The potential impact of washing machines on laundry malodour generation.

A multidisciplinary approach has been adopted to investigate and identify the source of malodour in washing machines and the potential for cross-contamination of laundry. Four washing machines were olfactively graded, and the number of colony-forming units (CFUs) bacteria was determined in four specific locations. Then, samples of terry-towel and fleece were washed, without the use of detergent, in the machines, and the occurrence of malodour over a 52-h period was assessed. Analysis of the scrapings from the four locations in the two malodorous machines identified a plethora of volatile organic compounds (VOCs) by either olfactory detection or mass spectral identification post-gas chromatographic separation. In addition, microbiological analysis from the swabs from the four locations within all four washing machines was carried out. Quantitative analysis of VOCs from 66 microbiological isolates from either the washing machines or fabrics was carried out. In total, 10 VOCs were identified: dimethyl disulfide, 3-methyl-1-butanol, 2,4-dithiapentane, dimethyl trisulfide, 2-tridecanone, indole, 2-phenylethanol, isovaleric acid, isobutyric acid and 1-undecene.

Selecting for development of fluoroquinolone resistance in a Campylobacter jejuni strain 81116 in chickens using various enrofloxacin treatment protocols.

AIMS: To determine the effect of various enrofloxacin dose regimes on the colonization and selection of resistance in Campylobacter jejuni strain 81116P in experimentally colonized chickens. METHODS AND RESULTS: Two experiments were undertaken, in which 14-day-old chickens were colonized with 1 × 10(7) -1 × 10(9 ) CFU g(-1) Camp. jejuni strain 81116P and then treated with enrofloxacin at 12-500 ppm in drinking water for various times. Caecal colonization levels were determined at various time-points after start-of-treatment, and the susceptibility of recovered isolates to ciprofloxacin was monitored. Resistance was indicated by growth on agar containing 4 µg ml(-1) ciprofloxacin, MICs of 16 µg ml(-1) and the Thr86Ile mutation in gyrA. Enrofloxacin at doses of 12-250 ppm reduced Camp. jejuni colonization over the first 48-72 h after start-of-treatment. The degree of reduction in colonization was dose, but not treatment time, dependent. In all cases, maximal colonization was re-established within 4-6 days. Fluoroquinolone-resistant organisms were recoverable within 48 h of start-of-treatment; after a further 24 h all recovered isolates were resistant. In contrast, a dose of 500 ppm enrofloxacin reduced colonization to undetectable levels within 48 h, and the treated birds remained Campylobacter negative throughout the remaining experimental period. By high pressure liquid chromatography, for all doses, the maximum concentrations of enrofloxacin and ciprofloxacin in the caecal contents were detected at the point of treatment completion. Thereafter, levels declined to undetectable by 7 days post-treatment withdrawal. CONCLUSIONS: In a model using chickens maximally colonized with Camp. jejuni 81116P, treatment with enrofloxacin, at doses of 12-250 ppm in drinking water, enables the selection, and clonal expansion, of fluoroquinolone-resistant organisms. However, this is preventable by treatment with 500 ppm of enrofloxacin. SIGNIFICANCE AND IMPACT OF THE STUDY: Treatment of chickens with enrofloxacin selects for resistance in Camp. jejuni in highly pre-colonized birds. However, a dose of 500 ppm enrofloxacin prevented the selection of resistant campylobacters.

Histologic changes in Paget's disease treated with calcitonin.

In recent years the use of calcitonin in the medical treatment of Paget's disease of bone has been gaining in popularity. Seventeen patients on long term calcitonin therapy showed objective morphologic evidence of improvement in the quality of bone matrix deposition, in the trabecular organization, and in the parameters used to evaluate the rates of bone turnover. The usefulness of bone biopsy and fine detail radiography of the biopsy core in evaluating the progress of disease and the effects of therapy is discussed. It is concluded that the longer the period of therapy and follow-up, the higher the proportion of patients showing histologic evidence of improvement.

Regional deposition of inhaled hygroscopic aerosols: in vivo SPECT compared with mathematical modeling.

