Carmovirus isolation and RNA extraction.
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Carmovirus↗
Biomedical subjects
J Díez
Publications and source records attributed to J Díez.
[Epidemiology of Haemophilus influenzae type b, Neisseria meningitidis, and Streptococcus pneumoniae in children in the Valencia Community, Spain. Acute diseases study group].
OBJECTIVE: To asses the incidence of Haemophilus influenzae type b (Hib), Neisseria meningitidis and Streptococcus pneumoniae meningitis in children of de Valencian Community (VC), Spain, and to describe the microbiologic characteristics. MATERIAL AND METHODS: Prospective surveillance system with paediatrician and microbiologist participation of all public hospitals of the VC. Cases are children less than 15 with clinical meningitis and with isolation of Hib, N. meningitidis or S. pneumoniae from CSF of blood. RESULTS: From 1st December 1995 to 30th November 1996, 51 cases were declared, 33.3% were Hib, 49.0% N. meningitidis and 17.7% S. pneumoniae. The annual incidence of meningitis was 7.6 cases/100,000 < 15 years, 20.5/100,000 < 5 years and 56.2/100,000 < 1 year. 84.3% of the cases occurred in children younger than 5. S. pneumoniae had the highest mortality. CONCLUSIONS: Hib is a frequent cause of meningitis in spite of that one third of children are vaccinated. 43% of the N. meningitidis isolated in meningitis are serogroup C. S. pneumoniae meningitis are more frequent in children less than one, and has a high mortality rate.
Adolescent↗
Altered regulation of smooth muscle cell proliferation and apoptosis in small arteries of spontaneously hypertensive rats.
AIM: It has been proposed that alterations of the balance between programmed cell death and cell replication might be involved in abnormalities of smooth muscle cell growth in arterial hypertension. This study was designed to analyse some regulators of apoptosis and proliferation in smooth muscle cells of small intra-myocardial arteries from the left ventricle of adult normotensive Wistar-Kyoto rats (WKY) and adult spontaneously hypertensive rats (SHR). Therefore, we assessed the expression of the cytoplasmic proteins Bax and Bcl-2, respectively a promoter and an inhibitor of apoptosis, and the expression of cyclin A, a nuclear protein that induces proliferation of smooth muscle cells. METHODS AND RESULTS: We measured the percentages of smooth muscle cells expressing these proteins using monoclonal antibodies and the avidin-biotin immunoperoxidase method. Compared with WKY, cells from SHR exhibited normal Bax expression, increased (P < 0.001) Bcl-2 expression and increased (P < 0.001) cyclin A expression. The ratio of Bax to Bcl-2, an index of cell susceptibility to apoptosis, was lower (P < 0.001) in SHR than in WKY. Systolic blood pressure was directly correlated (P < 0.01) with Bcl-2 and cyclin A in SHR. CONCLUSION: These results suggest that apoptosis and proliferation of smooth muscle cells might be inhibited and stimulated, respectively, in small arteries of adult SHR. The imbalance between these two processes may account for abnormalities of smooth muscle cell growth in the arterial wall in genetic hypertension.
Animals↗
Yeast mutations in multiple complementation groups inhibit brome mosaic virus RNA replication and transcription and perturb regulated expression of the viral polymerase-like gene.
Brome mosaic virus (BMV), a member of the alphavirus-like superfamily of positive-strand RNA viruses, encodes two proteins, 1a and 2a, that interact with each other, with unidentified host proteins, and with host membranes to form the viral RNA replication complex. Yeast expressing 1a and 2a support replication and subgenomic mRNA synthesis by BMV RNA3 derivatives. Using a multistep selection and screening process, we have isolated yeast mutants in multiple complementation groups that inhibit BMV-directed gene expression. Three complementation groups, represented by mutants mab1-1, mab2-1, and mab3-1 (for maintenance of BMV functions), were selected for initial study. Each of these mutants has a single, recessive, chromosomal mutation that inhibits accumulation of positive- and negative-strand RNA3 and subgenomic mRNA. BMV-directed gene expression was inhibited when the RNA replication template was introduced by in vivo transcription from DNA or by transfection of yeast with in vitro transcripts, confirming that cytoplasmic RNA replication steps were defective. mab1-1, mab2-1, and mab3-1 slowed yeast growth to varying degrees and were temperature-sensitive, showing that the affected genes contribute to normal cell growth. In wild-type yeast, expression of the helicase-like 1a protein increased the accumulation of 2a mRNA and the polymerase-like 2a protein, revealing a new level of viral regulation. In association with their other effects, mab1-1 and mab2-1 blocked the ability of 1a to stimulate 2a mRNA and protein accumulation, whereas mab3-1 had elevated 2a protein accumulation. Together, these results show that BMV RNA replication in yeast depends on multiple host genes, some of which directly or indirectly affect the regulated expression and accumulation of 2a.
