Electroacupuncture alleviates ciliary muscle cell apoptosis in lens-induced myopic guinea pigs through inhibiting the mitochondrial signaling pathway

AIM:To investigate the effect of electroacupuncture(EA)on the mitochondria-dependent apoptotic signaling pathway in the ciliary muscle of guinea pigs with negative lensinduced myopia(LIM).METHODS:Guinea pigs were randomly divided into normal control(NC)group,LIM group,LIM+SHAM acupoint(LIM+SHAM)group,and LIM+EA group.Animals in the NC group received no intervention,while those in other three groups were covered with-6.0 diopter(D)lenses on right eyes.Meanwhile,animals in the LIM+EA group received EA at Hegu(LI4)combined with Taiyang(EX-HN5)acupoints,while those in the LIM+SHAM group were treated at sham points.After treatments for 1,2,and 4wk,morphological changes in ciliary muscles were observed with hematoxylin and eosin(H&E)staining and nick end labeling(TUNEL),and the expression of the mitochondrial apoptotic signaling pathway-related molecules in ciliary muscles was measured by real-time quantitative polymerase chain reaction(qPCR)and Western blot.Additionally,the adenosine triphosphate(ATP)contents were also determined in ciliary muscles.RESULTS:Axial length increased significantly in the LIM and LIM+SHAM groups and decreased in the LIM+EA group.The ciliary muscle fibers were broken and destroyed in both LIM and LIM+SHAM groups,whereas those in the LIM+EA group improved significantly.TUNEL assay showed the number of apoptotic cells increased in the LIM and LIM+SHAM groups,whereas reduced in the LIM+EA group.ATP contents showed a significant decrease in the LIM and LIM+SHAM groups,whereas increased after EA treatment.Compared with the NC group,the dynamin-related protein 1(DRP1),Caspase3,and apoptotic protease activator 1(APAF1)levels were significantly increased in the LIM group and decreased in the LIM+EA group.CONCLUSION:The results provide evidence of EA inhibiting the development of myopia by regulating the mitochondrial apoptotic signaling pathway.

Feeding Management and Disease Prevention and Control of Pet Guinea Pigs

Guinea pig is widely used in clinical drug experiments as a laboratory animal.Because of its small and lovely size,guinea pig is often kept as a pet by many families.However,there are few reports on the feeding management and disease prevention and control of pet guinea pigs.This article introduced the experience and technology of feeding management and disease prevention of pet guinea pigs,in order to provide a reference for the feeding management and disease prevention of pet guinea pigs.

Effect of green flickering light on myopia development and expression of M1 muscarinic acetylcholine receptor in guinea pigs

AIM： To investigate the effects of green flickering light on refractive development and expression of muscarinic acetylcholine receptor（mAChR） M1 in the eyes of guinea pigs.METHODS： Thirty guinea pigs（15-20 days old） were randomly divided into three groups（n=10/group）. Animals in group I were raised in a completely closed carton with green flickering light illumination. Those in group II were kept in the open top closed carton under normal natural light. Guinea pigs were raised in a sight-widen cage under normal natural light in group III. The refractive status and axial length were measured before and after 8 weeks＇ illumination. Moreover, total RNA extracted from retinal, choroidal, and scleral tissues were determined by real-time reverse transcription polymerase chain reaction（RT-PCR）. The expressions of the receptor M1 were also explored in the retina, choroid, and sclera using immunohistochemistry.RESULTS： There was a remarkable reduction in refractive error and increase in axial length after 8-weeks＇ green flickering light stimulation（P〈0.001）. The expression of M1 receptor mRNA in sclera and retina in myopia group were remarkably lower than that in group II and III（P〈0.01）. Significant reduced expression of M1 receptor stimulated by green flickering light in retina and sclera tissues were also observed（P〈0.05）. However, there was no M1 receptor expression in choroid in 3 groups.CONCLUSION： Myopia can be induced by 8 weeks＇ green flickering light exposure in the animal model. M1 receptor may be involved causally or protectively in myopia development.

