Adolescent experiences during perinatal care in the COVID-19 pandemic: synthesis of qualitative studies.

OBJECTIVES: To understand how the perinatal care experiences among adolescents were impacted during the early years of the COVID-19 pandemic. STUDY DESIGN: Integrative review. METHODS: We performed a search in the literature focusing on qualitative studies regarding the perceptions of pregnant adolescents during the pandemic (2020-2023). We described the most frequent thematic axes observed in the included studies, and we synthesized the results. RESULTS: The selection involved 69 articles, resulting in 9 studies from 7 countries (Indonesia, Kenya, the United Kingdom, South Africa, the United States, Malawi, and India). The studies highlight six main thematic axes: 1. Economic impact: the pandemic adversely influenced personal and family conditions, leading to early marriages and violence and exacerbating pre-existing economic inequalities. 2. Mental health: increased anxiety, depression, isolation, and fear among pregnant adolescents, with a focus on concerns related to contamination and perinatal uncertainties. 3. Compromised perinatal care: restrictions during prenatal and delivery care and lack of emotional and professional support lead to negative impacts on care for pregnant adolescents. 4. Breakdown of family Support network: school closures, family losses, and increased domestic violence affected family dynamics, influencing the occurrence of early pregnancies. 5. Impact on sexual education: school closures hindered access to contraceptives, contributing to unplanned pregnancies. 6. Vaccine hesitancy: misinformation led to hesitancy among pregnant women, highlighting the need for better communication to increase confidence in vaccination. CONCLUSIONS: The review emphasizes the wide geographic variety of the studies and highlights the interconnection between economic, social, and mental health factors. The pandemic intensified preexisting challenges, underscoring the importance of comprehensive support for pregnant adolescents, including emotional and psychological support. The COVID-19 pandemic exacerbated social and economic inequalities, negatively impacting the perinatal experiences of pregnant adolescents. The emphasis is on the need for comprehensive support, considering psychosocial factors, highlights the importance of more inclusive and sensitive health policies addressing the specific needs of this group during public health crises. The identified thematic axes, spanning economic, mental health, perinatal care, family support networks, sexual education, and vaccine hesitancy, illuminate the intricate challenges faced by adolescents during the pandemic. The identification of these axes provided a comprehensive analysis of the diverse consequences experienced by adolescents during the COVID-19 pandemic. It also allows the proposition of tailored interventions to mitigate the adverse effects on adolescent well-being and inform public health strategies for future pandemics or crises.

Effects of rumen-undegradable protein on intake, performance, and mammary gland development in prepubertal and pubertal dairy heifers.

The objective of this study was to evaluate the influence of different amounts of rumen-undegradable protein (RUP) on intake, N balance, performance, mammary gland development, carcass traits, and hormonal status of Holstein heifers at different physiological stages (PS). Sixteen prepubertal (PRE) heifers (initial BW = 106 ± 7.6 kg; age = 4.3 ± 0.46 mo) and 16 pubertal (PUB) heifers (initial BW = 224 ± 7.9 kg; age = 12.6 ± 0.45 mo) were used in an experiment over a period of 84 d. Four diets with increasing RUP contents (38, 44, 51, and 57% of dietary crude protein) and heifers at 2 PS (PRE or PUB) were used in a 4 × 2 factorial arrangement of treatments in a completely randomized design. Throughout the experiment, 2 digestibility trials were performed over 5 consecutive days (starting at d 36 and 78) involving feed and ort sampling and spot collections of feces and urine. At d 0 and 83, body ultrasound images were obtained for real-time carcass trait evaluation. The mammary gland was ultrasonically scanned at d 0 and every 3 wk during the experiment. Blood samples were taken at d 0 and 84 to determine serum concentrations of progesterone, estrogen, insulin-like growth factor I (IGF-I), and insulin. No interaction between PS and the level of RUP was found for any trait. Apparent digestibility of dry matter, organic matter, and neutral detergent fiber corrected for ash and protein was not affected by RUP level but was lower for PRE compared with PUB heifers. Sorting against neutral detergent fiber corrected for ash and protein (tendency only) and for crude protein was greater for PUB than PRE heifers. Pubertal heifers had greater average daily gain (905 vs. 505 g/d) and N retention (25.9 vs. 12.5 g/d) than PRE heifers. In addition, average daily gain and N retention were greatest at 51% RUP of dietary protein. Mammary ultrasonography indicated no effects of RUP amounts on mammary gland composition, whereas PRE heifers had greater pixel values than PUB, indicating higher contents of fat rather than protein in the mammary glands of PRE heifers. Serum progesterone and IGF-I concentration was affected only by PS, and PRE heifers had greater values of progesterone and IGF-I concentrations than PUB heifers. Serum insulin concentration was unaffected by PS but tended to be higher at 51% of RUP. In conclusion, an RUP level of 51% increases body weight, average daily gain, feed efficiency, and N retention in heifers regardless of the PS. In addition, PRE heifers have a lower sorting ability and reduced intake, total-tract digestibility, and N retention. They also have higher amounts of fat in their mammary glands, even at moderate growth rates.

