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Biomedical subjects

J Garcia

Publications and source records attributed to J Garcia.

At least 397 records · Page 22Linked to original sources
PubMed1983

Developmental flavor experience affects utilization of odor, not taste in toxiphobic conditioning.

Feeding experiences were varied in developing rats and the effects upon flavor neophobia and lithium chloride-induced flavor aversions were observed. In Experiment 1, nursing experience of neonate rats was reduced by artificial feeding via intragastric cannula; the rats then were tested with apple juice paired with lithium chloride injection at weaning or maturity. Conditioned aversions were not affected, but neophobia to novel apple juice was attenuated in artificially-reared rats tested at maturity. In Experiment 2, rats received enriched feeding experience after weaning, which consisted of (a) obtaining many complex flavors, a few of which were paired with poisoning, effortlessly in the home cage, or (b) foraging for various foods on an elevated maze. No dramatic effects on neophobia or conditioned taste aversion for saccharin water were apparent. In Experiment 3, rats were given experience after weaning with vanilla-scented water either paired or unpaired with quinine water, and then tested with the odor of almond or that odor compounded with saccharin water for neophobia and lithium-induced aversions. Flavor-experienced rats exhibited more pronounced odor conditioning and more resistance to extinction of the odor aversion after both simple and compound conditioning. In contrast, saccharin taste aversions were relatively unchanged. Apparently, enriched feeding and drinking experience facilitates the utilization of odor more than taste cues.

Animals↗
PubMed1983

Flavor-illness aversions: potentiation of odor by taste is disrupted by application of novocaine into amygdala.

Taste and odor have different properties in toxiphobic conditioning. When each is used alone, taste becomes aversive when followed by immediate or delayed poison, while odor becomes aversive only if followed by immediate poison. However, if odor and taste are presented as a compound and followed by delayed poison, then odor does become aversive when tested alone. It is as if taste has potentiated the odor signal. Several experiments assessed the role of the amygdala in this potentiation effect by anesthetizing the amygdala with 10% novocaine. Novocaine applied 30 min before presentation (Pre-CS) of an odor-taste compound disrupted the potentiated odor aversion but not the taste aversion. In contrast, novocaine applied 1 min after the compound odor-taste or 1 min prior to LiCl poison did not dissociate odor and taste aversions; both odor and taste aversions were facilitated. Novocaine applied 30 min before an odor alone also disrupted an odor aversion induced by immediate LiCl. But identical treatment did not disrupt odor avoidance conditioned by immediate foot-shock, suggesting that amygdala anesthesia does not simply produce anosmia. Pre-CS novocaine treatment also disrupted flavor neophobia prior to conditioning. The results suggest that novocaine applied to the amygdala disrupts the integration of odor with taste and illness during toxiphobic conditioning.

Amygdala↗
PubMed1983

[Pneumopathies caused by Chlamydia trachomatis in pediatrics].

Chlamydia trachomatis now has an important place in infantile respiratory pathology. In neonates, it is transmitted in utero, which explains one quarter of the cases of interstitial pneumonia seen during the first months of life. In children, the number of carriers of antibodies increases with age and may be more than 40 p. cent by the age of 7 years. The mode of contamination and the pathological significance remain uncertain in this age group. Chlamydia trachomatis can be a cause of pneumonia in immuno-depressed patients. A survey conducted in a Paediatric Respiratory Medicine Unit showed that 22 p. cent of patients were carriers of the antibody and at least 7.8 p. cent were infected.

Adolescent↗
PubMed1983

[Congenital hemolytic anemia with erythrocyte thermal instability and defect of spectrin tetrameric polymerization. Study of erythrocyte deformability in a new case of hereditary pyropoikilocytosis using diffraction viscosimetry].

Hereditary pyropoikilocytosis (HPP) is a rare congenital hemolytic anaemia observed so far in patients of black extraction. In many cases, the severity of the anaemia has led to early splenectomy, which uniformly improved the hematological conditions. The disease is characterized by extreme anisocytosis and poikilocytosis with erythrocyte fragmentation. The pathognomonic feature is the abnormal thermal sensitivity of red cells which fragment in vitro at 45-46 degrees C (instead of 49 degrees C in normal subjects). In the case reported here, erythrocyte fragmentation (which appears at 43 degrees C) and increased osmotic fragility are studied using the Ektacytometer. Observation of different erythrocyte fractions isolated by differential centrifugation shows the extreme heterogeneity of the erythrocyte population. Studies of erythrocyte membrane proteins confirm that the disease is related to defective dimer-dimer association of spectrin which is the major membrane skeletal protein. This molecular spectrin abnormality in accounting for the membrane instability is recognized to a lesser degree in the asymptomatic mother. This may be of use in the diagnosis of HPP which is difficult to establish in a transfusion-dependent infant.

