What should a person with relapsing-remitting multiple sclerosis know? - Focus group and survey data of a risk knowledge questionnaire (RIKNO 2.0)

BACKGROUND

Risk knowledge is relevant to make informed decisions in multiple sclerosis (MS). The risk knowledge questionnaire for relapsing-remitting MS (RIKNO 1.0) was developed and piloted in Germany.

OBJECTIVE

To produce a revised RIKNO 2.0 questionnaire using mixed methodology in a European setting.

METHODS

The questionnaire was translated in seven languages. MS patient and health professional (HP) expert feedback was obtained from Germany, Italy, Estonia, Serbia, and the UK. A German web-based survey of RIKNO 2.0 compared the tool with the MS Knowledge Questionnaire (MSKQ), each one used with two versions (with/without a "don't know" DN option).

RESULTS

While RIKNO 2.0 was considered difficult, it was rated as highly educational. One item was reframed, and two new items were added. The web-based German survey (n = 708 completers) showed that the DN version did not increase participation rate and did not produce significantly higher scores. Internal consistency (Cronbach alpha) without SN response was 0.73. RIKNO 2.0 scores showed normality distribution irrespective of the answering format. Item difficulty was high ranging from 0.07 to 0.79. Less than 50% of questions were answered correctly (mean 8.9) compared to 80.4% in the MSKQ (mean 20.1). Higher numeracy competency and education were significantly, albeit weakly, associated to higher scores for both RIKNO 2.0 and MSKQ.

CONCLUSION

Including "don't know" options in knowledge questionnaires does not increase percentage of correct replies. RIKNO 2.0 is a complex questionnaire to be used in an educational context and studies on patient information. The tool is now available in seven languages.

Accounting for the impact of conservation on human well-being

Conservationists are increasingly engaging with the concept of human well-being to improve the design and evaluation of their interventions. Since the convening of the influential Sarkozy Commission in 2009, development researchers have been refining conceptualizations and frameworks to understand and measure human well-being and are starting to converge on a common understanding of how best to do this. In conservation, the term human well-being is in widespread use, but there is a need for guidance on operationalizing it to measure the impacts of conservation interventions on people. We present a framework for understanding human well-being, which could be particularly useful in conservation. The framework includes 3 conditions; meeting needs, pursuing goals, and experiencing a satisfactory quality of life. We outline some of the complexities involved in evaluating the well-being effects of conservation interventions, with the understanding that well-being varies between people and over time and with the priorities of the evaluator. Key challenges for research into the well-being impacts of conservation interventions include the need to build up a collection of case studies so as to draw out generalizable lessons; harness the potential of modern technology to support well-being research; and contextualize evaluations of conservation impacts on well-being spatially and temporally within the wider landscape of social change. Pathways through the smog of confusion around the term well-being exist, and existing frameworks such as the Well-being in Developing Countries approach can help conservationists negotiate the challenges of operationalizing the concept. Conservationists have the opportunity to benefit from the recent flurry of research in the development field so as to carry out more nuanced and locally relevant evaluations of the effects of their interventions on human well-being.

Osteoclasts can be induced in fish having an acellular bony skeleton

Kelp bass (Paralabrax clathratus) and leopard sharks (Triakis semifasciata) are characterized by an acellular (anosteocytic) bony skeleton and a focally calcified cartilaginous endoskeleton, respectively. These skeletal forms are not considered to function as mineral reservoirs. Previous studies showed that implanted bone particles are resorbed in rats by large multinucleated cells with ultrastructural features (ruffled borders) characteristic of osteoclasts. We tested the ability of fish to resorb bone matrix and to adapt to reduced salinity conditions. Bone particles were implanted in sharks and bass maintained in seawater (34 ppt, 40.5 mg of calcium per dl) or in diluted seawater (26 ppt, 28.5 mg of calcium per dl). Sera and elicited tissues were harvested 4 weeks later. In sharks, bone particles were not resorbed, and multinucleated cells were not evident under either normal or hyposalinity conditions. Shark sera were isoosmolar with the seawater or diluted seawater, with serum chemistries of the hyposalinity group reflecting the 23% reduction in environmental minerals and electrolytes, compared to sharks in normal seawater. In marked contrast, bass adapted to diluted seawater resorbed bone particles and maintained normal serum chemistries. Electron microcopy showed that the bone particles were surrounded by large, foamy multinucleated cells, many with membrane specializations typical of osteoclasts from higher vertebrates, i.e., extensive clear zones apposed to intact bone matrix and active ruffled borders overlying areas of matrix undergoing dissolution. Although osteoclasts had not been described in these fish, this study shows that bass have stem cells that can be stimulated to differentiate into bone-resorbing osteoclasts.

