Low Dose and Standard Dose of Imatinib Therapy for Patients with Chronic Myeloid Leukemia in Akita Prefecture, Japan.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 4575-4575
Author(s):  
Naoto Takahashi ◽  
Yoshihiro Kameoka ◽  
Hirofumi Saitoh ◽  
Naohito Fujishima ◽  
Makoto Hirokawa ◽  
...  
Keyword(s):  
Side Effects ◽  
Clinical Characteristics ◽  
Low Dose ◽  
Standard Dose ◽  
Point Mutations ◽  
Imatinib Therapy ◽  
Group I ◽  
Akita Prefecture ◽  
Group 2 ◽  
Group 1

Abstract The IRIS study for CML patients demonstrated the excellent clinical and cytogenetic/molecular effects of imatinib. Patients participating in the IRIS trial were selected according to strict eligibility criteria. The clinical features of patients are usually much more heterogeneous in practical situations than in clinical trials. Sometimes, patients cannot be treated with the standard dose of imatinib because of severe toxicity, especially older patients or patients who had already been treated with the other drugs. In this study, we analyzed whether patients could still be effectively treated using lower doses. Our study analyzed 86 CML patients from 17 hospitals in Akita prefecture. 80 patients were in CP, one patient was in AP, 4 patients were in BC, and one patient had cytogenetic relapse after allo-SCT. All patients were treated with imatinib between December 2001 and July 2007. Initially a dose of 400mg/day was given to almost all patients. Later the dose was decreased in a subset of patients experiencing imatinib-induced side effects. We classified patients into two groups according to the imatinib dosage and analyzed their clinical characteristics [Table 1] and the accumulation of CCR/MMR [Figure 1, 2]. In Group 1, we analyzed 55 patients received 300mg or more of imantiib per day. In Group 2, we analyzed 31 patients received less than 300mg of imatinib per day. Patients in Group 2 were older and had more histories of pretreatment and showed a higher frequency of adverse effects of imatinib than in Group 1. There were no significant differences of CCR/MMR rate between Group 1 and Group 2. This study reproduces the imatinib efficacy results described in the IRIS study, not only for patients treated with standard dose imatinib and for patients who could not take 400mg/day because of imatinib toxicity or other complications. We did not observe an increase in frequency of BCR-ABL point mutations in patients receiving a lower dose of imatinib, suggesting that the low dose imatinib treatment analyzed in our study does not enhance imatinib resistance by increasing BCR-ABL point mutations. In conclusion, we provide data supporting the use of lower doses of imatinib for CML patients that cannot be given sufficient dosage of imatinib for reasons such as severe hematological or non-hematological side effects or other complication. Clinical Characteristics of Patients in Group I and II Group 1(n=55) Group 2(n=31) P Average doseage 380 mg/day 185 mg/day Average age (% of over 70 yrs) 57.7 yrs (22 %) 68.0 yrs (58 %) .001 (.007) History of treatment with IFN/HU before imatinib therapy 16% 55%. 002 Adverse effect (Grade3/4) 16% 42% .009 PFS to AP/BC at 60 Mo 97.8% 89.6% .28 CCR /MMR rate 78% / 51% 61% / 39% .09 / .27 Point mutation of bcr-abl in patients without MMR 4/17 2/13 .99 Figure Figure Figure Figure

Analysis of the Incidence and Characteristics of Venoocclusive Disease (VOD) of the Liver in Pediatric Hematopoietic Progenitor Cell Transplant (HPCT) Patients with Heparin Alone Vs. Heparin and Ursodiol Prophylaxis at the Medical College of Wisconsin.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 4306-4306
Author(s):  
Julie-An Talano ◽  
Jessica Brown ◽  
Jennifer McArthur ◽  
Mollie Mulberry ◽  
Daniel Eastwood ◽  
...  
Keyword(s):  
Medical Records ◽  
Low Dose ◽  
Pediatric Patients ◽  
Hematologic Malignancy ◽  
Post Transplant ◽  
Dose Heparin ◽  
Group I ◽  
Group 2 ◽  
Low Dose Heparin ◽  
Group 1

