Biomedical subjects

J Hernandez

Publications and source records attributed to J Hernandez.

At least 37 records · Page 2Linked to original sources

PubMed2002

Prostate cancer screening at an equal access tertiary care center: its impact 10 years after the introduction of PSA.

INTRODUCTION AND OBJECTIVES: Dwight D. Eisenhower Army Medical Center has been involved in Prostate Cancer Awareness Week (PCAW) screening during the period 1995-2000. The purpose of this study is to review the results of screening in a self-selected population of military beneficiaries at our institution. MATERIALS AND METHODS: Screening involving a brief urologic history, digital rectal examination (DRE) and serum prostatic specific antigen (PSA) measurement was offered to our screening population. Patients with an elevated PSA (>4.0 ng/ml) and/or a suspicious DRE were considered for transrectal ultrasonography with prostate needle biopsy (TRUS/PNB). Patient health records were reviewed retrospectively and analyzed to determine patient demographic characteristics, PSA distribution, DRE results and cancer detection rates. RESULTS: A total of 455 screening visits were performed from 1995 to 2000, of which 426 visits were included for analysis. Mean age of the study population was 57.4 y (40-83). Seventy-one percent of the patients reported prior PSA screening visits. Forty-four patients met indications for biopsy. A total of 30 TRUS/PNB were performed demonstrating presence of cancer in three patients for an overall cancer detection rate of 0.7%. CONCLUSIONS: Our study shows that the overall prostate cancer detection rate at our institution is lower than detection rates previously reported in the literature. Potential reasons for this finding may include that the subjects participating in PCAW screening tended to be younger than in other series and that a majority of them had already undergone prior screening. These findings suggest the need to modify prostate cancer screening recommendations and to improve prostate cancer screening efficacy.

Adult↗

PubMed2002

Insulin-like growth factor-I and insulin-like growth factor binding protein-2 and -5 in equine seminal plasma: association with sperm characteristics and fertility.

The objectives of this study were 1) to determine whether insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding proteins (IGFBPs) were present in seminal plasma of stallions; 2) to compare semen parameters (IGF proteins, sperm numbers, morphology, and motility) from stallions at sexual rest (SR) and when sexually active (SA); 3) to compare semen parameters between stallions with high and low seminal plasma IGF-I concentrations; and 4) to examine the relationship between seminal plasma IGF-I concentrations and fertility parameters of stallions. Ejaculates were collected from stallions at SR (n = 51) and SA (n = 46). Concentrations of IGF-I and IGFBP-2 in seminal plasma samples were determined by radioimmunoassay. Presence of IGFBPs in equine seminal plasma was verified using immunoprecipitation and Western ligand blot procedures. IGF-I, IGFBP-2, and IGFBP-5 were present in equine seminal plasma. Concentrations of IGF-I, IGF-I/protein, total IGF-I, IGFBP-2, IGFBP-2/protein, and total IGFBP-2 were not significantly different (P > or = 0.13) in seminal plasma between stallions at either SR or SA. At SR, stallions with higher seminal plasma IGF-I had more total IGFBP-2 per ejaculate (P < 0.01), more morphologically normal sperm (P = 0.05), and higher first-cycle pregnancy rates (P = 0.02). At SA, stallions with higher seminal plasma IGF-I had fewer cycles per pregnancy (P = 0.02). An association of seminal plasma IGF-I concentration with sperm motility, sperm morphology, and pregnancy rates in bred mares suggests that IGF-I may play a role in sperm function.

Animals↗

PubMed2001

Sarco/endoplasmic reticulum calcium ATPase-2 expression is regulated by ATF6 during the endoplasmic reticulum stress response: intracellular signaling of calcium stress in a cardiac myocyte model system.

The recently described transcription factor, ATF6, mediates the expression of proteins that compensate for potentially stressful changes in the endoplasmic reticulum (ER), such as reduced ER calcium. In cardiac myocytes the maintenance of optimal calcium levels in the sarcoplasmic reticulum (SR), a specialized form of the ER, is required for proper contractility. The present study investigated the hypothesis that ATF6 serves as a regulator of the expression of sarco/endoplasmic reticulum calcium ATPase-2 (SERCA2), a protein that transports calcium into the SR from the cytoplasm. Depletion of SR calcium in cultured cardiac myocytes fostered the translocation of ATF6 from the ER to the nucleus, activated the promoter for rat SERCA2, and led to increased levels of SERCA2 protein. SERCA2 promoter induction by calcium depletion was partially blocked by dominant-negative ATF6, whereas constitutively activated ATF6 led to SERCA2 promoter activation. Mutation analyses identified a promoter-proximal ER stress-response element in the rat SERCA2 gene that was required for maximal induction by ATF6 and calcium depletion. Although this element was shown to be responsible for all of the effects of ATF6 on SERCA2 promoter activation, it was responsible for only a portion of the effects of calcium depletion. Thus, SERCA2 induction in response to calcium depletion appears to be a potentially physiologically important compensatory response to this stress that involves intracellular signaling pathways that are both dependent and independent of ATF6.

