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1.
Proc Natl Acad Sci U S A ; 105(2): 464-9, 2008 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-18180449

RESUMO

Perennial herbaceous plants such as switchgrass (Panicum virgatum L.) are being evaluated as cellulosic bioenergy crops. Two major concerns have been the net energy efficiency and economic feasibility of switchgrass and similar crops. All previous energy analyses have been based on data from research plots (<5 m2) and estimated inputs. We managed switchgrass as a biomass energy crop in field trials of 3-9 ha (1 ha = 10,000 m2) on marginal cropland on 10 farms across a wide precipitation and temperature gradient in the midcontinental U.S. to determine net energy and economic costs based on known farm inputs and harvested yields. In this report, we summarize the agricultural energy input costs, biomass yield, estimated ethanol output, greenhouse gas emissions, and net energy results. Annual biomass yields of established fields averaged 5.2-11.1 Mg x ha(-1) with a resulting average estimated net energy yield (NEY) of 60 GJ x ha(-1) x y(-1). Switchgrass produced 540% more renewable than nonrenewable energy consumed. Switchgrass monocultures managed for high yield produced 93% more biomass yield and an equivalent estimated NEY than previous estimates from human-made prairies that received low agricultural inputs. Estimated average greenhouse gas (GHG) emissions from cellulosic ethanol derived from switchgrass were 94% lower than estimated GHG from gasoline. This is a baseline study that represents the genetic material and agronomic technology available for switchgrass production in 2000 and 2001, when the fields were planted. Improved genetics and agronomics may further enhance energy sustainability and biofuel yield of switchgrass.


Assuntos
Etanol/química , Panicum/química , Agricultura/métodos , Poluentes Atmosféricos , Biomassa , Celulose/química , Conservação de Recursos Energéticos , Conservação dos Recursos Naturais , Produtos Agrícolas , Fontes Geradoras de Energia , Meio Ambiente , Gasolina , Geografia , Efeito Estufa , Meio-Oeste dos Estados Unidos
2.
Cancer Res ; 52(5): 1171-5, 1992 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-1737376

RESUMO

We have previously shown that O6-benzylguanine can be used to deplete cells of the DNA repair protein O6-alkylguanine-DNA alkyltransferase and to enhance the sensitivity of human glioma (SF767) and colon tumor (HT29) cells to the cytotoxic effects of alkylnitrosoureas. In the present study, the combination of O6-benzylguanine and 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) was evaluated in vitro to determine the number of DNA interstrand cross-links formed and in vivo to compare the therapeutic index with that of BCNU alone. The number of DNA interstrand cross-links, as measured by alkaline elution, was increased in HT29 cells treated with 10 microM O6-benzylguanine for 2 h prior to BCNU exposure compared to cells treated with BCNU only. The number of single strand breaks was not increased by prior exposure to O6-benzylguanine. To evaluate the therapeutic index, HT29 and SF767 cells were grown as xenografts in nude mice and the tumor growth rate after treatment with BCNU alone was compared with the rate after treatment with O6-benzylguanine and BCNU. Treatment was administered i.p. when tumors reached 100-200 mm3. For animals bearing HT29 xenografts that were treated with 60 mg/kg O6-benzylguanine 1 h prior to 20 mg/kg BCNU, the average time for tumor volume to increase by 200% was 25 days, compared to 10 days for animals treated with 20 mg/kg BCNU alone. For animals bearing SF767 xenografts, the tumor growth of controls was not significantly different from that of animals treated with O6-benzylguanine alone or BCNU alone up to the maximally tolerated dose (50 mg/kg). For these 3 groups, the average time for tumors to reach 300 mm3 was 9-12 days. However, when animals were treated with 80 mg/kg O6-benzylguanine 1 h prior to receiving 20 mg/kg BCNU tumor size did not increase for at least 21 days. Our studies demonstrate that the therapeutic index of BCNU can be increased when given in combination with O6-benzylguanine.


