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Biomedical subjects

J Rodríguez

Publications and source records attributed to J Rodríguez.

At least 19 recordsLinked to original sources
PubMed1999

A modern human pattern of dental development in lower pleistocene hominids from Atapuerca-TD6 (Spain).

The study of life history evolution in hominids is crucial for the discernment of when and why humans have acquired our unique maturational pattern. Because the development of dentition is critically integrated into the life cycle in mammals, the determination of the time and pattern of dental development represents an appropriate method to infer changes in life history variables that occurred during hominid evolution. Here we present evidence derived from Lower Pleistocene human fossil remains recovered from the TD6 level (Aurora stratum) of the Gran Dolina site in the Sierra de Atapuerca, northern Spain. These hominids present a pattern of development similar to that of Homo sapiens, although some aspects (e.g., delayed M3 calcification) are not as derived as that of European populations and people of European origin. This evidence, taken together with the present knowledge of cranial capacity of these and other late Early Pleistocene hominids, supports the view that as early as 0.8 Ma at least one Homo species shared with modern humans a prolonged pattern of maturation.

Animals↗
PubMed1998

New Briarane Stecholide Diterpenes from the Indonesian Gorgonian Briareum sp.

The Indonesian gorgonian Briareum sp. has afforded two new briarane stecholide diterpenes: 2,9-diacetyl-2-debutyrylstecholide H (1) and 13-dehydroxystecholide J (2), the semisynthetic 2beta-acetoxy-2-(debutyryloxy)stecholide E acetate (3), which was isolated as a natural product for the first time, along with the known compounds stecholides I-M (4-8), stecholide A acetate (9), and stecholide C acetate (10). The structures of the new compounds were deduced by extensive NMR studies (1H, 13C, 1H-1H COSY, NOESY, HMQC, and HMBC) and FABMS data (HR and LR). Cytotoxic activity was found for the first time in stecholide L (7).

Journal Article↗
PubMed1998

Rat models of normocalcemic hypercalciuria of different pathogenic mechanisms.

Hypercalciuria was induced in female Sprague-Dawley rats, aged 40+/-2 days, by 7-day administration (mean+/-SEM) of calcitriol (5.4+/-0.1 ng/100 g per day, intraperitoneal), furosemide (14.9+/-1.9 mg/100 g per day, oral), or ammonium chloride (3.8+/-0.1 mEq/100 g per day, oral). Calciuria increased from 1.9+/-0.2, 1.6+/-0.2, and 1.9+/-0.3 to 5.4+/-0.5, 4.0+/-0.9, and 5.4+/-0.5 mg/100 g per day in the calcitriol (VD, n = 9), furosemide (F, n = 6), and ammonium chloride (AC, n = 10) groups, respectively. Calciuria did not change (1.9+/-0.3 vs. 1.6+/-0.1 mg/100 g per day) in control rats (n = 8). Ninety-six percent of treated rats became hypercalciuric as assessed by urine calcium excretion above the 90th percentile of normal values. Hypercalciuria was of similar degree in the three groups of rats and was not associated with hypercalcemia, metabolic acidosis, severe serum electrolyte imbalance, or growth impairment. VD rats had low serum parathyroid hormone (PTH) concentrations (3.0+/-0.5 pg/ml vs. 15.8+/-1.3 pg/ml in controls, P <0.05), whereas serum PTH was not significantly elevated in F rats (16.2+/-1.8 pg/ml). Thus, the protocol caused three forms of hypercalciuria that mimicked the clinical conditions of idiopathic hypercalciuria in humans and may clearly be differentiated according to their mechanism of production. This experimental model of normocalcemic hypercalciuria may be useful to clarify unknown aspects of pathogenesis and pathophysiology of idiopathic hypercalciuria in children.

Animals↗
PubMed1998

Comparison of the ligase chain reaction with solid and liquid culture media for routine detection of Mycobacterium tuberculosis in nonrespiratory specimens.

