126
|
Fernández N, Martínez MA, Monge L, García-Villalón AL, Diéguez G. Adrenergic vasoconstrictor activity in the cerebral circulation after inhibition of nitric oxide synthesis in conscious goats. Auton Neurosci 2001; 89:16-23. [PMID: 11474642 DOI: 10.1016/s1566-0702(01)00244-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The interaction between nitric oxide (NO) and adrenergic activity in the cerebral circulation was studied using conscious goats, where blood flow to one brain hemisphere (cerebral blood flow) was electromagnetically measured, and the effects of phentolamine and hexamethonium on cerebrovascular resistance were evaluated before (control) and after inhibition of NO synthesis with NW-nitro-L-arginine methyl ester (L-NAME). L-NAME (12 goats, 40 mg kg(-1) administered i.v.) reduced cerebral blood flow from 62 +/- 3 to 44 +/- 2 ml min(-1), increased mean systemic arterial pressure from 100 +/- 3 to 126 +/- 4 mm Hg, decreased heart rate from 79 +/- 5 to 50 +/- 4 beats min(-1) and increased cerebrovascular resistance from 1.63 +/- 0.08 to 2.91 +/- 0.016 mm Hg ml(-1)min(-1) (all P < 0.01). These hemodynamic variables normalized 48-72 h after L-NAME administration. Phentolamine (six goats, 1 mg), injected into the cerebral circulation. increased cerebral blood flow without changing systenic arterial pressure, but its cerebrovascular effects were augmented for about 24 h after L-NAME. The decrements in cerebrovascular resistance induced by phentolamine, in mm Hg ml(-1) min(-1), were: under control, 0.42 +/- 0.05; immediately after L-NAME, 1.38 +/- 0.09 (P < 0.01 compared with control); by about 24 h after L-NAME, 0.71 +/- 0.09 (P < 0.05 compared with control); and by about 48 h after L-NAME, 0.40 +/- 0.07 (P > 0.05 compared with control). Hexamethonium (six goats, 0.5-1 mg kg(-1) min(-1) i.v.) decreased mean systemic arterial pressure to about 75 mm Hg and caused tachycardia similarly before and after L-NAME, but the decrements in cerebrovascular resistance were augmented for about 24 h after L-NAME. The decrements in cerebrovascular resistance induced by hexamethonium, in mm Hg ml(-1).min(-1), were: under control. 0.61 +/- 0.09, immediately after L-NAME, 1.33 +/- 0.16 (P < 0.01 compared with control); by about 24 h after L-NAME, 1.18 +/- 0.10 (P < 0.01 compared with control): and by about 48 h after L-NAME, 0.99 +/- 0.10 (P > 0.05 compared with control). Therefore, these results suggest that adrenergic vasoconstrictor tone in cerebral vasculature may be augmented after inhibition of NO synthesis, and that this increment may contribute to the reduction of cerebral blood flow after inhibition of NO formation.
Collapse
|
127
|
Torrelo A, Marrero MD, Mediero IG, Martínez MA, Zambrano A. Progressive macular leucoderma in a patient with congenital ichthyosiform erythroderma. Br J Dermatol 2001; 144:1280-2. [PMID: 11422068 DOI: 10.1046/j.1365-2133.2001.04259.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
128
|
Rosenblüt A, Santolaya ME, González P, Corbalán V, Avendanõ LF, Martínez MA, Hormazabal JC. Bacterial and viral etiology of acute otitis media in Chilean children. Pediatr Infect Dis J 2001; 20:501-7. [PMID: 11368107 DOI: 10.1097/00006454-200105000-00006] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Acute otitis media (AOM) is a main cause for antimicrobial prescription in Latin America. Pathogen diversity in different geographic regions underscores the need for updated knowledge on AOM microbiology. AIM To prospectively determine the role of bacteria and viruses in Chilean children with AOM. METHODS Between July, 1998, and June, 1999, children >3 months with a presumptive diagnosis of AOM were referred to the study ear, nose and throat physician. Middle ear fluid and nasopharyngeal aspirates were obtained from children with confirmed AOM and processed for common bacteria, Mycoplasma pneumoniae, Chlamydia pneumoniae and viruses. Antimicrobial susceptibility patterns and serotypes of Streptococcus pneumoniae strains were determined. RESULTS An ear, nose and throat physician confirmed diagnoses for 222 (42%) of 529 children referred with diagnosis of AOM, and 170 children met eligibility criteria for the study. One or more pathogens were detected in 140 of 170 (82%) children. Predominant bacteria were S. pneumoniae (37%), Haemophilus influenzae (24%) and Streptococcus pyogenes (13%). M. catarrhalis was detected in 2 children, C. pneumoniae was found in 1 and M. pneumoniae was not detected. Viruses were detected in 22 children (13%) from nasopharyngeal aspirates, and in 6 of them the same virus was detected in middle ear fluid. Penicillin-resistant (intermediate and high) S. pneumoniae represented 40% of isolates and 10% of H. influenzae were beta-lactamase producers. All 10 penicillin-resistant S. pneumoniae strains were resistant to cefuroxime. Eighteen S. pneumoniae serotypes were detected and 19F was associated with high level penicillin resistance. CONCLUSION This study can impact local management of AOM, and it should encourage continuous surveillance of AOM microbiology in Chile and other developing countries.
