Katsuya Umeoka

Expression of GATA-2 in Human Pituitary Adenomas

Transcription factor GATA-2 contains two copies of a highly conserved zinc finger domain and plays unique roles at an early stage of hematopoietic differentiation. In the mouse pituitary gland, Pit-1-GATA-2 protein–protein interaction has been shown to lead to gene-specific actions to obtain cell-specific roles. In this study, we investigated the expression of GATA-2 and Pit-1 in human pituitary adenomas using reverse transcription polymerase chain reaction (RT-PCR) and immunohistochemical techniques. By immunohistochemical analysis, GATA-2 was detected in all of the gonadotropin-subunit (Gn-su)-positive adenomas (n = 8) and in four of five thyroid-stimulating hormone (TSH)-secreting adenomas, but its incidence was low in the other types of adenomas. Pit-1 protein was detected in 4 of 5 TSH-secreting adenomas and in 10 of 10 growth hormone (GH)-secreting adenomas. By RT-PCR analysis, GATA-2 was detected in all Gn-su-positive adenomas and TSH-secreting adenomas, and Pit-1 was detected in all TSH-secreting adenomas and GH-secreting adenomas. These results suggested that GATA-2 contributes to the functional expression and the differentiation of Gn-su-positive adenomas and the TSH-secreting adenomas and that the interaction between GATA-2 and Pit-1 can lead to gene-specific action and differentiation of TSH-secreting adenomas. It is further speculated that GATA-2 and transcriptional interaction with Pit-1 play roles in the functional differentiation of specific pituitary adenomas.

Immunohistochemical analysis of p27 (Kip1) in human pituitary glands and in various types of pituitary adenomas

Abstractp27 (Kip1) plays regulatory roles in the cell cycle by inhibiting the activity of cyclin dependent kinases (CDKs). This immunohistochemical study is aimed at elucidating the expression of p27 in human pituitary and in various types of pituitary adenomas in order to clarify its role in the regulation of proliferation.Sixteen normal pituitary glands and 179 human pituitary adenomas were used for immunohistochemical studies. The tissues were fixed in 10% formalin and embedded in paraffin. Indirect peroxidase method was performed after heat-induced antigen retrieval using a monoclonal antibody against p27 protein. p27 protein was expressed in the nuclei of all 16 normal human pituitary glands. p27 protein was also expressed in 128 of 179 cases of pituitary adenomas (71.5%).A marked decrease of p27 expression was noted in ACTH-secreting adenomas, 8/20 (40.0%), compared with other types of pituitary adenomas—GH-secreting adenomas, 35/46 (76.1%); PRL-secreting adenomas, 22/33 (66.7%); TSH-secreting adenomas, 8/11 (72.7%); and nonfunctioning adenomas, 55/69 (79.7%).These results suggest that p27 may play some role in the regulation of proliferation in all types of pituitary adenomas. The lower levels of p27 in ACTH-secreting adenoma is of particular interest with respect to the intermediate lobe-derived pituitary tumor developed in p27 knockout mice.

Ischemic complications after radial artery grafting and aneurysmal trapping for ruptured internal carotid artery anterior wall aneurysm.

OBJECTIVE Treatment of ruptured internal carotid artery anterior wall (ICAW) aneurysms presents a surgical challenge because limitations and difficulties are encountered with either clipping or endovascular treatment. The present study examined clinical outcomes after aneurysmal trapping followed by radial artery grafting for management of these difficult lesions. METHODS Radial artery grafting was followed immediately by parent artery occlusion in five sides of five patients with acute ruptured ICAW aneurysm (3 men, 2 women; mean age 55.2 years). All patients underwent postoperative angiography and computerized tomography to assess graft patency and ischemic complications including vasospasm. RESULTS Of the five patients, only one had a poor outcome. However, temporary ischemic complications due to vasospasm developed in four (80%) of the five patients. Long-term results of radial artery grafting and internal carotid trapping for acute stage ruptured ICAW were satisfactory, but detailed analysis indicated a high risk of ischemic complications. CONCLUSIONS The long-term result was satisfactory, but there was a high rate of acute stage ischemic complications due to delayed vasospasm and low perfusion from the radial artery graft. Based on these results, the investigators recommend that, in addition to intraoperative anticoagulation therapy, in cases where the cerebral blood flow study in the early postoperative period indicates low cerebral perfusion or in cases with World Federation of Neurological Societies grade III-V, the patients should be placed under the highest level of intensive care to detect ischemic complications.

