Total Synthesis of O-GalNAcylated Antifreeze Glycoprotein using the Switchable Reactivity of Peptidyl-N-pivaloylguanidine.

Antifreeze glycoprotein (AFGP) is an O-glycoprotein that displays antifreeze activity through depression of the freezing point of water. GalNAc is a core sugar structure of AFGP, and contributes to induce antifreeze activity of this glycoprotein. However, the general functional role that this sugar plays at the molecular level is still unknown. To elucidate this, it is essential to determine the relationship between structure and activity of O-GalNAcylated AFGP using homogeneous glycoproteins. Thus, the total synthesis of homogeneous O-GalNAcylated AFGP was conducted by using a unique peptide derivative: peptidyl-N-pivaloylguanidine. It was found that peptidyl-N-pivaloylguanidine is an "unreactive" peptide in peptide coupling reactions but is interconvertible with a "reactive" peptide-α-thioester by means of a simple treatment under buffer condition at pH=7 to 8. The unique switchable reactivity of peptidyl-N-pivaloylguanidine enabled an efficient sequential peptide coupling strategy. By using this strategy, various lengths of homogeneous O-GalNAcylated AFGP were synthesized, including one that was 120 amino acids in length, with 40 O-GalNAcylation sites. The structural analysis by circular dichroism spectroscopy and evaluation of the antifreeze activity of the synthetic AFGP(GalNAc)s revealed that the simple O-glycosylation with GalNAc is essential for both structural and functional basis of AFGP to exhibit antifreeze activity.

Chemical modification of biogenous iron oxide to create an excellent enzyme scaffold.

The biogenous iron oxide (BIO) from Leptothrix ochracea was transformed to an organic-inorganic hybrid support to prepare an excellent immobilized enzyme showing high catalytic performance.

Coexistence of aldosterone-producing adrenocortical adenoma and pheochromocytoma in an ipsilateral adrenal gland.

A 40-year-old female, diagnosed as essential hypertension, demonstrated a 2 cm mass in left adrenal gland by computed tomography without abnormal endocrinological findings. (131)I-adosterol and (123)I-metaiodobenzylguanidine (MIBG) scintigraphy at 39 years of age showed no abnormal accumulation. Follow up (131)I-adosterol scintigraphy performed one year later showed apparently abnormal uptake and slightly elevated uptake in left adrenal gland. Her physical examination was unremarkable except for mild hypertension. Routine blood chemistry was normal except for hypokalemia. Endocrinological date revealed suppressed plasma renin activity, and elevated plasma aldosterone concentration, and noradrenalin levels. Serial T2-weighted magnetic resonance imaging clearly demonstrated two distinct tumors. Furthermore, selective adrenal venous sampling with intravenous ACTH infusion indicated aldosterone-producing adrenocortical adenoma (APA) in left adrenal gland. During operation of adrenal tumor, blood pressure elevated markedly and complication of pheochromocytoma (PC) was suspected. Immunohistochemical findings after left adrenolectomy revealed that the adrenal mass was compatible with APA and PC. Risk of operation against undiagnosed PC is very high and, therefore, it must be diagnosed before surgery. Herein, we present an extremely rare case of the simultaneous occurrence of both APA and PC in an ipsilateral adrenal gland.

A case of prolactin deficiency with familial puerperal alactogenesis accompanying impaired ACTH secretion.

We report here the case of a 34-year-old female with puerperal alactogenesis. Her menstrual cycle was regular and breast development normal. She had delivered a healthy boy but could not breast-feed after parturition. Endocrinological studies disclosed that the cause was a prolactin (PRL) deficiency. In addition, she showed accompanying impaired ACTH secretion that was believed to be triggered by encephalitis, although her plasma levels of GH, TSH, LH and FSH remained intact. Pituitary MRI showed no specific findings and anti-pituitary antibody tests were negative. Interestingly, both her mother and grandmother also reported puerperal alactogenesis. The sequences of all five exons of the PRL gene, including promoter region and transcription initiation point, were surveyed in order to examine for certain genetic disorders, but no mutations were identified. Although it cannot be definitively concluded that this PRL deficiency was not a genomic DNA disorder, in our case at least, her PRL gene was normal and, therefore, was not directly responsible for the patient's impaired PRL secretion. This evidence suggests that familial puerperal alactogenesis and PRL deficiency can be induced by other causes such as via disorders of unknown transcription factors or molecules that contribute to translation of PRL gene.

A case of ganglioneuroma in which 131I-6beta-iodomethyl-19-norcholest-5(10)-en-3beta-ol scintigraphy showed high uptake in the adrenal gland leading to a misdiagnosis.

We experienced a case in which 131I-6beta-iodomethyl-19-norcholest-5(10)-en-3beta-ol (131I-adosterol) scintigraphy showed high uptake in the right adrenal gland. We diagnosed functional cortical adenoma because of the finding of 131I-adosterol scintigraphy. However, no positive findings for the existence of cortical adenoma were obtained in other examinations and we performed right adrenalectomy. Unexpectedly, pathological finding showed the right adrenal gland was occupied with a large ganglioneuroma. This is an instructive case in which 131I-adosterol scintigraphy showed abnormal high uptake in the adrenal gland, in spite of the fact that the adrenal gland was occupied by a tumor derived from adrenal medulla.

Effects of platelet release products on neutrophilic phagocytosis and complement receptors.

INTRODUCTION: Platelets enhance leukocytic phagocytosis via the action of ATP and ADP in platelet release products (PRPr). The present study was designed to clarify the type of complements and complement receptors that are involved in phagocytosis activation by PRPr, ATP and ADP. MATERIALS AND METHODS: Human peripheral blood was used as the source of neutrophils and platelets. The supernatant of the platelet suspension after simulation was used as PRPr. The effects of PRPr, ATP, ADP, and other substances on neutrophilic phagocytosis, rosette formation and expression of several antigens were investigated. For the markers of neutrophilic phagocytosis and rosette formation, IgM-sensitized sheep red blood cells (SRBC) were treated with diluted human serum (EAC) or purified complements (C1, C4, C2 and C3) (EAC3b) followed by C3 inactivation (EAC3bi). The expressions of CD11b, CD11c, CD18, and CD35 were evaluated using a flow cytometer. RESULTS: Neutrophilic phagocytosis of EAC and EAC3bi was enhanced by PRPr, ATP, and ADP, whereas this phagocytosis activation was abolished by antibodies against CD11b and CD18. Neutrophil rosette formation with EAC3bi was increased by ATP and ADP. Flow cytometry revealed that the expressions of CD11b and CD35 on neutrophils were increased by PRPr, but not by ATP and ADP. The component in PRPr, responsible for the increase in expressions of these antigens, could not be identified. CONCLUSION: PRPr increases the neutrophilic phagocytosis of complement-coated particles through the action of ATP and ADP by increasing the binding avidity with iC3b, but not the number of Mac-1 (CD11b/CD18).