Potassium, sodium, and cancer: a review

Agents known or believed to be carcinogenic decrease the concentration of potassium and increase the concentration of sodium in the cells. Anticarcinogenic agents have the opposite effect. In all cases where we have information on an agent's carcinogenicity or anticarcinogenicity and on that agent's effects on cellular potassium and sodium concentrations the above relationships have been found to be true. Dietary carcinogenic agents studied include sodium, cadmium, fat, cholesterol, calories, and alcohol; dietary anticarcinogenic agents include potassium, vitamins A, C, and D, selenium, and fiber. The effect of calcium intake is less clear as that effect depends on the concentrations on sodium and potassium. Not only dietary agents but also other carcinogenic and anticarcinogenic agents work in the same way. The cancer-causing drug dimethylhydrazine increases sodium and decreases potassium in the cells, whereas, for example, indomethacin, an anticarcinogen, has the opposite effect. In aging potassium leaves the cells, sodium enters them, and the rates of cancer increase. Patients with hyperkalemic diseases (Parkinson, Addison) have reduced cancer rates, and patients with hypokalemic diseases (alcoholism, obesity, stress) have increased cancer rates.     

Differences between and within genders in caregiving strain: a comparison between caregivers of demented and non-caregivers of non-demented elderly people

Fifty-two caregivers for demented and 66 non-caregivers for non-demented elderly were investigated both within a gender and between genders. All participants were relatives and a burden questionnaire was used. The results showed that there was not always a difference between the caregivers for demented and the non-caregivers for non-demented elderly which may indicate that being a relative, even to a non-demented elderly, has obviously its own problems and importance. However, results showed more significant differences between female caregivers and female non-caregivers than between male caregivers and male non-caregivers, with females caring for a demented elderly suffering most strain. Their strain was exhibited by health problems, conflicts in the family, strained relations with family and others, a less positive outlook and limits in social support because of the caregiving situation. When investigating the group of male caregivers and male non-caregivers, it was found that males caring for a demented elderly person experienced a lack of positive outlook and a need for social support. The elderly person's residence in the group of caregivers for demented elderly people and in the group of non-caregivers for non-demented elderly people did not, however, appear to indicate any significant differences.     

Reduced beta 2-microglobulin mRNA levels in transgenic mice expressing a designed hammerhead ribozyme

We have generated three artificial hammerhead ribozymes, denoted 'Rz-b', 'Rz-c' and 'Rz-d', with different specificities for exon II of the mouse beta-2-microglobulin (beta 2M) mRNA. In this study we tested for ribozyme mediated reduction of beta 2M mRNA in a cell line and in transgenic mice. Transfections of either of the Rz-b, Rz-c or Rz-d plasmids into a mouse cell-line (NIH/3T3) revealed reductions of beta 2M mRNA substrate in each case. Ribozyme expression in individual transfected clones was accompanied with an up to 80% reduction of beta 2M mRNA levels. Rz-c was selected for a transgenic study. Seven Rz-c transgenic founder animals were identified from which three ribozyme expressing families were established and analysed. Expression of the ribozyme transgene was tested for and detected in lung, kidney and spleen. Expression was accompanied with reduction of the beta 2M mRNA levels of heterozygous (Rz+/-) animals compared to non-transgenic litter mates. The effect was most pronounced in lung with more than 90% beta 2M mRNA reduction in individual mice. In summary, expression of our ribozymes in a cell free system, in a cell-line and in transgenic mice were all accompanied with reductions of beta 2M mRNA levels.     

Reduction of 2-nitropropane in an undivided,flooded, bipolar cell

As one model reaction in the study of the effect of contacting patterns on the overall specificity of electrosynthetic reactions, 2-nitropropane has been reduced to isopropylhydroxylamine and isopropylamine in an undivided, flooded, bipolar cell. Even though this cell was expected to be unfavourable for the overall reaction it was found that high space-time yields and current efficiencies could be obtained with a suitable choice of contacting pattern.     