Collapse
|
129
|
Fernández N, Martínez MA, García-Villalón AL, Monge L, Diéguez G. Cerebral vasoconstriction produced by vasopressin in conscious goats: role of vasopressin V(1) and V(2) receptors and nitric oxide. Br J Pharmacol 2001; 132:1837-44. [PMID: 11309256 PMCID: PMC1572748 DOI: 10.1038/sj.bjp.0704034] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
To examine the role of vasopressin V(1) and V(2) receptors, nitric oxide and prostanoids in the cerebrovascular effects of arginine vasopressin, cerebral blood flow was electromagnetically measured in awake goats. In 16 animals, vasopressin (0.03 - 1 microg), injected into the cerebral circulation, caused increments of resting cerebrovascular resistance which ranged from 18% (0.03 microg, P<0.01) to 79% (1 microg, P<0.01). Desmopressin (0.03 - 1 microg, four goats) did not affect significantly cerebrovascular resistance. The cerebrovascular resistance increases by vasopressin were reduced significantly by the antagonist for vasopressin V(1) receptors d(CH(2))(5)Tyr(Me)-AVP in a rate depending way (five (six goats) and 15 (four goats) microg min(-1)), and by the mixed antagonist for vasopressin V(1) and V(2) receptors desGly-d(CH(2))(5)-D-Tyr(Et)Val-AVP (5 microg min(-1), four goats), and they were not significantly affected by the antagonist for vasopressin V(2) receptors d(CH(2))(5), D-Ile(2), Ile(4)-AVP (5 microg min(-1), four goats). The inhibitor of nitric oxide synthesis N(w)-nitro-L-arginine methyl ester (L-NAME, 47 mg kg(-1) i.v., five goats) augmented cerebrovascular resistance by 130% (P<0.01), and for 24 h after this treatment the cerebrovascular effects of vasopressin were potentiated. The inhibitor of cyclo-oxygenase meclofenamate (6 mg kg(-1) i.v., five goats) did not modify significantly resting haemodynamic variables measured or the cerebrovascular effects of vasopressin. Therefore, the vasopressin-induced cerebral vasoconstriction may be mediated by vasopressin V(1) receptors, without involvement of vasopressin V(2) receptors, and may be modulated by nitric oxide but not by prostanoids.
Collapse
|
130
|
Ibáñez A, Clotet B, Martínez MA. Absence of genetic diversity reduction in the HIV-1 integrated proviral LTR sequence population during successful combination therapy. Virology 2001; 282:1-5. [PMID: 11259184 DOI: 10.1006/viro.2000.0840] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We report the integrated proviral LTR sequence variation in four patients on highly active antiretroviral therapy (HAART). Integrated proviral fragments of LTR taken from four time points were PCR amplified from PBMCs and 10 to 12 individual clones were sequenced for each time point. Intrasample genetic distances and phylogenetic reconstruction of all LTR sequences demonstrated that 1-2 years of successful HAART did not significantly reduce the genetic repertoire of the integrated reservoir of HIV-1.
Collapse
|
131
|
Font R, Sabater MC, Martínez MA. Leaching of toluene-neoprene adhesive wastes. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2001; 35:977-983. [PMID: 11351545 DOI: 10.1021/es000134c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
This work consists of the study of the extraction of solvent (toluene) from a polymeric (neoprene) substrate during a leaching process. Total organic carbon (TOC) is the main contaminant parameter in the leaching of these systems due to the solution of the toluene and the dispersion of the polymer. The toxicity of the extracts was measured with a Microtox equipment, using Photobacteria phosphoreum, deducing that the toxicity of the extracts is low due to the low solubility of toluene but that the toxicity of toluene is high. On the basis of the experimental results, the amount of toluene diffused vs time in plane sheet systems was studied. A kinetic model has been developed considering two stages: In the first stage, the toluene diffuses into the system across the neoprene chains at a constant rate, not depending on the initial toluene concentration. This fact is explained by considering that there is a constant difference of the toluene concentration between the interface with the water and the inner part of the sample. In the second stage, the dispersion of the polymer with the corresponding amount of toluene takes place. The diffusion of toluene in the leaching process is compared and analyzed considering the diffusion of toluene in a desorption process in air so that the difference of toluene concentration between the interface and the interior can be estimated. A mathematical model is also proposed for considering the leaching process in other operating conditions.
Collapse
|
132
|
Fernández-Vázquez A, Rodríguez-Peralto JL, Martínez MA, Platón EM, Algara P, Camacho FI, López-Ríos F, Zarco C, Sánchez-Yus E, Fresno MF, Barthe L, Aliaga A, Fraga M, Forteza J, Oliva H, Piris MA. Primary cutaneous large B-cell lymphoma: the relation between morphology, clinical presentation, immunohistochemical markers, and survival. Am J Surg Pathol 2001; 25:307-15. [PMID: 11224600 DOI: 10.1097/00000478-200103000-00004] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The histogenesis, morphology, immunophenotype, and clinical behavior of cutaneous large B-cell lymphomas (CLBCL) are largely a matter of controversy. We performed an investigation to determine whether CLBCL have features that differentiate them from other large B-cell lymphomas and whether CLBCL is itself a heterogeneous group. To this end, we reviewed the main characteristics of a series of 32 cases of LBCL found in the skin. We reviewed the clinical findings and paraffin sections of the tumors from these 32 patients. The immunohistochemical study performed included p53, MIB1, Bcl2, Bcl6, and CD10 markers. We carried out statistical analysis of these data (univariate and multivariate), seeking an association between the features of the tumors and clinical outcome, as defined by failure-free survival time. Only one patient died as a consequence of the lymphoma. Nevertheless, the accumulated probability of survival without failure at 48 months was 0.46. The number, type, and localization of the lesions were not associated with variations in either survival or failure-free survival. The expression of p53 was negative in this group of CLBCL, whereas Bcl-2 expression or localization in the lower leg did not relate to any other significant feature. Histologic examination of the cases disclosed three different groups: Grade III follicular lymphomas (FLs), monomorphous large B-cell lymphomas (LBCL type I), and LBCL with an admixed component of small B-lymphocytes (LBCL type II). Grade III FL (11 cases) tended to be found in the head and neck and showed CD10 expression in a majority of cases. A higher probability of lymph node relapses was associated with cases located in the head and neck and with CD10+ tumors. Cutaneous large B-cell lymphomas are indolent tumors, but follow an insidious course. Our data support the interpretation that CLBCL is a heterogeneous condition; comprises some LBCL derived from CD10+ germinal center cells which manifests more frequently as tumors in the head and neck region, with an increased probability of relapse in lymph nodes [1] and has some distinctive morphologic features. The existence of a component of small B-cells within the other CLBCL could lend support to the theory that some of these tumors, more than arise de novo, may have originated in preexistent small B-cell lymphomas, but no firm evidence of this is provided in this study.
