Paediatric otogenic cerebral venous sinus thrombosis: a multidisciplinary approach.

BACKGROUND: Paediatric otogenic cerebral venous sinus thrombosis is a rare, heterogeneous and life-threatening condition, with possible otological, neurological and ophthalmological sequelae. Its course and outcomes can be widely variable. The publications available often consider individual aspects of paediatric otogenic cerebral venous sinus thrombosis management. The condition itself and the nature of the currently available guidance can lead to uncertainties when holistically managing patients with paediatric otogenic cerebral venous sinus thrombosis. OBJECTIVES: Clear recommendations for the comprehensive assessment and management of paediatric otogenic cerebral venous sinus thrombosis are presented, along with the literature review upon which they are based. Its clinical and radiological assessment are discussed. CONCLUSION: A multidisciplinary approach to assessment and management is recommended, inclusive of infectious diseases, ENT surgery, neurology, ophthalmology and haematology. On balance, anticoagulation is recommended for three months. Follow-up imaging is not recommended in the absence of clinical concern. Follow up by ENT surgery, neurology and ophthalmology departments is recommended.

Initial assessment in the management of adult epistaxis: systematic review.

BACKGROUND: The initial assessment of epistaxis patients commonly includes: first aid measures, observations, focused history taking, and clinical examinations and investigations. This systematic review aimed to identify evidence that informs how the initial assessment of these patients should be conducted. METHOD: A systematic review of the literature was performed using a standardised methodology and search strategy. RESULTS: Seventeen articles were included. Factors identified were: co-morbidity, intrinsic patient factors, coagulation screening and ice pack use. Hypertension and anticoagulant use were demonstrated to adversely affect outcomes. Coagulation screening is useful in patients on anticoagulant medication. Four studies could not be accessed. Retrospective methodology and insufficient statistical analysis limit several studies. CONCLUSION: Sustained ambulatory hypertension, anticoagulant therapy and posterior bleeding may be associated with recurrent epistaxis, and should be recorded. Oral ice pack use may decrease severity and can be considered as first aid. Coagulation studies are appropriate for patients with a history of anticoagulant use or bleeding diatheses.

Prioritising topics for the undergraduate ENT curriculum.

OBJECTIVE: Knowledge of ENT is important for many doctors, but undergraduate time is limited. This study aimed to identify what is thought about ENT knowledge amongst non-ENT doctors, and the key topics that the curriculum should focus on. METHODS: Doctors were interviewed about their views of ENT knowledge amongst non-ENT doctors, and asked to identify key topics. These topics were then used to devise a questionnaire, which was distributed to multiple stakeholders in order to identify the key topics. RESULTS: ENT knowledge was generally thought to be poor amongst doctors, and it was recommended that undergraduate ENT topics be kept simple. The highest rated topics were: clinical examination; when to refer; acute otitis media; common emergencies; tonsillitis and quinsy; management of ENT problems by non-ENT doctors; stridor and stertor; otitis externa; and otitis media with effusion. CONCLUSION: This study identified a number of key ENT topics, and will help to inform future development of ENT curricula.

Frontal sinus mucocoeles: new algorithm for surgical management.

BACKGROUND: Frontal sinus mucocoeles require a structured approach to their surgical management. We share our experience of a novel method of positional classification for frontal mucocoele and corresponding surgical algorithm. METHODS: A retrospective case-note review examined all frontal sinus surgery for mucocoele, spanning three years (2008-2010). Patients had pre-operative nasendoscopy, multi-planar CT and MRI when indicated. Several important variables (position, drainage dimensions, fronto-ethmoidal cells and degree of neo-osteogenesis) were noted. A systematic algorithm was used for surgical drainage based on these characteristics. The three year outcomes using this approach are presented. RESULTS: Thirty-six patients were identified with a total of 43 frontal mucocoeles. Using our classification, 30 mucocoeles were medial; seven were intermediate; six were lateral. Thirty-four patients underwent a primary endoscopic procedure; six required a combined primary osteoplastic-flap (OPF) and endoscopic approach. Six patients required revision surgery for polypoidal change or neo-ostium stenosis. All patients were eventually rendered asymptomatic. CONCLUSION: Implementation of our positional classification and surgical algorithm was successful with a revision rate of 19%. Presence of frontal sinus wall dehiscence and extra-sinus mucocoele extension are invalid indicators for external approach. We feel our classification and treatment algorithm, with its associated indicators for surgical escalation (i.e. limited dimensions of frontal ostium, presence of Type III / IV front-ethmoidal cells etc), are applicable for future management of frontal mucocoeles.

