Added value of randomised biopsy to multiparametric magnetic resonance imaging-targeted biopsy of the prostate in a contemporary cohort

OBJECTIVE

To assess the added value of concurrent systematic randomised ultrasonography-guided biopsy (SBx) to multiparametric magnetic resonance imaging (mpMRI)-targeted biopsy and the additional rate of overdiagnosis of clinically insignificant prostate cancer (ciPCa) by SBx in a large contemporary, real-world cohort.

PATIENTS AND METHODS

A total of 1552 patients with positive mpMRI and consecutive mpMRI-targeted biopsy and SBx were enrolled. Added value and the rate of overdiagnosis by SBx was evaluated.

PRIMARY OUTCOME

added value of SBx, defined as detection rate of clinically significant PCa (csPCa; International Society of Urological Pathology [ISUP] Grade ≥2) by SBx, while mpMRI-targeted biopsy was negative or showed ciPCa (ISUP Grade 1).

SECONDARY OUTCOME

rate of overdiagnosis by SBx, defined as detection of ciPCa in patients with negative mpMRI-targeted biopsy and PSA level of <10 ng/mL.

RESULTS

Detection rate of csPCa by mpMRI-targeted biopsy and/or SBx was 753/1552 (49%). Added value of SBx was 145/944 (15%). Rate of overdiagnosis by SBx was 146/656 (22%). Added value of SBx did not change when comparing patients with previous prostate biopsy and biopsy naïve patients. In multivariable analysis, a Prostate Imaging-Reporting and Data System (PI-RADS) 4 index lesion (odds ratio [OR] 3.19, 95% confidence interval [CI] 1.66-6.78; P = 0.001), a PI-RADS 5 index lesion (OR 2.89, 95% CI 1.39-6.46; P = 0.006) and age (OR 1.05, 95% CI 1.03-1.08; P < 0.001) were independently associated with added value of SBx.

CONCLUSIONS

In our real-world analysis, we saw a significant impact on added value and added rate of overdiagnosis by SBx. Subgroup analysis showed no significant decrease of added value in any evaluated risk group. Therefore, we do not endorse omitting concurrent SBx to mpMRI-guided biopsy of the prostate.

mpMRI-targeted biopsy of the prostate in men ≥ 75 years. 7-year report from a high-volume referral center

OBJECTIVE

Multiparametric magnetic resonance imaging (mpMRI) -Ultrasound- fusion guided biopsy of the prostate (FBx) is the new gold standard for the detection of prostate cancer. Hallmark studies showing superior detection rates of FBx over randomized biopsies routinely excluded patients≥75 years and information on outcome of FBx on this patient cohort is sparse. As a large referral center, we have performed FBx on a substantial number of patients this age. By evaluating outcome of FBx of patients over the age of 75 years we wanted to close the gap of knowledge on this patient cohort.

MATERIALS AND METHODS

Between 2015 -2022, 1577 patients underwent FBx at our department and were considered for analysis. Clinical and histopathological parameters were recorded. Clinical data comprised age at FBx, serum level of Prostate-specific antigen (PSA), prostate volume, PSA-density, history of previous biopsies of the prostate, result of the digital rectal examination (DRE) and assessment of the indexlesion of mpMRI according to the Prostate Imaging and Reporting Data System (PI-RADS). Univariate analysis and multivariable logistic regression was used to identify age barrier of 75 years as a potential risk factor of detection of clinically significant prostate cancer by FBx.

RESULTS

379/1577 patients (24%) were≥75 years and 1198/1577 (76%) patients were < 75 years, respectively. Preoperative PSA was significantly higher in patients≥75 years compared to patients < 75 years (9.54 vs. 7.8, p < 0.001). Patients≥75 years presented significantly more often with mpMRI target lesions classified as PI-RADS 5 compared to patients < 75 years (45% vs. 29%, p < 0.001). Detection rate of clinically significant prostate cancer was significantly higher in patients≥75 years compared to patients < 75 years (63% vs. 43%, p < 0.001). Aggressive prostate cancer grade ISUP 5 was significantly more often detected in patients≥75 years compared to patients < 75 years (13% vs. 8%, p = 0.03). On multivariable logistic regression model adjusted for PSA and PI-RADS score, age barrier of 75 years was identified as a significant risk factor for the detection of clinically significant prostate cancer by FBx (OR: 1.77, 95% CI: 1.36 -2.31, p < 0.001).

