Extension of the soil monitoring network via tea bag initiatives: A 3000 km latitudinal gradient in European Russia

The increasing popularity and recognition of citizen science approaches to monitor soil health have promoted the idea to assess soil microbial decomposition based on a standard litter sample - tea bags. Although tea bag initiatives are expanding across the world, the global datasets remain biased in regard to investigating regions and biomes. This study aimed to expand the tea bag initiative to European Russia, which remains a "white spot" on the tea bag index map. We also added urban soils into the analysis, which were underestimated previously. We compared the standard and local tea brands to explore possible adaptations of the standard approach to regions with limited access to standard tea brands. The established monitoring network included natural and urban sites in six vegetation zones along a 3000 km latitudinal gradient. There was a very close linear relationship (R2 = 0.94-0.98) in the mass loss of alternative and standard tea litter. The mass loss of green tea in soil along the latitudinal gradient showed an increasing trend from north to south. Variations in the microbial decomposition of green tea were mainly explained by the latitudinal gradient, with low soil temperature identified as key factors hampering decomposition. Mass loss of the more recalcitrant rooibos tea was mainly determined via land use, with decomposition rates on average 1.3 times higher in urban soils. This pattern was in line with higher soil temperatures and pH in urban sites compared to natural counterparts. The findings of our study could prove valuable in extending the tea bag network of soil decomposition assessment into broader territories, including urban areas. Additionally, they could facilitate the involvement of citizen science and complete the database for C cycle modeling depending on climatic conditions.

Advancing small-molecule drug discovery by encoded dual-display technologies

DNA-encoded chemical library technology (DECL or DEL) has become an important pillar for small-molecule drug discovery. The technology rapidly identifies small-molecule hits for relevant target proteins at low cost and with a high success rate, including ligands for targeted protein degradation (TPD). More recently, the setup of DNA- or peptide nucleic acid (PNA)-encoded chemical libraries based on the simultaneous display of ligand pairs, termed dual-display, allows for more sophisticated applications which will be reviewed herein. Both stable and dynamic dual-display DEL technologies enable innovative affinity-based selection modalities, even on and in cells. Novel methods for a seamless conversion between single- and double-stranded library formats allow for even more versatility. We present the first candidates emerging from dual-display technologies and discuss the future potential of dual-display for drug discovery.

Technical note: Realization and uncertainty analysis for an adjustable 3D structured breast phantom in digital breast tomosynthesis

BACKGROUND

Projection imaging phantoms are often optimized for 2-dimensional image characteristics in homogeneous backgrounds. Therefore, evaluation of image quality in tomosynthesis (DBT) lacks accepted and established phantoms.

PURPOSE

We describe a 3D breast phantom with a structured, variable background. The phantom is an adaptable and advanced version of the L1 phantom by Cockmartin et al. Phantom design and its use for quality assurance measurements for DBT devices are described. Four phantoms were compared to assess the objectivity.

METHODS

The container size was increased to a diameter of 24 cm and a total height of 53.5 mm. Spiculated masses were replaced by five additional non-spiculated masses for higher granularity in threshold diameter resolution. These patterns are adjustable to the imaging device. The masses were printed in one session with a base layer using two-component 3D printing. New materials compared to the L1 phantom improved the attenuation difference between the lesion models and the background. Four phantoms were built and intra-human observer, inter-human observer and inter-phantom variations were determined. The latter assess the reproducibility of the phantom production. Coefficients of variance (V) were calculated for all three variations.

RESULTS

The difference of the attenuation coefficients between the lesion models and the background was 0.20 cm-1 (with W/Al at 32 kV, equivalent to 19-20 keV effective energy) compared to 0.21 cm-1 for 50/50 glandular/adipose breast tissue and cancerous lesions. PMMA equivalent thickness of the phantom was 47.0 mm for the Siemens Mammomat Revelation. For the masses, theV i n t r a $V_{intra}$ for the intra-observer variation was 0.248, the averaged inter-observer variation,V ¯ i n t e r $\overline{V}_{inter}$ was 0.383.V p h a n t o m $V_{phantom}$ for phantom variance was 0.321. For the micro-calcifications,V i n t r a $V_{intra}$ was 0.0429,V ¯ i n t e r = $\overline{V}_{inter}=$ 0.0731 andV p h a n t o m = $V_{phantom}=$ 0.0759.

CONCLUSIONS

Position, orientation and shape of the masses are reproducible and attenuation differences appropriate. The phantom presented proved to be a candidate test object for quality control.

