Radiographic and arthroscopic features of third carpal bone slab fractures and their impact on racing performance following arthroscopic repair in a population of racing Thoroughbreds in the UK.

BACKGROUND: Slab fractures of the third carpal bone (C3) are a common injury of Thoroughbred racehorses. Results of arthroscopically guided repair have not been reported since the initial description of the technique in 1986. Additionally, fracture details and racing outcomes in a population of Thoroughbreds racing under UK jurisdiction have not previously been described. OBJECTIVES: To report the frequency distribution of C3 slab fractures and to determine the impact on racing performance following arthroscopically guided repair in a population of Thoroughbred racehorses. STUDY DESIGN: Retrospective case series. METHODS: Case records of Thoroughbred racehorses undergoing arthroscopically guided repair of C3 slab fractures at Newmarket Equine Hospital between 2006 and 2015 were retrieved. Radiographs and arthroscopic studies were reviewed. The effect of demography and fracture morphology on racing outcome was evaluated. RESULTS: C3 slab fractures occurred most commonly through the radial facet in a frontal plane (45/71 63.4%). Comminution was identified during arthroscopy in 42/71 (59.2%) fractures and occurred most frequently at the palmar margin of the fracture. Forty-one out of 65 horses (63.1%) raced at least once post-operatively. Females were less likely to return to racing compared to males (P<0.001). Horses that had raced before injury were more likely (OR 4.4, 95% CI 1.4-13.5, P = 0.01) to race after injury compared to horses that were unraced at the time of injury. After injury horses had a small but significant reduction in racing performance. MAIN LIMITATIONS: The series is a preselected population of Thoroughbred racehorses which referring veterinary surgeons considered potential candidates for surgical repair. CONCLUSION: Fracture configurations can be identified radiographically but is not a reliable predictor of comminution or other intra-articular lesions. Arthroscopy not only directs repair but also identifies and facilitates management of concurrent lesions. The results reported should assist in formulating appropriate prognoses for Thoroughbred horses racing in the UK.

Differential resting quantitative electroencephalographic alpha patterns in women with environmental chemical intolerance, depressives, and normals.

BACKGROUND: Previous research suggests that a subset of individuals with intolerance to low levels of environmental chemicals have increased levels of premorbid and/or comorbid psychiatric disorders such as depression, anxiety, and somatization. The purpose of this study was to evaluate the psychological profiles and quantitative electroencephalographic (qEEG) profiles at baseline of women with and without chemical intolerance (CI). METHODS: Participants were middle-aged women who reported illness from the odor of common chemicals (CI, n = 14), depressives without such intolerances (D, n = 10), and normal controls (N, n = 11). They completed a set of psychological scales and underwent two separate qEEG recording laboratory sessions spaced 1 week apart, at the same time of day for each subject. RESULTS: CI were similar to D with increased lifetime histories of physician-diagnosed depression (71% vs. 100%), Symptom Checklist 90 (revised) (SCL-90-R) somatization scores, Barsky Somatic Symptom Amplification, and perceived life stressfulness, although D had more distress than either CI or N on several other SCL-90-R subscales. CI scored significantly higher on the McLean Limbic Symptom Checklist somatic symptom subscale than did either D or N. On qEEG, CI exhibited significantly greater overall resting absolute alpha activity with eyes closed, especially at the parietal midline site (Pz), and increased (sensitized) frontal alpha from session 1 to 2, in contrast with the D and N groups. D showed right frontal asymmetry in both sessions, in comparison with CI. CONCLUSIONS: The data indicate that CI with affective distress diverge from both D without chemical intolerance and N in qEEG alpha patterns at resting baseline. Although CI descriptively resemble D with increased psychological distress, the CI's greater alpha suggests the possibility of a) central nervous system hypo-, not hyper-, activation; and/or b) an overlap with EEG alpha patterns of persons with positive family histories of alcoholism.

Illness from low levels of environmental chemicals: relevance to chronic fatigue syndrome and fibromyalgia.

