Pacientes con gripe por el virus influenza A (H1N1)pdm09 ingresados en la UCI. Impacto de las recomendaciones de la SEMICYUC / Patients with influenza A (H1N1)pdm09 admitted to the ICU. Impact of the recommendations of the SEMICYUC

OBJETIVOS: Evaluar el impacto de las recomendaciones SEMICYUC 2012 en la gripe A grave. DISEÑO: Prospectivo multicéntrico observacional. Ámbito: UCI. PACIENTES: Pacientes con virus influenza A (H1N1) grave (registro GETGAG/SEMICYUC). INTERVENCIONES: Análisis de 2 grupos según el periodo epidémico del diagnóstico (2009-2011; 2013-2015). VARIABLES: Demográficas, temporales, comorbilidades, gravedad, tratamientos, mortalidad, diagnóstico tardío y lugar de adquisición. RESULTADOS: Se incluyeron 2.205 pacientes, 1.337 (60,6%) en el primer periodo y 868 (39,4%) en el segundo. La edad, la gravedad al ingreso y la coinfección bacteriana fueron significativamente mayores en el segundo periodo. Respecto al impacto de las recomendaciones, en el segundo periodo el diagnóstico fue más precoz (70,8 vs. 61,1%, p < 0,001), sin cambios en el inicio del tratamiento. Se administraron menos corticoides (39,7 vs. 44,9%, p < 0,05), se utilizó más VMNI (47,4 vs. 33,2%, p < 0,001) y se objetivó una mayor tasa de vacunación (11,1 vs. 1,7%, p < 0,001), sin cambios en la mortalidad (24,2 vs. 20,7%). También se evidenció una disminución de la infección adquirida en el hospital (9,8 vs. 16%, p < 0,001). Asimismo, los pacientes requirieron menos VM con más días de ventilación, más vasopresores y más decúbito prono. CONCLUSIONES: El manejo de los pacientes con gripe A (H1N1) grave se ha modificado con los años, sin cambios en la mortalidad. Las recomendaciones de la SEMICYUC del año 2012 han mejorado el diagnóstico precoz y el uso de corticoides. Queda por mejorar el retraso en el tratamiento, la tasa de vacunación y la utilización de la VMNI

OBJECTIVES: To evaluate the impact of the recommendations of the SEMICYUC (2012) on severe influenza A. DESIGN: A prospective multicenter observational study was carried out. SETTING: ICU. PATIENTS: Patients infected with severe influenza A (H1N1) from the GETGAG/SEMICYUC registry. INTERVENTIONS: Analysis of 2 groups according to the epidemic period of the diagnosis (2009-2011; 2013-2015). VARIABLES: Demographic, temporal, comorbidities, severity, treatments, mortality, late diagnosis and place of acquisition. RESULTS: A total of 2,205 patients were included, 1,337 (60.6%) in the first period and 868 (39.4%) in the second one. Age and severity on admission were significantly greater in the second period, as well as co-infection. With regard to the impact of the recommendations, in the second period the diagnosis was established earlier (70.8 vs. 61.1%, P<.001), without changes in the start of treatment. Patients received less corticosteroid treatment (39.7 vs. 44.9%, P<.05), more NIMV was used (47.4 vs. 33.2%, P<.001) and more vaccination was made (11.1 vs. 1.7%, P<.001), without changes in mortality (24.2 vs. 20.7%). A decrease in nosocomial infection was also noted (9.8 vs. 16%, P<.001). Patients needed less MV with more days of ventilation, more vasopressor drug use and more ventral decubitus. CONCLUSIONS: The management of patients with severe influenza A (H1N1) has changed over the years, though without changes in mortality. The recommendations of the SEMICYUC (2012) have allowed earlier diagnosis and improved corticosteroid use. Pending challenges are the delay in treatment, the vaccination rate and the use of NIMV

La hipovitaminosis D grave al ingreso en el paciente crítico se asocia a fracaso renal agudo y mal pronóstico / Severe vitamin D deficiency upon admission in critically ill patients is related to acute kidney injury and a poor prognosis

