The Pituitary Gland: Small But Mighty

Posted on December 31, 2016 by MaryO

The pituitary gland works hard to keep you healthy, doing everything from ensuring proper bone and muscle growth to helping nursing mothers produce milk for their babies. Its functionality is even more remarkable when you consider the gland is the size of a pea.

“The pituitary is commonly referred to as the ‘master’ gland because it does so many important jobs in the body,” says Karen Frankwich, MD, a board-certified endocrinologist at Mission Hospital. “Not only does the pituitary make its own hormones, but it also triggers hormone production in other glands. The pituitary is aided in its job by the hypothalamus. This part of the brain is situated above the pituitary, and sends messages to the gland on when to release or stimulate production of necessary hormones.”

These hormones include:

  • Growth hormone, for healthy bone and muscle mass
  • Thyroid-stimulating hormone, which signals the thyroid to produce its hormones that govern metabolism and the body’s nervous system, among others
  • Follicle-stimulating and luteinizing hormones for healthy reproductive systems (including ovarian egg development in women and sperm formation in men, as well as estrogen and testosterone production)
  • Prolactin, for breast milk production in nursing mothers
  • Adrenocorticotropin (ACTH), which prompts the adrenal glands to produce the stress hormone cortisol. The proper amount of cortisol helps the body adapt to stressful situations by affecting the immune and nervous systems, blood sugar levels, blood pressure and metabolism.
  • Antidiuretic (ADH), which helps the kidneys control urine levels
  • Oxytocin, which can stimulate labor in pregnant women

The work of the pituitary gland can be affected by non-cancerous tumors called adenomas. “These tumors can affect hormone production, so you have too little or too much of a certain hormone,” Dr. Frankwich says. “Larger tumors that are more than 1 centimeter, called macroadenomas, can also put pressure on the area surrounding the gland, which can lead to vision problems and headaches. Because symptoms can vary depending on the hormone that is affected by a tumor, or sometimes there are no symptoms, adenomas can be difficult to pinpoint. General symptoms can include nausea, weight loss or gain, sluggishness or weakness, and changes in menstruation for women and sex drive for men.”

If there’s a suspected tumor, a doctor will usually run tests on a patient’s blood and urine, and possibly order a brain-imaging scan. An endocrinologist can help guide a patient on the best course of treatment, which could consist of surgery, medication, radiation therapy or careful monitoring of the tumor if it hasn’t caused major disruption.

“The pituitary gland is integral to a healthy, well-functioning body in so many ways,” Dr. Frankwich says. “It may not be a major organ you think about much, but it’s important to know how it works, and how it touches on so many aspects of your health.”

Learn more about Mission Hospital. Learn more about Dr. Frankwich.

From http://www.stjhs.org/HealthCalling/2016/December/The-Pituitary-Gland-Small-but-Mighty.aspx

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Pituitary Dysfunction as a Result of Traumatic Brain Injury

Posted on December 21, 2016 by MaryO

A victim of brain injury can experience many consequences and complications as a result of brain damage. Unfortunately, the problems caused by a traumatic brain injury can extend even beyond what most people think of as the standard symptoms of a brain injury, like mood change and cognitive impairment. One issue which can occur is pituitary dysfunction. If the pituitary gland is damaged due to injury to the brain, the consequences can be dramatic as the pituitary gland works together with the hypothalamus to control every hormonal aspect of a person’s body.

Pituitary dysfunction as a result of a brain injury can be difficult to diagnose, as you may not immediately connect your symptoms to the head injury you experienced. If you did suffer injury to the pituitary gland, you need to know about it so you can get proper treatment. If someone else caused your brain injury to occur, you also want to know about your pituitary dysfunction so you can receive compensation for costs and losses associated with this serious health problem.

The pituitary is a small area of the center of your brain that is about the size of the uvula. The pituitary is surrounded and guarded by bone, but it does hang down.  When it becomes damaged as a result of a brain injury, the damage normally occurs as a result of the fact the pituitary was affected by reduced by reduced blood flow. It can also be harmed directly from the trauma, and only a tiny amount of damage can cause profound consequences.

