Poor dental hygiene and periodontal health in nursing home residents with dementia: an observational study.

Poor oral health conditions are well documented in the institutionalized elderly, but the literature is lacking research on relationships between dementia and periodontal health in nursing home residents. The purpose of this cohort study, therefore, was to assess whether dementia is associated with poor oral health/denture hygiene and an increased risk of periodontal disease in the institutionalized elderly. A total of 219 participants were assessed using the Mini Mental State Examination (MMSE) to determine cognitive state. According to the MMSE outcome, participants scoring ≤20 were assigned to dementia group (D) and those scoring >20 to the non-dementia group (ND), respectively. For each of the groups D and ND, Gingival Bleeding Index (GBI) and Denture Hygiene Index (DHI) linear regression models were used with the confounders age, gender, dementia, number of comorbidities and number of permanent medications. To assess the risk factors for severe periodontitis as measured by the Community Index of Periodontal Treatment Needs, a logistic regression analysis was performed. Statistical analysis revealed no significant differences of GBI as well of DHI for demented and healthy subjects (p > 0.05). Severe periodontitis was detected in 66 % of participants with dementia. The logistic regression showed a 2.9 times increased risk among demented participants (p = 0.006). Oral hygiene, denture hygiene and periodontal health are poor in nursing home residents. The severity of oral problems, primarily periodontitis, seems to be enhanced in subjects suffering from dementia. Longitudinal observations are needed to clarify the cause-reaction relationship.

Carers' education improves oral health of older people suffering from dementia - results of an intervention study.

AIM: The aim of this study was to evaluate the effectiveness of carers' education on improvements in oral health and denture hygiene of care-dependent and cognitively impaired older people in nursing homes compared to those without intervention. METHODS: A total of 219 seniors living in 14 nursing homes in southwest Germany (intervention: n=144; control: n=75) were enrolled in this study. For each participant, Plaque Control Record (PCR), Gingival Bleeding Index (GBI), Denture Hygiene Index (DHI) and Community Periodontal Index of Treatment Needs (CPITN) were assessed at baseline and six months following the interventions. In addition, demographic parameters such as age, sex, chronic diseases, permanent medications, level of dependency and cognitive state were recorded. In the intervention homes, education for caregivers was provided and ultrasound baths for denture cleaning were implemented. Changes in the dental target variables PCR, GBI, CPITN and DHI during the six-month study period were compared between subjects in the intervention and the control groups as well as between subjects with and without dementia. Additionally, multivariate models were compiled for each dental index to evaluate possible confounders. RESULTS: In the intervention group, PCR and DHI significantly improved during the study period (P<0.001). Oral health and denture hygiene improved likewise in subjects with and without dementia. In the control group, no significant improvements were observed (P>0.05). CONCLUSION: Carers' education improves oral health of people in nursing homes over a clinically relevant period of time. Implementation of ultrasound baths is a simple and effective measure to improve denture hygiene of both institutionalized elderly people and seniors with dementia and in severe need of care. From a clinical standpoint, it is noteworthy that the respective interventions can be easily implemented in everyday care routine.

Improving oral health of institutionalized older people with diagnosed dementia.

OBJECTIVE: Previous research has revealed poor oral hygiene and health among older people suffering from dementia. To evaluate the oral health and denture hygiene of older people with and without dementia, six months after carer have followed a dental education programme. METHOD: Ninety-three older people living in four long-term care homes in south-western Germany were included in this longitudinal cohort study. All participants were allocated into two groups on basis of the medical dementia diagnosis extracted from the medical records in the care documentation: suffering from dementia (n = 33) or not (n = 60). For each participant plaque control record, gingival bleeding index (GBI), community periodontal index of treatment needs (CPITN), and denture hygiene index (DHI) were assessed at baseline and six months after carer have followed a dental education programme, and after use of ultrasonic devices for denture cleaning. Differences between all target variables from baseline to follow-up, and between participants with and without dementia, were evaluated by bivariate and multivariate testing. RESULTS: In bivariate testing, participants with dementia had a significantly lower DHI (p < 0.001), a lower GBI (p < 0.05), and a lower CPITN (p < 0.01) at follow-up. In participants without dementia, only for DHI (p < 0.001) a significant improvement was observed. In multivariate analyses, the significant association could not be reproduced (p > 0.05). CONCLUSIONS: Use of ultrasonic baths can be a successful means for improving denture hygiene among older people in long-term care with and without dementia. Education for carer in order to improve oral hygiene, however, seems to be of minor significance and to be more effective for people with dementia.

