Residential exposure to magnetic fields: an empirical examination of alternative measurement strategies

OBJECTIVES: To investigate the impact of measuring a single home then imputing information from another home among subjects who lived in two homes in a subset of the National Cancer Institute/Children's Cancer Group (NCI/CCG) investigation of residential exposure to magnetic fields and risk of childhood leukaemia. METHODS: Each subject's summary time weighted average (TWA) exposure was derived from measurements of two homes, weighted by the fraction of the reference period lived in the residence. The three cost efficient field work strategies examined were measuring: (a) the longer lived in home; (b) the currently lived in home; and (c) the former lived in home. Two different methods were used for imputing the missing values: (a) control mean imputation, (b) status specific mean imputation. The subject's summary exposure to magnetic fields estimated with each approach was compared with the subject's TWA calculated from measurements in both homes. The association between estimated exposure to magnetic fields and the risk of leukaemia under different approaches was examined with unconditional logistic regression analysis. RESULTS: The Pearson correlation coefficient between the two measurements within subjects was 0.31 (p < 10(-4), indicating a lack of independence of measurements. Differences were found between mean exposures in current and former homes of cases, and between longer and shorter lived in homes of controls. All methods with measurements from one of the homes in conjunction with imputation of measurements for the second home led to marked attenuation of risk estimates at the highest exposure category, particularly when measurements from current homes were used and those from former homes were imputed. CONCLUSION: Results argue against attempting to estimate lifetime magnetic field exposure from imputed values derived from current residences to fill in gaps caused by unmeasured residences previously lived in.     

Current status of magnetic resonance imaging (MRI) and ultrasonography fusion software platforms for guidance of prostate biopsies

Prostate MRI is currently the best diagnostic imaging method for detecting PCa. Magnetic resonance imaging (MRI)/ultrasonography (US) fusion allows the sensitivity and specificity of MRI to be combined with the real‐time capabilities of transrectal ultrasonography (TRUS). Multiple approaches and techniques exist for MRI/US fusion and include direct ‘in bore’ MRI biopsies, cognitive fusion, and MRI/US fusion via software‐based image coregistration platforms.     

Effect of peritonitis on gallbladder smooth muscle contractility in guinea pigs

BACKGROUND: The mechanisms involved in the impaired gallbladder contractile response in peritonitis are unknown. The aim of this study was to determine the effect of peritonitis on the contraction and relaxation responses to different agonists in gallbladder smooth muscle in guinea pig. MATERIALS AND METHODS: Peritonitis was induced by cecal ligation and puncture (CLP) in 10 guinea pigs. Another group of 10 guinea pigs underwent a sham operation and acted as controls. Twenty-four hours after the operation, the guinea pigs were killed, and gallbladder strips were placed in organ bath. The contraction responses to KCl, carbachol, and histamine, and relaxation responses to cyclooxygenase inhibitors (indomethacin, nimesulide, and DFU) on KCl-induced contractions were recorded. RESULTS: There was no significant difference between the contractile responsiveness to KCl, but maximum contractile responses (E(max)) to carbachol and histamine were significantly reduced. Indomethacin, nimesulide, and DFU concentration dependently inhibited on KCl-induced contractions of gallbladder smooth muscle. E(max) values of indomethacin, nimesulide, and DFU were significantly reduced in the peritonitis group compared with controls (P < 0.05). The inhibitor effects of nimesulide and DFU were considerably similar, but inhibitor effect of indomethacin was significantly less than that measured for nimesulide and DFU in both control and peritonitis groups (P < 0.05). CONCLUSIONS: The contraction responses to carbachol and histamine and relaxation responses to COX inhibitors on gallbladder smooth muscle are significantly decreased by peritonitis. Although the mechanism of the decrease in contraction and relaxation responses in CLP-induced peritonitis is completely unknown, we speculate that impaired smooth muscle responses may be related to an alteration in the regulation of receptor/postreceptor excitation-response coupling and/or through changes on Ca(2+) influx.     

Use of canonical variate analysis biplot in examination of choline content data of some foods

Adequate intake (AI) of choline as part of the daily diet can help prevent major diseases. Low choline intake is a major risk factor for liver and several neurological disorders. Extreme choline consumption may cause diseases such as hypotension, sweating, diarrhea, and fishy body odor. The AI of choline is 425 mg/day for adult women; higher for pregnant and lactating women. The AI for adult men is 550 mg/day. The total choline content of foods is calculated as the sum of free choline, glycerophosphocholine, phosphocholine, phosphatidylcholine and sphingomyelin. These are called the choline variables. Observed values of choline variables may be different in amounts of nutrients. So different food groups in terms of choline variables are useful to compare. The present paper shows the advantages of using canonical variate analysis biplot to optimally separate groups and explore the differentiality of choline variables amounts in foods.     