Effect of 17beta-hydroxysteroid dehydrogenase type 2 inhibitor on bone strength in ovariectomized cynomolgus monkeys

In both sexes, a reduction in sex steroid production with aging impairs the musculoskeletal system. The goal of our study was to test the ability of WH-9062, a novel non-steroidal small molecule inhibitor of the 17beta-Hydroxysteroid Dehydrogenase type 2 enzyme, to maintain or improve bone strength without raising serum levels of testosterone or estradiol. Mature, female cynomolgus monkeys with sealed growth plates were allocated into six groups: Sham controls, OVX controls, OVX+Premarin (15 mg/kg/d), and three groups of OVX monkeys receiving WH-9062 at 1, 5 and 25 mg/kg/day. All treatments were administered by daily oral dosing for 23 weeks. Changes in lipid profile caused by OVX were corrected with WH-9062 and included lowering total of cholesterol and non-HDL cholesterol, and maintenance of initial plasma levels of HDL cholesterol. Only the highest dose of WH-9062 lowered bone resorption relative to OVX controls. Elevated bone specific alkaline phosphatase, osteocalcin, BMC and dynamic bone histomorphometry data resulted in desirable bone balance and bone strength. The obtained results support our theory that inhibition of 17beta-HSD type 2 resulted in high local estrogen and/or testosterone levels leading to maintenance of bone formation and bone strength. Collectively, our data demonstrated that the treatment paradigm that utilizes tissue selectivity and receptor bioavailability in conversion of inactive hormones to active forms could be achieved and could result in desirable effects on target tissues such as bone and muscles.

Shortage of chemical fuel as a cause of fatigue: studies by nuclear magnetic resonance and bicycle ergometry

The technique of nuclear magnetic resonance (n.m.r.) is briefly described to illustrate its use for estimating metabolite levels in vivo. Our studies of fatigue in anaerobic frog muscle at 4 degree C are described in relation to (a) force development, (b) speed of relaxation and (c) the switching on and off of glycolysis. Both (a) and (b) are closely related, though in different ways, to the concentrations of key metabolites. In contrast, (c) is not related to metabolite levels as such but to the events of contraction and relaxation. A special n.m.r. technique (saturation transfer) has been used to study the creatine kinase system in vivo. The results show that this system is highly active and is in equilibrium in resting muscle. The free [ADP] is consequently only a small fraction of that found by analysis of muscle extracts. Studies of human power production as a function of duration of exercise also indicate that it is shortage of chemical fuel that brings short- and medium-term exercise (0.1-10 min) to a halt. It is proposed to extend n.m.r. methods to human subjects in the near future. A working hypothesis to account for fatigue is suggested in which both the contractile system and the activating system play a part.

Antitumor activity of sorafenib in FLT3-driven leukemic cells

Activating internal tandem duplication (ITD) insertions in the juxtamembrane domain of the FLT3 tyrosine kinase are found in about one fourth of patients with acute myeloid leukemia and have been shown to be an independent negative prognostic factor for survival. We show that sorafenib (BAY 43-9006, Nexavar) potently inhibits FLT3 enzymatic and signaling activities. In HEK293 cells stably transfected with FLT3-WT or FLT3-ITD, sorafenib blocked basal and ligand dependent FLT3-mediated tyrosine autophosphorylation as well as extracellular signal-regulated kinase1/2 and Stat5 phosphorylation. In leukemia cell lines MV4-11 and EOL-1, sorafenib treatment resulted in decreased cell proliferation and inhibition of FLT3 signaling. The growth of the FLT3-independent RS4-11 cell line was only weakly inhibited by sorafenib. Cell cycle arrest and induction of apoptosis were observed upon treatment with sorafenib in MV4-11 and EOL-1 cells. The antitumor efficacy of sorafenib was evaluated against the MV4-11 leukemia grown subcutaneously in NCr nu/nu mice. Doses of 3 and 10 mg/kg administered orally for 14 days resulted in six and nine out of 10 animals with complete responses, respectively. The demonstration that sorafenib exhibits potent target inhibition and efficacy in FLT3-driven models suggests that this compound may have a therapeutic benefit for patients with FLT3-driven leukemias.