Activating Transcription Factor 6↗

PubMed2001

Phenotypic and functional analysis of CD8(+) T cells undergoing peripheral deletion in response to cross-presentation of self-antigen.

Not all T cells specific for autoantigens are eliminated in the thymus, and therefore alternate mechanisms are required to prevent potentially autoreactive T cells from developing into effectors. Adoptive transfer of CD8(+) T cells from influenza hemagglutinin-specific Clone 4 TCR transgenic mice into mice that express hemagluttinin in the pancreatic islets results in tolerance. This is preceded by activation of Clone 4 T cells that encounter antigen cross-presented in the draining lymph nodes of the pancreas. In this report we compare the phenotype, function, and costimulatory requirements of Clone 4 T cells activated by endogenous self-antigen, with Clone 4 T cells stimulated by influenza virus. The cells undergoing tolerance upregulate both CD69 and CD44, yet only partially downregulate CD62L, and do not express CD49d or CD25. Most importantly, they lack the ability to produce interferon-gamma in response to antigen and show no cytolytic activity. Clone 4 T cells disappear after several cycles of division, apparently without leaving the site of initial activation. Surprisingly, despite the fact that such stimulation occurs through recognition of antigen that is cross-presented by a professional antigen-presenting cell, we find this activation is not dependent on costimulation through CD28. These data demonstrate that the recognition by naive CD8(+) T cells of cross-presented self-antigen results in localized proliferation and deletion, without the production of effector cells.

Animals↗

PubMed2001

Association between exposure to Neospora caninum and milk production in dairy cows.

OBJECTIVE: To determine association between exposure to Neospora caninum and milk production in dairy cows. DESIGN: Prospective observational study. ANIMALS: 565 Holstein cows. PROCEDURE: Cows were classified as seropositive or seronegative to N. caninum within 7 days after calving by use of a kinetic ELISA. Milk production was compared between seropositive and seronegative cows. RESULTS: On the basis of 305-day mature equivalent milk production data, seropositive cows produced less milk (2.8 lb/cow per day) than did seronegative cows. In addition, analysis of results throughout the first 300 days of lactation revealed that after adjusting for effects of lactation number, calving season, clinical mastitis, and lameness, milk weight of seropositive cows was 2.5 lb/cow per day less than that of seronegative cows. CONCLUSIONS AND CLINICAL RELEVANCE: Exposure to N. caninum was associated with a 3 to 4% decrease in milk production. A decrease in milk production of 800 lb/cow for a typical 305-day lactation represents a loss of $128/cow.

Animals↗

PubMed2001

Thymidine analog and multinucleoside resistance mutations are associated with decreased phenotypic susceptibility to stavudine in HIV type 1 isolated from zidovudine-naive patients experiencing viremia on stavudine-containing regimens.

Studies have demonstrated that HIV-1 isolated from subjects experiencing virologic failure on stavudine (d4T)-containing regimens often contains thymidine analog mutations (TAMs), consisting of reverse transcriptase (RT) mutations M41L, D67N, K70R, L210W, T215Y/F, and K219Q/E, previously associated only with zidovudine (ZDV) resistance. In clinical study NZT40012, HIV-1 was isolated from 86 ZDV-naive subjects experiencing viremia on d4T-based therapies (plasma HIV-1 RNA > or =1000 copies/ml) and analyzed to examine the association between RT mutations and phenotypic resistance to d4T. Resistance-associated mutations were analyzed from HIV-1 isolated from 85 subjects. Of these, 24 samples (28%) had TAMs, and 30 samples (35%) had either TAMs and/or the Q151M multinucleoside resistance (MNR) mutation. Phenotypic susceptibility to d4T was determined by two commercially available methods. Statistically significant increases (p < 0.001) in phenotypic fold resistance to d4T were observed in virus with at least one TAM or MNR mutation. However, the mean increases in phenotypic resistance were 4-fold for the Antivirogram assay and 3-fold for the Phenosense HIV assay, only slightly above the levels used to designate decreased susceptibility to d4T. Subjects can experience viremia on d4T-containing regimens with virus exhibiting only small increases in IC(50), suggesting that relatively small changes in viral susceptibility to d4T may influence drug efficacy.

