A review on antibiotic resistance: origin and mechanisms of bacterial resistance as biological phenomenon

Antimicrobial resistance is a natural biological phenomenon in their struggle for existence and represents a major health care issue, associated with high mortality and morbidity. The first cases of mass emergence of resistant strains were observed in the middle of the 20th century, and since then cases of resistance have been reported all over the world, and in the last two decades even more frequently are reported multiple bacterial resistance. Factors that contribute to the development of bacteria resistance are abuse in the use of antibacterial agents, in humans or livestock, and releases of antibacterial agents into the environment. Moreover, the development of new effective antibiotics is decreasing, contrary to increasing the overall effort for the synthesis of new ones. Identification and reporting of bacterial resistance, as well as monitoring of the use of antibiotics in the outpatient and inpatient setting, today is the obligation of all countries

Assesment of radiotherapy effects on the blood flow in gingiva and dental pulp : a laser Doppler flowmetry study

Objective: This study aims to determine and compare the dental pulp and gingival blood flow in patients referred for oropharyngeal radiotherapy (RT) at three different time points: before the start, immediately after, and six months following the completion of RT. The aim is also to evaluate the dependence of the pulp and gingival blood flow on the radiation dose. Methodology: A prospective study included 10 patients referred for intensity-modulated RT (IMRT) in the oropharyngeal region, with at least one intact tooth surrounded by a healthy gingiva. The dose received by each selected tooth and adjacent gingiva was determined according to the map of treatment planning and computer systems. The blood flow measurements were performed using the laser Doppler flowmetry (LDF) method. Results: Comparing vascular flows at three different time points, the median blood flow in the dental pulp showed no statistically significant difference (p=0.325), contrary to gingiva (p=0.011). Immediately after RT completion, the gingival flow significantly increased compared to its starting point (p=0.012). The pulp flow correlated negatively with the radiation dose, whereas a strong correlation was noted 6 months following the RT completion. Conclusions: RT caused a significant acute gingival blood flow increase, followed by a long-term (over six months) tendency to return to the starting levels. The dental pulp blood flow is differently affected by higher radiation doses (over 50Gy) in comparison to lower doses (below 50Gy). During RT planning, considering the possibility of protecting the teeth localized near the Gross Tumor Volume as a sensitive organ is recommended

Trauma of the frontal region is influenced by the volume of frontal sinuses. A finite element study

Anatomy of frontal sinuses varies individually, from differences in volume and shape to a rare case when the sinuses are absent. However, there are scarce data related to influence of these variations on impact generated fracture pattern. Therefore, the aim of this study was to analyse the influence of frontal sinus volume on the stress distribution and fracture pattern in the frontal region. The study included four representative Finite Element models of the skull. Reference model was built on the basis of computed tomography scans of a human head with normally developed frontal sinuses. By modifying the reference model, three additional models were generated: a model without sinuses, with hypoplasic, and with hyperplasic sinuses. A 7.7 kN force was applied perpendicularly to the forehead of each model, in order to simulate a frontal impact. The results demonstrated that the distribution of impact stress in frontal region depends on the frontal sinus volume. The anterior sinus wall showed the highest fragility in case with hyperplasic sinuses, whereas posterior wall/inner plate showed more fragility in cases with hypoplasic and undeveloped sinuses. Well-developed frontal sinuses might, through absorption of the impact energy by anterior wall, protect the posterior wall and intracranial contents.This work was supported in part by grants from the Serbian Ministry of Education, Science and Technological Development III45005, III41007, ON174028 and EU project FP7 ICT SIFEM 600933

Thrombotic and bleeding complications in patients with chronic lymphocytic leukemia and severe COVID-19: a study of ERIC, the European Research Initiative on CLL

