Current Management of Head and Neck Paragangliomas: A Multicenter Series With Long-Term Follow-Up.

OBJECTIVE, STUDY DESIGN, SETTING, METHODS: To improve our knowledge about head and neck paragangliomas (HN-PGL), the clinical characteristics of all the patients with HN-PGL included in the Spanish Registry were analyzed, as well as the treatment modalities and their outcomes. RESULTS: A total of 202 patients, 67.8% women, aged 53.1 ± 17.4, with 264 HN-PGL, from 16 Spanish hospitals, were included. Tumors were located in the carotid body in 61%, jugular bulb in 20.5%, tympanic area in 10.2%, and along the vagal nerve in 6.4%. Multiple tumors developed in 20.8% and metastatic disease in 4%. A genetic study was done in 64.4% and showed a pathogenic variant in SDHx in 50%. These patients were younger, with no sex predominance, and had more multiple and metastatic tumors. Tumors were treated by surgery in 134 patients, radiotherapy in 33, and other treatments in 20, and were observed without active treatment in 41 patients, who were older, more often asymptomatic, and had smaller tumors. Tumors treated with radiotherapy were larger and more often in locations other than the carotid body. After a median follow-up of 80 months (interquartile range: 41-136), 6.9% had died; among the survivors, 48.4% were disease-free, 42.1% stable, and 9.4% had progressed. The rate of sequelae was similar among patients submitted to surgery, radiotherapy, or observation. We could not identify any prognostic factor for progression. CONCLUSION: Most HN-PGL are localized slow-growing tumors. Long-term survival is high, even in case of metastasis. Although surgery is the most common treatment, radiotherapy and active surveillance are safe approaches.

Bone loss after bariatric surgery is observed mainly in the hip trabecular compartment and after hypoabsorptive techniques.

We evaluated the impact of bariatric surgery on bone mineral density (BMD) and microarchitecture over one year using dual-energy X-ray absorptiometry (DXA), the trabecular bone score (TBS), and 3D-DXA to assess changes after different surgical techniques. This prospective, single-center study of 153 patients with severe obesity contrasts the effects on bone health of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), and duodenal switch/single anastomosis duodeno-ileostomy with sleeve gastrectomy (DS/SADIS). To our knowledge, this is the first study to evaluate patients undergoing DS/SADIS and to incorporate 3D-DXA analysis in the assessment of bone loss. Patients were 81 % female with a mean age of 50 ± 9 years. Fifty-four per cent underwent SG; 16 %, RYGB; and 30 %, DS/SADIS. Our findings revealed a significant decrease in areal BMD at the LS (-3.49 ± 5.44 %), FN (-5.24 ± 5.86 %), and TH (-8.06 ± 5.14 %) one year after bariatric surgery. Bone microarchitecture at the LS assessed by TBS was degraded in 30 % of patients. Proximal femur 3D-DXA analysis showed that surgery-induced bone loss predominantly affects the trabecular compartment (Trabecular volumetric (v) BMD: -8.00 ± 6.57 %) rather than the cortical compartment (Cortical vBMD: -1.37 ± 2.79 %). These results suggest hypoabsorptive and mixed techniques (DS/SADIS and RYGB) were associated with greater BMD loss and deterioration of microarchitecture than restrictive techniques (SG). The primary determinants of bone density and impairment of microarchitecture were the extent of weight loss and the type of surgical procedure. Despite overall bone loss, Z-score assessments indicated that post-surgical bone status remained within or above the average ranges compared to a healthy population, except for TH following DS/SADIS. In conclusion, our research shows differences in the impact of bariatric surgery techniques on bone density and microarchitecture, emphasizing the need for careful postoperative monitoring of bone health, particularly in patients undergoing hypoabsorptive and mixed procedures.

Pituitary Apoplexy: Comorbidities, Management and Outcomes. A Spanish Observational Multicenter Study.

