PubMed Health⌕ Search

Biomedical subjects

Frank Nawroth

Publications and source records attributed to Frank Nawroth.

At least 19 recordsLinked to original sources
PubMed2006

Aseptic vitrification of human germinal vesicle oocytes using dimethyl sulfoxide as a cryoprotectant.

OBJECTIVE: To evaluate the viability of vitrified human germinal vesicle (GV)-oocytes to mature to metaphase II (MII) stage after "rapid" cooling directly in liquid nitrogen in comparison with "slow" cooling in a closed 0.5-mL straw (aseptic system), with or without dimethyl sulfoxide (DMSO) in vitrification solution. The possibility of avoiding parthenogenesis of the oocytes after vitrification using DMSO was investigated. DESIGN: In vitro maturation after vitrification. SETTING: Assisted reproduction centers. PATIENT(S): Patients undergoing standard superovulation treatment and having GV-oocytes after follicular puncture. INTERVENTION(S): The GV-oocytes were vitrified with long/short exposure to DMSO using slow or rapid cooling, then warmed and matured in vitro. MAIN OUTCOME MEASURE(S): Maturation after warming. RESULT(S): Oocyte development up to MII stage after vitrification with DMSO was 71% in the group with "rapid" cooling, and in groups with "slow" cooling, 68% and 72% for long and short exposure to DMSO, respectively. The maturation rate of GV-oocytes after slow cooling without DMSO was 51%. In the vitrification with long-term contact of oocytes with DMSO group, a high rate of parthenogenesis was observed. When vitrification with short-term contact of oocytes with DMSO at room temperature was used, no parthenogenesis was observed. CONCLUSION(S): Cryopreservation of human GV-oocytes in open-pulled straws OPS) using an aseptic slow cooling method gives high maturation rates but only in combination with DMSO. To avoid spontaneous parthenogenesis, the exposure to DMSO must occur for a reduced time and at room temperature.

Asepsis↗
PubMed2006

Congenital partial atresia of the Fallopian tube.

Partial tubal atresia is a rare anomaly of unknown pathogenesis. It can occur unilaterally or bilaterally, mainly including the proximal isthmic portion or the proximal ampullary segment ('mid-portion'), and is especially associated with uterine anomalies. Any more extensive pelvic surgery, including preoperative diagnosis of associated urological anomalies, must be well planned in such patients. Salpingostomy and fimbrial approximation is a realistic option in patients with congenital ampullary atresia who wish to have a child. A MEDLINE search was performed and 18 patients found with partial atresia of different tubal portions. This report describes a further patient and reviews the available literature.

Adult↗
PubMed2005

Is there an association between septate uterus and endometriosis?

BACKGROUND: The question of whether Müllerian anomalies are significantly more often combined with endometriosis is a controversially discussed problem. Some publications described this association in patients with obstructive but not non-obstructive Müllerian anomalies or controls without Müllerian anomalies. The aim of this study was to evaluate the incidence of endometriosis in patients with a septate uterus as a non-obstructive form of Müllerian anomalies. METHODS: In a retrospective study, we evaluated 120 patients (29.4 +/- 4.7 years; mean +/- SD) with a septate uterus. The control group consisted of 486 consecutive infertile patients (30.8 +/- 6.3 years) with a normal hysteroscopy and laparoscopy. RESULTS: The incidence of dysmenorrhoea was comparable in both groups, but the incidence of endometriosis was significantly higher in patients with a septate uterus (25.8 versus 15.2%, P = 0.006). CONCLUSION: Our results suggest a higher incidence of endometriosis in patients with a septate uterus. If it can be confirmed by others, the initial finding of a septate uterus in infertile patients should be followed by a combined hysteroscopy and laparoscopy.

Adult↗
PubMed2005

What is the 'ideal' duration of progesterone supplementation before the transfer of cryopreserved-thawed embryos in estrogen/progesterone replacement protocols?

Different studies dealing with the start of progesterone supplementation in assisted reproduction treatment cycles have shown that the problem apparently is the correct timing. We therefore would like to discuss the data on: (i) the start of progesterone replacement in oocyte donation programmes; (ii) the start of progesterone replacement in frozen-thawed hormone-supplemented cycles; (ii) the problem of too early a rise of progesterone in fresh IVF cycles as a model of too early an administration of progesterone; and (iv) the benefit of high progesterone levels on the day of embryo transfer in fresh IVF cycles. From the data reviewed in this paper it seems to be appropriate to start progesterone administration before transfer in oocyte donation programmes as well as transfer of cryopreserved/thawed cells as soon as the endometrium is developed sufficiently (> or =8 mm, trilaminar pattern), and to perform the embryo transfer not before day 3-4 of progesterone treatment, i.e. embryo development on day 2-3. Studies dealing with the influence of too early a rise of progesterone in fresh IVF cycles have shown different results. In fact high progesterone levels seem to reflect a high response but not a lower probability of conception. Furthermore, high progesterone levels on the day of embryo transfer in fresh IVF cycles could lower myometrial contractility and therefore increase implantation rates. Since the experience from oocyte donation programes shows the benefit of a longer preparation time using progesterone, and high progesterone levels seem to have a benefit during embryo transfer, this would suggest extending progesterone administration before transfer. However, we have to find the optimal individual transfer protocol after mock cycles, for example with pinopode detection or other methods applicable in routine IVF programmes. We need more studies to be sure whether reproductive outcome after transfer of cryopreserved-thawed cells in estrogen/progesterone supplement cycles is influenced by the duration of progesterone pretreatment. If this is so, we must look for practicable methods to modify the protocols according to the individual patient, the embryonic developmental stage during transfer and other variables.