Immunohistochemical Analysis of RCAS1 in Human Pituitary Adenomas

It has been reported that RCAS1 (receptor-binding cancer antigen expressed on SiSO cells) acts as a ligand for a receptor present on normal peripheral lymphocytes and induces apoptotic cell death. It is expressed in uterine and ovarian carcinomas, especially in invasive cancers. This immunohistochemical study is aimed to elucidate the expression of RCAS1 in human pituitary adenomas in order to clarify its role in their proliferative regulation and invasiveness. Five normal pituitary glands, 50 human pituitary adenomas, and one malignant glioma were subjected to immunohistochemical studies. In normal pituitary glands, immunostaining of RCAS1 and MIB-1 was not found. In malignant glioma, large numbers of cell nuclei were positive for MIB-1 (MIB-1 index: 28%), and RCAS1 was detected both in the cytoplasm and on the membrane of the tumor cells. Expression of RCAS1 was noted in 48% of pituitary adenomas immunohistochemically (60.0% of growth hormone-secreting adenomas, 60.0% of prolactin-secreting adenomas, 42.9% of adrenocorticotrophin-secreting adenomas, 40.0% of thyroid-stimulating hormone-secreting adenomas, 33.3% of nonfunctioning adenomas, and 44.4% of gonadotropin-subunit-positive adenomas). It showed no correlation with tumor type, size, and invasiveness. The statistically significant relationship between RCAS1 and MIB-1 positivity was identified in our study. These results suggest that expression of RCAS1 as well as MIB-1 positivity predict the growth potential of individual pituitary adenomas.

Radial artery grafts for symptomatic cavernous carotid aneurysms in elderly patients

BACKGROUND Radial artery grafts (RAG) have been used in the treatment of complex vascular lesions, but not for symptomatic cavernous carotid aneurysms in elderly patients. AIM To investigate the safety, usefulness, and perioperative complications of RAGs for symptomatic cavernous carotid aneurysms in elderly patients. MATERIAL AND METHODS Of the 74 consecutive patients, in whom RAGs were used, we retrospectively investigated the postoperative outcomes and complications in eight elderly patients aged over 70 years with symptomatic internal carotid artery aneurysms in cavernous sinus. RESULTS Postoperative complications included one case of cerebral infarction, one case of symptomatic seizures, and one case of delayed cranial nerve palsy. OUTCOME Seven patients had an mRS score of 0, and one patient had a score of 2. Postoperatively there was improvement in cranial nerve palsy in seven patients and the patients who had symptoms for one year and eight months had residual deficits. Although it cannot be stated that the frequency of perioperative complications was low, the final outcomes were favorable. CONCLUSION Even in carotid disease that is difficult to treat among the elderly, RAG would appear to be a useful and safe treatment.

The meningeal branches of the superior cerebellar artery: a surgical observation study

OBJECT The tentorial branch of the posterior cerebral artery was first identified in a cadaver dissection study. However, the tentorial branch of the superior cerebellar artery (SCA) has not been clearly described in autopsy or normal anatomical studies. In this study, a dural branch of the SCA that was found during the surgical treatment of trigeminal neuralgia is described. METHODS Between April 2011 and March 2014, 70 patients with idiopathic trigeminal neuralgia underwent microvascular decompression. The records of 58 patients were reviewed to investigate the meningeal branch of the SCA. RESULTS The meningeal branch of the SCA was visualized in 15 of the 58 patients (25.9%). In 4 patients, it was necessary to divide this branch in order to achieve decompression of the trigeminal nerve without eliciting postoperative neurological deficits. CONCLUSIONS This is the first identification of the meningeal branch of the SCA in living subjects, and such branches were rather frequently found. Recognition of this branch is important for the management of lesions in the cerebellopontine angle and tentorial lesions, using either an open microsurgical or endovascular method.

Perioperative complications of superficial temporal artery to middle cerebral artery bypass for the treatment of complex middle cerebral artery aneurysms

OBJECT Only a few studies have reported the risk of ischemic complications occurring when superficial temporal artery (STA) to middle cerebral artery (MCA) anastomosis is performed during surgery for complex MCA aneurysms. SUBJECTS AND METHODS This is a retrospective study of 10 patients (age 52-73) with MCA aneurysms treated with revascularization surgery. The aneurysms were 10-50mm in size (mean: 21mm). We studied the causes and frequency of ischemic complications by analyzing postoperative magnetic resonance imaging. RESULTS Postoperative diffusion-imaging confirmed ischemic complications in six of the 10 patients (in two of the five ruptured aneurysms and in four of the five unruptured). The ischemic complications that observed were infarction of the lenticulostriate artery territory in three cases, cortical infarction in two cases, and cerebral infarction that was likely to be due to cerebral vasospasm in one case. In one case, both cortical infarction and infarction of the lenticulostriate artery territory were observed. The Glasgow Outcome Scale (GOS) scores at the time of discharge indicated good recovery (GR) and moderate disability (MD) in seven cases, severe disability (SD) in two cases, and death (D) in one case. CONCLUSIONS The present study suggests the possibility that STA-MCA anastamosis in surgeries for MCA aneurysms can be performed with comparatively better safety. However, the temporary occlusion time with this surgery is longer than that with a temporary clipping for aneurysmal surgery; thus, we believe that adequate countermeasures are required to prevent ischemic complications.

