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To characterize oculomotor components and diagnostic specificity of eye tracking abnormalities in schizophrenia, we examined a large consecutively admitted series of psychotic patients and matched controls. The most common abnormality in schizophrenic patients was low gain (slow) pursuit eye movements (47% of cases). Pursuit and saccadic eye movement abnormalities were no more severe in schizophrenic Ss than in those with affective psychoses, except that high rates of catch-up saccades were unique to schizophrenic Ss (17% of cases). These findings indicate that impaired pursuit eye movements are a major cause of eye tracking impairments in schizophrenia, that tracking dysfunctions commonly occur in affective psychoses, and that markedly high rates of catch-up saccades during eye tracking may be specific to schizophrenia.

Experimental methods and apparatus were developed to measure platelet concentration in an ultrafiltering hollow fiber with blood and ultrafiltrative flow rates that are characteristic of current hemofiltration practice. Values are presented for the adjusted local platelet concentration, which allows for the expected increase due to loss of ultrafiltrate volume. Platelet concentrations in fiber samples are of interest since ultra-filtration can create platelet polarization in a fashion similar to the concentration polarization that occurs for proteins. For many combinations of inlet flow rate, ultrafiltrative flow rate, and fiber dimension, there are significant elevations in adjusted fiber platelet concentration. The adjusted platelet concentrations of the outflow samples are nominally equal to those of the feed (reservoir) samples; thus, reaction and adhesion of platelets is not a significant source of fiber concentration. Experiments with fibers of different diameters indicate that, as expected in concentration polarization, the excess platelets are located near the wall. Data for the fiber platelet concentration depend in a complex fashion upon the inlet wall shear rate and ultrafiltrative velocity. For certain fixed ultrafiltrative velocities, a maximum fiber platelet concentration occurs at an intermediate inlet wall shear rate. The data are qualitatively explained by an extension of a published model involving diffusive, ultrafiltrative, and wall-induced fluxes of red cells and platelets.

Clindamycin therapy occasionally results in pseudomembranous colitis but more often results in a watery diarrheal syndrome which usually stops on cessation of clindamycin. This study was done to determine whether clindamycin itself might alter intestinal water, electrolyte, and glucose transport in the rat. The in vivo single-pass perfusion method was used. Perfusion with clindamycin altered intestinal water and electrolyte transport in a dose-related manner. Glucose transport was unaffected. Different segments of the intestine revealed a varying sensitivity to clindamycin: ileum greater than jejunum greater than colon. The transport defect was reversible on cessation of clindamycin perfusion. Chronic exposure of the intestine to clindamycin did not result in any alterations in water transport. The mechanism by which clindamycin causes these transport defects is unknown but did not involve the cyclic AMP or cyclic GMP systems, increased mucosal permeability, or alterations of mucosal morphology. The findings that clindamycin markedly inhibits intestinal water transport and induces net secretion in the ileum may explain the reversible watery diarrhea that many patients experience when treated with clindamycin.

The use of a contrasting line for the visual navigation of autonomous mobile robots in a factory environment is developed. Minimum and maximum linewidths are determined analytically by considering sensor geometry, field of view, and error conditions present in the system. The effects of these error conditions on the width of the line, as seen in the image plane, determines the optimal linewidth. Numerical examples using typical sensor parameters are given.

Diazolidinyl urea (Germall II) is a new preservative recommended for use in certain consumer products. Although 2 reports document the human sensitization rates of this preservative, no publications quantify its sensitization potential in controlled animal experiments. Diazolidinyl urea induced mild sensitization (grade 2) under maximization test conditions. Further, there was evidence of cross-reactions with both imidazolidinyl urea (Germall 115) and formaldehyde in diazolidinyl-urea-sensitized animals. Rechallenge of diazolidinyl-urea-sensitized animals with diazolidinyl urea 4 weeks following the primary challenge only elicited a weak response (0.5) from 1 animal out of 8.

Extracorporeal membrane oxygenation (ECMO) can support neonates with severe respiratory failure. Currently, the most common application of ECMO requires venoarterial access. Venovenous (VV) ECMO is desirable to avoid common carotid artery ligation. However, the best technique of venous access for VV ECMO is not established. Using a single cannula with a double-lumen (DLC) in the right atrium for simultaneous drainage and infusion of blood, VV ECMO provided total respiratory support for six apneic puppies for 3 h each. Mean systemic arterial oxygenation was lower with DLC VV (50 torr) compared to VA ECMO (247 torr), but a physiologic pH (mean 7.34) was maintained on DLC VV bypass. Higher mean bypass flow was required on DLC VV (124 ml/kg/min) compared to VA flow (101 ml/kg/min) because of recirculation of oxygenated blood. The position of the DLC in the right atrium needed to be closely monitored. Hemorrhage was noted in the myocardium after use of DLC VV ECMO.

Enterotoxigenic Escherichia coli cause diarrhea by elaborating two enterotoxins. The large-molecular-weight, heat-labile toxin causes intestinal secretion by stimulating cyclic adenosine 5'-monophosphate production. The mechanism by which the small-molecular-weight, heat-stable enterotoxin induces secretion is unclear. The present study tested the hypothesis that heat-stable enterotoxin induces secretion by altering intestinal cyclic nucleotide concentrations. This was studied in suckling mice by using highly purified E. coli heat-stable enterotoxin obtained from a strain pathogenic for humans. At 3 min after administration of this toxin, intestinal cyclic guanosine 5'-monophosphate (GMP) levels were increased 10-fold. Cyclic GMP levels decreased thereafter, but still were greater than control levels at 120 min. Cyclic adenosine 5'-monophosphate levels fell to one-half of control levels at 3 min and remained below control levels for 120 min. When the time course of enterotoxin-induced secretion was compared with changes in cyclic GMP levels, fluid secretion was not evident until 15 to 30 min after enterotoxin administration. Thus, the increase in intestinal cyclic GMP concentration preceded measurable fluid secretion. And finally, administration of the 8-bromo analog of cyclic GMP evoked fluid secretion, the time course of which was similar to that induced by enterotoxin. These, and other data, strongly suggest that E. coli heat-stable enterotoxin induces intestinal secretion by increasing intestinal cyclic GMP levels.

Hydra were cut so that regenerates consisting only of the central gastric region were formed. This region, which has no natural opening to the environment, is capable of osmoregulation and of removing excess fluid from the gut. The fluid is excreted through a break in the body wall created as a result of a strong contraction when the gut is distended with fluid. A normal hydra, therefore, must remove excess fluid by contracting and expelling it through its mouth.