Severe bradycardia at acute medical take - Think about myxoedema coma.

We report two cases of myxoedema coma that presented to the acute medical take with severe bradycardia. These patients were initially misdiagnosed as bradyarrhythmia of primary cardiac origin. They were then diverted to the cardiology service at another district general hospital (DGH) for admissions. Both cases were subsequently diagnosed with myxoedema coma having screened thyroid function tests on arrival at the cardiology unit. Despite being treated for myxoedema coma, both patients unfortunately succumbed to the disease and later died in the hospital. These cases highlight that clinical suspicion and recognition of myxoedema coma remain significant challenges in a developed world despite readily available and highly sensitive thyroid hormone assays.

Raised CK and acute kidney injury following intense exercise in three patients with a history of exercise intolerance due to homozygous mutations in SLC2A9.

Acute rhabdomyolysis (AR) leading to acute kidney injury has many underlying etiologies, however, when the primary trigger is exercise, the most usual underlying cause is either a genetic muscle disorder or unaccustomed intense exercise in a healthy individual. Three adult men presented with a history of exercise intolerance and episodes of acute renal impairment following intense exercise, thought to be due to AR in the case of two, and dehydration in one. The baseline serum CK was mildly raised between attacks in all three patients and acutely raised during attacks in two of the three patients. Following referral to a specialized neuromuscular centre, further investigation identified very low serum urate (<12 umol/L). In all three men, genetic studies confirmed homozygous mutations in SLC2A9, which encodes for facilitated glucose transporter member 9 (GLUT9), a major regulator of urate homeostasis. Hereditary hypouricaemia should be considered in people presenting with acute kidney injury related to intense exercise. Serum urate evaluation is a useful screening test best undertaken after recovery.

Granulosa cell production of anti-Müllerian hormone is increased in polycystic ovaries.

CONTEXT: There has been renewed interest in anti-Müllerian hormone (AMH) because of its role in the ovary. Data on its actions are sparse, but it appears to inhibit follicle growth. Interestingly, serum AMH is two to three times higher in women with polycystic ovary (PCO) syndrome than women with normal ovaries. OBJECTIVE: We examined the production of AMH by cells from a range of follicle sizes from normal ovaries and compared this with production by ovulatory and anovulatory (anov) PCOs. DESIGN: Granulosa cells (GCs) and theca and follicular fluid (ff) were isolated from intact follicles. Cells were cultured for 48 h +/- FSH or LH, and AMH was measured in ff and cell-conditioned media (CM). RESULTS: AMH levels in ff and GC-CM ranged from 42 to 2240 and 0.025 to 1.7 ng/ml, respectively, and were low or undetectable in ff and GC-CM from follicles greater than 9 mm, luteinized cells, and theca and stroma. The mean level of AMH was four times higher in GC-CM from ovulatory PCOs [mean (range) 1.56 (0.025-7)] and 75 times higher from anovPCO [21.4 (17.2-43 ng/ml)] than normal ovaries [0.37 (0.025-1.7)]. Neither LH nor FSH had an effect on AMH production by GCs from normal ovaries, but in cells from PCOs, FSH significantly decreased AMH, and in contrast, LH increased AMH. CONCLUSIONS: The reduction of AMH in follicles greater than 9 mm from normal ovaries appears to be an important requirement for the selection of the dominant follicle. AMH production per GC was 75 times higher in anovPCOs, compared with normal ovaries. This increase in AMH may contribute to failure of follicle growth and ovulation seen in polycystic ovary syndrome.

Hypothesis: the case for quaternary hyperparathyroidism.

We report the case of a young woman with hyperparathyroidism due to a large parathyroid adenoma associated with severe vitamin D deficiency. The case is noteworthy for the size of the parathyroid adenoma and for the young age at presentation, and is more typical of the presentation of hyperparathyroidism seen in developing countries where the prevalence of vitamin D deficiency is high. Vitamin D is known to have a suppressive effect on parathyroid cell proliferation and parathyroid hormone synthesis. Vitamin D deficiency may result in a compensatory increase in the secretion of parathyroid hormone (secondary hyperparathyroidism) which involves hyperplasia of all four parathyroid glands. Secondary hyperparathyroidism can become autonomous and this has been termed tertiary hyperparathyroidism, the underlying pathology of which has been variably described in the literature as adenoma formation or four gland hyperplasia. The pathogenesis of parathyroid adenoma formation in vitamin D deficiency remains unclear. It is possible that a proportion of cases represent the coincidence of primary hyperparathyroidism in patients with vitamin D deficiency. Alternatively, we hypothesise that autonomous four gland hyperplasia or tertiary hyperparathyroidism may progress to adenoma formation and that this should be termed 'quaternary hyperparathyroidism'.