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Biomedical subjects

A Loizzo

Publications and source records attributed to A Loizzo.

79 records · Page 5Linked to original sources
PubMedDate not supplied

MIF-1 can accelerate neuromotor, EEG and behavioral development in mice.

Newborn mice were injected SC daily with 1 mg/kg of MIF-1 or saline during the first 19 days of life. The progress of each pup was monitored for physical (body weight, eye and ear opening), neurobehavioral (reflexes) and neurophysiological (EEG) development until the weaning stage. In early adulthood (40 days of age) mice were tested on a maze learning task. Results indicate that MIF-1 can accelerate neurologic (days 3-9), somatic (days 10-14) and electroencephalographic (days 16-19) parameters, and that the effects of treatment last into the early adult stage with increased learning abilities in an appetitive task.

Amino Acid Sequence↗
PubMedDate not supplied

Chronic treatment with MIF-1 prevents the painful stimuli threshold elevation induced by neonatal handling in mice.

Chronic postnatal stressful handling results in a hyposensitivity to thermal nociceptive stimuli. This phenomenon is strongly affected by manipulations of the opioid system. In the present experiment, we report that chronic treatment with MIF-1 during the neonatal period prevents the behavioral alterations induced by handling while it is completely ineffective if injected acutely before antinociceptive testing by the tail flick test at 45 days of life.

Amino Acid Sequence↗
PubMedDate not supplied

Evolution of daytime quiet sleep components in early treated phenylketonuric infants.

The maturational patterns of 'tracé alternant' (TA) and sleep spindles obtained from 16 early detected phenylketonuric (PKU) children during their first months of life were compared with others that were evaluated in recordings taken from 42 controls of the same age group. The TA maturation evolved significantly later in the PKU group than in the control group during the 5th-8th week (the TA score for the PKU group was 64% vs. 10% in the control group, P < 0.001). Afterwards, during the 9th-12th week the score for the PKU group was 27% vs. 0% in the controls (P < 0.002). The sleep spindle evolution score also matured significantly later in the PKU than the control group: the score was 31% in PKU children vs. 85% in controls for the 5th-8th week of age (P < 0.01), and it was 66% vs. 96% for the 9th-12th week (P < 0.02). After the 12th week, TA pattern could not be detected, and spindles reached complete maturation in the PKU children as well. Our results show a consistent delay in the maturation of TA and spindle scores in PKU children. This trend of delay is parallel to the plasma phenylalanine normalization, but not necessarily dependent only on it. In conclusion, we suggest that studies on the critical maturational periods of different sleep components (TA and sleep spindles) might provide a sensitive tool for early diagnosis of neurophysiological brain alterations during the first trimester of life in a population of children "at risk'.

Circadian Rhythm↗
PubMedDate not supplied

Effects of endorphin derivatives on the EEG alterations induced by corticotropin releasing factor in the rabbit hippocampus.

Corticotropin releasing factor (CRF), injected into the cerebral ventricles (i.c.v.) of rabbits, induced EEG limbic seizures, behavioural excitability, stereotyped behaviour and the tardive enhancement of hippocampal theta voltage and frequency. The beta-endorphin cleavage derivatives des-tyr-gamma-endorphin (DT gamma E) and des-enkephalin-gamma-endorphin (DE gamma E), when injected i.v. for 4 days prevented the EEG ictal seizures induced by CRF in the hippocampus of rabbits and partly prevented the tardive enhancement of theta wave amplitude and frequency. These results suggest the possibility that these peptides may have antiepileptogenic properties.

Animals↗
PubMedDate not supplied

Relay activity of 17-beta oestradiol and diethylstilbestrol in a mouse-rat system.

The biological activities of diethylstibestrol (DES) of 17 beta-oestradiol (17 beta E) were initially tested, based on the uterus enlargement induced by different doses given with food to immature female mice. In a second series of experiments, the drugs were given in higher doses per os to rats (relay animals) and after 24 h, the livers of the relay rats were removed. Parts of the livers were freeze-dried and were added (10% w/w) to the food of immature female mice, while the remainder underwent chemical analysis to determine the DES and 17 beta E content. When given directly to mice with their food, DES showed about six times more biological activity than 17 beta E. When given through the livers of relay rats, the biological activity of the livers from DES-and 17 beta E-treated relay rats was of the same magnitude. The content of 17 beta E in the livers of relay rats was 10-20 times higher than the DES. Such concentrations corresponded directly to the biological activity of livers. These data show that the bioavailability and the relative potency of xenobiotic drugs and natural hormones may be profoundly altered after passing through metabolic pathways, and may give useful indications for the evaluation of biological activity of residues and contaminants and their metabolites in the food.

Animals↗
PubMedDate not supplied

Some endorphin derivatives and hydrocortisone prevent EEG limbic seizures induced by corticotropin-releasing factor in rabbits.

Corticotropin-releasing factor (CRF) injected into the cerebral ventricles of small mammals induces EEG limbic seizures, behavioral excitability, stereotyped behavior, and tardive enhancement of hippocampal theta voltage and frequency. Because we addressed this phenomenon when we explained the pathogenesis of infantile spasms in children, we wished to study the interference exerted by some gamma-endorphin fragments on EEG epileptiform and behavioral symptoms induced by CRF in the rabbit. Animals were implanted intracerebroventricularly (i.c.v.) with semichronic cortical and hippocampal electrodes, together with a cannula into the left lateral ventricle. When some gamma-endorphin derivatives (DT gamma E, DE gamma E) were injected intravenously (i.v.) for 4 days (or hydrocortisone once), they prevented the EEG ictal seizures induced in the hippocampus of rabbits by CRF injected i.c.v. Hydrocortisone and DE gamma E also prevented the appearance of scattered spiking and partially prevented tardive enhancement of theta voltage in the hippocampal EEG. Finally, DE gamma E also prevented stereotyped behavior and excitability induced by CRF. These results confirm the regulatory role exerted by CRF in limbic structure excitability and suggest that the above peptides may be involved in a regulatory feedback mechanism of CRF metabolism or activity. The possibility that these peptides may also have interesting antiepileptogenic properties should be considered.

Animals↗