Monte Carlo estimation of radiation doses during paediatric barium meal and cystourethrography examinations.

Organ doses are important quantities in assessing the radiation risk. In the case of children, estimation of this risk is of particular concern due to their significant radiosensitivity and the greater health detriment. The purpose of this study is to estimate the organ doses to paediatric patients undergoing barium meal and micturating cystourethrography examinations by clinical measurements and Monte Carlo simulation. In clinical measurements, dose-area products (DAPs) were assessed during examination of 50 patients undergoing barium meal and 90 patients undergoing cystourethrography examinations, separated equally within three age categories: namely newborn, 1 year and 5 years old. Monte Carlo simulation of photon transport in male and female mathematical phantoms was applied using the MCNP5 code in order to estimate the equivalent organ doses. Regarding the micturating cystourethrography examinations, the organs receiving considerable amounts of radiation doses were the urinary bladder (1.87, 2.43 and 4.7 mSv, the first, second and third value in the parentheses corresponds to neonatal, 1 year old and 5 year old patients, respectively), the large intestines (1.54, 1.8, 3.1 mSv), the small intestines (1.34, 1.56, 2.78 mSv), the stomach (1.46, 1.02, 2.01 mSv) and the gall bladder (1.46, 1.66, 2.18 mSv), depending upon the age of the child. Organs receiving considerable amounts of radiation during barium meal examinations were the stomach (9.81, 9.92, 11.5 mSv), the gall bladder (3.05, 5.74, 7.15 mSv), the rib bones (9.82, 10.1, 11.1 mSv) and the pancreas (5.8, 5.93, 6.65 mSv), depending upon the age of the child. DAPs to organ/effective doses conversion factors were derived for each age and examination in order to be compared with other studies.

Accuracy of magnetic resonance imaging for diagnosis and preoperative assessment of deeply infiltrating endometriosis.

OBJECTIVE: To evaluate the accuracy of preoperative magnetic resonance imaging (MRI) findings relative to surgical presence of deeply infiltrating endometriosis (DIE). METHODS: This prospective study included 92 women with clinical suspicion of DIE. The MR images were compared with laparoscopy and pathology findings. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MRI for diagnosis of DIE were assessed. RESULTS: DIE was confirmed at histopathology in 77 of the 92 patients (83.7%). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MRI to diagnose DIE at each of the specific sites evaluated were as follows: retrocervical space (89.4%, 92.3%, 96.7%, 77.4%, 90.2%); rectosigmoid (86.0%, 92.9%, 93.5%, 84.8%, 89.1%); bladder (23.1%, 100%, 100%, 88.8%, 89.1%); ureters (50.0%, 100%, 95.5%, 95.7%); and vagina (72.7%, 100%, 100%, 96.4%, 96.7%). CONCLUSION: MRI demonstrates high accuracy in diagnosing DIE in the retrocervical region, rectosigmoid, bladder, ureters, and vagina.

Quantitative assessment of eosinophiluria in Schistosoma haematobium infections: a new marker of infection and bladder morbidity.

Eosinophiluria, as quantified by measuring eosinophil cationic protein (ECP) in urinary extracts, microhematuria, egg excretion, and ultrasound-detectable bladder pathology were recorded in Schistosoma haematobium-infected Tanzanian school children at a baseline survey and during an 18-month post-treatment follow-up study. Significant correlations were seen between urinary ECP levels, intensity of infection, and bladder pathology. Treatment resulted in a marked reduction in prevalence and intensity of infection, in a delayed and less marked reduction in ECP levels, and in a resolution of pathology. The overall diagnostic efficiency of the ECP test (cut-off value for the ECP > or =5 ng/ml) in relation to infection was comparable with that of egg count and microhematuria, but with a better sensitivity than a single egg count. In relation to bladder pathology, the diagnostic performance of the ECP test (cut-off value for the ECP > or =25 ng/ml) exceeded that of a single egg count. In addition, the ECP was better in discriminating between different grades of bladder pathology. The present study points to the ECP as a useful marker of both S. haematobium infection and of associated bladder morbidity reflecting the inflammatory status of the bladder wall.

Primary staging of urinary bladder carcinoma: the role of MRI and a comparison with CT.

Since the introduction, pelvic MRI has been considered the best non-invasive technique for primary staging of urinary bladder cancer. Before using MRI an understanding of normal and pathological MR images of the urinary bladder is essential. This review therefore describes the MR anatomy of the urinary bladder as well as the appearances of carcinoma. MRI plays an important clinical role in staging the primary tumour. In superficial tumours, clinical staging, which includes transurethral biopsy, is the best technique. For invasive tumours, MRI is superior to other techniques such as CT scanning, transvesical ultrasonography and clinical staging. A limitation of both MRI and CT scanning is their inability to recognize minimal tumour growth in the muscle layer of the bladder wall, or to differentiate between post-transurethral resection oedema and tumour. Therefore, in all patients with urinary bladder cancer staging should preferably start with MRI followed by clinical staging. Unfortunately, however, because of the high cost of this strategy, MRI has to be reserved for staging deeply invasive and superficial poorly differentiated tumours.

