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Biomedical subjects

J Rodríguez

Publications and source records attributed to J Rodríguez.

At least 145 records · Page 8Linked to original sources
PubMed1995

Jasplakinolide's inhibition of the growth of prostate carcinoma cells in vitro with disruption of the actin cytoskeleton.

BACKGROUND: Jasplakinolide, a cyclodepsipeptide produced by an Indo-Pacific sponge, Jaspis johnstoni, has been reported to inhibit the growth of breast cancer cells. PURPOSE: The effects of jasplakinolide on the proliferation of three human immortalized prostate carcinoma cell lines (PC-3, LNCaP, and TSU-Pr1) were studied. The growth-inhibitory effect of jasplakinolide on the PC-3 cell line was studied in detail to elucidate its mechanism of action. METHODS: Cell counts were used to study growth inhibition. A protein-based microplate assay was used to assess the time of exposure needed to cause persistent growth inhibition and to study the effects of jasplakinolide analogues. Metabolic changes were assessed by following the incorporation of radiolabeled precursors. The effects of jasplakinolide on the cytoskeleton were studied by fluorescent microscopy, using rhodamine phalloidin (RP) and antibodies to cytoskeletal components. Changes in RP binding were quantified by extracting bound fluorescent material from fixed cells and measuring the amount of fluorescence in a spectrofluorometer. RESULTS: The growth of PC-3, LNCaP, and TSU-Pr1 cells was potently inhibited by exposure to jasplakinolide for 48 hours; doses of jasplakinolide that led to 50% growth inhibition were 65 nM for PC-3 cells, 41 nM for LNCaP cells, and 170 nM for TSU-Pr1 cells. In PC-3 cells, exposure to 160 nM for 48 hours led to total growth inhibition, which persisted for several days even after drug removal. Several jasplakinolide analogues also inhibited the growth of PC-3 cells, although analogues in which the rigidity of the macrolide ring was altered were ineffective. No early changes in the synthesis of DNA, RNA, or protein or in intracellular adenosine triphosphate levels were seen in the PC-3 cells after exposure to jasplakinolide. Growth inhibition by jasplakinolide was accompanied by striking morphologic changes. Exposure for several doublings led to multinucleated cells. Further investigation of these changes in the PC-3 cells revealed a dramatic and early disruption of the actin cytoskeleton and a statistically significant decrease in RP binding. The doses of jasplakinolide, the time of exposure, and the pattern of growth inhibition by structural analogues corresponded with the changes seen in actin distribution. CONCLUSIONS: Jasplakinolide represents a novel marine natural product with potent in vitro antiproliferative activity against human prostate carcinoma cell lines, and it appears to target the actin cytoskeleton. IMPLICATIONS: Jasplakinolide is a potential candidate for further preclinical development and a lead structure for a novel class of therapeutic agents that can disrupt the actin cytoskeleton in mammalian cells.

Actins↗
PubMed1995

Experimental model for local administration of nerve growth factor in microsurgical nerve reconnections.

An experimental model for local administration of neuronotrophic substances at the site of peripheral nerve lesion is presented. The model consists of a subcutaneously located silicone reservoir and a connecting tube with its distal end fixed in the proximity of the severed and repaired nerve. The results of the preliminary tests of the model are presented. Sixty Sprague-Dawley rats were divided into two groups: control (saline-treated) (n = 30) and NGF-treated (n = 30). After axotomy of the sciatic nerve, an epineurial repair is performed. NGF or saline is injected daily into the subcutaneous reservoir during the first 3 weeks after axotomy and a single dose in the fourth week. The regenerated nerve observed in the NGF-treated group after four weeks of treatment presents a greater percentage of myelinated axons, thicker myeline sheaths, and more mature endoneurial layers. This experimental model provides a reliable and quantitative way to deliver neuronotrophic substances in site and at different administration rates.

Animals↗
PubMed1995

Bradycardia and asystole following atropine-neostigmine administration after caesarean section in a parturient receiving methyldopa for pregnancy-induced hypertension.