Bromovirus↗
Monitoring fibrillar collagen turnover in hypertensive heart disease.
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Animals↗
The use of IgE immunoblotting as a diagnostic tool in Anisakis simplex allergy.
BACKGROUND: The fish parasite Anisakis simplex is the etiologic agent of anisakiasis and induces IgE-mediated reactions. Skin prick tests (SPTs) and the measurement of specific IgE to A. simplex were, in our experience, not valid tools with which to discriminate between allergic and nonallergic patients because many control subjects also had positive results. OBJECTIVE: The study was carried out to assess the usefulness of IgE immunoblotting in the diagnosis of allergy to A. simplex. METHODS: We have studied 61 patients with acute symptoms of urticaria, angioedema, or anaphylaxis and positive specific IgE to A. simplex. According to the anamnesis, time interval between ingestion of fish and clinical onset of symptoms, and exclusion of other causes of allergy, three different groups of patients were established: group A (allergic), group NA (non-allergic), and group D (doubtful). Fifty-one healthy donors were included as control subjects (group C). IgE immunoblotting with A. simplex whole-body extract was performed in all patients and control subjects. RESULTS: Four patterns of immunoblotting were observed: type 1, with a group of several bands of medium molecular weight and others of low molecular weight; type 2, two or more bands of medium molecular weight; type 3, only one band of medium molecular weight; type 4, without any band. There was a significant predominance of blotting type 1 in group A and type 4 in group C. CONCLUSION: These data suggest that IgE immunoblotting is the most useful approach to A. simplex allergy diagnosis.
Acute Disease↗
Angiotensin converting enzyme inhibition corrects Na+/H+ exchanger overactivity in essential hypertension.
In this study, we investigated whether antihypertensive treatment with the angiotensin converting enzyme inhibitor quinapril modifies Na+/H+ exchanger activity or NHE-1 (isoform of the exchanger) mRNA expression in lymphocytes from patients with essential hypertension. Thirty-three hypertensive patients and 27 normotensive subjects were studied. Maximal sodium-proton exchange activity was determined by acidifying cell pH and measuring the initial rate of the net sodium-dependent proton efflux driven by an outward proton gradient. The transcript level of NHE-1 was measured by reverse transcription-polymerase chain reaction in comparison with a constitutively expressed reference gene (beta-actin). With the 100% confidence (upper) limit of the normotensive population as a cutoff point, a subgroup of 11 hypertensive patients had an abnormally high lymphocyte Na+/H+ exchange activity (group A). The activity of the exchanger was within the normal range in the remaining patients (group B). After 6 months of quinapril treatment the activity of the exchanger decreased to normal values (P < .001) in patients from group A, but remained unchanged in patients from group B. The NHE-1 mRNA expression was not modified with treatment neither in patients from the group A, nor in patients from the group B. These results suggest that chronic angiotensin enzyme inhibition with quinapril abolishes Na+/H+ exchange overactivity present in lymphocytes from a subgroup of hypertensive patients. This effect appears to be independent of changes in the expression of the mRNA encoding for the NHE-1 isoform of the exchanger.
Adult↗
Quinapril inhibits c-Myc expression and normalizes smooth muscle cell proliferation in spontaneously hypertensive rats.