BACKGROUND: Pituitary apoplexy (PA) is the paradigm of endocrine and neurosurgical emergency. OBJECTIVE: To evaluate the comorbidities, risk factors, clinical presentation, pituitary apoplexy score (PAS) and the outcomes of surgical vs. conservative management of PA in Spain. METHODS: Spanish multicenter, observational study of 301 patients with acute PA. Statistical analyses compared risk factors, clinical presentation and outcomes between the surgical and conservative treatment groups, adjusting for potential confounders. The prevalence of cardiovascular risk factors in patients with pituitary apoplexy was compared with the Spanish population and with patients with non-functioning pituitary adenomas. RESULTS: Median age was 59.3 years, 201 (66.8%) were men and non-functioning adenomas (77.9%) were the most common tumor type. The prevalence of diabetes (20.3% vs 13.9%, p<0.01), hypertension (48.8% vs 33.4%, p<0.01) and dyslipidemia (44.2% vs 23.3%, p<0.01), exceeded the Spanish age-adjusted population prevalence. Overall, 209 (69.4%) underwent surgery and 92 (30.6%) received conservative treatment. Surgical patients had larger tumors (26.2 vs 21.0 mm, p<0.01), chiasmal compression more frequently (77.2% vs 53.4%, p<0.01) and higher values of PAS. In the follow-up, while there were no statistically significant differences in anterior pituitary hormonal deficits between treatments, permanent vasopressin deficiency was more frequent after surgery (14.8% vs 3.3%, p<0.01). CONCLUSION: There is a high burden of cardiovascular risk factors among patients with PA suggesting that metabolic factors may play a potential role in the development of PA. This underscores the need for comprehensive management of these conditions in addition to treating the apoplexy itself in this population. Surgical management has a relevant place in PA approach mainly in patients with higher PAS. However, it leads permanent vasopressin deficit more frequently than conservative approach.

Carcinoid crisis: The challenge is still there.

Carcinoid crisis (CC) has classically been considered the extreme end of the spectrum of carcinoid syndrome (CS). However, this presumption and other aspects of CC remain poorly understood. Consequently, current clinical guidelines are based on a low quality of evidence. There is no standard definition of CC and its incidence is unknown. Patients with florid CS and elevated serotonin (or its derivatives) which develop CC have been reported during decades. Nevertheless, the hypothesis that CC is due to the sudden massive release of serotonin or other vasoactive substances is unproven. Many triggers of CC (surgery, anaesthesia, peptide receptor radionuclide therapy, tumour biopsy or liver-directed treatments) have been proposed. However, data from studies are heterogeneous and even contradictory. Finally, the role of octreotide in the prevention of CC has been questioned. Herein, we report a clinical case and perform a critical review of the evidence available today on this topic.

Intracranial hypertension secondary to unruptured pial arteriovenous malformation. Suitability of isolated endovascular treatment with ethylene vinyl alcohol/dimethyl sulfoxide (Onyx®). Case report and literature review.

A 36-year-old male presented to the Emergency Department with clinical symptoms of blurred vision of progressive onset of two years of evolution. The ophthalmological examination revealed the existence of bilateral papilledema. Using cranial computed tomography and magnetic resonance imaging, the presence of a right occipital pial arteriovenous malformation was certified. Arteriographically, pial arterial contributions dependent on the right middle cerebral artery and the right posterior cerebral artery were identified. Venous drainage was located at the level of the superior sagittal sinus. An associated right transverse sinus stenosis was also identified. The existence of secondary intracranial hypertension was corroborated by monitoring with an intracranial pressure sensor. An interventional procedure was carried out consisting of embolization of the arterial supplies of the lesion using Onyx®. The clinical-radiological findings after the procedure were favorable: the papilledema disappeared and complete exclusion of the malformation was achieved. A new intracranial pressure measurement showed resolution of intracranial hypertension. Subsequent regulated radiological controls showed complete exclusion of the malformation up to 5 years later.

Giant solitary fibrous tumor of the olfactory groove. An unusual simulator in an unusual location.

Solitary fibrous tumors are rare mesenchymal neoplasms that can develop in any part of the body, with those that settle intracranially being confused with meningiomas as a general rule. We present the case of a 57-year-old man referred to our hospital due to bifrontal headache, anosmia, and behavioral alterations of 6 months' duration. Radiological studies revealed the existence of a large tumor mass with an extra-axial appearance and location in the anterior cranial fossa, initially compatible with a giant meningioma of the olfactory groove. Gross total resection of the mass was carried out. The pathological diagnosis was unexpected: a solitary fibrous tumor (WHO grade 1, 2021). Given the aggressive nature of these lesions, with a tendency to recurrence, malignant transformation and even metastasis, surgery with macroscopically complete resection intention should constitute the first therapeutic option. Close clinical-radiological follow-up after the procedure is justified.

