Screening for the Lynch syndrome (hereditary nonpolyposis colorectal cancer)

BACKGROUND

Germ-line mutations in the mismatch-repair genes MLH1, MSH2, MSH6, and PMS2 lead to the development of the Lynch syndrome (hereditary nonpolyposis colorectal cancer), conferring a strong susceptibility to cancer. We assessed the frequency of such mutations in patients with colorectal cancer and examined strategies for molecular screening to identify patients with the syndrome.

METHODS

Patients with a new diagnosis of colorectal adenocarcinoma at the major hospitals in metropolitan Columbus, Ohio, were eligible for the study. Genotyping of the tumor for microsatellite instability was the primary screening method. Among patients whose screening results were positive for microsatellite instability, we searched for germ-line mutations in the MLH1, MSH2, MSH6, and PMS2 genes with the use of immunohistochemical staining for mismatch-repair proteins, genomic sequencing, and deletion studies. Family members of carriers of the mutations were counseled, and those found to be at risk were offered mutation testing.

RESULTS

Of 1066 patients enrolled in the study, 208 (19.5 percent) had microsatellite instability, and 23 of these patients had a mutation causing the Lynch syndrome (2.2 percent). Among the 23 probands with the Lynch syndrome, 10 were more than 50 years of age and 5 did not meet the Amsterdam criteria or the Bethesda guidelines for the diagnosis of hereditary nonpolyposis colorectal cancer (including the use of age and family history to identify patients at high risk for the Lynch syndrome). Genotyping for microsatellite instability alone and immunohistochemical analysis alone each failed to identify two probands. In the families of 21 of the probands, 117 persons at risk were tested, and of these, 52 had Lynch syndrome mutations and 65 did not.

CONCLUSIONS

Routine molecular screening of patients with colorectal adenocarcinoma for the Lynch syndrome identified mutations in patients and their family members that otherwise would not have been detected. These data suggest that the effectiveness of screening with immunohistochemical analysis of the mismatch-repair proteins would be similar to that of the more complex strategy of genotyping for microsatellite instability.

Feasibility of screening for Lynch syndrome among patients with colorectal cancer

PURPOSE

Identifying individuals with Lynch syndrome (LS) is highly beneficial. However, it is unclear whether microsatellite instability (MSI) or immunohistochemistry (IHC) should be used as the screening test and whether screening should target all patients with colorectal cancer (CRC) or those in high-risk subgroups.

PATIENTS AND METHODS

MSI testing and IHC for the four mismatch repair proteins was performed on 500 tumors from unselected patients with CRC. If either MSI or IHC was abnormal, complete mutation analysis for the mismatch repair genes was performed.

RESULTS

Among the 500 patients, 18 patients (3.6%) had LS. All 18 patients detected with LS (100%) had MSI-high tumors; 17 (94%) of 18 patients with LS were correctly predicted by IHC. Of the 18 probands, only eight patients (44%) were diagnosed at age younger than 50 years, and only 13 patients (72%) met the revised Bethesda guidelines. When these results were added to data on 1,066 previously studied patients, the entire study cohort (N = 1,566) showed an overall prevalence of 44 of 1,566 patients (2.8%; 95% CI, 2.1% to 3.8%) for LS. For each proband, on average, three additional family members carried MMR mutations.

CONCLUSION

One of every 35 patients with CRC has LS, and each has at least three relatives with LS; all of whom can benefit from increased cancer surveillance. For screening, IHC is almost equally sensitive as MSI, but IHC is more readily available and helps to direct gene testing. Limiting tumor analysis to patients who fulfill Bethesda criteria would fail to identify 28% (or one in four) cases of LS.

Huntingtin is a cytoplasmic protein associated with vesicles in human and rat brain neurons

The gene defective in Huntington's disease encodes a protein, huntingtin, with unknown function. Antisera generated against three separate regions of huntingtin identified a single high molecular weight protein of approximately 320 kDa on immunoblots of human neuroblastoma extracts. The same protein species was detected in human and rat cortex synaptosomes and in sucrose density gradients of vesicle-enriched fractions, where huntingtin immunoreactivity overlapped with the distribution of vesicle membrane proteins (SV2, transferrin receptor, and synaptophysin). Immunohistochemistry in human and rat brain revealed widespread cytoplasmic labeling of huntingtin within neurons, particularly cell bodies and dendrites, rather than the more selective pattern of axon terminal labeling characteristic of many vesicle-associated proteins. At the ultrastructural level, immunoreactivity in cortical neurons was detected in the matrix of the cytoplasm and around the membranes of the vesicles. The ubiquitous cytoplasmic distribution of huntingtin in neurons and its association with vesicles suggest that huntingtin may have a role in vesicle trafficking.

Effect of school-based interventions on physical activity and fitness in children and adolescents: a review of reviews and systematic update

BACKGROUND

School-based interventions are thought to be the most universally applicable and effective way to counteract low physical activity (PA) and fitness although there is controversy about the optimal strategy to intervene.