Many of the important hormones that your body needs are controlled by the pituitary working with the hypothalamus. If the pituitary is damaged, the result can include a deficiency of Human Growth Hormone (HGH). This deficiency can affect your heart and can impact bone development.  Thyroid Stimulating Hormone (TSH) can also be affected, which could result in hypothyroidism. Sex hormones (gonodotropin); Adrenocorticotopic hormone; and many other hormones could be impacted as well, causing fertility problems; muscle loss; sexual dysfunction; kidney problems; fatigue; or even death.

Unfortunately, problems with the pituitary gland may not always be visible on MRIs or other imaging tests because the pituitary is so small. Endocrinologists who handle hormone therapy frequently are not familiar with brain injuries, and may not make the connection that your brain injury was the cause of the problem.

If you begin to experience hormonal issues following an accident, you should be certain to get an accurate diagnosis to determine if your brain injury played a role. If it did, those responsible for causing the accident could be responsible for compensating you for the harm you have experienced to your pituitary and to the body systems which malfunction as a result of your new hormonal issues.

Nelson Blair Langer Engle, PLLC

From http://www.nblelaw.com/posts/pituitary-dysfunction-result-of-traumatic-brain-injury

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Into the brain through the nostrils (Sri Lanka)

Posted on December 21, 2016 by MaryO

There is purposeful concentration, while soft and soothing music plays in the background, as different teams of doctors and nurses, scrub up and move around Operating Theatre (OT) C of the Anuradhapura Teaching Hospital.

On the operating table is a pretty middle-aged woman, but something seems unusual with her face – it seems unduly large, with the nose being pronounced.

While Consultant Anaesthetist Dr. Ayesha Abeyratne and her team are preparing the patient for surgery, two Consultants from different specialties are studying the Magnetic Resonance Imaging pictures. They are Consultant Ear, Nose and Throat (ENT) Surgeon, Dr. Daminda Dumingoarachchi who is also a Head and Neck Surgeon and Consultant Neurosurgeon, Dr. Stravinsky Perera. Although not present in the OT that day, Consultant ENT Surgeon Dr. Upul Abeysundara is also very much a part of this pioneering work in Sri Lanka.

It is a Monday morning and we too are in OT clothes and masks privy to viewing an operation not done anywhere else in the state sector, except the Anuradhapura Hospital.

Accessing the patient’s brain through the nostrils is what the ENT and Neuro Teams will do in one of many trailblazing procedures, while the Anaesthetic Team will ensure that her vitals are stable and the able theatre nursing staff will play their part.

Image-guided (navigation-assisted) endoscopic trans-nasal trans-sphenoidal pituitary surgery is what we are about to view being performed in the country only since October this year. For, the 38-year-old patient lying inert on the operating table has a tumour just above her pituitary gland, between the optic nerves and the carotid arteries, making it a difficult operation-site to access. (The pea-size pituitary gland is dubbed the ‘master gland’ as it produces many hormones for the whole body, while also stimulating other glands to produce other hormones.)

Dr. Dumingoarachchi points out that the ENT navigator which the Anuradhapura Hospital was provided with recently, is like the GPS system of the brain which shows this vital organ’s architecture.

Dr. Perera explains that the patient has acromegaly, the abnormal production of growth hormones from the pituitary, causing a large nose and big hands etc. This is while it also causes an abnormal reduction in other hormones, affecting the functioning of the whole body. The enlarged pituitary is also compressing the main artery of the brain. A major issue is that the patient’s vision is being affected and if the tumour is not decompressed, she would go blind.

Dr. Daminda Dumingoarachchi

Matters also seem complicated as the patient had undergone ‘conventional’ brain surgery to remove an earlier tumour in the same area in 2009 in another hospital, but some parts had been left behind because it was complex surgery and the slightest slip of the scalpel could cause serious harm.

We watch in fascination as the surgical teams discuss how the tumour has grown around the right carotid artery making it a challenging procedure and is pressing down (compressing) on the brain.

This pituitary macroadenoma with acute intra-tumoural haemorrhage (bleeding) is “big” — 5X3.8X3.5cms, says Dr. Perera, adding that laterally, the lesion extends to the right cavernous sinus encircling almost the full circumference of the cavernous part of the right carotid artery. The left carotid artery is spared.

