Molecular characterization of a flavanone 3-hydroxylase gene from citrus fruit reveals its crucial roles in anthocyanin accumulation.

BACKGROUND: Flavanone 3-hydroxylase (F3H), a key enzyme in the flavonoid biosynthetic pathway, plays an important role in the regulation of flavonols and anthocyanidins accumulation. Citrus fruit is a rich source of flavonoids with varied flavonoid compositions among different varieties. To date, the study on F3H is limited in citrus, and its roles in regulating flavonoid accumulation in citrus fruit are still unclear. RESULTS: In this study, we isolated a CitF3H from three different citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Ponkan mandarin (C. reticulata Blanco) and blood orange 'Moro' (C. sinensis Osbeck). Functional analysis showed that CitF3H encoded a functional flavanone 3-hydroxylase. It catalyzed the hydroxylation of naringenin to yield dihydrokaempferol, which was a precursor of anthocyanins in flavonoid biosynthetic pathway. In the juice sacs, CitF3H was differentially expressed among the three citrus varieties, and its expression level was positively correlated with the accumulation of anthocyanins during the ripening process. In the juice sacs of Satsuma mandarin and Ponkan mandarin the expression of CitF3H kept constant at an extremely low level, and no anthocyanin was accumulated during the ripening process. In contrast, the expression of CitF3H increased rapidly along with the accumulation of anthocyanin in the juice sacs of blood orange 'Moro' during the ripening process. In addition, we found that blue light irradiation was effective to up-regulate the expression of CitF3H and improve anthocyanin accumulation in the juice sacs of blood orange 'Moro' in vitro. CONCLUSION: CitF3H was a key gene regulating anthocyanin accumulation in the juice sacs of citrus fruit. The results presented in this study will contribute to elucidating anthocyanin biosynthesis in citrus fruit, and provide new strategies to improve the nutritional and commercial values of citrus fruit.

Food-dependent Cushing's syndrome due to unilateral adrenocortical adenoma with cortisol secretion without ACTH elevation detected in peripheral blood by the CRH test: a case report.

We report an extremely rare case of a 61-year old woman with food-dependent Cushing's syndrome (FDC) due to unilateral adrenocortical adenoma (UAA) with cortisol (CORT) secretion without ACTH elevation detected in peripheral blood by the CRH test. She was on oral medications for hypertension and depression, and presented weight gain, general fatigue, muscle weakness, and hypokalemia. Despite the fact that the diurnal variation of ACTH was always suppressed, a diurnal variation in CORT was observed, in the form of low levels in the early morning and high levels in the afternoon. An increase in CORT was shown in a 75 g-oral glucose tolerance test (OGTT) and in a mixed meal tolerance test, but no change in CORT levels was seen in intravenous glucose tolerance tests. Elevated CORT levels were observed in response to intravenous injection of CRH, although ACTH levels were always below the measured sensitivity. Laparoscopic left adrenalectomy was performed, which resulted in postoperative improvement in potassium and ACTH levels and disappearance of the CORT secretory response in the OGTT. Clear expression of glucose-dependent insulinotropic polypeptide receptor (GIPR), CRH and CRH receptor 2 (CRHR2) were confirmed in the surgically-resected UAA specimen by molecular and immunohistochemical analyses, suggesting the involvement of not only GIPR, but also CRH and CRHR2 in FDC.

A Rare Case of Painless Destructive Thyroiditis Resulting in Thyroid Storm.

Thyroid storm is a life-threatening clinical condition that is usually triggered by untreated or interrupted treatment of Graves' disease, leading to the sudden onset of severe thyrotoxicosis, which requires an immediate diagnosis and treatment based on diagnostic criteria. Cases of thyroid storm caused by painless/painless subacute thyroiditis are very rare. We herein report an 85-year-old man with features of severe thyrotoxicosis caused by painless/painless subacute thyroiditis who had no uptake of 99mTcO4 and was negative for thyroid-stimulating hormone receptor antibodies. In thyroid storm patients in whom the findings are inconsistent with Graves' disease, careful follow-up and management are necessary, assuming the possibility of painless or painless subacute thyroiditis.

Exogenous gibberellin induced regreening through the regulation of chlorophyll and carotenoid metabolism in Valencia oranges.

In the present study, we studied the effects of gibberellic acid (GA) on chlorophyll and carotenoid metabolites and related gene expression during the regreening process in Valencia orange fruits (Citrus sinensis Osbeck). During the regreening, fruits treated with GA turned green much faster than those of the control. Compared with untreated fruits, chlorophyll accumulation was induced and the content of carotenoids (ß-cryptoxanthin, all-trans-violaxanthin, and 9-cis-violaxanthin) was decreased by the GA treatment. Chlorophyll and carotenoid contents following GA treatment appeared to be highly regulated at the gene transcription level. Correspondingly, the up-regulation of chlorophyll biosynthesis genes (CitGGDR, CitCHL27, CitPORA, and CitCAO) and down-regulation of degradation genes (CitCLH1, CitSGR, CitPPH, CitPAO, and CitRCCR) led to the increase of chlorophyll contents, and the down-regulation of carotenoid biosynthesis genes (CitPSY, CitPDS, CitZDS, CitLCYb2, and CitHYb) led to the decrease of carotenoid contents. These observations indicated that GA acted as a crucial regulator in the regreening process of citrus fruits.

