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1.
J Pediatr Surg ; 36(11): 1662-5, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11685697

RESUMO

PURPOSE: This study was aimed at determining whether fetal tissue constructs can be engineered from cells normally found in the amniotic fluid. METHODS: A subpopulation of morphologically distinct cells was isolated mechanically from the amniotic fluid of pregnant ewes (n = 5) and expanded selectively. Its lineage was determined by immunofluorescent staining against multiple intermediate filaments and surface antigens. Proliferation rates were determined by both oxidation and total DNA assays and compared with immunocytochemically identical adult and fetal sheep cells. Statistical analysis was by analysis of variance for repeated measures (ANOVA). After expansion, the amniocytes were seeded onto a polyglycolic acid polymer/poly-4-hydroxybutyrate scaffold. The resulting construct was analyzed by both optical and scanning electron microscopy. RESULTS: The immunocytochemical profile of expanded amniocytes was consistent with a mesenchymal, fibroblast/myofibroblast cell lineage. These cells proliferated significantly faster than comparable fetal and adult cells in culture. Amniocyte construct analysis showed dense, confluent layers of cells firmly attached to the scaffold, with no evidence of cell death. CONCLUSIONS: (1) Subpopulations of fetal mesenchymal cells can be isolated consistently from the amniotic fluid. (2) Mesenchymal amniocytes proliferate more rapidly in vitro than comparable fetal and adult cells. (3) Mesenchymal amniocytes attach firmly to polyglycolic acid polymer. The amniotic fluid can be a reliable and practical source of cells for the engineering of select fetal tissue constructs.


Assuntos
Líquido Amniótico/citologia , Feto , Mesoderma/citologia , Engenharia Tecidual , Análise de Variância , Animais , Divisão Celular , Linhagem Celular/citologia , Separação Celular/métodos , Feminino , Ovinos
2.
J Pediatr Surg ; 35(6): 906-12; discussion 912-3, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10873034

RESUMO

BACKGROUND/PURPOSE: The authors' have shown pulmonary alveolarization (capillary and alveolar growth) both after fetal tracheal occlusion and postnatal pulmonary distension. The trophic and developmental mechanisms responsible for this growth remain largely unknown; however, experimental systems have defined an enhanced expression of angiogenic proteins in response to tissue stretch. The authors hypothesize that the stimulation of pulmonary alveolarization after stretch is secondary to upregulation of the potent endothelial cell mitogen vascular endothelial growth factor (VEGF) and that the endothelial cell represents the central stimulus of parenchymal growth. METHODS: A mixed primary pulmonary cell culture obtained by enzymatic digestion of fetal, neonatal, and adult mouse lung was plated on Bioflex elastomer bottom plates, grown to confluence, rendered quiescent, and subjected to continuous cycles of stretch-relaxation with nonstretched cells as controls. Cells were harvested at time-points 0, 30 minutes, 2 hours, 4 hours, 8 hours, and 24 hours. RNA was extracted and VEGF gene expression analyzed by semiquantitative reverse transcription polymerase chain reaction (RT-PCR). Similar cell groups were harvested, processed, and analyzed utilizing Western Blot techniques. VEGF PCR of mRNA isolated from fetal sheep subjected to surgical creation of diaphragmatic hernia both with (DH-TL) and without (DH) tracheal ligation also was analyzed. RESULTS: VEGF mRNA isoforms 120, 164, and 188 showed increased expression in all stretched groups, which was noted by 30 minutes with maximal expression seen at 2 to 4 hours and a return to baseline expression by 24 hours. VEGF protein was similarly elevated in all stretched cell groups. In preliminary studies, DH/TL sheep showed upregulation of VEGF compared with DH sheep alone. CONCLUSIONS: These data show in an in vitro system that "pulmonary stretch" upregulates VEGF mRNA and protein expression supporting the role of angiogenesis in the stretch-induced pulmonary alveolarization. The authors speculate that such angiogenic activity is a rate-limiting factor in stimulating alveolar epithelial development, and as a treatment modality, therapeutic angiogenesis may provide a noninvasive method with which to treat pulmonary hypoplasia.


