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Biomedical subjects

J Alvarez

Publications and source records attributed to J Alvarez.

At least 163 records · Page 9Linked to original sources
PubMed1995

Cold saline is more effective than room temperature saline in inducing paresthesia during axillary block.

Confirmation of the perivascular position of the needle by the injection of cold saline may be helpful to the perivascular technique, since the elicitation of a paresthesia indicates the correct positioning of the needle. In this prospective, randomized study of 48 patients, we found a 100% incidence of successful block with saline at 8-11 degrees C compared to 75% in a control group with saline at room temperature. The paresthesia induced by cold saline appears to be due to thermic stimulation and not to mechanical nerve compression by the saline entering the axillary space. A more frequent rate of correct positioning of the needle was found in the group with cold saline.

Axilla↗
PubMed1995

DNA microsatellite analysis of families with autosomal dominant polycystic kidney disease types 1 and 2: evaluation of clinical heterogeneity between both forms of the disease.

We studied 17 large families affected by adult dominant polycystic kidney disease (ADPKD). Ultrasonographic analysis was performed on all the family members. DNA microsatellite markers closely linked to PKD1 on 16p13.3 were analysed, and linkage of the disease to this locus was determined. Families showing a negative linkage value were evaluated for linkage to the PKD2 locus on 4q. Five of the 17 families showed negative linkage for the 16p13.3 markers. In these families significant linkage to 4q was obtained. Renal cysts developed at an earlier age in PKD1 mutation carriers, and end stage renal failure occurred at an older age in people affected with PKD2. Analysis of large families with ADPKD in a Spanish population indicates that this is a genetically heterogeneous disorder, but mutations at only two loci are responsible for the development of the disease in most if not all the families. Clinicopathological differences between both forms of the disease occur, with subjects with ADPKD2 having a better prognosis than those with mutations at PKD1.

Adolescent↗
PubMed1995

[Obstetric anesthesia-analgesia in Spain. A review of its historic evolution during the second half of the past century].

To examine the historical development of obstetric anesthesia in Spain during the second half of the nineteenth century. Research was based on in-depth analysis of accounts of anesthesia during the period covered, mainly from original sources, using established methods for studying the history of medicine. We collected a great deal of documentary evidence, much of it unpublished and of clear historical value for tracing the history of obstetric anesthesia in Spain and identifying the main factors that have influenced it. We emphasize that controversy limited to a large extent the use of anesthesia in obstetrics. The controversy seems to have been fed by physicians' uneasiness with anesthesia as well as by certain prejudices of a religious or moral nature that are deeply rooted in Spanish society.

Analgesia, Obstetrical↗
PubMed1995

Comparison of maintenance and recovery characteristics of sevoflurane-nitrous oxide and enflurane-nitrous oxide anaesthesia.

We compared maintenance of anaesthesia and recovery using either sevoflurane or enflurane anaesthesia in ASA I-III patients undergoing surgery with an anticipated minimum duration of 3 h. Serum fluoride concentrations were also measured to assess the potential for renal toxicity. After induction of anaesthesia with thiopentone, patients received, for maintenance, either 1.5% end-tidal sevoflurane (0.73 MAC) with N2O 58% (0.58 MAC) (n = 40) or 1.2% end-tidal enflurane (0.7 MAC) with N2O 57% (0.57 MAC) (n = 40). Other drugs administered during anaesthesia were similar in all groups. Haemodynamic measurements, recovery times, as well as post-operative nausea and vomiting were comparable in both groups. The mean peak plasma inorganic fluoride ion concentrations were reached 4 h after operation in both groups (27.7 microM L-1 for sevoflurane and 16.75 microM L-1 for enflurane, P < 0.05) declining 50% within 24 h in both groups. A positive correlation (P < 0.05) was found between anaesthetic exposure (MAC h) and fluoride concentrations in the two groups. Sevoflurane anaesthesia resulted in similar haemodynamic stability, recovery times and post-operative side effects as enflurane anaesthesia, but produced significantly greater serum fluoride levels.

Analgesics, Opioid↗
PubMed1995

[Investigation of an outbreak of water-borne typhoid fever in Catalonia in 1994].