Prosthetic rehabilitation of edentulism prevents malnutrition in nursing home residents.

To investigate the association between prosthetic rehabilitation and malnutrition in institutionalized elders, 255 nursing home residents were recruited for this study and underwent a comprehensive dental examination. The body mass index (BMI) was administered to estimate the nutritional condition. Participants with BMI < 20 kg/mc were categorized as malnourished (n = 33), whereas all others were categorized as adequately nourished (n = 222). The number of teeth present and the prevalence of prosthetic rehabilitation were significantly lower in malnourished participants (P < .05). Malnutrition risk was 4.6 times higher for participants who were edentulous and did not wear dentures. Adequate replacement of teeth is important to prevent malnutrition in institutionalized older people.

Oral health and apraxia among institutionalized elderly people--a pilot study.

OBJECTIVE: Poor oral hygiene and dental health are very common among the institutionalized elderly. The purpose of this study was to evaluate the association of apraxia with oral hygiene and/or health. MATERIALS AND METHODS: Ninety-two residents of 13 long-term care homes in southwest Germany participated in the study. For each participant, ideomotor apraxia scoring (AS) was conducted and demographic variables were collected. Participants underwent a comprehensive dental examination to assess the oral health indices gingival bleeding index (GBI), community periodontal index of treatment needs (CPITN) and denture hygiene index (DHI). Statistical comparison of dental indices among apraxic and non-apraxic individuals (cut-off < 45) was performed by use of t-tests. In addition, linear regression models were constructed with the dental indices as dependent variables. Each model was fitted with the dichotomized variable AS (pathologic or healthy) and adjusted for age and sex. RESULTS: Mean (SD) GBI of 48.5 (25.9), CPITN of 2.9 (0.7) and DHI of 82.6 (14.6) were observed among the participants. Statistical analysis revealed AS was significantly associated with all oral health indicators (p < 0.05). Linear regression models showed apraxia is a predictor of GBI (p = 0.002) and CPITN (p = 0.027), but not of denture hygiene (p = 0.916). CONCLUSIONS: Although this pilot investigation has limitations, the results suggest the presence of apraxia should be considered when planning oral healthcare strategies. Further research with larger samples is encouraged to confirm these relationships.

Increasing dependency of older people in nursing homes is associated with need for dental treatments.

To determine relationships between the need for dental treatments of institutionalized elderly people and cognitive impairment and the general level of care needed. Two hundred and sixty-eight residents of long-term care facilities in Germany were included in this study. Age, sex, diseases, number of frequently taken drugs, and location of the long-term care facility of the participants were recorded. For each participant, the need for care was assessed by use of the Barthel index (BI). Cognitive impairment was evaluated by use of the mini-mental state examination (MMSE). To assess dental treatment needs, the revised oral assessment guide (ROAG) was applied for different oral health conditions, which were rated "healthy" or "treatment needed". Spearman correlations were performed to evaluate associations between BI and MMSE and dental treatment needs. Statistical analysis revealed significant associations of BI (P<0.001) and MMSE (P=0.015) with the ROAG score. Increasing dependency and decreasing cognitive ability worsen oral health and increase the need for dental treatment.

Determinants of oral health-related quality of life of the institutionalized elderly.

BACKGROUND: Diminished oral health of the institutionalized elderly has frequently been reported. This is not only of significance with regard to nutrition and general health, but it can also affect oral health-related quality of life. This paper evaluates the effects of oral and general conditions on oral health-related quality of life for the institutionalized elderly, as measured by the Geriatric Oral Health Assessment Index (GOHAI). MATERIALS AND METHODS: Ninety-four residents of four long-term care homes in southern Germany agreed to participate in this study, and interviews were conducted using the GOHAI questionnaire. The Revised Oral Health Assessment Guide was applied to allocate participants into two groups: satisfactory oral health and poor oral health. To evaluate the effects of age, gender, number of chronic diseases, frequently taken drugs, care level, Mini-Mental State Examination score, periodontitis (for participants with their own teeth), pressures caused by prostheses, and type of denture worn, a linear regression model with the total GOHAI score was calculated with these determinants. RESULTS: The mean ± SD GOHAI score was 53.3 ± 6.2 in the satisfactory oral health group and 48.7 ± 7.3 in the poor oral health group. Statistical analysis showed that the GOHAI scores were significantly different in satisfactory oral health and poor oral health groups (P = 0.030) and were affected by care level (P = 0.008) and type of dentures worn (P = 0.006). CONCLUSIONS: Within the limitations of this study, it can be concluded that oral health-related quality of life of the institutionalized elderly is low and is positively associated with better oral health.

