The platelet glycoprotein Ia/IIa gene polymorphism C807T/G873A: a novel risk factor for retinal vein occlusion

Retinal vein occlusion (RVO) is associated with hyperhomocysteinaemia and the antiphospholipid syndrome—disorders known to contribute to both arterial and venous thrombosis. In both of these conditions and RVO, platelet activation occurs. Aspirin, not warfarin, is the most effective antithrombotic agent in RVO and, taken together, these observations suggest an important role for platelets in this common ocular thrombotic condition. Platelet glycoprotein Ia/IIa (GpIa/IIa) is an adhesion molecule mediating platelet–collagen interactions and is key to the initiation of thrombosis. Recently, the cellular density of this molecule was shown to be determined by two silent, linked polymorphisms (C807T/G873A) within the GpIa/IIa gene. There is evidence that some of the resulting genotypes are associated with thrombo-embolic disease. This study therefore aimed to establish the prevalence of the GpIa/IIa polymorphisms and the three commonest hereditary thrombophilic disorders (prothrombin gene G20210A (PT) mutation, Factor V Leiden (FVL), and the thermolabile methylene tetrahydrofolate reductase C677T (MTHFR) mutation) in patients with RVO and normal controls. The GpIa/IIa polymorphisms and thrombophilic abnormalities were all identified using the polymerase chain reaction.

Our results show that the frequency of the GpIa/IIa polymorphisms was similar in our normal control population to previously published series. Patients with RVO, however, had only a 10% (4/40) frequency of the lowest risk subtype (CC/GG) compared to 37.5% (15/40) in the control group—P 0.0039. The incidence of the PT, FVL, and MTHFR thrombophilic mutations was not different between the two groups, but interestingly none of the 7/40 RVO cases with a PT, FVL, or MTHFR mutation had the low-risk GpIa/IIa genotype while all but one of the controls did—P<0.05. Thus, 17.5% of RVO patients harboured more than one prothrombotic abnormality. The principal difference between the RVO and control group was the very high incidence of the intermediate-risk GpIa/IIa subtype (CT/GA)—82.5 vs 50%, P<0.05.

These results suggest a major role for GpIa/IIa polymorphisms in the pathogenesis of RVO.

Vascular occlusion training as an alternate method of gaining muscle

Training whilst under the effects of vascular occlusion has become increasingly popular due to the resultant muscle gain associated with this training technique. However, when exercising with the use of a tourniquet type device, it is possible for the pressure being applied to be inconsistent, due the constantly changing cross sectional area of the limb being occluded. This Paper describes the design of a device capable of causing vascular occlusion, but also being able to maintain a stable pressure required to create the blood flow restriction, this being able to be utilized in a sports science environment

Robust object detection under partial occlusion

This thesis focuses on the problem of object detection under partial occlusion in complex scenes through exploring new bottom-up and top-down detection models to cope with object discontinuities and ambiguity caused by partial occlusion and allow for a more robust and adaptive detection of varied objects from different scenes.

Image matching using TI multi-wavelet transform

A multi-resolution image matching technique based on multiwavelets followed by a coarse to fine strategy is presented. The technique addresses the estimation of optimal corresponding points and the corresponding disparity maps in the presence of occlusion, ambiguity and illuminative variations in the two perspective views taken by two different cameras or at different lighting conditions. The problem of occlusion and ambiguity is addressed by a geometric topological refining approach along with the uniqueness constraint whereas the illuminative variation is dealt by using windowed normalized correlation.

Disparity estimation using TI multi-wavelet transform

A multi-resolution image matching technique based on translation invariant discrete multi-wavelet transform followed by a coarse to fine matching strategy is presented. The technique addresses the estimation of optimal corresponding points and the corresponding disparity maps in the presence of occlusion, ambiguity and illuminative variations in the two perspective views taken by two different cameras or at different lighting conditions. The problem of occlusion and ambiguity is addressed explicitly by a geometric optimization approach along with the uniqueness constraint whereas the illuminative variation is dealt with by using windowed normalized correlation on the discrete multi-wavelet coefficients.

A comparative study of computational value in visual cues used in positioning 3D objects

This paper explores the comparative computational values of using a variety of visual cues in 3D environments. The authors reflect upon the possible repercussions of computationally less expensive visual cues on users' ability to efficiently and accurately interact with three-dimensional images. This study compares the effectiveness of expensive soft shadows against less expensive hard shadows and expensive partial-occlusion (obtained by semi-transparent surface) against less expensive occlusion on users' ability to accurately position objects in imminent contact with other objects in a three-dimensional environment.

Tanshinone IIB, a primary active constituent from Salvia miltiorrhza, exhibits neuro-protective activity in experimentally stroked rats

Tanshinone IIB (TSB) is a major active constituent of the root of Salvia miltiorrhiza (Danshen) used in the treatment of acute stroke. Danshen extracts and TSB have shown marked neuron-protective effects in mouse studies but there is a lack of clinical evidence for the neuron-protective effects of Danshen and its active ingredients. This study investigated the neuron-protective effects of TSB in experimentally stroked rats. TSB at 5 and 25 mg/kg by intraperitoneal injection significantly reduced the focal infarct volume, cerebral histological damage and apoptosis in rats subjected to middle cerebral artery occlusion (MCAO) compared to MCAO rats receiving vehicle. This study demonstrated that TSB was effective in reducing stroke-induced brain damage and may represent a novel drug candidate for further development. Further mechanistic studies are needed for the neuron-protective activity of TSB.

