Search PubMed⌕ Search

Biomedical subjects

E Gonzalez

Publications and source records attributed to E Gonzalez.

At least 91 records · Page 5Linked to original sources
PubMed1996

Elucidation of intestinal transport results as a function of age.

Duodenal, jejunal, ileal and caecal morphometrics were determined in chickens from hatching to the age of 15 weeks. The ratios of fresh weight/surface area and dry weight/surface area showed age-dependent changes in all the intestinal segments studied. The percentage of mucosa in each segment was also age-dependent in the first three weeks of life with a higher participation in the proximal intestine. Transport of 3-oxy-methyl-D-glucose was determined in the jejunum and ileum using a perfusion technique in vivo and expressed as a function of fresh weight, dry weight and surface area. The age-dependent differences observed in weight and mucosa composition of the intestine make it difficult to interpret the results of transport capacity during development. The optimum expression of results in the field of intestinal absorption may be the surface area, since it involves the smallest errors.

3-O-Methylglucose↗
PubMed1995

Angiotensinogen-like epitopes are present in the CNS of Aplysia california and co-localize with urotensin I- and urotensin II-like immunoreactivities in the cerebral ganglia.

Immunohistochemistry was used to demonstrate urotensin I (UI), urotensin II (UII), and angiotensinogen (Ao)-like immunoreactivities (ir) in the CNS of Aplysia californica. The fish UI is a 41 amino acid peptide that has 50% identity with mammalian corticotropin-releasing factor (CRF). Identity also exists between UI and angiotensinogen in a tetrapeptide at the N-terminus. Ao-ir neurones were found in the F cluster of the Aplysia cerebral ganglia. Beaded Ao-ir fibres were seen in the neuropile and commissure of the cerebral, pleural and pedal ganglia. Ao neurosecretory material was also seen in the perineural region of the proximal supralabial nerve. Previously we have demonstrated UI and UII immunoreactivities were present in the CNS of Aplysia. A comparison of adjacent sections of the cerebral ganglia immunostained sequentially for UI, UII and Ao revealed that all three immunoreactivities co-existed in the same cells of the F cluster of the cerebral ganglia. Liquid-phase immunoabsorption of the Ao antiserum revealed that porcine or human angiotensinogen but not UI or UII were able to quench Ao immunostaining. Conversely UI and UII staining were quenched by white sucker (Catatomus commersoni) UI and goby (Gillichtys mirabilis) UII, respectively, but they were not modified by angiotensinogen. These results suggest that UI-, UII-, and Ao-like peptides might co-exist as separate entities in the cerebral ganglia of Aplysia californica where they can act in an integrated and/or independent modulatory way.

Angiotensinogen↗
PubMed1995

Severe anemia as the presenting manifestation of giant cell arteritis.

Giant cell (temporal, cranial) arteritis (GCA) is usually confirmed in patients presenting with classic features. Those who present with atypical features often undergo prolonged evaluations until a diagnosis is established. Severe anemia as an initial manifestation of GCA has rarely been described. We describe herein 2 patients with biopsy-proven GCA who presented with severe anemia and significant weight loss, which corrected after corticosteroid therapy.

Aged↗
PubMed1995

The role of nitric oxide in the metabolism of labeled glucose in isolated rat uterus. Influence of 17 beta-estradiol.

The influence of nitric oxide (NO) on the production of 14CO2 from labeled glucose in uteri isolated from ovariectomized-estrogenized rats was studied. Nitroprusside, an NO donor (NP), 200 microM increased the formation of labeled CO2 from [U-14C]glucose. This effect was blunted by hemoglobin (Hb) 20 micrograms/mL, an NO scavenger. The addition of N-monomethyl arginine (NMMA), an inhibitor of NO synthase decreased the stimulatory action of NP at 400 mM. Incubation of uterine strips in the presence of NP plus acetylsalicylic acid (ASA) 10(-4) M (a cyclooxygenase inhibitor), inhibited the stimulatory action of NP on glucose metabolism. PGE2 (10(-7) M) added to the incubation medium containing NP and ASA reversed the effect of the inhibitor. Neither NP nor Hb nor NMMA modified the 14CO2 production from labeled glucose in uterine strips from ovariectomized rats. The addition of NP to the incubating medium increased PGE accumulation by uterine strips from rats treated with estradiol, but not in ovariectomized animals. These results suggest that NO exerts a positive influence on glucose metabolism and PGE synthesis in isolated rat uteri from estrogenized animals.

Animals↗
PubMed1995

Umbilical venous catheters: evaluation of radiographs to determine position and associated complications of malpositioned umbilical venous catheters.

