Association of human papillomavirus with squamous carcinoma of the uterine cervix

The frequent association of human papillomavirus infection with preinvasive and invasive cancers of the cervix has led to speculation that the viruses may be involved in the neoplastic process. We have carried out some epidemiological studies of the prevalence of human papillomavirus infection in the female genital tract to evaluate more fully the oncogenic potential of these viruses in the cervix. A non-invasive method of detecting the virus has been developed for this purpose using DNA hybridization of cervical scrapings. The technique has been used to carry out prospective studies of patients with cervical intraepithelial neoplasia (CIN) and to investigate infection in women treated by laser therapy for CIN. We have also studied women with normal cervices to determine the prevalence of human papillomaviruses in the normal population. Further studies have involved the investigation of the effect of interferon on virus replication and epithelial proliferation in women with CIN III.

Survey of the implementation of the recommendations in the Health Services Circular 1998/224 'Better Blood Transfusion'

This report describes a questionnaire survey on the implementation of the recommendations of the Health Services Circular (HSC) 'Better Blood Transfusion' 1998/224 for improving transfusion practice. The survey was carried out to inform a second UK Chief Medical Officers' symposium on 'Better Blood Transfusion' in October 2001. Sixty-nine percent of hospitals where blood is transfused in England participated. The results show that, by 2001, most hospitals had established Hospital Transfusion Committees (HTCs), developed protocols for the process of transfusion and were participating in the Serious Hazards of Transfusion (SHOT) scheme. However, there was limited compliance with other recommendations, including the provision of training for staff involved in transfusion and information to patients, the development of protocols for the appropriate use of blood, the performance of audits of transfusion practice and the introduction of peri-operative cell salvage. The survey did not determine the reasons for this limited compliance. New initiatives including the issue of a further HSC on 'Better Blood Transfusion' are aimed at enabling hospitals to improve their transfusion practice in a more systematic way than that was found in the results of this survey.

The impact of improved safety on maintaining a sufficient blood supply

The impact of improved safety on maintaining a sufficient blood supply is becoming an increasingly real issue facing the National Blood Service in England and North Wales. This paper shows the extent of the impact that safety measures can have on reducing collection levels, without making any value judgement on the safety critera themselves. It demonstrates that underlying trends in collection are making it increasingly difficult to meet demand. Further potential restrictions, perhaps associated with variant Creutzfeldt-Jacob disease (vCJD), will require a reassessment of the safety-sufficiency trade-off. The analysis strongly suggests that continual enhancement of safety criteria, for both individual donor and patient benefit, will lead to insufficient supply to meet current levels of hospital demand. New approaches are needed to effectively manage blood throughout the supply chain, thereby ensuring sufficient supply.

Preparation and purification of antisera against different regions or isoforms of beta-amyloid precursor protein

We describe a procedure for the production and peptide affinity purification of polyclonal antisera against synthetic peptides representing different domains of beta-amyloid precursor protein (APP). Rabbits were immunised with keyhole limpet haemocyanin coupled to synthetic peptides representing the amino-terminal APP18-32, Kunitz-type protease inhibitor (KPI) region APP301-316, the A beta region APP670-686, and the carboxy-terminal APP756-770 of APP770 for the production of antisera anti-AP-1, anti-AP-2, anti-AP-4 and anti-AP-5, respectively. Each antiserum was purified to specific antibody using the respective cognate peptides immobilised on affinity columns as ligand, using the 1-ethyl-3-(dimethylaminopropyl)carbodiimide-diaminodipropylamine method. Purified antibodies of these four antisera were highly specific and in enzyme-linked immunosorbent assays (ELISA) reacted only to the corresponding peptide. These purified antisera have been used in Western blot, immunohistochemical and immunoprecipitation techniques to facilitate the understanding of the regulation of APP and amyloid beta-protein (A beta). The A beta is formed by proteolysis of APP, and its deposition leading to the formation of senile plaques in the brain is considered to be a key step in the pathogenesis of Alzheimer's disease.

