The clinical characteristics of three subgroups of non-functioning pituitary adenomas

Introduction: Despite the fact that non-functioning pituitary adenomas do not overproduce hormones, many will stain positive for a particular pituitary hormone, which can be used to differentiate these adenomas into subgroups. If these different sub-groups behave differently in terms of post surgical progression of disease (PSPD) rates or other clinical variables, then better treatment and prognosis could be predicted. Methods: This was a retrospective cohort study. Patients who have undergone surgery for removal of a non-functioning pituitary adenoma at Emory University Hospital served as the source for all data used in this study (n = 184). Data were collected from a database of electronic medical records (EMRs) for these patients in 2010 documenting clinical and demographic variables including treatment and PSPD. Results: Risk for PSPD did not differ by adenoma subtypes: follicle-stimulating hormone (FSH+), luteinizing hormone (LH+), or those that do not stain positive for any hormone (non-functioning, or NF?) (p = 0.971). There were two clinical characteristics statistically related to adenoma subtype: altered mental status and the anterior-posterior (AP) dimension of pre-operative adenomas. PSPD was related to several clinical characteristics, including gender, previous adenoma, post-operative residual, and follow-up time.

miR-200b-3p accelerates progression of pituitary adenomas by negatively regulating expression of RECK

MicroRNA(miR)-200b-3p has been associated with many tumors,but its involvement in pituitary adenoma is unclear.This study investigated the molecular mechanism underlying miR-200b-3p regulation in pituitary adenomas to provide a theoretical basis for treatment.Bioinformatics was used to analyze pituitary adenoma-related genes and screen new targets related to RECK and miRNA.As well,the relationship between miR-200b-3p and RECK protein was verified using a double-luciferase reporter gene assay.The expression of miR-200b-3p in clinical samples was analyzed by in situ hybridization.Transfection of the miR-200b-3p inhibitor and small interfering-RECK(si-RECK)was verified by qPCR.GH3 cell viability and proliferation were detected using CCK8 and EdU assays.Apoptosis was detected by flow cytometry and western blotting.Wound healing and Transwell assays were used to detect cell migration and invasion.The effects of miR-200b-3p and RECK on GH3 cells were verified using salvage experiments.miR-200b-3p was highly expressed in pituitary tumor tissue.Inhibitors of miR-200b-3p inhibited cell proliferation promoted cell apoptosis,inhibited invasion and migration,and inhibited the expression of matrix metalloproteinases.Interestingly,miR-200b-3p negatively regulated RECK.The expression of RECK in pituitary adenoma tissues was lower than that in neighboring tissues.Si-RECK rescued the function of miR-200b-3p inhibitors in the above cellular behaviors,and miR-200b-3p accelerated the development of pituitary adenoma by negatively regulating RECK expression.In summary,this study investigated the molecular mechanism by which miR-200b-3p regulates the progression of pituitary adenoma through the negative regulation of RECK.The findings provide a new target for the treatment of pituitary adenoma.

Identification of CDK6 and RHOU in Serum Exosome as Biomarkers for the Invasiveness of Non-functioning Pituitary Adenoma

Objective To explore circulating biomarkers for screening the invasiveness of non-functioning pituitary adenomas(NF-PAs).Methods The exosomal RNAs were extracted from serum of patients with invasive NF-PA(INF-PA)or noninvasive NF-PA(NNF-PA).Droplet digital PCR was adapted to detect the mRNA expression of candidate genes related to tumor progression or invasion,such as cyclin dependent kinase 6(CDK6),ras homolog family member U(RHOU),and spire type actin nucleation factor 2(SPIRE2).Student’s t-test was used to analyze the statistical difference in the mRNA expression of candidate genes between the two groups.Receiver operating characteristic(ROC)curve was used to establish a model for predicting the invasiveness of NF-PAs.The accuracy,sensitivity,specificity and precision of the model were then obtained to evaluate the diagnostic performance.Results CDK6(0.2600±0.0912 vs.0.1789±0.0628,t=3.431,P=0.0013)and RHOU mRNA expressions(0.2696±0.1118 vs.0.1788±0.0857,t=2.946,P=0.0052)were upregulated in INF-PAs patients’serum exosomes as compared to NNF-PAs.For CDK6,the area under the ROC curve(AUC)was 0.772(95%CI:0.600-0.943,P=0.005),the accuracy,sensitivity,specificity and precision were 77.27%,83.33%,75.00%and 55.56%to predict the invasiveness of NF-PAs.For RHOU,the AUC was 0.757(95%CI:0.599-0.915,P=0.007),the accuracy,sensitivity,specificity and precision were 72.73%,83.33%,68.75%and 50.00%.In addition,the mRNA levels of CDK6 and RHOU in serum exosomes were significantly positively correlated(r=0.935,P<0.001).After combination of the cut-off scores of the two genes,the accuracy,sensitivity,specificity and precision were 81.82%,83.33%,81.25%and 62.50%.Conclusions CDK6 and RHOU mRNA in serum exosomes can be used as markers for predicting invasiveness of NF-PAs.Combination of the two genes performs better in distinguishing INF-PAs from NNF-PAs.These results indicate CDK6 and RHOU play important roles in the invasiveness of NF-PAs,and the established diagnostic method is valuable for directing the clinical screening and postoperative treatment.

