IL-3-driven T cell-basophil crosstalk enhances antitumor immunity

Cytotoxic T lymphocytes (CTLs) are pivotal in combating cancer, yet their efficacy is often hindered by the immunosuppressive tumor microenvironment, resulting in exhaustion. This study investigates the role of interleukin (IL)-3 in orchestrating anti-tumor immunity through CTL modulation. Intratumoral CTLs undergo a progressive decline in IL-3 production, which is correlated with impaired cytotoxic function. Augmenting IL-3 supplementation, through intraperitoneal administration of recombinant IL-3, IL-3-expressing tumor cells, or IL-3-engineered CD8+ T cells, confers protection against tumor progression, concomitant with increased CTL activity. CTLs are critical in this therapeutic efficacy as IL-3 demonstrates no impact on tumor growth in Rag1 knockout mice or following CD8+ T cell-depletion. Rather than acting directly, CTL-derived IL-3 exerts its influence on basophils, synergistically amplifying anti-tumor immunity within CTLs. Introducing IL-3-activated basophils retards tumor progression, whereas basophil depletion diminishes the effectiveness of IL-3 supplementation. Furthermore, IL-3 prompts basophils to produce IL-4, which subsequently elevates CTL IFN-γ production and viability. Notably, the importance of basophil-derived IL-4 is evident from the absence of benefits of IL-3-supplementatation in IL-4 knockout tumor-bearing mice. Overall, this research unveils IL-3-mediated CTL-basophil crosstalk in regulating anti-tumor immunity, and offers the prospect of harnessing IL-3 sustenance as a promising approach for optimizing and enhancing cancer immunotherapy.

Protocol to assess bioenergetics and mitochondrial fuel usage in murine autoreactive immunocytes using the Seahorse Extracellular Flux Analyzer

Efficient metabolism, or the means by which cells produce energy resources, is critical for proper effector function. Here, we present a protocol for examining the bioenergetics and mitochondrial fuel utilization of primary murine autoreactive immunocytes using cellular metabolism-modulating drugs. We describe steps for plate calibration, isolation of primary immunocytes, and Seahorse assay plate preparation. We then detail procedures for performing the XF Cell Mito Stress Test followed by bioenergetics calculations and statistics. For complete details on the use and execution of this protocol, please refer to Wilson et al.1.

Transcriptome analysis reveals organ-specific effects of 2-deoxyglucose treatment in healthy mice

OBJECTIVE

Glycolytic inhibition via 2-deoxy-D-glucose (2DG) has potential therapeutic benefits for a range of diseases, including cancer, epilepsy, systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA), and COVID-19, but the systemic effects of 2DG on gene function across different tissues are unclear.

METHODS

This study analyzed the transcriptional profiles of nine tissues from C57BL/6J mice treated with 2DG to understand how it modulates pathways systemically. Principal component analysis (PCA), weighted gene co-network analysis (WGCNA), analysis of variance, and pathway analysis were all performed to identify modules altered by 2DG treatment.

RESULTS

PCA revealed that samples clustered predominantly by tissue, suggesting that 2DG affects each tissue uniquely. Unsupervised clustering and WGCNA revealed six distinct tissue-specific modules significantly affected by 2DG, each with unique key pathways and genes. 2DG predominantly affected mitochondrial metabolism in the heart, while in the small intestine, it affected immunological pathways.

CONCLUSIONS

These findings suggest that 2DG has a systemic impact that varies across organs, potentially affecting multiple pathways and functions. The study provides insights into the potential therapeutic benefits of 2DG across different diseases and highlights the importance of understanding its systemic effects for future research and clinical applications.

Dystonin modifiers of junctional epidermolysis bullosa and models of epidermolysis bullosa simplex without dystonia musculorum

The Lamc2jeb junctional epidermolysis bullosa (EB) mouse model has been used to demonstrate that significant genetic modification of EB symptoms is possible, identifying as modifiers Col17a1 and six other quantitative trait loci, several with strong candidate genes including dystonin (Dst/Bpag1). Here, CRISPR/Cas9 was used to alter exon 23 in mouse skin specific isoform Dst-e (Ensembl GRCm38 transcript name Dst-213, transcript ID ENSMUST00000183302.5, protein size 2639AA) and validate a proposed arginine/glutamine difference at amino acid p1226 in B6 versus 129 mice as a modifier of EB. Frame shift deletions (FSD) in mouse Dst-e exon 23 (Dst-eFSD/FSD) were also identified that cause mice carrying wild-type Lamc2 to develop a phenotype similar to human EB simplex without dystonia musculorum. When combined, Dst-eFSD/FSD modifies Lamc2jeb/jeb (FSD+jeb) induced disease in unexpected ways implicating an altered balance between DST-e (BPAG1e) and a rarely reported rodless DST-eS (BPAG1eS) in epithelium as a possible mechanism. Further, FSD+jeb mice with pinnae removed are found to provide a test bed for studying internal epithelium EB disease and treatment without severe skin disease as a limiting factor while also revealing and accelerating significant nasopharynx symptoms present but not previously noted in Lamc2jeb/jeb mice.

Glucose oxidation-dependent survival of activated B cells provides a putative novel therapeutic target for lupus treatment

Aberrant metabolic demand is observed in immune/inflammatory disorders, yet the role in pathogenesis remains unclear. Here, we discover that in lupus, activated B cells, including germinal center B (GCB) cells, have remarkably high glycolytic requirement for survival over T cell populations, as demonstrated by increased metabolic activity in lupus-activated B cells compared to immunization-induced cells. The augmented reliance on glucose oxidation makes GCB cells vulnerable to mitochondrial ROS-induced oxidative stress and apoptosis. Short-term glycolysis inhibition selectively reduces pathogenic activated B in lupus-prone mice, extending their lifespan, without affecting T follicular helper cells. Particularly, BCMA-expressing GCB cells rely heavily on glucose oxidation. Depleting BCMA-expressing activated B cells with APRIL-based CAR-T cells significantly prolongs the lifespan of mice with severe autoimmune disease. These results reveal that glycolysis-dependent activated B and GCB cells, especially those expressing BCMA, are potentially key lupus mediators, and could be targeted to improve disease outcomes.

Transcriptome Analysis Reveals Organ-Specific Effects of 2-Deoxyglucose Treatment in Healthy Mice

OBJECTIVE

Glycolytic inhibition via 2-deoxy-D-glucose (2DG) has potential therapeutic benefits for a range of diseases, including cancer, epilepsy, systemic lupus erythematosus (SLE), and rheumatoid arthritis (RA), and COVID-19, but the systemic effects of 2DG on gene function across different tissues are unclear.

METHODS

This study analyzed the transcriptional profiles of nine tissues from C57BL/6J mice treated with 2DG to understand how it modulates pathways systemically. Principal component analysis (PCA), weighted gene co-network analysis (WGCNA), analysis of variance, and pathway analysis were all performed to identify modules altered by 2DG treatment.

RESULTS

PCA revealed that samples clustered predominantly by tissue, suggesting that 2DG affects each tissue uniquely. Unsupervised clustering and WGCNA revealed six distinct tissue-specific modules significantly affected by 2DG, each with unique key pathways and genes. 2DG predominantly affected mitochondrial metabolism in the heart, while in the small intestine, it affected immunological pathways.

