Post-intensive care syndrome one month after discharge in surviving critically ill COVID-19 patients.

OBJECTIVES: Incidence of post-intensive care syndrome at one month after hospital discharge in surviving critically ill COVID 19 patients and to identify associated factors. DESIGN: Prospective cohort study. SETTING: Two multipurpose critical care units of the Araba University Hospital. Patients admitted to critical care units for severe acute respiratory failure secondary to COVID 19. INTERVENTION: None. VARIABLES OF INTEREST: Demographic variables, length of stay, Charlson index, APACHE II, SOFA, days of mechanical ventilation, tracheotomy, delirium, tetraparesis of the critical patient, EuroQol 5D5L, Minimental Test. RESULTS: A deterioration in the EuroQol health index (HI) from 90.9±16.9 to 70.9±24.7 (p<0.001) was observed. The impairment of the five EuroQol domains is: mobility (46.1%), usual activities (44.7%), discomfort/pain (30.7%), psychological domain (27.3%) and self-care (20.3%). The 61.5% suffer a significant decrease in their health index. Multivariate analysis by logistic regression shows us that delirium (OR=3.01; 95%CI: 1.01-8.9; p=0.047) and tracheostomy (OR=2.37; 95%CI: 1.09-5.14; p=0.029) show association with drop in EuroQoL 5D5L SI. The area under the ROC curve of the model is 67.3%, with a confidence interval between 58% and 76%. The model is calibrated using the Hosmer-Lemeshow test (χ2=0.468; p=0.792). Only 1.2% of patients showed a score ≤ 24, clearly pathological, on the Folstein's Minimental Test. CONCLUSIONS: Delirium and need for tracheostomy are associated with post-intensive care syndrome assessed by EuroQol 5D5L.

[Post-intensive care syndrome one month after hospital discharge of critical patients surviving COVID 19.] / Síndrome post-cuidados intensivos al mes del alta hospitalaria de pacientes críticos supervivientes a COVID 19.

OBJECTIVES: incidence of post-intensive care syndrome at one month after hospital discharge in surviving critically ill COVID 19 patients and to identify associated factors. DESIGN: prospective cohort study. SETTING: two multipurpose critical care units of the Araba University Hospital.Patients admitted to critical care units for severe acute respiratory failure secondary to COVID 19. INTERVENTION: none. VARIABLES OF INTEREST: demographic variables, length of stay, Charlson index, APACHE II, SOFA, days of mechanical ventilation, tracheotomy, delirium, tetraparesis of the critical patient, EuroQol 5D5L, Minimental Test. RESULTS: a deterioration in the EuroQol health index (HI) from 90.9 ± 16.9 to 70.9 ± 24.7 (p < 0.001) was observed. The impairment of the five EuroQol domains is: mobility (46.1%), usual activities (44.7%), discomfort/pain (30.7%), psychological domain (27.3%) and self-care (20.3%). The 61.5% suffer a significant decrease in their health index. Multivariate analysis by logistic regression shows us that delirium (OR= 3.01; 95%CI: 1.01-8.9; p= 0.047) and tracheostomy (OR= 2.37; 95%CI: 1.09-5.14; p= 0.029) show association with drop in EuroQoL 5D5L SI. The area under the ROC curve of the model is 67.3%, with a confidence interval between 58% and 76%. The model is calibrated using the Hosmer-Lemeshow test:(χ2=0.468; p=0.792). Only 1.2% of patients showed a score ≤ 24, clearly pathological, on the Folstein's Minimental Test. CONCLUSIONS: delirium and need for tracheostomy are associated with post-intensive care syndrome assessed by EuroQol 5D5L.

[Predictive models of gestational diabetes, a new prediction mode]. / Modelos predictivos de diabetes gestacional, un nuevo modelo de predicción.

