Suppression of PTEN expression is essential for antiapoptosis and cellular transformation by oncogenic Ras

Ras is one of the most commonly mutated oncogenes in the array of human cancers. The mechanism by which Ras induces cellular transformation is, however, not fully elucidated. We present here evidence that oncogenic Ras suppresses the expression of the tumor suppressor phosphatase and tensin homologue deleted from chromosome 10 (PTEN), and this action of oncogenic Ras is mediated by the Raf-mitogen-activated protein kinase/extracellular signal-regulated kinase (ERK) kinase (MEK)-ERK pathway via up-regulation of c-Jun. Jun(+/+) cells undergo cellular transformation by oncogenic Ras, and restoration of wild-type PTEN, but not a phosphate-defective mutant of PTEN, induces apoptosis in these cells. Conversely, in Jun(-/-) cells, oncogenic Ras neither suppresses PTEN nor causes transformation, but rather it induces PTEN-dependent apoptosis. An apoptotic response to oncogenic Ras in Jun(-/-) cells can be prevented by suppressing PTEN expression. These findings imply that oncogenic Ras suppresses the apoptotic gene PTEN via the Raf-MEK-ERK-c-Jun pathway to induce antiapoptosis and cellular transformation. Together, our findings identify a novel molecular interface between the oncogenic and tumor suppressor pathways that regulates cellular transformation and survival.     

Potential biosoluble carriers: biocompatibility and biodegradability of oxidized cellulose

The biocompatibility and biodegradability of periodate oxidized cellulose is assessed in vivo. Morophological and histopathological studies over a period of six months indicate that oxidized cellulose degrades slowly without producing excessive tissue reaction. Preliminary investigations on the kinetics of degradation of oxidized cellulose in vitro, immobilization of alpha-chymotrypsin on it and the rate of the enzyme release in a solution of pH 7.4 are also briefly reported.     

Identity disturbances in drug addicts

Identity disturbances in a heterogeneous group of drug addicts (n = 30) were studied. Hirvas' scale of identity, which is based on Erikson's epigenetic theory of personality development was used. An equal number of normal individuals formed the control group. The identity confusion was studied in three dimensions: intrapersonal, interpersonal, and capacity for objective self-appraisal. Among the addicts a significantly high degree of identity disturbances was found in these three dimensions regarding areas of time perspective, sexual identity, leadership polarisation and ideological polarisation. The possible interrelationship between these disturbances and addictive behaviour is discussed.     

Thermally stimulated depolarization currents in thiourea-formaldehyde polycondensate

A thiourea-formaldehyde polycondensate was synthesized in acidic medium using glacial acetic acid. It was characterized by elemental analysis, infrared spectroscopy and thermal techniques. The thermally stimulated depolarization (TSD) current characteristics were studied under different polarization and depolarization conditions. The TSD results indicate a transition at 126°C. Depolarization kinetics data of the thermoelectret are reported. The polarization and depolarization phenomena were correlated with physical as well as chemical changes occurring in the material.     

Chronic pain therapy with transcutaneous electrical nerve stimulation: predictive value of questionnaires

A retrospective study of 200 chronic pain patients was conducted to determine whether preexisting physical or social factors influence treatment success with transcutaneous electrical nerve stimulation (TENS). Responses to 30 questions from a preadmission questionnaire were analyzed against short-term treatment success. Patients with pain of more than a year's duration, who had undergone multiple surgical operations for pain control, who used tranquilizers, or who were not working because of pain, demonstrated a generally lower rate of treatment success, although the differences were not statistically significant. Treatment success rate was significantly higher for retired patients than for those with blue-collar jobs or those who were unemployed. There was no association between treatment success rate and site, frequency, character or severity of pain, age, sex, use of narcotic analgesics, or the presence of financial compensation or litigation. The value of TENS for chronic pain remains largely empirical.     

Etiological agents of acute poliomyelitis in South India

This study was done to identify the specific etiological agents that cause acute poliomyelitis (APM). All the children newly diagnosed clinically as APM at the Institute of Child Health, Madras, during the period May 1988 to May 1989 were recruited. Stool specimen collection, transportation and identification of viruses by culture were done by standard procedures. The total number of children recruited was 312. Specimens were contaminated/insufficient in 10. Analysis was done for 302 cases. Polio virus type II was identified in 25.5% children, type I in 18.5%, type III in 15.9%, multiple polioviruses in 6.3% and non-polio enteroviruses (NPEV) in 20.2% cases. No virus was identified in 13.6%. Among the APM cases clinically diagnosed, the proportion of NPEV has increased considerably from 5% in 1984 to 20.2% in 1988–89. The age distribution was not significantly different between polio viruses and NPEV. The distribution of polio viruses and NPEV did not differ significantly in relation to immunization status, source of water supply, method of excreta disposal and the clinical types. For surveillance and control/eradication program of poliomyelitis, laboratory confirmation is essential.     

The course and outcome of drug addiction. A follow-up study of 178 cases in Madurai,South India

One hundred and seventy-eight subjects diagnosed as dependent on various agents and first seen between 1970 and 1974 were followed up for 6–10 years and data collected in respect of the persistence of drug-taking behaviour, marital and occupational adjustment and mortality. Data were obtained in 173 cases. Drug-taking persisted continuously in 87 and intermittently in 11 subjects and abstinence was achieved in 40 cases. The majority showed maladjustment in occupation and marital relations. There was a mortality of 17% (29 deaths) including 16 suicides. Twenty-eight (17%) had made suicidal attempts. The observations are discussed from some Indian cultural points of view with reference to the follow-up characteristics of different types of addiction.     

Synthesis and electrical properties of monomeric and polymeric iron-phthalocyanines

A set of experimental conditions are described for the synthesis of monomeric and polymeric iron-phthalocyanines and compared with those reported in the literature. The dielectric constant and resistivity of characterised samples are studied as a function of temperature. The data indicate possible transitions at 90 and 180°C for monomeric iron-phthalocyanine whereas polymeric iron-phthalocyanine shows no breaks.     

Polymerisation of 1,3,5-trioxane in presence of maleic anhydride, 2. An example of cationic living polymerisation

Evidence is presented for the possible existence of ‘living’ ends in the cationic polymerisation using ZnCl₂, BF₃ · OEt₂, and γ-rays as initiators of 1,3,5-trioxane to polyoxymethylene in presence of maleic anhydride (1 : 1 by mole), where this binary system exists as a melt.