Pineal gland calcification under hypoxic conditions.

The pineal gland (glandula pinealis) is neuroendocrine gland located at the epithalamus of the brain secreting melatonin. The aim of this study was to explore effects of prenatal hypoxia in rats at the age of 33 weeks on the occurrence of pineal gland calcification. Distribution and chemical composition of calcerous material by light, scanning and transmission electron microscopy was investigated. Melatonin concentrations in blood plasma by direct radioimmunoassay were measured. Rats were exposed to prenatal hypoxia for 12 h at day 20 of development and second group to prenatal hypoxia for 2x8 h at days 19 and 20 of development. Vacuoles of intracellular edema in the pineal samples after 12 h hypoxia were found. Their size ranges up to 30 µm. Some of them were filled with the flocculent and fibrous material. Samples of pineal glands after 2 x 8 h hypoxia revealed the pericellular edema of pinealocytes. The amount of calcium rich particles in 2 x 8 h hypoxia group was lower than in 12 h hypoxia group. Plasma melatonin levels did not differ between control and both hypoxia groups. We concluded that calcification is a process induced by osteoblasts and osteocytes with melatonin as a promotor and it is favored under hypoxic conditions.

[Total and unicompartmental knee replacement. Patient-specific Instrumentation]. / Uni- und bikondylärer Oberflächenersatz. Patientenspezifische Instrumentierung.

BACKGROUND: The objective of patient-specific instrumentation (PSI Zimmer®) technology is to optimize positioning and selection of components as well as surgical procedure in uni- and bicompartimental knee replacement. The article contains a description of the planning and surgical technique and evaluates the method based on own results and literature. METHODS: Using MRI or CT scans a virtual 3D model of the joint is created in order to simulate and plan the implant positioning. According to these data, pin placement and/or cutting guides are produced, which enable the surgeon to transfer the planning to the surgical procedure. In a prospective comparative study 88 patients (44 per each of the two techniques) were operated by one surgeon receiving the same TKA using either MRI-based PSI or a conventional technique. The number of surgical trays, operating time, intraoperative changes and frontal alignment using a full leg x­ray (70 cases) were compared. In 17 patients the method was applied with unicondylar knee replacement. RESULTS: Anatomical abnormalities could be detected preoperatively and considered during the operation. With PSI the number of trays could be reduced and predictability of the component size was more precise. Intraoperative changes became necessary only for distal femoral (25 %) and proximal tibial (36 %) resection and tibial rotation (40 %). Alignment was more precise in the PSI cases DISCUSSION: PSI using the applied technique proved to be practicable and reliable. The advantages of precise planning became obvious. Results concerning alignment are inconsistent in the literature. Soft tissue balancing has only been included in the technique to a limited degree so far. PSI is still in an early stage of development and further development opportunities should be exploited before final assessment.

Iron-rich complexes in human spleen in hereditary spherocytosis.

OBJECTIVE: Tissue iron plays an important role in the development of certain diseases. Although it is one of biogenic elements, its excess induces the reactive oxygen species (ROS) formation. The aim of the present work is to examine the protection against free or loosely bound iron from the view of morphology and chemical composition of iron-rich complexes in human spleen tissues with hereditary spherocytosis (HS) by scanning and transmission electron microscope with energy-dispersive microanalysis (EDX). RESULTS: The examination of human spleen tissues by scanning and transmission electron microscope showed covering of iron-rich particles. EDX revealed many iron-rich complexes of multi-element composition in HS samples with sulphur and phosphorus as the major elements. Detection was negative in the reference samples. CONCLUSION: The covering of iron-rich particles can be explained by elimination and isolation of ferritin/iron complexes from surrounding environment to prevent the ROS formation. Sulphur, phosphorus and their compounds are probably the most significant elements that influence the ROS formation (Fig. 5, Ref. 16). Full Text in PDF www.elis.sk.

Iron accumulation in human spleen in autoimmune thrombocytopenia and hereditary spherocytosis.

