Antimicrobial Activity of Human Leukocyte Defensin HNP-4 Against Gram-negative Bacteria

Human neutrophils (PMN cells) contain four peptides known as alpha (α)-defensins or HNP 1-4. The peptides have broad-spectrum antibiotic activity. HNP 1-3 are major neutrophil components. They differ by only one amino acid residue. HNP-4 is found in small amounts, and has a different sequence. HNP-4 purified from neutrophils was reported to be 100-times more active than HNP-1 against Escherichia coli, suggesting that HNP-4 plays a special role in helping neutrophils kill gram-negative bacteria.Activity of HNP-4 against gram-negative bacteria is of special interest because Aggregatibacter (Actinobacillus) actinomycetemcomitans (A.a.) and other periodontal pathogens are gram-negative. These bacteria are resistant to HNP 1-3. Defensin-resistance may contribute to the ability of these bacteria to cause disease. There have been no studies of HNP-4 activity against oral bacteria, because HNP-4 is found in small amounts and is difficult to purify. Recently, HNP-4 was chemically synthesized, making it possible to study its antibacterial activity. However, synthetic HNP-4 was reported to be no more active than HNP-1 against E. coli.Lipopolysaccharide (LPS) covers the surface of gram-negative bacteria. Each LPS molecule has three parts: a long carbohydrate chain (oligosaccharide) that is exposed on the cell surface, a short carbohydrate core, and lipid A that anchors LPS in the outer membrane. LPS on the bacterial cell surface may be the receptor for HNP-4 and other peptides that kill gram-negative bacteria.Our aims were to: (1) Compare the purity and physical properties of purified and synthetic HNP-4. (2) Compare activity of synthetic and purified HNP-4 against E. coli. (3) Determine whether synthetic HNP-4 binds to purified E. coli LPS. (4) Locate the HNP-4 binding site for synthetic HNP-4 on E. coli LPS molecules. (5) Measure activity of synthetic HNP-4 against A.a. (6) Compare binding of synthetic HNP-4 to LPS purified from E. coli and A.a. Results: (1) Purified and synthetic HNP-4 were of high purity. They had the same molecular mass, which was equal to the mass calculated from the amino acid sequence. (2) Activity of purified and synthetic HNP-4 against E. coli was the same, and similar to the activity of HNP-1. (3) LPS purified from E. coli absorbed synthetic HNP-4. (4) Experiments with LPS fragments showed that synthetic HNP-4 was absorbed to the LPS inner core. (5) Synthetic HNP-4 partially inhibited growth of A.a. but did not kill these bacteria. (6) There was no difference in the ability of E. coli or A.a. LPS to absorb synthetic HNP-4. The results suggest that HNP-4 is not more active than other neutrophil α-defensins against gram-negative bacteria. The results also indicate that LPS on the surface of gram-negative bacteria could be the receptor for HNP-4. Because HNP-4 binds to the LPS inner core, HNP-4 may help neutrophils kill gram-negative bacteria that lack oligosaccharide and the LPS outer core. The periodontal pathogen A.a. is resistant to all of the human leukocyte α-defensins including HNP-4. Therefore, synthetic HNP-4 is not likely to be used in dental practice to prevent or treat oral disease. Resistance of A.a. to HNP-4 is not the result of a difference in LPS structure that interferes with HNP-4 binding. Further studies are needed to determine the mechanism of defensin resistance

Telomeres and Telomerase in Neuroblastoma

Telomeres are nucleoprotein structures located at the ends of linear chromosomes. In most human adult normal somatic cells, telomeres shorten after each cellular division. This shortening ultimately leads to senescence and/or apoptosis. By contrast, in most cancer cells, telomerase activation compensates this loss and confers to these cells their infinite cell proliferation potential. Neuroblastoma (NBL) is a malignant tumor of the peripheral sympathetic nervous system and the most frequent extracranial solid tumor of childhood. NBLs are remarkably heterogeneous both at the levels of biology, genetic and clinical courses. Indeed, some of NBLs can regress spontaneously or after a mild treatment, while others are in the high-risk category with poor prognosis. The molecular bases underlying this heterogeneity are poorly understood. MYCN (V-Myc Avian Myelocytomatosis Viral Oncogene Neuroblastoma-derived Homolog) amplification, recognized as strongly associated with unfavorable patient outcome, is found in only 40% of the high-risk disease, indicating the involvement of other mechanisms. Recent observations suggest that telomerase expression and telomere dysfunctions may be one critical step in NBL development. This review provides recent insights on telomeres/telomerase regulation in NBL. Because of their involvement in the tumor cell biology, telomere and telomerase are currently at the core of new drug development

A Prospective Controlled Study of Magnetic Resonance Imaging of the Brain in Gay Men and Parenteral Drug Users with Human Immunodeficiency Virus Infection

