Coinduction of glucose-regulated proteins and doxorubicin resistance in Chinese hamster cells

The glucose-regulated protein (GRP) system in mammalian cells is induced by glucose deprivation, anoxia, the calcium ionophore A23187, and 2-deoxyglucose. In Chinese hamster ovary cells the major GRPs are approximately equal to 76, 97, and 170 kDa. Removal of each of these four GRP-inducing stresses leads to the coordinate repression of GRPs and induction of the major heat shock proteins at 70 and 89 kDa. The application of each of these four GRP-inducing conditions leads to a significant induction of resistance to the drug doxorubicin. Removal of each GRP-inducing condition results in the rapid disappearance of this resistance in a manner that correlates with the repression of the GRPs. The retention of doxorubicin by GRP-induced cells does not explain the induced drug resistance. When the RIF in vitro/in vivo tumor system is probed with an antibody against the 76-kDa GRP, a significant increase in this GRP is observed in cells obtained from the central regions of tumors. Since hypoxia and/or nutrient deprivation can occur during tumor development, a GRP-induced state in the tumor may confer resistance to doxorubicin treatment.

The effect of nitroimidazoles on glucose utilization and lactate accumulation in mouse brain

The radiation sensitizers misonidazole (MISO) and desmethylmisonidazole (DMM) can produce central and peripheral neuropathy in patients and laboratory animals. Behavioral and pathological investigations have indicated that in the central nervous system this primarily involves the cochlear and vestibular systems. Nitroimidazoles can also interfere with glycolysis in vitro under aerobic and anaerobic conditions. In the present work we have studied the effect of MISO or DMM on lactate production and glucose utilization in mouse brain. It is observed that these compounds result in a 25% inhibition of lactate production in brain slices relative to the control at a 10 mM level. Additionally, MISO (1.0 mg/g/day) or DMM (1.4 mg/g/day) were administered daily (oral) for 1, 4, 7, or 14 days to examine the effect of these two drugs on the regional glucose utilization in C3Hf mouse brain. Five microcuries of 2-deoxy[14C]glucose was given following the last drug dose and autoradiographs of serial brain sections were made and analyzed by a densitometer. Following a single dose of either MISO or DMM, no significant differences in glucose uptake were observed when compared with controls. However, following 4, 7, and 14 doses the rate of glucose utilization was significantly reduced in the intoxicated animals. Larger reductions were measured in specific regions including the posterior colliculus, cochlear nuclei, vestibular nuclei, and pons with increasing effects observed at later stages. These results share a degree of correspondence with the regional brain pathology produced by these nitroimidazoles.

Association between the mammalian 110,000-dalton heat-shock protein and nucleoli

A rabbit antiserum has been prepared using as antigen the 110,000-dalton mammalian heat-shock protein. This protein was purified for injection by two-dimensional PAGE of heat-shocked Chinese hamster ovary cells. Characterization by immunoautoradiography and immunoprecipitation reveals that the antiserum is specific for the 110,000-dalton protein. Both techniques also reveal that the protein against which the antiserum is directed is induced by heat shock. Indirect immunofluorescence shows that the antigen is primarily localized at or near the nucleolus in cultured cells and numerous murine tissues. Treatment of cultured cells with deoxyribonuclease destroys the organization of staining within the nucleus while ribonuclease appears to completely release the antigen from the nucleus. A binding of the antiserum to cytoplasmic structures is also observed by immunofluorescence. This association with nucleoli may have implications in the regulatory aspects of the heat-shock response.

Biochemical characterization of glucocorticoid receptors of rat testis

Rat testis cytosolic glucocorticoid receptors were characterized by DEAE-cellulose chromatography, Sephadex G-100 columns and sucrose-density gradients. The unactivated [3H]dexamethasone-receptor complex showed two distinct peaks of macromolecular bound radioactivity on DEAE-cellulose chromatography. Peak I eluted just after the column wash, while peak II eluted at 0.28 M KCl. Activation of the complex at 25 degrees C for 45 min resulted in a significant increase in peak I with a concomitant decrease in peak II and the appearance of a third peak at 0.18 M KCl. Both the unactivated and activated [3H]dexamethasone-receptor complex, when analyzed on Sephadex G-100 columns, showed a single macromolecular bound radioactive peak having a Stokes radius of 6.5 nm. Treatment of the [3H]dexamethasone-receptor complex (6.5 nm holo-receptor) with trypsin (0.5 microgram/ml) resulted in the appearance of a smaller (2.0 nm) fragment but no intermediate sized forms of the receptor were observed. The complexes sedimented as 7-8 S (in low salt) and as 4.6 S (in high salt) forms in sucrose gradients in the presence or absence of 10 mM molybdate. Steroid unbound receptors were inactivated at 25 degrees C and 4 degrees C with a T 1/2 of 2 h and 24 h, respectively. Ten mM molybdate slightly protected the unbound testis receptor at 25 degrees C. However, molybdate, dithiothreitol, and molybdate plus dithiothreitol were unable to either enhance or reactivate [3H]dexamethasone binding of unbound receptors at 4 degrees C or 25 degrees C. Activation of testis [3H]dexamethasone-receptor complexes resulted in a 2-3 fold enhancement in subsequent binding to testis nuclei in vitro. In addition, we observed that activated [3H]dexamethasone-receptor complexes were precipitated with 30-35% ammonium sulfate, while unactivated complexes were precipitated with 30-40% ammonium sulfate.