BACKGROUND: Although the iron is an essential element for the physiological functions of cells, tissues and organs, it is also an important inductor of reactive oxygen species (ROS). MATERIAL AND METHODS: Three groups of human spleen with autoimmune thrombocytopenia (AITP), hereditary spherocytosis (HS) and reference samples stained by haematoxylin and eosin, Perls' reaction for nonheme Fe(III) iron and Alcian blue for glycoconjugates detection were studied. RESULTS: Positive Perls' reaction in both AITP and HS groups was seen. Higher positivity in the HS than in AITP group was observed. HS group showed a higher amount of acidic glycoconjugates deposits than AITP group. Iron overload in HS and AITP leads to overproduction of ROS. CONCLUSION: We suggest that acidic glycoconjugates deposits are involved in antioxidant defence by elimination and restriction of iron as a ROS inducer (Fig. 4, Ref. 19).

Angiomyofibroblastoma of the cervix uteri: a case report.

BACKGROUNDS: Angiomyofibroblastoma (AMFB) is a rare histopathologic finding of the female lower genital tract. This tumor belongs to the group of mesenchymal tumors. Mesenchymal neoplasms of the modified genital skin and mucosa are uncommon. The majority of these lesions are seen in females and, collectively, they form a family of vulvovaginal soft tissue tumors. This family includes fibroepithelial stromal polyps, angiomyofibroblastoma, cellular angiofibroma, aggressive angiomyxoma, vaginocervical myofibroblastoma, vulvar leiomyomatosis, and other smooth muscle tumors. Angiomyofibroblastoma is a benign tumor, histologically very similar to pelvic aggressive angiomyxoma (AMM), a distinctive, locally infiltrative but non-metastasizing mesenchymal neoplasm with a tendency to occur in the female pelvic and perineal regions. CASE: 44 years old woman with angiomyofibroblastoma of cervix uteri. CONCLUSION: A recognition of this entity is important to avoid misdiagnosis of other angiomyxoid neoplasms. Furthermore, unlike other, more aggressive, mesenchymal tumors of the lower genital tract, AMFB shows benign behaviour.

[Significance of the sentinel lymph node biopsy in early breast carcinomas]. / Význam biopsie sentinelovej uzliny pri vcasnom karcinóme prsníka.

We present our experience regarding sentinel lymph node biopsy (SLNB) at St. Elizabeth Institute of Oncology during 48 months. From January 1st, 2006 until December 31st, 2009, we had performed SLNB in 269 patients. Primary tumour size was 0.3-3.5cm including non-invasive breast carcinoma (i.e. TIS, T1 and T2 of TNM classification). Invasive carcinoma accounted for 255 (94.8%) cases, while non-invasive carcinoma for 14 (5.2%) cases. From total of 269 patients with invasive carcinoma, we used validation method in 157 (72.7%). In 255 patients with invasive carcinoma, sentinel node was not identified in 4 (1.6%) cases--in 1 patient with T1 invasive carcinoma and in 3 patients with T2 tumours. False negativity of sentinel node in T1 tumours was 4.3%. The incidence of macrometastases in sentinel nodes was confirmed using standard histopathologic examination with hematoxylin-eosin stain. In negative instances, the examination was then completed with serial sections and immunohistochemistry using cytoskeletal antibodies for confirmation of presence of micrometastases. In 6 (2.4%) cases, we found micrometastase in originally negative sentinel lymph node. Subsequent axillary dissection has not confirmed non-sentinel nodes involvement.

Phe and Asn side chains in DNA double strands.

The contribution of amino acid side chains to the recognition of DNA by peptides or proteins is evaluated by substituting single nucleobases of a DNA double strand by amino acid side chains. C-nucleosides with the side chains of phenylalanine and asparagine were synthesized and incorporated in DNA. This modification should allow to keep the double strand conformation. Hydrogen bonds, pi-pi-interactions and solvation have an influence on the double strand stability.

Viscoelastic relaxation and regional blood flow response to spinal cord compression and decompression.

