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Biomedical subjects

M Muñoz

Publications and source records attributed to M Muñoz.

At least 73 records · Page 4Linked to original sources
PubMed2000

Postoperative blood salvage and reinfusion in spinal surgery: blood quality, effectiveness and impact on patient blood parameters.

Although reinfusion of salvaged shed blood has become popular in major orthopaedic procedures, this blood saving technique is still controversial. In an effort to assess the functional and metabolic status of shed blood erythrocytes and the impact of postoperative shed blood reinfusion on allogenic blood requirements and patient's blood parameters, analyses of perioperative blood samples were performed in 28 consecutive orthopaedic patients undergoing spinal fusion, in which postoperative shed blood was collected and reinfused with the ConstaVac CBC II device. In comparison with a previous series of 31 patients, this procedure reduced allogenic blood requirements by almost 30% (P < 0.05), without any increase in postoperative complications. Postoperative shed blood presented lower haematological values and higher plasma-free haemoglobin (PFHB) levels than preoperative blood, without any disturbance in morphology, median corpuscular fragility (MCF) or erythrocyte adenosine triphosphate (ATP) and diphosphoglycerate (DPG) content. Serum concentrations of enzymes--glutamate-oxalacetate aminotransferase (GOT), glutamate-piruvate aminotransferase (GPT), creatine kinase (CK), lactate dehydrogenase (LDH)--and inflammatory cytokines (IL-1beta, IL-6) were elevated in shed blood. After reinfusion, there was no alteration in coagulation parameters or cytokine levels. Serum levels of some enzymes increased at the end of surgery and remained elevated at postoperative day 2 (CK) or 7 (GOT, LDH), with a higher increase if postoperative autotransfusion was used as a blood saving method. Therefore, caution should be taken when these serum enzyme levels are used for diagnosis. In conclusion, salvaged shed blood in orthopaedic procedures of the spine seems to be an excellent source of red cells which are not significantly damaged, keeping a normal functional and metabolic status, and reduces allogenic blood requirements without significant side effects.

Blood Cell Count↗
PubMed2000

Primary idiopathic chylopericardium in a 2 month old successfully treated without surgery.

The authors report a case of primary idiopathic chylopericardium in a previously healthy 2-month-old infant. He was treated with continuous pericardial drainage and low-fat total parenteral nutrition. He remains asymptomatic after 14 months of follow-up. This is the first report of primary idiopathic chylopericardium successfully treated nonoperatively.

Drainage↗
PubMed2000

Scintigraphic evolution of a breast cancer with Tc-99m MIBI scintimammography.

Early detection and prompt treatment of breast cancer are the main tools to decrease mortality rates. Several diagnostic techniques such as mammography, magnetic resonance imaging, and ultrasound are used, but none of these are conclusive. The authors describe a 56-year-old woman who was suspected of having breast cancer on mammography. Tc-99m MIBI scintimammography showed a small mass with elevated radiotracer uptake located near the pectoral muscle of the patient's left breast. The possible tumor was confirmed with fine-needle aspiration biopsy. After the diagnosis was established, the patient did not allow any treatment. Eighteen months later, a second scintimammography was performed, showing a large mammary tumor with a high radiotracer uptake, a new small lesion located in the left upper quadrant, and axillary lymph node involvement. Chemotherapy treatment was instituted and after treatment, Tc-99m MIBI scintimammography was normal. This case report provides further evidence for Tc-99m MIBI scintimammography for the detection of breast cancer as well as to evaluate the response to chemotherapy.

Antibiotics, Antineoplastic↗
PubMed2000

Usefulness of strontium-89 for bone pain palliation in metastatic breast cancer patients.

