Co-localization of the tumor-suppressor protein p53 and human papillomavirus E6 protein in human cervical carcinoma cell lines.

The loss of the tumor-suppressor activity of p53, either by mutation or by interaction with the human papillomavirus (HPV) E6 protein, is considered to be an important mechanism in the carcinogenesis of cervical cancer. We have studied the cytological distribution of these proteins in human cervical carcinoma cell lines using polyclonal anti-p53 and monoclonal anti-E6 antibodies. The antibody specificity was confirmed by immunoblot and immunocompetition analyses.

Inhibition of Na+/H+ exchange preserves viability, restores mechanical function, and prevents the pH paradox in reperfusion injury to rat neonatal myocytes.

Rat neonatal myocytes exposed to 2.5 mM CaCN and 20 mM 2-deoxyglucose at pH 6.2 (chemical hypoxia) quickly lose viability when pH is increased to 7.

Intracellular pH and Ca2+ homeostasis in the pH paradox of reperfusion injury to neonatal rat cardiac myocytes.

Ischemia is characterized by anoxia and a large decrease of tissue pH. After a critical period of ischemia, reperfusion precipitates irreversible injury. Previous work showed that reperfusion injury to cultured neonatal myocytes was precipitated by a rapid return to physiological pH, a "pH paradox" (Bond, J.

Massive bleeding from rectal varices.

An elderly female who experienced a life-threatening bleed from an isolated rectal varix is presented. She failed endoscopic injection sclerotherapy but responded to surgical ligation. The literature concerning well-documented bleeding from eight cases of rectal varices is reviewed.

A brain-tumor model utilizing stereotactic implantation of a permanent cannula.

A tumor model involving stereotactically implanted culture-reared tumor cells is presented. Stainless steel cannulas were stereotactically and permanently implanted into the caudate nucleus of 30 rats. The animals were separated into two groups.

Detection of hepatitis B viral DNA by polymerase chain reaction in dialysis patients.

The polymerase chain reaction (PCR) was used to search for hepatitis B virus (HBV) DNA sequences in the sera of 51 dialyzed patients (26 women, 25 men; mean age 60.5 years, range 35 to 85). Two different sets of specific primers for HBV core and surface gene sequences were synthesized and used for each sample.

Mitochondrial and glycolytic dysfunction in lethal injury to hepatocytes by t-butylhydroperoxide: protection by fructose, cyclosporin A and trifluoperazine.

In isolated mitochondria, t-butylhydroperoxide (t-BuOOH) and other pro-oxidants cause a permeability transition characterized by increased permeability to small ions, swelling and loss of membrane potential. Cyclosporin A and trifluoperazine inhibit this permeability transition. Here, we investigated the role of the mitochondrial permeability transition in lethal cellular injury from t-BuOOH.

Mitochondria as a source of reactive oxygen species during reductive stress in rat hepatocytes.

Cell killing, oxygen consumption, and hydroperoxide formation were determined in rat hepatocytes after glycolytic and respiratory inhibition. These conditions model the ATP depletion and reductive stress of anoxia ("chemical hypoxia"). Glycolysis was inhibited with iodoacetate, and mitochondrial electron transfer was blocked with sodium azide, cyanide, or myxothiazol.

Effect on verapamil on ventricular function: studies in denervated human heart.

Verapamil has complex influences on ventricular function owing to its direct myocardial effects, vasodilation, and reflex activation of the sympathetic nervous system. To investigate the direct myocardial effects of verapamil in humans independent of reflex sympathetic stimulation, we administered the drug to 13 recent heart transplant recipients with denervated ventricles. Hemodynamics and radionuclide angiograms were recorded at baseline, with altered loading conditions, and after intravenous (i.

Noninvasive pressure support ventilation in patients with acute respiratory failure.

To further delineate indications for noninvasive pressure support ventilation (NIPSV), we proposed this noninvasive technique as an alternative to endotracheal intubation in 17 consecutive patients with acute respiratory failure from various causes. Eight patients (47 percent) were successfully ventilated with NIPSV, while in 9 (53 percent), NIPSV failed. Gas exchange values before initiating NIPSV were different between the 2 groups: patients successfully ventilated with NIPSV had a higher PaCO2 (57 +/- 15 mm Hg vs 37 +/- 17 mm Hg; p = 0.