CONCLUSION

After evaluation of a large patient cohort, we show that age≥75 years represents a significant risk factor for the detection of clinically significant prostate cancer. Further studies on mid- and long term outcome are necessary to draw conclusions for clinical decision making in this patient cohort.

Surgical Trends and Complications in Partial and Radical Nephrectomy: Results from the GRAND Study

BACKGROUND

We aimed to evaluate the current trends in renal cancer surgery, as well as to compare the perioperative outcomes of partial versus radical nephrectomy.

METHODS

We used the GeRmAn Nationwide inpatient Data (GRAND), provided by the Research Data Center of the Federal Bureau of Statistics (2005-2021). We report the largest study in the field, with 317,843 patients and multiple patient-level analyses.

RESULTS

Overall, 123,924 (39%) patients underwent partial and 193,919 (61%) underwent radical nephrectomy in Germany from 2005 to 2021. Of them, 57,308 (18%) were operated on in low-, 142,702 (45%) in intermediate-, and 117,833 (37%) in high-volume centers. A total of 249,333 (78%) patients underwent open, 44,994 (14%) laparoscopic, and 23,516 (8%) robotic nephrectomy. The number of patients undergoing renal surgery remained relatively stable from 2005 to 2021. Over the study period, the utilization of partial nephrectomy increased threefold, while radical nephrectomy decreased by about 40%. After adjusting for major risk factors in the multivariate regression analysis, radical nephrectomy was associated with 3.2-fold higher odds (95% CI: 3.2 to 3.9, p < 0.001) of 30-day mortality, longer hospitalization by 1.9 days (95% CI: 1.9 to 2, p < 0.001), and higher inpatient costs by EUR 1778 (95% CI: 1694 to 1862, p < 0.001) compared to partial nephrectomy. Furthermore, radical nephrectomy had a higher risk of in-hospital transfusion (p < 0.001), sepsis (p < 0.001), acute respiratory failure (p < 0.001), acute kidney disease (p < 0.001), acute thromboembolism (p < 0.001), surgical wound infection (p < 0.001), ileus (p < 0.001), intensive care unit admission (p < 0.001), and pancreatitis (p < 0.001).

CONCLUSIONS

More patients are offered partial nephrectomy in Germany. Patients undergoing radical nephrectomy present with a higher rate of concomitant risk factors and have increased perioperative morbidity and mortality, prolonged hospitalization, and increased in-hospital costs.

The Impact of Prostate Volume on the Prostate Imaging and Reporting Data System (PI-RADS) in a Real-World Setting

Multiparametric magnetic resonance imaging (mpMRI) has emerged as a new cornerstone in the diagnostic pathway of prostate cancer. However, mpMRI is not devoid of factors influencing its detection rate of clinically significant prostate cancer (csPCa). Amongst others, prostate volume has been demonstrated to influence the detection rates of csPCa. Particularly, increasing volume has been linked to a reduced cancer detection rate. However, information about the linkage between PI-RADS, prostate volume and detection rate is relatively sparse. Therefore, the current study aims to assess the association between prostate volume, PI-RADS score and detection rate of csP-Ca, representing daily practice and contemporary mpMRI expertise. Thus, 1039 consecutive patients with 1151 PI-RADS targets, who underwent mpMRI-guided prostate biopsy at our tertiary referral center, were included. Prior mpMRI had been assessed by a plethora of 111 radiology offices, including academic centers and private practices. mpMRI was not secondarily reviewed in house before biopsy. mpMRI-targeted biopsy was performed by a small group of a total of ten urologists, who had performed at least 100 previous biopsies. Using ROC analysis, we defined cut-off values of prostate volume for each PI-RADS score, where the detection rate drops significantly. For PI-RADS 4 lesions, we found a volume > 61.5 ccm significantly reduced the cancer detection rate (OR 0.24; 95% CI 0.16-0.38; p < 0.001). For PI-RADS 5 lesions, we found a volume > 51.5 ccm to significantly reduce the cancer detection rate (OR 0.39; 95% CI 0.25-0.62; p < 0.001). For PI-RADS 3 lesions, none of the evaluated clinical parameters had a significant impact on the detection rate of csPCa. In conclusion, we show that enlarged prostate volume represents a major limitation in the daily practice of mpMRI-targeted biopsy. This study is the first to define exact cut-off values of prostate volume to significantly impair the validity of PI-RADS assessed in a real-world setting. Therefore, the results of mpMRI-targeted biopsy should be interpreted carefully, especially in patients with prostate volumes above our defined thresholds.