We report one case of bradycardia and asystole immediately after the administration of 1 mg atropine and 2 mg neostigmine after the completion of an urgent caesarean section. We attribute this adverse reaction to the treatment of pregnancy-induced hypertension with methyldopa, perhaps facilitated by other drugs employed. Similar reactions have been reported relating to beta-receptor antagonists and tricyclic antidepressants, but not to methyldopa.

Journal Article↗
PubMed1995

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

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

Axilla↗
PubMed1995

A gonadotrophin dependent stromal luteoma: a rare cause of post-menopausal virilization.

A stromal luteoma is an uncommon ovarian tumour in post-menopausal women, which presents rarely with hyperandrogenism and virilization. We present the case of a 64-year-old woman referred for evaluation of virilization which had developed over 5 years. Testosterone, FSH and LH were markedly inhibited following the administration of a GnRH analogue, suggesting a gonadotrophin dependent, testosterone secreting ovarian tumour, which could not be localized with imaging techniques. Surgery revealed normal sized ovaries with no apparent lesions, but microscopic examination showed a small stromal luteoma in the right ovary and severe stromal hyperthecosis in the adjacent and contralateral ovarian stroma. We conclude that stromal luteoma is an uncommon cause of virilization in post-menopausal women. This case illustrates, to our knowledge for the first time, that a stromal luteoma is not autonomous but is gonadotrophin dependent.

Depression, Chemical↗
PubMed1995

Purification and properties of a chitinase from Penicillium oxalicum autolysates.

A chitinase (EC. 3.2.1.14) from autolysed culture filtrate of Penicillium oxalicum was purified by precipitation with ammonium sulphate, gel filtration and ion exchange chromatographies. The purified enzyme showed a single protein band in SDS gel electrophoresis. The enzyme is an acidic protein with a pI of 4.5 and has a molecular weight of 54,900 as estimated from SDS gel electrophoresis and 21,500 from gel filtration. The optimum pH and temperature were 5.0 and 35 degrees C, respectively. The enzyme was stable at temperatures up to 45 degrees C and in a pH range between 4.0 and 6.0. The Km was 2.5 mg ml-1 for colloidal chitin, Hg2+ and Ag+ were effective inhibitors. The viscosimetric study carried out using carboxymethyl chitin as substrate revealed the endotype action of this enzyme.

Autolysis↗
PubMed1995

Renal angioscopy.

Explore the source record for details and available documents.

Accidents, Traffic↗
PubMed1995

Demyelinating hereditary neuropathies in children: a morphometric and ultrastructural study.

Twenty-three cases of hereditary demyelinating neuropathies are reported, 13 with different types of hereditary motor and sensory neuropathy (HMSN) and 9 with globoid cell or meta-chromatic leucodystrophies. Ultrastructural and morpho-metric studies showed some critical pathological features emphasizing: 1) the variability of the recessive forms of HMSN; 2) the morphological distinction between HMSN type I and type III; and 3) differences between these types of HMSN and other "onion bulb" neuropathies such as those found in leucodystrophies, which account for distinct underlying mechanisms.

Adolescent↗
PubMed1995

[Cervical cystic hygroma].

We present a clinical case of prenatal ultrasound diagnosis of cystic hygroma resulting in intrauterine fetal death. In the follow up we review the clinical pathology of the case.

Adult↗
PubMed1994

Synthesis and atypical antipsychotic profile of some 2-(2-piperidinoethyl)benzocycloalkanones as analogues of butyrophenone.