Cell-specific expression of beta-amyloid precursor protein isoform mRNAs and proteins in neurons and astrocytes

The abnormal accumulation of beta-amyloid (A beta) in senile plaques appears to be a central pathological process in Alzheimer's disease. A beta is formed by proteolysis of beta-amyloid precursor protein (APP) with several isoforms generated by alternative splicing of exons 7, 8 and 15. A semi-quantitative reverse transcription (RT)-polymerase chain reaction (PCR) analysis showed that APP695 mRNA lacking exon 7 and 8 was most abundant in primary cultures of rat neurons, while APP770 and APP751 representing, respectively, the full length and exon 8 lacking isoforms predominated in cultured astroglial cells. Antisera AP-2 and AP-4 were produced by immunizing rabbits with keyhole limpet haemocyanin coupled with synthetic peptides representing KPI region APP301-316 and A beta region APP670-686 of APP770, respectively. These polyclonal antisera were purified against the corresponding peptide using affinity chromatography. Western blot analysis of homogenates of relatively enriched neuronal and astroglial cultures showed that these antibodies discretely stained bands of proteins in a cell-specific manner. Dot-blot analysis using AP-2, AP-4 and 22C11 antibodies indicated that, in comparison with neurons, cultured astrocytes contained 3-fold greater KPI-containing APP isoform proteins. The amount of total APP proteins, which include both KPI-containing and KPI-lacking APP isoforms, was approximately 90% higher in astrocytes than in neurons. Consistent with these in vitro findings in cultured astrocytes, in fimbria-fornix lesioned rat hippocampus, labelling with AP-2 antibody, which specifically reacts with KPI-containing APP proteins, was mainly observed in glial fibrillary acidic protein-positive reactive astrocytes in vivo. The results showed that APP isoforms are expressed in a cell type-specific manner in the brain and, since deposition of A beta is closely associated with the expression of KPI-containing APP isoforms, provide further evidence for the involvement of astrocytes in plaque biogenesis.

Glial cell derived neurotrophic factors and Alzheimer's disease

In Alzheimer's disease the normal balance of metabolic pathways regulating trophic factors/cytokines is disrupted; local reduction may result in neurons being deprived of neurotrophic factors while an excess may initiate a cascade of interaction between glial cells and beta-amyloid precursor protein metabolism thereby facilitating plaque formation. This paper briefly discusses the findings of our group on aspects ranging from cholinergic humoral and trophic factors to mechanisms underlying amyloidogenesis in Alzheimer's disease.

The human cardiac muscle ryanodine receptor-calcium release channel: identification, primary structure and topological analysis

Rapid Ca2+ efflux from intracellular stores during cardiac muscle excitation-contraction coupling is mediated by the ryanodine-sensitive calcium-release channel, a large homotetrameric complex present in the sarcoplasmic reticulum. We report here the identification, primary structure and topological analysis of the ryanodine receptor-calcium release channel from human cardiac muscle (hRyR-2). Consistent with sedimentation and immunoblotting studies on the hRyR-2 protein, sequence analysis of ten overlapping cDNA clones reveals an open reading frame of 14901 nucleotides encoding a protein of 4967 amino acid residues with a predicted molecular mass of 564 569 Da for hRyR-2. In-frame insertions corresponding to eight and ten amino acid residues were found in two of the ten cDNAs isolated, suggesting that novel, alternatively spliced transcripts of the hRyR-2 gene might exist. Six hydrophobic stretches, which are present within the hRyR-2 C-terminal 500 amino acids and are conserved in all RyR sequences, may be involved in forming the transmembrane domain that constitutes the Ca(2+)-conducting pathway, in agreement with competitive ELISA studies with a RyR-2-specific antibody. Sequence alignment of hRyR-2 with other RyR isoforms indicates a high level of overall identity within the RyR family, with the exception of two important regions that exhibit substantial variability. Phylogenetic analysis suggests that the RyR-2 isoform diverged from a single ancestral gene before the RyR-1 and RyR-3 isoforms to form a distinct branch of the RyR family tree.

