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1.
Cereb Cortex ; 33(7): 3944-3959, 2023 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-36104852

RESUMO

The claustrum is known for its extensive connectivity with many other forebrain regions, but its elongated shape and deep location have made further study difficult. We have sought to understand when mouse claustrum neurons are born, where they are located in developing brains, and when they develop their widespread connections to the cortex. We established that a well-characterized parvalbumin plexus, which identifies the claustrum in adults, is only present from postnatal day (P) 21. A myeloarchitectonic outline of the claustrum can be derived from a triangular fiber arrangement from P15. A dense patch of Nurr1+ cells is present at its core and is already evident at birth. Bromodeoxyuridine birth dating of forebrain progenitors reveals that the majority of claustrum neurons are born during a narrow time window centered on embryonic day 12.5, which is later than the adjacent subplate and endopiriform nucleus. Retrograde tracing revealed that claustrum projections to anterior cingulate (ACA) and retrosplenial cortex (RSP) follow distinct developmental trajectories. Claustrum-ACA connectivity matures rapidly and reaches adult-like innervation density by P10, whereas claustrum-RSP innervation emerges later over a protracted time window. This work establishes the timeline of claustrum development and provides a framework for understanding how the claustrum is built and develops its unique connectivity.


Assuntos
Claustrum , Camundongos , Animais , Gânglios da Base/fisiologia , Vias Neurais/fisiologia , Giro do Cíngulo , Neurônios
2.
Cereb Cortex ; 32(12): 2538-2554, 2022 06 07.
Artigo em Inglês | MEDLINE | ID: mdl-34613375

RESUMO

Mammalian neocortex is important for conscious processing of sensory information with balanced glutamatergic and GABAergic signaling fundamental to this function. Yet little is known about how this interaction arises despite increasing insight into early GABAergic interneuron (IN) circuits. To study this, we assessed the contribution of specific INs to the development of sensory processing in the mouse whisker barrel cortex, specifically the role of INs in early speed coding and sensory adaptation. In wild-type animals, both speed processing and adaptation were present as early as the layer 4 critical period of plasticity and showed refinement over the period leading to active whisking onset. To test the contribution of IN subtypes, we conditionally silenced action-potential-dependent GABA release in either somatostatin (SST) or vasoactive intestinal peptide (VIP) INs. These genetic manipulations influenced both spontaneous and sensory-evoked cortical activity in an age- and layer-dependent manner. Silencing SST + INs reduced early spontaneous activity and abolished facilitation in sensory adaptation observed in control pups. In contrast, VIP + IN silencing had an effect towards the onset of active whisking. Silencing either IN subtype had no effect on speed coding. Our results show that these IN subtypes contribute to early sensory processing over the first few postnatal weeks.


Assuntos
Córtex Somatossensorial , Vibrissas , Animais , Interneurônios/fisiologia , Mamíferos/metabolismo , Camundongos , Percepção , Córtex Somatossensorial/fisiologia , Peptídeo Intestinal Vasoativo/metabolismo , Vibrissas/fisiologia
3.
J Neurosci ; 41(5): 813-822, 2021 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-33431633

RESUMO

The sensory and cognitive abilities of the mammalian neocortex are underpinned by intricate columnar and laminar circuits formed from an array of diverse neuronal populations. One approach to determining how interactions between these circuit components give rise to complex behavior is to investigate the rules by which cortical circuits are formed and acquire functionality during development. This review summarizes recent research on the development of the neocortex, from genetic determination in neural stem cells through to the dynamic role that specific neuronal populations play in the earliest circuits of neocortex, and how they contribute to emergent function and cognition. While many of these endeavors take advantage of model systems, consideration will also be given to advances in our understanding of activity in nascent human circuits. Such cross-species perspective is imperative when investigating the mechanisms underlying the dysfunction of early neocortical circuits in neurodevelopmental disorders, so that one can identify targets amenable to therapeutic intervention.


