A cold wave of winter 2021 in central South America: characteristics and impacts.

During the austral winter (June-August) of 2021, the meteorological services of Brazil, Argentina, Peru, Paraguay, Bolivia, and Chile all issued forecasts for unusually cold conditions. Record-low minimum temperatures and cold spells were documented, including one strong cold wave episode that affected 5 countries. In this study, we define a cold wave as a period in which daily maximum and minimum air temperatures are below the corresponding climatological 10th percentile for three or more consecutive days. The intense cold wave event in the last week of June, 2021, resulted in record-breaking minimum daily temperatures in several places in central South America and Chile. Several locations had temperatures about 10 °C below average, central South America had freezing conditions, and southern Brazil even saw snow. The cold air surge was characterized by an intense upper-air trough located close to 35° S and 70° W. The southerly flow to the west of this trough brought very cold air northward into subtropical and tropical South America. A northward flow between the lower-level cyclonic and anticyclonic perturbations caused the intense southerly flow between the upper-level ridge and trough. This condition facilitated the inflow of near-surface cold air from southern Argentina into southeastern Brazil and tropical South America east of the Andes. In the city of São Paulo, the cold wave caused the death of 13 homeless people from hypothermia. Frost and snow across southern and southeastern Brazil caused significant damage to coffee, sugarcane, oranges, grapes, and other fruit and vegetable crops. Wine and coffee production fell, the latter by 30%, and prices of food and commodities in the region rose. Supplementary Information: The online version contains supplementary material available at 10.1007/s00382-023-06701-1.

Prediction of extreme floods in the eastern Central Andes based on a complex networks approach.

Changing climatic conditions have led to a significant increase in the magnitude and frequency of extreme rainfall events in the Central Andes of South America. These events are spatially extensive and often result in substantial natural hazards for population, economy and ecology. Here we develop a general framework to predict extreme events by introducing the concept of network divergence on directed networks derived from a non-linear synchronization measure. We apply our method to real-time satellite-derived rainfall data and predict more than 60% (90% during El Niño conditions) of rainfall events above the 99th percentile in the Central Andes. In addition to the societal benefits of predicting natural hazards, our study reveals a linkage between polar and tropical regimes as the responsible mechanism: the interplay of northward migrating frontal systems and a low-level wind channel from the western Amazon to the subtropics.

Avances en la cirugía de la disrrafia espinal en el Instituto de Neurocirugía de Chile: el uso del neuromonitoreo mejora radicalmente los resultados quirúrgicos / Advances in spinal dysraphism surgery at the Institute of Neurosurgery of Chile: the use of neuromonitoring radically improves surgical outcomes

El objetivo del tratamiento quirúrgico de los pacientes aquejados de disrrafia espinal es mantener su función neurológica estable y óptima durante toda su vida, sin embargo, existe un riesgo importante implícito en la cirugía. Con el objeto de investigar el impacto del monitoreo electrofisiológico intraoperatorio (MIO) en la evolución postoperatoria de estos pacientes, el cirujano practicó electromiografía libre y estimulada como retroalimentación continua del procedimiento. Las patologías operadas fueron: lipomas del fillum, lipomas del cono medular y re-anclajes de pacientes portadores de mielomeningocele al nacer. En todas las patologías se comparó la evolución post-operatoria con grupos de pacientes operados sin MIO, con el objeto de comparar sus evoluciones. Se observaron diferencias significativas entre los tres grupos de pacientes el uso de MIO evita el deterioro motor y la aparición de vejiga neurogénica en pacientes operados de lipoma del cono, evita la inclusión de raíces nerviosas en la sección del Fillum y evita el deterioro motor y ayuda a mejorar la función vesical de pacientes que se operan por re-anclaje medular por mielomeningocele. Finalmente, fue posible aplicar esta técnica en recién nacidos con mielomeningocele bajo, desarrollándose un protocolo que evita de facto el deterioro motor y debería evitar la inclusión de piel durante la tunelización de la placoda. Los datos mostrados en el presente trabajo permiten afirmar que esta técnica, por primera vez desarrollada en el sistema público chileno, así aplicada mejora muy significativamente los resultados de la cirugía de disrrafia espinal.

