Radiofrequency-enhanced vascular gene transduction and expression for intravascular MR imaging-guided therapy: feasibility study in pigs

PURPOSE: To evaluate the feasibility of radiofrequency (RF)-enhanced vascular gene transduction and expression by using a magnetic resonance (MR) imaging-heating guidewire as an intravascular heating vehicle during MR imaging-guided therapy. MATERIALS AND METHODS: The institutional committee for animal care and use approved the experimental protocol. The study included in vitro evaluation of the use of RF energy to enhance gene transduction and expression in vascular cells, as well as in vivo validation of the feasibility of intravascular MR imaging-guided RF-enhanced vascular gene transduction and expression in pig arteries. For in vitro experiments, approximately 10(4) vascular smooth muscle cells were seeded in each of four chambers of a cell culture plate. Next, 1 mL of a green fluorescent protein gene (gfp)-bearing lentivirus was added to each chamber. Chamber 4 was heated at approximately 41 degrees C for 15 minutes by using an MR imaging-heating guidewire connected to a custom RF generator. At day 6 after transduction, the four chambers were examined and compared at confocal microscopy to determine the efficiency of gfp transduction and expression. For the in vivo experiments, a lentivirus vector bearing a therapeutic gene, vascular endothelial growth factor 165 (VEGF-165), was transferred by using a gene delivery balloon catheter in 18 femoral-iliac arteries (nine artery pairs) in domestic pigs and Yucatan pigs with atherosclerosis. During gene infusion, one femoral-iliac artery in each pig was heated to approximately 41 degrees C with RF energy transferred via the intravascular MR imaging-heating guidewire, while the contralateral artery was not heated (control condition). At day 6, the 18 arteries were harvested for quantitative Western blot analysis to compare VEGF-165 transduction and expression efficiency between RF-heated and nonheated arterial groups. RESULTS: Confocal microscopy showed gfp expression in chamber 4 that was 293% the level of expression in chamber 1 (49.6% +/- 25.8 vs 16.8% +/- 8.0). Results of Western blot analysis showed VEGF-165 expression for normal arteries in the RF-heated group that was 300% the level of expression in the nonheated group (70.4 arbitrary units [au] +/- 107.1 vs 23.5 au +/- 29.8), and, for atherosclerotic arteries in the RF-heated group, 986% the level in the nonheated group (129.2 au +/- 100.3 vs 13.1 au +/- 4.9). CONCLUSION: Simultaneous monitoring and enhancement of vascular gene delivery and expression is feasible with the MR imaging-heating guidewire.     

Anti-tuberculosis activity of some N-pentopyranosylamines

With the advent of multidrug-resistant Mycobacterium tuberculosis, new effective drugs are rapidly needed. Thirty-two derivatives of some N-pentopyranosylamines were prepared and tested under the Tuberculosis Antimicrobial Acquisition and Coordinating Facility (TAACF) program. This communication is presenting their antituberculosis activity in the primary screen.     

Macular corneal dystrophy including histologic and ultrastructural changes

PURPOSE: The study reports the results of a histological and ultrastructural examination of the corneal button, obtained during penetrating keratoplasty from patient with clinically recognized macular corneal dystrophy. MATERIAL AND METHODS: 34-year-old male patient suffering from macular corneal dystrophy (MCD) has been treated on corneal epithelium defect and photophobia since his early childhood. Visual acuity was decreased on the Snellen test chart to 0.02. Slit-lamp examination, and ultrasonographical measurement of the cornea's thickness were performed. Removed during penetrating keratoplasty corneal button was divided into two pieces. One of them was prepared in standard procedure for histological examination in the light microscopy after having been stained with hematoxylin and eosin, alcian blue and paS-method. From the other part, slides for ultrastructural examination in the transmission electron microscopy were prepared with the use of standard method. The family history from the patient was also taken, and available relatives have undergone examination in search of typical MCD symptoms. RESULTS: Slit-lamp examination findings revealed diffuse, from limbus to limbus, stromal opacification. In measurement by pachymeter cornea's thickness was reduced. In the light microscopy, in typical stained slides, delaminations within stroma and deficit of endothelial cells were observed. After being stained with alcian blue, dark blue deposits in the places of delamination became visible. By transmission electron microscopic examination, intracellular and extracellular deposits were detected in the stroma, Descemet membrane and endothelium. Distended keratocytes with enormous vacuoles containing abnormal material were found. Pedigree was typical for autosomal recessive inherited disease. CONCLUSIONS: Histological and ultrastructural diagnosis is a basis of recognition of macular corneal dystrophy. Analysis of the pedigree as well as ultrasonographical measurement of the cornea's thickness is very helpful to establish the right diagnosis.     

Photodynamic therapy of pterygium with verteporfin: a preliminary report

OBJECTIVE: To assess the efficacy and safety of treating pterygia by photodynamic therapy (PDT) with verteporfin (Visudyne). MATERIALS AND METHODS: Ten consecutive patients with primary, recurrent, or secondary pterygium, refusing excisional surgery, were treated with a 689-nm laser delivered directly onto the pterygium after verteporfin infusion. Postoperative outcome was followed clinically and photographically for a minimum of 3 months. RESULTS: Successful photothrombosis of pterygium vascularization was obtained immediately after treatment in all cases. After 1 month, revascularization of pterygia was observed in 70% of cases, and treatment was repeated after a 3-month interval. Regression or stabilization of pterygia was manifested by a scarring reaction of the corneal apex with complete or partial disappearance of vascularity. No relevant side effects were observed in our series. CONCLUSION: PDT with verteporfin is a safe procedure to arrest the growth of pterygia. It is indicated for patients with a low- or medium-grade pterygium that refuse a surgical approach; however, multiple sessions may be required.     

