Renal biopsies from donors with acute kidney injury show different molecular patterns according to the post-transplant function

The utilization of kidneys from donors with acute kidney injury (AKI) is often limited by unpredictable post-transplantation outcomes. The aim of our study was to identify protein mediators implicated in either recovery or failure of these organs. Forty kidney biopsies from donors with (20) and without AKI (20) were selected and then subdivided according to the post-transplant outcome defined as a threshold of 45 ml/min for the eGFR at 1 year from transplantation. Tissue homogenates were analysed by western blot to assess how the levels of 17 pre-selected proteins varied across the four groups. Samples from AKI kidneys with a poor outcome showed a fourfold increase in the levels of PPARg and twofold reduction of STAT1 compared to the other groups (p < 0.05). On the contrary, antioxidant enzymes including TRX1 and PRX3 were increased in the AKI kidneys with a good outcome (p < 0.05). An opposite trend was observed for the detoxifying enzyme GSTp which was significantly increased in the AKI group with poor versus good outcome (p < 0.05). The importance of lipid metabolism (PPARg) and inflammatory signals (STAT1) in the function recovery of these kidneys hints to the therapeutical targeting of the involved pathways in the setting of organ reconditioning.

Are acute type A aortic dissections atherosclerotic?

Background

Type A aortic dissections (TAAD) are devastating aortic complications. Patients with Marfan syndrome, a bicuspid aortic valve or a thoracic aortic aneurysm have an increased risk to develop a TAAD. These predisposing conditions are characterized by a histologically thin intimal layer and hardly any atherosclerosis. Little is known about the susceptibility for atherosclerosis in patients with a type A aortic dissection.

Objective

We aim to systematically describe atherosclerotic lesions in TAAD patients.

Materials and methods

A total of 51 patients with a TAAD (mean age 62.5 ± 10.8 years, 49% females) and 17 control patients (mean age 63 ± 5.5 years, 53% females) were included in this study. Cardiovascular risk factors were assessed clinically. All sections were stained with Movat pentachrome and hematoxylin eosin. Plaque morphology was classified according to the modified AHA classification scheme proposed by Virmani et al.

Results

In the TAAD group thirty-seven percent were overweight (BMI > 25). Diabetes and peripheral arterial disease were not present in any of the patients. Fifty-nine percent of the patients had a history of hypertension. The intima in TAAD patients was significantly thinner as compared to the control group (mean thickness 143 ± 126.5 μm versus 193 ± 132 μm, p < 0.023). Seven TAAD patients had a normal intima without any form of adaptive or pathological thickening. Twenty-three TAAD patients demonstrated adaptive intimal thickening. Fourteen had an intimal xanthoma, also known as fatty streaks. A minority of 7 TAAD patients had progressive atherosclerotic lesions, 4 of which demonstrated pathological intimal thickening, 3 patients showed early fibroatheroma, late fibroatheroma and thin cap fibroatheroma. In the control group the majority of the patients exhibited progressive atherosclerotic lesions: three pathologic intimal thickening, two early fibroatheroma, six late fibroatheroma, one healed rupture and two fibrotic calcified plaque.

Discussion

This study shows that TAAD patients hardly exhibit any form of progressive atherosclerosis. The majority of TAAD patients showcase non-progressive intimal lesions, whereas the control group mostly demonstrated progressive intimal atherosclerotic lesions. Findings are independent of age, sex, or the presence of (a history of) hypertension.

Randomized clinical trial of mast cell inhibition in patients with a medium-sized abdominal aortic aneurysm

Background

Abdominal aortic aneurysm (AAA) is thought to develop as a result of inflammatory processes in the aortic wall. In particular, mast cells are believed to play a central role. The AORTA trial was undertaken to investigate whether the mast cell inhibitor, pemirolast, could retard the growth of medium-sized AAAs. In preclinical and clinical trials, pemirolast has been shown to inhibit antigen-induced allergic reactions.

Methods

Inclusion criteria for the trial were patients with an AAA of 39–49 mm in diameter on ultrasound imaging. Among exclusion criteria were previous aortic surgery, diabetes mellitus, and severe concomitant disease with a life expectancy of less than 2 years. Included patients were treated with 10, 25 or 40 mg pemirolast, or matching placebo for 52 weeks. The primary endpoint was change in aortic diameter as measured from leading edge adventitia at the anterior wall to leading edge adventitia at the posterior wall in systole. All ultrasound scans were read in a central imaging laboratory.

Results

Some 326 patients (mean age 70·8 years; 88·0 per cent men) were included in the trial. The overall mean growth rate was 2·42 mm during the 12-month study. There was no statistically significant difference in growth between patients receiving placebo and those in the three dose groups of pemirolast. Similarly, there were no differences in adverse events.

Conclusion

Treatment with pemirolast did not retard the growth of medium-sized AAAs. Registration number: NCT01354184 (https://www.clinicaltrials.gov).

Autologous bone marrow derived mesenchymal stromal cell therapy in combination with everolimus to preserve renal structure and function in renal transplant recipients

Background

Kidney transplantation has improved survival and quality of life for patients with end-stage renal disease. Despite excellent short-term results due to better and more potent immunosuppressive drugs, long-term survival of transplanted kidneys has not improved accordingly in the last decades. Consequently there is a strong interest in immunosuppressive regimens that maintain efficacy for the prevention of rejection, whilst preserving renal structure and function. In this respect the infusion of mesenchymal stromal cells (MSCs) may be an interesting immune suppressive strategy. MSCs have immune suppressive properties and actively contribute to tissue repair. In experimental animal studies the combination of mammalian target of rapamycin (mTOR) inhibitor and MSCs was shown to attenuate allo immune responses and to promote allograft tolerance. The current study will test the hypothesis that MSC treatment, in combination with the mTOR inhibitor everolimus, facilitates tacrolimus withdrawal, reduces fibrosis and decreases the incidence of opportunistic infections compared to standard tacrolimus dose.

Methods/design

70 renal allograft recipients, 18–75 years old, will be included in this Phase II, open label, randomized, non-blinded, prospective, single centre clinical study. Patients in the MSC treated group will receive two doses of autologous bone marrow derived MSCs IV (target 1,5x10⁶, Range 1-2x10⁶ million MSCs per/kg body weight), 7 days apart, 6 and 7 weeks transplantation in combination with everolimus and prednisolone. At the time of the second MSC infusion tacrolimus will be reduced to 50% and completely withdrawn 1 week later. Patients in the control group will receive everolimus, prednisolone and standard dose tacrolimus. The primary end point is to compare fibrosis by quantitative Sirius Red scoring of MSC treated and untreated groups at 6 months compared to 4 weeks post-transplant. Secondary end points include: composite end point efficacy failure (Biopsy Proven Acute Rejection, graft loss or death); renal function and proteinuria; opportunistic infections; immune monitoring and “subclinical” cardiovascular disease groups by assessing echocardiography in the different treatment groups.

Discussion

This study will provide information whether MSCs in combination with everolimus can be used for tacrolimus withdrawal, and whether this strategy leads to preservation of renal structure and function in renal recipients.

Trial registration

NCT02057965.

One lesion, one virus: individual components of high-grade anal intraepithelial neoplasia in HIV-positive men contain a single HPV type

BACKGROUND

High-grade anal intraepithelial neoplasia (AIN) is present in many human immunodeficiency virus (HIV)-positive men who have sex with men. The major etiologic factor is infection with an oncogenic human papillomavirus (HPV) genotype. We investigated whether individual components of high-grade AIN are caused by single HPV types.

METHODS

DNA was isolated from whole-tissue sections of 31 high-grade AIN that were recovered from 21 HIV-positive men who have sex with men. The SPF10 PCR/LiPA25 HPV genotyping system was used for DNA analysis. In whole-tissue sections with multiple HPV types, polymerase chain reaction was repeated in regions of AIN sampled by laser-capture microdissection. The results were compared with HPV types in anal swabs.

