Acceptability of short message service (SMS) as a tool for malaria treatment adherence in the Brazilian Amazon: a qualitative study

BACKGROUND

Malaria is one of the leading causes of morbidity worldwide, and patient adherence to prescribed antimalarials is essential for effective treatment.

METHODS

This cross-sectional study, with in-depth telephone interviews, analyzed participants' perceptions of short message service (SMS) in adherence to treatment.

RESULTS

Five thematic categories emerged: decreased forgetfulness, the novelty of the tool, easy-to-understand language, the impact of SMS messages during treatment, and suggestions for improvement and complaints.

CONCLUSIONS

SMS could assist patients in adhering to prescribed antimalarials.

Barriers of Access to Opioid Medicines within the Context of Palliative Care in Latin America: The Perception of Health Professionals

Background: Different sets of barriers have been identified to explain the difficulties in the access and availability of opioid analgesics in palliative care, particularly in low- and middle-income countries, including Latin America. Objective: To validate a structured questionnaire for the access to opioid medicines and to investigate the perception of health professionals regarding access barriers to opioid analgesics in 17 countries of the Latin American Region. Design: Survey to identify the domains and barriers of access to opioid medicines according to health professionals, including physicians, nurses, and pharmacists affiliated to institutions that provide palliative care in Latin America between August 2019 and October 2020. Results: We analyzed responses from 426 health professionals. The median age was 44 years old (ranging from 23 to 73 years) with an average experience in palliative care of 10 years (range: 1-35), 71.8% were women, and 49.8% were affiliated to specialized health care facilities of urban areas (94.6%). The main barriers perceived to be extremely relevant by the respondents were "belief that patients can develop addiction" and "financial limitations of patients" for the patient's domain and the "appropriate education, instruction, and training of professionals" for health professional's domain. Conclusions: It is necessary to develop strategies to strengthen less-developed health systems of the region to review legal frameworks, ensure integrated palliative care systems, and deploy multidisciplinary strategies for sensitizing, training, and raising the awareness of patients, caregivers and, particularly, health professionals regarding appropriate prescription and rational use of opioid analgesics.

Smart Safety Surveillance (3S): Multi-Country Experience of Implementing the 3S Concepts and Principles

Introduction

The Smart Safety Surveillance (3S) concept is based on the understanding that, when faced with competing pharmacovigilance priorities, countries will have to invest judiciously, by focusing on new priority products, sharing work and resources with other countries when possible and building national competence for those activities that cannot be delegated.

Method

The 3S principles were applied to Armenia, Brazil, Ethiopia, India, Peru and Thailand using three priority products: bedaquiline, rotavirus vaccine and tafenoquine. A baseline assessment of pharmacovigilance preparedness was used to identify gaps and establish a work plan. The impact was measured by comparing pre and post 3S-intervention outcomes, which included the number and quality of reports (completeness scores) in the WHO global database of Individual Case Safety Reports, VigiBase, and number of structural indicators met. The implementation period was 9–18 months, ranging from March 2018 (earliest started) until May 2020 (latest).

Result

An increase in adverse drug reaction (ADR) reporting was demonstrated in Armenia (bedaquiline), Brazil (TB and malaria medicines), India (rotavirus vaccine) and Ethiopia (TB medicines). Completeness scores were above 0.5 at baseline in all countries, and reports improved in quality for Brazil (TB), Peru (malaria), Thailand (malaria) and India (immunization). The number of structural indicators met increased by more than double for Ethiopia. Ethiopia and India demonstrated an increased capacity for signal detection and signal evaluation. Armenia, Brazil, Peru and Thailand showed increased capacity to assess risk management plans following the implementation of 3S principles.

Conclusion

The 3S concept has demonstrated success in different ways across the six countries. Activities focused on three products for a proof of concept of the 3S principles, with the expectation that the project impact will be sustained through strengthened systems, to guide pharmacovigilance activities of other products in the future. It is important to continue monitoring the countries to understand if the gains and successes of the current 3S project are sustainable.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40264-021-01100-z.

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.

