Evaluation of the Paris System in atypical urinary cytology.

OBJECTIVE: Our aim was to evaluate the Paris System for reporting urinary cytology, especially in the field of atypia. METHODS: During the last year, 104 urinary cases had atypical cytology. These cases were reviewed and reclassified by three cytopathologists using the Paris criteria. Cyto-histological correlation was performed in 47 cases. Additionally, all cytology diagnoses were correlated with double immunocytochemistry for p53 and CK20 result. Interobserver consistency was also evaluated. RESULTS: Out of 104 atypical cases, 30 were classified as benign, 49 atypical and 25 suspicious for high-grade urothelial carcinoma (HGUC). Diagnostic consistency between the three observers reached 93.27%. Using the new criteria, only 47.1% of the cases remained in the atypical category. The rate of HGUC histology was 14.3%, 26.7% and 96% in the benign, atypical and suspicious for HGUC cytological categories, respectively. Immunocytochemistry positivity was observed in 25.9%, 41.8% and 80% of the cases in the three diagnostic groups. CONCLUSIONS: The Paris System for reporting urinary cytology provides clear, easy to adopt criteria, which lead to diagnostic categories with clinical significance, facilitating patient management decisions.

Evaluation of double immunocytochemical staining for CK20 and P53 as a potential adjunct to cytology for urothelial cancer diagnosis.

OBJECTIVE: To evaluate double immunocytochemical staining with p53 and CK20, as a tool for improving the accuracy of urinary cytology. The aim of the present study was to clarify the diagnostic significance of the expression of these markers and to investigate the possibility of using this information for better monitoring of bladder cancer patients during follow-up. MATERIAL AND METHODS: One hundred and twenty-five urine cytology cases were retrieved with corresponding histology from our files. One ThinPrep® smear was available for each of them and dual immunocytological staining for p53 and CK20 was performed. Eleven cases were excluded from the study because of hypocellularity. The material comprised 58 malignant, 36 atypical and 20 negative for malignancy cases. Immunocytochemistry was evaluated by two cytopathologists, blinded to the histological diagnosis or follow-up data. A cut-off threshold of five stained atypical cells, according to the literature, was used for evaluation. RESULTS: Fifty-two out of 58 malignant cases were positive for at least one of the markers (89.6%). In the atypical and negative groups, 18 (50%) and 5 (25%) cases were positive, respectively. Accuracy parameters evaluation for cytology versus the combination of cytology with immunocytological staining were: sensitivity 73.4% versus 91.1%, specificity 100% versus 74.3%, positive predictive value (PPV) 100% versus 88.9% and negative predictive value (NPV) 62.5% versus 78.8%. CONCLUSIONS: Double immunocytochemical staining for p53 and CK20 is easy to perform and evaluate and can improve cytology sensitivity. It is helpful in establishing a diagnosis of malignancy and may be used as a triage tool to select patients that require cystoscopy during clinical follow-up.

Audit of cytology of upper urinary tract.

OBJECTIVE: Cytology is an essential tool for the investigation of urinary tract malignancy. In this audit, we aimed to assess our laboratory performance in the diagnosis of upper urinary tract malignancy and to use the information provided to improve our service. METHODS: We retrieved cytology reports of upper urinary tract specimens from two periods, re-evaluated the cases, compared the reports with histology data and estimated the sensitivity, specificity and positive predictive value (PPV). In the time interval between the two periods, we adopted new terminology, established better communication with clinicians and gained experience in the field. Finally, the data from the two periods were compared. RESULTS: In phase A, we estimated a sensitivity of 73%, specificity of 86% and PPV of 84.6%. As a result of the cytological re-evaluation, correlation with histology and clinical follow-up, plus communication with the clinicians during the audit, we established new terminology and a new request form. A three tiered grading system of atypia (mild, moderate and severe) was replaced by a two tiered grading system. The first category "atypia probably benign" corresponded to "mild atypia" while the second category "atypia, not otherwise specified" corresponded to "moderate atypia". The cases diagnosed as "severe atypia" were reclassified as "suspicious for malignancy". In phase B, the sensitivity, specificity and PPV were 75%, 89% and 90%, respectively. CONCLUSIONS: Our laboratory performance is in concordance with reported data and has been improved through this study. The audit process is extremely valuable for the identification of problems, for taking action and, finally, for the improvement of the clinical cytology service in the field of upper urinary tract malignancy.

