Stroma AReactive Invasion Front Areas (SARIFA): a novel histopathologic biomarker in colorectal cancer patients and its association with the luminal tumour proportion

BACKGROUND

Stroma AReactive Invasion Front Areas (SARIFA) is a novel prognostic histopathologic biomarker measured at the invasive front in haematoxylin & eosin (H&E) stained colon and gastric cancer resection specimens. The aim of the current study was to validate the prognostic relevance of SARIFA-status in colorectal cancer (CRC) patients and investigate its association with the luminal proportion of tumour (PoT).

METHODS

We established the SARIFA-status in 164 CRC resection specimens. The relationship between SARIFA-status, clinicopathological characteristics, recurrence-free survival (RFS), cancer-specific survival (CSS), and PoT was investigated.

RESULTS

SARIFA-status was positive in 22.6% of all CRCs. SARIFA-positivity was related to higher pT, pN, pTNM stage and high grade of differentiation. SARIFA-positivity was associated with shorter RFS independent of known prognostic factors analysing all CRCs (RFS: hazard ratio (HR) 2.6, p = 0.032, CSS: HR 2.4, p = 0.05) and shorter RFS and CSS analysing only rectal cancers. SARIFA-positivity, which was measured at the invasive front, was associated with PoT-low (p = 0.009), e.g., higher stroma content, and lower vessel density (p = 0.0059) measured at the luminal tumour surface.

CONCLUSION

Here, we validated the relationship between SARIFA-status and prognosis in CRC patients and provided first evidence for a potential prognostic relevance in the subgroup of rectal cancer patients. Interestingly, CRCs with different SARIFA-status also showed histological differences measurable at the luminal tumour surface. Further studies to better understand the relationship between high luminal intratumoural stroma content and absence of a stroma reaction at the invasive front (SARIFA-positivity) are warranted and may inform future treatment decisions in CRC patients.

P05.05.B A new IDH-wildtype glioma subtype characterized by highly diffuse growth pattern, distinct epigenetic profile and relatively favorable prognosis

Background

DNA methylation profiling has emerges as a powerful approach to CNS tumor classification and the discovery of novel, molecularly distinct entities. With the release of the 12.5 version of the Heidelberg Brain Tumor Classifier, some unclassifiable cases can be assigned to novel methylation classes. We retrospectively reviewed our databases and identified 16 previously unclassifiable cases, all of which belong to the provisional methylation class “adult-type diffuse high-grade glioma, IDH-wildtype, subtype F (HGG_F)”.

Material and Methods

We clinically, radiologically and morphologically characterized 16 HGG_F cases and compared them to 347 glioblastomas. We additionally analyzed copy-number alterations and performed DNA exome sequencing.

Results

Median age at diagnosis of the 12 males and 4 females was 65 years. Upon initial diagnostic workup, specimens were classified as CNS tissue with reactive changes (n=3) or suspicious for the infiltration zone of a diffuse glioma (n = 13). None of the cases demonstrated endothelial proliferation or necrosis and 10/16 tumors had flat copy number profiles. Radiological characteristics were reminiscent of gliomatosis cerebri in eight cases and 9/9 cases had normal FET-PET scans. Whole-exome sequencing revealed genetic alterations frequently found in IDH-wildtype glioblastomas, including TERT promoter mutations in 11/14 (78.6%) and PIK3 mutations (10/14, 71.4%). Outcome was significantly better compared to TCGA IDH-wildtype glioblastomas with a median progression-free survival of 58 months and overall survival of 73 months (both p<0.001).

Conclusion

We provide evidence that TERT promoter mutations in diffusely infiltrating gliomas without further morphological or molecular signs of high-grade glioma should be interpreted in the context of the clinico-radiological presentation as well as epigenetic prolife and may not be suitable as standalone diagnostic marker for glioblastoma, IDH wildtype.

Artificial intelligence for detection of microsatellite instability in colorectal cancer-a multicentric analysis of a pre-screening tool for clinical application

BACKGROUND

Microsatellite instability (MSI)/mismatch repair deficiency (dMMR) is a key genetic feature which should be tested in every patient with colorectal cancer (CRC) according to medical guidelines. Artificial intelligence (AI) methods can detect MSI/dMMR directly in routine pathology slides, but the test performance has not been systematically investigated with predefined test thresholds.

METHOD

We trained and validated AI-based MSI/dMMR detectors and evaluated predefined performance metrics using nine patient cohorts of 8343 patients across different countries and ethnicities.

RESULTS

Classifiers achieved clinical-grade performance, yielding an area under the receiver operating curve (AUROC) of up to 0.96 without using any manual annotations. Subsequently, we show that the AI system can be applied as a rule-out test: by using cohort-specific thresholds, on average 52.73% of tumors in each surgical cohort [total number of MSI/dMMR = 1020, microsatellite stable (MSS)/ proficient mismatch repair (pMMR) = 7323 patients] could be identified as MSS/pMMR with a fixed sensitivity at 95%. In an additional cohort of N = 1530 (MSI/dMMR = 211, MSS/pMMR = 1319) endoscopy biopsy samples, the system achieved an AUROC of 0.89, and the cohort-specific threshold ruled out 44.12% of tumors with a fixed sensitivity at 95%. As a more robust alternative to cohort-specific thresholds, we showed that with a fixed threshold of 0.25 for all the cohorts, we can rule-out 25.51% in surgical specimens and 6.10% in biopsies.