[Molecular typification of Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis]. / Tipificación molecular de aislamientos de Pseudomonas aeruginosa obtenidos de pacientes con fibrosis quística.

Cystic fibrosis is the most frequent lethal genetic disease that affects the caucasian population. The main cause of morbidity is the chronic lung infection, being the infection caused by Pseudomonas aeruginosa the most difficult to eradicate. This bacteria can be acquired in direct form, by person-to-person transfer, or indirectly, by hospital acquired infection. The Centro Provincial de Referencia de Fibrosis Quistica functioning in the Hospital de Niños "Sor María Ludovica", in La Plata, cares almost 220 patients aged two months to 45 years. The life expectancy depends of factors like the early diagnosis of the disease and the later acquisition of the chronic lung infection. The purpose of this work was the molecular typing of P. aeruginosa isolates obtained from cystic fibrosis patients to evaluate the genomic relationship among them. The study was carried out using RAPD-PCR. The analysis showed a great genetic heterogeneity among the isolates. The separation of the patients in groups in accordance with its bacteriology, that implies the attendance in different days and the implementation of isolation (or segregation) measures had demonstrated to be, in addition to other strategies, effective in the reduction of cross infections.

[Differentiating early dementia from major depression with the Spanish version of the Addenbrooke's Cognitive Examination]. / Diferenciación entre demencias en estadio inicialy depresión utilizando la versión españoladel Addenbrooke's Cognitive Examination.

INTRODUCTION: In clinical practice it is often difficult to establish whether cognitive impairment is secondary to an affective disorder or a dementing process. AIM: To describe the cognitive performance on the Spanish version of the Addenbrooke's Cognitive Examination (ACE) of patients with early dementia and depression. SUBJECTS AND METHODS: 77 patients with early dementia (53 Alzheimer disease; 24 frontotemporal dementia), 17 patients with major depression and 54 healthy volunteers were tested with the Spanish version of the ACE. RESULTS: Alzheimer disease and frontotemporal dementia groups were significantly lower than the control group and the major depression group. When the major depression group was compared with the control group no significant differences were found. CONCLUSIONS: The cognitive performance in the ACE is different in patients with early dementia and patient with depression.

Tipificación molecular de aislamientos de Pseudomonas aeruginosa obtenidos de pacientes con fibrosis quística / Molecular typification of Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis

La fibrosis quística es la enfermedad genética letal de mayor frecuencia en la población caucásica. La infección pulmonar crónica es la principal causa de morbilidad de la enfermedad, siendo la infección por Pseudomonas aeruginosa la más importante, ya que resulta de difícil erradicación. El Centro de Referencia Provincial de Fibrosis Quística que funciona en el Hospital de Niños "Sor María Ludovica" de La Plata asiste a alrededor de 220 pacientes con fibrosis quística cuyas edades oscilan entre los dos meses y los 45 años. La edad de sobrevida depende de una serie de factores entre los que se encuentran el diagnóstico temprano de la enfermedad y la adquisición de la infección pulmonar crónica por P. aeruginosa. La misma puede adquirirse en forma directa, por transmisión persona a persona o de forma indirecta a través del uso de elementos hospitalarios contaminados. El objetivo de este trabajo fue la tipificación molecular de aislamientos de P. aeruginosa obtenidos de pacientes con fibrosis quística, con el fin de evaluar la relación genómica entre los mismos. El estudio se llevó a cabo mediante RAPD-PCR. El análisis demostró que existe gran heterogeneidad genética entre los aislamientos. La separación en cohortes de pacientes de acuerdo con su bacteriología, que implica la asistencia en días diferentes y las hospitalizaciones en habitaciones aisladas ha demostrado, junto a otras estrategias, disminuir las infecciones cruzadas.

Cystic fibrosis is the most frequent lethal genetic disease that affects the caucasian population. The main cause of morbidity is the chronic lung infection, being the infection caused by Pseudomonas aeruginosa the most difficult to eradicate. This bacteria can be acquired in direct form, by person-to-person transfer, or indirectly, by hospital acquired infection. The Centro Provincial de Referencia de Fibrosis Quística functioning in the Hospital de Niños "Sor María Ludovica", in La Plata, cares almost 220 patients aged two months to 45 years. The life expectancy depends of factors like the early diagnosis of the disease and the later acquisition of the chronic lung infection. The purpose of this work was the molecular typing of P. aeruginosa isolates obtained from cystic fibrosis patients to evaluate the genomic relationship among them. The study was carried out using RAPD-PCR. The analysis showed a great genetic heterogeneity among the isolates. The separation of the patients in groups in accordance with its bacteriology, that implies the attendance in different days and the implementation of isolation (or segregation) measures had demonstrated to be, in addition to other strategies, effective in the reduction of cross infections.