[Common errors, pitfalls, and management of complications of prostate biopsy : The most common diagnostic and procedural challenges of transrectal fusion prostate biopsy in the initial diagnosis of clinically significant prostate cancer]

BACKGROUND

Transrectal (TR) prostate biopsy is the gold standard in diagnosis of prostate cancer (PC). It requires a precise and safe technique for sample acquisition.

OBJECTIVE

Several approaches will be discussed to avoid overdiagnosis, false-negative results, and complications of the procedure.

MATERIALS AND METHODS

We analyzed national and European guidelines, systematic reviews, meta-analyses, as well as prospective and retrospective studies to describe current trends in indication and performance of biopsies.

RESULTS

Incorporation of risk calculators and magnetic resonance imaging (MRI) into daily routine reduces biopsy rates and results in a more precise diagnosis of clinically significant prostate cancer (csPC). Combination of random- and MRI-fusion guided biopsy-but also extending the radius of sampling by 10 mm beyond the MRI lesion and a transperineal (TP) sampling approach - lead to a higher tumor-detection rate. Bleeding is the most common complication after prostate biopsy and is usually self-limiting. Postbiopsy infection rates can be reduced through TP biopsy.

CONCLUSION

TR MRI-fusion guided biopsy is a widely acknowledged tool in primary diagnostics of csPC. Higher detection rates and safety can be achieved through a TP sampling approach.

Lipid composition of different parts of Cape gooseberry (Physalis peruviana L.) fruit and valorization of seed and peel waste

The consumption of Cape gooseberry (Physalis peruviana L.) fruit (CG), fresh or processed, is gaining popularity worldwide, due to its nutritional and medicinal benefits. This study was based on the analysis of the lipid fraction of different parts of CG fruit and on further valorization of the resulting CG waste. The content of glyceride oil in CG seeds, peels and seed/peel waste, as well as the individual fatty acid, sterol and tocopherol composition of the oils was determined. CG seeds and seed/peel waste were a rich source of oil (up to 22.93%), which is suitable for nutritional application, due to its high proportions of unsaturated fatty acids (up to 83.77%), sterols (campesterol, Δ5-аvenasterol, β-sitosterol) and tocopherols (β-, δ- and γ-tocopherols). Seed/peel waste and the extracted seed cakes contained macro- and microminerals (K, Mg, Na, Fe, Zn, Mn, Cu) which are important for human and animal nutrition. Seed cakes had relatively high protein (24.32%) and cellulose (42.94%) contents, and an interesting amino acid profile. The results from the study contribute to a deeper understanding of the composition of CG fruit, and might be of practical relevance in the development of functional foods and feeds.

Telehealth in Uro-oncology Beyond the Pandemic: Toll or Lifesaver?

BACKGROUND

Telehealth services are rapidly embraced in uro-oncology due to the current coronavirus disease 2019 (COVID-19) pandemic.

OBJECTIVE

To determine patients' perspective on adoption of telehealth as a response to the pandemic and its sustainability in the future.

DESIGN, SETTING, AND PARTICIPANTS

Following a COVID-19 outbreak, 101 patients with advanced genitourinary cancers are currently managed "virtually" for therapy administration at our tertiary care unit. They were surveyed about the current situation, and current and long-term employment of telehealth.