Anti-HIV Agents↗

PubMed2001

Effect of lameness on the calving-to-conception interval in dairy cows.

OBJECTIVE: To examine the relationship between lameness and the duration of the interval from calving to subsequent conception in lactating dairy cows. DESIGN: Cohort study. ANIMALS: 837 dairy cows. PROCEDURE: Cows affected with lameness were classified into 1 of 4 groups on the basis of types of disease or lesions observed, including foot rot, papillomatous digital dermatitis, claw lesions, or multiple lesions. Cows not affected with lameness were classified as healthy. Time from calving to conception was compared between lame cows and healthy cows. RESULTS: 254 (30%) cows were affected with lameness during lactation. Most lame cows (59%) had claw lesions. Lame cows with claw lesions were 0.52 times as likely to conceive as healthy cows. Median time to conception was 40 days longer in lame cows with claw lesions, compared with healthy cows. Number of breedings per conception for lame cows with claw lesions was significantly higher than that for healthy cows. CONCLUSION AND CLINICAL RELEVANCE: Claw lesions were the most important cause of lameness, impairing reproductive performance in dairy cows, as indicated by a higher incidence of affected cows and a greater time from calving to conception and a higher number of breedings required per conception, compared with healthy cows.

Animals↗

PubMed2001

Race-start characteristics and risk of catastrophic musculoskeletal injury in Thoroughbred racehorses.

OBJECTIVE: To identify race-start characteristics associated with catastrophic musculoskeletal (MS) injury in Thoroughbred racehorses at 2 racetracks in Florida during 1995 through 1998. DESIGN: Matched case-control study. ANIMALS: 97 Thoroughbreds (case horses) that incurred a catastrophic MS injury during racing and 388 Thoroughbreds (control horses) randomly selected from noninjured participants and matched on the basis of racetrack and year. PROCEDURE: Incidence of MS injury was calculated for all race meets at 2 racetracks in Florida from 1995 through 1998. Race-start characteristics were compared among case and control horses, using conditional logistic regression. RESULTS: Overall incidence of MS injury was 1.2/1,000 race starts (97/79,416 starts). Incidence of injury was significantly higher for turf races (2.3/1,000 starts) than for dirt races (0.9/1,000 starts). Sex, number of days since last race, and racing surface were associated with risk of injury; geldings, > or = 33 days since the last race, and turf racing surface were associated with a higher risk of injury. CONCLUSIONS AND CLINICAL RELEVANCE: Incidence of injury among Thoroughbreds in Florida was associated with sex, number of days since last race, and racing surface. Days since last race may have been an indicator of previous health and lameness problems. Racing surface may have been a risk factor for MS injury because turf races tended to be more competitive than dirt races. Horses running in turf races were more likely to participate in races with a large field, handicap races, long races, and races with high purses.

Animals↗

PubMed2001

Diazepam increases the hypothalamic-pituitary-adrenocortical (HPA) axis activity by a cyclic AMP-dependent mechanism.

1. Previous studies in this laboratory have shown that diazepam behaves as a phosphodiesterase 4 (PDE 4) inhibitor. It has been reported that PDE-4 inhibitors activate the hypothalamic-pituitary-adrenocortical (HPA) axis in the rat. In the present study we have examined whether activation of the cyclic AMP-dependent protein kinase (PKA) is involved in the effect of diazepam on basal HPA axis activity. 2. Acute systemic administration of diazepam (10 mg kg(-1) i.p.) was found to increase the basal HPA axis activity, increasing the plasma concentrations of corticotrophin (ACTH) and corticosterone 30 min post injection. Diazepam also elevated cyclic AMP content of the hypothalamus. 3. Pretreatment of the animals with dexamethasone (1 mg kg(-1) s.c.) for 3 days completely abolished the effect of diazepam on HPA axis activity. 4. The antagonists of central and peripheral benzodiazepine receptors, flumazenil (10 mg kg(-1) i.p.) and PK 11195 (5 mg kg(-1) i.p.) did not affect the diazepam induced increase of HPA axis activity nor did they have an effect per se. 5. The increase in ACTH and corticosterone levels was significantly reduced by the cyclic AMP-dependent protein kinase (PKA) inhibitor, H-89, given either subcutaneously (5 mg kg(-1) s.c.) or intracerebroventricularly (i.c.v.; 28 microg in 10 microl). 6. The results indicate that diazepam can stimulate basal HPA axis activity in the rat by a cyclic AMP-dependent PKA mediated pathway.

