Guest Lecture 9.45–10.30 Wednesday 17 September 2003. Csp Colposcopy Guidelines

The success of the Cervical Screening Programme (CSP) is due in part to its management being underpinned by Quality Assurance. These measures ensure uniform standards across the country. Since 1992 Colposcopy Guidelines have been in place; these were updated in 1997 and have just been redefined. It is entirely consistent with the National CSP that colposcopy is governed by Guidelines. The aim of clinical practice guidelines is to raise the standard of care and improve outcomes. The objectives are, therefore:

• a) to develop evidence based guidelines;
• b) to ensure the guidelines are widely adopted.

The credibility of guidelines is crucial to their adoption and this depends far more on the demonstration of an evidence base than that the authors are ‘experts’. Development by a professional group or body who are seen as having a legitimate role is very important as is involvement of all ‘stakeholders’ in ensuring acceptability. In terms of their nature, guidelines should be valid i.e. they will achieve what they are intended to achieve, and they should be robust i.e. they will work when implemented by different individuals in different settings. Colposcopy lends itself well to guidelines because it is largely a routine practice, but substandard care can have serious consequences. In previous years there has been a set of Guidelines for Practice ^1, 1Duncan 1992 ² 2Duncan 1995 and a set of Quality Standards ³ 3Luesley 1996 . On this occasion these two components have been put together in a simple publication. It needs to be borne in mine that the new guidelines were being developed in the context of a number of potential changes which could interact with each other and impact on the Guidelines. These include: The process for the development of the Guidelines included an Editor, an editorial group, and a group of contributors to produce a draft set of evidence based guidelines across 18 areas. New areas covered included HIV +ve women, immuno suppressed women, and working practice. The draft has been available for comment for several months and amendments have been made. Clearly there are areas where evidence is lacking and where different views are expressed. The most contentious area not surprisingly is in the topic of managing mild dyskaryosis; controversy in this has persisted for many years. The quality standards are either attainable or within attainment and are a driver for rising standards. These programme practice guidelines and standards have earned UK colposcopy international respect. They provide a benchmark for QA assessment and will continue to require amendment as new developments come into being.     

KINETICS OF [3H]ACETYLCHOLINE SYNTHESIS AND RELEASE IN PRIMARY CELL CULTURES FROM MAMMALIAN CNS

Abstract— The present study was undertaken to characterize the cholinergic system of primary cell cultures of mouse and rat CNS.
In confirmation of previous reports, primary cultures were found to contain choline acetyltransferase (ChAc). Furthermore they contain acetylcholine (ACh) as measured by two different bioassays. They also synthesize [³H]ACh from [³H]Choline offered to the cultures.
The formation of [³H]ACh is inhibited in the presence of hemicholinium-3 (10⁻⁶ m ) to 50% or ouabain (10⁻³ m ) to 20% of the values found in untreated cultures. Omission of Na ⁺ from the incubation solution also diminishes the [³H]ACh formation of the cells.
[³H]ACh is released upon depolarisation by K⁺ ions in a concentration dependent manner. The release can be prevented by lack of Ca²⁺ ions in the incubation solution.     

Fast locomotion of some African ungulates

Ten species of ungulate were filmed, galloping in their natural habitat. They ranged in size from Thomson's gazelle (about 20 kg) to giraffe (about 1000 kg). They were pursued to make them run as fast as possible. The films have been analysed to determine speed, stride frequency, stride and step lengths, and duty factors. The dependence of these quantities on body size is discussed.  

Summary:

Fast locomotion of zebra, giraffe, warthog and seven species of Bovidae has been studied. The animals were filmed from a pursuing vehicle while galloping in their natural habitat.
Stride frequency was more closely correlated with limb length (represented by hip height) than with body mass. Mean stride frequency was proportional to (hip height)^-0·51 and maximum stride frequency to (hip height) ^-0·63.
Maximum speed was between 10 and 14 m s ^-1 for all species except buffalo (7 m s ^-1). It was not significantly correlated with body mass.
Since the small species ran at least as fast as the large ones they attained higher Froude numbers. Relative stride length was approximately 1·8 (Froude number)^0·39 for all species, irrespective of size. Relative step length was approximately 0·65 (Froude number)^0·2, both for the fore feet and for the hind ones. The vertical forces exerted by the feet are proportional to (body weight)×(Froude number)^0·2 so the forces at maximum speed are larger multiples of body weight for small species than for large ones.     