WRN inhibition leads to its chromatin-associated degradation via the PIAS4-RNF4-p97/VCP axis.

Synthetic lethality provides an attractive strategy for developing targeted cancer therapies. For example, cancer cells with high levels of microsatellite instability (MSI-H) are dependent on the Werner (WRN) helicase for survival. However, the mechanisms that regulate WRN spatiotemporal dynamics remain poorly understood. Here, we used single-molecule tracking (SMT) in combination with a WRN inhibitor to examine WRN dynamics within the nuclei of living cancer cells. WRN inhibition traps the helicase on chromatin, requiring p97/VCP for extraction and proteasomal degradation in a MSI-H dependent manner. Using a phenotypic screen, we identify the PIAS4-RNF4 axis as the pathway responsible for WRN degradation. Finally, we show that co-inhibition of WRN and SUMOylation has an additive toxic effect in MSI-H cells and confirm the in vivo activity of WRN inhibition using an MSI-H mouse xenograft model. This work elucidates a regulatory mechanism for WRN that may facilitate identification of new therapeutic modalities, and highlights the use of SMT as a tool for drug discovery and mechanism-of-action studies.

Natural history and surgical outcomes of Rathke's cleft cysts: a Spanish multicenter study.

Rathke's cleft cysts (RCC) are a common type of lesion found in the sellar or suprasellar area. They are usually monitored clinically, but in some cases, surgery may be required. However, their natural progression is not yet well understood, and the outcomes of surgery are uncertain. The objective of this study is to evaluate the natural history of Rathke's cleft cysts in patients who are clinically monitored without treatment, and to determine the outcomes of surgery and the incidence of recurrences over time. Design and patients: National multicentric study of patients diagnosed of Rathke's cleft cyst (RCC- Spain) from 2000 onwards and followed in 15 tertiary centers of Spain. A total of 177 patients diagnosed of RCC followed for 67.3 months (6-215) and 88 patients who underwent surgery, (81 patients underwent immediate surgery after diagnosis and 7 later for subsequent growth) followed for 68.8 months (3-235). Results: The cyst size remained stable or decreased in 73.5% (133) of the patients. Only 44 patients (24.3%) experienced a cyst increase and 9 of them (5.1%) experienced an increase greater than 3 mm. In most of the patients who underwent surgery headaches and visual alterations improved, recurrence was observed in 8 (9.1%) after a median time of 96 months, and no predictors of recurrence were discovered. Conclusions: Rathke's cleft cysts without initial compressive symptoms have a low probability of growth, so conservative management is recommended. Patients who undergo transsphenoidal surgery experience rapid clinical improvement, and recurrences are infrequent. However, they can occur after a long period of time, although no predictors of recurrence have been identified.

Glucose metabolism outcomes after pituitary surgery in patients with acromegaly.

AIM: To investigate the impact of pituitary surgery on glucose metabolism and to identify predictors of remission of diabetes after pituitary surgery in patients with acromegaly. METHODS: A national multicenter retrospective study of patients with acromegaly undergoing transsphenoidal surgery for the first time at 33 tertiary Spanish hospitals (ACRO-SPAIN study) was performed. Surgical remission of acromegaly was evaluated according to the 2000 and 2010 criteria. RESULTS: A total of 604 acromegaly patients were included in the study with a total median follow up of 91 months (interquartile range [IQR] 45-163). At the acromegaly diagnosis, 23.8% of the patients had diabetes mellitus (DM) with a median glycated hemoglobin (HbA1c) of 6.9% (IQR 6.4-7.9) [51.9 mmol/mol (IQR 46.4-62.8)]. In the multivariate analysis, older age (odds ratio [OR] 1.02, 95% CI 1.00-1.05), dyslipidemia (OR 5.25, 95% CI 2.81 to 9.79), arthropathy (OR 1.39, 95% CI 2.82 to 9.79), and higher IGF-I levels (OR 1.30, 95% CI 1.05 to 1.60) were associated with a greater prevalence of DM. At the last follow-up visit after surgery, 21.1% of the DM patients (56.7% of them with surgical remission of acromegaly) experienced diabetes remission. The cure rate of DM was more common in older patients (hazard ratio [HR] 1.77, 95% CI 1.31 to 2.43), when surgical cure was achieved (HR 2.10, 95% CI 1.01 to 4.37) and when anterior pituitary function was not affected after surgery (HR 3.38, 95% CI 1.17 to 9.75). CONCLUSION: Glucose metabolism improved in patients with acromegaly after surgery and 21% of the diabetic patients experienced diabetes remission; being more frequent in patients of older age, and those who experienced surgical cure and those with preserved anterior pituitary function after surgery.

