Pars Intermedia Research Articles

Disfunção da pars intermedia da hipófise em equinos associado a adenoma pituitário

ABSTRACT: The clinical syndrome of the pituitary pars intermedia dysfunction (PPID) is the most common endocrinopathy of older horses. This syndrome is characterized by several clinical and pathological changes, which are usually associated with adenomas of the pars intermedia (PI) of the pituitary gland. The aim of this work is to describe five cases of pituitary adenoma of the PI associated with PPID in horses, addressing its clinical and pathological aspects. The horses had a mean of 22 years of age. The main clinical signs were hirsutism and paresis of hind limbs, and at post mortem examination all horses had hirsutism, and a nodule in the pituitary gland, which was histologically characterized as an adenoma of PI (5/5). Furthermore, two horses had gross lesions suggestive of chronic laminitis. Moreover, there was intense parasitism of Sarcocystis neurona (2/5), Strongylus vulgaris (1/5), Parascaris equorum (1/5), Draschia megastoma (1/5), and Klossiella equi (1/5).

Endoscopic Treatment of Rathke's Cleft Cysts: The Case for Simple Fenestration.

Rathke's cleft cysts (RCC) arise from the pars intermedia because of incomplete regression of the embryologic Rathke pouch. A subset of RCC becomes symptomatic causing headaches, visual and endocrinological disturbances such that surgical intervention is indicated. Several points in surgical management remain controversial including operative strategy (simple fenestration (SF) vs complete cyst wall resection (CWR)) as well as reconstructive techniques. A retrospective analysis was conducted of pathologically confirmed RCC operated on by endoscopic endonasal approach from 2006 to 2019. Pre-operative symptoms, imaging characteristics, operative strategy, symptom response, complications and recurrences were recorded. Thirty-nine patients were identified. Thirty-three underwent SF and six underwent CWR. Worsening pituitary function was significantly increased with CWR (50%) compared to SF (3%) (p = 0.008). All patients underwent "closed" reconstruction with a post-operative CSF leak rate of 5% (3% SF vs 16% CWR, p = 0.287). Six (15%) recurrences necessitating surgery were reported. Recurrence rates stratified by surgical technique (18% SF vs 0% CWR, p = 0.564) were not found to be significantly different. The current series illustrates variability in the surgical management of RCCs. SF with closed reconstruction is a reasonable operative strategy for most symptomatic RCCs cases while CWR can be reserved for selected cases.

Atypical Lesions in Canine Leishmaniosis: Description of New Cases.

Simple SummaryCanine leishmaniosis is a zoonotic disease caused mainly by the protozoan Leishmania infantum that is endemic in the Mediterranean basin. The clinical signs and pathological characteristics have been extensively described; however, atypical lesions leading to clinical and pathological misdiagnosis have been sporadically reported. This study presents three cases of dogs experimentally infected with Leishmania infantum that showed gross lesions considered atypical of canine leishmaniosis and not previously reported. Macroscopic lesions were observed in the liver, spleen, and peritoneal cavity that corresponded to tan to whitish nodular lesions in all organs and multifocal irregular and linear whitish lesions in one of the livers that mimicked tumors. Microscopically, a marked granulomatous inflammation with a relative scarcity of parasites was observed in all the organs. In conclusion, microscopic and parasitological studies should be performed on atypical lesions observed in Leishmania-infected and non-infected dogs, especially in endemic regions. In addition, due to its zoonotic importance, leishmaniosis should be considered when atypical nodular lesions are observed in dogs from non-endemic regions with a history of travel to endemic regions.Pathological characteristics are well described in canine leishmaniosis (CanL). However, atypical lesions that can be confused with other pathologies or trigger unusual clinical signs are sporadically reported. Atypical lesions were observed during routine postmortem examination in three Leishmania-infected dogs and samples were taken for histopathological and immunohistochemical studies. Clinical signs, biochemical parameters, level of antibodies, and parasite detection by PCR were also evaluated. Atypical lesions were found in the peritoneal cavity, liver, and spleen. Splenomegalia and hepatomegalia were observed in all dogs. In addition, multifocal dark to white nodules of variable size were observed in the peritoneal cavity, liver, and spleen of one dog and in the spleen of the other two dogs. One dog presented diffuse irregular whitish lines with a threadlike appearance and another an intense fibrotic depression in the intermediate lobe. Microscopically, an intense granulomatous inflammation with abundant macrophages, a variable number of lymphocytes, and a low to moderate number of parasites was observed. This study represents the first description of granulomatous peritonitis associated with Leishmania in dogs. It also shows atypical macroscopic expression of hepatitis in CanL. In the absence of an adequate clinical history and laboratory analyses, certain lesions observed in CanL could admit alternative diagnoses.

