Well-differentiated papillary mesothelioma of tunica vaginalis testis of unknown malignant potential: Sonographic appearance.

Paratesticular mesothelioma is a rare differential diagnosis in the presence of scrotal hydrocele. A 17-year-old boy presented with a 3-year history of progressive hydrocele. Sonography revealed a large left paratesticular mass within the hydrocele. Serum tumor markers were negative. Left hydrocelectomy was performed and pathological analysis of the epididymal mass revealed a well-differentiated papillary mesothelioma. We discuss the sonographic and pathological findings of this rare neoplasm.

Angiographic factors associated with haemorrhagic presentation of brain arteriovenous malformation in a Chinese paediatric population.

OBJECTIVE: To identify specific angiographic factors associated with haemorrhagic presentation of brain arteriovenous malformation in Chinese paediatric patients. DESIGN: Retrospective cross-sectional observational study. SETTING: Four locoregional tertiary neurosurgical centres in Hong Kong: Queen Elizabeth Hospital, Tuen Mun Hospital, Kwong Wah Hospital, and Pamela Youde Nethersole Eastern Hospital. PATIENTS: Patients aged 18 years or younger who underwent pretreatment digital subtraction angiography for brain arteriovenous malformation between 1 January 2005 and 31 July 2013 were included. Patients were divided into haemorrhagic and non-haemorrhagic groups based on the initial presentation. Pretreatment digital subtraction angiographies were independently reviewed by two experienced neuroradiologists. MAIN OUTCOME MEASURES: The following parameters were evaluated for their association with haemorrhagic presentation by univariate and multivariate analyses: nidus location, nidus size, nidus morphology (diffuse or compact); origin and number of arterial feeders; venous drainage; number of draining veins; presence of aneurysms, venous varices, and venous stenosis. RESULTS: A total of 67 children and adolescents (28 male, 39 female) with a mean age of 12 years were included. Of them, 52 (78%) presented with haemorrhage. Arteriovenous malformation size (P=0.004) and morphology (P=0.05) were found to be associated with haemorrhagic presentation by univariate analysis. Small arteriovenous malformation nidus size and diffuse nidal morphology were identified as independent risk factors for haemorrhage by multivariate analysis. CONCLUSION: Smaller arteriovenous malformation size and diffuse nidal morphology are angiographic factors independently associated with haemorrhagic presentation. Bleeding risk is important in determining the therapeutic approach (aggressive vs conservative) and timeframe, particularly in paediatric patients.

Paediatric vesicoureteric reflux imaging: where are we? Novel ultrasound-based voiding urosonography.

Vesicoureteric reflux is an important association of paediatric urinary tract infection. Fluoroscopic micturating cystourethrography and radionuclide cystography have been employed for detecting and grading vesicoureteric reflux. However, both modalities involve ionising radiation, which can pose significant radiation risk to growing children. They also have a lower detection rate due to intermittent fluoroscopic technique in micturating cystourethrography, and lower spatial resolution in radionuclide cystography. Therefore, newer radiation-free ultrasound-based contrast-enhanced voiding urosonography has been developed in Europe for 15 years. This article aimed to summarise the current literature and discuss the first local pilot study in our institution on detection of vesicoureteric reflux by contrast-enhanced voiding urosonography. Contrast-enhanced voiding urosonography is a valid alternative to micturating cystourethrography in assessing vesicoureteric reflux, based on its superior diagnostic performance, reliability, safety, feasibility, and radiation safety for children. Therefore, it should be incorporated in the guideline for investigating paediatric urinary tract infection.

Voiding urosonography with second-generation ultrasound contrast versus micturating cystourethrography in the diagnosis of vesicoureteric reflux.

