Diphenylamine-induced renal papillary necrosis and necrosis of the pars recta in laboratory rodents

The nephrotoxicity of diphenylamine, the parent compound of the mefenamate family of nonsteroidal anti-inflammatory drugs, was evaluated in male Syrian hamsters, male Sprague-Dawley rats, and male Mongolian gerbils. Total renal papillary necrosis was observed in four of ten, seven of ten, and six of ten male Syrian hamsters orally treated with diphenylamine at respective doses of 400 mg/kg body weight/day, 600 mg/kg body weight/day, and 800 mg/kg body weight/day. Total renal papillary necrosis was also observed in five of ten and four of ten male Syrian hamsters intraperitoneally treated with diphenylamine at respective doses of 600 mg/kg body weight/day and 800 mg/kg body weight/day. Focal intermediate renal papillary necrosis was induced in two hamsters orally given diphenylamine at 600 mg/kg body weight/day and in two of ten hamsters intraperitoneally given diphenylamine at 800 mg/kg body weight/day. Apex-limited necrosis of the medullary interstitial cells and vasa recta and degeneration of the renal interstitial matrix occurred in two Sprague-Dawley rats orally administered diphenylamine at 800 mg/kg body weight/day. Degeneration and necrosis of the pars recta was induced in seven of ten hamsters intraperitoneally given diphenylamine at 400 mg/kg body weight/day. Gross and microscopic renal lesions were not observed in any Mongolian gerbils. It was concluded that the Syrian hamster is more susceptible to the papillotoxic effects of diphenylamine than the Sprague-Dawley rat and the Mongolian gerbil. Renal papillary necrosis in the Syrian hamster treated orally with diphenylamine is reproducible, is of short onset, and is induced in a high proportion of the hamsters (70-90%).(ABSTRACT TRUNCATED AT 250 WORDS)     

The teeth of the horse: evolution and anatomo-morphological and radiographic study of their development in the foetus

The aim of this work was to study the ontogenetic process in teeth from their early appearance in the ossifying matrix of the mandible and maxilla, in different foetuses of scalar ages. Radiographic examinations of the skull and mandible hemisections were performed and the latero-medial (LM) and dorsoventral (DV) projections for the skull and mandible were analysed. A high-definition film-screen combination was used for this study. The exposure values ranged from 35 kV/6 mAs to 58 kV/10 mAs, according to the size of the skulls and their degree of ossification. The first dental germ observed was the P3, at 138-140 days of pregnancy. At 146 days, P2 and P4 dental germs were visible. At 160-168 days, the dental germ of the first deciduous incisor tooth (I1) appeared; at 180-188 days of pregnancy the germ of the second (I2), and at 224 days the germ of the third (I3), were detectable. At 275 days the dental germ of the mandibular first molar tooth (M1) appeared, while the maxillary M1, which was not visible radiographically, was represented by a jelly-like amorphous body within its alveolar cavity.     

Foetal Growth in the Reindeer

In connection with reindeer, slaughter 348 foetuses were collected at different foetal developmental stages and studied together with 20 full-term newborn calves with respect to weight, crown-rump length, metacarpal bone length and appearance of ossification foci. On the basis of these measurements polynomial growth curves were constructed. Weight gain was most rapid during the last trimester of gestation, but total and metacarpal bone length gain showed only minor acceleration towards the end of pregnancy. Ossification was apparent at an age of about 6 weeks. Undernutrition during late winter was observed to retard the foetal growth.     

Studies on the Appearance of the Centres of Ossification of the Axial Skeleton in the Feline Foetus

ossification of the vertebral column, ribs, sternum and skull of the foetuses of cats was studied radiographicaly. All individuals from 90 litters were radiographed both fresh and after impregnation with silver nitrate. Other were subjected to histologically examination and alizarin red straining. The ages of the litters were estimated using crown-rump length. Thje range of ages was from day 24 after mating to day 63. The times of observation of the first appearance of the centers of ossification were notedc using various techniques and both these times and all the centers for the axial skeleton appearing during foetal life were tabulated. A survey of the relevant literature is also given.     

