Written by a surgeon with 40 years' experience in practice and instruction, this book provides vital, up-to-date information that explains the strengths and weaknesses of the laparoscopic surgery ...field to enable potential surgical patients to make the best decisions and choose a surgeon wisely.- Presents balanced, unbiased information that identifies the tremendous advantages of less invasive operations using specific examples of laparoscopic techniques and discusses the serious risks and concerns that exist for surgical patients- Provides specific, actionable guidance for choosing a surgeon that identifies what questions to ask and explains how to ensure that a surgeon has enough experience with the particular operation you need- Explains how the success of the laparoscopic revolution that began in the late 1980s has resulted in a new definition of surgeon capability-and how the more complicated education, training, and technology that laparoscopy entails has set the stage for a perfect surgical storm
The DAZ gene cluster on the human Y chromosome is a candidate for the Azoospermia Factor (AZFc). According to the current evolutionary model, the DAZ cluster derived from the autosomal homolog DAZL1 ...through duplications and rearrangements and is confined to Old World monkeys, apes and humans. To study functional and evolutionary aspects ofthis gene family we have isolated from a cynomolgus (Old World) monkey testis cDNA library the Y chromosomal cynDAZ and the autosomal cynDAZL1 cDNA. cynDAZL1 contains one DAZ repeat and displays high homology to human DAZL1. cynDAZ comprises 11 repeats, each consisting of exons 7 and 8, whereas the human DAZcDNA repeat units contain predominantly exon 7. Genomic studies revealed the same amplification events of a 2.4 kb genomic unit encompassing exons 7 and 8 in both species, indicating that after splitting of the two lineages, in the human mainly exon 8 was converted to a pseudoexon by splice site mutations. The structural features of cynDAZreveal a more detailed model for the sequence of events leading to the present form of human DAZ. Thus, in a monkey species DAZis present in a form more ancestral than that of the human. Studies on the immunolocalization of cynDAZDAZLI in cynomolgus monkey testis revealed a biphasic expression pattern with proteins being detectable in A-pale to B-spermatogonia, late spermatocytes and spermatids, but not in early spermatocytes and late spermatids. In contrast, in the marmoset monkey, an animal lacking DAZ, DAZL1 protein was only expressed in late spermatocytes and early spermatids. These findings point to an additional function of cynDAZcynDAZL1 during spermato-genesis in the Old World monkey not needed in the New World monkey.
The autosomal homologs of the human Y-chromosomal DAZ gene (DAZH and Dazh in human and mouse, respectively) are strong candidate for Azoospermia factor and encode a testis specific RNA-binding ...proteins. We studied the expression pattern of the mouse Dazh during embryonic development by using Northern-blotting of developing gonads. In the mouse, we have detected 3.5 kb and 4.5 kb transcripts in male and female embryonic gonads at 12.5 dpc (days post coitum). During this period, the only germ cells present in the gonad are primordial germ cells. Dazh transcripts were not detected in embryonic gonads of mice that lack germ cells because of mutation in W gene, suggesting that expression is limited to germ-cells. In females, oogonia enter meiosis at 13.5-14.5 dpc: at this time Dazh transcription levels are similar to those of the male (when prospermatogonia are in the male gonad). Transcription levels decrease steadily after birth as the number of oocytes is depleted and is hardly detectable by puberty. A human DAZH transcript was also detected by Northern-blotting in the human ovary in levels which are of about 100 fold lower than those observed in the human testis. The expression of the Dazh in male and female gonad before germ cell sex differentiation suggests that these genes may act at the first phase of male and female gametogenesis.
