New Phage-Derived Antibacterial Enzyme PolaR Targeting Rothia spp

Rothia is an opportunistic pathogen, particularly life-threatening for the immunocompromised. It is associated with pneumonia, endocarditis, peritonitis and many other serious infections, including septicemia. Of note, Rothia mucilaginousa produces metabolites that support and increase overgrowth of Pseudomonas aeruginosa, one of the ESKAPE bacteria. Endolysins are considered as antibacterial enzymes derived from bacteriophages that selectively and efficiently kill susceptible bacteria without harming human cells or the normal microbiome. Here, we applied a computational analysis of metagenomic sequencing data of the gastric mucosa phageome extracted from human patients' stomach biopsies. A selected candidate anti-Rothia sequence was produced in an expression system, purified and confirmed as a Rothia mucilaginosa- and Rothia dentocariosa-specific endolysin PolaR, able to destroy bacterial cells even when aggregated, as in a biofilm. PolaR had no cytotoxic or antiproliferative effects on mammalian cells. PolaR is the first described endolysin selectively targeting Rothia species, with a high potential to combat infections caused by Rothia mucilaginosa and Rothia dentocariosa, and possibly other bacterial groups. PolaR is the first antibacterial enzyme selected from the gastric mucosa phageome, which underlines the biological complexity and probably underestimated biological role of the phageome in the human gastric mucosa.

Antibodies specific to SARS-CoV-2 proteins N, S and E in COVID-19 patients in the normal population and in historical samples

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally; recognition of immune responses to this virus will be crucial for coronavirus disease 2019 (COVID-19) control, prevention and treatment. We comprehensively analysed IgG and IgA antibody responses to the SARS-CoV-2 nucleocapsid protein (N), spike protein domain 1 (S1) and envelope protein (E) in: SARS-CoV-2-infected patient, healthy, historical and pre-epidemic samples, including patients' medical, epidemiological and diagnostic data, virus-neutralizing capability and kinetics. N-specific IgG and IgA are the most reliable diagnostic targets for infection. Serum IgG levels correlate to IgA levels. Half a year after infection, anti-N and anti-S1 IgG decreased, but sera preserved virus-inhibitory potency; thus, testing for IgG may underestimate the protective potential of antibodies. Historical and pre-epidemic sera did not inhibit SARS-CoV-2, thus its circulation before the pandemic and a protective role from antibodies pre-induced by other coronaviruses cannot be confirmed by this study.

The Role of Serum Calprotectin as a New Marker in Abdominal Aortic Aneurysms - A Preliminary Report

BACKGROUND

Abdominal Aortic Aneurysm (AAA) remains a surgical challenge. There are many recognizable markers associated with the formation of AAA. Previous experiments carried out on animal models have shown a correlation between serum calprotectin and the occurrence of AAA.

OBJECTIVE

This study aimed to evaluate the level of calprotectin as a potential diagnostic biomarker in patients with diagnosed AAA.

METHODS

The study group consisted of 75 patients aged 35-75 years assigned to two groups: a control group (n=43) of healthy subjects without AAA and a study group (n=32) of patients with a diagnosed AAA. The first calprotectin test was performed upon patient admission to the hospital, and the second control test was performed after three months. The concentration of calprotectin in plasma was determined using the Immunoenzymatic Method (ELISA) with the commercially available Assaypro Kit (AssayMax™ Human Calprotectin ELISA Kit), as well as the sandwich method with polyclonal antibodies to human calprotectin and peroxidase enzyme.

RESULTS & DISCUSSION

Serum calprotectin levels in AAA patients were three times higher than in healthy subjects (p<0.05). A statistically significant twofold decrease in calprotectin concentration was observed after AAA surgery compared to the control group (p<0.05).

CONCLUSION

Calprotectin levels can be an important marker in the detection of AAA. In conclusion, AAA patients showed a threefold increase in serum calprotectin level and a twofold decrease in this marker after AAA surgery.

Application of 16S rRNA gene sequencing in Helicobacter pylori detection

Helicobacter pylori is one of the major stomach microbiome components, promoting development of inflammation and gastric cancer in humans. H. pylori has a unique ability to transform into a coccoidal form which is difficult to detect by many diagnostic methods, such as urease activity detection, and even histopathological examination. Here we present a comparison of three methods for H. pylori identification: histological assessment (with eosin, hematoxylin, and Giemsa staining), polymerase chain reaction (PCR) detection of urease (ureA specific primers), and detection by 16S rRNA gene sequencing. The study employed biopsies from the antral part of the stomach (N = 40). All samples were assessed histologically which revealed H. pylori in eight patients. Bacterial DNA isolated from the bioptates was used as a template for PCR reaction and 16S rRNA gene sequencing that revealed H. pylori in 13 and in 20 patients, respectively. Thus, 16S rRNA gene sequencing was the most sensitive method for detection of H. pylori in stomach biopsy samples.

