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Biomedical subjects

M Muñoz

Publications and source records attributed to M Muñoz.

At least 37 records · Page 2Linked to original sources

Lick Observatory Optical SETI: targeted search and new directions.

Lick Observatory's Optical SETI (search for extraterrestrial intelligence) program has been in regular operation for 4.5 years. We have observed 4,605 stars of spectral types F-M within 200 light-years of Earth. Occasionally, we have appended objects of special interest, such as stars with known planetary systems. We have observed 14 candidate signals ("triple coincidences"), all but one of which are explained by transient local difficulties. Additional observations of the remaining candidate have failed to confirm arriving pulse events. We now plan to proceed in a more economical manner by operating in an unattended drift scan mode. Between operational and equipment modifications, efficiency will more than double.

Astronomical Phenomena↗

Utility of point-of-care haemoglobin measurement in the HemoCue-B haemoglobin for the initial diagnosis of anaemia.

Measurement of haemoglobin (Hb) concentration provides a reliable indication of the presence and severity of anaemia. However, other laboratory parameters are usually requested as well, leading to an increase in socio-sanitary costs. Accordingly, this study was undertaken to ascertain the reliability of point-of-care Hb determination with the portable photometer HemoCue-B haemoglobin (HBH) and to evaluate its utility for the initial diagnosis of anaemia. Hb was measured (x3) in 20 venous blood samples diluted with saline (v/v; 1 : 0, 2 : 1, 1 : 1, 2 : 1 and 3 : 1) to obtain a wide range of Hb and in venous and capillary blood samples from 247 primary health care patients. All HBH results were compared with those yielded by the reference cell counter Pentra 120 Retic (ABX). In diluted samples, Hb values obtained with either method were not significantly different (ABX-HBH, -0.01 +/- 0.32 g/dl; 95% CI, -0.04 to 0.028 g/dl) and showed an excellent Pearson's coefficient of correlation (r = 0.992; P < 0.01). HBH provides accurate values if at least 4 mul of blood is loaded into the cuvette. There were no significant differences between Hb measured in venous (v) and capillary (c) blood samples in primary care patients. Eighteen anaemic patients were detected by ABX measurements (7.3%; 15 female/3 male), 18 by HBHv (specificity, 100%; sensitivity, 100%) and 25 by HBHc (eight false positives; one false negative; specificity, 94.4%; sensitivity, 96.5%). Compared with ABX, HBH provides accurate and precise measurements for a wide range of Hb and its use in primary health care seems to be a good method for the initial diagnosis of anaemia.

Anemia↗

Impact of postoperative shed blood transfusion, with or without leucocyte reduction, on acute-phase response to surgery for total knee replacement.

BACKGROUND: In patients undergoing total knee replacement (TKR) most blood loss occurs postoperatively and return of unwashed filtered shed blood (USB) from postoperative drainage may represent an alternative to allogeneic blood transfusion (ABT). We evaluated the impact of USB return, with or without leucocytes, on the acute-phase response (APR) after TKR. PATIENTS AND METHODS: Forty-eight TKR patients, intended to receive postoperative USB, entered the study. Blood samples were obtained before and 6, 24, 72 h and 7 days after surgery, and from the USB before and after it passed through a 40-microm filter (Group F40) or a leucocyte-reduction filter (Group LRF). Haematimetric parameters, APR proteins (albumin, prealbumin, ceruloplasmin, haptoglobin, C-reactive protein), complement C3 and C4, and cytokines (IL-1beta, IL-6, IL-8, IL-10, and TNF-alpha) were measured in all samples. RESULTS: Twenty-eight patients (Group F40=14, Group LRF=14) received a mean of 1.2 USB units, without any clinically relevant incident, and did not need additional ABT. Sixteen out of the 20 remaining patients who received neither USB nor ABT served as a control group for the postoperative APR study. All patients showed the typical postoperative APR profile and there were no significant differences between groups for APR parameters, postoperative complications, or hospital stay. CONCLUSIONS: Postoperative blood salvage and return, with or without a LRF, after TKR does not present any clinically relevant side-effects and does not modify APR induced by surgery. These findings seem to confirm the clinical experience that postoperative USB return is safe and questions the beneficial effect of using LRF.

