Paradoxical embolization via a patent foramen ovale following acute pulmonary embolism

The foramen ovale is usually obliterated following establishment of the adult circulation but remains patent in 25% of individuals. This potential communication between the venous and arterial circulations can allow thromboembolic material to bypass the lungs and enter the systemic circulation. We report two cases of paradoxical embolization through a patent foramen ovale following acute large pulmonary embolism (PE) and discuss the factors that predispose to paradoxical embolization following PE.

The use of the long gamma nail in proximal femoral fractures

The results of 100 'Long Gamma Nails' (LGN) inserted in 97 patients, for the treatment of complex proximal femoral fractures and pathological lesions, are reported. The mean patient age was 74 (16-98). Seven significant complications occurred; four lag screws cut out, one broken nail, one infected non-union and one peri-prosthetic fracture. Five patients underwent revision either to total hip arthroplasty or exchange nailing. Seventy patients had follow-up of greater than 2 months (mean 10.8 months). Success was defined as stability of the fracture until union or death; this was achieved in 85% of cases. The mortality was 10% at 30 days and 25% at 1 year. The complication rate fell with increasing experience. Complex proximal femoral fractures are difficult to treat with all implants demonstrating high complication rates. The long gamma nail allowed early weight bearing and was effective in 85% of cases. Malpositioning of the implant should be avoided, as this was the leading cause of failure. Surgeon experience is an important factor but training of surgeons does not adversely affect outcome.

Application of Bruchin B to pea pods results in the up-regulation of CYP93C18, a putative isoflavone synthase gene, and an increase in the level of pisatin, an isoflavone phytoalexin

Bruchins, mono and bis (3-hydroxypropanoate) esters of long chain alpha,omega-diols, are a recently discovered class of insect elicitors that stimulate cell division and neoplasm formation when applied to pods of peas and certain other legumes. Differential display analysis resulted in the identification of an mRNA whose level was increased by the application of Bruchin B to pea pods. The corresponding amplification product was cloned and sequenced and a full length cDNA sequence was obtained. This cDNA and the gene from which it was derived were assigned the name CYP93C18 based upon sequence similarities to the cytochrome P450 mono-oxygenase CYP93C subfamily, which contains isoflavone synthase genes from legumes. RNA gel blots and quantitative RT-PCR demonstrated that expression of CYP93C18 increased within 8 h of bruchin treatment to a maximum of 100-200-fold of the level in untreated pods, and then declined. The up-regulation of CYP93C18 was followed by an increase in the level of the isoflavone phytoalexin, pisatin. Pisatin was detectable in the bruchin-treated pods after 16 h and reached a maximum between 32 h and 64 h. This, the first report of induction of phytoalexin biosynthesis by an insect elicitor, suggests that Bruchin B not only stimulates neoplasm formation, but also activates other plant defence responses.

Survival of Apligraf in acute human wounds

Apligraf consists of bovine collagen dermis seeded with allogeneic male fibroblasts and keratinocytes. It is been shown to promote healing, but the length of persistence and pathological features have not been characterized previously in acute wounds. Forty-eight deep dermal wounds were created and Apligraf, a split-skin graft (SSG), or a dressing was applied. Biopsies of wounds were taken for immunohistochemical analysis and polymerase chain reaction was performed to detect the Y chromosome from Apligraf cells in 14 female wounds. Male allogeneic DNA was detected in wounds for the first 4 weeks. All subsequent time points were negative apart from one biopsy at 6 weeks. The wounds took 4-9 weeks to heal, with the Apligraf exhibiting no features of engraftment. This was in contrast to the rapid healing seen in the SSG control group. Histology revealed a more intense cellular infiltrate, but less vascularization below Apligraf compared with controls. Evidence of an epidermal-mesenchymal interaction was observed. This is the first article to elucidate the survival of Apligraf allogeneic cells in acute wounds in immunocompetent human subjects for up to 6 weeks and demonstrates that in the management of acute surgical wounds, Apligraf has a role only as a temporary biological dressing.