Abstract Abstract 4306 VOD is a serious and potentially life-threatening complication of HPCT as a result of liver injury from the effect of chemotherapy and/or radiation. The reported incidence rate in pediatric HPCT patients varies widely from 5% to 40%. Previous studies have shown the beneficial effects of post-transplant pharmacological therapies such as ursodeoxyholic acid (ursodiol), heparin, and defibrotide at preventing VOD. However, the combined effect of heparin and ursodiol prophylaxis in preventing VOD in pediatric patients has yet to be determined. This study evaluated retrospectively whether there was a benefit of such combined therapy in pediatric HPCT patients. Our center adopted as standard practice for all HPCT patients the initiation of low dose heparin at 4 units/kg/hour with the commencement of conditioning for HPCT until day +28 post transplant. In 2003, we combined ursodiol 10 mg/kg TID to start with HPCT conditioning and to continue until day + 100 post transplant with low dose heparin through day + 28 for all pediatric HPCT patients. We performed a retrospective chart review and compared the characteristics and the incidence of VOD in patients who underwent transplantation from 1996-2002 and received heparin alone compared to 2003-2008 when the patients received the combination of heparin and ursodiol prophylaxis. Patients were identified through medical records with the ICD diagnosis of VOD. The medical records were reviewed and those patients who did not meet the Baltimore criteria for the diagnosis of VOD were excluded. Only patients who developed VOD with their first transplants were included. Group I = Heparin (216) Group II = Heparin + Ursodiol (220) Allogeneic 187 (86.5%) 160 (72.7%) Autologous 29 (13.5%) 60 (27.3%) Median Age 9 yrs 8 yrs Male 123 (57%) 135 (62%) Female 93 (43%) 85 (38%) Non-malignant 34 (15.7%) 50 (22.8%) Hematologic malignancy 143 (66.2%) 109 (49.5%) Non-hematologic malignancy 39 (18.1%) 61 (27.7%) # VOD 13 5 The 100 day incidence of VOD was 0.0605 (SE 0.01618) in group 1 and 0.0227 (SE 0.01002) in group 2. The difference is 0.0377 (SE 0.0190) and based on a standard normal distribution with a p = 0.0473. The estimated risk of VOD for patients receiving Heparin + Ursodiol is 0.94 (risk or hazard ratio) that of the risk with Heparin alone, with a 95% confidence interval of (0.918, 0.960). This represents about a 6% reduction in risk for those receiving Heparin + Ursodiol. The day 100 survival in the VOD patients was 6 out of 13 in group 1 and 3 out of 5 in group 2. In conclusion, low dose heparin and ursodiol prophylaxis appears to be an effective strategy in VOD prevention in pediatric patients. The combination appeared to be more effective than heparin alone. However, this study is limited in that it is retrospective in nature. Disclosures: Off Label Use: heparin and ursodiol as VOD prophylaxis.

scholarly journals Therapeutic efficacy of low dose (Dhaka regimen) versus high dose (Pritchard regimen) magnesium sulphate for management of eclampsia and impending eclampsia

2018 ◽  
Vol 7 (6) ◽  
pp. 2333
Author(s):  
Nisha Bhagat ◽  
Preet Kamal Bedi ◽  
Davinder Pal ◽  
Arunima Saini
Keyword(s):  
Side Effects ◽  
Magnesium Sulphate ◽  
Lower Incidence ◽  
Therapeutic Efficacy ◽  
Low Dose ◽  
Secondary Outcome ◽  
High Dose ◽  
Common Diagnosis ◽  
Group 2 ◽  
Group 1

Background: To compare the efficacy of low dose (Dhaka regimen) vis-a vis high dose (Pritchard regimen) magnesium sulphate in management of eclampsia and impending eclampsia.Methods: The open-label, comparative study was conducted on 90 pregnant patients. They were admitted to emergency Department of Obstetrics and Gynaecology, Government Medical College, Amritsar with eclampsia or impending eclampsia. 10 patients dropped out at various stages of study and finally, 80 were enrolled and randomized (1:1 ratio) into two groups. Group-1, N=40 were given low dose MgSO4 (Dhaka regime) and Group-2, N=40 were given high dose MgSO4 (Pritchard). Termination of pregnancy was done as per Bishop’s score, gestation age, maternal and fetal status. Primary outcome measure was therapeutic efficacy of equivalence for control of seizures whereas secondary outcome was adverse side-effects of both the regimens.Results: Mean age in Group-1 was 24.90±4.02 years and that of Group-2 was 25.67±3.79 years. Antepartum eclampsia was the most common diagnosis among groups i.e., 47.5% and 55% respectively. After treatment, the seizure control was 97.5% in Group-1 and 100% in Group-2 with comparable results (𝑥2=1.013; p=0.314). However, highly significant difference was observed among dosage of MgSO4 that was required for control of seizure (23.75±2.71 gm versus 41.35±4.76 gm; p<0.001). Group-1 showed lower incidence of side-effects that is, loss of deep tendon reflex as compared to Group-2, but neonatal outcomes were comparable in both groups.Conclusions: Low dose (Dhaka regimen) was equally effective in control of seizures as compared to high dose (Pritchard regimen) with lower incidence of side-effects.

