The effect of selective sst1, sst2, sst5 somatostatin receptors agonists, a somatostatin/dopamine (SST/DA) chimera and bromocriptine on the "clinically non-functioning" pituitary adenomas in vitro.

The aim of the work was to investigate the effects of somatostatin analogs acting selectively on sst1 (BIM-23926), sst2 (BIM-23120) and sst5 (BIM-23206) receptor subtypes on the viability of "clinically non-functioning" pituitary adenomas in vitro. The effects of native SST (SST-14), a SST/DA chimera (BIM-23A387) and a D(2)-dopamine receptor agonist bromocriptine (BC) were also examined. The study was performed on 10 surgically removed pituitary macroadenomas, diagnosed before surgery as "non-functioning". A part of each tumor was mechanically dispersed and digested with collagenase to isolate the tumoral cells. Another part of each tumor was fixed, embedded in paraffin and immunostained to reveal the pituitary hormones and SST receptor subtypes (sst1, sst2A, sst2B, sst3, sst4, sst5). The tumoral cell suspensions were incubated for 24 h with the substances mentioned above. The quantity of viable cells was estimated using the EZ4U system. The results were compared with the immunohistochemical evaluation of the hormonal profile of adenoma and the sst receptor subtype immunoreactivities present. The findings indicate that selective sst1, sst2 and sst5 receptors agonists, SST/DA chimera and D(2)-dopamine receptor agonist bromocriptine affect the viability of some, but not all, "clinically non-functioning" pituitary adenomas in vitro. The most effective was bromocriptine. The investigated somatostatin analogs including SST/DA chimera exerted roughly similar inhibitory effects. Further studies are needed to fully evaluate the potential usefulness of these compounds in the pharmacological treatment of "non-functioning" pituitary tumors.

Human sex reversal due to impaired nuclear localization of SRY. A clinical correlation.

SRY, an architectural transcription factor encoded by the sex-determining region of the Y chromosome, initiates testicular differentiation in mammalian embryogenesis. The protein contains a high-mobility group (HMG) box, a DNA-bending motif conserved among a broad class of nuclear proteins. Mutations causing human sex reversal (46, XY pure gonadal dysgenesis) are clustered in this domain. Basic N- and C-terminal regions of the HMG box are each proposed to provide nuclear localization signals. The significance of the C-terminal basic cluster (SRY residues 130-134) is uncertain, however, as its activity in cell culture varies with assay conditions. To test its importance, we have investigated a C-terminal sex-reversal mutation (R133W, position 78 of the HMG box). This de novo mutation impairs nuclear localization but not specific DNA binding or sharp DNA bending. Correlation between these properties and the phenotype of the patient suggests that nuclear localization of SRY is required for testicular differentiation and directed in part by the C-terminal basic cluster. To our knowledge, these results provide the first example of impaired organogenesis due to a nuclear localization signal mutation.

[Direct fixation of odontoid process base fractures]. / Bezposrednie zespolenie zlaman podstawy zeba kregu obrotowego.

Fractures of the base of odontoid process are serious spinal injuries. Their treatment still remains controversial. External rigid immobilisation is the way of conservative healing. Operations by posterior approach: posterior atlantoaxial fixation, atlantoaxial transarticular screw fixation or even occipitocervical fixation limit range of head motion. Direct odontoid screw fixation preserves normal motion of C1-C2 junction. Success of this method depends on proper patients selection. The authors present description of surgical technique based on literature review and their own experience. The authors perform odontoid fixation by means of single cannulated cancellous screw guided by K-wire. This wire provides stability of broken odontoid process during procedure of screw insertion. Old fracture--1 case in author's experience--has been curetted before fixation. The authors reviewed clinical efficacity and results of direct odontoid screw fixation published in current literature.

[Percutaneous vertebral surgery. Indications, technics and possibilities]. / Przezskórna plastyka kregów. Wskazania, technika i mozliwosci.

UNLABELLED: The authors report their own experience with percutaneous vertebroplasty, one of the so called--minimally invasive methods, used to treat a certain group of spinal lesions affecting the vertebral bodies. The paper contains a brief review of the current literature, basic problems, indications and operative technique. The authors remark, that insertion of the needle into the vertebral body gives an access for biopsy before cement injection. This procedure was realised in the case of diagnostic uncertainty. Technical details of transpedicular biopsy are described. The authors present 2 representative cases. FIRST CASE: a female with pathologic fracture of the Th7 vertebral body of osteoporotic origin. TREATMENT: combination of biopsy and vertebroplasty by percutaneous transpedicular approach. Second case: a female with cancer metastasis in L1 vertebral body, vertebroplasty was performed to support the anterior spinal column. Needle insertion was controlled either by radiofluoroscopy or by CT. The authors confirm pain relief related to vertebroplasty.

