The present study examined GABA immunoreactivity within the retinopetal nucleus isthmo-opticus (NIO) of the pigeon centrifugal visual system (CVS) using light- (immunohistofluorescence, peroxidase anti-peroxidase: PAP) and electron- (postembedding GABA immunogold) microscopic techniques. In some double-labeling experiments, the retrograde transport of the fluorescent dye rhodamine beta-isothiocyanate (RITC) after its intraocular injection was combined with GABA immunohistofluorescence. GABA-immunoreactive (-ir) somata were demonstrated within the neuropilar zone of the NIO adjacent to the centrifugal cell laminae whereas the centrifugal neurons were always immunonegative. A quantitative ultrastructural analysis was performed which distinguished five categories of axon terminal profiles (P1-5) on the basis of various cytological criteria: type of synaptic contact (symmetrical or asymmetrical); shape, size, and density of synaptic vesicles as well as the immunolabeling (positive or negative), size of profile and appearance of hyaloplasm. Numerous GABA-ir afferents to centrifugal neurons via axon terminal types P2a, P2c, and P3 were observed which comprised 47.1% of the total input. Moreover, the data suggest that some of the P2a terminals, which make up 26.4% of the input, stem from the intrinsic GABA-ir interneurons, whereas the latter receive P1, P3, but also P2 terminal input, indicating that interneurons may contact other interneurons via type P2a axon terminals. The results also suggest that the GABA-ir P3 or the immunonegative P1b and P5 axon terminals are of extrinsic origin arising from cells in the optic tectum whereas the P2c and P4 axon terminals are associated with extra-tectal input to the NIO. The GABAergic innervation of centrifugal neurons within the NIO may be the basis for the demonstrated facilitatory effect of the centrifugal output upon ganglion cell responses. This is relevant to hypotheses regarding CVS involvement in attentional mechanisms through selective enhancement of retinal sensitivity depending on the location of meaningful or novel stimuli.

Animals↗

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mtDNA ribosomal gene phylogeny of sea hares in the genus Aplysia (Gastropoda, Opisthobranchia, Anaspidea): implications for comparative neurobiology.

Sea hares within the genus Aplysia are important neurobiological model organisms; as more studies based on different Aplysia species are appearing in the literature, a phylogenetic framework has become essential. We present a phylogenetic hypothesis for this genus, based on portions of two mitochondrial genes (12S and 16S). In addition, we reconstruct the evolution of several behavioral characters of interest to neurobiologists to illustrate the potential benefits of a phylogeny for the genus Aplysia. These benefits include determination of ancestral traits, direction and timing of evolution of characters, prediction of the distribution of traits, and identification of cases of independent acquisition of traits within lineages. This last benefit may prove especially useful in understanding the linkage between behaviors and their underlying neurological bases.

Animals↗

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[Recurrent angioedema and hypereosinophilia].

INTRODUCTION: Among the various causes of eosinophilia are the syndrome first described by Gleich in 1984. This syndrome is characterized by angioedema of the face, neck, extremities and trunk, weight gain, hypereosinophilia (60-70%), fever, and increased serum IgM levels without involvement of the vital organs. CASE REPORT: A 17-year-old non-allergic woman was referred to our hospital for further investigation of recurrent angioedema, initially of the hands and feet and subsequently of the face, with onset 3 years previously. The attacks had become more frequent and severe and had occurred monthly in the previous year. The patient also showed general malaise, without fever. Complementary investigations revealed eosinophils 40.8%, total count 3,300/mm3, and serum IgM levels 343 mg/dl (normal range: 53-300 mg/dl). Possible causes of hypereosinophilia and eosinophilic infiltration of vital organs were ruled out. The patient was treated with oral corticosteroids which produced clinical remission and reduction of eosinophil count (1.7%, total 200/mm3). DISCUSSION: Gleich syndrome is uncommon and has well-defined clinical features and a benign course. We describe a patient who presented the clinical characteristics of this syndrome with good response to steroids and without involvement of vital organs. CONCLUSIONS: Our patient presented clinical features compatible with a diagnosis of Gleich syndrome. Other entities associated with hypereosinophilia were ruled out.

Adolescent↗

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Clinical vasospasm after subarachnoid hemorrhage: response to hypervolemic hemodilution and arterial hypertension.