OBJECTIVES: Recognized the value of gestational diabetes (GD) as a health problem, our aim in this work has been to analyze the diagnostic performance of the different today's existing criteria (GEDE, O'Sullivan and Carpenter) after the overload of 100 g of glucose and revise how to increase its efficiency. MATERIALS AND METHODS: We carried out a description of all the variables. In the analytical phase of the work, we used Pearson's Chi square to see if there were differences in the percentage of cases collected in each health center and the proportions contrast test to study the differences between the experimental prevalence. We completed binary logistic regression models using as result variable having or not having gestational diabetes (yes/no) and as predictors the four measurements of the curve with 100 g of glucose overload. To decide which model was better, the stepwise backward-forward analysis and the surface of the ROC curve generated by each of them were considered. RESULTS: We obtained a sample of 170 pregnant women from six different Primary Care Area of Seville health centers who had shown a positive O'Sullivan test with a median age of 35 years. There were significant differences in the prevalence proportions according to the criteria used: GEDE/O'Sullivan p < 0.001; GEDE/Carpenter p < 0.001. Logistic models with three and four predictor variables were equal in discriminatory diagnostic capacity when the GEDE criteria were used (area under the ROC curve = 0.96, 95% CI: 0.93-0.98). The back-forward stepwise analysis stayed with the three-variable model as the most parsimonious. The same did not occur when applying the other two criteria. CONCLUSIONS: Regarding an observational design, we state that there are significant differences in the prevalence proportions observed according to the criteria applied (p < 0.001) and we can also support that using the GEDE criteria, the taking of the third hour could be dispensed with, based on Bayesian criteria and the application of the ROC curve analysis.

Dyslipidaemia and other cardiovascular risk factors in relation to manifest cardiovascular disease in patients with chronic obstructive pulmonary disease in the Canary Islands. / Relación entre la dislipidemia y otros factores de riesgo cardiovasculares conocidos con la presencia de enfermedad cardiovascular en pacientes con enfermedad pulmonar obstructiva crónica de las Islas Canarias.

INTRODUCTION: Cardiovascular disease has a negative impact on the vital prognosis of patients with chronic obstructive pulmonary disease (COPD), where dyslipidaemia (DLP) and arterial hypertension (AHT) are considered the most prevalent risk factors. The objective of this study was 1) to assess the relationship between diagnosed DLP and cardiovascular disease in COPD patients and compare it with other known cardiovascular risk factors and 2) to determine the relationship between the different cardiovascular comorbidities and the severity groups according to the GOLD 2017 classification. METHODS: A cross-sectional, observational study was performed in 454 outpatients with COPD during their follow up. We calculated the prevalence of each of the cardiovascular comorbidities and the probability of each of the cardiovascular risk factors to occur jointly with a vascular disease (RRij). RESULTS: A total of 66.7% of the patients had DLP, whereby DLP was related to cerebrovascular accidents (CVA) (RRij 1.36, P=.0054), chronic kidney disease (CKD) (RRij 1.34, P=.00023), and peripheral arterial disease (PAD) (RRij 1.38, P=.00015). AHT was mostly related to CVA (RRij 1.41, P=.0014) and CKD (RRij 1.42, P<.0001). Type 2 diabetes mellitus (T2DM) correlated with PAD (RRij 1.90, P=.0001), heart failure (HF) (RRij 1,74, P=.0002), and CKD (RRij 1.76, P<.0001), and obesity was associated with HF (RRij 1.60, P=.0009) and CKD (RRij 1.54, P=.0001). CONCLUSION: DLP was related to CVA, CKD, and PAD. AHT and T2DM are the conditions that mostly relate to HF and CVA.

Registros enfermeros, medidas de prevención e incidencia de úlceras por presión en una Unidad de Cuidados Intensivos / Nursing records, prevention measures and incidence of pressure ulcers in an Intensive Care Unit

Objetivos: Determinar la incidencia y categoría más incidente de úlceras por presión (UPP). Conocer las características clínicas de las UPP. Determinar si se realiza un registro adecuado de UPP y las medidas de prevención utilizadas. Método: Estudio observacional, descriptivo y retrospectivo realizado durante el año 2014 en la UCI del Hospital Universitario Araba (HUA)-Txagorritxu. La población de estudio fueron todos los pacientes ingresados con UPP, obtenidos mediante muestreo accidental. Los datos se recogieron a través de los registros informatizados del programa Metavisión de valoración del riesgo, valoración clínica y tratamiento de UPP, los cuales se analizaron con estadística descriptiva y se procesaron mediante el paquete estadístico SPSS, versión 22.0. El estudio fue aprobado por el Comité Ético de Investigaciones Clínicas del HUA. Resultados: La incidencia de pacientes con UPP durante el 2014 alcanzó el 6,78%. La localización de UPP más frecuente fue en la zona sacra y en los talones. La categoría de UPP más incidente fue la II, seguida de la I. De las 98 UPP tratadas en nuestros pacientes, 43 se produjeron fuera del servicio y 55 en la UCI del HUA. La ausencia de registro, en todas las variables descritas sobre las UPP, fue de un 19,01%. Conclusiones: La incidencia de UPP alcanzó un porcentaje inferior a lo existente en la literatura actual. La categoría, localización y características clínicas más frecuentes se asimilan a estudios previos. Existe una elevada tasa de no registro de las características de las UPP declaradas. Se efectuaron unas buenas medidas de prevención de UPP y registro de las mismas

