Locoregional recurrences after transanal total mesorectal excision of rectal cancer during implementation.

BACKGROUND: Transanal total mesorectal excision (TaTME) has been proposed as an approach in patients with mid and low rectal cancer. The TaTME procedure has been introduced in the Netherlands in a structured training pathway, including proctoring. This study evaluated the local recurrence rate during the implementation phase of TaTME. METHODS: Oncological outcomes of the first ten TaTME procedures in each of 12 participating centres were collected as part of an external audit of procedure implementation. Data collected from a cohort of patients treated over a prolonged period in four centres were also collected to analyse learning curve effects. The primary outcome was the presence of locoregional recurrence. RESULTS: The implementation cohort of 120 patients had a median follow up of 21·9 months. Short-term outcomes included a positive circumferential resection margin rate of 5·0 per cent and anastomotic leakage rate of 17 per cent. The overall local recurrence rate in the implementation cohort was 10·0 per cent (12 of 120), with a mean(s.d.) interval to recurrence of 15·2(7·0) months. Multifocal local recurrence was present in eight of 12 patients. In the prolonged cohort (266 patients), the overall recurrence rate was 5·6 per cent (4·0 per cent after excluding the first 10 procedures at each centre). CONCLUSION: TaTME was associated with a multifocal local recurrence rate that may be related to suboptimal execution rather than the technique itself. Prolonged proctoring, optimization of the technique to avoid spillage, and quality control is recommended.

ANTECEDENTES: La escisión total del mesorrecto por vía transanal (Transanal Total Mesorectal Excision, TaTME) se ha propuesto como abordaje quirúrgico en pacientes con cáncer de recto medio e inferior. La técnica TaTME se ha introducido en los Países Bajos mediante un proceso de formación estructurado que incluye la supervisión. Este estudio evaluó el porcentaje de recidiva local durante la fase de implementación de TaTME. MÉTODOS: Se recogieron los resultados oncológicos de los primeros 10 procedimientos realizados mediante TaTME en cada uno de los 12 centros participantes como parte de una auditoría externa de implementación del procedimiento. Se reunió una cohorte más amplia de pacientes procedentes de 4 centros para analizar los efectos de la curva de aprendizaje. El criterio de valoración principal fue la presencia de recidiva locorregional. RESULTADOS: La cohorte de implementación de 120 pacientes tuvo una mediana de seguimiento de 21,9 meses. Los resultados a corto plazo incluyeron una tasa del margen de resección circunferencial positivo del 5% y una tasa de fuga anastomótica del 17,4%. La tasa global de recidiva local en la cohorte de implementación fue del 10% (12/120) con un intervalo medio de recidiva de 15,2 (DE 7) meses. El patrón de recidiva local fue multifocal en 8 de 12 casos (67%). En la cohorte ampliada (n = 266), la tasa global de recidiva fue del 5,6% (4,0%, excluyendo a los primeros 10 pacientes). CONCLUSIÓN: TaTME se asoció con un porcentaje de recidiva local multifocal que puede relacionarse con una ejecución subóptima, más que con la técnica en sí. Se recomienda una supervisión prolongada, la optimización de la técnica para evitar la diseminación tumoral, así como un control de calidad.

Combined abdominoplasty and stoma repositioning: A successful approach for addressing stomal retraction and problematic stoma care: A case study.

INTRODUCTION: This case report discusses the management of challenging stoma care in an overweight patient, focusing on the successful application of abdominoplasty combined with stoma repositioning. The increasing abdominal mass in overweight patients often leads to stoma retraction and mechanical stress, necessitating innovative and less invasive interventions. CASE PRESENTATION: The subject is a 40-year-old female with a body mass index of 28.41 kg/m2, who was experiencing complications in stoma care due to recent weight gain. Through a collaborative effort between a plastic and a general surgeon, the patient underwent abdominoplasty combined with stoma repositioning, leading to significant improvements in stoma care and cosmetic results. DISCUSSION: Despite the limited amount of literature on abdominoplasty combined with stoma revision, this case report contributes to the evidence supporting it as an effective alternative for persistent stoma dysfunction in overweight patients. This innovative surgical approach represents a viable solution to address stomal retraction and leakage. CONCLUSION: The case report underscores the potential benefits of abdominoplasty combined with stoma repositioning in overweight patients with persistent stoma care problems. Although the risk of wound contamination must be taken into account, this combined procedure can enhance patient outcomes. The study provides valuable insights for healthcare professionals managing stoma care in overweight patients.