A number of data suggest that angiotensin II-dependent activation of the protooncogene c-myc participates in the proliferative response of smooth muscle cells (SMC) of rats with spontaneous hypertension (SHR). We therefore investigated the effects of chronic treatment with the angiotensin converting enzyme (ACE) inhibitor quinapril on the oncoprotein c-Myc and the proliferating cell nuclear antigen cyclin A in SMC of small intramyocardial arteries from the left ventricle of SHR. The expression of c-Myc and cyclin A was assessed by immunocytochemical analysis. The number of smooth muscle cells was assessed by morphometrical analysis. As compared to normotensive Wistar-Kyoto (WKY) rats, untreated SHR exhibited an increased percentages of cells expressing c-Myc (33% +/- 4% v 19% +/- 2%, mean +/- SEM, P < .005) and cyclin A (25 +/- 2 v 11% +/- 1%, P < .001). In quinapril-treated SHR compared with untreated SHR, we found decreased expression of c-Myc (22% +/- 2%, P < .005) and cyclin A (13% +/- 1%, P < .001). No significant differences were found between WKY rats and quinapril-treated SHR in the above parameters. Cyclin A was directly correlated with the number of SMCs in each group of rats. These results suggest that an enhanced expression of c-Myc may be involved in the increased proliferation seen in SMCs from small arteries of SHR. Quinapril administration normalizes proliferation in the SMCs of SHR, possibly by inhibiting the expression of the oncoprotein c-Myc and its effects on the cell cycle.
Angiotensin-Converting Enzyme Inhibitors↗
Is the tissue availability of circulating insulin-like growth factor I involved in organ damage and glucose regulation in hypertension?
BACKGROUND: Besides its capacity to regulate organ and tissue growth, the insulin-like growth factor I exerts biologic actions that resemble those of insulin. Tissue access of the factor depends on the distribution of the circulating bound factor between its binding protein 3 that remains within the intravascular space and its binding protein 1 that is able to cross the endothelium. OBJECTIVE: To investigate whether the distribution of the circulating factor between its binding proteins is altered in patients with essential hypertension and whether this is related to changes in organ damage and glucose regulation in these patients. DESIGN: The study subjects were 30 never-treated patients with essential hypertension and 27 age- and sex-matched normotensive controls. METHODS: Serum insulin-like growth factor I-binding proteins 3 and 1 and plasma insulin-like growth factor I levels were determined by specific radioimmunoassays. RESULTS: Insulin-like growth factor I levels were significantly higher in the hypertensive patients than they were in the normotensive controls. Whereas the serum level of binding protein 1 was significantly higher in hypertensives than it was in controls, we found no differences in the level of binding protein 3 between the two groups. With the upper 100% confidence limit of the normotensive population as the cut-off point, a subgroup of 16 hypertensives had an abnormally high serum level of binding protein 1. Compared with patients with normal binding protein 1 levels, patients with increased binding protein 1 levels were characterized by the following: lower fasting glucose and insulin levels, lower insulin: glucose ratios, lower triglyceride levels, higher left ventricular mass indexes, higher creatinine clearances and higher urinary albumin excretion rates. The serum binding protein 1 level was correlated inversely to the plasma insulin level for the whole group of hypertensives. CONCLUSIONS: These results show that the distribution of circulating insulin-like growth factor I between its binding proteins 1 and 3 is altered in essential hypertension. Thus, there is a subgroup (53%) of hypertensive patients with increased serum levels of insulin-like growth factor I-binding protein 1. Access of the circulating factor to tissues is more easily achieved in these patients. The clinical characteristics of this subgroup of patients suggest that the tissue availability of insulin-like growth factor I is a determinant of organ damage and insulin sensitivity in essential hypertension.
Adult↗
Is the regulation of apoptosis altered in smooth muscle cells of adult spontaneously hypertensive rats?
