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Benign duodenal tumours have very rarely been reported in captive non-human primates and are also rare in human beings. Brunner's gland hyperplasia has not been fully described in a non-human primate. Here, we report Brunner's gland hyperplasia in a geriatric chimpanzee, which was an incidental finding during post-mortem examination.

Lynch syndrome (LS) is characterised by predisposition to colorectal, endometrial, and other cancers and is caused by inherited pathogenic variants affecting the DNA mismatch repair (MMR) genes MLH1, MSH2, MSH6, and PMS2. It is probably the most common predisposition to cancer, having an estimated prevalence of between 1/100 and 1/180. Resources such as the International Society for Gastrointestinal Hereditary Cancer's MMR gene variant database, the Prospective Lynch Syndrome Database (PLSD), and the Colon Cancer Family Register (CCFR), as well as pathological and immunological studies, are enabling advances in the understanding of LS. These include defined criteria by which to interpret gene variants, the function of MMR in the normal control of apoptosis, definition of the risks of the various cancers, and the mechanisms and pathways by which the colorectal and endometrial tumours develop, including the critical role of the immune system. Colorectal cancers in LS can develop along three pathways, including flat intramucosal lesions, which depend on the underlying affected MMR gene. This gives insights into the limitations of colonoscopic surveillance and highlights the need for other forms of anti-cancer prophylaxis in LS. Finally, it shows that the processes of autoimmunisation and immunoediting fundamentally constrain the development of tumours in LS and explain the efficacy of immune checkpoint blockade therapy in MMR-deficient tumours. © 2020 Pathological Society of Great Britain and Ireland. Published by John WileySons, Ltd.

Metastasis is the leading cause of death in cancer patients, and successful colonisation of a secondary organ by circulating tumour cells (CTCs) is the rate-limiting step of this process. We used tail-vein injection of B16-F10 melanoma cells into mice to mimic the presence of CTCs and to allow for the assessment of host (microenvironmental) factors that regulate pulmonary metastatic colonisation. We found that mice deficient for the individual subunits of the NADPH oxidase of myeloid cells, NOX2 (encoded by Cyba, Cybb, Ncf1, Ncf2, and Ncf4), all showed decreased pulmonary metastatic colonisation. To understand the role of NOX2 in controlling tumour cell survival in the pulmonary microenvironment, we focused on Cyba-deficient (Cybatm1a ) mice, which showed the most significant decrease in metastatic colonisation. Interestingly, histological assessment of pulmonary metastatic colonisation was not possible in Cybatm1a mice, owing to the presence of large granulomas composed of galectin-3 (Mac-2)-positive macrophages and eosinophilic deposits; granulomas of variable penetrance and severity were also found in Cybatm1a mice that were not injected with melanoma cells, and these contributed to their decreased survival. The decreased pulmonary metastatic colonisation of Cybatm1a mice was not due to any overt defects in vascular permeability, and bone marrow chimaeras confirmed a role for the haematological system in the reduced metastatic colonisation phenotype. Examination of the lymphocyte populations, which are known key regulators of metastatic colonisation, revealed an enhanced proportion of activated T and natural killer cells in the lungs of Cybatm1a mice, relative to controls. The reduced metastatic colonisation, presence of granulomas and altered immune cell populations observed in Cybatm1a lungs were mirrored in Ncf2-deficient (Ncf2tm1a ) mice. Thus, we show that NOX2 deficiency results in both granulomas and the accumulation of antitumoural immune cells in the lungs that probably mediate the decreased pulmonary metastatic colonisation. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Recent work has provided evidence for genetic and molecular heterogeneity in colorectal cancers (CRCs) arising in patients with Lynch syndrome (LS), dividing these into two groups: G1 and G2. In terms of mutation and gene expression profile, G1 CRCs bear resemblance to sporadic CRCs with microsatellite instability (MSI), whereas G2 CRCs are more similar to microsatellite stable CRCs. Here we review the current state of knowledge on pathways of precursor progression to CRC in LS and how these might tie in with the new findings. Immunotherapies are an active field of research for MSI cancers and their potential use for cancer therapy for both sporadic and LS MSI cancers is discussed.

Ethanol and its metabolite acetaldehyde have been classified as carcinogens for the upper aerodigestive tract, liver, breast, and colorectum. Whereas mechanisms related to oxidative stress and Cyp2e1 induction seem to prevail in the liver, and acetaldehyde has been proposed to play a crucial role in the upper aerodigestive tract, pathological mechanisms in the colorectum have not yet been clarified. Moreover, all evidence for a pro-carcinogenic role of ethanol in colorectal cancer is derived from correlations observed in epidemiological studies or from rodent studies with additional carcinogen application or tumour suppressor gene inactivation. In the current study, wild-type mice and mice with depletion of aldehyde dehydrogenase 1b1 (Aldh1b1), an enzyme which has been proposed to play an important role in acetaldehyde detoxification in the intestines, received ethanol in drinking water for 1 year. Long-term ethanol consumption led to intestinal tumour development in wild-type and Aldh1b1-depleted mice, but no intestinal tumours were observed in water-treated controls. Moreover, a significant increase in DNA damage was detected in the large intestinal epithelium of ethanol-treated mice of both genotypes compared with the respective water-treated groups, along with increased proliferation of the small and large intestinal epithelium. Aldh1b1 depletion led to increased plasma acetaldehyde levels in ethanol-treated mice, to a significant aggravation of ethanol-induced intestinal hyperproliferation, and to more advanced features of intestinal tumours, but it did not affect intestinal tumour incidence. These data indicate that ethanol consumption can initiate intestinal tumourigenesis without any additional carcinogen treatment or tumour suppressor gene inactivation, and we provide evidence for a role of Aldh1b1 in protection of the intestines from ethanol-induced damage, as well as for both carcinogenic and tumour-promoting functions of acetaldehyde, including increased progression of ethanol-induced tumours. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

