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Biomedical subjects

E Perez

Publications and source records attributed to E Perez.

At least 91 records · Page 5Linked to original sources
PubMed1990

Relationship between cAMP concentration in anterior hypothalamic-preoptic region and the ultradian wake-sleep cycle.

In the rat anterior hypothalamic-preoptic region adenosine 3':5'-cyclic monophosphate concentration changes during the ultradian wake-sleep cycle. The administration of DL-propranolol and the exposure to low ambient temperature decreased the nucleotide concentration and also modified the wake-sleep cycle. This suggests that in this region a biochemical correlation exists with different functional states.

Activity Cycles↗
PubMed1990

[Castleman's disease (giant lymph node hyperplasia): clinical, biological and developing polymorphism. Apropos of 4 cases].

Four cases of plasma cell type Castleman's disease (CD) are described. Two patients had localized forms (one mediastinal and the other mesenteric) and presented systemic manifestations associated with hypergammaglobulinemia and severe anemia. In both cases, the lesions were revealed by computerized tomography scans and cures were obtained by the complete surgical removal of the masses, which led to the rapid disappearance of the systemic manifestations. The other 2 patients had the multicentric form of CD and presented more extensive clinical and biological symptoms. One of these developed severe peripheral neuropathy and endocrine anomalies during the late phase of his disease, which led us to discuss the relationship between multicentric CD and the POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein, skin change) syndrome first described in Japan. Three of our patients presented with hypochromic microcytic anemia too severe to be explained by an inflammatory syndrome alone, and was likely due to several mechanisms. The etiology of CD remains unknown. The histological characteristics of angiofollicular lymph node hyperplasia are among the most important criteria for the diagnosis of localized and multicentric forms of CD, which can easily be made on a lymph node biopsy. However, it must be noted that this lesion can also be observed (but only rarely) in HIV (human immunodeficiency virus) - infected patients. The localized form is always considered to be benign, but, to date, there is no formal argument definitively supporting the malignancy of the multicentric one, in spite of its clinical similarity to a lymphoproliferative syndrome.

Adult↗
PubMed1989

[Nosocomial infections caused by Acinetobacter. Epidemiology and therapeutic difficulties].

Nosocomial infections due to Acinetobacter calcoaceticus are not easy to treat particularly in intensive-care and surgical units. Our study included 33 cases of nosocomial infections which developed during 1987 in the surgical intensive care unit and in the urology department. Acinetobacter was isolated from various types of nosocomial infections: urinary tract infections (43 per cent); septicaemia (15 per cent); surgical infections (27 per cent) and respiratory tract infections (15 per cent). Forty eight per cent of the patients received an antibiotic therapy and 52 per cent had no specific treatment. The following beta-lactam antibiotics were studied: ticarcilline, mezlocilline, cefotaxime and ceftazidime, and 83 per cent of the strains were TICRMEZRCTXR (phenotype IV). All the strains except one were imipenem susceptible. The study of aminoglycoside resistance in Acinetobacter showed that 91 per cent of the strains were gentamicin resistant (GENR); 25.5 per cent were gentamicin, and amikacin resistant and tobramycin susceptible (GENR AMKR TOBS, phenotype IV), and 45 per cent were GENR TOBR AMKR (phenotype V). Acinetobacter strains were resistant and 63 per cent pefloxacin resistant. Co-trimoxazole resistant strains represented 65 per cent of the strains. Should major antibiotics be used to treat nosocomial infections due to multiresistant Acinetobacter strains? Are prophylaxis, aseptic and surgical procedures sufficient to control these infections?

Acinetobacter Infections↗
PubMed1989

Cross-reactivity between penicillins and cephalosporins: clinical and immunologic studies.

