Presence/absence-sample matching by pigeons: divergent retention functions may result from the similarity of behavior during the absence sample and the retention interval.

Divergent choose-absence retention functions typically found in pigeons following presence/absence-sample matching have been attributed to the development of a single-code/default coding strategy. However, such effects may result from adventitious differential responding to the samples. In Experiment 1, retention functions were divergent only when differential sample responding could serve as the basis for comparison choice. In Experiment 2, when pecking did not occur during the retention interval, a choose-absence bias was found, but when pecking occurred during the retention interval, a choose-presence bias resulted. In Experiment 3, positive transfer was found when a stimulus associated with the absence of pecking replaced the absence sample but not when a stimulus associated with pecking replaced the presence sample. Thus, presence/absence-sample matching may not encourage the development of a single-code/default coding strategy in pigeons.

Simultaneous discrimination learning in pigeons: value of S- affects the relative value of its associated S+.

In a simple simultaneous discrimination involving a positive stimulus (S+) and a negative stimulus (S-), it has been hypothesized that positive value can transfer from the S+ to the S- (thus increasing the relative value of the S-) and also that negative value can transfer from the S- to the S+ (thus diminishing the relative value of the S+; Fersen, Wynne, Delius, & Staddon, 1991). Evidence for positive value transfer has been reported in pigeons (e.g. Zentall & Sherburne, 1994). The purpose of the present experiments was to determine, in a simultaneous discrimination, whether the S- diminishes the value of the S+ or the S- is contrasted with the S+ (thus enhancing the value of the S+). In two experiments, we found evidence for contrast, rather than value transfer, attributable to simultaneous discrimination training. Thus, not only does the S+ appear to enhance the value of the S-, but the S- appears to enhance rather than reduce the value of the S+.

Sonographic detection of echogenic fluid and correlation with culdocentesis in the evaluation of ectopic pregnancy.

OBJECTIVE: Because the presence of echogenic fluid on transvaginal sonography has been shown to correlate well with hemoperitoneum in patients with possible ectopic pregnancy, the aim of this study was to compare echogenic fluid on sonography with the results of culdocentesis in predicting hemoperitoneum. MATERIALS AND METHODS: Free fluid on transvaginal sonography and the results of culdocentesis were correlated with the presence or absence of hemoperitoneum in 46 patients at surgery. Forty ectopic pregnancies and six nonectopic pregnancies were found. Echogenic fluid was the criterion used to establish hemoperitoneum on sonography. For statistical analysis, negative and nondiagnostic culdocentesis results were combined. The sensitivity, specificity, and positive and negative predictive values of each diagnostic technique were compared. RESULTS: In 40 of 46 patients with ectopic pregnancy, the sensitivity and specificity of echogenic fluid for establishing hemoperitoneum were 100% and 100%, respectively, compared with 66% and 80%, respectively, for culdocentesis. More important, the negative predictive value of a nondiagnostic culdocentesis was 25% compared with 100% for echogenic fluid in the ectopic subgroup of patients. In two patients with incomplete abortions, sonography failed to detect small amounts of hemoperitoneum at surgery performed 4 hr and 7 days after sonography. CONCLUSION: Sonography is more sensitive than culdocentesis in the detection of hemoperitoneum. Culdocentesis is invasive, and nondiagnostic results cannot be used to exclude hemoperitoneum. Culdocentesis should play no role in the evaluation of ectopic pregnancy except in the unusual circumstance in which high-resolution sonography cannot be readily performed.

Pharmacologic management of pain and inflammation in athletes.

This article attempts to concisely present some of the scientific basis of the pharmacology of anti-inflammatory medications. The clinical use and application of anti-inflammatories is also addressed. The information is designed to assist the clinician to develop a sound approach in selecting the appropriate treatment plan for their patients.

Fatty acids from degenerating myelin lipids are conserved and reutilized for myelin synthesis during regeneration in peripheral nerve.

