Astrophysical and Theoretical Physics Implications from Multimessenger Neutron Star Observations.

The Neutron Star Interior Composition Explorer (NICER) recently measured the mass and equatorial radius of the isolated neutron star PSR J0030+0451. We use these measurements to infer the moment of inertia, the quadrupole moment, and the surface eccentricity of an isolated neutron star for the first time, using relations between these quantities that are insensitive to the unknown equation of state of supranuclear matter. We also use these results to forecast the moment of inertia of neutron star A in the double pulsar binary J0737-3039, a quantity anticipated to be directly measured in the coming decade with radio observations. Combining this information with the measurement of the tidal Love number with LIGO/Virgo observations, we propose and implement the first theory-agnostic and equation-of-state-insensitive test of general relativity. Specializing these constraints to a particular modified theory, we find that consistency with general relativity places the most stringent constraint on gravitational parity violation to date, surpassing all other previously reported bounds by 7 orders of magnitude and opens the path for a future test of general relativity with multimessenger neutron star observations.

Searching for Gravitational Waves from Cosmological Phase Transitions with the NANOGrav 12.5-Year Dataset.

We search for a first-order phase transition gravitational wave signal in 45 pulsars from the NANOGrav 12.5-year dataset. We find that the data can be modeled in terms of a strong first order phase transition taking place at temperatures below the electroweak scale. However, we do not observe any strong preference for a phase-transition interpretation of the signal over the standard astrophysical interpretation in terms of supermassive black hole mergers; but we expect to gain additional discriminating power with future datasets, improving the signal to noise ratio and extending the sensitivity window to lower frequencies. An interesting open question is how well gravitational wave observatories could separate such signals.

Maximizing the use of social and behavioural information from secondary care mental health electronic health records.

PURPOSE: The contribution of social and behavioural factors in the development of mental health conditions and treatment effectiveness is widely supported, yet there are weak population level data sources on social and behavioural determinants of mental health. Enriching these data gaps will be crucial to accelerating precision medicine. Some have suggested the broader use of electronic health records (EHR) as a source of non-clinical determinants, although social and behavioural information are not systematically collected metrics in EHRs, internationally. OBJECTIVE: In this commentary, we highlight the nature and quality of key available structured and unstructured social and behavioural data using a case example of value counts from secondary mental health data available in the UK from the UK Clinical Record Interactive Search (CRIS) database; highlight the methodological challenges in the use of such data; and possible solutions and opportunities involving the use of natural language processing (NLP) of unstructured EHR text. CONCLUSIONS: Most structured non-clinical data fields within secondary care mental health EHR data have too much missing data for adequate use. The utility of other non-clinical fields reported semi-consistently (e.g., ethnicity and marital status) is entirely dependent on treating them appropriately in analyses, quantifying the many reasons behind missingness in consideration of selection biases. Advancements in NLP offer new opportunities in the exploitation of unstructured text from secondary care EHR data particularly given that clinical notes and attachments are available in large volumes of patients and are more routinely completed by clinicians. Tackling ways to re-use, harmonize, and improve our existing and future secondary care mental health data, leveraging advanced analytics such as NLP is worth the effort in an attempt to fill the data gap on social and behavioural contributors to mental health conditions and will be necessary to fulfill all of the domains needed to inform personalized interventions.

Prevención de fractura osteoporótica en España: uso de fármacos antes y después de una fractura de cadera / Prevention of osteoporotic fracture in Spain: use of drugs before and after a hip fracture

Introducción: El tratamiento de la osteoporosis se orienta a prevenir la fractura por fragilidad, siendo la fractura de cadera la que más morbilidad y mortalidad produce. La existencia de una fractura previa es un importante predictor para una nueva fractura. Objetivo: Pretendemos analizar cómo varía el tratamiento de la osteoporosis antes y después de una fractura de cadera. Material y métodos: A partir de las 4.126.030 historias clínicas de la Base de Datos para la Investigación Farmacoepidemiológica en Atención Primaria (BIFAP) 2011 de toda España, se obtuvo información de pacientes con una primera fractura de cadera registrada entre 2005-2011, con seguimiento anterior y posterior de al menos un año. Analizamos el tratamiento previo y posterior para la osteoporosis (incluyendo suplementos de calcio y vitamina D). Resultados: Sufrieron una fractura de cadera 2.763 pacientes mayores de 60 años (media 81 años), de los que el 81,6% eran mujeres. Antes de la fractura, el 26,5% (intervalo de confianza [IC] 95%: 24,8-28,1%) habían recibido algún tratamiento antiosteoporótico, de los que el 12,2%, (IC 95%: 11,0-13,5%) era bisfosfonatos. Tras la fractura lo recibieron un 38,6% (IC 95%: 36,8-40,4%), fueron tratados con bisfosfonato 20,4% (IC 95%: 18,9-22%). Los factores asociados a iniciar un tratamiento tras la fractura fueron ser mujer, más joven y con diagnóstico previo de osteoporosis. Conclusiones: La mayoría de los pacientes estudiados no estaban recibiendo tratamiento preventivo antes de su fractura de cadera. Tras ella, aumentó modestamente la prescripción. Los fármacos más frecuentemente añadidos fueron calcio, vitamina D y bisfosfonatos (AU)

