Carbohydrate nutrition, glycemic index, and the 10-y incidence of cataract

BACKGROUND: Although dietary carbohydrates are thought to play a role in cataractogenesis, few epidemiologic studies have examined links between carbohydrate nutrition and cataract. OBJECTIVES: We investigated the associations between dietary glycemic index (GI), glycemic load (GL), total carbohydrate intake, and 10-y incident nuclear, cortical, and posterior subcapsular cataract. DESIGN: Of 3654 baseline participants in an Australian population aged >/=49 y (1992-1994), 933 were seen after 5 and/or 10 y, had completed a detailed semiquantitative food-frequency questionnaire, had no previous cataract surgery or baseline cataract, and had photographs taken to assess incident cataract with the Wisconsin Cataract Grading System. Dietary information was collected with a validated food questionnaire. GI was calculated from a customized database of Australian foods. GI, GL, and all other nutrients were energy adjusted. Hazard ratios (HRs) and 95% CIs were calculated with the use of discrete logistic models. RESULTS: After age, sex, diabetes, and other factors were controlled for, each SD increase in GI significantly predicted incident cortical cataract (HR: 1.19; 95% CI: 1.01, 1.39). Participants within the highest compared with the lowest quartile of GI were more likely to develop incident cortical cataract (HR: 1.77; 95% CI: 1.13, 2.78; P for trend = 0.035). These findings were similar after excluding participants with diabetes, although they were slightly attenuated and marginally nonsignificant (HR: 1.16; 95% CI: 0.98, 1.37, per SD increase in GI). No association was found between GI and nuclear or posterior subcapsular cataract and between GL or carbohydrate quantity and any cataract subtype. CONCLUSION: In an Australian cohort, poorer dietary carbohydrate quality, reflected by high GI, predicted incident cortical cataract.     

Updates for the radiologist in non-muscle-invasive,muscle-invasive,and metastatic bladder cancer

Urothelial bladder cancer is a common malignancy requiring a multidisciplinary approach to treatment. Significant recent advances have been made in terms of the genetic and molecular characterization of bladder cancer subtypes, and novel treatment approaches are being investigated and approved. Given the important role of imaging in the diagnosis, staging, and follow-up of this disease, it is necessary for radiologists to remain up-to-date in terms of nomenclature and standards of care. In this review, recent developments in bladder cancer characterization and treatment will be discussed, with reference to the contributions of imaging in non-muscle-invasive, muscle-invasive, and metastatic settings.

     

Prognostic significance of supradiaphragmatic lymph nodes at initial presentation in patients with stage III high-grade serous ovarian cancer

Abdominal Radiology - To identify the optimal size threshold and to assess the prognostic significance of supradiaphragmatic lymph nodes at initial presentation of patients with high-grade serous...     

Endocytosis is required for exocytosis and priming of respiratory burst activity in human neutrophils

Objective and design

Neutrophil generation of reactive oxygen species (ROS) is enhanced by exposure to pro-inflammatory agents in a process termed priming. Priming is depending on exocytosis of neutrophil granules and p47^phox phosphorylation-dependent translocation of cytosolic NADPH oxidase components. Clathrin-mediated endocytosis was recently reported to be necessary for priming, but the mechanism linking endocytosis to priming was not identified. The present study examined the hypothesis that endocytosis regulates neutrophil priming by controlling granule exocytosis.

Materials and methods

Clathrin-mediated endocytosis by isolated human neutrophils was inhibited by chlorpromazine, monodansylcadaverine, and sucrose. Exocytosis of granule subsets was measured as release of granule components by ELISA or chemiluminescence. ROS generation was measured as extracellular release of superoxide as reduction of ferrocytochrome c. p38 MAPK activation and p47^phox phosphorylation were measured by immunoblot analysis. Statistical analysis was performed using a one-way ANOVA with the Tukey–Kramer multiple-comparison test.

Results

Inhibition of endocytosis prevented priming of superoxide release by TNFα and inhibited TNFα stimulation and priming of exocytosis of all four granule subsets. Inhibition of endocytosis did not reduce TNFα-stimulated p38 MAPK activation or p47^phox phosphorylation. Inhibition of NADPH oxidase activity blocked TNFα stimulation of secretory vesicle and gelatinase granule exocytosis.