Metastatic malignant melanoma arising in a mature ovarian cystic teratoma: a case report and literature review.

Primary malignant melanoma arising inform the ovary is rare, with only 30 cases described in the literature to date. The case reported here occurred in a 19-year-old woman and was rapidly progressive, resulting in death only 37 days following initial presentation. Management of this case is discussed in the context of the other reported cases. Surgery, ranging from an ovarian cystectomy to a radical debulking procedure, has been the main treatment with adjuvant chemotherapy utilized in only 4 of the previous cases. Key problems in management relate to the ability to make the diagnosis at the time of surgery and the overall poor response rates of melanoma to adjuvant chemotherapy.

Noninvasive paternity assignment in Gombe chimpanzees.

The relative success of chimpanzee male mating strategies, the role of male dominance rank and the success of inbreeding avoidance behaviour can only be assessed when paternities are known. We report the probable paternities of 14 chimpanzees included in a long-term behavioural study of chimpanzees (Pan troglodytes schweinfurthii) at Gombe National Park, Tanzania. DNA samples were collected noninvasively from shed hair and faeces and genotyped using 13-16 microsatellite loci characterized in humans. All 14 offspring could be assigned to fathers within the community. While there is a positive relationship between male rank and reproductive success, we demonstrate that a range of male mating strategies (possessiveness, opportunistic mating and consortships) can lead to paternity across all male ranks. Several adult females were at risk of breeding with close male relatives. Most successfully avoided close inbreeding but in one case a high-ranking male in the community mated with his mother and produced an offspring. In contrast to recent data on chimpanzees (P. t. verus) from the Taï forest, Côte d'Ivoire, no evidence of extra-group paternity was observed in our study. Reanalysis of Taï data using a likelihood approach casts doubt on the occurrence of extra-group paternity in that community as well.

Recent dioxin contamination from Agent Orange in residents of a southern Vietnam city.

Marked elevation of dioxin associated with the herbicide Agent Orange was recently found in 19 of 20 blood samples from persons living in Bien Hoa, a large city in southern Vietnam. This city is located near an air base that was used for Agent Orange spray missions between 1962 and 1970. A spill of Agent Orange occurred at this air base more than 30 years before blood samples were collected in 1999. Samples were collected, frozen, and sent to a World Health Organization--certified dioxin laboratory for congener-specific analysis as part of a Vietnam Red Cross project. Previous analyses of more than 2200 pooled blood samples collected in the 1990s identified Bien Hoa as one of several southern Vietnam areas with persons having elevated blood dioxin levels from exposure to Agent Orange. In sharp contrast to this study, our previous research showed decreasing tissue dioxin levels over time since 1970. Only the dioxin that contaminated Agent Orange, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), was elevated in the blood of 19 of 20 persons sampled from Bien Hoa. A comparison, pooled sample from 100 residents of Hanoi, where Agent Orange was not used, measured blood TCDD levels of 2 parts per trillion (ppt). TCDD levels of up to 271 ppt, a 135-fold increase, were found in Bien Hoa residents. TCDD contamination was also found in some nearby soil and sediment samples. Persons new to this region and children born after Agent Orange spraying ended also had elevated TCDD levels. This TCDD uptake was recent and occurred decades after spraying ended. We hypothesize that a major route of current and past exposures is from the movement of dioxin from soil into river sediment, then into fish, and from fish consumption into people.

