Effects of hyaluronan and SPARC on fibroproliferative events assessed in an in vitro bladder acellular matrix model

Bladder acellular matrix (BAM) is a promising candidate for urinary biomaterials development. In the current work we have modified the BAM construct to include two biologically active components; hyaluronan (HA) and a peptide (SP4.2) derived from secreted protein, acidic, rich in cysteine (SPARC), a matricellular glycoprotein. In order to assess the potential of an HA/SP4.2 modified BAM to influence cellular functions associated with bladder healing, experiments were conducted to evaluate the individual and combined effects of these molecules on in vitro fibroproliferative endpoints within a co-culture model. Thiol-modified HA (246 kDa, 15 mg/ml)+/-SP4.2 (200 microm) was incorporated and cross-linked into BAM disks through disulfide bond formation. The following scaffolds compositions were then evaluated in a bladder smooth muscle cell (SMC)-urothelial (UEC) cell co-culture model: BAM unmodified; BAM+HA, BAM+SP4.2 (media addition); BAM+HA+SP4.2 (media addition); BAM+HA+SP4.2 (matrix incorporated). At 3, 7 and 14 days post-seeding, SMC-mediated matrix contraction and gelatinolytic activity were evaluated. HA-modified BAM exhibited a significantly higher degree of contraction and gelatinase activity compared to unmodified BAM. In contrast, addition of SP4.2 to BAM produced a negligible effect on contraction, while significantly reducing gelatinase activity. Matrices containing both molecules displayed significant increases in contraction, while gelatinase activity was dependent upon the method of peptide delivery. These results demonstrate that both HA and SP4.2 have significant, yet distinct effects on the contractile and proteolytic activity of bladder SMCs and suggest that a modified BAM may be capable of modulating processes associated with post-surgical graft contracture and scar formation.     

Bone mineral density is not reduced in HIV-infected Caucasian men treated with highly active antiretroviral therapy

OBJECTIVE: Recent studies have reported low bone mineral density (BMD) in patients infected with human immunodeficiency virus (HIV). Frequently these findings have been attributed to treatment with highly active antiretroviral therapy (HAART). We sought to determine whether BMD in HIV-infected men treated with HAART for at least 3 months is different from that in healthy controls, and, if so, what HIV-related factors might explain this finding. DESIGN: Cross-sectional analysis. PATIENTS: Fifty-nine HIV-infected Caucasian men treated with HAART, and 118 healthy community-dwelling controls. Each HIV-infected man was age-matched (within 5 years) to two controls. MEASUREMENTS: All participants had measurements of BMD and bone-related laboratory parameters. RESULTS: The mean duration of known HIV infection was 8.5 years, and of treatment with HAART was 52 months. There was no significant difference in mean BMD between groups at the lumbar spine (HIV group: 1.23 g/cm2, controls: 1.25 g/cm2; P = 0.53) or total body (HIV group: 1.18 g/cm2, controls: 1.20 g/cm2; P = 0.09). At the total hip the HIV-infected group had significantly lower BMD than the control group (HIV group: 1.03 g/cm2, controls: 1.09 g/cm2; P = 0.01). The HIV-infected group were, on average, 6.3 kg lighter than the controls. After adjusting for this weight difference, HIV infection was not an independent predictor of BMD at any site (lumbar spine P = 0.79; total hip P = 0.18; total body P = 0.76). CONCLUSIONS: HIV-infected men treated with HAART are lighter than healthy controls. This weight difference is responsible for a small decrement in hip BMD. Overall, BMD is not significantly reduced in HIV-infected Caucasian men treated with HAART.     

Magnetic resonance spectroscopy detects biochemical changes in the brain associated with chronic low back pain: a preliminary report

Magnetic resonance (MR) spectroscopy is a noninvasive technique that can be used to detect and measure the concentration of metabolites and neurotransmitters in the brain and other organs. We used in vivo (1)H MR spectroscopy in subjects with low back pain compared with control subjects to detect alterations in biochemistry in three brain regions associated with pain processing. A pattern recognition approach was used to determine whether it was possible to discriminate accurately subjects with low back pain from control subjects based on MR spectroscopy. MR spectra were obtained from the prefrontal cortex, anterior cingulate cortex, and thalamus of 32 subjects with low back pain and 33 control subjects without pain. Spectra were analyzed and compared between groups using a pattern recognition method (Statistical Classification Strategy). Using this approach, it was possible to discriminate between subjects with low back pain and control subjects with accuracies of 100%, 99%, and 97% using spectra obtained from the anterior cingulate cortex, thalamus, and prefrontal cortex, respectively. These results demonstrate that MR spectroscopy, in combination with an appropriate pattern recognition approach, is able to detect brain biochemical changes associated with chronic pain with a high degree of accuracy.     