Clinical Trials as Topic↗
PubMed2005

Hyperprolactinaemia and the regular menstrual cycle in asymptomatic women: should it be treated during therapy for infertility?

It is known that hyperprolactinaemia can cause galactorrhoea and irregular cycles or even amenorrhoea. High serum prolactin (PRL) can disturb follicular maturation and corpus luteum function. Treatment of hyperprolactinaemia in patients with resulting bleeding anomalies is established, but the question is how to manage normal cyclic hyperprolactinaemic women? Studies have shown that in a subgroup of asymptomatic patients the serum contains mainly high molecular weight form (big big PRL), which has a low bioactivity, called macroprolactinaemia. It is evident that macroprolactin does not affect the control of pituitary PRL secretion via the short loop feedback mechanism or the secretion of gonadotrophins as does monomeric PRL. Identification of macroprolactinaemia is therefore clinically important to prevent unnecessary examinations and inappropriate treatment. Prolactinoma can be associated with macroprolactinaemia. Performance of pituitary imaging in asymptomatic patients with hyperprolactinaemia may therefore be justified, but further studies are needed to evaluate the relation of costs and benefit. An unsolved problem is the differentiation between inactive and PRL-secreting tumours. Caution should be exercised concerning medical treatment in unstimulated patients and also in patients during ovarian stimulation alone or in combination with intrauterine insemination or in-vitro fertilization. The potential clinical significance of hyperprolactinaemia/macroprolactinaemia in asymptomatic women must be further evaluated.

Female↗
PubMed2005

Clean technique for cryoprotectant-free vitrification of human spermatozoa.

Human spermatozoa can be successfully cryopreserved without the use of cryoprotectants through vitrification at very high warming rates. This is achieved by plunging a small amount of frozen sperm suspension into a warming medium, or a large amount of sperm suspension into an agitated warming medium. The aim of the present study was to compare the motility of human spermatozoa cryopreserved using four different methodologies of cooling and warming: cryoloops, droplets, open-pulled straws and standard open straws. Evaluation of two parameters, motility and viability rate of spermatozoa, suggests that all four methods are suitable for use in assisted reproductive technology. However, only the use of open-pulled straws as well as standard open straws allows the isolation of spermatozoa from liquid nitrogen with low potential risk of microbial contamination during freezing and storage, and is thereby a clean method of vitrification.

Cell Survival↗
PubMed2005

Cryopreservation in assisted reproductive technology: new trends.

During the last few years, cryopreservation has become a relevant addition to therapeutic concepts in reproductive medicine. New data and publications have made it difficult to maintain an overview of all of the new developments and their results. The focus of interest more recently, especially with the cryopreservation of human oocytes and human ovarian tissue, has been vitrification as an interesting alternative to slow freezing methods. Even though studies investigating the slow freezing of human mature oocytes have resulted in very different survival rates, it could be an option for donor oocyte programs, in the case of threatened ovarian loss or when there is an objection to embryo freezing. An optimal freezing protocol and later use of thawed human ovarian tissue is still a point of discussion. There are encouraging results regarding different kinds of autotransplantation, and recently the first birth after orthotopic autotransplantation of cryopreserved/thawed human ovarian tissue was described in the literature. Independent of any objections to cryopreservation in general, vitrification is a potential and effective alternative to conventional slow cryopreservation, especially for oocytes and embryos. Vitrification might be also be an option for human ovarian tissue; however this is only in its infancy and requires much additional investigation. Our article discusses new trends and results of actual studies regarding these issues.

Cryopreservation↗
PubMed2005

Course of pregnancy and birth in a patient with Bernard-Soulier syndrome--a case report.

Bernard-Soulier syndrome is a rare autosomal recessive bleeding disorder characterized by platelet dysfunction, the presence of giant platelets, and a prolonged bleeding time. Absent or reduced expression of the platelet glycoprotein (GP) Ib-IX receptor results in the Bernard-Soulier syndrome and is characterized by severe bleeding and macrothrombocytopenia. To our knowledge only ten pregnant patients with this disease have been previously reported. In some patients the pregnancy course was uneventful while in others post-partum hemorrhage and resulting hysterectomy was the most common complication. We present a primiparous female with Bernard-Soulier syndrome who had delayed post-partum hemorrhage and review the literature.

