Ultrastructural features of atretic follicles in the sexually immature ostrich (Struthio camelus)

The aim of this study was to describe the ultrastructural features of atresia in follicles of the immature ostrich (12–14 months old); a ratite that displays seasonal, precocious ovarian activity. The early stage of atresia in primordial, pre-vitellogenic and vitellogenic follicles was characterized by the accumulation of lipid droplets in the granulosa cells. Granulosa cells with condensed cytoplasm and nuclei were a prominent feature during the intermediate phase of atresia. The degenerating follicles were then infiltrated by stroma during the terminal stages of atresia. The results of this study provide further information on the morphology of atretic ovarian follicles in the immature ostrich.     

Excluding infants under 6 months of age from surveys: impact on prevalence of pre-school undernutrition

OBJECTIVE: Infants aged 0-5 months are not systematically included in assessments of child nutritional status and are generally excluded from surveys conducted in emergencies. We estimated the impact of excluding 0-5-month-old infants on the prevalence of stunting, wasting and underweight among children under 5 years (U5) and under 3 years (U3) of age. DESIGN: Comparison of the prevalence of stunting, wasting and underweight in U5 and U3 with or without inclusion of the age group 0-5 months. SETTING: Demographic and Health Surveys and Multiple Indicator Cluster Surveys from 76 developing countries and countries in transition. SUBJECTS: Children under 3 or under 5 years of age included in the surveys.Results Excluding 0-5-month-old infants resulted in an overestimation of the prevalence of stunting, wasting and underweight in U5 of 3.0, 0.3 and 2.6 percentage points, respectively, and of 4.8, 1.0 and 5.2 percentage points, respectively, in U3. The overestimation for wasting was negligible. The regions showing the highest overestimations for stunting and underweight were Asia and sub-Saharan Africa. Overall, countries with high prevalences of stunting and underweight showed especially large overestimations. The prevalence of underweight in infants aged 0-5 months was correlated with the prevalence of low maternal body mass index. CONCLUSION: All surveys, even in situations of nutrition emergency, should include 0-5-month-old infants. Strictly comparable age ranges are essential in nutrition surveys for monitoring trends and evaluating programme impact. Greater awareness of prenatal and early child undernutrition is needed among policy-makers.     

A morphological and immunohistochemical study of healthy and atretic follicles in the ovary of the sexually immature ostrich (Struthio camelus)

The morphology of healthy and atretic follicles in the ovary of the sexually immature ostrich was described in the present study. In addition, the distribution of the intermediate filaments desmin, vimentin and smooth muscle actin, in these ovarian follicles, was demonstrated. Healthy and atretic primordial, pre-vitellogenic and vitellogenic follicles were present in the ovaries of the sexually immature ostrich. Atresia occurred during all stages of follicular development. Atretic primordial and pre-vitellogenic follicles were characterized by the presence of a shrunken oocyte surrounded by a multilayered granulosa cell layer. Two forms of atresia (types 1 and 2) were identified in vitellogenic follicles. In the advanced stages of type 1 atresia the follicle was dominated by a hyalinized mass. In contrast, in type 2 atresia the granulosa and theca interna cells differentiated into interstitial gland cells. Positive immunostaining for desmin was observed in the granulosa cells of only healthy primordial and pre-vitellogenic follicles. Atretic primordial and pre-vitellogenic follicles were immunonegative for desmin. Vimentin immunoreactivity was demonstrated in the granulosa cells of all follicles except the vitellogenic atretic follicles. The results of the present study indicate that ovarian follicles in the sexually immature ostrich undergo a cycle of growth and regression, which is similar to that reported in other avian species. Furthermore, based on the results of the immunohistochemical study, it would appear that the distribution and immunostaining of intermediate filaments changes during follicular development and atresia.     

Efficacy of selamectin administered topically in the treatment of feline otoacariosis

The efficacy of a novel avermectin, selamectin (Stronghold, Pfizer), was evaluated against naturally acquired aural infestations of Otodectes cynotis. Selamectin was administered topically in a single spot to the skin of each animal's back at the base of the neck in front of the scapulae at a minimum dosage of 6mgkg(-1). Thirty cats of a cattery of 120 animals with an endemic infestation were treated on days 0 and 30. Including untreated control cats was therefore not possible because of animal welfare consideration. Clinical examination and visualization of mites by otoscopic examination of the external ear canal and microscopic examination of aural debris/exudate were performed twice weekly from days 0 to 30. On day 0 (and day 28 if the ears canals were erythematous), a swab was taken from each canal and sent to bacteriology and mycology units for detection and identification of bacteria (Staphylococcus mainly) and yeast (Malassezia pachydermatis only).Selamectin was safe, parasites were killed before day 3 and eliminated before day 17. Selamectin was 100% effective against natural aural infestations, even if erythema (26-33% of cats) and scratch reflex (23-40% of cats) persisted for 2 weeks after the cats tested negative for mites.     

