Lanthanide-Dependent Methanol and Formaldehyde Oxidation inMethylobacterium aquaticumStrain 22A

Lanthanides (Ln) are an essential cofactor for XoxF-type methanol dehydrogenases (MDHs) in Gram-negative methylotrophs. The Ln(3+)dependency of XoxF has expanded knowledge and raised new questions in methylotrophy, including the differences in characteristics of XoxF-type MDHs, their regulation, and the methylotrophic metabolism including formaldehyde oxidation. In this study, we genetically identified one set of Ln(3+)- and Ca2+-dependent MDHs (XoxF1 and MxaFI), that are involved in methylotrophy, and an ExaF-type Ln(3+)-dependent ethanol dehydrogenase, among six MDH-like genes inMethylobacterium aquaticumstrain 22A. We also identified the causative mutations in MxbD, a sensor kinase necessary formxaFexpression andxoxF1repression, for suppressive phenotypes inxoxF1mutants defective in methanol growth even in the absence of Ln(3+). Furthermore, we examined the phenotypes of a series of formaldehyde oxidation-pathway mutants (fae1,fae2,mchin the tetrahydromethanopterin (H4MPT) pathway andhgdin the glutathione-dependent formaldehyde dehydrogenase (GSH) pathway). We found that MxaF produces formaldehyde to a toxic level in the absence of the formaldehyde oxidation pathways and that either XoxF1 or ExaF can oxidize formaldehyde to alleviate formaldehyde toxicity in vivo. Furthermore, the GSH pathway has a supportive role for the net formaldehyde oxidation in addition to the H4MPT pathway that has primary importance. Studies on methylotrophy inMethylobacteriumspecies have a long history, and this study provides further insights into genetic and physiological diversity and the differences in methylotrophy within the plant-colonizing methylotrophs

Basal insulin ratio of type 1 diabetes

Aims/Introduction: To investigate the basal insulin requirement in patients with type 1 diabetes who are on multiple daily injections (MDI) and to assess the patient characteristics that affect the percent of total daily basal insulin dose to the total daily insulin dose (%TBD/TDD). Materials and Methods: The subjects of this study were 67 inpatients with type 1 diabetes who were served diabetic meals of 25–30 kcal/kg standard body weight during several weeks of hospitalization. The basal insulin requirement was adjusted to keep the blood glucose level from bedtime to before breakfast within a 30 mg/dL difference. The bolus insulin dose before the meal was adjusted to keep the blood glucose level below 140 and 200 mg/dL before and 2 h after each meal, respectively. The total daily insulin dose (TDD), the percent of total daily basal insulin dose (TBD) to TDD (%TBD/TDD), and clinical characteristics were collected. Results: The median (Q1, Q3) of TDD was 33.0 (26.0, 49.0) units, and the %TBD/TDD was 24.1 ± 9.8%. The %TBD/TDD was positively correlated with the body mass index (BMI) and negatively correlated with the age at the onset and at the examination according to a univariate analysis. However, the %TBD/TDD was dependent on the BMI (β = 0.340, P = 0.004) and the age at examination (β = −0.288, P = 0.012) according to the multiple regression analysis. Conclusions: The average %TBD/TDD in patients with type 1 diabetes on MDI was approximately 24% under inpatient conditions. The basal insulin requirement was dependent on the BMI and the age at examination

A case of isolated ACTH deficiency that required 6 months for the diagnosis from onset

A 53-year-old man noticed anorexia, nausea, and arthralgia of the upper limbs in April, 201X. Since these symptoms persisted, he visited general hospital and clinic and was examined for blood chemistry, ECG, echocardiography and so on. However, he did not get a definitive diagnosis and was followed up with drip infusion of saline. The symptoms did not subside and fatigue and syncope with hypotension developed. Furthermore, he also suffered weight loss of 10 kg in few months and was referred to our hospital for more detailed examinations in October, 201X. Upon the initial examination, all his symptoms matched those of adrenal insufficiency and notable decreases of both plasma ACTH and serum cortisol level were observed. Prompt glucocorticoid supplementation improved his symptoms and the abnormal laboratory data immediately. He was diagnosed adrenal insufficiency due to isolated ACTH deficiency from the results of CRH loading test and insulin tolerance test. Since most of the symptoms and laboratory findings are non-specific, diagnosis of adrenal insufficiency is often delayed. However, adrenal insufficiency could worsen when the patient is under stress (e.g. infection) and often be life-threatening. Glucocorticoid replacement therapy should be initiated as soon as the diagnosis is confirmed. Furthermore, educating patients and his families plays a very important role in the management of chronic adrenal insufficiency, in particular to the prevention of adrenal crisis

