51
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Ryan JR, Vargas R, Clay GA, McMahon FG. Role of misoprostol in reducing aspirin-induced gastrointestinal blood loss in arthritic patients. Am J Med 1987; 83:41-6. [PMID: 3113245 DOI: 10.1016/0002-9343(87)90578-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Nonsteroidal anti-inflammatory drugs are used to control pain and inflammation in arthritic disorders. When used at recommended anti-inflammatory dose levels, however, they often produce injury to the gastric and duodenal mucosa and concomitant blood loss. A double-blind, parallel, placebo-controlled study was conducted to assess the effectiveness of misoprostol, a synthetic analogue of prostaglandin E1, in preventing gastrointestinal blood loss induced by acetylsalicylic acid in patients with degenerative joint disease. Forty-five arthritic patients (22 women and 23 men) were admitted to the study. All patients had received treatment with 3,900 mg of acetylsalicylic acid per day in four divided doses for at least two weeks and continued to receive that regimen for the duration of the study. Red blood cells were tagged with chromium-51, and fecal blood loss was determined from Days 4 to 7. Patients with a mean blood loss of at least 1.5 ml per day were randomly allocated to receive either placebo or 200 micrograms of misoprostol four times daily for seven days. Fecal blood loss was measured daily, and the results were compared with baseline determinations. Of 41 patients who completed the study, 19 were treated with misoprostol. Of these, 11 patients (57.9 percent) had at least a 50 percent reduction in blood loss. Of 22 patients receiving placebo, only one had a 50 percent reduction in blood loss (p = 0.003; Fisher's exact test). Mean blood loss in patients using misoprostol was reduced from 3.65 +/- 2.51 to 1.57 +/- 0.86 ml per day, whereas among those taking placebo, mean blood loss did not significantly change (2.98 +/- 1.24 to 2.79 +/- 1.63 ml per day). The difference in blood loss between the misoprostol and placebo groups was significant (p = 0.0023; Wilcoxon test). In those patients who completed the study, no significant changes were detected on laboratory tests. In conclusion, misoprostol effectively reduced fecal blood loss in arthritic patients treated with acetylsalicylic acid.
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Clinical Trial |
38 |
18 |
52
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Vollmer M, Jeck N, Lemmink HH, Vargas R, Feldmann D, Konrad M, Beekmann F, van Den Heuvel LP, Deschenes G, Guay-Woodford LM, Antignac C, Seyberth HW, Hildebrandt F, Knoers NV. Antenatal Bartter syndrome with sensorineural deafness: refinement of the locus on chromosome 1p31. Nephrol Dial Transplant 2000; 15:970-4. [PMID: 10862633 DOI: 10.1093/ndt/15.7.970] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Recently a locus for antenatal Bartter syndrome associated with sensorineural deafness was mapped to human chromosome 1p31 in a single consanguineous Bedouin family (Brennan et al. Am J Hum Genet 1998; 62: 355-361). METHODS By haplotype analysis we demonstrate linkage to this locus in nine consanguineous families with antenatal Bartter syndrome associated with sensorineural deafness. RESULTS The critical interval compatible with linkage was refined to 4.0 cM by two novel recombinational events with markers D1S2661 and D1S475. CONCLUSION We thereby confirmed this gene locus and distinguished this clinical subtype from other variants of Bartter syndrome as a new disease entity.
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25 |
18 |
53
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Thomas G, Vargas R, Wroblewska B, Ramwell PW. Role of the endothelium and arginine peptides on the vaso-motor response of porcine internal mammary artery. Life Sci 1989; 44:1823-30. [PMID: 2544772 DOI: 10.1016/0024-3205(89)90299-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The long-term patency of the internal mammary artery (IMA) graft is of considerable interest owing to its extensive use in myocardial revascularization. The aim of the present study was to elucidate the role of endothelium in modulating the responses of the porcine IMA to several vasoactive drugs. Isolated ring segments of porcine IMA contracted in a reproducible and dose dependent manner to phenylephrine, potassium chloride and the thromboxane mimic U46619, but the responses to serotonin, histamine and ATP were significantly less prominent. Both acetylcholine and bradykinin elicited endothelium-dependent relaxation which was not inhibited by indomethacin, but by methylene blue, an inhibitor of soluble guanylate cyclase. These two endothelium-dependent drugs and two endothelium-independent relaxing drugs, nitroprusside and nitroglycerin relaxed the IMA in a dose dependent manner which was associated with an elevation of cyclic GMP. The endothelium dependent vasodilator peptides such as bradykinin contain L-arginine in their sequence. Benzoyl derivatives of L-arginine but not L-arginine relaxed the IMA in a dose dependent manner. These data confirm and extend exploratory studies performed with a simpler vascular model which indicate that the precursor of endothelium derived relaxing factor (EDRF) is an arginine moiety.