To evaluate the ability of radiography to detect malpositioned umbilical venous catheters in the left atrium and to determine the frequency of associated complications, we retrospectively compared radiographs and echocardiograms of 31 infants who had malpositioned catheters in the left atrium by echocardiography (cases) and 31 infants who had properly positioned catheters (controls). The case and control infants were of similar gestational age and birthweight (gestational age, 32 +/- 5 weeks; birthweight, 1672 +/- 899 g for cases; gestational age, 31 +/- 5 weeks; birthweight, 1666 +/- 958 g for controls). Malposition was defined as the catheter tip above the seventh thoracic vertebra by radiography. Radiography had sensitivity of 45%, specificity of 87%, positive predictive value of 77%, negative predictive value of 61%, accuracy of 66%, and prevalence of 50%. Thrombus formation in the heart was detected in 8 of 31 (26%) of cases and in 1 of 31 (3%) of controls (p = 0.03). The incidence of complications, such as necrotizing enterocolitis, culture-positive sepsis, total number of sepsis cases, thrombocytopenia, embolism to extremities, and hematuria were similar in both groups (difference not significant). These results suggest that radiography is unreliable in determining incorrect catheter placement. Catheters malpositioned in the left atrium were associated with thrombus formation. There was no significant increase in systemic complications in the infants with a malpositioned catheter.

Case-Control Studies↗
PubMed1995

Head and neck squamous cell carcinoma metastatic to the orbital apex.

Primary squamous cell carcinoma of the head and neck most commonly metastasizes to the lymph nodes, lung, bone, and liver. Many other rare sites of metastatic disease have been reported. To date, metastatic squamous cell carcinoma of the head and neck to the orbital apex has not been described. Presented are two cases, one tonsil and one parotid primary with metastatic disease to the orbital apex. Many tumors have been found to metastasize to the eye and orbit, but head and neck neoplasms are rarely reported. A review of the literature is presented in addition to the detailed case reports with their radiologic findings and clinical course. Surgical resection followed by postoperative radiotherapy appears the treatment of choice at this time.

Case Reports↗
PubMed1995

Application of a colorimetric method to the determination of the protein content of commercial foods, mixed human diets and nitrogen losses in infantile diarrhoea.

Recently we reported on the application of a method for protein determination which measures nitrogen in Kjeldahl digests colorimetrically. This procedure has the advantage of eliminating the distillation and titration steps of the Kjeldahl method and it is ideal for nutritional studies, since many samples can be run in a single day. Accordingly, the purpose of the present report was to extend the application of this method to the determination of the protein content of commercially available foods such as dairy products, dry cereals or cereal based products and legumes and also to evaluate this method in the determination of the protein content of the mixtures of cooked foods served during lunch at the cafeteria of the Universidad Simón Bolívar, Caracas. In both cases the results of the colorimetric nitrogen agreed very well with those obtained by the macro Kjeldahl, indicating that the colorimetric method may be used in monitoring the protein content of commercial foods and in evaluating the protein offered in institutional food services. Finally, to further demonstrate the value of this method in clinical trials, we used it to monitor the daily nitrogen intake and nitrogen losses in 43 male young children with acute diarrhoea, and 15 with persistent diarrhoea fed liquid formulae, and showed that protein digestibility and retention were higher in persistent than in acute diarrhoea. The severity of acute diarrhoea affected negatively (r = -0.62) the percentage of protein absorbed, whereas the protein absorbed (r = 0.70) and retained (r = 0.55) correlated positively with protein consumption.(ABSTRACT TRUNCATED AT 250 WORDS)

Colorimetry↗
PubMed1994

Capillary zone electrophoresis for the rapid screening of banned drugs in sport.

Capillary zone electrophoresis was used to analyze some drugs illegally used in sports. The spectroscopic characteristics and electrophoresis migration parameters of diuretics, narcotics-analgesics and beta-blockers were established. Analytical figures of merit including parameters on the precision of migration and limits of detection are discussed. Results for the separation of drugs of different doping families are discussed. An analysis of urine from a patient receiving daily doses of atenolol is presented.

Adrenergic beta-Antagonists↗
PubMed1994

Dissociative states induced by relaxation training in a PTSD combat veteran: failure to identify trigger mechanisms.

PTSD is often treated with anxiety management techniques, including relaxation training. A case report is presented which describes a PTSD combat veteran who experienced dissociative states induced by relaxation training. Hypnotherapy subsequently identified traumatic memories which were recalled during relaxation training but triggering mechanisms for the recall of these traumatic memories were not identified.

