Search PubMed⌕ Search

Biomedical subjects

E Fernandez

Publications and source records attributed to E Fernandez.

At least 217 records · Page 12Linked to original sources
PubMed1990

On the putative uniqueness of cancer pain: do psychological principles apply?

A large volume of evidence has supported the important role of psychological principles and variables related to the perception of, and response to, nociceptive stimulation. On the basis of this research, a number of psychological interventions have been developed and used successfully with pain patients. Despite the evidence, there has been a tendency for practitioners to neglect the contributing role of cognitive, affective, and behavioral factors in reports of pain by cancer patients. Cancer seems to hold a unique status in medicine and society at large. In this paper, the cancer pain literature is briefly reviewed and evidence is presented for various psychological determinants of the pain report and response that may be extended to pain associated with cancer. The implications of these data for understanding and treatment of cancer patients are described.

Arousal↗
PubMed1990

High potassium concentration and the cumulus corona oocyte complex stimulate the fertilizing capacity of human spermatozoa.

Progressively motile spermatozoa were incubated for 24 hours in culture media containing 4.7 or 25 mM K, in the presence or absence of hamster cumulus oophorus. The percentage of spermatozoa with progressive motility was significantly higher at 24 hours in the presence of cumulus corona oocyte complexes, irrespective of K concentration. A significant decrease in sperm mortality was observed with the association of 25 mM K and cumulus cells. A higher percentage of acrosome reaction was observed in spermatozoa incubated in 25 mM K when compared with 4.7 mM K, irrespective of time and the presence or absence of cumulus. The percentage of penetrated oocytes at 2 and 5 hours of incubation was higher when sperm had been incubated in 25 mM K than in 4.7 mM K. The presence of cumulus in the culture medium induced an additional significant increase in the percentage of penetrated oocyte. Although at 24 hours of incubation the percentage of acrosome reaction was higher than at 2 and 5 hours, the percentage of penetrated oocytes did not increase proportionally.

Acrosome↗
PubMed1990

Changes of soluble CD16 levels in serum of HIV-infected patients: correlation with clinical and biologic prognostic factors.

The modulation of soluble CD16 titers in human immunodeficiency virus (HIV)-infected patients' serum, with an initial increase in Centers for Disease Control (CDC) clinical stage II and III patients followed by a dramatic drop in patients with AIDS (CDC clinical stage IV), is reported. These changes are statistically correlated with the CDC staging system, the number of CD4+ cells, the amount of p24 antigen in serum, and the anti-p24 antibody titers, indicating the potential value of soluble CD16 titer as an easily available serum marker of disease progression. To evaluate a possible link between this observation and the expression of membrane-associated CD16/FcRIII, flow cytometry immunofluorescence analysis was performed on peripheral blood lymphocytes from patients in three CDC stages; no specific changes in the number of natural killer cells expressing CD16+ antigens or in the total number of Leu19+ cells were found. However, there was a statistical correlation between the absolute number of T cells expressing CD16 antigens (CD3+/CD16+) and the modulated titers of soluble CD16 in HIV-infected serum.

Adult↗
PubMed1990

Effects of topically administered nerve growth factor on axonal regeneration in peripheral nerve autografts implanted in the spinal cord of rats.

The effect of exogenous nerve growth factor (NGF) on axonal regeneration into autologous peripheral nerve (PN) grafts implanted to the spinal cord (SC) of rats was assessed by retrograde labeling of the parent soma of the regenerating axons with horseradish peroxidase. NGF was delivered at the graft site over periods of 15 and 30 days by using indwelling osmotic minipumps. In control rats, the minipumps were filled with saline. At 15 days after grafting in the NGF-treated rats, the mean number of SC as well as dorsal root ganglion (DRG) neurons that regenerated their axons into the peripheral nerve grafts was increased 55.3 and 26.4 times, respectively, as compared to the control group values. At 30 days, SC and DRG neurons in the NGF-treated group were 10.9 and 3.1 times greater than in the control group. In the NGF-treated group, the regenerating SC neurons were located within a range of 7 to 13 mm from the graft site as compared to 1 to 7 mm in the control group. Finally, the analysis of the soma diameters of the regenerating neurons showed that NGF enhanced and maintained with time the regenerative response from small-sized DRG neurons. Therefore, NGF is thought to promote directly the regenerative potential of SC as well as DRG neurons and to exert an indirect glial cell-mediated effect at the SC-graft interface.

Animals↗
PubMed1990

The effect of hyperinflation on respiratory muscle strength and efficiency in healthy subjects and patients with asthma.

