Whole-genome sequencing identifies new candidate genes for nonobstructive azoospermia

BACKGROUND

Genetic causes that lead to spermatogenetic failure in patients with nonobstructive azoospermia (NOA) have not been yet completely established.

OBJECTIVE

To identify low-frequency NOA-associated single nucleotide variants (SNVs) using whole-genome sequencing (WGS).

MATERIALS AND METHODS

Men with various types of NOA (n = 39), including samples that had been previously tested with whole-exome sequencing (WES; n = 6) and did not result in diagnostic conclusions. Variants were annotated using the Ensembl Variant Effect Predictor, utilizing frequencies from GnomAD and other databases to provide clinically relevant information (ClinVar), conservation scores (phyloP), and effect predictions (i.e., MutationTaster). Structural protein modeling was also performed.

RESULTS

Using WGS, we revealed potential NOA-associated SNVs, such as: TKTL1, IGSF1, ZFPM2, VCX3A (novel disease causing variants), ESX1, TEX13A, TEX14, DNAH1, FANCM, QRICH2, FSIP2, USP9Y, PMFBP1, MEI1, PIWIL1, WDR66, ZFX, KCND1, KIAA1210, DHRSX, ZMYM3, FAM47C, FANCB, FAM50B (genes previously known to be associated with infertility) and ALG13, BEND2, BRWD3, DDX53, TAF4, FAM47B, FAM9B, FAM9C, MAGEB6, MAP3K15, RBMXL3, SSX3 and FMR1NB genes, which may be involved in spermatogenesis.

DISCUSSION AND CONCLUSION

In this study, we identified novel potential candidate NOA-associated genes in 29 individuals out of 39 azoospermic males. Note that in 5 out of 6 patients subjected previously to WES analysis, which did not disclose potentially causative variants, the WGS analysis was successful with NOA-associated gene findings.

Single-cell, high-throughput analysis of cell docking to vessel wall

Therapeutic potential of mesenchymal stem cells (MSCs) has been reported consistently in animal models of stroke, with mechanism mainly through immunomodulation and paracrine activity. Intravenous injection has been a prevailing route for MSCs administration, but cell quantities needed when scaling-up from mouse to human are extremely high putting into question feasibility of that approach. Intra-arterial delivery directly routes the cells to the brain thus lowering the required dose. Cell engineering may additionally improve cell homing, further potentiating the value of intra-arterial route. Therefore, our goal was to create microfluidic platform for screening and fast selection of molecules that enhance the docking of stem cells to vessel wall. We hypothesized that our software will be capable of detecting distinct docking properties of naïve and ITGA4-engineered MSCs. Indeed, the cell flow tracker analysis revealed positive effect of cell engineering on docking frequency of MSCs (42% vs. 9%, engineered vs. control cells, p < 0.001). These observations were then confirmed in an animal model of focal brain injury where cell engineering resulted in improved homing to the brain. To conclude, we developed a platform to study the docking of cells to the vessel wall which is highly relevant for intraarterial cell targeting or studies on neuroinflammation.

Real-time MRI for precise and predictable intra-arterial stem cell delivery to the central nervous system

Stem cell therapy for neurological disorders reached a pivotal point when the efficacy of several cell types was demonstrated in small animal models. Translation of stem cell therapy is contingent upon overcoming the challenge of effective cell delivery to the human brain, which has a volume ∼1000 times larger than that of the mouse. Intra-arterial injection can achieve a broad, global, but also on-demand spatially targeted biodistribution; however, its utility has been limited by unpredictable cell destination and homing as dictated by the vascular territory, as well as by safety concerns. We show here that high-speed MRI can be used to visualize the intravascular distribution of a superparamagnetic iron oxide contrast agent and can thus be used to accurately predict the distribution of intra-arterial administered stem cells. Moreover, high-speed MRI enables the real-time visualization of cell homing, providing the opportunity for immediate intervention in the case of undesired biodistribution.

Translation, but not transfection limits clinically relevant, exogenous mRNA based induction of alpha-4 integrin expression on human mesenchymal stem cells

Mesenchymal stem cells (MSCs) represent promising resource of cells for regenerative medicine in neurological disorders. However, efficient and minimally invasive methods of MSCs delivery to the brain still have to be developed. Intra-arterial route is very promising, but MSCs are missing machinery for diapedesis through blood-brain barrier. Thus, here we have tested a mRNA-based method to induce transient expression of ITGA4, an adhesion molecule actively involved in cell extravasation. We observed that transfection with an ITGA4-mRNA construct bearing a conventional cap analogue (7-methylguanosine) failed to produce ITGA4 protein, but exogenous ITGA4-mRNA was detected in transfected MSCs. This indicates that not transfection, but rather translation being the major roadblock. Stabilization of ITGA4-mRNA with SSB proteins resulted in ITGA4 protein synthesis in HEK293 cells only, whereas in MSCs, satisfactory results were obtained only after using an anti-reverse-cap-analogue (ARCA). The presence of ITGA4 protein in MSCs was transient and lasted for up to 24 h after transfection. Membranous location was confirmed by flow cytometry of viable non-permeabilized cells using anti-ITGA4 antibody. The mRNA-based expression of itga4 transgene is potentially sufficient for diapedesis after intra-arterial delivery. To conclude, mRNA-based engineering of stem cells is a rapid and integration-free method and attractive from the perspective of potential future clinical application.

