Narayanan Kandasamy

A Comprehensive Study of Clinical, Biochemical, Radiological, Vascular, Cardiac, and Sleep Parameters in an Unselected Cohort of Patients With Acromegaly Undergoing Presurgical Somatostatin Receptor Ligand Therapy

CONTEXT Attainment of safe GH and IGF-1 levels is a central goal of acromegaly management. OBJECTIVE The aim of this study was to determine the extent to which reductions in GH and IGF-1 concentrations correlate with amelioration of radiological, metabolic, vascular, cardiac, and respiratory sequelae in a single unselected patient cohort. STUDY DESIGN This was a prospective, within-subject comparison in 30 patients with newly diagnosed acromegaly (15 women and 15 men: mean age, 54.3 years; range, 23-78 years) before and after 24 weeks of lanreotide Autogel (ATG) therapy. RESULTS Reductions in GH and IGF-1 concentrations and tumor volume were observed in all but 2 patients (median changes [Δ]: GH, -6.88 μg/L [interquartile range -16.78 to -3.32, P = .000001]; IGF-1, -1.95 × upper limit of normal [-3.06 to -1.12, P = .000002]; and pituitary tumor volume, -256 mm(3) [-558 to -72.5, P = .0002]). However, apnea/hypopnea index scores showed highly variable responses (P = .11), which were independent of ΔGH or ΔIGF-1, but moderately correlated with Δweight (R(2) = 0.42, P = .0001). Although systolic (P = .33) and diastolic (P = .76) blood pressure were unchanged, improvements in arterial stiffness (aortic pulse wave velocity, -0.4 m/s [-1.2 to +0.2, P = .046]) and endothelial function (flow mediated dilatation, +1.73% [-0.32 to +6.19, P = .0013]) were observed. Left ventricular mass index regressed in men (-11.8 g/cm(2) [-26.6 to -1.75], P = .019) but not in women (P = .98). Vascular and cardiac changes were independent of ΔGH or ΔIGF-1 and also showed considerable interindividual variation. Metabolic parameters were largely unchanged. CONCLUSIONS Presurgical ATG therapy lowers GH and IGF-1 concentrations, induces tumor shrinkage, and ameliorates/reverses cardiac, vascular, and sleep complications in many patients with acromegaly. However, responses vary considerably between individuals, and attainment of biochemical control cannot be assumed to equate to universal complication control.

Life-threatening metabolic alkalosis in Pendred syndrome

Introduction Pendred syndrome, a combination of sensorineural deafness, impaired organification of iodide in the thyroid and goitre, results from biallelic defects in pendrin (encoded by SLC26A4), which transports chloride and iodide in the inner ear and thyroid respectively. Recently, pendrin has also been identified in the kidneys, where it is found in the apical plasma membrane of non-α-type intercalated cells of the cortical collecting duct. Here, it functions as a chloride–bicarbonate exchanger, capable of secreting bicarbonate into the urine. Despite this function, patients with Pendred syndrome have not been reported to develop any significant acid–base disturbances, except a single previous reported case of metabolic alkalosis in the context of Pendred syndrome in a child started on a diuretic. Case report We describe a 46-year-old female with sensorineural deafness and hypothyroidism, who presented with severe hypokalaemic metabolic alkalosis during inter-current illnesses on two occasions, and who was found to be homozygous for a loss-of-function mutation (V138F) in SLC26A4. Her acid–base status and electrolytes were unremarkable when she was well. Conclusion This case illustrates that, although pendrin is not usually required to maintain acid–base homeostasis under ambient condition, loss of renal bicarbonate excretion by pendrin during a metabolic alkalotic challenge may contribute to life-threatening acid–base disturbances in patients with Pendred syndrome.

A novel mass spectrometry-based method for determining insulin-like growth factor 1: assessment in a cohort of subjects with newly diagnosed acromegaly

To develop an alternative method to immunoassay for the quantitative analysis of insulin‐like growth factor 1 (IGF‐1) using a mass spectrometry (MS)‐based approach.

Interoceptive Ability Predicts Survival on a London Trading Floor

Interoception is the sensing of physiological signals originating inside the body, such as hunger, pain and heart rate. People with greater sensitivity to interoceptive signals, as measured by, for example, tests of heart beat detection, perform better in laboratory studies of risky decision-making. However, there has been little field work to determine if interoceptive sensitivity contributes to success in real-world, high-stakes risk taking. Here, we report on a study in which we quantified heartbeat detection skills in a group of financial traders working on a London trading floor. We found that traders are better able to perceive their own heartbeats than matched controls from the non-trading population. Moreover, the interoceptive ability of traders predicted their relative profitability, and strikingly, how long they survived in the financial markets. Our results suggest that signals from the body - the gut feelings of financial lore - contribute to success in the markets.

Familial adrenocortical carcinoma in association with Lynch syndrome

Context: Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with a poor prognosis. Although the majority of childhood ACC arises in the context of inherited cancer susceptibility syndromes, it remains less clear whether a hereditary tumor predisposition exists for the development of ACC in adults. Here, we report the first occurrence of familial ACC in a kindred with Lynch syndrome resulting from a pathogenic germline MSH2 mutation. Case: A 54-year-old female with a history of ovarian and colorectal malignancy was found to have an ACC. A detailed family history revealed her mother had died of ACC and her sister had previously been diagnosed with endometrial and colorectal cancers. A unifying diagnosis of Lynch syndrome was considered, and immunohistochemical analyses demonstrated loss of MSH2 and MSH6 expression in both AACs (proband and her mother) and in the endometrial carcinoma of her sister. Subsequent genetic screening confirmed the presence of a germline MSH2 mutation (resulting in deletions of exons 1–3) in the proband and her sister. Conclusion: Our findings provide strong support for the recent proposal that ACC should be considered a Lynch syndrome-associated tumor and included in the Amsterdam II clinical diagnostic criteria. We also suggest that screening for ACC should be considered in cancer surveillance strategies directed at individuals with germline mutations in DNA mismatch repair genes.

