Prognostic Value of D-dimer to Lymphocyte Ratio (DLR) in Hospitalized Coronavirus Disease 2019 (COVID-19) Patients: A Validation Study in a National Cohort

BACKGROUND

This study aimed to validate the role of the D-dimer to lymphocyte ratio (DLR) for mortality prediction in a large national cohort of hospitalized coronavirus disease 2019 (COVID-19) patients.

METHODS

A retrospective, multicenter, observational study that included hospitalized patients due to SARS-CoV-2 infection in Spain was conducted from March 2020 to March 2022. All biomarkers and laboratory indices analyzed were measured once at admission.

RESULTS

A total of 10,575 COVID-19 patients were included in this study. The mean age of participants was 66.9 (±16) years, and 58.6% (6202 patients) of them were male. The overall mortality rate was 16.3% (n = 1726 patients). Intensive care unit admission was needed in 10.5% (n = 1106 patients), non-invasive mechanical ventilation was required in 8.8% (n = 923 patients), and orotracheal intubation was required in 7.5% (789 patients). DLR presented a c-statistic of 0.69 (95% CI, 0.68-0.71) for in-hospital mortality with an optimal cut-off above 1. Multivariate analysis showed an independent association for in-hospital mortality for DLR > 1 (adjusted OR 2.09, 95% CI 1.09-4.04; p = 0.03); in the same way, survival analysis showed a higher mortality risk for DLR > 1 (HR 2.24; 95% CI 2.03-2.47; p < 0.01). Further, no other laboratory indices showed an independent association for mortality in multivariate analysis.

CONCLUSIONS

This study confirmed the usefulness of DLR as a prognostic biomarker for mortality associated with SARS-CoV-2 infection, being an accessible, cost-effective, and easy-to-use biomarker in daily clinical practice.

Euro-Burn I: Assessment of burnout syndrome in health workers in a mediterranean country during the SARS-CoV-2 pandemic

BACKGROUND

Burnout syndrome (BS) has a negative impact among health professionals.

AIMS

Our research objective is to quantify the level of burnout in health workers of the Spanish National Health System during the COVID-19 pandemic using and comparing two independent measurement instruments.

METHODS

Cross-sectional, descriptive and multicenter study conducted through an anonymous online survey among health workers of the National Health System, measuring the level of burnout using the Maslach Burnout Inventory (MBI) and the Copenhagen Burnout Inventory (CBI).

RESULTS

A total of 448 questionnaires were analyzed, the mean age of the participants was 43.53 years (range: 20-64), 365 (81.5%) women. 161 (35.9%) participants presented BS measured with the MBI and 304 (67.9%) measured with the CBI. Regarding work contract, those who had greater job stability presented a higher degree of cynicism with respect to the eventual ones (p = .010), the eventual ones presenting higher mean scores in professional efficacy (p = .034). Urban workers had higher scores of exhaustion (p < .001) and cynicism (p < .001) than those living in rural areas. When comparing both tests, a high predictive value for exhaustion and cynicism was found to measure BS through the CBI (AUC = 0.92 and 0.84, respectively) and a low AUC with respect to the predictive value for efficacy (AUC = 0, 59).

CONCLUSIONS

The results obtained show a high level of BS among the health workers who participated in our study. Both tests have an excellent correlation in the degree of exhaustion and cynicism, but not in efficacy. The BS measurement must be performed with at least two validated instruments to increase its reliability.

Effectiveness of the contingency plan for social and health care during the COVID-19 pandemic in a health district in northwestern Spain

INTRODUCTION

During the COVID-19 pandemic, healthcare facilities have implemented contingency plans to minimize the consequences of this pathology however, the deployment and results of these contingency plans are scarcely shared.

OBJECTIVES

To describe the implementation of the contingency plan in the social and health care in the COVID-19 pandemic in the Public Hospital of Monforte (Lugo, Spain) and to evaluate the effectiveness of the measures included in this plan.

METHOD

Phenomenological sampling conducted between March 10 and May 15, 2020. Evaluation qualitative assessment by an external quality improvement team of the Galician Health Service (SERGAS), based on the Practicum Direct rapid structured checklist in risk management, organizational management, and evaluation of decision making. As outcome indicators, we assessed the number of hospital admissions, number of PCRs performed, telephone attention to social and health social-healthcare patients, number of hospitalizations avoided and estimation of their direct cost.

RESULTS

After assessing and managing the risks, an information security plan was developed and solutions to minimize complications in our patients derived from this pandemic. An emergency decision making team was created, as well as an employee communication mechanism for employees through standardized documents and documentation channels.

CONCLUSIONS

The adaptation of the Practicum Direct rapid model to the healthcare setting is a useful and easy-to-apply tool that allows us to identify weak points and areas for improvement in our Service and thus to strengthen patient care in all clinical areas, improving the quality of care.

