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1.
BackgroundAppendiceal goblet cell carcinoids (GCCs) exhibit neuroendocrine and adenocarcinoma features.ResultsMedian age for f/m was 59/58 years, respectively, and similar for localized and disseminated disease. At diagnosis 54 patients had localized appendiceal disease (f/m: 29/25). According to TNM 24% had Stage I, 70% had Stage II and 6% had Stage III. Twenty-nine patients had disseminated disease (f/m: 27/2). Chromogranin A, synaptophysin and p53 were positive in >90%. Serotonin was positive in 70%. Median Ki67 index was 32% (6-75%) and higher in Tang group C (50%) compared to group A (30%; p<0.0001), and group B (30%; p<0.004). All patients had surgery. Sixty-three (76%) had radical resections including all patients with localized disease. Median OS was 83 months. The 1-, 5- and 10-year survival rates were 90%, 58%, and 38%, respectively. For localized disease OS was 164 months and 1-, 5- and 10-year survival rates were 100%, 80%, and 55%, respectively. For disseminated disease OS was 19 months and 1-, 5- and 10-year survival rates were 73%, 18% and 6%, respectively. The 1-, 5- and 10 year-survival rates for f/m were 87%/96%, 49%/76% and 31%/57%, respectively (p = 0.02). According to the Tang classification group A, B, and C OS was 118, 83 and 20 months, respectively (p = 0.0002).ConclusionThe Tang classification was found to be a significant prognostic factor, while the Ki67 index was not. Localized GCCs occurred equally in males and females, while disseminated GCCs were mostly seen in females. Median age of patients with localized disease and disseminated disease was identical. Cox regression analysis found Stage IV, focally positive synaptophysin and non-radical surgery as strongest negative prognostic factors.  相似文献   

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3.
Plasma testosterone levels were estimated in different male goat age groups. In Black Bengal at 15–30 days, 2–3 months, 3–5 months and in Black Bengal, Beetal, Beetal × Black Bengal and Black Bengal × Beetal at 6 months and > 12 months (n = 6 in each case). The plasma testosterone levels (mean ± s.e.m.) were high (7.1 ± 2.0 ng/ml) at 2–3 months and fell drastically to 2.6 ± 0.5 ng/ml before attaining sexually mature levels of 4.6 ± 0.9 ng/ml at 6 months and 4.1 ± 0.8 ng/ml at > 12 months. The mature bucks of all genetic groups had a plasma testosterone concentration of 4.6 ± 0.8 ng/ml. Genetic group differences were not significant.  相似文献   

4.
Ten, bull calves of the Norwegian Red breed were hemicastrated at the age of 1 1 2 -3 months . Ten, normal bull calves of similar age served as controls. No significant differences were found in plasma testosterone levels or in weight between the two groups during the ensuing seven-month test period. Eight, male pigs were hemicastrated at 1-2 months of age. Eight, normal male pigs served as controls. Plasma testosterone, androstenone, and body weight were measured fortnightly in all pigs until the age of 6-7 months. Androstenone in adipose tissue was measured from 4-5 months of age. No significant differences were found between normal and hemicastrated animals in any monthly interval. However, when combining the measurement at 5-6 and 6-7 months of age for plasma testosterone and 5alpha-androstenone and 5alpha-androstenone in fat, the normal pigs had significantly higher values than the hemicastrates (p<0.05). The weight of the single testis from the hemicastrated pigs at slaughter nearly equalled the combined weight of both testes from the controls. Thus, hemicastration did not appear to have any significant effect on the level of testicular steroids in plasma in bulls or growth rate in bulls and boars, but did have a slight effect on testicular steroids in plasma in pigs at 5-7 months of age.  相似文献   

5.
In this study, we measured the ghrelin, leptin, and insulin variations in lean and obese Zucker fa/fa rats during the acute phase of body weight gain. At 2 months of age, plasma insulin and leptin concentrations in fa/fa rats were, respectively, 470% and 3700% higher than in lean rats (p <0.0001). Plasma ghrelin was significantly lower (-24.6%; p <0.02) than in lean rats. At 6 months of age, ghrelin increased in both genotypes but the difference was no more significant. The inverse correlations existing between ghrelin and either body weight (BW), insulin or leptin at 2 months of age were no more observable in 6-month-old rats. At 6 months of age, the lean rats had the same body weight as the 2-month-old obese rats. In these body weight-matched rats, ghrelin was not correlated with BW but it remained negatively correlated with insulin and leptin. At the same body weight, obese rats had a much lower plasma ghrelin than lean rats (717+/-42 vs. 1754+/-83 pg/ml; p <0.0001). These data indicate that body composition rather than body weight is the primary factor for the down-regulation of the ghrelin system. This down-regulation constitutes a mechanism of defense of the organism against the development of obesity at least during the first part of life.  相似文献   

