Junctional parenchyma: revised definition of hypertrophic column of Bertin.

The so-called hypertrophic column of Bertin is a normal variation and simply represents unresorbed polar parenchyma of one or both of the two subkidneys that fuse to form a normal kidney. It contains renal cortex, pyramids, and columns (septa) of Bertin. (Since all elements of the tissue are normal, that is, neither hypertrophic nor a displaced or embryonic rest, it is referred to as "junctional parenchyma.") When a masslike lesion is suspected at sonography or excretory urography, diagnosis of junctional parenchyma can be made with a high degree of certainty when sonography shows that the structure (a) is located between the overlapping portion of two renal sinus systems, (b) is bordered by a junctional parenchymal line and defect, (c) contains renal cortex, pyramids, and columns of Bertin, and (d) contains renal cortex that is continuous with the adjacent renal cortex of the same subkidney.     

A comparison of scintigraphy, thermography, ultrasound and phlebography in grading of clinical varicocele

Varicocele, a varicosity of the pampiniform plexus, usually on the left side, is a common urologic problem. It may be associated with symptoms of local discomfort or abnormal spermatogenesis. Internal spermatic vein phlebography is the "gold standard" investigative technique, but it is invasive. Noninvasive studies include: labeled blood-pool scintigraphy, thermography and ultrasound. Two hundred sixty-three patients were investigated with various combinations of these modalities. The degree of abnormality for each modality was graded semiquantitatively and the results compared. In addition, the results of semen analysis were correlated to imaging results. Ninety-six patients were investigated with all four tests (scintigraphy, thermography, ultrasound and phlebography). The correlation of positive phlebography to positive scintigraphy was 98%, to thermography 100% and to ultrasound 98%. The concordance (grade for grade) was 71% for scintigraphy, 68% for thermography and 62% for ultrasound. There was no obvious correlation between abnormalities of semen analysis and grading of varicocele. We conclude that the diagnostic accuracy and grading of severity by noninvasive techniques (including scintigraphy) compare very favorably with that of phlebography. Moreover, scintigraphy allows the noninvasive evaluation of reflux through the internal spermatic vein, which may be useful in planning therapy.     

Inability to demonstrate hydroxylation of tyrosine by murine melanoma "tyrosinase" (L-DOPA oxidase), using the tritiated water assay technique.

Validity of the tritiated water assay technique for tyrosine hydroxylase activity as a qualitative method was demonstrated with mushroom tyrosinase. Using this method, isolated murine melanoma "tyrosinase" (L-dopa oxidase) showed no tyrosine hydroxylase activity. This finding supports previous studies in our laboratory which used a variety of histochemical and biochemical methods. The nonenzymatic production of tritiated water caused by tritium exchange with hydrogen peroxide complicates the use of the tritiated water assay technique with crude systems, since hydrogen peroxide is generated by a variety of oxidase reactions. For this reason, previous studies using the tritiated water assay technique with crude systems are ambiguous.     

Clinical and radiographic "reankylosis" following hip surgery in ankylosing spondylitis.

Eleven patients with ankylosing spondylitis underwent reconstructive hip surgery (21 hips). In 10 of these hips multiple surgical procedures had been performed. The final procedure included total hip arthroplasties (16 hips), femoral cup arthroplasties (four hips) and an Austin-Moore prosthetic replacement (one hip). A clinical and radiographic evaluation in the postoperative period revealed a high incidence of decreased joint motion and heterotopic ossification. Clinically moderate to severe restriction of motion was noted in 12 hips, and in six of these "reankylosis" was present. Radiographically moderate to severe new bone formation was seen in 11 hips, and in nine of these "reankylosis" was suggested. An association of excessive ossification and multiple surgical procedures was evident. It would appear that when the prime indication for hip surgery in patients with ankylosing spondylitis is restricted motion, the operation may not be beneficial.     

A randomized placebo-controlled double-blind trial of lipid-lowering strategies in patients with renal insufficiency: diet modification with or without fenofibrate

BACKGROUND: Renal insufficiency is characterized by lipoprotein abnormalities including elevated triglyceride levels. PATIENTS AND METHODS: The safety and efficacy of micronized fenofibrate as a treatment for dyslipidemia in patients with progressive renal insufficiency was evaluated in a randomized, placebo-controlled double-blind study comparing fenofibrate and dietary modification to dietary modification alone. Patients were evaluated following a 3-month pre-randomization period of dietary counseling. Twenty-eight patients with moderate renal insufficiency and triglyceride levels 2.3 mmol/l or LDL/HDL ratio 5 were randomized to placebo (n = 12) or fenofibrate (n = 16) therapy. Treatment and dietary counseling continued for 6 months. RESULTS: Ten of 16 patients (63%) treated with fenofibrate achieved a 30% reduction in triglyceride levels or LDL/HDL ratio reduction < 5 compared to 2 of 17% in the placebo group (p = 0.015). Triglyceride levels were significantly reduced in the fenofibrate group (-31%) versus placebo (+1.3%, p = 0.003). In compliant patients (n = 25) there was also a significantly greater increase in HDL cholesterol levels in the fenofibrate group (+19.9%) compared to placebo (-4.7%, p = 0.001). Changes in measured creatinine clearance were not significantly different between the groups and there were no serious adverse effects of treatment. CONCLUSION: Fenofibrate therapy combined with dietary modification effectively reduced triglyceride levels in renal insufficiency patients without serious adverse effects.     

