Length of time of embryo storage does not negatively influence pregnancy rates after thawing and transfer

PURPOSE

To determine if longer storage of embryos in a cryopreserved state negatively affects the chance of successful implantation following thawing and transfer.

METHODS

A retrospective cohort analysis of frozen-thawed embryos that had been donated to recipients. Four time periods were evaluated.

RESULTS

No significant decrease in pregnancy or implantation rates was found in the longest freezing group (> or =6 years). In fact, if there was a trend, it was for improved pregnancy rates with longer storage. One of the successes was from embryos stored about 12 years.

CONCLUSIONS

Hopefully these data and results from other IVF centers will influence those countries having a mandatory discarding policy to reconsider and lift these restrictions, especially to increase the pool of embryos available for donation.

Cryopreservation of blastocysts using a modification of a simplified freezing protocol with a one step removal of cryoprotectant successfully used previously to freeze 2 pronuclear or multi-cell embryos

PURPOSE

To describe a modification of a simplified freezing protocol for the cryopreservation of blastocysts.

METHODS

1.5 M glycerol was substituted as a cryoprotectant instead of propanediol.

RESULTS

There was a survival rate of 59.1% (13/22) with three live deliveries in seven transfers (42.9% per transfer). The implantation rate was 28.6% (4/14).

CONCLUSIONS

This is the first description of a new technique for freezing blastocysts. A larger series is needed to determine if the good pregnancy rates will continue.

REP-PCR tracking of the origin and spread of airborne Staphylococcus aureus in and around chicken house

Staphylococcus aureus was used as an indicator to study the origin and spread of microbial aerosol in and around chicken houses. Air samples indoor, upwind (10 and 50 m), and downwind (10, 50, 100, 200, and 400 m) of four chicken houses were collected using Andersen-6 stages sampler. The concentrations of S. aureus were determined for every sample site. Isolation of S. aureus from chicken feces was performed according to the standard method. The genetic relationship among the isolates was determined by profiles of PCR-amplified repetitive extragenic palindromic (REP-PCR) elements. The results showed that the concentrations of S. aureus indoor of four chicken houses were higher than those upwind and downwind sites (P < 0.05 or P < 0.01), but there were no significant concentration differences among downwind sites (P > 0.05). The fingerprints and the phylogenetic tree indicated that a part of the S. aureus (55.6%, 10/18) isolates from indoor air had the same REP-PCR fingerprints as feces isolates. Consequently, most isolates (57.1%, 20/35) from downwind 10, 50, 100, 200, even 400 m had the same REP-PCR fingerprints as those from indoor or feces. These data indicated that some isolates from downwind and indoor originated from the chicken feces. However, those isolates from upwind had low similarity (similarity index 0.6-0.87) to those from indoor or feces. Therefore, the isolates upwind were not from the chicken feces or indoor. These results suggest that microbes in chicken feces can be aerosolized and spread indoor and outdoor, especially to downwind of the chicken houses. It should have an important epidemiological and public health significance.

PRACTICAL IMPLICATIONS

Thus, the use of S. aureus as an indicator to study the origin and spread of airborne pathogens from chicken houses is potentially useful for enhancing public health and understanding the airborne epidemiology of this pathogen. Meanwhile it can provide evidence for studying the spreading model of airborne pathogens.

Anisotropic diffusion properties in infants with hydrocephalus: a diffusion tensor imaging study

BACKGROUND AND PURPOSE

Diffusion tensor imaging (DTI) can noninvasively detect in vivo white matter (WM) abnormalities on the basis of anisotropic diffusion properties. We analyzed DTI data retrospectively to quantify the abnormalities in different WM regions in children with hydrocephalus during early infancy.

