Percutaneous transluminal angioplasty in the region of the aortic bifurcation. The two-balloon technique with results and long-term follow-up study

Percutaneous transluminal angioplasty of lesions located at the bifurcation of vessels, especially the aortic bifurcation, has been considered contraindicated because of possible occlusion or embolization of the contralateral vessel. With the evolution of angioplasty techniques and the development of new balloon catheters, these lesions can now be successfully treated with the kissing balloon technique. This technique was used to dilate 61 atherosclerotic vascular lesions in 32 patients with vascular insufficiency. The procedure was successful in 58 atherosclerotic stenoses in 30 patients. Because of the high blood flow and large size of these vessels, beneficial clinical results can be anticipated following successful dilatation. Follow-up study, extending for as long as 53 months, suggests the durability of the procedure and that the kissing balloon technique should be considered as a viable alternative to surgery in dilatable lesions of the aortic bifurcation.     

Rapid and sustained hematopoietic recovery in lethally irradiated mice transplanted with purified Thy-1.1lo Lin-Sca-1+ hematopoietic stem cells

Hematopoietic stem cells (HSCs) are believed to play a critical role in the sustained repopulation of all blood cells after bone marrow transplantation (BMT). However, understanding the role of HSCs versus other hematopoietic cells in the quantitative reconstitution of various blood cell types has awaited methods to isolate HSCs. A candidate population of mouse HSCs, Thy-1.1lo Lin-Sca-1+ cells, was isolated several years ago and, recently, this population has been shown to be the only population of BM cells that contains HSCs in C57BL/Ka-Thy-1.1 mice. As few as 100 of these cells can radioprotect 95% to 100% of irradiated mice, resulting long-term multilineage reconstitution. In this study, we examined the reconstitution potential of irradiated mice transplanted with purified Thy-1.1lo Lin-Sca-1+ BM cells. Donor-derived peripheral blood (PB) white blood cells were detected as early as day 9 or 10 when 100 to 1,000 Thy-1.1lo Lin-Sca-1+ cells were used, with minor dose-dependent differences. The reappearance of platelets by day 14 and thereafter was also seen at all HSC doses (100 to 1,000 cells), with a slight dose-dependence. All studied HSC doses also allowed RBC levels to recover, although at the 100 cell dose a delay in hematocrit recovery was observed at day 14. When irradiated mice were transplanted with 500 Thy-1.1lo Lin-Sca-1+ cells compared with 1 x 10(6) BM cells (the equivalent amount of cells that contain 500 Thy-1.1lo Lin-Sca-1+ cells as well as progenitor and mature cells), very little difference in the kinetics of recovery of PB, white blood cells, platelets, and hematocrit was observed. Surprisingly, even when 200 Thy1.1lo Lin-Sca- 1+ cells were mixed with 4 x 10(5) Sca-1- BM cells in a competitive repopulation assay, most of the early (days 11 and 14) PB myeloid cells were derived from the HSC genotype, indicating the superiority of the Thy-1.1lo Lin-Sca-1+ cells over Sca-1- cells even in the early phases of myeloid reconstitution. Within the Thy-1.1lo Lin-Sca-1+ population, the Rhodamine 123 (Rh123)hi subset dominates in PB myeloid reconstitution at 10 to 14 days, only to be overtaken by the Rh123lo subset at 3 weeks and thereafter. These findings indicate that HSCs can account for the early phase of hematopoietic recovery, as well as sustained hematopoiesis, and raise questions about the role of non-HSC BM populations in the setting of BMT.     