Assuntos
Carmustina/farmacologia , Neoplasias do Colo/tratamento farmacológico , DNA de Neoplasias/efeitos dos fármacos , Guanina/análogos & derivados , Lomustina/farmacologia , Animais , Neoplasias do Colo/genética , DNA/efeitos dos fármacos , DNA de Cadeia Simples/efeitos dos fármacos , Resistência a Medicamentos , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Feminino , Guanina/farmacologia , Humanos , Camundongos , Camundongos Nus , Transplante Heterólogo , Células Tumorais Cultivadas
3.
Cancer Res ; 51(13): 3367-72, 1991 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-1647266

RESUMO

The effect of O6-benzylguanine, O6-(p-chlorobenzyl)guanine, and O6-(p-methylbenzyl)guanine on the sensitivity of various human tumor cell lines to alkylating agents is evaluated. The sensitivity of human colon tumor cells, HT29, to the chloroethylating agents, 1,3-bis(2-chloroethyl)-1-nitrosourea, 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, 2-chloroethyl(methylsulfonyl) methanesulfonate (clomesone), and chlorozotocin was increased by pretreatment for 2 h with 25 microM of each analogue. O6-Benzylguanine was slightly more effective as a sensitizer in HT29 cells than the p-chlorobenzyl and p-methylbenzyl analogues. However, all analogues sensitized SF767 glioma cells to the cytotoxic effects of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, 1,3-bis(2-chloroethyl)-1-nitrosourea, and clomesone to the same degree. Both cell lines were sensitized to the methylating agents streptozotocin and 5-(3-methyl-1-triazeno)imidazole-4-carboxamide, the active intermediate of 5-(3,3-dimethyl-1-triazenyl)imidazole-4-carboxamide, by pretreatment with 10 microM O6-benzylguanine for 2 h. The number of Raji cells surviving 50 microM clomesone decreased 3-fold upon pretreatment for 2 h with 1 microM O6-benzylguanine. The degree of enhancement was dependent on the amount of alkyltransferase protein present in cell lines. For example, HT29 cells (alkyltransferase activity, 381 fmol/mg protein) exhibited a greater degree of enhancement when treated with O6-benzylguanine than SF767 (77 fmol/mg protein) and M19-MEL melanoma (36 fmol/mg protein) cells. There was no enhancement observed in mer- cell lines, U251 (less than 2 fmol/mg protein), and BE (3 fmol/mg protein), or with alkylating agents which did not produce a cytotoxic lesion at the O6 position of guanine in DNA such as cisplatin or 4-hydroperoxycyclophosphamide. Our studies suggest that O6-benzylguanine analogues may have utility in mer+ tumors as an adjuvant to a variety of alkylating agents which produce a toxic lesion at the O6 position of guanine.


Assuntos
Alquilantes/administração & dosagem , Antineoplásicos/administração & dosagem , Guanina/análogos & derivados , Carmustina/administração & dosagem , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/administração & dosagem , Ciclofosfamida/administração & dosagem , Ciclofosfamida/análogos & derivados , DNA/química , Dano ao DNA , Sinergismo Farmacológico , Guanina/administração & dosagem , Humanos , Técnicas In Vitro , Lomustina/administração & dosagem , Mesilatos/administração & dosagem , Metiltransferases/metabolismo , O(6)-Metilguanina-DNA Metiltransferase , Estreptozocina/administração & dosagem , Estreptozocina/análogos & derivados , Células Tumorais Cultivadas/efeitos dos fármacos
4.
J Clin Oncol ; 17(10): 3333-55, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10506637

