RESUMO
Color can be used to group similar elements, and ensemble percepts of color can be formed for such groups. In real-life settings, however, elements of similar color are often spatially interspersed among other elements and seen against a background. Forming an ensemble percept of these elements would require the segmentation of the correct color signals for integration. Can the human visual system do this? We examined whether observers can extract the ensemble mean hue from a target hue distribution among distractors and whether a color category boundary between target and distractor hues facilitates ensemble hue formation. Observers were able to selectively judge the target ensemble mean hue, but the presence of distractor hues added noise to the ensemble estimates and caused perceptual biases. The more similar the distractor hues were to the target hues, the noisier the estimates became, possibly reflecting incomplete or inaccurate segmentation of the two hue ensembles. Asymmetries between nominally equidistant distractors and substantial individual variability, however, point to additional factors beyond simple mixing of target and distractor distributions. Finally, we found no evidence for categorical facilitation in selective ensemble hue formation.
Assuntos
Percepção de Cores , Estimulação Luminosa , Humanos , Percepção de Cores/fisiologia , Estimulação Luminosa/métodos , Adulto , Adulto Jovem , Atenção/fisiologia , Feminino , MasculinoRESUMO
Carbon dioxide (CO2) emissions are an important environmental issue that causes greenhouse and climate change effects on the earth. Nowadays, CO2 has various conversion methods to be a potential carbon resource, such as photocatalytic, electrocatalytic, and photo-electrocatalytic. CO2 conversion into value-added products has many advantages, including facile control of the reaction rate by adjusting the applied voltage and minimal environmental pollution. The development of efficient electrocatalysts and improving their viability with appropriate reactor designs is essential for the commercialization of this environmentally friendly method. In addition, microbial electrosynthesis which utilizes an electroactive bio-film electrode as a catalyst can be considered as another option to reduce CO2. This review highlights the methods which can contribute to the increase in efficiency of carbon dioxide reduction (CO2R) processes through electrode structure with the introduction of various electrolytes such as ionic liquid, sulfate, and bicarbonate electrolytes, with the control of pH and with the control of the operating pressure and temperature of the electrolyzer. It also presents the research status, a fundamental understanding of carbon dioxide reduction reaction (CO2RR) mechanisms, the development of electrochemical CO2R technologies, and challenges and opportunities for future research.
Assuntos
Desequilíbrio Ácido-Base , Dióxido de Carbono , Humanos , Bicarbonatos , Mudança Climática , Planeta TerraRESUMO
Color serves both to segment a scene into objects and background and to identify objects. Although objects and surfaces usually contain multiple colors, humans can readily extract a representative color description, for instance, that tomatoes are red and bananas yellow. The study of color discrimination and identification has a long history, yet we know little about the formation of summary representations of multicolored stimuli. Here, we characterize the human ability to integrate hue information over space for simple color stimuli varying in the amount of information, stimulus size, and spatial configuration of stimulus elements. We show that humans are efficient at integrating hue information over space beyond what has been shown before for color stimuli. Integration depends only on the amount of information in the display and not on spatial factors such as element size or spatial configuration in the range measured. Finally, we find that observers spontaneously prefer a simple averaging strategy even with skewed color distributions. These results shed light on how human observers form summary representations of color and make a link between the perception of polychromatic surfaces and the broader literature of ensemble perception.
Assuntos
Percepção de Cores/fisiologia , Visão de Cores , Cor , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Software , Adulto JovemRESUMO
BACKGROUND: Patient-centred care (PCC) has been associated with improved patient satisfaction outcomes in a variety of clinical settings. There is a paucity of research addressing the concept of PCC in an occupational medicine context. AIMS: To assess patient perception and compare physician and patient perceptions of patient centredness of the care at a specialty occupational medicine clinic. METHODS: An observational study design using the Patient Perception of Patient Centeredness Questionnaire (PPPC) at an ambulatory tertiary care occupational health clinic. Results were analysed using a standardized coding system. Summary scores were compared to results reported in a primary care setting. Patient and physician scores were compared to detect physician-patient differences in perceived patient centredness of care. RESULTS: Of 47 eligible patients 37 consented to participate and seven were excluded due to incomplete data. Summary scores of patient perceptions of patient centredness were similar but somewhat better than scores reported in a primary care setting. Perceived patient centredness of care was high and there was minimal discordance between patient and physician scores. CONCLUSIONS: This study demonstrated that PCC can be measured in an occupational health setting. In an ambulatory tertiary care occupational health clinic there was a high degree of patient centredness of care which may be explained by a variety of factors. Future research should consider whether similar findings exist in other occupational medicine practice settings.