Occlusion of the ascending pharyngeal artery during carotid artery surgery: importance and technique.

AIM In surgeries involving clamping, opening and repairing the carotid artery such as carotid endarterectomy (CEA) and proximal anastomosis at radial artery (RA) grafting, back-bleeding, often due to insufficient occlusion of the ascending pharyngeal artery (APA), must be avoided. In 96% of cases the APA originates at the dorsal side of the external carotid artery, while in 2% each it arises at the carotid bifurcation or the internal carotid artery. We developed a method to prevent back-bleeding from the APA irrespective of its origin. MATERIAL AND METHODS For CEA we dissect the internal carotid artery and clamp the APA and the external carotid artery together. For RA grafting we dissect the external carotid artery and if the APA branches directly from this vessel, the APA is clamped directly. RESULTS We used our new surgical technique in 54 cases (22 CEA and 32 RA grafts) and encountered no major back-bleeding. CONCLUSION We consider this method to be simple and useful for improving the safety and success of carotid artery surgeries.

Successful treatment of a ruptured flow-related aneurysm in a patient with hemangioblastoma: Case report and review of literature

Background: No cerebral aneurysms on the feeder associated with hemangioblastomas that ruptured before resection have been reported. We report a patient with a ruptured flow-related aneurysm associated with cerebellar hemangioblastoma and a tumor feeder treated simultaneously by a single procedure of embolization using N-butyl cyanoacrylate before tumor removal. Case Description: A 36-year-old female with a cerebellar tumor was admitted to our institute. Four days later, she suffered a massive subarachnoid hemorrhage mainly in the posterior fossa. Left vertebral angiograms showed an aneurysm on the feeding artery, posterior inferior cerebellar artery. Both the aneurysm and its main feeder were simultaneously treated by a single procedure of embolization using N-butyl cyanoacrylate. Their complete obliteration was confirmed angiographically. Four days after the procedure, we removed the tumor and the embolized aneurysm. The pathological diagnosis was hemangioblastoma and flow-related ruptured aneurysm. Conclusion: Cerebral angiography should be performed to rule out vascular abnormalities such as cerebral aneurysms adjacent to the tumor in patients with hemangioblastoma who present with intracranial hemorrhage. We emphasize the usefulness of embolization with N-butyl cyanoacrylate for hemangioblastoma with ruptured feeder aneurysm, by which the aneurysm and the feeder could be simultaneously embolized.

Target-controlled infusion technique with indocyanine green videoangiography for radial artery graft

OBJECT To understand the relationship between the parent artery and its distal arteries, blood vessels running through the subarachnoid space need to be extensively dissected, which is time-consuming. We examined the efficacy of temporary clipping with the indocyanine green (ICG) technique (target-controlled infusion (TCI) technique), in which the parent artery is occluded using a temporary clip, and ICGV (videoangiography) is performed to clarify the relationship between the distal M4 and proximal M2. METHODS Thirteen radial artery grafts (RAGs) for internal carotid aneurysm underwent TCI to confirm the relationship between M2 and cortical M4. To monitor the perfusion pressure of the cortical middle cerebral artery, superficial temporal artery (STA) to M4 anastomosis was performed before RA-M2 anastomosis. We performed anastomosis of the recipient of STA- M4 that was distal and downstream of the M2 segment that is the recipient of RA-M2 anastomosis. To select the proper recipient M4 of the STA-M4 anastomosis, the ICGV image range was set sufficiently wide to accommodate the possibility that the distal artery was not the one anticipated. ICGV followed complete occlusion by temporary clipping of the recipient M2. RESULTS In 2 of the 13 cases, the relationship between the M2 and M4 could not be clarified. CONCLUSIONS In cases with developed collateral circulation or small perfusion area of the occluded M2, it was difficult to ascertain the relationship by TCI. Nevertheless, TCI was useful in 11 of the 13 cases, suggesting that unnecessary dissection in the subarachnoid space may be reduced using this technique.