Incidence of chromosomal imbalances in advanced colorectal carcinomas and their metastases

Comparative genomic hybridization (CGH) was used to screen 54 advanced colon carcinomas. i.e., 24 primary tumors and 30 metastases, for chromosomal alterations. Using a sensitive statistical method for the determination of DNA imbalances and histograms for analysis of the incidence of changes, we identified the DNA over-representation of chromosome 20q as the most common alteration being present in 100% of cases. High incidence deletions were observed on 18q21-18q23 (96%), 4q27-4q28 (96%), 4p14 (87%), 5q21 (81%), 1p21-1p22 (72%), 21q21 (74%), 6q16 (72%), 3p12 (66%), 8p24-8p21 (66%), 9p21 (64%), 11q22 (64%), and 14q13-14q21 (64%). Further frequent over-representation was found on 7q12-7q11.2 (75%), 16p11-16p12 (70%), 19p13 (70%), 9q34 (67%), 19q13 (67%), 13q34 (64%), 13q13 (64%), 17q21 (59%), 22q11 (61%), 8q24 (57%), and 1q21 (57%). Pronounced DNA gains and losses being defined as regions in which the ratio profiles exceeded the values of 1.5 and 0.5, respectively, frequently colocalized with peaks of incidence curve. The use of difference histograms for the comparison of tumor subgroups as well as case-by-case histogram for the analysis of 15 paired tumor samples identified several of the above alterations as relevant for tumor progression and metastasis formation. The study identified additional loci and delineates more precisely those that have been previously reported. For comparative purposes, we have made our primary data (ratio profiles, clinicopathological parameters, histograms) available at the interactive web site http://amba.charite.de/cgh, where the incidence of changes can be determined at individual loci and additional parameters can be applied for the analysis of our CGH results.     

The water jet as a new tool for endoprosthesis revision surgery--an in vitro study on human bone and bone cement

In revision surgeries of endoprostheses, the interface between implant and bone cement or bone must be loosened. Conventional tools have many disadvantages because of their size and limited range. Taking advantage of the selective and athermic cutting process, a plain water jet is already used in order to cut soft tissues. This study investigates the possibilities of both a plain and an abrasive water jet as cutting tools for revision surgery. Samples of the mid-diaphysis of human femora and bone cement (CMW3) were cut with a plain water jet (PWJ) and an abrasive water jet (AWJ) at two different jet-to-surface angles (30 degrees,90 degrees ) and at five different pressure levels (30, 40, 50, 60, 70 MPa). For a PWJ a selective pressure range was identified, where only bone cement was cut. Injecting a bio-compatible abrasive (lactose) to the jet stream resulted in significantly higher cut depths in both materials. Material removal in bone was significantly less at the smaller jet-to-surface angle for both techniques. No clear selectivity between bone and bone cement was observed for application of the AWJ. However, the material removal rate was significantly higher for bone cement than for bone at all pressure levels. The results indicate that an AWJ might be an alternative tool for cement removal. The possibility for localised cutting at interfaces could be an advantage for revision of a non-cemented prosthesis.     

Dermatoglyphics in Congenital Adrenal Hyperplasia (CAH)

Dermatoglyphic findings were compared in 42 patients (32 females, 10 males) with Congenital Adrenal Hyperplasia (CAH) and 110 normal controls (70 females, 40 males). In CAH males, an excess of whorls (p less than 0.001), an increased total finger ridge count (p less than 0.05), and an increased frequency of patterns in the fourth interdigital area (p less than 0.025) was found. A main line A terminating high in the hypothenar area (p less than 0.05), and a missing c-triradius or an abortive main line C (p less than 0.05) was observed in CAH females. Both sexes displayed an increase in the frequency of small radially directed hypothenar patterns (p less than 0.05) and sydney lines (p less than 0.01).     