Diastolic dysfunction in cardiac transplant recipients: an important role in the response to increased afterload.

We evaluated the hemodynamic and functional response to acute elevations in left ventricular (LV) afterload in 22 recent recipients of cardiac transplants to determine whether abnormalities in LV diastolic function influence the response to this intervention. In seven patients (group 1) LV ejection fraction decreased significantly from baseline values (> or = 5%) during methoxamine infusion, whereas in 15 patients (group 2) LV ejection fraction was maintained. Peak filling rate was lower in group 1 versus group 2 (3.

Antibiotic-associated fulminant pseudomembranous colitis without toxic megacolon.

Presented is a middle-aged male who developed a fulminant case of antibiotic-associated pseudomembranous colitis characterized by leukocytosis, hypoalbuminemia, ascites, and anasarca without toxic megacolon. The patient responded slowly to medical therapy consisting of intravenous metronidazole, oral vancomycin, and parenteral nutrition. Subsequently, cholestyramine was administered.

Transforming growth factor-beta (TGF-b) induced phosphorylation of the myristoylated alanine rich C kinase substrate (MARCKS) protein in ovarian granulosa cells is modulated by follicle stimulating hormone (FSH).

The mechanism by which TGF-b1 affects granulosa cell physiology as well as the modulation of TGF-b1 activity by FSH are not understood. We tested the hypothesis that TGF-b1 exerts its effects on granulosa cells via activation of protein kinase C (PKC). Immunoprecipitation of the MARCKS protein from 32P labeled rat granulosa cells was used to assay PKC activation.

Cytotoxicity screening of surfactant-based shampoos using a multiwell fluorescence scanner: Correlation with Draize eye scores.

The irritancy potential of seven shampoos was evaluated by a rapid cytotoxicity assay in cultured human keratinocytes and rat hepatocytes. Loss of cell viability was estimated from increases in propidium iodide fluorescence measured using a multiwell fluorescence scanner. The concentration of shampoo causing a 50% loss of cell viability after 15 min of incubation (V(50)) was determined by probit analysis.

Synergism of cyclosporin A and phospholipase inhibitors in protection against lethal injury to rat hepatocytes from oxidant chemicals.

Cyclosporin A and phospholipase inhibitors block the oxidant-induced mitochondrial permeability transition. Here, protection by these agents against cytotoxicity of oxidant chemicals was evaluated in rat hepatocytes. The combination of cyclosporin A and a phospholipase inhibitor (trifluoperazine, mepacrine, or dibucaine), but neither alone, substantially protected against lethal injury from 0.

A novel cytotoxicity screening assay using a multiwell fluorescence scanner.

A new assay using a multiwell fluorescence scanner was developed for screening cytotoxicity to cells cultured in 96-well microtiter plates. The assay is based on binding of propidium iodide to nuclei of cells whose plasma membranes have become permeable due to cell death. Fluorescence of propidium iodide measured with a multiwell fluorescence scanner increased in proportion to the number of permeabilized cells.

Effectiveness of latex condoms as a barrier to human immunodeficiency virus-sized particles under conditions of simulated use.

Condoms were tested in an in vitro system simulating key physical conditions that can influence viral particle leakage through condoms during actual coitus. The system quantitatively addresses pressure, pH, temperature, surfactant properties, and anatomical geometry. A suspension of fluorescence-labeled, 110-nm polystyrene microspheres models free human immunodeficiency virus (HIV) in semen, and condom leakage is detected spectrofluorometrically.

Platelet-derived growth factor (PDGF) alpha receptor activation modulates the calcium mobilizing activity of the PDGF beta receptor in Balb/c3T3 fibroblasts.

