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PubMedDate not supplied

Energy transfer from chemically attached rhodamine 101 to adsorbed methylene blue on microcrystalline cellulose particles.

Rhodamine 101 (R101) was chemically attached onto microcrystalline cellulose and methylene blue (MB) was adsorbed to a sample bearing nearby 6 x 10(-7) mol R101 (g cellulose)(-1). The system was studied by reflectance and emission spectroscopy in the solid state. R101 shows no aggregation in these conditions and, while pure MB builds up dimers on cellulose even at 2 x 10(-8) mol g(-1), in the presence of R101 no evidence on selfaggregation or heteroaggregation is found up to around 10(-6) mol g(-1). No exciplex formation is found as well. The overall fluorescence quantum yield measured on thick layers, once re-absorption effects are accounted for, amounts to 0.80 +/- 0.07 for pure R101 and decreases steadily on increasing the concentration of MB. Results demonstrate the occurrence of radiative and nonradiative singlet energy transfer from R101 to MB. For thick layers of particles, the combined effect of both kinds of energy transfer amounts to nearly 80% at the highest acceptor concentration, while nonradiative transfer reaches 60% both for thin and optically thick layers. The dependence of nonradiative energy transfer efficiencies on the acceptor concentration is analyzed and the origin of departures from Förster behavior at low acceptor concentration is discussed.

Journal Article↗
PubMedDate not supplied

Evaluation of the modified leprosy elimination campaign in a high leprosy endemic district of Jharkhand.

An evaluation of the third Modified Leprosy Eradication Campaign (MLEC) was carried out in Potka block in the high endemic district of East Singhbhum, Jharkhand State, India, by our external evaluation team, from 29 October to 8 November 2001. The searchers in this block detected 389 suspects during the MLEC; of these, 181 (46%) were examined, and 69 (38%) of them were confirmed as cases by the Programme staff. The evaluators examined 189 (48.5%) of the total 389 suspects detected by the searchers, including 31 of the 69 cases confirmed by the Programme staff. Concordance of diagnosis of leprosy cases by the Programme staff and the evaluators was found to be high (90%). However, concordance of the type of leprosy was found to be variable (PB 38%, MB 72%, SSL 100%). Specificity and sensitivity of diagnosis by the Programme staff (as against those by the evaluators) were found to be 85.7% and 79.2% respectively. There was no case of re-registration. The evaluators examined 108 of the suspects detected by the Search Team, but not screened by the Programme staff, and diagnosed 47 cases (44%; PB 20, MB 9, SSL 18) from among them. The evaluators also diagnosed additional 30 new cases (PB 18, MB 5, SSL 7), during their visit. An assessment of knowledge about the disease and treatment among confirmed cases revealed that most of the patients did not know correctly about their disease. All the cases were referred by the searchers. About 45% of cases were aware of the duration for which they needed to take the treatment, 97% of cases showed the blister calendar packs and had taken the supervised dose. Availability of MDT to the patients and drug compliance were found to be adequate. Assessment of the impact of IEC activities on the awareness of leprosy among the community showed that about 50% of those interviewed were aware of the campaign. Most of them had information about the availability of leprosy drugs and knew that treatment was free. A majority of those aware of the disease said that they would refer suspects, if they come across any, to PHC centres for treatment.

Evaluation Studies as Topic↗
PubMed2006

Targeting the NF-kappa B pathway in estrogen receptor negative MDA-MB-231 breast cancer cells using small inhibitory RNAs.

