Quantitative CT densitometry for predicting intracerebral hemorrhage growth

BACKGROUND AND PURPOSE

Intracerebral hemorrhage growth independently predicts disability and death. We hypothesized that noncontrast quantitative CT densitometry reflects active bleeding and improves predictive models of growth.

MATERIALS AND METHODS

We analyzed 81 of the 96 available baseline CT scans obtained <3 hours post-ICH from the placebo arm of the phase IIb trial of recombinant factor VIIa. Fifteen scans could not be analyzed for technical reasons, but baseline characteristics were not statistically significantly different. Hounsfield unit histograms for each ICH were generated. Analyzed qCTD parameters included the following: mean, SD, coefficient of variation, skewness (distribution asymmetry), and kurtosis ("peakedness" versus "flatness"). These densitometry parameters were examined in statistical models accounting for baseline volume and time-to-scan.

RESULTS

The coefficient of variation of the ICH attenuation was the most significant individual predictor of hematoma growth (adjusted R(2) = 0.107, P = .002), superior to BV (adjusted R(2) = 0.08, P = .006) or TTS (adjusted R(2) = 0.03, P = .05). The most significant combined model incorporated coefficient of variation, BV, and TTS (adjusted R(2) = 0.202, P = .009 for coefficient of variation) compared with BV and TTS alone (adjusted R(2) = 0.115, P < .05). qCTD increased the number of growth predictions within ±1 mL of actual 24-hour growth by up to 47%.

CONCLUSIONS

Heterogeneous ICH attenuation on hyperacute (<3 hours) CT imaging is predictive of subsequent hematoma expansion and may reflect an active bleeding process. Further studies are required to determine whether qCTD can be incorporated into standard imaging protocols for predicting ICH growth.

Using direct payments to fund short breaks for families with a disabled child

BACKGROUND

A clear policy trend exists towards promoting the use of direct payments (DPs), including those for families with disabled children who use short breaks. However, uptake has been slow and use of DPs has been socially patterned. Recent programmes in England have dramatically increased investment in short break provision including breaks funded through DPs. This research examines the characteristics, circumstances and experiences of families who use DPs to fund short breaks with those who use short breaks funded in other ways.

METHOD

The paper draws on surveys totalling 348 parents and carers in families with disabled children using short breaks. We investigate associations between the use of DPs and a range of demographic, socio-economic, well-being, service use and satisfaction indicators. Logistic regression identifies which variables are most strongly associated with use of DPs. We also draw on open-ended survey responses which highlight important aspects of families' experience of using DPs.

RESULTS

Characteristics significantly associated with increased use of DPs include the presence of main carers who are female, more highly educated and from White British backgrounds, younger children, lower levels of area deprivation, greater access to service and social networks and use of more hours of short breaks. Characteristics not found to be significantly associated with use of DPs include various health and well-being indicators, impairment characteristics of children and service satisfaction. A range of benefits of DPs are described along with problems accessing and using them.

CONCLUSIONS

Direct payments can have a number of benefits for families using short breaks, but access to them is currently problematic and socially patterned. If the uptake of DPs is to be increased and made more equitable, more attention must be paid to promoting and supporting their use in ways which meet the needs of individual families.

The GDF5 gene and anterior cruciate ligament rupture

A recent genetic association study has revealed that a variant (rs143383) within the 5'-untranslated region of the growth differentiation factor 5 gene (GDF5) associates with the risk of Achilles tendon pathology. The aim of this study was to determine whether this variant associates with the risk of ACL rupture. A cohort of 126 Caucasians with ACL rupture (ACL group), including 51 subjects who ruptured their ACL through a non-contact mechanism (NON sub-group), and 214 controls (CON group) were genotyped for the rs143383 variant. We report no significant GDF5 rs143383 genotype (P=0.396) or allele (P=0.810) frequency differences between the ACL (TT genotype, n=37, 29%; CT genotype, n=72, 57%; CC genotype, n=17, 14%) and CON (TT genotype, n=73, 34%; CT genotype, n=106, 50%; CC genotype, n=35, 16%) groups. There were also no significant differences between the NON sub-group and the CON group (allele; P=0.710, genotype; P=0.771). Furthermore, in gender specific analysis we found no association between rs143383 and ACL in either males (allele; P=0.988, genotype; P=0.407) or females (allele; P=0.643, genotype; P=0.885), respectively. Nor were there any gender specific associations between the NON sub-group and either genotype or allele. In conclusion, the rs143383 variant was not found to associate with the risk of ACL rupture.