RESULTS

A single HPV type was observed in 15 (48%) of 31 whole-tissue sections. In an additional 14 whole-tissue sections, 1 HPV type was found in each lesion sample evaluated by laser-capture microdissection. Consequently, in 29 of 31 biopsy specimens (94%), a single HPV type was found in each lesional component studied. Two whole-tissue sections contained collision regions, each with 2 HPV types. HPV16 was presumed to be causative in 14 of 31 biopsy specimens (45%). More than half of the anal swabs did not contain all causative HPV types.

CONCLUSIONS

Individual components of high-grade AIN are caused by single HPV types (the so-called one lesion, one virus concept). HPV16 is causative in <50% of cases. Anal swabs are not useful for detecting lesion-specific HPV types.

34. One lesion, one virus: individual components of high-grade anal intraepithelial neoplasia in HIV+ men contain a single HPV type

Background Anal intraepithelial neoplasia (AIN) is present in the majority of HIV+ men who have sex with men (MSM). The main aetiological factor is human papilloma virus (HPV). We analysed whether HPV PCR genotyping of whole tissue sections (WTS) and subsequent laser capture microdissection (LCM) detects type-specific HPV DNA in individual areas of HGAIN, and compared these lesional HPV genotypes with HPV types in anal swabs. Methods: DNA was isolated from anal swabs and WTS of 31 HGAIN biopsies obtained from 21 HIV+ MSM and analysed by the SPF10 PCR/LiPA25 HPV genotyping system. In case of multiple HPV types per WTS, PCR was repeated in selected areas of AIN obtained by LCM. Results: A single HPV type was observed in 15 (48%) of 31 WTS. In the 16 WTS with multiple HPV types, LCM-isolated dysplastic areas were studied. In 14 of the 16 WTS, one single HPV type was demonstrated within each discrete area of the lesion, resulting in a total of 29 (15+14) biopsies in which a single HPV type was found in (all components of) the lesion. HPV 16 was found in 14 of 31 biopsies (45%). In almost half the biopsies, lesional HPV types were not detected in the anal swabs. Conclusions: WTS PCR and subsequent LCM PCR is accurate in detecting lesion-specific HPV types in HGAIN and in 94% of the biopsies a single HPV was found in (each component of) the HGAIN lesion. In the majority, HPV16 was not the causative type and HPV genotyping of anal swabs was not useful in detecting the lesion-specific type.

Detection of a soluble form of BACE-1 in human cerebrospinal fluid by a sensitive activity assay

BACKGROUND

Formation of deposits of the insoluble amyloid beta-peptide is believed to be causally related with neurodegeneration in Alzheimer disease (AD). The beta-peptide originates from a larger amyloid precursor protein (APP) by the action of proteolytic enzymes. The first proteolytic event leading to amyloid formation is the cleavage of APP by the membrane-bound aspartyl protease BACE-1, also known as memapsin-2. Inhibition of BACE-1 is thought to be a therapeutic approach to AD. Measuring BACE-1 activity in biological samples would be useful to elucidate the mechanism of AD and for development of AD drugs.

METHODS

We developed a sensitive and specific activity assay for BACE-1. The assay is based on a genetically engineered proenzyme that is specifically activated by BACE-1. The resulting active enzyme is measured with a chromogenic substrate. The use of 2 coupled reactions produces a detection limit as low as 0.4 pmol/L.

RESULTS

The assay detected BACE-1 activity in extracts of human brain tissue as well as, unexpectedly, in human cerebrospinal fluid (CSF). Gel electrophoresis and Western blotting identified the BACE-1 present in CSF as a truncated soluble form of the originally membrane-bound BACE-1.

CONCLUSION

Detection of the soluble form of BACE-1 in CSF, a relatively easily accessible biological fluid, may be useful for monitoring the effects of drug candidates in vivo and may have diagnostic or prognostic applications.

Quantitative assessment of gastric antrum atrophy shows restitution to normal histology after Helicobacter pylori eradication

BACKGROUND/AIMS

Grading gastric mucosal atrophy in antrum biopsy specimens remains a controversial subject because of limitations in interobserver agreement. We previously described a reliable, quantitative method for grading atrophy of the corpus mucosa with excellent reproducibility and good correlation with the Sydney scores. The aims of the present study were to evaluate the applicability of this method for the grading of antral atrophy and to study the effect of Helicobacter pylori eradication on the antral mucosa.

METHODS

Antrum biopsy specimens were collected from 71 gastroesophageal reflux disease patients at baseline and after 3 and 12 months. After the first endoscopy, all subjects were treated with omeprazole 40 mg daily for 12 months. After randomization, 27 of the 48 H. pylori-positive patients additionally received eradication therapy. In 182 hematoxylin-eosin-stained specimens, which were of sufficient quality, the proportions (volume percentages) of glands (VPGL), stroma (VPS), infiltrate (VPI), and intestinal metaplasia in the glandular zone of the antrum mucosa were measured using a point-counting method. In these specimens, mucosal atrophy was assessed by two experienced gastrointestinal tract pathologists (E.B. and J.L.) according to the updated Sydney classification as either nonatrophic mucosa (n = 47) or as mild (n = 29), moderate (n = 50), or marked (n = 56) atrophy. In addition, a group of 23 cases with difficult-to-classify grades of atrophy were included.

RESULTS

The mean VPGL decreased with increasing Sydney grades of atrophy (p < 0.001), while the mean VPS and VPI increased (both p < 0.001). After H. pylori eradication, even the cases with the lowest VPGL regressed to normal levels.

CONCLUSIONS

Overall, a low VPGL correlates with increasing grades of antrum mucosal atrophy. The present data indicate that gastric mucosal atrophy is reversible, since almost all cases showed regression of VPGL after H. pylori eradication. The cases with difficult-to-classify grades of atrophy showed significantly lower VPGLs and higher VPIs than the reference cases.

Evidence for anti-inflammatory activity of statins and PPARα activators in human C-reactive protein transgenic mice in vivo and in cultured human hepatocytes in vitro

Inflammatory processes, aside from cholesterol, play a central role in atherogenesis. Human C-reactive protein (huCRP) signals systemic inflammation and independently predicts future cardiovascular risk. Cholesterol-lowering statins reduce atherosclerosis and plasma huCRP levels. Evidence is sought for a direct anti-inflammatory statin effect in vivo, independent of effects on plasma cholesterol and atherogenesis. The effect of atorvastatin and simvastatin on huCRP expression was studied in nonatherosclerotic huCRP transgenic mice and compared with another class of hypolipidemic drugs, peroxisome proliferator-activated receptor-alpha (PPARα) activators, notably fenofibrate and Wy14643. Like statins, PPARα activators combine antiatherosclerotic properties with huCRP-lowering effects. Dietary treatment with statins or PPARα activators decreased basal and interleukin-1β (IL-1β)-induced plasma huCRP levels independently of cholesterol lowering. These direct anti-inflammatory in vivo effects occurred at the transcriptional level and could be confirmed in cultured human liver slices and in human hepatoma cells transiently transfected with a huCRP promoter-driven luciferase reporter. A molecular rationale for the suppression of IL-1-induced huCRP transcription is provided by showing that statins and PPARα activators up-regulate IκBα protein expression. This results in a reduced nuclear translocation of p50-nuclear factor κ B (NFκB) and thereby decreased amounts of nuclear p50-NFκB∼CCAAT/enhancer binding protein beta (C/EBPβ) complexes, which determine the huCRP transcription rate. Our results provide conclusive evidence for a direct suppressive effect of statins and PPARα activators on huCRP expression independent of cholesterol lowering and atherogenesis. (Blood. 2004;103:4188-4194)

Genotyping of Helicobacter pylori in paraffin-embedded gastric biopsy specimens: relation to histological parameters and effects on therapy

OBJECTIVES

Colonization with Helicobacterpylori can lead to GI disease. Bacterial genotypes and host factors, such as acid production, can influence the progress of disease. We investigated H. pylori genotypes and histological parameters in the same paraffin-embedded gastric biopsy specimens.

