Evaluation of the combination of endothelin receptor antagonists (ERA) and phosphodiesterase-5 inhibitors for the treatment of pulmonary arterial hypertension (PAH) in pathologic human pulmonary arteries in an ex-vivo organ bath model.

PURPOSE: Medical combination therapy of pulmonary arterial hypertension (PAH) may alleviate the drawbacks of monotherapy by avoiding drug tolerance and by increasing effectiveness, as shown by the combination of ambrisentan and tadalafil (AMBITION trial). The present ex-vivo study evaluated the combination of the endothelin receptor antagonists (ERA) macitentan and bosentan with the phosphodiesterase-5 (PDE-5) inhibitor vardenafil in pulmonary arteries from patients suffering from terminal lung disease as a model of PAH. METHODS: Segments of the pulmonary vessels were excised from resected lungs of patients requiring lung transplantation (LTX). Contraction of pulmonary arteries (PA) was elicited by consecutive dose-response curves of endothelin-1 (ET-1) followed by norepinephrine (NE) to allow inhibition by different pathways. Forces were measured isometrically in an organ bath in the presence and absence of ERA and PDE-5 inhibitors and their combination. RESULTS: PA of 38 patients were examined between October 2016 and November 2019. Bosentan (1E-7 M) and macitentan (1E-8 M, 3E-8 M, 1E-7 M) inhibited ET-1 induced contractions, whereas vardenafil (1E-6 M, 3E-6 M, 1E-5 M) inhibited only the NE induced part of the contractions. Vardenafil enhanced bosentan-induced inhibition of vasoconstriction in a dose-dependent fashion. Combination effects exceeded single bosentan at 3E-6 M and 1E-5 M vardenafil, and they exceeded single vardenafil at the lower vardenafil concentrations. Macitentan showed a more pronounced inhibition than bosentan regardless of the lower concentrations. Accordingly, combination effects with vardenafil resembled those of macitentan alone. CONCLUSIONS: Macitentan and bosentan were potent antagonists of vasoconstriction in PA of LTX patients. The benefit of drug combinations was demonstrated at selected concentrations only owing to a narrow therapeutic range of vardenafil in this ex-vivo model. These results suggest the utility of drug combinations other than the established pair of ambrisentan and tadalafil in PAH treatment but also make a case for a further assessment of vasodilator properties of drugs complementing ERA.

Association of Higher CD4+ CD25high CD127low , FoxP3+ , and IL-2+ T Cell Frequencies Early After Lung Transplantation With Less Chronic Lung Allograft Dysfunction at Two Years.

Regulatory T cells (Treg) can regulate alloantigens and may counteract chronic lung allograft dysfunction (CLAD) in lung transplantation. We analyzed Treg in peripheral blood prospectively and correlated percentages of subpopulations with the incidence of CLAD at 2 years. Among lung-transplanted patients between January 2009 and July 2011, only patients with sufficient Treg measurements were included into the study. Tregs were measured immediately before lung transplantation, at 3 weeks and 3, 6, 12, and 24 months after transplantation and were defined as CD4+ CD25high T cells and further analyzed for CTLA4, CD127, FoxP3, and IL-2 expressions. Between January 2009 and July 2011, 264 patients were transplanted at our institution. Among the 138 (52%) patients included into the study, 31 (22%) developed CLAD within 2 years after transplantation. As soon as 3 weeks after lung transplantation, a statistically significant positive association was detected between Treg frequencies and later absence of CLAD. At the multivariate analysis, increasing frequencies of CD4+ CD25high CD127low , CD4+ CD25high FoxP3+ and CD4+ CD25high IL-2+ T cells at 3 weeks after lung transplantation emerged as protective factors against development of CLAD at 2 years. In conclusion, higher frequencies of specific Treg subpopulations early after lung transplantation are protective against CLAD development.

Bronchiolitis obliterans syndrome due to donor-specific HLA-antibodies.

