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Biomedical subjects

J Lopez

Publications and source records attributed to J Lopez.

At least 91 records · Page 5Linked to original sources
PubMed1994

Grandmother dishonored: violence against women by male partners in American Indian communities.

Extensive and scrupulously conducted research during the past decade has established the issue of violence against women by male partners as both an international human rights issue and a public health problem of national concern. This research has rarely been extended into communities of color, and, in particular, to American Indian women. This article presents conceptual and methodological factors involved in conducting research with American Indian women, a comprehensive literature review of available data, assertions regarding abuse of women by male partners in American Indian communities, and directions for future research.

Adult↗
PubMed1994

Native valve endocarditis due to Candida parapsilosis: a late complication after bone marrow transplantation-related fungemia.

A case of Candida parapsilosis endocarditis observed 16 months after BMT is reported. The patient, a 35-year-old female with CML, suffered from Candida parapsilosis fungemia on day +22 after BMT. In spite of treatment with amphotericin B, fluconazole and catheter withdrawal, the same yeast was isolated > 1 year later from a vegetation on an old rheumatic mitral valve. Although the patient remained in complete cytogenetical and hematological remission, in vitro tests showed reduced phagocytic and chemotactic capacity of neutrophils and monocytes. This case stresses the need of prolonged therapy for patients with candidemia after BMT.

Adult↗
PubMed1993

Adrenoleukodystrophy gene: unexpected homology to a protein involved in peroxisome biogenesis.

Adrenoleukodystrophy (ALD) is an X-linked peroxisomal disorder characterized by a progressive demyelination of the central nervous system and adrenal insufficiency. Clinical phenotypes of different severity are frequently observed within the same kindred. ALD is characterized biochemically by the accumulation of very-long-chain fatty acids (VLCFA) due to an impairment in the beta-oxidation of these fatty acids in peroxisome. From the observation that oxidation of VLCFA-CoA is normal in fibroblasts from patients with ALD, it was concluded that the gene coding for VLCFA-CoA synthetase was a candidate gene for ALD. Using positional cloning strategies, we have identified a gene which was found partially deleted in 7% of 85 independent patients with ALD. The predicted protein (ALDP) sequence shows significant homology to the 70-kDa peroxisomal membrane protein which is involved in peroxisome biogenesis and belongs to the 'ATP binding' superfamily of transporters. ALDP thus encodes a putative peroxisomal transporter molecule which may be involved in the import or anchoring of VLCFA-CoA synthetase.

Adrenoleukodystrophy↗
PubMed1993

Efficacy and tolerance of an amphotericin B lipid (Intralipid) emulsion in the treatment of candidaemia in neutropenic patients.

The efficacy and tolerance of a new amphotericin B lipid emulsion (AmB-IL) in which amphotericin B was diluted in a lipid solution for parenteral nutrition (Intralipid) was assessed in fourteen episodes of candidaemia occurring in neutropenic patients. The strains isolated were Candida krusei (nine cases), Candida albicans (three cases), Candida parapsilosis (one case) and Candida lusitaniae (one case). An AmB-IL was administered at a mean dosage of 1.18 mg/kg/day (range 0.73-1.55) for 22 days (range 6-62). Flucytosine was added to AmB-IL in 12 patients (mean duration 10.6 days). Chills were noted in only 3/306 infusions of AmB-IL. A mild increase of serum creatinine level from 9.3 +/- 3 mg/L (baseline) to 10.9 +/- 3 mg/L (after completion of AmB-IL) and mild decrease of creatinine clearance from 83 +/- 28 mL/min to 56 +/- 21 mL/min were observed. These changes did not correlate with either daily or total dose of AmB-IL or length of therapy. Seven patients were cured and six improved (patients who subsequently died due to nonfungal cause) with AmB-IL. One patient died due to C. krusei pneumonia. In conclusion AmB-IL is a well-tolerated method of amphotericin B administration. It could facilitate the use of amphotericin B without impairing its efficacy for the treatment of candidaemia in neutropenic patients.

Adult↗
PubMed1993

Regulation of pelvic patch water flow in Bufo marinus: role of bladder volume and ANG II.

