[Radiographic assessment of vertebral artery injury in anterior cervical surgery in healthy adults]

Objectives: To study the relationship between the anatomical parameters of transverse foramen and intervertebral discs in the cross-section of the cervical spine in healthy adults, and to evaluate the risk of vertebral artery injury in the anterior cervical spine surgery. Methods: There were 24 healthy adults(12 male, 12 female) underwent neck CT angiography with clear vertebral artery and the adjacent structure imaging from June to December 2014 in Huashan Hospital, Fudan University. The anatomical parameters of vertebral artery V2 segment with lower cervical vertebrae and intervertebral discs were measured by cross-sectional images of C(3-6). The corresponding parameters of different sex and both sides of the same segment were analyzed by independent samples t-test and paired t test, respectively. The least significant difference(LSD) t test was used to compare the corresponding data between different segments. Results: The vertebral artery was not walking in the middle of the transverse foramen in healthy individual, but partial medial, partial front walking. Transverse diameter of transverse foramen in male and female were 6.62-6.89 mm and 6.21-6.45 mm, and sagittal diameter was 5.41-6.48 mm and 5.40-6.10 mm, respectively.The transverse foramen were slightly oval. The distance between vertebral artery and midline in male and female were 14.23-16.12 mm and 13.60-15.04 mm, respectively, which was much larger than the width of cervical vertebral corpectomy. Compared with C(3-4), intervertebral disc, the transverse distance between the vertebral artery and the uncovertebral joint of C(4-5), C(5-6) was smaller, and the distance from the vertebral artery to the posterior margin of the uncovertebral joint was relatively small, the difference was statistically significant (t=2.449, P=0.022). The distance from vertebral artery to the posterior margin of uncinate process was 1/5-2/5 of the distance between the anterior and posterior edge of the corresponding segmental vertebra. Conclusion: Based on this anatomical study, the risk of vertebral artery injury in conventional anterior cervical decompression is small, and the risk of vertebral artery injury in different segments is slightly different.

Cloning and transcriptional expression of a novel gene during sex inversion of the rice field eel (Monopterus albus)

We performed annealing control primer (ACP)-based differential-display reverse transcription-polymerase chain reaction (DDRT-PCR) to isolate differentially expressed genes (DEGs) from the stage IV ovary and ovotestis of the rice field eel, Monopterus albus. Using 20 arbitrary ACP primers, 14 DEG expressed-sequence tags were identified and sequenced. The transcriptional expression of one DEG, G2, was significantly greater in the ovotestis than the stage IV ovary. To understand the role of G2 in sex inversion, G2 cDNA was cloned and semi-RT-PCR, real time PCR were performed during gonad development. The full-length G2 cDNA was 650 base pairs (bp) and it comprised a 5′-untranslated region (UTR) of 82 bp, a 3′-UTR of 121 bp and an open reading frame of 444 bp that encoded a 148-amino acid protein. The expression of G2 was weak during early ovarian development until the stage IV ovary, but expression increased significantly with gonad development. We speculate that G2 may play an important function during sex inversion and testis development in the rice field eel, but the full details of the function of this gene requires further research.

Modal analysis and efficient coupling of TE₀₁ mode in small-core THz Bragg fibers

We report a design of low-loss THz Bragg fibers with a core size on the order of wavelength that operates near the cutoff frequency of its TE01 mode. We also propose a broadband Y-type mode converter based on branched rectangular metallic waveguides to facilitate coupling between the TE01 mode of the Bragg fiber and the TEM mode in free space with 60% efficiency. Our fiber holds strong promise to facilitate beam-wave interaction in gyrotron for high-efficiency THz generation.

Effect of Water Invasion on Outburst Predictive Index of Low Rank Coals in Dalong Mine