The astroglial and stem cell functions of adult rat folliculostellate cells.

The mammalian pituitary gland is a complex organ consisting of hormone-producing cells, anterior lobe folliculostellate cells (FSCs), posterior lobe pituicytes, vascular pericytes and endothelial cells, and Sox2-expressing stem cells. We present single-cell RNA sequencing and immunohistofluorescence analyses of pituitary cells of adult female rats with a focus on the transcriptomic profiles of nonhormonal cell types. Samples obtained from whole pituitaries and separated anterior and posterior lobe cells contained all expected pituitary resident cell types and lobe-specific vascular cell subpopulations. FSCs and pituicytes expressed S100B, ALDOC, EAAT1, ALDH1A1, and VIM genes and proteins, as well as other astroglial marker genes, some common and some cell type-specific. We also found that the SOX2 gene and protein were expressed in ~15% of pituitary cells, including FSCs, pituicytes, and a fraction of hormone-producing cells, arguing against its stem cell specificity. FSCs comprised two Sox2-expressing subclusters; FS1 contained more cells but lower genetic diversity, while FS2 contained proliferative cells, shared genes with hormone-producing cells, and expressed genes consistent with stem cell niche formation, regulation of cell proliferation and stem cell pluripotency, including the Hippo and Wnt pathways. FS1 cells were randomly distributed in the anterior and intermediate lobes, while FS2 cells were localized exclusively in the marginal zone between the anterior and intermediate lobes. These data indicate the identity of the FSCs as anterior pituitary-specific astroglia, with FS1 cells representing differentiated cells equipped for classical FSC roles and FS2 cells exhibiting additional stem cell-like features.

Correlation of pituitary histomorphometry with dopamine and dopamine D2 receptor expression in horses with pituitary pars intermedia dysfunction

Pituitary pars intermedia dysfunction (PPID) is an endocrinopathy commonly affecting old horses. It is a spontaneously occurring, progressive disease that is still poorly understood. Previous studies have observed neurodegeneration of the dopaminergic inhibition of melanotrophs, which leads to decreased dopamine (DA) in the pars intermedia (PI) and increased pro-opiomelanocortin-derived peptides circulating in plasma. However, rats knockout for the dopamine D2 receptor (D2r) similarly develop PI hypertrophy and hyperplasia. Thus, based on the current pathophysiological theory of PPID, whether the decreased DA or the D2r dysfunction leads to PPID is still unclear. To test this, a total of 28 retrospective cases of horses with PPID were collected, graded and the expression of tyrosine hydroxylase (TH) and D2r in the PI were determined. The histological and immunohistochemical results demonstrated that horses with higher tumor histological grades had reduced TH expression with increased D2r immunoreactivity colocalized in the PI (p < 0.001, p < 0.05 respectively). This correlation supports the role of DA in the pathogenesis of continuous unregulated proliferation of neoplastic cells in PI and indicates the efficiency of D2r agonists as a treatment for PPID.

