RESUMO
Since transglutaminases create covalent gamma-glutamyl-epsilon-lysine cross-links between extracellular matrix proteins they are prime candidates for stabilizing tissue during wound healing. Therefore, we studied the temporo-spatial expression of transglutaminase activity in skin regenerating from cultured epithelial autografts in severely burned children by the specific incorporation of monodansylcadaverine into cryostat sections from skin biopsies obtained between 5 d to 17 mo after grafting. The dansyl label was subsequently immunolocalized in the epidermis, dermal connective tissue, and along the basement membrane. Incubation of cryosections of normal and regenerating skin with purified tissue transglutaminase confirmed the dermo-epidermal junction and the papillary dermis as targets for this enzyme and revealed that in regenerating skin transamidation of the basement membrane zone was completed only 4-5 mo after grafting. Immunoelectron microscopy revealed that three distinct regions on the central portion of anchoring fibrils were positive for monodansylcadaverine in normal skin which were negative during the initial phase of de novo formation of anchoring fibrils in regenerating skin. Biochemically, we identified collagen VII as potential substrate for tissue transglutaminase. Thus, tissue transglutaminase appears to play an important role not only in cross-linking of the papillary dermis but also of the dermo-epidermal junction in particular.
Assuntos
Adesão Celular/fisiologia , Matriz Extracelular/fisiologia , Regeneração , Fenômenos Fisiológicos da Pele , Transglutaminases/fisiologia , Adolescente , Sequência de Aminoácidos , Queimaduras/cirurgia , Criança , Pré-Escolar , Colágeno/metabolismo , Reagentes de Ligações Cruzadas , Epiderme/fisiologia , Matriz Extracelular/ultraestrutura , Feminino , Humanos , Queratinócitos/transplante , Queratinócitos/ultraestrutura , Masculino , Microscopia Imunoeletrônica , Modelos Biológicos , Dados de Sequência Molecular , Pele/ultraestrutura , Transglutaminases/imunologia , Transglutaminases/isolamento & purificação , Cicatrização/fisiologiaRESUMO
Boys with hypospadias can suffer from specific psychological stress as a result of genital surgery and a cosmetically and/or functionally impaired penis. During recent decades intensive efforts have been made to improve the surgical techniques; yet the psychosocial and psychosexual development of children and adolescents after hypospadias surgery has only rarely been investigated. While the results of the few studies are altogether very contradictory, they also indicate that hypospadias patients suffer from specific problems like a negative perception of genital appearance. Therefore, they should be offered long-term follow-ups and psychosocial support until they reach young adulthood. For future research, it is necessary to systematically investigate the boys' quality of life and development in methodologically sound studies.
Assuntos
Hipospadia/cirurgia , Desenvolvimento Psicossexual , Ajustamento Social , Adolescente , Assistência ao Convalescente/psicologia , Fatores Etários , Imagem Corporal , Criança , Pré-Escolar , Humanos , Hipospadia/psicologia , Masculino , Equipe de Assistência ao Paciente , Complicações Pós-Operatórias/psicologia , Qualidade de Vida/psicologiaRESUMO
The temporo-spatial expression of fibrillin and elastin in skin regenerating from autologous keratinocyte grafts was studied in three burned children. Skin biopsies taken between 5 days and 17 months after grafting were investigated by conventional immunofluorescence, confocal laser scanning, and electron microscopy. Fibrillin, the major component of 10-12nm microfibrils, appeared 5 days after grafting in a band-like fashion similar to collagen VII at the prospective basement membrane, and the formed the characteristic microfibrillar candelabra at the dermo-epidermal junction by fusion of several fine microfibrils to communicating microfibrils projecting downward into the reticular layer of the neodermis. Four to five months after grafting, several communicating microfibrils were connected to a web of horizontally undulating microfibrils of the neodermis which had developed independently. Elastin was first identified in the deeper neodermis 1 month after grafting as granular aggregates and 4 months after grafting on fibrillar structures and surrounding capillaries of the upper neodermis. Association of elastin with microfibrils in the papillary dermis was not detectable before month 17. Our findings suggest that the cutaneous microfibrillar apparatus develops simultaneously at both the dermo-epidermal junction and the reticular dermis and is a prerequisite for elastic fiber formation. In addition, it might be a driving force for the formation of the papilla-rete ridge pattern.