Adrenal Cortex↗

PubMed2001

Improvement in asthma symptoms and quality of life in pediatric patients through specialty care delivered via telemedicine.

Asthma is the most common chronic disease affecting children. Studies have demonstrated improvements in asthma control when care is delivered by specialists compared with generalists. We postulated that specialist care delivered by telemedicine would result in similar improvements in control of symptoms and quality of life as compared with face-to-face encounters with specialists. Seventeen patients with persistent asthma, who were cared for by pediatricians in a rural school-based health clinic, were treated over a 6-month period in an asthma specialty program. Patients had face-to-face encounters at week zero, and then telemedicine follow-up visits at weeks 4, 12, and 24. Patients maintained a symptom diary and reliever medication use log. Spirometry and patient and caregiver quality-of-life questionnaires were completed at each visit. Mean number of symptom free days increased 83% from 2.35 days at week 0 to 4.31 days at week 24 (p < 0.05). There was a 44% reduction in mean symptom scores, from 2.32 at week 0 to 1.31 at week 24 (p < 0.001). Nine patients reported having 7 symptom-free days or 7 days of symptom scores of zero in the preceding seven days at week 24 compared with one patient at week 0 (p < 0.002). FEV(1) increased by > or = 12% in seven patients during the study period. Significant improvements in quality of life were reported by patients at week 4 (p < 0.02) and week 24 (p < 0.01), and by caregivers at week 24 (p < 0.002). Specialty asthma care delivered via telemedicine resulted in improvements in asthma symptom control and quality of life similar to improvements reported in face-to-face encounters provided by specialists.

Adolescent↗

PubMed2001

Specification of neurotransmitter receptor identity in developing retina: the chick ATH5 promoter integrates the positive and negative effects of several bHLH proteins.

Genetic studies in Drosophila and in vertebrates have implicated basic helix-loop-helix (bHLH) transcription factors in neural determination and differentiation. In this report, we analyze the role that several bHLH proteins play in the transcriptional control of differentiation in chick retina. Our experimental system exploits the properties of the promoter for the beta 3 subunit of the neuronal acetylcholine receptors, important components of various phenotypes in the CNS of vertebrates. The beta 3 subunit contributes to define ganglion cell identity in retina and its promoter, whose activation is an early marker of ganglion cell differentiation, is under the specific control of the chick atonal homolog ATH5. Functional analysis of the ATH5 promoter indicates that interactions between ATH5 and several other bHLH transcription factors underlie the patterning of the early retinal neuroepithelium and form a regulatory cascade leading to transcription of the gene for beta 3. ATH5 appears to coordinate the transcriptional pathways that control pan-neuronal properties with those that regulate the subtype-specific features of retinal neurons.

Amino Acid Sequence↗

PubMed2001

Training failure among yearling horses.

OBJECTIVE: To compare financial returns between pinhooked yearling horses (ie, bought and trained for approximately 5 months with the goal of selling the horse at "2-year-olds in training" sales) that had mild or severe training failure and horses that had planned versus nonplanned training failure. ANIMALS: 40 Thoroughbred pinhooked yearling horses. PROCEDURE: During the period from September 1998 through and April 1999, 20 horses had mild training failure (1 to 11 days lost), and 20 horses had severe training failure (13 to 108 days lost). Horses were assigned to these 2 groups on the basis of frequency distribution (median) of days lost during training. Horses were also categorized on the basis of type of training failure (planned vs nonplanned training failure). The outcome of primary interest was financial return. Median financial returns were compared among groups by use of the Mann-Whitney U test. RESULTS: Median financial returns for horses that had severe training failure ($1,000) were significantly different, compared with horses that had mild training failure ($24,000). Analysis of results also indicated that median returns were significantly different among horses that had planned training failure (-$2,000; eg, horses with radiographic abnormalities detected during routine prepurchase examinations that required surgical treatment, resulting in days lost during training), compared with horses that did not ($10,000). CONCLUSIONS AND CLINICAL RELEVANCE: Training failure has an economic impact on revenues in pinhooked yearling horses. Lameness, planned training failure, respiratory disease, and ringworm were common and important causes of training failure.

