Prenatal development of the human entorhinal cortex.

Little is known about the development of the human entorhinal cortex (EC), a major hub in a widespread network for learning and memory, spatial navigation, high-order processing of object information, multimodal integration, attention and awareness, emotion, motivation, and perception of time. We analyzed a series of 20 fetal and two adult human brains using Nissl stain, acetylcholinesterase (AChE) histochemistry, and immunocytochemistry for myelin basic protein (MBP), neuronal nuclei antigen (NeuN), a pan-axonal neurofilament marker, and synaptophysin, as well as postmortem 3T MRI. In comparison with other parts of the cerebral cortex, the cytoarchitectural differentiation of the EC begins remarkably early, in the 10th week of gestation (w.g.). The differentiation occurs in a superficial magnocellular layer in the deep part of the marginal zone, accompanied by cortical plate (CP) condensation and multilayering of the deep part of CP. These processes last until the 13-14th w.g. At 14 w.g., the superficial lamina dissecans (LD) is visible, which divides the CP into the lamina principalis externa (LPE) and interna (LPI). Simultaneously, the rostral LPE separates into vertical cell-dense islands, whereas in the LPI, the deep LD emerges as a clear acellular layer. In the 16th w.g., the LPE remodels into vertical cell-dense and cell-sparse zones with a caudorostral gradient. At 20 w.g., NeuN immunoreactivity is most pronounced in the islands of layer II cells, whereas migration and differentiation inside-out gradients are seen simultaneously in both the upper (LPE) and the lower (LPI) pyramidal layers. At this stage, the EC adopts for the first time an adult-like cytoarchitectural organization, the superficial LD becomes discernible by 3T MRI, MBP-expressing oligodendrocytes first appear in the fimbria and the perforant path (PP) penetrates the subiculum to reach its molecular layer and travels along through the Cornu Ammonis fields to reach the suprapyramidal blade of the dentate gyrus, whereas the entorhinal-dentate branch perforates the hippocampal sulcus about 2-3 weeks later. The first AChE reactivity appears as longitudinal stripes at 23 w.g. in layers I and II of the rostrolateral EC and then also as AChE-positive in-growing fibers in islands of superficial layer III and layer II neurons. At 40 w.g., myelination of the PP starts as patchy MBP-immunoreactive oligodendrocytes and their processes. Our results refute the possibility of an inside-out pattern of the EC development and support the key role of layer II prospective stellate cells in the EC lamination. As the early cytoarchitectural differentiation of the EC is paralleled by the neurochemical development, these developmental milestones in EC structure and connectivity have implications for understanding its normal function, including its puzzling modular organization and potential contribution to consciousness content (awareness), as well as for its insufficiently explored deficits in developmental, psychiatric, and degenerative brain disorders.

Sex or surgery--erectile dysfunction after radical treatment of localized prostate cancer.

The maintenance of satisfactory quality of life is major concern in majority of patients who elect treatment for localized prostate cancer. We conducted a cross-sectional study to determine sexual function after radical prostatectomy (RP) and external beam radiotherapy (EBRT). Study population consisted of series of 57 patients with early-stage adenocarcinoma of the prostate, treated in our institution in the period from January 2003 till December 2003. Thirty three patients underwent radical retropubical prostatectomy and 24 patients were treated by primary radical radiotherapy. Patients have been given the full international index of erectile function (IIEF) questionnaire two to four and six months after the treatment. Post treatment sexual function in patients treated by EBRT is significantly better than in patients treated by RP (48.5% vs. 21.57%, p < 0.0001). Subgroup analysis reveals that satisfaction with erectile function, maintaining of sexual intercourse and possibility of ejaculation is better in patients treated by EBRT than in patients treated by RP (44.67% vs. 11.57%, p < 0.0001) as well as general satisfaction with quality of sexual life (48.5% in EBRT group vs. 21.57% in RP group, p < 0.0001). On the other hand, sexual desire remains the same in both groups of patients (63.75% in EBRT group vs. 60.61% in RP group, p = 0.71). Six months after surgical or radiotherapy treatment erectile function is almost as twice as worse in patients treated by surgery than in patients treated by radiotherapy.

The neglected maxillary process of the palatine bone.

In most recent anatomy textbooks as well as in the latest anatomical nomenclature, the maxillary process of the palatine bone is not mentioned at all. The maxillary process is, however with rare exceptions, always present as an important part of the closure of the hiatus sinus maxillaris. In our material consisting of 200 disarticulated, macerated skull bones and 25 specimens of maxillary sinus, the maxillary process was missing in only 5 cases (2.2%). This process develops in the second year of life and displays different shapes. It can be long and slender or wide and round shaped. Its upper margin is more or less concave, corresponding to the margin of the hiatus over which it is bent. Its inferior margin can be smooth or irregular. In instances in which maxillary sinus is double, the os palatinum has two maxillary processes, so that both sinuses are partly closed with the maxillary process of the palatine bone.

The fate of the arachnoid villi in humans.

Villi arachnoidales undergoes in the course of life changes in relation to the skull bones and sinuses. Our aim was to determine the relations of the villi arachnoidales to the skull bone and/or sinuses from the neonatal period to adults. The investigations were performed on collection of 50 disarticulated macerated skull bones from the new-born to 30 years of age and on 20 skulls from individuals in the life period from 30 to 80 years of age. Villi arachnoidales produced imprints on the skull bones in the shape of holes and/or furrows corresponding to different shape of the villi arachnoidales. These imprints appeared very early in the period when the bony sprouts of the large skull bones received a thin covering of compact bone, the future lamina vitrea. At that time villi arachnoidales had no connection with the dural sinuses but with the diploe and with the diploic veins. By agglomeration of the villi in larger and large formations, granula meningea, Pacchionian granulations, the contact to sinuses was realized by means of short channels. The structural changes of villi arachnoidales may produce thrombophlebitis and hydrocephalus externus, especially in children. The fate and the relations of the villi arachnoidales are therefore of great importance for neurologist, neurosurgeon and otorhinolaryngologist.