OBJECTIVES

The objective of this review was to summarise recent reviews that aimed to increase PA or fitness in youth and carry out a systematic review of new intervention studies.

METHODS

Relevant systematic reviews and original controlled and randomised controlled school-based trials with a PA or fitness outcome measure, a duration of ≥12 weeks, a sufficient quality and involvement of a healthy population aged 6-18 years that were published from 2007 to 2010 were included. Results In these reviews, 47-65% of trials were found to be effective. The effect was mostly seen in school-related PA while effects outside school were often not observed or assessed.

CONCLUSIONS

The school-based application of multicomponent intervention strategies was the most consistent, promising strategy, while controversy existed regarding the effectiveness of family involvement, focus on healthy populations at increased risk or duration and intensity of the intervention. All 20 trials in the review update showed a positive effect on in-school, out-of-school or overall PA, and 6 of 11 studies showed an increase in fitness. Taking into consideration both assessment quality and public health relevance, multicomponent approaches in children including family components showed the highest level of evidence for increasing overall PA. This review confirms the public health potential of high quality, school-based PA interventions for increasing PA and possibly fitness in healthy youth.

Novel effects of nitric oxide

Nitric oxide (NO), a simple free radical gas, elicits a surprisingly wide range of physiological and pathophysiological effects. NO interacts with soluble guanylate cyclase to evoke many of these effects. However, NO can also interact with molecular oxygen and superoxide radicals to produce reactive nitrogen species that can modify a number of macromolecules including proteins, lipids, and nucleic acids. NO can also interact directly with transition metals. Here, we have reviewed the non--3',5'-cyclic-guanosine-monophosphate-mediated effects of NO including modifications of proteins, lipids, and nucleic acids.

Role of interferon regulatory factor 1 in induction of nitric oxide synthase

Interferon gamma (IFN-gamma) interacts synergistically with bacterial lipopolysaccharide (LPS) to induce transcription of iNOS, the isoform of nitric oxide synthase whose activity is independent of elevated Ca2+ and exogenous calmodulin. To define a cis-acting element mediating IFN-gamma-dependent synergy, we made deletions in iNOS promoter constructs fused to reporter genes, transfected RAW 264.7 macrophages, and treated the cells with IFN-gamma and/or LPS. This analysis implicated the region from positions -951 to -911, a cluster of four enhancer elements known to bind IFN-gamma-responsive transcription factors, including an interferon regulatory factor binding site (IRF-E) at nucleotides -913 to -923. Site-specific substitution of two conserved nucleotides within IRF-E in the context of the full-length iNOS promoter ablated IFN-gamma's contribution to synergistic enhancement of transcription. Electromobility shift assays performed with a probe containing IRF-E revealed the existence of a complex in nuclei of RAW 264.7 macrophages that was present only after treatment with IFN-gamma, which reacted specifically with anti-IRF-1 immunoglobulin G and which included a species migrating at 40-45 kD, consistent with the apparent molecular weight of murine IRF-1. Thus, the synergistic contribution of IFN-gamma to transcription of iNOS in RAW 264.7 macrophages requires that IRF-1 bind to IRF-E in the iNOS promoter. In conjunction with the work of Kamijo et al. (Kamijo, R., H. Harada, T. Matsuyama, M. Bosland, J. Gerecitano, D. Shapiro, J. Le, K. S. Im, T. Kimura, S. Green et al. 1994. Science [Wash. DC]. 263:1612), these findings identify iNOS as the first gene that requires IRF-1 for IFN-gamma-dependent transcriptional regulation.

Role of NFkappaB in the mortality of sepsis

Binding activity for nuclear factor kappa B (NFkappaB) consensus probes was studied in nuclear extracts from peripheral blood mononuclear cells of 15 septic patients (10 surviving and 5 not surviving). Nonsurvivors could be distinguished from survivors by an increase in NFkappaB binding activity during the observation period (P < 0.001). The increase in NFkappaB binding activity was comparable to the APACHE-II score as a predictor of outcome. Intravenous somatic gene transfer with an expression plasmid coding for IkappaBalpha was used to investigate the role of members of the NFkappaB family in a mouse model of endotoxemia. In this model, increased NFkappaB binding activity was present after injection of LPS. Intravenous somatic gene transfer with IkappaBalpha given before LPS attenuated renal NFkappaB binding activity and increased survival. Endothelial cells and monocytes/macrophages were the major target cells for somatic gene transfer, transfected with an average transfection efficiency of 20-35%. Tissue factor, a gene under regulatory control of NFkappaB, was induced by LPS. Somatic gene transfer with a reporter plasmid containing the functional tissue factor promoter demonstrated NFkappaB-dependent stimulation by LPS. Intravenous somatic gene transfer with IkappaBalpha reduced LPS-induced renal tissue factor expression, activation of the plasmatic coagulation system (decrease of thrombin-antithrombin III complexes) and renal fibrin/fibrinogen deposition. Somatic gene transfer with an expression plasmid with tissue factor cDNA in the antisense direction (in contrast to sense or vector alone) also increased survival. Furthermore, antisense tissue factor decreased renal tissue factor expression and the activation of the plasmatic coagulation system.

