Correlation of corneal endothelial pump site density, barrier function, and morphology in wound repair

After transcorneal freezing, physiologic function (pump and barrier) of the regenerating rabbit corneal endothelium was evaluated and compared with the morphologic differentiation that occurs during wound healing. Endothelial pump function was investigated utilizing the specific binding of tritiated ouabain to endothelial Na+/K+ ATPase (pump sites); the permeabilities of isolated de-epithelialized corneas to labeled inulin and dextran were measured to determine endothelial barrier function. Endothelial recovery after transcorneal freezing can be described as a three-stage process. Stage one is characterized by the establishment of an initial coverage of the wound by pleomorphic spindle-shaped cells which form a functional but incomplete barrier and minimal pump site density. In stage two, the cells assume a flattened configuration consisting of irregular polygons and establish nearly normal pump capacity. In stage three, a significant remodeling of the monolayer continues despite the layer's early physiologic recovery.     

Susceptibility of Pseudomonas maltophilia to antimicrobial agents, singly and in combination.

Pseudomonas maltophilia is resistant to most of the commonly used antimicrobial agents including those active against Pseudomonas aeruginosa. The susceptibility of 14 clinical isolates of P. Maltophilia to 18 antimicrobial agents was determined by broth dilution testing. All organisms were susceptible to trimethoprim-sulfamethoxazole (TMP-SMZ), minocycline, and LY127935. A total of 87 and 79% of the organisms were susceptible in vitro to colistin and chloramphenicol, respectively. With the exception of sisomicin, the organisms were resistant to the aminoglycosides. Of 21 combinations of antimicrobials examined for synergy, only the combination of TMP-SMZ with carbenicillin was consistently (86%) synergistic in vitro. Supplementation of the testing media with calcium and magnesium increased the minimal inhibitory concentrations for the aminoglycosides, the penicillins, and TMP-SMZ against P. maltophilia.     

Acute Disseminated (Non-Lipid) Reticuloendotheliosis

In several publications W allgren has dealt with problems related to storage diseases. In 1940 he advanced the idea that the so-called acute reticulo-endotheliosis bears close relationship to Schüller-Hand-Christian's disease and that these two maladies represent only different types of one and the same underlying disturbance. Since then this idea has gained wider acceptance. The eosinophilic granuloma has also become incorporated in the same syndrome. In the following paper some of the inherent problems are discussed in a clinical conference at the Vanderbilt Pediatric Clinic.     

Solitary retinal astrocytoma

The clinicopathologic features of retinal or optic disc astrocytomas are discussed based on eighteen reported cases. In addition, a new case of solitary retinal astrocytoma in a patient without other stigmata of phakomatosis is described. The tumor was prominently vascular and caused total exudative retinal detachment. It doubled in diameter over the seven months prior to enucleation, which was dictated by the occurrence of neovascular glaucoma. The astrocytic nature of the lesion was confirmed by immunohistochemical techniques (glial fibrillary acidic protein stain) and by electron microscopy.     

Usefulness of isoproterenol during atrial fibrillation in evaluation of asymptomatic Wolff-Parkinson-White pattern

The asymptomatic individual with a Wolff-Parkinson-White (WPW) pattern is considered at risk for ventricular fibrillation if a rapid ventricular response (shortest RR interval less than or equal to 250 ms) is observed during induced atrial fibrillation (AF) in the laboratory. It has been suggested that isoproterenol administration during AF may more accurately define the patient at risk. Consequently, the effect of isoproterenol on ventricular response during AF was studied in 21 asymptomatic individuals with WPW pattern to assess the potential of isoproterenol to identify patients at risk for sudden death. An electrophysiologic study that included elective induction of AF was performed. The shortest and mean RR intervals between 2 consecutive preexcited and normal QRS complexes, the average RR interval and the proportion of preexcited QRS complexes were measured in the control state and after bolus injections of isoproterenol (0.5, 1.0, 2.0 and 4.0 micrograms) during AF. Both atrioventricular nodal and accessory pathway conductions were enhanced proportional to isoproterenol dose. Isoproterenol had a greater effect on the atrioventricular node, as reflected by significantly greater changes in the shortest RR between normal complexes (339 +/- 70 vs 255 +/- 21 ms, mean +/- standard deviation, p less than 0.001) than the shortest RR between preexcited complexes (264 +/- 39 vs 219 +/- 34 ms, p less than 0.001) and a decrease in percentage of preexcited complexes (65 +/- 37 vs 50 +/- 33%, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Allergens of mammalian origin. V.

Eight commercial cat dander extracts and two pelt extracts derived from mongrel and Siamese cats were compared. Cat allergen 1 and cat albumin were measured by radial immunodiffusion. Allergenic activity was evaluated by prick test and a modified radioallergosorbent test. In the latter, the dilution of each extract that produced 50% inhibition of binding of IgE antibodies to insolubilized cat allergen 1 (RAST 1) and insolubilized cat serum (RAST 2) was determined. The total non-dialysable solid content of the extracts did not correlate with any other parameter. Cat allergen 1 content determined by radial immunodiffusion correlated with average prick test results in ten cat-sensitive subjects and with RAST 1 activity. Cat albumin content correlated weakly with RAST 2 activity but not with any other measure of allergenic activity. Absorption of each extract with the γ-globulin fraction of rabbit antiserum to cat allergen 1 significantly reduced prick test reactivity and RAST 1 activity, but not RAST 2 activity. These results indicate that cat allergen 1 is an important allergen in cat dander extracts and its measurement may be used to standardize the allergenic activity of such extracts.     

Alcohol toxicity, blood alcohol concentration and body water in young and adult rats.

Young rats, with more body water, had lower blood alcohol concentrations than did older ones at several times after various doses. The young also recovered sooner from intoxication. The age difference in recovery increased with increasing dose.