Guinea pigs as an animal model for sciatic nerve injury

The overwhelming use of rat models in nerve regeneration studies is likely to induce skewness in treatment outcomes.To address the problem,this study was conducted in 8 adult guinea pigs of either sex to investigate the suitability of guinea pig as an alternative model for nerve regeneration studies.A crush injury was inflicted to the sciatic nerve of the left limb,which led to significant decrease in the pain perception and neurorecovery up to the 4th weak.Lengthening of foot print and shortening of toe spread were observed in the paw after nerve injury.A 3.49 ± 0.35 fold increase in expression of neuropilin 1（NRP1） gene and 2.09 ± 0.51 fold increase in neuropilin 2（NRP2） gene were recorded 1 week after nerve injury as compared to the normal nerve.Ratios of gastrocnemius muscle weight and volume of the experimental limb to control limb showed more than 50% decrease on the 30 th day.Histopathologically,vacuolated appearance of the nerve was observed with presence of degenerated myelin debris in digestion chambers.Gastrocnemius muscle also showed degenerative changes.Scanning electron microscopy revealed loose and rough arrangement of connective tissue fibrils and presence of large spherical globules in crushed sciatic nerve.The findings suggest that guinea pigs could be used as an alternative animal model for nerve regeneration studies and might be preferred over rats due to their cooperative nature while recording different parameters.

Effects of gentamicin on choline acetyltransferase expression in paraolivary nucleus neurons of guinea pigs

BACKGROUND： It is generally accepted that gentamicin can damage the cochlear nerve and acoustic nerve. In recent years, scholars have focused on neuronal changes and neurochemical information in the brainstem primary auditory center. OBJECTIVE： To explore morphological changes of choline acetyltransferase （ChAT）-positive neurons in the paraolivary nucleus （PON） of guinea pigs, and the effect on hearing following gentamicin injection. DESIGN, TIME AND SETTING： Randomized grouping and morphological observational study was performed at Animal Experimental Center of General Hospital of Shenyang Military Area Command of Chinese PLA from January to August 2007. MATERIALS： A total of 48 healthy guinea pigs were randomly divided into model （n = 40） and control （n = 8） groups. The model group was divided into five subgroups at five time points of 1 and 3 days, 1, 2, and 3 weeks. METHODS： Guinea pigs in the model group were intraperitoneally injected with gentamicin, and those in the control group were intraperitoneally injected with the same volume of saline. MAIN OUTCOME MEASURES： Auditory brainstem-evoked potential was used to record auditory threshold; distribution and morphological changes of ChAT-positive neurons in the PON were observed with immunohistochemistry; section area and gray value of ChAT-positive neurons were measured with Quantimet 570 image-analyzing system. RESULTS： ChAT-positive neurons were diffusedly distributed in the PON. The majority was composed of large, round cells, with positive neurites that could be clearly observed. Following gentamicin injection, the positive neurons displayed an irregular outline, and their neurites began to shorten and disappear. The gray value increased with prolonged gentamicin administration （P 〈 0.05）. In addition, the somatic cross-sectional area was enlarged in the model group at 1 and 3 days after injection （P 〈 0.05）, whereas cell number significantly decreased at ;three weeks after injection （P 〈 0.05）. Starting at 3-4 days, behavioral features and auditory degrees became gradually aggravated with prolonged gentamicin administration （P 〈 0.05）. CONCLUSION： Gentamicin damaged ChAT-positive neurons in the PON, and long-term gentamicin treatment aggravated hearing impairment.

Safety Evaluation of a Potent Tetanus Vaccine (250 Lf) in Guinea Pigs (Cavia procellus)

A subacute toxicity study of a potent tetanus toxoid (250 Lf) was carried out in guinea pigs.The toxoid was injected subcutaneously at the nape of the neck at dose levels of 1.0, 1.5.and 2.0 ml in Groups Ⅱ. Ⅲ. and Ⅳ, respectively.In the controls (Group Ⅰ) 2.0 ml of aluminum phosphate suspension was given in each injection.Periodic evaluations of body weight, food/water intake, general observable behavior, hematology.and blood chemistry in toxoid-injected guinea pigs were similar to those in control guinea pigs.Thus, the toxoid did not cause any side effects up to four times the dose proposed for humans.1990 Academic Press, Inc.

