Clinical,ultrasonographic, and endocrinological studies on donkey pregnancy

Although donkey breeding has gained new interest in the past two decades, knowledge about donkey reproduction is still scarce, particularly on jenny pregnancy. The aim of this study was to describe the ultrasonographic and endocrine profiles of the physiological pregnancy in the jenny. The study was performed on 12 pregnancies of 7 Amiata donkeys from Day 10 after ovulation to delivery. Because three pregnancies, respectively at weeks 42, 44, and 45, were considered pathologic and treated pharmacologically, data collected from 2 weeks before diagnosis to the end of pregnancy were removed from the analysis. Average length of the normal pregnancies was 353.4 ± 13.0 days (range, 339–370 days). Timing, dimensions, and development during the first phases of embryonic growth, evaluated using transrectal ultrasound, were similar to that previously described in jennies and mares: first detection of embryonic vesicle was at 11.8 ± 1.3 days of gestation and diameter was 6.5 ± 1.9 mm, loss of spherical shape occurred at 18.5 ± 1.4 days, and embryo and heart beat were first seen at 22.0 ± 1.1 and 25 ± 1.1 days, respectively. The intrauterine growth in the second half of pregnancy, evaluated using the transrectal and transabdominal approach, also showed strong positive correlations, similar to that reported for the mare. The trends of the combined thickness of the utero-placental unit and the echogenicity of the amniotic and allantoic fluids are examples. The diameters (mm) of fetal chest, eye orbit, and aorta increased throughout pregnancy and were 40.6 ± 2.9, 8.7 ± 1.5, and 3.5 ± 0.7, respectively, at week 13, and 190.9 ± 12.0, 21.4 ± 1.5, and 30.6 ± 1.8 at the last evaluation before parturition. In contrast, heart rate decreased as pregnancy progressed. Regression analyses between these parameters and day of gestation were statistically significant (P < 0.001). All fetuses consistently showed some intrauterine activity. Maternal plasma progestagens and estrone sulfate concentrations followed a pattern similar to that seen in mares, although the prepartal progestagen peak was lower in jennies. This study provides a range of ultrasonographic and endocrine values for normal pregnancy in jennies.     

Some morphological aspects of Cylicocyclus brevicapsulatus (Nematoda: Cyathostominae) parasite of horse

This paper describes some morphological aspects of Cylicocyclus brevicapsulatus (Ihle, 1920) (Nematoda: Cyathostominae) from Equus caballus in Brazil. The worms were studied using an optical microscope (measurements and illustrations) and a scanning electron microscope for a more detailed examination of the external morphology. The buccal capsule is very short, with a very thin wall, and the dorsal gutter is absent. Other morphological aspects are described including measurement of the spicules and gubernaculum.     

Demographic and endocrinological aspects of low natural fertility in Highland New Guinea

The Gainj of highland Papua New Guinea do not use contraception but have a total fertility rate of only 4.3 live births/woman, 1 of the lowest ever recorded in a natural fertility setting. Reproductive and marital histories were obtained from 305 females and 206 males aged 10+. Each subject was asked about: number of live born offspring ever produced; number of stillbirths ever produced; number and names of offspring currently being nursed; number of current and past spouses; and the cause of dissolution of all past marriages. Blood samples were drawn from 172 volunteer female subjects aged 10-60 years and ovarian function was classified by concentration of progesterone. From an analysis of these cross-sectional demographic and endocrinological data, the causes of low reproductive output have been identified in women of this population as: late menarche and marriage, a long interval between marriage and 1st birth, a high probability of widowhood at later reproductive ages, low effective fecundability and prolonged lactational amenorrhea. These are combined with near-universal marriage, and a low prevalence of primary sterility similar to that found in other populations. Of all the factors limiting fertility, by far the most important are those involved in birth spacing, especially lactational amenorrhea. The effects of widowhood on Gainj fertility are negligible. Factors acting to lower fertility fall into 2 categories: those that determine the age of onset of reproduction and those that act to space births. Given the observed pattern of birth spacing, however, the delay in commencement of reproduction represents on average no more than 1 or 2 live births averted/woman. In contrast, were age at 1st reproduction held constant while reducing birth intervals to a mean of 2.0-2.5 years, total fertility would increase to about 7 or 8. Future research on natural fertility should focus on specific behavioral and physiological mechanisms governing the reproductive process.     

