Understanding the time-driven shifts of vaccine effectiveness against any and severe COVID-19 before and after the surge of Omicron variants within 2.5 years of vaccination: A meta-regression

OBJECTIVES

The COVID-19 pandemic required rapid development of vaccines within a short period of time which did not allow to assess vaccine effectiveness (VE) in the long-term.

METHODS

A computerized literature search was undertaken to identify eligible studies, with no language restrictions, published between 1 December 2020 and 30 June 2023.

RESULTS

Out of a total of 27,597 publications, 761 studies were included. Early VE of 87.2% decreased to 55.1% after 9 months among populations fully immunized not only with mRNA (proxy mRNA) vaccines, and 66.3% decreased to 23.5% in populations immunized exclusively with non-mRNA vaccines. Protection against severe COVID-19 declined to 80.9% for proxy mRNA vaccines and 67.2% for non-mRNA vaccines. Omicron variants significantly diminished VE. Within 6-8 months of receiving a single booster of an mRNA vaccine, VE declined to 14.0% and 67.7% for any and severe COVID-19, respectively. Multiple mRNA booster doses restored protection that declined to 29.5% and 70.6% for any and severe COVID-19, respectively, within 5-7 months.

CONCLUSION

Outcomes of this meta-regression underscore the evolving nature of COVID-19 in response to vaccination, dosing schedules, and emerging variants, and provide crucial insights for public health interventions and vaccination strategies.

The Efficacy of Fibrin Sealant in Sutureless Deep Sclerectomy - Preliminary Outcomes

PRCIS

Deep sclerectomy with fibrin adhesive can constitute a safe alternative to the classic procedure using sutures, providing non-allergenic, non-toxic and secure adhesion with no sign of aqueous humor outflow obstruction postoperatively.

PURPOSE

To evaluate short- and medium-term postoperative results of deep sclerectomy (DS) with a fibrin sealant.

PATIENTS AND METHODS

This prospective, noncomparative, interventional case-series involves 12 eyes of 12 patients with uncontrolled open-angle glaucoma (OAG) who underwent DS with Esnoper (Clip or V2000) implant between February 2021 and March 2022. A novel method of wound closure (sclera, Tenon´s fascia and conjunctiva) employing fibrin glue was used instead of classic sutures. Surgical outcomes assessed include: intraocular pressure (IOP) and glaucoma therapy (GT) reduction, best-corrected visual acuity (BCVA) changes and number of complications registered peri- and postoperatively. All measurements were performed preoperatively, as well as at 1 day, at 1 and 2 weeks, and at 1, 2, 3, 6, 9 and 12 months after surgery.

RESULTS

The mean IOP decreased from 24.0±9.1 mmHg to 13.8±6.3 mmHg at one year postoperatively (P<0.001). Kaplan-Meier survival analysis revealed complete and qualified success rates of 83.3% and 91.7%. The mean GT decreased from 3.2±1.1 to 0.8±1.3 drugs 12 months after surgery (P<0.001). Nd:YAG goniopunture was performed in 2 eyes at 1 and 12 months postoperatively. No significant BCVA changes were registered. Perioperatively, we noted a trabeculo-descemet microperforation in one eye, transient hypotony in 5 eyes and mild hyphema in 2 eyes.

CONCLUSIONS

Fibrin adhesive provided an effective closure in sutureless DS in the patients included in our study. This modification of classical DS may simplify the surgical technique, ensure secure wound adaptation, optimize healing, and lower the risk of inflammation and fibrosis postoperatively.

Timing of HPV vaccination as adjuvant treatment of CIN2+ recurrence in women undergoing surgical excision: a meta-analysis and meta-regression

OBJECTIVE

The main aim was to determine the overall vaccine effectiveness (VE) against recurrent cervical intraepithelial neoplasia grade 2 or worse (CIN2+) including specific VE associated with timing of human papillomavirus (HPV) vaccination using data from published studies.

DESIGN

Meta-analysis and meta-regression.

DATA SOURCES

A computerised literature search was undertaken using the MEDLINE, EMBASE, International Pharmaceutical Abstracts, Derwent Drug File, ProQuest Science and Technology, Cochrane and MedRxiv databases. To be eligible, the studies, with no language restrictions, had to be published between 1 January 2001 and 25 May 2023.

REVIEW METHODS

Included were studies with an unvaccinated reference group that assessed CIN2+ recurrence irrespective of the HPV genotype in women undergoing conisation provided. The present study was carried out in compliance with the Preferred Reporting Items for Systematic Review and Meta-Analyses and Meta-analysis Of Observational Studies in Epidemiology guidelines. The risk of study bias was assessed using the Newcastle-Ottawa Quality Assessment Scale. The Grading of Recommendations Assessment, Development, and Evaluation guidelines were used to assess the strength of evidence for the primary outcome. Data synthesis was conducted using meta-analysis and meta-regression.

RESULTS

Out of a total of 14 322 publications, 20 studies with a total of 21 estimates were included. The overall VE against recurrent CIN2+ irrespective of the HPV genotype achieved 69.5% (95% CI: 54.7% to 79.5%). While the HPV vaccine valency, follow-up duration, type of study including its risk of bias had no effect on VE, the highest VE of 78.1% (95% CI: 68.7% to 84.7%) was reported for women receiving their first dose not earlier than the day of excision. This outcome was supported by additional analyses and a VE prediction interval ranging from 67.1% to 85.4%.

CONCLUSIONS

The outcome of this meta-analysis and meta-regression convincingly showed the beneficial effect of post-excisional HPV vaccination against CIN2+ recurrence. Studies published to date have been unable to determine whether or not vaccination, completed or initiated before conisation, would be associated with more favourable results.

PROSPERO REGISTRATION NUMBER

CRD42022353530.

Efficacy and Safety of Deep Sclerectomy With the Esnoper Clip Implant for Uncontrolled Primary Open Angle Glaucoma: A 1 Year Prospective Study

PRCIS

Deep sclerectomy (DS) with the Esnoper Clip drainage implant in patients with uncontrolled primary open angle glaucoma (POAG) achieved a complete success rate of 87.2% at the 1-year follow-up.

PURPOSE

To investigate the efficacy and safety of DS followed by Esnoper Clip implantation in patients with uncontrolled POAG.