This article summarizes (1) epidemiologic and clinical data on the symptoms of maladies in association with low-level chemicals in the environment, i.e., environmental chemical intolerance (CI), as it may relate to chronic fatigue syndrome (CFS) and fibromyalgia; and (2) the olfactory-limbic neural sensitization model for CI, a neurobehavioral synthesis of basic and clinical research. Severe CI is a characteristic of 20-47% of individuals with apparent CFS and/or fibromyalgia, all patients with multiple chemical sensitivity (MCS), and approximately 4-6% of the general population. In the general population, 15-30% report at least minor problems with CI. The levels of chemicals reported to trigger CI would normally be considered nontoxic or subtoxic. However, host factors--e.g., individual differences in susceptibility to neurohormonal sensitization (amplification) of endogenous responses--may contribute to generating a disabling intensity to the resultant multisystem dysfunctions in CI. One site for this amplification may be the limbic system of the brain, which receives input from the olfactory pathways and sends efferents to the hypothalamus and the mesolimbic dopaminergic [reward] pathway. Chemical, biologic, and psychological stimuli can initiate and elicit sensitization. In turn, subsequent activation of the sensitized limbic and mesolimbic pathways can then facilitate dysregulation of behavioral, autonomic, endocrine, and immune system functions. Research to date has demonstrated the initiation of neurobehavioral sensitization by volatile organic compounds and pesticides in animals, as well as sensitizability of cardiovascular parameters, beta-endorphin levels, resting EEG alpha-wave activity, and divided-attention task performance in persons with CI. The ability of multiple types of widely divergent stimuli to initiate and elicit sensitization offers a new perspective on the search for mechanisms of illness in CFS and fibromyalgia with CI.

The association of sleep-disordered breathing and sleep symptoms with quality of life in the Sleep Heart Health Study.

This study assessed the extent to which sleep-disordered breathing (SDB), difficulty initiating and maintaining sleep (DIMS), and excessive daytime sleepiness (EDS) were associated with impairment of quality of life (QoL) using the SF-36. Participants (n=5,816; mean age=63 years; 52.5% women) were enrolled in the nation-wide population-based Sleep Heart Health Study (SHHS) implemented to investigate sleep-disordered breathing as a risk factor in the development of cardiovascular disease. Each transformed SF-36 scale was analyzed independently using multiple logistic regression analysis with sleep and other potential confounding variables (e.g., age, ethnicity) included as independent variables. Men (11.6%) were significantly more likely to have SDB compared to women (5.6%), while women (42.4%) were significantly more likely to report DIMS than men (32.5%). Vitality was the sole SF-36 scale to have a linear association with the clinical categories of SDB (mild, moderate, severe SDB). However, individuals with severe SDB indicated significantly poorer QoL on several SF-36 scales. Both DIMS and EDS were strongly associated with reduced QoL even after adjusting for confounding variables for both sexes. Findings suggest 1) mild to moderate SDB is associated with reduced vitality, while severe SDB is more broadly associated with poorer QoL, 2) subjective sleep symptoms are comprehensively associated with poorer QoL, and 3) SF-36 mean score profiles for SDB and sleep symptoms are equivalent to other chronic diseases in the U.S. general population.

Individual differences in neural sensitization and the role of context in illness from low-level environmental chemical exposures.

