Bioflavonoid effects on the mitochondrial respiratory electron transport chain and cytochrome c redox state.

The polyphenolic structure common to flavonoids enables them to donate electrons and exert antioxidant activity. Since the mitochondrial electron transport chain consists of a series of redox intermediates, the effect of flavonoids in a complex mixture of polyphenols, as well as related pure flavonoids, was evaluated on the rat liver mitochondrial electron transport chain. A French maritime pine bark extract (PBE), a complex mixture of polyphenols and related pure flavonoids, was able to reduce cytochrome c reversibly, possibly by donation of electrons to the iron of the heme group; the donated electrons can be utilized by cytochrome c oxidase.

Alpha4 integrins regulate the proliferation/differentiation balance of multilineage hematopoietic progenitors in vivo.

We investigated roles of alpha4 integrins during hematopoiesis using mutant and chimeric mice. Yolk sac erythropoiesis and migration of hematopoietic progenitors to fetal liver, spleen, and bone marrow can occur without alpha4 integrins. Although terminal differentiation of these progenitors is possible without alpha4 integrins, these receptors are essential to maintain normal hematopoiesis in fetal liver, spleen, and bone marrow microenvironments.

The insulin-like growth factor system in the GT1-7 GnRH neuronal cell line.

Evidence suggests that insulin-like growth factors (IGFs; IGF-I and IGF-II) are involved in the regulation of reproductive function including the development of the gonadotropin-releasing hormone (GnRH) neuronal system and the modulation of GnRH secretory activities. To further characterize the regulatory role of the IGF system on GnRH neuronal function, we have examined the gene expression of IGF-I, IGF-II, IGF-I receptor (IGF-IR), and IGF-binding proteins (IGFBPs) in a GnRH neuronal cell line (GT1-7 cells). The relative effects of IGFs and insulin on GnRH secretion by these cells was also investigated.

[Development of Escherichia coli strands resistant to quinolones in stools of patients with liver cirrhosis submitted to selective bowel decontamination].

Background: Selective intestinal decontamination (SID) with norfloxacin in patients with cirrhosis may promote the development of quinolone-resistant (QR) gram-negative bacteria in stools. It is not known wether this fact may become a predisposing factor for the development of infections due to these bacteria.

Material And Methods: We designed a prospective study to evaluate the incidence of Escherichia coli in stools at admission in patients with cirrhosis that had previously received norfloxacin as primary or secondary prophylaxis of spontaneous bacterial peritonitis (SBP) (group I, n = 28) vs those who did not (group II, n = 55).

Enterogastric reflux mimicking gallbladder disease: detection, quantitation and potential significance.

Objective: Visualization of enterogastric reflux (EGR) may be present during hepatobiliary imaging. Reflux of bile may damage the gastric mucosa, altering its function, and cause such symptoms as epigastric pain, heartburn, nausea, intermittent vomiting and abdominal fullness. These symptoms also are associated with gallbladder disease.

Development of quinolone-resistant strains of Escherichia coli in stools of patients with cirrhosis undergoing norfloxacin prophylaxis: clinical consequences.

Background/aim: Norfloxacin prophylaxis decreases the incidence of bacterial infections in high-risk cirrhotic patients, but may promote the development of quinolone-resistant gram-negative bacteria in stools, and eventually lead to infections due to these bacteria. The aim of the study was to evaluate the prevalence of quinolone-resistant strains of E. coli in stools on admission, and the characteristics of any nosocomial infections.

Protective role of ubiquinone in vitamin E and selenium-deficient plasma membranes.

We have studied the effects of dietary depletion of vitamin E and selenium on endogenous ubiquinone-dependent antioxidant system. Deficiency induced an increase in both coenzyme Q9 and Q10 in liver tissue, reaching a maximum between 4 and 7 weeks of deficient diet consumption. Cytochrome b5 reductase polypeptide was also enriched in membranes after 5 weeks of deficient diet consumption.

SAR models for estimating the percutaneous absorption of polynuclear aromatic hydrocarbons.

A structure-activity relationship (SAR) of the in vitro percutaneous absorption of polycyclic aromatic hydrocarbons (PAH) is described. The data set consisted of 60 three to seven ring PAH. Over 50 numeric descriptors were generated from the modeled molecular structures.

Vitamin E and selenium deficiency induces expression of the ubiquinone-dependent antioxidant system at the plasma membrane.

We have used a model of dietary deficiency that leads to a chronic oxidative stress to evaluate responses that are adaptations invoked to boost cellular defense systems. Long-Evans hooded rats were fed with a diet lacking vitamin E (E) and selenium (Se) for 7 wk from weaning leading to animals deficient in both nutrients (-E -Se). In the absence of an electron donor, liver plasma membranes from these rats were more sensitive to lipid peroxidation, although they contained 40% greater amounts of ubiquinone than the plasma membranes from rats consuming diets with sufficient vitamin E and Se (+E +Se).

Plasma membrane NADH-coenzyme Q0 reductase generates semiquinone radicals and recycles vitamin E homologue in a superoxide-dependent reaction.

We investigated the ability of plasma membrane CoQ reductase (PMQR) purified from pig liver to reduce phenoxyl radicals of a vitamin E homologue, Trolox. We report that NADH-driven one-electron reduction of CoQ0 catalyzed by PMQR produced CoQ0 semiquinone radical and CoQoH2. These in turn, recycle vitamin E homologue, Trolox, via reducing its phenoxyl radical.

