[The works of Zhang Wenzhong as the Shang Yao Feng Yu in the early Tang Dynasty].

Zhang Wenzhong, a famous Chinese medical doctor in the early Tang Dynasty, was granted a particular position as Shang Yao Feng Yu, for the Empress Wu Ze Tian dealing with medication. He was good at dealing with stroke in particular. He also had unique viewpoints towards medical prescriptions and skills. He wrote medical books and developed his own medical theories. All these were recorded in both the Book of Tang and the New Book of Tang. However, most of his works had been lost due to time and the frequent wars in the middle and late Tang Dynasty. Six medical prescriptions signed by Zhang Wenzhong were discovered in documents unearthed from the Dun Huang Sutra Cave. They were believed to be important archives of Zhang Wenzhong's writing and medical thoughts. In addition, some pieces of work found in the documents unearthed from Tu Yu Gou were suspected of being written by Zhang Wenzhong. This can be compared with his works cited in the handed-down documents, such as The Collection of Secret Prescriptions (Wai Tai Mi Yao Fang). This paper takes a textual research approach to examine the medical works of Zhang Wenzhong, comparing the handed-down documents with the unearthed documents to examine his medical achievements.

[Endovascular thrombectomy in patients with intracranial large artery occlusion and atrial fibrillation].

Objective: To investigate the safety and efficacy of mechanical thrombectomy in patients with atrial fibrillation complicated with acute intracranial arterial occlusion. Methods: Fifty-eight patients with atrial fibrillation complicated with acute intracranial arterial occlusion in the intervention group of East (Endovascular Therapy for Acute ischemic Stroke Trial) were analyzed. According to the TOAST (Trial of Org 10 172 in Acute Stroke Treatment) classification, patients were divided into ICAS (Intracranial Atherosclerotic Stenosis) group and cardiogenic embolism group. Clinical characteristics, treatment methods and clinical prognosis were compared between ICAS group and cardiogenic embolism group. Results: A total of 58 patients with atrial fibrillation complicated with acute intracranial arterial occlusion were included in this study, including 46 patients in the cardiogenic embolism group (79%) and 12 patients in the ICAS group (21%). The pre-hospital transport time in ICAS group was longer than that in cardiogenic embolism group (P<0.05).Patency rate in patients with atrial fibrillation complicated with acute intracranial arterial occlusion was 98.3% (57/58), The rate of patients with the 90-day function independent (mRS 0-2) was 51.7% (30/58). There were no statistically significant differences in functional independence, mortality rate, ICH and sICH at 90 days between the cardiogenic embolism group and the ICAS group. Conclusions: Mechanical thrombectomy is an effective method to treat patients with atrial fibrillation complicated with acute intracranial arterial occlusion.

[Efficacy analysis of LVIS and Enterprise stent assisted coil in the treatment of vertebral artery dissection aneurysm].

Objective: To observe and evaluate the therapeutic efficacy of LVIS stent and Enterprise stent assisted coil in embolization of vertebral artery dissection aneurysm (VDA). Methods: Clinical data of 96 patients with VDAs treated by LVIS stent and Enterprise stent assisted coil were analyzed retrospectively between January, 2013 and June, 2017.Of all, the LVIS stent assisted coil was performed in 28 patients (LVIS-stent group) and Enterprise in 68 patients (Enterprise-stent group). The clinical and imaging follow-up were performed. The instant embolization rate, complications, and recurrence rate were analyzed and compared between the two groups. Results: Instant angiographic results:in the LVIS stent group, complete occlusion was achieved in 17 VDAs (60.7%), near-complete occlusion in 10VDAs (35.7%), and partial occlusion in 1 VDA (3.6%). In the Enterprise stent group, complete occlusion was achieved in 27 VDAs (39.7%), near-complete occlusion in 34VDAs(50.0%), partial occlusion in 7VDAs (10.3%). Procedure-related complications occurred in 3 patients (10.7%) in LVIS stent group and 3 patients (4.4%) in Enterprise stent group. DSA follow-up was performed during 6 to 12 months after surgery, and 10 patients with vertebral artery dissection aneurysm recurred, 2 in the LVIS group and 8 in the Enterprise stent group. The latest modified Rankin Scale score was 0 in 55 patients,1 in 13, 2 in 1, 3 in 1, and 6 in 1. Among them, all follow-up patients in the LVIS stent group had good prognosis, while in the Enterprise stent group, 50 patients (94.4%) had a good prognosis. Conclusions: The stent-assisted coils have a higher degree of embolization in the vertebral artery dissection aneurysms, a higher rate of near-total embolization, a lower incidence of neurological complications, and a good prognosis. The complete andnear-complete occlusion rates and the incidence of neurological complicationsin the LVIS group was higher than that in the Enterprise groupand the recurrence ratesin the LVIS group was lower than that in the Enterprise group,both with no statistically significant difference.

