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Biomedical subjects

S Caeiro

Publications and source records attributed to S Caeiro.

6 recordsLinked to original sources
PubMed2005

Optimal estuarine sediment monitoring network design with simulated annealing.

An objective function based on geostatistical variance reduction, constrained to the reproduction of the probability distribution functions of selected physical and chemical sediment variables, is applied to the selection of the best set of compliance monitoring stations in the Sado river estuary in Portugal. These stations were to be selected from a large set of sampling stations from a prior field campaign. Simulated annealing was chosen to solve the optimisation function model. Both the combinatorial problem structure and the resulting candidate sediment monitoring networks are discussed, and the optimal dimension and spatial distribution are proposed. An optimal network of sixty stations was obtained from an original 153-station sampling campaign.

Environmental Monitoring↗
PubMed2005

Benthic biotope index for classifying habitats in the Sado Estuary: Portugal.

An integration of sediment physical, chemical, biological, and toxicity data is necessary for a meaningful interpretation of the complex sediment conditions in the marine environment. Assessment of benthic community is a vital component for that interpretation, yet their evaluation is complex and requires a large expenditure of time and funds. Thus, there is a need for new tools that are less expensive and more understandable for managers. This paper presents a benthic biotope index to predict from physical and chemical variables the occurrence of macrobenthic habitats. Parameters such as sediment type, organic matter, depth, and hydrodynamic parameters were selected, through a discriminant analysis, to compute the index. Other authors have used multivariate methods to determine the benthic biotopes for Sado Estuary. The index proved to be a valid tool to classify and assess the spatial patterns of benthic habitat and to synthesize stress biotope gradients.

Animals↗
PubMed1999

Cryopreserved arterial homografts: preliminary results in infrageniculate arterial reconstructions.

The aim of this report is to present our preliminary experience using cryopreserved arterial homografts in below-knee revascularization. We carried out a retrospective study at the Public Health Hospital of the Servicio Galego da Saude (SERGAS) from October 1995 to March 1997 in which cryopreserved arterial homografts were used for revascularization of 17 lower limbs in 16 patients. The clinical indications were limb-threatening ischemia in 15 lower extremities (7 with rest pain and 8 with ischemic ulcers or gangrene), and large aneurysms of femoropopliteal arteries in 2. In addition, 75% of the patients had undergone previous surgical procedures for revascularization on the involved extremity. No patient had a suitable greater saphenous vein in the ipsilateral extremity and all patients required a below-knee arterial reconstruction procedure. There was just one runoff vessel in 11 of 17 extremities (65%). A histological exam was performed in four patients who died (1 case) or had homograft-related complications (3 cases). The results of this study indicated that cryopreserved arterial homografts could be a promising alternative when below-knee revascularization is required in patients lacking suitable greater saphenous vein, especially in those with limited life expectancy, but despite early acceptable results, many aspects must be clarified. Close follow-up is mandatory.

Aged↗
PubMed1997

Infected abdominal aortic aneurysm: in situ replacement with cryopreserved arterial homograft.

Infected aortic aneurysms are a rare (1.3% of all abdominal aortic aneurysms) but life-threatening disease. At present controversy continues about the specific diagnosis and the best surgical management. We present one case of infected aortic aneurysm treated with in situ reconstruction with cryopreserved arterial homograft. He was a 50-year-old man with recent history of pneumococcal meningitis who is readmitted because he suffered a stroke and during physical examination a pulsatile abdominal mass was discovered. Blood cultures were done and the result was repeatedly negative. Radiological studies were performed: the abdominal CT scanning showed a non ruptured 5 cm infrarenal aortic aneurysm with irregular wall and in the aortography it appeared eccentric, multilobulated with a clear neck in an otherwise normal size aorta but with some arteriosclerotic lesions. The diagnosis of infected aneurysm was suspected and the patient received antibiotic therapy and was operated on: aneurysm resection with wide debridement of surrounding tissues and in situ aortic replacement with aortobifemoral cryopreserved arterial homograft. Cultures of the aneurysm wall and contents were negative but aneurysm wall biopsy suggested an infected aortic aneurysm. The postoperative course was uneventful and antibiotics were continued for 6 weeks. The patient is doing well 7 months after surgery without signs of recurrent infection and normal appearance of the cryopreserved arterial homograft. We conclude that specific diagnosis of infected aortic aneurysms is essential for correct treatment but may be difficult, in these cases a history of infection supported by radiologic findings and aneurysm wall biopsy are of great value. Cryopreserved arterial homografts constitute a good alternative to prosthetic grafts for in situ reconstructions in the treatment of infected aortic aneurysms, decreasing the risk of re-infection or septic complications.

Aneurysm, Infected↗