MATERIALS AND METHODS

Seventeen infants diagnosed with hydrocephalus (age range, 0.13-16.14 months) were evaluated with DTI and compared with 17 closely age-matched healthy children (age range, 0.20-16.11 months). Fractional anisotropy (FA), mean diffusivity (MD), axial diffusivity, and radial diffusivity values in 5 regions of interest (ROIs) in the corpus callosum and internal capsule were measured and compared. The correlation between FA and age was also studied and compared by ROI between the 2 study groups.

RESULTS

Infants with hydrocephalus had significantly lower FA, higher MD, and higher radial diffusivity values for all 3 ROIs in the corpus callosum, but not for the 2 ROIs in the internal capsule. In infants with hydrocephalus, the increase of FA with age during normal development was absent in the corpus callosum but was still preserved in the internal capsule. There was also a significant difference in the frequency of occurrence of abnormal FA values in the corpus callosum and internal capsule.

CONCLUSIONS

This retrospective DTI study demonstrated significant WM abnormalities in infants with hydrocephalus in both the corpus callosum and internal capsule. The results also showed evidence that the impact of hydrocephalus on WM was different in the corpus callosum and internal capsule.

Rap1b is critical for glycoprotein VI-mediated but not ADP receptor-mediated alpha2beta1 activation

BACKGROUND

The platelet alpha2beta1 integrin functions as both an adhesion and signaling receptor upon exposure to collagen. Recent studies have indicated that alpha2beta1 function can be activated via inside-out signaling, similar to the prototypical platelet integrin alphaIIbbeta3. However, signaling molecules that regulate alpha2beta1 activation in platelets are not well defined. A strong candidate molecule is the small GTPase Rap1b, the dominant platelet isoform of Rap1, which regulates alphaIIbbeta3 activation.

OBJECTIVES

We hypothesized that Rap1b positively regulates alpha2beta1 during agonist-induced platelet activation.

METHODS

To test whether Rap1b activates alpha2beta1 downstream of glycoprotein (GP)VI or other platelet receptors, we stimulated platelets purified from Rap1b-/- or wild-type mice with diverse agonists and measured alpha2beta1 activation using fluorescein isothiocyanate-labeled monomeric collagen. We also examined the role of Rap1b in outside-in signaling pathways by analyzing adhesion and spreading of Rap1b-/- or wild-type platelets on monomeric, immobilized collagen. Finally, we monitored the activation status of related Rap GTPases to detect changes in signaling pathways potentially associated with Rap1b-mediated events.

RESULTS

Rap1b-/- platelets displayed comparable ADP-induced or thrombin-induced alpha2beta1 activation as wild-type platelets, but reduced convulxin-dependent alpha2beta1 activation. Rap1b-/- platelets exhibited increased spreading on immobilized collagen but similar adhesion to immobilized collagen compared to wild-type platelets. Rap1b-/- platelets also showed Rap1a and Rap2 activation upon agonist stimulation, possibly revealing functional compensation among Rap family members.

CONCLUSIONS

Rap1b is required for maximal GPVI-induced but not ADP-induced activation of alpha2beta1 in murine platelets.

Polymorphisms in the interleukin 3 gene show strong association with susceptibility to Graves' disease in Chinese population

Graves' disease (GD) is a common organ-specific autoimmune disorder, which is multifactorial and develops in genetically susceptible individuals. We had earlier mapped a susceptibility locus for GD to chromosome 5q31-33 in a linkage study. Here we used tag single-nucleotide polymorphisms (SNPs) to search for genetic variants associated with GD, and examined 19 functional candidate genes in this chromosomal region. We identified 192 polymorphisms by re-sequencing the candidate genes, and selected 51 tagSNPs to genotype in a case-control collection of 1118 south Han Chinese subjects (428 cases and 690 controls). Initial analysis suggested that a non-synonymous SNP rs40401 (P27S) of interleukin 3 (IL3) was associated with GD, and further fine-mapping showed that rs40401, or its perfect proxy SNP rs31480 in the 5' flanking region of IL3, fully accounted for the association signal at this locus. We replicated significant association of rs40401 with GD in an independent sample collection of 839 north Han Chinese subjects. A combined analysis revealed strong validation of this association (odds ratio (OR(common))=1.63, combined P (P(comb))=4 x 10(-6) in the Recessive disease model). This study provides convincing evidence that the IL3 gene is a susceptibility locus for GD in the Chinese population.

