Hiroshi Bando

Somatostatin release as measured by in vivo microdialysis: circadian variation and effect of prolonged food deprivation

In vivo microdialysis was used to determine SRIF release from the hypothalamus in unanesthetized male rats over a period of 24 h and in rats deprived of food for 72 h, in relation to changes in plasma GH levels. Before the experiment, a microdialysis probe was inserted into the anterior pituitary gland of the rats with an indwelling right atrial cannula. Dialysates and blood samples were collected serially, after normal feeding or 72-h deprivation of food. Normal rats implanted with the microdialysis probe showed an episodical pattern of GH secretion at intervals of 3 h. SRIF was secreted in a pulsatile fashion in the dark period in a similar manner to the light period. Mean SRIF pulse amplitude and mean SRIF level were significantly increased in the dark period. There was no significant correlation between the SRIF and GH pulses in the light period. SRIF levels in dialysates obtained from fed rats and food-deprived rats showed a pulsatile pattern. Food deprivation resulted in significant increases in mean SRIF level and mean SRIF pulse amplitude. These results suggest that the existence of circadian rhythm in SRIF release and the increase in SRIF release play an important role in suppressing GH secretion during prolonged food deprivation.

Evaluation of serum concentration of parathyroid hormone-related protein and its implication in hypercalcemia in squamous cell carcinoma of the head and neck

Hypercalcemia is a common and serious complication associated with squamous cell carcinoma (SCC) and is considered to be caused by a tumor-derived factor, parathyroid hormone-related protein (PTHrP). However, the correlation between serum levels of calcium and PTHrP and the kinetics of PTHrP in SCC of the head and neck is unknown, because the behavior of the circulating form of PTHrP in patients has not been determined. In the present study, the PTHrP concentrations in serum samples from 54 patients (37 with SCC and 17 with benign tumors) were measured by a recently developed radioimmunoassay directed toward the C-terminal region of PTHrP, and the laboratory data including those calcium levels in corresponding samples were reviewed retrospectively. Results showed hypercalcemia in four patients with advanced cancer and in whom elevation of the serum PTHrP concentration was observed simultaneously. The regression analysis also revealed the linear relationship of the calcium level to the PTHrP concentration, but not to the concentration of phosphorus or creatinine, suggesting that monitoring of serum PTHrP level is useful for prediction of hypercalcemia associated with head and neck cancer.

Measurement of somatostatin release in rat brain by microdialysis

We determined the most suitable conditions for measuring the somatostatin (SRIF) level by brain microdialysis and investigated its release from the hypothalamus. The relative recovery rate of SRIF was 8.4 +/- 0.5% (mean +/- SE) using a polycarbonate (PC) membrane with the push-pull method at a flow rate of 2 microliters/min. Using tubes with an internal diameter of 0.28 mm and lengths of 5, 25, 50 and 100 cm, the relative recovery rates using a PC membrane with the push method were 8.2 +/- 0.5%, 7.3 +/- 0.6%, 6.2 +/- 0.5% and 4.1 +/- 0.6%, respectively. When using tubes with an internal diameter of 0.1 mm and lengths of 5, 25, 50 and 100 cm, the relative recovery rates were 7.3 +/- 0.7%, 5.6 +/- 1.0%, 3.5 +/- 1.1% and 1.4 +/- 0.7%, respectively. The relative recovery rate was 5.2 +/- 0.5% with a polysulfone (PS-F, Fresenius) membrane, 4.5 +/- 0.4% with a PS-H (Hospal) membrane, 2.6 +/- 0.2% with an ethylenevinyl alcohol membrane (EVAL), 5.1 +/- 0.8% with a polyvinyl alcohol (PVA) membrane and 10.4 +/- 0.8% with a PS-K (Kaneka) membrane. With the push method, the extracellular SRIF level in rat pituitary was 42.8 +/- 1.8 pg/ml with a PC membrane, 23.1 +/- 2.9 pg/ml with an EVAL membrane at a flow rate of 2 microliters/min. With the push-pull method, it was 52.7 +/- 5.2 pg/ml using a PC membrane, 33.5 +/- 2.8 pg/ml using a PVA membrane and 54.4 +/- 3.2 pg/ml using a PS-K membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Radioimmunoassay of growth hormone-releasing hormone (GHRH) with a polyclonal antibody against synthetic GHRH(1–29)-Gly4-Cys-NH2: Method and clinical studies