Introduction: Treatment of osteoporosis is focussed on the prevention fragility fractures, fractures of the hip being those which produce the highest rates of morbidity and mortality. The existence of a previous fracture is an important predictor of a new fracture. Objective: we intend to analyse how treatment for osteoporosis varies before and after a hip fracture. Material and methods: Using the 4,126,030 clinical records in the database for pharmaco-epidemiological research in primary care (Base de Datos para la Investigación Farmacoepidemiológica en Atención Primaria [BIFAP] ) 2011 for the whole of Spain, information was obtained regarding patients who had a first hip fracture recorded between 2005-2011, having been monitored for at least a year before and after. We analyse the previous and subsequent treatment for osteoporosis (including calcium and vitamin D supplements). Results: 2,763 patients over 60 years of age (average 81 years) had suffered a hip fracture, of whom 81.6% were women. Before the fracture 26.5% (95% confidence interval [CI]: 24.8-28.1%) had received some antiosteoporotic treatment, of which 12% (95% CI: 11.0-13.5%), were bisphosphonates. 38.6% (95%CI: 36.8-40.4%) received treatment after the fracture, 20.4% (95%: 18.9-22%) treated with bisphosphonates. The factors associated with the initiation of treatment after the fracture were being a woman, being younger and having a previous diagnosis of osteoporosis. Conclusions: Most of the patients studied were not receiving preventative treatment before their hip fracture. After the fracture the prescription of treatment increased a little. The drugs most commonly added were calcium, vitamin D and bisphosphonates (AU)

Valor pronóstico de la proteína fijadora de lipopolisácaridos y la procalcitonina en pacientes consepsis grave y shock séptico ingresados en una unidad de cuidados intensivos / Prognostic value of lipopolysaccharide binding protein and procalcitonin in patients with severe sepsis and septic shock admitted to intensive care

OBJETIVOS: 1) Valorar la utilidad pronóstica de la determinación inicial y seriada de la proteína fijadora de lipopolisacáridos (LBP) y de la procalcitonina (PCT) y 2) evaluar si su adicción a los scores de gravedad mejoraría su valor pronóstico. DISEÑO: Estudio prospectivo observacional. ÁMBITO: Unidad de Cuidados Intensivos de un hospital general universitario. PACIENTES: Se incluyó a 100 pacientes ingresados por sepsis grave/shock séptico. Variables de interés Datos demográficos, APACHE II y SOFA, concentración de PCT y LBP inicial y a las 48 h y mortalidad hospitalaria. RESULTADOS: Los scores APACHE II al ingreso y SOFA a las 48 h presentaron el mayor rendimiento como predictores de mortalidad hospitalaria (AUC ROC: 0,75 para ambos). La concentración inicial de PCT y LBP y el aclaramiento de LBP fueron similares en pacientes supervivientes y fallecidos. Solo el aclaramiento de PCT fue superior en supervivientes respecto a los fallecidos (AUC ROC: 0,66). La combinación de los scores de gravedad con el aclaramiento de PCT no mejoró su valor pronóstico. CONCLUSIONES: La concentración inicial de LBP y de PCT y el aclaramiento de LBP no presentaron valor pronóstico en pacientes con sepsis grave/shock séptico. Solo el aclaramiento de PCT se comportó como predictor de mortalidad hospitalaria. El rendimiento de los scores APACHE II al ingreso y SOFA a las 48 h fue superior al de los biomarcadores analizados y la adición del aclaramiento de PCT no aumentó su valor pronóstico