Objectives: The aim of this paper is to determine the incidence and most incident pressure ulcers (PU) category. Establish the main clinical characteristics of these PU. Determine whether there is adequate documentation of PU and of the measures used to prevent them. Method: Observational descriptive and retrospective study during 2014 at Intensive Care Unit (ICU)-University Hospital of Araba. Study sample, all patients suffering from PU at the time of the study by accidental sampling. Computerised records regarding risk assessment, clinical assessment and pressure sore treatment, provided by the 'Metavision' computer programme and descriptive statistics using SPSS version 22.0. Approval from the Ethics Committee for Clinical Research of the University Hospital of Araba was obtained. Results: The incidence of patients suffering from PU during 2014 was 6.78%. The most common locations for PU were the sacral region and the heels: the most incident pressure ulcers category was grade II, followed by grade I. Out of the 98 PU treated in our patients, 43 occurred outside the ICU and 55 in the unit itself. The lack of records, in all the variables described about PU, was 19.10%. Conclusions: The incidence of pressure ulcers was lower than in the current literature. The most frequent category, location and clinical characteristics are comparable to previous studies. There is a high rate of failing to record the characteristics of the PU declared. Good PU prevention measures and recording were carried out

Nursing records, prevention measures and incidence of pressure ulcers in an Intensive Care Unit. / Registros enfermeros, medidas de prevención e incidencia de úlceras por presión en una Unidad de Cuidados Intensivos.

OBJECTIVES: The aim of this paper is to determine the incidence and most incident pressure ulcers (PU) category. Establish the main clinical characteristics of these PU. Determine whether there is adequate documentation of PU and of the measures used to prevent them. METHOD: Observational descriptive and retrospective study during 2014 at Intensive Care Unit (ICU)-University Hospital of Araba. Study sample, all patients suffering from PU at the time of the study by accidental sampling. Computerised records regarding risk assessment, clinical assessment and pressure sore treatment, provided by the 'Metavision' computer programme and descriptive statistics using SPSS version 22.0. Approval from the Ethics Committee for Clinical Research of the University Hospital of Araba was obtained. RESULTS: The incidence of patients suffering from PU during 2014 was 6.78%. The most common locations for PU were the sacral region and the heels: the most incident pressure ulcers category was grade II, followed by grade I. Out of the 98 PU treated in our patients, 43 occurred outside the ICU and 55 in the unit itself. The lack of records, in all the variables described about PU, was 19.10%. CONCLUSIONS: The incidence of pressure ulcers was lower than in the current literature. The most frequent category, location and clinical characteristics are comparable to previous studies. There is a high rate of failing to record the characteristics of the PU declared. Good PU prevention measures and recording were carried out.

Variability in the frequency of rheumatology consultations in patients with rheumatoid arthritis in Spain.

The aim of this work was to assess the variability in the use of health-care resources, based on the number of visits to rheumatology departments by rheumatoid arthritis patients, in Spain, and its association with patient, physician and center characteristics. The sample consisted of patient records of men and women (aged 16 or older), with a clinical diagnosis of RA, who met the American Rheumatism Association 1987 revised criteria and who had been treated in a rheumatology department at a Spanish hospital with at least one visit to a rheumatologist during the two years preceding the date of the study. To analyze which variables were independently associated with the number of consultations, those with a statistically significant result in the bivariate analysis, or which were clinically relevant or deemed confounders, were used in the construction of a linear regression model. The records of 1188 RA patients were studied. The linear regression model explained the 26.67 % of the variability in the number of visits. The number of csDMARDs prescribed, the administration of biological therapy, corticoid prescription, the presence of nursing consultation, mean time to first visit in the department and attended population showed a positive significant association, while the presence of telephone consultation, distance from the hospital to the patient´s residence (≥20 km) and drug monitoring by rheumatology department + primary care physician or by other specialists were negatively associated with the number of consultations. We observed a high variability in the number of visits, which remains partially unexplained even after taking into account individual, physician and center characteristics.

