Hydatid cysts of central nervous system are rare and comprise only 2% to 3% of all hydatid cysts reported. Orbital localization is very uncommon and has been reported less than 1% of all hydatid diseases. The primary treatment of hydatid disease is surgical. The most important complication of the surgical treatment is secondary hydatidosis due to spillage of the cyst contents. Because of the difficulties of the orbital localization, total extirpation of the cysts without rupture is almost impossible. Preventing spontaneous rupture of the cysts during surgery and postoperative antihelmintic treatment should be taken into consideration in these cases. This study includes four cases who underwent surgery for orbital hydatid cysts. Radiological characteristics, operative technique and postoperative medical therapy are discussed.

Parathyroid hormone-related protein (PTHrP) is the major mediator of the humoral hypercalcemia of malignancy and of malignant osteolysis associated with skeletal metastases of common epithelial cancers. PTHrP secretion is regulated by the extracellular calcium concentration ([Ca(2+)](o)) in several types of normal and malignant cells. Because the [Ca(2+)](o)-sensing receptor (CaR) is a key mediator of [Ca(2+)](o)-regulated hormone secretion [e.g., of parathyroid hormone (PTH) by parathyroid chief cells], we investigated the expression of the CaR and PTHrP in normal and neoplastic glial cells and studied the effects of [Ca(2+)](o) on PTHrP secretion. Our results show that primary embryonic human astrocytes (HPA) express CaR mRNA and protein as detected by RT-PCR and Western analysis, respectively. Furthermore, astrocytomas and meningiomas also express the CaR at similar levels as assessed by RT-PCR and Northern and Western blot analyses. HPA and astrocytomas express transcripts encoding all three known isoforms of PTHrP [PTHrP(139), PTHrP(141), and PTHrP(173), comprising 139, 141, and 173 predicted amino acid residues, respectively] as assessed by RT-PCR, whereas meningiomas express only the first two of these. Finally, elevated levels of [Ca(2+)](o) and other polycationic CaR agonists dose dependently stimulate PTHrP secretion from HPA, astrocytomas, and meningiomas, although both basal and high [Ca(2+)](o)-stimulated rates of PTHrP secretion are approximately 2. 5-fold higher in HPA than in the glial tumors studied here. Therefore, our results show that HPA, astrocytomas, and meningiomas express both the CaR and PTHrP and that CaR agonists stimulate PTHrP secretion.

Decreasing size of disc material that has herniated, whether "contained" or "protruded" has previously been described and sometimes this can be so complete that residual material is barely visible. In a retrospective clinical survey, from among almost 2180 consecutive patients admitted during 1994 - 2002 with low back pain; due to our low follow-up ratios and high price of the magnetic resonance imaging (MRI), only 42 patients with a lumbar disc protrusion could be found who had two MRI scans obtained at least five weeks apart. Among these, 4 patients were spotted with a totally resolved disc protrusion. T (2)-weighted MRI images were suggesting shrinkage due to dehydration and regression within the annulus of protruded disc fragments that had not fully migrated. Our patients are further examples for total resolution of the large "protruded" disc without any treatment; and since concomitant disc protrusions at other levels persisted, the resolution of these discs is supposed to be spontaneous.