MATERIALS AND METHODS

In a prospective, consecutive, interventional study, we investigated 39 eyes of 35 patients with uncontrolled POAG who underwent DS with Esnoper Clip implantation. Complete ophthalmologic examinations including corrected visual acuity and intraocular pressure (IOP), were performed preoperatively, and at 1 day, at 1 week as well as at 1, 3, 6, 9, and 12 months postoperatively. Moreover, any goniopunctures and glaucoma medications required postoperatively were noted.

RESULTS

The mean preoperative IOP was 20.8±5.2 mm Hg and it decreased to 13.9±3.1 mm Hg at 1 year postoperatively ( P <0.001). The number of glaucoma medications decreased from 2.9±0.7 preoperatively to 0.3±0.8 after 1 year ( P <0.001). The complete success rate (IOP≤21 mm Hg without glaucoma medication) and the qualified success rate (IOP ≤21 mm Hg with or without glaucoma medication) were 87.2% and 94.9%, respectively. Goniopuncture was performed in 33.3% of cases. No significant corrected visual acuity changes were registered at the final follow-up. Perioperative complications consisted of 3 micro-perforations of the trabeculo-descemet membrane. Postoperative complications included: hyphema (6 eyes), hypotony (6 eyes), shallow anterior chamber (3 eyes), choroidal detachment (4 eyes)-all of which were resolved without surgical intervention during the first postoperative month-and conjunctival dehiscence, which required resuture (2 eyes).

CONCLUSION

Deep sclerectomy with the Esnoper Clip implant was safe and effectively lowered IOP in patients with uncontrolled POAG.

Low-cost and prototype-friendly method for biocompatible encapsulation of implantable electronics with epoxy overmolding, hermetic feedthroughs and P3HT coating

The research of novel implantable medical devices is one of the most attractive, yet complex areas in the biomedical field. The design and development of sufficiently small devices working in an in vivo environment is challenging but successful encapsulation of such devices is even more so. Industry-standard methods using glass and titanium are too expensive and tedious, and epoxy or silicone encapsulation is prone to water ingress with cable feedthroughs being the most frequent point of failure. This paper describes a universal and straightforward method for reliable encapsulation of circuit boards that achieves ISO10993 compliance. A two-part PVDF mold was machined using a conventional 3-axis machining center. Then, the circuit board with a hermetic feedthrough was placed in the mold and epoxy resin was injected into the mold under pressure to fill the cavity. Finally, the biocompatibility was further enhanced with an inert P3HT polymer coating which can be easily formulated into an ink. The biocompatibility of the encapsulants was assessed according to ISO10993. The endurance of the presented solution compared to silicone potting and epoxy potting was assessed by submersion in phosphate-buffered saline solution at 37 °C. The proposed method showed superior results to PDMS and simple epoxy potting.

Risk factors affecting COVID-19 vaccine effectiveness identified from 290 cross-country observational studies until February 2022: a meta-analysis and meta-regression

BACKGROUND

Observational studies made it possible to assess the impact of risk factors on the long-term effectiveness of mRNA and adenoviral vector (AdV) vaccines against COVID-19.

METHODS

A computerized literature search was undertaken using the MEDLINE, EMBASE, and MedRxiv databases to identify eligible studies, with no language restrictions, published up to 28 February 2022. Eligible were observational studies assessing vaccine effectiveness (VE) by disease severity with reference groups of unvaccinated participants or participants immunized with one, two, or three vaccine doses. Our study was carried out in compliance with the PRISMA and MOOSE guidelines. The risk of study bias was identified using the Newcastle-Ottawa Quality Assessment Scale. The GRADE guidelines were applied to assess the strength of evidence for the primary outcome. The synthesis was conducted using a meta-analysis and meta-regression.

RESULTS

Out of a total of 14,155 publications, 290 studies were included. Early VE of full vaccination against COVID-19 of any symptomatology and severity decreased from 96% (95% CI, 95-96%) for mRNA and from 86% (95% CI, 83-89%) for AdV vaccines to 67% for both vaccine types in the last 2 months of 2021. A similar 1-year decline from 98 to 86% was found for severe COVID-19 after full immunization with mRNA, but not with AdV vaccines providing persistent 82-87% effectiveness. Variant-reduced VE was only associated with Omicron regardless of disease severity, vaccine type, or vaccination completeness. The level of protection was reduced in participants aged >65 years, with a comorbidity or those in long-term care or residential homes independently of the number of doses received. The booster effect of the third mRNA dose was unclear because incompletely restored effectiveness, regardless of disease severity, declined within a short-term interval of 4 months.

CONCLUSIONS

Full vaccination provided an early high, yet waning level of protection against COVID-19 of any severity with a strong impact on the high-risk population. Moreover, the potential risk of new antigenically distinct variants should not be underestimated, and any future immunization strategy should include variant-updated vaccines.

The Preparation and Biological Testing of Novel Wound Dressings with an Encapsulated Antibacterial and Antioxidant Substance

Chronic wounds represent a significant socio-economic problem, and the improvement of their healing is therefore an essential issue. This paper describes the preparation and biological properties of a novel functionalized nanofiber wound dressing consisting of a polycaprolactone nanofiber carrier modified by a drug delivery system, based on the lipid particles formed by 1-tetradecanol and encapsulated gentamicin and tocopherol acetate. The cytotoxicity of extracts was tested using a metabolic activity assay, and the antibacterial properties of the extracts were tested in vitro on the bacterial strains Staphylococcus aureus and Pseudomonas aeruginosa. The effect of the wound dressing on chronic wound healing was subsequently tested using a mouse model. Fourteen days after surgery, the groups treated by the examined wound cover showed a lower granulation, reepithelization, and inflammation score compared to both the uninfected groups, a lower dermis organization compared to the control, a higher scar thickness compared to the other groups, and a higher thickness of hypodermis and bacteria score compared to both the uninfected groups. This work demonstrates the basic parameters of the safety (biocompatibility) and performance (effect on healing) of the dressing as a medical device and indicates the feasibility of the concept of its preparation in outpatient conditions using a suitable functionalization device.

Pencil-beam scanning proton therapy for the treatment of glomus jugulare tumours

INTRODUCTION

Glomus jugulare tumours (GJT) are benign tumours that arise locally and destructively in the base of the skull and can be successfully treated with radiotherapy. Patients have a long-life expectancy and the late effects of radiotherapy can be serious. Proton radiotherapy reduces doses to critical organs and can reduce late side effects of radiotherapy. The aim of this study was to report feasibility and early clinical results of 12 patients treated using proton therapy.