Chlorimipramine: A novel anticancer agent with a mitochondrial target

Mitochondria have been suggested to be a potential intracellular target for cancer chemotherapy. In this report, we demonstrate the ability of the tricyclic antidepressant chlorimipramine to kill human glioma cells in vitro by a molecular mechanism resulting in an increase in caspase 3 activity following inhibition of glioma oxygen consumption. Studies with isolated rat mitochondria showed that chlorimipramine specifically inhibited mitochondrial complex III activity, which causes decreased mitochondrial membrane potential as well as mitochondrial swelling and vacuolation. The use of chlorimipramine in human as an effective, non-toxic cancer therapeutic having a strong selectivity between cancer cells and normal cells on the basis of their mitochondrial function is discussed.

Translabial sonography of vaginal fibroids: report of 2 cases and review of the literature

OBJECTIVE

To determine the role of translabial sonography in the diagnosis of vaginal fibroids.

METHODS

Two women with vaginal masses of undetermined origin were examined by various imaging procedures, including translabial sonography.

RESULTS

Initial examinations, which included transabdominal sonography, cystoscopy, and cystourethrography, yielded inconclusive findings. Translabial sonography, however, suggested isolated vaginal leiomyomas in both patients, and in both the diagnosis was confirmed histologically after surgery.

CONCLUSIONS

Translabial sonography should be considered as an adjunct to transabdominal and transvaginal sonography for patients with suspected vaginal fibroids.

High-pressure replica technique for in vitro imaging of pore morphologies in teeth

The presence of a natural pore morphology is an essential factor in chemical and mechanical stability of teeth. Common histological methods give only an insufficient picture of the three-dimensional pore distribution in sound or carious teeth. This paper describes a new technique to obtain complete images of the pore structure in teeth or other biological hard tissues. Whole extracted human teeth from orthodontic therapy are mechanically cleaned and organic remnants removed chemically. After being (partly) dried, the teeth are penetrated by a freshly prepared and colored (rhodamine B dye) two-component epoxy resin. The resin is pressed into the pores and cavities of the teeth with pressures of up to 2000 bar in a high-pressure vessel by means of a manually driven piston screw pump for pressure generation. The resin fills all hollow spaces of the tooth down to sizes below 0.1 micron. The pulp and the root canals are cast in massive forms of the hardened epoxy resin, giving an exact replica of the natural structure. The penetrated samples in the form of whole, intact teeth are investigated microscopically so that the pore morphology of the tooth surface, including carious defects, can be examined. The structure of the pores extending into the interior of the tooth can be made visible by dissolution of the hard tissue--for example, in acid solutions. Micro-cavities filled with the resin are observed in thin, ground, and polished cross- and longitudinal sections cut from the teeth. The colored resin induces a high contrast to the dental apatite material. In fluorescence microscopy, only the resin structures are visible.

Morphological and structural characteristics of the proximal femur in human and rat

Because the ovariectomized rat model of postmenopausal osteoporosis is the most commonly used small animal model to investigate consequences of bone loss on bone structure and strength, or to assess benefits of the various therapeutic strategies to improve bone mass and strength, the attempt was made to compare histoanatomical and structural characteristics of the femoral neck between human and rat models. In addition to different biomechanics, there is a significant difference in gross- and microanatomy of the proximal femur between humans and rats. Percent of the cortical bone component is much higher in rats (72.5%) relative to humans (12.5%). Also, cortical bone at the femoral neck in rats is evenly distributed, whereas in humans there is a considerable difference in the amount of the cortical bone between the superior half of the femoral neck with cortical thickness being only 0.3 mm, and the inferior half of the neck having 6-mm-thick cortex. Humans have far more cancellous bone at the femoral neck (22.7% average) relative to rats (6.8%). In addition, cancellous bone at the femoral neck in humans is unevenly distributed between the bone center and its periphery. Human samples exhibited striking differences in the cancellous bone structure between weight-bearing and tensile trabecular groups exhibiting clear trabecular orientation consisting of plates and rods, and trabeculae around the neutral bone axis with little mechanical activity exhibiting rod-like trabeculae only. Although humans and rats have a periosteum covering the femoral neck, and each lacks the muscular attachment at intracapsular portions of the femoral neck, rats, in contrast to humans, have the ability to quickly adapt cortical thickness and increase inertia to meet mechanical needs via modeling-dependent periosteal apposition.

