Application of region-specific immunoassay for human chromogranin A: substantial clue for detection and measurement of chromogranin A in human plasma

Robot therapy aids mental health in patients with hematological malignancy during hematopoietic stem cell transplantation in a protective isolation unit

Patients with hematological malignancy experience physical and psychological pain, such as a sense of isolation and confinement due to intensive chemotherapy in a protective isolation unit (PIU). We examined whether the intervention of a robotic puppy, aibo (manufactured by Sony), could improve patients' mental health as an alternative therapy for pet therapy, which is not feasible in PIU. This study included 21 patients undergoing allogeneic hematopoietic stem cell transplantation (HSCT) (n = 16) or autologous HSCT (n = 5). The patients were randomly divided into the aibo and control groups. Psychological effects were regularly assessed by measuring the levels of salivary stress hormone chromogranin A (CgA), serum oxytocin, and serum cortisol and the quick Inventory of Depressive Symptomatology Self-Report (QIDS-SR) scores. The aibo group demonstrated a significant decrease in CgA level, while the control group showed the opposite trend. In addition, changes in serum oxytocin and cortisol levels indicated that aibo helped reduce stress. There was no significant difference in the QIDS-SR scores between the two groups; however, the psychomotor activity in the aibo group improved significantly. These findings suggest that aibo intervention during a stay in a PIU can improve the mental health of patients with hematological malignancies who have undergone HSCT.

Chromogranin A in gastrinomas: Promises and pitfalls

Patients with neuroendocrine tumors are found with increasing frequency. Accordingly, knowledge about relevant tumor markers and assays for diagnosis and control has become essential. Neuroendocrine tumors release one or more granin proteins. Of these, chromogranin A (CgA) has so far become the most widely used general marker. The CgA protein is, however, extensively cleaved and otherwise modified during the biosynthetic processing. In addition, the CgA-processing in individual tumors varies considerably. But only few CgA-assays have taken the processing into account and characterized the assays with respect to precise epitope-specificity. Consequently, we do not know which fragments most CgA-assays measure. It is therefore at present difficult to compare CgA-measurements from tumor patients. Some tumors, however, release - in addition to granins - also a specific hormone that causes a clinical syndrome. This review uses gastrinomas (gastrin-producing tumors) as a starting point for discussion of CgA versus peptide hormone as tumor marker. Data available so far indicate that well-defined assays for gastrin have significantly higher diagnostic sensitivity than CgA measurements in gastrinomas. But the review suggests that CgA-quantitation using processing-independent analysis (PIA) may provide an equally high diagnostic sensitivity and in addition offer a simple possibility for estimation of the tumor-burden.

Changes in salivary physiological stress markers induced by muscle stretching in patients with irritable bowel syndrome

Background

Psychophysiological processing has been reported to play a crucial role in irritable bowel syndrome (IBS) but there has been no report on modulation of the stress marker chromogranin A (CgA) resulting from muscle stretching. We hypothesized that abdominal muscle stretching as a passive operation would have a beneficial effect on a biochemical index of the activity of the sympathetic/adrenomedullary system (salivary CgA) and anxiety.

Methods

Fifteen control and eighteen untreated IBS subjects underwent experimental abdominal muscle stretching for 4 min. Subjects relaxed in a supine position with their knees fully flexed while their pelvic and trunk rotation was passively and slowly moved from 0 degrees of abdominal rotation to about 90 degrees or the point where the subject reported feeling discomfort.

Changes in the Gastrointestinal Symptoms Rating Scale (GSRS), State Trait Anxiety Inventory (STAI), Self-rating Depression Scale (SDS), ordinate scale and salivary CgA levels were compared between controls and IBS subjects before and after stretching. A three-factor analysis of variance (ANOVA) with period (before vs. after) as the within-subject factor and group (IBS vs. Control), and sex (men vs. female) as the between-subject factors was carried out on salivary CgA.

Results

CgA showed significant interactions between period and groups (F[1, 31] = 4.89, p = 0.03), and between groups and sex (F[1, 31] = 4.73, p = 0.03). Interactions between period and sex of CgA secretion were not shown (F[1, 3] = 2.60, p = 0.12). At the baseline, salivary CgA in IBS subjects (36.7 ± 5.9 pmol/mg) was significantly higher than in controls (19.9 ± 5.5 pmol/mg, p < 0.05). After the stretching, salivary CgA significantly decreased in the IBS group (25.5 ± 4.5 pmol/mg), and this value did not differ from that in controls (18.6 ± 3.9 pmol/mg).