The aim of this study was to compare the results of a commercial assay based on the ligase chain reaction [(LCR) LCx Probe System MTB; Abbott, USA] with those of culture in liquid medium (Septi-Chek AFB; Becton-Dickinson, USA) and culture on the egg-based Löwenstein-Jensen solid medium for the direct detection of Mycobacterium tuberculosis complex in nonrespiratory specimens. The results were analyzed according to the standard definition of a true-positive result. Two hundred thirty-five nonrespiratory samples routinely submitted to rule out tuberculosis were analyzed. All samples were smear-negative. Mycobacterial growth in either culture medium was detected in 18 (7.6%) specimens: Mycobacterium tuberculosis was recovered from seven (38.9%) specimens cultured on Löwenstein-Jensen medium and from 18 (100%) specimens cultured in Septi-Chek AFB. The LCR protocol was positive in 22 specimens. None of the LCR-negative controls showed positive results. All samples positive by culture on Löwenstein-Jensen medium were positive by culture in liquid medium and by the LCR assay. However, Mycobacterium tuberculosis was detected by culture in liquid medium in two specimens that were negative by the LCR assay, whereas six specimens negative by culture in liquid medium were positive by the LCR protocol; three of these were identified as true-positive results of the LCR assay. The sensitivity, specificity, and positive and negative predictive values were 33.3%, 100%, 100%, and 93.8%, respectively, for Löwenstein-Jensen medium; 85.7%, 100%, 100%, and 98.6% for the liquid medium; and 90.4%, 98.5%, 86.3%, and 99% for the LCR assay. These findings indicate that the LCR assay may be a valid method of high diagnostic yield for direct detection of Mycobacterium tuberculosis complex in nonrespiratory specimens.

Body Fluids↗
PubMed1998

[Thyroid function and difficult to manage asthma].

Hyperthyroidism can cause asthma to worsen, such that analysis of thyroid function has been recommended when the course of asthma is unfavorable. The aim of this study was to determine whether systematic analysis of thyroid function is useful for all patients with difficult-to-manage asthma. For prospective study, we enrolled 48 asthmatics whose condition had deteriorated due to no known cause. All patients were studied as follows: a) all were assessed for thyrotropin (TSH) levels and, if alterations were detected, we ordered analysis of free thyroxin (FT4), and b) case histories were taken to rule out the existence of active thyroid disease. Nine patients (19%) were suspected of thyroid disease. TSH levels were abnormal in only 5 (10%) patients in this group (low in four and high in one). Hyperthyroidism was confirmed in only 3 patients (6%) after high FT4 levels were detected. Although the frequency of hyperthyroidism in the sample studied is higher than that described for the general population, the systematic investigation of thyroid dysfunction in all patients with difficult-to-manage asthma does not appear justified given that disease could be demonstrated in only some of those who were clinically suspected of thyroid disease.

Adult↗
PubMed1998

Effect of subcutaneous administration of octreotide on endogenous vasoactive systems and renal function in cirrhotic patients with ascites.

Splanchnic and systemic arteriolar vasodilation plays an important role in ascites formation in cirrhosis. Octreotide produces splanchnic vasoconstriction, but the effects on systemic hemodynamics and renal function are controversial. This study evaluated the effect of subcutaneous octreotide administration on systemic hemodynamics, endogenous vasoactive systems, and renal function in cirrhotic patients with ascites. Twenty patients were included: 10 received octreotide 250 microg/12 hr subcutaneously (for five days), and 10 did not. No statistically significant changes were found in mean arterial pressure and cardiac rate. Octreotide induced a statistically significant decrease in plasma renin activity (P < 0.01), plasma aldosterone (P = 0.01) and plasma glucagon (P < 0.05). No significant variations were observed in other systemic vasoactive substances (nitric oxide and prostacyclin). Renal function was not modified in either group. In conclusion, in cirrhotic patients with ascites, subcutaneous octreotide administration decreases plasma glucagon, renin activity, and aldosterone without changing in systemic hemodynamics or renal function.

Aldosterone↗
PubMed1998

Clinically prescribed sunscreen (sun protection factor 15) does not decrease serum vitamin D concentration sufficiently either to induce changes in parathyroid function or in metabolic markers.