Delayed neurologic deterioration from vasospasm remains the greatest cause of morbidity and mortality following subarachnoid hemorrhage. The authors assess the incidence and clinical course of symptomatic vasospasm following subarachnoid hemorrhage using a uniform management protocol over a 24-month period. One hundred eighteen consecutive patients were admitted to the neurovascular surgery service within 2 weeks of subarachnoid hemorrhage not attributed to trauma, tumor, or vascular malformation (113 patients had aneurysms). Early surgery was performed whenever possible, and hypertensive hypervolemic hemodilution therapy was instituted at the first sign of clinical vasospasm. Forty-two patients (35.6%) developed characteristic signs and symptoms of clinical vasospasm with angiographic verification of spasm in 39 cases. All patients with clinical vasospasm received hypervolemic hemodilution therapy aiming for a hematocrit of 33-38%, a central venous pressure of 10-12 mm Hg (or a pulmonary wedge pressure of 15-18 mm Hg), and a systolic arterial pressure of 160-200 mm Hg (120-150 mm Hg for unclipped aneurysms) for the duration of clinical vasospasm. Over the course of treatment, 60% of patients with clinical vasospasm had sustained improvement by at least 1 neurologic grade, 24% maintained a stable neurologic status, and 16% continued to worsen. At the end of hypervolemic hemodilution therapy, 47.6% had become neurologically normal, 33.3% had a minor neurologic deficit, and 19% had a major neurologic deficit or were dead. There were 3 instances of cardiopulmonary deterioration (7%), all of which were in patients without Swan-Ganz catheters, and all resolved with appropriate diuresis. One patient rebled and died while on hypervolemic hemodilution therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

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Novel antiadhesion barrier does not prevent anastomotic healing in a rabbit model.

Intraperitoneal adhesions following surgical procedures cause considerable morbidity. Hyaluronic acid/carboxymethylcellulose (HA/CMC) films have been shown to be effective agents in decreasing adhesion formation. However, when there is an inadvertent leak of bowel contents into the peritoneum due to incomplete anastomosis, adhesion formation about a defect in order to prevent further leakage and to promote healing of the wound is important for the prevention of morbidity and mortality. The purpose of this study was to determine if an antiadhesion film (HA/CMC) impairs these potentially beneficial adhesions to bowel anastomoses, thus predisposing them to enteric leaks with subsequent peritonitis. Sixty-four rabbits were divided in two groups, each undergoing a complete or partial (90% anastomosis to simulate anastomotic leak) large bowel anastomosis. Half of each of the above groups were treated by wrapping a HA/CMC film over the anastomosis and the other half were untreated controls. These two subgroups were then further divided equally and sacrificed at either 7 or 14 days for evaluation of anastomosis integrity and strength. The average anastomotic bursting pressures did not change significantly between those groups treated with HA/CMC when compared to untreated controls at 7 or 14 days or in the complete or partial anastomosis group (Student's t test). Adhesion formation to the anastomosis was not impaired in either group independent of HA/CMC film application. This study suggests that while HA/CMC film has been shown to decrease adhesions in other models, healing of a rabbit colonic anastomosis even in the presence of an anastomotic defect takes place, further suggesting that the stimulus for adhesion formation can overcome the antiadhesion properties of HA/CMC.(ABSTRACT TRUNCATED AT 250 WORDS)

Anastomosis, Surgical↗

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[Menkes disease: experience in copper salts therapy].

INTRODUCTION: Menkes disease is an X linked genetic disorder of copper intracellular transport. The clinical effects are explainable by impaired activity of various copper-dependent enzymes. The classic form of the disease is characterized by: low temperature, impairment of growth, characteristic hair abnormalities (thin, breakable and grey-haired) and seizures with severe developmental retardation from birth. Treatment with various forms of copper salts has been used, but none of them effective. CLINICAL CASE: We report a patient diagnosed of Menkes disease at 12 months of age. Copper treatment was commenced at 14 months with 100 micrograms/kg daily intravenous infusion of copper sulphate. On the basis of copper and ceruloplasmin plasma levels, doses of treatment were controlled until a maintained dose of 1,000 micrograms intramuscular of copper sulphate every 17 days, until the age of 6 years. The effects of the treatment were marked by the normalization of the biochemical parameters, the growth development and the hair characteristics. However, no significant effect was shown on the seizures or the neurologic impairment. The patient died at the age of 7 years old. CONCLUSION: Parenteral therapy for Menkes disease with various inorganic copper salts has been shown to get longer clinical course, but no successful effect on the devastating neurodegenerative progression of the disease.

Child↗

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Use of erythropoietin in emergencies: massive intoxication by chloramines.