Comparison of the Easyshade Compact and Advance in vitro and in vivo.

OBJECTIVE: The objective of this study was to evaluate the repeatability, inter-examiner and inter-device reliability, and accuracy of the new VITA Easyshade Advance (ES-A) spectrophotometer in comparison with the Easyshade Compact (ES-C). METHODS: For the in vitro study, six porcelain disks of random shade mixtures were fabricated from VITA ceramic powders. To analyze the repeatability of the ES-C and ES-A, readings were obtained by one examiner for one porcelain disk and one shade tab (VITA 3D-Master). Measurements were repeated by two examiners to evaluate inter-examiner reliability. To assess accuracy, porcelain disks and shade tabs were measured with the ES-C and ES-A and by means of a spectroradiometer (SR). ∆E values between the shade tabs and disks were calculated. Differences between devices were evaluated by use of univariate analysis. Reliability and accuracy of both devices were also tested in a clinical setting. The intra-class correlation coefficient (ICC) was calculated for all assessments of reliability. RESULTS: Good agreement was observed for replicate measurements (ICC > 0.9), for inter-examiner reliability of the ES-A and ES-C (ICC > 0.9), and for inter-device agreement (ICC > 0.9). Univariate analysis revealed that ∆E values for the spectrophotometers were consistent (p = 0.783); spectroradiometrically measured ∆E was comparable, but the mean value was smaller than that for the spectrophotometers (p = 0.004). Clinical inter-device agreement was acceptable to high (ICC > 0.777). The accuracy of the ES-A was higher than that of the ES-C (p = 0.001). CONCLUSION: Within the limitations of the experiment, the spectrophotometers tested enabled reliable and accurate measurement. In the clinical setting, however, the ES-A seems more accurate. CLINICAL RELEVANCE: ES-C and ES-A can be valuable tools for the determination of tooth colors. Because of their good reliability, they should especially be used for the assessment of tooth color changes over time.

Desarrollo embrionario-larval del pez tropical Hemirhamphus brasiliensis (Beloniformes: Hemirhamphidae) a partir de huevos recolectados del medio natural

Embrionary-larval development of the tropical fish Hemirhamphus brasiliensis (Beloniformes: Hemirhamphidae) from eggs collected in the wild. The embryo formation and larval development of Hemirhamphus brasiliensis Linnaeus, 1758 (Pisces: Hemirhamphidae) is described from morula stage eggs collected on Sargassum sp. Thalii in the field (10°50’55.2" N y 64°09’467" W). The eggs were spherical, 1 923.54 ±72.35 µm diameter with several corionic filaments, and are striated. During the first 48 h the embryo developed cephalic vesicle, miomers, and a heart located on the external body surface, beating strongly and circulating colorless blood which became pigmented red later. Before hatching, the larva developed kidney, gut tract, liver and biliar vesicle, pectoral fins, four pairs of gill arches and the mouth. The larva hatched at 114 h, the body was torpedo-shaped, yellow-green, with several dendriform melanophores; the pelvic fin was observed 72 h post hatching. At 240 hours the metamorphoses was completed. When the larvae hatched they could ingest Artemia metanauplii. Rev. Biol. Trop. 56 (3): 1449-1458. Epub 2008 September 30.

Se describe la formación del embrión y el desarrollo larval del pez Hemirhamphus brasiliensis Linnaeus, 1758, a partir de huevos en estado de mórula, recolectados en el alga parda Sargassum sp. Los huevos eran esféricos con un diámetro de 1923.54 ±72.35 µm, con numerosos filamentos coriónicos y estrías en su superficie. Durante las primeras 48 h, el embrión desarrolló la vesícula cefálica, los miomeros y el corazón, el cual se ubicó en el exterior de cuerpo impulsando sangre incolora, la cual se pigmentó de rojo posteriormente. Antes de la eclosión se desarrollaron el riñón, estómago, hígado y la vesícula biliar, las aletas pectorales, cuatro pares de arcos branquiales y la boca. Las larvas eclosionaron a la 114 h, presentando el cuerpo robusto en forma de torpedo, verde-amarillo con melanoforos dendriformes. Al nacer ingirieron metanauplios de Artemia. A las 72 h después de la eclosión se observó el esbozo de la aleta pélvica y a las 240 h se completó la metamorfosis.