Renal Toxicity of Nickel,Sodium Lauryl Sulphate and Their Combination after Dermal Application in Guinea Pigs

The guinea pigs were dermally exposed to nickel (Ni), sodium lauryl sulphate (SLS) and in their combination for 7 and 14 days. The exposure to Ni and SLS produced changes in enzymes and lipid peroxidation in kidney. The exposure to Ni or SLS depicted slight changes while combined exposure to Ni plus SLS exhibited more degenerative changes in kidney. The result of the study suggests that industrial workers and/or populations exposed simultaneously to Ni and SLS produces more damage to kidney.

Ingestion and In <i>Vivo</i>Digestibility of a Concentrated Granulated Feed Containing Seeds of <i>Moringa oleifera</i>Associated with <i>Pennisetum purpureum</i>in Guinea Pigs

In order to contribute to the improvement of guinea pig nutrition through the use of unconventional vegetable protein sources (Moringa oleifera seeds), experimental trials were carried out at the Animal Production and Nutrition Research Unit (URPRONAN) of the University of Dschang in April 2018. Moringa oleifera seeds from North Cameroon were divided into three treatments: the first consisted of whole Moringa oleifera seeds (MO-whole), the second of Moringa oleifera seeds soaked in cold water for 24 hours (MO-water) and the third of peeled Moringa oleifera seeds (MO-peeled). The seeds belonging to these three treatments were analyzed for the determination of the chemical composition before being incorporated into the different concentrates. Each concentrate was then granulated and combined with Pennisetum purpureum to make up the different rations. 40 English Guinea pigs with an average weight of 350 ± 50 g were used to evaluate the ingestion and digestibility of each ration. During the digestibility test which lasted 17 days (10 days of adaptation and 07 days of data collection), each ration was repeated on 10 Guinea pigs. The main results showed that the total tannin and phenol contents decreased significantly (p < 0.05) in M. oleifera seeds soaked for 24 hours (8.2% DM;2884 mg/100gMS) and pulped (13.6% DM;3156 mg/100gMS). The intake of crude cellulose (10.26 gMS/d) and crude protein (3.21 gMS/d) in rations containing whole M. oleifera seeds was significantly (p < 0.05) lower than in other rations. Similarly, crude protein digestibility (77.04%) of rations containing whole M. oleifera seeds was significantly (p < 0.05) lower than other rations. This study shows that Moringa oleifera seeds soaked for 24 hours or pulped can be used in guinea pig feed as an alternative source of protein.

Myopia induced by flickering light in guinea pigs: a detailed assessment on susceptibility of different frequencies

AIM: To investigate the effectiveness and feasibility of inducing myopia in guinea pigs by flickering light (FL) stimulation with different frequencies. METHODS: Seventy 2 -week-old guinea pigs were randomly assigned to six groups: five FL groups and a control group (n =12 for each). Animals in the five FL groups were raised under 500lx illumination with a duty diurnal cycle of 50% at a flash rate of 5, 1, 0.5, 0.25 and 0.1Hz respectively. Those in the control group were reared under steady 250lx illumination. Refraction, axial length, and radius of curvature were measured before and at 2, 4, 6, 8, 10 and 12 weeks after treatment. At week 12, the eyeballs were taken out and three ocular dimensions and dry weight of sclera were measured. RESULTS: A myopic shift and axial eye length increase developed in the five FL groups. Stimulation at 0.5Hz caused greater changes in myopic shift, axial elongation, eyeball dimension, and dry weight of sclera than stimulation at other frequencies. Compared with controls, eyes in 0.5Hz group were approximately -5.5 ±1.5D more myopic with increase in horizontal, vertical, axial dimensions by 0.89 ±0.3mm, 0.69 ±0.2mm, 1.12 ±0.2mm respectively and with increase in dry weight of sclera by 0.44mg. CONCLUSION: Chronic exposure to periodic illumination at temporal frequency is attended by development of excessive ocular enlargement and myopic refractive error. Emmetropization could bedisrupted differently by frequency alteration.

