Archive of Medical Research

Infliximab in severe active ankylosing spondylitis with spinal ankylosis.

Background: Infliximab is an anti-tumour necrosis factor monoclonal antibody, which significantly improves pain, stiffness and functional disability outcomes in patients with active ankylosing spondylitis. There are limited data available on the efficacy of this treatment for the subgroup with established spinal ankylosis. Aim: To compare the treatment response of infliximab in active severe ankylosing spondylitis for patients with and without radiographic evidence of spinal ankylosis in the clinical practice setting. Methods: Twenty-seven patients with mean Bath Ankylosing Spondylitis Disease Activity Index of 8.7, all HLA-B27 positive, with 11 (41%) having spinal ankylosis, were studied for 54 weeks. The qualification for initial and ongoing infliximab treatment was defined by the Australian Pharmaceutical Benefit Schedule (PBS), and 5 mg/kg of infliximab was given at 0 week (baseline), repeated at 2 and 6 weeks and every 6 weeks thereafter. At each time point, PBS-mandated and international consensus response measures were completed. Disease activity and outcome measures for spinal ankylosis subgroup and those who did not have spinal ankylosis were cross-sectionally compared at baseline and 1 year. Results: Patients with spinal ankylosis tended to be older (P = 0.01). Although the subgroup with spinal ankylosis had higher baseline activity scores, the only significant difference between the subgroups was the degree of morning stiffness (P = 0.04). By 54 weeks, all patients including the subgroup with spinal ankylosis fulfilled the PBS criteria for continuation of treatment. Majority of patients including the subgroup with spinal ankylosis achieved the various international consensus response measures. Patients with spinal ankylosis also experienced significant improvements in health-related quality of life, with majority returning to full-time employment by 1 year. Conclusion: In real-life clinical practice, patients with established disease with spinal ankylosis and high levels of inflammation and disease activity can achieve a major clinical response with infliximab.

Cheung PP, Tymms KE, Wilson BJ, Shadbolt B, Brook AS, Dorai Raj AK, Khoo KB.

Department of Rheumatology, Canberra Hospital, Canberra, ACT, Australia.

The hypothalamus-pituitary-testis axis in boys during the first six months of life: a comparison of cryptorchidism and hypospadias cases with controls.

It is inconclusive whether the feedback mechanisms of the hypothalamus-pituitary-testis (HTP) axis are already established in the first 6 months of life, partly due to the dramatic changes in HPT-axis hormone levels over this period. Moreover, it is unclear whether these hormone levels are aberrant in boys with cryptorchidism or hypospadias, and therefore predictive for future fertility. We studied the regulation mechanisms of the HTP axis, and the effect of age, in boys 1-6 months of age. Secondly, we studied testicular function - as reflected by HPT hormones - in newborns with cryptorchidism or hypospadias. Sera from a population sample of infants with cryptorchidism (n = 43), hypospadias (n = 41) and controls (n = 113) were analyzed for inhibin B, anti-Müllerian hormone (AMH), testosterone, luteinizing hormone (LH), follicle stimulating hormone (FSH) and sex hormone binding globulin (SHBG). LH, testosterone, non-shbg-bound testosterone (NSBT), and AHM levels showed significant age-related trends. After age-correction, a negative correlation between FSH and inhibin B was observed (r = -0.43). The only significant group-differences were lower testosterone and NSBT levels in cryptorchidism cases, with a mean testosterone of 1.8 and 2.6 nmol/L and a mean NSBT of 0.48 and 0.70 nmol/L for cryptorchidism cases and controls, respectively. The higher levels of LH, testosterone, and NSBT in boys born pre-term or with a low birthweight indicate that abnormal prenatal development may determine postnatal testis function. Our results support the hypothesis that the inhibin B - FSH feedback loop is already functional before puberty. The lower testosterone and NSBT levels indicate that disturbed Leydig cell function can already be detected early after birth in cryptorchid boys.

Pierik FH, Deddens JA, Burdorf A, de Muinck Keizer-Schrama SM, de Jong FH, Weber RF.

Department of Andrology, Erasmus MC, Rotterdam, The Netherlands.

Rates of orchiopexies in Sweden: 1977-1991.