METHODS

Paraffin-embedded antrum and corpus biopsy samples from 75 gastroesophageal reflux disease patients were histologically examined and tested for H. pylori vacA (s and m regions), cagA, and iceA genotypes. Patients were investigated at baseline (58 H. pylori positive and 17 H. pylori negative) and after treatment with omeprazole with or without additional antibiotic therapy.

RESULTS

Genotyping at baseline was complete in 52 (90%) of the 58 H. pylori positive patients. Multiple genotypes were detected in eight (14%) of these. Genotypes were highly consistent between antrum and corpus biopsy specimens at baseline and in follow-up samples. Genotypes from paraffin sections matched those from corresponding cultured strains in 10 selected cases. In the antrum, the degree of inflammation was associated with vacA s1 and cagA+ genotypes, and the degree of neutrophil activity was associated with the cagA+ genotype. In the corpus, the degree of inflammation was significantly associated with vacA s1, cagA+, and iceA1 genotypes and the degree of atrophy was associated with vacA s1, m1, and cagA+ genotypes, whereas the degree of neutrophil activity was associated with vacA s1 and cagA+ genotypes. vacA s2 and cagA-strains appeared more resistant to antibiotic therapy, irrespective of resistance to clarithromycin.

CONCLUSIONS

Our findings confirm the relevance of the H. pylori genotypes for the severity of gastric disease and the efficacy of antibiotic therapy.

Ptprj is a candidate for the mouse colon-cancer susceptibility locus Scc1 and is frequently deleted in human cancers

Only a small proportion of cancers result from familial cancer syndromes with Mendelian inheritance. Nonfamilial, 'sporadic' cancers, which represent most cancer cases, also have a significant hereditary component, but the genes involved have low penetrance and are extremely difficult to detect. Therefore, mapping and cloning of quantitative trait loci (QTLs) for cancer susceptibility in animals could help identify homologous genes in humans. Several cancer-susceptibility QTLs have been mapped in mice and rats, but none have been cloned so far. Here we report the positional cloning of the mouse gene Scc1 (Susceptibility to colon cancer 1) and the identification of Ptprj, encoding a receptor-type protein tyrosine phosphatase, as the underlying gene. In human colon, lung and breast cancers, we show frequent deletion of PTPRJ, allelic imbalance in loss of heterozygosity (LOH) and missense mutations. Our data suggest that PTPRJ is relevant to the development of several different human cancers.

Quantitative assessment of gastric corpus atrophy in subjects using omeprazole: a randomized follow-up study

OBJECTIVES

Atrophy of the gastric mucosa most frequently results from chronic Helicobacter pylori infection and is a risk factor for the development of gastric cancer. Profound acid suppression has been suggested to accelerate the onset of gastric mucosal atrophy. The aim of the present study was to evaluate the effects of H. pylori eradication and acid inhibition by omeprazole on gastric atrophy by means of quantitative analysis of tissue morphology.

METHODS

Corpus biopsy specimens were obtained during endoscopy in 71 gastroesophageal reflux disease (GERD) patients at baseline and after 3 and 12 months. A total of 48 subjects were H. pylori positive and 23 were H. pylori negative. All subjects received omeprazole 40 mg once daily after the first endoscopy for 12 months. After randomization, 27 of the 48 H. pylori-positive patients also received eradication therapy. In hematoxylin and eosin-stained slides the volume percentages of glands (VPGL), volume percentages of stroma (VPS), and volume percentages of infiltrate (VPI) were measured in the glandular zone of the mucosa. The results were evaluated by computerized morphometric analysis.

RESULTS

In the eradication group, the mean VPGL increased from 63.0% to 67.7% and 71.5% after 3 and 12 months (p < 0.001), respectively. The mean VPS and VPI decreased from 33.1% and 4.0% to 29.3% and 3.0% and to 26.4% and 2.1% (p < 0.001 and p = 0.04), respectively. Patients with the lowest VPGL at baseline showed the largest increases of VPGL after eradication treatment as compared to patients with high a VPGL at baseline. In the H. pylori-persistent group the VPI showed a significant increase (p = 0.01), and in the H. pylori-negative group VPGL increased significantly from 71.9% to 75.2% (p = 0.03) after 12 months.

CONCLUSIONS

Eradication of H. pylori leads to restitution of the volume percentage of glandular epithelium to normal levels, even during treatment with proton pump inhibitors. Whether this effect can also be seen in patients with marked atrophy needs further investigation.

Quantitative assessment of gastric corpus atrophy in subjects using omeprazole: a randomized follow-up study

OBJECTIVES

Atrophy of the gastric mucosa most frequently results from chronic Helicobacter pylori infection and is a risk factor for the development of gastric cancer. Profound acid suppression has been suggested to accelerate the onset of gastric mucosal atrophy. The aim of the present study was to evaluate the effects of H. pylori eradication and acid inhibition by omeprazole on gastric atrophy by means of quantitative analysis of tissue morphology.

METHODS

Corpus biopsy specimens were obtained during endoscopy in 71 gastroesophageal reflux disease (GERD) patients at baseline and after 3 and 12 months. A total of 48 subjects were H. pylori positive and 23 were H. pylori negative. All subjects received omeprazole 40 mg once daily after the first endoscopy for 12 months. After randomization, 27 of the 48 H. pylori-positive patients also received eradication therapy. In hematoxylin and eosin-stained slides the volume percentages of glands (VPGL), volume percentages of stroma (VPS), and volume percentages of infiltrate (VPI) were measured in the glandular zone of the mucosa. The results were evaluated by computerized morphometric analysis.

RESULTS

In the eradication group, the mean VPGL increased from 63.0% to 67.7% and 71.5% after 3 and 12 months (p < 0.001), respectively. The mean VPS and VPI decreased from 33.1% and 4.0% to 29.3% and 3.0% and to 26.4% and 2.1% (p < 0.001 and p = 0.04), respectively. Patients with the lowest VPGL at baseline showed the largest increases of VPGL after eradication treatment as compared to patients with high a VPGL at baseline. In the H. pylori-persistent group the VPI showed a significant increase (p = 0.01), and in the H. pylori-negative group VPGL increased significantly from 71.9% to 75.2% (p = 0.03) after 12 months.

CONCLUSIONS

Eradication of H. pylori leads to restitution of the volume percentage of glandular epithelium to normal levels, even during treatment with proton pump inhibitors. Whether this effect can also be seen in patients with marked atrophy needs further investigation.

Comparative analysis of human papillomavirus infections in cervical scrapes and biopsy specimens by general SPF(10) PCR and HPV genotyping

Human papillomavirus (HPV) can be detected by DNA amplification from clinical samples. The aim of the present study was to compare the HPV status in both cervical scrape and biopsy specimens obtained from 174 patients, using the recently developed broad spectrum SPF(10) PCR-LiPA method. The detection rate of HPV in these materials was determined and the spectrum of HPV genotypes was compared. Cervical scrapes and biopsy specimens were obtained, either on the same day (group I), or with an interval of up to almost 2 years (group II, mean interval 97 days, range 1-469 days). HPV DNA was amplified by SPF(10) PCR and detected in a microtitre plate hybridization assay. Of the HPV-positive cases, the genotype was determined by reverse hybridization of the same SPF(10) amplimer on a line probe assay (LiPA), discriminating between HPV genotypes 6, 11, 16, 18, 31, 33-35, 39, 40, 42-45, 51-54, 56, 58, 59, 66, 68, 70, and 74. The results showed that the detection rate and the spectrum of HPV genotypes in cervical scrapes and the corresponding biopsy specimens were highly comparable in both patient groups, even when multiple genotypes were present. In both groups, multiple HPV genotypes were more frequently detected in cervical scrapes than in the corresponding biopsy specimens. In conclusion, HPV infection can be diagnosed in cervical scrapes and biopsy specimens using the SPF(10) PCR-LiPA system. Analysis of cervical scrapes accurately reflects the spectrum of HPV genotypes in the patient's cervical region, even with a sampling interval between the cervical scrape and the biopsy specimen.