Acute-Phase Reaction↗

Perioperative stimulation of erythropoiesis with intravenous iron and erythropoietin reduces transfusion requirements in patients with hip fracture. A prospective observational study.

BACKGROUND AND OBJECTIVES: Patients undergoing surgery for hip fracture (HF) often receive perioperative allogeneic blood transfusions (ABT) to avoid anaemia. However, concerns about the adverse effects of ABT have prompted the review of transfusion practice and the search for a safer treatment of perioperative anaemia. MATERIALS AND METHODS: We prospectively investigated the effect of a blood-saving protocol of perioperative iron sucrose (3 x 200 mg/48 h, intravenously) plus erythropoietin (1 x 40,000 IU, subcutaneously) if admission haemoglobin level < 130 g/l, on transfusion requirements and postoperative morbid-mortality in patients with HF (group 2; n= 83). A parallel series of 41 HF patients admitted to another surgical unit within the same hospital served as the control group (group 1). Perioperative blood samples were taken for haematimetric, iron metabolism and inflammatory parameter determination. RESULTS: This blood-saving protocol reduced the number of transfused patients (P < 0.001), the number of transfused units (P < 0.0001), increased the reticulocyte count and improved iron metabolism. In addition, the blood-saving protocol also reduced the rate of postoperative infections (P = 0.016), but not the 30-day mortality rate or the mean length of hospital stay. CONCLUSIONS: The blood-saving protocol implemented seems to reduce ABT requirements in patients with HF, and is associated with a lower postoperative morbidity. The possible mechanisms involved in these effects are discussed.

Aged↗

Reciprocal connections between olfactory structures and the cortex of the rostral superior temporal sulcus in the Macaca fascicularis monkey.

Convergence of sensory modalities in the nonhuman primate cerebral cortex is still poorly understood. We present an anatomical tracing study in which polysensory association cortex located at the fundus and upper bank of the rostral superior temporal sulcus presents reciprocal connections with primary olfactory structures. At the same time, projections from this polysensory area reach multiple primary olfactory centres. Retrograde (Fast Blue) and anterograde (biotinylated dextran-amine and 3H-amino acids) tracers were injected into primary olfactory structures and rostral superior temporal sulcus. Retrograde tracers restricted to the anterior olfactory nucleus resulted in labelled neurons in the rostral portion of the upper bank and fundus of superior temporal sulcus. Injections of biotinylated dextran-amine at the fundus and upper bank of the superior temporal sulcus confirmed this projection by labelling axons in the dorsal and lateral portions of the anterior olfactory nucleus, as well as piriform, periamygdaloid and entorhinal cortices. Retrograde tracer injections at the rostral superior temporal sulcus resulted in neuronal labelling in the anterior olfactory nucleus, piriform, periamygdaloid and entorhinal cortices, thus providing confirmation of the reciprocity between primary olfactory structures and the cortex at the rostral superior temporal sulcus. The reciprocal connections between the rostral part of superior temporal sulcus and primary olfactory structures represent a convergence for olfactory and other sensory modalities at the cortex of the rostral temporal lobe.

Amino Acids↗

Formulations of hydrogels and lipogels with vitamin E.

Vitamin E, a topically administered antioxidant, reduces erythema, photoaging, photocarcinogenesis, edema, and skin hypersensitivity associated with exposure to ultraviolet B (UVB) radiation. Virgin olive oil, which also has antioxidant properties, reduces the number of, and delays the onset of skin cancer induced by UVB radiation when used after sunbathing. Topical use after sunbathing of formulations that contain virgin olive oil and vitamin E may therefore reduce the number and delay the onset of UVB-related skin cancer in humans. We designed formulations of gels with olive oil (lipogels) and hydrogels containing 2% tocopherol. The formulations were optimized on the basis of rheological, organoleptic, biopharmaceutical, and cosmetic criteria. Different formulae for hydrogels with vitamin E were ideal for application after exposure to solar radiation because of their good organoleptic properties. Vitamin E lipogels are of potential use in cosmetics such as locally acting anti-aging treatments because of the antioxidant effects of vitamin E.

Journal Article↗

Transfusion of post-operative shed blood: laboratory characteristics and clinical utility.