Collapse
MESH Headings
- Adult
- Aged
- Aged, 80 and over
- B-Lymphocytes/pathology
- Biomarkers, Tumor/analysis
- Combined Modality Therapy
- Disease-Free Survival
- Female
- Follow-Up Studies
- Humans
- Immunohistochemistry
- Immunophenotyping
- Lymphoma, B-Cell/chemistry
- Lymphoma, B-Cell/mortality
- Lymphoma, B-Cell/pathology
- Lymphoma, B-Cell/therapy
- Lymphoma, Large B-Cell, Diffuse/chemistry
- Lymphoma, Large B-Cell, Diffuse/mortality
- Lymphoma, Large B-Cell, Diffuse/pathology
- Lymphoma, Large B-Cell, Diffuse/therapy
- Male
- Middle Aged
- Neoplasm Proteins/analysis
- Neoplasm Staging
- Skin Neoplasms/chemistry
- Skin Neoplasms/mortality
- Skin Neoplasms/pathology
- Skin Neoplasms/therapy
- Survival Rate
Collapse
|
133
|
Carvajal-Millán E, Carvallo T, Orozco JA, Martínez MA, Tapia I, Guerrero VM, Rascón-Chu A, Llamas J, Gardea AA. Polyphenol oxidase activity, color changes, and dehydration in table grape rachis during development and storage as affected by n-(2-chloro-4-pyridyl)-n-phenylurea. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2001; 49:946-951. [PMID: 11262054 DOI: 10.1021/jf000856n] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Flame Seedless grapes were sprayed with N-(2-chloro-4-pyridyl)-N-phenylurea (CPPU) at 0, 2.5, and 5.0 ppm to develop rachis resistant to browning and dehydration. Rachis polyphenol oxidase (PPO) activity was determined during cluster development. Cluster components were weighed at commercial (CM), and physiological maturity (PM). PPO activity, rachis color changes (L and a), and cluster weight loss were evaluated at 0 degrees C for 8, 16, 32, and 56 days. CPPU-treated rachis had a decrease of 36% in PPO activity and a week delay in peak activity. At PM, dry weight of CPPU-treated rachis increased by 3 g. Postharvest rachis PPO activity declined with CPPU application, and color changes followed the same pattern for CM and PM. After 32 days of storage, L and a in lateral branches were significantly superior in CPPU treatments. Weight losses below 2.1% were significantly lowest in CPPU-treated clusters for 16 days of storage regardless of cluster maturity.
Collapse
|
134
|
Martínez MA, Moreno A, Aguirre de Cárcer A, Cabrera R, Rocha R, Torre A, Nevado A, Ramos T, Neri J, Antón G, Miranda I, Fernández P, Rodríguez E, Miquel A, Martínez JL, Rodríguez M, Eisman C, Puig JG. Frequency and determinants of microalbuminuria in mild hypertension: a primary-care-based study. J Hypertens 2001; 19:319-26. [PMID: 11212976 DOI: 10.1097/00004872-200102000-00020] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To evaluate the frequency of microalbuminuria and its relationship with several risk factors and left ventricular mass in a population of mildly hypertensive subjects attended in a primary-care setting. DESIGN Cross-sectional study. SETTING Eight primary-care centres. PATIENTS Two hundred and twenty-three non-diabetic patients recently diagnosed with mild hypertension were included in the study. None of them had clinical evidence of target-organ damage or had received prior antihypertensive treatment. INTERVENTIONS Subjects included in the study underwent clinical interview, measurement of blood pressure (BP) on three visits, blood analysis, measurement of albumin by immunonephelometry in three overnight urine collections, 24 h BP monitoring and M-mode and Doppler echocardiography. MAIN OUTCOME MEASURES Tobacco habit, clinic BP, body mass index, serum lipids and uric acid, glycaemia, urinary albumin excretion (UAE), ambulatory BP and left ventricular mass index. RESULTS The frequency of microalbuminuria was 7.2%. Microalbuminuric patients were more likely to be men and to be characterized by higher ambulatory BP, body mass index and uric acid levels. Regression analysis demonstrated that male sex and 24 h systolic BP were determinants of UAE. Patients with white-coat hypertension showed lower UAE than did subjects with sustained hypertension. Although a certain relationship between UAE and left ventricular mass index was found, these variables were not significantly correlated. CONCLUSIONS A low proportion of mildly hypertensive patients attended in a primary care setting are microalbuminuric. In this population, UAE is an expression of BP values over 24 h and correlates with several risk factors.
Collapse
|
135
|
Abstract
The discovery of the adipocyte-produced hormone leptin has changed the field of obesity research and our understanding of energy homeostasis. It is now accepted that leptin is the afferent loop informing the hypothalamus about the states of fat stores, with hypothalamic efferents regulating appetite and energy expenditure. I addition, leptin has a role as a metabolic adaptator in overweight and fasting states. New and previously unsuspected neuroendocrine roles have emerged for leptin. Leptin participates in the expression of CRH in the hypothalamus, interacts at the adrenal level with ACTH, and is regulated by glucocorticoids. Since leptin and cortisol show an inverse circadian rhythm, it has suggested that a regulatory feedback is present. However glucocorticoids appears to play a modulatory, but not essential roles in generating leptin diurnal rhythm. Glucocortiocids act directly on the adipose tissue and increase leptin synthesis and secretion in humans. Leptin levels are markedly increased in Cushing's syndrome patients and in other pseudo-Cushing's syndrome states. Glucocorticoids appears to act as a key modulator of body weight and food intake, promoting leptin secretion by adipocytes, limiting central leptin induced effects and favoring those of the NPY. Furthermore the modulatory role of glucocorticoids could be altered in obesity, but the precise mode of action remains to be established. The relevance of this finding merits further studies.