Building capacity for active surveillance of vaccine adverse events in the Americas: A hospital-based multi-country network

New vaccines designed to prevent diseases endemic in low and middle-income countries are being introduced without prior utilization in countries with robust vaccine pharmacovigilance systems. Our aim was to build capacity for active surveillance of vaccine adverse events in the Americas. We describe the implementation of a proof-of-concept study for the feasibility of an international collaborative hospital-based active surveillance system for vaccine safety. The study was developed and implemented in 15 sentinel sites located in seven countries of the region of the Americas, under the umbrella of the World Health Organization (WHO) Global Vaccine Safety Initiative. The study evaluated the associations between measles-mumps-rubella vaccines and two well-recognized adverse events: Immune thrombocytopenic purpura (ITP) and aseptic meningitis. The regional network contributed 63 confirmed ITP and 16 confirmed aseptic meningitis eligible cases to the global study, representing, respectively, 33% and 19% of the total cases. To ensure long-term sustainability and usefulness to investigate adverse events following new vaccine introductions in low and middle-income countries, the network needs to be strengthened with additional sites and integrated into national health systems.

Operational lessons learned in conducting a multi-country collaboration for vaccine safety signal verification and hypothesis testing: The global vaccine safety multi country collaboration initiative

Timely and effective evaluation of vaccine safety signals for newly developed vaccines introduced in low and middle- income countries (LMICs) is essential. The study tested the development of a global network of hospital-based sentinel sites for vaccine safety signal verification and hypothesis testing. Twenty-six sentinel sites in sixteen countries across all WHO regions participated, and 65% of the sites were from LMIC. We describe the process for the establishment and operationalization of such a network and the lessons learned in conducting a multi-country collaborative initiative. 24 out of the 26 sites successfully contributed data for the global analysis using standardised tools and procedures. Our study successfully confirmed the well-known risk estimates for the outcomes of interest. The main challenges faced by investigators were lack of adequate information in the medical records for case ascertainment and classification, and access to immunization data. The results suggest that sentinel hospitals intending to participate in vaccine safety studies strengthen their systems for discharge diagnosis coding, medical records and linkage to vaccination data. Our study confirms that a multi-country hospital-based network initiative for vaccine safety monitoring is feasible and demonstrates the validity and utility of large collaborative international studies to monitor the safety of new vaccines introduced in LMICs.

Enhancing global vaccine pharmacovigilance: Proof-of-concept study on aseptic meningitis and immune thrombocytopenic purpura following measles-mumps containing vaccination

New vaccines designed to prevent diseases endemic in low and middle-income countries (LMICs) are now being introduced without prior record of utilization in countries with robust pharmacovigilance systems. To address this deficit, our objective was to demonstrate feasibility of an international hospital-based network for the assessment of potential epidemiological associations between serious and rare adverse events and vaccines in any setting. This was done through a proof-of-concept evaluation of the risk of immune thrombocytopenic purpura (ITP) and aseptic meningitis (AM) following administration of the first dose of measles-mumps-containing vaccines using the self-controlled risk interval method in the primary analysis. The World Health Organization (WHO) selected 26 sentinel sites (49 hospitals) distributed in 16 countries of the six WHO regions. Incidence rate ratios (IRR) of 5.0 (95% CI: 2.5-9.7) for ITP following first dose of measles-containing vaccinations, and of 10.9 (95% CI: 4.2-27.8) for AM following mumps-containing vaccinations were found. The strain-specific analyses showed significantly elevated ITP risk for measles vaccines containing Schwarz (IRR: 20.7; 95% CI: 2.7-157.6), Edmonston-Zagreb (IRR: 11.1; 95% CI: 1.4-90.3), and Enders'Edmonston (IRR: 8.5; 95% CI: 1.9-38.1) strains. A significantly elevated AM risk for vaccines containing the Leningrad-Zagreb mumps strain (IRR: 10.8; 95% CI: 1.3-87.4) was also found. This proof-of-concept study has shown, for the first time, that an international hospital-based network for the investigation of rare vaccine adverse events, using common standardized procedures and with high participation of LMICs, is feasible, can produce reliable results, and has the potential to characterize differences in risk between vaccine strains. The completion of this network by adding large reference hospitals, particularly from tropical countries, and the systematic WHO-led implementation of this approach, should permit the rapid post-marketing evaluation of safety signals for serious and rare adverse events for new and existing vaccines in all settings, including LMICs.

Intraoperative ERCP: What role does it have in the era of laparoscopic cholecystectomy?