Doxazosin for the management of distal-ureteral stones.

PURPOSE: To evaluate the efficacy of doxazosin in inducing spontaneous passage of stones in the distal ureter and to compare its efficacy according to the size of the stone. PATIENTS AND METHODS: Seventy-three patients with a mean age of 46.38 +/- 10.17 years who presented with a distal-ureteral stone were divided into four groups according to stone size and drug treatment: <5 mm without doxazosin (group A; n=15); 5-10 mm (group B; n=16); <5 mm with doxazosin 4 mg/day for 4 weeks (group C; n=20); and 5-10 mm with doxazosin 4 mg/day for 4 weeks (group D; n=22). Groups A and B served as controls for groups C and D, respectively. RESULTS: Spontaneous stone passage was documented in 9 patients (60%) in group A v 17 (85%) in group C (P=0.047) and 7 (43.75%) in group B v 16 (72.73%) in group D (P=0.036). The average expulsion time was 8.78 +/- 1.09 days in group A v 7.59 +/- 0.80 days in group C (P=0.004) and 12.14 +/- 1.35 days in group B v 7.06 +/- 1.29 days in group D (P<0.0001). The number of pain episodes in group D patients was significantly lower than in group B (P +/- 0.0078). CONCLUSIONS: Doxazosin treatment proved to be safe and effective for distal-ureteral stones, as determined by earlier expulsion, decreased colic frequency, and absence of side effects. The efficacy of doxazosin was significantly higher for 5-to 10-mm stones than for smaller ones.

Ureteral injuries during gynecologic surgery: treatment with a minimally invasive approach.

PURPOSE: To report the safety and efficacy of percutaneous nephrostomy and primary antegrade recanalization for treatment of iatrogenic ureteral strictures after gynecologic surgery. PATIENTS AND METHODS: Ten women had symptoms suggestive of ureteral obstruction during the immediate postoperative period (5 days-1 week after surgery). Under analgesia and conscious sedation, standard percutaneous nephrostomy was performed, and a long 7F sheath was placed in the upper ureter. The obstructions were traversed with the aid of a 0.0035-inch Glidewire and a 5F angled Glide catheter (Terumo, Japan). Subsequently, the areas were dilated with angioplasty balloons to a maximum diameter of 7 mm. Finally, an 8F percutaneous internal/external nephroureteral drainage stent was inserted to secure ureteral patency. Follow-up was carried out by serial nephrostomography until removal of the stent and by renal ultrasonography thereafter. RESULTS: Twelve obstructions with a mean length of 1.4 cm (range 0.4-1.9 cm) were managed. The technical success rate was 100%. No major complications occurred, and normal renal function was restored. The mean follow-up was 12 months. In 60% of the patients, a patent ureter was depicted at 1 week, whereas in four patients, repeat dilation of the obstructed segment was required. The stents were removed after a mean period of 4.8 weeks. CONCLUSION: Percutaneous nephrostomy and primary antegrade ureteral balloon dilation is safe and efficacious for treating ureteral injury after pelvic surgery and obviates open surgical manipulations.

Biopsy-related hemorrhage of renal allografts treated by percutaneous superselective segmental renal artery embolization.

INTRODUCTION: Biopsy-related vascular injuries in renal transplants are rare, but they can lead to dramatic clinical symptoms prompting immediate treatment. Transcatheter embolization is a minimally invasive technique used to treat some forms of arterial bleeding. This study evaluated the efficacy of this technique in iatrogenic biopsy-related vascular lesions in renal allografts. MATERIALS AND METHODS: Over the last eight years, six patients with severe renal hemorrhage were admitted to the angiography department of our hospital for evaluation and possible further treatment. All of them had a history of previous biopsy of a transplanted kidney. They all presented with clinical signs of hemodynamic instability. Angiographic investigation of the kidneys preceded further intervention in all cases. All underwent hyperselective embolization of the specific bleeding vessel with the use of microcoils and/or gelfoam particles. RESULTS: Successful embolization of the feeding artery could be performed in all patients. Superselective segmental renal artery embolization had a successful outcome concerning a steady renal function and a stable clinical course. No complications occurred. CONCLUSION: Transcatheter embolization is a safe and efficient endovascular technique to treat biopsy-related vascular injuries in renal transplants. Immediate clinical success and significant benefit in renal function can be obtained, and the longevity of the allograft after successful embolization mainly depends on the natural outcome.