ACE activity and endurance performance during the South African Ironman triathlons

The insertion allele of the angiotensin-converting enzyme (ACE) gene has been associated with endurance performance. Since a large portion of the variance seen in circulatory ACE levels is unaccounted for by the insertion/deletion polymorphism it is likely that the ACE phenotype would serve as a more informative marker in assessing elite endurance performance. The aim of this study was to correlate plasma ACE activity with performance of a homogenous population of South African-born Caucasian male triathletes. Plasma ACE activity was determined in 145 triathletes, representing the fastest and slowest subgroups who completed either the 2000 or 2001 South African Ironman Triathlon. There was a trend for lower mean plasma ACE activity in the fastest (28.85±8.60 mU/ml) when compared to the slowest finisher subgroup (31.65±8.75 mU/ml, P=0.055). There was a significant positive correlation between plasma ACE activity and overall finishing time within the participants who completed the event in under 15 h (r=0.192, P=0.029). There was also a positive correlation with cycle (r=0.195, P=0.034) and run (r=0.184, P=0.040) stages but not the swim stage (r=0.084, P=0.353). In conclusion, this is the first study to report a relationship between plasma ACE activity and endurance performance in humans.

Analysis of a series of patients with varicose vein recurrence

OBJECTIVE

Varicose veins of the lower extremities is a common clinical condition. Although surgical treatment is often successful, the recurrence rate remains high. This retrospective study evaluated the reasons for postoperative recurrence of varicose veins by analysing ultrasonography and venography findings in patients with recurrent disease.

METHODS

A series of consecutive cases of recurrent varicose veins of the lower limbs was reviewed. Data collected included clinical characteristics, symptoms and vascular imaging.

RESULTS

The study included 109 legs with recurrent varicose veins (92 patients): 101/109 legs (92.7%) showed perforating vein insufficiency and 86/109 (78.9%) showed reflux of the superficial femoral vein, of varying degrees of severity. Residual saphenous vein was recorded for 82 legs (75.2%), while 19 (17.4%) had blocked iliac veins due to post-thrombotic syndrome.

CONCLUSIONS

Several factors that may contribute to varicose vein recurrence have been identified. These include failure to ligate perforating veins and initial failure to perform the appropriate surgical intervention. Prevention of varicose vein recurrence after surgical correction requires a more extensive use of preoperative imaging, to tailor surgical intervention to suit individual patients.

Joint perception after hip or knee replacement surgery

INTRODUCTION

Knee and hip arthroplasties are recognized as being effective. However, subjects with a prosthetic joint rarely report returned sensation comparable to their native joint.

HYPOTHESIS

Joint perception by patients following hip joint replacement is better than following knee replacement and in both cases this perception is directly related to the clinical results measured with currently validated scores.

PATIENTS AND METHODS

Patient joint perception in prosthetic reconstruction was evaluated in 347 patients, 46 who underwent unicompartmental knee arthroplasty (UKA), 119 tricompartmental knee arthroplasty (TKA), 93 hip resurfacing (HR), and 89 total hip arthroplasty (THA). The subjects' joint perception, their satisfaction, and the WOMAC clinical score were recorded and compared.

RESULTS

Joint perception was significantly worse for knee arthroplasties (TKA and UKA) compared to hip arthroplasties (THA or HR) (P<0.001). The WOMAC score was also significantly less favorable for knee arthroplasties than for hip arthroplasties (P<0.0001). However, there was no significant difference for the clinical scores between TKA and UKA as well as between HR and THA. Joint perception was strongly correlated with the WOMAC score for all groups (R(2)=0.951).