Dosimetric verification of IMRT treatment planning using Monte Carlo simulations for prostate cancer

The purpose of this work is to investigate the accuracy of dose calculation of a commercial treatment planning system (Corvus, Normos Corp., Sewickley, PA). In this study, 30 prostate intensity-modulated radiotherapy (IMRT) treatment plans from the commercial treatment planning system were recalculated using the Monte Carlo method. Dose-volume histograms and isodose distributions were compared. Other quantities such as minimum dose to the target (D(min)), the dose received by 98% of the target volume (D98), dose at the isocentre (D(iso)), mean target dose (D(mean)) and the maximum critical structure dose (D(max)) were also evaluated based on our clinical criteria. For coplanar plans, the dose differences between Monte Carlo and the commercial treatment planning system with and without heterogeneity correction were not significant. The differences in the isocentre dose between the commercial treatment planning system and Monte Carlo simulations were less than 3% for all coplanar cases. The differences on D98 were less than 2% on average. The differences in the mean dose to the target between the commercial system and Monte Carlo results were within 3%. The differences in the maximum bladder dose were within 3% for most cases. The maximum dose differences for the rectum were less than 4% for all the cases. For non-coplanar plans, the difference in the minimum target dose between the treatment planning system and Monte Carlo calculations was up to 9% if the heterogeneity correction was not applied in Corvus. This was caused by the excessive attenuation of the non-coplanar beams by the femurs. When the heterogeneity correction was applied in Corvus, the differences were reduced significantly. These results suggest that heterogeneity correction should be used in dose calculation for prostate cancer with non-coplanar beam arrangements.

Quantitative assessment of spasticity in human T-cell lymphotropic virus type I–associated myelopathy/tropical spastic paraparesis

People with human T-cell lymphotropic virus type I-associated myelopathy/tropical spastic paraparesis (HAM/TSP) develop spasticity. The authors examined 34 patients with HAM/TSP in Perú using a device that measures tone in the gastroc-soleus-Achilles tendon unit and provides a quantitative spasticity assessment (QSA). Tone in the 34 patients was more than double that of women with asymptomatic HTLV-I infection. The device may help to track progression in HTLV-I infection.

In-line assessment of pulmonary drug delivery using light obscuration

A candidate optical technology for characterisation of the value and quality of the drug dose delivered to a patient from an inhaler is examined. The theoretical reasoning behind the design of this technology is presented with reference to the optical scattering of the drug cloud. A technical implementation is presented; based upon the light obscuration signature, observed in the delivery path during drug delivery. Dose evaluation studies are reported, performed on different types of drug formulations using regulatory testing procedures and the proposed optical sensing system. Further applications of this technology are discussed in relation to the identification and evaluation of inhaler-drug formulation combinations, which are most suitable for particular patients.

Clinical implementation of intensity-modulated tangential beam irradiation for breast cancer

A Monte Carlo based intensity-modulated radiation therapy (IMRT) treatment planning system has been developed and used for breast treatment. An iterative method was used for optimization to generate IMRT plans and a step-and-shoot technique was used for beam delivery. The patient setup and incident beam directions were the same as those for conventional tangential photon treatment. The weights for the opposed beamlets in the two tangential beams were determined first by the doses at the depths of the maximum dose at both sides to minimize hot spots. The intensity of an individual beamlet pair was then optimized based on the dose at the midplane. Fine tuning was made to achieve optimal target dose uniformity and to reduce the dose to the heart when necessary. The final dose calculations were performed using the Monte Carlo method and the plans were verified by phantom measurements. The dose distributions and dose-volume-histograms of IMRT plans were compared with those of conventional plans that were generated using a commercial treatment planning system and recalculated using an in-house Monte Carlo system for the first 25 patients. The dose comparisons showed that the percentage volume receiving more than 95% of the prescription dose (V95) and the percentage volume receiving more than 100% of the prescription dose (V100) for the clinical target volume (CTV) of IMRT plans were about the same as those of conventional plans. The percentage volume receiving more than 105% of the prescription dose (V105) for the CTV was reduced from 23.1% to 7.9% on average. The percentage volume of the lung receiving more than 20 Gy dose (V20 Gy) during the entire treatment was reduced by about 10%. The percentage volume of the heart receiving more than 30 Gy dose (V30 Gy) is reduced from 3.3% to 0.3%. Further studies revealed that a less than 5 degrees change in couch angle and collimator angle at patient setup had no significant effect on the dose coverage of CTV but had significant effect on the dose to the lung and heart. The study on the effect of beam spoiler showed that it increased the dose at the buildup region by 0- 13% that varies with location. The machine output linearity and stability for small monitor unit delivery of Siemens accelerators used for this study was checked and found to be suitable for breast IMRT. The total effect of variations was calculated to be less than 1% for typical breast treatments. The beam delivery time was increased by about 2 min compared with conventional tangential treatments. The whole treatment including patient setup and beam delivery can be completed in a 15 min slot. The IMRT technique has been proven practical for breast treatment clinically. The results showed that tangential IMRT improved the dose homogeneity in the breast and reduced the dose to the lung and heart.