Assuntos
Medicina do Trabalho/métodos , Assistência Centrada no Paciente , Adulto , Atitude do Pessoal de Saúde , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Relações Médico-Paciente , Indicadores de Qualidade em Assistência à Saúde , Inquéritos e QuestionáriosRESUMO
INTRODUCTION: Lynch Syndrome (LS) is a genetically inherited autosomal disorder that increases the risk of many types of cancer, especially colorectal cancer (CRC). Identifying these subjects improves morbidity and mortality. We aimed to assess the prevalence of LS with both clinical criteria and universal strategy in Mashhad, Iran. METHODS: In this retrospective study, we screened 322 patients with CRC between 2013 and 2016 in Mashhad, Iran. CRCs were screened based on Amsterdam II criteria, revised Bethesda guideline, and universal strategy. Information regarding the clinical criteria was obtained by interviewing the patients or, their families. Tumors were screened by pathologists with IHC staining of four Mismatch repair (MMR) proteins (MLH1, MSH2, MSH6, and PMS2). Tumors with absent IHC staining of MLH1 were tested for BRAF mutations to exclude sporadic CRCs. RESULTS: Of 322 CRCs, 33 cases were found to be deficient-MMR; 22 of these had concurrent loss of MLH1 and PMS2, followed by concurrent loss of MSH2 and MSH6 in 8 CRCs. Twenty-two cases with a loss of MLH1 underwent testing for the BRAF mutation, 4 of which were recognized as a positive BRAF mutation. Finally, 29 CRCs were found as being positive screen for LS. Poor sensitivity (21.74%) was found for the Amsterdam II criteria and a poor positive predictive value (15.39%) for the revised Bethesda. CONCLUSION: Application of clinical criteria may not be effective enough to identify LS and at least 2-antibody panel (PMS2, MSH6) should be conducted for newly diagnosed CRCs.
Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Testes Genéticos , Programas de Rastreamento , Adulto , Idoso , Neoplasias Colorretais Hereditárias sem Polipose/genética , Proteínas de Ligação a DNA/genética , Feminino , Predisposição Genética para Doença , Humanos , Irã (Geográfico) , Masculino , Pessoa de Meia-Idade , Guias de Prática Clínica como Assunto , Proteínas Proto-Oncogênicas/genética , Estudos RetrospectivosRESUMO
Extracts of the human glioma cell line A1235 (lacking O(6)-methylguanine-DNA methyltransferase) are known to restore a G:T mismatch to a normal G:C pair in a G:T-containing model (45 bp) DNA substrate. Herein we demonstrate that substitution of G:T with O(6)-methylguanine:T (m6G:T) results in extract-induced intra-strand incision in the DNA at an efficiency comparable to that of complete repair of the G:T-containing substrate, although the m6G:T mispair serves as a poor substrate for later repair steps (e.g. gap filling, as judged by defective DNA repair synthesis). The A1235 extract, when supplemented with ATP and the four normal dNTPs, incises 5' to the mismatched T, as inferred by the generation of a single-stranded 20mer fragment. Unlike its parental (A1235) counterpart, an extract of the alkylation-tolerant derivative cell line A1235-MR4 produces no 20mer fragment, even when thymine-DNA glycosylase (TDG) is added to the reaction mixture. In contrast, the A1235 extract, when augmented with TDG, catalyzes enhanced incision at m6G:T in the 45 bp DNA, yielding 5-10-fold greater 20mer than that of either extract or TDG alone. Interestingly, the absence of m6G:T incision activity in the A1235-MR4 extract is similar to that seen for extracts of several known mismatch repair-deficient cell lines of colon tumor origin. Together these results suggest that derivative A1235-MR4 cells are defective in m6G:T incision activity and that the efficiency of this activity in the parental (A1235) cells may depend on the presence of several ill-defined mismatch repair recognition proteins along with TDG and ATP.