STUDY DESIGN: To better understand the relationships between primary mechanical factors of spinal cord trauma and secondary mechanisms of injury, this study evaluated regional blood flow and somatosensory evoked potential function in an in vivo canine model with controlled velocity spinal cord displacement and real-time piston-spinal cord interface pressure feedback. OBJECTIVES: To determine the effect of regional spinal cord blood flow and viscoelastic cord relaxation on recovery of neural conduction, with and without spinal cord decompression. SUMMARY OF BACKGROUND DATA: The relative contribution of mechanical and vascular factors on spinal cord injury remains undefined. METHODS: Twelve beagles were anesthetized and underwent T13 laminectomy. A constant velocity spinal cord compression was applied using a hydraulic loading piston with a subminiature pressure transducer rigidly attached to the spinal column. Spinal cord displacement was stopped when somatosensory evoked potential amplitudes decreased by 50% (maximum compression). Six animals were decompressed 5 minutes after maximum compression and were compared with six animals who had spinal cord displacement maintained for 3 hours and were not decompressed. Regional spinal cord blood flow was measured with a fluorescent microsphere technique. RESULTS: At maximum compression, regional spinal cord blood flow at the injury site fell from 19.0 +/- 1.3 mL/100 g/min to 12.6 +/- 1.0 mL/100 g/min, whereas piston-spinal cord interface pressure was 30.5 +/- 1.8 kPa, and cord displacement measured 2.1 +/- 0.1 mm (mean +/- SE). Five minutes after the piston translation was stopped, the spinal cord interface pressure had dissipated 51%, whereas the somatosensory evoked potential amplitudes continued to decrease to 16% of baseline. In the sustained compression group, cord interface pressure relaxed to 13% of maximum within 90 minutes; however, no recovery of somatosensory evoked potential function occurred, and regional spinal cord blood flow remained significantly lower than baseline at 30 and 180 minutes after maximum compression. In the six animals that underwent spinal cord decompression, somatosensory evoked potential function and regional spinal cord blood flow recovered to baseline 30 minutes after maximum compression. CONCLUSIONS: Despite rapid cord relaxation of more than 50% within 5 minutes after maximum compression, somatosensory evoked potential conduction recovered only with early decompression. Spinal cord decompression was associated with an early recovery of regional spinal cord blood flow and somatosensory evoked potential recovery. By 3 hours, spinal cord blood flow was similar in both the compressed and decompressed groups, despite that somatosensory evoked potential recovery occurred only in the decompressed group.

Geographic variation in the prevalence of Raynaud's phenomenon: a 5 region comparison.

OBJECTIVE: To determine the population based prevalence of Raynaud's phenomenon (RP) in 5 geographic regions: one in South Carolina, USA, and 4 in France; to explore the relationship of RP to the climate; to investigate possible risk factors; and to describe the characteristics of RP+ subjects in the general population. METHODS: The study consisted of 2 phases: a telephone survey of a randomly drawn sample of households, with 10,149 completed interviews; these were followed by a face to face interview and clinical evaluation (n = 1,534), including diagnosis of RP. The same methodology was used in all 5 regions: for recruitment of subjects, criteria for RP, method of RP diagnosis, and for gathering additional information. RESULTS: The prevalence of RP was found to be related to the climate. The relationship between RP and climate was complicated, however, by the fact that many subjects had moved between climate zones. The relationship of RP to a cold climate became more evident after taking the migration patterns into account: the majority of RP+ subjects in the 2 coldest regions had lived all their lives in the same or a similar climate zone; the majority of RP+ subjects in the 2 warmest regions had previously lived in a colder climate. Other factors associated with RP were family history of RP, cardiovascular diseases, older age, a low body mass index, use of vibrating tools, and outings of a day or more. The classical triphasic RP was rarely encountered in the general population and the most frequently observed signs and symptoms during an RP attack were blanching accompanied by numbness. CONCLUSION: In addition to being a triggering factor for RP attacks, cold also appears to be an etiologic factor in the pathogenesis of RP. A subclinical cold injury, more likely to occur in colder climates, may be responsible for the "local fault" that has been implicated in the pathogenesis of RP and, in association with other risk factors, may predispose subjects to develop clinical RP.

Early time-dependent decompression for spinal cord injury: vascular mechanisms of recovery.