Adjuvant chemotherapy with paclitaxel and carboplatin in patients with advanced carcinoma of the upper urinary tract: a study by the Hellenic Cooperative Oncology Group.

PURPOSE: Radical surgery represents the treatment of choice for carcinoma of the upper urinary tract. Nevertheless, approximately 50% of patients with stage T >/= 3 or lymph node involvement die from their disease, mainly as a result of the development of distant metastases. Therefore, there is a need for effective adjuvant systemic treatment. We prospectively studied a cohort of patients who underwent surgery for high-risk carcinoma of the upper urinary tract to assess the feasibility of the combination of paclitaxel and carboplatin as adjuvant treatment. PATIENTS AND METHODS: Thirty-six patients with tumor stage >/= 3 or lymph node involvement were treated with four cycles of paclitaxel at 175 mg/m(2) and carboplatin (area under the curve 5, Calvert Formula) every 3 weeks following surgery. RESULTS: Median follow-up was 40.6 months. Chemotherapy was well tolerated with 32 patients (89%) receiving full carboplatin and paclitaxel doses without delays. The most frequent grade 3/4 toxicity was neutropenia (39%), which was complicated with fever in only one case (3%). Nonhematologic grade 3 or 4 toxicities were reported in only one case. Five-year survival was 52% (95% CI, 35% to 69%), while 5-year disease-free survival was 40.2% (95% CI, 15.8% to 64.6%). Local failure rate was 30%, as opposed to 17% of patients who developed distant metastases. No patients with grade 2 tumors relapsed during follow-up, as opposed to 60% of patients with grade 3 tumors. CONCLUSION: Adjuvant chemotherapy with paclitaxel and carboplatin is feasible and may reduce the risk of distant metastases in high-risk upper urinary tract carcinoma.

In vivo epicardial force and strain characterisation in normal and MLP-knockout murine hearts.

The study's objective is to quantify in vivo epicardial force and strain in the normal and transgenic myocardium using microsensors.Male mice (n = 39), including C57BL/6 (n = 26), 129/Sv (n = 5), wild-type (WT) C57 × 129Sv (n = 5), and muscle LIM protein (MLP) knock-out (n = 3), were studied under 1.5% isoflurane anaesthesia. Microsurgery allowed the placement of two piezoelectric crystals at longitudinal epicardial loci at the basal, middle, and apical LV regions, and the independent (and/or concurrent) placement of a cantilever force sensor. The findings demonstrate longitudinal contractile and relaxation strains that ranged between 4.8-9.3% in the basal, middle, and apical regions of C57BL/6 mice, and in the mid-ventricular regions of 129/Sv, WT, and MLP mice. Measured forces ranged between 3.1-8.9 mN. The technique's feasibility is also demonstrated in normal mice following afterload, occlusion-reperfusion challenges.Furthermore, the total mid-ventricular forces developed in MLP mice were significantly reduced compared to the WT controls (5.9 ± 0.4 versus 8.9 ± 0.2 mN, p < 0.0001), possibly owing to the fibrotic and stiffer myocardium. No significant strain differences were noted between WT and MLP mice.The possibility of quantifying in vivo force and strain from the normal murine heart is demonstrated with a potential usefulness in the characterisation of transgenic and diseased mice, where regional myocardial function may be significantly altered.

Treating anterior vaginal wall prolapse with polypropylene mesh via the transoburator route minimizing the complications with the use of preventing measures. A prospective study with 2-year follow-up.