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36 |
18 |
54
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Vugia DJ, Rodriguez M, Vargas R, Ricse C, Ocampo C, Llaque R, Seminario JL, Greene KD, Tauxe RV, Blake PA. Epidemic cholera in Trujillo, Peru 1992: utility of a clinical case definition and shift in Vibrio cholerae O1 serotype. Am J Trop Med Hyg 1994; 50:566-9. [PMID: 8203704 DOI: 10.4269/ajtmh.1994.50.566] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Epidemic cholera continues in Peru. Since 1991, cholera surveillance in Peru has been based mainly on clinical recognition. To determine the proportion of reported cholera patients who actually have cholera and to evaluate the clinical case definition used in surveillance, we cultured rectal swabs from patients presenting with acute diarrhea in March 1992 in Trujillo, Peru. Of 197 patients meeting the clinical case definition, 174 (88%) had confirmed Vibrio cholerae O1 infection. In this epidemic setting, watery diarrhea of sudden onset in a person of any age presenting for treatment is highly predictive of cholera. Of note, 90% of the current V. cholerae O1 El Tor isolates were of serotype Ogawa, while a year earlier, all were of serotype Inaba.
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31 |
17 |
55
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Vargas R, Castañeda M. Role of elongation factor 1 in the translational control of rodent brain protein synthesis. J Neurochem 1981; 37:687-94. [PMID: 6912278 DOI: 10.1111/j.1471-4159.1982.tb12542.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The translational control of protein synthesis during early postnatal neural development and aging was examined in the mouse and the rat. The activity of brain elongation factor 1 (bEF-1) was found to decrease exponentially with age and to decline parallel to the age-dependent decrease in total protein synthesis in both rodents. This decrement in bEF-1 activity fell within the range of reported age-related decreases in protein synthesis in in vitro systems. The factor was present in multiple forms; the lighter species predominated in older animals, whereas the young light form apparently disappeared with increasing age, and was replaced by other arising from the heavy form. Elongation factor 1 derived from young brains functioned as a rate-limiting component in polypeptide synthesis in previously saturated adult systems. The data suggest that bEF-1 has an important modulatory effect on total brain protein synthesis.
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44 |
17 |
56
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Guay DR, Opsahl JA, McMahon FG, Vargas R, Matzke GR, Flor S. Safety and pharmacokinetics of multiple doses of intravenous ofloxacin in healthy volunteers. Antimicrob Agents Chemother 1992; 36:308-12. [PMID: 1605596 PMCID: PMC188432 DOI: 10.1128/aac.36.2.308] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The safety and pharmacokinetics of ofloxacin in 48 healthy male volunteers were studied in a two-center, randomized, double-blind, placebo-controlled study. Ofloxacin (200 or 400 mg) or placebo was administered as 1-h infusions every 12 h for 7 days. Plasma ofloxacin concentrations were measured by high-performance liquid chromatography. Mean harmonic half-lives ranged from 4.28 to 4.98 h in the 200-mg dosing group and from 5.06 to 6.67 h in the 400-mg dosing group. Intragroup comparisons of trough plasma concentration-versus-time data from study days 2 through 7 revealed that steady state was achieved by day 2 of both multiple-dose regimens. Intergroup comparisons of mean harmonic half-lives, the areas under the concentration-time curve from 0 to 12 and 0 to 60 h, clearance, and apparent volume of distribution (area method) revealed that the pharmacokinetics of ofloxacin are dose independent. Both ofloxacin dosage regimens appeared to be reasonably well tolerated. The two dosage regimens of ofloxacin, 200 or 400 mg every 12 h, appear to be safe and provide serum drug concentrations in excess of the MICs for most susceptible pathogens over the entire dosing interval.
