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Biomedical subjects

J Rodriguez

Publications and source records attributed to J Rodriguez.

At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

Effect of zinc on the proliferative response of human lymphocytes: mechanism of its mitogenic action.

To study the effect of Zn on the proliferative response of normal human lymphocytes, ZnCl2 at a final concentration of 10(-4) M was added to cultures of peripheral blood mononuclear cells (PBMC) stimulated with concanavalin A (Con A) and to autologous mixed lymphocyte cultures of responder T lymphocytes and irradiated autologous non-T cells. Addition of Zn increased by about 50% the synthesis of DNA in cultures stimulated with either 10 or 20 micrograms/ml of Con A and markedly enhanced the autologous mixed lymphocyte reaction, which increased about 5-fold in the presence of Zn. In a narrow dose range, Zn induced per se the incorporation of [3H]thymidine by PBMC, with maximal effects in cultures stimulated with 10(-4) M ZnCl2. The percentage of cells expressing receptors for IL-2 and transferrin as assessed by immunofluorescence with the monoclonal antibodies (mAb) anti-Tac and OKT9, respectively, significantly increased when PBMC were stimulated with 10(-4) M ZnCl2 alone. Maximal [3H]thymidine incorporation and maximal percentage of cells bearing those activation markers were observed on day 6 of culture. Thus, the increase in the uptake of [3H]thymidine induced by Zn is not artifactual but due to progression in the cell cycle. Incubation with the mAb anti-Tac significantly inhibited the proliferative response to Zn, indicating that this requires binding of IL-2 to its receptor. However, addition of human recombinant IL-2 did not increase [3H]thymidine incorporation by PBMC cultured in the presence of ZnCl2.

Antibodies, Monoclonal↗
PubMedDate not supplied

Reproductive toxicity of Aroclor-1254: effects on oocyte, spermatozoa, in vitro fertilization, and embryo development in the mouse.

Polychlorinated biphenyls (PCBs) have been reported to adversely affect reproduction in laboratory and wild animals. The present study was undertaken to determine the toxic potential of Aroclor-1254 (A-1254) on in vitro fertilizing ability of oocytes and epididymal sperm and on preimplantation embryo development in the mouse. A-1254 was added to the IVF medium at concentrations of 0.01, 0.1, 1.0, and 10.0 micrograms/mL. Cumulus masses containing the oocytes were obtained from superovulated B6D2F1 mice and were placed in the culture medium containing A-1254 to which epididymal sperm, capacitated in a medium without A-1254, were added. The IVF rate was assessed 20 to 24 h after insemination. A-1254 significantly reduced the mean percent ova fertilized even at 0.1 microgram/mL. Incubation of the cumulus masses in various concentrations of A-1254 for 6 h, followed by insemination with sperm capacitated in the presence of A-1254, also significantly reduced the IVF rate. Capacitation of sperm in A-1254-containing medium, followed by coculture with untreated oocytes, failed to affect the IVF rate. No significant effect on sperm motility was observed following exposure to 1 and 10 micrograms/mL of A-1254. Estradiol-17 beta also reduced the IVF rate, however, the effect of A-1254 was more severe compared to the estradiol treatment. Furthermore, addition of A-1254 to the embryo culture medium was associated with a significant decrease in embryo growth at 48 h and 96 h. These results demonstrate adverse effects of A-1254 on oocytes, IVF, and embryonic development in the mouse.

Animals↗
PubMedDate not supplied

Effects of polychlorinated biphenyls (PCBs) on in vitro fertilization in the mouse.