OBJETIVOS: Determinar la prevalencia de hipovitaminosis D al ingreso en el Servicio de Medicina Intensiva (SMI), así como su asociación con el pronóstico del paciente crítico. DISEÑO: Análisis observacional prospectivo llevado a cabo desde enero a noviembre de 2015. Los pacientes incluidos fueron seguidos hasta su fallecimiento o alta hospitalaria. Ámbito: SMI polivalente de un hospital universitario. PACIENTES: Todos los individuos adultos que ingresaron en el SMI durante el periodo de estudio y que no presentaban factores conocidos que pudieran alterar los valores sanguíneos de 25(OH)D. INTERVENCIONES: Determinación de los niveles séricos de 25(OH)D en las primeras 24 h de ingreso en el SMI. Principales variables de interés: Prevalencia de hipovitaminosis D al ingreso en UCI y mortalidad a los 28 días. RESULTADOS: Se incluyeron 135 individuos. El 74% de los pacientes presentó niveles bajos de 25(OH)D en el momento de su ingreso en el SMI. El grupo de pacientes que fallecieron presentaba niveles significativamente inferiores al grupo de pacientes que sobrevivieron (8,14 ng/mL [6,17-11,53] vs. 12 ng/mL [7,1-20,30], p = 0,04) y el valor en sangre de 25(OH)D al ingreso se mostró como factor de riesgo independiente en el análisis multivariado (OR 2,86; IC 95% 1,05-7,86, p = 0,04). La curva ROC fue de 0,61 (IC 95% 0,51-0,75) y el mejor punto de corte para predecir mortalidad fue de 10,9 ng/mL. Los pacientes con valores de 25(OH)D < 10,9 ng/mL también presentaron mayores tasas de fracaso renal agudo (13 vs. 29%, p = 0,02). CONCLUSIÓN: Existe una elevada prevalencia de hipovitaminosis D en el momento de ingreso en el SMI. La hipovitaminosis D severa (25[OH]D < 10,9 ng/mL) al ingreso en el SMI se asocia a mayor incidencia de fracaso renal agudo y mayor mortalidad

OBJECTIVES: To evaluate the prevalence of vitamin D deficiency in critically ill patients upon admission to an Intensive Care Unit (ICU) and its prognostic implications. DESIGN: A single-center, prospective observational study was carried out from January to November 2015. Patients were followed-up on until death or hospital discharge. SETTING: The department of Critical Care Medicine of a university hospital. PATIENTS: All adults admitted to the ICU during the study period, without known factors capable of altering serum 25(OH)D concentration. INTERVENTIONS: Determination of serum 25(OH)D levels within the first 24 h following admission to the ICU. Main variables of interest: Prevalence and mortality at 28 days. RESULTS: The study included 135 patients, of which 74% presented deficient serum 25(OH)D levels upon admission to the ICU. Non-survivors showed significantly lower levels than survivors (8.14 ng/ml [6.17-11.53] vs. 12 ng/ml [7.1-20.30]; P = .04], and the serum 25(OH)D levels were independently associated to mortality (OR 2.86; 95% CI 1.05-7.86; P = .04]. The area under the ROC curve was 0.61 (95% CI 0.51-0.75), and the best cut-off point for predicting mortality was 10.9 ng/ml. Patients with serum 25(OH)D < 10.9 ng/ml also showed higher acute kidney injury rates (13 vs. 29%; P = .02). CONCLUSION: Vitamin D deficiency is highly prevalent upon admission to the ICU. Severe Vitamin D deficiency (25[OH]D < 10.9 ng/ml) upon admission to the ICU is associated to acute kidney injury and mortality

Patients with influenza A (H1N1)pdm09 admitted to the ICU. Impact of the recommendations of the SEMICYUC. / Pacientes con gripe por el virus influenza A (H1N1)pdm09 ingresados en la UCI. Impacto de las recomendaciones de la SEMICYUC.