Most studies of prostate cancer have shown that strontium-89 chloride (89Sr) is effective in the palliation of metastatic bone pain, refractory to conventional analgesia. The aim of this study was to evaluate the usefulness of 89Sr for bone pain palliation in breast cancer patients. Forty women were treated with 148 MBq of 89Sr. Six patients were retreated, receiving two or more doses. The Karnofsky performance status was assessed and pain and analgesia were scored on scales of 9 and 5 points, respectively. The efficacy of 89Sr was evaluated at 3 months of treatment. The response was good in 60% of the patients and partial in 32%; there was no response in the remaining 8% (pre-treatment Karnofsky < or = 60). The duration of the response was 120+/-143 days. In the patients retreated, the response was good in 83% and partial in 17%, without significant differences compared with the first dose, but the pre-treatment Karnofsky and the duration of the efficacy were lower (P < 0.05). A transient and slight decrease of leukocyte and platelet counts after the first month of treatment with 59Sr was observed. In conclusion, breast cancer patients with metastatic bone pain can benefit from therapy with 89Sr. If necessary, the treatment may be repeated safely and with the same efficacy as is achieved after the first dose. A low functional performance status could be a cause of the lower effectiveness of 89Sr.

Aged↗
PubMed2000

Penaeidins, antimicrobial peptides with chitin-binding activity, are produced and stored in shrimp granulocytes and released after microbial challenge.

Penaeidins are members of a new family of antimicrobial peptides isolated from a crustacean, which present both Gram-positive antibacterial and antifungal activities. We have studied the localization of synthesis and storage of penaeidins in the shrimp Penaeus vannamei. The distribution of penaeidin transcripts and peptides in various tissues reveals that penaeidins are constitutively synthesized and stored in the shrimp haemocytes. It was shown by immunocytochemistry, at both optical and ultrastructural levels, that the peptides are localized in granulocyte cytoplasmic granules. The expression and localization of penaeidins were further analysed in shrimp subjected to microbial challenge. We found that (1) penaeidin mRNA levels decrease in circulating haemocytes in the first 3 hours following stimulation and (2) an increase in plasma penaeidin concentration occurs after microbial challenge, together with (3) a penaeidin immunoreactivity in cuticular tissue, which can be related to the chitin-binding activity we demonstrate here for penaeidins.

Amino Acid Sequence↗
PubMed2000

[Antibacterial activity of aminoglycosides against nosocomial strains of Acinetobacter baumannii isolated between 1990 and 1999].

The antibacterial activity of selected aminoglycosides against 487 nosocomial strains of Acinetobacter baumannii isolated from Chilean hospitals between 1990 and 1998 was investigated. Plasmid profiles were determined for some resistant isolates. A high frequency of resistant strains was found for all aminoglycosides assayed, with values ranging from 47% for amikacin (1990-1992) to 88% for gentamicin (1993-1994). The cure of a plasmid greater than 30 kb was associated with the loss of amikacin, kanamycin and neomycin resistance in some isolates. This result suggests that plasmid may harbor the genes encoding for the combination of aminoglycoside-modifying enzymes AAC(6')I+APH(3'). Gentamicin resistance was not lost among cured strains, suggesting it may be encoded by genes located on the bacterial chromosome or transposons inserted on the chromosome.

Acinetobacter↗
PubMed1999

Regulation of mammalian circadian behavior by non-rod, non-cone, ocular photoreceptors.

Circadian rhythms of mammals are entrained by light to follow the daily solar cycle (photoentrainment). To determine whether retinal rods and cones are required for this response, the effects of light on the regulation of circadian wheel-running behavior were examined in mice lacking these photoreceptors. Mice without cones (cl) or without both rods and cones (rdta/cl) showed unattenuated phase-shifting responses to light. Removal of the eyes abolishes this behavior. Thus, neither rods nor cones are required for photoentrainment, and the murine eye contains additional photoreceptors that regulate the circadian clock.

Animals↗
PubMed1999

Regulation of the mammalian pineal by non-rod, non-cone, ocular photoreceptors.

In mammals, ocular photoreceptors mediate an acute inhibition of pineal melatonin by light. The effect of rod and cone loss on this response was assessed by combining the rd mutation with a transgenic ablation of cones (cl) to produce mice lacking both photoreceptor classes. Despite the loss of all known retinal photoreceptors, rd/rd cl mice showed normal suppression of pineal melatonin in response to monochromatic light of wavelength 509 nanometers. These data indicate that mammals have additional ocular photoreceptors that they use in the regulation of temporal physiology.

Animals↗
PubMed1999

Targeted gene repair directed by the chimeric RNA/DNA oligonucleotide in a mammalian cell-free extract.