Assuntos
Elastina/análise , Queratinócitos/transplante , Proteínas dos Microfilamentos/análise , Regeneração , Fenômenos Fisiológicos da Pele , Adolescente , Células Cultivadas , Criança , Pré-Escolar , Feminino , Fibrilinas , Humanos , Masculino , Microscopia Eletrônica , Morfogênese , Pele/química , Pele/ultraestrutura , Transplante AutólogoRESUMO
BACKGROUND: Cultured epithelial autografts are regularly used in burn patients, but they have not been tested in patients undergoing reconstructive surgery. The aim of this study was to analyze and compare the efficacy of cultured grafts in both burn and reconstructive surgery patients. METHODS: In six children with severe and massive burns, full-thickness areas were grafted with cultured grafts. In another six children with hypertrophic or hyperpigmented scars, or both, cultured grafts were used to cover defects resulting from scar excision or deep dermabrasion. RESULTS: In burn surgery the final cover rate averaged 60% (range, 0% to 100%). The functional and cosmetic results were good and at least equivalent to results after conventional grafting. Fragility, infection, and, in particular, mechanical instability of cultured grafts during the first weeks after transplantation were the main problems encountered. In reconstructive surgery the final cover rate was 100% in all patients. The functional and cosmetic results were very good and considered better than those obtained by using conventional grafting techniques. No major management problems were encountered. CONCLUSIONS: In massively burned children, cultured epithelial autografts represent an effective additional and potentially lifesaving method to conventional grafting. Questions remain regarding the use of this technique to treat less severe burns. For resurfacing-type scar revisions, cultured epithelial autografts yield excellent results that appear to be superior to those of conventional techniques.
Assuntos
Queimaduras/cirurgia , Cicatriz/cirurgia , Transplante de Pele , Adolescente , Células Cultivadas , Criança , Pré-Escolar , Epitélio/transplante , Feminino , Humanos , Masculino , Transplante AutólogoRESUMO
Laparoscopic surgery with intraperitoneal insufflation is associated with acute oliguria. Although in healthy patients, this impairment is transient and without any apparent sequelae, as the scope of laparoscopic surgery expands, subtle renal injury may become clinically significant, particularly when applications expand to patients with reduced baseline renal function. We have investigated the changes in renal function during and after pneumoperitoneum in animals with reduced renal mass to identify both acute alterations and long-term impairments, if any. Twelve swine underwent surgical reduction in renal mass to produce chronic renal insufficiency. Glomerular filtration rate (GFR) was determined by inulin clearance for each animal before and after ablation to establish the degree of renal impairment (mean 22%; range 18%-31% of normal). The animals were followed during a stepwise insufflation as a study of pneumoperitoneum-induced changes in chronic renal failure. Urine output declined dramatically (-80% at 20 mm Hg), the GFR fell (-63% at 20 mm Hg), and renal blood flow declined (mean -12%; range -9% to -19%) over the course of the test. These values did not return to baseline during a 90-minute observation period after release of the pneumoperitoneum. Acute renal failure occurred despite aggressive hydration with maintenance of central venous pressure and only modest changes in cardiac output. The animals were exposed to a 6-hour CO2 pneumoperitoneum to 20 mm Hg to model the insult of complex laparoscopy. This exposure resulted in elevation of the amount of N-methyl-beta-D-glucosaminidase being shed into the urine in addition to the previously indicated impairments. The animals were allowed to recover for 1 week, and then GFR was again measured. The GFR returned to the preexposure chronic renal failure levels for both the group as a whole and individual animals. The magnitude and duration of the alteration in urine output, GFR, and renal blood flow suggest that regulatory mechanisms rather than simple mechanical forces are involved in the acute changes. No long-term impact on renal function from the acute renal injury was identified, even in animals with existing renal insufficiency.
Assuntos
Rim/fisiopatologia , Pneumoperitônio/fisiopatologia , Abdome/fisiopatologia , Acetilglucosaminidase/urina , Animais , Diurese/fisiologia , Feminino , Taxa de Filtração Glomerular/fisiologia , Pressão , Valores de Referência , Fluxo Sanguíneo Regional/fisiologia , Artéria Renal/fisiopatologia , Suínos , Fatores de TempoRESUMO
This is a report on 31 children with operated extradural hematoma. The aim of the study was to elucidate the characteristics of extradural hematoma in childhood and the different clinical pattern and outcome compared to adults. For that reason the charts of the patients seen at the Department of Surgery of the Children's University Hospital Zurich between 1972 and 1990 have been revised. Follow-up criteria were recorded according to the Glasgow Outcome Scale. Most hematomas have been provoked by minor injuries and almost all children presented with at least one typical clinical sign. Associated intracranial injuries have been found in four patients, while two were polytraumatised. 30 of the 31 patients survived. One patient died of malignant brain edema. The mean range of follow-up was seven years. 28 patients had a "good recovery", "moderate disability" and "severe disability" was found in a patient one each. Our results demonstrate that the long-term outcome in children with extradural hematoma is far better than in adults regarding survival as well as quality of life. The causes may be minor traumas with fewer associated lesions and presentation with typical clinical findings and therefore early diagnosis and treatment.