Assuntos
Fatores de Crescimento Endotelial/genética , Expressão Gênica , Pulmão/crescimento & desenvolvimento , Linfocinas/genética , Neovascularização Fisiológica , Regulação para Cima , Envelhecimento , Animais , Animais Recém-Nascidos , Western Blotting , Células Cultivadas , Fatores de Crescimento Endotelial/metabolismo , Feto , Hérnia Diafragmática/genética , Hérnia Diafragmática/fisiopatologia , Hérnias Diafragmáticas Congênitas , Ligadura , Pulmão/irrigação sanguínea , Pulmão/metabolismo , Linfocinas/metabolismo , Camundongos , Camundongos Endogâmicos , Estimulação Física , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Ovinos , Traqueia/fisiologia , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
4.
Pediatr Surg Int ; 13(2-3): 149-53, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9563030

RESUMO

Minimally invasive surgery (MIS) for cancer patients has become widely accepted in general surgery, however, it has not completely replaced the standard open operative procedures in pediatric oncology. The aim of this study was to evaluate the host relationship following MIS in a murine model of retroperitoneal neuroblastoma (NB) Immature, 5- to 7-week-old male A/J mice weighing 18-23 g were inoculated with either C1300 or TBJ NB in the left retroperitoneal space. At 4 days (early stage) or 11 days (late stage) following tumor inoculation, the animals underwent a laparotomy or pneumoperitoneum with carbon dioxide under general inhalational anesthesia. Animal survival, tumor growth, and postoperative changes in body weight were observed. In the model of subcutaneous TBJ NB, distant metastases following the laparotomy or MIS technique were also evaluated. Each surgical group had a sample size > or = 12, and data were statistically analyzed by ANOVA and the chi-square test where appropriate. P < 0.05 was considered to be significant. There were no significant differences in animal survival, tumor growth, or distant metastases among surgical groups in any combination of type and stage of tumor. The only salutary influence of MIS was seen in a model of early-stage NB, where the decrease in body weight on postoperative day 7 was preserved when compared to post-laparotomy weight loss. We conclude that when compared to conventional laparotomy, the MIS access technique does not influence the outcome in a model of retroperitoneal murine NB.


Assuntos
Neuroblastoma/cirurgia , Neoplasias Retroperitoneais/cirurgia , Animais , Modelos Animais de Doenças , Laparotomia , Masculino , Camundongos , Camundongos Endogâmicos A , Procedimentos Cirúrgicos Minimamente Invasivos , Neuroblastoma/secundário , Neoplasias Retroperitoneais/patologia , Resultado do Tratamento , Células Tumorais Cultivadas
5.
J Pediatr Surg ; 33(3): 457-61, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9537557

RESUMO

BACKGROUND/PURPOSE: Although minimally invasive surgery (MIS) has been broadly applied in patients with cancer of the gastrointestinal tract, the etiology of port-site tumor recurrence (PSR) after laparoscopic cancer surgery remains unclear. The authors report here an analysis of PSR in a model of murine neuroblastoma after laparoscopic tumor biopsy and propose a mechanism for this complication as well as a potential treatment. METHODS: Immature 5- to 7-week old male A/J mice (18-23 g) were subcutaneously inoculated with the minimally immunogenic TBJ-neuroblastoma (TBJ-NB) in the left flank and divided into three treatment groups. The following operations were performed 14 days after tumor inoculation: group 1, additional intraperitoneal or intravenous injection of TBJ-NB during CO2 pneumoperitoneum; group 2, simulated transperitoneal tumor biopsy using MIS techniques during either CO2 pneumoperitoneum or gasless suspension; Group 3, intraperitoneal (IP) or intravenous (IV) administration of cyclophosphamide on postoperative days 0 and 3 to prevent PSR after simulated tumor biopsy during CO2 pneumoperitoneum. RESULTS: In group 1, the incidence of PSR was 0% in the intravenously injected mice versus 63% in mice injected intraperitoneally with TBJ-NB. In group 2, no significant difference in the incidence of PSR was seen between simulated tumor biopsy (89%) animals with CO2 pneumoperitoneum versus animals with gasless suspension (81%). In group 3, mice that did not receive any chemotherapy had an 89% incidence of PSR. Administration of cyclophosphamide via either the IP or IV route effectively prevented PSR, although there was no difference in the incidence of PSR between the two routes (IP 12% versus IV 13%). CONCLUSIONS: The data suggest that PSR in tumor-bearing hosts may be caused by direct seeding of exfoliated tumor cell, and not by hematogenous metastases. Contrary to the other reports, CO2 pneumoperitoneum was not found to be essential for the development of PSR. Furthermore, the authors conclude that postoperative chemotherapy may be useful in preventing PSR after MIS in patients bearing chemotherapy-sensitive tumors such as neuroblastoma.