INTERPRETATION

When applied in a clinical setting, this means that the AI system can rule out MSI/dMMR in a quarter (with global thresholds) or half of all CRC patients (with local fine-tuning), thereby reducing cost and turnaround time for molecular profiling.

Ambient particulate matter and biomass burning: an ecological time series study of respiratory and cardiovascular hospital visits in northern Thailand

BACKGROUND

Exposure to particulate matter (PM) emitted from biomass burning is an increasing concern, particularly in Southeast Asia. It is not yet clear how the source of PM influences the risk of an adverse health outcome. The objective of this study was to quantify and compare health risks of PM from biomass burning and non-biomass burning sources in northern Thailand.

METHODS

We collected ambient air pollutant data (PM with a diameter of < 10 μm [PM10], PM2.5, Carbon Monoxide [CO], Ozone [O3], and Nitrogen Dioxide [NO2]) from ground-based monitors and daily outpatient hospital visits in Thailand during 2014-2017. Outpatient data included chronic lower respiratory disease (CLRD), ischaemic heart disease (IHD), and cerebrovascular disease (CBVD). We performed an ecological time series analysis to evaluate the association between daily air pollutants and outpatient visits. We used the 90th and 95th percentiles of PM10 concentrations to determine days of exposure to PM predominantly from biomass burning.

RESULTS

There was significant intra annual variation in PM10 levels, with the highest concentrations occurring during March, coinciding with peak biomass burning. Incidence Rate Ratios (IRRs) between daily PM10 and outpatient visits were elevated most on the same day as exposure for CLRD = 1.020 (95% CI: 1.012 to 1.028) and CBVD = 1.020 (95% CI: 1.004 to 1.035), with no association with IHD = 0.994 (95% CI: 0.974 to 1.014). Adjusting for CO tended to increase effect estimates. We did not find evidence of an exposure response relationship with levels of PM10 on days of biomass burning.

CONCLUSIONS

We found same-day exposures of PM10 to be associated with certain respiratory and cardiovascular outpatient visits. We advise implementing measures to reduce population exposures to PM wherever possible, and to improve understanding of health effects associated with burning specific types of biomass in areas where such large-scale activities occur.

Analysis of CIC-associated CpG island methylation in oligoastrocytoma

AIMS

Combined deletion of the whole chromosomal arms 1p and 19q is a frequent event in oligodendroglial tumours. Recent identification of recurrent mutations in CIC on 19q and FUBP1 on 1p and their mutational patterns suggest a loss of function of the respective proteins. Surprisingly, oligoastrocytomas harbouring identical genetic characteristics regarding 1p/19q codeletion and frequent IDH1/2 mutations have been shown to carry CIC mutations in a significantly lower number of cases. The present study investigates whether epigenetic modification may result in silencing of CIC.

METHODS

As IDH1/2 mutation-mediated DNA hypermethylation is a prominent feature of these tumours, we analysed a set of CIC wild-type oligoastrocytomas and other diffuse gliomas with regard to 1p/19q status for presence of CIC-associated CpG island methylation by methylation-specific PCR.

RESULTS

Both methylation-specific PCR and subsequent bisulphite-sequencing of selected cases revealed an unmethylated status in all samples.

CONCLUSION

Despite the hypermethylator phenotype in IDH1/2 mutant tumours and recent detection of gene silencing particularly on retained alleles in oligodendroglial tumours, hypermethylation of CIC-associated CpG islands does not provide an alternative mechanism of functional CIC protein abrogation.

Hemangiopericytomas grade II are not benign tumors

BACKGROUND

Hemangiopericytomas (HPs) of the central nervous system are rare tumors and afflicted with a high propensity of recurrences and metastases. Histopathologically, HPs correspond to differentiated (WHO grade II) and anaplastic (WHO grade III) tumors. With respect to the available literature and our own experiences, the aggressiveness, especially of differentiated grade II HPs, seems to be underestimated.

METHODS

Thus, in this retrospective study, we describe tumor behavior and examined the effect of radio- and chemotherapy on tumor control with respect to the WHO classification of grade II and III neoplasms. This study consists of 15 patients with cerebral (n = 10) and spinal (n = 5) HPs.

RESULTS

Seven HPs were histopathologically classified as grade II and eight as anaplastic grade III tumors. Complete surgical resection could be achieved in 60% of cerebral and in 25% of spinal HPs. In total, local recurrences occurred in 20% of patients within 17.3 months after the primary operation. Recurrences occurred both from differentiated (n = 1) and anaplastic (n = 2) neoplasms. Treatment comprised re-operation followed by radio- and chemotherapy. Pointing out the importance of the extent of surgical resection, in this study, we could not detect a single patient showing any recurrences or systemic metastases after complete surgical resection of grade II HPs. During primary diagnostics, four patients showed systemic metastases. Although these tumors could be controlled via surgery, systemic metastases appeared in further four patients within 60.4 months. Interestingly, two of them were classified as differentiated tumors (WHO grade II). To control tumor progress, radiotherapy seemed to be partially effective. On the other hand, however, chemotherapy did not show any effect on tumor control. With respect to these results, screening investigations seem to be indispensable and are highly recommended during primary diagnostics and after the appearance of recurrences or metastases, independent of the histopathological staging of the tumor.

