Telomerase activity and telomere lengths in various cell lines: changes of telomerase activity can be another method for chemosensitivity evaluation

For the cancer cells which have overcome the second mitotic clock (M2), activated telomerase is essential and used as another marker of immortality. Many trials had been initiated to target telomerase, which is known to be specific to tumors. To determine the best in vitro cell system for testing the efficacy of telomerase inhibitors, we evaluated the telomerase activity of various cancer cell lines and measured their telomere lengths. We also treated some cancer cell lines with adriamycin and measured the changes of telomerase activity. Telomerase activity was evaluated in various cell lines with the TRAP (telomeric repeat amplification protocol) assay. Telomerase activity was calculated and translated into arbitrary units by computer-assisted densitometry with the control of telomerase activity in the 293 control cell line. Also, terminal restriction fragment lengths were measured using Southern blotting. We also measured telomerase activity and telomere lengths in 11 benign breast tumor tissues and 19 paired stomach cancer and normal tissues. Cancer cell lines treated with adriamycin we evaluated for changes of telomerase activity and the cell proliferation by MTT assay and dye exclusion test. Telomerase activity of cell lines was 95.3 24.1 unit with a range of 27.6-129.6 unit, while the telomere lengths of those cell lines were variable from 5.0 to 10.4 kbp with a median of 6 kbp. In 11 cancer cell lines which were not yet firmly established, we could not detect any telomerase activity. Low telomerase activity was detected in only 2 benign tumor tissues of breast with a median telomere length of 8.8 (7-10.5) kbp. Among paired 19 gastric cancer and normal tissues, only 7 cancer tissues showed weak telomerase activity. After adriamycin treatment, telomerase activity in YCC-S-1, YCC-S-3, MCF-7 and MCF-7/ADR was decreased in accordance with the changes of the cell numbers. Telomerase is specific to cancer tissues and is expressed differently from organ to organ. Telomerase activity by TRAP assay could be used as a chemosensitivity assay.     

Psychological comorbidity in patients with alarming chest pain symptoms]

About 1/3 of patients with chest pain undergoing coronary arteriography (CA) have no coronary artery disease (CAD). Individuals with non-CAD chest pain may be younger and more likely to be female; they may express higher degrees of neuroticism. Are those features stable enough to justifi; exclusion from CA if present? To investigate this issue, data on psychodiagnostic parameters (depression, anxiety, somatic complaints) were obtained in patients before this were referred to CA. Inclusion criteria were a chief complaint of chest pain with episodes of angina-like pain at rest, suspicious enough to warrant cardiac catherisation; and no prior history of CAD or other organic heart disease. The sample consisted of 77 patients, recruited from 89 eligible patients. 12 patients were excluded because CA findings were missing for multiple reasons. CA was conducted by Judkins technique. Patients were labeled as CAD (-) if no stenosis were detectable. In 50 (65%) of cases CA findings were positive and in 27 (35%) findings were negative. CAD+ were significantly older (p < 0.05); the superiority in both groups were male. Prevalence of emotional disorders was markedly more pronounced in both groups in comparison to the normal population and to a group of male myocardial infarction survivors. However, those features did not discriminate between the groups. Long acting chest pain was predictive for high degrees of emotional disability (relative risk 5.33; 95% Kl 1.6-61.6; p < 0.012). Chest pain at rest is a major source of anxiety, depression and subsequent somatic preoccupation despite its ischaemic or functional origin. It leads to clinically relevant adjustment disorders in a significant proportion of chest pain patients and triggers emotional disstress. These factors may thus have less impact on risk stratification than expected.     

Gait function in spastic hemiparetic patients walking barefoot, with firm shoes, and with ankle-foot orthosis

Cortical spreading depression is a wave of electrical and biochemical changes that spreads across the cerebral cortex. It has been hypothesized to be an important underlying cause of the visual disturbances occurring during the migraine aura, but this is difficult to test in animals or humans. We created a computational model of cortical spreading depression and found that during the wave of biochemical changes the spatial pattern of neural activity broke up into irregular patterns of lines and small patches of highly activated elements. The corresponding visual disturbances that would be produced by these patterns of neural activity resemble the hallucinations reported during the migraine aura, providing strong support for the cortical spreading depression hypothesis of migraine. The model also makes the testable prediction that these hallucinations move at an exponentially increasing speed across the visual field.     