Assuntos
Neocórtex/citologia , Neocórtex/crescimento & desenvolvimento , Rede Nervosa/citologia , Rede Nervosa/crescimento & desenvolvimento , Células-Tronco Neurais/fisiologia , Neurônios/fisiologia , Animais , Humanos , Lógica
4.
Intern Med J ; 52(5): 864-867, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35451543

RESUMO

Computed tomography colonography (CTC) is a safe and accurate tool for colorectal cancer (CRC) screening in both symptomatic and asymptomatic patients. CTC requires dedicated radiological expertise and demonstrates a high sensitivity and specificity in polyp detection, which is similar to optical colonoscopy (OC). Newer preparation techniques for CTC, such as faecal tagging without catharsis might further improve both the tolerability and accuracy of the test. While exposure to ionising radiation, lack of capacity for therapeutic intervention and potentially diminished sensitivity for flat serrated polyps are limitations of CTC, the technique has a role in select populations. CTC should be considered in frail or elderly patients at high anaesthetic risk for OC, patients with stricturing colonic lesions as well as incomplete colonoscopy, or in patients at risk of delayed access to timely OC. With an ever-growing demand for endoscopic services, increased utilisation of CTC could reduce waiting times for colonoscopy, thereby broadening access to timely and effective CRC screening. Further research is required to improve further the detection of flat lesions, including sessile serrated polyps.


Assuntos
Pólipos do Colo , Colonografia Tomográfica Computadorizada , Neoplasias Colorretais , Idoso , Pólipos do Colo/diagnóstico , Colonografia Tomográfica Computadorizada/métodos , Colonoscopia/métodos , Neoplasias Colorretais/diagnóstico , Computadores , Humanos , Sensibilidade e Especificidade , Tomografia
5.
Clin Endocrinol (Oxf) ; 94(3): 413-423, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33340135

RESUMO

OBJECTIVE: To report the clinical presentation, management and outcomes of young patients with prolactinomas (<20 years) and conduct a systematic review and meta-analysis. PATIENTS AND DESIGN: Clinical, biochemical and radiological data (1996-2018) were collected from our centre. A systematic review and meta-analysis of published literature (1994-2019) on prolactinoma (age <20 years) were conducted. Both random and fixed effects meta-analysis were used to pool outcomes across studies. RESULTS 1 CASE SERIES: Twenty-two patients (14 females) were identified; median age at diagnosis 15.7 years (range 13-19); 12 patients (6 females) had a macroprolactinoma. Seven patients (macroprolactinoma-6) had associated pituitary hormone deficiencies at presentation. Five patients (4 males) underwent surgical resection due to poor response to cabergoline or apoplexy. Patients undergoing surgery had larger tumours (p < .02) and higher serum prolactin concentration (p < .005). All patients with macroprolactinoma >20 mm required surgical intervention. RESULTS 2 SYSTEMATIC REVIEW AND META-ANALYSIS: We selected 11 studies according to strict inclusion criteria describing 275 patients. Macroprolactinoma was more common in girls (78.7% [95% CI 70.5-85.9]) than boys and was more frequent than microprolactinoma (56.6% [95% CI 48.4-64.5]). In males, only 6/57 (10.5%) of tumours were microprolactinoma as compared to 102/198 (51.5%) microprolactinoma in females (risk difference -0.460; [95% CI -0.563 to -0.357]; p < .001). Surgery was first-line therapy in 18.9% patients, with another 15.4% requiring it as a second line (overall 31.3%). CONCLUSIONS: Macroprolactinoma, particularly if >20 mm, usually requires multimodal therapy including surgical intervention. While overall prolactinomas in <20 years age group are more common in females, the proportion of macroprolactinoma vs microprolactinoma is greater in males, particularly for large invasive tumours. Microprolactinoma is a rare diagnosis in adolescent males.