Reproductive phase related variations in the expression of neuropeptide, cocaine- and amphetamine- regulated transcript (CART) in the brain and pituitary gland of adult male Microhyla ornata

Cocaine- and amphetamine-regulated transcript (CART) peptide is a multifaceted neuropeptide involved in several physiological functions including appetite and reproduction. While studies in mammals, aves and fishes suggest evolutionary conserved role of CART, the information in amphibian is scanty. We have investigated the reproductive phase related variations of CART in the brain of adult male Microhyla ornata. Seasonal changes in the expression of CART peptide were noticed in the brain and pituitary of M. ornata. Significant differences were observed in the nucleus infundibularis ventralis (NIV), epiphysis (E), anteroventral tegmental region (AV), raphe nucleus (Ra) of the brain and pars intermedia (PI), pars distalis (PD) of the pituitary. Compared to the pre-breeding and post-breeding seasons, increase in CART immunoreactivity was seen in E, NIV, AV, Ra of brain and PI, PD of pituitary gland of animals collected during breeding season. Similarly, highest mRNA levels of CART were also observed in the breeding season in the middle region of brain that includes hypothalamus and pituitary gland. Variation in the levels of CART peptide and mRNA in the brain of M. ornata suggests its conserved role in seasonal control of appetite and reproduction.

The multiciliated cells in Rathke's cleft express CYP26A1 and respond to retinoic acid in the pituitary.

The adenohypophysis consists of the anterior and intermediate lobes (AL and IL). The marginal cell layer (MCL), including the ventral region of the IL and the dorsal region of the AL lining the Rathke's cleft, acts as the primary stem/progenitor cell niches in adult adenohypophysis. The cells of the MCL on the IL side consisted of cluster of differentiation 9 (CD9)-positive stem/progenitor cells with or without motile cilia. However, any additional cellular properties of multiciliated CD9-positive cells are not known. The present study aimed to identify the character of the multiciliated cells in stem cell niche of the pituitary gland. We observed the fine structure of the multiciliated cells in the MCL of male Wistar rats at an early stage after birth and in adulthood (P60) using scanning electron microscopy. Since the previous study showed that the MCL cells of adult rats synthesize retinoic acid (RA), the present study determined whether the multiciliated cells are involved in RA regulation by the expression of retinal aldehyde dehydrogenase 1 (RALDH1) and CYP26A1, an enzyme synthesizing and degrading RA, respectively. Results showed that 96% of multiciliated cells in adult male rats expressed CYP26A1, while 60% expressed RALDH1. Furthermore, the isolated CD9-positive cells from the IL side MCL responded to RA and activated the degradation system of RA by increasing Cyp26a1 expression. These findings indicated that multiciliated cells are involved in RA metabolism in the MCL. Our observations provide novel insights regarding the stem cell niche of the adult pituitary.

Differentiation of stem progenitor CD9/SOX2-positive cells is promoted with increased prolactin-producing and endothelial cells in the pituitary

Sex-determining region Y-box 2 (SOX2)-positive cells are stem/progenitor cells in the adenohypophysis, comprising the anterior and intermediate lobes (AL and IL, respectively). The cells are located in the marginal cell layer (MCL) facing Rathke’s cleft (primary niche) and the parenchyma of the AL (secondary niche). We previously demonstrated in vitro that the tetraspanin superfamily CD9 and SOX2 double-positive (CD9/SOX2-positive) cells in the IL-side MCL migrate to the AL side and differentiate into hormone-producing and endothelial cells in the AL parenchyma. Here, we performed in vivo studies to evaluate the role of IL-side CD9/SOX2-positive cells in pregnancy, lactation, and treatment with diethylstilbestrol (DES; an estrogen analog) when an increased population of prolactin (PRL) cells was observed in the AL of the rat pituitary. The proportions of CD9/SOX2-, CD9/Ki67-, and PRL/TUNEL-positive cells decreased in the primary and secondary niches during pregnancy and DES treatment. In contrast, the number of CD9/PRL-positive cells increased in the AL-side MCL and AL parenchyma during pregnancy and during DES treatment. The proportion of PRL/Ki67-positive cells increased in the AL-side MCL and AL parenchyma in response to DES treatment. Next, we isolated CD9-positive cells from the IL-side MCL using an anti-CD9 antibody. During cell culture, the cells formed free-floating three-dimensional clusters (pituispheres). Furthermore, CD9-positive cells in the pituisphere differentiated into PRL cells, and their differentiation potential was promoted by DES. These findings suggest that CD9/SOX2-positive cells in the IL-side MCL may act as adult stem cells in the AL parenchyma that supply PRL cells under the influence of estrogen.