Engineered Mesenchymal Stem Cells as an Anti-Cancer Trojan Horse

Cell-based gene therapy holds a great promise for the treatment of human malignancy. Among different cells, mesenchymal stem cells (MSCs) are emerging as valuable anti-cancer agents that have the potential to be used to treat a number of different cancer types. They have inherent migratory properties, which allow them to serve as vehicles for delivering effective therapy to isolated tumors and metastases. MSCs have been engineered to express anti-proliferative, pro-apoptotic, and anti-angiogenic agents that specifically target different cancers. Another field of interest is to modify MSCs with the cytokines that activate pro-tumorigenic immunity or to use them as carriers for the traditional chemical compounds that possess the properties of anti-cancer drugs. Although there is still controversy about the exact function of MSCs in the tumor settings, the encouraging results from the preclinical studies of MSC-based gene therapy for a large number of tumors support the initiation of clinical trials.

Pre- and postmortem imaging of transplanted cells

Therapeutic interventions based on the transplantation of stem and progenitor cells have garnered increasing interest. This interest is fueled by successful preclinical studies for indications in many diseases, including the cardiovascular, central nervous, and musculoskeletal system. Further progress in this field is contingent upon access to techniques that facilitate an unambiguous identification and characterization of grafted cells. Such methods are invaluable for optimization of cell delivery, improvement of cell survival, and assessment of the functional integration of grafted cells. Following is a focused overview of the currently available cell detection and tracking methodologies that covers the entire spectrum from pre- to postmortem cell identification.

Genetic Engineering of Mesenchymal Stem Cells for Regenerative Medicine

Mesenchymal stem cells (MSCs), which can be obtained from various organs and easily propagated in vitro, are one of the most extensively used types of stem cells and have been shown to be efficacious in a broad set of diseases. The unique and highly desirable properties of MSCs include high migratory capacities toward injured areas, immunomodulatory features, and the natural ability to differentiate into connective tissue phenotypes. These phenotypes include bone and cartilage, and these properties predispose MSCs to be therapeutically useful. In addition, MSCs elicit their therapeutic effects by paracrine actions, in which the metabolism of target tissues is modulated. Genetic engineering methods can greatly amplify these properties and broaden the therapeutic capabilities of MSCs, including transdifferentiation toward diverse cell lineages. However, cell engineering can also affect safety and increase the cost of therapy based on MSCs; thus, the advantages and disadvantages of these procedures should be discussed. In this review, the latest applications of genetic engineering methods for MSCs with regenerative medicine purposes are presented.

The cerebral embolism evoked by intra-arterial delivery of allogeneic bone marrow mesenchymal stem cells in rats is related to cell dose and infusion velocity

Introduction

Intra-arterial cell infusion is an efficient delivery route with which to target organs such as the ischemic brain. However, adverse events including microembolisms and decreased cerebral blood flow were recently reported after intra-arterial cell delivery in rodent models, raising safety concerns. We tested the hypothesis that cell dose, infusion volume, and velocity would be related to the severity of complications after intra-arterial cell delivery.

Methods

In this study, 38 rats were subjected to a sham middle cerebral artery occlusion (sham-MCAO) procedure before being infused with allogeneic bone-marrow mesenchymal stem cells at different cell doses (0 to 1.0 × 10⁶), infusion volumes (0.5 to 1.0 ml), and infusion times (3 to 6 minutes). An additional group (n = 4) was infused with 1.0 × 10⁶ cells labeled with iron oxide for in vivo tracking of cells. Cells were infused through the external carotid artery under laser Doppler flowmetry monitoring 48 hours after sham-MCAO. Magnetic resonance imaging (MRI) was performed 24 hours after cell infusion to reveal cerebral embolisms or hemorrhage. Limb placing, cylinder, and open field tests were conducted to assess sensorimotor functions before the rats were perfused for histology.

Results

A cell dose-related reduction in cerebral blood flow was noted, as well as an increase in embolic events and concomitant lesion size, and sensorimotor impairment. In addition, a low infusion velocity (0.5 ml/6 minutes) was associated with high rate of complications. Lesions on MRI were confirmed with histology and corresponded to necrotic cell loss and blood-brain barrier leakage.

Conclusions

Particularly cell dose but also infusion velocity contribute to complications encountered after intra-arterial cell transplantation. This should be considered before planning efficacy studies in rats and, potentially, in patients with stroke.