Assuntos
Pareamento Incorreto de Bases/genética , Reparo do DNA , DNA/metabolismo , Trifosfato de Adenosina/farmacologia , Sequência de Bases , Extratos Celulares , Sistema Livre de Células/efeitos dos fármacos , Sistema Livre de Células/metabolismo , DNA/química , DNA/genética , Desoxirribonuclease (Dímero de Pirimidina) , Relação Dose-Resposta a Droga , Endodesoxirribonucleases/efeitos dos fármacos , Endodesoxirribonucleases/metabolismo , Endodesoxirribonucleases/farmacologia , Guanina/análogos & derivados , Guanina/química , Guanina/metabolismo , Células HT29 , Humanos , Mutação , Nucleotídeos/farmacologia , Especificidade por Substrato , Timina/química , Timina/metabolismo , Células Tumorais CultivadasRESUMO
From January 1993 to March 1995, 162 patients with osteosarcoma of extremities were treated according to the IOR/OS-4 protocol. 133 patients had localised disease, while 29 had metastases at diagnosis. These last patients were simultaneously operated upon for their primary and metastatic lesions. Chemotherapy consisted preoperatively of two cycles of high dose methotrexate (HDMTX) and one cycle each of cisplatin (CDP)-doxorubicin (ADM), CDP/ifosfamide (IFO) and IFO/ADM. After surgery, patients were treated with the aforementioned drugs used as single agents. The mean follow-up of all patients was 6.5 years (5.5-8 years). Surgery was a limb salvage in 94% of cases, and the 5-year event-free survival (EFS) and overall survival (OS) rates were 56 and 71% for patients with localised disease, and 17 and 24% for patients with metastases at diagnosis. These results did not differ from those achieved in our previous study (IOR/OS-3) in which IFO was used only postoperatively in poor responders.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Osteossarcoma/tratamento farmacológico , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Neoplasias Ósseas/cirurgia , Quimioterapia Adjuvante , Intervalo Livre de Doença , Extremidades , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Osteossarcoma/secundário , Osteossarcoma/cirurgia , Taxa de Sobrevida , Resultado do TratamentoRESUMO
We report the long-term orthopaedic and functional results of segmental spinal instrumentation and fusion in 30 Duchenne patients. Twenty-nine had a mean 59% correction of scoliosis with post-operative immobilization in a brace of only three months on average and with a very limited loss of correction over time. One died after cardiac arrest. The mean vital capacity preoperatively was 57 +/- 17% with a decrease to 34 +/- 13% at 3.9 +/- 2 yr after surgery. The sitting position, aesthetic improvement and the quality of life after spinal fusion have been positively evaluated by the large majority of the patients and their parents. Head control was lost in the 14 patients who developed a more severe extension contracture of the neck measured as a significantly longer chin-sternum distance. More than 90% would have the operation or would give their consent again for their son having the operation.
Assuntos
Distrofias Musculares/cirurgia , Fusão Vertebral , Adolescente , Adulto , Criança , Seguimentos , Hemodinâmica/fisiologia , Humanos , Masculino , Distrofias Musculares/complicações , Distrofias Musculares/fisiopatologia , Qualidade de Vida , Testes de Função Respiratória , Escoliose/etiologia , Escoliose/cirurgia , Capacidade VitalRESUMO
Three interviewers, working in pairs and using the Diagnostic Interview for Borderlines (DIB), interviewed three samples of 10 adult psychiatric inpatients. The two members of each interviewer pair alternated in the role of interviewer. Each member of the interviewer pairs completed the interview schedule and scored the protocol according to the instructions provided by the authors of the DIB. Interrater reliability was determined for each interviewer pair using the Kappa statistic. Reliability values were at about the level reported recently by Spitzer, Forman, and Nee (1979) for DSM-III axis I diagnoses in general. Additional statistical analyses were performed to determine whether there were patient sex differences on DIB scores, whether the two male interviewers differed from the female interviewer in their ratings of male or female patients, and whether experience differences among the three interviewers were reflected in their rating of patients. Among the latter analyses, the only significant finding was that in the interviewer pair consisting of a very experienced male psychiatrist and a male first year psychology graduate student, the former rated male patients as less borderline than did the latter. No other difference was found among raters, or between sex of patient and interviewer sex or amount of clinical experience. It was concluded that the DIB is sufficiently reliable for use in clinical research.
