Transanal total mesorectal excision (TaTME) in rectal cancer treatment within an expert center

The objective of this study was to evaluate treatment outcomes in patients who underwent the TaTME procedure for cancer of the middle and low rectum in an expert center. Prospective analysis of the outcomes of all consecutive patients treated using the TaTME technique for cancer of the middle and distal rectum at the our medical center between March 1, 2015, and March 31, 2022. A total of 128 patients (34 women, 94 men; mean age 66.01 [38-85] years) with cancer of the middle and distal rectum qualified for TaTME. TaTME procedures were performed in 127/128 (99.22%) patients. Complications of surgery were observed in 22/127 (17.32%) patients. Negative proximal and distal margins were confirmed in all 127 patients. Complete (R0) resection of the mesorectum was confirmed in 125/127 (98.43%) and nearly complete (R1) resection was confirmed in 2/127 (1.57%) patients. The average follow-up period was 795 days (296-1522) days. Local recurrence was detected during the follow-up period in 2/127 (1.57%) patients. This study showed that the TaTME procedure is an effective and safe method for the minimally invasive treatment of middle and low rectal cancers, particularly within an expert center setting.

The analysis of factors increasing the odds for type 2 diabetes mellitus remission following re-do bariatric surgery after laparoscopic sleeve gastrectomy- cohort study

INTRODUCTION

Metabolic/bariatric surgery is the only proven treatment for type 2 diabetes mellitus (T2D) with curative intent. However, in a number of patients, the surgery is not effective or they may experience a relapse. Those patients can be offered re-do bariatric surgery (RBS).

PURPOSE

The study aimed to determine factors increasing the odds for T2D remission one year after RBS following primary laparoscopic sleeve gastrectomy.

METHODS

A multicenter retrospective cohort study was conducted between January 2010 and January 2020, which included 12 bariatric centers in Poland. The study population was divided into groups: Group 1- patients with T2D remission after RBS (n = 28) and Group 2- patients without T2D remission after RBS (n = 49). T2D remission was defined as HBA1c < 6.0% without glucose-lowering pharmacotherapy and glycemia within normal range at time of follow-up that was completed 12 months after RBS.

RESULTS

Fifty seven females and 20 males were included in the study. Patients who achieved BMI < 33 kg/m2 after RBS and those with %EBMIL > 60.7% had an increased chance of T2D remission (OR = 3.39, 95%CI = 1.28-8.95, p = 0.014 and OR = 12.48, 95%CI 2.67-58.42, p = 0.001, respectively). Time interval between primary LSG and RBS was significantly shorter in Group 1 than in Group 2 [1 (1-4) vs. 3 (2-4) years, p = 0.023].

CONCLUSIONS

Shorter time interval between LSG and RBS may ease remission of T2D in case of lack of remission after primary procedure. Significant excess weight loss seems to be the most crucial factor for T2D remission.

The Association of Polish Surgeons (APS) clinical guidelines for the use of laparoscopy in the management of abdominal emergencies. Part II

Introduction

Over the past three decades, almost every type of abdominal surgery has been performed and refined using the laparoscopic technique. Surgeons are applying it for more procedures, which not so long ago were performed only in the classical way. The position of laparoscopic surgery is therefore well established, and in many operations it is currently the recommended and dominant method.

Aim

The aim of the preparation of these guidelines was to concisely summarize the current knowledge on laparoscopy in acute abdominal diseases for the purposes of the continuous training of surgeons and to create a reference for opinions.

Material and methods

The development of these recommendations is based on a review of the available literature from the PubMed, Medline, EMBASE and Cochrane Library databases from 1985 to 2022, with particular emphasis on systematic reviews and clinical recommendations of recognized scientific societies. The recommendations were formulated in a directive form and evaluated by a group of experts using the Delphi method.

Results and conclusions

There are 63 recommendations divided into 12 sections: diagnostic laparoscopy, perforated ulcer, acute pancreatitis, incarcerated hernia, acute cholecystitis, acute appendicitis, acute mesenteric ischemia, abdominal trauma, bowel obstruction, diverticulitis, laparoscopy in pregnancy, and postoperative complications requiring emergency surgery. Each recommendation was supported by scientific evidence and supplemented with expert comments. The guidelines were created on the initiative of the Videosurgery Chapter of the Association of Polish Surgeons and are recommended by the national consultant in the field of general surgery. The second part of the guidelines covers sections 6 to12 and the following challenges for surgical practice: acute appendicitis, acute mesenteric ischemia, abdominal injuries, bowel obstruction, diverticulitis, laparoscopy in pregnancy and postoperative complications requiring a reoperation.

Screening for volatile biomarkers of colorectal cancer by analyzing breath and fecal samples using thermal desorption combined with GC-MS (TD-GC-MS)

Breath and fecal volatile organic compounds (VOCs), among others, represent a new and encouraging clinical practice for the differential diagnosis of colorectal cancer (CRC). The purpose of our research was to identify VOCs present in exhaled air and feces of 20 healthy volunteers (HV) and 15 CRC patients. For collection of gas phase released from feces, emission microchambers were applied. Sorption tubes were used to enrich analytes for both breath and fecal samples. Thermal desorption (TD) technique combined with gas chromatography coupled with mass spectrometry was used at the separation and identification step. The combination of statistical methods was used to evaluate the ability of VOCs to classify control group and CRC patients. Heptanoic acid, acetone, 2,6,10-trimethyldodecane, n-hexane, skatole, and dimethyl trisulfide are observed in elevated amounts in the patients group. The performance of diagnostic models on the tested data set was above 90%. This study is the first attempt to document the using of TD-GC-MS to analyze both breath and fecal samples to search for volatile biomarkers of CRC. A full evaluation of the results described herein requires further studies involving a larger number of samples. Moreover, it is particularly important to understand the metabolic pathways of substances postulated as tumor biomarkers.

Targeted therapies for glioblastoma treatment

Glioblastoma, the most common and aggressive type of brain tumor in adults, poses significant challenges in terms of treatment. Conventional approaches including surgery, chemotherapy, and radiotherapy have yielded limited success, with a median survival of approximately 15 months. However, extensive research into the biology of glioblastoma has identified molecular targets that can be exploited by newly developed drugs, leading to the emergence of precise personalized therapies. Several innovative treatment strategies are currently under development, aiming to enhance effectiveness while minimizing side effects. Clinical trials are underway to evaluate the efficacy of monoclonal antibodies that target glioblastoma cells, either by blocking specific receptors or by modifying molecular interactions that impede cell proliferation. Another promising avenue involves the use of oncolytic viruses designed to selectively infect glioblastoma cells. Additionally, the review explores the utilization of nanocarriers capable of surmounting the formidable obstacle of the blood-brain barrier, enabling efficient drug delivery. Cell therapies represent another promising approach, with dendritic cells, chimeric antigen receptor-T cells, and macrophages emerging as potential treatment modalities. By summarizing recent advances in targeted therapies against glioblastoma, this review aims to provide a comprehensive overview of ongoing efforts to discover effective and safe methods for treating glioblastoma patients. The ultimate goal is to improve patient outcomes and transform the landscape of glioblastoma treatment.