Although surgical decompression is often advocated for acute spinal cord injury, the timing and efficacy of early treatment have not been clinically proven. Our objectives were to determine the importance of early spinal cord decompression on recovery of evoked potential conduction under precision loading conditions and to determine if regional vascular mechanisms could be linked to electrophysiologic recovery. Twenty-one mature beagles were anesthetized and mechanically ventilated to maintain normal respiratory and acid-base balance. Somatosensory-evoked potentials from the upper and lower extremities were measured at regular intervals. The spinal cord at T-13 was loaded dorsally under precision loading conditions until evoked potential amplitudes had been reduced by 50%. At this functional endpoint, spinal cord displacement was maintained for either 30 (n = 7), 60 (n = 8), or 180 min (n = 6). Spinal cord decompression was followed by a 3-h monitoring period. Regional spinal cord blood flow was measured with fluorescent microspheres at baseline (following laminectomy) immediately after stopping dynamic cord compression, 5, 15, and 180 min after decompression. Within 5 min after stopping dynamic compression, evoked potential signals were absent in all dogs. We observed somatosensory-evoked potential recovery in 6 of 7 dogs in the 30-min compression group, 5 of 8 dogs in the 60-min compression group, and 0 of 6 dogs in the 180-min compression group. Recovery in the 30- and 60-min groups varied significantly from the 180-min group (p < 0.05). Regional spinal cord blood flow at baseline, 21.4+/-2.2 ml/100/g/min (combined group mean +/- SE) decreased to 4.1+/-0.7 ml/100 g/min after stopping dynamic compression. Reperfusion flows after decompression were inversely related to duration of compression. Of the 7 dogs in the 30 min compression group, 5 min after decompression the blood flow was 49.1+/-3.1 ml/100 g/min, which was greater than two times baseline. In the 180-min compression group early post-decompression blood flow, 19.8+/-6.2 ml/100 g/min, was not significantly different than baseline. Of the 8 dogs in the 60-min compression group, 5 who recovered evoked potential conduction revealed a lower spinal cord blood flow sampled immediately after stopping dynamic compression, 2.1+/-0.4 ml/100 g/min, compared to the 3 who did not recover where blood flow was 8.4+/-2.1 ml/100 g/min (p < 0.05). Reperfusion flows measured as the interval change in blood flow between the time dynamic compression was stopped to 5, 15, or 180 min after decompression, were significantly greater in those dogs that recovered evoked potential function (p < 0.05). Three hours after decompression, spinal cord blood flow in the 3 dogs in the 60-min compression group with no recovery, 11.1+/-2.1 ml/100 g/min, was significantly less than the spinal cord blood flow of the recovered group (n = 5), 20.5+/-2.2 ml/100 g/min. These data illustrate the importance of early time-dependent events following precision dynamic spinal cord loading and sustained compression conditions. Spinal cord decompression performed within 1 h of evoked potential loss resulted in significant electrophysiologic recovery after 3 h of monitoring. This study showed that the degree of early reperfusion hyperemia after decompression was inversely proportional to the duration of spinal cord compression and proportional to electrophysiologic recovery. Residual blood flow during the sustained compression period was significantly higher in those dogs that did not recover evoked potential function after decompression suggesting a reperfusion injury. These results indicate that, after precise dynamic spinal cord loading to a point of functional conduction deficit (50% decline in evoked potential amplitude), a critical time period exists where intervention in the form of early spinal cord decompression can lead to effective recovery of electrophysiologic function in the 1- to 3-h post-decompression p

Intraoperative improvements of somatosensory evoked potentials: correlation to clinical outcome in surgery for cervical spondylitic myelopathy.

