Donor-specific flow cytometric cross-match after kidney transplantation.
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B-Lymphocytes↗
Biomedical subjects
R Rodriguez
Publications and source records attributed to R Rodriguez.
Preparation of pig pure islets without using density gradients.
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Animals↗
Differential diagnosis and evaluation of the incidentally discovered renal mass.
Recent advances in technology, coupled with decreasing costs, have led to a substantial rise in the diagnosis of the incidentally discovered renal mass. In virtually all of these cases, the underlying signs and symptoms of an occult renal tumor were either absent or sufficiently minor as to escape the notice of the referring physician. Although the majority of the renal masses are benign renal cysts, many are indeterminate or frankly malignant. The evaluation of these tumors is typically completed with contrast-enhanced static or spiral computed tomography; however, ultrasound may be sufficient in many cases to definitively diagnose renal cysts. The size and location of these tumors often dictates treatment, and recently, less conservative management has found to be reasonably safe and effective. For instance, small localized tumors are now being considered for tumor enucleation, heminephrectomy or partial nephrectomy, even in the presence of an otherwise normal contralateral kidney. Recent innovations, including intraoperative sonography, have given the urologic surgeon an additional tool for complete evaluation of the indeterminate renal mass. These issues are discussed in detail, in order to achieve a rational approach to the differential diagnosis and evaluation of the incidental renal mass.
Biopsy, Needle↗
Brain potentials and the availability of semantic and phonological codes over time.
ERPs were recorded from subjects performing semantic and rhyme matching tasks using either spoken words, printed words or pictures as stimuli. Mismatches enhanced N400 (in the semantic task) and N450 (in the rhyme task). Onset and peak latencies were shorter for N450 than for N400 with spoken words; this relationship was inverted for pictures. Thus these latencies could index availability of semantic and phonological codes. For printed words, the latencies were shorter for N400 than N450, a result that supports direct-access modes of reading with late phonological code activation. The longer latencies found for N400 and N450 to pictures could suggest longer initial decoding for pictures with respect to words.
Adolescent↗
Food mustard allergen interaction with phospholipid vesicles.
Sin a I, the major allergen from mustard seeds, interacts with acid phospholipid vesicles. The protein binds to dimyristoylglycerophosphoglycerol vesicles with an apparent dissociation constant of approximately 2.4 microM, the number of phospholipid molecules affected by one protein molecule being approximately 20. Sin a I promotes an increase in the light scattering of a vesicle suspension. This process becomes saturated at approximately a lipid/protein molar ratio of 20:1. Sin a I also modifies the thermotropic behaviour of the negatively charged vesicles, which has been studied by measuring the fluorescence polarization of the probe 1,6-diphenyl-1,3,5-hexatriene incorporated into the hydrophobic core of the bilayer. Sin a I also promotes lipid mixing between vesicles. This mixing has been analyzed by measuring the variation of the fluorescence energy transfer between N-(7-nitro-2-1,3-benzoxadiazol-4-yl)-dimyristoylglycerophosphoe thanolamine (donor) and N-(lissamine rhodamine B sulphonyl)-PtdEtn (acceptor) incorporated into dimyristoylglycerophosphoglycerol vesicles. This effect is also corroborated by observing a single thermotropic transition in a mixture of independent dipalmitoylglycerophosphoglycerol and dimyristoylglycerophosphoglycerol vesicles when Sin a I is added to the lipid suspension. The allergen promotes release of aqueous contents of PtdGro vesicles, as determined by an aminonaphthalenetrisulfonic acid/p-xylylenebis(pyridinium)bromide dequenching assay. This study shows that the allergen Sin a I is able to interact with membrane lipids. This interaction is discussed in terms of its potential involvement in the allergenicity of this protein.
Allergens↗
Kinetics of cell labeling and thymidine replacement after continuous infusion of halogenated pyrimidines in vivo.