Is immediate chest radiograph necessary after central venous catheter placement in a surgical intensive care unit?

BACKGROUND: Current standard of care dictates that central venous catheter (CVC) insertion should be followed by an immediate chest radiograph to confirm appropriate position and rule out complications. We hypothesized that a subset of monitored intensive care unit patients exists that is at low risk for complications and might safely have radiographic evaluation of line placement deferred until the next scheduled radiograph. METHODS: Data regarding patient and procedural characteristics were obtained prospectively for 184 CVC placed between March 1, 1998, and June 30, 1999. Retrospective data regarding complications were obtained by chart review for an additional 174 CVC placed during the study period but for which data sheets were not completed. All procedures were followed by chest radiography. RESULTS: We documented a complication rate of 9% with the vast majority (25 of 31, 81%) of complications consisting of incorrect positioning. The number of needle passes was greater in the group suffering pneumothorax and arterial puncture than the uncomplicated group (5.6 versus 1.9, P = 0.008). "Straightforward" operator gestalt (P = 0.04) and number of needle passes <3 (P = 0.03) were factors correlating with the absence of complications. These factors had negative predictive values of 94% and 96%, respectively. CONCLUSION: Placement of CVC is safe in experienced hands. In monitored intensive care unit patients who undergo a "straightforward" procedure with <3 needle passes, chest radiograph can be safely deferred until the next scheduled examination.     

Clostridium difficile toxin: cytoskeletal changes and lactate dehydrogenase release in hepatocytes

BACKGROUND: We have found that Clostridium difficile toxins can evoke hepatocyte acute-phase protein synthesis, and that this effect is dependent on a functioning interleukin-1 (IL-1) receptor. The present study was undertaken to determine if C. difficile toxicity, as determined by actin rearrangement and lactate dehydrogenase (LDH) release, also requires a functioning IL-1 receptor. METHODS: Primary hepatocyte cultures were prepared from normal mice, knockout mice deficient in the IL-1-converting enzyme (ICE), and knockout mice deficient in the IL-1 p80 receptor. Hepatocytes were treated for 24 h with C. difficile culture extract, purified C. difficile toxin A, or purified C. difficile toxin B. The actin cytoskeleton was examined using confocal microscopy, and LDH release was measured by spectrophotometric analysis. RESULTS: C. difficile culture extract, toxin A, and toxin B induced collapse of the actin cytoskeleton in hepatocytes from normal mice. Hepatocytes from both the ICE-deficient mice and the IL-1 p80 receptor-deficient mice demonstrated similar responses to both toxins. These toxins also induced significant LDH release in a concentration-dependent fashion in the normal hepatocytes and the ICE-deficient hepatocytes. However, no significant increase in LDH release was observed in hepatocytes from IL-1 p80 receptor-deficient mice. CONCLUSIONS: C. difficile toxins induce actin cytoskeletal collapse independent of IL-1 or the IL-1 receptor. In contrast, toxin-stimulated LDH release was dependent on the presence of the IL-1 receptor. Thus, separate pathways appear to mediate toxic effects as manifested by actin rearrangement and LDH release.     

Risk of cardiovascular disease in relation to the use of combined postmenopausal hormone therapy: detection bias and resolution of discrepant findings in two Women's Health Initiative studies.

CONTEXT: In a recent analysis of data in the Women's Health Initiative (WHI) clinical trial and observational studies, the overall risks of coronary heart disease, stroke and venous thromboembolism, in postmenopausal women who used combined therapy with conjugated estrogens and medroxyprogesterone acetate, were lower in the observational data. However, the risks became more similar within similar duration categories of follow-up. In both studies, there was initial elevation, followed by a duration-dependent reduction, in the risks. The investigators suggest that the discrepancies in the overall risks may be due to weighting by short-duration exposure in the clinical trial, and long-duration exposure in the observational study. CRITIQUE: In the clinical trial, 44% of the hormone therapy recipients were unblinded, mainly because of persistent vaginal bleeding, and awareness of exposure status was therefore common; in the observational study, all exposed women were aware. When follow-up in the WHI studies commenced, extensive publicity was given to evidence to suggest that, among women who had already sustained a myocardial infarction, combined hormone therapy may not decrease the risk of a second myocardial infarct, as hypothesized, but instead increase it. From the commencement of follow-up onward, detection bias was therefore possible in both WHI studies. That possibility was further reinforced after about 3 years of follow-up, and again a year later, when the clinical trial participants were explicitly informed that supplemental hormones were associated with increased cardiovascular risks. That information was also given extensive publicity. CONCLUSIONS: Detection bias could not be ruled out in either WHI study, and there may have been systematic overestimation of the risks of cardiovascular outcomes associated with the use of combined hormone therapy. To a limited extent, an analysis of the clinical trial data according to blinding status might be informative in determining whether detection bias could have given rise to overestimation of the overall and duration-specific risks in both WHI studies. If numbers permit, comparisons within strata of severity might also be informative. If the risks were overestimated in the WHI studies, a duration-related protective effect of combined hormone therapy on the risk of coronary heart disease and stroke may have gone undetected.