Rapid quantitative assessment of gastric corpus atrophy in tissue sections

BACKGROUND/AIMS

Grading of Helicobacter pylori induced atrophic gastritis using the updated Sydney system is severely limited by high interobserver variability. The aim of this study was to set up a quantitative test of gastric corpus mucosal atrophy in tissue sections and test its reproducibility and correlation with the Sydney scores of atrophy.

METHOD

Mucosal atrophy was assessed in 124 haematoxylin and eosin stained corpus biopsy specimens by two experienced gastrointestinal pathologists (EB, JL) according to the updated Sydney system as none (n = 33), mild (n = 33), moderate (n = 33), or pronounced (n = 25). In each specimen, the proportions of glands, stroma, infiltrate, and intestinal metaplasia in the glandular zone were measured as volume percentages using a point counting method. The optimal point sample size, intra-observer and interobserver reproducibility, discriminative power for degrees of atrophy, and correlations with H pylori status were evaluated.

RESULTS

Counting 400 points in 200 fields of vision provided the smallest sample size that still had excellent intra-observer and interobserver reproducibility (r > or = 0.96). Overall, the volume percentage of glands (VPGL), infiltrate (VPI), and stroma (VPS) correlated well with the Sydney scores for atrophy (p < or = 0.003). However, no differences were found between non-atrophic mucosa and mild atrophy. No correlation was found between age and either the Sydney grade of atrophy or the VPGL or VPS. In non-atrophic mucosa and mild atrophy, H pylori positive cases showed a significantly higher VPI than did H pylori negative cases. A lower VPGL was seen in H pylori positive cases than in H pylori negative cases in the mild atrophy group. VPS did not correlate with H pylori status within each grade of atrophy.

CONCLUSION

Point counting is a powerful and reproducible tool for the quantitative analysis of mucosal corpus atrophy in tissue sections. These data favour the combination of "none" and "mild" atrophy into one category, resulting in a three class grading system for corpus atrophy, when using the updated Sydney system.

Additive cytotoxic effect of cisplatin and X-irradiation on human glioma cell cultures derived from biopsy-tissue

PURPOSE

Investigation of the in vitro cytotoxic effect of X-rays, either alone or combined with cisplatin on early passage cell cultures derived from human glioblastoma multiforme biopsy tissue.

MATERIALS AND METHODS

Fresh tumour specimens from four patients were processed to cell cultures. The U373 glioma cell line was used as a reference. Early passage cell cultures were X-irradiated (0-8 Gy) either alone or in combination with cisplatin (0.5-1 microgram/ml). Cell survival was determined by either clonogenic assay or the colorimetric MTT assay. Survival curves were generated and mathematically analysed using the linear quadratic model, to obtain the radiosensitivity parameters alpha, beta, and SF2, i.e., the Surviving Fraction after 2 Gy.

RESULTS

Two patient-derived glioma cell cultures and the U373 cell line showed rather high SF2 values of 0.61-0.72 in the clonogenic assay, indicating relative high radiation resistance. Cisplatin alone (1 microgram/ml) reduced cell survival by 10-30% (n = 4). When combined with irradiation, a clear additive cytotoxic effect of cisplatin was demonstrated by the unaltered value of the alpha-parameter for reproductive cell death.

CONCLUSION

Cisplatin exerted an additive rather than radiosensitising cytotoxic effect in uncharacterised patient derived glioma cell cultures.

Helicobacter pylori-related and -non-related gastric cancers do not differ with respect to chromosomal aberrations

Gastric carcinogenesis is strongly associated with Helicobacter pylori infection, but the underlying genetic mechanisms are largely unknown. The aim of this study was to correlate chromosomal aberrations in gastric cancer to H. pylori status and its different strains, as well as to histological type and other clinico-pathological variables. DNA from 46 gastric cancers (male/female 35/11, age 27-85 years) was extracted from formaldehyde-fixed, paraffin-embedded material and tested for chromosomal gains and losses by comparative genomic hybridization (CGH). Chromosomal aberrations with frequencies of 20% or higher were considered to be non-random changes associated with gastric cancer. The mean number of chromosomal events per tumour was 9.7 (range 0-27), with a mean of 3.2 gains (range 0-16) and 6.5 losses (range 0-15). Gains were most frequently found at chromosomes 8q and 13q (24% and 26%, respectively). Losses were predominantly found on chromosome arms 2q, 9p, 12q, 14q, 15q, 16p, 16q, 17p, 17q, 19p, 19q, and 22q (22%, 30%, 43%, 22%, 33%, 50%, 28%, 50%, 39%, 33%, 39%, and 37%, respectively). Common regions of overlap narrowed down to 2q11-14, 8q23, 9p21, 12q24, 13q21-22, 14q24 and 15q11-15. The mean number of gains was higher in tumours with metastases than in localized tumours (4.1 vs. 1.9, p=0.04). Tumours with a loss at 17p showed a higher number of losses than tumours without a 17p loss (9. 5 vs. 4.7 on average, p<0.001). Neither H. pylori status (+, n=25; -, n=21) nor H. pylori strain was correlated to the total number of events or to any specific chromosomal aberration, nor were there differences between intestinal (n=30) and diffuse (n=15) cancers or any other clinico-pathological variable tested. In conclusion, a complex of chromosomal aberrations is involved in gastric cancer, but their pattern does not depend on H. pylori status or strain, nor on the histological type of the tumour. The exact biological meaning of these aberrations in carcinogenesis needs further clarification.

Parietal cell protrusions and fundic gland cysts during omeprazole maintenance treatment

Parietal cell protrusion (PCP), swelling and bulging of parietal cells, has been observed in the oxyntic mucosa of patients receiving omeprazole. The frequency of this event and the underlying mechanisms remain to be clarified. As such, it is unknown whether there is a relation with either serum gastrin or Helicobacter pylori infection, and whether PCP predisposes to the development of fundic gland cysts (FGC). We therefore investigated the development of PCP and FGC in gastroesophageal reflux disease (GERD) patients treated with omeprazole and correlated findings to duration of therapy, gastrin, and H pylori infection. In a randomized, double-blinded study, GERD patients were evaluated by endoscopy with biopsy sampling for histology and culture at baseline, and after 3 and 12 months' therapy with omeprazole 40 mg daily. H pylori-positive patients were randomized to additional eradication therapy or placebo antibiotics at baseline. All histological slides were scored blinded for time and outcome of culture for the presence of PCP and FGC. Fasting serum samples from all visits were used for gastrin measurements. The prevalence of PCP increased during omeprazole therapy from 18% at baseline to 79% and 86% at 3 and 12 months (P < .001, baseline v both 3 and 12 months). The prevalence of FGC increased from 8% to 17% and 35% (P < .05, baseline v 12 months). The prevalence of PCP and FGC did not differ among the H pylori-positive and H pylori-negative patients at baseline (PCP 16% v 20% and FGC 7% v 8%, respectively). Whereas H pylori eradication did not significantly affect development of PCP (P = .7), FGC developed significantly more often in the H pylori-eradicated patients when compared with persistent H pylori-positive patients (P < .05). PCP development was related to serum gastrin rise during therapy. In conclusion, PCP occurs in most patients within the first months of omeprazole treatment and is related to increased gastrin levels. FGC develops more gradually and is enhanced by H pylori eradication.