Insight Into Strontium and Calcium Sulfate Scaling Mechanisms in a Wet Producer

Summary

On-going field scaling tests have provided a unique opportunity to study how strontium sulfate and calcium sulfate scales are formed in an oil-producing well. Results indicate that development of nucleation sites on tubing surfaces is the most critical step. Scale profiles within a wellbore are determined mainly by kinetics of crystallization, well-fluid dynamics, and tubing surface characteristics and, especially, synergistic effects of these factors.

Introduction

Scaling is a problem frequently encountered in oil fields. Calcium carbonate, calcium sulfate, and barium sulfate scales have been cited often in the literature. More recently, strontium sulfate scaling problems have been reported from oil fields in the problems have been reported from oil fields in the U.A.E. and Algeria. Mixing of chemically incompatible waters as a result of waterflooding is a primary cause for concern. Literature studies relating to the prognosis, actual occurrence, prevention, and control of oilfield scaling have been reviewed. Many factors are involved in oilfield scaling. In addition to thermodynamic considerations involving temperature, pressure. and water compositions, other factors, such as adherence. kinetics of crystallization, fluid dynamics in a producing well, and the adsorption of foreign material onto growing crystal surfaces may all be important in scale buildup. Better understanding of scaling mechanisms will help improve methods for scale prediction and mitigation. Unfortunately, direct studies of scaling mechanisms under actual or simulated field production conditions are limited. The Arabian American Oil Co. (ARAMCO) has recently concluded a series of simulated field scaling tests. The tests were designed to determine the extent of potential scaling problems that may occur as a result of potential scaling problems that may occur as a result of the seawater flood initiated in June 1978. The seawater flood, the initial Wasia waterflood, and the connate Arab-D formation water, form a three-water system with a possible incompatibility problem. The study of this problem was reported by Lindlof and Staffer. Since problem was reported by Lindlof and Staffer. Since then, additional tests have been carried out to determine the optimal method for scale inhibition. The results have provided extensive insight into the scaling mechanisms provided extensive insight into the scaling mechanisms in a wet producing well.

Field Scaling Tests

The initial sequence of field scaling tests concluded that sulfate scaling encountered in one of the four test wells proved that there is a potential scale problem when the three incompatible waters are allowed to mix in the wellbore. Subsequent tests, designed to mitigate or to prevent scale formation, were carried out on the scaling well discovered in the initial tests. The test well (Fig. 1) is produced through a 4 1/2-in. production string landed at the midpoint of a production string landed at the midpoint of a 170 × 6 1/4-in. open hole interval. The production string is set in a 9 5/8 × 7-in. casing configuration without a production packer. production packer.

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An MMPI subscale (Gd): to identify males with gender identity conflicts

This study reported on the development and cross-validation of a 31-item MMPI Gender Dysphoria subscale (Gd) which accurately discriminates between gender identity patients and matched controls, and identifies males with gender dysphoria syndrome. Both the validity and reliability of the Gd scale has been demonstrated and there is every expectation that the scale has excellent potential for clinical usage. In the construction of the Gd scale, we have addressed the major methodological problems of previous studies which have used psychological tests to assess gender role and identity disturbances: small criterion groups, a lack of an appropriate control group, and prediction of too many false positives.

The development of the dog nigrostriatal system in organotypic culture

Portions of the midbrain and the caudate nucleus from newborn dog (1-3 days old) were maintained in explant culture for periods up to 15 weeks. During that time, nerve cells developing in the midbrain explants projected axons into the explants of caudate. Fluorescence microscopic observations indicated that a large number of projective fibers contained catecholamines with many fluorescing terminals visible in caudate explants. Ultrastructural study disclosed synapses in both midbrain and caudate explants. Some axonal profiles in the caudate were compatible with the appearance of catecholaminergic synapses. Neurochemical analysis showed that the nigrostriatal cultures were capable of dopamine uptake and release.

Specific Pseudomonas immunoglobulin E antibodies in sera of patients with cystic fibrosis

Immunoglobulin E antibodies to Psuedomonas aeruginosa were demonstrated in patients with cystic fibrosis colonized with the bacterium.