Eicosapentaenoic acid-rich oil supplementation activates PPAR-γ and delays skin wound healing in type 1 diabetic mice

Delayed wound healing is a devastating complication of diabetes and supplementation with fish oil, a source of anti-inflammatory omega-3 (ω-3) fatty acids including eicosapentaenoic acid (EPA), seems an appealing treatment strategy. However, some studies have shown that ω-3 fatty acids may have a deleterious effect on skin repair and the effects of oral administration of EPA on wound healing in diabetes are unclear. We used streptozotocin-induced diabetes as a mouse model to investigate the effects of oral administration of an EPA-rich oil on wound closure and quality of new tissue formed. Gas chromatography analysis of serum and skin showed that EPA-rich oil increased the incorporation of ω-3 and decreased ω-6 fatty acids, resulting in reduction of the ω-6/ω-3 ratio. On the tenth day after wounding, EPA increased production of IL-10 by neutrophils in the wound, reduced collagen deposition, and ultimately delayed wound closure and impaired quality of the healed tissue. This effect was PPAR-γ-dependent. EPA and IL-10 reduced collagen production by fibroblasts in vitro. In vivo, topical PPAR-γ-blockade reversed the deleterious effects of EPA on wound closure and on collagen organization in diabetic mice. We also observed a reduction in IL-10 production by neutrophils in diabetic mice treated topically with the PPAR-γ blocker. These results show that oral supplementation with EPA-rich oil impairs skin wound healing in diabetes, acting on inflammatory and non-inflammatory cells.

Photoacoustic for thermal diffusivity determination of fish scale: A methodology for environmental integrity monitoring

In this work the thermal diffusivity (D) of Astyanax lacustris fish scale is investigated aiming to use it for environmental integrity certification. The D values were obtained by a relatively simple procedure by a photoacoustic method. The chosen fish species is from wide occurrence in Brasil's basins. It has short migration, and it has also been used as environmental bioindicator. The results obtained in 195 scales sampled from three different streams in the Midwest region in Brazil gives an average value of D ~ 4 × 10^-3 cm²/s. ANCOVA analysis demonstrated that D values are able to differentiate among the three basins and indicates that it is dependent on the scales thickness and water conductivity. This last one is strongly affected by biotic and abiotic actions, so that D values measured by photoacoustic method can be used for interpreting the environmental integrity from where the fishes were sampled.

The implementation of a mobile application to support community-based health workers

Issue

Real-time access to up-to-date population information is essential to the strategic planning of primary health care (PHC). In the Brazilian public health system community-based health workers (CHWs), working as part of PHC teams, collect health, demographic and socio-economic data from individuals mainly through paper-based forms that are later entered manually into electronic information systems. Mobile applications could help to improve the quality and speed of this process facilitating the CHWs day-to-day work while improving the access to the collected information.

Description of the Problem

During September of 2019, a mobile application installed in tablets for the collection of health, demographic and socio-economic data was deployed for 432 CHWs of 87 PHC teams in the southern region of São Paulo, Brazil, serving a total population of 283,324 individuals. During implementation, the acceptability and challenges faced by CHWs were evaluated and the time taken to complete data entry.

Results

Seventy-two hours of training were offered to CHWs and other 139 professionals including managers, nurses and administrative staff (AS). Some CHWs reported concerns about the process change and fear of not being able to operate the application, especially those unfamiliar to the technology. With training and team support, fear was transformed into satisfaction with the realization of the benefits of the system. The main infrastructure challenge was the need for installation of Wi-Fi routers in some health care units, in addition to the replacement 4.4% of damaged tablets. In four months 97.6% of the total population was registered in the application.

Lessons

A WhatsApp group was created to clarify AS doubts, receive suggestions and disseminate guidelines. AS remained as the reference point at healthcare units and data completeness still needs to be reinforced.

Key messages

A mobile application was well-accepted by CHWs and could facilitate the collection of population data. A tablet app proved to be a useful tool to generate information for the PHC teams.

A soluble inorganic pyrophosphatase from the cattle tick Rhipicephalus microplus capable of hydrolysing polyphosphates

Polyphosphates have been found in all cell types examined to date and play diverse roles depending on the cell type. In eukaryotic organisms, polyphosphates have been investigated mainly in mammalian cells, and only a few studies have addressed arthropods. Pyrophosphatases have been shown to regulate polyphosphate metabolism. However, these studies were restricted to trypanosomatids. Here we focus on the tick Rhipicephalus microplus, a haematophagous ectoparasite that is highly harmful to cattle. We produced a recombinant R. microplus pyrophosphatase (rRmPPase) with the aim of investigating its kinetic parameters using polyphosphates as substrate. Molecular docking assays of RmPPase with polyphosphates were also carried out. The kinetic and Hill coefficient parameters indicated that rRmPPase has a greater affinity, higher catalytic efficiency and increased cooperativity for sodium phosphate glass type 15 (polyP₁₅ ) than for sodium tripolyphosphate (polyP₃ ). Through molecular docking, we found that polyP₃ binds close to the Mg²⁺ atoms in the catalytic region of the protein, participating in their coordination network, whereas polyP₁₅ interactions involve negatively charged phosphate groups and basic amino acid residues, such as Lys56, Arg58 and Lys193; polyP₁₅ has a more favourable theoretical binding affinity than polyP₃ , thus supporting the kinetic data. This study shows, for the first time in arthropods, a pyrophosphatase with polyphosphatase activity, suggesting its participation in polyphosphate metabolism.