Assuntos
Laparoscopia/efeitos adversos , Recidiva Local de Neoplasia , Inoculação de Neoplasia , Neuroblastoma/patologia , Animais , Antineoplásicos/administração & dosagem , Biópsia por Agulha/efeitos adversos , Masculino , Camundongos , Recidiva Local de Neoplasia/etiologia , Recidiva Local de Neoplasia/prevenção & controle , Transplante de Neoplasias , Neuroblastoma/secundário , Neoplasias Peritoneais/patologia , Pneumoperitônio Artificial/efeitos adversos
6.
Nutrition ; 14(1): 119-23, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9437697

RESUMO

Central venous access for the purpose of supplying parenteral nutrition to the pediatric age group requires a careful definition of the patient's caloric need, estimated duration of therapy, and an assessment of available sites. Peripheral vein parenteral nutrition is limited by caloric density of the nutrient fluids, while peripherally inserted central catheters (PICC) offers a new technology for accessing central veins while obviating the risk of central vein access. Routes of central vein access are several and there are also a variety of catheters available for placement. Tunneled percutaneous placement of silicone rubber cuffed catheters via the subclavian vein approach is that technique we use most commonly. The risks of such access catheters include mechanical risks of placement, venous thrombosis of the access sites, and most importantly catheter related infections, either at the exit site, the subcutaneous tunnel or pouch, or even generalized sepsis. With a full knowledge of the spectrum of access techniques, access materials, and risks, safe total parenteral nutrition can be safely delivered to the children in need.


Assuntos
Cateterismo Venoso Central , Nutrição Parenteral , Pediatria , Cateterismo Venoso Central/efeitos adversos , Cateterismo Venoso Central/instrumentação , Cateterismo Venoso Central/métodos , Criança , Pré-Escolar , Ingestão de Energia , Humanos , Lactente , Recém-Nascido , Infecções/etiologia , Trombose/etiologia
8.
Pediatr Surg Int ; 12(7): 505-8, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9238117

RESUMO

Precise staging of malignant disease is required to define the optimum therapeutic strategy. In spite of technical advances, the sensitivity of conventional imaging techniques is usually limited to defining lesions of at least 1 cm in size. Laparoscopy is a sensitive technique that is very valuable for visual inspection of the abdominal cavity and the identification of small surface lesions. However, non-superficial lesions may escape detection due to the lack of tactile sensitivity. As an adjunct to laparoscopy, this study, utilizing a young swine model, has analyzed the detectability of intra-abdominal lymph nodes by laparoscopic ultrasound (LU). Lymph nodes in and around the hepatoduodenal ligament, examined and measured by LU, were resected by subsequent open laparotomy in eight young, mixed-breed swine. The numbers and sizes of lymph nodes detected by LU and resected at laparotomy were compared and analyzed statistically. Forty-six lymph nodes were resected by laparotomy, while LU failed to detect 3 small nodes (sensitivity, 43/46 = 93.5%). The sizes of lymph nodes in the LU group correlated strongly with the sizes actually measured in the laparotomy group (r = 0.936, P < 0.001). Twenty-six small lymph nodes, which conventional extracorporeal imaging might have failed to diagnose, were detected accurately by LU (r = 0.877, P < 0.001). This new technology may not only be effective for staging intra-abdominal malignant disease, but adds the benefit of obtaining tissue samples under direct vision using minimally invasive techniques.


Assuntos
Linfonodos/diagnóstico por imagem , Metástase Linfática/diagnóstico por imagem , Estadiamento de Neoplasias/métodos , Abdome , Animais , Estudos de Viabilidade , Laparoscopia , Sensibilidade e Especificidade , Suínos , Ultrassonografia de Intervenção
9.
Cancer ; 79(9): 1757-66, 1997 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-9128993

RESUMO

BACKGROUND: The prognosis for children with neuroblastoma (NB) remains dismal, in part because of extent of disease at diagnosis as well as resistance of tumors to conventional therapies. However, human NB exhibits many favorable traits, including the capability to mature into a more benign form or to regress spontaneously. A murine model of disease that could permit eventual genetic manipulation, so that such beneficial traits could be identified or even augmented, would be most useful. METHODS: This report details an analysis of the contemporary study of the tumor growth, metastases, immunogenicity, and immunotherapy of murine NB and compares it with known patterns of clinical NB. RESULTS: Striking similarities exist in the local tumor growth and metastatic behaviors of murine and human NB, behaviors that in part may be related to a host-tumor immunologic response. The naturally low expression of class I antigen in NB, the ability to augment that expression with cytokines, and the phenotype of the cellular and humoral immune response to NB are strikingly similar in human and murine hosts. Comparable immunotherapeutic potential exists. There have been rare and sporadic observations of spontaneous regression of an existing murine NB, unlike the more predictable regression of Evans Stage IV-S clinical NB. CONCLUSIONS: The many similar biologic, physiologic, and immunologic characteristics of human and murine NB make the murine model a valuable adjunctive aid in furthering our understanding of human disease.