Super-imposing the patient’s Computed Tomography (CT) scan with images of the real anatomy, the ‘registration’ takes place for this ‘re-do’ surgery, as he explains that the anatomy is distorted after her previous surgery done seven years ago.

In the freezing OT, we don’t feel the time passing as both the Neurosurgeon and the ENT Surgeon attend to their tasks, two pairs of hands working in tandem, not looking down at the patient but up at the two screens, while navigating the pathways through the nostrils to the brain.

Usually, such a large tumour above the pituitary gland will entail open-skull surgery, with the brain having to be retracted (drawn away from the site of the operation) to gain access to the tumour, we learn. While the dangers of such surgery are numerous, the patient also has to spend a long time in the Intensive Care Unit (ICU) in the recovery phase.

With the frontiers of medicine pushed back more and more, Dr. Dumingoarachchi says that now skull-base structures can be approached through the nose, ear and throat. “Such surgery involves dealing with pathologies located on the under-surface of the brain, with Neurosurgeons and ENT Surgeons together accessing the skull-base more easily through the nose, ear and throat.”

Pointing out that these trans-nasal and trans-labyrinthine approaches to the skull-base will help bring down the rate of revision neurosurgeries and cut down the time that the patient will have to spend in the ICU post-operatively, he adds that the patients can go back home sooner without complications and be productive more quickly. Currently, some patients even go to other countries to get these services.

With the Health Ministry providing a high definition 3-chip endoscopic camera system, an anterior skull-base set, a micro-debrider and an ENT navigator, vast strides have been made at the Anuradhapura Hospital. They include:

Dr. Stravinsky Perera

* Anterior skull-base surgeries — Endoscopic anterior skull-base surgeries, starting with pituitary surgeries using the endoscopic trans-sphenoidal approach for the first time in Sri Lanka. The latest addition, in October this year, is image-guidance (navigation).

The other procedures include cranio-pharyngioma, olfactory neuroblastoma, cerebrospinal fluid leak repairs, para-nasal sinus cancer resections and odontoid (cervical spine) decompression.

The advantages of this approach include a better field of view and ease of doing revision surgery if required, while leaving no external scars.

Nasal polyposis is also now being managed by image-guided powered full house functional endoscopic sinus surgeries, resulting in the reduction of the recurrence rate. This also cuts down revision surgeries.

*  Lateral skull-base surgeries – Through microscopic lateral skull-base surgery, trans-labyrinthine acoustic neuromas have been removed. With direct access to these eighth-nerve tumours, no brain retraction has been necessitated, resulting in less post-operative morbidity. The whole tumour can be removed while preserving the seventh cranial nerve, as the hospital has also been given intra-operative cranial nerve monitoring facilities.

Paying tribute to Dr. Palitha Mahipala, Director-General of Health Services, for making the navigator available to them, Dr. Dumingoarachchi also expresses appreciation to the Deputy Director-General (DDG) of the Biomedical Division, Muditha Jayathilake, Biomedical Engineers Apsara and Kumuduni and DDG Dr. Lakshmi Somatunga for all their support.

From http://www.sundaytimes.lk/161218/news/into-the-brain-through-the-nostrils-221019.html

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Bilateral testicular tumors resulting in recurrent Cushing’s syndrome after bilateral adrenalectomy

Posted on December 21, 2016 by MaryO
Troy Puar1,2, Manon Engels3,4, Antonius E. van Herwaarden4, Fred C. G. J. Sweep4, Christina Hulsbergen-van de Kaa5, Karin Kamphuis-van Ulzen6, Vasileios Chortis7,8, Wiebke Arlt7,8, Nike Stikkelbroeck1, Hedi L Claahsen–van der Grinten3, Ad R.M.M. Hermus1
Corresponding author: Troy Puar, MRCP (UK), Department of Medicine, Div. of Endocrinology, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands. Phone: +31 243614599, Fax: +31 243618809, e-mail: Troy_puar@cgh.com.sg
DOI: http://dx.doi.org/10.1210/jc.2016-2702
Received: July 14, 2016
Accepted: November 29, 2016
First Published Online: November 30, 2016
Abstract
Context:

Recurrence of hypercortisolism in patients after bilateral adrenalectomy for Cushing’s disease is extremely rare.