Anemia, Hemolytic, Congenital↗
PubMed1982

A technique for the aspiration of oocytes from human ovarian follicles.

A variety of techniques have been described for the harvest of oocytes from human ovarian follicles. Most of these have used needles with an inside diameter in the range of 1.0 to 1.4 mm. Because of the physical characteristics of preovulatory cumulus mass, it was considered possible that a needle with a somewhat larger inside diameter would be useful. This has proven to be the case. With such a needle, in 18 natural cycles it was possible for these investigators to obtain an oocyte in 17 patients; and in 23 patients with cycles controlled by human menopausal gonadotropin and human chorionic gonadotropin, it proved possible to obtain at least 1 oocyte from 22 patients.

Cell Separation↗
PubMed1982

Flavor-illness aversions: potentiation of odor by taste with toxin but not shock in rats.

Potentiation of odor by taste in rats was tested in a variety of situations. In three experiments, almond odor and saccharin taste were presented either as a single conditioned stimulus (CS) or as a compound CS and followed by either toxic lithium chloride or footshock. Extinction tests with the almond and saccharin components were then given. In single CS-toxin experiments, taste was more effective than odor, and after compound conditioning, the taste component potentiated the odor component. Conversely, in single CS-shock experiments, odor was more effective than taste, and after compound conditioning, no potentiation was observed. Rather, interference effects were observed. In Experiments 1 and 2, the addition of taste disrupted odor CS-shock conditioning, and in Experiment 3, odor interfered with taste CS-shock conditioning. Visceral feedback is apparently a necessary unconditioned stimulus for the potentiation of odor by taste. These data support the neural convergence and gating hypothesis of flavor aversion conditioning.

Animals↗
PubMed1982

Flavor-illness aversions: gustatory neocortex ablations disrupt taste but not taste-potentiated odor cues.

Two experiments evaluated the contribution of the gustatory neocortex (GN) to the potentiation of odor by taste during illness-induced aversions in rats. In Experiment 1, rats lacking GN and control rats were given an odor, a taste, or an odor-taste compound cue followed by intragastric gavage of lithium chloride. Prior to conditioning, neophobia for flavored solutions was absent in rats with GN lesions. After pairing with LiCl, GN rats developed normal conditioned odor aversions (Experiment 1B), whereas conditioned taste aversions were attenuated (Experiment 1A) or totally blocked (Experiment 1B). Potentiation of odor by taste after compound conditioning was evident in both control and GN rats, although GN lesions attenuated the effect slightly in Experiment 1B. In Experiment 2, normal rats were given compound conditioning to induce potentiated odor aversions and then given GN lesions prior to tests with the odor and taste components. Taste aversion retention was disrupted totally by GN ablation; potentiated odor aversions were retained by both groups, although the GN group extinguished faster. Gustatory neocortex ablations produced differential effects on odor and taste, disrupting taste memorial and associative processes but leaving odor conditioning and the potentiation of odor by taste processes relatively unaffected. Integrity of the GN apparently is not necessary for the acquisition or retention of potentiation odor aversions.

Animals↗
PubMed1982

Potentiation of odor by taste in rats: tests of some nonassociative factors.

The contribution of nonassociative neophobia and sensitization to the potentiation of odor by taste in rats was tested in three experiments. In Experiment 1, neophobia for almond odor (O), saccharin taste (T), and odor-taste compound (OT) cues was tested before and after noncontingent lithium chloride poisoning and compared with conditioned aversions produced by OT-LiCl temporal pairing. The OT compound potentiated unconditioned neophobia, but there was no evidence of poison-enhanced neophobia, disinhibition of neophobia, or sensitization by noncontingent LiCl; temporal pairing produced aversions for the compound and its elements. In Experiment 2, generalization to a novel odor was tested after O-LiCl or compound OT-LiCl pairing. The potentiated odor aversion did not generalize to the novel odor; it was specific to the odor paired with taste and LiCl. In Experiment 3, potentiation of the odor component by a discriminant or nondiscriminant taste component was tested. Potentiation was evident only when a novel discriminant taste was in compound with odor prior to LiCl poisoning. These studies support an associative "indexing" hypothesis of the potentiation effect in rats.

