An evaluation of the effects of a service change from epidurals to rectus sheath catheters on postoperative pain.

Epidurals are frequently used as part of multi-modal perioperative analgesia. They are widely accepted as providing excellent pain relief but are associated with side-effects, have a significant failure rate and can limit a patient's mobility. We report on our use of rectus sheath catheters (RSCs), in conjunction with intravenous opiate via patient controlled analgesia (PCA), as a means of providing analgesia post-laparotomy for gynaecological oncological patients. Our experience is that this offers an alternative method of providing equivalent analgesia, avoiding the risks associated with epidural use and possibly has a role in reducing length of patient stay, although this requires further investigation.

Delays in treating endometrial cancer in the South West of England.

BACKGROUND: Poor cancer survival rates in the United Kingdom are often blamed on delayed medical care. A local audit of endometrial cancer revealed a variety of preventable delays. We surveyed practice in the South West of England to see if this was an isolated or widespread problem. METHODS: All 15 hospitals in the South West of England collected information prospectively from all women with endometrial cancer over 3 months in the spring of 2009. RESULTS: There were delays in all stages of the uterine cancer pathway. Excluding extraneous cases, 52% of women waited more than a month and 12% waited more than 6 months to see their GP from the onset of symptoms. Almost half the cases said they were unaware that abnormal bleeding was a symptom of cancer. Only a quarter of women had treatment within 31 days from the outpatient visit to first definitive treatment and 18% waited more than the target of 62 days for their treatment. CONCLUSIONS: Significant treatment delays occur because women do not report bleeding. If this is replicated throughout Britain, approximately 1000 women per year will delay presentation for at least 3 months and 600 will wait for more than 6 months.

Obstetric management following fertility-sparing radical vaginal trachelectomy for cervical cancer.

Radical vaginal trachelectomy now affords a fertility-sparing procedure for the treatment of early-stage cervical cancer in young women. Subsequent obstetric management within this group of women remains a challenge to the obstetrician, with risks of premature labour a continuing probability throughout pregnancy. Here we describe four cases of successful pregnancy following radical vaginal trachelectomy within our unit. The merits of early antenatal intervention, regular lower uterine segment length monitoring and use of daily progesterone pessaries are discussed, alongside the current supportive evidence. We conclude with a discussion of proposed recommendations for obstetric management of pregnancy in women post-radical vaginal trachelectomy.

A systematic review of the accuracy of diagnostic tests for inguinal lymph node status in vulvar cancer.

OBJECTIVE: To determine the accuracy of minimally and non-invasive tests to assess the groin node status in squamous cell vulvar cancer. METHODS: A systematic review of published research from 1979 to 2004 that compares the results of tests to determine groin node status with histology at inguinofemoral lymphadenectomy was made. Studies included in the review were those that compared the index test to the standard surgical intervention of inguinofemoral lymphadenectomy and allowed the construction of two-by-two tables. From these tables, sensitivity, specificity, and the likelihood ratios (with 95% confidence intervals) were reported and, where feasible, meta-analysis was used to pool results for each test separately. Sentinel node biopsy using technetium-99m-labelled nanocolloid ((99m)Tc) had a pooled sensitivity and negative LR of 97% (91-100 95% CI) and 0.12 (0.053-0.28 95% CI), respectively, and was the most accurate test reviewed. CONCLUSION: Five diagnostic tests were identified in a total of 29 studies (961 groins). Although the studies were small and the design often poor, this represents the best summary of the data to date. Sentinel node identification using (99m)Tc appeared to be the most promising test for accurately excluding lymph node metastases in squamous cell vulvar cancer and potentially reducing the radicality of surgery. Its efficacy as a tool in reducing the need for radical surgery and associated patient morbidity without reducing survival needs further assessment probably in a randomised control trial.

Folic acid targeting of protein conjugates into ascites tumour cells from ovarian cancer patients.

Despite a wealth of in vitro data describing the use of folic acid for drug and DNA delivery into ovarian cancer cell lines, there have been no reports describing the targeting of such compounds to freshly isolated tumour cells. We have carried out a study to determine the usefulness of folic acid as a targeting ligand for ovarian cancer by measuring the uptake of folic acid-BSA-FITC in tumour cells isolated from the ascitic fluid of ovarian cancer patients. In 7 out of 7 patients we have found folic acid mediated uptake of the fluorescently labelled albumin, with the accumulation (average cell fluorescence) and differential uptake (ratio between receptor mediated and fluid phase uptake) varying between patients. Accumulation of folic acid-albumin FITC occurs in ascites tumour cells expressing the epithelial cell marker EMA, with a significant proportion of EMA negative cells also accumulating the conjugate. There is no correlation between cell cycle and uptake of folic acid-BSA-FITC. These results suggest that folic acid-targeting of therapeutics is a promising approach for the treatment of ovarian cancer.