RESUMO

PURPOSE: Because toxicities associated with chemotherapy and radiotherapy can adversely affect short- and long-term patient quality of life, can limit the dose and duration of treatment, and may be life-threatening, specific agents designed to ameliorate or eliminate certain chemotherapy and radiotherapy toxicities have been developed. Variability in interpretation of the available data pertaining to the efficacy of the three United States Food and Drug Administration-approved agents that have potential chemotherapy- and radiotherapy-protectant activity-dexrazoxane, mesna, and amifostine-and questions about the role of these protectant agents in cancer care led to concern about the appropriate use of these agents. The American Society of Clinical Oncology sought to establish evidence-based, clinical practice guidelines for the use of dexrazoxane, mesna, and amifostine in patients who are not enrolled on clinical treatment trials. METHODS: A multidisciplinary Expert Panel reviewed the clinical data regarding the activity of dexrazoxane, mesna, and amifostine. A computerized literature search was performed using MEDLINE. In addition to reports collected by individual Panel members, all articles published in the English-speaking literature from June 1997 through December 1998 were collected for review by the Panel chairpersons, and appropriate articles were distributed to the entire Panel for review. Guidelines for use, levels of evidence, and grades of recommendation were reviewed and approved by the Panel. Outcomes considered in evaluating the benefit of a chemotherapy- or radiotherapy-protectant agent included amelioration of short- and long-term chemotherapy- or radiotherapy-related toxicities, risk of tumor protection by the agent, toxicity of the protectant agent itself, quality of life, and economic impact. To the extent that these data were available, the Panel placed the greatest value on lesser toxicity that did not carry a concomitant risk of tumor protection. RESULTS AND CONCLUSION: Mesna: (1) Mesna, dosed as detailed in these guidelines, is recommended to decrease the incidence of standard-dose ifosfamide-associated urothelial toxicity. (2) There is insufficient evidence on which to base a guideline for the use of mesna to prevent urothelial toxicity with ifosfamide doses that exceed 2.5 g/m(2)/d. (3) Either mesna or forced saline diuresis is recommended to decrease the incidence of urothelial toxicity associated with high-dose cyclophosphamide use in the stem-cell transplantation setting. Dexrazoxane: (1) The use of dexrazoxane is not routinely recommended for patients with metastatic breast cancer who receive initial doxorubicin-based chemotherapy. (2) The use of dexrazoxane may be considered for patients with metastatic breast cancer who have received a cumulative dosage of 300 mg/m(2) or greater of doxorubicin in the metastatic setting and who may benefit from continued doxorubicin-containing therapy. (3) The use of dexrazoxane in the adjuvant setting is not recommended outside of a clinical trial. (4) The use of dexrazoxane can be considered in adult patients who have received more than 300 mg/m(2) of doxorubicin-based therapy for tumors other than breast cancer, although caution should be used in settings in which doxorubicin-based therapy has been shown to improve survival because of concerns of tumor protection by dexrazoxane. (5) There is insufficient evidence to make a guideline for the use of dexrazoxane in the treatment of pediatric malignancies, with epirubicin-based regimens, or with high-dose anthracycline-containing regimens. Similarly, there is insufficient evidence on which to base a guideline for the use of dexrazoxane in patients with cardiac risk factors or underlying cardiac disease. (6) Patients receiving dexrazoxane should continue to be monitored for cardiac toxicity. Amifostine: (1) Amifostine may be considered for the reduction of nephrotoxicity in patients receiving cisplatin-based chemoth


Assuntos
Amifostina/uso terapêutico , Fármacos Cardiovasculares/uso terapêutico , Mesna/uso terapêutico , Substâncias Protetoras/uso terapêutico , Protetores contra Radiação/uso terapêutico , Razoxano/uso terapêutico , Adulto , Antineoplásicos/efeitos adversos , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/radioterapia , Radioterapia/efeitos adversos
5.
Neurobiol Aging ; 2(2): 143-7, 1981.
Artigo em Inglês | MEDLINE | ID: mdl-6170904

RESUMO

Correlative data were obtained on RNA levels of cerebrocortical neurons, adrenal fasciculate cell RNA content and serum corticosterone levels in 10, 40 and 100 week old male C57BL/6J mice immediately following a 30 interval of continuous noise stimulation (100 dB re 2 x 10(-5) N/m2, 0.35-20 kHz) and at 1 hr and 4 hr recovery intervals. Quantification of cellular RNA levels entailed use of scanning-integrating microdensitometry of azure B stained tissue sections. Hormonal analyses were done by radioimmunoassay. Noise stimulation induced a mild to moderate adrenocortical activation and a moderate elevation of serum corticosterone levels in all age groups. Noise exposure also resulted in an increase in the RNA content of cerebrocortical neurons. However, maximal neuronal RNA levels proved to be considerably lower (32-36%) in 100 week old mice as compared to both 10 and 40 week old mice during the post-exposure intervals. The overall data support the existence of a lower neuronal capacity for sensory induced RNA synthesis in 100 week old mice. The data also suggest that age dependent differences in neuronal responsiveness are not directly related to the extent of adrenal RNA activation or to a lower availability of circulating glucocorticoids.