The effects of increasing amounts of milk replacer powder added to whole milk on mammary gland measurements using ultrasound in dairy heifers.

The aim of this study was to determine the effect of increasing total solids (TS) in the liquid diet during the preweaning phase on mammary gland development in dairy heifers. The increase in TS was obtained with the addition of milk replacer powder to whole milk. Crossbreed Holstein-Gyr heifers (n = 60) were distributed in 4 treatments with different TS concentrations: 13.5% (n = 15), 16.1% (n = 15), 18.2% (n = 15), and 20.4% (n = 15). The liquid diets were provided from 5 to 55 d of age. From 56 to 59 d of age, the total amount of liquid feed was reduced by half. Heifers were weaned at 60 d and monitored until 90 d of age. Ultrasound mammary gland evaluations were performed weekly between 5 to 11 wk of age, using a B-mode ultrasound equipped with microconvex transducer at a frequency of 6 MHz. In those same weeks, the manual palpation of mammary parenchyma (PAR) was performed. Increased TS concentration of liquid diet during the preweaning period increased body weight of heifers, but did not alter PAR growth and the deposition of adipose tissue in the mammary gland evaluated by ultrasonography. The oval-shaped structure of PAR was altered after 2 mo of age. In the evaluated period, PAR growth was isometric with respect to the body growth rate. Palpation scoring of PAR had a strong correlation with the ultrasound evaluation of the PAR.

Colour-Doppler ultrasound imaging as a laparoscopy substitute to count corpora lutea in superovulated sheep.

This study evaluated colour-Doppler ultrasound imaging (UI) as a substitute for laparoscopy to count the corpora lutea (CL) in superovulated sheep. Twenty-five Santa Ines ewes were superovulated three times at 21-day intervals. Corpora lutea were counted by colour-Doppler UI (CLDOPPLER ) 6 days after each superovulation and confirmed by laparoscopy (CLLAP ) 12 hr later. The mean number of CL was similar for both techniques (2.1 ± 2.5 vs. 2.1 ± 2.7 for CLDOPPLER and CLLAP , respectively) with a significant positive correlation (r = .94; r2 =.89). Colour-Doppler UI effectively evaluated the ovarian response in superovulated ewes and efficiently identified animals that did not respond to superovulation.

Leptospirosis is strongly associated to estrus repetition on cattle.