Dynamic changes of ocular biometric parameters:a modified form-deprivation myopia model of young guinea pigs

AIM: To evaluate the dynamic ocular biometric changes of a modified form-deprivation myopia model in young guinea pigs. METHODS: The animals were randomly assigned to two groups: the monocularly deprived facemask group (MDF, with all the right eyes covered, n=24) and the normal control group(free of facemask, n=24). Each group was then equally divided into four subgroups which were followed up for 2, 4, 6 and 8 weeks, respectively. Parameters measured from every eye included refraction, corneal curvature, axial length and the dry weight of sclera at the posterior pole. RESULTS: All the facemasks remained in place during the follow-up. The covered eyes developed myopia with the vitreous chamber lengthening and the dry weight of posterior sclera reduced at each time point compared with the contralateral uncovered (P<0.05 at all time points). The changes had a linear correlation with the deprivation time (P<0.05). There were no significant differences in all the parameters between the uncovered eyes of MDF group and the normal control group (P>0.05 at all time points). CONCLUSION: Monocular form deprivation with the facemask is highly effective and non-invasive in inducing axial myopia in guinea pigs. The axial myopia is mainly caused by the increased vitreous chamber length and the weakened posterior sclera rigidity. The form-deprivation eye didn't interfere with the natural development of the contralateral eye.

Electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure

Objective: To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure.Methods: Guinea pigs model of iron deficiency anemia complicated with chronic heart failure in 10 guinea pigs of the experimental group was made by feeding a low iron diet,pure water and subcutaneous injection of isoproterenol. The control group consisting of 11 guinea pigs was given normal food, normal water and injected with normal saline. The left ventricular outflow tract model specimen was also prepared. The standard microelectrode technique was used to observe electrophysiological changes of autonomic cells in the outflow tract of left ventricular heart failure complicated with iron deficiency anemia in guinea pig model. The indicators of observation were maximal diastolic potential, action potential amplitude, 0 phase maximal depolarization velocity, 4 phase automatic depolarization velocity, repolarization 50% and 90%, and spontaneous discharge frequency.Results: Compared with the control group, 4 phase automatic depolarization velocity,spontaneous discharge frequency and 0 phase maximal depolarization velocity decreased significantly(P < 0.01) and action potential amplitude reduced(P < 0.01) in model group. Moreover, repolarization 50% and 90% increased(P < 0.01).Conclusions: There are electrophysiological abnormalities of the left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with heart failure.

A Study on the Traditional Chinese Medicine Jinyebaidu for Prevention and Treatment of Intrauterine Infection with Guinea Pigs Cytomegalovirus

The purpose is to study the prophylactic and therapeutic effect of the traditional Chinese Medicine （TCM）-Jinyebaidu （JYBD） to guinea pig cytomegalovirus （GPCMV） intrauterine infection. The virus-free female and male guinea pigs were screened with nest-polymerase chain reaction （N-PCR）. After inbred, pregnant guinea pigs were selected and divided into 3 groups randomly： 5 guniea pigs of the blank control group were not given either GPCMV or JYBD. 31 guniea pigs of the positive control group were inoculated 1 mL （107 TCID50 ） suspension of GPCMV intraperitoneal. 10 gunlea pigs of the experimental group were inoculated GPCMV firstly and then perfused stomach with JYBD for 14 days （Dosage in accordance with the modulus of the weight ratio of human to guniea pig）. The effects of JYBD on the intrauterine infection of GPCMV were observed. The results showed that JYBD could decrease the maternal infection rate from 100 % （31/31） to 50 % （5/10） （P〈0. 001）, the intrauterine infection rate from 100% （72/72） to 75 % （21/28） （P〈 0. 001）, and the rate of abnormal outcome of pregnancy from 64.4 % （29/45） to 25.0 % （7/28） （P〈0. 001）, the infective symptoms being relieved. It can be concluded that traditional Chinese medicine- JYBD can prevent and treat GPCMV intrauterine infection, and can be expected a prophylactic drug for HCMV intrauterine infection.