Validation of the RIM Score-COVID in the Spanish SEMI-COVID-19 Registry

The significant impact of COVID-19 worldwide has made it necessary to develop tools to identify patients at high risk of severe disease and death. This work aims to validate the RIM Score-COVID in the SEMI-COVID-19 Registry. The RIM Score-COVID is a simple nomogram with high predictive capacity for in-hospital death due to COVID-19 designed using clinical and analytical parameters of patients diagnosed in the first wave of the pandemic. The nomogram uses five variables measured on arrival to the emergency department (ED): age, sex, oxygen saturation, C-reactive protein level, and neutrophil-to-platelet ratio. Validation was performed in the Spanish SEMI-COVID-19 Registry, which included consecutive patients hospitalized with confirmed COVID-19 in Spain. The cohort was divided into three time periods: T1 from February 1 to June 10, 2020 (first wave), T2 from June 11 to December 31, 2020 (second wave, pre-vaccination period), and T3 from January 1 to December 5, 2021 (vaccination period). The model's accuracy in predicting in-hospital COVID-19 mortality was assessed using the area under the receiver operating characteristics curve (AUROC). Clinical and laboratory data from 22,566 patients were analyzed: 15,976 (70.7%) from T1, 4,233 (18.7%) from T2, and 2,357 from T3 (10.4%). AUROC of the RIM Score-COVID in the entire SEMI-COVID-19 Registry was 0.823 (95%CI 0.819-0.827) and was 0.834 (95%CI 0.830-0.839) in T1, 0.792 (95%CI 0.781-0.803) in T2, and 0.799 (95%CI 0.785-0.813) in T3. The RIM Score-COVID is a simple, easy-to-use method for predicting in-hospital COVID-19 mortality that uses parameters measured in most EDs. This tool showed good predictive ability in successive disease waves.

PARANEOPLASTIC SYNDROMES REVIEW: THE GREAT FORGOTTEN ONES

Paraneoplastic syndromes (PNS) are a group of disorders that can affect the oncologic patient, and which are not directly attributable to tumour invasion, tumour compression or metastasis. In fact, they are due to tumour secretion of functional hormones or peptides or are related to immune cross-reactivity with the host tissue. These syndromes are called paraneoplastic because the components that cause them do not derive from the organ or tissue of origin, but from the neoplasm suffered by the patient. It is estimated that 10-15% of people with cancer suffer from a PNS.(1) PNS is the second direct cause of death (27% of cases) in cancer patients, after cancer itself. Consequently, it is of remarkable importance to recognize and treat SPNs specifically.(2) In view of the above, the aim of this article is to review the state of the art in neurological, haematological, endocrine, and dermatological paraneoplastic syndromes. It is a review in which the most relevant PNS and their symptomatology are described, inquiring into their diagnosis and treatment.

[Design and validation of an instrument about quality of the advance care planning for professionals]

OBJECTIVE

To develop a questionnaire aimed to measure the quality of the advance care planning process in healthcare professionals and to assess its psychometric quality.

METHOD

Instrumental questionnaire validation study.

SCOPE

primary care centers and outpatients clinics from general hospitals in Ferrol, Ourense, Monforte-Lugo and Health Area V of the Health Service of Asturias.

PARTICIPANTS

physicians and nurses. Phases: (1) design of the first version of the questionnaire using the Delphi technique; (2) construction of the second version of 21 items, after judges' agreement and Kendall's W test; (3) pilot study: internal consistency using Cronbach's alpha and omega coefficient, retest-test by Pearson's correlation coefficient; (4) validation: Barlett's spherity test and Kaiser-Meyer-Olkin measurement, exploratory factor analysis with varimax rotation and study of the dimensions of the questionnaire (number, CCI and correlation), internal consistency using Cronbach's alpha.

RESULTS

Pilot study with 28 professionals. Reliability ɷ=0.917, α=0.841, and test-retest correlation coefficient of 0.785 (95% confidence interval: 0.587-0.894; p<0.001). Validation of the questionnaire (21 items) in 204 professionals. Ítem analysis and exploratory factor analysis (Barlett's test [χ²=1298,789] and KMO=0.808; p<0.001) yielded a five-factor model explaining 64.377% of the total variance, with 18 items grouped into 5 dimensions (information, preferences, behavioral intention, training and communication). Cronbach's alpha of the global questionnaire was 0.841.

CONCLUSIONS

The ProPAD-pro questionnaire has showed to be a valid and reliable instrument to assess the quality of the advance care planning process.

Post-COVID-19 Syndrome (PC19S): Chronic Reactive Endotheliitis and Disseminated Vascular Disease

N/a.

Should we consider a 'fourth 90' for tuberculosis?