AIMS: 1) To assess the prognostic value of levels on admission and serial measurements of lipopolysaccharide binding protein (LBP) and procalcitonin (PCT) in relation to in-hospital mortality; and 2) to determine whether the addition of these parameters to severity scores (APACHE II and SOFA) is able to improve prognostic accuracy. DESIGN: A single-center, prospective observational study was carried out. Setting Intensive Care unit of a university hospital. PATIENTS: One hundred severe sepsis and septic shock patients were included. Data collected Demographic data, APACHE II and SOFA scores, PCT and LBP levels on admission and after 48hours, and in-hospital mortality. RESULTS: The best area under the curve for predicting in-hospital mortality corresponded to APACHE II on admission and SOFA after 48h (AUC ROC: 0.75 for both). PCT and LBP levels on admission and LBP clearance were not statistically different between in-hospital survivors and non-survivors. Only PCT clearance was higher among in-hospital survivors than in non-survivors (AUC ROC: 0.66). The combination of severity scores and PCT clearance did not result in superior areas under the curve. CONCLUSIONS: LBP and PCT levels on admission and LBP clearance showed no prognostic value in severe sepsis and septic shock patients. Only PCT clearance was predictive of in-hospital mortality. The prognostic accuracy was significantly better for APACHE on admission and SOFA after 48h than for any of the analyzed biomarkers, and the addition of PCT clearance did not improve their prognostic value

[Prognostic value of lipopolysaccharide binding protein and procalcitonin in patients with severe sepsis and septic shock admitted to intensive care]. / Valor pronóstico de la proteína fijadora de lipopolisácaridos y la procalcitonina en pacientes con sepsis grave y shock séptico ingresados en una unidad de cuidados intensivos.

AIMS: 1) To assess the prognostic value of levels on admission and serial measurements of lipopolysaccharide binding protein (LBP) and procalcitonin (PCT) in relation to in-hospital mortality; and 2) to determine whether the addition of these parameters to severity scores (APACHE II and SOFA) is able to improve prognostic accuracy. DESIGN: A single-center, prospective observational study was carried out. SETTING: Intensive Care unit of a university hospital. PATIENTS: One hundred severe sepsis and septic shock patients were included. DATA COLLECTED: Demographic data, APACHE II and SOFA scores, PCT and LBP levels on admission and after 48 hours, and in-hospital mortality. RESULTS: The best area under the curve for predicting in-hospital mortality corresponded to APACHE II on admission and SOFA after 48 h (AUC ROC: 0.75 for both). PCT and LBP levels on admission and LBP clearance were not statistically different between in-hospital survivors and non-survivors. Only PCT clearance was higher among in-hospital survivors than in non-survivors (AUC ROC: 0.66). The combination of severity scores and PCT clearance did not result in superior areas under the curve. CONCLUSIONS: LBP and PCT levels on admission and LBP clearance showed no prognostic value in severe sepsis and septic shock patients. Only PCT clearance was predictive of in-hospital mortality. The prognostic accuracy was significantly better for APACHE on admission and SOFA after 48 h than for any of the analyzed biomarkers, and the addition of PCT clearance did not improve their prognostic value.

Gestación en paciente con leucemia linfoide crónica B / No disponible

La coincidencia de embarazo junto con neoplasiamaligna de células linfoides es muy infrecuente, y todavía más encontrar una leucemia linfoide crónica Ben adulta joven embarazada. El control de estas pacientes debe ser muy cuidadoso por parte del obstetra y el hematólogo, informando con claridad y con un completo soporte bibliográfico basado en la evidencia científica acerca del conocimiento actual del tema, e intentando responder a todas las dudas que nos planteen. Se presenta el caso de una gestante de 31 años de edad que es diagnosticada de leucemia linfoide crónica B tras el primer control hematológico de rutina (AU)

The concurrence of pregnancy with malignant lymphoid neoplasia is highly infrequent, and a finding of B-cell chronic lymphoid leukemia in a young pregnant adult is exceptional. Careful management of these patients by the obstetrician and hematologist is required, with clear communication and complete literature support on the current knowledge of the topic, aiming to answer all the doubts posed. We present the case of a 31-year-old pregnant woman who was diagnosed with B-cell chronic lymphoid lymphoma in the first routine hematological visit (AU)

Characterisation of radioactive waste products associated with plant decommissioning.

