Preoptic-periventricular tissue (AV3V): central cholinergic-induced hydromineral and cardiovascular responses, and salt intake.

The periventricular tissue of the anterior ventral portion of the third ventricle (AV3V) is an important area for the control of hydromineral balance and of cardiovascular function. The present work discusses the importance of the integrity of the AV3V for multiple responses to central cholinergic activation (water intake, hypertension, natriuresis, salivation) and for the control of salt intake.

Circadian time-dependent effects of fencamfamine on inhibition of dopamine uptake and release in rat striatal slices

Fencamfamine (FCF) is a central stimulant that facilitates central dopaminergic transmission through inhibition of dopamine uptake and enhanced release of the transmitter. We evaluated the changes in the inhibition of uptake and the release of striatal [ 3H]-dopamine at 9:00 and 21:00 h, times corresponding to maximal and minimal behavioral responses to FCF, respectively. Adult male Wistar rats (200-250 g) maintained on a 12-h light/12-h dark cycle (lights on at 7:00 h) were used. In the behavioral experiments the rats (N = 8 for each group) received FCF (3.5 mg/kg, ip) or saline at 9:00 or 21:00 h. Fifteen minutes after treatment the duration of activity (sniffing, rearing and locomotion) was recorded for 120 min. The basal motor activity was higher (28.6 ± 4.2 vs 8.4 ± 3.5 s) after saline administration at 21:00 h than at 9:00 h. FCF at a single dose significantly enhanced the basal motor activity (38.3 ± 4.5 vs 8.4 ± 3.5 s) and increased the duration of exploratory activity (38.3 ± 4.5 vs 32.1 ± 4.6 s) during the light, but not the dark phase. Two other groups of rats (N = 6 for each group) were decapitated at 9:00 and 21:00 h and striata were dissected for dopamine uptake and relase assays. The inhibition of uptake and release of [ 3H]-dopamine were higher at 9:00 than at 21:00 h, suggesting that uptake inhibition and the release properties of FCF undergo daily variation. These data suggest that the circadian time-dependent effects of FCF might be related to a higher susceptibility of dopamine presynaptic terminals to the action of FCF during the light phase which corresponds to the rats' resting period.

α-Adrenoceptor-mediated prejunctional effects of chloroethylclonidine in the canine saphenous vein

The present study was undertaken to look for the effect of chloroethylclonidine (CEC) on prejunctional alpha-2 autoreceptors of the canine saphenous vein. The effect was tested on tritium overflow evoked by electrical stimulation from tissues preloaded with 0.2 μM 3H- norepinephrine. Yohimbine (3-300 nM) and CEC (1-125 μM) increased and UK- 14,304 reduced the overflow of tritium evoked by 300 pulses (1 Hz). The maximal increase of tritium overflow caused by yohimbine was much higher than that caused by CEC: 3.82 and 1.74 times, respectively. CEC (5 μM) abolished both the inhibition caused by UK-14,304 and the enhancement of tritium overflow caused by yohimbine. However, when CEC was added after yohimbine, it reduced the electrically evoked overflow of tritium, the maximal effect being a reduction of tritium overflow by 35%. Prazosin (1-100 nM) did not change either the inhibitory effect of UK-14,304 or the facilitatory effect of CEC. These results suggest that CEC acts on two different subtypes of prejunctional alpha-2 autoreceptors; on one of them it acts as an antagonist and increases the electrically evoked overflow of tritium (and inhibits both the effect of UK-14,304 and yohimbine); on the other it acts as an agonist and reduces the electrically evoked overflow of tritium. Alternatively, one can admit that CEC is able to inhibit alpha-2 autoreceptors, which causes an increase of the transmitter release, and to activate a nonadrenergic inhibitory receptor thus causing a reduction of the transmitter release.

Tempo de latencia do rocuronio e da succinilcolina e condicoes de intubacao traqueal