CONCLUSION

With respect to our results, radical surgical resection offers the best treatment option to control tumor progress. In case of subtotal resection or histopathologically diagnosed anaplasia (WHO III), radiotherapy seems to be indicated; however, chemotherapy did not show effectiveness to control tumor progress.

Use of a single bipolar electrode in the posterior arytenoid muscles for bilateral monitoring of the recurrent laryngeal nerves in thyroid surgery

The aims were to assess the technical feasibility of using a single electrode in the posterior arytenoid muscles (PAM) for intraoperative monitoring of the recurrent laryngeal nerve (RLN) in thyroid surgery, to validate the new method against the insertion of electrodes placed in the vocal cord muscle, and to report the results of the clinical application of the new concept. A total of 52 patients were enrolled. The handling and safety of RLN monitoring was tested by simultaneous registration of the EMG response from vocal fold electrodes and PAM electrodes. Acoustically and electromyographically we found nearly the same values for the arytenoid muscles as for the vocal folds, although the signals taken from the vocal folds were slightly stronger. PAM recording using a single bipolar electrode is technically feasible and as reliable compared to the standard vocal cord monitoring.

Differential mobility separation of ions using a rectangular asymmetric waveform

The performance of a planar differential mobility spectrometer (DMS) is investigated when operated in air at ambient pressure and driven by a rectangular asymmetric waveform, limited to frequencies of <1.2 MHz and voltage pulse amplitudes of <1 kV with steep rise times of the order of approximately 15 ns. Independent control of frequency, voltage pulse amplitude, and duty cycle allow for characterizing the DMS in terms of transmission, resolution and separation. The tradeoff between sensitivity and resolution and the effect of duty cycle on instrument performance are demonstrated experimentally. The dependence of ion mobility on the magnitude of the electric field determines the displacement of ions measured by the DC compensation voltage as a function of the duty cycle. Optimum values for the duty cycle exist for the separation of A- and C-type ions, while, B-type ions exhibit a more complex behavior. An analytical expression for describing the effect of duty cycle on the separation of the ions, determined by variations in the compensation voltage, is developed and compared to experimental results obtained in air below 75 Td using estimated alpha parameters for a set of ketones. In this context, errors associated with the calculation of alpha parameters using polynomials of even powers are highlighted.

Living at high altitude and risk of hospitalisation for atopic asthma in children: results from a large prospective birth-cohort study

BACKGROUND

Asthma is among the most common chronic diseases in childhood and is steadily increasing in prevalence. Better characterisation of factors that determine the risk of hospitalisation for atopic asthma in childhood may help design prevention programmes and improve our understanding of disease pathobiology. This study will focus on the altitude of residence.

METHODS

This is an ongoing prospective birth-cohort study that enrolled all live-born infants in the Tyrol. Between 1994 and 1999, baseline data were collected for 33 808 infants. From 2000 to 2005, all children hospitalised for atopic asthma at the age of > or =6 years (n = 305) were identified by a careful search of hospital databases. Disease status was ascertained from the typical medical history, a thorough examination and proof of atopy.

RESULTS

Living at higher altitude was associated with an enhanced risk of hospitalisation for atopic asthma (multivariate RRs (95% confidence interval 2.08 (1.45 to 2.98) and 1.49 (1.05 to 2.11) for a comparison between altitude categories > or =1200 m and 900-1199 m versus <900 m; p<0.001). This finding applied equally to hospital admissions in spring, summer, autumn and winter. When altitude of residence was analysed as a continuous variable, the risk for asthma hospitalisation increased by 7% for each 100-m increase in altitude (p = 0.013).

CONCLUSIONS

This large prospective study shows a significant association between the risk of hospitalisation for atopic asthma and altitude of residence between 450 and 1800 m. The underlying mechanisms remain to be elucidated, but it is tempting to speculate about a role for altitude characteristics such as the decline in outdoor temperature and air humidity and increase in ozone levels, which may trigger airway hyper-responsiveness and attenuate lung function.

Do wet diapers induce arousals in sleeping infants?

AIM

To find out whether simulated bladder voiding was able to induce arousals in sleeping infants.

METHODS

Polygraphic recordings were performed in 34 infants and voiding was simulated by administering water into the diaper.

RESULTS

Heart rate, respiratory frequency and electroencephalogram frequency did not change significantly during this procedure. Furthermore, simulated voiding was unable to cause an awakening or to induce body movements in sleeping infants.

CONCLUSION

Simulated voiding was unable to induce arousals.

Downregulation of RUNX3 and TES by hypermethylation in glioblastoma

Glioblastoma, the most aggressive and least treatable form of malignant glioma, is the most common human brain tumor. Although many regions of allelic loss occur in glioblastomas, relatively few tumor suppressor genes have been found mutated at such loci. To address the possibility that epigenetic alterations are an alternative means of glioblastoma gene inactivation, we coupled pharmacological manipulation of methylation with gene profiling to identify potential methylation-regulated, tumor-related genes. Duplicates of three short-term cultured glioblastomas were exposed to 5 microM 5-aza-dC for 96 h followed by cRNA hybridization to an oligonucleotide microarray (Affymetrix U133A). We based candidate gene selection on bioinformatics, reverse transcription-polymerase chain reaction (RT-PCR), bisulfite sequencing, methylation-specific PCR and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Two genes identified in this manner, RUNX3 and Testin (TES), were subsequently shown to harbor frequent tumor-specific epigenetic alterations in primary glioblastomas. This overall approach therefore provides a powerful means to identify candidate tumor-suppressor genes for subsequent evaluation and may lead to the identification of genes whose epigenetic dysregulation is integral to glioblastoma tumorigenesis.

