Spontaneous arteriovenous malformation of the external auditory meatus

Arteriovenous malformations (AVM) of the head and neck are rare. They usually occur intracranially and derive their vascular supply from the intracranial vessels. In the English literature there has not been any documented case of AVMs in and around the external auditory meatus (EAM). The authors present the first case, a spontaneous AVM deriving its vascular supply from the posterior auricular artery. The diagnostic difficulties and management strategies of spontaneous AVMs are discussed.     

Osseointegrated implants in the management of childhood ear abnormalities: with particular emphasis on complications

Little has been published about the difficulties encountered during the insertion of osseointegrated implants for the attachment of bone anchored hearing aids (BAHA) and auricular prostheses in children. This study examines this issue in the first 51 children implanted at our centre. During surgery, the most common problem encountered was the presence of thin bone resulting in incomplete insertion of fixtures. Five fixtures had failed to integrate and six fixtures were lost in the long-term, however, only five children required revision surgery. The reason why few patients require revision was due to the judicious insertion of 'sleeper' fixtures. At follow-up, seven children required counselling for psychological problems. It is apparent from this study that osseointegrated implants in children are associated with difficulties, re-emphasizing that a paediatric osseointegration programme requires significant investment, and should only be undertaken by institutions that are committed to its success.     

Twelve tips for incorporating the study of human rights into medical education

Abstract

In order for patients to be adequately cared for by clinicians, an awareness and acknowledgement of the factors that affect their well-being, including adherence to internationally recognized human rights, should be part of the professional education of all health care professionals. Worldwide conflicts, which have led to record forced global displacement, and ongoing international human rights violations have had profound effects on the health and well-being of millions of patients. Trainees early in their careers should be educated about these and related population-level issues that affect the health of their patients, so they can better care and advocate for their patients and communities throughout their careers.     

Central serous retinopathy (choroidopathy) in pilots

The clinical charts of pilots in the Israeli Airforce were reviewed retrospectively for evidence of central serous retinopathy (CSR). There were 14 pilots with documented CSR identified, with an incidence of 1.3 per 1000 per year. Of 6 pilots who had recurrent attacks, 5 had a decrease of visual acuity during the initial attack to at least 20/30 in the affected eye. On the other hand, in those with visual acuity no worse than 20/25, only 1 of 7 had recurrent attacks (p less than 0.05). We conclude that CSR is a common condition in pilots, and that visual acuity during the initial attack can predict those who will have recurrent disease.     

Bilateral submandibular duct relocation for drooling: an evaluation of results for the Birmingham Children's Hospital

Drooling is a problem of the neurologically impaired that often leads to stigmatisation and social isolation. Bilateral submandibular duct relocation (BSMDR) is a surgical procedure that may be used to control troublesome drooling. The aim of this study was to assess the results following surgery and attempt to identify those factors that would mitigate against a successful outcome. A retrospective case note review was performed, and data were collected on 23 neurologically impaired patients who underwent the procedure between 1993 and 2000 at the Birmingham Children's Hospital, UK. An overall improvement in drooling was demonstrated in 20 (87%) cases, with complete cessation of drooling in 13 (57%) cases. The complications included one ranula, three transient submandibular gland swellings and two persistent swellings requiring gland excision. It is difficult to predict which patients will have an unsuccessful outcome following surgery. In our series, three (13%) patients had poor results. We could not determine any special features that could account for this, except that these patients in particular demonstrated the greatest degree of oral-motor dysfunction. BSMDR is a technically straightforward procedure associated with minimal morbidity and a high success rate. It is the procedure of choice at our institution.     

Updating concepts of first branchial cleft defects: a literature review.

OBJECTIVE: The Sinuses and fistulae of first branchial cleft origin have been widely reported in the literature and their variable relationship to the facial nerve has been described. Most published series however are too small to allow a detailed analysis of the relative frequency of various relationships of these lesions to the facial nerve and therefore enabling the determination of risks to the nerve at surgery. The aim of this study was to perform a comprehensive review of literature in an attempt to identify those patients with a deep tract (lying deep to the main trunk of the facial nerve and/or its branches, and/or between the branches) and to recognize the incidence of the complications of surgical management. METHODS: Available English, French and German literature between 1923 and 2000 was reviewed and variables including patient's age, sex, side and type of anomaly, opening of the lesion and the relationship of the tract are analyzed in relation to the position of the facial nerve. The complications due to their surgical excision are also reported. RESULTS: Of the total number of cases with fistulae and sinuses identified (n=158) fistulous tracts were more likely to lie deep to the facial nerve compared with sinus tracts (P=0.01). Lesions with openings in the external auditory meatus are associated with a tract superficial to the facial nerve (P=0.05). Patients presenting at a younger age were more likely to have a deep tract with consequent increased risk of facial nerve damage. CONCLUSION: Identification of the facial nerve trunk at an early stage of dissection is critical. Extra care and caution should be exercised in younger patients (<6 months), those with fistulous tracts and in patients with a tract opening elsewhere other than the external auditory canal.     