In this eighteenth (2016) Annual Review Issue of The Journal of Pathology, we present a collection of 19 invited review articles that cover different aspects of cellular and animal models of disease. These include genetically-engineered models, chemically-induced models, naturally-occurring models, and combinations thereof, with the focus on recent methodological and conceptual developments across a wide range of human diseases.

Animal models are essential research tools in modern biomedical research, but there are concerns about their lack of reproducibility and the failure of animal data to translate into advances in human medical therapy. A major factor in improving experimental reproducibility is thorough communication of research methodologies. The recently published ARRIVE guidelines outline basic information that should be provided when reporting animal studies. This paper builds on ARRIVE by providing the minimum information needed in reports to allow proper assessment of pathology data gathered from animal tissues. This guidance covers aspects of experimental design, technical procedures, data gathering, analysis, and presentation that are potential sources of variation when creating morphological, immunohistochemical (IHC) or in situ hybridization (ISH) datasets. This reporting framework will maximize the likelihood that pathology data derived from animal experiments can be reproduced by ensuring that sufficient information is available to allow for replication of the methods and facilitate inter-study comparison by identifying potential interpretative confounders.

In this review, we discuss the application of mouse models to the identification and pre-clinical validation of novel therapeutic targets in colorectal cancer, and to the search for early disease biomarkers. Large-scale genomic, transcriptomic and epigenomic profiling of colorectal carcinomas has led to the identification of many candidate genes whose direct contribution to tumourigenesis is yet to be defined; we discuss the utility of cross-species comparative 'omics-based approaches to this problem. We highlight recent progress in modelling late-stage disease using mice, and discuss ways in which mouse models could better recapitulate the complexity of human cancers to tackle the problem of therapeutic resistance and recurrence after surgical resection.

K-ras mutations are found in ~40% of human colorectal adenomas and carcinomas and contribute to colorectal tumour formation at an early stage. Wild-type K-ras has been reported to be deleted in some tumours, but the consequences of changes in wild-type K-ras copy number for experimental colorectal carcinogenesis have not been investigated. To characterize the effects of K-ras copy number changes on formation of carcinogen-induced colorectal neoplasms in mice, wild-type (K-ras(+/+) ) and heterozygous K-ras exon 1 knockout (K-ras(+/-) ) mice were given 10 weekly treatments of 1, 2-dimethylhydrazine (DMH) to induce colorectal tumours. Colorectal expression levels of K-ras 4A and 4B transcripts in K-ras(+/-) mice were ~50% decreased compared with K-ras(+/+) mice. One year after DMH treatment, survival of K-ras(+/-) mice decreased from 88 to 82% compared with wild-type mice. Colorectal adenomas significantly increased from 0.52 ± 0.15 in K-ras(+/+) mice to 0.87 ± 0.14 in K-ras(+/-) mice (mean ± SEM per mouse, P

The tumour suppressor APC is the most commonly altered gene in colorectal cancer (CRC). Genetic and epigenetic alterations of APC may therefore be associated with dietary and lifestyle risk factors for CRC. Analysis of APC mutations in the extended mutation cluster region (codons 1276-1556) and APC promoter 1A methylation was performed on 185 archival CRC samples collected from participants of the European Prospective Investigation into Cancer (EPIC)-Norfolk Study, with the aim of relating these to high quality seven-day dietary and lifestyle data collected prospectively. Truncating APC mutations (APC+) and promoter 1A methylation (PM+) were identified in 43% and 23% of CRCs analysed, respectively. Distal CRCs were more likely than proximal CRCs to be APC+ or PM+ (P = 0.04). APC+ CRCs were more likely to be moderately/well differentiated and microsatellite stable than APC- CRCs (P = 0.05 and 0.03). APC+ CRC cases consumed more alcohol than their counterparts (P = 0.01) and PM+ CRC cases consumed lower levels of folate and fibre (P = 0.01 and 0.004). APC+ or PM+ CRC cases consumedhigher levels of processed meat and iron from red meat and red meat products (P=0.007 and 0.006). Specifically, CRC cases harbouring GC to AT transition mutations consumed higher levels of processed meat (35 versus 24 g/day, P = 0.04) and iron from red meat and red meat products (0.8 versus 0.6 mg/day, P = 0.05). In a logistic regression model adjusted for age, sex and cigarette smoking status, each 19g/day (1SD) increment increase in processed meat consumption was associated with cases with GC to AT mutations (OR 1.68, 95% CI 1.03-2.75). In conclusion, APC+ and PM+ CRCs may be influenced by diet and GC to AT mutations in APC are associated with processed meat consumption, suggesting a mechanistic link with dietary alkylating agents, such as N-nitroso compounds.