High antibiotic resistance of Helicobacter pylori and its effect on tailored and empiric eradication of the organism in Lower Silesia, Poland

BACKGROUND

At present, the resistance to antibiotics is considered the most important reason for Helicobacter pylori (HP) eradication failure. The aim of this study was to estimate the prevalence of antimicrobial resistance of HP strains and to evaluate tailored and empiric therapeutic regimens in patients with peptic ulcer disease associated with infection of this microorganism.

MATERIALS AND METHODS

Between May 2011 and February 2013, 185 consecutive Polish patients with at least one positive Helicobacter pylori test (urease test, histopathologic examination, and/or culture) underwent eradication therapy. Those with positive culture were prescribed a tailored triple regimen, whereas those with no culture available received an empiric quadruple concomitant regimen or levofloxacin-containing triple therapy.

RESULTS

There were no HP strains resistant to amoxicillin; however, 56.7% were resistant to metronidazole, 55.2% to clarithromycin, and 5.9% to levofloxacin. Dual resistance was detected in 32.8% of individuals. Tailored and empiric therapies achieve cure rates, respectively, 95.5% and 86.6% by intention-to-treat and 95.5% and 91.3% by per-protocol analysis (P > 0.05).

CONCLUSIONS

Antibiotic resistance is notably high in Poland currently, but both tailored and empiric therapies can achieve acceptable cure rates equal to or higher than 90%.

Secondary Aortoenteric Fistula After Abdominal Aortic Graft Implementation in Our Own Material

BACKGROUND

Secondary aortoenteric fistula is a rare but severe complication occurring after abdominal aortic graft implementation.

OBJECTIVES

The aim of our study was to review the clinical presentation, diagnosis and postoperative course of patients with aortoenteric fistulas following vascular operations on the abdominal aorta in the years 2000-2014.

MATERIAL AND METHODS

Among all the patients treated in our center, during a 10-year period, aortoenteric fistulas were observed in 24 cases. The first symptoms occurred between 4 weeks and 8 years after the procedure (3.4 years on average). The most common clinical presentation was gastrointestinal bleeding in 16 cases (66.7%). All patients underwent surgical repair of an aortoenteric fistula, with graft removal and replacement in situ using silver impregnated prosthesis.

RESULTS

The 30-day mortality rate after surgical treatment of SAEF was 37.5% (9 patients). Causes of death included: hemorrhagic shock, multi-organ failure and myocardial infarction. The early complications after the surgical repair of an aortoenteric fistula occurred in 19 (79.2%) patients. Mortality during the one-year follow-up period was 38.5% (5 patients) and the one-year complication rate was 69.2%.

CONCLUSIONS

Each patient with a history of abdominal aortic graft implementation and presenting symptoms of gastrointestinal bleeding requires careful diagnosing for aortoenteric fistula. New methods of surgical treatment offering lower mortality should be developed.

Comparison of Endovascular Aneurysm Repair with Open Repair in Patients with Abdominal Aortic Aneurysm in Our Own Material in Years 2002-2011

BACKGROUND

Endovascular abdominal aortic aneurysm repair has become an alternative to open surgical repair of abdominal aortic aneurysm since the early 1990s. The conventional method remains the gold standard in the treatment of Abdominal Aortic Aneurysm (AAA); however, a large percentage of patients do not qualify for this treatment due to the high risk of perioperational death and complications.

OBJECTIVES

The objective of this work was to compare AAA surgeries performed by both classical and endovascular methods in years 2002-2011.

MATERIAL AND METHODS

Medical documentation of elective AAA patients undergoing surgical treatment was retrospectively analyzed on the basis of archive- and computer database data. The analysis included the patients' demographics, internal disease burden, as well as causes of deaths and complications within 30 days after the procedure and 1 year follow-up.

RESULTS

Thirty-day and 1-year mortality rates in patients treated in the elective setting were 1.5% and 8.7% for endovascular method and 4.0% and 15.7% for the open method. The comparison of mortality rates in 115 high-risk patients undergoing elective OR treatment with 275 high-risk treatment patients undergoing EVAR surgery (7.8% vs. 1.5%, 8.7% vs. 15.7%, p<.01) showed that the endovascular method significantly reduced the mortality in the latter group.

CONCLUSIONS

Endovascular treatment is an attractive option in AAA; especially in heavily burdened patients, because it definitely reduces mortality. EVAR was found to be advantageous over OR in case of high-risk patients.