On the relevance of modulation transfer function measurements in digital mammography quality control

Purpose: The relevance of presampling modulation transfer function (MTF) measurements in digital mammography (DM) quality control (QC) is examined. Two studies are presented: a case study on the impact of a reduction in MTF on the technical image quality score and analysis of the robustness of routine QC MTF measurements. Approach: In the first study, two needle computed radiography (CR) plates with identical sensitivities were used with differences in the 50% point of the MTF ( f MTF 0.5 ) larger than the limiting value in the European guidelines ( > 10 % change between successive measurements). Technical image quality was assessed via threshold gold thickness of the CDMAM phantom and threshold microcalcification diameter of the L1 structured phantom. For the second study, presampling MTF results from 595 half-yearly QC tests of 55 DM systems (16 types, six manufacturers) were analyzed for changes from the baseline value and changes in f MTF 0.5 between successive tests. Results: A reduction of 20% in f MTF 0.5 of the two CR plates was observed. There was a tendency to a lower score for task-based metrics, but none were significant. Averaging over 55 systems, the absolute relative change in f MTF 0.5 between consecutive tests (with 95% confidence interval) was 3% (2.5% to 3.4%). Analysis of the maximum relative change from baseline revealed changes of up to - 10 % for one a-Se based system and - 15 % for a group of CsI-based systems. Conclusions: A limit of 10% is a relevant action level for investigation. If exceeded, then the impact on performance has to be verified with extra metrics.

Are postoperative pain and patient satisfaction influenced by the number of ports in VATS for malignant pleural effusion treatment?

Objectives: The aim of this research is by using sociological methods of scientific research for tracking the pain and satisfaction indicators to prove that decreasing the number of ports in the VATS (Video-assisted thoracic surgery) for Malignant Pleural Effusion reduces postoperative pain and improves patient's satisfaction.Methods: Our study included 117 VATS procedures performed in the period from 01 January 2013 to 31 September 2016. The sociological method used to measure the pain indicator was an interview. The severity of postoperative pain was determined and reported according to a ten-point pain visual analogue scale (VAS). The degree of satisfaction was determined and reported according to a six-point and ten-point grading systems on the basis of a research interview procedure.Results: In the single-port method, the verbal pain scale for all the days covered by the research study statistically showed significantly lower values (P ˂ 0.0001) in comparison with the conventional method (P ˂ 0.0001). With regard to the patient's satisfaction, determined on the basis of the six-point system, the results were as follows: conventional VATS approach - average 3.1 with a standard deviation of 1.1 and ranging from 0 to 5; single-port VATS approach - average 4.3 with a standard deviation of 1.0 and within the range from 0 to 6. Conventional VATS approach - 6.8 - neutral. Single-port VATS approach - 8.1 - prevailing satisfaction.Conclusions: Based on our study and the studies of other authors, it can be concluded that postoperative pain and satisfaction after VATS in patients with MPE (Malignant pleural effusion) are influenced by the number of ports and the one-port technique shows better results than the conventional three-port method.The research study was registered and approved by the Clinical Research and Ethics Committee at the 'Prof. Dr. Stoyan Kirkovich' AD University Multi-Profile Hospital for Active Treatment Hospital, Stara Zagora. According to Protocol No. 11, Ref. No. 12471/30.10.2015 approved are the methods used by the sociological research study which uses predefined indicators to track patients who have undergone conventional VATS and single-port VATS. Indicators: postoperative pain and satisfaction.

Model and human observer reproducibility for detection of microcalcification clusters in digital breast tomosynthesis images of three-dimensionally structured test object

We compare the reproducibility of the human observers and a channelized Hotelling observer (CHO), when reading digital breast tomosynthesis (DBT) images of a physical phantom containing a breast simulating structured background and calcification clusters at three dose levels. The phantom is scanned 217 times on a Siemens Inspiration DBT system. Volumes of interest, with and without the calcification targets, are extracted and the human observers' percentage of correct (PC) scores is evaluated using a four-alternative forced choice method. A two-layer CHO is developed using the human observer results. The first layer consists of a localizing CHO that identifies the most conspicuous calcifications using two Laguerre-Gauss channels. Then a CHO with eight Gabor channels estimates the PC score for the calcification cluster. Observer reproducibility is estimated by bootstrapping, and the standard deviation (SD) is used as a figure of merit. The CHO closely approximated the human observer results for all the three dose levels with a correlation of > 0.97 . For the larger calcification cluster sizes, both observers have similar reproducibility, whereas the CHO is more reproducible for the smaller calcifications, with a maximum of 5.5 SD against 13.1 SD for the human observers. The developed CHO is a good candidate for automated reading of the calcification clusters of the structured phantom, with better reproducibility than the human readers for small calcifications.