The Ossification of the Pelvic Girdle and Leg Skeleton of the Quail (Coturnix coturnix japonica)

The onset of ossification centres of the pelvic girdle and leg skeleton of the quail in embryos and juvenile birds were studied. Specimens, which were cleared and were stained with Alcian Blue and Alizarin Red S, were examined at the stereomicroscope. The ilium and the pubis began to ossify at the 8th day (E8), whereas the ischium at E9. Perichondral ossification was observed at E6 in the femur, tibia and fibula. A secondary ossification centre was detected in the proximal epiphysis of the tibiotarsus at the 15th post‐hatching day (P15). The patella began to ossify at P30. Regarding the tarsal bones tibiale, pre‐tibiale and fibulare, ossification was observed at the E15, E12 and E16, respectively. The metatarsals II, III, IV ossified at E7, whereas the metatarsal I at E11. The centres of ossification of the 1st phalanges of all digits were observed at E9. At the same day, the ossification centres of the 2nd phalanx of digits II and III as well as the 3rd phalanx of digit III appeared. At E10, ossification was observed in the 2nd phalanx of digit I, in the 3rd phalanx of digit II and in the 2nd and 3rd phalanx of digit IV. In the 4th phalanx of digit III and in the terminal phalanges of digit IV, ossification was observed at E11. The data presented here provide useful baseline information on the normal sequential pattern of ossification in the pelvic girdle and leg skeleton in this species.     

Prediction of Parturition Time in Queens using Radiography and Ultrasonography

This study investigated the prediction of parturition in queens, as well as the effects of the queens' age and weight and the litter size on the accuracy of the prediction. A prospective study was performed in 24 purebred queens of 11 different breeds, all in normal body condition, using radiographic and ultrasonographic measurements of foetal femoral length (FL) and biparietal diameter (BPD) of f?tal skull that apply to different breeds. Pregnant queens with aborted or malformed foetuses were excluded. The examinations were performed up to three times during the second half of pregnancy; litter size was obtained with radiography, and FL and BPD measurements were taken of each foetus using both radiography and ultrasonography. The maximal FL and the transversal BPD were recorded for each foetus. Radiography showed the number of foetuses accurately but did not allow accurate prediction of time of parturition. However, ultrasonography did establish the best predictive model according to the data with the FL. This model corresponded to the formula Y = 37.864 ? 0.193 × FL + 1.227 × W ? 0.615 × LS ? 0.832 × A using the FL (10^?1 mm), litter size (LS, number of foetuses per queen) and maternal parameters (weight (W, kg) and age (A, years)). Time to parturition correlated positively with the queen's weight and negatively with her age (P < 0.01). The ultrasonographic FL associated with pregnancy and maternal factors appeared to be an accurate model to predict parturition .     

Susceptibility of Mongolian gerbils (Meriones unguiculatus) to leptospires and the protective effect of vaccination

Mongolian gerbils, Meriones unguiculatus, were shown to be highly susceptible to Leptospira interrogans serovars such as icterohaemorrhagiae, copenhageni, canicola, autumnalis, javanica, pyrogenes and hebdomadis as compared to guinea pigs and hamsters. Mortality with signs of haemorrhage and jaundice was recorded in all experimental rodents after intraperitoneal inoculation with all strains of the serovars indicated. However, Mongolian gerbils were comparatively susceptible to strains which were of low virulence to guinea pigs and hamsters. Use of leptospiral vaccination proved effective in protecting the animals against inoculum challenges. The Mongolian gerbil is a species that may be selectively and preferentially useful for assays on the protective effects of leptospiral vaccination.     

In vitro progesterone production of corpus luteum in pregnant Mongolian gerbils (Meriones unguiculatus)

The present study was conducted to determine the in vitro progesterone (P₄) production by Mongolian gerbil (Meriones unguiculatus) corpus luteum (CL) on days 9, 18 and 22 of pregnancy in comparison with rat CL on days 9 and 16. The culture medium of one CL per well of a 96‐well plate was changed after 4 h incubation and the CL were further cultured for 24 h. The P₄ in serum and in the medium were measured by enzyme immunoassay system. Gerbil CL weight measured after 24 h incubation was at the same level for all 3 days of pregnancy and significantly different from that of the rat CL for the 2 days of pregnancy. The serum P₄ level in gerbils was high in early pregnancy and decreased in advanced days of pregnancy. In contrast, the P₄ in rats was higher in the latter half of pregnancy. In vitro P₄ production by a single CL after 4 h incubation decreased significantly during the days of pregnancy in both the gerbil and the rat. P₄ values produced by the gerbil CL for 24 h incubation were significantly higher than after 4 h incubation in all 3 days of pregnancy, however, there was no difference between the two incubation time groups in the rat. In vitro P₄ production by CL correlated well with the serum P₄ level on the 3 days of pregnancy in the gerbil. In the rat, however, the relationship was inversed between the two parameters. The correlation in this experiment suggested that CL is the sole source of P₄ for the maintenance of the gerbil pregnancy, with the result of abortion after an ovariectomy on day 20 of pregnancy as described in our previous report.     