Effects of androgen deprivation on chronic bacterial prostatitis in a rat model

BACKGROUND: Many attempts have been made to improve the treatment success rate of chronic bacterial prostatitis (CBP). However, no treatment modality has achieved complete cure. The growth and development of the prostate is under direct hormonal control, and it is possible that prostatitis may be directly influenced by its hormonal milieu in a similar fashion to benign prostatic hyperplasia and prostate cancer. Therefore, the effects of androgen deprivation on the treatment of CBP were investigated in rats. METHODS: Experimental CBP was induced in one hundred, male Wistar rats by instillation of bacterial suspension (Escherichia coli Z17, O2: K1: H-) containing 1 x 10(8) CFU/ microL into the prostatic urethra. Microbiologically and histologically proven CBP was demonstrated in 62% (62 of 100) of the rats after 4 weeks of bacterial instillation. The 62 rats demonstrating CBP were randomly divided into five groups: control; castration; finasteride; estrogen; and levofloxacin groups. All drug treatments were conducted over a period of 4 weeks. RESULTS: Microbiological cultures and histological findings of the prostate and urine samples demonstrated reduced bacterial growth and improved inflammatory responses in all four experimental groups compared with the control group. The castration and estrogen groups showed coherent trends of decrease in bacterial growth and improvements in prostatic inflammation compared with the control group, but not to a statistically significant degree (P > 0.05). However, the finasteride and levofloxacin groups did show statistically significant decreases in bacterial growth and improvements in prostatic inflammation compared with the control group (P < 0.05). CONCLUSION: These results suggest that androgen deprivation is an effective modality in CBP treatment. In particular, the finasteride treatment reduced the severity of CBP in the animal model without reducing the systemic testosterone level. The combination of finasteride and levofloxacin maybe one of the effective treatment modalities for CBP.     

Hematopoietic stem cells are not direct cytotoxic targets of natural killer cells

Bone marrow (BM) transplants from one individual to an irradiated histoincompatible individual of the same species are rejected. In mice, the primary host barrier cells that recognize bone marrow grafts bearing hematopoietic histocompatibility antigens bear surface markers of natural killer (NK) lymphocytes. Because of the innate ability of NK cells to kill susceptible targets, it has been proposed that the cytotoxic bone marrow graft rejection. To test this hypothesis, we purified hematopoietic stem cells from mice and incubated them with purified populations of actively cytotoxic allogeneic and semisyngeneic NK cells, followed by analysis of the ability of the treated hematopoietic stem cells (HSCs) to rescue lethally irradiated syngeneic animals. Such rescue was unimpaired. Also, HSC allografts were transplanted into transgenic mice deficient in NK and killer T-cell cytotoxicity generated by expressing diphtheria toxin A chain under the control of granzyme A promoter. Allogeneic HSCs were susceptible to allogeneic restriction in these mice, implying that the effector functions of NK marker-positive cells do not require NK cell cytotoxicity.     

Adenosine Induced Torsades de Pointes in a Child with Congenital Long QT Syndrome

Torsades de pointes is a rare arrhythmia characterized by its bradycardia dependence and increased adrenergic discharge, whether it occurs as a congenital anomaly or as an acquired problem resuiting from drug intoxication or other conditions. There are no reliable tests to assess the propensity toward torsades de pointes or evaluate the efficacy of treatment in these patients. Adenosine can result in marked slowing of sinus and ventricular rate and leads to increased sympathic discharge when given intravenously. We induced torsades de pointes in a child with congenital long QT syndrome (Jervell-Lange-Nielsen syndrome) using 200 μg/kg IV adenosine bolus. Higher dosage of adenosine (600 μg/kg) did not lead to torsades de pointes after β blockade. Adenosine may induce torsades de pointes in patients with the long QT syndrome and may be used as a test to reproduce the clinical arrhythmia. Whether adenosine proves to be useful for assessing the efficacy of treatment will require extensive investigation in larger series of patients.     

Prolonged effect of a novel S-nitrosated glyco-amino acid in endothelium-denuded rat femoral arteries: potential as a slow release nitric oxide donor drug