Comparisons of soxhlet extraction, pressurized liquid extraction, supercritical fluid extraction and subcritical water extraction for environmental solids: recovery, selectivity and effects on sample matrix

Extractions of a polycyclic aromatic hydrocarbon (PAH)-contaminated soil from a former manufactured gas plant site were performed with a Soxhlet apparatus (18 h), by pressurized liquid extraction (PLE) (50 min at 100 degrees C), supercritical fluid extraction (SFE) (1 h at 150 degrees C with pure CO2), and subcritical water (1 h at 250 degrees C, or 30 min at 300 degrees C). Although minor differences in recoveries for some PAHs resulted from the different methods, quantitative agreement between all of the methods was generally good. However, the extract quality differed greatly. The organic solvent extracts (Soxhlet and PLE) were much darker, while the extracts from subcritical water (collected in toluene) were orange, and the extracts from SFE (collected in CH2Cl2) were light yellow. The organic solvent extracts also yielded more artifact peaks in the gas chromatography (GC)-mass spectrometry and GC-flame ionization detection chromatograms, especially compared to supercritical CO2. Based on elemental analysis (carbon and nitrogen) of the soil residues after each extraction, subcritical water, PLE, and Soxhlet extraction had poor selectivity for PAHs versus bulk soil organic matter (approximately 1/4 to 1/3 of the bulk soil organic matter was extracted along with the PAHs), while SFE with pure CO2 removed only 8% of the bulk organic matrix. Selectivities for different compound classes also vary with extraction method. Extraction of urban air particulate matter with organic solvents yields very high concentrations of n- and branched alkanes (approximately C18 to C30) from diesel exhaust as well as lower levels of PAHs, and no selectivity between the bulk alkanes and PAHs is obtained during organic solvent extraction. Some moderate selectivity with supercritical CO2 can be achieved by first extracting the bulk alkanes at mild conditions, followed by stronger conditions to extract the remaining PAHs, i.e., the least polar organics are the easiest organics to extract with pure CO2. In direct contrast, subcritical water prefers the more polar analytes, i.e., PAHs were efficiently extracted from urban air particulates at 250 degrees C, with little or no extraction of the alkanes. Finally, recent work has demonstrated that many pollutant molecules become "sequestered" as they age for decades in the environment (i.e., more tightly bound to soil particles and less available to organisms or transport). Therefore, it may be more important for an extraction method to only recover pollutant molecules that are environmentally-relevant, rather than the conventional attempts to extract all pollutant molecules regardless of how tightly bound they are to the soil or sediment matrix. Initial work comparing SFE extraction behavior using mild to strong conditions with bioremediation behavior of PAHs shows great promise to develop extraction methodology to measure environmentally-relevant concentrations of pollutants in addition to their total concentrations.

Angiosarcomas, a heterogeneous group of sarcomas with specific behavior depending on primary site: a retrospective study of 161 cases

BACKGROUND

Angiosarcomas are rare, heterogeneous and a retrospective study was conducted to describe their natural history.

PATIENTS AND METHODS

We reviewed 161 files of angiosarcoma treated in three institutions of the French Sarcoma Group from 1980 to 2004. Survival and prognostic factors for survival were analyzed.

RESULTS

Median age was 52 years. Primary sites were the breast (35%), skin (20%) and soft tissues (13%). At initial diagnosis, 31 (19%) had metastases. Surgery was the first treatment in 121 (75%) patients combined with chemotherapy or radiotherapy in 34 and 32, respectively. Ninety (74%) of these 121 patients relapsed, mostly locally (50). With an average time since initial diagnosis of 8.1 years, 123 (76%) patients progressed and 76 (47%) died. Median survival was 3.4 years [95% confidence interval (CI) 2.4-5.8], and the 5-year overall survival (OS) rate was 43% (95% CI 33-53). In multivariate analysis, liver primary site [relative risk (RR) = 12.62], performance status (PS) of two or more (RR = 3.83), presence of metastases at diagnosis (RR = 2.50), soft tissue tumor (RR = 0.31) were correlated to OS. PS, liver and soft tissue tumors were identified as independent prognostic factors for progression-free survival.

CONCLUSIONS

Angiosarcomas have an overall poor outcome, but with a clearly distinct prognosis depending on the primary site.

Efficacy and safety of thrombolytic therapy after initially unsuccessful cardiopulmonary resuscitation: a prospective clinical trial

BACKGROUND

During cardiopulmonary resuscitation (CPR), thrombolysis can help to stabilise patients with pulmonary embolism and myocardial infarction. Moreover, thrombolysis during CPR has beneficial effects on cerebral reperfusion after cardiac arrest. We investigated this new therapeutic approach in patients in whom conventional CPR had been unsuccessful.