BACKGROUND: Typhoid fever incidence in Spain, and particularly in Catalonia has decreased significantly since 1985. Water borne outbreaks can affect large numbers of people. These two reasons make specially interesting to study all suspected typhoid fever outbreaks, like the one that happened in March 1994 in Bages county (Barcelona). METHODS: Epidemiological questionnaires were conducted to investigate the origin of the outbreak, the presence of related cases in the same area, and the household contacts of cases S. typhi isolates were characterized by serotyping, biotyping, phage-typing, ribotyping and pulsed field gel electrophoresis analysis of DNA. RESULTS: Nine cases were identified. All cases were treated with antibiotics, with clinical success. There were not secondary cases. The possible origin was a drinking fountain. All the strains had the same epidemiological marker patterns. CONCLUSIONS: Breaking of the sewer pipes near to the drinking fountain was probably the origin of the contamination. It can be concluded the importance of keeping a good epidemiological control system to investigate and prevent outbreaks. It is also important to control the drinking fountains to prevent its contamination. Finally it is necessary to highlight the utility of epidemiological markers to fully characterized the involved strains.

Adolescent↗
PubMed1994

Inhibition by insoluble immune complexes of both capacitative Ca2+ entry and Ca2+ mobilization by chemotactic agonists in human neutrophils.

Insoluble immune complexes (IIC) stimulate human neutrophils by binding to their FcR. It is known that they are able to release Ca2+ from intracellular stores but they induce little Ca2+ entry from the extracellular medium, a dissociation that cannot be explained within the framework of the capacitative model for Ca2+ entry, which is well established for these cells. We show here that IIC induce a strong and long-lasting inhibition of the Ca2+ pathway activated by emptying the Ca2+ stores (capacitative Ca2+ entry), which develops simultaneously with the activation of Ca2+ release from intracellular stores. This inhibition strongly resembles that previously described effected by FMLP and by phorbol dibutyrate, which seems to be mediated by phosphorylation. Inhibition by IIC, however, differs from that induced by FMLP and phorboldibutyrate in its lack of sensitivity to cytosolic-free calcium concentration and in its different sensitivity to the protein kinase inhibitors staurosporin and chelerythrine. It was also insensitive to the protein tyrosine kinase inhibitors genistein and herbimycin A. We also show that IIC inhibit Ca2+ mobilization induced by other agonists and that this inhibition is potentiated by the protein phosphatase inhibitor calyculin A. Our results therefore suggest that binding of IIC to the FcR activates a protein phosphorylation mechanism leading to a long-lasting inhibition of both capacitative Ca2+ entry and Ca2+ mobilization induced by other agonists such as FMLP, platelet-activating factor, or leukotriene B4.

Antigen-Antibody Complex↗
PubMed1994

Activation by chemotactic peptide of a receptor-operated Ca2+ entry pathway in differentiated HL60 cells.

N-Formyl-methionyl-leucyl-phenylalanine (fMLP) is able to accelerate Ca2+ entry into differentiated HL60 cells by a rather indirect mechanism consisting of the opening of a plasma membrane pathway activated by the emptying of the intracellular Ca2+ stores caused by the agonist. This Ca2+ pathway can also be fully activated by Ca2+ store depletion with thapsigargin. We show here that, in addition to this store-operated Ca2+ entry pathway (SOCP), fMLP is able to activate another receptor-operated Ca2+ pathway in thapsigargin-treated HL60 cells differentiated for 24 h with dimethyl sulfoxide. Activation by fMLP was produced even in cells with fully empty Ca2+ stores. It started 30 s after fMLP addition, was maximal after 2 min and then disappeared within 5 min. This pathway was similar to SOCP in that it allowed passage of Mn2+ and Ba2+ and was antagonized by Ni2+ and by cytochrome P-450 inhibitors. fMLP is also able to inhibit SOCP by a mechanism involving protein phosphorylation. Both the fMLP-induced activation of Ca2+ entry and the inhibition of SOCP were prevented by pretreatment with pertussis toxin. However, the first appeared earlier than the last along differentiation of HL60 cells. This suggests that the inhibition of SOCP requires not only the development of fMLP receptors but also an additional component placed distally to the G protein in the transduction mechanism.

Calcium↗
PubMed1994

Lethal Pallister-Killian syndrome: phenotypic similarity with Fryns syndrome.

