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Vesicovaginal fistulas-vault fistulas as they are called when located at the vaginal apex following total hysterectomy-are rare lesions that are located on the anterior vaginal wall just in front of the transverse vaginal scar made when the cervix is removed. Latzko, in 1942, described a technique of treating vault fistulas solely through a vaginal approach. A vault colpocleisis is performed without attempting to dissect the fistulous tract. Although this is an effective and relatively simple procedure, there is as yet no consensus on first-line treatment of these lesions. The authors report the results of the Latzko procedure in 11 women with a mean age of 50 years who had a postoperative vesicovaginal fistula. All but one of the fistulas followed total hysterectomy. The mean interval between primary surgery and a fistula was just short of 2 weeks. Urethral bladder drainage for 5-8 days did not prevent a fistula from forming in these patients.Urinary drainage was maintained for at least 6 weeks before surgical repair. The fistula was drawn downward using a balloon catheter placed in its opening and was then circumcised 1.5 to 2 cm from the opening. All epithelium from the circumcised area to the edge of the fistula's opening was removed before approximating the anterior and posterior vaginal walls using interrupted absorbable sutures. The vaginal mucosa then was closed by a second layer of sutures. The bladder was drained with a Foley catheter until the cystogram was normal.The Latzko procedure succeeded in all cases as evidenced by the absence of urine loss during a bladder tightness test 1 month postoperatively. There were no intraoperative complications, and the only postoperative problem was a lower urinary tract infection. The patients were followed for a mean of 19 months after repair. These results show that the Latzko procedure is a safe, technically simple, and effective means of treating vault vesicovaginal fistulas. The investigators recommend it as the most appropriate first-line surgical treatment. GYNECOLOGYVolume 62, Number 1 OBSTETRICAL AND GYNECOLOGICAL SURVEY ABSTRACTObjective cure rates exceeding 75% are reported after colposuspension in women with stress incontinence, but extended follow-up has not been the rule. Small-scale studies also have been done to evaluate laparoscopic colposuspension after its introduction in 1991. A Cochrane review in the year 2000 yielded no conclusions about the long-term efficacy of this procedure.The present randomized controlled trial recruited, from six gynecology units in the United Kingdom, 291 women with proven stress urinary incontinence who required surgery. Participants were randomized to undergo open abdominal retropubic colposuspension or laparoscopic colposuspension. Subjective outcomes were based on patient satisfaction, and objective outcomes on a negative 1-hour pad test. Data on objective outcomes were available after 2 years of follow-up in 85% of women having laparoscopic surgery and 80% of those having open surgery. The respective figures for s...

The derivation of human embryonic stem (hES) cells currently requires the destruction of ex utero embryos. A previous study in mice indicates that it might be possible to generate embryonic stem (ES) cells using a single-cell biopsy similar to that used in preimplantation genetic diagnosis (PGD), which does not interfere with the embryo's developmental potential. By growing the single blastomere overnight, the resulting cells could be used for both genetic testing and stem cell derivation without affecting the clinical outcome of the procedure. Here we report a series of ten separate experiments demonstrating that hES cells can be derived from single blastomeres. In this proof-of-principle study, multiple biopsies were taken from each embryo using micromanipulation techniques and none of the biopsied embryos were allowed to develop in culture. Nineteen ES-cell-like outgrowths and two stable hES cell lines were obtained. The latter hES cell lines maintained undifferentiated proliferation for more than eight months, and showed normal karyotype and expression of markers of pluripotency, including Oct-4, SSEA-3, SSEA-4, TRA-1-60, TRA-1-81, nanog and alkaline phosphatase. These cells retained the potential to form derivatives of all three embryonic germ layers both in vitro and in teratomas. The ability to create new stem cell lines and therapies without destroying embryos would address the ethical concerns of many, and allow the generation of matched tissue for children and siblings born from transferred PGD embryos.

Gamma aminobutyric acid (GABA)-expressing interneurons are the major inhibitory cells of the cerebral cortex and hippocampus. These interneurons originate in the medial ganglionic eminence (MGE) and lateral ganglionic eminence of the ventral forebrain during embryonic development and show reduced survival and function in a variety of neurological disorders, including temporal lobe epilepsy. We and others have proposed that embryonic stem cell (ESC)-derived ventral forebrain progenitors might provide a source of new GABAergic interneurons for cell-based therapies. While human ESCs (hESCs) are readily differentiated in vitro into dorsal telencephalic neural progenitors, standard protocols for generating ventral subtypes of telencephalic progenitors are less effective. We now report efficient derivation of GABAergic progenitors using an established hESC reporter line that expresses green fluorescent protein (GFP) under the control of an endogenous NKX2.1 promoter. GABAergic progenitors were derived from this hESC line by a modified monolayer neural differentiation protocol. Consistent with sonic hedgehog (SHH)-dependent specification of NKX2.1-positive progenitors in the embryonic MGE, we show a dose-dependent increase in the generation of NKX2.1:GFP-positive progenitors after SHH treatment in vitro. Characterization of NKX2.1:GFP-positive cells confirms their identity as MGE-like neural progenitors, based on gene expression profiles and their ability to differentiate into GABAergic interneurons. We are also able to generate highly enriched populations of NKX2.1:GFP-positive progenitors, including cells with telencephalic identity, by fluorescence-activated cell sorting. These hESC-derived ventral forebrain progenitors are suitable candidates for cell-based therapies that aim at replacing dysfunctional or damaged cortical or hippocampal GABAergic interneurons.