Polychlorinated biphenyls (PCBs) are industrial chemicals that are long-lasting global environmental contaminants. PCBs have been reported to adversely affect reproduction in laboratory and wild animals by reducing the incidence of breeding and the survival rate of young. The present study was undertaken to determine the toxic potential of PCBs on in vitro fertilization (IVF) in the mouse. Aroclor 1221, 1254, and 1268, and 3, 3', 4, 4'-tetrachlorobiphenyl (TCB), a PCB congener, were added to IVF medium at various concentrations (0.01, 0.1, 1, and 10 micrograms/mL). Cumulus masses containing oocytes were obtained from superovulated B6D2F1 mice and cultured in medium containing PCB to which capacitated sperm were added. Oocytes were assessed for fertilization 20 to 24 h after insemination. A-1221, A-1268, and TCB reduced the fertilization rate at the 1 microgram/mL and 10 micrograms/mL doses, while inhibition of fertilization by A-1254 reached significance at 0.1 microgram/ml. Furthermore, all of these chemicals caused an increased incidence of degenerative ova and abnormal 2-cell embryos at the higher dose levels (1 microgram/mL and 10 micrograms/mL). The results suggest that higher dosages of PCB and TCB adversely affect fertilization and cause an increased incidence of degeneration of oocytes and abnormality in the early mouse embryos.

Animals↗
PubMedDate not supplied

Enhanced production of monomeric interferon-beta by CHO cells through the control of culture conditions.

The enhancement of recombinant protein expression of a transfected cell line is essential for the development of an efficient large-scale bioprocess. The effect of various media additives and temperature conditions were studied in an attempt to optimize protein production, stability, and protein glycosylation from a Chinese hamster ovary (CHO) cell line producing human beta-interferon (Hu-beta-IFN). We observed a decrease in the ELISA response of the glycoprotein in the later stages of batch cultures, which was attributed to molecular aggregation. Cells were subjected to various concentrations of glycerol, dimethyl sulfoxide (DMSO), and sodium butyrate (NaBu) in a variety of culture systems and conditions. The addition of both NaBu and DMSO resulted in higher specific productivities but reduced growth rates that resulted in a net reduction of interferon produced. Glycerol appeared to stabilize the secreted beta-IFN, resulting in reduced aggregation, despite a decrease in cell growth rate. Glycosylation analysis of isolated beta-IFN showed a time-dependent decrease in sialylation in batch culture that was ameliorated by the presence of glycerol. Low-temperature conditions (30 degrees C) had the greatest effect on productivity with a significant increase in beta-IFN titer as well as a reduction in the degree of molecular aggregation.

Animals↗
PubMedDate not supplied

The clinical significance of pericentric inversion of the human Y chromosome: a rare "third" type of heteromorphism.

A 28-year-old normal East Indian was found to have a pericentric inversion of the Y chromosome. After reviewing the literature, it was concluded that an inverted Y chromosome does not impede the production of normal sperm and does not predispose to non-disjunction of other chromosomes in the progeny. Thus, the earlier concept of nondisjunction was rejected, and it is suggested that aberrant cases with aneuploidy and an inverted Y are fortuitous. The pericentric inverted Y is inherited from generation to generation and has no clinical significance. The prevalence of males with pericentric Y inversion in the general population is approximately 1 per 1000. It is suggested that a pericentric inversion of the Y chromosome is a rare chromosomal heteromorphism and should be called type III.

Adult↗
PubMedDate not supplied

MR imaging of intraventricular cysticercosis.

Three cases of cysticercosis with cysts located in the cerebral ventricles were studied with magnetic resonance (MR) imaging. This technique proved to be diagnostically superior to CT. In fact, MR can effectively replace metrizamide CT ventriculography in the detection of intraventricular cysticercosis.

Adult↗
PubMedDate not supplied

Cataract and uveitis management by pars plana lensectomy and vitrectomy by ultrasonic fragmentation.

Cataract and uveitis occurs usually in young individuals and produces loss of vision from opacification of both the lens and vitreous. The condition does not lend itself to conventional surgery. In the experience of the authors and several other investigators, pars plana lensectomy and vitrectomy by ultrasonic fragmentation not only improves vision but apparently causes a remission of uveitis. A retrospective study of 23 eyes with cataract and uveitis undergoing pars plana lensectomy and vitrectomy by ultrasonic fragmentation (21 eyes) or vitrectomy alone (2 eyes) showed improved vision in 91.3%, no operative complications, and remission of the uveitis in 100% with observation periods of 1-11 years (average, 5 years). Pars plana lensectomy and vitrectomy appears to be the treatment of choice in cataract and chronic uveitis.

Adolescent↗
PubMedDate not supplied

Ultrastructural study of the osteointegration of bioceramics (whitlockite and composite beta-TCP + collagen) in rabbit bone.