The regional deposition patterns of inhaled hygroscopic aerosols obtained in vivo in the studies of Phipps et al. (P. R. Phipps, I. Gonda, D. L. Bailey, P. Borham, G. Bautovich, and S. D. Anderson. Am. Rev. Respir. Dis. 139: 1516, 1989; and P. R. Phipps, I. Gonda, S. D. Anderson, D. L. Bailey, and G. Bautovich. Eur. Respir. J. 7: 1474-1482, 1994) and Chan et al. (H.-K. Chan, P. R. Phipps, I. Gonda, P. Cook, R. Fulton, I. Young, and G. Bautovich. Eur. Respir. J. 7: 1483-1489, 1994) by using single-photon-emission computerized tomography (SPECT) are compared with the regional deposition predicted by the hygroscopic lung deposition model of Finlay and Stapleton (W. H. Finlay and K. W. Stapleton. J. Aerosol Sci. 26: 655-670, 1995). Three pairs of saline aerosols are considered: isotonic with small [2.6-microns mass median aerodynamic diameter (MMAD), geometric standard deviation (GSD) 1.4] vs. large (5.5-microns MMAD, GSD 1.7) droplets; hypotonic (0.3% NaCl) vs. hypertonic (4.5% NaCl) with 3.7- to 3.8-microns MMAD (GSD 1.4), and hypotonic vs. hypertonic (3.7- to 3.8-microns MMAD, GSD 1.5-1.8) with reduced number of droplets per cubic centimeter. For each of the three pairs of aerosols, no significant difference (P > 0.05) was found between the in vivo and computational results for either the mean value or the variance of the difference in peripheral to central deposition. Thus it appears that theoretical calculations can be used to predict the pattern of lung deposition of hygroscopic aerosols in populations of normal subjects.

The humoral immune response of rainbow trout (Salmo gairdneri) immunised by various regimes and preparations of Aeromonas salmonicida antigens.

Antibody production in rainbow trout to extracellular antigens was investigated. The following antigen preparations and immunisation regimes were used: native extracellular products (ECP) in Freund's complete adjuvant (FCA), intraperitoneally (i.p.) with and without booster; formalinized ECP in FCA, i.p. with and without booster; washed, formalinized A. salmonicida cells in FCA, i.p., with booster; native ECP in saline, i.m., four weekly injections at two different doses, 45 micrograms and 6 micrograms each injection (after the protocol of Shieh, 1985). Using crossed normal rainbow trout serum, i.p., single injection (after the protocol of Sakai, 1985). Using crossed immunoelectrophoresis all antisera contained precipitating antibodies to three to five ECP components except that from fish immunised i.m. with 6 micrograms protein where antibodies were undetectable. In no case were specific antibodies to ECP protease or haemolysin detected. In a rabbit immunised with formalinized ECP in FCA under a similar regime to the rainbow trout, antibodies to at least 15 ECP components, including protease and haemolysin, were detected. The assumption of a specific immune response to the protease, at least in respect of antibody production, in recent reports of protection afforded by vaccines composed of either crude ECP or partially purified protease (Shieh, 1985) or partially purified protease inactivated by normal serum (Sakai, 1985) is not supported by the present findings.

An in vitro method for determining regional dosages delivered by jet nebulizers.

A methodology for determining the regional dosages delivered to the respiratory tract by a jet nebulizer is presented and applied to the DeVilbiss PulmoNeb disposable nebulizer delivering a 2.5 ml nebule of Ventolin (1 mg/ml salbutamol sulphate). Results are obtained both with tapping of the nebulizer, which enhances nebulizer performance, and without tapping. The nebulizer output is characterised by measuring the total mass and the mass of solids leaving the nebulizer per minute, and performing a control volume analysis of the nebulizer. Particle size distributions are determined by phased Doppler anemometry. Deposition probabilities are calculated using a semi-empirical model for the deposition of hygroscopic aerosol particles in healthy adult Caucasian males. Deposition probabilities are then converted to regional dosages using the measured nebulizer output characteristics. The regional dosages (% of initial dose in nebulizer) of Ventolin delivered to the extrathoracic, bronchial, and alveolar regions of the respiratory tract are 0.248 +/- 0.005 mg (9.9%), 0.034 +/- 0.001 mg (1.4%), and 0.071 +/- 0.002 mg (2.8%) respectively when the nebulizer was tapped during operation, and 0.184 +/- 0.005 mg (7.4%), 0.025 +/- 0.001 mg (1.0%), and 0.052 +/- 0.002 mg (2.1%) when tapping was not used. This methodology provides a well controlled and rapid means of comparing the effectiveness of different nebulizers for use in aerosol therapy.

Characteristics and comparative performance of direct culture, direct PCR and enumeration methods for detection and quantification of Campylobacter spp. in broiler caeca.

Detection and enumeration of Campylobacter spp. in broiler chicken flocks are key components of research and surveillance studies aimed at reducing Campylobacter infections in people. Direct culture of caecal contents onto selective agar is the typical method used to confirm flock colonisation. Modified charcoal cefoperazone deoxycholate agar (mCCDA) is commonly used for this method, although alternative selective media have been used. Additionally, PCR methods to detect Campylobacter DNA from caecal contents may provide a rapid alternative. However comparative performance data for these methods is limited and therefore required to ensure optimal detection methods for this sample type. In this study, 306 broiler caeca were tested for Campylobacter using direct culture on mCCDA, Skirrows and Preston agars and two real-time PCR methods, one specific for mapA/ceuE regions and another for the flaA gene region. Additionally, the suitability of spread plating and spiral plating methods for enumeration of Campylobacter and the impact of sample storage were assessed. This study confirmed modified CCDA as an optimal media for detection of Campylobacter in broiler caeca. It was significantly more sensitive than Skirrows or Preston agars. This study also demonstrated that the mapA/ceuE PCR had excellent agreement with culture on mCCDA and is a genuine alternative method. Spread plating and spiral plating methods were suitable for enumeration although spiral plating appeared more sensitive for stored samples (72 h). A 1 log reduction in viable Campylobacters was observed in stored samples, therefore storage effects should be considered for quantitative studies with broiler caeca.