Características clinicoasistenciales y factores asociados a la mortalidad intrahospitalaria por cáncer de pulmón en España / Clinical care characteristics and factors associated with in-hospital mortality for lung cancer in Spain

Background and objective: Lung cancer causes high morbimortality in Spain and is currently experiencing a significant increase in women. The aim of this study was to describe differential clinical and health care characteristics by sex, as well as factors associated with and geographic differences of in-hospital mortality. Material and method: Descriptive study of episodes registered in the National Hospital Discharge Minimum Basic Data Set for admission type and gender in 2005. Two logistic regression models by sex were built in order to explain the individual influence of variables on in-hospital mortality. Using predictive values of the models, standardized mortality rates were calculated to study the variation between Spanish regions. Results: Women presented a lower mean age, smoking habit and in-hospital mortality than men. However, women presented more adenocarcinomas, greater care in high volume centers, more surgery in readmissions and were subjected to chemotherapy more often in new admissions than men. Adenocarcinoma in men and no specific location in women were associated with higher mortality. Smoking habit and lung diagnosis procedures in men, and middle lobe location and bronchoscopy in women were associated with lower mortality. The geographical mortality pattern detected was similar in both sexes only in some regions of Spain. Conclusions: Differential clinical characteristics, health care and overall results appear to exist depending on individuals’ gender. Recognition of these differences are crucial in order to improve the effectiveness and equity of our health care system (AU)

Fundamento y objetivo: El cáncer de pulmón produce elevada morbimortalidad en España, con un notable incremento actual en las mujeres. El objetivo de este estudio es describir, en función del sexo, las características clínicas y asistenciales, así como los factores asociados y las diferencias geográficas de la mortalidad intrahospitalaria en pacientes con cáncer de pulmón. Material y método: Se estudiaron descriptivamente los episodios del conjunto mínimo básico de datos al alta hospitalaria nacional de 2005 por tipo de ingreso y sexo. Se construyeron dos modelos de regresión logística según sexo para explicar la influencia individual de las variables de interés en la mortalidad intrahospitalaria. Mediante las predicciones resultantes se obtuvieron razones de mortalidad estandarizadas para estudiar las comunidades autónomas. Resultados: Las mujeres presentan menor edad media, tabaquismo y mortalidad intrahospitalaria, y en mayor grado adenocarcinomas, atención en centros de alto volumen, cirugía en reingresos y quimioterapia en nuevos ingresos que los varones. El adenocarcinoma en varones y la localización no especificada en mujeres se asocian a mayor mortalidad. El tabaquismo y las pruebas diagnósticas pulmonares en varones, y la localización en lóbulo medio y la broncoscopia en mujeres están asociados a una menor mortalidad. El patrón geográfico de mortalidad detectado es similar en ambos sexos en algunas comunidades, pero difiere en otras. Conclusiones: Existen características diferenciales clínicas, asistenciales y de resultados en función del sexo del paciente. Su reconocimiento es crucial para conseguir mejorar la efectividad y equidad de nuestro sistema sanitario (AU)

[Clinical care characteristics and factors associated with in-hospital mortality for lung cancer in Spain]. / Características clinicoasistenciales y factores asociados a la mortalidad intrahospitalaria por cáncer de pulmón en España.

BACKGROUND AND OBJECTIVE: Lung cancer causes high morbimortality in Spain and is currently experiencing a significant increase in women. The aim of this study was to describe differential clinical and health care characteristics by sex, as well as factors associated with and geographic differences of in-hospital mortality. MATERIAL AND METHOD: Descriptive study of episodes registered in the National Hospital Discharge Minimum Basic Data Set for admission type and gender in 2005. Two logistic regression models by sex were built in order to explain the individual influence of variables on in-hospital mortality. Using predictive values of the models, standardized mortality rates were calculated to study the variation between Spanish regions. RESULTS: Women presented a lower mean age, smoking habit and in-hospital mortality than men. However, women presented more adenocarcinomas, greater care in high volume centers, more surgery in readmissions and were subjected to chemotherapy more often in new admissions than men. Adenocarcinoma in men and no specific location in women were associated with higher mortality. Smoking habit and lung diagnosis procedures in men, and middle lobe location and bronchoscopy in women were associated with lower mortality. The geographical mortality pattern detected was similar in both sexes only in some regions of Spain. CONCLUSIONS: Differential clinical characteristics, health care and overall results appear to exist depending on individuals' gender. Recognition of these differences are crucial in order to improve the effectiveness and equity of our health care system.