Assuntos
Transtorno da Personalidade Borderline/diagnóstico , Transtornos da Personalidade/diagnóstico , Escalas de Graduação Psiquiátrica , Adolescente , Adulto , Idoso , Competência Clínica , Feminino , Humanos , Entrevista Psicológica , Masculino , Pessoa de Meia-IdadeRESUMO
An ongoing study in our laboratories is to examine the relationship of DNA repair defects to human cancer. Our underlying hypothesis has been that human tumors may arise that lack interesting DNA repair pathways if these pathways are important in preventing cancer. In this study, we found that the UV-irradiated adenoviruses showed hypersensitivity when assayed on monolayers of certain human colon tumor cell lines, including three that are reported to have defects in long patch DNA mismatch repair genes and one with no reported defect in mismatch repair. The survival curves showed two components. The first sensitive component was characteristic of 77-95% of the infections depending upon the cell line and the experiment and had an average slope indicating 4.8-fold hypersensitivity to UV. The average of the second-component slopes indicated that the remainder of the infections was accompanied by near-normal repair. Although the value of the first component indicated that the colon tumor lines supported the growth of UV-damaged adenoviruses poorly, the cell lines themselves showed the same post-UV colony-forming ability as did normal human fibroblasts, and their ability to support the growth of N-methyl-N'-nitro-N-nitrosoguanidine-damaged adenoviruses was normal, i.e. it parallelled their ability to repair O6-methylguanine in vitro. We previously observed two-component survival curves when assaying UV-irradiated adenovirus on monolayers of all of seven strains of fibroblasts from Cockayne's syndrome patients. By contrast, single-component curves have been obtained using 21 strains of normal human fibroblasts and seven other tumor lines. We interpret the two-component survival curves in terms of the defective transcription-coupled repair of UV-induced DNA damage that is characteristic both of Cockayne's and certain colon tumor cell lines. In addition, four mismatch repair-deficient colon tumor lines were resistant to killing by elevated levels of dG.
Assuntos
Neoplasias do Colo/metabolismo , Reparo do DNA , Adenovírus Humanos/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Dano ao DNA , Desoxiguanosina/farmacologia , Humanos , Fotobiologia , Células Tumorais Cultivadas , Raios UltravioletaRESUMO
One hundred and forty-four patients with osteosarcoma of the extremity treated with neoadjuvant chemotherapy at the authors' institution between 1986 and 1989 were retrospectively analyzed to evaluate the relationship between the dose-intensity of chemotherapy actually received (RDI) and the prognosis. Preoperative chemotherapy consisted of high-dose methotrexate i.v., cisplatin i.a., and doxorubicin i.v. After surgery "good responder" patients (90% or more tumor necrosis) had a 31-weeks of chemotherapy with the same drugs, while "poor responder" patients (less than 90% tumor necrosis) received a 40 weeks treatment with ifosfamide and etoposide added to the three drugs used preoperatively. Due to delays and dose-reductions, only 17 patients (12%) received the treatment exactly as scheduled by the protocol, 66 (46%) received a dose-intensity between 90 and 99%, and 61 (42%) a dose-intensity between 63 and 89%. At a follow-up ranging between 10 and 13 years, 97 patients (67%) remained continuously free of disease, 45 relapsed, and two died of doxorubicin-induced cardiopathy. The continuous disease-free survival (CDFS) was not related to patients' gender and age, tumor histology, site and size, serum value of alkaline phosphatase, type of surgery and histologic response to chemotherapy. According to the RDI, CDFS resulted significantly higher for those 81 patients who received 90% or more of the scheduled dose-intensity than for those 61 who had less than 90% of the scheduled dose-intensity (76.5% v.s. 57.3%; p<0.02). These results seem to suggest that in neoadjuvant treatment of osteosarcoma the dose-intensity of chemotherapy is crucial for outcome, therefore every effort should be made to avoid reductions of doses and/or delays in performing the cycles of chemotherapy.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Femorais/tratamento farmacológico , Osteossarcoma/tratamento farmacológico , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Cisplatino/administração & dosagem , Terapia Combinada , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Doxorrubicina/administração & dosagem , Feminino , Neoplasias Femorais/mortalidade , Neoplasias Femorais/cirurgia , Seguimentos , Humanos , Masculino , Metotrexato/administração & dosagem , Terapia Neoadjuvante , Osteossarcoma/mortalidade , Osteossarcoma/cirurgia , Cuidados Pré-Operatórios , Taxa de Sobrevida , Resultado do TratamentoRESUMO
PURPOSE: To evaluate the reliability and validity of a portable instrument for measuring macular pigment optical density. METHODS: The instrument is small, uses light emitting diodes as light sources and the principles of heterochromatic flicker photometry of comparing foveal and extra-foveal minimum flicker matches. It uses central fixation for the extra-foveal matches, which subjects found easier than eccentric fixation. Subjects with healthy eyes used the instrument to measure their pigment density in a number of eye clinics. RESULTS: The mean pigment density in 124 eyes in 124 individuals was 0.41 +/- 0.16 (mean +/- SD), there was no significant change with age but the density was less in females, those with light irides, smokers, subjects on diets low in precursor carotenoids and in those exposed to several hours of daylight every day or who used sun beds. CONCLUSIONS: The portable instrument gave valid and reliable data that confirmed published values for macular pigment. It was convenient to use in the clinic and has potential as a screening tool.