Whereas the protein product of the Bcl-2 gene inhibits apoptosis, the protein product of the Bax gene acts as a promoter of apoptosis. To gain insight into the regulation of apoptosis in vascular smooth muscle cells in arterial hypertension, we investigated the expression of the proteins Bcl-2 and Bax in small intramyocardial arteries of 36-week-old normotensive Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). In addition, 16-week-old SHR were treated for 20 weeks with the angiotensin-converting enzyme inhibitor quinapril and killed at 36 weeks of age. We measured the percentages of smooth muscle cells expressing these proteins using monoclonal antibodies and the avidin-biotin immunoperoxidase method. Compared with WKY, untreated SHR exhibited increased (P<.001) Bcl-2 expression and similar Bax expression. Values of Bcl-2 measured in quinapril-treated SHR were significantly lower than values measured in untreated SHR and similar to values measured in WKY. Quinapril-treated SHR showed higher (P<.001) Bax expression than WKY and untreated SHR. Bcl-2 expression was directly correlated with systolic pressure. Inverse correlations were found between the expression of Bax and the activities of both cardiac and circulating angiotensin-converting enzyme. These findings suggest that smooth muscle cell apoptosis might be inhibited in small arteries of adult SHR as a consequence of an excess of the protein Bcl-2. In addition, our results suggest that chronic angiotensin-converting enzyme inhibition might restore the susceptibility to apoptosis in these cells through stimulation of the protein Bax.
Angiotensin-Converting Enzyme Inhibitors↗
Cardiomyocyte apoptosis and cardiac angiotensin-converting enzyme in spontaneously hypertensive rats.
Increased apoptosis has been reported in the heart of rats with spontaneous hypertension and cardiac hypertrophy. This study was designed to investigate the relationship between apoptosis and hypertrophy in cardiomyocytes from the left ventricle of spontaneously hypertensive rats (SHR). In addition, we evaluated whether the development of cardiomyocyte apoptosis is related to blood pressure or to the activity of the local angiotensin-converting enzyme (ACE) in SHR. The study was performed in 16-week-old SHR, 30-week-old untreated SHR, and 30-week-old SHR treated with quinapril (10 mg x kg[-1] x d[-1]) during 14 weeks before they were killed. Cardiomyocyte apoptosis was assessed by direct immunoperoxidase detection of digoxigenin-labeled 3'-hydroxyl ends of DNA. Nuclear polyploidization measured by DNA flow cytometry was used to assess cardiomyocyte hypertrophy. Compared with 16-week-old normotensive Wistar-Kyoto rats, 16-week-old SHR exhibited increased blood pressure (P<.001), increased rate of tetraploidy (P<.05), and similar levels of ACE activity and apoptosis. Compared with 30-week-old Wistar-Kyoto rats, 30-week-old SHR showed increased blood pressure (P<.001), increased ACE activity (P<.05), increased rate of tetraploidy (P<.01), and increased apoptosis (P<.01). Untreated 30-week-old SHR exhibited similar values of blood pressure and tetraploidy and higher ACE activity (P<.05) and apoptosis (P<.001) than 16-week-old SHR. A direct correlation (P<.01) was found between ACE activity and the apoptotic index in untreated 30-week-old SHR. The long-term administration of quinapril was associated with the normalization of ACE activity and apoptosis in treated SHR. These results suggest that the timing and mechanisms responsible for apoptosis and hypertrophy of cardiomyocytes are different in SHR. Whereas hypertrophy seems to be an earlier alteration that develops in parallel with hypertension, apoptosis develops later in association with overactivity of the local ACE. Our data suggest that cell death dysregulation may be a novel target for antihypertensive agents that interfere with the renin-angiotensin system in hypertension.
Animals↗
[Meningitis caused by non-serotypable Haemophilus influenzae, biotype V].
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Bacterial Capsules↗
Is the extracellular degradation of collagen type I fibers depressed in spontaneously hypertensive rats with myocardial fibrosis?
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Animals↗
Serum markers of collagen type I metabolism in spontaneously hypertensive rats: relation to myocardial fibrosis.