Collapse
|
136
|
Mas A, Parera M, Briones C, Soriano V, Martínez MA, Domingo E, Menéndez-Arias L. Role of a dipeptide insertion between codons 69 and 70 of HIV-1 reverse transcriptase in the mechanism of AZT resistance. EMBO J 2000; 19:5752-61. [PMID: 11060026 PMCID: PMC305792 DOI: 10.1093/emboj/19.21.5752] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
The 3'-azido-3'-deoxythymidine (AZT)-resistant pheno type of a heavily mutated human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) carrying a dipeptide (Ser-Ser) insertion between codons 69 and 70 as well as other mutations related to resistance to RT inhibitors has been studied. Recombinant virus carrying this variant RT (termed SS RT) showed reduced susceptibility to all nucleoside RT inhibitors in clinical use, particularly to AZT. In the presence of ATP, recombinant SS RT had an increased ability to remove the 3'-terminal nucleotide from AZT- terminated primers and extend the unblocked primer, compared with wild-type HIV-1 RT (BH10 isolate). Insertion of two serines in the sequence context of BH10 RT did not affect the ATP-dependent phosphorolytic activity of the enzyme, and had no influence in resistance to RT inhibitors. However, SS RT mutants lacking the dipeptide insertion or bearing a four-serine insertion showed reduced ATP-dependent phosphorolytic activity that correlated with increased AZT sensitivity, as determined using a recombinant virus assay. Therefore, the insertion appears to be critical to enhance AZT resistance in the sequence context of multidrug-resistant HIV-1 RT.
Collapse
|
137
|
Ovalle A, Martínez MA, Gómez R, Sáez J, Menares I, Aspillaga C, Schwarze JE. [Premature labor with intact membranes: microbiology of the amniotic fluid and lower genital tract and its relation with maternal and neonatal outcome]. Rev Med Chil 2000; 128:985-95. [PMID: 11349503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
BACKGROUND The prevalence of idiopathic spontaneous premature labor or without an evident clinical cause, has not been reduced with tocolytic treatments, suggesting that premature labor has multiple causes and infections play a not well-defined role. AIM To perform microbiological studies of the amniotic fluid and of the lower genital tract in women with idiopathic premature labor and intact membranes, relating these findings with maternal and neonatal outcomes. PATIENTS AND METHODS Women with pregnancies between 24 and 34 weeks, with premature labor and without an evident clinical cause were enrolled. Amniotic fluid and genital tract samples were obtained for traditional microbiological cultures. This information was related with delivery events and neonatal outcome. RESULTS Sixty-three patients were included. The overall frequency of microbial invasion of amniotic cavity was 23.8% and of cervical or vaginal infection was 63.5% (in 39.7% there was only cervical or vaginal infection without involvement of the amniotic sac). Absence of infection was documented in 36.5% of women. Compared to patients without infection, women with microbial invasion of amniotic cavity had a higher rate of prematurity (73.3% p < 0.05), a higher rate of prematurity of less than 34 weeks (60% p < 0.01), a higher frequency of preterm rupture of membranes (40% p < 0.001), a shorter admission-to-delivery interval (median 3.0 days p < 0.01) and lower gestational age at delivery (median 33 weeks p < 0.01). Clinical chorioamnionitis and endometritis (20% p < 0.01) was observed only in patients with amniotic cavity infections. Severe asphyxia (26.7% p < 0.05) and neonatal admission to Intensive Care Units (46.7% p < 0.05) were more frequent and neonatal weight was less in the offspring of women with microbial invasion of amniotic cavity (2020 g median p < 0.01). CONCLUSIONS In preterm labor with intact membranes, intraamniotic infection is the most frequent cause of prematurity and is associated with a higher prevalence of maternal and neonatal problems.
Collapse
|
138
|
Yago MD, Martínez-Victoria E, Díaz RJ, Martínez MA, Singh J, Mañas M. Adaptation of the exocrine pancreas to dietary fats. J Physiol Biochem 2000; 56:295-306. [PMID: 11198166 DOI: 10.1007/bf03179797] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This article reviews studies on the adaptation of the exocrine pancreas to dietary fat. We include all the latest information about the mechanisms that underlie the adaptation of the secretory mechanism of the exocrine pancreas to the amount and the type of dietary fat. We review the kinetics of pancreatic adaptation and the mediators of the adaptive response of the pancreas including cellular and molecular mechanisms (modulation of intracellular messengers and gene expression of the different enzymes and secretagogues involved in the adaptation process). At the same time we include our results in this field in dogs and humans.