PURPOSE: Iododeoxyuridine (IdUrd) is a halogenated pyrimidine which has been recognized as a clinical radiosensitizer. It is generally agreed that the extent of radiosensitization correlates with the degree of thymidine substitution in DNA. Controversy exists regarding the optimal administration schedule to achieve maximum radiosensitization. To obtain more information relating to this problem, we present experiments on an in vivo human tumor xenograft continuously exposed to a fixed serum concentration of halogenated pyrimidines so as to study the kinetics of cell labeling and thymidine replacement. METHODS AND MATERIALS: Human colon tumor (HCT-116) cells were injected subcutaneously into nude mice. After 10 days, most animals (> 90%) developed measurable tumor nodules with a volume doubling time of 5 +/- 1 days. Once the tumors reached a cross-sectional area of 0.25-0.30 cm2, miniosmotic pumps were implanted to deliver a dose of 100 mg/kg/day of IdUrd by continuous infusion. After an IdUrd exposure time of 1-7 days, blood and tumor tissue were collected. RESULTS: The steady state serum IdUrd concentration was 0.95 +/- 0.1 microM, which is a clinically relevant concentration for a prolonged continuous intravenous infusion. The tumor cell potential doubling time (Tpot) was 25 +/- 2 h. The percent IdUrd thymidine replacement and the fraction of cells labeled, followed exponential saturation kinetics with a halflife of 33 +/- 9 and 27 +/- 2 h, respectively. After 5 days of exposure (congruent to 5 x Tpot), the thymidine replacement in tumor cells was 2.0 +/- 0.2% and the fraction of tumor cells labeled was 94 +/- 1%. Immunohistochemical staining of IdUrd labeled tumor tissues showed an exposure dependent gradient of cellular labeling that was initially highest in regions close to blood vessels. After 4 days of exposure at 100 mg/kg/day, there was an increase in the fraction of cells in G(0) + G1 and a decrease in the S phase population, suggesting a block between G1 and S phase. CONCLUSION: We conclude that the in vivo kinetics of IdUrd thymidine replacement and fraction of cells labeled after continuous exposure followed exponential saturation kinetics with a halflife of approximately the potential doubling time of the tumor cell population. Simple modeling suggests that some form of prolonged, or briefly interrupted, continuous infusion should be considered for clinical administration because such schedules would leave fewer cells unsensitized than shorter infusions would. Even 10% of unlabeled clonogenic cells could explain the lack of dramatic clinical successes with IdUrd or BrdUrd sensitization.
Animals↗
Differential sensitivity to inhibitors discriminates between two types of kinases responsible for in vivo phosphorylation of different sites in the carboxy-terminal tail of chicken neurofilament-M.
In order to characterize the phosphorylation of neurofilaments (NF) in intact neurons, we examined the ability of several protein kinase inhibitors to interfere with the incorporation 32P into individual NF polypeptides of sensory neurons in culture. We also examined their effect on the post-translational mobility shift on SDS-PAGE that accompanies phosphorylation of newly synthesized NF-M. Several agents known to inhibit cyclic nucleotide-, Ca2+/calmodulin-, and Ca2+/phospholipid-dependent protein kinases (H7, HA1004, trifluoperizine, sphingosine) had no effect on the phosphorylation of any NF polypeptide, in either assay. In contrast, two broadly active protein kinase inhibitors, staurosporine and K252a, inhibited the incorporation of 32P into NF-M by 60-70% and also blocked the post-translational mobility shift. They had no effect on NF-L. The action of staurosporine and K252a was identical to that of 25 mM LiCl. Proteolytic cleavage and phosphopeptide mapping of 32P-labeled NF-M from control and treated cultures revealed that the phosphorylation of only one subset of phosphopeptides was affected by staurosporine, K252a, and LiCl. These were contained within a single chymotryptic fragment of the NF-M tail segment, probably containing most of the 17 repeats of a KXXS/TP motif. The phosphorylation of another subset of phosphopeptides was insensitive to these inhibitors. They were contained within a different chymotryptic fragment of the tail segment which contains a KSD and four KSP potential phosphorylation sites. This differential sensitivity to protein kinase inhibitors distinguishes two different types of effector-independent kinases that phosphorylate, in vivo, different sites within the NF-M tail.
1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
Diuretic action of an aqueous extract of Lepidium latifolium L.
