Esophagojejunal reconstruction after total gastrectomy for gastric cancer using a transorally inserted anvil delivery system.

INTRODUCTION: Total gastrectomy (TG) is commonly performed for the treatment of patients with gastric cancer. However, reconstruction of the esophagojejunal (EJ) anastomosis can be technically demanding, with reported anastomotic leak rates in the Western world still approaching 10-15%. We report our experience using the transoral anvil delivery system (OrVil™) for creation of the EJ anastomosis after TG. METHODS: From 2007 to 2011, 48 consecutive patients with gastric cancer underwent open (n=31) or laparoscopic (n=17) TG. EJ reconstruction was performed with the transoral anvil deliver system (OrVil™) in an end-to-side fashion. Demographic, clinic, and perioperative data were obtained from a prospectively maintained database. RESULTS: Of the 48 patients, 83% were male. Median age at resection was 64 years. Median body mass index was 27.1 kg/m2. Seventy-nine percent (n=38) of patients had at least one comorbidity. Fifteen patients (31%) had at least one perioperative complication. There was one perioperative death (2%) following a duodenal stump leak. There were four EJ leaks (8%) and two EJ stenoses (independent of leak; 4%). There was one EJ leak (6%) and one EJ stenosis (6%) following a case that was first attempted laparoscopically. There were no deaths as a consequence of an EJ leak. CONCLUSIONS: The use of the transoral anvil delivery system during EJ reconstruction is a safe and effective option for reconstruction after open or laparoscopic TG with acceptable mortality and morbidity. The anastomotic leak rate appears to be comparable to that of other techniques.

Requirement of a plasma fraction for the loss of large von Willebrand factor multimers induced by high wall shear rate.

The perfusion of serum, citrated whole blood and citrated plasma, through a simple tube system resulted in a significant loss of large von Willebrand factor (vWf) multimers, without decrease in antigen levels. Maximum loss of large multimers was observed at a shear rate of 15,000 s-1 for 15 min. Heparin, aprotinin, soybean trypsin inhibitor, phenylmethylsulphonylfluoride, N-ethylmaleimide, leupeptin or calpain inhibitor peptide could not prevent the loss of large vWf multimers in citrated plasma. The addition of EDTA calcium salt partially prevented it, and it was totally prevented by EDTA without calcium. Perfusion of purified vWf did not induce the loss of large multimers, but this did happen after the addition of either whole serum or a plasma fraction. The activity of this plasma fraction disappeared at pH < 6.8. Besides, we have found that the binding to subendothelium of purified vWf diluted in dialyzed serum was lower at pH 7.2 than at pH 6.0. Chromatographic studies demonstrated that the loss of large vWf multimers, induced by high shear rates, involves a plasma substance(s) of molecular weight larger than 200 kD; calpain and granulocyte or cysteine proteases do not seem to be this plasma substance(s).

Platelet aggregation inhibition by mononuclear leukocytes.

In this study we have investigated the effect of human mononuclear leukocytes (ML) on platelet aggregation. The results obtained demonstrated that coincubation of platelets with nonstimulated ML decreased platelet aggregation induced by collagen or thrombin in a concentration-dependent manner. The inhibitory effect increased with the incubation period of the cells, reaching a plateau at 5 minutes. T and non-T enriched ML suspensions exerted an inhibitory effect similar to the total population of ML. Supernatants from ML or mixed cell suspensions also diminished platelet aggregation. 6-keto PGF1 alpha concentration in the supernatants was less than 10 pg/ml. Hemoglobin, L-arginine and cytochrome C did not modify the antiaggregating activity of ML, whereas superoxide dismutase potentiated the inhibition of aggregation mediated by ML. The inhibitory effect was not modified by monoclonal antibody (MoAb) against the lymphocyte function-associated antigen 1, alpha subunit (LFA-1 alpha) or by a MoAb directed against P-selectin. Our results demonstrated that ML inhibited platelet aggregation, at least partially, by the release of a soluble factor(s) distinct of prostacyclin or nitric oxide. Surface adhesion molecules seem also not to be involved.

Interferon-gamma enhances PAF-acether production by stimulated human polymorphonuclear leucocytes.

