Not a simple fat-soluble vitamin: Changes in serum 25-(OH)D levels are predicted by adiposity and adipocytokines in older adults

OBJECTIVE

To determine the associations between body adiposity and change in serum 25-(OH)D levels over 2.6 years, and if these associations are mediated by metabolic and inflammatory factors in older adults.

METHODS

This is a longitudinal study of 859 randomly selected subjects (mean 62 years, range 51-80, 49% women). Serum 25-hydroxyvitamin D [25-(OH)D] was assessed by radioimmunoassay at baseline and 2.6 years later. Baseline serum level of leptin was assessed by radioimmunoassay and interleukin (IL)-6 by a chemiluminescent immunoassay in the first 183 subjects.

RESULTS

In multivariable analyses, body mass index, trunk fat percentage and waist-to-hip ratio were significant predictors of increased incident vitamin D deficiency [a 25-(OH)D < 50 nmol L⁻¹ at follow-up when ≥50 nmol L⁻¹ at baseline] and decreased recovery of vitamin D deficiency [a 25-(OH)D ≥ 50 nmol L⁻¹ at follow-up when < 50 nmol L⁻¹ at baseline]. Change in 25-(OH)D levels per annum was also independently predicted by baseline leptin (β: -0.09/unit, 95% CI: -0.17, -0.03), IL-6 (β: -0.68/quartile, 95% CI: -1.35, -0.02) and total cholesterol/high-density lipoprotein (HDL) ratio (β: -0.51, 95% CI: -0.88, -0.14). The associations between body adiposity measures and change in 25-(OH)D completely disappeared after adjustment for leptin, diminished after adjustment for IL-6, but remained unchanged after adjustment for total cholesterol/HDL ratio. All associations were independent of season and sun exposure.

CONCLUSIONS

Body fat is not simply a passive reservoir for 25-(OH)D. In addition to season and sun exposure, 25-(OH)D levels appear to be determined by metabolic and, to a lesser extent, inflammatory factors, and these appear to mediate the effects of adiposity on change in 25-(OH)D.

Promoter polymorphisms in the β-2 adrenergic receptor are associated with drug-induced gene expression changes and response in acute lymphoblastic leukemia

We investigated whether genetic polymorphisms in the promoter region of the proapoptotic β-2 adrenergic receptor gene (ADRB2) influence treatment-induced changes in ADRB2 expression in leukemia cells and response to chemotherapy. The ADRB2 promoter region was genotyped in germline DNA from 369 children with acute lymphoblastic leukemia (ALL). For 95 of the patients, sufficient RNA was available before and after in vivo treatment to assess treatment-induced gene expression changes in ALL cells. After treatment, the median ADRB2 mRNA expression was ninefold lower in leukemia cells of patients who ultimately relapsed as compared with patients who remained in continuous complete remission (CCR). Polymorphisms in the ADRB2 promoter were significantly linked to methotrexate (MTX)-induced upregulation in ADRB2 gene expression in ALL cells. Moreover, the ADRB2 promoter haplotype was significantly related to early treatment response in 245 children with ALL who received uniform treatment. We conclude that germline polymorphisms in ADRB2 are linked to the antileukemic effects of ALL chemotherapy.

Associations between the genetic polymorphisms of MTHFR and outcomes of methotrexate treatment in rheumatoid arthritis

OBJECTIVES

To determine whether 5, 10-methylenetetrahydrofolate reductase (MTHFR) rs1801133C/T, rs1801131A/C, rs2274976A/G, rs2066462C/T genetic polymorphisms are associated with clinical response and adverse effects (AEs) of methotrexate (MTX) treatment in Chinese Han patients with rheumatoid arthritis (RA).

METHODS

One hundred and ten RA patients defined by the American College of Rheumatology (ACR) 1987 revised criteria were involved in this study. All patients were treated with low-dose MTX (10-15 mg/week) without concomitant uses of other DMARDs. Clinical response (using ACR20 criteria) and AEs were evaluated at 0, 4, 12, 16 and 24 weeks. The genotypes of MTHFR rs1801133C/T, rs1801131A/C, rs2274976A/G and rs2066462C/T were detected by real-time fluorescent quantitative PCR.

RESULTS

The allele frequency of rs1801131C in the clinical response group was higher than in the non-response group (21.0% vs. 8.1%, p<0.05), and the patients with CC or AC genotype had greater clinical response than those with AA genotype. The allele frequencies of rs1801133T and rs2274976A were higher in the group with AEs than that without AEs (56.4% vs. 37.5% and 14.9% vs. 4.2%, respectively, both p<0.05). The patients with CT or TT genotype in rs1801133 had higher risks of AEs than those with CC genotype.

CONCLUSIONS

While rs1801131A/C genetic polymorphism is associated with the clinical response, rs1801133C/T and rs2274976A/G genetic polymorphisms are associated with MTX-related AEs in the treatment of RA. This suggests individualisation is necessary to achieve optimal outcomes in MTX therapy of RA.

