RESUMO
The coexistence of plant species in tropical rainforests is related to specific abiotic resources, varying according to the occurrence microhabitat of each species. Light quality is the main abiotic factor influencing germination of small seeds; however, studies often do not discriminate its effect from that of light irradiance. This study compared specific requirements for seed germination of ten small-seeded species, with restricted occurrence in only one of three contrasting microhabitats: forest understorey, edge of clearings and open areas. Laboratory experiments were carried out to test temperature regime (constant or fluctuating), light quality (R:FR) and light irradiance (PAR), which reproduce high and low conditions commonly found in the microhabitats. Seed germination of all species occurred between 20 and 30 °C, only seeds of open area species were able to germinate at 35 °C and no species required alternating temperatures to germinate. Irrespective of species and microhabitat, a decrease in the R:FR reduced the germination percentage; however, there were differences in the capacity to germinate at low R:FR. The values of R:FR50% were higher for open area and edge species (0.441-0.345) than for understorey species (0.181-0.109), with few exceptions. For all species and most of the tests, germination was not influenced by PAR. Light quality is the most important light signal for germination of small seeds; irradiance has little effect. Our results suggest two distinct patterns of germination for small-seeded species: open area and edge species are light-demanding and require high R:FR to germinate, while understorey species are shade-tolerant and germinate at low R:FR. These differences are responsible for distinct microhabitat occurrence and help to explain the coexistence of species in tropical forests.
Assuntos
Germinação , Sementes , Florestas , TemperaturaRESUMO
To mitigate anthropogenic impacts on plant diversity in tropical montane grasslands, one of the most threatened ecosystems in Brazil, it will be essential to develop ex situ conservation strategies to preserve wild species. The lack of basic research on the seed storage behaviour of grassland species may, however, limit their use for reintroduction and restoration projects. We investigated seed storage behaviour at the community level by comparing the effects of cold-low RH (10 °C; 10% RH) and freezing-low RH (20 °C; 10% RH) conditions on seed viability, germination and dormancy of 47 species. Fresh seeds of 43% of the species showed primary dormancy. More than half of the species showed high seed survival responses (viability >60%) under both storage temperatures. Despite a variety of dormancy responses among the different species, the low RH storage conditions tested released dormancy for most species during 12- and 30-month storage times. Multivariate analysis of the best (freezing-low RH, 30 months) storage condition evidenced the formation of five distinct groups, three with species having high conservation potential in seed banks. Although further studies are needed to test dormancy-breaking treatments and improve seed conservation practices, this first approach to assessing seed banking techniques could contribute to demand for locally adapted seeds for ecological restoration projects in tropical montane grasslands.
Assuntos
Germinação , Dormência de Plantas , Brasil , Ecossistema , Pradaria , Sementes , TemperaturaRESUMO
In spite of the possibility of triggering thromboembolic events, many professionals indicate the suspension of antiplatelet agents before dental surgical procedures. The aim of this study was to perform a quantitative assessment of intraoperative bleeding in patients on dual antiplatelet therapy. A case-control study was conducted in patients on dual antiplatelet therapy (APT group) and in patients who did not use these medications (control group). The following examinations were requested: complete blood cell count, blood coagulation tests, and platelet aggregation. The quantity of bleeding was measured intraoperatively by collection of aspirated blood. The mean volume of blood lost during the surgical procedure was 6.10ml in the control group and 16.07ml in the APT group (P=0.002). The mean volume of blood lost per minute was 0.60ml/min in the control group and 1ml/min in the APT group (P=0.001), with local haemostatic methods being sufficient to control the bleeding. There was no postoperative bleeding complication in any case. Patients on dual antiplatelet therapy presented a larger volume of bleeding, but this could be controlled by means of local haemostatic measures. Therefore, there is no need to stop either of the two dual antiplatelet therapy medications before dental extractions.