Although prevalent, the exact impact of infectious diseases on reproductive failures remains to be determined. Among them, leptospirosis has commonly been reported as cause of abortions on outbreaks. Nevertheless, the majority of the animals present a chronic, silent form of the disease, which is characterized by low reproductive efficiency and is frequently neglected. In that context, we conducted a study that aims to estimate the impact of chronic leptospirosis on reproductive disorders on cattle. A total of 25 different dairy herds with history of reproductive losses from Rio de Janeiro, Brazil, were selected. From each herd, a questionnaire was applied and sera from 20 cows were randomly tested for leptospirosis (totaling 500 cows). Chi-square was performed to estimate the association of seroreactivity with reproductive disorders. A total of 32% of the herds were positive, all of them against serogroup Sejroe. Estrus repetition was the most important reported reproductive problem and it was strongly associated to seroreactivity against leptospirosis. Besides, specific vaccination against leptospirosis was an important protection factor against that disorder. In conclusion, control programs including, but not limited to, vaccines must be implemented on those herds in order to reduce reproductive losses, particularly estrus repetition.

Technical note: Mammary gland ultrasonography to evaluate mammary parenchymal composition in prepubertal heifers.

Bovine mammary gland development studies are often terminal or involve invasive biopsy procedures. Therefore, noninvasive means of assessing mammary development should be considered as alternative methods in live animals. The objective was to test if mammary ultrasonography can be used as a noninvasive way to estimate mammary parenchyma (PAR) composition in prepubertal dairy heifers with different average daily body weight gains. In the 84 d preceding, the ultrasound exam heifers were maintained in 1 of 3 treatment groups. Individual heifers were fed a high gain (1 kg/d; n = 6), low gain (0.5 kg/d, n = 6), or maintenance (n = 6) treatment diet. To achieve desired body weight gains, heifers were fed differing amounts of the same silage-based diet. Mammary glands of 18 crossbred heifers Holstein:Gyr underwent a single mammary ultrasound exam immediately before heifer slaughter, which took place when heifers weighed 142.0 ± 8.0 kg and were 200 d old. The 4 mammary glands of each heifer were evaluated using a real-time B-mode ultrasound machine equipped with a 6.5-MHz micro-convex transducer. Digital images (8-bit) of glands were obtained and PAR was identified within gland. Average pixel values per unit of PAR area were determined for each gland and analyzed at the level of heifer. Pixel results were interpreted on the basis that lower average pixel values reflect PAR with relatively high amounts of protein as opposed to fat. To help validate that the pixel value within PAR is associated with composition of PAR, pixel findings were compared with histological [number of adipocytes in PAR (Nad) and epithelial area in PAR (Ep)] and biochemical [percent crude protein in PAR (%CP), percent ether extract in PAR (%EE), PAR weight (WPAR), and mammary fat pad weight (WFAT)] composition of PAR in these same heifers. Within PAR, %EE and WFAT were positively correlated with pixel values, whereas %CP, Ep, and Nad were negatively correlated. Parenchyma weight did not correlate with pixel values. Regression analyses (fixed effect log-pixel value; random effect treatment) were used to estimate Nad, Ep, %CP, %EE, WPAR, and WFAT. Sensitivity analysis of regression equations revealed that accuracy of tested equations ranged from 0.77 to 0.93 and precision ranged from 0.56 to 0.82. Concordance correlation coefficients of the equations ranged from 0.41 to 0.76. In conclusion, ultrasonography of PAR can accurately measure and predict PAR composition in prepubertal dairy heifers growing at various rates of gain.

Effect of increasing amounts of milk replacer powder added to whole milk on postweaning performance, reproduction, glucose metabolism, and mammary fat pad in dairy heifers.