OBJECTIVES: To evaluate the impact of the recommendations of the SEMICYUC (2012) on severe influenza A. DESIGN: A prospective multicenter observational study was carried out. SETTING: ICU. PATIENTS: Patients infected with severe influenza A (H1N1) from the GETGAG/SEMICYUC registry. INTERVENTIONS: Analysis of 2 groups according to the epidemic period of the diagnosis (2009-2011; 2013-2015). VARIABLES: Demographic, temporal, comorbidities, severity, treatments, mortality, late diagnosis and place of acquisition. RESULTS: A total of 2,205 patients were included, 1,337 (60.6%) in the first period and 868 (39.4%) in the second one. Age and severity on admission were significantly greater in the second period, as well as co-infection. With regard to the impact of the recommendations, in the second period the diagnosis was established earlier (70.8 vs. 61.1%, P<.001), without changes in the start of treatment. Patients received less corticosteroid treatment (39.7 vs. 44.9%, P<.05), more NIMV was used (47.4 vs. 33.2%, P<.001) and more vaccination was made (11.1 vs. 1.7%, P<.001), without changes in mortality (24.2 vs. 20.7%). A decrease in nosocomial infection was also noted (9.8 vs. 16%, P<.001). Patients needed less MV with more days of ventilation, more vasopressor drug use and more ventral decubitus. CONCLUSIONS: The management of patients with severe influenza A (H1N1) has changed over the years, though without changes in mortality. The recommendations of the SEMICYUC (2012) have allowed earlier diagnosis and improved corticosteroid use. Pending challenges are the delay in treatment, the vaccination rate and the use of NIMV.

Severe vitamin D deficiency upon admission in critically ill patients is related to acute kidney injury and a poor prognosis. / La hipovitaminosis D grave al ingreso en el paciente crítico se asocia a fracaso renal agudo y mal pronóstico.

OBJECTIVES: To evaluate the prevalence of vitamin D deficiency in critically ill patients upon admission to an Intensive Care Unit (ICU) and its prognostic implications. DESIGN: A single-center, prospective observational study was carried out from January to November 2015. Patients were followed-up on until death or hospital discharge. SETTING: The department of Critical Care Medicine of a university hospital. PATIENTS: All adults admitted to the ICU during the study period, without known factors capable of altering serum 25(OH)D concentration. INTERVENTIONS: Determination of serum 25(OH)D levels within the first 24h following admission to the ICU. MAIN VARIABLES OF INTEREST: Prevalence and mortality at 28 days. RESULTS: The study included 135 patients, of which 74% presented deficient serum 25(OH)D levels upon admission to the ICU. Non-survivors showed significantly lower levels than survivors (8.14ng/ml [6.17-11.53] vs. 12ng/ml [7.1-20.30]; P=.04], and the serum 25(OH)D levels were independently associated to mortality (OR 2.86; 95% CI 1.05-7.86; P=.04]. The area under the ROC curve was 0.61 (95% CI 0.51-0.75), and the best cut-off point for predicting mortality was 10.9ng/ml. Patients with serum 25(OH)D<10.9ng/ml also showed higher acute kidney injury rates (13 vs. 29%; P=.02). CONCLUSION: Vitamin D deficiency is highly prevalent upon admission to the ICU. Severe Vitamin D deficiency (25[OH]D<10.9ng/ml) upon admission to the ICU is associated to acute kidney injury and mortality.

KLIC-score for predicting early failure in prosthetic joint infections treated with debridement, implant retention and antibiotics.

Debridement, irrigation and antibiotic treatment form the current approach in early prosthetic joint infection (PJI). Our aim was to design a score to predict patients with a higher risk of failure. From 1999 to 2014 early PJIs were prospectively collected and retrospectively reviewed. The primary end-point was early failure defined as: 1) the need for unscheduled surgery, 2) death-related infection within the first 60 days after debridement or 3) the need for suppressive antibiotic treatment. A score was built-up according to the logistic regression coefficients of variables available before debridement. A total of 222 patients met the inclusion criteria. The most frequently isolated microorganisms were coagulase-negative staphylococci (95 cases, 42.8%) and Staphylococcus aureus (81 cases, 36.5%). Treatment of 52 (23.4%) cases failed. Independent predictors of failure were: chronic renal failure (OR 5.92, 95% CI 1.47-23.85), liver cirrhosis (OR 4.46, 95% CI 1.15-17.24), revision surgery (OR 4.34, 95% CI 1.34-14.04) or femoral neck fracture (OR 4.39, 95% CI1.16-16.62) compared with primary arthroplasty, C reactive protein >11.5 mg/dL (OR 12.308, 95% CI 4.56-33.19), cemented prosthesis (OR 8.71, 95% CI 1.95-38.97) and when all intraoperative cultures were positive (OR 6.30, 95% CI 1.84-21.53). A score for predicting the risk of failure was designed using preoperative factors (KLIC-score: Kidney, Liver, Index surgery, Cemented prosthesis and C-reactive protein value) and it ranged between 0 and 9.5 points. Patients with scores of ≤2, >2-3.5, 4-5, >5-6.5 and ≥7 had failure rates of 4.5%, 19.4%, 55%, 71.4% and 100%, respectively. The KLIC-score was highly predictive of early failure after debridement. In the future, it would be necessary to validate our score using cohorts from other institutions.