To detect the earliest structural changes in the brain in human immunodeficiency virus (HIV) infection, 118 gay men and 115 parenteral drug users enrolled in a study of the natural history of HIV infection underwent magnetic resonance imaging evaluations. Routine T2-weighted and heavily T2-weighted scans for quantification of brain water were obtained, blinded to HIV serostatus. Atrophy and foci of increased signal did not correlate with any medical, immunologic, neurologic, or neuropsychologic parameters in the group as a whole, or in the gay men or parenteral drug user subgroups. Three subjects had progressive multifocal leukoencephalopathy and one had central nervous system lymphoma. In a subgroup in whom intracranial water percent was calculated, correlations were found with CD4 counts and CD4/CD8 ratios. We conclude that standard magnetic resonance imaging of the brain does not differentiate asymptomatic and mildly symptomatic HIV-positive individuals from HIV-negative individuals, regardless of risk group. However, intracranial water percent may distinguish HIV-positive from HIV-negative individuals because it correlates with raw CD4 counts and CD4/CD8 ratios

The historical development of sewers worldwide

Open Access articleAlthough there is evidence of surface-based storm drainage systems in early Babylonian and Mesopotamian Empires in Iraq (ca. 4000-2500 BC), it is not until after ca. 3000 BC that we find evidence of the well organized and operated sewer and drainage systems of the Minoans and Harappans in Crete and the Indus valley, respectively. The Minoans and Indus valley civilizations originally, and the Hellenes and Romans thereafter, are considered pioneers in developing basic sewerage and drainage technologies, with emphasis on sanitation in the urban environment. The Hellenes and Romans further developed these techniques and greatly increased the scale of these systems. Although other ancient civilizations also contributed, notably some of the Chinese dynasties, very little progress was made during the Dark ages from ca. 300 AD through to the middle of the 18th century. It was only from 1850 onwards that that modern sewerage was "reborn", but many of the principles grasped by the ancients are still in use today. This paper traces the development of the sewer from those earliest of civilizations through to the present day and beyond. A 6000 year technological history is a powerful validation of the vital contribution of sewers to human history. © 2014 by the authors

Long-term myocardial recovery after mitral valve replacement in noncompaction cardiomyopathy

Isolated noncompaction of the left ventricle is a congenital cardiomyopathy, which has been described recently, with literature limited to case reports and case series. Even though various complications have been reported with noncompaction cardiomyopathy, among them severe mitral regurgitation has been reported recently in a few cases. There is no great evidence in the literature about its management, apart from some cases of mitral valve repair and replacement in young patients. We are reporting a case of an elderly lady with isolated left ventricular noncompaction cardiomyopathy associated with severe mitral regurgitation treated with mitral valve replacement with one and half year of follow up demonstrating significant myocardial recovery

Histopathologic predictors of survival and recurrence in resected ampullary adenocarcinoma

Objective: The aim of the study was to define histopathologic characteristics that independently predict overall survival (OS) and disease-free survival (DFS), in patients who underwent resection of an ampullary adenocarcinoma with curative intent. Summary Background Data: A broad range of survival rates have been described for adenocarcinoma of the ampulla of Vater, presumably due to morphological heterogeneity which is a result of the different epitheliums ampullary adenocarcinoma can arise from (intestinal or pancreaticobiliary). Large series with homogenous patient selection are scarce. Methods: A retrospective multicenter cohort analysis of patients who underwent pancreatoduodenectomy for ampullary adenocarcinoma in 9 European tertiary referral centers between February 2006 and December 2017 was performed. Collected data included demographics, histopathologic details, survival, and recurrence. OS and DFS analyses were performed using Kaplan–Meier curves and Cox proportional hazard models. Results: Overall, 887 patients were included, with a mean age of 66 ± 10 years. The median OS was 64 months with 1-, 3-, 5-, and 10-year OS rates of 89%, 63%, 52%, and 37%, respectively. Histopathologic subtype, differentiation grade, lymphovascular invasion, perineural invasion, T-stage, N-stage, resection margin, and adjuvant chemotherapy were correlated with OS and DFS. N-stage (HR = 3.30 [2.09–5.21]), perineural invasion (HR = 1.50 [1.01–2.23]), and adjuvant chemotherapy (HR = 0.69 [0.48–0.97]) were independent predictors of OS in multivariable analysis, whereas DFS was only adversely predicted by N-stage (HR = 2.65 [1.65–4.27]). Conclusions: Independent predictors of OS in resected ampullary cancer were N-stage, perineural invasion, and adjuvant chemotherapy. N-stage was the only predictor of DFS. These findings improve predicting survival and recurrence after resection of ampullary adenocarcinoma

REDISCOVER guidelines for borderline-resectable and locally advanced pancreatic cancer: management algorithm, unanswered questions, and future perspectives