[Thyroid surgery in a context of scarce resources at Saint Martin de Porres Dominican Hospital (Yaounde, Cameroon)]. / Chirurgie thyroïdienne dans le contexte de populations avec de faibles ressources à l'hôpital dominicain Saint Martin de Porres (Yaoundé, Cameroun).

Introduction: Surgical campaigns for thyroid surgery in low-income environments are very efficient, but there is little literature reporting results. These campaigns are complex due to multiple particularities: highly evolved cases, the need for professionals to travel or an obvious socio-cultural barrier influence towards the surgical act. We describe a surgical campaign in Cameroon to treat patients with goiter and issue some medical and sociocultural recommendations in view of our experience for its implementation with guarantees. Material and methods: An experienced group carried out an 11-day campaign at the Saint Martin de Porres Dominican Hospital, Yaounde, Cameroon. Demographic data, TSH values, surgery and complications after a 12-month follow-up were analyzed. Results: Thirty-eight patients with goiter were selected for the campaign and 32 patients (mean age, 40-years-old; 30 females) were operated. Bilateral goiter, as assessed with echography, was diagnosed in 13 patients (41%). Ten patients (31%) had a WHO grade II goiter (visible with the neck in a normal position). The surgical procedures were 18 unilateral thyroidectomy with isthmectomie, 13 total thyroidectomy, and 1 totalizing thyroidectomy, due to previous unilateral thyroidectomy (cancer recurrence). A pathological study in 13 patients (40%, extra cost 60 €) showed benign multinodular goiter/thyroid nodule (12 patients) and an extensive papillary carcinoma (one patient). Six months postoperatively, 3 patients had a slight dysphonia and one patient had persistent hypocalcemia. Follow-up was completed in all patients, either face to face (75%, 24 patients) or by phone (25%, 8 patients who failed to have a TSH test because of its cost, 23 €). Conclusions: Surgical campaigns to treat thyroid pathology can be carried out with guarantees if a series of important steps are followed: active participation of the patient's environment, thyroid ultrasound by the surgical team to decide which technique, intense awareness about monitoring and hormone replacement therapy, and the participation of local personnel for long-term follow-up.

Pegvisomant and pasireotide in PRL and GH co-secreting vs GH-secreting Pit-NETs.

The objective of the study was to evaluate the efficacy of second-line therapies in patients with acromegaly caused by a growth hormone (GH) and prolactin (PRL) co-secreting pituitary neuroendocrine tumor (GH&PRL-Pit-NET) compared to their efficacy in patients with acromegaly caused by a GH-secreting pituitary neuroendocrine tumor (GH-Pit-NET). This is a multicenter retrospective study of patients with acromegaly on treatment with pasireotide and/or pegvisomant. Patients were classified in two groups: GH&PRL-Pit-NETs when evidence of hyperprolactinemia and immunohistochemistry (IHC) for GH and PRL was positive or if PRL were >200 ng/dL regardless of the PRL-IHC and GH-Pit-NETs when the previously mentioned criteria were not met. A total of 28 cases with GH&PRL-Pit-NETs and 122 with GH-Pit-NETs met the inclusion criteria. GH&PRL-Pit-NETs presented at a younger age, caused hypopituitarism, and were invasive more frequently than GH-Pit-NETs. There were 124 patients treated with pegvisomant and 49 with pasireotide at any time. The efficacy of pegvisomant for IGF-1 normalization was of 81.5% and of pasireotide of 71.4%. No differences in IGF-1 control with pasireotide and with pegvisomant were observed between GH&PRL-Pit-NETs and GH-Pit-NETs. All GH&PRL-Pit-NET cases treated with pasireotide (n = 6) and 82.6% (n = 19/23) of the cases treated with pegvisomant normalized PRL levels. No differences in the rate of IGF-1 control between pegvisomant and pasireotide were detected in patients with GH&PRL-Pit-NETs (84.9% vs 66.7%, P = 0.178). We conclude that despite the more aggressive behavior of GH&PRL-Pit-NETs than GH-Pit-NETs, no differences in the rate of IGF-1 control with pegvisomant and pasireotide were observed between both groups, and both drugs have shown to be effective treatments to control IGF-1 and PRL hypersecretion in these tumors.