Background and Objectives - Pulmonary aspiration of gastric content during induction of anesthesia for emergency surgical procedures is a serious complication; fast endotracheal intubation under these circumstances is of vital importance to secure the airways. Despite its numerous side effects, succinylcholine is used for this purpose. Rocuronium is the most recently introduced aminoesteroid neuromuscular blocking drug with short onset. The objective of this study was to compare the onset time and intubating conditions of rocuronium and succinylcholine. Methods - After informed consent, forty-five patients were randomly allocated into three groups of 15: Group I (GI) = succinylcholine 1 mg.kg-1; Group II (GII) = rocuronium 0.6 mg.kg-1; Group III (GIII) = rocuronium 0.9 mg.kg-1. Every patient was premedicated with midazolam 15 mg per os and induction of anesthesia was made with fentanyl 10 μg.kg-1 and etomidate 0.3 mg.kg-1. The neuromuscular block was monitored with the TOP-Guard neuromuscular transmission monitor. The TOP-Guard neuromuscular monitor uses an accelerometer to measure the response to nerve stimulation. The stimulating electrodes were placed close to the course of the ulnar nerve at the wrist. The onset time was considered as the time between the end of neuromuscular drug injection and the twitch height (T1) decrease to 10%. Heart rate and arterial blood pressure were registered at 6 moments before and after induction of anesthesia. Results - The onset time results were: Group I, 71 s; Group II, 120 s and Group III, 70 s or GI = GIII < GII (F = 8.862; p < 0.01). There were 43 patients exhibiting excellent intubating conditions and 2 with good intubating conditions. Heart rate and arterial blood pressure showed alterations due to induction of anesthesia and intubation. Conclusions - Rocuronium 0.9 mg.kg-1 can be used in rapid sequence induction because it has a short onset time which is similar to that of succnylcholine. It is likely that rocuronium would be a good indication in patients with high intracranial pressure, burns and neuromuscular diseases.

Reconsiderations about the clinical importance of the sympathetic skin response

Over the last few years, neurologists have been showing increasing interest in the study of the sympathetic skin response (SSR). In the present report we describe a simple method that permitted us to determine a wide variation of SSR in response to different stimuli such as respiration, deglutition, blinking, skeletal movements, biting, auditory or light stimuli, vocalization, and sphincter contraction. These results raise doubts about the role of SSR as a complementary diagnostic method.

Use of fibrin glue derived from snake venom in testicular biopsy of rams

Sequelae due to testicular biopsy such as hemorrhage, adhesion and fibrosis may be limiting factors to the use of this surgical procedure. Fibrin glue (FG) derived from snake venom was used to minimize these sequelae, as well as to evaluate its healing property in tunica vaginalis and scrotal skin of rams. Applicability of fibrin glue derived from snake venom was tested in different tissues of other animals such as in sciatic nerve and colon of rats and skin of rabbits. In the present study, 30 healthy adult rams were used. They were divided into 3 groups of 10 animals each as follows: G1: fibrin glue group (application of fibrin glue on puncture sites and skin incisions after bilateral testicular biopsy with a Tru-Cut needle); G2: swab/nylon group (hemostasis by compression with a swab on puncture sites and skin suturing with nylon after biopsy) and G3: control group (the animals were not subjected either to biopsy or to surgery). On the 20th day after biopsy, the presence of adhesion strands between the sites of skin incision and testicle was evaluated by palpation Adhesion strands were found in three testicles (15%) in G1 and in two testicles (10%) in G2. One hundred days after biopsy, orchiectomy was carried out and the material collected was assessed for subcutaneous (SC) and/or tunica vaginalis adhesions. G3 did not present any abnormality. Groups G1 and G2 presented four testicles each (20%) with adhesion between the tunics at biopsy site. On the other hand, subcutaneous adhesions were found once (5%) in G1 and three times (15%) in G2. Fibrin glue showed to be of easy application, required short postoperative monitoring, presented fast and good-quality healing property and tended to reduce formation of subcutaneous adhesion.

Peridural com ropivacaina a 1%: Experiencia com volume proporcional a estatura

Background and Objectives - Ropivacaine - a local amino amide anesthetic agent - is a plain S enantiomer which makes it a potent and low toxicity drug. The aim of our study was to evaluate 1% ropivacaine for epidural block in lower doses than those described in the literature. Methods - Thirty-eight patients, physical status ASA I and II, aged 15 to 70 years, weighing 50 to 100 kg were selected. Premedication consisted of 15 mg oral midazolam given 60 min before anesthesia induction. In the OR, after standard monitoring a catheter was inserted intravenously to administer 10 ml.kg-1 Ringers lactate solution. Epidural puncture was performed with the patient in the sitting position and 1% ropivacaine was administered in a volume corresponding to 10% of patient's height in centimeters. With the patient in the supine position, motor blockade intensity, temperature sensitivity and sensory block extension at 1, 3, 5, 7, 10, 15, 20, 30 minutes after drug injection were evaluated. Blood pressure, heart rate and adverse side effects during the course of anesthesia and in the post-anesthetic period were also observed. In the recovery room patients were followed-up until motor blockade intensity temperature sensitivity and sensory block had returned to level L2. Results - Mean values were 41.4 years of age, 68.8 kg of body weight and 165 cm height. Upper thermal blockade level was T4 and upper sensory block level was T6. Most patients showed motor block level 1 (Bromage scale) after 30 minutes of observation. Motor block mean duration was 254 minutes and temperature sensitivity 426 minutes. Only three patients had complications: two cases of hypotension and one of bradycardia. Conclusions - In the volumes used in this study, ropivacaine produced adequate analgesia and a less intense lower limb motor block which, however, was sufficient to allow for surgical procedures with low incidence of side-effects.