Conclusions

Endocytosis is linked to priming of respiratory burst activity through ROS-mediated control of granule exocytosis.

     

Paradoxical structural effects in the unilaterally denervated spontaneously hypertensive rat kidney

OBJECTIVE: To determine the effects of chronic denervation on renal vascular structure and function in young adult spontaneously hypertensive rats (SHRs). DESIGN: Unilateral renal denervation (SHRUDx) or sham-operation (SHRS) was performed in SHRs at 6 weeks of age. At 10 weeks, rats were allocated to one of three procedures designed to examine renal vascular structure and function. A further group underwent bilateral renal denervation. METHODS: In SHRUDx or SHRS groups, either the kidneys were perfusion-fixed for stereological estimates of artery wall and lumen dimensions or for vascular casting to determine arteriole lumen diameters, or the rats were anaesthetized for estimation of glomerular capillary pressure. RESULTS: Chronic unilateral renal denervation had no significant effect on the development of hypertension between 6 and 10 weeks of age, as previously reported, but resulted in luminal narrowing of the interlobular artery (denervated group 52 +/- 2 mum, sham-operated group 64 +/- 1 mum; P < 0.01 for interaction between strain and treatment), without alterations in interlobular or arcuate artery wall dimensions. There were no significant effects on either afferent or efferent arteriole lumen diameters. Estimated glomerular capillary pressure was significantly lower in the denervated kidneys of SHRUDx (47 +/- 1 mmHg) compared with kidneys of the SHRS (50 +/- 1 mmHg; P < 0.04). Mean arterial pressure was approximately 12 mmHg lower in the bilaterally denervated SHRs than in the sham-operated SHRs. CONCLUSIONS: Although bilateral denervation attenuated the development of hypertension in SHRs, unilateral denervation did not, indicating that one neurally intact kidney was sufficient to drive the normal development of SHR hypertension, but only with apparent prohypertensive compensatory changes in the denervated kidney.     

Prophylactic antibiotics for simple hand lacerations: Time for a clinical trial?

BackgroundSimple hand lacerations (not involving bones, tendons, nerves, or vessels) are a common emergency department (ED) complaint. Whilst the practices of irrigation, debridement, foreign body removal, and suture repair are well accepted, the use of prophylactic antibiotics is not. Without evidenced-based guidelines, practice is left to physician preference.ObjectivesThe aim of this study was to assess the need for, and the feasibility to perform, a randomised controlled trial to evaluate the role of prophylactic antibiotics in simple hand lacerations.MethodsThe study was done in three phases: (1) estimation of the national ED burden of simple hand lacerations and the use of antibiotic prophylaxis; (2) assessment of indications for antibiotic prophylaxis and (3) investigation of patient willingness to enrol in a randomised controlled trial and their preferred outcomes from simple hand lacerations. For Phase 1, we analysed the 2007 National Hospital Ambulatory Medical Care Survey. For Phase 2, we surveyed ED physicians in three urban teaching institutions (two in Brooklyn, NY and one in Washington, DC). For Phase 3, we surveyed ED patients at the same three institutions.ResultsPhase 1: out of 116.8 million ED visits nationally in 2007, 1.8 million (1.6%) were due to simple hand lacerations, of which 1.3 million (71%) required repair. Of those repaired, 27% (95% CI, 19–35%) were prescribed prophylactic antibiotics, most commonly cephalexin (73%). Phase 2: out of 108 providers surveyed, 69 (64%) responded. 16% (95% CI, 9–27%) reported prescribing prophylactic antibiotics routinely, most commonly cephalexin (84%, 95% CI, 67–93%). The degree of contamination was the most important factor (91%, 95% CI, 82–96%) in the physicians’ decision to prescribe antibiotics. Phase 3: of the 490 patients surveyed, 64% (95% CI, 60–68%) expressed interest in participating in a study to evaluate the use of prophylactic antibiotics. Their primary concern was prevention of infection (77%, 95% CI, 73–81%).ConclusionSimple hand lacerations represent a substantial number of ED visits in the United States. Absence of clear guidelines, disparity in physician practice, and patient interest in infection prevention all support performing a prospective randomised controlled trial to establish the role of antibiotic prophylaxis in simple hand lacerations.