Stereotactic IMRT for prostate cancer: dosimetric impact of multileaf collimator leaf width in the treatment of prostate cancer with IMRT

The focus of this work is the dosimetric impact of multileaf collimator (MLC) leaf width on the treatment of prostate cancer with intensity-modulated radiation therapy (IMRT). Ten patients with prostate cancer were planned for IMRT delivery using two different MLC leaf widths--4mm and 10mm--representing the Radionics micro-multileaf collimator (mMLC) and Siemens MLC, respectively. Treatment planning was performed on the XKnifeRT2 treatment-planning system (Radionics, Burlington, MA). All beams and optimization parameters were identical for the mMLC and MLC plans. All the plans were normalized to ensure that 95% of the planning target volume (PTV) received 100% of the prescribed dose. The differences in dose distribution between the two different plans were assessed by dose-volume histogram (DVH) analysis of the target and critical organs. We specifically compared the volume of rectum receiving 40 Gy (V40), 50 Gy (V50), 60 Gy (V60), the dose received by 17% and 35% of rectum (D17 and D35), and the maximum dose to 1 cm3 of the rectum for a prescription dose of 74 Gy. For the urinary bladder, the dose received by 25% of bladder (D25), V40, and the maximum dose to 1 cm3 of the organ were recorded. For PTV we compared the maximum dose to the "hottest" 1 cm3 (Dmax1 cm3) and the dose to 99% of the PTV (D99). The dose inhomogeneity in the target, defined as the ratio of the difference in Dmax1 cm3 and D99 to the prescribed dose, was also compared between the two plans. In all cases studied, significant reductions in the volume of rectum receiving doses less than 65 Gy were seen using the mMLC. The average decrease in the volume of the rectum receiving 40 Gy, 50 Gy, and 60 Gy using the mMLC plans was 40.2%, 33.4%, and 17.7%, respectively, with p < 0.0001 for V40 and V50 and p < 0.012 for V60. The mean dose reductions for D17 and D35 for the rectum using the mMLC were 20.4% (p < 0.0001) and 18.3% (p < 0.0002), respectively. There were consistent reductions in all dose indices studied for the bladder. The target dose inhomogeneity was improved in the mMLC plans by an average of 29%. In the high-dose range, there was no significant difference in the dose deposited in the "hottest" 1 cm3 of the rectum between the two plans for all cases (p > 0.78). In conclusion, the use of the mMLC for IMRT of the prostate resulted in significant improvement in the DVH parameters of the prostate and critical organs, which may improve the therapeutic ratio.

Daily target localization for prostate patients based on 3D image correlation

There are several localization techniques that have been used for prostate treatment. Recently, the potential use of a variety of CT-based equipment in the treatment room has been discussed. The goal of our study was to develop an automated procedure for daily treatment table shift calculation based on two CT data sets: simulation CT data and localization CT data. The method suggested in this study is a 3D image cross-correlation of small regions of interest (ROI) within the two data sets. The relative position of the two ROIs with respect to each other is determined by the maximum value of the normalized cross-correlation function, calculated for all possible relative locations of the two ROIs. After the best match is found the shifts are given by the vector connecting the treatment isocentre and the planning isocentre (both determined by the radio opaque fiducial markers on the patient's skin). The results have been compared with shifts calculated through manual fusion. The shift differences, averaged over 17 statistically independent shift calculations, are less then 1 mm in the lateral and longitudinal directions, and about 1 mm in the AP direction. The impact of image noise on the performance of the algorithm has been tested. The results show that the algorithm accurately adjusts for target positional changes even with Gaussian noise levels as high as 20% inserted.

