Biomedical subjects

Andrzej Radek

Publications and source records attributed to Andrzej Radek.

10 recordsLinked to original sources

PubMed2006

Proliferating cell nuclear antigen (PCNA) expression in pituitary adenomas: relationship to the endocrine phenotype of adenoma.

The expression of proliferating cell nuclear antigen (PCNA) correlates to cell proliferation and for this reason it is commonly considered as one of proliferation markers. Since proliferation rate is an important factor determining the tumor aggressiveness, the evaluation of PCNA index (the percentage of PCNA-immunopositive nuclei in the investigated tumor sample) is suggested as useful in predicting pituitary adenoma outcome. Seventy three unselected, surgically removed pituitary adenomas were immunostained with antibodies against the pituitary hormones or their subunits and against the proliferating cell nuclear antigen (PCNA). The highest PCNA index was found in ACTH-immunopositive tumors without the manifestation of the Cushing's disease ("silent" corticotropinomas). This value was significantly different in comparison to other adenoma subtypes including corticotropinomas manifesting themselves by Cushing's disease. The lowest PCNA index was noticed in monohormonal GH-secreting tumors. The adenomas which express more than one hormone (plurihormonal adenomas) seem to have a higher PCNA indices than monohormonal ones; the difference was significant in the case of mono- and plurihormonal prolactinomas. The recurrent tumors presented a higher mean PCNA index as compared to the primary tumors, although the difference was significant only in the case of prolactinomas. These findings suggest that the proliferative potential of pituitary adenomas is related to the tumor recurrence and hormone expression.

Adenoma↗

PubMed2005

Experimental investigations of traction injury of the brachial plexus. Model and results.

AIM: The study was realized in purpose to investigate mechanical properties of the human brachial plexus. Authors present model of experiments and biomechanical results obtained after controlled stretching of specimens. Investigations were supported by Polish Ministry of Education (Grant KBN 3 P05C 072 22), under permission of Committee of Bioethics. MATERIAL AND METHODS: Thirty specimens isolated from cadavers were distracted with a speed 20 cm/min. Mechanical tests were realised by means of apparatus INSTRON 4000. During stretching following data were registered: maximal force provoking mechanical failure of specimen and elongation in the point of mechanical failure. Stiffness of the brachial plexus was also calculated. Anatomic investigations were realised in purpose to define the most frequent type of lesion. RESULTS: The mean value of force leading to rupture of human brachial plexus was 630 N. The mean value of elongation in the point of rupture was 37%.

Adult↗

PubMed2005

[Middle ear schwannoma--case report].

Schwannoma is one of the common benign middle ear space tumors. The tumors may present with facial nerve paresis or palsy, otologic symptoms and/or parotid mass middle ear schwannomas may originate from the nerves of the tympanic caviti or by extensions from outside the middle ear space. Schwannomas of the facial nerve can occur along any segment, but they frequently involve the geniculate ganglion and extend proximally or distally from there. MRI and CT imaging characteristics are similar to those of vestibular schwannomas. We present the clinical and radiologic features of a middle-space schwannoma originating from facial nerve. The patient underwent middle ear exploration and mastoidectomy. The tumor was of facial nerve origin and was separated from middle ear. The pathologic diagnosis was schwannoma.

Adult↗

PubMed2003

Immunohistochemical detection of somatostatin receptor subtypes in "clinically nonfunctioning" pituitary adenomas.

Pituitary tumors diagnosed before surgery as "non-functioning" in fact represent a heterogenous group, the majority of which express glycoprotein hormones or their free subunits. It is known that some of them expresses somatostatin receptors, but the data available until now rarely refer to the receptor subtype. Five different subtypes of somatostatin receptors (sst1-5) have been cloned. We studied 18 pituitary tumors diagnosed before surgery as "non-functioning." After the surgery the tumors were immunostained with antibodies against pituitary hormones and alpha subunit as well as with antibodies against the somatostatin receptor proteins 1-5. Thirteen adenomas expressed immunoreactivity for FSH, LH, and/or alpha subunit and were classified as gonadotroph adenomas. The remaining five adenomas were immunonegative for all the examined pituitary hormones and were diagnosed as null cell adenomas. All the adenomas of both the groups showed immunopositivity for at least three receptor subtypes. The strongest immunopositivity was found in both groups with anti-sst1 and anti-sst5 antibodies. The marked immunopositivity was also revealed in both groups with anti-sst2B antibody. On the other hand, the sst2A immunopositivity was weak or absent in a majority of tumors. The main difference between two groups was in the sst4 receptor subtype which was absent in all but two gonadotroph adenomas but present in all but one null cell adenoma. These findings suggest that "non-functioning" pituitary adenomas are potential candidates for therapy with somatostatin analogs targeted mainly to the receptor subtypes 1 and 5.

Adenoma↗

PubMed2003

[Post-traumatic unilateral atlanto-axial rotatory subluxation in an adult].

