p53 status and prognosis in stage I-IIIa non-small cell lung cancer

To investigate the role of p53 abnormalities in predicting the survival of patients with non-small cell lung cancer (NSCLC), polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) and immunohistochemical analyses were performed on 74 and 67 tumor samples, respectively, from patients with pathological stage I-IIIa NSCLC. An abnormally migrating SSCP band was observed in 21 of 74 (28%) tumor specimens. DNA sequence analysis revealed 23 intragenic mutations including 3 small deletions and 20 point mutations. Immunohistochemical analysis using the DO-7 monoclonal antibody showed abnormal expression of p53 in 27 of 67 (40%) patients. The concordance rate between immunohistochemical and PCRSSCP analyses was 73% (49/67) in this study. Univariate and multivariate analyses demonstrated that abnormal expression of p53 may be associated with prolonged survival (p=0.0997 and 0.0099, respectively). In contrast, no relationship was observed between p53 mutation and overall survival (0.6968). These results suggest that p53 status and the survival outcome changes between immunohistochemical and mutational analyses in stage I-IIIa NSCLC.     

Contractile force and resting tension in the presence of halothane and increased extracellular potassium or decreased extracellular pH in isolated guinea pig atria

To gain a better understanding of the direct actions of halothane on myocardial function in ischaemia, we studied the effects of increasing extracellular potassium concentration and decreasing extracellular pH (acidosis), alone or in combination with halothane, on the contractile force and resting tension in isolated atria. Guinea pig left atria were superfused with Tyrode’s solution and stimulated at 1 Hz. Isometric contractile force and resting tension were measured using a force displacement transducer. Perfusate potassium concentrations were increased from 5.4 mmol · L⁻¹ to either 8.1 mmol · L⁻¹ or 10.8 mmol · L⁻¹ by adding KCl to the standard Tyrode’s solution, and its pH was decreased from 7.4 to either 7.0 or 6.5 by decreasing bicarbonate. In standard Tyrode’s solution (potassium 5.4 mmol · L⁻¹, pH 7.4), halothane 0.5–2% reduced contractile force in a dose-dependent manner (P < 0.05); the effective concentration of halothane for 50% inhibition of contractile force (IC₅₀) was 1.3%. Both increasing extracellular potassium and decreasing extracellular pH decreased the contractile force in a potassium-or pH-dependent fashion. The negative inotropism of halothane (1%) was not altered by increasing potassium concentrations, whereas 1% halothane caused a greater decrease in contractile force at pH 6.5 than at pH 7.4. Halothane (1%) enhanced the acidosis (pH 6.5)-induced increases in resting tension. Arrhythmias were produced in one of eight preparations during acidosis, while four of eight preparations demonstrated arrhythmias during acidosis in the presence of halothane. These data suggest that acidosis and halothane may have a synergistic interaction on the contractile force and resting tension of the atria. The increase in resting tension observed during acidosis/ halothane conditions suggests than an increase in cytosolic calcium is associated with these synergistic interactions between acidosis and halothane. Pour mieux comprendre l’action direct de l’halothane sur la fonction myocardique pendant l’ischémie, nous avons étudié les effets de l’augmentation du potassium extracellulaire et de la diminution du pH extracellulaire (acidose), seuls ou en association avec l’halothane, sur la force contractile et la tension de repos d’oreillettes isolées. Des oreillettes gauches de cobaye furent perfusées avec une solution de Tyrode et stimulées à 1 Hz. La force contractile isométrique et la tension de repos ont été mesurées avec un transducteur de force de déplacement. Les concentrations de potassium perfusées ont été augmentées de 5,4 mmol · L⁻¹ à 8,1 mmol · L⁻¹ ou à 10,8 mmol · L⁻¹ par l’ajout de KCl à la solution standard de Tyrode, et son pH abaissé de 7,4 à 7,0 ou 6,5 par baisse des bicarbonates. Avec la solution standard de Tyrode (potassium 5,4 mmol · L⁻¹, pH 7,4), l’halothane (0.5–2%) diminue la force contractile proportionnellement à la dose (P < 0,05); la concentration efficace d’halothane requise pour produire une inhibition de 50% de la force contractile (IC_5O) a été de 1,3%. L’augmentation du potassium extracellulaire et la diminution du pH extracellulaire réduisent toutes les deux la force contractile proportionnellement au potassium ou au pH. L’inotropisme négatif de l’halothane (1%) n’est pas modifié par l’augmentation de la concentration de potassium alors que l’halothane produit une diminution plus importante de la force contractile à un pH de 6,5 que de 7,4. L’halothane (1%) exagère l’augmentation de la tension de repos induite par l’acidose (pH 6,5). Des arrythmies sont apparues sur une des huit préparations pendant l’acidose en présence d’halothane. Ces données suggèrent que l’acidose et l’halothane pourraient avoir une activité synergique sur le force contractile et la tension de repos des oreillettes. L’augmentation de la tension de repos observée pendant l’acidose combinée à l’halothane suggère l’association d’une augmentation du calcium cytosolique avec des interactions synergiques entre l’acidose et l’halothane.     