Congenic mice reveal sex-specific genetic regulation of femoral structure and strength

Genetic linkage studies in C3H/HeJ (C3H) and C57BL/6J (B6) mice identified several chromosomal locations or quantitative trait loci (QTL) linked to femoral volumetric bone mineral density (vBMD). From QTL identified on chromosomes (chr) 1, 4, 6, 13, and 18, five congenic mouse strains were developed. In each of these mice, genomic DNA from the QTL region of the donor C3H strain was transferred into the recipient B6 strain. Here we report the effects of donated C3H QTL on femoral structure, cortical vBMD and bending strength. Femoral structure was quantified by the polar moment of inertia (Ip) at the mid-diaphysis, which reflects the bending or torsional rigidity of the femur. Although the C3H progenitor mice have a smaller Ip than B6 progenitor mice, the congenic mice carrying the C3H segment at Chr 4 had significantly increased Ip in both males and females, giving these mice stronger femora. In female mice from the congenic Chr 1 strain, Ip was increased whereas male mice from the Chr 1 strain had smaller femoral cross-sections and significantly reduced Ip. This sex-specific effect on femoral structure was seen to a lesser extent in Chr 18 congenic mice. In addition, cortical vBMD was measured using peripheral quantitative computed tomography. Cortical vBMD was similar among most congenic strains except in Chr 6 congenic mice, where cortical vBMD was significantly less in females, but not in males. We conclude that (1) chromosomal QTL from C3H mice, which are genetically linked to total femoral vBMD, also regulate femoral structure; (2) the QTL on Chr 4 improves femoral structure and strength; (3) QTL on Chr 1 and 18 impart sex-specific effects on femoral structure; and (4) the QTL on Chr 6 imparts a sex-specific effect on cortical vBMD and femoral strength.

Therapeutic benefit of blocking interleukin-6 activity with an anti-interleukin-6 receptor monoclonal antibody in rheumatoid arthritis: a randomized, double-blind, placebo-controlled, dose-escalation trial

OBJECTIVE

To investigate the safety and efficacy of MRA, a recombinant human anti-interleukin-6 (anti-IL-6) receptor monoclonal antibody of the IgG1 subclass that inhibits the function of IL-6, in patients with established rheumatoid arthritis (RA).

METHODS

A randomized, double-blind, placebo-controlled, dose-escalation trial was conducted in 45 patients with active RA, as defined by the American College of Rheumatology (ACR) revised criteria. Patients were sequentially allocated to receive a single intravenous dose of either 0.1, 1, 5, or 10 mg/kg of MRA or placebo. The primary efficacy end point was meeting the ACR 20% response criteria at week 2 after treatment.

RESULTS

Demographic features were similar between treatment groups. At week 2, a significant treatment difference was observed between the 5 mg/kg of MRA and placebo, with 5 patients (55.6%) in the MRA cohort and none in the placebo cohort achieving ACR 20% improvement. There was no statistically significant difference in the ACR 20% response between the other 3 MRA cohorts and placebo at week 2. The mean disease activity score at week 2 in those who received 5 mg/kg and 10 mg/kg of MRA was 4.8 and 4.7 (P < 0.001 and P < 0.001 by analysis of variance), respectively. These mean scores were statistically significantly lower than those in the 0.1- and 1-mg/kg MRA and the placebo cohorts (6.4, 6.2, and 7.0, respectively). The erythrocyte sedimentation rate and C-reactive protein values fell significantly in the 5- and 10-mg/kg MRA cohorts and normalized 2 weeks after treatment. Seventeen patients (5, 4, 6, 2, and 0 patients in the placebo, 0.1-, 1-, 5-, and 10-mg/kg MRA cohorts, respectively) required corticosteroid or disease-modifying antirheumatic drug treatment because of active disease before study end. They were regarded as nonresponders from the time they received these treatments. Diarrhea was the most common adverse event, occurring in 8% of patients. Seven patients (15.6%) reported a severe adverse event (3, 1, 2, and 2 patients in the placebo, 0.1-, 1-, and 10-mg/kg MRA cohorts). There were no serious adverse events that were thought to be related to the study drug.

