Brain death impairs coronary endothelial function

BACKGROUND: To characterize the impact of brain death (BD) on endothelial dysfunction after cardiac transplantation we investigated coronary circulation and vasomotor function in a canine model. METHODS: Left ventricular pressure-volume data (conductance catheter) and coronary blood flow (CBF) were monitored continuously. Endothelium-dependent vasodilatation after acetylcholine and endothelium-independent vasodilation after sodium nitroprusside were assessed before and 3 hr after BD induction (inflation of a subdural balloon). RESULTS: BD led to an initial hyperdynamic reaction with significant (P<0.05) increase of CBF. After 3 hr, CBF decreased significantly (P<0.05). Although before BD, application of acetylcholine led to a monophasic vasodilatative response, after BD a short mild vasodilatation was followed by a longer vasoconstriction. Endothelium-independent vasodilatation remained unchanged. CONCLUSIONS: BD affects coronary circulation by two means: (1) impairment of CBF to decrease in parallel in afterload with consecutive hemodynamic deterioration and (2) severe endothelial dysfunction that may be a contributing factor to posttransplant outcome.     

Comparison of experimental microvascular end-to-end anastomosis via VCS-Clips versus conventional suture technique in an animal model

In this experimental study on 96 CD rats, microvascular end-to-end anastomoses created via suture or alternatively by means of a VCS-Clip-Application-System, were compared. The aorta abdominalis of the animals, with a diameter of 1.5 +/- 0.2 mm, was experimentally dissected, and the free ends of the vessel then anastomosed. The results were evaluated using sonography, microangiography, histologic examination, and vascular imprints. Postoperative examination was carried out after 1, 3, 7, 14, or 30 days. Major advantages of the VCS-Clip technique over suturing were that it was easy to learn, significantly faster to perform (execution of anastomosis 10.9 +/- 2.6 min versus 19.4 +/- 5.0 min), and produced significantly more favorable histologic results in terms of less inflammatory response, foreign body reaction, necrosis of the tunica media, hyperplasia of the intima, and thrombosis of the vessel lumen. The main disadvantage of the clip technique was a significantly higher rate of stenoses (15.8 +/- 6.0 versus 4.1 +/- 6.6 percent).     

The combination of antagonists of LHRH with antagonists of GHRH improves inhibition of androgen sensitive MDA-PCa-2b and LuCaP-35 prostate cancers

BACKGROUND: Antagonists of growth hormone-releasing hormone (GHRH) could extend the duration of response of androgen sensitive prostate cancers to androgen deprivation. METHODS: We investigated the effect of new GHRH antagonists MZ-J-7-118 and MZ-J-7-138 and luteinizing hormone-releasing hormone (LHRH) antagonist Cetrorelix or castration on androgen sensitive MDA-PCa-2b and LuCaP-35 prostate cancer models xenografted into nude mice. Animals bearing androgen-independent LuCaP-35V prostatic cancer model were also treated with MZ-J-7-118. RESULTS: Receptors for LHRH and GHRH were present in MDA-PCA-2b, LuCaP-35, and LuCaP-35V tumors. GHRH antagonists increased the inhibitory effect of surgical castration and LHRH antagonists on androgen sensitive MDA-PCa-2b and LuCaP-35 tumors. The time to relapse of androgen-dependent LuCaP-35 tumors was extended by GHRH antagonists. Growth of androgen-independent LuCaP-35V xenografts was also significantly inhibited by MZ-J-7-118. In MDA-PCa-2b tumors treatment with MZ-J-7-118 caused a significant decrease of VEGF and Cetrorelix or its combination with MZ-J-7-118 reduced EGF. The B(max) of EGF receptors was significantly reduced by Cetrorelix, MZ-J-7-118 and their combination. CONCLUSIONS: Our findings suggest that the use of a combination of antagonists of GHRH and LHRH could improve the therapy for androgen sensitive prostate cancer. Antagonists of GHRH could be also considered for treatment of androgen-independent prostate cancers.     

'Spindle cell oncocytoma' of the adenohypophysis: a tumor of folliculostellate cells?

We describe five primary tumors of the adenohypophysis featuring mitochondrion-rich spindle cells. The patient ages ranged from 53 to 71 years (mean 61.6 years); two were female. All presented with panhypopituitarism. Two also had visual field defect. On neuroimaging all tumors showed suprasellar extension and were indistinguishable from pituitary adenoma. None showed imaging or operative evidence of dural involvement. All were gross totally removed: four by transsphenoidal surgery and one by frontal craniotomy. Follow-up ranged from 2 to 68 months (mean 35.4 months). No recurrences were noted. The clinical workup was noncontributory in all but two patients: one (case no. 4) with an oncocytic thyroid adenoma and another (case no. 5) with squamous carcinoma of both the uterine cervix and of vocal cord. Histologically, the five tumors were composed mainly of fascicles of spindle cells with eosinophilic, granular cytoplasm. Mitoses were rare and necrosis was absent. Neoplastic cells were immunoreactive for vimentin, epithelial membrane antigen, S-100 protein, and galectin-3. Stains for pituitary hormones, synaptophysin, chromogranin, glial fibrillary acidic protein, cytokeratin CAM5.2, smooth muscle actin, CD34, and CD68 were negative. No thyroglobulin immunoreactivity was noted in the tumor of case no. 4. Ultrastructurally, the neoplastic cells contained numerous mitochondria with lamellar cristae. The neoplastic cells were linked by intermediate junctions and desmosomes. No secretory granules were noted. The histologic, immunohistochemical, and fine structural features of these tumors were unlike those of pituitary adenoma or any other primary sellar tumor. A derivation from adenohypophyseal folliculostellate cells is suggested.     

