Outcome prediction in patients at high risk for coronary artery disease: comparison between 99mTc tetrofosmin and 99mTc sestamibi

PURPOSE: To determine if there was any difference in the ability of physicians to predict prognosis with technetium 99m ((99m)Tc) sestamibi or (99m)Tc tetrofosmin in a large consecutive series of patients at high risk for coronary artery disease who underwent coronary angiography. MATERIALS AND METHODS: This study included 1,818 consecutive patients who underwent a rest and stress single photon emission computed tomographic (SPECT) examination with either (99m)Tc sestamibi (n = 915) or (99m)Tc tetrofosmin (n = 903) and cardiac catheterization. A clinical index was generated and consisted of clinical and demographic variables. Information concerning death, cardiovascular death, and nonfatal myocardial infarction was 93% complete during the 1.5-year study period. Cox proportional hazards models were generated to help determine the incremental contribution of SPECT sum stress score (SSS) and the imaging agent variable to the clinical index. RESULTS: Exercise was used for stress testing in 473 (52%) patients who received (99m)Tc tetrofosmin and 519 (57%) patients who received (99m)Tc sestamibi (P =.06). Cardiovascular death or myocardial infarction occurred in 130 patients. Resulting P values for chi(2) differences between models for the end points of (a) death from any cause, (b) cardiovascular death, and (c) cardiovascular death or myocardial infarction showed that SSS combined with clinical index was a significantly better model than adjusting for only baseline characteristics (P =.001, P <.001, P =.004, respectively). Incremental addition of either (99m)Tc tetrofosmin or (99m)Tc sestamibi to those models containing SSS and the clinical index did not show further significant improvement (P =.87, P =.88, and P =.26 for death from any cause, cardiovascular death, and cardiovascular death or myocardial infarction, respectively). CONCLUSION: This study shows that the type of clinically available (99m)Tc-labeled myocardial perfusion agents should not affect interpretation of results for risk stratification and prognostic assessment.     

Simultaneous determination of metronidazole and spiramycin I in human plasma, saliva and gingival crevicular fluid by LC-MS/MS

An analytical validation of a new liquid chromatographic-mass spectrometric (LC-MS/MS) method for simultaneous determination of metronidazole and spiramycin I concentrations in human plasma, saliva and gingival crevicular fluid (GCF) is presented. Ornidazole was used as an internal standard, and sample pre-treatment consisted of a liquid-liquid extraction. Chromatographic separation was achieved on a 5 microm Kromasil C18 column (150 mm x 4.6 mm i.d., particle size 5 microm), with a gradient using acetonitrile, water and formic acid at a flow rate of 0.9 ml/min. The methods were validated in terms of intra- and inter-batch precision (<7.1% in plasma, 12% in saliva and 9.2% in GCF, respectively) and accuracy (within +/-8.7% in plasma, within +/-8.7%, except LDQ level within +/-15.4% in saliva and within +/-10.7% in GCF), linearity, specificity, recovery (extraction efficiency), matrix effect, dilution process, stability in human plasma and saliva after three freeze-thaw cycles, stability in human plasma and saliva at ambient temperature and stability of the extracts in the automatic injector of the HPLC system. The methods are applicable for accurate and simultaneous monitoring of the plasma, saliva and gingival crevicular fluid levels of metronidazole and spiramycin I from pharmacokinetic studies.     

Analysis of the thermal and pH stability of human respiratory syncytial virus

Respiratory syncytial virus (RSV) was studied as a function of pH (3-8) and temperature (10-85 degrees C) by fluorescence, circular dichroism, and high-resolution second-derivative absorbance spectroscopies, as well as dynamic light scattering and optical density as a measurement of viral aggregation. The results indicate that the secondary, tertiary, and quaternary structures of RSV are both pH and temperature labile. Derivative ultraviolet absorbance and fluorescence spectroscopy (intrinsic and extrinsic) analyses suggest that the stability of tertiary structure of RSV proteins is maximized near neutral pH. In agreement with these results, the secondary structure of RSV polypeptides seems to be more stable at pH 7-8, as evaluated by circular dichroism spectroscopy. The integrity of the viral particles studied by turbidity and dynamic light scattering also revealed that RSV is more thermally stable near neutral pH and particularly prone to aggregation below pH 6. By combination of the spectroscopic data employing a multidimensional eigenvector phase space approach, an empirical phase diagram for RSV was constructed. The pharmaceutical utility of this approach and the optimal formulation conditions are discussed.     