BACKGROUND: Patients with chronic lymphocytic leukemia (CLL) may be more susceptible to COVID-19 related poor outcomes, including thrombosis and death, due to the advanced age, the presence of comorbidities, and the disease and treatment-related immune deficiency. The aim of this study was to assess the risk of thrombosis and bleeding in patients with CLL affected by severe COVID-19. METHODS: This is a retrospective multicenter study conducted by ERIC, the European Research Initiative on CLL, including patients from 79 centers across 22 countries. Data collection was conducted between April and May 2021. The COVID-19 diagnosis was confirmed by the real-time polymerase chain reaction (RT-PCR) assay for SARS-CoV-2 on nasal or pharyngeal swabs. Severe cases of COVID-19 were defined by hospitalization and the need of oxygen or admission into ICU. Development and type of thrombotic events, presence and severity of bleeding complications were reported during treatment for COVID-19. Bleeding events were classified using ISTH definition. STROBE recommendations were used in order to enhance reporting. RESULTS: A total of 793 patients from 79 centers were included in the study with 593 being hospitalized (74.8%). Among these, 511 were defined as having severe COVID: 162 were admitted to the ICU while 349 received oxygen supplementation outside the ICU. Most patients (90.5%) were receiving thromboprophylaxis. During COVID-19 treatment, 11.1% developed a thromboembolic event, while 5.0% experienced bleeding. Thrombosis developed in 21.6% of patients who were not receiving thromboprophylaxis, in contrast to 10.6% of patients who were on thromboprophylaxis. Bleeding episodes were more frequent in patients receiving intermediate/therapeutic versus prophylactic doses of low-molecular-weight heparin (LWMH) (8.1% vs. 3.8%, respectively) and in elderly. In multivariate analysis, peak D-dimer level and C-reactive protein to albumin ratio were poor prognostic factors for thrombosis occurrence (OR?=?1.022, 95%CI 1.007?1.038 and OR?=?1.025, 95%CI 1.001?1.051, respectively), while thromboprophylaxis use was protective (OR?=?0.199, 95%CI 0.061?0.645). Age and LMWH intermediate/therapeutic dose administration were prognostic factors in multivariate model for bleeding (OR?=?1.062, 95%CI 1.017-1.109 and OR?=?2.438, 95%CI 1.023-5.813, respectively). CONCLUSIONS: Patients with CLL affected by severe COVID-19 are at a high risk of thrombosis if thromboprophylaxis is not used, but also at increased risk of bleeding under the LMWH intermediate/therapeutic dose administration

Canagliflozin and renal outcomes in type 2 diabetes and nephropathy

BACKGROUND Type 2 diabetes mellitus is the leading cause of kidney failure worldwide, but few effective long-term treatments are available. In cardiovascular trials of inhibitors of sodium–glucose cotransporter 2 (SGLT2), exploratory results have suggested that such drugs may improve renal outcomes in patients with type 2 diabetes. METHODS In this double-blind, randomized trial, we assigned patients with type 2 diabetes and albuminuric chronic kidney disease to receive canagliflozin, an oral SGLT2 inhibitor, at a dose of 100 mg daily or placebo. All the patients had an estimated glomerular filtration rate (GFR) of 30 to <90 ml per minute per 1.73 m2 of body-surface area and albuminuria (ratio of albumin [mg] to creatinine [g], >300 to 5000) and were treated with renin–angiotensin system blockade. The primary outcome was a composite of end-stage kidney disease (dialysis, transplantation, or a sustained estimated GFR of <15 ml per minute per 1.73 m2), a doubling of the serum creatinine level, or death from renal or cardiovascular causes. Prespecified secondary outcomes were tested hierarchically. RESULTS The trial was stopped early after a planned interim analysis on the recommendation of the data and safety monitoring committee. At that time, 4401 patients had undergone randomization, with a median follow-up of 2.62 years. The relative risk of the primary outcome was 30% lower in the canagliflozin group than in the placebo group, with event rates of 43.2 and 61.2 per 1000 patient-years, respectively (hazard ratio, 0.70; 95% confidence interval [CI], 0.59 to 0.82; P=0.00001). The relative risk of the renal-specific composite of end-stage kidney disease, a doubling of the creatinine level, or death from renal causes was lower by 34% (hazard ratio, 0.66; 95% CI, 0.53 to 0.81; P<0.001), and the relative risk of end-stage kidney disease was lower by 32% (hazard ratio, 0.68; 95% CI, 0.54 to 0.86; P=0.002). The canagliflozin group also had a lower risk of cardiovascular death, myocardial infarction, or stroke (hazard ratio, 0.80; 95% CI, 0.67 to 0.95; P=0.01) and hospitalization for heart failure (hazard ratio, 0.61; 95% CI, 0.47 to 0.80; P<0.001). There were no significant differences in rates of amputation or fracture. CONCLUSIONS In patients with type 2 diabetes and kidney disease, the risk of kidney failure and cardiovascular events was lower in the canagliflozin group than in the placebo group at a median follow-up of 2.62 years