N(epsilon)-(carboxymethyl)lysine depositions in intramyocardial blood vessels in human and rat acute myocardial infarction: a predictor or reflection of infarction?

OBJECTIVE: Advanced glycation end products (AGEs), such as N(epsilon)-(carboxymethyl)lysine (CML), are implicated in vascular disease. We previously reported increased CML accumulation in small intramyocardial blood vessels in diabetes patients. Diabetes patients have an increased risk for acute myocardial infarction (AMI). Here, we examined a putative relationship between CML and AMI. METHODS AND RESULTS: Heart tissue was stained for CML, myeloperoxidase, and E-selectin in AMI patients (n=26), myocarditis patients (n=17), and control patients (n=15). In AMI patients, CML depositions were 3-fold increased compared with controls in the small intramyocardial blood vessels and predominantly colocalized with activated endothelium (E-selectin-positive) both in infarction and noninfarction areas. A trend of increased CML positivity of the intima of epicardial coronary arteries did not reach significance in AMI patients. In the rat heart AMI model, CML depositions were undetectable after 24 hours of reperfusion, but became clearly visible after 5 days of reperfusion. In line with an inflammatory contribution, human myocarditis was also accompanied by accumulation of CML on the endothelium of intramyocardial blood vessels. CONCLUSIONS: CML, present predominantly on activated endothelium in small intramyocardial blood vessels in patients with AMI, might reflect an increased risk for AMI rather than being a result of AMI.

Differences between rabbit sinoatrial pacemakers in their response to Mg, Ca and temperature.

The rabbit sinoatrial node is functionally inhomogeneous with respect to its response to changes in Mg concentration (0.6 to 6.0 mmol X litre-1) and in Ca concentration (1.1 to 2.2 mmol X litre-1) and to changes in experimental temperature (30 to 38 degrees C). High Mg (6.0 mmol X litre-1) stabilises the position of the leading pacemaker. This pacemaker decelerates under high Mg, but the subsidiary ones decelerate even more. Consequently when a subsidiary pacemaker turns dominant--eg under low Ca or at low temperature--an enhanced chronotropic response to high Mg is observed. The superior (cranial) part of the rabbit sinoatrial node is more responsive to changes in Ca concentration than the inferior (caudal) part. The same holds true for changes in temperature.

Inactivation of factor Xia in vivo: studies in chimpanzees and in humans.

C1-inhibitor (C1Inh), antithrombin III (ATIII), alpha 1-antitrypsin (a1AT), and alpha 2-antiplasmin (a2AP) are known inhibitors of factor XIa (FXIa). However, their precise contribution to FXIa inactivation in vivo is not known. We investigated FXIa inactivation in chimpanzees and assessed the contribution of these inhibitors to FXIa inactivation in patients with presumed FXI activation. Chimpanzees were infused with FXIa and the various FXIa-FXIa inhibitor complexes formed were measured. Most of FXIa was complexed to C1Inh (68%), followed by a2AP (13%), a1AT (10%), and ATIII (9%). Analysis of the plasma elimination kinetics revealed a half-life time of clearance (t1/2) for the FXIa-FXIa inhibitor complexes of 95 to 104 min, except for FXIa-a1AT, which had a t1/2 of 349 min. Due to this long t1/2, FXIa-a1AT complexes were predicted to show the highest levels in plasma samples from patients with activation of FXI. This was indeed shown in patients with disseminated intravascular coagulation, recent myocardial infarction or unstable angina pectoris. We conclude from this study that in vivo C1Inh is the predominant inhibitor of FXIa, but that FXIa-a1AT complexes due to their relatively long t 1/2 may be the best parameter to assess FXI activation in clinical samples.

Comprehensive TP53-denaturing gradient gel electrophoresis mutation detection assay also applicable to archival paraffin-embedded tissue.

A comprehensive mutation detection assay is described for the entire coding region and all splice site junctions of TP53. The assay is based on denaturing gradient gel electrophoresis, which follows either multiplex polymerase chain reaction (PCR) applied to DNA extracted from fresh or frozen tissue samples or nested PCR applied to DNA extracted from paraffin-embedded tissue samples. In both instances, the analysis can be performed under a single set of conditions. When testing the assay on DNA from cultured lung cancer cell lines and from paraffin-embedded Dukes C colorectal carcinomas, significant TP53 mutations were observed at high frequencies in 15 of 16 lung cancer cell lines (94%) and in 21 of 30 paraffin-embedded tissue samples of Dukes C colorectal carcinomas (70%). A substantial proportion of these significant mutations occurred outside the evolutionary conserved region of TP53 in 4 of 16 lung cancer cell lines (25%) and in 11 of 30 paraffin-embedded colorectal carcinomas (37%). This underscores the importance of a comprehensive TP53 mutation analysis in those instances that TP53 mutation is taken into account for diagnostic and prognostic purposes.