Adaptation, Psychological↗
PubMed1994

An animal model of necrotizing enterocolitis induced by infant formula and ischemia in developing piglets.

BACKGROUND/AIMS: The lipid component of piglet formula (0.5% fat) causes increased mucosal permeability in 1-day-old piglets after ischemia/reperfusion. The present study examined if luminal exposure to infant formulas (3.5% fat) and ischemia/reperfusion result in an animal model of necrotizing enterocolitis and if injury is dependent on the formula fat composition. METHODS: Plasma-to-lumen clearance of 51Cr-ethylenediamine-tetraacetic acid was measured, and morphology was evaluated during luminal perfusion with preterm, term, and delipidated preterm cow milk-based infant formulas before and after ischemia/reperfusion in 1-day-old and 1-month-old piglet jejunoileum. In a separate set of experiments, a 1-2-cm segment of ileum was exteriorized and opened to expose the mucosal surface, and the villi were superfused with the above formulas (no ischemia). RESULTS: Before ischemia, clearances were markedly higher for intestinal loops perfused with preterm formula than for loops perfused with term and delipidated formulas in 1-day-old animals. After ischemia, clearances in loops perfused with preterm formula were significantly greater and grossly hemorrhagic and histologically necrotic compared with loops perfused with delipidated formula (minimal injury). Superfusion with preterm formula caused diffuse hyperemia and hemorrhage into intestinal villi. CONCLUSIONS: Luminal perfusion of 1-day-old piglet jejunoileum with predigested and bile acid-solubilized preterm infant formula, in combination with ischemia/reperfusion, produces an animal model of necrotizing enterocolitis, but only if the lipid fraction of the formula is present.

Animal Feed↗
PubMed1994

Differential apomucin expression in normal and neoplastic human gastrointestinal tissues.

BACKGROUND/AIMS: The cloning of genes encoding human mucins is the basis for the study of their normal tissue distribution and the alterations associated with cancer. The aim of this study was to determine the normal and tumor tissue expression of MUC1, MUC2, MUC5B, and MUC5C. METHODS: The reactivity of apomucin-specific antibodies with fresh normal and tumor tissues was analyzed using immunohistochemical techniques. RESULTS: Anti-MUC1 antibodies reacted with most glandular epithelia. Anti-MUC2 antibody was mainly reactive with intestinal goblet cells and cervical mucous cells. Anti-MUC5B was reactive with a wide range of epithelial tissues whereas anti-MUC5C was reactive with stomach, trachea, and endocervix. Double-labeling experiments showed coexpression of MUC1/MUC2 and MUC2/MUC5C in colonic tissue. Multiple apomucins were detected in colon cancers, but no relationship to histochemical mucus stains was observed. CONCLUSIONS: It is concluded that (1) each apomucin shows a distinct tissue expression pattern; (2) multiple apomucins are present in a single tissue and at the single cell level; and (3) altered apomucin expression takes place in pathological colonic tissue.

Amino Acid Sequence↗
PubMed1994

Effects of U46619 and of inhibitors of the synthesis of TXA2 on insulin action on the metabolism of labelled glucose in uteri isolated from ovariectomized-diabetic rats.

The production of 14CO2 from labelled glucose by isolated uterine strips from ovariectomized-diabetic rats has been studied. U46619, an analogue of TXA2 did not affect basal glucose metabolism; however, insulin-induced increment in CO2 production was completely blocked, both in ovariectomized (OVD) or ovariectomized-estrogenized (OVED) diabetic uterus. OKY064 as well as UK38485, both inhibitors of TXA2 synthesis, stimulated glucose metabolism (p < 0.05) similar to that of insulin in uterine tissue from OVD and OVED rats. Inhibition in the synthesis and release of TXB2 was detected (p < 0.01) by uterine radioconversion of 14C-arachidonic acid when adding OKY38485 to the incubation medium, and the production of other prostanoids such as 6-keto-PGF1 alpha, PGF2 alpha and PGE2 was enhanced. In summary, TXA2 inhibited insulin-induced glucose metabolism in diabetic animals.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1994

Alpha-adrenergic and 5-HT2-serotonergic effects of some beta-phenylethylamines on isolated rat thoracic aorta.