Cancer cells in order to survive are often mutated to block apoptosis. One chemotherapeutic option is the re-establishment of apoptosis. An example of such a therapy is the PKC inhibitor Gö6976, which activates apoptosis and shrinks in vivo tumors in estrogen receptor-negative breast cancers. We proposed as a mechanism blockage of activation of the transcription factor NF-kappaB, which is anti-apoptotic and often elevated in cancers. Over recent years, questions have arisen regarding the specificity of these "small-molecule inhibitors." We have therefore explored the role of NF-kappaB inhibition in MDA-MB-231 breast cancer cells using small inhibitory RNAs (siRNA). siRNAs designed against NF-kappaB protein p65 (RelA) and IKKalpha, IKKbeta, and IKKgamma, strongly decreased the target proteins. But, unlike Gö6976, they did not decrease basal NF-kappaB or cause apoptosis. In particular, the decrease in p65 protein had no effects on apoptosis or cell proliferation, thus questioning the importance of NF-kappaB alone in the maintenance of these cells. Furthermore, the proteasome inhibitor MG-132 caused loss of IkappaBalpha, and an increase of it is phosphorylated form, but basal NF-kappaB was unchanged, whilst activation of NF-kappaB by TNFalpha was completely inhibited, suggesting that MG-132 activity is independent of constitutive NF-kappaB activation. We ascribe these differences to the specificity of inhibition by siRNAs as compared to the well-known non-specificity of small-molecule inhibitors. We conclude that the mutations in these cancer cells made them resistant to apoptosis, by elevating their NF-kappaB and activating other basal pathways that are blocked by Gö6976 but not by IKK and p65 siRNAs.

Breast Neoplasms↗
PubMed1997

Myocardial protection by pressure- and volume-controlled continuous hypothermic coronary perfusion (PVC-CONTHY-CAP) in combination with ultra-short beta-blockade and nitroglycerine.

The aim of the study was to validate clinically a new technique of myocardial protection developed for intra- and extra-cardiac surgery on the beating heart. The concept combines the principle of continuous pressure- and volume-controlled coronary artery perfusion (PVC-CONTHY-CAP) with the specific myocardioprotective effects of hypothermia and nitrates and, on the other hand, with the beta-blocker-mediated reduction of chronotropy and inotropy necessary for convenient surgery. Under standard ECC conditions after cross-clamping the aorta coronary perfusion with oxygenated blood enriched with nitroglycerine (10 micrograms/kg/h) and esmolol (0.05 mg/ml flow/min) is started via an additional perfusion cannula placed in the aortic root. The temperature of the perfusate is maintained at 32 degrees C, the intraaortic pressure at 40-70 mmHg and the perfusion flow in the range 0.8-1.0 ml/g heart muscle/min. In CABG procedures an additional perfusion catheter is used for perfusion of distal coronary artery segments. Using this technique 100 consecutive patients, adults and children, were operated on between 2/96 and 8/96. In 84 adult patients (age: 45-82 yrs), 78 CABG procedures (54 elective, 13 urgent, 11 acute) with a mean bypass count of 3.7 (range 1-7), 69 ITA grafts, 72 grafts to CX, and 3 MVRec/MVRpl, and 6 pure MVRec/MVRpl procedures (1 urgent, 1 emergency) were performed. The mean coronary perfusion time was 48 min (range 21-88 min). In 5 patients perioperative infarction (CABG; 1 emergency after PTCA, 4 elective) with significant increase of CK-MB values (57-98 U/L) occurred. In the 4 elective patients (3 with diabetes mellitus) re-intervention was not possible due to small-vessel disease. In one patient with preoperative infarction IABP was necessary. No patient died. There were 16 children (age: 4weeks-16 yrs): VSD, n = 6, AV-C, n = 2, TOF, n = 1, MVRec, n = 1, DORV (Rastelli), n = 2, SV (TCPC), n = 3, and PV obstruction, n = 1. The mean coronary perfusion time was 97 min (range: 27-260 min). The mean ICU stay 3.9 d (range: 1-10 d). One child died (TCPC) on the 10th postoperative day due to multi-organ failure. In conclusion, PVC-CONTHY-CAP is designed especially for emergency and urgent procedures, i.e. patients with PTCA-related complications, patients with severely depressed LV function, and patients with complex congenital cyanotic heart defects. Using PVC-CONTHY-CAP, coronary artery bypass grafting as well as intracardiac procedures for congenital and acquired heart defects can be performed safely and conveniently, the system is easy to handle for both the cardiac surgeon and perfusionist. Due to its pharmacological properties continuous intracoronary application of nitrates in combination with hypothermia seems to be essential as a preventive treatment modality for the ischemic state.