This report examines the importance of bladder volume in regulating cutaneous water uptake (Jv, cm3.cm-2.s-1 x 10(-7)) across the ventral pelvic patch and examines the role of angiotensin II (ANG II) and circulation as the regulatory mechanism. Jv in empty-bladder Bufo marinus (bladder volume 3.89 +/- 1.49%, n = 7) was 1,671 +/- 68 (n = 7). Injection of Ringer solution into the bladder (12.8 +/- 2.2%, n = 7) decreased Jv to 1,025 +/- 202 (n = 7). ANG II injected into toads with filled bladders increased Jv in a dose-dependent manner. At 5 micrograms/100 g toad Jv increased by 136 +/- 63 (n = 6), at 50 micrograms/100 g toad by 432 +/- 82 (n = 7), and at 200 micrograms/100 g toad by 620 +/- 142 (n = 5). Saralasin (200 micrograms/100 g toad) completely inhibited the response to ANG II (50 micrograms/100 g toad) and at 1 mg/100 g toad decreased Jv in empty-bladder toads. These experiments indicate that 1) bladder volume participates in the regulation of Jv in the ventral pelvic patch; 2) ANG II increases the Jv in toads with full bladders; 3) saralasin inhibits the high Jv in empty bladder toads; 4) the high Jv, associated with an empty bladder, requires an intact circulation to be maintained; 5) without an intact circulation, the high water flow associated with an empty bladder causes the Na+ content of the tissue in the ventral patch to be reduced; and 6) ANG II causes only a minimal increases in water permeability in the isolated pelvic patch skin.

Angiotensin II↗
PubMed1993

Amylase-producing Bence Jones multiple myeloma with pancreatitis-like symptoms.

Amylase-producing tumors are mainly adenocarcinomas and, in rare instances, multiple myelomas. We describe here a first case of amylase-producing Bence Jones type myeloma with pancreatitis-like symptoms and the second in a Caucasian patient. The finding of salivary-type hyperamylasemia in a 72-year-old female with a possible pancreatitis made us suspect the diagnosis. Amylase production was observed in bone marrow cultures in which 96% of cellularity was composed of plasmablasts. Serum amylase level decreased when chemotherapy was given.

Aged↗
PubMed1993

Respiratory distress syndrome in copper deficiency: an experimental model developed in rats.

An experimental model has been developed to investigate the effect of copper deficiency on lung maturity in the newborn rat. Three groups of female Sprague-Dawley rats were used: the copper-deficient group was fed with a copper-free diet; the control group received a copper-adequate diet, and the pair-fed group was fed with a limited copper diet. After gestation and delivery, 35% of the newborn copper-deficient group showed respiratory distress syndrome (RDS). The neonatal lungs were isolated and processed for ultrastructural and biochemical study: A greater thickness of the air-blood barrier was observed in the lungs of the copper-deficient group, however, no other differences were observed in the rest of the pulmonary structures. Quantitative differences in pulmonary surfactant were not found in the three groups. The thickness of the air-blood barrier might explain the RDS observed in the copper-deficient newborns.

Animals↗
PubMed1993

Perioperative care management for the patient undergoing gynecologic laparoscopy.

Patients undergoing abdominal laparoscopy require a process that is systematic and thorough and that at the same time has the flexibility to adapt to each individual's needs. The use of standards of care will facilitate the delivery of care by all staff, providing important links to standardized perioperative documentation, orientation, and meeting of quality performance indicators. Two examples of standards of care are provided in this article.

Female↗
PubMed1993

Inhibition of visceral protein synthesis by certain amino acid supplements.

This study was focused on the effects produced by diets with different amino acid proportions on visceral protein synthesis (liver and jejunal mucosa). Eight groups of rats received an enteral modular diet supplemented with different amino acids (Group 1: Ile, Leu, Val; Group 2: Phe, Met, Gly; Group 3: Glu, Arg, Gly; Group 4: Gly, Group 5: Orn-Asp, Cys, Pro; Group 6: Lys, Ser, Thr; Group 7: Tyr, His, Ala). Group 8 was the control group. Rats were fed for four days. At the end of this period a flooding dose of 14C-Leu was injected and animals were killed. Liver and jejunal mucosa were removed and protein synthesis rate was determined. Results show a decreased liver protein synthesis in group fed with aromatic amino acids (53.8 +/- 8.4 vs. 88.6 +/- 12.1) and Glu-Arg (68.6 +/- 10.9). In jejunal mucosa there was a decrease of protein synthesis in groups fed with aromatic amino acids (98.7 +/- 16 vs 160.5 +/- 49). These changes seem to be related to the intracellular amino acid pool size and its influence on protein metabolism.