METHODS

Between December 2013 and June 2019, 12 patients (pts) with GJT (median volume 20.4 cm³ ; range 8.5-41 cm³ ) were treated with intensity modulated proton therapy (IMPT). Median dose was 54 GyE (Gray Equivalents) (50-60 GyE) with daily fractions of 2 GyE. Twelve patients were analysed with a median follow-up time of 42.2 months (11.3-86.7). Feasibility, dosimetric parameters, acute and late toxicity and local effect on tumour were evaluated in this retrospective study.

RESULTS

All patients finished treatment without interruption, with excellent dosimetric parameters and mild acute toxicity. Stabilisation of tumour size was detected on MRI in all patients. No changes in symptoms were observed in comparison with pre-treatment conditions. No late effects of radiotherapy were observed.

CONCLUSION

Pencil-beam scanning proton radiotherapy is highly feasible in the treatment of large GJT with mild acute toxicity and promising short-term results. Longer follow-up and larger patient cohorts are required to further identify the role of pencil-beam scanning (PBS) for this indication.

Visual neuroprosthesis: present and possible perspectives

The purpose of this study is to provide an overview of the replacements used in lost vision in the form of the bionic eye, to show their deficiencies and outline other possibilities for non-invasive stimulation of functional areas of the visual cortex. The review highlights the damage not only to the primary altered cellular structures, but also to all other horizontally and vertically localised structures. Based on the results of a large number of functional magnetic resonance imaging and electrophysiological methods, the authors focus on the pathology of the entire visual pathway in pigmentary retinopathy (PR) and age-related macular degeneration (AMD). This study provides a recent overview of the possible systems used to replace lost vision. These range from stimulation with intraocular implants, through stimulation of the optic nerve and lateral geniculate nucleus to the visual cortex. The second part deals with the design of image processing technology and its transformation into the form of transcranial stimulation of undamaged parts of the brain, which is protected by a patent. This is comprehensive overview of the current possibilities of replacement of lost vision and a proposal for a new non-invasive methods of stimulation of functional neurons of the visual cortex.

Pencil Beam Scanning (PBS) Intensity-Modulated Proton Therapy (IMPT) Chemoradiotherapy for Anal Canal Cancer-Single Institution Experience

Simple Summary

Eligible patients received PBS IMPT at a single institution. Treatment was administered in two volumes: 1—tumour with margins plus involved lymph nodes; 2—regional lymph node groups: perirectal (mesorectal), obturatory, inguinal, internal, external, and common iliac. The total doses of 57.5 GyE and 45 GyE, respectively, were administered in volumes 1 and 2 in 25 fractions, 5 fractions per week, respectively (a simultaneous integrated boost). Concomitant chemotherapy cisplatinum (CDDP) plus 5-FU or CDDP plus capecitabine was administered as per protocol. This single-institution study showed the high efficacy of PBS IMPT, achieving a high rate of complete regression. The 2-year overall survival, relapse-free survival and colostomy-free survival were 94.2, 93.8 and 91.0%, respectively. The haematological acute toxicity of grade 3–4 remained low. The acute toxicity completely resolved in all patients and had no lethal outcomes.

Abstract

Background: A favourable dose distribution has been described for proton beam therapy (PBT) of anal cancer in dosimetric studies. The relationship between dosimetric parameters in bone marrow and haematologic toxicity, treatment interruptions, and treatment efficacy has also been documented. There are only few references on clinical results of PBT for anal cancer. The primary objective of the retrospective study was to assess the efficacy of pencil beam scanning intensity-modulated proton therapy (PBS IMPT) in the definitive chemoradiotherapy of anal cancer. Secondary objectives were established to identify the risks of acute chronic toxicity risks and to assess colostomy rates. Materials and methods: Patients were treated for biopsy-proven squamous cell cancer (SCC) of the anus at initial or advanced stages. Eligible patients received PBS IMPT at a single institution. Treatment was administered in two volumes: 1—tumour with margins plus involved lymph nodes; 2—regional lymph node groups: perirectal (mesorectal), obturatory, inguinal, internal, external, and common iliac. The total doses of 57.5 GyE and 45 GyE, respectively, were administered in volumes 1 and 2 in 25 fractions, 5 fractions per week, respectively (a simultaneous integrated boost). Concomitant chemotherapy cisplatinum (CDDP) plus 5-FU or CDDP plus capecitabine was administered as per protocol. The treatment effect was assessed using DRE (digital rectal examination) and MRI (magnetic resonance imaging) within the follow-up period. Toxicity was scaled using CTCAE version 4.0 criteria. Results: 39 of 41 patients treated during the period of February 2014–August 2021 were eligible for analysis. All patients completed treatment, 76.9% without interruption. The median treatment time was 35 days (32–35). The median follow-up period was 30 months, 34 patients are alive to-date, 5 patients died prior to the date of analysis, and 2 deaths were unrelated to the primary disease. The 2-year overall survival, relapse-free survival, and colostomy-free survival were 94.2%, 93.8%, and 91.0%, respectively. Complete regression was achieved in 36 patients (92.3%), partial regression was achieved in 2 (5.1%), and immediate progression at end of treatment occurred in 1 patient (2.6%). Salvage resection was indicated for two patients in partial regression and due to severe chronic dermatologic toxicity. The grade 3 and 4 haematological toxicity rates were 7.7% and 5.1%, respectively. The most frequent non-haematological acute toxicities of grade 3–4 observed were dermatitis (23.1%), diarrhoea (7.7%), and dehydration (7.7%). Chronic toxicity emerged predominantly as skin atrophy/ulceration grade 2 (26.5%) and grade 3–4 (5.8%), and radiation proctitis grade 2 (38.2%) and grade 3 (2.9%). Discussion, conclusions: This single-institution study showed the high efficacy of PBS IMPT, achieving a high rate of complete regression. The haematological acute toxicity of grade 3–4 remained low; however, the impact of altered chemotherapy (CDDP instead of mitomycin C) remains unclear. The incidence of other acute toxicities shares similarity with photon therapy investigated in large studies. The acute toxicity completely resolved in all patients, had no lethal outcomes, and never resulted in the necessity for colostomy. By contrast, it was chronic toxicity, skin ulceration, perirectal fistulation, and fibrosis that resulted in salvage surgery and/or the need for a colostomy. A challenging question remains: to what extent can PBT prevent chronic toxicity? Longer follow-up remains necessary.