AIM: Our objectives were to evaluate the efficacy of the Perigee™ transoburator (TOT) mesh kit (American Medical Systems [AMS]-Minnetonka, MN, USA) in the treatment of ≥ stage 2 symptomatic AVP following a 2-year follow-up and to discuss the role of the pre-, peri- and postoperative measures taken to prevent complications METHODS: A total of 50 patients were eligible and were subjected to AVP surgical treatment with the use of the Perigee™ system. All patients were followed-up at 4 weeks, 2, 6, 12 and 24 months. Our primary objective was treatment success and efficacy after anatomical examination of the patient at the 24-month follow-up. Efficacy was defined as ≤ stage I AVP. All patients completed the 24-month follow-up. Our secondary objective was to examine the complication rates in relation to the use of preventative measures. RESULTS: The proportion of patients with II to III stage significantly decreased postoperatively (P<0.001). A significantly improvement was found in all POP-Q measures (P<0.05) while mean vaginal length was similar to the preoperative values. At 24-month follow-up, 45 women were defined as ≤ stage I, indicating a 90% objective success rate (95% CI: 81.4-98.6%). Two patients had vaginal mesh extrusion (4.0%) both treated with conservative measures. No erosions occurred at any point postoperatively. De novo dyspareunia was reported in two of the 17 cases (11.8%) who reported being sexually active at follow-up. One of the two had also mesh extrusion and with appliance of the vaginal estrogen and the office excision of the exposed mesh the symptoms were resolved, while the other was treated with vaginal estrogen. Two cases (4.0%) reported de novo incontinence and both were treated with a TOT sling (monarc AMS) procedure three months after the cystocele repair. Three cases (6.0%) reported pain vaginal pain postoperatively and again our treatment of choice was vaginal estrogen cream for 4 weeks with the addition of antinflammatories for 10 days and their symptoms resolved. CONCLUSIONS: The treatment of AVP with the use of Perigee™ TOT system can be both effective and safe. The goal is the improvement of the quality of life of the patients and is important to avoid or to keep as minimum as possible the complications. Main complications that the surgeon should bear in mind are the vaginal erosion, vaginal mesh extrusion, de novo dyspareunia, de novo incontinence and vaginal pain. Proper patient selection, the appliance vaginal estrogen cream pre- and postoperatively and following strict surgical principles are the mainstay of the success of the TOT operation. It is crucial for POP procedures to be performed by high-volume surgeons in this field, with extensive knowledge of the pelvic floor anatomy and the mesh's characteristics. Of course this is a small study and further clinical studies with larger number of patients are needed in order to further scientific evaluate the TOT operation.

Predictive value of topoisomerase II alpha immunostaining in urothelial bladder carcinoma.

AIMS: The nuclear enzyme DNA topoisomerase II has been shown to be required for chromatin condensation and chromosomal segregation during mitosis; its isoform topo II alpha is linked with active cell proliferation in mammalian cells. The aim of this study was to examine the relation of the expression of topo II alpha to the biological behaviour of conventional urinary bladder cancer. METHODS: Formalin fixed, paraffin wax embedded tissue from 94 specimens of bladder urothelial cancer were immuno-histochemically stained for topo II alpha. For each case, a topo II alpha index was determined. A similar index had been determined for Ki-67, a known cell proliferation marker. Each case had also been graded, staged, and evaluated for DNA ploidy as well as for p53 and bcl-2 immunoreactivity. RESULTS: Raised topo II alpha expression (in > or = 10% of malignant nuclei) correlated with two adverse prognosticators--high grade (p = 0.027) and invasion of the muscularis propria (p = 0.013), but with no other evaluated parameter. By multivariate survival analysis using Cox's proportional hazard model, high expression of topo II alpha was found to be predictive for worse survival (p = 0.0047). Patients' age, tumour stage, and grade were also retained as independent prognostic factors (p = 0.0349, p = 0.00005, and p = 0.0130, respectively). The negative influence of increased topo II alpha immunopositivity on patients' survival was also seen in the subgroup of patients with non-muscle invasive carcinomas (p = 0.0004), in patients with a bcl-2 negative phenotype (p = 0.0330), and in those with low Ki-67 indices (p = 0.0341). CONCLUSIONS: Because topo II alpha and Ki-67 failed to demonstrate a significant interrelation, they appear to be different molecules that both function at separate phases in the complex process of cellular proliferation. The assessment of increased topo II alpha immunoreactivity in specimens from urothelial carcinomas might help to select patients (particularly among those with superficial tumours) in the worse prognostic categories for new therapeutic strategies.

Pathogenesis of adenocarcinoma complicating ureterosigmoidostomy. Experimental observations.