INTERVENTION

Rapid implementation of virtual patient management.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Patients' perception of anxiety of COVID-19 and cancer, perspective on telehealth measures as a reaction to the current COVID-19 pandemic, and long-term acceptance were used as outcomes. Wilcoxon matched-pair signed rank test, chi-square test, and Mann-Whitney U test were performed.

RESULTS AND LIMITATIONS

Of 101 patients, 92 answered the questionnaire, with 71 (77.2%) responding virtually by e-mail or phone call. Anxiety of cancer (6/10, interquartile range [IQR] 3-8) superseded that of COVID-19 (four/10, IQR 2-5.25, p<0.001), and patients oppose temporary treatment interruption. Of the patients, 66.0% perceive their susceptibility to COVID-19 as equal to or lower than the general population and 52.2% believe that COVID-19 will not affect their therapy. In future, patients (62.6%) prefer to maintain in-person appointments as opposed to complete remote care, but accept remote care during the pandemic (eight/10, IQR 5-9). Beyond the crisis, maintaining telehealth has low preference rates (four/10, IQR 2-7), with high acceptance for external laboratory controls (60.9%) and online visit management (48.9%), but lower acceptance for remote treatment planning including staging discussions (44.6%) and for referral to secondary care oncologists (17.4%).

CONCLUSIONS

Despite the pandemic, cancer remains the key concern and patients are not willing to compromise on their treatment. Rapid implementation of telehealth is tolerated well during the need of social distancing, with a clear "red line" concerning changes in existing patient-physician relationships. Balancing future implementation of telehealth while considering patients' demand for personal relationships will ensure human dignity in uro-oncology.

PATIENT SUMMARY

We queried patients with genitourinary cancers treated in an almost virtual setting following a local coronavirus outbreak. Acceptance of telehealth during the current situation is high; however, long-term implementation of the adapted services is less favored. We deduce that patient-physician relationship is crucial for cancer patients and needs to be balanced against measures for social distancing to forge the future management.

Results of the Collaborative International Evaluated Library Organisation (CIELO) Project

Simulation of nuclear systems requires complete data that represents the relevant nuclear physics. This requires many types of experimental measurements, theoretical physics, semi-empirical models and software systems, as well as experts to integrate and guide the process. This discipline is collectively known as nuclear data, and separate programmes within various European countries, the USA, Japan, Russia, and other OECD Nuclear Energy Agency (NEA) member countries have been operating for many decades. The NEA Working Party on International Nuclear Data Evaluation Co-operation (WPEC) exists to improve the quality and completeness of nuclear data by bringing together representatives of the major nuclear data evaluation projects of NEA member countries and selected Invitees. The Sub- and Expert Groups of the WPEC typically focus on specific technical topics, while the Collaborative International Evaluated Library Organisation Pilot Project (CIELO) was established to generate complete evaluations for a selection of the most important isotopes for criticality in nuclear technologies: 235,238U, 239Pu, 56Fe, 16O and 1H.

This project stimulated numerous activities, resulting in major contributions to the Special Issue of the Nuclear Data Sheets journal and the production of a suite of new nuclear data evaluations that have been incorporated in major nuclear data libraries ENDF and JEFF. The outcomes of these evaluations include significant harmonisa-tion of discrepancies between the independent programmes, improvement in the performance for international standard nuclear criticality and neutron transmission benchmarks, complete uncertainties for nearly all parameters and the utilisation of modern data storage technologies. This work has leveraged the considerable, parallel experimental work in collecting improved experimental measurements to support nuclear data and highlighted high-priority areas for further study. A productive and durable framework for international evaluation has been established which will build upon the lessons learned. These will continue through new WPEC groups and a new IAEA evaluation network, which has been initiated in response to the success of the CIELO project. This article summaries some performance feedback on the CIELO evaluations, including recent results, and will describe ongoing and future, planned CIELO-related collaborations to further advance our understanding.