Chimeric oligonucleotides consisting of RNA and DNA residues have been shown to catalyze site-directed genetic alteration in mammalian cells both in vitro and in vivo. Since the frequency of these events appears to be logs higher than the rates of gene targeting, a process involving homologous recombination, we developed a system to study the mechanisms of chimera-directed gene conversion. Using a mammalian cell-free extract and a genetic readout in Escherichia coli, we find that point mutations and single base deletions can be corrected at frequencies of approximately 0.1% and 0.005%, respectively. The reaction depends on an accurately designed chimera and the presence of functional hMSH2 protein. The results of genetic and biochemical studies reported herein suggest that the process of mismatch repair functions in site-directed gene correction.

Animals↗
PubMed1999

Cholinergic and catecholaminergic neurons relay striatal information to the optic tectum in amphibians.

In the amphibians Rana perezi and Xenopus laevis, the involvement of cholinergic and catecholaminergic neurons in the relay of basal ganglia inputs to the tectum was investigated. Tract-tracing experiments, in which anterograde tracers were applied to the basal ganglia and retrograde tracers to the optic tectum, were combined with immunohistochemistry for choline acetyltransferase and tyrosine hydroxylase. The results of these experiments suggest that dopaminergic neurons of the suprachiasmatic nucleus and pretectal region, noradrenergic cells of the locus coeruleus and the cholinergic neurons of the pedunculopontine and laterodorsal tegmental nuclei mediate at least part of the basal ganglia input to the tectum in anurans.

Animals↗
PubMed1999

Age: a critical factor in cancer management. A prospective comparative study of 400 patients.

BACKGROUND: older people are often excluded from cancer treatments solely on the grounds of age. AIMS: to compare cancer treatment in older and younger patients. PATIENTS AND METHODS: between June 1992 and September 1994, 400 cancer patients were included in this prospective comparative study. The factors compared between younger and older subjects were performance status, associated chronic diseases, delay in diagnosis, stage of disease and initial treatment. RESULTS: 54 patients (25.5%) under 70 years of age were asymptomatic at the time of diagnosis, in comparison with 25 (12.5%) of the 200 older patients (P < 0.001). Associated chronic pathologies were more frequent in the older patients (55% vs 18.5%, P < 0.001). There were no statistical differences between both groups in diagnostic delay. Localized disease was found in 127 (63%) of the younger patients and in 109 (54%) of the older patients, the difference not being significant. The percentage of patients who underwent oncological treatment was higher in the younger than the older group (87.5% vs 56%, P < 0.001). The main cause of therapeutic exclusion in both groups was poor performance status; however, in the older group other variables--such as the presence of chronic disease and patients' or relatives' wishes and doctors' opinions--influenced the decision not to give specific treatment. CONCLUSIONS: this study confirms that the clinical characteristics and treatment of aged people with cancer are different from those of younger patients. Nevertheless, there is considerable doubt about whether an arbitrary age limit should continue to be accepted as a discriminatory factor in some diagnostic and therapeutic procedures in cancer patients.

Adolescent↗
PubMed1999

Selection of antibody probes to correlate protein sequence domains with their structural distribution.

We propose a new approach that permits correlation of specific domains defined by their primary sequence with their location in the structure of complex macromolecular aggregates. It is based on the combination of well-established structural analysis methods that incorporate the use of overlapping peptides on cellulose membranes for the isolation and purification of specific antibodies from a polyclonal antiserum. Monospecific antibodies to the connector protein of bacteriophage phi29 were isolated from polyclonal antisera using a new development of the spotscan method. These antibodies can be purified in quantities that allow antigenicity testing in enzyme-linked immunosorbent assays, Western blotting and immunoprecipitations, demonstrating the specificity of this isolation procedure. This approach has allowed us to generate direct antibody probes for immunoelectron microscopy mapping of different connector protein domains in a low resolution three-dimensional epitope map.

Amino Acid Sequence↗
PubMed1999

[Non-specific cecal ulcer in a patient with chronic renal failure in hemodialysis treatment. Case report].