Lectin studies of surface carbohydrates and induction of gland secretion in the free-living stages ofSchistosoma mansoni

Secretion from glands was observed when cercariae ofSchistosoma mansoni were exposed to certain lectins. Lectins fromMaclura pomifera, Pisum sativum, andTriticum vulgaris, were effective at 7.5 /ml. The effects of cercarial gland secretion caused byT. vulgaris agglutinin andArachis hypogaea agglutinin were blocked by pretreatment with the inhibiting glycan. Discharge of glands was not visualized after exposure of miracidia to lectins. The distribution of five labeled lectins was determined on live miracidia and cercariae. OnlyT. vulgaris agglutinin generally labeled the cercarial and miracidial bodies. Specific labeling occurred with the other lectins on the anterior, in glands or on their secretions, in flame cells in both stages, and on an unidentified ring of cells in miracidia. The possible mechanisms involved in changes caused by the lectins are discussed.     

Molecular fractionation in melt-crystallized polyethylene: 3. Microscopy of solvent-treated samples

Microscopy of melt-crystallized polyethylenes treated with hot p-xylene has revealed information concerning the morphology of the systems, in particular the distribution of the segregated low molecular weight material in the structure. It seems that this material, in accordance with earlier reports, is concentrated in the spherulite boundaries and between main lamellae within the spherulites. The effect of thermal treatment and the structure of the material on this morphological aspect is reported.     

Essential thrombocythemia at diagnosis: causes of diagnostic evaluation and presence of positive diagnostic findings

Antipsychotic drugs are effective in psychoses, whatever the aetiology of the disorder. The positive symptoms tend to respond more readily. The need for developing new drugs arises from the refractoriness of the negative symptoms, the 10-25% of the patients that are treatment-resistant and the problems of short-, and long-term extrapyramidal side-effects. Thus far, five drugs differing from the classical antipsychotics have been licensed for use: clozapine, olanzepine, risperidone, sertindole and sulpiride, and in at least some European countries quetiapine is now in the final phase of clinical research. This review starts with a brief introduction to symptomatology, is limited to the registered drugs and addresses differences with the classical drugs in pharmacology, pharmacokinetics, clinical aspects and side-effects. Clozapine, risperidone and sulpiride can be considered for clinical use in refractory patients, and these three together with olanzapine and sertindole are candidates when extrapyramidal side-effects cause a clinical problem.     

A rapid method of visualizing the pancreatic islets for studies of islet capillary blood flow using non-radioactive microspheres

A technique is described for visualization of the pancreatic islets in the rat by simple dark field illumination of pieces of the frozen and thawed pancreas. By using this method, microspheres, injected for studies of the capillary blood flow, can be readily located and counted in both the islets and the exocrine parenchyma. The procedure could be useful both for rapid estimations of the total number of islets and for studies of their microcirculation.     

Distribution of reaction in a cell with gas-evolving electrodes. I. Magnesium/silver chloride seawater battery

The effects of gas evolution on the distribution of reaction at high current densities have been studied experimentally in a model Mg-AgCl battery cell. Measurements of current, potential, pH and temperature were made at four vertical locations during discharge at applied pressures between 1–6 bar(g). Temperature and pressure were found to influence local current density with consequences for overall battery lifetime.     

An anomaly in the necking behavior of polyethylene,Part 2

Dumb-bell shaped specimens of three polyethylenes were subjected to constant uniaxial tensile loads at test temperatures from 298 to 353 K. For the high density polyethylenes, a marked transition appeared in the neck/fracture behavior. At a certain stress level, the instantaneous fracture of the neck formed at high loads was replaced by the formation of a neck that resisted fracture for a considerable time. This transition was more gradual for the medium density polyethylene. Furthermore, at all test temperatures the transition shifts towards higher nominal stresses with increasing molecular weight. Mainly on the basis of measurements of the local strain rate in the neck forming region, a hypothesis is proposed which explains the appearance of the marked transition. The draw ratios and the densities of the fractured neck fibers were also measured and are in accordance with current molecular deformation theories.