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research-article |
33 |
17 |
57
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Vargas R, Thorsteinsson H, Karlsson KAE. Spontaneous neural activity of the anterodorsal lobe and entopeduncular nucleus in adult zebrafish: a putative homologue of hippocampal sharp waves. Behav Brain Res 2011; 229:10-20. [PMID: 22207154 DOI: 10.1016/j.bbr.2011.12.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 12/12/2011] [Accepted: 12/14/2011] [Indexed: 10/14/2022]
Abstract
Spontaneous neural activity is instrumental in the formation and maintenance of neural circuits that govern behavior. In mammals, spontaneous activity is observed in the spinal cord, brainstem, diencephalon, and neocortex, and has been most extensively studied in the hippocampus. Using whole-brain in vitro recordings we establish the presence of spontaneous activity in two regions of the zebrafish telenchephalon: the entopeduncular nucleus (EN) and the anterodorsal lobe (ADL). The ADL is part of the lateral telencephalic pallium, an area hypothesized to be functionally equivalent to the mammalian hippocampus. In contrast, the EN has been hypothesized to be equivalent to the mammalian basal ganglia. The observed spontaneous activity is GABA modulated, sensitive to glutamate and chloride transporter antagonists, and is abolished by sodium pump blockers; moreover, the spontaneous activity in the ADL is a slow multiband event (∼100 ms) characterized by an embedded fast ripple wave (∼150-180 Hz). Thus, the spontaneous activity in the ADL shares physiological features of hippocampal sharp waves in rodents. We suggest that this spontaneous activity is important for the formation and maintenance of neural circuits in zebrafish and argue that applying techniques unique to the fish may open novel routes to understand the function of spontaneous activity in mammals.
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Research Support, Non-U.S. Gov't |
14 |
17 |
58
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Boinet T, Bourgois J, Mendoza H, Vargas R. Le poincon de Pamplona (Colombie); un jalon de la frontiere meridionale de la plaque caraibe. ACTA ACUST UNITED AC 1985. [DOI: 10.2113/gssgfbull.i.3.403] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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40 |
17 |
59
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Perez Gutierrez RM, Ramirez E, Vargas R. Effect of Cirsium pascuarense on blood glucose levels of normoglycaemic and alloxan-diabetic mice. Phytother Res 2001; 15:552-4. [PMID: 11536391 DOI: 10.1002/ptr.882] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Blood glucose levels of normal and alloxan-treated diabetic mice were determined after i.p. administration of various doses of the hexane, chloroform and methanol extracts of Cirsium pascuarense. From the data obtained, it is concluded that the i.p. administration of 100, 150 and 200 mg/kg of hexane extract of this plant produced a significant hypoglycaemic effect in normal as well as in diabetic mice. In addition, the extracts altered glucose tolerance in alloxan induced diabetic rats. Chloroform and methanol extracts did not produce any significant change in blood glucose levels.
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Comparative Study |
24 |
16 |
60
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Vargas R, Garza J, Vela A. Strongly convergent method to solve one-dimensional quantum problems. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 1996; 53:1954-1963. [PMID: 9964458 DOI: 10.1103/physreve.53.1954] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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29 |
15 |
61
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Hernandez DE, Morgenstern J, Weiss E, Planas G, Ruiz A, Olavarria R, Tapia F, Muci R, Vargas R, Wuani H. Cutaneous lesions of disseminated histoplasmosis in a Haitian man with the acquired immunodeficiency syndrome. Int J Dermatol 1986; 25:117-8. [PMID: 3699954 DOI: 10.1111/j.1365-4362.1986.tb04553.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Case Reports |
39 |
15 |
62
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Abstract
Nabumetone, a nonsteroidal anti-inflammatory drug of the naphthylalkanone class, was studied in an open-label fashion to compare the relative single-dose and steady-state kinetics in young healthy male volunteers and in elderly patients with degenerative joint disease. Seventeen healthy male volunteers 21 to 30 years of age and 17 patients 60 to 75 years of age were studied. After a single oral dose of 1,000 mg nabumetone, blood and urine samples were collected over a five-day period. Plasma was assayed for nabumetone and the active metabolite, 6-methoxynaphthylacetic acid, and the urine was assayed for five metabolites. Following this phase, they received daily oral doses of 1,000 mg nabumetone for 14 days. After the final dose, blood and urine samples were again collected for five days for the same assays. These data were fitted to a single compartment model and the derived data are as follows: mean maximal plasma concentration, maximal time concentration, area under the plasma-time curve, elimination rate constant, and elimination half-life in the young group after single dose were 22.9, 8.4, 838, 0.032, and 21.2, respectively, whereas on steady-state, values were 33.6, 4.1, 666, 0.031, and 22.1, respectively. In the elderly group after single dose, these values were 30.2, 10.8, 1,538, 0.024, and 29.2, whereas on steady-state, they were 50.0, 7.2, 1,092, 0.027, and 25.6. The accumulation ratio was 1.6 in the young and 1.8 in the elderly. Side effects in the young were mild and consistent of headaches, epigastric discomfort, nausea, and vomiting, whereas in the elderly they consisted mainly of headaches. No significant changes in complete blood cell count, blood chemistries, or urinalysis were noted. We concluded from these data that the drug does not accumulate if given every 24 hours; therefore, a single daily dose should provide sufficient therapy and that due to a difference in elimination, elderly patients may require a lower dose.
