Capsule endoscopy and enteroscopy: modern modalities to investigate the small bowel in paediatrics

Historically the small bowel has been considered a technically difficult area to examine because of its length (3-5 metres), location and tortuosity. Capsule endoscopy and enteroscopy have revolutionised the investigation pathway of the small bowel in adults. They are now developing increasingly important roles as modalities of investigation in paediatrics. This review appraises the current literature to define the clinical indications and practical aspects of capsule endoscopy and enteroscopy that are of interest to the clinician.     

Circulating Vascular Progenitor Cells in Patients With Type 1 Diabetes and Microalbuminuria

OBJECTIVE

Patients with type 1 diabetes and microalbuminuria are at increased risk of cardiovascular disease (CVD). Abnormalities in vascular progenitor cells, which participate in vascular repair, may be implicated in this susceptibility.

RESEARCH DESIGN AND METHODS

We studied the number and function of vascular progenitor cells in 22 type 1 diabetic patients with history of microalbuminuria (MA⁺) and 22 type 1 diabetic patients without history of microalbuminuria (MA⁻), of similar age, diabetes duration, glycemic control, renal function, and no history of CVD.

RESULTS

MA⁺ patients had lower circulating CD34⁺ and CD34⁺/CD133⁺ cell numbers compared with MA⁻ patients (P < 0.006). In in vitro functional assays, MA⁺ patients had a significantly lower number of colony-forming units and impaired vascular endothelial growth factor (VEGF)-A–mediated tube formation, when compared with MA⁻ patients (P < 0.01).

CONCLUSIONS

In type 1 diabetic patients with microalbuminuria, a marker of microvascular injury and a risk factor for CVD, circulating vascular progenitor cell number is reduced and function is impaired.The number of circulating endothelial progenitor cells inversely relates to cardiovascular disease (CVD) (1–3); microalbuminuria is one of the earliest manifestations of diabetic nephropathy and a marker of CVD (4). A subset of patients with type 1 diabetes is susceptible to diabetic nephropathy, a condition characterized by a higher risk of cardiovascular morbidity and mortality (4,5). Type 1 diabetic patients without complications have a lower number of circulating progenitor cells than healthy control subjects (6,7). To gain insight into the susceptibility to CVD in type 1 diabetes, we studied circulating vascular progenitor cell number and function in type 1 diabetic patients with and without microalbuminuria.     

A pulse sequence for rapid in vivo spin-locked MRI

PURPOSE: To develop a novel pulse sequence called spin-locked echo planar imaging (EPI), or (SLEPI), to perform rapid T1rho-weighted MRI. MATERIALS AND METHODS: SLEPI images were used to calculate T1rho maps in two healthy volunteers imaged on a 1.5-T Sonata Siemens MRI scanner. The head and extremity coils were used for imaging the brain and blood in the popliteal artery, respectively. RESULTS: SLEPI-measured T1rho was 83 msec and 103 msec in white (WM) and gray matter (GM), respectively, 584 msec in cerebrospinal fluid (CSF), and was similar to values obtained with the less time-efficient sequence based on a turbo spin-echo readout. T1rho was 183 msec in arterial blood at a spin-lock (SL) amplitude of 500 Hz. CONCLUSION: We demonstrate the feasibility of the SLEPI pulse sequence to perform rapid T1rho MRI. The sequence produced images of higher quality than a gradient-echo EPI sequence for the same contrast evolution times. We also discuss applications and limitations of the pulse sequence.     

3D-T1rho quantitation of patellar cartilage at 3.0T

PURPOSE: To demonstrate the feasibility of three-dimensional (3D) T(1rho)-weighted imaging of human knee joint at 3.0T without exceeding the specific absorption rate (SAR) limits and the measurement of the baseline T(1rho) values of patellar cartilage and several muscles at the knee joint. MATERIALS AND METHODS: 3D gradient-echo sequence with a self-compensating spin-lock pulse cluster of 250 Hz power was used to acquire 3D-T(1rho)-weighted images of the knee joint of five healthy subjects. Global and regional analysis of patellar cartilage T(1rho) were performed. Furthermore, T(1rho) of several periarticular muscles were analyzed. RESULTS: The global average T(1rho) value of the patellar cartilage varied from 39 to 43 msec. The regional average T(1rho) values varied from 38 to 42 msec, and from 42 to 44 msec for medial and lateral facets, respectively. In vivo reproducibility of average T(1rho) of patellar cartilage was found to be 5% (coefficient of variation). Similarly, the global average T(1rho) values for biceps femoris, lateral gastrocnemius, medial gastrocnemius, and sartorius varied between 31-46, 29-49, 35-48, and 32-50 msec, respectively. CONCLUSION: We demonstrated the feasibility of 3D-T(1rho)-weighted imaging of the knee joint at 3.0T without exceeding SAR limits.     