Near-near-infrared thermal lens spectroscopy to assess overtones and combination bands of sulfentrazone pesticide

Thermal lens spectroscopy (TLS) in the near-near-infrared region was used to explore the absorptions of overtones and combination bands of sulfentrazone (SFZ) herbicide diluted in methanol. This spectroscopic region was chosen in order to guarantee that only thermal lens effect is noted during the experimental procedure. The results showed that it was possible to detect very low concentrations (~2ng/μL) of SFZ in methanol by determining its thermal diffusivity or the absorption coefficient due to the 3ν(NH)+1δ(CH) combination band. This minimum SFZ concentration is the limit observed by chromatography method. The findings demonstrated that the TLS can be used for precise and accurate assessment of pesticides in ecosystems. Besides, the 3ν(NH)+1δ(CH) combination band at 960nm can be used as a marker for SFZ in methanol.

Exposure assessment of a cyclist to particles and chemical elements

Cycle paths can be used as a route for active transportation or simply to cycle for physical activity and leisure. However, exposure to air pollutants can be boosted while cycling, in urban environments, due to the proximity to vehicular emissions and elevated breathing rates. The objective of this work was to assess the exposure of a cyclist to particles and to chemical elements by combining real-time aerosol mass concentration reading equipment and biomonitoring techniques. PM₁₀ and PM_2.5 were measured on three cycle paths located in Lisbon, during weekdays and weekends and during rush hours and off-peak hours resulting in a total of 60 campaigns. Lichens were exposed along cycle paths for 3 months, and their element contents were measured by instrumental neutron activation analysis using the k ₀ methodology (k ₀-INAA). Using a bicycle commute route of lower traffic intensity and avoiding rush hours or other times with elevated vehicular congestion facilitate a reduction in exposure to pollutants. The implementation of cycle paths in cities is important to stimulate physical activity and active transportation; however, it is essential to consider ambient air and pollutant sources to create safer infrastructures.

Measurements of refractive indices and thermo-optical coefficients using a white-light Michelson interferometer

A dispersive white-light Michelson interferometer was used to determine the wavelength dependence of the refractive index (n) in the visible range from 425 to 775 nm and the thermo-optical coefficient (dn/dT) of fused silica (FS) and borosilicate glass (BK7). For FS, the values obtained for n and dn/dT at 546 nm were 1.46079 and 11.3×10^-6  K^-1, respectively, while the values for BK7 glass were 1.51825 and 2.2×10^-6  K^-1, respectively, which is in good agreement with the literature. The accuracy of the methodology used for n was almost 10^-6, enabling precise spectroscopic characterization of materials across a wide spectral range.

Modeling the population lens effect in thermal lens spectrometry

We report a theoretical model and experimental results for laser-induced lensing in solids. The model distinguishes and quantifies the contributions from population and thermal effects. Laser-induced lensing in ytterbium-doped fluorozirconate glass ZBLAN:Yb(3+) is measured, and the thermal and optical properties obtained from analyzing the data with the proposed model agree well with published values. Photothermal techniques are used extensively for the investigation of laser and laser-cooling materials, and the model developed here enables the interpretation of convoluted laser-induced lensing signals that have contributions from different sources.

Comparison of stem cell properties of cells isolated from normal and inflamed dental pulps

AIM

To compare cells from normal and inflamed human dental pulps regarding the presence of stem cells, their proliferation and differentiation potential.

METHODOLOGY

Human dental pulp stem cells (hDPSCs) were isolated from normal (DPSC-N) and inflamed dental pulps (DPSC-I). They were compared in respect to proliferation (MTT assay), morphology and STRO-1 expression. STRO-1-positive cells were subject to proliferation (MTT and CFU counting) and morphological analyses and then submitted to odonto-osteogenic, adipogenic and condrogenic differentiation. Differentiated cells were evaluated concerning morphology and the expression, by qRT-PCR, of BSP, LPL and SOX-9 genes. The amount of mineralized matrix produced after odonto-osteogenic differentiation was compared with quantitative Alizarin Red staining.

RESULTS

No difference was observed in the morphology and in the proliferation rate of DPSC-N and DPSC-I either before or after separation of STRO-1-positive cells. These cells represented 0.46% (±0.14) and 0.43% (±0.19) of the cell population from normal and inflamed dental pulps, respectively. Both DPSC-N and DPSC-I were capable of differentiating under the three assayed conditions and presented similar patterns for BSP, LPL and SOX-9 expression. Mineralized matrix production was also compatible. In all the quantitative experiments, differences were found between cells from each patient, either from normal or from inflamed pulps. Nonetheless, there was no statistical difference between these two groups.

CONCLUSION

The morphology, proliferation rate and differentiation potential of DPSC-I were similar to the observed in DPSC-N, thus demonstrating that the inflammatory process did not affect the stem cell properties that were assessed.

