Complicações e taxa de recidiva em pacientes com carcinoma epidermóide da vulva tratadas com vulvectomia radical com uma ou três incisões: estudo de 132 casos

O objetivo deste estudo foi comparar as taxas de complicações pós-operatórias e a taxa de recidiva em 132 mulheres com carcinoma da vulva tratadas com vulvectomia radical e linfadenectomia inguinal bilateral com uma ou três incisões. Foi um ensaio clínico retrospectivo não randomizado, incluindo 65 mulheres operadas por incisão única e 67 por três incisões, entre 1986 e 1996. Para análise estatística foram realizados os testes Exato de Fischer, Qui-Quadrado, t de Student e regressão logística e curvas de sobrevida pelo método de Kaplan-Meyer, comparadas pelo teste de Wilcoxon, seguidas de regressão de Cox, com limite de 5% de significância estatística. Os grupos foram semelhantes com relação à idade, tabagismo, presença de síndromes clínicas, tipo e grau histológico. Pacientes com neoplasia no estadio III foram mais freqüentes no grupo de incisão única e mais linfonodos livres no grupo de três incisões. As pacientes tratadas com três incisões apresentaram significativamente menos complicações pós-operatórias imediatas (76% vs 92%, p<0,05), menos deiscências (72% vs 92%, p<0,01), menor necessidade de procedimentos secundários (76% vs 94%, p<0,01) e menor tempo de internação (média de 19,4 dias vs 38,7 dias, p<0,001). Ocorreram sete óbitos pós-operatórios: cinco no grupo tratado com incisão única e dois com três incisões. A taxa de recidiva foi significativamente menor nas operadas com três incisões (19% vs 35%, p<0,01) e com linfonodos livres de doença (6% vs 15%, p<0,01). Após a regressão de Cox, apenas os linfonodos comprometidos influenciaram negativamente o tempo livre de doença. Concluímos que a vulvectomia por três incisões apresenta menos complicações que a incisão única, sem comprometer a eficácia terapêutica, independente do estádio da neoplasia.

Linfedema em Pacientes Submetidas à Mastectomia Radical Modificada

Objetivo: avaliar a taxa de linfedema em pacientes tratadas cirurgicamente para câncer de mama e sua relação com o tipo de cirurgia, idade e peso das pacientes. Métodos: foram estudadas 109 pacientes portadoras de câncer de mama, submetidas à mastectomia radical modificada com conservação do músculo peitoral maior ou de ambos os peitorais. Considerou-se como linfedema quando houve diferença maior que 2,0 cm entre as circunferências dos membros superiores, mensurados acima e abaixo do olécrano. Resultados: observou-se uma taxa total de 14% de linfedema (15 casos). Entre as pacientes em que foram conservados ambos os músculos peitorais, a taxa foi de (9%), ao passo que quando se empregou a conservação apenas do grande peitoral, a taxa foi de 15% (p<0,4). Notou-se uma relação significativa entre a freqüência de linfedema e o peso e a idade das pacientes. O linfedema foi observado em apenas uma das 34 pacientes com menos de 46 anos e nenhuma das 19 pacientes com até 50 kg de peso apresentou linfedema. Conclusão: Na presente série, o linfedema de membro superior esteve associado a pacientes mais idosas e de maior peso.

Preservação dos ovários em cirurgia radical para câncer do colo uterino

OBJETIVO: avaliar a função ovariana em pacientes com câncer do colo uterino, que se submeteram a histerectomia radical com preservação dos ovários. MÉTODOS: foram analisadas retrospectivamente pacientes com câncer do colo uterino, submetidas a histerectomia radical com preservação dos ovários na Clínica Ginecológica do Hospital São Marcos-SPCC, de abril de 1998 a outubro de 2001, com avaliação dos sintomas de privação estrogênica (fogachos, vagina seca) e mensuração dos níveis de FSH pós-operatórios. Os dados foram analisados pelo teste de Pearson. RESULTADOS: os níveis de FSH foram mensurados em 42 pacientes; destas, 33 (78,5%) apresentaram níveis normais de FSH no pós-operatório (menores que 30 mU/mL); os valores variaram entre 1,2 e 132,44 mU/mL (mediana de 21,05 mU/mL). Das nove pacientes com níveis elevados de FSH, cinco (55,6%) haviam sido submetidas a radioterapia pós-operatória (p<0,0001). Não houve associação entre a idade das pacientes e os níveis de FSH (p=0,33). Cistos ovarianos funcionais ocorreram em quatro pacientes (7,7%). Uma paciente apresentou recidiva da lesão na cúpula vaginal e metástase para o couro cabeludo, evoluindo para óbito. CONCLUSÃO: observou-se preservação da função ovariana em 78,5% das pacientes. A transposição ovariana foi inadequada para preservar sua função em pacientes submetidas à radioterapia pós-operatória. Não se observou associação entre idade e níveis de FSH no pós-operatório.