Radiotherapy in Non-Functioning Pituitary Macroadenoma： Mansoura Experience

OBJECTIVE The current retrospective study aims to evaluate the management of non-functioning the assessment of experience on pituitary macroadenoma through clinical, biochemical, radiological features, and treatment outcome of patients, and to identify prognostic factors affecting progression-free survival （PFS）. METHODS Data of 55 patients macroadenoma presented to the with non-functioning pituitary Clinical Oncology and Nuclear Medicine department between 1998 and 2009 were investigated. RESULTS The most common symptom was visual disturbance （38.2%） followed by headache （27.3%）. The presence of male predominance was observed （1.4：1）. Ten patients received radio-therapy （RT） only. Extrasellar extension was the more common treatment. The overall response rate was 72.8% with completed response at 16.4%. Memory and intellectual sequelae were the most common late complications of treatment （14%）. The ten-year PFS was at 84.6%. PFS was found to be significantly better with higher dose of RT （up to 54 Gy）, treatment by both surgery and RT, absence of visual field defect, and tumor localized to sella, whereas it was not significantly affected by age and sex. CONCLUSION The data confirmed that the prevalence of mass effect and hypopituitarism in patients with non-functioning pituitary macroadenoma is elevated. Conventional external RT up to 54 Gy is safe and effective in controlling non-functioning pituitary macro- adenoma with tolerable and acceptable morbidity.

A Rare Case of Non-Functioning Pituitary Macroadenoma (NFMA)

NFMAs are benign tumors that do not produce any biologically active hormones and exceed 10 mm (0.39 in) in size. Although NFMAs are benign in origin, mass effects may lead to serious clinical symptoms such as visual impairments, chronic headache, and pituitary insufficiency. The authors describe a 51-year-old woman who had a NFMA (35 × 24 × 25 mm). The vision was reduced to 7/10 in the both eyes. A transnasal transsphenoidal surgery was performed and the tumor was successfully resected. Postoperatively, the patient had visual (9/10) and headache improvement. This case highlights a rare presentation of non-functioning pituitary macroadenoma.

Magnetic Resonance Imaging and Biological Markers in Pituitary Adenomas with Invasion of the Cavernous Sinus Space

Objective: To investigate the predictability of MRI and the possiblebiological markers of cavernous sinus invasion of pituitary adenomas associated with fourphenomenas: angiogenesis, cell proliferation, apoptosis and matrix metalloproteinase. Methods: Weevaluated 45 patients with pituitary adenoma according to the MRI, surgical findings and theimmunohistochemistry staining of tumor tissues. Results: The results have shown that the sensitivityof MRI for predicting cavernous sinus invasion in this prospective study was 60%, its specificity85%, its positive predictive value 83.33%, negative predictive value 62.96%. 45 specimens ofpituitary adenomas were analyzed for expression of F8, VEGF, Ki-67, c-myc, Bcl-2, nm23 and MMP-9immunoreactivity using immunoperoxidase staining. MVD was assessed using F8-related antigen. Theresults have shown that MVD of invasive pituitary adenomas was significantly higher than that ofnoninvasive (P 【 0.001). There was an association between the invasion of pituitary adenomas andKi-67 LI (P = 0.039) or the expression of VEGF (P 【 0.001) and MMP-9 (P 【 0.001). But c-myc LI andBcl-2 expression have no association with invasiveness of pituitary adenomas (P = 0.061 versus P =0.201). On the other hand, there is an inverse relationship between nm23 expression and tumorinvasion (P 【 0.001). Conclusion: Parasellar extension of pituitary adenomas through the medial wallof the cavernous sinus is diagnosed at surgery, and with sensitive gadolinium-enhanced MRI, itsextent can be partly determined by radiology. Although our study has shown that MVD and theexpression of VEGF, Ki-67, nm23 and MMP-9 have associations with invasiveness of pituitary adenomas,they are lack of specificity. These markers can only provide some useful information.