CONCLUSIONS

These findings suggest that 2DG has a systemic impact that varies across organs, potentially affecting multiple pathways and functions. The study provides insights into the potential therapeutic benefits of 2DG across different diseases and highlights the importance of understanding its systemic effects for future research and clinical applications.

Regional shear wave elastography of Achilles tendinopathy in symptomatic versus contralateral Achilles tendons

OBJECTIVES

Ultrasound often corroborates clinical diagnosis of Achilles tendinopathy (AT). Traditional measures assess macromorphological features or use qualitative grading scales, primarily focused within the free tendon. Shear wave imaging can non-invasively quantify tendon elasticity, yet it is unknown if proximal structures are affected by tendon pathology. The purpose of the study was to determine the characteristics of both traditional sonographic measures and regional shear wave speed (SWS) between limbs in patients with AT.

METHODS

Twenty patients with chronic AT were recruited. Traditional sonographic measures of tendon structure were measured. Regional SWS was collected in a resting ankle position along the entire length of the tendon bilaterally. SWS measures were extracted and interpolated across evenly distributed points corresponding to the free tendon (FT), soleus aponeurosis (SA), and gastrocnemius aponeurosis (GA). Comparisons were made between limbs in both traditional sonographic measures and regional SWS.

RESULTS

Symptomatic tendons were thicker (10.2 (1.9) vs. 6.8 (1.8) mm; p < 0.001) and had more hyperemia (p = 0.001) and hypoechogenicity (p = 0.002) than the contralateral tendon. Regional SWS in the FT was lower in the symptomatic limb compared to the contralateral limb (11.53 [10.99, 12.07] vs. 10.97 [10.43, 11.51]; p = 0.03). No differences between limbs were found for the SA (p = 0.13) or GA (p = 0.99).

CONCLUSIONS

Lower SWS was only observed in the FT in AT patients, indicating that alterations in tendon elasticity associated with AT were localized to the FT and did not involve the proximal passive tendon structures.

KEY POINTS

• Baseline characteristics of a pilot sample of 20 subjects suffering from chronic Achilles tendinopathy showed differences in conventional sonographic measures of tendon thickness, qualitatively assessed hypoechogenicity, hyperemia, and quantitative measures of shear wave speed. • Regional shear wave speeds were lower in the free tendon but not in the proximal regions of the soleus or gastrocnemius aponeuroses in Achilles tendinopathy patients. • Using shear wave imaging to estimate tendon stiffness may prove beneficial for clinical validation studies to address important topics such as return to activity and the effectiveness of rehabilitation protocols.

Use of the Independent Medical Spotter in Identifying Head Injuries in Division I Football Players

OBJECTIVE

Sport-related concussion (SRC) is a known risk of contact sports and strategies to minimize risk have been used. We aimed to determine if an independent medical spotter (IMS) identified more SRCs than would otherwise be detected by trained sideline medical staff (SMS).

DESIGN

Prospective review of SRCs during competition in the 2019 season and retrospective review of SRCs in the 2015 to 2018 seasons, which also used an IMS.

SETTING

Division I football games (home and away) of a Big 10 Conference institution.

PARTICIPANTS

All football team members who participated in competition.

INDEPENDENT VARIABLES

Occurrence of SRC during competition and whether the IMS or SMS directly visualized the injury.

MAIN OUTCOME MEASURES

The total number of SRCs that occurred during competition in the 2015 to 2019 football seasons and whom observed the SRC-SMS or IMS-or if a student athlete reported symptoms after competition.

RESULTS

Over the 5-year study period, 24 SRCs occurred during competition. Of those, 19 (79.2%) were observed by SMS, 2 (8.3%) by the IMS, and 3 (12.5%) were reported to SMS after competition ended.

CONCLUSIONS

Most SRCs are accurately identified by SMS, but a small number were apparent only to the IMS who seemed to add sensitivity in detecting a SRC. Instances remain in which SRC recognition and diagnosis were delayed despite trained SMS and IMS.

CLINICAL RELEVANCE

An IMS allows for a small-added player protection benefit using different vantage points to identify potential SRCs during competition.

Providing a Helping Hand: Metabolic Regulation of T Follicular Helper Cells and Their Association With Disease

T follicular helper (Tfh) cells provide support to B cells upon arrival in the germinal center, and thus are critical for the generation of a robust adaptive immune response. Tfh express specific transcription factors and cellular receptors including Bcl6, CXCR5, PD-1, and ICOS, which are critical for homing and overall function. Generally, the induction of an immune response is tightly regulated. However, deviation during this process can result in harmful autoimmunity or the inability to successfully clear pathogens. Recently, it has been shown that Tfh differentiation, activation, and proliferation may be linked with the cellular metabolic state. In this review we will highlight recent discoveries in Tfh differentiation and explore how these cells contribute to functional immunity in disease, including autoimmune-related disorders, cancer, and of particular emphasis, during infection.

Enhancing the efficacy of glycolytic blockade in cancer cells via RAD51 inhibition

Targeting the early steps of the glycolysis pathway in cancers is a well-established therapeutic strategy; however, the doses required to elicit a therapeutic effect on the cancer can be toxic to the patient. Consequently, numerous preclinical and clinical studies have combined glycolytic blockade with other therapies. However, most of these other therapies do not specifically target cancer cells, and thus adversely affect normal tissue. Here we first show that a diverse number of cancer models – spontaneous, patient-derived xenografted tumor samples, and xenografted human cancer cells – can be efficiently targeted by 2-deoxy-D-Glucose (2DG), a well-known glycolytic inhibitor. Next, we tested the cancer-cell specificity of a therapeutic compound using the MEC1 cell line, a chronic lymphocytic leukemia (CLL) cell line that expresses activation induced cytidine deaminase (AID). We show that MEC1 cells, are susceptible to 4,4ʹ-Diisothiocyano-2,2ʹ-stilbenedisulfonic acid (DIDS), a specific RAD51 inhibitor. We then combine 2DG and DIDS, each at a lower dose and demonstrate that this combination is more efficacious than fludarabine, the current standard- of- care treatment for CLL. This suggests that the therapeutic blockade of glycolysis together with the therapeutic inhibition of RAD51-dependent homologous recombination can be a potentially beneficial combination for targeting AID positive cancer cells with minimal adverse effects on normal tissue.

Implications: Combination therapy targeting glycolysis and specific RAD51 function shows increased efficacy as compared to standard of care treatments in leukemias.

Impact of pH on the viability and morphology of Blastocystis isolates

Blastocystis sp. is ubiquitous in avian, mammalian and human hosts and propagates in either neutral or slightly alkaline conditions within the host's gastro-intestinal tract. Of the few previous studies on this enteric protozoan parasite in feline and canine hosts, prevalence values have been shown to range between 0 to 70.8%. In view of the close association between humans, and canine and feline hosts as companion animals, faecal samples of 180 Felis catus and 82 Canis lupus, collected from Penang and Kuala Lumpur, Malaysia, were initially screened by in vitro cultivation followed by molecular characterization. No positive isolates were identified in culture but in 12 feline samples DNA barcoding detected a zoonotic subtype Blastocystis ST1 for the first time. Consequently, avian and human isolates, which had previously been successfully cultured, were used to investigate the impact of pH on the viability and morphology of Blastocystis sp. The use of Trypan blue showed that the number of viable cells increased when exposed to pH 4 and a significant increase in viability occurred in pH values of 5 to 7. Development of Blastocystis cells in both isolates was suppressed in media less than pH 5 followed by the disappearance of viable cells from avian isolates in more acidic media below pH 4. Morphologically at pH 4 cells from avian isolates were less rounded, and with wrinkled / shrunken surfaces, than the more normal rounded cells from human isolates. On the other hand, at values below pH 3, no viable cells in human isolates were visible. The present findings therefore confirm that gastro-intestinal pH is an important determinant of Blastocystis viability and consequently influences the epidemiology of infection within avian, mammalian and human hosts.