Assuntos
Modelos Animais de Doenças , Neuroblastoma/imunologia , Animais , Humanos , Camundongos
10.
J Am Coll Surg ; 184(4): 357-63, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9100680

RESUMO

BACKGROUND: Laparoscopic operative procedures have decreased postoperative pain and the length of hospitalization. In addition, evidence supports a physiologic benefit from laparoscopic surgery. By analyzing several parameters of peritoneal macrophage function, we report a comparison of the magnitude of postoperative stress between two types of minimally invasive access techniques contrasted with an open laparotomy, in a murine model. STUDY DESIGN: Immature male A/J mice were exposed to pneumoperitoneum using carbon dioxide, gasless suspension, or laparotomy. Peritoneal macrophages were then harvested, and the number and viability of the macrophages from each group of mice were compared. Last, as a marker of postoperative stress, the in vitro production of nitric oxide and tumor necrosis factor alpha by these macrophages was determined. RESULTS: The number of peritoneal macrophages and the viability of the macrophages in the laparotomy group were significantly decreased 4 hours after operation compared with the minimally invasive and control groups. In addition, macrophage production of tumor necrosis factor alpha and nitric oxide, two markers of macrophage stress, 24 hours after operation was significantly increased in the laparotomy group compared with animals serving as controls. Gasless suspension and pneumoperitoneum decreased the number of macrophages to a lesser degree than did open laparotomy and did not affect macrophage viability. Moreover, gasless suspension and pneumoperitoneum did not lead to an increase in tumor necrosis factor alpha or nitric oxide production by peritoneal macrophages. CONCLUSIONS: Postoperative stress, assessed by a decrease in macrophage viability and an increase in cytotoxic cytokine production, is maximized after laparotomy compared with stress in murine hosts that underwent minimally invasive treatment. These data provide basic scientific evidence for the possible physiologic benefit of minimally invasive techniques.


Assuntos
Laparoscopia , Macrófagos Peritoneais/fisiologia , Procedimentos Cirúrgicos Minimamente Invasivos , Estresse Fisiológico/fisiopatologia , Animais , Sobrevivência Celular , Masculino , Camundongos , Camundongos Endogâmicos , Óxido Nítrico/biossíntese , Pneumoperitônio Artificial , Fator de Necrose Tumoral alfa/biossíntese
11.
J Pediatr Surg ; 32(2): 287-93, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9044139

RESUMO

The finding that angiogenesis plays an important role in the progression and metastasis of malignant tumors has led to the development of several antiangiogenic drugs. The authors report here an examination of the effect of the antiangiogenic agent TNP-470 on the growth, metastases, and survival of two differing murine neuroblastoma cell lines, TBJ and C1300. We found that TNP-470 significantly reduced primary tumor volumes in mice injected with either cell line. In addition, antiangiogenic therapy significantly reduced the size of axillary lymph node metastases in both groups as well as decreased the size of liver metastases in mice receiving TBJ neuroblastoma. TNP-470 treatment also improved animal survival. These data suggest that antiangiogenic therapy retards the growth of primary and metastatic murine neuroblastoma. We speculate that antiangiogenic therapy may be a useful therapeutic modality in the treatment of advanced neuroblastoma once side effects and appropriate dosage requirements are determined.


Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Neovascularização Patológica/tratamento farmacológico , Neuroblastoma/tratamento farmacológico , Sesquiterpenos/uso terapêutico , Animais , Cicloexanos , Masculino , Camundongos , Camundongos Endogâmicos , Neuroblastoma/patologia , Neuroblastoma/secundário , O-(Cloroacetilcarbamoil)fumagilol , Células Tumorais Cultivadas
12.
Biochemistry ; 36(7): 1891-9, 1997 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-9048575