Endometriosis is a common chronic gynaecological condition, affecting 5-10% of women of child-bearing age. Its study has been hampered by lack of genetically tractable models. We transplanted steroid-manipulated, menstrual-like endometrium from K-ras(G12V/+) /Ah-Cre(+/+) /ROSA26R-LacZ(+/+) mice into gonad-intact immunocompetent wild-type mice. This led to endometriosis-like lesion development. Long-term lesion survival depended on the presence of the activated K-ras in the small proportion of the cells in the mature lesion that had undergone Cre-mediated K-ras activation. LacZ activity demonstrated Cre-mediated recombination in both endometrial epithelial cells and stromal cells, and transgenic K-ras expression was confirmed by RT-PCR. The endometriosis lesions developed without exogenous oestradiol supplementation and anti-oestrogen (fulvestrant, ICI 182780) treatment greatly suppressed their growth. Immunohistochemistry confirmed that as in human endometriosis, there was invasion and activation of fibroblasts, endothelial cells, and macrophages, with marked collagen deposition in the lesions. This model provides an opportunity to investigate endometriosis lesion establishment, growth, and regression in genetically tractable, immunocompetent, and hormonally intact mice. Furthermore, for the first time it provides a suitable model to test clinically validated driver genes in a faithful mouse model of the predisposing endometriotic lesion, thus providing the correct cellular context and microenvironment for ovarian clear cell carcinogenesis.

K-ras (KRAS) mutations are observed in around 40% of human colorectal adenomas and carcinomas. Previously, we developed and characterized a strain of transgenic mice with inducible intestinal epithelial expression of K-ras via a Cre/LoxP system. To evaluate the influence of mutant K-ras on carcinogen-induced colorectal tumourigenesis, we induced neoplastic alterations in the large intestines of wild-type and K-ras mice using the colon-selective carcinogen 1,2-dimethylhydrazine (DMH), which has been widely used to induce colorectal tumours that are histopathologically similar to those observed in humans. K-ras expression significantly promoted DMH-induced colorectal tumourigenesis: the average lifespan of the mice decreased from 38.52 ± 1.97 weeks for 40 control mice to 32.42 ± 2.17 weeks for 26 K-ras mice (mean ± SEM, p < 0.05) and the abundance of large intestinal tumours increased from 2.27 ± 0.15 per control mouse to 3.85 ± 0.20 in K-ras mice (mean ± SEM, p < 0.01). Adenomas from DMH-treated K-ras mice showed significantly higher proportions of Ki-67-positive proliferating cells (10.9 ± 0.69%) compared with those from DMH-treated wild-type mice (7.77 ± 0.47%) (mean ± SEM, p < 0.01) and a mild increase in apoptotic nuclei staining for cleaved caspase-3 (1.94 ± 0.21% compared with 1.15 ± 0.14%, mean ± SEM, p < 0.01). In the adenomas from DMH-treated K-ras mice, K-ras transgene recombination and expression were confirmed, with immunohistochemical evidence of strong Erk/MapK and mild PI3K/Akt pathway activation compared with adenomas from DMH-treated wild-type mice. Microarray hybridization and clustering analysis demonstrated different expression profiles in adenomas from DMH-treated wild-type and DMH-treated K-ras mice, indicating involvement of different molecular mechanisms including Erk/MapK and PI3K/Akt signalling in K-ras-expressing adenomas. Array-comparative genomic hybridization analysis showed chromosome stability in both cohorts, with only a very few tiny alterations observed in one adenoma from a DMH-treated K-ras mouse. Taken together, these data show that mutant K-ras significantly promotes DMH-induced colorectal tumourigenesis, resulting in distinct changes in cell signalling and proliferation, but does not alter chromosome stability in the tumours. Copyright © 2010 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

DNA mismatch repair (MMR) deficiency is one of the best understood forms of genetic instability in colorectal cancer (CRC), and is characterized by the loss of function of the MMR pathway. Failure to repair replication-associated errors due to a defective MMR system allows persistence of mismatch mutations all over the genome, but especially in regions of repetitive DNA known as microsatellites, giving rise to the phenomenon of microsatellite instability (MSI). A high frequency of instability at microsatellites (MSI-H) is the hallmark of the most common form of hereditary susceptibility to CRC, known as Lynch syndrome (LS) (previously known as hereditary non-polyposis colorectal cancer syndrome), but is also observed in approximately 15-20% of sporadic colonic cancers (and rarely in rectal cancers). Tumour analysis by both MMR protein immunohistochemistry and DNA testing for MSI is necessary to provide a comprehensive picture of molecular abnormality, for use in conjunction with family history data and other clinicopathological features, in order to distinguish LS from sporadic MMR-deficient CRC. Identification of the gene targets that become mutated in MMR-deficient tumours may explain, at least in part, some of the clinical, pathological and biological features of MSI-H CRCs and holds promise for developing novel therapeutics.