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38 |
15 |
63
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Vargas R, Balasch JC, Brandts I, Reyes-López F, Tort L, Teles M. Variations in the immune and metabolic response of proactive and reactive Sparus aurata under stimulation with Vibrio anguillarum vaccine. Sci Rep 2018; 8:17352. [PMID: 30478379 PMCID: PMC6255872 DOI: 10.1038/s41598-018-35863-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 11/09/2018] [Indexed: 12/17/2022] Open
Abstract
Environmental insults, such as exposure to pathogens, modulate the behavioural coping style of animals to stressors, and repeated exposure to stressful environments may lead to species-specific infection phenotypes. To analyse the influence of stress behavioural phenotypes on immune and metabolic performance, gilthead sea bream (Sparus aurata L.) were first screened for proactive and reactive coping styles. Once characterized, both behavioural phenotypes fish groups were bath vaccinated with bacterin from Vibrio anguillarum, an opportunistic widespread pathogen of fish. Gills and liver were sampled at 0 (control group), 1, 3 and 7 days post-vaccination. Immune-, oxidative stress- and metabolic-related transcripts (il1β, tnfα, igm, gpx1, sod, cat, lpl, ghr1 and ghr2), metabolic endpoints (glucose, cholesterol and triglycerides), hepatic health indicators (aspartate aminotransferase, alanine transaminase and alkaline phosphatase), oxidative stress status (esterase activity, total antioxidant capacity and total oxidative status) and stress biomarkers (cortisol) were determined. Present results indicate that screening for coping styles in the gilthead sea bream segregated the two distinct phenotypes as expected: proactive and reactive. Results also indicate that under bath vaccination proactive fish show high immune response and lower metabolism, whereas reactive fish show low immune and higher metabolic responses.
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Research Support, Non-U.S. Gov't |
7 |
15 |
64
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Dunn DW, Daum RS, Weisberg L, Vargas R. Ischemic cerebrovascular complications of Haemophilus influenzae meningitis. The value of computed tomography. ARCHIVES OF NEUROLOGY 1982; 39:650-2. [PMID: 7125976 DOI: 10.1001/archneur.1982.00510220048011] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
In an effort to define the value of computed tomographic (CT) scanning in assessment of cerebral involvement in children with severe Haemophilus influenzae meningitis, we studied 12 children who had focal neurologic deficits on admission or within the early days of illness. The CT scan reliably excluded abscess and cerebritis and suggested ischemic cerebrovascular lesions in 11 of 12 children. Scans performed early in the hospital course generally showed low-density lesions occurring in a vascular distribution without detectable mass effect or enhancement. Later in the clinical course there was consistent enhancement of gray matter or diffuse enhancement in the area of the vascular lesion. The duration of symptoms of meningitis ranged from five to 21 days (mean, 13 days) and appeared to predispose to these vascular lesions. A CT scan consistent with infarction of brain parenchyma occurred predictably in patients with persistent focal neurologic deficits and was correlated with poor outcome.
