Effects of pars intercerebralis removal on circatidal rhythm in the mangrove cricket, Apteronemobius asahinai.

The circatidal rhythm is an endogenous rhythm corresponding to the tidal cycles, and its neural mechanism remains unknown. The mangrove cricket, Apteronemobius asahinai, possesses both circatidal and circadian clocks, and simultaneously exhibits circatidal and circadian rhythms in its locomotor activity. In a previous study, we showed that surgical removal of the optic lobes, the principal circadian clock locus in crickets, disrupted their circadian rhythm, but not their circatidal rhythm. In this study, we focused on the pars intercerebralis (PI) because surgical removal of the PI disrupts the circadian rhythm and causes arrhythmic activity in some cricket species. After surgical removal of the PI, the proportion of crickets displaying circatidal rhythm decreased, and more than half of the crickets exhibited arrhythmic activity. Surgical removal of the regions around the PI also caused a similar effect on locomotor activity. Our results indicate that the PI and/or its surrounding regions are important not only for circadian but also for circatidal rhythm. This suggests the presence of a neural or hormonal pathway in the PI and/or its surrounding regions that is common to the circatidal and circadian rhythms.

Effects of pinealectomy on the neuroendocrine reproductive system and locomotor activity in male European sea bass, Dicentrarchus labrax.

The seasonally changing photoperiod controls the timing of reproduction in most fish species, however, the transduction of this photoperiodic information to the reproductive axis is still unclear. This study explored the potential role of two candidate neuropeptide systems, gonadotropin-inhibitory hormone (Gnih) and kisspeptin, as mediators between the pineal organ (a principle transducer of photoperiodic information) and reproductive axis in male European sea bass, Dicentrarchus labrax. Two seven-day experiments of pinealectomy (Px) were performed, in March (end of reproductive season) and August (resting season). Effects of Px and season on the brain expression of gnih (sbgnih) and its receptor (sbgnihr), kisspeptins (kiss1, kiss2) and their receptors (kissr2, kissr3) and gonadotropin-releasing hormone (gnrh1, gnrh2, gnrh3) and the main brain receptor (gnrhr-II-2b) genes, plasma melatonin levels and locomotor activity rhythms were examined. Results showed that Px reduced night-time plasma melatonin levels. Gene expression analyses demonstrated a sensitivity of the Gnih system to Px in March, with a reduction in sbgnih in the mid-hindbrain, a region with bilateral connections to the pineal organ. In August, kiss2 levels increased in Px animals but not in controls. Significant differences in expression were observed for diencephalic sbgnih, sbgnihr, kissr3 and tegmental gnrh2 between seasons. Recordings of locomotor activity following surgery revealed a change from light-synchronised to free-running rhythmic behavior. Altogether, the Gnih and Kiss2 sensitivity to Px and seasonal differences observed for Gnih and its receptor, Gnrh2, and the receptor for Kiss2 (Kissr3), suggested they could be mediators involved in the relay between environment and seasonal reproduction.

Role of neurosecretory cells in the photoperiodic induction of pupal diapause of the tobacco hornworm Manduca sexta.

In the tobacco hornworm, Manduca sexta, pupal diapause can be induced by exposure of fifth-instar larvae to a short-day photoperiod. We studied the effect of surgical ablation of tissues containing the neurosecretory cells of the brain of fifth-instar larvae on the photoperiodic induction of pupal diapause. At the end of the experiments, we immunostained the neurosecretory cells to determine the success of the ablations. Under long-day conditions (LD 16:8 at 22 degrees C), all intact larvae, most of the sham-operated larvae, and control-operated larvae developed into nondiapausing pupae. Under short-day conditions (LD 10:14 at 22 degrees C), most intact, sham-operated, and control-operated larvae developed into diapausing pupae. Removal of type-II cells did not interfere with the photoperiodic response. Under long-day conditions, elimination of type-Ia(1) cells did not affect the incidence of nondiapausing pupae. When type-Ia(1) cells were removed under short-day conditions, however, the incidence of nondiapausing pupae was higher (51%, n = 41) than that of the intact (16%, n = 75), sham-operated (24%, n = 88), control-operated larvae (5%, n = 40), and larvae with type-II cells removed (11%, n = 27). Thus, removal of type-Ia(1) cells can impede induction of diapause. These results indicate that the type-Ia(1) neurosecretory cells have an important role in the induction of pupal diapause.