[Embrionary-larval development of the tropical fish Hemirhamphus brasiliensis (Beloniformes: Hemirhamphidae) from eggs collected in the wild]. / Desarrollo embrionario-larval del pez tropical Hemirhamphus brasiliensis (Beloniformes: Hemirhamphidae) a partir de huevos recolectados del medio natural.

The embryo formation and larval development of Hemirhamphus brasiliensis Linnaeus, 1758 (Pisces: Hemirhamphidae) is described from morula stage eggs collected on Sargassum sp. Thalii in the field (10 degrees 50'55.2" N y 64 degrees 09'467" W). The eggs were spherical, 1 923.54 +/- 72.35 microm diameter with several corionic filaments, and are striated. During the first 48 h the embryo developed cephalic vesicle, miomers, and a heart located on the external body surface, beating strongly and circulating colorless blood which became pigmented red later. Before hatching, the larva developed kidney, gut tract, liver and biliar vesicle, pectoral fins, four pairs of gill arches and the mouth. The larva hatched at 114 h, the body was torpedo-shaped, yellow-green, with several dendriform melanophores; the pelvic fin was observed 72 h post hatching. At 240 hours the metamorphoses was completed. When the larvae hatched they could ingest Artemia metanauplii.

[Variation of the lipids and fatty acids in marine shrimps consumed in Venezuela]. / Variación de lípidos y ácidos grasos en camarones marinos consumidos en Venezuela.

There are three marine shrimp species in the Venezuelan internal market, two of them are native species, from fisheries, Farfantapenaeus brasiliensis and Litopenaeus schmitti, and one is an exotic species and farmed, L. vannamei. The objectives of this paper were to determine the possible variation of lipid content and fatty acid composition of these species, even under different culture conditions (e.g. feed used). The lipid content in all the species are higher (5 to 10 times) that the data from previous papers deal with marine shrimps, ranged from 4.8 to 10.9%, suggesting that its impact in the human health should be reviewed. At the same time, there were detected differences between the lipid content and fatty acids composition of the species. Wild L. schmitti had the highest lipid content (10.9%), following by wild F. brasiliensis (9.0%), cultured L. schmitti (4.8% to 7.1%) and cultured L. vannamei (5.1% to 6.2%). On the other hand, L. schmitti fed on commercial feed had the highest proportion of EPA and/or DHA, following by L. vannamei fed on the experimental feed, wild L. schmitti and fed with the experimental feed and wild F. brasiliensis.

Desarrollo embrionariolarval y tiempo de metamorfosis del pez tropical Xenomelaniris brasiliensis (Pisces: Atherinidae) / Development of the tropical fish Xenomelaniris brasiliensis (Pisces: Atherinidae) from embryo to larva and time to metamorphosis

Embryoniclarval development, and metamorphosis larval time, were studied in the tropical fish Xenomelaniris brasiliensis. Twenty nine sexually mature specimens were used, 16 females (10.86 ± 1.01 cm and 7.63 ± 2.62 g) and 13 males (10.43 ± 0.57 cm and 6.54 ± 1.44 g) which produced gametes through abdominal massage. Fertilized eggs were spherical (1.18 ± 0.44 mm diameter), greenish, transparent, benthonic and vitelusrich; rugose striated chorion with numerous external filaments randomly distributed and abundant oil globules (0.11 ± 0.07 mm diameter). The embryonic development was finished at 26.36 ± 2.03ºC, 39.67 ± 0.58 PSU and pH 8.30 ± 0.10. Larvae (4.56 ± 0.97 mm total length) hatched at 143 hours and 19 minutes, with vitteline sac vestiges and a single oil globule. The larvae were fed on Brachionus plicatilis and Isochrysis galbana. After the second week Artemia nauplii were added and I. galbana maintained. Flexion started 13 days after larvae hatched (6.10 ± 1.54 mm total length) and was completed 32 days later (11.25 ± 1.87 mm total length) with the hipural complex completely developed. In conclusion, X. brasiliensis showed direct larval development and started larval metamorphosis (13.08 ± 2.07 mm total length) to juvenile 40 days after hatching