scholarly journals Comparative evaluation of oral corticosteroids versus low molecular weight heparin in the treatment of lichen planus

2019 ◽  
Vol 5 (2) ◽  
pp. 307
Author(s):  
Narendar Gajula ◽  
Anusha Kalikota ◽  
Vontela Rohit ◽  
Hiba Shakeer
Keyword(s):  
Molecular Weight ◽  
Side Effects ◽  
Lichen Planus ◽  
Low Molecular Weight Heparin ◽  
Low Dose ◽  
Low Molecular Weight ◽  
Oral Corticosteroids ◽  
Group 2 ◽  
Group 1

<p class="abstract"><strong>Background:</strong> Lichen planus (LP) is an immunologically mediated inflammatory disorder involving the skin, nails, hair follicles and mucous membranes. Though several drugs and phototherapy are tried and mentioned in the literature, dermatologists are still depending on corticosteroids, which have various serious side effects on long term usage. Thus, in search for an alternative therapy, the present study is conducted to compare the efficacy of systemic corticosteroids and low dose low molecular weight heparin in management of lichen planus.</p><p class="abstract"><strong>Methods:</strong> 60 patients with biopsy proven LP were selected and divided randomly into two groups with 30 patients each. Group 1 was treated with oral corticosteroids and group 2 was treated with low molecular weight heparin for 8 weeks. Follow up was done for a period of 6 months, at monthly intervals in all patients and any relapses if any were noted.<strong></strong></p><p class="abstract"><strong>Results:</strong> 60 patients with biopsy proven LP were selected and divided randomly into two groups with 30 patients each. Group 1 was treated with oral corticosteroids and group 2 was treated with low molecular weight heparin for 8 weeks. Follow up was done for a period of 6 months, at monthly intervals in all patients and any relapses if any were noted.</p><p class="abstract"><strong>Conclusions:</strong> Low dose enoxaparin in the treatment of lichen planus could be considered as an alternative to oral corticosteroids because of equal efficacy and fewer side effects.</p>

scholarly journals Low-dose corticosteroid and mycophenolate for primary treatment of minimal change disease

QJM ◽  
2019 ◽  
Vol 113 (6) ◽  
pp. 399-403
Author(s):  
M K M Ma ◽  
D Y H Yap ◽  
C L Li ◽  
M M Y Mok ◽  
G C W Chan ◽  
...  
Keyword(s):  
Minimal Change Disease ◽  
Low Dose ◽  
Standard Dose ◽  
Minimal Change ◽  
Adult Onset ◽  
First Line ◽  
Group 2 ◽  
Enteric Coated ◽  
Dose Corticosteroid ◽  
Group 1

Abstract Background Mycophenolate has been shown to be effective in glomerular disease. However, the role of mycophenolate in the first-line treatment of adult-onset idiopathic minimal change disease (MCD) has not been systematically studied in a randomized fashion. Aim To evaluate the therapeutic efficacy of enteric-coated mycophenolate sodium combined with low-dose corticosteroid as first-line treatment for MCNS. Design A prospective, open-label, randomized clinical trial. Methods Twenty adult patients with biopsy proven MCD were recruited and randomly assigned to receive either enteric-coated Mycophenolate Sodium (EC-MPS) plus low-dose prednisolone (Group 1: Prednisolone 0.25 mg/kg/day, n = 10) or standard-dose prednisolone (Group 2: Prednisolone 1 mg/kg/day, n = 10). Results After 24 weeks of therapy, eight patients in Group 1 vs. seven of patients in Group 2 achieved complete remission (P = 0.606). Both groups showed a significant reduction of urine protein excretion (P &lt; 0.05) and increased serum albumin (P &lt; 0.001) vs. baseline levels. However, no significant between-group differences were demonstrated. The relapse rate was also similar in both groups. Both treatment regimens were well tolerated but there were more patient reported adverse effects in the standard-dose prednisolone group. Conclusion EC-MPS plus low-dose prednisolone is non-inferior to standard-dose prednisolone therapy in inducing clinical remission and preventing relapse in adult-onset idiopathic MCD and is associated with better tolerability and less adverse effects. This trial is registered with the ClinicalTrials.gov number NCT01185197.

