Teratological examination of the insecticide methylparathion /Wofatox 50 EC/ on pheasant embryos. 1. Morphological study

Teratogenic effects of methylparathion /Wofatox 50 EC/ and Parathion 20 WP as positive control material were tested in pheasant embryos. On the 12th day of incubation 0.1 ml of the emulsions or suspensions of the insecticides at different concentrations was inoculated into the air space of embryonated eggs. The following dose levels were employed: 27 and 270 mg/kg egg of Wofatox 50 EC, and 10 mg/kg of Parathion 20 WP.Morphological changes were evaluated by macroscopic, skeletal staining and light microscopic examinations of the embryos. Primary hypoplasia or atrophy developed in the cervical musculature /m. longus colli/ accompanied by lordosis and scoliosis of the cervical spine. In most cases we also found cyllosis.     

Teratological examination of the insecticide methyl-parathion (Wofatox 50 EC) on pheasant embryos. 2. Biochemical study.

Fertile pheasant's eggs were treated with the insecticide Wofatox 50 EC (50% methyl-parathion) by injection technique on day 12 of the hatching period. Treatment consisted of inoculation of 0.1 ml of different concentrations of the insecticide into the air space of embryonated eggs. The following dose levels were employed: 0.00, 1.35, 13.5 and 135.0 mg/kg egg of active ingredient. Biochemical changes in the plasma were evaluated by micro (photometric) methods which rendered possible the determination of several blood plasma variables of the embryos. At the highest dose level applied, serum alkaline phosphatase (SAP) enzyme activity and inorganic P concentration of the treated embryos showed statistically differences (reduction) as compared to the control data. Macroscopic alterations were detected at necropsy.     

Model field study of Sumithion 50 EC and Fusilade S on pheasants.

Toxicological studies on wild animals play an important role in the ecotoxicological examination of pesticides. The applied model tests enable the assessment of toxicological consequences with particular regard to the life and nutrition of wild animals in the ploughed field among plants treated with pesticides. The application of different pesticide formulations on plough-land may pose a simultaneous chemical burden to wild birds. In this model study, manifestations of the interaction between an insecticide and a herbicide were studied in pheasants. The birds were placed on lucerne in cages (48 m2) and sprayed once. The applied doses were: Sumithion 50 EC 1 litre/ha + Fusilade S 6 litres/ha (practical doses) and Sumithion 50 EC 5 litres/ha + Fusilade S 30 litres/ha. The analytically determined pesticide concentration of the lucerne was taken as a basis in the further treatment of fodder. The fodder of pheasants contained the following chemicals: 85 mg/kg Sumithion 50 EC + 510 mg/kg Fusilade S and 425 mg/kg Sumithion 50 EC + 2250 mg/kg Fusilade S. Sporadic deaths observed among the pheasants were of traumatic origin and not due to a toxic effect. The decrease of body weight was significant only at the higher dose levels. Acetylcholinesterase (AChE) activity of the blood decreased significantly in both dose groups. On the basis of the results obtained it can be established that at the dose level used in the practice the pesticides studied do not give rise to a toxic interaction in pheasants.     

Morphological examination of the intraorbital muscles (musculi bulbi) in dogs in the perinatal period

Twelve American Staffordshire terriers, gestational day 60, and 10 dogs de Bordeaux, gestational day 57 were examined in respect of the morphology and morphometry of their intraorbital muscles. The location of the retractor bulbi, recti and oblique muscles was described and the length of the muscles, the length and breadth of their tendons as well as the distance of the distal insertions of the muscle tendons from the corneal limbus were measured. Similarly, the shape of the line of distal insertions was investigated. The measurements were taken with an electronic caliper to the nearest 0.1 mm. The distance insertion-corneal limbus was measured by means of the Hifny and Misk method (1982). The following differences between the breeds in the morphometry of the intraorbital muscles and their tendons were found out. The distal insertions of the tendons of the dorsal, ventral and lateral recti muscles are further from the corneal limbus in American Staffordshire terriers than in dogs de Bordeaux. The muscular funiculi of the retractor bulbi muscle are further from the corneal limbus in dogs de Bordeaux, except the dorsolateral funiculus (1.96/1.94 mm). In addition, there are differences in the morphometry of the intraorbital muscles and their tendons. No differences, however, were found in the morphology of the intraorbital muscle tendons (their insertion line) and their location. The study can be applied to clinical sciences (surgery) and veterinary ophthalmology, in particular.     