New recombinants within the MHC (B-complex) of the chicken

In a search for genetic recombinations within the major histocompatibility complex (MHC) of the chicken, the B-complex, the offspring from matings between heterozygous B15/B21 and B4/B6 animals were analysed by red cell agglutination. Among the progeny, 8,912 informative typings were performed. Four recombinants were found, all separating the B-complex loci B-F and B-G (B-F codes for Class I antigens, B-G codes for an antigen of which there is no known homologue in mammals). B-L (Class II antigen) always followed B-F. Stimulation in graft versus host reactions and in mixed lymphocyte cultures followed B-F/B-L. The mapping distance between the two loci B-F and B-G is in the range of 0.04 centimorgan. The lack of recombinants separating individual B-F loci in this study and in the studies of others might indicate that chicken MHC is less complex than those of mammalian species, but alternative explanations are also possible. So far no serologically defined recombinant separating Class I (B-F) and Class II (B-L) loci has been found.     

Reversible blockade of experience-dependent plasticity by calcineurin in mouse visual cortex

Numerous protein kinases have been implicated in visual cortex plasticity, but the role of serine/threonine protein phosphatases has not yet been established. Calcineurin, the only known Ca2+/calmodulin-activated protein phosphatase in the brain, has been identified as a molecular constraint on synaptic plasticity in the hippocampus and on memory. Using transgenic mice overexpressing calcineurin inducibly in forebrain neurons, we now provide evidence that calcineurin is also involved in ocular dominance plasticity. A transient increase in calcineurin activity is found to prevent the shift of responsiveness in the visual cortex following monocular deprivation, and this effect is reversible. These results imply that the balance between protein kinases and phosphatases is critical for visual cortex plasticity.     

Comparison of viable cell yield from excised versus aspirated adipose tissue

The correction of soft-tissue defects by adipose tissue transplantation often produces poor and unpredictable results. The implantation of isolated and cultured preadipocytes offers a solution to this problem since these cells differentiate into adipocytes when implanted in vivo. A field of major interest is to maximize the yield of preadipocytes isolated from adipose tissue showing only low contamination with other cell types. Aspiration and excision are two concurrent clinical ways of harvesting adipose tissue for the isolation of preadipocytes. This tissue is usually discarded after surgery. In this study, the yield of preadipocytes obtained from liposuction material was compared to that of excised adipose tissue. Furthermore, we determined the loss of precursor cells if isolation of preadipocytes was delayed for 24 h. Preadipocytes were isolated from the stromal cell fraction of human subcutaneous adipose tissue samples. Harvesting of adipose tissue by suction was performed according to the Coleman procedure (manually applied negative pressure using a 10-ml syringe with a blunt tip cannula). Isolation was either carried out within 60 min after extraction or after storage for 24 h in culture medium at 4 degrees C. Isolated preadipocytes were cultured for 24 h, trypsinized and counted in a Neubauer chamber. Our results show clearly that the yield of preadipocytes isolated from liposuction material (within 60 min after extraction and after 24 h of storage) is higher than the cell yield from excised adipose tissue. Overnight storage for 24 h leads to a significant loss of preadipocytes in excised tissue but not in liposuction material. The high yield of cells isolated from liposuction material proves that extraction by suction does not damage the stromal cell fraction in the adipose tissue. If cell isolation is not performed immediately after the operation, liposuction material is clearly the better alternative for storage.     

Cancer gene therapy with tissue inhibitors of metalloproteinases (TIMPs)

Matrix metalloproteinases (MMPs) are of crucial importance for the invasive behavior of primary tumors and their metastases. MMP activity is regulated by the four naturally occurring tissue inhibitors of metalloproteinases (TIMPs). It has been shown that overexpression of TIMPs in tumors of various origins leads to reduced tumor growth and formation of metastases. More recently, antitumor efficacy by in vivo gene transfer of TIMPs has been reported in several clinically relevant animal models. This review analyses the therapeutic potential of the TIMPs from a cancer gene therapeutic point of view with particular emphasis on cell culture and in vivo data.     