The aim of this study was to evaluate the effects of increasing the total solids (TS) content of liquid feed, by adding increasing amounts of milk replacer powder to whole milk, on age at puberty and postweaning performance, glucose metabolism, and mammary fat pad of dairy heifers. Crossbreed Holstein × Gyr heifers (n = 58) were distributed into 4 different treatments during the preweaning period. Treatments consisted of liquid feeds with TS content of 12.5 (actual TS = 13.5 ± 0.53%; n = 15), 15.0 (actual TS = 16.1 ± 0.03%; n = 15), 17.5 (actual TS = 18.2 ± 0.14%; n = 13), or 20.0% (actual TS = 20.4 ± 0.24%; n = 15), which were provided up to 59 d old. From 60 to 89 d old, the animals received the same starter offered during the preweaning period in addition to corn silage ad libitum starting at 70 d old. From 90 to 104 d old, the animals were adapted to a total mixed ration. At 105 d old, the animals were distributed in 4 paddocks equipped with electronic feed and water bins and were fed the same total mixed ration ad libitum. A period of adaptation to the electronic feed bins occurred from 105 to 119 d old. Feed and water intake and body weight and body frame development were assessed until puberty. Mammary gland evaluations were performed monthly by ultrasonography from 120 d of age until puberty onset. Puberty onset was determined as plasma progesterone concentration greater than 1 ng/mL in 2 consecutive samples collected 7 d apart. The date of puberty onset was recorded as the collection day of the first of these samples. A glucose tolerance test was performed at 280 d of age. The increased TS content of the liquid feed fed during the preweaning period did not affect dry matter intake, performance, age at puberty, glucose metabolism, or mammary gland fat pad at later stages of rearing process. Conversely, hip width and heart girth increased linearly up to 150 and 240 d of age, respectively, as a result of the increased TS concentration of the liquid feed during the preweaning period.

Effects of tacrolimus and erythropoietin in experimental spinal cord lesion in rats: functional and histological evaluation.

STUDY DESIGN: Experimental study with rats. OBJECTIVE: To evaluate functional and histological effects of tacrolimus (FK 506) and erythropoietin (EPO) after experimental spinal cord contusion injury (SCI). SETTING: Brazil. METHODS: Wistar rats (n=60) were submitted to SCI with the NYU Impactor system. The control group received saline; the EPO group received EPO; the group EPO+FK 506 received EPO associated with tacrolimus and the group FK 506 received tacrolimus only. The Sham group underwent SCI, but did not receive any drug. Locomotor function was evaluated after SCI by BBB (Basso, Beattie and Bresnahan) weekly and by the motor-evoked potential test in 42 days. The spinal cord was histologically evaluated. RESULTS: There was a significant difference between treated and the control groups from the seventh day on for BBB scores, with no difference between the groups EPO and EPO+FK 506 by the end of the study. There were significant differences between groups for necrosis and bleeding, but not for hiperemia, degeneration and cellular infiltrate. Axon neuron count was different between all groups (P=0.001), between EPO+FK 506 and FK 506 (P=0.011) and between EPO+FK 506 and Sham (P=0.002). Amplitude was significantly different between all groups except between control and sham. For latency, there was no difference. CONCLUSIONS: This study did not reveal significant differences in the recovery of locomotor function, or in the histological and electrophysiological analysis in animals treated with EPO and tacrolimus after thoracic SCI.

DNA barcoding and morphological identification of neotropical ichthyoplankton from the Upper Paraná and São Francisco.

The identification of fish larvae from two neotropical hydrographic basins using traditional morphological taxonomy and DNA barcoding revealed no conflicting results between the morphological and barcode identification of larvae. A lower rate (25%) of correct morphological identification of eggs as belonging to migratory or non-migratory species was achieved. Accurate identification of ichthyoplankton by DNA barcoding is an important tool for fish reproductive behaviour studies, correct estimation of biodiversity by detecting eggs from rare species, as well as defining environmental and management strategies for fish conservation in the neotropics.

Effects of antidepressant and treadmill gait training on recovery from spinal cord injury in rats.