Animals↗

PubMed2000

Recombinant Cry3Aa has insecticidal activity against the Andean potato weevil, Premnotrypes vorax.

The Andean potato weevil, Premnotrypes vorax, an insect of the order Coleoptera, is a major cause of damage to potato crops in the Andean regions of South America. The insecticidal Cry proteins from Bacillus thuringiensis are useful biological pesticides, and some are toxic to Coleopteran insects. We overexpressed recombinant, histidine-tagged Cry3Aa protein in Escherichia coli host cells. The recombinant protein was solubilized at high pH with urea, purified using Ni(2+)-nitrilo-triacetic acid affinity resin, and dialysed to lower pH and remove urea. Bioassays were performed with an insect media whose surface was spread with 70 microgram/mL purified native or recombinant toxins. First instar larvae exposed to toxin treated media for 5 days exhibited mortalities from 57% (native Cry3Aa) to 52% (recombinant Cry3Aa). Purified native and recombinant Cry3Aa proteins appeared to be equally toxic to the Andean potato weevil.

Animals↗

PubMed2000

Alternative glycosylation of the insulin receptor prevents oligomerization and acquisition of insulin-dependent tyrosine kinase activity.

Glucose deprivation leads to the synthesis of an aberrantly glycosylated ('alternative') and inefficiently processed form of the insulin proreceptor in 3T3-L1 adipocytes. To further explore the effect of aberrant (rather than absent) N-linked glycosylation of the insulin receptor, we examined the relationship of processing to function. Our studies show that the alternative form of the proreceptor does not oligomerize nor does it acquire the ability to undergo insulin-sensitive autophosphorylation. This along with an interaction with the glucose-regulated stress protein GRP78/BiP implies inappropriate folding/dimerization and retention in the ER. Glucose refeeding causes the post-translational modification of the alternative form of the proreceptor to a novel 'intermediate' form which is independent of new protein synthesis. As little as 100 microM glucose (or mannose) can induce this modification. In vitro digestion of the alternative and intermediate proreceptors with SPC1/furin shows that both the alpha- and beta-subunit domains are glycosylated, albeit aberrantly. This implies that the aberrantly glycosylated proreceptor could serve as a substrate for SPC1 in a physiological setting if the receptor was able to interact with the enzyme in the appropriate compartment (i.e., the trans-Golgi network). Based on inhibitor studies, however, both the alternative and intermediate forms of the proreceptor appear to be primarily targeted to the proteasome for degradation.

3T3 Cells↗

PubMed2000

Efficacy of oxytetracycline for treatment of papillomatous digital dermatitis lesions on various anatomic locations in dairy cows.

OBJECTIVE: To evaluate efficacy of topical treatment with oxytetracycline solution among dairy cows with papillomatous digital dermatitis (PDD) lesions on the interdigital cleft, heels, or dewclaw. DESIGN: Clinical trial. ANIMALS: 70 dairy cows from a single herd. PROCEDURE: On the basis of anatomic location of PDD lesions, cows were allocated into 1 of 3 groups (interdigital cleft [n = 14], heels [30], or dewclaw [26]) and treated topically with oxytetracycline solution. Cows were examined 14 and 30 days after initial treatment. During each examination, pain and lesion size scores were recorded. RESULTS: On the basis of pain and lesion size scores, oxytetracycline appeared significantly less effective among cows with lesions on the interdigital cleft than for cows with lesions on the heels or the dewclaw. Number of cows with signs of pain or visible lesions after treatment was significantly higher for cows with lesions on the interdigital cleft than for cows with lesions on heels or the dewclaw. CONCLUSIONS AND CLINICAL RELEVANCE: Anatomic location of PDD lesions has an effect on the efficacy of topical treatment with oxytetracycline solution in dairy cows affected with PDD. Cows with lesions on the interdigital cleft were less likely to respond to treatment, compared with cows with lesions on the heels or the dewclaw.

Animals↗

PubMed2000

A peptide from the adenovirus fiber shaft forms amyloid-type fibrils.

