Biomedical subjects
Publications and source records attributed to J Cosgrove.
Certain effects, caused by rotating turbulent fluid flows in the presence of gravitational force, for transport of particles dispersed in fluid are suggested and quantified through kinetic or probability density function approach based macroscopic equations. These results are exact when turbulent fluctuations in fluid velocity along the particle path have Gaussian distribution.
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Prior reports have demonstrated that both parathyroid hormone-related protein (PTHrP) and the type I PTH/PTHrP receptor are necessary for the proper development of the embryonic mammary gland in mice. Using a combination of loss-of-function and gain-of-function models, we now report that PTHrP regulates a series of cell fate decisions that are central to the survival and morphogenesis of the mammary epithelium and the formation of the nipple. PTHrP is made in the epithelial cells of the mammary bud and, during embryonic mammary development, it interacts with the surrounding mesenchymal cells to induce the formation of the dense mammary mesenchyme. In response, these mammary-specific mesenchymal cells support the maintenance of mammary epithelial cell fate, trigger epithelial morphogenesis and induce the overlying epidermis to form the nipple. In the absence of PTHrP signaling, the mammary epithelial cells revert to an epidermal fate, no mammary ducts are formed and the nipple does not form. In the presence of diffuse epidermal PTHrP signaling, the ventral dermis is transformed into mammary mesenchyme and the entire ventral epidermis becomes nipple skin. These alterations in cell fate require that PTHrP be expressed during development and they require the presence of the PTH/PTHrP receptor. Finally, PTHrP signaling regulates the epidermal and mesenchymal expression of LEF1 and (&bgr;)-catenin, suggesting that these changes in cell fate involve an interaction between the PTHrP and Wnt signaling pathways.
Blue/white selection is the standard method for detecting a cloned DNA fragment. In the absence of an insert, uninterrupted expression of the vector-encoded alpha-complement of beta-galactosidase (beta-gal), results in the hydrolysis of X-gal (5-bromo-4-chloro-3-indolyl-beta-D-galactoside) and the subsequent blue staining of the host colony or bacteriophage plaque expressing the carboxyterminal portion of the beta-gal gene (lacZ). A white or clear colony or plaque indicates the presence of an insert. Because of its water insolubility, X-gal is dissolved in hazardous solvents such as dimethylformamide and then added to the medium following autoclaving. X-gal can be spread on previously plated medium, but this may result in an uneven color development. Also, incubation at 4 degrees C is frequently required for the distinction between a positive recombinant (unstained colony or plaque) and a stained negative. S-Gal (3,4-cyclohexenoesculetin-beta-D-galactopyranoside), a novel beta-gal substrate, is autoclavable and microwavable, allowing for dry-blending of the dye directly into the medium. Black S-Gal-stained colonies are visibly distinguishable from unstained colonies at an earlier time than X-gal. In addition, detection of the unstained signal over background is enhanced by 25% using S-Gal-containing medium, compared to medium containing X-gal. These characteristics offer convenience and better suitability for automated colony or plaque analyses.
BACKGROUND: Previous work has highlighted the disadvantages of propofol as a sole agent for total intravenous anaesthesia (TIVA). This randomised study investigated three combinations of propofol and alfentanil as TIVA for major thoracic surgery. METHODS: In 73 patients undergoing elective thoracic surgery, anaesthesia was conducted either with sodium thiopentone induction and inhalational maintenance (incorporating isoflurane) or with TIVA using propofol with alfentanil (by infusion at one of two rates or in incremental doses). Vital signs and recovery characteristics were recorded. RESULTS: There were no significant differences in heart rate or blood pressure between groups during either induction or maintenance. Depth of anaesthesia was controlled satisfactorily in all groups. Recovery characteristics were similar between treatment groups, although there was a trend towards earlier orientation in the group which received the highest infusion rate of alfentanil. CONCLUSION: Continuous infusions of propofol and alfentanil provide safe and reliable TIVA for major thoracic surgery. TIVA was found to be a satisfactory technique in more elderly patients than previously described. The higher of the two alfentanil infusion rates may result in a better combination of propofol and alfentanil with respect to recovery times than the lower.
The application of laparoscopy for therapy is well established in biliary tract disease, inguinal herniorrhaphy, and fundoplication. Frequently, the diagnostic capability of laparoscopy is overlooked. A review of the literature and an institution's experience in laparoscopy for the acute abdomen is presented. Therapy was completed laparoscopically in a substantial number of cases.
OBJECTIVE: The authors reviewed the results of endoscopic retrograde cholangiopancreatography (ERCP) and intraoperative cholangiography in a series of patients who underwent laparoscopic cholecystectomy. SUMMARY BACKGROUND DATA: The indications for preoperative and postoperative ERCP and intraoperative cholangiography as adjuncts to laparoscopic cholecystectomy are evolving. The debate regarding the use of selective or routine intraoperative cholangiography has intensified with the advent of laparoscopic cholecystectomy. METHODS: The authors reviewed the records of 343 consecutive patients who underwent laparoscopic cholecystectomy during a 1-year period. Historical, biochemical, and radiologic findings for the patients who underwent ERCP and intraoperative cholangiography were analyzed. RESULTS: Three hundred forty- three patients underwent laparoscopic cholecystectomy during the period reviewed. Preoperative ERCP was performed in 42 patients. Twenty-seven of these patients (64%) had common bile duct (CBD) stones, which were cleared with a sphincterotomy. Intraoperative cholangiography was performed for 101 patients (29%). Three cholangiograms had false- positive results (3%), leading to two CBD explorations, in which no CBD stones were found, and one normal ERCP. Six patients underwent postoperative ERCP, three for the removal of retained CBD stones (0.9%), all of which were cleared with a sphincterotomy. Fifteen patients had gallstone pancreatitis, six of whom had CBD stones (40%) that were cleared by ERCP. There were 33 complications (10%) and no CBD injuries. CONCLUSION: The use of routine intraoperative cholangiography is discouraged in view of its low yield and the significant rate of false positive cholangiogram results.