Following nerve crush, cholesterol from degenerating myelin is conserved and reutilized for new myelin synthesis during nerve regeneration. The possibility that other myelin lipids are salvaged and reutilized has not been investigated previously. We examined the fate of myelin phospholipids and their fatty acyl moieties following nerve crush by electron microscopic autoradiography of myelin lipids prelabeled with [3H]oleate or [2-3H]-glycerol. Both precursors were incorporated predominantly (> 90%) into phospholipids; > 85% of the [3H]-oleate was incorporated as oleate, with the remainder in longer-chain fatty acids. Before nerve crush, both labels were restricted to myelin sheaths. Following nerve crush and subsequent regeneration, over half the label from [3H]oleate, but little from [2-3H]glycerol, remained in nerve. The oleate label was present as fatty acyl moieties in phospholipids and was localized to newly formed myelin sheaths. Among the extracellular soluble lipids within the degenerating nerve, the bulk of the labeled phospholipids floated at the same density as lipoprotein particles. These data indicate that myelin phospholipids are completely hydrolyzed during nerve degeneration, that at least half the resultant free fatty acids are salvaged and reutilized for new myelin synthesis, and that these salvaged fatty acids are transported by a lipoprotein-mediated mechanism similar to that functioning in cholesterol reutilization.

The effects of dietary iron supplementation on the toxicity of piroctone olamine in the growing rat.

Weanling Charles River CD rats of both sexes were fed 300 mg/kg/day of Piroctone Olamine, an anti-bacterial agent, and were supplemented with 0, 50, 100 or 200 ppm dietary iron as FeSO4.7H2O for six weeks. However, analytical data indicated that Piroctone was degraded in the diet so that the rats received only 225 mg/kg/day. The rats given Piroctone Olamine without iron gained significantly less body weight and ate significantly less feed than controls, with the effect being more pronounced in the males. They also developed severe microcytic, hypochromic anemia. The rats supplemented with all three levels of dietary iron grew at a rate similar to controls. The rats supplemented with 50 ppm dietary iron had anemia with all of the hematological iron-associated factors being significantly depressed. The 100 ppm supplement restored all hematologic factors to normal in the females, but slight reductions remained in the males. The 200 ppm supplement of iron restored all parameters to values similar to the controls in both sexes. These results suggest that the mechanism of the toxicity of Piroctone Olamine is the prevention of dietary iron absorption by in situ chelation.

Human and rabbit eye responses to chemical insult.

Groups of eight human volunteers and eight albino rabbits, under controlled laboratory conditions, were exposed in one eye without subsequent rinsing to the same concentrations and volumes of four prototype consumer products: fabric softener, shampoo, hand soap, and laundry detergent. Dose volume was 0.10 or 0.01 ml. The dose concentrations were selected to produce moderate effects with recovery within 24 to 48 hr. Two irritation scales were employed with both human and animal subjects: the Draize scale by a technician and a medical scale used with slit lamp examination by an ophthalmologist. Eyes were examined by both graders before and after dosing at specified intervals until recovery. Mean and maximum irritation scores are presented for each grading time, method, and exposure, as are the mean hours to recovery (clearing) for each exposure. Recovery times for human eyes were consistent with those reported previously for accidental human exposures to similar materials. Correlation coefficients for time to clear, comparing human vs rabbit for each dose volume-species combination across the four test products, were 0.72, 0.1 ml-human vs 0.01 ml-rabbit; 0.66, 0.01 ml-human vs 0.01 ml-rabbit; 0.40, 0.01 ml-human vs 0.1 ml-rabbit; 0.35, 0.1 ml-human vs 0.1 ml-rabbit. Thus, recovery time obtained under conditions of the "Low-Volume" test (0.01 ml-rabbit) better correlates with human eye recovery time (either dose volume) than does recovery time under Draize test conditions (0.10 ml-rabbit).(ABSTRACT TRUNCATED AT 250 WORDS)

Dose-response assessments of Kathon biocide. (II). Threshold prophetic patch testing.

Biocidal preservative agents are important in preventing the growth of pathogenic and nonpathogenic organisms in a variety of personal care, household and industrial products. Nearly all effective, commonly used preservative materials possess skin sensitization potential. In a series of 13 prophetic human repeat insult patch tests involving a total of 1450 subjects, no skin sensitization was induced at concentrations of 10 ppm, 6 ppm or 5 ppm (1121 subjects) or at 15 ppm (200 subjects) of a new isothiazolinone preservative mixture (Kathon CG). Delayed contact hypersensitivity was induced in 1 of 84 subjects at 12.5 ppm and in 2 of 45 subjects at 20 ppm. These results add further support to the previously reported conclusion that use of this new biocide at the very low concentrations required for effective preservation of rinse-off products involves an extremely low risk of clinical dermatoses.

Dose-response assessments of Kathon biocide (I). Diagnostic use and diagnostic threshold patch testing with sensitized humans.

