Clubroot (Plasmodiophora brassicae Woronin): an agricultural and biological challenge worldwide

Clubroot disease and the causal microbe Plasmodiophora brassicae offer abundant challenges to agriculturists and biological scientists. This microbe is well fitted for the environments which it inhabits. Plasmodiophora brassicae exists in soil as microscopic well protected resting spores and then grows actively and reproduces while shielded inside the roots of host plants. The pathogen is active outside the host for only short periods. Consequently, scientific studies are made challenging by the biological context of the host and pathogen and the technology required to investigate and understand that relationship. Controlling clubroot disease is a challenge for farmers, crop consultants and plant pathology practitioners because of the limited options which are available. Full symptom expression happens solely in members of the Brassicaceae family. Currently, only a few genes expressing strong resistance to P. brassicae are known and readily available. Agrochemical control is similarly limited by difficulties in molecule formulation which combines efficacy with environmental acceptability. Manipulation of husbandry encouraging improvements in soil structure, texture, nutrient composition and moisture content can reduce populations of P. brassicae. Integrating such strategies with rotation and crop management will reduce but not eliminate this disease. There are indications that forms of biological competition may be mobilised as additions to integrated control strategies. The aim of this review is to chart key themes in the development of scientific biological understanding of this host-pathogen relationship by offering signposts to grapple with clubroot disease which devastates crops and their profitability. Particular attention is given to the link between soil and nutrient chemistry and activity of this microbe.

Chikungunya In Brazil: An Emerging Challenge.

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Self-disclosure of HIV diagnosis to sexual partners by heterosexual and bisexual men: a challenge for HIV/AIDS care and prevention

This study investigated the disclosure of HIV-positive serostatus to sexual partners by heterosexual and bisexual men, selected in centers for HIV/AIDS care. In 250 interviews, we investigated disclosure of serostatus to partners, correlating disclosure to characteristics of relationships. The focus group further explored barriers to maintenance/establishment of partnerships and their association with disclosure and condom use. Fear of rejection led to isolation and distress, thus hindering disclosure to current and new partners. Disclosure requires trust and was more frequent to steady partners, to partners who were HIV-positive themselves, to female partners, and by heterosexuals, occurring less frequently with commercial sex workers. Most interviewees reported consistent condom use. Unprotected sex was more frequent with seropositive partners. Suggestions to enhance comprehensive care for HIV-positive men included stigma management, group activities, and human rights-based approaches involving professional education in care for sexual health, disclosure, and care of "persons living with HIV".

Deconstructing sport history: The postmodern challenge

The crisis in the historical profession today is both conceptual and political, both methodological and practical. To the crises of the decline of great narrative history for the popular audience, the multiculturalist challenge to Eurocentric history, and the loss of faith in grand themes of progress and liberation that provided moral and political guidance through history’s lessons, must be added the crisis created by the implications of literary and rhetorical theory for the very practice of history itself.

Challenge or opportunity: can regional training hospitals capitalise on the impending influx of interns?

To the Editor: The increase in medical graduates expected over the next decade presents a huge challenge to the many stakeholders involved in providing their prevocational and vocational medical training. 1 Increased numbers will add significantly to the teaching and supervision workload for registrars and consultants, while specialist training and access to advanced training positions may be compromised. However, this predicament may also provide opportunities for innovation in the way internships are delivered. Although facing these same challenges, regional and rural hospitals could use this situation to enhance their workforce by creating opportunities for interns and junior doctors to acquire valuable experience in non-metropolitan settings. We surveyed a representative sample (n = 147; 52% of total cohort) of Year 3 Bachelor of Medicine and Bachelor of Surgery students at the University of Queensland about their perceptions and expectations of their impending internship and the importance of its location (ie, urban/metropolitan versus regional/rural teaching hospitals) to their future training and career plans. Most students (n = 127; 86%) reported a high degree of contemplation about their internship choice. Issues relating to career progression and support ranked highest in their expectations. Most perceived internships in urban/metropolitan hospitals as more beneficial to their future career prospects compared with regional/rural hospitals, but, interestingly, felt that they would have more patient responsibility and greater contact with and supervision by senior staff in a regional setting (Box). Regional and rural hospitals should try to harness these positive perceptions and act to address any real or perceived shortcomings in order to enhance their future workforce.2 They could look to establish partnerships with rural clinical schools3 to enhance recruitment of interns as early as Year 3. To maximise competitiveness with their urban counterparts, regional and rural hospitals need to offer innovative training and career progression pathways to junior doctors, to combat the perception that internships in urban hospitals are more beneficial to future career prospects. Partnerships between hospitals, medical schools and vocational colleges, with input from postgraduate medical councils, should provide vertical integration4 in the important period between student and doctor. Work is underway to more closely evaluate and compare the intern experience across regional/rural and urban/metropolitan hospitals, and track student experiences and career choices longitudinally. This information may benefit teaching hospitals and help identify the optimal combination of resources necessary to provide quality teaching and a clear career pathway for the expected influx of new interns.