Activation of transient receptor potential vanilloid subtype 1 increases secretion of the hypofunctional, transplanted submandibular gland

Hyposecretion occurs in most patients early after submandibular gland autotransplantation for severe keratoconjunctivitis sicca. Endogenous transient receptor potential vanilloid subtype 1 (TRPV1) has been recently demonstrated in rabbit submandibular glands, and activation of TRPV1 by capsaicin increases secretion in isolated glands, but the TRPV1-mediated secretory mechanism remains to be elucidated. The purpose of this study was to verify whether activation of TRPV1 by capsaicin could improve the secretion of transplanted gland and its underlying mechanism. The salivary flow of the transplanted glands was significantly decreased, and the mRNA and protein levels of TRPV1 and aquaporin 5 (AQP5) were downregulated in the transplanted glands. Topical capsaicin cream increased secretion and upregulated levels of TRPV1 and AQP5 in transplanted glands. Moreover, in cultured submandibular gland cells, capsaicin increased the mRNA expression of AQP5 and led to redistribution of AQP5 from the cytoplasm to the plasma membrane via TRPV1 activation. Capsaicin enhanced the phosphorylation of extracellular signal-regulated kinase (ERK). Preincubation of cells with PD98059, an inhibitor of ERK kinase, suppressed the capsaicin-induced mRNA expression of AQP5. In summary, the capsaicin-induced secretory mechanism involved activation of TRPV1 and upregulation of AQP5 in an ERK-dependent manner and promoted the redistribution of AQP5 in submandibular gland cells. Activation of TRPV1 may provide a new therapeutic strategy to improve submandibular gland hypofunction.

Functional Vanilloid Receptor-1 in Human Submandibular Glands

Vanilloid receptor-1 (VR1) was originally found in the nervous system. Recent evidence indicates that VR1 is also expressed in various cell types. We hypothesized that VR1 exists in the human submandibular gland (SMG) and is involved in regulating salivary secretion. VR1 mRNA and protein were expressed in human SMGs and a human salivary intercalated duct cell line. VR1 was mainly located in serous acinar and ductal cells, but not in mucous acinar cells. Capsaicin, an agonist of VR1, increased intracellular free calcium, enhanced phosphorylation of extracellular signal-regulated kinase, and induced the trafficking of aquaporin 5 (AQP5) from the cytoplasm to the plasma membrane. These effects were abolished by pre-treatment with the VR1 antagonist capsazepine. Furthermore, capsaicin cream applied to the skin covering the submandibular area increased salivary secretion. These findings indicated that a functional VR1 is expressed in the human SMG and is involved in regulating salivary secretion by mediating AQP5 trafficking.

A pilot study of the reproducibility and validity of measuring knee subchondral bone density in the tibia

OBJECTIVE

To describe the reproducibility and validity of six different measurement techniques for knee subchondral bone mineral density (sBMD).

METHODS

A consecutive sample of 50 male and female participants from a population-based longitudinal study had sBMD assessed using dual energy X-ray absorptiometry scans. Anthropometric, knee pain, cartilage and bone measures by magnetic resonance imaging and radiographic osteoarthritis (OA) were assessed. The six methods were defined as: (1) the midpoint of one intercondylar spine, across the tibial surface and descending 10mm; from the midpoint of the two intercondylar spines (2) the top of the spine descending 20mm, (3) 10-20mm beneath the top of the spine; from the tibial surface descending, (4) 10mm, (5) 15 mm, and (6) 20mm.

RESULTS

All six methods had excellent reproducibility (intra-class correlation coefficient 0.98-1.00). sBMD was higher in males (methods 2-4) and higher in those with medial tibial osteophytes (methods 1, 3 and 4). Medial tibial cartilage defects and overall cartilage defects correlated with sBMD (methods 3 and 4). Method 2, which includes the intercondylar spine, correlated with medial tibial bone size. Measuring sBMD using methods 3 and 4 produced the greatest number of associations with joint features of OA.

CONCLUSIONS

These preliminary results need confirmation in larger longitudinal samples but suggest that sBMD can be accurately measured and plays a role in knee OA. Methods 3 and 4 had the best concurrent validity; however, method 2 adds additional information on tibial bone size, suggesting that two measures are necessary in clinical studies.

Direct imaging of aligned neurofilament networks assembled using in situ dialysis in microchannels

We report a technique to produce aligned neurofilament networks for direct imaging and diffraction studies using in situ dialysis in a microfluidic device. The alignment is achieved by assembling neurofilaments from protein subunits confined within microchannels. Resulting network structure was probed by polarized optical microscopy and atomic force microscopy, which confirmed a high degree of protein alignment inside the microchannels. This technique can be expanded to facilitate structural studies of a wide range of filamentous proteins and their hierarchical assemblies under varying assembly conditions.

Two-year prospective longitudinal study exploring the factors associated with change in femoral cartilage volume in a cohort largely without knee radiographic osteoarthritis

OBJECTIVE

To identify factors associated with change in femoral cartilage volume over 2 years in a cohort largely without knee radiographic osteoarthritis.

METHODS

A total of 252 subjects (mean 45 years, range 28-60) were used for this study. T1-weighted fat saturation magnetic resonance imaging was performed at baseline and approximately 2 years later. Knee femoral condyle cartilage volume, femoral cartilage defect (0-4 scale) and tibial bone size were determined.