K-ras encodes two isoforms, K-ras 4A and 4B, that are jointly affected by K-ras activating mutations, which are prevalent in colorectal cancer (CRC). CRC shows alterations in the expressed K-ras 4A : 4B isoform ratio in favour of K-ras 4B, in tumours both with and without K-ras mutations. The present study evaluated whether K-ras 4A expression can suppress colonic adenoma development in the absence of its oncogenic allele. Mice with homozygous targeted deletions of K-ras exon 4A (K-ras(tmDelta4A/tmDelta4A)) that can express the K-ras 4B isoform only, along with heterozygous K-ras(tmDelta4A/+) and wild-type mice, were given ten weekly 1,2-dimethylhydrazine (DMH) treatments to induce colonic adenomas. There was a significant increase in both the number and the size of colonic adenomas in DMH-treated K-ras(tmDelta4A/tmDelta4A) mice, with reduced survival, compared with heterozygous and wild-type mice. No K-ras mutations were found in any of the 30 tumours tested from the three groups. Lack of expression of K-ras 4A transcripts was confirmed, whereas the relative expression levels of K-ras 4B transcripts were significantly increased in the adenomas of K-ras(tmDelta4A/tmDelta4A) mice compared with K-ras(tmDelta4A/+) and wild-type mice. Immunohistochemical studies showed that adenomas of K-ras(tmDelta4A/tmDelta4A) mice had significantly increased cell proliferation and significantly decreased apoptosis with evidence of activation of MapKinase and Akt pathways, with increased phospho-Erk1/2 and both phospho-Akt-Thr308 and phospho-Akt-Ser473 immunostaining, compared with adenomas from K-ras(tmDelta4A/+) and wild-type mice. In conclusion, following DMH treatment, K-ras exon 4A deletion promoted increased number and size of colonic adenomas showing increased K-ras 4B expression, increased proliferation, decreased apoptosis, and activation of MapKinase and Akt pathways, in the absence of K-ras mutations. Therefore, K-ras 4A expression had a tumour suppressor effect on carcinogen-induced murine colonic adenoma formation, explaining the selective advantage of the altered K-ras 4A : 4B isoform ratio found in human colorectal cancer.

In a study of 109 colorectal cancers, DNA copy number aberrations were identified by comparative genomic hybridization using a DNA microarray covering the entire genome at an average interval of less than 1 Mbase. Four patterns were revealed by unsupervised clustering analysis, one of them associated with significantly better prognosis than the others. This group contained tumours with short, dispersed, and relatively few regions of copy number gain or loss. The good prognosis of this group was not attributable to the presence of tumours showing microsatellite instability (MSI-H). Supervised methods were employed to determine those genomic regions where copy number alterations correlate significantly with multiple indices of aggressive growth (lymphatic spread, recurrence, and early death). Multivariate analysis identified DNA copy number loss at 18q12.2, harbouring a single gene, BRUNOL4 that encodes the Bruno-like 4 splicing factor, as an independent prognostic indicator. The data show that the different patterns of DNA copy number alterations in primary tumours reveal prognostic information and can aid identification of novel prognosis-associated genes.

Summary K-ras mutations are found in 40-50% of human colorectal adenomas and carcinomas, but their functional contribution remains incompletely understood. Here, we show that a conditional mutant K-ras mouse model (K-ras(Asp12)/Cre), with transient intestinal Cre activation by beta-Naphthoflavone (beta-NF) treatment, displayed transgene recombination and K-ras(Asp12) expression in the murine intestines, but developed few intestinal adenomas over 2 years. However, when crossed with Apc(Min/+) mice, the K-ras(Asp12)/Cre/Apc(Min/+) offspring showed acceleration of intestinal tumourigenesis with significantly changed average lifespan (P

Megaoesophagus, or oesophageal achalasia, is a neuromuscular disorder characterized by an absence of peristalsis and flaccid dilatation of the oesophagus, resulting in the retention of ingesta in the dilated segment. The aetiology and pathogenesis of idiopathic (or primary) megaoesophagus are still poorly understood and very little is known about the genetic causes of megaoesophagus in humans. Attempts to develop animal models of this condition have been largely unsuccessful and although the ICRC/HiCri strain of mice spontaneously develop megaoesophagus, the underlying genetic cause remains unknown. In this report, we show that aged Rassf1a-null mice have an enhanced susceptibility to megaoesophagus compared with wild-type littermates (approximately 20%vs. approximately 2% incidence respectively; P = 0.01). Histological examination of the dilated oesophaguses shows a reduction in the numbers of nerve cells (both ganglia and nerve fibres) in the myenteric plexus of the dilated mid and lower oesophagus that was confirmed by S100 immunohistochemistry. There was also a chronic inflammatory infiltrate and subsequent fibrosis of the myenteric plexus and the muscle layers. These appearances closely mimic the gross and histopathological findings in human cases of megaoesophagus/achalasia, thus demonstrating that this is a representative mouse model of the disease. Thus, we have identified a genetic cause of the development of megaoesophagus/achalasia that could be screened for in patients, and may eventually facilitate the development of therapies that could prevent further progression of the disease once it is diagnosed at an early stage.

Acute appendicitis is a diagnosis that can be made on clinical symptoms and signs but can often be extremely challenging. Difficulties arise particularly when the presentation is atypical, and this can lead to untoward sequelae. In this review, we present the range of presentations of atypical appendicitis, the variety of management options and the potential value of CT.

