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Biomedical subjects

M Muñoz

Publications and source records attributed to M Muñoz.

At least 91 records · Page 5Linked to original sources
PubMed1998

Localization of adrenomedullin-like immunoreactivity in the hypothalamo-hypophysial system of amphibians.

The presence of adrenomedullin-like immunoreactive (AMi) cell bodies and fibers in the hypothalamus and hypophysis of the amphibians Rana perezi (anuran) and Pleurodeles waltl (urodele) was examined by immunohistochemistry. A large population of AMi neurons was found in the suprachiasmatic nucleus of both species. Differently, AMi cells in the magnocellular nucleus of the preoptic area were only found in the urodele, whereas dispersed cells in the caudal infundibular region were exclusively present in the anuran. This different staining pattern is reflected in the hypophysis where the neural lobe is primarily immunoreactive in the urodele while the labeling in the intermediate lobe prevailed in the anuran. The results strongly suggest that, as is mammals, the AM in amphibians may play an important regulatory role in the hypothalamo-hypophysial system.

Adrenomedullin↗
PubMed1998

p21WAF1/Cip1 is associated with cyclin D1CCND1 expression and tubular differentiation but is independent of p53 overexpression in human breast carcinoma.

p21WAF1/Cip1 is an inhibitor of cdk/cyclin complexes, and thus regulates the cell cycle. p21 is also related to cell differentiation and is regulated by wild-type p53, although p53-independent regulatory pathways have been proposed. In order to analyse p21 expression as well as its relationship with p53 in human breast cancer, an immunohistochemical analysis was undertaken of 77 breast carcinomas, 16 of them with an in situ component; 30 adjacent normal tissue samples; and five non-neoplastic specimens. Forty-four infiltrating carcinomas (57 per cent) were p21-positive. Expression of p21 was also observed in pre-invasive lesions, whereas normal ducts were negative or focally and weakly positive. p21 expression was associated with high histological grade (II + III) (P = 0.017) and poor tubule formation (P = 0.002), and was significantly less frequent in lobular carcinomas (P = 0.0001). p21 positivity also correlated with increased proliferation, but this seemed to be dependent on the histological grade. Twenty carcinomas (26 per cent) showed p53 overexpression, but this was not associated with p21 negativity, suggesting the existence of p53-independent mechanisms for p21 regulation in vivo. Cyclin D1CCND1 expression was analysed in the same series and an association between p21 and cyclin D1 expression was found, since 23 of 26 cyclin D1-positive carcinomas were p21-positive (P < 0.001 ...). In conclusion, p21 is frequently overexpressed in breast carcinomas and this occurs in the early stages of neoplastic progression. This overexpression seems to be independent of p53 status and might be involved in cyclin D1 modulation.

Blotting, Western↗
PubMed1998

Management of acquired rectourinary fistulas: outcome according to cause.

PURPOSE: Acquired rectourinary fistulas, an infrequent complication of pelvic conditions, remain a therapeutic problem for which neither a widely accepted classification nor long-term outcome data are available. This study was designed to provide a new etiologic classification system and examine the success of various surgical therapies. It also looked at the need for permanent fecal or urinary diversion or radical excision depending on the cause of the fistula, i.e., benign vs. malignancy-related. METHODS: A retrospective analysis was made of 41 patients treated for acquired rectourinary fistulas between 1980 and 1995. Acquired rectourinary fistulas were classified as 1) benign but caused by Crohn's disease, trauma, perirectal sepsis, or iatrogenic injury; and 2) malignancy-related fistulas secondary to neoplasm, radiation, surgery, or combined tumor and treatment effects. Surgical interventions were classified as repair, excision, fecal diversion, and urinary diversion. RESULTS: Thirty-seven males and 4 females with acquired rectourinary fistula were identified with a mean age of 62 (range, 28-90) years. Nineteen patients had fistulas involving their urethras, and 22 patients had fistulas involving the bladder. Eight patients were not treated surgically; one was not treated because of an advanced malignancy, three because of patient preference, three because of sepsis, and one because of a poor general condition. Of the remaining 33 patients, nine had benign fistulas of which two were the result of Crohn's disease, two were the result of trauma, two were from an iatrogenic response, and three were from perirectal sepsis. Twenty-four patients had malignancy-related fistulas, and five patients had neoplasm at their fistula sites. The remaining 19 patients had malignancy-related fistulas that were the result of cancer treatments. Of the 19 malignancy-related fistulas, 5 were from radiation, 9 were from surgical trauma, and 5 were from radiation and surgical trauma. Forty-nine percent of the patients had undergone attempts at fistula treatment before referral. A resolution of symptoms after initial and reoperative surgery occurred more often in patients with benign fistulas (44 and 100 percent; mean, 1.8 surgeries per patient) compared with malignancy-related fistulas (21 and 88 percent; mean, 2.1 surgeries per patient). The rates of permanent fecal, urinary, and fecal plus urinary diversion were also lower for benign fistulas (11, 0, and 33 percent) compared with malignancy-related fistulas (13, 8, and 54 percent). Permanent diversion was avoided in 56 percent of the benign fistulas but in only 25 percent of the malignancy-related fistulas. The rates of excisional and radical (ileal conduit) surgery were lower for benign fistulas than for malignancy-related fistulas (44 and 11 percent vs. 50 and 54 percent). CONCLUSION: Successful management of rectourinary fistulas typically requires aggressive reoperative therapy with permanent diversion more often required for malignancy-related fistulas. Better outcomes can be anticipated for benign fistulas.