Construction of a Wireless-Enabled Endoscopically Implantable Sensor for pH Monitoring with Zero-Bias Schottky Diode-based Receiver

Ambulatory pH monitoring of pathological reflux is an opportunity to observe the relationship between symptoms and exposure of the esophagus to acidic or non-acidic refluxate. This paper describes a method for the development, manufacturing, and implantation of a miniature wireless-enabled pH sensor. The sensor is designed to be implanted endoscopically with a single hemostatic clip. A fully passive rectenna-based receiver based on a zero-bias Schottky diode is also constructed and tested. To construct the device, a two-layer printed circuit board and off-the-shelf components were used. A miniature microcontroller with integrated analog peripherals is used as an analog front end for the ion-sensitive field-effect transistor (ISFET) sensor and to generate a digital signal which is transmitted with an amplitude shift keying transmitter chip. The device is powered by two primary alkaline cells. The implantable device has a total volume of 0.6 cm³ and a weight of 1.2 grams, and its performance was verified in an ex vivo model (porcine esophagus and stomach). Next, a small footprint passive rectenna-based receiver which can be easily integrated either into an external receiver or the implantable neurostimulator, was constructed and proven to receive the RF signal from the implant when in proximity (20 cm) to it. The small size of the sensor provides continuous pH monitoring with minimal obstruction of the esophagus. The sensor could be used in routine clinical practice for 24/96 h esophageal pH monitoring without the need to insert a nasal catheter. The "zero-power" nature of the receiver also enables the use of the sensor for automatic in-vivo calibration of miniature lower esophageal sphincter neurostimulation devices. An active sensor-based control enables the development of advanced algorithms to minimize the used energy to achieve a desirable clinical outcome. One of the examples of such an algorithm would be a closed-loop system for on-demand neurostimulation therapy of gastroesophageal reflux disease (GERD).

Ultrahypofractionated Proton Radiation Therapy in the Treatment of Low and Intermediate-Risk Prostate Cancer-5-Year Outcomes

PURPOSE

To analyze the 5-year biochemical disease-free survival (bDFS) and late toxicity profile in patients with prostate cancer treated with pencil beam scanning (PBS) proton radiation therapy.

METHODS AND MATERIALS

Between January 2013 and March 2016, 284 patients with prostate cancer were treated using intensity modulated proton therapy (IMPT), with an ultrahypofractionated schedule (36.25 GyE in 5 fractions). Five patients were immediately lost from follow-up and thus were excluded from analysis. Data for 279 patients were prospectively collected and analyzed with a median follow-up time of 56.5 (range, 3.4-87.5) months. The mean age at time of treatment was 64.5 (40.1-85.7) years, and the median prostate-specific antigen (PSA) value was 6.35 μg/L (0.67-17.3 μg/L). A total of 121 (43.4%) patients had low-risk, 125 patients (44.8%) had favorable, and 33 (11.8%) unfavorable intermediate-risk cancer. In addition, 49 (17.6%) patients underwent neoadjuvant hormonal therapy, and no patients had adjuvant hormonal therapy. bDFS and late toxicity profiles were evaluated.

RESULTS

The median treatment time was 9 days (range, 7-18 days). The 5-year bDFS was 96.9%, 91.7%, and 83.5% for the low-, favorable, and unfavorable intermediate-risk group, respectively. Late toxicity (Common Terminology Criteria for Adverse Events v.4) was as follows: gastrointestinal: grade 1, 62 patients (22%), grade 2, 20 patients (7.2%), and grade 3, 1 patient (0.36%); genitourinary: grade 1, 80 patients (28.7%), grade 2, 14 patients (5%), and grade 3, 0 patients. PSA relapse was observed in 17 patients (6.1%), and lymph node or bone recurrence was detected in 11 patients. Four (1.4%) local recurrences were detected. Nine patients (3.2%) died of causes unrelated to prostate cancer. No deaths related to prostate cancer were reported.

CONCLUSION

Ultrahypofractionated proton beam radiation therapy for prostate cancer is effective with long-term bDFS comparable with other fractionation schedules and with minimal serious long-term GI and GU toxicity.

Treatments for enhancing the biocompatibility of titanium implants

Titanium surface treatment is a crucial process for achieving sufficient osseointegration of an implant into the bone. If the implant does not heal sufficiently, serious complications may occur, e.g. infection, inflammation, aseptic loosening of the implant, or the stress-shielding effect, as a result of which the implant may need to be reoperated. After a titanium graft has been implanted, several interactions are crucial in order to create a strong bone-implant connection. It is essential that cells adhere to the surface of the implant. Surface roughness has a significant influence on cell adhesion, and also on improving and accelerating osseointegration. Other highly important factors are biocompatibility and resistance to bacterial contamination. Bio-inertness of titanium is ensured by the protective film of titanium oxides that forms spontaneously on its surface. This film prevents the penetration of metal compounds, and it is well-adhesive for calcium and phosphate ions, which are necessary for the formation of the mineralized bone structure. Since the presence of the film alone is not sufficient for the biocompatibility of titanium, a suitable surface finish is required to create a firm bone-implant connection. In this review, we explain and compare the most widely-used methods for modulating the surface roughness of titanium implants in order to enhance cell adhesion on the surface of the implant, e.g. plasma spraying, sandblasting, acid etching, laser treatment, sol-gel etc., The methods are divided into three overlapping groups, according to the type of modification.

LOW DOSE BATH FROM IMPT VS. IMXT FOR THE PELVIC AREA WHEN TREATING ADVANCED PROSTATE CANCER

Twenty (10 intensity-modulated proton therapy (IMPT) and 10 intensity-modulated x-ray therapy (IMXT) treatment plans for patients with advanced prostate carcinoma were compared in this study. All chosen patients were indicated for prostate and pelvic lymph nodes irradiation using simultaneous integrated boost technique. These patients represent typical specimen for this diagnose. IMPT irradiates just half of the tissue volume with a low dose (up to 10 cobalt gray equivalent) compared to IMXT without compromise in target volumes coverage and in this way reduces the risk of secondary cancer development or other possible complications.