METHODS

We assessed, in a prospective study, patients undergoing CPR after out-of-hospital cardiac arrest for cardiological reasons in whom return of spontaneous circulation was not achieved within 15 min. According to the Ustein criteria, our control group consisted of patients who were assessed during 1 year. After this year patients were treated with a bolus of 5000 U of heparin and 50mg, over 2 min, of tissue-type plasminogen activator (rt-PA treated group). This intervention was repeated if return of spontaneous circulation was not achieved within the following 30 min. For controls only CPR was given.

FINDINGS

Overall, 90 patients were included; heparin and rt-PA were given to 40 patients. There were no bleeding complications related to the CPR procedures. Of the rt-PA group, 68% (27) had return of spontaneous circulation and 58% (23) were admitted to a cardiac intensive care unit, compared with 44% (22; p=0.026) and 30% (15; p=0.009) of the controls, respectively. At 24 h after cardiac arrest a larger proportion of the rt-PA group than of the controls was alive (35% [14] vs 22% [11], p=0.171), and 15% (six) of rt-PA-treated patients and 8% (four) of controls could be discharged from hospital.

INTERPRETATION

After initially unsuccessful out-of-hospital CPR, thrombolytic therapy combined with heparin is safe and might improve patient outcome. On the basis of our data a randomised controlled trial might be regarded as ethical.

Brain blood flow changes in depressed patients treated with interpersonal psychotherapy or venlafaxine hydrochloride: preliminary findings

BACKGROUND

Functional brain imaging studies in major depression have suggested abnormalities of areas, including the frontal cortex, cingulate gyrus, basal ganglia, and temporal cortex. We hypothesized that venlafaxine hydrochloride and interpersonal psychotherapy (IPT) might each alter brain blood flow in some or all of these areas on sequential single photon emission computed tomography (SPECT) scans.

METHODS

Twenty-eight men and women aged 30 to 53 years with a DSM-IV major depressive episode, a 17-item Hamilton Rating Scale for Depression (HAM-D) rating of 18 or higher, and antidepressant-naive for at least 6 months were studied. After baseline (99m)technetium-hexa-methyl-propylene-amine-oxime scan, 1-T magnetic resonance imaging, and psychometric ratings, patients were assigned to different treatments. Thirteen patients had 1-hour weekly sessions of IPT from the same supervised therapist (E.M.). Fifteen patients took 37.5 mg twice-daily of venlafaxine hydrochloride. Single-photon emission computed tomography scans and ratings were repeated at 6 weeks.

RESULTS

Both treatment groups improved substantially, more so with venlafaxine (mean [SD] HAM-D scores at pretreatment: IPT, 22.7 [2.7], and venlafaxine, 22.4 [3.1]; and posttreatment: IPT, 16.2 [7.1], and venlafaxine, 10.9 [8.6]). No patients had structural brain abnormalities. On analysis with statistical parametric mapping 96, the venlafaxine group showed right posterior temporal and right basal ganglia activation (P =.01), while the IPT group had limbic right posterior cingulate and right basal ganglia activation (P =.01).

CONCLUSIONS

This preliminary investigation has shown limbic blood flow increase with IPT yet not venlafaxine, while both treatments demonstrated increased basal ganglia blood flow. This was, however, a short trial with a small sample, no control group, and different symptom reduction in the 2 groups.

Randomised clinical trial comparing the effects of acupuncture and a newly designed placebo needle in rotator cuff tendinitis

Acupuncture has gained increasing attention in the treatment of chronic pain. The lack of a satisfying placebo method has made it impossible to show whether needling is an important part of the method or whether the improvement felt by the patient is due to the therapeutic setting and psychological phenomena. Also, the effectiveness of acupuncture has not been demonstrated sufficiently. We treated 52 sportsmen with rotator cuff tendinitis in a randomised single-blind clinical trial using a new placebo-needle as control. Patients were treated for 4 weeks. The primary endpoint of the trial was the change in the modified Constant-Murley-score from the baseline. Assessment of the treatment outcome was made by experienced orthopaedists not informed of the treatment allocation. Acupuncture with penetration of the skin was shown to be more effective than a similar therapeutic setting with placebo needling in the treatment of pain. The acupuncture-group improved 19.2 Constant-Murley-score points (SD 16.1, range from -13 to 50), the control-group improved 8.37 points (SD 14.56, range from -20 to 41), (P=0.014; C.I. 2.3;19.4). This study showed that needling is an important part of the acupuncture effect in the treatment of chronic shoulder pain in athletes. No conclusions can be derived from this study concerning the importance of choosing points and the rules of Traditional Chinese Medicine. Using the new placebo method as control for other ailments could improve the evidence of specific acupuncture effects beyond pain treatment.