RESUMO

The kinetic mechanism in vitro of the folding and assembly of the heterodimeric flavin monooxygenase bacterial luciferase has been defined by a unique set of rate constants which describe both the productive refolding pathway and competing off-pathway reactions in 50 mM phosphate, pH 7.0 at 18 degrees C. The individual alpha and beta subunits fold independently to form heterodimerization-competent species, alpha i and beta i. The alpha i beta i species can interact to form an inactive heterodimeric intermediate, [alpha beta ]i, which isomerizes to form the active alpha beta structure; the structure of the enzyme has been determined to 1.5 A resolution [Fisher, A. J., Thompson, T. B., Thoden, J. B., Baldwin, T. O., & Rayment, I. (1996) J. Biol. Chem. 271, 21956-21968]. In the absence of alpha i, beta i can form a kinetically trapped homodimer, beta 2, with a second-order rate constant of about 180 M-1 s-1 [Sinclair, J. F., Ziegler, M. M., & Baldwin, T. O. (1994) Nat. Struct. Biol. 1, 320-326]; the structure of beta 2 has recently been reported [Thoden. J. B., Holden, H. M., Fisher, A. J., Sinclair. J. F., Wesenberg, G., Baldwin, T.O., & Rayment, I. (1997) Protein Sci. 6, 13-23]. The beta i species, or some other form that precedes beta i on the refolding pathway, can also undergo a first-order conversion into a form (designated beta x) that cannot associate with alpha i to form the native enzyme. The rate constant for this process, assigned here, accounts well for the previously observed dependence of final yield on concentration of refolding species [Ziegler, M.M., Goldberg, M.E., Chaffotte, A. F., & Baldwin, T. O. (1993) J. Biol. Chem. 268, 10760-10765]. In simulations of the refolding reaction, all processes associated with the refolding of the individual subunits were combined into single first-order rate constants for each subunit which were consistent with the rate constants determined from stopped-flow circular dichroism studies. The first-order rate constant for the folding of the alpha subunit, estimated from the concentration-independent lag preceding the appearance of active enzyme, and the second-order rate constant for assembly of alpha i and beta i into the heterodimer, estimated from the concentration-dependent rate of appearance of active enzyme, were consistent with the rates of first- and second-order processes monitored by changes in fluorescence of an extrinsic probe [the product of modification with N-(4-anilino-1-naphthyl)maleimide] on the alpha subunit during refolding. The rate constant for the isomerization of [alpha beta]i to form the active heterodimer was estimated from the kinetic data of a secondary dilution experiment and from fluorescence measurements of protein diluted 20-fold from 2.1 M urea-containing buffer. The rate constants reported here for the kinetic mechanism of refolding permitted simulation of the time courses and yields for activity recovery during the refolding of luciferase from about 1 to 25 micrograms/mL which are in excellent agreement with our previously reported data.


Assuntos
Luciferases/química , Luciferases/metabolismo , Dobramento de Proteína , Dicroísmo Circular , Ativação Enzimática , Corantes Fluorescentes , Cinética , Maleimidas , Estrutura Secundária de Proteína , Vibrio/enzimologia
13.
J Pediatr Surg ; 31(8): 1166-9, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8863257

RESUMO

The members of the Section on Surgery of the American Academy of Pediatrics were surveyed to determine the practice of North American pediatric surgeons in infants with inguinal hernia (IH). Case-scenario multiple-choice-design questionnaires regarding hernias and hydroceles were sent to all members of the Surgical Section, and responses were received from 292 (50%). In healthy full-term infant boys with asymptomatic reducible IH, 82% of responders perform repair electively, no matter what the age or weight. In full-term girls with a reducible ovary, 59% perform surgery at the next available time; if the ovary is nonreducible but asymptomatic, 44% operate emergently or urgently and 42% at the next elective slot. In former preemies, the pattern of repair is as follows. (1) For those recently discharged after 2 months in the neonatal intensive care unit (NICU) with reducible IH, 65% perform the repair when convenient. (2) A general anesthetic is used in 70%; 15% use spinal anesthesia, and 11% use caudal block with sedation. (3) If the repair is done in the hospital outpatient (same-day) unit, 36% wait until 50 weeks postconception (PC) and 33% wait until 60 weeks PC. (4) if the baby's weight is at least 1,000 g. 71% perform the repair before discharge. The pain control choice after childhood IH repair is Tylenol for 30%, local infiltration biquivacaine for 30%, caudal block for 22%, regional block for 11%, and Tylenol/codeine combined for 7%. In 6-week-old full-term infants with communicating hydroceles without definite "hernia," two thirds treat as an IH with elective repair as soon as possible. With respect to contralateral exploration in infants with unilateral IH, 65% perform it in males if they are < or = 2 years of age and 84% use it in females of up to 4 years of age. This approach is not influenced by presenting side, presence of hydrocele, or history of prematurity. Laparoscopic evaluation of the contralateral IH is performed by only 6% of responders, 40% of whom use the open ipsilateral sac for laparoscope introduction.