Liposomal photosensitizers: potential platforms for anticancer photodynamic therapy

Photodynamic therapy is a well-established and clinically approved treatment for several types of cancer. Antineoplastic photodynamic therapy is based on photosensitizers, i.e., drugs that absorb photons translating light energy into a chemical potential that damages tumor tissues. Despite the encouraging clinical results with the approved photosensitizers available today, the prolonged skin phototoxicity, poor selectivity for diseased tissues, hydrophobic nature, and extended retention in the host organism shown by these drugs have stimulated researchers to develop new formulations for photodynamic therapy. In this context, due to their amphiphilic characteristic (compatibility with both hydrophobic and hydrophilic substances), liposomes have proven to be suitable carriers for photosensitizers, improving the photophysical properties of the photosensitizers. Moreover, as nanostructured drug delivery systems, liposomes improve the efficiency and safety of antineoplastic photodynamic therapy, mainly by the classical phenomenon of extended permeation and retention. Therefore, the association of photosensitizers with liposomes has been extensively studied. In this review, both current knowledge and future perspectives on liposomal carriers for antineoplastic photodynamic therapy are critically discussed.

Steady-state level of insulin-like growth factor-I (IGF-I) receptor mRNA and the effect of IGF-I on the in vitro culture of caprine preantral follicles

The objectives were to quantify insulin-like growth factor receptor-1 (IGFR-1) mRNA in preantral follicles on Days 0 and 18 of in vitro culture in the presence or absence of FSH, and to evaluate the effects of IGF-I on the rate of normal follicles, antral cavity formation, and in vitro growth and maturation of caprine oocytes on Days 0, 6, 12, and 18 of culture. The expression of IGFR-1 was analyzed using real-time RT-PCR before and after follicle culture. Preantral follicles were isolated from the cortex of caprine ovaries and individually cultured for 18 d in the presence or absence of bovine IGF-I (50 or 100 ng/mL). At the end of the culture period, the oocytes were submitted to IVM. The expression of IGFR-1 mRNA in preantral follicles cultured in vitro only approached being significantly higher in follicles supplemented with FSH when compared to follicles immediately after recovery (P<0.06) and cultured without FSH (P<0.1). There was a higher (P<0.05) percentage of normal follicles on Days 6, 12, and 18 of culture in IGF-I 50 (97, 92, 67%, respectively) and IGF-I 100 (100, 90, 80%) groups versus the control (90, 64, 36%). In addition, the rate of antrum formation at 6 and 12 d of culture was higher (P<0.05) in IGF-I groups (IGF-I 50: 72 and 90% and IGF-I 100: 69 and 85%) than the control group (41 and 59%). After 18 d of culture, the percentages of grown oocytes acceptable for IVM were higher (P<0.05) in follicles cultured in the presence of IGF-I (82 vs 49%). Furthermore, follicles cultured in the presence of IGF-I 50 and IGF-I 100 had higher (P<0.05) meiotic resumption rates (63 and 66%, respectively) than the control group (11%). In conclusion, treatment with FSH tended to increase IGFR-1 mRNA expression during the in vitro culture of preantral follicles and the addition of IGF-I to the culture medium clearly improved the in vitro development of caprine preantral follicles.

Affective style and eating disorders: a field study

Eating disorders (ED) are a heterogeneous group of problems related to restraint and/or overeating. It is proposed that individual differences in affective reactivity and moods (affective style) might be related to these behaviours. Variations in affective style are expressed by differing levels of sensitivity to the motivation systems of approach and avoidance. The present study tested whether a relation exists between ED and variations in the sensitivity of motivational systems as well as mood dispositions. A total of 2020 undergraduate students completed the Eating Disorder Diagnostic Scale (EDDS), the Behavioural Inhibition System and Behavioural Activation System Scales (BIS/BAS), and the Positive and Negative Affect Schedule (PANAS). The results showed a significant within- subject interaction of Alimentary group x Motivation (F=4.056; p<0.007). It was also observed that the Overeating group had lower levels of motivation asymmetry than the Normal (p<0.01) and Restrictive (p<0.005) groups and marginally lower levels than the Purgative group (p<0.07). The study results suggest mainly that the avoidance/inhibition motivational system is related to eating problems connected with overeating, including chronic alimentary restraint (chronic dieters). The theoretical and clinical implications of these findings are discussed.

High values of gain cross section and luminescence quantum efficiency in OH(-)-free Ti3+-doped low-silica calcium aluminosilicate glass

We recently reported that Ti(3+)-doped low-silica calcium aluminosilicate glass presents long luminescence lifetime (170 micros) and broad emission band (190 nm) shifted toward the visible region when compared with those from Ti(3+):sapphire single crystal and Ti(3+)-doped glasses [Phys. Rev. Lett.100, 027402 (2008)]. Here we demonstrate that this glass also shows high values of both gain cross section (approximately 4.7 x 10(-19) cm(2)) and luminescence quantum efficiency (approximately 70%). By comparing these values with those for Ti(3+):sapphire crystal, we can conclude that the studied Ti(3+)-doped glass is a promising system for tunable solid-state lasers.

