Separation of bacterial capsular and lipopolysaccharides by preparative electrophoresis

Preparative gel electrophoresis was used to separate and purify extracellular, capsular and lipopolysaccharides (EPSs, CPSs, and LPSs, respectively) from crude bacterial extracts. The procedure effectively separates CPS from LPSs. In addition discreet size ranges of these various polysaccharides can be isolated. The 'rough' (R-type), 'smooth' (S-type), and 'semi-smooth' LPSs were separated from one another. In addition different size classes of 'semi-smooth', or S-type LPS, can be separated. This procedure was demonstrated for diverse bacterial species, including the soil bacteria Rhizobium fredii, and the enteric bacterial species, Salmonella enteritidis and Proteus mirabilis. In the latter case, it was also possible to separate capsular polysaccharide from its lipid-bound form.     

Management of thyroid carcinoma invading the aerodigestive tract

OBJECTIVES: To evaluate approaches to thyroid carcinoma invading the aerodigestive tract, with particular attention to well-differentiated carcinomas. STUDY DESIGN: Retrospective review of experience with thyroid carcinoma invading the aerodigestive tract over a 20-year period at a tertiary referral hospital. METHODS: The medical records of all patients with a diagnosis of thyroid cancer treated at Emory University Hospital, Atlanta, Georgia, from 1977 through 1997 were reviewed. Multiple clinical variables were analyzed including treatment, development of recurrence, and survival. Survival and time to local recurrence were determined by Kaplan-Meier analysis, and statistical comparisons were made using log-rank analysis. RESULTS: Five hundred thirty-six cases were identified; 28 patients (5.2%) were identified with invasive disease involving the aerodigestive tract. Histologic findings at the time of invasion included 15 well-differentiated (WD) carcinomas and 13 poorly differentiated (PD) carcinomas. Eight of the 28 patients (5 WD, 3 PD) underwent surgical resection of some portion of the aerodigestive tract with curative intent. Ten patients (8 WD, 2 PD) underwent incomplete resection with tumor left adjacent to aerodigestive tract structures. All patients undergoing incomplete resection developed local recurrence. Six required salvage resection, as opposed to no recurrences in WD carcinomas following complete resection (P = .01). Survival at 5 years for WD carcinomas undergoing complete resection versus initial incomplete resection was 100% versus 50%, respectively (P = .27). CONCLUSION: Review of our experience shows that complete resection of thyroid carcinoma invading the aerodigestive tract can offer prolonged palliation, improved local control, and the opportunity for cure in selected patients.     

Methyl tert-butyl ether (MTBE) contamination in private wells near gasoline stations in upstate New York

BACKGROUND: Auxiliary liver transplantation has several advantages over standard orthotopic liver transplantation. However, functional competition has been reported even in auxiliary partial orthotopic liver transplantation (APOLT). We evaluated herein the interaction in APOLT between the native liver and the graft in terms of portal blood flow and regeneration. The need for diversion of the portal blood flow to the graft was also assessed. METHODS: A total of 15 patients received APOLT from living donors. Portal blood flow to the native liver was preserved in 6 patients, and the portal vein to the native liver was preemptively transected at the time of transplantation in 9 patients. RESULTS: Of the patients with preservation of the portal blood flow to the native liver, two showed inadequate graft portal blood flow just after operation, and in the other three patients the graft portal blood flow decreased or the graft atrophied after deterioration of the graft function. In the patients with preemptive transection of the portal vein to the native liver, optimal graft portal blood flow was obtained, and the native liver, supplied only by arterial inflow, supported a small-for-size graft until the graft regenerated. The damage to the native liver was minimal. CONCLUSIONS: Functional competition may occur in APOLT with preservation of the portal blood flow to the native liver, whereas preemptive transection of the native liver portal vein is a safe procedure and effectively prevents the portal steal phenomenon.     

Equivalence of adaptive array diagonal loading and omnidirectionaljamming

Diagonal loading, where a diagonal matrix is added to the estimate of the covariance matrix, is often used in adaptive arrays to minimize the array's responsiveness to random fluctuations in the estimate of the interference environment. Poor estimates of the covariance matrix often result in high random sidelobes in the sample matrix inversion (SMI) adapted pattern. It is shown in this communication that an omnidirectional spread of uniform jammers arriving at a linear array of half-wavelength spaced elements with cosine element patterns also produces a diagonal matrix. This equivalence of form is useful in visualizing the effects of diagonal loading and understanding the resulting patterns     

Scaling up visual programming languages

The directness, immediacy, and simplicity of visual programming languages are appealing. The question is, can VPLs be effectively applied to large scale programming problems while retaining these characteristics. In scaling up, the problem is how to expand applicability without sacrificing the goals of better logic expression and understanding. From a size standpoint, scaling up refers to the programmer's ability to apply VPLs in larger programs. Such programs range from those requiring several days' work by a single programmer to programs requiring months of work, large programming teams, and large data structures. From a problem domain standpoint, scaling up refers to suitability for many kinds of problems. These range from visual application domains-such as user interface design or scientific visualization-to general purpose programming in such diverse areas as financial planning, simulations, and real time applications with explicit timing requirements. To illustrate the scaling up problem, we discuss nine major subproblems and describe emerging solutions from existing VPL systems. First, we examine representation issues, including static representation, screen real estate, and documentation. Next, we examine programming language issues-procedural abstraction, interactive visual data abstraction, type checking, persistence, and efficiency. Finally, we look at issues beyond the coding process     

Inhibition and axial deviation of limb regeneration in the newt by means of a digit implanted into the amputated limb

This research was designed to follow up the observation of Thornton and Kraemer ('51) that regressed, denervated limbs of Ambystoma larvae will not regenerate upon reinnervation if all digits on the limbs were not completely resorbed. The object of this experiment was to determine whether the presence of an apical structure, protruding past the amputation surface, would affect the regenerative process. Both forearms of adult newts were amputated midway between the elbow and the wrist. One limb served as a normal regeneration control, and in the other limb the third digit from the removed hand was implanted in place of the removed radius, so that the three distal phalangeal segments protruded past the plane of amputation. Blastema formation in the experimental limbs was delayed by several weeks as compared with control limbs. Approximately one third of the experimental limbs did not regenerate. The regenerates that did form were strongly deviated (45-90 degrees) radially from the longitudinal axis of the limb. Experimental analysis showed that the delay in regeneration is due largely to the projecting part of the digit. The radial deviation of the regenerates is not due to the digital implant, but rather to the removal of the radius. Trauma alone does not account for this phenomenon.     

Effect of interview information in altering valid impressions.

Presents the results of a study extending some of the variables of impression formation to a simulated employment interview setting. Life insurance agency managers evaluated 8 hypothetical job applicants 9 different times based on 9 different sets of information varying in favorability. 3 treatment conditions appear to have affected interviewers' evaluations: (a) valid test results (14%), (b) favorability of subjective personal history (12%), and (c) a combination of different types and amounts of information (11%). A primacy effect was found for unfavorable but not favorable information; unfavorable information had a recency effect when presented with favorable. Thus, the effect of subjective interview information in altering valid impressions is dependent on the amount, kind, and order in which it is presented. (30 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)