Effect of Helicobacter pylori eradication on chronic gastritis during omeprazole therapy

BACKGROUND

We have previously observed that profound acid suppressive therapy in Helicobacter pylori positive patients with gastro-oesophageal reflux disease is associated with increased corpus inflammation and accelerated development of atrophic gastritis.

AIM

To investigate if H pylori eradication at the start of acid suppressive therapy prevents the development of these histological changes.

PATIENTS/METHODS

In a prospective randomised case control study, patients with reflux oesophagitis were treated with omeprazole 40 mg once daily for 12 months. H pylori positive patients were randomised to additional double blind treatment with omeprazole 20 mg, amoxicillin 1000 mg and clarithromycin 500 mg twice daily or placebo for one week. Biopsy sampling for histology, scored according to the updated Sydney classification, and culture were performed at baseline, and at three and 12 months.

RESULTS

In the persistently H pylori positive group (n=24), active inflammation increased in the corpus and decreased in the antrum during therapy (p=0.032 and p=0.002, respectively). In contrast, in the H pylori positive group that became H pylori negative as a result of treatment (n=33), active and chronic inflammation in both the corpus and antrum decreased (p<or =0.0001). The decrease in active and chronic inflammation in the corpus differed significantly compared with the persistently H pylori positive group (both p=0.001). For atrophy scores, no significant differences were observed between H pylori eradicated and persistently H pylori positive patients within one year of follow up. No changes were observed in the H pylori negative control group (n=26).

CONCLUSIONS

H pylori eradication prevents the increase in corpus gastritis associated with profound acid suppressive therapy. Longer follow up is needed to determine if H pylori eradication prevents the development of atrophic gastritis.

Development and clinical evaluation of a highly sensitive PCR-reverse hybridization line probe assay for detection and identification of anogenital human papillomavirus

Human papillomavirus (HPV) can be detected by amplification of viral DNA. A novel PCR primer set generating a short PCR fragment (SPF PCR) was used for amplification of a fragment of only 65 bp from the L1 region and permitted ultrasensitive detection of a broad spectrum of HPV genotypes. The intra- and intertypic sequence variations of the 22-bp interprimer region of this amplimer were studied. Among 238 HPV sequences from GenBank and clinical specimens, HPV genotypes were correctly identified based on the 22-bp sequence in 232 cases (97.2%). Genotype-specific probes for HPV genotypes 6, 11, 16, 18, 31, 33 to 35, 39, 40, 42 to 45, 51 to 54, 56, 58, 59, 66, 68, 70, and 74 were selected, and a reverse hybridization line probe assay (LiPA) (the INNO-LiPA HPV prototype research assay) was developed. This LiPA permits the use of amplimers generated by the SPF as well as the MY 09/11 primers. The assay was evaluated with a total of 1, 354 clinical specimens, comprising cervical scrapes (classifications ranging from normal cytology to severe dyskaryosis) and formalin-fixed, paraffin-embedded cervical carcinoma samples. LiPA results were highly concordant with sequence analysis of the SPF amplimer, genotype-specific PCR, and sequence analysis of amplimers generated by MY 09/11 primers. The sensitivity of the SPF primers was higher than that of the GP5(+)/6(+) primers over a broad range of HPV types, especially when multiple HPV genotypes were present. In conclusion, the SPF LiPA method allows extremely sensitive detection of HPV DNA as well as reliable identification of HPV genotypes in both cervical smears and paraffin-embedded materials.

Trends in hospitalization and mortality from rotavirus disease in New Zealand infants

BACKGROUND

Rotavirus illness is associated with significant morbidity and mortality worldwide. We have examined trends in diarrheal disease in New Zealand children to determine the disease burden attributable to rotavirus and to estimate the proportion of hospitalizations preventable by vaccination.

METHODS

Hospital admissions data and laboratory records for 1994 to 1996, were obtained for children 0 to 4 years at four sites (serving -60% of the New Zealand population). Rotavirus disease burden was estimated using combined admissions and laboratory data. Severity of disease was estimated in a sample of 150 hospitalizations for rotavirus diarrhea, and the proportion of vaccine-preventable admissions was extrapolated. Mortality attributed to diarrheal causes was determined from national records for 1974 to 1993.

RESULTS

Between 1994 and 1996, 4436 children <5 years of age were hospitalized with diarrhea (1047/100000 children per year). Admissions associated with rotavirus were estimated at 1522 to 1535 (315 to 362/100000 annually). Infants between 6 and 17 months were most commonly affected (42% of all cases). More male children than female children were hospitalized (P < 0.001) and mean length of stay was calculated as 1.51 days (SD 2.35). Disease severity scoring revealed that 61.3 and 38.0% of admissions reviewed were severe and very severe, respectively. Deaths from diarrheal causes numbered 138 among children 0 to 4 years old for the 20-year period 1974 to 1993, with 18 deaths occurring between 1984 and 1993 (10 years).

CONCLUSION

Current vaccines control severe disease, suggesting that 72% of cases reviewed would be eligible for prevention. A full cost effectiveness analysis is required to demonstrate anticipated benefits of vaccination.

Fibroblast-Like Synoviocytes from Rheumatoid Arthritis Patients Have Intrinsic Properties of Follicular Dendritic Cells

The production of IgG rheumatoid factors in the inflamed synovium of many patients with rheumatoid arthritis (RA) implies that local sites exist where plasma cell precursors undergo isotype switching and affinity maturation by somatic mutation and selection. Lymphonodular infiltrates of the synovium-containing germinal centers (GCs), are candidates to fulfill such function in the rheumatoid patient. It has been suggested that these GCs are organized around, obviously ectopic, follicular dendritic cells (FDCs). The present study attempts to find out whether these putative FDCs 1) are specific for RA, 2) have the same phenotype and functional capacity as FDCs in lymphoid organs, and 3) may locally differentiate from fibroblast-like synoviocytes (FLS). Synovial biopsies from patients with RA versus non-RA, yet arthritic backgrounds, were compared. Cells with the FDC phenotype were found in both RA and non-RA tissues as well as in single cell suspensions thereof. When FLS were cultured in vitro, part of these cell lines could be induced with IL-1β and TNF-α to express the FDC phenotype, irrespective of their RA or non-RA background. By contrast, the FDC function, i.e., stable binding of GC B cells and switching off the apoptotic machinery in B cells, appeared to be the prerogative of RA-derived FLS only. The present data indicate that FDC function of FLS in RA patients is intrinsic and support the idea that synovial fibroblast-like cells have undergone some differentiation process that is unique for this disease.

Fibroblast-like synoviocytes from rheumatoid arthritis patients have intrinsic properties of follicular dendritic cells

The production of IgG rheumatoid factors in the inflamed synovium of many patients with rheumatoid arthritis (RA) implies that local sites exist where plasma cell precursors undergo isotype switching and affinity maturation by somatic mutation and selection. Lymphonodular infiltrates of the synovium-containing germinal centers (GCs), are candidates to fulfill such function in the rheumatoid patient. It has been suggested that these GCs are organized around, obviously ectopic, follicular dendritic cells (FDCs). The present study attempts to find out whether these putative FDCs 1) are specific for RA, 2) have the same phenotype and functional capacity as FDCs in lymphoid organs, and 3) may locally differentiate from fibroblast-like synoviocytes (FLS). Synovial biopsies from patients with RA versus non-RA, yet arthritic backgrounds, were compared. Cells with the FDC phenotype were found in both RA and non-RA tissues as well as in single cell suspensions thereof. When FLS were cultured in vitro, part of these cell lines could be induced with IL-1beta and TNF-alpha to express the FDC phenotype, irrespective of their RA or non-RA background. By contrast, the FDC function, i.e., stable binding of GC B cells and switching off the apoptotic machinery in B cells, appeared to be the prerogative of RA-derived FLS only. The present data indicate that FDC function of FLS in RA patients is intrinsic and support the idea that synovial fibroblast-like cells have undergone some differentiation process that is unique for this disease.