[Wound botulism in heroin addicts in Germany]

HISTORY AND ADMISSION FINDINGS

5 heroin addicts (aged 31-44 years; 1 female, 4 men) presented with a history of blurred vision and diplopia followed by dysarthria. 3 of the patients also developed respiratory failure requiring long-term ventilatory support. Physical examination revealed cranial nerve deficits and abscesses at injection sites in 3 of them.

DIAGNOSIS

In 4 patients wound botulism was diagnosed on the basis of symptoms, course of the illness and response to specific treatment. Clostridium botulinum was grown from wound swab in one patient.

TREATMENT AND COURSE

Two of the patients, having been injected with antitoxin immediately after admission, were discharged almost symptom-free after only a few days. Adjuvant antibiotics and, in 3 patients, surgical débridement of the abscesses were needed.

CONCLUSIONS

Progressive cranial nerve pareses in addicts who inject drugs intravenously or intramuscularly should raise the suspicion of wound botulism and require hospitalization. While indirect demonstration of toxin supports the diagnosis, false-negative results are common.

[Long-lasting, refractory headache after bilateral dissection of the internal carotid artery]

Headache is usually the first and the most frequent symptom of cervicocephalic arterial dissection. Besides headache ipsilateral Horner's syndrome, cranial nerve palsies, or pulsatile tinnitus are observed. Serious complications of arterial dissection are ischemic strokes, which mostly occur later in the course of time. We report on a patient with spontaneous bilateral carotid artery dissection, who suffered from atypically prolonged, severe, and refractory headache. High-dose administration of nonsteroidal anti-inflammatory drugs as well as opioids were ineffective. Pain relief was only achieved after a 3-day course of corticosteroids (100 mg methylprednisolone/day).

Minor neurological dysfunction, cognitive development, and somatic development at the age of 3 to 7 years after dexamethasone treatment in very-low birth-weight infants

The objective of this study was to assess minor neurological dysfunction, cognitive development, and somatic development after dexamethasone therapy in very-low-birthweight infants. Thirty-three children after dexamethasone treatment were matched to 33 children without dexamethasone treatment. Data were assessed at the age of 3-7 years. Dexamethasone was started between the 7th and the 28th day of life over 7 days with a total dose of 2.35 mg/kg/day. Exclusion criteria were asphyxia, malformations, major surgical interventions, small for gestational age, intraventricular haemorrhage grades III and IV, periventricular leukomalacia, and severe psychomotor retardation. Each child was examined by a neuropediatrician for minor neurological dysfunctions and tested by a psychologist for cognitive development with a Kaufman Assessment Battery for Children and a Draw-a-Man Test. There were no differences in demographic data, growth, and socio-economic status between the two groups. Fine motor skills and gross motor function were significantly better in the control group (p<0.01). In the Draw-a-Man Test, the control group showed better results (p<0.001). There were no differences in development of speech, social development, and the Kaufman Assessment Battery for Children. After dexamethasone treatment, children showed a higher rate of minor neurological dysfunctions. Neurological development was affected even without neurological diagnosis. Further long-term follow-up studies will be necessary to fully evaluate the impact of dexamethasone on neurological and cognitive development.

Can we continue research in splenectomized dogs? Mycoplasma haemocanis: old problem--new insight

We report the appearance of a Mycoplasma haemocanis infection in laboratory dogs, which has been reported previously, yet, never before in Europe. Outbreak of the disease was triggered by a splenectomy intended to prepare the dogs for a hemorrhagic shock study. The clinical course of the dogs was dramatic including anorexia and hemolytic anemia. Treatment included allogeneic transfusion, prednisone, and oxytetracycline. Systematic follow-up (n = 12, blood smears, antibody testing and specific polymerase chain reaction) gives clear evidence that persistent eradication of M. haemocanis is unlikely. We, therefore, had to abandon the intended shock study. In the absence of effective surveillance and screening for M. haemocanis, the question arises whether it is prudent to continue shock research in splenectomized dogs.

Technique for the direct measurement of DC-like magnetic biosignals demonstrated by the cold reflex of the abdomen

Very low frequency dc-like signals, such as the cold reflex, could only be measured up to now by moving the subject repeatedly, up to the magnetic detector. PTB's novel magnetically shielded room BMSR 2, together with a low noise 16 channel SQUID magnetometer, allow the recording of dc-like signals without moving the subject; these are direct measurements. The total observed magnetic drifts are limited by 1/f-noise and external disturbances to a value below 6 pT/h. The measurement is continuous in time, therefore provides frequency resolution from dc to several kHz. This allows us to also observe the changing pattern between two different static magnetic states. As an example, the measurement of the cold reflex of the abdomen is shown and discussed. Not only the expected cold reflex, but other periodic and spontaneous signals from the human body can be seen with this method.

