Using MRI to evaluate anatomic significance of aortic bifurcation, right renal artery, and conus medullaris when locating lumbar vertebral segments

OBJECTIVE: This study evaluated the anatomic significance and sites of aortic bifurcation, right renal artery, and conus medullaris when locating lumbar vertebral segments on MRI. SUBJECTS AND METHODS. The study group was composed of 210 patients who underwent MRI of the lumbosacral spine. The position of aortic bifurcation was evaluated using MRI. Midline and sagittal MRI were also assessed to identify the proximal portion of the right renal artery and the tip of the conus medullaris. These locations were recorded in relation to the upper or lower half of the adjacent vertebral body or the adjacent intervertebral disk space. RESULTS: The most common site of aortic bifurcation was at the L4 vertebra (83%). In most patients two separated iliac arteries were apparent at the level of the L4-L5 disk space (93%), and the right renal artery was located between the lower half of the L1 vertebra and the upper half of the L2 vertebra (92%). The position of the conus medullaris was variably located, and the most frequent site was at the L1 vertebra (56%). CONCLUSION: The aortic bifurcation, the right renal artery, and the combination of these structures can be reliable landmarks for determining the lumbar vertebral segments on MRI or CT. However, conus medullaris cannot be considered a good landmark because of its variable locations.     

Increased nephron volume is not a cause of supranormal renographic differential renal function in patients with ureteropelvic junction obstruction

PURPOSE: Increasing clinical importance is being placed on the role of differential renal function (DRF) in the management of congenital ureteropelvic junction obstruction. Supranormal DRF of the hydronephrotic kidney on renal scan is a puzzling phenomenon and is hypothesized to be due to an increase in single nephron filtration or nephron volume without sound evidence. We studied the histopathological changes of hydronephrotic kidneys to determine whether glomerular hypertrophy underlies supranormal DRF. MATERIALS AND METHODS: We retrospectively evaluated the records of 3 females and 32 males with unilateral congenital hydronephrosis who underwent pyeloplasty. Mean patient age at operation was 12.6 months (range 0.1 to 144). Needle biopsies from 3 different sites at the lower pole of the kidney were performed during surgery. To evaluate the presence of glomerular hypertrophy, the maximal planar area of glomeruli was measured under light microscopy using an image analyzer. Tissue samples obtained from kidneys without a history of urinary tract disease at autopsy were used as controls. The mean glomerular areas of the patient and control groups were evaluated according to DRF and age. RESULTS: The mean glomerular area values of the patient group were smaller than those of the control group, except for 4 patients. The glomerular areas of the hydronephrotic kidneys with supranormal DRF were not significantly different from those of the control group. Instead, the probability of larger renal glomeruli increased with decreasing DRF (p = 0.1155). CONCLUSIONS: Increased nephron volume can be discounted as a cause of supranormal DRF.     

Voiding diary for the evaluation of urinary incontinence and lower urinary tract symptoms: prospective assessment of patient compliance and burden

AIMS: Voiding diary duration may be related to patient compliance and burden. To test this hypothesis, we evaluated patient compliance and burden. METHODS: Between January and July 2002, we prospectively evaluated 162 patients (57 males and 105 females, mean age 53.0, range 20-81 years) with stress urinary incontinence or lower urinary tract symptoms. At the initial visit, all patients underwent a detailed clinical evaluation including an International Prostate Symptom Score (I-PSS) assessment and were randomly requested to complete 2-day, 3-day, or 7-day voiding diaries (the three study groups). At the second visit, a simple self-administered questionnaire was completed by all patients. The questionnaire included 11 items on subject demographics and voiding diary-keeping. RESULTS: No significant differences were found in either the accuracy of diary-keeping or the daily average number of omissions when the three groups were compared. However, as the diary duration increased, the mean burden scores increased (P = 0.005), and the mean preferred duration of the diary in the 7-day group was significantly higher than that of the 2-day or 3-day groups (P < 0.001). After categorizing patients into two groups according to the degree of patient burden, members of the group with a greater perceived burden were found to have a significantly higher I-PSS quality of life score (P = 0.045) and to have kept a diary for a longer time (P = 0.038). CONCLUSIONS: Our results suggest that keeping a diary for 7 days may increase patient burden and thus, we recommend that the 7-day diary should be reduced to cover fewer days.     

Phyllodes tumor of the seminal vesicle: case report and literature review

A 39-year-old man presented with urinary retention and lower abdominal discomfort at our hospital, and a computed tomography scan showed a huge cystic mass posterior to the urinary bladder. During surgical exploration, a mass superior to the prostate in the region of the left seminal vesicle was found. Histologically, the tumor was characterized by cystically dilated or slit-like glands mixed in a densely cellular stroma with pleomorphism and resembled those of phyllodes tumor of the breast or prostate. The glandular epithelium within the tumor showed focal lipofuscin pigment and negative staining for prostate specific antigen (PSA). The stromal cells showed positive immunoreactivity for vimentin and CD34, and focal positive reactions for desmin and alpha-smooth muscle actin. Mitosis was present 0 to 1 per 10 high power fields of magnification in the stromal cells. Approximately 20% of the stromal cells were positive for progesterone receptor. The patient is alive with no evidence of disease 12 months after surgery. Mixed epithelial-stromal tumors of the seminal vesicle are extremely rare. A combination of stromal cellularity, atypia and mitosis might be used for the histological grading, and a prostatic origin might be excluded by the location of the primary lesion itself and by the failure to show PSA.     

Evaluations of bioactivity and mechanical properties of poly (epsilon-caprolactone)/silica nanocomposite following heat treatment

A composite material consisting of poly(epsilon-caprolactone) (PCL) and silica was prepared and evaluated as a bioactive bone substitute. The composite was synthesized by the co-condensation of tetraethyl orthosilicate and PCL and end-capped with triethoxysilane (Si-PCL). The as-prepared specimens were subjected to an initial heat treatment of 2 days at 60 degrees C, followed by further heat-treatments at 100 degrees C, 150 degrees C, and 200 degrees C for 24 h. The tensile mechanical properties of the heat-treated specimens were determined, and additional specimens were exposed to a simulated body fluid (SBF) for different periods of time. The SBF exposure led to the deposition of a layer of apatite crystals on the surface of the composites. It was found that increasing the second heat-treatment temperature produced an increase in tensile strength and Young's modulus of the composite but a decrease in the initial rate of apatite formation. These phenomena are explained in terms of the condensation reaction that takes place between the silanol groups in the silica and Si-PCL as the heat-treatment temperature is increased.