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43 |
15 |
65
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Vargas R, Jóhannesdóttir IT, Sigurgeirsson B, Thorsteinsson H, Karlsson KAE. The zebrafish brain in research and teaching: a simple in vivo and in vitro model for the study of spontaneous neural activity. ADVANCES IN PHYSIOLOGY EDUCATION 2011; 35:188-196. [PMID: 21652504 DOI: 10.1152/advan.00099.2010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Recently, the zebrafish (Danio rerio) has been established as a key animal model in neuroscience. Behavioral, genetic, and immunohistochemical techniques have been used to describe the connectivity of diverse neural circuits. However, few studies have used zebrafish to understand the function of cerebral structures or to study neural circuits. Information about the techniques used to obtain a workable preparation is not readily available. Here, we describe a complete protocol for obtaining in vitro and in vivo zebrafish brain preparations. In addition, we performed extracellular recordings in the whole brain, brain slices, and immobilized nonanesthetized larval zebrafish to evaluate the viability of the tissue. Each type of preparation can be used to detect spontaneous activity, to determine patterns of activity in specific brain areas with unknown functions, or to assess the functional roles of different neuronal groups during brain development in zebrafish. The technique described offers a guide that will provide innovative and broad opportunities to beginner students and researchers who are interested in the functional analysis of neuronal activity, plasticity, and neural development in the zebrafish brain.
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14 |
14 |
66
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Jain AK, Ryan JR, Vargas R, McMahon FG. Efficacy and acceptability of different dosage schedules of clonidine. Clin Pharmacol Ther 1977; 21:382-7. [PMID: 849670 DOI: 10.1002/cpt1977214382] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In 12 hospitalized patients with hypertension, clonidine 3 times a day led to better control of blood pressure than did the same total dose administered once daily. Compared to the uniform control of blood pressure on divided dose regimen, the single daily 8 P.M. dose led to wider fluctuations and inadequate control 18 hr after dosing. However, 10 of the 12 patients preferred the single daily dose at 8:00 P.M. to the divided dose regimen because of no drowsiness during the day. In 2 patients administration of clonidine twice daily resulted in better control of blood pressure than that during the single or thrice-daily dose regimens. Since there appeared to be a correlation between the dose and the duration of adequate blood pressure control, administration of clonidine twice a day with a larger dose at bedtime and a smaller dose before noon could limit unwanted drowsiness and combine the convenience of less frequent dosing with superior blood pressure control.
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Comparative Study |
48 |
14 |
67
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Heatherington A, Oon SM, Vargas R, Kane-Maguire N. Acid hydrolysis and linkage isomerism of the cis-dicyanobis(ethylenediamine)chromium(III) ion. Inorganica Chim Acta 1980. [DOI: 10.1016/s0020-1693(00)91035-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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45 |
13 |
68
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Castañeda M, Vargas R, Galván SC. Stagewise decline in the activity of brain protein synthesis factors and relationship between this decline and longevity in two rodent species. Mech Ageing Dev 1986; 36:197-210. [PMID: 3784632 DOI: 10.1016/0047-6374(86)90020-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The activities of brain initiation factor 2 and brain elongation factor 1, which function as rate-limiting in total protein synthesis, and estimations of brain weight were followed during postnatal life in the rat and the mouse. Both activities decreased in parallel while cumulative brain weight increased. Three exponential components were required for the mathematical expression of each of the three processes in semilogarithmic plots against time. The acceleration curves for the activities and tissue weight demonstrated a mirror image symmetry. Within the general pattern of diminution with age, the negative acceleration of the activities and the positive acceleration of the brain weight displayed repeated bursts. The activities of both factors could also be arranged into several regression lines in log/log plots against time. Significantly, in these plots, the regression line calculated for the whole set of data for each factor activity showed that the value of the ratio of the slopes (mouse to rat) was inversely related to the square root of the ratio of species longevity and was in agreement with the power law relating life spans of cells to species longevity (Röhme, Proc. Natl. Acad. Sci. U.S.A., 78 (1981) 5009).