Bicomponent ultrashort echo time T2* analysis for assessment of patients with patellar tendinopathy

PURPOSE

To compare bicomponent ultrashort echo time (UTE) T2* parameters of patellar tendon between healthy volunteers and patients with patellar tendinopathy.

MATERIALS AND METHODS

This study was performed with Institutional Review Board approval and with all subjects signing informed consent. A UTE- T2* mapping sequence was performed at 3.0T on the knees of 10 healthy volunteers and in 11 patients with patellar tendinopathy. The UTE- T2* relaxation times of the fast relaxing macromolecular bound water component ( T2*F) and the slow relaxing bulk water component ( T2*S) and the fraction of the fast relaxing macromolecular bound water component (F_F ) of patellar tendon were measured in all subjects. Wilcoxon rank-sum tests were used to compare UTE- T2* parameters between healthy volunteers and patients with patellar tendinopathy.

RESULTS

Mean T2*F, T2*S, and F_F of the patellar tendon was 1.5 msec, 23.1 msec, and 79.5%, respectively, for healthy volunteers and 1.9 msec, 22.3 msec, and 75.5%, respectively, for patients with patellar tendinopathy. There were statistically significant differences between groups of subjects for T2*F (P = 0.01) and F_F (P = 0.007) but not T2*S (P = 0.10) of the patellar tendon.

CONCLUSION

Patients with patellar tendinopathy had significantly higher T2*F and significantly lower F_F of patellar tendon than healthy volunteers, which suggests that bicomponent UTE- T2* parameters can detect changes in the composition and microstructure of degenerative tendon.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2017;46:1441-1447.

Comparing accelerometer, pedometer and a questionnaire for measuring physical activity in bronchiectasis: a validity and feasibility study?

Background

There are challenges for researchers and clinicians to select the most appropriate physical activity tool, and a balance between precision and feasibility is needed. Currently it is unclear which physical activity tool should be used to assess physical activity in Bronchiectasis. The aim of this research is to compare assessment methods (pedometer and IPAQ) to our criterion method (ActiGraph) for the measurement of physical activity dimensions in Bronchiectasis (BE), and to assess their feasibility and acceptability.

Methods

Patients in this analysis were enrolled in a cross-sectional study. The ActiGraph and pedometer were worn for seven consecutive days and the IPAQ was completed for the same period. Statistical analyses were performed using SPSS 20 (IBM). Descriptive statistics were used; the percentage agreement between ActiGraph and the other measures were calculated using limits of agreement. Feedback about the feasibility of the activity monitors and the IPAQ was obtained.

Results

There were 55 (22 male) data sets available. For step count there was no significant difference between the ActiGraph and Pedometer, however, total physical activity time (mins) as recorded by the ActiGraph was significantly higher than the pedometer (mean ± SD, 232 (75) vs. 63 (32)). Levels of agreement between the two devices was very good for step count (97% agreement); and variation in the levels of agreement were within accepted limits of ±2 standard deviations from the mean value.

IPAQ reported more bouted- moderate - vigorous physical activity (MVPA) [mean, SD; 167(170) vs 6(9) mins/day], and significantly less sedentary time than ActiGraph [mean, SD; 362(115) vs 634(76) vmins/day]. There were low levels of agreement between the two tools (57% sedentary behaviour; 0% MVPA₁₀₊), with IPAQ under-reporting sedentary behaviour and over-reporting MVPA₁₀₊ compared to ActiGraph. The monitors were found to be feasible and acceptable by participants and researchers; while the IPAQ was accepta ble to use, most patients required assistance to complete it.

Conclusions

Accurate measurement of physical activity is feasible in BE and will be valuable for future trials of therapeutic interventions. ActiGraph or pedometer could be used to measure simple daily step counts, but ActiGraph was superior as it measured intensity of physical activity and was a more precise measure of time spent walking. The IPAQ does not appear to represent an accurate measure of physical activity in this population.

Trial registration

Clinical Trials Registration Number NCT01569009: Physical Activity in Bronchiectasis.

Intratendinous injections of platelet-rich plasma: feasibility and effect on tendon morphology and mechanics

BACKGROUND

Intratendinous injections may have important effects on the properties of collagen microarchitecture, morphology, and subsequent mechanical properties of the injected tendon. The purpose of this study was to examine the effects of intratendinous PRP injections; the injectant retention within tendons, the distribution of intratendinous injectant, and whether intratendinous injection or needle fenestration alters tendon morphology or mechanics.

METHODS

DESIGN

Controlled Laboratory Study.

INTERVENTIONS

In the first part of the study, 18 lamb extensor tendons were selected to receive methylene blue-containing PRP injection (PRP/MB), methylene blue only injection (MB), or needle fenestration. The volume of retained injectant was measured and injectant distribution and tendon morphology were examined microscopically. In the second portion of the study, 18 porcine flexor tendons were divided into control, needle fenestration, or saline injection groups. Young's Modulus was then determined for each tendon under 0-4% strain.

MAIN OUTCOME MEASURES

1) Injectant volume retained; 2) Injectant distribution; 3) Post-injection/fenestration alterations in morphology, biomechanics.

RESULTS

Intratendinous injectant is retained within the tendon. The difference between PRP and PRP/MB groups was not significant (p = 0.78). Intratendinous spread of the injectant solution within the tendon occurs primarily in the proximodistal direction, with very little cross-sectional penetration. Intratendinous injections resulted in microscopic morphology disruption (e.g., separation and disorganization of both the collagen bundles and cellular distribution). There were significant differences in Young's Modulus between control (Ectrl = 2415.48) and injected tendons (Einj = 1753.45) at 4% strain (p = 0.01). There were no differences in Young's Modulus between fenestrated and control tendons.

CONCLUSIONS

Intratendinous PRP injections are retained within the tendon, and primarily distributes longitudinally with minimal cross-sectional spread. Intratendinous injections may alter tendon morphology and mechanics.

Complete mitochondrial genome of the soft-shell clam Mya arenaria

We have sequenced and characterized the complete mitochondrial genome of the soft-shell clam, Mya arenaria, an important organism for environmental toxicology and aquaculture. Mya arenaria is located in the taxonomic order Myoida, which lacks any member with a completely annotated mitogenome. The M. arenaria mitochondrial genome is 17 947 bp in length. Like most marine bivalves, the circular mitogenome codes entirely on the heavy strand, with no introns. As with other bivalves, the gene order of the mitochondrion is highly rearranged. The mitogenome contains 12 protein-coding genes but ATP8 is missing, consistent with about half of all bivalve genera. Twenty-three tRNAs were identified. Phylogenetic analysis shows that M. arenaria is related most closely with the bivalves Sinonovacula constricta, and Moerella iridescens, of the infraclass Euheterodonta (unassigned). This, along with the close grouping of the phylogenetic trees, confirms a close tie between Myoida and Euheterodonta (unassigned).