No evidence of hSNF5/INI1 point mutations in choroid plexus papilloma

Choroid plexus carcinomas (CPC) have been shown to carry mutations in the hSNF5/INI1 gene on chromosomal arm 22q11.2. A recent study on choroid plexus papillomas (CPP) and CPC revealed frequent losses of chromosomal portions on the long arm of chromosome 22 (-22q). The region harbouring hSNF5/INI1 was affected in 47% of the CPP and 73% of the CPC, respectively. -22q occurred more frequently in adult than in infantile CPP suggesting different pathogenetic pathways for these tumours. These findings may indicate a potential tumour suppressor gene function of hSNF5/INI1 in a subset of choroid plexus tumours. In order to examine its potential role in the pathogenesis of choroid plexus tumours, we analysed exons 1-9 of hSNF5/INI1 by SSCP analysis in a series of 21 formalin-fixed and paraffin-embedded CPP. No alterations in migratory patterns were detected. These data indicate that somatic point mutations of hSNF5/INI1 do not play a role in the pathogenesis of CPP and that CPP and CPC may arise by two different molecular pathways.

[Molecular pathology in hereditary colorectal cancer. Recommendations of the Collaborative German Study Group on hereditary colorectal cancer funded by the German Cancer Aid (Deutsche Krebshilfe)]

Although twin studies indicate that inherited genetic factors contribute to about 35% of colorectal cancers (CRC), the exact genetic background has currently been elucidated in only 5-10% of cases. These comprise several hereditary cancer predisposition syndromes that present with a high number of syn- or metachronous neoplasms within an affected person and/or family. Many of these tumors exhibit typical histopathological changes. In general, one should discriminate between cancer syndromes associated with adenomatous and non-adenomatous (i.e., hamartomatous) polyps, the latter being quite rare. The patient's age often serves as a substantial hint to hereditary cancer. The next step of diagnostic work-up includes analysis of microsatellite instability (MSI) together with immunohistochemical detection of a loss of expression in one of the most frequently affected mismatch repair genes (MSH2, MSH6; MLH1, PMS2). Finally, the molecular demonstration of a gene mutation in the blood or germline is the most expensive and tedious procedure. This requires a signed informed consent from the patient after appropriate genetic counseling.

Simple invasive fixation device for fractionated stereotactic LINAC based radiotherapy

BACKGROUND

The aim of this study was to develop a relocatable fixation device for linear accelerator (LINAC) based fractionated stereotactic radiotherapy.

METHOD

The device consists of a CT- and MRI-compatible stereotactic frame, monocortical titan bone screws, four frame-posts with a lock for the fixation pins and a modified head clamp with additional arms that allows the exact and rigid placement of the frame in the desired final position prior to the final placement of the bone screws. By simply disconnecting the lock from the posts, the frame can be dismounted after treatment planning and after each treatment session. The accuracy of reposition was assessed prospectively, using phantom studies and also by comparison of isocenter movements during fractionated radiotherapy in 10 patients with an intracranial lesion.

FINDINGS

No adverse events were seen after the surgical procedure and the screws were well tolerated throughout the course of treatment. The mean isocenter shifts observed during phantom reposition studies were x=0.05 mm, y=-0.32 mm, z=0.18 mm and the mean isocenter shifts during fractionated treatment were x=0.67 mm, y=0.65 mm, z=0.44 mm.

INTERPRETATION

This new fixation device provides excellent accuracy of reposition during stereotactic radiotherapy. It appears superior to non-invasive, mask fixation techniques. Safety margins as small as 1-1.5 mm may therefore be sufficient for this method of stereotactic radiotherapy.

Investigation of bax, bcl-2, bcl-x and p53 gene polymorphisms in multiple sclerosis

Clinical course, outcome, radiological features, severity, and histopathology are heterogenous in multiple sclerosis (MS). Since MS is considered to be a polygenic disease, the genetic background may at least partly be responsible for this variability. Some MS cases are histopathologically characterized by a dramatic oligodendrocyte loss that is in part caused by apoptosis. A dysregulated apoptotic elimination of self-reactive T cells may also contribute to disease susceptibility. To analyze genetic differences in the apoptosis regulating factors bcl-2, bax, bcl-x and p53 we investigated polymorphisms of these genes in 105 patients with a relapsing remitting disease course and 99 controls by PCR-SSCP and direct sequencing. We identified so far unpublished sequence alterations in the promotor region of the bxl-x gene, in exon 7 of the p53 gene, and in exon 1 of the bax gene. No differences were observed between MS patients and controls. Additional known polymorphisms were found in intron 3 of the bax gene and in exon 6 of the p53 gene. No significant differences in the frequency of gene sequence variations were found between MS patients and controls. The apoptosis genes studied here therefore appear less likely to be important effector genes in MS.

Articular cartilage repair using a tissue-engineered cartilage-like implant: an animal study

OBJECTIVE

Because articular cartilage has limited ability to repair itself, treatment of (osteo)chondral lesions remains a clinical challenge. We aimed to evaluate how well a tissue-engineered cartilage-like implant, derived from chondrocytes cultured in a novel patented, scaffold-free bioreactor system, would perform in minipig knees with chondral, superficial osteochondral, and full-thickness articular defects.