The international community has committed to end the tuberculosis (TB) epidemic by 2030. To facilitate the meeting of the global incidence and mortality indicators set by the World Health Organization's End TB Strategy, the Stop TB Partnership launched the three 90-(90)-90 diagnostic and treatment targets in 2014. In this paper, we argue that a 'fourth 90'-Ensuring that 90% of all people successfully completing treatment for TB can have a good health-related quality of life'-should be considered. Many individuals who successfully complete anti-TB treatment are burdened with lifelong comorbidities-human immunodeficiency virus (HIV) and diabetes mellitus, obstructive and restrictive lung disease, involving lung destruction, cavitation, fibrosis and bronchiectasis, that either pre-existed or developed as a result of TB (e.g., chronic pulmonary aspergillosis), permanent disabilities such as hearing loss resulting from second-line anti-TB drugs, and mental health disorders. These need to be identified during TB treatment and appropriate care and support provided after anti-TB treatment is successfully completed. A 'fourth 90' has also been proposed for the UNAIDS 90-90-90 targets similar in scope to what is being suggested here for TB. Adoption by both HIV and TB control programmes would highlight the current focus on integrated person- and family-centred services.

Successfully treated but not fit for purpose: paying attention to chronic lung impairment after TB treatment

In 2013, 86% of patients with newly diagnosed tuberculosis (TB) successfully completed treatment and were discharged from care. However, long-term studies in industrialised and resource-poor countries all point to a higher risk of death in TB survivors than in the general population. The likely explanation is chronic restrictive and obstructive lung disease consequent to TB. We call for better linkages between TB control programmes and respiratory medicine services, a better understanding of the burden of respiratory disability at the end of anti-tuberculosis treatment, and political, programmatic, clinical and research action to improve the quality of life of affected patients.

[Benzodiazepine use in a sample of patients on a treatment program with opiate derivatives (PTDO)]

OBJECTIVES

Benzodiazepines (BZ) are widely prescribed drugs, but their use is controversial in patients who present a disorder caused by substance use/abuse, due to the risk of tolerance and abuse/dependence. The purpose of this work is to determine the levels of BZ use in patients treated with methadone and to compare them with findings from the current literature.

METHODOLOGY

a sample of 43 patients was selected; inclusion criterion was being on the PTDO (treatment program with opiate derivatives) at the UAD (Drug-dependence unit) in Monforte de Lemos (Lugo-Spain). Demographic and use variables were analyzed. Data collection and subsequent analysis were carried out using the statistical program SPSS 12.0.

RESULTS

46.5% of the patients take BZ, and of these, 60% are over age 45. The most widely used of these is alprazolam (p<0.001), and 70% take just one active ingredient. The main prescriber is the general practitioner, and the most frequent indication is insomnia.

DISCUSSION AND CONCLUSIONS

BZ-use data and their relationship to time spent on methadone are similar to those of other published studies. Despite the recommendation to use long half-life BZ in patients with substance abuse disorders, it is striking that in the case studied here the most widely prescribed type is alprazolam.

Two-stage treatment with preoperative endoscopic retrograde cholangiopancreatography (ERCP) compared with single-stage treatment with intraoperative ERCP for patients with symptomatic cholelithiasis with possible choledocholithiasis

BACKGROUND AND STUDY AIMS

An ideal treatment for choledocholithiasis in the laparoscopic era has not been established. The objective of this study was to elucidate whether a treatment strategy of performing intraoperative endoscopic retrograde cholangiopancreatography (ERCP) during laparascopic cholecystectomy (when choledocholithiasis is confirmed by intraoperative cholangiography) is better for patients with suspected common bile duct stones than the current strategy (preoperative ERCP followed by laparoscopic cholecystectomy).

PATIENTS AND METHODS

This was a prospective randomized study to evaluate which of these two approaches was most benefit- and cost-effective for patients with intermediate risk of choledocholithiasis. Patients underwent either preoperative ERCP followed by a laparoscopic cholecystectomy a few weeks later (the "preoperative ERCP" group) or intraoperative ERCP (the "intraoperative ERCP" group). Intraoperative ERCP was performed using the rendezvous technique.

RESULTS

There were 64 patients in the preoperative ERCP group and 59 patients in the intraoperative ERCP group. The demographic and clinical characteristics of the two groups were similar, except that the bilirubin and gamma-glutamyl transferase (GGT) levels and the number of patients treated on an inpatient basis were higher in the preoperative ERCP group. Success rates were similar (96.6 % in the preoperative ERCP group vs. 90.2 % in the intraoperative ERCP group in the per-protocol study). Total morbidity, post-ERCP morbidity, and post-ERCP acute pancreatitis rates were higher in the preoperative ERCP group, but there were no differences between the two groups in the frequency of residual common bile duct stones, the conversion rate to open cholecystectomy, or surgical morbidity. The length of hospital stay and costs were lower in the intraoperative ERCP group despite the longer surgical times in this group. Univariate analysis did not find any relationship between morbidity and total bilirubin or GGT. Logistic regression analysis confirmed that morbidity was related only to the treatment group and the time spent in the operating room: the relative risk (RR) was 4.37 for morbidity and 1.015 for the time spent in the operating room); the RR for papillotomy was 5.49.