Assuntos
Neoplasias Hipofisárias , Prolactinoma , Adolescente , Adulto , Fatores Etários , Cabergolina , Agonistas de Dopamina , Feminino , Humanos , Masculino , Neoplasias Hipofisárias/patologia , Neoplasias Hipofisárias/terapia , Prolactina , Prolactinoma/patologia , Prolactinoma/terapia , Adulto Jovem
6.
Pituitary ; 23(6): 641-647, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32857272

RESUMO

PURPOSE: Moderate hyperprolactinaemia (2-5 times upper limit of normal) occurring in a patient with a normal pituitary MRI is generally considered to be due to a lesion below the level of detection of the MRI scanner assuming macroprolactin and stress have been excluded. Most patients with mild-to-moderate hyperprolactinaemia and a normal MRI respond to dopamine agonist therapy. We present the rare case of a patient who had prolactin elevation typical of a prolactin-secreting pituitary macroadenoma,with a normal cranial MRI, and in whom the prolactin rose further with dopamine agonist treatment. Subsequent investigations revealed ectopic hyperprolactinaemia to a uterine tumor resembling ovarian sex cord tumor (UTROSCT) which resolved following tumor resection. Although mostly considered to be benign, the UTROSCT recurred with recurrent hyperprolactinaemia and intraabdominal metastases. METHODS: We have systematically and critically reviewed existing literature relating to ectopic hyperprolactinaemia in general and UTROCST specifically. RESULTS: Fewer than 80 cases of UTROSCTs have been reported globally of which about 23% have shown malignant behaviour. There are fewer than 10 cases of paraneoplastic hyperprolactinaemia originating from uterine neoplasms including one other case of ectopic hyperprolactinaemia to a UTROSCT. CONCLUSIONS: Our case demonstrates the importance of screening for extracranial hyperprolactinaemia in the context of: (1) substantially raised prolactin (10× ULN) and (2) normal cranial MRI assuming macroprolactin has been excluded. The majority of extracranial ectopic prolactin-secreting tumors occur in the reproductive organs.


Assuntos
Hiperprolactinemia/patologia , Neoplasias Uterinas/patologia , Adulto , Agonistas de Dopamina/uso terapêutico , Feminino , Humanos , Hiperprolactinemia/tratamento farmacológico , Imuno-Histoquímica , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Prolactinoma/tratamento farmacológico , Prolactinoma/patologia , Neoplasias Uterinas/tratamento farmacológico
7.
J Physiol ; 596(2): 145-162, 2018 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-29110301

RESUMO

An important consideration when probing the function of any neuron is to uncover the source of synaptic input onto the cell, its intrinsic physiology and efferent targets. Over the years, electrophysiological approaches have generated considerable insight into these properties in a variety of cortical neuronal subtypes and circuits. However, as researchers explore neuronal function in greater detail, they are increasingly turning to optical techniques to bridge the gap between local network interactions and behaviour. The application of optical methods has increased dramatically over the past decade, spurred on by the optogenetic revolution. In this review, we provide an account of recent innovations, providing researchers with a primer detailing circuit mapping strategies in the cerebral cortex. We will focus on technical aspects of performing neurotransmitter uncaging and channelrhodopsin-assisted circuit mapping, with the aim of identifying common pitfalls that can negatively influence the collection of reliable data.


Assuntos
Mapeamento Encefálico/métodos , Córtex Cerebral/fisiologia , Neurônios/fisiologia , Optogenética , Animais , Córtex Cerebral/citologia , Humanos , Neurônios/citologia , Transmissão Sináptica
9.
ACS Chem Neurosci ; 15(3): 456-461, 2024 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-38251903

RESUMO

The recent development of genetically encoded fluorescent neurotransmitter biosensors has opened the door to recording serotonin (5-hydroxytryptamine, 5-HT) signaling dynamics with high temporal and spatial resolution in vivo. While this represents a significant step forward for serotonin research, the utility of available 5-HT biosensors remains to be fully established under diverse in vivo conditions. Here, we used two-photon microscopy in awake mice to examine the effectiveness of specific 5-HT biosensors for monitoring 5-HT dynamics in somatosensory cortex. Initial experiments found that whisker stimulation evoked a striking change in 5-HT biosensor signal. However, similar changes were observed in controls expressing green fluorescent protein, suggesting a potential hemodynamic artifact. Subsequent use of a second control fluorophore with emission peaks separated from the 5-HT biosensor revealed a reproducible, stimulus-locked increase in 5-HT signal. Our data highlight the promise of 5-HT biosensors for in vivo application, provided measurements are carried out with appropriate optical controls.