Expression of a cardiac Ca(2+)-release channel isoform in mammalian brain

Mammalian brain possesses ryanodine-sensitive Ca2+ channels, which in muscle cells mediate rapid Ca2+ release from intracellular stores during excitation-contraction coupling. Analysis of bovine brain ryanodine receptor (RyR) channels suggests specific expression of the cardiac-muscle RyR isoform in mammalian brain. Localization using cardiac-muscle RyR-specific antibodies and antisense RNA revealed that brain RyRs were present in dendrites, cell bodies and terminals of rat forebrain, and highly enriched in the hippocampus. Activity of skeletal-muscle RyR channels is coupled to sarcolemmal voltage sensors, in contrast with cardiac-muscle RyR channels, which are known to be Ca(2+)-induced Ca(2+)-release channels. Thus Ca(2+)-induced Ca2+ release from intracellular stores mediated by brain RyR channels may be a major Ca(2+)-signalling pathway in specific regions of mammalian brain, and hence may play a fundamental role in neuronal Ca2+ homoeostasis.

DNA hybridisation of cervical scrapes: comparison with cytological findings in Papanicolaou smears

One hundred and sixty four cervical scrapes were taken over 26 months from 143 women aged 17 to 53 years, using an Ayre spatula. A smear was prepared from each sample for Papanicolaou staining and for cytological examination for evidence of human papillomavirus (HPV) infection. The cells remaining on the spatula were harvested for DNA analysis. These samples were probed for HPV 6, 16, and 18 and the results of DNA hybridisation and cytology were compared. Cytological changes of HPV (anucleate keratinised and keratinised squamous cells, koilocytic change and dyskeratosis, or multinucleation, or both) were detected in 103 (72%) of the samples where HPV DNA was detected; koilocytic changes were present in only 67 (48%). It is concluded that screening for a range of viral changes is a more sensitive method of detecting HPV infection than screening for koilocytic change alone.

Sexual transmission of human papillomaviruses in heterosexual and male homosexual couples, studied by DNA hybridisation

The prevalence of human papillomavirus (HPV) 6, 11, 16, and 18 in 36 heterosexual couples and seven male homosexual couples with genital warts was investigated for evidence of sexual transmission of genital HPV. The prevalence of virus type and number of copies of viral genome equivalents/cell in the lesions were assessed, and the factors influencing transmission analysed. Our results show that HPV 6 and, to a lesser extent, HPV 11 were the types most readily transmitted, and that transmission appears to depend on the copy number and the duration and frequency of exposure.

Prevalence of HPV DNA and viral copy numbers in cervical scrapes from women with normal and abnormal cervices

Cervical scrapes were obtained from 215 women with cytologically normal cervices and 74 women with cervical intraepithelial neoplasia (CIN) and probed for HPV 6, 11, 16, and 18 by dot-blot hybridization. Viral copy numbers were determined by densitometric scanning of autoradiographs. The prevalence of HPV DNA in women with normal smears was as follows: 23 per cent of women attending a Family Planning Clinic (FPC), 16 per cent of women attending a Sexually Transmitted Diseases (STD) clinic, and 48 per cent of women attending a laser follow-up clinic after treatment of CIN. Ten per cent of women with normal cervices harboured HPV 16. Viral copy numbers ranged from 1300 to 52,800 genome equivalents per cell. Twenty-seven HPV-positive women with normal smears (including four patients infected with HPV 16) were followed for up to 3 years. None developed CIN irrespective of copy number. Our results show that HPV is present in normal cervices in the absence of CIN. Copy number has no relation to the development of CIN and factors other than the amount of HPV DNA may trigger the neoplastic process.