Neuroendoscopic and microscopic transsphenoidal approach for resection of nonfunctional pituitary adenomas

BACKGROUND Nonfunctional pituitary adenoma is a common type of pituitary adenoma, which can lead to headache, visual field disturbance, and cranial nerve damage due to increased tumor volume. Neuroendoscopic and microscopic transsphenoidal approaches have been widely used in the resection of nonfunctional pituitary adenomas. However, the clinical efficacy in neuroendoscopic and microscopic surgery is still controversial. AIM To explore the clinical efficacy of neuroendoscopic and microscopic transsphenoidal approach for resection of nonfunctional pituitary adenomas. METHODS We retrospectively analyzed 251 patients with nonfunctional pituitary adenomas;138 underwent neuroendoscopic surgery via transsphenoidal approach, and 113 underwent microscopic surgery via transsphenoidal approach between July 2010 and September 2015. All patients were followed up for > 6 mo. Gender, age, course of disease, tumor diameter, tumor location, and percentage of patients with headache, visual impairment, sexual dysfunction, and menstrual disorders were contrasted between the two groups to compare the difference of preoperative data. Cure rate, symptom improvement rate, recurrence rate, the postoperative hospital stay, operating time, intraoperative blood loss, and the incidence of postoperative complications were compared in order to evaluate the advantages and disadvantages of neuroendoscopic and microscopic surgery.RESULTS There was no significant difference in cure rate, symptom improvement rate, and recurrence rate between neuroendoscopy group and microscopy group (82.6% vs 85.8%, P > 0.05;90.6% vs 93.8%, P > 0.05;5.1% vs 9.7%, P > 0.05). In the neuroendoscopy group, the postoperative hospital stay was 8.4 ± 0.6 d;operating time was 167.2 ± 9.6 min;intraoperative blood loss was 83.4 ± 9.3 mL, and the rates of diabetes insipidus and electrolyte imbalance were 4.3% and 8.0%, respectively. The corresponding results in the microscopic group were 11.2 ± 0.6 d, 199.7 ± 9.3 min, 138.8 ± 13.6 mL, and 32.7% and 20.4%, respectively. There were significant differences in postoperative hospital stay, operating time, intraoperative blood loss, and the rates of diabetes insipidus and electrolyte imbalance between the two groups (P < 0.05). CONCLUSION Neuroendoscopic and microscopic transsphenoidal approaches have similar clinical efficacy for the resection of nonfunctional pituitary adenomas. Neuroendoscopic surgery reduces operating time, intraoperative bleeding, postoperative recovery, and complications.

Study on the Expression Levels of CXCR4, CXCL12, CD44, and CD147 and Their Potential Correlation with Invasive Behaviors of Pituitary Adenomas

Objective To evaluate the factors of CXCR4, CXCL12, CD44, and CD147 as early potential diagnostic biomarkers by determining their expression levels in invasive and non-invasive pituitary adenomas. Methods Fresh pituitary adenoma specimens were collected from 35 pituitary adenoma （21 invasive and 14 non-invasive） patients who underwent surgical treatment in our Neurosurgery Department between January and April of 2009. The expression levels of CXCR4, CXCL12, CD44, and CD147 were evaluated firstly by flow cytometry, fluorescence microscopy in single cell suspensions, and then by immunohistochemical staining of paraffin tissue sections. Results Flow cytometric analyses showed that the percentage of CXCR4- and CXCL12-positive cells from invasive pituitary adenomas （IPA） was significantly higher in the single cell suspensions than that from non-invasive pituitary adenomas （nlPA） （P〈O.05）. Immunohistochemical staining revealed that CXCR4 and CXCL12 staining index scores of the invasive pituitary adenomas were significantly higher than those of the non-invasive pituitary adenomas （P〈O.05）. In contrast, neither flow cytometry nor immunohistochemical staining demonstrated significant difference between CD44 and CD147 expression levels, respectively. Conclusion Expression levels of CXCR4 and CXCL12 are correlated with the invasiveness of pituitary adenomas. Therefore, rather than CD44 and CD147, CXCR4 and CXCL12 may potentially serve as biomarkers for early detection of pituitary adenomas.