Vitrectomy for primary symptomatic vitreous opacities: an evidence-based review

Floaters are a common ocular condition which form as a consequence of aging changes in the vitreous. Although in most patients the symptoms are minimal, they can cause significant impairment in vision-related quality of life in a small population of patients. Recently there has been an increase in awareness of the visual disability caused by floaters, and the evidence-base for treatment of this condition using small-gauge vitrectomy has increased. In this review, we define the term 'floaters' as symptomatic vitreous opacities (SVO). We suggest a classification dependent on the presence or absence of posterior vitreous detachment and discuss their pathogenesis and natural history. We review their impact on patients' quality of life related to visual function. We review the psychological factors that may have a role in some patients who appear to be affected by SVO to the extent that they pursue all options including surgery with all its attendant risks. We summarise the available evidence-base of treatment options available for SVO with special emphasis on the safety and efficacy of vitrectomy for this condition.

Electrochromic and optical study of atmospheric pressure chemical vapour deposition MoO3-Cr2O3 films

Electrochromism (EC) is a phenomenon in which materials are able to change their optical properties in a reversible and persistent way under the action of a voltage pulse. The studied MoO3-Cr2O3 films are obtained by atmospheric pressure CVD. Mixing MoO3 films with Cr2O3 is expected to enhance optical transparency and to modulate electrochromic properties of MoO3 films. In the present work, the study is focused on the morphological, structural and optical properties of MoO3-Cr2O3 films as a function of annealing temperatures. Raman spectroscopy and optical spectrophotometry are used for the film characterization. The mixed oxide films obtained on ordinary glass substrates show transmittance values in the range of 70-80%. Surface morphology is analyzed by SEM and AFM methods. The microanalysis of MoO3-Cr2O3 films reveals uniform distribution of the elements, which is a sign of homogeneous structure.

Minimal alterations in T-type calcium channel gating markedly modify physiological firing dynamics

T-type calcium channel isoforms expressed in heterologous systems demonstrate marked differences in the biophysical properties of the resulting calcium currents. Such heterogeneity in gating behaviour not only reflects structural differences but is also observed following the regulation of channel activity by a number of ligands. However, the physiological impact of these differences in gating parameters of the T channels has never been evaluated in situ where the unique interplay between T-type calcium and other intrinsic currents is conserved, and T channel activation can be triggered by synaptic stimulation. Here, using the dynamic clamp technique, artificial T conductances were re-incorporated in thalamic neurons devoid of endogenous T currents to dissect the physiological role of the T current gating diversity on neuronal excitability. We demonstrate that the specific kinetics of the T currents in thalamocortical and nucleus reticularis thalami neurons determine the characteristic firing patterns of these neurons. We show that subtle modifications in T channel gating that are at the limit of the resolution achieved in classical biophysical studies in heterologous expression systems have profound consequences for synaptically evoked firing dynamics in native neurons. Moreover, we demonstrate that the biophysical properties of the T current in the voltage region corresponding to the foot of the activation and inactivation curves drastically condition physiologically evoked burst firing with a high degree of synaptic input specificity.

MIBI scintigraphy in hypofunctioning thyroid nodules--can it predict the dignity of the lesion?

AIM

Several authors have investigated the value of technetium-MIBI scanning to predict the dignity of hypofunctioning, cold thyroid nodules (HTN) in regions with differing levels of iodine supply. They concluded that an MIBI scan can exclude thyroid malignancy, although comparisons between the studies are of limited value owing to differences in methodology and wide variations in patient selection criteria. The present study investigates whether the above claim is also valid in Germany, a country with a long-standing and persistent, mild iodine deficiency and a high incidence of nodules in large goiters with a low prevalence of malignancy.

PATIENTS, METHODS

The study compares the results of 99mTc-MIBI scintigraphy (incl. SPECT and planar images) in HTN (MIBI) with those of fine-needle aspiration biopsy (FNAB) and histology. Of 154 consecutive patients (121 women, 33 men; mean age 56 +/- 12 years), 73 underwent thyroid surgery from which the results of FNAB and MIBI were assessed. Selection criteria were risk estimation or conditions limiting the feasibility of FNAB. The mean thyroid volume was 42 +/- 25 ml, with 2.1 +/- 1.4 nodules per patient.