Detection of erythrocyte membrane components in hemoglobin-based blood substitutes.

Two methods for the detection of membrane components in human stroma-free hemoglobin solutions are described. The first is a phospholipid assay with a detection limit of 0.5-1 nmol phospholipid/ml hemoglobin-solution. For the detection of membrane proteins an immunoassay with a monoclonal antibody against glycophorin alpha was developed (detection limit 0.01% of the original amount). These methods were used to determine the purity of Hb solutions prepared in two different ways. Hb solutions prepared by filtration of red blood cells, gradually swollen in hypotonic buffer, contained 0.25% of the original amount of phospholipid and no detectable glycophorin alpha. For Hb solutions prepared in a similar way from red blood cells lysed in water, the values for phospholipid and glycophorin alpha were 2.5% and 0.06%, respectively. The determination of both glycophorin alpha and phospholipid gives a useful indication of the purity of Hb solutions.

The potentiation of human C1-inhibitor by dextran sulphate is transient in vivo: studies in a rat model.

C1-inhibitor (C1-Inh) is an important regulator of inflammatory reactions because it is a potent inhibitor of the contact and complement system. C1-Inh application in inflammatory disease is, however, restricted because of the high doses required. The glycosaminoglycan-like molecule dextran sulphate (DXS) enhances C1-Inh function in vitro. Hence, we investigated whether co-administration with dextran sulphate reduces the amount of C1-Inh required, through enhancement in vivo. C1-Inh potentiation was measured in a newly developed C1s-inactivation assay that is based on activation of C4 by purified C1s. Activated C4 in rat plasma was quantified with a newly developed ELISA. Human C1-Inh (2.5 microM) inhibited C1s in rat plasma 55-fold faster in the presence of dextran sulphate (15 kDa, 5 microM). To study the stability of the complex in vivo, rats were given a mixture of C1-Inh (10 mg/kg) and dextran sulphate (3 mg/kg). C1-Inh activity during 5 h was analyzed ex vivo with the C1s inactivation assay. The noncovalent C1-Inh-dextran sulphate complex resulted in a transient enhancement of the inhibitory capacity of C1-Inh, lasting for 60-90 min. Dextran sulphate did not affect plasma clearance of C1-Inh. We conclude that the enhanced inhibitory capacity of C1-Inh complexed to dextran sulphate is transient in vivo. Hence, co-administration of these compounds seems a feasible approach to achieve short-term inhibition of complement in vivo.

Long-term disease-free survival after isolated peritoneal metastasis from colonic cancer.

We present the case of a 29-year-old female patient with an isolated peritoneal metastatic mass in the Douglas pouch, following ileocecal resection for a Dukes C2 colon cancer of the caecum. As initial treatment, four courses of continuous infusion with epiadriamycin were administered. The effect on the tumour size was marginal. Palliative radiotherapy (33 Gy) resulted in a reduction of the tumour size and subsequently a wide posterior exenteration could be performed. Five years after the initial diagnosis the patient is still in good health with no evidence of tumour recurrence. We sincerely believe that a maximum effort aiming for cure is warranted in selected patients with localized residual or metastatic peritoneal colon cancer, even if the initial prospects seem less favourable.

Oxygen affinity of hemoglobin solutions modified by coupling with NFPLP and the effects on tissue oxygenation in the isolated perfused rat liver.

From these liver perfusions with Hb and Hb/HbNFPLP solutions the following conclusions can be drawn: In spite of the chemical modification of the hemoglobin molecule, no rheological differences are seen. All parameters measured were sensitive to hypoxia induced by a decrease in perfusion flow rate. The NFPLP-induced decrease in oxygen affinity was reflected in a higher venous PO2. These in-vivo observations are in agreement with the in-vitro measured oxygen dissociation curves. The difference in PO2 did not result in a change in the other oxygen-sensitive parameters in this model under the chosen conditions. Possible causes for these observations are: the level of hypoxia was too low the oxygen supply in the perfusions with the modified hemoglobin solutions was lower than the oxygen supply in the perfusions with normal hemoglobin. Whether or not this observation is due to an intrinsic property of the modified hemoglobin molecule remains to be established.