Effect of the degree of fragmentation on embryo survival after freeze-thawing

PURPOSE

To determine if the degree of fragmentation of embryos prior to freezing correlate in a negative manner with survival after thawing.

METHODS

A retrospective review of frozen embryos thawed for purposes of embryo transfer was done. Survival and transferability rates were determined according to degree of fragmentation.

RESULTS

The chance that an embryo with < 25% fragmentation was deemed good enough for transfer upon thawing was 63.6% compared to 52.8% for embryos > 25% (p < .05).

CONCLUSIONS

Though more fragmented embryos have a lower survival rate after freeze thawing, about 50% of embryos with > 25% fragmentation will still survive the thaw and be able to be transferred.

Comparison of the efficacy of selecting sperm with normal nuclei by high magnification for intracytoplasmic sperm injection (ICSI) according to age in refractory in vitro fertilization (IVF) cases

PURPOSE

To determine the pregnancy rates according to age in women failing to conceive after three previous embryo transfers or having a husband whose sperm shows a DNA fragmentation index (DFI) > 30% when performing the sperm chromatin structure assay.

METHODS

Women up to age 45 were included and there was no restriction for low egg reserve. Live delivered pregnancy rates were determined according to three age groups: < or =34, 35-38, 39-45. The data were also analyzed in a group comparable to previous publications using high magnification ICSI, i.e., younger women with normal egg reserve. Pregnancy rates following frozen embryo transfer were also evaluated.

RESULTS

Using all 86 in vitro fertilization-embryo transfer (IVF-ET) cycles the live delivered pregnancy rates were 40% (10/25) for women < or = age 34, 24% (6/25) in women age 35-38, and 13.8% in women aged 39-45. Evaluating the younger group with normal egg reserve with > or =3 previous failed IVF-ET cycles the live delivered pregnancy rate per transfer was 38% (16/42). If one adds the additional six live deliveries from subsequent frozen embryo transfer (6 of 17, 35.3%) this group of women had a 52.3% (22/42) live delivered pregnancy rate from one egg retrieval.

CONCLUSIONS

These data were uncontrolled and thus conclusions should be viewed with caution. The results are sufficiently encouraging to warrant a prospective controlled trial and possibly encourage a company to consider commercially manufacturing high magnification microscopes.

A comparison of efficacy of freezing embryos at the 2 pronuclear (2PN) stage vs multi-cell when using a simplified freezing protocol with one-step removal of cryoprotectant

PURPOSE

To compare the efficacy of freezing embryos at the 2 pronuclear stage vs multi-cell stage using a simplified freezing protocol with a one-step removal of the cryoprotectant.

METHODS

A retrospective analysis was performed. Survival, delivered pregnancy and implantation rates were compared in transfers of all embryos frozen at 2 pronuclear stage (2PN) or all embryos frozen at multi-cell stage. The results were further stratified and compared according to the number of high quality embryos transferred.

RESULTS

In all categories despite comparing similar numbers and quality of embryos transferred there was a significantly higher survival rate of 2PN embryos. Significantly higher delivered pregnancy and implantation rates were seen with 2PN vs multi-cell embryos when there was only one or two embryos with > or = 6 blastomeres and < 25% fragmentation, and a trend for higher delivered pregnancy rates when there were three top quality embryos transferred.

CONCLUSIONS

When given the option it is preferable when using this simplified freezing and thawing protocol to freeze at the 2PN stage.

Pregnancy rates per embryo transfer (ET) may be improved by conventional oocyte insemination for male factor rather than intracytoplasmic sperm injection (ICSI)

PURPOSE

To determine if intracytoplasmic sperm injection (ICSI) for mild male factor may create embryos less likely to implant.