Influence of elevated CO2 and mycorrhizae on nitrogen acquisition: contrasting responses in Pinus taeda and Liquidambar styraciflua.

An understanding of root system capacity to acquire nitrogen (N) is critical in assessing the long-term growth impact of rising atmospheric CO2 concentration ([CO2]) on trees and forest ecosystems. We examined the effects of mycorrhizal inoculation and elevated [CO2] on root ammonium (NH4+) and nitrate (NO3-) uptake capacity in sweetgum (Liquidambar styraciflua L.) and loblolly pine (Pinus taeda L.). Mycorrhizal treatments included inoculation of seedlings with the arbuscular mycorrhizal (AM) fungus Glomus intraradices Schenck & Smith in sweetgum and the ectomycorrhizal (EM) fungus Laccaria bicolor (Maire) Orton in loblolly pine. These plants were then equally divided between ambient and elevated [CO2] treatments. After 6 months of treatment, root systems of both species exhibited a greater uptake capacity for NH4+ than for NO3-. In both species, mycorrhizal inoculation significantly increased uptake capacity for NO3-, but not for NH4+. In sweetgum, the mycorrhizal effect on NO3- and NH4+ uptake capacity depended on growth [C02]. Similarly, in loblolly pine, the mycorrhizal effect on NO3- uptake capacity depended on growth [CO2], but the effect on NH4+ uptake capacity did not. Mycorrhizal inoculation significantly enhanced root nitrate reductase activity (NRA) in both species, but elevated [CO2] increased root NRA only in sweetgum. Leaf NRA in sweetgum did not change significantly with mycorrhizal inoculation, but increased in response to [CO2]. Leaf NRA in loblolly pine was unaffected by either treatment. The results indicate that the mycorrhizal effect on specific root N uptake in these species depends on both the form of inorganic N and the mycorrhizal type. However, our data show that in addressing N status of plants under high [CO2], reliable prediction is possible only when information about other root system adjustments (e.g., biomass allocation to fine roots) is simultaneously considered.

Suitability of process-based tree growth models for addressing tree response to climate change.

Empirical models of tree growth have been used for many years to predict timber yields and other properties of trees. However, such models rely on measured relationships between tree growth and historic environmental conditions. As anthropogenic actions alter the environment, especially atmospheric composition, empirical models become less reliable and process-based models become more useful. Process-based models are challenged to simulate growth of structurally and physiologically complex organisms using explicit mathematical expressions to capture growth response to environmental conditions. In this review we summarize the physiological requirements of process-based models and examine the capabilities of six published models (CARBON, ECOPHYS, PGSM, TREE-BGC, TREGRO, W91) for simulating tree response to changes in environmental conditions (elevated temperature, increased CO(2) concentration, and enhanced concentrations of tropospheric ozone). These analyses indicate that current models are reliable integrators of environmental effects on individual processes (e.g. photosynthesis), but may be less reliable where physiological acclimation occurs or when extrapolated to growth of specific tree compartments.

Energetics of lengthening in mouse and toad skeletal muscles.

1. The energetics of lengthening were studied in amphibian and mammalian skeletal muscle. The aims were to determine whether energy absorption during stretch is a general property of skeletal muscle and to investigate the influence of lengthening velocity on energy absorption. 2. Experiments were performed in vitro (21 degrees C) using bundles of muscle fibres from fast-twitch extensor digitorum longus and slow-twitch soleus muscles of the mouse and tibialis anterior muscles of a toad, Bufo marinus. Initial heat production and mechanical work done on muscles were measured during isovelocity lengthening. Enthalpy output during lengthening was calculated as the difference between the amount of heat produced and the work done. 3. For all three muscle types, more energy was put into muscles as work than was produced as heat. Thus, part of the energy put into muscles to stretch them must have been absorbed. 4. For all three muscle types, the amount of energy absorbed was constant at velocities exceeding approximately 0.5 Vmax (Vmax is the maximum shortening velocity), but was significantly lower at slow velocities of lengthening. The same amount of energy was absorbed by all three muscles when lengthened at > or = 0.5 Vmax. 5. It was concluded that absorption of energy during lengthening occurs in mammalian as well as amphibian muscle and that lengthening velocity has only a small effect on the amount of energy absorbed.