Comparison of the Effects of Low Dose Methylprednisolone and Metoclopramide on Nausea and Vomiting and Respiratory Complications after Adenotonsillectomy

2021 ◽  
Vol 15 (9) ◽  
pp. 2753-2756
Author(s):  
Shahid Adalat Chaudhry ◽  
Madiha Zafar ◽  
Usman Zeeshan ◽  
Mubashar Iqbal ◽  
Arooj Fatima ◽  
...  
Keyword(s):  
Side Effects ◽  
Pain Score ◽  
Low Dose ◽  
Operative Time ◽  
Oral Intake ◽  
Respiratory Complications ◽  
Group I ◽  
Male Patients ◽  
Group Ii ◽  
Mean Time

Objective: The aim of this study is to compare the effects of low dose methylprednisolone and metoclopramide on nausea, vomiting and respiratory complications after adenotonsillectomy. Study Design: Retrospective study Place and Duration: The study was conducted in Divisional Headquarter Teaching Hospital, Mirpur AJK for duration of six months from December 2020 to May 2021. Methods: Total 150 patients of both genders underwent adenotonsillectomy presented in this study. Patients were aged between 3-15 years. Detailed demographics of enrolled cases age, sex and weight were recorded after taking informed written consent. Patients were equally divided into two groups. Group I had 75 patients and received 1 mg/kg IV methylpredinosolone and group II received 0.15 mg/kg metoclopramide among 75 patients. Post-operative effects on PONV were assessed and compared among both groups in terms of oral intake time, vomiting episodes, respiratory complications and side effects. Mean pain score was calculated by VAS. Complete data was analyzed by SPSS 23.0 version. Results: There were 40 (53.3%) females and 35 (46.7%) males in group I with mean age 9.43±1.44 years while in group II 42 (56%) were females and 33 (44%) were male patients with mean age 8.04±3.36 years. Mean weight of the patients in group I was 23.08±4.61 kg and in group II mean body weight was 22.11±6.84 kg. Mean operative time in group I was 27.41±8.53 min and in group II mean time was 28.17±6.34 min. Post-operative frequency of vomiting and nausea was lower in group I 14 (18.7%) and 16 (21.3%) as compared to group II 21 (28%) and 24 (34%). Low pain score was found in group I 1.71±6.11 as compared to group II 3.02±4.09. Time to oral intake was higher in group II 2.98±3.48 hours as compared to group I 1.09±7.51 hours. Rate of respiratory complications and side effects were significantly higher in group II. Conclusion: We concluded in this study that the use of methylpredinosolone was effective among patients those underwent for adenotonsillectomy in terms of post-operative frequency of PONV, pain, respiratory complications and side effects. Except this low dose of methylpredinosolone were effective in earlier tolerance of oral intake. Keywords: Adenotonsillectomy, Metoclopramide, Methylpredinosolone, Oral Intake

scholarly journals Ischemia-reperfusion histopathology alterations of the rabbit intestinal wall with and without exclusion of the collateral mesenteric circulation supply

2010 ◽  
Vol 25 (4) ◽  
pp. 318-321 ◽  
Author(s):  
Otoni Moreira Gomes ◽  
Geraldo Brasileiro Filho ◽  
Luiz Alberto Bomjardim Porto ◽  
Pedro Henrique de Lima Prata ◽  
Rafael de Mattos Paixão
Keyword(s):  
Small Bowel ◽  
Mesenteric Artery ◽  
Collateral Circulation ◽  
Ischemia Reperfusion ◽  
Celiac Artery ◽  
Artery Occlusion ◽  
Intestinal Wall ◽  
Group I ◽  
Group 2 ◽  
Group 1