Spontaneous cerebrospinal fluid rhinorrhoea as the presenting feature of an invasive macroprolactinoma.

A 29-year-old male university student, with no prior history of trauma, presented with a 1 year history of clear fluid leaking intermittently from his left nostril. His past medical history included bilateral gynaecomastia since age 12, and recent low libido. &bgr;2-transferrin analysis of the nasal fluid confirmed a diagnosis of cerebrospinal fluid (CSF) rhinorrhoea. The serum prolactin was grossly elevated at 42 700 mU/l and brain magnetic resonance imaging (MRI) revealed a large parasellar/sellar mass. A diagnosis of invasive macroprolactinoma complicated by spontaneous CSF rhinorrhoea was made. The patient was commenced on treatment with cabergoline, but while awaiting surgery to repair the CSF leak he developed streptococcus mitis and sanguis meningitis. He made an uncomplicated recovery with antibiotic treatment. Immediately following this episode, the CSF rhinorrhoea resolved spontaneously. Subsequently, a repeat MRI scan revealed dramatic involution of the pituitary mass and the serum prolactin had fallen to 604 mU/l.

Successful treatment of residual pituitary adenoma in persistent acromegaly following localisation by 11C-methionine PET co-registered with MRI

OBJECTIVE To determine if functional imaging using 11C-methionine positron emission tomography co-registered with 3D gradient echo MRI (Met-PET/MRI), can identify sites of residual active tumour in treated acromegaly, and discriminate these from post-treatment change, to allow further targeted treatment. DESIGN/METHODS Twenty-six patients with persistent acromegaly after previous treatment, in whom MRI appearances were considered indeterminate, were referred to our centre for further evaluation over a 4.5-year period. Met-PET/MRI was performed in each case, and findings were used to decide regarding adjunctive therapy. Four patients with clinical and biochemical remission after transsphenoidal surgery (TSS), but in whom residual tumour was suspected on post-operative MRI, were also studied. RESULTS Met-PET/MRI demonstrated tracer uptake only within the normal gland in the four patients who had achieved complete remission after primary surgery. In contrast, in 26 patients with active acromegaly, Met-PET/MRI localised sites of abnormal tracer uptake in all but one case. Based on these findings, fourteen subjects underwent endoscopic TSS, leading to a marked improvement in (n = 7), or complete resolution of (n = 7), residual acromegaly. One patient received stereotactic radiosurgery and two patients with cavernous sinus invasion were treated with image-guided fractionated radiotherapy, with good disease control. Three subjects await further intervention. Five patients chose to receive adjunctive medical therapy. Only one patient developed additional pituitary deficits after Met-PET/MRI-guided TSS. CONCLUSIONS In patients with persistent acromegaly after primary therapy, Met-PET/MRI can help identify the site(s) of residual pituitary adenoma when MRI appearances are inconclusive and direct further targeted intervention (surgery or radiotherapy).

Hypopituitarism, pulmonary infiltration and a spontaneously resolving occipital mass

A 34-year-old man presented with a 12-month history of progressive tiredness and weight loss. Further questioning elicited symptoms of polyuria, polydipsia, reduced libido and erectile dysfunction. He had a 20-pack-a-year smoking history. Physical examination was notable for sparse androgenic hair, loss of muscle bulk and 15 ml testes bilaterally. Biochemical profiling excluded diabetes mellitus, but confirmed partial anterior and posterior hypopituitarism [LH 0.2 U/l (RR 1.5–9.3), FSH 0.9 U/l (RR 1.4–8.1), testosterone 1.1 nmol/l (RR 7.4–25.7), FT4 5.9 pmol/l (RR 5.0–19.6), TSH 2.25 mU/l (RR 0.49–3.95), post-Synacthen® cortisol 463 nmol/l (RR > 550), water deprivation test urine osmolalities: baseline 132 mOsm/kg; 8 hr 147 mOsm/kg; post-desmopressin (2 mcg) 616 mOsm/kg]. Magnetic resonance imaging (MRI) of the brain showed infundibular thickening with contrast enhancement (Figure 1A) and absence of the posterior pituitary bright spot, but no other lesions. A screen for inflammatory and infiltrative disorders [ANCA, ANA, immunoglobulins (including IgG4), serum ACE, ESR and CRP] proved unremarkable. Cerebrospinal …

Hypotension, polyuria and a cardiac arrest

In March 2008, a 73-year-old woman was admitted to hospital for further investigation of a 6-week history of worsening dizziness and lethargy, and a 1-week history of nausea, vomiting and reduced appetite. She had a history of breast carcinoma diagnosed in 1991 (T1N0M0), which was treated with wide local excision, local radiotherapy and tamoxifen for 5 years. In August 2002, she was found to have multiple skeletal metastases and received further hormonal treatment and chemotherapy. At the time of admission, she was apyrexial, her pulse was 80 beats per minute sinus rhythm and blood pressure was 90/60 mmHg. Physical examination was otherwise unremarkable aside from evidence of her previous surgery. Blood tests revealed serum sodium 140 mmol/l (135–145), potassium 3.6 mmol/l (3.5–5.0), urea 1.9 mmol/l (2–7.5), creatinine …