Use of hybridot assay to screen for BK and JC polyomaviruses in non-immunosuppressed patients

Urine samples from 50 patients attending a genitourinary outpatient clinic and from 13 renal allograft recipients were investigated for evidence of infection with human BK and JC polyomaviruses using cytology and a new DNA hybridot assay. Forty four per cent of samples from the renal allograft recipients were positive by cytology and 75% by DNA hybridisation, indicating that hybridot assay is more sensitive than cytological screening. BK and JC viral DNA was found in 20% of the patients attending the genitourinary clinic, showing infection with BK virus and JC virus in a group of patients with clinical conditions not normally associated with immunological deficiency-a finding that has not been reported before.

Cross-hybridisation of human papillomavirus DNA on filters

Accurate type assignment of the different HPV types which infect the female genital tract, is essential in view of the differing pathological potential of the common virus types present in the cervix. We have developed hybridisation, washing and autoradiography conditions that minimise cross-hybridisation on filters and so allow clear-cut type assignment. We describe the conditions in this paper and have used this method to screen for HPV infection in clinical populations.

DNA hybridization of cervical tissues

The increasing frequency of cervical neoplasia among younger women and the increased invasiveness of these tumors has led to a considerable growth in research into this disease. Conventional methods (epidemiology, cytology, and immunology), while being extremely useful, also have significant limitations. Recent advances in techniques for the manipulation of DNA now make it possible to analyze tissues for the presence of viral genomes. This review introduces these techniques and describes their application to the search for herpes simplex virus and human papillomavirus sequences in cervical tissue. The significance of the findings both for the mechanism of transmission of the disease, and also the consequences for early detection and hence more successful treatment, are also discussed.

The effect of interferon on human papillomaviruses associated with cervical intraepithelial neoplasia

A double-blind, placebo-controlled, trial of leucocyte interferon showed that, contrary to previous reports, interferon had no significant effect on cervical intraepithelial neoplasia (CIN) when applied topically in a gel. DNA hybridization of cervical scrapes was used to monitor the effect of interferon on the human papillomaviruses (HPV) associated with CIN. There was, however, no significant difference in the expression of HPV 6 or 16 in the cervical epithelium of patients treated with interferon compared with those given a placebo. By using superficial cells scraped from the surface of the cervical epithelium as a source of DNA for viral studies, we were able to investigate the relation between HPV and CIN without interfering with the natural history of the disease. HPV 16 was detected in lesions which persisted while HPV 6 only was detected in one lesion that regressed. Regression was clearly associated with reduction in the number of copies of viral DNA per cell in this case. Dual infection with HPV types 6 and 16 were recorded in two patients with persistent lesions. In one patient, hybridization studies indicated that infection with HPV 16 could have occurred after infection with type 6 was established, and it is postulated that this may have changed the nature of the cervical lesion.

Laboratory assessment of hepatic injury in the woodchuck (Marmota monax)

Normal reference values for total serum protein, albumin, cholesterol, alanine aminotransferase (ALT), aspartate aminotransferase (AST), sorbitol dehydrogenase (SDH), gamma glutamyl transferase (GGT), alkaline phosphatase (AP), and total bilirubin were established in 48 clinically healthy woodchucks. To validate the use of these biochemical tests in the woodchuck for assessment of liver injury, carbon tetrachloride was administered to produce hepatocellular necrosis and the common bile duct was surgically occluded to produce cholestasis. Biochemical tests were performed prior to experimental treatment and thereafter in surviving woodchucks for a period of 6 weeks. There were marked increases in the serum activities of AST, ALT, and SDH following carbon tetrachloride administration and all 3 enzymes appeared to be useful markers of acute hepatocellular injury. The predominate biochemical abnormalities in woodchucks with bile duct obstruction were hyperbilirubinemia, hypercholesterolemia and increased serum AP and GGT activities. The increase of GGT occurred earlier following bile duct obstruction and the magnitude of increase was greater than that of AP, suggesting that GGT would be the preferred serum enzyme test in the woodchuck for assessment of cholestatic liver injury.