Assuntos
Envelhecimento , Química Encefálica , Ruído/efeitos adversos , RNA/análise , Estresse Fisiológico/metabolismo , Córtex Suprarrenal/análise , Animais , Encéfalo/patologia , Córtex Cerebral/análise , Corticosterona/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/análise
6.
Mech Ageing Dev ; 17(3): 211-23, 1981 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-6172680

RESUMO

Confluent late passage WI-38 human diploid fibroblast cultures grown in the presence or absence of hydrocortisone for fifteen population doublings were measured cytochemically for DNA, nuclear RNA, basic nuclear protein and acidic nuclear protein content during a 12-hour interval following a medium-change stimulation. Radioisotope tracer studies were utilized to assess the effects of prolonged hydrocortisone treatment on protein synthesis and degradation in aging confluent and logarithmically growing cultures. Hydrocortisone-treated cultures exhibited an increased Feulgen--DNA stainability, no difference in basic nuclear protein content, a significantly larger initial decrease followed by an increase in acidic nuclear protein content, and elevated levels of nuclear RNA as compared to untreated controls. Hydrocortisone treatment also resulted in increased incorporation of leucine into protein and decreased breakdown of pre-labeled protein in both confluent and logarithmically growing cultures. These results indicate that many of the metabolic changes associated with proliferation are stimulated by prolonged hydrocortisone treatment of late passage WI-38 fibroblast cells.


Assuntos
Núcleo Celular/metabolismo , Fibroblastos/metabolismo , Hidrocortisona/farmacologia , Ácidos Nucleicos/metabolismo , Proteínas/metabolismo , Divisão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , DNA/metabolismo , Histocitoquímica , Humanos , Cinética , Leucina/metabolismo , RNA/metabolismo
7.
Mech Ageing Dev ; 20(1): 1-12, 1982 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6184578

RESUMO

Cultures of WI-38 fibroblasts maintained in low-serum medium have little mitotic activity. Such arrested cultures can serve as a useful adjunct to the normal-serum proliferating fibroblast model system of senescence since the reduced cycling activity more accurately reflects in vivo conditions. Normal-serum plateau phase cultures and 17-day low-serum arrested plateau phase cultures were examined at both mid and late population doubling levels (PDL). Acidic, basic and total nuclear protein contents were determined by staining with toluidine blue O, alkaline fast green and acid fast green, respectively. Succinate dehydrogenase and glucose-6-phosphate dehydrogenase were localized with the nitroblue tetrazolium staining reaction. Quantification of individual cell staining was done on a Vickers M85 microdensitometer. Low-serum arrested cells at both mid and late PDL showed a significant increase in acidic protein staining and a decrease in basic protein staining when compared with normal-serum nonarrested cells. Enzyme activities in arrested cells were lower than nonarrested cells at mid PDL but equivalent to nonarrested cells at late PDL. This study demonstrates that the use of selected quantitative histochemical staining in combination with cytophotometry can be employed to differentiate arrested from nonarrested fibroblast populations as well as mid PDL from late PDL cultures.


Assuntos
Sangue , Nucleoproteínas/análise , Ciclo Celular , Sobrevivência Celular , Meios de Cultura , Fibroblastos/citologia , Fibroblastos/enzimologia , Glucosefosfato Desidrogenase/metabolismo , Histocitoquímica , Humanos , Interfase , Coloração e Rotulagem , Succinato Desidrogenase/metabolismo
8.
Am J Med ; 85(5): 662-7, 1988 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3189370

RESUMO

PURPOSE: The syndrome of idiopathic hyperammonemia occurs in patients who have received high-dose cytoreductive therapy for the treatment of hematologic malignancy. It is characterized by abrupt alteration in mental status and respiratory alkalosis associated with markedly elevated plasma ammonium levels in the absence of any identifiable cause, and frequently results in intractable coma and death. Our goal was to survey clinical and pathologic manifestations of the disorder and discuss treatment options. PATIENTS AND METHODS: Plasma ammonium levels were measured in patients on the acute leukemia service or on the bone marrow transplant service at The Johns Hopkins Hospital, and a level more than twice normal was considered diagnostic of hyperammonemia. The syndrome was identified in nine patients; in eight, hyperammonemia occurred after administration of intensive cytoreductive therapy that resulted in profound leukopenia. The disorder occurred in the ninth patient two months after allogeneic bone marrow transplantation. RESULTS: Three of the nine patients survived an episode of idiopathic hyperammonemia; one patient subsequently died of leukemia and one of recurrent idiopathic hyperammonemia. The one long-term survivor is currently alive and well without neurologic sequelae 250 days after autologous bone marrow transplantation. CONCLUSION: Because neurologic function can deteriorate rapidly, early recognition of this disorder and close monitoring of the patient's neurologic status are critical.