Human polymorphonuclear leucocytes (PMN) stimulated with either immune complexes (IC), phorbol myristate acetate (PMA) or N-formyl-methionyl-leucyl-phenylalanine (FMLP) generate platelet-activating factor (PAF-acether). The present study demonstrates that treatment of PMN with recombinant human interferon-gamma (IFN-gamma) significantly enhanced the production of PAF-acether by stimulated cells, in a concentration-dependent mode. On the contrary, alpha and beta IFN were completely unable to increase PAF-acether synthesis by stimulated PMN. The significance of these results is discussed.

Inhibition of human platelet activation by polymorphonuclear leukocytes.

1. The effect of unstimulated human polymorphonuclear leukocytes (PMNs) on platelet activation was examined. 2. Human platelet aggregation and adenosine 5'-triphosphate (ATP) release induced by collagen (1-2 micrograms ml-1); thrombin (0.01-0.02 u ml-1) or arachidonic acid (AA) (0.1-0.2 mM) were markedly inhibited when conducted in the presence of unstimulated PMNs. 3. Platelet inhibition induced by PMNs was dependent on the number of PMNs and on the incubation time of the mixed cell suspension. 4. Platelet inhibition was not reversed in time when PMNs were depleted from the mixed-cell suspension. 5. PMN-mediated platelet-inhibition was not mediated by AA metabolites, oxygen reactive intermediates, nitric oxide or proteases. 6. The factor(s) accounting for the platelet inhibition mediated by PMNs are not yet characterized.

The influence of sex and different segments of thoracic aorta on bioactive aortic substance (BAS) and prostacyclin (PGI2) synthesis.

BAS is a protein generated by aortic rings isolated from rats. Our previous results clearly established that BAS inhibits platelet aggregation and modifies vascular tone. We have now examined the effect of separated segments of thoracic aorta and the effect of sex on the release of the BAS and PGI2. We evaluated three different segments of thoracic aorta: A = aortic arch, B = the upper segment and C = the lowest segment of the thoracic aorta. We measured the release of BAS and PGI2 from them. The BAS production increased in the first segment (A) when compared with the other two (B and C), whilst PGI2 production was the same along the thoracic aorta. On the other hand female and male thoracic aorta produced the same levels of BAS and 6-keto PGF1 cm.

Reacción de liberación en tromboastenia de Glanzmann / Release reaction in Glanzmanns thrombasthenia

Se estudiaron siete pacientes con tromboastenia de Glanzmann. Se realizó agregación plaquetaria con reacción de liberación en un agregómetro Lumi. No se observó agregación con ADP, adrenalina o colágeno. El ácido araquidónico indujo una agregación de sólo 14,9%. Con ristocetina y con factor VIII bovino la aglutinación fue marcadamente disminuida. La liberación de ATP estuvo ausente con todos los agentes agregantes excepto con ácido araquidónico que provocó una liberación normal. Se realizó curva dosis respuesta con análogo de PGH2. Con dosis de 1 micronM a 100 micronM sólo se obtuvo una mínima agregación mientras que la liberación de ATP fue normal. Los resultados confirmarían la independencia de los mecanismos de agregación y liberación. La liberación de ATP inducida por ácido araquidónico o análogo de endoperóxido no parece requerir la exposición y fijación del fibrinógeno a su receptor (AU)

Reacción de liberación en tromboastenia de Glanzmann / Release reaction in Glanzmann's thrombasthenia

Se estudiaron siete pacientes con tromboastenia de Glanzmann. Se realizó agregación plaquetaria con reacción de liberación en un agregómetro Lumi. No se observó agregación con ADP, adrenalina o colágeno. El ácido araquidónico indujo una agregación de sólo 14,9%. Con ristocetina y con factor VIII bovino la aglutinación fue marcadamente disminuida. La liberación de ATP estuvo ausente con todos los agentes agregantes excepto con ácido araquidónico que provocó una liberación normal. Se realizó curva dosis respuesta con análogo de PGH2. Con dosis de 1 micronM a 100 micronM sólo se obtuvo una mínima agregación mientras que la liberación de ATP fue normal. Los resultados confirmarían la independencia de los mecanismos de agregación y liberación. La liberación de ATP inducida por ácido araquidónico o análogo de endoperóxido no parece requerir la exposición y fijación del fibrinógeno a su receptor

Platelet aggregating substance from mononuclear leukocytes.