Extreme hypofractionated proton radiotherapy for prostate cancer using pencil beam scanning: Dosimetry, acute toxicity and preliminary results

INTRODUCTION

Extreme hypofractionated radiotherapy for prostate cancer is a common modality in photon therapy. Pencil beam scanning (PBS) in similar fractionation allows better dose distribution and makes proton therapy more available for such patients. The purpose of this study is the feasibility of extreme proton hypofractionated radiotherapy and publication of early clinical results.

METHODS

Two hundred patients with early-stage prostate cancer were treated with IMPT (intensity-modulated proton therapy), extreme hypofractionated schedule (36.25 GyE in five fractions) between February 2013 and December 2015. Mean age of the patients was 64.3 years, and the mean value of prostate-specific antigen (PSA) before treatment was 6.83 μg/L (0.6-17.3 μg/L). Ninety-three patients (46.5%) were in the low-risk group. One hundred and seven patients (53.5%) were in the intermediate-risk group. Twenty-nine patients (14.5%) had neoadjuvant hormonal therapy, and no patients had adjuvant hormonal therapy. Acute toxicity, late toxicity and short-term results were evaluated.

RESULTS

All patients finished radiotherapy without interruptions. The median follow-up time was 36 months. The mean treatment time was 9.5 days (median 9 days). Acute toxicity according to Common Terminology Criteria for Adverse Events (CTCAE) v 4.0 was (gastrointestinal toxicity) GI (grade) G1-17%, G2-3.5%; (genitourinary toxicity) GU G1-40%, G2-19%; and no G3 toxicity was observed. Late toxicity was GI G1-19%, G2-5.5%; GU G1-17%, G2-4%; and no G3 toxicity was observed. PSA relapse was observed in one patient (1.08%) in the low-risk group (pelvic lymph node involvement was detected) and in seven patients (6.5%) in the intermediate-risk group (three lymph node metastases, two lymph node and bone metastases, two PSA relapses). No patient died of prostate cancer, and three patients died from other reasons. No local recurrence of cancer in the prostate was observed.

CONCLUSIONS

Proton beam radiotherapy for prostate cancer is feasible with a low rate of acute toxicity and promising late toxicity and effectivity.

The role of immune cell subpopulations in the growth and rejection of TC-1/A9 tumors in novel mouse strains differing in the H2-D haplotype and NKC domain

The present study aimed to elucidate the role of cluster of differentiation (CD)8+, CD4+, natural killer (NK), and myeloid (CD11b+) cells in the course of the growth and rejection of experimental major histocompatibility complex (MHC) class I-deficient, HPV16 E6/E7-associated TC-1/A9 tumors in mice. Stable mouse lines (F₃₀) generated by inbreeding of Balb/c and C57BL/6 strains, which were characterized by H-2Db+d-NK1.1neg (B6-neg) and H-2Db-d+NK1.1high (Balb-high) phenotypes, were used for the present study. The novel strains spontaneously regressed tumors in 70–90% of cases. Ex vivo histological analysis of the tumor microenvironment in cryosections showed an indirect correlation between the growth of the transplanted tumor (progressor vs. regressor mice) and the proportion of immunocompetent cell infiltration in the tumors. The regressor mice exhibited a higher infiltration of tumors with CD4+ and CD8+ cells, and in Balb-high with NK cells as well, compared with the progressors. All tumor transplants also indicated a huge infiltration of CD11b+ cells, but this infiltration was not dependent on the stage of the TC-1/A9 tumor development. Depletion of individual cell subpopulations in vivo exhibited different effects on the tumor development in the two strains. Elimination of CD8-positive cells enhanced growth of TC-1/A9 tumor transplants in both hybrid stains, whereas CD4+ cell depletion affected rejection of TC-1/A9 tumors in the B6-neg mice only. Depletion of NK cells with anti-asialo GM1 antibody in the Balb-high strain led to enhancement of tumor growth, which was more pronounced after depletion of the NK1.1+ subpopulation. On the other hand, depletion of NK cells with anti-asialo GM1 in B6-neg mice did not affect the regression of TC-1/A9 tumor transplants, but increased the CD11b+ cell infiltration. In summary, these results indicate that co-operation of particular subsets of immunocompetent cells is essential for the rejection of TC-1/A9 tumor transplants. In B6-neg mice, the co-operative action of CD8+ and CD4+ cells is required, whereas in Balb-high mice, the synergy of CD8+ and NK1.1+ cells is of major importance.

Expression of selected proteins in breast cancer brain metastases

The aim of the study was to assess the immunohistochemical (IHC) profiles of SRC3, Pax2, ER, PgR, Her2, EGFR, CK5/6, and Ki67 proteins in breast-cancer brain metastasis. The study utilized tumor samples from 30 metastatic patients and calculated correlations between all IHC variables. In fourteen cases, primary breast cancers paired with secondary deposits were analyzed. We evaluated the association between IHC status in the primary and secondary deposits, grade, and histotype of the tumors. The examination of the metastatic deposits in all 30 patients resulted in positive detection in the following cases: SRC3 in 20 cases (66.6%), Pax2 in 22 (73.3%), ER in 22 (73.3%), PgR in 25 (83.3%), Her2 in 10 (33.3%), EGFR in 12 (40%), CK5/6 in 7 (23.3%), and Ki67 in 23 (76.6%). Grade 2 was found in 13.3% of all patients, and grade 3 in 86.7%. SRC3 and Pax2 were positive in both G2 and G3. Invasive lobular carcinoma and invasive ductal carcinoma were diagnosed in 23.3% and 76.7% of cases, respectively. There were no differences between the IHC expression of the studied proteins in either grading or histotype of the tumors. In the IHC profiles, which included SRC3, Pax2, ER, PgR, Her2, CK5/6, Ki67, and EGFR, we found no statistically significant differences between the primary cancer and the brain metastasis. In our study of metastatic breast carcinoma deposits, there was no correlation between SRC3, Pax2 status and histotype, and tumor grade. The IHC status of the paired primary and metastatic deposits did not differ in a statistically significant manner.