Teratogenicity testing of BI 58 EC (38% dimethoate) in chicken embryos with special respect to degradation of the active ingredient.

The insecticide formulation BI 58 EC was tested for teratogenicity in chicken embryos, with particular reference to degradation of the active ingredient (dimethoate) after the treatment of embryonated eggs. The pesticide was diluted in water to a concentration level of 0.8%, and the emulsion was injected into the air space in a volume of 0.1 ml/egg, or hen's eggs were treated by the immersion technique. Residues of dimethoate were measured in the samples on days, 13, 15 and 19 of the incubation of chicken embryos, and morphological examinations were performed simultaneously. Analytical chemistry data indicated a slower degradation of dimethoate in embryos after the immersion of eggs, and cyllosis was remarkable in this group among the sporadic developmental anomalies. The liver tissues of both treated groups exhibited severe fatty infiltration.     

Morphological examination of the intraorbital muscles (musculi bulbi) in Persian cats in the perinatal period

The study involved 34 fetuses of Persian cats from eight uteruses, gestational day 58. The intraorbital muscles were analysed morphologically in respect of the location of the recti muscles, oblique muscles and retractor bulbi muscle, their length and breadth, the distance of the muscle tendon insertions from the corneal limbus and the line of insertions.     

Morphological study of the Forestomach of the Japanese Serow (Capricomis crispus)

Details of the morphology of the forestomach of the Japanese serow (Capricornis crispus) were examined macroscopically, and by light and scanning electron microscopy. The rumen was sac-like in shape, and the right accessory longitudinal groove was not visible externally. The reticulum was relatively small, while the omasum was oval and large. Inside the rumen, even in the dorsal sac, the ruminal papillae were densely distributed, although absent on the pillars. The caudodorsal coronary pillar was indistinct. In the ruminoreticular fold, ruminal papillae were observed even on the reticulum side. In the reticulum, the primary reticular fold was apparent and the ill-defined secondary folds were also detected in some reticular cells. In the omasum, the omasal laminae of four sizes were recognized. The fourth order of laminae was occasionally absent. Histological sections of ruminal papillae revealed that softly keratinized epithelium covered the entire ruminal mucosa. In the reticulum, soft keratinized epithelium was observed throughout, with the exception of the tips of reticular papillae on which the epithelium showed evidence of hard keratinization. The epithelium of the omasal laminae was moderately keratinized. On the floor of the reticular groove, interlaminar area and in the omasal groove, the accumulations of numerous eosinophilic cells were observed in the superficial region. Under the scanning electron microscope, shallow transverse grooves were seen on the surface of the ruminal papillae. In general, the surface structure seemed to be similar to that of sheep rather than cattle. Cellular formations of the collagen fibrils were observed at the subepithelial region. In conclusion, examination of the forestomach allows classification of the Japanese serows as requiring an intermediate type of feeding habit and being between concentrate selectors and grass-roughage eaters from a morphological view.     

Morphological study on the stomach of the lesser mouse deer (Tragulus javanicus) with special reference to the internal surface.

The stomach of the lesser mouse deer (Tragulus javanicus) was observed macroscopically. It consisted of only three compartments, rumen, reticulum and abomasum without omasum. The rumen was S-shaped with large ventral and caudoventral blind sacs and the reticulum was larger than the abomasum. Internally, the rumen was covered with numerous ruminal papillae even on the pillars and the ruminoreticular fold. These papillae were leaf- or tongue-like shaped and varied in size and density. The reticulum had honey-combed crests and the secondary crests were found rarely. The lips of the reticular groove were prominent and more developed in the aboral part than in the oral one. A sac-like transition zone, which had more prominent mucosal folds than had the floor of the reticular groove, was observed between the caudal end of the reticular groove and the abomasum. Mucosal folds of the abomasum were spiral, low but rather thick. These findings were discussed in view of comparison with other ruminants and of possible functional implications.     

Trials with chlorpyrifos (Dursban) as a systemic insecticide against the cattle louse.

