支配鸡输卵管蛋白分泌部的感觉神经元定位：CB—HRP法逆行追踪

采用霍乱毒素－辣根过氧化物酶标记法，逆行追踪鸡输卵管蛋白分泌部初级感觉神经元位置。结果显示，两侧颈静脉神经节，结状神经节以及颈１２至腰茬１２脊神经节出现标记细胞，左侧的标记细胞明显多于右侧。在脊神经节的分布区域内，有两个相对集中区，分别位于胸５至腰茬２和腰荐８至腰荐１０。     

母鸡输卵管子宫部初级感觉神经元的CB-HRP法定位研究

应用CB-HRP溶液注入母鸡输卵管子宫部浆膜下，四甲基联苯胺（TMB）组织化学呈色，以探察母鸡输卵管子宫部初级感觉神经元的定位。结果表明：母鸡输卵管子宫部的初级感觉神经元位于双侧T1-LS13脊神经节、颈静脉神经节和结状神经节。标记细胞数分布不均，在体左侧多于体右侧，在脊神经节多于颈静脉神经节和结状神经节。在脊神经节内标记细胞有T5-LS1和LS8-LS11前后两个相对集中区，峰值分别在T7和LS11。说明尽管母鸡输卵管子宫部是单侧发育成熟脏器，但其感觉沿双侧脊神经和迷走神经传人中枢，以体左侧传入为主；且感觉经脊神经传入较迷走神经传入中枢优势明显。     

鸡胸腺副交感传入神经元的定位及其初级传入纤维在中枢内的投射—CB—HRP...

将ＣＢ－ＨＲＰ注入鸡一侧胸腺内，通过逆行和跨神经节追踪鸡胸腺副交感传入神经元的定位及其初级传入纤维在中枢的投射，其结果如下：①在双侧迷走神经结状节内出现标记细胞，标记细胞以大型细胞为主，呈长椭圆形和梭形的双极神经元，亦发现少量假单极神经元，还发现两个多极神经元。②双侧颈静脉神经节和岩神经节内出现标记细胞，标记细胞以小型细胞为主，突起不明显。③在闩前、闩后双侧孤束核内发现传入纤维的标记终末，在闩后０     

兔减压神经的纤维成分—HRP法

艇ＨＲＰ法对兔减压神经进行了研究，标记的传入神经元绝大多数位于迷走神经结状节尾侧半部偏一侧，少数见于颈静脉神经节，其中枢突标记终末见于延髓闩以上的孤束核内侧部，腹侧部以及迷背核内。在颈前节也出现标记细胞，表明减压神经中也含有起源于 前节的交感节后纤维成分。主动脉压力感受器有经减压神经来的感觉神经交感节后神经纤维支配。提示减压神经是含有一般内脏传入和一般内脏传出纤维的混合神经，为研究心血管生理提供了     

用辣根过氧化物酶标记法对鸡盲肠传入神经元分布的研究

用辣根过氧化物酶逆行法研究鸡盲肠感觉神经元的定位。结果表明，被标记的支配盲肠的初级传入神经元位于Ｔ２－ＬＳ１和ＬＳ８－ＬＳ１２脊神经节，峰值位于Ｔ５，Ｔ６，ＬＳ９和ＬＳ１０脊神经节；在颈静脉神经节，结状神经节和脊髓内未见到标记细胞。     

兔颈前神经节感觉纤维终末的起源--HRP法研究

以３０％ＨＲＰ注入５只家兔颈前神经节,在Ｃ１－Ｔ２脊神经节、迷走神经结状节、颈静脉神经节、舌咽神经近节和远节以及三叉神经节均出现标记细胞,以舌咽神经远节最多,占４２．５５％;Ｃ１－Ｔ２脊神经节次之,占３４．１９％;其余各神经节标记细胞均在１０％以下。标记细胞均以中小型细胞为主。５例均未见膝神经节。结果表明,投射至颈前神经节的感觉纤维来源广泛,为“以交感神经节为中心的中枢外短反射环路”理论和针灸机理     