Adolescent↗
PubMed1993

Is ST segment re-elevation associated with reperfusion an indicator of marked myocardial damage after thrombolysis?

OBJECTIVES: The significance of ST segment re-elevation at reperfusion by thrombolysis was evaluated. BACKGROUND: The significance of ST re-elevation has not been studied. Hence, we evaluated whether ST re-elevation is an indicator of marked myocardial necrosis after reperfusion. METHODS: Twelve-lead electrocardiograms were recorded serially, before thrombolysis and immediately after each coronary angiographic procedure during thrombolysis. RESULTS: In 32 patients with acute myocardial infarction, 15 showed transient ST re-elevation at reperfusion (group 1) and 17 showed reduction (group 2). Peak creatine kinase (CK) and CK-MB isoenzyme activity levels were significantly higher in group 1 than in group 2. Twelve patients in group 1 had strongly positive findings on early technetium-99m pyrophosphate scintigraphy, compared with one patient in group 2 (p < 0.001). The regional ejection fraction did not increase from the acute phase to the chronic phase in group 1. The ST deviation before thrombolysis was significantly greater in group 1 than in group 2 (p < 0.001). All 14 patients in group 1 showed Thrombolysis in Myocardial Infarction (TIMI) grade 0 flow and 12 of these patients did not have good collateral flow before thrombolysis. CONCLUSIONS: These data suggest that 1) ST re-elevation at reperfusion is a sign of limited myocardial salvage by thrombolysis, and 2) high ST elevation and TIMI grade 0 flow without good collateral flow before thrombolysis may be predictive variables for marked myocardial necrosis after reperfusion.

Aged↗
PubMed1998

The steroid hormone 20-hydroxyecdysone enhances neurite growth of Drosophila mushroom body neurons isolated during metamorphosis.

Mushroom bodies (MBs) are symmetrically paired neuropils in the insect brain that are of critical importance for associative olfactory learning and memory. In Drosophila melanogaster, the MB intrinsic neurons (Kenyon cells) undergo extensive reorganization at the onset of metamorphosis. A phase of rapid axonal degeneration without cell death is followed by axonal regeneration. This re-elaboration occurs as levels of the steroid hormone 20-hydroxyecdysone (20E) are rising during the pupal stage. Based on the known role of 20E in directing many features of CNS remodeling during insect metamorphosis, we hypothesized that the outgrowth of MB axonal processes is promoted by 20E. Using a GAL4 enhancer trap line (201Y) that drives MB-restricted reporter gene expression, we identified Kenyon cells in primary cultures dissociated from early pupal CNS. Paired cultures derived from single brains isolated before the 20E pupal peak were incubated in medium with or without 20E for 2-4 d. Morphometric analysis demonstrated that MB neurons exposed to 20E had significantly greater total neurite length and branch number compared with that of MB neurons grown without hormone. The relationship between branch number and total neurite length remained constant regardless of hormone treatment in vitro, suggesting that 20E enhances the rate of outgrowth from pupal MB neurons in a proportionate manner and does not selectively increase neuritic branching. These results implicate 20E in enhancing axonal outgrowth of Kenyon cells to support MB remodeling during metamorphosis.

Animals↗
PubMed2003

Epigenetic silencing of the HIC-1 gene in human medulloblastomas.

The HIC-1 (hypermethylated in cancer) candidate tumor suppressor gene is located on chromosome 17p13.3, a region frequently deleted in medulloblastomas (MBs). MBs arising in the cerebellum represent the most common malignant brain tumors in children. In this study we have analyzed the sequence, methylation, and expression status of the HIC-1 gene in MBs. Hypermethylation of the 5'UTR and/or second exon of HIC-1 was detected in 33/39 (85%) of MB biopsies and in 7/8 (88%) of MB cell lines by methylation-specific PCR. There was a significant correlation (p < 0.001) between HIC-1 methylation and lack of transcription as determined by competitive RT-PCR. Treatment of the MB cell lines Daoy and MEB-MED-8A with 5-aza-2'deoxycytidine led to re-expression of HIC-1 transcripts, indicating a silencing of HIC-1 by CpG island methylation. Mutation analysis of the coding region of HIC-1 revealed a single deletion leading to an in-frame deletion of 4 amino acids in the second exon of HIC-1 (1/68, 1.5%). Our data indicate that a significant number of MBs exhibit strikingly reduced HIC-1 expression caused by altered CpG island methylation. These data suggest that epigenetic silencing of HIC-1 may well contribute to the pathogenesis in the majority of MBs.