Adult↗
PubMed1998

Differential patterns of mental disorders among the homeless in Madrid (Spain) and Los Angeles (USA).

In this paper we compare rates of mental disorders (major depression, dysthymia, cognitive impairment, and schizophrenia) among homeless people in Madrid and Los Angeles (LA) and examine the ordering of the onset of both conditions (i.e., homelessness and mental disorders). In the Madrid study, 262 homeless persons were interviewed using the CIDI. In the LA study, 1563 homeless persons were interviewed with the DIS. To make an item-by-item comparison, we companied the databases from both studies to submit a single database to statistical analyses. Results showed no significant differences in DSM-III-R life-time prevalence rates of mental disorders between both samples. However, the Madrid sample showed higher 12-month prevalence rates of dysthymia and cognitive impairment as compared to the LA sample. Most subjects across both cities first experienced symptoms of their mental disorders before first becoming homeless. The only significant difference was that all of the depressed adults in Madrid experienced depression prior to first becoming homeless, whereas this was the case for only 59.1% of LA depressed homeless people. We discuss the reasons for these cultural differences and their implications for cross-national public health research and intervention.

Adolescent↗
PubMed1998

Bone mineral density in children and adolescents with diabetes mellitus type 1 of recent onset.

There is still controversy over the impact of diabetes control and duration on bone mass and growth parameters in children and adolescents with insulin-dependent diabetes mellitus (IDDM). The aim of this study was to assess bone mineral density (BMD) at axial and appendicular sites, in children with noncomplicated IDDM of recent onset, and its relation to metabolic control and auxological parameters (weight, height, and puberal stage). Fifty-five young Spanish IDDM, otherwise healthy patients (26 males, aged (SD 9.7 +/- 4.3 years) and 29 females, aged (SD 11.2 +/- 3.8 years) were studied. Duration of diabetes was 1-13.8 years. Two hundred eighty-two age-matched, healthy, Spanish children served as controls. HbA1 was assayed by high pressure liquid chromatography (HPLC) and BMD was measured using dual X-ray absorptiometry (DXA) densitometry at the spine and forearm. Results showed a Gaussian BMD distribution of patients according to sex and age, without sexual-stage differences. There was no correlation between BMD and glycated hemoglobin (average life disease or last HbA1 values) or duration of the disease; moreover, no differences in bone mass were found between <3 and >/=3 years of disease duration. Diabetes impact index (mean HbA1 x duration of disease in months) showed no significant influence of diabetes control on BMD. We could not demonstrate any impact of diabetes on BMD and growth parameters in children with IDDM of short duration.

Absorptiometry, Photon↗
PubMed1998

Human papillomavirus (HPV) DNA assay as an adjunct to liquid-based Pap test in the diagnostic triage of women with an abnormal Pap smear.