Assuntos
Hematoma Subdural/cirurgia , Adolescente , Dano Encefálico Crônico/etiologia , Criança , Pré-Escolar , Feminino , Seguimentos , Escala de Coma de Glasgow , Hematoma Subdural/complicações , Hematoma Subdural/diagnóstico , Humanos , Lactente , PrognósticoRESUMO
Between 1982 and 1992, 22 patients were treated with colonic strictures in the course of necrotizing enterocolitis (NEC). Fourteen newborns in whom a primary enterostomy and, when necessary, resection of necrotic bowel was performed developed strictures in the diverted colon. The strictures were detected by colon contrast enema study performed on average 3 months after the first intervention. Eight additional children suffered from an ileus due to primary strictures after conservatively treated NEC, which was surgically managed by enterostomy. Closure of the enterostomy and resection of the stenotic part of the colon was performed thereafter in all 22 children as a single stage procedure. There was no insufficiency of the anastomosis nor any late stricture at follow-up 2.7 years after NEC in our patients. It is concluded therefore that reanastomosis of the enterostomy and resection of an intestinal stricture can be performed as a single stage procedure without any risk after an interval of 3 months between onset of acute NEC and reevaluation. During this interval, a close monitoring and an appropriate management of adequate supplement of electrolytes and bicarbonates is necessary. Most of our babies could be nursed at home and showed a good weight gain during this period, despite the enterostomy.
Assuntos
Colo/patologia , Colo/cirurgia , Enterocolite Pseudomembranosa/fisiopatologia , Enterocolite Pseudomembranosa/cirurgia , Enterostomia , Doenças do Prematuro/fisiopatologia , Doenças do Prematuro/cirurgia , Anastomose Cirúrgica , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Enterostomia/efeitos adversos , Feminino , Seguimentos , Humanos , Fenômenos Fisiológicos da Nutrição do Lactente , Recém-Nascido , Recém-Nascido Prematuro , Obstrução Intestinal/etiologia , Obstrução Intestinal/cirurgia , Masculino , Complicações Pós-Operatórias , Reoperação , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo , Resultado do TratamentoRESUMO
OBJECTIVE: The aim of the study was to evaluate health-related quality of life (HRQoL) of men with a corrected hypospadias in comparison to circumcised controls. Furthermore, determinants of HRQoL were examined. PATIENTS AND METHODS: In a cross-sectional study, HRQoL of 45 men with corrected hypospadias (mean age: 26.2 years +/- 5.1) was compared with a control group of 46 circumcised men (mean age: 25.5 years +/- 4.9). Participants answered three questionnaires: The Medical Outcomes Study Short Form-36 item questionnaire (SF-36), the International Index of Erectile Function (IIEF), and the Penile Perception Score (PPS). RESULTS: Physical and mental dimensions of HRQoL were not impaired among men with corrected hypospadias if compared to circumcised men. Neither socio-demographic and medical variables nor erectile function (EF) predicted HRQoL. However, a negative genital self-perception (PPS) and a lower orgasmic function (OF) were risk factors for an impaired mental HRQoL. CONCLUSIONS: Our data suggest that the HRQoL of adult hypospadias patients is comparable to that of circumcised men. However, patients should be supported in developing a positive genital self-perception, because poor genital self-perception correlated with an impaired mental HRQoL. Since studies with non-operated men suggest that some adapt well to their penile condition, further studies should also include non-operated hypospadias.