Morphogenesis of the cerebral fissures in sheep

The author studies the development and formation of the boundary fissures in the brains of the foetuses of sheep during their embryonal development from a vertex-to-coccyx length (VC length) of 38 mm (39th to 40th day) to birth. The marginal fissures of the cerebral hemispheres were found to develop first. The sulcus hippocami develops from them at a VC length of 46 to 48 mm (42nd to 45th day) and is one of the fissures with a constant course of formation. Sulcus rhinalis lateralis develops from a VC length of 70 to 72 mm (49th to 50th day). The caudal part of this fissure is deeper during the whole prenatal development than the rostral part.     

The ossification of the pectoral girdle and wing skeleton of the quail (Coturnix coturnix japonica)

The onset of ossification centres of the pectoral girdle and wing skeleton of the quail (Coturnix coturnix japonica) has been studied in embryos and juvenile birds, which were sampled daily from the 4th day of incubation up to the 12th day after hatching. Specimens, which were cleared and were stained with Alcian Blue and Alizarin Red S, were examined at the stereomicroscope. The furcula ossified with intramembranous ossification at the 7th day of incubation. The first centres of perichondral ossification in the scapula and the coracoid bones were observed at the 7th day of incubation. In the humerus, radius and ulna, perichondral ossification was observed at the 6th day of incubation. The carpal bones were ossified between the 8th and 10th day of the post-hatching period. The 2nd metacarpal bone began to ossify at the 6th day of the post-hatching period, whereas the 3rd and 4th metacarpal bones were ossified at the 7th day of incubation. At the 9th day of incubation, ossification was observed in the 1st phalanx of the alular digit and in the phalanges of the major digit. The 2nd phalanx of the alular digit began to ossify at the 12th, whereas the phalanx of the minor digit at the 14th day of incubation. The data presented here provide useful baseline information on the normal sequential pattern of ossification in the pectoral girdle and wing skeleton in this species.     

Ultrasonographic examinations of fetal growth of sheep between day 20 and day 50 of gestation

Previous studies on embryonic and fetal growth in sheep were mostly transversal using animals killed at various stages of gestation. Until now it was difficult to monitor the development of individual embryos/foetuses during pregnancy, especially during the first and second pregnancy month. Real-time ultrasound as a non invasive method could be an appropriate method for examination of embryonic and early foetal development in sheep. The aim of this study was to determine the embryonic and foetal development of the crown-rump-length (CRL) in pregnant ewes in relation to the number of fetuses and/or the breed. Between the 20th and 50th day of pregnancy the embryos/foetuses showed an exponential growth which can be best described by the equation of the form CRL (mm) = W * exp (k * day of pregnancy). The individual variability in embryofetal growth is in part due to the number of embryos per sheep and the sheep breed.     

Studies on reproduction in the goat. VII. Pregnancy and the development of the foetus and the foetal accessories of the goat

1. A total of 18 goats were ovariohysterectomized at different stages — 26 days to 145 days — of pregnancy.
2. The amniotic fluid increases from about 3.5 ml at 30 days to 600–1,000 ml per foetus at birth.
3. At birth the amount of allantoic fluid is approximately 600–1,100 ml and is to a small extent dependent on the number of foetuses.
4. The length of the foetus is about 1.4 cm at 30 days and 43 cm at 145 days, the lengthwise growth curve from the 30th day and onward being almost linear.
5. Hair follicles are visible around the 60th day and the eyes open between the 130th and 140th day.
6. The average length and weight of the goat kids at birth are 42.06 cm and 2.81 kg respectively.
7. The birth weight and length tend to increase with the increasing age of the dam.
8. The male does not appear to have any influence on the birth weight and length of the offspring.

