Streptococcal infection in dogs: a retrospective study of 393 cases.

Streptococcus spp are opportunistic pathogens that normally reside in the upper respiratory, intestinal, lower urinary, and genital tracts but can cause localized infection or septicemia in dogs of all ages. A retrospective study of streptococcal infection in 393 dogs was conducted to identify the species of Streptococcus isolated, determine demographics of affected dogs, and characterize the disease processes associated with infection. The major streptococcal species isolated were S canis (88 cases, 22.4%), S dysgalactiae ssp equisimilis (13, 3.3%), and S equi ssp zooepidemicus (4, 1.0%). Sex was not a risk factor (P > .30). Fetuses and neonates were more likely to have streptococcal infection than were other age groups (P < .001). Streptococcal septicemia was considered an important cause of abortion and neonatal death and was isolated from all samples submitted for aerobic culture from dogs in that age group. There was a seasonal trend, with dogs more likely to have streptococcal infection in summer months. In dogs for which a disease process was identified, streptococcal infection was associated with dermatitis (29 dogs), pneumonia (24 dogs), adult septicemia (13 dogs), and fetal/neonatal septicemia leading to abortion or neonatal death (16 dogs). Identification of other clinically significant bacterial, viral, fungal, and parasitic organisms was common (267 of 393 dogs, 68%), especially in dogs with dermatitis or pneumonia. Infection with Streptococcus spp should be considered in the differential diagnosis in cases of abortion, septicemia, dermatitis, and pneumonia in dogs. Clinical significance of isolation of streptococcal organisms should be interpreted in context of clinical signs and pathologic findings.

Dust-free bedrooms in the treatment of asthmatic children with house dust or house dust mite allergy: a controlled trial.

Twenty asthmatic children with prick tests positive for house dust or house dust mites were allocated to two groups that were matched for severity. One group was provided with zippered vinyl covers for pillows, mattresses, and box springs, and instructions for making the bedroom as easy to keep clean as a hospital ward; the other group was not. At the end of a 1-month study period, there was a marked and statistically significant difference in symptoms and signs of asthma between the two groups. Those with a dust-free bedroom had fewer days on which wheezing was observed, medication was given, or an abnormally low peak expiratory flow rate was recorded. Bronchial tolerance to aerosolized histamine significantly improved in the group whose bedrooms had been modified. A dust-free bedroom diminishes bronchial irritability and is a practical and effective method for decreasing asthma in children with house dust or house dust mite allergy.

Bronchial hyperresponsiveness in asthmatic children. Correlation with macrophages and eosinophils in broncholavage fluid.

Bronchial responsiveness assessed by histamine bronchial challenge testing in 22 children with chronic stable asthma was compared with the number of inflammatory cells per milliliter of broncholavage fluid obtained by fiberoptic bronchoscopy. Hyperresponsiveness was closely correlated with increased counts of eosinophils and macrophages and with the ratio of eosinophils to macrophages. There was no correlation of neutrophil or lymphocyte counts with bronchial hyperresponsiveness and none of the cell types was correlated with airway obstruction. Our findings support the hypotheses that macrophages may be important in the development of bronchial hyperresponsiveness in children with asthma and that they may modulate bronchial responsiveness both directly and by recruitment of eosinophils.

Correlation of cutaneous hypersensitivity with lymphocytic response to Candida albicans.

The relationship between delayed cutaneous hypersensitivity to Candida albicans and in-vitro lymphocytic proliferative response using a highly sensitive micro-technic was studied in 26 healthy adult subjects and six children with chronic mucocutaneous candidiasis. The maximum in-vitro lymphocytic proliferative response in adult subjects with cutaneous hypersensitivity, 18.94 +/- 4.16 (SE), was significantly greater than that in those without cutaneous reactions, 2.49 +/- 0.45 (SE) (P less than 0.005). A close correlation was found between cutaneous hypersensitivity (mean diameter of induration at 48 hours) and in-vitro lymphocytic proliferative response (r = 0.73, P less than 0.001). A cutaneous reaction of 5 mm or more of induration after injection of 0.1 ml of 1:100 Candida albicans extract corresponded to an in-vitro lymphocytic proliferative index of 5 or more (P less than 0.005), which supports the previously empiric use of 5 mm of induration as an indicator of intact cellular immunity in clinical practice. In the children with chronic mucocutaneous candidiasis, no consistent relationship between cutaneous hypersensitivity and lymphocytic proliferative response was found. Administration of Levamisole resulted in increased lymphocytic proliferation in vitro, and the development of cutaneous hypersensitivity, suggesting potentiation of cellular immune function.