Cadmium dynamics in fish: pulse studies with 109Cd in female zebrafish, Brachydanio rerio

The dynamics of a subtoxic pulse of non-dietary ¹⁰⁹Cd was followed for up to 304 days after the exposure period in female zebrafish. The retention of dietary ¹⁰⁹Cd was also estimated.
The distribution of ¹⁰⁹Cd was studied by autoradiography, whole-body analysis and tissue sampling. After exposure to non-dietary ¹⁰⁹Cd for 10 days there was a rapid loss of ¹⁰⁹Cd from the gills. The ¹⁰⁹Cd content of the alimentary canal exceeded that which could have been expected from normal drinking. Based on the distribution pattern of non-dietary ¹⁰⁹Cd in tissues, two groups of tissues were distinguished:

• (i)

  the gills, alimentary canal and heart which showed maximum ¹⁰⁹Cd values directly after exposure, followed by a pronounced decrease up to day 21;
• (ii)

  the liver, kidney, ovary and muscle, in which there was a delay in maximum ¹⁰⁹Cd activity to days 21–42, with subsequent loss.

Small amounts of ¹⁰⁹Cd were noted in fry and fertilized eggs originating from zebrafish exposed to non-dietary ¹⁰⁹Cd. After exposure to dietary ¹⁰⁹Cd, less than 5% was retained in the zebrafish body, mainly in the alimentary canal.     

En, Eo - further new factors in the complex E blood group system of the pig

Two new erythrocyte antigens have been detected by isoimmune antibodies obtained from Gottingen Miniature pigs. By family studies they proved to belong to the E system. The factor designated En is genetically controlled by alleles E ²= E ^edghkmn, E ³= E ^aegln, E ⁴= E ^edfhkmn, E ⁶= E ^aefln, E ⁹= E ^edghjmn, E ¹²= E ^aegmno and E ^edgkln, and the factor designated Eo by the allele E ¹²= E ^aegmno.
The En blood factor occurs in all the breeds studied and in frequency it comes close to a related Ee factor. It stands in opposition not only to Eb but also to Ei factor. The Eo factor can be characterized as a rarely occurring Ea subgroup. Besides being antithetic to Ed it is also antithetic to El and Ei factors. For the present, it was found only in Miniature pigs.     

Personal commentaryExternal quality assessment (EQA) in gynaecological cytology: radical rethinking required?

Accepted for publication 19 February 1999
THE PAST
The value of EQA in pathology, including proficiency testing in gynaecological cytology, has been the subject of much recent lively debate^1–6. In summary, the proven role of EQA in the monitoring of personal performance and ability is still uncertain. Furthermore, its potential to prevent critical incidents remains purely speculative. Also, whether EQA would be better replaced, for some or all professional groups, by other methods of quality assurance is unknown. Similarly, whether EQA can justify the considerable professional time, effort and expense involved has not been resolved.  

THE PRESENT

Not surprisingly, events at Kent & Canterbury Hospitals abruptly halted much of the debate about the foregoing issues⁷. Indeed, as a direct consequence of this and other incidents, the NHS Executive stipulated unilaterally that EQA is now mandatory within the NHS Cervical Screening Programme (CSP)⁸ and reinforced the necessity for all qualified laboratory staff to participate^8–10. A surprise, however, was the Executive's enlightened comments on EQA. First, and of greatest significance, that the principal function of EQA in pathology is to improve standards and advance quality through personal education. Second, that EQA should be seen to complement other QA systems for the early identification of potential problems which might affect patient care. Third, that the identification of individual poor performance through EQA will be exceptional and in essence is a by-product of the basic educational exercise. The latter conclusion was drawn, as far as one can judge, from previous experience with the NHS Breast Screening Programme (NHSBSP) EQA.  