To improve the coal permeability and outburst prevention, coal seam water injection and a series of outburst prevention measures were tested in outburst coal mines. These methods have become important technologies used for coal and gas outburst prevention and control by increasing the external moisture of coal or decreasing the stress of coal seam and changing the coal pore structure and gas desorption speed. In addition, techniques have had a significant impact on the gas extraction and outburst prevention indicators of coal seams. Globally, low rank coals reservoirs account for nearly half of hidden coal reserves and the most obvious feature of low rank coal is the high natural moisture content. Moisture will restrain the gas desorption and will affect the gas extraction and accuracy of the outburst prediction of coals. To study the influence of injected water on methane desorption dynamic characteristics and the outburst predictive index of coal, coal samples were collected from the Dalong Mine. The methane adsorption/desorption test was conducted on coal samples under conditions of different injected water contents. Selective analysis assessed the variations of the gas desorption quantities and the outburst prediction index (coal cutting desorption index). Adsorption tests indicated that the Langmuir volume of the Dalong coal sample is ~40.26 m³/t, indicating a strong gas adsorption ability. With the increase of injected water content, the gas desorption amount of the coal samples decreased under the same pressure and temperature. Higher moisture content lowered the accumulation desorption quantity after 120 minutes. The gas desorption volumes and moisture content conformed to a logarithmic relationship. After moisture correction, we obtained the long-flame coal outburst prediction (cutting desorption) index critical value. This value can provide a theoretical basis for outburst prediction and prevention of low rank coal mines and similar occurrence conditions of coal seams.

The role of necroptosis in neurosurgical diseases

Programmed necrosis or necroptosis is an alternative form of cell death that is executed through a caspase-independent pathway. Necroptosis has been implicated in many pathological conditions. Genetic or pharmacological inhibition of necroptotic signaling has been shown to confer neuroprotection after traumatic and ischemic brain injury. Therefore, the necroptotic pathway represents a potential target for neurological diseases that are managed by neurosurgeons. In this review, we summarize recent advances in the understanding of necroptotic signaling pathways and explore the role of necroptotic cell death in craniocerebral trauma, brain tumors, and cerebrovascular diseases.

Antitussive, expectorant and bronchodilating effects of ethanol extract of Sorghum bicolor (L.) Moench roots

ETHNOPHARMACOLOGICAL RELEVANCE

Root of Sorghum bicolor (L.) Moench (RSB) is an herbal medicine in Traditional Chinese Medicine, still used in some rural areas in Central China as an alternative remedy to treat cough and asthma.

AIM OF THE STUDY

The study was aimed at evaluating the antitussive, expectorant and bronchodilating effects of ethanol extract of RSB, support its folk use with scientific evidence, and lay a foundation for its further researches.

MATERIALS AND METHODS

RSB was extracted with 80% ethanol aqueous in reflux conditions, solutions were concentrated in reduced pressure, and lyophilized in vacuum to yield the RSB extract. Antitussive evaluations were carried out with three different models including ammonia liquor induced mice cough, capsaicin induced mice cough, and citric acid induced guinea pigs cough; phenol red secretion experiments in mice were performed to evaluate the expectorant ability; bronchodilating effects were evaluated with a bronchoconstrictive challenge induced by acetylcholine chloride and histamine in guinea pigs.

RESULTS

In all the three antitussive tests, treatment of RSB significantly inhibited the frequency of cough, and prolonged the cough latent period in animals. And high dose of RSB (200mg/kg in mice and 100mg/kg in guinea pigs) created therapeutic activities as good as standard antitussive drug codeine phosphate (20mg/kg). In the expectorant evaluation, 50, 100 and 200mg/kg RSB treatment had significantly increased the amount of phenol red output for 0.39, 1.18, and 1.96 folds in mice tracheas. In the bronchodilating test, RSB treatment at 100mg/kg extended the preconvulsive time for 44.84% compared with that of before treatment in guinea pigs.

CONCLUSIONS

RSB is an effective alternative medicine for the treatment of cough with potent antitussive, expectorant and bronchodilating activities.

Gene expression analysis of ruptured and un-ruptured saccular intracranial aneurysm

BACKGROUND

Although Saccular intracranial aneurysm (sIA) is the most common type abnormality of all intracranial aneurysms, the biological mechanisms of sIA are not fully understood.

METHODS

We downloaded microarray datasets from Gene Expression Omnibus (GEO) database which includes 11 ruptured intracranial aneurysm samples and 8 unruptured intracranial aneurysm samples. Significant Analysis of Microarray (SAM) was employed to identify the differentially expressed genes (DEGs) between ruptured and unruptured intracranial aneurysms.

RESULTS

We found 2129 genes differentially expressed in rupture sIA, of which 1062 genes up-regulated and 1057 genes down-regulated. Functional analysis demonstrated these genes were significantly associated with inflammatory response, wounding response and defense response. Protein-protein interaction (PPI) analysis revealed that these genes may play important roles in the pathogenesis of sIAs. Results suggested that four transcription factors (TFs) could cooperated with each other, together with several microRNAs play roles in the pathonegensis of ruptured sIAs.

