Outpatient intravenous multimodal elastomeric pump with methadone in ambulatory surgery. / Analgesia multimodal domiciliaria con metadona en perfusión intravenosa mediante bomba elastomérica en cirugía mayor ambulatoria.

BACKGROUND AND OBJECTIVE: Analgesia in Ambulatory Surgery (AS) needs to evolve in parallel with surgical complexity. We designed a study to try to improve analgesia in painful surgery using an intravenous elastomeric pump. As a novelty, methadone was included. PATIENTS AND METHODS: An observational study, physical status ASA I-II, underwent ambulatory surgeries with moderate-severe postoperative pain. Analgesia was administered for 48h by an intravenous multimodal elastomeric pump (methadone, tramadol, dexketoprofen and ondansetron at low doses). Visual Analogue Scale (VAS) at rest and movement were evaluated at 24 and 48h. Andersen Scale, Lattinen Test, rescue analgesia and side-effects were recorded at 24h after surgery. RESULTS: We included 73 patients: 37% abdominal wall surgery, 30% hemorrhoidectomies and 33% perineal surgery. Median VAS score at rest and movement were 0 and 3 at 24h, and 0 and 2 at 48h. At 24h, Andersen's Scale score was ≤1 in 89%, and Lattinen Test ≤6 in 90% of patients. Rescue medication was administered in 30% of patients. Two patients had vomiting at 24 and 48h. Minor catheter and pump dysfunctions were observed in 8% of patients. CONCLUSIONS: Multimodal analgesia with intravenous methadone administered by elastomeric perfusion at home is effective and safe. However, monitoring is needed to diagnosis dysfunction of devices.

Under-recognized renal insufficiency in hospitalized patients: implications for care.

BACKGROUND: The consequences of undetected low glomerular filtration rate (GFR) are important in hospitalized patients who receive potentially nephrotoxic drugs or undergo major surgery. This study estimated the prevalence of estimated GFR (eGFR) <60mL/min/1.73m(2) in hospitalized patients. METHODS: This cross-sectional descriptive study included 14,658 adults hospitalized at 10 centers in Spain. Serum samples were analyzed for hemoglobin, creatinine, albumin and urea nitrogen. eGFR was estimated using Modification of Diet in Renal Disease (MDRD) 4 or MDRD IDMS, and MDRD 6 when serum albumin and BUN were included (n=8611). Individuals were classified as having GFR>or=60mL/min/1.73m(2), stages 3, 4 and 5 (GFR 30-59, 15-29 and <15mL/min/1.73m(2), respectively). Additionally, stages 3a and 3b (GFR 45-59 and 30-44mL/min/1.73m(2), respectively) were assessed. RESULTS: MDRD 4 eGFR showed that 28.3% of patients had renal insufficiency stages 3-5 and 14.2% had stages 3b, 4 or 5, which represents important-severe renal deterioration. Forty-three percent of patients with stages 3-5 had hemoglobin or=60mL/min/1.73m(2). A good correlation was observed between eGFR MDRD 4 and MDRD 6. CONCLUSIONS: A high percentage of hospitalized patients in Spain have deteriorated renal function stages 3-5. Using eGFR equations to assess eGFR could identify more hospitalized patients with renal insufficiency, potentially leading to improved care.

Anestesia en consultorios / Anesthesia in the doctor's office

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Chromatin condensation and acrosome development during spermiogenesis of Ensis ensis (Mollusca, Bivalvia).

We describe chromatin condensation and acrosome development during spermiogenesis of Ensis ensis. The overall shape of the mature spermatozoon corresponds to the primitive type. The nucleus is oval and on its superior pole there is an elongated acrosome; the middle piece contains four mitochondria around the centriolar complex. The condensation of the nuclei seems to occur in three steps: first the diameter of chromatin fibers increases slightly from 17 to 20 nm; second, in midspermatids fiber pairs coalesce; and third, the coalescence continues by addition of other fibers until the nuclei become highly compacted. Chromatin changes are related with nuclear protein composition. Small proacrosomal vesicles show two regions of different electron density. At a later stage they fuse to give a single, spherical vesicle in round spermatids, which migrates to the upper pole and transforms into a tapered acrosome (18 microns long) with a central channel filled with finely fibrous material.

Differential expression and gonadal hormone regulation of histone H1(0) in the developing and adult rat brain.