[Efficacy analysis of the endovascular treatment for 175 unruptured vertebrobasilar dissecting aneurysms].

Objective: To analyze the clinical characteristics, clinical effect and follow-up outcome of the different endovascular treatment techniques in the treatment of unruptured vertebrobasilar dissecting aneurysms (VBDAs). Methods: The clinical data of 160 consecutive patients (175VBDAs) from January 2012 to December 2016 in Beijing Tiantan hospital were retrospectively analyzed.All of the 175 aneurysms were treated with endovascular embolization, including 115 stent-assisted coils, 27 simple stents, 21 blood flow diverting devices, and 12 parent arteries occlusion.The imaging and clinical follow-up were performed after the operation. Results: Headache including cervical-occipital pain(43.1%)was the most common clinical manifestation.The incidence of perioperative complications was 3.75%, no intraoperative bleeding and no deaths.The imaging findings of 113 aneurysms were followed up for (9.9±7.3) months.Of the 71 stent-assisted coils, 62 recovered well and 9 relapsed; of the 19 aneurysms treated with simple stent, 4 recovered well, 11 improved, 2 stable and 2 relapsed; of the 15 aneurysms treated by the blood flow diverting devices, 4 recovered and 11 improved; all of the 8 aneurysms with parent arteries occlusion recovered well.A total of 144 patients were follow-up (17.3±16.6) months by the Modified Rankin Scale(mRS) score: 140 patients were 0-2 score and 4 patients were 3-6 score. Conclusions: The clinical manifestations of the unruptured VBDAs are complex, and the headache is the most common clinical symptom.Endovascular treatment for the treatment of unruptured VBDAs is safe and feasible.The principle of individualization should be followed during embolization.

[Evaluating the electrophysiological features of tremor in Parkinson's disease and essential tremor using accelerometry].