Assuntos
Neocórtex , Serotonina , Camundongos , Animais , Serotonina/metabolismo , Microscopia , Neocórtex/metabolismo , Transdução de Sinais , Neurotransmissores/metabolismo , Mamíferos/metabolismo
10.
Endocr Connect ; 13(3)2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38236710

RESUMO

Introduction: Adrenocortical carcinoma (ACC) is a rare malignancy of the adrenal cortex. Whilst surgery is the preferred treatment, adjunctive therapy with mitotane may be offered post-surgically to minimise the risk of recurrence or, in the absence of surgery, to attenuate progression. Aim: The objective was to evaluate the effects of mitotane treatment on serum protein concentrations in patients treated for ACC with mitotane therapy and compare this to patients with other adrenal neoplasms and a normal pregnant cohort. Methods: Serum cortisol, thyroid function tests, adrenocorticotrophic hormone (ACTH), cortisol-binding globulin (CBG), thyroxine-binding globulin (TBG), gonadotrophins and androgens were measured on plasma and serum samples. Thirty-five patients with ACC were included, and mitotane levels were noted to be sub-/supra-therapeutic. Data were tested for normality, reported as mean ± s.d., and compared to other two cohorts using paired-sample t-test with a 5% P-value for significance and a 95% CI. Results: Patients on mitotane therapy had a higher mean serum CBG concentration compared to the adrenal neoplasm group (sub-therapeutic: 79.5 (95% CI: 33.6, 125.4 nmol/L), therapeutic: 85.3 (95% CI: 37.1-133.6 nmol/L), supra-therapeutic: 75.7 (95% CI: -19.3, 170.6 nmol/L) and adrenal neoplasm: 25.5 (95% CI: 17.5, 33.5 nmol/L). Negative correlations between serum cortisol and CBG concentration were demonstrated within the supra-therapeutic plasma mitotane and adrenal neoplasm groups. Conclusion: Patients with ACC and therapeutic plasma mitotane concentrations had higher serum CBG concentrations compared to those with adrenal neoplasms or pregnant women, and higher serum cortisol. Whilst there was no direct correlation with cortisol and mitotane level, the negative correlation of cortisol with CBG may suggest that the direct effect of mitotane in increasing cortisol may also reflect that mitotane has a direct adrenolytic effect.

11.
J Neurosci ; 32(38): 13085-99, 2012 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-22993426

RESUMO

The integration of neurons within the developing cerebral cortex is a prolonged process dependent on a combination of molecular and physiological cues. To examine the latter we used laser scanning photostimulation (LSPS) of caged glutamate in conjunction with whole-cell patch-clamp electrophysiology to probe the integration of pyramidal cells in the sensorimotor regions of the mouse neocortex. In the days immediately after postnatal day 5 (P5) the origin of the LSPS-evoked AMPA receptor (AMPAR)-mediated synaptic inputs were diffuse and poorly defined with considerable variability between cells. Over the subsequent week this coalesced and shifted, primarily influenced by an increased contribution from layers 2/3 cells, which became a prominent motif of the afferent input onto layer 5 pyramidal cells regardless of cortical region. To further investigate this particular emergent translaminar connection, we alternated our mapping protocol between two holding potentials (-70 and +40 mV) allowing us to detect exclusively NMDA receptor (NMDAR)-mediated inputs. This revealed distal MK-801-sensitive synaptic inputs that predict the formation of the mature, canonical layer 2/3 to 5 pathway. However, these were a transient feature and had been almost entirely converted to AMPAR synapses at a later age (P16). To examine the role of activity in the recruitment of early NMDAR synapses, we evoked brief periods (20 min) of rhythmic bursting. Short intense periods of activity could cause a prolonged augmentation of the total input onto pyramidal cells up until P12; a time point when the canonical circuit has been instated and synaptic integration shifts to a more consolidatory phase.


