RESUMO
The concentration of radiocarbon, 14C, in the atmosphere depends on its production rate by cosmic rays, and on the intensity of carbon exchange between the atmosphere and other reservoirs, for example the deep oceans. For the Holocene (the past approximately 11,500 years), it has been shown that fluctuations in atmospheric radiocarbon concentrations have been caused mostly by variations in the solar magnetic field. Recent progress in extending the radiocarbon record backwards in time has indicated especially high atmospheric radiocarbon concentrations in the Younger Dryas cold period, between 12,700 and 11,500 years before the present. These high concentrations have been interpreted as a result of a reduced exchange with the deep-ocean reservoir, caused by a drastic weakening of the deep-ocean ventilation. Here we present a high-resolution reconstruction of atmospheric radiocarbon concentrations, derived from annually laminated sediments of two Polish lakes, Lake Gosciaz and Lake Perespilno. These records indicate that the maximum in atmospheric radiocarbon concentrations in the early Younger Dryas was smaller than previously believed, and might have been caused by variations in solar activity. If so, there is no indication that the deep-ocean ventilation in the Younger Dryas was significantly different from today's.
RESUMO
The authors present their own modification of surgical staged repair of large abdominal wall defects (AWD). 21 newborns with gastroschisis (GSCH) and 8 with omphalocele (OC) are presented. In all patients the protruding viscera were placed in a prosthetic sac with a semi-permeable lining. The sac was suspended using a system with active external traction with a force amounting to 30 - 40 % of the baby's weight. All babies tolerated the applied method well. A progressive stretching of the abdominal wall and enlargement of the abdominal cavity enabled the defect to be closed between the second and sixth postoperative day. In comparison to the classic method, the presented modification of staged repair of AWD makes an earlier reduction of the viscera into the abdomen possible and does not seem to be associated with a higher risk of mechanical or infectious complications.
Assuntos
Músculos Abdominais/cirurgia , Procedimentos Cirúrgicos do Sistema Digestório , Gastrosquise/cirurgia , Hérnia Umbilical/cirurgia , Tração/métodos , Humanos , Recém-NascidoRESUMO
UNLABELLED: Uroflowmetry, as the only non-invasive urodynamic means of assessing the function of the lower urinary tract is widely used in children. A possible psychological influence on the results is the reason why uroflowmetry is often repeated in the same patient. OBJECTIVES: The investigation was conducted to compare parameters of repeated uroflowmetry in a single child with the results of single uroflowmetry performed in a group of children. The goal of the study was to evaluate the efficacy of a single uroflow procedure in children. MATERIAL AND METHODS: A single uroflowmetric study was performed in 44 children aged from 9 - 11 years (mean 10 yrs). Out of the group one child was chosen who had 32 successive uroflow attempts. The range and average values of the uroflowmetric parameters were compared in both groups. Pearson's correlation coefficient was used for calculation and for a comparison of the uroflowmetric parameters of both groups (significance level p < 0.05). RESULTS: Average values of the voided volume, maximal and average flow were lower in the 32 attempts of a single child than in the control group (44 attempts). The values of the Pearson's correlation coefficient were ranged from 0.2 to 0.4 for flow/voided volume ratio and from 0.4 to 0.8 for flow time/voided volume ratio in both groups. There were no differences between the values in both groups apart from flow time/voided volume correlation (significance level p < 0.05). CONCLUSION: Repetition of uroflowmetric study does not seem to improve the efficacy of the modality in assessing voiding function in children.