Assuntos
Oftalmologia/instrumentação , Retina/química , Pigmentos da Retina/análise , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas de Diagnóstico Oftalmológico/instrumentação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos TestesRESUMO
The authors review their lengthy experience in treating high grade osteosarcoma of the extremity. During the past 20 years many advances have been made in treating high grade osteosarcoma of the extremity. Twenty years ago, in spite of amputation, most patients with this tumor died, whereas today most are cured and amputation is avoided. These advances are mainly due to the development of effective adjuvant and neoadjuvant chemotherapy regimens. This review reports on the progress and controversies in the treatment of osteosarcoma.
Assuntos
Neoplasias Ósseas/tratamento farmacológico , Neoplasias Ósseas/cirurgia , Osteossarcoma/tratamento farmacológico , Osteossarcoma/cirurgia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Quimioterapia Adjuvante , Terapia Combinada , Extremidades , Humanos , Metástase Neoplásica/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Recidiva Local de Neoplasia/cirurgiaRESUMO
With the intention of starting an international protocol between Italy and Scandinavia on neoadjuvant treatment of extremity osteosarcoma using the four active drugs at maximum doses (doxorubicin 75 mg/m2 pre-operatively, and 90 mg/m2 post-operatively, cisplatin 120 mg/m2, methotrexate 12 g/m2, and ifosfamide 15 g/m2), a single center (the Rizzoli institute) performed a pilot study to closely monitor toxicity, safety, and tumor necrosis. Only 7 patients (10%) had a reduced number of the scheduled cycles. A total of 1,050 of the expected 1,076 cycles (98%) were administered. Delays and dose reduction were minimal, leading to a mean received dose intensity of 89%. Limb salvage surgery was performed in 59 cases (87%), with 6 amputations and 3 rotation plasties. Chemotherapy-induced necrosis higher than 95% was observed in 38 patients (56%). Eleven patients had total necrosis (16%). At a median follow-up of 60 months (range 50-65 months), 53 patients (73%) were continuously disease-free. Six of the relapsed patients were rescued with further treatments leading to an overall survival of 87%. Hematological toxicity was remarkable despite the use of G-CSF and hospitalization due to febrile neutropenia occurred in 25 patients (37%). Platelet transfusions were required in 77 of the 194 episodes of grade 4 thrombocytopenia, but no case of major bleeding was observed. Red blood cell transfusions were necessary in all patients (in 15 cases perioperatively only). Non-hematological toxicity comprised grade 1-2 nephrotoxicity in 3 cases, CNS toxicity in 2 cases, and dilata- tive cardiopathy leading to heart transplantation in 1 case. In conclusion, the pilot study was feasible in the vast majority of cases with toxicity not superior to that of the previous protocols where chemotherapy was given in lower doses. The rate of limb salvage procedures, event-free survival and overall survival seemed to be higher than in previous protocols. On the basis of this study, in March 1997 the Italian and Scandinavian Sarcoma Groups started a new protocol for osteosarcoma of the extremities.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Ósseas/tratamento farmacológico , Osteossarcoma/tratamento farmacológico , Adolescente , Adulto , Neoplasias Ósseas/patologia , Condrócitos/efeitos dos fármacos , Condrócitos/patologia , Cisplatino/administração & dosagem , Intervalo Livre de Doença , Doxorrubicina/administração & dosagem , Extremidades , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/patologia , Seguimentos , Humanos , Ifosfamida/administração & dosagem , Infusões Intra-Arteriais , Infusões Intravenosas , Masculino , Metotrexato/administração & dosagem , Terapia Neoadjuvante , Osteoblastos/efeitos dos fármacos , Osteoblastos/patologia , Osteossarcoma/patologia , Projetos Piloto , Cuidados Pré-Operatórios , Prognóstico , Taxa de SobrevidaRESUMO