Objective: To investigate the electrophysiological features of tremor intensity, frequency and frequency dispersion of Parkinsonian (PT group) and essential (ET group) tremors using accelerometry. Methods: The amplitude, frequency and frequency dispersion of rest tremor, postural tremor and the influence of weight on tremor of 35 PT patients and 40 ET patients in Department of Neurology, the Second Affiliated Hospital Zhejiang University School of Medicine from May 2015 to April 2016 were retrospectively analyzed and compared. Data of the more and less trembling hands were statistically elaborated. Results: In resting, postural and loading states, PT amplitudes of the less affected hand were smaller than the more affected one. The less affected hand were (147±32), (142±36), (157±40)µV, the more affected hand were (185±41), (164±29), (190±33)µV, respectively; ET amplitudes of the less affected hand were also smaller than the more affected one, and the less affected hand were (149±33), (157±33), (169±43)µV, the more affected hand were (176±39), (189±39), (213±36)µV, respectively; PT frequencies of the less affected hand were faster than the more affected one, with the less affected hand (6.1±1.1), (6.4±1.7), (6.5±2.0)Hz, the more affected hand (5.4±1.3), (5.5±1.1), (5.7±1.1)Hz, respectively, but ET frequencies of the less affected hand were similar to the more affected one, with the less affected hand (6.5±1.3), (7.0±1.2), (7.2±1.5)Hz, the more affected hand (7.0±1.0), (7.3±1.0), (7.6±1.1)Hz, respectively; in resting and postural states, PT frequency dispersions of the less affected hand were broader than the more affected one, the less affected hand were (2.1±0.6), (2.4±1.1)Hz, respectively; the more affected hand were (1.6±0.8), (1.7±0.9)Hz, respectively. But in loading state, PT frequency dispersions were similar in both sides (2.3±1.2, 2.2±1.1)Hz; In resting, postural and loading states, ET frequency dispersions were also similar in both two sides, the less affected hand were (2.0±1.1), (2.2±0.9), (1.9±1.0)Hz, the more affected hand were (1.8±0.6), (1.9±0.8), (2.1±0.7)Hz. Conclusions: Tremor intensity is significantly asymmetric both in PT and ET, while frequency and frequency dispersion are symmetric in ET but asymmetric in PT. Bilateral assessment of frequency related tremor parameters may be useful for differentiating ET from PT.

Huntingtin gene CAG repeat numbers in Chinese patients with Huntington's disease and controls.

BACKGROUND AND PURPOSE: Huntington's disease is due to a CAG triplet repeat elongation in the huntingtin gene. Boundaries in CAG numbers have been found between healthy people with and without risk to pass the disorder to the next generation, and between people without, with a mild, or with a fully penetrant phenotype. These data have been generated in western populations and it is not clear whether they are also valid amongst Chinese. METHODS: In order to establish normative data in the huntingtin gene for Chinese people, 966 chromosomes from normal controls were tested. Further, the range of CAG repeats was examined in a cohort from six centres and a total of 368 patients with the disease were included. RESULTS: The CAG triplet repeat range in normal controls was between 9 and 35 (mean 18.9, SD 2.57). Triplets in the range between 26 and 35 were found in 2.5%. In the patient cohort, triplet repeats in the shorter allele were between 8 and 37 (mean 17.7, SD 1.6). In the longer allele, a range between 36 and 120 was found. There was a negative correlation (-0.65, r = 0.42) between age at onset and the number of triplet repeats in the larger allele. The mean age at onset was 38 years, with a range between 2 and 70 years. In 23 patients (6%) a childhood or juvenile onset was noted. CONCLUSION: These data show comparable ranges of huntingtin gene CAG triplet repeats in normal people and in patients with Huntington's disease as in western populations.

Expression of GAI gene and disruption of PEP4 gene in an industrial brewer's yeast strain.

AIMS: Construction of an industrial brewer's yeast strain, which could improve foam stability and reduce calorific values of beer. METHODS AND RESULTS: An industrial brewer's yeast strain (Ts-10) was constructed by integrating glucoamylase encoding gene GAI amplified from Saccharomycopsis fibuligera by PCR into the locus of proteinase A (PrA) gene (PEP4). The resulting recombinant strain identified by PCR could grow on YNB minimal medium plate with starch as sole carbon source. Its highest GAI activity was 91.69 U ml(-1), but it had no PrA activity. The real extract was reduced by 21.07% and the main residual maltotriose content was reduced by 14% in wort fermented with the recombinants strain. Its foam retention in beer was higher 39 s and the contents of potential off-flavour compounds, such as diacetyl, pentanedione and acetaldehyde were lowered by 16%, 13% and 14%, respectively, as compared with the industrial brewer's yeast YSF-5. CONCLUSIONS: An industrial brewer's yeast strain was constructed by introducing GAI gene and disrupting PEP4 gene. SIGNIFICANCE AND IMPACT OF THE STUDY: The recombinant strain (Ts-10) had better foam performance and mouthfeel in addition to low-calories values. It was free of heterologous DNA sequences and drug-resistance genes and could be safely used in beer production.