An activity in rat tissues that modifies nitrotyrosine-containing proteins

Homogenates from rat spleen and lung could modify nitrotyrosine-containing BSA. With incubation, nitrotyrosine-containing BSA lost its epitope to a monoclonal antibody that selectively recognized nitrotyrosine-containing proteins. In the presence of protease inhibitors, the loss of the nitrotyrosine epitope occurred without protein degradation and hydrolysis. This activity was found in supernatant but not particulate fractions of spleen homogenates. The factor was heat labile, was sensitive to trypsin treatment, and was retained after passage through a membrane with a 10-kDa retention. The activity was time- and protein-concentration dependent. The activity increased about 2-fold in spleen extracts with endotoxin (bacterial lipopolysaccharide) treatment of animals, suggesting that the activity is inducible or regulatable. Other nitrotyrosine-containing proteins also served as substrates, while free nitrotyrosine and some endogenous nitrotyrosine-containing proteins in tissue extracts were poor substrates. Although the product and possible cofactors for this reaction have not yet been identified, this activity may be a "nitrotyrosine denitrase" that reverses protein nitration and, thus, decreases peroxynitrite toxicity. This activity was not observed in homogenates from rat liver or kidney, suggesting that there may also be some tissue specificity for the apparent denitrase activity.

Defensins and other endogenous peptide antibiotics of vertebrates

Gene-encoded peptide antibiotics are ubiquitous components of host defenses in mammals, birds, amphibia, insects, and plants. Their de novo synthesis or release from storage sites can be induced rapidly, which makes them particularly important in the initial phases of resistance to microbial invasion. The endogenous antimicrobial peptides of animals are products of single genes and are synthesized as preproproteins. Multistep processing yields the mature peptide, which generally acts by inducing microbial membrane permeabilization. Several families of antimicrobial peptides have been identified that differ with respect to the presence of disulfide linkages, amino acid composition, structural conformation, and spectrum of activity. The arginine-rich three disulfide-containing beta-sheet defensins are remarkably abundant and widely distributed in animals and plants. The antibiotic peptides of higher eukaryotes merit further study for their role in natural immunity and their potential as novel therapeutic compounds.

A guide to the use of pore-forming toxins for controlled permeabilization of cell membranes

Depending on the size of the pores one wishes to produce in plasma membranes, the choice will probably fall on one of the three toxins discussed above. S. aureus alpha-toxin should be tried first when pores of 1-1.5 nm diameter are required. This is generally the case when Ca2+ and nucleotide dependence of a given process is being studied. If alpha-toxin does not work, this is probably due to the fact that the toxin either does not produce pores, or that the pores are too small. In this case, high concentrations of alpha-toxin should be tried. If this still does not work, we recommend the use of HlyA. When very large pores are to be created, e.g. for introduction of antibodies into the cells, SLO or another member of this toxin family are the agents of choice. SLO preparations need to be checked for presence of protease contaminants. Tetanolysin currently offers advantages since it is protease-free, and the size of the pores can probably be controlled by varying the toxin dose. Methods for assessing the size of pores created by such agents have been published in the recent literature, and the appropriate papers can be consulted whenever the need arises.

Assessment of the safety of recombinant tissue factor pathway inhibitor in patients with severe sepsis: a multicenter, randomized, placebo-controlled, single-blind, dose escalation study

OBJECTIVE

To identify a safe and potentially effective recombinant tissue factor pathway inhibitor (rTFPI) dose for further clinical evaluation in patients with severe sepsis.

DESIGN

Prospective, randomized, single-blind, placebo-controlled, dose escalation, multicenter, multinational phase II clinical trial.

SETTING

Thirty-eight intensive care units in the United States and Europe.

PATIENTS

Two hundred and ten subjects with severe sepsis who received standard supportive care and antimicrobial therapy.

INTERVENTIONS

Subjects received a continuous intravenous infusion of placebo or rTFPI at 0.025 or 0.05 mg/kg/hr for 4 days (96 hrs).

MEASUREMENTS AND MAIN RESULTS

There were no significant imbalances in demographics, severity of illness, or source of infection in patients randomized to placebo or either dose of rTFPI. A 20% relative reduction in 28-day all-cause mortality was observed when all rTFPI-treated patients were compared with all placebo patients. An improvement in pulmonary organ dysfunction score and in a composite intensive care unit score (pulmonary, cardiovascular, and coagulation) were also noted in the rTFPI-treated patients. Logistic regression modeling indicated a substantial treatment by baseline laboratory international normalized ratio (INR) interaction effect when only treatment and INR were in the model (p =.037) and when baseline Acute Physiology and Chronic Health Evaluation (APACHE II) and log10 interleukin 6 were adjusted for (p =.026). This interaction effect indicates that higher baseline INR is associated with a more pronounced beneficial rTFPI effect. There was no increase in mortality in subjects treated with either dose of rTFPI compared with placebo. Biological activity, as detected by a statistically significant reduction in thrombin-antithrombin complexes (TATc), was noted in the all rTFPI-treated patients compared with those receiving placebo. There were no major imbalances across all treatment groups with respect to safety. The frequency of adverse events (AEs) and severe adverse events (SAEs) was similar among the treatment groups, with a slight increase in SAEs and SAEs involving bleeding in the 0.05 mg/kg/hr rTFPI group. The overall incidence of AEs involving bleeding was 28% of patients in the all placebo group and 23% of patients in the all rTFPI-treated group; a slight but statistically insignificant increase in incidence of SAEs involving bleeding was observed in the all rTFPI group (9%) as compared with the all placebo group (6%; p =.39).