Four new 2-(2-piperidinoethyl)benzocycloalkanone derivatives, 20-23, were prepared and evaluated as potential antipsychotic agents in receptor binding assays for dopamine (DA) and 5-HT2A receptors and in functional and behavioral screens. Their affinities for D2 receptors (Ki's in the nanomolar range: 46.7-70.7) and D1 receptors (Ki's in the micromolar range: 1.09-2.81) were slightly lower than that showed by haloperidol (Ki's in the nanomolar range: 5.01 and 97.72 for D2 and for D1 receptors, respectively). The ratio of pKi's values D1/D2 showed that the new molecules are more D2-selective than haloperidol. In contrast, in the [3H]-ketanserin binding assays the new compounds had greater affinity for 5-HT2A receptors (pKi's 7.89-8.60) than haloperidol (pKi 7.70) and in functional studies, endothelium-stripped aorta rings, the pA2 values (6.75-8.12) were slightly lower than that of ketanserin (8.87) in suppressing serotonin-induced contractions. The pKi's for D2 binding (and to a lesser extent pKi's for D1 binding) tend to be greater among typical (classical) than among atypical antipsychotics, while these two classes of antipsychotics exhibit no difference with regard to pKi's for 5-HT2A receptors. The ratios of pKi's for 5-HT2A/D2 receptors may be useful for rapid screening of new compounds, and its potential induction of extrapyramidal symptoms (ratio values > 1.12 were predictive of an atypical antipsychotic profile). The new molecules had a ratio value in the range 1.08-1.20, while haloperidol showed a ratio of 0.93. In the behavioral screening tests, the new molecules showed antagonist activity of amphetamine-inducing hyperactivity and apomorphine-induced climbing (predictive tests for antipsychotic activity). In the catalepsy test (predictive test for induction of extrapyramidal symptoms), the values obtained were in accordance with an atypical antipsychotic drugs profile.

Amphetamine↗
PubMed1994

[Attitude of primary care personnel towards HIV infection. Results of a survey].

OBJECTIVE: To evaluate the understanding, previous experience and attitudes of Primary Care (PC) staff regarding the Human Immunodeficiency virus (HIV) and to identify the preferred care environment for these patients. DESIGN: An observation study of a crossover type done by filling in a questionnaire. SETTING: Nine Primary Care centres in the province of Valladolid. PATIENTS: Random sample of the staff of the PC teams at the above-mentioned centres. RESULTS: Questionnaires returned by 174 health-workers, averaging 34.5 years old, were studied. 61.49% evaluated their own knowledge as acceptable, though all those surveyed wished to broaden their information concerning HIV infection. 71.83% had cared for under 5 patients in the previous ten years. 20.69% would refuse to look after these patients. There was a significant link between professionals' attitudes and the variables of age and their particular professional activity. 80.23% chose a single location as their preferred option for care, the majority in special centres. CONCLUSIONS: The knowledge that Primary Care health staff have about HIV infection does not seem to come from their experience in handling these patients. To achieve a greater commitment of the PC professional to caring for these patients, it would be necessary to offer specific clinical, epidemiological and preventive training and provide the requisite funds and resources. These kinds of study are a contribution to the widening of the documentation on the level of knowledge and attitudes towards HIV infection and their handling by professionals working in PC teams.

Adult↗
PubMed1994

Biotyping of Campylobacter jejuni and Campylobacter coli infections in Spain.

Biochemical profiles were studied in 102 Campylobacter isolates from patients affected by enteric disease in Orense (Spain) over a 1-year period. The isolates were identified as hippurate-positive Campylobacter jejuni (n = 90), Campylobacter coli (n = 10) and hippurate-negative C. jejuni (n = 2). Seventy-seven of the hippurate-positive and both hippurate-negative C. jejuni isolates were biotyped as C. jejuni subsp. jejuni biotype 1, nine as C. jejuni subsp. jejuni biotype 2 and four as C. jejuni subsp. doylei. Hippurate-hydrolysis was correlated to a simple scheme based on L-arginine arylamidase production, propionate assimilation and malate assimilation which yielded sensitivity and specificity values of 0.90 and 1.00, respectively. Effective grouping of nalidixic acid-resistant C. jejuni and C. coli isolates (38.5% of the total) was also achieved.

Bacterial Typing Techniques↗
PubMed1994

Paper mill effluent decolorization by fifty streptomyces strains.

Fifty actinomycete strains isolated from lignocellulosic substrates were examined for the ability to remove the color from a paper mill effluent obtained after semichemical alkaline pulping of wheat straw. Streptomyces sp. strains UAH 15, UAH 23, UAH 30, and UAH 51 were selected for their ability to decolorize the effluent in a liquid medium containing 1% (wt/vol) glycerol, 0.2% (wt/vol) ammonium sulfate, and 80% (vol/vol) effluent. The highest levels of decolorization achieved after the strains grew were 60 to 65%. Strains UAH 30 and UAH 51 were selected for further study because of their different patterns of effluent decolorization during growth. Fractionation of the decolorized effluent by gel permeation chromatography demonstrated that there were reductions in the levels of absorbance of the high- and medium-molecular-weight compounds. These fractions were mainly responsible for the color of the effluent, while the last fractions, the low-molecular-weight compounds, could have been responsible for the residual color of the decolorized effluent. Thin-layer chromatography revealed significant differences among the patterns of bands corresponding to the acidified supernatants obtained after precipitation of alkali-lignin from the effluent samples decolorized by different Streptomyces strains.