[18F]Fluciclatide in the in vivo evaluation of human melanoma and renal tumors expressing αvβ3 and αvβ5 integrins

Purpose

[¹⁸F]Fluciclatide is an integrin-targeted PET radiopharmaceutical. α_vβ₃ and α_vβ₅ are upregulated in tumor angiogenesis as well as on some tumor cell surfaces. Our aim was to use [¹⁸F]fluciclatide (formerly known as [¹⁸F]AH111585) for PET imaging of angiogenesis in melanoma and renal tumors and compare with tumor integrin expression.

Methods

Eighteen evaluable patients with solid tumors ≥2.0 cm underwent [¹⁸F]fluciclatide PET/CT. All patients underwent surgery and tumor tissue samples were obtained. Immunohistochemical (IHC) staining with mouse monoclonal antibodies and diaminobenzidine (DAB) was applied to snap-frozen tumor specimens, and additional IHC was done on formalin-fixed paraffin-embedded samples. DAB optical density (OD) data from digitized whole-tissue sections were compared with PET SUV_{80% max}, and Patlak influx rate constant (K _i) data, tumor by tumor.

Results

Tumors from all 18 patients demonstrated measurable [¹⁸F]fluciclatide uptake. At the final dynamic time-point (55 min after injection), renal malignancies (in 11 patients) demonstrated an average SUV_{80% max} of 6.4?±?2.0 (range 3.8 – 10.0), while the average SUV_{80% max} for metastatic melanoma lesions (in 6 patients) was 3.0?±?2.0 (range 0.7 – 6.5). There was a statistically significant difference in [¹⁸F]fluciclatide uptake between chromophobe and nonchromophobe renal cell carcinoma (RCCs, with SUV_{80% max} of 8.2?±?1.8 and 5.4?±?1.4 (P?=?0.020) and tumor-to-normal kidney (T/N) ratios of 1.5?±?0.4 and 0.9?±?0.2, respectively (P?=?0.029). The highest Pearson's correlation coefficients were obtained when comparing Patlak K _i and α_vβ₅ OD when segregating the patient population between melanoma and RCC (r?=?0.83 for K _i vs. melanoma and r?=?0.91 for K _i vs. RCC). SUV_{80% max} showed a moderate correlation with α_vβ₅ and α_vβ₃ OD.

Conclusion

[¹⁸F]Fluciclatide PET imaging was well tolerated and demonstrated favorable characteristics for imaging α_vβ₃ and α_vβ₅ expression in melanoma and RCC. Higher uptake was observed in chromophobe than in nonchromophobe RCC. [¹⁸F]Fluciclatide may be a useful radiotracer to improve knowledge of integrin expression.     

Effect of Intraoperative Paracetamol on Catheter-Related Bladder Discomfort: A Prospective,Randomized, Double-Blind Study

Background

The insertion of urinary catheters during urinary surgical interventions may lead to catheter-related bladder discomfort (CRBD) in the postoperative period.

Objective

We aimed to evaluate the effect of single-dose intravenous paracetamol on CRBD.

Methods

In this randomized, controlled, double-blind study, 64 patients (age >18 years, American Society of Anesthesiologists Physical Status I–II) requiring urinary bladder catheterization for percutaneous nephrolithotomy were assigned to groups that received either intravenous paracetamol (15 mg/kg) (group P) or NaCl 0.9% solution (control group [group C]) 30 minutes before the end of surgery. Patients received patient-controlled analgesia (10-mg bolus of meperidine, without infusion, 20-minute lock out) postoperatively. CRBD and pain status were assessed at 30 minutes and 1, 2, 4, 6, and 12 hours postoperatively. Postoperative meperidine requirement and patient and surgeon satisfaction were assessed.

Results

Group P had significantly lower CRBD scores at all time points except at 12 hours postoperatively compared with group C (P < 0.05). Total meperidine consumption was significantly higher in group C (P < 0.05). Patient and surgeon satisfaction scores were significantly higher in group P (P < 0.05).

Conclusions

Intraoperative single-dose paracetamol was found to be effective in reducing the severity of CRBD and pain in urologic surgery. We suggest that it may be an efficient, reliable, easy-to-apply drug for CRBD. ClinicalTrials.gov identifier: NCT01652183.Key words: catheter-related bladder discomfort, intravenous paracetamol, urologic surgery