Mutuality and solidarity: assessing risks and sharing losses

Mutuality is the principle of private, commercial insurance; individuals enter the pool for sharing losses, and pay according to the best estimate of the risk they bring with them. Solidarity is the sharing of losses with payment according to some other scheme; this is the principle of state social insurance; essential features of solidarity are comprehensiveness and compulsion. Private insurance is subject to the uberrima fides principle, or utmost good faith; each side declares all it knows about the risk. The Disability Discrimination Act requires insurers to justify disability discrimination on the basis of relevant information, acturial, statistical or medical, on which it is reasonable to rely. It could be very damaging to private insurance to abandon uberrima fides. However, although some genetic information is clearly useful to underwriters, other information may be so general as to be of little use. The way in which mortality rates are assessed is also explained.

Mitochondrial activity and cytotoxicity of vitamin A (retinol) in yeast and human cell cultures. Protective effect of antioxidants

Vitamin A inhibited the growth of yeast and human cells in a dose-dependent but selective manner in cultures utilizing a non-fermentable carbon and energy source. At sub-inhibitory concentrations in yeast cultures (approximately 100 micrograms/mL), the vitamin had a stimulatory effect on the mitochondrial system, foreshortening the lag phase in the adaptation to non-fermentable substrate. At inhibitory concentrations, vitamin A depressed mitochondrial protein synthesis relative to cytoplasmic protein synthesis and induced the mitochondrial mutation petite but had little or no mutagenicity with respect to nuclear genes at the concentrations used. The vitamin showed a dose-dependent cytotoxicity (lethality) in both yeast and human cells. All of these deleterious effects were overcome to a large extent by the presence of antioxidants implicating free-radical metabolites in much of the toxicity.

Assessment of clinical significance of anti-Ge in an untransfused man

A 19-year-old, untransfused Melanesian man from Papua New Guinea was admitted to the hospital for repair of an atrial septal defect. His serum contained an alloantibody that reacted strongly on the indirect antiglobulin test and was identified as anti-Ge. Gerbich-negative blood was transfused following urgent surgery. A 51Cr red cell survival study performed 2 weeks after surgery yielded zero survival of Gerbich-positive cells after 24 hours. A monocyte-driven, antibody-dependent, cell-mediated cytotoxicity assay performed on both pretransfusion and posttransfusion serum samples and on concentrated serum showed less than 1 percent specific lysis of Gerbich-positive cells. This did not correlate with the indication of clinical significance predicted by the 51Cr study. Red cell adherence and phagocytosis, not evident in a monocyte monolayer assay using native serum, were demonstrable in 16 percent of monocytes by the use of concentrated serum.

Effect of antioxidants on the mitochondrial activity and toxicity of the cancer drug methylglyoxal bis (guanylhydrazone) in yeast and mammalian cells

Mitochondria of yeast cells were primary targets of methylglyoxal bis (guanylhydrazone) (MGBG) from the following criteria: (1) selective inhibition of growth of cells utilizing a non-fermentable energy source, (2) inhibition of mitochondrial protein synthesis compared with cytosolic protein synthesis and (3) selective mutagenesis of the mitochondrial genome compared with nuclear mutagenesis. Evidence of primary antimitochondrial activity of MGBG in mammalian cells was provided by greater potency of the drug in guinea pig keratinocyte cultures utilizing glutamine as carbon and energy source compared with fermentable glucose. Cell death was used as a measure of drug toxicity in both yeast and mammalian systems. The antioxidants glutathione, vitamin E and vitamin C reversed toxicity and antimitochondrial activity to a large extent implying that toxic free radical metabolites of the drug are of significance in cellular activity of MGBG.