The inventory of radioactivity that must be considered in the decommissioning of a typical 1000 MWe Spanish pressurised water reactor (PWR) was investigated as part of a generic plant decommissioning study. Analyses based on DORT models (in both R-Z and R-theta geometries) were used with representative plant operating history and core power distribution data in defining the expected neutron environment in regions near the reactor core. The activation analyses were performed by multiplying the DORT scalar fluxes by energy-dependent reaction cross sections (based on ENDF/B-VI data) to generate reaction rates on a per atom basis. The results from the ORIGEN2 computer code were also used for determining the activities associated with certain nuclides where multi-group cross section data were not available. In addition to the bulk material activation of equipment and structures near the reactor, the activated corrosion-product (or 'crud') deposits on system and equipment surfaces were considered. The projected activities associated with these sources were primarily based on plant data and experience from operating PWR plants.

Cáncer de cérvix. Análisis de 72 casos / Cancer of the cervix. Analysis of 72 cases

• Propósito: analizar la casuística y la evolución del cáncer de cérvix en nuestra Area Sanitaria desde laapertura del centro hasta nuestros días.• Material y métodos: es un trabajo retrospectivo. Se revisaron 72 casos de cáncer de cérvix diagnosticadosentre 1988 y 2003 en el Hospital Universitario Príncipe de Asturias de Alcalá de Henares. Se utilizó laclasificación anatomo-clínica FIGO.• Resultados: la edad media fue de 49,28 (16-80 años). El síntoma predominante lo constituyó la metrorragia(71,4%). El método diagnóstico de sospecha principal fue la citología (57,6%), y el de confirmación labiopsia exocervical (64,8%). Más de la mitad de los cánceres se diagnosticaron en estadio I (65,7%). El 77,5%correspondían a tumores epidermoides. El tratamiento primario principal lo constituyó la cirugía (56/72), seguidode la radioterapia (13/72) y de medidas paliativas (3/72). Tras 51,08 meses de seguimiento medio, se encuentranvivas el 68% de las pacientes.• Conclusiones: en el cáncer de cérvix, el screening se ha demostrado eficaz, hecho fundamental para eldiagnóstico precoz. La cirugía se mantiene como tratamiento primario principal y las tasas de supervivencia,en la actualidad, son elevadas

• Purpose: To analyze the casuistics and evolution of cervical cancer in our health center from its openingto nowadays.• Material and methods: A retrospective study of 72 cases of cervical cancer diagnosed between 1988and 2003 at the Príncipe de Asturias University Hospital of Alcalá de Henares is made. The FIGO stageclassification is used.• Results: The average age of the patients was 49.28 years (range 16-80 years). The predominant symptomwas metrorrhagia (71.4%). The main diagnostic method leading to suspect a cancer of the cervix was cervicalcytology (57.6%), using exocervical biopsy for diagnosis confirmation (64.8%). 65.7% of the cases werediagnosed in stage I, and 77.5% were squamous cell carcinomas. The principal primary treatment was surgery(56/72), followed by radiotherapy (13/72), and paliative care (3/72). After a follow-up of 51.08 months, 68%of the patients are alive.• Conclusions: Screening for cervical cancer is an effective prevention procedure of cancer of the cervixleading to an early diagnosis. Surgery is still considered the main primary treatment. Survival rates are high atpresent

Interaction of bifidobacteria with the gut and their influence in the immune function

Bifidobacteria are predominant in the lumen of the large intestine and confer various health benefits on the host. They are also used in the preparation of new fermented milks (bioyogurts) or added to conventional yogurt to generate probiotic effects. The colonization of the gut by bacteria tends to be host specific due partly to the way in which bacteria adhere to the intestinal wall. Using a homologous strain of Bifidobacterium animalis in an experimental mouse model, we analyzed by immunofluorescence labelled-bacteria and transmission electronic microscopy the importance of the bacterial interaction with epithelial an immune cells associated to the gut, and the effect of feeding of B. animalis in the immune response. It was able to adhere and interact with both small and large intestine. In spite of this interaction with the gut, no modifications in the immune state (secretory or systemic response) were observed. A heterologous strain of Bifidobacterium adolescentis from human faeces, was neither incapable of binding to the intestine, nor influence the immune system activation, when it was administered during 2, 5 or 7 consecutive days; we believe that using a homologous strain, oral tolerance is developed even when the microorganism interacts with the immune cells associated with the intestine. However, we cannot ignore the beneficial effect of these microorganisms, especially in the prevention of intestinal infections. We think that this property exerted by bifidobacteria is more related to other mechanisms such as competitive inhibition, acid production or others, than enhancement of the immune state.