Synthesis and optical properties of ZnTe single-crystalline nanowires.

Single-crystalline ZnTe nanowires with the zincblende structure have been synthesized on silicon (Si) substrates via a vapor phase transport method. The ZnTe (99.99%) powders were used as the source, and 10 nm-thick thermal evaporated gold (Au) film was used as the catalyst. The as-prepared ZnTe nanowires have diameters of 30-80 nm and lengths of more than 10 microm. The products were analyzed by X-ray diffraction, field emission scanning electron microscopy, and high-resolution transmission electron microscopy. Optical properties of these nanowires were investigated by room-temperature Raman scattering spectrum and temperature-dependent photoluminescence measurements. The results show that the as-prepared ZnTe nanowires are of high crystal quality.

Catalyst-free synthesis of well-aligned ZnO nanowires on In0.2Ga0.8N, GaN, and Al0.25Ga0.75N substrates.

Well-aligned ZnO nanowires have been synthesized vertically on In0.2Ga0.8N, GaN, and Al0.25Ga0.75N substrates, using a catalyst-free carbon thermal-reduction vapor phase deposition method for the first time. The as-synthesized nanowires are single crystalline wurtzite structure, and have a growth direction of [0001]. Each nanowire has a smooth surface, and uniform diameter along the growth direction. The average diameter and length of these nanowires are 120-150 nm, and 3-10 )m, respectively. We suggest that the growth mechanism follow a self-catalyzing growth model. Excitonic emission peaked around 385 nm dominates the room-temperature photoluminescence spectra of these nanowires. The room-temperature photoluminescence and Raman scattering spectra show that these nanowires have good optical quality with very less structural defects.

A preliminary study of chromium distribution in chromium-rich brewer's yeast cell by NAA.

The purpose of this study was to assess the chromium (Cr) distribution in chromium-rich brewer's yeast cell. The chromium concentrations in the cell wall and protoplast fractions of the chromium-rich yeast were determined by neutron activation analysis (NAA). Moreover, the combined state of chromium and amino acid content in the Cr-rich brewer's yeasts was analyzed and measured. The experimental results indicate that the introduction of water-soluble chromium(III) salt as a component of the culture medium for yeasts results in a substantial amount of chromium absorbed through the cell wall by the yeast, among which 80.9% are accumulated in the protoplast. It implies that, under optimal conditions, yeasts are capable of accumulating large amounts of chromium and incorporating chromium into organic compounds.

Glycine betaine improves survival of fresh bovine spermatozoa.

Fresh spermatozoa from bulls established as 'good freezers' and 'poor freezers' (consistently > or = 50% or < 20% motile spermatozoa after cryopreservation, respectively) were incubated for 96 h in Tes/Tris-egg yolk or TALP-egg yolk media at 37 degrees, 20 degrees , 5 degrees or 0 degrees C. The TALP extender contained 0, 100 or 200 mM glycine betaine (GB) to test the hypothesis that GB would efficiently maintain spermatozoa function during long-term incubation. The percentage of motile spermatozoa declined over time in a temperature- and medium-dependent fashion. No spermatozoa were motile by 24 h incubation at 37 degrees C or by 72 h incubation at 0 degrees C, and there were no significant differences in the percentage of motile spermatozoa from either category of bull when spermatozoa were incubated in any media for less than 24 h. Spermatozoa from poor freezers were significantly more motile than spermatozoa from good freezers after 96 h at 20 degrees or 5 degrees C in TALP alone; however, GB at both 100 and 200 mM increased the percentage of motile spermatozoa in poor and good freezers and eliminated these differences. Overall, the presence of GB at either 100 or 200 mM significantly improved the percentage of motile spermatozoa at 20 degrees, 5 degrees and 0 degrees C, but not at 37 degrees C.