DESIGN

For in vitro implant preparation, we used full-thickness porcine articular cartilage and digested chondrocytes. Bioreactors were seeded with 20x10(6) cells and incubated for 3 weeks. Subsequent to culture, tissue cartilage-like implants were divided for assessment of viability, formaldehyde-fixed and processed by standard histological methods. Some samples were also prepared for electron microscopy (TEM). Proteoglycans and collagens were identified and quantified by SDS-PAGE gels. For in vivo studies in adult minipigs, medial parapatellar arthrotomy was performed unilaterally. Three types of defects were created mechanically in the patellar groove of the femoral condyle. Tissue-engineered cartilage-like implants were placed using press-fit fixation, without supplementary fixation devices. Control defects were not grafted. Animals could bear full weight with an unlimited range of motion. At 4 and 24 weeks postsurgery, explanted knees were assessed using the modified ICRS classification for cartilage repair.

RESULTS

After 3-4 weeks of bioreactor incubation, cultured chondrocytes developed a 700-microm- to 1-mm-thick cartilage-like tissue. Cell density was similar to that of fetal cartilage, and cells stained strongly for Alcian blue and safranin O. The percentage of viable cells remained nearly constant (approximately 90%). Collagen content was similar to that of articular cartilage, as shown by SDS-PAGE. At explantation, the gross morphological appearance of grafted defects appeared like normal cartilage, whereas controls showed irregular fibrous tissue covering the defect. Improved histologic appearance was maintained for 6 months postoperatively. Although defects were not always perfectly level upon implantation at explanation the implant level matched native cartilage levels with no tissue hypertrophy. Once in place, implants remodelled to tissues with decreased cell density and a columnar organization.

CONCLUSIONS

Repair of cartilage defects with a tissue-engineered implant yielded a consistent gross cartilage repair with a matrix predominantly composed of type II collagen up to 6 months after implantation. This initial result holds promise for the use of this unique bioreactor/tissue-engineered implant in humans.

In vivo detection of postictal perturbations of cerebral metabolism by use of proton MR spectroscopy: preliminary results in a canine model of prolonged generalized seizures

BACKGROUND AND PURPOSE

Biochemical studies of seizures in patients and laboratory animals have monitored postictal perturbations in cerebral metabolism with either invasive techniques or with such noninvasive techniques as nuclear medicine, MR imaging, in vivo phosphorus MR spectroscopy (MRS), and in vivo proton MRS at field strengths of 1.5 T or above. We investigated postictal metabolic changes in a generalized seizure model with in vivo proton MRS at 0.5 T, in which the combination of glutamate and glutamine resonances (denoted glx) can be modeled as a singlet.

METHODS

Five adult mongrel dogs underwent control and postictal experiments in which single-voxel proton MR spectra were obtained from the right frontal lobe cortex with a point-resolved spectroscopy technique approximately every 20 minutes for 3 hours. N-acetylaspartate (NAA), glx, and creatine (Cr) were quantified in absolute millimolar units with a cerebral water-referenced algorithm. Inter- and intrasubject differences in mean metabolite concentrations collected throughout the 3-hour period were compared using an unpaired, two-tailed Student's t test at a.05 level of significance.

RESULTS

We found a significant increase (15.4%) in the postictal intersubject mean glx concentration, as well as a 23.7% postictal decrease in the intersubject mean Cr concentration. A trend toward a subtle decrease in postictal intersubject mean NAA concentration was not statistically significant. We also observed a substantial qualitative increase in the combination of postictal lactate and free fatty acid peaks.

CONCLUSIONS

The glx, NAA, lactate, and free fatty acid results are in general agreement with previous studies of postictal perturbations in cerebral metabolism measured with invasive biochemical or noninvasive high-field-strength in vivo MRS detection assays. Given a high sensitivity for glx at 0.5 T relative to 1.5 T, further studies of postictal mesial temporal lobe structures are warranted in chronic animal preparations that model temporal lobe epilepsy.

Different patterns of beta-catenin expression in gastric carcinomas: relationship with clinicopathological parameters and prognostic outcome

AIMS

The cadherin-catenin complex is known to play a critical role in maintenance of cell adhesion. Additionally beta-catenin (beta-ct) can also take part in signal transduction and nuclear beta-ct expression could be correlated with poor prognosis in several malignancies. Since, in gastric cancer, this role of beta-ct is still uncertain, we investigated the expression pattern of beta-ct as well as the possible prognostic role.

METHODS AND RESULTS

beta-catenin expression was immunohistochemically investigated in a retrospective series of 401 R0-resected gastric carcinomas. Out of these cases, 54 tumours (13.5%) revealed a preserved membranous beta-ct expression similar to that in normal gastric mucosa. In 80 tumours beta-ct expression was moderately reduced and in 117 tumours highly reduced. In 150 tumours (37.4%), no or only a weak membranous beta-ct expression was found. Additionally, in 53 tumours, a strong beta-ct expression could be observed in the cytoplasm with a simultaneous nuclear beta-ct immunoreactivity in 17 of these 53 tumours, while nine tumours only showed nuclear immunoreactivity without cytoplasmic staining. There were no significant correlations between the degree of membranous beta-ct expression or the different staining pattern (membranous vs. cytoplasmic/nuclear) and the grade of tumour differentiation, the histological tumour type according to Lauren, as well as with the prognostic parameters pT, pN category and vascular invasion. No associations could be found with tumour cell proliferation and the expression of E-cadherin, irrespectively of the different beta-ct staining pattern. Univariate analysis revealed no influence on survival, either for membranous or for cytoplasmic/nuclear beta-ct expression.