Wilms' tumor (nephroblastoma), a primary renal neoplasm containing primitive blastema and embryonic glomerulotubular structures, is the most common malignant tumor of the urinary tract in children. There have been about 240 cases of adult Wilms' tumor reported in the world literature, however due to some differences in histologic findings, many cases have been reclassified as rhabdoid or clear cell sarcomas, both of which are recognized as separate entities. We report a case of an adult Wilms' tumor and discuss the clinical, radiographic and histologic features of this tumor.
The charts of 1351 patients undergoing cholecystectomy at our institutions from 1985 through 1989 were reviewed retrospectively to evaluate the indications for and the success of intraoperative cholangiography. A total of 800 patients underwent intraoperative cholangiography. They were divided into two groups based on the absence (CR-) or presence (CR+) of clinical and/or operative criteria suggestive of the existence of common bile duct stones. Intraoperative cholangiography in CR- patients was of limited benefit, being negative (normal) in 95.7%, true-positive (abnormal) in 3.3%, and false-positive in 1%. False-positive intraoperative cholangiography resulted in unnecessary common bile duct explorations. Intraoperative cholangiography in CR+ patients proved useful, avoiding unnecessary common bile duct exploration in 55%. In those select CR+ patients with palpable common bile duct stones or cholangitis, little additional information was gained by the intraoperative cholangiography. We conclude that routine screening intraoperative cholangiography in CR- patients be reconsidered, as should the use of intraoperative cholangiography in CR+ patients with a palpable common bile duct stone or cholangitis. Intraoperative cholangiography in the remainder of CR+ patients proved beneficial and should be continued.
A battery of 12 neuropsychological tests were administered on two occasions to 15 chronic PCP users who reduced or eliminated use of PCP over a 4-week period. A comparison sample of 15 non-PCP drug users who did not differ in age, sex, education, and ethnic composition also were tested at the two time periods. Impairment, initially higher for PCP users, decreased significantly after reduction in use of PCP. A nonsignificant increase in impairment was found for non-PCP drug users. Analysis of each variable revealed that substantial improvement occurred on the acquisition, recall, and delayed recall scores of the Randt Memory Test. Improvement also was noted for some individuals on Trails B and Digit Symbol tests.
One hundred patients undergoing elective thoracic surgery were anesthetized with propofol as a continuous intravenous infusion. In 60 patients, nitrous oxide was used for supplementation. The technique proved satisfactory, but induction of anesthesia was associated with significant decreases in blood pressure. The use of nitrous oxide markedly reduced the propofol requirements, and prolonged the time to the first spontaneous breath during recovery. The mean infusion rate of propofol was 7.2 +/- 2.72 mg/kg/h with air-oxygen, and 5.7 +/- 1.97 mg/kg/min with nitrous oxide-oxygen (P less than 0.01). This technique seems to be a satisfactory alternative for patients primarily requiring an intravenous anesthetic during thoracic surgery.
A new anaesthetic technique that uses two catheters combined with high frequency jet ventilation for sleeve resection of the major bronchus and carina is described. The advantages and disadvantages are discussed and compared with other techniques.
This case report describes the use of high frequency jet ventilation for resection of bilateral lung bullae. Low airway pressures reduced the risk of pulmonary barotrauma. A continuous infusion of ketamine provided acceptable anaesthesia.
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Four patients had Gorlin's (or basal cell nevi) syndrome and pronounced medullated nerve fibers. The medullation is an additional ophthalmic manifestation of Gorlin's syndrome, which is autosomally dominant and noted for its variable expressivity.
The protective services system in the United States may be committing a form of institutional abuse of minority families if the professionals who work in that system are not sufficiently well versed in the unique childrearing practices of each culture in the communities the system represents. It is easy for misunderstandings to occur from an ethnocentric perspective, and these misunderstandings are unlikely to be in the minority group's favor. Although there is wide agreement that this represents a problem, there is not enough information readily available to allow protective service professionals to adopt a cross-cultural perspective in conducting their work. To discover some of the possible misunderstandings by the dominant American culture of subculture childrearing practices, this study was conducted through in-person interviews with members of six minority groups, Mexican-, Japanese-, Vietnamese-, Filipino- and Samoan-Americans and Blackfeet Indians, in three communities in conjunction with an evaluation of child abuse prevention demonstration projects. The themes of delegating responsibility to children and issues of dominance and submission emerged as areas for awareness and sensitivity on the part of child protective services.
The anaesthetic requirements for tracheal resection include a clear airway, adequate ventilation and good surgical access. Many techniques have been described, none of which is entirely satisfactory. This case reports on the use of high-frequency jet ventilation with 10Fg catheter combined with muscle relaxants and intravenous anaesthesia in a patient with tracheal stenosis.