Open hemiarch versus clamped ascending aorta replacement for aortopathy during initial bicuspid aortic valve replacement

BackgroundThere is controversy regarding the extent of aortic resection necessary in patients with aortopathy related to bicuspid aortic valve disease. To address this issue, we reviewed our experience in patients undergoing ascending aorta replacement during bicuspid aortic valve replacement.MethodsWe reviewed 702 patients who underwent ascending aorta replacement at the time of initial nonemergent native bicuspid aortic valve replacement at our institution between January 2000 and June 2017. Treatment cohorts included an open hemiarch replacement group (n = 225; 32%) and a clamped ascending aorta replacement group (n = 477; 68%).ResultsMedian patient age was 60 years (interquartile range [IQR], 51-67 years), female sex was present in 113 patients (16%), ejection fraction was 62% (IQR, 56%-66%), and aortic arch diameter was 33 mm (IQR, 29-36 mm). Cardiopulmonary bypass time was longer in the hemiarch replacement group (188 minutes vs 97 minutes; P < .001). Procedure-related complications (36%) and mortality (<1%) were similar in the 2 groups; however, the hemiarch group had an increased odds of blood transfusion (odds ratio, 1.62; 95% confidence interval [CI], 1.15-2.28; P = .006). The median duration of follow-up was 6.0 years (95% CI, 5.3-6.8 years). Overall survival was 94 ± 1% at 5 years and 80 ± 2% at 10 years. Multivariable analysis demonstrated similar survival in the 2 groups (hazard ratio, 0.83; 95% CI, 0.51-1.33; P = .439). No repeat aortic arch operations were done for aortopathy over the duration of clinical follow-up.ConclusionsCompared with patients in the clamped ascending aorta replacement group, patients in the hemi-arch replacement group had longer cardiopulmonary bypass and aortic cross-clamp times, along with an increased risk of blood transfusion, but similar freedom from repeat aortic arch operation and survival. We identified no advantage of performing hemiarch replacement in the absence of aortic arch dilation.     

In situ liver transection with portal vein ligation for rapid growth of the future liver remnant in two‐stage liver resection

Background:

Portal vein embolization (PVE) has become a standard procedure to increase the future liver remnant (FLR) and enable curative resection of initially unresectable liver tumours. This study investigated the safety and feasibility of a new two‐stage liver resection technique that uses in situ liver transection (ISLT) and portal vein ligation before completion hepatectomy.

Methods:

A consecutive series of patients undergoing ISLT and extended right hepatectomy between 2009 and 2011 were compared with consecutive patients undergoing extended right hepatectomy after PVE. All patients had initially unresectable primary or secondary liver tumours, owing to an insufficient FLR (liver segments II/III).

Results:

Fifteen patients who had PVE and seven who underwent ISLT before extended right hepatectomy were evaluated. ISLT induced rapid growth of the FLR within 3 days, particularly after insufficient PVE, from a mean(s.d.) of 293(58) ml to 477(85) ml, corresponding to a volume increase of 63(29) per cent. All patients who had ISLT underwent completion extended right hepatectomy within 8 days (range 4–8 days).

Conclusion:

ISLT is an effective and reliable technique to induce rapid growth of the FLR, even in patients with insufficient volume increase after PVE. Copyright © 2012 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.     

Project for Universal Management of Airways – part 1: concept and methods

Multiple professional groups and societies worldwide have produced airway management guidelines. These are typically targeted at the process of tracheal intubation by a particular provider group in a restricted category of patients and reflect practice preferences in a particular geographical region. The existence of multiple distinct guidelines for some (but not other) closely related circumstances, increases complexity and may obscure the underlying principles that are common to all of them. This has the potential to increase cognitive load; promote the grouping of ideas in silos; impair teamwork; and ultimately compromise patient care. Development of a single set of airway management guidelines that can be applied across and beyond these domains may improve implementation; promote standardisation; and facilitate collaboration between airway practitioners from diverse backgrounds. A global multidisciplinary group of both airway operators and assistants was assembled. Over a 3-year period, a review of the existing airway guidelines and multiple reviews of the primary literature were combined with a structured process for determining expert consensus. Any discrepancies between these were analysed and reconciled. Where evidence in the literature was lacking, recommendations were made by expert consensus. Using the above process, a set of evidence-based airway management guidelines was developed in consultation with airway practitioners from a broad spectrum of disciplines and geographical locations. While consistent with the recommendations of the existing English language guidelines, these universal guidelines also incorporate the most recent concepts in airway management as well as statements on areas not widely addressed by the existing guidelines. The recommendations will be published in four parts that respectively address: airway evaluation; airway strategy; airway rescue and communication of airway outcomes. Together, these universal guidelines will provide a single, comprehensive approach to airway management that can be consistently applied by airway practitioners globally, independent of their clinical background or the circumstances in which airway management occurs.     

Isolation and expression of the Pneumocystis carinii dihydrofolate reductase gene.

Pneumocystis carinii dihydrofolate reductase (DHFR; 5,6,7,8-tetrahydrofolate: NADP+ oxidoreductase, EC 1.5.1.3) cDNA sequences have been isolated by their ability to confer trimethoprim resistance to Escherichia coli. Consistent with the recent conclusion that P. carinii is a member of the Fungi, sequence analysis and chromosomal localization show that DHFR is neither physically nor genetically linked to thymidylate synthase. Expression of recombinant P. carinii DHFR in heterologous hosts provides an abundant source of the enzyme that may form a basis for the development of new therapies for this enigmatic pathogen. Studies with the recombinant enzyme show that trimethoprim is a very poor inhibitor of P. carinii DHFR and, in fact, is a more potent inhibitor of human DHFR.