RESULTS

The total femoral cartilage volume loss was 6.3% for the 2.3-year period. Factors associated with this annual change were female gender (females vs males: -1.69%, P<0.01), age (over vs under 40 years: -0.96%, P=0.01), smoking (beta: -0.04% per pack-years, P<0.01), as well as lower limb muscle strength (r: +0.32, P<0.01) and its change (beta: +0.34% per quartile, P<0.05). Structural factors associated with change included baseline femoral cartilage volume (beta: -0.36% per ml, P<0.01), femoral cartilage defects (beta: +1.07% per grade, P<0.01), tibial bone area (beta: +0.13% per cm(2), P<0.05), lateral osteophytes (beta: -1.91% per grade, P<0.01) and change in femoral cartilage defects (beta: -0.8% per grade, P<0.001).

CONCLUSIONS

This study provides evidence confirming that significant risk factors are associated with femoral cartilage loss and these include gender (female), age, smoking, and severity of lower limb muscle weakness. It also supports the hypothesis that femoral cartilage swelling reflected by an increased baseline cartilage volume could be a predictor of disease progression. Our findings also provide interesting clues to implement preventive measures that can possibly prevent or reduce knee cartilage loss.

The natural history of cartilage defects in people with knee osteoarthritis

OBJECTIVES

Cartilage defects are highly prevalent in subjects with knee osteoarthritis (OA). Although they are associated with increased cartilage loss and joint replacement, there is little data on the natural history of cartilage defects. The aim of this study was to examine the progression of cartilage defects over 2 years in people with knee OA and to identify factors associated with progression.

METHODS

One hundred and seventeen subjects with OA underwent magnetic resonance imaging of their dominant knee at baseline and follow-up. Cartilage defects were scored (0-4) at four sites. Bone size of the medial and lateral tibial plateau was determined. Height, weight, body mass index and physical activity were measured by standard protocols.

RESULTS

The mean cartilage defect score increased significantly over the 2-year study period in all tibiofemoral compartments (all P<0.001), except the lateral tibial compartment with age and tibial plateau bone area at baseline being predictors of progression. However, there was heterogeneity with 81% progressing at any site, 15% remaining stable and 4% decreasing.

CONCLUSION

Over 2 years, cartilage defects tend to progress in people with symptomatic OA, with only a small percentage decreasing in severity. Increasing age and increased bone area are risk factors for progression. Interventions aimed at preventing cartilage defects from occurring and reducing their severity may result in a reduction in the severity of OA, by reducing loss of articular cartilage and subsequent requirement for knee joint replacement.

Meniscal tear and increased tibial plateau bone area in healthy post-menopausal women

OBJECTIVE

Meniscal tears detected using magnetic resonance imaging (MRI) have been identified as a risk factor for the development and progression of Osteoarthritis, however the prevalence and significance of meniscal tears in healthy, asymptomatic adults remains to be studied. We investigated the prevalence of meniscal tears in a healthy pain free population of post-menopausal women and whether meniscal tears in this population are associated with changes in cartilage volume and defects and tibial plateau bone area over 2 years.

METHODS

Fifty-seven post-menopausal women underwent MRI of their dominant knee at baseline line and approximately 2 years later to assess meniscal tears, cartilage volume, cartilage defects and tibial plateau bone area.

RESULTS

Forty-six percent of women had a meniscal tear in either the medial and/or lateral compartment. Women who had a tear were older (P=0.01) and had more lateral cartilage defects (P=0.02). Medial meniscal tear was associated with 103 mm(2) greater tibial plateau bone area within the medial [95% confidence of interval (CI) 6.2, 200.3; P=0.04] and a lateral meniscal tear with a 120 mm(2) greater area within the lateral compartment (95% CI 45.5, 195.2; P=0.002).

CONCLUSION

This study demonstrates that meniscal tears are common in asymptomatic post-menopausal women and that they become more common with age. Meniscal tears were also associated with greater tibial plateau bone area but not cartilage volume, providing support to the hypothesis that tibial plateau bone changes occur before significant pathological changes in cartilage. Whether increased tibial plateau bone area predisposes to an increased risk of degenerative meniscal tears or whether it is a consequence of altered biomechanical forces in relation to meniscal tear will need to be determined.

Tibial subchondral bone size and knee cartilage defects: relevance to knee osteoarthritis

Unlike knee plain radiography which can only detect joint space narrowing and osteophytes, magnetic resonance imaging can directly visualize and analyse the whole knee structure, including bone size, cartilage defects and loss of cartilage volume. Tibial subchondral bone area expansion may be primary and is associated with risk factors such as age, body mass index (BMI), genetics and/or limb malalignment. It can lead to the development of knee defects, which may also be caused by demographic, anthropometric and environmental factors such as age, female sex, BMI and smoking as well as structural changes such as osteophytes, bone marrow lesions, meniscal tears, meniscal extrusion and ligament abnormalities. Once knee cartilage defects develop, they have a variable natural history but are associated with subsequent cartilage loss in a dose-response manner. Both tibial subchondral bone area and knee cartilage defects are quantitatively related to the severity of knee osteoarthritis (OA), and predictive of the need for knee joint replacement in subjects with knee OA independent of radiographic change. Taken as a whole, these studies suggest that tibial subchondral bone expansion and cartilage defect development represent important targets for the prevention of cartilage loss and joint replacement.