Assuntos
Transtornos Urinários/diagnóstico , Urodinâmica , Criança , Humanos , Reologia , Transtornos Urinários/fisiopatologiaRESUMO
Germline mutations of the p53 gene lead to cell transformation in various tissues. Such a complex cancer phenotype makes it difficult to recognize the carriers of the defective allele. Several studies undertaken to identify high-risk groups found germline p53 mutations in familial cancer aggregations and in patients with multiple tumors. We screened 189 pediatric and 48 adult patients. The high-risk groups comprised 41 patients with a family history of cancer and 35 with multiple neoplasms. Furthermore, 124 tumors were screened for somatic mutations. p53 exons 2 to 11 were analyzed by polymerase chain reaction and single strand conformation polymorphism (PCR-SSCP) followed by direct sequencing of abnormal DNA fragments. No germline p53 mutations were found and somatic mutations were detected in 5 of 59 sarcomas, globally, in 8 of 124 tumors. In conclusion, in Poland, p53 alterations do not seem very important for the predisposition to malignancy and development of sarcomas.
Assuntos
Genes p53 , Testes Genéticos , Mutação em Linhagem Germinativa , Adulto , Criança , Humanos , Síndrome de Li-Fraumeni/genética , Metástase Neoplásica/genética , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Fatores de Risco , Sarcoma/genéticaRESUMO
The authors have observed seven cases of this syndrome, and together with a review of the literature, they discuss the various facets which constitute this disease. Particular attention is paid to the findings in the vessels of the extremities on phlebography and arteriography, and the authors conclude that these examinations are vital in the diagnosis of this syndrome.
Assuntos
Angiomatose/diagnóstico por imagem , Síndrome de Klippel-Trenaunay-Weber/diagnóstico por imagem , Adolescente , Adulto , Angiografia , Fístula Arteriovenosa/complicações , Fístula Arteriovenosa/diagnóstico por imagem , Criança , Pré-Escolar , Feminino , Humanos , Síndrome de Klippel-Trenaunay-Weber/complicações , Perna (Membro)/irrigação sanguínea , Masculino , Varizes/complicações , Varizes/diagnóstico por imagemRESUMO
The long-term effect of dividing the genitofemoral nerve supply to the undescended testis in naturally cryptorchid rats is reported. 20 male Buffalo rats with an undescended right testis, noted at the age of 30 days, were used for the investigation. 20 healthy animals served as controls. The abdominal division of the right genitofemoral nerve was performed in 10 cryptorchid and 10 healthy animals at the age of 40 days. The animals were mated at 150 days of age. Both testes were removed at 180 days of age. In each excised testis the testicular weight and seminiferous tubular diameters were measured, and the maturity of the germinal epithelium was determined using the Johnsen testiscular biopsy score. The experiment showed that in 70% of the nonoperated cryptorchid rats, both testes were affected at the age of 180 days, and 90% of these animals were infertile. In the operated cryptorchid rats, the contralateral descended were not damaged, and 60% of these animals were fertile. The division of the genitofemoral nerve in healthy animals had no effect. The results suggest that neural transmissions might play a role in the damage to the descended testis in unilateral cryptorchidism. This observation requires further investigations.