Assuntos
Córtex Motor/crescimento & desenvolvimento , Neocórtex/citologia , Neocórtex/crescimento & desenvolvimento , Vias Neurais/crescimento & desenvolvimento , Células Piramidais/fisiologia , Sinapses/fisiologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Fatores Etários , Animais , Animais Recém-Nascidos , Bicuculina/farmacologia , Biofísica , Mapeamento Encefálico , Maleato de Dizocilpina/farmacologia , Relação Dose-Resposta a Droga , Estimulação Elétrica , Antagonistas de Aminoácidos Excitatórios/farmacologia , Potenciais Pós-Sinápticos Excitadores/efeitos dos fármacos , Antagonistas de Receptores de GABA-A/farmacologia , Glutamatos/farmacologia , Técnicas In Vitro , Lasers , Magnésio/farmacologia , Camundongos , Neocórtex/metabolismo , Técnicas de Patch-Clamp , Estimulação Luminosa/instrumentação , Estimulação Luminosa/métodos , Células Piramidais/efeitos dos fármacos , Estatísticas não Paramétricas , Sinapses/efeitos dos fármacos , Fatores de Tempo
12.
Endocr Relat Cancer ; 30(4)2023 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-36621911

RESUMO

Parathyroid carcinoma is one of the least common endocrine malignancies and accounts for approximately 1% of all patients with primary hyperparathyroidism. A systematic review of peer-reviewed literature published between January 2000 and March 2022 via Medline, Embase, Cochrane Central Register of Controlled Trials, EudraCT, ClinicalTrials.gov, CINAHL and SCOPUS was conducted. Manuscripts were eligible if they included data on adult non-pregnant populations with parathyroid carcinoma. No restrictions regarding interventions, comparators or duration of follow-up were imposed. Single case reports, reviews or meta-analyses were excluded. Outcomes of interest were molecular pathogenesis, clinical presentation, differential diagnosis, treatment, follow-up and overall survival. Study quality was evaluated using the Newcastle-Ottawa Scale for observational studies. This review included 75 studies from 17 countries, reporting on more than 3000 patients with parathyroid carcinoma. CDC73 mutation has been recognised as playing a pivotal role in molecular pathogenesis. Parathyroid carcinoma typically presents with markedly increased calcium and parathyroid hormone levels. The most frequently described symptoms were bone and muscle pain or weakness. En bloc resection remains the gold standard for the surgical approach. The 5-year overall survival ranged from 60 to 93%, with resistant hypercalcaemia a significant cause of mortality. Emerging evidence indicating that targeted therapy, based on molecular biomarkers, presents a novel treatment option. The rarity of PC and need for personalised treatment warrant multidisciplinary management in a 'centre of excellence' with a track record in PC management.


Assuntos
Neoplasias das Paratireoides , Adulto , Humanos , Neoplasias das Paratireoides/diagnóstico , Neoplasias das Paratireoides/genética , Neoplasias das Paratireoides/terapia
13.
Obesity (Silver Spring) ; 31(1): 20-30, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36502288

RESUMO

OBJECTIVE: Postprandial hyperinsulinemic hypoglycemia with neuroglycopenia is an increasingly recognized complication of Roux-en-Y gastric bypass and gastric sleeve surgery that may detrimentally affect patient quality of life. One likely causal factor is glucagon-like peptide-1 (GLP-1), which has an exaggerated rise following ingestion of carbohydrates after bariatric surgery. This paper sought to assess the role of GLP-1 receptor agonists (GLP-1RAs) in managing postprandial hypoglycemia following bariatric surgery. METHODS: MEDLINE, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials.gov, and Scopus were systematically and critically appraised for all peer-reviewed publications that suitably fulfilled the inclusion criteria established a priori. This systematic review was developed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols (PRISMA-P). It followed methods outlined in the Cochrane Handbook for Systematic Reviews of Interventions and is registered with PROSPERO (International Prospective Register of Systematic Reviews; identifier CRD420212716429). RESULTS AND CONCLUSIONS: Postprandial hyperinsulinemic hypoglycemia remains a notoriously difficult to manage metabolic complication of bariatric surgery. This first, to the authors' knowledge, systematic review presents evidence suggesting that use of GLP-1RAs does not lead to an increase of hypoglycemic episodes, and, although this approach may appear counterintuitive, the findings suggest that GLP-1RAs could reduce the number of postprandial hypoglycemic episodes and improve glycemic variability.