Systematic approach to a channelized Hotelling model observer implementation for a physical phantom containing mass-like lesions: Application to digital breast tomosynthesis

PURPOSE

to develop a channelized model observer (CHO) that matches human reader (HR) scoring of a physical phantom containing breast simulating structure and mass lesion-like targets for use in quality control of digital breast tomosynthesis (DBT) imaging systems.

METHODS

A total of 108 DBT scans of the phantom was acquired using a Siemens Inspiration DBT system. The detectability of mass-like targets was evaluated by human readers using a 4-alternative forced choice (4-AFC) method. The percentage correct (PC) values were then used as the benchmark for CHO tuning, again using a 4-AFC method. Three different channel functions were considered: Gabor, Laguerre-Gauss and Difference of Gaussian. With regard to the observer template, various methods for generating the expected signal were studied along with the influence of the number of training images used to form the covariance matrix for the observer template. Impact of bias in the training process on the observer template was evaluated next, as well as HR and CHO reproducibility.

RESULTS

HR performance was most closely matched by 8 Gabor channels with tuned phase, orientation and frequency, using an observer template generated from training image data. Just 24 DBT image stacks were required to give robust CHO performance with 0% bias, although a bias of up to 33% in the training images also gave acceptable performance. CHO and HR reproducibility were similar (on average 3.2 PC versus 3.4 PC).

CONCLUSIONS

The CHO algorithm developed matches human reader performance and is therefore a promising candidate for automated readout of phantom studies.

Inter-laboratory comparison of channelized hotelling observer computation

PURPOSE

The task-based assessment of image quality using model observers is increasingly used for the assessment of different imaging modalities. However, the performance computation of model observers needs standardization as well as a well-established trust in its implementation methodology and uncertainty estimation. The purpose of this work was to determine the degree of equivalence of the channelized Hotelling observer performance and uncertainty estimation using an intercomparison exercise.

MATERIALS AND METHODS

Image samples to estimate model observer performance for detection tasks were generated from two-dimensional CT image slices of a uniform water phantom. A common set of images was sent to participating laboratories to perform and document the following tasks: (a) estimate the detectability index of a well-defined CHO and its uncertainty in three conditions involving different sized targets all at the same dose, and (b) apply this CHO to an image set where ground truth was unknown to participants (lower image dose). In addition, and on an optional basis, we asked the participating laboratories to (c) estimate the performance of real human observers from a psychophysical experiment of their choice. Each of the 13 participating laboratories was confidentially assigned a participant number and image sets could be downloaded through a secure server. Results were distributed with each participant recognizable by its number and then each laboratory was able to modify their results with justification as model observer calculation are not yet a routine and potentially error prone.

RESULTS

Detectability index increased with signal size for all participants and was very consistent for 6 mm sized target while showing higher variability for 8 and 10 mm sized target. There was one order of magnitude between the lowest and the largest uncertainty estimation.

CONCLUSIONS

This intercomparison helped define the state of the art of model observer performance computation and with thirteen participants, reflects openness and trust within the medical imaging community. The performance of a CHO with explicitly defined channels and a relatively large number of test images was consistently estimated by all participants. In contrast, the paper demonstrates that there is no agreement on estimating the variance of detectability in the training and testing setting.

Adaptive dynamics of cuticular hydrocarbons in Drosophila

Cuticular hydrocarbons (CHCs) are hydrophobic compounds deposited on the arthropod cuticle that are of functional significance with respect to stress tolerance, social interactions and mating dynamics. We characterized CHC profiles in natural populations of Drosophila melanogaster at five levels: across a latitudinal transect in the eastern United States, as a function of developmental temperature during culture, across seasonal time in replicate years, and as a function of rapid evolution in experimental mesocosms in the field. Furthermore, we also characterized spatial and temporal changes in allele frequencies for SNPs in genes that are associated with the production and chemical profile of CHCs. Our data demonstrate a striking degree of parallelism for clinal and seasonal variation in CHCs in this taxon; CHC profiles also demonstrate significant plasticity in response to rearing temperature, and the observed patterns of plasticity parallel the spatiotemporal patterns observed in nature. We find that these congruent shifts in CHC profiles across time and space are also mirrored by predictable shifts in allele frequencies at SNPs associated with CHC chain length. Finally, we observed rapid and predictable evolution of CHC profiles in experimental mesocosms in the field. Together, these data strongly suggest that CHC profiles respond rapidly and adaptively to environmental parameters that covary with latitude and season, and that this response reflects the process of local adaptation in natural populations of D. melanogaster.