Calidad del proceso farmacoterapéutico a través de errores de medicación en un hospital terciario / Quality of drug treatment process through medication errors in a tertiary hospital

Objetivo: Evaluar la calidad del proceso farmacoterapéutico en un sistema de dosis unitaria y prescripción electrónica asistida en un hospital terciario, a través de errores de medicación. Métodos: Se realizó un estudio observacional prospectivo de errores de medicación en 308 pacientes hospitalizados, por revisión de la prescripción médica, la validación farmacéutica y la medicación preparada y dispensada, y por observación directa de la administración de medicamentos. La variable, el error de medicación, se analizó en la fase del proceso farmacoterapéutico, el tipo y la causa de error. Se definieron indicadores de calidad (relación porcentual de errores respecto a oportunidades de error) en cada fase. Resultados: De los 308 pacientes estudiados, en 107 se detectó al menos 1 error de medicación (34,7%); hubo un total de 137 errores distribuidos en: omisión de alergia y descripción de la prescripción (20,4%), prescripción/validación (28,5%), dispensación (23,4%) y administración de medicamentos (27,7%). El error más frecuente fue la omisión de dosis (19,7%) y la selección de especialidad farmacéutica (16,1%). La causa más común fue fallos de memoria y descuidos con el 53,3%. Los indicadores de calidad por fases fueron: 2,3% para la omisión de alergia del paciente; 0,9% para la prescripción; 1,6% para la prescripción/validación; 8,2% para la dispensación, y 2,1% para la administración de medicamentos. Conclusiones: Se estima que en 35 de 100 pacientes ocurre un error en su proceso farmacoterapéutico. Se identifican oportunidades de mejora basadas en la normalización y la formación de profesionales para realizar tareas técnicas y manejar la tecnología (AU)

Objective: To assess the quality of drug treatment process in a unit dose and assisted electronic prescription system in a tertiary hospital, by looking at medication errors. Methods: A prospective, observational study into medication errors was carried out on 308 hospitalised patients. This was done by assessing medical prescriptions, pharmaceutical validation, prepared and dispensed medication and by directly observing drug administration. The variable, i.e. the medication error, was analysed in the drug treatment process so as to decipher the type and cause of the error. Quality indicators were defined at each stage (percentage relationship between errors and opportunities for error).Results: Of the 308 patients studied, 107 had at least 1 medication error (34.7%). There were a total of 137 errors: omission of allergy and prescription description (20.4%), prescription/validation(28.5%), dispensing (23.4%) and drug administration (27.7%). The most frequent error was dose omission (19.7%) and choice of pharmaceutical product (16.1%). The most common cause of error was forgetfulness or a lack of attention to detail (53.3%). The quality indicators by stage were: 2.3% for omission of the patient’s allergies;0.9% for prescription; 1.6% for prescription/validation; 8.2% for dispensing, and 2.1% for drug administration. Conclusions: It is estimated that 35 patients in every 100 experience errors in their drug treatment process. Opportunities for improvement are identified based on standardisation and training for professionals in carrying out technical tasks and using technology (AU)

[Medication errors in a tertiary hospital with three different drug delivery systems]. / Errores de medicación en un hospital terciario con tres sistemas de distribución de medicamentos diferentes.