Diferenciación entre demencias en estadio inicial y depresión utilizando la versión española del Addenbrooke’s Cognitive Examination / Differentiating early dementia from major depression with the Spanish version of the addenbrooke’s cognitive examination

La diferenciación entre cuadros demenciales iniciales y la expresión cognitiva de los trastornos anímicoses fundamental en la práctica clínica, tanto de especialistas en trastornos cognitivos como en la de médicos generalistas. Objetivo. Investigar el perfil cognitivo en la versión en español del test de cribado cognitivo Addenbrooke’s Cognitive Examination (ACE) en pacientes con demencias incipientes y depresión mayor. Sujetos y métodos. Se evaluó con el ACE a 77 pacientes con demencias en estadios iniciales (53 con demencia tipo Alzheimer y 24 con demencia frontotemporal), 17 pacientes con criterios de depresión mayor y 54 controles normales. Resultados. Los grupos de demencias incipientes registraron una diferencia estadísticamente significativa, no sólo en relación con el grupo control, sino también con el grupo de trastorno depresivo. Cuando el grupo de depresión se comparó con el grupo control, no se observaron diferencias significativas. Conclusiones. La versión en español del ACE es capaz de diferenciar los cambios cognitivos observados en trastornos anímicos de los que se encuentran en las demencias incipientes

In clinical practice it is often difficult to establish whether cognitive impairment is secondary to anaffective disorder or a dementing process. Aim. To describe the cognitive performance on the Spanish version of the Addenbrooke’s Cognitive Examination (ACE) of patients with early dementia and depression. Subjects and methods. 77 patients with early dementia (53 Alzheimer disease; 24 frontotemporal dementia), 17 patients with major depression and 54 healthy volunteers were tested with the Spanish version of the ACE. Results. Alzheimer disease and frontotemporal dementia groups were significantly lower than the control group and the major depression group. When the major depression group was compared with the control group no significant differences were found. Conclusions. The cognitive performance in the ACE isdifferent in patients with early dementia and patient with depression

Hydro-climate and ecological behaviour of the drought of Amazonia in 2005.

In 2005, southwestern Amazonia experienced the effects of an intense drought that affected life and biodiversity. Several major tributaries as well as parts of the main river itself contained only a fraction of their normal volumes of water, and lakes were drying up. The consequences for local people, animals and the forest itself are impossible to estimate now, but they are likely to be serious. The analyses indicate that the drought was manifested as weak peak river season during autumn to winter as a consequence of a weak summertime season in southwestern Amazonia; the winter season was also accompanied by rainfall that sometimes reached 25% of the climatic value, being anomalously warm and dry and helping in the propagation of fires. Analyses of climatic and hydrological records in Amazonia suggest a broad consensus that the 2005 drought was linked not to El Niño as with most previous droughts in the Amazon, but to warming sea surface temperatures in the tropical North Atlantic Ocean.

Improved outcome in high-grade aneurysmal subarachnoid hemorrhage by enhancement of endogenous clearance of cisternal blood clots: a prospective study that demonstrates the role of lamina terminalis fenestration combined with modern microsurgical cisternal blood evacuation.