Basal plasma adrenocorticotrophic hormone concentration for diagnosing pituitary pars intermedia dysfunction in horses: Comparative analysis of two systematic reviews

Basal plasma adrenocorticotrophic hormone concentration for diagnosing pituitary pars intermedia dysfunction in horses: Comparative analysis of two systematic reviews

Proximal to distal grain‐size distribution of basin‐floor lobes: A study from the Battfjellet Formation, Central Tertiary Basin, Svalbard

AbstractThe grain‐size distribution of sediment particles is an important aspect of the architecture of submarine fans and lobes. It governs depositional sand quality and reflects distribution of particulate organic carbon and pollutants. Documenting the grain‐size distribution of these deep‐marine sedimentary bodies can also offer us an insight into the flows that deposited them. Submarine lobes are commonly assumed to linearly fine from an apex, meaning there should be a proportional relationship between grain size and distance from the lobe apex. However, not much detailed quantitative work has been done to test this hypothesis. Exposure of a 5 km long dip‐section of basin‐floor lobes in Clinoform 12, Battfjellet Formation, Spitsbergen, enable the study of basinward grain‐size evolution in lobe deposits. Furthermore, the dataset allows testing if there are any documentable grain‐size differences between lobe sub‐environments. For this purpose, the palaeogeography of Clinoform 12 was reconstructed and the youngest lobe, which was exposed in all collected logs, chosen to be evaluated for its grain‐size trends. Photographed thin sections of 66 rock samples were analysed to obtain quantitative grain‐size distributions. The results show that fining of lobe deposits occurs predominantly in the most proximal and most distal parts of the lobe, while the intermediate lobe, which is dominated by lobe off‐axis deposits, is characterised by a relatively consistent grain‐size range. Lobe sub‐environments show statistically distinct grain‐size distributions from lobe axis to lobe fringe. An explanation for these trends is the interplay of capacity and competence‐driven deposition with the grain‐size stratification of the flows. The outcomes of this study help to better understand the proximal to distal evolution of turbidity currents and their depositional patterns. They also provide important insights in reservoir potential of basin‐floor fans at lobe scale.

Equine multinodular pulmonary fibrosis in a Thoroughbred with pituitary pars intermedia dysfunction

Equine multinodular pulmonary fibrosis in a Thoroughbred with pituitary pars intermedia dysfunction

Non-Canonical Effects of ACTH: Insights Into Adrenal Insufficiency.

IntroductionAdrenocorticotropic hormone (ACTH) is produced from proopiomelanocortin, which is predominantly synthetized in the corticotroph and melanotroph cells of the anterior and intermediate lobes of the pituitary gland and the arcuate nucleus of the hypothalamus. Although ACTH clearly has an effect on adrenal homeostasis and maintenance of steroid hormone production, it also has extra-adrenal effects that require further elucidation.MethodsWe comprehensively reviewed English language articles, regardless of whether they reported the presence or absence of adrenal and extra-adrenal ACTH effects.ResultsIn the present review, we provide an overview on the current knowledge on adrenal and extra-adrenal effects of ACTH. In the section on adrenal ACTH effects, we focused on corticosteroid rhythmicity and effects on steroidogenesis, mineralocorticoids and adrenal growth. In the section on extra-adrenal effects, we have analyzed the effects of ACTH on the osteoarticular and reproductive systems, adipocytes, immune system, brain and skin. Finally, we focused on adrenal insufficiency.ConclusionsThe role of ACTH in maintaining the function of the hypothalamic–pituitary–adrenal axis is well known. Conversely, if we broaden our vision and analyze its role as a potential treatment strategy in other conditions, it will be evident in the literature that researchers seem to have abandoned this aspect in studies conducted several years ago. We believe it is worth re-evaluating the role of ACTH considering its noncanonical effects on the adrenal gland itself and on extra-adrenal organs and tissues; however, this would not have been possible without the recent advances in the pertinent technologies.