Verse form : A pilot study in the epidemiology of representations.

This paper presents a pilot study in the "epidemiological" program for cultural research put forward by Dan Sperber. Theory is offered to argue that verse form is so disabling that its worldwide distribution must be explained by functions other than the broad communicative, or ideological, power traditionally attributed to it. The theoretical case is confirmed by numerical data showing that in matched texts of English prose and verse the latter contain words of a lower mean length (measured in syllables). Candidate hypotheses for the epidemiology of verse are offered, including design for mnemonic properties, the registration of differences in verbal intelligence, the presentation of gestures of commitment, and the introduction of levels of quasi-randomness that lead to an impression of semantic richness and the illusion of profound and powerful communication.

Simulating the response of mature yellow poplar and loblolly pine trees to shifts in peak ozone periods during the growing season using the TREGRO model.

Multiple TREGRO simulations were conducted with meteorological data files containing different growing season peak ozone (O(3)) episodes at O(3) exposures of 1.0 and 2.0 x ambient O(3) to assess the relationship between O(3) response and the phenology of mature yellow poplar (Liriodendron tulipifera L.) and loblolly pine (Pinus taeda L.) trees. Regardless of O(3) exposure and peak O(3) episode occurrence, a peak O(3) episode in August caused the greatest reduction in carbon (C) gain in yellow poplar, whereas a peak O(3) episode in July caused the greatest reduction in C gain of loblolly pine. In both species, timing of the greatest simulated O(3) effect corresponded with the completion of the annual foliage production phenophase. Simulated C gain of yellow poplar (total tree, coarse root, and total nonstructural carbohydrate) was reduced by O(3) to a greater extent than the corresponding compartments in loblolly pine, but the opposite was true for fine roots. This differential sensitivity to O(3) reflects the fact that both C assimilation and the O(3) response of the species were parameterized according to observed field measurements of each species. The differential sensitivity to O(3) of these species may have long-term implications for species composition in southeastern USA forests.

Agent Orange and the Vietnamese: the persistence of elevated dioxin levels in human tissues.

OBJECTIVES: The largest known dioxin contamination occurred between 1962 and 1970, when 12 million gallons of Agent Orange, a defoliant mixture contaminated with a form of the most toxic dioxin, were sprayed over southern and central Vietnam. Studies were performed to determine if elevated dioxin levels persist in Vietnamese living in the south of Vietnam. METHODS: With gas chromatography and mass spectroscopy, human milk, adipose tissue, and blood from Vietnamese living in sprayed and unsprayed areas were analyzed, some individually and some pooled, for dioxins and the closely related dibenzofurans. RESULTS: One hundred sixty dioxin analyses of tissue from 3243 persons were performed. Elevated 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) levels as high as 1832 ppt were found in milk lipid collected from southern Vietnam in 1970, and levels up to 103 ppt were found in adipose tissue in the 1980s. Pooled blood collected from southern Vietnam in 1991/92 also showed elevated TCDD up to 33 ppt, whereas tissue from northern Vietnam (where Agent Orange was not used) revealed TCDD levels at or below 2.9 ppt. CONCLUSIONS: Although most Agent Orange studies have focused on American veterans, many Vietnamese had greater exposure. Because health consequences of dioxin contamination are more likely to be found in Vietnamese living in Vietnam than in any other populations, Vietnam provides a unique setting for dioxin studies.