Intracardiac echocardiographic measurement of left ventricular volume

We tested the utility of intracardiac echocardiography (ICE) in measuring left ventricular (LV) volume. In 4 normal dogs, a 10-F percutaneous sheath was placed inside the LV along its major axis. An ICE catheter (9 F, 9 MHz) was then inserted through the sheath into the LV. The ICE catheter was pulled back in 1-mm intervals starting from the apex, and 2-D tomographic images were continuously acquired. Subsequently, the ICE catheter was replaced in the LV by a conductance catheter to measure single-beat volume signals. Stroke volume was determined by thermodilution for validation. All measurements were made in each dog while pacing the atrium at two different cycle lengths (range=300-500 ms). The endocardium was segmented in the ICE images throughout the cardiac cycle, and LV volume was computed by integrating multiple segments (range=55-70 mm). We found that ICE accurately reconstructed LV 3-D anatomy. Stroke volume by ICE was in excellent agreement with thermodilution (error = 3.8+/-3.0%, r = 0.99, n = 8). Morphology of LV volume signals correlated well with instantaneous volume signals derived by conductance (r=0.93, n=8). In conclusion, ICE accurately reconstructs LV anatomy and volume throughout the cardiac cycle in the normal heart. This approach could facilitate interventional diagnostic and therapeutic procedures.

Semi-automatic segmentation of the endocardial boundary in intracardiac echocardiographic images

Intracardiac echocardiograpby (ICE) has been employed in guiding clinical interventional procedures. ICE could also be useful for 3-D anatomical and functional imaging of the heart. In this regard, we developed and tested a method to semi-automatically determine the endocardial boundary in multiple tomographic ICE images. Compared to manual segmentation, we found that semi-automatic segmentation of the endocardial boundary in ICE images was feasible and enabled accurate and efficient reconstruction of 3-D geometry of the heart cavity.

A phase I study of IMC-11F8, a fully human anti-epidermal growth factor receptor (EGFR) IgG1 monoclonal antibody in patients with solid tumors. Interim results

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Background: This ongoing phase I study is being conducted to determine the safety profile and recommended dose of IMC-11F8, a fully-human IgG1 monoclonal antibody that targets the EGFR. Methods: Patients (pts) with advanced solid tumors who are refractory to or have no available standard therapy are eligible to receive IMC-11F8 intravenously either weekly or every other week for 6 weeks (1 cycle). The initial cohort of patients will receive 100 mg of IMC-11F8. In the absence of a dose-limiting toxicity (DLT), dose escalation will be 200, 400, 600, 800, and 1000 mg in successive cohorts. Prior to the initial cycle, pts receive one IMC-11F8 infusion at their assigned cohort followed by a 2-week pharmacokinetic (PK) period. Pts with stable disease or better after cycle 1 are eligible to receive additional cycles of IMC-11F8. Results: 31 of 40 pts have been enrolled in the 100-, 200-, 400-, 600-, and 800-mg cohorts. Pt characteristics are M/F 20/11, median age 58 years (37 - 76), median ECOG score 1 (0–2). No DLTs have been observed. Only grade 1/2 skin rashes were reported. The most frequent adverse events were nausea, vomiting, fatigue, and headache. No infusion reactions were observed. 2 pts (1 confirmed) have achieved a PR, 1 pt with melanoma in the 200-mg cohort with 39+ weeks of weekly IMC-11F8 treatment and 1 pt with rectal cancer in the 400-mg cohort with 20+ weeks of IMC-11F8 administered every other week. 5 pts in the 200- to 600-mg cohorts have stable disease and have received from 11+ to 35+ weeks of IMC-11F8 treatment. A noncompartmental analysis of 20 pts demonstrated that IMC-11F8 exhibits nonlinear PK. As IMC-11F8 escalated from 100 to 600 mg, T1/2 increased from 67 to 84 hrs, Cmax increased from 30 to 368 μg/mL, AUCinf increased from 1753 to 67295, and CL decreased from 57.0 to 8.9 mL/hr. Conclusions: These interim results indicate that IMC-11F8 is well tolerated in this patient population. Although a maximum tolerated dose has not been established, IMC-11F8 has shown activity at two different dose levels.

[Table: see text]

Factors affecting progression of knee cartilage defects in normal subjects over 2 years

OBJECTIVES

Cartilage defects are present in subjects with knee osteoarthritis (OA). Although they are often present in healthy subjects, there is little data on the natural history of cartilage defects. The aim of this study was to examine the change in cartilage defects over 2 yr and to identify factors associated with this change.

METHODS

One hundred and twenty-four healthy subjects underwent magnetic resonance imaging of their dominant knee at baseline and follow-up. Cartilage defects were scored (0-4) at five sites. Bone size was determined at medial and lateral tibial plateau and patella. Height, weight, body mass index and physical activity were measured by standard protocols.