CONCLUSIONS

Although the trial was not powered to show efficacy, a trend toward reduction in 28-day all-cause mortality was observed in the all rTFPI group compared with all placebo. This study demonstrates that rTFPI doses of 0.025 and 0.05 mg/kg/hr could be safely administered to severe sepsis patients. Additionally, rTFPI demonstrated bioactivity, as shown by reduction in TATc complexes and interleukin-6 levels. These findings warrant further evaluation of rTFPI in an adequately powered, placebo controlled, randomized trial for the treatment of severe sepsis.

The Cdx2 homeobox gene has a tumour suppressor function in the distal colon in addition to a homeotic role during gut development

BACKGROUND

During development, the homeobox gene Cdx2 exerts a homeotic function, providing the positional information necessary for correct specification of the midgut endoderm. This is illustrated by the non-neoplastic gastric-type heteroplasias present at birth in the pericaecal region of Cdx2(+/-) mice. Furthermore, intestinal expression of Cdx2 continues throughout life but diminishes in colorectal cancers compared with adjacent normal tissue, suggesting a role in tumorigenesis.

AIM

To investigate the consequence of altered Cdx2 expression on colon tumour initiation and/or progression.

METHODS

Heterozygous Cdx2(+/-) mice were analysed for spontaneous malignant tumours and for tumour development after treatment with a DNA mutagen, azoxymethane.

RESULTS

Cdx2(+/-) mice did not spontaneously develop malignant tumours. After azoxymethane treatment, the gastric-like heteroplasias in the pericaecal region did not evolve into cancer indicating that they are not precancerous lesions. However, azoxymethane treated Cdx2(+/-) mice developed tumours specifically in the distal colon 12 weeks after azoxymethane treatment whereas no tumours were found in wild-type littermates at this stage. Histopathological and molecular analyses indicated that these tumours were invasive adenocarcinomas that recapitulated the malignant sequence observed in the majority of sporadic colorectal cancers in human. In addition, we found that the colonic epithelium was less sensitive to radiation induced apoptosis in Cdx2(+/-) than in wild-type mice.

CONCLUSION

This study provides the first experimental evidence that Cdx2 is a tumour suppressor gene involved in cancer progression in the distal colon. This action in adults is functionally and geographically distinct from its homeotic role during gut development.

A structural basis for four distinct elution profiles on concanavalin A--Sepharose affinity chromatography of glycopeptides

Twelve 14C-acetylated glycopeptides have been subjected to affinity chromatography on concanvalin A (Con A)--Sepharose at pH 7.5. The elution profiles could be classified into four distinct patterns. The first pattern showed no retardation of glycopeptide on the column and was elicited with a glycopeptide having three peripheral oligosaccharide chains: (abstract:see text). Such glycopeptides have only a single mannose residue capable of interacting with Con A--Sepharose; an interacting mannose residue is either an alpha-linked nonreducing terminal residue or an alpha-linked 2-O-substituted residue. The second type of profile showed a retarded elution of glycopeptide with buffer lacking methyl alpha-D-glucopyranoside (indicative of weak interaction with the column) and was given by glycopeptides with the structures: (abstract: see text) where R1 is either H or a sialyl residue. The third profile type showed tight binding of glycopeptide to Con A--Sepharose and elution as a sharp peak with 0.1 M methyl alpha-D-glucopyranoside; glycopeptides giving this pattern had the structures: (abstract: see text) where R2 is either H, glcNAc, Gal-beta 1,4-GlcNAc, or sialyl-Gal-beta 1,4-GlcNAc. These glycopeptides all have two interacting mannose residues, the mimimum required for binding to the column; one of these mannose residues must, however, be a terminal residue to obtain tight binding and sharp elution. The fourth profile type showed tight binding of glycopeptide to the column but elution with 0.1 M methyl alpha-D-glucopyranoside resulted in a broad peak indicating very tight binding; glycopeptides showing this behaviour had the structures: (abstract: see text) where R3 is either GlcNAc,Gal-beta 1,4-GlcNAc, or sialyl-Gal-beta 1,4-GlcNAc. Therefore it can be concluded that although a minimum of two interacting mannose residues is required for binding to Con A--Sepharose, the residues linked to these mannoses can either strengthen or weaken binding to the column.