Cryptorchidism is a known risk factor for testicular cancer and the secular increase in testicular cancer incidence might have been paralleled by a similar increase in cryptorchidism. Data on trends in prevalence of cryptorchidism are however conflicting and decreases have recently been reported. To analyse Swedish trends in rates of orchiopexy, we used the Swedish Hospital Discharge Register to identify all cases of orchiopexy carried out for cryptorchidism between 1977 and 1991, that is, before the era of outpatient orchiopexies in Sweden. Observed trends were analysed in 5-year age groups. The estimated average annual per cent changes (EAPCs) and the years in which the EAPC significantly changed were estimated using Joinpoint Regression. Finally, we estimated the cumulative incidence of orchiopexy by birth cohort. Among boys aged less than 10, the orchiopexy rate started to decrease in the early 1980s. EAPCs were -2.88 (95% confidence interval (CI): -5.48, -0.21) among boys aged 5-9 and -6.63 among those aged 0-4 (95% CI: -8.84, -4.37). Among subjects aged at least 10, the rate decreased over the whole study period. Although the use of orchiopexy rates to measure prevalence of cryptorchidism has limitations, our findings may suggest that cryptorchidism prevalence decreased in Sweden starting from the early 1980s.

Richiardi L, Vizzini L, Nordenskjöld A, Pettersson A, Akre O.

Cancer Epidemiology Unit, CeRMS and CPO Piemonte, University of Turin, Turin, Italy.

Association between polymorphisms in the prostate-specific antigen (PSA) promoter and release of PSA.

Variations in serum prostate-specific antigen (PSA) have been ascribed to A/G nucleotide polymorphisms located at -158 bp (rs266882) and -4643 bp (rs925013), relative to the transcription start site within the promoter of the PSA gene. PSA is also an androgen receptor target (AR) gene and polymorphisms in AR gene are known to affect AR function. Our objective was to compare the impact of these A/G polymorphisms separately or in combination with AR CAG micro satellite on regulation of PSA secretion into seminal plasma and blood in young men. Leukocyte DNA was extracted from 291 conscripts and genotyping performed with the Sequenom Mass Array System. PSA was measured with an immunofluorometric assay. Linear regression analysis was used to test the association of polymorphism frequencies with serum and seminal plasma levels of PSA. PSA gene polymorphisms at -158 bp or -4643 bp did not alone influence total PSA (tPSA) levels in seminal plasma or in blood. Homozygotes for the A-allele at -158 bp in combination with CAG > 22 had significantly higher serum levels of tPSA than subjects carrying the G-allele (p = 0.01). In conclusion, the PSA gene polymorphisms did not importantly influence the levels of tPSA in seminal plasma or in blood. tPSA in serum was influenced by interactions between PSA promoter variants and AR CAG polymorphism.

Sävblom C, Giwercman A, Malm J, Halldén C, Lundin K, Lilja H, Giwercman Y.

Department of Laboratory Medicine, Division of Clinical Chemistry, Lund University, Malmö University Hospital, Malmö, Sweden.

Particle loading rates for HVAC filters, heat exchangers, and ducts.

The rate at which airborne particulate matter deposits onto heating, ventilation, and air-conditioning (HVAC) components is important from both indoor air quality (IAQ) and energy perspectives. This modeling study predicts size-resolved particle mass loading rates for residential and commercial filters, heat exchangers (i.e. coils), and supply and return ducts. A parametric analysis evaluated the impact of different outdoor particle distributions, indoor emission sources, HVAC airflows, filtration efficiencies, coils, and duct system complexities. The median predicted residential and commercial loading rates were 2.97 and 130 g/m(2) month for the filter loading rates, 0.756 and 4.35 g/m(2) month for the coil loading rates, 0.0051 and 1.00 g/month for the supply duct loading rates, and 0.262 g/month for the commercial return duct loading rates. Loading rates are more dependent on outdoor particle distributions, indoor sources, HVAC operation strategy, and filtration than other considered parameters. The results presented herein, once validated, can be used to estimate filter changing and coil cleaning schedules, energy implications of filter and coil loading, and IAQ impacts associated with deposited particles. Practical Implications The results in this paper suggest important factors that lead to particle deposition on HVAC components in residential and commercial buildings. This knowledge informs the development and comparison of control strategies to limit particle deposition. The predicted mass loading rates allow for the assessment of pressure drop and indoor air quality consequences that result from particle mass loading onto HVAC system components.

Waring MS, Siegel JA.

The University of Texas at Austin, Department of Civil, Architectural, and Environmental Engineering, Austin, TX, USA.

How free of tobacco smoke are \’smoke-free\’ homes?