Cancer pain intensity measurement: concurrent validity of three tools--finger dynamometer, pain intensity number scale, visual analogue scale

Although the visual analogue scale (VAS) and number scales are known to be valid and sensitive measures of pain intensity, some older individuals are unable to use them. For individuals who lack the ability to use these scales, valid alternative measures of pain intensity would be useful for research and clinical practice. The purpose of this study was to examine the concurrent validity of a new measure of pain intensity, the Finger Dynamometer (FD), in a sample of 15 adults with advanced stage cancer pain. In a repeated measures correlational design each patient rated present pain intensity using the FD, a Pain Intensity Number Scale (PINS), and a VAS at four separate times. Data analyses using Kendall Correlational Coefficients indicated weak to moderate correlation between the FD and PINS (gamma = .47 to .68; p less than .01) and between the FD and VAS (gamma = .38 to .46; p less than .05) at each measurement time. Strong correlation was found between the VAS and the PINS (gamma = .77 to .89; p less than .001). Findings support the concurrent validity of the VAS and the PINS but indicate that further research is necessary to establish the psychometric properties of the FD as a measure of pain intensity in chronic pain models, such as cancer pain. Recommendations are made regarding important variables to be considered in further research with the FD.

Primary mitochondrial activity of gossypol in yeast and mammalian cells

Gossypol showed primary antimitochondrial activity in yeast cells in that the drug (1) inhibited growth of cells utilizing mitochondrial substrates as carbon and energy sources, and (2) selectively inhibited mitochondrial protein synthesis. Primary antimitochondrial activity was demonstrated in guinea-pig keratinocytes (GPK) by early arrest of growth and loss of viability in medium with glutamine (a mitochondrial substrate) as carbon and energy source compared with cells utilizing glucose. Gossypol depressed oxygen uptake directly in respiring cells. Gossypol interacted with the known antimitochondrial agents ethidium bromide and 5-fluorouracil (FU), potentiating the activity of FU but reversing that of ethidium bromide in yeast and GPK. Also, the activity of the mitochondrial inhibitor oligomycin was reversed by the presence of gossypol in yeast cells but not tested in GPK. The uptake and retention of the mitochondria-specific dye rhodamine 123 were much depressed by gossypol in GPK. Gossypol showed little or no inhibitory effects in yeast or GPK in the presence of ethanol (0.2-0.5%). The drug was not mutagenic with respect to the yeast mitochondrial system. It was tentatively suggested that mitochondrial perturbation could explain the antifertility effect of gossypol if it is assumed that mitochondria have a special role to play in spermatogenesis and sperm motility, making these tissues more sensitive to mitochondrial inhibitors than somatic cells.

Expression of the primary biliary cirrhosis antigens in yeast: aspects of mitochondrial control

The mitochondria of 21 yeast strains were tested for the expression of primary biliary cirrhosis (PBC) specific antigens. The amounts of the antigens in the mitochondrial preparations varied with the strains. Genetic analysis of the strain differences in antigen expression indicated nuclear control which was complex. Those strains expressing the least amounts of antigens exhibited coagulating mitochondria in organellar preparations. Additional evidence relating expression of antigens to the physiological/structural state of mitochondria was that cells grown in the presence of the mitochondrial uncoupling agent, 2,4-dinitrophenol (DNP), failed to produce any antigens, and that glucose repression of mitochondria suppressed antigen expression. Blockage of mitochondrial protein synthesis either through petite mutation or by culture in the presence of erythromycin decreased the content of antigens in the mitochondria but did not completely block antigen production. The presence of the PBC antigen in the mitochondria of these cells with nonfunctional mitochondrial synthesizing machinery further indicates that these antigens are cytoplasmically synthesized. Analysis of the pre- and postmitochondrial fractions of all homogenates confirmed that the antigens are not only cytoplasmically synthesized but also have an extramitochondrial location in cells, probably in the plasma membrane.