Assuntos
Hipospadia/psicologia , Hipospadia/cirurgia , Qualidade de Vida , Adulto , Circuncisão Masculina , Estudos Transversais , Ejaculação , Disfunção Erétil/epidemiologia , Indicadores Básicos de Saúde , Humanos , Hipospadia/epidemiologia , Masculino , Qualidade de Vida/psicologia , Autoimagem , Classe Social , Adulto JovemRESUMO
OBJECTIVE: To assess whether repairing hypospadias before or after 18 months affects psychological adjustment, health-related quality of life (HRQoL) and surgical outcome. PATIENTS AND METHODS: Seventy-seven boys aged 6-17 years were assigned to one of two groups, according to whether they had a hypospadias repair before or after the age of 18 months. The surgical outcome was assessed using the pediatric penile perception score by non-involved urologists. A psychologist interviewed the patients to assess HRQoL and gender-role behavior. The child's psychological adjustment was assessed with a questionnaire for parents. RESULTS: The surgical outcome and complication rate were not significantly different between groups. A covariance analysis of HRQoL, gender-role behavior and psychological adjustment as a function of age at the last operation with current age as covariant was performed, but differences did not reach significance. CONCLUSION: This study does not provide evidence to support recommendations concerning the ideal age for hypospadias repair. In the absence of evidence of a benefit of early surgery, anesthesia-related risk factors must be considered when operating in very early infancy. Large, prospective studies, measuring surgical and psychological outcome with similar instruments to those presented may reveal whether there is a true ideal age for hypospadias surgery.
Assuntos
Hipospadia/cirurgia , Adolescente , Fatores Etários , Criança , Humanos , Hipospadia/psicologia , Lactente , Masculino , Projetos Piloto , Resultado do Tratamento , Procedimentos Cirúrgicos Urológicos Masculinos/normasRESUMO
OBJECTIVE: A significant epidural haematoma (EDH) is generally treated by craniotomy and evacuation. This is a report of conservative management following an EDH on computerized tomography (CT) in a paediatric population. The authors examined whether conservative treatment of radiologically significant EDH is a successful and safe therapeutic option. METHODS: Retrospective data were collected from charts of patients with conservatively treated EDH in the Department of Surgery of the University Children's Hospital Zurich between September 1993 and January 2004. Included were patients without focal neurological deficits, with a Glasgow Coma Scale (GCS) of 15 and an initial CT demonstrating an EDH with a minimal thickness of 1 cm. Mild clinical symptoms of raised intracranial pressure such as headache, nausea or vomiting were treated symptomatically. Follow-up included a standardized interview, a neuropaediatric examination and CT. RESULTS: Thirteen children with EDH had successful conservative management. Only one 12-year-old female patient with a delayed diagnosed frontal EDH required surgical intervention 24 h after admission and 5 days after the accident. Clinical follow-up showed patients without neurological deficits, a Glasgow Outcome Scale of 5 and no post-traumatic sequelae over an average of 4 4/12 years (range 4 months to 10 4/12 years). Follow-up CT showed complete resolution of the EDH within 2 to 3 months. CONCLUSIONS: Our results demonstrate that significant EDH can be treated non-operatively in neurologically normal children. We recommend that such treatment be performed in specialised paediatric centres under adequate neurological observation since prompt emergency operation in case of neurological deterioration should be provided.
Assuntos
Dano Encefálico Crônico/prevenção & controle , Hematoma Epidural Craniano/cirurgia , Adolescente , Dano Encefálico Crônico/etiologia , Criança , Pré-Escolar , Feminino , Seguimentos , Escala de Coma de Glasgow , Hematoma Epidural Craniano/complicações , Hematoma Epidural Craniano/diagnóstico por imagem , Humanos , Tempo de Internação , Masculino , Recuperação de Função Fisiológica , Estudos Retrospectivos , Índice de Gravidade de Doença , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
PURPOSE: Congenital hydronephrosis is more common in male individuals. We investigate whether an alteration in fetal bladder function induced by premature urachal closure contributes to fetal hydronephrosis, consequently explaining this male predominance. MATERIALS AND METHODS: The urachus was clipped in 8 male and 4 female ovine fetuses at 95 days of gestation (term 140 days). Subjects were sacrificed, and the urinary tract was assessed at 109 and 116 days of gestation in 3 and 1 male fetuses, respectively, and at term in 4 male and 4 female lambs. RESULTS: At 109 and 116 days of gestation 3 of the 4 male fetuses had upper tract dilatation. At term no female but 4 male lambs had hydroureteronephrosis, including some with marked pelvic dilatation and parenchymal thinning. At term mean bladder weight in the male animals with urachal clipping was 5.28 gm. (range 3.5 to 8.2), which was significantly greater than normal (p = 0.02). Bladder weight at term in the female lambs with urachal clipping was not different from normal values. Histological evaluation of the kidneys in the male lambs revealed cortical thinning and loss of medullary tissue, while the overall renal architecture was well preserved. CONCLUSIONS: Our observations indicate that normal ovine fetal urinary tract function and drainage depend on urachal function and the timing of urachal closure. Therefore, fetal hydronephrosis is associated with this alteration in bladder function but it may also be associated with other factors, such as bladder sphincter maturation or prostate development. Our experiment shows that hydroureteronephrosis develops in ovine fetuses when all bladder drainage occurs via the urethra. This condition may be an amplification of the differences in bladder outlet resistance in human fetuses, which may explain the male predominance in the various forms of hydroureteronephrosis.
