Small lymph nodes of the abdomen, pelvis, and retroperitoneum: usefulness of sonographically guided biopsy

PURPOSE: To evaluate the usefulness of sonographically guided percutaneous biopsy of small lymph nodes in the abdomen, retroperitoneum, and pelvis. MATERIALS AND METHODS: From May 1995 through January 1997, 35 sonographically guided lymph node biopsies were performed in 34 patients. All biopsies were performed with a 20- (n = 18) or 22-gauge (n = 10) self-aspirating needle alone or in combination (n = 7). To determine the amount of compression achieved with the transducer, the skin-to-lesion distance on reference computed tomographic (CT) scans was compared with that on sonograms. A biopsy was considered successful if a specific benign or malignant diagnosis was rendered by the pathologist. RESULTS: Of 35 sonographically guided biopsies, 30 (86%) were successful. Diagnoses included 26 (74%) cases of carcinoma, three (9%) cases of benign reactive lymphocytosis confirmed at open biopsy, and one (3%) case of a lymph node with a positive acid-fast bacilli stain. The average lymph node diameter was 2.1 cm (range, 0.9-4.3 cm). With sonography, a mean of 2.5 needle passes (range, 1-5) were made per biopsy. Transducer compression reduced the skin-to-lesion distance from an average of 8.8 cm (at CT) to 4.5 cm. CONCLUSION: Sonographic guidance seems to provide a reasonable alternative to CT in biopsy of small abdominal, pelvic and retroperitoneal lymph nodes.     

Testing to predict outcome after transurethral resection of the prostate

PURPOSE: We assessed the ability of routine clinical tests to predict outcome following transurethral resection of the prostate. MATERIALS AND METHODS: A total of 556 men randomized into a trial of surgery versus watchful waiting was evaluated preoperatively with symptom interview, quality of life assessment, uroflowmetry, urinalysis, standard chemistry panel, post-void residual urine determination and cystoscopy. The ability to predict avoidance of postoperative complications, and improvement in quality of life and genitourinary symptoms was assessed in the 249 men randomized to undergo transurethral resection of the prostate. RESULTS: Patients with the highest symptom scores were most likely to have symptom improvement and those most bothered by the symptoms were most likely to have improvement in quality of life. No objective tests measuring physiological parameters made clinically significant contributions toward predicting these outcomes. Lower obstructive symptom scores and larger perioperative infusions of intravenous fluids were associated with a greater chance of complications. CONCLUSIONS: Symptom analysis and quality of life assessment are most useful in selecting patients for transurethral resection of the prostate. Objective diagnostic tests are of limited additional benefit.     

Adaptation of bone to physiological stimuli

The ability of bone to alter its morphology in response to local physical stimuli is predicated upon the appropriate recruitment of bone cell populations. In turn, the ability to initiate cellular recruitment is influenced by numerous local and systemic factors. In this paper, we discuss data from three ongoing projects from our laboratory that examine how physiological processes influence adaptation and growth in the skeleton. In the first study, we recorded in vivo strains to quantify the locomotion-induced distribution of two parameters closely related to bone fluid flow strain rate and strain gradients. We found that the magnitude of these parameters (and thus the implied fluid flow) varies substantially within a given cross-section, and that while strain rate magnitude increases uniformly with elevated speed, strain gradients increase focally as gait speed is increased. Secondly, we examined the influence of vascular alterations on bone adaptation by assessing bone blood flow and bone mechanical properties in an in vivo model of trauma-induced joint laxity. A strong negative correlation (r2 = 0.8) was found between increased blood flow (76%) in the primary and secondary spongiosa and decreased stiffness (-34%) following 14 weeks of joint laxity. These data suggest that blood flow and/or vascular adaptation may interact closely with bone adaptation initiated by trauma. Thirdly, we examined the effect of a systemic influence upon skeletal health. After 4 weeks old rats were fed high fat-sucrose diets for 2 yr, their bone mechanical properties were significantly reduced. These changes were primarily due to interference with normal calcium absorption. In the aggregate, these studies emphasize the complexity of bone's normal physical environment, and also illustrate the potential interactions of local and systemic factors upon the process by which bone adapts to physical stimuli.     

Recent developments in the molecular characterization of Barrett's esophagus

Barrett's esophagus, or specialized intestinal metaplasia, is a common condition associated with gastroesophageal reflux and an increased risk for adenocarcinoma of the esophagus and gastric cardia. Currently, clinical surveillance for early detection of adenocarcinoma relies on the histopathological assessment of dysplasia. In this review we present data from the published literature, and combine this with results from our own research, to address what is currently known about the environmental factors and the molecular changes thought to be important in the pathogenesis of Barrett's esophagus. The most important and well-characterized molecular changes, preceding the development of dysplasia, are alterations in the p53 and erbB-2 genes and aneuploidy. These molecular changes, as well as environmental influences, such as the quality and quantity of gastroduodenal refluxate, may result in abnormal cell proliferation which in turn promotes further genetic abnormalities and deregulation of cell growth. The identification of molecular changes, in the context of predisposing environmental factors, will enhance our understanding of the malignant progression of Barrett's esophagus leading to more effective surveillance and treatment.     

Effects of L-histidine and its structural analogues on human N-myristoyltransferase activity and importance of EEVEH amino acid sequence for enzyme activity

Myristoyl-CoA:protein N-myristoyltransferase (NMT) is an essential eukaryotic enzyme that catalyzes the cotranslational transfer of myristate to the NH2-terminal glycine residue of a number of important proteins of diverse function. Human NMT (hNMT) activity was found to be activated by L-histidine in a concentration-dependent manner. In contrast, two structural analogues of L-histidine, L-histidinol and histamine, inhibited hNMT activity in a noncompetitive manner with half-maximal inhibitions of 18 and 1.5 mM, respectively. The inhibition of hNMT activity by L-histidinol was reversed by a 2-fold molar excess of L-histidine, suggesting that L-histidine and L-histidinol were competing for a common site on NMT. Kinetic data indicated that whereas L-histidine enhanced the Vmax, both L-histidinol and histamine decreased the Vmax; none of these compounds altered the Km. Our studies suggest that L-histidine and its analogues may be interacting with His-293, involved in myristoyl-CoA transfer, rather than His-218, and implicated in the transfer of myristoyl-CoA to the peptide substrates. Site-directed mutagenesis of His-293, Val-291, and Glu-290 resulted in proteins with no measurable NMT activity. The most conserved region in the catalytic domain EEVEH (289-293) is critical for the myristoyl-CoA transfer in the NMT-catalyzed reactions. This region will be useful for the design of regulators of NMT function.     

Evaluating support services to seniors. A discussion of collaborative research

The difficulties involved in attempting to turn collaboration into partnership are revealed in this article about the relationship between research funders and researchers, specifically government funders and university researchers. Some discussion revolves around the relationships between researchers and among the researchers, practitioners, and consumers. This article also discusses collaborative research relationships by using the evaluation of a support program to seniors as an illustration. Also addressed are how the research revealed the success of the program and the frustrations encountered when government would not act on the findings.