Morphological features of the luminal surface of the magnum in the sexually immature ostrich (Struthio camelus)

Summary Observations were made, using scanning electron microscopy, of the surface features of the magnum in the immature ostrich during periods of ovarian inactivity, activity and regression. In birds with inactive ovaries the luminal surface of the magnum was lined with non-ciliated cells, which were densely covered by microvilli. In contrast, the magnum in birds with active ovaries was composed of ciliated and non-ciliated cells. The distribution of ciliated cells was not uniform, with clumps of cilia occurring next to non-ciliated areas. Samples collected from birds with regressing ovaries, during periods of decreasing daylength, revealed that the magnum was undergoing involution. The deciliation of ciliated cells and the presence of short microvilli on non-ciliated cells characterized magnal regression. These results suggest that ovarian activity and changes in daylength have a profound effect on the surface features of the magnum in the immature ostrich.     

Identifying dendroecological growth releases in American beech,jack pine,and white oak: Within-tree sampling strategy

The objective of this project was to identify the timing of growth release events detected from tree ring widths and compare whether two cores taken from the same tree reconstructed the same disturbance history. This research question is important because current dendroecological reconstructions of canopy disturbance rely on sampling one core per tree; however, the variation of releases from different cores from the same tree has never been evaluated. We sampled two increment cores from 20 jack pine, 17 white oak, and 19 American beech and identified release events with two commonly employed methods: radial growth averaging technique and boundary line criteria. In jack pine, 85% of the paired cores showed identical releases with the radial growth averaging technique, but 15% of the paired cores varied in reconstructed growth releases. In the jack pine, no releases were identified with the boundary line criteria for any of the paired cores. In the white oak, 65% had identical releases identified with the radial growth averaging technique and 35% of the pairs showed differences. The boundary line criteria for white oak had agreement between releases for 76% of the pairs and different release histories for 24% of the pairs. In the American beech, we were only able to use the radial growth averaging technique and this method showed identical release timing for 79% of the paired cores and differences in 21% of the paired cores. This level of within-tree growth variation is unlikely to influence identification of stand-wide disturbances; however, for reconstructions of small-scale disturbances it is likely to under-represent disturbance events. Therefore, for small-scale disturbance reconstructions, we recommend dendroecologists consider sampling two cores per tree instead of the standard sample of one core per tree.     

Assessing Passive Capillary-Wick Samplers for monitoring resident nitrate concentration in real field

Abstract. We evaluated the effectiveness of capillary-wick samplers (PCAPS) for continuous monitoring of resident nitrate concentration in three 'soil-crop-climate' systems differing in soil type, land use and climate. These systems involved: (i) acid silty soils under a beech-oak forest affected by heavy N-NH₄⁺ deposition in Belgium; (ii) silty soils under wheat cropping and a short rotation willow coppice plantation (SRC) in Belgium; and (iii) volcanic ash soils under plantain cultivation with and without urea fertilization in Colombia. The PCAPS continuously applied a suction of 0 to 5.4 kPa to the soil water below the effective rooting zone without the need for an auxiliary vacuum source. The nitrate concentrations showed large variations over time and ranged between 6–192 mg l^–1 under forest, 19–143 mg l^–1 under wheat, 11–47 mg l^–1 under SRC and 3–138 mg l^–1 under fertilized plantain. The analysis of the soil leachates collected with PCAPS confirms previous results dealing with leaching of nitrate and alkaline and alkaline-earth cations in similar 'soil-crop-climate' systems. It was concluded that PCAPS was a suitable tool to collect soil solutions and that it could help to assess nitrate leaching losses in various ecological or cropping conditions.     