Articular Cartilage of the Human Knee Joint: In Vivo Multicomponent T2 Analysis at 3.0 T

PURPOSE

To compare multicomponent T2 parameters of the articular cartilage of the knee joint measured by using multicomponent driven equilibrium single-shot observation of T1 and T2 (mcDESPOT) in asymptomatic volunteers and patients with osteoarthritis.

MATERIALS AND METHODS

This prospective study was performed with institutional review board approval and with written informed consent from all subjects. The mcDESPOT sequence was performed in the knee joint of 13 asymptomatic volunteers and 14 patients with osteoarthritis of the knee. Single-component T2 (T2(Single)), T2 of the fast-relaxing water component (T2F) and of the slow-relaxing water component (T2S), and the fraction of the fast-relaxing water component (F(F)) of cartilage were measured. Wilcoxon rank-sum tests and multivariate linear regression models were used to compare mcDESPOT parameters between volunteers and patients with osteoarthritis. Receiver operating characteristic analysis was used to assess diagnostic performance with mcDESPOT parameters for distinguishing morphologically normal cartilage from morphologically degenerative cartilage identified at magnetic resonance imaging in eight cartilage subsections of the knee joint.

RESULTS

Higher cartilage T2(Single) (P < .001), lower cartilage F(F) (P < .001), and similar cartilage T2F (P = .079) and T2S (P = .124) values were seen in patients with osteoarthritis compared with those in asymptomatic volunteers. Differences in T2(Single) and F(F) remained significant (P < .05) after consideration of age differences between groups of subjects. Diagnostic performance was higher with F(F) than with T2(Single) for distinguishing between normal and degenerative cartilage (P < .05), with greater areas under the curve at receiver operating characteristic analysis.

CONCLUSION

Patients with osteoarthritis of the knee had significantly higher cartilage T2(Single) and significantly lower cartilage F(F) than did asymptomatic volunteers, and receiver operating characteristic analysis results suggested that F(F) may allow greater diagnostic performance than that with T2(Single) for distinguishing between normal and degenerative cartilage.

Rapid in vivo multicomponent T2 mapping of human knee menisci

PURPOSE

To compare multicomponent T2 parameters of menisci measured using Multicomponent Driven Equilibrium Single Pulse Observation of T1 and T2 (mcDESPOT) in asymptomatic volunteers and osteoarthritis (OA) patients with intact and torn menisci.

MATERIALS AND METHODS

The prospective study was performed with Institutional Review Board approval and with all subjects signing written informed consent. mcDESPOT was performed on the knee joint of 12 asymptomatic volunteers and 14 patients with knee OA. Single-component T2 relaxation time (T2Single ), T2 relaxation time of the fast relaxing water component (T2F ), and the slow relaxing water component (T2S ), and fraction of the fast relaxing water component (FF ) of the medial and lateral menisci were measured. Multivariate linear regression models were used to compare mcDESPOT parameters between normal menisci in asymptomatic volunteers, intact menisci in OA patients, and torn menisci in OA patients with adjustment for differences in age between subjects.

RESULTS

The mean mcDESPOT parameters for normal menisci in asymptomatic volunteers, intact menisci in OA patients, and torn menisci in OA patients were respectively 16.1 msec, 18.8 msec, and 22.7 msec for T2Single ; 9.0 msec, 10.0 msec, and 11.1 msec for T2F ; 24.4 msec, 27.7 msec, and 31.4 msec for T2S ; and 34%, 32%, 27% for FF . There were significant differences (P < 0.05) in T2Single , T2F , T2S , and FF between the three groups of menisci.

CONCLUSION

The menisci of OA patients had significantly higher T2Single , T2F , and T2S and significantly lower FF than normal menisci in asymptomatic volunteers with greater changes in multicomponent T2 parameters noted in torn than intact menisci in OA patients.

Application of ion exchange and extraction chromatography to the separation of actinium from proton-irradiated thorium metal for analytical purposes

Actinium-225 (t1/2=9.92d) is an α-emitting radionuclide with nuclear properties well-suited for use in targeted alpha therapy (TAT), a powerful treatment method for malignant tumors. Actinium-225 can also be utilized as a generator for (213)Bi (t1/2 45.6 min), which is another valuable candidate for TAT. Actinium-225 can be produced via proton irradiation of thorium metal; however, long-lived (227)Ac (t1/2=21.8a, 99% β(-), 1% α) is co-produced during this process and will impact the quality of the final product. Thus, accurate assays are needed to determine the (225)Ac/(227)Ac ratio, which is dependent on beam energy, irradiation time and target design. Accurate actinium assays, in turn, require efficient separation of actinium isotopes from both the Th matrix and highly radioactive activation by-products, especially radiolanthanides formed from proton-induced fission. In this study, we introduce a novel, selective chromatographic technique for the recovery and purification of actinium isotopes from irradiated Th matrices. A two-step sequence of cation exchange and extraction chromatography was implemented. Radiolanthanides were quantitatively removed from Ac, and no non-Ac radionuclidic impurities were detected in the final Ac fraction. An (225)Ac spike added prior to separation was recovered at ≥ 98%, and Ac decontamination from Th was found to be ≥ 10(6). The purified actinium fraction allowed for highly accurate (227)Ac determination at analytical scales, i.e., at (227)Ac activities of 1-100 kBq (27 nCi to 2.7 μCi).

Cross-relaxation imaging of human patellar cartilage in vivo at 3.0T

OBJECTIVE

To compare quantitative magnetization transfer (qMT) parameters of patellar cartilage measured using cross-relaxation imaging (CRI) in asymptomatic volunteers and patients with osteoarthritis.

DESIGN

The study was performed with Institutional Review Board approval and with all subjects signing informed consent. CRI of the knee joint was performed at 3.0T on 20 asymptomatic volunteers and 11 patients with osteoarthritis. The fraction of macromolecular bound protons (f), the exchange rate constant between macromolecular bound protons and free water protons (k), and the T2 relaxation time of macromolecular bound protons (T2(B)) of patellar cartilage were measured. Mann-Whitney-Wilcoxon rank-sum tests were used to compare qMT parameters between asymptomatic volunteers and patients with osteoarthritis.

RESULTS

Average f, k, and T2(B) of patellar cartilage was 12.46%, 7.22 s(-1), and 6.49 μs respectively for asymptomatic volunteers and 12.80%, 6.13 s(-1), and 6.80 μs respectively for patients with osteoarthritis. There were statistically significant differences between groups of subjects for k (P < 0.01) and T2(B) (P < 0.0001) but not f (P = 0.38) of patellar cartilage.

CONCLUSION

Patients with osteoarthritis had significantly lower k and significantly higher T2(B) of patellar cartilage than asymptomatic volunteers which suggests that qMT parameters can detect changes in the macromolecular matrix of degenerative cartilage.