1. 2C-H [2-(2,5-dimethoxyphenyl)ethylamine] (pD2 = 6.74), TMPEA [2,(2,4,5-trimethoxyphenyl)ethylamine] (pD2 = 5.83), 2C-D [2-(2,5-dimethoxy-4-methylphenyl)ethylamine] (pD2 = 5.06), homoveratrylamine [DMPEA, 2-(4,5-dimethoxyphenyl)ethylamine] (pD2 = 4.46) and homopiperonylamine [MDPEA, 2-(3,4-methylenedioxyphenyl)ethylamine] (pD2 = 4.19), elicit concentration-dependent contraction of the isolated rat thoracic aorta. 2. At 9.9 x 10(-6) M, 2C-N [2-(2,5-dimethoxy-4-nitrophenyl)ethylamine] behaves as a competitive antagonist to serotonin in this preparation. 3. Considering previous results with the structurally related 2C-B [2-(4-bromo-2,5-dimethoxyphenyl)ethylamine], weak or partial agonistic activity or antagonism of aortic contraction appears to be related to psychedelic properties reported in humans for phenylethylamines.

Animals↗
PubMed1994

Outcome of insulin-treated diabetics receiving epinephrine during cardiac arrest.

The purpose of this study was to determine the effects of epinephrine in insulin-treated diabetics (DM) compared with nondiabetic (ND) controls during cardiopulmonary resuscitation (CPR). A retrospective analysis from a multicenter study of out-of-hospital cardiac arrest included 62 DM and 1,151 ND. Outcome parameters included return of spontaneous circulation (ROSC), blood pressure (BP), emergency department admissions (EDA), hospital admissions (HA), and hospital discharge (DC). In DM treated with standard-dose epinephrine (SDE), there were trends toward improved ROSC, BP, EDA, and HA compared with ND. DC was not different. With high-dose epinephrine (HDE) these outcomes were not different. Comparison of the outcomes of DM given SDE versus those given HDE were not different. However, none of the DM given HDE (n = 24) were discharged from the hospital. These results suggest that DM may have improved resuscitation rates with SDE and may be adversely affected with HDE. Larger prospective studies are needed to confirm these findings.

Aged↗
PubMed1994

Tuberculosis in the Republic of Cuba: its possible elimination.

SETTING: Tuberculosis elimination is a priority in most developed countries, although the AIDS epidemic and drug resistance are a handicap in some of them. Tuberculosis is an even greater problem in developing countries. OBJECTIVE: To evaluate the epidemiological situation in Cuba, the trend of new cases reported for 1979-91 by clinical category and age group is described. DESIGN: A simple regression model was fitted to the time series data on 'new case' rates taken from the national surveillance system. The annual variation percentage was estimated. RESULTS: From 1979-91 tuberculosis decreased by 59.5% (from 11.6-4.7 per 10(5) persons per year). This decline occurred in all age groups; 60% of new cases in 1991 were aged 45 years and over, of which 30% were aged 65 and over. Drug resistance of Mycobacterium tuberculosis strains (2.49% in 1989) remains uncommon and HIV infection (0.009% in 1991) is rare in the general population. CONCLUSIONS: The continuing steady decline of the number of new cases reported, in addition to the favorable trend of drug resistance and the low rate of HIV infection in the general population so far seem to indicate the real possibility of maintaining the effectiveness of the National Programme for Tuberculosis Control in the future, making it reasonable to formulate new strategies for the elimination of the disease.

Adolescent↗
PubMed1994

Cell calcium concentration in glomerular afferent and efferent arterioles under the action of noradrenaline and angiotensin II.

The glomerular arterioles in the juxtaglomerular apparatus seem to function as effectors of the tubuloglomerular feedback mechanism. In this mechanism increased delivery of fluid to the distal nephron activates the macula densa cells through transport via an Na-2Cl-K cotransporter. This activation may lead to vasoconstriction of the afferent arteriole. Furthermore, vasoactive substances seem to affect both afferent and efferent arterioles. There are morphological differences along the afferent arteriole, some parts containing epithelioid cells with renin granules and others regular smooth muscle cells. The aim of the present experiments was to determine whether noradrenaline (10(-6) M) and angiotensin II (10(-6) M) had differential effects on the cell calcium concentration [Ca2+]i and on contraction in isolated perfused afferent and efferent arterioles and in the mesangial region. [Ca2+]i was measured with fura-2, an intensified videocamera and a digital imaging system. From the proximal to the distal part of the arteriole [Ca2+]i increased from about 100 to 250 nM. A [Ca2+]i increase and a contraction were caused by noradrenaline alone in the proximal part of the afferent arteriole and by angiotensin II alone in the distal part of this arteriole. In the mesangial region there was a high basal [Ca2+]i but no response to the vasoactive substances. In the efferent arteriole, application of both noradrenaline and angiotensin II led to an increase in [Ca2+]i and a contraction. The present experiments indicate that the two vasoactive substances tested act in a similar fashion along the whole length of the efferent arteriole, while in the afferent arteriole their actions are not equally distributed.

Angiotensin II↗