Clinical validation of a molecular assay for intra-operative detection of metastases in breast sentinel lymph nodes.

BACKGROUND: In breast cancer patients, the status of the sentinel lymph nodes (SLNs) has been shown to accurately reflect the presence of metastases in the axillary lymph nodes (ALNs). Intra-operative SLN evaluation by frozen section histology may miss positive cases, leading to a second surgery for complete ALN dissection. Permanent section histology itself has tissue sampling limitations and is partially dependent on pathologist expertise. METHODS: A prospective study (N=78) was conducted in our institution to validate a new intra-operative molecular assay, the GeneSearch breast lymph node (BLN) assay. This assay quantifies the expression of mammaglobin and cytokeratin-19 genes using quantitative RT-PCR technology to determine SLN status. Fresh SLN sections (2 mm thick) were analyzed alternatively by BLN assay or post-operative histology (haematoxylin-eosin and immunohistochemistry). The subject was considered positive when histology revealed a focus >0.2 mm. RESULTS: BLN assay results corroborated with histologic results in 75 out of 78 patients for an overall agreement of 96%, a sensitivity of 92%, and a specificity of 97%. The positive and negative predictive values of the BLN assay were of 86% (12/14) and 98% (63/64), respectively. Interestingly, a statistically significant correlation was observed between the metastases' histologic size and both assay markers' expression levels as represented by cycle time to positivity (rho > or = 0.71, all p<0.0001). CONCLUSIONS: The performance of the BLN assay in identifying nodal metastases >0.2 mm was similar to that of permanent section histology, with the added advantages of an objective and rapid output that could be used for intra-operative decision to remove additional ALN.

[Prevention of falls in the elderly and physiotherapy]. / La prévention des chutes chez la personne âgée et la kinésithérapie.

Frequency and dangerousness of falls in elderly people are a public health problem because of its prevalence and its consequences. Because of its high frequency a program designed to avoid the risk of fall and to restore the balance is of importance. Nowadays in Belgium, only the ones belonging to the F-pathology list are reimbursed for the walking functional reeducation. The troubles of walking and balance increasing the risk of falls, are evaluated by different tests like: Tinetti's test (POMA), Time-up-and-go tests. To screen the patient in its physical psychological and environmental sides is mandatory. The physiotherapist is the key to evaluate the patient globally. The main aim is to restore the patient's independence after a fall and to ensure an optimal quality of live. A functional reeducation including the relearning of walking, balance, standing up and proprioception is a must. A preventive way should be more adequate for the patient at risk and the society. A prevention program for fall involving a multidisciplinary team could be the solution of the public health's problem. A lost still remains to be done! In some countries such programs do exist. They inform the elderly about falls' risks and the sometimes tragic consequences. To prevent falls, GP's, ergotherapists, physiotherapists, nurses and social workers have to work together.

Conformationally restricted PACAP27 analogues incorporating type II/II' IBTM beta-turn mimetics. Synthesis, NMR structure determination, and binding affinity.

To probe the importance of a proposed beta-turn within residues S9-R12 of PACAP for recognition by VIP/PACAP receptors, compounds 1 and 2, two conformationally restricted analogues of PACAP27 incorporating respectively (S)- or (R)-IBTM as type II or II' beta-turn dipeptide mimetic at the Y10-S11 position, were synthesized. According to 1H NMR conformational analyses in aqueous solution and 30% TFE, both PACAP27 and the [S-IBTM(10,11)]PACAP27 analogue 1 adopt similar ordered structures. PACAP27 shows an N-terminal disordered region (residues H1-F6) and an alpha-helical conformation within segment T7-L27. For residues S9-R12, our data seem more compatible with a segment of the alpha-helix than with the beta-turn previously proposed for this fragment. In compound 1 the alpha-helix, also spanning T7-L27 residues, appears slightly distorted at the N-terminus relative to the native peptide. Although this distortion could lead to the marked decrease in binding affinity of this compound at the VIP/PACAP receptors, the lack of the Y10 side chain in analogues 1 and 2 could also significantly affect the binding of these compounds.

5-(Tryptophyl)amino-1,3-dioxoperhydropyrido[1,2-c]pyrimidine-based potent and selective CCK(1)receptor antagonists: structure-activity relationship studies on the substituent at N2-position.