6.
The kidney growth in children is not linear. The aim of this study was to define normal dimensions of kidneys in healthy infants during the first six months of life. A prospective ultrasonographic screening of 1870 kidneys in 935 healthy full-termed infants (476 males, 459 females) was done throughout a 5-year period. Measured kidneys were divided into six age groups according to gender and side. In the first three months of life males had both kidneys longer than same-age females (p < 0.05). In the next three-month-period the difference between sexes was not significant (p > 0.05). Left kidneys were longer than right kidneys in both sexes in the first six months of life (p < 0.01). Four nomograms with normal values of kidney lengths, according to age, sex and side were done in newborns and infants in the first 6-months of life.  相似文献   

7.
The purpose of the study was to determine the effects of a 6-month supervised, job-specific moderate exercise program in police officers on body composition, cardiovascular and muscular fitness. Body weight (BW), body mass index (BMI), and cardiovascular and muscular fitness were assessed at baseline, after a 6-month supervised fitness program and at 12-month follow-up (18 months). One hundred sixty-five (n = 131 men and n = 34 women) young (mean ± SEM, 26.4 ± 1.9 years), overweight (BMI = 26.2 ± 1.2 kg·m) police officers participated. Aerobic exercise progressed from 3 d·wk, 20 minutes per session at 60% of the heart rate reserve (HRR) to 5 d·wk, 30 minutes per session at 75% of HRR at 3 months, and this level was maintained until 6 months. Muscular strength training progressed using 8 different calisthenics exercises from 3 d·wk, 2 sets of 5 repetitions using the participant's own BW to 5 d·wk, 3 sets of 15 repetitions of the participant's own BW at 3 months, and this level was maintained until 6 months. Cardiovascular and muscular fitness was measured using a 0.25-mile obstacle course incorporating various job-specific exercises and expressed as the physical abilities test (PAT) time. There was a significant reduction in BMI (-0.6 ± 0.2 kg·m, p < 0.001) and BW (-2.8 ± 2.3 kg) and reduction in PAT time (-11.9 ± 2.1%, p < 0.01) from baseline to 6 months. However, BMI (1.4 ± 1.1 kg·m, p < 0.001), BW (5.1 ± 3.0 kg, p < 0.01), and PAT time significantly increased (12.8 ± 2.2%, p < 0.01) from 6 to 18 months. There were no sex by time differences. The practical applications of this study indicate that a supervised, job-specific exercise program for police officers improves fitness and body composition after 6 months in both men and women, but continued supervision of exercise program may be necessary for maintenance of health benefits.  相似文献   

8.
The chemical composition and metabolism of low-density lipoproteins (LDLs) in a population of Benedictine nuns were studied after 5-month periods during which the predominant dietary fats were sunflower oil, fluid of palm, peanut oil, milk fats, low erucic acid rapeseed (LEAR) oil, corn oil, olive oil, soybean oil. The population was divided into three groups. The control group (C) included 12 subjects selected at random by taking 2 subjects per age pool among those with plasma cholesterol less than 230 mg/dl. Groups H1 and H2 were selected in the same way among those with plasma cholesterol less than 230 mg/dl. Groups H1 and H2 comprised 6 subjects and differed from each other in the amount of plasma cholesteryl esters, i.e., below and above the mean value of group C. Changes in LDL composition, according to the dietary fat, were associated with changes in LDL catabolism studied in fibroblast cultures, but no significant differences were found between the three groups.  相似文献   