This paper summarizes the clinical phenomenology of multiple chemical sensitivity (MCS), outlines the concepts and evidence for the olfactory-limbic, neural sensitization model for MCS, and discusses experimental design implications of the model for exposure-related research. Neural sensitization is the progressive amplification of responsivity by the passage of time between repeated, intermittent exposures. Initiation of sensitization may require single toxic or multiple subtoxic exposures, but subsequent elicitation of sensitized responses can involve low or nontoxic levels. Thus, neural sensitization could account for the ability of low levels of environmental chemicals to elicit clinically severe, adverse reactions in MCS. Different forms of sensitization include limbic kindling of seizures (compare temporal lobe epilepsy and simple partial seizures) and time-dependent sensitization of behavioral, neurochemical, immunological, and endocrinological variables. Sensitized dysfunction of the limbic and mesolimbic systems could account in part for many of the cognitive, affective, and somatic symptoms in MCS. Derealization (an alteration in perception making familiar objects or people seem unfamiliar or unreal) is a common MCS symptom and has been linked with limbic dysfunction in clinical neuroscience research. Sensitization is distinct from, but interactive with, other neurobiological learning and memory processes such as conditioning and habituation (compare adaptation or tolerance). In previous studies, hypotheses for MCS involving sensitization, conditioning, and habituation (adaptation) have often been considered in isolation from one another. To design more appropriate chemical exposure studies, it may be important to integrate the various theoretical models and empirical approaches to MCS with the larger scientific literature on individual differences in these potentially interactive phenomena.

Sensitization studies in chemically intolerant individuals: implications for individual difference research.

Chemical intolerance (CI) is an individual difference trait in which persons report feeling ill in multiple physiological systems from low levels of a wide range of chemically unrelated environmental substances. This paper discusses the neural sensitization model for progressive host amplification of polysymptomatic responses elicited by chemical exposures following an initiating event. The sensitization model accommodates hypotheses for initiating and eliciting CI in human populations that involve both environmental chemicals and physical or psychological stressors. Recent studies in this laboratory have demonstrated sensitization in individuals with CI over repeated sessions for dependent variables such as electroencephalographic (EEG) activity and diastolic blood pressure. Psychological distress variables alone do not explain these findings. Individuals with CI and/or vulnerability to sensitization share specific characteristics, for example, female gender, certain genetic background (offspring of alcohol-preferring parents), and personal preference for high sugar/ carbohydrate intake. Overall, the data suggest that the 15-30% of the general population who report heightened CI are highly sensitizable. Sensitizability may serve an adaptive, sentinel function in threatening environments with poor signal-to-noise ratios. However, as sensitization gradually shifts operating set points of physiological systems out of the normal range in response to allostatic load, this process may contribute to the development of chronic, polysymptomatic health conditions such as multiple chemical sensitivity and/or fibromyalgia. Individual response specificity and stereotypy rather than toxicant properties may determine which types of central, autonomic, and/or peripheral nervous system dysfunctions manifest at subclinical and clinical levels.

Self-reported chemical sensitivity and wartime chemical exposures in Gulf War veterans with and without decreased global health ratings.

This cross-sectional telephone survey study assessed prevalence rates of current chemical sensitivity, frequency of chemical odor intolerance, and self-reported Persian Gulf chemical exposures among 41 randomly sampled Department of Veterans Affairs outpatients who were Persian Gulf War (PGW) and PGW-era veterans. The participants were drawn from an initial random list of 100 veterans, of whom 28 PGW and 20 era veterans had correct telephone data on file. Of those contacted, 86% of PGW veterans (24/28) and 85% of era veterans (17/20) agreed to participate. Significantly more PGW veterans with poorer global health after military service reported considering themselves now "especially sensitive to certain chemicals" (86%, 12/14) than did the PGW veterans or era veterans in stable health (both comparison groups 30%, 3/10). Among PGW veterans, the subset with worse health associated with marked increases in chemical odor intolerance since their military service had a significantly higher odds ratio for exposure to multiple chemicals, notably wartime pesticides and insect repellent, than did comparison groups. The high rate of chemical sensitivity of PGW veterans with deteriorated health is almost three times that in PGW-era veterans and in elderly primary care outpatient veterans at the same Department of Veterans Affairs medical center and in community-based civilian samples (i.e., 30%). These preliminary findings suggest the need for further study of chemical sensitivity, including tests for acquired increases in neural sensitizability to multiple low-level chemicals, in ill PGW veterans.

Increased cardiopulmonary disease risk in a community-based sample with chemical odor intolerance: implications for women's health and health-care utilization.

