Variation in stem mortality rates determines patterns of above-ground biomass in Amazonian forests: implications for dynamic global vegetation models

Understanding the processes that determine above-ground biomass (AGB) in Amazonian forests is important for predicting the sensitivity of these ecosystems to environmental change and for designing and evaluating dynamic global vegetation models (DGVMs). AGB is determined by inputs from woody productivity [woody net primary productivity (NPP)] and the rate at which carbon is lost through tree mortality. Here, we test whether two direct metrics of tree mortality (the absolute rate of woody biomass loss and the rate of stem mortality) and/or woody NPP, control variation in AGB among 167 plots in intact forest across Amazonia. We then compare these relationships and the observed variation in AGB and woody NPP with the predictions of four DGVMs. The observations show that stem mortality rates, rather than absolute rates of woody biomass loss, are the most important predictor of AGB, which is consistent with the importance of stand size structure for determining spatial variation in AGB. The relationship between stem mortality rates and AGB varies among different regions of Amazonia, indicating that variation in wood density and height/diameter relationships also influences AGB. In contrast to previous findings, we find that woody NPP is not correlated with stem mortality rates and is weakly positively correlated with AGB. Across the four models, basin-wide average AGB is similar to the mean of the observations. However, the models consistently overestimate woody NPP and poorly represent the spatial patterns of both AGB and woody NPP estimated using plot data. In marked contrast to the observations, DGVMs typically show strong positive relationships between woody NPP and AGB. Resolving these differences will require incorporating forest size structure, mechanistic models of stem mortality and variation in functional composition in DGVMs.

[Atypical ganglioglioma with BRAF V600E mutation: a case report and review of the literature]

INTRODUCTION

Gangliogliomas are rare tumours that affect young patients, appear predominantly in the temporal lobe and usually begin with epileptic seizures. Histologically they have a grade I of malignancy, with an anaplastic form that is catalogued as grade III in the 2007 WHO classification. Yet, there are tumours that do not meet the criteria of either grade and which offer clear prognostic differences with respect to those of grade I. These tumours would be atypical gangliogliomas (grade II), which are not considered in this classification. From the molecular point of view, the best known alteration in gangliogliomas is the BRAF V600E mutation, which worsens the prognosis of the lesion. The possible use of treatments targeted towards this mutated protein is especially relevant in this disorder.

CASE REPORT

A 21-year-old male, who had undergone surgery due to a ganglioglioma on two occasions. The neuro-pathological examination revealed histological features consistent with an intermediate grade of malignancy (grade II), with positive BRAF mutation.

CONCLUSIONS

The case presented here, together with those previously reported in the literature, reopens the debate on the definition of gangliogliomas in the 2007 WHO classification, and lends support to the fact that the next classification should again include atypical gangliogliomas (grade II), together with possible genetic mutations and molecular disorders.

GA, Comiskey JA, Damasco G, Dávila N, García-Villacorta R, Diaz PRS, Vincentini A, Emilio T, Levis C, Schietti J, Souza P, Alonso A, Dallmeier F, Ferreira LV, Neill D, Araujo-Murakami A, Arroyo L, Carvalho FA, Souza FC, do Amaral DD, Gribel R, Luize BG, Pansonato MP, Venticinque E, Fine P, Toledo M, Baraloto C, Cerón C, Engel J, Henkel TW, Jimenez EM, Maas P, Mora MCP, Petronelli P, Revilla JDC, Silveira M, Stropp J, Thomas-Caesar R, Baker TR, Daly D, Paredes MR, da Silva NF, Fuentes A, Jørgensen PM, Schöngart J, Silman MR, Arboleda NC, Cintra BBL, Valverde FC, Di Fiore A, Phillips JF, van Andel TR, von Hildebrand P, Barbosa EM, de Matos Bonates LC, de Castro D, de Sousa Farias E, Gonzales T, Guillaumet JL, Hoffman B, Malhi Y, de Andrade Miranda IP, Prieto A, Rudas A, Ruschell AR, Silva N, Vela CIA, Vos VA, Zent EL, Zent S, Cano A, Nascimento MT, Oliveira AA, Ramirez-Angulo H, Ramos JF, Sierra R, Tirado M, Medina MNU, van der Heijden G, Torre EV, Vriesendorp C, Wang O, Young KR, Baider C, Balslev H, de Castro N, Farfan-Rios W, Ferreira C, Mendoza C, Mesones I, Torres-Lezama A, Giraldo LEU, Villarroel D, Zagt R, Alexiades MN, Garcia-Cabrera K, Hernandez L, Huamantupa-Chuquimaco I, Milliken W, Cuenca WP, Pansini S, Pauletto D, Arevalo FR, Sampaio AF, Valderrama Sandoval EH, Gamarra LV. Estimating the global conservation status of more than 15,000 Amazonian tree species

Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict that most of the world's >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century.

FYDATA STUDY: PERAMPANEL STUDY IN A REAL-LIFE SETTING

FYDATA is a multi-centre, retrospective, 1-year, observational study (inclusion criteria: written informed consent to review clinical charts; patients ≥12 years old; partial-onset seizure [POS] diagnosis; perampanel treatment according to clinical practice as add-on therapy; patients with ≥1 POS in year prior to starting perampanel). The source of data was patient clinical records collected by physicians. An interim analysis was performed at 3 months in 111 patients (mean age: 37.8 years; mean epilepsy duration: 24 years). Mean seizure number/month at onset was 19.3. At baseline, patients had tried a mean of 8.3 antiepileptic drugs (AEDs) and half were taking ≥3 concomitant AEDs. 31% of patients had a comorbid psychiatric condition. At 3 months, with a mean perampanel dose of 5.4 mg, 9% of patients were seizure-free and 44% were responders (≥50% reduction in seizure number). Adverse events were reported by 41.4% of patients; most frequent were irritability (13.5%), somnolence (10.8%) and dizziness (9.9%). Irritability and aggressiveness were more frequent if patients had a comorbid psychiatric condition – personality disorder/hyperactivity. Preliminary results at 3 months in refractory POS patients receiving adjunctive perampanel in a real-life setting showed a promising response. Study sponsors: Eisai Inc. Writing support: Choice Healthcare Solutions; funding, Eisai Ltd.

Synthetic peptides for the immunodiagnosis of hepatitis A virus infection

VP1, VP2 and VP3 molecules of hepatitis A virus are exposed capsid proteins that have shown to be antigenic and are used for diagnosis in recombinant-antigen commercial kits. In this study, we developed a sequence analysis in order to predict diagnostic peptide epitopes, followed by their spot synthesis on functionalized cellulose paper (Pepscan). This paper with synthetic peptides was tested against a sera pool of hepatitis A patients. Two peptide sequences, that have shown an antigenic recognition, were selected for greater scale synthesis on resin. A dimeric form of one of these peptides (IMT-1996), located in the C-Terminus region of protein VP1, was antigenic with a recognition frequency of 87-100% of anti-IgG antibodies and 100% of anti-IgM antibodies employing the immunological assays MABA and ELISA. We propose peptide IMT-1996, with less than twenty residues, as a cheaper alternative for prevalence studies and diagnosis of hepatitis A infection.

Prognosis of status epilepticus (SE): Relationship between SE duration and subsequent development of epilepsy

In animal models, SE duration is related to epileptogenesis. Data in humans are scarce, mainly in NCSE; therefore, we aimed to study the prognosis of SE de novo and which factors may influence subsequent development of epilepsy.

METHODS

We evaluated patients with SE without previous epilepsy at our hospital (February 2011-February 2014), including demographics, etiology, number of AEDs, duration of SE, mortality, and occurrence of seizures during follow-up.