CONCLUSIONS

Both treatment approaches were equally effective but the intraoperative ERCP group had less morbidity, a shorter hospital stay, and reduced costs. The lower morbidity in the intraoperative ERCP group resulted from the lower rate of papillotomy and lower rates of post-ERCP pancreatitis and cholecystitis. Total morbidity was principally related to the type of treatment approach used.

Detecting photoinduced electron transfer processes in the SERS spectrum of salicylate anion adsorbed on silver nanoparticles

The surface-enhanced Raman scattering (SERS) of salicylic acid (S) adsorbed on a silver sol in H(2)O and D(2)O has been investigated. At pH 5 or greater, the adsorbed species is the salicylate anion (2-hydroxybenzoate anion) (S(-)), which links to the metal nanoparticle (Ag(n)) through the carboxylate group (S(-)-Ag(n)). We demonstrate that the selective enhancement of the bands is due mainly to a resonant electron or charge transfer process (ET or CT) from the metallic nanoparticle to the adsorbate, yielding the transient formation of the respective radical dianion (S.(2-)-Ag(n) (+)). It is found that the enhanced bands, and especially mode 8a;nu(ring), are related to the differences between the equilibrium structures of the adsorbate in its ground (S(-)) and CT-excited states (S.(2-)).

Role of heme oxygenase/carbon monoxide pathway on the vascular response to noradrenaline in portal hypertensive rats

1. Portal hypertension (PH), a major syndrome in cirrhosis, producing hyperdynamic splanchnic circulation and hyperaemia. In order to elucidate the contribution of heme oxygenase to the vascular hyporeactivity, we assessed the activity of heme oxygenase-1 (HO-1), measured the in vivo pressure response to noradrenaline (NA) and investigated the effects of blocking the carbon monoxide (CO) and nitric oxide (NO) pathways in a prehepatic model of PH in rats. 2. Portal hypertension was induced by partial portal vein ligation (PPVL). Noradrenaline was injected intravenously. Liver, spleen and mesentery homogenates were prepared for measurement of HO-1 activity and expression. Four groups of rats were used: (i) a sham group; (ii) a PPVL group; (iii) a sham group pretreated with Zn-protoporphyrin IX (ZnPPIX); and (iv) a PPVL group pretreated with ZnPPIX. Each group was studied before and after treatment with the NO synthase inhibitor N(G)-nitro-L-arginine methyl ester (L-NAME). 3. For basal pressures and the pressure response to NA, inhibition of CO and NO pathways by ZnPPIX and L-NAME, respectively, produced an increase in mean arterial pressure (MAP) in sham-operated and in PH rats. Similarly, when both inhibitors were used together in either sham or PPVL rats, a greater increase in MAP was observed. 4. These results, together with the increased HO-1 activity and expression only in the PH group, have led us to suggest that the heme oxygenase/CO pathway is involved in the vascular response to NA in PH rats.

Adsorption of mercaptoacetic acid on a colloidal silver surface as investigated by Raman spectroscopy

The vibration nu(SH) has never been observed in the surface-enhanced Raman scattering of mercaptoacetic acid recorded in a wide range of pH. This behavior enables us to deduce that the -SH group is deprotonated and links to the metal forming an Ag-S bond as 1-alkanethiols do. On the contrary, the carboxylic or carboxylate groups do not link to the metal and the carboxylic group is preserved even at pH values under which it should be deprotonated. This fact enables the stabilization of the adsorbed monolayer by removing the electrostatic repulsions between -COO(-) groups and by the formation instead of hydrogen bonds between carboxylic groups. Only under rather basic conditions (pH > 8) does the carboxylic groups dissociate, but the nu(s)(OCO) band is neither enhanced nor shifted toward low frequencies.

Vibrational study of the metal-adsorbate interaction of phenylacetic acid and alpha-phenylglycine on silver surfaces

Raman and SERS spectra of phenylacetic acid and alpha-phenylglycine on silver sols have been recorded at several concentrations and pH values. The alpha-phenylglycine has been also studied in D(2)O. The respective vibrational assignments have been proposed and the analysis of the SERS spectra has made it possible to conclude that phenylacetic acid links to the metal through its carboxylate group only, while alpha-phenylglycine links also through its amino group. In both cases the aromatic ring seems to be almost perpendicular to the metal surface. On the other hand, the contribution of the charge transfer (CT) mechanism to the enhancement of the SERS spectra has been calculated as well and it is found to be very important in both molecules. The band most enhanced by this mechanism is that of vibration 8a, mainly in alpha-phenylglycine.

Endoscopic treatment of postoperative fistulas resistant to conservative management using biological fibrin glue

BACKGROUND AND STUDY AIMS

Postoperative fistulae occur frequently in standard surgical practice, but there is no general agreement on how to treat them. We summarize here our experience with endoscopic treatment.