To establish structure-activity relationships a new series of analogues of the highly potent and selective CCK(1) receptor antagonist (4aS,5R)-2-benzyl-5-(N-Boc-tryptophyl)amino-1,3-dioxoperhydropyrido[1,2-c]-pyrimidine (1a) modified at N2-position of the central scaffold has been prepared and evaluated as CCK receptor ligands. With this aim the N2-benzyl group has been replaced by methyl, cyclohexyl, aromatic groups, 1-phenylethyl, and 1-carboxy-2-phenylethyl group. Then, substituents with different electronic and steric properties were introduced into different positions of the phenyl group of analogues 19a and 19b. The results of the CCK receptor binding and in vitro functional activity evaluation suggest the importance of the lipophilic character and an appropriate spatial orientation of the moiety linked at the N2-position of the 1,3-dioxoperhydropyrido[1,2-c]pyrimidine template for potent and selective binding and antagonist activity at CCK(1) receptor subtype. The 2-cyclohexyl and (2S)-1-naphthyl derivatives 18a and (2S)-20a have emerged as more potent and selective CCK(1) receptor antagonists than the lead compound 1a. Additionally, the results confirm the (4aS,5R)-stereochemistry at the central bicyclic skeleton as an essential structural requirement for potent binding to this receptor subtype.

beta-Turned dipeptoids as potent and selective CCK(1) receptor antagonists.

To improve our knowledge of the bioactive conformation of CCK(1) antagonists, we previously described that replacement of the alpha-MeTrp residue of dipeptoids with the (2S,5S, 11bR)-2-amino-3-oxohexahydroindolizino[8,7-b]indole-5-carbox ylate (IBTM) skeleton, a probed type II' beta-turn mimetic, led to restricted analogues (2S,5S,11bR,1'S)- and (2S,5S,11bR, 1'R)-2-(benzyloxycarbonyl)amino-5-[1'-benzyl-2'-(carboxy)ethyl]carbam oyl-3-oxo-2,3,5,6,11,11b-hexahydro-1H-indolizino[8,7-b]indole, 1a,b, showing high binding affinity and selectivity for CCK(1) receptors. In this report, we describe the synthesis and binding profile of new analogues of compounds 1 designed to explore the importance of the C-terminal residue and of the type of beta-turn on the receptor binding affinity and selectivity. Structure-affinity relationship studies show that a C-terminal free carboxylic acid and an S configuration of the Phe and betaHph residues are favorable for CCK(1) receptor recognition. Moreover, selectivity for this receptor subtype is critically affected by the beta-turn type. Thus, while compounds 15a and 16a, containing the (2S,5S,11bR)- and (2R,5R, 11bS)-IBTM frameworks, respectively, are both endowed with nanomolar affinity for CCK(1) receptors, restricted dipeptoid derivative 15a, incorporating the type II' IBTM mimetic, shows approximately 6-fold higher CCK(1) selectivity than analogue 16a, with the type II mimetic. From these results, we propose that the presence of a beta-turn-like conformation within the peptide backbone of dipeptoids could contribute to their bioactive conformation at the CCK(1) receptor subtype. Concerning functional activity, compounds 15a and 16a behave as CCK(1) receptor antagonists.

5-(Tryptophyl)amino-1,3-dioxoperhydropyrido[1,2-c]pyrimidine-based potent and selective CCK(1) receptor antagonists: structural modifications at the tryptophan domain.

Analogues of the previously reported potent and highly selective CCK(1) receptor antagonist (4aS, 5R)-2-benzyl-5-(N-Boc-tryptophyl)amino-1,3-dioxoperhydropyrido-[1, 2-c]pyrimidine (2a) were prepared to explore the structural requirements at the Boc-tryptophan domain for CCK(1) receptor affinity. Structural modifications of 2a involved the Trp side chain, its conformational freedom, the Boc group, and the carboxamide bond. Results of the CCK binding and in vitro functional activity evaluation showed three highly strict structural requirements: the type and orientation of the Trp side chain, the H-bonding acceptor carbonyl group of the carboxamide bond, and the presence of the Trp amino protection Boc. Replacement of this acid-labile group with 3, 3-dimethylbutyryl or tert-butylaminocarbonyl conferred acid stability to analogues 14a and 15a, which retained a high potency and selectivity in binding to CCK(1) receptors, as well as an in vivo antagonist activity against the acute pancreatitis induced by caerulein in rats. Oral administration of compounds 14a and 15a also produced a lasting antagonism to the hypomotility induced by CCK-8 in mice, suggesting a good bioavailability and metabolic stability.

