Small subunit ribosomal RNA gene sequence of the parasitic protozoan Haplosporidium nelsoni provides a molecular probe for the oyster MSX disease.
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Animals↗
Biomedical subjects
R Rodriguez
Publications and source records attributed to R Rodriguez.
Synthesis of beta 2-microglobulin in lymphocyte culture: role of hemodialysis, dialysis membranes, dialysis-amyloidosis, and lymphokines.
Dialysis-amyloidosis (A beta 2M) is a recently recognized chronic complication in long-term dialysis patients, apparently effecting 5% to 10% of all dialysis patients. In 1985, Gejyo et al (Biochem Biophys Res Commun 129:701-706, 1085) and Shirahama et al (Lab Invest 53:705-709, 1985) identified beta 2-microglobulin (beta 2-M) as the major constituent protein of this unique type of systemic amyloidosis. The specific pathogenesis of A beta 2M remains unknown, although beta 2-M has been clearly identified as playing a central role as the amyloidogenic protein. To investigate the factors responsible for in vitro beta 2-M synthesis, we studied beta 2-M production by lymphocyte cultures obtained from dialysis patients and grown under a variety of different conditions, and compared the results to a control group of subjects with normal renal function. We could not demonstrate any stimulatory influence on beta 2-M synthesis by the hemodialysis treatment, the type of dialysis membrane used, or the clinical presence of A beta 2M. Rather, dialysis membranes, sterilized with ethylene oxide or gamma rays, added to the lymphocyte cultures exerted a strong dose-dependent inhibitory effect on beta 2-M synthesis. From the results of this study, we conclude that peripheral blood lymphocytes in uremic patients synthesize beta 2-M normally and that the direct interaction between circulating lymphocytes and the dialysis membrane that occurs during hemodialysis does not seem to contribute directly to beta 2-M synthesis.
Adult↗
Endoscopic and bioptic findings in the upper gastrointestinal tract in patients with Crohn's disease.
A prospective study was carried out on 41 patients diagnosed as having Crohn's disease (CD) to evaluate the degree of upper gastrointestinal tract involvement. In 23 patients (56%), endoscopic alterations were found most frequently affecting the antrum and duodenum. Lesions encountered were: Aphthoid erosions, ulcers, thickening of folds, nodules, erythema and stenosis. Granulomas were found in biopsies in 19.5% of the patients: They were more frequent in those demonstrating endoscopic alterations (26%) than in those with normal endoscopic findings (11%). Clinical evolution was favorable with conventional treatment for CD and ranitidine, although the endoscopic lesions did not totally disappear in any cases. We conclude that upper gastrointestinal endoscopy with biopsies is useful in evaluating the extension of disease and can be of diagnostic value in cases of indeterminate colitis.
Adult↗
Metastatic pattern and DNA ploidy in stage IV breast cancer at initial diagnosis. Relation to response and survival.
Sixty-nine patients with metastatic breast cancer (MBC) at initial diagnosis were analyzed to verify if metastatic pattern and clinical outcome are related to DNA ploidy determined by flow cytometry (FCM). Characteristics of 55 fully evaluable patients were as follows: median age: 61 years; postmenopausal: 75%; bone-only metastases (BM): 60%; extraosseous-only metastases (EM): 40%. Overall response rates (CR + PR) obtained with different chemotherapies and/or hormonal therapies were 58% and 68% for patients with BM and EM, respectively. Sixty percent of specimens resulted aneuploid, and the mean coefficient of variation of the complete series was 5.1%. In the whole group of patients DNA ploidy of primary tumor did not predict the metastatic pattern and had no influence upon response to treatment, duration of response, time to progression, and overall survival. When analyses were carried out according to metastatic pattern, those patients with BM showed similar results. However, within the group with EM, those with diploid tumors presented a significantly better survival (median 18 vs 13 months, p = .04). FCM-DNA analysis seems to identify a subgroup of patients with poor prognosis constituted by those who had aneuploid primary tumors and metastases to extraosseous sites.
Adenocarcinoma↗
Effects of accidental trauma on cytokine and endotoxin production.
