Perineural versus intravenous dexamethasone as adjuncts to local anaesthetic brachial plexus block for shoulder surgery.

This randomised, double-blind, placebo-controlled study compared the effect of perineural with intravenous dexamethasone, both administered concomitantly with interscalene brachial plexus block for shoulder surgery. Patients received 8 mg dexamethasone mixed with ropivacaine in the block injection (n = 42), 8 mg dexamethasone intravenously at the time of the block (n = 37), or intravenous saline (n = 41) at the time of the block. Perineural and intravenous dexamethasone resulted in prolonged mean (SD) duration of block to 16.9 (5.2) h and 18.2 (6.4) h, respectively, compared with 13.8 (3.8) h for saline (p = 0.001). Mean (SD) opioid consumption (morphine equivalents) during the first 24 h after postanaesthesia recovery arrival was 12.2 (9.3) mg in the perineural dexamethasone, 17.1 (15.9) mg in the intravenous dexamethasone and 24.1 (14.3) mg in the saline groups (p = 0.001). Dexamethasone via either route reduced anti-emetic use (p = 0.046). There was no effect on patient satisfaction. These results suggest that both perineural and intravenous dexamethasone are useful adjuncts to ropivacaine interscalene block, with the intravenous route preferred as this avoids the possibility of neural toxicity of dexamethasone.

[Extinction of large herbivore mammals: niche characteristics of musk ox Ovibos moschatus and reindeer Rangifer tarandus coexisting in isolation].

The extinction of large northern herbivores is a puzzle for many biologists. It is long debated whether climate change or human activity was the main factor of the extinction. The survival of the weak trophic competitors should reject the climatic hypothesis. Extant species of Pleistocene communities allow testing this explicitly. Up to date, reindeer and musk ox coexist in the Arctic territory. Their island populations provide a unique natural experiment to assess the role of competition. On Wrangel Island, their population sizes show the opposite trends and the same situation recurs on other Arctic islands--the reindeer population size decreases with the muskoxen population increasing. We have shown that the trends are defined by food-web structure. Niche overlap between species is found to .be considerable and cannot be facilitated by habitat partitioning. The number of plant species in the muskoxen diet was higher than in the reindeer. The exclusive part of the muskoxen diet was higher as well. Food webs in all of the habitat types showed the same relation. However, the changes in herbivores distribution during the Pleistocene demonstrate the opposite pattern. Therefore, the competitive advantage could not save the Palaearctic musk ox, and the extinction seems to be a result of selective overkill. Conclusively, the human activity may be considered as the main factor of the Late Pleistocene herbivore extinctions, and the musk ox reintroducing should be coupled with extensive conservational measures.

Testicular fluorine-18 fludeoxyglucose uptake on positron emission tomography CT in patients with lymphoma: clinical significance and management impact.

OBJECTIVE: This is the first case series examining the role of fluorine-18 fludeoxyglucose ((18)F-FDG) positron emission tomography-CT (PET-CT) in the diagnosis of lymphoma, and its impact on the clinical management of patients with secondary testicular involvement. This study explores the clinical significance of abnormal testicular uptake, maximum standardized uptake values and the diagnostic value of the CT component in PET-CT scans of these patients. METHODS: The case notes and PET scans of 12 patients with diagnosis of lymphoma that were reported to have abnormal (18)F-FDG uptake in the testes were examined. Case notes were reviewed for the underlying diagnosis, indication for the scan and its effect on the management decision. RESULTS: 12 patients demonstrated abnormal (18)F-FDG uptake on the PET-CT scans (mean age, 63 years; range, 37-82 years). Seven patients were diagnosed with testicular lymphoma. Six out of the seven (86%) patients received additional intrathecal chemotherapy in addition to their systemic chemotherapy, and one patient had testicular radiotherapy. CONCLUSION: This study establishes the importance of identifying and reporting abnormal (18)F-FDG uptake in the testes on PET-CT in patients with lymphoma. (18)F-FDG PET-CT is superior to conventional imaging in identifying testicular lymphoma and has significant management impact. It also emphasizes the importance of incorporating the testes as part of the scan coverage. ADVANCES IN KNOWLEDGE: The appearances of testicular lymphoma on (18)F-FDG PET-CT can be variable and abnormal testicular uptake warrants further investigations and confirmation. FDG PET-CT is an important tool and can be used in addition to conventional imaging in the identification of testicular lymphoma.