METHOD

A retrospective analysis of pregnancy outcome following oocyte fertilization with ICSI vs conventional egg insemination was performed.

RESULTS

Though there were many less cases using conventional oocyte insemination compared to ICSI so that a meaningful comparison of outcome could not be made, the data could suggest the fertilization by ICSI might result in embryos less likely to implant.

CONCLUSIONS

This pilot study should encourage IVF centers to consider conventional oocyte insemination for mild male factor instead of ICSI. Only by evaluating a larger series can it be determined with certainty that fertilization by ICSI may lower the implantation potential of the embryo that is formed.

The effect of blastomere number on embryo survival upon freezing/thawing

PURPOSE

To determine if the blastomere number of embryos at the time of freezing is related to its quality post-thaw.

METHODS

A retrospective cohort analysis of frozen/thawed embryos. Only multi-cell embryos were used for this study. If an embryo was of good quality it would either be transferred or re-frozen.

RESULTS

There did not appear to be any trend for a lower percentage of good quality embryos with fewer numbers of blastomeres.

CONCLUSIONS

Though 4-cell embryos have a markedly lower implantation potential upon fresh embryo transfer compared to 6-8-cell embryos, this is not reflected in their ability to survive freeze-thawing.

Comparison of SNR and CNR for in vivo mouse brain imaging at 3 and 7 T using well matched scanner configurations

Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) for magnetic resonance microimaging were measured using two nearly identical magnetic resonance imaging (MRI) scanners operating at field strengths of 3 and 7 T. Six mice were scanned using two imaging protocols commonly applied for in vivo imaging of small animal brain: RARE and FLASH. An accounting was made of the field dependence of relaxation times as well as a small number of hardware disparities between scanner systems. Standard methods for relaxometry were utilized to measure T1 and T2 for two white matter (WM) and two gray matter (GM) regions in the mouse brain. An average increase in T1 between 3 and 7 T of 28% was observed in the brain. T2 was found to decrease by 27% at 7 T in agreement with theoretical models. The SNR was found to be uniform throughout the mouse brain, increasing at higher field by a factor statistically indistinguishable from the ratio of Larmor frequencies when imaging with either method. The CNR between GM and WM structures was found to adhere to the expected field dependence for the RARE imaging sequence. Improvement in the CNR for the FLASH imaging sequence between 3 and 7 T was observed to be greater than the Larmor ratio, reflecting a greater susceptibility to partial volume effects at the lower SNR values at 3 T. Imaging at 7 T versus 3 T in small animals clearly provides advantages with respect to the CNR, even beyond the Larmor ratio, especially in lower SNR regimes. This careful multifaceted assessment of the benefits of higher static field is instructive for those newly embarking on small animal imaging. Currently the number of 7 T MRI scanners in use for research in human subjects is increasing at a rapid pace with approximately 30 systems deployed worldwide in 2008. The data presented in this article verify that if system performance and radio frequency uniformity is optimized at 7 T, it should be possible to realize the expected improvements in the CNR and SNR compared with MRI at 3 T.

Chinese herbal medicine Huangqi type formulations for nephrotic syndrome

BACKGROUND

At present, there is a lack of safe and effective drugs for nephrotic syndrome (NS). Huangqi type formulations have been used to treat nephrotic syndrome for years in China, however the effects and safety of these formulations have not been systematically reviewed.

OBJECTIVES

To assess the benefits and harms of Huangqi and Huangqi type formulations in treating NS in any age group, either as sole agents or in addition to other drug therapies.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, Chinese Biomedicine Database (CBM), CNKI, VIP and reference lists of articles. There was no language restriction. Date of most recent search: June 2006.