Age-related morphological and functional changes in the Leydig cells of the horse

Two ultrastructurally distinct types of Leydig cells were observed in the equine testis. Whereas the adult testis exhibited both postpubertal and adult Leydig cells, the testis of the pubertal horse contained only the postpubertal type, and that of the aged horse contained only the adult type. However, Percoll-purified testicular preparations from pubertal, adult, and aged horses all exhibited two distinct Leydig cell populations. The quantitative distribution and the functional characteristics of these Leydig cell populations (ability to bind human chorionic gonadotropin [hCG] and increase of testosterone production after hCG stimulation) evolved with the age of the horse. It is concluded that equine Leydig cells derive from two redundant successive postnatal generations and that there is no strict correlation between the functional properties and the morphological characteristics of these cells.     

Clinical and morphological aspects of shigellosis flexneri in patients with an aggravated premorbid state

The analysis of 10 fatal outcomes in patients with acute shigellosis during the period of 1999-2000 made it possible to find out that most of deceased shigellosis patients belonged to the group inclined to alcohol abuse and having initial alimentary disturbances. In 6 cases of acute shigellosis with fatal outcome the causative agent was S. flexneri 2a, in 2 cases--S. flexneri 3a, in 1--S. flexneri 4b. The main cause of fatal outcomes was accompanying double pneumonia. Lesions of the intestinal tract in deceased shigellosis patients were of destructive character, resulting, in a number of cases, in serous and perforative peritonitis.     

Some biometrical,ecological, morphological and distributional aspects of Chaetognata

The study of the Chaetognatha picked out from 21 plankton samples taken along the Argentinian, Uruguayan and Brazilian coasts, revealed the presence of the following species: Krohnitta pacifica, K. subtilis, Pterosagitta draco, Sagitta bipunctata, S. enflata, S. friderici, S. hexaptera, S. hispida, S. lyra, S. maxima, S. minima, S. planctonis, S. serratodentata, S. tenuis and S. sp. A. All specimens were measured and a complete biometrical table is included. Based on the Chaetognatha and the Thecosomata fauna analyzed by means of the Sorensen's index of similarity between samples, the area is divided into four zones with different hydrological characteristics. There is a distinct relationship between the total length of fully mature specimens and latitude. Based on diagrams, an inter-specific competition between S. enflata and S. t tenuis is suggested. The geographic distribution of K. subtilis and S. planctonis is enlarged.     

Gastrointestinal hormones in birds: morphological, chemical, and developmental aspects

Historically, the enterochromaffin cell was the first endocrine cell type detected in avian gut; subsequently, a number of types of such cells were distinguished on the basis of the ultrastructural features of the secretory granules. More recently, immunocytochemical procedures have revealed somatostatin-, pancreatic polypeptide (PP)-, polypeptide YY-, glucagon-, secretin-, vasoactive intestinal peptide (VIP)-, gastrin-, cholecystokinin-, neurotensin-, bombesin-, substance P-, enkephalin-, motilin-, and FMRFamide-like immunoreactivity in avian gastrointestinal endocrine cells. Most endocrine cells are located in the antrum; there are a number in the proventriculus and small intestine but few in the gizzard, cecum, and rectum. Several avian gastroenteropancreatic hormones, including glucagon, VIP, secretin, bombesin, neurotensin, and PP, have been isolated and sequenced. They resemble the equivalent mammalian peptides in terms of molecular size but differ in amino acid composition and sequence; some (e.g., VIP) differ only in minor respects, others (e.g., secretin) more radically. Gastrointestinal endocrine cells appear late in development; available data indicate that few types are recognized by either immunocytochemistry or electron microscopy before 16 days of incubation. Experimental evidence has shown that at least the majority of gut endocrine cells are of endodermal origin and are not derived from the neural crest or neuroectoderm as earlier proposed. In early embryos, the progenitors of gastrointestinal endocrine cells are more widespread than are the differentiated cells in chicks at hatching. This, along with other observations, raises the question of factors that might influence the differentiation of gut endocrine cells.     

The neuroteratogenicity of procarbazine in the rat: behavioral, morphological, and neurochemical aspects

Pregnant female Sprague-Dawley rats were treated from day 12 through day 15 of gestation with procarbazine, an antineoplastic drug, and their offspring were subjected to tests of locomotor development and behavior. Treatment levels ranged from 0.5 mg/kg/day, a dose that produced no abnormalities, to 10 mg/kg/day, a dose that caused a marked micrencephaly in the absence of other teratological changes. Despite marked morphological brain changes, preweaning locomotor development, as assessed by open-field swimming activity and vertical grid climbing, was normal in all offspring. Post-weaning passive avoidance learning and retention were also normal. Groups that had been treated prenatally with teratogenic doses (5.0 and 10.0 mg/kg/day) displayed less rearing behavior in the open field, while ambulation in the periphery of the open field arena was unaffected. Groups treated with subteratogenic doses (0.5 and 1.0 mg/kg/day) did not differ from control. In addition to the behavioral studies, sodium-dependent high-affinity choline uptake and choline acetyltransferase activity (CAT) were measured (per mg protein) in the cortex and hippocampus of animals that had been exposed prenatally to either teratogenic or subteratogenic doses of procarbazine. In spite of a substantial reduction in size of both brain structures in the group receiving a teratogenic dose, choline uptake and CAT did not differ from control.     