Brownian Carnot engine

The Carnot cycle imposes a fundamental upper limit to the efficiency of a macroscopic motor operating between two thermal baths1. However, this bound needs to be reinterpreted at microscopic scales, where molecular bio-motors2 and some artificial micro-engines3-5 operate. As described by stochastic thermodynamics6,7, energy transfers in microscopic systems are random and thermal fluctuations induce transient decreases of entropy, allowing for possible violations of the Carnot limit8. Here we report an experimental realization of a Carnot engine with a single optically trapped Brownian particle as the working substance. We present an exhaustive study of the energetics of the engine and analyse the fluctuations of the finite-time efficiency, showing that the Carnot bound can be surpassed for a small number of non-equilibrium cycles. As its macroscopic counterpart, the energetics of our Carnot device exhibits basic properties that one would expect to observe in any microscopic energy transducer operating with baths at different temperatures9-11. Our results characterize the sources of irreversibility in the engine and the statistical properties of the efficiency-an insight that could inspire new strategies in the design of efficient nano-motors.

Nephelauxetic effect and 〈r(k)〉₄f radial integrals of Tm³⁺ in crystals

Bonding and covalency parameters have been evaluated from the nephelauxetic ratios βk=Fk (crystal)/Fk (free ion), with k=2, 4, 6, for 24 halide and chalcogenide crystals containing Tm(3+) ions. The radial expectation values for 4f electrons 〈r(k)〉4f of Tm(3+) ion in certain complex oxides, fluorides, and a sulfide have been determined by means of experimental Slater parameter shifts ΔFk relative to the Fk values for the free ion Tm IV. The 〈r(k)〉1f values derived in the dielectric screening model have been compared with those computed by different types of 4f wave functions as well as with other estimates.

Lattice Enthalpies of Lanthanide Orthoferrites LnFeO3

Lattice enthalpies Δ(L)H(θ) of lanthanide orthoferrites, LnFeO(3) have been determined by the Born-Haber cycle and compared with those calculated by an empirical equation. Enthalpies of formation of LnFeO(3) from two different sources have been employed: from oxides (Ln(2)O(3), Fe(2)O(3)), for 12 LnFeO(3), and from elements, for 8 LnFeO(3), but the differences in Δ(L)H(θ) are very small. The Born-Haber cycle in both routes results in close values of Δ(L)H(θ) to those obtained by the empirical equation of Glasser and Jenkins. A correspondence in dimension and magnitude has been found between the partial derivative of the lattice enthalpies to the molar volumes and an upper limit of the shear moduli of the lanthanide orthoferrites.

Adipokine pathways are altered in hippocampus of an experimental mouse model of Alzheimer's disease

A growing body of evidence suggests that β-amyloid peptides (Aβ) are unlikely to be the only factor involved in Alzheimer's disease (AD) aetiology. In fact, a strong correlation has been established between AD patients and patients with type 2 diabetes and/or cholesterol metabolism alterations. In addition, a link between adipose tissue metabolism, leptin signalling in particular, and AD has also been demonstrated. In the present study we analyzed the expression of molecules related to metabolism, with the main focus on leptin and prolactin signalling pathways in an APPswe/PS1dE9 (APP/PS1) transgenic mice model, at 3 and 6 months of age, compared to wild-type controls. We have chosen to study 3 months-old APP/PS1 animals at an age when neither the cognitive deficits nor significant Aβ plaques in the brain are present, and to compare them to the 6 months-old mice, which exhibit elevated levels of Aβ in the hippocampus and memory loss. A significant reduction in both mRNA and protein levels of the prolactin receptor (PRL-R) was detected in the hippocampi of 3 months old APP/PS1 mice, with a decrease in the levels of the leptin receptor (OB-R) first becoming evident at 6 months of age. We proceeded to study the expression of the intracellular signalling molecules downstream of these receptors, including stat (1-5), sos1, kras and socs (1-3). Our data suggest a downregulation in some of these molecules such as stat-5b and socs (1-3), in 3 months-old APP/PS1 brains. Likewise, at the same age, we detected a significant reduction in mRNA levels of lrp1 and cyp46a1, both of which are involved in cholesterol homeostasis. Taken together, these results demonstrate a significative impairment in adipokine receptors signalling and cholesterol regulation pathways in the hippocampus of APP/PS1 mice at an early age, prior to the Aβ plaque formation.

Radial integrals <r(k)>4f and nephelauxetic effect of Nd3+ in crystals

The radial expectation values <r(k)>4f,k=2, 4, 6, for oxygen- or halogen- coordinated Nd(3+) ions in 25 crystals have been obtained from experimental Slater parameter shifts ΔFk=Fk (free ion) - Fk (crystal) by means of the dielectric screening model. The <r(k)>4f values found by this new approach are compatible with those computed by relativistic 4f wave functions. The nephelauxetic ratios βk in respect to the free ion Nd IV have been also determined and related to covalency and bonding parameters.