9.
BackgroundAccurate diagnosis and classification of von Willebrand disease (VWD) are essential for optimal management. The von Willebrand factor multimers analysis (VWF:MM) is an integral part of the diagnostic process in the phenotypic classification, especially in discrepant cases. The aim of this study was to evaluate the performance of a new Hydragel 11VWF multimer assay (H11VW).MethodsAnalytical performance characteristics such as repeatability (intra-assay variability, in gel between track variation), reproducibility (inter-assay variability, between gel variation), sensitivity, EQA performance and differences between two commercially available VWF:MM kits (H5VW and H11VW) were analysed in healthy volunteers'' plasmas using in-house prepared reference plasma.ResultsRepeatability and reproducibility results of H11VW demonstrated acceptable and equivalent performance with previously verified H5VW. Participation in EQA was successful. No statistically significant difference was detected between H5VW and H11VW kits for different fractions of multimers: LMWM p=0.807; IMWM p=0.183; HMWM p=0.774.ConclusionsH11VW demonstrated acceptable analytical performance characteristics. H11VW kit conveniently offers a more significant number of samples on a single gel. H5VW and H11VW kits can be used in daily practice interchangeably.  相似文献   

10.
Helicobacter pylori is thought to be related to atherosclerosis and aneurysm development. We aimed to detect virulance factors of H. pylori and examine the potential etiopathogenetic relationship between aortic aneurysm and H. pylori, 58 abdominal aortic aneurysm (AAA) and 38 ascending aortic aneurysm (AsAA) cases and 57 Healty control group (HCG) were included. We investigated H. pylori IgG by ELISA and virulance factors by Western-Blot (WB) method. No difference was found between AAA (67.24%), AsAA (73.68%) and HCG (57.89%) for H. pylori IgG (p > 0.05). A significant difference was found between AsAA (78.95%) and HCG (57.89%) for H.pylori IgG (p < 0.05) by ELISA and a significant difference was found only between AsAA (100%) and HCG (37.5%) for H. pylori IgG in the 45-55 age group by WB. A statistically significant difference was found between AAA and AsAA for VacA and CagA + VacA and CagA + VacA + UreA antigens and also a significant difference was found between AsAA and HCG for CagA + UreA antigens (p < 0.05). Finally, we suggest that H. pylori VacA has a more important role than CagA in the development of two aneurysms especially in ruptured AAA. New extended studies detecting H. pylori DNA are needed to detect the aetiopathogenesis between aneurysm types and H. pylori.  相似文献   

11.
The aim of this study was to determine the location of antipsychotic-induced weight gain in drug na?ve, first episode patients with schizophrenia. Various fatness and fat distribution parameters (by Computerized Tomography scanning and anthropometry) and 1600 hr plasma cortisol were measured in 19 (15 men and 4 women) subjects with schizophrenia (mean age = 31.0 years; mean body mass index [BMI] = 24.6 kg/m2) and an equal number of age- and sex- matched controls (mean age = 32.6 yr; mean BMI = 23.0 kg/m2). Patients were then given either olanzapine or risperidone. Sixteen patients were re-tested following a treatment period lasting approximately 6 months. Patients with schizophrenia, had significantly more intra-abdominal fat [IAF] (116.8 +/- 20.2 cm2 vs. 38.0 +/- 4.8 cm2, respectively; t = 3.80, df = 18, p < 0.0001) and had higher levels of plasma cortisol (360.2 +/- 49.6 nmol/L vs. 192.7 +/- 19.7 nmol/L, respectively; t = 3.13, df = 18, p < 0.003) than appropriately matched control subjects. Treatment with atypical antipsychotics did not result in a significant increase in IAF (116.8 +/- 20.2 cm2 vs. 131.7 +/- 20.9 cm2; p = NS) though visceral fat stores still remained significantly higher than those seen in controls (38.0 +/- 4.8 cm2) (F = 9.34; df = 2, 51; p < 0.0003). However, plasma levels of cortisol did significantly decrease (360.2 +/- 49.6 nmol/L +/- vs. 316.2 +/- 48.4 nmol/L; p < 0.05). Pre-treatment levels of IAF did not differ between those who received risperidone and those who were given olanzapine (123.0 +/- 35.9 cm2 vs. 113.1 +/- 15.7 cm2, respectively; t = 0.20, df = 16, p < 0.84). The increase in IAF did not differ between those given risperidone and those who received olanzapine (26.9 +/- 12.1 cm2 vs. 18.24 +/- 11.44 cm2, respectively; t = 0.50, df = 16, p < 0.63). Patients with drug na?ve, first episode, schizophrenia have higher levels of visceral fats stores as compared to matched control subjects. Treatment with atypical antipsychotics does not result in a significant increase in IAF distribution.  相似文献   