Human peripheral blood mononuclear leukocytes (ML) in suspension stimulated with arachidonic acid (AA) were able to induce platelet aggregation. Shape change followed by first and second wave aggregation was the pattern of the platelet response. ML not treated with AA did not induce platelet aggregation nor did AA done at the concentration employed. The aggregating activity was not due to the ML presence, since cell-free supernatants of ML stimulated with AA induced similar platelet aggregation as the whole suspension. Aspirin incubated with ML-AA produced 65% reduction of the above aggregatory activity described while 38% and 45% reduction was obtained when ML-AA was incubated with 5, 8, 11, 14 eicosatetraynoic acid (ETYA) and nordihydroguaiaretic acid (NDGA). Complete platelet cyclooxygenase integrity was necessary to obtain the second wave of aggregation induced by ML-AA, while this was not required for the first wave response. We propose that ML-AA are able to produce a platelet activating substance(s) derived from AA metabolism involving cyclo and lipoxygenase actions. It is unlikely that this substance(s) is a hydroperoxyfatty acid or thromboxane A2 (TXA2) since it is active for at least two hours once generated.

Rat's vessel wall generates an antiaggregatory substance independent of prostacyclin production.

We have investigated whether the vessel wall may release or synthetize some substance able to modify the platelet function independent of prostacyclin (PGI2) production. Twenty female rats were injected with indomethacin. 18 hours after the injection animals were sacrificed and rings cut from thoracic and abdominal aorta were obtained. They were incubated in Krebs solution for different periods of time after which an aliquot from the indomethacin treated rat's aortic ring (ITRAR) was assayed on platelet aggregation induced by several agonists. The supernatant from the 40 min. incubation mixture of ITRAR released a substance which completely inhibits platelet aggregation induced by arachidonic acid (AA), ADP, epinephrine, collagen, ristocetin and thrombin. The time of appearance of the substance varied with a mean of 17 min.. It is released with and without AA stimulation. Once generated it is active for at least three hours; its antiaggregating activity remains even if it is boiled for 15 sec, incubated at 37 degrees C, or if the vessel is treated with tranylcypromine. Platelet aggregation inhibition is still evident if the supernatant from ITRAR is transferred to a platelet rich plasma (PRP) from a normal donor who had taken an aspirin 24 hours before sampling. All these results indicate that this substance released from ITRAR is not prostacyclin. Nordihydroguaiaretic or eicosatetraynoic acid which are lipoxygenase inhibitors could not modify the ITRAR's release; nor did mepacrine which is a phospholipase inhibitor. Since mepacrine does not completely inhibit phospholipase activities we cannot exclude the possibility that the substance is derived from AA. More studies are in progress to elucidate the biochemical properties of this substance.

Human lymphocyte aggregation?

The purpose of the present study was to assess lymphocyte (L) aggregation. Mononuclear cells were obtained according to Boÿum. Blood was defibrinated with glass beads and laid on Ficoll-Hypaque gradients. Monocyte depletion was achieved by adherence to plastic for 18 hs. L aggregation was assayed using the turbidimetric method. When L were challenged with collagen (1-8 micrograms/ml), ADP (2.5 microM), epinephrine (1 X 10(-4) M), ristocetin (1.5 mg/ml) and bovine F VIII no aggregation could be observed. When L were stimulated by arachidonic acid (AA) (160 microM) a complete and irreversible aggregation was obtained. This effect was markedly inhibited when L were previously incubated with aspirin (40 micrograms/ml). On the other hand 5, 8, 11, 14 eicosatetraynoic acid (ETYA), a lypoxygenase inhibitor, was not able to reverse L aggregation induced by AA. Leukotriene B4, C4 and D4 were not able to induce L aggregation. When TXA2 like material from platelets and L was transferred to L preincubated with aspirin a normal aggregation response was obtained. All these results lead to the concept that the main pathway involved in L AA metabolism is probably cyclo-oxygenase. Ionophore A 23187 was not able to induce L aggregation at any concentration employed (0.1 - 100 microM) and 6 keto PGE1 could not inhibit AA induced lymphocyte aggregation.