OBJECTIVE: To determine the effects of accidental injury of varying severity on interleukin (IL)-1 alpha, IL-6, IL-8, tumor necrosis factor-alpha (TNF-alpha), and endotoxin release. DESIGN: Prospective, multi-unit, longitudinal study. SETTING: Emergency Departments and intensive care units of two university hospitals. PATIENTS: Trauma patients after mild, moderate, and severe injury (Injury Severity Score of < or = 10, 11 to 24, and > or = 25, respectively). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Plasma cytokine and endotoxin concentrations were measured over a 5-day period, starting within 2 hrs of accidental injury. An enzyme-linked immunosorbent assay was used to determine plasma concentrations of IL-1 alpha, IL-6, IL-8, and TNF-alpha. Plasma endotoxin concentrations were measured using a chromogenic limulus amebocyte assay. Preresuscitation samples obtained immediately on arrival in the Emergency Department, and within 2 hrs of injury, demonstrated significant increases of IL-6 and IL-8 concentrations in the severe injury group, in contrast to minimal increases seen after mild or moderate injury. Analysis of serial postresuscitation samples demonstrated rapid increases in IL-6 and IL-8 concentrations within 12 hrs of injury. IL-6 and IL-8 remained increased for 24 hrs after injury, then decreased markedly from their peak values during the next 24 hrs. Increased circulating concentrations of these cytokines continued to be present for > 5 days in the severely injured patients. IL-6 and IL-8 concentrations were only minimally increased in patients 8 and 24 hrs after moderate injury. Endotoxin and IL-1 alpha were not found in any samples, including those samples obtained serially from severely injured patients. No patient at any time point had TNF-alpha concentrations of > 35 pg/mL. CONCLUSIONS: These results demonstrate that severe injury produces rapid, large increases in circulating concentrations of IL-6 and IL-8 that may contribute to the frequent development of the adult respiratory distress syndrome and multiple organ system failure in this clinical setting.
Adult↗
Effects of the novel potassium channel opener, UR-8225, on contractile responses in rat isolated smooth muscle.
1. The effects of UR-8225 [(1,2-dihydro-4-(1,2-dihydro-2-oxo-1-pyridyl)-2,2-dimethyl-1-oxonapht halen-6- carbonitrile)] and levcromakalim were studied on the electrical and contractile responses induced by noradrenaline and KCl and on 86Rb+ efflux in rat aortic rings and on spontaneous mechanical activity in rat portal vein segments. 2. UR-8225 and levcromakalim, 10(-9) M-10(-5) M, relaxed the contractile responses induced by noradrenaline (IC50 = 2.7 +/- 0.4 x 10(-6) M and 6.6 +/- 1.3 x 10(-7) M, respectively) or 30 mM KCl (IC50 = 1.4 +/- 0.2 x 10(-7) M and 9.4 +/- 1.3 x 10(-8) M, respectively) more effectively than those induced by 80 mM KCl. The relaxant effect on noradrenaline-induced contractions was independent of the presence or absence of functional endothelium. 3. The vasorelaxant effect of UR-8225 and levcromakalim can be competitively antagonized by glibenclamide, an ATP-sensitive K+ channel blocker. There were no differences in the calculated pA2 values for glibenclamide to inhibit UR-8225- and levcromakalim-induced relaxations (7.61 +/- 0.08 and 7.69 +/- 0.10, respectively). The slope of the Schild plot yielded values not significantly different from unity (0.95 +/- 0.06 and 0.96 +/- 0.05, respectively). 4. UR-8225 (10(-5) M) hyperpolarized the resting aortic membrane potential from -50.7 +/- 0.7 mV to -66.0 +/- 2.0 mV and stimulated 86Rb+ efflux. 5. UR-8225 and levcromakalim inhibited the contractions induced by Ca2+ in aortae incubated in Ca(2+)-free PSS containing methoxyverapamil in the presence of noradrenaline. 6. Both drugs inhibited the amplitude of spontaneous activity in portal veins (IC50 = 5.1 +/- 1.4 x 10-8 M and 1.5 +/- 0.7 x 10-8 M, respectively), this effect being competitively antagonized by glibenclamide.7. These results indicated that UR-8225 exhibited qualitatively similar, but slightly less potent,vasorelaxant effects than those exerted by levcromakalim, which suggests that they can be related to its ability to activate ATP-sensitive K+ channels in vascular smooth muscle cells.