Breast-feeding and environmental tobacco smoke exposure.

BACKGROUND: Exposure to environmental tobacco smoke is associated with adverse effects in infants and children. OBJECTIVE: To explore whether an increase in urinary cotinine fumarate level is caused by ingested nicotine and cotinine in breast-feeding infants. METHODS: We studied newborns at risk for developing asthma and allergies based on a strong family history. We measured urinary cotinine levels in the infants as a measure of environmental tobacco smoke exposure and cotinine levels in the breast milk of breast-feeding mothers. RESULTS: Of 507 infants, urinary cotinine levels during the first 2 weeks of life were significantly increased in infants whose mothers smoked. Breast-fed infants had higher cotinine levels than non-breast-fed infants, but this was statistically significant (P<.05) only if mothers smoked. Urinary cotinine levels were 5 times higher in breast-fed infants whose mothers smoked than in those whose mothers smoked but did not breast-feed. CONCLUSIONS: Mothers should be encouraged to not smoke, and parents must be advised of the potential respiratory and systemic risks of environmental tobacco smoke exposure to their child, including the potential for future addiction to smoking.

Quantified dermal activity data from a four-child pilot field study.

Thirty-three hours of videotape collected in a 1993 pilot study were quantified, via a video translation software application, to obtain left and right hand activity data of four children of farmworkers. Reported here are the children's contact duration and frequency for each object in their environment, duration spent in each location and activity exertion level, and frequency distributions of object contact durations. The pilot study provided valuable information for evaluating and improving videotaping and videotape translation methodologies as a means of gathering activity information that can be used to refine dermal exposure estimates. Although a larger database of children's videotaped activities for different ages and populations is needed before generalizations can be made, the data presented here are the most detailed information to date for children's micro-level dermal activities.

Quantifying videotaped activity patterns: video translation software and training methodologies.

Questionnaires and diaries, the current methods of human activity data collection, do not accurately capture the detail necessary to quantify exposure incurred through the dermal and non-dietary ingestion routes. Stanford University's Environmental Engineering and Science Program has developed methodologies and software (VideoTraq) for training video translators, determining inter-observer reliability, and translating videotaped micro-activity patterns into computer text files. VideoTraq output files contain duration, in seconds, for each combination of location, activity, and object contacted corresponding to the sequential micro-activities of a videotaped subject's contact boundary (e.g., left hand, right hand, mouth). Such output allows for detailed analyses of micro-activity data, including contact frequency and duration. When coupled with environmental concentrations, these data will allow for more accurate exposure assessments, particularly for the dermal and non-dietary ingestion exposure routes.

A body-worn gait analysis system for evaluating hemiplegic gait.

This paper describes a system for measuring the temporal parameters of hemiplegic gait. This system uses shoe insoles with sensors, acting as switches, placed under the heel, head of the first metatarsal, head of the fifth metatarsal and the big toe. This system is able to monitor gait for up to 10 min and can be used by the patient over any surface. Parameters for evaluating hemiplegic gait are defined, including scuffing during swing and the degree of inversion during stance.

Persisting airway obstruction in asymptomatic children with asthma with normal peak expiratory flow rates.

Twice-daily symptom scores and peak expiratory flow readings were compared with spirometric values (FEV1 and forced expiratory flow rate between 25% and 75% of FVC [FEF 25-75]) measured at 2-week intervals in assessing airway obstruction in 20 children with asthma studied during 16 weeks. Of 56 2-week periods during which symptoms were absent, peak flow was decreased in 30 (54%), FEV1 in 20 (36%), and FEF 25-75 in 37 periods (66%). Peak flow readings were normal in 13 of 70 periods (16%) in which FEV1 was decreased, and in 33 of 113 periods (29%), in which FEF 25-75 was decreased. Of 25 periods in which symptoms were absent and peak flow was normal, 19 (76%) were associated with decreased FEF 25-75. The results confirm previous studies that indicate peak flow readings are a useful addition to symptom diaries. More importantly, they demonstrate that airway obstruction may be present in a large proportion of asymptomatic children with asthma who have normal peak flow rates and suggest that frequent assessment of FEF 25-75 is required, as well as daily monitoring of symptoms and peak flow both in trials of drug therapy and for more optimal assessment of the effectiveness of therapy in clinical practice.

Prolonged impairment of cellular immunity in children with intrauterine growth retardation.