STUDY DESIGN: Experimental, controlled, animal study. OBJECTIVES: To evaluate the influences of antidepressant treatment, treadmill gait training and a combination of these therapies in rats with experimental, acute spinal cord injury (SCI). SETTING: Brazil. METHODS: 48 Wistar rats were given standardized SCI; rats were then randomly assigned to four treatment groups: (1) motor rehabilitation therapy for 1 hour daily (gait training); (2) daily treatment with the antidepressant, fluoxetine (0.3 ml per 100 g intraperitoneally), beginning 24 h after the trauma; (3) combined fluoxetine treatment and gait training, or (4) untreated (controls). Neurological recovery was tested with the Basso, Beattie and Bresnahan (BBB) scale at 2, 7, 14, 21, 28 ,35 and 42 days after injury. Moreover, on day 42, all rats underwent a motor-evoked potential test (MEP); then, after euthanasia, histopathological evaluation was conducted in the area of SCI. RESULTS: Based on the BBB scale, the combined treatment group showed significantly greater improvement compared with the other three groups, from the 14th to the 42nd day of observation. The MEP revealed that all treated groups showed significant improvement compared with the control group (P<0.02 for latency and P<0.01 for amplitude). CONCLUSION: Our results indicated that a combination of antidepressant and treadmill gait training was superior to either treatment alone for improving functional deficits in rats with experimental, acute SCI.

Evaluation of genetic diversity and population structure in a commercially important freshwater fish Prochilodus costatus (Characiformes, Prochilodontidae) using complex hypervariable repeats.

We used complex hypervariable repeats to evaluate the genetic diversity and structure of Prochilodus costatus (Characiformes), an ecologically and economically important species endemic to the São Francisco River basin. Hydroelectric dams along the river have led to population fragmentation, which can limit gene flow. Restocking from hatcheries has been used to repopulate declining populations. To determine how fragmentation and hatchery supplementation affect P. costatus population structure, we studied populations from three sites up and downstream of the Gafanhoto Dam (Pará River, State of Minas Gerais). High levels of genetic diversity were found within populations (0.926 to 0.873); the three populations showed significant differentiation (F(ST) = 0.16), suggesting that populations from the three sites were affected by fragmentation of the river and by hatchery contributions. These results will be useful for developing a management and conservation plan for fish species in this area.

Chemical elements in sediments and in bivalve mollusks from estuarine regions in the south of Bahia State, northeast Brazil.

Estuaries receive daily inputs of chemical elements which can impact the quality of water and sediment, as well as the health of biota. In addition to the sediment, bivalve mollusks have been used in the chemical monitoring of these systems. This study investigated the presence and contents of As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in superficial sediment and in bivalves (Crassostrea gasar, C. rhizophorae and Mytella guyanensis) from estuaries in the south / extreme south of Bahia State, northeast Brazil. The samples were evaluated with inductively coupled plasma optical emission spectrometry (ICP-OES, Varian 710). Except for Cd, all other elements were found in the samples, being that Co was exclusive in the sediment. The estuaries equivalent to sampling stations #1 - Valença, #2 - Taperoá, #3 - Ilhéus and #4 - Belmonte showed levels of metals compatibles with those established by the Brazilian legislation, however, the #5 - Santa Cruz Cabrália, in addition to the presence of As, presented a high level of Pb and Cu in C. gasar, which was attributed to the impacts of nautical activities in that locality.

Potentializing the effects of GM1 by hyperbaric oxygen therapy in acute experimental spinal cord lesion in rats.

STUDY DESIGN: Experimental, controlled, animal study. OBJECTIVES: To evaluate the effect of GM1 ganglioside, hyperbaric oxygen and both in combination, in the treatment of experimental spinal cord lesions in rats. SETTING: Brazil. METHODS: Thirty-two Wistar rats with spinal cord lesions were divided into four groups: one group received GM1 ganglioside, one was submitted to hyperbaric oxygen therapy (HBOT), the third received both treatments and the fourth received no treatment (control). RESULTS: There were no significant differences between the groups in the histological analysis, for any of the variables (necrosis, hemorrhage, hyperemia, cystic degeneration, P>0.06). Neither were there any significant differences in the comparison of left and right sides in the functional tests (P>0.06 for all). No significant differences were found in the locomotor ratings, in the comparison of groups at 2, 7, 21 and 28 days after the surgical procedure. However, in the evaluation on day 14, group 3, which received the combined therapy, showed a significantly higher Basso Beattie and Bresnahan score than the other groups (P=0.015). CONCLUSION: The therapeutic effect of GM1 in locomotor evaluation of rats submitted to spinal cord lesion is anticipated by HBOT.