We report a 65 years old female undergoing hemodialysis, presenting with intense pain in the lower right quadrant and moderate hematochezia. Since symptoms did not abate after an appendectomy, a colonoscopy and barium enema were performed, whose results suggested an advanced cecal carcinoma. Biopsies were negative for cancer. A new surgical abdominal exploration disclosed a cecal inflammatory and transmural lesion. A right colectomy was performed and the patient had a satisfactory postoperative evolution. Pathological study of the surgical piece showed a six cm perforated profound ulceration and a two cm ulcer. Both had precise limits. Unspecific cecal ulcers are rare entities that must be born in mind in the differential diagnosis of abdominal pain or hematochezia, specially in patients undergoing chronic hemodialysis.

Cecal Diseases↗
PubMed1999

Overcorrection after adjustable suture suspension- recession of the inferior rectus muscle in non-thyroid eye disease.

BACKGROUND AND PURPOSE: To assess the comparative risk of overcorrection in non-thyroid eye disease for adjustable suspension vs traditional recession surgery. To determine the ideal initial postop' binocular alignment for adjustable suture surgery. METHODS: Retrospective analysis of records of 31 patients. Thyroid eye disease excluded. All had inferior rectus recessions by either adjustable suspension-recession suture technique (20 patients) or traditional fixed recession technique (11 patients). RESULTS: None of 11 patients in the traditional recession group were overcorrected, one was undercorrected. Five of 20 patients who had adjustable suspension sutures had overcorrections which ranged from 6 to 18 prism diopters (PD), mean 12 PD. Two adjusted patients required additional surgery for their overcorrections. Statistical analysis of difference: 1/11 or 9.1% vs 5/20 or 25%, p=0.38. (="clinically/medically significant" for this study). CONCLUSIONS: Overcorrection is more frequent with the postop' adjustable suspension suture technique. If postop' adjustment is made, undercorrection is recommended.

Eye Movements↗
PubMed1998

Takayasu arteritis in Colombia.

Takayasu arteritis has been recognized in Colombia just recently, and so far we do not have any report concerning its presentation here. In this first report, some issues related to the presentation of the disease are indicated and compared with those found in the medical literature. No differences were found in age and sex. Most of the cases were diagnosed during an inactive phase of the disease with advanced manifestations due to vascular lesion which suggests the existence of some genetic factor influencing such a presentation, or may be the consequence of a delay in diagnosing the disease during initial and active stages due to not suspecting it. Comparing the vessels which are affected among other races and countries, we can find both differences and similarities. With the purpose of discovering the demographic, clinical, angiographic and laboratorial characteristics of Takayasu arteritis in Colombia, the present study was carried out by studying 35 clinical cases in different medical centers of the country.

Adolescent↗
PubMed1998

A new focus of cutaneous leishmaniasis due to Leishmania amazonensis in a Sub Andean region of Bolivia.

We detected a new outbreak focus with high incidence of cutaneous leishmaniasis in the Sub Andean region of La Paz. This area was never considered previously as an endemic zone of leishmaniasis. Leishmania stocks from human lesions were isolated: three stocks were explored by pulse field gradient electrophoresis, showing evidence for their affiliation to the L. mexicana complex. Eight stocks were submitted to isoenzyme electrophoresis and compared with five reference strains: L. amazonensis, L. braziliensis, L. chagasi, L. mexicana and L. pifanoi. Close genetic proximity was evidenced between newly isolated parasites and the reference stock of L. amazonensis, whereas high divergence was observed between them and either the L. pifanoi, L. mexicana, L. braziliensis and L. chagasi reference strains.

Animals↗
PubMed1998

Role of two conserved glycine residues in the beta-propeller domain of the integrin alpha4 subunit in VLA-4 conformation and function.

The N-terminal region of the alpha integrin subunits is predicted to fold into a beta-propeller domain. Using K562 alpha4 transfectants we show that mutations at alpha4 subunit residues Gly130 and Gly190 affect the conformation of this domain causing a reduction in the recognition of alpha4 by anti-alpha4 antibodies which map to the beta-propeller. The improper alpha4 conformation also led to an altered association with the beta1 subunit, and to a lack of alpha4beta1 adhesion to VCAM-1 and CS-1/fibronectin, as well as an abolishment of anti-alpha4- and anti-beta1-dependent homotypic aggregation. The total conservation of Gly130 and Gly190 among integrin alpha subunits suggests their importance in the correct folding of their respective beta-propeller domains, and thus, in the adhesive activity of the integrins.

Antigens, CD↗