A solid-phase antiglobulin test

A solid-phase test (SPT), a machine-readable adaptation of the indirect anti-human globulin test (IAHG), is described. The SPT level of sensitivity was comparable to that of the manual IAHG test for the detection of IgG antibodies and was compared with manual pretransfusion compatibility tests. The average difference from the mean of duplicate SPT results was 5.94 percent of the optical density value. The data also demonstrated a linear and overlapping relationship between the scores of manual IAHG tests and SPT optical density values. The accuracy of the SPT declined slightly as the concentration of red cell samples increased; the optimum concentration of immunoglobulin used in the preparation of the solid phase was about 275 mg per l. The 97.5th percentile of negative tests occurred at the same optical density (0.13) when serums from either healthy donors or hospitalized patients were tested. Compatibility tests completed on 1304 blood samples from donors and 437 serum samples from hospitalized patients showed that 1.38 percent of results were SPT-positive and manual IAHG-negative, and 5.37 percent were SPT-negative and manual IAHG-positive. The lowest possible score in the manual test was allocated to 97.14 percent of the latter group, indicating good correlation between the two techniques.

Enrichment of collagen and gelatin degrading activities in the plasma membranes of human cancer cells

Interactions between connective tissue substrates and proteinases localized to the surface of cancer cells are implicated in cancer invasion. In this report we have compared the enrichment of collagen and gelatin degrading activities and cysteine proteinase(s) in well-characterized (enzyme markers and electron microscopy) subcellular membrane fractions isolated from human small cell lung cancer lines (NCI-H69 and NCI-H82) and the RWP-1 pancreatic cancer line. With each cell line collagenolytic, gelatinolytic, and cysteine proteinase activities were enriched 5- to 128-fold in the plasma membrane fractions with differences noted between microvilli versus smooth membrane profiles. Incubation of tumor plasma membranes with methyl-3H-labeled collagen resulted in extensive degradation of the gamma, beta, alpha 1, and alpha 2 chains, suggesting the combined action of metalloproteinases. Treatment of tumor plasma membranes with the chaotropic agent, 2 M KCl, did not diminish membrane collagen- or gelatin-degrading activity, but extensively leached out the cysteine proteinase, suggesting that the latter enzyme is not an integral membrane protein. Enzyme inhibitors specific for metalloproteinases and cysteine proteinase were used to corroborate enzymatic classification. In conclusion, we have demonstrated variations in the localization of proteinases in the plasma membrane domains of different human cancer cells.

Effects of haloperidol and d-amphetamine on perceived quantity of food and tones

The hypothesis that dopamine (DA) receptor agonists and antagonists affect "hedonia" associated with natural rewards was tested, using a psychophysical procedure previously shown to be sensitive to both the sweetness of food and the motivational state of rats. Rats were first trained to discriminate between two different quantities of a rewarding stimulus by pressing one of two levers. Perceived quantity was subsequently derived from generalization trials of intermediate quantities. Haloperidol (0.03-0.083 mg/kg), a DA receptor antagonist, did not influence perceived food quantity, an indirect marker of hedonic value. On the other hand, d-amphetamine (0.25-1.0 mg/kg) affected perceived food quantity in a dose-dependent fashion, and in the same direction as occurs after increasing hunger or food sweetness. Both haloperidol and amphetamine influenced the perceived quantity of a stimulus without natural reinforcing properties (a tone), but the effect of amphetamine on the perceived quantity of this initially neutral stimulus was opposite in direction to that observed with food. These results suggest that whereas amphetamine affects hedonic processes, haloperidol does not. In addition, it seems that haloperidol probably produces its actions through effects on motor mechanisms or by interfering with the response-facilitating properties of rewards.

Purification of a hemolytic factor from ras oncogene transformed fibroblasts

Transformation of NIH-3T3 fibroblasts by the Harvey murine sarcoma viral oncogene or by cultivation of fibroblasts under low serum conditions (spontaneous) resulted in the acquisition of hemolytic activity, as demonstrated by coincubation of the transformed fibroblasts with 59Fe-labeled red blood cells. The tumor Hemolytic Factor was partially purified from conditioned media produced by T-24 human bladder transformed fibroblasts by ammonium sulfate precipitation, followed by anion and gel filtration chromatography. The hemolytic factor has a molecular weight of 66,000 as documented by SDS-PAGE and is destroyed by heating to 60 degrees C.