Serum fibroblast growth factor 21 is predictive of combined cardiovascular morbidity and mortality in patients with type 2 diabetes at a relatively short-term follow-up

AIMS

We hypothesised that serum fibroblast growth factor 21 (FGF-21), a novel adipokine with postulated insulin-sensitizing effects, may be predictive of cardiovascular (CV) events in patients with type 2 diabetes (DM2) at a relatively short-term follow-up.

METHODS

Serum FGF-21 levels were assessed in 87 DM2 patients, aged 57-66 years, with the median duration of diabetes of 10 years, who were referred to the Department of Endocrinology for routine annual metabolic assessment. During a follow-up of 24 months, overall mortality, CV mortality and CV nonfatal events were registered. Cox proportional hazards regression assessed adjusted differences in CV morbidity and mortality risk.

RESULTS

Patients stratified according to serum FGF-21 levels ≤ and > the median value of 240.7 pg/mL showed no significant differences at baseline in gender distribution, diabetes duration, insulin therapy, BMI, biochemical profiles and previous CV events. At 24-month follow-up, 21 (24.1%) patients experienced a nonfatal CV event. A significantly (P=0.0013) higher incidence of the combined end point of CV morbidity and mortality was observed in the FGF-21>240.7 pg/mL group. In the multivariate Cox proportional hazards regression model, the presence of FGF-21>the median value was associated with a significant increase in the risk of the combined end point of CV morbidity and mortality (HR: 4.7, 95% CI 1.67-13.24).

CONCLUSIONS

The obtained results support the prognostic value of FGF-21 in DM2 and may provide a useful tool for stratification of CV prognosis in DM2 patients.

Genetic engineering of stem cells for enhanced therapy

Stem cell therapy is a promising strategy for overcoming the limitations of current treatment methods. The modification of stem cell properties may be necessary to fully exploit their potential. Genetic engineering, with an abundance of methodology to induce gene expression in a precise and well-controllable manner, is particularly attractive for this purpose. There are virus-based and non-viral methods of genetic manipulation. Genome-integrating viral vectors are usually characterized by highly efficient and long-term transgene expression, at a cost of safety. Non-integrating viruses are also highly efficient in transduction, and, while safer, offer only a limited duration of transgene expression. There is a great diversity of transfectable forms of nucleic acids; however, for efficient shuttling across cell membranes, additional manipulation is required. Both physical and chemical methods have been employed for this purpose. Stem cell engineering for clinical applications is still in its infancy and requires further research. There are two main strategies for inducing transgene expression in therapeutic cells: transient and permanent expression. In many cases, including stem cell trafficking and using cell therapy for the treatment of rapid-onset disease with a short healing process, transient transgene expression may be a sufficient and optimal approach. For that purpose, mRNA-based methods seem ideally suited, as they are characterized by a rapid, highly efficient transfection, with outstanding safety. Permanent transgene expression is primarily based on the application of viral vectors, and, due to safety concerns, these methods are more challenging. There is active, ongoing research toward the development of non-viral methods that would induce permanent expression, such as transposons and mammalian artificial chromosomes.

Release of podocalyxin into the extracellular space. Role of metalloproteinases

Podocalyxin (PODXL) is a type I membrane mucoprotein abundantly presented in the epithelial cells (podocytes) of kidney glomeruli where it plays an important role in maintaining the plasma filtration. PODXL is also expressed in other types of cells but its function is ignored. A recombinant soluble fragment of the PODXL ectodomain modifies the signaling of the membrane bound PODXL. Based on this antecedent, we aimed at investigating whether PODXL could be cleaved and released into the extracellular space as a soluble peptide. In this study, we used a fusion protein of human PODXL and green fluorescent protein expressed in CHO cells (CHO-PODXL-GFP) and a human tumor cell (Tera-1) inherently expressing PODXL. PODXL was detected by wide-field microscopy in the Golgi, the plasma membrane and in a vesicular form preferentially located at the leading edges of the cell and also progressing along the filopodium. We detected PODXL in the insoluble and soluble fractions of the extracellular medium of CHO-PODXL-GFP cells. Stimulation of protein kinase C (PKC) by Phorbol-12-myristate-13-acetate (PMA) enhanced the release of PODXL to the extracellular space whereas this effect was prevented either by inhibitors of PKC or specific inhibitors of matrix metalloproteinases. It is concluded that intact PODXL is released to the extracellular space as a cargo of microvesicles and also as a soluble cleaved fragment of ectodomain.