Recombinant human Erythropoietin (rHuEPO) is normally used to correct anaemia in patients with End Stage Renal Disease (ESRD), that are in Regular Dialysis Treatment (RDT). This anaemia is usually due to the existence of two factors: A decrease in the erythropoiesis of the bone marrow and an increase in peripheral haemolysis and, consequently, a decrease in the life span of the red cells.

Anemia↗

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Formidable challenges to teaching advanced laparoscopic skills.

Despite the acceptance of laparoscopy for performing routine operations, a need still exists for experienced surgeons and surgical residents to maintain and refine essential surgical skills. Unless used on a frequent basis, laparoscopic skills are not easily maintained. In addition, when new laparoscopic instruments are introduced, surgeons need a way to practice using them that does not involve immediate patient contact. Novice surgeons need the most training of all and ideally would be best served using a standardized teaching curriculum that would cover as many of the basic laparoscopic parameters as possible. This article discusses how best to set up a laparoscopic simulation training program that covers as much ground as necessary, while respecting the restraints of time limitations and monetary concerns.

Clinical Competence↗

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[Thymectomy in juvenile myasthenia gravis].

INTRODUCTION: Juvenile myasthenia gravis (JMG) is an infrequent autoimmune disease, the symptoms and therapeutic handling of which do not differ from those of the adult forms. Chronic treatment with corticoids very often causes side effects in childhood, which is why patients are being submitted to thymectomies at younger ages with better results. AIMS. To analyse the clinical and evolutionary profile of JMG treated by thymectomy in our centre. PATIENTS AND METHODS: We report the case of four girls aged between 5 and 13 who were diagnosed as suffering from generalised myasthenia gravis (MG) with bulbar affectation. One of them started with a myasthenic crisis. The four of them were submitted to Tensilon s test, an electrophysiological study, determination of AChR, thoracic CT, and study of autoimmunity and thyroid functioning. After surgery the thymus was analysed histologically. RESULTS: They all gave positive in Tensilon s test and were seropositive for AChR. They were treated with anticholinesterases, up to the maximum tolerated dose, and corticoids, without complete remission being accomplished and so they were submitted to a thymectomy in the first year of evolution. In three cases surgical approach was transsternal and in the other by means of a videothoracoscope. All the thymuses showed lymphoid hyperplasia. After a variable follow up the girls are at present asymptomatic, although none of them has been able to completely give up the pharmacological treatment. CONCLUSIONS: Thymectomy is one of the mainstays of treatment for JMG. The ever more frequent use of videothoracoscopic techniques achieves results that are similar to those obtained by conventional surgery but with fewer post operative and aesthetic problems

Adolescent↗

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Intestinal pathway of internalisation of lactic acid bacteria and gut mucosal immunostimulation.

The induction of the gut mucosal immune response is dependent on the antigen interacting with the M cells of Peyer's patches and with the immune cells associated with this lymphoid organ. In previous studies we showed that the mucosal immunostimulation by LAB varied depending upon the strain being studied. Some of them increased the inflammatory immune response and others enhanced the level of secretory antibody (S-IgA). Our aim was to determine the pathway of the internalisation of LAB strains in the intestine, to provide a basis for understing the different behaviour exhibited by them. The presence of LAB on Peyer's patches or in the immune cells associated with the villi of small intestine was determined using fluorescein-labelled bacteria and by transmission electron microscopy. Mice were dosed orally by intubation, with 101 cells of labelled single strains of Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus. For electron microscopy studies unlabelled bacteria were used. Histological preparations of the small and large intestine were performed 1 hour after administration of the bacteria. Fluorescent bacteria of L. casei and S. thermophilus were found only in Peyer's patches while L. delbrueckii ssp. bulgaricus and L. acidophilus were observed in Peyer's patches and in the small intestine. L. acidophilus was also found in the large intestine. We confirmed these findings by electron microscopy. We determined that for L. casei the pathway of internalisation was via the M and FAE cells of Peyer's patches, while for S. thermophilus, L. acidophilus and L. delbrueckii ssp. bulgaricus the interaction with the immune cells of Peyer's patches was through the follicle associated epithelium (FAE). L. delbrueckii ssp. bulgaricus and L. acidophilus also interacted with the epithelial cells of the small intestine and L. acidophilus with epithelial cells of the large intestine. These results suggest that the different effects of LAB on the mucosal immunostimulation, are related to the different pathways of gut internalisation used to take contact with the immune cells associated with the lamina propria intestinal.

Journal Article↗