Radiotherapy in the multimodality management of esophageal cancer

Squamous cell carcinoma and adenocarcinoma of the esophagus represent more than 90% of all cases of esophageal carcinoma. Although the incidence of squamous cell carcinoma has decreased, a continues increase in the incidence of adenocarcinoma has been observed, due to the increasing rate of obesity and gastroesophageal reflux disease. Treatment of carcinoma of the esophagus is complex and include surgery, chemotherapy and radiotherapy. The authors investigate the role of radiotherapy in the modern multimodality treatment of esophageal carcinomain order to derive recommendations for its implementation. The results of clinical trials and meta-analysis dealing with the radiotherapy application alone or as chemoradiation in preoperative, postoperative or definitive settings are summarized. When summarizing the data from the clinical trials and the meta-analyzes in esophageal carcinoma radiotherapy recommendations are drawn up. As a single modality radiotherapy is recommended only in palliative setting. Current data indicates that the neoadjuvant chemoradiation followed by the surgery is accepted as a standard treatment achieving 3-year overall survival rateraging between 30% and 60%. No improvement in local control or survival is observed when total irradiation dose is increased over 50.4Gy. Neoadjuvant or definitive chemoradiation became a standard treatmentin locally advanced tumors of the esophagus. Preoperative chemoradiation has proven contribution to improving treatment results when compared to surgery alone in both squamous cell and adenocarcinoma of esophagus. There is also a trend towards improved survival when neoadjuvant chemoradiation is applied compared to neoadjuvant chemotherapy alone. Data in favor of definitive radiotherapy as radical treatment are limited and its use is recommended only in case of palliation.

Lattice enthalpies, polarizabilities and shear moduli of lanthanide orthophosphates LnPO4

Lattice energies ΔLHθ of lanthanide orthophosphates, LnPO4 (Ln=Ce-Lu, excluding Pm) have been determined from the Born-Haber cycle and compared with those calculated by other methods. The Born-Haber cycle results in close values of ΔLHθ to those obtained after an empirical equation proposed by Glasser and Jenkins. It has been found that: (i) the partial derivative of the lattice enthalpies to the molar volumes corresponds by dimension and magnitude to the shear moduli of these crystals; (ii) these moduli differ for the monazite- and xenotime-type structures of LnPO4. Molar polarizabilities have been calculated for three LnPO4 with monazite structure, Ln=Ce, Nd, Sm, and for three LnPO4 with xenotime structure, Ln=Tb, Dy, Yb.

IS THERE A ROOM IN BULGARIA FOR RADIOTHERAPY OF GASTRIC CANCER?

Gastric cancer is the fourth most common cancer worldwide with one million new casesyearly and the second most frequent cause of cancer death. Although surgery is the leading treatment modality of gastric cancer the survival remains low (5- year survival is reported to be 25% in Europe and 60% in the Eastern world). The risk of locoregional recurrence grows with the increase of the tumor stage. In order to improve locoregional control a number of clinical studies in the last four decades have examined different strategies of adjuvant therapy, including chemotherapy, radiotherapy, chemoradiation with ambiguous results. Various regimens of radiotherapy alone, applied preand postoperatively or in combination with chemotherapy in pre- and postoperative settings have been studied. With the present article, the authors present the world experience of radiotherapy application in gastric carcinoma, supporting its introduction in to Bulgarian clinical practice. The study results concerning this topic have been discussed. SWOG/Intergroup 0116 study showed that postoperative chemoradiation leads to increased 5-year overall survival compared with surgery alone. A recent metaanalysis on randomized trials in operable gastric cancer, found that adjuvant radiotherapy leads to 20 % improvement in disease free survival and overall survival and found no subgroup of patients who do not benefit from adjuvant radiotherapy. The available data from the published studies and metaanalysis completely supports the introduction of chemoradiation for gastric cancer and in Bulgarian radiotherapy practice with the opportunity of gaining own experience.