     

Changes in blood levels of glucose and lactic acid in pregnant sows and fetuses and in sows and piglets 10 days after parturition

In three series of experiments the variations of lactic acid and glucose concentrations were investigated in pregnant sows, crossbreds of the Large White and Landrace breeds, and in their foetuses on the 104th and 113th day of pregnancy, then in farrowing sows of the same breed and their piglets at delivery (birth) and till the 10th day after birth. In nonpregnant sows the value of lactacidaemia is 1.60 +/- 0.08 mmol per 1. In the first twenty days of pregnancy it increases to 2.50 +/- 0.95 mmol per 1 (p less than 0.05). In the following days of pregnancy until the 81st to 100th day the value ranges from 1.5 to 1.7 mmol per 1. In the last twenty days of pregnancy it increases slightly to 2.10 +/- 0.25 mmol per 1. On the 104th and 113th day the values of lactacidaemia in foetuses in vena and arteria umbilicalis make 7.40 +/- 0.41 and 6.80 +/- 0.37, or 8.50 +/- 0.43 and 8.16 +/- 0.21 mmol per 1, respectively. Glucosaemia values are decreasing in pregnant sows in the first forty days, in the following period of pregnancy they are increasing and on the 101st to 120th day of pregnancy they make 5.39 +/- 0.26 mmol per 1. The foetus to dam ratio lactic acid concentrations is 2.3 and 2.1, respectively, on the 104th and 113th days. Lactacidaemia is highest in farrowing sows (3.15 +/- 0.19 mmol per 1), then there is a statistically significant decrease in the value of this characteristic, and on the day after delivery it makes 2.38 +/- 0.66 mmol per 1.(ABSTRACT TRUNCATED AT 250 WORDS)     

不同地域长爪沙鼠群体间遗传状况分析

应用27个生化基因位点,分别对首都医科大学实验动物科学部和浙江省实验动物中心饲育的2个长爪沙鼠群体进行了遗传分析。结果显示,首都医科大学实验动物科学部长爪沙鼠群体遗传适应性、遗传多样性水平、遗传变异程度都明显高于浙江省实验动物中心沙鼠群体（P〈0.05）,并且这2个沙鼠群体间未出现较为明显的遗传分化（FST〉0.05）。     

Cerebellar ataxia due to Toxocara infection in Mongolian gerbils,Meriones unguiculatus

We assessed the usefulness of gerbils as an experimental model for neurologic toxocarosis. Mongolian gerbils, Meriones unguiculatus, infected with Toxocara canis or Toxocara cati (1000 eggs/gerbil) showed progressive neurologic disorders from 50 days after infection in T. canis-infected gerbils or from 120 days after infection in T. cati-infected gerbils. The incidence of the onset was 6 of the 13 gerbils (49%) in the T. canis-gerbils and 5 of the 7 gerbils (71%) in the T. cati-gerbils. Histopathologically, the cerebellum was the most affected in both groups. We observed loss of Purkinje cells, glial nerve fibers, and nerve sheaths. We also found foci consisting of aggregated macrophages scattered in the white matter of the cerebellum. The affected gerbils showed ataxia and ultimately died of cachexia. Our findings suggest that irreversible neurologic toxocarosis in gerbils can be induced by infection with either T. canis or T. cati.     

人工巢箱条件下松鼠繁殖习性及仔兽生长发育研究

2008 ～ 2013年,在左家自然保护区对松鼠进行了野外观察和研究,结果如下：母鼠大约在产仔前两周左右开始筑巢,母鼠做巢时会根据当时的气候条件决定巢的类型;在哺乳期母鼠护子性极强,遇惊扰时会出现换巢的行为;仔兽出生到7日龄时体长为52.48 mm,尾长24.09 mm,体重13.96 g;42日龄时体长为149.48 mm,尾长136.07mm,体重达到140.77 g.数据分析表明,在仔兽生长发育过程中体重与体长、体重与尾长、体长与尾长均相关极显著.配制了体重生长的逻辑斯蒂方程：Wt=300.38/1＋ 37.325e-0.0831,该方程与实际生长数据拟合较好.     