Assuntos
Cirurgia Bariátrica , Receptor do Peptídeo Semelhante ao Glucagon 1 , Hipoglicemia , Humanos , Cirurgia Bariátrica/efeitos adversos , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Receptor do Peptídeo Semelhante ao Glucagon 1/uso terapêutico , Hipoglicemia/etiologia , Hipoglicemia/prevenção & controle , Qualidade de Vida
14.
Nature ; 440(7081): 215-9, 2006 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-16525473

RESUMO

The neuronal networks that generate vertebrate movements such as walking and swimming are embedded in the spinal cord. These networks, which are referred to as central pattern generators (CPGs), are ideal systems for determining how ensembles of neurons generate simple behavioural outputs. In spite of efforts to address the organization of the locomotor CPG in walking animals, little is known about the identity and function of the spinal interneuron cell types that contribute to these locomotor networks. Here we use four complementary genetic approaches to directly address the function of mouse V1 neurons, a class of local circuit inhibitory interneurons that selectively express the transcription factor Engrailed1. Our results show that V1 neurons shape motor outputs during locomotion and are required for generating 'fast' motor bursting. These findings outline an important role for inhibition in regulating the frequency of the locomotor CPG rhythm, and also suggest that V1 neurons may have an evolutionarily conserved role in controlling the speed of vertebrate locomotor movements.


Assuntos
Locomoção/fisiologia , Neurônios Motores/fisiologia , Medula Espinal/citologia , Medula Espinal/fisiologia , Potenciais de Ação , Animais , Proteínas do Olho/genética , Deleção de Genes , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Interneurônios/fisiologia , Locomoção/genética , Camundongos , Fator de Transcrição PAX6 , Fatores de Transcrição Box Pareados/deficiência , Fatores de Transcrição Box Pareados/genética , Receptores de Neuropeptídeos/metabolismo , Proteínas Repressoras/genética , Fatores de Tempo , Transgenes/genética , Caminhada/fisiologia
15.
Artigo em Inglês | MEDLINE | ID: mdl-35264463

RESUMO

Summary: A 49-year-old teacher presented to his general physician with lethargy and lower limb weakness. He had noticed polydipsia, polyuria, and had experienced weight loss, albeit with an increase in central adiposity. He had no concomitant illnesses and took no regular medications. He had hypercalcaemia (adjusted calcium: 3.34 mmol/L) with hyperparathyroidism (parathyroid hormone: 356 ng/L) and hypokalaemia (K: 2.7 mmol/L) and was admitted for i.v. potassium replacement. A contrast-enhanced CT chest/abdomen/pelvis scan revealed a well-encapsulated anterior mediastinal mass measuring 17 × 11 cm with central necrosis, compressing rather than invading adjacent structures. A neck ultrasound revealed a 2 cm right inferior parathyroid lesion. On review of CT imaging, the adrenals appeared normal, but a pancreatic lesion was noted adjacent to the uncinate process. His serum cortisol was 2612 nmol/L, and adrenocorticotrophic hormone was elevated at 67 ng/L, followed by inadequate cortisol suppression to 575 nmol/L from an overnight dexamethasone suppression test. His pituitary MRI was normal, with unremarkable remaining anterior pituitary biochemistry. His admission was further complicated by increased urine output to 10 L/24 h and despite three precipitating factors for the development of diabetes insipidus including hypercalcaemia, hypokalaemia, and hypercortisolaemia, due to academic interest, a water deprivation test was conducted. An 18flurodeoxyglucose-PET (FDG-PET) scan demonstrated high avidity of the mediastinal mass with additionally active bilateral superior mediastinal nodes. The pancreatic lesion was not FDG avid. On 68Ga DOTATE-PET scan, the mediastinal mass was moderately avid, and the 32 mm pancreatic uncinate process mass showed significant uptake. Genetic testing confirmed multiple endocrine neoplasia type 1. Learning points: In young patients presenting with primary hyperparathyroidism, clinicians should be alerted to the possibility of other underlying endocrinopathies. In patients with multiple endocrine neoplasia type 1 (MEN-1) and ectopic adrenocorticotrophic hormone syndrome (EAS), clinicians should be alerted to the possibility of this originating from a neoplasm above or below the diaphragm. Although relatively rare compared with sporadic cases, thymic carcinoids secondary to MEN-1 may also be associated with EAS. Electrolyte derangement, in particular hypokalaemia and hypercalcaemia, can precipitate mild nephrogenic diabetes insipidus.