In order to determine whether distinct platelet-derived growth factor (PDGF) receptors (alpha and beta) can modulate the activity of one another, PDGF isoform (AA, BB, and AB)-stimulated changes in Ca2+i were monitored by digitized video microscopy in single cells upon sequential addition of PDGF isoforms. In Balb/c 3T3 fibroblasts, all PDGF isoforms were capable of stimulating increases in Ca2+i of 200-600% above basal levels, although with different potencies: BB greater than or equal to AB greater than AA. All cells were BB-PDGF-responsive, but only 74% of cells examined responded to AA-PDGF.

Quantitative precision of an automated, fluorescence-based image cytometer.

Digital image-based cytometry of clinical specimens labeled with fluorescent, disease-specific markers holds promise for becoming an important diagnostic and prognostic technique because the technique can make a diverse range of quantitative biochemical, morphologic, densitometric and contextual measurements on intact specimens. It has been previously shown by us, using an image cytometer (IC) consisting entirely of commercially available components, that the nuclei of individual cells in slide-supported specimens can be detected automatically using a fluorescent DNA stain and image analysis software. The purpose of this study was to determine the precision of the IC for quantifying the integrated fluorescence intensity and area of fluorescent standard beads and nuclei.

Fura-2 measurement of cytosolic free Ca2+ concentration in corpus allatum cells of larval Manduca sexta.

Cytosolic free Ca2+ has been implicated in the regulation of the larval corpus allatum (CA) of the tobacco hornworm Manduca sexta since agents presumed to cause changes in intracellular Ca2+ concentrations affect both basal and neuropeptide-modulated synthesis/release of the juvenile hormones. To determine whether differences in cytosolic free [Ca2+] in CA cells were associated with different levels of gland activity, methods were developed for dissociating CA cells with the retention of biosynthetic activity and for uptake by the dissociated cells of the fluorescent Ca2+ indicator Fura-2. Digitized fluorescence microscopy of the Fura-2-loaded cells enabled measurement of intracellular Ca2+ levels in individual cells.

Cytosolic free Ca2+ and proteolysis in lethal oxidative injury in endothelial cells.

Oxygen free radicals (OFR) are thought to mediate ischemia-reperfusion injury to endothelium of heart, lung, brain, liver, and kidney and contribute to development of atherosclerosis, pulmonary O2 toxicity, and adult respiratory distress syndrome. Increased cytosolic free Ca2+ (Cai2+) has been proposed as a mechanism of injury from oxidative stress, yet the pathways by which an increase in Cai2+ may cause OFR-mediated endothelial cell injury remain unknown. Using multiparameter digitized video microscopy and the fluorescent probes, fura-2 acetoxymethyl ester and propidium iodide, we measured Cai2+ and cell viability in human umbilical endothelial cells during oxidative stress with xanthine (50 microM) plus xanthine oxidase (40 mU/ml).

Suppression of Ca2+ oscillations in cultured rat hepatocytes by chemical hypoxia.

The model of "chemical hypoxia" with KCN plus iodoacetic acid mimics the ATP depletion and reductive stress of hypoxia. Here, we examined the effects of chemical hypoxia on cytosolic free Na+ and Ca2+ in single cultured rat hepatocytes by multiparameter digitized video microscopy and ratio imaging of sodium-binding furan indicator (SBFI) and Fura-2. Intracellular Na+ increased from about 10 mM to more than 100 mM after 20 min of chemical hypoxia, whereas cytosolic free Ca2+ remained virtually unchanged.

Mechanism of cellular uptake of modified oligodeoxynucleotides containing methylphosphonate linkages.

The cellular uptake and intracellular distribution of methylphosphonate oligonucleotides (15 mers) has been examined using both 32P labeled and fluorescent labeled oligonucleotides. The cellular uptake process for methylphosphonate oligonucleotides is highly temperature dependent, with a major increase in uptake occurring between 15 and 20 degrees C. Most of the label which becomes cell associated at 37 degrees C cannot be removed by acid washing or trypsinization and thus seems to be within the cell.

Protection by acidotic pH against anoxia/reoxygenation injury to rat neonatal cardiac myocytes.

We assessed the effect of acidosis on cell killing during anoxia and reoxygenation in cultured rat neonatal cardiac myocytes. After 4.5 hours of anoxia and glycolytic inhibition with 2-deoxyglucose, loss of viability was greater than 90% at pH 7.