Animals↗
Ifosfamide and mitoxantrone as first-line chemotherapy for metastatic breast cancer.
PURPOSE: A phase II trial was performed to evaluate the efficacy and toxicity of a combination of ifosfamide (IFX) and mitoxantrone (MXN) as first-line chemotherapy for metastatic breast carcinoma. PATIENTS AND METHODS: Between January 1990 and August 1991, 48 patients with metastatic breast cancer were entered onto the study. Therapy consisted of IFX 2 g/m2 given as a 1-hour intravenous (IV) infusion on days 1 to 3; mesna 400 mg/m2 as an IV bolus immediately before and 4 hours after IFX administration and 2,000 mg orally 8 hours after IFX administration on days 1 to 3; and MXN 12 mg/m2 as an i.v. bolus on day 3. Cycles were repeated every 21 days until progressive disease (PD) or severe toxicity developed. RESULTS: One patient was considered not assessable for response. Objective regression (OR) was observed in 28 of 47 patients (60%; 95% confidence interval, 46% to 74%). Six patients (13%) had a complete response (CR) and 22 (47%) had a partial response (PR). The median time to treatment failure for the whole group was 9 months (range, 1 to 28); median survival was 19 months (range, 2 to 28). There were no treatment-related deaths. The limiting toxicity was myelosuppression. Leukopenia occurred in 37 patients (77%) and was grade 3 or 4 in 19 patients (40%). Nausea and vomiting were observed in 38 patients (80%), mucositis in 16 patients (33%), and grade 2 hematuria in two patients (4%). Eight patients (16%) developed mild neurotoxicity. CONCLUSION: The combination of IFX plus MXN is an active regimen against metastatic breast cancer with moderate toxicity that deserves further evaluation.
Adult↗
Auditory system degeneration in Alzheimer's disease.
We observed a highly topographically specific and consistent pattern of degeneration in the auditory system of Alzheimer's disease (AD) patients. Senile plaques (SP) and neurofibrillary tangles (NFT) were distributed throughout the ventral nucleus of the medial geniculate body (MGB) and the central nucleus of the inferior colliculus (IC) in nine of nine AD patients. Adjacent nuclei within the MGB and IC were consistently spared. NFT and SP were also present in the primary auditory and the auditory association cortices. In all control tissues, there were neither SP nor NFT in any of the above sites. The cochlear nuclei were normal in tissues from both AD and control patients. The ventral nucleus of the MGB is the major thalamic relay station for auditory function and receives fibers from neurons of the central nucleus of the IC, with projections arranged tonotopically in a laminar pattern corresponding to a gradient of high-to-low frequency ranges. The degenerative changes distributed throughout these nuclei suggest that neuronal loss may include all frequency ranges in AD. In contrast, the clinical features of presbycusis in elderly patients include only high-frequency loss due to lesions peripherally in the cochlea or auditory nerves, rather than in the central auditory nuclei. These histologic changes in the brains of AD patients may provide an additional basis for altered cognitive function due to primary sensory deafferentation.
Aged↗
Community health organizing: whom are we empowering?
Current strategies for initiating and operating community health programs rely on one of two approaches. One is a predetermined, operational process. The other comes from the grassroots, beginning with involvement of the recipients of the program. This editorial chronicles how one grassroots program, begun by volunteer mothers and one community health nurse, developed into a partnership for primary health care that advocates and empowers the entire community. In the end, the editorial challenges community health organizers to ask whom their programs are empowering--the community or the organizers themselves?
Community Health Services↗
Small subunit ribosomal RNA gene sequence of the oyster parasite Perkinsus marinus.
The small subunit rRNA gene of the oyster pathogen Perkinsus marinus was characterized from cells of infected oyster hemolymph by polymerase chain reaction and molecular cloning. The gene, 1,793 nucleotides in size, has 77.2% sequence similarity to that of its host, the eastern oyster Crassostrea virginica. The sequence was confirmed using recently available in vitro cultures of P. marinus. DNA from pure P. marinus culture was amplified with specific primers synthesized according to the sequence from infected oyster hemolymph, and predicted size fragments were obtained. Furthermore, restriction digests yielded fragments of expected size in amplified rDNA from in vitro cultures. The P. marinus sequence has 97.5% similarity to the Perkinsus sp. sequence from the Australian mollusc Anadara trapezia.