Columnar metaplasia, dysplasia, and adenocarcinoma occurred in patches of bladder epithelium exposed to the fecal stream in rats. This suggests that such tumors complicating ureterosigmoidostomy may arise from ureteric epithelium, and that urine is not essential for their development.

Evaluation of overexpression of p53 tumor suppressor protein in superficial and invasive transitional cell bladder cancer: comparison with DNA ploidy.

OBJECTIVES: p53 tumor suppressor gene is considered to play a significant role in carcinogenesis. Mutations in the p53 are the most frequent genetic abnormalities encountered in human malignancies. Our aim was to investigate the expression of p53 oncoprotein in superficial and invasive transitional cell bladder cancer (TCC) as well as its correlation with established prognostic factors, such as histologic grade, tumor stage, DNA content, and survival. METHODS: Forty-five patients with superficial TCC (Ta-T1) and 42 with invasive TCC (T2-T4) were included in our study. Material from transurethral biopsy was examined using an immunohistochemical method and the monoclonal antibody Pab 1801. RESULTS: p53 tumor suppressor protein was overexpressed in 48.3% of TCC cases and more frequently in invasive than superficial TCCs (P = 0.03) and undetectable in the tumor adjacent to normal tissue. p53 positivity was related to the degree of differentiation and with the stage of the disease of invasive TCCs (P = 0.03 and P = 0.004, respectively), whereas no statistical significance was documented for superficial TCCs. Moreover, p53 overexpression demonstrated a statistical significance with DNA ploidy in superficial Ta-T1 tumors (P = 0.04) and was suggestive in invasive T2-T4 tumors (P = 0.08). There was no correlation of recurrence related to p53-positive superficial tumors (P = 0.29). Patients with p53-positive invasive TCCs showed statistically significant worse survival (P = 0.007), but in multivariate analysis, p53 positivity is not independently related to poor overall survival (P = 0.30). When we combined ploidy and p53 status, we realized that the subset of patients with aneuploidy and p53 positivity had the worst prognosis (P = 0.008). CONCLUSIONS: The results suggest the involvement of p53 protein as a late event in bladder carcinogenesis. p53 does not seem to be a prognostic marker for recurrences of superficial tumors and is not independently related to survival. The aneuploidy of tumors correlates with the p53 positivity in bladder cancer. The combined expression of aneuploidy and p53 positivity in invasive tumors has strong association with the survival of patients.

Comparative evaluation of the BTAstat test, NMP22, and voided urine cytology in the detection of primary and recurrent bladder tumors.

OBJECTIVES: This prospective study was undertaken to evaluate the diagnostic efficacy of the BTAstat test and nuclear matrix protein (NMP22) compared with voided urine cytology (VUC) in the detection of primary and recurrent bladder cancer. METHODS: A total of 147 patients provided a single voided urine sample for the BTAstat test, NMP22, and cytology prior to cystoscopy. Eighty-five of them had no bladder cancer history, whereas the remaining 62 were monitored for superficial bladder cancer. A group of 21 healthy age-matched volunteers were also enrolled in the study. RESULTS: Bladder cancer was confirmed histologically in 99 patients, of which 62 had primary tumors and 37 had recurrent ones. The overall sensitivity and specificity were 71.7% and 56.5% for the BTAstat test, 62.6% and 73. 9% for NMP22, and 38.4% and 94.2% for VUC. The optimal threshold value for NMP22 calculated with receiver operating characteristics curve, was 8 U/mL. BTAstat test was significantly more sensitive than VUC in detecting bladder cancer in all stage and grade subgroups, except GIII. On the contrary, NMP22 was significantly more sensitive than VUC only in stage Ta, grade I and II patients. BTAstat test had higher but not significantly different sensitivity than NMP22. CONCLUSIONS: Our data indicate a superiority of both BTAstat test and NMP22 over VUC in the detection of bladder cancer. Comparing BTAstat test with NMP22, the former proved to be more sensitive, whereas the latter was more specific. Ruling out diseases with potential interference can increase the overall specificity of both tests. False-positive results of either test in patients followed up for bladder cancer seem to correspond to future recurrences.

MMP-3 mRNA and MMP-3 and MMP-1 proteins in bladder cancer: a comparison with clinicopathologic features and survival.