Nineteen well-characterized penicillin-allergic patients were investigated for their sensitivity to cephalosporins containing potentially cross-reactive side chains. All patients were administered cephamandole parenterally and, if this was tolerated, a course of oral cephaloridine was administered. Only two patients responded to the cephamandole; none of the remaining patients reacted to cephaloridine. Benzylpenicilloyl RAST-inhibition studies with sera from three subjects who had not reacted to the cephalosporins demonstrated that cephamandole linked to proteins was capable of recognizing benzylpenicilloyl-specific IgE antibody. It is concluded that consideration of side chain structures can help to predict possible cross-reactions between penicillins and cephalosporins, but carefully controlled challenge tests are advisable before penicillin-allergic patients are treated with cephalosporins. In relation to cross-reacting potential, in vitro experimental studies are difficult to interpret and may in some circumstances overestimate the risk.

Adult↗
PubMed1989

Comparative study of brain morphology in ants.

Brain morphology, with special attention to the three dimensional form of the corpora pedunculata, was studied in thirteen species of ants, representing four subfamilies of Formicidae. The results can be summarized as follows. (1) The neural systems processing optic and olfactory information differ in the evolutionary history among the studied taxa. A positive correlation can be demonstrated in the phylogenetic history of the corpora pedunculata, central body, cerebral bridge and olfactory lobe, but not the optic lobe. Ant species with very large eyes and thus, probably, highly developed vision, show gigantic optic lobes, with no exaggeration of any other brain structure. (2) More social species have more complex chemical communication systems and better developed corpora pedunculata (more surface in foldings of the calyces) and olfactory lobes; however, this tendency seems to reverse in highly social species with a sophisticated polymorphic caste system: individuals of these species are generally less developed neurally. (3) There are differences between the form of the internal and external calyces of the corpora pedunculata, and these differences are proportionately more pronounced in species with complex social organization. (4) Individuals from different worker castes of the same species differ in their brain morphology, but each species shows a different pattern of variation among their castes. (5) Brain structure shows characteristic marks due to the different phylogenetic developments in the taxa studied. For example the trends in brain volume-body size ratio are different for the various subfamilies, suggesting a divergent phylogenetic history.

Animals↗
PubMed1989

Bulimia: independence of antibulimic and antidepressant properties of desipramine.

The purpose of this study was to identify variables useful for predicting a positive response to the tricyclic antidepressant desipramine, amongst bulimic subjects. Using a randomized double-blind cross-over design, 24 normal weight bulimics completed a 15-week protocol in which they received either desipramine (150 mg/day) for six weeks, no drug for three weeks, followed by placebo for six weeks, or the reverse sequence. At weeks 0, 2, 4, 6, 9, 11, 13, and 15, each subject was assessed using the EDI, SCL-90, POMS and binge records. The DST, Diagnostic Interview Schedule (DIS), and a personal and family medical-psychiatric history questionnaire were administered at initial assessment, while plasma desipramine levels were obtained at weeks 4 and 13. Responders were defined in terms of both binge frequency reduction, and decrease in depressive symptoms. In the sample of 24 subjects, desipramine was significantly more effective than placebo in reducing the frequency of weekly binging and vomiting, as well as causing a reduction in the fatigue scale of the POMS. No significant effect of the drug was obtained on the EDI or the SCL-90. In terms of reduction in binge frequency, seven responders were identified; another seven were found to be borderline responders, while 10 were labeled as non-responders. The three groups did not differ in terms of their initial scores on the SCL-90, POMS, DST, DIS results, or psychological subscales of the EDI. However, responders were found to have lower EDI bulimia subscale scores, but a higher frequency of purging episodes than were non-responders. Eight patients were identified as borderline responders with respect to depressive symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Angioedema and IgE antibodies to aspirin: a case report.

We present a case of a patient who developed two episodes of angioedema after taking acetylsalicylic acid orally. Specific IgE antibodies to acetylsalicylic human serum albumin (ASA-HSA) were found. A control group of 37 patients with aspirin intolerance was studied and evidence of specific IgE antibodies was not found. The follow-up of this case shows that in a short period of time the level of specific IgE antibody decreases to undetectable levels similar to the negative control population.