12.
The development of obesity, hyperinsulinemia and six hepatic lipogenic enzymes in Avy/a mice were compared to that in a/a mice. Correlation between body weight, liver weight, plasma insulin concentration and activities of hepatic enzymes was analyzed. In the Avy/a mice, body weight, liver weight and plasma insulin level increased steadily as the mice aged. In the a/a mice, the change of these three parameters was much slower. Plasma insulin concentration in a/a mice did not increase until eight months of age. Compared with a/a mice, Avy/a mice had higher 6-phosphogluconate dehydrogenase and fatty acid synthetase activities at two months of age; lower citrate cleavage enzyme, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase activities at three months of age; lower citrate cleavage enzyme and glucose-6-phosphate dehydrogenase and higher acetyl CoA carboxylase activities at five months of age; and higher malic enzyme, citrate cleavage enzyme and 6-phosphogluconate dehydrogenase activities at eight months of age. There were significant correlations between plasma insulin level and body weight and between plasma insulin level and the activities of malic enzyme and citrate cleavage enzyme in Avy/a mice. The correlation between body weight and malic enzyme and citrate cleavage enzyme activities disappeared after the analysis was adjusted for plasma insulin level.  相似文献   

13.

Background

Mutations in the P53 gene are among the most common genetic abnormalities in human lung cancer. Codon 273 in the sequence-specific DNA binding domain is one of the most frequently mutated sites.

Methodology

To investigate the role of mutant p53 in lung tumorigenesis, a lung specific p53(273H) transgenic mouse model was developed. Rates of lung cancer formation in the transgenic animals and their littermates were evaluated by necropsy studies performed in progressive age cohorts ranging from 4 to 24 months. In order to establish the influence of other common genetic abnormalities in lung tumor formation in the animals, K-Ras gene mutation and p16INK4a (p16) promoter methylation were evaluated in a total of 281 transgenic mice and 189 non-transgenic littermates.

Principal Findings

At the age extremes of 4–12 and 22–24 months no differences were observed, with very low prevalence of tumors in animals younger than 12 months, and a relatively high prevalence at age 22 months or older. However, the transgenic mice had a significant higher lung tumor rate than their non-transgenic counterparts during the age of 13–21 months, suggesting an age-related shift in lung tumor formation induced by the lung-specific expression of the human mutant p53. Histopathology suggested a more aggressive nature for the transgenic tumors. Older mice (>13 months) had a significantly higher rate of p16 promoter methylation (17% v 82%). In addition, an age related effect was observed for K-Ras codons 12 or 13 mutations, but not for codon 61 mutations.

Conclusions/Significance

These results would suggest that the mutant p53(273H) contributes to an acceleration in the development of spontaneous lung tumors in these mice. Combination with other genetic and epigenetic alterations occurring after the age of 13 months is intimately linked to its oncogenic potential.  相似文献   

14.
Our study examined whether repeated preventive oral administration of live probiotic bacterial strains Escherichia coli O83:K24:H31 (Ec O83), Escherichia coli Nissle 1917 O6:K5:H1 (Ec Nis) and Lactobacillus casei DN 114001 (Lc) can protect mice against dextran sodium sulfate (DSS)-induced colitis. A significant decrease in average symptom score was observed in Ec O83-, Ec Nis- and Lc-pretreated group (p < 0.05). Significant differences in body mass loss between Lc pretreated mice with DSS-induced colitis were found when compared with nontreated mice (p < 0.05). PBS pretreated mice had a significantly shorter colon than Ec O83-, Ec Nis- and Lc-pretreated mice (p < 0.05). Administration of Lc significantly decreased the severity of DSS induced histological marks of inflammation (p < 0.05). A significant difference (p < 0.05) was also found in specific IgA level against given probiotic in enteral fluid between colitic mice and healthy mice pretreated with Ec 083 and Ec Nis.  相似文献   

15.
The n.m.r. spectrum of abscisic acid (ABA) formed from [1,2-13C2]acetate by the fungus Cercospora rosicola shows 13C-13C coupling between C-6' (41.7 p.p.m.; 36 Hz) and the downfield 6'-methyl group (6'-Me) (24.3 p.p.m, 36 Hz). This 6'-Me, therefore, is derived from C-3' of mevalonate [Bennett, Norman & Maier (1981) Phytochemistry 20, 2343-2344]. An i.n.e.p.t. (insensitive nuclei enhanced by polarization transfer) pulse sequence demonstrated that the downfield 13C signal is produced by the 6'-Me that gives rise to the upfield 1H 6'-Me signal (23.1 d). The absolute configuration of this, the equatorial 6'-Me group, was determined as 6'-pro-R by decoupling and n.O.e. (nuclear-Overhauser-enhancement) experiments at 300 MHz using ABA, ABA in which the axial 6'-pro-S 5'-hydrogen atom had been exchanged with 2H in NaO2H and the 1',4'-cis- and 1',4'-trans-diols formed from these samples. The configuration at C-1' and at C-6' are now compatible with a chair-folded intermediate during cyclization, as proposed for beta- and epsilon-rings of carotenoids. ABA in solution exists, as in the crystalline form, with the ring in a pseudo-chair conformation. The side chain is axial and the C-3 Me and the C-5 hydrogen atoms are predominantly cis(Z).  相似文献   