SELECTION CRITERIA

All randomised controlled trials (RCTs) assessing the use of Huangqi or Huangqi type formulations in treating NS in adults and children, either as sole agents or in addition to other drug therapies.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed study quality and extracted data. For dichotomous outcomes (remission, side effects and Inefficacy rate), results were expressed as relative risk (RR) and 95% confidence intervals (CI). Continuous outcomes (triglycerides cholesterol, plasma albumin) results were expressed as mean difference (WMD) with 95% CI.

MAIN RESULTS

Three studies were identified (n = 128), all comparing Huangqi type formulations with placebo. Huangqi injection had a positive effect on plasma albumin (WMD 6.90, 95% Cl 3.60 to 10.20) and cholesterol (WMD 2.13, 95% Cl -2.97 to -1.29). Huangqi and red Chinese date reduced some adverse reactions (Cushing's syndrome: RR 0.55, 95% Cl 0.32 to 0.94; hormone reduced syndrome: RR 0.58, 95% Cl 0.39 to 0.85, respiratory tract infection: RR 0.27, 95% Cl 0.08 to 0.88), but no benefit on reducing relapse. Huangqi and Danggui had a positive effect on cholesterol (WMD -0.85, 95% Cl -1.70 to 0.00).

AUTHORS' CONCLUSIONS

Huangqi type formulations may have some positive effects in treating NS by increasing plasma albumin and reducing blood cholesterol, Cushing's syndrome, hormone reduced syndrome and respiratory tract infection. However, limited by the lack of high quality clinical studies, we are unable to recommend Huangqi type formulations for NS. Large, properly randomised, placebo-controlled, double-blind studies are required.

Vitamin A for preventing acute lower respiratory tract infections in children up to seven years of age

BACKGROUND

Vitamin A supplements are effective for preventing diarrhoea. There are theoretical reasons it might also be effective for acute lower respiratory tract infections (LRTIs), also very common in children, especially in low income countries.

OBJECTIVES

To assess the effectiveness and safety of vitamin A for preventing acute LRTIs in children up to seven years of age.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 2); MEDLINE (1966 to July 2007); EMBASE (1974 to July 2007); and the Chinese Biomedicine Database (CBM) (1976 to July 2007).

SELECTION CRITERIA

Randomised controlled trials (RCTs) that assessed the effectiveness of vitamin A in the prevention of acute LRTI in children up to seven years of age.

DATA COLLECTION AND ANALYSIS

The review authors independently extracted data and assessed trial quality. Study authors were contacted for additional information.

MAIN RESULTS

Most studies found no significant effect of vitamin A on the incidence of acute LRTI, or prevalence of symptoms of acute LRTI. Vitamin A caused an increased incidence of acute LRTI in one study; an increase in cough and fever; and increased symptoms of cough and rapid breathing in two others. Three reported no differences and no protective effect of vitamin A. Two studies reported that vitamin A significantly reduced the incidence of acute LRTI with children with poor nutritional status or weight, but increased it in normal children.

AUTHORS' CONCLUSIONS

This unexpected result is outside our current understanding of the use of vitamin A for preventing acute LRTIs. Accordingly, vitamin A should not be given to all children to prevent acute LRTIs. There is evidence for vitamin A supplements to prevent acute LRTIs in children with low serum retinol or those with a poor nutritional status.

Improving the sensitivity limit of surface plasmon resonance biosensors by detecting mixed interference signals

We demonstrate that the sensitivity limit of intensity-based surface plasmon resonance (SPR) biosensors can be enhanced when we combine the effects of the phase and amplitude contributions instead of detecting the amplitude variation only. Experimental results indicate that an enhancement factor of as much as 20 times is achievable, yet with no compromise in measurement dynamic range. While existing SPR biosensor systems are predominantly based on the angular scheme, which relies on detecting intensity variations associated with amplitude changes only, the proposed scheme may serve as a direct system upgrade approach for these systems. The new measurement scheme may therefore lead to a strong impact in the design of SPR biosensors.