We evaluated respiratory muscle strength and efficiency in 15 patients with asthma. There was a significant reduction in mean Plmax (89.3 +/- 4.7 versus 110.5 +/- 9.4 cm H2O, p less than 0.001) and efficiency (2.41 +/- 0.2 versus 4.2 +/- 0.6%, p less than 0.01). This reduction in strength and efficiency was seen only in the male patients. Following bronchodilator, there was a significant increase in Plmax (from 89.3 +/- 4.7 to 96.2 +/- 5.4 cm H2O, p less than 0.005) and efficiency (from 2.41 +/- 0.2 to 3.22 +/- 0.2%, p less than 0.001). There was no correlation between the change in strength and efficiency and the degree of improvement in FEV1 following bronchodilator. However, there was a significant correlation with the fall in lung volume. To determine whether hyperinflation would result in a reduction in respiratory muscle strength and efficiency, we induced a mean increase in end-expiratory lung volume of 0.66 L by applying continuous negative pressure around the chest in 10 healthy individuals. This was associated with a significant fall in Plmax (from 110.5 +/- 9.4 to 100.5 +/- 8.93 cm H2O, p less than 0.001) and efficiency (from 4.2 +/- 0.6 to 2.6 +/- 0.5%, p less than 0.005). The data suggest that the strength and efficiency of the respiratory muscles are reduced in asthmatic males but not in the females. The strength and efficiency of the respiratory muscles improve significantly following bronchodilator, and this improvement is related to reduction in lung volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Agonists↗
PubMed1990

Effect of propionyl-L-carnitine on rat spinal cord ischaemia and post-ischaemic reperfusion injury.

In this study we have examined the effect of propionyl-L-carnitine (PC) on rat spinal cord ischaemia and post-ischaemic reperfusion injury by evaluating two lipid peroxidation indices, thiobarbituric acid reactive substances (TBARS) and diene conjugation, before and after the addition of an ADP-Fe+2 complex to spinal cord homogenates. Aerobic, ischaemic, and post ischaemic reperfusion rat spinal cord homogenates from PC treated and untreated animals did not show any statistically significant difference in their TBARS and conjugated diene content. The addition of the ADP-Fe+2 complex to these homogenates resulted in an increased production of both the lipid peroxidation indices, though the magnitude of such formation was related to the type of experimental intervention. The post-ischaemic reperfusion samples of untreated rats showed the highest TBARS and conjugated diene content, while ischaemic samples in either treated and untreated rats did not show any statistically significant difference with respect to the aerobic samples. The post-ischaemic reperfusion samples of treated rats showed a statistically significant decrease of TBARS and conjugated diene production in comparison to the untreated samples. In addition, PC was also able to partially inhibit TBARS and conjugated diene formation in linoleic acid micelles exposed to hemoglobin, though it did not protect albumin fragmentation from the irradiation of water with an X-ray source.

Animals↗
PubMed1990

Study of the parental origin of sexual aneuploidy in ten families using RFLPs.

We have studied 10 families with sexual aneuploidy by means of recombinant DNA techniques. The X linked probes were F814 (DXS52), FIX (FVIII gene), pert 87.15 (DXS164), L754 (DXS84) and 47Z (DXYS5). The observed banding patterns allowed us to determine the parental origin of such aneuploidy in nine of our cases. It was paternal in seven cases and maternal in two.

Cells, Cultured↗
PubMed1990

Effect of acute insulin administration on biliary lipid secretion by the diabetic rat.

The insulin-deficient state induces profound changes in bile formation. The present work was to test the effect of acute insulin administration on lipid secretion into bile in diabetic rats. Diabetes was induced by streptozotocin injection (6 mg/100 g body-weight, i.p., 6 days before the experiments). Bile formation was stimulated by taurocholate infusion (0.5 mumol/min/100 g body-weight). Intravenous administration of insulin (bolus: 100 mU/100 g body-weight, plus infusion: 5 mU/min/100 g body-weight) induced choleresis accompanied by a slight and transient enhancement in bile acid output which was similar to that found in lecithin and cholesterol output in the control group. However, insulin induced a rapid and significant (P less than 0.05) reduction in biliary lipid output in the diabetic rats. These results suggest that insulin may play an important role in mechanisms other than synthesis involved in the supply of biliary lipids towards the canaliculi.

Animals↗
PubMed1990

Studies on the degenerative and regenerative phenomena occurring after transection and repair of the sciatic nerve in rats: effects of acetyl-L-carnitine.

