Alginate encapsulation supports the growth and differentiation of human primordial follicles within ovarian cortical tissue

Purpose

In vitro follicle growth (IVFG) is an investigational fertility preservation technique in which immature follicles are grown in culture to produce mature eggs that can ultimately be fertilized. Although progress has been made in growing primate primary and secondary follicles in vitro, it has been a relatively greater challenge to isolate and culture primordial follicles. The purpose of this study was to develop methods to grow human primordial follicles in vitro using alginate hydrogels.

Methods

We obtained human ovarian tissue for research purposes through the National Physicians Cooperative from nationwide sites and used it to test two methods for culturing primordial follicles. First, primordial follicles were isolated from the ovarian cortex and encapsulated in alginate hydrogels. Second, 1 mm × 1 mm pieces of 500 μm-thick human ovarian cortex containing primordial follicles were encapsulated in alginate hydrogels, and survival and follicle development within the tissue was assessed for up to 6 weeks.

Results

We found that human ovarian tissue could be kept at 4 °C for up to 24 h while still maintaining follicle viability. Primordial follicles isolated from ovarian tissue did not survive culture. However, encapsulation and culture of ovarian cortical pieces supported the survival, differentiation, and growth of primordial and primary follicles. Within several weeks of culture, many of the ovarian tissue pieces had formed a defined surface epithelium and contained growing preantral and antral follicles.

Conclusions

The early stages of in vitro human follicle development require the support of the native ovarian cortex.     

Administration of neurotoxic doses of MDMA reduces sensitivity to ethanol and increases GAT-1 immunoreactivity in mice striatum

Rationale  

Mice with reduced dopamine activity following neurotoxic doses of 3,4-methylenedioxymethamphetamine (MDMA, ‘ecstasy’) consume more ethanol (EtOH) and show greater preference for EtOH. In keeping with human studies and other animal models where alcohol consumption and preference are also high, MDMA treatment will reduce sensitivity to certain physiological effects of EtOH.     

The Association Between Social Support,Body Mass Index and Increased Risk of Prediabetes: the Cardiovascular Risk in Young Finns Study

Purpose

The psychosocial determinants of prediabetes are poorly understood. The aims of our study were (1) to analyse the association between perceived social support in young adulthood and fasting glucose levels and prediabetes in mid-adulthood in a cohort of healthy Finns, (2) to explore whether body mass index (BMI), inflammation or depression mediate this relationship, (3) and to examine the association between social support trajectory groups and fasting glucose.

Method

A prospective design was used with an analytic sample of 1250 participants aged 3–18 years at baseline (1980) and aged 12–39 years when social support was measured. Fasting glucose and prediabetes were assessed 32 years after baseline. Linear and logistic regression was used to examine the association between social support and the outcome measures. A bootstrapping technique was used to examine mediation effects.

Results

Social support was associated with future glucose levels in women after adjusting for childhood socioeconomic status (SES) and youth depression (β = ?0.136, p = 0.001) and also predicted prediabetes in women after adjusting for childhood SES (β = 1.31, 95 % CI 1.02 to 1.69, p = 0.031). Both associations were attenuated after adjusting for BMI in mid-adulthood. BMI was found to mediate the relationship between social support and prediabetes in women (β for indirect effect β = 0.09, SE = 0.03, CI = 0.03 to 0.16).

Conclusion

Low perceived social support in young adulthood is associated with high fasting glucose and prediabetes in mid-adulthood in women but not men. The association between social support and prediabetes in women can be partly explained by BMI.

     

Personality disorders: a discussion of current status and future directions for research, practice, and policy

This article is the result of a panel discussion on future directions in personality disorders held at the 1998 Meeting of the Society for Psychotherapy Research in Snowbird Utah. Three experts in the field of personality disorders were invited to participate in a dialogue on priorities and directions for research, practice, and policy in this area. Topics discussed amongst the panelists included the following: 1) relevance of psychotherapy process research for treatments of personality disorders, and potential fruitful directions for such research; 2) what has been learned from outcome research in treatment of personality disorders, and directions for such research that are likely to be most productive in improving treatments; 3) the extent to which research has influenced clinical practice and how existing gaps might be addressed; 4) policy questions related to payment for treatment of personality disorders.     