RESULTS

Eighty-nine patients were evaluated. Median age was 69 (19-95) years old. Among them, 33.7% were convulsive. Regarding etiology, 59 were considered acute symptomatic (41 lesions, 18 toxic-metabolic), 17 remote or progressive symptomatic, and 13 cryptogenic. The median recovery time was 24h (30 min-360 h). In-hospital mortality was 29% (n = 26). After a median follow-up of 10 months, 58.7% of survivors (n = 37) showed seizures. Subsequently, we analyzed which factors might be related to the development of epilepsy, and we found that epilepsy development was more frequent with longer SE duration (37 vs. 23 h, p = 0.004); furthermore, patients with a toxic-metabolic etiology developed epilepsy less frequently (33% vs. 67%; p = 0.022). Epilepsy was also correlated (tendency) with focal SE (p = 0.073), a lesion in neuroimaging (p = 0.091), and the use of 2 or more AEDs (p = 0.098). Regarding SE duration, a cutoff of above 24h was clearly related to chronic seizures (p = 0.014); however, combining etiology and duration, the association of longer SE and epilepsy was significant in acute lesional SE (p = 0.034), but not in epilepsy with cryptogenic or remote/progressive etiology. After a logistic regression, only a duration longer than 24h (OR = 3.800 (1.277-11.312), p = 0.016) was found to be an independent predictor of the development of epilepsy.

CONCLUSION

In patients with SE, the longer duration is associated with an increased risk of subsequent epilepsy at follow-up, mainly in symptomatic SE due to an acute lesion. It is unclear if it might be the result of a more severe injury causing both prolonged seizures and subsequent epilepsy, and therefore whether more aggressive treatment in this group might avoid this possibility. Most of the patients with cryptogenic or remote/progressive SE developed epilepsy regardless of SE duration. This article is part of a Special Issue entitled "Status Epilepticus".

Long-term decline of the Amazon carbon sink

Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.

Markedly divergent estimates of Amazon forest carbon density from ground plots and satellites

AIM

The accurate mapping of forest carbon stocks is essential for understanding the global carbon cycle, for assessing emissions from deforestation, and for rational land-use planning. Remote sensing (RS) is currently the key tool for this purpose, but RS does not estimate vegetation biomass directly, and thus may miss significant spatial variations in forest structure. We test the stated accuracy of pantropical carbon maps using a large independent field dataset.

LOCATION

Tropical forests of the Amazon basin. The permanent archive of the field plot data can be accessed at: http://dx.doi.org/10.5521/FORESTPLOTS.NET/2014_1.

METHODS

Two recent pantropical RS maps of vegetation carbon are compared to a unique ground-plot dataset, involving tree measurements in 413 large inventory plots located in nine countries. The RS maps were compared directly to field plots, and kriging of the field data was used to allow area-based comparisons.

RESULTS

The two RS carbon maps fail to capture the main gradient in Amazon forest carbon detected using 413 ground plots, from the densely wooded tall forests of the north-east, to the light-wooded, shorter forests of the south-west. The differences between plots and RS maps far exceed the uncertainties given in these studies, with whole regions over- or under-estimated by > 25%, whereas regional uncertainties for the maps were reported to be < 5%.

MAIN CONCLUSIONS

Pantropical biomass maps are widely used by governments and by projects aiming to reduce deforestation using carbon offsets, but may have significant regional biases. Carbon-mapping techniques must be revised to account for the known ecological variation in tree wood density and allometry to create maps suitable for carbon accounting. The use of single relationships between tree canopy height and above-ground biomass inevitably yields large, spatially correlated errors. This presents a significant challenge to both the forest conservation and remote sensing communities, because neither wood density nor species assemblages can be reliably mapped from space.

Long-term safety and efficacy of eslicarbazepine acetate in patients with focal seizures: results of the 1-year ESLIBASE retrospective study

BACKGROUND

Eslicarbazepine acetate (ESL) is a new antiepileptic drug (AED) licensed as adjunctive therapy in adults with partial-onset or focal seizures.

OBJECTIVE

To evaluate in a clinical practice setting the long-term efficacy and safety of ESL in patients with focal seizures.

METHODS

ESLIBASE was a retrospective study that included all patients with focal seizures who started ESL between January 2010 and July 2012 at 12 hospitals. ESL was prescribed individually according to real-life practice. Efficacy and safety were evaluated over 1 year. Switching from carbamazepine (CBZ) and oxcarbazepine (OXC) was assessed.

