PubMed Health⌕ Search

Biomedical subjects

J A Gonzalez

Publications and source records attributed to J A Gonzalez.

34 records · Page 2Linked to original sources
PubMed1992

Complications of intravesical bacillus Calmette-Guerin: a case report.

Bacillus Calmette-Guerin (BCG) is the most effective agent currently available to treat superficial bladder cancer. However, this form of therapy is not without potential serious or fatal complications. In addition to the potentially toxic systemic side effects attributed to hematogenous absorption of the bacillus, direct upper tract seeding may occur in patients with vesicoureteral reflux. We report on a patient treated with intravesical BCG for bladder cancer in whom unilateral necrotizing granulomatous pyelonephritis developed. Although severe, this complication is rare and we conclude that reflux is not a contraindication for intravesical BCG therapy.

Administration, Intravesical↗
PubMed1991

Subunit structure of the hemocyanins of some of the Muricidae and Fasciolariidae families: Chicoreus florifer dilectus (A. Adams), Muricanthus fulvescens (Sowerby), Urosalpinx cinerea (Say), Fascilaria lilium hunteria (Perry), and Pleuroploca gigantea (Kiener).

1. The hemocyanins of the Muricidae and Fasciolariidae families of marine gastropods: Chicoreus florifer dilectus, Muricanthus fulvescens, Urosalpinx cinerea, Fasciolaria lilium hunteria, and Pleuroploca gigantea were investigated by sedimentation velocity, scanning transmission electron microscopy, light-scattering, and other physical techniques. 2. The hemocyanins of these species are characterized by sedimentation coefficients close to 100 S and molecular weights of 8.2 x 10(6)-9.0 x 10(6). 3. The hemocyanins have di-decameric structures, with tail-to-tail arrangement of the decameric halves of the cylindrical particles. Only the hemocyanin of U. cinerea was found to contain about 30% higher, tri-, and tetra-decameric particles, with one or two decameric units added in a tail-to-head manner to a central di-decameric particle of the Mellema and Klug tail-to-tail arrangement. 4. The influence of pH, and the urea and Hofmeister salt series of reagents on the subunit structure and denaturation of P. gigantea hemocyanin were also investigated.

Animals↗
PubMed1991

Inhibition of macrophage and endothelial cell nitric oxide synthase by diphenyleneiodonium and its analogs.

The cofactor requirements of macrophage nitric oxide (NO.) synthase suggest involvement of an NADPH-dependent flavoprotein. This prompted us to test the effect of the flavoprotein inhibitors diphenyleneiodonium (DPI), di-2-thienyliodonium (DTI), and iodoniumdiphenyl (ID) on the NO. synthases of macrophages and endothelium. DPI, DTI, and ID completely inhibited NO. synthesis by mouse macrophages, their lysates, and partially purified macrophage NO. synthase. Inhibition of NO. synthase by these agents was potent (IC50's 50-150 nM), irreversible, dependent on time and temperature, and independent of enzyme catalysis. The inhibition by DPI was blocked by NADPH, NADP+, or 2'5'-ADP, but not by NADH. Likewise, FAD or FMN, but not riboflavin or adenosine 5-diphosphoribose, protected NO. synthase from inhibition by DPI. Neither NADPH nor FAD reacted with DPI. Once NO. synthase was inhibited by DPI, neither NADPH nor FAD could restore its activity. DPI also inhibited acetylcholine-induced relaxation of norepinephrine-preconstricted rabbit aortic rings (IC50 300 nM). Inhibition of acetylcholine-induced relaxation persisted for at least 2 h after DPI was washed out. In contrast, DPI had no effect on norepinephrine-induced vasoconstriction itself nor on vasorelaxation induced by the NO.-generating agent sodium nitroprusside. These results suggest that NO. synthesis in both macrophages and endothelial cells depends on an NADPH-utilizing flavoprotein. As a new class of NO. synthase inhibitors, DPI and its analogs are likely to prove useful in analyzing the physiologic and pathophysiologic roles of NO(.).

Amino Acid Oxidoreductases↗
PubMed1991

The clinical utility of prostate-specific antigen and bone scintigraphy in prostate cancer follow-up.