Increased awareness of the potential hazards of allogenic blood transfusion, such as incompatibility reactions, metabolic and immunologic disorders, or transmission of viral diseases, has led to an emphasis on allogeneic blood alternatives. For orthopaedic surgery, several autologous transfusion modalities have emerged as alternatives to allogeneic blood transfusion, avoiding its immunomodulatory effects. Among them, transfusion or return of post-operative salvaged shed blood has become popular in major orthopaedic procedures. However, although the effectiveness of this blood-saving method is well documented, several authors have questioned its safety and recommended the use of washed blood. Therefore, this review analyses the haematologic characteristics of unwashed filtered shed blood, including metabolic status and survival of red blood cells, the components of the haemostatic system, the content of fat particles, bacterial and tumour cells and the possibility of their removal, the content of inflammatory mediators, and the effects on the patient's immune system. From data reviewed in this paper, it can be concluded that post-operative salvage of blood seems to be an excellent source of functional and viable red cells without many of the transfusion-related risks and with some immuno-stimulatory effects. In addition, from our experience, post-operative re-infusion of unwashed shed blood after major spine procedures has proved to reduce post-operative homologous transfusion requirements and to complement pre-operative autologous blood donation, without any clinically relevant complication.

Blood Loss, Surgical↗

The covalent coupling of HAV-VP3 (110-121) synthetic peptide to liposomes: physicochemical studies.

In this work we have studied the conjugation of the immunogenic peptide sequence (110-121) belonging to the VP3 capsid protein of hepatitis A virus to the surface of preformed liposomes by means of an amide bond between the vesicles and the synthetic peptide. The surface activity of the conjugate at air/water interface was determined. Moreover, the interaction of the conjugate with lipids was also studied recording the pressure increases produced after the injection of the liposome-peptide preparation under dipalmitoylphosphatidylcholine (DPPC), dipalmitoylphosphatidylglycerol (DPPG) and stearylamine (SA) monolayers at different initial surface pressures. As expected, due to the negative net charge of the liposome-peptide complex, the higher interaction was found with positive charge monolayers (SA). However, the conjugate was also able to incorporate to zwitterionic and anionic lipids. This behaviour was also confirmed performing compression isotherms of monolayers of these lipids spread on subphases containing the conjugate. These results suggest that the coupling of VP3 (110-121) to liposomes does not influence its ability to interact with membrane lipids such as DPPC and DPPG. Then it can be assumed that its immunogenicity will be preserved or even increased after this modification. All these results are also useful in the preparation of liposome-based synthetic peptide vaccines.

Capsid Proteins↗

A novel promoter polymorphism in the gene encoding complement component 5 receptor 1 on chromosome 19q13.3 is not associated with asthma and atopy in three independent populations.

BACKGROUND: The inflammatory functions of complement component 5 (C5) are mediated by its receptor, C5R1, which is expressed on bronchial, epithelial, vascular endothelial and smooth muscle cells. A susceptibility locus for murine allergen-induced airway hyper-responsiveness was identified in a region syntenic to human chromosome 19q13, where linkage to asthma has been demonstrated and where the gene encoding C5R1 is localized. OBJECTIVE: The aim of this study was to screen for novel polymorphisms in the C5R1 gene and to determine whether any identified polymorphisms are associated with asthma and/or atopy and whether they are functional. METHODS: Single-nucleotide polymorphism (SNP) detection in the gene encoding C5R1 was performed by direct sequencing. Genotyping was performed in three populations characterized for asthma and/or atopy: (1) 823 German children from The Multicenter Allergy Study; (2) 146 individuals from Tangier Island, Virginia, a Caucasian isolate; and (3) asthma case-parent trios selected from 134 families (N=783) in Barbados. Functional studies were performed to evaluate differences between the wild-type and the variant alleles. RESULTS: We identified a novel SNP in the promoter region of C5R1 at position -245 (T/C). Frequency of the -245C allele was similar in the German (31.5%) and Tangier Island (36.3%) populations, but higher in the Afro-Caribbean population (53.0%; P=0.0039 to <0.0001). We observed no significant associations between the -245 polymorphism and asthma or atopy phenotypes. Upon examination of the functional consequences of the -245T/C polymorphism, we did not observe any change in promoter activity. CONCLUSION: This new marker may provide a valuable tool to assess the risk for C5a-associated disorders, but it does not appear to be associated with asthma and/or atopy.