家兔大结肠及三焦俞穴区传入神经元的节段性分布——HRP、CT-HRP法研究

选用健康家兔31只,分组用HRP和CT—HRP法研究了家兔大结肠及三焦俞穴区传入神经元的节段性分布。结果:大结肠传入神经元胞体弥散性分布于双侧T_2～Co_1脊神经节和左、右迷走神经结状节内,脊神经节的标记细胞主要集中于T_(12)～L_4,高峰节段为L_1和L_2,L_7～S_1段为少标记或无标记细胞区;从标记细胞的数量看,大结肠的神经传入途径以伴随交感神经传入为主,随副交感神经传入的纤维以迷走神经传入途径为主;脊神经节内的标记细胞多为圆形或椭圆形,以中、小型细胞为主,大型细胞较少。迷走神经结状节内的标记细胞均为中、小型细胞,以小型细胞为多;三焦俞穴区传入神经元胞体位于T_8～L_4脊神经节内,多集中于T_11～L_3,其传入纤维投射到T_11～L_3,段脊髓的第Ⅰ～Ⅳ层,以Ⅱ、Ⅲ层最为密集;大结肠与三焦俞穴区传入神经元胞体在T_8～L_4脊神经节内重合,其主峰值范围基本一致。     

马盲肠感觉神经元的节段性分布——HRP法研究

用HRP法对5匹马盲肠感觉神经元的节段性分布规律进行了研究。结果:标记细胞出现在T_2～L_4脊神经节内。其中T_(8～15)脊神经节内数量最多,其次是T_(3、7)和T_(16、17),其余脊神经节内的标记细胞数量较少。盲肠的感觉神经元,以小细胞为主,中细胞次之,大细胞最少。感觉神经均传入双侧脊神经节中,标记细胞的数量右侧明显地多于左侧(二者之比约4:1)。     

支配家兔下颌淋巴结的神经来源

本实验用ＨＲＰ逆行追踪法对家兔下颌淋巴结的神经来源进行了研究。结果表明；在同侧三叉神经半月状神经节和Ｃ１－４脊神经出现标记神经原，以三叉神经经半月状神经的标记细胞最多，提示下颌淋巴结的初级感觉主要经三叉神经传入；在同侧的颈前节，星状神经节及Ｔ２－３椎旁节出现标记的交感后神经原，主要出现于颈前节的吻侧端。     

肾俞穴,后三里穴与子宫相关的神经基础

应用辣根过氧化物酶（ＨＲＰ）法和荧光素双标记法，研究了家兔子宫与肾俞穴、后三里穴的外周神经联系。结果显示，支配子宫与肾俞穴、后三里穴的初级传入神经元及交感节后神经元分布节段部分重叠，在腰１（Ｌ１）脊神经节有少量的荧光素双标记细胞，约占该节荧光素标记细胞总数的２．６％，表明Ｌ１脊神经节有一些初级传入神经元，其周围突分支分布于肾俞穴和子宫，提示子宫与肾俞穴除通过中枢途径联系外，还可通过外周突分支投射的感觉神经元直接相联系；在胸１２～荐３（Ｔ１２～Ｓ３）交感神经节出现大量分别支配子宫和后三里穴的标记细胞，这两种细胞紧密相邻，提示支配子宫和后三里穴的交感节后神经元之间，可能还存在直接或间接联系。上述结果为穴位－内脏相关机理提供了形态学证据。     

辣根过氧化物酶标记法研究鸡直肠传入神经元的分布

采用辣根过氧化物酶（HRP）逆行追踪法研究了鸡直肠感觉传入神经元的分布，证明鸡直肠脊神经感觉传入神经元集中分布于双侧T5～LS3和LS7～LSl2脊神经节，峰值位于T7和LS10脊神经节；LS7-LS12区段脊神经节内标记细胞明显多于T5～LS3区段脊神经节内的标记细胞；标记细胞为椭圆形和圆形。     

Comparison of three methods for arthrodesis of the distal intertarsal and tarsometatarsal joints in horses