OBJECTIVE: The diagnostic performance and clinical value of the combined use of liquid-based Pap test and human papillomavirus testing were determined in 336 patients with a previous abnormal smear. METHOD: Subsequent histologic evaluation was used as definitive diagnosis. RESULT: The combined use of liquid-based Pap test and HPV DNA testing showed higher rates in sensitivity (99.0%), specificity (59.3%), positive predictive value (89.9%) and negative predictive value (94.5%) than either cytology alone (sensitivity 98.8%, specificity 45.7%, positive predictive value 84.7%, negative predictive value 92.6%) or HPV DNA testing alone (sensitivity 84.9%, specificity 67.4%, positive predictive value 88.8%, negative predictive value 59.5%). CONCLUSION: The study demonstrated that the diagnostic accuracy for cervical cancer and its precursors was improved by using the liquid-based Pap test as a primary diagnostic procedure and HPV assay as an adjunctive test. This information may assist the clinicians in triaging patients with equivocal cytologic cervical atypias.

Adolescent↗
PubMed1998

Physico-chemical characterization of liposomes with covalently attached hepatitis A VP3(101-121) synthetic peptide.

The covalent conjugation of a 20-mer peptide belonging to the VP3 capsid protein of hepatitis A virus to the surface of preformed liposomes was investigated. Three different bonds (disulfide, thioether and amide) were established between the peptide sequence and liposomes bearing at their surface appropriate reactive groups. The effect of the relative concentration of the N-[4-(p-maleimidophenyl)butyryl]dipalmitoylphosphatidylethanolamine anchor in liposomes on stability during coupling of the peptide sequence was studied. The interaction of the three liposomal preparations with phospholipids in a biomembrane model system, monolayers at the air-water interface, is also reported. The results showed that although the peptides associate with liposomes in similar yields for the three strategies studied, differences can be observed when their interaction with phospholipid monolayers composed of dipalmitoylphosphatidylcholine is analysed.

Adjuvants, Immunologic↗
PubMed1998

Analysis of rotavirus nonstructural protein NSP5 phosphorylation.

The rotavirus nonstructural phosphoprotein NSP5 is encoded by a gene in RNA segment 11. Immunofluorescence analysis of fixed cells showed that NSP5 polypeptides remained confined to viroplasms even at a late stage when provirions migrated from these structures. When NSP5 was expressed in COS-7 cells in the absence of other viral proteins, it was uniformly distributed in the cytoplasm. Under these conditions, the 26-kDa polypeptide predominated. In the presence of the protein phosphatase inhibitor okadaic acid, the highly phosphorylated 28- and 32- to 35-kDa polypeptides were formed. Also, the fully phosphorylated protein had a homogeneous cytoplasmic distribution in transfected cells. In rotavirus SA11-infected cells, NSP5 synthesis was detectable at 2 h postinfection. However, the newly formed 26-kDa NSP5 was not converted to the 28- to 35-kDa forms until approximately 2 h later. Also, the protein kinase activity of isolated NSP5 was not detectable until the 28- and 30- to 35-kDa NSP5 forms had been formed. NSP5 immunoprecipitated from extracts of transfected COS-7 cells was active in autophosphorylation in vitro, demonstrating that other viral proteins were not required for this function. Treatment of NSP5-expressing cells with staurosporine, a broad-range protein kinase inhibitor, had only a limited negative effect on the phosphorylation of the viral polypeptide. Staurosporine did not inhibit autophosphorylation of NSP5 in vitro. Together, the data support the idea that NSP5 has an autophosphorylation activity that is positively regulated by addition of phosphate residues at some positions.

Animals↗
PubMed1998

Organization of the caudal rhombencephalic alar plate of the ribbed newt Pleurodeles waltl: evidence for the presence of dorsal column and lateral cervical nuclei.

As part of a recent program on the evolution of somatosensory systems in vertebrates, the cytoarchitecture, chemoarchitecture, and fiber connections of the caudal rhombencephalic alar plate were studied in the ribbed newt, Pleurodeles waltl. This part of the brain stem includes ill-defined dorsal column and lateral cervical nuclei. A cytoarchitectonic analysis revealed that the caudal medullary alar plate consists of an inner and an outer cell layer. The dorsomedial part of the outer cell layer at the obex level contains the dorsal column nucleus (DCN), whereas its ventrolateral part constitutes the lateral cervical nucleus (LCN). NADPH-diaphorase histochemistry and calbindin D-28k immunohistochemistry clearly delineate the main components of the compact inner cell layer, i.e. the nucleus of the solitary tract dorsally and the nucleus of the descending trigeminal tract ventrally. Neither NADPH-diaphorase-labeled nor calbindin D-28k positive neurons were observed in the DCN and LCN. With anterograde and retrograde tracing, the DCN and LCN were further delineated. Labeling of ascending dorsal root projections showed that the dorsal column and the DCN are somatotopically arranged: lumbar primary afferent fibers terminate on medial DCN neurons, whereas cervical primary afferent fibers terminate on lateral DCN neurons. The LCN is densely innervated by the dorsolateral funiculus. Retrograde tracing showed extensive, predominantly contralateral projections of both the DCN and LCN to the torus semicircularis and the ventral thalamus. These data show that even in the poorly segregated caudal rhombencephalic alar plate of urodeles a DCN and LCN can be distinguished with afferent and efferent projections comparable to those in anurans and other terrestrial vertebrates.