The Association of Polish Surgeons (APS) clinical guidelines for the use of laparoscopy in the management of abdominal emergencies. Part I

Introduction

Over the past three decades, almost every type of abdominal surgery has been performed and refined using the laparoscopic technique. Surgeons are applying it for more procedures, which not so long ago were performed only in the classical way. The position of laparoscopic surgery is therefore well established, and in many operations it is currently the recommended and dominant method.

Aim

The aim of the preparation of these guidelines was to concisely summarize the current knowledge on laparoscopy in acute abdominal diseases for the purposes of the continuous training of surgeons and to create a reference for opinions.

Material and methods

The development of these recommendations is based on a review of the available literature from the PubMed, Medline, EMBASE and Cochrane Library databases from 1985 to 2022, with particular emphasis on systematic reviews and clinical recommendations of recognized scientific societies. Recommendations were formulated in a directive form and evaluated by a group of experts using the Delphi method.

Results and conclusions

There are 63 recommendations divided into 12 sections: diagnostic laparoscopy, perforated ulcer, acute pancreatitis, incarcerated hernia, acute cholecystitis, acute appendicitis, acute mesenteric ischemia, abdominal trauma, bowel obstruction, diverticulitis, laparoscopy in pregnancy, and postoperative complications requiring emergency surgery. Each recommendation was supported by scientific evidence and supplemented with expert comments. The guidelines were created on the initiative of the Videosurgery Chapter of the Association of Polish Surgeons and are recommended by the national consultant in the field of general surgery. The first part of the guidelines covers 5 sections and the following challenges for surgical practice: diagnostic laparoscopy, perforated ulcer, acute pancreatitis, incarcerated hernia and acute cholecystitis. Contraindications for laparoscopy and the ERAS program are discussed.

Analysis of the risk factors for perioperative morbidity after laparoscopic revisional bariatric procedures: results from the multicenter Polish Revision Obesity Surgery Study

BACKGROUND

The growing number of primary bariatric operations has led to an increase in demand for revision surgeries. Higher numbers of revisional operations are also observed in Poland, yet their safety and efficacy remain controversial because of a lack of current recommendations and guidelines.

OBJECTIVE

To review risk factors influencing perioperative morbidity.

METHODS

A retrospective study was conducted to analyze the results of surgical treatment among 12 Polish bariatric centers. Inclusion criteria were laparoscopic revisional bariatric surgeries and patients ≥18 years of age. The study included 795 patients, of whom 621 were female; the mean age was 47 years (range: 40-55 years).

RESULTS

Perioperative morbidity occurred in 92 patients (11.6%) enrolled in the study, including 76 women (82.6%). The median age was 45 years (range: 39-54 years). Statistically significant risk factors in univariate logistic regression models for perioperative complications were the duration of obesity, revisional surgery after Roux-en-Y gastric bypass (RYGB) or adjustable gastric band (AGB), difference in body mass index before revisional surgery and the lowest achieved after primary surgery, and postoperative morbidity of the primary surgery as the cause for revisional bariatric surgery. These factors were included in the multivariate regression model. Revisional surgery after AGB (odds ratio [OR] = 2.18; 95% confidence interval [CI]: 1.28-3.69; P = .004), revisional surgery performed after RYGB (OR = 6.52; 95% CI: 1.98-21.49; P = .002), and revisions due to complication of the primary surgery (OR = 1.89; 95% CI: 1.06-3.34; P = .030) remained independent risk factors for perioperative morbidity.

CONCLUSION

Revisional operations after RYGB or AGB and those performed because of postoperative morbidity after primary surgery as the main cause for revisional surgery were associated with a significantly increased risk of postoperative morbidity.

The impact of severe postoperative complications on outcomes of bariatric surgery-multicenter case-matched study

BACKGROUND

Bariatric surgery has relatively low complication rates, especially severe postoperative complications (defined by Clavien-Dindo classification as types 3 and 4), but these rates cannot be ignored. In other than bariatric surgical disciplines, complications affect not only short-term but also long-term results. In the field of bariatric surgery, this topic has not been extensively studied.

OBJECTIVES

The aim of the study was to assess the outcomes of bariatric treatment in patients with obesity and severe postoperative complications in comparison to patients with a noneventful perioperative course.

SETTING

Six surgical units at Polish public hospitals.

METHODS

We performed a multicenter propensity score matched analysis of 206 patients from 6 Polish surgical units and assessed the outcomes of bariatric procedures. A total of 103 patients with severe postoperative complications (70 laparoscopic sleeve gastrectomy [SG] and 33 with laparoscopic Roux en Y gastric bypass [RYGB]) were compared to 103 patients with no severe complications in terms of peri- and postoperative outcomes.

RESULTS

The outcomes of bariatric treatment did not differ between compared groups. Median percentage of total weight loss 12 months after the surgery was 28.8% in the group with complications and 27.9% in patients with no severe complications (P = 0.993). Remission rates of both type 2 diabetes mellitus and arterial hypertension showed no significant difference between SG and RYGB (36% versus 42%, P = 0.927, and 41% versus 46%, P = 0.575. respectively).

CONCLUSIONS

The study suggests that severe postoperative complications had no significant influence either on weight loss effects or obesity-related diseases remission.

Utility of Inflammatory Markers in Detection of Perioperative Morbidity After Laparoscopic Sleeve Gastrectomy, Laparoscopic Roux-en-Y Gastric Bypass, and One-Anastomosis Gastric Bypass-Multicenter Study

Background

The most commonly performed bariatric operations are laparoscopic sleeve gastrectomy (LSG) and bypass surgeries (laparoscopic one-anastomosis gastric bypass (OAGB) and laparoscopic Roux-en-Y gastric bypass (LRYGB)), and predicting perioperative morbidity is crucial for early, safe patient discharge. We aimed to determine whether C-reactive protein (CRP) and white blood count (WBC) measured on the first postoperative day predicts perioperative morbidity in the first 30-days after LSG and bypass surgeries.

Methods

We retrospectively analyzed data for 1400 patients who underwent bariatric surgery in seven bariatric centers from 2014 to 2018. Patients were divided into a complicated group (patients with postoperative complications) and a non-complicated group. We also performed separate analyses for LSG and bypass surgeries.