Preparation, characterization and catalytic activity of NiOx and NiOx/ZrO2 for oxidation of phenol in aqueous solution

In the present study bulk NiO(x) and supported NiO(x)/ZrO(2) catalysts have been prepared. The bulk NiO(x) was synthesized using the precipitation-oxidation method with reverse order of precipitation while deposition-precipitation technique was used for the preparation of zirconia supported catalyst. The as-prepared samples were characterized by means of XRD, HRTEM, SAED, IR-spectroscopy, and chemical analyses. It was found that under the applied synthesis procedure nanosized and highly dispersed oxide materials with high active oxygen content were obtained. The catalytic activity and selectivity of these oxide catalysts have been studied in reaction of low-temperature oxidation of phenol in aqueous phase. The effects of several parameters such as catalyst amount, temperature and solution pH on the degradation efficiency of the process were also investigated. Experimental results demonstrated that phenol could be completely degraded under all reaction conditions, except at pH = 12.

Stress protein Hsp27 expression predicts the outcome in operated small cell lung carcinoma and large cell neuroendocrine carcinoma patients

PURPOSE

Heat shock protein (Hsp)27 is overexpressed in a range of human cancers and is implicated in tumor cell proliferation, differentiation, invasion, metastasis, and survival. The aim of the present study was to determine the prognostic significance of Hsp27 expression in small cell lung carcinoma (SCLC) and large cell neuroendocrine carcinoma (LCNEC).

METHODS

Surgically resected SCLCs (N=51) and LCNECs (N=15) were studied. The Hsp27 expression was detected immunohistochemically.

RESULTS

Hsp27 positive immunoreaction in the cytoplasm was observed in 45 (88%) SCLCs and 14 (93%) LCNECs. A combination of cytoplasmic with nuclear Hsp27 expression was observed in 28 (62%) SCLCs and 14 (100%) LCNECs. There was a correlation between Hsp27 cytoplasmic overexpression and Hsp27 nuclear expression with patient survival confirmed by Cox multivariate analysis.

CONCLUSION

We conclude that the higher Hsp27 cytoplasmic expression and nuclear expression may represent favorable prognostic factors in SCLC and LCNEC.

Management of upper cervical spine injuries: a review

Upper cervical spine injuries are commonly associated with trauma and require significant forces to produce. When these injuries occur they can have devastating functional consequences. The distinctive anatomy of the upper cervical spine leads injuries to occur in predictable patterns. Injuries can occur to the unique osseus structures or ligamentous connections. Common injuries include occipital condylar fractures, atlanto-occipital dislocation, fractures of the ring of C1, ligamentous injuries involving the ring of C1, and the three types of fractures of C2, pars fractures, odontoid fractures and C2 body fractures. We present these common injuries found in the occipital-atlantoaxial complex and their management based on the current and historical literature.

[Surgical treatment for intralobar pulmonary sequestration in 50-years old woman with aberrant artery from a. gastrica sin]

A case of 50-years old female, operated on for intralobar sequestration with two 2 anomalous arteries in lig. pulmonale inf., one arising from thoracic aorta and the other--from truncus coeliacus of abdominal aorta. The diagnosis was confirmed by CT scan with i.v. and a left lower lobectomy was carried out with exellent long-term result.

[Surgical treatment of pulmonary sequestration--20 years experience]

AIM

To study our experience in the diagnostics and treatment of pulmonary sequestration and to evaluate the long-term postoperative results.

MATERIAL AND METHODS

Between Jan 1989 and Jan 2009. 8 patients (3 men, 5 women, mean age of 23.9 years) were operated on for lung sequestration. Sequestration was intralobar in 6 cases and extralobar in 2 cases. The abnormality was discovered by chance in 2 patients. The most frequent clinical manifestation was those of recurrent bronchopneumonia. Chest X-rays showed an apparently benign, posterobasal image in 75% of the cases. Arteriography was performed in 2 patients and revealed an abnormal systemic artery. Computerized tomography imaging with i.v. contrast confirmed the diagnosis in 6 patients. The intralobar type of sequestration was treated by lobectomy, and the extralobar type by sequestrectomy.

RESULTS

The operative mortality and the morbidity rates were nil. The mean in-hospital stay was 7.75 days. The long-term postoperative results (follow-up from 5 to 20 years) are considered excellent.

CONCLUSION

The surgery is a method of choice in the treatment of pulmonary sequestration. with low rate of postoperative complications and excellent long-term results.

[Pleural tent after upper lobectomy--randomized study of it's efficacy and duration of the effect]

The aim of our study is to evaluate the safety, efficacy and also the maximum duration of effect of the pleural tent in reducing the incidence of air leak after upper lobectomy.

METHODS

Sixty patients who underwent upper lobectomy were prospectively randomized into two groups: 30 patients had creation of pleural tent (group 1) and 30 did not (group 2). The preoperative, operative, and postoperative characteristics of both groups were compared. Then multivariate analyses were used to identify factors predictive of prolonged air leaks and their duration. The reduction of incidences of air leak in the two groups was subsequently compared during successive postoperative periods.