An iterative structure-assisted approach to sequence alignment and comparative modeling.

Correct alignment of the sequence of a target protein with those of homologues of known three-dimensional structure is a key step in comparative modeling. Usually an iterative approach that takes account of the local and overall structural features is required. We describe such an approach that exploits databases of structural alignments of homologous proteins (HOMSTRAD, http:/(/)www-cryst.bioc.cam.ac.uk/ approximately homstrad) and protein superfamilies (CAMPASS, http:/(/)www-cryst.bioc.cam.ac.uk/ approximately campass), in which structure-based alignments are analyzed and formatted with the program JOY (http:/(/)www-cryst.bioc.cam.ac.uk/ approximately joy) to reveal conserved local structural features. The databases facilitate the recognition of a family or superfamily, they assist in the selection of useful parent structures, they are helpful in alignment of the target sequences with the parent set, and are useful for deriving relationships that can be used in validating models. In the iterative approach, a model is constructed on the basis of the proposed sequence alignment and this is then reexpressed in the JOY format and realigned with the parent set. This is repeated until the model and sequence alignment is optimized. We examine the case for comparison and use of multiple structures of family members, rather than a single parent structure. We use the targets attempted by our group in CASP3 to assess the value of such procedures.

Characterization and modelling of VanT: a novel, membrane-bound, serine racemase from vancomycin-resistant Enterococcus gallinarum BM4174.

Sequence determination of a region downstream from the vanXYc gene in Enterococcus gallinarum BM4174 revealed an open reading frame, designated vanT, that encodes a 698-amino-acid polypeptide with an amino-terminal domain containing 10 predicted transmembrane segments. The protein contained a highly conserved pyridoxal phosphate attachment site in the C-terminal domain, typical of alanine racemases. The protein was overexpressed in Escherichia coli, and serine racemase activity was detected in the membrane but not in the cytoplasmic fraction after centrifugation of sonicated cells, whereas alanine racemase activity was located almost exclusively in the cytoplasm. When the protein was overexpressed as a polypeptide lacking the predicted transmembrane domain, serine racemase activity was detected in the cytoplasm. The serine racemase activity was partially (64%) inhibited by D-cycloserine, whereas host alanine racemase activity was almost totally inhibited (97%). Serine racemase activity was also detected in membrane preparations of constitutively vancomycin-resistant E. gallinarum BM4174 but not in BM4175, in which insertional inactivation of the vanC-1 D-Ala:D-Ser ligase gene probably had a polar effect on expression of the vanXYc and vanT genes. Comparative modelling of the deduced C-terminal domain was based on the alignment of VanT with the Air alanine racemase from Bacillus stearothermophilus. The model revealed that almost all critical amino acids in the active site of Air were conserved in VanT, indicating that the C-terminal domain of VanT is likely to adopt a three-dimensional structure similar to that of Air and that the protein could exist as a dimer. These results indicate that the source of D-serine for peptidoglycan synthesis in vancomycin-resistant enterococci expressing the VanC phenotype involves racemization of L- to D-serine by a membrane-bound serine racemase.

Highly constrained dipeptoid analogues containing a type II' beta-turn mimic as novel and selective CCK-A receptor ligands.

Conformationally constrained dipeptoid analogues containing the type II' beta-turn mimic (2S,5s,11bR)-2-amino-3-oxohexahydroindolizino[8,7-b]indole-5 -carboxylate framework in place of the alpha-MeTrp residue, show high binding affinity and selectivity for CCK-A receptors, suggesting that a turn-like conformation could contribute to the bioactive conformation at this CCK receptor subtype.

The insulin receptor: from protein sequence to structure.

Sequences of the insulin receptor (IR), the type-I insulin-like growth-factor receptor (IGFR) and the insulin-receptor-related receptor show that they belong to a homologous family but, until recently, have given few clues about their structures. Three repeats of fibronectin type III have been identified close to the membrane. Although the N-terminal L1, Cys-rich and L2 domains of the IGFR have been identified from their sequences and their structures determined by X-ray crystallography, little is known of their relative positions in the complete receptor in vivo. Here, we ask what can be learnt further from the analysis of sequences, about the structure, organization and function of the extracellular regions of the IR family.