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Biomedical subjects

P A Serrano

Publications and source records attributed to P A Serrano.

At least 19 recordsLinked to original sources
PubMed1995

Protein kinase inhibitors disrupt memory formation in two chick brain regions.

The amnesic effects of protein kinase inhibitors (H-7, HA-156, TFP, W-9, and W-13) on memory formation for a one trial peck-avoidance task in chicks were investigated with bilateral and unilateral injections into either the left or the right intermediate medial hyperstriatum ventrale (IMHV) or the left or right lobus parolfactorius (LPO). All five inhibitors injected bilaterally 5 min pretraining into either the IMHV or LPO or unilaterally into the left IMHV produced amnesia. Unilateral injections into the right IMHV did not produce amnesia. Unilateral injections of W-9 or W-13 into the left but not the right LPO produced amnesia, H-7, HA-156, or TFP did not produce amnesia when injected unilaterally into either the left or right LPO. The time of onset of amnesia produced by injecting TFP and W-13 into the LPO occurred 45 min after training, whereas H-7 produced amnesia significantly later (90 min after training). Amnesia induced by TFP, W-13, and H-7 injected into the LPO occurred significantly later than amnesia produced when these agents were injected into the IMHV. Together these data suggest that the IMHV and LPO process memory sequentially using various protein kinase activities.

Animals↗
PubMed1995

Protein kinase C inhibitor chelerythrine disrupts memory formation in chicks.

Chelerythrine (CHELE), a specific, potent protein kinase C (PKC) inhibitor, disrupts memory formation for a one-trial peck-avoidance task. Three predictions were made about how CHELE, injected into chick brain near the time of training, would affect memory formation, based on previous work with two classes of protein kinase inhibitors (M. R. Rosenzweig et al., 1992; P. A. Serrano et al., 1994) and the in vitro inhibition of PKC by CHELE: (a) CHELE, injected into the intermediate medial hyperstriatum ventrale, would significantly impair memory formation; (b) the amnestic dose would be approximately 10 nmol; (c) CHELE would not produce amnesia for about 45 min after training, but significantly impair memory by 60 min. Experimental tests confirmed each prediction. This study adds to evidence that PKC activity is part of a cascade of neurochemical events initiated by learning and that PKC activity shortly after training is necessary for long-term memory.

Alkaloids↗
PubMed1994

Differential effects of protein kinase inhibitors and activators on memory formation in the 2-day-old chick.

Thirteen protein kinase inhibitors (PKIs) were investigated in chicks for their in vitro effects on PKC activity and for their in vivo effects on memory formation for a peak-avoidance task. Amnesia occurred by 15-30 min post-training when agents that inhibit primarily Ca2+/calmodulin were injected into brain. Amnesia occurred by 60 min post-training when agents that inhibit PKC-, PKA-, and/or PKG-dependent protein kinases, but not Ca2+/calmodulin, were injected. Enhancement of memory formation was accomplished by injecting bradykinin, but not forskolin. Both of these agents, however, attenuated the amnesia produced by H-7. These results are discussed as relevant neural processes involved in memory and synaptic plasticity.

Amnesia↗
PubMed1994

[Carcinoma of the esophagus: risk factors of morbimortality following esophagectomy].

OBJECTIVE: To identify which perioperative risk factors are associated to postoperative morbidity and mortality in patients with carcinoma of the esophagus. DESIGN: We analyzed 8 perioperative risk factors: age, preoperative hospital stay, intraoperative blood transfusions, tumor stage, histology, grade of tumor differentiation, prior respiratory disease, surgical treatment. PATIENTS: Forty-six patients with esophageal carcinoma who underwent surgical resection. RESULTS: 1) Morbidity: There was statistical significance between the increase in postoperative morbidity and age > 75 years (p < 0.001), advanced stage of disease (p < 0.001), preoperative hospital stay higher than 20 days (p < 0.05) and severe respiratory disease (p < 0.05). 2) Mortality: There was a statistically significant increase in postoperative mortality in patients with preoperative hospital stay higher than 20 days and in patients > 75 years. CONCLUSIONS: The incidence of postoperative morbidity and mortality in esophageal cancer varies according to age, prior respiratory disease, tumor stage and preoperative hospital stay.

Adult↗
PubMed1993

Short-term, intermediate-term, and long-term memories.