Hormone Secretion by Cell Culture of Human GH-PRL Secreting Pituitary Adenomas: Effects of Bromocriptine

Dopamine agonists effectively reduce the secretion of prolactin (PRL) in the great majority of prolactinomas and reduce the bulk of the adenomas, as well as have partial therapeutic effect on some patients with acromegaly. The inhibitory effect of bromocriptine (BC), a dopamine agonist, on growth hormone (GH) and PRL secretion of dispersed cells from the pituitary adenomas of 16 cases of acromegaly, which secret GH and PRL simultaneously, were evaluated in vitro. The significant inhibitory effects of BC on PRL secretion were found in 12 cases. It was also found that PRL secretion was strongly inhibited when GH was suppressed; on the contrary, when GH secretion was not suppressed, the production of PRL was not or weakly inhibited. The exact mechanism of the effects is nuclear so far. It is necessary to investigate, at molecular level, the etiology of GH-PRL adenomas and its response to therapeutic agents.

MAGNETIC RESONANCE IMAGING CHARACTERISTICS AND SURGICAL RESULTS OF ADRENOCORTICOTROPIN-SECRETING PITUITARY ADENOMAS

Objective To evaluate magnetic resonance imaging （MRI） characteristics and surgical results of adrenocorticotropin （ACTH） -secreting pituitary adenomas. Methods MRI characteristics and relationship between MRI positive rate and surgical results of 266 patients with pathologically confn＇med Cushing＇s disease were analyzed retrospectively. All patients underwent thin-section sagittal and coronal scans of the pituitary gland before and after administration of gadolinium-diethylene triamine pentaacetic acid （Gd-DTPA） on a 1. 5 Tesla MR/scanner, and dynamic enhanced MR/was performed in 39 patients. All patients underwent transsphenoidal adenomectomy. Endocrinological examinations and assessments were performed. Results Preoperative MR/revealed normal results in 41 （ 15.4% ） cases, microadenoma in 179 （67. 3% ）, macroadenoma in 42 （ 15.8% ）, and huge adenoma in 4 （ 1.5% ）. Pituitary apoplexy was found in 13 （4.9%） cases. Positive rate of ACTH-secreting adenomas was 84.6% （225/266） on MR/scans, and that of small microadenomas was 87.2% （34/39） on dynamic enhanced MRI scans. Preoperative endocrinological tests of 199 cases supported the diagnosis of typical Cushing＇s disease, while the other 67 cases had atypical endocrinological results. The endocrinological cure rate, remission rate, and inefficacy rate were 85.7%, 7.9%, and 6. 4%, respectively. There was no difference in the initial endocrinological cure rate between the patients with positive and normal MRI results （90% vs. 87. 8%, P =0. 904）. Conclusions Enhanced coronal pituitary MR/ is helpful for preoperative localization of ACTH-secreting pituitary microadenoma. Dynamic enhanced MR/may improve detection rate of microadenoma. There is no marked difference in the surgical results for patients with preoperative MR/results indicating presence or absence of microadenoma.