Se describe el desarrollo embrionario y larval hasta la metamorfosis de Xenomelaniris brasiliensi. Un total de 29 ejemplares sexualmente maduros, 16 hembras (10.86 ± 1.01 cm y 7.63 ± 2.62 g) y 13 machos (10.43 ± 0.57 cm y 6.54 ± 1.44 g), liberaron sus productos sexuales mediante masaje abdominal. Los huevos fértiles fueron esféricos de 1.18 ± 0.44 mm de diámetro, verdosos, translúcidos, bentónicos, ricos en vitelo, corion rugoso y estriado, con numerosos filamentos coriónicos, distribuidos aleatoriamente por toda la superficie externa y numerosas gotas lipídicas con un diámetro de 0.11 ± 0.07 mm. El desarrollo embrionario se realizó a 26.36 ± 2.03 ºC, 39.67 ± 0.58 PSU y pH 8.30 ± 0.10 eclosionando larvas de 4.56 ± 0.97 mm a las 143 hrs: 19 min, con vestigios del saco vitelino y una gota lipídica interna. Las larvas fueron alimentadas diariamente con Brachionus plicatilis e Isochrysis galbana, a partir de la segunda semana se incorporó nauplios de Artemia, manteniendo la adición diaria de I. galbana. A los 13 días después de la eclosión de larvas (6.10 ± 1.54 mm) se inició la flexión, completándose a los 32 días (11.25 ± 1.87 mm) con un complejo hipural completamente desarrollado. Se concluye que X. brasiliensis presentó desarrollo larval directo, iniciándose la metamorfosis de larva (13.08 ± 2.07) a juvenil a los 40 días de edad

Variación de lípidos y ácidos grasos en camarones marinos consumidos en Venezuela / Variation of the lipids and fatty acids in marine shrimps consumed in Venezuela

En el mercado interno venezolano se consumen, fundamentalmente, tres especies de camarones marinos, dos autóctonas, encontradas en su ambiente natural, Farfantapenaeus brasiliensis y Litopenaeus schmitti, y una introducida y cultivada, L. vannamei. El objetivo del presente trabajo fue el de determinar, si existe variación en la proporción de lípidos y el perfíl de ácidos grasos de estas especies, incluso bajo diferentes condiciones de cultivo (balanceados utilizados). El total de lípidos detectado en todas las especies y condiciones de cultivo es mayor que el indicado en la bibliografía existente, superándolos en 5 a 10 veces, con valores que oscilan entre 4,8 y 10,9 por ciento, por lo que su incidencia en la salud debería ser revisada. Se evidenció una diferencia en el porcentaje de lípidos, así como en el perfíl de ácidos grasos de las especies. El mayor porcentaje de lípidos fue detectado en L. schmitti salvaje (10,9 por ciento) seguido de F. brasiliensis salvaje (9,0 por ciento),L. schmitti cultivado (4,8 por ciento a 7,1 por ciento) y L. vannamei cultivado (5,1 por ciento a 6,2 por ciento). De los camarones estudiados, L. schmitti cultivado con el balanceado comercial aparece con mayor proporción de EPA y/o DHA, seguido de L. vannamei alimentados con el balanceado experimental, L. schmitti salvaje y alimentado con el mismo balanceado y F. brasiliensis salvaje

[Development of the tropical fish Xenomelaniris brasiliensis (Pisces: Atherinidae) from embryo to larva and time to metamorphosis]. / Desarrollo embrionario-larval y tiempo de metamorfosis del pez tropical Xenomelaniris brasiliensis (Pisces: Atherinidae).

Embryonic-larval development, and metamorphosis larval time, were studied in the tropical fish Xenomelaniris brasiliensis. Twenty nine sexually mature specimens were used, 16 females (10.86+/-1.01 cm and 7.63+/-2.62 g) and 13 males (10.43+/-0.57 cm and 6.54+/-1.44 g) which produced gametes through abdominal massage. Fertilized eggs were spherical (1.18 +/-0.44 mm diameter), greenish, transparent, benthonic and vitelus-rich; rugose striated chorion with numerous external filaments randomly distributed and abundant oil globules (0.11 + 0.07 mm diameter). The embryonic development was finished at 26.36+/-2.03 degrees C, 39.67+/-0.58 PSU and pH 8.30+/-0.10. Larvae (4.56+/-0.97 mm total length) hatched at 143 hours and 19 minutes. with vitteline sac vestiges and a single oil globule. The larvae were fed on Brachionus plicatilis and Isochrysis galbana. After the second week .4rtemia nauplii were added and I. galbana maintained. Flexion started 13 days after larvae hatched (6.10+/-1.54 mm total length) and was completed 32 days later (11.25+/-1.87 mm total length) with the hipural complex completely developed. In conclusion, X brasiliensis showed direct larval development and started larval metamorphosis (13.08+/-2.07 mm total length) to juvenile 40 days after hatching.