This paper focuses on the temporal dimension of memory formation and storage. Is the usual two-fold separation between short-term memory (STM) and long-term memory (LTM) sufficient to encompass all the phenomena of memory? The traditional view is that STM grades into LTM. Evidence for an intermediate-term memory (ITM) has been proposed by some investigators. We have used both rats and chicks to investigate the stages of memory formation. In this paper, the advantages of chicks for this type of research are briefly discussed. Using a paradigm that produces weak training, the retention function for control chicks appears to be made up of four successive components which we have interpreted as representing the memory buffer, STM, ITM, and LTM. In experiments using a variety of kinase inhibitors, we have obtained evidence that ITM and LTM depend on different classes of protein kinase activities. Agents that act on calcium/calmodulin kinase cause amnesia in the ITM range--15 to 30 min post-training. Another class of inhibitors act on one or more of the kinases PKA, PKC, or PKG and cause amnesia by 60 min post-training, so we interpret this group of inhibitors as inhibiting the formation of LTM. However, the three-stage model of memory may be over-simple. For example some agents including [Leu]enkephalin and MK801 cause amnesia 4 or more h after training.(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1993

[Determination of the tumor marker CA 72-4 in gastric carcinoma].

In this study, the authors determined the sensitivity and specificity of the new tumor marker CA 72-4 in detecting adenocarcinoma of the stomach. CA 72-4 serum levels were investigated in 279 patients consisting of: 100 control subjects, 88 patients with benign gastrointestinal disease and 91 patients with gastrointestinal cancer (31 with gastric cancer). We used a cut-off of 5 U/ml. The specificity of CA 72-4 was 91% and the sensitivity was 68%. Highest levels of CA 72-4 were found in patients with more advanced tumor (stages III-IV) and four of 5 patients with stage I had elevated levels of this tumor marker. These findings suggest that the use of serum CA 72-4 measurements may be more useful than other tumor markers in the diagnosis, prognosis and detection of recurrence in patients with gastric cancer. Although CA 72-4 can be elevated in other gastrointestinal adenocarcinomas, it can be useful in alerting the clinician to the possible presence of an intraabdominal neoplasm.

Adenocarcinoma↗
PubMed1992

Comparative study of roles of the lobus parolfactorius and intermediate medial hyperstriatum ventrale in memory formation in the chick brain.

Two discrete areas of the chick brain, the intermediate medial hyperstriatum ventrale (IMHV) and lobus parolfactorius (LPO), were found to have different functions during the formation of memory for a 1-trial peck-avoidance paradigm. Glutamate, ouabain, and emetine, known to disrupt short-, intermediate-, and long-term memory when injected into the IMHV, were injected into the cerebellum and LPO. All amnestic agents investigated produced amnesia when injected into the IMHV; only one of these agents produced amnesia when injected into the LPO, and none of the agents produced amnesia when injected into the cerebellum. The chick brain was also found to exhibit hemispheric asymmetries: The left IMHV and LPO were more sensitive to the amnestic agents than their corresponding right structure. From these data, hypotheses for the roles of these structures during memory are proposed.

Animals↗
PubMed1978

Dopamine excretion in benign pheochromocytoma.

Dopamine excretion is reported in 27 patients with benign pheochromocytoma. In 21 patients the tumours were in the adrenal (one patient, bilateral), four were extra-adrenal, and two were assumed to be so since they were not found at laparotomy. Dopamine excretion was found to be higher in the patients with extra-adrenal tumours and in one patient--with bilateral pheochromocytoma. Slight increase of dopamine excretion was found in two of the remaining patients. These observations--indicate that while increased dopamine excretion may be present in patients with malignant pheochromocytoma it can be also increased in some patients with benign tumours.

Adolescent↗
PubMed1975

Energy metabolism and hormonal profile in children with edematous protein-calorie malnutrition.

Modifications in energy metabolism and endocrine homeostasis (plasma insulin and growth hormone values, glucose and free fatty acid levels, serum thyroxine and TSH, free thyroxine index, and urinary catecholamines) were investigated in eight children with edematous protein-calorie malnutrition. Caloric expenditure was low at admission and correlated linearly with increased caloric intake throughout the study. The hormonal changes at admission were characterized by a negligible insulin response to intravenous arginine or glucose and by markedly elevated growth hormone levels which were neither increased by arginine nor suppressed by intravenous glucose. Serum thyroxine values were low, but free thyroxine index and serum TSH levels were within normal limits. At admission to the study, 24-hour urinary excretion of dopamine and norepinephrine was relatively reduced in relation to the excretion of epinephrine. All these modifications were corrected at time of the recovery study. It is suggested that in edematous protein-calorie malnutrition, insulin acts as the primary regulator of peripheral fuel release and that the high, nonsuppressible growth hormone levels may form part of an important homeostatic mechanism to provide substrates for brain metabolism via lipolysis.

Anthropometry↗