Immunohistochemical localization of somatostatin receptor sst2A in human rheumatoid synovium

OBJECTIVE

To identify the somatostatin receptor-expressing cells in rheumatoid synovium using a recently developed antiserum directed against the somatostatin receptor subtype 2A (sst2A).

METHODS

We carried out immunohistochemical studies of synovial biopsies from 7 patients with rheumatoid arthritis (RA) and one non-RA patient, using a rabbit polyclonal antiserum directed against sst2A and monoclonal antibodies directed against phenotypic markers.

RESULTS

SSt2A was expressed by the endothelial cells of the synovial venules but also by a subset of synovial macrophages.

CONCLUSION

The identification of somatostatin receptors on macrophages, which are thought to be important effector cells in RA, may offer mechanistic insights into the potential therapeutic effect of somatostatin (analogs) in RA.

Growth factor profiles of human gliomas. Do non-tumour cells contribute to tumour growth in glioma?

BACKGROUND

Growth factors play a role in proliferation and motility of malignant glial cells, through autocrine and paracrine mechanisms. Also, proliferation of non-tumour cells, e.g., endothelial cells, is likely to be controlled by growth factors. Several growth factors with their appropriate receptors can be involved, but studies on tissue specimens evaluating this in glioma are rare.

MATERIALS AND METHODS

We evaluated the potential role of Transforming growth factor-alpha (TGF-alpha) and Epidermal growth factor receptor (EGF-R), the Platelet-derived growth factor A- and B-chain (PDGF-A and PDGF-B) and its receptors (PDGFR alpha and PDGFR beta, and basic fibroblast growth factor (bFGF) in gliomas by analysing 86 of these tumours on the single cell level for the presence of immunoreactive growth factors and receptors. In a few cases double-staining experiments were done to directly visualize co-expression of factor and receptor.

RESULTS

Multiple growth factors and their receptors are present in astrocytic tumours; the higher the grade, the more growth factors and the more positive cells are found. Oligodendroglial tumours and pilocytic astrocytomas showed little expression. Autocrine and paracrine mechanisms were frequently possible in the astrocytic tumours, often more than one loop could be involved. Interestingly, it was also frequently possible that non-tumour cells produced a growth factor for which the tumour cells expressed the receptor.

CONCLUSIONS

Multiple growth factors appear to be involved in astrocytic tumours, with frequent autocrine and paracrine loops. Expression of these molecules seems to increase with increasing grade. The results argue for a contribution of non-tumour cells to the growth of a tumour.

Polymerase chain reaction for the detection of Helicobacter pylori in formaldehyde-sublimate fixed, paraffin-embedded gastric biopsies

To improve morphologic detail and immunohistochemical staining, mercuric chloride-containing fixatives such as formaldehyde-sublimate (FS) has been widely used as an alternative for neutral buffered formalin. FS-fixed, paraffin-embedded tissue, however, is considered to be an unreliable source of DNA. We used an adapted DNA-extraction method for FS-fixed, paraffin-embedded tissue. In all cases tested we obtained amplifiable DNA with polymerase chain reaction (PCR), after FS-fixation and after fixation in neutral buffered formalin as well. A PCR assay for the 16S-rRNA region of Helicobacter pylori was developed amplifying a fragment of 145 bp. The specificity of this PCR assay was tested on a range of different microorganisms. PCR was performed on 46 archival FS-fixed paraffin-embedded gastric biopsies. The results were compared with histologic examination and with immunohistochemical detection using a polyclonal antibody against H. pylori. Both PCR and immunohistochemistry are very sensitive methods for the detection of H. pylori. A PCR offers the possibility of additional subtyping in archival FS-fixed, paraffin-embedded tissue.

Malabsorption syndrome associated with ulceration of the stomach and small bowel caused by chronic intestinal ischemia in a patient with hyperhomocysteinemia

We describe a 39-year-old woman with an 8-month history of abdominal pain, diarrhea, and weight loss. Clinical and laboratory evaluation indicated the presence of a malabsorption syndrome. Endoscopy revealed multiple gastric ulcerations and an abnormal "picture" of the duodenal mucosa. At duodenal biopsy, necrosis confined to the distal parts of the enteric villi and a polymorphonuclear leukocyte response were found. Further evaluation revealed intestinal ischemia as a result of mesenteric atherosclerosis. After a revascularization procedure was performed, the symptoms disappeared. The macroscopic and microscopic picture of the bowel normalized. In our search for risk factors of atherosclerosis, we found a substantially increased basal plasma homocysteine concentration. This case suggests that hyperhomocysteinemia may have a causal role in the development of symptomatic, premature atherosclerosis of the mesenteric circulation.

Monoclonal antibodies against the human mannose receptor as a specific marker in flow cytometry and immunohistochemistry for macrophages

Recently we developed mouse monoclonal antibodies (mAb) against the isolated human 175-kDa mannose receptor. In the present study we tested whether these mAb are suitable for the detection of the mannose receptor on cultured macrophages using flow cytometry and on cells in human tissues using immunohistochemistry. Human monocytes did not react with the mAb in flow cytometry. Mannose receptor expression became detectable on monocytes cultured for 3 days (macrophages), and was maximal from 4 days onward. The mannose receptor was up-regulated on dexamethasone-treated (immunosuppressed) macrophages, and down-regulated on lipopolysaccharide-treated (activated) macrophages. Immunohistochemically the staining pattern of our mAb was compared with the marker of monocytes/macrophages KP1. In a bone marrow smear, only macrophages were stained with our mAb, whereas all myeloid cells were stained with KP1. In the thymus and lymph node, mannose receptor-positive branched cells (macrophages and dendritic cells) were detected in connective tissue, thymus cortex (not medulla), and in the T cell area (not the B cell area) of lymph nodes, whereas KP1 stained branched cells in all areas. It was concluded that the mAb are useful tools in flow cytometry and immunohistochemistry for the specific detection of cells expressing mannose receptor.

Increase of Helicobacter pylori-associated corpus gastritis during acid suppressive therapy: implications for long-term safety

OBJECTIVES

Helicobacter pylori causes chronic active gastritis with predominant localization in the gastric antrum. This predisposes to development of mucosal atrophy, intestinal metaplasia, and eventually, gastric cancer. The effects of acid suppression on H. pylori infection and associated gastritis are unclear. However rapid development of atrophic gastritis has been consistently observed in a number of studies during low acid output. We therefore studied the histological features of antrum and corpus of the stomach before and during acid suppressive therapy.

METHODS

Fifty patients with either reflux esophagitis (n = 21), benign gastric ulcer (six patients), gastric erosions (three patients), or duodenal ulcer (20 patients) were treated for 8 wk with omeprazole 40 mg o.d. Esophagogastroduodenoscopy was performed pre-entry and at 8 wk. Biopsy specimens were sampled from the antrum and corpus for histology and cultures.

RESULTS

Seventeen H. pylori-negative patients had no histological signs of active gastritis, before or after therapy. Thirty-three H. pylori-positive patients showed predominant colonization and associated inflammation in the antrum before therapy. After therapy, however, the infection predominantly affected the corpus. The inflammation and bacterial colonization in the antrum significantly decreased, leading to negative antral cultures in 61% (20 of 33 patients). In contrast, the inflammation of the corpus mucosa significantly increased despite stable bacterial counts.

CONCLUSIONS

We conclude 1) that H. pylori testing in patients on profound acid suppressive therapy should be performed on combined corpus and antral specimens, and 2) that omeprazole therapy leads to a strong increase in corpus gastritis, which may explain the observed development of corpus atrophy in a substantial number of patients after several years of continuous acid suppressive treatment. Therefore, we suggest that patients in need of long-term acid suppressive therapy should receive bacterial eradication therapy if they are H. pylori positive.