Nonspecific effects of ligands on the beta-adrenergic receptors in rabbit abdominal aorta in vitro

The study was conducted on 30 New Zealand rabbits weighing 3-4 kg from which sample strips of the abdominal aorta were collected. The study investigated the in vitro reaction of rabbit aorta smooth muscle to ligands binding to beta-adrenergic receptors. The response of aortic strips to beta-adrenergic receptor agonists (dobutamine, isoproterenol, salbutamol) and the influence of beta-adrenergic receptor antagonists (propranolol, betaxolol) on contractile activity was determined. All tested agonists induced contraction of the rabbit abdominal aorta muscle in a concentration-dependent manner (dobutamine >> isoproterenol > salbutamol). Enhanced reaction to low concentrations of agonists (dobutamine, isoproterenol) after administration of propranolol and inhibition of contractility in the presence of high concentrations thereof (dobutamine, salbutamol) was observed. Maximal reaction to agonists decreased after betaxolol pretreatment. The results indicate that all the substances with beta-agonist activity also possess contracting properties (presumably by acting at alpha-adrenergic receptors), but are much weaker in the case of isoproterenol and salbutamol than for dobutamine. Propranolol and betaxolol reduce the contractile response of smooth muscle using probably other mechanisms than those associated with adrenergic receptors.

[Minimally invasive access to the abdominal aorta in pigs]

Experiments were conducted on 10 sows weighing 50-60 kg. Animals were randomly divided into two experimental groups comprising 5 individuals each. Surgical procedure of reaching the abdominal aorta below the renal arteries was performed using two different methods. In animals from the first group the procedure involved cutting the linea alba in order to obtain access to the abdominal aorta through the abdominal cavity. In the second group the access to the abdominal aorta was obtained by retroperitoneal approach. The approach was made in lower lateral one-third of the abdomen cutting through the muscles and without opening the peritoneal cavity. The study showed superiority of the second surgical method over the median approach along the linea alba in the form of: better animal survival (100% of animals), shorter procedure time, lack of postoperative complications, shorter recovery period and better general postoperative condition

[Effect of atherosclerotic plaque on the contractility of human abdominal aorta sections]

The study was performed on 18 sections of the aneurysm-like abdominal aorta sampled during elective procedures of aneurysm correction in humans, and 10 sections of pig abdominal aorta. We examined the extent to which the presence of atherosclerotic plaque impaired the aorta contractile function and measured the thickness and weight of atherosclerosis plaque and arterial wall. We observed reduced tissue response to adrenaline in human aneurysm-like aorta in comparison to the control group. In the sections of human aorta devoid of atherosclerotic plaque the response to adrenaline was about 30% higher than in those with atherosclerotic changes but 35% lower than in normal aorta sections from pigs. The wall of aneurysm-like human aorta sections was thinner when compared to normal aorta.

Aortoesophageal fistula as a complication of thoracic aorta aneurism stent grafting - a case report and literature review

Background:

Endovascular stent grafting is performed in patients with aneurysms of aorta or other major vessels. The procedure is considered to be generally safe, with a low risk of complications, the most common of which include endoleaks, stenosis or thrombosis at the stagraft and itsmigration.

Very rare complications include aortoesophageal and aortobronchial fistulas (0.5–1.7% cases).

Case Report:

A 64-year-old patient was admitted to our hospital with suspected aortoesophageal fistula. Two years prior, the patient had undergone a stent graft repair of the thoracic aorta at the local vascular surgery clinic. Both laboratory results and CT angiography revealed aortoesophageal fistula, which was also detected in endoscopic examination.

Despite intensive treatment and preparation for surgery, the patient died 6 days after admission.

Conclusions:

Aortoesophageal and aortobronchial fistulas are among the most dangerous and difficult-to-treat complications in the treatment of thoracic aortic aneurysms by endovascular stent-grafting. This clearly indicates that preventive care and regular medical examinations are important to prevent their occurrence.

In vitro contractility of normal and aneurysmal abdominal aorta muscle coat sections in human and animal material

The objective of the study was to demonstrate spontaneous contractile activity of the smooth muscle coat of the aorta in human and animal material. Spontaneous contractility of smooth muscle tissue, or tonus, is essential for the proper function of many internal organs as observed in the many types of muscle cells which make up the internal structures. The spontaneous contractile activity of the muscle tissue in blood vessels is particularly marked in resistance vessels, regulating circulation within organs or tissues. It can also be observed in large blood vessels such as arteries and veins. The contractile activity of muscular tissue isolated from arteries is the result of a number of factors, including endogenous paracrine substances, neurotransmitters released at postganglionic endings (mostly within the sympathetic system), cells capable of spontaneously generation of functional potentials (pacemaking cells) and the vascular endothelium. Pacemaking cells present in the aortic wall are an important factor in the development of the spontaneous contractility of the muscular coat of the aorta. They are capable of generating functional potentials, resulting in the constant tonus of the smooth muscular coat (comprising the aortic wall) due to tonic contraction. In vitro studies were carried out on abdominal aortic sections collected from 30 New Zealand rabbits with a body mass of 3-4 kilograms each and also on aneurysmal abdominal aortic sections collected during elective aneurysm repair procedures in humans (10 abdominal aortic sections). The 1.5 cm-long sections were mounted in chambers of an automated water bath. The sections were oriented in a transverse and longitudal fashion in order to compare contractility. The incubation medium consisted of Krebs-Henseleit buffer. Spontaneous contractile activity was observed during the study, characterized by rhythmic contractions of the muscular layer of the aorta. The contractile tension within the sections was 0.15 mN in the case of rabbit sections and 0.8 mN in the case of human sections. The average duration of a single contraction was 38.3 +/- 15.05 seconds. The average contraction frequency, i.e. the average number of contractions per minute, was 1.61 +/- 0.54 contractions per minute. The spontaneous contraction is modulated by many factors like endogenous paracrine substances, neurotransmitters or vascular endothelium.