[Larval survival and growth of Arbacia punctulata (Echinodermata: Echinoidea) fed with five micro-algae at two salinities]. / Supervivencia y crecimiento larval de Arbacia punctulata (Echinodermata: Echinoidea) alimentada con cinco microalgas a dos salinidades.

Fertilized eggs from an spontaneously spawn of thirty sexually mature sea urchins (Arbacia punctulata) were incubated to complete embryonic development. The echinopluteus larvae (3 ind/ml) were distributed into 50 plastic containers (25 containers at 30 psu and 25 containers at 40 psu) and fed on Tetraselmis chuii, Nannochloropsis oculata, Isochrysis galbana, Chaetoceros gracilis and C. calcitrans under a natural photoperiod. The water of the containers was partially renewed (75%) everyday. Larval anatomic development aspects, daily survival and growth were determined. The growth was determined through postoral arms and body length measurement, and body diameter of twelve larvae during metamorphosis. During the planktonic larval phase, only the I. galbana diet produced similar results for both salinities. The relative growth of larvae was isometric (I) for larvae fed on I. galbana at two salinities and positive allometric for those fed on C. gracilis and C. calcitrans at both salinities. In this study A. punctulata started metamorphosis at day 14 and was completed 30 days after fecundation. Significant differences were detected in post-settlement body growth between the two salinities (F = 23.58, p < 0.05): growth was better for larvae at 30 psu (final body diameter was 3.14 +/- 0.44 mm). The final rate of planktonic larvae was highest with I. galbana (58.33%). For juveniles the rate was 6.48% for those fed on C. gracilis (40 psu in both larvae and juveniles). We recommend the use of this diet and 40 psu for survival or 30 psu for growth.

[Larval growth and survival of Echinometra lucunter (Echinoidea: Echinometridae) fed with microalgae Chaetoceros gracilis and Isochrysis galbana]. / Crecimiento y supervivencia de larvas de Echinometra lucunter (Echinoidea: Echinometridae) alimentadas con las microalgas Chaetoceros gracilis e Isochrysis galbana.

Thirty sexually mature sea urchins (Echinometra lucunter; diameter 45.8 +/- 17.5 mm) were collected at Macanao, Margarita Island, Venezuela (11 degrees 48'29" N / 64 degrees 13'10" W). They were injected potassium chloride (50 M) directly into the celomic cavity. After two minutes 90% spawned (17 females and 10 males), the others never spawned. Fertilization was 87.0 +/- 12.6% (1:100 oocytes/sperm) at 29 +/- 2 degrees C. The fertile eggs were placed in three treatment gropsu with nine containers (18 liters; 2 eggs/ml) each, all with bottom aeration. Treatments were: Chaetoceros gracilis; Isochrysis galbana, and a mixture of both microalgae (respectively: 20 000 and 60,000 cell/ml for each microalgae, 1:1 for the mixture). Salinity, pH, temperature and larval survival were determinated daily. The study ended when the post-metamorphic phase was completed. The embryonic development time was 16.3 +/- 0.2 h until the prism stage at pH 8.4 +/- 0.1; 38 +/- 1 psu and 28 +/- 1.4 degrees C. The two-arms larval stage was reached at 24 h: 33 min, with a total length of 190 +/- 16.3 microm fed on C. gracilis, 152 +/- 19.0 microm with I. galbana and 182.4 +/- 14.1 microm with the mixture. The larvae next to metamorphosis reabsorbed the arms and had the characteristic shape of juvenile urchins at 12 days with 670.2 +/- 22.2 microm fed on C. gracilis, 665 +/- 12.1 microm fed on I. galbana and 670 +/- 14.1 microm fed on the mixture. The accumulated survival to the juvenile stage was 14.7 +/- 3.8% when fed on C. gracilis, higher than the other treatments (5.4 +/- 1.2; 14.0 +/- 2.6). E. lucunter is an excellent prospect to be commercially cultured because of its short embryonic (16 hours) and larval development time (12 days) and good survival rate when fed on monoculture (C. gracilis and I. galbana) or mixed diet (we recommend C. gracilis).

Estudio de brote de diarrea disentérica por Shigella sp. en una comunidad rural

el artículo contiene un estudio sobre el brote de diarrea disentérica causada por Shigella flexneri analizando los facxtores de riesgo, realizado a 13 flia(98 personas) de una comunidad rural el estudio fue realizado a travéz de una encuesta acerca de la condiciones ambientales y hábitos, así como el análisis microbiológico de las probables fuentes de infección ( agua de consumo, excretas)