Accumulation of human EGF in nectar of transformed plants of Nicotiana langsdorffii x N. sanderae and transfer to honey by bees.

Honey has been used successfully in wound healing for thousands of years. The peptide hormone human epidermal growth factor (hEGF) is also known to have a beneficial effect in various wound healing processes via mechanisms that differ from those for honey. In this study, we show that hEGF can be incorporated into honey via nectar. Plants of Nicotiana langsdorffii x N. sanderae were transformed with the gene for hEGF, equipped with a nectary-targeted promoter and a signal sequence for secretion to nectar. These plants accumulated hEGF in the nectar. The maximum hEGF concentration recorded with ELISA in these plants is 2.5 ng·ml⁻¹. There is a significant linear relationship (P<0.001) between hEGF concentration and induction of hEGF-receptor phosphorylation. Since the flower morphology of these plants did not allow production of honey from their nectar, we used feeding solutions, spiked with synthetic hEGF, to study transfer of this peptide into honey through bee activity. Transfer of hEGF from a feeding solution to honey by bees occurred with retention of the hEGF concentration and the capacity to induce hEGF-receptor phosphorylation. These observations indicate that plants can function as a production platform for honey containing biologically active peptides, which may enhance wound healing and other biological processes.

Human kappa light chain targeted Pseudomonas exotoxin A--identifying human antibodies and Fab fragments with favorable characteristics for antibody-drug conjugate development.

Antibody-drug conjugates (ADC) represent promising agents for targeted cancer therapy. To allow rational selection of human antibodies with favorable characteristics for ADC development a screening tool was designed obviating the need of preparing individual covalently linked conjugates. Therefore, α-kappa-ETA' was designed as a fusion protein consisting of a human kappa light chain binding antibody fragment and a truncated version of Pseudomonas exotoxin A. α-kappa-ETA' specifically bound to human kappa light chains of human or human-mouse chimeric antibodies and Fab fragments. Antibody-redirected α-kappa-ETA' specifically inhibited proliferation of antigen-expressing cell lines at low toxin and antibody concentrations. Selected antibodies that efficiently delivered α-kappa-ETA' in the novel assay system were used to generate scFv-based covalently linked immunotoxins. These molecules efficiently triggered apoptosis of target cells, indicating that antibodies identified in our assay system can be converted to functional immunoconjugates. Finally, a panel of human epidermal growth factor receptor (EGFR) antibodies was screened--demonstrating favorable characteristics with antibody 2F8. These data suggest that antibodies with potential for Pseudomonas exotoxin A-based ADC development can be identified using the novel α-kappa-ETA' conjugate.

Hybrid zones between invasive Rorippa austriaca and native R. sylvestris (Brassicaceae) in Germany: ploidy levels and patterns of fitness in the field.

Hybrid zones may serve as natural laboratories for evolutionary studies. One common viewpoint is that hybrids may always be less fit than their parents due to genetic discontinuities. An alternative idea is that genotype-environment interactions influence the outcome of natural hybridization. Our comparative study of two different natural hybrid zones between the invasive diploid Rorippa austriaca and the native polyploid R. sylvestris in Germany identified the ploidy level as a major determinant of hybrid fitness. Different ploidy levels and patterns of fitness were detected in different hybrid zones. In one hybrid zone (Mülheim, Ruhr valley) hybrids were pentaploid and showed a relatively high seed set, whereas in the second hybrid zone (Randersacker, Main valley) hybrids were triploid and displayed extremely low fitness values. Analyses of fitness values in different natural hybrid zones between the same two species may lead to very different conclusions about the evolutionary significance of natural hybridization.

Hybridization and Rorippa austriaca (Brassicaceae) invasion in Germany.

Introgressive hybridization between the invasive Rorippa austriaca and the native R. sylvestris in Germany has been studied using chloroplast DNA (trnL intron) and amplified fragment length polymorphism. Three hybrid zones between the invasive and native species were located in the Ruhr Valley (Mülheim) and at the River Main near Würzburg (Randersacker, Winterhausen). In each hybrid zone hybridization was indicated by additivity of region-specific amplified fragment length polymorphism markers proving independent hybridization events. The hybrids were either morphologically intermediate (R. x armoracioides) or were close to R. sylvestris. The trnL intron of R. austriaca is characterized by a species-specific deletion. This diagnostic chloroplast marker of R. austriaca was detected in three individuals of R. sylvestris providing evidence for introgression of the invasive chloroplast into the native species. Bidirectional introgression of R. austriaca markers into R. sylvestris and of R. sylvestris markers into R. austriaca was detected in the amplified fragment length polymorphism analysis. Some of the invasive R. austriaca populations showed high within-population variation. A possible association among introgression, within-population variation and invasion success is discussed. The morphologically intermediate hybrid R. x armoracioides is currently spreading in northern Germany. It forms large populations without its parent species R. austriaca and R. sylvestris. It is concluded that hybridization between invasive R. austriaca and native R. sylvestris may lead to the evolution of a new invasive species R. x armoracioides.