BACKGROUND: The assay of serum peptides of extracellular collagen synthesis and degradation could provide an indirect estimate of the rate of fibrillar turnover. This study was designed to investigate whether serum peptides of collagen type I synthesis and degradation are altered in spontaneously hypertensive rats (SHR) with left ventricular hypertrophy and whether these serum collagen-derived peptides are related to myocardial fibrosis. METHODS AND RESULTS: We measured serum levels of carboxyterminal propeptide of procollagen type I (PIP) as a marker of collagen I synthesis and serum levels of the pyridinoline crosslinked telopeptide domain of collagen type I (CITP) as a marker of fibrillar collagen I degradation in ten 36-week-old normotensive Wistar-Kyoto (WKY) rats, ten 36-week-old SHR, and ten 16-week-old SHR treated with the angiotensin-converting enzyme inhibitor quinapril (10 mg /kg body wt per day, orally) for 20 weeks. PIP and CITP were determined by specific radioimmunoassays. Histomorphometric and immunohistochemical studies of the left ventricle were performed in all rats. In untreated SHR compared with WKY rats, we found a more extensive interstitial and perivascular fibrosis, an increased (P<.01) collagen volume fraction, a more marked deposition of collagen type I, an increased (P<.01) serum concentration of PIP, and a similar serum concentration of CITP. In quinapril-treated SHR compared with untreated SHR, we found an absence of left ventricular hypertrophy, a marked decrease of fibrosis, a lower (P<.01) collagen volume fraction, a diminished deposition of collagen type I, a decreased (P<.01) concentration of PIP, and a similar concentration of CITP. A direct correlation was found between the collagen volume fraction and serum PIP (r=.753, P<.05) in untreated SHR. CONCLUSIONS: These results suggest that tissue metabolism of collagen type I is abnormal in SHR and can be normalized by treatment with quinapril. On the basis of our findings, we propose that serum PIP may be a marker of collagen type I-dependent myocardial fibrosis in rats with genetic hypertension.
Animals↗
Growth hormone responses to growth hormone-releasing hormone and clonidine before and after erythropoietin therapy in CAPD patients.
Correction of anemia with recombinant human erythropoietin (rhEPO) in patients with end-stage renal disease has been associated with improvement of several abnormalities in hypothalamo-hypophyseal functions. The aim of the present work was to evaluate the growth hormone (GH) responses to GH-releasing hormone (GHRH) and clonidine stimulation, as well as the baseline concentrations of insulin-like growth factor I(IGF-I), before and after the correction of anemia with rhEPO in a group of uremic patients undergoing continuous ambulatory peritoneal dialysis (CAPD). Nine clinically stable patients (1 male, 8 female; mean age 55.4 years; mean duration of CAPD 14.1 months) were studied. Twelve normal volunteers were studied as controls. GHRH and clonidine stimulation tests were performed prior to starting rhEPO and again after partial correction of anemia with rhEPO therapy (60-130 U/kg/week, s.c., for 12 weeks). Blood samples for GH were collected during 2 h after GHRH (100 micrograms i.v. in bolus) or clonidine (0.15 mg/m2, p.o.) administration. In basal plasma samples IGF-I concentrations were also measured. Mean (+/- SEM) blood hemoglobin concentration rose from 5.32 +/- 0.25 to 7.22 +/- 0.25 mmol/l (p < 0.001) after rhEPO treatment. GH responses to GHRH were characterized by marked differences in single patients when compared with the control group. However, the GH peak and the area under the secretory curves (AUC) of GH responses in CAPD patients (9.89 +/- 4.01 micrograms/l and 15.06 +/- 6.02 micrograms.h/l, respectively) did not differ from those obtained in control subjects (14.58 +/- 3.25 microgram/l and 16.94 +/- 4.31 microgram.h/l, respectively). The study after correction of anemia showed an evident potentiation of GH values that reached statistically significant values at 60 and 90 min. GH AUC after rhEPO therapy rose to 25.61 +/- 9.25 micrograms.h/l (p = 0.01). In control subjects, clonidine administration was followed by a GH release that reached a maximum at 90 min (7.67 +/- 2.24 micrograms/l). However, CAPD patients exhibited a blunted response to clonidine both before (2.00 +/- 0.78 microgram/l) and after (2.78 +/- 0.76 microgram/l, NS) correction of the anemia with rhEPO. On the other hand, IGF-I concentrations after rhEPO therapy (32.05 +/- 5.52 nmol/l) were not significantly different from those found prior to starting therapy (38.13 +/- 8.44 nmol/l). In conclusion, these results suggest that correction of the anemia with rhEPO therapy potentiates GH responses to direct pituitary stimulation with GHRH although it is unable to restore the blunted response of GH to clonidine that is found in CAPD patients.