[Usefulness of SPECT (single-photon emission-computed tomography) in the detection of coronary disease].

Objective: To evaluate the clinical usefulness of cardiac SPECT in the detection of coronary artery disease, and the relation with the site, number and severity of the angiographic lesions.

Method: We studied 216 patients; with myocardial perfusion imaging with SPECT (T1-201 and/or Tc-99 Sestamibi) and coronary angiogram. We defined the localization of myocardial perfusion defects (anterior, inferior, septal, lateral or apex), and their correlation with coronary angiogram, based on the location, number and severity of coronary angiographic lesions.

Inappropriate gonadotropin secretion in polycystic ovary syndrome: influence of adiposity.

In recent years, there has been uncertainty concerning the association of inappropriate gonadotropin secretion (high LH and normal FSH) and the polycystic ovary syndrome (PCOS). In the present study, we ascertained the influence of body composition on LH pulsatile parameters in 33 PCOS and 32 normal cycling (NC) women across a wide range of body mass index (BMI, 19-42 kg/m2). Twenty four-hour pulsatile parameters for serum LH (10-min sampling) and pituitary gonadotropin responses to i.

DMPS-arsenic challenge test. I: Increased urinary excretion of monomethylarsonic acid in humans given dimercaptopropane sulfonate.

The purpose of the present study was to evaluate in a novel manner the arsenic exposure of humans living in two towns in Northeastern Chile. Residents of one town drink water containing 593 microg As/l. Those in the control town drink water containing 21 microg As/l.

[Simultaneous assessment of perfusion and myocardial viability with 2 isotope studies (thallium at rest and sestamibi in exercise). Initial experience in Mexico and Latin America].

Unlabelled: Rest-stress sestamibi single photon emission computed tomography (SPECT) has sensitivity and specificity similar to those of thallium 201 SPECT for detection of coronary artery disease. However, sestamibi is not ideal agent to study myocardial viability. There is not published experience in Latin American using dual isotope SPECT protocol to evaluate myocardial perfusion and viability.

Vinorelbine as neoadjuvant chemotherapy in advanced cervical carcinoma.

Purpose: To evaluate the efficacy and toxicity of vinorelbine (VNB) as single-agent neoadjuvant chemotherapy in advanced cervical carcinoma (ACC).

Patients And Methods: Between December 1993 and October 1995, 43 untreated patients with stages IIB to IVA squamous cell cervical cancer were entered onto this study. Forty-two patients are assessable for response and 43 for toxicity.

Role of cytochrome b5 reductase on the antioxidant function of coenzyme Q in the plasma membrane.

Cytochrome b5 reductase purified from liver plasma membrane reduces coenzyme Q (CoQ) in reconstituted liposomes in the absence of cytochrome b5. Both CoQ and its reductase are responsible for the reduction of the ascorbate free radical at the cell surface. Thus, NADH-CoQ reductase represents a partial reaction of NADH-AFR reductase in the plasma membrane.

Gallbladder visualization on routine lung perfusion imaging.

Objective: Two routine lung SPECT studies showed what appeared to be uptake within the gallbladder. This finding was confirmed on coronal views and three-dimensional reconstruction. There was no contamination or problem with the radiopharmaceutical quality control.

Congenital factor VII deficiency in a patient with an abdominal aortic aneurysm.

A patient with congenital factor VII deficiency underwent surgery for an inflammatory abdominal aortic aneurysm. No references in the literature have been found on the management of this coagulation defect in patients who require vascular surgery. We present one such case, with special reference to the perioperative management of factor VII replacement therapy.

Differential requirements for alpha4 integrins during fetal and adult hematopoiesis.

Mice chimeric for the expression of alpha4 integrins were used to dissect the roles of these receptors in development and traffic of lymphoid and myeloid cells. During fetal life, T cell development is alpha4 independent, but after birth further production of T cells becomes alpha4 dependent. Precursors for both T and B cells require alpha4 integrins for normal development within the bone marrow.

Characterization of TGF-beta 1-binding proteins in human bone marrow stromal cells.

The proliferation and differentiation of haemopoietic progenitor cells is dependent on their close relation with bone marrow stromal cells, which constitute a source of cytokines as well as expressing receptors for both the cytokines and progenitor cell adhesion molecules necessary for regulated haemopoiesis. We have generated human bone marrow stromal cell cultures and analysed the TGF-beta 1 receptor components expressed by these cells. [125I]TGF-beta 1-affinity labelling experiments showed the involvement of type I and II receptors in the binding of TGF-beta 1, as demonstrated by specific immunoprecipitation of [125I]TGF-beta 1-receptor complexes.

Ifosfamide and cisplatin as neoadjuvant chemotherapy for advanced cervical carcinoma.

A phase II trial was performed to evaluate the efficacy and toxicity of a combination of cisplatin (CDDP) and ifosfamide (IFX) as neoadjuvant chemotherapy in advanced cervical carcinoma (ACC). Between August 1991 and September 1993, 57 untreated patients with stages IIB to IVA were entered into this study. Median age was 44 years (range, 25 to 74 years).

Bilateral mucous cell containing dentigerous cysts of mandibular third molars: report of an unusual case.

A 38-year-old Caucasian male with bilateral dentigerous cysts of the mandibular third molars is reported as follows. The cyst cavities were lined with a nonkeratinized squamous epithelium. Mucous cells were seen in some areas of the cyst walls.