Synergistic dispersal of plant pathogen spores by jumping-droplet condensation and wind

Plant pathogens are responsible for the annual yield loss of crops worldwide and pose a significant threat to global food security. A necessary prelude to many plant disease epidemics is the short-range dispersal of spores, which may generate several disease foci within a field. New information is needed on the mechanisms of plant pathogen spread within and among susceptible plants. Here, we show that self-propelled jumping dew droplets, working synergistically with low wind flow, can propel spores of a fungal plant pathogen (wheat leaf rust) beyond the quiescent boundary layer and disperse them onto neighboring leaves downwind. An array of horizontal water-sensitive papers was used to mimic healthy wheat leaves and showed that up to 25 spores/h may be deposited on a single leaf downwind of the infected leaf during a single dew cycle. These findings reveal that a single dew cycle can disperse copious numbers of fungal spores to other wheat plants, even in the absence of rain splash or strong gusts of wind.

Spores of plant pathogenic fungi are spread through the atmosphere in three stages: liberation from the host by some active or passive method(s), drift by biotic or abiotic factors, and deposition onto a new host (1). Examples of active liberation mechanisms include osmotic pressure–driven ejection of ascospores of Fusarium graminearum (the causal agent of Fusarium head blight of wheat) and ballistospore ejection from the tip of a sterigma due to the chemical secretion of a Buller’s drop (2, 3). In the absence of wind, the resulting dispersal distance is a function of both the weight of the spore(s) and the initial discharge velocity, with the range of discharge varying from 40 μm for basidiospores (4) to 6 m for the artillery fungus (5). Passive liberation and dispersal mechanisms, such as wind and rain splash, can spread fungal diseases in plants (6). For wind to successfully liberate dry spores, an unusually strong and/or sudden gust of wind is often required (1, 6–9). In contrast, rain splash can liberate spores from a plant either through transferring momentum to the leaf to launch spores off (10, 11) or by adhering spores to splashed satellite droplets (12, 13). Spores ejected by active methods or rain splash can only disperse over a very short distance in the absence of wind (14) but when carried in moderate winds, can travel for many kilometers (15, 16).One recent study reported an entirely new mode of pathogen liberation, where coalescing dew droplets on superhydrophobic wheat leaves jump with considerable velocity (0.1 to 1.0 m/s) and carry adhered spores of a fungal plant pathogen (17). Mechanistically, the out-of-plane motion is a result of symmetry breaking as the expanding liquid bridge during coalescence impinges upon the bottom substrate (18–20) (Fig. 1A). While this initial report characterized the jumping-droplet liberation of spores in the absence of wind (17), it did not consider the subsequent dispersal or deposition, which ultimately governs the rate of disease spread. Here, we characterize the dispersal of spores of leaf rust (Puccinia triticina) after they are liberated from a diseased wheat leaf via jumping-droplet condensation. Two different scenarios are explored: short-range and long-range drift and deposition in the absence and presence of wind flow, respectively (Fig. 1 B and C). We found that even a low wind speed (0.5 m/s) is capable of dispersing as many as 100 jumping droplets and 25 spores to a single leaf downwind of a diseased leaf saturated in dew. Our ability to quantify both the liberation and dispersal of fungal spores from a diseased leaf during a dew cycle improves our understanding of disease spread within and among plants (1, 21–23).Open in a separate windowFig. 1.Spore dispersal via jumping-droplet condensation. (A) Jumping-droplet condensation on a healthy wheat leaf. Two condensed droplets coalesce (second frame) and jump off from the superhydrophobic wheat leaf (third frame). (B) Without any wind, the jumped droplets with spores can land on an adjacent healthy leaf, spreading the disease within the plant. (C) In low (0.5 m/s) to moderate (1.5 m/s) wind speed, the spore-laden jumped droplets can travel long-range to land on different healthy plants within the field.