¹³C-methacetin breath test in the evaluation of disease severity in patients with liver cirrhosis

AIMS

The non-invasive (13)C-methacetin ((13)C-MBT) breath test has been proposed as a measure of metabolic liver function that improves the diagnostic efficacy of serologic and biochemical tests in assessing hepatic functional capacity and liver disease severity, The goal of this study was to establish the clinical utility of this test in quantifying hepatic metabolic function in patients with liver cirrhosis of varying severity and to compare (13)C-MBT measurements with the AST/ALT ratio, APRI score, and other routine liver tests.

METHODS

Routine liver function tests including serum bilirubin, aspartate aminotransferase activity (AST), alanine aminotransferase (ALT), AST/ALT ratio, the APRI score, the percentage of dose rate (PDR) and cumulative percentage of dose rate (CPDR) of the (13)C-MBT were evaluated in 52 cirrhotic patients of alcohol etiology (Child-Pugh A/B/C 10/28/14) and 37 healthy controls.

RESULTS

The (13)C-MBT differed significantly between healthy controls and cirrhotic patients at all time intervals measured. It also proved the ability to differentiate patients with liver cirrhosis based on severity of hepatic impairment corresponding to the Child-Pugh classification A vs. B vs. C. The ROC curve analysis suggested that the best prediction is provided by time intervals between the 10th - 20th or 10th - 40th minute of PDR.

CONCLUSIONS

The (13)C-MBT offers a reliable means for quantification of hepatic metabolic function over the complete range of functional liver impairment. It is non-invasive, easy to perform and completely safe.

Micronuclei in lymphocytes from currently active uranium miners

Micronuclei can be used as markers of past radiation exposure, but only few studies have dealt with uranium miners. In this paper, we report on micronuclei in lymphocytes from individuals currently working at Rožná, Czech Republic, the last functioning uranium mine in the European Union. A modified micronucleus-centromere test was applied to assess the occurrence of micronuclei in stimulated lymphocytes, as well as their content in terms of whole chromosomes or fragments. Compared with unexposed individuals, the miners had higher frequencies of micronucleus-containing lymphocytes and higher percentages of micronuclei without centromeres, and the differences were significant for both parameters (0.74 ± 0.60 vs. 0.50 ± 0.42, p = 0.017 and 49 ± 44 vs. 12 ± 21, p = 0.0002; means ± standard deviations). There were also significant correlations between one or other of these parameters on the one hand and various dose values on the other, in particular with a 'retrievable' dose, that is, a dose whose effect should still be recognisable in lymphocytes assuming a half-life of 3 years. The 'retrievable' dose at which a doubling of the micronucleus frequency was observed was around 35 mSv, corresponding to a total dose of 90 mSv received while working in the mines. Altogether, our data show that the micronucleus-centromere test is a valuable tool for the assessment of past radiation exposure in uranium miners. The scatter in the data is of course far too great to allow individual dosimetry, but for groups of a few dozen exposed individuals, the method can be used to monitor doses clearly below 100 mSv.

Incidence of cutaneous malignant melanoma in the Czech Republic: the risks of sun exposure for adolescents

The Czech Republic reported one of the highest incidence rate in cutaneous melanoma (CM) in Europe and because this incidence has been increasing, mainly among young people, the main goal of our study was to establish sun exposure behavior risk factors for CM formation and to evaluate whether the young generation of Czechs is exposed to a higher risk of CM than the older generation. A questionnaire-based case-control study was conducted. We obtained 978 completed questionnaires: 216 from patients with CM and 762 from healthy respondents. The healthy individuals were further divided to adolescents (n = 460) and older respondents (n = 302). Three logistic regression models were developed: 1. patients with CM vs. healthy older respondents, 2. adolescents vs. healthy older respondents, and 3. patients with CM vs. adolescents. The main risk factors for all three models were the number of sunburn episodes and the use of the sunscreen in the childhood. The most alarming results for adolescents included: all day sun exposure, including times of maximum risk (11 AM to 3 PM), inadequate use of sunscreen in adulthood, and frequent mountain holidays. Our results show that sun-safety in the young generation is satisfactory, when the responsibility for sun exposure behavior is in the hands of their parents; however, when children become adolescents, they become immune to sun-safety and risk prevention campaigns and their behavior becomes much more risky. Our results further suggest the sun-safety campaigns need to be modified in such a way as to have greater impact and influence on adolescent sun-risk behaviors.

Persistence of genetic damage in lymphocytes from former uranium miners

Lymphocytes from former uranium miners who finished work underground one or more decades ago were analysed with respect to possibly persisting genetic damage induced by their radiation exposure. A modified micronucleus-centromere test was used which determined the frequency of micronucleus-containing binucleate cells after cytochalasin B treatment and the percentage of centromere-free micronuclei, assessed with the help of immunofluorescence labeling of centromere protein B. Whereas the overall frequency of micronucleus-containing cells was not significantly elevated above the level found in a control group, former miners showed a greater percentage of centromere-free micronuclei, i.e. micronuclei containing only acentric fragments. Our results are in excellent agreement with those of an earlier uranium miner study and lend support to the assumption that genetic damage from alpha radiation can persist for many years after exposure, possibly due to genomic instability. The frequency of micronucleus-containing cells, but not the percentage of centromere-free micronuclei, significantly increased with time since last exposure in the mines. This can be attributed, at least in part, to the fact that miners who have finished working underground longer ago tend to be older, and there is an increase of the frequency of micronucleus-containing cells with age.

[Statistics in clinical and experimental medicine]

The paper presents a brief overview of statistical methods used in clinical and experimental medicine, ranging from basic indicators and parameters of descriptive statistics and hypotheses testing (parametric as well as non-parametric methods) to a description of the most frequently used multivariate methods in medical scientific publications, to logistic regression. The paper also describes Principle Component Analysis (PCA), which is one of the methods used to decrease a data dimensionality. The proper use of statistical methods is demonstrated on specific clinical cases.

The evolution of rectal and urinary toxicity and immune response in prostate cancer patients treated with two three-dimensional conformal radiotherapy techniques

Background

Our research compared whole pelvic (WP) and prostate-only (PO) 3-dimensional conformal radiotherapy (3DCRT) techniques in terms of the incidence and evolution of acute and late toxicity of the rectum and urinary bladder, and identified the PTV-parameters influencing these damages and changes in antitumor immune response.