An aqueous extract of Lepidium latifolium L. given orally and intraperitoneally considerably enhanced urinary excretion (UV) in rats with respect to control groups. A slight increase in ion excretion was also observed. Other parameters such as specific gravity, nitrite, pH, glucose, ketone bodies, urobilinogen, and blood were also studied. A good correlation for the dosage rat/man for the aqueous extract was achieved.
Administration, Oral↗
Minoxidil (Mx) as a prophylaxis of doxorubicin--induced alopecia.
BACKGROUND: Minoxidil (Mx) is known to induce hair growth in men with male-pattern baldness. Based on this potential, the effectiveness of Mx 2% topical solution was evaluated in cancer patients (pts) to prevent doxorubicin-induced alopecia. PATIENTS AND METHODS: 48 female pts with different types of solid tumors treated with doxorubicin-based chemotherapy in a dose range of 50-60 mg/m2/cycle were randomly assigned to receive Mx 2% topical solution or placebo. RESULTS: 88% and 92% of pts in both arms showed severe alopecia (p = ns). No adverse effects were observed. CONCLUSION: In this study Mx 2% topical solution was non-toxic but was not effective in the prevention of chemotherapy-induced alopecia.
Adult↗
Measurements of fentanyl and sufentanil in blood and urine after surgical application. Implication in detection of abuse.
An increase in cases of death from overdose and abuse from fentanyl or sufentanil is being encountered by the Bexar County Forensic Science Center in San Antonio, Texas. These drugs have been abused almost solely by health care professionals. The fentanyl derivatives cannot currently be detected by routine laboratory drug-screening programs. Forensic toxicology assays that identify the specific analyte must be used. We report a sensitive assay for detection of fentanyl and sufentanil with a detection limit of -0.5 ng/ml. In addition, results from the analysis of urine and blood samples obtained up to 72 h after drug administration to five patients undergoing cardiac bypass surgery who had received either fentanyl or sufentanil are described. The new procedure enables detection of these drugs more readily, in smaller amounts, and for a longer period of time after use than previously possible. We hope this will lead to intervention and treatment in those abusing the drugs.
Aged↗
Therapeutic efficacy of camptothecin derivatives against human malignant melanoma xenografts.
Camptothecin (CPT) and some of its derivatives are currently used in several clinical studies with patients bearing leukaemias, lymphomas, and malignancies of various solid tissues. Therefore, it is important to establish parameters and conditions that will allow the drugs to exhibit maximal anti-cancer effectiveness with minimal toxic effects. We tested several water-insoluble CPT derivatives for their ability to inhibit growth of human melanoma tumours xenografted in nude mice. We found that anti-tumour effectiveness and drug-induced toxicity depended on (a) the CPT derivative; (b) the drug dose administered; (c) the mode of administration; and (d) the scheduling of drug administration. For all practical purposes, oral administration of the CPT derivative, 9-nitrocamptothecin, has produced the best overall results.
Animals↗
Evidence that use of a second-generation hepatitis C antibody assay prevents additional cases of transfusion-transmitted hepatitis.
The aim of this study was to determine if using hepatitis C antibody (anti-HCV) enzyme immunoassay version 2.0 (EIA2) in addition to version 1.0 (EIA1) increased the safety of the blood supply. Blood non-reactive by anti-HCV EIA1 was transfused in 1990-92. Stored samples from 40098 units, donated prior to 13 March 1992 were later tested by EIA2. For donor units reactive for anti-HCV by EIA2, a recombinant immunoblot assay (RIBA2) was also carried out. In 63 cases, recipients of transfusions which were EIA2 negative or EIA2 reactive were tested for anti-HCV and elevated alanine aminotransferase (ALT) levels 9-12 months after transfusion; pretransfusion anti-HCV status of recipients was unknown. Among these multitransfused patients receiving units that were negative by both EIA1 and EIA2, 1/26 (4%) had anti-HCV. Among transfusion recipients of units negative by EIA1, but who received at least one unit reactive by EIA2, 4/37 recipients (11%) were anti-HCV reactive (P = 0.59). For the recipients of EIA2 reactive blood, when the donor unit was RIBA2 non-reactive, 0/23 recipients were reactive by anti-HCV. Among the recipients of a RIBA2 indeterminate unit, 1/10 recipients had anti-HCV, but for patients who received at least one RIBA2 reactive unit, 3/4 recipients had anti-HCV (P = 0.03). Hence, second-generation anti-HCV testing detected additional units capable of transmitting hepatitis C that were not detected by first-generation testing. However, RIBA2 is a more specific method than EIA2 for determining units capable of transmitting HCV.