Assuntos
Criptorquidismo/cirurgia , Testículo/inervação , Animais , Criptorquidismo/fisiopatologia , Fertilidade , Masculino , Métodos , Tamanho do Órgão , Nervos Periféricos/cirurgia , Ratos , Ratos Endogâmicos BUF , Espermatogênese , Testículo/patologiaRESUMO
Both clinical and experimental evidence suggest that fertility is impaired in unilateral cryptorchidism. To investigate the effect of the undescended testis on the contralateral descended gonad, a new experimental model based on natural cryptorchidism in rats was designed. Seventy male Buffalo rats with an undescended right testis noted at the age of 30 days were used. Fifty healthy animals served as a controls. The natural course of cryptorchidism was investigated at the ages of 30, 90, and 180 days. The effects of orchiopexy and orchiectomy performed in cryptorchid animals before and after puberty were evaluated at the age of 180 days. Both nonoperated and operated animals were mated at the age of 150 days in order to estimate their fertility. The animals were killed at 30, 90, and 180 days of life and the testes were removed. In each excised testis testicular weight and seminiferous tubular diameters were measured and the maturity of the germinal epithelium was determined using the Johnsen testicular biopsy score. The experiment demonstrated reduced testicular weight and seminiferous tubular diameters in undescended testis already at 30 days and arrest of spermatogenesis at the spermatocytes stage at 90 and 180 days. There was no significant difference between contralateral descended testes and controls at the age of 30 and 90 days, but at 180 days the degenerative changes were identical with those in the cryptorchid testes. Cryptorchid rats were completely infertile. Both orchiopexy and orchiectomy prevented the damage to the contralateral testis. A significant improvement in size and spermatogenesis was recorded in most cases of the surgically descended testes.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Criptorquidismo/cirurgia , Orquiectomia , Animais , Criptorquidismo/patologia , Fertilidade , Masculino , Tamanho do Órgão , Ratos , Ratos Endogâmicos BUF , Túbulos Seminíferos/patologia , Maturidade Sexual , Fatores de TempoRESUMO
PURPOSE: The aim of this study was to evaluate a natural history of congenital intestinal atresia (IA) in the chick embryo and to assess the type and nature of changes in the intestine at various developmental stages. METHODS: Chick embryos underwent operative induction of IA on the 12th day of incubation. The procedure consisted of electrocoagulation of the mesenteric vessels supplying a 7- to 8-mm intestinal segment. The embryos were subjected to macroscopic examination, histologic and ultrastructural studies of the preatretic and postatretic bowel using the light microscope, scanning, and transmission electron microscopes. All investigations were performed in an experimental group (operated embryos), in a control group, and in a sham-operated group on the 15th, 17th, 19th, and 21st day of incubation. RESULTS: The original technique of an iatrogenic "vascular event" proved to be effective because IA developed in 96% of embryos surviving the procedure. The affected portion of the bowel underwent progressive necrosis, and signs of bowel obstruction could be observed 48 hours after operation. Cord atresia (type II) developed in 81% of embryos. Histologic investigations showed progressive thinning of mucosa, flattening of mucosal folds, and epithelial detachment within the intestine proximal to atresia. There was only mild hypertrophy of the muscular layers. All these pathomorphologic changes were of rapidly progressive nature until the 17th day of incubation. Later, the rate of distension of preatretic bowel and histologic changes were less. Ultrastructural investigation of the proximal bowel showed progressive flattening of the enterocytes associated with their apical bulging, widening of the intercellular spaces, and microvilli atrophy. Surprisingly, at days 19 and 21 of incubation, signs of induction of adaptive mechanisms with partial restoration of near-normal microvilli pattern were observed. CONCLUSIONS: Study of natural history of experimental IA indicates that histologic and ultrastructural lesions of the bowel are of dynamic nature and are not only the effect of pathologic intraluminal pressure.
Assuntos
Atresia Intestinal/patologia , Mucosa Intestinal/patologia , Mucosa Intestinal/ultraestrutura , Animais , Embrião de Galinha , Técnicas de Cultura , Modelos Animais de Doenças , Imuno-Histoquímica , Microscopia Eletrônica de Varredura , Valores de Referência , Sensibilidade e EspecificidadeRESUMO
Retrospective analysis of chemotherapy results of children with nephroblastoma was performed in 220 patients aged from 1 yr to 14 yrs of live in 12 centers. Stage I nephroblastoma was documented in 24.5% but stage II--in 55.3%. Histologically 74.6% cases were diagnosed as medium malignant and 12.7%--high malignant. Therapy results were similar to observed in other centers.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Tumor de Wilms/tratamento farmacológico , Adolescente , Criança , Pré-Escolar , Dactinomicina/administração & dosagem , Humanos , Lactente , Recém-Nascido , Neoplasias Renais/patologia , Estadiamento de Neoplasias , Estudos Retrospectivos , Estatísticas não Paramétricas , Vincristina/administração & dosagem , Tumor de Wilms/patologia , Tumor de Wilms/secundárioRESUMO
Permanent access to the centrally positioned veins is necessary for the treatment of children with malignancy. The Broviac-Hickman's catheters and venous port system fulfill this require. Since January 1992 to February 1998, 276 intravenous life-cath devices were installed. In 7 patients life-threatening complications after catheter implantation occurred, which demanded urgent surgical intervention. The complications appeared in both early and late periods after catheter insertion. Pneumothorax (three children), bleeding to the mediastinum (one patient), fragmentation, disconnection and migration of a separate part of catheter into the right heart (two patients) were observed. The way of treatment and its results were described.