Assuntos
Hérnia Inguinal/cirurgia , Padrões de Prática Médica , Hidrocele Testicular/cirurgia , Fatores Etários , Peso Corporal , Pré-Escolar , Feminino , Cirurgia Geral , Humanos , Lactente , Recém-Nascido , Laparoscopia , Masculino , Dor Pós-Operatória/tratamento farmacológico , Pediatria , Sociedades Médicas , Inquéritos e Questionários , Estados Unidos
14.
J Am Coll Surg ; 182(3): 233-40, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8603243

RESUMO

BACKGROUND: In the era of managed care, the operative procedure applied to solve a given problem should vary with the status of the patient, the training and experience of the specialist, an analysis of morbidity and mortality rates, and a cost analysis of therapeutic alternatives. The purpose of this study was to critically analyze three different techniques for gastric feeding access in children. STUDY DESIGN: A retrospective analysis of patients who underwent primary feeding gastrostomy was performed at our institution. Patients who underwent gastrostomy placement concurrently with another major procedure were excluded. RESULTS: Over a 36-month period, 98 children underwent placement of a feeding gastrostomy by one of three alternative techniques: an open Stamm gastrostomy (Stamm, n=47), a pull-out percutaneous endoscopic gastrostomy (PEG, n=32), or an antegrade percutaneous fluoroscopically guided gastrostomy (PFGG, n=19). An open gastrostomy was performed more frequently in younger patients (average age, 49.7+/-11.9 months for PFGG). The sex distribution and indication for tube placement were similar in all groups (altered mental status: Stamm 43 percent, PEG 19 percent, and PFGG 38 percent; mechanical feeding difficulty: Stamm 66 percent, PEG 13 percent, and PFGG 21 percent; or failure to thrive Stamm 58 percent, PEG 17 percent, and PFGG 25 percent). Complications were most common in this high-risk patient population with PEG (19 percent), when compared with PFGG (16 percent) and Stamm (11 percent), although these were not statistically significant. Whereas reflux was frequent (Stamm 6 percent, PEG 9 percent, and PFGG 21 percent), only three patients in the entire series required a subsequent antireflux operation during the observation period. The three procedures were similar on hospital charge analysis (Stamm $1,316,29+/-63.33. PEG $1,130.04+/-94.88, and PFGG $1,079.83+/-109.12). When professional fees were included, the PFGG may be more economical than both the PEG and Stamm gastrostomy (Stamm $3,101.29+/-73/33. PEG $3,314.04+/-94.88, and PFGG $1,485.77+/-74.41, p<0.05). However, this may be misleading because the radiologist's fee was absorbed into the hospital charge is some cases, and therefore could not be fully accounted for in the total professional fee. CONCLUSIONS: The data from our institution demonstrate that there is no significant difference in these three feeding-access techniques when comparing procedural cost-effectiveness, indications for tube placement, or morbidity rates. The choice of procedure should be individualized giving consideration to the overall health of the child, the comfort of the specialist peforming the given procedure, and the institutional experience.


Assuntos
Nutrição Enteral/métodos , Gastroscopia/métodos , Gastrostomia/métodos , Anestesia Geral , Antibioticoprofilaxia , Cefalosporinas/uso terapêutico , Criança , Pré-Escolar , Nutrição Enteral/efeitos adversos , Nutrição Enteral/estatística & dados numéricos , Feminino , Fluoroscopia/métodos , Fluoroscopia/estatística & dados numéricos , Gastroscopia/estatística & dados numéricos , Gastrostomia/efeitos adversos , Gastrostomia/estatística & dados numéricos , Hospitais Pediátricos , Humanos , Lactente , Masculino , Ohio/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos , Técnicas de Sutura
15.
Curr Opin Struct Biol ; 5(6): 798-809, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8749369

RESUMO

The generation of light by living organisms such as fireflies, glow-worms, mushrooms, fish, or bacteria growing on decaying materials has been a subject of fascination throughout the ages, partly because it occurs without the need for high temperatures. The chemistry behind the numerous bioluminescent systems is quite varied, and the enzymes that catalyze the reactions, the luciferases, are a large and evolutionarily diverse group. The structure of the best understood of these intriguing enzymes, bacterial luciferase, has recently been determined, allowing discussion of features of the protein in structural terms for the first time.


