Acute renal failure in patients with acute pancreatitis

We describe five patients with acute pancreatitis in whom acute renal failure developed in the absence of hypotension. Pancreatitis was diagnosed clinically, with mean serum and urinary amylase levels of 766 +/- 197 (SE) and 2,378 +/- 572 units/100 ml, respectively. Acute renal failure developed within 24 hours after admission in all patients. It was manifested by oliguria, elevated levels of serum creatinine (mean, 6.9 +/- 1.1 mg/100 ml) and BUN (105 +/-28 mg/100 ml); a urinary sodium level of 72.0 +/- 6.6 mEq/liter; and isosmotic urine (355 +/- 31 mOsm/liter). The mean uric acid level was 18.6 +/- 1.6 mg/100 ml. Blood pressure was recorded frequently, and the lowest mean diastolic pressure was 96 +/- 6 mm Hg. The duration of the oliguric phase of acute renal failure was 8.2 +/- 1.7 days, and all patients recovered from both the acute pancreatitis and acute renal failure. In summary, acute pancreatitis, per se, can precipitate acute renal failure. It occurs early in the course of the pancreatitis, and extreme hyperuricemia is frequent finding that does not adversely affect the recovery of renal function.     

Addendum to "Volterra Systems with Random Inputs: A Formalized Approach"

A newly derived expression for the higher order crosscorrelation function of two jointly stationary Gaussian random processes is used to determine the output autocorrelation function of a Volterra system driven by a Gaussian input and to simplify a previously published expression for the output power spectral density and its derivation.     

Is hostility linked with affiliation among males and with achievement among females? A critique of Pollak and Gilligan.

Attempted to replicate and to clarify methodologically an investigation by S. Pollak and C. Gilligan (see record 1982-23594-001). Those investigators reported sex differences in violence imagery to TAT pictures depicting affiliation and achievement situations. Pollak and Gilligan concluded that men perceive danger in situations of affiliation whereas women perceive danger in situations of achievement. The present study demonstrated that Pollak and Gilligan incorrectly classified TAT cards into motivational categories, which may have resulted in incorrect inferences. In addition, their findings could not be replicated when 4 different systems for classifying TAT cards into motivational categories were used with 204 undergraduates. Other potential sources of error in their research, including a restrictive scoring scheme for hostility, unusual instructions, and failure to control for sex role in the TAT pictures, did not influence the results. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emergent textural contours: a new technique for visual monitoring in nystagmus, oculomotor dysfunction, and accommodative disorders

Emergent textural contours, the perceptual effect seen during continuous rotation of symmetrical arrays of uniform pattern elements, provide a unique source of visual feedback for eye movements and resolutional states and have potential for use as a new clinical tool. The phenomenon is produced by a combination of factors including the effects of visual persistence and differential resolution. A total of 28 subjects including 17 normals, 4 nystagmus, 4 oculomotor dysfunction, and 3 accommodative facility cases were shown an emergent textural contour with an instrument (the Goldrich Contour Rotator) for its display. Subjects were enabled to monitor their own eye movements and accommodative training. Nystagmus subjects were provided with a continuous source of visual input reflecting their ocular oscillations and a determination of the null point of nystagmus was made with the instrument.     

Multichannel Differential Group Delay Emulation and Compensation via a Phase Pulse Shaper

We developed a differential group delay (DGD) emulator which is based on a high spectral resolution phase pulse shaper. DGD generation has been demonstrated for up to four wavelength channels independently and simultaneously, with DGD accuracy of approximately 1 ps for up to 400-ps DGD range. For each channel, DGD versus frequency profiles can be arbitrarily programmed to user specifications. Multichannel DGD compensation has also been demonstrated using the same setup.     

Performance of Nonlinear Receivers in Asynchronous Spectral-Phase-Encoding Optical CDMA Systems

Because of limits on the speed of the photodetector, a nonlinear thresholder is needed at the receiver of a spectral-phase-encoding optical code-division multiple-access system to discriminate between the correctly decoded short pulse and the low-intensity interference. The two most common nonlinear receivers based on second harmonic generation and self-phase modulation effects are analyzed in this paper. Mathematical models are provided, and analytical results are obtained to estimate the receivers' performances. Numerical simulations are carried out for both receivers with different system parameters. Both m-sequences and random binary codes are examined for spreading. The results provide a profile of how these nonlinear receivers perform with various system settings. It is found that, when an m-sequence is used as the spreading code, the encoded signal does not obey Gaussian statistics, and the system performs better than an equivalent system using a random code.     

Biomimetic Concealing of PLGA Microspheres in a 3D Scaffold to Prevent Macrophage Uptake

Scaffolds functionalized with delivery systems for the release of growth factors is a robust strategy to enhance tissue regeneration. However, after implantation, macrophages infiltrate the scaffold, eventually initiating the degradation and clearance of the delivery systems. Herein, it is hypothesized that fully embedding the poly(d,l ‐lactide‐co‐glycolide acid) microspheres (MS) in a highly structured collagen‐based scaffold (concealing) can prevent their detection, preserving the integrity of the payload. Confocal laser microscopy reveals that non‐embedded MS are easily internalized; when concealed, J774 and bone marrow‐derived macrophages (BMDM) cannot detect them. This is further demonstrated by flow cytometry, as a tenfold decrease is found in the number of MS engulfed by the cells, suggesting that collagen can cloak the MS. This correlates with the amount of nitric oxide and tumor necrosis factor‐α produced by J774 and BMDM in response to the concealed MS, comparable to that found for non‐functionalized collagen scaffolds. Finally, the release kinetics of a reporter protein is preserved in the presence of macrophages, only when MS are concealed. The data provide detailed strategies for fabricating three dimensional (3D) biomimetic scaffolds able to conceal delivery systems and preserve the therapeutic molecules for release.