Associated chemotherapy (adjuvant or neoadjuvant) means the association of systemic pharmacological therapy to local therapy in the treatment of tumors that, although appearing to still be localized at the time of diagnosis, have a high probability of having already given systemic micrometastases. The purpose of this kind of treatment is that of controlling the micrometastases present, even if they can't be documented, in many tumors. These neoplasms, although still apparently localized, do not achieve healing with the simple removal of the primary tumor, precisely because of the presence of these micrometastases. The current treatment of osteosarcoma (OS) commonly makes use of these therapies. There are different types of OS and they are not indicated in all associated therapies, nor do they provide the same results. We may begin by distinguishing between "high-grade" forms, which have a considerable tendency to early metastasis (about 96% of cases) and "low-grade" forms, generally characterized by local malignancy alone (about 4% of cases). Based on the site on which they occur, OS may be "primary," that is, occurring on apparently normal bone (about 95% of cases) and "secondary," that instead occur on bone that is in some way already changed (as a result of radiation, infarction, Paget's disease, etc.). Based on the site and on the staging, OS can be subdivided into forms of the limbs (75% of cases) and "forms of the axile skeleton" (25% of cases) and in forms that are "still localized" at the time of diagnosis (80% of cases) and in forms "with metastases that are documented at the onset (20% of cases). The present review only concerns primary high-grade OS of the limbs that were not metastatic on diagnosis, representing about 60% of all OS, and it is based on the experience of the Rizzoli Orthopaedic Institute where, between 1983 and 1996, a total of 731 patients were treated by neoadjuvant chemotherapy using five different protocols that were subsequently activated (Table I).
Assuntos
Neoplasias Ósseas/tratamento farmacológico , Extremidades , Osteossarcoma/tratamento farmacológico , Amputação Cirúrgica , Antimetabólitos Antineoplásicos/administração & dosagem , Antimetabólitos Antineoplásicos/uso terapêutico , Antineoplásicos/administração & dosagem , Antineoplásicos/uso terapêutico , Antineoplásicos Alquilantes/administração & dosagem , Antineoplásicos Alquilantes/uso terapêutico , Neoplasias Ósseas/classificação , Neoplasias Ósseas/mortalidade , Neoplasias Ósseas/cirurgia , Quimioterapia Adjuvante , Criança , Cisplatino/administração & dosagem , Cisplatino/uso terapêutico , Ensaios Clínicos como Assunto , Terapia Combinada , Doxorrubicina/administração & dosagem , Doxorrubicina/uso terapêutico , Seguimentos , Humanos , Ifosfamida/administração & dosagem , Ifosfamida/uso terapêutico , Metotrexato/administração & dosagem , Metotrexato/uso terapêutico , Estudos Multicêntricos como Assunto , Terapia Neoadjuvante , Metástase Neoplásica , Osteossarcoma/classificação , Osteossarcoma/mortalidade , Osteossarcoma/cirurgia , Ensaios Clínicos Controlados Aleatórios como Assunto , Análise de Sobrevida , Fatores de TempoRESUMO
Main circulatory (heart frequency, HF, intra-artery pressure, AP ECG) and respiratory (arterial oxyhemoglobin saturation SaO2, end-tidal CO2) arterial gas-analysis (HGA) parameters were recorded continually during cemented hip arthroplasty in 70 consecutive non-selected patients. The use of cement did not cause any change in the parameters obtained in 21 of the cases, reduction in arterial oxygen pressure (PaO2) ranging from 11% to 38% was observed in 44 cases, associated with simultaneous reduction in ETCO2 in 11 cases. The reduction in ETCO2 was an isolated finding in 5 of the patients. AP decreased by more than 10% in only 2 cases and there was arrhythmia in another 2 cases. These findings are strongly suggestive of pulmonary embolism encouraging the hypothesis of gas embolism previously suggested by other authors. In patients with little coronary or pulmonary reserve use of cement means an increased risk of severe hemodynamic complications.