Assuntos
Bactérias/enzimologia , Luciferases/química , Luciferases/metabolismo , Sítios de Ligação , Mononucleotídeo de Flavina/metabolismo , Ligação de Hidrogênio , Cinética , Luciferases/genética , Medições Luminescentes , Modelos Moleculares , Oxigênio/metabolismo , Conformação Proteica , Dobramento de Proteína , Estrutura Secundária de Proteína
16.
Curr Opin Pediatr ; 7(5): 547-52, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8541955

RESUMO

Inflammatory bowel disease remains a serious chronic illness in children. Recent developments in the care of these patients involves both basic science research into the pathophysiology of ulcerative colitis and Crohn's disease and the development of refinements in the surgical techniques and medical therapies available as treatment options. In Crohn's disease, a new steroid analogue (budesonide) shows some promise as a possible medical treatment that would limit the devastating side effects of steroids in children. In addition, the bowel-sparing technique of strictureplasty has now been reported in children with good results. In ulcerative colitis, the surgical technique of endorectal pull-through continues to evolve with reports of the efficacy of specific pouch designs and surgical techniques. An understanding of pouchitis, the most common complication of endorectal pull-through, has focused on documenting specific alterations in the microbiology and physiology of the pouch, as well as investigating a possible link between autoantibodies and susceptibility to this complication.


Assuntos
Doenças Inflamatórias Intestinais/terapia , Administração Tópica , Anti-Inflamatórios/uso terapêutico , Budesonida , Criança , Colite Ulcerativa/cirurgia , Doença de Crohn/tratamento farmacológico , Doença de Crohn/cirurgia , Glucocorticoides , Humanos , Doenças Inflamatórias Intestinais/cirurgia , Complicações Pós-Operatórias , Pregnenodionas/uso terapêutico , Proctocolectomia Restauradora
17.
J Pediatr Surg ; 30(10): 1430-2, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8786480

RESUMO

Mucosal perforation during Fredet-Ramstedt pyloromyotomy traditionally has been repaired with muscular and mucosal reapproximation, pyloric rotation, and repeat myotomy. The purpose of this study was to determine whether simple mucosal closure is a safe alternative repair technique for such a perforation. The authors reviewed their experience of pyloromyotomies over a 21-year period and found a 1.67% incidence (15 of 896) of mucosal perforation. Four of these patients had repair with rotation and repeat myotomy, and 11 had repair with primary mucosal approximation. The patients were compared with respect to demographics, duration of operation, postoperative feeding intolerance, time from operation until discharge, and postoperative complications. No differences were noted between the two groups. Interestingly, when the perforation group (n = 15) was compared with the nonperforation group (n = 881), the mean age at time of pyloromyotomy was significantly higher for the group with perforation 48 days v 34 days; P = .0021, Student's t test). The authors conclude that those most likely to suffer mucosal perforation during pyloromyotomy are older patients with pyloric stenosis. Such mucosal perforation can be repaired with equal efficacy and safety using the traditional pyloric rotation approach or primary mucosal closure.


Assuntos
Mucosa Gástrica/cirurgia , Estenose Pilórica/cirurgia , Piloro/cirurgia , Feminino , Mucosa Gástrica/lesões , Humanos , Lactente , Recém-Nascido , Complicações Intraoperatórias/cirurgia , Masculino , Métodos , Músculos/cirurgia , Ruptura
18.
J Pediatr Surg ; 30(7): 959-65; discussion 966, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7472953

RESUMO

Increased oxidation of fat is an important host response to sepsis, and carnitine is essential for long-chain fatty acid oxidation. Because neonates have low levels of carnitine, their ability to respond to a septic insult may be impaired. The purpose of this study was to compare fatty acid and carnitine metabolism in septic weanling (60 to 85 g) and septic adult (285 to 310 g) rats. Sepsis was induced in weanling and adult male Sprague-Dawley rats by cecal ligation and puncture (CLP). The rats were killed 16 hours after CLP or sham operation, and serum glucose, lactate, beta-hydroxybutyrate, fatty acid, carnitine, liver fatty acid, and tissue carnitine levels were measured. The data suggest that during sepsis weanling rats may be more dependent on fatty acid oxidation than adult rats are, as evidenced by their elevated serum fatty acid and acylcarnitine levels, and relative hypoglycemia and hyperketonemia. In addition, although total serum carnitine levels were increased in both adult and weanling septic rats, tissue carnitine levels of weanling rats became significantly depleted during sepsis, unlike in adult rats. This study supports further investigation regarding the role of exogenous carnitine in newborn sepsis.