The REDISCOVER guidelines present 34 recommendations for the selection and perioperative care of borderline-resectable (BR-PDAC) and locally advanced ductal adenocarcinoma of the pancreas (LA-PDAC). These guidelines represent a significant shift from previous approaches, prioritizing tumor biology over anatomical features as the primary indication for resection. Condensed herein, they provide a practical management algorithm for clinical practice. However, the guidelines also highlight the need to redefine LA-PDAC to align with modern treatment strategies and to solve some contradictions within the current definition, such as grouping "difficult" and "impossible" to resect tumors together. Furthermore, the REDISCOVER guidelines highlight several areas requiring urgent research. These include the resection of the superior mesenteric artery, the management strategies for patients with LA-PDAC who are fit for surgery but unable to receive multi-agent neoadjuvant chemotherapy, the approach to patients with LA-PDAC who are fit for surgery but demonstrate high serum Ca 19.9 levels even after neoadjuvant treatment, and the optimal timing and number of chemotherapy cycles prior to surgery. Additionally, the role of primary chemoradiotherapy versus chemotherapy alone in LA-PDAC, the timing of surgical resection post-neoadjuvant/primary chemoradiotherapy, the efficacy of ablation therapies, and the management of oligometastasis in patients with LA-PDAC warrant investigation. Given the limited evidence for many issues, refining existing management strategies is imperative. The establishment of the REDISCOVER registry (https://rediscover.unipi.it/) offers promise of a unified research platform to advance understanding and improve the management of BR-PDAC and LA-PDAC

REDISCOVER International Guidelines on the Perioperative Care of Surgical Patients With Borderline-resectable and Locally Advanced Pancreatic Cancer

OBJECTIVE: The REDISCOVER consensus conference aimed at developing and validate guidelines on the perioperative care of patients with borderline resectable (BR-) and locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC).SUMMARY BACKGROUND DATA: Coupled with improvements in chemotherapy and radiation, the contemporary approach to pancreatic surgery supports resection of BR-PDAC and, to a lesser extent, LA-PDAC. Guidelines outlining the selection and perioperative care for these patients are lacking.METHODS: The Scottish Intercollegiate Guidelines Network (SIGN) methodology was used to develop the REDISCOVER guidelines and create recommendations. The Delphi approach was used to reach consensus (agreement ≥80%) among experts. Recommendations were approved after a debate and vote among international experts in pancreatic surgery and pancreatic cancer management. A Validation Committee used the AGREE II-GRS tool to assess the methodological quality of the guidelines. Moreover, an independent multidisciplinary advisory group revised the statements to ensure adherence to non-surgical guidelines.RESULTS: Overall, 34 recommendations were created targeting centralization, training, staging, patient selection for surgery, possibility of surgery in uncommon scenarios, timing of surgery, avoidance of vascular reconstruction, details of vascular resection/reconstruction, arterial divestment, frozen section histology of perivascular tissue, extent of lymphadenectomy, anticoagulation prophylaxis and role of minimally invasive surgery. The level of evidence was however low for 29 of 34 clinical questions. Participants agreed that the most conducive mean to promptly advance our understanding in this field is to establish an international registry addressing this patient population ( https://rediscover.unipi.it/ ).CONCLUSIONS: The REDISCOVER guidelines provide clinical recommendations pertaining to pancreatectomy with vascular resection for patients with BR- and LA-PDAC, and serve as the basis of a new international registry for this patient population.</p

REDISCOVER International Guidelines on the Perioperative Care of Surgical Patients With Borderline-resectable and Locally Advanced Pancreatic Cancer

OBJECTIVE: The REDISCOVER consensus conference aimed at developing and validate guidelines on the perioperative care of patients with borderline resectable (BR-) and locally advanced (LA) pancreatic ductal adenocarcinoma (PDAC).SUMMARY BACKGROUND DATA: Coupled with improvements in chemotherapy and radiation, the contemporary approach to pancreatic surgery supports resection of BR-PDAC and, to a lesser extent, LA-PDAC. Guidelines outlining the selection and perioperative care for these patients are lacking.METHODS: The Scottish Intercollegiate Guidelines Network (SIGN) methodology was used to develop the REDISCOVER guidelines and create recommendations. The Delphi approach was used to reach consensus (agreement ≥80%) among experts. Recommendations were approved after a debate and vote among international experts in pancreatic surgery and pancreatic cancer management. A Validation Committee used the AGREE II-GRS tool to assess the methodological quality of the guidelines. Moreover, an independent multidisciplinary advisory group revised the statements to ensure adherence to non-surgical guidelines.RESULTS: Overall, 34 recommendations were created targeting centralization, training, staging, patient selection for surgery, possibility of surgery in uncommon scenarios, timing of surgery, avoidance of vascular reconstruction, details of vascular resection/reconstruction, arterial divestment, frozen section histology of perivascular tissue, extent of lymphadenectomy, anticoagulation prophylaxis and role of minimally invasive surgery. The level of evidence was however low for 29 of 34 clinical questions. Participants agreed that the most conducive mean to promptly advance our understanding in this field is to establish an international registry addressing this patient population ( https://rediscover.unipi.it/ ).CONCLUSIONS: The REDISCOVER guidelines provide clinical recommendations pertaining to pancreatectomy with vascular resection for patients with BR- and LA-PDAC, and serve as the basis of a new international registry for this patient population.</p