Study examines the osteointegration of two porous ceramic implants, beta-tricalcium phosphate (beta-TCP) and a composite (beta-TCP-collagen), in femur and tibias of 20 New Zealand white rabbits, which were sacrificed 1 week and 1, 4, and 12 months postimplant so that radiological, optical microscopic, and ultrastructural studies could be carried out. The results show a progressive degradation and resorption of both implant materials by means of a macrophagic reaction, which is at its most intense 1 month postimplant. The materials are substituted by newly formed bone tissue starting at the host bone-implant interface, the substitution being almost total by the end of the study, although less completely and earlier than in the case of the composite. Both materials can be considered as potential substitutes for bone tissue since they are biocompatible, bioreabsorbable, and osteogenic.

Animals↗
PubMedDate not supplied

Immunohistochemical characterization of pineocytomas.

The immunoreactivity of a panel of poly- and monoclonal antibodies raised against different neuronal and glial antigens, was studied in paraffin-embedded specimens of five pineocytomas. Antibodies against neuron-specific enolase (NSE), S-100 protein, neurofilaments protein (NFP), glial fibrillar acidic protein (GFAP), myelin basic protein (MBP), Synaptophysin (SYN) and vimentin were used. NSE immunoreactivity was detectable in nearly all tumoral cells. S-100 expression was present in all tumors, but a significant variation in the number of S-100 positive cells was noted in the different specimens; they ranged from 3% of S-100 positive cells in some areas of case 1, to 30% in other areas of case 4. The number of GFAP-positive cells detected in four of the five tumors was minimal. In the remaining tumor, 10% to 14% the positively GFAP antisera-stained cells could be seen in some areas; this tumor was considered a pineocytoma with astrocytic differentiation. MBP immunoreactivity was found in isolated cells only in one tumor. Neurofilaments or vimentin expression could not be found in tumoral cells. Synaptophysin was studied in two tumors (cases 4 and 5). Both tumors showed a fine granular neuropil pattern of immunoreactivity, but only in isolated cells of case 5, occasional cytoplasmic positivity could be determined. Based upon our results we can conclude that NSE and synaptophysin are markers that may be applied in the diagnosis of pineocytomas. Further, our results support the hypothesis that the tumoral cells in these neoplasms are of neuroendocrine origin.

Adolescent↗
PubMedDate not supplied

Continuous infusion epidural anesthesia during labor: a randomized, double-blind comparison of 0.0625% bupivacaine/0.002% butorphanol and 0.125% bupivacaine.

The efficacy of pain relief and the maternal and neonatal effects of continuous epidural infusion of 0.0625% bupivacaine/0.002% butorphanol was compared with the infusion of 0.125% bupivacaine alone in a randomized, double-blind study of 32 women in labor. A test dose of 2 ml 0.5% bupivacaine was given to every patient and followed by two epidural regimens in randomized, double-blind manner. Group B-B (bupivacaine/butorphanol) patients received 7.5 ml 0.125% bupivacaine plus 1 mg butorphanol (0.5 ml) followed by an infusion of 0.0625% bupivacaine/0.002% butorphanol at a rate of 12 ml/hour; Group B (bupivacaine alone) patients received 8 ml 0.25% bupivacaine followed by an infusion of 0.125% bupivacaine at a rate of 12 ml/hour. A bolus of 5 ml 0.125% bupivacaine or 0.0625% bupivacaine was given to Group B or B-B, respectively, if additional pain relief was required. Infusion of B-B combination resulted in similar pain relief and fewer patients with motor block than bupivacaine alone; 12% versus 38% in Groups B-B and B, respectively, had motor weakness. A smaller dose of bupivacaine was used in the B-B group compared to the B group; 71 +/- 14 versus 99 +/- 13 mg (mean +/- SEM; p less than 0.05). Progress of labor and the mode of delivery did not differ significantly between the two groups. All infants were vigorous and had normal acid-base status and neurologic adaptive capacity scores. Butorphanol appears to be useful as an adjunct to epidural bupivacaine for continuous epidural infusion during labor without adversely affecting the mother or the neonate.

Adult↗