The effects of acetyl-L-carnitine on some degenerative and regenerative phenomena following sciatic nerve transection in rats, were studied. In Experiment 1, acetyl-L-carnitine was administered intraperitoneally at the dose of 50 mg/kg/day for 28 and 56 days following transection and microsurgical repair of the sciatic nerve. On day 56, the acetyl-L-carnitine-treated rats showed a significantly (p less than 0.05) better motor recovery ("clinical assessment") of the peroneal component of the sciatic nerve than the control rats. Twenty-eight days after nerve repair, the acetyl-L-carnitine-treated rats showed a significantly higher (p less than 0.05) number of myelinated axons in the postlesional nerve stump than control rats. Finally, the treated rats had a significantly lower (p less than 0.05) presence of atrophic fibres in the extensor digitorum longus muscle. In Experiment 2 the sciatic nerve was cut. To prevent spontaneous regeneration, a metallic clip was applied to the distal nerve stump and then the nerve stumps were positioned in different anatomical compartments. After surgery, a group of rats was treated with acetyl-L-carnitine dissolved in the drinking water (75 mg/kg/day). Another group of rats received normal water and served as the control group. Three, 6, 9, 12 and 18 months postoperatively, in the rats of both groups, the proximal sciatic nerve stump was injected with horseradish peroxidase to label the spinal cord neurons of the sciatic nerve nucleus. While in untreated rats the number of horseradish peroxidase-labelled neurons decreased with the increase in denervation time, in acetyl-L-carnitine-treated rats the number of horseradish peroxidase-labelled neurons remained stable for as long as 12 months of denervation and decreased only after 18 months of denervation. Furthermore, acetyl-L-carnitine-treated rats showed a significantly higher (p less than 0.05) number of horseradish peroxidase-labelled neurons with respect to untreated rats both after 9 and 12 months of denervation. In Experiment 3, the sciatic nerve was cut and then repaired after periods of 3, 6, 9, 12, and 18 months. Four months after nerve repair, the sciatic nerve was again cut and the proximal nerve stump was injected with horseradish peroxidase to label the spinal cord neurons of the sciatic nerve nucleus. Both acetyl-L-carnitine-treated and untreated rats showed a tendency to have an increased number of horseradish peroxidase-labelled neurons with respect to intact rats of correspondent ages.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcarnitine↗
PubMed1989

Effects of tetrahydrolipstatin, a lipase inhibitor, on absorption of fat from the intestine of the rat.

Tetrahydrolipstatin (THL) derived by hydrogenation from lipstatin, a lipase inhibitor produced by Streptomyces toxytricini, has been shown to inhibit in vitro the activity of all three lipases secreted to the gastro-intestinal tract; gastric lipase, pancreatic lipase and carboxylester lipase (cholesterol ester hydrolase). The effects of THL on intestinal absorption of fat (transport to the thoracic duct chyle) has now been investigated after intraduodenal infusion in a rat model. Absorption of label from oleic acid when administered with monoolein in micellar bile salt solution was not affected by THL in concentrations up to 10(-4) M calculated on the volume of the aqueous phase. Absorption of free cholesterol in micellar bile salt solution of the lipolytic products of triolein; oleic acid and monoolein, is not significantly affected at a concentration of THL of 10(-4) M. Absorption of cholesterol from cholesteryl oleate under the same conditions is almost completely inhibited. The results indicate that absorption of free cholesterol is not dependent on the activity of pancreatic cholesterol ester hydrolase. The absorption of emulsified triolein was not significantly affected by 10(-5) M THL but decreased to around 30% of the controls by a concentration 10-times higher. There was no significant decrease of cholesterol absorption when administered in emulsified triolein while absorption of cholesteryl oleate was reduced at both concentrations of THL and almost completely at 10(-4) M. Radioactivity from [2-14C]THL when administered emulsified in triolein was recovered in urine, bile and thoracic duct lymph to 10-14, 8-13 and 1-3%, respectively, largely independent on dose administered. Label from [1"-14C] THL was recovered in the same amounts in lymph but much less in bile and urine indicating that the amino acid moiety has been split off early in the absorption process.

Animals↗
PubMed1989

The utility of cognitive coping strategies for altering pain perception: a meta-analysis.