Chemical intolerance, or reported illness from odors of common environmental chemicals (e.g., car exhaust, pesticides), is emerging as an important environmental and public health-care issue. Epidemiologic methods provide relevant heuristic devices for studies of complex disorders, such as chemical intolerance. The authors examined personal and reported parental cardiopulmonary disease prevalence rates in a community sample of chemically intolerant and control individuals. A county government (Tucson, Arizona) employee and kin subset (N = 181; 113 households) completed standard health questionnaires. Investigators determined chemical intolerance (n = 41/181) from self-reports of individuals who felt "moderately" to "severely" ill from exposure to at least three of five chemicals (i.e., car exhaust, pesticides, paint, new carpet, and perfume) on a Chemical Odor Intolerance Index. The authors chose the control group (n = 57/181) on the basis of self-reports of "never" feeling ill on the Chemical Odor Intolerance Index. The chemically intolerant group, which primarily comprised women (78% versus 51% of controls, p < .05), was significantly more likely to report-and to have sought--medical attention for heart problems, bronchitis, asthma, and pneumonia. Reports of heart problems in the chemically intolerant index cases and the occurrence of heart disease in both of their parents were significant (Fisher's p < .05). The chemically intolerant individuals were also significantly more likely to report maternal histories of chest problems (e.g., inhalant allergens, tuberculosis) than controls. The findings of the study suggested that the chemically intolerant individuals (a preponderance of whom were women [sex-related risk]) were more likely to have (a) reported cardiopulmonary problems (i.e., greater health risk); (b) actively sought medical care for these problems (i.e., increased medical utilization); and (c) reported more parental illnesses-particularly heart disease, asthma, and diabetes (i.e., genetic risk). Additional community-based studies of chemical intolerance are needed.

Effects of aerosol-vapor JP-8 jet fuel on the functional observational battery, and learning and memory in the rat.

To determine whether JP-8 jet fuel affects parameters of the Functional Observational Battery (FOB), visual discrimination, or spatial learning and memory, the authors exposed groups of male Fischer Brown Norway hybrid rats for 28 d to aerosol/vapor-delivered JP-8, or to JP-8 followed by 15 min of aerosolized substance P analogue, or to sham-confined fresh room air. Behavioral testing was accomplished with the U.S. Environmental Protection Agency's Functional Observational Battery. The authors used the Morris swim task to test visual and spatial learning and memory testing. The spatial test included examination of memory for the original target location following 15 d of JP-8 exposure, as well as a 3-d new target location learning paradigm implemented the day that followed the final day of exposure. Only JP-8 exposed animals had significant weight loss by the 2nd week of exposure compared with JP-8 with substance P and control rats; this finding compares with those of prior studies of JP-8 jet fuel. Rats exposed to JP-8 with or without substance P exhibited significantly greater rearing and less grooming behavior over time than did controls during Functional Observational Battery open-field testing. Exposed rats also swam significantly faster than controls during the new target location training and testing, thus supporting the increased activity noted during Functional Observational Battery testing. There were no significant differences between the exposed and control groups' performances during acquisition, retention, or learning of the new platform location in either the visual discrimination or spatial version of the Morris swim task. The data suggest that although visual discrimination and spatial learning and memory were not disrupted by JP-8 exposure, arousal indices and activity measures were distinctly different in these animals.

Bisphosphonates inhibit expression of p63 by oral keratinocytes.

Osteonecrosis of the jaw (ONJ), a side-effect of bisphosphonate therapy, is characterized by exposed bone that fails to heal within eight weeks. Healing time of oral epithelial wounds is decreased in the presence of amino-bisphosphonates; however, the mechanism remains unknown. We examined human tissue from individuals with ONJ and non-bisphosphonate-treated control individuals to identify changes in oral epithelium and connective tissue. Oral and intravenous bisphosphonate-treated ONJ sites had reduced numbers of basal epithelial progenitor cells, as demonstrated by a 13.8±1.1% and 31.9±5.8% reduction of p63 expression, respectively. No significant differences in proliferation rates, vessel density, or macrophage number were noted. In vitro treatment of clonal and primary oral keratinocytes with zoledronic acid (ZA) inhibited p63, and expression was rescued by the addition of mevalonate pathway intermediates. In addition, both ZA treatment and p63 shRNA knock-down impaired formation of 3D Ex Vivo Produced Oral Mucosa Equivalents (EVPOME) and closure of an in vitro scratch assay. Analysis of our data suggests that bisphosphonate treatment may delay oral epithelial healing by interfering with p63-positive progenitor cells in the basal layer of the oral epithelium in a mevalonate-pathway-dependent manner. This delay in healing may increase the likelihood of osteonecrosis developing in already-compromised bone.