Data for louse control are presented chiefly on chlorpyrifos (Dursban) 0, 0-diethyl 0-(3, 5, 6-trichloro-2-pyridyl) phosphorothioate and fenchlorphos in one trial and chlorpyrifos and famphur in three trials. These animal systemics were tested on 168 dairy calves in four herds located in three regions of the North Island, New Zealand. Louse control, following single backline, dermal applications, showed 80%, 87% and 100% with dosages of chlorpyrifos at 5 mg, 13 mg and 20 to 200 mg per kg, respectively, and 100% and 93% with dosages of famphur at 20 mg per kg, respectively. Poor louse control (24 to 58%) with fenchlorphos was expected since this compound requires two applications 14 days apart. Ovicidal effect was demonstrated with chlorpyrifos and famphur. Minor scurfing and hair loss occurred on some calves with all compounds, but hair coats were normal 28 days after treatment. Calves given 100 mg to 200 mg per kg chlorpyrifos showed signs of organophosphate toxicity from 5 mins to 90 mins post-treatment but were normal thereafter.     

骆驼斯氏副柔线虫病传播媒介西方角蝇和截脉角蝇各虫态的系统形态学研究

本研究旨在完善西方角蝇和截脉角蝇各虫态的系统形态学资料,为野外采集两种角蝇各虫态样本的分类鉴定提供理论依据,进而为研究斯氏副柔线虫在角蝇体内发育过程,以及制定防控骆驼斯氏副柔线虫病的有效措施等奠定基础。通过实验室人工饲养角蝇,收集西方角蝇和截脉角蝇的卵、各龄幼虫、蛹和成蝇,详细观察并描述两种角蝇各虫态的形态结构,以明确两种角蝇各虫态之间的形态学差异。除西方角蝇和截脉角蝇1龄幼虫外,两种角蝇的卵、2龄幼虫、3龄幼虫、蛹和成蝇都存在可识别的形态学差异。本研究详细描述了西方角蝇和截脉角蝇各虫态的形态特征,并确定了多处可用于区分两种角蝇卵、2龄幼虫、3龄幼虫、蛹和成蝇的形态特征差异。     

东北委陵菜属植物叶形态结构的研究及其分类学价值的探讨

首次采用了GMA半薄切片法对委陵菜属23种植物叶的形态结构进行了比较形态学研究。结果表明,东北委陵菜属植物的托叶类型多样,分为披针形、卵状披针形、卵圆形和叶状;叶柄横切面多为心形,此外还有马蹄形、近三角形和近圆形,维管束常为3个;叶表皮具腺毛和非腺毛;气孔均为无规则型,主要分布在下表皮;多数物种具韧皮纤维。本属木本植物金露梅及银露梅叶的许多特征(如毛状体类型,维管束数量及结构)与草本物种相似,故支持前人将二者放在委陵菜属。本研究可为委陵菜属的分类提供形态学依据,并为进一步深入研究中国委陵菜属以及蔷薇科的分类及系统学提供重要的基础资料。     

Morphological studies on the heart ventricle of African catfish (Clarias gariepinus)

The histological and ultrastructural characteristics of the heart ventricle in Clarias gariepinus (African catfish) has been studied by light microscopy and transmission electron microscopy. The ventricle of the heart has a saccular shape and the myocardial wall consists of an outer thin compact myocardium and an inner well-developed spongy myocardium. The myocardial layer has small myocytes, interstitial spaces and blood vessels. The myocytes are the major constituents of the ventricular wall. They are long cells, with large nuclei, and predominantly euchromatin. The sarcoplasmic reticulum of the ventricular myocytes consists of a network of tubules and subsarcolemmal cisternae oriented mainly along the longitudinal axis of the myofibrils. In contrast to the ventricular structure of other fish species described in the literature (Greer-Walker et al., 1985; Santer, 1985; Sánchez-Quintana et al., 1995, 1996), the African catfish, a freshwater sedentary fish recently introduced in neotropical climatic environments, showed a saccular ventricle that consisted of two muscle layers, a thin compact layer with large vessels and a developed spongy layer. The ultrastructure of the ventricular myocardium of C.gariepinus is similar to that of other teleosts, inclusive that of fish with other swimming habits.