Health of adults living with a clinically significant haemoglobinopathy in New South Wales, Australia.

AIM: To comprehensively review the health needs of patients living with clinically significant haemoglobinopathies (thalassaemia and sickle-cell disease (SCD)) in New South Wales, Australia. METHODS: A survey-based health needs assessment was undertaken in outpatients cared for at five tertiary institutions in metropolitan and regional centres. Sixty-three of 121 adults (approximately 80-90% of adult patients with transfusion-requiring haemoglobinopathies in New South Wales) completed an in-house and commercial health-related quality assessment survey (SF-36v2). RESULTS: Subjects came from more than eight world regions, with those with SCD being more likely to be born outside of Australia than subjects with thalassaemia (P < 0.001, likelihood ratio 20.64) as well as more likely to have been refugees (26% vs 2%). The population contained socially disadvantaged subjects with 13 subjects (20.6%) having incomes below the Australian poverty line. Complications of thalassaemia were comparable to previous international reports although our subjects had a high rate of secondary amenorrhea (>12 months = 27%) and surgical splenectomy (55.6%). Use of hydroxyurea in SCD was less than expected with only 46.6% of subjects having prior use. Lack of universal access to magnetic resonance imaging-guided chelation (international best practice) was evident, although 65.5% had been able to access magnetic resonance imaging through clinical trial, or self-funding. CONCLUSIONS: Patients with SCD and thalassaemia experience considerable morbidity and mortality and require complex, multidisciplinary care. This study revealed both variance from international best practice and between specialist units. The results of this research may provide the impetus for the development of clinical and research networks to enable the uniform delivery of health services benchmarked against international standards.

[Peculiarities of a socio-hygienic picture of tuberculosis patients depending on the place of residence].

In the course of the study significant social factors and conditions characterizing patients with active tuberculosis were identified. Depending on the place of patient's residence the working out of a targeted complex of measures is required.

The immature reticulocyte fraction: a negative predictor of the harvesting of CD34 cells for autologous peripheral blood stem cell transplantation.

The optimal time for the harvesting of peripheral blood stem cells following chemotherapy and growth factors for autologous transplantation is based on the CD34 cell count. In this study, 51 patients having 59 stem cell mobilizations were assessed for the timing of the harvest by a CD34 cell count and an immature reticulocyte fraction (IRF). Results from 272 preharvest tests showed that when the CD34 cells were not harvestable, defined as a CD34 cell count of < 15 cells/microl, the IRF was always < or = 0.2. A low IRF resulted in a negative predictive value of 1 for the harvesting of stem cells. The IRF is therefore a valuable negative predictor of the timing of autologous stem cell harvesting.

Direct comparison of 18F-fluorodeoxyglucose coincidence gamma camera tomography with gallium scanning for the staging of lymphoma.

BACKGROUND: The present study compared the performance of 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) using a coincidence dual-head gamma camera (FDG Co-PET) with 67gallium scinti graphy (GS) in pretreatment staging of lymphoma. METHODS: A total of 46 patients underwent FDG Co-PET, computed tomography (CT) scanning and GS for pretreatment staging of lymphoma (40 newly diagnosed and recurrence) between November 1997 and December 1999. RESULTS: Histological subgroups comprised low grade (8 patients), intermediate grade (25) high-grade (3) non-Hodgkin's lymphoma and Hodgkin's disease (10). Based on clinical assessment, CT scan findings and biopsy, 100 nodal sites and 15 extra-nodal sites were deemed positive. FDG Co-PET was superior to GS in nodal site positivity rate (97%vs 79%, P < 0.0001). Compared with GS, FDG Co-PET detected 39 more abnormal sites in 22 patients (48%), of which 28 sites were validated by biopsy, CT and/or progress FDG Co-PET scanning. There was only one proven false negative FDG site in the spleen. CT + FDG Co-PET led to upstaging in 2 patients (4%), compared to CT + GS. CONCLUSION: FDG Co-PET shows potential for providing an accurate means for pretreatment staging of lymphoma and can detect extra sites of disease activity compared to GS.