Anisotropy and inhomogeneity of permeability and fibrous network response in the pars intermedia of the human lateral meniscus

Within the human tibiofemoral joint, meniscus plays a key role due to its peculiar time-dependent mechanical characteristics, inhomogeneous structure and compositional features. To better understand the pathophysiological mechanisms underlying this essential component, it is mandatory to analyze in depth the relationship between its structure and the function it performs in the joint. Accordingly, the aim of this study was to evaluate the behavior of both solid and fluid phases of human meniscus in response to compressive loads, by integrating mechanical assessment and histological analysis. Cubic specimens were harvested from seven knee lateral menisci, specifically from anterior horn, pars intermedia and posterior horn; unconfined compressive tests were then performed according to three main loading directions (i.e., radial, circumferential and vertical). Fibril modulus, matrix modulus and hydraulic permeability of the tissue were thence estimated through a fibril-network-reinforced biphasic model. Tissue porosity and collagen fibers arrangement were assessed through histology for each region and related to the loading directions adopted during mechanical tests. Regional and strain-dependent constitutive parameters were finally proposed for the human lateral meniscus, suggesting an isotropic behavior of both the horns, and a transversely isotropic response of the pars intermedia. Furthermore, the histological findings supported the evidences highlighted by the compressive tests. Indeed, this study provided novel insights concerning the functional behavior of human menisci by integrating mechanical and histological characterizations and thus highlighting the key role of this component in knee contact mechanics and presenting fundamental information that can be used in the development of tissue-engineered substitutes. Statement of significanceThis work presents an integration to the approaches currently used to model the mechanical behavior of the meniscal tissue. This study assessed in detail the regional and directional contributions of both the meniscal solid and fluid phases during compressive response, providing also complementary histological evidence. Within this updated perspective, both knee computational modeling and meniscal tissue engineering can be improved to have an effective impact on the clinical practice.

Intracerebroventricular administration of α-melanocyte-stimulating hormone (α-MSH) enhances thigmotaxis and induces anxiety-like behavior in the goldfish Carassius auratus

α-Melanocyte-stimulating hormone (α-MSH) is a body pigmentation-regulating hormone secreted from the intermediate lobe of the pituitary in vertebrates. It is also produced in the brain, and acts as an anorexigenic neuropeptide involved in feeding regulation. In rodents, intracerebroventricular (ICV) administration of α-MSH has been shown to affect not only feeding behavior, but also psychomotor activity. However, there is still no information regarding the psychophysiological effects of α-MSH on behavior in fish. Therefore, we examined the effect of synthetic α-MSH on psychomotor activity in goldfish. Since this species prefers the edge to the central area of a tank, we used this as a preference test for assessing psychomotor activity. When α-MSH was administered ICV at 1 and 10 pmol g−1 body weight (BW), the time spent in the edge area of a tank was prolonged at 10 pmol g−1 BW. However, α-MSH at these doses did not affect locomotor activity. The action of α-MSH mimicked those of FG-7142 (a central-type benzodiazepine receptor (CBR) inverse agonist with an anxiogenic effect) at 10 pmol g−1 BW and melanotan II (a melanocortin 4 receptor (MC4R) agonist) at 50 pmol g−1 BW, whereas ICV administration of tofisopam (a CBR agonist with an anxiolytic effect) at 10 pmol g−1 BW prolonged the time spent in the central area. The anxiogenic-like effect of α-MSH was abolished by treatment with the MC4R antagonist HS024 at 50 pmol g−1 BW. These data indicate that α-MSH affects psychomotor activity in goldfish, and exerts an anxiogenic-like effect via the MC4R-signaling pathway.