Methods

We analyzed 197 prostate cancer patients undergoing 3DCRT for gastrointestinal (GI) and genitourinary (GU) toxicities, and conducted a pilot immunological study including flow cytometry and an NK cell cytotoxicity assay. Acute and late toxicities were recorded according to the RTOG and the LENT-SOMA scales, respectively. Univariate and multivariate analyses were conducted for factors associated with toxicity.

Results

In the WP group, an increase of acute rectal toxicity was observed. A higher incidence of late GI/GU toxicity appeared in the PO group. Only 18 patients (WP-7.76% and PO-11.11%) suffered severe late GI toxicity, and 26 patients (WP-11.21% and PO-16.05%) severe late GU toxicity. In the majority of acute toxicity suffering patients, the diminution of late GI/GU toxicity to grade 1 or to no toxicity after radiotherapy was observed. The 3DCRT technique itself, patient age, T stage of TNM classification, surgical intervention, and some dose-volume parameters emerged as important factors in the probability of developing acute and late GI/GU toxicity. The proportion and differentiation of NK cells positively correlated during 3DCRT and negatively so after its completion with dose-volumes of the rectum and urinary bladder. T and NKT cells were down-regulated throughout the whole period. We found a negative correlation between leukocyte numbers and bone marrow irradiated by 44-54 Gy and a positive one for NK cell proportion and doses of 5-25 Gy. The acute GU, late GU, and GI toxicities up-regulated the T cell (CTL) numbers and NK cytotoxicity.

Conclusion

Our study demonstrates the association of acute and late damage of the urinary bladder and rectum, with clinical and treatment related factors. The 3DCRT itself does not induce the late GI or GU toxicity and rather reduces the risk of transition from acute to late toxicity. We have described for the first time the correlation between organs at risk, dose-volume parameters, and the immunological profile.

Hydration and transparency of the rabbit cornea irradiated with UVB-doses of 0.25 J/cm(2) and 0.5 J/cm(2) compared with equivalent UVB radiation exposure reaching the human cornea from sunlight

PURPOSE

Exposure of the cornea to UV radiation from sunlight evokes intraocular inflammation, photokeratitis. Photokeratitis is caused by UVB radiation. It is accompanied by changes of corneal hydration and light absorption. The aim of this study was to examine the effect of two UVB doses on corneal optics in rabbits and to compare these UVB doses with the equivalent exposure of UVB radiation reaching the human cornea from sunlight.

MATERIALS AND METHODS

Rabbit corneas were irradiated with a daily UVB dose of 0.25 J/cm(2) or 0.5 J/cm(2) for 4 days. One day after finishing the irradiations the rabbits were sacrificed and corneal light absorption measured using our spectrophotometrical method. Corneal hydration was examined using an ultrasonic Pachymeter every experimental day before the irradiation procedure and the last day before sacrificing the animals.

RESULTS

Changes in corneal optics appeared after the repeated exposure of the cornea to a UVB dose of 0.25 J/ cm(2) and massively increased after the repeated exposure of the cornea to a UVB dose of 0.5 J/cm(2). The first significant changes in corneal hydration appeared after a single exposure of the cornea to a UVB dose of 0.25 J/cm(2).

CONCLUSIONS

Changes in corneal hydration appeared after the exposure of the rabbit cornea to a single UVB dose equivalent to 2.6 hours of solar UVB radiation reaching the human cornea, as measured by UVB sensors embedded in the eyes of mannequin heads facing the sun on a beach at noon in July. Repeated exposure of the rabbit cornea to the same UVB dose evoked profound changes in corneal optics. Although comparison of experimental and outdoor conditions are only approximate, the results in rabbits point to the danger for the human eye from UVB radiation when short stays in sunlight are repeated for several consecutive days without UV protection.

Occupational exposure control: the problem of quantities in radiation protection

The paper explores the quantities and units used in radiation protection with special emphasis on their applications in occupational exposure control. An overview of the current situation reveals that there seem to be too many different quantities associated with the same unit. Some of these quantities are defined in a quite complicated manner and, therefore, may cause some confusion in their interpretation and practical use in the field. Some suggestions towards the simplification of the present system are also proposed.

Czech Republic 20 years after Chernobyl accident

The territory of the Czech Republic was contaminated as a result of the breakdown in the Chernobyl nuclear power plant in 1986. The Czech population received low doses of ionising radiation which, though it could not cause a deterministic impact, could have had stochastic effects expressed in the years following the accident. Twenty years after the accident is a long enough time to assess its stochastic effects, primarily tumours and genetic impairment. The moderate amount of radioactive fallout received by the Czech population in 1986 increased thyroid cancer in the following years; on the other hand, no obvious genetic impact was found.

Immunological response in the mouse melanoma model after local hyperthermia

Our study was aimed to characterize the phenotype and functional endpoints of local microwave hyperthermia (LHT, 42 degrees C) on tumor infiltrating and spleen leukocytes. The effectiveness of LHT applied into the tumor of B16F10 melanoma-bearing C57/BL6 mice was compared with anesthetized and non-treated animals. Subpopulations of leukocytes were analyzed using the flow cytometry, and the cytotoxic activity of splenocytes against syngeneic B16F10 melanoma and NK-sensitive YAC-1 tumor cell lines was evaluated in (51)Cr-release assay. Similarly, the in vitro modification of the heat treatment was performed using healthy and melanoma-bearing splenocytes. We found a 40 % increase of activated monocytes (CD11b+CD69+) infiltration into the tumor microenvironment. In the spleen of experimental animals, the numbers of cytotoxic T lymphocytes (CTLs-CD3+CD8+) and NK cell (CD49b+NK1.1+) raised by 22 % and 14 %, respectively, while the NK1.1+ monocytes decreases by 37 %. This was accompanied by an enhancement of cytotoxic effector function against B16F10 and YAC-1 targets in both in vivo and in vitro conditions. These results demonstrate that LHT induces better killing of syngeneic melanoma targets. Furthermore, LHT evokes the homing of activated monocytes into the tumor microenvironment and increases the counts of NK cells and CTL in the spleen.

Temperature dependence of blood surface tension

Whole blood surface tension of 15 healthy subjects recorded by the ring method was investigated in the temperature range from 20 to 40 degrees C. The surface tension omega as a function of temperature t ( degrees C) is described by an equation of linear regression as omega(t) = (-0.473 t + 70.105) x 10(-3) N/m. Blood serum surface tension in the range from 20 to 40 degrees C is described by linear regression equation omega(t) = (-0.368 t + 66.072) x 10(-3) N/m and linear regression function of blood sediment surface tension is omega(t) = (-0.423 t + 67.223) x10(-3) N/m.