Intraocular pressure with rebound tonometry and effects of topical intraocular pressure reducing medications in guinea pigs

AIM： To investigate the intraocular pressure（IOP） of adult guinea pig eyes with rebound tonometry（RBT）,and assess the effects of four distinctive topical IOP reducing medications including Carteolol,Brimonidine,Brinzolamide and Latanoprost.METHODS： The IOPs of twenty-four 12-week-old guinea pigs（48 eyes） were measured every two hours in one day with RBT as baselines.All the animals were then divided into four groups（Carteolol,Brimonidine,Brinzolamide and Latanaprost groups,n=6）.The IOPs were measured and compared to the baseline 1,2,3,5,7,9,15 and 24 h after treatment.RESULTS： The mean baseline IOP of 24 guinea pigs（48 eyes） was 10.3±0.36 mm Hg（6-13 mm Hg） and no binocular significant differences of IOPs were observed（t=1.76,P〉0.05）.No significant difference of IOP in Carteolol group at each time point was observed before and after treatment（t=1.48,P〉0.05）.In Brimonidine group,IOP was 2.2±1.9 mm Hg lower than the baseline after one hour（t=3.856,P=0.003） and lasted for one hour.In Brinzolamide group,IOP was 1.4±1.1 mm Hg lower than the baseline after one hour（t=4.53,P=0.001） and lasted for 7h and the IOP declined most at 3h.In Latanaprost group,IOP was 2.1±1.3 mm Hg lower than the baseline after one hour（t=6.11,P=0.001） and lasted for one hour.CONCLUSION： The IOP of guinea pig eyes is relatively stable compared to human eyes.In four reducing IOP medications,no significant effect of Carteolol is observed.Brinzolamide has the longest duration,while the Brimonidine has the shortest duration and the maximum level of treatment.

Antifertility effects of 60-day oral gavage of ethanol extract of Spondias mombin leaves in guinea pigs: A biochemical, reproductive and histological study

Objective:To investigate the impact of ethanol extract of Spondias(S.)mombin leaves on the biochemical parameters of testicular function,hormonal profile,sperm profile and reproductive outcomes of guinea pigs.Methods:Sexually matured male[(1000.40±8.12)g]and female[(810.00±7.09)g]guinea pigs were used.In testicular function study,a total of 24 male guinea pigs were randomised into 4 groups of 6 guinea pigs each.Group A(control)was orally administered 1 mL of physiological saline,once daily for 60 days while groups B,C and D were treated like the control group except that they were orally administered 100,250 and 500 mg/kg body weight of ethanol extract of S.mombin leaves.For the fertility study,the same animal groupings and treatments in the testicular function study were adopted.The male guinea pigs were paired with the females(1:1)and afterwards examined for pregnancy outcomes.Results:The ethanol extract of S.mombin leaves contained saponins,alkaloids,flavonoids,tannins,steroids,phenolics,phlobatannins,cardiac glycosides,cardenolides and dienolides with saponins(4.80 mg/mL)occurring the most whilst cardenolides and dienolides(0.08 mg/mL)were the least.The ethanol extract of S.mombin leaves significantly and dose dependently reduced the activities of alkaline phosphatase,glutamate dehydrogenase,3-hydroxy-3-methylglutaryl coenzyme A reductase,malic enzyme,17-β-hydroxysteroid dehydrogenase,lactate dehydrogenase,catalase and superoxide dismutase as well as levels of testosterone,glycogen,total protein and ascorbic acid in the testes when compared with the control group(P<0.05).All the doses of ethanol extract of S.mombin leaves also reduced the levels of sorbitol dehydrogenase,3-β-hydroxysteroid dehydrogenase,glucose-6-phosphate dehydrogenase and sialic acid whereas the levels of testicular acid phosphatase,gamma glutamyl transferase and cholesterol increased dose dependently(P<0.05).The serum luteinising hormone,testosterone and estradiol were reduced after the administration of ethanol extract of S.mombin leaves whereas levels of serum follicle stimulating hormone increased significantly.The 100 and 200 mg/kg body weight of ethanol extract of S.mombin leaves increased the testosterone/estradiol ratios whilst the 500 mg/kg body weight of ethanol extract of S.mombin leaves decreased it.The sperm motility,sperm count,normal sperm morphology,sperm density,sperm viability and semen viscosity were significantly reduced in the ethanol extract of S.mombin leaves-treated guinea pigs(P<0.05)whereas the head-,tail-and neck-defects increased significantly when compared with the control group(P<0.05).In contrast,the semen volume and pH were not significantly altered by the ethanol extract of S.mombin leaves(P>0.05).The ethanol extract of S.mombin leaves at both 100 and 250 mg/kg body weight significantly reduced the total number,circumference,weight and length of the pups whereas the 500 mg/kg body weight of ethanol extract of S.mombin leaves-treated rats did not produce any pup.The 250 and 500 mg/kg body weight of ethanol extract of S.mombin leaves induced degenerative and necrotic changes in the seminiferous tubules with vacuoles in the germinal epithelium and a few to complete absence of spermatozoa.In all of these,the 500 mg/kg body weight of ethanol extract of S.mombin leaves produced the most pronounced alteration on the parameters.Conclusions:S.mombin leaves have induced infertility in the male guinea pigs via endocrine dysregulation,anti-spermatogenic activity,testicular dysfunction and oxidative stress and made possible by the presence of saponins,alkaloids,flavonoids,tannins,steroids,phenolics,and cardiac glycosides.