Some studies have suggested that the use of sunscreens to prevent skin cancer may put the population at risk of vitamin D deficiency. We followed 24 sunscreen users and 19 controls over 2 years, including two summers, two winters and a basal period (winter). Vitamin D, parathormone and bone biological markers were evaluated each season. Mean levels of 25-hydroxyvitamin D rose in summer, with the increments being significantly higher for the second year in the control group. Levels decreased in winter in both groups, and were significantly lower in sunscreen users. We did not observe any significant change in parathormone, tartrate resistant phosphatase, total alkaline phosphatase, osteocalcin, urine hydroxyproline or urine calcium. Clinically prescribed sunscreen creams (sun protection factor 15) caused a minor decrease in 25-hydroxyvitamin D levels, which did not induce secondary hyperparathyroidism or an increment in bone biological markers.

Aged↗
PubMed1998

Interaction of IGF-I and 1 alpha, 25(OH)2D3 on receptor expression and growth stimulation in rat growth plate chondrocytes.

Growth plate cartilage cell express receptors for, and are affected by both IGF-I and 1 alpha, 25(OH)2D3. The studies were undertaken to investigate interaction between these two hormone systems, that is, (i) to study effects of 1 alpha, 25(OH)2D3 on IGF-type 1 receptors (IGFIR), on IGF-I stimulated cell replication, colony formation, and on alkaline phosphatase activity (AP), and conversely, (ii) to study the effect of IGF-I on vitamin D receptor (VDR) expression on 1 alpha, 25(OH)2D3 stimulated growth parameters and on AP activity. Freshly isolated rat tibial chondrocytes were grown in monolayer cultures, (serum-free) or in agarose stabilized suspension cultures (0.1% FCS). Vitamin D receptor and IGFIR were visualized by immunostaining with the monoclonal antibody (mAb) 9A7 gamma and mAb alpha IR3, respectively, and quantitated by RT-PCR for mRNA and by Scatchard analysis using [3H]-1,25(OH)2D3 and [125I]-alpha IR3. Cell proliferation was measured by [3H]-thymidine incorporation, growth curves in monolayer cultures, and by colony formation in agarose-stabilized suspension cultures. IGF-I dose-dependently increased [3H]-thymidine incorporation. 1 alpha, 25(OH)2D3, but not 1 beta, 25(OH)2D3 was stimulatory at low ((10-12 M) and slightly inhibitory at high (10-8 M) concentrations. The effect of IGF-I was additive to that of 1 alpha, 25 (OH)2D3 [IGF-I 60 ng/ml, 181 +/- 12.7; 1 alpha, 25(OH)2D3 10(-12) M, 181 +/- 9.8%, IGF-I + 1 alpha, 25(OH)2D3, 247 +/- 16.7%, P < 0.05 by ANOVA] and specifically obliterated by polyclonal IGF-I antibody (AB-1). Interaction could also be confirmed in suspension cultures. IGFIR mRNA and [125I]-alphaIR3 binding was increased by low (10(-12) m) but not by high (10(-8) M) concentrations of 1 alpha, 25(OH)2D3. Homologous up-regulation by IGF-I (60 ng/ml) was specifically inhibited by AB-1 and markedly amplified by coincubation with 1 alpha, 25(OH)2D3 (10(-12)m). Immunostaining with alpha IR3 showed specific IGFIR expression in rat growth cartilage, but not liver tissue. Stimulation of chondrocytes with 1 alpha, 25(OH)2D3 or IGF-I suggested some increase of receptor expression in single cells, but the predominant effect was increased recruitment of receptor positive cells, Vitamin D receptor expression was markedly stimulated (fourfold) by IGF-I (60 ng/ml), but not IGF-II and inhibited by actinomycin D. This study shows that IGF-I and 1 alpha, 25(OH)2D3 mutually up-regulate their respective receptors in growth plate chondrocytes. In parallel, they have additive effects on cell proliferation and colony formation suggesting independent effector pathways.

Animals↗
PubMed1998

Severe experimental uraemia does not decrease the population of rat pituitary somatotrophs.

