Kryokonservierung und Transplantation von Ovarialgewebe

There are relatively few effective clinical options for preserving female fertility, particularly following aggressive chemotherapy and/or radiotherapy treatment protocols. This document reviews scientific background, current technology, clinical results, and potential future applications of ovarian tissue cryopreservation and transplantation. The technology is investigational although rapidly evolving, and the list of appropriate indications may be expanded in the future. Germany stays abreast of these rapid worldwide developments by having founded the first German network of experts for fertility preservation in patients undergoing chemotherapy and/or radiotherapy.     

Aseptic technology of vitrification of human pronuclear oocytes using open-pulled straws

BACKGROUND: The aim of this study was to compare the viability of human pronuclear oocytes subjected to vitrification using cooling by direct submerging of open-pulled straws in liquid nitrogen versus vitrification by cooling of open-pulled straws located inside a closed 0.5 ml straw (aseptic system). METHODS: Two- and three-pronuclei stage oocytes (n=114) were cryopreserved in super-open-pulled straws by vitrification in 20% ethylene glycol +20% dimethylsulphoxide (DMSO) + osmotic active and neutral non-permeable cryoprotectants with a four-step exposure in 20, 33, 50 and 100% vitrification solution for 2, 1 and 1 min, and 30-50 s, respectively at room temperature, and plunging into liquid nitrogen. Oocytes of group 1 (n=42) were rapidly cooled at a speed of 20,000 degrees C/min by direct plunging of open-pulled straws into liquid nitrogen. Oocytes of group 2 (n=44) were first located in 0.5 ml straws, which were closed at both sides by metal balls, and then plunged into liquid nitrogen. This method resulted in a cooling speed of 200 degrees C/min. For both groups, oocytes were thawed rapidly at a speed of 20 000 degrees C/min using an identical protocol. Oocytes subsequently were expelled into a graded series of sucrose solutions (1.0, 0.75, 0.5, 0.25 and 0.12 mol/l) at 2.5 min intervals. RESULTS: Oocyte development up to expanded blastocyst stage after in vitro culture was 15% in group 1, 14% in group 2 and 29% in an untreated control group. CONCLUSION: The deposition of human pronuclear oocytes in open-pulled straws which are placed inside a hermetically closed container guarantees a complete isolation of oocytes from liquid nitrogen and avoids potential contamination by pathogenic microorganisms. The combination of direct plunging of this container into liquid nitrogen and rapid warming makes this process as efficient as conventional vitrification.     

Increased frequency of congenital chromosomal aberrations in female partners of couples undergoing intracytoplasmic sperm injection

We evaluated the frequency of congenital chromosomal aberrations in a sample of 305 couples included in an intracytoplasmic sperm injection (ICSI) programme. Twenty individuals (3.3%) with congenital chromosomal abnormalities could be identified. The following types of abnormalities were observed: reciprocal translocations (n = 7), Robertsonian translocations (n = 3), inversions (n = 3), other structural aberrations (n = 4) and sex chromosome aberrations (n = 3). The rate of chromosomally abnormal males (10/305, 3.3%) lay within the expected range for patients with reduced semen quality. Surprisingly, 50% (10/20) of all abnormal karyotypes were contributed by the female partner of ICSI patients. These data confirm the higher incidence of chromosomal aberrations in infertile populations as compared with the baseline population risk. Additionally, the data imply that in some cases of male factor infertility a hidden female chromosomal factor may be present, which cannot be identified by standard clinical evaluation. In conclusion, we recommend chromosomal analysis in both partners of couples undergoing ICSI treatment.      