Comparative structural analysis of neuromuscular junctions in mice at different ages

The authors studied the histochemical and ultrastructural modifications that occur in the neuromuscular junctions (NMJ) of fibularis longus muscles of mice with an age range of 3 to 21 months. Twenty-four male and female animals were killed at 3, 5, 14 and 21 months of age: 7 of them at 3 months, 4 of them at 5 month, 9 at 14 months and 4 at 21 months. The fibularis longus muscles were processed and their NMJ examined with the transmission electron microscope. The most relevant changes were associated with the degeneration and retraction of terminal axons, i.e., axons poor in synaptic vesicles with degenerated mitochondria, and exhibiting multivesicular bodies and vacuoles; exposed and widened junctional folds and cytoplasmic processes of Schwann cells located in the synaptic gutter. The presence of lysosomes or lipofuchsin in the juxtajunctional sarcoplasm was also noted. These observations suggest that the phenomena of retraction and budding occur in the NMJ with advancing age, with a predominance of events associated with degeneration, leading to profound changes in NMJ shape.

Síndrome de Garcin relacionada a linfoma não-Hodgkin

The complete unilateral cranial nerve paralysis syndrome, or Garcin 's Syndrome, is a rare clinical condition. The purpose of this paper is to describe a case associated with non-Hodgkin s lymphoma. A 41-year-old male patient developed a progressive cranial nerve disorder. On the right hand side, there was impairment of all cranial nerves. We report the clinical and laboratorial findings. Lymph node exeresis revealed a Diffuse Non-Hodgkin s Lymphoma, with diffuse hone marrow infiltration. Cerebrospinal fluid showed pleocytosis, with 100% of immunoblasts. The CT scan showed no tumoral masses on the brain stem. This is the first clinical description of a complete Garcin 's Syndrome caused by diffuse lymphomatous infiltration of the cranial nerves.

Optic neuropathy in sheep associated with overdosage of closantel

This report describes clinical and pathological findings in 2 flocks in Brazil where blindness and deaths in sheep occurred after closantel overdosage. Depression, weakness, and blindness affected 37 animals and 17 died in 2 flocks of 190 animals. Two animals submitted for ophthalmic examination showed no inflammation in the anterior segment of both eyes; posterior segment evaluation by indirect ophthalmoscopy suggested retinal degeneration. One postmortem evaluation local spongy vacuolization was in several regions of the brain and the optical nerves had severe axonal degeneration.

Tempo de latencia e duracao do efeito do brometo de rocuronio no paciente submetido ao transplante renal

Background and Objectives - Successful cadaver kidney transplantation relies on a fast procedure. Patients with chronic renal failure may present with a delayed gastric emptying making it critical a fast tracheal intubation and airway maintenance. Rocuronium a recently introduced nondepolarizing neuromuscular blocker with a fast onset. The aim of this study was to evaluate onset time and duration of rocuronium effects in patients undergoing renal transplantation. Methods - Sixty patients were allocated into two groups of 30: Group R (GR) = patients undergoing renal transplantation and Group N (GN) = patients with normal renal function. All patients were premedicated with oral midazolam (15 mg) and anesthesia was induced with 30 μg.kg-1 alfentanil, 0.3 mg.kg-1 etomidate and 0.6 mg.kg-1 rocuronium injected through a central venous catheter. neuromuscular block was monitored by acceleromyography in the ulnar nerve pathway. The following parameters were evaluated: time between administration of rocuronium and first twitch reduction to 5% after supra-maximal stimulation (T1) (onset time = OT); time for first twitch to return to 25% (clinical duration = R25); time elapsed between 25% and 75% recovery of first twitch (relaxation recovery time = R25-75). Heart rate (HR) and mean blood pressure (MBP) were recorded in 6 moments. Results - Median OT was 31 sec. in GR and 47 sec. in GN. Median R25 was 51.5 min in GR and 33.5 min in GN. Median R25-75 was 28 min in GR and 20 min in GN. MBP and HR were higher in GR. Tracheal intubation conditions were excellent for most patients in both groups. Conclusions - These results open the possibility of 0.6 mg.kg-1 rocuronium being injected through a central venous catheter when a faster onset is needed. Due to wide differences in individual responses, monitoring of neuromuscular block is recommended.