RESULTS

Histology revealed thyroid malignancies in 8 out of 73 patients (11.0%). The negative predictive value for MIBI was 97%, which is comparable to FNAB (94%). However, in 19.5% of patients FNAB was indeterminate. Lower specificity (54%) and low positive predictive value (19%) showed that MIBI accumulation cannot differentiate between malignant and benign thyroid nodules. However, comparison with cytological and/or histological findings indicated that it could distinguish between lesions with differing rates of mitochondrial metabolism.

CONCLUSION

Even in areas of former or mild iodine deficiency MIBI forms a basis for choosing between wait-and-see and surgical strategies if FNAB is unfeasible or not representative. However, even for pathological MIBI results, the prevalence of malignancy is not very high.

Hypermethylation of Ron proximal promoter associates with lack of full-length Ron and transcription of oncogenic short-Ron from an internal promoter

The gene for tyrosine-kinase receptor Ron (MST1R) resides in the chromosome 3p21.3 region, frequently affected in common human malignancies. The gene generates two transcripts, 5 and 2 kb-long, full-length Ron (flRon) and short-form Ron (sfRon), respectively. Here, we show for the first time that the variegated Ron expression is associated with variations in the methylation patterns of two distinct CpG islands in Ron proximal promoter. Widespread hypermethylation associates with lack of flRon whereas hypermethylation of the distal island associates with transcription of sfRon, a constitutively active tyrosine-kinase that drives cell proliferation. sfRon inhibition with kinase-dead transgenes decreases cancer cell growth and induces cellular differentiation. sfRon could be a new drug target in cancer types in which it contributes to tumor progression.

Simulation studies of field shaping in rotational radiation therapy

This article presents simulation studies of field shaping in rotational radiation therapy by means of two categories of beam modifying devices: protectors and shapers. The protectors used are diminished copies of the organs at risk (OARs) and stay parallel to them during gantry rotation. Thus, each protector always keeps the corresponding OAR in its shadow, significantly reducing the irradiation. The shapers are used in order to obtain a more uniform dose distribution in the planning target volume (PTV) while preserving their initial orientation during gantry rotation. Thus, the use of beam modifying devices allows modulation of the beam intensity, to better fit irradiation requirements, at every gantry position. A software tool for calculations of geometrical position and dimensions of the beam modifying devices, using information about the shape, size, and position of the protected organ or area at risk as input, was developed. This tool was integrated into the in-house-developed Monte Carlo radiation therapy simulator (MCRTS), used to simulate the particle transport through the designed system. The verification of the software tool showed good agreement between experimental and simulation data, with discrepancies of less than 3%. Dose distributions in solid-geometry and voxel-based neck models were evaluated. Furthermore, the effectiveness of the shapers to modify the dose distribution outside the protected area was studied. Results demonstrated that the use of the shapers effectively improves dose uniformity. Studies using shapers of different materials were also carried out and resulted in similar dose distributions. The results of the simulation studies with a voxel-based model showed that rotational therapy with beam modifying devices offers adequate protection of the OAR and a uniform dose distribution outside the protected region.

Heavy metals effects on forage crops yields and estimation of elements accumulation in plants as affected by soil

Heavy metals (Cu, Cd, Pb, Zn) effect on the productivity of forage crops (clover and perennial cereal grasses) and their accumulation in plants, depending on the concentration of these elements in a soil, has been studied in micro-field experiments on three types of soil. The principle objective was to determine regularities of heavy metals migration in a soil-plant system aiming the estimation of permissible levels of heavy metals content in soils with the following elaboration of methods, which regulate the toxicants transfer to plants. Methods of field experiments, agrochemical and atomic absorption analysis were used. Results were statistically treated by Statistica 6.0, S-Plus 6. Experimental results have shown that the intensity of heavy metals accumulation in plants depends on the type of the soil, the species of plants, the physicochemical properties of heavy metals and their content in the soil. Logarithmic interdependency of heavy metals concentration in soils and their accumulation in plants is suggested. However, the strong correlation between the different heavy metals concentrations in the various soils and the yield of crops was not observed. Toxicants accumulation in crops decreased in time.