Amino Acids↗
PubMed1992

p65 fragments, homologous to the C2 region of protein kinase C, bind to the intracellular receptors for protein kinase C.

Receptors for activated protein kinase C (RACKs) have been isolated from the particulate cell fraction of heart and brain. We previously demonstrated that binding of protein kinase C (PKC) to RACKs requires PKC activators and is via a site on PKC that is distinct from the substrate binding site. Here, we examine the possibility that the C2 region in the regulatory domain of PKC is involved in binding of PKC to RACKs. The synaptic vesicle-specific p65 protein contains two regions homologous to the C2 region of PKC. We found that three p65 fragments, containing either one or two of these PKC C2 homologous regions, bound to highly purified RACKs. Binding of the p65 fragments and PKC to RACKs was mutually exclusive; preincubation of RACKs with the p65 fragments inhibited PKC binding, and preincubation of RACKs with PKC inhibited binding of the p65 fragments. Preincubation of the p65 fragments with a peptide resembling the PKC binding site on RACKs also inhibited p65 binding to RACKs, suggesting that PKC and p65 bind to the same or nearby regions on RACKs. Since the only homologous region between PKC and the p65 fragments is the C2 region, these results suggest that the C2 region on PKC contains at least part of the RACK binding site.

Amino Acid Sequence↗
PubMed1992

A monoclonal anti-idiotype specific for human polyclonal IgM rheumatoid factor.

One of the hallmarks of rheumatoid arthritis (RA) is the production of high titers of rheumatoid factor (RF) antibody directed against the Fc portion of IgG. Anti-Id that recognize the majority of monoclonal RF from patients with B cell dyscrasias are reactive with only 1 to 2% of these polyclonal RF from RA patients. We describe a new monoclonal anti-Id, 4C9, that recognizes a L chain determinant on polyclonal IgM RF from patients with RA but does not recognize a panel of monoclonal RF from patients with B cell malignancies. 4C9 reactivity is found in the serum of 34/43 RF-positive RA patients and in 12/12 RF-positive synovial fluids, but in only 1/14 RF-negative sera from RA patients and 1/22 sera containing monoclonal IgM RF. 4C9 reactivity is highly enriched in purified IgM RF from nine RA patients and represents a variable percentage of total IgM RF up to a maximum of 23%. Furthermore, 4C9 reactivity is enriched in the synovial fluid of three of five RA patients compared with serum, suggesting that 4C9-reactive IgM RF are synthesized within the joint. IgG RF from RA synovial fluids are not 4C9 reactive, indicating either that different genes are used to encode IgM and IgG RF in RA patients, or that IgG RF have somatically mutated away from idiotypic reactivity.

Antibodies, Anti-Idiotypic↗
PubMed1992

Retrospective evaluation of factors associated with the risk of seropositivity to Ehrlichia risticii in horses in New York State.

A retrospective study was designed to determine the distribution of equine monocytic ehrlichiosis among the equine population in New York state, and to identify factors associated with risk of disease. Serum samples submitted to the diagnostic laboratory of the university during the period from January 1985 through December 1986 were examined for antibodies to Ehrlichia risticii, using the indirect fluorescent antibody technique. Factors evaluated included geographic origin and date of submission of the sample, and age, breed, and sex of the horse. Logistic regression analysis was used to identify which factors were significantly associated with the risk of seropositivity to E risticii, while simultaneously controlling for other factors. Of the 2,579 tested samples, 1,950 (76%) had positive results. Factors significantly associated with risk of seropositivity to E risticii were: breed of the horse (Thoroughbreds were 3 times more likely to have been exposed to E risticii, compared with non-Standardbred, non-Thoroughbred breeds); sex (female horses were 2.7 times more likely to have been exposed, compared with male horses); age of the horse (the risk of being exposed to E risticii increased with age, peaked at around 12 years, and decreased thereafter); and month of submission (horses tested during November and December had the highest odds of being seropositive [odds ratio = 2.1], and horses tested during March through April were least likely to be seropositive [odds ratio = 0.5], compared with horses tested during January and February).

Animals↗
PubMed1991

Intracellular receptors for activated protein kinase C. Identification of a binding site for the enzyme.