Transport of cryptotanshinone, a major active triterpenoid in Salvia miltiorrhiza Bunge widely used in the treatment of stroke and Alzheimers disease, across the blood-brain

Cryptotanshinone (CTS), a major constituent from the roots of Salvia miltiorrhiza (Danshen), is widely used in the treatment of coronary heart disease, stroke and less commonly Alzheimer's disease. Our recent study indicates that CTS is a substrate for Pglycoprotein (PgP/MDR1/ABCB1). This study has investigated the nature of the brain distribution of CTS across the brain-blood barrier (BBB) using several in vitro and in vivo rodent models. A polarized transport of CTS was found in rat primary microvascular endothelial cell (RBMVEC) monolayers, with facilitated efflux from the abluminal side to luminal side. Addition of a PgP (e.g. verapamil and quinidine) or multi-drug resistance protein 1/2 (MRP1/2) inhibitor (e.g. probenecid and MK-571) in both luminal and abluminal sides attenuated the polarized transport. In a bilateral in situ brain perfusion model, the uptake of CTS into the cerebrum increased from 0.52 ± 0.1% at 1 min to 11.13 ± 2.36 ml/100 g tissue at 30 min and was significantly greater than that of sucrose. Co-perfusion of a PgP/MDR1 (e.g. verapamil) or MRP1/2 inhibitor (e.g. probenecid) significantly increased the brain distribution of CTS by 35.1-163.6%. The brain levels of CTS were only about 21% of those in plasma, and were significantly increased when coadministered with verapamil or probenecid in rats. The brain levels of CTS in rats subjected to middle cerebral artery occlusion and rats treated with quinolinic acid (a neurotoxin) were about 2- to 2.5-fold higher than the control rats. Moreover, the brain levels in mdr1a(-/-) and mrp1(-/-) mice were 10.9- and 1.5-fold higher than those in the wild-type mice, respectively. Taken collectively, these findings indicate that PgP and Mrp1 limit the brain penetration of CTS in rodents, suggesting a possible role of PgP and MRP1 in limiting the brain penetration of CTS in patients and causing drug resistance to Danshen therapy and interactions with conventional drugs that are substrates of PgP and MRP1. Further studies are needed to explore the role of other drug transporters in restricting the brain penetration of CTS and the clinical relevance.

Individual discriminative subspace for face recognition under uncontrolled conditions

Most face recognition (FR) algorithms require the face images to satisfy certain restrictions in various aspects like view angle, illumination, occlusion, etc. But what is needed in general is the techniques that can recognize any face images recognizable by human beings. This paper provides one potential solution to this problem. A method named Individual Discriminative Subspace (IDS) is proposed for robust face recognition under uncontrolled conditions. IDS is the subspace where only the images from one particular person converge around the origin while those from others scatter. Each IDS can be used to distinguish one individual from others. There is no restriction on the face images fed into the algorithm, which makes it practical for real-life applications. In the experiments, IDS is tested on two large face databases with extensive variations and performs significantly better than 12 existing FR techniques.

A comparison study of cerebral protection using Ginkgo biloba extract and Losartan on stroked rats

It has been well documented that oxidative stress is involved in stroke. Currently, many neuroprotective strategies have been targeted at molecules that are able to act as an oxidant to intervene with free-radical mediated apoptosis in the ischemic penumbra. In particular, natural products which contain antioxidant properties have undoubtedly efficacious for stroke treatment. In the current study, therapeutic effects of Ginkgo biloba extract (EGb) against cerebral protection in Wistar rats underwent middle cerebral artery occlusion (MCAO) was evaluated. A comparison study was conducted by using Losartan, an antihypertensive drug. Gene expression levels of pro-apoptotic genes (AT2 receptor, Fas, Bax and Bcl-xS) have shown to have significant reduction by EGb- and Losartan-treated groups as compared to vehicle group. Significant reduction of immunoreactivity of protein production of these genes, together with least nuclear green fluorescence observed in TUNEL, EGb, as an antioxidant drug, is concluded to have potent and promising therapeutic effect for stroke treatment.

Nursing administration of medication via enteral tubes in adults : a systematic review

Background Enteral tubes are frequently inserted as part of medical treatment in a wide range of patient situations. Patients with an enteral tube are cared for by nurses in a variety of settings, including general and specialised acute care areas, aged care facilities and at home. Regardless of the setting, nurses have the primary responsibility for administering medication through enteral tubes. Medication administration via an enteral tube is a reasonably common nursing intervention that entails a number of skills, including preparing the medication, verifying the tube position, flushing the tube and assessing for potential complications. If medications are not given effectively through an enteral tube, harmful consequences may result leading to increased morbidity, for example, tube occlusion, diarrhoea and aspiration pneumonia. There are resultant costs for the health-care system related to possible increased length of stay and increased use of equipment. Presently what is considered to be best practice to give medications through enteral tubes is unknown.