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39 |
12 |
69
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Vargas R, Cifuentes F, Morales M. Role of presynaptic and postsynaptic IP3-dependent intracellular calcium release in long-term potentiation in sympathetic ganglion of the rat. Synapse 2010; 65:441-8. [DOI: 10.1002/syn.20862] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2010] [Accepted: 08/16/2010] [Indexed: 01/21/2023]
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15 |
12 |
70
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Ryan JR, Riley WA, Vargas R, Offen WW, Gruber CM. Enteric coating of fenoprofen calcium reduces gastrointestinal microbleeding. Clin Pharmacol Ther 1987; 42:28-32. [PMID: 3496186 DOI: 10.1038/clpt.1987.103] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The effects of plain and enteric-coated fenoprofen calcium (Nalfon, Dista, Indianapolis, Ind.) on gastrointestinal microbleeding were studied in 32 normal male volunteers in a randomized, open-label, parallel trial at two inpatient research facilities. A 1-week placebo (baseline) period preceded 2 weeks of fenoprofen therapy (enteric coated or plain, 600 mg q.i.d.). Fecal blood loss was measured by 51Cr-tagged erythrocyte assay and averaged over days 4 to 7 (baseline) and 11 to 14 and 18 to 21 (active therapy). At one center gastrointestinal irritation was evaluated endoscopically before and after active therapy. Endoscopy showed both formulations to cause mucosal damage not evident by subject-reported symptoms. Four of the 16 subjects developed asymptomatic duodenal ulcers. Mean daily fecal blood loss was significantly lower (P = 0.03) with enteric-coated (mean +/- SD, 1.104 +/- 0.961 ml/day) than with plain fenoprofen calcium (mean +/- SD, 1.686 +/- 0.858 ml/day), suggesting that tolerance of fenoprofen can be improved with administration in an enteric-coated form.
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Clinical Trial |
38 |
11 |
71
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Vargas R, Cifuentes F, Morales MA. Differential contribution of extracellular and intracellular calcium sources to basal transmission and long-term potentiation in the sympathetic ganglion of the rat. Dev Neurobiol 2007; 67:589-602. [PMID: 17443810 DOI: 10.1002/dneu.20364] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Calcium involved in basal ganglionic transmission and long-term potentiation (LTP) can arise either by influx from the extracellular medium or release from intracellular stores. No attempts have yet been made to concurrently explore the contributions of extracellular and intracellular Ca2+ to basal ganglionic transmission or LTP. Here, we investigate this subject using the superior cervical ganglion of the rat. To explore the extracellular Ca2+ contribution, we evaluated basal transmission and LTP at different extracellular Ca2+ concentrations. To assess intracellular Ca2+ release, we explored the contribution of the calcium-induced calcium release process by overactivation or blockade of ryanodine-sensitive Ca2+ receptor channel with caffeine, and also by blocking either IP3R with Xestospongin C or the sarco(endo)plasmic reticulum Ca2+-ATPase pump with thapsigargin. Extracellular Ca2+ affected ganglionic basal transmission and LTP to different extents. While 25% of the physiological Ca2+ concentration supported 80% of basal transmission, 50% of normal Ca2+ was required to achieve 80% of LTP. Notably, disruption of intracellular Ca2+ release by all the drugs tested apparently did not affect basal ganglionic transmission but impaired LTP. We conclude that basal transmission requires only a small level of Ca2+ entry, while LTP expression not only requires more Ca2+ entry but is also dependent on Ca2+ release from intracellular stores.
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Research Support, Non-U.S. Gov't |
18 |
11 |
72
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Vargas R, Mackenzie S, Rey S. 'Love at first sight': The effect of personality and colouration patterns in the reproductive success of zebrafish (Danio rerio). PLoS One 2018; 13:e0203320. [PMID: 30231039 PMCID: PMC6145548 DOI: 10.1371/journal.pone.0203320] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 08/17/2018] [Indexed: 01/07/2023] Open
Abstract
Individual differences in animal personality and external appearance such as colouration patterns have both been extensively studied separately. A significant body of research has explored many of pertinent ecological and biological aspects that can be affected by them and their impact upon fitness. Currently little is known about how both factors interact and their effect on reproductive success. In this study, we evaluated two major parameters contributing to the fitness of the species: reproduction and offspring survival. We selected two different phenotypes of the zebrafish (Danio rerio) selected by their colouration patterns: phenotype 1) named Wild type, UAB line (WT-UAB) with a homogeneous colouration pattern (clear and defined lateral stripes) and phenotype 2) Wild type indefinite (WT-I) had a heterogeneous colouration pattern and different degrees of lateral stripe definition. All animals were also screened for personality. We then compared their reproductive success (spawning rate) and offspring survival at different stages, from egg to larvae, and for 2 successive generations (parental generation was G0; First and second generations were G1 and G2 respectively). Our results show that personality traits were the main source of variability between the fitness components measured: both personalities had similar total numbers of eggs spawned but proactive animals, for both colour phenotypes, had higher reproductive success. This was reflected in a higher percentage of spawning viability at 1day post fertilization (dpf), higher total survival and growth rates at larval stages. Proactive phenotypes from WT-UAB population had a higher overall fitness in comparison to the other phenotypes studied. Our findings imply that fitness of this species when kept under similar husbandry conditions is significantly influenced by parental personality and not by their external appearance. Under these conditions the reproductive success is enhanced. The implications of this study are important for zebrafish breeding and husbandry in captivity and are relevant toward understanding the underlying drivers of trait selection in natural environments.