Quimioterapia neoadjuvante seguida de cirurgia radical em paciente grávida com câncer de colo de útero: relato de caso e revisão de literatura

Em pacientes grávidas portadoras de câncer de colo de útero (CCU), as opções terapêuticas dependem da idade gestacional, do estágio clínico e do desejo da paciente. Alguns autores relataram casos de quimioterapia neoadjuvante seguidos de cirurgia radical nessas pacientes. O objetivo deste artigo foi revisitar o assunto, adicionar um novo caso e revisar a literatura. Relatamos o caso de uma mulher de 30 anos, na 24ª semana de gestação, que teve diagnóstico de câncer de colo de útero (carcinoma escamoso grau II), estágio IIB (Federação Internacional de Ginecologia e Obstetrícia - FIGO). Nulípara, a paciente recusou a interrupção da gravidez. Após meticuloso esclarecimento, a paciente aceitou tratamento com quimioterapia neoadjuvante com cisplatina 75 mg/m² e vincristina 1 mg/m², além de posterior avaliação de cirurgia radical e parto cirúrgico concomitantes. Quatros ciclos completos de quimioterapia foram administrados sem atrasos ou efeitos adversos importantes. Poucos dias antes da data programada para a cirurgia, a paciente foi admitida em trabalho de parto na 37ª semana de gestação. Devido à resposta clínica completa do tumor, a equipe obstétrica optou por monitorar o trabalho de parto, e a paciente deu à luz um recém-nascido de 2.450 g, sem intercorrências. A cirurgia radical foi realizada três dias após o parto, e a análise histopatológica revelou carcinoma confinado ao colo sem envolvimento linfonodal. Mãe e filho se encontram em bom estado geral 12 meses após o parto. Quimioterapia baseada em cisplatina durante o segundo ou terceiro trimestre da gravidez parece ser uma opção para as pacientes que não desejam a interrupção da gravidez enquanto se aguarda a maturidade fetal. Entretanto, estudos adicionais são necessários para confirmar o prognóstico e a segurança dos recém-nascidos e das pacientes.

Synecological comparisons sustained by ecophysiological fingerprinting of intrinsic photosynthetic capacity of plants as assessed by measurements of light response curves

In some literature variations in photosynthetic rates are considered to be of little relevance for individual fitness. This depends among other things on how one defines fitness, i.e. if one takes strictly Darwinian fitness as seed production or if one needs to evaluate particular traits and consider plant establishment. It also matters if one takes the Darwinian "organism individual" as the central entity in evolution ("individual fitness") or the "species individual" in a modified "Structure of Evolutionary Theory" sensu Stephen Jay Gould. A phenotypically expressed trait like photosynthetic rate, even if intra- and interspecific differences may be small, can matter in habitat performance and niche acquisition. Light dependence curves (LCs) of photosynthetic rates are now readily measured under field conditions using miniaturized equipment of pulse amplitude modulated fluorometers. In contrast to actual momentary measurements of quantum yield of photosynthesis under actually prevailing ambient conditions, LC measurements reflect the expressed intrinsic capacity of photosynthesis. In this review we explore the power of LC measurements yielding cardinal points such as maximum apparent electron transport rate of photosystem II (ETRmax) and saturating photosynthetically active radiation (PARsat) in making intra- and interspecific comparisons of plant performance and synecological fingerprinting in ecophysiological studies across species, sites, habitats and ecosystems.

Two point deterministic model for acquisition of in vitro pollen grain androgenetic capacity based on wheat studies

This article discusses, from the standpoint of cellular biology, the deterministic and indeterministic androgenesis theories. The role of the vacuole and of various types of stresses on deviation of the microspore from normal development and the point where androgenetic competence is acquired are examined. Based on extensive literature review and data on wheat studies from our laboratory, a model for androgenetic capacity of pollen grain is proposed. A two point deterministic model for in vitro androgenesis is our proposal for acquisition of androgenetic potential of the pollen grain: the first switch point would be early meiosis and the second switch point the uninucleate pollen stage, because the elimination of cytoplasmatic sporophytic determinants takes place at those two strategic moments. Any abnormality in this process allowing the maintenance of sporophytic informational molecules results in the absence of establishment of a gametophytic program, allowing the reactivation of the embryogenic process