Development of eStudent iOS mobile application

Abstract— iOS is the Apple mobile operating system, for Apple mobile devices. Initially developed for iPhone, and later for iPod Touch, iPad, AppleTV. The Metropolitan University has a Web application titled eStudent, which enables students by Web to get information about their marks for all subjects, their financies, exam scheduling, professors and assistents, and send exam registration and feedback about teaching, etc. This paper explains the development of the mobile application eStudent on the iOS platform. This application enables students whenever they want, by using their iPhone mobile phone, to get access to the information from the eStudent Web application, and to present it on their iPhone User Interface (UI). This paper explains in details software requirements analysis, system architecture, system modelling, and UI of the eStudent iOS mobile application

Some negative chemical properties of acid soils

Some important chemical properties of various samples of two types of acid soil from Western Serbia (pseudogley and brown forest) are presented in this paper. Mobile Al was found in elevated and toxic quantities (10–30 mg/100 g) in the more acid samples of pseudogley soil. All samples of brown forest soil were very acid and the quantities of mobile Al were in the range from 12.8 to 90.0 mg/100 g. In a selected number of pseudogley soils, the influence of pH and other soil properties on the mineralization and nitrification processes was investigated. Strong inhibition of nitrification at low soil pH was found to be related to high quantities of mobile Al. At pH values less than 4.0 (in 1 M KCl), processes of chemical nitrification and denitrification of applied nitrites were registered in the pseudogley soils.Istraživanja su obavljena na dva tipa zemljišta Zapadne Srbije (pseudoglej i smeđe šumsko zemljište). Oba ispitivana zemljišta karakteriše niska pH vrednost. Kod svih uzoraka smeđeg šumskog zemljišta utvrđene su toksične količine mobilnog Al za biljke i za mikroorganizme, a kod pseudoglejnog zemljišta toksične količine Al su utvrđene samo za neke uzorke. Na proces nitrifikacije, koji je praćen u odabranim uzorcima pseudogleja, direktno su delovali niska pH vrednost (kiselost) i visok sadržaj mobilnog aluminijuma. Dodavanjem NaNO2 utvrđeno je odvijanje procesa hemijske nitrifikacije i denitrfikacije u pseudoglejnom zemljištu pri pH manjem od 4,0 u 1M KCl

Some negative chemical properties of acid soils

Some important chemical properties of various samples of two types of acid soil fromWestern Serbia (pseudogley and brown forest) are presented in this paper.Mobile Al was found in elevated and toxic quantities (10–30 mg/100 g) in the more acid samples of pseudogley soil. All samples of brown forest soil were very acid and the quantities ofmobile Al were in the range from 12.8 to 90.0mg/100 g. In a selected number of pseudogley soils, the influence of pH and other soil properties on the mineralization and nitrification processeswas investigated. Strong inhibition of nitrification at low soil pH was found to be related to high quantities of mobile Al. At pH values less than 4.0 (in 1 M KCl), processes of chemical nitrification and denitrification of applied nitrites were registered in the pseudogley soils