RESULTS

Three hundred and twenty-seven patients were included; 78% of patients were taking ≥2 other AEDs at baseline. Most (87%) began ESL because of poor seizure control and 13% because of adverse events (AEs) with CBZ or OXC. After 1 year, 237 patients (72.4%) remained on ESL. At 3, 6 and 12 months, the responder rate was 46.3%, 57.9%, and 52.5%, and 21.0%, 28.0%, and 25.3% of patients were seizure free. The responder rate significantly increased when ESL was combined with a non-sodium channel-targeting drug (non-SC drug) (66.7%) versus an SC drug (47.7%; p<0.001). At 12 months, 40.7% of patients had ≥1 AE; AEs led to treatment discontinuation in 16.2%. Dizziness, nausea, and somnolence were the most common AEs. The tolerability profile improved in >50% of the patients who switched from CBZ or OXC to ESL because of AEs.

CONCLUSIONS

ESL was well tolerated and effective in a real-world setting over 1 year. Side-effect profile improved when OXC and CBZ recipients were switched to ESL.

Fast demographic traits promote high diversification rates of Amazonian trees

The Amazon rain forest sustains the world's highest tree diversity, but it remains unclear why some clades of trees are hyperdiverse, whereas others are not. Using dated phylogenies, estimates of current species richness and trait and demographic data from a large network of forest plots, we show that fast demographic traits – short turnover times – are associated with high diversification rates across 51 clades of canopy trees. This relationship is robust to assuming that diversification rates are either constant or decline over time, and occurs in a wide range of Neotropical tree lineages. This finding reveals the crucial role of intrinsic, ecological variation among clades for understanding the origin of the remarkable diversity of Amazonian trees and forests.

Hyperdominance in the Amazonian tree flora

The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.4%) account for half of all trees. Most of these are habitat specialists and only dominant in one or two regions of the basin. We discuss some implications of the finding that a small group of species--less diverse than the North American tree flora--accounts for half of the world's most diverse tree community.

Differential growth responses to water balance of coexisting deciduous tree species are linked to wood density in a Bolivian tropical dry forest

A seasonal period of water deficit characterizes tropical dry forests (TDFs). There, sympatric tree species exhibit a diversity of growth rates, functional traits, and responses to drought, suggesting that each species may possess different strategies to grow under different conditions of water availability. The evaluation of the long-term growth responses to changes in the soil water balance should provide an understanding of how and when coexisting tree species respond to water deficit in TDFs. Furthermore, such differential growth responses may be linked to functional traits related to water storage and conductance. We used dendrochronology and climate data to retrospectively assess how the radial growth of seven coexisting deciduous tree species responded to the seasonal soil water balance in a Bolivian TDF. Linear mixed-effects models were used to quantify the relationships between basal area increment and seasonal water balance. We related these relationships with wood density and sapwood production to assess if they affect the growth responses to climate. The growth of all species responded positively to water balance during the wet season, but such responses differed among species as a function of their wood density. For instance, species with a strong growth response to water availability averaged a low wood density which may facilitate the storage of water in the stem. By contrast, species with very dense wood were those whose growth was less sensitive to water availability. Coexisting tree species thus show differential growth responses to changes in soil water balance during the wet season. Our findings also provide a link between wood density, a trait related to the ability of trees to store water in the stem, and wood formation in response to water availability.

Efficacy of intravenous lacosamide as an add-on treatment in refractory status epilepticus: a multicentric prospective study

OBJECTIVE

Treatment of status epilepticus (SE) has not changed in the last few decades, benzodiazepines plus phenytoin or valproate being the most common treatment. Once this first and second line treatment has failed SE is considered refractory (RSE). This study aimed to assess the efficacy and tolerability of intravenous (iv) lacosamide (LCM) in RSE.

METHOD

Patients with RSE who were treated with ivLCM in six Spanish centers were prospectively included. Efficacy was defined as cessation of seizures after starting ivLCM, with no need for any further antiepileptic drug. All patients had been unsuccessfully treated following the standard protocol (benzodiazepines plus phenytoin or valproate) before ivLCM was added.