OBJECTIVE: To estimate the proportion of medication errors in a tertiary hospital, global and for each delivery medication system, to describe the error types and the implied medications, and to analyze the factors associated to the same ones. METHODS: Errors were identified from direct observation of 2,242 opportunities for error (administered doses or prescribed doses not given) by 6 couples of observers. Delivery medication systems were stock in ward, unit dose with electronic prescription and unit dose with computerized transcription. Logistic regression was used to evaluate the association between errors and certain factors. RESULTS: The medication error rate was of 7.2% (CI 95%: 6.1-8.3), and 4.4% (CI 95%: 3.6-5.3) of them reached the patient. For delivery systems, the error rate was of 9.5% (CI 95%: 7.4-11.9) for stock in ward, 7.8% (CI 95%: 5.9-10.0) for electronic prescription and 4.7% (CI 95%: 3.4-6.4) for computerized transcription. The highest error frequency was observed in the administration phase (58.4%) and the omitted dose was the most prevalent error (31.7%). The error rate was associated to the pharmacotherapeutic process, the schedule of administration and the unit of hospitalization. CONCLUSIONS: In one of each 14 opportunities for error a medication error takes place. The different delivery medication systems have different error rates.

Errores de medicación en un hospital terciario con tres sistemas de distribución de medicamentos diferentes / Medication errors in a tertiary hospital with three different drug delivery systems

Objetivo: Estimar la proporción de errores de medicación en un hospitalterciario, tanto de manera global como por sistemas de distribuciónde medicamentos, describir los tipos de error y los medicamentosimplicados y analizar los factores asociados a los mismos.Método: Los errores se identificaron mediante la observación directade 2.242 oportunidades de error (dosis administradas o lasprescritas y no administradas de medicamentos) por 6 pares deobservadores. Los sistemas de distribución fueron stock en planta,dosis unitarias con prescripción electrónica asistida y dosis unitariascon transcripción informatizada. Se utilizó la regresión logísticamúltiple para valorar la asociación entre errores y determinados factores.Resultados: El porcentaje global de error de medicación fue del7,2% (IC del 95%, 6,1-8,3), y un 4,4% (IC del 95%, 3,6-5,3) alcanzaronal paciente. Por sistemas de distribución, el porcentaje de error demedicación fue de 9,5% (IC del 95%, 7,4-11,9) para el stock en planta,7,8% (IC del 95%, 5,9-10,0) para la prescripción electrónica asistiday 4,7% (IC del 95%, 3,4-6,4) para la transcripción informatizada.La mayor frecuencia de errores se observó en la fase de administración(58,4%) y la dosis omitida fue el tipo de error más prevalente(31,7%). El riesgo de error se asoció al proceso farmacoterapéutico,al horario de administración y al tipo de unidad de hospitalización. Conclusiones: En una de cada 14 oportunidades de error se produceun error de medicación. Los distintos sistemas de administraciónde medicamentos tienen tasas de error diferentes

Objective: To estimate the proportion of medication errors in a tertiaryhospital, global and for each delivery medication system, to describethe error types and the implied medications, and to analyze thefactors associated to the same ones.Methods: Errors were identified from direct observation of 2,242 opportunitiesfor error (administered doses or prescribed doses not given)by 6 couples of observers. Delivery medication systems werestock in ward, unit dose with electronic prescription and unit dosewith computerized transcription. Logistic regression was used to evaluatethe association between errors and certain factors.Results: The medication error rate was of 7.2% (CI 95%: 6.1-8.3),and 4.4% (CI 95%: 3.6-5.3) of them reached the patient. For deliverysystems, the error rate was of 9.5% (CI 95%: 7.4-11.9) for stock inward, 7.8% (CI 95%: 5.9-10.0) for electronic prescription and 4.7%(CI 95%: 3.4-6.4) for computerized transcription. The highest errorfrequency was observed in the administration phase (58.4%) andthe omitted dose was the most prevalent error (31.7%). The errorrate was associated to the pharmacotherapeutic process, the scheduleof administration and the unit of hospitalization.Conclusions: In one of each 14 opportunities for error a medicationerror takes place. The different delivery medication systems have different error rates

[Quality of drug treatment process through medication errors in a tertiary hospital]. / Calidad del proceso farmacoterapéutico a través de errores de medicación en un hospital terciario.