Adolescent↗
PubMed2000

Transcriptional activation of estrogen receptor alpha in human breast cancer cells by histone deacetylase inhibition.

Recent findings have established a connection between DNA methylation and transcriptionally inactive chromatin characterized by deacetylated histones. Because the absence of estrogen receptor alpha (ERalpha) gene expression has been associated with aberrant methylation of its CpG island in a significant fraction of breast cancers, we tested whether histone deacetylase activity contributes to the transcriptional inactivation of the methylated ER gene in a panel of ER-negative human breast cancer cells. Treatment of these cells with trichostatin A, a specific histone deacetylase inhibitor, led to dose- and time-dependent re-expression of ER mRNA as detected by reverse transcription-PCR without alteration in ERalpha CpG island methylation. Trichostatin A-induced ER re-expression was associated with increased sensitivity to DNase I at the ER locus in MDA-MB-231 cells. These data implicate inactive chromatin mediated by histone deacetylation as a critical component of ER gene silencing in human breast cancer cells. Therefore, histone deacetylation may be a potential target for therapeutic intervention in the treatment of a subset of ER-negative breast cancers.

Base Sequence↗
PubMed2006

Re-activation of a dormant tumor suppressor gene maspin by designed transcription factors.

The controlled and specific re-activation of endogenous tumor suppressors in cancer cells represents an important therapeutic strategy to block tumor growth and subsequent progression. Other than ectopic delivery of tumor suppressor-encoded cDNA, there are no therapeutic tools able to specifically re-activate tumor suppressor genes that are silenced in tumor cells. Herein, we describe a novel approach to specifically regulate dormant tumor suppressors in aggressive cancer cells. We have targeted the Mammary Serine Protease Inhibitor (maspin) (SERPINB5) tumor suppressor, which is silenced by transcriptional and aberrant promoter methylation in aggressive epithelial tumors. Maspin is a multifaceted protein, regulating tumor cell homeostasis through inhibition of cell growth, motility and invasion. We have constructed artificial transcription factors (ATFs) made of six zinc-finger (ZF) domains targeted against 18-base pair (bp) unique sequences in the maspin promoter. The ZFs were linked to the activator domain VP64 and delivered in breast tumor cells. We found that the designed ATFs specifically interact with their cognate targets in vitro with high affinity and selectivity. One ATF was able to re-activate maspin in cell lines that comprise a maspin promoter silenced by epigenetic mechanisms. Consistently, we found that this ATF was a powerful inducer of apoptosis and was able to knock down tumor cell invasion in vitro. Moreover, this ATF was able to suppress MDA-MB-231 growth in a xenograft breast cancer model in nude mice. Our work suggests that ATFs could be used in cancer therapeutics as novel molecular switches to re-activate dormant tumor suppressors.

Amino Acid Sequence↗
PubMed1997

[Rotational atherectomy (Rotablator) for percutaneous transluminal coronary angioplasty].