PATIENTS AND METHODS

Postoperative digestive fistulae resistant to conservative treatment, in 15 patients, are retrospectively reviewed. Our series included two internal fistulas: (one rectovesical, and one high-output pleuroesophagic), and 13 external fistulas (one low-output gastrocutaneous, two low-output esophagocutaneous, seven low-output enterocutaneous, and three high-output enterocutaneous). After failure of conservative treatment, the fistulas were endoscopically located and 2 - 4 ml of reconstituted fibrin glue, Tissucol 2.0 at 37 degrees C, was injected through a catheter.

RESULTS

The mean age of the patients was 61.2 years (38 - 86), and 60 % were men. Of the fistulas, 26.6 % were of the high-output type. The mean healing time was 16 days (5 - 40), and a mean of 2.5 sessions per patient were required (1 - 5). Complete sealing of fistulas was achieved in 86.6 % of cases; (87.5 % of the low-output and internal fistulas, and 55 % of the high-output fistulas). After follow-up ranging between 2 months and more than 3 years, only one of the sealed fistulas reopened. No complications were encountered. Overall mortality was 13.3 % (two out of 15), but in only one patient was this related to clinical deterioration because of the persistence of the fistula.

CONCLUSIONS

We think that conservative treatment should not be prolonged beyond 14 days and that endoscopic treatment should be performed at that stage. Endoscopic sealing treatment achieves a very high success rate, without complications and at a lower cost. It could probably reduce the hospital stay, and avoid some unnecessary surgical interventions. Appropriate multicenter randomized trials are needed to confirm these results.

Study of interaction between aspartic acid and silver by surface-enhanced Raman scattering on H(2)O and D(2)O sols

Three different surface-enhanced Raman scattering (SERS) spectra are recorded for aspartic acid on H(2)O silver sols under different concentrations and pH values. The analysis of the results shows that it interacts with the metal surface in its dianionic form in two different ways, depending on the pH and concentration. Moreover, in some cases the fumarate anion is detected, which results from the chemical surface transformation of the aspartate. The N-deuterated aspartic acid adsorbed on the D(2)O silver sols gives rise to only one SERS spectrum as a consequence of the interaction of amino and carboxylate functional groups of the dianion with the metal, independent of the concentration and pD.

Pharmacological knock-down of the presenilin 1 heterodimer by a novel gamma -secretase inhibitor: implications for presenilin biology

Intramembranous cleavage of the beta-amyloid precursor protein by gamma-secretase is the final processing event generating amyloid-beta peptides, which are thought to be causative agents for Alzheimer's disease. Missense mutations in the presenilin genes co-segregate with early-onset Alzheimer's disease, and, recently, a close biochemical linkage between presenilins and the identity of gamma-secretase has been established. Here we describe for the first time that certain potent gamma-secretase inhibitors are able to interfere with the endoproteolytic processing of presenilin 1 (PS1). In addition, we identified a novel gamma-secretase inhibitor, [1S-benzyl-4R-[1-(5-cyclohexyl-2-oxo-2,3-dihydro-1H-benzo[e][1,4]diazepin-3(R,S)-ylcarbamoyl)-S-ethylcarbamoyl]-2R-hydroxy-5-phenyl-pentyl]-carbamic acid tert-butyl ester (CBAP), which not only physically interacts with PS1, but upon chronic treatment produces a "pharmacological knock-down" of PS1 fragments. This indicates that the observed accumulation of full-length PS1 is caused by a direct inhibition of its endoproteolysis. The subsequent use of CBAP as a biological tool to increase full-length PS1 levels in the absence of exogenous PS1 expression has provided evidence that wild-type PS1 endoproteolysis is not required either for PS1/gamma-secretase complex assembly or trafficking. Furthermore, in cell-based systems CBAP does not completely recapitulate PS1 loss-of-function phenotypes. Even though the beta-amyloid precursor protein cleavage and the S3 cleavage of the Notch receptor are inhibited by CBAP, an impairment of Trk receptor maturation was not observed.

N-Arylsulfonylindole derivatives as serotonin 5-HT(6) receptor ligands

A series of N(1)-arylsulfonyltryptamines were found to be potent ligands of the human serotonin 5-HT(6) receptor with the 5-methoxy-1-benzenesulfonyl analogue (19) having the highest affinity. Additionally, it was discovered that a group such as 3-(3-methoxybenzyl)-1,2,4-oxadiazol-5-yl in the 2-position of the indole ring (43) can replace the arylsulfonyl substituent in the 1-position with no loss of affinity. This suggested that the binding conformation of the aminoethyl side chain at this receptor was toward the 4-position of the indole ring and was supported by the fact that the 4-(aminoethyl)indoles (45) also displayed high affinity, as did the conformationally rigid 1,3,4,5-tetrahydrobenz[c,d]indole (49). Molecular modeling showed that 19, 43, and 45 all had low-energy conformers that overlaid well onto 49. Both 19 and 49 had good selectivity over other serotonin receptors tested, with 49 also showing excellent selectivity over all dopamine receptors. In a functional adenylate cyclase stimulation assay, 19 and 49 had no agonist activity, whereas 45 behaved as a partial agonist. Finally, it was shown that 19 had good activity in the 5-HT(2A) centrally mediated mescaline-induced head twitch assay, which implies that it is brain-penetrant.