BACKGROUND: Growth hormone (GH) secretion by the anterior pituitary has been shown to be depressed in severely uraemic rats. Changes in the population of pituitary somatotrophs might be partially responsible for this decrease. METHODS: To analyse the population of pituitary somatotrophs in severe uraemia, immunocytochemical detection and quantification of GH-producing cells were carried out on paraffin sections from young rats either 5/6 nephrectomized, sham-operated fed ad libitum or sham-operated pair-fed with the nephrectomized animals. RESULTS: Nephrectomized rats were severely uraemic and growth retarded. The overall cell density (total pituitary cells/mm2) was higher in 5/6 nephrectomized animals in comparison with the two sham-operated groups. Thus, although the percentage of GH cells was slightly lower in nephrectomized than in control rats, no difference in either the density (cells/mm2) or the cross-sectional area of GH cells was found among groups. CONCLUSIONS: These results suggest that severe experimental uraemia interferes with the maturation process of the pituitary gland and support the contention that differences in either the number or the size of pituitary somatotrophs cannot explain the reduced GH secretion previously reported in severely uraemic rats.

Animals↗
PubMed1998

[Uncommon neurologic complications related to varicella-zoster virus].

Neurological complications caused by varicella-zoster virus, excluding post-herpetic neuralgia and aseptic meningitis, are infrequent and varied. Other complications, which have been described are peripheral motor neuropathy, cranial nerve palsies, meningoencephalitis, Guillain-Barré syndrome, myelitis, herpes zoster ophthalmicus with delayed contralateral hemiparesis and Reye syndrome. We present 4 patients with infrequent neurological complications associated with varicella-zoster virus: 3 cases of meningoencephalitis and one case of myelitis.

Acyclovir↗
PubMed1998

[Serologic evaluation of treatment of chronic Chagas disease with allopurinol and itraconazole].

BACKGROUND: Chagas disease is endemic in Chile. Allopurinol and itraconazole have activity against Trypanosoma cruzi and are recommended for the treatment of chronic disease in adults. AIM: To evaluate the chemotherapeutic effects of allopurinol and itraconazole using conventional and non conventional serologic tests. PATIENTS AND METHODS: Sera of 90 patients with chronic Chagas disease were studied before and after 9 to 11 months of treatment with allopurinol or itraconazole and after two months of treatment with placebo. Indirect immunofluorescence, ELISA and Western Blot analysis were the conventional serologic tests used and antibody dependent complement mediated lysis (CoML) the non conventional test. RESULTS: There were no differences in ELISA and indirect immunofluorescence tests before and after therapy. Antigenic recognition profiles by Western Blot showed qualitative and quantitative differences in a small number of cases. CoML showed that the greater negativity was achieved in the Chagasic group treated with allopurinol or itraconazole that had a negative xenodiagnosis before drug treatment (35.8 and 61.6%, respectively). CONCLUSIONS: There is a reversion of lytic activity in sera of patients with negative xenodiagnosis before treatment, suggesting the parasitemia could be an important parameter to be considered in the chemotherapy of Chagas disease.

Adolescent↗
PubMed1998

[Report on the activity of the blood bank accreditation program (1987-1995)].

PURPOSE: To show the incidence of the deficiencies detected in the Blood Banks for the accreditation by the Transfusion Accreditation Committee (CAT), previously named PABAS. MATERIALS AND METHODS: Analysis of the reports of the accreditation of 85 Blood Banks made by the PABAS during the period 1987-1995. RESULTS: Eighty-five (20.8%) of the 407 Community Blood Centers, Hospital-Based Blood Banks and Transfusional Services of Spain had been surveyed. There were 244 deficiencies, of which 31 (12.7%) were of the equipment, 114 (46.7%) of the procedures used, and 99 (40.6%) of the documentation. The activities with more incidence of faults were: Control of the temperatures of the storage of units 53 (21.7%), label of the components 38 (15.5%), quality system of the institution surveyed 32 (13.1%), transfusional procedures 30 (12.3%), and on the procedure of the selection of donors 29 (11.9%). By contrary, the areas of work with fewer incidences of faults were those related with the collection of the blood and components 10 (4.1%) and the laboratory 14 (5.7%). CONCLUSIONS: Low percentage of the Community Blood Centers, Hospital-Based Blood Banks and Transfusional Services, which ask to be accredited by the Transfusion Accreditation Committee. The 83.7% of the errors detected are of the procedures and documentation, which could be easily corrected by the training and continuous improving of the quality, and without need of new inversions in equipment.