Overview of the 2022 WHO Classification of Pituitary Adenomas/Pituitary Neuroendocrine Tumors:Clinical Practices,Controversies,and Perspectives

The latest edition of the WHO classification of the central nervous system was published in 2021.This review summarizes the major revisions to the classification of anterior pituitary tumors.The most important revision involves preferring the terminology of pituitary neuroendocrine tumor(PitNET),even though the terminology of pituitary adenoma(PA)still can be used according to this WHO classification compared to the previous one.Moreover,immunohistochemistry(IHC)examination of pituitary-specific transcription factors(TFs),including PIT1,TPIT,SF-1,GATA2/3,and ERα,is endorsed to determine the tumor cell lineage and to facilitate the classification of PitNET/PA subgroups.However,TF-negative IHC staining indicates PitNET/PA with no distinct cell lineages,which includes unclassified plurihormonal(PH)tumors and null cell(NC)tumors in this edition.The new WHO classification of PitNET/PA has incorporated tremendous advances in the understanding of the cytogenesis and pathogenesis of pituitary tumors.However,due to the shortcomings of the technology used in the diagnosis of PitNET/PA and the limited understanding of the tumorigenesis of PitNET/PA,the application of this new classification system in practice should be further evaluated and validated.Besides providing information for deciding the follow-up plans and adjunctive treatment after surgery,this classification system offers no additional help for neurosurgeons in clinical practice,especially in determining the treatment strategies.Therefore,it is necessary for neurosurgeons to establish a comprehensive pituitary classification system for PitNET/PA that incorporates neuroimaging grading data or direct observation of invasiveness during operation or the predictor of prognosis,as well as pathological diagnosis,thereby distinguishing the invasiveness of the tumor and facilitating neurosurgeons to decide on the treatment strategies and follow-up plans as well as adjunctive treatment after surgery.

Factors influencing improvement of visual field after trans-sphenoidal resection of pituitary macroadenomas:a retrospective cohort study

AIM: To investigate the influencing factors of visual field improvement after trans-sphenoidal resection of pituitary macroadenomas. METHODS: This retrospective cohort study included 201 patients (366 eyes) with visual field defect induced by pituitary macroadenomas. All of them were treated with trans-sphenoidal surgery. Ophthalmologic evaluation, best -corrected visual acuity (BCVA), and visual field examination were performed before and 3mo after surgery. BCVA, visual field defect index mean deviation (MD), duration of symptoms, age, sex, and volume of tumors were compared. Expression of vascular endothelial growth factor (VEGF) and Ki-67 of tumor tissue were detected by immunohistochemical technique. RESULTS: The mean age of patients was 44.23 +/- 1.29y. Ninety -three patients were female and 108 were male. The mean tumor volume was 14.36 +/- 6.23 cm(3). The mean duration of preoperative symptoms was 11.50 +/- 0.88mo. Mean preoperative MD was -17.50 +/- 0.82 dB. Mean Preoperative visual acuity was 0.64 +/- 0.04. Postoperative visual field improved in 270 (73.77%) eyes, unchanged in 96 (26.23%) eyes. Multivariate logistic regression displayed that the factors independently influencing visual field improvement were young age (OR=1.71, 95%CI: 1.325-2.387, P=0.013), low preoperative MD absolute value (OR=1.277, 95%CI: 1.205-1.355, P<0.001), small volume of tumor (OR=1.458, 95%CI: 1.060-4.289, P<0.001), low expression of VEGF in tumor tissue (OR=1.554, 95%CI: 1.089-2.457, P=0.022), and low expression of Ki-67 in tumor tissue (OR=1.552, 95%CI: 1.161-2.847, P=0.026). CONCLUSION: After pituitary macroadenomas trans sphenoidal resection, the independent influencing factors of the visual fields recovery were low preoperative MD absolute value, young age, small volume of tumor, and expression levels of VEGF/Ki-67.

The Expression of Integrinβ1 and FAK in Pituitary Adenomas and Their Correlation with Invasiveness

The expression and possible role of integrin-focal adhesion kinase signal pathway in invasive pituitary adenomas were explored. Forty-nine human pituitary adenomas were detected for the expression of integrinβ1 （INTβ1） and focal adhesion kinase （FAK） by immunohistochemistry, and their correlation with the invasiveness of pituitary adenomas as well as between themselves was ana- lyzed. The results showed that INTβ1 was expressed in 46 cases （93.9%） and FAK in 36 cases （73.5%）, respectively, and their expression levels were highly correlated with tumor invasiveness, but not with the tumor types. It was suggested that the integrin-focal adhesion kinase signal pathway plays a role in the invasiveness of pituitary adenomas.