RESULTS

Eighty-six subjects completed the study. The mean cartilage defect score of each tibiofemoral compartment increased over time. However, medial and lateral tibiofemoral defect score decreased in 5% of the subjects. Cartilage defects were more likely to progress in males than females in each individual compartment (P<0.001 for medial tibiofemoral, P=0.005 for lateral tibiofemoral and P=0.01 for patellar cartilage). Baseline cartilage defect score was negatively associated with the progression of cartilage defects in each compartment (all P<0.001).

CONCLUSION

Although knee cartilage defects progressed over time in the majority of normal subjects, those of the highest severity tended to regress. Male gender and baseline cartilage defect score were the main factors associated with the progression of cartilage defects. Larger studies will be required to identify factors associated with the progression and regression of lesions.

The clinical correlates of articular cartilage defects in symptomatic knee osteoarthritis: a prospective study

OBJECTIVES

To determine whether articular cartilage defects are associated with cartilage loss and joint replacement in subjects with symptomatic knee osteoarthritis (OA).

METHODS

One hundred and seventeen subjects with symptomatic knee OA underwent magnetic resonance imaging of their dominant knee at baseline and 2 yr later. Cartilage defects were identified as prevalent (defect score > or =2) in each knee compartment. Occurrence of joint replacement by 4 yr was documented.

RESULTS

Cartilage defects were present in 81% of medial, 64% of lateral tibiofemoral compartments and 55% of patellar cartilages. Annual patellar cartilage loss was highest in those with defects compared with no defects (5.5% vs 3.2%, P = 0.01). Tibial cartilage loss was not associated with defects in the medial (4.6% vs 5.8%, P = 0.42) or lateral (4.7% vs 6.5%, P = 0.21) tibial cartilages. Higher total cartilage defect scores (8-15) were associated with a 6.0-fold increased risk of joint replacement over 4 yr compared with those with lower scores (2-7) (95% confidence interval 1.6, 22.3), independently of potential confounders.

CONCLUSIONS

Articular cartilage defects are associated with disease severity in knee OA and predict patellar cartilage loss and knee replacement.

Ion excitation in a linear quadrupole ion trap with an added octopole field

Modeling of ion motion and experimental investigations of ion excitation in a linear quadrupole trap with a 4% added octopole field are described. The results are compared with those obtained with a conventional round rod set. Motion in the effective potential of the rod set can explain many of the observed phenomena. The frequencies of ion oscillation in the x and y directions shift with amplitude in opposite directions as the amplitudes of oscillation increase. Excitation profiles for ion fragmentation become asymmetric and in some cases show bistable behavior where the amplitude of oscillation suddenly jumps between high and low values with very small changes in excitation frequency. Experiments show these effects. Ions are injected into a linear trap, stored, isolated, excited for MS/MS, and then mass analyzed in a time-of-flight mass analyzer. Frequency shifts between the x and y motions are observed, and in some cases asymmetric excitation profiles and bistable behavior are observed. Higher MS/MS efficiencies are expected when an octopole field is added. MS/MS efficiencies (N(2) collision gas) have been measured for a conventional quadrupole rod set and a linear ion trap with a 4% added octopole field. Efficiencies are chemical compound dependent, but when an octopole field is added, efficiencies can be substantially higher than with a conventional rod set, particularly at pressures of 1.4 x 10(-4) torr or less.

Association between age and knee structural change: a cross sectional MRI based study

OBJECTIVE

To describe the associations between age, knee cartilage morphology, and bone size in adults.

METHODS

A cross sectional convenience sample of 372 male and female subjects (mean age 45 years, range 26-61) was studied. Knee measures included a cartilage defect five site score (0-4 respectively) and prevalence (defect score of > or =2 at any site), cartilage volume and thickness, and bone surface area and/or volume. These were determined at the patellar, medial, and lateral tibial and femoral sites using T(1)weighted fat saturation MRI. Height, weight, and radiographic osteoarthritis (ROA) were measured by standard protocols.

RESULTS

In multivariate analysis, age was significantly associated with knee cartilage defect scores (beta = +0.016 to +0.073/year, all p<0.01) and prevalence (OR = 1.05-1.10/year, all p<0.05) in all compartments. Additionally, age was negatively associated with knee cartilage thickness at all sites (beta = -0.013 to -0.035 mm/year, all p<0.05), and with patellar (beta = -11.5 microl/year, p<0.01) but not tibial cartilage volume. Lastly, age was significantly positively associated with medial and lateral tibial surface bone area (beta = +3.0 to +4.7 mm(2)/year, all p<0.05) and patellar bone volume (beta = +34.4 microl/year, p<0.05). Associations between age and tibiofemoral cartilage defect score, cartilage thickness, and bone size decreased in magnitude after adjustment for ROA, suggesting these changes are directly relevant to OA.

CONCLUSION

The most consistent knee structural changes with increasing age are increase in cartilage defect severity and prevalence, cartilage thinning, and increase in bone size with inconsistent change in cartilage volume. Longitudinal studies are needed to determine which of these changes are primary and confirm their relevance to knee OA.

Genetic mechanisms of knee osteoarthritis: a population based case-control study

OBJECTIVE

To compare subjects who had at least one parent with a total knee replacement for severe primary knee osteoarthritis with age and sex matched controls who had no family history of knee osteoarthritis

DESIGN

Population based case-control study of 188 matched pairs (mean age 45 years, range 26 to 60).