Differential susceptibility of salmonid fishes to furunculosis correlates with differential serum enhancement of Aeromonas salmonicida extracellular protease activity.

Rainbow trout, Atlantic salmon and brown trout, respectively, exhibit an increasing order of susceptibility to furunculosis. We investigated if this may be due to a differential sensitivity to exotoxins or ability to inhibit the exoprotease which is required by the bacterium to digest protein for growth. Differences were slight in susceptibility to exotoxins and serum inhibition of exoprotease at high exotoxin:serum ratios. However, at low ratios brown trout serum markedly enhanced protease activity, salmon serum had little effect and rainbow trout serum maintained 50% inhibition. This implies that during the early stages of infection the potential for growth of the bacterium would be highest in brown trout and lowest in rainbow trout. Determinations of growth rates in fresh serum support this hypothesis. The enhancement of exoprotease activity by serum of susceptible species may represent an important virulence mechanism.

Carney complex: in a patient with multiple blue naevi and lentigines, suspect cardiac myxoma.

Carney complex is characterized by spotty pigmentation (blue naevi and lentigines), myxomas (cardiac, cutaneous, mammary), endocrine over-activity (Cushing's syndrome, acromegaly), testicular tumours, and schwannomas. We report a male with multiple blue naevi, lentigines, testicular large cell calcifying Sertoli-cell tumour and four cardiac myxomas. The myxomas caused two cerebrovascular accidents and a myocardial infarction. All patients with multiple blue naevi or lentigines should be investigated for the life-threatening association of cardiac myxomas.

Pachyonychia congenita tarda.

A 42-year-old man presented with painful toenails which were overcurved transversely and onycholytic. Examination revealed that all toenails, the thumbs and index fingers were similarly affected. In addition, he had a small area of leukokeratosis in the mouth, epidermal cysts of the scrotal skin and a small area of hyperkeratosis on the ulnar borders of his hands. His characteristic nail changes began in the great toenails at the age of 20 years. After renal transplantation at age 39, the other nails changed and he developed the features described above. His sister has overcurvature of the fifth toenails. A diagnosis of pachyonychia congenita tarda was made. His case is compared with 14 other reported cases of this rare syndrome.

Transient zinc deficiency in a breast-fed premature infant.

Symptomatic zinc deficiency developed in a breast-fed premature male infant of 31 weeks gestation. At 13 weeks of age he presented with diarrhoea, irritability and an eruption identical to acrodermatitis enteropathica. Breast milk zinc concentrations were low. His course was complicated by milk protein intolerance. After 7 weeks, zinc supplementation was ceased without recurrence of disease.

Giant centrifugal miliaria profunda.

A 4-month-old developed rapidly enlarging, white plaques up to several centimeters in diameter in areas where occlusive tape had been applied, almost all on the sites of venous or arterial punctures. Microscopy demonstrated the features of miliaria profunda, with sweat duct occlusion and evidence of extravasation of sweat into the dermis. This clinical entity has not been described previously, and we suggest the name giant centrifugal miliaria profunda.

IgA multiple myeloma presenting as an acquired bullous disorder.

A 63-year-old man presented with an intensely pruritic vesiculo-bullous eruption on the limbs and was subsequently found to have an IgA kappa multiple myeloma. The eruption clinically and histologically was suggestive of linear IgA disease (LAD), dermatitis herpetiformis (DH), epidermolysis bullosa acquisita (EBA), or bullous lupus erythematosus (LE), with the skin biopsy revealing subepidermal bullae and dermal papillary micro-abscesses. However, direct immunofluorescence showed a unique pattern of diffuse dermal IgA staining. Although chemotherapy produced a dramatic resolution of the lesions, which paralleled the fall in serum IgA paraprotein level, the myeloma later became progressive and the resulting paraprotein increase was accompanied by recurrence of the eruption. We propose that this patient's rash was the presenting manifestation of his multiple myeloma, and was a consequence of transudation of IgA paraprotein into the dermis.

Immunoregulation of mercuric chloride-induced autoimmunity in Brown Norway rats: a role for CD8+ T cells revealed by in vivo depletion studies.