Ultrasound control for presumed difficult epidural puncture

BACKGROUND

The efficacy of epidural anaesthesia depends on the accurate identification of the epidural space (ES). Abnormal anatomical conditions may make the procedure difficult or impossible. The aim of this study was to investigate whether pre-puncture ultrasound examination of the spinal anatomy might be beneficial in expected cases of difficult epidural anaesthesia.

METHODS

We used digital ultrasound equipment with a 5-MHz transducer to assess the anatomy of the ES and the posterior parts of the spinal column. We examined 72 parturients with abnormal anatomical conditions who were scheduled for epidural anaesthesia. The women were randomised into two equal groups. In all patients, the standard loss of resistance technique was used. In the ultrasound group, an ultrasound examination of the appropriate spinal region was conducted prior to epidural puncture. ES depth seen on the ultrasound images was compared to the ES depth measured by the needle. We compared the number of puncture attempts with the standard method (control group) to the number of attempts under ultrasound guidance.

RESULTS

Ultrasonography significantly improved operating conditions for epidural anaesthesia. The maximum VAS scores and patient acceptance were significantly better.

CONCLUSIONS

With ultrasound measurement of the ES depth, the quality of epidural anaesthesia was enhanced.

Activation of blood coagulation after cardiac arrest is not balanced adequately by activation of endogenous fibrinolysis

BACKGROUND

Animal studies have demonstrated that hemostatic disorders occurring after cardiac arrest affect outcome. We investigated hemostatic changes during and after cardiopulmonary resuscitation (CPR) in humans.

METHODS AND RESULTS

The prospective study included 23 patients (29 to 86 years) who underwent out-of-hospital CPR for nontraumatic causes. Blood samples were drawn immediately and 15 and 30 minutes after initiation of CPR. In the case of restoration of spontaneous circulation (ROSC; n = 7), additional blood samples were taken immediately, 30 minutes, and 2, 8, 24, 48, and 72 hours after ROSC. A marked activation of blood coagulation was found in all patients. The specific markers of activated blood coagulation and fibrin formation, thrombin-antithrombin complex (TAT; median during CPR, 260 micrograms/L; median after ROSC, 57 micrograms/L; normal range, 1.0 to 4.1 micrograms/L), and fibrin monomers (FM; median during CPR, 34.3 micrograms/mL; median after ROSC, 65.4 micrograms/mL; normal range, 0 to 3.6 micrograms/mL) were markedly increased during and in the early phase after CPR. When patients survived for 48 hours, TAT and FM values returned to the normal range. In most patients, the plasma levels of D-dimer, an indicator of endogenous fibrinolytic activity, were not markedly increased during CPR (median, < 0.25 microgram/mL; normal range, < 0.25 microgram/mL) but increased moderately after ROSC (median, 0.56 microgram/mL). Levels of plasminogen activator inhibitor type 1 (normal range, 0.3 to 3.5 U/mL), a marker for endogenous inhibition of fibrinolytic activity, were moderately increased in most patients (median during CPR, 4.22 U/mL; median after ROSC, 8.08 U/mL).

CONCLUSIONS

Our data clearly demonstrate that there is a marked activation of blood coagulation and fibrin formation after prolonged cardiac arrest and CPR in humans that is not balanced adequately by concomitant activation of endogenous fibrinolysis. These changes may contribute to reperfusion disorders, such as the cerebral "no-reflow" phenomenon, by inducing fibrin deposition and formation of microthrombi.

Long term outcome after out-of-hospital cardiac arrest with physician staffed emergency medical services: the Utstein style applied to a midsized urban/suburban area

OBJECTIVE

To test the effect of a physician staffed advanced cardiac life support (ALS) system on patient outcome following out-of-hospital cardiac arrest.

DESIGN

Observational study.

SETTING

Two tier basic life support (BLS) and physician staffed ALS services in the midsized urban/suburban area of Heidelberg, Germany.

PATIENTS

All patients suffering out-of-hospital cardiac arrest of cardiac aetiology between January 1992 and December 1994 and who were covered by ALS services.

INTERVENTIONS

Physician staffed ALS services.

MAIN OUTCOME MEASURES

Return of spontaneous circulation, hospital discharge, and one year survival, according to the Utstein style.

RESULTS

Of 330 000 inhabitants, 755 suffered from cardiac arrest covered by the Heidelberg ALS services. In 512 patients, cardiopulmonary resuscitation had been initiated. Of 338 patients with cardiac aetiology, return of spontaneous circulation was achieved in 164 patients (49%), 48 (14%) were discharged alive, and 40 (12%) were alive one year later; most of these patients showed good neurological outcome. Thus, 4.85 patients with cardiac aetiology were saved by the ALS services and discharged alive per 100 000 inhabitants a year. Ventricular fibrillation or tachycardia was detected in 106 patients (31%), other cardiac rhythms in 40 (12%), and asystole in 192 (57%). Hospital discharge rates (and one year survival) in these subgroups were 34.0% (29.2%), 12.5% (7.5%), and 3.6% (3.1%), respectively. Discharge rates increased if cardiac arrest was witnessed (bystander, 20.0%; BLS/ALS personnel, 21.4%; non-witnessed arrest, 3.3%; p < 0.01), and if the time period between the alarm and the arrival of the ALS unit was four minutes or less (</= 4 minutes, 30.6%; 4-8 minutes, 10.4%; > 8 minutes, 8. 1%; p < 0.001). In 69 patients with bystander witnessed cardiac arrest with ventricular fibrillation, the discharge rate was 37.7%; 21 patients were alive after one year.