INTRODUCTION: Cisternal and ventricular blood predisposes to hydrocephalus and cerebral ischemia after high-grade aneurysmal subarachnoid hemorrhage (HGSAH). We studied the role of lamina terminalis fenestration combined with cisternal blood evacuation in HGSAH. PATIENTS/MATERIALS AND METHODS: A clinical, prospective, non-randomized study of a series of HGSAH patients (Modified Fisher>or=3) treated in the acute phase was carried out. The microsurgical treatment included aneurysm clipping, cisternal blood evacuation, and fenestration of the lamina terminalis. A comparable, non-blood-cleansed, endovascular-treated group, was included as a control. Clinical results were evaluated by the Glasgow Outcome Scale (GOS). RESULTS: During a period of 30 months, 95 patients who met the selection criteria were treated by microsurgical procedures and 28 by endovascular procedures. The distribution of GOS scores was superior for the microsurgical group: good results (GOS 4-5) were obtained in 85.3%, with a mortality rate of 5.9%. By contrast, 60.3% of patients in the endovascular group achieved GOS 4-5 scores, and 15.8% died. Good results for the endovascular group correlated inversely with delay of treatment. A permanent ventriculo-peritoneal shunt was necessary in 3.2% and 7.1% of the microsurgical and endovascular groups, respectively. The incidence of cerebral infarct was 3.1% and 14.3% for the microsurgical and endovascular groups, respectively. DISCUSSION: Microsurgical management reduces the usually poor outcome of patients with HGSAH. Lamina terminalis fenestration diminishes the incidence of shunt-dependent hydrocephalus and, combined with extensive cisternal blood cleansing, can lower the incidence of stroke. A procedure for cleansing blood and clots from the cisterns in HGSAH, based on the pathophysiology of vasospasm, is proposed.

Kainate-induced seizures alter protein composition and N-methyl-D-aspartate receptor function of rat forebrain postsynaptic densities.

The postsynaptic density is a highly dynamic structure, which is reorganized in an activity-dependent manner. An animal model for temporal lobe epilepsy, i.e. kainate-induced limbic seizures in rats, was used to study changes in postsynaptic density composition after extensive synaptic activity. Six hours after kainate injection, the protein content of the postsynaptic density fractions from rats that developed strong seizures was increased three-fold compared to saline-treated controls. Immunoblot analysis revealed that the relative amounts of metabotropic glutamate receptor 1alpha, N-ethylmaleimide-sensitive fusion protein, protein kinases C, Fyn and TrkB, as well as the neuronal nitric oxide synthase, were significantly higher in seizure-developing than in control rats. In contrast, the relative contents of the kainate receptor KA2 subunit, beta-actin, alpha-adducin and the membrane-associated guanylate kinase homolog SAP90/PSD-95 were decreased. The relative amounts of additional postsynaptic density proteins, including alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate and N-methyl-D-aspartate receptor subunits, calcium/calmodulin-dependent kinase type II, casein kinase 2, tubulin, microtubule-associated protein 2B, the membrane-associated guanylate kinase homolog SAP102, and proline-rich synapse-associated protein 1/cortactin binding protein 1/Shank2 remained essentially unchanged. To assess possible changes in postsynaptic performance, postsynaptic densities were isolated from control and epileptic rats, incorporated into giant liposomes and N-methyl-D-aspartate receptor currents were recorded. A significant reduction in the mean conductance was observed in patches containing postsynaptic densities from animals with high seizure activity. This was due to the presence of reduced conductance levels in each membrane patch compared to control postsynaptic density preparations. From these data, we suggest that intense synaptic activity associated with seizures modifies the composition of postsynaptic densities and has profound consequences on the function of the N-methyl-D-aspartate receptors present in them. This rearrangement may accompany impairment of synaptic plasticity.

Antiglaucomatous drugs effects on optic nerve head flow: design, baseline and preliminary report.