Introgressive hybridization in Rorippa (Brassicaceae): gene flow and its consequences in natural and anthropogenic habitats.

Introgressive hybridization between three Rorippa species (R. amphibia, R. palustris and R. sylvestris) in northern Germany has been studied using isozymes and noncoding chloroplast DNA (trnL/F spacer). Our results provide substantial evidence for different patterns of gene flow in natural and in anthropogenic environments. Hybridization and bi-directional introgression (chloroplast DNA and allozymes) between R. amphibia and R. sylvestris were detected at the river Elbe, which is one of the last rivers in Central Europe showing a natural dynamic of erosion and sedimentation. The natural dynamic of the Elbe leads to periodic habitat disturbance and the temporal breakdown of ecological isolation barriers between R. amphibia and R. sylvestris. However, the high dynamic does not provide the opportunity for persistence of the morphologically intermediate hybrid R. x anceps (R. amphibia x R. sylvestris). We did not find hybrid zones between R. amphibia and R. sylvestris in the more anthropogenic landscape of northwest Germany. However, contact zones between R. amphibia and R. palustris were detected in drainage ditches in northwest Germany. We found substantial evidence for unidirectional introgression of R. palustris markers (chloroplast DNA and allozymes) into R. amphibia in the man-made habitats. The R. amphibia introgressants in the drainage ditches often showed strongly serrate upper cauline leaves instead of the entire upper cauline leaves typical for R. amphibia. We argue that landscape melioration in northwest Germany, particularly the creation of drainage ditches, favoured both hybrid-zone formation and ecotypic differentiation within R. amphibia.

The plasma membrane of leading pacemaker cells in the rabbit sinus node. A qualitative and quantitative ultrastructural analysis.

We studied the fine structure of the plasma membrane of electrophysiologically identified leading pacemaker cells from the rabbit sinus node, using both ultrathin sections of fixed tissue and replicas of freeze-cleaved material. We found that differences exist between sinus node and working myocardial membranes, but these are only quantitative. The caveolae or sarcolemmal invaginations are present in very large numbers; they increase the surface area of the plasma membrane by about 100%. The small macular nexuses that are present represent 0.2% of the membrane surface area. Nexuses are therefore about 10 times less numerous in leading sinus node cells than in working myocardium cells. A single equivalent electrical representation of the sinus node shows, nevertheless, that an appreciable electrical coupling may be expected.

Accelerated autoantibody clearance by intravenous immunoglobulin therapy: studies in experimental models to determine the magnitude and time course of the effect.

Recently, it has been postulated that the beneficial effect of intravenous immunoglobulins (IVIGs) in antibody-mediated autoimmune disorders is based on accelerated catabolism of autoantibodies. In the current study, in vivo experiments were performed with mice in which autoantibody production was mimicked by continuous infusion of monoclonal antibodies. In this model, a single dose of IVIG reduced the plasma concentrations of the infused immunoglobulin (Ig)G1 monoclonal antibody (mAb) by approximately 40% after 3 days, whereas the concentration of an IgA mAb was not affected. To extrapolate these findings to humans, a computational model for IgG clearance was established that accurately predicted the time course and magnitude of the decrease in IgG plasma levels observed in mice. Adapted for humans, this model predicted a gradually occurring decrease in autoantibody levels after IVIG administration (2 g/kg), with a maximum reduction of approximately 25% after 3 to 4 weeks and a continued decrease of several months. In conclusion, a single high dose of IVIG induces a relatively small but long-lasting reduction of autoantibody levels by accelerated IgG clearance. This mechanism has clinical relevance in the sense that it can fully explain, as the sole mechanism, the gradual decrease in autoantibody levels observed in several patient studies. However, in some clinical studies, larger or more rapid effects have been observed that cannot be explained by accelerated clearance. Hence, IVIG can also reduce autoantibody levels through mechanisms such as down-regulation of antibody production or neutralization by anti-idiotypic antibodies.