The Pallister-Killian syndrome is a sporadic multiple congenital anomaly syndrome characterized by "coarse" face, profound mental retardation, and epilepsy. Chromosomes of peripheral lymphocytes are usually normal, but tissue cultures show varying degrees of mosaicism for isochromosome 12p. In babies who die neonatally of severe malformations, including diaphragmatic hernia, and who also have a "coarse" face, acral hypoplasia, and other internal anomalies, Fryns syndrome is more likely to be suspected than Pallister-Killian syndrome, especially if karyotyping is unavailable or if peripheral lymphocytes have a normal chromosome constitution. An initial diagnosis of Fryns syndrome had to be modified in 3 successive newborn infants since chromosome analysis or in situ hybridization with a chromosome 12 probe on kidney tissue demonstrated the mosaic aneuploidy characteristic of Pallister-Killian syndrome. These 3 patients confirm that a similar pattern of malformations can be present in both conditions at birth. It consists of "coarse" face, acral hypoplasia, diaphragmatic hernia, and other defects. Newborn infants who present this phenotype, but lack a conclusively normal chromosome test, may not have Fryns syndrome. A diagnosis of Fryns syndrome should be made carefully to avoid the risk of inappropriate genetic counseling.

Abnormalities, Multiple↗
PubMed1994

Phosphorylation down-regulates the store-operated Ca2+ entry pathway of human neutrophils.

We have reported previously that the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (fMLP) inhibits transiently Ca2+ entry through the plasma membrane Ca2+ pathway activated by emptying the intracellular Ca2+ stores (Montero, M., García-Sancho, J., and Alvarez, J. (1993) J. Biol. Chem. 268, 13055-13061). We show here that calyculin A and okadaic acid, inhibitors of protein phosphatases 1 and 2A, prevent the spontaneous reversion of the fMLP-induced inhibition of the entry of Ca2+ and Mn2+ (used as a Ca2+ surrogate), leading to a permanently inhibited Ca2+ entry pathway. At high concentrations or long incubation times the phosphatase inhibitors were even able to inhibit the store-operated Ca2+ entry pathway (SOCP) in the absence of fMLP. Inhibition of SOCP by phorbol dibutyrate, which is not reversible, was not modified by phosphatase inhibitors. These results provide additional support for the view that fMLP inhibits SOCP through phosphorylation of either the SOCP protein or a regulatory protein and indicate that dephosphorylation mediated by protein phosphatases 1 and/or 2A restores the activity of SOCP after inhibition by fMLP. The time course of the inhibition of SOCP by fMLP was similar to the one reported previously for the transient fMLP-induced phosphorylation of a 47-kDa protein involved in the generation of respiratory burst, which was similarly affected by the phosphatase inhibitors.

Calcium↗
PubMed1994

Effects of extremely-low-frequency electromagnetic fields on ion transport in several mammalian cells.

We have investigated the effects of sinusoidal electromagnetic fields (EMF) on ion transport (Ca2+, Na+, K+, and H+) in several cell types (red blood cells, thymocytes, Ehrlich ascites tumor cells, and HL60 and U937 human leukemia cells). The effects on the uptake of radioactive tracers as well as on the cytosolic Ca2+ concentration ([Ca2+]i), the intracellular pH (pHi), and the transmembrane potentsial (TMP) were studied. Exposure to EMF at 50 Hz and 100-2000 microT (rms) had no significant effects on any of these parameters. Exposure to EMF of 20-1200 microT (rms) at the estimated cyclotron magnetic resonance frequencies for the respective ions had no significant effects except for a 12-32% increase of the uptake of 42K within a window at 14.5-15.5 Hz and 100-200 microT (rms), which was found in U937 and Ehrlich cells but not in the other cell types.

Animals↗
PubMed1994

Saliva electrolytes as a useful tool for anaerobic threshold determination.