CONCLUSIONS

All of above results indicate the existence of DEGs between ruptured and unruptured sIAs, which regulating the pathogenesis of ruptured sIAs. TFs and microRNAs may also play key roles in ruptured sIAs. This research hints a new thought to the therapy of ruptured sIAs.

[FTY720 attenuates rat anti-Thy-1 mesangial proliferative glomerulonephritis by inhibition of transforming growth factor β1-connective tissue growth factor pathway]

OBJECTIVE

To investigate whether FTY720 inhibits rat mesangial proliferation and extracellular matrix expansion through suppression of transforming growth factor β1-connective tissue growth factor (TGFβ1-CTGF) pathway, and to explore experimental evidence for its effect on mesangial proliferative glomerulonephritis.

METHODS

A rat model of anti-Thy-1 mesangial proliferative glomerulonephritis was established and FTY720 intervention was performed. Periphery blood lymphocyte count, urine protein excretion, glomerular mesangial proliferation, protein and gene expression of TGFβ1 and CTGF and extracellular matrix protein including fibronectin, laminin and collagen IV in isolated glomeruli were documented at 1, 3 and 7 days after injection of anti-Thy-1 antibody.

RESULTS

The model group developed proteinuria at 1, 3 and 7 days after injection of anti-Thy-1 antibody, which were significantly higher [(27.9 ± 7.3), (63.5 ± 18.8) and (52.4 ± 15.4)mg/d, respectively] than those in the control group [(8.4 ± 2.4), (8.4 ± 2.1) and (10.4 ± 3.2) mg/d; respectively, P < 0.01]. FTY720 intervention group showed significantly decreased proteinuria at 3 and 7 days after injection [(31.4 ± 7.0), (25.5 ± 7.7) mg/d, respectively] than model group (P < 0.01), although higher than the control group (P < 0.01). After intervention for 3 and 7 days, FTY720 significantly down-regulated both TGFβ1 and CTGF gene and protein expression in cultured glomeruli, and suppressed the production of glomerular extracellular matrix protein secretion, leading to attenuated mesangial cell proliferation and extracellular matrix expansion in rat anti-Thy-1 mesangial proliferative glomerulonephritis.

CONCLUSION

FTY720 significantly attenuates mesangial proliferation and extracellular matrix expansion through inhibition of TGFβ1-CTGF pathway in rat, and thus ameliorates the development of anti-Thy-1 mesangial proliferative glomerulonephritis.

Development of a cell immobilization technique for the conversion of polysialogangliosides to monosialotetrahexosylganglioside

CONTEXT

Monosialotetrahexosylganglioside (GM₁) prepared from the brain of pig or bovine is an effective clinical drug in the treatment of different nervous system diseases. Generally, polysialogangliosides are transformed into GM₁ by enzymic or chemical hydrolysis due to the very poor level of natural GM₁.

OBJECTIVE

To continuously obtain GM₁ by cell immobilization in a packed-bed reactor.

MATERIALS AND METHODS

Brevibacterium casei, which is Gram-positive bacteria belonging to the order Actinomyces and family Brevibacteriaceae, can produce high-activity sialidase, are encapsulated in silk fibroin hydrogel, and subsequently packed into a reactor. The crude ganglioside is pumped into the reactor and continuously turned to GM₁.

RESULTS

The optimal silk fibroin concentration for hydrogel preparation is 6.0% (w/v). The optimal initial biomass for immobilization is ~12% (wet weight). The optimal conversion conditions are 35 °C and 6  mL/min of flow rate. Under above conditions, the maximum GM₁ productive strength and conversion ratio can reach to 4.2 g/L·h and 313.5%, respectively.

DISCUSSION

Silk fibroin is a promising material for cell immobilization because it has predominant characteristics of higher permeability and intensity. Cell immobilization for continuous GM₁ transformation could eliminate the asialo GM₁ and decrease the foreign matter from transfer medium and metabolism product.

CONCLUSION

In the packed-bed reactor, continuous production of GM₁ had been under effective running at least for 15 days indicating a potential for industrial production. It is significant that this is a first report on cell immobilization for GM₁ production.

Adherence to lipid-lowering agents among 11,042 patients in clinical practice

AIMS

Dyslipidaemia is a poorly-controlled condition in clinical practice largely because of poor adherence to medication regimens by patients. This study evaluated the levels of and factors associated with adherence to lipid-lowering agents in a large Chinese population.