Smoking rain clouds over the Amazon.

Heavy smoke from forest fires in the Amazon was observed to reduce cloud droplet size and so delay the onset of precipitation from 1.5 kilometers above cloud base in pristine clouds to more than 5 kilometers in polluted clouds and more than 7 kilometers in pyro-clouds. Suppression of low-level rainout and aerosol washout allows transport of water and smoke to upper levels, where the clouds appear "smoking" as they detrain much of the pollution. Elevating the onset of precipitation allows invigoration of the updrafts, causing intense thunderstorms, large hail, and greater likelihood for overshooting cloud tops into the stratosphere. There, detrained pollutants and water vapor would have profound radiative impacts on the climate system. The invigorated storms release the latent heat higher in the atmosphere. This should substantially affect the regional and global circulation systems. Together, these processes affect the water cycle, the pollution burden of the atmosphere, and the dynamics of atmospheric circulation.

Power of exclusion for parentage verification and probability of match for identity in American Kennel Club breeds using 17 canine microsatellite markers.

DNA analysis of microsatellite markers has become a common tool for verifying parentage in breed registries and identifying individual animals that are linked to a database or owner. Panels of markers have been developed in canines, but their utility across and within a wide range of breeds has not been reported. The American Kennel Club (AKC) authorized a study to determine the power to exclude non-parents and identify individuals using DNA genotypes of 17 microsatellite markers in two panels. Cheek swab samples were voluntarily collected at Parent Breed Club National Specialty dog shows and 9561 samples representing 108 breeds were collected, averaging 88.5 dogs per breed. The primary panel of 10 markers exceeded 99% power of exclusion for canine parentage verification of 61% of the breeds. In combination with the secondary panel of seven markers, 100% of the tested breeds exceeded 99% power of exclusion. The minimum probability match rate of the first panel was 3.6 x 10(-5) averaged across breeds, and with the addition of the second panel, the probability match rate was 3.2 x 10(-8); thus the probability of another random, unrelated dog with the same genotype is very low. The results of this analysis indicated that, on average, the primary panel meets the AKC's needs for routine parentage testing, but that a combination of 10-15 genetic markers from the two panels could yield a universal canine panel with enhanced processing efficiency, reliability and informativeness.

Investigation of eye splash and needlestick incidents from an HIV-positive donor on an intensive care unit using root cause analysis.

BACKGROUND: Two doctors working on a busy intensive care unit sustained injuries whilst removing a chest drain from an HIV-positive patient. One doctor had a needlestick injury into his finger whilst the other sustained an eyesplash when the chest drain was pulled out. METHODS: Following Department of Health format 'Doing less harm', a root cause and human factor analysis of the incident was carried out. The aim was to explore the underlying issues. RESULTS AND CONCLUSIONS: Training, cultural and organizational issues were exposed, and are now being addressed. This approach has led to a far more effective dialogue with the National Health Trust concerned than was previously experienced, and there is early evidence of progress on important aspects of health and safety management at organizational level. Lack of health and safety training of doctors at undergraduate and postgraduate level needs to be addressed.

Aerosols, climate, and the hydrological cycle.

Human activities are releasing tiny particles (aerosols) into the atmosphere. These human-made aerosols enhance scattering and absorption of solar radiation. They also produce brighter clouds that are less efficient at releasing precipitation. These in turn lead to large reductions in the amount of solar irradiance reaching Earth's surface, a corresponding increase in solar heating of the atmosphere, changes in the atmospheric temperature structure, suppression of rainfall, and less efficient removal of pollutants. These aerosol effects can lead to a weaker hydrological cycle, which connects directly to availability and quality of fresh water, a major environmental issue of the 21st century.