BACKGROUND: The use of Rotablator in percutaneous transluminal coronary angioplasty attempts to reduce the atheromatous plaque abrading it and fragmenting the parietal calcium of the artery. AIM: To report our experience with the use of Rotablator. PATIENTS AND METHODS: Rotational atherectomy was performed in 189 patients aged 60.8 +/- 11 years (154 men). The clinical indication for the procedure was chronic angina in 22%, unstable angina in 44%, myocardial infarction in 21%, silent angina in 7% and re-stenosis in 6%. One hundred seventy seven patients were followed for a mean of 15.9 +/- 6.3 months. RESULTS: Two hundred thirty six stenoses in 215 coronary arteries were treated with a 98.7% angiographic success rate. One patient had a Q infarction and no patient died or required emergency surgery. Fourteen patients had rises in CK MB enzymes (non Q infarction). Three patients had a pseudoaneurism and three had bleedings that required transfusion. Of the followed patients, 33 had a clinically suspected re-stenosis, that was angiographically confirmed in 23. Cardiac mortality was 2.3%. Seventy nine percent of patients had an evolution without angina or coronary events. CONCLUSIONS: Percutaneous transluminal coronary angioplasty with the use of Rotablator had a high immediate success rate and a low incidence of complications. The clinical evolution of patients has been favorable with a low incidence of mortality and ischemic events.

Aged↗
PubMed2001

Safety and efficacy of thrombolysis with alteplase (50 mg) plus tirofiban versus alteplase (100 mg) alone in acute myocardial infarction: preliminary findings.

BACKGROUND: The goal of therapy in acute myocardial infarction (AMI) is the complete and timely restoration of coronary blood flow. Platelets have a pivotal role in the pathophysiology of AMI. The study was aimed at evaluating the safety and efficacy of the combination of 50 mg alteplase plus tirofiban vs 100 mg alteplase in AMI patients. METHODS: One hundred twenty patients (83 males, 37 females; mean age 54.3 +/- 8 years) were hospitalized for suspected AMI within 6 hours of the onset of symptoms. All patients presented pain and persistent ST-segment elevation, were suitable candidates for thrombolysis (1st episode) and were randomized (double blind) into two groups. Group A (n = 60,42 males, 18 females) received 50 mg alteplase (15 mg as bolus, followed by an infusion of 35 mg over 60 min) in combination with tirofiban (0.4 mcg/kg/min for 30 min followed by an infusion of 0.1 mcg/kg/min for 3 days). Group B (n = 60, 41 males, 19 females) received 100 mg of accelerated-dose alteplase alone. Reperfusion criteria were defined as follows: > 50% reduction in the ST-segment elevation; resolution of chest pain; double marker of creatine kinase (CK) and CK-MB activity 2 hours after the start of thrombolysis; reperfusion arrhythmias within the first 120 min of thrombolysis. The blood pressure, heart rate and ECG were continuously monitored. The mortality, re-AMI, recurrent angina, major and minor bleeding, and emergency bypass surgery or coronary angioplasty were checked. RESULTS: The groups were similar with regard to clinical data, risk factors, time elapsed from the onset of symptoms to thrombolytic therapy and AMI localization. Forty-seven patients (78.3%) from group A showed reperfusion (15-60 min) vs 25 patients (41.7%) from group B (43-105 min after the end of full-thrombolysis, p = 0.01). Group A patients showed an earlier CK peak and lower CK and CK-MB peaks than those in the control group (p = 0.0001, p = 0.011, p = 0.005, respectively). Nine patients (7.5%) died: 6 (10%) in group B and 3 (5%) in group A (p = NS). A non-fatal re-AMI occurred in 8 patients from group A and in 4 patients from group B (p = NS). Recurrent angina occurred in 27 patients (45%) from group A and in 11 (18.3%) from group B (p = 0.037). Twenty-three of these patients underwent urgent coronary angioplasty (17 from group A and 6 from group B) and 3 from group A and 1 from group B underwent urgent coronary artery bypass grafting (p = NS). The frequency of minor bleeding was higher in group A than in group B (56.7 vs 25%, p = 0.033). No major bleeding was observed in the study groups. At the predischarge echocardiogram, the ejection fraction was higher in group A than in group B (50 +/- 9 vs 44 +/- 7%, p = 0.001). CONCLUSIONS: Our data suggest that the combination of glycoprotein IIb/IIIa inhibitors plus alteplase is feasible in AMI patients and that the increased risk of bleeding is an acceptable risk considering the advantage in terms of the reduction in the extent of an AMI. In addition, this combination can allow one to gain time when it is necessary to perform mechanical revascularization in patients admitted to a hospital without an interventional cardiology laboratory or in those who have to be referred to another hospital for urgent coronary artery bypass grafting.