In vitro Differentiation of Adipose-Derived Stem Cells into Hair Cell-Like Cells in Guinea Pigs

Objective Adipose-derived stem cells(ADSCs) are suggested to possess a highly plastic ability to differentiate into several specific cell types in addition to adipocyte lineages, including germ layer tissue-specific cell lineages such as chondrocyte, myocyte, neuronal, and osteoblast lineages. The aim of this study is to establish an in vitro culture technique for ADSCs in an adult guinea pig model that facilitate their differentiation into hair cell-like cells. Materials and Methods Cells from inguinal fat pads in adult guinea pigs were cultured with β-mercaptoethanol, RA, Forskorin, Heregulin, bFGF, BDNF and EGF. Cellular differentiation was examined using immunocytochemistry techniques. Results The ADSCs demonstrated hair cell immunophenotypes with expression of epitopes of the hair cell marker protein myosin Ⅶa. Conclusion ADSCs from adult guinea pig adipose tissue can differentiate into hair cell-like cells when cultured in vitro. ADSCs may serve as seed cells for tissue engineering.

Evaluation of an attenuated vaccine candidate based on the genotype C of bovine parainfluenza virus type 3 in albino guinea pigs

Bovine parainfluenza virus type 3（BPIV3） is considered as one of the most important respiratory tract pathogens of both young and adult cattle, and widespread among cattle in the world. BPIV3 was first reported in China in 2008 and four strains of BPIV3 were isolated from Shandong Province, known as genotype C（BPIV3c）. Pathogen investigations had shown that BPIV3 c infection was very common among cattle in China. To date, BPIV3 can be classified into genotypes A, B and C based on genetic and phylogenetic analysis. Serological survey also demonstrates that BPIV3 infection is widespread in China, however, there is still no available vaccine for BPIV3 prevention in China nowadays. In the present study, the BPIV3 c strain SD0835 was continuously passaged on Madin-Darby bovine kidney（MDBK） cells for hundreds of times, and the pathogenicity of passage 209 was reduced in guinea pigs. The passage 209 of BPIV3 c strain SD0835 was used as a live vaccine candidate to immunize the guinea pigs. The vaccination results revealed that two vaccinations could induce excellent serum neutralizing antibody responses as well as proliferation of T lymphocytes. The vaccinated guinea pigs were well protected against challenge with a low passage of BPIV3 c strain SD0835. Additionally, the percentages of CD4~＋ and CD8~＋ T cell subsets of animals in vaccinated group increased after immunization; T cell subsets on day 2 after challenge in both groups decreased, and the decline of CD4~＋ and CD8~＋ T cell subsets levels of four guinea pigs in vaccinated group was relatively moderate, comparing with that of the control group. These data support further testing of the attenuated virus as an effective candidate vaccine.