Vesicoureteric reflux has been associated with paediatric urinary tract infection. Fluoroscopic micturating cystourethrography (MCU) has been the gold standard of diagnostic test for decades; however, it has been criticized owing to its lower detection rate and radiation dose to children. Therefore, new radiation-free reflux imaging modalities have been developed, in which ultrasound-based contrast-enhanced voiding urosonography (ceVUS) is a good example. However, ultrasonography has been considered as an operator-dependent examination. Therefore, our study aimed to examine the inter-observer agreement of this sonographic technique, which has not been evaluated before. Moreover, the second-generation ultrasound contrast SonoVue has been recently marketed, and the data on its efficacy on intravesical use in ceVUS is relatively scarce. Thus, we also aimed to investigate the diagnostic performance and safety profile of SonoVue-enhanced VUS in the diagnosis of vesicoureteric reflux. Our prospective comparative study compared the diagnostic performance of ceVUS with MCU in young children presenting with first episode of urinary tract infection. We performed sequential ceVUS and MCU examinations in 31 patients (62 pelvi-ureter units). Perfect inter-observer agreement (Cohen's kappa statistics = 1.0, p < 0.001) was achieved in ceVUS, suggesting its good reliability in reflux detection and grading. Using MCU as reference, ceVUS had 100 % sensitivity and 84 % specificity and carried higher reflux detection rate than MCU (p < 0.001). There was no complication encountered. Conclusion: Voiding urosonography is a reliable, sensitive, safe and radiation-free modality in the investigation of vesicoureteric reflux in children. It should be incorporated in the diagnostic algorithm in paediatric urinary tract infection.

Use of developmental language scales in Chinese children.

The Reynell Developmental Language Scale (RDLS) and Symbolic Play Test (SPT) have been useful language tests for assessing the language age of children. Both tests have been validated in English-speaking children. However, there have been no studies conducted for Chinese children, whether Mandarin (Northerners) or Cantonese (Southerners) is used as the main dialect. As the Chinese population is the largest ethnic group in the world, and Chinese emigration occurred to nearly all parts of the world, it is essential to test whether these language tools can be applied for this ethnic group. The objective of this research was to study whether RDLS and SPT are useful in assessing the language age of Chinese children. Both RDLS (Chinese version) and SPT are conducted for 116 Chinese (Cantonese-speaking) children, aged 13-59 months, in Hong Kong. There is a significant positive correlation of the language age using RDLS and SPT with the chronological age of Chinese children. Both RDLS and SPT can be adopted in determining the language/mental age of Chinese (Cantonese-speaking) children.

Knowledge of cardiopulmonary resuscitation among the public in Hong Kong: telephone questionnaire survey.

OBJECTIVES: To evaluate the knowledge of basic life-support and training experience in cardiopulmonary resuscitation among the public in Hong Kong and to identify areas for improvement in public education. DESIGN: Telephone interview using a structured multiple-choice questionnaire. SETTING: Random cross-section of the Hong Kong public, from mid-March to May 2002. PARTICIPANTS: Men and women aged 16 years and older selected using random telephone dialling. MAIN OUTCOME MEASURE: Overall score in the cardiopulmonary resuscitation knowledge questionnaire. RESULTS: Of the 357 participants, approximately 12% had received cardiopulmonary resuscitation training. Cardiopulmonary resuscitation knowledge in Hong Kong was poor, even among the previously trained and especially with regard to circulatory maintenance. The most common reason for not taking cardiopulmonary resuscitation training was lack of time. CONCLUSION: The degree of citizen preparedness in initiating cardiopulmonary resuscitation is very poor in Hong Kong. Intensified educational efforts and exploration of new approaches to improve this first stage in the chain of survival are warranted.

Occupational asthma due to latex in health care workers.

Immediate hypersensitivity reactions ranging from mild urticaria to life threatening anaphylaxis after exposure to natural rubber latex have been reported frequently in health care workers while occupational asthma due to latex exposure is less well studied. The results of specific challenge tests and immunological tests in four health care workers with work related respiratory and skin disorders induced by the use of latex gloves are described. Occupational asthma was confirmed in three subjects by specific challenge tests. All had a positive skin test reaction to the latex extract; specific IgE antibodies were detected in only one subject. The fourth subject had a negative specific inhalation and skin test reaction to the latex extract. Peak expiratory flow monitoring at work and away from work showed a pattern consistent with work related asthma. These findings confirm that latex is a cause of occupational asthma in health care workers.

The release of platelet-activating factor into plasma during allergen-induced bronchoconstriction.