Objectives The objective of this systematic review was to determine the best available evidence on which nursing interventions are effective in minimising the complications associated with the administration of medications via enteral tubes in adults. Nursing interventions and considerations related to medication administration included form of medication, verifying tube placement before administration, methods used to give medication, methods used to flush tubes, maintenance of tube patency and specific practices to prevent possible complications related to the administration of enteral medications.

Search strategy The following databases were searched for literature reported in English only: CINAHL, MEDLINE, The Cochrane Library, Current Contents/All Editions, EMBASE, Australasian Medical Index and PsychINFO. There was no date restriction applied. In addition, the reference lists of all included studies were scrutinised for other potentially relevant studies.

Selection criteria Systematic reviews of randomised controlled trials (RCTs) and RCTs that compared the effectiveness of nursing interventions and considerations used in the administration of medications via enteral tubes. Other research methods, such as non-randomised controlled trials, longitudinal studies, cohort and case control studies, were also included. Exclusion criteria included studies investigating drug–nutrient interactions or the bioavailability of specific medications.

Data collection and analysis Initial consideration of potential relevance to the review was carried out by the primary author (NP). Two reviewers independently assessed study eligibility for inclusion. A meta-analysis could not be undertaken, as there were no comparable RCTs identified. All data were presented in a narrative summary.

Results There is very limited evidence regarding the effectiveness of nursing interventions in minimising the complications associated with enteral tube medication administration in adults. The review highlights a lack of high quality research on many important nursing issues relating to enteral medication administration. There is huge scope for further research. Some of the evidence that was identified included that nurses should consider the use of liquid form medications as there may be fewer tube occlusions than with solid forms in nasoenteral tubes and silicone percutaneous endoscopic gastronomy tubes. Nurses may need to consider the sorbitol content of some liquid medications, for example, elixirs, as diarrhoea has been attributed to the sorbitol content of the elixir, not the drug itself. In addition, the use of 30 mL of water for irrigation when administering medications or flushing small-diameter nasoenteral tubes may reduce the number of tube occlusions.

A systematic review of nursing administration of medication via enteral tubes in adults

Aim. This systematic review aimed to determine the best available evidence regarding the effectiveness of nursing interventions in minimising the complications associated with administering medication via enteral tubes in adults.
Background. Giving enteral medication is a fairly common nursing intervention entailing several skills: verifying tube position, preparing medication, flushing the tube and assessing for potential complications. If not carried out effectively harmful consequences may result leading to increased morbidity and even mortality. Until now, what was considered to be best practice in this area was unknown.
Design. Systematic review.
Methods. CINAHL, MEDLINE, The Cochrane Library, Current Contents/All Editions, EMBASE, Australasian Medical Index and PsychINFO databases were searched up to September 2005. Reference lists of included studies were appraised. Two reviewers independently assessed study eligibility for inclusion. There were no comparable randomised-controlled trials; data
were presented in a narrative summary.
Results. Identified evidence included using 30 ml of water for irrigation when giving medication or flushing small-diameter nasoenteral tubes may reduce tube occlusion. Using liquid medication should be considered as there may be less tube occlusions than with solid forms in nasoenteral tubes and silicone percutaneous endoscopic gastrostomy tubes. In addition, nurses may need to consider the sorbitol content of some liquid medications, for example elixirs, as diarrhoea has been attributed to the sorbitol content of the elixir, not the drug itself.
Conclusion. The evidence was limited. There was a lack of high-quality research on many important issues relating to giving enteral medication.
Relevance to clinical practice. Nurses have the primary responsibility for giving medication through enteral tubes and need knowledge of the best available evidence. Some of the nursing considerations and interventions relating to this skill have been researched in the clinical area and have implications for practice. There is a need for further studies to strengthen these findings.

Stereo correspondence estimation using multiwavelets scale-space representation-based multiresolution analysis

A multiresolution technique based on multiwavelets scale-space representation for stereo correspondence estimation is presented. The technique uses the well-known coarse-to-fine strategy, involving the calculation of stereo correspondences at the coarsest resolution level with consequent refinement up to the finest level. Vector coefficients of the multiwavelets transform modulus are used as corresponding features, where modulus maxima defines the shift invariant high-level features (multiscale edges) with phase pointing to the normal of the feature surface. The technique addresses the estimation of optimal corresponding points and the corresponding 2D disparity maps. Illuminative variation that can exist between the perspective views of the same scene is controlled using scale normalization at each decomposition level by dividing the details space coefficients with approximation space. The problems of ambiguity, explicitly, and occlusion, implicitly, are addressed by using a geometric topological refinement procedure. Geometric refinement is based on a symbolic tagging procedure introduced to keep only the most consistent matches in consideration. Symbolic tagging is performed based on probability of occurrence and multiple thresholds. The whole procedure is constrained by the uniqueness and continuity of the corresponding stereo features. The comparative performance of the proposed algorithm with eight famous existing algorithms, presented in the literature, is shown to validate the claims of promising performance of the proposed algorithm.