The monitoring of the accumulation of protoporphyrin IX in Walker tumours by subcutaneous administration of delta-aminolevulinic acid

Photodynamic therapy with protoporphyrin IX induced by delta-aminolevulinic acid (ALA) is mainly applied for the treatment of human superficial skin cancer. In this paper we present our study on photodynamic therapy (PDT) of the implanted Walker tumours using subcutaneous administration of ALA to improve the availability of ALA in the skin. We determined the accumulation and localization of protoporphyrin IX (PpIX) after subcutaneous administration of different concentrations of ALA in a physiological saline solutions, using fluorescence imaging technique. The results obtained indicate that PpIX accumulation depends on the concentration of ALA. The temporal behavior of PpIX fluorescence has shown a clear demarcation of tumoural zone depending on the post-administration time and the administrated concentration of the ALA solution. Further studies are needed to confirm these encouraging results and to define the PDT protocols using subcutaneous administration of ALA solution     

Self-assembly of a virus-mimicking nanostructure system for efficient tumor-targeted gene delivery

Molecular therapy, including gene therapy, is a promising strategy for the treatment of human disease. However, delivery of molecular therapeutics efficiently and specifically to the target tissue remains a significant challenge. A human transferrin (Tf)-targeted cationic liposome-DNA complex, Tf-lipoplex, has shown high gene transfer efficiency and efficacy with human head and neck cancer in vitro and in vivo (Xu, L., Pirollo, K.F., Tang, W.H., Rait, A., and Chang, E.H. Hum. Gene Ther. 1999;10:2941-2952). Here we explore the structure, size, formation process, and structure-function relationships of Tf-lipoplex. We have observed Tf-lipoplex to have a highly compact structure, with a relatively uniform size of 50-90 nm. This nanostructure is novel in that it resembles a virus particle with a dense core enveloped by a membrane coated with Tf molecules spiking the surface. More importantly, compared with unliganded lipoplex, Tf-lipoplex shows enhanced stability, improved in vivo gene transfer efficiency, and long-term efficacy for systemic p53 gene therapy of human prostate cancer when used in combination with conventional radiotherapy. On the basis of our observations, we propose a multistep self-assembly process and Tf-facilitated DNA cocondensation model that may provide an explanation for the resultant small size and effectiveness of our nanostructural Tf-lipoplex system.     

Comparative Dynamics of Retrograde Actin Flow and Focal Adhesions: Formation of Nascent Adhesions Triggers Transition from Fast to Slow Flow

Dynamic actin network at the leading edge of the cell is linked to the extracellular matrix through focal adhesions (FAs), and at the same time it undergoes retrograde flow with different dynamics in two distinct zones: the lamellipodium (peripheral zone of fast flow), and the lamellum (zone of slow flow located between the lamellipodium and the cell body). Cell migration involves expansion of both the lamellipodium and the lamellum, as well as formation of new FAs, but it is largely unknown how the position of the boundary between the two flow zones is defined, and how FAs and actin flow mutually influence each other. We investigated dynamic relationship between focal adhesions and the boundary between the two flow zones in spreading cells. Nascent FAs first appeared in the lamellipodium. Within seconds after the formation of new FAs, the rate of actin flow decreased locally, and the lamellipodium/lamellum boundary advanced towards the new FAs. Blocking fast actin flow with cytochalasin D resulted in rapid dissolution of nascent FAs. In the absence of FAs (spreading on poly-L-lysine-coated surfaces) retrograde flow was uniform and the velocity transition was not observed. We conclude that formation of FAs depends on actin dynamics, and in its turn, affects the dynamics of actin flow by triggering transition from fast to slow flow. Extension of the cell edge thus proceeds through a cycle of lamellipodium protrusion, formation of new FAs, advance of the lamellum, and protrusion of the lamellipodium from the new base.     

Medium-term effects of bisoprolol administration on renal hemodynamics and function in mild to moderate essential hypertension

Arterial hypertension is a significant cause of end-stage renal failure; effective treatment of hypertensive patients reduces the rate of progression of this disorder. β-Blockers, particularly nonselective agents, are associated with deterioration of renal function in patients with chronic renal failure. Previous studies on the interaction of the β₁-selective adrenergic antagonist bisoprolol with kidney function have been performed only acutely and over the short term. This study was designed to evaluate the antihypertensive efficacy and effects on renal hemodynamics and function of bisoprolol during medium-term (6 mo) treatment of patients with mild to moderate essential hypertension. After a 2-wk run-in period on placebo, 87 consecutive hypertensive patients (46 men, 41 women) according to ESH-ESC (European Society of Hypertension/European Society of Cardiology) guidelines, aged from 27 to 64 y (mean age, 50±11 y), without renal or cardiovascular disease, were enrolled and assigned to treatment with bisoprolol 5 mg once daily for 6 mo. At recruitment and at 6 mo after treatment, renal function was assessed and renal hemodynamics evaluated in all patients through radioisotope studies. The mediumterm effects of bisoprolol included a significant reduction in blood pressure and heart rate (P< .001) without significant adverse drug reactions. Moreover, bisoprolol produced no alteration in renal function or hemodynamics, or in cardiac output. Data presented here indicate that bisoprolol 5 mg given once daily to treat patients with mild to moderate essential hypertension is effective and safe for treatment and for preservation of renal performance when given on a medium-term basis.