Megakaryocyte gene targeting mediated by restricted expression of recombinase Cre

The availability of mice with tissue-specific expression of recombinase Cre is the limiting step for a successful gene targeting by the Cre-LoxP methodology. This work aimed at generating transgenic mice with restricted expression of recombinase Cre in megakaryocytes and platelets, driven by the promoter of the αIIb gene (mαIIb-cre). Mice oocytes were microinjected with a 4.1 Kb construct comprising a 2.7 Kb promoter fragment of the glycoprotein αIIb gene, linked to the Cre-cDNA and followed by the polyA tail of the SV40. We found four mice with positive DNA genotype and three probable sites of genomic integration of the transgene. Only two of the founders showed presence of Cre-mRNA and production of Cre protein, restricted to megakaryocytes. The activity of Cre in mediating gene targeting was assessed by crossing mαIIb-cre mice to Cre-reporter mice (ROSA26-lacZ). The activity of β-galactosidase, detected only in megakaryocytes, was sufficient to generate intense staining of X-Gal in hepatic haematopoietic islands of 14.5 dpc fetuses, in bone marrow megakaryocytes and platelets from adult mice as well as in vitro cultured megakaryocytes differentiated from bone marrow hematopoietic stem cells. Moreover, the recombinase activity was sufficient to produce the specific gene targeting of a floxed CD40L allele in megakaryocytes. The mαIIb-cre transgenic mice with restricted production of Cre in megakaryocytes, offers a selective, alternative, new tool for the genetic analysis of platelet pathophysiology.

Overexpression of podocalyxin in megakaryocytes and platelets decreases the bleeding time and enhances the agonist-induced aggregation of platelets

Podocalyxin (PODXL) is a 145KDa sialoprotein abundantly expressed in the glycocalix of the intraglomerular kidney epithelial cells, essential in maintaining a normal renal function. PODXL is also found in vascular endothelial cells, megakaryocytes and platelets. The function of PODXL in platelets is ignored; however, its surface exposure upon platelet activation suggests its participation in controlling the hemostasis. We have generated mice (pralphaIIb-PODXL) overexpressing PODXL specifically in megakaryocytes , either alone or as a fusion protein with green fluorescent protein. The transgenic mice showed a phenotype characterized by decreased bleeding time, mild rebleeding and enhanced platelets aggregation upon agonist stimulation. The cytohematological exams as well as the prothrombin time (PT) and (APTT) tests did not differ from the control group. The biochemical analysis showed only a discrete hyperlipemia and a rise in plasma uric acid levels in the transgenic mice. The present data seem to indicate that PODXL may act as a costimulator of agonists in the activation of platelets and formation of a stable thrombus.

A modified cardiac stabilizer used for recording electrograms

Originally, tissue stabilizer has been developed by Medtronic, Inc. It is used to prevent a certain part of myocardium from moving. For example, such an approach is utilized during Coronary Artery Bypass Grafting (CABG). Moreover, medical procedures during such operations involve blood arrest, thus, potentially may involve ischemia of myocardium. A construction of the modified tissue stabilizer used during surgery on a beating heart is presented in the paper. We have developed a stabilizer that aside preventing part of myocardium from moving enables recording of epicardial electrograms. Four electrograms are recorded simultaneously together with one lead of standard ECG as a reference signal. Time relations between electrograms, recorded at four different points surrounding potentially ischemic area, are strongly modified by processes triggered by myocardium ischemia. Aside a construction of the stabilizer the associated measurement system is also presented. Measurement properties of the developed stabilizer and measurement system have been examined during tank studies. Finally, the waveforms obtained during in vivo study are also presented.

Role of IR-Thermal Imaging and Electroimpedance Measurements in Medical Diagnostics

This is a review of the state of the art in two important modalities - thermal and electrical properties of living tissues - that are complementary from the point of view of medical diagnostics. Advantages and limitations of IR thermal imaging and electroimpedance measurements, including tomography procedures are discussed. Properties of both modalities are compared from the point of view of skin burn evaluation, early recognition of breast cancer and some applications in cardiosurgery monitoring.

Reaction of normal and burned tissue to cold excitation

This study is devoted to the question if cold excitation may be effectively used in active dynamic thermal imaging for diagnostics of burn depth. The experiments on animals show quantitatively the reaction of healthy and burned pigskin to forced external cold excitation using cryogenic CO(2) rehabilitation instrumentation. The study allows for comparison of thermal transients at the surface of the pigskin for healthy and burned fields of controlled depths. The results are compared to optical excitation and confirm high value of cold stress in ADT and good correlation of heat flow mechanisms and the state (physiology) of the living skin.

Mild early onset axonal Charcot-Marie-Tooth disease not linked to other axonal Charcot-Marie-Tooth loci

Autosomal dominant axonal Charcot-Marie-Tooth disease type 2 (CMT2) is a heterogeneous group of disorders with seven chromosomal loci mapped in the uncomplicated forms of CMT2. The authors report clinical, electrophysiologic, and genetic analysis of a Polish CMT2 family. Nine known CMT2 gene loci and one MPZ gene locus have been excluded. The authors' findings suggest that this family represents a novel form of CMT2 disease.

A novel MPZ gene mutation in congenital neuropathy with hypomyelination

Congenital hypomyelinating neuropathy (CHN; MIM# 605253) is a severe neuropathy with early infancy onset inherited as an autosomal dominant or recessive trait. Sural nerve biopsy shows a characteristic picture of nonmyelinated and poorly myelinated axons with basal lamina onion bulbs and lack of myelin breakdown products. Several mutations in the MTMR2, PMP22, EGR2, and MPZ genes have been found in patients with CHN. The authors describe the clinical and morphologic features of a patient with CHN and the identification of a novel Thr124Lys mutation in the MPZ gene.