METHODS

From a validated clinical database, we included all patients who attended any public, primary care clinics in one large Territory of Hong Kong for medication refill at least twice during the study period January 2004 to June 2007. The major outcome variable was Medication Possession Ratio (MPR), an internationally-recognised metric to measure drug adherence. The factors associated with optimal drug adherence (MPR ≥ 0.8) were evaluated by multivariate regression analysis.

RESULTS

From 11,042 eligible patients, 90% were adherent. After adjusting for patients' age, gender, socioeconomic status, service type, district of residence, visit type (new visits vs. follow-up visits), the number of comorbidities and the drug class (statin vs. fibrates), older patients [aged 50-59 years; adjusted odds ratio (AOR) 1.30, p = 0.009; 60-69 years; AOR 1.53, p < 0.001; ≥ 70 years; AOR 1.72, p < 0.001], attendance in family medicine specialist clinics (FMSC; AOR 1.56, p < 0.001), follow-up visits (AOR 2.93, p < 0.001) and the presence of comorbidities (one comorbidity; AOR 1.45, p < 0.001; ≥ 2 comorbidities; AOR 1.56, p < 0.001) were associated with optimal drug adherence.

DISCUSSION AND CONCLUSION

These findings carry an implication that younger subjects, new patients, visitors in clinics other than FMSC and those without comorbidities should receive more meticulous monitoring of their medication-taking behaviour. Future studies should evaluate the major reasons for non-adherence among them.

Multiple primary primitive neuroectodermal tumours within the spinal epidural space with non-concurrent onset

A case of multiple primary primitive neuroectodermal tumours (PNETs), which occurred at different levels of the spinal epidural space successively over a period of 8 months, is reported. A 24-year-old male, presenting with rapidly progressive paralysis, hyperthesia and a posterior epidural mass extending from T8 to T10 revealed by magnetic resonance imaging (MRI), exhibited a good recovery after initial emergency surgery. Lower back pain, chest pain and paralysis were subsequently reported. Spinal MRI in month 7 revealed a mass extending from T12 to L1 and another mass extending from T4 to T5 was detected epidurally in month 8. Additional operations were performed and radiotherapy was given. Pathological findings were consistent with PNETs and symptoms improved with treatment, particularly following each surgical excision.

High-speed, high-resolution optical coherence tomography retinal imaging with a frequency-swept laser at 850 nm

High-speed, high-resolution optical coherence tomography (OCT) imaging of the human retina is demonstrated using a frequency-swept laser at 850 nm. A compact external cavity semiconductor laser design, optimized for swept-source ophthalmic OCT, is described. The laser enables an effective 16 kHz sweep rate with >10 mm coherence length and a tuning range of approximately 35 nm full width at half-maximum, yielding an axial resolution of <7 micro m in tissue.

Prognostic factors of anaplastic thyroid carcinoma

BACKGROUND AND PURPOSE

Anaplastic thyroid carcinoma (ATC) is one of the most aggressive malignancies. We tried to elucidate the possible prognostic factors.

METHODS

A retrospective review was conducted of ATC patients in National Taiwan University Hospital from 1978 to 2003. Their demographic characteristics, clinical presentations, laboratory data and treatment modalities were reviewed. Possible prognostic factors for survival were evaluated.

RESULTS

Forty-five patients (14 males and 31 females) of mean age 61.9 +/- 12.6 yr were included in this study. The median survival time was 94 days (range 6 to 776 days). The overall survival rate was 27% at 6 months and 10% at 1 yr. Thirty-two patients receiving intervention regimens had a median survival of 106 days, while 13 patients receiving palliative therapy had a median survival of 39 days. The difference in survival is statistically significant (logrank test, p = 0.017). Adjusted with sex and age, increment in white blood cell count (per 10(9)/l) and serum albumin (per 1.0 g/l) had a hazard ratio of 1.12 (Cox regression, p < 0.001) and 0.92 (p = 0.041), respectively. Patients with leukocytosis [white blood cell (WBC) count > 10(10)/l] or hypoalbuminemia (serum albumin < 35 g/l) had significant shorter survival than patients without leukocytosis or hypoalbuminemia (logrank test p = 0.008 and p = 0.032, respectively). Patients with serum T4 levels lower than 64.35 nmol/l had significantly shorter survival than patients without hypothyroxinemia (median survival 24 vs 128 days, logrank test, p = 0.004).

CONCLUSIONS

ATC is an aggressive malignancy. Leukocytosis, hypoalbuminemia and hypothyroxinemia indicated poor prognosis. Survival time might be prolonged if intervention treatment is tolerable.