Sarcocystis gigantea lectin — mitogen and polyclonal B-cell activator

The present study further examined the in vitro response of human mononuclear cells (MNC) to theSarcocystis gigantea lectin (SGL). The results confirm our previous report that SGL is mitogenic for human MNC. We now report that SGL is not only a potent mitogen but also a polyclonal activator for human peripheral B cells. As was true for pokeweed mitogen (PWM, 2 g/ml), the addition of SGL (25 g protein/ml) to cultures of MNC caused lymphocyte proliferation and B-cell maturation, indicated by a marked increase in IgG and IgM production. As measured by the [³H]-thymidine incorporation assay, SGL induced significantly higher proliferative responses than PWM (P<0.01,n=24). The values obtained by SGL and PWM for IgG and IgM synthesis were essentially identical. As opposed to SGL, the sarcotoxin-containing fraction (SGTF) did not induce antibody formation or proliferative responses in human MNC.     

Aneurysmal bone cyst of the extremities. Factors related to local recurrence after curettage with a high-speed burr

BACKGROUND: Aneurysmal bone cyst is a benign, locally destructive lesion of bone. The rates of local recurrence after curettage have varied widely. Therefore, we performed a retrospective study of patients who had had an aneurysmal bone cyst in order to identify the rate of local recurrence and the prognostic factors related to local recurrence after use of contemporary methods of curettage with a high-speed burr. METHODS: We reviewed the cases of forty patients who had been managed by the same surgeon for an aneurysmal bone cyst, as diagnosed on the basis of the latest pathological review, between January 1, 1976, and December 31, 1993. The patients were evaluated with regard to age, gender, the duration and type of symptoms, the presence or absence of pathological fracture, the status of the growth plate, the bone and part of the bone that were involved, the type of operative procedure, the outcome, the radiographic stage, the findings on magnetic resonance imaging and computerized tomography (when it became available) and on bone scintigraphy, and histological parameters. The median duration of follow-up was eighty-seven months (range, fifteen to 267 months). According to the criteria of Enneking, no patient had a stage-1 lesion (one with a surrounding rim of cortical bone), twenty-four had a stage-2 lesion (one with a clearly defined border but no cortical bone), and sixteen had a stage-3 lesion (one with no clearly defined border). RESULTS: Of the forty patients, thirty-four had curettage with use of a high-speed burr. Of these thirty-four, twenty-two had filling of the defect with a cancellous autogenous graft; four, with a cancellous allograft; and three, with polymethylmethacrylate. In five patients, no material was put into the defect. The remaining six patients had resection through the margin of the lesion. Four (12 percent) of the thirty-four patients who had curettage had a local recurrence. No patient who had an excision through the margin of the lesion had a local recurrence. All local recurrences were in skeletally immature girls who were three, four, ten, and eleven years old. Univariate analysis with use of the chi-square, Fisher exact, and Wilcoxon log-rank tests showed that local recurrence was associated only with a young age (p = 0.0036) and open growth plates (p = 0.039). All local recurrences occurred within two years postoperatively, at two, seven, nine, and twenty-four months, and all were treated successfully with a second operation. CONCLUSIONS: Rates of local control of almost 90 percent can be achieved with thorough curettage with use of a mechanical burr and without use of liquid nitrogen, phenol, or other adjuvants in patients who have an aneurysmal bone cyst of an extremity. A young age and open growth plates are associated with an increased risk of local recurrence.     

Generierung und Konservierung von Keimzellen

In vitro maturation (IVM) is a technique which allows the maturation of oocytes from the germinal vesicle stage up to the stage of the fertilization-competent metaphase-II oocytes. Immature oocytes are primarily retrieved from small antral follicles. Their successful maturation is usually documented by formation of the first polar body as an indicator of completion of the first meiotic division. The quality of in vitro matured oocytes can now be judged by polarisation microscopy. This technique allows better quality assessment and is hence a unique instrument for optimising existing IVM protocols. In combination with the now realistic option of successful cryopreservation of mature and immature oocytes by the technique of vitrification, IVM will soon enter new fields of application.     