The risks of exposure to environmental tobacco smoke (ETS) are well established and \’harm reduction\’ strategies such as smoking outside to protect infants and children from exposure to ETS have been advocated for some time. The aim of this study was to assess the validity of self-reported smoking levels in residential settings. The participants were families (n = 92) randomly selected from lower socioeconomic areas of Perth, Western Australia. Each household was monitored for vapor phase nicotine and particulates with an aerodynamic diameter of </=10 mum (PM(10)). Of the 42% (39) households who reported that someone smoked cigarettes at home, only four (4%) said that smoking occurred inside the house. There was a \’moderate\’ agreement between parental-reported tobacco smoking and levels of nicotine (kappa = 0.55, P < 0.01). There were significant differences in the median levels of air nicotine (P < 0.01) and PM(10) (P < 0.05) between households in which smoking was reported as only occurring outside, and the smoke-free households. Practical Implications The study outcome suggests that a strategy based on the separation of children and smoking activity is inadequate to protect the former from ETS at home, and that health professionals should give parents unambiguous advice to give up smoking in order to make their homes a completely smoke-free environment.

Rumchev K, Jamrozik K, Stick S, Spickett J.

School of Public Health, Curtin University of Technology, Perth, WA, Australia.

Serum FLT-3 ligand in a busulphan-induced model of chronic bone marrow hypoplasia in the female CD-1 mouse.

The concentration of the cytokine fms-like tyrosine kinase-3 ligand (FL) is elevated in the plasma of patients treated with chemotherapy or radiotherapy for malignant conditions. In addition, plasma FL is increased in patients with bone marrow failure resulting from stem-cell defects (e.g. aplastic anaemia). Our goal in the present study was to measure the concentration of serum FL in mice treated with the chemotherapeutic agent busulphan (BU) to induce bone marrow depression and relate changes in FL to effects on haemopoiesis. Female CD-1 mice were treated with BU (9.0 mg/kg) or vehicle by intraperitoneal injection on 10 occasions over 21 days. Animals were autopsied on days 1, 23, 72, 119 and 177 postdosing. A full blood count was performed, and serum prepared for FL analysis. Femoral marrow cell suspensions were prepared to assess the total femoral nucleated cell count (FNCC) and the number of committed haemopoietic progenitor cells (CFU-C). On days 1 and 23 postdosing, significant decreases were evident in many peripheral blood parameters; the FNCC and CFU-C were also reduced in BU-treated mice, in conjunction with increases in serum FL levels. On days 72, 119 and 177 postdosing, several peripheral blood and bone marrow parameters remained reduced and the concentration of serum FL continued to be significantly increased. Linear regression analysis demonstrated significant correlations between the concentration of serum FL in BU-treated mice and peripheral blood and bone marrow parameters; this suggests the possible use of serum FL as a potential biomarker for drug-induced bone marrow injury.

Molyneux G, Gibson FM, Whayman M, Turton JA.

Division of Cellular and Molecular Medicine, Section for Cellular and Molecular Pathology, St. George\’s, University of London, London, UK. gemma.molyneux@icr.ac.uk

The haemotoxicity of azathioprine in repeat dose studies in the female CD-1 mouse.

Azathioprine (AZA) is a cytotoxic immunosuppressive drug used in the prevention of rejection in organ transplants and the treatment of auto-immune diseases. However, AZA is haemotoxic causing significant bone marrow depression. The present studies were to characterize the haemotoxicity of AZA in the female CD-1 mouse. In Experiment 1, a dose-ranging study, with AZA gavaged daily for 10 days, clinical evidence of toxicity was evident at 125 mg/kg and above. Experiment 2 was a dose-response study with AZA gavaged daily for 10 days at 40-120 mg/kg. At day 1 after the final dose, AZA induced a dose-related pancytopaenia, reduced femoral marrow cellularity, increases in serum levels of the cytokine fms-like tyrosine kinase 3 ligand, reduction in granulocyte-monocyte colony-forming units and erythroid colonies, and increased bone marrow apoptosis. Histology demonstrated hepatocyte hypertrophy, thymic atrophy, reduced splenic extramedullary haemopoiesis, and reduced cellularity of sternal bone marrow. In Experiment 3, AZA was dosed for 10 days at 100 mg/kg with autopsies at 1, 3, 9, 22, 29, 43 and 57 days postdosing. At 1, 3 and 9 days, haematological parameters reflected changes in Experiment 2. At 22/29 days, many blood parameters were returning towards normal; at 43/57 days, most parameters compared with controls. However, there was some evidence of a persistent (i.e. residual/late-stage) mild reduction in RBC and erythroid progenitor cell counts at day 43/57. We conclude that the CD-1 mouse provides an acceptable model for the haemotoxicity of AZA in man.