Screening of the myelin protein zero gene in patients with Charcot-Marie-Tooth disease

The myelin protein zero gene (MPZ) coding for the most abundant protein of the peripheral myelin was shown to be mutated in Charcot-Marie-Tooth type 1B disease (CMT1B). Later on MPZ mutations have been shown in axonal type of CMT (CMT2). Recently three novel MPZ gene mutations were reported in congenital hypomyelinating neuropathy (CHN). In contrast to the previously reported studies, focused on CMT1B disease, we aimed to analyze the coding and promoter sequences of the MPZ gene in a group of patients with three CMT phenotypes i.e.: CMT1, CMT2 and CHN. Over 500 PCR products were screened by single strand conformation polymorphism analysis (SSCP) and heteroduplex analysis (HA). In one CMT2 family we founded the E56K mutation in the MPZ gene and in one CHN patient the T124K substitution was detected. In agreement with previously reported studies we conclude that MPZ gene screening should be performed for wide phenotype spectrum of CMT.

Screening of the myelin protein zero gene in patients with Charcot-Marie-Tooth disease

The myelin protein zero gene (MPZ) coding for the most abundant protein of the peripheral myelin was shown to be mutated in Charcot-Marie-Tooth type 1B disease (CMT1B). Later on MPZ mutations have been shown in axonal type of CMT (CMT2). Recently three novel MPZ gene mutations were reported in congenital hypomyelinating neuropathy (CHN). In contrast to the previously reported studies, focused on CMT1B disease, we aimed to analyze the coding and promoter sequences of the MPZ gene in a group of patients with three CMT phenotypes i.e.: CMT1, CMT2 and CHN. Over 500 PCR products were screened by single strand conformation polymorphism analysis (SSCP) and heteroduplex analysis (HA). In one CMT2 family we founded the E56K mutation in the MPZ gene and in one CHN patient the T124K substitution was detected. In agreement with previously reported studies we conclude that MPZ gene screening should be performed for wide phenotype spectrum of CMT.

[Dynamic in vitro measurement of pressure and movement with the LCS prosthetic system]

This study measured the femoral inlay pressure and the movement of mobile bearing inlays after implantation of the LCS knee prosthetic system (DePuy,Warsaw, USA). The prostheses were implanted in seven fresh frozen knee specimens. This system offered three different types of inlays [classic (CL), A/P glide (APG), and rotating platform (ROT)] with the same type of femoral component. A pressure-sensitive film (Tekscan,Boston, USA) was attached on the surface of the inlay.T he movement of the inlay was measured by an ultrasonic positioning system (Zebris, Isny,Germany). The specimens were fixed in a hydraulic knee apparatus simulating an isokinetic extension movement from 120 degrees flexion to full extension. The hydraulic cylinder that simulated the musculus quadriceps femoris extended up to 1200 N. The pressure measurement showed a peak pressure of 4.4+/-1.5 MPa (CL),3.6+/-1.0 MPa (APG),and 9.8+/-1.3 MPa (ROT). The mobile bearing inlays moved 1.4+/-2.7 mm (CL) and 2.9+/-5.8 mm (APG) from posterior to anterior during extension of the knee. During the extension the inlays rotated 0.8+/-2.6 degrees (CL), 0.9+/-5.2 degrees (APG), and 3.2+/-6.9 degrees (ROT) internally.

Potent neutralization of botulinum neurotoxin by recombinant oligoclonal antibody

The botulinum neurotoxins (BoNTs) cause the paralytic human disease botulism and are one of the highest-risk threat agents for bioterrorism. To generate a pharmaceutical to prevent or treat botulism, monoclonal antibodies (mAbs) were generated by phage display and evaluated for neutralization of BoNT serotype A (BoNT/A) in vivo. Although no single mAb significantly neutralized toxin, a combination of three mAbs (oligoclonal Ab) neutralized 450,000 50% lethal doses of BoNT/A, a potency 90 times greater than human hyperimmune globulin. The potency of oligoclonal Ab was primarily due to a large increase in functional Ab binding affinity. The results indicate that the potency of the polyclonal humoral immune response can be deconvoluted to a few mAbs binding nonoverlapping epitopes, providing a route to drugs for preventing and treating botulism and diseases caused by other pathogens and biologic threat agents.

[Nonsurgical treatment of patients with cervical spine pain--algorithm for proceeding]

Diagnosis and treatment of neck pain still remains a therapeutic challenge. Basing on available literature and their own experience the authors present an algorithm for the management of neck pain in daily orthopaedic practice. It is crucial to correlate correctly the patient's complaints, the physical examination and the laboratory findings (including conventional imaging modes and neurodiagnostic procedures). The chronologically organised algorithm should help the physician in find the optimal therapeutic solution for his patient. The use of this algorithm should also lead to a decrease in the number of unnecessarily performed surgical procedures.