Protein kinase C (PKC) isozymes comprise a family of cytosolic enzymes that translocate to different intracellular sites on activation. We have recently characterized at least two intracellular receptor proteins for PKC (termed RACKs for receptors for activated C-kinase) in the Triton-insoluble material of the particulate fraction from neonatal rat heart. Here, we identify a sequence that appears to resemble the PKC binding site on these RACKs. A peptide (peptide I) with the sequence KGDYEKILVALCGGN bound PKC, and binding was markedly increased in the presence of PKC activators. Furthermore, peptide I inhibited PKC binding to RACKs in a dose-dependent manner. These data suggest that these RACKs have a common PKC binding sequence. Since peptide I inhibited PKC binding to RACKs in vitro, it may be a useful tool to inhibit PKC translocation and subsequent function in vivo.

Amino Acid Sequence↗
PubMed1991

Identification of intracellular receptor proteins for activated protein kinase C.

Protein kinase C (PKC) translocates from the cytosol to the particulate fraction on activation. This activation-induced translocation of PKC is thought to reflect PKC binding to the membrane lipids. However, immunological and biochemical data suggest that PKC may bind to proteins in the cytoskeletal elements in the particulate fraction and in the nuclei. Here we describe evidence for the presence of intracellular receptor proteins that bind activated PKC. Several proteins from the detergent-insoluble material of the particulate fraction bound PKC in the presence of phosphatidylserine and calcium; binding was further increased with the addition of diacylglycerol. Binding of PKC to two of these proteins was concentration-dependent, saturable, and specific, suggesting that these binding proteins are receptors for activated C-kinase, termed here "RACKs." PKC binds to RACKs via a site on PKC distinct from the substrate binding site. We suggest that binding to RACKs may play a role in activation-induced translocation of PKC.

Animals↗
PubMed1991

Effect of phentolamine on the relationship between O2 consumption and delivery in sheep.

The oxygen flux challenge test (OFT) has recently been used in critically ill patients as a dynamic test for assessment of the response in oxygen consumption (VO2) to an increase in O2 delivery (QO2). Such a test may indicate whether a patient demonstrates delivery-dependent VO2. However, the increase in whole body VO2 following an increase of QO2 might be due to the agents used for the OFT. In this study, we examined the possibility of obtaining false positive OFT with an alpha-adrenergic antagonist. Five normothermic thiopentone-anaesthetised and mechanically-ventilated (inspired O2 fraction, 0.3; expired CO2 fraction, 0.045-0.055) adult sheep (25-31 kg) were investigated. The QO2 was increased in a stepwise fashion from 200 to 850 ml.min-1 by vasodilatation with intravenous infusion of phentolamine. The VO2 was calculated at each step from the product of arteriovenous. O2 content difference (CO2, a-v) and cardiac output (Qc), the latter being continuously measured with a transit-time ultrasonic flow probe placed around the main pulmonary artery. The VO2 (y) was linearly related to QO2 (x), y = 0.034 (SD 0.024) x + 29.3 (SD 3.9). The relationship between Qc (y) and CO2, a-v (x) was y = 4.6x(-1.12) (n = 69; r2 = 0.75; P = NS compared to the expected relationship for isoconsumption conditions, i.e. where Qc = VO2.(CO2, a-v)(-1). Our data suggested that under stable conditions, an infusion of phentolamine did not sufficiently alter the relationship between Qc and CO2, a-v to invalidate its use for OFT in normal sheep.

Animals↗
PubMed1991

Genotypic identification of pathogenic Mycobacterium species by using a nonradioactive oligonucleotide probe.

Commercial DNA hybridization assays (Syngene, Inc., San Diego, Calif.) utilizing alkaline phosphatase-labeled oligonucleotide probes for the identification of Mycobacterium tuberculosis complex and M. avium complex (MAC) were evaluated with 261 isolates of mycobacteria. On the basis of biochemical criteria, the test for MAC was 98% specific and more sensitive (95 of 99, 95%) than Gen-Probe (88 of 99, 89% sensitivity); the major difference in sensitivity noted between the two systems was related to the hybridization of seven MAC strains to the SNAP X probe. The M. tuberculosis complex probe correctly identified all 62 isolates of M. tuberculosis and all 11 isolates of M. bovis, for a sensitivity of 100%. There were two discrepant reactions with mycobacteria other than M. tuberculosis complex isolates.

Bacteriological Techniques↗