Plasma histamine and platelet-activating factor (PAF) were measured in six subjects with mild seasonal asthma before and after allergen-induced bronchoconstriction, and in six other patients with asthma before and after methacholine-induced bronchoconstriction. A significant increase in plasma histamine and PAF levels was found in patients with mild seasonal asthma after allergen-induced bronchoconstriction but not in patients with asthma after bronchoconstriction induced by methacholine. There was a significant correlation between the baseline plasma PAF levels and the degree of bronchial hyperresponsiveness to methacholine. These findings suggests that PAF may be an important mediator in the pathogenesis of asthma and bronchial hyperresponsiveness.

Histamine and leukotrienes release in bronchoalveolar fluid during plicatic acid-induced bronchoconstriction.

Bronchoalveolar lavage (BAL) was performed before and 10 minutes after inhalation challenge with plicatic acid in five patients with red cedar asthma. There was a significant release of histamine and leukotriene E4 into the BAL fluid in all the patients after challenge. Inhalation challenge with methacholine in six patients with nonoccupational asthma and inhalation challenge with plicatic acid in two subjects without asthma did not result in the release of mediators in the BAL fluid. These studies provide direct evidence that plicatic acid-induced bronchoconstriction was accompanied by increased levels of histamine and leukotriene E4 release, whereas a nonimmunologic induction of bronchoconstriction did not induce such local mediator release. BAL may provide a useful means of studying the pathogenesis of occupational asthma caused by exposure to low-molecular-weight compounds.

A longitudinal study of the occurrence of bronchial hyperresponsiveness in western red cedar workers.

Two hundred twenty-seven workers in a western red cedar sawmill underwent methacholine bronchoprovocation testing at least 2 times during 3 surveys over a 2-yr period. At the first survey, workers completed a respiratory and occupational questionnaire, performed spirometry, gave serum for measurement of plicatic acid-specific IgE antibodies by radioallergosorbent testing, and had skin prick tests to detect atopy. Bronchial hyperresponsiveness was present initially in 18% of the workers. Approximately 15% of those with initially no hyperresponsiveness developed hyperresponsiveness during the follow-up period; 15% of those with initial hyperresponsiveness also lost it during follow-up. Development of hyperresponsiveness tended to coincide with a decrease in level of pulmonary function, whereas loss of hyperresponsiveness was associated with improvement in pulmonary function. Workers with either persistent bronchial hyperresponsiveness or with varying responsiveness had a higher prevalence of plicatic acid IgE antibodies and lower levels of initial pulmonary function than did workers with persistent nonresponsiveness. Workers with persistent hyperresponsiveness had higher initial estimated total airborne dust exposure than did other workers. Age, duration of sawmill employment, atopy, race, and cigarette smoking did not influence the occurrence of hyperresponsiveness. Levels of plicatic-acid-specific IgE antibodies did not change substantially over the 2 yr. These results indicate that immunologic sensitivity to plicatic acid and change in airway caliber are associated with the occurrence of bronchial hyperresponsiveness in cedar workers.

Grain-dust extract induced direct release of mediators from human lung tissue.

To explore the mechanisms of grain dust-induced acute bronchoconstriction, extracts of grain dust were incubated with chopped human lung fragments. The supernatants of the incubation media were examined for the presence of leukotrienes and histamine with high-performance liquid chromatographic techniques. Human lung fragments responded to the extract of grain dust by releasing histamine in a dose-dependent manner. Moreover, leukotrienes (B4, D4, and E4 were also found to be released. The action of grain dust appeared to be independent of the complement pathway or cell cytotoxicity since the lung tissue released the chemical mediators in the absence of plasma and responded to further reaction with compound 48/80 after interaction with grain dust. These data demonstrate that grain-dust extract may induce the release of mediators of anaphylaxis by a nonimmunologic process. This may explain the occurrence of acute bronchoconstriction in some of the grain workers.

A rabbit model of hypersensitivity to plicatic acid, the agent responsible for red cedar asthma.