Chlorinated and brominated dioxins and dibenzofurans in human tissue following exposure.

With substantial improvements in analytic techniques over the past decade, it has become possible to measure polychlorinated dioxins (PCDDs) and dibenzofurans (PCDFs) in human tissue in a congener-specific fashion down to the low parts per trillion level. This paper reviews findings using these new techniques from a number of recent medical and environmental case studies. These studies include those of workers exposed to a polychlorinated biphenyl (PCB) transformer fire in the United States, German chemical workers exposed to 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD) while cleaning up after an explosion, workers at a municipal incinerator in New York City, a chemist exposed to brominated and chlorinated dioxins, U.S. veterans and also Vietnamese civilians exposed to Agent Orange contaminated with TCDD in Vietnam, and victims of the polychlorinated dibenzofuran and PCB contaminated rice oil (Yusho) incident in Japan.

Energetics of fast- and slow-twitch muscles of the mouse.

1. The energetic cost of work performance by mouse fast- and slow-twitch muscle was assessed by measuring the rates of thermal and mechanical energy liberation of the muscles at 21 degrees C. Thermal energy (heat) liberation was measured using a fast-responding thermopile. 2. Bundles of muscles fibres from the slow-twitch soleus and fast-twitch extensor digitorum longus (EDL) muscles were used. Work output was controlled by performing isovelocity shortenings during the plateau of an isometric tetanus. A range of shortening velocities, spanning the possible range, was used for each muscle. 3. During tetanic contractions, the rate of heat production from EDL muscle was 134.2 +/- 11.4 mW/g. The rate of heat production by soleus muscle was only one-fifth as great (26.8 +/- 2.7 mW/g). 4. The maximum shortening velocity (Vmax) of EDL muscles was 2.5-fold greater than that for soleus muscles and it's force-velocity relationship was less curved. Peak power output from EDL muscles was 3-fold greater than that from soleus muscle. 5. During shortening, the rate of heat output from soleus muscles increased considerably above the isometric heat rate. In contrast to soleus muscle, the rate of heat production by EDL muscle increased by only a small fraction of the isometric heat rate. The magnitude of the increases in rate was proportional to shortening velocity. 6. The total rate of energy liberation (heat rate + power) by EDL muscle, shortening at 0.95 Vmax was 1.62 +/- 0.37 times greater than the isometric heat rate. In contrast, the rate of energy liberation from soleus muscle shortening at 0.95 Vmax was 5.21 +/- 0.58 times greater than its isometric heat rate. The peak mechanical efficiency (power/total energy rate) of the both muscles was approximately 30%.

Influence of dietary protein on glomerular filtration and urinary albumin excretion in insulin-dependent diabetes.

We investigated the effects of dietary constituents on glomerular filtration (GFR) and albumin excretion rates (AERs) in a cross-sectional study in 39 young subjects with insulin-dependent diabetes. Dietary protein intake correlated significantly in patients with GFRs less than 150 mL/min per 1.73 m2 (r = 0.53, n = 23, P = 0.009), but not with AER. GFR also correlated with mean blood glucose at a concentration less than 12.0 mmol/L (r = 0.61, P = 0.0035). Protein and fat intakes were similar in patients with and without microalbuminuria (AER greater than 20 mg/L) but long-term glycemic control was worse in the former [HbA1 12.4 +/- 2.9% (mean +/- SD) and 10.6 +/- 2.1%, respectively, P = 0.043]. In seven patients, short-term reduction of dietary protein from 2.0 to 1.0 to 0.5 g.kg-1.d-1 produced a progressive fall in GFR by 11.6 +/- 6.0 and 9.6 +/- 5.9 mL/min, respectively (P less than 0.05), but did not consistently affect AER. We conclude that both dietary protein and glycemic control influence GFR but neither alone appears to explain glomerular hyperfiltration. Microalbuminuria was associated with poor glycemic control but not with dietary fat or protein consumption.