1. The vasodilator properties of a novel S-nitrosated glyco-amino acid (RIG200) were investigated in isolated rat femoral arteries and compared with those of the parent S-nitrosothiol compound, S-nitroso-N-acetylpenicillamine (SNAP).
2. Spectrophotometric analysis revealed that 2.5 mM solutions of RIG200 decomposed more slowly (half-life (t_1/2)=216.2±26.7 min) than SNAP (t_1/2=37.2±13.8 min) in Krebs buffer at 24°C. Furthermore, the rate of decomposition of SNAP, but not of RIG200, was significantly reduced by the Cu(I) chelator, neocuproine. We concluded that the relative stability of RIG200 is due, at least in part, to its resistance to trace Cu(I)-catalyzed decomposition. Nitric oxide (NO) generation from SNAP and RIG200 was confirmed by use of an NO electrode.
3. Experiments to investigate the vasodilator effects of RIG200 were carried out on isolated femoral arteries taken from adult male Wistar rats (400–550 g). Lengths of artery (7–8 mm long) were cannulated, dissected free and perfused at constant flow rate (0.6 ml min⁻¹) with Krebs buffer. Vessels were precontracted with phenylephrine (10.2±0.3 μM) and developed pressures of 91.8 ± 4 mmHg, detected upstream by a differential pressure transducer.
4. Concentration-dependent vasodilator responses to bolus injections of SNAP or RIG200 (10 μl; 10⁻⁸–10⁻³ M) made into the perfusate of endothelium-intact vessels were transient, recovering the pre-injection pressure in <20 min.
5. Responses to equivalent bolus injections of SNAP in endothelium-denuded vessels were also transient but those in response to concentrations of RIG200 >10⁻⁵ M were sustained. Responses to 10⁻³ M RIG200 were sustained for periods >4 h. Sustained vasodilatation was reversed by the NO scavenger, ferrohaemoglobin (10 μM) but was unaffected by the NO synthase inhibitor, N^ω-nitro-L-arginine methyl ester (200 μM), indicating involvement of NO from a source other than NO synthase.
6. We suggest that a possible explanation for the prolonged effect of RIG200 is retention of the compound by the vascular wall, facilitated by endothelial denudation. Slow decomposition of RIG200 in situ would release sufficient NO to maintain a ‘vasodilator tone'' which persists for more than 4 h. Selective retention by damaged vessels could have important therapeutic implications with regard to targeted delivery of NO, restoring protection to areas deprived of endogenous NO, whilst avoiding unwanted hypotension.

     

Lower face lifting and contouring with a novel internal real-time thermosensing monopolar radiofrequency

As demand for a youthful appearance has increased, various techniques for face lifting and contouring have been used to reduce excess fat deposition and improve skin laxity. Recently, radiofrequency (RF)-assisted lipolysis and liposuction (RFAL) has been introduced for body and face contouring. This study aimed to evaluate the clinical improvement and safety of a new RFAL device for face lifting and contouring. A prospective study was conducted in 20 Korean patients who underwent an internal real-time thermosensing monopolar RFAL procedure. Prior to treatment and 12 and 24 weeks after treatment, digital photographs were taken, and the degree of improvement as measured by investigators and patients was recorded. Skin elasticity was measured using a Cutometer (CT575, Courage and Khazaka®, Cologne, Germany). Safety profiles were also evaluated at each visit. Results showed favorable improvement in skin laxity and fat deposition. Both investigators’ evaluations and patients’ evaluation showed significant improvement between 12 and 24 weeks. Although the changes in skin elasticity measured by the Cutometer were not statistically significant, all three treated regions showed a trend toward improvement. No major side effects such as infection or burn were observed. The internal, real-time thermosensing monopolar RFAL device showed clinical efficacy and safety. After further studies with more patients and longer follow-up periods, internal real-time thermosensing monopolar RF devices might become one of the popular treatment options for face lifting and contouring.     

Proton chemical shift imaging: an evaluation of its clinical potential using an in vivo fatty liver model

The potential laboratory and clinical utility of proton chemical shift imaging (PCSI) was evaluated by studying fatty liver change in rats, which offered a simple animal model for tissue lipid buildup. There was excellent correlation between lipid group signal intensities from in vivo PCSI studies and liver triglyceride levels obtained from in vitro measurements (R = 0.97). The in vivo T1 relaxation time measurements in fatty liver tissue demonstrated two distinct populations of nonexchanging protons. We explain the reason for the lack of sensitivity in conventional magnetic resonance (MR) imaging studies of fatty liver change and discuss the implications of our findings for MR imaging studies of other tissues. PCSI promises improved diagnostic sensitivity and specificity in studying a wide range of human pathologic conditions.