PURPOSE: To evaluate the histopathology alterations of the intestinal mucosa of rabbits submitted to different times of mesenteric artery ischemia and reperfusion with and without celiac artery collateral circulation supply. METHODS: Two groups of eight male New Zealand white rabbits (weight 2.2-3.5 kg) were used in this study. In the Group 1 animals, the proximal mesenteric artery was occluded for 60 min with an atraumatic vascular clamp, followed by reperfusion for 60 min. In the Group 2 animals the small bowel and mesentery were cut 30cm and 60cm far from the gastroduodenal pyloric transition before the proximal mesenteric artery occlusion. Small bowel biopsies were obtained before ischemia (control), after 30 min and 60 min of mesenteric ischemia and at 30 and 60 min. of mesenteric artery reperfusion. RESULTS: In the Group I animals, the followings histopathology grade results were observed: t1, mean 0.4 + 0.29; t2, mean 1.9 ± 0.38; t3, 1.9 ± 0.33; t4, 1.2 ± 0.36 and t5, 1.2 ± 0.32. Differences between t0 and t2 and between t3 and t4 were statistically significant (p<0.05). Differences between t2 and t3 and t4 and t5 were not significant (p>0.5). In the Group II animals, it was observed: t1, mean 1.6 ± 0.33; t2, 2.4 ± 0.36; t3, 3.0 ± 0.35; t4 3.4 ± 0.31; t5, 3 ± 031. Differences between t0 and t1, t1 and t2, and t2 and t3 were significant (p<0.05). Differences between histopathology grades results of samples t1 to t5 in Group 1 and 2 were statistically significant (p<0.5). CONCLUSION: Microscopic examination of the biopsies revealed significant evidence of worse small bowel wall ischemia-reperfusion lesions by exclusion of the celiac artery collateral circulation supply.

scholarly journals Effect of anterior capsular polishing on the incidence of YAG capsulotomy

2016 ◽  
Vol 11 (3) ◽  
Author(s):  
Muhammad A Ahad ◽  
Mohammad Rashad Qamar ◽  
Sameh K Hindi ◽  
Martin N Kid
Keyword(s):  
Outcome Measure ◽  
Early Postoperative Period ◽  
Controlled Study ◽  
Control Group ◽  
Anterior Capsule ◽  
Main Outcome Measure ◽  
Group I ◽  
Group 2 ◽  
One Year ◽  
Group 1

Purpose: To study the effect of anterior capsule polishing during phacoemulsification on the incidence of post operative YAG laser capsulotomy. Method: A retrospective controlled study of 159 patients who underwent uncomplicated phacoemulsification with anterior capsular polishing between October 1998 and March 2000. 169 age matched patients who underwent phacoemulsification but without anterior capsule polishing served as controls. Main outcome measure: Incidence of visually significant YAG capsulotomy, which improved the Snellen acuity for more than 1 line or at least 1 line with subjective improvements in symptoms. Results: 2.51 % of patients with anterior capsular polishing (Group 1) had YAG capsulotomy compared to 7.1% of patients in control group at one year. However, after two years, 11.3% of patients in Group I had YAG capsulotomy compared to 12.4% in Group 2. Conclusion: Anterior capsular polishing during cataract surgery may delay the opacification of posterior capsule during the early postoperative period. But does not decrease the incidence of YAG capsulotomy after two years.

scholarly journals Factors associated with rs1801394 of the methionine synthase reductase gene polymorphism in patients with rheumatoid arthritis

2021 ◽  
Vol 15 (3) ◽  
pp. 15-19
Author(s):  
M. Yu. Krylov ◽  
G. I. Gridneva ◽  
Yu. V. Muravyev
Keyword(s):  
Rheumatoid Arthritis ◽  
Clinical Characteristics ◽  
Methionine Synthase ◽  
Nucleotide Polymorphisms ◽  
Allelic Discrimination ◽  
Methionine Synthase Reductase ◽  
Reductase Gene ◽  
Group 2 ◽  
The Relationship ◽  
Group 1

Clinical response to methotrexate (MT) therapy in rheumatoid arthritis (RA) can be predicted on the basis of some single nucleotide polymorphisms (SNPs) of genes, involved in folate metabolism. One of these SNPs is the rs1801394 (A66G) polymorphism of the methionine synthase reductase gene (MTRR). We investigated the association of this polymorphism with the clinical characteristics of RA patients after 6 months of MT therapy. Studies of the relationship between the response to MT therapy and the rs1801394 polymorphism have not been carried out in Russia previously.Objective: to study the possible association of the rs1801394 polymorphism with the clinical characteristics of patients with RA after 6 months of MT therapy.Patients and methods. The study included 60 patients with RA who met the ACR / EULAR criteria (2010) and received≥20 mg MT per week continuously. Based on the EULAR criteria, patients were divided into two groups: group 1 (n=30) with a good (DAS28>1.2) and group 2 (n=30) with an unsatisfactory (DAS28 <1.2) response to MT therapy. Genotyping of the rs1801394 polymorphism was performed by allelic discrimination using real-time polymerase chain reaction.Results and discussion. The frequency distribution of the A66G polymorphism genotypes in both groups was similar, however, in the 2nd group with an unsatisfactory response, there was a tendency towards a higher frequency of the mutant GG genotype (p=0.067). An association of the A66G polymorphism with gender and disease duration was found. In group 1, the AG genotype was more often detected in men than in women (p=0.017). In group 2, the AG genotype was also more common in men (p=0.075). In addition, in this group, carriers of the G allele (genotypes AG and GG) had a longer duration of the disease than carriers of the AA genotype (p=0.003 and p=0.005, respectively).Conclusion. In the present study, the relationship of the studied polymorphism rs1801394 of the MTRR gene with gender and duration of RA disease was established.

scholarly journals Low Dose X-Ray Sources and High Quantum Efficiency Sensors: The Next Challenge in Dental Digital Imaging?