Challenge of reducing drug-related deaths

The public-health attention given to deaths caused by illicit drug use in general, and by drug overdose in particular, should be commensurate with their contribution to premature death. For too long these deaths have been regarded as an unavoidable hazard of illicit drug use, their neglect abetted by the implicit view that the lives of illicit drug users are less deserving of being saved than those of others. In its report published this week,1 the UK Advisory Council on the Misuse of Drugs (ACMD) has rejected these implicit assumptions. Its view is that “drug-related deaths can, will and must in the near future be radically reduced in number”. It points out that the effort that society expends on preventing premature deaths “should apply no less to drug misusers than it does to other classes of people”.1

Oral-Nasal-Ocular Cleft: The Greatest Challenge Among the Rare Clefts

Introduction: Number 3 cleft or oral-nasal-ocular cleft is a well-known entity that was described by Morian over a century ago. This malformation is a paranasal-medial orbitomaxillary cleft running across the lacrimal segment of the lower eyelid and over the lacrimal groove. The Tessier number 3 naso-ocular cleft represents one of the most difficult and challenging malformations to correct for the reconstructive surgeon. We have conducted a retrospective analysis of our series consisting of 21 cases. Objective: The objective was to review the functional outcome and aesthetic results of the different techniques applied for each case. Materials and Methods: From 1997 to 2007, 21 patients with a Tessier number 3 cleft were treated in our craniofacial units. The clinical findings, tomographic studies, and surgical procedures were reviewed and analyzed. We have discussed our protocol of the treatment. Results: We have treated facial malformation in 2 craniofacial centers. Fourteen patients were evaluated in the first year of their life, with an average age at presentation of 3 years. Twelve patients were female, and 9 were male; 6 patients had amniotic bands in limbs, 5 patients had an association with Tessier number 11 cleft, 3 patients with number 9 cleft, and 1 with number 7 cleft. Related to cleft lip, 10 patients had bilateral cleft lip, and 8 patients had unilateral cleft lip. Three patients did not have any involvement of the upper lip. The alar base was deviated upward in 19 patients, 11 cases had severe anatomic alteration with the lateral border of the ala above the medial canthus, and 8 cases had a mild dislocation. Nine cases of lacrimal duct obstruction and 8 cases of lacrimal duct extrophy were identified. Twelve patients had a lower eyelid coloboma of varying grades, and there were 2 cases of microblepharia. Aiming the soft tissue reconstruction, eyelid, nose, and upper lip were evaluated regarding their position, absence of tissue, and position of medial canthus and ala. Twelve of our patients underwent correction in the same moment, their medial canthus rotated upward and the ala downward, using the contralateral side as the reference. The lip was treated using a Millard-like technique. Neo-conjunctivorhinostomy was performed in the same moment in 2 patients or later in 1 case. Four patients had plagiocephaly due to the cranial involvement, and they were submitted to cranioplasty. Three had neurosurgical approach and advancement of the frontal bandeau. One adult patient received an acrylic plate to reshape the frontal area. Conclusions: Tessier number 3 cleft is one of the most difficult and challenging malformations to correct for the reconstructive surgeon. Besides the difficulties of its treatment, patients with Tessier number 3 cleft may achieve good results when the team has good skills.