Interaction of bifidobacteria with the gut and their influence in the immune function

Bifidobacteria are predominant in the lumen of the large intestine and confer various health benefits on the host. They are also used in the preparation of new fermented milks (bioyogurts) or added to conventional yogurt to generate probiotic effects. The colonization of the gut by bacteria tends to be host specific due partly to the way in which bacteria adhere to the intestinal wall. Using a homologous strain of Bifidobacterium animalis in an experimental mouse model, we analyzed by immunofluorescence labelled-bacteria and transmission electronic microscopy the importance of the bacterial interaction with epithelial an immune cells associated to the gut, and the effect of feeding of B. animalis in the immune response. It was able to adhere and interact with both small and large intestine. In spite of this interaction with the gut, no modifications in the immune state (secretory or systemic response) were observed. A heterologous strain of Bifidobacterium adolescentis from human faeces, was neither incapable of binding to the intestine, nor influence the immune system activation, when it was administered during 2, 5 or 7 consecutive days; we believe that using a homologous strain, oral tolerance is developed even when the microorganism interacts with the immune cells associated with the intestine. However, we cannot ignore the beneficial effect of these microorganisms, especially in the prevention of intestinal infections. We think that this property exerted by bifidobacteria is more related to other mechanisms such as competitive inhibition, acid production or others, than enhancement of the immune state. (AU)

Influence of pH, temperature and culture media on the growth and bacteriocin production by vaginal Lactobacillus salivarius CRL 1328.

AIMS: To study the influence of pH, temperature and culture medium on the growth and bacteriocin production by vaginal Lactobacillus salivarius subsp. salivarius CRL 1328. METHODS AND RESULTS: The study was performed using a complete factorial experimental design. Lactobacillus salivarius was cultivated in LAPTg and MRS broths, adjusted to specific initial pH, and at different temperatures of incubation. The growth, which was evaluated by the Gompertz model, was higher in MRS broth than in LAPTg broth. The initial pH of the culture medium and the temperature had a dramatic effect on the production of bacteriocin. The optimal conditions for bacteriocin production were different to those for optimal growth. The decrease in the pH of the culture medium was parallel to the growth; pH had similar final values in both the MRS and the LAPTg broths. CONCLUSIONS: The optimal growth conditions were recorded in MRS broth, with an initial pH of 6.5 and a temperature of 37 degrees C. The maximum bacteriocin activity was obtained in LAPTg after 6 h at 37 degrees C, and at an initial pH of 6.5 or 8.0. SIGNIFICANCE AND IMPACT OF THE STUDY: The application of a complete factorial design, and the evaluation of the growth parameters through the Gompertz model, enabled a rapid and simultaneous exploration of the influence of pH, temperature and growth medium on both growth and bacteriocin production by vaginal Lact. salivarius CRL 1328.

Utilidad del marcador cea en el seguimiento del cáncer de mama / The value of tumour marker cea in the follow up of breast cancer

El uso clínico de los marcadores tumorales en el seguimiento del cáncer de mama es controvertido. En 1.920 muestras de suero de 318 mujeres con historia de cáncer de mama, se analizó de forma retrospectiva la sensibilidad, la especificidad, el valor predictivo positivo y el valor predictivo negativo del marcador CEA. Un total de 59 pacientes recidivaron durante el estudio. La sensibilidad fue de 20,3 por ciento, la especificidad de 95,7 por ciento. El valor predictivo positivo de 52,1 por ciento y el valor predictivo negativo de 84,0 por ciento. La baja sensibilidad del marcador tumoral limita la utilidad clínica (AU)

A comparative study of preservation and storage of Haemophilus influenzae.

The aim of this study was to compare the efficacy of conservation by freezing the strains of Haemophilus influenzae at -20 degrees C and -70 degrees C. Skim milk supplemented with glucose, yeast extract and glycerol allowed highest viability of H. influenzae both at -20 degrees C and -70 degrees C from the media analyzed. Trypticase soy broth and brain heart infusion broth supplemented with glycerol, allowed excellent recovery. Use of cotton swaps as supporting material, with or without addition of cryoprotective agents, did not modify H. influenzae viability after six months of storage. Concentration of the initial inoculum positively affected viability when stored at -20 degrees C. Initial concentration did not influence survival after storage at -70 degrees C. Thawing at room temperature should not exceed 3 h as to get highest survival percentage.