THE FUTURE—PERSONAL SUGGESTIONS FOR OPEN DEBATE

     

AUTORADIOGRAPHIC DETECTION OF DNA POLYMERASE CONTAINING NUCLEI IN SARCOMA 180 ASCITES CELLS

A technique has been developed allowing the autoradiographic detection of incorporation of ³H-thymidine-5'-triphosphate (³H-TTP) into nuclear DNA of smears of Sarcoma-180 (S-180) mouse ascites tumors under the direction of the cell's own nuclear DNA polymerase. Dried smears are dipped into an agar solution, which strips cytoplasm from the nuclei, and are then air dried and incubated with a buffered mixture containing four nucleotide triphosphates (one labeled), Mg⁺⁺, and Ficoll, with the cell's own DNA acting as primer. The incorporation of ³H-TTP into the nuclei, like the cell free DNA polymerase assay, is largely dependent on the presence of all four nucleotide triphosphates and Mg⁺⁺ and produces a product which is DNase sensitive and RNase resistant.
DNA polymerase activity, as studied in a cell free assay, decreases with tumor age. This correlates well with a decreasing ³H-TTP labeling index in autoradiographs of aging tumors. The ³H-TTP labeling index has also been shown to exceed but parallel the in vivo ³H-thymidine (³H-TdR) pulse labeling index for all tumor ages examined.
In at least some cell systems DNA polymerase seems characteristic of cells in cycle. The autoradiographic detection of nuclei containing the enzyme offers a new tool for the study of tumor cytokinetics.     

An SNP in the goat CSN2 promoter region is associated with the absence of beta-casein in milk

So far, at least eight alleles in the goat CSN2 locus have been associated with the level of β -casein expression in milk. Alleles CSN2 ^A , CSN2 ^{A 1}, CSN2 ^B , CSN2 ^C , CSN2 ^D and CSN2 ^E have been associated with normal content (allele effects of about 5 g of β -casein per litre), whereas the CSN2 ⁰ and CSN2 ⁰¹ alleles have been associated with non-detectable levels of β -casein. Most of these alleles have been characterized genetically. Herein, we report the identification of a previously unreported SNP in the goat CSN2 promoter region ( AJ011018 :g.1311T>C), which is associated with the absence of β -casein in the milk. Furthermore, we developed a PCR-based method that allows detection of this mutation.     

Interaction between superantigen and T-cell receptor Vβ element determines levels of superantigen-dependent cell-mediated cytotoxicity of CD8+ T cells in induction and effector phases

Specific superantigens activate different T-cell fractions with distinct TCR Vβ elements in association with MHC class II molecules and also induce SDCC against MHC class II⁺ target cells. In the present study, to determine whether the responsiveness of each CD8⁺ T-cell fraction expressing a different TCR Vβ element is primarily determined by the TCR Vβ, we compared the levels of proliferation and SDCC in Vβ3⁺ and Vβ11⁺ T cells upon stimulation with SEA. Upon stimulation with SEA_wt, the levels of proliferation were higher in Vβ3⁺ T cells than in Vβ11⁺ T cells. The levels of SDCC were also higher for the combination of Vβ3⁺ T cells and SEA_wt than for the combination of Vβ11⁺ T cells and SEA_wt during both the induction phase and the effector phase. In addition, upon stimulation with SEA_m, the levels of proliferation were higher in Vβ11⁺ T cells than in Vβ3⁺ T cells. And then, the levels of SDCC were also higher for the combination of Vβ11⁺ T cells and SEA_m than for the combination of Vβ3⁺ T cells and SEA_m during both the induction phase and the effector phase. These results suggest that the SAG-responsiveness of each CD8⁺ T-cell fraction expressing a different TCR Vβ element is primarily determined by the interaction between the TCR Vβ element and the SAG.     