16.
BACKGROUND: In Prader-Willi syndrome (PWS) obesity and partial growth hormone (GH) deficiency are frequently observed. The risks of cardiovascular diseases and early death are increased. We examined inflammatory markers in adult PWS, before and during 12 months of GH treatment. METHOD: Twelve PWS adults, median age 23.5 years (17-37) and median BMI 33.8 kg/m2 (21.2-50.4), participated. Serum interleukin-6, tumour necrosis factor alpha, high sensitive protein C-reactive protein (HCRP), cholesterol, triglycerides, leptin, adiponectin, glucose, insulin, insulin-like growth factor I and body composition were measured at baseline and after 6 and 12 months of GH treatment. RESULTS: Median and range at baseline for interleukin-6 was 9.87 ng/l (1.76-10.72), for tumour necrosis factor alpha 2.39 ng/l (1.00-3.26) and for HCRP 7.64 mg/l (0.41-41.1) (normal values < 5 ng/l, < 8 ng/l and<5 mg/l, respectively). At baseline correlations between inflammatory markers and age, anthropometry, body composition and the metabolic parameters were non-significant; only positive associations were found between tumour necrosis factor alpha and body weight (r = 0.617, p = 0.033) and between HCRP and BMI (r = 0.594, p = 0.041). GH treatment non-significantly decreased the levels of the inflammatory markers. CONCLUSION: In this pilot study, levels of interleukin-6 and HCRP were increased, and GH intervention did not significantly reduce the levels. Chronic inflammation might contribute to the increased cardiovascular morbidity and mortality in PWS.  相似文献   

17.
In children with various forms of cardiac diseases (aged 2 months to 16 years) significantly higher plasma atrial natriuretic peptide (ANP; range 36-680, median 247 pg/ml) and cyclic 3'5'-guanosine monophosphate (cGMP; range 0.2-46, median 8.2 pmol/ml) levels were found than in control children (p less than 0.0001). In control children (aged 4 months to 17 years) plasma ANP and cGMP levels were measured in the range of 2.4-98 pg/ml and of 0.2-2.8 pmol/ml, respectively. There was a linear correlation between the two parameters in children with cardiac diseases (r = 0.62, p less than 0.01). Children with elevated mean right atrial pressure (i.e., greater than 6 mm Hg) showed significantly higher plasma ANP levels than children with normal atrial pressure (p less than 0.01). However, there was only a weak linear correlation between mean right atrial pressure and plasma ANP levels (r = 0.48, p less than 0.01). Plasma ANP levels from right atrium, pulmonary artery, left atrium and left ventricle were significantly higher than those from vena cava (p less than 0.05). Analysis of ANP-like immunoreactive material by high performance liquid chromatography suggested that alpha-ANP is the major form of circulating ANP in blood of children with cardiac diseases.  相似文献   

18.
In an attempt to elucidate the role of calcium in the life of the edible Achatinid snail, Limicolaria flammea (Miller) I investigated short and long term effects of calcium added to the food. The short term experiments lasted for 18, 30 and 32 weeks respectively, while the long term experiment to determine life time utilization of calcium carbonate lasted for 15 months. In the short term experiments, hatchlings were divided into densities of one, ten and 50 snails. In the 10 snail group, there was a positive correlation between calcium provision, body weight (t test, p < 0.01; r = 0.96, p < 0.0001) and shell length (t test, p < 0.01; r = 0.96, p < 0.00001). There was also a positive correlation between increase in shell length and availability of calcium in the 1 snail group (t test, p< 0.01; r = 0.99, p < 0.00001). In the 50-snail group, the correlation was positive for shell length of the snails (t test, p < 0.05; r = 0.99, p < 0.0001) and body weight (t-test, p < 0.05; r = 99, p < 0.00001). Mortality was very high in the snails deprived of calcium and they did not produce eggs. In the long term experiment, there were three feeding peaks in L. flammea. In the first feeding peak, amount of food and calcium ingested by the snails increased in the first three months of life. The second feeding peak occurred at six months of age, while the last occurred at 10 months of age. The amount of calcium ingested during the second peak decreased gradually in the 4th and 5th month. The amount of calcium ingested was lowest during the 3rd feeding peak. The period of highest weight gained by the snails was between the 1st and 6th month and then dropped at between six and 12 months of age which corresponds to the period of egg production. There were also three peaks of egg production; the first was between six and eight months (535 eggs), the second at between 10 and 11 months (350 eggs) and the third at 13 to 14 months (310 eggs) respectively.  相似文献   