Immunohistochemical description and dispensation of the hypophyseal cell types in Liza ramada

ABSTRACTIntroduction: The localization and characterization of the hypophyseal cell types in L. ramada is so far lacking. Aim of the work: The present study aimed to describe and determine the hypophyseal cells in L. ramada. Material and methods: Immunohistochemical localization of the hormone-secreting cells in the hypophysis of L. ramada was completed by antisera against both mammalian and piscine hormones.Results: The hypophysis of L. ramada was comprised two main parts, the glandular part (adenohypophysis) and the nervous part (neurohypophysis). The adenohypophysis was divided into three subdivisions; rostral pars distalis (RPD), proximal pars distalis (PPD) and pars intermedia (PI). Seven of hormone-secreting cells were distinguished in the glandular part according to their grouping, distribution, and immunoreactivity. The acidophilic prolactin (PRL) cells occupied the bulk of the RPD and showed positive and specific immunoreaction with salmon PRL antiserum. Lead hematoxylin-positive (PbH+) cells, which were bordered the neurohypophysis in the RPD, gave positive immunoreactivity with human adrenocorticotrophic (ACTH) antiserum. The acidophilic cells of the PPD immunoreacted positively and strongly with antiserum against salmon growth hormone (GH). In addition, the central region of PPD comprised basophilic cells which were showed specific and strong immunoreaction with antisera against salmon gonadotropin (GTH) subunits; Iβ and IIβ. The presumptive thyrotropin (TSH) secreting cells were distinguished in the neurohypophysis between the RPD and the PPD, and they were negative immunoreacted with antiserum against rat thyrotropin (rBetaTSH). Two cell types were found in the PI; the Periodic Acid-Schiff-positive (PAS+) cells which had positive immunoreaction with anti-salmon somatolactin (SL) and the Lead hematoxylin-positive (PbH+) cells which immunostained with anti-alpha-melanin-stimulating hormone (α-MSH). Conclusion: The localization of hypophyseal cells of L. ramada, consider as basis for understanding and tracking hormonal changes during its reproductive cycle in captivity.

CD9-positive cells in the intermediate lobe migrate into the anterior lobe to supply endocrine cells.

The adenohypophysis is composed of the anterior and intermediate lobes (AL and IL), and secretes important hormones for growth, sexual development, metabolism, and reproduction. In the marginal cell layer (MCL) facing Rathke's cleft between the IL and AL, cluster of differentiation (CD) 9-, CD81-, S100β-, and SOX2-quadruple positive (CD9/CD81/S100β/SOX2-positive) cells in the adult IL are settled as tissue-resident stem/progenitor cells supplying hormone-producing cells to the AL. However, it is unclear how CD9/CD81/S100β/SOX2-positive cells in the IL-side MCL migrate into the AL across Rathke's cleft. In the present study, we performed chimeric pituitary tissue culture using S100β/GFP-transgenic rats and Wistar rats, and traced the footprint of S100β/GFP-expressing cells. We detected IL-side S100β/GFP-expressing cells in the AL tissue, demonstrating that these cells migrate from the IL to the AL. However, the cells failed to migrate in the opposite direction. Consistently, scanning electron microscopic analysis revealed well-developed cytoplasmic protrusions in the IL-side MCL, but not in the AL-side MCL, suggesting that IL-side CD9/CD81/S100β/SOX2-positive cells had higher migratory activity. We also searched for a specific marker for IL-side CD9/CD81/S100β/SOX2-positive cells and identified tetraspanin 1 (TSPAN1) from microarray analysis. Downregulation of Tspan1 by specific siRNA impaired cell migration and significantly reduced expression of snail family transcriptional repressor 2 (Slug), a marker of epithelial-mesenchymal transition (EMT). Therefore, CD9/CD81/S100β/SOX2-positive cells in the IL-side MCL can be stem/progenitor cells that provide stem/progenitor cells to the AL-side MCL via SLUG-mediated EMT and cell migration.