An immunohistochemical method for assessing cell-cycle phase distribution in colorectal resection specimens would enable phase data to be incorporated into diagnostic algorithms for the estimation of prognosis and response to adjuvant chemotherapy in colorectal cancer. In contrast to flow cytometry, an immunohistochemical method would also allow the phase distribution to be examined within morphologically heterogeneous regions of neoplasms. Paraffin sections of normal colon (n = 25), colonic adenoma (n = 15), and colonic adenocarcinoma (n = 30) were analysed by immunohistochemistry using antibodies against markers of cell-cycle entry, Mcm-2 and Ki67, and putative markers of the cell-cycle phase, cyclins D1 and E (putative markers of G1 phase), cyclin A (S phase), cytoplasmic cyclin B1 (G2 phase), and phosphohistone H3 (M phase). The phase specificity of each marker was assessed by examining the degree of co-expression of adjacent phase markers using double-antibody fluorescence confocal microscopy and by comparison with flow cytometric analysis performed on adjacent tissue sections. The S-phase specificity of detectable cyclin A was also assessed in combination with in situ DNA replication using fluorescence confocal microscopy. All cells expressing phase markers co-expressed Mcm-2. Adjacent phase markers were not significantly co-expressed, confirming the relative specificity of these markers in tissue sections of colon. Cell-cycle phase distribution, calculated by immunohistochemistry, compared well with phase analyses obtained by flow cytometry. No cells expressed cyclin A in the absence of active DNA replication. The S-phase labelling index, as defined by detectable cyclin A expression, showed a positive correlation with the Mcm-2 labelling index and increased in the progression from normal colon to adenocarcinoma. In conclusion, a combination of these cell-cycle phase markers can be used to calculate the distribution of cells throughout each phase of the cell cycle in colorectal tissue sections. Detectable cyclin A can be used as a surrogate marker of S phase and may be of value in predicting prognosis and response to adjuvant therapy.

The death of macrophages contributes to atheroma formation. Oxidation renders low-density lipoprotein (LDL) cytotoxic to human monocyte-macrophages. Lipoprotein-associated phospholipase A2 (Lp-PLA2), also termed platelet-activating factor acetylhydrolase, hydrolyses oxidised phospholipids. Inhibition of Lp-PLA2 by diisopropyl fluorophosphate or Pefabloc (broad-spectrum serine esterase/protease inhibitors), or SB222657 (a specific inhibitor of Lp-PLA2) did not prevent LDL oxidation, but diminished the ensuing toxicity and apoptosis induction when the LDL was oxidised, and inhibited the rise in lysophosphatidylcholine levels that occurred in the inhibitors’ absence. Hydrolysis products of oxidised phospholipids thus account for over a third of the cytotoxic and apoptosis-inducing effects of oxidised LDL on macrophages.

Colorectal cancer is the second commonest malignancy in the western world, accounting for 20 000 deaths in the U.K. per year. Over the last 10 years, great strides have been made in our understanding of the molecular controls governing the transition from normal mucosa, through adenoma, and finally to carcinoma. This review focuses on the recently discovered DNA mismatch repair pathway and its role in the development of both sporadic and an inherited form of colorectal cancer, namely hereditary non-polyposis colorectal cancer (HNPCC).1,2 © 1998 John Wiley & Sons, Ltd.

The effects of a 10% NaOCl treatment for 2 min on demineralized human root dentin were investigated by means of: microradiography (MR), scanning electron microscopy (SEM), confocal laser scanning microscopy (CLSM) and secondary ion mass spectroscopy (SIMS). MR measurements revealed that NaOCl caused a tissue contraction not related to water loss but to removal of organic substance(s), resulting in reductions of the lesion depth and mineral loss values by 15% and 42%, respectively. CLSM observations on wet dentin showed that the dentinal tubules underneath the surface are clearly observable and not deformed substantially by the NaOCl, except near the outermost surface. This indicates the importance of wet as well as of dried (high vacuum) observations. SEM micrographs (high vacuum) showed definite changes in the outer dentin surface structure; 85% of the originally open dentinal tubules were closed after NaOCl treatment. No marked changes were observed in the dentin ultrastructure inside lesions, as shown by SEM on fractured surfaces. SIMS data, pertaining to samples in high vacuum, showed a remarkable increase of chlorine (Cl) content in the entire lesion due to the NaOCl, indicating deep penetration of the original OC1 ions. The results suggest that the 2-min treatment of demineralized dentin by NaOCl solutions removes and/or changes part of the dentin matrix in nearly the whole lesion. As a consequence the mineral is somewhat redistributed, the outermost surface of a few mu m is changed, but the main dentin structure and element composition are still intact. These findings indicate that NaOCl treatments are of interest in remineralization and hyper-remineralization studies of dentin.