Central pontine myelinolysis during treatment of hyperglycemic hyperosmolar syndrome: a case report.

BACKGROUND: Central pontine myelinolysis (CPM) is a non-inflammatory demyelinating lesion of the pons. CPM and extrapontine demyelination (EPM) are together termed osmotic demyelination syndrome (ODS), a known and serious complication of acute correction of hyponatremia. Conversely, hyperglycemic hyperosmolarity syndrome (HHS) develops in patients with type 2 diabetes who still have some insulin secretory ability due to infection, non-compliance with treatment, drugs, and coexisting diseases, and is often accompanied by ketosis. HHS represents a life-threatening endocrine emergency (mortality rate, 10-50%) associated with marked hyperglycemia and severe dehydration. HHS may develop ODS, and some cases have been associated with hypernatremia. CASE PRESENTATION: The patient was an 87-year-old woman with hyperglycemia, dehydration, malnutrition, and potential thrombus formation during long-term bed rest. HHS was suspected to have developed due to progression of hyperglycemia and dehydration caused by pneumonia. Furthermore, ketoacidosis developed from ketosis and prerenal renal failure associated with circulating hypovolemia shock, which was also associated with disseminated intravascular coagulation. Treatment was started with continuous intravenous injection of fast-acting insulin and low-sodium replacement fluid. In addition, ceftriaxone sodium hydrate, heparin sodium, thrombomodulin α, human serum albumin, and dopamine hydrochloride were administered. Blood glucose, serum sodium, serum osmolality, and general condition (including vital, infection/inflammatory findings, and disseminated intravascular coagulation) improved promptly, but improvements in disturbance of consciousness were poor. Diffusion-weighted imaging of the brain 72 h after starting treatment showed no obvious abnormalities, but high-intensity signals in the midline of the pons became apparent 30 days later, leading to definitive diagnosis of CPM. CONCLUSIONS: Fluctuation of osmotic pressure by treatment from hyperosmolarity due to hyperglycemia and hypernatremia in the presence of risk factors such as malnutrition, severe illness, and metabolic disorders may be a cause of CPM onset. When treating HHS with risk factors, the possibility of progression to ODS needs to be kept in mind.

Growth hormone deficiency with late-onset hypothalamic hypoadrenocorticism associated with respiratory and renal dysfunction: a case report.

BACKGROUND: The prevalence of childhood-onset growth hormone (GH) deficiency (GHD) is estimated to be approximately 1 in 5000 or more, with the cause unknown in most cases (idiopathic isolated GHD). However, additional disorders of secretion of other pituitary hormones reportedly develop over time, with a frequency of 2-94% (median, 16%). Furthermore, median times to development of other anterior pituitary hormone deficiencies have been reported to be 6.4-9.4 years. On the other hand, adult patients affected by childhood-onset GHD reportedly develop impaired ventilation function due to reduced lung volumes and respiratory pressures, probably due to reductions in respiratory muscle strength. In addition, GH is known to play a role in stimulating the glomerular filtration rate (GFR), and the estimated GFR (eGFR) is decreased in patients with GHD. CASE PRESENTATION: This case involved a 65-year-old woman. Her short stature had been identified at around 3 years of age, but no effective treatments had been provided. The patient was mostly amenorrheic, and hair loss became apparent in her late 30s. She developed hyperuricemia, dyslipidemia, and hypertension at 45 years of age. In addition, the patient was diagnosed with hypothyroidism at 50 years of age. At 58 years of age, endocrinological examination showed impaired secretion of thyroid-stimulating hormone, luteinizing hormone/follicle-stimulating hormone, and growth hormone, and magnetic resonance imaging showed an empty sella turcica. However, secretion ability of adrenocorticotropic hormone was retained. At 63 years of age, respiratory function tests confirmed a markedly restricted ventilation disorder (vital capacity, 0.54 L; percentage predicted vital capacity, 26.9%). Renal function had also decreased (eGFR, 25.0 mL/min/1.73 m2). Furthermore, she was diagnosed with hypothalamic secondary hypoadrenocorticism. The patient developed CO2 narcosis at 65 years of age, and noninvasive positive pressure ventilation was started. CONCLUSIONS: The rare case of a 65-year-old woman with childhood-onset GHD with panhypopituitarism, including late-onset secondary hypoadrenocorticism in her 60s, associated with severely impaired respiratory function and renal dysfunction, was reported. In GHD patients with risk factors for progression from isolated GHD to combined pituitary hormone deficiency, such as empty sella turcica, lifelong endocrinological monitoring may be important.