Experimental study of induced inflammation in the Brazilian Boa (Boa constrictor constrictor)

The objective of this work was to identify the cellular types present in inflammatory processes in the Brazilian snake, Boa constrictor constrictor. Blood smears were first made from three normal snakes and stained by several methods to identify the cell types present, thus facilitating the identification of cells in inflammatory processes induced in 16 further snakes by the subcutaneous implantation of cotton suture threads and circular coverslips. Implanted threads induced migration of heterophils and monocytes after 4 h, more intense monocyte migration after 24 h, an intense granulocytic migration inside and around the thread after 48 h, heterophilic granulocytes, macrophages and giant cells after 7 days, and giant cells with a typical granuloma response and persistence of heterophilic cells after 15, 69 and 117 days. The cell population attached to the implanted coverslips after 4 h was composed of heterophils, thrombocytes, erythrocytes and macrophages; after 24 and 48 h heterophils predominated, and after 7 days heterophils, macrophages and giant cells predominated.

Effect of Braun-Collins and saline solutions at different temperatures and incubation times on the quality of goat preantral follicles preserved in situ

The present work has investigated the efficiency of Braun-Collins and saline (0.9%) solutions in the conservation of goat preantral follicles in situ, at different temperatures and incubation times. For each animal the ovarian pair was divided into 19 fragments. One ovarian fragment was taken randomly and immediately fixed (control). The other 18 ovarian fragments were randomly distributed in tubes containing Braun-Collins or saline (0.9%) solutions at 4, 20 or 39 degrees C for 4, 12 or 24h. A total of 3385, 372 and 191 primordial, primary and secondary follicles were examined, respectively. The quality of preantral follicles was evaluated by histology and transmission electron microscopy. The storage of ovarian fragments in saline (0.9%) or Braun-Collins solutions at 4 degrees C did not reduce significantly the percentage of morphologically normal follicles when compared with the control. The histological analysis revealed a morphological integrity of goat preantral follicles stored at 4 degrees C for up to 24h in both solutions, but these results were not confirmed by ultrastructural analysis. The transmission electron microscopy revealed that only preantral follicles stored at 4 degrees C for a maximum of 12h in both solutions were ultrastructurally normal. In conclusion, this study shows for the first time that goat preantral follicles can be stored in situ successfully at 4 degrees C in saline (0.9%) or Braun-Collins solution for up to 12h.

Ultrastructure of spermatogonia and primary spermatocytes of C57BL6J mice

The three types of spermatogonia were confirmed. Type A spermatogonia have a large nucleus and loose chromatin and are poor in endoplasmic reticulum. The second type, B spermatogonia, have rounded and smaller nuclei filled with more electron-dense nucleoplasmic material. The endoplasmic reticulum has the aspect of round or elongated cisterns that are free in the cytoplasm or close to the basement membrane. In contrast, intermediate spermatogonia present chromatin material with intermediate condensation compared with the two previous cell types. Primary spermatocytes are characterized by the presence of intercellular bridges and a synaptonemal complex. In the late pachytene stages, the synaptonemal complex was found to be enveloped by chromatin material.

Effects of storage time and temperature on atresia of goat ovarian preantral follicles held in M199 with or without indole-3-acetic acid supplementation

Maintenance of follicular quality after removal and during transport of ovaries is necessary for studies on development of preantral follicles in vitro. The present work investigated the effectiveness of M199 and M199IAA for preservation of goat preantral follicles in ovarian tissue. At the slaughterhouse, the ovarian pair of each animal was divided into 19 fragments. One ovarian fragment was immediately fixed (control--Time 0). The other 18 fragments were randomly distributed in M199 or M1991AA at 4, 20 or 39 degrees C and stored for 4, 12 or 24 h. Histological analysis showed that storage of ovarian fragments in either solution at 20 or 39 degrees C significantly reduced the percentage of normal preantral follicles when compared with the control, in all cases except after preservation in M199IAA at 20 degrees C for 4 h. In contrast, preservation at 4 degrees C, in either solution, kept the percentage of normal preantral follicles at control values. Reduced cellular metabolism may explain why the best preservation of preantral follicles was at 4 degrees C. The addition of IAA to the TCM 199 was effective for goat preantral follicle preservation at 20 degrees C for 4 h.

Morphological and ultrastructural changes occurring during degeneration of goat preantral follicles preserved in vitro

The present work has investigated the morphological and ultrastructural changes occurring during degeneration of goat preantral follicles preserved in vitro and showed quantitative data about the distribution of follicular degeneration types in the control and after preservation in coconut water solution or Braun-Collins solution at different temperatures (4, 20 or 39 degrees C) and incubation times (4, 12 or 24h). At the slaughterhouse, the pair of ovaries of each animal was divided into 19 fragments. One ovarian fragment was immediately fixed (control: Time 0). The other 18 fragments were randomly distributed in tubes containing 2ml of coconut water or Braun-Collins solution at 4, 20 or 39 degrees C and stored for 4, 12 or 24h. Normal preantral follicles exhibited a healthy oocyte surrounded by one or more well-organized layers of granulosa cells. The ooplasm contained numerous rounded or elongated mitochondria with continuous mitochondrial membranes. Golgi complexes were rare. Both smooth and rough endoplasmic reticulum were observed, either as isolated aggregations or complex associations with mitochondria and vesicles. Degenerated preantral follicles in the control tissue exhibited pycnotic nuclei of the oocyte, vacuolated ooplasm and normal granulosa cells. This kind of degeneration also predominated significantly (P<0.05) after preservation at 4 degrees C. In contrast, after preservation at 20 or 39 degrees C a significant predominance (P<0.05) of preantral follicles showing a retracted oocyte and swollen granulosa cells was observed. These follicles showed large irregularity of the oocyte and nuclear outlines. The ooplasm exhibited moderate proliferation of the endoplasmic reticulum and mitochondria showed disappearance of most of the cristae and damage to the mitochondrial membrane. Some follicles had numerous vacuoles in the ooplasm. Granulosa cells were spread and a low density of organelles was observed. The alterations in follicular structure progressed with an increase of temperature from 20 to 39 degrees C as well as with an increase of the incubation time from 4 to 12, or 24h. In conclusion, the present study shows for the first time that initial proliferation of the endoplasmic reticulum and damage to mitochondria are the first signs of degeneration in goat preantral follicles during storage in vitro.