Animals↗
PubMed1982

The program for in vitro fertilization at Norfolk.

Several aspects of the program of in vitro fertilization (IVF), or, as it is called in Norfolk, the program for the Vital Initiation of Pregnancy (VIP), have been or are in the process of publication. However, because there has been no overall account, it seems appropriate to give a brief report of a general nature covering the period from the beginning of the effort in late February 1980 through December 31, 1981. Although minor changes were constantly made in the protocol, there were two major revisions. Therefore, a discussion of the program during three distinct periods, i.e., 1980, 1981-Phase I, and 1981-Phase II, is necessary. During 1980 and 1981 all patients had either no fallopian tubes or irreparable tubes.

Adolescent↗
PubMed1981

Isovolumetric partial exchange transfusion in the management of sickle cell disease in pregnancy.

A technique that permits isovolumetric partial exchange transfusion is presented, with experience from 10 partial exchange transfusions in five obstetric patients with sickle cell disease. The technique is performed in an outpatient setting and requires less than two hours once blood has been cross matched. A mathematical model of the blood volume is used to predict final hematocrit and final hemoglobulin (Hgb) A percentage and to compare this technique with a previously described algorithm. Once the decision to perform a partial exchange transfusion has been made, this technique affords diminished risk to the patient and economy of time and money by permitting prediction of the hematocrit and percentage normal hemoglobin (% Hgb A) resulting from various transfusion/withdrawal volumes.

Anemia, Sickle Cell↗
PubMed1981

[Renal osteodystrophy in patients on maintenance hemodialysis: statistical study of clinical, radiological and biochemical features].

Sixty radiological, clinical and biochemical features were simultaneously recorded in a population of 46 patients on maintenance hemodialysis. Radiological signs of bone reabsorption (hands, acromio-clavicular and sacro-iliac joints) were demonstrated in 65% and were quantified as a radiological index of hyperparathyroidism. The index was correlated with the levels of parathormone and of alkaline phosphatase (p less than 0.01) and with the duration of renal failure (p less than 0.01), and inversely related to bone densitometry (p less than 0.05). Discriminant analysis confirmed the redundant value of parathormone and alkaline phosphatases in predicting bone lesions. Factorial analysis showed the existence of 12 classes of patients statistically close to one another. These results demonstrate the heterogeneity of renal osteodystrophy.

Bone and Bones↗
PubMed1981

The sinus tarsi syndrome.

The sinus tarsi syndrome is now a well-defined entity of foot pathology. Usually post-traumatic, it is characterised by pain over the lateral opening of the sinus tarsi and a feeling of instability of the ankle. We were able to define two objective criteria for the syndrome: arthrography of the subtalar joint shows specific abnormalities and recording of the electromyographic function of the peronei demonstrates abnormalities during walking. Conservative treatment is successful in about two-thirds of the cases. In other cases a simple surgical procedure can cure or improve 90% of the patients.

Adolescent↗
PubMed1981

Inverse relationship between onset and duration of EEG effects of six peripherally administered peptides.

Electrical activity in the rat brain after the peripheral injection of equimolar (0.1 mM) doses of Metenkephalin, Leu-enkephalin, beta-endorphin, gamma-endorphin, DSIP, and alpha-MSH was assessed by power spectral analysis. The mean onset of EEG activity for each peptide varied between 13.7 and 20.7 minutes and lasted between 27.8 and 40.8 minutes. The significant (p less than 0.001) interaction between duration and latency revealed that the longer the latency, the shorter the duration. Similar findings were observed after injection of the same peptides at a fixed dose of 80 microgram/kg body weight. Thus, the results demonstrate that peripherally injected peptides can exert EEG effects that last longer the sooner they start.

Animals↗
PubMed1981

Corpus luteum function after follicle aspiration for oocyte retrieval.

Follicle aspiration for in vitro fertilization is associated with a statistical disruption of the luteal phase. The severity of the disruption seems to be in relation to the vigorousness and the number of aspirations and therefore the number of granulosa cells that are dislodged from the membrana granulosa layer. Although the statistical importance of this disruption from a biologic point of view does not seem to be significant, as measured by the length of the luteal phase, an analysis of individual cases must be made in order to determine the frequency with which a biologically significant luteal defect may be produced. At the present time, it seems that the fewer the granulosa cells removed at aspiration, the less the luteal disruption will be. The series is discounted as an important factor in inducing luteal dysfunction.

Corpus Luteum↗