OBJECTIVE: To evaluate the effects of diode laser surgery (LS), surgical drilling (SD), and intraarticular sodium monoiodoacetate (MIA) as methods for fusing the distal intertarsal (DIT) and tarsometatarsal (TMT) joints in horses. STUDY DESIGN: Experimental study. ANIMALS: Adult horses (15) without radiographic signs of osteoarthritis (OA) of the DIT and TMT joints. METHODS: Group 1 (n=3) had LS performed bilaterally on DIT and TMT joints; 1 horse was evaluated for 1 week and 2 horses were evaluated for 2 weeks. Group 2 (n=6) had LS on DIT and TMT joints of 1 tarsus and MIA administration into the contralateral DIT and TMT joints and were evaluated for 6 months. Group 3 (n=6) had LS performed on DIT and TMT joints of 1 tarsus and SD of the contralateral DIT and TMT joints and were evaluated for 12 months. Postoperative comfort, lameness, radiography, microradiography, and histology scores were compared using repeated measures ANOVA, and paired or 2 sample t-tests; significance was set at P<.05. RESULTS: LS caused the least postoperative morbidity. In group 2, horses were less lame in 4 LS-treated limbs and 2 MIA-treated limbs at 6 months when compared with the contralateral limb. In group 3, horses were less lame in 5 LS-treated limbs and 1 SD-treated limb at 6 and 12 months compared with the contralateral limb. On microradiography, 11 MIA joints and 2 LS joints had bone bridging the joint at 6 months whereas 8 SD joints and 5 LS joints had bone bridging at 12 months. Significantly more joint space was bridged by bone in MIA- (51.4%) and SD (46.2%)-treated joints compared with LS joints at 6 (30.6%) and 12 (28.5%) months, respectively (P<.05). CLINICAL RELEVANCE: SD and MIA resulted in more bone bridging of the distal 2 tarsal joints, than LS. However, LS seemingly caused less pain and discomfort to horses in the immediate postoperative period; horses were generally less lame in the LS limb. More laser energy may need to be applied to these joints to promote fusion; however, it may also have beneficial effects beyond fusion. Further research on horses with OA of the distal 2 tarsal joints is needed to determine whether LS can cause soundness without facilitating bony fusion.     

The effect of litter size before weaning on subsequent body development, feed intake, and reproductive performance of young rabbit does

An experiment was performed to study the effect of litter size before weaning on subsequent body development and composition, feed intake, and reproductive performance of young rabbit does with the objective to improve reproductive performance. Litter size (LS) before weaning (treatment) was 6, 9, or 12 kits. After weaning (30 d), 58 female kits per treatment (in two successive replicates) were reared and fed for ad libitum intake to 14.5 wk of age (end of rearing). At 14.5 wk of age, receptive does were inseminated. Nonreceptive and nonpregnant does were inseminated at 17.5 wk of age. The experiment ended when the second litter was weaned. Part of the animals was slaughtered to determine body composition at the end of the experiment (replicate one) and at the end of rearing (replicate two). At weaning, BW differed among treatments (P < 0.05; 855, 773, and 664 +/- 15 g for LS6, 9, and 12, respectively). Compensatory growth was observed. At the end of rearing, LS12 does were smaller (P < 0.05) than LS9 and LS6 does (3,524, 3,778, and 3,850 +/- 48 g, respectively). After first lactation, no difference in BW among treatments was found. Compared with LS6, empty body weight (BW minus gut, bladder, and uterus content) of LS12 contained more (P < 0.05) nitrogen (32.5 vs 31.1 +/- 0.3 g/kg), more (P < 0.05) ash (30.7 vs 28.3 +/- 0.6 g/kg), and less (P < 0.05) fat (168.6 vs 200.2 +/- 8.6 g/kg). No differences in body composition among treatments were found at the end of the experiment. During rearing, LS12 had the lowest (P < 0.05) daily feed intake (152, 164, and 169 +/- 2 g/d for LS12, 9, and 6, respectively). During the reproductive period, no differences in feed intake among treatments were found. Kindling rate (the number of kindlings per number of inseminations) was not influenced by treatment. In the first parity, total litter size (number of alive and stillborn kits) was lower (P < 0.10) for LS12 than for LS9 (6.4 vs 8.6 +/- 0.5, respectively). When first mating was delayed by 3 wk, an increased (P < 0.05) total litter size was found regardless of treatment (7.5 and 9.4 +/- 0.3 for 14.5, and 17.5 wk, respectively). Decreasing litter size before weaning from nine to six kits did not alter future reproductive performance. Based on results of this study, it seems advisable to perform a limited standardization level (at nine kits) after kindling and postpone first mating to an older age (17.5 wk) to improve reproductive performance.     