METHODS

Articular cartilage volume and bone size were determined at the patella and at the medial tibial and lateral tibial compartments by processing images acquired using T1 weighted, fat saturated magnetic resonance imaging. Radiographic osteoarthritis (ROA) was assessed from a standing semiflexed radiograph scored for joint space narrowing and osteophytosis. Knee pain was assessed by questionnaire. Height, weight, body mass index (BMI), lower limb muscle strength, and endurance fitness were measured by standard protocols.

RESULTS

Compared with the controls, index offspring had higher BMI (27.8 v 26.0 kg/m(2), p = 0.02), weaker lower limb muscles (127 v 135 kg, p = 0.006), more knee pain (47% v 22%, p<0.001), and greater medial tibial bone area (17.6 v 17.1 cm(2), p = 0.01). With the exception of BMI, these differences persisted in multivariate analysis. There was a non-significant trend to higher cartilage volume at tibial sites and increased ROA in the offspring in the total and subgroup analyses, but no difference in height and endurance fitness.

CONCLUSIONS

BMI, muscle strength, knee pain, and medial tibial bone area, but not cartilage volume, appear to play a role in the genetic regulation and development of knee osteoarthritis.

Serum lysophosphatidic acid concentrations measured by dot immunogold filtration assay in patients with acute myocardial infarction

In this study the relation between lysophosphatidic acid (LPA) and myocardial infarction was investigated, the typical and simplified methods for measuring serum LPA concentration by dot immunogold filtration assay (DIFA) based on a polyclonal antibody to LPA were developed, and serum LPA concentrations were measured in 31 patients with acute myocardial infarction (AMI) and 12 controls (blood donors) by DIFA. Serum LPA levels were raised more than twofold 8 h after the onset of AMI. Maximal elevation (10.43 mg/L) was found at 48-72 h following onset and remained higher than the control concentration (1.66 mg/L) 7 days after AMI. The rise in serum LPA concentration in AMI patients suggests that LPA might be involved in AMI-related pathophysiology in the cardiovascular system. The simplified DIFA developed in the present study for measuring serum LPA concentration is convenient and highly sensitive.

Neuroradiological findings in glutaric aciduria type I (glutaryl-CoA dehydrogenase deficiency)

This article summarizes the magnetic resonance imaging features of glutaric aciduria type I (GA I) based on the cases presented at the 3rd International Workshop on Glutaryl-CoA Dehydrogenase Deficiency together with a review of previously reported neuroimaging characteristics of GA I. Previous reports have focused on characteristic findings, such as basal ganglia injury and frontotemporal atrophy or hypoplasia, subdural effusions and white-matter disease. Most of these findings have been demonstrated in symptomatic children, i.e. after manifestation of acute encephalopathic crises. In contrast, prospective investigations in presymptomatically diagnosed children are rare. Since more recent investigations have highlighted CNS changes in patients without encephalopathic crises, systematic prospective investigations of neuroradiological findings in this disease are indispensable for a better understanding of this disease. Based on these findings a suggestion for a MRI protocol is presented, supporting a standardized evaluation of patients with GA I.

Effects of hyperglycemic and normoglycemic cerebral ischemia on phosphorylation of c-jun NH2-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK)

Transient global cerebral ischemia leads to delayed neuronal cell death in the hippocampal CA1, caudate putamen and neocortex. If preischemic hyperglycemia exists, the same duration of ischemia recruits additional brain structures, such as dentate gyrus to become damaged. The objective of the present study is to determine whether activation of mitogen-activated protein kinases (MAPKs) plays a role in hyperglycemia-mediated ischemic neuronal damage. Using phopho-specific antibodies against c-jun NH2-terminal kinase (JNK) and p38 MAPK, we studied activation of these two MAPKs in ischemia-vulnerable neocortex and ischemia-resistant dentate gyrus in rats subjected to 15 min of forebrain ischemia and followed by 0.5, 1 and 3 hr of recirculation under normo- and hyperglycemic conditions. The results showed that levels of phosphorylated JNK increased in both normo- and hyperglycemic brains following blood reperfusion for 0.5 hr and persisted up to 3 hr in the neocortex but not in the dentate gyrus, implying JNK may play a role in mediating neuronal cell death after ischemia. However, since hyperglycemia did not further increase phospho-JNK, JNK may not contribute to the detrimental effect of hyperglycemia on neuronal cell death. The amount of phospho-p38 was not altered by ischemia under both normo- and hyperglycemic conditions, suggesting that p38 MAPK may not play a major role in mediating neuronal damage in these two structures.

Sex differences in knee cartilage volume in adults: role of body and bone size, age and physical activity

OBJECTIVE

To test the hypothesis that sex differences in knee cartilage volume may be mediated through body and bone size, age and/or physical activity.

METHODS

A cross-sectional convenience sample of 372 subjects (males 43%; mean age 45 yr, range 26-61) was studied. Articular cartilage volumes and bone size were determined at the patella, medial and lateral tibia by processing images acquired in the sagittal plane using T1-weighted fat saturation magnetic resonance imaging. Height, weight, physical activity (lower limb muscle strength, endurance fitness and questionnaire items) and radiographic osteoarthritis (ROA) were measured.