Matrix metalloproteinases (MMPs) are proteolytic enzymes important at several points during multistep neoplastic progression. Although MMP-1 and MMP-3 have been implicated in the progression of various human cancers, their expression in bladder cancer has not been addressed. Immunohistochemistry (Strept-ABC-HRP method) and in situ hybridization were performed to detect MMP-1 protein, MMP-3 protein, and MMP-3 mRNA, respectively, in 59 transitional cell bladder carcinomas. To assess the role of these MMPs in bladder cancer, their expression was evaluated in relation to known clinicopathologic parameters and patients' disease-free and overall survival. Immunoreactivity for MMP-1 and MMP-3 proteins was observed in the cytoplasm of cancer cells in 30.5% and 24% of samples, respectively. Transcripts for MMP-3 mRNA were localized in stromal cells in 71.2% of cases and in cancer cells in 49% of cases. MMP-1 immunoreactivity demonstrated a statistically significant association with deeply invasive and grade III tumors versus superficial and lower grade tumors. MMP-3 protein immunoreactivity and MMP-3 mRNA immunolocalization did not associate with the parameters studied. However, MMP-3 mRNA localization in stromal cells demonstrated a borderline association with poor patients' disease-free and overall survival. In conclusion, the authors' results demonstrate a differential expression between MMP-1 and MMP-3 in bladder cancer; MMP-1 appears to participate in invasiveness and possibly in loss of differentiation in urothelial carcinomas in contrast to MMP-3.

Immunohistochemical expression of transforming growth factor beta 1 and nm-23 H1 antioncogene in prostate cancer: divergent correlation with clinicopathological parameters.

BACKGROUND: Prostate cancer is one of the main causes of morbidity and mortality among men. Several oncogenes and growth factors have been studied in an attempt to explain the molecular basis of carcinogenesis and progress of this carcinoma. In this study we correlated the immunohistochemical expression of antioncogene nm-23 H1 and transforming growth factor beta 1 (TGF-beta 1) with the clinical stage, PSA values, Gleason score and survival in prostate cancer. MATERIALS AND METHODS: Fifty nine patients with prostate cancer were evaluated. PSA measurement, Gleason score determination and clinical staging were recorded for all the patients by the time of initial diagnosis and prior to any treatment. Follow-up ranged from 12 to 40 months. Tissue sections from representative areas of the tumors were immunohistochemically stained for nm-23 H1 and TGF-beta 1. The expression of these markers was correlated with stage, PSA values, Gleason score and survival. RESULTS: There was a negative correlation between nm-23 H1 staining and tumor stage and grade. High grade (Gleason score 8-10) and stage D tumors showed weaker staining than low stage and grade tumors. There was a positive correlation between TGF-beta 1 staining, tumor stage and serum PSA levels. Additionally, TGF-beta 1 proved to be a negative predicting factor for patient survival. In tumors expressing both markers, TGF-beta 1 was the one to determine the aggressiveness of the carcinoma. CONCLUSIONS: nm-23 H1 appears to be a tumor suppressor gene in prostate cancer, while TGF-beta 1 may act as a stimulating agent provoking aggressive behavior and metastasis. Their immunohistochemical staining may constitute complementary information in the evaluation of prostate cancer patients.

Prognostic value of E-cadherin, beta-catenin, P120ctn in patients with transitional cell bladder cancer.

BACKGROUND: Loss of E-cadherin-catenin mediated adhesion is known to play a major role in tumour progression in many human carcinomas. MATERIALS AND METHODS: By means of immunohistochemistry, we have investigated the expression of E-cadherin, beta-catenin and p120ctn in 102 transitional cell bladder carcinomas (TCCs) and statistically analysed these expressions with known clinicopathological parameters and patient survival. RESULTS: Abnormal expression of E-cadherin, beta-catenin and p120ctn was associated with high grade and high stage of TCCs (p < 0.001). Abnormal beta-catenin expression demonstrated a statistically significant correlation with poor patient survival (p = 0.03) while abnormal E-cadherin expression was associated with poor survival in patients with muscle invasive TCCs (p = 0.025). However, in multivariate statistical analysis a suggestive association with poor survival was observed only for E-cadherin (p = 0.06). Simultaneous abnormal expression of all the molecules demonstrated an association of suggestive significance with poor patient survival (p = 0.07). CONCLUSION: E-cadherin expression may be a useful prognostic marker in patients with invasive TCCs.