As yet recombinant DNA technology does not appear to have widespread diagnostic application in pathology. However, it does have a useful role to play in specific circumstances in at least three main areas: a it can provide precise diagnostic information about genetic diseases, allowing appropriate counselling, and indicating future directions for research on therapeutic intervention, e.g. gene therapy; b micro-organisms can be identified more sensitively and specifically, in fresh or fixed tissue samples, and their genomes can be analysed in fine detail, providing information relevant to the aetiology, epidemiology and pathogenesis of many diseases; c in tumour pathology the main application so far has been to resolve diagnostic problems associated with leukaemias and lymphomas, when other diagnostic procedures have been inconclusive. Specific chromosomal translocations, involving recognized genes, are particularly amenable to diagnosis by these means. Diagnostic applications to solid tumours are yet to be identified, although significant insights into tumorigenesis have been obtained, and these may ultimately lead to the development of useful markers for prognostic and therapeutic purposes.

In this study we investigated the possibility of using sulcus temperature measurements as an early indicator for the beginning of gingival inflammation. Sulcus temperature distributions over the arches appeared to obey a quadratic polynomial. With a test group of 10 volunteers, all dental students, small changes in temperature were measured after subjects refrained from all oral hygiene: A slight but significant tendency for the frontal temperature to increase after 14 days of no oral hygiene was, however, present. The quality of a quadratic polynomial fit of the temperature distributions over the arches decreased significantly, already after 3 d of non-oral hygiene. This indicates that the coefficient of quadratic correlation for the temperature distributions over the arches is a measure for the oral hygiene of patients and for changes in the physiology of gingival tissues. Furthermore, as its decrease was concurrent with an increase in plaque and gingival indices, it might serve as an early indicator for the beginning of gingival inflammation. However, further development work is needed in order to make this approach useful as a clinical tool.

A new type-specific, sensitive, non-radioactive assay is described for the detection of human papillomavirus (HPV) DNA in tissues. Sequences within the E6 gene were amplified by the polymerase chain reaction (PCR), using primer pairs which clearly distinguish HPV types, including those with close sequence homology such as 6b and 11. The amplified DNA products were identified by non-radioactive oligonucleotide hybridization and restriction endonuclease mapping, and the method was sufficiently sensitive to detect between 3 and 5 SiHa cells (each containing 1-2 copies of HPV 16 DNA) amongst 10,000 non-HPV-containing cells. Frozen and archival paraffin sections were equally acceptable substrates for the reaction. The assay was applied to frozen sections of full thickness cervical epithelium from 60 cases of cervical intraepithelial neoplasia (CIN) and 24 normal cervical controls. HPV DNA was detected in 60 per cent of cases of CIN 3 and CIN 2, in 25 per cent of cases of CIN 1, and in none of the normal controls. Prevalence of HPV 16 was similar (approximately 50 per cent) in both CIN 2 and CIN 3, and in the whole series HPV 16 was almost five-fold more common than HPV 18. Low-risk HPV types were present in 5 per cent of CIN 1, but 0 per cent of CIN 2 and CIN 3 biopsies. The data emphasize the biological similarity of CIN 2 and CIN 3 lesions, and their divergence from CIN 1.

HPVs cannot be cultured in vitro, and the viral antigens which can be detected immunocytochemically do not accurately specify the HPV type, hence attention has focused on the detection of HPV DNA. Four methods are available: Southern or dot blotting, in situ hybridization (ISH), and polymerase chain reaction (PCR). In practice, many samples are too small to yield sufficient extracted DNA for dot or Southern blotting, essentially leaving a choice of ISH or PCR

Two cases of primary intracranial germ cell tumours are reported. Both serum alpha-fetoprotein (AFP) and serum human chorionic gonadotropin (hCG) were raised preoperatively, but became normal during postoperative radio- and chemotherapy. Immunofluorescence microscopy of tissue specimens from both tumours showed a slight staining for AFP mainly localized in the endodermal vesicles, whereas a more intensive staining for hCG could be identified in the giant cells.

Replicas of unerupted and erupted human enamel submitted to protein-disrupting solutions showed: (1) an inequal distribution of porosities in the subsurface; (2) such porosities were restricted gradually in each enamel subunit (enamel segments limited by two perikymata). First the whole surface was covered by a network, reduced at a later stage to half of the surface and ultimately the porosities were present only in the perikymata. This paper confirms the occurrence of a late maturation at stage where cells are no longer active and details the time-dependent involution of these porosities.

To determine whether the surface free energy of polymer materials influences the spreading of 13 polymers and glass were related to spreading and growth of human skin fibroblasts. Experiments were performed in both the presence and absence of serum proteins. We calculated the surface free energy from contact angles of phosphate-buffered saline (PBS), n-propanol/PBS mixtures, and alpha-bromonaphthalene on the polymers, using the concept of polar and dispersion components accounting for spreading pressures. Cell spreading and substratum surface free energy (gamma s) showed a characteristic sigmoid relationship both in the presence and in the absence of serum proteins; good spreading only occurred when gamma s was higher than approximately 57 erg . cm-2. In the presence of serum proteins, cell spreading is similar on most materials; only few materials show relatively high cell spreading. Cell growth in the presence of serum proteins did not differ significantly on the various polymers with reference to their gamma s values. In contrast, two groups of polymers could be distinguished in the absence of serum with respect to cell growth. The first group showed increasing cell growth with increasing gamma s, whereas the second group showed consistently low cell growth. The results demonstrate the complex relationship between cell spreading and substratum surface free energy as well as the role of serum proteins in modifying the surface characteristics of polymers in relation to cell spreading and growth.