Experimental administration of estradiol on the colonization of lactobacillus fermentum and escherichia coli in the urogenital tract of mice.

The effect of estrogen on the microbial colonization of the urogenital tract is widely discussed, mainly in regard to women with a high incidence of Urinary Tract Infections (UTI). The aim of this work was to study the effect of estradiol on the microbial colonization of lactobacilli and E. coli in mice. Female BALB/c mice were intramuscularly (i.m.) treated with beta-estradiol (one or three doses). The next day, L. fermentum was inoculated intraurethrally with three doses of 10(7) CFU (Colony Forming Units). Later, mice were challenged with uropathogenic E. coli (1 x 10(8) CFU). The hormone levels in sera increased to values 10 times higher than in control animals. Increased differentiation of desquamated vaginal cells and keratinization of the vaginal surface were also observed. The hormonal treatment produced an increased E. coli colonization in the whole tract and a higher level of L. fermentum in kidneys on the 6th day. In mice treated with hormones and lactobacilli, one dose of estradiol was enough to protect animals against the challenge with E. coli. Three doses of estradiol produced a more pronounced protection with a lower number of E. coli. No histological modifications were produced by L.fermentum, while lymphocytic proliferation at submucosal level was observed in E. coli-challenged animals.

Purification and characterization of beta-lactamase from Neisseria gonorrhoeae from clinical samples.

beta-Lactamase was isolated from Neisseria gonorrhoeae, obtained from male patients with gonococcic urethritis. Biochemical properties of the enzyme were studied. The enzyme was purified 38-fold by ammonium sulphate precipitation and using Sephadex G75 and DEAE-cellulose columns. The purified extract exhibited a single band by polyacrylamide gel electrophoresis. Maximum enzyme activity was obtained at 37 degrees C and pH 7.0-7.2 in 50 mM phosphate buffer. Addition of Ni2+, Fe2+, Fe3+, Mn2+ and p-chloromercurybenzoate to the reaction buffer partially inhibited beta-lactamase activity, whereas Hg2+ and EDTA produced complete inhibition. The molecular weight was estimated to be 35,000 Da and the pI of the enzyme was 5.4.

Enteric bifidobacteria: isolation from human infants and challenge studies in mice.

Bifidobacteria from breast-fed infants, formula-fed infants, or premature babies fed by parenteral methods were isolated and identified. The persistence of these microorganisms in the gastrointestinal tract of mice, after oral administration, was studied to determine the optimal dose and frequency of translocation to the liver and spleen. The rate of isolation among infants varied between 19 and 82% depending on the origin of the samples, with the highest values seen in breast-fed babies. The predominant species found in all cases was Bifidobacterium adolescentis. The optimal dose for oral administration of bifidobacteria to mice was 10(7) cells per day per animal for up to 2, 5, or 7 days. These bacteria remained up to 5 days postfeeding, even if feeding was interrupted. The results of bacterial translocation assays showed differences for the different strains and doses tested.

Bactericidal activity of lemon juice and lemon derivatives against Vibrio cholerae.

Food products can be possible vectors of the agent responsible for cholera epidemics, because some of these products allow Vibrio cholerae O1 to develop to concentrations above the dangerous level. This study deals with the behaviour of essential oils, natural and concentrated lemon juice and fresh and dehydrated lemon peel against V. cholerae O1 biotype Eltor serotype Inaba tox+. Our aim was to evaluate whether these products, used at different dilutions, exhibit bactericidal or bacteriostatic activity against the microorganism, when present at concentrations of 10(2), 10(4), 10(6) and 10(8) colony forming units (CFU) ml(-1), and after different exposure times. 10(8) CFU ml(-1) was considered an infectious dose. Concentrated lemon juice and essential oils inhibited V. cholerae completely at all studied dilutions and exposure times. Fresh lemon peel and dehydrated lemon peel partially inhibited growth of V. cholerae. Freshly squeezed lemon juice, diluted to 10(-2), showed complete inhibition of V. cholerae at a concentration of 10(8) CFU ml(-1) after 5 min of exposure time; a dilution of 2 x 10(-3) produced inhibition after 15 min and a dilution of 10(-3) after 30 min. It can be concluded that lemon, a natural product which is easily obtained, acts as a biocide against V. cholerae, and is, therefore, an efficient decontaminant, harmless to humans.