AM3 inhibits LPS-induced iNOS expression in mice

We have analyzed the effect of a patented glycoconjugate of natural origin, AM3 (commercially available under the name Inmunoferon) in the expression of iNOS induced by administration of LPS in mice. We have observed that oral treatment with the drug daily for 6 days reduced the levels of expression of iNOS induced by an intravenous pulse of LPS. This effect was significant in the lungs and kidneys, but it was much more marked in the liver. In addition, the levels of nitric oxide in serum were clearly decreased upon treatment with AM3. Together, these results suggest that AM3 modulates the nitric oxide response and points to a possible role for AM3 in the control of the inflammatory response.     

First-line treatment with irinotecan and raltitrexed in metastatic colorectal cancer. Mature results of a multicenter phase II study

OBJECTIVES: The combination of irinotecan and raltitrexed is safe and active in 5-fluorouracil-refractory, metastatic colorectal cancer (CRC), with the advantage of its convenient three-weekly schedule. The aim of this multicenter phase II study was to assess its efficacy and toxicity in first-line treatment. METHODS: Between May 2000 and March 2001, 62 previously untreated patients received irinotecan (350 mg/m(2)) plus raltitrexed (3 mg/m(2)), with courses repeated every 21 days. Objective response was assessed every three courses, and treatment maintained until tumor progression or unacceptable toxicity. RESULTS: A total of 331 cycles were administered, with a median of five cycles per patient (range, 1-16). Seventeen patients achieved a partial response and 2 a complete response, for an overall intention-to-treat response rate of 30% (95% confidence interval, 18-44%). The incidence of grade 3-4 toxicity per patient was diarrhea (27%), emesis (13%), anemia (12%), neutropenia (9%), and asthenia (7%). Three patients (5%) died from treatment-related adverse events (diarrhea plus neutropenia). The median potential follow-up is now 37 months. Median survival was 12.2 months, and median time to progression was 6.3 months. CONCLUSIONS: The combination of irinotecan plus raltitrexed is an easy comfortable schedule for patients with metastatic CRC, but both efficacy and toxicity results seem suboptimal for first-line treatment.     

Preoperative risk evaluation in beating-heart coronary artery bypass surgery

INTRODUCTION AND OBJECTIVES: Operative risk stratification scales for use in cardiac surgery have been developed for patients who undergo procedures using extracorporeal circulation. The aims of the present study were to investigate the use of six preoperative risk stratification scales in patients undergoing beating-heart surgery and to identify risk factors for major complications and mortality in our group of patients who underwent revascularization using this approach. PATIENTS AND METHOD: Between January 1997 and December 2002, we performed 762 coronary artery bypass operations on the beating heart; 61 patients suffered major complications (8%) and 25 died (3.3%). Risk factors for major complications and death were identified using logistic regression analysis of prospectively collected data. The following risk scores were calculated for each patient: Parsonnet 95, Parsonnet 97, Euroscore, Cleveland, Ontario, and French. Receiver operating characteristic curves were used to compare the ability of each scale to predict mortality and major complications. RESULTS: In our patient group, the preoperative variables associated with increased risk were: need for cardiopulmonary resuscitation, renal dysfunction, peripheral vasculopathy, and the presence of severe left main coronary artery disease, three-vessel disease, or an impaired ejection fraction. CONCLUSIONS: Mortality and major complications were best predicted by the Parsonnet 95 and Euroscore scales.     

Recurrent Candida tropicalis meningitis

Candida meningitis, a previously rare occurrence, has been increasing in prevalence and often is a result of complications of neurosurgery. We describe the case of a 49-year-old man who presented with headache, vertigo, intermittent blurred vision, and multiple episodes of nausea and vomiting. Computed tomography (CT) showed a left cerebellar hemorrhage with obliteration of the fourth ventricle causing hydrocephalus. He had an occipital craniotomy with transcondylar evacuation of the hemorrhage and placement of a temporary ventriculostomy. The hospital stay was prolonged because of postsurgical complications, and Candida tropicalis meningitis developed. Treatment was started with 400 mg of fluconazole administered intravenously every 12 h. In vitro susceptibility testing showed a minimum inhibitory concentration (MIC) to fluconazole of 1 microg/mL. Fluconazole was therefore continued orally for a total of 60 days, and the patient remained asymptomatic for 2 years. He then presented with increased vertigo and ataxia. Cerebrospinal fluid cultures grew C. tropicalis, which again showed susceptibility to fluconazole with a MIC of 1 microg/mL, identical to that in the previous infection. However, a second course of fluconazole failed to control the infection despite adequate cerebrospinal fluid levels.     