Patient:

We present a rare case of a 27-year-old man who previously underwent bilateral adrenalectomy for Cushing’s disease with complete clinical resolution. Cushingoid features recurred 12 years later, along with bilateral testicular enlargement. Hormonal tests confirmed ACTH-dependent Cushing’s. Surgical resection of the testicular tumors led to clinical and biochemical remission.

Design and Results:
Gene expression analysis of the tumor tissue by qPCR showed high expression of all key steroidogenic enzymes. Adrenocortical-specific genes were 5.1 x 105 (CYP11B1), 1.8 x 102 (CYP11B2) and 6.3 x 104 (MC2R) times higher than non-steroidogenic fibroblast control. This correlated with urine steroid metabolome profiling showing 2-5 fold increases in the excretion of the metabolites of 11-deoxycortisol, 21-deoxycortisol and total glucocorticoids. Leydig-specific genes were 4.3 x 101 (LHCGR) and 9.3 x 100(HSD17B3) times higher than control and urinary steroid profiling showed 2-fold increased excretion of the major androgen metabolites androsterone and etiocholanolone. These distinctly increased steroid metabolites were suppressed by dexamethasone, but unresponsive to hCG stimulation, supporting the role of ACTH, but not LH, in regulating tumor-specific steroid excess.
Conclusion:

We report bilateral testicular tumors occurring in a patient with recurrent Cushing’s disease 12 years after bilateral adrenalectomy. Using mRNA expression analysis and steroid metabolome profiling, the tumors demonstrated both adrenocortical and gonadal steroidogenic properties, similar to testicular adrenal rest tumors found in patients with congenital adrenal hyperplasia. This suggests the presence of pluripotent cells even in patients without CAH.

Affiliations
  • 1Department of Medicine, Division of Endocrinology, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands.
  • 2Department of Endocrinology, Changi General Hospital, Singapore 529889, Singapore.
  • 3Department of Paediatrics, Division of Endocrinology, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands.
  • 4Department of Laboratory Medicine, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands.
  • 5Department of Pathology, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands.
  • 6Department of Radiology, Radboud University Medical Centre, 6500 HB Nijmegen, The Netherlands.
  • 7Institute of Metabolism and Systems Research, University of Birmingham, Birmingham N15 2TT, United Kingdom.
  • 8Centre for Endocrinology, Diabetes, and Metabolism, Birmingham Health Partners, Birmingham B15 2TH, United Kingdom.

– See more at: http://press.endocrine.org/doi/abs/10.1210/jc.2016-2702#sthash.F4lfWg9j.dpuf

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Cushing’s Syndrome mutant PKAL205R exhibits altered substrate specificity

Posted on December 15, 2016 by MaryO

Joshua M Lubner, Kimberly L Dodge-Kafka, Cathrine R Carlson, George M Church, Michael F Chou, Daniel Schwartz
doi: https://doi.org/10.1101/091231
This article is a preprint and has not been peer-reviewed.

 

Abstract

The PKAL205R hotspot mutation has been implicated in Cushing’s Syndrome through hyperactive gain-of-function PKA signaling, however its influence on substrate specificity has not been investigated.

Here, we employ the Proteomic Peptide Library (ProPeL) approach to create high-resolution models for PKAWT and PKAL205R substrate specificity. We reveal that the L205R mutation reduces canonical hydrophobic preference at the substrate P+1 position, and increases acidic preference in downstream positions. Using these models, we designed peptide substrates that exhibit altered selectivity for specific PKA variants, and demonstrate the feasibility of selective PKAL205R loss-of-function signaling.

Through these results, we suggest that substrate rewiring may contribute to Cushing’s Syndrome disease etiology, and introduce a powerful new paradigm for investigating mutation-induced kinase substrate rewiring in human disease.

Full PDF at http://biorxiv.org/content/early/2016/12/05/091231.full.pdf+html

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