Current aspects of therapeutic reduction mammaplasty for immediate early breast cancer management: An update

Breast-conservation surgery (BCS) is established as a safe surgical treatment for most patients with early breast cancer. Recently, advances in oncoplastic techniques are capable of preserving the breast form and quality of life. Although most BCS defects can be managed with primary closure, the aesthetic outcome may be unpredictable. Among technical options, therapeutic reduction mammaplasty (TRM) remains a useful procedure since the BCS defect can be repaired and the preoperative appearance can be improved, resulting in more proportional breasts. As a consequence of rich breast tissue vascularization, the greater part of reduction techniques have based their planning on preserving the pedicle of the nipple-areola complex after tumor removal. Reliable circulation and improvement of a conical shape to the breast are commonly described in TRM reconstructions. With an immediate approach, the surgical process is smooth since both procedures can be carried out in one operative setting. Additionally, it permits wider excision of the tumor, with a superior mean volume of the specimen and potentially reduces the incidence of margin involvement. Regardless of the fact that there is no consensus concerning the best TRM technique, the criteria is determined by the surgeon’s experience, the extent/location of glandular tissue resection and the size of the defect in relation to the size of the remaining breast. The main advantages of the technique utilized should include reproducibility, low interference with the oncological treatment and long-term results. The success of the procedure depends on patient selection, coordinated planning and careful intra-operative management.     

Addressing Methodologic Challenges and Minimizing Threats to Validity in Synthesizing Findings from Individual-Level Data Across Longitudinal Randomized Trials

Integrative Data Analysis (IDA) encompasses a collection of methods for data synthesis that pools participant-level data across multiple studies. Compared with single-study analyses, IDA provides larger sample sizes, better representation of participant characteristics, and often increased statistical power. Many of the methods currently available for IDA have focused on examining developmental changes using longitudinal observational studies employing different measures across time and study. However, IDA can also be useful in synthesizing across multiple randomized clinical trials to improve our understanding of the comprehensive effectiveness of interventions, as well as mediators and moderators of those effects. The pooling of data from randomized clinical trials presents a number of methodological challenges, and we discuss ways to examine potential threats to internal and external validity. Using as an illustration a synthesis of 19 randomized clinical trials on the prevention of adolescent depression, we articulate IDA methods that can be used to minimize threats to internal validity, including (1) heterogeneity in the outcome measures across trials, (2) heterogeneity in the follow-up assessments across trials, (3) heterogeneity in the sample characteristics across trials, (4) heterogeneity in the comparison conditions across trials, and (5) heterogeneity in the impact trajectories. We also demonstrate a technique for minimizing threats to external validity in synthesis analysis that may result from non-availability of some trial datasets. The proposed methods rely heavily on latent variable modeling extensions of the latent growth curve model, as well as missing data procedures. The goal is to provide strategies for researchers considering IDA.

     

Proinsulin processing by the subtilisin-related proprotein convertases furin, PC2, and PC3.

Experiments using recombinant vaccinia viruses expressing rat proinsulin I coinfected into COS-7 cells with recombinant vaccinia virus expressing human furin, human PC2, mouse PC3 (subtilisin-related proprotein convertases 1-3, respectively), or yeast Kex2 indicate that in this system both Kex2 and furin produce mature insulin, whereas PC2 selectively cleaves proinsulin at the C-peptide-A-chain junction. This is a property consistent with its probable identity with the rat insulinoma granule type II proinsulin processing activity as described by Davidson et al. [Davidson, H. W., Rhodes, C. J. & Hutton, J. C. (1988) Nature (London) 333, 93-96]. PC3 generates mature insulin but cleaves preferentially at the proinsulin B-chain-C-peptide junction. This pattern of cleavage by PC3 is similar, but not identical, to that of the highly B-chain-C-peptide junction-selective type I activity as described by Davidson et al., perhaps due to the presence of a P4 arginine residue near the C-peptide-A-chain junction unique to the rat proinsulins. These results along with data presented on the expression of both PC2 and PC3 in islet beta cells strongly support the conclusion that these proteases are involved in the conversion of proinsulin to insulin in vivo.