Results

Patients were 929 women (66%) and 471 men (34%) with a median age of 42 years (range, 35–51 years); 1192 patients underwent LSG (85%), 120 underwent LRYGB (9%), and 80 underwent OAGB (6%). We performed ROC analyses to set cut-off points, followed by multivariate logistic regressions. CRP > 33.32 mg/L increased the odds ratio (OR) of perioperative complications after LSG 2.27 times, while WBC > 12.15 × 10³/μL on postoperative day 1 was associated with a 3.34-times greater or of developing complications. WBC > 13.78 × 10³/μL was associated with a 13.34-times higher or of perioperative morbidity in patients undergoing bypass surgeries.

Conclusion

Even slightly elevated CRP and WBC on postoperative day 1 should alert surgeons to the potential risk of perioperative morbidity.

When to resume bariatric surgery after COVID-19 pandemic?: results of patients' and surgeons' survey

BACKGROUND

Coronavirus Disease 2019 is affecting most countries around the world, including Poland. In response, all elective surgeries have been postponed. We asked patients and surgeons when they want bariatric surgery to resume after pandemic. The main aim of the study was to determine patients' and surgeons' expectations about when to resume bariatric surgery regarding COVID-19 pandemic state.

METHODS

The study was conducted in two groups: Group 1-bariatric patients; Group 2-bariatric surgeons. Two online surveys were distributed.

RESULTS

A total of 895 patients, 299 before, 596 after surgery and 32 surgeons took part in survey. All patients and surgeons declared willingness to resume bariatric surgeries after pandemic and responded that they should be resumed immediately the World Health Organization announces end of pandemic (42%). The majority of patients before surgery answered that bariatric procedures should be resumed immediately the number of daily incidents begins to decrease (53%). In the patient group, current body mass index (p < 0.001) and contact with COVID+/quarantined persons (p < 0.001) had impact on the response to resumption of bariatric procedures.

CONCLUSIONS

Patients opted to wait for bariatric surgery until the oncological queue has become shorter. Surgeons presented a readiness to resume both procedures in parallel.

Surgical care in Poland after COVID-19 outbreak: a national survey

B a c k g r o u n d: During COVID-19 pandemic, it is necessary to collect and analyze data concerning management of hospitals and wards to work out solutions for potential future crisis. The objective of the study was to investigate how surgical wards in Poland are managing during rapid development of the COVID-19 pandemic. M e t h o d s: An anonymous, online survey was designed and distributed to surgeons and surgery residents working in surgical departments during pandemic. Responders were divided into two groups: Group 1 (responders working in a "COVID-19-dedicated" hospital) and Group 2 (responders working in other hospitals). Results: Overall, 323 responders were included in the study group, 30.03% of which were female. Medical staff deficits were reported by 21.15% responders from Group 1 and 29.52% responders from Group 2 (p = 0.003). The mean number of elective surgeries performed weekly prior to the pandemic in Group 1 was 40.37 ± 46.31 and during the pandemic was 13.98 ± 37.49 (p < 0.001). In Group 2, the mean number of elective surgeries performed weekly before the start of the pandemic was 26.85 ± 23.52 and after the start of the pandemic, it was 7.65 ± 13.49 (p <0.001). There were significantly higher reported levels of preparedness in Group 1 in terms of: theoretical training of the staff, equipping the staff and adapting the operating theater to safely perform procedures on patients with COVID-19. Overall, 62.23% of responders presume being infected with SARS-CoV-2. C o n c l u s i o n s: SARS-CoV-2 pandemic had a significantly negative impact on surgical wards. Despite the preparations, the number of responders who presume being infected with SARS-CoV-2 during present crisis is high.

Impact of SARS-CoV-2 pandemic on bariatric care in Poland: results of national survey

Background

The SARS-CoV-2 pandemic has reached Poland on March 4th, 2020 and undoubtedly affected all areas of life and medical care, including bariatric care. The study was planned to identify the impact of the SARS-CoV-2 pandemic on bariatric care in Poland.

Methods

The online survey was designed and distributed to bariatric surgeons. The questionnaire was divided into three parts: demographic characteristics of participants and their bariatric centers, examining the impact of the pandemic on the bariatric care and last part with questions about planned care after the pandemic.

Results

49 surgeons participated in the survey. 27 (55%) participants worked in hospitals transformed into COVID-dedicated units. Only 9 (18%) respondents declared uninterrupted bariatric surgery during a pandemic. 91% of surgeons declared continuation of bariatric care with telemedicine techniques. All participants declared a high willingness to resume bariatric surgery after the SARS-CoV-2 pandemic and responded that bariatric procedures should resume immediately when World Health Organisation (WHO) announces the end of a pandemic regardless of oncological treatment. 90% of respondents believe that the pandemic will not affect the safety of bariatric procedures in the future.

Conclusions

Access to bariatric care during the pandemic is limited and redirected to telemedicine. Surgeons are ready to resume bariatric operations immediately after the pandemic, but its end is difficult to determine. In surgeons’ opinion pandemic will not affect the safety of bariatric surgery in the future. The extended waiting list and financial aspects will be the main issues after the pandemic.

Bariatric Surgery During COVID-19 Pandemic from Patients' Point of View-The Results of a National Survey

INTRODUCTION

The aim of the study was to investigate the impact of the COVID-19 pandemic on bariatric care from the patients' point of view. The COVID-19 pandemic has perturbed the functioning of healthcare systems around the world and led to changes in elective surgical care, with bariatric procedures being postponed until the end of pandemic. There is no data in the literature about the effect of a new epidemiological situation on bariatric patients.

METHODS

The study was designed as an online survey containing multiple open questions about bariatric care during the COVID-19 pandemic. The survey was conducted among pre- and postoperative bariatric patients.

RESULTS

Out of 800 respondents, 74.53% felt anxiety about their health in regard to the present epidemiologic state. Some (72.25%) were aware of the fact that obesity was an important risk factor that could impair the course of the COVID-19 disease. Almost 30% of respondents admitted having put on weight, significantly more in the group of preoperative patients (43.8% vs 22.69%; p < 0.001). Only 20.92% of patients had a possibility of continuing direct bariatric care; 67.3% of patients had an opportunity of remote contact with a bariatric specialist, including online consultations, teleconsultations and social media meetings.

CONCLUSIONS

Limited access to medical care and quarantine lockdown may result in a deterioration of long-time operation outcomes and lower weight losses. Patients should be encouraged to profit from online consultations with specialists and telemedicine to reduce the negative effects of the pandemic on their health.