Nearly all effective, commercially available preservatives possess skin sensitization potential. This manuscript describes a program of diagnostic patch and practical use testing of consumer products that contained Kathon CG, a relatively new biocide. A series of threshold diagnostic patch tests demonstrated that the minimal elicitation concentration in occluded patch testing of allergic subjects considerably exceeded the concentrations of the biocide typically present in normal diluted use of the test products. Use testing further confirmed a threshold exposure for eliciting allergic reactions. It showed that even subjects who have delayed contact hypersensitivity to Kathon CG used rinse-off personal care products preserved with this agent without experiencing elicitation of these allergies.

Dose response relationships in delayed hypersensitivity to quinoline dyes.

Repeat insult patch testing of the quinoline dyes, D & C Yellow No. 10 (Acid Yellow No. 3) and D & C Yellow No. 11 (Solvent Yellow No. 33) demonstrated that concentrations as high as 1,000 ppm of the former induced no delayed contact hypersensitivity, whereas, concentrations of 20 ppm and 10 ppm of D & C Yellow No. 11 induced delayed hypersensitivity reactions in human volunteer panelists. No definitive hypersensitivity resulted from testing with 5 ppm of this dye. 2 persons who had been demonstrated to have reacted allergically to the use of a soap bar that contained D & C Yellow No. 11 did not react to the ad libitum use of a soap bar in which this dye was replaced with D & C Yellow No. 10.

Focal dermal hypoplasia: ocular manifestations in a male.

Focal dermal hypoplasia (Goltz Syndrome) is a rare congenital disorder resulting from ectodermal and mesodermal dysplasia. It involves ocular tissues in over 40% of cases. Considered to be X-linked dominant, the disorder characteristically occurs in females. This case represents, however, the ninth male affected by this disease to be reported in the literature. Ocular abnormalities included colobomatous microphthalmia, aniridia, and recurrent papillomas arising from the conjunctiva and lid margins. Both light and electron microscopic studies performed on papillomatous tissue failed to demonstrate the presence of viral particles. Prometaphase chromosome analysis performed on peripheral blood cells, and on papilloma cells grown in tissue culture, showed a normal male karyotype of 46, XY.

Filtering valve implant for neovascular glaucoma in proliferative diabetic retinopathy.

The prevention and treatment of neovascular glaucoma in diabetic patients presents a difficult clinical challenge. This report presents the pathologic findings in a juvenile onset diabetic patient who underwent panretinal photocoagulation. She subsequently developed neovascular glaucoma, was treated with the the Krupin-Denver valve implant, and received cyclocryotherapy after the filtering surgery failed to maintain a normal intraocular pressure. The pathologic findings resulting from each treatment modality are presented with emphasis on the failed intraocular valve. A fibrous ingrowth surrounded the valve, and a foreign body granulomatous response was present.

Evaluation of adverse reaction reports for a newly laundry product.

The marketing of widely used consumer products inevitably results in some reports of adverse dermatologic reactions which are tentatively attributable through medical history to the use of these products. Just as it is important for manufacturers to perform thorough premarket safety testing, it also is important for them to investigate these reported reactions to confirm the safety of the product under widespread use conditions. This report describes the results of such a follow-up investigation into 300 adverse reaction reports obtained during the first year of marketing of new laundry product. The results of diagnostic patch and prick tests, controlled reuse testing, and definitive diagnoses by physicians (mostly allergists and dermatologists) demonstrated that this product was highly unlikely to have caused the reported dermatologic conditions. Widespread distribution of free samples of the new product appeared to be largely responsible for the frequency of anecdotal association of adverse reactions to use of the product. The diagnostic follow-up program is described.

Dose response relationships in allergic contact dermatitis: glutaraldehyde-containing liquid fabric softener.

Glutaraldehyde (GTA) is an effective preservative in some consumer products. Because it is a weak cutaneous allergen at certain concentrations, studies were conducted to assess any potential hazard of adding a low level (550 ppm) of GTA to an experimental liquid fabric softener. Allergic contact dermatitis (delayed hypersensitivity) was not elicited in challenge tests of 16 GTA-sensitive subjects or in repeated insult patch tests of 706 normal human male and female subjects. The subjects were exposed (1) to the experiment formulation, (2) to the formulation with 10 times the normal level of GTA, and (3) to fabrics laundered with the normal use level or with 10 times the normal use level of these experimental formulations.