Collapse
|
139
|
García-Villalón AL, Padilla J, Fernández N, Monge L, Martínez MA, Gómez B, Diéguez G. Effect of neuropeptide Y on the sympathetic contraction of the rabbit central ear artery during cooling. Pflugers Arch 2000; 440:548-55. [PMID: 10958338 DOI: 10.1007/s004240000323] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In order to analyse the effect of neuropeptide Y (NPY) on the cutaneous vascular response to sympathetic nerve stimulation during cooling, the isometric response of isolated 2-mm segments of the rabbit central ear (cutaneous) artery was recorded at 37 degrees C and during cooling (30 degrees C). Electrical field stimulation (4-16 Hz) at 37 degrees C produced a frequency-dependent contraction, which was reduced during cooling (45% for 16 Hz) and potentiated by NPY (10(-8), 3x10(-8) and 10(-7) M), this potentiation being greater at 30 degrees C than at 37 degrees C. The NPY-induced potentiation of the contraction elicited by electrical field stimulation (8 Hz) was abolished by an antagonist of Y1 subtype NPY receptors, BIBP3226 (10(-6) M), at 37 degrees C and 30 degrees C, reduced by phentolamine (10(-6) M) at 30 degrees C but not at 37 degrees C, was not modified by the purinoceptor antagonist PPADS (3x10(-5) M) and was reduced by application of both phentolamine and PPADS at both temperatures. Both NiCl2 (10(-3) M) and verapamil (10(-5) M) abolished the potentiating effect of NPY at 37 degrees C and reduced it at 30 degrees C. Neither application of an inhibitor of nitric oxide synthesis, L-Nomega-nitro-arginine (L-NOARG, 10(-4) M), nor endothelium removal modified the potentiating effect of NPY at 37 degrees C or 30 degrees C. NPY (10(-8), 3x10(-8) and 10(-7) M) potentiated in a concentration-dependent way the arterial contraction in response to exogenous noradrenaline (10(-8)-10(-4) M) at 30 degrees C but not at 37 degrees C, and it increased the response to ATP (10(-4)-10(-2) M) at both temperatures. Therefore, in cutaneous (ear) arteries: (1) NPY potentiates the sympathetic response at 37 degrees C and at 30 degrees C, (2) this potentiating effect of NPY was more marked at 30 degrees C than at 37 degrees C, probably because of greater potentiation of the alpha-adrenoceptor response during cooling, and (3) the potentiating effect of NPY at both temperatures is mediated by NPY receptors of the Y1 subtype, is dependent of Ca2+ channels and is independent of the release of endothelial nitric oxide.
Collapse
|
140
|
Ovalle A, Martínez MA, Wolff M, Cona E, Valderrama O, Villablanca E, Lobos L. [Prospective, randomized, comparative study of the efficacy, safety and cost of cefuroxime versus cephradine in acute pyelonephritis during pregnancy]. Rev Med Chil 2000; 128:749-57. [PMID: 11050836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
BACKGROUND Second generation cephalosporins (CFPs) are more active in the treatment of acute pyelonephritis during pregnancy but their cost is considerably higher than their predecessors. Cefuroxime, a second generation CFP with oral and parenteral presentations, might offer significant advantages and become a first choice antimicrobial in this setting. AIM To compare the efficacy, safety and cost of cefuroxime and cephradine in the treatment of acute pyelonephritis in pregnancy. PATIENTS AND METHODS Hospitalized women with 12 to 34 weeks of pregnancy, with clinical and bacteriological diagnosis of acute pyelonephritis, were randomly assigned to receive cefuroxime (Curocef(r), Glaxo Wellcome) 750 mg t.i.d, i.v. or cephradine 1 g q.i.d., i.v. If the isolated organism was resistant to the assigned drug the patient was excluded. Once patients were afebrile, they were switched to an oral form of the same antimicrobial. They were discharged according to the clinical status and treated for a total of 14 days. laboratory tests, including urine culture were requested during controls and at the end of follow-up at 28 days. RESULTS One hundred and one patients were randomized: 49 to receive cephradine and 52 to receive cefuroxime. Patients in the cefuroxime group hed fewer febrile days (mean 1.7 vs 2.2, p < 0.05), faster clinical recovery (mean 2.7 vs 3.1 days, p < 0.05), a higher rate of bacteriological cure at 28 days (78.8% and 59.2%, p < 0.05) and lower rate of failure (21.2% vs 40.8% p < 0.05). The rate of resistance of isolated uropathogens was 14% to cephradine and 1% to cefuroxime. CONCLUSIONS Cefuroxime can be considered as a first choice option in the treatment of acute pyelonephritis during pregnancy due to its tolerance, microbiological activity and efficacy.
Collapse
|
141
|
Ricoy JR, Lobato RD, Báez B, Cabello A, Martínez MA, Rodríguez G. Suprasellar chordoid glioma. Acta Neuropathol 2000; 99:699-703. [PMID: 10867806 DOI: 10.1007/s004010051183] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Brat et al. (J Neuropathol Exp Neurol 57:288-290, 1998) reported eight cases of a new clinico-pathological entity, which occurs mainly in the third ventricle of middle-aged females, which they described as chordoid glioma of the third ventricle. We report a new case of a 41-year-old woman with a suprasellar chordoid glioma with histological, immunohistochemical and ultrastructural studies. We discuss the differential diagnosis between chordoma, chordoid meningioma, germinoma and pituitary adenoma. Histologically, the tumour showed cords and lobules of isomorphic epithelioid cells in a vacuolated matrix with prominent multifocal lymphoplasmacytic infiltrates in which some histiocytes and isolated Touton-type giant cells were seen; cells were immunoreactive for glial fibrillary acidic protein but negative for epithelial membrane antigen. Ultrastructural examination revealed abundant intermediate filament but no desmosomes, microvilli nor cilia were seen.