Constraining the AGN duty cycle in the cool-core cluster MS 0735.6+7421 with LOFAR data

Context.MS 0735.6+7421 is a galaxy cluster that hosts a central radio galaxy with a very steep spectrum. The spectrum is produced by one of the most powerful known jetted active galactic nuclei (AGN). The radio plasma, ejected at nearly light speed from the central AGN, has displaced the intra-cluster medium, leaving two pairs of cavities observable in the X-ray. The cavities are associated with two different outbursts and have distributed energy to the surrounding medium. While the age of the cavities has previously been estimated from the X-rays, no confirmation from radio data is available. Furthermore, the radio spectrum has only been derived from integrated flux density measurements so far, and the spatial distribution that would help us to understand the nature of this source is still lacking.Aims.We perform for the first time a detailed, high-resolution spectral study of the source at radio frequencies and investigate its duty cycle. We compare this with previous X-ray estimates.Methods.We used new observations at 144 MHz produced with the LOw Frequency ARray (LOFAR) together with archival data at higher frequencies (235, 325, 610, 1400, and 8500 MHz), to investigate the spectral properties of the source. We also used radiative models to constrain the age of the source.Results.At the LOFAR frequency, the source presents two large outer radio lobes that are wider than at higher frequencies, and a smaller intermediate lobe that is located south-west of the core. A new inspection of X-ray data allowed us to identify an intermediate cavity that is associated with this lobe. It indicates a further phase of jet activity. The radio lobes have a steep spectrum even at LOFAR frequencies, reachingα144610= 2.9 in the outer lobes andα144610= 2.1 in the intermediate lobe. Fitting the lobe spectra using a single injection model of particle ageing, we derived a total age of the source between 170 and 106 Myr. This age agrees with the buoyancy and sound-crossing timescales derived from X-ray data. The resolution of the spectral age map we performed allows us to reconstruct the duty cycle of the source. In three phases of jet activity, the AGN was active for most of the time with only brief quiescent phases that ensured the repeated heating of the central gas. Finally, we estimated the minimum energy inside the outer lobes. We find that a source of additional pressure support must be present to sustain the bubbles against the pressure of the external medium.

Intraspecific variation of Vanilla planifolia (Orchidaceae) in the Huasteca region, San Luis Potosí, Mexico: morphometry of floral labellum

Vanilla planifolia is an orchid endemic to Mexico. It is important to characterize the morphological variation and to describe the morphological traits of its wild populations to enable use of this natural variation in agroecosystems and breeding programs. The objective of this study was to identify infraspecific morphological variation of V. planifolia in the San Luis Potosi Huasteca region, Mexico, where it is distributed naturally. We dissected 679 flowers from 40 accessions and subjected the labella to morphometric analysis, evaluating 76 morphological traits using an analysis of variance, principal component analysis, and cluster analysis. We found that there is highly significant variation among the accessions. The first three components explained 78% of the accumulated variance among groups. We identified four morphological groups, differentiated by the proximal lobe of the B region and the apical lobe of the F region, as well as the internal angles of the intermediate and lateral lobes of regions D and E. These angles determine labellum shape: rounded, bell-shaped, globular, or rhomboid. Morphotype I is oblanceolate shaped with tiny lobes. Morphotype II is bell-shaped, with long triangular lobes. Morphotype III is globular with large, wide lobes. Morphotype IV is rhomboid with very large lanceolate lobes. Morphological variation exists among V. planifolia specimens, which represent a strategic genetic resource in localities of San Luis Potosi, Mexico.

CD9-positive cells in the intermediate lobe of the pituitary gland are important supplier for prolactin-producing cells in the anterior lobe.

