Histological Analysis of a Long Term Patent Subintimal Canal in the Superficial Femoral Artery.

INTRODUCTION: Subintimal angioplasty (SIA) was introduced in the late 1980s and is a supplement to bypass surgery. Adaptation of the technique has been hampered by high rates of early intervention to maintain patency, but the long term assisted patency is good. REPORT: The superficial femoral and popliteal artery containing a patent subintimal canal were explanted from a patient who died in the authors' ward. Histological analysis indicated that the lumen was created in the medial layer of the vessel wall. A collagen rich neointima and fragmented internal elastic lamina were observed, presumably as a result of activated smooth muscle cells. The luminal surface was partly covered by a single layer of CD31, von Willebrand factor, and partly CD144 positive cells. An early atherosclerotic lesion was observed distally in the subintimal canal. DISCUSSION: Remodelling and neo-cellularisation of the vascular wall after SIA are described. Notably, hallmarks of early and late stage atherosclerotic disease were evident throughout the subintimal canal. These observations require confirmation in a larger number of specimens but underscore the need for surveillance after SIA.

Impact of a tertiary Gleason pattern 4 or 5 on clinical failure and mortality after radical prostatectomy for clinically localised prostate cancer.

UNLABELLED: Study Type - Prognosis (case series) Level of Evidence 4 What's known on the subject? and What does the study add? It is known that a tertiary Gleason grade pattern 4 or 5 found in RP specimens has a negative impact on recurrence rate regarding biochemical relapse after radical prostatectomy. This is the first publication addressing clinical outcome in patients with a tertiary Gleason grade pattern 4 or 5 showing a negative influence on clinical failure rates. OBJECTIVE: To investigate the impact of a tertiary Gleason grade (TGG) pattern 4 or 5 on clinical failure, as the presence of a TGG pattern 4 or 5 in radical prostatectomy (RP) specimens has been associated with biochemical failure. PATIENTS AND METHODS: In all, 151 consecutive patients undergoing RP between 1985 and 2006 were reviewed, and 148 patients met study inclusion criteria. The RP specimens were pathologically re-examined and the presence of a TGG pattern 4 or 5 was recorded. The endpoint was clinical failure defined as local recurrence and/or development of metastasis at a mean follow-up of 108 months. Univariate analyses were performed using the Kaplan-Meier method. Multivariate analyses were performed using Cox proportional hazards regression. RESULTS: Clinical failure was more likely among men with presence of a TGG pattern 4 or 5 than in men without a TGG pattern 4 or 5 (P= 0.006). In the subgroup of patients with Gleason score 7 the presence of a TGG 5 was significantly associated with clinical failure rate (P= 0.002). In patients with Gleason score <7 or >7, a TGG pattern 4 or 5 was not associated with increased failure rates. Multivariate Cox regression analyses in patients with Gleason score 7 showed that a TGG pattern 5 was a statistically significant predictor of clinical failure when adjusting for pathological stage, surgical margin status, extraprostatic extension and seminal vesicle invasion (hazard ratio 4.03, 95% confidence interval 1.72-9.46; P= 0.001). Further subgroup analyses showed that a TGG pattern 5 was associated with statistically higher clinical progression rates in patients with Gleason score 3 + 4 (P= 0.03). In patients with Gleason score 4 + 3, a TGG pattern 5 was associated with a trend towards a higher clinical progression rate, although this was not statistically significant (P= 0.189). CONCLUSION: A TGG pattern 4 or 5 is associated with decreased clinical recurrence-free survival in Gleason score 7.

Sustained reversal of diabetes following islet transplantation to striated musculature in the rat.

BACKGROUND: There is an increasing emphasis in the islet transplant community on the development of alternative sites for islet implantation. Striated musculature constitutes a potential alternative, which has been successfully employed in autotransplantation of parathyroid glands for decades. In the present study, a technique for intramuscular islet transplantation was developed and compared with intraportal islet transplantation in a syngeneic rat model. MATERIALS AND METHODS: Lewis rats were used. Pancreata were digested using Liberase. Islets were either transplanted into m. biceps femoris in a pearls-on-a-string fashion or intraportally, and the ability to reverse diabetes was compared. Eight weeks after transplantation an IVGTT was performed. Real-time quantitative RT-PCR was employed on muscle biopsies to investigate mRNA levels of cytokines in response to the transplant procedure. Explanted livers, muscles, and pancreata were harvested at the end of the experiment for histopathological analyses. RESULTS: 2000 IEQ repeatedly cured diabetic rats at the intraportal site, while 4000 IEQ was required at the intramuscular site. Time to reversal of diabetes, post-transplant weight development, and IVGTT curves did not differ between the groups. Normoglycemia was sustainable to the end of the study (>100 days) for all animals. The transplant procedure upregulated pro-inflammatory cytokines (IL-6 and IL-8) in striated muscle, and peri-islet fibrosis was observed in intramuscular grafts. CONCLUSIONS: Islet transplantation into striated musculature is feasible; however, in its present form the intramuscular site is less efficient compared with the liver in rats. The intramuscular site allows manipulation of the graft and implantation site prior to transplantation and may therefore have implications for islet transplantation in humans.

Glucocorticoids reduce pro-inflammatory cytokines and tissue factor in vitro and improve function of transplanted human islets in vivo.

Factors that upregulate the inflammatory status of islets probably contribute to detrimental processes leading to islet loss and impaired post-transplant function. Glucocorticoids have the potential to counteract inflammation and thus improve islet quality and function. However, glucocorticoids have diabetogenic properties and are known to hamper islet function in vivo. We examined the effect of glucocorticoids on human islets in vitro and in vivo after 48 h of exposure to different concentrations of methylprednisolone. Protein and/or mRNA levels of insulin, interleukin (IL)-8, macrophage chemoattractant protein (MCP)-1, tissue factor (TF), and IL-10 were assessed by enzyme immunosorbent assay and real time quantitative reverse transcription-polymerase chain reaction. Viability was assessed with fluorescein diacetate-propidium iodide staining, adenosine triphosphate (ATP) content and caspase activity. Six-hundred islet equivalents (IEQ) were transplanted to severe combined immunodeficiency disease mice and graft function assessed by glucose measurements and intraperitoneal glucose tolerance tests. Glucocorticoids reduce mRNA and protein levels of TF, MCP-1 and IL-8, and enhance ATP content. Insulin secretion was initially inhibited; however, after 7 days in culture, it was superior to controls. Islets exposed to methylprednisolone cured diabetic mice more effectively than control islets. In conclusion, glucocorticoids have potent anti-inflammatory properties on human islets without permanent effects on insulin metabolism. Brief glucocorticoid exposure improves function of transplanted human islets in vivo.