Accreditation↗
PubMed1998

[Presence of total coliforms, Escherichia coli and Listeria sp. in enteral formulas].

The presence of total coliforms, Escherichia coli and Listeria sp. was evaluated in 65 samples of enteral nutrition formulas. In more than the 75% of the samples made up from cooked vegetables, fruits or meat broth, the score level of total coliforms was of 10(4) UFC/g. In 12-31% of the different enteral food formula, E. coli was isolated in levels ranging form 3.0 x 10(2) to 2.1 x 10(4) UFC/g. Enteral nutrition formulas made out of fruits and those elaborated with meal broth presented this agent more frequently and in bigger quantities. Listeria sp. was isolated in 17% of the fruit preparations and in enteral formulas made with milk. L. grayi, L welshimeri and L. innocua were the species found.

Costa Rica↗
PubMed1998

[Central pontine myelinolysis associated with cyclosporin in liver transplantation].

Liver transplant is the only effective treatment in the terminal liver disease. However, the complexity of the surgical technique and immunosuppression cause many neurologic complications. Three liver transplant recipients treated with cyclosporine developed a reversible neurologic syndrome characterized by early dysarthria, which evolved to anarthria, and tetraparesis. Brain MRI disclosed hyperintense lesions, on T2, and proton density-weighted images, in basis pontis. The substitution of the cyclosporine for FK 506, or its reduction, led to the clinical improvement of the patients. Therefore, cyclosporine may cause central pontine myelinolysis, being dysarthria the first manifestation of neurotoxicity. The early recognition of speech disorders in liver transplant recipients that receive cyclosporine should prompt withdrawal of the drug to avoid possible neurological sequelae. Furthermore, the strict control of natremias before and after the transplant may help to reduce the incidence of this type of complications, since a synergyc osmotic mechanism cannot be ruled out.

Adult↗
PubMed1997

Comparison of MB-check and Löwenstein-Jensen media for recovery of mycobacteria.

We have compared the rate of recovery of mycobacteria with the MB-Check culture system (liquid phase) and the Löwenstein-Jensen (LJ) medium in 2,907 clinical specimens obtained from 830 patients submitted for mycobacterial culture during 1-year period. Direct smear examination was carried out by auramine-rhodamine staining. All primary isolates from the culture media were confirmed by Ziehl-Neelsen staining and identified by acridinium-ester-labeled DNA probes specific for Mycobaterium tuberculosis complex. A total of 214 isolates were of the M. tuberculosis complex (88 patients) and 54 of "potentially pathogenic environmental mycobacteria" (45 patients). A total of 117 (54.7%) samples were smear-positive and the remaining 97 (45.3%) were smear-negative. There was a significant difference in the percentage of positive cultures obtained by the MB-Check method (99.1%) as compared with the LJ medium (73.8%) (P < 0.05). This difference, however, occurred almost exclusively at the expense of the 97 smear-negative samples (positive cultures 97.95% by the MB-Check method vs. 42.3% by the LJ culture, P < 0.05). The number of patients diagnosed of tuberculosis by the MB-Check was significantly higher as compared with LJ medium (88 [100%] vs. 77 [87.5%], P < 0.05). In 11 (12.5%) patients, the diagnosis was only established by the MB-Check system. In smear-positive samples, the mean (+/-SD) detection time for M. tuberculosis complex was 14.8 +/- 8 days with MB-Check and 19.9 +/- 7 days with LJ medium. The corresponding figures in smear-negative samples were 22.8 +/- 3 days and 27.8 +/- 6 days, respectively. DNA probes directly applied to MB-Check liquid medium showed a sensitivity of 98.8% and specificity of 100%. These results indicate that the MB-Check system is more efficient for the recovery of mycobacteria than LJ medium.

Bacterial Typing Techniques↗