Various Endoscopic Techniques for Treatment of Consequences of Acute Necrotizing Pancreatitis: Practical Updates for the Endoscopist

Despite great progress in acute pancreatitis (AP) treatment over the last 30 years, treatment of the consequences of acute necrotizing pancreatitis (ANP) remains controversial. While numerous reports on minimally invasive treatment of the consequences of ANP have been published, several aspects of interventional treatment, particularly endoscopy, are still unclear. In this article, we attempt to discuss these aspects and summarize the current knowledge on endoscopic therapy for pancreatic necrosis. Endotherapy has been shown to be a safe and effective minimally invasive treatment modality in patients with consequences of ANP. The evolution of endoscopic techniques has made endoscopic drainage more effective and reduced the use of other minimally invasive therapies for pancreatic necrosis.

What Makes Bariatric Operations Difficult-Results of a National Survey

Background and objective: The most commonly performed bariatric procedures include laparoscopic sleeve gastrectomy (LSG), laparoscopic Roux-en-Y gastric bypass (LRYGB), and one anastomosis gastric bypass-mini gastric bypass (OAGB-MGB). A study comparing the degree of difficulty among those procedures could serve as a guide for decision making in bariatric surgery and further improve training programs for general surgery trainees. The aim of this study was to compare the subjective level of technical difficulty of LSG, LRYGB, and OAGB-MGB as perceived by surgeons and surgical residents. Materials and Methods: An anonymous internet-based survey was designed to evaluate the subjective opinions of surgeons and surgical residents in training in Poland. It covered baseline characteristics of the participants, difficulty of LSG, OAGB-MGB, LRYGB and particular stages of each operation assessed on a 1-5 scale. Results: Overall, 70 surgeons and residents participated in our survey. The mean difficulty degree of LSG was 2.34 ± 0.89. The reinforcing staple line with sutures was considered most difficult stage of this operation (3.17 ± 1.19). The LRYGB operation had an average difficulty level of 3.87 ± 1.04. Creation of the gastrojejunostomy was considered the most difficult stage of LRYGB with a mean difficulty level (3.68 ± 1.16). Responders to our survey assessed the mean degree of difficulty of OAGB-MGB as 2.34 ± 0.97. According to participating surgeons, creating the gastrojejunostomy is the most difficult phase of this operation (3.68 ± 1.16). Conclusion: The LSG is perceived by surgeons as a relatively easy operation. The LRYGB was considered to be the most technically challenging procedure in our survey. Operative stages, which require intra-abdominal suturing with laparoscopic instruments, seem to be the most difficult phases of each operation.

GC-MS application in determination of volatile profiles emitted by infected and uninfected human tissue

Volatile organic compounds (VOCs) released into the headspace air over human tissues infected with different bacteria were investigated in this work. The above-mentioned VOCs result both from bacterial metabolic processes (pathogen-specific signals) and from the matrix (tissue samples themselves). The objective of this study was to investigate whether one could reliably identify various microorganism strains that exist inside infected tissue samples by direct monitoring of the headspace atmosphere above their cultures. Headspace samples were directly interrogated using a GC-MS system, which produced distinct profiles for samples contaminated with single bacterial strains or with multiple strains (mixed infections). Principal component analysis (PCA) and predictive analysis based on receiver operating characteristics curves (ROC) were the statistical procedures utilized for differentiating between infected and uninfected samples, while network analysis and heat-mapping were used to highlight the connections between emitted volatiles and infectious pathogens. By using ROC curves, obtained results demonstrated that the area under the ROC (95% probability interval) was 0.86 in case of infected samples and 0.48 for uninfected samples. On the other hand, PCA highlighted separation between components coming from infected and uninfected patients, where 67% of variance was described from the first 2 principal components. The biomarker chemicals documented from this work, as well as the developed methodology may ultimately be applied to identify bacterial infections by analyzing exhaled breath.

Effect of dietary canthaxanthin and iodine on the production performance and egg quality of laying hens

In this study, we aimed to evaluate the effect of canthaxanthin (CX) and iodine (I) on the production of laying hens, on counteracting debilitation of the vitelline membrane, and on inhibiting Salmonella growth in eggs stored at 30°C. Three hundred hens were reared in cages. Birds were divided into six feeding groups (10 hens × 5 repetitions) that were administered 0, 3 or 6 ppm of CX and 1 or 10 ppm of I with their diets. Laying rate, egg weights, and feed conversion ratios were controlled. The quality of fresh eggs was assessed in wks 25-26, 48-50 and 62-63 of hens lives. An additional batch of eggs was incubated at the temperature of 30°C, and egg quality changes were monitored on days 3, 6 and 9 of storage. Additionally, eggs collected from four experimental groups of hens whose diets had been iodated with 1 or 10 ppm of I and supplemented with 0 or 6 ppm of CX were infected under laboratory conditions with Salmonella, and incubated for 5 and 10 d. The laying rate, egg weights, and feed conversion ratio were significantly improved. Dietary inclusion of CX contributed to a higher resistance of the vitelline membrane of egg yolks, but only for fresh eggs. Vitelline membrane degradation during egg storage at 30°C was significantly counteracted by dietary inclusion of I at a dose of 10 ppm. The same I dose resulted in the complete inhibition of Salmonella growth until day 10 of incubation, but exclusively for eggs collected from 40-week-old hens. Dietary supplementation with 10 ppm of I was found to impart high level of resistance to the vitelline membrane against the growth of Salmonella in case of eggs stored at 30°C; therefore, I was found to be more beneficial by ensuring longer preservation than that of CX. However, dietary supplementation with CX was found to increase the resistance of vitelline membrane in fresh eggs.

Withdrawal from bariatric treatment - an analysis under various demographic conditions

Poland is high on a list of countries affected by epidemics of obesity, a problem that has especially suddenly increased in the post-transformation period.

MATERIALS AND METHOD

Documentation of 115 subsequent patients diagnosed with grade 3 obesity, considered eligible for surgical treatment, was analysed since 2015. A subgroup of 68 patients was selected from this group and the included patients who decided to cancel their treatment at various stages. Their history since presentation at the obesity treatment centre, BMI with its history, age, education and place of residence were analysed, followed by a telephone survey. 42 patients were finally contacted. Special attention was placed on the analysis of patients taking into account their place of residence. Patients were divided into inhabitants of rural and urban areas.

RESULTS

In the study group of 68 patients, 19 (27.9%) were inhabitants of rural areas and 49 (72.1%) of urban areas. Women accounted for 67.6%, and men for 32.4%. The mean age of patients when they presented for treatment was 43 years. On average, men presented 5 years later compared to women. The mean BMI on qualification for treatment of obesity was 47.6 kg/m². The mean BMI max - 49.6 kg/m². There were no differences regarding education in both populations. Despite the lack of differences regarding changes in the BMI since withdrawal from treatment, as many as 63% of patients from rural areas reached the BMI max in this time.