(this issue) At the request of the Editors at Nature, we wish to clarify some questions that have arisen since the advance online publication (AOP) of our Letter on 23 August 2006. In our Letter, we showed that human embryonic stem-cell lines can be generated from a single cell after its removal from an 8-10-cell embryo. To minimize the number of embryos used, we removed multiple cells from each embryo, and none of the biopsied embryos were allowed to develop in culture.In our experiments, the isolated blastomeres from each embryo were cultured together in the same medium that was used to culture the parent embryo, and were arranged to avoid contact with each other. Diffusible factors from the other blastomeres present in the media may assist recovery and growth of the blastomere. We have not excluded the possibility that only a subset of blastomeres of an 8-10-cell embryo are capable of forming human embryonic stem cells. These caveats are worth considering for future studies, but do not negate our central finding that blastomeres extracted from an 8-10-cell embryo by mechanical micromanipulation can form human embryonic stem-cell cultures.We have now added more explicit information on how individual embryos were handled in the form of a table based on Supplementary Table 1 of the AOP version of the Supplementary Information (which has now been removed). This information is now presented in the printed paper as Table 1, to indicate how many cells were individually biopsied from each embryo. In addition, the descriptions for Fig. 4b and d in the legend to Fig. 4 have been corrected (they were inadvertently transposed in the AOP version of the paper).These clarifications have been incorporated into the paper for the print version and are individually listed as Supplementary Information to this Addendum.Supplementary Information is linked to the online version of the paper at www.nature.com/nature. Insights into social insects from the genome of the honeybee Apis melliferaThe Honeybee Genome Sequencing Consortium Nature 443, 931-949 (2006) In this Article, the surname of co-author L. Sian Gramates was misspelled Grametes. Potential of stem-cell-based therapies for heart disease Deepak Srivastava & Kathryn N. Ivey Nature 441, 1097-1099 (2006) It has been drawn to our attention (by J. Lakota, and by J. J. Minguell and G. P. Lasala) that we used the abbreviation for bone-marrowderived stem cells (BMSCs) inappropriately in some parts of our Insight Progress article. BMSC is a commonly used acronym for the heterogeneous adult stem cells in bone marrow. The term BMSC was used with this intention, but was placed after describing a study on bone-marrow-derived mesenchymal stem cells, which are a subset of BMSCs. Subsequent references to BMSCs were intended to describe the heterogeneous cells, rather than the specific mesenchymal subtype. Most clinical trials for myocardial infarction used BMSCs and have so far had mixed results. Future trials with isolated mesenchymal stem cells will reveal their potential in the c...

There is renewed interest in using animal oocytes to reprogram human somatic cells. Here we compare the reprogramming of human somatic nuclei using oocytes obtained from animal and human sources. Comparative analysis of gene expression in morula-stage embryos was carried out using single-embryo transcriptome amplification and global gene expression analyses. Genomic DNA fingerprinting and PCR analysis confirmed that the nuclear genome of the cloned embryos originated from the donor somatic cell. Although the human-human, human-bovine, and human-rabbit clones appeared morphologically similar and continued development to the morula stage at approximately the same rate (39, 36, and 36%, respectively), the pattern of reprogramming of the donor genome was dramatically different. In contrast to the interspecies clones, gene expression profiles of the human-human embryos showed that there was extensive reprogramming of the donor nuclei through extensive upregulation, and that the expression pattern was similar in key upregulation in normal control embryos. To account for maternal gene expression, enucleated oocyte transcriptome profiles were subtracted from the corresponding morula-stage embryo profiles. t-Test comparisons (median-normalized data @ fc>4; p<0.005) between human in vitro fertilization (IVF) embryos and human-bovine or human-rabbit interspecies somatic cell transfer (iSCNT) embryos found between 2400 and 2950 genes that were differentially expressed, the majority (60-70%) of which were downregulated, whereas the same comparison between the bovine and rabbit oocyte profiles found no differences at all. In contrast to the iSCNT embryos, expression profiles of human-human clones compared to the age-matched IVF embryos showed that nearly all of the differentially expressed genes were upregulated in the clones. Importantly, the human oocytes significantly upregulated Oct-4, Sox-2, and nanog (22-fold, 6-fold, and 12-fold, respectively), whereas the bovine and rabbit oocytes either showed no difference or a downregulation of these critical pluripotency-associated genes, effectively silencing them. Without appropriate reprogramming, these data call into question the potential use of these discordant animal oocyte sources to generate patient-specific stem cells.

Embryo-derived stem cells hold enormous potential for producing cell-based transplantation therapies, allowing high-throughput drug screening and delineating early embryonic development. However, potential clinical applications must first be tested for safety and efficacy in preclinical animal models. Due to physiological and genetic parity to humans, the domestic dog is widely used as a clinically relevant animal model for cardiovascular, neurodegenerative, orthopedic, and oncologic diseases. Therefore, we established numerous putative canine embryonic stem cell (cESC) lines by immunodissection of the inner cell mass (ICM), which we termed OVC.ID.1-23, and by explant outgrowths from whole canine blastocysts, named OVC.EX.1-16. All characterized lines were immunopositive for OCT4, SOX2, NANOG, SSEA-3, and SSEA-4; displayed high telomerase and alkaline phosphatase (ALP) activities; and were maintained in this state up to 37 passages ( approximately 160 days). Colonies from OVC.EX lines showed classic domed hESC-like morphology surrounded by a ring of fibroblast-like cells, whereas all OVC.ID lines exhibited a mixed cell colony of tightly packed cESCs surrounded by a GATA6+/CDX2- hypoblast-derived support layer. Spontaneous serum-only differentiation without feeder layers demonstrated a strong lineage selection associated with the colony niche type, and not the isolation method. Upon differentiation, cESC lines formed embryoid bodies (EB) comprised of cells representative of all germinal layers, and differentiated into cell types of each layer. Canine ESC lines such as these have the potential to identify differences between embryonic stem cell line derivations, and to develop or to test cell-based transplantation therapies in the dog before attempting human clinical trials.