CONCLUSIONS

A two tier BLS and physician staffed ALS system is associated with good long term outcome of patients suffering from out-of-hospital cardiac arrest of cardiac aetiology in a midsized urban/suburban area. Further studies, however, are required to assess whether having a physician in the ALS unit is an independent determinant for improved long term outcome.

Fast quantitative diffusion-tensor imaging of cerebral white matter from the neonatal period to adolescence

We investigated the isotropic diffusion coefficient (D') and fractional anisotropy (FA) in white matter (WM) during brain development, using an optimised diffusion-tensor imaging (DTI) method with whole brain coverage in a clinically acceptable time. We images 52 children with no evident neurological abnormality (30 boys, 22 girls aged 1 day-16 years) using high-angle DTI with optimised temporal gradient performance. D' and FA were calculated in 10 regions of interest in white matter. We saw that the age-related reduction in D' and increase in FA follow a mono- or biexponential model in white matter, probably depending on the compactness and myelination rate of the fibre tracts. In contrast to other areas, in which adult values were reached during the third year, there is a trend to continuous increase in FA in all deep white-matter areas, suggesting continuing maturation and organisation of deep tracts not detected on conventional MRI.

Mental number line training in children with developmental dyscalculia

Developmental dyscalculia (DD) is a specific learning disability that affects the acquisition of mathematical skills in children with normal intelligence and age-appropriate school education (prevalence 3-6%). One essential step in the development of mathematical understanding is the formation and automated access to a spatial representation of numbers. Many children with DD show a deficient development of such a mental number line. The present study aimed to develop a computer-based training program to improve the construction and access to the mental number line. Sixteen children with DD aged 8-10 years and 16 matched control children completed the 5-week computer training. All children played the game 15 min a day for 5 days a week. The efficiency of the training was evaluated by means of neuropsychological tests and functional magnetic resonance imaging (fMRI) during a number line task. In general, children with and without DD showed a benefit from the training indicated by (a) improved spatial representation of numbers and (b) the number of correctly solved arithmetical problems. Regarding group differences in brain activation, children with DD showed less activation in bilateral parietal regions, which reflects neuronal dysfunction in pivotal regions for number processing. Both groups showed reduced recruitment of relevant brain regions for number processing after the training which can be attributed to automatization of cognitive processes necessary for mathematical reasoning. Moreover, results point to a partial remediation of deficient brain activation in dyscalculics after consolidation of acquired and refined number representation. To conclude, the present study represents the first attempt to evaluate a custom-designed training program in a group of dyscalculic children and results indicate that the training leads to an improved spatial representation of the mental number line and a modulation of neural activation, which both facilitate processing of numerical tasks.

Astroglial protein S-100 is an early and sensitive marker of hypoxic brain damage and outcome after cardiac arrest in humans

BACKGROUND

The results of early conventional tests do not correlate with cerebral outcome after cardiac arrest. We investigated the serum levels of astroglial protein S-100 as an early marker of brain damage and outcome after cardiac arrest.

METHODS AND RESULTS

In 66 patients undergoing cardiopulmonary resuscitation after nontraumatic cardiac arrest, blood samples for the evaluation of S-100 were drawn immediately after and 15, 30, 45, and 60 minutes; 2, 8, 24, 48, and 72 hours; and 7 days after initiation of cardiopulmonary resuscitation. Moreover, the serum levels of neuron-specific enolase were determined between 2 hours and 7 days. If patients survived for >48 hours, brain damage was assessed by a combination of neurological, cranial CT, and electrophysiological examinations. Overall, 343 blood samples were taken for the determination of S-100. Maximum S-100 levels within 2 hours after cardiac arrest were significantly higher in patients with documented brain damage (survivors and nonsurvivors, 3.70+/-0.77 microg/L) than in patients without brain damage (0.90+/-0.29 microg/L). Significant differences between these 2 groups were observed from 30 minutes until 7 days after cardiac arrest. In addition, the positive predictive value of the S-100 test at 24 hours for fatal outcome within 14 days was 87%, and the negative predictive value was 100% (P<0.001). With regard to neuron-specific enolase, significant differences between patients with documented brain damage and those with no brain damage were found at 24, 48, and 72 hours and 7 days.

CONCLUSIONS

Astroglial protein S-100 is an early and sensitive marker of hypoxic brain damage and short-term outcome after cardiac arrest in humans.