CONCLUSIONS

There were demographic differences between the degree of obesity observed among patients receiving bariatric treatment, and inhabitants of urban areas were favoured. Patients from rural areas who withdrew from bariatric treatment and were left without medical care significantly more often achieved their maximum body weight, when compared to those living in urban areas. The active participation of physicians, both specialists and general practitioners, in the life of obese patients is imperative.

Interaction of graphene family materials with Listeria monocytogenes and Salmonella enterica

Graphene family materials have unique properties, which make them valuable for a range of applications. The antibacterial properties of graphene have been reported; however, findings have been contradictory. This study reports on the antimicrobial proprieties of three different graphene materials (pristine graphene (pG), graphene oxide (GO), and reduced graphene oxide (rGO)) against the food-borne bacterial pathogens Listeria monocytogenes and Salmonella enterica. A high concentration (250 μg/mL) of all the analyzed graphenes completely inhibited the growth of both pathogens, despite their difference in bacterial cell wall structure. At a lower concentration (25 μg/mL), similar effects were only observed with GO, as growth inhibition decreased with pG and rGO at the lower concentration. Interaction of the nanoparticles with the pathogenic bacteria was found to differ depending on the form of graphene. Microscopic imaging demonstrated that bacteria were arranged at the edges of pG and rGO, while with GO, they adhered to the nanoparticle surface. GO was found to have the highest antibacterial activity.

A new approach for antibiotic drugs determination in human plasma by liquid chromatography-mass spectrometry

Sensitive and selective analytical procedures based on high performance liquid chromatography with mass spectrometric detection were developed for the determination of linezolid (LIN) and amoxicillin (AMOX) in human plasma samples. Samples were prepared by applying protein precipitation (PP), solid phase extraction (SPE), and microextraction in packed syringe (MEPS). The analytical separation was carried out using reversed phase liquid chromatography in isocratic mode. All analytes were monitored by mass spectrometry (MS) detection in the product ion mode and the method was validated covering the corresponding therapeutic range of 1-30 μg/mL and 1-50 μg/mL for LIN and AMOX respectively. The assay was linear over AMOX and LIN concentration ranges. The method provided good validation data: accuracy (102.9% (LIN), 100.9% (AMOX)), limit of detection (0.1407 ng/mL (LIN); 0.1341 ng/mL (AMOX); quantification (0.3814 ng/mL (LIN), 0.4249 ng/mL (AMOX)) and acceptable stability within 24h in the auto-sampler. Three different methods were compared as regards precision, accuracy, recovery and matrix effects. The proposed methods offer a fast and simple way to determine selected antibiotic drugs in human plasma that could be applied in pharmacokinetic studies.

Development of novel molecularly imprinted solid-phase microextraction fibers and their application for the determination of antibiotic drugs in biological samples by SPME-LC/MS(n)

Novel molecularly imprinted polymer (MIP)-coated fibers for solid-phase microextraction (SPME) fibers were prepared by using linezolid as the template molecule. The characteristics and application of these fibers were investigated. The polypyrrole, polythiophene, and poly(3-methylthiophene) coatings were prepared in the electrochemical polymerization way. The molecularly imprinted SPME coatings display a high selectivity toward linezolid. Molecularly imprinted coatings showed a stable and reproducible response without any influence of interferents commonly existing in biological samples. High-performance liquid chromatography with spectroscopic UV and mass spectrometry (MS) detectors were used for the determination of selected antibiotic drugs (linezolid, daptomycin, amoxicillin). The isolation and preconcentration of selected antibiotic drugs from new types of biological samples (acellular and protein-free simulated body fluid) and human plasma samples were performed. The SPME MIP-coated fibers are suitable for the selective extraction of antibiotic drugs in biological samples.

The clinical use of a fast screening test based on technology of capillary zone electrophoresis (CZE) for identification of Escherichia coli infection in biological material

BACKGROUND

Escherichia coli is a Gram-negative bacterium which is a basic, symbiotic element of the physiological flora of the large intestine of humans and warm-blooded animals. However, in specific cases it may become a very dangerous pathogen (eg, diarrhoea, infection of the urinary tract, lungs, and generalized infections). Its early detection, as a cause of infectious disease, helps to achieve optimal treatment results; however, classical microbiological tests require at least 24 hours from sample taking to diagnosis.

MATERIAL/METHODS

We present a unique solution based on CZE technologies enabling identification of E. coli presence in studied sample within half an hour. Altogether, 30 E. coli-infected wounds and ulcerations were examined, comparing the results obtained by classical culture method with the result of capillary zone electrophoresis (CZE) electropherogram.

RESULTS

The method, which does not require any preparation of the sample, achieved 86.7% sensitivity and 85%specificity in the examined clinical material (infections of surgical wounds).

CONCLUSIONS

The obtained results enable reliable, very fast testing for E. coli as a pathogen.

Clinical application of a rapid microbiological test based on capillary zone electrophoresis to assess local skin infection

Background

The basic clinical problem associated with infection treatment is the fact that classic, commonly and routinely used isolation and identification methods are based on long-term processes of a phenotypic analysis of microorganisms. Consequently sometimes, especially in small centres, rapid implementation of antibacterial treatment becomes delayed.

The work presents the initial results of rapid microbiological identification based on an original method of capillary zone electrophoresis (CZE). The study involved the analysis of 78 biological samples from post-operative wounds and trophic ulcers.

Results

The attempt was made to identify individual bacterial species based on characteristic features of electropherograms achieved. Finally, G(+) cocci type bacteria and different G(-) rods were identified with sensitivity of 88.1% and specificity of 100%.

Conclusions

Based on the clinical trials using an electrophoretic technique in the field of microbiological diagnostics of infected exudate from a post-operative wound it can be concluded that it is a rapid and relatively sensitive method for initial identification of infectious pathogens.

Visualisation of morphological interaction of diamond and silver nanoparticles with Salmonella Enteritidis and Listeria monocytogenes

Currently, medicine intensively searches for methods to transport drugs to a target (sick) point within the body. The objective of the present investigation was to evaluate morphological characteristics of the assembles of silver or diamond nanoparticles with Salmonella Enteritidis (G-) or Listeria monocytogenes (G+), to reveal possibilities of constructing nanoparticle-bacteria vehicles. Diamond nanoparticles (nano-D) were produced by the detonation method. Hydrocolloids of silver nanoparticles (nano-Ag) were produced by electric non-explosive patented method. Hydrocolloids of nanoparticles (200 microl) were added to bacteria suspension (200 microl) in the following order: nano-D + Salmonella E.; nano-D + Listeria monocytogenes; nano-Ag + Salmonella E; nano-Ag + Listeria monocytogenes. Samples were inspected by transmission electron microscopy. Visualisation of nanoparticles and bacteria interaction showed harmful effects of both nanoparticles on bacteria morphology. The most spectacular effect of nano-D were strong links between nano-D packages and the flagella of Salmonella E. Nano-Ag were closely attached to Listeria monocytogenes but not to Salmonella E. There was no evidence of entering nano-Ag inside Listeria monocytogenes but smaller particles were placed inside Salmonella E. The ability of nano-D to attach to the flagella and the ability of nano-Ag to penetrate inside bacteria cells can be utilized to design nano-bacteria vehicles, being carriers for active substances attached to nanoparticles.

