Different effects of spinally applied prostaglandin D2 on responses of dorsal horn neurons with knee input in normal rats and in rats with acute knee inflammation.

Prostaglandin D2(PGD2) is the most produced prostanoid in the CNS of mammals, and in behavioral experiments it has been implicated in the modulation of spinal nociception. In the present study we addressed the effects of spinal PGD2 on the discharge properties of nociceptive spinal cord neurons with input from the knee joint using extracellular recordings in vivo, both in normal rats and in rats with acute inflammation in the knee joint. Topical application of PGD2 to the spinal cord of normal rats did not influence responses to mechanical stimulation of the knee and ankle joint except at a high dose. Specific agonists at either the prostaglandin D2 receptor 1 (DP1) or the prostaglandin D2 receptor 2 (DP2) receptor had no effect on responses to mechanical stimulation of the normal knee. By contrast, in rats with inflamed knee joints either PGD2 or a DP1 receptor agonist decreased responses to mechanical stimulation of the inflamed knee and the non-inflamed ankle thus reducing established inflammation-evoked spinal hyperexcitability. Vice versa, spinal application of an antagonist at DP1 receptors increased responses to mechanical stimulation of the inflamed knee joint and the non-inflamed ankle joint suggesting that endogenous PGD2 attenuated central sensitization under inflammatory conditions, through activation of DP1 receptors. Spinal application of a DP2 receptor antagonist had no effect. The conclusion that spinal PGD2 attenuates spinal hyperexcitability under inflammatory conditions is further supported by the finding that spinal coapplication of PGD2 with prostaglandin E2 (PGE2) attenuated the PGE2-induced facilitation of responses to mechanical stimulation of the normal joint.

[Management and predictors in patients with spontaneous intracerebral hemorrhage]. / Tratamiento e indicadores pronósticos del paciente con hemorragia intracerebral espontánea.

AIM: To review about novel aspects in the initial management of patients with spontaneous intracerebral hemorrhage (SICH) and to analyze a group of predictors with influence on the election of certain therapies and on the 30-day mortality. DEVELOPMENT: SICH often constitutes a critical illness. Thus, many SICH patients are admitted in intensive care units (ICUs) for continuous monitoring and 'appropriate' treatment. In these settings it is essential to have predictors of poor outcome to plan the level of care and to optimize resource utilization. Clinical management of these patients focuses on controlling the intracranial pressure, stopping or slowing the hematoma expansion, limiting the secondary injury and preventing medical complications. CONCLUSIONS: The 30-day mortality of SICH remains dismal (42%) despite modern ICUs. Recent prognostic studies have brought new insights about various SICH predictors, but even so there are still several unanswered questions. Treatment for this hemorrhagic stroke is primarily supportive, although recombinant factor VIIa may represent the first proven treatment for SICH.

[Prevalence of neurosonographic disturbances in chronic instability]. / Prevalencia de alteraciones neurosonológicas en la inestabilidad crónica.

INTRODUCTION: Dizziness is a common symptom at the outpatient clinic of family doctors. Its origin is usually multifactorial and its outcome is often benign. However, exists a tendency to relate the dizziness with a cerebrovascular disturbance. AIM. To determine if there are cerebrovascular disorders in patients with chronic dizziness using a non invasive technique. PATIENTS AND METHODS: A prospective study was conducted. It included 404 patients without limit of age. The patients were evaluated in a Neurology Outpatient Clinic, to select those patients with chronic instability. A neurosonographic exam was performed to all those selected patients. This exam included colour duplex of the cervical arteries and transcranial Doppler. RESULTS: Up to 54 % of the patients who were included in the study had a normal carotid study. For the rest of the patients, the thickness intima-media was the most prevalent finding. At the vertebrobasilar system the study of the vertebral arteries was completely normal in 81.7% followed by the presence of microangiopathy in 12.1%. The basilar system was also normal in a high figure (78%) followed by the microangiopathy (17.1%). CONCLUSIONS: The vascular disturbances in the vertebrobasilar system are an exceptional finding in patients with chronic instability.

Sindrome de Guillain-Barre / Guillain-Barre's syndrome

Objetivo. Hacer una revisión de este trastorno, poniendo énfasis en los cuidados intensivos del paciente con síndrome de Guillain-Barré (SCB) grave. Desarrollo. El SGB es una polineuropatía inflamatoria autoinmune, que puede originar cuadriparesia, fallo respiratorio, disfunción autonómica, así como otras complicaciones graves, que pueden influir notablemente en la evolución del enfermo. Por tal motivo, los pacientes con SGB grave requieren atención en unidades de cuidados intensivos (UCI), en donde también pueden surgir nuevas complicaciones además de las ya anteriormente mencionadas. El neurólogo que pretenda tratar integral y continuamente a estos enfermos deberá estar familiarizado con la terapia antimicrobiana, nutrición del enfermo crítico, equilibrio hidromineral, ciertos aspectos sobre ventilación mecánica, y las indicaciones y complicaciones de la plasmaféresis y de la infusión de inmunoglobulinas. Conclusiones. Con los cuidados intensivos disponibles actualmente, la evolución de estos enfermos suele ser excelente (recuperación en más de un 80 por ciento de los casos), aunque en algunos pacientes persiste cierto grado de paresia residual. Atendiendo a que el SGB es un proceso en gran medida autolimitado, se suele plantear que el cuidado esmerado y diario de estos enfermos y sus complicaciones en la UCI contribuye a la buena evolución de un paciente individual, tanto o más que la terapia inmunomoduladora