SRYand architectural gene regulation: the kinetic stability of a bent protein-DNA complex can regulate its transcriptional potency.

Protein-directed DNA bending is proposed to regulate assembly of higher-order DNA-multiprotein complexes (enhanceosomes and repressosomes). Because transcriptional initiation is a nonequilibrium process, gene expression may be modulated by the lifetime of such complexes. The human testis-determining factor SRY contains a specific DNA-bending motif, the high-mobility group (HMG) box, and is thus proposed to function as an architectural factor. Here, we test the hypothesis that the kinetic stability of a bent HMG box-DNA complex can in itself modulate transcriptional potency. Our studies employ a cotransfection assay in a mammalian gonadal cell line as a model for SRY-dependent transcriptional activation. Whereas sex-reversal mutations impair SRY-dependent gene expression, an activating substitution is identified that enhances SRY's potency by 4-fold. The substitution (I13F in the HMG box; fortuitously occurring in chimpanzees) affects the motif's cantilever side chain, which inserts between base pairs to disrupt base pairing. An aromatic F13 cantilever prolongs the lifetime of the DNA complex to an extent similar to its enhanced function. By contrast, equilibrium properties (specific DNA affinity, specificity, and bending; thermodynamic stability and cellular expression) are essentially unchanged. This correlation between potency and lifetime suggests a mechanism of kinetic control. We propose that a locked DNA bend enables multiple additional rounds of transcriptional initiation per promoter. This model predicts the occurrence of a novel class of clinical variants: bent but unlocked HMG box-DNA complexes with native affinity and decreased lifetime. Aromatic DNA-intercalating agents exhibit analogous kinetic control of transcriptional elongation whereby chemotherapeutic potencies correlate with drug-DNA dissociation rates.

[Stereotactic biopsy and brachytherapy in the diagnostics and treatment of brain tumors--preliminary report]. / Wczesne wyniki zastosowania biopsji stereotaktycznej i brachyterapii w diagnostyce i leczeniu guzów mózgu.

Promising results have been obtained using brachytherapy in the treatment of brain tumors. Between November 99 and August 2000, 28 patients with brain tumors (15 newly diagnosed gliomas, 11 recurrent gliomas, 2 metastases) underwent implantation of temporary iridium 192 sources with stereotactic technique. This group received external beam radiation therapy (45 Gy) following implantation. Patients were followed-up with CT scans every 3 months. Serious complications occurred in two patients (postradiation brain oedema). Median survival has not been assessed due to short follow-up period and small number of patients. Further clinical assessment is required especially long-term follow-up. Brachytherapy appears to be a useful technique for the treatment of selected brain tumors.

[Anterior interbody fusion of cervical spine with case-plate PCB]. / Przednia stabilizacja miedzytrzonowa kregoslupa szyjnego implantem typu cage-plytka PCB--prezentacja przypadków.

Two cases with cervical discopathy and radiculopathy are presented. Discectomy and anterior interbody fusion with cage-plate PCB manufactured by French company Scient'x was performed. Authors present the shape of the implant and technical details of implantation. The paper discusses the advantages of the PCB which simplifies and shortens the operation procedure, minimizes the risk of traditional bone graft harvesting and provides immediate stabilization of the operated segment.

Immediate stiffness of the C5-C6 segment after discectomy with the Cloward technique: an in vitro biomechanical study on a human cadaveric model.

OBJECTIVE: To determine whether the Cloward technique of cervical discectomy and fusion increases immediate postoperative stiffness of single cervical motion segment after application of interbody dowel bone graft. METHODS: We measured and compared the stiffness of single-motion segments in cadaveric cervical spines before and immediately after interbody fusion with the Cloward technique. Changes in range of motion and stiffness of the C5-C6 segment were measured in a bending flexibility test (flexion, extension, lateral bending and axial rotation) before and after a Cloward procedure in 11 fresh-frozen human cadaveric specimens from the 4th through the 7th vertebrae. RESULTS: The Cloward procedure produced a statistically significant increase in stiffness of the operated segment in flexion and lateral bending when compared with the intact spine. The less stiff the segment before the operation, the greater the increase in its postoperative flexural stiffness (statistically significant). The Cloward procedure produced nonuniform changes in rotational and extensional stiffness that increased in some specimens and decreased in others. CONCLUSION: Our data demonstrate that Cloward interbody fusion increases immediate postoperative stiffness of an operated segment only in flexion and lateral bending in cadaveric specimens in an in vitro environment. Thus, Cloward fusion seems a relatively ineffective method for increasing the stiffness of a construct. This may add to discussion on the use of spinal instrumentation and postoperative management of patients after cervical discectomy, which varies from bracing in hard collars through immobilization in soft collars to no external orthosis.