Morphometric analysis of Littoraria angulifera (Caenogastropoda) in estuarine regions of northeastern Brazil.

The gastropod Littoraria angulifera (Littorinidae) is an exclusively estuarine mollusk with Neotropical anfiatlantic distribution. Recent studies indicate a possible use of the species as bioindicator. The aim of this study was to analyze the shell height, as well as to perform a morphometric analysis of the reproductive apparatus of L. angulifera collected in 22 sampling points located between latitudes 13º54'S and 15º44'S in the South Atlantic, State of Bahia, Northeastern Brazil. The specimens were obtained in different estuarine environments including mangroves, as well as on rocks and concrete walls in places close to ports, shipyards and berths during January and February 2014. All specimens (n = 880) were analyzed regarding the sex and shell height/morphology, 440 were analyzed about the reproductive apparatus morphometry and 15 in histological description. The average shell height of animals from artificial substrates in nautical areas was lower (p<0.05) than the animals from mangroves, mainly in preserved areas, evidencing relation with human impacts and desiccation. The morphometric analysis of L. angulifera reproductive tract allowed us to conclude that the length of prostate in males and of palial oviduct in females may be useful in the reproductive evaluation of the species.

Observations on the seasonal breeding biology and fine structure of the egg surface in the white piranha Serrasalmus brandtii from the São Francisco River basin, Brazil.

In the Juramento Reservoir, south-eastern Brazil, the white piranha Serrasalmus brandtii showed a prolonged reproductive season, with evidence for multiple spawning and a reproductive peak associated with seasonal rains. The egg surface exhibited a honeycomb-like pore canal arrangement and an adhesive apparatus surrounding the micropyle. Electron microscopic analysis suggests a role for the micropylar cell and neighbouring follicular cells in secretion of substances for egg attachment.

Light transmission on dental resin composites.

OBJECTIVES: The purposes of this study was: (1) to examine the light transmittance characteristics of two light-cured resin composites, for different thickness, (2) to correlate the light transmittance through the resin composites and the filler contents, and (3) to determine the penetration depth of the light as a function of the wavelength. METHODS: Two resin composites (Filtek Z250, shade A2 and Filtek Supreme XT, shade A2E) were used. Specimens of six different thicknesses (0.15, 0.25, 0.30, 0.36, 0.47 and 0.75 mm) were prepared (n=3). The transmittance at wavelengths from 400 to 800 nm was measured using a UV-visible spectrophotometer, before and after light polymerization. RESULTS AND SIGNIFICANCE: Significant differences were found in the wavelength dependence of transmittance between the two materials, and between the unpolymerized and polymerized stages of each resin composite. At lower wavelengths, the light transmittance of the Filtek Supreme XT resin composite was lower than the Filtek Z250. At the higher wavelengths, however, Filtek Supreme XT presented higher light transmittance. For both resin composites, the penetration depth was higher after polymerization. However, Filtek Supreme XT showed a higher gain in transmittance at the 0.15 mm thickness. The difference in light transmittance characteristics of the resin composites may affect their depth of polymerization.

Chemical elements in sediments and in bivalve mollusks from estuarine regions in the south of Bahia State, northeast Brazil / Elementos químicos em sedimentos e em moluscos bivalves de regiões estuarinas do sul do Estado da Bahia, Nordeste do Brasil

Abstract Estuaries receive daily inputs of chemical elements which can impact the quality of water and sediment, as well as the health of biota. In addition to the sediment, bivalve mollusks have been used in the chemical monitoring of these systems. This study investigated the presence and contents of As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in superficial sediment and in bivalves (Crassostrea gasar, C. rhizophorae and Mytella guyanensis) from estuaries in the south / extreme south of Bahia State, northeast Brazil. The samples were evaluated with inductively coupled plasma optical emission spectrometry (ICP-OES, Varian 710). Except for Cd, all other elements were found in the samples, being that Co was exclusive in the sediment. The estuaries equivalent to sampling stations #1 - Valença, #2 - Taperoá, #3 - Ilhéus and #4 - Belmonte showed levels of metals compatibles with those established by the Brazilian legislation, however, the #5 - Santa Cruz Cabrália, in addition to the presence of As, presented a high level of Pb and Cu in C. gasar, which was attributed to the impacts of nautical activities in that locality.