Asthma↗

Serial topoisomerase II expression in primary breast cancer and response to neoadjuvant anthracycline-based chemotherapy.

OBJECTIVE: We analyzed the value of topoisomerase IIalpha (Topo II) in predicting the clinical response to anthracycline-based neoadjuvant chemotherapy in breast cancers and the potential changes in Topo II after chemotherapy. In parallel, HER2, which is commonly coexpressed with Topo II, and p53, a modulator of chemotherapy activity, were also analyzed. METHODS: Forty-one patients with primary breast cancer and treated with neoadjuvant anthracycline-based chemotherapy (FAC or FEC) were included for the present study. Topo II, HER2 and p53 expression were measured by immunohistochemistry in pre and post chemotherapy (at the time of surgery), tumor specimens and the results were correlated with the clinical response. RESULTS: Topo II was overexpressed in 16 of 41 (31%) tumors before treatment, and this overexpression was significantly associated with clinical response (p = 0.03). HER2 and p53 were unrelated to response. Notably, Topo II overexpression, but not HER2 or p53, was lost in specimens after chemotherapy (p = 0.01). CONCLUSION: The observed link between Topo II and the clinical response to neoadjuvant anthracycline-based chemotherapy, together with its loss after chemotherapy, implies that Topo II deserves further testing in a prospective setting as a predictive marker.

Adult↗

Antitumoural action of L-733,060 on neuroblastoma and glioma cell lines.

We have performed an in vitro study of the growth-inhibitory capacity of the potent and long-acting NK1 receptor antagonist L-733,060, at concentrations ranging from 2.5 microM to 20 microM, against the neuroblastoma cell line SKN-BE(2) and 10 microM to 25 microM for glioma cell line GAMG. Coulter counter was used to determine viable cell numbers, followed by application of the tetrazolium compound [3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)2-(4-sulfophenyl)-2H-tetrazolium], inner salt colorimetric method to evaluate cell viability in this cytotoxicity assay. L-733,060 inhibited the growth of the two cell lines studied in a dose-dependent manner. The IC 50 values were 11.6 microM (30h) and 10.2 microM (72h) for SKN-BE(2); and 21.3 microM (48h) and 19.9 microM (96h) for GAMG. These findings indicate that the NK1 receptor antagonist L-733,060 acts as a broad-spectrum antitumoural agent. This new action, reported here for the first time, suggests that the NK1 receptor antagonist L-733,060 could be a promising therapeutic drug for the treatment of human neuroblastoma and human glioma.

Antineoplastic Agents↗

Using molecular markers to assess the effect of introgression on quantitative attributes of common bean in the Andean gene pool.

Progress in bean breeding programs requires the exploitation of genetic variation that is present among races or through introgression across gene pools of Phaseolus vulgaris L. Of the two major common bean gene pools, the Andean gene pool seems to have a narrow genetic base, with about 10% of the accessions in the CIAT core collection presenting evidence of introgression. The objective of this study was to quantify the degree of spontaneous introgression in a sample of common bean landraces from the Andean gene pool. The effects of introgression on morphological, economic and nutritional attributes were also investigated. Homogeneity analysis was performed on molecular marker data from 426 Andean-type accessions from the primary centres of origin of the CIAT common bean core collection and two check varieties. Quantitative attribute diversity for 15 traits was studied based on the groups found from the cluster analysis of marker prevalence indices computed for each accession. The two-group summary consisted of one group of 58 accessions (14%) with low prevalence indices and another group of 370 accessions (86%) with high prevalence indices. The smaller group occupied the outlying area of points displayed from homogeneity analysis, yet their geographic origin was widely distributed over the Andean region. This group was regarded as introgressed, since its accessions displayed traits that are associated with the Middle American gene pool: high resistance to Andean disease isolates but low resistance to Middle American disease isolates, low seed weight and high scores for all nutrient elements. Genotypes generated by spontaneous introgression can be helpful for breeders to overcome the difficulties in transferring traits between gene pools.

Breeding↗

Acute phase response in patients undergoing lumbar spinal surgery: modulation by perioperative treatment with naproxen and famotidine.