Chronic lung allograft dysfunction (CLAD) is a limiting factor for long-term survival in lung transplant recipients. Donor-specific human leukocyte antigen (HLA)-antibodies (DSA) have been suggested as potential risk factors for CLAD. However, their impact on clinical outcome following lung transplantation remains controversial. We performed a single-center study of 120 lung transplant recipients transplanted between 2006 and 2011. Patient sera were investigated before and after transplantation. The sera were screened by means of Luminex(®) technology (Luminex Inc., Austin, TX, USA) for IgG-HLA-class I and class II antibodies (ab). Using single antigen beads, DSA were identified and correlated retrospectively with clinical parameters. After transplantation 39 out of 120 patients (32.5%) were positive for HLA-ab. The incidence of de novo DSA formation was 27 of 120 patients (22.5%). Eleven of 27 (41%) of de novo DSA-positive patients developed BOS compared to 13 of 93 (14%) DSA-negative patients (p = 0.002). Furthermore, the generation of de novo DSA was independently associated with the development of BOS in multivariable analysis [hazard ration (HR) 2.5, 95% confidence interval (CI) 1.0-6.08; p = 0.046). Our results indicate that de novo DSA are associated with the development of BOS after lung transplantation. Monitoring of HLA-ab after transplantation is useful for identifying high-risk patients and offers an opportunity for early therapeutic intervention.

Resection of pulmonary metastases from colon and rectal cancer: factors to predict survival differ regarding to the origin of the primary tumor.

BACKGROUND: The purpose of the present study was to determine differences in prognostic factors for survival of patients with pulmonary metastases resected in curative intent from colon or rectum cancer. METHODS: Between 1980 and 2006, prognostic factors after resection of pulmonary metastases in 171 patients with primary rectum or colon tumor were evaluated. Survival of patients after surgical metastasectomy was compared with that of patients receiving standard chemotherapy by matched-pair analysis. RESULTS: Median survival after pulmonary resection was 35.2 months (confidence interval 27.3-43.2). One-, 3-, and 5-year survival for patients following R0 resection was 88.8, 52.1, and 32.9 % respectively. Complete metastasectomy (R0), UICC stage of the primary tumor, pleural infiltration, and hilar or mediastinal lymph node metastases are independent prognostic factors for survival. Matched-pair analysis confirmed that pulmonary metastasectomy significantly improved survival. Although no difference in survival for patients with pulmonary metastases from lower rectal compared to upper rectal or colon cancer was observed, factors to predict survival are different for patients with lower and middle rectal cancer (R0, mediastinal and/or hilar lymph nodes, gender, UICC stage) compared with patients with upper rectal or colon cancer (R0, number of metastases). CONCLUSIONS: Our results indicate that distinct prognostic factors exist for patients with pulmonary metastases from lower rectal compared with upper rectal or colon cancer. This supports the notion that colorectal cancer should not be considered as a single-tumor entity. Metastasectomy, especially after complete resection resulted in a dramatic improvement of survival compared with patients treated with chemotherapy alone.

[Modern tailored therapy for pleural empyema]. / Stadienadaptierte moderne Therapie des Pleuraempyems.

In spite of the development and widespread avail-ability of modern antibiotics, pleural empyema still represents a serious intrathoracic disease -associated with significant morbidity and mortality. Patients with complicated parapneumonic effusions and empyema have an increased morbidity and mortality due at least in part to inappropriate and delayed management of pleural space infections. Timely diagnosis of pleural empyema and rapid initiation of the appropriate surgical treatment modality represent keystone principles for efficient treatment of thoracic -empyema. Simple drainage, minimally invasive surgical treatment modalities (VATS) and image-guided small-bore catheters in combination with adjunctive fibrinolytic drugs have extended the potential therapeutic arsenal. Individual case management with a flexible selection of the most appropriate treatment modality by experienced thoracic surgeons may lead to improved outcomes. In this context a summary of the most recent opinions and results in thoracic empyema management is outlined in the present review.

Islets of Langerhans are protected from inflammatory cell recruitment during reperfusion of rat pancreas grafts.

BACKGROUND: Ischemia/reperfusion (I/R) injury plays a pivotal role in the development of graft pancreatitis, with ischemia time representing one of its crucial factors. However, it is unclear, whether exocrine and endocrine tissue experience similar inflammatory responses during pancreas transplantation (PTx). This study evaluated inflammatory susceptibilities of islets of Langerhans (ILH) and exocrine tissue after different preservation periods during early reperfusion. METHODS: PTx was performed in rats following 2 h (2h-I) or 18 h (18h-I) preservation. Leukocyte-endothelial cell interactions (LEI) were analyzed in venules of acinar tissue and ILH in vivo over 2 h reperfusion. Nontransplanted animals served as controls. Tissue samples were analyzed by histomorphometry. RESULTS: In exocrine venules leukocyte rolling predominated in the 2h-I group. In the 18h-I group, additionally, high numbers of adherent leukocytes were found. Histology revealed significant edema formation and leukocyte extravasation in the 18h-I group. Notably, LEI in postcapillary venules of ILH were significantly lower. Leukocyte rolling was only moderately enhanced and few leukocytes were found adherent. Histology revealed minor leukocyte extravasation. CONCLUSION: Ischemia time contributes decisively to the extent of the I/R-injury in PTx. However, ILH have a significantly lower susceptibility towards I/R, even when inflammatory reactions in adjacent exocrine tissue are evident.