STUDY DESIGN: Retrospective review of all patients who underwent surgical treatment of cervical spondylitic myelopathy and were monitored by somatosensory evoked potentials. OBJECTIVES: To identify the patients who had recognizable improvements in somatosensory evoked potential signals intraoperatively and to correlate the changes in somatosensory evoked potential signals to the post-operative clinical status of the patients and compare this group of patients with those that had stable intraoperative somatosensory evoked potential recordings. SUMMARY OF BACKGROUND DATA: Somatosensory evoked potentials are commonly used in the operating room to monitor potential injury to the spinal cord or alterations in spinal cord function. It may be possible to use intraoperative somatosensory evoked potentials to detect improvement in spinal cord function during the decompression of neural structures, as evidenced by an increase in amplitude or a decrease in the latency of the wave form. METHODS: Thirty-two patients with moderate to severe cervical spondylitic myelopathy requiring multi-level anterior decompression and fusion were monitored intraoperatively with somatosensory evoked potentials. The median and posterior tibial nerves were stimulated at the wrist and ankle, respectively. Somatosensory evoked potential recordings were obtained from cervical and scalp electrodes by the Nicolet Pathfinder electrodiagnostic system, preoperatively, intraoperatively, and postoperatively. RESULTS: Eleven of thirty-two patients demonstrated intraoperative improvement of somatosensory evoked potential signals after decompression. All patients had rapid recovery of motor strength, bladder control, and ambulatory capacity within days of surgery. The remaining twenty-one patients had stable somatosensory evoked potential recordings. Five had rapid resolution of their symptoms, 15 improved over the course of 6 to 8 weeks, and 1 did not improve. The motor recovery of this group at 8 weeks was equal to the group of patients that showed intraoperative improvements of evoked potential signals. CONCLUSIONS: 1) Multilevel anterior cervical decompression and fusion produced a significant improvement in the motor function of patients with cervical spondylitic myelopathy. 2) Patients with intraoperative increase in amplitude or shortening of latency had a more rapid clinical improvement than patients with stable recordings. 3) Long-term reassessment did not show any difference between patients with intraoperative somatosensory evoked potential improvement and those with stable somatosensory evoked potential recordings. Therefore, somatosensory evoked potential improvements cannot be used to determine prognosis at the present time. 4) A greater number of patients should be studied using more objective methods for quantifying gait patterns and motor function.

Axon regeneration after decompression of the conus medullaris.

STUDY DESIGN: The effect of acute spinal stenosis (simulating fracture) and decompression of stenosis on axon regeneration was evaluated in an animal model. OBJECTIVES: Clinical function and quantitative histomorphometry were used to gain insight into the clinicopathologic effects of acute spinal stenosis and decompression. SUMMARY OF BACKGROUND DATA: Decompression of extrinsic compression after thoracolumbar fractures has been suggested to maximize recovery of neurologic function. Clinical studies seem to support this, but the histologic results of decompression are poorly understood. METHODS: Experimental spinal stenosis was created in 5 female beagle dogs, followed by decompression in three of the beagles at 6 weeks. Clinical function and histologic appearance were analyzed using a monoclonal antibody to neurofilaments. RESULTS: Stenosis consistently produced significant neurologic deficit and axon degeneration within motor roots distal to the stenosis. Decompression resulted in improved neurologic function and a tendency for the axons to return to normal number and volume based on quantitative histomorphometry. CONCLUSION: This study provides an animal model and functional and histologic data that support the use of decompression of acute spinal stenosis of 50% or more canal compromise at the level of the conus medullaris and a neurologic deficit. This may be seen clinically in thoracolumbar fractures.

Urologic function after experimental cauda equina compression. Cystometrograms versus cortical-evoked potentials.

Twenty female beagle dogs underwent an L6-7 laminectomy and six dogs each had 25, 50 or 75% constriction of the cauda equina and 2 control dogs had laminectomy only. Cystometrograms were performed pre- and post-operatively and three months after constriction. Cortical evoked potentials were monitored pre- and post-operatively and monthly for three months. After three months of constriction, the cauda equina of these dogs in each group was examined histologically and vascular circulation was examined by latex and India ink injection (Spalteholz technique). The control dogs had normal CMGs and CEPs. Twenty-five percent constriction caused no CMG changes and mild CEP changes. Fifty percent constriction caused no statistically significant CMG changes, major CEP changes and venous congestion of the nerve roots and dorsal root ganglia. Seventy-five percent constriction produced severe CMG changes with detrusor areflexia, increased bladder capacity and clinical incontinence. CEPs also had marked deterioration. Vascular analysis revealed severe arterial narrowing at the level of constriction and venous congestion of the nerve roots and dorsal root ganglia. Blockage of axoplasmic flow and nerve root atrophy was seen in all dogs with 75% constriction. Cortical evoked potentials were the most sensitive predictor of neural compression. CMGs were not sensitive until severe compression was achieved. Bladder dysfunction, i.e., detrusor areflexia, appears to occur with blockage of axoplasmic flow and early sensory changes occur with neurovenous congestion.