Serological parameters in assessment of degree of gastritis in healthy volunteers

This study was undertaken in healthy volunteers to determine the relation between serum levels of pepsinogen A, pepsinogen C, pepsinogen A:C ratio, and gastrin on the one hand and histology of the gastric mucosa on the other. The grade of gastritis was scored separately for antral and fundic mucosa by three different classifications: Whitehead, activity, and the Sydney score. Among 48 healthy volunteers studied, 17 were found to have gastritis according to the criteria of Whitehead. Fourteen of these 17 subjects with gastritis had H. pylori in gastric biopsies. In all 48 subjects serum pepsinogen A (r = 0.298-0.506; P < 0.01-P < 0.05), pepsinogen A:C ratio (r between -0.377 and -0.495; P < 0.001-P < 0.05) and gastrin (r = 0.38-0.695; P = 0.007-P < 0.01) were significantly correlated to the severity of both antral and body gastritis as assessed by all three classifications. In contrast, there was no significant correlation between serum pepsinogen C and any of the gastritis scores. When the 17 subjects with gastritis were analyzed separately, there were no correlations between the parameters studied and gastritis of the antrum. Regarding the corpus mucosa, serum PgA correlated significantly with the activity score (r = 0.520; P = 0.03), weakly with the Sydney score (r = 0.465; P = 0.06), but not with the Whitehead score. Serum PgC correlated with the Whitehead (r = 0.555; P = 0.02) and Sydney score (r = 0.523; P = 0.03), but only weakly with the activity score (r = 0.441; P = 0.08).(ABSTRACT TRUNCATED AT 250 WORDS)

Syntactic context effects on word recognition: a developmental study

In the present study, grammatical context effects on word recognition were examined among skilled and less skilled second and sixth grade readers. Of particular interest was how the word decoding ability may correlate with the grammatical context effect. For this purpose the rich case-marking system of the Finnish language was exploited. Recognition latencies for sentence-final nouns were measured as a function of their syntactic agreement with the preceding adjective. The naming and lexical decision tasks were used as critical measures. The study showed a clear syntactic context effect for each of the four experimental groups. The magnitude of the observed syntactic effect was substantially larger compared to earlier results. Furthermore, the effect emerged both in naming and lexical decision. In naming, less skilled 2nd grade decoders were more affected by grammatical incongruency than their more competent peers, whereas in lexical decision the skilled 6th graders differed from other groups by showing a smaller syntactic effect. The results are discussed in the light of Stanovich's interactive-compensatory model of word recognition.

Relation between IgG and IgA antibody titres against Helicobacter pylori in serum and severity of gastritis in asymptomatic subjects

AIMS

To investigate whether the absorbance index of IgG and IgA antibodies against Helicobacter pylori is related to a semiquantitative assessment of the density of H pylori colonisation in gastric biopsy specimens and to the severity of gastritis.

METHODS

The grade of gastritis was scored separately for antral and fundic mucosa using three different classifications. Serum IgA and IgG antibodies against H pylori were measured by ELISA. The density of gastric H pylori colonisation was graded semiquantitatively from 0 to 3.

RESULTS

Among 48 healthy volunteers studied, 17 were found to have gastritis according to Whitehead's criteria. H pylori was present in the biopsy specimens of 14 of 17 subjects with gastritis. The IgG H pylori antibody absorbance index was significantly (p < 0.05) correlated not only with the density of antral H pylori colonisation, but also with the degree of gastritis of the antrum, as assessed by the Whitehead score, activity, and the Sydney system (p < 0.05). The IgA H pylori antibody absorbance index was significantly correlated with the Whitehead score and Sydney system, but not with the activity score of the antrum or with the density of antral gastric H pylori infection. There were no significant correlations between the IgG H pylori antibody absorbance index and the gastritis scores of the fundus mucosa and the density of H pylori infection of the gastric body. The IgA H pylori antibody absorbance index was only significantly (p < 0.05) correlated with the density of H pylori colonisation and the Sydney system gastritis score of the corpus.

CONCLUSIONS

The serological absorbance index of IgG antibodies against H pylori is related to the severity of antral gastritis and the density of antral H pylori colonisation. Thus a high absorbance index of IgG antibodies against H pylori points to severe antral gastritis and dense H pylori colonisation of the antrum.

Value of counting colonic mucosal Ig-containing cells in the differential diagnosis of chronic inflammatory bowel disease

AIMS

To investigate whether counting cells containing immunoglobulin (Ig) subclass in colonic biopsy specimens of patients with chronic inflammatory bowel disease, in addition to conventional histological evaluation, can improve the differentiation of patients with Crohn's disease from those with ulcerative colitis.

METHODS

The colonic and rectal biopsy specimens of 40 patients with chronic inflammatory bowel disease, comprising 20 patients with Crohn's disease and 20 with ulcerative colitis, were used and sections were stained specifically for IgA, IgM, and IgG heavy chains using an indirect immune peroxidase method. The immunoglobulin subclass containing cells were counted using an ocular grid counting method in a light microscope. A linear stepwise discriminant analysis was performed on Ig subclass containing cell counts in combination with 16 reproducible histological features. The results of this discriminant analysis were compared with the results of the discriminant analyses in which only the histological features were used.

RESULTS

Applying stepwise discriminant analysis, two histological features (an excess of histiocytes in the lamina propria and the villous or irregular aspect of the mucosal surface) in combination with IgMax were selected as the most discriminatory parameters that distinguish Crohn's disease from ulcerative colitis. IgMmax was defined as the maximum value of the mean percentage of IgM containing cells over all the biopsy locations. The use of this combination resulted in a better classification in 20% of the patients with Crohn's disease and in 9% of the patients with ulcerative colitis compared with the use of histological features alone.

CONCLUSIONS

Morphometric enumeration of Ig subclass containing cells in colonic mucosal biopsy specimens has diagnostic value as a means of differentiating individual patients with Crohn's disease from those with ulcerative colitis.

Human papillomavirus and the three group metaphase figure as markers of an increased risk for the development of cervical carcinoma

In this study, the presence of atypical mitotic figures and human papilloma virus (HPV) genomes was related to the degree of cervical intraepithelial neoplasia (CIN) or microinvasive carcinoma (MIC) as found in 94 paraffin-embedded biopsies from cervical lesions. The results showed that the frequency of three group metaphase (TGM) figures, a special kind of atypical mitotic figure, as well as the presence of HPV 16 and 18 genomes increased with the degree of cervical intraepithelial neoplasia. TGM figures were observed in 24% of CIN2, up to 61% in CIN3 lesions, and in 83% of the microinvasive cervical carcinomas. HPV genomes were detected in 15% of CIN1, up to 75% in CIN3 lesions, and in 92% of the invasive carcinomas of the cervix. The combination of these two markers showed even a better association with a higher degree of cervical intraepithelial neoplasia. The results of these studies suggest that detection of particular HPV types, mainly HPV 16 and 18, and the presence of TGM figures can be considered as markers that indicate an increased risk for progression of cervical intraepithelial neoplasia to invasive carcinoma.