CONCLUSION

This is the first randomized controlled trial showing that inhibition of IL-6 significantly improved the signs and symptoms of RA and normalized the acute-phase reactants. Further research with multiple dosing is necessary to define the most appropriate therapeutic regimen of MRA in RA.

Characterization of a surface modified dry powder inhalation carrier prepared by "particle smoothing"

Atomic force microscopy (AFM) was used to investigate drug-carrier interactions between beclometasone dipropionate (BDP) and a series of untreated and modified lactose surfaces. This quantitative information was correlated with bulk characterization methods and an in-vitro study. Modified lactose surfaces were prepared using a proprietary process referred to as "particle smoothing" to obtain smooth carrier surfaces with or without the presence of magnesium stearate. The engineering of lactose carrier surfaces using the particle smoothing process resulted in significant differences in surface morphology when compared with the "as supplied" starting material. The energy of separation, between BDP and lactose samples, determined by AFM suggested similar lognormal distributions with a rank decrease in median separation energy (e(0.5)) (26.7, 20.6 and 7.7 microJ for untreated, particle-smoothed and particle-smoothed with magnesium stearate, respectively). A series of in-vitro twin stage impinger studies showed good correlation with the AFM separation energy measurements. The mean fine particle dose increased for the two processed lactose samples, with a significant increase for the lactose processed with magnesium stearate, 102.0+/-16 microg compared with 24.2+/-10.7 microg for the untreated lactose. Thus, the AFM presents as a possible pre-formulation tool for rapid characterization of particle interactions.

The influence of relative humidity on particulate interactions in carrier-based dry powder inhaler formulations

An atomic force microscope (AFM) colloid probe technique has been used to investigate the effect of relative humidity (RH) on the adhesion properties of pharmaceutical powder surfaces. The adhesion between a model substrate, alpha-lactose monohydrate, and model particulate drugs, salbutamol sulphate and budesonide, was investigated between RHs of 15 and 75%. The surface topography of the model alpha-lactose monohydrate was produced by controlling the supersaturation conditions during crystal growth to produce sub-nanometre scale roughness. The adhesion interactions between lactose and drug probes of salbutamol sulphate and budesonide were shown to be significantly increased with each incremental rise in humidity. Capillary forces were significantly more dominant for the adhesion in the budesonide-lactose system up to 60% RH but were more dominant for salbutamol sulphate-lactose above 60% RH. These studies suggested that non-surface-specific capillary forces play a dominant role in the adhesion between drug and carrier, which may significantly reduce the deaggregation and dispersion properties of a dry powder formulation.

Chemical characterisation of sodium starch glycolate particles

The internal and surface chemical compositions of three sodium starch glycolate (SSG) products, Explotab, Primojel and Vivastar P were studied using scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), time of flight secondary ion mass spectrometry (TOF-SIMS) and 23Na nuclear magnetic resonance spectroscopy (NMR). The surfaces of Explotab and Primojel contained very distinct features containing Na and Cl, however, Primojel also contained features which contained Na which may reflect the presence of Na glycolate and/or Na citrates. Vivastar P contained relatively few surface Cl containing features. Analysis of cross-sections of the particles showed that Na appeared to be uniformly distributed throughout the particles of all the products. Additionally, there was a significant concentration of Cl in the periphery of Explotab and Primojel. In the case of Vivastar P, significant levels of Na and Cl were detected in the internal regions of the particles which, together with 23Na NMR, suggests that NaCl is uniformly distributed within Vivastar P. 23Na NMR also suggested that the ratio of organic Na to NaCl was considerably lower in Vivastar P than Primojel and Explotab. Overall, even though all these three products satisfy the pharmacopeial descriptions of SSG, these studies suggest that Primojel and Explotab exhibit different chemical compositions to Vivastar P. Since the three products studied are reported to be prepared from potato starch, the apparent differences in chemical composition probably reflect the different manufacturing processes used, however, batch to batch variations may account for some of the subtle differences.