DISCUSSION

No difference was found after more conservative surgeries such as HR or UKA compared to traditional arthroplasty procedures (THA or TKA). Demonstrating inferior results in comparison to the hip, knee arthroplasties deserve particular attention and can still be improved. The assessment of joint perception used in this study can be considered a valuable clinical tool that is strongly correlated to validated, but more complex to apply, clinical scores.

COL6A1 gene and Ironman triathlon performance

Mutations in the type VI collagen gene ( COL6A1) cause myopathy and muscle weakness. In addition, COL6A1 knockout mice were shown to have impaired running performance and reduced muscle strength. The COL6A1 rs35796750 polymorphism (IVS32-29 T/C) has been associated with complex phenotypes. The aim of this study was therefore to determine if this polymorphism is associated with performance during the 226 km Ironman triathlon. Participants (n=661) were recruited during 4 South African Ironman triathlons. Finishing times for the 3.8 km swim, 180 km bike, 42.2 km run, and overall race were provided by the race organisers. All participants were genotyped for the COL6A1 rs35796750 polymorphism. Participants with the COL6A1 TT genotype were significantly faster during the bike (p=0.014) and overall race (p=0.030). When participants were grouped into fast, middle and slow bike finishing time tertiles, there was a significant linear trend for the TT genotype (Fast: TT=35.7%; Middle: TT=29.0%; Slow: TT=23.8%; p=0.008). No significant genotype frequency differences were observed for the swim or run of the triathlon. In conclusion, the COL6A1 gene is therefore a potential marker for endurance cycling performance. These effects may be mediated through changes to the composition of type VI collagen containing tissues, such as muscle and tendon.

Depth and Distance Perception of Dentists and Dental Students

The quality of work carried out by dentists is dependent, among other things, on experience, training, and manual dexterity. Historical focus on the latter as a predictor of dental performance has failed to recognize that dental competence also requires good perceptual and visual skills, not only for gathering information but also for judging positions, distances, and the size of objects and shapes. Most predictive tests ignore visual and interpretative deficiencies that could make individual acquisition of skills and interpretation of instructions difficult. Ability to estimate depth and distance, the manner in which students learn this ability, whether and how it can be taught, or whether there is an association among ability, stereopsis, and dental performance has not been thoroughly examined; nor has the perception that dental students fully understand verbal and written instruction relating to depth and distance. This study investigated the ability of dentists and dental students to estimate and reproduce small depths and distances and the relationship of this ability to stereopsis, dental experience, and student performance. A total of 163 undergraduate dental students from three year groups and 20 experienced dentists and specialists performed three tasks. A depth-perception task involved estimation of the depth of two sets (2-mm or 4-mm wide) of nine computer milled slots ranging in depth from 0.5 to 4.0 mm. A distance task involved estimation of the width of specially prepared printed square blocks. In a writing task, participants recorded distances across a printed line on separate sheets of paper. All tasks were conducted at set positions in custom-made transportable light boxes. Stereopsis and visual acuity were also measured. Ability to perform perceptual tasks varied enormously, with the level of accuracy dependent on the type of task and dental experience. Many students had considerable difficulty in estimating depth. Inexperienced students performed poorly. Most participants overestimated depth and distance estimation tasks, but underestimated when required to draw distances. Smaller depths and distances were easier to estimate than larger ones. All groups overestimated depth more in 4-mm-wide blocks than in 2-mm-wide blocks. There was no correlation found between depth and distance estimation and stereopsis scores or with the overall grades tested. This study highlights that some dentists and many dental students, particularly early in their course, have great difficulty in accurately gauging depths and distances. It is proposed that that this could impact significantly on a student's ability to interpret verbal and written preclinical instruction and could make the acquisition of manual skills and interpretation of clinical instruction difficult. Routine testing of all undergraduate dental students for perceptual and visual difficulties is recommended, so that those with difficulties can be identified and problems remedied, if possible, early in their course.