Journal Article↗
PubMed1994

[The "arrhythmic pattern": a new method with prognostic significance in myocardial infarct].

OBJECTIVES: To establish a score or arrhythmic pattern for the prediction of long-term cardiac deaths on patients who have survived to the first acute myocardial infarction. PATIENTS AND METHODS: We studied prospectively 200 patients that survived at a first myocardial infarction and in whom ambulatory ECG monitoring during 24 hours between days 7th and 18th (mean 12th) from the infarction was performed. The mean follow-up time was 51 +/- 18 months. The number and type of ventricular arrhythmias were analyzed and a score was measured, accordingly with Castellanos and Lown's classifications. An "arrhythmic pattern" or "total punctuation" was defined and compared among two groups: group 1 > 65 points and group 2 < 65 points. RESULTS: The differential characteristics of both groups were: age (60 +/- 9 versus 56 +/- 10 years old; p = 0.004); hypertension (63% versus 29%; p < 0.001); clinic stage II-III (23% versus 11%; p = 0.02); echocardiographic ejection fraction (45 +/- 11% versus 50 +/- 10%; p = 0.04); positive exercise testing (73% versus 56%; p = 0.01); arrhythmias on the exercise test (15% versus 25%; p = 0.006). The long-term cardiac mortality was 25% versus 6% (p = 0.01), with an incidence of sudden death of 11% versus 3% (p < 0.05). Specificity, sensibility, positive predictive value and negative predictive value (reference cut point of 100) were 94, 65, 71 and 91%, respectively. CONCLUSIONS: The use of a score of arrhythmic pattern may identify 2 groups of patients with different clinic profiles that probably justify a different long-term prognosis after a first acute myocardial infarction.

Cardiac Complexes, Premature↗
PubMed1994

[Efficacy of Chagas' disease vector control demonstrated through human infection].

The aim of this study was to assess the efficacy of Chagas disease vector control in Chile, using human disease as an index. After a twelve years control program using insecticides, dwelling infection in the IV region fell from 49 to 4%. In Combarbalá (a community of the IV region) the infection rate, detected by indirect hemagglutination, immunofluorescence and ELISA tests, decreased from 21.8% in 1986 to 8.2% in 1992 in primary school students (p < 0.001) and from 7.5 to 5% in high school students. Besides the vector control program, no other important epidemiological changes occurred in this period, excepting some ecological changes.

Adolescent↗
PubMed1994

[Treatment of chronic human Chagas disease with itraconazole and allopurinol. Preliminary report].

The aim of this work was to assess the efficacy of itraconazole and allopurinol in chronic Chagas disease. Two hundred two subjects (137 infected, 59 with Chagas cardiopathy and 6 with non chagasic cardiopathy) were randomly assigned to be treated with itraconazole (87 subjects receiving 6 mg/kg/day for 120 days), allopurinol (68 subjects receiving 8.5 mg/kg/day for 60 days) or placebo (47 subjects during 60 days). Medications were well tolerated. Indirect hemagglutination test was modified in 5 subjects (3.2%) after treatment. Initially positive xenodiagnosis became negative in 34 of 36 subjects (94.4%) treated with itraconazole and 8 of 10 subjects (80%) treated with allopurinol. Initially normal EKG was not modified in 100% of patients receiving placebo, 84.9% receiving itraconazole and 86.7% receiving allopurinol. Initially abnormal EKG became normal in 10 of 31 subjects (32%) receiving itraconazole, 8 of 20 (40%) receiving allopurinol and none of 8 receiving placebo. It is concluded that xenodiagnosis and EKG improvements indicate that itraconazole and allopurinol have a role in the treatment of chronic Chagas disease. A 36 months follow up of these patients will help to confirm this conclusion.

Adolescent↗