Decreased bone mineral density in Prader-Willi syndrome: comparison with obese subjects

Bone density, anthropometric data, and markers of bone turnover were collected on 21 subjects diagnosed with Prader-Willi syndrome (PWS) and compared with 9 subjects with obesity of unknown cause. In addition, urinary N-telopeptide levels were obtained in all subjects. N-telopeptides are the peptide fragments of type I collagen, the major bone matrix material. During periods of active bone degradation or high bone turnover, high levels of N-telopeptides are excreted in the urine. However, no significant difference was detected in the urinary N-telopeptide levels when corrected for creatinine excretion (raw or transformed data) between our subjects with obesity or PWS and the observed effect size of the between-group difference was small. Although N-telopeptide levels were higher but not significantly different in the subjects with PWS compared with obese controls, the subjects with PWS had significantly decreased total bone and spine mineral density and total bone mineral content (all P < 0.001). No differences in N-telopeptide levels or bone mineral density were observed between subjects with PWS and chromosome 15q deletion or maternal disomy. Thus, decreased bone mineral density in subjects with PWS may relate to the lack of depositing bone mineral during growth when bones are becoming more dense (e.g., during adolescence), possibly because of decreased production of sex or growth hormones and/or long-standing hypotonia. It may not be caused by loss, or active degradation, of bone matrix measurable by the methods described in this study further supporting the possible need for hormone therapy during adolescence.

Design and validation of an instrument package designed to increase the reliability of ankle range of motion measurements

OBJECTIVE

To validate a novel device termed the equinometer, which is designed to accurately measure ankle dorsiflexion.

DESIGN

Test retest reliability analysis using serial measurements of dorsiflexion endpoint in a group of normal individuals.

SETTING

Motion analysis laboratory.

PARTICIPANTS

Ten healthy individuals.

PRIMARY OUTCOME MEASURE

The mean and standard deviation of the absolute difference in dorsiflexion endpoint for the group.

RESULTS

The mean absolute change in dorsiflexion endpoint for the group was 0.45 degrees with a standard deviation of 0.43 degrees.

CONCLUSIONS

With the use of the device described, the mean change in dorsiflexion endpoint was well within acceptable clinical limits. The reliability of measurements obtained with the equinometer exceeds that which has been published with other techniques and devices.

Cyclic imides as potent and selective alpha-1A adrenergic receptor antagonists

We disclose a new compound class of potent and selective alpha-1A adrenergic receptor antagonists exemplified by the geminally, disubstituted cyclic imide 7. The optimization of lead compounds resulting in the cyclic imide motif is highlighted. The results of in vitro and in vivo studies of selected compounds are presented.

Current injury or disability as a barrier to being more physically active

PURPOSE

To assess the extent to which a current injury or disability is a significant barrier to being more active.

METHODS

Data on current injury or disability as a reported barrier to being more physically active were extracted from an urban-representative population survey. Multivariate logistic regression analyses assessed the association between gender, educational attainment, age, body mass index, and current physical activity levels with injury or disability as a barrier.

RESULTS

Twenty percent of the survey respondents gave current injury or disability as a reason for not being more active. There were no significant differences between male and female subjects. There was a significant trend toward a higher reporting of current injury or disability as a barrier, with increasing age (P < 0.001). High body mass index (P < 0.001) and current physical activity levels (P < 0.05) were significantly related to the injury or disability barrier. The only variables significantly independently associated in multivariate logistic regression analyses were age and body mass index.

CONCLUSIONS

Current injury or disability as a barrier to increased physical activity was independently, and significantly, associated with both age and body mass index, after adjusting for other variables. The promotion of increased physical activity to older and overweight groups should focus on safe activities that do not aggravate previous injuries or disabilities.