Spinal amino acid release and precipitated withdrawal in rats chronically infused with spinal morphine

Glutamate receptors are implicated in the genesis of opioid tolerance and dependence. Factors governing release of amino acids in systems chronically exposed to opiates, however, remain undefined. Using rats, each prepared with a spinal loop dialysis catheter and with a chronic lumbar intrathecal infusion catheter connected to a subcutaneous minipump, the release of amino acids before and during antagonist-precipitated withdrawal in unanesthetized rats was examined. Spinal infusion of morphine (20 nmol/micro l/hr) for 4 d had little effect on resting release of amino acids. In morphine-infused, but not saline-infused, rats naloxone (2 mg/kg, i.p.) evoked an immediate increase in the release of L-glutamate (299 +/- 143%) and taurine (306 +/- 113%) but not other amino acids. The magnitude and time course of the release of these amino acids significantly correlated with behavioral indices of withdrawal intensity. Acute intrathecal pretreatment immediately before naloxone with clonidine (20 microg; alpha2 agonist), MK-801 (3 microg; noncompetitive NMDA antagonist), or aminophosphonopentanoic acid (AP-5; 3 microg; competitive NMDA antagonist) suppressed naloxone-induced increases in spinal L-glutamate and taurine release and behavioral signs of withdrawal in spinal morphine-infused rats. Results point to a correlated increase in spinal L-glutamate release, which contributes to genesis of the opioid withdrawal syndrome. Agents such as clonidine that suppress opioid withdrawal may owe their action to an inhibition of excitatory amino acid release. The effects of MK-801 and AP-5 suggest a glutamate-evoked glutamate release.     

The implantable cardioverter/defibrillator

Despite all advances in the diagnosis and therapy of cardiovascular diseases, the mortality from malignant ventricular tachyarrhythmias is still a major health problem. In addition to established therapeutic strategies in the prevention of sudden cardiac death such as antiarrhythmic drug treatment, catheter ablation or antiarrhythmic drug treatment, cardioverter/defibrillator was introduced to clinical practice in 1980. The number of 50,000 overall implants reflects the current clinical status of the therapy with implantable cardioverter/defibrillators. Significant technical improvements in the defibrillator therapy may contribute to an increase in therapy acceptance. These advances include the introduction of nonthoracotomy lead systems, enhanced defibrillation efficacy, full programmable devices providing tiered electrical therapy, improved diagnostic Holter functions and enhanced arrhythmia detection algorithms. The major present goals of defibrillator therapy are detection and termination of malignant ventricular tachyarrhythmias, prevention of sudden cardiac death, reduction in patient's mortality and improvement in quality of life. The efficacy and safety of defibrillator therapy to prevent sudden arrhythmic death has been proven in several large clinical investigations In patients with this device the annual sudden cardiac death mortality is < 2% even in high-risk patient populations. Compared to sudden cardiac death rate there is a much higher rate of overall cardiac mortality because a defibrillator is not able to prevent nonarrhythmic cardiovascular deaths. There is a clinical impression that cardiovascular mortality is lower in patients treated with an implantable cardioverter/defibrillator compared to patients treated with other therapies. However, there are no results from controlled studies providing scientific evidence that defribillator therapy can decrease overall cardiovascular mortality.(ABSTRACT TRUNCATED AT 250 WORDS)     

CDK4 down-regulation induced by paclitaxel is associated with G1 arrest in gastric cancer cells

Paclitaxel induces a cell cycle block at G2-M phase by preventing the depolymerization of microtubules and induces p53-independent apoptosis in many cancer cells. We observed that gastric cancer cells treated with paclitaxel have shown a cyclin-dependent kinase (CDK)4 down-regulation. This paclitaxel-induced CDK4 down-regulation resulted in a cell cycle arrest at G1-S phase. To confirm this observation, we prepared stable transfectants that overexpressed CDK4 and analyzed the cell cycle progression. Ectopic expression of CDK4 in SNU cells resulted in a release of paclitaxel-induced G1 arrest. The release of G1 arrest by enforced expression of CDK4 seems to make the cells more sensitive to paclitaxel-induced apoptosis. From this finding, we could then suggest that paclitaxel treatment induces both G1-S and G2-M blocks in the cell cycle progression of gastric cancer cells.     

Synthesis and antiplatelet, antiinflammatory, and antiallergic activities of substituted 3-chloro-5,8-dimethoxy-1,4-naphthoquinone and related compounds

2-Amino (6), 2-alkylamino (7-8), 2-methoxy (9), 2-acetamido (10), and 5,8-diacetoxy (11) derivatives of the lead compound 2,3-dichloro-5,8-dimethoxy-1,4-naphthoquinone (4) were synthesized, together with 6,7-dichloro-5,8dimethoxy-1,4-naphthoquinone (5), a positional isomer of 4. Antiplatelet, antiinflammatory, and antiallergic activities were evaluated, and most compounds were quite potent in all assays. Compounds 5 and 9-11 were especially active; however, 5 was ineffective against neutrophil superoxide formation, and 10 was ineffective against mast cell degranulation.