Experimental lumbar spinal stenosis. Analysis of the cortical evoked potentials, microvasculature, and histopathology.

An animal model of lumbar spinal stenosis was developed in which the pathophysiology of this condition could be examined. Four experimental groups, each containing six dogs, were studied. One group had a laminectomy of the sixth and seventh lumbar vertebrae only; these animals served as controls. In the three other groups, a laminectomy was performed and the cauda equina was constricted by 25, 50, or 75 per cent to produce chronic compression. Cortical evoked potentials were recorded preoperatively, immediately after constriction, and at one, two, and three months postoperatively. Daily neurological examinations were carried out, and the neurological deficits were graded using the Tarlov system. After three months of constriction, the cauda equina of three dogs in each group was examined histologically, and the vascular circulation was examined by latex and India-ink injection with a modification of the Spalteholz technique. The animals in the control group showed no neurological abnormalities, no changes in cortical evoked potentials, normal microvascularity, and no histopathological changes in the nerve roots or the spinal cord. The dogs in which the cauda equina had been constricted 25 per cent had no neurological deficits, mild changes in cortical evoked potentials, slight histological changes, and venous congestion of the root and dorsal root ganglion of the seventh lumbar nerve. The dogs in which the cauda equina had been constricted 50 per cent had mild initial motor weakness, major changes in cortical evoked potentials, edema and loss of myelin in the root of the seventh lumbar nerve, and moderate or severe venous congestion of the root and dorsal root ganglion of the seventh lumbar nerve. The dogs in which the cauda equina had been constricted 75 per cent had significant weakness, paralysis of the tail, and urinary incontinence; two dogs recovered by the third month, but all had neurogenic claudication for three months. All six dogs had dramatic changes in cortical evoked potentials and had complete nerve-root atrophy at the level of the constriction. There was blockage of axoplasmic flow and wallerian degeneration of the motor nerve roots distal to the constriction and of the sensory roots proximal to the constriction, as well as degeneration of the posterior column. Severe arterial narrowing at the level of the constriction and venous congestion of the roots and dorsal root ganglia of the seventh lumbar and first sacral nerves were also present. Cortical evoked potentials revealed neurological abnormalities before the appearance of neurological signs and symptoms.(ABSTRACT TRUNCATED AT 400 WORDS)

Urologic changes after cauda equina compression in dogs.

Relative degrees (25%, 50% or 75%) of constriction of the entire cauda equina at the seventh lumbar level were performed on eighteen pure bred female beagle hounds by surgically implanting a circular polyethylene loop with an imbedded stainless steel wire. The wire was mechanically constricted by external control and the degree of compression was confirmed by pre- and postoperative magnetic resonance imaging or computed tomography scanning. A control group of two dogs had laminectomy only. Neurologic function was evaluated daily. Cystometrics were performed on each dog after constriction had been present for three months. Cortical evoked potentials (CEPs) were obtained on all dogs preoperatively, immediately following constriction and at monthly intervals for three months. Dogs were sacrificed at three months and the cauda equina and spinal cord were examined histopathologically. Cystometric tracings were noted to become a flat line with 75% compression of the cord. Less compression had minimal effect on the cystometric curves. The mean latency, determined by cortical evoked potentials, was noted to increase by 3.2%, 7.8%, and 17.2% immediately after 25%, 50% and 75% constriction, respectively. Histologic changes ranged from occasional enlargement of the axons on the periphery of the cauda equina with 25% constriction to severe loss of all axons and atrophic roots at the level of the constricting band with 75% constriction.

Morphologic study of the participation of the complement system in hyperacute rejection of renal xenotransplants.

The role of polymorphonuclear leukocyte (PMN) and platelet infiltration in the hyperacute rejection of renal xenotransplants was studied. In a first group, a dog kidney was grafted to rabbit recipients with intact immune adherence and chemotaxis. A second group included recipients depleted of PMN's with nitrogen mustard, and in a third group, immune adherence and chemotaxis were modified by depleting the third component of complement by means of cobra venom factor. Serial kidney biopsies were studied with light and electron microscopic technics. A semiquantitative evaluation of PMN and platelet glomerular infiltration indicated that a reduction in the number of PMN's or platelets is associated with an increased survival time of the transplanted kidney.