This retrospective single-patient case report deals with a rare form of spinal trauma, i.e. atlantoaxial rotatory subluxation. The authors present a review of the literature including a classification of rotatory atlantoaxial subluxation types proposed by Fielding, and describe their own experience with treatment of this condition. A case is reported of a 29-year-old woman with a history of head contusion in a car accident. Immediately after the trauma she had the following symptoms: torticollis and neck pain with decreased cervical motion. Atlantoaxial rotatory subluxation of the right C1-C2 articulation was diagnosed by plain radiographs and CT. The patient was treated surgically by an open reduction, unilateral screw fixation of the right CI-C2 articulation (according to Magerl) and posterior C1-C2 wiring with graft. The normal atlantoaxial relation was restored with disappearance of torticollis. At follow-up certain limitation of neck movements due to C1-C2 stabilization persisted. No complications were noted. The patient remains neurologically intact and has radiographic documentation of fusion.

Adult↗

PubMedDate not supplied

[Problems in the selection of surgical approach for the treatment of non-traumatic deformities of the craniocervical junction].

Developmental abnormalities or inflammatory disorders provoke deformations and instability of the craniocervical junction. The most dangerous results of these lesions are: sudden brainstem compression or cervical myelopathy. The authors propose the guidelines for surgical management of non-traumatic deformities caused by: a) rheumatoid arthritis of the spine, b) congenital anatomic changes of the occipit and odontoid. Main goals of surgical treatment are decompression and stabilization. The choice of surgical approach and method depends on pathology. It is very important to estimate individual anatomic changes and mobility--possibility of reduction. The authors discuss surgical methods actually used for fusion and decompression of the occipitocervical junction.

Arthritis, Rheumatoid↗

PubMedDate not supplied

[Brachial plexus tumors].

The brachial plexus is a primary site of tumours originating from peripheral nervous system, such as neurilemmoma and neurofibroma. Moreover, the brachial plexus is affected by various neoplasms spreading from the neighbouring anatomic structures. Surgical treatment of neoplasms provoking plexopathy is often realised by multidisciplinary teams. The authors present the series of 7 patients operated on for brachial plexus affection between 1993-2000, the pathologic findings were as follows: neurofibroma, neurilemmoma, lymphogranulomatosis, neurofibrosarcoma, lipoma, chordoma, sarcoma neurogenes. The analysis of clinical course includes: main symptoms, diagnostic procedures and results of treatment. Surgical technique is also described.

Adult↗

PubMedDate not supplied

[Atlanto-occipital instability due to the transverse atlas ligament rupture. Report of a case with symptoms persisting for 21 years].

The authors describe a case of a judo sportsman with a cervical spine injury sustained 21 years earlier. The injury initiated characteristic sensations of severe generalized pain with paraesthesias recurring whenever he was hit on the top of the head. In February 2001 the patient fell on his head, which resulted in tetraplegia with a complete sensory loss. The symptoms disappeared after ten minutes. Plain radiography, CT and MRI performed after this episode revealed occipitalization of the atlas and C1-C2 instability due to a rupture of the transverse atlas ligament. The patient underwent surgery by the posterior approach: decompression of the foramen magnum, fixation of the occiput and C-2 (with wiring and a bone graft). At one-year follow-up after the surgery the patient had limited movements of the neck without neurological symptoms. Plain radiograms confirmed stability of the occipitocervical fusion. There was no recurrence of the preoperative symptoms.

Adult↗

PubMedDate not supplied

[Direct fixation of the odontoid fracture in a child].

The use of spinal implants in the pediatric population is controversial in terms of skeletal immaturity. The authors present the case of a 12-year-old boy with displaced Type III odontoid fracture, successfully treated by direct screw fixation. Fractures defined as Type II and Type III according to the classification by Anderson and D'Alonzo are instable spinal injuries. Type III fractures generally heal when treated conservatively. In certain circumstances, like displaced fractures or patients refusing long-term external immobilization, Type III fractures are treated surgically. A 12-year-old boy had neck injury caused by a bike accident. His main symptoms were neck pain and limitation of neck movements. Displaced Type III odontoid fracture was diagnosed. The authors treated this lesion surgically by screw fixation in order to correct displacement and to preserve the normal range of head motion. Fixation was performed by means of a single cannulated screw. Healing of the fracture was confirmed by roentgenograms done at follow-up examinations. The range of motion of the cervical spine examined 6 months after operation was normal. Direct anterior screw fixation was an effective method for treating displaced Type III odontoid fracture in a child. The rotatory motion between C-1 and C-2 was preserved.

Bicycling↗

PubMedDate not supplied

[Minimally invasive percutaneous transpedicular lumbar spine fixation. Operative technique and a case report].

Transpedicular fixation systems are commonly used in lumbar spine surgery for the treatment of a variety of pathologies making the solid fusion of operated spinal segments possible. Recently there has been a big interest in minimally invasive techniques in spinal surgery, including minimally invasive fixation systems. By minimizing the operative trauma minimally invasive techniques allow patients to restore activity faster. In the paper the authors present the Sextant system (Medtronic Sofamor Danek), which provides minimally invasive (percutaneous) fixation. Before fixing the spine, it is necessary to perform discectomy and interbody fusion using the PLIF or ALIF method. The authors present the system, describe the operative technique, and present a case of the patient with L4/L5 spondylolisthesis successfully treated using this technique.

Adult↗