Conclusion

Our results suggest the possibility of improving IBS pathophysiology by passive abdominal muscle stretching as indicated by CgA, a biochemical index of the activity of the sympathetic/adrenomedullary system.

Salivary chromogranin-A as a marker of psychological stress during a cognitive test battery in humans

The purpose of the present study was to evaluate the salivary Chromogranin-A (CgA) response to the psychological stress induced by a cognitive test battery. The subjects were 14 healthy volunteers administered the cognitive test battery CogScreen Aeromedical Edition (CogScreen-AE). CogScreen-AE is a test of reaction time and fundamental cognitive ability in the assessment of aeroplane pilots. The subjects were given five batteries of the test (1st approximately 5th) on separate days with 2 week intervals. Saliva samples were collected at 20 min before the test (BASE), immediately before the test (PRE), in the middle of the test (MID), and 5 min after the test (POS) for each subject. The concentration of CgA was determined by enzyme-linked immunosorbent assay. ANOVA revealed a significant by time interaction (BASE, PRE, MID and POS) without a significant effect of battery interaction (1st, 2nd, 3rd, 4th and 5th). The CgA concentration increased at PRE (2.46 +/- 0.24 pmol.mg protein- 1) from BASE (1.19 +/- 0.10 pmol.mg protein- 1). CgA level remained increased in the MID (2.90 +/- 0.26 pmol.mg protein- 1) and remained high in the POS samples (2.81 +/- 0.23 pmol.mg protein- 1). Salivary CgA remained at basal levels during a control study over the same time course without exposure to CogScreen-AE. The changes in salivary CgA secretion as a result of exposure to a cognitive task may indicate psychological stress in humans.

Expression and Localization of Chromogranin A Gene and Protein in Human Submandibular Gland

Human saliva chromogranin A (CgA) is clinically promising as a psychological stress marker. However, expression of CgA is poorly understood in humans, although salivary gland localization of CgA in other mammals, such as rodents and horses, has been demonstrated. In the present study, we investigated the expression and localization of CgA in the human submandibular gland (HSG) using various methods. CgA was consistently localized in serous and ductal cells in HSG, as detected by immunohistochemistry and in situhybridization. Reactivity was stronger in serous cells than in ductal cells. In addition, strong immunoreactivity for CgA was observed in the saliva matrix of ductal cavities. Western blotting gave one significant immunoreactive band of 68 kDa in the adrenal gland, HSG and saliva. Finally, CgA was detected in secretory granules of serous and ductal cells by immunoelectron microscopy. In conclusion, CgA in humans is produced by HSG and secreted into saliva.

Early decline in the catecholamine release-inhibitory peptide catestatin in humans at genetic risk of hypertension

BACKGROUND

Hypertension is a complex trait with an ill-defined genetic predisposition, in which adrenergic mechanisms seem to be involved even at the early stages. Chromogranin A is a pro-hormone stored and released with catecholamines by exocytosis; its fragment catestatin, formed in vivo, inhibits further catecholamine release as an antagonist at the physiologic trigger for secretion, the neuronal nicotinic cholinergic receptor.

METHODS

We measured catestatin by radioimmunoassay in n = 277 subjects stratified by blood pressure (n = 61 hypertensive, n = 216 normotensive), and if normotensive by genetic risk of developing hypertension: family history positive (n = 176) versus negative (n = 40). Maximum likelihood analysis tested for bimodality. Involvement of catestatin in pathophysiology was probed by measurements of catecholamines and leptin, and the hemodynamic responses to environmental (cold) stress.