RESULTS

Gender explained 33-42% of the variation in knee cartilage volumes (all P < 0.001). Males had 33-42% higher cartilage volume than females at all sites. In the whole group, the magnitude of sex differences decreased to 8-18% after adjustment for body height, weight and bone size, but remained significant (all P < 0.05). Further adjustment for physical activity had no effect on the sex differences. The sex differences in cartilage volume were greater in those aged over 50 compared with those aged under 50 (P < 0.05 for age-sex interaction at all sites) and were independent of ROA.

CONCLUSIONS

Men have substantially higher knee cartilage volumes than women. These sex differences appear to be mediated in part by body and bone size but a significant amount remains unexplained. Furthermore, the differences become more marked over the age of 50 yr suggesting that both cartilage development and cartilage loss in later life contribute to sex differences in cartilage volume. Further longitudinal studies in large samples will be required to confirm these findings.

Quantitative analysis of (styrene/acrylonitrile/methyl methacrylate) co-polymer systems by infrared resonance spectroscopy

A detailed careful analysis of the infrared resonance (IR) spectra of polystyrene (PSt), polymethyl methacrylate (PMMA), polyacrylonitrile (PAN) and their co-mixtures were performed. Through this study the absorption peak area to weight ratios as well as working curves were obtained to test for their reliability as well as their suitability. Satisfactory results were achieved and these working curves were then used to measure the polymerized components of binary and ternary co-polymers. By investigating the acquired data we conclude that the monomer preferential polymeric sequence is St > MMA > AN. A quantitative method to measure P (St/AN/MMA) concentrations by IR spectroscopy is proposed in this work.

Neuronal nitric oxide synthase and the autonomic innervation of the mouse lacrimal gland

PURPOSE

To determine the expression patterns of the vesicular acetylcholine transporter (VAChT), tyrosine hydroxylase (TH) and neuronal nitric oxide synthase (nNOS) in the pterygopalatine ganglion (PPG) and the exorbital lacrimal gland of normal mice.

METHODS

Mouse PPG and lacrimal glands were processed for single- and double-labeled indirect immunofluorescence studies. Slides were examined with conventional fluorescence microscopy and confocal laser scanning microscopy.

RESULTS

All the somata in the PPG expressed both VAChT and nNOS immunoreactivity (IR). The postganglionic axons within the ganglion showed less VAChT-immunoreactive intensity than that seen in the somata, whereas nNOS IR was almost undetectable. In the lacrimal gland, nNOS-positive nerve bundles and fibers were observed to be associated with tear-collecting ducts, blood vessels, and acini. Some nNOS-positive punctate elements appeared to be distributed among acini. Many nerve fibers were VAChT immunoreactive and a small number of fibers were TH immunoreactive in the gland. Most of the VAChT-positive fibers and some of the TH-positive nerves displayed nNOS IR.

CONCLUSIONS

The expression of nNOS in cells of the PPG and in lacrimal gland nerves suggests that NO may play a role in modulating tear production. The site of action may include the PPG, ducts, blood vessels, acini, nerve fibers, and myoepithelial cells within the gland. NO may modulate parasympathetic and/or sympathetic synaptic transmission or by acting directly on lacrimal gland components. The interaction between NO-ergic and the conventional autonomic input illustrates the complexity of the innervation pattern of the mouse lacrimal gland.

Familial isolated hypoparathyroidism caused by a mutation in the gene for the transcription factor GCMB

Hypoparathyroidism is characterized by hypocalcemia, hyperphosphatemia, and absent or markedly reduced circulating concentrations of parathyroid hormone. The transcription factor GCMB is predominantly, if not exclusively, expressed in parathyroid cells and is critical for development of the parathyroid glands in mice. Thus, in the present study we examined the GCMB gene, mapped to 6p23-24, as a candidate for isolated hypoparathyroidism. We defined the boundaries of the five exons of the human GCMB gene and then identified a large intragenic mutation in the GCMB genes of the proband of an extensive kindred with isolated hypoparathyroidism. Her parents and several other unaffected relatives were heterozygous for the mutation. Despite an absence of any history of consanguinity, microsatellite analysis showed shared genotypes that flanked the GCMB gene over a span of 5 cM, suggesting that both of the proband's GCMB alleles had been derived from a single common ancestor. Analysis of additional, unrelated cases did not disclose the same mutation. We conclude that homozygous loss of function of the GCMB gene impairs normal parathyroid gland embryology and is responsible for isolated hypoparathyroidism in a subset of patients with this disease.

[Role of cyclin D1 protein, p53 protein and DNA ploidy in judging malignancy and prognosis of lung cancer]

BACKGROUND

To study the role of cyclin D1, p53 Protein and DNA ploidy in judging the degree of malignancy and prognosis of lung cancer.

METHODS

Paraffin-embedded specimens from 40 lung cancer patients and 15 paracancerous normal lung tissues were examined by flow cytometry.

RESULTS

The positive rate of cyclin D1, p53 protein and aneuploidy was 62. 5%( 25/ 40) , 75% ( 30/ 40) and 77. 5%( 31/ 40) respectively. The levels of cyclin D1 protein and p53 protein in lung cancer tissues were significantly higher than those in normal lung tissues ( P < 0. 01) . Overexpression of cyclin D1, p53 protein and aneuploidy was related with tissue types, pathological grade, lymphatic metastasis and survival time.