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Arnav R. Mistry ◽  
Daniel Uzbelger Feldman ◽  
Jie Yang ◽  
Eric Ryterski
Keyword(s):  
Low Dose ◽  
Image Resolution ◽  
X Ray ◽  
Imaging Technologies ◽  
Group 4 ◽  
X Ray Imaging ◽  
Group 3 ◽  
Group 5 ◽  
Group 2 ◽  
Group 1

Objective(s). The major challenge encountered to decrease the milliamperes (mA) level in X-ray imaging systems is the quantum noise phenomena. This investigation evaluated dose exposure and image resolution of a low dose X-ray imaging (LDXI) prototype comprising a low mA X-ray source and a novel microlens-based sensor relative to current imaging technologies.Study Design. A LDXI in static (group 1) and dynamic (group 2) modes was compared to medical fluoroscopy (group 3), digital intraoral radiography (group 4), and CBCT scan (group 5) using a dental phantom.Results. The Mann-Whitney test showed no statistical significance(α=0.01)in dose exposure between groups 1 and 3 and 1 and 4 and timing exposure (seconds) between groups 1 and 5 and 2 and 3. Image resolution test showed group 1 > group 4 > group 2 > group 3 > group 5.Conclusions. The LDXI proved the concept for obtaining a high definition image resolution for static and dynamic radiography at lower or similar dose exposure and smaller pixel size, respectively, when compared to current imaging technologies. Lower mA at the X-ray source and high QE at the detector level principles with microlens could be applied to current imaging technologies to considerably reduce dose exposure without compromising image resolution in the near future.

Relationships between follicle-stimulating hormone, follicle growth and ovulation rate in sheep

1996 ◽  
Vol 8 (2) ◽  
pp. 279 ◽  
Author(s):  
RC Fry ◽  
MA Driancourt
Keyword(s):  
Follicle Stimulating Hormone ◽  
Follicular Phase ◽  
Oestrous Cycle ◽  
Ovulation Rate ◽  
Follicle Growth ◽  
Group I ◽  
Group 3 ◽  
Group 2 ◽  
Group 1 ◽  
Stimulating Hormone

The changes in follicle-stimulating hormone (FSH) concentration required to affect follicle growth and ovulation rate within individual ewes were examined. Relationships between peripheral FSH concentrations during the late-luteal and follicular phase and subsequent ovulation rates were investigated in 22 ewes from 4 breeds over 3 successive cycles (Experiment 1). Ewes were grouped as follows: Group 1 (n = 6), ewes exhibiting the same ovulation rate at each oestrous cycle: Group 2 (n = 5), ewes with three different ovulation rates at each oestrous cycle; and Group 3 (n = 11), ewes with the same ovulation rate at two oestrous cycles and a different ovulation rate on one occasion. Data from ewes in Group 1 and 3 provided estimates on the variation in FSH concentrations between cycles which were not large enough to alter ovulation rate (range, 0-67% variation in FSH concentration). In Group-2 ewes, there was no consistent association between increases in ovulation rate and the proportional increases in FSH concentrations. Differences in FSH concentrations were often less than those that did not alter ovulation rate in Group-I ewes. Furthermore, only 3 of 11 Group-3 ewes demonstrated high FSH concentrations associated with high ovulation rate (or low FSH concentrations and low ovulation rate) when compared with the concentrations found at the two cycles in which ovulation rate was similar. Hence, there was little evidence that FSH concentrations during the late-luteal and follicular phase are associated with changes in ovulation rate within individual ewes. In Experiment 2, follicles of similar size obtained from the same ewe (FecBFec+ and Romanov) showed markedly different responses in vitro to graded doses of FSH as measured by aromatase activity. It is concluded that, within a ewe, the large variability between gonadotrophin-dependent follicles in their requirement for FSH prevented the expression of any thresholds of ovarian response to FSH.

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