Nandrolone modulates the non-opioid and opioid analgesia and tolerance/dependence: role of sexual dimorphism

The aim of this investigation was to study the effect of the doping steroid nandrolone on metamizol and morphine-induced analgesia and tolerance/dependence in rats. Nandrolone per se did not change the basal nociceptive thresholds in both sexes. It diminished the analgesic effect of metamizol in females, revealed by tail flick test, and males, revealed by paw pressure and hot plate tests. In general, the action of nandrolone was to decrease the morphine-induced analgesia in female and male rats. This was strongly manifested by paw pressure and tail flick tests in male, and tail flick tests in female animals. Nandrolone slowed the development of opioid tolerance/dependence. It aggravated the withdrawal syndrome in the females and invigorated aggression in the males. The data provide evidence that anabolic steroid nandrolone might decrease the analgesic action of metamizol or morphine. The doping steroid could modulate opioid tolerance/dependence and the aggressive behavior in a gender dependent manner. The action of nandrolone is most likely due to profound long-term effects on the central nervous system and might be a gateway to addiction of other drugs of abuse.

Persistence of chromosome aberrations in peripheral lymphocytes from Hodgkin's lymphoma remission patients

PURPOSE

To analyse spontaneous and in vitro bleomycin-induced chromosome aberrations in peripheral lymphocytes taken from Hodgkin's disease patients after prolonged (up to 31 years) remission periods, and to consider these data from the point of view of the carcinogenic potential of anticancer therapy.

MATERIALS AND METHODS

Conventional analysis of chromosome preparations stained with azure-eosin.

RESULTS

The mean frequency and patterns of both spontaneous and induced aberrations in remission patients were significantly different from comparison groups (healthy donors and primary Hodgkin's disease patients). Individual values were characterized with high variation and did not show correlation with post-therapy time. New cancer cases diagnosed in remission patients were more frequent in subjects with high chromosome sensitivity to in vitro bleomycin challenge than in patients whose sensitivity to bleomycin was at a control level.

CONCLUSIONS

The results are interpreted as suggesting that the tumorigenic potential of radiochemotherapy is mediated via induction of genetic instability in exposed cells. Long after the therapy, the instability may become an initiating event in the development of new malignancies in affected tissues, whereas the instability induced in haemopoietic stem cells may reveal itself in peripheral lymphocytes derived from formerly exposed precursors.

Nonmelanoma skin cancers and risk of subsequent malignancies: a cancer registry-based study in Bulgaria

Analysis of new primary tumors following nonmelanoma skin cancers (NMSC) has a public health and risk assessment interest, as well as potential implications for etiologic inference. The aim of this study is to evaluate the risk of the second primary tumors occurrence after NMSC development. A cohort of 2620 cases (1335 males and 1285 females) with nonmelanoma skin cancers registered in Bulgarian National Cancer Registry in 1993 was examined. The follow-up period represented a total of 15,856 person-years at risk. Over this period 128 (83 in men, 45 in women) new secondary tumors were established. After NMSC appearance, both genders show higher risk for the second primary tumors occurrence. This risk is greater for men. For both sexes after NMSC development there is increased risk for occurrence of second primary cancers of head and neck, thyroid, lung, larynx, bladder, colon, as well as cutaneous malignant melanoma, non-Hodgkin's lymphoma and leukemias. The results of considering only basal cell carcinomas show an elevated risk in patients of both sexes for appearance of second primary tumors of head and neck, bladder, larynx, lung and colon as well as non-Hodgkin's lymphoma and cutaneous malignant melanoma. The results of considering only squamous cell carcinomas show an increased risk in persons of both sexes for development of second primary cancers of head and neck, skin, thyroid, lung, stomach, as well as leukemias, non-Hodgkin's lymphoma and cutaneous malignant melanoma. The association between NMSC and subsequent increased risk for appearance of second primary skin and visceral tumors determine the necessity of monitoring the patients with NMSC.