CONCLUSIONS

Cyclin D1 protein and p53 protein play an important role in carcinogenesis of the lung. It is valuable to determine cyclin D1, p53 protein and aneuploidy for judging malignancy and prognosis of lung cancer patients.

Apatite formed on the surface of plasma-sprayed wollastonite coating immersed in simulated body fluid

Wollastonite coatings on titanium alloys substrates were prepared by plasma spraying and incubated in simulated body fluids for different periods to investigate the nucleation and growth of apatite on their surface. Surface structural changes of the specimens were analyzed by XRD and IR technologies. SEM and EDS were used to observe surface morphologies and determine the composition of wollastonite coatings before and after immersion in simulated body fluid. The changes in the concentrations of calcium, silicon and phosphorus in the simulated body fluids due to the immersion of the specimens were measured by inductively coupled plasma atomic emission spectroscopy. The results obtained showed that hydroxycarbonate apatite can be formed on the surface of the coating soaked in SBF for 1 day. With longer immersion periods, the coating surface was covered by hydroxycarbonate apatite, which indicated that the wollastonite coating possesses good bioactivity.

[The role of neutrophils and interleukin-8 in pathogenesis of asthma]

OBJECTIVE

To investigate the role of neutrophils and interleukin-8 (IL-8) in pathogenesis of asthma.

METHODS

Pulmonary function and bronchial provocation test were performed to identify and evaluate asthma. Superoxide anion O(2)(-.) generation of peripheral blood neutrophils, IL-8 and malondialhyde (MDA) levels in plasma and induced sputum were measured.

RESULTS

The O(2)(-.) generation [(20.9 +/- 5.1) nmol] of peripheral blood neutrophils from moderate-severe asthmatics were significantly higher than that [(15.2 +/- 4.2) nmol] from mild asthmatics (P < 0.01), in which that was still significantly higher than that [(11.3 +/- 2.4) nmol] from normal subjects (P < 0.05). The O(2)(-.) generation of peripheral blood neutrophils had significantly negative correlation with PD(20)FEV(1) (r = -0.693, P < 0.05). The levels of IL-8 [(585 +/- 75) ng/L, (791 +/- 103) ng/L] and MDA levels [(6.3 +/- 1.6) mmol/L, (21.8 +/- 6.3) mmol/L] in plasma and induced sputum from unstable asthmatics were higher than those [(227 +/- 54) ng/L, (322 +/- 95) ng/L and (5.4 +/- 1.0) mmol/L, (15.1 +/- 5.6) mmol/L] from stable asthmatics (P < 0.01), more over, in the latter group, they were still significantly higher than those (188 +/- 46) ng/L, (224 +/- 51) ng/L and [(4.1 +/- 0.4) mmol/L, (9.5 +/- 4.2) mmol/L] from normal subjects (P < 0.05). The levels of MDA in the induced sputum from stable asthmatics showed a negative correlation with PD(20)FEV(1) (r = -0.708, P < 0.01). The levels of IL-8 in the induced sputum showed a positive correlation with percentage of neutrophils in the induced sputum (r = 0.838, P < 0.01).

CONCLUSIONS

IL-8 and oxygen free radicals generated by neutrophils might participate in development of airway inflammation and airway hyperresponsiveness in asthma.

Treatment with a growth hormone secretagogue in a model of developing heart failure: effects on ventricular and myocyte function

BACKGROUND

Exogenous administration of growth hormone (GH) and subsequently increased production of insulin-like growth factor-1 can influence left ventricular (LV) myocardial growth and geometry in the setting of congestive heart failure (CHF). This study determined the effects of an orally active GH secretagogue (GHS) treatment that causes a release of endogenous GH on LV function and myocyte contractility in a model of developing CHF.

METHODS AND RESULTS

Pigs were randomly assigned to the following treatment groups: (1) chronic rapid pacing at 240 bpm for 3 weeks (n=11); (2) chronic rapid pacing and GHS (CP-424,391 at 10 mg x kg(-1) x d(-1), n=9); and (3) sham controls (n=8). In the untreated pacing CHF group, LV fractional shortening was reduced (21+/-2% versus 47+/-2%) and peak wall stress increased (364+/-21 versus 141+/-5 g/cm(2)) from normal control values (P:<0.05). In the GHS group, LV fractional shortening was higher (29+/-2%) and LV peak wall stress lower (187+/-126 g/cm(2)) than untreated CHF values (P:<0.05). With GHS treatment, the ratio of LV mass to body weight increased by 44% from untreated values. Steady-state myocyte velocity of shortening was reduced with pacing CHF compared with controls (38+/-1 versus 78+/-1 microm/s, P:<0.05) and was increased from pacing CHF values with GHS treatment (55+/-7 microm/s, P:<0.05).

CONCLUSIONS

The improved LV pump function that occurred with GHS treatment in this model of CHF was most likely a result of favorable effects on LV myocardial remodeling and contractile processes. On the basis of these results, further studies are warranted to determine the potential role of GH secretagogues in the treatment of CHF.