Silent period in carpal tunnel syndrome

The silent period is a misunderstood electrophysiological phenomenon leading to several different hypotheses explaining its electrogenesis. It has been studied by different authors and different methodologies giving a wide variability of results, therefore an exact pattern of its normal values does not exist. This work was undertaken to define the normal morphology and duration of the silent period obtained by supramaximal stimulus of the median nerve, during maximum isometric effort of the abductor pollicis brevis muscle against resistance, using 20 adult volunteers without neurological alterations. The normal median duration was 104.6 milliseconds. The same methodology was applied to 20 hands from 20 patients with carpal tunnel syndrome. The silent period showed many types of morphological alterations, but the major alteration observed was a tendency to temporal elongation. No correlation between the severity of the carpal tunnel syndrome and the silent period alterations were observed.

The anatomical connections of the macaque monkey orbitofrontal cortex. A review

The orbitofrontal cortex (OfC) is a heterogeneous prefrontal sector selectively connected with a wide constellation of other prefrontal, limbic, sensory and premotor areas. Among the limbic cortical connections, the ones with the bippocampus and parabippocampal cortex are particularly salient. Sensory cortices connected with the OfC include areas involved in olfactory, gustatory, somatosensory, auditory and visual processing. Subcortical structures with prominent OfC connections include the amygdala, numerous thalamic nuclei, the striatum, hypothalamus, periaqueductal gray matter, and biochemically specific cell groups in the basal forebrain and brainstem. Architectonic and connectional evidence supports parcellation of the OfC. The rostrally placed isocortical sector is mainly connected with isocortical areas, including sensory areas of the auditory, somatic and visual modalities, whereas the caudal non-isocortical sector is principally connected with non-isocortical areas, and, in the sensory domain, with olfactory and gustatory areas. The connections of the isocortical and non- isocortical orbital sectors with the amygdala, thalamus, striatum, hypotbalamus and periaqueductal gray matter are also specific. The medial sector of the OfC is selectively connected with the bippocampus, posterior parabippocampal cortex, posterior cingulate and retrosplenial areas, and area prostriata, while the lateral orbitofrontal sector is the most heavily connected with sensory areas of the gustatory, somatic and visual modalities, with premotor regions, and with the amygdala.

Morphological aspects of rabbit masseter muscle after cervical sympathectomy

The objective of this paper was to study the effect of sympathetic innervation on morphological and histochemical aspects of skeletal muscle tissue. Rabbit masseter muscle was studied using histochemical and immunohistochemical methods for periods of up to 18 months post-sympathectomy. The morphological and enzymatic characteristics of control masseter muscles were similar on both the left and right sides. The main features were muscle fibres with a mosaic pattern and a predominance of type IIa fibres, followed by type I. Type IIb fibres showed very low frequency. Sympathectomized animals showed varying degrees of metabolic and morphological alterations, especially 18 months after sympathectomy. The first five groups showed a higher frequency of type I fibres, whilst the oldest group showed a higher frequency of type lib fibres. In the oldest group, a significant variation in fibre diameter was observed. Many fibres showed small diameter, atrophy, hypertrophy, splitting, and necrosis. Areas with fibrosis were observed. Thus cervical sympathectomy induced morphological alterations in the masseter muscles. These alterations were, in part, similar to both denervation and myopathy. These findings indicate that sympathetic innervation contributes to the maintenance of the morphological and metabolic features of masseter muscle fibres.

Seqüência de moebius: Manifestações clínicas e avaliação auditiva

Introduction: Children with Moebius syndrome may present paralysis of cranial nerves III, IV, V, VI, VII, VIII, IX, X and XII, compromising motor and sensorial functions. Hands and feet defects (syndactyly, equinovarus and arthrogryposis) are frequently associated. These manifestations can be attributed to the use of misoprostol during pregnancy to induce abortion. Study design: Clinical prospective. Aim: To evaluate the main clinical manifestations, hearing acuity and possible etiologic factors in children with Moebius syndrome. Material and method: The children were submitted to clinical, otolaryngological and hearing acuity assessment. Hearing acuity was evaluated through behavioral tests, pure tone audiometry, tympanometry and auditory brainstem response (ABR). We investigated possible etiologic factors. Results: Three boys and two girls were evaluated. The main manifestations were: facial paralysis, paralysis of masseter muscle, defects in dental occlusion, retraction of tympanic membrane, equinovarus, oblique palpebral fissure and tongue atrophy. Conductive hearing loss was detected in three children and sensorineural hearing loss in one child. The use of misoprostol during pregnancy was reported by four mothers. Conclusions: The children with Moebius syndrome evaluated in the present study manifested palsies of various cranial nerves, especially V, VII and XII nerves, responsible for motor and sensorial alterations. Inadequate eustachian tube function associated to conductive hearing loss was frequent. The use of misoprostol during pregnancy was reported by the mothers and it was considered a possible etiologic factor.