Platelet-rich plasma for the treatment of chronic plantar fasciopathy in adults: a case series

Plantar fasciopathy (PF) is a common source of pain and disability that is often refractory to conservative management. There are no uniformly effective standard-of-care treatments for chronic recalcitrant PF. Corticosteroid injection is considered a viable treatment option when traditional therapies fail, but is limited by suboptimal long-term efficacy and potential adverse effects. Platelet-rich plasma (PRP) is an emerging injection-based treatment for various chronic degenerative soft-tissue diseases. It is postulated to promote native tissue regeneration; however, consistent scientific evidence remains lacking. A prospective case series, including 24 consecutive PF cases, was conducted to report patient-rated pain and disability following PRP injection. Foot and Ankle Ability Measure (FAAM) scores were the primary clinical outcome measure. Foot-Single Assessment Numeric Evaluation (Foot-SANE) scores, Short Form-12 Health Survey version 2 (SF-12v2) questionnaires, and PRP treatment satisfaction surveys were secondary outcome measures. Statistical analysis compared baseline and 32 weeks post-injection time points. Patients receiving PRP injection reported clinically and statistically significant improvement in all outcome measures during this interval. There were no serious adverse events associated with treatment. PRP is considered a safe therapeutic option with the ability to decrease heel pain in patients with chronic PF refractory to appropriate conservative management.

Effectiveness of Platelet-rich Plasma Injection for Rotator Cuff Tendinopathy: A Prospective Open-label Study

Objective:

Assess platelet rich plasma (PRP) injection for rotator cuff tendinopathy (RCT).

Design:

Prospective open label study with 1-year follow-up.

Methods:

Participants recruited from an outpatient sports medicine clinic had clinically and magnetic resonance image (MRI)—demonstrated RCT refractory to physical therapy and corticosteroid injection. They received one ultrasound-guided injection of 3.0 mL of 1% xylocaine followed by 3.5 mL of PRP at the lesion and surrounding tendon. Primary outcome: 0–10 visual analog scale (VAS; baseline, 8, 12, and 52 weeks). Secondary outcomes: functional shoulder tests assessing rotator cuff strength and endurance (at baseline and 8 and 12 weeks), MRI severity (1–5 points [at baseline and 4 and 8 weeks]), and patient satisfaction (52 weeks).

Results:

Eighteen participants with 19 assessed shoulders reported VAS pain score improvement from 7.5 ± 0.3 points to 0.5 ± 0.3 points by week 12 and 0.4 ± 0.2 (P = .0001) points at week 52. Functional outcomes significantly improved; the largest effect was seen in the external rotation test: 33.5 ± 5.7 seconds to 62.6 ± 7.2 seconds at week 12 (P = .0001). MRI appearance improved by 1 to 3 points in 16 of 18 assessed shoulders. Seventeen participants were “completely satisfied” (12) or “satisfied” (5). One participant was “unsatisfied.”

Conclusions:

A single ultrasound-guided, intralesional injection of PRP resulted in safe, significant, sustained improvement of pain, function, and MRI outcomes in participants with refractory RCT. Randomized multidisciplinary effectiveness trials that add ultrasound and validated clinical outcome measures are needed to further assess PRP for RCT.

Evaluation of the patient with hip pain

Hip pain is a common and disabling condition that affects patients of all ages. The differential diagnosis of hip pain is broad, presenting a diagnostic challenge. Patients often express that their hip pain is localized to one of three anatomic regions: the anterior hip and groin, the posterior hip and buttock, or the lateral hip. Anterior hip and groin pain is commonly associated with intra-articular pathology, such as osteoarthritis and hip labral tears. Posterior hip pain is associated with piriformis syndrome, sacroiliac joint dysfunction, lumbar radiculopathy, and less commonly ischiofemoral impingement and vascular claudication. Lateral hip pain occurs with greater trochanteric pain syndrome. Clinical examination tests, although helpful, are not highly sensitive or specific for most diagnoses; however, a rational approach to the hip examination can be used. Radiography should be performed if acute fracture, dislocations, or stress fractures are suspected. Initial plain radiography of the hip should include an anteroposterior view of the pelvis and frog-leg lateral view of the symptomatic hip. Magnetic resonance imaging should be performed if the history and plain radiograph results are not diagnostic. Magnetic resonance imaging is valuable for the detection of occult traumatic fractures, stress fractures, and osteonecrosis of the femoral head. Magnetic resonance arthrography is the diagnostic test of choice for labral tears.

Visualizing tendon elasticity in an ex vivo partial tear model

Supersonic shear imaging (SSI) is evaluated as a means of visualizing changes in regional tendon elasticity caused by partial tears in a porcine model. Thirty digital flexor tendons were cut to 25% (n = 10), 50% (n = 10) and 75% (n = 10) of the tendon thickness along the deep surface. Tendon elasticity was mapped left of, centered on and right of the tear site before and after tearing from 0% to 2% strain. Shear wave speed increased at 1% (p < 0.05) and 2% (p < 0.001) strain for all regions. Deep surface shear wave speed decreased in the 25%, 50% and 75% tears (p < 0.05 and p < 0.001). Computational tendon tear models were also created to investigate regional changes in strain resulting from a tear. In the computational models, strain on the deep surface decreased progressively with increasing tear size. Visualization of tendon shear wave speed was achieved in normal and partially torn tendons, indicating the potential of SSI to add tendon shear wave speed to traditional morphologic assessment of partial tears, which may improve assessment of tendon health.

Integration of DNA barcoding into an ongoing inventory of complex tropical biodiversity

Inventory of the caterpillars, their food plants and parasitoids began in 1978 for today's Area de Conservacion Guanacaste (ACG), in northwestern Costa Rica. This complex mosaic of 120 000 ha of conserved and regenerating dry, cloud and rain forest over 0-2000 m elevation contains at least 10 000 species of non-leaf-mining caterpillars used by more than 5000 species of parasitoids. Several hundred thousand specimens of ACG-reared adult Lepidoptera and parasitoids have been intensively and extensively studied morphologically by many taxonomists, including most of the co-authors. DNA barcoding - the use of a standardized short mitochondrial DNA sequence to identify specimens and flush out undisclosed species - was added to the taxonomic identification process in 2003. Barcoding has been found to be extremely accurate during the identification of about 100 000 specimens of about 3500 morphologically defined species of adult moths, butterflies, tachinid flies, and parasitoid wasps. Less than 1% of the species have such similar barcodes that a molecularly based taxonomic identification is impossible. No specimen with a full barcode was misidentified when its barcode was compared with the barcode library. Also as expected from early trials, barcoding a series from all morphologically defined species, and correlating the morphological, ecological and barcode traits, has revealed many hundreds of overlooked presumptive species. Many but not all of these cryptic species can now be distinguished by subtle morphological and/or ecological traits previously ascribed to 'variation' or thought to be insignificant for species-level recognition. Adding DNA barcoding to the inventory has substantially improved the quality and depth of the inventory, and greatly multiplied the number of situations requiring further taxonomic work for resolution.

An update on the diagnosis and management of concussion

Concussion is a common medical problem with significant morbidity and sometimes devastating consequences. Awareness of this injury has increased dramatically in recent years, and our understanding of its pathophysiology and treatment is rapidly evolving. This article reviews the current concepts of concussion pathophysiology and epidemiology, and will provide an overview of proper diagnosis and management. Complications and risk reduction also will be reviewed. By understanding the essentials of concussion medicine, health care professionals will be equipped to manage this injury, including common complications.