19.
In this study, the authors investigated the physiologic effects of the altered body composition that results from surgical removal of large amounts of subcutaneous adipose tissue. Fourteen women with body mass indexes of greater than > 27 kg/m2 underwent measurements of fasting plasma insulin, triglycerides, cholesterol, body composition by dual-energy x-ray absorptiometry (DXA), resting energy expenditure, and blood pressure before and after undergoing large-volume ultrasound-assisted liposuction.There were no significant intraoperative complications. Body weight had decreased by 5.1 kg (p < 0.0001) by 6 weeks after liposuction, with an additional 1.3-kg weight loss (p < 0.05) observed between 6 weeks and 4 months after surgery, for a total weight loss of 6.5 kg (p < 0.00006). Body mass index decreased from (mean +/- SEM) 28.8 +/- 2.3 to 26.8 +/- 1.5 kg/m2 (p < 0.0001). This change in body weight was primarily the result of decreases in body fat mass: as assessed by DXA, lean body mass did not change (43.8 +/- 3.1 kg to 43.4 +/- 3.6 kg, p = 0.80), whereas DXA total body fat mass decreased from 35.7 +/- 6.3 to 30.1 +/- 6.5 kg (p < 0.0001). There were significant decreases in fasting plasma insulin levels (14.9 +/- 6.5 mIU/ml before liposuction versus 7.2 +/- 3.2 mIU/ml 4 months after liposuction, p < 0.007), and systolic blood pressure (132.1 +/- 7.2 versus 120.5 +/- 7.8 mmHg, p < 0.0002). Total cholesterol, high-density lipoprotein cholesterol, plasma triglycerides, and resting energy expenditure values were not significantly altered after liposuction.In conclusion, over a 4-month period, large-volume liposuction decreased weight, body fat mass, systolic blood pressure, and fasting insulin levels without detrimental effects on lean body mass, bone mass, resting energy expenditure, or lipid profiles. Should these improvements be maintained over time, liposuction may prove to be a valuable tool for reducing the comorbid conditions associated with obesity.  相似文献   

20.
Tanyang is one of the most important sheep breeds in the northwest of China. However, there is no detailed data on sexual development and timing of puberty/sexual maturity of this breed. This experiment was designed to study the relationships between growth rate and sexual development by measuring body weight, testis diameter, and plasma testosterone concentrations, and observing sexual behavior through puberty from 3 to 8 months old of entire Tanyang ram lambs. At same time, to assess the potential efficacy and welfare benefits of non-surgical castration, the effect of active immunization against gonadotrophin-releasing hormone (GnRH) on sexual development and growth rate on ram lambs was evaluated, and compared with surgically castrated and entire lambs. The results showed that body weight increased at a constant rate from 3 to 8 months old of age. Testis diameter increased rapidly between 3 and 5 months, followed by a period of slow growth. Plasma testosterone concentrations increased sharply from 3 to 6 months of age (P<0.05), after which there were no significant changes from 6 to 8 months of age. Sexual behavior started from 5 months of age. After ram lambs were immunized against GnRH at 3 months of age, there was no increase in testis diameter in the first 4 months after immunization. Plasma testosterone concentrations remained at similar levels to surgically castrated lambs until 6 months of age, and the onset of sexual behavior was delayed, compared with entire ram lambs. GnRH immunization and surgical castration had no significant effect on the body weight by the end of this experiment. These results suggest that 4-5 months of age is a critical period for pubertal changes and testosterone plays an important role in the initiation of puberty and sexual maturity of Tanyang ram lambs in China. In addition, a single shot GnRH immunization at 3 months, acting as an alternative to surgical castration, is a practical method for Chinese Tanyang ram lambs, and provides animal welfare benefits.  相似文献   

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