Hyaluronic acid/CD44H interaction induces cell detachment and stimulates migration and invasion of human glioma cells in vitro

The mechanisms underlying the invasive properties of glio-mas, the major form of intrinsic brain tumours in humans, are poorly understood. We have reported that CD44 plays an important role in this behaviour in vitro. In the present work, we investigated the role of its ligand, hyaluronic acid (HA), in invasion in 8 human glioma cell lines. We found that HA mediates cell detachment via its interaction with its high affinity receptor, CD44H. Using 8 μm porosity polycarbonate filter transwells, we demonstrate that HA strongly stimulates migration in all 8 cell lines. This effect was found to be partially counteracted by a CD44H monoclonal antibody (MAb), suggesting the involvement of CD44H, as well as other HA receptors, in this process. Furthermore, incorporation of increasing concentrations of HA in Matrigel in an in vitro invasion assay resulted in a substantial increase in the invasive propensity of the glioma cell lines. Moreover, blocking experiments with the CD44H MAb suggest that CD44H and other receptors interact with HA to promote cell invasion in vitro. Our results show that HA induces cell detachment, stimulates migration and promotes invasion via its interaction with CD44H and other HA receptors in vrtro. These effects could be prevented by use of specific HA receptor antibodies.     

Bladder perforation in a peritoneal dialysis patient

The dysfunction of the catheter in peritoneal dialysis (PD) is a frequent complication. However, perforation of organs are rare, particularly that of the urinary bladder. This requires an early diagnosis and prompt treatment of patients. We report here the case of a 38-year-old woman having end-stage renal disease due to autosomal-dominant polycystic kidney disease treated by PD since November 2000. Three years later, she was treated for Staphylococcal peritonitis. Four months later, she presented with a severe urge to urinate at the time of the fluid exchanges. The biochemical analysis of the fluid from the bladder showed that it was dialysis fluid. Injection of contrast through the catheter demonstrated the presence of a fistula between the bladder and the peritoneal cavity. She underwent cystoscopic closure of the fistulous tract and the PD catheter was removed. Subsequently, the patient was treated by hemodialysis. One month later, a second catheter was implanted surgically after confirming the closure of the fistula. Ten days later, she presented with pain at the catheter site and along the tunnel, which was found to be swollen along its track. The injection of contrast produced swelling of the subcutaneous tunnel but without extravasation of the dye. PD was withdrawn and the patient was put back on hemodialysis. Bladder fistula is a rare complication in PD and diagnosis should be suspected when patient complains of an urge to pass urine during the exchanges, which can be confirmed by contrast study showing presence of dye in the bladder. PD may be possible after the closure of the fistula, but recurrence may occur.     

Gangliosides modulate proliferation,migration, and invasiveness of human brain tumor cells in vitro

Gliomas, the most common form of intrinsic brain tumor, are characterized by diffuse local invasion of the normal brain structures, irrespective of their histological grade of malignancy; a feature that is a major obstacle to successful therapy. They generally infiltrate the central nervous system (CNS) as individual tumor cells several centimeters beyond the macroscopic tumor margin and consequently often recur, after subtotal surgical resection. Factors involved in the control of both their proliferation and invasiveness are poorly documented. In this work, the role of gangliosides on proliferation of both human fetal human brain cells and five cell lines derived from human gliomas with different grades of malignancy was investigated. In addition, 8 μm-porosity polycarbonate filters were used to study cell motility. In addition, these filters were coated with the reconstituted extracellular matrix (ECM) composite, Matrigel, to assess invasiveness. The results presented show that gangliosides generally exert a proliferation inhibitory effect on fetal brain cells and glioma cell lines in vitro and play an important role in promoting glioma cell motility and invasiveness. The molecular mechanisms involved in the action of gangliosides may prove useful in identifying new targets for an anti-invasion therapy.     

Natural evolution of massive vitreous hemorrhage in diabetic retinopathy

A study of 131 eyes with massive vitreous hemorrhage of diabetic origin showed that 3 months after the hemorrhage visual acuity had improved in 34 eyes (25.9%), was unchanged in 82 (62.6%), and had worsened in 15 (11.4%). The number of eyes improving between 3 and 6 months post-hemorrhage was the same as the number whose visual acuity worsened, 19 (14.5%). After 6 months, the proportion of worsening eyes was much greater than that of improving eyes, so that 2 years post-hemorrhage, 48.8% of the 86 eyes remaining in the study had visual acuity of below hand-movements standard, and 29.1% visual acuity better than hand-movements standard, as against respectively 22.1% and 38.2% of the original 131 eyes 6 months post-hemorrhage.