Clinical findings, pathological changes and endocrinological secretory patterns in mares with ovarian tumours.

The clinical, structural and functional characteristics of ovarian tumours were studied in 10 mares. Proliferation of the granulosa cells of large and small follicles and the presence of various numbers of Leydig-like cells in the theca interna were the predominant microscopic findings in 9 of the mares. All 9 of these animals had higher than normal (P less than 0.005) concentrations of testosterone in the peripheral plasma; 2 animals which exhibited male behaviour had testosterone concentrations greater than 100 pg/ml and the largest number of Leydig-like cells in the theca. Mares with lower testosterone concentrations (7/9) exhibited anoestrus or intermittent oestrous behaviour. The predominant microscopic changes in the other mare involved the proliferation of Sertoli-like cells; oestrogen concentrations were highest in this mare. Testosterone values were normal when no Leydig-like cells were observed in the theca. The unaffected ovary of all 10 mares was small and inactive. Eight mares resumed normal cyclic ovarian activity between 115 and 393 days after the removal of the affected ovary.     

Clinical, cytogenetic and molecular evaluation in a dog with bilateral cryptorchidism and hypospadias

The aim of this study was to estimate prognostic factors in a Dalmatian dog with bilateral cryptorchidism and hypospadias. Cytogenetic and molecular analyses revealed a normal karyotype (2n = 78,XY) and the presence of SRY, INSL3 and RXFP2 genes with a normal DNA sequence for SRY and RXFP2, while the INSL3 sequence differed slightly from the normal one due to a heterozygous nucleotide change involving amino acid 22 of the INSL3 dog precursor protein. Levels of plasmatic testosterone were only 0.01 ng/ml, while FSH and LH serum levels were not detectable. After the human chorionic gonadotropin (hCG) test, the serum testosterone level was 0.01 ng/ml. Therefore, the phenotypic aetiology of this subject can not be well-defined because cryptorchidism and hypospadias were frequent clinical features with high genetic heterogeneity.     

Amplified androstenedione enzymeimmunoassay for the diagnosis of cryptorchidism in the male horse: comparison with testosterone and estrone sulphate methods

An amplified enzymeimmunoassay (EIA) was validated for androstenedione in the serum of male horses. We will use the assay as a tool for the diagnosis of equine cryptorchidism. We will compare androstenedione EIA to the currently used methods (testosterone and estrone sulphate determinations). The study was conducted on 115 horses of pure Spanish and Arabian breeds, that included 30 geldings, 60 bilateral cryptorchids and 25 stallions. Androstenedione standard curve covered a range between 0 and 1 ng per well. Low detection limit was 1.54 pg/ml. Intra- and inter-assay coefficients of variation (CV%) were <8.2 and <9.3, respectively (n=10). Recovery rate of known androstenedione concentrations averaged from 96.62+/-2.69 to 97.63+/-1.87%. Androstenedione mean+/-S.E. serum concentrations were 10.52+/-1.36 ng/ml in stallions (n=25), 0.51+/-0.04 ng/ml in cryptorchids (n=60), and 0.03+/-0.01 ng/ml in geldings (n=30). Diagnostic validation parameters in basal samples showed for estrone sulphate the lower positive predictive value (0.85) with the higher number of false positives, and lower specificity (0.84). Testosterone showed the higher number of false negatives with a negative predictive value of 0.85, and lower sensitivity (0.85). Among the three hormones evaluated, androstenedione presented the best results with the smaller number of horses diagnosed as false positives (0.93) or negatives (0.91). This technique also resulted in higher sensitivity, specificity and efficiency over the other two methods assayed. We concluded that our amplified EIA is a highly sensitive and specific assay that provides a rapid, simple, and inexpensive alternative to other methods.     

Physiological,morphological and kinetic aspects of lovastatin biosynthesis by Aspergillus terreus

This review focuses on selected aspects of lovastatin biosynthesis by Aspergillus terreus. Biochemical issues concerning this process are presented to introduce polyketide metabolites, in particular lovastatin. The formation of other than lovastatin polyketide metabolites by A. terreus is also shown, with special attention to (+)-geodin and sulochrin. The core of this review discusses the physiology of A. terreus with regard to the influence of carbon and nitrogen sources, cultivation broth aeration and pH control strategies on fungal growth and product formation. Attention is paid to the supplementation of cultivation media with various compounds, namely vitamins, methionine, butyrolactone I. Next, the analysis of fungal morphology and differentiation of A. terreus mycelium in relation to both lovastatin and to (+)-geodin formation is conferred. Finally, the kinetics of the process, in terms of associated metabolite formation with biomass growth is discussed in relation to published kinetic models. The review concludes with a list of the most important factors affecting lovastatin and (+)-geodin biosynthesis.     