Microvascular development and growth of uterine tissue during the estrous cycle in mares

OBJECTIVE

To document uterine growth and microvascular development in the endometrium of uteri with differing degrees of fibrosis as well as uterine growth throughout the estrous cycle of mares.

ANIMALS

30 mares.

PROCEDURE

Uterine tissue was obtained during the breeding season from a slaughter facility. Stage of estrous cycle of the mares was assessed on the basis of ovarian structures and plasma progesterone concentrations. Endometrium was characterized by use of light microscopy, and blood vessel walls were marked by histochemical techniques. Microvascular development was evaluated by a computerized image analysis system. Growth of uterine tissue was based on cellular content of DNA and RNA, RNA:DNA, and protein:DNA.

RESULTS

Significant differences in vascular density were not observed in the endometrium of uteri obtained from mares euthanatized during the follicular or luteal phase of the estrous cycle, regardless of whether endometrial classification of degree of fibrosis was considered. There was a 3-fold increase in amount of DNA and RNA of endometrial cells in the follicular phase when compared to myometrium. Hypertrophy of endometrial tissue during the luteal phase was reflected by a significant increase in cell protein content and protein:DNA.

CONCLUSIONS AND CLINICAL RELEVANCE

Endometrial growth of vascular tissues during the estrous cycle may be coordinated with development of nonvascular tissue. Estrogen and progesterone may play a role in regulation of uterine growth and angiogenesis.

Comparative Study of in Vivo and in Vitro Phagocytosis Including Germicidal Capacity in Odontaster validus (Koehler, 1906) at 0°C

The phagocytosis and germicidal capacity of Saccharomyces cerevisiae by phagocytic amoebocytes (PA) of the Antarctic starfish Odontaster validus were studied in vivo (after incubation periods of 1, 2, and 4 h) and in vitro (after incubation periods of 1, 2, 4, 8, and 12 h) at 0 degree C. The total number of PA and the phagocytic capacity (PC), phagocytic index (PI), and germicidal capacity (GC) of the PA were calculated. Results showed significant variability of the total PA number in different animals. There was a significant increase in PC and no significant differences in PI and GC for different in vitro incubation times. In vivo, experiments showed no significant difference of PC and PI, but there was a significant increase in GC as incubation periods increased. Comparison between in vitro and in vivo results revealed that PI and PC were significantly higher in vitro and that GC was significantly higher in vivo. The present study shows for the first time the phagocytosis and GC of an Antarctic invertebrate in vivo at low temperature (0 degree C), and the results are comparing with the available literature for echinoderms.

[Toxic effects and in vitro inefficacy of deltamethrin on larvae of Rhipicephalus sanguineus from Goiânia, Goiás, Brazil]

It has been observed that formulations of deltamethrin developed for disinsectization of infested places and control of parasitic arthropods of bovines and equines have frequently been used by breeders of dogs to control ticks in their animals and kennels, but without due consideration of the correct dosage or means of application. With the purpose of evaluating the efficacy of this product on Rhipicephalus sanguineus, bioassays were realized with larvae at 27+/-1 degrees C, UR>80% and light period of 12 hours. The mortality and toxicological effects were observed for 30 h, at 6 h intervals. Important toxicological effects were observed on the larvae, such as lack of co-ordination, knock-down and paralysis followed by death, although the lethal capacity of the product after 30 h was low, with mean mortality of only 34%, 40.2%, 46% and 57.6% respectively, for the 0.5 ml/l; 1 ml/l; 2 ml/l/; and 3 ml/l dosages. There was no mortality in the control group. The results obtained did not indicate the use of this formulation, in the tested dosages, as a method of choice for R. sanguineus control.

[An almost rhetorical appearance: photographs in medical journals of Sao Paulo, 1898-1920]

Neste artigo, procura-se refletir sobre a natureza e o significado das fotografias impressas nas páginas das primeiras revistas médicas paulistas. Sua história está intimamente ligada ao crescimento e à urbanização experimentados por São Paulo a partir das últimas décadas do século XIX, à imigração, às seguidas epidemias que assombraram a capital e o interior do Estado, e às instituições científicas de saúde montadas na cidade.

