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Biomedical subjects

M Ferrer

Publications and source records attributed to M Ferrer.

At least 181 records · Page 10Linked to original sources
PubMed1978

Loss of immunological and biological activity of insulin with a human muscle extract.

The isolation of a human muscle extract that degrades insulin to products incapable of any immunological or biological activity is reported. The extract Km value for human insulin is 0.79, and 1.43 for porcine proinsulin. It does not degrade Human Growth Hormone at the concentrations tested, it is inactivated by N-ethyl-maleimide, Trasylol, and heat, and it does not require glutathione for its action. Human muscle, therefore can contain an enzyme similar to "insulin-specific-protease" present in rat muscle.

Adipose Tissue↗
PubMedDate not supplied

A biochemical study of fasting, subfeeding, and recovery processes in yellow-legged gulls.

An investigation of the effects of fasting, subfeeding, and refeeding on plasma biochemistry was carried out on 22 captive yellow-legged gulls Larus cachinnans Pallas. These birds showed the same fasting endurance model described in other species, but with an important decrease in glucose plasma concentration and very great differences between individuals when reaching the deterioration limit, suggesting a moderate physiological adaptation to long periods of fasting. A different model was proposed in subfed gulls in relation to fasted gulls, based on lipid and protein use, which could be reflected by changes in nitrogen wastes and triglyceride levels in this experiment. Thus, the subfed gulls might use protein directly from the diet as an energy source, thereby reducing the use of fat stores. The gulls quickly recovered body mass during the refeeding period, but while some plasma substances quickly reached their initial values, others showed many changes before the end of the experiment, which could reflect a process of metabolic restabilization. These results contribute to a better knowledge of fasting, subfeeding, and refeeding processes in birds and can be added to a recent study about fasting in gulls.

Animals↗
PubMedDate not supplied

Age-related changes of plasma alkaline phosphatase and inorganic phosphorus, and late ossification of the cranial roof in the Spanish imperial eagle (Aquila adalberti C. L. Brehm, 1861).

Plasma alkaline phosphatase and inorganic phosphorus levels were determined for 52 nestling Spanish imperial eagles from two wild populations and 22 captive adults and subadults (10 adults and 12 subadults). The exact age was known for all birds. Mean alkaline phosphatase and inorganic phosphorus were higher in chicks than in the captive adults and subadults. Sex differences were not observed, and nestlings from different populations showed similar values. No significant regression described the relationship between age and alkaline phosphatase or inorganic phosphorus throughout the nestling period. However, alkaline phosphatase and inorganic phosphorus decreased significantly throughout the subadult period, with age explaining 98.2% and 50.5% of the variation in alkaline phosphatase and inorganic phosphorus levels, respectively. Non-fully-ossified zones were measured in frontal bones of another 12 subadult eagles that died at known ages. Ossification increased throughout the subadult period and was significantly correlated with expected levels of alkaline phosphatase or inorganic phosphorus (i.e., values predicted from the regression equations derived from the first analysis). Minimum alkaline phosphatase levels and full ossification of the cranial roof coincided with puberty onset. We conclude that, in subadult Spanish imperial eagles, decreasing alkaline phosphatase and inorganic phosphorus values are related to the ossification of frontal bones, although a contribution of other unknown processes of late ossification cannot be excluded, and alkaline phosphatase (but not inorganic phosphorus) may be a useful parameter for age-predicting purposes.

Aging↗
PubMedDate not supplied

Care of the laparoscopic Nissen fundoplication patient.

Gastroesophageal reflux disease can usually be successfully managed with conservative medical treatment. Anti-reflux surgery is a safe alternative when treatment fails or patients desire a more definitive treatment option. Through a case study approach, this article describes the indications for surgery, the essentials of the authors' multi-disciplinary approach to care and the components of a well-designed education plan for a patient undergoing laparoscopic Nissen fundoplication. Although most patients do well after surgery, diligent nursing care is required before and after surgery to prevent or manage complications and ensure patients have a rapid recovery and successful outcome.

Fundoplication↗
PubMedDate not supplied

Heterogeneity of endothelium-dependent mechanisms in different rabbit arteries.

The possible endothelial factors involved in endothelium-dependent relaxations induced by acetylcholine (ACh) in aorta, mesenteric and femoral arteries of rabbit were analyzed. In thoracic aorta precontracted with noradrenaline, NG-nitro-L-arginine methyl ester (L-NAME) and methylene blue (MB), inhibitors of nitric oxide (NO) synthase and guanylate cyclase, practically abolished ACh relaxation. This relaxation was reduced by the Na+ pump inhibition with ouabain and K(+)-free solution, and by the blockade of Ca(2+)-dependent K+ channels with tetraethylammonium (TEA). Ouabain reduced the relaxation produced by the NO donor, sodium nitroprusside (SNP). In the mesenteric artery, L-NAME and MB produced a small reduction of ACh relaxation. However, ouabain, K(+)-free medium and TEA markedly decreased this relaxation. SNP induced a relaxation which was diminished by ouabain. In segments precontracted with high K+, ACh relaxation was abolished by L-NAME and MB. In femoral arteries, L-NAME and MB reduced ACh relaxation. The stimulated cGMP concentrations caused by ACh or SNP were less in the aorta than in mesenteric and femoral arteries. These results suggest that ACh relaxation is mediated: in aorta by endothelial NO which may hyperpolarize to some extent the smooth muscle cells through the sodium pump activation, in mesenteric artery by endothelium-derived hyperpolarizing factor and NO, the latter being clearly expressed in segments contracted with high K+, and in femoral artery essentially by endothelial NO release.