Prostate brachytherapy postimplant dosimetry: a comparison of suture-embedded and loose seed implants

PURPOSE: To compare postimplant dosimetry and seed embolization rates for prostate brachytherapy implants using suture-embedded and loose seeds. METHODS AND MATERIALS: Dosimetric analysis of the whole prostate, prostate quadrants, rectum, and surrogate urethra was performed on 54 loose seed and 81 RAPIDStrand (RS) patients. Seed embolization rates were determined from chest radiographs. RESULTS: Whole prostate V100 and D90 did not differ significantly for the loose seed (V100 = 90.5%, D90 =153.2 Gy) and RS groups (V100 = 91.5%, D90 = 151.6 Gy) (p = 0.43 and 0.65, respectively), but V150, V200, and contiguous V200 were higher (p < or = 0.003) for the RS group (59.9%, 28.3%, and 23.2%, respectively) than the loose seed group (52.5%, 22.8%, and 16.1%, respectively). Extraprostatic measures (conformity index and external index) were also different at the p < 0.05 level. The embolization rate was 40% in the loose seed group and 14% in the RS group. CONCLUSIONS: The most significant difference between the two study groups was a decrease in the embolization rate. Although some statistically significant changes in postimplant dosimetry were observed, they were nevertheless small.     

The neurotoxin, MPP+, induces hyperphosphorylation ofTau, in the presence of α-Synuclein, in SH-SY5Y neuroblastoma cells

Alzheimer's disease (AD) is characterized, in part, by intracellular neurofibrillary tangles composed of hyperphosphorylated filamentous aggregates of the microtubule-associated protein, Tau. Such hyperphosphorylated Tau is also found in Lewy bodies (LBs), and cytoplasmic inclusion bodies in certain forms of Parkinson's disease (PD). Further, LBs also contain aggregates of alpha-synuclein (alpha-Syn), also a microtubule-associated protein, which has been linked to the genesis of PD. To investigate a specific correlation between Tau phosphorylation and alpha-Syn, we generated a SH-SY5Y cell line that stably expresses human wild type alpha-Syn. Protein expression levels in the stably transfected cell line (SHalpha-Syn) were within the physiological range of alpha-Syn expression found in Substantia nigra. We show here, in the MPP+ (1-methyl-4-phenylpyridinium ion) cell model of parkinsonism, a time- and dose-dependent increase in the hyperphosphorylation of Tau at pSer396/404 (PHF-1-reactive Tau, p-Tau), concomitant with increased accumulation of alpha-Syn, upon treatment of cells with the neurotoxin. This increase in p-Tau was strictly dependent on the presence of alphaSyn, since in transfected cells not expressing any alpha-Syn, MPP+ failed to induce an increase in PHF-1-reactive Tau. The production of p-Tau caused increased cytotoxicity as indexed by reduced cell viability. Moreover, in the absence of alpha-Syn, the cells were more resistant to MPP+ -induced cell death. The increased levels of both p-Tau and alpha-Syn led to diminished levels of these proteins associated with the cytoskeleton, which was accompanied by enhanced presence of the proteins in the cytoskeletal-free fractions. These data indicate that alpha-Syn and p-Tau modulate the pathogenicity of one another, suggesting a novel convergent mechanism of neurodegeneration.     

Insulin-like factor 3 levels in amniotic fluid of human male fetuses

BACKGROUND: Rodent studies suggest that the peptide hormone insulin-like factor 3 (Insl3) made by the fetal testis is responsible for the first transabdominal phase of testicular descent, and may be affected by xenobiotics to disrupt male reproductive tract development. To date, there is very little information on the production of INSL3 by the human fetus during gestation. The objective of the present study was to determine the concentrations and time course during pregnancy of INSL3 and testosterone production in human fetuses and their associations with maternal characteristics, pregnancy complications and outcome. METHODS: This is a retrospective cohort study in which women who contributed amniotic fluid specimens to a bank from 2003-2006 were followed to determine their pregnancy complications and pregnancy outcome. Amniotic fluid specimens were collected from the Reproductive Genetics Laboratory of the Hospital of the University of Pennsylvania subsequent to routine amniocentesis. INSL3 and total testosterone levels were measured in amniotic fluid (from n = 50 female, n = 237 male fetuses) by validated immunoassays and correlated with maternal characteristics, pregnancy complications and outcomes. RESULTS: INSL3 was only detectable in amniotic fluid from male fetuses, and highest levels occurred from weeks 15-17 of gestation. INSL3 concentration was positively associated with increased birth weight, the occurrence of pre-eclampsia and advanced maternal age, but not with testosterone levels. CONCLUSIONS: INSL3 concentration in human amniotic fluid is potentially predictive of fetal sex and pre-eclampsia, and presumably reflects the functioning of the fetal Leydig cell population.