The fiber protein of adenovirus consists of a C-terminal globular head, a shaft and a short N-terminal tail. The crystal structure of a stable domain comprising the head plus a part of the shaft of human adenovirus type 2 fiber has recently been solved at 2.4 A resolution [van Raaij et al. (1999) Nature 401, 935-938]. A peptide corresponding to the portion of the shaft immediately adjacent to the head (residues 355-396) has been synthesized chemically. The peptide failed to assemble correctly and instead formed amyloid-type fibrils as assessed by electron microscopy, Congo red binding and X-ray diffraction. Peptides corresponding to the fiber shaft could provide a model system to study mechanisms of amyloid fibril formation.

Adenoviruses, Human↗

PubMed2000

Vav modulation of the Ras/MEK/ERK signaling pathway plays a role in NFAT activation and CD69 up-regulation.

Vav is expressed exclusively in hematopoietic cells and becomes phosphorylated on tyrosine in response to antigen receptor ligation. Although Vav can act as a Rac-specific guanine nucleotide exchange factor in vitro and as a c-Jun N-terminal kinase (JNK) activator in ectopic expression systems, its physiological functions in lymphocytes remain unclear. Indirect evidence suggests that Vav interacts with the Ras/ERK pathway in T cells. Here, we analyzed the effects of Vav on three known downstream targets of Ras, i. e. activation of ERK and NFAT, and up-regulation of the activation antigen CD69. The MEK inhibitor PD90859 inhibited Vav-induced activation of ERK, and Vav- or anti-CD3-induced activation of NFAT, suggesting that MEK and ERK are involved in Vav-mediated NFAT activation. Similarly to Ras, Vav cooperated with constitutively active calcineurin and with ERK to activate NFAT, and was capable of up-regulating CD69 expression in T cells. Moreover, these Vav-mediated functions were all inhibited by a dominant negative Ras mutant. Conversely, however, dominant negative Vav did not inhibit NFAT and ERK activation or CD69 expression induced by an active Ras mutant. These findings indicate that Ras functions as an important downstream target of Vav in signaling pathways that lead to NFAT and ERK activation, and to CD69 expression. Moreover, the finding that Vav- (or Ras-) induced CD69 expression was not inhibited by a dominant negative Rac mutant indicates that Vav mediates some Ras-dependent, but Rac-independent, functions in T cells.

Antigens, CD↗

PubMed2000

Comparison of synchronization of ovulation and induction of estrus as therapeutic strategies for bovine ovarian cysts in the dairy cow.

The benefit of using timed-insemination in lactating dairy cows for the treatment of ovarian cysts lies in the fact that cows do not have to be detected in estrus for insemination and achieving pregnancy. We compared the effectiveness of synchronization of ovulation with timed-insemination and induction of estrus with insemination at estrus in the treatment of bovine ovarian cysts in lactating dairy cows. After Day 65 post partum, a total of 368 lactating dairy cows was divided into 3 groups. Cows in Group 1 (n = 209, normal, noncystic) were treated with 100 ug, i.m. GnRH on Day 0; 25 mg, i.m. PGF2 alpha on Day 7; and 100 ug, i.m. GnRH on Day 9 and then were time-inseminated 16 h later. Cows in Group 2 (n = 76, abnormal, cystic) were treated with 100 ug, i.m. GnRH on Day 0; 25 mg, i.m. PGF2 alpha on Day 7; and 100 ug, i.m. GnRH on Day 9 and time-inseminated 16 h later. Cows in Group 3 (n = 83, abnormal, cystic) were treated with 100 ug, i.m. GnRH on Day 0; 25 mg, i.m. PGF2 alpha on Day 7; and inseminated at induced estrus within 7 d after treatment with PGF2 alpha. Day 0 was the day of initiation of the study. Conception and pregnancy rates among groups were compared using logistic regression and adjusted for parity, time of year and days in milk. Conception and pregnancy rates of Group 1 cows (31.5%) were not significantly different from those of Group 2 cows (23.6%). However, the pregnancy rate in normal cows (Group 1) was higher (P < 0.01) than in cystic cows (Groups 2 and 3). Cows in Group 3 had a higher conception rate than cows in Group 2 (51.7% > 23.6%; P < 0.01). However, pregnancy rates for cows in Groups 2 (23.6%) and 3 (18%) were not significantly different. The finding indicated that synchronization of ovulation and timed-insemination resulted in pregnancy rates similar to those of synchronization of estrus and insemination at an induced estrus within 7 d for the treatment of ovarian cysts in lactating dairy cows.

Animals↗