Angioedema↗
PubMed1989

Accidental terfenadine ingestion in children.

Terfenadine is a newly marketed non-sedating antihistamine. It binds strongly with peripheral H-1 receptors and only weakly with muscarinic, alpha and beta-adrenergic receptors. There is limited information about ingestion by children 1-5 years old and no reports in the literature of accidental ingestion. We performed a 1-year retrospective study at the DVRPCC and NJPIES. Twenty-eight cases of accidental ingestions of terfenadine by children aged 1-5 yrs were identified; 27 cases were treated at home and 1 treated in a hospital. Two cases (120 mg and 300 mg) received ipecac at home and were followed by telephone with 1.4 and 24 hr callbacks. No symptoms were reported. In 1 case (180 mg) ipecac was advised but the mother refused to give it. No symptoms were reported on followup. One case (2 yr, 900mg) was referred to a hospital and arrived asymptomatic 2 hr postingestion. The child received activated charcoal and sorbitol, remained asymptomatic and was discharged 6 hr postingestion. The remaining 24 cases (60 mg-120 mg) were treated at home with observation alone. Twenty-one of these cases reported no symptoms on followup. Three cases were lost to followup. Evidence suggests that accidental ingestions of small doses of terfenadine (60 mg-120 mg) in children will not produce toxicity. Larger studies may be needed to verify these findings.

Accidents, Home↗
PubMed1989

The effect of propranolol on cAMP concentration in the rat preoptic region during the wake-sleep cycle.

In control conditions preoptic cAMP concentration during wakefulness was significantly higher than during synchronized sleep. No differences in nucleotide concentration were observed in the cerebral cortex. Propranolol decreases brain cAMP concentration. This change was associated with the suppression of the difference observed between wakefulness and synchronized sleep in the preoptic region.

Activity Cycles↗
PubMed1989

[Deep interscapular temperature and thermogenesis of brown fat during sleep].

Deep interscapular temperature measured just below the brown fat lobes was studied in rats during sleep at two ambient temperatures (24 degrees C and 4 degrees C) before and after adaptation (9 days) to cold (4 degrees C). The results show that in the cold ambient deep interscapular temperature decreases during desynchronized sleep independently of adaptation. Such change in temperature is probably the result of the depression in sympathetic vasoconstrictor influences on heat exchangers producing blood and brown fat cooling in sequence during this stage of sleep.

Adipose Tissue, Brown↗
PubMed1989

[Hypothalamic temperature and thermogenesis of brown fat during desynchronized sleep in rats].

The relationship between hypothalamic temperature and deep interscapular temperature measured just below the brown fat lobes has been studied during desynchronized sleep at two ambient temperatures (24 degrees C and 4 degrees C) before and after adaptation (9 days) to cold (4 degrees C). The results show that the increase in hypothalamic temperature during this stage of sleep occurs independently of a transfer of heat from interscapular brown fat.

Adipose Tissue, Brown↗
PubMed1988

Oestradiol changes the dielectric structure of bilayer membranes.

The addition of the hormone Oestradiol to Phosphatidylcholine-Cholesterol membrane changes the frequency dependence of the membrane impedance. It increases severalfold the electrical admittance of the polar regions and consequently provides a conducting shunt from the hydrocarbon region to the aqueous phase.

Cholesterol↗
PubMed1988

Anaphylaxis to amoxycillin but good tolerance for benzyl penicillin. In vivo and in vitro studies of specific IgE antibodies.

Three patients are reported on who suffered anaphylactic reactions after amoxycillin (AX) treatment and challenge but tolerated benzylpenicillin (BP) parenterally and orally. Two of the three patients had positive skin tests and RAST to AX reagents but negative responses to benzyl penicilloyl (BPO) specific skin tests and RAST and the minor determinant mixture (MDM) skin test reagent. The third case was negative to all skin tests and RAST. RAST and RAST inhibition on the two positive sera suggest that the response is related to the acyl side chain of AX.

