Graft Distortion After Endovascular Repair of Abdominal Aortic Aneurysm: Association with Sac Morphology and Mid-Term Complications

Purpose: To investigate the incidence, significance, and mechanism of stent-graft distortion after endovascular repair (EVR) of abdominal aortic aneurysm. Methods: EVR of abdominal aortic aneurysm was performed in 51 cases (49 modular, bifurcated; 2 tube). Thirty-two patients were followed for 6 or more months and had equivalent baseline and follow-up images which could be used to determine changes in graft configuration. Sac dimensions were measured using computed tomographic (CT) images and graft-related complications were recorded. Results: Amongst 32 patients evaluated on follow-up, there was graft distortion in 24. Distorted grafts were significantly (p= 0.002) associated with sac diameter reduction (mean 5 mm) and sac length reduction (mean 8.1 mm). All graft-related complications occurred in the limbs of eight distorted grafts, with a mean reduction of sac length in this group of 7.8 mm on reformatted CT images. Conclusion: There was a highly significant association between graft distortion and limb complications, and reduced sac dimensions.     

Mammary Involution and Breast Cancer Risk: Transgenic Models and Clinical Studies

Postlactational involution is the process following weaning during which the mammary gland undergoes massive cell death and tissue remodeling as it returns to the pre-pregnant state. Lobular involution is the process by which the breast epithelial tissue is gradually lost with aging of the mammary gland. While postlactational involution and lobular involution are distinct processes, recent studies have indicated that both are related to breast cancer development. Experiments using a variety of rodent models, as well as observations in human populations, suggest that deregulation of postlactational involution may act to facilitate tumor formation. By contrast, new human studies show that completion of lobular involution protects against subsequent breast cancer incidence.     

Routine intraoperative stenting for renal transplant recipients

BACKGROUND: Major urological complications (MUCs) after kidney transplantation contribute to patient morbidity and compromise graft function. Ureteric stents have been successfully used to treat such complications and a number of centers have adopted a policy of universal prophylactic stenting, at the time of graft implantation, to reduce the incidence of urine leaks and ureteric stenosis. METHODS: In conjunction with the Cochrane Renal Group we searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, reference lists of articles, books and abstracts and contacted companies, authors and experts to identify randomized controlled trials examining the use of stents in renal transplantation. The primary outcome was the incidence of MUCs and data on this statistic was pooled and analyzed using a random effects model. RESULTS: Seven randomized controlled trials (1154 patients) of low or moderate quality were identified. The incidence of MUCs was significantly reduced (relative risk [RR] 0.24; 95% CI: 0.07 - 0.77; P=0.02; number needed to treat = 13) by prophylactic ureteric stenting. Urinary tract infections were more common in stented patients (RR 1.49), unless the patients were prescribed 480 mg cotrimoxazole once daily. With this antibiotic regime the incidence of infection was equivalent between the two groups (RR 0.97). Stents appeared generally well tolerated, although trials using longer stents (> or = 20 cm) for longer periods of time (>6 weeks) reported more problems with encrustation and migration. CONCLUSIONS: Universal prophylactic stenting reduces the incidence of MUCs and should be recommended on the basis of currently available randomized controlled trials.     

A One-Stop Clinic for Men with Testicular Anxiety

INTRODUCTION

Testicular lumps and orchialgia both cause considerable anxiety, usually related to concerns about possible cancer.

PATIENTS AND METHODS

We established a rapid-access testicular clinic staffed by a urologist and a specialist ultrasonographer in order to delay the time to a definitive diagnosis.

RESULTS

Over a 30-month period, 845 men underwent clinical examination and scrotal ultrasonography. Overall, 4% of men were found to have testicular cancer. The majority of men were found to have normal testes or minor abnormalities and could be re-assured.

CONCLUSIONS

This one-stop clinic reduces the time to a definitive diagnosis which may reduce anxiety suffered by men with testicular complaints and allows rapid identification of those harbouring a testicular malignancy.     

The growth hormone-insulin like growth factor axis revisited: lessons from IGF-1 and IGF-1 receptor gene targeting

We have created a liver-specific igf1 gene-deletion mouse model (LID) with markedly reduced circulating IGF-I levels. They demonstrate that while they have normal growth and development they develop insulin resistance secondary to the elevation of circulating growth hormone. When mated with an acid-labile subunit (ALS) gene-deleted mouse they also show osteopenia suggesting that circulating IGF-I levels play a significant role in bone formation. In a separate transgenic mouse we created a model of severe insulin resistance and type 2 diabetes by the overexpression of a dominant-negative IGF-I receptor in skeletal muscle. In this model we show that lipotoxicity plays a major role in the progression of the disease and is affected by treatment with a fibrate, which reverses the insulin resistance and diabetic state. These models are therefore very useful in studying human physiology and disease states.This work was presented in part at the IPNA Seventh Symposium on Growth and Development in Children with Chronic Kidney Disease: The Molecular Basis of Skeletal Growth, 1–3 April 2004, Heidelberg, Germany     

HIV Facial Lipoatrophy: Causes and Treatment Options

Background. Human immunodeficiency virus (HIV)-associated facial lipoatrophy is becoming epidemic and may seriously affect quality of life.
Objective. To review the possible causes and treatment options for HIV facial lipoatrophy.
Methods. This article is based on a review of the medical literature and the author's clinical experience in treating HIV facial lipoatrophy.
Conclusion. Although absorbable injectable fillers and implants are helpful in treating HIV facial lipoatrophy, they are limited by cost and the short duration of correction. Newer forms of longer-lasting fillers (poly-l-lactic acid [Sculptra]) and permanent injectable fillers (liquid injectable silicone) are proving useful for treatment of this condition.     