3-(4-Fluoropiperidin-3-yl)-2-phenylindoles as high affinity, selective, and orally bioavailable h5-HT(2A) receptor antagonists

The development of very high affinity, selective, and bioavailable h5-HT(2A) receptor antagonists is described. By investigation of the optimal position for the basic nitrogen in a series of 2-phenyl-3-piperidylindoles, it was found that with the basic nitrogen at the 3-position of the piperidine it was not necessary to further substitute the piperidine in order to obtain good binding at h5-HT(2A) receptors. This meant the compounds no longer had high affinity at the IKr potassium channel, an issue with previous series of 2-aryl-3-(4-piperidyl)indoles. Improvements could be made to oral bioavailability in this series by reduction of the pK(a) of the basic nitrogen, by adding a fluorine atom to the piperidine ring, leading to 3-(4-fluoropiperidin-3-yl)-2-phenyl-1H-indole (17). Metabolic studies with this compound identified oxidation at the 6-position of the indole as a major route in vitro and in vivo in rats. Blocking this position with a fluorine atom led to 6-fluoro-3-(4-fluoropiperidin-3-yl)-2-phenyl-1H-indole (22), an antagonist with 0.06 nM affinity for h5-HT(2A) receptors, with bioavailability of 80% and half-life of 12 h in rats.

Treatment of left colon neoplasic obstruction by placement of self-expandable stents

INTRODUCTION AND OBJECTIVE

Neoplasic stenoses of the left colon are most frequently caused by primary colon carcinoma, infiltration from an external tumour and great adenomatous polyps. These patients often develop obstruction as their first symptom, leading to emergency surgical procedures in adverse circumstances and without an appropriate intestinal preparation that might prevent primary anastomosis. Therapeutic options for this event, such as Hartmann's resection, subtotal colectomy or anterograde colon lavage are not always possible. In these patients a colostomy is performed that requires future reoperation for reconstruction of the intestinal transit. Transtumoral self-expandable stenting followed by elective surgery might be the best option in these cases, as well as an alternative to surgery in non-operable patients.

PATIENTS AND METHODS

Twenty four patients treated with this procedure in the past four years were divided in two groups. In group 1 (14 patients), the stent was placed as a permanent and palliative measure for the management of the disease. In group 2 (10 patients), the stent was placed temporarily for the management of the intestinal obstruction and latter the patients underwent elective surgery with fully preoperative and extension study and an appropriate preparation of the colon in order to allow reliable primary anastomosis.

RESULTS

There were no hospital mortality nor stent migrations. There was only one complication (perforation caused by the stent) that required emergency surgery, but with any further complications. Failure to place the stent occurred in one patient.

CONCLUSIONS

Self-expandable stents relieve neoplasic colon obstructions and allow to complete the study protocol, followed by elective surgery associated to less morbi-mortality. In patients with advanced or irresectable cancer, they provide a palliative and safe alternative to surgery, with satisfactory results.

Solid-phase synthesis of 2,3-disubstituted indoles: discovery of a novel, high-affinity, selective h5-HT2A antagonist

The application of a novel solid-phase synthesis of 2,3-disubstituted indoles utilizing a carbamate indole linker is described resulting in the identification of the novel, high-affinity, selective h5-HT2A antagonist 19.

2-Aryl tryptamines: selective high-affinity antagonists for the h5-HT2A receptor

A series of 2-aryl tryptamines have been identified as high-affinity h5-HT2A antagonists. Structure-activity relationship studies have shown that h5-HT2A affinity can be attained via modifications to the tryptamine side chain and that selectivity over h5-HT2C and hD2 receptors can be controlled by suitable C-2 aryl groups.

L-685,458, an aspartyl protease transition state mimic, is a potent inhibitor of amyloid beta-protein precursor gamma-secretase activity

Progressive cerebral amyloid beta-protein (A beta) deposition is believed to play a central role in the pathogenesis of Alzheimer's disease (AD). Elevated levels of A beta(42) peptide formation have been linked to early-onset familial AD-causing gene mutations in the amyloid beta-protein precursor (A beta PP) and the presenilins. Sequential cleavage of A beta PP by the beta- and gamma-secretases generates the N- and C-termini of the A beta peptide, making both the beta- and gamma-secretase enzymes potential therapeutic targets for AD. The identity of the A beta PP gamma-secretase and the mechanism by which the C-termini of A beta are formed remain uncertain, although it has been suggested that the presenilins themselves are novel intramembrane-cleaving gamma-secretases of the aspartyl protease class [Wolfe, M. S., Xia, W., Ostaszewski, B. L., Diehl, T. S., Kimberly, W. T., and Selkoe, D. J. (1999) Nature 398, 513-517]. In this study we report the identification of L-685,458 as a structurally novel inhibitor of A beta PP gamma-secretase activity, with a similar potency for inhibition of A beta(42) and A beta(40) peptides. This compound contains an hydroxyethylene dipeptide isostere which suggests that it could function as a transition state analogue mimic of an aspartyl protease. The preferred stereochemistry of the hydroxyethylene dipeptide isostere was found to be the opposite to that required for inhibition of the HIV-1 aspartyl protease, a factor which may contribute to the observed specificity of this compound. Specific and potent inhibitors of A beta PP gamma-secretase activity such as L-685,458 will enable important advances toward the identification and elucidation of the mechanism of action of this enigmatic protease.