Assuntos
Amônia/sangue , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Encefalopatias/etiologia , Feminino , Humanos , Leucemia/tratamento farmacológico , Masculino , Transtornos Mentais/etiologia , Pessoa de Meia-Idade , Neutropenia/complicações , Síndrome
9.
Chest ; 111(6): 1769-72, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9187210

RESUMO

OBJECTIVE: To highlight the incidence of subglottic stenosis (SGS) as a complication of surgery for congenital heart disease and the role of single-stage laryngotracheoplasty in treating this complication. DESIGN: Retrospective case series. SETTING: University-based referral center specializing in surgery for congenital heart disease and complex airway problem management. INTERVENTION: Laryngotracheal reconstruction (LTR). MAIN OUTCOME MEASURE: Successful airway expansion. RESULTS: At last follow-up, 87.5% (7 of 8) of patients remain free of obstructive airway symptoms. CONCLUSION: SGS can complicate surgery for congenital heart disease in children. Single-stage LTR is an effective treatment modality for this problem.


Assuntos
Glote , Cardiopatias Congênitas/complicações , Cardiopatias Congênitas/cirurgia , Laringoestenose/etiologia , Complicações Pós-Operatórias/etiologia , Doença Aguda , Pré-Escolar , Feminino , Humanos , Lactente , Intubação Intratraqueal/efeitos adversos , Laringoscopia , Laringoestenose/diagnóstico , Laringoestenose/cirurgia , Masculino , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/cirurgia , Estudos Retrospectivos , Traqueotomia
10.
Cancer Chemother Pharmacol ; 32(1): 59-63, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8462125

RESUMO

We investigated the ability of 5-(dimethyltriazeno)imidazole-4-carboxamide (DTIC, decarbazine) and an analogue, temozolomide, to deplete cells or tumors of O6-alkylguanine-DNA alkyltransferase (AGT) and to enhance the antitumor effects of 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU). Human colon cancer (HT29) cell survival was decreased by almost 1 log when treated with 500 microM temozolomide prior to 150 microM BCNU. Administration of the maximal tolerated dose of DTIC (300 mg/kg) to nude mice carrying HT29 xenografts resulted in complete depletion of AGT activity in tumors at 4 h and 16 h. Administration of 150 mg/kg DTIC caused a 76% reduction in AGT activity at 4 h, but only a 28% reduction at 16 h. The maximally tolerated doses of DTIC and BCNU, alone and in combination, were used to treat nude mice bearing HT29 xenografts. No difference in tumor growth occurred when animals were treated with either BCNU alone (50 mg/kg), DTIC alone (300 mg/kg), DTIC (150 mg/kg) followed by BCNU (12.5 mg/kg), or BCNU (25 mg/kg) followed by DTIC (150 mg/kg). These data suggest that methylating agents such as DTIC may be too toxic to be used in combination with BCNU to deplete tumor alkyltransferase levels effectively and increase the therapeutic index of BCNU.


Assuntos
Carmustina/uso terapêutico , Neoplasias do Colo/tratamento farmacológico , Dacarbazina/análogos & derivados , Dacarbazina/farmacologia , Metiltransferases/metabolismo , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carmustina/administração & dosagem , Dacarbazina/administração & dosagem , Humanos , Metiltransferases/antagonistas & inibidores , Camundongos , Camundongos Nus , Transplante de Neoplasias , O(6)-Metilguanina-DNA Metiltransferase , Temozolomida , Células Tumorais Cultivadas/efeitos dos fármacos
11.
Cancer Chemother Pharmacol ; 34(6): 509-14, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7923562

