Using in situ flow cytometry images of ciliates and dinoflagellates for aquatic system monitoring / Usando imagem de citometria de fluxo in situ de ciliados e dinoflagelados para o monitoramento de sistemas aquáticos

Abstract Short-period variability in plankton communities is poorly documented, especially for variations occurring in specific groups in the assemblage because traditional analysis is laborious and time-consuming. Moreover, it does not allow the high sampling frequency required for decision making. To overcome this limitation, we tested the submersible CytoSub flow cytometer. This device was anchored at a distance of approximately 10 metres from the low tide line at a depth of 1.5 metres for 12 hours to monitor the plankton at a site in the biological reserve of Barra da Tijuca beach, Rio de Janeiro. Data analysis was performed with two-dimensional scatter plots, individual pulse shapes and micro images acquisition. High-frequency monitoring results of two interesting groups are shown. The abundance and carbon biomass of ciliates were relatively stable, whereas those from dinoflagellates were highly variable along the day. The linear regression of biovolume measures between classical microscopy and in situ flow cytometry demonstrate high degree of adjustment. Despite the success of the trial and the promising results obtained, the large volume of images generated by the method also creates a need to develop pattern recognition models for automatic classification of in situ cytometric images.

Resumo A variabilidade de curto período em comunidades do plâncton é pouco documentada, especialmente as variações que ocorrem em grupos específicos das assembleias por causa das análises tradicionais serem muito trabalhosas e demoradas. Além disso, não permitem que a alta frequência amostral necessária para a tomada de decisão. Para superar esta limitação, nós testamos o CytoSub, um citômetro de fluxo submersível. Este aparelho foi ancorado a aproximadamente 10 metros de distância da linha de maré baixa a uma profundidade de 1,5 metros por 12 horas para monitorar o plâncton em um sítio da reserva biológica da praia da Barra da Tijuca, Rio de Janeiro. A análise dos dados foi realizada a partir de gráficos de dispersão bidimensionais, pelas assinaturas ópticas individuais escaneadas (pulse shape profile) e aquisição de micro imagens. Resultados do monitoramento de alta frequência de dois grupos interessantes são apresentados. A abundância e a biomassa de carbono de um grupo de ciliados foram relativamente estáveis, ao passo que o grupo de dinoflagelado, foi altamente variável ao longo do dia. O modelo de regressão linear das medidas de biovolume entre a clássica microscopia e a citometria de fluxo in situ apresentou alto grau de ajustamento. Apesar do sucesso deste ensaio e dos resultados promissores obtidos, o grande volume de imagens geradas por este método também gerou a necessidade de se desenvolver modelos de reconhecimento de padrões para a classificação automática de imagens de citometria in situ.

Using in situ flow cytometry images of ciliates and dinoflagellates for aquatic system monitoring.

Short-period variability in plankton communities is poorly documented, especially for variations occurring in specific groups in the assemblage because traditional analysis is laborious and time-consuming. Moreover, it does not allow the high sampling frequency required for decision making. To overcome this limitation, we tested the submersible CytoSub flow cytometer. This device was anchored at a distance of approximately 10 metres from the low tide line at a depth of 1.5 metres for 12 hours to monitor the plankton at a site in the biological reserve of Barra da Tijuca beach, Rio de Janeiro. Data analysis was performed with two-dimensional scatter plots, individual pulse shapes and micro images acquisition. High-frequency monitoring results of two interesting groups are shown. The abundance and carbon biomass of ciliates were relatively stable, whereas those from dinoflagellates were highly variable along the day. The linear regression of biovolume measures between classical microscopy and in situ flow cytometry demonstrate high degree of adjustment. Despite the success of the trial and the promising results obtained, the large volume of images generated by the method also creates a need to develop pattern recognition models for automatic classification of in situ cytometric images.

Temporary Medial Upper Eyelid Lagophthalmos after External Dacryocystorhinostomy.