Assuntos
Doenças Fetais/embriologia , Hidronefrose/embriologia , Úraco/embriologia , Animais , Feminino , Idade Gestacional , Masculino , OvinosRESUMO
Mice infected with live vesicular stomatitis virus (VSV) produced primary antibody responses more efficiently (with doses greater than 10(2) pfu) than those injected with UV-inactivated VSV (greater than 10(6) pfu) or purified VSV glycoprotein G (equivalent to 10(7) pfu) by producing neutralizing antibodies. Very low doses of live VSV (less than 10(2) pfu) failed to prime mice. Normal mouse serum had the capacity to inactivate VSV by heat-labile and immunoglobulin-mediated mechanisms in vitro independently of specifically induced antibodies. Studies using B cell-depleted agammaglobulinaemic mice showed that their serum lacked VSV-neutralizing capacity in vitro and that naturally resistant mice became susceptible to VSV-induced paralytic disease which could be prevented by adoptive transfer of immune but also of normal serum.
Assuntos
Anticorpos Antivirais/fisiologia , Imunidade Inata , Glicoproteínas de Membrana , Vírus da Estomatite Vesicular Indiana/imunologia , Vacinas Virais/imunologia , Animais , Feminino , Humanos , Soros Imunes , Imunoglobulina G/fisiologia , Camundongos , Camundongos Endogâmicos , Testes de Neutralização , Vacinas de Produtos Inativados/imunologia , Proteínas do Envelope Viral/imunologiaRESUMO
We retrospectively reviewed six pediatric cases of medial clavicular injury, i.e., epiphyseal separation (Salter/Harris type I or II injury), diagnosed between 1993 and 1997. The clavicular metaphysis was displaced posteriorly in three cases and anteriorly in three. On conventional radiographic views the diagnosis was initially missed in two of three retrosternal dislocations. A special X-ray projection (described by Heinig) or computed tomography (CT) permitted correct diagnosis. Anterior dislocations were immediately and correctly diagnosed. Closed reduction successfully treated retrosternal displacement in two of the three patients. The third patient needed open reduction and internal fixation. Open reduction and internal fixation had to be performed in all three patients with anterior displacement. Follow-up assessment showed perfect functional results in all cases. Direct visualization during open reduction, which was necessary in four of six cases, yielded clear evidence that the so-called sternoclavicular dislocation in children and young adults is, in fact, a fracture of the medial growth plate with posterior or anterior displacement of the metaphysis.
Assuntos
Epifise Deslocada/diagnóstico por imagem , Luxações Articulares/diagnóstico por imagem , Articulação Esternoclavicular/lesões , Adolescente , Criança , Erros de Diagnóstico , Epifise Deslocada/etiologia , Feminino , Humanos , Luxações Articulares/complicações , Luxações Articulares/terapia , Masculino , Articulação Esternoclavicular/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
PURPOSE: Prenatal diagnosis allows the early detection of vesicoureteral reflux in an increasing number of newborns, some of whom are born with impaired kidney function. This situation challenges our current understanding of the pathophysiology, natural history and, therefore, treatment of reflux. We created a fetal sheep model of vesicoureteral reflux to study the mechanisms of fetal reflux nephropathy. MATERIALS AND METHODS: Vesicoureteral reflux was induced in fetal sheep at 95 days of gestation (term 140 days) by open bladder incision of the intravesical ureteral tunnel. All animals underwent urachal ligation and in female subjects mild bladder outlet obstruction was created with a gold ring. RESULTS: At term reflux was detected in 18 of 28 renal units by filling cystography. Refluxing kidneys were hydronephrotic and larger than normal. At term mean kidney weight was 21.1 gm. (range 12.2 to 35.0) in male subjects with reflux compared to 8.5 gm. (range 6.5 to 11.3) in normal male subjects (p <0.001) and 11.5 gm. (range 8.5 to 15.8) in male subjects with urachal ligation only (p = 0.035). In female subjects there was no change in renal weight. Renal histology revealed a thin, structurally normal cortex with small subcortical cysts and a hypoplastic medulla with mesenchymal tissue replacing normal ducts. Total mean renal collagen content was significantly increased to 51.7 mg. (range 35 to 81) in the refluxing kidneys of male animals, while it was 23.8 mg. (range 12.1 to 38.4) in normal male animals (p = 0.03). The fractional excretion of sodium was elevated in refluxing kidneys based on sodium-to-creatinine ratios in bladder urine. CONCLUSIONS: In a novel model of fetal vesicoureteral reflux we showed that prenatal reflux nephropathy is characterized by altered renal growth regulation, structural maldevelopment without overt dysplasia, excess matrix deposition and impaired excretory function.