Collapse
|
142
|
Andrés A, Morales JM, Herrero JC, Praga M, Morales E, Hernández E, Ortuño T, Rodício JL, Martínez MA, Usera G, Díaz R, Polo G, Aguirre F, Leiva O. Double versus single renal allografts from aged donors. Transplantation 2000; 69:2060-6. [PMID: 10852597 DOI: 10.1097/00007890-200005270-00015] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND The age limit of the cadaver kidney donors is increasing in response to the growing demand for renal transplantation. Simultaneous double kidney transplantation (SDKT) with kidneys obtained from elderly adults has been proposed to increase the transplantation number and improve its results. However, if SDKT is performed when there are no clear indications, a negative effect could be produced on the total number of transplanted patients as both kidneys would be used for only one recipient. MATERIAL AND METHODS In December 1996 we designed a transplantation protocol to be able to extend the selection of cadaver kidney donors with normal serum creatinine levels without establishing any age limit. A pregraft renal biopsy was always performed to analyze the glomerulosclerosis (GE) percentage whenever the donors were 60 years of age or older. A SDKT was performed in a single recipient when the donor age was 75 years or older or when the donors between 60 and 74 years old had a GE rate of more than 15%. On the contrary, a single kidney transplantation was performed in two different recipients for kidneys from donors between 60 and 74 years of age with a GE rate of less than 15%. Kidneys having GE rates of more than 50% were discarded for transplantation. Donor kidneys from subjects younger than 60 years of age were always used for a single kidney transplantation. RESULTS Based on the above mentioned protocol, from December 1996 to May 1998, 181 patients received a kidney transplantation in our hospital. These patients were divided into three groups: group I which included the SDKT recipients (n=21), group II or single kidney recipients from 60- to 74-year-old donors (n=40), and group III or recipients from <60-year-old donors (n=120). The mean follow-up time was 15+/-5 months (range 6-24). Mean donor age was 75+/-7 years in group I, this was significantly higher than in group II (67+/-4, P<0.001) and group III (37+/-15, P<0.001). The primary nonfunction rate was low in the three groups, there being no statistically significant differences (5, 5, and 4%, respectively). A significantly greater percentage of patients from group I (76%) presented immediate renal graft function as compared with group II (43%, P<0.01) and III (50%, P<0.05). The acute rejections rate was very low in all three groups (9.5, 7.5, and 22%, respectively) with significant differences between groups II and III (P<0.05). No significant differences between the different groups were observed for one year actuarial patient survival (100, 95, and 98%, respectively) or graft survival rates (95, 90, and 93%, respectively). The 6-month serum creatinine levels were excellent in the three groups, although there were significant differences between groups I and II (1.6+/-0.3 vs. 1.9+/-0.6 mg/dl, P<0.05), II and III (1.9+/-0.6 vs. 1.4+/-0.4 mg/dl, P<0.001), and I and III (P<0.05). CONCLUSIONS Simultaneous double kidney transplantations make it possible to use kidneys from extremely elderly donors (>75 years) or those whose GE>15%. In addition, kidneys from donor 60-74 years old in which the GE<15% can be used for single kidney transplantations in two different recipients with excellent results.
Collapse
|
143
|
Sánchez-Alcázar JA, Schneider E, Martínez MA, Carmona P, Hernández-Muñoz I, Siles E, De La Torre P, Ruiz-Cabello J, García I, Solis-Herruzo JA. Tumor necrosis factor-alpha increases the steady-state reduction of cytochrome b of the mitochondrial respiratory chain in metabolically inhibited L929 cells. J Biol Chem 2000; 275:13353-61. [PMID: 10788444 DOI: 10.1074/jbc.275.18.13353] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The mechanism of tumor necrosis factor alpha (TNFalpha)-induced cytotoxicity in metabolically inhibited cells is unclear, although some studies have suggested that mitochondrial dysfunction and generation of reactive oxygen species may be involved. Here we studied the effect of TNFalpha on the redox state of mitochondrial cytochromes and its involvement in the generation of reactive oxygen species in metabolically inhibited L929 cells. Treatment with TNFalpha and cycloheximide (TNFalpha/CHX) induced mitochondrial cytochrome c release, increased the steady-state reduction of cytochrome b, and decreased the steady-state reduction of cytochromes cc(1) and aa(3). TNFalpha/CHX treatment also induced lipid peroxidation, intracellular generation of reactive oxygen species, and cell death. Furthermore, as the cells died mitochondrial morphology changed from an orthodox to a hyperdense and condensed and finally to a swollen conformation. Antimycin A, a mitochondrial respiratory chain complex III inhibitor that binds to cytochrome b, blocked the formation of reactive oxygen species, suggesting that the free radicals are generated at the level of cytochrome b. Moreover, antimycin A, when added after 3 h of TNFalpha/CHX treatment, arrested the further release of cytochrome c and the cytotoxic response. We propose that the reduced cytochrome b promotes the formation of reactive oxygen species, lipid peroxidation of the cell membrane, and cell death.
Collapse
|
144
|
Giménez-Barcons M, Sánchez-Fueyo A, Ampurdanés S, Puig-Basagoiti F, Guilera M, Ibáñez A, Clotet B, Martínez MA, Rodés J, Saiz JC, Sánchez-Tapias JM. Genetic evolution of GB virus C/hepatitis G virus (GBV-C/HGV) under interferon pressure. Antiviral Res 2000; 46:157-70. [PMID: 10854667 DOI: 10.1016/s0166-3542(00)00079-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The epidemiology and clinical features of chronic GBV-C/HGV infection have largely been explored, but there is little information about the mechanisms enabling GBV-C/HGV to cause persistent infection. Since analysis of the genomic variation of GBV-C/HGV under interferon pressure might provide some insight into this issue, we analyzed the nucleotide sequence variation of the 5'NC and NS3 regions in GBV-C/HGV isolates obtained sequentially from seven patients co-infected with HCV and treated with interferon. A reduction of GBV-C/HGV-RNA serum level below the detection limit of the RT-PCR assay was observed during treatment in all patients, but upon interferon withdrawal, viral RNA remained undetectable in only two patients. Among the five patients who did not clear GBV-C/HGV-RNA, viral strains emerging after treatment were identical to those present at baseline in three cases. In a further case, in whom GBV-C/HGV-RNA re-emerged during therapy (breakthrough episode), several mutations appeared in relapse samples. In the remaining patient, with a mixed infection before therapy, only one of the two GBV-C/HGV strains present at baseline was detected upon treatment withdrawal. These data raise the possibility that positive selection may act over GBV-C/HGV genome during interferon therapy, and contribute to persistence of infection with this virus.