Superoxide: a two-edged sword

Superoxide (O2-) is the compound obtained when oxygen is reduced by one electron. For a molecule with an unpaired electron, O2- is surprisingly inert, its chief reaction being a dismutation in which it reacts with itself to form H2O2 and oxygen. The involvement of O2- in biological systems was first revealed by the discovery in 1969 of superoxide dismutase, an enzyme that catalyzes the dismutation of O2-. Since then it has been found that biological systems produce a bewildering variety of reactive oxidants, all but a few arising ultimately from O2-. These oxidants include O2- itself, H2O2 and alkyl peroxides, hydroxyl radical and other reactive oxidizing radicals, oxidized halogens and halamines, singlet oxygen, and peroxynitrite. These various oxidants are able to damage molecules in their environment, and are therefore very dangerous. They are thought to participate in the pathogenesis of a number of common diseases, including among others malignancy, by their ability to mutate the genome, and atherosclerosis, by their capacity for oxidizing lipoproteins. Their properties are put to good use, however, in host defense, where they serve as microbicidal and parasiticidal agents, and in biological signalling, where their liberation in small quantities results in redox-mediated changes in the functions of enzymes and other proteins

Neutralizing capacity of a new monovalent anti-Bothrops atrox antivenom: comparison with two commercial antivenoms

Three horse-derived antivenoms were tested for their ability to neutralize lethal, hemorrhagic, edema-forming, defibrinating and myotoxic activities induced by the venom of Bothrops atrox from Antioquia and Chocó (Colombia). The following antivenoms were used: a) polyvalent (crotaline) antivenom produced by Instituto Clodomiro Picado (Costa Rica), b) monovalent antibothropic antivenom produced by Instituto Nacional de Salud-INS (Bogotá), and c) a new monovalent anti-B. atrox antivenom produced with the venom of B. atrox from Antioquia and Chocó. The three antivenoms neutralized all toxic activities tested albeit with different potencies. The new monovalent anti-B. atrox antivenom showed the highest neutralizing ability against edema-forming and defibrinating effects of B. atrox venom (41 ± 2 and 100 ± 32 µl antivenom/mg venom, respectively), suggesting that it should be useful in the treatment of B. atrox envenomation in Antioquia and Chocó

Differences between remaining ability and loss of capacity in maximum aerobic impairment

In the evaluation of exercise intolerance of patients with respiratory diseases the American Medical Association (AMA) and the American Thoracic Society (ATS) have proposed similar classifications for rating aerobic impairment using maximum oxygen uptake (VO2max) normalized for total body weight (ml min-1 kg-1). However, subjects with the same VO2max weight-corrected values may have considerably different losses of aerobic performance (VO2max expressed as % predicted). We have proposed a new, specific method for rating loss of aerobic capacity (VO2max, % predicted) and we have compared the two classifications in a prospective study involving 75 silicotic claimants. Logistic regression analysis showed that the disagreement between rating systems (higher dysfunction by the AMA/ATS classification) was associated with age >50 years (P<0.005) and overweight (P = 0.04). Interestingly, clinical (dyspnea score) and spirometric (FEV1) normality were only associated with the VO2max, % predicted, normal values (P<0.01); therefore, in older and obese subjects the AMA/ATS classification tended to overestimate the aerobic dysfunction. We conclude that in the evaluation of aerobic impairment in patients with respiratory diseases, the loss of aerobic capacity (VO2max, % predicted) should be used instead of the traditional method (remaining aerobic ability, VO2max, in ml min-1 kg-1).

Nonspecific blockade of vascular free radical signals by methylated arginine analogues

Methylated arginine analogues are often used as probes of the effect of nitric oxide; however, their specificity is unclear and seems to be frequently overestimated. This study analyzed the effects of NG-methyl-L-arginine (L-NMMA) on the endothelium-dependent release of vascular superoxide radicals triggered by increased flow. Plasma ascorbyl radical signals measured by direct electron paramagnetic resonance spectroscopy in 25 rabbits increased by 3.8 ± 0.7 nmol/l vs baseline (28.7 ± 1.4 nmol/l, P<0.001) in response to papaverine-induced flow increases of 121 ± 12%. In contrast, after similar papaverine-induced flow increases simultaneously with L-NMMA infusions, ascorbyl levels were not significantly changed compared to baseline. Similar results were obtained in isolated rabbit aortas perfused ex vivo with the spin trap a-phenyl-N-tert-butylnitrone (N = 22). However, in both preparations, this complete blockade was not reversed by co-infusion of excess L-arginine and was also obtained by N-methyl-D-arginine, thus indicating that it is not related to nitric oxide synthase. L-arginine alone was ineffective, as previously demonstrated for NG-methyl-L-arginine ester (L-NAME). In vitro, neither L-arginine nor its analogues scavenged superoxide radicals. This nonspecific activity of methylated arginine analogues underscores the need for careful controls in order to assess nitric oxide effects, particularly those related to interactions with active oxygen species.