Assuntos
Cateterismo Venoso Central/efeitos adversos , Neoplasias/terapia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos RetrospectivosRESUMO
Seven children treated surgically because of non-rhabdomyosarcomatous soft tissue sarcoma (NRSTS) localized extrameningeally on the head and neck were presented. Three of the patients were operated on haemangiopericytoma, two--fibrosarcoma, one child--neurofibrosarcoma and one--liposarcoma. The pre- and postoperative TNM classification was employed as a staging system. The surgical resectability--R was used to establish tumour margins. Four patients (two with fibrosarcoma and two with haemangiopericytoma) survived free of disease. The influence of the complete surgical resection on the outcome of the head and neck extrameningeal NRSTS was proved.
Assuntos
Neoplasias de Cabeça e Pescoço/cirurgia , Sarcoma/cirurgia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Estadiamento de Neoplasias , Estudos RetrospectivosRESUMO
The authors are presenting 70 cases of acute blood-derived inflammation of bones in children treated in the Clinic of Children's Surgery in the Academy of Medicine in Wroclaw in the last 10 years. Gentamicin balls were used for 21 children including 18 newborns and babies. In 16 cases implantation of gentamicin balls was the only way of local treatment, and in 5 cases it was preceded with short-lasting (3-7 days) flowing drain of the inflammatory focus. Implantation of gentamicin balls was renewed after 14-18 days achieving in all cases sterilization of the inflammatory focus within the bone. The applied treatment allowed to reject quickly the general antibiotic therapy. After operational course for all children was normal.
Assuntos
Gentamicinas/uso terapêutico , Metilmetacrilatos/uso terapêutico , Osteíte/tratamento farmacológico , Doença Aguda , Criança , Pré-Escolar , Implantes de Medicamento , Doenças Hematológicas/complicações , Humanos , Lactente , Recém-Nascido , Osteíte/etiologiaRESUMO
During the years 1984-1987 obliteration of the oesophageal varices was done in 13 children with the portal hypertension. The method of treatment was based on injections of varicocid causing the thrombo-obliterative changes in the blood-vessels. Each of performed interventions (about 70) was successful and complications were never observed. Because of its high effectiveness and absence of harmful effects sclerotherapy is a valuable therapeutic method.
Assuntos
Varizes Esofágicas e Gástricas/terapia , Ácidos Graxos/uso terapêutico , Hemorragia Gastrointestinal/prevenção & controle , Soluções Esclerosantes/uso terapêutico , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , MasculinoRESUMO
The concentration of acute phase proteins following burn is known to increase in serum rapidly, while that of fibronectin often decreases. Fibronectin (Fn) has been demonstrated to serve as an opsonin involved in the ingestion phase in phagocytic process. On the other hand, some acute phase proteins such as alpha-1 acid glycoprotein (AG) may inhibit phagocytic activity. In our study, the phagocytic activity of normal granulocytes was decreased by those sera in which a high level of AG was accompanied by a fall in the Fn Level. Attempts to detect a possible link between the acute phase response and fibronectin led as to study whether fibronectin and AG may interact antagonistically on the phagocytic activity of neutrophils. For this reason we calculated the Fn/Ag coefficient. We showed that an Fn/Ag coefficient in normal sera equals more than 0.20. The higher the coefficient, the better the opsonic activity of sera. We propose here that an Fn/AG coefficient may be a useful risk factor for infections in burned patients.