Effectiveness of combined first-line medical treatment in acromegaly with prolactin cosecretion.

OBJECTIVE: The aim of this study is to compare the response to first-line medical treatment in treatment-naive acromegaly patients with pure growth hormone (GH)-secreting pituitary adenoma (GH-PA) and those with GH and prolactin cosecreting PA (GH&PRL-PA). DESIGN: This is a retrospective multicentric study of acromegaly patients followed from 2003 to 2023 in 33 tertiary Spanish hospitals with at least 6 months of first-line medical treatment. METHODS: Baseline characteristics, first-line medical treatment strategies, and outcomes were analyzed. We employed a multiple logistic regression full model to estimate the impact of some baseline characteristics on disease control after each treatment modality. RESULTS: Of the 144 patients included, 72.9% had a GH-PA, and 27.1% had a GH&PRL-PA. Patients with GH&PRL-PA were younger (43.9 ± 15.0 vs 51.9 ± 12.7 years, P < .01) and harboring more frequently macroadenomas (89.7% vs 72.1%, P = .03). First-generation somatostatin receptor ligand (fgSRL) as monotherapy was given to 106 (73.6%) and a combination treatment with fgSRL and cabergoline in the remaining 38 (26.4%). Patients with GH&PRL-PA received more frequently a combination therapy (56.4% vs 15.2%, P < .01). After 6 months of treatment, in the group of patients under fgSRL as monotherapy, those patients with GH&PRL-PA had worse control compared to GH-PAs (29.4% vs 55.1%, P = .04). However, these differences in the rate of disease control between both groups disappeared when both received combination treatment with fgSRL and cabergoline. CONCLUSION: In GH&PRL-PA, the biochemical control achieved with fgSRL as monotherapy is substantially worse than in patients harboring GH-PA, supporting the inclusion of cabergoline as first-line medical treatment in combination with fgSRLs in these subgroups of patients.

Dynamic Workflow Proposal for Continuous Frameless Electromagnetic Neuronavigation in Rigid Neuroendoscopy.

BACKGROUND: Ventriculoscopic neuronavigation has been described in several articles. However, there are different ventriculoscopes and navigation systems. Due to these different combinations, it is difficult to find detailed neuronavigation protocols. We describe, step-by-step, a simple method to navigate both the trajectory until reaching the ventricular system, as well as the intraventricular work. METHODS: We use a rigid ventriculoscope (LOTTA, KarlStorz) with an electromagnetic stylet (S8-StealthSystem, Medtronic). The protocol is based on a modified or 3-dimensionally printed trocar for navigating the extraventricular step and on a modified pediatric nasogastric tube for the intraventricular navigation. RESULTS: This protocol can be set up in less than 10 minutes. The extraventricular part is navigated by introducing the electromagnetic stylet inside the modified or 3-dimensionally printed trocar. Intraventricular navigation is done by combining a modified pediatric nasogastric tube with the electromagnetic stylet inside the endoscope's working channel. The most critical point is to obtain a blunt-bloodless ventriculostomy while achieving perfect alignment of all targeted structures via pure straight trajectories. CONCLUSIONS: This protocol is easy-to-set-up, avoids head rigid-fixation and bulky optical-based attachments to the ventriculoscope, and allows continuous navigation of both parts of the surgery. Since we have implemented this protocol, we have noticed a significant enhancement in both simple and complex ventriculoscopic procedures because the surgery is dramatically simplified.