Association of apolipoprotein ɛ4 allele and neuropathologic findings in patients with dementia

Apolipoprotein E (APOE) is a lipoprotein expressed in liver and brain as one of three isoforms (APOE 2, APOE 3 and APOE 4). Recent findings suggest that the presence of APOE 4 is associated with an increased risk for both familial Alzheimer's disease and late-onset Alzheimer's disease. We extended these observations by determining the frequency of APOE alleles in patients with pathologically confirmed Alzheimer's Disease (AD), Parkinson's disease (PD), diffuse Lewy Body disease (DLBD), AD with concomitant PD pathology, demented PD patients without or with concomitant AD pathology and in schizophrenics with a progressive dementia (SCHIZ+DEM). The APOE genotype was determined by restriction digestion of polymerase chain reaction-amplified DNA isolated from frozen brain samples. The frequency of the APOE 4 allele was highest among sporadic AD and DLBD patients (0.30 and 0.38, respectively) and lowest in the SCHIZ+DEM and non-demented PD patients (0.06 and 0.1, respectively). Thus, the APOE 4 allele is over-represented selectively in patients with dementias associated with plaques and tangles and/or cortical Lewy bodies, but not in demented schizophrenics or non-demented PD patients.     

Effects of isoflurane anesthesia on pulmonary vascular response to K+ ATP channel activation and circulatory hypotension in chronically instrumented dogs

BACKGROUND: The objective of this study was to evaluate the effects of isoflurane anesthesia on the pulmonary vascular responses to exogenous adenosine triphosphate-sensitive potassium (K+ ATP) channel activation and circulatory hypotension compared with responses measured in the conscious state. In addition, the extent to which K+ ATP channel inhibition modulates the pulmonary vascular response to circulatory hypotension in conscious and isoflurane-anesthetized dogs was assessed. METHODS: Fifteen conditioned, male mongrel dogs were fitted with instruments for long-term monitoring to measure the left pulmonary vascular pressure-flow relation. The dose-response relation to the K+ ATP channel agonist, lemakalim, and the pulmonary vascular response to circulatory hypotension were assessed in conscious and isoflurane-anesthetized (approximately 1.2 minimum alveolar concentration) dogs. The effect of the selective K+ ATP channel antagonist, glibenclamide, on the pulmonary vascular response to hypotension was also assessed in conscious and isoflurane-anesthetized dogs. RESULTS: Isoflurane had no effect on the baseline pulmonary circulation, but it attenuated (P<0.05) the pulmonary vasodilator response to lemakalim. Reducing the mean systemic arterial pressure to approximately 50 mm Hg resulted in pulmonary vasoconstriction (P<0.05) in the conscious state, and this response was attenuated (P<0.05) during isoflurane. Glibenclamide had no effect on the baseline pulmonary circulation, but it potentiated (P<0.05) the pulmonary vasoconstrictor response to hypotension in conscious and isoflurane-anesthetized dogs. CONCLUSIONS: These results indicate that K+ ATP-mediated pulmonary vasodilation and the pulmonary vasoconstrictor response to hypotension are attenuated during isoflurane anesthesia. Endogenous K+ ATP channel activation modulates the pulmonary vasoconstrictor response to hypotension in the conscious state, and this effect is preserved during isoflurane anesthesia.     

The efficiency of intermittent antegrade warm blood cardioplegia

We studied the effects of modified Calafiore technique that is intermittent antegrade warm blood cardioplegia including potassium solution and oxygenated with normothermic cardiopulmonary bypass. From January 1996 to March 1997, 45 patients who had undergone elective coronary artery bypass grafting were assigned retrospectively to two groups. Warm group: 25 patients received intermittent antegrade warm blood cardioplegia with normothermic cardiopulmonary bypass. Cold group: 20 patients received intermittent antegrade cold blood cardioplegia with slight hypothermic cardiopulmonary bypass. Preoperative variables were similar in both groups. The rate of sinus rebeating after aorta declamping with DC was lower in warm group than in cold group [warm group 2/25 (8%) versus cold group 8/20 (40%); P < 0.05]. The levels of CK and CK-MB were significantly lower in warm group than in cold group on postoperative day 0. On postoperative day 0 and day 1, the dosage of cathecholamines were significantly less for the warm group than in the cold group. Perioperative events of IABP, PMI and neurological dysfunction were not statistically different. These results show that intermittent antegrade warm blood cardioplegia is a safe and effective method for myocardial protection. But it requires further assessment.     