Background. Report of three cases of medial upper eyelid lagophthalmos as complication of external dacryocystorhinostomy. History and Signs. Shortly after dacryocystorhinostomy (skin incision on the side of the nose), three of ten consecutive patients (28 ± 4 years; mean ± standard deviation), presented with an ipsilateral lagophthalmos of 4 ± 1 mm in voluntary eyelid closure and 6 ± 1 mm in spontaneous blink. The lagophthalmos was due to a selective paresis of the medial part of the orbicularis oculi muscle of the upper eyelid. Patient 1 complained bitterly of dry eye symptoms and of her lagophthalmos. Patient 2 had mild symptoms but became very concerned after peers made her aware of her asymmetric blink. Patient 3 was asymptomatic and did not notice anything particular. Therapy and Outcome. Lagophthalmos resolved spontaneously within three months after surgery, first by improvement of voluntary eyelid closure and then of spontaneous blinking. Conclusions. Temporary lagophthalmos can occur as a complication of external dacryocystorhinostomy, most likely due to damage of the (only recently described) superficial buccal and/or zygomatic branches of the facial nerve that run upward to cross over the medial ligament and innervate the medial part of the orbicularis oculi muscle.

Excision and Redraping Skin and Orbicularis Oculi Muscle Separately during Transcutaneous Lower Eyelid Blepharoplasty.

BACKGROUND: The purpose of this study was to report a transcutaneous lower eyelid blepharoplasty procedure where different amounts of skin and orbicularis oculi muscle are excised and where skin and muscle are redraped (tightened) separately. PATIENTS AND METHODS: A retrospective non-consecutive small case-series of patients undergoing lower eyelid blepharoplasty is described. In a nutshell, during this procedure a skin flap was fashioned (caudal to the sub-ciliary pre-tarsal excess of skin to be excised), some pre-septal orbicularis oculi muscle fibers were excised (in regard of the skin flap), muscle and then skin were redraped, separately. In addition to these surgical steps conducted on each patient, when required, orbital fat prolapse was reduced, orbital retaining ligament was detached, and/or a canthopexie/plasty was performed. Assessment of surgical outcome was made by providing, for comparison, pictures taken before and after the procedure. RESULTS: No major intra- or postoperative complications were recorded and overall postoperative outcome was judged satisfactory by both surgeons and patients. CONCLUSIONS: In contrast to a conventional skin-muscle lower blepharoplasty approach where, in a block, pre-tarsal skin and muscle are excised and then pre-septal skin and muscle are redraped, the technique described in the present paper allows us to excise different amounts of skin and orbicularis muscle and to redrape them separately. Among several potential advantages, this approach preserves pre-tarsal orbicularis muscle function, allows us to apply more tension on the redraped muscle and less on the redraped skin, and avoids redraping of a relatively thick per-septal orbicularis oculi muscle over the tarsus (like it is in the case of a conventional skin-muscle technique).

Treatment of epiphora in connection with endolacrimal surgery using trephines: new and overview data.

BACKGROUND: To provide new and to summarize published data on endolacrimal surgery with Piffaretti's trephines, in particular in patients having patent lacrimal drainage system (syringing) and epiphora resistant to medical treatments. PATIENTS AND METHODS: From two tertiary referral centers (Basel/Switzerland; Belo Horizonte/Brazil), 126 patients undergoing endolacrimal surgery with Piffaretti's trephines, combined, when clinically indicated, with other procedures known to improve epiphora (canthoplasty/pexie and/or conjunctivochalasisplasty). RESULTS: I) A study (Basel) in 17 patients showed one-year after surgery marked epiphora symptoms' improvement in 88% (15/17) of patients, 65% (11/17) being symptom-free. II) Unpublished data (Belo Horizonte) in 42 patients found 81% (34/42) symptom-free six-months after surgery. Dacryoscintigraphy illustrated postoperative tears' clearance improvement. III) Unpublished data (Belo Horizonte) in 45 patients solely undergoing endolacrimal surgery for complete ductal obstruction found symptom-free, six-months after surgery, 27% (8/30) of patients with preoperatively enlarged lacrimal sac and 80% (12/15) with none-enlarged sac (p < 0.01, Fisher's test). IV) A study (Basel) in 22 epiphora patients reported no correlation (p = 0.62, rho -0.11, Spearman) between preoperative basal Schirmer's test II (oxybuprocain-HCL 0.4%) values and one-year surgical outcome. Patients with preoperative Schirmer's test's values ≤ or > 6 mm had similar mean postoperative symptoms' improvement (82 ± 30%, n = 11 vs. 76 ± 34%, n = 11, p = 0.97, Mann-Whitney). CONCLUSIONS: Endolacrimal surgery with Piffaretti's trephines, sometimes combined, when clinically indicated, with other procedures also known to ameliorate epiphora, can in particular improve (different conditions, surgeons, centers) epiphora's symptoms resistant to medical treatments in patients with patent lacrimal drainage system, and this apparently, even when pre-operative basal Schirmer-test values are low. By enlarged lacrimal sac, outcome is poor.