Resumo Estuários recebem entradas diárias de elementos químicos, que podem impactar a qualidade de água e do sedimento, assim como a saúde da biota. Além do sedimento, moluscos bivalves têm sido utilizados no monitoramento químico desses sistemas. Neste estudo investigou-se a presença e os teores de As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb e Zn no sedimento superficial e em bivalves (Crassostrea gasar, C. rhizophorae e Mytella guyanensis) de estuários do sul / extremo sul do estado da Bahia, Nordeste do Brasil. As amostras foram avaliadas por espectrometria de emissão óptica de plasma indutivamente acoplado (ICP-OES, Varian 710). Exceto Cd, todos os demais elementos foram encontrados nas amostras, sendo que Co foi exclusivo no sedimento. Os estuários equivalentes às estações amostrais #1 - Valença, #2 - Taperoá, #3 - Ilhéus e #4 - Belmonte mostraram níveis de metais compatíveis com os estabelecidos pela legislação brasileira, porém, a #5 - Santa Cruz Cabrália, além da presença de As, apresentou alto nível de Pb e de Cu em C. gasar, o que foi atribuído aos impactos por atividades náuticas nesse local.

Chemical elements in sediments and in bivalve mollusks from estuarine regions in the south of Bahia State, northeast Brazil

Abstract Estuaries receive daily inputs of chemical elements which can impact the quality of water and sediment, as well as the health of biota. In addition to the sediment, bivalve mollusks have been used in the chemical monitoring of these systems. This study investigated the presence and contents of As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in superficial sediment and in bivalves (Crassostrea gasar, C. rhizophorae and Mytella guyanensis) from estuaries in the south / extreme south of Bahia State, northeast Brazil. The samples were evaluated with inductively coupled plasma optical emission spectrometry (ICP-OES, Varian 710). Except for Cd, all other elements were found in the samples, being that Co was exclusive in the sediment. The estuaries equivalent to sampling stations /1 - Valença, /2 - Taperoá, /3 - Ilhéus and /4 - Belmonte showed levels of metals compatibles with those established by the Brazilian legislation, however, the /5 - Santa Cruz Cabrália, in addition to the presence of As, presented a high level of Pb and Cu in C. gasar, which was attributed to the impacts of nautical activities in that locality.

Resumo Estuários recebem entradas diárias de elementos químicos, que podem impactar a qualidade de água e do sedimento, assim como a saúde da biota. Além do sedimento, moluscos bivalves têm sido utilizados no monitoramento químico desses sistemas. Neste estudo investigou-se a presença e os teores de As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb e Zn no sedimento superficial e em bivalves (Crassostrea gasar, C. rhizophorae e Mytella guyanensis) de estuários do sul / extremo sul do estado da Bahia, Nordeste do Brasil. As amostras foram avaliadas por espectrometria de emissão óptica de plasma indutivamente acoplado (ICP-OES, Varian 710). Exceto Cd, todos os demais elementos foram encontrados nas amostras, sendo que Co foi exclusivo no sedimento. Os estuários equivalentes às estações amostrais /1 - Valença, /2 - Taperoá, /3 - Ilhéus e /4 - Belmonte mostraram níveis de metais compatíveis com os estabelecidos pela legislação brasileira, porém, a /5 - Santa Cruz Cabrália, além da presença de As, apresentou alto nível de Pb e de Cu em C. gasar, o que foi atribuído aos impactos por atividades náuticas nesse local.

