Dietary L-tryptophan modulates agonistic behavior and brain serotonin in male dyadic contests of a cichlid fish.

Although some studies have investigated the effects of dietary L-tryptophan on agonistic behavior, research on adult fish specimens is still lacking. Moreover, submissive behaviors have been generally overlooked. We focused on agonistic behavior between males of the cichlid fish Cichlasoma dimerus, in dyadic encounters held in a novel context after being fed or not with an L-tryptophan enriched diet (TRP) for 2 weeks. We arranged three different dyads: control/control (control conditions: not TRP enriched), control/TRP, and TRP/TRP. We also registered the response of the brain serotonergic system in four brain regions. TRP/TRP dyads showed higher latencies to first attack, lower overall aggression, and lower proportions of bites and passive copings (submissive display) compared to control/control. TRP dominant males performed fewer bites with respect to controls, and subordinate males opposed to TRP males showed fewer passive copings. Higher serotonergic activities were found in subordinates' optic tectum and in the telencephalon and preoptic area/hypothalamus of TRP males. Altogether, results point out that dietary L-tryptophan reduced males' motivation to attack and dominant aggression, which consequently influenced subordinate agonistic repertory. In addition, males within TRP/TRP dyads showed a switch in their behavioral agonistic repertory. These behavioral outcomes were probably due to modifications at brain serotonergic functioning.

The pineal complex in the cichlid Cichlasoma dimerus: effect of different photoperiods on its cell morphology.

This research describes the pineal complex histology in juvenile and adult Cichlasoma dimerus, and the effect of different photoperiods on its cell morphology. In both juveniles and adults, the pineal complex of C. dimerus has three components: the pineal organ, consisting of a pineal vesicle (PV) and a pineal stalk, the parapineal organ and the dorsal sac. Although a strong morphological resemblance exists between the two stages, different synthesis patterns of cone and rod opsins were detected in the two life stages. An effect of the photoperiod length was observed on putative pinealocytes' activity from the PV, measured indirectly through nuclear area morphometry. Individuals exposed to a natural photoperiod (14L:10D) had smaller nuclear areas (mean ± s.e. = 13·82 ± 1·52 µm(2) ) than those exposed to a short photoperiod (8:16) (21·45 ± 2·67 µm(2) ; P < 0·001). Eventually, the nuclear area of pinealocytes could be used as a putative indicator of melatonin synthesis in fishes where it is difficult to obtain plasma samples, e.g. due to its small size or age. This work constitutes one of the few comparative descriptions of the pineal complex of juvenile and adult teleost and suggests potential approaches for the study of melatonin synthesis in fish larvae or small adult fishes.

Free radical-induced lipoperoxidation and severe head injury. A clinical study.

Ten severely head injured patients (GCS less than or equal to 8), aged 17-62 years, were studied in order to investigate the role of lipoperoxidation in secondary brain damage. No patients had intracranial mass lesions, shock, hypoxemia, fever or sepsis. Blood samples were taken from the jugular bulb and from the right atrium, and thiobarbituric acid reacting substances (TBARS) were measured in plasma by spectrophotometry. Arterio-jugular venous oxygen differences (AVDO2) were obtained in seven patients, in order to estimate cerebral blood flow. Jugular TBARS (TBARSj) were always elevated (from To, to 2 h after injury) and correlated in a linear fashion with TBARS of right atrium (TBARSv): r = 0.74, p less than 0.001. TBARSj and AVDO2 are closely correlated, in accordance with an exponential function (R = 0.45, p less than 0.001) which describes how any cerebral perfusion derangement determines high levels of TBARSj, confirming lipoperoxidation as a key factor in the final common pathway of secondary posttraumatic brain damage.

[The transcutaneous method of monitoring partial pressure of O2 and CO2 during laser surgery of the trachea and bronchi]. / La metodica transcutanea nel monitoraggio della tensione parziale di O2 e CO2 durante laserterapia delle vie tracheobronchiali.

Anesthesia during Nd-YAG laser resection of the airways necessitates continuous O2 and CO2 monitoring. Although only partial, monitoring may be performed using a transcutaneous method utilising Clark's electrode to measure O2 and Stowe-Severinghaus' electrode to assess CO2 on the skin surface. The paper evaluates the advantages and limits of this form of monitoring during anesthesia in 85 patients undergoing laser resection of the airways. In conclusion, in spite of the fact that it is currently impossible to build up a complete picture of blood gas status from a single transcutaneous finding, the use of the transcutaneous method increases the level of safety of the operation as a whole.

[Nutritional studies in a commune of Lazio. Anthropometric data and food consumption in childhood]. / Indagine nutrizionale in un comune del Lazio. Dati antropometrici e consumi alimentari in età scolare.

The present study concerns with anthropometric and nutritional data collected in the school population of a small rural town in Lazio. We studied 368 school-children of both sexes, belonging to the following age groups: from 7 to 8 years, 9 to 10 years, 11 to 12 years, 13 to 14 years. The technique of evaluation of obesity used in this paper is: weight 20% higher than the height-adjusted figure according to NCHS's curves and triceps skinfold higher than 90 degrees centile according to Tanner's curves. Dietary intake was assessed by a "24 hour-recall" on three consecutive days one of which of holiday. The prevalence of obesity is 17.7%. In all the age groups daily caloric intake is adjusted to that recommended by Italian 1987 Larn. On the other hand the single nutrient's assumption shows important differences from Larn. Particularly in all the age groups daily protein intake is high (14.6%-15.8% of the energy in a day), with an increased animal-vegetable protein ratio (1.5-2.1). Dietary lipids are higher than 35.9% of day's energy (35.9%-39.5%); the polyunsaturated/saturated fatty acids ratio is low (0.3-0.5). Cholesterol in the diet (231-347 mg/day) exceeds the level recommended. The daily intake of total carbohydrates (45.3%-48.5%) is low. Crude fiber intake increases with age from 2.8 g to 4.5 g/day. There is no statistical difference between obese and not obese subjects for what concerns energy intake or single nutrient's assumption.(ABSTRACT TRUNCATED AT 250 WORDS)