Reference values for lung function tests: III. Carbon monoxide diffusing capacity (transfer factor)

Carbon monoxide diffusing capacity (DLCO) or transfer factor (TLCO) is a particularly useful test of the appropriateness of gas exchange across the lung alveolocapillary membrane. With the purpose of establishing predictive equations for DLCO using a non-smoking sample of the adult Brazilian population, we prospectively evaluated 100 subjects (50 males and 50 females aged 20 to 80 years), randomly selected from more than 8,000 individuals. Gender-specific linear prediction equations were developed by multiple regression analysis with single breath (SB) absolute and volume-corrected (VA) DLCO values as dependent variables. In the prediction equations, age (years) and height (cm) had opposite effects on DLCOSB (ml min-1 mmHg-1), independent of gender (-0.13 (age) + 0.32 (height) - 13.07 in males and -0.075 (age) + 0.18 (height) + 0.20 in females). On the other hand, height had a positive effect on DLCOSB but a negative one on DLCOSB/VA (P<0.01). We found that the predictive values from the most cited studies using predominantly Caucasian samples were significantly different from the actually measured values (P<0.05). Furthermore, oxygen uptake at maximal exercise (VO2max) correlated highly to DLCOSB (R = 0.71, P<0.001); this variable, however, did not maintain an independent role to explain the VO2max variability in the multiple regression analysis (P>0.05). Our results therefore provide an original frame of reference for either DLCOSB or DLCOSB/VA in Brazilian males and females aged 20 to 80 years, obtained from the standardized single-breath technique.

Evaluation of radioinduced damage and repair capacity in blood lymphocytes of breast cancer patients

Genetic damage caused by ionizing radiation and repair capacity of blood lymphocytes from 3 breast cancer patients and 3 healthy donors were investigated using the comet assay. The comets were analyzed by two parameters: comet tail length and visual classification. Blood samples from the donors were irradiated in vitro with a 60Co source at a dose rate of 0.722 Gy/min, with a dose range of 0.2 to 4.0 Gy and analyzed immediately after the procedure and 3 and 24 h later. The basal level of damage and the radioinduced damage were higher in lymphocytes from breast cancer patients than in lymphocytes from healthy donors. The radioinduced damage showed that the two groups had a similar response when analyzed immediately after the irradiations. Therefore, while the healthy donors presented a considerable reduction of damage after 3 h, the patients had a higher residual damage even 24 h after exposure. The repair capacity of blood lymphocytes from the patients was slower than that of lymphocytes from healthy donors. The possible influence of age, disease stage and mutations in the BRCA1 and BRCA2 genes are discussed. Both parameters adopted proved to be sensitive and reproducible: the dose-response curves for DNA migration can be used not only for the analysis of cellular response but also for monitoring therapeutic interventions. Lymphocytes from the breast cancer patients presented an initial radiosensitivity similar to that of healthy subjects but a deficient repair mechanism made them more vulnerable to the genotoxic action of ionizing radiation. However, since lymphocytes from only 3 patients and 3 normal subjects were analyzed in the present paper, additional donors will be necessary for a more accurate evaluation.

Antioxidant status of dog aqueous humor after extracapsular lens extraction

We determined the antioxidant status of the aqueous humor after extracapsular lens extraction in 14 mongrel dogs weighing about 10 kg. The animals were examined by slit lamp biomicroscopy, applanation tonometry and indirect ophthalmoscopy. One eye was submitted to conventional extracapsular lens extraction and the other was used as control. Samples of aqueous humor were obtained by anterior chamber paracentesis before and at days 1, 2, 3, 7 and 15 after surgery. Total antioxidant status was determined as the capacity of aqueous humor to inhibit free radical generation by 2,2-azobis(2-amidopropane) chlorine. Ascorbic acid concentration was measured by HPLC with UV detection. Protein content was determined with the biuret reagent. Statistical analysis was performed by ANOVA followed by the Tukey-Kramer test. Protein concentration increased from 0.61 to 22 mg/ml 24 h after surgery. These levels were maintained and returned to normal at day 7. Total antioxidant capacity was reduced from 50 to about 30 min until day 3 and at day 7 it was equal to control. Ascorbic acid levels were reduced from 252 to about 110 µM and then returned to control values at day 15. Considering the importance of ascorbic acid concentration in aqueous humor for the maintenance of the antioxidant status of the anterior segment of the eye, the decrease of antioxidant defenses suggests that the surgical procedures promote an oxidative stress condition in the eye.