In the treatment of patients with symptomatic cholelithiasis and choledocholithiasis (CBDS) detected during intraoperative cholangiography (IOC), or when the preoperative study of a patient at intermediate risk for CBDS cannot be completed due to the lack of imaging techniques required for confirmation, or if they are available and yield contradictory radiological and clinical results, patients can be treated using intraoperative endoscopic retrograde cholangiopancreatography (ERCP) during the laparoscopic treatment or postoperative ERCP if the IOC finds CBDS. The choice of treatment depends on the level of experience and availability of each option at each hospital. Intraoperative ERCP has the advantage of being a single-stage treatment and has a significant success rate, an easy learning curve, low morbidity involving a shorter hospital stay and lower costs than the two-stage treatments (postoperative and preoperative ERCP). Intraoperative ERCP is also a good salvage treatment when preoperative ERCP fails or when total laparoscopic management also fails.

Is outpatient ERCP suitable, feasible, and safe? The experience of a Spanish community hospital

BACKGROUND

We wanted to evaluate the safety of outpatient endoscopic retrograde cholangiopancreatography (ERCP). The follow-up of an ERCP outpatient during a short observation period could be a feasible and safe approach.

METHODS

To evaluate the safety of outpatient ERCP, we assessed the rate of post-ERCP complications found and missed during a 6-h observation period after therapeutic ERCP.

RESULTS

We performed 236 ERCPs on an outpatient basis, with a failure rate of 3.7% but with an overall completion rate for the intended treatment of 90.7%. Seventy-eight percent of the ERCPs were primarily therapeutic. The age of the patients was 63.9 years and 61.9% were females. One hundred seventy-seven (74.5%) patients were discharged from the hospital after the observation period. Thirty-three (14.1%) patients were admitted without further delay due to unexpected ERCP findings or for early detection of complications. Twenty-seven (11.4%) patients had a prolonged hospital stay because of complications during the observation period. Just two patients previously discharged developed later complications: cholangitis and pancreatitis (0.84% of the ERCPs and 7.4% of the overall complications). There were 27 ERCP complications (12.1%). Of the overall complications, 29.6% were diagnosed very early after the procedure and 62.9% were diagnosed during the observation period. 8.9% out of the 12.1% of the ERCP complications were mild to moderate. There was no mortality.

CONCLUSION

Twenty-five (92.6%) of ERCP complications occurred during the first 6 h, making the use of this short observation period safe for an early discharge. The evolution of the patients who developed delayed complications was unremarkable. Whenever outpatient ERCP is feasible, it should be done to help cut costs.

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.

5-(Piperidin-2-yl)- and 5-(homopiperidin-2-yl)-1,4-benzodiazepines: high-affinity, basic ligands for the cholecystokinin-B receptor

The design, synthesis, and biological activity of a series of high-affinity, basic ligands for the cholecystokinin-B receptor are described. The compounds, which incorporate a piperidin-2-yl or a homopiperidin-2-yl group attached to C5 of a benzodiazepine core structure, are substantially more basic (e.g., 9d, pKa = 9.48) than previously reported antagonists based on 5-amino-1,4-benzodiazepines (e.g., 5, pKa = 7.1) and have improved aqueous solubility. In view of their basicity, it would be tempting to speculate that the present series of compounds might be binding to the CCK-B receptor in their protonated form. Compounds such as 9d, e and 10d showed high affinity for this receptor (IC50 < 2.5 nM) and very good selectivity over CCK-A (CCK-A/CCK-B > 2000), even as the racemates. Additionally, a significantly improved in vivo half-life was observed for a selection of compounds compared to the clinical candidate L-365, -260 (1).

Controlled modification of acidity in cholecystokinin B receptor antagonists: N-(1,4-benzodiazepin-3-yl)-N'-[3-(tetrazol-5-ylamino) phenyl]ureas

The design, synthesis, and biological activity of a novel series of CCK-B receptor antagonists (1) which incorporate a tetrazol-5-ylamino functionality attached to the phenyl ring of the arylurea moiety of L-365,260 are described. In these compounds, the acidity of the tetrazole was gradually modified by utilization of simple conformational constraints, and X-ray crystallographic data were obtained to support the conformational depenence of the pK(a) of the aminotetrazoles. Compounds to emerge from the present work such as 1f and 2c,d are among the highest affinity and, in the case of 1f, most selective (CCK-A/CCK-B, 37 000) antagonists so far reported for this receptor. The C(5)-cyclohexyl compound 2c (L-736,380) dose-dependently inhibited gastric acid secretion in anesthetized rats (ID(50), 0.064 mg/kg) and ex vivo binding of [(125)I]CCK-8S in BKTO mice brain membranes (ED(50), 1.7 mg/kg) and is one of the most potent acidic CCK-B receptor antagonists yet described.