Pedigree analysis and inbreeding effects over morphological traits in Campolina horse population

Genetic improvement, without control of inbreeding, can go to loss of genetic variability, reducing the potential for genetic gains in the domestic populations. The aim of this study was to analyze the population structure and the inbreeding depression in Campolina horses. Phenotype information from 43 465 individuals was analyzed, data provided by the Campolina Breeders Association. A pedigree file containing 107 951 horses was used to connected the phenotyped individuals. The inbreeding coefficient was performed by use of the diagonal of the relationship matrix and the genealogical parameters were computed using proper softwares. The effective population size was estimated based on the rate of inbreeding and census information, and the stratification of the population was verified by the average relationship coefficient between animals born in different regions of Brazil. The effects of inbreeding on morphological traits were made by the use of inbreeding coefficient as a covariate in the model of random regression. The inbreeding coefficient increased from 1990 on, impacting effective population size and, consequently, shrinking genetic variability. The paternal inbreeding was greater than maternal, which may be attributed to the preference for inbred animals in reproduction. The average genetic relationship coefficient of animals born in different states was lower than individuals born within the same state. The increase in the inbreeding coefficient was negatively associated with all studied traits, showing the importance to avoid genetic losses in the long term. Although results do not indicate a severe narrowing of the population until the present date, the average relationship coefficient shows signs of increase, which could cause a drastic reduction in genetic variability if inbred mating is not successfully controlled in the Campolina horse population.     

Embryological aspects of inducible morphological defenses in Daphnia

Many cases of predator-induced morphological plasticity in daphnids are well studied examples of inducible defenses. However, little is known about the early development of these sometimes conspicuous traits. We compared for the first time in five different Daphnia species the embryonic development of predator-induced and noninduced animals using scanning electron microscopy (SEM). We observed significant morphological changes in the last embryonic stage in helmet formation in Daphnia cucullata and in neck-pedestal development in Daphnia pulex. In contrast, no morphological changes could be found during embryogenesis between induced and noninduced Daphnia lumholtzi, D. longicephala, and D. ambigua. Strategies for initiating the defensive traits differ among Daphnia species because of trade-offs between environmental requirements and developmental constraints. Some general features of Daphnia embryonic development are described using SEM. All Daphnia embryos have to shed at least three different membranes before leaving the brood pouch of the mother. After the embryos shed the third membrane, chemosensillae that are likely able to detect predator-released chemicals are exposed to the olfactory environment.     

Cellular and morphological aspects of fibrodysplasia ossificans progressiva

Fibrodysplasia ossificans progressiva (FOP) is a rare congenital disease that causes bone formation within the muscles, tendons, ligaments and connective tissues. There is no cure for this disorder and only treatment of the symptoms is available. The purpose of this study was to review the literature and describe the clinical, cellular and molecular aspects of FOP. The material used for the study was obtained by reviewing scientific articles published in various literature-indexed databases. In view of its rarity and of the lack of insightful information and the unpredictability of its course, FOP is a challenging disorder for professionals who are confronted by it. However, this rare disease raises a great deal of interest because understanding the mechanism of mature bone formation can encourage research lines related to bone regeneration and the prevention of heterotopic ossification.     

Biochemical and morphological aspects of zinc deficiency in rhodotorula gracilis

Summary Cells of Rhodotorula gracilis cultured in a liquid medium containing Zn only as impurity stop growing at a density of about 5·10⁷ cells/ml. The addition of Zn during the prestationary or the stationary phase of growth reestablishes the growth rate, thus showing that Zn⁺⁺ is a limiting factor for growth. An analysis of the changes of the fine structure and of RNA, DNA and protein levels induced by the addition of Zn to Zn-deficient cultures indicates that the most notable features of Zn deficiency are: a) the decrease of net RNA synthesis, and consequently of protein synthesis; b) the appearance of several large vacuole-like structures containing degraded cytoplasmic components, membranous whorls and amorphous material; a decrease in the number of mitochondria and in the organization of cristae. The net synthesis of DNA appears to be much less affected, and lipid synthesis is somewhat stimulated in the Zn-deficient cultures. No important effect of Zn-deficiency was observed on either oxygen uptake or intracellular amino acid level. These results are interpreted as indicating that Zn⁺⁺ is an essential element for this organism, and that the area of RNA metabolism and protein synthesis is the one primarily affected by Zn⁺⁺ deficiency.