Influence of woodlot floor topography on microbial decomposer distribution

The distribution of microbial populations that decomposed sugar, cellulose and lignin-related substrates was examined in a beech Fagus grandifolia Ehrh. and maple Acer saccharum Marsh. dominated woodlot developed on glacial till. The topography of the woodlot, characterized by rises, depressions and more extensive level areas about 1 m in diameter with a 0.5 m vertical maximum, produced a mosaic of decomposer habitats designated as high, level and low sites.
In general, populations of sugar, cellulose and lignin decomposing organisms (based on ten estimates made from April to October) were two to four times higher in litter and soil samples from low sites than those from high sites. Sugar decomposing bacteria in litter were most abundant at all topographic sites. 135 × 10⁶ g⁻¹ dry litter at high sites, 396 × 10⁶ g⁻¹ at level sites and 456 × 10⁶ g⁻¹ at low sites; lignolytic fungi were least abundant, 391 × 10² g⁻¹ dry litter at high sites. 700 × 10⁶ g⁻¹ at level sites and 954 × 10² g⁻¹ at low sites. Numbers of microbial decomposers in the topographic sites were correlated with organic matter content. Distribution of fungal genera did not appear to be related to topographic site. Most populations examined showed two numerical peaks, one in late May or June and one in late September or October. It is suspected that these peaks were influenced by the coincident timing of favourable physical conditions and priming by soluble nutrients leached from litter.     

Heat shock regulation in the ftsH null mutant of Escherichia coli: dissection of stability and activity control mechanisms of σ32in vivo

The heat shock response of Escherichia coli is regulated by the cellular level and the activity of σ³², an alternative sigma factor for heat shock promoters. FtsH, a membrane-bound AAA-type metalloprotease, degrades σ³² and has a central role in the control of the σ³² level. The ftsH null mutant was isolated, and establishment of the Δ ftsH mutant allowed us to investigate control mechanisms of the stability and the activity of σ³² separately in vivo . Loss of the FtsH function caused marked stabilization and consequent accumulation of σ³² (≈20-fold of the wild type), leading to the impaired downregulation of the level of σ³². Surprisingly, however, Δ ftsH cells express heat shock proteins only two- to threefold higher than wild-type cells, and they also show almost normal heat shock response upon temperature upshift. These results indicate the presence of a control mechanism that downregulates the activity of σ³² when it is accumulated. Overproduction of DnaK/J reduces the activity of σ³² in Δ ftsH cells without any detectable changes in the level of σ³², indicating that the DnaK chaperone system is responsible for the activity control of σ³² in vivo . In addition, CbpA, an analogue of DnaJ, was demonstrated to have overlapping functions with DnaJ in both the activity and the stability control of σ³².     

Genotyping bovine milk proteins using allele discrimination by primer length and automated DNA sizing technology

A method for genotyping K-casein ( A, B, E ), β-casein ( A ¹, A ², A ³, A⁵, B ) and β-lactoglobulin ( A, B ) simultaneously by the use of allele discrimination by primer length combined with automated detection of fragments with a sequencing instrument is described. Seven different mutations within the milk protein genes were analysed in order to distinguish between the alleles examined. The samples were amplified in two separate multiplex polymerase chain reactions (PCRs), which were then pooled and separated according to size in a single lane on the gel. By using stringent PCR conditions, we have been able to achieve allele-specific amplifications and minimize amplification of mismatched primer for all seven mutations.     

PHYSIOLOGICAL RACES OF PHYTOPHTHORA INFESTANS: A COMPARISON OF THE DIFFERENTIAL HOSTS AT THE PLANT BREEDING INSTITUTE, CAMBRIDGE, WITH THOSE OF THE SCOTTISH SOCIETY FOR RESEARCH IN PLANT BREEDING

At the Plant Breeding Institute, Cambridge, there have been recognized three physiological races of blight ( Phytophthora infestans ), A, B and C ; and at the Scottish Society for Research in Plant Breeding, Edinburgh, there have been used five races, A, B ¹, B ², C and D , obtained in the British Isles.
It is shown that the two Cambridge types of differential hosts, AbC and ABc (where A = resistant to race A, a = susceptible to race A , etc.), are Ab ¹ b ² CD and AB ¹ B ² cD respectively on the Scottish scheme, and that the Cambridge races A, B and C correspond to the Scottish races A, B ¹ and C respectively.
A number of blight isolates were tested on both the Cambridge and Scottish differential hosts. Isolates of race types A, B ¹, B ¹, C and D were found.
The identification and origin of physiological races of blight, and the breeding of blight-resistant potatoes, are discussed.     