Assuntos
Doenças Fetais/etiologia , Rim/patologia , Bexiga Urinária/fisiopatologia , Refluxo Vesicoureteral/complicações , Refluxo Vesicoureteral/etiologia , Animais , Feminino , Fibrose/etiologia , Masculino , OvinosRESUMO
A murine model of virally induced acquired immunodeficiency was analyzed in mice. The effect of systemic infection with various isolates of lymphocytic choriomeningitis virus (LCMV) on the capacity of mice to mount a T cell-independent IgM and a T cell-dependent IgG neutralizing antibody response against a subsequent infection with vesicular stomatitis virus (VSV) was analyzed. DBA/2 mice infected with the LCMV-WE isolate were impaired in their IgM and IgG responses to VSV. Immune suppression was not caused by interferons inhibiting proper VSV antigen expression, since responses to inactivated VSV were also suppressed. The higher the dose of the LCMV and the lower the dose of the challenging VSV infection the more drastic was the apparent lack of immune responsiveness and the longer it lasted. Kinetics of induction of suppression of the T cell-independent IgM responses closely followed that of a normal cytotoxic T cell response to LCMV-WE, starting on day 6 and reaching maximal levels by day 8 to 10. The T cell-dependent IgG response to VSV was suppressed with a kinetics that was shifted by about 6 days when compared with suppression of IgM responses, i.e. LCMV infection on the same day or before (but not after) VSV infection led to suppression of IgG responses that are usually first detected by day 6-7 after initiation of the VSV infection. Severity and duration of immunosuppressiveness depended upon the LCMV isolate and the mouse strain used: LCMV-WE and LCMV-Docile were most, whereas LCMV-Armstrong was in general least immunosuppressive. Antibody responses to VSV-NJ seemed to be more subject to LCMV-induced immune suppression than VSV-IND-specific responses. Mouse strains differed considerably with respect to extent of suppression, dependent upon both major histocompatibility genes (MHC) and non-MHC genes. DBA and Swiss type mice were generally more susceptible than C57BL and CBA mice, and H-2q and H-2k seemed to be more susceptible than H-2b or H-2d mice. Mice infected with LCMV-WE showed signs of acquired immunodeficiency diseases since they were more susceptible to superinfection with VSV and developed paralytic disease and tended to die from VSV infection. Since LCMV is basically a noncytopathic virus, this murine model of virally induced immune suppression may serve to analyze immune pathogenesis of virus-induced acquired immunodeficiency.
Assuntos
Tolerância Imunológica , Síndromes de Imunodeficiência/microbiologia , Coriomeningite Linfocítica/imunologia , Animais , Anticorpos Antivirais/biossíntese , Imunoglobulina G/biossíntese , Imunoglobulina M/biossíntese , Síndromes de Imunodeficiência/imunologia , Memória Imunológica , Interferons/imunologia , Vírus da Coriomeningite Linfocítica/imunologia , Camundongos , Camundongos Endogâmicos , Fatores de Tempo , Vírus da Estomatite Vesicular Indiana/imunologiaRESUMO
PURPOSE: To evaluate contrast agent-enhanced harmonic ultrasonographic (US) imaging and Doppler hemodynamics during acute urinary obstruction. MATERIALS AND METHODS: In 12 piglets, the distal ureter was obstructed for 60 minutes, followed by intravenous injection of furosemide. In six piglets, ureteral pressure was further elevated to mean arterial pressure, and in six other piglets ureteral obstruction was released. Contrast-enhanced harmonic imaging was performed, and interlobar resistive index (RI) and renal blood flow were determined at baseline and during each experimental condition. A bolus injection curve was constructed by plotting mean pixel intensity versus time, and the area under this normalized curve was compared with renal blood flow values. RESULTS: Ureteral obstruction and high ureteral pressure reduced cortical renal blood flow to 88% and 66%, respectively, of baseline values. Administration of contrast agent resulted in marked homogeneous enhancement of the renal cortex. The area under the curve diminished during ureteral obstruction and correlated well with mean cortical blood flow. RI correlated well with renal perfusion pressure but poorly with changes in renal blood flow. CONCLUSION: Contrast-enhanced harmonic US imaging depicts changes in renal blood flow during acute obstruction. Interlobar RI is a good predictor of renal perfusion pressure but not of changes in renal blood flow.