Preventive administration of GS Imunostim as a protection against acute respiratory infections

With respect to the fact that acute respiratory infections (hereafter ARI) are a world-wide serious social and economic problem, more and more attention is being paid to the development and application of oral bacterial immunomodulators. The preventive effect of GS Imunostim has been evaluated during the respiratory season 2005. The study took place at 10 outpatient sites of general practitioners and lung specialists in Prague, Pilsen and Brno in the respiratory season from January to April 2005. The comparison with the ARI morbidity reports in the studied period revealed statistically significant morbidity reduction in the study participants compared to the ARI morbidity in the Czech population in the studied period from January to April 2005. The morbidity rate in the studied group was 7%, whereas ARI morbidity 15.1% was reported in the general population. The morbidity in the study group was significantly lower that in the general population.

Effect of agroclavine on NK activity in vivo under normal and stress conditions in rats

Agroclavine is a natural, clavine type of ergot alkaloid with D1 dopamine and a-adrenoceptor agonistic properties. We showed previously that in vitro agroclavine enhances natural killer (NK) cell activity, increases interleukin-2 and interferon-gamma production and prolongs the survival time of tumor-bearing mice. The aim of this study was 1) to test the effect of agroclavine on NK activity in vivo, and 2) to assess the potential toxicity of high doses of agroclavine on cardiac and liver functions using creatine kinase MB (CKMB) and alanine aminotransferase (ALT) as biochemical markers in normal and stressed animals. The effect of stress was studied because we examined promising anticancer properties of agroclavine and malignant diseases are supposed to be a potent stressful event for patients. In our experiments 3-month-old male rats of the Wistar-Kyoto strain were used. Agroclavine was injected intraperitoneally (0.5 mg/kg or 0.05 mg/kg) 30 min before stress (four hours' restraint and immersion in 23 degrees C water). The animals were killed 30 min after stress, blood was collected and the spleen was removed. Non-stressed animals treated with agroclavine were killed 5 h after the drug administration. The results confirmed our previous in vitro results and showed that also in vivo agroclavine increases NK cell activity under non-stress conditions. Agroclavine only slightly increased CKMB and had no influence on ALT in non-stressed animals. These promising results are limited by the fact that agroclavine (0.5 mg/kg) diminished NK cell activity and significantly increased ALT and CKMB under stress conditions.

Exposure to stress alters the effects of dynorphins in the hot plate test

The analgesic effects of intracerebroventricularly (i.c.v.) administered dynorphin A(1-13) and its analog dynorphin A(1-10)amide using the hot plate test were studied in mice. Both dynorphins applied i.c.v. by the freehand method had an analgesic effect but no effect was seen when applied i.c.v. through an implanted cannula. Moreover, freehand i.c.v. injection of saline increased the time of immobility in the forced swimming test and glycaemia levels compared with intact mice. In contrast to the freehand injection, saline administration through an implanted cannula did not influence the immobility of animals in forced swimming test when compared with the intact controls. These results suggest that 1) the freehand method is very stressful procedure of administration which could influence the effects of dynorphins in the hot plate test and 2) dynorphins exert an analgesic effect in the hot plate test only when combined with a stressor (freehand i.c.v. injection).

Surface tension of blood

The surface tension of blood assessed in a group of 71 healthy subjects (24 men and 47 women) by the drop method at a temperature of 22 degrees C was 55.89 x 10(-3) N x m(-1), S.D.=3.57 x 10(-3) N x m(-1). It did not correlate with age or sex of the examined subjects nor with any of the following variables: red cell sedimentation rate, blood haemoglobin levels, number of erythrocytes, total serum cholesterol, total serum triacylglycerols, creatinine blood levels, ALT and AST activity. The surface tension of blood and other body fluids can play an important part not only in the genesis and development of decompression sickness but also in other processes in the organism.

The effect of drugs on the mortality of mice inoculated with Friend leukaemia virus or toxoplasma gondii

Infection and tumors provoke substantial changes accompanied with the disbalance of many neuroendocrine factors which in their summarizing effects influence the life span of animals. Our previous results showed enhanced mortality after one injection of morphine in association with Friend leukaemia virus infection. The aim of this study was to examine the effects of some other opioids (pethidine and pentazocine) and an acetylcholine esterase inhibitor neostigmine on the survival of animals under two conditions: (1) Friend leukaemia virus infection which mostly depressed immune functions, and (2) Toxoplasma gondii infection which in general enhanced the immune status. In contrast to our previous observation with morphine, the mortality induced by single doses of pethidine (150 mg/kg) or pentazocine (50-75 mg/kg) was unchanged during the Friend leukaemia virus infection. A single injection of neostigmine (0.42 or 0.56 mg/kg) was significantly more lethal in DBA-2 mice infected with Friend leukaemia virus. Neostigmine in doses of 0.33 and 0.4 mg/kg caused death in 46 % and 57 %, respectively, of animals infected with Toxoplasma gondii which was significantly higher in comparison with only 8 % and 12.5 % in control groups. Pethidine (150 mg/kg) killed 70 % of Toxoplasma gondii infected animals and even 90 % of non-infected mice. Thus, the Friend leukaemia virus and Toxoplasma gondii infections increased toxicity only of some drugs which may, at least partly, be associated with altered immune status during infection and involvement of the cholinergic system.

Influence of dynorphin A (1-13) and dynorphin A (1-10) amide on stress-induced analgesia

Dynorphin A (1-13) and its analog dynorphin A (1-10) amide were applied intracerebroventricularly in male ICR mice. Both dynorphins did not reveal any analgesic activity in tail-flick test under normal (non-stressed) conditions. However, in combination with stress (forced swimming or whole body vibration) both dynorphins prolonged tail-flick latencies when compared with stressed saline controls. Naloxone inhibited the effect of dynorphins in forced swimming test. Neither dynorphin A (1-13) nor dynorphin A (1-10) amide increased tail-flick latencies when combined with weak immobilization stress. Our results suggest that the analgesic effects of dynorphins are potentiated by strong stressors.