RESULTS

Demographic and clinical profiles of both groups were not statistically different. The tented patients had statistically significant reduction of mean duration of air leak in days (4.9 +/- 1.79 vs 8.2 +/- 4.2), the number of days of a chest tube duration (7.3 +/- 1.14 vs 12.46 +/- 3.6), the length of postoperative in-hospital stay in days (9.4 +/- 1.86 vs 13.6 +/- 2.49), and the hospital stay cost per patient (leva, 3840 +/- 298 vs 5160 +/- 3890). Logistic regression analyses showed that no having creation a pleural tent procedure was the most significant predictive factor of the occurrence and duration of prolonged air leaks. A greater reduction in the duration of air leaks was observed before postoperative day 4 in group 1, and logistic regression analysis showed that having a pleural tent procedure was the most significant predictive factor of air leaks that persisted for less than 4 days.

CONCLUSIONS

Pleural tent creation after upper lobectomy is a simple and safe procedure that reduces the duration of air leaks and the hospital stay costs. The benefit from that procedure is achieved before postoperative day 4.

[Surgical treatment of pulmonary metastases--surgical methods, early and long-term results]

AIM

To retrospectively evaluate the postoperative results after surgery for lung metastases from extrapulmonary origin.

METHODS

A total of 45 patients were operated on for lung metastases between Jan 1996 and Dec 2006. They were 22 (48.9%) male and 23 (51.1%) female with a mean age of 51.6 years. Unilateral operation was carried out in 34 (75.6%) of the patients and another 11 (24.4%) patients were operated on for bilateral metastases. In 8 of them a one-stage operation was performed via median sternotomy (6) and bilateral successive thoracotomies (2). Two-stage strategy was applied in 3 patients. Metastasectomy via sternotomy as a surgical procedure was performed in all cases with bilateral lesions. In one case with one-stage successive thoracotomies a lobectomy and metastasectomy were used. In the group of unilateral operation the following procedures were carried out: metastasectomy in 23 (51%), lobectomy in 7 (15.6%), extended lobectomy in 2 (4.4%), sleeve lobectomy in 1 (2.2%) and polysegmental resection in 1 (2.2%). VATS was applied in 6 (13.3%) patients.

RESULTS

No 30-day postoperative mortality was faced. There were 3 (6.7%) minor postoperative complications. The mean number of resected metastases was 2.3 per patient. The primary tumor sites were as follow: colorectal carcinoma--15 (33.3%); renal carcinoma--5 (12.1%); breast carcinoma--6 (13.3%); soft tissue fibrosarcoma--6 (13.3%); osteosarcoma--4 (8.9%); melanoma--1 (2.2%); gastric carcinoma--1 (2.2%), thyreoid gland carcinoma--1 (2.2%); suprarenal carcinoma--1 (2.2%) and carcinoma of salivary gland type--1 (2.2%). Mediastinal lymph nodes dissection was carried out in all patients and in 5 (12.1%) was found a metastatic mediastinal lymph nodes involvement. Adequate control of primary site tumor was achieved in all patients. Until the end of the study 01.01.2008, 19 (42.2%) of the patients are alive. The median survival was 38 months with 95% Confidence Interval (33-43). The gender (p=0.194), metastases diameter (p=0.211), mediastinal lymphnode involvement (p=0.102), initial clinical symptoms (p=0.233) and the primary site stage (p=0.091) can not be considered as a prognostic factors. The prognosis was significantly influenced by histology (p=0.0275), but because of small number of cases in the groups result should be interpreted with caution. The disease free interval (p=0.0348) and metastases number > 3 (p=0.0456) are considered prognostic factors.

CONCLUSION

Surgery is an integral part of multimodality treatment of lung metastases with low postoperative complication rate and good long-term results. Respectability, "disease free interval" and number of metastases are considered to be the main prognostic factors.

[The role of resection surgical techniques in complex treatment of multi-resistant pulmonary tuberculosis]