16.
Int J Endocrinol ; 2022: 7360282, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35465075

RESUMO

Objective: The insulin tolerance test (ITT) is the gold standard endocrine test used to assess the integrity of the growth hormone (GH) and cortisol axes. The ITT has potential risks, and severe hypoglycaemia may necessitate intravenous glucose rescue. There is no clear consensus as to the optimal insulin dose for the ITT. Therefore, we sought to compare the standard dose (0.15 U/kg) and a low-dose ITT (0.1 U/kg). Design: Single-centre audit of ITT data (2012-2021). Patients and Measurements. Patients who underwent an ITT to assess possible GH deficiency/adrenal insufficiency were included. Glucose, GH, and cortisol were measured at baseline and 30, 45, 60, 90, and 120 minutes following I.V. insulin bolus (0.15 U/kg or 0.10 U/kg). Results: Of the ITTs performed, only 3/177 (1.7%) did not achieve adequate hypoglycaemia (≤2.2 mmol/L) with a single insulin dose. In total, 174 patients (43.5 ± 12.1 yrs, mean ± standard deviation) were included for analysis (0.15 U/kg: n = 113, 0.10 U/kg: n = 61). All 174 subjects had adequate hypoglycaemia regardless of baseline fasting blood glucose level or insulin dose. Neither nadir glucose nor glucose delta (i.e., baseline minus nadir) differed between insulin doses. Trends in both cortisol and GH responses over time were similar between groups, and a greater proportion of patients receiving the standard dose had an adequate cortisol response (77/106 (72.6%) vs. 32/60 (53.3%), p=0.01). The rates of glucose rescue did not differ in a subset of 79 patients, with on-demand glucose rescue in 4/35 (11%) for the standard dose and 2/44 (5%) for the low dose (p=0.25). Conclusions: Our results suggest that the low-dose ITT produces comparable glucose, cortisol, and GH responses to the higher dose. Given the risks associated with hypoglycaemia, the low dose appears to be preferable to the standard dose ITT in most circumstances.

17.
J Neurosci ; 30(5): 1582-94, 2010 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-20130169

RESUMO

By combining an inducible genetic fate mapping strategy with electrophysiological analysis, we have systematically characterized the populations of cortical GABAergic interneurons that originate from the caudal ganglionic eminence (CGE). Interestingly, compared with medial ganglionic eminence (MGE)-derived cortical interneuron populations, the initiation [embryonic day 12.5 (E12.5)] and peak production (E16.5) of interneurons from this embryonic structure occurs 3 d later in development. Moreover, unlike either pyramidal cells or MGE-derived cortical interneurons, CGE-derived interneurons do not integrate into the cortex in an inside-out manner but preferentially (75%) occupy superficial cortical layers independent of birthdate. In contrast to previous estimates, CGE-derived interneurons are both considerably greater in number (approximately 30% of all cortical interneurons) and diversity (comprised by at least nine distinct subtypes). Furthermore, we found that a large proportion of CGE-derived interneurons, including the neurogliaform subtype, express the glycoprotein Reelin. In fact, most CGE-derived cortical interneurons express either Reelin or vasoactive intestinal polypeptide. Thus, in conjunction with previous studies, we have now determined the spatial and temporal origins of the vast majority of cortical interneuron subtypes.