Enhanced binding to origin DNA at low pH enables easy detection of polyomavirus large T antigen by gel mobility shift assay of unfixed complexes.

Enhanced, stable binding by polyomavirus large T antigen to the viral DNA replication origin at pH 6 allowed the development of a gel mobility shift assay for the detection of large T antigen. Such assays were not possible at pH 7.6 without previous fixation, due to instability of the complexes. We demonstrated that the gel mobility shift assay at pH 6 is very sensitive, allowing the detection of as little as 5 ng large T antigen, and is highly specific for DNA containing G(A/G)GGC target sequences. This method was used to detect large T antigen in crude cell lysates from transformed yeast cell lines or nuclear extracts from infected insect cells. Large T antigen-DNA complexes remained at or near the loading well in 5% acrylamide or 1.5% agarose gels, indicating that these complexes are very large. Glycerol gradient analysis showed that protein-DNA complexes formed at pH 6 were massive, and that large T antigen also formed large complexes when incubated at low pH in the absence of DNA. These results show that pH has a major effect on binding of large T antigen to its multiple target sites in the viral origin of DNA replication, presumably by affecting protein-protein interactions that are important for the stability of large T antigen-DNA complexes.

Polyomavirus large T antigen binds cooperatively to its multiple binding sites in the viral origin of DNA replication.

Polyomavirus large T antigen binds to multiple 5'-G(A/G)GGC-3' pentanucleotide sequences in sites 1/2, A, B, and C within and adjacent to the origin of viral DNA replication on the polyomavirus genome. We asked whether the binding of large T antigen to one of these sites could influence binding to other sites. We discovered that binding to origin DNA is substantially stronger at pH 6 to 7 than at pH 7.4 to 7.8, a range often used in DNA binding assays. Large T antigen-DNA complexes formed at pH 6 to 7 were stable, but a fraction of these complexes dissociated at pH 7.6 and above upon dilution or during electrophoresis. Increased binding at low pH is therefore due at least in part to increased stability of protein-DNA complexes, and binding at higher pH values is reversible. Binding to fragments of origin DNA in which one or more sites were deleted or inactivated by point mutations was measured by nitrocellulose filter binding and DNase I footprinting. The results showed that large T antigen binds cooperatively to its four binding sites in viral DNA, suggesting that the binding of this protein to one of these sites stabilizes its binding to other sites via protein-protein contacts. Sites A, B, and C may therefore augment DNA replication by facilitating the binding of large T antigen to site 1/2 at the replication origin. ATP stabilized large T antigen-DNA complexes against dissociation in the presence, but not the absence, of site 1/2, and ATP specifically enhanced protection against DNase I digestion in the central 10 to 12 bp of site 1/2, at which hexamers are believed to form and begin unwinding DNA. We propose that large T antigen molecules bound to these multiple sites on origin DNA interact with each other to form a compact protein-DNA complex and, furthermore, that ATP stimulates their assembly into hexamers at site 1/2 by a "handover" mechanism mediated by these protein-protein contacts.

A conserved cysteine residue in yeast uroporphyrinogen decarboxylase is not essential for enzymatic activity.

Uroporphyrinogen decarboxylase catalyzes the fifth step of heme biosynthesis in Saccharomyces cerevisiae. Studies utilizing sulfhydryl-specific reagents suggest that the enzyme requires a cysteine residue within the catalytic site. This hypothesis was tested directly by site-directed mutagenesis of highly conserved cysteine-52 to serine or alanine. Plasmids containing these mutations were able to complement a hem6 mutant strain. In addition, properties associated with decreased uroporphyrinogen decarboxylase activity were not detected in the mutant strain transformed with these mutant plasmids. These results suggest that the conserved cysteine-52 by itself is not essential for enzymatic activity.

Production of active polyomavirus large T antigen in yeast Pichia pastoris.

The coding region of polyomavirus large T antigen was engineered into the genome of the methylotrophic yeast Pichia pastoris by use of the vector pHIL-D2. Expression of large T antigen was induced by methanol under the control of the strong alcohol oxidase (AOX1) promoter. Large T antigen was purified by immunoaffinity chromatography. We showed that yeast-derived large T antigen bound specifically to a DNA fragment that contains the polyomavirus replication origin, protected the four known major binding sites in the origin against DNase I digestion, and could unwind the strands of an origin-containing DNA fragment in an ATP-dependent manner. This system therefore provides a convenient and inexpensive source of biologically active polyomavirus large T antigen for in vitro studies.