Expression for peroxisome proliferator-activated receptor gamma in pituitary adenomas 38 cases for semi-quantitative immunohistochemical analysis

BACKGROUND： It has been reported that peroxisome proliferator-activated receptor γ （PPAR γ ） is highly expressed in lung cancer, colon cancer, and gastric cancer, as well as other tumors.OBJECTIVE： To study expression of PPAR γ in pituitary adenomas and analyze the role of PPAR γ in hormonal typing of pituitary adenomas. DESIGN, TIME AND SETTING： Semi-quantitative immunohistochemistry of pathological specimens. The experiment was conducted at the Department of Neurosurgery, Wuxi Second Hospital Affiliated to Nanjing Medical University between January 2002 and May 2005. MATERIALS： Surgical resection samples of pituitary adenomas from 38 cases （18 male and 20 female） were analyzed. Eight cases were determined to be invasive pituitary adenomas and 30 cases were non-invasive pituitary adenomas. Hormonal classification of the types of pituitary adenomas revealed somatotrophic adenomas in six cases, corticotrophic adenoma in five cases, prolactinomas in 13 cases, multi-hormone secreting adenomas in six cases, and eight cases of adenoma without altered endocrine function. Five autopsy specimens were collected during the same period from patients of matching age that died from unrelated diseases and were included as normal anterior pituitar3, controls. METHODS： Cell counts for positive immunohistochemical signals were recorded from histopathological sections. The percentage of positive cells was reported as a semi-quantitative analysis. MAIN OUTCOME MEASURES： The rate of PPAR γ positive cells in different types of adenoma was based on hormonal levels and invasiveness of pituitary tumor cells. RESULTS： All tumor biopsies were determined to express PPAR γ. The rate of PPAR γ -positive cells ranged between 8%-65% in the pituitary adenomas. According to hormonal type, PPAR γ expression did not vary between the groups. In addition, there was no significant difference in PPAR γ expression between the non-invasive and invasive pituitary adenomas. CONCLUSIONS： Human pituitary adenomas express PPAR γ, and this expression is unrelated to hormonal type and invasiveness.

Expression of second mitochondria-derived activator of caspases, X-linked inhibitor of apoptosis protein, and caspase-3 in pituitary adenomas

Studies concerning correlations between pituitary adenomas and cell apoptosis have mainly focused on upstream apoptosis signaling, but seldom on downstream mediators. In the present study, second mitochondria-derived activator of caspases （Smac）, X-linked inhibitor of apoptosis protein （XIAP）, and caspase-3 protein were qualitatively analyzed using immunohistochemistry, and quantified by western blot. Smac, XIAP, and caspase-3 mRNA expressions were detected by reverse transcription-PCR. Results showed that XIAP protein and mRNA expressions were greater in the invasive pituitary adenoma group compared with the noninvasive pituitary adenoma group. However, Smac and caspase-3 protein and mRNA expressions were lower in the invasive pituitary adenoma group compared with the noninvasive pituitary adenoma group. In the invasive pituitary adenomas, Smac expression was positively correlated with caspase-3 protein and mRNA expression （Protein： r = 0.55, P 0.01; mRNA： r = 0.50, P 0.01）. Smac and caspase-3 expressions were negatively correlated with XIAP protein and mRNA expression （Protein： r = -0.56, -0.64, P 0.01; mRNA： r = -0.69, -0.67, P 0.01）. However, no significant differences in correlation among Smac, XIAP, and caspase-3 were detectable in noninvasive pituitary adenomas. These data indicated that high expression of XIAP and low expression of Smac and caspase-3 suppressed cell apoptosis and led to enhanced invasiveness of pituitary adenomas. Thus, Smac, XIAP, and caspase-3 may be useful markers in determining the invasive behavior of pituitary adenomas.