Neural networks with a continuous squashing function in the output are universal approximators

In 1989 Hornik as well as Funahashi established that multilayer feedforward networks without the squashing function in the output layer are universal approximators. This result has been often used improperly because it has been applied to multilayer feedforward networks with the squashing function in the output layer. In this paper, we will prove that also this kind of neural networks are universal approximators, i.e. they are capable of approximating any Borel measurable function from one finite dimensional space into (0,1)" to any desired degree of accuracy, provided sufficiently many hidden units are available.

Photoactivated gamma-secretase inhibitors directed to the active site covalently label presenilin 1

Cleavage of amyloid precursor protein (APP) by the beta- and gamma-secretases generates the amino and carboxy termini, respectively, of the A beta amyloidogenic peptides A beta40 and A beta42--the major constituents of the amyloid plaques in the brain parenchyma of Alzheimer's disease patients. There is evidence that the polytopic membrane-spanning proteins, presenilin 1 and 2 (PS1 and PS2), are important determinants of gamma-secretase activity: mutations in PS1 and PS2 that are associated with early-onset familial Alzheimer's disease increase the production of A beta42 (refs 4-6), the more amyloidogenic peptide; gamma-secretase activity is reduced in neuronal cultures derived from PS1-deficient mouse embryos; and directed mutagenesis of two conserved aspartates in transmembrane segments of PS1 inactivates the ability of gamma-secretase to catalyse processing of APP within its transmembrane domain. It is unknown, however, whether PS1 (which has little or no homology to any known aspartyl protease) is itself a transmembrane aspartyl protease or a gamma-secretase cofactor, or helps to colocalize gamma-secretase and APP. Here we report photoaffinity labelling of PS1 (and PS2) by potent gamma-secretase inhibitors that were designed to function as transition state analogue inhibitors directed to the active site of an aspartyl protease. This observation indicates that PS1 (and PS2) may contain the active site of gamma-secretase. Interestingly, the intact, single-chain form of wild-type PS1 is not labelled by an active-site-directed photoaffinity probe, suggesting that intact wild-type PS1 may be an aspartyl protease zymogen.

Sedative but not anxiolytic properties of benzodiazepines are mediated by the GABA(A) receptor alpha1 subtype

Inhibitory neurotransmission in the brain is largely mediated by GABA(A) receptors. Potentiation of GABA receptor activation through an allosteric benzodiazepine (BZ) site produces the sedative, anxiolytic, muscle relaxant, anticonvulsant and cognition-impairing effects of clinically used BZs such as diazepam. We created genetically modified mice (alpha1 H101R) with a diazepam-insensitive alpha1 subtype and a selective BZ site ligand, L-838,417, to explore GABA(A) receptor subtypes mediating specific physiological effects. These two complimentary approaches revealed that the alpha1 subtype mediated the sedative, but not the anxiolytic effects of benzodiazepines. This finding suggests ways to improve anxiolytics and to develop drugs for other neurological disorders based on their specificity for GABA(A) receptor subtypes in distinct neuronal circuits.

[Esophageal perforation and postoperative fistulae of the upper digestive tract treated endoscopically with the application of Tissucol]

We present three patients with serious gastro-esophageal complications which were treated with Tissucol. The first patient developed a rare postoperative oesophago-pleural fistula. The second suffered a traumatic esophageal perforation (possibly iatrogenic) that was discovered at the end of the removal procedure of an alimentary bolus impacted in the distal esophagus. Attempts to close the high output oesophago-pleural fistula with standard treatment were unsuccessful. It was closed with Tissucol at the third attempt, in conjunction with oesophago-jejunal stenosis by means of endoscopic dilatation. In the second patient, early Tissucol application after detection of pneumomediastinum was an effective complementary treatment to the conservative approach and rapidly closed the perforation. The third patient developed a low debit postoperative gastro-cutaneous fistula that did not resolve with conservative treatment. It was closed with only one session of Tissucol sealing. We consider that the endoscopic application of fibrin glue should become the first step in the conservative treatment of small esophageal perforations or postoperative esophageal pleural fistulae, especially in cases of high output fistulae. The success of this technique depends on the localization and selective catheterization of the fistula and on brushing the fistular opening. Total resolution of any distal stenosis is necessary to prevent reopening of the fistula.