CONCLUSION

Our data on 401 tumours suggest that activation of the Wnt/beta-catenin signalling does also occur in a subset of gastric carcinomas. However, in gastric cancer, neither the presence of cytoplasmic/nuclear beta-ct expression nor the reduction or loss of membranous beta-ct expression is correlated with a specific histological tumour type, tumour progression or prognosis.

Chromosomal imbalances in gastric cancer. Correlation with histologic subtypes and tumor progression

DNA copy number changes were analyzed by comparative genomic hybridization (CGH) in 38 gastric carcinomas and correlated with tumor histologic type and progression. Gains of copy numbers were observed in all tumors, affecting all chromosomes except chromosome 16. The average number of copy number gains was 7 (range, 1-13), most frequently located on chromosomes 11, 12, 15, 17, and 20 in 45% to 97% of tumors. High-level amplifications were found on chromosomes 12, 15, 17, and 20; the latter was affected most frequently (66%). Loss of DNA copy numbers was detected in 14 tumors affecting 7 chromosomes. No statistically significant differences in the frequency and pattern of chromosomal imbalances were observed in tumor histologic type (Lauren classification) and grade of differentiation, as well as the prognostic parameters depth of invasion (pT) and lymph node involvement (pN). Our results indicate that in gastric cancer there is no specific recurrent pattern of DNA aberrations to be correlated with tumor histologic type or stage. However, CGH analysis could reveal new, recurrent genetic changes in gastric cancer affecting chromosomes sites that harbor genes known to participate in tumorigenesis and progression of several human malignant neoplasms.

Secondary abscess formation in pituitary adenoma after tooth extraction. Case report

The presence of an abscess in a pituitary tumor is a very rare finding. The authors report the case of a 69-year-old man with a pituitary adenoma confirmed by neuroimaging results, in whom a high fever, meningismus, and left-sided ophthalmoplegia developed 4 days after tooth extraction. The results of serial cranial magnetic resonance imaging were highly indicative of an abscess formation within the pituitary adenoma. During surgery the tumor was approached transsphenoidally and removed. Histological examination confirmed the presence of an abscess formation within the pituitary adenoma. It is most likely that the tooth extraction caused a bacteremia, which led to an inflammation with abscess formation within the pituitary adenoma. The authors conclude that invasive dental procedures should be avoided before planned resection of a pituitary adenoma.

INI1 mutations in meningiomas at a potential hotspot in exon 9

Rhabdoid tumours have been shown to carry somatic mutations in the INI1 (SMARCB1/hSNF5) gene. A considerable fraction of these tumours exhibit allelic losses on chromosome 22. Allelic loss on 22q also is characteristic for meningiomas, however most of these alterations are considered to be associated with mutations of the NF2 gene. We examined a series of 126 meningiomas for alterations in the INI1 gene. Four identical somatic mutations in exon 9 were detected resulting in an exchange of Arg to His in position 377 of INI1. Our observations were reproduced both by using DNA from a new round of extraction and by employing overlapping primers. This mutational hotspot therefore appears to be an important target in the formation of a fraction of meningiomas. In addition, 4 novel polymorphisms of INI1 were characterized. Our data indicate that the INI1 is a second tumour suppressor gene on chromosome 22 that may be important for the genesis of meningiomas.

Discrimination between neoplastic and nonneoplastic brain lesions by use of proton MR spectroscopy: the limits of accuracy with a logistic regression model

BACKGROUND AND PURPOSE

The most accurate method of clinical MR spectroscopy (MRS) interpretation remains an open question. We sought to construct a logistic regression (LR) pattern recognition model for the discrimination of neoplastic from nonneoplastic brain lesions with MR imaging-guided single-voxel proton MRS data. We compared the LR sensitivity, specificity, and receiver operator characteristic (ROC) curve area (Az) with the sensitivity and specificity of blinded and unblinded qualitative MRS interpretations and a choline (Cho)/N-acetylaspartate (NAA) amplitude ratio criterion.

METHODS

Consecutive patients with suspected brain neoplasms or recurrent neoplasia referred for MRS were enrolled once final diagnoses were established by histopathologic examination or serial neurologic examinations, laboratory data, and imaging studies. Control spectra from healthy adult volunteers were included. An LR model was constructed with 10 input variables, including seven metabolite resonance amplitudes, unsuppressed brain water content, water line width, and the final diagnosis (neoplasm versus nonneoplasm). The LR model output was the probability of tumor, for which a cutoff value was chosen to obtain comparable sensitivity and specificity. The LR sensitivity and specificity were compared with those of qualitative blinded interpretations from two readers (designated A and B), qualitative unblinded interpretations (in aggregate) from a group of five staff neuroradiologists and a spectroscopist, and a quantitative Cho/NAA amplitude ratio > 1 threshold for tumor. Sensitivities and specificities for each method were compared with McNemar's chi square analysis for binary tests and matched data with a significance level of 5%. ROC analyses were performed where possible, and Az values were compared with Metz's method (CORROC2) with a 5% significance level.