RESUMO

Depletion of the DNA-repair protein O6-alkylguanine-DNA alkyltransferase (AGT) increases the sensitivity of cells in culture and of human tumor xenografts to chloroethylnitrosoureas such as carmustine (BCNU). We have previously demonstrated that dacarbazine (DTIC) can deplete AGT activity in cells in culture and in human tumor xenografts. A phase I trial of DTIC followed immediately by BCNU was conducted to determine the DTIC dose resulting in maximal depletion of AGT in the peripheral blood mononuclear cells (PBMC) of cancer patients and to determine the maximally tolerated dose of DTIC given as a 4-h infusion immediately prior to a fixed dose of BCNU. A 4-h infusion of DTIC followed by a 2-h infusion of BCNU was given to 42 patients with refractory solid tumors. Complete depletion of AGT activity was not achieved at DTIC doses of up to 750 mg/m2. The dose-limiting toxicity was hematologic, although at higher doses of BCNU (> or = 100 mg/m2) we observed significant nonhematologic toxicity. Our recommended phase II doses are 1,000 mg/m2 DTIC followed by 75 mg/m2 BCNU. AGT activity in PBMC of the 28 patients studied decreased to a mean of 62% +/- 11% (SE) of the baseline value at 4 h after initiation of the DTIC infusion. At 24 h after initiation of the DTIC infusion, AGT activity in PBMC was depleted to a mean of 65% +/- 14% of the baseline value. There was no direct correlation between the DTIC dose and the extent of AGT depletion. Baseline PBMC AGT levels varied widely among patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carmustina/administração & dosagem , Dacarbazina/administração & dosagem , Neoplasias/tratamento farmacológico , Adulto , Idoso , Carmustina/toxicidade , Dacarbazina/toxicidade , Esquema de Medicação , Feminino , Humanos , Masculino , Metiltransferases/metabolismo , Pessoa de Meia-Idade , Monócitos/enzimologia , Neutropenia/induzido quimicamente , O(6)-Metilguanina-DNA Metiltransferase , Trombocitopenia/induzido quimicamente
12.
Laryngoscope ; 107(9): 1267-9, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9292615

RESUMO

Functional endoscopic sinus surgery (FESS) has become the surgical procedure of choice for the treatment of chronic sinusitis that is refractory to medical treatment. It has become routine to perform endoscopy in children under general anesthesia 2 to 3 weeks after FESS to facilitate examination and cleaning of the operative site. We compared the clinical outcome of 50 children who underwent FESS without a second-look endoscopy with 50 children who underwent a routine second look. Patients with systemic disease (cystic fibrosis, immotile ciliary syndrome, immunoglobulin deficiency) or undergoing a revision procedure were excluded from the study. The results show that the postoperative improvement in nasal obstruction, nasal drainage, and chronic cough was the same for both groups. We conclude that in the vast majority of children without systemic disease and not undergoing a revision procedure, a second endoscopic procedure may not offer any apparent advantage.


Assuntos
Endoscopia/métodos , Sinusite/cirurgia , Adolescente , Anestesia Geral , Criança , Pré-Escolar , Doença Crônica , Transtornos da Motilidade Ciliar , Tosse/fisiopatologia , Tosse/cirurgia , Fibrose Cística , Feminino , Seguimentos , Humanos , Imunoglobulinas/deficiência , Masculino , Obstrução Nasal/fisiopatologia , Obstrução Nasal/cirurgia , Período Pós-Operatório , Reoperação , Estudos Retrospectivos , Rinite/fisiopatologia , Rinite/cirurgia , Sinusite/tratamento farmacológico , Sinusite/fisiopatologia , Síndrome , Resultado do Tratamento , Procedimentos Desnecessários
13.
Arch Otolaryngol Head Neck Surg ; 123(7): 681-3, 1997 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9236584

RESUMO

OBJECTIVE: To evaluate the safety of ambulatory adenotonsillectomy in children younger than 3 years. MATERIALS AND METHODS: The records of 102 children younger than 3 years who underwent adenotonsillectomy as an outpatient procedure were reviewed during a 3-year period. RESULTS: Ten patients (10%) required overnight hospital admission for an average of 1.4 days. Nine patients were admitted directly from the day-stay unit and 1 patient was admitted 48 hours after surgery. The reason for hospital admission was poor oral intake. None of the patients had postoperative bleeding or respiratory problems or required intensive care unit admission. CONCLUSION: The safety of ambulatory adenotonsillectomy depends on judicious selection criteria and can be performed in children younger than 3 years.