FMD and eGFR Slope in Males and Females

Aims: It is known that there are sex differences in vascular endothelial function and the development of chronic kidney diseases; however, it remains unclear whether sex differences influence the association between vascular endothelial function and renal prognosis. Methods: To clarify the relationship between vascular endothelial function and longitudinal eGFR changes in male and female patients with cardiovascular risk factors, we retrospectively evaluated 341 patients (176 males and 165 females) with cardiovascular risk factors in whom vascular function was assessed by flow-mediated dilation (FMD) and brachial-ankle pulse wave velocity (baPWV) and in whom 24-month longitudinal eGFR values were recorded after the vascular function examinations. Associations of values of FMD and baPWV with values of eGFR slope were statistically analyzed. Results: Simple regression analysis showed that the value of FMD was positively associated with eGFR slope in females (p=0.001) and non-smoking males (p=0.033) but not in smoking males. Multiple regression analysis showed that the value of FMD remains a positive contributor for eGFR slope in females (p=0.001) and non-smoking males (p=0.045) but not in smoking males. In contrast, values of baPWV had no significant association with eGFR slope regardless of sex and cigarette smoking. Conclusions: In individuals with cardiovascular risk factors, evaluation of vascular endothelial function enables prediction of renal prognosis in females and non-smoking males

A case of Cushing’s syndrome detected by repeated fragility fractures

A ３８-year-old woman had suffered from an avulsion fracture of the left cuboid bone, a rib fracture, a fatigue fracture of the left second metatarsal bone and a pubic fracture within the last ４ years. She also realized that her face was getting rounded and became aware of edema on extremities. She had repeated fragile fractures before menopause and was referred to our department on suspicion of secondary osteoporosis. The patients showed physical signs of moon face, central obesity, and abdominal violaceous striae. Cushing’s syndrome was suspected, therefore confirmatory studies were performed. Circadian variation of cortisol : serum cortisol１９．３μg／dL（at７：００）, ２１．４μg／dL（at２３：００）, urinary free cortisol :２４７．４μg／２４h, ACTH :２．５pg／mL. Low-dose（１mg） dexamethasone did not suppress cortisol level（１８．９μg/dL）. Based on these findings, we diagnosed as Cushing’s syndrome and glucocorticoid excess seemed to be the cause of secondary osteoporosis. Abdominal CT identified a ２．７ cm tumor in the left adrenal gland, and in-phase T１‐weighted MRI showed decreased signal compared to out-phase, suggesting an adrenocortical adenoma. She underwent laparoscopic left adrenalectomy. Postoperative fasting serum cortisol decreased to２．２ μg/dL, and glucocorticoid replacement therapy was started. It is necessary to find out any secondary causes for premenopausal women with fragility fractures. It is well known that endocrine disorders including Cushing’s syndrome are the most frequent associated diseases in patients with premenopausal osteoporosis. Cushing’s syndrome should be considered as a causative disease in premenopausal women with osteoporosis

Phase angle and extracellular water-to-total body water ratio estimated by bioelectrical impedance analysis are associated with levels of hemoglobin and hematocrit in patients with diabetes

Background: Anemia is one of the common complications of diabetes and is associated with mortality. Phase angle (PhA), ratio of extracellular water to total body water (ECW/TBW) and skeletal muscle mass index (SMI) estimated by bioelectrical impedance analysis (BIA) have been used as prognostic indicators for various chronic diseases and frailty. We aimed to clarify the clinical significance of PhA, ECW/TBW and SMI for anemia in patients with diabetes. Materials and methods: The values of PhA, ECW/TBW and SMI were estimated by a portable BIA device and blood samples were collected in 371 Japanese patients with diabetes. The relationships of PhA, ECW/TBW and SMI with hemoglobin (Hgb) and hematocrit (Hct) were statistically evaluated. Results: In simple linear regression analysis, PhA and SMI were positively correlated with Hgb and Hct levels in total subjects, male subjects and female subjects. In contrast, ECW/TBW was negatively correlated with Hgb and Hct levels regardless of sex. Multivariate regression analysis showed that both PhA and ECW/TBW but not SMI independently contributed to Hgb and Hct levels after adjustment of clinical confounding factors in both males and females. Conclusions: PhA and ECW/TBW but not SMI were associated with levels of Hgb and Hct in patients with diabetes. Therefore, aberrant values of PhA and ECW/TBW suggest a risk of anemia in diabetic patients

Heparin cofactor II reduces albuminuria

Aims/Introduction: Thrombin exerts various pathophysiological functions by activating protease-activated receptors (PARs). Recent data have shown that PARs influence the development of glomerular diseases including diabetic kidney disease (DKD) by regulating inflammation. Heparin cofactor II (HCII) specifically inactivates thrombin; thus, we hypothesized that low plasma HCII activity correlates with DKD development, as represented by albuminuria. Materials and Methods: Plasma HCII activity and spot urine biomarkers, including albumin and liver-type fatty acid-binding protein (L-FABP), were determined as the urine albumin-to-creatinine ratio (uACR) and the urine L-FABP-to-creatinine ratio (uL-FABPCR) in 310 Japanese patients with diabetes mellitus (176 males and 134 females). The relationships between plasma HCII activities and those DKD urine biomarkers were statistically evaluated. In addition, the relationship between plasma HCII activities and annual uACR changes was statistically evaluated for 201/310 patients (115 males and 86 females). Results: The mean plasma HCII activity of all participants was 93.8 ± 17.7%. Multivariate-regression analysis including confounding factors showed that plasma HCII activity independently contributed to the suppression of the uACR and log-transformed uACR values (P = 0.036 and P = 0.006, respectively) but not uL-FABPCR (P = 0.541). In addition, plasma HCII activity significantly and inversely correlated with annual uACR and log-transformed uACR increments after adjusting for confounding factors (P = 0.001 and P = 0.014, respectively). Conclusions: The plasma HCII activity was inversely and specifically associated with glomerular injury in patients with diabetes. The results suggest that HCII can serve as a novel predictive factor for early-stage DKD development, as represented by albuminuria