RESULTS

Thirty-four patients were included, 52.9% men, with mean age of 60.15 years. In 58.9% of patients the etiology was symptomatic, and the most common type of SE was focal convulsive (82.4%). Mean initial bolus dose of LCM was 323.53mg. ivLCM was effective in more than half of patients (64.7%), with termination of SE before 12h in 50% of them. ivLCM was used as a fourth or later option in 76.5% of patients. No serious adverse events attributable to LCM were reported.

CONCLUSIONS

LCM might be a fast, effective and safe add-on treatment in RSE.

[A study of right-left shunt in transient global amnesia]

INTRODUCTION

Transient global amnesia (TGA) is a disorder of unknown aetiology. In recent studies, TGA was associated with a right to left shunt (RLS). We studied the presence of the RLS in patients with TGA and we compared this series with patients who had suffered a transient ischaemic attack (TIA).

PATIENTS AND METHODS

We included 66 consecutive TGA patients. In these patients a transcranial Doppler was performed to determine the presence of a RLS. We collected data on the TGA episode, vascular risk factors, migraine history, recurrence of TGA and neuroimaging in patients with and without RLS. We compared the prevalence of the RLS in TGA series with 59 patients with TIA.

RESULTS

The prevalence of RLS was 21.2% in patients with TGA. The RLS was associated with the migraine history (40% versus 13%; p = 0.014) and a Valsalva manoeuvre as a triggering factor (50% versus 14.5%; p = 0.022). A greater prevalence of RLS was detected in patients with TIA (55.9% versus 21.2%; p < 0.001).

CONCLUSIONS

The RLS prevalence in TGA patients is similar to the general population but significantly lower than the prevalence in TIA patients. The association with a Valsalva manoeuvre as a precipitating factor in the TGA patients with RLS could play a role in the aetiopathogenesis of the TGA.

[Design and implementation of a national serum bank for the surveillance of exotic animal diseases in the Republic of Cuba]

A serum bank for the surveillance of exotic diseases was designed in accordance with the provisions of the Information and Epizootiological Surveillance System in the Republic of Cuba. Sera were collected from imported animals, from sentinel animals used for monitoring target areas at biological risk and from animals located in high animal-density areas. Methodologies were developed for the selection and characterisation of target areas at biological risk and sentinel animal points, the collection and storage of serum samples and the management of the national animal serum bank. After developing the methodologies, the serum bank was established throughout Cuba. The national animal serum bank operates using a quality management system based on the recommendations of the World Organisation for Animal Health and the International Organization for Standardization.

[Polycythaemia as a ready factor of transitory global amnesia]

Transitory global amnesia (TGA) is an upheaval where the patient has anterograde memory lost of abrupt beginning and an inferior duration to 24 h, that has been related to ischaemic, epileptogenic and migranous ethiology. On the other hand polycythaemia is classified like a prothrombotic disorder that can produce manifold manifestations in the central nervous system, from strokes to psychiatric disturbances of anxious type, and all related to the secondary cerebral hipoperfusión due to hyperviscosity. Two patients, who had a previous diagnostic of polycythaemia suffered an episode of TGA, in addition in one of the two cases a cerebellar hemangioblastoma was found. There are numerous cases reported of brain tumors and other CNS findings diagnosed as a result of an episode of TGA, nevertheless on has not described to the relation between polycythaemia and the TGA. In the TGA a hypoperfusion of the temporal brain hemisphere has been documented and this can be a leading mechanism, so we propose that polycythaemia could ready to suffer a TGA.