Collapse
MESH Headings
- Base Sequence
- DNA, Viral/genetics
- Evolution, Molecular
- Flaviviridae/genetics
- Genome, Viral
- Hepatitis, Chronic/drug therapy
- Hepatitis, Chronic/virology
- Hepatitis, Viral, Human/drug therapy
- Hepatitis, Viral, Human/virology
- Humans
- Interferon alpha-2
- Interferon-alpha/pharmacology
- Molecular Sequence Data
- Phylogeny
- RNA, Viral/genetics
- Recombinant Proteins
- Selection, Genetic
- Sequence Homology, Nucleic Acid
- Time Factors
Collapse
|
145
|
Martínez MA, Cabana M, Parera M, Gutierrez A, Esté JA, Clotet B. A bacteriophage lambda-based genetic screen for characterization of the activity and phenotype of the human immunodeficiency virus type 1 protease. Antimicrob Agents Chemother 2000; 44:1132-9. [PMID: 10770741 PMCID: PMC89834 DOI: 10.1128/aac.44.5.1132-1139.2000] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) resistance to antiretroviral drugs is the main cause of patient treatment failure. Despite the problems associated with interpretation of HIV-1 resistance testing, resistance monitoring should help in the rational design of initial or rescue antiretroviral therapies. It has previously been shown that the activity of the HIV-1 protease can be monitored by using a bacteriophage lambda-based genetic assay. This genetic screening system is based on the bacteriophage lambda regulatory circuit in which the viral repressor cI is specifically cleaved to initiate the lysogenic to lytic switch. We have adapted this simple lambda-based genetic assay for the analysis of the activities and phenotypes of different HIV-1 proteases. Lambda phages that encode HIV-1 proteases either from laboratory strains (strain HXB2) or from clinical samples are inhibited in a dose-dependent manner by the HIV-1 protease inhibitors indinavir, ritonavir, saquinavir, and nelfinavir. Distinct susceptibilities to different drugs were also detected among phages that encode HIV-1 proteases carrying different resistance mutations, further demonstrating the specificity of this assay. Differences in proteolytic processing activity can also be directly monitored with this genetic screen system since two phage populations compete in culture with each other until one phage outgrows the other. In summary, we present here a simple, safe, and rapid genetic screening system that may be used to predict the activities and phenotypes of HIV-1 proteases in the course of viral infection and antiretroviral therapy. This assay responds appropriately to well-known HIV-1 protease inhibitors and can be used to search for new protease inhibitors.
Collapse
|
146
|
García-Villalón AL, Fernández N, Monge L, Martínez MA, Gómez B, Diéguez G. Insulin effects on the sympathetic contraction of rabbit ear arteries. GENERAL PHARMACOLOGY 2000; 34:221-6. [PMID: 11282215 DOI: 10.1016/s0306-3623(00)00063-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Electrical field stimulation (4 Hz, 0.2 ms, 70 V supramaximal voltage, 10 s duration) produced contraction of perfused rabbit central ear arteries, and this contraction was reduced by incubation with insulin (0.6--200 mU/ml). This inhibitory effect of insulin was not significantly modified by removing the endothelium, or by treatment with N(W)-nitro-L-arginine (L-NA, 10(-4) M), meclofenamate (10(-5) M), ouabain (10(-6) M), or cocaine (10(-5) M). Insulin (200 mU/ml) did not modify the vascular contraction due to exogenous norepinephrine (10(-8)--10(-4) M) nor the relaxation due to acetylcholine (10(-8)--10(-4) M). This suggests that insulin may reduce vascular contraction by sympathetic stimulation, and this effect is not dependent on endothelial nitric oxide, prostanoids, or Na(+)--K(+) pump activation.
Collapse
|
147
|
García-Villalón AL, Monge L, Fernández N, Sánchez MA, Martínez MA, Gómez B, Diéguez G. Impaired potentiation by endothelin-1 and vasopressin of sympathetic contraction in tail artery from hypertensive rats. Cardiovasc Res 2000; 45:463-9. [PMID: 10728367 DOI: 10.1016/s0008-6363(99)00279-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
OBJECTIVE To analyse the effects of endothelin-1 and vasopressin on the sympathetic vasoconstriction during hypertension. METHODS Electrical field stimulation (4 Hz) was applied to isolated, 2 mm segments of the tail artery from spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats prepared for isometric tension recording. RESULTS The contraction to electrical stimulation was potentiated by endothelin-1 (10(-10)-10(-8) M) in arteries from WKY but not from SHR, and by vasopressin (10(-12)-10(-10) M) more markedly in arteries from WKY than from SHR. The potentiation by endothelin-1 was reduced more markedly by the antagonist of endothelin ETA receptors BQ-123 (10(-5) M) than by the endothelin ETB receptor antagonist BQ-788 (10(-5) M). The potentiation by vasopressin was reduced by the antagonist of vasopressin V1 receptors d(CH2)5Tyr(Me)AVP (10(-7) M), but not by the vasopressin V2 receptor antagonist d(CH2)5D-Ile2, Ile4AVP (10(-7) M). The blocker of L-type calcium channels verapamil (10(-5) M) reduced the potentiation by both endothelin-1 and vasopressin in arteries from WKY rats, and increased the potentiation by vasopressin in arteries from SHR. Noradrenaline (10(-8)-10(-4) M) contraction was not modified by endothelin-1 (3 x 10(-9) M) or vasopressin (3 x 10(-11) M), and contraction to endothelin-1 (10(-9)-10(-7) M) and vasopressin (10(-10)-10(-7) M) was lower in arteries from SHR than from WKY rats. CONCLUSIONS (1) The potentiation by endothelin-1 and vasopressin of the sympathetic vasoconstriction, probably due to increased release of noradrenaline, is impaired during hypertension, and (2) this potentiation is mediated mainly by endothelin ETA receptors, and by vasopressin V1 receptors, in both WKY and SHR, and for both peptides it is mediated by L-type calcium channels in arteries from normotensive but not in those from hypertensive animals.