Analogue mouse pointer control via an online steady state visual evoked potential (SSVEP) brain-computer interface

The steady state visual evoked protocol has recently become a popular paradigm in brain-computer interface (BCI) applications. Typically (regardless of function) these applications offer the user a binary selection of targets that perform correspondingly discrete actions. Such discrete control systems are appropriate for applications that are inherently isolated in nature, such as selecting numbers from a keypad to be dialled or letters from an alphabet to be spelled. However motivation exists for users to employ proportional control methods in intrinsically analogue tasks such as the movement of a mouse pointer. This paper introduces an online BCI in which control of a mouse pointer is directly proportional to a user's intent. Performance is measured over a series of pointer movement tasks and compared to the traditional discrete output approach. Analogue control allowed subjects to move the pointer faster to the cued target location compared to discrete output but suffers more undesired movements overall. Best performance is achieved when combining the threshold to movement of traditional discrete techniques with the range of movement offered by proportional control.

Clinical trial resources on the internet must be designed to reach underrepresented minorities

PURPOSE

Internet-based clinical trial information services are being developed to increase recruitment to studies. However, there are limited data that evaluate their ability to reach elderly and underrepresented minority populations. This study was designed to evaluate the ability of an established clinical trials registry to reach these populations based on expected Internet use.

PATIENTS AND METHODS

This study compares general Internet users to participants who enrolled in an Internet based colorectal cancer clinical trials registry established by OncoLink (www.oncolink.org) and the National Colorectal Cancer Research Alliance. Observed rates of demographic groupings were compared to those established for general Internet users.

RESULTS

Two thousand, four hundred and thirty-seven participants from the continental United States used the Internet to register for the database. New England, the Mid-Atlantic region, and the Southeast had the highest relative frequency of participation in the database, whereas the Upper Midwest, California, and the South had the lowest rates. Compared to general Internet users, there was an overrepresentation of women (73% vs. 50%) and participants over 55 years old (27% vs. 14%). However, there was an underrepresentation of minorities (10.3% vs. 22%), particularly African Americans (3.1% vs. 8%) and Hispanics (2.8% vs. 9%).

DISCUSSION

The Internet is a growing medium for registry into clinical trials databases. However, even taking into account the selection bias of Internet accessibility, there are still widely disparate demographics between general Internet users and those registering for clinical trials, particularly the underrepresentation of minorities. Internet-based educational and recruitment services for clinical trials must be designed to reach these underrepresented minorities to avoid selection biases in future clinical trials.

Practical management: vocal cord dysfunction in athletes

Vocal cord dysfunction (VCD) is characterized by paradoxical adduction of the vocal folds during inhalation, and occasionally upon exhalation, resulting in extrathoracic airflow obstruction. Sports medicine professionals must have a high index of suspicion for VCD when acute respiratory symptoms occur so that prompt evaluation and use of appropriate specialists results in an accurate and timely diagnosis. Many factors have been implicated in the pathophysiology of VCD, including laryngeal irritants, psychogenic and neurogenic causes. The diagnosis and management of VCD involves a variety of specialties including pulmonology, otolaryngology, speech-language pathology, allergy and immunology, and psychologic management as appropriate. The mainstay of treatment remains behavioral management guided by a medical speech-language pathologist, as well as pharmacologic management for VCD triggers.

Common overuse tendon problems: A review and recommendations for treatment

There is a common misconception that symptomatic tendon injuries are inflammatory; because of this, these injuries often are mislabeled as "tendonitis."' Acute inflammatory tendinopathies exist, but most patients seen in primary care will have chronic symptoms suggesting a degenerative condition that should be labeled as "tendinosus" or "tendinopathy." Accurate diagnosis requires physicians to recognize the historical features, anatomy, and useful physical examination maneuvers for these common tendon problems. The natural history is gradually increasing load-related localized pain coinciding with increased activity. The most common overuse tendinopathies involve the rotator cuff, medial and lateral elbow epicondyles, patellar tendon, and Achilles tendon. Examination should include thorough inspection to assess for swelling, asymmetry, and erythema of involved tendons; range-of-motion testing; palpation for tenderness; and examination maneuvers that simulate tendon loading and reproduce pain. Plain radiography, ultrasonography, and magnetic resonance imaging can be helpful if the diagnosis remains unclear. Most patients with overuse tendinopathies (about 80 percent) fully recover within three to six months, and outpatient treatment should consist of relative rest of the affected area, icing, and eccentric strengthening exercises. Although topical and systemic nonsteroidal anti-inflammatory drugs are effective for acute pain relief, these cannot be recommended in favor of other analgesics. Injected corticosteroids also can relieve pain, but these drugs should be used with caution. Ultrasonography, shock wave therapy, orthotics, massage, and technique modification are treatment options, but few data exist to support their use at this time. Surgery is an effective treatment that should be reserved for patients who have failed conservative therapy.

A 3-week gemcitabine-cisplatin regimen for metastatic urothelial cancer

OBJECTIVE

To assess the efficacy and tolerability of a 3-week outpatient schedule of intravenous gemcitabine and cisplatin in patients with locally advanced unresectable or metastatic transitional cell carcinoma of the urothelial tract (TCC).

PATIENTS AND METHODS

A two-stage phase II trial enrolled TCC patients with Karnofsky performance status > or = 60, measurable disease, and adequate organ function. Prior adjunctive chemotherapy was allowed provided it had been completed at least 1 year prior to study entry. Treatment consisted of gemcitabine 1250 mg/m2 iv days 1 and 8 plus cisplatin 70 mg/m2 day 1 iv repeated every 21 days. The primary outcome was the objective response rate.

RESULTS

Thirty patients were enrolled at six Canadian centres. Three complete and 10 partial responses were observed in 29 eligible patients (overall response rate 45% [95%CI, 27-63%]). Three patients had stable disease and 13 had progressive disease. The relative dose-intensities of gemcitabine and cisplatin were 81% and 88%, respectively. Toxicity was primarily hematological, and 60% of patients experienced at least one episode of grade 3 or 4 toxicity. One patient died of neutropenic sepsis and two died of vascular events while on treatment.

CONCLUSIONS

The efficacy and tolerability of this schedule are similar to that reported with the standard 4-week schedule of gemcitabine-cisplatin. In the absence of a large randomized trial, the similarity of these results supports the use of this 3-week program in typical TCC patients treated in both community and academic cancer clinic settings.