Der Tagesgang der Phasenkoppelung zwischen Herzschlag und Atmung in Ruhe und seine Beeinflussung durch dosierte Arbeitsbelastung

Zusammenfassung An insgesamt 33 gesunden Versuchspersonen im Alter von 18–32 Jahren wurde der Tagesgang der Phasenkoppelung zwischen Herzschlag (R-Zacke im EKG) und Atmung (Inspirationsbeginn) mit dem Koincidenzmeßgerät Synchromet unter verschiedenen Bedingungen untersucht. Bei 10 Probanden erfolgten die Messungen bei Bettruhe in einstündigen Abständen, weitere 10 Personen wurden alle 2 Std im Anschluß an die Koppelungsmessung mit dosierter Tretkurbelarbeit belastet, die übrigen 13 Probanden nur in vierstündigen Abständen, wobei die Phasenkoppelung zweistündlich kontrolliert wurde.In der Ruhegruppe fand sich im Mittel ein signifikanter tagesrhythmischer Gang des Koppelungsgrades mit einem nächtlichen Maximum gegen 1.00 Uhr und einem Minimum zwischen 12.00 und 17.00 Uhr. Die individuellen Tagesamplituden des Koppelungsgrades betragen zwischen 2,8 und 11,6 E (Mittelwert 6,4); sie waren um so größer, je höher das individuelle Tagesniveau von Pulsfrequenz und Puls-Atem-Quotient lag. Die individuellen Tagesmaxima lagen in Ruhe zu 85% in der Nachthälfte (19.00-7.00 Uhr), die Minima zu 75% am Tage (7.00-19.00 Uhr).Bei vierstündlich wiederholter Arbeitsbelastung war die Amplitude im mittleren Tagesgang des Koppelungsgrades, der zwei Gipfel mit 12stündigem Abstand aufwies, signifikant kleiner, bei zweistündlicher Belastungsfolge fehlte sie vollständig. Die individuellen Amplitudenwerte betrugen zwischen 1,3 und 7,5 (Mittelwert 3,1) bzw. 1,1 und 5,5 E (Mittelwert 2,8). Die individuellen Tagesmaxima lagen bei vierstündlicher Belastung noch zu 65% in der Nachthälfte, bei zweistündlicher Belastung nur noch zu 60%, die entsprechende Minimahäufigkeit in der Tageshälfte betrug 58 bzw. 50%. Die Häufigkeitsverteilung der Maxima und Minima war vorzugsweise zweigipfelig mit etwa 12stündigen Gipfelabständen.Im Gegensatz zu der Abschwächung bzw. Unterdrückung der nächtlichen Zunahme des Koppelungsgrades näherte sich das mittlere Frequenzverhältnis aus Puls und Atmung auch in den Belastungsgruppen während der Nacht der Norm 41 an. Der mittlere Tagesgang der Herzfrequenz war bei ähnlichem Niveau aller drei Gruppen nur bei vierstündlicher Belastungsfolge deutlich zweigipfelig mit 12stündigem Gipfelabstand.Die tagesrhythmische Schwankung des Koppelungsgrades wird auf vegetative Umstellungen zurückgeführt, die nicht unmittelbar an den Schlaf gebunden sind. Aus den Befunden bei Arbeitsbelastung wird geschlossen, daß die Phasenkoordination zwischen Herzschlag und Atmung schon durch leichte Arbeitsbelastung nach-haltig gestört wird und längere Erholungszeiten benötigt als Frequenz und Frequenzkoordination beider Rhythmen. Die Phasenkoppelung wird daher als empfindlichster Indicator für die Erholungsvorgänge im Bereich der rhythmischen Koordination angesehen.     

Inter-laboratory validation of PCR-based detection of Mycobacterium tuberculosis in formalin-fixed, paraffin-embedded tissues

The present study is based on the initiative for quality assurance in pathology of the German Society of Pathology and the Professional Association of German Pathologists. Four panel laboratories with experience and expertise in polymerase chain reaction (PCR) detection of Mycobacterium tuberculosis were selected to establish the prerequisites for continuous external laboratory trials, in particular, by providing pre-tested specimens and evaluation criteria for participating institutes. In the first step, the four panel laboratories performed an internal trial to test their own reliability and reproducibility. Paraffin sections and DNA preparations from 34 tissues (25 clinical specimens and 9 controls) totalling to 66 samples were evaluated by each panel institute according to their own protocols. The methodologies differed and are described in detail. Despite these differences, a high degree of inter-laboratory reliability was achieved. In this report, we summarise our results including the correlation with the histology and provide recommendations for applying PCR-based methodology for the detection of mycobacterial DNA in surgical specimens. Supplementary data are available online at (rubric Forschung). Pre-tested specimens are now available for the external trial and can be ordered from the steering institute via Oligene (). All molecular pathology laboratories are invited to participate in this quality assurance initiative.