Ultrastructural and Immunoelectron Microscopical Study of Human Pituitary Somatotroph Adenomas and Prolactinomas

Nowdays the application of immunohistochemical techniques and ultrastructuralanalysis and correlation with clinical and biochemical findings have led to a moredetailed functional classification,in which growth hormone (GH)-producing andprolactin (PRL)-producing adenomas have been shown to comprise more than halfof pituitary adenomaso.Few immunoelectron microscopic studies on GH and PRLadenomas have been made,however,in limited cases so far,though a numberof authors have described the characteristics of pituitary adenomas by conventionalelectron microscopy.In addition to routine electron microscopy,immuno-.electron microscopical technique using protein A-gold probes was applied in

Treatment and Prognosis of Pituitary Adenomas in Children

In order to explore the treatments and prognosis of pituitary adenomas in children, the experience in the treatment of 15 children with pituitary adenomas was summed up. The clinical data of 15 children with pituitary adenomas in Tongji Hospital were retrospectively analyzed from Jan. 1997 to Aug. 2004, including 9 males and 6 females with the age ranging from 9-15 years old （mean 12.8）. The disease duration was 3 months to 5 years （mean 2 years）. Fourteen cases were subjected to the microsurgical operation through oral tanssphenoidal approach and one case to medical treatment. All cases were followed up from 1 to 5 years by imaging studies and endocrine investigation. The results showed that 13 eases obtained total removal of the tumor and one subtotal removal of tumor. No severe complications and operation death occurred. It was concluded that the tanssphenoidal approach was the optimal treatment for children with pituitary adenomas. Regular and long-term follow-up is of great importance.

IN SITU PCR AND IMMUNOHISTOCHEMICAL STUDIES ON p16 GENE IN PITUITARY ADENOMAS

Objective: To examine the occurrence of p16 gene deletion and to analyze p16 expression on paraffin-embedded human pituitary adenoma specimens. Efforts were made to optimize the technical conditions forin situ PCR. Methods:In situ PCR techniques and inimuno-histochemistry were used. Results: Immunohistochemically, p16-positive tumor cells were observed in all cases with various proportions. The majority of the stromal cells and part of tumor cells was devoid of p16 immunostaining, but signal ofin situ PCR for p16 gene, exon 2, was displayed in these cells. Conclusion: The results implied that p16 gene might not be deleted in these pituitary adenomas. It also indicated thatin situ PCR, both direct and indirect methods, proved feasible and informative to the aim of DNA detection. It is critical to overcome non-specific amplification in directin situ PCR by means of higher annealing temperature, fewer cycle, lower magnesium concentration and stringent washing. A target DNA-deleted sample as the negative control is extremely necessary. For the indirect method, the way to improve the sensitivity is to loosen the conditions for amplification and washing, so that more amplification products are subject to hybridization, and signal detection is facilitated.

IN VITRO CELL CULTURE AND HORMONE RADIOIMMUNOASSAY OF HUMAN PITUITARY ADENOMAS

Tissues from 30 human pituitary adenomas are monolayer-cell-cultured in vitro.Hormone secretion of GH, PRL, TSH, LH and FSH by cells into medium is detected by radioimmunoassay. The pattern and amount of hormone(s) in the medium are used to determine the nature of the cells and thus to establish functional classification of pituitary adenomas. The results show that cell culture technique provides an easy and suitable mode for investigating the nature of pituitary adenomas. Hormone radioimmunoassay of culture medium is precise and reliable and represents the whole adenoma tissue. Further studies can lead to clearer understandings of the pathology of pituitary adenomas.

THE ROLE OF CALCIUM ION IN THE PATHOGENESIS OF HUMAN PITUITARY GH－SECRETING ADENOMAS

To study the role of Ca2+ in the pathogenesis of pituitary growth hormone secreting adenomas, the function of Ca2+ in 23 cases of human Prturtary GH-secreting adenoma was investigated in monolayer cell culture. It was found that Ca2+ channel blockers nicardipin and nifedipin inhibrted basal and growth hormone releasing hormone (GRH)stimulated GH secretion in 87. 5 % and 100. 0 % of the GH adenomas . respectively, demonstrating that in most human pituitary GH adenomas, the basal and GRH regulated GH secretion is Ca2+ dependent. The GRH and sometostatin (SRIF) agonist octreotide regulated the processes of GH secretion via Ca2+ had defects in different steps including receptor ,postreceptor Ca2+ channel and Ca2+GH secreting coupling in 6 (66. 6%) and 5 (55. 5 % ) cases of 9 GH adenomas respectively. Among them,the defects in GRH receptor and SRIF regulated Ca2+ channel are the main causes of the dysfunction of GH adenomas. These defects may be related to GH hypersecretion in GH adenomas. Our data provides advance evidences for intrinsic defects of GH adenomas.