A 3 tesla magnetic resonance imaging volumetric analysis of the hippocampal formation: dependence on handedness and age.

BACKGROUND: The hippocampal formation (HF) is one of the most important parts of the brain in the magnetic resonance imaging (MRI) volumetric analysis in various domains, but not completely from all aspects, including the handedness. The aim of our study was to evaluate the possible differences in the volume of the right and left HF among the healthy right-handed and left-handed subjects, and to determine whether the volume differences are age related. MATERIALS AND METHODS: The MRI of this prospective study was performed using T1 fast field echo (FFE) sequence. The 124 subsequent coronal slices (thickness 1.5 mm) were performed in each participant. The obtained HF volumes were normalised and statistically compared. Volunteers comprised 30 persons aged 22.0 years, 12 of whom were the left-handed, and 30 persons aged 75.2 years on average, 9 of whom were the left-handed. RESULTS: The right and left HF volumes averaged 2.986 cm3 and 2.858 cm3 in the right-handed, and 2.879 cm³ and 3.020 cm³ in the left-handed young volunteers, as well as 2.728 cm³ and 2.650 cm³ in the right-handed, and 2.617 cm³ and 2.780 cm³ in the left-handed elderly persons. The HF volume ratios in the young left-handed participants showed a significant left-greater-than-right asymmetry. A significant difference was also noticed within the right-to-left volume ratios of the right- and left-handed young and elderly participants. The latter reduction in the HF volume within the aged group can be interpreted as a slight atrophy of the HF. CONCLUSIONS: There is a significant difference in the volumes of the left and right HF of the left-handed young participants. The age related HF volume differences were proven between the groups of the young and elderly volunteers. The obtained data should be included into the future MRI studies of the HF volumes in various clinical domains.

Craniovertebral anomalies associated with pituitary gland duplication.

BACKGROUND: An extremely rare occurrence of the pituitary gland duplication inspired us to examine in detail the accompanying craniovertebral congenital anomalies in a patient involved. MATERIALS AND METHODS: T1-wighted magnetic resonance imaging (MRI) was performed, as well as the multislice computerised tomography (MSCT) and MSCT angiography in our patient, as well as in a control group of 10 healthy subjects. RESULTS: In a 20-year-old male a double pituitary gland was identified, as well as hypothalamic enlargement, tuberomamillary fusion and hamartoma. In addition, the patient also showed a duplicated hypophyseal fossa and posterior clinoid processes, notch of the upper sphenoid, prominent inner relief of the skull, inverse shape of the foramen magnum, third occipital condyle, partial aplasia of the anterior and posterior arches of the atlas with a left arcuate foramen, duplication of the odontoid process and the C2 body, and fusion of the C2-C4 and T12-L1 vertebrae. The MSCT angiography presented a segmental dilatation of both vertebral arteries and the A2 segment of the anterior cerebral artery, as well as a duplication of the basilar artery. CONCLUSIONS: This patient is unique due to complex craniovertebral congenital anomalies associated with a duplication of the pituitary gland.

[Topographic localisation of insertion of the anterior cruciate ligament].

INTRODUCTION: Determining the center of tibial insertion of the anterior cruciate ligament is important during reconstruction ligament. AIM: Determining the center of insertion of the anterior cruciate ligament on the anterior intercondylar area relate to anterior and medial edge of the upper end of tibia. MATERIAL AND METHODS: The messurement has been done on 102 tibia. We measured distance from the center of ACL to anterior and medial edge of the uper part of tibia, and the lenght and the width of the tibial insetion. Also, we showed the procentual ratio these distances with medio-lateral and anteroposterior diametar of upper tibial part. RESULTS: The distance between the centre of attachment and medial edge is at 39% from entire latero-medial diametar, while the distance from anterior edge is at 31% from entire anterio-posterior diametar. The possitive correlation between the distance of centar of the anterior cruciate ligament from anterior and inner edge (r = 0.366, p) was found. CONCLUSION: The center of the attachment of the ACL at anterior intercondylarl area is at 1/3 of antero-posterial diametar behind the anterior edge of the upper part of tibia and 2/5 of latero-medial diametar inside from the medial edge.

Ryanodine receptors, voltage-gated calcium channels and their relationship with protein kinase A in the myocardium.

We present a review about the relationship between ryanodine receptors and voltage-gated calcium channels in myocardium, and also how both of them are related to protein kinase A. Ryanodine receptors, which have three subtypes (RyR1-3), are located on the membrane of sarcoplasmic reticulum. Different subtypes of voltage-gated calcium channels interact with ryanodine receptors in skeletal and cardiac muscle tissue. The mechanism of excitation-contraction coupling is therefore different in the skeletal and cardiac muscle. However, in both tissues ryanodine receptors and voltage-gated calcium channels seem to be physically connected. FK-506 binding proteins (FKBPs) are bound to ryanodine receptors, thus allowing their concerted activity, called coupled gating. The activity of both ryanodine receptors and voltage-gated calcium channels is positively regulated by protein kinase A. These effects are, therefore, components of the mechanism of sympathetic stimulation of myocytes. The specificity of this enzyme's targeting is achieved by using different A kinase adapting proteins. Different diseases are related to inborn or acquired changes in ryanodine receptor activity in cardiac myocytes. Mutations in the cardiac ryanodine receptor gene can cause catecholamine-provoked ventricular tachycardia. Changes in phosphorylation state of ryanodine receptors can provide a credible explanation for the development of heart failure. The restoration of their normal level of phosphorylation could explain the positive effect of beta-blockers in the treatment of this disease. In conclusion, molecular interactions of ryanodine receptors and voltage-gated calcium channels with PKA have a significant physiological role. However, their defects and alterations can result in serious disturbances.