A radioimmunoassay (RIA) for growth hormone-releasing hormone (GHRH) using a polyclonal antibody against synthetic GHRH(1-29)-Gly4-Cys-NH2 has been developed. The antiserum (RBM105) showed full cross-reactivity with GHRH-(1-44)NH2, GHRH-(1-40)OH, GHRH-(1-37)OH and GHRH-(3-44)NH2, and probably recognized the region of Ala4 to Lys12 of GHRH. Since the sensitivity of the GHRH RIA was 1.5 pg/tube, the lowest detectable plasma level was 5 ng/l when an extract of 0.3 ml of plasma per tube was used. On gelfiltration chromatography, the GHRH immunoreactivity of normal plasma was eluted in the same position as synthetic GHRH. The plasma GHRH concentration in healthy subjects was 20.5 +/- 6.5 ng/l (mean +/- SD), and in patients with hypothalamic disorders was 17.4 +/- 2.0 ng/l. In contrast, the plasma GHRH level in hemodialysis-dependent, chronic renal failure (CRF-HD) patients (38.7 +/- 13.1 ng/l) was significantly higher than normal. The acromegalic patients were 24.3 +/- 11.9 ng/l, except for one patient with ectopic GHRH syndrome (990 ng/l): his plasma GHRH level reached 7,100 ng/l during operation, and then decreased logarithmically to 70 ng/l after 6 h. Somatostatin at concentrations of 10 and 1,000 nmol/l significantly suppressed (GHRH release) from primary culture cells of the GHRH-producing tumor from 17.3 +/- 0.92 ng/2 x 10(5) cells to 9.98 +/- 3.61 and 4.32 +/- 1.01 ng/2 x 10(5) cells, respectively after 48 h. These data indicate that this GHRH RIA is useful for determining the plasma GHRH concentration in normal and diseased states and also for in vitro studies of GHRH release.

Investigation of Uric Acid and Cystatin C on Low-Carbohydrate Diet (LCD)

Background: As to nutritional therapy, continuous discussions were observed concerning calorie restriction (CR) and low-carbohydrate diet (LCD). Authors and colleagues have applied LCD for lots of diabetic patients and reported the detail relationship with ketone bodies and Morbus (M) value. Methods: Ninety-three patients with type 2 diabetes mellitus (T2DM) were considered as subjects in the study, among which 51 were male and 52 were female, 58.3±13.2 years old on average, 60 years old in median. Methods were as follows: 1) patients were admitted and provided formular diet, which included CR diet (60% carbohydrates, 1400 kcal/day) on day 1-2, and LCD (12% carbohydrate, 1400 kcal/day) on day 3-14; 2) several biomarkers on fasting were measured on day 2, 4 and 14; 3) daily profile of blood glucose were done on day 2 and day 4. Results: According to the M-value, subjects were classified into 4 groups, which were less than 25, 26-100, 101-250, more than 251, and number was 24, 24, 24, 21, respectively. The average HbA1c in 4 groups were 6.6%, 7.4%, 8.5% and 9.5% respectively. The median M-values decreased from day 2 to 4, which were 10.4 to 9.1, 53.5 to 7.7, 150 to 19.1 and 438 to 87, respectively. The average uric acid in each group revealed significant increase from day 2 to day 14. There were significant correlation between uric acid increment and creatinine increment, and among creatinine, creatinine clearance (CCr) and Cystatin C. Conclusion: LCD showed efficacy for glucose variability with significant decrease in glucose and M-value. Renal study showed increase of serum uric acid. In addition to correlations of Cystatin C and biomarkers, current results would be from some dehydrated state and/or relative decrease of total calorie intake. These findings would become the fundamental data of efficacy of LCD and its physiological influences for renal function.

Effect of Low Carbohydrate Diet on Type 2 Diabetic Patients and Usefulness of M-Value

Background: Debate between the Calorie Restriction (CR) and Low-Carbohydrate Diet (LCD) has been continued for several years. We have started LCD therapy for diabetic patients since 1999, and experienced good response to control hyperglycemia. Recently the risk of postprandial hyperglycemia for cardiovascular events is reported, and the range of glucose level is focused. Morbus (M) value is proposed to be a good index to show the range of glucose fluctuation. Usefulness of LCD and usefulness of M-value were shown by combined analysis. Methods: Twenty-six patients with Type 2 Diabetes Mellitus (T2DM), who admitted to the Takao Hospital, were the subjects. They were 12 males and 14 females, and their age ranged from 38 to 78 years old. A few patients were new patients, but mostly referred from other hospitals to receive LCD treatment. All patients started from CR therapy with 60% carbohydrate for 2 days, and then carried out LCD dietary therapy with 12% carbohydrates for 10-12 days. On day 2 and 12, blood glucose level was measured at 7 points a day to see the fluctuation from morning to night. Blood and urinary samples were corrected on the same day to get ordinary biochemical data and metabolic marker. Results: To know the effect of LCD on different level of HbA1c, the patients were grouped to low (L; 6.1±0.5%), middle (M; 7.9±0.4%) and high (H; 9.2±0.7%) by HbA1c value. The M-values after 2 day CR were 26.1 (L), 94.1 (M) and 343 (H), respectively. The LCD therapy decreased M-value to 10.4 (L), 18.8 (M) and 84.2 (H), respectively. The significant reduction of M-values was a reflection of the improved postprandial glucose level. LCD was effective even in the bad controlled diabetic patients. In addition to the decreased triacylglycerol and 24 hr urinary C-peptide, uric acid increased in all patients. Conclusion: Ten to 12 day-dietary therapy with LCD was quite effective to improve blood glucose profile. Patients with high HbA1c could be safely treated by LCD. Blood glucose improvement was well correlated to the M-value.