Assuntos
Aspirina/administração & dosagem , Perda Sanguínea Cirúrgica/estatística & dados numéricos , Hemorragia/epidemiologia , Inibidores da Agregação Plaquetária/administração & dosagem , Ticlopidina/análogos & derivados , Extração Dentária , Doenças Cardiovasculares/tratamento farmacológico , Estudos de Casos e Controles , Clopidogrel , Assistência Odontológica para Doentes Crônicos , Feminino , Hemostasia Cirúrgica/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Ticlopidina/administração & dosagemRESUMO
In spite of the possibility of triggering thromboembolic events, many professionals indicate the suspension of antiplatelet agents before dental surgical procedures. The aim of this study was to perform a quantitative assessment of intraoperative bleeding in patients on dual antiplatelet therapy. A case-control study was conducted in patients on dual antiplatelet therapy (APT group) and in patients who did not use these medications (control group). The following examinations were requested: complete blood cell count, blood coagulation tests, and platelet aggregation. The quantity of bleeding was measured intraoperatively by collection of aspirated blood. The mean volume of blood lost during the surgical procedure was 6.10ml in the control group and 16.07ml in the APT group (P=0.002). The mean volume of blood lost per minute was 0.60ml/min in the control group and 1ml/min in the APT group (P=0.001)...
Assuntos
Complicações Intraoperatórias , Doenças das Artérias Carótidas , Extração Dentária , Hemorragia , Técnicas HemostáticasRESUMO
Literature has shown that, even with the conservative nontraumatic surgical techniques, early repairing surgeries induce changes in the upper dental arch morphologic characteristics in patients with cleft lip and palate. The evaluation of unoperated adult cleft patients enables us to exclude the influence of treatment, emphasizing the morphologic characteristics inherent to the presence of the cleft and its functional counterbalances, that is, the morphologic pattern imposed by cleft. In this study, the maxillary dental casts of 31 unoperated adult complete bilateral cleft lip and palate patients (20 men and 11 women) were compared to a noncleft sample matched for gender. Intercanine, inter-first premolar, inter-second premolar and inter-first molar arch widths measurements as well as arch length were measured from xerox copies taken of the models. The findings indicate the presence of premaxillary prognathism and a progressive increase in the constriction of the dental arches. This constriction of the maxillary segments, even in the absence of surgical intervention, is a result of the absence of an intact palate between the two maxillary processes. Although gender significantly influenced the size of the maxillary arches in the noncleft patients, similar differences were not observed in the cleft group. It seems that the presence of the cleft in itself has the greater influence on the morphologic characteristics of the maxillary arch than gender.
Assuntos
Fenda Labial/patologia , Fissura Palatina/patologia , Arco Dental/patologia , Maxila/patologia , Palato/patologia , Adolescente , Adulto , Estudos de Casos e Controles , Cefalometria , Fenda Labial/complicações , Fissura Palatina/complicações , Arco Dental/anormalidades , Feminino , Humanos , Masculino , Maxila/anormalidades , Pessoa de Meia-Idade , Palato/anormalidades , Prognatismo/etiologia , Valores de Referência , Fatores SexuaisRESUMO
In ten patients a study of skin grafts and of the changes that occurred in the donor area was carried out: the primary retraction of the grafts in relation to their thickness was determined as well as the distension of the donor area of the graft after the excision of the same and comparison of it's thickness with that of the residual skin. The average thickness of the grafts was 318.0 micra, which corresponded to 20% of the donor skin. The primary retraction was 17.6%. The mean thickness of the residual skin at the donor area was 1,287.0 micra or 85.2% of the mean thickness of the reticular derma: the distension of the donor skin area after the removal of the graft corresponded to 2.1% of the original size.
Assuntos
Transplante de Pele/métodos , Retalhos Cirúrgicos/patologia , Adolescente , Adulto , Epiderme/cirurgia , Epiderme/transplante , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The authors review 58 female patients, submitted to abdominoplasty. They utilized a technical approach that permitted to obtain umbilical scars similar to the normal ones.
Assuntos
Músculos Abdominais/cirurgia , Cirurgia Plástica/métodos , Umbigo/cirurgia , Feminino , Humanos , CicatrizaçãoRESUMO
Fournier's syndrome or necrotizing fasceitis of the abdominal-perineal region is a severe acute problem which may lead to a systemic impairment and eventually to death. Skin losses of the scrotum and penis can also be very incapacitating and difficult to repair. At the Hospital das Clínicas da FMUSP the Division of Surgery of Trauma has been able to reduce significantly the mortality rate of this syndrome. Cases with tissue losses were referred to the Division of Plastic Surgery for reconstruction. Several techniques were used in the period 1983-1986 but, in special, the reconstruction of the scrotum has been done using fascio-cutaneous flap the medial aspect of the thigh. Of the twenty nine patients reviewed the majority achieved social and professional rehabilitation.