Mercuric chloride (HgCl2) induces the production of autoantibodies to glomerular basement membrane (GBM) in the Brown Norway (BN) rat. The autoimmune response is self-limiting and thereafter the animals are resistant to rechallenge with HgCl2. Resistance can be transferred to naive animals by spleen cells from HgCl2-treated rats. A similar state of resistance can be induced with a low dose of HgCl2, insufficient in itself to induce autoimmunity. We have examined the role of CD8+ T cells in the immunoregulation of this experimental model by depleting this subset in vivo. We have also used inhibition studies in a solid-phase radioimmunoassay in an attempt to demonstrate any effect of anti-idiotypic antibodies in the spontaneous resolution of the anti-GBM antibody response. The initial induction and spontaneous resolution of anti-GBM antibodies were unaffected by depletion of CD8+ T cells. However, CD8-depleted animals were no longer resistant to rechallenge with HgCl2. Cell transfer studies showed that spleen cells from CD8-depleted animals conferred less resistance to HgCl2 than those from animals which had received control antibody. CD8 depletion also reduced the resistance induced by pretreatment with low-dose HgCl2. Studies in which peak sera were pre-incubated with post-recovery sera before testing in a solid-phase anti-GBM radioimmunoassay did not support an important role for anti-idiotypic antibodies. We conclude that CD8+ T cells play an important role in the resistance to rechallenge with HgCl2 in the BN rat, although they are not required for the induction or spontaneous resolution of the initial autoimmune response. Demonstration of the reversal of a suppressive phenomenon in vivo using an anti-CD8 monoclonal antibody is unusual.

Radiation-induced localized scleroderma in breast cancer patients.

Radiation-induced scleroderma in breast cancer patients appears to occur in approximately one out of every 500 patients. We report four cases that developed within 3 months of conservative breast surgery and postoperative radiation treatment. The reaction was contained entirely within the treatment field and demonstrated the typical features of this condition where the breast becomes erythematous, violaceous, indurated, retracted, and progressively pigmented. The breast tends to soften and become more comfortable over 1-4 years; however, significant induration, retraction and pigmentary changes remain. There appears to be no predictive factors. Radiation-induced scleroderma must be differentiated from cellulitis and recurrent breast cancer.

Vitamin A deficiency phrynoderma: due to malabsorption and inadequate diet.

We describe a patient with vitamin A deficiency phrynoderma caused by a combination of inadequate dietary intake of vitamin A and beta-carotene and malabsorption secondary to primary visceral myopathy and total colectomy.

Involvement of the small GTPases XRhoA and XRnd1 in cell adhesion and head formation in early Xenopus development.

The Rho family of small GTPases regulates a variety of cellular functions, including the dynamics of the actin cytoskeleton, cell adhesion, transcription, cell growth and membrane trafficking. We have isolated the first Xenopus homologs of the Rho-like GTPases RhoA and Rnd1 and examined their potential roles in early Xenopus development. We found that Xenopus Rnd1 (XRnd1) is expressed in tissues undergoing extensive morphogenetic changes, such as marginal zone cells involuting through the blastopore, somitogenic mesoderm during somite formation and neural crest cells. XRnd1 also causes a severe loss of cell adhesion in overexpression experiments. These data and the expression pattern suggest that XRnd1 regulates morphogenetic movements by modulating cell adhesion in early embryos. Xenopus RhoA (XRhoA) is a potential XRnd1 antagonist, since overexpression of XRhoA increases cell adhesion in the embryo and reverses the disruption of cell adhesion caused by XRnd1. In addition to the potential roles of XRnd1 and XRhoA in the regulation of cell adhesion, we find a role for XRhoA in axis formation. When coinjected with dominant-negative BMP receptor (tBR) in the ventral side of the embryo, XRhoA causes the formation of head structures resembling the phenotype seen after coinjection of wnt inhibitors with dominant-negative BMP receptor. Since dominant-negative XRhoA is able to reduce the formation of head structures, we propose that XRhoA activity is essential for head formation. Thus, XRhoA may have a dual role in the embryo by regulating cell adhesion properties and pattern formation.

Production of a DPP activity gradient in the early Drosophila embryo through the opposing actions of the SOG and TLD proteins.

During early Drosophila embryogenesis, several zygotic gene products act to establish a posttranscriptional activity gradient of the morphogen DPP. Among these molecules, Tolloid, a putative metalloprotease related to BMP-1, enhances DPP function, while SOG, an ortholog of the Xenopus organizer Chordin, inhibits DPP function. Using epistasis tests and a Xenopus secondary axis induction assay, we show that TLD negates the inhibitory effects of SOG/CHD on DPP/BMP-type ligands. In transient transfection assays, we demonstrate that TLD cleaves SOG and that cleavage is stimulated by DPP. We propose that formation of the embryonic DPP activity gradient involves the opposing effects of SOG inhibiting DPP and TLD processing SOG to release DPP from the inhibitory complex.