Motivation: Supertree methods have been often identified as a possible approach to the reconstruction of the ‘Tree of Life’. However, a limitation of such methods is that, typically, they use just ...leaf-labelled phylogenetic trees to infer the resulting supertree. Results: In this paper, we describe several new supertree algorithms that extend the allowable information that can be used for phylogenetic inference. These algorithms have been recently implemented and we describe here two illustrative applications. Availability: These new algorithms are freely available for application at http://darwin.zoology.gla.ac.uk/cgi-bin/build.pl
In recent years, the cost of providing quality cancer care has been subject to an epic escalation causing concerns on the verge of a health care crisis. Innovative patient-management models in ...oncology based on patient-centered medical home (PCMH) principles, coupled with alternative payments to traditional fee for service (FFS), such as bundled and episodes payment are now showing evidence of effectiveness. These efforts have the potential to bend the cost curve while also improving quality of care and patient satisfaction. However, going forward with FFS alternatives, there are several performance-based payment options with an array of financial risks and rewards. Most novel payment options convey a greater financial risk and accountability on the provider. Therefore, the oncology medical home (OMH) can be a way to mitigate some financial risks by sharing savings with the payer through better global care of the patient, proactively preventing complications, emergency department (ED) visits, and hospitalizations. However, much of the medical home infrastructure that is required to reduced total costs of cancer care comes as an added expense to the provider. As best-of-practice quality standards are being elucidated and refined, we are now at a juncture where payers, providers, policymakers, and other stakeholders should work in concert to expand and implement the OMH framework into the variety of oncology practice environments to better equip them to assimilate into the new payment reform configurations of the future.
Platinum compounds with the diaminocyclohexane (dach) carrier ligand are of particular interest because cell lines that have developed resistance to platinum compounds in general often retain ...sensitivity to dach-platinum compounds, suggesting that the dach carrier ligand affects the formation, repair, or lethality of platinum-DNA adducts. The effect of the dach ligand on platinum adduct formation was assessed by using the (HaeIII-HindIII)146 fragment of pBR322 treated to give equal amounts of dach- or ethylene-diamine-platinum adducts. The sites of adduct formation were mapped by digestion with Escherichia coli ABC excinuclease. There were no significant effects of the dach carrier ligand on the types or sites of platinum adduct formation. The effect of the dach ligand on platinum adduct repair was determined by using synthetic oligomers designed to have single, specific platinum adducts (G monoadduct; GG, AG, or GNG diadduct) with either the dach or ethylenediamine (en) carrier ligand. These adducts differed significantly in their ability to serve as substrates for ABC excinuclease with GNG greater than or equal to G greater than AG greater than GG. The dach carrier ligand had little effect on the recognition of AG and GG adducts by ABC excinuclease, but significantly improved the ability of ABC excinuclease to excise G monoadducts and GNG diadducts. These data suggest that if the carrier ligand has any effect on the repair of platinum adducts, it is more likely to exert that effect on the repair of platinum monoadducts or GNG diadducts rather than on the more abundant AG or GG diadducts. 14CThiourea incorporation was used to quantitate the rate of monoadduct to diadduct conversion.
A deletion map of the human Y chromosome was constructed by testing 96 individuals with partial Y chromosomes for the presence or absence of many DNA loci. The individuals studied included XX males, ...XY females, and persons in whom chromosome banding had revealed translocated, deleted, isodicentric, or ring Y chromosomes. Most of the 132 Y chromosomal loci mapped were sequence-tagged sites, detected by means of the polymerase chain reaction. These studies resolved the euchromatic region (short arm, centromere, and proximal long arm) of the Y chromosome into 43 ordered intervals, all defined by naturally occurring chromosomal breakpoints and averaging less than 800 kilobases in length. This deletion map should be useful in identifying Y chromosomal genes, in exploring the origin of chromosomal disorders, and in tracing the evolution of the Y chromosome.
Immune responses are shaped by several processes that promote responses to pathogens and hinder responses to self. One mechanism that contributes to this polarization in response is negative ...selection, in which thymocytes that can respond to self-peptide/MHC complexes are deleted from the T cell repertoire. I found here that several coreceptors known to contribute to mature T cell activation also participate in negative selection. Interestingly, these molecules appeared to act in a cooperative fashion. Blocking the contribution of these molecules in fetal thymus organ culture not only prevented negative selection in the CD4+ lineage, but also induced the appearance of autoreactive thymocytes. This is the first demonstration that blocking coreceptor interactions during thymic development can produce autoreactive T cells. The contribution of negative selection to the mature T cell repertoire and to autoimmunity is discussed in light of these results.
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