Persistence of de novo donor specific HLA-Antibodies after lung transplantation: a potential marker of decreased patient survival.

The impact of de novo donor-specific anti-HLA antibodies (DSA) on outcomes in lung transplantation is still a matter of debate. We hypothesize that differentiating DSA by persistent and transient appearance may offer an additional risk assessment. The clinical relevance of HLA-antibodies was investigated prospectively in 72 recipients with a median follow-up period of 21 months. The presence of HLA-antibodies was analysed by single antigen bead assay prior to and after (3 weeks, 3, 6, 12 and 18 months) transplantation. In 23 patients (32%) de novo DSA were detected. In 10 of these patients (44%) DSA persisted throughout the follow-up period whereas 13 of these patients (56%) had transient DSA. There was a trend towards lower one-year-survival in DSA positive compared to DSA negative patients (83% versus 94%; p=0.199). Remarkably, patients with persistent DSA had significantly reduced survival (one-year survival 60%) compared with both patients without DSA and those with transient DSA (p=0.005). Persistent DSA represented an independent prognostic factor for reduced overall survival in multivariate analysis (HR 8.3, 95% CI 1.8-37.0; p=0.006). Persistence of DSA during the first year after transplantation seems to be more harmful for lung allograft function than transiently detected DSA at an early stage. This article is protected by copyright. All rights reserved.

Effect of pancreatic kallikrein, sperm acrosin and high molecular weight (HMW) kininogen on cervical mucus penetration ability of seminal plasma-free human spermatozoa.

Bradykinin is able to stimulate sperm migration of SPFS; HMW kininogen does not effect sperm migration of SPFS; Kallikrein and acrosin induce small stimulation of sperm migration of SPFS indicating traces of kininogen attached to the sperm surface enabling liberation of kinins; In the presence of kininogen, kallikrein and acrosin significantly improve cervical mucus penetration of SPFS; Lastly, from the presented studies there is experimental evidence that acrosin is involved in stimulation of sperm migration within the female genital tract due to liberation of kinins from kininogen (see Figure 7.).

Hemorrhagic hypotension induces arteriolar vasomotion and intermittent capillary perfusion in rat pancreas.

Hemorrhage-induced intermittent capillary perfusion and its relation to arteriolar vasomotion was studied in rat pancreatic acinar tissue using intravital fluorescence microscopy. During prehemorrhage conditions, microscopic analysis of the pancreatic microcirculation displayed neither arteriolar vasomotion nor intermittency of capillary perfusion (n = 22 animals). Hemorrhage-induced hypotension of 40 mmHg provoked arteriolar vasomotion in 18 of 22 animals and 59 of 115 arterioles studied. The maximum relative amplitude of arteriolar vasomotion was 44 +/- 8% (range 12-81%), and vasomotion frequency averaged 4.73 +/- 0.11 cycles/min. Hemorrhagic hypotension was further accompanied by 1) a decrease of functional capillary density [length of red blood cell-perfused capillaries per area of tissue under investigation (cm/cm2)] from 515 +/- 3 cm-1 at baseline to 386 +/- 3 cm-1 (P < 0.05) and 2) the instantaneous occurrence of intermittency of capillary perfusion in all observation areas (N = 220) of the 22 animals studied. The frequency of intermittency of capillary perfusion (4.72 +/- 0.14 cycles/min) did not differ from the frequency of arteriolar vasomotion, which implies a causal relationship between these two hemorrhage-induced microvascular mechanisms with the probable aim to counteract the decrease of functional capillary density.

Small-volume resuscitation restores hemorrhage-induced microcirculatory disorders in rat pancreas.