Safety Assessment of the Conversion From Mycophenolate Mofetil to Enteric-Coated Mycophenolate Sodium in Stable Renal Transplant Recipients

The immunosuppressant mycophenolate mofetil (MMF; CellCept) has greatly improved transplant recipients' clinical outcomes, but its efficacy may be limited by dose adjustments due to adverse events (AEs). An enteric-coated formulation of mycophenolate sodium (EC-MPS; myfortic), designed to improve gastrointestinal tolerability is now available. This Latin-American, prospective, multicenter, open-label, 6-month trial assessed the safety and tolerability of converting renal transplant recipients from MMF to EC-MPS. In total, 237 renal transplant recipients (stable > or = 3 months' posttransplant) receiving MMF (< or =1000 mg b.i.d.) were enrolled. Adults (n = 218) were converted to EC-MPS 720 mg b.i.d. (equimolar to MMF 1000 mg b.i.d.) even if they were initially receiving <1000 mg MMF b.i.d. (ie, 47 adults received a higher than equimolar dose of EC-MPS). Children (n = 19) were converted to EC-MPS 450 or 432 mg/m2 b.i.d. Patients also received cyclosporine microemulsion (Neoral) and corticosteroids. There were three acute rejections and no graft failures. The incidence of AEs was 59.9% (in those receiving a higher than equimolar EC-MPS dose it was 57.4%). In all, 22% of patients had gastrointestinal AEs, 37% had infections, and 4.8% had hematological AEs. Only 24 patients (10%) had an AE-related dose reduction. Seven of these patients had received higher than equimolar doses of EC-MPS. Patients can be safely converted from different doses of MMF to a standard dose of EC-MPS. The requirement for EC-MPS dose reduction to manage AEs was relatively low. Use of EC-MPS is a valid alternative for renal transplant recipients receiving maintenance MMF treatment.

Stable renal transplant recipients can be safely converted from MMF to enteric-coated mycophenolate sodium tablets: Interim results of a multicenter Latin American study

Enteric-coated mycophenolate sodium (EC-MPS) is designed to reduce mycophenolate acid (MPA)-related upper gastrointestinal (GI) adverse events (AEs). A multicenter, open-label, Latin American study in stable renal transplant patients is ongoing to assess the safety of the conversion from mycophenolate mofetil (MMF) to EC-MPS. An interim analysis was performed when 93 patients had completed 3 months. Prior to conversion, they had received MMF at a dose of 2 g/d, with the exception of eight adult patients who were receiving an average daily dose of 1.25 g. All adult patients were converted to EC-MPS (1.44 g/d; 0.450 g/m(2) bid for children). After conversion, the reported total incidence of AEs was 40.9%, including 28% infections, 1.1% hematologic, 19.4% GI, including 10.8% upper-GI AE (all mild) and 5.4% diarrhea. No patient discontinued the study medication due to adverse events. Only six patients (6%) required a dose adjustment. There were no episodes of acute rejection, death, or graft loss. During the period of analysis, the conversion from MMF to EC-MPS was safe, the enteric-coated tablet formulation prevented release of MPA in the upper GI tract, and only one patient had to reduce the dose due to an upper GI AE, concomitant with diarrhea. EC-MPS offers transplant physicians and their patients an alternative MPA therapy that is as effective and safe as MMF, but in a formulation that may provide GI tolerability benefits.

Tracing sewage in the marine environment: altered signatures in Concepción Bay, Chile

Lipid biomarkers are now widely used to trace organic matter in the marine environment. Selected compounds and ratios can be used to identify sources or processes. However, in a study of a particularly contaminated area, the expected signatures were not found (Mudge and Seguel, Bol. Soc. Chil. Quím. 42 (1997) 5). This site has been re-examined to determine why they were absent. The concentrations of sterols, fatty acids and alcohol biomarkers of 10 sediment cores from Concepción Bay, Chile, were quantified by capillary gas chromatography-mass spectrometry. The data obtained from 34 fatty acids, 28 fatty alcohols (C12-C30) and 32 sterols from the target study area, indicated that fatty acids from Concepción Bay sediments were the most abundant lipids (range 1.6-307 microg g(-1) dry wt) followed by sterols (range 0.02-25.3 microg g(-1) drywt). The sewage markers 5beta-coprostanol and epi-coprostanol were found in the areas close to the Penco-Lirquen disposal pipe. High bacterial activity was also present as indicated by the cholestanol, 18:1omega7, iso, anteiso and branched fatty acids and enhanced odd/even ratios of fatty alcohol biomarkers. The sediments from the centre of Concepción Bay had a greater marine/algal input characterized by brassicasterol and the marine fatty acids (20:4omega6, 20: 5omega3 22: 6omega3). The terrestrial contribution was mainly characterized by beta-sitosterol, C22-C26 fatty acids and confirmed by short/long chain ratio of the fatty alcohols. The distribution of these two markers indicates that the terrestrial matter passing through the sewage system is deficient in short chain fatty alcohols. The epi-coprostanol/coprostanol versus coprostanol/cholesterol plots also indicated selected removal of the stanols leaving apparently high cholesterol concentrations.