Creatine Kinase↗
PubMed1991

Metabolism of lipoidal derivatives of estradiol-17-beta in human mammary cancer tissue and cell lines.

Estradiol-17 beta (E2) is converted exclusively to intracellular metabolites, termed lipoidal estrogens [long chain fatty acid 17 beta-esters (E2-L)], by human mammary cancer tissue and cell lines. In order to further evaluate the biological role of lipoidal estrogens, rates of saturation of the estrogen receptor (ER) along with formation of [3H]E2-L have been measured in human mammary cancer cells exposed to 5 nM [3H]E2. Extensive specific binding of E2 to ER in MCF-7 cells (approximately 37%) and ZR-75-1 cells (approximately 62%) occurred before appreciable synthesis of E2-L was evident and the maximum level of E2-L attained was only 3-9% of the E2 specifically bound to ER. In these ER positive cell lines, and in the ER negative cell line MDA-MB-231, an initial rise in the rate of E2-L formation was followed by a decrease at approximately 6 min and re-establishment of a new rate, indicating turnover of the E2-L fraction by esterification-de-esterification reactions. This data does not support the concept that E2-L acts in the transport of E2 to nuclear receptors, but rather than liberation of E2 from E2-L could serve to maintain occupancy of ER necessary for initiation of DNA synthesis. The esterase, as studied in pooled human mammary cancer tissue, was found to hydrolyse E2-17 beta-long chain fatty acid esters at different rates--the enzyme being less active towards E2-17 beta-stearate compared to E2-17 beta-oleate, -linoleate and -linolenate. Esterase activity was significantly higher in MDA-MB-231 cells compared to MCF-7 cells. Treatment of MCF-7 cells with E2 did not alter the specific activity of the esterase towards E2-17 beta-oleate as substrate. Similarly, addition of dibutyryl c-AMP to ZR-75-1 cell cultures was without effect on E2-L, both during the time when E2-L was accumulating, or during a subsequent phase when E2-L was decreasing following transfer to medium lacking E2. Calcitonin, which increases endogenous c-AMP in MCF-7 cells, had no effect on E2-L in this latter phase using this cell line. Thus, no evidence could be provided that the esterase was under E2 control, or control by polypeptide hormones which utilize c-AMP as a second messenger.

Breast Neoplasms↗
PubMed1977

Expression and thermal stability of simian virus 40 tumor-specific transplantation antigen and tumor antigen in wild type- and tsA mutant-transformed cells.

We have explored aspects of a suggested relationship between the expression of simian virus 40 tumor-specific transplantation antigen (TSTA) and tumor antigen (TA). A unique rat embryo cell line transformed by a temperature-sensitive A mutant that loses TA during exposure to the nonpermissive temperature (A28-RE) was found to lose TSTA. On the other hand, a typical control tsA-transformed cell line (A239-MB) expressed both TA and TSTA at the non-permissive temperature. TA in lysates obtained from A239-MB cells was found to be three to four times more thermolabile by covwt-mb) when incubated at either 33 or 40 degrees C. These data complement previous reports using TA from lytic infection and are consistent with the suggestion that TA is virus encoded. In contrast to TA, which even in wild-type-transformed cells was completely destroyed in less than 10 min at 50 degrees C, TSTA, assayed in vivo by tumor rejection, and tumor-specific surface antigen(s) TSSA) defined by an in vitro cytolytic assay, were thermostabile. Even after 24 h of incubation of extracts of 50 degrees C, high levels of TSTA and TSSA activity were present. Since these surface antigens when obtained from cells transformed by tsA mutants were also thermostabile, they could not be distinguished from the wild-type antigens. These results (i) indicate a coordinate expression of TA and TSTA in transformed cells; (ii) confirm that TA is virus encoded; and (iii) confirm that tha antigenic and immunogenic determinants that characterize TA and TSTA activities are distinct. However, the possibility that TSTA, like TA, is of viral rather than cellular origin is not excluded.

Animals↗