[Early results of short segment internal fixation of the thoracic and lumbo-sacral spine after trauma]

The aim of this paper was to assess the results of short-segment internal fixation of the spine in posttraumatic instability. A group of 53 cases of spinal trauma was analysed using both Magerl's and Frankel's classifications. Spinal instability was assessed according the Sagittal Index (SI). The metaanalysis of the clinical material demonstrated that early decompression of the spinal cord and the spinal roots following trauma allows either total or partial restitution of their physiological functions.

[Diskectomy of the lumbar spine: indication and contraindications]

The authors present an overview of the principles of surgical treatment of lumbar disc herniation which are currently applied at spinal surgery ward by the Orthopedic Department of the Poznan School of Medical Sciences. Most of these principles are valid in spinal surgery centres in USA and most European countries. The authors reviewed surgical technique, indications, contrindications and complications related to discectomy in the lumbar spine. Although the articles deals mainly with "classical" discectomy, other surgical techniques (microdiscectomy, percutaneous discectomy, chemonucleolysis, and endoscopy-assisted discectomy) are also briefly reviewed. Careful selection of patients, meticulous analysis of radiographic findings and proper surgical technique yield good results which allow most patients to improve their life conditions and lead a pain-free existence.

Erythromelalgia--a thrombotic complication in chronic myeloproliferative disorders

Erythromelalgia is a very specific, thrombotic syndrome related with thrombocythemia that may occur during the course of chronic myeloproliferative disorders (MPD), especially polycythemia vera (PV) and essential thrombocythemia (ET). This poorly understood clinical syndrome is characterized by red, congested distal extremities and painful burning sensations, usually confined to the ball of the foot and one or more toes or fingers. If left untreated, it may progress towards acrocyanosis and even peripheral gangrene. Sometimes, it may precede the diagnosis of MPD by months or years. The pathophysiological aspects of erythromelalgia as well as its differentiation with erythermalgia have been reviewed in this study.

[Classification of the adolescent idiopathic scoliosis and preoperative strategy]

The authors analysed 841 patients (83% girls and 17% boys) with adolescent idiopathic scoliosis. 678 patients (group I) were treated with the Harrington technique and 163 patients (group II) were treated using multisegmental instrumentation. Follow-up time in group I was on average 14.2 years, and 28 months in group II. Preoperative assessment of patients in group was based on clinical and radiological examination. Assessment of the spine was mainly based on coronal radiogram done in an upright position and lateral side-bending radiograms in a supine position. Traction and lateral X rays were rarely taken into account in this study. The fusion area was decided according to the end vertebrae of the structural curves. The caudal end of the fusion area was identified using Harrington's stable zone. The curves were classified in accordance with the SRS suggestions. Taking into account the apex of the curve, the deformations were classified into: cervico-thoracic, thoracic, thoraco-lumbar, lumbar and lumbo-sacral curves. In group II the triplanar (3D) character of the deformity was taken into account. In the coronal plane the upper and lower stable vertebra of the major structural curves were identified using the CSVL (Central Sacral Vertical Line) based on long films (70 cm x 110 cm) with and without traction. Lumbar curve was classified as mild, moderate, severe according to CSVL. In the axial plane vertebral rotation was assessed according to Nash and Moe method. A careful analysis of lateral radiograms in the upright standing position was performed. Lateral radiograms were performed also in maximal flexion and hyperextension of the spine to obtain a dynamic evaluation of the sagittal plane. Conoral radiograms with maximal rotation of the trunk to assess mobility of the caudad segments of the deformity. Classification of the scoliotic deformity based on its triplanar character included: thoracic curves (King III, IV, V types), double major (thoracic and lumbar), "false" double major curve (thoracic and lumbar) King type II, thoracolumbar/lumbar curves--the main curve is thoracolumbar lumbar/thoracolumbar curves--the main curve is lumbar--10 degrees the thoracolumbar component--King type I triple major curve--all curves have similar structural changes. Correct identification of the type of scoliosis, assessment of structural changes in the frontal, sagittal and axial plane (three dimensional 3D) and analysis of the size and correctiveness of the lumbar curve and all parameters which play a key role in rational preoperative planning. Redefining or at least maintaining lumbar lordosis is far more important than correction of thoracic kyphosis.

[Musculo-skeletal mechanisms of low back pain]

Authors presented in comprehensive form updated knowledge concerning reasons and mechanisms of musculoskeletal back pain nonspecific symptom which in majority of cases, provides only little inside into the nature of the underlying problem. The physician must however find sufficient time to educate the patient as to the nature of this disorder and likely course during treatment. Understanding the source and mechanisms of the patients pain allows the physician and patient to approach the problem rationally with mutual confidence. The basic aim of the physician is exact identification of the anatomic source of pain and exclude the possibility of underlying systemic or malignant process that might threaten the patient's life. The musculoskeletal system consists of the bones and articulations, ligaments, muscles and tendons, that connect and manipulate them within spinal column. All of these tissues are richly innervated and specific biomechanical conditions cause, that lumbar part of the spine and lumbosacral junction are extremely susceptible to direct and indirect affected by a spectrum of reasons causing pain. The pathomechanism of the pain originating within the facet joints, bone and periosteum, paraspinous muscles and tendons, intervertebral disks, posterior longitudinal ligament and dorsal root ganglion was discussed. Although in majority of causes it possible to control localized pain by means of conservative treatment, however in some patients (0.5%-1%) surgery is needed to decompress neurologic structures, restore stability, and eliminate pain.