[Tuberculous meningitis in review]

Tuberculosis meningitis is one of the most dangerous forms of tuberculosis (TB). Due to large waves of immigration, the incidence of TB in Israel has increased in recent years, as has that of TB meningitis. Due to its high mortality, rapid diagnosis of TB meningitis is of paramount importance. We present a patient admitted with a acute febrile disease which was subsequently diagnosed as TB meningitis.

Enzyme-histochemical profiles of fiber types in mature canine appendicular muscles

The histochemical characteristics of skeletal muscle were assessed using a range of samples from 7 appendicular muscles taken from adult mixed-breed dogs (1.5 to 3 years of age). Two slow-twitch fiber subtypes (IA and IB) and three II subtypes (IIA, IIB and IIC) were identified according to myofibrillar myosin adenosine triphosphatase reaction after acid and alkaline preincubation. Type IIB fibers were not found in all muscles, and were only biologically significant in m. semitendinosus. The metabolic potential of these fibers is fairly similar to that of IIA fibers, but significantly different to that of IIB fibers in other mammals, suggesting that they may be designed to play a different functional role during locomotion. All canine muscle fibers have moderate to high oxidative capacity, which may be related to the extraordinary athletic capability of the species.

[A modified Strout test, used as a probe for the diagnosis of transplacental Chagas disease. I. Collection and preservation of the newborn's umbilical cord blood]

Two umbilical cord (UC) blood samples are routinarily taken from each newborn (NB) at the University of Chile Maternity Hospital, to determine blood grouping and for detecting syphilis infection respectively. In august-september 1993, an additional UC blood sample was collected from each of 116 NB (with volumes of whole blood ranging 2.7 - 24.5 ml and a mean of 13.5 ml). In order to determine the persistence of the mobility of Trypanosoma cruzi in blood samples stored at three different temperatures (-2 to -4 degrees C, 4 to 6 degrees C and environmental temperature from 16 to 23 degrees C), two experiments were performed: 1) In three centrifuge microtubes mouse blood (C3H strain) abundant T. cruzi trypomastigotes Tulahuen strain were put. 2) In an other similar number of microtubes, with the same concentration of parasites, human serum from UC was added. During the first 12 h in all the samples trypomastigotes with very active mobility were observed. At 72 h mobility persisted in samples with temperature between 4 and 6 degrees C and between 16 and 23 degrees C. Whereas in the samples maintained at -2 to -4 degrees C with parasites in blood plus serum, an important decrease of T. cruzi mobility was observed. The results of this study suggest that UC blood samples could be collected and maintained between 4 and 6 degrees C or at room temperature up to 48 h to be processed by the modified Strout concentration method (MSCM).(ABSTRACT TRUNCATED AT 250 WORDS)

[ABO materno-fetal incompatibility in the newborn infant: clinical usefulness of Coombs test and elution for the study of hemolytic disease]

A decision to establish early treatment for hemolytic disease in the newborn is usually based upon results of the Coombs test. In order to evaluate a possible advantage of using the Elution test to help in the diagnosis of the hemolytic state, samples of cord blood from 197 consecutive newborns with ABO incompatibility were studied. Hemolysis occurred in 41. Each test (Coombs and Elution) was positive in 26 patients, for a total of 35 positive results and a combined sensitivity of 85%. False positives occurred in 24 of 156 patients with Coombs test and in 30 for the Elution test. Thus, combined results of both test would have suggested a need for phototherapy in 72 of 197 patients when in fact it was needed for only 41. Conversely, 13 patients with hemolytic disease were missed by both tests. The negative predictive value of both tests combined was 95% which is useful for clinical practice.