Cyclooxygenase expression and platelet function in healthy dogs receiving low-dose aspirin

BACKGROUND

Low-dose aspirin is used to prevent thromboembolic complications in dogs, but some animals are nonresponsive to the antiplatelet effects of aspirin ("aspirin resistance").

HYPOTHESIS/OBJECTIVES

That low-dose aspirin would inhibit platelet function, decrease thromboxane synthesis, and alter platelet cyclooxygenase (COX) expression.

ANIMALS

Twenty-four healthy dogs.

METHODS

A repeated measures study. Platelet function (PFA-100 closure time, collagen/epinephrine), platelet COX-1 and COX-2 expression, and urine 11-dehydro-thromboxane B(2) (11-dTXB(2)) were evaluated before and during aspirin administration (1 mg/kg Q24 hours PO, 10 days). Based on prolongation of closure times after aspirin administration, dogs were divided into categories according to aspirin responsiveness: responders, nonresponders, and inconsistent responders.

RESULTS

Low-dose aspirin increased closure times significantly (62% by Day 10, P < .001), with an equal distribution among aspirin responsiveness categories, 8 dogs per group. Platelet COX-1 mean fluorescent intensity (MFI) increased significantly during treatment, 13% on Day 3 (range, -29.7-136.1%) (P = .047) and 72% on Day 10 (range, -0.37-210%) (P < .001). Platelet COX-2 MFI increased significantly by 34% (range, -29.2-270%) on Day 3 (P = .003) and 74% (range, -19.7-226%) on Day 10 (P < .001). Urinary 11-dTXB(2) concentrations significantly (P = .005, P < .001) decreased at both time points. There was no difference between aspirin responsiveness and either platelet COX expression or thromboxane production.

CONCLUSIONS AND CLINICAL IMPORTANCE

Low-dose aspirin consistently inhibits platelet function in approximately one-third of healthy dogs, despite decreased thromboxane synthesis and increased platelet COX expression in most dogs. COX isoform expression before treatment did not predict aspirin resistance.

Development and validation of an instrument to measure the impact of genetic testing on self-concept in Lynch syndrome

A positive genetic test result may impact on a person's self-concept and affect quality of life. The purpose of the study was to develop a self-concept scale to measure such impact for individuals carrying mutations for a heritable colorectal cancer Lynch syndrome (LS). Two distinct phases were involved: Phase 1 generated specific colorectal self-concept candidate scale items from interviews with eight LS carriers and five genetic counselors, which were added to a previously developed self-concept scale for BRCA1/2 mutation carriers, Phase II had 115 LS carriers complete the candidate scale and a battery of validating measures. A 20-item scale was developed with two dimensions identified through factor analysis: stigma/vulnerability and bowel symptom-related anxiety. The scale showed excellent reliability (Cronbach's α = 0.93), good convergent validity by a high correlation with impact of event scale (r(102) = 0.55, p < 0.001) and Rosenberg self-esteem scale (r(108) = -0.59, p < 0.001), and a low correlation with the Fear questionnaire (r(108) = 0.37, p < 0.001). The scale's performance was stable across participant characteristics. This new scale for measuring self-concept has potential to be used as a clinical tool and as a measure for future studies.

Standardized classroom management program: Social validation and replication studies in Utah and Oregon

A comprehensive validation study was conducted of the Program for Academic Survival Skills (PASS), a consultant-based, teacher-mediated program for student classroom behavior. The study addressed questions related to: (a) brief consultant training, (b) subsequent teacher training by consultants using PASS manuals, (c) contrasts between PASS experimental teachers and students and equivalent controls on measures of teacher management skills, student classroom behavior, teacher ratings of student problem behaviors, and academic achievement, (d) reported satisfaction of participants, and (e) replication of effects across two separate school sites. Results indicated that in both sites significant effects were noted in favor of the PASS experimental group for (a) teacher approval, (b) student appropriate classroom behavior, and (c) four categories of student inappropriate behavior. Program satisfaction ratings of students, teachers, and consultants were uniformly positive, and continued use of the program was reported a year later. Discussion focused upon issues of cost-effectiveness, differential site effects, and the relationship between appropriate classroom behavior and academic achievement.

IMMUNITY IN MUMPS : VI. EXPERIMENTS ON THE VACCINATION OF HUMAN BEINGS WITH FORMOLIZED MUMPS VIRUS

The results observed after experimental inoculation of active mumps virus into 41 vaccinated and 32 unvaccinated children,-with the consent of their parents or guardians,-indicated that formol-inactivated mumps virus obtained from the parotid gland of the infected monkey and employed as a vaccine in the manner which has been described increased the resistance of about half of those to whom it was administered.