Acrolein mercapturates: synthesis, characterization, and assessment of their role in the bladder toxicity of cyclophosphamide.

Acrolein is the metabolite of cyclophosphamide (CP) believed to be involved in the bladder toxicity associated with this anticancer drug. The mechanism by which this extremely reactive intermediate is delivered to the bladder is not known. Glutathione (GSH) readily conjugates with acrolein, and the acrolein mercapturate S-(3-hydroxypropyl)-N-acetylcysteine (3-hydroxy-PrMCA) has been found in the urine of animals and man given CP. The objectives of this study were to prepare and characterize synthetic standards of the GSH acrolein adduct (3-oxopropyl)glutathione (3-oxoPrGSH), the acrolein mercapturates S-(3-oxopropyl)-N-acetylcysteine (3-oxoPrMCA) and 3-hydroxyPrMCA, and the S-oxidation product of 3-oxoPrMCA (3-oxoPrMCA S-oxide). In addition, the release of acrolein from, and the bladder toxicity of, these conjugates was determined. 3-OxoPrGSH and 3-oxoPrMCA were prepared with a 99% yield by condensing acrolein with GSH and N-acetylcysteine, respectively. 3-HydroxyPrMCA was prepared with a 63% yield by refluxing 3-chloropropanol and N-acetylcysteine in a basic medium. Oxidation of 3-oxoPrMCA with H2O2 was used to prepare 3-oxoPrMCA S-oxide. By decreasing the reaction time to 1 h, and adjusting the ratio of 3-oxoPrMCA to H2O2, the yield of 3-oxoPrMCA S-oxide was increased to 96%. The anhydrous aldehyde, 3-oxoPrMCA, afforded characteristic aldehydic proton resonances (1H NMR) in deuterated dimethyl sulfoxide. New resonances were observed in deuterated water, indicating a 75% hydration of the aldehyde to the corresponding geminal diol. This phenomenon was enhanced with 3-oxoPrMCA S-oxide where approximately 100% hydration of the aldehyde to the corresponding geminal diol was observed. When incubated at 25 degrees C in 100 mM potassium phosphate buffer containing 1 M KCl, pH 8.0, 3-oxoPrMCA released approximately 6% and 3-oxoPrMCA S-oxide released approximately 16-18% of the theoretical maximum yield of acrolein after 30 min, as indicated by an increase in absorbance at 210 nm and confirmed by trapping this aldehyde as a semicarbazone. There was less than a 2% yield of acrolein from 3-hydroxyPrMCA or 3-oxoPrGSH under similar conditions. At pH 7.4 the release of acrolein from 3-oxoPrMCA and 3-oxoPrMCA S-oxide was decreased by 50%. An assay where aldehydes are reacted with m-aminophenol in acid media produced fluorescence consistent with 72%, 46%, 23%, and 1% yields of acrolein from 3-oxoPrMCA S-oxide, 3-oxoPrMCA, 3-oxoPrGSH, and 3-hydroxyPrMCA, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Ultrasonographic assessment of the regression of bladder and renal lesions due to Schistosoma haematobium after treatment with praziquantel.

The effect of praziquantel on urinary tract lesions due to Schistosoma haematobium was assessed by ultrasound in an endemic village in Niger. Ten months after treatment with praziquantel, bladder and renal lesions among the 149 patients were assessed. The parasitological cure rate was 87%. Ultrasonography proved to be an excellent tool to assess pathological changes. It is reliable, quickly performed, well accepted by the community and permits the definition of a "regression-rate" of the pathological lesions. Ten months after treatment, the "regression-rate" of bladder lesions was 68% and of renal lesions was 73%. The presence of bladder lesions had a negative influence on the regression of renal lesions. Nearly all renal lesions, without bladder lesions, regressed within the ten months period of observation. This study permitted the identification of a group of persons whose bladder lesions did not regress and who were possibly more vulnerable to the development of bladder cancer, thus requiring long-term follow-up.

[Laboratory diagnosis in kidney- and bladder diseases]. / Labordiagnostik bei Nieren- und Blasenerkrankungen

The laboratory diagnostic spectre in diseases of the kidneys and the urinary bladder is demonstrated in form of a 3-step-programme. The concentration of suitable investigation methods in complexes allows a rational and economical diagnostics for patient and physician. A standardisation of the diagnostics in out-patient department and clinic essentially contributes to the reduction of excessive work in overcharged laboratories as well as to the shortening of the patient's stay in the hospital.