In vitro study on the effects of some selected agonists and antagonists of alpha(1)-adrenergic receptors on the contractility of the aneurysmally-changed aortic smooth muscle in humans

The study included 18 sections of the aneurysmally-changed abdominal aortas, obtained from patients of the Provincial Specialist Hospital in Wroclaw and 18 sections of normal abdominal aortas obtained from swine. The collected samples were placed horizontally in the incubation chamber. Changes in their transverse section area were registered. They were stretched to a tension of 5 mN. Krebs-Henseleit buffer was used as the incubatory environment. Incubation of the sections was performed at a temperature of 37°C, in the gaseous mixture of oxygen and carbon dioxide used in the following proportion: 95% of O(2) and 5% of CO(2). Contractions of the aorta were registered with isotonic transducers (Letica Scientific Instruments). In the studies, we examined the influence of α(1)-adrenergic receptors (and their subtypes α(1A), α(1B), α(1D)) on the contractility of the aortic muscle in humans and swine by their stimulation or inhibition with some selected agonists or antagonists. This time, it was shown that the stimulation of α(1)-adrenergic receptors leads to contractions of the human and swine aortic muscle; the observed increase in the muscle tone may follow from the stimulation of all subtypes of alpha-1 receptor (α(1A), α(1B), α(1D)). All three subtypes of 1-adrenergic receptor are engaged in vasoconstriction, especially of α(1A) and α(1D) subtypes; the α(1B) subtype is less significant for aortic contractility. The contractile response of the aneurysmally-changed abdominal aorta in humans to agonists of α-adrenergic receptors was significantly less intense than that of the normal porcine aorta. It can be concluded that aneurysms influence the contractile response of the aorta.

Methods to identify and characterize developmental neurotoxicity for human health risk assessment. II: neuropathology

Neuropathologic assessment of chemically induced developmental alterations in the nervous system for regulatory purposes is a multifactorial, complex process. This calls for careful qualitative and quantitative morphologic study of numerous brains at several developmental stages in rats. Quantitative evaluation may include such basic methods as determination of brain weight and dimensions as well as the progressively more complex approaches of linear, areal, or stereologic measurement of brain sections. Histologic evaluation employs routine stains (such as hematoxylin and eosin), which can be complemented by a variety of special and immunohistochemical procedures. These brain studies are augmented by morphologic assessment of selected peripheral nervous system structures. Studies of this nature require a high level of technical skill as well as special training on the part of the pathologist. The pathologist should have knowledge of normal microscopic neuroanatomy/neuronal circuitry and an understanding of basic principles of developmental neurobiology, such as familiarity with the patterns of physiologic or programmed cell de

[Usefulness of transdermal hormone substitution in high risk postmenopausal patients]

The authors studied whether hormone replacement therapy can be performed in postmenopausal patients with high risk factors among anamnestic data such as thromboembolia, diabetes mellitus, hypertension, epilepsy. 50 mg 17 beta estradiol patch (twice weekly) and 10 mg medroxyprogesteron (in the last 12 days of the cycle) were prescribed. Data of 102 patients with the above conditions were analyzed at the beginning and at the 3,6, and 12 month follow-up visits. The frequency of exacerbation of anamnestic disease, biased and unbiased complaints, efficacy and side effects of the therapy were studied. In the authors opinion hormone replacement therapy can be safely performed in patients with high risk factors among anamnestic data, in addition it may be useful to prevent them.

[Effect of dextran of 250.000 molecular weight on experimental cholesterin-sclerosis in rabbits]

Effect of dextran of 250000 molecular weight on experimental cholesterin-sclerosis of rabbits was studied. Doses of 120 (mg/week) kg and 1200 (mg/week) kg administered during 12 weeks have resulted a protective effect. When doses of 1200 (mg/week) kg have been administered--in the aortic adventitia intensive cellular reaction, no hitherto described was revealed, which was considered to be a sing of the exhaustion of RES. This publication authors regard as a preliminary one. To clear whether the cellular reaction observed is a dextran-specific or macro-moleculespecific one further investigations are needed.