Divergent selection for uterine capacity in rabbits. II. Correlated response in litter size and its components estimated with a cryopreserved control population

Our objective was to evaluate the correlated responses to selection for litter size and its components after 10 generations of divergent selection for uterine capacity (UC). A total of 294 intact females from the 11th and 12th generations of divergent selection for high and low UC and from a cryopreserved control population was used (139, 112, and 43 females, respectively). Uterine capacity was assessed as litter size in unilaterally ovariectomized females. Traits recorded on females for up to five parities were litter size (LS) and number born alive (NBA). Laparoscopy was performed in all females at d 12 of their second parity, and the ovulation rate (OR) and number of implanted embryos (IE) were recorded in these females. Embryo survival (ES = IE/OR), fetal survival (FS = LS/IE), and prenatal survival (PS = LS/OR) were computed. Correlated responses in LS and in its components were inferred using Bayesian methods. Correlated responses in LS were asymmetric. The divergence between high and low lines was 2.35 kits, mainly because of a higher correlated response in the low line (1.88 kits). The lower LS in the low line was associated with a lower PS (control - low = 0.14), because of decreases in ES and FS.     

Alternative methods of selection for litter size in mice: II. Response to thirteen generations of selection

Selection was conducted on an index of components of litter size (I = 1.21 x ovulation rate + 9.05 x ova success; ovulation rate measured by number of corpora lutea and ova success measured as number of pups born + number of corpora lutea), on uterine capacity (measured as number of pups born to unilaterally ovariectomized dams) and on litter size concurrent with an unselected control for 13 generations. Selection criteria (IX = index, UT = uterine capacity, LS = litter size and LC = control) were applied in each of three replicates. In an evaluation after five generations, IX and LS each exceeded LC by about .5 pups, with no response in UT. After 13 generations, mean ovulation rate, ova success and litter size (measured as number of fetuses at 17 d gestation in intact females) were, for IX, 14.25, .84, 11.95; for LS, 14.15, .82, 11.64; for UT, 12.61, .86, 10.77; and for LC, 12.27, .82, 9.98. The regression of number born (litter size in IX, LS and LC; uterine capacity with only a functional left uterine horn in UT) on cumulative selection differential across 13 generations was .12 +/- .01, .09 +/- .02 and .08 +/- .02 for IX, LS and UT, respectively. The regression of breeding value for litter size on each selection criterion, estimated as response in the generation-13 evaluation divided by cumulative selection differential, was .11 +/- .02, .08 +/- .01 and .05 +/- .03 for IX, LS and UT, respectively. Regression of response in number born on generation number was .17 +/- .01, .15 +/- .04 and .10 +/- .02 for IX, LS and UT, respectively. Selection in IX was promising relative to LS, and selection in UT changed number born.     

Selection for ovulation rate in rabbits

An experiment of selection for ovulation rate was carried out. Animals were derived from a synthetic line first selected 12 generations for litter size, then 10 generations for uterine capacity. Selection was relaxed for 6 generations. Selection was based on the phenotypic value of ovulation rate with a selection pressure on does of 30%. Males were selected from litters of does with the highest ovulation rate. Males were selected within sire families in order to reduce inbreeding. Ovulation rate was measured in the second gestation by a laparoscopy, 12 days after mating. Each generation had about 80 females and 20 males. Results of three generations of selection were analyzed using Bayesian methods. Marginal posterior distributions of all unknowns were estimated by Gibbs sampling. Heritabilities of ovulation rate (OR), number of implanted embryos (IE), litter size (LS), embryo survival (ES), fetal survival (FS), and prenatal survival (PS) were 0.44, 0.32, 0.11, 0.26, 0.35, and 0.14, respectively. Genetic correlation between OR and LS was 0.56, indicating that selection for ovulation rate can augment litter size. Response to selection for OR was 1.80 ova. Correlated responses in IE and LS were 1.44 and 0.49, respectively. Selection for ovulation rate may be an alternative to improve litter size.     