PURPOSE: To determine the effect of the most frequent used antiglaucomatous drugs on the optic nerve head flow. To see the response of the autoregulation system in hypertensive, preperimetric and advanced perimetric glaucomas. MATERIALS: In this preliminary report, optic nerve head parameters and retinal perfusion values were measured in 25 healthy controls as well as in 72 glaucomatous optic nerve heads. The glaucomatous sample was divided into three groups: 24 eyes treated with Betaxolol, 24 with Brinzolamide and 24 treated with Brimonidine (each of these groups was conformed by 8 hypertensive glaucomas, 8 preperimetric glaucomas, and 8 perimetric glaucomas). METHODS: Patients were examined with scanning laser Doppler flowmetry (wave length 638 nm), and flow, volume and velocity indices were assessed in each report. Perfusion maps were analyzed with the new SLDF software, version 3.2 (automatic full field perfusion image analizer). Examinations were also performed with the Heidelberg Retina Tomograph (wave length 638 nm), using the new standard reference plane. Visual fields were performed with the Octopus 123 or 101 perimeters, programs Glx and G2, with 3 phases completed. Diurnal pressure curve with applanation tonometry and gonioscopy (for classification) were also performed. RESULTS: In this preliminary report, it was found that eyes in Hypertensive or preperimetric stages of glaucoma, seem to use their regulation systems in order to preserve their optic nerve head circulation, while advanced perimetric glaucomas seem not be able to preserve their optic nerve head flow. And that antiglaucomatous drugs were not able to increase optic nerve head flow neither. DISCUSSION: Optic nerve head blood supplies is regulated by an autoregulation system. This phenomenon may act in normals, hypertensive and preperimetric glaucomas, but it seems not be able to preserve blood flow in advanced glaucomas. Optic nerve head flow returns to normal values with treatment in glaucoma first stages, while it seems that it could not be restored in advanced glaucomas.

Glaucomatous optic nerve head changes with scanning laser ophthalmoscopy.

PURPOSE: To determine whether there are angiographic differences among normal, preperimetric and advanced glaucoma eyes using indocyanine green angiography with SLO. This method was chosen because of its sensibility to detect peripapillary capillary vessels. METHODS: Scanning laser opthalmoscopy was preformed on normal eyes, preperimetric glaucomas and advanced glaucomas. MATERIAL: The authors used a confocal SLO (Heidelberg Retina Angiograph-HRA) CONCLUSION: Several changes may be seen on peripapillary capillary vessels at the different glaucomatous stages. DISCUSSION: In normal subjects HRT shows preservation of the disc/cup area ratio; indocyanine green angiography shows normal prepapillary plexus pattern on the neuroretinal rim and cup. Subjects on glaucomatous preperimetric stage reveal a decrease in the disc/cup area ratio as a result of an increase of the cup area secondary to a reduction of the neuroretinal rim area. ICG at this hipertensive stage shows an increase in prepapillary plexus visualization, which may be a consequence of increased blood flow while autoregulation is still operative. Subjects with advanced glaucoma show prominent decrease in the disc/cup area ratio as well as marked capillary droupout in ICG angiography.

A prospective longitudinal 10-year study of schizophrenia's three major factors and depression.

This study investigated the nature, independence, and stability of schizophrenia's syndrome factors and depression at 2, 4.5, 7.5 and 10 years post-index hospitalization. At the four follow-ups, 71 patients (48 with schizophrenia and 23 with schizoaffective disorder) were assessed for symptoms hypothesized to constitute the reality distortion, disorganized, and negative factors of schizophrenia. At the last three follow-ups, the patients were also assessed for symptoms of depression. Factor analyses of schizophrenia symptoms revealed more than three syndrome factors at each follow-up. Longitudinally, reality distortion was a stable and relatively independent factor. The negative syndrome was independent but was bifurcated into two dimensions, interpreted as social/emotional withdrawal and diminished movement/expressiveness. Although signs of disorganization were not unified or independent early in schizophrenia's course, speech/thought disorder, disorganized affect, and poverty of speech content coalesced to form a disorganization factor by the 7.5-year follow-up. When depressive symptoms were added to the analyses, depression constituted an independent and stable dimension of schizophrenia over time. Each schizophrenia factor demonstrated a unique longitudinal course. Courses included stable symptom consistency (reality distortion), evolving symptom convergence (disorganization), and recurrent bifurcation and symptom instability (the negative syndrome).

Lesiones cardíacas penetrantes. Una revisión desde sus orígenes históricos hasta las últimas fronteras en el nuevo milenio / Penetrating cardiac injuries. A review from its origins to the last frontiers of the new millenium