Maintenance of pregnancy in ovariectomized Mongolian gerbils (Meriones unguiculatus)

Bilateral ovariectomy (Ovx) was carried out on day 20 of pregnancy in Mongolian gerbils ( Meriones unguiculatus ). The body weights of all groups tended to decrease on the day after the operation, and the decrease was significant in the group that was ovariectomized and given vehicle (Ovx + vehicle group). The body weight in this group never recovered until autopsy on day 24, which is normally 1 day before parturition. No fetuses survived to the time of autopsy in any of the animals of the Ovx + vehicle group. Daily administration of 4 mg of progesterone (P₄) prevented the termination of pregnancy in Ovx animals, but 1 mg did not. Treatment with estradiol 17β (E₂) in addition to 4 mg of P₄ tended to result in a lower rate of fetal survival than that of the Ovx group treated with 4 mg of P₄ alone. With regard to fetal weight, treatment with 4 mg of P₄ resulted in the same weight as in the sham-operated controls, but the addition of 0.2 or 1 μg of E₂ to the 4 mg of P₄ resulted in a significantly lower weight than that of fetuses in the 4 mg of P₄ group. The present study suggests that adequate maintenance of pregnancy in ovariectomized gerbils can be achieved by daily treatment with 4 mg of P₄ alone. Moreover, treatment with 0.2 or 1 μg of E₂ in addition to 4 mg of P₄ caused a deterioration in the maintenance of gestation, in contrast to the effects in rats, mice and hamsters.     

A Morphometric Study on the Skull of the German Shepherd Dog (Alsatian)

In this study, a total of 33 skulls of German shepherd (Alsatian) puppies between 45 and 105 days old were used. Animals were divided into two groups. Group 1 included puppies between 45 and 60 days old, and group 2 included those between 61 and 105 days old. In group 1, a skull weight of 36.95 g, a skull length of 113.96 mm, a maximum zygomatic width of 66.52 mm, a cranial length of 71.31 mm, a maximum neurocranium width of 52.11 mm, a viscerocranial length of 50.28 mm, a skull index of 58.43, a cranial index of 73.24, a facial index of 133.13 and a cranial volume of 55.38 ml were measured. In group 2, a skull weight of 61.17 g, a skull length of 143.38 mm, a maximum zygomatic width of 73.54 mm, a cranial length of 83.38 mm, a maximum neurocranium width of 53.70 mm, a viscerocranial length of 68.64 mm, a skull index of 51.44, a cranial index of 64.57, a facial index of 107.96 and a cranial volume of 75.75 ml were obtained. In order to determine the likely relationship, if any, between the indices and the other parameters, correlation coefficients were computed. It was found that all the measurements increased with age, while indices decreased, and an insignificant positive correlation was found between cranial volume and skull weight. The data obtained in this study may be of use in the consideration of the German shepherd type. For German shepherd dogs, which are a dolichocephalic race, it should be agreed that, in line with growth, the farther the values are from the mean value, the higher the defect rate of a puppy is. Also, the data may be of use in investigating the correlation between, for example, nasal cancer risk and the shape of the skull.     

瑞香狼毒根对长爪沙鼠的急性毒力测试

本文采用含17%瑞香狼毒(Stellera chamaejasme)根粉末的毒饵,依据孙氏改良寇氏综合计算法,实验室内测定了其对长爪沙鼠(Meriones unguiculatus)的急性毒力。根据预试验结果,采用最低剂量为7.0 g·kg^-1,最适剂量梯度比值K=0.65的5个剂量梯度的瑞香狼毒根毒饵饲喂长爪沙鼠。结果显示:试验组试鼠体重明显下降(P=0.029<0.05),完全致死组肝脏重/体重比对照组明显减小(P=0.014<0.05),但肾脏略增大(P=0.102>0.05)。其对长爪沙鼠的LD50为(20.37±0.086)g·kg^-1,95%平均可信限为(20.37±7.84)g·kg^-1,属弱毒水平。     

Absence of vertical transmission of Helicobacter pylori in an experimental murine model

Helicobacter pylori (H. pylori) infection is acquired mainly in early childhood but the precise transmission routes are unclear. This study examined the maternal H. pylori infection status in order to determine the potential of perinatal transmission. These issues were investigated using an experimental murine model, the Mongolian gerbil, which has been reported to be the most suitable laboratory animal model for studying H. pylori. Pregnant Mongolian gerbils, infected experimentally with H. pylori, were divided into two groups. The stomachs of the mother and litters were isolated and assessed for the transmission of H. pylori at the prenatal period (2 weeks after pregnancy) and at the parturition day. The bacterial culture, polymerase chain reaction (PCR) and rapid urease test were used to examine the presence of the transmitted H. pylori. There was no H. pylori observed in any of the fetuses during pregnancy and in the litters at parturition. This suggests that vertical infection during the prenatal period or delivery procedure is unlikely to be route of mother-to-child transmission of a H. pylori infection.