Presence of the acute phase protein, bikunin, in the endometrium of gilts during estrous cycle and early pregnancy.

Noninvasive, epitheliochorial placental attachment in the pig is regulated through endometrial production of protease inhibitors. The objective of the present study was to determine if the light-chain serine protease inhibitor of the inter-alpha-trypsin inhibitor family, bikunin, is produced by the porcine endometrium during the estrous cycle and early pregnancy. Western blot analysis revealed the presence of bikunin in uterine flushings of gilts collected during the luteal phase of the estrous cycle and early pregnancy (Days 12-18). However, bikunin unbound to the inter-alpha-trypsin heavy chains was detected only in endometrial explant culture medium obtained from estrus and pregnant (Days 12, 15, and 18) gilts. Endometrial bikunin gene expression was lowest on Day 10 of the estrous cycle and pregnancy, followed by a 30- to 77-fold increase on Day 15 of the estrous cycle and pregnancy. Bikunin gene expression decreased on Day 18 of the estrous cycle, whereas endometrial bikunin gene expression continued to increase in pregnant gilts. Bikunin mRNA was localized to the uterine glands between Days 15 and 18 of the estrous cycle and pregnancy. In addition to its role as a protease inhibitor, bikunin functions in stabilization of the extracellular matrix, which suggests that bikunin could be involved with facilitating placental attachment to the uterine epithelial surface in the pig.

[Photoluminescence from Er-doped silicon-rich silicon oxide film and Er-doped silicon-rich silicon nitride film and its annealing behavior].

Room temperature photoluminescence (PL) with a peak at 1.54 microns was observed from silicon oxide, silicon-rich silicon oxide, silicon nitride and silicon-rich silicon nitride films, all doped with Er and grown by the magnetron sputtering technique. To determine the optimum annealing temperature for the 1.54 microns PL, these films were annealed in the range of 600-1,100 degrees C with an interval of 100 degrees C. Among these four types of films annealed at an identical temperature, the intensity of 1.54 microns PL peak of the Er-doped silicon-rich silicon oxide film was always the strongest one, which arrived at a maximum in 800 degrees C annealing. A 1.38 microns PL band was also observed in each of these four types of films, and which in the silicon-rich silicon oxide or silicon-rich silicon nitride films was found to be correlated with the 1.54 microns PL band in intensity.

Relationship between heparin binding to spermatozoa and the fertility of dairy bulls.

The presence of heparin in in vitro media has been implicated in improved fertility parameters of bull spermatozoa. In a previous study, Zhang et al. (25) obtained an estimate of bull nonreturn rates based on spermatozoal concentration, motility and zona pellucida binding (24). The objective of this study was to test for a relationship between fertility parameters previously estimated for the same batch of cryopreserved semen (25) and amount of heparin bound to spermatozoa. 3H-heparin binding to spermatozoa was assessed by radioimmunoassay, and statistical correlations were drawn to previously measured sperm characteristics. Preliminary experiments established optimal binding conditions of 25 degrees C, and 60 min incubation with 3H-heparin at a concentration of 50,000 cpm. 3H-heparin bound to an average of 2.2 x 10(6) receptors/cell with a Kd of 2.0 x 10(-7) M. The total 3H-heparin bound to spermatozoa from different bulls was significantly different (P<0.003). However, the total 3H-heparin bound to spermatozoa was not correlated with any measured sperm parameter, including zona pellucida binding, embryo cleavage and blastocyst formation, and 56-day nonreturn rates (P>0.19). Thus, the total amount of heparin bound to the surface of spermatozoa may not be relevant to fertilizing ability.

Prediction of bull fertility by combined in vitro assessments of frozen-thawed semen from young dairy bulls entering an AI-programme.