Adaptive environmental control for optimal results during plant microgravity experiments

The SVET Space Greenhouse (SG)--the first and the only automated plant growth facility onboard the MIR Space Station in the period 1990-2000 was developed on a Russian-Bulgarian Project in the 80s. The aim was to study plant growth under microgravity in order to include plants as a link of future Biological Life Support Systems for the long-term manned space missions. An American developed Gas Exchange Measurement System (GEMS) was added to the existing SVET SG equipment in 1995 to monitor more environmental and physiological parameters. A lot of long-duration plant flight experiments were carried out in the SVET+GEMS. They led to significant results in the Fundamental Gravitational Biology field--second-generation wheat seeds were produced in the conditions of microgravity. The new International Space Station (ISS) will provide a perfect opportunity for conducting full life cycle plant experiments in microgravity, including measurement of more vital plant parameters, during the next 15-20 years. Nowadays plant growth facilities for scientific research based on the SVET SG functional principles are developed for the ISS by different countries (Russia, USA, Italy, Japan, etc.). A new Concept for an advanced SVET-3 Space Greenhouse for the ISS, based on the Bulgarian experience and "know-how" is described. The absolute and differential plant chamber air parameters and some plant physiological parameters are measured and processed in real time. Using the transpiration and photosynthesis measurement data the Control Unit evaluates the plant status and performs adaptive environmental control in order to provide the most favorable conditions for plant growth at every stage of plant development in experiments. A conceptual block-diagram of the SVET-3 SG is presented.

Rapid stimulation of the PI3-kinase/Akt signalling pathway in developing midbrain neurones by oestrogen

Oestrogen promotes the differentiation of neurones in the central nervous system. In the rodent midbrain, the maturation of dopaminergic neurones appears to be under oestrogen control. This is supported by the fact that dopaminergic cells contain nuclear oestrogen receptors-alpha/beta (ER). Second, aromatase is transiently expressed in the developing midbrain. In previous studies, we have shown that oestrogen increases dopamine synthesis and plasticity of dopamine cells. These effects are transmitted through classical nuclear ER but require also the stimulation of nonclassical signalling pathways involving the activation of membrane receptors. This study attempted to identify nonclassical oestrogen-dependent signalling cascades which might be stimulated downstream of membrane ERs. Using cultured mouse midbrain cells, we could demonstrate by Western blotting, that oestrogen rapidly phosphorylates Akt, a kinase which is implicated in the phosphatidylinositol 3 (PI3)-kinase pathway. This effect was only seen in midbrain neurones but not astrocytes. Oestrogen-induced Akt phosphorylation was time- and dose-dependent, showing highest responses after 30 min and at a steroid concentration of 10(-8) and 10(-6) M. Immunocytochemistry for phosphorylated Akt (pAkt) demonstrated that pAkt is predominantly found in a nuclear/perinuclear position and that oestrogen exposure increased the number of pAkt-positive cells. To investigate the mechanisms which are involved in transmitting oestrogen effects on the cellular level, cells were treated with antagonists for distinct signalling pathways. The application of the nuclear ER antagonist ICI 182 780 did not abolish the oestrogen-induced Akt phosphorylation. In contrast, interrupting intracellular calcium signalling with BAPTA completely prevented this effect. The PI3-kinase inhibitor LY294002 also inhibited the activation of Akt by oestrogen. Our study clearly indicates that oestrogen can rapidly stimulate the PI3-kinase/Akt signalling cascade in differentiating midbrain neurones. This effect requires the intermediate activation of calcium-dependent signalling pathways. In conclusion, oestrogen effects in the developing midbrain appear to be connected with the PI3-kinase/Akt signalling mechanism.

The activities of Professor Curt Krause in Bulgaria

Prof. C. Krause spent six years in Bulgaria, from 1928 to 1934. He officially assumed his position on October 10, 1928, as he delivered his opening lecture titled About the past, present and future of the general pathology and pathological anatomy. He worked skillfully and with utmost devotion on the organization of the department of General Pathology and Pathological Anatomy at the Veterinary Faculty. The educational process normalized. Seven students completed their doctoral theses under his leadership and first research assistants were prepared. He lay the foundations of the pathoanatomical museum in his department. Prof. Krauseus contributions to the development of the pathological anatomy in Bulgaria both as a scientific discipline and as a veterinary practice are substantial. In 1939, Prof. Krause received the highest honour for his work in Bulgaria - he was awarded the title of doctor honoris causa of veterinary medicine of the Sofia University.