Virioplankton abundance in trophic gradients of an upwelling field

This work correlates time series of biological and physical variables to the marine viruses across trophic gradients within Arraial do Cabo upwelling system, Southeast of Brazil. The objective is to investigate the major controlling factors of virioplankton dynamics among different water masses. It was used an in situ and ex situ flow cytometry for accessing the plankton community. Viruses were highly correlated to bacteria and phytoplankton, but although the lack of direct correlation with physicals, upwelling turned out to be the main contributing factor to the highest values of viral abundance and virus:bacterial ratio. Our data suggest that the lowest temperature of upwelled South Atlantic Central Waters would help to maintain a high viral abundance and higher temperatures of Coastal and Tropical Waters might be another ecological niche allowing the co-existence.

Cell membrane damage induced by phenolic acids on wine lactic acid bacteria.

The aim of this work was to investigate the effect of phenolic acids on cell membrane permeability of lactic acid bacteria from wine. Several phenolic acids were tested for their effects on the cell membrane of Oenococcus oeni and Lactobacillus hilgardii by measuring potassium and phosphate efflux, proton influx and by assessing culture viability employing a fluorescence technique based on membrane integrity. The experimental results indicate that hydroxycinnamic acids (p-coumaric, caffeic and ferulic acids) induce greater ion leakages and higher proton influx than hydroxybenzoic acids (p-hydroxibenzoic, protocatechuic, gallic, vanillic, and syringic acids). Among the hydroxycinnamic acids, p-coumaric acid showed the strongest effect. Moreover, the exposure of cells to phenolic acids caused a significant decrease in cell culture viability, as measured by the fluorescence assay, in both tested strains. The results agree with previous results obtained in growth experiments with the same strains. Generally, phenolic acids increased the cell membrane permeability in lactic acid bacteria from wine. The different effects of phenolic acids on membrane permeability could be related to differences in their structure and lipophilic character.

Virioplankton abundance in trophic gradients of an upwelling field.

This work correlates time series of biological and physical variables to the marine viruses across trophic gradients within Arraial do Cabo upwelling system, Southeast of Brazil. The objective is to investigate the major controlling factors of virioplankton dynamics among different water masses. It was used an in situ and ex situ flow cytometry for accessing the plankton community. Viruses were highly correlated to bacteria and phytoplankton, but although the lack of direct correlation with physicals, upwelling turned out to be the main contributing factor to the highest values of viral abundance and virus:bacterial ratio. Our data suggest that the lowest temperature of upwelled South Atlantic Central Waters would help to maintain a high viral abundance and higher temperatures of Coastal and Tropical Waters might be another ecological niche allowing the co-existence.

A surgical approach to treat chronic epiphora and/or muculopurulent discharge in patients with permeable lacrimal drainage system.

BACKGROUND: This study reports the one-year success rate of a new surgical approach to treat symptoms of chronic epiphora and/or mucopurulent discharge refractive to at least six months of medical treatment in patients with permeable lacrimal drainage system (irrigation test). DESIGN: retrospective chart review analysis. PARTICIPANTS: seventeen consecutive patients referred from a private praxis to an eye clinic to treat, by surgery, symptoms of either chronic epiphora (8/17), mucopurulent discharge (7/17), or both (2/17). INTERVENTION: Piffaretti's non-laser transpunctal endoscopic diagnostic/surgical lacrimal drainage procedure (17/17), lacrimal punctoplasty (16/17), conjunctivochalasisplasty (5/17), lateral canthoplasty (1/17), and/or both conjunctivochalasisplasty and lateral canthoplasty (3/17). In the majority of these patients (13/17) partial obstructions within the lacrimal canaliculus (3/17), the ductus nasolacrimalis (7/17), or both (3/17) were observed endoscopically and removed with Piffaretti's lacrimal trephines. MAIN OUTCOME MEASURES: patient's self-assessment of symptom improvement one year after surgery. RESULTS: One year after surgery, 88 % (15/18) of patients had a marked improvement of their symptoms, 64 % (11/17) of them even reporting as being symptom free. When conducted (14/17), irrigation always revealed a permeable lacrimal system (test not performed in a lost-to-follow-up and in two symptom-free patients). CONCLUSIONS: Surgery can be an alternative therapeutic option for patients who have a permeable lacrimal drainage system and suffer from chronic epiphora and/or mucopurulent discharge that do not respond to conventional conservative medical therapies.