Three-dimensional and C-mode OCT imaging with a compact, frequency swept laser source at 1300 nm

We demonstrate high resolution, three-dimensional OCT imaging with a high speed, frequency swept 1300 nm laser source. A new external cavity semiconductor laser design, optimized for application to swept source OCT, is discussed. The design of the laser enables adjustment of an internal spectral filter to change the filter bandwidth and provides a robust bulk optics design. The laser generates ~30 mW instantaneous peak power at an effective 16 kHz sweep rate with a tuning range of ~133 nm full width. In frequency domain reflectometry and OCT applications, 109 dB sensitivity and ~10 microm axial resolution in tissue can be achieved with the swept laser. The high imaging speeds enable three-dimensional OCT imaging, including zone focusing or C-mode imaging and image fusion to acquire large depth of field data sets with high resolution. In addition, three-dimensional OCT data provides coherence gated en face images similar to optical coherence microscopy (OCM) and also enables the generation of images similar to confocal microscopy by summing signals in the axial direction. High speed, three-dimensional OCT imaging can provide comprehensive data which combines the advantages of optical coherence tomography and microscopy in a single system.

Capillary angiogenesis and degeneration in bovine ovarian antral follicles

Angiogenesis and capillary degeneration are both evident during ovarian follicle growth. However, the characteristics and distribution of thecal capillary proliferative and degenerative structures have not been fully defined. Indeed, the role of thecal microvasculature changes in follicular atresia is still a matter of debate. The present study examined the distribution of thecal capillary changes occurring during follicular growth and related the changes to capillary morphology (by scanning electron microscopy, SEM, on bovine ovarian corrosion casts) with the incidence of capillary apoptosis (TdT-mediated dUTP nick end-labelling, TUNEL) and follicular status (as confirmed by follicular fluid steroid concentrations). SEM demonstrated well-perfused vascular plexuses of small to large antral follicles with structural and functional changes to capillaries. Angiogenesis was evident mainly in the apical part of the inner capillary layer of medium follicles and the middle or basal part of the inner capillary layer of dominant follicles that exhibited high oestradiol:progesterone ratios. Degenerative capillaries were observed mainly in the outer vascular layers of small follicles, and in the inner and outer vascular layers of medium antral follicles. Although apoptotic structures were present only in the outer capillaries of the theca interna of morphologically healthy antral follicles, atretic follicles showed apoptotic structures in both the outer and inner thecal capillary layers. These results show that angiogenesis increases during bovine follicular growth and occurs unevenly in different inner theca regions of the follicles. The differential angiogenic and degenerative response of theca interna capillaries may reflect differences in the microenvironment of the follicles, which in turn determine the fate of the follicles (continued growth versus atresia).

Capillary angiogenesis and degeneration in bovine ovarian antral follicles

Angiogenesis and capillary degeneration are both evident during ovarian follicle growth. However, the characteristics and distribution of thecal capillary proliferative and degenerative structures have not been fully defined. Indeed, the role of thecal microvasculature changes in follicular atresia is still a matter of debate. The present study examined the distribution of thecal capillary changes occurring during follicular growth and related the changes to capillary morphology (by scanning electron microscopy, SEM, on bovine ovarian corrosion casts) with the incidence of capillary apoptosis (TdT-mediated dUTP nick end-labelling, TUNEL) and follicular status (as confirmed by follicular fluid steroid concentrations). SEM demonstrated well-perfused vascular plexuses of small to large antral follicles with structural and functional changes to capillaries. Angiogenesis was evident mainly in the apical part of the inner capillary layer of medium follicles and the middle or basal part of the inner capillary layer of dominant follicles that exhibited high oestradiol:progesterone ratios. Degenerative capillaries were observed mainly in the outer vascular layers of small follicles, and in the inner and outer vascular layers of medium antral follicles. Although apoptotic structures were present only in the outer capillaries of the theca interna of morphologically healthy antral follicles, atretic follicles showed apoptotic structures in both the outer and inner thecal capillary layers. These results show that angiogenesis increases during bovine follicular growth and occurs unevenly in different inner theca regions of the follicles. The differential angiogenic and degenerative response of theca interna capillaries may reflect differences in the microenvironment of the follicles, which in turn determine the fate of the follicles (continued growth versus atresia).