Assuntos
Adenoidectomia/efeitos adversos , Procedimentos Cirúrgicos Ambulatórios/efeitos adversos , Tonsilectomia/efeitos adversos , Adenoidectomia/estatística & dados numéricos , Procedimentos Cirúrgicos Ambulatórios/estatística & dados numéricos , Pré-Escolar , Feminino , Hospitalização/estatística & dados numéricos , Humanos , Lactente , Masculino , Seleção de Pacientes , Segurança , Tonsilectomia/estatística & dados numéricos , Resultado do Tratamento
14.
Arch Otolaryngol Head Neck Surg ; 123(6): 630-2, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9193226

RESUMO

OBJECTIVE: To highlight the modes of presentation and management of a peritonsillar abscess in children younger than 5 years. DESIGN: Retrospective case series. SETTING: Tertiary referral pediatric otolaryngology practice. PATIENTS: Seven children younger than 5 years. RESULTS: The mean age of the children studied was 27 months (age range, 7-41 months). Five (71%) of the 7 patients underwent computed tomographic scanning to confirm the diagnosis. Pus was cultured at surgery in every case. The most common organism detected was Streptococcus viridans. The average hospital stay was 72 hours (range, 22 hours to 12 days). After diagnosis of an abscess, all patients underwent an electrocautery tonsillectomy and had an uneventful recovery. CONCLUSIONS: Children younger than 5 years who present with poor oral intake, high fever, drooling, and trismus should be suspected of having a peritonsillar abscess. A computed tomographic scan of the neck is usually required to confirm a suspected diagnosis. Prompt diagnosis and treatment will lead to a considerable decrease in morbidity. Immediate tonsillectomy is a safe and effective means of abscess drainage.


Assuntos
Abscesso Peritonsilar/diagnóstico , Abscesso Peritonsilar/cirurgia , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/cirurgia , Pré-Escolar , Eletrocoagulação , Feminino , Humanos , Lactente , Masculino , Abscesso Peritonsilar/microbiologia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X , Tonsilectomia
15.
Med Hypotheses ; 41(2): 115-7, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8231988

RESUMO

Based upon a literature survey, this paper outlines the argument that Treponema pallidum may be the etiologic agent of AIDS. AIDS and syphilis have similar epidemiology, immunology and pathologies. In addition, the current methods of detecting and treating syphilis are inadequate. The similarities between syphilis and AIDS support the need for further research into their relationships, including the role Treponema pallidum may play in AIDS etiology.


Assuntos
Síndrome da Imunodeficiência Adquirida/microbiologia , Sífilis/microbiologia , Treponema pallidum/patogenicidade , Síndrome da Imunodeficiência Adquirida/epidemiologia , Síndrome da Imunodeficiência Adquirida/etiologia , Humanos , Modelos Biológicos , Sífilis/epidemiologia
16.
Int J Pediatr Otorhinolaryngol ; 37(3): 277-81, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8905462

RESUMO

The campomelic syndrome is a rare osteochondrodysplasia which frequently leads to early death from pulmonary insufficiency. We describe a patient with anatomic compromise of the upper airway due to diffuse laryngotracheomalacia and a moderate subglottic stenosis, treated successfully with single-stage laryngotracheal reconstruction using a rib graft. To our knowledge this has not been previously described. A review of the current literature is included.


Assuntos
Doenças da Laringe/cirurgia , Laringe/cirurgia , Osteocondrodisplasias , Traqueia/cirurgia , Doenças da Traqueia/cirurgia , Obstrução das Vias Respiratórias/etiologia , Obstrução das Vias Respiratórias/cirurgia , Face/anormalidades , Fêmur/anormalidades , Humanos , Lactente , Doenças da Laringe/complicações , Laringoestenose/cirurgia , Masculino , Osteocondrodisplasias/complicações , Osteocondrodisplasias/cirurgia , Síndrome , Doenças da Traqueia/complicações
17.
Int J Pediatr Otorhinolaryngol ; 52(1): 45-51, 2000 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-10699239

RESUMO

OBJECTIVES: Outcome analyses of factors that may either maximize success or predict a better outcome following choanal atresia correction. METHODS: A retrospective review of children undergoing choanal atresia correction at Great Ormond Street Hospital for Children, London between January 1990 and April 1998. Children with unilateral or bilateral choanal atresia were studied. In all cases, correction was by a transnasal approach under endoscopic control. A 120 degrees Hopkins rod telescope was used to visualize the atretic plate from the nasopharynx. Straight urethral sounds were used to perforate the plate followed by use of an air drill to remove the bony component. Portex endotracheal tubes were subsequently inserted as nasal stents. RESULTS: Sixty-five children (19 M, 46 F: age range 1 day to 17 years) presented with choanal atresia and the outcomes for 46 were included in the study. Twenty-six patients (40%) had other major anomalies. In children with unilateral atresia neither duration of stenting nor presence of facial anomalies had an impact on outcome. Of those children with bilateral choanal atresia and associated facial anomalies (n=9), 56% were asymptomatic following correction. In children with isolated bilateral choanal atresia (n=19), 74% were asymptomatic following correction; 29% (n2.3 kg (n3. 5 mm (n=6) had an 83% chance of a good outcome. Those patients stented with a tube