OBJECTIVE: To assess the quality of drug treatment process in a unit-dose and assisted electronic prescription system in a tertiary hospital, by looking at medication errors. METHODS: A prospective, observational study into medication errors was carried out on 308 hospitalised patients. This was done by assessing medical prescriptions, pharmaceutical validation, prepared and dispensed medication and by directly observing drug administration. The variable, i.e. the medication error, was analysed in the drug treatment process so as to decipher the type and cause of the error. Quality indicators were defined at each stage (percentage relationship between errors and opportunities for error). RESULTS: Of the 308 patients studied, 107 had at least 1 medication error (34.7%). There were a total of 137 errors: omission of allergy and prescription description (20.4%), prescription/validation (28.5%), dispensing (23.4%) and drug administration (27.7%). The most frequent error was dose omission (19.7%) and choice of pharmaceutical product (16.1%). The most common cause of error was forgetfulness or a lack of attention to detail (53.3%). The quality indicators by stage were: 2.3% for omission of the patient's allergies; 0.9% for prescription; 1.6% for prescription/validation; 8.2% for dispensing, and 2.1% for drug administration. CONCLUSIONS: It is estimated that 35 patients in every 100 experience errors in their drug treatment process. Opportunities for improvement are identified based on standardisation and training for professionals in carrying out technical tasks and using technology.

Major histocompatibility complex class II polymorphisms and risk of cervical cancer in Puerto Rican women

Association between HLA antigens and cervical squamous cell carcinoma has been described in several populations. To verify whether HLA-DRB1 and DQB1 diversity is related to cervical cancer in Puerto Rican women, 40 cases and 50 controls were HLA typed. DRB1*16 (POR=2.89) and DRB1*11 (POR=1.74) were positively associated with cervical cancer. A negative association was found with DRB1*01 (POR=0.52), DRB1*04 (POR=0.60), DRB1*14 (POR=0.33), DRB1*15 (POR=0.65), DQB1*04 (POR=0.33), DQB1*05 (POR=0.64) and DQB1*06 (POR=0.65). We suggest that HLA Class H polymorphisms are involved in genetic susceptibility to cervical cancer in Puerto Rican women. These results should be confirmed in studies with larger sample size to preclude the possibility of false positive observations.

Comparison of outpatient point of care glucose testing vs venous glucose in the clinical laboratory

The purpose of this study was to evaluate the accuracy of glucometers in assessing glucose levels in outpatients. The investigation consisted in the analysis of retrospective validation data (obtained at the Clinical Laboratory of the Puerto Rico Medical Services Administration) and the analysis of data obtained from forty outpatients. Glucose concentration was obtained from these outpatient samples using the patients' glucometers and a clinical laboratory analyzer (hexokinase method). Statistical analysis included descriptive and correlation measures and t-test. Results revealed that accurate glucose values were obtained by the glucometers utilized in both the validation process and the outpatients (POCT) procedure. The investigation also demonstrated the need by outpatients to receive proper training in handling their glucometers.

Identification of a cytogenetic deletion and of four novel mutations (Q69X, I172F, G188V, G197R) affecting the gene for ornithine transcarbamylase (OTC) in Spanish patients with OTC deficiency.

A deletion of at least 11.5 cM in the paternal X chromosome mapping between microsatellites DXS989 and DXS1003 and encompassing the genes for ornithine transcarbamylase (OTC), retinitis pigmentosa GTPase regulator (RPGR) and dystrophin, was associated with the loss of band Xp21 in a female patient with OTC deficiency. Another four female patients were heterozygous for point mutations in the OTC gene: the nonsense mutation Q69X or the missense mutations I172F, G188V and G197R. In the OTC amino acid sequence, I172 and G197 are proximate to residues involved in catalysis, and G188 is within a loop joining helix 5 and strand 6 in the core of the ornithine-bindingdomain. Therefore, the mutations of these residues may cause structural changes affecting catalysis and/or the architecture of the ornithine domain. The mutation appeared "de novo" in the patients or, in one case, in the mother of the patient, in agreement with the predominance of "de novo" mutations in female patients of OTC deficiency. There was full agreement between the results of mutational analysis and of allopurinol testing in the patients and their female relatives, supporting the value of the allopurinol test in the detection of carriers of OTC deficiency. This deficiency is a genetically heterogeneous X-linked condition.