Heterogeneity of SOS response expression in clinical isolates of Escherichia coli influences adaptation to antimicrobial stress.

In recent years, new evidence has shown that the SOS response plays an important role in the response to antimicrobials, with involvement in the generation of clinical resistance. Here we evaluate the impact of heterogeneous expression of the SOS response in clinical isolates of Escherichia coli on response to the fluoroquinolone, ciprofloxacin. In silico analysis of whole genome sequencing data showed remarkable sequence conservation of the SOS response regulators, RecA and LexA. Despite the genetic homogeneity, our results revealed a marked differential heterogeneity in SOS response activation, both at population and single-cell level, among clinical isolates of E. coli in the presence of subinhibitory concentrations of ciprofloxacin. Four main stages of SOS response activation were identified and correlated with cell filamentation. Interestingly, there was a correlation between clinical isolates with higher expression of the SOS response and further progression to resistance. This heterogeneity in response to DNA damage repair (mediated by the SOS response) and induced by antimicrobial agents could be a new factor with implications for bacterial evolution and survival contributing to the generation of antimicrobial resistance.

Differences between GH and PRL co-secreting and GH-secreting pituitary adenomas. A series of 604 cases.

PURPOSE: To evaluate differences in clinical presentation and in surgical outcomes between growth hormone-secreting pituitary adenomas (GH-PAs) and GH and prolactin co-secreting pituitary adenomas (GH&PRL-PAs). METHODS: Multicenter retrospective study of 604 patients with acromegaly submitted to pituitary surgery. Patients were classified into two groups according to serum PRL levels at diagnosis and immunohistochemistry (IHC) for PRL: a) GH&PRL-PAs when PRL levels were above the upper limit of normal and IHC for GH and PRL was positive or PRL levels were >100ng/and PRL IHC was not available (n=130) and b) GH-PAs who did not meet the previously mentioned criteria (n=474). RESULTS: GH&PRL-PAs represented 21.5% (n=130) of patients with acromegaly. The mean age at diagnosis was lower in GH&PRL-PAs than in GH-PAs (P<0.001). GH&PRL-PAs were more frequently macroadenomas (90.6% vs. 77.4%, P=0.001) and tended to be more invasive (33.6% vs. 24.7%, P=0.057) than GH-PAs. Furthermore, they had presurgical hypopituitarism more frequently (OR 2.8, 95% CI 1.83-4.38). IGF-1 upper limit of normality (ULN) levels at diagnosis were lower in patients with GH&PRL-PAs (median 2.4 [IQR 1.73-3.29] vs. 2.7 [IQR 1.91-3.67], P=0.023). There were no differences in the immediate (41.1% vs 43.3%, P=0.659) or long-term post-surgical acromegaly biochemical cure rate (53.5% vs. 53.1%, P=0.936) between groups. However, there was a higher incidence of permanent arginine-vasopressin deficiency (AVP-D) (7.3% vs. 2.4%, P=0.011) in GH&PRL-PAs patients. CONCLUSIONS: GH&PRL-PAs are responsible for 20% of acromegaly cases. These tumors are more invasive, larger and cause hypopituitarism more frequently than GH-PAs and are diagnosed at an earlier age. The biochemical cure rate is similar between both groups, but patients with GH&PRL-PAs tend to develop permanent postsurgical AVP-D more frequently.

Transcortical transcatheter ultrasound-assisted technique for deep-seated brain tumors. Technical note.