Las lesiones cardíacas penetrantes representan una de las mayores causas de muerte por motivo de la violencia urbana. La mejora de los sistemas de urgencias en los últimos años, junto con la aplicación del principio Scoop and Run son responsables de que muchos de estos pacientes lleguen in extremis a los centros urbanos de trauma. Se ha acumulado una gran experiencia en el tratamiento de estas lesiones desde los primeros intentos de reparación de heridas cardíacas por parte de Cappelen, Farina, Rehn y Hill. La mejora y el perfeccionamiento de las técnicas originales descritas por Beck han llevado a la aparición de numerosos artículos en la bibliografía que describen el tratamiento de dichas lesiones. El conocimiento de que una intervención rápida mejora los resultados nos conduce a la era de la toracotomía en el departamento de urgencias, la vanguardia en los cuidados del trauma, ofreciendo a muchos de estos pacientes la posibilidad de sobrevivir, algo que de otra manera no ocurriría. Se han descrito distintas técnicas de reparación de heridas auriculares y ventriculares, que están en continua revisión. Cada vez más, el empleo de biomateriales como el Teflón adquiere un papel más relevante en la bibliografía, aun a sabiendas de que no existen pruebas de que estas prótesis mejoren la curación y los resultados de las lesiones cardíacas. En las dos últimas décadas, aproximadamente, en la bibliografía inglesa se han descrito unas 30 series de pacientes con heridas cardíacas penetrantes. El análisis de estas series revela que la mayoría de las mismas se componen de estudios retrospectivos y que algunos datos proceden de centros que tratan unos 15 casos de lesiones cardíacas cada año y, además, muchos de estos datos son recopilatorios. Los altos porcentajes de supervivencia que aparecen en artículos recientes tienden a crear una impresión errónea de que la mortalidad por lesiones cardíacas ha disminuido significativamente, cuando esto no es así. En una revisión reciente de la bibliografía desde 1951 a 1986, la mortalidad media por heridas de arma blanca cardíacas era del 16,3 por ciento y por heridas por arma de fuego, en el mismo período de tiempo, del 36 por ciento. Coincidimos en el porcentaje referido para las heridas de arma blanca, pero creemos que la mortalidad comunicada para las heridas por arma de fuego es significativamente baja. Un porcentaje de mortalidad más aceptable fluctuaría entre el 70 y el 80 por ciento de estas lesiones. Creemos que están apareciendo en el horizonte nuevas áreas de investigación, áreas como el impacto de la resucitación prehospitalaria y el tiempo de transporte, así como la posibilidad de la intubación prehospitalaria, que han mejorado los resultados. El uso de la ventana pericárdica subxifoidea en comparación con la nueva modalidad de ecocardiografía 2-D debe ser investigado científica y prospectivamente antes de su abandono prematuro. El papel de la toracotomía en el departamento de urgencias ha sido recientemente cuestionado por algunos autores que opinan que dicha técnica debería desempeñar un papel menos importante en el tratamiento de las lesiones cardíacas. Estos autores citan la ausencia de signos vitales como una contraindicación absoluta para la realización de dicho procedimiento, por la posibilidad potencial de contagio de enfermedades como el sida, y porque el coste del procedimiento no se corresponde con el porcentaje de vidas salvadas. Quizás el desarrollo de estudios científicos prospectivos, como los llevados a cabo por nuestro grupo, aportaría una mejor definición de cuáles son las formas más adecuadas de tratamiento de estas lesiones para establecer un diagnóstico temprano y un tratamiento correcto. Más importante todavía es el análisis estadístico de los factores que influyen en la resucitación inicial de los pacientes con heridas cardíacas. La inclusión de elementos cardiovasculares y respiratorios en los sistemas de puntuación del trauma puede establecer una mejor predicción y, por tanto, una forma más acertada de selección de pacientes subsidiarios de procedimientos agresivos de resucitación, incluyendo la toracotomía en el departamento de urgencias y la cardiorrafia. La probabilidad de éxito en estos procedimientos de resucitación está significativamente relacionada con el mecanismo del trauma, así como con el estado fisiológico del paciente cuando llega al departamento de urgencias.En resumen, deben investigarse científicamente muchos principios y deben identificarse mejores factores de predicción de resultados para excluir a los pacientes que no se beneficiarían de la utilización de estas medidas de resucitación agresiva y diferenciarlos de otros pacientes cuya supervivencia mejoraría significativamente (AU)

Operative management and outcome of 302 abdominal vascular injuries.