Minimal Incision Surgery as a Risk Factor for Early Failure of Total Knee Arthroplasty

A consecutive series of revision total knee arthroplasty (TKA) performed at 3 centers by 5 surgeons for a 3-year period was reviewed. Revisions performed for infection and rerevisions were excluded. Review of clinical and radiographic data determined incision type, sex, age, time to revision, and primary diagnosis at time of revision. Two-hundred thirty-seven first-time revision TKAs were performed, of which 44 (18.6%) had been a minimal incision surgery (MIS) primary TKA and 193 (81.4%) had been a standard primary TKA. Patients with MIS were younger (62.1 vs 66.2 years, P = .02). Most striking was the difference in time to revision, which was significantly shorter for the MIS group (14.8 vs 80 months, P < .001). Minimal incision surgery TKA accounted for a substantial percentage of revision TKA in recent years at these centers. The high prevalence of MIS failures occurring within 24 months is disturbing and warrants further investigation.     

Imaging P-glycoprotein function in rats using [11C]-N-desmethyl-loperamide

Objective

One mechanism that may be responsible for drug resistance in epilepsy is the upregulation of P-glycoprotein (P-gp), a drug efflux pump, at the epileptogenic focus. In this study, we sought to evaluate the potential of a recently developed P-gp PET radiotracer, [¹¹C]N-desmethyl-loperamide ([¹¹C]dLop), for measuring P-gp function in the rat brain.

Methods

The precursor to [¹¹C]dLop was synthesized in two steps from commercially available starting materials and subsequently radiolabeled in one step using [¹¹C]methyl iodide. [¹¹C]dLop was then administered to two groups of rats, controls (n = 4) and those treated with a P-gp inhibitor (n = 8). Cyclosporin A (CsA, 50 mg/kg, n = 3) and tariquidar (TQ, 20 mg/kg, n = 5) were both used as P-gp inhibitors. MicroPET brain scans were performed for 120 min with arterial blood sampling. A one-tissue compartment model was used to estimate the distribution volume of radiotracer as the outcome measure of P-gp function.

Results

Plasma levels of parent [¹¹C]dLop decreased rapidly to <0.1 mean standardized uptake value (SUV) at 60 min. In controls, brain uptake of [¹¹C]dLop was very low (<0.1 mean SUV). In contrast, the mean SUVs were significantly higher in rats treated with CsA (0.51) or TQ (0.22). Estimation of distribution volumes was stable by 70 min. Estimated distribution volumes were significantly larger after P-gp inhibition (CsA = 7.3, TQ = 4.7) compared to controls (no inhibitor = 2.1).

Conclusions

The rat brain demonstrates significantly increased uptake of [¹¹C]dLop after P-gp inhibition. [¹¹C]dLop is a substrate of P-gp, and will serve as a promising radiotracer for studying P-gp function in the future.     

Peroxisome proliferator-activated receptor-alpha agonist treatment in a transgenic model of type 2 diabetes reverses the lipotoxic state and improves glucose homeostasis

Abnormalities in insulin action are the characteristics of type 2 diabetes. Dominant-negative muscle-specific IGF-I receptor (MKR) mice exhibit elevated lipid levels at an early age and eventually develop type 2 diabetes. To evaluate the role of elevated lipids in the progression of the diabetic state, MKR mice were treated with WY14,643, a peroxisome proliferator-activated receptor (PPAR)-alpha agonist. WY14,643 treatment markedly reduced serum fatty acid and triglyceride levels within a few days, as well as muscle triglyceride levels, and subsequently normalized glucose and insulin levels in MKR mice. Hyperinsulinemic-euglycemic clamp analysis showed that WY14,643 treatment enhanced muscle and adipose tissue glucose uptake by improving whole-body insulin sensitivity. Insulin suppression of endogenous glucose production by the liver of MKR mice was also improved. The expression of genes involved in fatty acid oxidation was increased in liver and skeletal muscle, whereas gene expression levels of hepatic gluconeogenic enzymes were decreased in WY14,643-treated MKR mice. WY14,643 treatment also improved the pattern of glucose-stimulated insulin secretion from the perfused pancreata of MKR mice and reduced the beta-cell mass. Taken together, these findings suggest that the reduction in circulating or intracellular lipids by activation of PPAR-alpha improved insulin sensitivity and the diabetic condition of MKR mice.     

Low-iodine diet revisited: importance in nuclear medicine imaging and management

PURPOSE: The need for a low-iodine diet (LID) to maximize the results of radioactive iodine uptake (RAIU), nuclear medicine thyroid scintigraphy, and ultimately treatment of thyroid cancer patients is widely accepted. Failure to follow the prescribed diet can alter RAIU results, thyroid scan findings, and poststudy management. OBJECTIVE: Provided is a case presentation that illustrates the need for adequate patient understanding and compliance with the LID. METHODS: We present the clinical history, laboratory values, and pertinent imaging of a 21-year-old woman with papillary thyroid cancer. The patient's post-thyroidectomy I-123 and 2 subsequent thyroid (I-123 and post-RAI ablation I-131) scintigraphy examinations are reviewed as well as the patient's urine iodine levels. RESULTS: In this case of a woman with papillary thyroid cancer, the nuclear medicine whole body and neck pinhole images revealed that compliance to an LID positively impacts the overall management. After an LID was followed, the patient's urine iodine level appropriately declined from the previously elevated level. Initial negative results on thyroid scintigraphy caused by noncompliance with the LID became positive when the patient adhered to the prescribed dietary regimen. CONCLUSION: An LID is an integral element in the management of differentiated thyroid cancer. Proper guidance and emphasis on the implementation of the diet needs to be provided to patients. Noncompliance may lead to false negative imaging results, misleading the medical professionals and patient. Potentially inadequate management of the patient's thyroid cancer may follow.