Follicular microvasculature in the porcine ovary

The microvasculature of porcine ovaries, with special regard to the follicles in the interstitial-stromal tissue, was studied by scanning electron microscopy (SEM) of vascular corrosion casts. Porcine ovaries displayed several coiled arteries in the hilus and many branches with small diameters and a tightly spiraling configuration in the cortical areas. However, small arterioles became straight before entering vascular complexes of follicles and finally divided into capillaries. Vascular baskets of various sizes (150-9,900 micro m in diameter) and architecture related to follicles in various developmental stages were observed in the ovarian cortex. Small follicles (150-300 micro m in diameter) began with a polygonal meshwork of a few large capillary meshes and developed to an obvious spherical microvascular network with a thin single layer of capillaries when reaching 500-700 micro m in diameter. The microvascular architecture of follicles 1,000-2,000 micro m in diameter developed further and had a three-layer vascular plexus. With a diameter of more than 2,000 micro m, the microvasculature of antral follicles was arranged as an inner vascular plexus of about 25 micro m, a middle plexus of about 100 micro m, and an outer capillary plexus of about 30 micro m in thickness. The present observations indicate that follicular vascular baskets of diverse sizes and architecture in various developmental stages support the gradual increase of follicular blood flow during follicle growth in the pig.

Follicular development and ovulation in hypothyroid rdw rats

In this paper, we summarized our recent studies on follicular development and ovulation in the presence or absence of thyroxine (T4) and equine chorionic gonadotrophin (eCG) treatment in infertile immature spontaneously hypothyroid rdw rats. T4 therapy once daily from postnatal day 21 to day 29 resulted in increases in ovarian weight on day 30 (P 0.01). Similar populations of both healthy and atretic antral follicles ranging in diameter from 101-400 microm were observed in control rdw and normal rats. T4 treatment markedly increased the numbers of healthy antral follicles of 101-400 microm or larger than 550 microm in diameter in the absence or presence of eCG, respectively, in rdw rats. On the other hand, T4 treatment did not affect the population of atretic antral follicles, but decreased the number of atretic large antral follicles (>400 microm) in the presence of eCG. Although a few (5+/-2) eggs were obtained from immature rdw rats treated with gonadotrophins alone, significantly more eggs (85+/-5) were ovulated from females treated with gonadotrophins and T4. As a control, normal littermates ovulated 45 eggs when treated with gonadotrophins only and 68 eggs when to them were also given T4. In conclusion, the results of the present study indicated that T4 treatment improved follicular development in the presence of eCG and significantly increased the number of ovulated eggs following hCG treatment in rdw rats.

Characteristics of infertility in female hypothyroid (hyt) mice

Female hypothyroid (hyt) mice are infertile, but the reason for this infertility is not yet known. The present study was conducted to determine whether hypothyroidism induced infertility in immature and mature hyt mice. Furthermore, animals were treated with thyroxine and gonadotrophins at different times to determine whether infertility was due to failure of follicular development, implantation or pregnancy. There were no significant differences in the numbers of ovulated eggs induced by gonadotrophin treatment or the percentages of eggs developed in vitro among immature normal controls, hyt and thyroxine-treated hyt mice. Mature hyt mice showed continuous dioestrus, and ovulated significantly fewer eggs after gonadotrophin treatment and failed to establish pregnancy after mating compared with mature control mice. Mature hyt mice had significantly fewer corpora lutea > 500 microm in diameter and significantly lower progesterone concentrations. Thyroxine treatment before mating in hyt mice resulted in well-developed corpora lutea, an increase in progesterone and normal pregnancy, regardless of subsequent thyroxine administration. In conclusion, infertility occurs in mature rather than immature hyt mice, is due to the failure of follicular development and pregnancy, and can be reversed by thyroxine treatment before mating.

Vitrification of large quantities of immature bovine oocytes using nylon mesh

Vitrification of oocytes and embryos has recently been improved using new physical supports such as electron microscope (EM) grids, open-pulled straws, and cryoloops. However, the number of samples per container was restricted in each of these methods. In the present study, to develop a novel simple technique for vitrification of large quantities of oocytes or embryos, we examined vitrification of large quantities of immature bovine oocytes using nylon mesh as a novel container. As many as 65 oocyte-cumulus cell complexes could be placed on nylon mesh for vitrification compared with 15 per EM grid. Recovery rates were higher when using nylon mesh than EM grids, while fertilization and development rates were not different. These results indicated that vitrification using nylon mesh is useful and offers a new way to cryopreserve large numbers of oocytes.