Aged↗
Modulatory influence of putative inhibitors of nitric oxide synthesis on visual processing in the cat lateral geniculate nucleus.
1. Using an in vivo preparation we have examined the actions of two inhibitors of nitric oxide synthase (NOS), NG-nitro-L-arginine (L-NOArg) and NG-methyl-L-arginine (L-MeArg), in the feline dorsal lateral geniculate nucleus (dLGN). We compared the responses obtained to iontophoretic application of these substances during visual stimulation with those elicited by visual stimulation alone. The effects of concurrent ejection of L-arginine (L-Arg), the normal physiological substrate of NOS, and D-arginine, the inactive isomer, were tested on these responses. 2. Extracellular application of L-NOArg and L-MeArg produced clear and repeatable effects, consisting of substantial reduction in discharge rate without affecting response selectivity, on 94% of tested cells. These effects were prevented by simultaneous application of L-Arg, which when ejected alone produced no change on visual evoked responses. 3. The data suggest that nitric oxide (NO) is necessary for the transmission of the visual input under normal visual stimulation and show a direct involvement of NO in visual information processing at the level of dLGN, suggesting that its contribution to brain mechanisms is more profound than previously thought.
Amino Acid Oxidoreductases↗
Ole e I: epitope mapping, cross-reactivity with other Oleaceae pollens and ultrastructural localization.
Ole e I is the major allergen derived from olive tree pollen (Olea europaea) and it is composed of two polypeptides with molecular weights (MWs) of 18 and 20 kD. A panel of six monoclonal antibodies (mAbs) has been prepared and used to map antigenic determinants on this molecule. Four epitope determinants have been identified on Ole e I. Using the purified mAbs produced against Ole e I, we have analyzed the common epitope determinants in olive (O. europaea) and different Oleaceae pollens: ash (Fraxinus excelsior); privet (Ligustrum vulgare); lilac (Syringa vulgaris), and forsythia (Forsythia suspensa). ELISA showed three reactivity groups depending on the recognition of monoclonal antibodies: (1) olive and ash; (2) olive, ash, privet and lilac; and (3) olive, ash, privet, lilac and forsythia. Immunoblotting studies on Oleaceae pollen extracts with these mAbs showed a very similar cross-reactivity pattern. The 18- and 20-kD MW proteins were present in each pollen, except in the case of forsythia. In this case the reactivity pattern was associated with 50- to 55-kD protein bands. This band was recognized by a pool of sera from olive-allergic patients. Finally, ultrastructural localization of Ole e I antigen was performed on the mature olive pollen grain. Ole e I was located in association with dilated endoplasmic reticulum cisternae. Pollen grain walls, nuclei and cytoplasmic organelles were totally devoid of the allergen.
Allergens↗
Vinorelbine as first-line chemotherapy for metastatic breast carcinoma.
PURPOSE: A phase II trial was performed to evaluate the efficacy and toxicity of vinorelbine (VNB) as first-line chemotherapy for metastatic breast carcinoma. PATIENTS AND METHODS: Between August 1991 and February 1993, 45 patients with metastatic breast cancer were entered onto the study. Therapy consisted of VNB 30 mg/m2 diluted in 500 mL of normal saline administered as a 1-hour intravenous infusion. Injections were repeated weekly until evidence of progressive disease (PD) or severe toxicity developed. RESULTS: One patient was considered not assessable for response. An objective response (OR) was observed in 18 of 44 patients (41%; 95% confidence interval, 26% to 56%). Three patients (7%) had a complete response (CR) and 15 (34%) had a partial response (PR). The median time to treatment failure for the entire group was 6 months (range, 1 to 15), and the median duration of response was 9 months (range, 1 to 15). The median survival duration has not been reached yet. There were no treatment-related deaths. The dose-limiting toxicity was myelosuppression. Leukopenia occurred in 35 patients (78%) and was grade 3 or 4 in 16 (36%). Phlebitis was observed in 19 of 29 patients (66%) who did not have central implantable venous systems. Fifteen patients (33%) developed peripheral neurotoxicity. Myalgia occurred in 20 patients (44%). CONCLUSION: VNB is an active drug against metastatic breast cancer with moderate toxicity, which justifies further evaluation in association with other agents.