Screening for wart virus infection in normal and abnormal cervices by DNA hybridisation of cervical scrapes

Cervical scrapings from 78 women attending a sexually transmitted diseases (STD) clinic, family planning clinic, and colposcopy clinic were assayed for human papillomavirus type 6 (HPV-6) by DNA hybridisation. Results of hybridisation were compared with clinical, colposcopic, and cytological findings. Scrapings from 2 of the 4 women with genital warts gave positive results with the HPV probe. No HPV-6 DNA was detected in scrapings from 18 women attending an FPC whereas scrapings from 2 of 19 STD clinic patients with normal colposcopic and cytological examination were positive-this means that DNA hybridisation detected wart virus infection where previously none was suspected. HPV-6 DNA was detected in about 10% of cervical scrapings from women with cervical intraepithelial neoplasia (CIN) both before and after treatment. Indeed in 2 patients in whom viral DNA persisted after laser therapy, it was associated with local recurrence of neoplasia. This non-invasive technique is suitable for use as a screening test for HPV infection. In this study it identified women who have a high risk of developing CIN and in whom close cytological and colposcopic surveillance is indicated.

Monoclonal antibodies for the histopathological diagnosis of cervical neoplasia

Five monoclonal antibodies (Ca1, HMFG 1 and 2, 8.30.3 and 77.1) were used to study the distribution of antibody binding sites in cervical tissue with a view to identifying a marker which would distinguish between benign and malignant cervical epithelium. Both benign tissue (mature and immature metaplastic squamous epithelium, congenital transformation zone and glandular epithelium) and neoplastic tissue (cervical intraepithelial neoplasia, 1, 2 and 3 and invasive squamous cell carcinoma) were stained by these antibodies. Although immature metaplastic epithelium stained strongly with all the antibodies, the intensity and distribution of staining in general did not distinguish between benign and neoplastic conditions. All five antibodies, raised against three different antigens, stained cervical tissue in a similar way and thus were unsuitable for use as specific tumour markers in equivocal cases. Further studies on other tumour markers are indicated in view of the potential value of this approach.

Proteolysis of ankyrin and of band 3 protein in chemically induced cell fusion. Ca2+ is not mandatory for fusion

Human erythrocytes were fused by incubation with 0.5-2 mM-chlorpromazine hydrochloride at pH 6.8-7.6. Fusogenic preparations of chlorpromazine were cloudy suspensions of microdroplets, and below pH 6.8 chlorpromazine gave clear solutions that were inactive. Unlike control cells, the lateral mobility of the intramembranous particles of the PF-fracture face of chlorpromazine-treated cells was relatively unrestricted, since the particles were partly clustered at 37 degrees C and they exhibited extensive cold-induced clustering. Ca2+ stimulated fusion, but fusion was only very weakly inhibited by EGTA (10 mM) and by N-ethylmaleimide (50 mM); pretreatment of the cells with Tos-Lys-CH2Cl (7-amino-1-chloro-3-L-tosylamidoheptan-2-one) (7.5 mM) markedly inhibited fusion. Changes in the membrane proteins of erythrocytes fused by chlorpromazine, before and after treatment with chymotrypsin to remove band 3 protein, were investigated. The several observations made indicate that the Ca2+-insensitive component of fusion is associated with degradation of ankyrin (band 2.1 protein) to band 2.3-2.6 proteins and to smaller polypeptides by a serine proteinase that is inhibited by Tos-Lys-CH2Cl, and that the component of fusion inhibited by EGTA and N-ethylmaleimide is associated with degradation of band 3 protein to band 4.5 protein by a Ca2+-activated cysteine proteinase. Proteolysis of ankyrin appeared to be sufficient to permit the chlorpromazine-induced fusion of human erythrocytes, but fusion occurred more rapidly when band 3 protein was also degraded in the presence of Ca2+. Since other cells have structures comparable with the spectrin-actin skeleton of the erythrocyte membrane, the observations reported may be relevant to the initiation of naturally occurring fusion reactions in biomembranes. It is also suggested that, should polypeptides with fusogenic properties be produced from integral and skeletal membrane proteins by endogenous proteolysis, their formation would provide a general mechanism for the fusion of lipid bilayers in biomembrane fusion reactions.