The onset of phagocytosis and identity in the embryo of Lytechinus variegatus

The stage at which phagocytosis can first be characterized in the embryos of the sea urchin Lytechinus variegatus was investigated by microinjecting the yeast Saccharomyces cerevisiae into its blastocoele. Secondary mesenchyme cells were first observed phagocytosing during the mid-gastrula stage. Subsequently, as the incubation time increased, the number of yeast per phagocyte rose. Using vital fluorescence dyes, stained free yeast were seen in the blastocoele during late-gastrula stage, indicating cell death and suggesting specific factors, such as proteases, in the extracellular environment. The starting point of phagocytic activity reflects a biological capacity for distinguishing between self and nonself. Thus, the phagocytosis of yeast by mesenchymal cells beginning in the mid-gastrula stage in L. variegatus may indicate the moment of acquisition of 'identity' (self) in this organism. Comparative aspects of embryo and adult phagocytes in L. variegatus are also discussed.

Effect of coconut water and Braun-Collins solutions at different temperatures and incubation times on the morphology of goat preantral follicles preserved in vitro

Preservation of preantral follicles becomes very important to ensure follicle quality at the onset of cryopreservation or in vitro culture. However, for domestic animals, the ovarian donor of preantral follicles for in vitro studies is commonly encountered far away from reproduction laboratories. We investigated the effectiveness of coconut water and Braun-Collins solutions on the preservation of goat preantral follicles. At the slaughterhouse, the ovarian pair of each animal was divided into 19 fragments. One ovarian fragment was immediately fixed (Control - Time 0). The other 18 fragments were randomly distributed into tubes containing 2 mL of coconut water or Braun-Collins solution at 4 degrees, 20 degrees or 39 degrees C and then stored for 4, 12 or 24 h. Histological analysis showed that the storage of ovarian fragments in coconut water and Braun-Collins solutions at 20 degrees or 39 degrees C for 12 or 24 h significantly reduced (P < 0.05) the percentage of morphologically normal preantral follicles when compared with the control. However, storage in coconut water at 20 degrees C for 4 h and in both solutions at 4 degrees C kept the percentage at control values. Ultrastructural analysis of follicles exposed to the stated conditions confirmed the integrity of preantral follicles stored at 4 degrees C in Braun-Collins and coconut water solutions for up to 12 and 24 h, respectively. Reduced cellular metabolism at 4 degrees C may explain why the best preservation of preantral follicles was at 4 degrees C, which may suggest a useful method for ovary transport in the future.

Haemozoin formation in the midgut of the blood-sucking insect Rhodnius prolixus

Malaria parasites digest haemoglobin and detoxify the free haem by its sequestration into an insoluble dark-brown pigment known as haemozoin (Hz). Until recently, this pigment could be found only in Plasmodium parasites. However, we have shown that Hz is also present in the midgut of the blood-sucking insect Rhodnius prolixus [Oliveira et al. (1999) Nature 400, 517-518]. Here we show that Hz synthesis in the midgut of this insect is promoted by a particulate fraction from intestine lumen. Haem aggregation activity is heat-labile and is inhibited in vitro by chloroquine (CLQ). Inhibition of Hz formation in vivo by feeding insects with CLQ leads to increased levels of haem in the haemolymph of the insect, which resulted in increased lipid peroxidation. Taken together, these results indicate that a factor capable of promoting Hz crystallisation is present in R. prolixus midgut and that this activity represents an important physiological defence of this insect against haem toxicity.

Anti-inflammatory and analgesic activities of the latex containing triterpenes from Himatanthus sucuuba

Some triterpenes and iridoids were previously isolated from the stem bark of Himatanthus sucuuba. The latex from Himatanthus sucuuba is used in popular amazonian medicine as an anti-inflammatory remedy. Fractions of the latex were pharmacologically evaluated with a view to verify this popular use in the carrageenan-induced rat paw edema and in the acetic acid-induced mouse constriction tests. The hexane fraction inhibited the edema formation by 35.9% at a dose of 200 mg/kg (p.o.) but no activity was observed at 100 mg/kg (p.o.). The triterpenes present in the hexane fraction were identified as lupeol acetate, alpha-amyrin and lupeol cinnamates. The fraction containing only cinnamates inhibited the edema and the abdominal constrictions by 50-40% and 57.9%, respectively, at 100 mg/kg (p.o.). Among all the fractions studied, the fraction containing only cinnamates showed the greatest anti-inflammatory activity which suggests that these compounds were responsible for the previously described activity of the crude extract.

Induced inflammatory process in Peripatus acacioi Marcus et Marcus (Onychophora)

The inflammatory response induced by the implant of a suture thread in Peripatus acacioi muscle was characterized under light and transmission electron microscopy (TEM). After 24 and 48 h granulocytes were observed migrating through the connective tissue toward the suture thread. These cells contain cytoplasmic eosinophilic granules as well as free granules near to the thread. There were few spherule cells with eccentric smooth kidney-shaped acidophilic nuclei and basophilic granules. Cells with intermediary characteristics as well as cells with a central basophilic nucleus with scarce acidophilic cytoplasm devoid of granules were also found. Under TEM, the granulocytic coelomocytes show small and homogeneous electron dense granules, while the spherule cells possess spherules that can be heterogeneous, granular, or with myelin figures. An acute induced inflammatory process is described for the first time in Onychophora and contributes to the scarce available literature on the function of the coelomocytes within this group.