Flow cytometric DNA content of fresh tumor specimens using keratin-antibody as second stain for two-parameter analysis

Studies concerning flow cytometric assessed DNA content reveal problems in interpretating DNA histograms of tumor specimens. The main problems are histograms with a broad coefficient of variation in the G0/G1 fraction; a high G2M fraction and samples with a low percentage of tumor cells. Therefore, in the present study, 382 fresh tumor specimens of carcinomas were analysed routinely, double labeled with, on the one hand, propidium-iodide for assessing DNA content and, on the other, a monoclonal keratin-antibody for marking epithelial and tumor cells. Of the 311 tumor samples, using single parameter analysis 165 (54%) were classified as DNA aneuploid and 146 (46%) as DNA "euploid." By double parameter analysis, 224 (72%) samples were keratin positive and 87 (27%) keratin negative and, of the 224 keratin positive tumors, 175 (78%) were DNA aneuploid and 49 (22%) DNA euploid. The DNA histograms of single and double parameter analysis were compared and it was concluded that in 24 cases (11%) keratin labeling was necessary to recognize DNA aneuploidy. In another 23 (10%) cases, keratin labeling was helpful in assessing DNA aneuploidy. Finally when the results of the 311 samples were combined, 215 (68%) were scored as DNA aneuploid and 99 (32%) DNA euploid. Thus the overall gain in assessing DNA aneuploidy using the double labeling technique is 14%. In conclusion, it is shown that keratin labeling on fresh tumor cell suspensions of epithelial tumors is of additional value in establishing DNA content. Because single parameter DNA assessment is adequate in approximately 60% of the tested samples, the double labeling technique can be performed routinely, or after initial single parameter DNA assessment. Histograms having a broad CV and/or a high G2M are good candidates for the double labeling technique. Using this technique, DNA-content assessment becomes more reliable.

Histopathological evaluation of colonic mucosal biopsy specimens in chronic inflammatory bowel disease: diagnostic implications

In a prospective blind evaluation of multiple colonic mucosal biopsy specimens, 45 clinically well defined patients with chronic inflammatory bowel disease (21 Crohn's disease and 24 ulcerative colitis) and 16 control subjects (seven normal subjects and nine patients with diverticular disease) were studied to identify reproducible histopathological features which could distinguish chronic inflammatory bowel disease (CIBD) from non-CIBD and Crohn's disease from ulcerative colitis. Using kappa statistics 16 of 41 histological features were sufficiently reproducible for further stepwise discriminant analysis to differentiate between CIBD and non-CIBD, and between Crohn's disease and ulcerative colitis. Using the combination of three features (an increase of lymphocytes and plasma cells in the lamina propria, the presence of branching of crypts, and neutrophils in the crypt epithelium) we were able to distinguish CIBD from non-CIBD in 89% of the cases with high probability (p greater than 0.85). To separate Crohn's disease from ulcerative colitis three features (an excess of histiocytes in combination with a villous or irregular aspect of the mucosal surface and granulomas) had a high predictive value. Using these features 70% of Crohn's disease patients and 75% of ulcerative colitis patients were correctly classified with a high probability (p greater than 0.85). These findings indicate that the pathologist is dependent on the presence of only a few histological features for a reliable classification of Crohn's disease and ulcerative colitis.

Towards a quantitative grading of bladder tumors

The histological inspection of tumor tissue for the purpose of reporting a tumor grade is a problem of significant clinical importance. The grading by a pathologist is only partly reproducible due to vaguely defined, subjective criteria. In this article we describe and evaluate a set of measurable features that quantitate the differences in tumor tissue. Different aspects of the reproducibility of the measurements under varying conditions of image selection, focus, and noise have been investigated. Three hundred thirty-three images were digitized from 111 bladder tissue sections (4 microns thick, Feulgen stained), using the ICAS microscope-camera platform. A segmentation routine was developed to segment the images into nuclei and background without any user interaction. Size, shape, optical density, and texture features were measured on and among the objects found by this segmentation routine using the image analysis package Acuity. The results of the measurements showed that there is a significant quantitative difference between grade 1 and grade 3 tumors. Grade 2 tumors can be described as "in between grade 1 and grade 3" and falling somewhere on an increasing scale between grades 1 and 3. Grade 2 tumors do not seem to represent a statistically distinct population. The procedure described here is shown to be quite reproducible in the presence of noise, reasonably reproducible in the event of a modest amount of defocusing (with grade 3 tumors exhibiting the most sensitivity), and less reproducible in the context of which fields-of-view are chosen for analysis.

Detection of Chlamydia trachomatis in clinical specimens by the polymerase chain reaction

Sequences derived from the endogenous plasmid of Chlamydia trachomatis and from the genes coding for ribosomal 16S RNA of Chlamydia psittaci were used as primers and oligonucleotide probes for detection of chlamydiae by the polymerase chain reaction. The endogenous plasmid primers generated specific amplified products of 517 bp with all known Chlamydia trachomatis serovars. No specific products of Chlamydia psittaci and Chlamydia pneumoniae could be detected using these primers. With the rRNA primers specific amplified products of 208 bp were generated with Chlamydia psittaci, Chlamydia trachomatis and Chlamydia pneumoniae. No specific amplified products were detected with DNA isolated from a variety of microorganisms from the urogenital and the respiratory tract. Of 156 clinical specimens used for evaluation of the polymerase chain reaction, 26 were found to be positive for Chlamydia trachomatis on culture. All 26 culture positive samples were also found to be positive for Chlamydia trachomatis DNA by the polymerase chain reaction with both primer sets. Two culture negative samples were also found to be positive by this technique. The polymerase chain reaction thus seems to be a sensitive and reliable method for detection of Chlamydia trachomatis.

Serodiagnosis of respiratory syncytial virus (RSV) infection in children as measured by detection of RSV-specific immunoglobulins G, M, and A with enzyme-linked immunosorbent assay

The diagnostic value of an enzyme-linked immunosorbent assay for detection of respiratory syncytial virus (RSV)-specific immunoglobulin G (IgG), IgM, and IgA in sera from infants and children with proven RSV infection, from a control group, and from patients with symptoms of viral respiratory disease was analyzed. Compared to virus isolation and RSV antigen detection methods, the sensitivity of this assay was 87% and the specificity was 79%. For IgG alone, these were 45 and 92%, for IgM alone they were 48 and 92%, and for IgA alone they were 74 and 95%, respectively.

Favourable effect of detergent on antigen detection and comparison of enzyme linked detection systems in an ELISA for Chlamydia trachomatis

The influence of addition of detergents to the antigen on sensitivity of an ELISA for the detection of Chlamydia trachomatis was investigated. Of the detergents tested, only octyl-beta-d-glucopyranoside and sodiumdesoxycholate gave respectively a two- to fourfold and an eightfold increase in sensitivity. The effect was only present within a narrow range of detergent concentrations. The optimal detergent concentration was strongly dependent on the protein concentration in the antigen preparation. For optimal detection of the bound chlamydial antigen, enzyme and biotin labeled secondary antibodies were compared. The biotin labeled antibodies were combined with enzyme labeled streptavidin-biotin complex (SBC). Color development was obtained with both types of conjugates by using either o-phenylenediamine (OPD) or an enzyme amplification system. The best results were obtained with the SBC method and OPD.

Human papillomavirus detection in paraffin-embedded cervical carcinomas and metastases of the carcinomas by the polymerase chain reaction

The polymerase chain reaction (PCR) is used for human papillomavirus (HPV) detection in paraffin-embedded tissue. The specificity of the reaction is unaffected by the method of fixation used before embedding into paraffin. Five HPV 16, 18, 31, and 33 DNA in situ hybridization (DISH)-negative cervical carcinomas were subjected to the PCR. In two patients, HPV 16 DNA could be detected in the cervical squamous cell carcinomas and also in their lymph node metastases. One patient with an adeno-carcinoma of the cervix was found positive for HPV-18. A lymph node of this patient was HPV 18 positive as well. In the tumors of the remaining two patients, no HPV 16, 18, or 33 DNA was detected by the PCR. Both negative patients had cervical squamous cell carcinomas. One had a bladder metastasis, whereas the other had a lymph node metastasis and an additional distant metastasis in the lung. HPV DNA positivity in cervical carcinomas correlated with HPV prevalence in the metastases. This relationship can be of use for diagnostic purposes in the pathologic analysis of metastases.