Superficial conjunctiva cauterization to reduce moderate conjunctivochalasis.

AIM: We report here a simple surgical approach to reduce moderate conjunctivochalasis. PATIENTS AND METHODS: A non-comparative prospective interventional case series study of fifteen consecutive patients with moderate conjunctivochalasis was carried out. On the inferior bulbar conjunctiva 10 to 20 superficial burns were performed with an electrical bipolar cauter to reduce moderate conjunctivochalasis. Before and around a mean time of six months after surgery digital photographs of the conjunctivochalasis were taken at the slit lamp. The maximal height of the conjunctivochalasis above the lower eyelid margin measured before surgery was compared with the height of the conjunctivochalasis measured after surgery around the same location (one eye per patient). RESULTS: In each patient, gentle and superficial cauterization induced contraction of the bulbar conjunctiva and reduction of the conjunctivochalasis. No complications were noted during or after the procedure. Mean (+/- SD) maximal conjunctivochalasis height above the lower eyelid margin was higher before (2.3 +/- 0.9 mm) than after surgery (0.8 +/- 0.6 mm). Preoperative values of conjunctivochalasis height were significantly (p < 0.001) different from the postoperative ones (Wilcoxon rank signed test). CONCLUSIONS: Gentle superficial cauterization of the inferior bulbar conjunctiva can induced significant reduction of a moderate conjunctivochalasis.

Toxoplasmosis and mental retardation--report of a case-control study.

A case-control study evaluating the association between mental retardation and toxoplasmosis was conducted among 845 school children in Belo Horizonte, MG, Brazil. Cases (450) were mentally retarded children attending a public school for special education. Controls (395) were children from the regular public school system. Clinical and anthropometric examinations and interviews were carried out to determine risk factors for toxoplasmosis and mental retardation. Diagnosis of Toxoplasma gondii infection was based upon an indirect immunofluorescent test (IFA); 55% of cases and 29% of controls were positive. The Relative Odds of mental retardation in children with positive serology was 3.0 (95% CI 2.2-4.0). Maternal exposure to cats and contact with soil were associated with an increased risk of mental retardation. Retinochoroiditis was fourfold more prevalent among cases than controls and was only diagnosed in T. gondii IFA positive participants. Congenital toxoplasmosis, in its subclinical form, appears to be an important component in the etiology of mental retardation, especially in high risk (lower socio-economic) groups. The population attributable risk was estimated as 6.0-9.0%, suggesting the amount of mental retardation associated with this infection.

Aspectos oftalmológicos da associaçäo toxoplasmose congênita-deficiência mental: estudo epidemiológico / Ophthalmological findings of congenital toxoplasmosis-mental deficiency: epidemiological study

O autor realizou investigaçäo oftalmológica em 403 crianças, sendo 230 portadoras de deficiência mental em graus variados (Casos) e 173 com desenvolvimento intelectual considerado como normal (Controles), todas integrantes do Sistema Operacional de Ensino da Secretaria de Estado da Educaçäo de Minas Gerais, com o objetivo principal de detectar alteraçöes oftalmoscópicas e correlacioná-las com a presença de infecçäo por Toxoplasma gondii e com a condiçäo de deficiência mental, através de análises de associaçäo ("Odds Ratio"). O estudo teve caráter simples-cego; o autor näo conhecia os resultados da sorología (RIF) quando da realizaçäo do exame oftalmológico. Além da lesäo clássica da toxoplasmose ocular, foram consideradas como sugestivas de toxoplasmose as pequenas lesöes de retinocoroidite cicatrizada, detectadas pelo examinador, que se caracterizavam por centro pigmentado, halo hipocrômico, tamanho variando entre meio a um diâmetro papilar, localizadas a distância variáveis do pólo posterior, sem extrapolar os limites equatoriais. A associaçäo destas lesöes com a infecçäo toxoplásmica foi bastante alta ("Odds Ratio" = 34,4). Foi verificado que estas lesöes estavam associadas a condiçäo de deficiência mental, com "Odds Ratio" igual a 4,4, levando o autor a concluir que, as crianças que apresentavam esta lesäo têm uma chance quatro vezes maior de serem portadoras de deficiência mental por toxoplasmose do que as crianças sem a lesäo. As lesöes de degeneraçäo da periferia da retina e a palidez da cabeça do Nervo Optico também mostraram-se associadas a deficiência mental, mas associaçäo possivelmente foi determinada pela presença de outros fatores causais que näo a toxoplasmose