The purpose of the present study was to determine the anaerobic threshold by analysis of changes in saliva composition during an incremental exercise test on a cycle ergometer. Thirteen healthy males underwent a submaximal test with an initial load of 50 W and load increases of 50 W per 3 min, until capillary blood lactate exceeded 4 mmol.l-1. A maximal test for maximum O2 uptake (VO2max) determination (initial load of 100 W and load increases of 50 W per 2 min) was also performed. Saliva and blood samples were obtained only in the submaximal test. Saliva threshold (Thsa) was defined as the point at which the first increase in either Cl- or Na+ occurred. Catecholamine threshold (Thca) was defined as the point at which a nonlinear increase occurred in either adrenaline or noradrenaline. The lactate (Thla) and ventilatory (Thve) thresholds were determined according to published criteria. No significant differences were found between Thsa values and the other methods of threshold determination. A high correlation was found between Thsa and Thla (r = 0.82, P < 0.01), and Thsa and Thca (r = 0.75, P < 0.05). These results support the validity of Thsa as a new method for noninvasive determination of the anaerobic threshold.

Adult↗
PubMed1994

Anti-immunoglobulin antibodies in children with Schönlein-Henoch syndrome. Absence of serum anti-IgA antibodies.

Circulating immune complexes (CIC) that simultaneously contain IgG and IgA are frequently found in IgA nephropathy (IgA-N) and the Schönlein-Henoch syndrome (SHS). The presence of anti-immunoglobulin antibodies (IgA anti-IgG and IgG anti-IgA) was studied by ELISA in the serum of 39 children with SHS and compared to 30 normal children. The mean level of IgG anti-IgA antibodies (240 +/- 104 u/ml) in SHS patients was similar to control values (251 +/- 85 u/ml); the IgA anti-IgG antibodies were increased, although only the antibodies against Fc fraction of IgG were elevated (185 +/- 71 u/ml in patients vs 127 +/- 24 mu/ml in controls, P < 0.0001) without a significant increase of IgA anti-IgGFab antibodies (141 +/- 54 mu/ml vs. 137 +/- 25 u/ml); 16/39 (41%) of the patients had increased levels of IgA anti-IgGFc and 6 of these had also high IgA anti-IgGFab. None of these patients had high IgA anti-IgGFab antibodies without simultaneous augmentation of IgA anti-IgGFc. Only 3/39 (7.7%) of SHS patients showed high levels of IgG anti-IgA antibodies. The correlation of IgA anti-IgGFc antibodies with IgA anti-IgGFab was very strong (P < 0.0001) but lower with IgG anti-IgA antibodies (P < 0.002). In addition, 8/39 children had renal involvement, nevertheless in these patients the findings were quite similar, with a non-significant elevation of IgA anti-IgGF ab antibodies. These results show that the IgA anti-IgG antibodies are more frequently increased than IgG anti-IgA antibodies in the SHS; moreover they are mainly directed against Fc fraction and are IgA-FR isotype. Our findings suggest that the CIC in SHS are likely formed by the reaction of IgA anti-bodies against IgG and not vice versa.

Antibodies, Anti-Idiotypic↗
PubMed1994

Blood markers in Alzheimer disease: subnormal acetylcholinesterase and butyrylcholinesterase in lymphocytes and erythrocytes.

In patients with the clinical diagnosis of Alzheimer disease (AD), we searched for systemic changes in components of the blood as a diagnostic tool. The acetylcholine-related enzymes acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were measured in plasma, erythrocytes, platelets and lymphocytes. Results did not show a general effect; notwithstanding, specific cell types presented alterations either in AChE or BuChE but not in both enzymatic activities. In AD patients, AChE of lymphocytes was reduced by 60% compared with the age-matched controls. However, when patients were divided, the sporadic but not the familial subgroup exhibited a significant reduction. In erythrocytes the BuChE activity was reduced by 45% in sporadic AD. The molecular forms of the lymphocyte AChE were characterized by velocity sedimentation. Both globular forms were subnormal, more so the tetrameric G4 AChE form than the G2 form.

Acetylcholinesterase↗
PubMed1994

Pulmonary carcinoma metastatic to the larynx.

Metastases to the larynx from distant primaries are rare. We report a case of a pulmonary epidermoid carcinoma metastatic to the larynx that simulated a primary cancer. A review of the literature showed nine previously reported cases of pulmonary metastases to the larynx--only two of them were epidermoid carcinomas. Treatment of a secondary lesion in the larynx is justified only when other organs have not been affected. The diagnostic and therapeutic considerations of this condition are discussed.

Carcinoma, Squamous Cell↗