A case of lisinopril-induced lithium toxicity.

We describe a patient who developed lithium toxicity when lisinopril was substituted for clonidine. Possible mechanisms of angiotensin-converting enzyme (ACE) inhibitor-induced lithium toxicity are discussed. Aggressive serum lithium concentration monitoring and a reduction in the dose of lithium is advised when using ACE inhibitors because of disturbances and shifts in fluid and electrolyte balance.

Silicone-induced human adjuvant disease?

Human adjuvant disease is an immunologically mediated disorder manifested by arthritis, arthralgias, skin lesions, malaise, pyrexia, and weight loss. Clinically, it often resembles rheumatoid arthritis and Reiter's syndrome. While scattered cases of adjuvant disease have been reported following injections with silicone fluid of unknown purity, paraffin, and petroleum jelly, no cases of adjuvant disease following silicone gel implant mammaplasty have been reported. We present such a case, discuss the pertinent biology of silicone, and review the literature describing adjuvant disease.

Flame-sprayed alumina on stainless steel for possible prosthetic application.

Various methods of roughening type 316 stainless steel substrate surfaces for flame-spraying alumina (Al2O3) were investigated and tested for the best alumina-to-metal bond strength. Best strength values were obtained by means of roughening via anodic polarization pitting of the stainless steel. Subsequent in vitro testing indicated a severe loss in bond strength following exposure to aerated Ringer's solution. It is suggested that the utilization of flame-sprayed devices has potential in orthopedic prostheses, but precautions must be observed.

Homeopathic constitutional type questionnaire correlates of conventional psychological and physical health scales: individual difference characteristics of young adults.

This study examined associations between scores for 19 different remedies on the constitutional type questionnaire (CTQ) and scores on standardized psychological and medical trait and state scales from health psychology research. Subjects were 104 young adult American college students (mean age 20 years; 67% female). Scales included the chemical intolerance index (CII) for environmental sensitivity, the NEO personality inventory, Marlowe-Crowne social desirability (MCSD) Scale for defensiveness, Harvard parental caring scale (HPCS) for perceived mother and father traits, Profile of Mood State (POMS) scale, Pennebaker symptom checklist (PSC), and a 3-item global health rating scale. The majority of CTQ constitutional type scores correlated significantly with greater NEO neuroticism, lower MCSD defensiveness, and greater psychological distress on the POMS subscales. NEO Extraversion and Openness subscales correlated with specific CTQ scores in directions consistent with clinical remedy pictures. CTQ Carcinosin differed from other remedies, showing no significant correlations with other scales. As hypothesized (a) persons high on CTQ scores for Carcinosin and low in parental caring (HPCS) had the highest symptom score; (b) those high on CTQ scores for Sulphur and low on HPCS had the poorest global health ratings; (c) individuals high on four different CTQ type scores (Carcinosin, Lachesis, Nux vomica, Sulphur) and high on environmental sensitivity (CII) exhibited the highest symptom scores. Taken together, the data offer additional validation of the CTQ and provide a foundation for studying interactions of constitutional type with both psychosocial and physicochemical environmental factors in homeopathic provers and patients.

The association of respiratory problems in a community sample with self-reported chemical intolerance.