[Intradural spinal cysticercosis provoking radicular symptoms]. / Przypadek wewnatrzoponowej cysticerkozy ogona konskiego z objawami korzeniowymi.

The authors describe a case of spinal intracanal cysticercosis. The cysts were situated intradurally, provoking radicular symptoms: pain, paresis. CT investigations showed herniation of discs L4/L5 and L5/S1 interpreted as the cause of the mentioned symptoms. Surgical treatment included discectomy L4/L5 and L5/S1. Recurrence of symptoms was investigated by means of MRI showing the presence of cysts situated among cauda equina roots. Intraoperative finding--cysticercosis was confirmed by pathologic investigation.

[The case of severe craniocervical dislocation due to rheumatoid arthritis]. / Przypadek powaznej dyslokacji pogranicza czaszkowo-kregoslupowego na tle reumatoidalnego zapalenia stawów.

UNLABELLED: The authors describe a case of craniocervical dislocation secondary to rheumatoid arthritis producing important canal narrowing: ventrally by migrated odontoid and dorsally by posterior arch of C-1 with medullary compression. Symptoms of hyperreflexia, spasticity and left hemiparesis with Babinski sign were present. SURGICAL PROCEDURE: transoral odontoidectomy was performed followed by suboccipital approach, C-1 laminectomy and occipitocervical fixation (Olerud device and bone graft). Outcome with neurologic improvement. CONCLUSIONS: Transoral odontoidectomy combined with occipitocervical decompression and fixation is effective approach for treatment of severe craniocerebral dislocation. Its advantages: ventral and dorsal decompression combined with immediate stabilisation.

[Posttraumatic ectopic calcification as an additional pathologic factor of brachial plexus palsy]. / Pourazowe wapnienie ektopowe jako dodatkowy czynnik patologiczny porazenia splotu ramiennego.

The authors describe a case of a 54-year-old male, who was attacked with a broken bottle and wounded in left supraclavicular region. No neurologic deficit was observed immediately after injury. Some days later signs of upper trunk brachial plexus palsy were detected. Gradually symptoms of the Erb syndrome have developed. He was operated on 5 months after injury. During surgery no discontinuity of the brachial plexus was found. Unexpectedly there were an inner scar and free bony fragment compressing the upper trunk and the suprascapular nerve. Both the scar and bony fragment were carefully dissected and removed. Result of surgery: pain relief, restoration of normal sensation and partial restoration of biceps function.

Mechanical properties of the human brachial plexus.

This study shows measurements of force and elongation during experimental traction of human brachial plexus. Experiments were realised on fresh cadaveric specimens, mechanism of traction injury of brachial plexus was simulated. Predominant lesion provoked by direct lateral traction of isolated brachial plexus was avulsion of the roots. Epineural mechanical failure as first lesion occurred at anterior margin of avulsed roots in the proximity of intervertebral foramen. The force leading to rupture of brachial plexus ranged between 217.7N-546.3N, stress value between 1.3 N/mm2-3.5 N/mm2. Elongation until rupture was 19.6%-58.8% of initial length.

Conception of the cervico-brachial protector for motorcycle drivers.