The challenge of multidrug resistance: The treatment of gram-negative rod infections

Infections caused by multidrug-resistant gram-negative bacteria are an increasing problem worldwide. Treatment of these microorganisms is a challenge because resistance limits dramatically therapeutic options. In this review, we discuss data of in vitro susceptibility and clinical studies of possible agents for the management of these infections. Currently, published data are limited, and there are no randomized clinical trials involving the treatment of infections caused by multidrug-resistant gram-negative rods. For imipenem-resistant Acinetobacter spp., most studied options are polymyxins and sulbactam. No newer antimicrobials active against Pseudomonas aeruginosa are available or under investigation. Tigecycline presents a broad spectrum of activity in vitro but has been studied mainly as treatment of community-acquired infections, as has ertapenem. They are potential options against extended-spectrum P-lactamase-producing Enterobacteriaceae, and tigecycline may be useful in treating Acinetobacter infections.

Eosinophils in bronchial mucosa of asthmatics after allergen challenge: effect of anti-IgE treatment

Anti-IgE, omalizumab, inhibits the allergen response in patients with asthma. This has not been directly related to changes in inflammatory conditions. We hypothesized that anti-IgE exerts its effects by reducing airway inflammation. To that end, the effect of anti-IgE on allergen-induced inflammation in bronchial biopsies in 25 patients with asthma was investigated in a randomized, double-blind, placebo-controlled study. Allergen challenge followed by a bronchoscopy at 24 h was performed at baseline and after 12 weeks of treatment with anti-IgE or placebo. Provocative concentration that causes a 20% fall in forced expiratory volume in 1 s (PC(20)) methacholine and induced sputum was performed at baseline, 8 and 12 weeks of treatment. Changes in the early and late responses to allergen, PC(20), inflammatory cells in biopsies and sputum were assessed. Both the early and late asthmatic responses were suppressed to 15.3% and 4.7% following anti-IgE treatment as compared with placebo (P < 0.002). This was paralleled by a decrease in eosinophil counts in sputum (4-0.5%) and postallergen biopsies (15-2 cells/0.1 mm(2)) (P < 0.03). Furthermore, biopsy IgE+ cells were significantly reduced between both the groups, whereas high-affinity IgE receptor and CD4+ cells were decreased within the anti-IgE group. There were no significant differences for PC(20) methacholine. The response to inhaled allergen in asthma is diminished by anti-IgE, which in bronchial mucosa is paralleled by a reduction in eosinophils and a decline in IgE-bearing cells postallergen without changing PC(20) methacholine. This suggests that the benefits of anti-IgE in asthma may be explained by a decrease in eosinophilic inflammation and IgE-bearing cells.

Characterization of leptospiral proteins that afford partial protection in hamsters against lethal challenge with Leptospira interrogans

Leptospirosis is a worldwide zoonosis caused by pathogenic Leptospira. The whole-genome sequence of Leptospira interrogans serovar Copenhageni together with bioinformatic tools allow us to search for novel antigen candidates suitable for improved vaccines against leptospirosis. This study focused on three genes encoding conserved hypothetical proteins predicted to be exported to the outer membrane. The genes were amplified by PCR from six predominant pathogenic serovars in Brazil. The genes were cloned and expressed in Escherichia coli strain BL21-SI using the expression vector pDEST17. The recombinant proteins tagged with N-terminal 6xHis were purified by metal-charged chromatography. The proteins were recognized by antibodies present in sera from hamsters that were experimentally infected. Immunization of hamsters followed by challenge with a lethal dose of a virulent strain of Leptospira showed that the recombinant protein rLIC12730 afforded statistically significant protection to animals (44 %), followed by rLIC10494 (40 %) and rLIC12922 (30 %). Immunization with these proteins produced an increase in antibody titres during subsequent boosters, suggesting the involvement of a T-helper 2 response. Although more studies are needed, these data suggest that rLIC12730 and rLIC10494 are promising candidates for a multivalent vaccine for the prevention of leptospirosis.