Establishment and Effects of Ginger and Kikyoto of a Haloperidol-Induced Dysphagia Model in Guinea Pigs

Dysphagia induces aspiration and causes aspiration pneumonia. There is no treatment for dysphagia fundamentally. Haloperidol reportedly induces dysphagia. In the present study, we established a haloperidol-induced dysphagia model in guinea pigs, and evaluated the effects of ginger, kikyoto, and a mixture of ginger and kikyoto on swallowing. Swallowing ability was evaluated using behavioral tests, computed tomography (CT), and videofluoroscopic examination of swallowing. To investigate the effect of ginger and kikyoto on swallowing, ginger, kikyoto, or a mixture of ginger and kikyoto was administered orally to guinea pigs with haloperidol-induced dysphagia. Effects of these compounds were evaluated with behavioral tests. Chronic administration of haloperidol reduced the number of swallows, as evaluated by the behavioral test and videofluoroscopic examination of swallowing. In our model, these compounds improved swallowing dysfunction. Our results suggest that this model might be useful in revealing the pathogenesis of dysphagia and evaluating compounds that might improve swallowing.

Digital measuring the ocular morphological parameters of guinea pig eye in vivo with Python

AIM:To quantitatively measure ocular morphological parameters of guinea pig with Python technology.METHODS:Thirty-six eyeballs of eighteen 3-weekold guinea pigs were measured with keratometer and photographed to obtain the horizontal,coronal,and sagittal planes respectively.The corresponding photo pixels-actual length ratio was acquired by a proportional scale.The edge coordinates were identified artificially by ginput function.Circle and conic curve fitting were applied to fit the contour of the eyeball in the sagittal,coronal and horizontal view.The curvature,curvature radius,eccentricity,tilt angle,corneal diameter,and binocular separation angle were calculated according to the geometric principles.Next,the eyeballs were removed,canny edge detection was applied to identify the contour of eyeball in vitro.The results were compared between in vivo and in vitro.RESULTS:Regarding the corneal curvature and curvature radius on the horizontal and sagittal planes,no significant differences were observed among results in vivo,in vitro,and the keratometer.The horizontal and vertical binocular separation angles were 130.6°±6.39°and 129.8°±9.58°respectively.For the corneal curvature radius and eccentricity in vivo,significant differences were observed between horizontal and vertical planes.CONCLUSION:The Graphical interface window of Python makes up the deficiency of edge detection,which requires too much definition in Matlab.There are significant differences between guinea pig and human beings,such as exotropic eye position,oblique oval eyeball,and obvious discrepancy of binoculus.This study helps evaluate objectively the ocular morphological parameters of small experimental animals in emmetropization research.

Changes of nitric oxide synthase and cyclic guanosine mono-phosphate in form deprivation myopia in guinea pigs

Background The form deprivation （FD） reduces spatial contrasts and induces myopia. Nitric oxide and cyclic guanosine monophosphate （cGMP） are involved in visual signal transmission. This study investigated changes in nitric oxide synthase （NOS） activity and cGMP concentration in ocular tissues in acute and chronic form deprivation myopia. Methods Guinea pigs had one eye covered by translucent glass for 7, 14 or 21 days. Untreated litter mates were used as controls. NOS activity and cGMP concentrations in the retinal, choroidal and scleral tissues of FD eyes and control eyes were analyzed by radioimmunoassay after various durations of FD. The expression of NOS subtypes was identified by immunohistochemistry. Results Myopia was successfully induced in FD eyes after 14 days. Compared with control groups, the retinal NOS activity and cGMP concentrations in the FD eyes significantly increased after 14 and 21 days while the retinal NOS activity in the FD eyes was transiently suppressed by 7 days of FD. The NOS activity and cGMP concentrations of choroid and sclera in the FD eyes were higher than in the control groups at 21 days. The three isoenzymes of nitric oxide synthase were detected in the ocular tissues of guinea pigs. Conclusions The NOS activity and cGMP concentrations were upregulated after chronic FD and the retinal NOS activity was transiently suppressed at acute FD. The function of elevated NOS activity may be mediated by cGMP.