Optimization of allopurinol challenge: sample purification, protein intake control, and the use of orotidine response as a discriminative variable improve performance of the test for diagnosing ornithine carbamoyltransferase deficiency.

BACKGROUND: The diagnosis of heterozygosity for X-linked ornithine carbamoyltransferase (OCT) deficiency has usually been based on measurement of the increase of orotate and orotidine excretion after an allopurinol load. We examined the choices of analyte, cutoff, and test conditions to obtain maximal test accuracy. METHODS: Urine orotate/orotidine responses to allopurinol load in 37 children (13 OCT-deficient and 24 non-OCT-deficient) and 24 women (7 at risk for carrier status and 17 not related to OCT-deficient children) were analyzed by liquid chromatography after sample purification by anion-exchange chromatography. Diagnostic accuracy was evaluated by nonparametric ROC curves. RESULTS: Sample purification was necessary to prevent interferences. Orotate and orotidine excretion increased with increased protein intake during the test. At a cutoff of 8 mmol orotidine/mol creatinine, sensitivity was 1.0 and specificity was 0. 92 in mild forms of OCT deficiency. Results in monoplex carrier women may differ greatly from those expected because of the genetics of this deficiency. CONCLUSIONS: Standardization of protein intake is required in the allopurinol loading test. A negative response in the face of clinical suspicion should be followed with a repeat test during a protein intake not <2.5 g x kg-1 x day-1. Measurements of orotidine provide better clinical sensitivity than measurements of orotate.

[Achondroplasia: molecular study of 28 patients]. / Acondroplasia: estudio molecular de 28 pacientes.

BACKGROUND: The main goal of the study is to investigate in the Spanish population the value of searching for the Gly380Arg mutation in the transmembrane domain of fibroblast growth factor receptor-3 (FGFR3#) as the basis for the molecular diagnosis of achondroplasia. PATIENTS AND METHODS: Twenty eight achondroplastic patients were studied. Genomic DNA obtained from blood was used to amplify using PCR a 164 bp segment of FGFR3 encompassing the transmembrane domain. The occurrence of the G-->A transition and of the G-->C transversion at the first base of codon 380 were investigated by digestion with the restriction enzymes Sfcl and Mspl followed by electrophoretic analysis of the products. RESULTS: All achondroplastic patients were found to be heterozygous for the Gly380Arg mutation, as a consequence of the G-->A transition in 27 cases and of the G-->C transversion in the remaining patient. None of these changes were found in control subjects including a hypochondroplastic patient. CONCLUSIONS: The identification of the Gly380Arg mutation can be used in Spain for conclusive diagnosis of achondroplasia. The guanine at the first position of codon 380 of FGFR3 exhibits similarly increased frequency of mutation than in other populations, an thus it is unlikely that the genetic background of the population determines the mutation potential of this guanine.

Missense mutations in codon 225 of ornithine transcarbamylase (OTC) result in decreased amounts of OTC protein: a hypothesis on the molecular mechanism of the OTC deficiency.

Mutations P225L and P225R were identified in codon 225 of the gene for ornithine transcarbamylase (OTC) in two patients with the neonatal form of OTC deficiency. The mutations occur at a CpG dinucleotide and eliminate a unique MspI restriction site in exon 7 of the OTC gene. They do not alter existing splice sites or create new sites, as judged from the nucleotide sequence. Both mutations are associated with undetectable levels of OTC antigen in liver homogenates, and with either complete lack of OTC activity (P225R mutation) or very small residual activity (0.15% of normal in the P225L mutation). The residual activity observed with P225L exhibits normal pH dependence, little or no increases in the Km values for ornithine and carbamoyl phosphate and normal stability at either 37 degrees C or, in the presence of 0.66 mol/L urea, at 0 degree C. The latter conditions were used to examine whether the P225L mutation favours dissociation of the active OTC trimer. Given the normal stability and lack of tendency to dissociation of the mutant enzyme, it appears likely that the dramatic reduction in the level of OTC protein is due to inefficient conversion of the mutant OTC precursor polypeptide (pOTC) into the correctly localized, appropriately folded, mature enzyme trimer, suggesting degradation of pOTC in transit to the mitochondria.