Continuous infusion of spinally administered narcotics for the relief of pain due to malignant disorders

The INFUSAID model #400 totally implantable drug delivery system was implanted in 17 patients for the continuous infusion of spinally administered preservative-free morphine sulfate. Sixteen patients had pain of malignant origin, and one patient had pain secondary to meningomyelocele. Over time, there was a consistent mean improvement in analgesia scores ranging from 50% to 70% of the control levels for 16 of the patients with cancer-related pain. This form of pain therapy was not successful in treating the benign pain of the patient with meningomyelocele. Overall, the patients with cancer were pleased with their pain therapy, experienced few complications, and reported improved quality of life. Continuous infusion of spinally administered narcotics using a totally implantable drug delivery system such as the INFUSAID model #400 is a safe, complication-free procedure for the control of cancer-related pain.

Effect of aspirin on mitochondrial mutagens in Saccharomyces cerevisiae

The mitochondrial mutation petite was induced in yeast cells by ethidium bromide (EB), Adriamycin (ADR) and 4-nitroquinoline-N-oxide (NQO). In the presence of aspirin in concentrations ranging from 0.1 to 1.0 mg/ml, the mutagenicity of EB and ADR was reversed but petite induction by NQO was unaffected. At these concentrations, aspirin also reversed mitochondrial inhibition by oligomycin, a non-mutagenic inhibitor of the organellar ATPase complex. Cells grown in the presence of aspirin alone showed a significantly higher rate of oxygen uptake than untreated control cultures when the drug concentration ranged from 0.05 to 1.0 mg/ml. At concentrations of 2 mg/ml and above, aspirin inhibited mitochondrial respiration.

Detection of primary antimitochondrial activity of drugs in cultured mammalian cells utilizing glutamine as the carbon source

Growth of guinea-pig keratocytes (GPK) proceeded normally in standard medium in which glutamine (mitochondrial substrate) replaced glucose as the carbon and energy source. Cells in the glucose-free glutamine cultures were much more sensitive to the toxic and growth-inhibiting effects of the antimitochondrial drugs ethidium bromide, chloramphenicol and oligomycin than cells in glucose-containing cultures. In the latter, cells continued to proliferate in the presence of these drugs after 2-3 days incubation, but in the non-fermenting cells growth was arrested within 24 h and there was more than 95% cell death after 2 days. Cycloheximide, a general inhibitor of protein synthesis in eukaryotic cells, showed no selective inhibition of growth and glutamine and glucose cultures were equally affected. The system appears to be useful for the detection of primary antimitochondrial activity of drugs in general.

Studies on the genetic regulation of cytochrome P-450 production in Saccharomyces cerevisiae

An initial survey of 18 haploid strains of Saccharomyces cerevisiae revealed that only 3 of these strains could produce a detectable level of cytochrome P-450. A cross between a cytochrome P-450 producing strain of S. cerevisiae (B/B) and a non-producing strain (D22) gave a diploid which was a non-producer and a 2:2 segregation of producers to non-producers in meiotic tetrads. Of the two producers in each tetrad, one produced a higher level of cytochrome P-450 than the other. We deduce that cytochrome P-450 production in S. cerevisiae is regulated by a single nuclear gene and that a modifier gene is also involved which can enhance the amount of cytochrome P-450 synthesized. Benzo(a)pyrene (an inducer of P-450 in yeast) had no effect on the action of the regulatory gene.

Mitochondrial control of cell surface characteristics in Saccharomyces cerevisiae

Defects in the inner mitochondrial membrane of petite mutants of yeast resulted not only in respiratory deficiency, but also in changes in cell surface characteristics. These were (1) concanavalin A agglutinability, (2) cell movement in a biphasic polymer system, (3) cell adhesion. Genetic analysis indicated that the control exerted by the mitochondria was on nuclear genes or on the products of these genes which were presumably specifying cell surface components. These findings ascribe a new role to mitochondria but also have implications for neoplastic transformation.

Primary antimitochondrial activity of the cancer drug methylglyoxal bis(guanylhydrazone) in yeast cells

Primary action of methylglyoxal bis(guanylhydrazone) (MGBG) on the yeast mitochondrial system was demonstrated by (1) selective inhibition of cell growth in non-fermentable medium, (2) blockage of mitochondrial synthesis of cytochromes aa3 and b and (3) ultrastructural aberration. The drug caused extensive deletions in mitochondrial DNA detected by an increase in the frequency of the mitochondrial mutant petite but had little or no effect on cell viability. Growth inhibition by MGBG had any effect on growth inhibition by ethidium bromide. Strains showed no cross-correlation in their tolerance to MGBG and ethidium bromide.