Adult↗
PubMed2004

Cryoprotectant-free cryopreservation of human spermatozoa by vitrification and freezing in vapor: effect on motility, DNA integrity, and fertilization ability.

Human spermatozoa can be successfully cryopreserved avoiding the use of cryoprotectants through vitrification at very high cooling rates (up to 7.2 x 10(5) degrees C/min). This is achieved by directly plunging a copper cryoloop loaded with a sperm suspension into liquid nitrogen. After storage, vitrified spermatozoa are instantly thawed by melting in an agitated, warm medium. The goal of the present study was to compare the quality of spermatozoa cryopreserved using this rapid vitrification method with that of spermatozoa cooled relatively slowly by preexposure of the loaded cryoloop to liquid nitrogen vapor (-160 degrees C) with speed in the range 150-250 degrees C/min) before immersion into liquid nitrogen. Both cooling modes led to comparable results in terms of the motility, fertilization ability, and DNA integrity of the warmed spermatozoa. In both cases, instant thawing by melting in a warm medium was essential for successful cryopreservation. Our findings suggest that optimal regimes for the cryoprotectant-free cryopreservation of spermatozoa need not be restricted to very fast cooling before storage in liquid nitrogen, a wide range of cooling rates being acceptable. Herein, we discuss the implications of this finding in the light of the physics of extra- and intracellular vitrification.

Cryopreservation↗
PubMed2004

Developmental rate and ultrastructure of vitrified human pronuclear oocytes after step-wise versus direct rehydration.

BACKGROUND: This study compared the viability of human pronuclear oocytes subjected to vitrification followed by post-thaw step-wise removal of cryoprotectants versus direct rehydration, in terms of their subsequent in vitro survival and ultrastructural features. METHODS: A total of 115 three-pronuclei stage oocytes were cryopreserved in super-open-pulled straws by vitrification in 40% ethylene glycol + 0.75 mol/l sucrose for either 1 min or 10 s at 38 degrees C, followed by direct plunging into liquid nitrogen. After thawing, oocytes vitrified for 1 min (group 1) or 10 s (group 2) were expelled into a graded series of sucrose solutions (1.0, 0.75, 0.5, 0.25 and 0.12 mol/l) for removal of the cryoprotectant in five 2.5 min steps. A second batch of oocytes vitrified for either 1 min (group 3) or 10 s (group 4) were directly expelled into culture medium at 38 degrees C after thawing. Finally, the ultrastructural changes occurring in oocytes in each of the treatment groups were evaluated. RESULTS: Oocyte development (division to two-blastomere stage) rates after in vitro culture were 82, 83, 0 and 0% for groups 1, 2, 3 and 4, respectively. The harsh osmotic process involved in direct rehydration provoked ultrastructural changes, including the disruption of cytoplasmic and pronuclear membranes as well as intracellular organelles. CONCLUSION: The direct post-thaw rehydration of human pronuclear oocytes has lethal osmotic effects, such that protocols for vitrifying human pronuclear oocytes should include the step-wise removal of the cryoprotectant.

Adult↗
PubMed2004

In-vitro maturation of germinal-vesicle oocytes and cryopreservation in metaphase I/II: a possible additional option to preserve fertility during ovarian tissue cryopreservation.

This study describes the possibility of combining two options in order to preserve female fertility: cryopreservation of human ovarian tissue and in-vitro matured germinal vesicle (GV) oocytes retrieved during tissue dissection. In contrast to ovarian tissue cryopreservation, the cryostorage of in-vitro matured unfertilized metaphaseI/II oocytes could be a more realistic option. This concept of preserving fertility before chemotherapy and/or radiotherapy without a long time delay could be an additional reason for favouring ovarian tissue cryopreservation. This concept is discussed in regard to two cases.

Adult↗
PubMed2004

Monozygotic triplets and monozygotic twins after ICSI and transfer of two blastocysts: case report.

There are data regarding the possible influences of extended embryo culture to the blastocyst stage as well as zona pellucida manipulation on the incidence of monozygotic multiples. This is interesting, as one aim of extended culture with embryo selection is to minimize the multiple pregnancy rate. We report, to our knowledge, on the first case of monozygotic twins and monozygotic triplets after ICSI and the transfer of two blastocysts. Monozygotic multiples after ICSI and blastocyst transfer and the resulting problems are another reason to encourage the transfer of only one blastocyst. Theories about risk factors and the pathophysiology of monozygotic multiples will be discussed both in terms of this case report and of the literature. In our opinion, the incidence of 5.9-8.9% monozygotic multiple occurrence after ICSI and blastocyst transfer reported in the literature requires that patients are informed of the uncertainties until this phenomenon and its risk factors are better understood.

Adult↗