The cellular distribution of histone H1(0) has been examined immunohistochemically in the rat brain. H1(0) accumulates in neurons and glial cells during postnatal development. In neurons, immunoreactivity increases progressively from about postnatal day 10, and reaches a distribution pattern similar to that of adult rats by postnatal day 20. Immunoreactivity in glial cells shows a prominent increase from postnatal day 20 to adult age. The accumulation of H1(0) during postnatal development appears to be correlated with terminal differentiation and maturation. Although immunoreactive neurons are widely distributed in all areas of the central nervous system, many neurons do not express immunoreactivity. For instance in the cerebellum, Purkinje neurons are negative. In females, the number of immunoreactive neurons in the arcuate area of the hypothalamus increases during postnatal development. In contrast, the percentage of immunoreactive neurons in males is low at all ages studied. The expression of H1(0) in the ventromedial part of the arcuate is reversibly and negatively regulated during the estrous cycle by the level of plasma estradiol. Ovariectomy increases the number of immunoreactive neurons while the restoration of the physiological levels of estradiol results in the opposite effect. Early postnatal androgenization of females suppresses the increment in the number of immunoreactive neurons in both the dorsolateral and the ventromedial parts of the arcuate during postnatal development, thus leading to permanently decreased levels of H1(0) immunoreactivity in postpuberal females.

Chromatin fibers with different protamine and histone compositions.

Previous studies have established that chromatin fibers which contain histones have variable diameters in different biological materials. In this paper we show that chromatin fibers are also present in spermatozoa and spermatids of bivalve molluscs in which some or all histones have been replaced by protamines. In all cases thick chromatin fibers are formed, with a diameter in the range 25-50 nm, depending on the species. We conclude that the formation of chromatin fibers is determined by the partial neutralization of the DNA charges with any histone or protamine, rather than due to a precise association of nucleosomes. This conclusion is in agreement with current theoretical work which shows that the diameter of complexes of DNA with counterions is determined by an overall balance of the interaction forces present.

Purification and immunocytolocalization of protein phi 0 from sperm cells of the echinoderm Holothuria tubulosa.

Histones in chromatin from germ cells of the echinoderm Holothuria tubulosa are retained throughout spermatogenesis. However, some alterations occur in the histone complement of the mature sperm, including the presence of a germ-line-specific H1 subcomponent unusually rich in arginine, and the appearance of a basic component termed phi 0. Histones from ripe sperm have been extracted in a preparative scale to allow for isolation and purification of protein phi 0. Polyclonal antibodies against phi 0 have been produced and purified by affinity chromatography. The specificity of the antibodies to phi 0 has been assessed by enzyme-linked immunosorbent assays, competition experiments, and Western immunoblotting analysis. No cross-reactivity of the antibodies with the remainder histone fractions has been observed. Immunocytolocalization of protein phi 0 by immunogold labeling has revealed that this protein is essentially confined to chromatin from ripe sperm, whereas it is wholly absent from less advanced germ cell types. From these observations, together with biochemical studies previously reported, it is inferred that protein phi 0 may well be instrumental in the known chromatin transitions occurring in this organism during germ cell development.

Conformational effects of histones H1 on DNA structure. Comparative study between H1-1, H1(0), H5 and sperm holothuria phi 0.

Interactions of mammalian histones, H1-1 and H1(0), phi 0 from holothuria sperm and H5 with poly(dA-dT), poly(dG-dC) and poly(dG-me5dC) were measured by a nitrocellulose filter binding assay and circular dichroism. All of the proteins bound to every one of the polymers, but differed in the extent of binding, which depended on the polynucleotide/protein ratios and ionic strength. The order of retention of all polymers was phi 0 greater than H1-1 greater than H1(0). The binding of H1(0) to poly(dG-me5dC) was remarkably sensitive to ionic strength. The proteins caused changes in the spectral features of the polynucleotides, but differed in the type and extent of the change. Complexes prepared with H1-1 and H1(0) with all polymers showed a strongly negative psi spectrum. Complexes of poly(dA-dT) and phi 0, at a protein/polynucleotide ratio of 0.4, displayed a distinctive spectrum, giving the appearance of a Z-like DNA spectrum, at low ionic strength. At higher ionic strength the complexes showed a psi spectrum. Complexes of poly(dG-me5dC) in the Z or B conformation with phi 0 showed spectral features characteristic of a mixture of a Z-like and a psi spectrum. In contrast, H5 reduced the Z-DNA spectral features in the presence of Mg, and produced an inversion of the B spectrum up to a polynucleotide/protein ratio of 0.24. These findings demonstrate the ability of different proteins to produce changes in the conformation of DNA. This may reflect the ability of chromatin to undergo differential condensation, depending on both the base composition of DNA and the type of H1 histone bound to it.