Topography of cerebral white-matter disease of prematurity studied prospectively in 1607 very-low-birthweight infants.

The objective of this study was to evaluate to what extent (1) the characteristics of localization, distribution, and size of echodense and echolucent abnormalities enable individuals to be designated as having either periventricular hemorrhagic infarction or periventricular leukomalacia and (2) the characteristics of periventricular hemorrhagic infarction and periventricular leukomalacia are independent occurrences. The population for this study consisted of 1607 infants with birthweights of 500 to 1500 g, born between January 1991 and December 1993, who had at least one cranial ultrasound scan read independently by at least two ultrasonographers. The ultrasound data collection form diagrammed six standard coronal views. The cerebrum was divided into 17 zones in each hemisphere. All abnormalities were described as being echodense or echolucent and were classified on the basis of their size, laterality, location, and evolution. Eight percent (134/1607) of infants had at least one white-matter abnormality. The prevalence of white-matter disease decreased with increasing gestational age. Most abnormalities were small or medium sized and unilateral; only large echodensities tended to be bilateral and asymmetric. Large abnormalities, whether echodense or echolucent, were more likely than smaller abnormalities to be widespread, and the extent of cerebral involvement was independent of whether abnormalities were unilateral or bilateral. Large abnormalities were relatively more likely than small abnormalities to involve anterior planes. Small abnormalities, whether echodense or echolucent, or whether unilateral or bilateral, preferentially occurred near the trigone. Using the characteristics of location, size, and laterality/symmetry, we were able to allocate only 53% of infants with white-matter abnormalities to periventricular hemorrhagic infarction or periventricular leukomalacia. Assuming that periventricular leukomalacia and periventricular hemorrhagic infarction are independent and do not share risk factors, and that each occurs in approximately 5% of infants, we would have expected 0.25%, or about 4 individuals, to have abnormalities with characteristics of both periventricular leukomalacia and periventricular hemorrhagic infarction, whereas we found 63 such infants. Most infants with white-matter disease could not be clearly designated as having periventricular hemorrhagic infarction or periventricular leukomalacia only. Periventricular hemorrhagic infarction contributes to the risk of periventricular leukomalacia occurrence, or the two sorts of abnormalities share common risk antecedent factors. The descriptive term echodense or echolucent and the generic term white-matter disease of prematurity should be used instead of periventricular leukomalacia or periventricular hemorrhagic infarction when referring to sonographically defined white-matter abnormalities.

Failed treatment of abdominal pregnancy with methotrexate. A case report.

BACKGROUND: Methotrexate is an effective, safe, low-cost alternative to surgery for treating tubal pregnancies. To our knowledge, there have only been two other reported attempts at treating abdominal pregnancy with methotrexate. CASE: Despite two courses of treatment with methotrexate, the pregnancy persisted, and laparoscopy permitted a tissue diagnosis of abdominal pregnancy. CONCLUSION: Although treatment with methotrexate was not successful in this case, its potential use in abdominal pregnancies merits further investigation.

Desert dust suppressing precipitation: a possible desertification feedback loop.

The effect of desert dust on cloud properties and precipitation has so far been studied solely by using theoretical models, which predict that rainfall would be enhanced. Here we present observations showing the contrary; the effect of dust on cloud properties is to inhibit precipitation. Using satellite and aircraft observations we show that clouds forming within desert dust contain small droplets and produce little precipitation by drop coalescence. Measurement of the size distribution and the chemical analysis of individual Saharan dust particles collected in such a dust storm suggest a possible mechanism for the diminished rainfall. The detrimental impact of dust on rainfall is smaller than that caused by smoke from biomass burning or anthropogenic air pollution, but the large abundance of desert dust in the atmosphere renders it important. The reduction of precipitation from clouds affected by desert dust can cause drier soil, which in turn raises more dust, thus providing a possible feedback loop to further decrease precipitation. Furthermore, anthropogenic changes of land use exposing the topsoil can initiate such a desertification feedback process.

Uterus didelphys with obstructed hemivagina and ipsilateral renal agenesis. A case report.