In the present study, we assessed the degree to which various bull sperm traits, including the ability to bind to homologous zona pellucidae (ZP) and to fertilize in vitro, were related to field fertility after AI as 56d-non-return rates (56d-NRR based upon 8620 AIs) with frozen-thawed semen from 12 Swedish Red and White young (11-13 months) bulls (3 freezing batches/bull, 1-2 consecutive ejaculates/batch), entering a national breeding program and housed at two AI-bull stations. Significant (p < 0.01) correlations among in vitro tests were found for swim-up separated spermatozoa (concentration and concentration of motile spermatozoa) with the ZP-binding assay (ZBA, r = 0.72 and r = 0.73, respectively) and blastocyst rates (r = 0.79 and r = 0.79, respectively). A strong correlation was found between cleavage and blastocyst rates (r = 0.81, p < 0.01). Whereas bull station influenced (p < 0.05-0.001) all these variables, bull only affected (p < 0.05) ZBA and cleavage. There was no significant difference in 56d-NRRs (p > 0.05, range 62-67.2%) among bulls, once the absolute NRRs had been corrected for season, area and parity. Neither bull, batch nor station had a significant effect on field fertility (p < 0.05). None of the single sperm traits/tests in vitro correlated significantly with in vivo fertility. A correlation with bull fertility was, however, found when measures of sperm traits were combined and predicted NRRs, calculated by regression analyses, were tested against observed 56d-NRRs. The predictive bull fertility, based on the tested three frozen batches, varied from 61.8 to 67.5% (p < 0.05) and was highly correlated with the observed fertility NRRs (r = 0.92, p < 0.001). Although the results suggest that the combined analyses of swim-up separated sperm traits, ZBA and IVF can be used to predict bull fertility, it might not be possible to determine the life-time fertility of a breeding sire owing to the limited number of observations made.

Mutations in the gene encoding gap junction protein beta-3 associated with autosomal dominant hearing impairment.

Hearing impairment is the most commonly occurring condition that affects the ability of humans to communicate. More than 50% of the cases of profound early-onset deafness are caused by genetic factors. Over 40 loci for non-syndromic deafness have been genetically mapped, and mutations in several genes have been shown to cause hearing loss. Mutations in the gene encoding connexin 26 (GJB2) cause both autosomal recessive and dominant forms of hearing impairment. To study the possible involvement of other members of the connexin family in hereditary hearing impairment, we cloned the gene (GJB3) encoding human gap junction protein beta-3 using homologous EST searching and nested PCR. GJB3 was mapped to human chromosome 1p33-p35. Mutation analysis revealed that a missense mutation and a nonsense mutation of GJB3 were associated with high-frequency hearing loss in two families. Moreover, expression of Gjb3 was identified in rat inner ear tissue by RT-PCR. These findings suggest that mutations in GJB3 may be responsible for bilateral high-frequency hearing impairment.

Sperm characteristics and zona pellucida binding in relation to field fertility of frozen-thawed semen from dairy AI bulls.

The present study examined the relationship between bull sperm characteristics immediately post-thaw and some characteristics registered after swim-up, including the ability of spermatozoa to bind to homologous zona pellucidae (ZP) in vitro, and fertility after artificial insemination (AI) of 9426 females. Frozen-thawed semen from 22 AI bulls of the Swedish Red and White Breed, represented by 43 different frozen batches (1-4 batches/bull, 2 consecutive ejaculates/batch), was examined with the aim of determining concentration, motility patterns, morphology and membrane integrity. In addition, the frozen-thawed spermatozoa were subjected to a swim-up procedure and those separated in this way were tested with two assays of sperm-binding to the ZP of homologous oocytes in vitro (ZBA), using either a relative ZBA index against a control bull of proven high fertility or absolute binding (Absolute ZBA). The correlations of the various sperm traits and 56-day non-return rates (NRR) after field AI were retrospectively examined as single traits and as combinations of traits (combined measures), including regression analysis of significant traits. Among the sperm characteristics, positively significant (p < 0.01) correlations with NRR were found for linear motility post-thawing (r = 0.45-0.59) and the concentration of motile spermatozoa after swim-up (r = 0.43-0.63). Results obtained with the absolute ZBA approach were significantly (p < 0.05) correlated with NRR (r = 0.50), whereas the correlation between NRR and the ZBA index was not significant. The use of combined measures of sperm traits, including the ability to bind to ZP, showed a stronger predictive correlation with NRR (r = 0.68-0.75), compared with single traits. The results suggest that the combined analysis of sperm linear-motility patterns, swim-up separated sperm motility and absolute ZBA can provide a valuable assessment of the fertilizing capacity of AI bull semen.