Animals↗
[Disorders in the immigrant child and family crisis].
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Acculturation↗
Violence in transience: nursing care of battered migrant women.
Nurses working with migrant farm worker women face serious challenges. Poverty, language, and cultural differences between farm worker women and health care providers present substantial barriers to women obtaining access to the health care system. These differences are especially important in instances of domestic violence. The transient life style of migrant farm workers, combined with geographic and social isolation, make it especially difficult for health care providers to meet the needs of migrant battered women. Strategies for working with migrant battered women are offered.
Adult↗
Capillary electrophoresis of hemoglobins and globin chains.
Capillary isoelectric focusing (cIEF) and free zone capillary electrophoresis were evaluated for separation of native hemoglobins and globin chains. High-resolution separations of adult human hemoglobin A, fetal human hemoglobin F, and hemoglobin variants S and C were obtained using cIEF with cathodic mobilization. Absorbance detection in the UV and visible regions were compared, and on-line fast UV or visible-wavelength scanning detection was used to obtain spectral information on separated components. Globin chain analysis was performed on the same hemoglobin species by free zone capillary electrophoresis following precipitation of the protein with acidic acetone. Free zone separations were carried out at low pH in the presence of 7 M urea.
Electrophoresis↗
A method for determination of N-glycosylation sites in glycoproteins by collision-induced dissociation analysis in fast atom bombardment mass spectrometry: identification of the positions of carbohydrate-linked asparagine in recombinant alpha-amylase by treatment with peptide-N-glycosidase F in 18O-labeled water.
Previously, a combined use of fast atom bombardment (FAB) mass spectrometry and peptide N-glycosidase F, an enzyme that cleaves the beta-aspartylglycosylamine linkage of Asn-linked carbohydrates, was successfully applied to identification of N-glycosylation sites in a glycoprotein with the known or DNA-derived sequence (S. A. Carr and G. D. Roberts, 1986, Anal. Biochem. 157, 396-406). Here, we extended the method for easier identification of N-glycosylation sites in a glycoprotein even with unknown sequence. The glycoprotein is digested with peptide-N-glycosidase F in buffer containing 40 at% H2 18O, to yield a deglycosylated protein whose carbohydrate-linked Asn residues are converted to Asp partly labeled with 18O at their beta-carboxyl group during this digestion. The deglycosylated protein is further digested with proteolytic enzymes in an appropriate buffer prepared with normal water, and then peptides are separated on a reversed-phase column by HPLC. Peptides in which carbohydrate-linked Asn has been converted to Asp show a pair of signals ([M + 1]+ and [M + 3]+) in FAB mass spectra due to the partial incorporation of 18O into the beta-carboxyl groups of Asp residues, while the other peptides show normal isotopic ion distributions. Thus, both formally N-glycosylated peptides and, using collision-induced dissociation analysis, N-glycosylation sites can be identified. The application of the present method to the determination of N-glycosylation sites in a recombinant glycoprotein, Bacillus licheniformis alpha-amylase, is described.
Amidohydrolases↗
Effect of depolarizing agents on the Ca(2+)-independent and Ca(2+)-dependent release of [3H]GABA from sheep brain synaptosomes.