Animals↗
PubMed1998

Modifications in the distribution of met-enkephalin in the pons of the cat, following the intravenous administration of clonidine: an immunocytochemical experimental study.

The distribution of met-enkephalin in the cat and its modifications following the stimulation by intravenous clonidine, was studied with indirect immunocytochemical techniques. We observed a decrease in the immunoreactivity of met-enkephalin following the administration of clonidine, relative to the controls, in the following structures: locus coeruleus, nucleus cuneformis, formatio reticularis, nucleus gigantocellularis, nucleus reticularis lateralis, nucleus reticularis, nucleus reticularis parvocellularis, nucleus sensorius superior n. trigemini, nucleus raphes, substantia grisea periventricularis, nucleus eminentiae teretis, colliculus inferior, nucleus motorius n. trigemini, nucleus tracto spinalis n. trigemini, tractus spinalis n. trigemini and nucleus tracto mesencephalici n. trigemini. These experimental observations link the immunoreactivity changes to the structures that are associated with the direct action of clonidine and conclude that the pars metencephalinergicus of the efferent pontine pathway of pain is in morpho-functional relationship with the analgesia produced by clonidine; an analgesic of an endogenous opiate character.

Adrenergic alpha-Agonists↗
PubMed1998

Modifications in the distribution of met-enkephalin in the cat spinal cord after administration of clonidine. An immunocytochemical study.

We have studied the modifications in the distribution of methionine-enkephalin in the cat spinal cord after intravenous or intrathecal administration of clonidine by using an immunocytochemical technique. In animals not treated with the substance, a very high density of immunoreactive fibers was found in layers I and II; a high density in the dorso-lateral funiculus and in the reticular formation; a moderate density in layers III, IV and V; and a low density in layer VI. However, after intravenous or intrathecal administration of clonidine a decrease in fibers containing met-enkephalin was observed in layers I and II (high or moderate density), the dorso-lateral funiculus, and the reticular formation (moderate or low density), and in layers IV and V (low or very low density). In all cases, the decrease in the immunoreactivity was more marked when clonidine was administered intrathecally. Our results suggest that clonidine induces the release of metenkephalin in the spinal cord. They further suggest that the opioid peptide released could be involved in the control of nociceptive transmission by inhibiting the release of neurotransmitters (e.g., substance P). In summary, our study shows that clonidine could be involved in antinociceptive mechanisms in the cat spinal cord.

Analgesics↗
PubMed1998

[Intestinal obstruction and necrotizing thyroiditis secondary to Pneumocystis carinii infection in a seropositive hemophiliac patient seropositive for human immunodeficiency virus].

We report a case of bowel infection by Pneumocystis carinii (PC) that presented as an acute obstruction accompanied by intestinal hemorrhage (melena) in a HIV seropositive hemophilic patient. Laparotomy followed by resection of two plaque-like jejunal tumors was performed, and intravenous therapy with pentamidine was initiated. No other organ was found to be affected by PC (not even the lung), with the exception of the thyroid gland. To our knowledge, this is the first reported case in which acute intestinal obstruction was the presenting symptom of extrapulmonary pneumocystosis.

AIDS-Related Opportunistic Infections↗
PubMed1998

Organization of an umbilical cord blood transplant program.

The development of the human umbilical cord blood transplants with hematopoietic repopulating cells has enabled some problems associated with bone marrow transplants to be solved. Frozen umbilical cord blood banks should facilitate the finding of suitable stem cell donors. However, further experience is necessary to develop the optimal method for collection, separation, storage and cryopreservation of umbilical cord blood. We report our experience in the organization of a Cord Blood Bank.

Blood Banks↗