[Guillain Barre syndrome]. / Síndrome de Guillain-Barré

OBJECTIVE: To review about this disorder, with emphasis on the intensive care of severe Guillain Barr syndrome (GBS). DEVELOPMENT: GBS is an acute immune mediated inflammatory polyneuropathy that may lead to quadriparesis, ventilatory failure, and autonomic dysfunction but also to many general medical problems that have great bearing on outcome. Therefore severe GBS patients require admission into an intensive care unit (ICU), where in addition to the disorders mentioned before, other complications can arise. The neurologist who plans to deal comprehensively with these patients must be familiar with therapy for infections, nutrition, fluid management, and selected aspects of pulmonary medicine as well as the indications for and complications of plasma exchange and gammaglobulin infusion. CONCLUSIONS: With modern intensive care support, the outcome is excellent (>80% recovery), although in many cases a persistent residual paresis occurs. Because GBS is largely self limited, the skill daily cares of these patients in an ICU contributes as much, or more, to the overall outcome of an individual patient as do specific immune therapies.

Colocalization of vasopressin and oxytocin in hypothalamic magnocellular neurons in water-deprived rats.

The posterior lobe hormones vasopressin and oxytocin are expressed in mutually-exclusive sets of magnocellular hypothamalic neurons. However, under certain functional conditions a partial coexpression has been observed. In the present study we subjected adult rats to long-term osmotic stress by water deprivation for up to 3 days. After 3 days, a marked reduction of vasopressin immunostaining was observed in the paraventricular and supraoptic nuclei as compared with controls. Coexistence of oxytocin and vasopressin occurred in a portion of the magnocellular neurons. Many fibers of the hypothalamic-neurohypophyseal tract contained both peptides. Rehydration for 24 h after 3 days of thirsting resulted in a light recovery of vasopressin immunoreactivity with almost none magnocellular neurons containing both nonapeptides. Our findings indicate that magnocellular hypothalamo neurohypophysial neurons are capable of oxytocin and vasopressin coexpression upon extended osmotic stress.

[Antisense targeting in neurology]. / Antisense targeting en Neurología.

INTRODUCTION: Antisense targeting refers to the use of synthetic short lengths of single stranded DNA, or RNA with base sequences complementary to a specific gene or its mRNA. Commonly, synthetic oligonucleotides are designed to hybridize to specific mRNA and thus preventing its translation in a specific protein. DEVELOPMENT: The use of this technology as research tool is well known since two decades ago, but it has been in the last few years, when it has been proposed as a promising tool for the development of a new generation of drugs with high specificity, relative ease of production and low rate of toxicity. Antisense therapeutics is currently being evaluated in clinical trials for cancer, inflammation, and viral diseases. In the field of Neuropharmacology, it has become in a very valuable tool to block the expression of specific genes in vitro as well in the living brain. In this article, we review the contributions of this technology in the field of the Neurosciences, and also give an overview concerning the advances of the antisense strategy in the design of possible new treatments for certain neurological disorders. Other clinically relevant information regarding molecular biology, pharmacokinetics, mechanism of action, and side effects of antisense oligonucleotides has been collected and summarized. CONCLUSIONS: In the neuropharmacological area is the Neurooncology the most intensively researched; nevertheless, the lack of oligos that cross the blood-brain barrier in sufficient amount continues being one of the main difficulties for the successful application of this technique on the central nervous system.

[Intensive neurology. Past, present, and future]. / Neurología intensiva. Pasado, presente y futuro.

Although the neurological intensive care, seem have originated at the ends of 40s, during the epidemic of acute poliomyelitis that flogged Europe, it must be indicated that the growth and expansion of this subspecialty, has been a remarkable fact only in the course of the two last decades. Despite the fact that the neurological intensive care units (Neuro-ICU) are expensive; multiple have been the benefits derived from their creation; so much for patients, hospitals, as well for medical teaching. This is the current panorama of these units, mainly in developed countries, however, unfortunately this is not the situation in others, especially the underdeveloped ones. Many of the dilemmas that today confronts neurology in our countries are due to the nonexistence of these units. Undoubtedly, the neurocritical patients results more benefitted, when receives attention from the neurointensivists; thus the medical care that it receives becomes defragmented. The creation of the Neuro-ICU in our countries should not be made in a generalized way, but strategically, in addition, would be very convenient the incorporation of neurointensivists in the polyvalent intensive care units or intermediate care units. For the future, it will have to keep in mind the fact, that certain novel procedures that today emerge for the management of certain neurocritical conditions, will have to be assimilated by neurointensivists, since they will be the personnel disposed to implement them in any moment, and what is more important, it is the competent personnel prepared to treat any complication that emerge upon applying these.

[Apnea testing to establish death based on brain criteria]. / Prueba de apnea en la determinación de la muerte por criterios cerebrales.

INTRODUCTION: The apnea test provides one of the most important criteria for the diagnosis of death by brain criteria, nevertheless although the absence of spontaneous respiration is a crucial point in the diagnosis of the death, we must point out, that still, there are not standardized criterion to perform this test. DEVELOPMENT: The lack of uniformity at the moment of carrying out this test in our country is due to the use of time as an indirect estimate of the PCO2 levels instead of the actual measurement of the blood level of this gas. This paper reviews the recommendations about this procedure published in the medical literature. It also remarks the most interesting physiopathological aspects related to this test. CONCLUSIONS: At present, the literature does not provide evidence to favor one method over the other however, it seems generally accepted that a positive apnea test requires a level of PCO2 equal or greater than 60 mmHg. Optionally, it is possible to consider 20 mmHg above the starting arterial PCO2 level. It seems clear that this aspect is more important than the duration of the test. The fears about hypoxemic damage during the apnea test are not support by the information found in the literature. It seems that the respiratory like movements do not exclude the diagnosis of death by brain criteria.