In orthopaedic surgery, perioperative administration of non-steroidal anti-inflammatory drugs has been shown to reduce postoperative pain and analgesic consumption. In addition, preoperative administration of ibuprofen has proved to reduce interleukin-6 (IL-6) release, while that of ranitidine reduced postoperative IL-6-induced C-reactive protein synthesis in patients undergoing abdominal surgery. However, it has not been established whether the preoperative administration of both types of drugs may reduced the postoperative inflammatory reaction after instrumented spinal surgery. Accordingly, our objective was to investigate the effects of preoperative treatment with naproxen plus famotidine on the postoperative systemic inflammatory reaction in patients undergoing instrumented lumbar spinal surgery. Forty consecutive patients scheduled for elective instrumented spinal fusion were alternately assigned to receive either naproxen (500 mg/day, p.o.) plus famotidine (40 mg/day, p.o.) for 7 days before operation, or no adjuvant treatment. Haematological parameters, acute phase proteins, complement fractions, immunoglobulins and cytokines were determined 7 days and immediately before surgery, and on days 0, 1, 2 and 7 after surgery. Haematological parameters, clinical data, duration of surgery, blood loss, perioperative blood transfusion and postoperative complications were similar in the two groups, although pretreated patients showed lower increases in body temperature and required less analgesic medication. Compared with preoperative levels, IL-6 levels were significantly increased postoperatively in all patients with no differences between groups. C-reactive protein, alpha(1)-acid-glycoprotein and haptoglobin levels were also significantly increased postoperatively in all patients; however, they were significantly lower in pretreated patients. In conclusion, perioperative treatment with naproxen plus famotidine was well tolerated and reduced the acute phase response after instrumented spinal surgery. However, further research is needed to determine the best dose and timing of preoperative treatment administration, and to correlate these changes with long-term clinical results.

Acute-Phase Reaction↗

Postnatal development of calcium-binding proteins immunoreactivity (parvalbumin, calbindin, calretinin) in the human entorhinal cortex.

The entorhinal cortex is an essential component in the organization of the human hippocampal formation related to cortical activity. It transfers, neocortical information (ultimately distributed to the dentate gyrus and hippocampus) and receives most of the hippocampal output directed to neocortex. At birth, the human entorhinal cortex presents similar layer organization as in adults, although layer II (cell islands) and upper layer III have a protracted maturation. The presence of interneurons expressing calcium-binding proteins (parvalbumin, calbindin-D28K (calbindin) and calretinin) is well documented in the adult human entorhinal cortex. In many of them the calcium binding is co-localized with GABA. Parvalbumin-immunoreactive cells and fibers were virtually absent at birth, their presence increasing gradually in deep layer III, mostly in the lateral and caudal portions of the entorhinal cortex from the 5th month onwards. Calbindin immunoreactive cells and fibers were present at birth, mainly in layers II and upper III; mostly at rostral and lateral portions of the entorhinal cortex, increasing in number and extending to deep layers from the 5th month onwards. Calretinin immunoreactivity was present at birth, homogeneously distributed over layers I, II and upper V, throughout the entorhinal cortex. A substantial increase in the number of calretinin neurons in layer V was observed at the 5th month. The postnatal development of parvalbumin, calbindin and calretinin may have an important role in the functional maturation of the entorhinal cortex through the control of hippocampal, cortical and subcortical information.

Calbindin 1↗

[Parotid tuberculosis following intravesical BCG instillation: a case report].

First case of parotid gland tuberculosis publicated to date is presented after intravesical instillation of BCG for a superficial bladder cancer. The diagnosis of the parotid gland tuberculosis is difficult because it is usually indistinguishable from a neoplasm. Combined fine-needle aspiration cytology with PCR or LCR amplification of mycobacterial DNA could be a good diagnostic tool avoiding an open biopsy.

Administration, Intravesical↗

Universal scaling of ballistic magnetoresistance in magnetic nanocontacts.

We show that ballistic magnetoresistance exhibits universal scaling in atomic or nanometer scale contacts. Plotting the data as conductance, we find that, if the maximum magnetoconductance is normalized to unity and the conductance is scaled with the conductivity of the bulk material, the data fall in a narrow region, independent of the nanocontact materials, for our four data sets and four from the literature. The results agree with a theory that takes into account spin-scattering within a magnetic-domain wall.

Journal Article↗