Adrenergic alpha-Agonists↗
Vasoconstriction of the afferent arteriole and defective renal synthesis of nitric oxide in essential hypertension.
This study was designed to investigate whether some relation exists between afferent arteriolar resistance (AAR) and the renal production of nitric oxide (NO) and prostacyclin (PGI2) in 21 patients with untreated essential hypertension and 20 normotensive controls. All subjects were studied in conditions of an unlimited Na+ diet both basally and after a four-hour amino acid infusion. AAR was calculated using Gomez's equations. Renal production of NO and PGI2 were assessed by radioimmunoassay of the urinary excretion of cGMP and 6-keto-PGF1 alpha, respectively. Baseline AAR was higher (P < 0.01) in hypertensives than in normotensives. The baseline urinary excretion of 6-keto-PGF1 alpha and cGMP were similar in the two groups of subjects. AAR diminished (P < 0.005) in normotensives and remained unchanged in hypertensives after amino acid infusion. Urinary excretion of 6-keto-PGF1 alpha was increased similarly in the two groups of subjects after infusion. Urinary excretion of cGMP remained unchanged in normotensives and decreased by 31% in hypertensives after infusion. These findings suggest that afferent vasoconstriction present in hypertensive patients is unresponsive to the vasodilatory manoeuvre of amino acid infusion. This lack of response may be due to a defective renal synthesis of NO in these patients.
6-Ketoprostaglandin F1 alpha↗
Toward the biochemical assessment of myocardial fibrosis in hypertensive patients.
The serum concentrations of amino-terminal procollagen type III and carboxy-terminal procollagen type I-derived peptides, which have been proposed as useful markers of the tissue synthesis of collagen types III and type I, respectively, were abnormally increased in patients with essential hypertension and became normal after angiotensin-converting enzyme (ACE) inhibition. An association was found between baseline serum concentrations of these peptides and left ventricular hypertrophy, diastolic dysfunction, and ventricular arrhythmias in hypertensive patients. On the other hand, increased serum concentration of the carboxy-terminal procollagen type I-derived peptide was found in spontaneously hypertensive rats compared with normotensive Wistar-Kyoto control rats. An association was found between the serum concentration of this peptide and the extent of myocardial fibrosis and the hydroxyproline concentration in the left ventricle of spontaneously hypertensive rats. It is proposed that procollagen-derived peptides in serum may be markers of exaggerated collagen tissue synthesis involved in hypertensive myocardial fibrosis.
Animals↗
Serum beta 2-microglobulin and prediction of progression to AIDS in HIV-infected injection drug users.
Several immunological and serological variables have become established in recent studies as valuable markers to identify human immunodeficiency virus (HIV)-positive individuals at the highest risk for rapid disease progression. These studies have been performed mainly in cohorts of homosexual men. In this study, we assessed the usefulness of CD4 lymphocyte count, serum beta 2-microglobulin concentration, and the presence of p24 antigen as predictors of AIDS in a cohort of 130 HIV-positive injection drug users (IDUs) followed-up for 1 to 67 months. Progression to AIDS was most strongly associated with reduced absolute numbers of CD4+ lymphocytes at baseline, but increases in beta 2-microglobulin levels at baseline were an independent predictor of outcome. After stratification by baseline CD4 count, beta 2-microglobulin concentration added significant prognostic information to CD4 count among IDUs with > 500/mm3 CD4 cells (Breslow statistic value, 5.84, p = 0.01). Thus among seropositive IDUs with normal CD4 counts, increases in beta 2-microglobulin may be used as an early marker of individuals with higher risk of progression to AIDS, who may benefit from more intensive laboratory monitoring or clinical management.
AIDS-Related Opportunistic Infections↗