A supply of hormone-producing cells from stem/progenitor cells is critical to sustain the endocrine activity of the pituitary gland. In the adenohypophysis composing the anterior and intermediate lobe (AL and IL, respectively), stem/progenitor cells expressing sex-determining region Y-box 2 (SOX2) and S100β are located in the marginal cell layer (MCL) facing Rathke's cleft (primary niche) and the parenchyma of the AL (secondary niche). Our previous studies using mice and rats indicated that the tetraspanin superfamily CD9 and CD81 are expressed in S100β/SOX2-positive cells of primary and secondary niches (named CD9/CD81/S100β/SOX2-positive cell), and the cells located in the AL-side niches exhibit plasticity and multipotency. However, it is unclear whether CD9/CD81/S100β/SOX2-positive cells in the IL-side primary niche are stem/progenitor cells for the AL or IL. Here, we successfully isolated pure CD9/CD81/S100β/SOX2-positive cells from the IL-side primary niche. They had a higher level of S100β and SOX2 mRNA and a greater pituisphere forming capacity than those of CD9/CD81/S100β/SOX2-positive cells isolated from the AL. They also had capacity to differentiate into all types of adenohypophyseal hormone-producing cells, concomitantly with the loss of CD9 expression. Loss of CD9 and CD81 function in CD9/CD81/S100β/SOX2-positive cells by siRNA treatment impaired prolactin cell differentiation. Consistently, in the pituitary gland of CD9/CD81 double knockout mice, dysgenesis of the MCL and a lower population of prolactin cells were observed. These results suggest that the CD9/CD81/S100β/SOX2-positive cells in the MCL of the IL-side are potential suppliers of adult core stem cells in the AL.

Diverse Manifestation of Acromegaly With Suspicion of Ectopic GHRH Secretion. Report of Two Cases

Introduction: Acromegaly can rarely be caused by an ectopic production of GH or GHRH by various neoplasms, most commonly neuroendocrine tumors of pancreatic or pulmonary origin. Squamous cell carcinoma of the lung has not been associated with ectopic GHRH secretion yet. The authors present two cases of acromegaly with suspicion of GHRH ectopy. Presentation of the Cases: Case 1. A male born in 1945 presenting with typical morphologic features of acromegaly. Pituitary MRI revealed a cuneatic-shaped, hypointense focal lesion (8x7x6 mm) in the right posterior part of the anterior pituitary lobe, radiologically interpreted as either hyperplasia of the intermediate lobe or atypical adenoma in a normal-sized pituitary. IGF-1 and no suppression of GH secretion after oral glucose load were observed. Furthermore, a polycyclic tumor in the 2nd segment of the right lung with pathological metabolic activity in 18FDG- PET/CT was discovered. Ga68- DOTA TATE PET/CT revealed no pathological accumulation of the tracer. After upper right lobectomy, squamous cell carcinoma, non-keratinizing, G3, with a negative immunohistochemical reaction for GH was confirmed. IHC for GHRH and serum GHRH have been scheduled. After surgery and chemotherapy, no biochemical remission of acromegaly was observed and the pituitary MRI showed stable radiological image of the pituitary tumor, suggesting rather a possible metastasis to the pituitary. Due to unfavorable prognosis, the patient was disqualified from neurosurgical resection of the pituitary tumor. Case 2. a male born in 1948 with typical symptoms of acromegaly, elevation of IGF-1 and no suppression of GH in OGTT. Due to MRI contraindications, only CT of the head was performed- it revealed partially empty sella, compressed pituitary with maximal diameter 3 mm and no focal lesions. Treatment with somatostatin analogue was introduced, however, only partial biochemical control was achieved. Ga68- DOTA TATE PET/CT performed after 8 years showed pathological expression of somatostatin receptors in the pancreatic tail. Abdominal CT confirmed a focal lesion in this location, 14x9 mm, with a strong enhancement after contrast administration, suggesting a neuroendocrine tumor. The patient refused to undergo any invasive procedures and remains treated with SRL. Serum GHRH has been scheduled. Conclusion: The authors report two cases of ectopic acromegaly suspicion, with an ambiguous clinical and radiological presentation. In unclear cases of acromegaly, ectopic production of GHRH should be taken into consideration.