Histological and clinical survey of polylactic-polyglycolic acid and dextrane copolymer in maxillary sinus lift: a pilot in vivo study

Of various proposed alternatives to autogenous bone, a synthetic, degradable copolymer of PLA-GLA and dextrane seems to be a promising biomaterial for maxillary sinus lift. Consecutive partially edentulous patients showing severe monolateral posterior maxillary atrophy were treated via sinus lift using PLA-GLA-dextrane copolymer as the sole filler. Delayed implant positioning was performed and cores of regenerated tissues and native bone controls were retrieved and evaluated by light and electron microscopy, histomorphometry, microhardness and qualitative X-ray analysis. Seven sinuses in 7 patients were augmented with PLA-GLA-dextrane copolymer. Six to nine months after the copolymer 'graft', 17 bone cores were retrieved: all histological sections contained newly synthesized, mineralized material and new bone in various stages of development. Histomorphometry revealed average Trabecular Bone Volume (TBV) values ranging from 51% (6 months) to 77% (9 months). Backscattered scanning electron microscopy (BSE) in experimental and control samples confirmed histology findings. Microhardness values suggested newly formed bone at nine months was not as hard as native bone. Ca and P content was similar in 9-month regenerated and native bone. Seventeen implants were inserted in the second stage of surgery: resulting Implant Success (SR) and Cumulative Success (CSR) up to 3 years were 100% following Albrektssons criteria. Sinus lift augmentation using PLA-GLA-dextrane copolymer as the sole filler resulted in uneventful surgeries. New bone formation was evident histologically and its maturation was still in progress after 9 months. Successful, staged implant positioning was achieved in regenerated tissue.     

A tailored lifestyle intervention to reduce the cardiovascular disease risk of individuals with Familial Hypercholesterolemia (FH): design of the PRO-FIT randomised controlled trial

Background  

Because of a high cardiovascular disease (CVD) risk in people with Familial Hypercholesterolemia (FH), early prevention of cardiovascular disease is important for health gain and cost reduction. This project focuses on the development and evaluation of an innovative intervention aiming to reduce CVD risk by promoting a healthy lifestyle among people with FH.     

D-dimer in the diagnostic workup of suspected pulmonary thrombo-embolism at high altitude

Background

Pulmonary thrombo-embolism (PTE) is relatively common in high altitude areas where radiological diagnostic facilities are usually not available. So this study was undertaken to use the results of D-dimer assay to determine the need for imaging studies in patients suspected of having PTE at high altitude.

Methods

A total of 101 patients at an altitude of > 3,000 m suspected of having PTE were evacuated. D-dimer and imaging studies were carried out to confirm the diagnosis.

Results

A total of 101 patients suspected of having PTE underwent D-dimer level estimation and imaging studies for PTE. Sixty-eight of these had negative findings) on D-dimer assay. All these patients with negative findings on D-dimer assay had negative findings on pulmonary imaging studies also. So this test is very sensitive with very high negative predictive value (NPV). Whereas, 17 out of 33 patients positive for D-dimer, had positive findings on imaging studies, indicating a relatively less specific test.

Conclusion

Clinical assessment in combination with D-dimer assay can be used for timely differentiation of PTE from other conditions such as high altitude pulmonary oedema (HAPO) especially at isolated high altitude areas/military posts, so that patients could be evacuated as early as possible by fastest means to save the precious lives and in hospital settings this test identifies patients to whom anticoagulant therapy should not be given or patients who should not be subjected to invasive imaging tests.Key Words: D-dimer test, PTE     

AUTACOID INTERACTIONS IN THE REGULATION OF BLOOD FLOW IN THE HUMAN PLACENTA

1. Interactions between autacoids may play important roles in the regulation of blood flow in the foetal placenta. In order to investigate this aspect of placental haemodynamics, human normal-term placentae were perfused in vitro and the responses of the foetal vessels to various combinations of vasoactive agents were determined. 2. Vasoconstriction responses to 5-hydroxytryptamine (5-HT) were potentiated in the presence of endothelin-1 (ET-1), the thromboxane A₂-mimetic U46619 and a nitric oxide synthase inhibitor, N-nitro-l -arginine (NOLA), but not in the presence of angiotensin II. 3. N-Nitro-l -arginine caused vasoconstriction of the perfused placenta and indomethacin attenuated this effect and blocked the potentiation of the 5-HT response by NOLA. 4. Indomethacin did not affect ET-1-induced pressure increases and infusion of U46619 had no effect on release of ET-Iike immunoreactivity into the foetal placental circulation. 5. The present study provides evidence of interactions between several autacoids in human perfused placentae in vitro. These interactions may play important roles in foetal placental haemodynamics in normal or pathological situations.