Restoration of low resolution metabolic images with a priori anatomic information: 23Na MRI in myocardial infarction.

A new iterative extrapolation image reconstruction algorithm is presented, which enhances low resolution metabolic magnetic resonance images (MRI) with information about the bounds of signal sources obtained from a priori anatomic proton ((1)H) MRI. The algorithm ameliorates partial volume and ringing artefacts, leaving unchanged local metabolic heterogeneity that is present in the original dataset but not evident at (1)H MRI. Therefore, it is ideally suited to metabolic studies of ischemia, infarction and other diseases where the extent of the abnormality at (1)H MRI is uncertain. The performance of the algorithm is assessed by simulations, MRI of phantoms, and by surface coil 23Na MRI studies of canine myocardial infarction on a clinical scanner where the injury was not evident at (1)H MRI. The algorithm includes corrections for transverse field inhomogeneity, and for the leakage of intense signals into regions of interest such as 23Na MRI signals from ventricular blood ringing into the myocardium. The simulations showed that the algorithm reduced ringing artefacts by 15%, was stable at low SNR ( approximately 7), but is sensitive to the positioning of the (1)H MRI boundaries. The 23Na MRI showed hyperenhancement of regions identified as infarcted at post-mortem histological staining. The areas of hyperenhancement were measured by five independent observers in four 23Na images of infarction reconstructed with and without the algorithm. The infarct areas were correlated with areas determined by post-mortem histological staining with coefficient 0.85 for the enhanced images, compared to 0.58 with the conventional images. The scatter in the amplitude and in the area measurements of ischemia-associated hyper-enhancement in 23Na MRI was reduced by the algorithm by 1.6-fold and by at least 3-fold, respectively, demonstrating its ability to substantially improve quantification of the extent and intensity of metabolic changes in injured tissue that is not evident by (1)H MRI.

Calcium metabolism in children suffering from homozygous beta-thalassaemia after oral administration of 47Ca.

The study of calcium metabolism in ten thalassaemic children comperatively with controls after oral administration of 47Ca has shown diminished intestinal absorption. It is suggested that this finding is propably related in part with the pathogenesis of the osteoporosis in thalassaemia.

Left ventricular ejection fraction and volumes calculated from dual gated SPECT myocardial imaging with 99Tcm-MIBI.

Dual gated (DG) cardiac single photon emission computed tomographic (SPECT) studies at end-diastole (ED) and end-systole (ES) were acquired in 27 ischaemic heart disease (IHD) patients after intravenous injection of 555-740 MBq 99Tcm-MIBI. Acquisition parameters were: 180 degrees from LPO to RAO, 32 projections, 64 x 64 matrix, 75 cardiac beats per projection, 80 ms at ED and 80 ms at ES for each cardiac cycle. A computer program was developed to calculate the ED and ES left ventricular (LV) volumes and LV ejection fraction (EF). The computational approach is interactive, semi-automatic and iterative with built-in visual quality control. Short axis slices are used with corresponding ED and ES slices processed as pairs from apex to base. Left ventricular cavity pixels are identified and summed on a slice-by-slice basis. Myocardial pixels are similarly identified. The computed LVEF and ED and ES volumes have been correlated with those from contrast ventriculography (CV). The mean calculated EF for 27 patients was 53.6 +/- 10.7% from DG SPECT versus 55.3 +/- 12.1% from CV (NS). The EF linear correlation coefficient was r = 0.97.

Acute prostatitis: which antibiotic to use first.

Six antimicrobial agents were administered to 48 patients (divided in 6 groups) who underwent prostatectomy. Half of the patients received the antibiotic in a single dose one hour before the operation and the rest in divided doses 24 hours before the operation. The concentration levels in serum and in prostatic tissue were measured for each of the antibiotics and for each mode of administration. The obtained ratios of prostatic tissue to serum concentrations and the relative antimicrobial activity to local pathogens of each agent indicate that the agent of choice for prostatic disease is netilmicin followed by aztreonam, cefuroxime and the ticarcillin-clavulanic acid combination.