The management of haemorrhagic cystitis with sodium pentosan polysulphate

OBJECTIVE: To assess the use of sodium pentosan polysulphate (SPP) for haemorrhagic cystitis (HC), a potentially life-threatening side-effect in patients treated with pelvic radiotherapy or cyclophosphamide, and which can be difficult to manage as patients often have significant comorbidity. PATIENTS AND METHODS: Between September 1991 and December 2000, 60 consecutive patients (24 women and 36 men) with haemorrhagic cystitis were primarily treated with SPP; 53 patients had had radical radiotherapy for pelvic malignancy and seven systemic cyclophosphamide. All patients were screened for blood dyscrasia and residual/primary urothelial malignancy with imaging, urine cytology and cystoscopy. RESULTS: In all, 51 patients were available for follow-up; the median (range) interval between completing treatment and developing haematuria was 4.5 (0.08-39.4) years, the duration of treatment 180 (21-1745) days and patients were followed for 450 (19-4526) days from the onset of haematuria. All patients were started on SPP at an initial dose of 100 mg three times daily. In 21 patients the dose was gradually reduced to a maintenance dose of 100 mg and in 10 further patients SPP was stopped because the haematuria stopped completely. Twenty patients died while on treatment from causes not directly related to their haematuria. CONCLUSION: We recommend the use of SPP as the primary method of managing haemorrhagic cystitis associated with pelvic radiotherapy or systemic chemotherapy.     

Suppression of aromatase activity in vitro by PCBs 28 and 105 and Aroclor 1221

The effects of polychlorinated biphenyls (PCBs) on human cytochrome P450 aromatase activity in vitro were investigated using a commercially available microsomal fraction obtained from baculovirus infected insects that had been transfected with the human CYP19 gene and cytochrome P450 reductase. The assay measured the conversion of tritiated testosterone to estradiol in Tris buffer at pH 7.4. When aroclors, commercial preparations of PCBs, were added to aromatase assays at a 10 microM concentration, Aroclor 1221 caused a reduction in the aromatase activity, whereas other aroclors (1016, 1232, 1242, 1248, 1254, 1260, 5432, 5442 and 5460) were without effect. Further investigation of the effect of Aroclor 1221 on aromatase activity showed that the inhibition was dose dependent. When a reconstituted mixture (RM) of PCBs that represented the congeneric content of human milk was investigated, no inhibition of aromatase activity at the maximum treatment of 15.0 microM was observed. None of the congeners present in the reconstituted mixture, except PCB 28 and 105, affected P450 arom activity. PCB 28 showed a statistically significant inhibition of aromatase activity (P<0.05) at 1.5 and 15 microM and a significant inhibition of aromatase activity by PCB 105 was also observed, but only at 15 microM. In three separate kinetic analyses the Km(app) for aromatase was 64, 89 and 69 nM (mean 74 nM). In addition, PCB 28 resulted in an increase in the Km(app) without a significant effect on Vmax(app), suggesting competitive inhibition by this congener. This conclusion was supported by slope (Km(app)/Vmax(app) versus [inhibitor]) and intercept (1/Vmax(app) versus [inhibitor]) replots. The slope replots gave Ki(app) values for PCB 28 of 0.9, 1.3 and 2.0 microM (mean 1.4 microM), whereas intercept replots were almost horizontal. Thus, PCB 28 is a competitive inhibitor of aromatase with a Ki(app) value approximately 20-fold the Km(app) value. Based on these studies, we conclude that most PCBs are not inhibitors of aromatase activity in vitro. However, as being inhibitors of aromatase activity, Aroclor 1221, PCB 28 and PCB 105 would remain a priority for further study as possible endocrine disrupters.