High dietary calcium to phosphorus ratio and alkali-forming potential as factors promoting silica urolithiasis in sheep

Sheep were used to study factors previously found to promote silica urolithiasis in a rat model. In addition to high silica, these dietary factors included elevated calcium, a high calcium to phosphorus ratio and alkali-forming effects. Wether lambs had ad libitum access to a diet of 50% of grass hay and 50% ground oats plus supplement. Diet analysis was 3.4% total SiO2, .29% calcium, .25% phosphorus, 11.3% CP and 28% ADF. Treatments (40 lambs/treatment) consisted of a control (C), limestone to increase dietary calcium to .6% (L), L + 1% sodium bicarbonate (LS) and L + 1% ammonium chloride (LA). After a 91-d experimental period followed by a 56-d postexperimental finishing period, silica kidney deposits were found in all treatments, and SiO2 made up 74% to 97% of the urolithic ash. Kidney urolith incidences in the four treatments were C, 7/40; L, 12/40; LS, 20/40; and LA, 9/40. A higher urolith incidence in LS (LS vs C, P less than .05) and a trend toward a higher incidence in L (L vs C, P less than .2), accompanied by elevated urine pH (L = LS greater than C greater than LA, P less than .01), lend support to the concept that high-silica diets having high calcium to phosphorus ratios and alkali-forming potentials contribute to silica urolithiasis.     

Beef cattle feed intake and growth: empirical Bayes derivation of the Kalman filter applied to a nonlinear dynamic model

Feed intake and growth rate of a single group of growing-finishing feedlot beef cattle are difficult to predict. Subsequent performance can be projected more precisely from past performance of a group of cattle. Using an adaptation of the statistical procedure called the empirical Bayes (EB) derivation of the Kalman filter, estimates from any dynamic model (M) can be adjusted based on past performance. The model may be either linear or nonlinear. With this procedure, predictions of intake and body weight gain are periodically updated by multiplying the estimates from M by statistically weighted factors. These factors are derived from the ratio of performance in each period to the performance predicted by M. For comparison to the EB adjustment, weighting of factors by least-squares (LS) adjustment also was tested to predict subsequent feed intake and gain. The test data base consisted of periodic feed intake and gain observations (usually 28 d) for 200 pens of feedlot steers. Bias of prediction was lower for EB than for M or LS for feed intake and (usually) gain. Intake and gain prediction errors averaged for the whole feeding period were .42 kg/d for intake and .14 kg/d for gain by EB, being .84 and .18 kg/d more precise than M and .12 and .33 kg/d more precise than LS predictions. More than two observations were needed before LS produced accurate prediction but after about 80 d, LS and EB estimates converged. Accuracy of both estimates continued to improve as days on feed increased.(ABSTRACT TRUNCATED AT 250 WORDS)     

Selection for ovulation rate in rabbits: genetic parameters and correlated responses on survival rates

The aim of this work was to evaluate the correlated responses on survival rates after 10 generations of selection for ovulation rate (OR). Selection was based on the phenotypic value of ovulation rate estimated at d 12 of second gestation by laparoscopy. Traits recorded were litter size (LS), estimated as total number of rabbits born per litter in up to 5 parities; OR, estimated as the number of corpora lutea in both ovaries; the number of implanted embryos (IE), estimated as the number of implantation sites; the number of right and left IE (RIE and LIE); ovulatory difference (OD), defined as the difference between the right and the left OR, expressed as an absolute value; implantatory difference (ID), defined as the difference between RIE and LIE, expressed as an absolute value; embryonic survival (ES), calculated as IE/OR; fetal survival (FS), calculated as LS/IE; prenatal survival (PS), calculated as LS/OR. A total of 1,081 records were used to analyze ES, and 770 were used to analyze FS and PS. The number of records used to analyze the other traits ranged from 1,079 for ID to 3,031 for LS. Data were analyzed using Bayesian methodology. Genetic parameters of OR, OD, and LS were estimated in a previous paper. Estimated heritabilities of IE, ID, ES, FS, and PS were 0.11, 0.03, 0.09, 0.24, and 0.14, respectively. Estimated repeatabilities of IE, ID, and ES were 0.22, 0.12, and 0.20. Estimated phenotypic correlations of OR with ES, FS, and PS were -0.07, -0.26, and -0.28, respectively. Their estimated genetic correlations with FS and PS were negative (probability of being negative 1.00 and 0.98, respectively). Nothing can be said about the sign of the genetic correlation between OR and ES. Ovulation rate was phenotypically uncorrelated with ID. Their estimated genetic correlation was positive (probability of being positive 0.91). The genetic correlation of ID with PS and LS was not accurately estimated. Phenotypic and genetic correlations between LS and survival rates were positive (probability of being positive 1.00). In 10 generations of selection, FS decreased around 1% per generation. No correlated response in ES was observed. In summary, the decrease in FS in rabbits selected for OR seemed to be responsible for the lack of correlated response observed in LS.