A total of 16 patients with pulmonary resections for MDR-TB are included in a retrospective study for a period of 7 years. They are 9 (63.4%) male and 7 (36.3%) female with an average age of 32.6 years. Unilateral cavitary lesions are visualized in all patients. Bilateral changes are found in 9 (55.5%) patients, but the contralateral lesions are predominantly nodules and fibrosis. Multi-drug resistance was observed to an average of 4.4 anti-TB medicines. The mean duration of the preoperative re-treatment regimens is 4.9 months. Despite the preoperative anti-TB treatment, 8 (50%) of our patients are positive at the time of surgery. The following operations are carried out: lobectomy (68.75%), lobectomy with S6 (6.25%) and pneumonectomy (25%). No intraoperative and 30-day postoperative deaths are observed in our cohort. Postoperative complications are found in 4 (25%) of the cases. The mean postoperative in-hospital stay is 10.2 days. The postoperative anti-TB regimens are administered for at least 18 months, but in most of the patients their duration is 24 months. Postoperative follow-up is possible in all patients for the mean period of 34 months. Relapse of the disease is found in 3 (18.75%) preoperatively positive patients. Late mortality is observed in 1 (6.2%) patient 9 months after pneumonectomy due to relapse and empyema development. Eight (50%) of the patients are under follow-up program without medication. The rest 5 (31.25%) patients are negative but still on anti-TB regimens. In conclusion, we feel that pulmonary resections are of a paramount importance as an adjunctive method in the complex treatment of MDR-TB with good postoperative results.

[Results of the operative treatment of primary pulmonary sarcomas]

OBJECTIVE

To study and evaluate clinic, diagnostics and operative treatment of patients with primary pulmonary sarcomas (PPS).

MATERIAL AND METHODS

During 24 years period, a total of 49 patients underwent surgery for PPS. There were 29 male and 20 female with a mean age of 52.6 years. Main presenting complaints were shortness of breath, cough, chest pain, weight loss and haemoptysis. Correct preoperative diagnosis was obtained in 12 (24.48%) of the patients by bronchoscopy or percutaneous core biopsy. Carcinoma was diagnosed in 14 (28.6%) of them. Almost half of the cases were operated on without histological confirmation for suspected malignancy. The histological diagnoses were fibrosarcoma (16), fibroleiomyosarcoma (10), leiomyosarcoma (6), rhabdomyosarcoma (7), hemangiopericytoma (3), epitheloid hemangioendothelioma (3), undifferentiated sarcoma (2), malignant schwannoma (1) and liposarcoma (2). Only 2 of the tumors were scored in grade 1. The rest were classified in higher grades of malignancy. The following operations were carried out: lobectomy--30 (59.2%), including 2 sleeve lobectomies; pneumonectomy--10 (20.4%), polysegmental resections--3 (6.2%) and atypical resection--1 (2%). The resections were extended to the thoracic wall, diaphragm or pericardium in 4 patients. Endoscopic laser resection was applied in 1 (2%) case. Exploratory thoracotomy was performed on 3 (6.1%) patients. There were 2 (4.1%) stage I A; 26 (53.1%) stage I B; 11 (22.4) stage II B; 5 stage III A; 4 stage III B and 1 stage IV.

RESULTS

No postoperative death occurred. Postoperative empyema was observed in 2 cases (4.1%) and 1 patient (2%) was reoperated on for local recurrence 18 months after surgery. Adjuvant therapy was administered to 20 of the patients. Follow-up (range, 6 to 160 months) was available for 41 patients. The actuarial 5-year postoperative survival was 51.8% with mean survival of 40.8 months.

CONCLUSION

The correct preoperative diagnosis of PPS still presents a challenge. There are no specific clinical, imaging and other signs for this tumor evaluation. Surgery with systematic lymphnode dissection is a treatment of choice with an acceptable 5-year survival rate. Only the complete resection and the low stages of the tumor significantly influence survival.

[Spontaneous pneumomediastinum: clinic, diagnostics and treatment]

Spontaneous pneumomediastinum (SPM) is an uncommon, benign, self-limited disorder that usually occurs in young adults without any apparent precipitating factor or disease. The purpose of this study was to review our experience in dealing with this entity and detail a reasonable course of assessment and management. A retrospective case series of 4 patients with SPM were diagnosed and treated in a Thoraci Surgery Department at Saint Sofia Pulmonary Hospital between 2000 and 2006. The patiets' group included 3 male and 1 female with a mean age of 17.5 years (between 15 and 21). Acute onset chest pain was the predominant symptom at presentation. All of the patients developed clinically evident subcutaneous emphysema. Chest radiography and computerized tomography (CT) were diagnostic in all cases. Esophagogram and flexible bronchoscopy were used in all cases as well. All 4 patients were admitted to the hospital. Their mean hospital stay was 1.5 (between 1 and 2) days. All patients were conservatively treated. In a follow-up of 1-6 years no complications or recurrences were observed. In conclusion, SPM follows alveolar rupture in the pulmonary interstitium. It has a wide range of clinical features necessitating a high index of suspicion. Chest X-ray and CT scan should be always performed. Hospitalization and aggressive approach should be limited. SPM responds well to conservative treatment and follows a benign natural course.