BACKGROUND: Abdominal vascular injuries incur high mortality rates. The purposes of this study are (1) review institutional experience, (2) determine additive effect on mortality of multiple vessel injuries, (3) determine mortality of combined arterial and venous injuries, and (4) correlate mortality with American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS) for abdominal vascular injury. METHODS: A retrospective 6-year study was made at an urban level I trauma center of patients with abdominal vascular injuries. Main outcome measure was survival. RESULTS: (1) There was a total of 302 patients, mean age 28, mean Injury Severity Score (ISS) 25 (range 4 to 75). Mechanism of injury was penetrating in 266 (88%), blunt in 36 (12%). Emergency Department thoracotomy was done in 43 of 302 (14%), 504 vessels were injured: arteries 238(47%), veins 266(53%). Surgical management was ligation 245, primary repair 141, prosthetic interposition grafts 24, autogenous 2. Overall mortality was 162 of 302 (54%). (2) Mortality multiple vessels injured: 1 vessel 160 (45%), 2 vessels 102 (60%), 3 vessels 33 (73%), >4 vessels 5 (100%). Mortality arterial injuries: aorta isolated (I) 78% versus combined with other arterial injuries (C) 82.4%, superior mesenteric artery (SMA) I 47.6% versus C 71.4%, iliac I 53% versus C 72.7%, renal I 37.5% versus C 66.7%. Venous injuries: inferior vena cava (IVC) isolated (I) 70% versus combined with other venous injuries (C) 77.7%, superior mesenteric vein (SMV) I 52.7% versus C 65%, IMV I 16% versus C 50%. (3) Specific mortality combined arterial and venous injuries: aorta plus IVC 93%, SMA plus SMV 43%, iliac artery plus vein 45.5%. (4) Mortality versus AAST-OIS: grade II 25%, grade III 32%, grade IV 65%, grade V 88%. CONCLUSION: Abdominal vascular injuries are highly lethal. Multiple arterial and venous injuries increase mortality. Mortality correlates with AAST-OIS for abdominal vascular injury.

SH oxidation stimulates calcium release channels (ryanodine receptors) from excitable cells.

The effects of redox reagents on the activity of the intracellular calcium release channels (ryanodine receptors) of skeletal and cardiac muscle, or brain cortex neurons, was examined. In lipid bilayer experiments, oxidizing agents (2,2'-dithiodipyridine or thimerosal) modified the calcium dependence of all single channels studied. After controlled oxidation channels became active at sub microM calcium concentrations and were not inhibited by increasing the calcium concentration to 0.5 mM. Subsequent reduction reversed these effects. Channels purified from amphibian skeletal muscle exhibited the same behavior, indicating that the SH groups responsible for modifying the calcium dependence belong to the channel protein. Parallel experiments that measured calcium release through these channels in sarcoplasmic reticulum vesicles showed that following oxidation, the channels were no longer inhibited by sub mM concentrations of Mg2+. It is proposed that channel redox state controls the high affinity sites responsible for calcium activation as well as the low affinity sites involved in Mg2+ inhibition of channel activity. The possible physiological and pathological implications of these results are discussed.

SH oxidation stimulates calcium release channels (ryanodine receptors) from excitable cells

The effects of redox reagents on the activity of the intracellular calcium release channels (ryanodine receptors) of skeletal and cardiac muscle, or brain cortex neurons, was examined. In lipid bilayer experiments, oxidizing agents (2,2'-dithiodipyridine or thimerosal) modified the calcium dependence of all single channels studied. After controlled oxidation channels became active at sub microM calcium concentrations and were not inhibited by increasing the calcium concentration to 0.5 mM. Subsequent reduction reversed these effects. Channels purified from amphibian skeletal muscle exhibited the same behavior, indicating that the SH groups responsible for modifying the calcium dependence belong to the channel protein. Parallel experiments that measured calcium release through these channels in sarcoplasmic reticulum vesicles showed that following oxidation, the channels were no longer inhibited by sub mM concentrations of Mg2+. It is proposed that channel redox state controls the high affinity sites responsible for calcium activation as well as the low affinity sites involved in Mg2+ inhibition of channel activity. The possible physiological and pathological implications of these results are discussed.

Traumatic injury to the superior mesenteric artery.