To assess the value of serum prostate-specific antigen (PSA) in prostate cancer follow-up, we prospectively studied 107 consecutive patients with: (1) pathologically confirmed prostate cancer; (2) definitive prostatectomy and/or radiation therapy greater than or equal to 3 mo prior to bone scanning; and (3) one bone scan and serum PSA sampling within 3 mo of each other. The mean and range of patient follow-up since definitive therapy was 1.6 and 0.5-8 yr, respectively. Abnormal bone scans were correlated with pertinent radiographs. Of 107 bone scans, 16 demonstrated metastatic bone disease. A PSA value of less than or equal to 8 ng/ml excluded bone metastases with a predictive value of a negative test of 98.5%. Without radiographic correlation, abnormal bone scans rarely represented metastases if the PSA value was less than or equal to 8 ng/ml. In summary, serum PSA concentration determines the need for follow-up bone scanning and assists in scan interpretation in patients status post definitive therapy for prostate cancer.

Adenocarcinoma↗
PubMed1991

Adaptive and bayesian control of digoxin in geriatric patients.

The study was carried out in a total of 22 patients classified in two groups: Group "A" (n = 12) was constituted by geriatric patients with cardiac failure diagnostic and with digoxin treatment previously to start our study. Group "B" (n = 10) was also constituted by geriatric patients, but with arteriosclerosis diagnostic and without prior digoxin treatment. Doses of 0.25 mg of digoxin was administered by oral route in a multiple dosage regimen with dosification at times of 0, 24, 48, 72 and 96 h. Samples of blood were obtained at 0, 0.5, 1.75, 7, 24, 49.75, 72 and 168 h after the first administration. The classics one and two-open kinetic model were considered. The elimination constant (Ke) was estimated in function of creatinine clearance (Clcr) according to the following expression: Ke = Kslope * Clcr. The mean value of kinetic parameters established were: For one-compartment kinetic model: Ka = 15.2 and 15.7 h-1, Vd = 5.4 and 4.5 l/Kg and Kslope 0.0006 and 0.0001 min/ml * h for groups "A" and "B", respectively. For two-compartment kinetic model: Ka = 11.5 and 3.6 h-1, K12 = 0.7 and 0.8 h-1, k21 = 0.2 and 0.2 h-1, Vc = 2.7 and 1.9 l/Kg and Kslope 0.0002 and 0.0002 min/ml * h for groups "A" and "B", respectively.

Adaptation, Physiological↗
PubMed1989

Subunit structure and higher order assembly of the hemocyanins of the Melongenidae family: Melongena corona (Gmelin), Busycon canaliculatum (Linné), B. carica (Gmelin), B. contrarium (Conrad), and B. spiratum (Lamarck).

1. The hemocyanins of the Melongenidae family of marine gastropods: Melongena corona, Busycon canaliculatum, B. carica, B. contrarium, and B. spiratum exist in solution as multi-decameric aggregates characterized by sedimentation coefficients of approximately 105 S, 130 S, 150 S, 170 S, and higher values, corresponding to di-, tri-, tetra-, penta-, and larger multi-decameric particles. 2. The hemocyanins of B. contrarium and B. carica seem to form the largest decameric aggregates with the tri- to penta-decamers respresenting the major constitutents. Scanning transmission electron microscopy (STEM), both of unstained, freeze-dried and negatively-stained specimens, shows the presence of discrete aggregates consisting of up to ten decameric units. 3. The particle masses as determined by STEM mass measurements for individual molecules gave integral multiples of from 4.2 x 10(6) to 4.4 x 10(6) daltons ranging from about 8.2 x 10(6) daltons for the typical di-decamer of B. canaliculatum hemocyanin to as high as about 39 x 10(6) and 43 x 10(6) for the nano-and deca-decamers of B. contrarium hemocyanin. 4. The appearance of the higher multi-decamers in both negatively-stained and freeze-dried specimens suggest that they are formed by the addition of decameric units to a single di-decameric unit "tail-wise" in both directions. The higher aggregates formed seem to terminate with a closed head or collar at both ends of the assembly.

Animals↗
PubMed1988

Nephrogenic adenoma of the bladder: report of 10 cases.