Biomass, productivity and relative rate of photosynthesis of Sphagnum at different water levels on a South Swedish peat bog

The distribution pattern of Sphagnum species on bogs follows a hummock-hollow gradient. S . Sect. Acutifolia (that is in this study S. fuscum and S. rubellum combined) dominates hummock tops, ca 20 cm above the maximum water level with a green biomass of 50 g m⁻², S. magellancium dominates at a lower level, about 5 cm above the water level with a green biomass of 75 g m⁻² and S. cuspidatum dominates in the wettest hollows with a green biomass of about 50 g m⁻².
In situ measurements of length growth of S . Sect. Acutifolia and S. magellanicum using a ¹⁴CO₂-labelling technique during three consecutive years, revealed an unexpectedly high between-year variation in length growth of 7-23 mm yr⁻¹, and 16-22 mm yr⁻¹, respectively. Consequently the dominating producer in the transition between hummock and hollow changes from year to year, probably depending on climatic conditions.
In vitro experiments on the effects of different water levels of 2, 5, 10 and 20 cm below the moss surface, on photosynthetic activity of S . Sect. Acutifolia and S. magellanicum , measured by a second ¹⁴CO₂-technique, indicate optimal conditions for S. magellanicum at 10 cm above water level, and for S . Sect, Acutifolia at 20 cm above water level.
Differences in capillary water transport capability between the species are more important than the sensitivity of photosynthesis to water stress in explaining field patterns of productivity and distribution.     

THE γ SUBUNITS OF PHYCOERYTHRIN FROM A RED ALGA: POSITION IN PHYCOBILISOMES AND SEQUENCE CHARACTERIZATION

Aglaothamnion neglectum Feldman-Mazoyer has two γ subunits, γ³¹ and γ³³, that are associated with phycoerythrin in the light-harvesting phycobilisomes. We demonstrate that these subunits are spatially separated within the phycobilisome, with the γ³¹ subunit present at the distal end of phycobilisome rods and the γ³³ subunit present on the proximal end. These subunits are thought to link phycoerythrin hexamers together in the rod substructure, serving a role analogous to that of linker polypeptides of cyanobacteria (although unlike the cyanobacterial linker polypeptides they are chromophorylated). The sequencing of tryptic polypeptides of the γ subunits enabled us to prepare oligonucleotides encoding different regions of γ³¹. These oligonucleotides were used as primers to generate a probe for isolating a γ³¹ cDNA clone. Characterization of the cDNA clone predicts a polypeptide of 280 amino acids with a 42 amino acid presequence that is characteristic of a transit peptide, the peptide that targets proteins to chloroplasts of vascular plants. The γ³¹ subunit has 50% similarity to the previously characterized γ³³ subunit but has no identifiable similarity to functionally related polypeptides present in cyanobacterial phycobilisomes or to any other polypeptides in the databases. A repeat of 95 amino acids is present in the red algal γ subunit sequences, suggesting that these proteins were generated by a gene duplication followed by fusion of the duplicate sequences.     

In vitro and in vivo regulation of chloroplast glyceraldehydes-3-phosphate dehydrogenase isozymes from Chenopodium rubrum. I. Purification and properties of isozymes

Chloroplast glyceraldehyde-3-phosphate dehydrogenase (GPD, EC 1.2.1.13) was purified from leaves of Chenopodium rubrum L. Aggregated (≥ 10⁶) and disaggregated (165 × 10³) molecular weight forms were obtained by gel filtration in the presence of NAD⁺ and NADP⁺, respectively. The disaggregated enzyme was separated into two isozymes by inverse ammonium sulphate gradient solubilization: "NADP-GPD I" was homotetrameric (subunit molecular weight 39 × 10³); "NADP-GPD II" was heterotetrameric (subunit molecular weights 39 × 10³ and 43 × 10³). Isoelectric focusing of the isozymes, both aggregated and disaggregated, revealed two isoelectric forms in each case, at 4.3 and 7.7. Chloroplast GPD was "NADP-suppressed" in crude extracts due to partial oxidation, incubation with dithioerythritol restored full activity.