We describe a rabbit model for the study of the immunogenicity and allergenicity of plicatic acid (PA), the small molecular weight compound in western red cedar responsible for occupational asthma in exposed workers. Specific anti-PA IgE as well as IgG antibodies could be raised, depending on the method of immunization. The sensitized rabbits reacted to antigenic challenge with PA-protein conjugates intravenously, with increases in respiratory frequency and pulmonary resistance. This animal model may be used for the further elucidation of the mechanism of occupational asthma induced by small molecular weight chemical compounds.

Plasma histamine after methacholine, allergen, and aspirin challenges.

Plasma histamine levels were measured by radio-enzymatic technique in seven patients following 10 challenges: five methacholine challenge tests, four antigen inhalation challenge tests, and one oral aspirin challenge test. Baseline plasma histamine was the same in all patients except in the aspirin-challenged patient, who had a higher baseline histamine level. There was no statistical change in the level of histamine throughout the test in either the methacholine-challenged or the antigen-challenged patients, whereas there was a marked increase in histamine levels in the aspirin challenged patient. A possible explanation is that methacholine and antigen are inhaled and therefore have primarily local effects on the lung, whereas oral aspirin has a systemic effect with consequently systemic changes in histamine which are detectable as changes in plasma level.

Plicatic acid-specific IgE and nonspecific bronchial hyperresponsiveness in western red-cedar workers.

In a cross-sectional survey of 652 workers in a western red-cedar sawmill, we obtained data on symptoms, pulmonary function, immediate skin reactivity to common allergens, nonspecific bronchial responsiveness, total IgE level, and sensitization to plicatic acid conjugated with human serum albumin as measured by RAST. Dust exposure was estimated by personal and area sampling for total dust during a work shift and cumulative exposure by duration of employment. Seven percent of the workers had an elevated RAST, and 20% had nonspecific bronchial hyperresponsiveness. Elevation in RAST was associated with bronchial hyperresponsiveness. Almost half (46%) of the workers with RAST elevation had bronchial hyperresponsiveness compared to 18% in workers with no RAST elevation. The association was unaffected by total IgE level or by limiting the analysis to workers without respiratory symptoms and was most apparent in younger workers. Bronchial hyperresponsiveness was associated with increased prevalence of respiratory symptoms as well as with lower levels of pulmonary function. The likelihood of bronchial hyperresponsiveness increased with increasing age but was unrelated to the dust-exposure concentration. RAST elevation was unrelated to employment duration or dust exposure and was not associated with an increased prevalence of symptoms or lower levels of pulmonary function independent of bronchial hyperresponsiveness. We conclude that plicatic acid-specific IgE and nonspecific bronchial hyperresponsiveness are associated in western red-cedar workers and that this association may reflect a causal connection.

Symptoms and pulmonary function in western red cedar workers related to duration of employment and dust exposure.

Measurements of total dust concentration were made in a western red cedar sawmill that employed 701 workers. Both area sampling and personal sampling of total dust were done over an 8-hr shift corresponding to job descriptions and locations to assign each worker an exposure level. A total of 652 (93%) of the workers completed a respiratory-occupational questionnaire and performed spirometry, of whom 334 were assigned an exposure level. Dust exposure ranged from undetectable to 6.0 mg/m3 with a median exposure level of 0.2 mg/m3. Only 10% of the workers with an assigned exposure level were exposed to more than 1.0 mg/m3. Work-related asthma, defined as symptoms of asthma which improved on days off work, was reported by 52 workers (8.0%) and was more prevalent after 10 or more yr of employment. Chronic cough, dyspnea, persistent wheeze, and physician-diagnosed asthma were unrelated to either work duration or exposure. Levels of forced vital capacity (FVC) and forced expiratory volume in 1 sec (FEV1.0) were lower with dust concentrations greater than 2.0 mg/m3, controlling for age and smoking; maximum mid-expiratory flow rate (FEF25-75%) and FEV1.0/FVC were unrelated to dust exposure concentration. Work-related symptoms of eye irritation were seen more commonly with exposure to dust concentrations of 3.0 mg/m3 or more. It is concluded that symptoms of work-related asthma in red cedar workers are more common after 10 yr of exposure, and that levels of pulmonary function are lower with higher wood dust exposures.