Nephrogenic adenoma is an uncommon metaplastic lesion of the lower urinary tract that usually is associated with antecedent inflammation or surgical procedures. We report 10 new cases, 8 of which followed renal transplantation and 1 of which followed partial cystectomy for squamous cell carcinoma of the bladder. No predisposing factors could be identified in 1 patient. The nephrogenic adenomas, all of which were located in the bladder, were treated by either biopsy with fulguration or transurethral resection. The lesion recurred locally in 1 patient.

Adult↗
PubMed1986

A dynamic vapor exposure system for evaluating passive dosimeters.

A dynamic vapor exposure evaluation system for passive dosimeters has been validated in which benzene is used as the test vapor. The system is capable of generating well defined short-square wave concentration profiles suitable for the evaluation of passive dosimeters for STEL monitoring. These concentration profiles are highly reproducible and accurate to the 0.1-ppm level. The system has been used successfully to evaluate a miniature passive dosimeter for short-term exposure monitoring.

Air Pollutants, Occupational↗
PubMed1976

Serum FSH and synthetic LHRG response in pregnant women at term and in the newborn.

Serum immunoreactive FSH was undetectable in a) pregnant women past 38 weeks of gestation, b) newborn infants, and c) anencephalic infants. The intravenous administration of 100 mug of synthetic LHRH elicited no FSH release in each instance. These results seem to indicate that the absence of FSH in serum in pregnant women in the last trimester, as well as in the newborn, is due to the suppressive effect on the anterior pituitary of the increased amount of circulating sex steroids.

Anencephaly↗
PubMedDate not supplied

Conformal high dose rate iridium-192 boost brachytherapy in locally advanced prostate cancer: superior prostate-specific antigen response compared with external beam treatment.

PURPOSE: Prostate-specific antigen levels are used to judge disease control of prostate cancer. No published data attest to the greater ability of conformal brachytherapy to control disease compared with conventional radiation at a single institution. This report compares the biochemical response rates in patients with stages T2b to T3c prostate cancer treated with conformal brachytherapy boost and external beam radiation with the rates in patients treated with conventional external radiation alone. MATERIALS AND METHODS: From November 1991 through November 1995, 58 patients received 45.6 Gy pelvic external irradiation and three high dose rate iridium-192 conformal boost implants of 5.5 to 6.5 Gy each. They were compared with 278 similarly staged patients treated from January 1987 through December 1991 with external beam radiation to prostate-only fields (median dose 66.6 Gy). No patient received androgen deprivation. Patient outcome was analyzed for biochemical control. Biochemical failure was defined as a prostate-specific antigen level > 1.5 ng/mL and rising on two consecutive values. If serial posttreatment prostate-specific antigen levels were showing a continuous downward trend, failure was not scored. RESULTS: Median follow-up was 43 months for the conventionally treated group and 26 months for the brachytherapy boost group. The median pretreatment prostate-specific antigen level was 14.3 ng/mL for the external-beam-radiation-alone group and 14.0 ng/mL for the brachytherapy boost group. The median Gleason scores were 6 and 7, respectively, for the two groups. The biochemical control rate was significantly higher in the brachytherapy boost treatment group. Three-year actuarial biochemical control rates were 85% versus 52% for the conformally and conventionally treated patients, respectively. In a multivariate analysis, the use of conformal brachytherapy boost and pretreatment prostate-specific antigen level were significant prognostic determinants of biochemical control. The 3-year actuarial rates of biochemical control for conformally versus conventionally treated patients, respectively, were 83% versus 72% for a pretreatment prostate-specific antigen level of 4.1 to 10.0 ng/mL, 85% versus 47% for a prostate-specific antigen level of 10.1 to 20.0 ng/mL, and 89% versus 29% for prostate-specific antigen > 20 ng/mL. When the analysis was limited to patients in both groups with a minimum 12-month follow-up, the brachytherapy boost group continued to show a higher biochemical control rate compared with the conventional radiation group (3-year actuarial rates of 86% vs 53%). DISCUSSION: These preliminary results show a significant improvement in the biochemical response rate with conformal boost brachytherapy and pelvic external radiation compared with conventional radiation alone. These results, coupled with our previously reported acceptable toxicity rates, support the use of this technique.

Aged↗