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research-article |
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Imarai CM, Rocha A, Acuña C, Garrido J, Vargas R, Cardenas H. Endocytosis and MHC class II expression by human oviductal epithelium according to stage of the menstrual cycle. Hum Reprod 1998; 13:1163-8. [PMID: 9647540 DOI: 10.1093/humrep/13.5.1163] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The epithelium is the first barrier against pathogens invading the lumen of the human oviduct. Its expression of class II major histocompatibility complex (MHC class II) proteins suggests that it might play a role in antigen presentation during the local immune response. To study the role of the oviductal epithelium in antigen processing, its endocytic properties and MHC class II expression were examined. For assay of endocytosis, fluorescein isothiocyanate-labelled bovine serum albumin (BSA-FITC) or Escherichia coli (E. coli-FITC) was infused into the lumen. One-centimetre pieces of oviduct were incubated for 2 h and processed for fluorescence and confocal microscopy, and transmission electron microscopy. Incorporation into secretory and ciliated epithelial cells was observed, which was unrelated to the phase of the menstrual cycle. Small pieces of the organs were frozen and processed for immunohistochemistry. Most oviducts expressed MHC class II (HLA.DR) in the epithelium and in some cases this was coincident with endocytosis, but there was no statistically significant association between this expression and either endocytotic activity or the phase of the menstrual cycle. Results demonstrate that the epithelium of the human oviduct exhibits endocytic properties towards luminal soluble and particle antigens, which is not related either to MHC class II expression or to the phase of the menstrual cycle.
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Panza SB, Vargas R, Balbo SL, Bonfleur ML, Granzotto DCT, Sant'Ana DMG, Nogueira-Melo GA. Perinatal exposure to low doses of glyphosate-based herbicide combined with a high-fat diet in adulthood causes changes in the jejunums of mice. Life Sci 2021; 275:119350. [PMID: 33737081 DOI: 10.1016/j.lfs.2021.119350] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 03/05/2021] [Accepted: 03/08/2021] [Indexed: 12/12/2022]
Abstract
AIM Exposure to pesticides and consumption of high-fat diets are widespread in society. Reports have shown that exposure to glyphosate and a high-fat diet can cause gastrointestinal disorders and increase susceptibility to obesity. Thus, this study evaluated the impacts of perinatal exposure to glyphosate followed by consumption of a high-fat diet in adulthood on the histology and morphometry of jejunums and enteric nervous system of C57BL/6 mice. MATERIAL AND METHODS After mating, 20 C57BL/6 female mice were separated into a control group (CG) and a glyphosate group (GLY) that received water with 0.5% glyphosate. After the lactation period, some male offspring were randomly separated into CG-SD and GLY-SD (standard diet) groups or CG-HD and GLY-HD (high-fat diet) groups. After 12 weeks, jejunum samples were collected and submitted to histological analysis. KEY FINDINGS Indirect exposure to glyphosate changed the morphometry of the intestinal wall, increased the proportion of intraepithelial lymphocytes (IELs) and goblet cells, and altered the area occupied by collagen fibers. The hyperlipidemic diet hypertrophied the jejunal total wall, total muscular and submucosal layers, decreased IELs, and increased the proportion of goblet cells. GLY-HD mice had shallower crypts, shorter villi, and less goblet cells and IELs than mice from GLY-SD group. GLY-HD also showed an increased number of neurons in myenteric and submucosal plexuses. Groups exposed to glyphosate and/or fed a high-fat diet had atrophied submucosal neurons. SIGNIFICANCE This study suggests that perinatal glyphosate exposure combined with a high-fat diet in adulthood increases the risk of jejunum inflammation and dysfunction.
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Vargas R, Neggers J, Canto R, Rodrigues J, Hild F. Analysis of a castable refractory using the wedge splitting test and cohesive zone model. Ann Ital Chir 2019. [DOI: 10.1016/j.jeurceramsoc.2019.03.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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