BACKGROUND: Uterus didelphys with obstructed hemivagina and ipsilateral renal agenesis usually presents after menarche with progressive abdominal pain during menses secondary to hematocolpos. We describe a case with the unique presentation of rectal pain and constipation. CASE: A 13-year-old girl presented to the emergency department complaining of lower abdominal and rectal pain and constipation of two weeks' duration. Pelvic ultrasound, physical examination and laparoscopic findings established a diagnosis of hematometracolpos secondary to uterus didelphys with unilateral imperforate hemivagina. An incision in the vaginal septum allowed drainage of the hematocolpos, providing relief of the patient's symptoms. CONCLUSION: Uterus didelphys with unilateral imperforate hemivagina and ipsilateral renal agenesis may present with apparent gastrointestinal symptoms. With increased awareness of this problem, timely diagnosis may be achieved.

Topographic mapping of brain potentials in the newborn infant: the establishment of normal values and utility in assessing infants with neurological injury.

AIM: To demonstrate that quantitative EEG (qEEG) can be used as a non-invasive measure of brain injury by establishing normative data in term infants and contrasting it with other modalities of brain imaging. DESIGN: qEEG during quiet sleep was performed on 13 healthy full-term infants comprising a normal group and on 10 infants with neurological abnormalities identified on brain imaging studies (abnormal group) at 36-47 wk postconceptional age. Quantitative analysis was performed and topographic maps were produced for each patient. The EEG data from the normal group, after spectral analysis, yielded power data in the delta, theta, alpha, and beta frequency bands and coherence information, which then formed the normative database. qEEG from the infants in the abnormal group was then compared to this normative data. RESULTS: The normal group's mean absolute power in the delta, theta, alpha, and beta bands for all EEG leads combined were 278.48+/-83.83, 31.71+/-10.12, 29.20+/-2.04, and 35.76+/-11.35 uv2, respectively. The median frequency was 1.49+/-0.07, 5.45+/-3.46, 9.74+/-5.11, and 18.01+/-3.38 Hz, respectively. The qEEG was abnormal in all 10 study infants, while abnormalities were noted in the clinical EEG in 4 of 10, in the neuroultrasound in 5 of 10, in the CT in one of 6, and in the MRI in 2 of 2 tested. CONCLUSIONS: qEEG appears to be a useful non-invasive method for measuring brain injury as it correlates well with other modalities of brain imaging and, if corroborated by further study, may, in fact, be more sensitive in determining abnormalities in brain function.

Deep convective clouds with sustained supercooled liquid water down to -37.5 degrees C

In cirrus and orographic wave clouds, highly supercooled water has been observed in small quantities (less than 0.15 g m(-3)). This high degree of supercooling was attributed to the small droplet size and the lack of ice nuclei at the heights of these clouds. For deep convective clouds, which have much larger droplets near their tops and which take in aerosols from near the ground, no such measurements have hitherto been reported. However, satellite data suggest that highly supercooled water (down to -38 degrees C) frequently occurs in vigorous continental convective storms. Here we report in situ measurements in deep convective clouds from an aircraft, showing that most of the condensed water remains liquid down to -37.5 degrees C. The droplets reach a median volume diameter of 17 microm and amount to 1.8 gm(-3), one order of magnitude more than previously reported. At slightly colder temperatures only ice was found, suggesting homogeneous freezing. Because of the poor knowledge of mixed-phase cloud processes, the simulation of clouds using numerical models is difficult at present. Our observations will help to understand these cloud processes, such as rainfall, hail, and cloud electrification, together with their implications for the climate system.

Suppression of rain and snow by urban and industrial air pollution

Direct evidence demonstrates that urban and industrial air pollution can completely shut off precipitation from clouds that have temperatures at their tops of about -10 degrees C over large areas. Satellite data reveal plumes of reduced cloud particle size and suppressed precipitation originating from major urban areas and from industrial facilities such as power plants. Measurements obtained by the Tropical Rainfall Measuring Mission satellite reveal that both cloud droplet coalescence and ice precipitation formation are inhibited in polluted clouds.