This epidemiological study evaluated respiratory histories in those individuals reporting chemical intolerance (CI) in a community population sample. The subsample of 181 completed standard Respiratory Health Questionnaires. CI was determined from self-ratings of feeling 'moderately' to 'severely' ill from exposure to at least three of five common chemicals (paint, pesticides, car exhaust, new carpet, and perfume); the prevalence rate was 22.7%. The comparison group (CN) (31.5% of the sample) were selected from their reports of 'never' feeling ill from the same chemicals. The prevalence rate of CI in females was over twice that in males (28% vs 12.9%), a significant difference. There were no significant differences in smoking, age, or education between CI and CN. Prevalence rates for symptoms and Relative Risk Ratios (RR) indicated that the CI were significantly more likely to report chronic cough, phlegm, wheeze, chest tightness, exertional dyspnea, acute respiratory illnesses, hay fever, child respiratory trouble, and physician confirmed asthma. Several of these respiratory symptoms were significantly, though differentially, related to 'current' asthma and hay fever reports. Results suggest a potential vulnerability to and greater interference from respiratory illness for the CI, which have implications for women's health and quality of life.

Positive perceptions of parental caring are associated with reduced psychiatric and somatic symptoms.

OBJECTIVE: In a previous 35-year follow-up investigation to the Harvard Mastery of Stress Study, positive ratings of parental caring obtained in healthy male college students were found to be predictive of substantially reduced disease incidence (including cardiovascular disease, ulcers, and alcoholism) in mid-life. The present cross-sectional study examined the relationship between perceptions of parental caring, current psychiatric and somatic symptoms, and defensiveness, in a University of Arizona sample of females and males. METHOD: The Harvard Parental Caring Scale (HPCS), the SCL90R, and the Marlowe-Crowne (MC) scale (a measure of defensiveness) were administered to 398 students at the University of Arizona. RESULTS: Cronbach alphas were .83 for HPCS ratings of mothers and .88 for fathers. High HPCS ratings were associated with reduced symptoms reports in both females and males (p < .00002). Ratings of HPCS showed a small correlation with defensiveness (r = .141). The relationship between HPCS and symptoms was strongest in the least defensive subjects. CONCLUSIONS: Positive perceptions of love and caring from parents, typically the most important source of social support for children, are associated with reduced psychiatric and somatic symptoms. Defensiveness may play a protective role psychologically (but not necessarily physiologically) in reducing the conscious awareness of symptoms accompanying low perceptions of parental love and caring.

Neural sensitization model for multiple chemical sensitivity: overview of theory and empirical evidence.

This paper summarizes theory and evidence for a neural sensitization model of hyperresponsivity to low-level chemical exposures in multiple chemical sensitivity (MCS). MCS is a chronic polysymptomatic condition in which patients report illness from low levels of many different, structurally unrelated environmental chemicals (chemical intolerance, CI). Neural sensitization is the progressive host amplification of a response over time from repeated, intermittent exposures to a stimulus. Drugs, chemicals, endogenous mediators, and exogenous stressors can all initiate sensitization and can exhibit cross-sensitization between different classes of stimuli. The properties of sensitization overlap much of the clinical phenomenology of MCS. Animal studies have demonstrated sensitization to toluene, formaldehyde, and certain pesticides, as well as cross-sensitization, e.g., formaldehyde and cocaine. Controlled human studies in persons with self-reported CI have shown heightened sensitizability in the laboratory to nonspecific experimental factors and to specific chemical exposures. Useful outcome measures include spectral electroencephalography, blood pressure, heart rate, and plasma beta-endorphin. Findings implicate, in part, dopaminergic mesolimbic pathways and limbic structures. A convergence of evidence suggests that persons with MCS or with low-level CI may share some characteristics with individuals genetically vulnerable to substance abuse: (a) elevated family histories of alcohol or drug problems; (b) heightened capacity for sensitization of autonomic variables in the laboratory; (c) increased amounts of electroencephalographic alpha activity at rest and under challenge conditions over time. Sensitization is compatible with other models for MCS as well. The neural sensitization model provides a direction for further systematic human and animal research on the physiological bases of MCS and CI.