PURPOSE: Surgery of deep-seated brain tumors can be challenging. Several methods have been described to facilitate transcortical approaches, including ultrasound-assisted resection. Ultrasound-guided placement of a standard ventricular catheter is a widely reported technique and has been used to approach these lesions via the transcortical route. We describe how we usually perform this useful technique to assist and enhance the transcortical resection of some deep-seated brain tumors. METHODS: Standard electromagnetic frameless navigation (S8 Neuronavigation System, Medtronic, Minneapolis, USA) was employed to focus the craniotomy and to plan the trajectory of the ventricular catheter. After dural opening, an ultrasound device (Arietta 850, Hitachi-Aloka Medical, Tokyo, Japan) was used for intraoperative ultrasound (IOUS) assessment. A ventricular catheter was placed from the cortex to the lateral wall of the tumor under direct real-time IOUS visualization to guide the further transcortical dissection. RESULTS: Transcortical transcatheter ultrasound-assisted technique involved minimal time and infrastructure requirements. There were no major technical difficulties during its use, providing confidence and improving subcortical white matter dissection by guiding the route to the tumor. CONCLUSIONS: Recent improvement of IOUS image-quality devices offers several attractive options for real-time navigation. The combination of conventional neuronavigation systems with real-time IOUS assessment during the intradural step provides a higher degree of control by improving the execution of the surgery. We hope this description may be a useful tool for some selected cases and contribute to the further enhancement and improvement of this widely used technique.

Structural, biochemical and immunochemical characterization of an acidic phospholipase A2 from Lachesis acrochorda (Viperidae: Crotalinae) venom.

Viperids of the genus Lachesis, also known as bushmasters, are capable of injecting great amounts of venom that cause severe envenomation incidents. Since phospholipases type A2 are mainly involved in edema and myonecrosis within the snakebite sites, in this work, the isolation, amino acid sequence and biochemical characterization of the first phospholipase type A2 from the venom of Lachesis acrochorda, named Lacro_PLA2, is described. Lacro_PLA2 is an acidic aspartic 49 calcium-dependent phospholipase A2 with 93% similarity to the L. stenophrys phospholipase. Lacro_PLA2 has a molecular mass of 13,969.7 Da and an experimental isoelectric point around 5.3. A combination of N-terminal Edman degradation and MS/MS spectrometry analyses revealed that Lacro_PLA2 contains 122 residues including 14 cysteines that form 7 disulfide bridges. A predicted 3D model shows a high resemblance to other viperid phospholipases. Nevertheless, immunochemical and phospholipase neutralization tests revealed a notorious level of immunorecognition of the isolated protein by two polyclonal antibodies from viperids from different genus, which suggest that Lacro_PLA2 resembles more to bothropic phospholipases. Lacro_PLA2 also showed significantly high edema activity when was injected into mice; so, it could be an alternative antigen in the development of antibodies against toxins of this group of viperids, seeking to improve commercial polyclonal antivenoms.

Clinical Significance of T2-Weighted Sequence Intensity on Magnetic Resonance Imaging in Clinically Non-Functioning Pituitary Adenomas.

BACKGROUND: Little is known about the relationship between signal intensity patterns on T2-weighted magnetic resonance imaging (MRI) in non-functioning pituitary adenomas (NFPAs). OBJECTIVE: In this study, the clinical, hormonal, histological features, and therapeutic responses were evaluated according to the T2 signal intensity in NFPAs. METHODS: This retrospective and multicenter study included a group of 166 NFPA patients (93 men, 56%, mean age 58.5 ±14.8 yr). RESULTS: Approximately half of the tumors (n=84, 50.6%) were hyperintense, while 34.3% (n=57) and 15.1% (n=25) were iso- and hypointense, respectively. The median maximum tumor diameter of the isointense group [16 (13-25) mm] was significantly lower than that of the hyperintense [23 (16.6-29.7) mm] group (p=0.003). Similarly, the tumor volume of the isointense group [1,523 (618-5,226) mm3] was significantly lower than that of the hyperintense [4,012 (2,506-8,320) mm3] group (p=0.002). Chiasmatic compression occurred less frequently in tumors with isointense signal characteristics (38.6%) compared to tumors with hypointense (68%) and hyperintense (65.5%) signal characteristics (p=0.003). Invasive adenomas (p=0.001) and the degree of cavernous sinus invasion (p<0.001) were more frequent in the hyperintense adenoma group compared to the remaining groups. Plurihormonal tumors and silent lactotroph adenomas were more frequent in the isointense tumor group. CONCLUSION: In conclusion, hyperintensity on T2-weighted MRI in NFPAs is associated with larger and more invasive tumors compared to isointense NFPAs.