Assuntos
Envelhecimento/metabolismo , Infecções Bacterianas/metabolismo , Carnitina/metabolismo , Ácidos Graxos/metabolismo , Ácido 3-Hidroxibutírico , Animais , Glicemia/análise , Carnitina/sangue , Ácidos Graxos/sangue , Ácidos Graxos não Esterificados/sangue , Ácidos Graxos não Esterificados/metabolismo , Hidroxibutiratos/sangue , Hipoglicemia/sangue , Cetonas/sangue , Rim/metabolismo , Lactatos/sangue , Fígado/metabolismo , Masculino , Músculo Esquelético/metabolismo , Miocárdio/metabolismo , Oxirredução , Ratos , Ratos Sprague-Dawley , Distribuição Tecidual , Desmame
19.
J Pediatr Surg ; 30(7): 994-8; discussion 998-9, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7472960

RESUMO

Necrotizing enterocolitis (NEC) is a serious condition affecting predominantly the premature infant. The purpose of this study is to report a multicenter experience of complications in 252 infants requiring surgical therapy for NEC. Data from eight institutions for the years 1980 through 1990 were collected and analyzed for infants undergoing surgical therapy for NEC. Records were reviewed for gestational age, birth weight, age at operation, indications for operation, degree of intestinal involvement, operation(s) performed, complications, and 30-day mortality rates. A total of 264 infants underwent surgical intervention for NEC during the study period. Complete information was available for 252 patients. The mean gestational age was 31 +/- 5 weeks and the mean birth weight was 1,552 +/- 823 g. The mean age at operation was 18 +/- 35 days. Pneumoperitoneum was the most common indication for operation (42%). The 30-day survival rate was 72%. Eighty-one percent of patients underwent primary laparotomy, whereas peritoneal drainage was performed in 48 (19%) patients. Postoperative complications were identified in 119 (47%) patients. The most common postoperative complications were sepsis (9%), intestinal strictures (9%), and short gut (9%). Wound infections occurred in 6%, and the incidence of intraabdominal abscess formation was only 2.3%. Gestational age < 27 weeks (P < .005) and birth weight < 1,000 g (P < .005) were associated with significantly increased mortality but no increase in postoperative morbidity. The incidence of complications was similar in the very low birth weight (< 1,000 g) infants (51%) compared with infants > or = 1,000 g (46%).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Enterocolite Pseudomembranosa/cirurgia , Doenças do Prematuro/cirurgia , Recém-Nascido Prematuro , Complicações Pós-Operatórias , Fatores Etários , Infecções Bacterianas , Peso ao Nascer , Constrição Patológica/etiologia , Drenagem/efeitos adversos , Enterocolite Pseudomembranosa/patologia , Idade Gestacional , Humanos , Recém-Nascido , Doenças do Prematuro/patologia , Recém-Nascido de muito Baixo Peso , Enteropatias/etiologia , Intestinos/patologia , Laparotomia/efeitos adversos , Peritônio , Pneumoperitônio/cirurgia , Estudos Retrospectivos , Síndrome do Intestino Curto/etiologia , Infecção da Ferida Cirúrgica/etiologia , Taxa de Sobrevida , Resultado do Tratamento
20.
J Pediatr Gastroenterol Nutr ; 19(3): 295-8, 1994 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7815260

RESUMO

Management of extreme short bowel syndrome (SBS) has changed dramatically over the last 20 years with notable improvements in survival and quality of life in patients with this syndrome. A review of our institution's medical records over a 12-year period (1980-1992) revealed 32 patients with < 100 cm (range, 14-94; median, 40) of functional small bowel after intestinal resection. The causes of intestinal loss included necrotizing enterocolitis (11 cases), atresias (8 cases), long-segment Hirschsprung's disease (5 cases), midgut volvulus (5 cases) and gastroschisis (3 cases). The mean follow-up period was 4.2 years, and four deaths were recorded (12.5%). Survival of eight of nine (88.9%) patients without an ileocecal valve (ICV) and with < 40 cm of small bowel was noted. The absence of an ICV, however, was associated with significantly prolonged total parenteral nutrition. Follow-up surgical procedures, including intestinal lengthening, tapering enteroplasty. Martin's procedure, longitudinal myectomy-myotomy, and ostomy take-down, were performed in 20 of the patients (64%). Prolonged survival and normal development can be expected for the patient with severe SBS who is given meticulous nutritional support and treated with carefully planned secondary surgical intervention. These results are also seen in patients with extreme SBS (< 40 cm residual small bowel length) and no ICV.


Assuntos
Nutrição Parenteral Total , Síndrome do Intestino Curto/terapia , Seguimentos , Hospitalização , Humanos , Valva Ileocecal , Tempo de Internação , Síndrome do Intestino Curto/cirurgia , Resultado do Tratamento
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