The literature on the utility of cognitive coping strategies in pain control has been unclear because of 2 principal limitations: the lack of a validated classification system, and reliance on qualitative and quasi-statistical reviews. In this study, an empirically based multidimensional taxonomy was employed to categorize the variety of cognitive coping strategies into 6 major classes: external focus of attention, neutral imaginings, pleasant imaginings, dramatized coping, rhythmic cognitive activity and pain acknowledging. Meta-analytic techniques were introduced to evaluate the overall efficacy of cognitive strategies (in comparison to no-treatment controls), the relative efficacy of these strategies (how the different groups of strategies compare with one another), and the substantive efficacy of such strategies (how cognitive strategies fare against placebo/expectancy conditions). Results revealed that, in general, cognitive coping strategies are more effective in alleviating pain as compared to either no-treatment or expectancy controls. Each individual class of strategies significantly attenuates pain although the imagery methods are the most effective whereas pain acknowledging is the least effective. Positive expectancy is no better than no treatment. These findings stand in contrast with previous reviews that have not assigned prime importance to imagery or for that matter have not shown cognitive strategies to be particularly effective. Results are discussed with reference to attentional models and methodological issues.

Adaptation, Psychological↗
PubMed1989

Effects of L-carnitine, L-acetylcarnitine and gangliosides on the regeneration of the transected sciatic nerve in rats.

Three pharmacological agents, L-carnitine, L-acetylcarnitine and gangliosides, were tested for their ability to enhance the regeneration of the rat sciatic nerve following transection and microsurgical repair. The drugs were administered intraperitoneally at the dose of 50 mg/kg/d for 28 and 56 d postoperatively. At the end of treatment, the motor function recovery of the peroneal component of the sciatic nerve was assessed and the regenerated nerves were analysed morphometrically on histological semi-thin sections. Also, the reinnervated extensor digitorum longus (EDL) muscles were studied histochemically using the adenosine-triphosphatase (ATP-ase) technique 56 d after surgery. Motor function assessment at 56 d after nerve repair revealed that L-acetylcarnitine-treated animals recovered a clinical grade significantly higher (p less than 0.05) than the control animals. Twenty-eight days after nerve repair, the number of myelinated fibres was significantly higher (p less than 0.05) in L-acetylcarnitine and ganglioside-treated animals than in control animals. However, 56 d after nerve repair the number of regenerated fibres in all the drug-treated groups was not significantly different from that of the control group. The EDL muscles of the drug-treated animals did not show significant differences from those of control animals with respect to fibre composition and fibre diameter although the L-acetylcarnitine-treated animals exhibited a significantly lower (p less than 0.05) degree of muscle atrophy than did the control animals. The results of the present work seem to indicate that L-acetylcarnitine and to a lesser extent gangliosides exert some favourable effect on the regeneration of the transected sciatic nerve in rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcarnitine↗
PubMed1989

Mediastinal, left, and right atrial pressure variations with different modes of mechanical and spontaneous ventilation.

Variations in mediastinal, left, and right atrial pressures (MedP, LAP, RAP, respectively) were measured by means of catheters and tubes positioned in ten patients with nonvalvular cardiac surgery. For each pressure, a maximum, minimum, and mean value was determined in relation to its oscillations during the respiratory cycle. Thus, we compared the variations in MedP, LAP, and RAP in controlled mechanical ventilation (CMV), CMV with 5 cm H2O PEEP, synchronous intermittent mandatory ventilation (SIMV), SIMV with 5 cm H2O PEEP, continuous positive airway pressure (CPAP), and spontaneous respiration (SR). We built an experimental model to compare the measurements obtained by air-filled tubes inserted at surgery with those obtained by esophageal balloons filled with water. The maximum MedP did not vary significantly in these patients except when SIMV and SR were compared; however, the minimum MedP diminished significantly (p less than .001) in SIMV, SIMV-PEEP, CPAP, and SR, with negative inspiratory values reaching significant proportions. The mean values of MedP, LAP, and RAP showed a similar tendency although to a lesser degree. The experimental model revealed a strong linear relation between the values obtained with air-filled tubes and those obtained with water-filled esophageal balloons (r = .99, p less than .001). These results suggest that the mean values of MedP, LAP, and RAP do not reflect the dynamic variations in ventricular filling pressure accurately, nor the important negative inspiratory peaks that appear in different types of ventilation using spontaneous cycles with and without PEEP. These inspiratory peaks can overload the left ventricle by hydrostatic gradients, and lead to pulmonary edema in susceptible patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Transplant of a pediculate segment of vas deferens. Experimental study.

A new surgical technique has been used on white New Zealand rabbits. A segment of vas deferens was transplanted to the contralateral deferens with the intention of improving treatment for certain cases of infertility caused by obstruction. Evaluation of the technique was carried out by repeated seminograms, deferentovesiculography and histological studies of the transplanted deferens segment and the corresponding testicle. The viability of this surgical technique has been shown using the rabbit as an experimental specimen.

Animals↗