Respuesta endócrino-metabólica neonatal a la cirugía / Neonatal endocrine and metabolic response to surgery

Con el propósito de describir la respuesta endócrino-metabólica a la cirugía (REMC) en el neonato y de enfatizar la importancia de su conocimiento para hacer racional el tratamiento y cuidados perioperatorios en este grupo de pacientes, se revisan las evidencias clínicas y experimentales de esta respuesta en este grupo de edad publicadas en los últimos diez años. Se describen los reflejos neuroendócrinos que inician la REMC en el neonato y se definen las características fundamentalmente del ambiente endócrino-metabólico neonatal postoperatorio. Además, se hacen consideraciones sobre su relevancia para determinar los cuidados perioperatorios del recién nacido. Se concluye que el neonato es capaz de establecer una REMC cualitativa y cuantitativamente diferente a la de otros grupos de edad, y que del conocimiento y comprensión de esta respuesta depende la calidad del tratamiento ofrecido al recién nacido quirúrgico

Serum neuron-specific enolase in diagnosis and follow-up of gastrointestinal neuroendocrine tumors.

Neuron-specific enolase (NSE), the glycolytic isoenzyme of the enolase gamma-gamma dimer, is a specific marker for the diffuse neuroendocrine system and derivative tumors (NET). Serum levels of NSE were measured in 39 patients with NET of the gastrointestinal tract (including 3 gastric and 13 intestinal carcinoid tumors, 6 gastrinomas, 3 insulinomas, 1 glucagonoma, 2 mixed islet cell tumors, 11 neuroendocrine pancreatic carcinomas), in 15 healthy subjects and in 15 nonendocrine gastric, pancreatic, and intestinal tumors. Thirty-six of the 39 patients had elevated circulating levels of NSE, 2 insulinomas and 1 gastrinoma had values below 12 ng/ml like healthy subjects and nonendocrine tumors. No significant difference of serum NSE was found between 23 'functioning' and 16 'nonfunctioning' NET. Fourteen of the NET were malignant, and NSE circulating values were significantly higher than those of nonmalignant forms. After curative surgery serum NSE decreased significantly. NSE can be considered a reliable marker in the differential diagnosis between endocrine and nonendocrine neoplasms, in the clinical detection of silent endocrine tumors and in the follow-up of NET.

[Neuroendocrine carcinoma of the esophagus]. / Carcinome neuro-endocrine de l'oesophage.

Small cell neuroendocrine carcinomas are frequent in the bronchial tree, but are very are in the gastrointestinal tract. A 51-year-old woman underwent total esophagectomy for an ulcerated tumor of the lower third of esophagus. Pathologic examination showed an infiltrating small cell carcinoma, and immunohistochemical analysis proved it to be neuroendocrine. The patient died 2 months later from respiratory failure related to pleuritic metastases. Review of the 162 previously published cases showed a mean survival of 6.2 months, and rapid dissemination of metastatic disease, as in our case. As for small cell bronchial carcinoma, systemic chemotherapy should be considered for neuroendocrine carcinoma of the esophagus.

Palatoplasty: a comparative study.

A comparative analysis of 275 patients who underwent palatoplasty between 1961 and 9171 is presented. Of these, 149 patients had a Langenbeck palatoplasty and 188 a V-Y pushback palatoplasty. Speech results in these patients were carefully assessed by experience speech pathologists using conversational and structured (word articulation tests) speech, manometric ratios, and radiographic evidence of palatal movement. Over all, 73% of the V-Y pushback patients attained acceptable speech compared to 56% in the Langenbeck category. Patients with clefts of the soft palate only had the highest incidence of acceptable speech (91% in Langenbeck, 81% in V-Y). In both categories the results were poorer in the more extensive clefts.