Occupational asthma caused by eastern white cedar (Thuja occidentalis) with demonstration that plicatic acid is present in this wood dust and is the causal agent.

A worker developed symptoms of work-related asthma a few weeks after starting to work in a sawmill where eastern white cedar (Thuja occidentalis) was transformed into shingles. The diagnosis of occupational asthma was confirmed by monitoring of peak expiratory flow rates and bronchial responsiveness to histamine off work and at work, and specific inhalation challenges in the laboratory that demonstrated an isolated late asthmatic reaction after exposure for 4 hours to the wood dust. Specific inhalation challenges with western red cedar (thuja plicata) for 2 hours and plicatic acid (PA) for 7 minutes also caused an isolated late asthmatic reaction. Elevated specific IgE levels to PA were present. Antiserum was produced in rabbits that were immunized with PA conjugated to human serum albumin. With this antiserum in inhibition experiments, cross-reactivity between western red cedar and eastern white cedar, both belonging to the family of arborvitae, was found. It is estimated that eastern white cedar contains approximately half the amount of PA present in western red cedar.

Lymphocyte sub-populations in patients with allergic and non-allergic asthma.

The subpopulations of peripheral blood lymphocytes were identified using monoclonal antibodies specific for T lymphocytes (T11 antibodies), B lymphocytes (B1 antibodies), helper/inducer T cells (T4 antibodies) and suppressor/cytotoxic cells (T8 antibodies). Ninety-six subjects, including twenty-five patients with allergic asthma, nineteen patients with non-allergic asthma and fifty-two controls without asthma, were studied. There was no significant difference in the lymphocyte subsets between the allergic and non-allergic asthmatics. When comparing patients with asthma as a group with the controls, a decrease in the number of T8-positive suppressor cells and therefore, an increase in the helper/suppressor cell ratio were demonstrated in the asthmatics. A relative deficiency of suppressor T cells may represent another immunological marker of bronchial asthma.

A study of serum antibody activity in workers with occupational exposure to diphenylmethane diisocyanate.

The prevalence of sensitization was studied in a group of 76 foundry workers with occupational exposure to diphenylmethane diisocyanate (MDI). Ten workers had clinical evidence of asthma, 40 had non-asthmatic respiratory symptoms, and 26 were asymptomatic. Specific IgE antibodies to MDI were found in two workers (2.6%) and specific IgG antibodies, in five workers (6.6%). The prevalence of IgE and IgG antibodies was higher in the 10 subjects with asthma than in the non-asthmatic group. The prevalence of anti-paratolyl-monoisocyanate antibodies was not significantly different from that of anti-MDI antibodies, and both haptenic determinants displayed a high degree of cross-reactivity in the RAST inhibition test. The role of humoral immunological mechanisms in MDI-induced asthma is unclear in view of the rather low prevalence of these serum antibodies in this group of workers.

Symptoms, pulmonary function, and bronchial hyperreactivity in western red cedar workers compared with those in office workers.

An epidemiologic health study was carried out on 652 cedar mill workers and a control group of 440 male office workers not exposed to air contaminants. Participants completed a medical-occupational questionnaire with trained interviewers, had allergy skin tests, performed spirometry, and had bronchial reactivity assessed by methacholine inhalation testing. After adjusting for differences in age, race, and smoking, cedar workers were found to have significantly higher prevalences of cough, phlegm, and dyspnea than did office workers. Symptoms of asthma and work-related asthma, but not persistent wheeze or doctor-diagnosed asthma, were reported in a significantly higher proportion of cedar workers than of office workers. Cedar workers also had significantly lower lung function test results than did office workers after controlling for height, age, race, and smoking. Bronchial hyperreactivity, defined by a methacholine PC20 less than 8 mg/ml, was more prevalent among cedar workers than among office workers, with the increase being limited to the nonatopic subgroup of workers. The prevalence of bronchial hyperreactivity increased with duration of employment among cedar workers but not among office workers. We conclude that exposure to western red cedar dust is harmful to the respiratory health of the workers, causing asthma and other respiratory symptoms, bronchial hyperreactivity, and lower levels of lung function.