A 17 year old man with a primary intracranial germ cell tumor in the pituitary region is reported. Both serum alpha-fetoprotein (AFP) and serum human chorionic gonadotropin (hCG) were found elevated preoperatively. Normal levels of serum AFP and hCG were found after operation and radiotherapy. By indirect immunofluorescence staining of the tumor tissue a slight staining for AFP was localized to the endodermal vesicles, whereas a more intensive staining for hCG could be identified in the giant cells.

Human alpha1-fetoprotein (AFP) and choriongonadotropin (hCG) have been studied in 67 patients with malignant germ cell neoplasia of the testis admitted to the Radium Centre, Aarhus Municipal Hospital within an 18 month period. In 34 patients with nonseminoma, AFP was elevated in 35% of cases, and hCG in 38% of cases. Nonseminoma patients who presented with or developed distant metastases showed a significantly higher incidence of elevated tumor markers than patients with local or regional disease. In patients with distant metastases monitoring of AFP and/or hCG was a most sensitive and reliable indicator of disease activity. In the management of such patients these tests are as important as clinical and x-ray examinations. Cancer 42:2182–2186, 1978.

A method is described to quantify marginal leakage of amalgam restorations in vitro as a function of time. The method consists of the determination of the amount of nitrogen gas passing through the margins of the restoration at 2 atm. pressure in 30 min. The method described needs about sixteen specimen per experiment. The standard error is 20-30% of the mean leakage value and is independent of the type of condensation and the amalgam type. Two amalgams, the non-gamma 2-Dispersalloy and the conventional, Amalcap was compared longitudinally over a period of 4 months. The results showed: (1) The marginal leakage of Dispersalloy decreased strongly with time; the time dependency of Amalcap was less pronounced. (2) That carefully condensed Amalcap showed significantly less marginal leakage than Dispersalloy. (3) Whereas the marginal leakage of Amalcap was dependent on the condensation procedure, the leakage of Dispersalloy did not depend strongly on it.

The DATECA Project was started in January 1976 and includes all patients with testicular cancer in Denmark. During the first 6 years, 1246 patients entered the joint protocol for histology, staging, management, and clinical use of tumor markers. Only 746 DATECA patients fulfilled the claims for being ideally monitored with preoperative as well as postoperative serologic marker determinations. The overall prevalence of marker positivity, that is, elevated preoperative values of alpha-fetoprotein (AFP) and/or human chorionic gonadotrophin (HCG) was 8% for patients with seminoma and 63% for patients with nonseminomatous disease. The prevalence of increased marker concentration in serum was correlated to stage (higher prevalence in higher stages) and to prognosis (marker-negative patients had a better prognosis than did marker-positive patients). An increased concentration of AFP or HCG was correlated with the presence of a primary endodermal sinus tumor and choriocarcinoma component, respectively.

In this study the preparation of three polyvinylpyridinium fluorides with different hexadecyl group contents is described. Their adsorption on hydroxyapatite (the main constituent of dental enamel) was studied as a function of time and concentration. It was found that increasing hexadecyl group content resulted in lower amounts of adsorbed polymer. The adsorption of the polyelectrolytes is accompanied with the uptake of fluoride by hydroxyapatite at a higher rate and with greater amounts. Phosphate ions present in aqueous suspensions of hydroxyapatite were responsible for this phenomenon. Desorption experiments showed that the adsorption of these macromolecules was irreversible in water. Excess calcium resulted to some extent in desorption.

SUMMARY Twenty-seven healthy females referred for legal abortion between the sixth and ninth week of pregnancy were treated for 1 week with either bromocriptine, metoclopramide or placebo. Serum prolactin was significantly (P < 0·01) elevated by metoclopramide and suppressed by bromocriptine. Despite a more than tenfold difference in circulating prolactin levels among these two groups, no significant difference was found in serum levels of progesterone, oestradiol, human chorionic gonadotrophin (hCG) human placental lactogen (hPL) or pregnancy specific B1-glycoprotein (SP1). These data suggest that circulating levels of prolactin below 150 ng/ml are without effect on either luteal or placental hormone secretion during early human pregnancy.

Ionic conductivity measurements are made on single crystals of CsCl doped with Rb+, K+, and Br−. The results indicate that small concentrations of these monovalent ions have a marked effect on the activation energies in the NaCl and the CsCl phases and also on the hysteresis behaviour. It is shown that the decrease of the activation energies in crystals doped with Rb+ and K+ and the independence of these energies of the Br− content, can be described in terms of the size of the ions. The decrease of the pre-exponential factor in crystals doped with K+ or Rb+ is probably due to a change in the frequency spectrum of the lattice vibrations. An CsCl-Einkristallen mit eingebauten Rb+-, K+- oder Br−-Ionen wurden Ionenleitfahigkeitsmessungen durchgefuhrt. Die Mesergebnisse weisen darauf hin, das kleine Zusatze dieser einwertigen Fremdionen einen merklichen Effekt auf die Aktivierungsenergien der NaCl- und der CsCl-Struktur und auf die Hysteresis im Ubergangsgebiet ausuben. Es wird gezeigt, das die Abnahme der Aktivierungsenergien in mit Rb+ oder K+ dotierten Kristallen und die Unabhangigkeit dieser Energien von der Br− Konzentration sich als ein Effekt der Ionenradien interpretieren lassen. Die Abnahme des pre-exponentiellen Faktors in Kristallen mit eingebauten K+ oder Rb+ wird wahrscheinlich durch eine Anderung des Frequenzspektrums der Gitterschwingungen verursacht.