The increasing popularity of motorcycles increases the role of motorcycle accidents as a main cause of brachial plexus injuries. In view of the high social cost of treatment of the victims it seemed desirable to devise some kind of protective clothing for motorcyclists. The protective clothing devised by teams from Department of Neurosurgery, TRICOTEXTIL--and Aeronautics and Applied Mechanics Institute, consists of the following parts: cervical collar--acting against force causing lateral bending and extension of cervical spine, shock-absorptive shoulder pads--acting against the impact energy partially absorbing it and partially transmitting to the dorsal stiff bar, dorsal stiff bar and sacroiliac belt--partially immobilizes the thoracic and lumbar spine, acts against its compression, transmits the impact energy to the iliac crests and hips. The expected biomechanical effects of the cervico-brachial protector are as follows: In brachial region it should diminish the impact energy by its partial absorption and partial transmission along dorsal stiff bar to sacroiliac belt. It should act against excessive cervical spine motion--mainly against lateral bending and extension. It should act against excessive depression of the shoulder. The protective system built in the jacket should co-operate with the helmet of motorcycle driver. It should be comfortable for the driver and conform to security standards. Prototype of the protector underwent kinetic sledge tests in Industrial Motorization Institute (PIMOT), Warsaw, with the use of Hybrid Dummy II.

Anterior transsternal approach to the upper thoracic spine.

Cervicothoracic junction and upper thoracic spine down to T4 can be reached through anterior approach via sternotomy. Transsternal approach is the best route to gain access to lesions localized within vertebral bodies of the upper thoracic spine allowing for their resection, interbody fusion and replacement with bone cement. Consecutive modifications of transsternal approach evolved towards less extensive osteotomy from full median sternotomy, through manubriotomy with clavicle resection to partial lateral manubriotomy. Less extensive modifications provide limited lateral exposure of the spine and are more demanding technically. We present two cases of the upper thoracic spine tumours operated on through full medial sternotomy. We believe that median sternotomy has several advantages over less extensive modifications: it is technically simple to perform approach for trained thoracic surgeon, safer as it provides better exposure of the mediastinum and thus sufficient control of great vessels including subclavian ones, gives better exposure of T3, T4 and even T5 vertebral bodies, allows perpendicular sight and attack to anterior surface of the upper thoracic spine and therefore good visualizing of the posterior longitudinal ligament and dura, do not destabilize shoulder girdle nor affect function of the upper limb. Additional caudal exposure of the thoracic spine as down as T5 can be obtained by dissecting a plane between the brachiocephalic vein, vena cava superior and ascending aorta.

[Fixating techniques of craniocervical junction: selection criteria]. / Metody stabilizacji pogranicza czaszkowo-kregoslupowego--kryteria doboru.

Adequate choice of fixation technique at craniocervical junction depends on many factors: anatomical conditions at fusion site (e.g. anterior dislocations of the odontoid and rupture of the transverse ligament are contraindications for direct odontoid screw fixation. Sublaminar wiring and interlaminar clamps are useless in case of deficiency of posterior bony elements of C1 and C2 whether a result of laminectomy or destruction), bone quality (osteopenic bone is contraindication for screw techniques either transarticular or transpedicular). Enclosing of occipital bone into instrumentation may be difficult in wire and clamping techniques. In contrast screw techniques allow for easy grip the occipital bone. Screw techniques seem ideal in cases requiring enclosing of the occipital bone. The fusion rate at C1/C2 level seems independent of fixation techniques. When supplemented with external immobilization even biomechanically inferior wiring or interlaminar clamping provide nearly 100 rate of fusion. Screw techniques are technically demanding but they seem the method of choice when occipital bone is to be enclosed in instrumentation.

[Trans-sternal approach to the cervicothoracic junction]. / Dojscie przez mostek do pogranicza szyjno-piersiowego kregoslupa.

Cervicothoracic junction and upper thoracic spine down to T4 can be reached through anterior approach via sternotomy. Transsternal approach is the best route to gain access to lesions localized within vertebral bodies of the upper thoracic spine allowing for their resection, interbody fusion and replacement with bone cement. Consecutive modifications of transsternal approach evolved toward less extensive osteotomy from full median sternotomy, through manubriotomy with clavicle resection and partial lateral manubriotomy. Less extensive modifications provide limited lateral exposure of the spine and are more demanding technically. We present two cases of upper thoracic spine tumours operated on through full medial sternotomy. We believe that median sternotomy has several advantages over less extensive modifications: it is technically simple to perform for trained thoracic surgeon, safer as it provides better exposure of the mediastinum and thus sufficient control of great vessels including subclavian ones, gives better exposure of T3, T4 and even T5 vertebral bodies, allows perpendicular sight and attack to anterior surface of the upper thoracic spine and therefore good visualizing of the posterior longitudinal ligament and dura, do not destabilize shoulder girdle nor affect function of the upper limb. Additional caudal exposure of the thoracic spine as down as T5 can be obtained by dissecting a plane between the brachiocephalic vein, vena cava superior and ascending aorta.