Expression of endothelin-1 and constitutional nitric oxide synthase messenger RNA in saphenous vein endothelial cells exposed to arterial flow shear stress.

BACKGROUND: It has long been speculated that increased blood flow shear stress might be one of the major factors affecting the patency of grafted saphenous vein in coronary artery bypass operations. The underlying cellular and molecular mechanisms for so-called "shear stress damage" have not yet been well elucidated. METHODS: Endothelial cells harvested from human saphenous vein were cultured in vitro and then exposed to a high arterial level flow shear stress in the parallel flow chamber. The expression levels of endothelin-1 and constitutional nitric oxide synthase by the endothelial cells were evaluated semiquantitatively at the gene transcription (messenger RNA) level using reverse transcription polymerase chain reaction. RESULTS: After 7 hours of exposure to arterial level shear stress, the expression of constitutional nitric oxide synthase messenger RNA by saphenous vein endothelial cells was significantly reduced, whereas the expression of endothelin-1 messenger RNA was substantially increased. These changes were more predominant at 24 hours. CONCLUSIONS: Arterial level flow shear stress could cause important changes in the gene transcription level in saphenous vein endothelial cells within a short period of time. The functional alterations of saphenous vein endothelial cells, as manifested by the increased expression of endothelin-1 and decreased expression of nitric oxide synthase messenger RNA, might play a crucial role in the vein graft remodeling process.

Relationship between embryo development in vitro and 56-day nonreturn rates of cows inseminated with frozen-thawed semen from dairy bulls.

Frozen-thawed bull semen with > 50% post-thaw motility from 40 batches (21 bulls, 2 consecutive ejaculates per batch) was used for fertilization (IVF) and embryo development in vitro to assess the relationship between field and laboratory fertility using a retrospective approach. Each frozen batch was tested in 3 or 4 replicates with 30 oocytes per replicate. Field fertility, quantified as the 56-d nonreturn rate and based on 89 to 441 artificial inseminations per frozen batch, ranged between 46.2 and 74.8%. The cleavage and blastocyst rates after IVF varied from 29.0 to 81.9% and from 1.8 to 32.0%, respectively, with significant differences among frozen batches. Rates of cleavage and blastocyst formation were significantly related to the nonreturn rate (r = 0.59, P < 0.001; r = 0.35, P < 0.05, respectively). The interaction between cleavage and blastocyst rate was 0.69 (P < 0.001). Significant variations (P < 0.05) among frozen semen batches within 15 bulls with >/= 2 different semen batches were found for the nonreturn rate (13.3%) of 2 bulls, for cleavage rates (26.7%) in 4 bulls and for blastocyst rates (20.0%) in 3 bulls. Significant differences (P < 0.05) among replicates within the 40 frozen semen batches were only found in 3 batches (7.5%) for the cleavage rate and in 7 batches (17.5%) for blastocyst rate. Overall, bull and frozen semen batch were the greatest sources of variation in the cleavage rate (30.6 and 29.4%, respectively), while testing date was the greatest source of variation in the blastocyst development rate (21.7%). The results indicated that in vitro fertilization and, to a lesser extent, culture to the blastocyst stage could be useful in estimating the potential fertilizing ability of frozen-thawed semen from dairy bulls.