RESULTS

The normotensive offspring of patients with hypertension already had diminished catestatin (P = 0.024), and family history was a better predictor of catestatin than age, ethnicity or gender (P = 0.014). Greater catestatin variance among family history-positive individuals (P = 0.021) suggested heterogeneity in this group, and a bimodal distribution (P < 0.001) identified 4.3% of individuals in a lower mode of catestatin values, all with positive family histories (P = 0.05). Catestatin correlated inversely with body mass index (r = -0.215, r(2) = 0.046, n = 276, P < 0.001) and plasma leptin (r = -0.203, r(2) = 0.041, n = 212, P = 0.003), while body mass index and leptin correlated directly (r = 0.59, r(2) = 0.350, n = 212, P < 0.001). Family history-positive individuals had greater epinephrine excretion (P = 0.037) in addition to diminished catestatin, suggesting an inhibitory effect of catestatin on chromaffin cells in vivo. Low plasma catestatin predicted enhanced pressor response to a sympathoadrenal stressor (cold stress; r = -0.184, r(2) = 0.034, n = 211, P = 0.007), suggesting an adrenergic mechanism whereby diminished catestatin might predispose to later development of hypertension. In white subjects, diminished catestatin also predicted greater systemic vascular resistance responses to cold stress (r = -0.307, r(2) = 0.094, n = 75, P = 0.007), a relationship not found in Blacks (r = 0.122, r(2) = 0.015, n = 94, P = 0.243).

CONCLUSIONS

We conclude that catestatin is diminished early in the course of development of hypertension, even in the normotensive offspring of patients with the disease. Low catestatin predicts augmented adrenergic pressor responses, suggesting a mechanism whereby diminished catestatin might increase the risk for later development of hypertension.

Immunochemical characterization and measurement of neuronal type nitric oxide synthase in human neuroblastoma NB-OK-1 cell using novel anti-synthetic peptide antibody and specific immunoassay system

We developed a sensitive and specific immunoassay system for human neuronal nitric oxide synthase (hnNOS) using synthetic hnNOS(998-1024) peptide and anti-hnNOS(998-1024) antibody. The novel antibody and radioimmunoassay system revealed a typical nNOS protein in human neuroblastoma NB-OK-1 cell (160 kDa, 180 fmol/10(6) cells). The kinetic parameters of the enzyme were K(m)=4.88 microM and V(max)=4.34 pmol/min/mg protein for L-arginine. On incubation of NB-OK-1 cell for 24 h, betamethasone phosphate decreased both nNOS-immunoreactivity (nNOS-IR) and enzymatic activity in the cell dose-dependently. On the other hand, pituitary adenylate cyclase activating polypeptide(1-38) (PACAP38) increased both nNOS-IR and enzymatic activity at concentrations of 10(-10) and 10(-9) M, but inversely decreased both at 10(-7) M. These suggest the positive and negative implications of endogenous NO in proliferation and differentiation of the cell, which support mitogenic activity of NO generated by nNOS in the cell. The present findings also provided evidence that the quantitative change of nNOS protein controls the integrated activity of the enzyme in the cell and, in turn, substantiate the validity and reliability of the present immunoassay system for hnNOS and its practical usefulness.

Chromogranin A and the alpha-subunit of glycoprotein hormones in medullary thyroid carcinoma and phaeochromocytoma

Using specific immunoradiometric assays, we evaluated the clinical usefulness of chromogranin A and the alpha-subunit of glycoprotein hormones in neuroendocrine tumours of neuroectodermic origin. The serum alpha-subunit of glycoprotein hormones was only slightly increased in 2 out of 44 medullary thyroid carcinoma or phaeochromocytoma patients with increased calcitonin or 24-hour urinary metanephrine levels. Serum chromogranin A was increased in 12 of 45 (27%) medullary thyroid carcinoma patients with an elevated calcitonin level and in 4 of 16 medullary thyroid carcinoma patients (25%) with an undetectable calcitonin level, in 5 of 7 phaeochromocytoma patients with increased urinary catecholamine and metabolite excretion, and in 2 of 3 patients with a non-functioning phaeochromocytoma. During follow-up, the course of chromogranin A was found to parallel that of tumour burden and/or 24-hour urinary metanephrine in 5 phaeochromocytoma patients. We conclude that chromogranin A measurement is not recommended for the diagnosis of medullary thyroid carcinoma patients. It may be useful in patients with functioning and non-functioning phaeochromocytomas as a follow-up marker. In neuroendocrine tumour patients with elevated calcitonin secretion, the serum alpha-subunit of glycoprotein hormone measurement may help differentiate medullary thyroid carcinoma or phaeochromocytoma patients from other endodermal-derived neuroendocrine tumour patients in whom it is frequently elevated.