BACKGROUND: Superior mesenteric artery (SMA) injuries are rare and devastating injuries incurring very high mortality rates. It is the purpose of this study to review our experience with these injuries, to analyze Fullen's classification based on anatomical zone and injury grade for its predictive value, and to correlate the American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS) for abdominal vascular injury with mortality. METHODS: Retrospective study was made over a 65-month period of all patients sustaining SMA injuries in an urban level I trauma center. RESULTS: Thirty-five patients, mean age 31, had a mean Revised Trauma Score of 5.86 and a mean Injurity Severity Score of 23. Mechanisms of injury were penetrating 27 (77%) and blunt 8 (23%). Mean admission systolic blood pressure was 85 mm Hg. Mean estimated blood loss was 8,500 mL and mean total fluid replacement 17,000 mL. Operating room findings were retroperitoneal hematoma in 34 (97%) and "black bowel" in 2 (6%). Number of associated injuries was nonvascular, mean 4.2, and vascular, mean 1.5. Surgical management consisted of ligation in 18 (51%), primary repair in 14 (40%), and interposition graft in 2 (6%). Overall mortality was 19 of 35 (54%). Mortality versus Fullen's zones was zone I, 100%, zone II, 43%, and zones III and IV, 25%. Mortality versus Fullen's ischemia grade was grade 1, 89%, grade 2, 58%, grade 3, 100%, and grade 4, 19%. Mortality versus AAST-OIS: was grade 1, 0%, grade II, 20%, grade III, 0%, grade IV, 59%, and grade V, 88%. CONCLUSIONS: SMA injuries are highly lethal. Most deaths are due to exsanguination. A higher number of associated vascular injuries increases mortality. "Black bowel" is an uncommon finding. Both Fullen's anatomical zones and the AAST-OIS for abdominal vascular injuries correlate with mortality. Fullen's ischemia grade does not.

Cyclic ADP-ribose activates caffeine-sensitive calcium channels from sea urchin egg microsomes.

Adenosine 5'-cyclic diphosphoribose [cyclic ADP-ribose (cADPR)], a metabolite of NAD+ that promotes Ca2+ release from sea urchin egg homogenates and microsomal fractions, has been proposed to act as an endogenous agonist of Ca2+ release in sea urchin eggs. We describe experiments showing that a microsomal fraction isolated from Tetrapigus nyger sea urchin eggs displayed Ca(2+)-selective single channels with conductances of 155.0 +/- 8.0 pS in asymmetric Cs+ solutions and 47.5 +/- 1.1 pS in asymmetric Ca2+ solutions. These channels were sensitive to stimulation by Ca2+, ATP, and caffeine, but not inositol 1,4,5-trisphosphate, and were inhibited by ruthenium red. The channels were also activated by cADP-ribose in a Ca(2+)-dependent fashion. Calmodulin and Mg2+, but not heparin, modulated channel activity in the presence of cADP-ribose. We propose that these Ca2+ channels constitute the intracellular Ca(2+)-induced Ca2+ release pathway that is activated by cADP-ribose in sea urchin eggs.

Sulfhydryl oxidation modifies the calcium dependence of ryanodine-sensitive calcium channels of excitable cells.

The calcium dependence of ryanodine-sensitive single calcium channels was studied after fusing with planar lipid bilayers sarcoendoplasmic reticulum vesicles isolated from excitable tissues. Native channels from mammalian or amphibian skeletal muscle displayed three different calcium dependencies, cardiac (C), mammalian skeletal (MS), and low fractional open times (low Po), as reported for channels from brain cortex. Native channels from cardiac muscle presented only the MS and C dependencies. Channels with the MS or low Po behaviors showed bell-shaped calcium dependencies, but the latter had fractional open times of <0.1 at all [Ca2+]. Channels with C calcium dependence were activated by [Ca2+] < 10 microM and were not inhibited by increasing cis [Ca2+] up to 0.5 mM. After oxidation with 2,2'-dithiodipyridine or thimerosal, channels with low Po or MS dependencies increased their activity. These channels modified their calcium dependencies sequentially, from low Po to MS and C, or from MS to C. Reduction with glutathione of channels with C dependence (native or oxidized) decreased their fractional open times in 0.5 mM cis [Ca2+], from near unity to 0.1-0.3. These results show that all native channels displayed at least two calcium dependencies regardless of their origin, and that these changed after treatment with redox reagents.