Adult↗
PubMed1988

Treatment of bulimia with desipramine: a double-blind crossover study.

The purpose of this study was to evaluate the effect of desipramine, a tricyclic antidepressant with relatively specific noradrenergic effects, on bulimic behaviour, eating attitudes, and mood. Using a double-blind crossover design, 47 normal weight bulimics were randomly assigned to receive either desipramine (150 mg/day) for six weeks, no drug for three weeks, followed by placebo for six weeks, or the reverse sequence. At weeks 0, 2, 4, 6, 9, 11, 13, and 15, each subject was assessed using the EDI, SCL-90, POMS and binge records. Plasma desipramine levels were obtained at weeks 4 and 13. Twenty-four subjects completed the entire fifteen week protocol, while 23 dropped out. Desipramine was significantly more effective than placebo in reducing the frequency of weekly binding, weekly vomiting, and the fatigue scale of the POMS. No significant effect of the drug was obtained on the EDI or the SCL-90. The clinical effect was modest. Desipramine's antibulimic effects were not associated with an alleviation of depressive symptoms.

Adult↗
PubMed1988

[The effect of preventative carazolol treatment on stress reactions in boars during semen collection].

The effect of the beta adrenoceptor blocking agent carazolol on heart and circulatory system, on blood values of the acid-base-equilibrium and on plasma enzymes such as creatine-kinase (CK) and aspartate-amino-transferase (ASAT) was investigated in four clinical healthy boars of the German Landrace and four boars of the Piétrain race before, during and after ejaculation at the phantom. The heart rate during semen collection increased less with treatment than it did without it. The relative diastolic time during exertion was prolonged by carazolol in those boars, which also without pharmacological influence had a very short relative diastolic time. By carazolol injection the systolic blood pressure could be decreased most in those boars, which without treatment had the highest rise of systolic blood pressure during semen collection. Furthermore it was shown, that the highest lactate values, which were found in some boars of the Piétrain race, were reduced most by the influence of carazolol. The blood values of the acid-base-equilibrium were highly negative correlated with the lactate values and changed according to them. The enzyme activities (CK and ASAT) 24 h after semen collection were not influenced by carazolol. Individual differences from boar to boar were evident in all examined parameters and were independent of the effects of carazolol treatment.

Acid-Base Equilibrium↗
PubMed1988

[Stress reaction in boars of the German Landrace and Piétrain breeds during semen collection from the phantom].

The effect of the semen collection procedure at the phantom on heart and circulatory system, on blood values of the acid-base-equilibrium and on plasma enzyme values was investigated in four boars of the German Landrace and four boars of the Piétrain race. In most of the boars tachycardia (heart rate above 239/min), an increase of plasma lactate concentration (above 10.0 mmol/l) and of plasma creatine kinase (CK) concentration (plasma CK above 1,000 U/l) were the consequences of the exertion by semen collection. The extent of the exertional reactions on heart and vasculatory parameters strongly depended on the individual disposition while in most of the metabolic blood values the two different races varied evidently. The values of CK 24 hours after semen collection were related to the plasma lactate concentration as well as to the heart rate during semen collection.

Acid-Base Equilibrium↗
PubMed1987

Collagen at interfaces. II: Competitive adsorption of collagen against albumin and fibrinogen.

Adsorption of chemically radiolabeled [14C] collagen from binary mixtures with albumin or fibrinogen was studied on the solution/air and solution/polyethylene interfaces and revealed the preferential adsorption of albumin. This phenomenon is confirmed by the data of surface tension measurements of single protein, collagen-albumin, and collagen-fibrinogen solutions. Desorption experiments clearly show that more irreversibly adsorbed collagen was found on polyethylene surfaces when adsorption was performed from collagen-fibrinogen than from collagen-albumin solutions. The combined adsorption-desorption and the surface tension data show that competitive adsorption of collagen at the hydrophobic surfaces is strongly influenced by the surface tension properties of the proteins in solution.

Adsorption↗