Cellular immunity was studied in 17 newborn infants, in eight children aged 1 to 5 years with intrauterine growth retardation, and in age-matched control subjects. At birth T and B peripheral blood lymphocytes were decreased, and delayed cutaneous hypersensitivity to phytohemagglutinin was diminished. In vitro PHA-induced lymphocyte proliferation was similar to that in control subjects but was greater than in healthy adults. In later childhood the numbers of T lymphocytes were normal, but their proliferative capacity was significantly reduced and cutaneous hypersensitivity was minimal or absent. Prolonged impairment of cellular immunity in these children may explain their increased susceptibility to infection and inadequate response to immunization, and predispose to the development of allergic, autoimmune, and neoplastic disease.

Food allergy.

Adverse clinical reactions to food associated with disturbed immunologic function (food allergy) affect 1-3% of the population and vary from life-threatening to a minor inconvenience. They must be differentiated from reactions caused by toxins, pharmacologic agents, enzyme deficiences and non-specific release of inflammatory mediator substances. Enteric absorption of food protein antigens which may occur despite an array of gastrointestinal protective mechanisms normally induces both a protective immune response and immunologic tolerance. Quantitative changes in absorption related to deficient protective mechanisms or excessive antigen load may contribute to the development of an allergic immune response and explain the greater incidence of food allergy in infants and children. Important factors include immunologic immaturity, enhanced macromolecular mucosal transport, intrauterine and neonatal malnutrition, breast feeding and infection. Double-blind food challenge tests remain as the most definitive diagnostic yardstick but carefully standardized skin tests may be helpful if interpreted in the context of the clinical history. Despite the association of food allergy with food antigen specific IgE hypersensitivity, immune complex formation and lymphocyte sensitization the pathophysiological changes which result in symptoms remain obscure. Recent advances have clarified many aspects of our knowledge of food allergy but inevitably have raised many more questions for future study.

Predictive value of skin prick tests and radioallergosorbent tests for clinical allergy to dogs and cats.

The predictive value and post-test probability of disease were compared for skin prick tests and radioallergosorbent tests (RASTs) in 168 children suspected of clinical allergy to dogs and cats. The skin tests included negative and positive (histamine) controls. The results of RASTs with the same allergen extracts were expressed in relation to the results with allergen-specific pooled reference serum. All the tests were performed blind. The predictive values of positive test results were comparable and low (53% to 76%), whereas the predictive values of negative test results were comparable and high (88% to 95%). The post-test probability of clinical allergy to dog or cat allergen, based on the prevalence rates in the referral population (15.1% and 22.5% respectively), increased to between 46% and 67% for positive test results and decreased to between 4% and 8% for negative results, which suggests that the primary role of skin prick tests and RASTs is in eliminating the diagnosis of clinical allergy.

Cellular immunity and nutrition in refractory disseminated blastomycosis.

In a previously healthy 13-year-old girl with disseminated blastomycosis, immunodeficiency was considered because of lymphopenia and the slow response of her lung disease to therapy with amphotericin B. Cellular immunity was found to be profoundly impaired, with absent delayed cutaneous hypersensitivity to several common antigens, a decreased count of thymus-dependent lymphocytes in the peripheral blood and a greatly diminished in-vitro proliferative response of lymphocytes to phytohemagglutinin (PHA). Humoral immunity was intact. Two additional types of therapy were assessed: subcutaneous injection of transfer factor was associated with an unsustained increase in lymphocyte counts and a positive cutaneous response to PHA but no clinical change; parenteral alimentation to ensure an adequate energy intake was associated with rapid clinical improvement, the development of delayed hypersensitivity to four additional antigens, and the return of lymphocyte counts and proliferative response to normal. These findings suggest that increased energy intake rather than transfer factor therapy was responsible for the child's recovery, and they emphasize the importance of adequate nutrition in the maintenance of intact cellular immunity.

Serotonin metabolism in cystic fibrosis.

The average blood serotonin level of 67 children with cystic fibrosis was found to be about twice that of age-matched normal children. There was no corresponding increase in the urinary excretion of 5-hydroxyindoleacetic acid (5-HIAA). Children with cystic fibrosis were well able to metabolize serotonin taken by mouth. No significant correlations were found between the blood serotonin level and the platelet count, height, weight, skinfold thickness, and pulmonary function test, 5 out of 44 patients had raised serum IgE levels, and their mean blood serotonin was higher than in those with normal IgE levels. No explanation for this emerged. Comparable findings (raised blood serotonin normal platelet count, normal urinary 5-HIAA) have been reported only in severe mental retardation. Further study of this phenomenon is warranted because (a) a raised blood serotonin level is sufficiently characteristic of cystic fibrosis to explore its use in diagnosis, and (b) it may help to explain the pathogenesis of cystic fibrosis and (c) the metabolism and function of serotonin.