An immunohistochemical study of ovarian follicle histogenesis in the early post-hatch Japanese quail (Coturnix coturnix japonica)

The early post-hatch development of immunoreactivity to vimentin, desmin, smooth muscle actin (SMA) and laminin, in relation to follicle histogenesis, was described in this study. Ovigerous cords in day old quails contained pre-granulosa cells and oocytes. Pre-granulosa cells at the cortico-medullary junction were vimentin immunopositive. A laminin immunopositive basement membrane and desmin immunopositive mesenchymal cells lined the ovigerous cords. Ovigerous cords in 3-day-old quails contained developing primordial follicles, the vimentin immunopositive pre-granulosa cells of which were partially encircled by a basement membrane and desmin immunopositive mesenchymal cells. In 5- to 7-day-old quails, ovigerous cords formed an outer cortical region, while primordial follicles formed the inner cortical region. Early pre-vitellogenic follicles were present in 9- to 13-day-old quails. Underlying the granulosa cells of these follicles was a laminin immunopositive basement membrane and a layer of desmin immunopositive thecal cells. Early and late pre-vitellogenic follicles dominated the ovary in 15- to 17-day-old quails. The thecal layer in these follicles was desmin immunopositive, but SMA immunonegative. The results of the study have shown that the process of primordial follicle development in the Japanese quail is similar to that reported in mammals. The study suggests that in the quail pre-granulosa cells originate predominantly from the medulla. The study has shown that, in the Japanese quail, thecal cells are derived from desmin immunopositive mesenchymal cells lining the ovigerous cords.     

Evaluation of crude palm oil and refined palm olein as dietary lipids in pelleted feeds for a tropical bagrid catfish Mystus nemurus (Cuvier & Valenciennes)

The effects of different dietary lipids on the growth, feed utilization and tissue fatty acid composition of a tropical bagrid catfish Mystus nemurus (Cuvier & Valenciennes) were investigated. Eight isonitrogenous and isoenergetic semi‐purified diets were fed to triplicate groups of M. nemurus fingerlings for 10 weeks. Diet lipid levels were fixed at 10%, with 1% coming from residual oil in fishmeal and the remainder from cod liver oil (CLO), corn oil (CORN), soybean oil (SBO), crude palm oil (CPO), refined, bleached and deodorized palm olein (RBDPO) or various combinations of these oils. Catfish fed diets supplemented with 9% RBDPO showed significantly (P < 0.05) higher growth rates compared with fish fed the other seven diets. No significant differences in growth performance or feed efficiency ratio were observed between M. nemurus fed 9% CLO, CORN or CPO or fish fed diets containing 4% CLO with either 5% CORN, SBO, CPO or RBDPO. Based upon these results, palm oil‐based diets can be used effectively for M. nemurus without compromising growth or feed utilization efficiency. Muscle and liver fatty acid composition of M. nemurus reflected that of the dietary oils added in pelleted diets fed to the fish. Considering the lower cost and availability of palm oil (compared with imported vegetable oils and fish oils) in many tropical countries, its use in dietary formulations for M. nemurus, and possibly other catfish species, will make these fish feeds less expensive.     

N-acetyl-beta-D-glucosaminidase index as an early biomarker for chronic kidney disease in cats with hyperthyroidism

Background: Hyperthyroid cats are at risk of developing azotemic chronic kidney disease (CKD) and diagnostic tools currently used to screen for CKD in hyperthyroid cats are either unreliable or impractical.
Hypothesis: Urine N -acetyl-β- d -glucosaminidase index (NAG_i) is a good biomarker for azotemic CKD in hyperthyroid cats.
Animals: Twenty-four newly diagnosed nonazotemic hyperthyroid cats and 10 healthy cats.
Methods: All cats were evaluated for hyperthyroidism at baseline. Hyperthyroid cats were treated with methimazole and reevaluated once euthyroid. At the end of the study, cats were divided into 3 groups: healthy cats, nonazotemic, and azotemic euthyroid cats. Baseline group characteristics were compared to predict azotemic CKD. The influence of treatment on NAG_i was evaluated.
Results: Baseline NAG_i was significantly different among groups ( P = .004). Azotemic cats had a higher median value (13.12 U/g) when compared with healthy cats (1.38 U/g). With NAG_i >2.76 U/g, negative and positive predictive values for development of azotemia were 77.7 and 50%, whereas the combination of a urine specific gravity (USG) ≤1.035 and T₄ >7.80 μg/dL enhanced predictive values to 88.9 and 83.3%, respectively. NAG_i values decreased significantly over time in treated nonazotemic cats.
Conclusions and Clinical Relevance: Baseline NAG_i did not differentiate azotemic from nonazotemic euthyroid cats. NAG_i could be used to assess renal function during medical therapy allowing the clinician to adjust methimazole dosage accordingly. The combination of USG and T₄ could optimize identification of appropriate candidates for permanent treatment of hyperthyroidism.