Chemical elements in sediments and in bivalve mollusks from estuarine regions in the south of Bahia State, northeast Brazil / Elementos químicos em sedimentos e em moluscos bivalves de regiões estuarinas do sul do Estado da Bahia, Nordeste do Brasil

Estuaries receive daily inputs of chemical elements which can impact the quality of water and sediment, as well as the health of biota. In addition to the sediment, bivalve mollusks have been used in the chemical monitoring of these systems. This study investigated the presence and contents of As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in superficial sediment and in bivalves (Crassostrea gasar, C. rhizophorae and Mytella guyanensis) from estuaries in the south / extreme south of Bahia State, northeast Brazil. The samples were evaluated with inductively coupled plasma optical emission spectrometry (ICP-OES, Varian 710). Except for Cd, all other elements were found in the samples, being that Co was exclusive in the sediment. The estuaries equivalent to sampling stations #1 - Valença, #2 - Taperoá, #3 - Ilhéus and #4 - Belmonte showed levels of metals compatibles with those established by the Brazilian legislation, however, the #5 - Santa Cruz Cabrália, in addition to the presence of As, presented a high level of Pb and Cu in C. gasar, which was attributed to the impacts of nautical activities in that locality.

Estuários recebem entradas diárias de elementos químicos, que podem impactar a qualidade de água e do sedimento, assim como a saúde da biota. Além do sedimento, moluscos bivalves têm sido utilizados no monitoramento químico desses sistemas. Neste estudo investigou-se a presença e os teores de As, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb e Zn no sedimento superficial e em bivalves (Crassostrea gasar, C. rhizophorae e Mytella guyanensis) de estuários do sul / extremo sul do estado da Bahia, Nordeste do Brasil. As amostras foram avaliadas por espectrometria de emissão óptica de plasma indutivamente acoplado (ICP-OES, Varian 710). Exceto Cd, todos os demais elementos foram encontrados nas amostras, sendo que Co foi exclusivo no sedimento. Os estuários equivalentes às estações amostrais #1 - Valença, #2 - Taperoá, #3 - Ilhéus e #4 - Belmonte mostraram níveis de metais compatíveis com os estabelecidos pela legislação brasileira, porém, a #5 - Santa Cruz Cabrália, além da presença de As, apresentou alto nível de Pb e de Cu em C. gasar, o que foi atribuído aos impactos por atividades náuticas nesse local.

Ovarian follicle growth in the catfish Iheringichthys labrosus (Siluriformes: Pimelodidae).

The morphofunctional organisation of the female reproductive system, the oocyte growth and the follicular envelope ultrastructure were studied by the first time in the catfish Iheringichthys labrosus from Upper Paraná River basin, Southeastern Brazil, in order to contribute to the knowledge of the reproductive behaviour strategies of this species. As in other Neotropical freshwater siluriforms, the ovaries are of the cystovarian type, the oocytes develop in an asynchronous pattern and mature oocytes are released in clusters in the ovarian lumen, being transported through the oviduct to the urogenital papilla. During the primary growth, nuclear material is transported to the ooplasm, forming the yolk nucleus, where proliferate membranous organelles. The onset of the zona radiata formation occurs during the late perionucleolar stage with the deposition of the outer layer. At the vitellogenic stage, this envelope reaches 6.35+/-0.84microm of thickness, being constituted by three distinct layers crossed by pore-canals containing oocyte and follicular cells processes. Cytochemical analyses evidence neutral glycoproteins in cortical alveoli, yolk globules and zona radiata. Follicular cells with squamous shape during the primary growth acquire synthetic activity at the secondary growth, reaching 37.82+/-4.72mum in height at the mature vitellogenic follicles. These cells accumulate sulphated polysaccharides in large electron-lucent vesicles during the vitellogenic stage which are possibly secreted to form a mucous coat at the egg surface. These evidences suggest that I. labrosus may have adhesive eggs as also detected in other Neotropical freshwater Siluriformes.