Visualization of interaction between inorganic nanoparticles and bacteria or fungi

PURPOSE

The objective of the present investigation was to evaluate the morphologic characteristics of self-assemblies of diamond (nano-D), silver (nano-Ag), gold (nano-Au), and platinum (nano-Pt) nanoparticles with Staphylococcus aureus (bacteria) and Candida albicans (fungi), to determine the possibility of constructing microorganism-nanoparticle vehicles.

METHODS

Hydrocolloids of individual nanoparticles were added to suspensions of S. aureus and C. albicans. Immediately after mixing, the samples were inspected by transmission electron microscopy.

RESULTS

Visualization of the morphologic interaction between the nanoparticles and microorganisms showed that nano-D, which are dielectrics and exhibit a positive zeta potential, were very different from the membrane potentials of microorganisms, and uniformly surrounded the microorganisms, without causing visible damage and destruction of cells. All metal nanoparticles with negative zeta potential had cell damaging properties. Nano-Ag showed the properties of self-organization with the cells, disintegrating the cell walls and cytoplasmic membranes, and releasing a substance (probably cytoplasm) outside the cell. Arrangement of nano-Au with microorganisms did not create a system of self-organization, but instead a "noncontact" interaction between the nanoparticles and microorganisms was observed to cause damage to fungal cells. Nano-Pt caused both microorganisms to release a substance outside the cell and disintegrated the cytoplasmic membrane and cell wall.

CONCLUSION

Nano-Ag, nano-Au, and nano-Pt (all metal nanoparticles) are harmful to bacteria and fungi. In contrast, nano-D bind closely to the surface of microorganisms without causing visible damage to cells, and demonstrating good self-assembling ability. The results indicate that both microorganisms could be used as potential carriers for nano-D.

Surfactant protein A (SP-A)-mediated clearance of Staphylococcus aureus involves binding of SP-A to the staphylococcal adhesin eap and the macrophage receptors SP-A receptor 210 and scavenger receptor class A

Staphylococcus aureus causes life-threatening pneumonia in hospitals and deadly superinfection during viral influenza. The current study investigated the role of surfactant protein A (SP-A) in opsonization and clearance of S. aureus. Previous studies showed that SP-A mediates phagocytosis via the SP-A receptor 210 (SP-R210). Here, we show that SP-R210 mediates binding and control of SP-A-opsonized S. aureus by macrophages. We determined that SP-A binds S. aureus through the extracellular adhesin Eap. Consequently, SP-A enhanced macrophage uptake of Eap-expressing (Eap(+)) but not Eap-deficient (Eap(-)) S. aureus. In a reciprocal fashion, SP-A failed to enhance uptake of Eap(+) S. aureus in peritoneal Raw264.7 macrophages with a dominant negative mutation (SP-R210(DN)) blocking surface expression of SP-R210. Accordingly, WT mice cleared infection with Eap(+) but succumbed to sublethal infection with Eap- S. aureus. However, SP-R210(DN) cells compensated by increasing non-opsonic phagocytosis of Eap(+) S. aureus via the scavenger receptor scavenger receptor class A (SR-A), while non-opsonic uptake of Eap(-) S. aureus was impaired. Macrophages express two isoforms: SP-R210(L) and SP-R210(S). The results show that WT alveolar macrophages are distinguished by expression of SP-R210(L), whereas SR-A(-/-) alveolar macrophages are deficient in SP-R210(L) expressing only SP-R210(S). Accordingly, SR-A(-/-) mice were highly susceptible to both Eap(+) and Eap(-) S. aureus. The lungs of susceptible mice generated abnormal inflammatory responses that were associated with impaired killing and persistence of S. aureus infection in the lung. In conclusion, alveolar macrophage SP-R210(L) mediates recognition and killing of SP-A-opsonized S. aureus in vivo, coordinating inflammatory responses and resolution of S. aureus pneumonia through interaction with SR-A.

Visualization of gold and platinum nanoparticles interacting with Salmonella enteritidis and Listeria monocytogenes

PURPOSE

Rapid development of nanotechnology has recently brought significant attention to the extraordinary biological features of nanomaterials. The objective of the present investigation was to evaluate morphological characteristics of the assembles of gold and platinum nanoparticles (nano-Au and nano-Pt respectively), with Salmonella Enteritidis (Gram-negative) and Listeria monocytogenes (Gram-positive), to reveal possibilities of constructing bacteria-nanoparticle vehicles.

METHODS

Hydrocolloids of nano-Au or nano-Pt were added to two bacteria suspensions in the following order: nano-Au + Salmonella Enteritidis; nano-Au + Listeria monocytogenes; nano-Pt + Salmonella Enteritidis; nano-Pt + Listeria monocytogenes. Samples were inspected by transmission electron microscope.

RESULTS

Visualization of morphological interaction between nano-Au and Salmonella Enteritidis and Listeria monocytogenes, showed that nano-Au were aggregated within flagella or biofilm network and did not penetrate the bacterial cell. The analysis of morphological effects of interaction of nano-Pt with bacteria revealed that nano-Pt entered cells of Listeria monocytogenes and were removed from the cells. In the case of Salmonella Enteritidis, nano-Pt were seen inside bacteria cells, probably bound to DNA and partly left bacterial cells. After washing and centrifugation, some of the nano-Pt-DNA complexes were observed within Salmonella Enteritidis.

CONCLUSION

The results indicate that the bacteria could be used as a vehicle to deliver nano-Pt to specific points in the body.