Collapse
|
148
|
Fernández N, Sánchez MA, Martínez MA, García-Villalón AL, Monge L, Gómez B, Diéguez G. Role of nitric oxide in vascular tone and in reactivity to isoproterenol and adenosine in the goat coronary circulation. Eur J Pharmacol 2000; 387:93-9. [PMID: 10633166 DOI: 10.1016/s0014-2999(99)00766-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The present study examined the role of nitric oxide in coronary vascular tone and in the coronary vasodilatation in response to beta-adrenoceptor stimulation and adenosine. In anesthetized goats, the effects of intracoronary and i.v. administration of the inhibitor of nitric oxide synthesis, N(w)-nitro-L-arginine methyl ester (L-NAME), and those of isoproterenol, adenosine and acetylcholine on coronary blood flow, measured electromagnetically in the left circumflex coronary artery, were recorded. Intracoronary infusion of L-NAME (30-40 microg kg(-1) min(-1), four goats) reduced resting coronary blood flow by 14+/-3% (P<0.05) without changing arterial pressure and heart rate. L-NAME (40 mg kg(-1), eight goats) i.v. reduced resting coronary blood flow by 19+/-4% (P<0.05), increased mean systemic arterial pressure by 22+/-3% (P<0.01) and decreased heart rate by 10+/-2% (P<0.05). These effects of L-NAME were partially, but significantly reversed by L-arginine (six goats). Isoproterenol (10-100 ng, eight goats), adenosine (0.3-10 microg, seven goats) and acetylcholine (3-100 ng, five goats), injected intracoronarily, increased coronary conductance in a dose-dependent way and, under control conditions, these increases for isoproterenol, ranged from 32+/-5% to 82+/-12%; for adenosine, 6+/-2% to 174+/-22%; and for acetylcholine, 39+/-5% to 145+/-15%. During i.v. L-NAME the increases in coronary conductance induced by isoproterenol and acetylcholine were significantly reduced by about 50 and 60% (P<0.05), respectively, whereas those induced by adenosine were significantly increased further (about 30-100%, P<0. 05). During L-NAME plus L-arginine, the effects of isoproterenol, acetylcholine and adenosine on coronary conductance were not significantly different from those under control conditions. Therefore, it is suggested that in the coronary circulation: (a) nitric oxide may produce a basal vasodilator tone under normal conditions; (b) nitric oxide may be an intermediate in the vasodilatation due to beta-adrenoceptor stimulation and acetylcholine, and (c) the vasodilatation due to adenosine is potentiated during reduction of nitric oxide production.
Collapse
|
149
|
Puig-Basagoiti F, Cabana M, Guilera M, Giménez-Barcons M, Sirera G, Tural C, Clotet B, Sánchez-Tapias JM, Rodés J, Saiz JC, Martínez MA. Prevalence and route of transmission of infection with a novel DNA virus (TTV), hepatitis C virus, and hepatitis G virus in patients infected with HIV. J Acquir Immune Defic Syndr 2000; 23:89-94. [PMID: 10708061 DOI: 10.1097/00126334-200001010-00012] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES To evaluate the prevalence, route of transmission and clinical significance that current co-infection with TT virus (TTV), hepatitis C virus (HCV), and hepatitis G virus (HGV) have in HIV-1-infected patients. DESIGN Presence of TTV, HCV, and HGV was analyzed in plasma samples from 160 HIV-1-infected patients with parenteral (38 intravenous drug users [IVDUs] and 41 patients with hemophilia) or sexual (39 homosexuals and 42 heterosexuals) risk of exposure, and in 168 volunteer blood donors. Alanine aminotransferase (ALT) levels and CD4+ counts were also analyzed. METHODS HCV and HGV RNA were detected by specific reverse transcriptase (RT) nested polymerase chain reaction (PCR) and TTV DNA by specific heminested PCR. RESULTS TTV DNA was detected in 39% of the patients and in 14% of the volunteer blood donors. HCV and HGV infections were detected in 42% and in 14% of the patients, and in 0% and 3% of the blood donors, respectively. Prevalences of TTV and HCV infection were higher among patients with parenteral (62% and 68%) than in those with sexual (17% and 16%) risk of exposure. A higher prevalence of TTV infection (but not of HCV or HGV infection) was observed among patients with hemophilia (76%) than IVDUs (47%), and among homosexuals (26%) than among heterosexuals (10%). Abnormal ALT levels were related with the presence of HCV infection, independently of the detection of TTV DNA. TTV infection did not seem to alter the levels of CD4+ T cells. CONCLUSIONS Prevalence of current TTV infection is high among HIV-infected patients with parenteral risk of exposure, but TTV is also transmitted through sexual routes; detection of TTV does not seem to influence the clinical or immune status of HIV-infected patients.
Collapse
|
150
|
Ibáñez A, Clotet B, Martínez MA. Human immunodeficiency virus type 1 population bottleneck during indinavir therapy causes a genetic drift in the env quasispecies. J Gen Virol 2000; 81:85-95. [PMID: 10640545 DOI: 10.1099/0022-1317-81-1-85] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The impact of emergence of genetic resistance, soon after the beginning of antiretroviral therapy, on the genotype of other viral loci not implicated in the development of resistance was studied in four human immunodeficiency type 1 (HIV-1)-infected patients subjected to indinavir monotherapy. Two patients were chosen because they showed no decrease in virus load during the study period and two were selected because they showed a rapid decline in plasma viraemia after the initiation of therapy and a virus rebound after 12 weeks of treatment. The evolution of virus sequences was analysed within the four infected patients by examining virus sequences spanning the protease and C2-V3 env genes by RT-PCR of plasma samples obtained at the beginning and after 12 weeks of therapy. PCR products from the two genomic regions from the two sample points per patient were cloned and 10-15 clones from each sample were sequenced. Genotypic indinavir resistance was present in the four patients after 12 weeks of therapy. The overall protease and C2-V3 env regions quasispecies diversity at time zero was higher than that after 12 weeks of therapy, but this difference was more significant in the two patients who showed a reduction in virus load soon after the initiation of treatment. C2-V3 env sequences indicated that changes during emergence of resistance to indinavir were only detected in the two patients who showed a drastic reduction in virus load. Thus, a temporal relationship was observed between the start of therapy, a drastic reduction in virus load and a drift in the HIV-1 env quasispecies.
Collapse
|