Assuntos
Aumento da Imagem , Rim/irrigação sanguínea , Ultrassonografia Doppler , Obstrução Ureteral/diagnóstico por imagem , Animais , Velocidade do Fluxo Sanguíneo/fisiologia , Pressão Sanguínea/fisiologia , Meios de Contraste , Fluorocarbonos , Hidronefrose/diagnóstico por imagem , Rim/diagnóstico por imagem , Fluxo Sanguíneo Regional/fisiologia , Suínos , Resistência Vascular/fisiologiaRESUMO
BACKGROUND: To determine whether fetal renal obstruction activates the renal renin-angiotensin system (RAS), an important mediator in normal kidney development and obstructive nephropathy, we used a model of fetal partial bladder outlet obstruction (PBOO). METHODS: Total RNA and protein was extracted from kidney of sheep fetuses with partial bladder outlet obstruction created at 95 days gestation, after 2 (N = 6) and 5 weeks of obstruction (term; N = 6), and from normal fetal sheep at various time points between 60 and 135 days of gestation (total N = 19). Relative levels of mRNA for renin, angiotensinogen, type 1 and 2 angiotensin II (Ang II) receptors (AT-1 and AT-2), and transforming growth factor-beta1 (TGF-beta1) were assessed by semiquantitative reverse transcription-polymerase chain reaction. Expression levels of AT-2 receptor protein were measured by Western blot analysis. RESULTS: Renin mRNA expression was increased (250%) after two weeks of obstruction. In normal fetuses, AT-1 expression was low at 60 to 75 days of gestation and increased toward the end of gestation, whereas AT-2 expression showed a reversed pattern. At 109 days, PBOO caused an increased expression of AT-2 mRNA compared with normals (400%). Correspondingly, AT-2 receptor protein was more abundant in obstructed kidneys. TGF-beta1 mRNA expression was significantly increased in obstructed kidneys at 109 days gestation. CONCLUSIONS: These observations confirm the reciprocal developmental regulation of AT-1 and AT-2 receptors' expression, suggesting their functional role in renal development. Partial bladder outlet obstruction produces specific alterations: increased renin expression and altered balance of receptor subtypes, which may induce altered functional and vascular regulation of the obstructed fetal kidney. TGF-beta1, a mediator of Ang II-induced fibrosis, may play a role in inducing and propagating interstitial fibrosis.