Epidermal glands in Squamata: microscopical examination of precloacal glands in Amphisbaena alba (Amphisbaenia, Amphisbaenidae)

The femoral or cloacal region of many species of lizards and amphisbaenians exhibits epidermal glands. The pores of these glands are plugged with holocrine solid secretions that serve as semiochemical sources. Many authors assume that these glands are mainly associated with reproduction and demarcation of territory. The structure of precloacal glands in Amphisbaena alba was previously studied by Antoniazzi et al. (Zoomorphology 113:199-203, 1993; J. Morphol. 221:101-109, 1994). These authors suggested that as the animal moves inside tunnels, the secretion plugs are abraded against the substrate, releasing a secretion trail. Some aspects of the plug were difficult to interpret in fine sections due to the dense and brittle nature of the plug. The morphology of the trail, and the manner of deposition on the substrate, have never been reported. This study presents a primarily scanning electron microscopic description of A. alba precloacal glands and of the secretion plugs. It also demonstrates experimentally the formation of the trail and its fine morphology. The results show that when the plugs scrape against the substrate, their constitution helps them to fragment into tiny pieces, which are spread on the ground, thus forming a trail. Each one of the fragments corresponds to a secretion granule of the precloacal gland's secretory cells. In this way, the trail might have an extensive area for volatilization of semiochemicals, constituting an efficient means of intraspecific communication inside the tunnels.

Study of preantral follicle population in situ and after mechanical isolation from caprine ovaries at different reproductive stages

The purposes of this study were to estimate the population of caprine preantral follicles, and to evaluate quantitatively and qualitatively the efficiency of a specific mechanical method for the isolation of preantral follicles from mixed breed goats at different reproductive stages. On average, 37,646+/-4277 preantral follicles were present in goat ovaries, and 13,631+/-2399 preantral follicles were obtained after isolation. The number of preantral follicles isolated or in situ was not significantly affected by the reproductive stage. The mean recovery rate per ovary ([number of isolated follicles/number of in situ follicles] x 100) of isolated follicles was 36.2%. The distribution of follicles in situ was 67.8% primordial, 25.8% primary and 6.4% secondary; the respective distribution after isolation was 93.8%, 5.2% and 1.0%. In this study, many polyovular follicles were also observed, mainly in prepubertal goat ovaries. Histological analysis showed that few preantral follicles were atretic in situ (4.83%+/-0.35) or after the isolation procedure (4.67%+/-0.65) in the three reproductive stages. The percentage of atretic follicles was not affected either by the mechanical method or by the reproductive stage. It is concluded that a large number of preantral follicles can be successfully isolated mechanically, with a high recovery rate and a low rate of follicular atresia, irrespective of the reproductive stage of the caprine female.

[Epizootic outbreaks of trichinosis in 2 pig farms from the Metropolitan Region of Chile]

In Chile swine trichinosis has presented a progressive decreasing in the last two decades of XX century. T. spiralis pig infection descended from an average of 0.683 per 1000 in 1980-1984 to 0.315 in 1985-1989 and to 0.115 in 1990-1996. In the particular case of Metropolitan Region this decreasing has been more marked: from an average of 0.058 per 1000 in 1990-1994 to 0.003 in 1995-1999. Between the end of June 1999 and middle January 2000 in Metropolitan Region abattoirs T. spiralis was detected in 15 (4.9%) out of 306 swine from two pigsties located in El Monte (E.M.) and Padre Hurtado (P.H.) 45 and 30 km south-west from Santiago. In the same period another four pigs from the same premises were found infected in abattoirs of other regions. During inspection visits it was stated that both pig farms had deficient sanitary conditions. Phototrichinoscopy was positive in three out of five Rattus norvegicus collected in E.M. In pigsty PH the examination of diaphragm samples of 25 dogs and 17 cats resulted negative. In the premises originating T. spirali infected swine the Metropolitan Environmental Health Service Abattoirs Program carries out an epidemiological vigilance consisting in the follow-up of animals destined for slaughtering in order to initiate prophylactic actions oriented to eliminate eventual sources of trichinosis infection for human and rearing pigs.

Effect of the interval of serial sections of ovarian tissue in the tissue chopper on the number of isolated caprine preantral follicles

The present work investigated the effect of the interval of serial sections of ovarian tissue on the number of isolated preantral follicles in the goat. Goat ovaries were cut in the tissue chopper at eight different intervals. The quality of isolated follicles were evaluated by histology and transmission electron microscopy. Best results were obtained when the ovaries were cut in the tissue chopper at intervals of 75.0 microm (9664 preantral follicles per ovary). Histochemical and ultrastructural analysis showed that the follicular morphology was preserved after mechanical isolation as demonstrated by the normality of oocytes and granulosa cells as well as by preservation of basement membrane. The percentages of isolated primordial, primary and secondary follicles were 96.3%, 2.5%, and 1.2% and their average diameters were 21.5, 34.7 and 65.3 microm, respectively. It was concluded that the interval of serial sections of ovarian tissue in the tissue chopper affects the number of isolated preantral follicles, and that the follicles remained intact after mechanical isolation in goats.