Clinical Effect of Low Carbohydrate Diet (LCD): Case Report

Background: The discussion concerning calorie restriction (CR) and low carbohydrate diet (LCD) has been continued for long yeas. As to LCD, we have reported lots of experience and research for glucose variability and ketone bodies. Subjects and methods: Three cases with type 2 diabetes mellitus (T2DM) were on LCD and studied. Methods included 3 patterns of LCD meal which are super, standard and petit LCD, with including carbohydrate ratio 12%, 26% and 40%, respectively. Case 1 (61, M) showed hyperglycemia about 150 mg/dL to 300 mg/dL in daily profile with 12.5% in HbA1c. Starting super LCD therapy, the glucose profile decreased to less than 150 mg/dL and HbA1c decreased to 6.7% in 3 months. Case 2 (53, M) revealed HbA1c 8.3%, weight 110 kg and body mass index 34.5. By super LCD, his weight was decreased 17 kg in 5 months, with normalized HbA1c and elevated serum 3-hydroxybutyric acid (3-OHBA). Case 3 (72, M) had always extremely elevated fasting triglyceride for 5 years. Starting petit LCD for 2 years, triglyceride and weight were decreased moderately. Successively, changing to standard LCD for 1 year, weight was decreased 6 kg, and triglyceride was normalized. Discussion and conclusion: Each case suggests the characteristic beneficial effect of LCD. From our clinical experience and research, super LCD method, which is one of the very low-carbohydrate ketogenic diet (VLCKD), has evident efficacy of weight reduction. Super-LCD is characterized by strictly limitation for carbohydrate. Standard-LCD and petit-LCD method can be useful and applicable in response to the status of the patients. Thus, LCD treatment have beneficial effects for patients with various status.

Development and pharmacist-mediated use of tools for monitoring atypical antipsychotic-induced side effects related to blood glucose levels

Drug side effects often lead to serious outcomes. Administration of second‐generation antipsychotics has resulted in diabetic ketoacidosis and diabetic coma leading to death. Therefore, pharmacists are required to collect information on clinical test values, determine the appropriate test timing, and coordinate with doctors for further clinical laboratory orders, all of which are labor‐intensive and time‐intensive tasks. In this study, we developed a side effect‐monitoring tool and aimed to clarify the influence and efficiency of monitoring side effects by using the tool in patients taking atypical antipsychotics in whom it is necessary to check clinical test values such as blood sugar levels.

Homeostasis Model Assessment (HOMA) and M Value in Daily Profile of Glucose

Background: Low Carbohydrate Diet (LCD) and Calorie Restriction (CR) have been on discussion for years. Authors have continued diabetic research about LCD, CR, Morbus (M) value and insulin secretion. In this study, homeostasis model assessment (HOMA) was investigated. Subjects and Methods: Subjects enrolled were 52 patients with type 2 diabetes mellitus (T2DM) (average 62.3 years). Methods included the measurement of fasting glucose and immunoreactive insulin (IRI), daily profile of blood glucose and M value. Results:The obtained data were as follows: average HbA1c 8.0%, average glucose of daily profile 222mg/dL. Median data were M value 151, HOMA-R 1.07, HOMA-β 11.1. Divided into 4 groups due to M value, the levels of HOMA-R and HOMA-β in each group were 0.68, 1.08, 1.64, 1.38 and 16.9, 16.3, 10.2, 5.3, respectively. Significant correlation were observed between M value and HOMA-R (p<0.01), and between M value and HOMA-β (p<0.01). Discussion and Conclusion: As M value increases, HOMA-R increases and HOMA-β decreases. These findings suggested that diabetic patients would have insulin resistance and decreased β cell function correlated to the severity of diabetes, and that obtained results would become the basal data in this field, expecting the further development in the future research.

Biology of Human Aging and Recent Nutrition Therapy

Discussion concerning Calorie Restriction (CR) and low carbohydrate diet (LCD) has continued for years. Authors have developed research of LCD using super LCD with 12% of carbohydrate. The biology of human aging includes study between human and mammalian such as mice, rhesus monkeys. Moderate CR reduced age-related mortality, incidence of diabetes, cancer, cardiovascular disease. By very low calorie diet (VLCD), body weight can be reduced, but the diabetic pathological state remains. Besides CR and LCD, Zone, Ornish, LEARN Diets and Mediterranean style can be applicable. There are very low-carbohydrate ketogenic diet (VLCKD), Moderate-LCD, High- Carbohydrate Diet, as related with the definition of LCD. Morbus (M) value was investigated for clinical practice of LCD, in which M value was remarkably improved by LCD treatment.