The isotropic hfs constants of F-centers in alkaline-earth fluorides and the g-shift in CaF2 are calculated using various published wave functions. The computed results of these calculations are then compared with experiment in order to assess the validity of the wave functions. The wave functions studied give the correct order of magnitude for the isotropic hfs constants of the first shell of F− -ions surrounding the vacancy. For the second shell of F−-ions a few wave functions give values in agreement with experiment. Die isotropen HFS-Konstanten fur F-Zentren in Fluoriden der Erdalkalimetalle und die g-Verschiebung in CaF3 werden unter Benutzung mehrerer bekannter Wellenfunktionen berechnet. Diese berechneten Werte werden zur Uberprufung der Gultigkeit der verschiedenen Wellenfunktionen mit den experimentell bekannten isotropen HFS-Konstanten und g-Werten verglichen. Die Ergebnisse weisen darauf hin, das die untersuchten Wellenfunktionen die richtige Grosenordnung der isotropen HFS-Konstanten fur die F−-Ionen in der ersten Koordinationsschale um die Leerstelle liefern. Unter Berucksichtigung der zweiten Koordinationsschale von F−-Ionen ergaben einige Wellenfunktionen Werte, die befriedigend mit den experimentellen Daten im Einklang sind.

Optical studies are made of the composition dependence of the colorability of mixed alkali halide crystals after X-ray irradiation at room temperature. A pronounced minimum coloration is found at about the equimolar concentration in solid solutions of KCl–RbCl, KCl–KBr, and KBr–RbBr. The final slopes of the F-center growth curves are smaller for the mixed crystals than for the pure components. An analysis of the results indicates that at room temperature the F-centers are essentially formed during the initial stage of coloration. Es werden Ergebnisse optischer Absorptionsmessungen uber die Rontgen-Verfarbbarkeit von Mischkristallen der Alkalihalogenide bei Zimmertemperatur beschrieben. Die Messungen zeigen, das die Verfarbbarkeit in Abhangigkeit von der Konzentration ein ausgepragtes Minimum hat. Fur Mischkristalle KCl-RbCl, KCl-KBr und KBr–RbBr liegt dieses Minimum bei etwa equimolarer Zusammensetzung. Die endgultigen Neigungen der Farbzentrenerzeugungskurven sind bei den Mischkristallen kleiner als bei den reinen Komponenten. Die Ergebnisse weisen darauf hin, das die Erzeugung der F-Zentren bei Zimmertemperatur in der Anfangsstufe des Verfarbungsvorganges stattfindet.

Schottky defects in apatites are formed by a decomposition reaction at temperatures in excess of 1000°K. In this investigation thermogravimetrie experiments on fluorapatite single crystals and powders have been carried out in the temperature range 1000–1600°K. Relative weightlosses of 1.2 × 10−3 per hour corresponding to Ca/P decreases of 0.0002 per hour have been observed at 1675°K. In the temperature range studied the number of vacancy triplets formed per second is in the order of 1018. The activation energy (1.15 eV) involved indicates that dislocations might play an important role in the decomposition process. In Apatiten hat eine Zersetzungsreaktion bei Temperaturen uber 1000°K die Bildung von Schottky-Fehlstellen zur Folge. Es wurden thermogravimetrische Versuche an Fluorapatit-einkristallen und -pulver im Bereich von 1000 bis 1600°K durchgefuhrt. Bei 1675°K konnten relative Gewichtsverluste von 1.2 × 10−3 pro Stunde beobachtet werden, was eine Herabsetzung des Ca/P-Verhaltnisses von 0,0002 pro Stunde bedeutet. Im studierten Temperaturbereich werden nahezu 1018 Schottky-Triplette pro Sekunde gebildet. Die gemessene Aktivierungsenergie von 1,15 eV weist darauf hin, das Dislokationsfehlstellen wahrend des Zersetzungsvorganges eine wichtige Rolle spielen konnten.

Results are presented for electron spin resonance measurements carried out at room temperature on freshly powdered high purity quartz and fused silica. As a result of the powdering, unpaired electrons are produced in concentrations of 1014 to 1015 per gram, depending on the particle size. The thermal stability of the centers is studied at various temperatures. A discussion of the shape of the resonance line is given, in terms of a model based on an anisotropic g-factor, and a random distribution of the orientations of the symmetry axes of the individual centers. Es werden Ergebnisse von Elektronenspinresonanz-Messungen bei Zimmertemperatur an pulverisiertem Quarz und Quarzglas beschrieben. Das Pulvern bringt ungepaarte Elektronen hervor, deren Konzentration, abhangig von der Teilchengrose, Werte von 1014 bis 1015 pro Gramm erreicht. Die thermische Stabilitat der Zentren wurde bei verschiedenen Temperaturen untersucht. Es wurde versucht, die Form der Resonanzlinie mit Hilfe eines Modells mit anisotropen g-Faktor und willkurlicher Orientierung der Symmetrieachsen der Zentren zu deuten.