Assuntos
Linhagem da Célula/genética , Córtex Cerebral/citologia , Técnicas Genéticas , Interneurônios/citologia , Animais , Padronização Corporal/genética , Moléculas de Adesão Celular Neuronais/metabolismo , Diferenciação Celular/genética , Córtex Cerebral/embriologia , Córtex Cerebral/metabolismo , Córtex Cerebral/fisiologia , Proteínas da Matriz Extracelular/metabolismo , Marcadores Genéticos , Interneurônios/metabolismo , Interneurônios/fisiologia , Masculino , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Técnicas de Patch-Clamp , Prosencéfalo/citologia , Prosencéfalo/fisiologia , Proteína Reelina , Serina Endopeptidases/metabolismo
18.
Eur J Neurosci ; 34(10): 1542-52, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22103412

RESUMO

The locally projecting GABAergic interneurons of the mammalian cerebral cortex are a highly heterogeneous population, whose malfunction or deficit has been implicated in a wide range of neurological disorders. However, the low incidence of the various distinct interneuron populations within the neocortex, combined with the lack of molecular or physiological markers specific to these subtypes, have hampered investigations into their function in the normal and dysfunctional brain. A number of research groups have begun to elucidate the developmental genetic mechanism that underpins this diversity in the mouse neocortex, spurred on by the knowledge that the temporal and spatial origin of an interneuron in the embryonic brain is predictive of its eventual intrinsic properties in the mature cortex. In this review we highlight a number of recent findings that strengthen our understanding of the transcription factor code that is at the heart of generating this diversity. Further understanding of this code will enable selective observation, targeting and manipulation of interneuron subtypes across both in vitro and in vivo systems.


Assuntos
Interneurônios/fisiologia , Neocórtex/citologia , Ácido gama-Aminobutírico/metabolismo , Animais , Mapeamento Encefálico , Interneurônios/citologia , Camundongos , Medula Espinal/citologia
20.
Sci Rep ; 11(1): 9801, 2021 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-33963239

RESUMO

Prolactinomas represent the most common type of secretory pituitary neoplasms, with a therapeutic management that varies considerably based on tumour size and degree of hyperprolactinemia. The aim of the current study was to evaluate the relationship between serum prolactin (PRL) concentrations and prolactinoma size, and to determine a cut-off PRL value that could differentiate micro- from macro-prolactinomas. A retrospective cohort study of 114 patients diagnosed with prolactinomas between 2007 and 2017 was conducted. All patients underwent gadolinium enhanced pituitary MRI and receiver operating characteristic (ROC) analyses were performed. 51.8% of patients in this study were men, with a mean age at the time of diagnosis of 42.32 ± 15.04 years. 48.2% of the total cohort were found to have microadenomas. Baseline serum PRL concentrations were strongly correlated to tumour dimension (r = 0.750, p = 0.001). When performing the ROC curve analysis, the area under the curve was 0.976, indicating an excellent accuracy of the diagnostic method. For a value of 204 µg/L (4338 mU/L), sensitivity and specificity were calculated at 0.932 and 0.891, respectively. When a cut off value of 204 µg/L (4338 mU/L) was used, specificity was 93.2%, and sensitivity 89.1%, acceptable to reliably differentiate between micro- and macro- adenomas.


Assuntos
Imageamento por Ressonância Magnética , Proteínas de Neoplasias/sangue , Neoplasias Hipofisárias/sangue , Prolactina/sangue , Prolactinoma , Adulto , Feminino , Gadolínio/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Hipofisárias/diagnóstico por imagem , Prolactinoma/sangue , Prolactinoma/diagnóstico por imagem , Estudos Retrospectivos
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