OBJECTIVES: Pancreatic hypoxia/ischemia, as a consequence of shock-induced microcirculatory failure, is considered a causative factor in the initiation and/or progression of pancreatic tissue injury. The aim of this study was to compare the effects of "small volume resuscitation" with conventional isovolemic colloid and hypervolemic crystalloid resuscitation on pancreatic microcirculation after hemorrhagic shock. DESIGN: Randomized, controlled intervention trial. SETTING: University laboratory. SUBJECTS: Twenty-three male Sprague-Dawley rats anesthetized with á-chloralose mechanically and ventilated. INTERVENTIONS: Rats subjected to 1 hr of hemorrhagic shock (mean arterial pressure of 40 mm Hg) were resuscitated with lactated Ringer's solution (four-fold shed volume/20 mins), 10% hydroxyethyl starch (shed volume/5 mins), or 7.2% sodium chloride-10% hydroxyethyl starch (10% shed volume/2 mins). MEASUREMENTS AND MAIN RESULTS: The microcirculation of pancreatic acinar tissue was studied by means of intravital fluorescence microscopy and laser Doppler flowmetry. At 1 hr after resuscitation, mean arterial pressure, pancreatic capillary erythrocyte velocity, and erythrocyte flux were found to be significantly increased when compared with those values in the shock state. However, mean arterial pressure, pancreatic capillary erythrocyte velocity, and erythrocyte flux did not completely return to preshock values, regardless of the type of fluid used for resuscitation. At 15 mins and 1 hr after resuscitation, shock-induced capillary perfusion failure (reduction of functional capillary density) was restored to 91% to 94% of baseline values in all groups. Pancreatic capillary narrowing, indicating microvascular endothelial cell swelling, was abolished by resuscitation with both isotonic hydroxyethyl starch and hypertonic hydroxyethyl starch (p<.05 vs. lactated Ringer's solution). CONCLUSIONS: Despite replacement of only 10% of actual blood loss, small-volume resuscitation with hypertonic hydroxyethyl starch is as effective as the ten-fold volume of isotonic hydroxyethyl starch and, due to prevention of microvascular endothelial cell swelling, superior to the 40-fold volume of isotonic lactated Ringer's solution in regard to restoration of the shock-induced microcirculatory disturbances of rat pancreatic acinar tissue.

Effect of caffeine and kallikrein on cryo-preserved human spermatozoa.

Preservation of human semen in liquid nitrogen causes a significant impairment of sperm motility. Ejaculated human spermatozoa show an increased motility in the presence of caffeine, a phosphodiesterase inhibitor, and pancreatic kallikrein (EC 3.4.21.8), a kinin-producing proteinase. Hence, the effect of both substances on post-thaw motility, fructose consumption, and cervical mucus penetration of cryo-preserved human spermatozoa was investigated. The results indicate that both substances stimulate the motility of freshly ejaculated spermatozoa and also improve the motility pattern of cryo-preserved human spermatozoa, thus offering a possible means of improving the quality of freeze-preserved human semen.

[Effect of hypothermic preservation on ICAM-1 mRNA induction, leukocyte-endothelium interaction and microvascular perfusion after pancreas transplantation in the rat]. / Einfluss hypothermer Konservierung auf ICAM-1 mRNA Induktion, Leukozyten-Endothel Interaktion und mikrovaskuläre Perfusion nach Pankreastransplantation bei der Ratte.

A prolonged period of 18 h hypothermic preservation in pancreas grafts led to a significant induction of ICAM-1 mRNA, enhanced leukocyte-adherence/-extravasation and compromised microvascular perfusion upon 2 h of reperfusion when compared to a 2 h preservation period. Therefore, during the period of prolonged cold ischemia changes within the graft must take place causing a reinforced ICAM-1 mRNA-induction already early after the onset of reperfusion. These results underline the relevance of the ischemia/reperfusion injury for the development of complications arising in the early course following pancreas transplantation.

[MR angiography of the supraaortic vessels]. / MR-Angiographie der supraaortalen Gefässe.

PURPOSE: To compare high resolution contrast-enhanced MR angiography (MRA) and digital subtraction angiography (DSA) in the assessment of supraaortic vessel stenosis. METHODS: 14 patients with suspicion of cerebrovascular disease or upper limb ischemia underwent selective DSA and high resolution contrast enhanced MRA employing a new Panoramic-Array coil. Stenosis assessment in comparison to DSA followed NASCET criteria. Additionally signal-/noise ratios (SNR) were evaluated to assess contrast enhancement. RESULTS: Diagnostic image quality was achieved in all patients. Sensitivity and specificity for assessing high-grade stenosis of the supraaortic vessels were 100% and 96% respectively. In the assessment of high-grade common or internal carotid artery stenosis sensitivity and specificity was 100%. CONCLUSION: High resolution contrast enhanced supraaortic MRA combined with new coil systems allow for a reliable assessment of stenoses along the whole vessel course including the aortic arch. Previous stent procedures limit its use in postinterventional follow-up.