[Screw fixation of craniocervical junction]. / Stabilizacja pogranicza czaszkowo-kregoslupowego srubami.

In recent years an increase has been observed of the use of screw techniques for the fixation of the craniocervical junction. For clinical use two techniques have been introduced: (1) transarticular screw fixation, and (2) transpedicular screw fixation. In the former the screw is inserted through the C2 lateral mass, the fissure of the C1-C2 joint, and the C1 lateral mass. (2) in the latter the screw is inserted into the C2 pedicle and anchored in C2 vertebral body. Transarticular or pedicle screws can be easily connected to longitudinal elements such as rods or plates, and combined with lateral mass screws of the remaining cervical vertebrae or occipital screws. In comparison to sublaminar wiring or interlaminar clamping the screw techniques: (a) strengthen the stiffness of the construct and speed up fusion, (b) allow fixation in the absence or deficiency of laminae as a result of trauma or laminectomy, and (c) can selectively include only the affected segments. Increased construct stiffness is due to deep anchorage of the screw in bone providing thus a solid grip on the vertebra. Both techniques require preoperative assessment of the course of the vertebral artery using imaging methods. In about 18% of cases abnormal course of the artery precludes screw use. Pedicle screw insertion requires direct control of the medial and superior walls of C2 pedicle with dissector introduced into the vertebral canal, which requires removal of the atlantoaxial ligament. Additional control can be achieved with lateral fluoroscopy. The entry point for transarticular screw is on the lateral mass of the odontoid 2-3 mm laterally to the medial margin of C2 facet and 2-3 mm above the C1/C2 articular fissure. The screw trajectory is 0-10 degrees in horizontal plane and towards the anterior C1 tuberculum in sagittal plane.

[The application of intervertebral implant for spine stabilization]. / Zastosowanie wszczepu miedzytrzonowego do stabilizacji kregoslupa.

UNLABELLED: The purpose of this study is determination of efficacy of the SOCON posterior device combined with PROSPACE PLIF interbody fusion system in the treatment of lumbar spondylolisthesis. Both devices are fabricated by Aesculap AG. Lumbar interbody fusion is a surgical technique used to create local spinal stability. Recently there is a wide group of interbody implants made of different osteoconductive materials. The authors present brief classification of lumbar interbody fusion implants. The 1 case of spondylolisthesis L5/S1 is analyzed including operative technique and outcome. CONCLUSION: PROSPACE is effective as interbody support and fusion element.

[Diagnostic difficulties in a case of multifocal changes in the brain in computerized tomography and in magnetic resonance imaging]. / Trudnosci diagnostyczne w przypadku wieloogniskowych zmian mózgu w obrazie tomografii komputerowej i rezonansie magnetycznym.

This paper presents a case of multifocal metastases in the brain, which on the basis of typical imaging magnetic resonance and computerized tomography suggested possible parasitic changes (cerebral cysticercosis). On the basis of these pictures cerebral cysticercosis was diagnosed, in spite in the absence of serologic changes in blood and cerebrospinal fluid. The lack of improvement after anticysticercosis drugs, the further course of the disease as well as new foci located in other organs outside the brain, allowed to recognize numerous metastases in the brain although until the end of the clinical observation the primary lesion of the neoplasm was not found. The histopathological examination of samples of brain tissue confirmed the diagnosis of numerous metastases of poorly differentiated carcinoma.

[Lumbar interbody fusion. Biomechanical significance for the spine]. / Spondylodeza miedzytrzonowa kregoslupa ledzwiowego. Znaczenie dla biomechaniki kregoslupa.

The authors discuss the significance of interbody fusion for early and long term stability of the lumbar spine. They stress that the aim of the modern spinal instrumentation is to promote bone healing and not to replace fusion. Without fusion every stabilization device will fail in fatigue. The biomechanics of different types of spinal fusion and biomechanical conditions at fusion site are discussed. A history of lumbar interbody fusion including threaded implants (cages) is presented. Interbody cages combine positive properties of tricortical bone graft: the strength of cortical to the bone with improved incorporation properties of cancellous bone. In contrast bone graft their biomechanical performance is far better: they increase strength and stability of osteosynthesis, do not go collapse and resorption, prevent from decrease in disc space height and kyphotic angulation of the fused motion segment, require less bone to achieve fusion. They can be used solely without support of any stabilization system. Preliminary experience in fusion with interbody threaded implants suggest significant efficacy of this method.