Impedance mammograph 3D phantom studies

The results obtained using the Technical University of Gdansk Electroimpedance Mammograph (TUGEM) of a 3D phantom study are presented. The TUGEM system is briefly described. The hardware contains the measurement head and DSP-based identification modules controlled by a PC computer. A specially developed reconstruction algorithm, Regulated Correction Frequency Algebraic Reconstruction Technique (RCFART), is used to obtain 3D images. To visualize results, the Advance Visualization System (AVS) is used. It allows a powerful image processing on a fast workstation or on a high-performance computer. Results of three types of 3D conductivity perturbations used in the study (aluminum, Plexiglas, and cucumber) are shown. The relative volumes of perturbations less than 2% of the measurement chamber are easily evidenced.

[Algorithm in low back pain management in adults]

Currently recommended management for low back pain in adults is presented. The algorithm consists of two phases. In a patient presenting acute low back pain with no previous history thorough clinical evaluation (phase I) should aim at exclusion of cauda equina syndrome, fracture, neoplasm, infection, progressive neurological deficit, or chronic pain syndrome. If none of these condition is responsible for low back pain 4-6 weeks therapy depending on the severity of symptoms should be commenced. Then clinical reevaluation is indicated and if pain persists patient should be referred to a specialist (phase II). Previous diagnosis and treatment should be reviewed critically; if found appropriate the treatment might be repeated during phase II. Primary sources of low back pain as herniated nucleus pulposus, unremitting low back pain (segmental instability), spondylolysis, isthmic spondylolisthesis degenerative spondylolisthesis with spinal stenosis should be identified and appropriate treatment (surgical or conservative) undertaken. Patient education is an important component of phase II. In general, phase II of the algorithm aims at returning the patient to full psychophysical activity and at prevention of low back pain recurrence.

[Idiopathic scoliosis: epidemiology and etiology]

Authors present current knowledge about incidence and etiologic factors in idiopathic scoliosis (IS). Most data about incidence are based on screening examination in school children. Amount of patient with IS is related to the method of evaluation and experience of examiner. There is 1.9% to 3% cases in whole population if scoliosis is assumed as much as 10 degrees of Cobb angle (SRS). Etiology of IS is still in doubt despite of many investigations. There are many abnormalities in tissues but most of them probably secondary to this process. Etiology is multifactorial with dominance of inheritance. There are many genes responsible for occurrence of IS but genetic trait is still unknown.

Cell for measurements of biological tissue complex conductivity

The construction of the cell for measurement of complex electric conductivity is described. Two-chamber and four-electrode system with temperature stabilisation is developed. Guarding chamber and electrodes are used to minimise the leakage of current from the measurement chamber. The cell construction is examined by use of Finite Element Method. The model of the measurement cell is examined in order to improve the accuracy of measurements. The calibration procedure based on measurement of reference materials is presented. The frequency range of the cell is extended to 10 MHz with acceptable level of error. The examples of results from measurement breast normal and cancerous tissues are presented.

[Surgical treatment of idiopathic scoliosis with multisegmental posterior instrumentation and its influence on postoperative spinal balance]

Causes of postoperative spinal imbalance in patients with idiopathic scoliosis treated with multisegmental posterior instrumentation CD or TSRH and posterior fusion are presented. Investigation included 88 patients (77 girls, 11 boys) aged 11.4-17.1 (mean 13.8). Primary curve Cobb angle ranged from 52 (to 133 mean 75), secondary curve 16 (to 88 mean 47). Follow-up ranged from 12 to 19 months (mean 18.2 months). In 31 patients (35.2%) postoperative decompensation of the spine occurred. Six of them regained spinal balance within 12 to 19 months postoperatively. As the magnitude of correction increased in relation to preoperative correctiveness and/or preoperative rotation of the spine the imbalance of the spine was more pronounced. It was worsened also in cases where spontaneous correction within the secondary curve (not instrumented) was lesser than expected. Thoracic curve overcorrection in type II scoliosis with instrumentation inclusive of 1 or 2 vertebrae beyond neutral one resulted in decompensation to the left. To short a fusion (in relation to neutral and stable vertebrae) caused in this type as well as in type II and IV right sided decompensation. Overcorrection of lower (right sided) curve or omission of upper (left sided) curve in type V scoliosis caused shoulder girdle decompensation. In type I lumbar fusion done proximally to neutral and stable vertebrae caused left side decompensation of the spine.