Patterns of recurrence in patients treated with photodynamic therapy for intraperitoneal carcinomatosis and sarcomatosis

The purpose of this study was to evaluate the patterns of recurrence in patients treated with Photofrin-mediated intraperitoneal photodynamic therapy (IP PDT). Sixty-six patients with gastrointestinal cancers, ovarian cancers, and sarcomas have been enrolled to date and 51 patients underwent IP PDT. Photofrin, 2.5 mg/kg, was administered intravenously 48 h prior to surgical debulking and intraoperative light treatment. Forty-five, and 49 patients were evaluable for response rates, and patterns of recurrence, respectively. Response to treatment was evaluated by CT or MRI scans of the abdomen and pelvis every 3 months. Patterns of recurrence were determined by evaluating the abdomen as a combination of different treatment regions. Of the 51 patients enrolled and treated with IP PDT two are alive without evidence of recurrence. Eleven of 45 patients showed no evidence of recurrence 3 months after treatment. No evidence of recurrence was noted in 7/17 sarcoma patients, 2 of 13 ovarian cancer patients, and 2 of 15 gastrointestinal cancer patients. The most common site of recurrence as determined by radiographs was the pelvis, which was noted in 19 of 49 (39%) patients. The presence of gross residual disease before light treatment (as determined by the attending surgeon) did not affect the site of recurrence. When studying those patients who had only locoregional recurrence, 9 of 33 evaluated radiographically and 10 of 24 evaluated operatively recurred only in peritoneal areas not previously involved with gross disease. The pelvis was the site with the highest rate of recurrence after IP PDT. A significant minority of patients recurred only in sites not previously involved with gross disease. Patients with gross residual disease before light therapy had similar recurrence rates to those without gross residual disease. Since sites involved with gross residual tumor often received boost doses of light, this could suggest a dose-response relationship for IP PDT.

Attention deficit hyperactivity disorder (ADHD) and substance use disorders

Attention deficit hyperactivity disorder (ADHD) is a common childhood disorder that often continues to manifest symptoms into adulthood. In children and adults, this condition may contribute to addictive vulnerability. Several factors are common to the developmental psychopathology of these conditions, suggesting an underlying deficit in behavioral regulation as an explanation for this comorbidity. Developmentally, faulty learning processes or attempts to self-medicate dysfunctional behavior may contribute to the pathogenesis of substance use disorders. Substance abuse itself also may contribute to the development of attentional deficits and behavioral dysregulation through direct (eg, prenatal or self-inflicted exposures to neurotoxic substances) and indirect (eg, poverty, neglect, abuse) mechanisms. Because ADHD can be identified prior to the peak onset of substance use, effective treatment of this common disorder may reduce the development of substance use disorders. Adult ADHD may also contribute to the development and maintenance of substance use disorders Substance abuse patients may particularly benefit from treatment of this comorbidity.

Investigating hepatitis C virus heterogeneity in a high prevalence setting using heteroduplex tracking analysis

Hepatitis C virus (HCV) infection is very common among chronic hemodialysis patients. In the past, blood transfusion appeared to be the primary risk factor; however evidence of nosocomial HCV transmission in the hemodialysis setting has recently been reported. This report describes a molecular investigation of HCV isolates obtained from a population of 670 patients attending six different Seattle-King County based hemodialysis centers in order to identify potential common source infections. 733 serum specimens were collected from hemodialysis patients in 1992 and 1996, and were tested for HCV antibodies and RNA. Overall, 115 of 670 (17%) patients were positive for HCV RNA, and thus were considered actively infected by HCV. HCV genotype was determined in all cases by restriction fragment length polymorphism, and 93 patients were found to be infected by HCV genotype 1. HCV envelope genes were amplified from the 93 patients with genotype 1 infection, and were studied in further detail by heteroduplex tracking analysis (HTA) using genotype 1a and 1b specific probes derived from the envelope 1 (E1) and envelope 2 (E2) genes. Genetic relatedness between pairs of HCV envelope genes was estimated by calculating the degree of gel shift relative to homoduplex controls. Nucleotide sequencing and phylogenetic analysis was used to confirm genetic relatedness detected by HTA. When HTA was performed using the E1 gene probe, 12 apparently related infections were detected; 10 of 12 (83%) of these infections were confirmed as truly related using the gold standard method of nucleotide sequencing plus phylogenetic analysis. Using an E2 gene probe, 24 infections were apparently related, but only six (25%) were confirmed by sequencing. As a control, 41 envelope genes, which were unrelated by HTA, were sequenced; 0 of 41 (0%) were truly related. In summary, HTA provides a rapid and effective molecular technique for screening HCV genetic relatedness in population-based studies, and should prove valuable in future studies of HCV molecular epidemiology.

Substance abuse and criminal recidivism: a prospective study of adolescents

Studies of substance abuse among delinquents have shown mixed results on criminal recidivism. The present study evaluates personality traits associated with substance abuse and recidivism among delinquent boys, and prospectively determines the extent to which these factors are predictive of criminal recidivism. 134 incarcerated boys (x = 15.9 +/- 1.1) completed the Weinberger Adjustment Inventory and the Substance Abuse Screening Inventory. Youth were prospectively followed for up to 4.5 years following release. Among incarcerated delinquents, personality traits are predictive of a positive substance abuse screen and recidivism. A trend indicating a possible interaction between personality and treatment is observed. If these findings are replicated, personality traits may play a role in predicting substance abuse as well as individual delinquent responses to treatment.

Differential regulation of mammalian brain-specific proline transporter by calcium and calcium-dependent protein kinases

1. This study examined the role of [Ca2+]I and Ca(2+)-dependent kinases in the modulation of high-affinity, mammalian brain-specific L-proline transporter (PROT). 2. beta-PMA (phorbol 12-myristate 13-acetate), an activator of protein kinase C (PKC), inhibits PRO uptake, and bisindolymalemide I (BIM), a potent PKC inhibitor, prevents beta-PMA inhibition. Down-regulation of PKC by chronic treatment with beta-PMA enhances PROT function indicating PROT regulation by tonic activity of PKC. 3. Thapsigargin, which increases [Ca2+]I levels by inhibiting Ca(2+)-ATPase, inhibits PROT and exhibits additive inhibition when co-treated with beta-PMA. KN-62, a Ca2+/calmodulin-dependent kinase II (CaMK II) inhibitor, but not BIM (a PKC inhibitor) prevents the inhibition by thapsigargin. These data suggest that PKC and CaMK II modulate PROT and that thapsigargin mediates its effect via CaMK II. 4. Thapsigargin raises [Ca2+]I and increases PRO-induced current on a second time scale, whereas the inhibitory effect of thapsigargin occurs only after 10 min of treatment. These data suggest that Ca2+ differentially regulate PROT: Ca2+ initially enhances PRO transport but eventually inhibits transport function through CaMK II pathway. 5. Ca(2+)-induced stimulation exemplifies the acute regulation of a neurotransmitter transporter, which may play a critical role in the profile of neurotransmitters during synaptic transmission.

Relationship between iron concentration and hepatitis C virus RNA level in liver tissue

Patients with chronic hepatitis C virus (HCV) infection frequently have increased hepatic iron stores. The role of hepatitis C in hepatic iron deposition is unknown. The authors examined whether there is a relation between hepatitis C virus level in liver tissue and hepatic iron concentration. Forty-two paired samples obtained from the liver explants of five patients who underwent transplantation for liver disease due to hepatitis C were studied. Hepatitis C virus levels were measured at multiple sites within each liver by a branched deoxyribonucleic assay. Measurements of hepatic iron concentration were made at adjacent sites by a colorimetric assay. Random effects modeling showed wide intrahepatic variation in hepatic HCV ribonucleic acid (RNA) concentration (variance = 1.2 x 10(4) [mEq/g]2) and hepatic iron concentration (variance = 1.3 x 10(6) [microg/g]2). There was, however, a trend toward an association between the mean HCV level and the mean hepatic iron concentration for each liver (r = 0.30, p = 0.05). In conclusion, HCV level and iron concentration varied within and between cirrhotic livers. Variability in intrahepatic iron concentration was not related to variability in intrahepatic HCV RNA concentration. More studies are needed to determine the cause of variability in hepatic iron and HCV RNA concentration within and between livers in patients with chronic hepatitis C.