Assuntos
Cimentos Ósseos , Prótese de Quadril , Embolia Pulmonar/etiologia , Idoso , Idoso de 80 Anos ou mais , Cimentos Ósseos/efeitos adversos , Dióxido de Carbono/sangue , Embolia Aérea/sangue , Embolia Aérea/etiologia , Feminino , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Embolia Pulmonar/sangue , Fatores de RiscoRESUMO
The authors evaluate the posterior approach to the cervical spine with the patient in a sitting position for the surgical treatment of neoplasms of the vertebral arch. Advantages and risks, particularly those related to anesthesia, are examined. Two cases in which the sitting position was advantageous are reported.
Assuntos
Cistos Ósseos Aneurismáticos/cirurgia , Vértebras Cervicais/cirurgia , Cordoma/cirurgia , Postura , Neoplasias da Coluna Vertebral/cirurgia , Idoso , Anestesia , Cistos Ósseos Aneurismáticos/diagnóstico por imagem , Criança , Cordoma/diagnóstico por imagem , Feminino , Seguimentos , Humanos , Masculino , Complicações Pós-Operatórias/etiologia , Fatores de Risco , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Fatores de Tempo , Tomografia Computadorizada por Raios XRESUMO
On the basis of the authors' experience in the treatment of 257 skeletal neoplasms of the lumbar spine, the features of back pain, which in 96% of the cases constitutes the first symptom of these diseases, are discussed. The overall clinical aspects firstly depend on the stage of the primary tumor: latent, active, aggressive for benign tumors; intra- and extra-compartmental for malignant tumors. Symptoms may include elements which suggest specific lesions, such as osteoid osteoma, eosinophilic granuloma, aneurysmal bone cyst, or high-grade malignant tumors such as Ewing's sarcoma, while lumbar metastasis from carcinoma do not seem to have distinctive features. Site and localization of the tumor are also important variables. The treatment of neoplastic back pain depends on diagnosis, and cannot be adequate if it is not planned on the basis of a complete preoperative study, taking into account not only surgery, but also adjuvant therapy.
Assuntos
Dor Lombar/diagnóstico , Vértebras Lombares , Neoplasias da Coluna Vertebral/diagnóstico , Adolescente , Adulto , Criança , Terapia Combinada , Humanos , Dor Lombar/etiologia , Dor Lombar/terapia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias da Coluna Vertebral/complicações , Neoplasias da Coluna Vertebral/patologia , Neoplasias da Coluna Vertebral/secundário , Neoplasias da Coluna Vertebral/terapiaRESUMO
A personal experience concerning vertebral excision and resection in a single stage for neoplasm is discussed. The surgery requires anaesthesia of long duration, hemodynamic stability, compensation of significant blood loss, monitoring of heat loss, maintenance without injury of prolonged prone position. Experience, with 24 cases lasting an average of 14.5 hours proves that inhalation or intravenous anaesthesia with a strong analgesic component is satisfactory. Normal heat saving systems reduce intraoperative hypothermia. Transfusion is always abundant, autologous contribution is moderate. Hemodilution is well-tolerated up to Hb 7%; below this amount there may be problems of a hemodynamic and coagulative nature. The quantity and quality of filling is guided by monitoring of pre-loading pressures and availability of oxygen. There were no critical complications; all of the patients left the hospital in good condition.
Assuntos
Anestesia , Neoplasias da Coluna Vertebral/cirurgia , Adulto , Anestesia por Inalação , Anestesia Intravenosa , Transfusão de Sangue , Feminino , Hemodiluição , Hemodinâmica , Humanos , Masculino , Pessoa de Meia-Idade , Monitorização Intraoperatória , Complicações Pós-Operatórias , Fatores de TempoRESUMO
The authors examine 24 patients submitted to resection of the pelvic girdle in neoplastic pathology, illustrating the perioperative anesthesiologic procedures used. Sudden variations in blood and plasma volume and increasing hypothermia constitute the main problems. The prevention of hypothermia and continuous invasive monitoring of hemodynamic parameters and of oxygen saturation in mixed venous blood (SvO2) are of primary importance.