Molyneux G, Gibson FM, Chen CM, Marway HK, McKeag S, Mifsud CV, Pilling AM, Whayman MJ, Turton JA.

Division of Cellular and Molecular Medicine, Section for Cellular and Molecular Pathology, St. George\’s, University of London, London,UK.

Dysregulation of matrix metalloproteinases and their tissue inhibitors is related to abnormality of left ventricular geometry and function in streptozotocin-induced diabetic minipigs.

This study aimed to characterize matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) in relation to changes in left ventricle (LV) geometry and function in a porcine model with streptozotocin (STZ)-induced diabetes. In 15 Chinese Guizhou minipigs with STZ-induced diabetes (diabetic group) and 15 age-matched normal controls (control group), Doppler tissue imaging was performed at 6 months of diabetes. Serum MMP-2, -9, TIMP-1, -4 and B-type natriuretic peptide (BNP) were determined. Expression of MMPs, TIMPs, urokinase type-plasminogen activator (uPA), its receptor (uPAR) and plasminogen activator inhibitor-1 (PAI-1) in aortic intima and LV myocardium was evaluated, with gelatinolytic activities of tissue MMP-2, -9 accessed by zymography. Left ventricle end-diastolic septum thickness (P < 0.05) and mass (P < 0.05) were increased, whereas peak systolic mitral annulus velocity (Sm, P < 0.001), LV systolic (P = 0.01) and diastolic strain (P < 0.001) were significantly decreased in diabetic group than in controls. Diabetic group showed higher expression of TIMP-1, -4 in aortic intima and LV myocardium (P < 0.01 or P < 0.05), with increased collagen content and elevated serum BNP level (P = 0.004) and lower gelatinolytic activities of tissue MMP-2, -9 (all P < 0.05). Semi-quantitative RT-PCR of those diabetic tissues revealed elevated mRNA levels of major TIMPs, uPA, uPAR and PAI-1. Reduction of serum MMP-2 and -9 levels was observed in diabetic group vs. control group (both P < 0.05). This study features elevated levels of TIMP-1, -4, uPA, uPAR and PAI-1, and decreased activities of MMP-2, -9 in aorta and myocardium in STZ-induced diabetic minipigs, indicating that MMP-TIMP dysregulation is associated with LV hypertrophy, cardiac dysfunction and increased cardiovascular fibrosis in diabetes.

Lu L, Zhang Q, Pu LJ, Peng WH, Yan XX, Wang LJ, Chen QJ, Zhu ZB, Michel JB, Shen WF.

Department of Cardiology, Rui Jin Hospital, Jiaotong University School of Medicine, Shanghai, China.

Enhanced proliferation of aortal smooth muscle cells treated by 1,25(OH)2D3 in vitro coincides with impaired formation of elastic fibres.

Elastin is the major extracellular matrix component synthesized, secreted and deposited by vascular smooth muscle cells (SMCs) in the arterial media and thus plays an important role in vascular homeostasis. Results of our previous studies showed that 1alpha,25-dihydroxycholecalciferol [1,25(OH)(2)D(3)-calcitriol] accelerates proliferation of SMCs and modulates their growth in vitro. The aim of this study was to find ultrastructural support for the idea that 1,25(OH)(2)D(3)-calcitriol affects elastic fibre formation due to accelerated proliferation of aortal SMCs in vitro. SMCs exposed 10 days to supraphysiological concentration (10 nM) of calcitriol in primary culture were examined by fluorescence and transmission electron microscopy. Morphological studies revealed that calcitriol altered elastin maturation by favouring accumulation of immature rather than fully processed elastic fibres. A substantial decrease in the amorphous elastin deposition and abnormal accumulation of microfibrillar component, in thickened multilayer culture, were observed. These studies suggest that 1,25(OH)(2)D(3) affect formation of elastic fibres due to enhanced proliferation of SMCs in culture.

Tukaj C.

Department of Electron Microscopy, Medical University of Gdańsk, Gdańsk, Debinki, Poland. ctukaj@amg.gda.pl