Quantitative modifications induced by angiotensin II on rat bile secretion

Angiotensin II (ANG II) effects on bile secretion were studied in the rat. ANG II (0.1 microgram/kg) was injected into the jugular vein every 30 min and bile samples of 30 min were collected for 120 min. Blood arterial and portal venous pressures were simultaneously recorded before and after the administration of ANG II. Results showed that ANG II decreased bile flow and the excretion of sodium, potassium, chloride and bile acids whereas it increased pH, bile osmolality and the excretion rate of bicarbonate and calcium. ANG II also led to a rapid increase in mean arterial pressure as well as portal venous pressure which reverted to control values within 1 min. The present results suggest that ANG II may modulate bile flow and the excretion rate of the different biliary constituents. We have previously investigated atrial natriuretic factor effects on bile secretion and although the atrial factor antagonizes most of ANG II biological actions, unexpectedly, ANG II effects on bile secretion were not opposite to those of atrial natriuretic peptide. The modifications induced by ANG II on bile secretion may play an important role in pathophysiological conditions such as hypertensive states with increased ANG II circulating levels.

Synthesis and biological activity of 3-[2-(dimethylamino)ethyl]-5-[(1,1-dioxo-5-methyl-1,2,5-thiadiazolidin- 2-yl)-methyl]-1H-indole and analogues: agonists for the 5-HT1D receptor

A novel series of 5-(1,1-dioxo-1,2,5-thiadiazolidin-2-yl)tryptamines was designed, synthesized, and evaluated as 5-HT1D receptor agonists. Compounds such as 8d,f,k were identified which had comparable affinity, potency, and receptor selectivity to that of the antimigraine drug sumatriptan. Both 8d,k were found to be well absorbed in the rat with oral bioavailabilities of 66% and 62%, respectively. Additionally, 8d was found to be selective over other non-serotonergic receptors and exhibited relatively low central nervous system penetration.

Synthesis and serotonergic activity of 5-(oxadiazolyl)tryptamines: potent agonists for 5-HT1D receptors

The synthesis and 5-HT1D receptor activity of a novel series of 5-(oxadiazolyl)tryptamines is described. Modifications of the oxadiazole 3-substituent, length of the linking chain (n), and the amine substituents are explored and reveal a large binding pocket in the 5-HT1D receptor domain. Oxadiazole substituents such as benzyl are accommodated without loss of agonist potency or efficacy. The incorporation of polar functionality on a phenyl or benzyl spacer group results in a 10-fold increase in affinity and functional potency. Optimal 5-HT1D activity is observed when the heterocycle is conjugated with the indole and the benzyl sulfonamides 20t and 20u represent some of the most potent 5-HT1D agonists known. Replacement of O for S in the heterocycle leads to a further increase in potency. Deletion of oxadiazole N-2 does not reduce activity, suggesting the requirement for only one H-bond acceptor in this location. The selectivity of these compounds for 5-HT1D receptors over other serotonergic receptors is discussed. Sulfonamide 20t shows > or = 1000-fold selectivity for 5-HT1D over 5-HT2, 5-HT1C, and 5-HT3 receptors and 10-fold selectivity with respect to 5-HT1A receptors. The functional activity of this series of compounds is studied and demonstrates high 5-HT1D receptor potency and efficacy comparable to that of 5-HT.

Neovascular glaucoma after helium ion irradiation for uveal melanoma

Neovascular glaucoma developed in 22 of 169 uveal melanoma patients treated with helium ion irradiation. Most patients had large melanomas; no eyes containing small melanomas developed anterior segment neovascularization. The mean onset of glaucoma was 14.1 months (range, 7-31 months). The incidence of anterior segment neovascularization increased with radiation dosage; there was an approximately three-fold increase at 80 GyE versus 60 GyE of helium ion radiation (23% vs. 8.5%) (P less than 0.05). Neovascular glaucoma occurred more commonly in larger tumors; the incidence was not affected by tumor location, presence of subretinal fluid, nor rate of tumor regression. Fifty-three percent of patients had some response with intraocular pressures of 21 mmHg or less to a combination of antiglaucoma treatments.