Phosphatidic acid and diacylglycerol generation is regulated by insulin in cerebral cortex synaptosomes from adult and aged rats

Insulin receptor associated with the cerebral cortex (CC) has been shown to be involved in brain cognitive functions. Furthermore, deterioration of insulin signaling has been associated with age-related brain degeneration. We have reported previously that aging stimulates phospholipase D/phosphatidate phosphohydrolase 2 (PLD/PAP2) pathway in CC synaptosomes from aged rats, generating a differential availability of their reaction products: diacylglycerol (DAG) and phosphatidic acid (PA). The aim of this work was to determine the effect of aging on DAG kinase (DAGK), as an alternative pathway for PA generation, and to evaluate the effect of insulin on PLD/PAP2 pathway and DAGK. PLD, PAP2, and DAGK activities were measured using specific radiolabeled substrates in CC synaptosomes from adult (4 months old) and aged rats (28 months old). In adult animals, in the presence of the tyrosine phosphatase inhibitor (sodium o-vanadate), insulin stimulated PLD activity at 5 min incubation. DAGK activity was also increased at the same time of incubation and PAP2 was inhibited. In aged animals, PLD activity was not modified by the presence of insulin plus vanadate, PAP2 was inhibited, and DAGK was stimulated by the hormone. Insulin, vanadate, and the combination of both induced protein tyrosine phosphorylation in adult CC synaptosomes. Aged rats showed a lower level of protein phosphorylation with respect to adult rats. Our results show that insulin modulates PA and DAG availability through the regulation of PLD/PAP2 and DAGK pathways in adult rat CC synaptosomes. Additionally, we demonstrated that PA and DAG generation is regulated differentially by insulin during aging.     

Distribution of GABA, calbindin and nitric oxide synthase in the developing chick entopallium

The distribution of GABA, calbindin and neuronal nitric oxide synthase (nNOS) was analyzed in the developing avian entopallium. The study was carried out in chick embryos from embryonic day (E)8 to hatching postnatal day (P)0, using immunohistochemical methods. At E8, GABA-positive cells were observed in pallial regions. Neither calbindin nor nNOS-immunoreactive cells were observed. At E10, the number of GABA neurons in the prospective entopallium increased and also nNOS cells were observed. Lightly stained nNOS neurons predominated over intensely stained ones. Calbindin immunoreactivity was not observed in the entopallium. At E12, the entopallial complex appeared as the pallial region displaying the highest density of GABA neurons. Also the whole entopallium displayed an intensely stained calbindin neuropil with many embedded stained cells. From E12 on, there was a decrease in the expression of nNOS. At E14-16, both GABA and calbindin-immunoreactive neurons were numerous and homogeneously distributed within the entopallium. The whole entopallium displayed a moderately stained neuropil. From E18 to P0, GABA and nNOS immunoreactivities remained similar to previous stages. At these stages, calbindin immunoreactivity within the entopallium consisted of a moderately stained central region bordered dorsally by a pale stained region. These two areas could correspond to the entopallial core and the perientopallial belt, respectively.     

Distribution of nitric oxide-producing neurons in the developing and adult mouse amygdalar basolateral complex

We analysed the expression of neuronal nitric oxide synthase (nNOS) in the mouse amygdalar basolateral complex (BLC) from embryonic day 15.5 to adult, using standard immunohistochemical methods. Our results indicate that each nucleus of the amygdalar basolateral complex displays a distinct nNOS expression pattern, which is established during the ontogenesis with minor changes in the adult. The basomedial nucleus (BM) exhibited the highest nNOS immunoreactivity in the basolateral complex, observable from early embryonic stages, whereas the lateral nucleus displayed the lowest level of immunoreactivity. The expression pattern for nNOS in the basolateral nucleus differed substantially from that of the lateral and basomedial nuclei, showing a slightly increase in the number of nNOS cells and neuropil staining from intermediate developmental until early postnatal stages. Two distinct types of nitrergic neurons, densely and lightly stained neurons, were observed in the developing basolateral complex. Both types of putative nitrergic neurons were unevenly distributed in the basolateral complex. On the basis of previous data regarding the colocalization between nNOS and GABA in the mouse claustrum, we suggest that nNOS expressing neurons in the basolateral amygdalar complex are both GABAergic and non-GABAergic.