A guide to performing difficult bimanual coordination tasks: just follow the yellow brick road

Both discrete and continuous bimanual coordination patterns are difficult to effectively perform when the two limbs are required to perform different movements patterns, move at different velocities and/or move different amplitudes unless some form of integrated feedback is provided. The purpose of the present experiment was to determine the degree to which a complex bimanual coordination pattern could be performed when integrated feedback and movement template are provided. The complex bimanual coordination pattern involved reciprocal movements of the two limbs under different difficulty requirements. As defined by Fitts’ index of difficulty (ID), the left arm (ID = 3, A = 16°, W = 4°) task was of lower difficulty than the right arm task (ID = 5, A = 32°, W = 2°). Note that the left and right limb movements are also different in terms of movement time, movement velocity, accuracy requirements and amplitude as well as one movement was continuous and the other intermittent. Participants were provided 2 blocks of 9 trials in the bimanual condition (30 s/trial). Following the bimanual phase, participants performed two unimanual test trials—one with each limb. The results demonstrated that the performance for each limb in the bimanual condition was similar to the performance for the same limb and conditions in the unimanual control conditions. The similarity was indicated by the same movement speed, movement structure, endpoint variability and hit rates for the bimanual and unimanual conditions. The results support our hypothesis that people can overcome the intrinsic difficulties associated with performing complex bimanual coordination patterns when provided appropriate perceptual information feedback that allows them to detect and correct coordination errors.     

The role of auditory and visual models in the production of bimanual tapping patterns

An experiment was designed to determine the effectiveness of auditory and visual models in the learning of a 2:3 bimanual tapping pattern. Participants were randomly assigned to an auditory model, visual model, auditory + visual model, or a control (visual metronome) group. The task for all groups was to tap a left side force transducer with the left hand and a right side force transducer with the right hand in attempt to produce the desired 2:3 bimanual coordination pattern. The auditory model consisted of a series of tones representing the goal pattern played prior to each practice trial. The visual model consisted of a visual display representing the goal tapping pattern. Visual pacing metronomes were provided to the control group. The right and left side metronomes flashed during the trial in a pattern representing the goal tapping pattern. Subjects in all groups performed 14 practice trials consisting of 15 s each devoted to tapping the goal pattern (total practice time = 3.5 min). A retention test without the aid of the models or metronomes was administered following the practice trials. The results for the model groups indicated extremely effective performance of the bimanual coordination patterns for the auditory, visual, and auditory + visual model conditions with not only the relative, but also the absolute characteristics of the models exhibited during retention testing. Retention performance for the visual metronome condition was less accurate and more variable than the three model conditions. In addition, the auditory + visual model condition resulted in retention performance that was more stable than the auditory model condition.     

Porous carriers for biomedical applications based on alginate hydrogels

Macroporous scaffolds are typically utilized in tissue engineering applications to allow for the migration of cells throughout the scaffold and integration of the engineered tissue with the surrounding host tissue. A method to form macroporous beads with an interconnected pore structure from alginate has been developed by incorporating gas pockets within alginate beads, stabilizing the gas bubbles with surfactants, and subsequently removing the gas. Macroporous scaffolds could be formed from alginate with different average molecular weights (5-200 kDa) and various surfactants. The gross morphology, amount of interconnected pores, and total void volume was investigated both qualitatively and quantitatively. Importantly, macroporous alginate beads supported cell invasion in vitro and in vivo.     

Apoptosis: a method for evaluating the cryopreservation of whole blood and peripheral blood mononuclear cells

We sought to compare the effect of cryopreservation and storage at -30 degrees C, -70 degrees C and -150 degrees C of human whole blood versus matched peripheral blood mononuclear cell (PBMC) samples using apoptosis as an indicator of cell fitness. Following 10 weeks of storage the samples were thawed and assessed for viability (trypan blue exclusion), levels of apoptosis (using the nuclear stain bis-benzimide) and cell function (ability to be transformed by Epstein-Barr virus, EBV). When comparing storage temperatures, the levels of apoptosis in whole blood and PBMC samples stored at -30 degrees C were significantly higher than the values for samples stored at -70 degrees C or -150 degrees C (P<0.004). Whole blood samples stored at -150 degrees C had significantly less apoptosis than those stored at -70 degrees C (P<0.03). A comparison of the cell preparations showed that at all three storage temperatures there was significant sample deterioration (viability, apoptosis, and function) in whole blood relative to PBMC samples. This study indicates that careful consideration should be given to storage conditions and that apoptosis can be used as a sensitive measure of cell fitness following cryopreservation.