Assuntos
Atresia das Cóanas/cirurgia , Procedimentos Cirúrgicos Otorrinolaringológicos/instrumentação , Stents , Adolescente , Criança , Pré-Escolar , Atresia das Cóanas/diagnóstico , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Procedimentos Cirúrgicos Otorrinolaringológicos/métodos , Estudos Retrospectivos , Resultado do Tratamento , Reino Unido
18.
Int J Pediatr Otorhinolaryngol ; 38(3): 247-54, 1997 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-9051429

RESUMO

A medial subperiosteal abscess (SPA) of the orbit is the most common serious complication of sinusitis in children. The distinction between SPA and the more benign pre-septal disease is difficult to make especially in a young child in whom an ophthalmological evaluation is often difficult. Computerised tomography (CT) is the investigation of choice in making this distinction. Subperiosteal inflammatory disease of the orbit is initially treated with intravenous antibiotic therapy with surgery reserved for those patients who do not respond to medical treatment and in whom a medial SPA is confirmed by CT. Conventionally, the abscess is drained via an external incision and an ethmoidectomy is performed at the same time. More recently, successful drainage of SPA's has been accomplished endoscopically via a intranasal approach with less morbidity and superior cosmesis. We present a 5 year experience of 24 patients with CT scans suggestive of medial SPA who underwent endoscopic exploration of the medial subperiosteal orbital space. We discuss the current management of medial subperiosteal disease of the orbit in children and include a review of the literature. Also included is a clinical staging system which aids the management of orbital complications of sinusitis.


Assuntos
Abscesso/fisiopatologia , Abscesso/cirurgia , Órbita/fisiopatologia , Abscesso/etiologia , Adolescente , Criança , Pré-Escolar , Endoscopia , Feminino , Humanos , Masculino , Sinusite/complicações , Tomografia Computadorizada por Raios X
19.
Ann R Coll Surg Engl ; 78(5): 440-3, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8881727

RESUMO

There is concern about the burden day-stay surgery created upon community services. We have followed 128 children and 38 adults undergoing day-stay tonsillectomy and a similar cohort of adults and children undergoing tonsillectomy as inpatients and looked at the demands made on general practice and casualty services over the 2 weeks after discharge. Twelve adults (18%) and four children (3%) required overnight admission after day-stay surgery. Within the first 2 weeks, 27 adults (48.2%) and 62 children (50%) visited their GP and 13 adults (23.2%) and six children (4.8%) visited the casualty department. There was no statistically significant difference for either adults or children when comparing the day-stay and inpatient cohorts. Adult day-stay tonsillectomy is associated with a high admission rate. Both adult and paediatric tonsillectomy lead to considerable demand for general practice and casualty services, but this demand is high regardless of whether the day-stay or inpatient route is chosen.


Assuntos
Procedimentos Cirúrgicos Ambulatórios , Serviços de Saúde Comunitária/estatística & dados numéricos , Hospitalização , Tonsilectomia/métodos , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Serviço Hospitalar de Emergência/estatística & dados numéricos , Medicina de Família e Comunidade/estatística & dados numéricos , Seguimentos , Humanos , Londres , Estudos Prospectivos
20.
J Laryngol Otol ; 111(2): 106-8, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9102431

RESUMO

The surgical closure of dry tympanic membrane perforations in children remains a controversial issue due to conflicting opinions on the appropriate technique, graft material and success rate. We present a review of 342 children who underwent fat graft myringoplasty as a day-stay procedure over a six-year period. Successful closure of the tympanic membrane perforation was achieved in 92 per cent of ears. Subsequent recurrent otitis media with effusion required insertion of ventilation tubes in 12 per cent. No relationship was observed between the age of the child and a successful outcome. We conclude that day-stay fat graft myringoplasty is a safe and successful procedure which results in a dry and safe ear in the majority of children.


Assuntos
Tecido Adiposo/transplante , Procedimentos Cirúrgicos Ambulatórios , Miringoplastia/métodos , Perfuração da Membrana Timpânica/cirurgia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Estudos Retrospectivos , Resultado do Tratamento
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