Combination of capillary electrophoresis, PCR and physiological assays in differentiation of clinical strains of Staphylococcus aureus

Fast, sensitive and cheap determination of pathogenic bacteria is extremely important in many branches, for example biotechnology, quality control, analysis of samples and antimicrobial therapy. The development and application of analytical techniques in practice could provide new possibilities in this regard. The bacterial pathogen Staphylococcus aureus is responsible for a significant amount of human morbidity and mortality. Rapid and sensitive determination is therefore very important. In the present study, novel methods, based on capillary zone electrophoresis and (as confirmation of these results) molecular analysis of a part of the coag gene, were developed for identification and differentiation of three S. aureus strains. The electrophoretic measurements rely on the differential mobility of bacteria in the fused silica capillary under the direct current electric field. To perform coagulase gene typing, the repeated units encoding hypervariable regions of the S. aureus gene were amplified using the PCR technique followed by restriction enzyme digestion and analysis of restriction fragment length polymorphism patterns as well as sequencing. Finally, the results of electrophoretic measurements with molecular analysis were compared.

Granulocyte-macrophage colony stimulating factor-mediated innate responses in tuberculosis

The mechanisms by which GM-CSF mediates bacterial clearance and inflammation during mycobacterial infection are poorly understood. The objective of this work was to determine how GM-CSF alters pulmonary mycobacterial infection in vivo. Differences in GM-CSF levels in the lungs of normal mice (GM(+/+)), transgenic GM-CSF-deficient (GM-CSF(-/-)), and transgenic mice with high GM-CSF expression only in lung epithelial cells (SP-C-GM-CSF(+/+)/GM(-/-)) did not affect pulmonary infection rates caused by either the attenuated Mycobacterium bovis BCG or the virulent Mycobacterium tuberculosis H37Rv. However, in contrast to findings with BCG, all GM-CSF(-/-) and SP-C-GM-CSF(+/+)/GM(-/-) mice succumbed prematurely to virulent H37Rv. Granuloma formation was impaired in both GM-CSF(-/-) and SP-C-GM-CSF(+/+)/GM(-/-) mice regardless of mycobacterial virulence. However, H37Rv-infected GM-CSF(-/-) mice suffered broncho-alveolar destruction, edema, and necrosis while only short-lived granulomas were observed in SP-C-GM-CSF(+/+)/GM(-/-) mice. Bone marrow-derived macrophages, but not dendritic cells of SP-C-GM-CSF(+/+)/GM(-/-) mice, were hypo-responsive to mycobacterial infection. Surfactant protein levels were differentially influenced by BCG and H37Rv. We conclude that GM-CSF has an essential protective role first in preserving alveolar structure and second in regulating macrophages and dendritic cells to facilitate containment of virulent mycobacteria in pulmonary granulomas. However, precise regulation of lung GM-CSF is vital to effective control of M. tuberculosis.

Rapid identification ofHelicobacter pylori by capillary electrophoresis: an overview

Helicobacter pylori can cause gastritis and peptic ulcers and is directly associated with the development of gastric cancer. There are many types of diagnostic methods used to identification H. pylori (invasive and non-invasive), but these methods usually require time-consuming and laborious procedures and therefore are not capable of fast diagnosis in cases of emergency. This contribution describes the new achievements, interdisciplinary significance and some future directions in the application of capillary electrophoresis for determination of H. pylori.

Rapid identification ofEscherichia coli andHelicobacter pylori in biological samples by capillary zone electrophoresis

The differences in surface charge of different bacteria can be exploited for their separation by capillary electrophoresis. However, this method of separation of microorganisms is beset with various drawbacks such as adhesion of bacteria to the fused silica surface or cluster formation. To overcome these phenomena we investigated the addition of poly(ethylene oxide) as a focusing agent to the running buffer and used calcium and myoinositol hexakisphosphate as specific ions that interact with the bacterial surface, changing its electrical properties and electrophoretic mobilities. In the present work, we applied CZE to identification of E. coli in infected urine (direct injection) from patients with urinary tract infections and to identification of Helicobacter pylori, which is a gram-negative bacillus responsible for one of the most common infections found in humans worldwide. Helicobacter pylori colonize the stomach and are responsible for severe diseases of the gastric tract, ranging from chronic gastric ulcer to gastric cancer.

Identification of the surfactant protein A receptor 210 as the unconventional myosin 18A

Mass spectrometric characterization of the surfactant protein A (SP-A) receptor 210 (SP-R210) led to the identification of myosin (Myo) XVIIIA and nonmuscle myosin IIA. Antibodies generated against the unique C-terminal tail of MyoXVIIIA revealed that MyoXVIIIA, MyoIIA, and SP-R210 have overlapping tissue distribution, all being highly expressed in myeloid cells, bone marrow, spleen, lymph nodes, and lung. Western blot analysis of COS-1 cells stably transfected with either MyoXVIIIA or MyoIIA indicated that SP-R210 antibodies recognize MyoXVIIIA. Furthermore, MyoXVIIIA but not MyoIIA localized to the surface of COS-1 cells, and most importantly, expression of MyoXVIIIA in COS-1 cells conferred SP-A binding. Western analysis of recombinant MyoXVIIIA domains expressed in bacteria mapped the epitopes of previously derived SP-R210 antibodies to the neck region of MyoXVIIIA. Antibodies raised against the neck domain of MyoXVIIIA blocked the binding of SP-A to macrophages. Together, these findings indicate that MyoXVIIIA constitutes a novel receptor for SP-A.

Influence of dendritic cells on the in vitro allogeneic cytotoxic reaction of lymphoid cells derived from normal or Listeria innocua-infected BALB/c mice

The role of lymphoid dendritic cells (DCs) in the development of an allogeneic cytotoxic reaction in vitro was examined. The T+B and T cell subsets originating from the spleens or lymph nodes of normal and Listeria innocua-infected BALB/c mice were used as the effector cells. Their cytotoxicity to 51Cr-labeled C3H fibroblasts was determined after removal of DCs and replacing them again. Moreover, the influence of exogenous mrIL-12 on the potency of DCs in the allogeneic reaction developed in vitro was checked. It was found that the DC-deprived T+B or T subsets of splenocytes, regardless of their origin, exhibited 27-38% lower cytotoxicity than those accompanied by natural DCs. The cytotoxicity of these subsets from normal lymph nodes decreased by 22%, while the activity of bacteria-primed cells dropped by 38%. Replenishing effector cells with isolated DCs restored their cytotoxicity. Pulsation of normal DCs with IL-12 had no effect on the recovery of normal cell cytotoxicity. However, the IL-12-pulsed DCs were able to intensify the cytotoxicity of T+B subsets derived from the spleens or lymph nodes of L. innocua-infected mice. The results suggest that the alloantigen presentation by DCs to cytotoxic lymphocytes also takes place in the reaction developed in vitro, regardless of effector cell origin.

[Interleukin 12 (IL-12) and its receptor]

This article reviews of recent data on the structure of IL-12 and the function of its receptor (IL-12R). It presents a new opinion on the role of its subunits in the cytokine activity and on the signal transmission via IL-12R in the process of cell activation by IL-12.