Adult↗
Paromomycin resistance in Leishmania tropica: lack of correlation with mutation in the small subunit ribosomal RNA gene.
The aminoglycoside antibiotic paromomycin is a potentially useful anti-leishmanial chemotherapeutic agent. Resistance to this antibiotic was studied using Leishmania tropica. Promastigotes resistant to 210 micrograms/ml of paromomycin were selected by exposing them to gradual increments of this drug. Previous work in Escherichia coli, Tetrahymena, and yeast mitochondrial mutants has demonstrated mutations in the E. coli small subunit ribosomal RNA at the 1409:1491 basepair position, or equivalent positions in other organisms, resulting in basepair disruption. When the nucleotide sequence at both the DNA and RNA levels of the resistant L. tropica promastigotes cultured in the presence of paromomycin was compared with those of the drug-sensitive parent, there was no sequence change at the putative mutation site. Paromomycin resistance in L. tropica is apparently due to other mechanisms.
Animals↗
Physiological studies on gentamicin: phosphate repression of antibiotic formation.
The effect of inorganic phosphate on the fermentative production of gentamicin by Micromonospora purpurea has been studied using a chemically defined medium. Phosphate concentrations higher than 5.75 mM (1 g/liter-1) did not inhibit growth but specifically prevented antibiotic formation. Changes in the pH medium and carbon or nitrogen depletion were excluded as the cause of antibiotic underproduction. The use of a phosphate analogue, a protein synthesis inhibitor and the profiles of differential rate of antibiotic production suggested that phosphate itself transiently repressed gentamicin formation. Phosphate affected the formation of 2-deoxystreptamine from 2-deoxyinosose, a none phosphorylated substrate.
Arsenates↗
Hypocholesterolemia, hypertriglyceridemia, suicide, and suicide ideation in children hospitalized for psychiatric diseases.
To assess relationships of total plasma cholesterol (TC) and triglyceride (TG) values to suicide, suicide ideation, and hospitalization for psychiatric disease, we studied 220 children, ages 5 to 18 y, hospitalized with affective, adjustment, disruptive, anxiety, schizophrenic, other, and organic psychiatric disorders. The 135 male and 85 female patients had higher TG values (p = 0.0001 and 0.0003, respectively) and higher Quetelet Indices (p = 0.0001 and 0.003, respectively) than the 732 male and 316 female schoolchild controls; male patients had higher TC values than male controls (p = 0.014). Substance abuse in patients was an independent inverse determinant of TC value (p = 0.05); TG value correlated positively with alcohol use (p < or = 0.1) and substance abuse (p < 0.05). After covariance adjustment for age, race, sex, and Quetelet, children having adjustment disorders with depression had much lower covariance-adjusted TC value than control schoolchildren (3.91 versus 4.29 mmol/L, p = 0.003), whereas those with disruptive behavior with oppositional defiant disorder had much higher adjusted TC value (5.09 mmol/L, p = 0.0001). After covariance adjusting for age, race, sex, Quetelet, cigarette smoking, alcohol use, and substance abuse, children having adjustment disorders with concomitant depression had the highest group suicide tendencies (attempts and ideation) and the lowest covariance-adjusted TC value (4.03 mmol/L). Conversely, children having disruptive behavior with attention deficit hyperactivity disorder or disruptive behavior with oppoistional defiant disorder had 50% lower suicide index than those with adjustment disorders with concomitant depression and higher adjusted TC levels (4.45 and 5.12 mmol/L, p = 0.0003).(ABSTRACT TRUNCATED AT 250 WORDS)
Adjustment Disorders↗