Acetylcholine↗
PubMedDate not supplied

Estrogen replacement increases beta-adrenoceptor-mediated relaxation of rat mesenteric arteries.

The purpose of the present study was to determine whether estrogen replacement in ovariectomized rats could modulate arterial diameter responses to beta-adrenoceptor activation. Under relaxed conditions (0.1 mM papaverine) there were no differences in the lumen diameter of isolated, pressurized (50 mm Hg) mesenteric arteries from nontreated (191.7 +/- 13.8 microns; n = 19) versus those from estrogen-treated (190.1 +/- 11 microns; n = 14) ovariectomized Sprague-Dawley rats. In arteries precontracted with noradrenaline (0.3-1 microM), isoprenaline (0.01-10 microM)-induced relaxation was significantly increased in arteries from ovariectomized estrogen-treated rats (52.4 +/- 2% of the maximal relaxation induced by 0.1 mM papaverine, vs. 33.3 +/- 6.5%; p < 0.01). The half-maximal concentration value was 0.04 +/- 0.05 microM in estrogen-treated rats and 0.4 +/- 0.1 microM in nontreated rats (p < 0.01). This response was inhibited by propranolol (1 microM) in both groups to a comparable extent (61.5%), and was unaffected by endothelial removal. Forskolin (0.01-10 microM) induced similar concentration-dependent vasodilation in arteries of both groups of rats with no differences in sensitivity or maximal response. These results suggest that isoprenaline acts through beta-adrenoceptors present on vascular smooth muscle and that estrogen replacement enhances the relaxant responses induced by beta-adrenoceptor activation by an endothelium-independent mechanism.

Animals↗
PubMedDate not supplied

[Neuropediatric clinical practice in a tertiary hospital of Basque Country].

INTRODUCTION: In our country, studies on the neuropediatric practice are scarce, in spite of their importance for planning of spending and resources, and definition of quality criteria. OBJECTIVE: To study the clinical workload of the main neuropediatric clinical problems. METHODS: Prospective, longitudinal, descriptive study of doctor-patient encounters, according to diagnosis, in the Child Neurology Division of a tertiaty hospital. RESULTS: 3,200 visits, of which 83% were ambulatory. 24 ambulatory visits per 1,000 inhabitants younger than 15 years, and year. Diagnosis demanding larger clinical activity for out-patients were: epilepsy/seizures (38%), mental retardation (17%), headaches (17%), hyperactivity/conduct disorders (12%), and cerebral palsy/permanent motor sequela (10%). Among in-patients: epilepsy/seizures (47%), mental retardation (10%), brain tumors/neurological complications of oncology disorders (8%), cerebral palsy/motor sequela (8%), and neurological complications of prematurity (7%). Among new out-patients, headaches is the most frequent diagnosis, followed by epilepsy; among new in-patients, epilepsy holds the first place, followed by neurological complications of prematurity and brain trauma. The index follow-up/first visit is much larger for the real neurologic patient than for functional disorders so frequent among new referrals. CONCLUSIONS: The neuropediatric practice comprises essentially epilepsy, cognitive and conduct disorders, and headaches. Unfortunately, our practice is in part being defined by the pressure exerted by the primary medical care and by hospital management practices.

Adolescent↗
PubMedDate not supplied

Solid-phase synthesis of bovine pancreatic trypsin inhibitor (BPTI) and two analogues. A chemical approach for evaluating the role of disulfide bridges in protein folding and stability.

The linear sequence of bovine pancreatic trypsin inhibitor (BPTI) has been assembled by stepwise Fmoc solid-phase peptide synthesis on a polyethylene glycol-polystyrene (PEG-PS) graft support with p-alkoxybenzyl ester anchoring. Similar methods were used to prepare two analogues, the first with all six half-cystine (Cys) residues replaced by alpha-amino-n-butyric acid (Abu), and the second with replacement of Abu at four Cys positions while retaining the native pairing between positions 14 and 38. Following cleavage from the support, the linear molecules (reduced form) were purified by semipreparative reversed-phase high performance liquid chromatography (HPLC). The native structure of BPTI was then formed by oxidation of a dilute solution of the protein at pH 8.7 in the presence of oxidized glutathione. The BPTI analogue with one disulfide bridge was obtained following treatment with dimethyl sulfoxide (DMSO)-pH 6 buffer (1:9). Overall yields of homogeneous proteins were 2-4%, and further characterization was provided by amino acid analysis, sequencing, ion electrospray mass spectrometry, analytical HPLC, and capillary zone electrophoresis (CZE). Purified synthetic BPTI with the native sequence was indistinguishable from natural material by the analytical and biophysical criteria applied, including circular dichroism (CD) spectra and inhibition of trypsin action. Studies are in progress to evaluate conformational features of the analogues which respectively lack two, or all three, of the native disulfide bridges.

Amino Acid Sequence↗