Quantitative reactions of anti 5,9-dimethylchrysene dihydrodiol epoxide with DNA and deoxyribonucleotides

Native as well as denatured calf thymus DNA, deoxyguanylic and deoxyadenylic acid, respectively, were reacted with the racemic anti 5,9-dimethylchrysene dihydrodiol epoxide (5,9-DMCDE). The deoxyribonucleoside adducts were separated by HPLC and characterized by CD and NMR. Approximately 17% of the epoxide was trapped by native DNA and 76% of the adducts were derived from the RSSR enantiomer. The ratios of dAdo/dGuo modification in DNA were 14/86 and 19/81 for RSSR and SRRS enantiomers, respectively. By monitoring the product yields of anti 5,9-DMCDE with DNA and deoxyribonucleotides, we hoped to gain further insight into the factors responsible for deoxyguanosine adduct formation by 5-methylchrysene dihydrodiol epoxide (5-MCDE) compared to 5, 6-dimethylchrysene dihydrodiol epoxide (5,6-DMCDE). The adduct yields in deoxyribonucleotide reactions of 5,9-DMCDE were slightly higher than those from 5-MCDE. However, the reaction yields of 5, 9-DMCDE with DNA were lower than those with 5-MCDE in most cases, particularly for the cis and trans deoxyadenosine adducts. It seems that the 9-methyl group of 5,9-DMCDE significantly influences adduct formation with the deoxyadenosine residue in DNA in contrast to the 6-methyl group of 5,6-DMCDE. The 9-methyl group sterically decreases deoxyadenosine adduct yields more in reaction with native DNA than denatured DNA, but it has little effect on deoxyribonucleotide reactions. Adduct formation with deoxyguanosine residues in DNA by all three dihydrodiol epoxides correlate with their respective tumorigenic and mutagenic activities.

Reactions of dihydrodiol epoxides of 5-methylchrysene and 5, 6-dimethylchrysene with DNA and deoxyribonucleotides

Both syn and anti dihydrodiol epoxides from 5-methylchrysene (5-MCDE) and 5,6-dimethylchrysene (5,6-DMCDE) were reacted under the same conditions with native DNA, denatured DNA, and purine deoxyribonucleotides, and the products were quantified. The extents of reaction with the deoxyribonucleotides were consistently greater for 5,6-DMCDE than for 5-MCDE. The yield of adducts in the reaction with DNA ranged from being a few-fold to 50-fold greater than those found in the corresponding deoxyribonucleotide reactions for both 5-MCDE and 5,6-DMCDE. The DNA-dependent enhancement of product yield was greater for 5-MCDE than for 5,6-DMCDE with a few exceptions among cis and trans deoxyadenosine adducts. The most substantial differences in DNA-dependent enhancement were found for deoxyguanosine adducts; thus, steric hindrance between the 6-methyl group in the 5,6-DMCDE and the minor groove in the DNA double helix may account for the greater DNA-dependent enhancement found in the 5-MCDE reactions.

DNA reactions, mutagenic action and stealth properties of polycyclic aromatic hydrocarbon carcinogens (review)

A brief summary of recent research, primarily from the authors' laboratory, on polycyclic aromatic hydrocarbon carcinogens with respect to their DNA adduct formation, the mutational properties of these adducts and the effects of hydrocarbon dihydrodiol epoxide metabolites on the passage of cells through the cell cycle is presented. The concept of stealth properties of potent carcinogens, i.e. their ability to damage DNA without inducing a G1 arrest, is discussed. Also, mutation studies with dihydrodiol epoxide metabolites, the sequence-dependence of site-specific mutation, as well as the selectivity of hydrocarbon-DNA adduct formation are summarized.

The host response to Listeria monocytogenes mutants defective in genes encoding phospholipases C (plcA, plcB) and actin assembly (actA)

Several genes involved in the determination of Listeria monocytogenes pathogenesis have been identified. Among them, plcA gene encodes phosphatidylinositol-specific phospholipase C (PI-PLC), plcB gene encodes a broad-range phospholipase C (PC-PLC), and actA encodes a protein contributing to actin assembly in infected cells. The interaction of L. monocytogenes wild type (LO 28) strain and two derivative mutants, plcA- (BUG 206) and actA-/plcB- (LUT 12), with macrophages and T lymphocytes was investigated in a mouse model of listeriosis. Both mutants showed evidence of attenuation. The plcA- mutant, but not the plcB- mutant, expressed an increase in susceptibility to the anti-listerial activity of macrophages. Both mutants showed a decreased ability to induce IL-12 production by bone marrow macrophages when co-stimulated with E. coli LPS or IFN-gamma. In vivo, L. monocytogenes plcA- mutant was found to be a more effective stimulator of T cells than the wild LO 28 strain.

Application of mixed mobile phases and a step gradient method in capillary electrochromatography for the separation of isomeric polycyclic aromatic hydrocarbon-deoxyribonucleoside adduct mixtures prepared in vitro

Capillary electrochromatography (CEC) was used for the analysis of mixtures of neutral isomeric compounds derived from the reaction of carcinogenic hydrocarbon (benzo[g]chrysene and 5,6-dimethylchrysene) dihydrodiol epoxides with calf thymus deoxyribonucleic acid (DNA). The CEC analysis demonstrated higher resolution, greater speed and lower analyte consumption than high-performance liquid chromatography (HPLC) in the analysis of the same samples using the same type of stationary phase. Proper selection of the mixed mobile phases was critical for the separation of these complex mixtures with enhanced speed and selectivity. The use of a step gradient further improved the speed of the CEC analysis resulting in electrochromatograms that required only 25-70% of the corresponding HPLC analysis times.

Characterization of DNA adducts formed by the four configurationally isomeric 5,6-dimethylchrysene 1,2-dihydrodiol 3,4-epoxides

The DNA adducts formed from the racemic syn and anti dihydrodiol epoxides of 5,6-dimethylchrysene were characterized through various spectroscopic methods. Substantial reaction with the amino groups of both deoxyadenosine and deoxyguanosine residues were detected with both the syn and anti derivatives. The chemical shifts and coupling constants for the cis and trans opened adducts from the syn dihydrodiol epoxide were distinctly different, whereas for the anti dihydrodiol epoxide these properties were fairly similar for cis and trans adducts. In the latter case, assignment of trans and cis configurations was less obvious, and the finding that trans adducts have always predominated over cis adducts for all dihydrodiol epoxides studied to date was helpful in making these assignments. The preferential formation of cis adducts in DNA by the syn dihydrodiol epoxide is more like the chemistry of the dihydrodiol epoxide of benzo[c]phenanthrene than of benzo[g]chrysene, although both of these, like 5,6-dimethylchrysene, are non-planar compounds.