Novel exonic elements that modulate splicing of the human fibronectin EDA exon.

Three exons in the fibronectin primary transcript are alternatively spliced in a tissue- and developmental stage-specific manner. One of these exons, EDA, has been shown previously by others to contain two splicing regulatory elements between 155 and 180 nucleotides downstream of the 3'-splice site: an exon splicing enhancer and a negative element. By transient expression of a chimeric beta-globin/fibronectin EDA intron in COS-7 cells, we have identified two additional exonic splicing regulatory elements. RNA generated by a construct containing the first 120 nucleotides of the fibronectin EDA exon was spliced with an efficiency of approximately 50%. Deletion of most of the fibronectin EDA exon sequences resulted in a 20-fold increase in the amount of spliced RNA, indicative of an exon splicing silencer. Deletion and mutagenesis studies suggest that the fibronectin exon splicing silencer is associated with a conserved RNA secondary structure. In addition, sequences between nucleotides 93 and 118 of the EDA exon contain a non-purine-rich splicing enhancer as demonstrated by its ability to function in a heterologous context.

The HMG domain of the ROX1 protein mediates repression of HEM13 through overlapping DNA binding and oligomerization functions.

The ROX1 gene of Saccharomyces cerevisiae encodes a protein required for the repression of genes expressed under anaerobic conditions. ROX1 belongs to a family of DNA binding proteins which contain the high mobility group motif (HMG domain). To ascertain whether the HMG domain of ROX1 is required for specific DNA binding we synthesized a series of ROX1 protein derivatives, either in vitro or in Escherichia coli as fusions to glutathione S-transferase (GST) protein, and tested them for their ability to bind to DNA. Both ROX1 proteins that were synthesized in vitro and GST-ROX1 fusion proteins containing the intact HMG domain were able to bind to specific target DNA sequences. In contrast, ROX1 proteins which contained deletions within the HMG domain were no longer capable of binding to DNA. The oligomerization of ROX1 in vitro was demonstrated using affinity-purified GST-ROXI protein and ROX1 labelled with [35S]methionine. Using various ROX1 protein derivatives we were able to demonstrate that the domain required for ROX1-ROX1 interaction resides within the N-terminal 100 amino acids which constitute the HMG domain. Therefore, the HMG domain is required for both DNA binding activity and oligomerization of ROX1.

RNA footprint mapping of RNA polymerase II molecules stalled in the intergenic region of polyomavirus DNA.

RNA polymerase II molecules that transcribe the late strand of the 5.3-kb circular polyomavirus genome stall just upstream of the DNA replication origin, in a region containing multiple binding sites for polyomavirus large T antigen. Stalling of RNA polymerases depends on the presence of functional large T antigen and on the integrity of large T antigen binding site A. To gain insight into the interaction between DNA-bound large T antigen and RNA polymerase II, we mapped the position of stalled RNA polymerases by analyzing nascent RNA chains associated with these polymerases. Elongation of RNA in vitro, followed by hybridization with a nested set of DNA fragments extending progressively farther into the stalling region, allowed localization of the 3' end of the nascent RNA to a position 5 to 10 nucleotides upstream of binding site A. Ribonuclease treatment of nascent RNAs on viral transcription complexes, followed by in vitro elongation and hybridization, allowed localization of the distal end of stalled RNA polymerases to a position 40 nucleotides upstream of binding site A. This RNA footprint shows that elongating RNA polymerases stall at a site very close to the position of DNA-bound large T antigen and that they protect approximately 30 nucleotides of nascent RNA against ribonuclease digestion.

The role of microscopy in the diagnosis of sexually transmitted infections in women.