3-[3-(Piperidin-1-yl)propyl]indoles as highly selective h5-HT(1D) receptor agonists

Several 5-HT(1D/1B) receptor agonists are now entering the marketplace as treatments for migraine. This paper describes the development of selective h5-HT(1D) receptor agonists as potential antimigraine agents which may produce fewer side effects. A series of 3-[3-(piperidin-1-yl)propyl]indoles has been synthesized which has led to the identification of 80 (L-772,405), a high-affinity h5-HT(1D) receptor full agonist having 170-fold selectivity for h5-HT(1D) receptors over h5-HT(1B) receptors. L-772,405 also shows very good selectivity over a range of other serotonin and nonserotonin receptors and has excellent bioavailability following subcutaneous administration in rats. It therefore constitutes a valuable tool to delineate the role of h5-HT(1D) receptors in migraine. Molecular modeling and physical properties have been utilized to postulate the binding conformation of these compounds in the receptor cavity.

[Treatment of inoperable malignant gastric stenosis with self-expanding prosthesis]

We report two patients with inoperable malignant stenosis of gastric antrum who were treated with endoscopic placement of a 22 mm Wallstent metallic prosthesis. In one patient, the endoscope was introduced simultaneously with the prosthesis. Different types of pincers were introduced through the endoscope's canal, which aided the movement and placement of the prosthesis. In the other patient, to broaden the stenosis a pediatric endoscope was introduced with a guide inside the canal, which was held straight externally and which facilitated the positioning of the prosthesis. There were no complications and the patients were discharged after 48 hours able to follow a normal oral diet. Both patients are still living, six and four months respectively after the procedure.

Parallel synthesis of 3-aryloxy-2-propanolamines and evaluation as dual affinity 5-HT(1A) and 5-HT re-uptake ligands

A solution phase synthesis for the preparation of 3-aryloxy-2-propanolamine libraries has been developed. This resulted in the identification of 5 as a ligand with dual affinity for 5-HT1A and serotonin reuptake receptors which shows excellent pharmacokinetic parameters.

Central benzodiazepine involvement in clonidine cardiovascular actions

It is well known that the GABAergic and noradrenergic systems play an important role in blood pressure and heart rate regulation. Benzodiazepines and beta-carbolines, respectively, increase or decrease the probability of chloride-channel opening induced by GABA. The aim of this study was to determine, in conscious rats, the interaction existing between the central alpha2-adrenoceptor stimulation induced by clonidine and the facilitation or impairment of benzodiazepine receptor activity through the administration of either diazepam, a benzodiazepine receptor agonist, or methyl 6,7-dimethoxy-4-ethyl-beta-carboline-3-carboxylate (DMCM), an inverse benzodiazepine agonist. Clonidine (5-10 microg, intracerebroventricularly) reduced heart rate and increased mean blood pressure by activation of central alpha2-adrenoceptors. Diazepam (2 mg/kg, intravenously (i.v.)) induced an increase in heart rate, while DMCM (0.3 mg/kg, i.v.) elicited a bradycardic effect. The bradycardic effects induced by both clonidine and DMCM were antagonized by the prior administration of methylatropine (1.5 mg/kg, i.v.). DMCM (0.3 mg/kg, i.v.) prevented the clonidine effects on heart rate and mean blood pressure, while diazepam (2 mg/kg, i.v.) failed to modify these effects. Our results suggest that the bradycardic effects of clonidine are mediated by a vagal stimulation and are related to the activation of a GABAergic pathway.

2,7-diazabicyclo[3.3.0]octanes as novel h5-HT receptor agonists

The conformational restriction of a (benzylamino)methyl substituted pyrrolidine to form 2,7-diazabicyclo[3.3.0]octanes has led to a series of compounds with high affinity at the h5-HT1D receptor as well as dramatically increased concentrations in the hepatic portal vein following oral administration.

Fluorination of 3-(3-(piperidin-1-yl)propyl)indoles and 3-(3-(piperazin-1-yl)propyl)indoles gives selective human 5-HT1D receptor ligands with improved pharmacokinetic profiles

It has previously been reported that a 3-(3-(piperazin-1-yl)propyl)indole series of 5-HT1D receptor ligands have pharmacokinetic advantages over the corresponding 3-(3-(piperidin-1-yl)propyl)indole series and that the reduced pKa of the piperazines compared to the piperidines may be one possible explanation for these differences. To investigate this proposal we have developed versatile synthetic strategies for the incorporation of fluorine into these ligands, producing novel series of 4-fluoropiperidines, 3-fluoro-4-aminopiperidines, and both piperazine and piperidine derivatives with one or two fluorines in the propyl linker. Ligands were identified which maintained high affinity and selectivity for the 5-HT1D receptor and showed agonist efficacy in vitro. The incorporation of fluorine was found to significantly reduce the pKa of the compounds, and this reduction of basicity was shown to have a dramatic, beneficial influence on oral absorption, although the effect on oral bioavailability could not always be accurately predicted.