[Ethics in tutorial publications]

On basis of scientific literature authors discuss general rules of ethics as the whole of moral rules and behaviour. They point out that compliance with ethical rules in scientific publications should be an integral part of scientific progress. They present the frequent breaches of ethical principles which include: changes or trickery in stating own study results to a priori accepted assumptions, their incorrect presentation or in a more positive mode, taking advantages from other authors publications not revealing its source, lack of sufficient knowledge of scientific literature, theft of foreign scientific ideas, plagiarism and auto plagiarism, unfair presentation of authors sequence in publication, omitting of some co-workers, not in conformity with Helsinki Declaration during human investigations, not in conformity with basic care concerning animals subjected to medical experiments.

[Range of distal spondylodesis in surgical treatment of idiopathic scoliosis using multisegmental instrumentation]

This presentation aim was to provide correct answer in question of range of spondylodesis (both proximal and distal levels) in surgical treatment of idiopathic scoliosis with multisegmental instrumentation. The postoperative evaluation o 88 patients (77 girls and 11 boys) was done according to King and Moe classification. Average patients age was 13.8 years (11.4-17.1) with 18.2 months (12-29) follow-up. In 53 cases it was longer than 2 years. The identification of the curve pattern in both the coronal and sagittal planes will allow you to decide which curves to fuse. In the choice of upper fusion level one should keep attention to shoulder balance and presence of superior junctional kyphosis, extending than range of the fusion up to T2. In the lower level there is important to keep distal fusion mass in vertical alignment transsected by CSL (just like in the upper end in thoracic spine) to preserve spine compensation and remaining as many sa possible mobile spine segments below the fusion.

[The most frequent errors during use of the surgical techniques of Cotrela-Dubousset (C-D) and Texas Scottish Rite Hospital (TSRH) for surgical treatment of idiopathic scoliosis]

Results of operative treatment of idiopathic scoliosis in 88 patients (77 girls and 11 boys) with an average follow-up of 18 months have been presented. Basic principles of surgical procedure and most commonly made errors are demonstrated on the basis of authors' experience and data from the literature. The method of strategic vertebrae selection for hook implantation depending on scoliosis type are discussed. Differences in surgical technique in respect to idiopathic lordoscoliosis or kyphoscoliosis have been highlighted.

[Professor Franciszek Raszeja--a centenary of his birthday]

The authors present a concise biography of professor Franciszek Raszeja on the centenary of his birthday. Special attention is given to his scientific and organizational achievements, particularly in regard to the formation of the Orthopaedic Department at the University of Poznań.

[Autologous blood-derived stem cell transplantation in the treatment of hematopoietic malignant diseases (Part II)]

Autologous transplantation of circulating stem cells is potentially capable of creating a chance of normal hematopoietic reconstitution in the patients in which both allogeneic and autologous bone marrow transplantation was impossible. The authors have reviewed the possibilities for collection of adequate and sufficient numbers of peripheral blood stem cells as well as up-to-date results of their autografting especially in relation to hematopoietic malignant diseases. The advantages resulting from autologous transplantation of circulating stem cells depends on: 1. The lack of risk of GvH--disease. 2. early and rapid hematopoietic and lymphoid recovery, 3. probably, the low risk of graft contamination by tumor cells in early remission.

[Autologous blood-derived stem cell transplantation in the treatment of proliferative disorders of the hematopoietic system (I)]

Peripheral blood can be an alternative source of hematopoietic stem cells which after autografting are capable of sustaining or completely recovering of lymphopoiesis without the necessity of bone marrow harvesting. Theoretical assumptions conditioning the clinical application of circulating stem cells autotransplantation have been described. The results of experimental studies performed in animals and humans have allowed for closer characterization of these cells. However, the physiological significance of their presence in the peripheral blood still remains unknown.

[Torsion and rotation of apical vertebrae and thoracic deformity in idiopathic thoracic scoliosis in computer tomography]

CT examination of 9 patients with primary thoracic right sided scoliosis aged from 13 to 19 years (15 years and 4 months on an average) was carried out. The angle of curvature (Cobb method) ranged from 38 degrees to 99 degrees (68 degrees on an average). Rotation of the apical vertebra was measured and torsion evaluated. Rotation ranged from 5 degrees to 28 degrees (17 degrees on an average). No relation among rotation, angle of curvature and size of the hump was found. The directions of rotation and torsion were opposite. At the apex of curvature due to torsion the end of spinous process was deviated towards the hump but the vertebrae into opposite direction.

[Effect of vitamin E on the function of blood platelets in patients with diabetes mellitus]

An effect of vitamin E on blood platelets functioning was studied in 39 patients with diabetes mellitus type 1. Control group included 20 healthy blood donors. Vitamin E in a daily dose of 1000 mg produced statistically significant decrease in platelets aggregation, number of circulating platelet aggregates and release of the platelet factory 4 in diabetics after 7 days of treatment. No adverse reactions were seen in any patient treated with vitamin E. The obtained results indicate that vitamin E inhibits increased platelets activity in the patients with diabetes mellitus type 1 and does not exert toxic reactions during the treatment.