INTRODUCTION: Microscopy of genital secretions is routinely performed in female patients attending genitourinary medicine clinics. It diagnoses only 50-70% of gonorrhoea, 40-80% of trichomoniasis and has no value in the diagnosis of chlamydial infection. This study was therefore conducted to reassess the role of routine microscopy in female patients. SUBJECTS AND METHODS: One thousand consecutive women attending the genitourinary medicine clinic of the General Hospital, Birmingham, were studied prospectively. The first 500 women had routine microscopy performed. The second 500 women had microscopy performed only if they complained of symptoms, were known gonorrhoea contacts, or when an abnormal vaginal discharge was noted by the examining clinician. RESULTS: In the routine microscopy group, 46 (9.2%) women had gonorrhea; 30 of these were diagnosed by microscopy and subsequently confirmed on culture and 16 by culture alone; of these, two (4.3%) defaulted from follow-up and were not treated. In the selective microscopy group 139 women (28%) did not require microscopy. Thirty three women had positive culture for Neisseria gonorrhoeae. Of these, seven were diagnosed by microscopy, the rest by culture alone. All patients were successfully treated. No patients with trichomoniasis in the routine microscopy group and only two (4.3%) in the selective microscopy group were lost to follow-up. CONCLUSION: In this study, the selective policy in the second group led to a significant reduction in microscopy. Such a policy has the benefits of saving time for patients and staff, more efficient utilisation of manpower and resources. It did not lead to any significant delay in the diagnosis and treatment of patients with sexually transmitted infections.

Mutation of large T-antigen-binding site A, but not site B or C, eliminates stalling by RNA polymerase II in the intergenic region of polyomavirus DNA.

During transcription of the late strand of polyomavirus DNA, RNA polymerase II stalls and accumulates nearby the binding sites on viral DNA recognized by polyomavirus large T antigen. Stalling by RNA polymerases is eliminated when thermolabile large T antigen is inactivated by using a temperature-sensitive virus mutant (J. Bertin, N.-A. Sunstrom, P. Jain, and N. H. Acheson, Virology 189:715-724, 1992). To determine whether stalling by RNA polymerases is mediated through the interaction of large T antigen with one or more of its binding sites, viable polyomavirus mutants that contain altered large-T-antigen-binding sites were constructed. Point mutations were introduced by site-directed mutagenesis into the multiple, clustered G(A/G)GGC pentanucleotides known to be the target sequence for large T-antigen binding. Mutation of the G(A/G)GGC pentanucleotides in the first two binding sites encountered by RNA polymerases in the intergenic region (sites C and B) had no detectable effect on stalling as measured by transcriptional run-on analysis. However, mutation of the two GAGGC pentanucleotides in binding site A, which lies adjacent to the origin of viral DNA replication, eliminated stalling by RNA polymerases. We conclude that binding of large T antigen to site A blocks elongation by RNA polymerase II. Further characterization of virus containing mutated site A did not reveal any effects on early transcription levels or on virus DNA replication. However, the mutant virus gave rise to small plaques, suggesting impairment in some stage of virus growth. Stalling of RNA polymerases by large T antigen bound to the intergenic region of viral DNA may function to prevent transcription from displacing proteins whose binding is required for the normal growth of polyomavirus.

Stalling by RNA polymerase II in the polyomavirus intergenic region is dependent on functional large T antigen.

RNA polymerase II encounters an elongation block and stalls in vivo during transcription of the late strand of polyomavirus DNA. In this study, we performed transcriptional run-on assays and localized the stalling site to a 164-nucleotide region (nt 11-175) that contains specific binding sites for polyomavirus large T antigen. The effect of large T antigen on elongation by RNA polymerase II through this region was examined in cells infected with a mutant polyomavirus (AT3-ts25E) which encodes a thermolabile large T antigen. Removal of functional large T antigen by shifting to the nonpermissive temperature (39 degrees) eliminated stalling by RNA polymerase in this region, although RNA polymerases transcribing other regions of the viral genome were unaffected. RNA polymerase resumed stalling when functional large T antigen was again allowed to accumulate by shifting back to the permissive temperature (32 degrees). We conclude that stalling by RNA polymerase II in vivo is dependent on the presence of functional large T antigen.

Determination of the origin-specific DNA-binding domain of polyomavirus large T antigen.

To map the DNA-binding domain of polyomavirus large T antigen, we constructed a set of plasmids coding for unidirectional carboxy- or amino-terminal deletion mutations in the large T antigen. Analysis of origin-specific DNA binding by mutant proteins expressed in Cos-1 cells revealed that the C-terminal boundary of the DNA-binding domain is at or near Glu-398. Fusion proteins of large T antigen lacking the first 200 N-terminal amino acids bound specifically to polyomavirus origin DNA; however, deletions beyond this site resulted in unstable proteins which could not be tested for DNA binding. Testing of point mutants and internal deletions by others suggested that the N-terminal boundary of the DNA-binding domain lies between amino acids 282 and 286. Taken together, these results locate the DNA-binding domain of polyomavirus large T antigen to the 116-amino-acid region between residues 282 and 398.