経皮静脈サンプリングで責任腫瘍を同定した腫瘍性骨軟化症の一例

We report a case of 57-year-old-female with progressive bone pain and proximal dominant muscle weakness. Laboratory test revealed hypophosphatemia with decreased TmP/GFR, high bone-type ALP and elevated levels of FGF23. Radiograph and CT examination revealed multiple fracture with decreased levels of bone mineral density. She also had 2 cm of subcutaneous elastic soft tumor which located on the base of left big toe. Moreover, somatostatin receptor scintigraphy revealed increase uptake in the tumor with high suspicion of the culprit tumor of tumor-induced osteomalacia （TIO）. To verify that the tumor generates FGF23, we performed percutaneous venous blood sampling. The FGF23 level in the left dorsal vein of foot was highest those in other veins. These results strongly suggested that the tumor produced FGF23 and was the culprit tumor for the disorder. The patient underwent resection of the tumor. One day after surgery, the serum FGF23 level in a peripheral vein decreased to less than the measurement sensitivity, while serum phosphate improved to normal range. Two months of following surgery, clinical and biochemical examinations confirmed the successful of operation. Although it is sometimes difficult to detect the culprit tumors in TIO cases, a combination of localization studies may improve diagnostic accuracy of the culprit tumors. Furthermore, percutaneous peripheral venous sampling would be clinically useful for cases who have the responsible tumor located on limbs, hands and feet

Treatment algorithm of ACTH deficiency

Objective : To examine diagnostic performance of corticotropin-releasing hormone (CRH) test combined with baseline dehydroepiandrosterone sulfate (DHEA-S) in patients with a suspect of central adrenal insufficiency. Methods : Patients (n=215) requiring daily or intermittent hydrocortisone replacement, or no replacement were retrospectively checked with their peak cortisol after CRH test and baseline DHEA-S. Results : None of 106 patients with the peak cortisol ≥ 17.5 μg / dL after CRH test required replacement, and all 64 patients with the peak cortisol < 10.0 μg / dL required daily replacement. Among 8 patients with 10.0 μg / dL ≤ the peak cortisol < 17.5 μg / dL and baseline DHEA-S below the reference range, 6 patients required daily replacement and 1 patient was under intermittent replacement. Among 37 patients with 10.0 μg / dL ≤ the peak cortisol < 17.5 μg / dL and baseline DHEA-S within the reference range, 10 and 6 patients were under intermittent and daily replacement, respectively. Conclusions : No patients with the peak cortisol ≥ 17.5 μg / dL required hydrocortisone replacement, and all patients with the peak cortisol below 10.0 μg / dL required daily replacement. Careful clinical evaluation was required to determine requirement for replacement in patients with 10.0 μg / dL ≤ the peak cortisol < 17.5 μg / dL even in combination with baseline DHEA-S

Heparin Cofactor II and NAFLD in T2DM

Aims: Thrombin exerts various pathophysiological functions by activating protease-activated receptors (PARs), and thrombin-induced activation of PARs promotes the development of non-alcoholic fatty liver disease (NAFLD). Since heparin cofactor II (HCII) specifically inactivates thrombin action, we hypothesized that plasma HCII activity correlates with the severity of NAFLD. Methods: A cross-sectional study was conducted. Plasma HCII activity and noninvasive clinical markers of hepatic fibrosis including fibrosis-4 (FIB-4) index, NAFLD fibrosis score (NFS) and aspartate aminotransferase-to-platelet ratio index (APRI) were determined in 305 Japanese patients with type 2 diabetes mellitus (T2DM). The relationships between plasma HCII activity and the clinical markers were statistically evaluated. Results: Multiple regression analysis including confounding factors showed that plasma HCII activity independently contributed to decreases in FIB-4 index (p＜0.001), NFS (p＜0.001) and APRI (p=0.004). In addition, logistic regression analysis for the prevalence of advanced hepatic fibrosis defined by the cutoff points of the clinical scores showed that plasma HCII activity was the sole and common negative factor for prevalence of advanced hepatic fibrosis (FIB-4 index: p=0.002, NFS: p=0.026 and APRI: p=0.012). Conclusions: Plasma HCII activity was inversely associated with clinical hepatic fibrosis indices including FIB-4 index, NFS and APRI and with the prevalence of advanced hepatic fibrosis in patients with T2DM. The results suggest that HCII can serve as a novel biomarker for assessment of hepatic fibrosis of NAFLD in patients with T2DM