The purpose of the present study was to compare the effects of several depolarizing agents on both the membrane potential and on the release of [3H] gamma-aminobutyric acid (GABA) from sheep brain cortex synaptosomes. We examined the effects of KCl, 4-aminopyridine (4-AP), veratridine, ouabain and tetraphenylphosphonium cation (TPP+) on Ca(2+)-independent (carrier-mediated) and Ca(2+)-dependent (exocytotic) release. We found that, in the absence of Ca2+, KCl at 40 mM releases 7.57 +/- 0.65%, veratridine at 50 microM releases 45.85 +/- 2.48%, ouabain at 1 mM releases 8.62 +/- 0.93% and TPP+ at 1 mM releases 4.09 +/- 0.37% of the total accumulated neurotransmitter, provided that the external medium contains Na+. These are about the maximal values of release obtained with each depolarizing agent in a Na+ medium and in the absence of Ca2+. Replacing external Na+ with choline blocks the release observed in the presence of the depolarizing agents in the absence of Ca2+, and this divalent ion can increase [3H]GABA release only for K+ or 4-AP. Synaptosomal depolarization requires Na+ except for K+ depolarization. Furthermore, although Ca2+ stimulates the release of [3H]GABA due to K+ depolarization (13.56 +/- 0.44%) or due to 4-AP (4.26 +/- 0.51%), it inhibits the release due to the other depolarizing agents. The amount of [3H]GABA released by 4-AP in Na+ medium (4.26 +/- 0.51%) is similar to that induced by KCl in the presence of Ca2+ in the absence of Na+ (3.39 +/- 0.29%) which represents only exocytotic release. This suggests that the Ca(2+)-dependent exocytotic release of [3H]GABA can be specifically induced by 4-AP in a Na+ medium, or by KCl in the absence of Na+, as reported by us earlier. The observation that Ca2+ inhibits the Ca(2+)-independent release is of interest because it suggests that Ca2+ may modulate the release of cytoplasmic GABA probably by inhibiting the carrier-mediated release of GABA. It is of interest as to whether Ca2+ regulation depends on intracellular Ca2+.
4-Aminopyridine↗
Effect of various psychotropic drugs on the performance of avoidance and escape behaviors in rats.
The effect of different doses of nine psychotropic drugs upon conditioned avoidance responses (CARs) developed on a stable basis, after appropriate training, was investigated in rats and compared with their capacity to disrupt escape responses (ERs). Haloperidol (HAL), chlorpromazine (CPZ), morphine (MOR), pentobarbital (PENT), chlordiazepoxide (CDP), meprobamate (MPB), and amphetamine (AMPH) dose dependently inhibited both behaviors. Imipramine also disrupted CARs dose dependently, but did not affect ERs at maximal tolerated doses. Significant differences in the minimal effective doses, effective dose range, and time of onset and duration of action, as well as in potency, were observed. The quantitative determination of the level of selectivity, based upon the ratio ED50 escape failure/ED50 avoidance failure, indicated that all CNS depressants tested caused a selective inhibition of avoidance behavior. HAL was found to be the most specific, followed, in order, by CDP, MOR, CPZ, MPB, and PENT, whose ratio values were not significantly different. AMPH produced a nearly parallel impairment of both behaviors and quipazine only affected CARs at toxic doses. It is concluded that both neuroleptic and nonneuroleptic CNS depressant drugs have selective inhibitory effects on avoidance behavior. Data revealed differences that were more quantitative than qualitative.
Animals↗
Are mitotic index and lymphocyte proliferation kinetics reproducible endpoints in genetic toxicology testing?
Lymphocyte proliferation kinetics is an endpoint used in genetic toxicology which has recently been proposed as an alternative for the screening of new cytostatic drugs. Although great variability for this parameter has been reported, there are few reports about the intra- and inter-individual variation of the effects of chemicals on this endpoint. For this reason, experiments were conducted to evaluate the reproducibility of the effects of a well-known cytostatic, mitomycin C (MMC), on the proliferation of PHA-stimulated human lymphocytes, both over time and among samples from several donors. Although inter-individual variability was shown in both parameters in untreated and treated cultures, this variation was not significant. Intra-individual variation was significantly detected only in cultures treated with 0.1 microM MMC.
Adult↗
Optimism, coping, psychological distress, and high-risk sexual behavior among men at risk for acquired immunodeficiency syndrome (AIDS).
In a cohort of gay men responding to the threat of acquired immunodeficiency syndrome (AIDS), dispositional optimism was associated with less distress, less avoidant coping, positive attitudes as a coping strategy, and fewer AIDS-related concerns. Men who knew they were seropositive for human immunodeficiency virus (HIV) were significantly more optimistic about not developing AIDS than men who knew they were seronegative for HIV. This AIDS-specific optimism was related to higher perceived control over AIDS and to active coping among seropositive men only and to health behaviors in both serostatus groups. There was no relation of optimism to risk-related sexual behavior. It is concluded that optimism is psychologically adaptive without necessarily compromising health behavior. It is also concluded that it is useful to distinguish between event-based optimistic expectations and dispositional optimism.
AIDS Serodiagnosis↗