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Biomedical subjects

J Diaz

Publications and source records attributed to J Diaz.

At least 235 records · Page 13Linked to original sources
PubMed1976

Exaggerated avoidance of novel stimulation in rats partially recovered from central norepinephrine damage.

Rats in which central norepinephrine lesions are made with 6-OHDA and a recovery period allowed show a behavioral syndrome distinct from controls, from rats with more extensive norepinephrine damage (lesioned with 6-OHDA, allowed to recover, and relesioned), and from rats with general depletion of serotonin (chronic PCPA). These rats administered central 6-OHDA injections and then allowed a recovery period rear less in open field than all other groups and are characterized by an exaggerated avoidance of novel visual stimulation in light onset and light escape tests. It is proposed that this reflects the hyperresponsivity of partially repaired, supersensitive norepinephrine circuitry to novel or intense stimulation.

Animals↗
PubMedDate not supplied

Somatostatin analogs: correlation of receptor affinity with inhibition of cyclic AMP formation in pancreatic acinar cells.

Somatostatin inhibited secretin-stimulated cyclic AMP formation in pancreatic acinar cells. The inhibition was only partial. Maximal inhibition reached about 50%. Somatostatin analogs tested inhibited secretin-stimulated cyclic AMP formation with a lower potency than somatostatin. Cys-Aza Ala-Phe-Phe-DTrp-Lys-Thr-Phe-Phe-Cys was found to be an antagonist of somatostatin in inhibiting secretin-stimulated cyclic AMP. Analogs inhibited the binding of 125I-[Tyr11] somatostatin to pancreatic acini. There was a good correlation (r = 0.97) between concentration for inhibiting 50% secretin-stimulated cyclic AMP and receptor binding affinities.

Amino Acid Sequence↗
PubMedDate not supplied

Artificial rearing alters development of the nucleus of the solitary tract.

Previous studies have shown that damage induced to fungiform papillae of the anterior tongue at postnatal day 2 (P2) alters both pre- and postsynaptic development of gustatory recipient zones within the rostral nucleus of the solitary tract (NST). The present study was conducted to determine whether or not artificial rearing (AR) manipulations, which reduce normal orochemical stimulation during early postnatal development, would be sufficient to produce alterations in anatomical development of the rostral gustatory NST. Two groups of Long-Evans hooded rats were examined. One group received normal rearing with a lactating dam from birth to weaning (mother reared; MR). A second group of animals received artificial rearing via intragastric cannulae between the ages of P4 and P14, and were thereafter returned to lactating dams until the age of weaning (P21). Following weaning and maturation to adulthood (P49), the organization of gustatory afferent terminal fields in the NST was examined using fluorescent tracing procedures which permit the simultaneous visualization of gustatory afferent terminal fields arising from the seventh and ninth cranial nerves. Results show that AR manipulations between the ages of P4 and P14 produce alterations in development of gustatory afferent terminal fields in the NST that are essentially similar to those observed following early postnatal receptor damage. These results confirm previous suggestions that orochemical stimulation during a limited portion of rats' postnatal life is essential in inducing normal presynaptic development in the gustatory NST.

Afferent Pathways↗
PubMedDate not supplied

Iron deficiency in the acute-phase reaction after open aortic surgery.

The objective of this study was to quantify the magnitude of iron deficiency in the postoperative period after open aortic surgery. This was a prospective observational study in 55 consecutive patients. Blood samples were obtained on postoperative days 1, 2, 4, 30, and 45, and the parameters determined were the following: iron, transferrin, transferrin saturation index, transferrin-soluble receptor, ferritin, red cell count, hemoglobin, hematocrit, serum C-reactive protein, fibrinogen, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and number of blood units transfused. We performed statistical ANOVA test for repetitive measurements (lower bound) in regard to its basal level. Iron deficiency and its parameters reached the maximum at 48 hours postoperatively (iron: 18.92 g/dL and transferrin saturation index: 11.1%) (P <.05). There was not a complete recovery after 45 days (iron: 51.23 g/dL and transferrin saturation index: 18.0%) (P <.05). A similar evolution was observed in the other measured parameters (red cell count: 3.5 x 106/L.; hemoglobin: 10.4 g/dL; hematocrit: 30.7%) (P <.005), none affecting the values of concentration or volume (P <.05). Transferrin-soluble receptors, normal at first, were increased at postoperative days 30 and 45 (2.7 and 2.4 mg/dL respectively, P <.005). After open aortic surgery there is an important acute-phase reaction, a dramatic iron deficiency, and a lack of its transporters until the 45th analyzed day. The elevation of transferrin-soluble receptors in the 4th and 6th weeks denotes a necessity of iron supplementation for a correct development of the immature hematic cells since blood parameters do not reach normal levels in the 6th postoperative week.

Acute-Phase Reaction↗
PubMedDate not supplied

[Evaluation of dipotassium clorazepate in pre-anesthetic medication].

The anxiolytic action of clorazepate 15 mg PO on the eve and 1 hour before the surgical procedure was studied in 50 ASA class 1 patients (18-60 years old, 46-86 kg) scheduled for elective non-oncological surgery. Anxiety, assessed by the anaesthetist employing a modified Hamilton Anxiety Scale, was lower after premedication in 46 patients (p less than 0.01) and only few side-effects were noted. As a conclusion we suggested that clorazepate PO as anaesthetic premedication is suitable for anxiety relief.

Adult↗