RESULTS

Of the 99 cases enrolled, 86 had neoplasms and 13 had nonneoplastic diagnoses. The discrimination of neoplastic from control spectra was trivial with the LR, reflecting high homogeneity among the control spectra. An LR cutoff probability for tumor of 0.8 yielded a specificity of 87%, a comparable sensitivity of 85%, and an area under the ROC curve of 0.96. Sensitivities, specificities, and ROC areas (where available) for the other methods were, on average, 82%, 74%, and 0.82, respectively, for readers A and B, 89% (sensitivity) and 92% (specificity) for the group of unblinded readers, and 79% (sensitivity), 77% (specificity), and 0.84 (Az) for the Cho/NAA > 1 criterion. McNemar's analysis yielded significant differences in sensitivity (n approximately 86 neoplasms) between the LR and reader A, and between the LR and the Cho/NAA > 1 criterion. The differences in specificity between the LR and all other methods were not significant (n approximately 13 nonneoplasms). Metz's analysis revealed a significant difference in Az between the LR and the Cho/NAA ratio criterion.

Implications of parental compliance on decision making in care provided using general anesthesia in a low-income population

The purpose of this study was to determine the compliance of parents for bringing the child back to the dentist for follow up dental care to aid in the decision making for care provided to the children of low income families requiring general anesthesia. The dental records of 244 children of low-income families were examined. Forty-three percent of the patients did not return for follow-up dental care. Consideration should be given to modifying treatment plans to include full coverage restorations and possibly delaying treatment before the eruption of the primary second molars.

Beta7 integrins contribute to demyelinating disease of the central nervous system

A role for alpha4 integrins in different forms of the multiple sclerosis-like disease experimental autoimmune encephalomyelitis (EAE) has been demonstrated, but the individual contributions of alpha4beta1, alpha4beta7, and the related alphaEbeta7 integrin have not been determined. The P7 integrins alpha4beta7 and alphaEbeta7 play a central role in chronic inflammation, mediating the trafficking, entry, and/or adhesion of lymphocytes in the inflamed pancreas and gut, and their ligands MAdCAM-1, VCAM-1 and E-cadherin are expressed on brain endothelial cells and/or on microvessels in the inflamed central nervous system. Here, we show that an antibody directed against the beta7 subunit greatly attenuates a non-remitting form of EAE, induced by adoptive transfer of myelin oligodendrocyte peptide (MOG35-55)-stimulated T cells. Combinational treatment with both anti-beta7 and alpha4 integrin subunit antibodies led to more rapid and complete remission than that obtained with anti-alpha4 antibody alone, potentially implicating a role for alphaEbeta7 in disease progression. Remission correlated with the down-regulation of the vascular addressins VCAM-1. MAdCAM-1, and ICAM-1 on cerebral blood vessels. Attenuated forms of disease were induced by adoptive transfer of either wild-type encephalitogenic T cells to beta7-deficient gene knockout mice, or of beta7-/-encephalitogenic T cells to wild-type recipients. The former finding indicates that beta7 + ve recruited cells contribute to disease progression. Thus alpha4beta1, alpha4beta7, and alphaEbeta7 integrins may all play a contributory role in the progression of chronic forms of demyelinating disease, and together with their ligands could represent potential targets for improved treatment of some forms of multiple sclerosis.

ENVIRONMENTAL AUDITING: Environmental Auditing in Hospitals: First Results in a University Hospital

/ While medical audit in infection control today is one important element in the quality assurance of health care, environmental auditing, approved in 1993 by the Council of the European Communities for the industrial sector, so far has not been used as a tool to control and reduce environmental pollution caused by medical care. The aim of this study was to investigate whether environmental auditing according to the European Eco-Management and Audit Scheme (EMAS) can be implemented in hospitals as a process of improvement in protection of the environment. In a prior publication the methodological issues and the organizational steps that had to be taken were described. An environmental review of the activities of the Freiburg University Hospital and an ecoanalysis of the input and output were performed. The results of this analysis, published in an environmental report, provide a fundamental data set for the consumption of energy, water, materials, and the burdens of major pollutants and waste. Regarding the organizational structure of the hospital, the first steps towards an integrating environmental management system as demanded by EMAS could be taken. Beside supporting advantages, e.g., improvement of environmental safety, public image and staff contentment, and potential economic benefits such as less cost to be paid for energy and water consumption, there are important restrictions of environmental auditing in hospitals. Examples are the lack of basic environmental data, staff motivation (especially of physicians), cooperation of the organizational substructures, and funds for prefinancing urgently needed improvements in ecology. Based on the study findings, a textbook on environmental auditing in hospitals, including checklists covering all important environmental objectives, has been published to support hospitals in their efforts to achieve an optimized and sustainable practice of providing health care.

Method for analysis of exhaled air by microwave energy desorption coupled with gas chromatography-flame ionization detection-mass spectrometry

A method for chemical analysis of volatile constituents in exhaled air of mechanically ventilated patients is described. Exhaled substances are adsorbed and concentrated onto activated charcoal, desorbed by microwave energy and transferred into a gas chromatograph for separation without prior cryofocusing. Substances are identified by flame ionisation detection and mass spectrometry. This method yields reproducible results and is well suited for clinical studies.