IMMUNITY IN MUMPS : V. THE CORRELATION OF THE PRESENCE OF DERMAL HYPERSENSITIVITY AND RESISTANCE TO MUMPS

The results of skin tests read at 48 hours on several hundred adults and children in which heat-inactivated mumps virus was the antigen have been presented and discussed. They can be summarized as follows:— Of 89 persons tested before the onset of mumps, 89 per cent exhibited erythematous reactions 10 mm. or less in diameter and 95 per cent, reactions 15 mm. or less in diameter. Of 40 persons tested during the first 5 days of mumps, 95 per cent exhibited reactions 10 mm. or less and 98 per cent reactions 15 mm. or less. Of 480 exposed persons the attack rate of mumps was 46 per cent among 340 with reactions 10 mm. or less and 10 per cent among 240 with reactions greater than 10 mm. The attack rate was only 2 per cent among 161 with reactions exceeding 15 mm. The attack rates in 13 skin-tested groups which were exposed to mumps tended to be inversely proportional to the incidence of reactions exceeding 10 mm. The incidence of reactions exceeding 10 mm. was approximately twice as high among 529 adults (persons 18 years or older) as it was among 306 children (persons under 18 years). Of 179 adults giving positive histories of mumps, 82 per cent exhibited skin reactions exceeding 10 mm. In certain groups the correlation between history and positive skin test was as high as 0.9. Of 132 adults giving negative histories, 58 per cent exhibited skin reactions of this magnitude. The proportion of reactions exceeding 10 mm. in a small number of children giving positive histories was 75 per cent. The proportion of reactions less than 10 mm. was 15 per cent. Of 167 adults with positive complement fixation tests, 87 per cent exhibited skin reactions exceeding 10 mm. Of 111 adults with negative complement fixation tests, 52 per cent exhibited reactions exceeding 10 mm. Of 43 children with positive complement fixation tests, the skin test reactions exceeded 10 mm. in 70 per cent. The skin reactions exceeded 10 mm. in 29 per cent of 105 children with negative complement fixation tests. In 69 of 72 individuals in whom skin reactions exceeded 10 mm., complement-fixing antibody either appeared in the blood or increased in amount within about 2 weeks after the tests were done. Such antibody responses likewise were observed in 34 of 76 individuals in whom skin reactions were 10 mm. or less. The data summarized up to this point were obtained with virus derived from the infected parotid gland of monkeys. The results of simultaneous tests in 82 individuals employing materials prepared from infected monkey parotid gland and amniotic membrane of chick embryos infected with mumps virus indicated in general that the same individual responded in a similar manner to both antigens. In many instances, however, the membrane material produced weaker reactions. Occasionally an individual failed to react at all to one of these materials but did respond to the other.

IMMUNITY IN MUMPS : IV. THE CORRELATION OF THE PRESENCE OF COMPLEMENT-FIXING ANTIBODY AND RESISTANCE TO MUMPS IN HUMAN BEINGS

Of 163 persons giving positive complement fixation tests who were exposed to mumps, 1 afterwards developed the disease; of 285 negative reactors similarly exposed, 56 afterwards came down with mumps. Of 78 individuals subjected to intimate exposure to mumps whose tests were originally negative and who failed to develop the disease, 41 per cent gave positive reactions when tested 1 month later. Seventy-seven per cent of complement fixation tests done on the sera of 565 normal adults who admitted a previous attack of mumps were positive. A similar correlation was recorded in tests on the sera of a small group of children with positive histories. Of 356 medical students admitting previous attacks, 80 per cent gave positive tests. Of 386 normal adults who denied previous attacks, 42 per cent gave positive tests; of 85 children giving negative histories, 38 per cent reacted positively. The results of complement fixation tests on the sera of 1665 normal adults (over 17 years) and 679 children (1 to 17 years) are recorded. It has been shown that 63 per cent of the adults and 57 per cent of the children had antibody in their blood which reacted with the virus of mumps. In groups in which exceptionally intense exposure was not known to have occurred in the past, the proportions of positive reactors were: adults, 61 per cent; children, 49 per cent. In contrast to these normal persons, the incidence of positive reactors among permanently institutionalized mental defectives was 38 per cent of 356 adults and 32 per cent of 475 children. In only 2 per cent of 320 normal adults and children did the titer of complement-fixing antibody reach 1-192. In no instance in which the endpoint was determined was a higher titer recorded. The results of complement fixation tests on the sera of mother and newborn infant were essentially the same in 5 instances.

Hazards of obesity--the Framingham experience

Measurements of height, weight, skinfolds and waist girth were used as indicators of general and regional obesity in the Framingham study population of 5,209 men and women. Mean values of cholesterol, blood pressure, blood glucose and uric acid increased with increasing body mass index (BMI). Weight gain was associated with increases and weight loss with decreases in these risk factors. Cigarette smoking was more prevalent in men and women with low quintile BMI. Upper quintile values of BMI, subscapular skinfolds, and waist girth were associated with increased relative risks of death from all causes, coronary heart disease (CHD) and cerebrovascular disease but relative risks for intermittent claudication were not increased. General and central obesity each made independent contributions to risk of CHD but central obesity was a better predictor in males. BMI, cholesterol, systolic blood pressure and blood glucose were significantly independent predictors of CHD. These data show that increased relative weight and central obesity are associated with elevated levels of risk factors, with increased incidence of cardiovascular disease and with increased death rates for all causes combined. Mortality rates are also increased among the leanest members of the population, especially among older men.

Congenital Corneal Anesthesia

Congenital corneal anesthesia is a rare clinical entity that poses a diagnostic dilemma, particularly in the pediatric age group. The sensory deficit may be confined to the cornea, or extend to other divisions of the trigeminal nerve. The sensory deficit may occur as an isolated abnormality, as part of a complex neurological syndrome, or it may occur in association with multiple somatic abnormalities and congenital insensitivity to pain. This condition usually presents between the ages of 8 to 12 months. Poor vision, photophobia, conjunctival injection, and corneal ulceration in the absence of pain and distress in a child should alert the clinician to the possibility of anesthetic cornea. In the early stages of presentation, punctuate keratopathy is the main feature, which may progress to non-healing persistent corneal epithelial defects. This stage may progress to acute corneal lysis and perforation. In most patients, conservative approaches such as copious lubrication, prevention of self-harm and cautious use of bandage contact lenses are effective in preventing progressive corneal damage. Tarsorrhapy is effective in promoting epithelial healing and permanent lateral tarsorraphy may prevent further development of epithelial defects. Amniotic membrane graft may be considered in order to improve epithelial healing. Corneal grafts carry a poor prognosis. Accurate initial diagnosis, evaluation, and proper management are paramount to prevent visual loss due to long-term complications of corneal anesthesia. This review of the literature outlines the problems and approaches in diagnosis, evaluation, and management of this rare condition.