequently encountered groups of anomalies are cardiovascular (CV) and gastrointestinal, the former being more significant from a prognostic point of view. Some, such as a right-sided aortic arch (RAA), vascular ring, or major heart defects, may alter the timing and surgical approach for the repair of OA-TOF or adversely affect the prognosis. The rat fetal OA model induced by adriamycin (Adr) has been described previously. In the present experiments, information was sought regarding the incidence and type of CV abnormalities in fetal rats obtained from Adr-treated dams. OA-TOF was induced in 24 of 36 fetal rats from Adr-treated dams. DV abnormalities were found in 18 (75%) OA-TOF fetuses and 10 (83%) Adr-treated fetuses without OA-TOF. The difference was not significant (P >0.05). The most frequently found anomalies were ventricular and atrial septal defects. A RAA was present in 8/36 fetuses and a double aortic arch in 2/36. A patent ductus arteriosus was present in all treated fetuses compared with two-thirds of controls. The findings in the present study emphasise the importance of CV anomalies in association with OA, and reinforce the value of the Adr-induced rat fetal OA model by adding to our knowledge of the basic embryogenesis of both OA and CV anomalies.


Assuntos
Anormalidades Cardiovasculares , Atresia Esofágica/complicações , Cardiopatias Congênitas/complicações , Fístula Traqueoesofágica/complicações , Anormalidades Múltiplas/patologia , Animais , Antibióticos Antineoplásicos/toxicidade , Modelos Animais de Doenças , Doxorrubicina/toxicidade , Atresia Esofágica/induzido quimicamente , Atresia Esofágica/patologia , Feminino , Cardiopatias Congênitas/patologia , Gravidez , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Fístula Traqueoesofágica/induzido quimicamente , Fístula Traqueoesofágica/patologia
20.
Int J Oncol ; 10(5): 933-8, 1997 May.
Artigo em Inglês | MEDLINE | ID: mdl-21533466

RESUMO

Interferons (IFNs) are naturally occurring cytokines which have pleiotropic actions including regulation of cell growth and differentiation, important for control of tumour growth and development. In this study we investigated the association between the presence of IFN genes in NSCLC cell lines, receptor expression and function, and sensitivity to IFNs. Some of the NSCLC lines had partial or complete IFN gene deletion but others contained all genes. However, all NSCLC lines were resistant to the antiproliferative effects of IFN alpha 2 and IFN beta ser. While the lack of sensitivity to IFNs did not appear to be associated with the presence of IFN genes, numbers of receptors or with low binding affinities it did correlate with abnormal regulation of receptor expression. When analyzed by Northern blotting it was notable that IFNA receptor expression on a sensitive cell line, Daudi, was upregulated following IFN exposure however, in the insensitive NSCLC lines IFN mediated upregulation of receptors did not occur. This defect in the regulation of receptor expression in NSCLC lines could contribute to the insensitivity of the antiproliferative effects of IFN's and thus potentiate tumour development or progression.

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