Warfarin potassium for impending central retinal vein occlusion

PURPOSE: We reviewed the records of 10 patients who had impending central retinal vein occlusion in order judge whether anticoagulant treatment with warfarin potassium (Warfarin) was indicated. PATIENTS: 6 men and 4 women, ranging in age from 25 to 83 (average 55) years were studied. RESULTS: Of 6 eyes, retinal hemorrhage disappeared completely within 6 months. Four patients whose visual acuity was 0.1 or less at one month needed photocoagulation. Four other patients whose late venous circulation time at fluorescein angiography improved within 30 seconds had good visual prognosis, 3 eyes of 4 patients aged 65 or older were not successful in regaining their visual acuity. CONCLUSION: Warfarin was not effective for patients who had clearly lost their visual acuity and the elderly in this series. Late venous circulation time at fluorescein angiography was a useful index for this treatment.     

Discovery of orally active nonpeptide bradykinin B2 receptor antagonists

Orally active nonpeptide bradykinin (BK) B2 receptor antagonists have been discovered by using directed random screening and chemical modification. These compounds displaced [3H]BK binding to B2 receptors in guinea-pig ileum membranes, rat uterus membranes and human lung fibroblasts with nanomolar IC50s. They did not inhibit different specific radio-ligand bindings to other receptor sites including B2 receptors. In isolated guinea-pig ileum preparations, these compounds had no agonistic effect on smooth muscle contraction at 10(-6) M, and caused parallel rightward shifts of the concentration-response curves to BK on contraction with higher p A2 values. They also blocked human B2 receptor-mediated phosphatidylinositol hydrolysis without agonistic effect. In vivo, the oral administrations of these antagonists potently inhibited BK-induced bronchoconstriction in guinea-pigs. They also reduced carrageenin-induced paw edema and caerulein-induced pancreatitis in rats. Moreover, these compounds alleviated kaolin-induced pain in mice by oral administration. These results show that our compounds are potent, selective, and orally active BK B2 receptor antagonists and that they may have therapeutic potential against inflammatory diseases and pain.     

An aminopeptidase inhibitor, bestatin, enhances progesterone and oestradiol secretion by porcine granulosa cells stimulated with follicle stimulating hormone in vitro

We examined the presence of cell surface aminopeptidase on culturedporcine granuiosa cells by employing the aminopeptidase assayusing alanine-p-nitroanilide and histochemical staining usingL-leucyl-β-naphthylamide. Porcine granuiosa cells obtainedfrom follicles 4–5 mm in diameter were cultured for 7days. The aminopeptidase assay showed that the porcine granuiosacell culture had aminopeptidase activity and that this activitywas inhibited in a dose-dependent manner by bestatin which bindsto cell surfaces and inhibits cell surface aminopeptidases.Histochemical staining also indicated that cultured granuiosacells had aminopeptidase activity. Porcine granuiosa cells werecultured in the presence or absence of porcine follicle stimulatinghormone (FSH, 3.125 nmol/1) and/or bestatin (0.4, 4.0 and 40.0µ/ml) for 7 days, and the production of progesterone andoestradiol was measured. In the presence of porcine FSH, theproduction of progesterone and oestradiol by granuiosa cellswas increased significantly by 5- and 2-fold respectively. Theseincreases were enhanced further by bestatin (40.0 (µg/ml).In the absence of porcine FSH, progesterone production was enhancedby bestatin (40.0 µg/ml), whereas no significant effectof bestatin on oestradiol secretion was observed. These findingsindicate that the inhibition of membrane-bound amino-peptidase(s)on the cell surfaces affects the steroidogenesis of granuiosacells, and that these aminopeptidase(s) are important regulatorsof granuiosa cell differentiation.     

Gene Replacement Strategies for Lung Cancer

Advances in our understanding of the molecular genetics of cancer present an opportunity to develop prevention and treatment strategies based on the reversal of specific genetic lesions. This strategy is analogous to the classic concept of gene therapy for replacement of defective or nonfunctioning genes. The gene families implicated in carcinogenesis include dominant oncogenes and tumor suppressor genes. Regional administration of viral vectors expressing wildtype p53 and antisense K-ras prevents tumor growth for tumors with the specific genetic lesions in orthotopic tumor models and mediates regression of large established tumors. These studies provide a rationale for a new clinical protocol recently approved by the National Institutes of Health Recombinant DNA Advisory Committee and Food and Drug Administration to replace a defective p53 gene with intratumor injection of recombinant retrovirus expressing wild-type p53 or elimination of activated K-ras by expression of antisense K-ras messenger RNA. If these agents are efficacious, their lack of toxicity may provide a sufficiently high therapeutic index such that they could be used as an adjuvant to surgery to treat patients with earlier stages of cancer or as prevention for second primary cancers for individuals with genetic abnormalities in premalignant lesions. Although much research needs to be done, the possibility of specific gene targeting with a high therapeutic index makes this a promising area of investigation.