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Biomedical subjects

P Felle

Publications and source records attributed to P Felle.

8 recordsLinked to original sources
PubMed2005

Platelets in the paediatric population: the influence of age and the limitations of automation.

Accurate and precise platelet counting is important for the clinical management of children with platelet disorders. Current automated technologies are often unable to discriminate platelets from non-platelet particles particularly in circumstances where platelet anisocytosis is common. This study compares manual methodology and the automated technologies; impedance, optical density and CD61 immunoplatelet method (available on the Cell Dyn 4000) with the reference method of flow cytometric analysis in a paediatric population. A total of 141 samples were analysed and divided into specific age related groups and groups with thrombocytopenia and thrombocytosis. Data analysis showed that the CD61 method compared best with the reference method and this was evident in all the specified groups. The mean platelet count obtained by optical and manual methods were lower, suggesting that these methods are less reliable. The impedance count method was accurate despite its limitations. Strong correlations were observed in the 2-14 year age group but there was greater variation in the <1 month group supporting the theory that there is a greater variation in platelet characteristics in neonates. The CD61 method is the automated method of choice and would be particularly useful in the problem groups (platelet counts <50 x 10(9)/l and neonates <1 month old).

Adolescent↗
PubMed2002

Development of a model for occipital fixation--validation of an analogue bone material.

Several implant systems may be used to fuse the skull to the upper cervical spine (occipitocervical fusion). Current biomechanical evaluation is restricted by the limitations of human cadaveric specimens. This paper describes the design and validation of a synthetic testing model of the occipital bone. Data from thickness measurement and pull-out strength testing of a series of human cadaveric skulls was used in the design of a high-density rigid polyurethane foam model. The synthetic occipital model demonstrated repeatable and consistent morphological and biomechanical properties. The model provides a standardized environment for evaluation of occipital implants.

Biomechanical Phenomena↗
PubMed1998

Patellofemoral contact forces and pressures during intramedullary tibial nailing.

Patellofemoral joint forces and pressures were measured in a cadaver model during intramedullary nailing of the tibia. A significant increase in contact pressures was found at the lateral facet of the patellofemoral articulation using the medial paratendinous approach (P = 0.01) and at the medial facet when using the trans-patellar tendon approach (P = 0.001) to the proximal tibia. Increased contact pressures at the patello-femoral joint may result in chondral injury, which in turn may cause anterior knee pain, a common complication of tibial nailing.

Arthralgia↗
PubMed1998

A new manual power grip.

A manual power grip for holding a cylindrical object using a relaxed index finger is described and analysed. In a group of 21 young adult students it provided greater grip strength than the conventional oblique power grip. It allowed a significant increase in the range of adduction-abduction at the wrist. In recent years it appears to have been empirically used by a number of top class racquet players and is the basis of the modern assault rifle grip. A new design of strain gauge dynamometer, in the shape of a cylinder, which permits the testing of a number of grip types and wrist positions is described. Standard grip testing protocol is used with this device which also allows the concomitant use of a goniometer for the assessment of wrist mobility.

Adolescent↗
PubMed1995

The menisco-femoral ligaments.

The menisco-femoral ligaments were studied in 60 knees from 30 dissecting room cadavers. The anterior horns of the menisci were attached to the intercondylar area of the femur by discrete antero-medial or antero-lateral menisco-femoral ligaments, separate from the anterior cruciate ligament, in 15% of knees for each meniscus, more frequently than previously appreciated; these anterior horn ligaments may exacerbate a meniscal tear. The posterior horn of the lateral meniscus was connected with the intercondylar area of the femur in 100% of knees. In 93% of knees a ligament ran behind the posterior cruciate ligament while in 33% of knees a ligament ran in front of the posterior cruciate ligament. We propose renaming these the pre-cruciate postero-lateral menisco-femoral ligament and post-cruciate postero-lateral menisco-femoral ligament, respectively, to avoid confusion with the ligaments of the anterior horns. The menisco-femoral ligaments may function in controlling movement of the menisci, especially during rotation of the knee. The posterior horn of the medial meniscus has no direct femoral attachment and this may be a factor in the increased risk of injury to this meniscus.

Anterior Cruciate Ligament↗
PubMed1995

Removal of the brain for teaching and examination.

The brain was removed from cadavers using a modified technique involving additionally the removal of most of the squamous occipital bone and laminae of the upper cervical vertebrae. The resulting specimens were superior to the usual ones in that the medulla oblongata, the upper spinal cord, and all the cranial nerves and cerebral arteries were intact. Fears of slow-virus contamination and legislative changes are precluding the use of brains obtained in the necropsy room for neuroanatomy teaching, so it is paramount that complete brains are removed from dissecting room cadavers. The method described herein takes a little longer than the traditional method, but is within the capability of an anatomy technician and yields better specimens for use in teaching and examinations.

Brain↗
PubMed1988

Differences between the histology of normal spleen and that of regenerated ectopically implanted splenic tissue.

The histology of regenerated ectopically implanted spleen (splenotic tissue) from splenectomized rats was compared with that of normal rat spleen. Computer-assisted morphometric analysis revealed significant decreases in both the number and area of splenic nodules in splenotic tissue when compared with normal spleen. It is suggested that the reduction in the amount of white pulp present could explain at least in part the reduced ability of splenotic tissue to deal with infection.

Abdominal Neoplasms↗