Homeopathy in rehabilitation medicine

Rehabilitationists must be able to assess not only the diagnostic entity, but also the person who is sick. The rehabilitation community's understanding of the holism involved in healing and the limitations of conventional therapies creates an openness to consider the usefulness of unconventional therapies. This article explores the role of homeopathy in rehabilitation medicine.

Multigene tracking of hepatitis C virus quasispecies after liver transplantation: correlation of genetic diversification in the envelope region with asymptomatic or mild disease patterns

To investigate the role of hepatitis C virus (HCV) quasispecies mutation in the pathogenesis of HCV infection, we analyzed changes in the genetic diversity of HCV genomes in 22 patients before and after liver transplantation by using heteroduplex mobility assay (HMA) technology. All patients were infected with HCV genotype 1 and developed high-titer posttransplant viremia. Each patient was classified according to the severity of posttransplant hepatitis, as assessed by standard biochemical and histological criteria. HCV quasispecies were characterized by HMA analysis of eight separate subgenomic regions of HCV, which collectively comprise 44% of the entire genome. The glycoprotein genes E1 and E2, as well as the nonstructural protein genes NS2 and NS3, had the greatest genetic divergence after liver transplantation (the change in the heteroduplex mobility ratio [HMR] ranged from 2.5 to 7.0%). In contrast, genes encoding the core, NS4, and NS5b proteins had the least amount of genetic divergence after liver transplantation (range, 0.3 to 1.2%). The E1/E2 region showed the greatest change in genetic diversity after liver transplantation, and the change in HMRs was 2.5- to 3.3-fold greater in patients with asymptomatic or moderate disease than in those with severe disease. The E1-5' region of HCV quasispecies isolated from patients in the asymptomatic group had a significantly greater degree of diversification after liver transplantation than the same regions of HCV quasispecies isolated from patients in the severe disease group (P = 0.05). While changes in the genetic diversity of some nonstructural genes were also greater in asymptomatic patients or in patients with mild disease than in patients with severe disease, the results were not significant. Data from this cohort demonstrate that greater rates of HCV quasispecies diversification are associated with mild or moderate liver disease activity in this immunosuppressed population.

Na+-coupled alanine transport in LLC-PK1 cells: the relationship between the Km for Na+ at low [Alanine] and potential dependence for the system

Analysis of the mechanistic basis by which sodium-coupled transport systems respond to changes in membrane potential is inherently complex. Algebraic expressions for the primary kinetic parameters (Km and Vmax) consist of multiple terms that encompass most rate constants in the transport cycle. Even for a relatively simple cotransport system such as the Na+/alanine cotransporter in LLC-PK1 cells (1:1 Na+ to substrate coupling, and an ordered binding sequence), the algebraic expressions for Km for either substrate includes ten of the twelve rate constants necessary for modeling the full transport cycle. We show here that the expression of Km of the first-bound substrate (Na+) simplifies markedly if the second-bound substrate (alanine) is held at a low concentration so that its' binding becomes the rate limiting step. Under these conditions, the expression for the KNam includes rate constants for only two steps in the full cycle: (i) binding/dissociation of Na+, and (ii) conformational 'translocation' of the substrate-free protein. The influence of imposed changes in membrane potential on the apparent KNam for the LLC-PK1 alanine cotransporter at low alanine thus provides insight to potential dependence at these sites. The data show no potential dependence for KNam at 5 micron alanine, despite marked potential dependence at 2 mm alanine when the full algebraic expression applies. The results suggest that neither translocation of the substrate-free form of the transporter nor binding/dissociation of extracellular sodium are potential dependent events for this transport system.

Coping strategies and laboratory pain in children with sickle cell disease

Studies have found that coping strategies are significant predictors of pain report, health care use, and psychosocial adjustment in children with sickle cell disease (SCD); however, the mechanisms of the relationship are not clear. In this study, 41 children with SCD completed a laboratory pain task to analyze their pain perception under standardized conditions. Sensory decision theory analyses were used to analyze the pain perception data. Children and their parents also completed measures of coping strategies and adjustment. Hierarchical regression analyses controlling for the child's age indicated that children who reported using active cognitive and behavioral coping strategies had a lower tendency to report pain during the laboratory pain task. Results are discussed in terms of the utility of using laboratory pain models with children and the need for future intervention studies to target coping strategies in children with SCD pain.

Oceanographic lidar attenuation coefficients and signal fluctuations measured from a ship in the Southern California Bight

We measured the attenuation coefficient of the National Oceanic and Atmospheric Administration lidar from a ship in the Southern California Bight in September 1995. The region from approximately 5 to 30 m in depth was covered. The laser was linearly polarized, and the receiver was operated with the same polarization and the orthogonal polarization. The measured values were between 0.08 and 0.12 m(-1) and were highly correlated with in situ measurements of the beam attenuation coefficient. Fluctuations of the lidar signal were found to be induced primarily by surface waves whose wavelengths are approximately three times the lidar spot size at the surface.

Starvation depresses acylglycerol biosynthesis in bovine subcutaneous but not intramuscular adipose tissue homogenates

The primary objective of this study was to document the effects of starvation on acylglycerol biosynthesis in homogenates of intramuscular and subcutaneous adipose tissues. Adipose tissue samples were obtained from 8th-13th thoracic rib sections from 12 Angus cattle (six steers plus six heifers). Three steers and three heifers were starved for 72 h prior to slaughter while the remainder were slaughtered 4 h after food was withheld. Fat-free 700 x g centrifugal fractions were used to measure the esterification of radiolabeled sn-glycerol 3-phosphate (G-3-P) into acylglycerols at 1.0 mM palmitic or stearic acid, or 0.2 mM oleic, linoleic, or alpha-linolenic acid. There were significant tissue x fatty acid interactions for rates of incorporation into diacylglycerols and triacylglycerols; in subcutaneous, but not intramuscular homogenates, palmitic > stearic = oleic = linoleic = alpha-linolenic acid. Subcutaneous homogenates incorporated a greater percentage of G-3-P into triacylglycerols, and a lesser percentage into phospholipid, than intramuscular homogenates (P < 0.05). In intramuscular homogenates, the primary product of G-3-P esterification to saturated fatty acids was phospholipids. When unsaturated fatty acid served as substrates, triacylglycerols and phospholipids were produced in equal proportions in intramuscular homogenates, and triacylglycerols were the predominant product in subcutaneous homogenates. Intramuscular adipose tissue homogenates exhibited no response to starvation, whereas triacylglycerol and diacylglycerol synthesis was depressed by approximately 50% in subcutaneous adipose tissue homogenates. Similarly, phosphatidic phosphohydrolase activity, initially greater in subcutaneous than in intramuscular adipose tissue, was decreased by approximately 50% by starvation in subcutaneous adipose tissue, but not in intramuscular adipose tissue. We conclude that differences in rates of diacylglycerol and triacylglycerol biosynthesis, and response to starvation, between intramuscular and subcutaneous adipose tissues were due to dissimilarities in the activity of phosphatidic phosphohydrolase.