Wound repair in the Amphioxus (Branchiostoma platae), an animal deprived of inflammatory phagocytes

The existence of phagocytes in the Amphioxus is a matter of debate since early studies of Metchnikoff, who could not induce inflammation in this animal. To reinvestigate this important phenomenon, we sectioned the distal portion of the animal and analyzed, by morphological methods, the presence of phagocytes in the wound. The analysis of the wound by optical and electron microscopy did not detect cells with morphological characteristics of phagocytes in it. The wound is completely covered by the external cuticle of the animal 24 hr after the lesion was made. A second section of the animal leads to abnormal healing of the lesion. The insertion of a surgical silk thread in the muscle of the animals results--after 13 days--in a collection of cells surrounding the foreign body. The ultrastructural analysis of these cells showed they are endothelial cells rather than specialized phagocytes. Yet, the Amphioxus is able to mount an allograph rejection when the animals are tied together by suture. This intriguing capacity of the Amphioxus to cope with tissue healing, infection, and other pathologies without phagocytes is discussed.

Absorption of intra-bronchial diprophylline-methodology and preliminary results

With the objective of measuring alveolo-capillary permeability, a diprophylline solution (molecular weight 254 D) was instilled as a bolus. Instillation was performed through distallized impacted fiber bronchoscope and 3 normal volunteers and 3 patients with pulmonary fibrosis were evaluated. Blood samples were collected at regular intervals with subsequent pharmacokinetic study, mainly aimed at determining absorption kinetics. This technique enabled us to distinguish the two groups of individuals which had different absorption rates. In controls, kinetics apparently followed a simple, one compartment model for absorption, which was slower and occurred to a lesser extent. Patients with a pulmonary fibrosis had a faster and higher degree of absorption, with a larger plasma Cmax. In the latter group two-compartment kinetics for absorption was found. We conclude that absorption kinetic parameters can disclose data on structural integrity of epithelia and possible lesions of the lung interstitium.

Congenital dislocation of the knee

Congenital dislocation of the knee (CDK), first described in 1922, is a rare condition sometimes associated with other congenital malformations. There is a total anterior dislocation with recurvatum and upward displacement of the proximal tibia. This review covers our ten year experience at the hospital San Juan de Dios, in Caracas, Venezuela, a children's hospital with three orthopaedic services. We have seen 22 affected knees in 14 patients. Newborn patients were treated on traction until reduction was achieved, followed by serial plaster of Paris casts until, optimally, 90 degrees of flexion was gained. Surgical treatment was used if conservative treatment had failed after six months, or if the patient first presented after the age of 12 months. All our patients were eventually able to walk, three with the assistance of calipers. Some limitation of knee flexion was commonly seen. The best results were achieved when treatment was started early.

The immunological component of the cellular inflammatory infiltrate in bronchiectasis

Immunohistological analysis of bronchial biopsy specimens from nine patients with bronchiectasis and four control subjects was performed with a panel of monoclonal antibodies selected to show lymphocyte and macrophage subsets and signs of cellular activation. The cells taking part in the inflammatory response in the bronchial wall of patients with bronchiectasis were almost exclusively mononuclear cells, most of them T lymphocytes. B lymphocytes were observed in biopsy specimens from only two out of nine patients. CD8+ T cells outnumbered CD4+ cells in all patients in a ratio ranging from 2:1 to 10:1. Most T lymphocytes also strongly expressed CD7 antigen and a proportion of them expressed HLA-DR. Most of the lymphocytic infiltration occurred just beneath the basement membrane of the epithelium, though intraepithelial and submucosal infiltration was also seen. Non-lymphoid mononuclear cells expressing the phenotype of dendritic cells and macrophages were found dispersed throughout the infiltrate, most of them expressing HLA-DR. These observations support the hypothesis that cell mediated immunological reactions contribute to the inflammation associated with bronchiectasis.

The effect of experimental induced hypocalcaemia on uterine activity in the sow during parturition and post-partum

Uterine activity was measured by monitoring intrauterine pressure changes using ballon-tipped catheters placed in the lumen. An infusion rate of Na(2)EDTA of 35 mg/Kg/h gave a chelation rate equivalent to the rate of calcium mobilisation, and when infused at a level greater than this, resulted in a reduction in plasma calcium concentrations and a concomitant reduction in uterine activity. In three of the four sows infused intrapartum, there was complete cessation of uterine activity; however, plasma calcium concentrations of less than 6 mg 100 ml resulted in a reduction in uterine activity at this stage of parturition. The uterus of the sow post-partum appeared to be more sensitive to the effects of hypocalcaemia with reduced uterine activity when plasma calcium concentrations fell below 8.2 mg 100 ml and complete cessation of activity between 6 and 7 mg 100 ml . Although there was evidence of a delay in the expulsion of piglets in the hypocalcaemic sows, there was no evidence of an increased number of stillborn piglets compared with the two control sows.

Effect of a first-trial cue on spontaneous recovery by moderately mentally retarded adults

The effect of a distinctive first-trial cue on the degree of spontaneous recovery of moderately mentally retarded adults was investigated. The group given the cue showed more recovery of the operant response than did control groups for disinhibition on unextinguished discriminative stimulus. The group receiving the conventional procedure to produce spontaneous recovery, however, displayed significantly greater recovery than did any of the other groups. There was thus limited support for the hypothesis that cues associated with the first trial of a training session have greater significance for learners than do other cues.