Assuntos
Feto/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Rim/metabolismo , Sistema Renina-Angiotensina/fisiologia , Obstrução do Colo da Bexiga Urinária/fisiopatologia , Animais , Feminino , Rim/embriologia , Gravidez , RNA Mensageiro/análise , Receptor Tipo 1 de Angiotensina , Receptor Tipo 2 de Angiotensina , Receptores de Angiotensina/genética , Renina/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ovinos , Fator de Crescimento Transformador beta/genéticaRESUMO
PURPOSE: We determine whether fetal bladder outlet obstruction induces renal fibrosis, and is associated with an alteration in the regulation of connective tissue degradation and the presence of fibrogenic interstitial cells. MATERIALS AND METHODS: Partial bladder outlet obstruction was surgically induced in 33 fetal sheep at 95 days of gestation. These animals and 24 normal age matched controls were sacrificed at 109, 116 and 135 (term) days of gestation, and the kidneys were rapidly retrieved, drained and weighed. Representative whole kidney samples were snap frozen for assessment of deoxyribonucleic acid, protein and collagen content. Morphometric analysis and alpha-smooth muscle actin immunohistochemistry were performed on histological specimens from formalin fixed kidneys. Tissue extract from fresh kidney specimens were analyzed for metalloproteinase and tissue inhibitor of metalloproteinase activity. Urine samples obtained at the time of sacrifice were analyzed for electrolyte, creatinine and N-acetyl glucosaminidase excretion. RESULTS: All obstructed kidneys were hydronephrotic and larger than age matched controls. Obstructed kidneys at term showed interstitial fibrosis, as measured by increased extracellular matrix volume fraction (45% in male obstructed kidneys versus 2.5% in normal male kidneys, p = 0.0004), increased total collagen content (120 mg./kidney in male obstructed versus 20 mg. in normal male animals, p = 0.016) and collagen/deoxyribonucleic acid content per kidney (2.78 versus 0.53 mg./mg., p = 0.016). Metalloproteinase-1 activity was significantly lower in obstructed kidneys (210 versus 380 U./mg. protein in normal kidneys). Tissue inhibitor of metalloproteinase activity was undetectable in both groups. The presence of an increased population of myofibroblasts often associated with fibrotic processes was seen by alpha-smooth muscle actin staining which was localized to interstitial cells throughout the cortex in obstructed kidneys. CONCLUSIONS: Fetal partial bladder outlet obstruction induces renal interstitial fibrosis as early as 2 weeks after obstruction. A possible mechanism for this process is a shift in proteolytic activity to reduce matrix degradation in obstructed kidneys. These changes might be mediated by the increased number of fibrogenic interstitial cells. The observations suggest several potential approaches to developing an understanding of congenital obstructive uropathy.
Assuntos
Doenças Fetais/metabolismo , Fibroblastos/metabolismo , Rim/patologia , Obstrução Uretral/complicações , Obstrução Uretral/metabolismo , Actinas/biossíntese , Animais , Colágeno/metabolismo , Tecido Conjuntivo/metabolismo , Fibrose , Metaloendopeptidases/metabolismo , Músculo Liso/metabolismo , OvinosRESUMO
PURPOSE: We assessed renal function and urodynamic status in animals with experimental congenital vesicoureteral reflux. MATERIALS AND METHODS: Vesicoureteral reflux was surgically induced in male sheep fetuses at 95 days of gestation. After birth the animals were maintained on antibiotic prophylaxis. At ages 1 week and 6 months reflux was assessed by fluoroscopic voiding cystography. Cystometrography was performed with the animals awake. Serum creatinine, inulin clearance and the excretion of urinary N-acetyl-beta-D-glucosaminidase were measured at ages 1 week, 1 month and 6 months by surveillance urine cultures. Urinary concentrating capacity was assessed by desmopressin testing at ages 1 and 6 months. RESULTS: Nine animals (18 renal units) were born after the induction of reflux. There was no reflux in 2 renal units, while reflux was mild in 2, moderate in 5 and severe in 9. In the 6 animals available for followup at age 6 months only severe reflux persisted. Reflux resolution was associated with normalization of bladder urodynamics. Surveillance urine cultures were negative until age 6 months, when infection developed in 3 of the 6 lambs. In all animals serum creatinine was normal during followup. Glomerular filtration rate in the lambs with reflux was no different from normal at age 1 week but it was significantly less than normal independent of infection at age 6 months (2.7 versus 3.9 ml./kg. per minute, p = 0.002). As an indicator of renal tubular injury the ratio of N-acetyl-beta-D-glucosaminidase-to-creatinine remained significantly higher in animals with reflux than in normal animals from ages 1 week to 6 months (51.0 versus 10.2 IU/mg., p = 0.03). Maximal concentrating ability after desmopressin testing was already less than normal by age 1 month with a maximal increase of 98 versus 435 mOsm./l. in lambs with reflux versus normal lambs (p <0.0001). It was further impaired by age 6 months. Urodynamic evaluation of the animals with reflux revealed decreased bladder compliance at age 1 week with normal voiding pressure. In addition, in those with reflux there was a more pronounced immature voiding pattern with multiple phasic contractions due to sphincteric activity as well as a post-void bladder contraction. CONCLUSIONS: Our model of fetal vesicoureteral reflux induces alterations in renal function that are consistent with clinical observations and marked by altered tubular function but a relatively mild decrease in glomerular filtration. Bladder dynamics are altered, consistent with observations in human neonates with high grade reflux and bladder instability. Whether this represents cause or effect remains unclear. Our model permits focused study of the interaction of these factors in neonatal reflux and may allow the application of more specific therapies, particularly those directed toward mechanisms of renal and bladder dysfunction.