Serum glycated albumin: Potential use as an index of glycemic control in diabetic dogs.

Measurements of serum fructosamine, glycated hemoglobin, and glycated albumin (GA) complement serum glucose concentration for better management of diabetes mellitus (DM). Especially, the serum fructosamine test has long been used for diagnosing and monitoring the effect of treatment of DM in dogs. However, fructosamine tests are currently not performed in veterinary medicine in Japan. GA and fructoasmine levels have been shown to strongly correlate. However, the clinical implications of using GA remain to be elucidated. Therefore, the purpose of the current study was threefold: 1) Determine whether GA% is altered by acute hyperglycemia in normal dogs, simulating stress induced hyperglycemia; 2) Demonstrate that GA% does not dynamically change with diurnal variation of blood glucose concentration in diabetic dogs; and 3) Investigate whether GA% is capable of providing an index of glycemic control for 1-3 weeks in diabetic dogs as is the case with diabetic human patients. Our study demonstrated that serum GA% remains very stable and unaltered under acute hyperglycemic conditions (intravenous glucose injection) and in spite of diurnal variation of blood glucose concentration. Furthermore, serum GA% can reflect long-term changes (almost 1-3 weeks) in blood glucose concentration and the effect of injected insulin in diabetic dogs.

[A case of recurrent breast cancer successfully treated with docetaxel].

A 50-year-old female underwent mastectomy for left breast cancer in June, 1991. She received tamoxifen for 36 months and tegafur for 30 months as adjuvant therapy. In November 1997, liver, lung and para-aortic lymph node recurrences were found, and we treated her six times with docetaxel 60 mg. After the chemotherapy, a complete response (CR) of all metastatic lesions was achieved and her serum CA15-3 level was decreased. Adverse reactions were grade 4 neutropenia, grade 2 alopecia, fever, and grade 1 edema. She received medroxyprogesterone acetate after the chemotherapy and has been well without re-growth of any metastases for over eight months.

The effect of glucose on growth hormone (GH)-releasing hormone-mediated GH secretion in man.

The effect of glucose on GH-releasing hormone (GHRH)-mediated GH secretion was examined in six normal young men. In two paired experiments, the six men drank a 75-g glucose solution or an equal volume of water 30 min before receiving, iv, 100 micrograms of the 44-amino acid form of human pancreatic GHRH (hGHRH-44). One week later, the same men underwent an identical experimental protocol in a cross-over trial. Basal plasma GH concentrations before hGHRH-44 administration were not statistically different in the two experiments [glucose experiment, 2.1 +/- 0.1 (+/- SE) ng/ml; water experiment, 2.6 +/- 0.6 ng/ml]. The mean peak plasma GH level occurred 30 min after hGHRH-44 administration in both experiments. However, the mean GH response was significantly diminished when the men received glucose (8.12 +/- 1.12 ng/ml) compared to that when they received only water (23.70 +/- 8.46 ng/ml; P less than 0.01). Thus, hyperglycemia may exert an inhibitory effect on the plasma GH response to hGHRH-44.

The effect of free fatty acids on growth hormone (GH)-releasing hormone-mediated GH secretion in man.

The effect of FFA on GH-releasing hormone (GHRH)-mediated secretion of GH was examined in six normal young men. Three of the men were infused with 250 ml of a lipid-heparin solution at 1.67 ml/min for 150 min, and the other three were given an equivalent volume of saline in the same manner. Thirty minutes after the start of infusion, 100 micrograms GHRH (the 44-amino acid form) were injected iv, and plasma GH and FFA were measured. One week later, the same men participated in an identical experiment, but the ones who had received lipid-heparin previously were given saline and vice versa. In both experiments, plasma FFA increased to 2.25 +/- 0.16 meq/liter (mean +/- SEM) 60 min after the start of lipid-heparin infusion, whereas FFA levels did not change significantly in the saline-treated group. Mean plasma GH levels reached peak concentrations in both groups 30 min after GHRH treatment. However, the peak GH response when lipid-heparin was given was significantly diminished (8.4 +/- 1.7 ng/ml), compared with the peak response when saline was given (28.9 +/- 7.1 ng/ml). These data suggest that plasma FFA elevations induced by lipid-heparin infusion inhibit GH secretion induced by GHRH.

Distribution of growth hormone-releasing hormone-like immunoreactivity in human tissue extracts.

A specific RIA for human pancreatic tumor GH-releasing hormone [hpGRH(1-44)NH2] was developed using an antiserum which recognizes the region (Met27-Leu44)NH2 of hpGRH(1-44)NH2. This RIA was used to measure GH-releasing hormone-like immunoreactivity (GRH-LI) in various human tissue extracts. The highest concentration of GRH-LI was detected in extract of pituitary stalk with moderate amounts found in hypothalamus and optic chiasm but none in the cerebrum, cerebellum, medulla oblongata, spinal cord, and anterior pituitary. In peripheral organs appreciable quantities of GRH-LI were found in the pancreas, whereas extracts of thyroid, lung, stomach, duodenum, ileum, colon, adrenal, and kidney contained very low concentrations of GRH-LI. No GRH-LI was detected in liver and spleen extracts. Gel permeation chromatographic analysis of the tissue extract from the hypothalamus revealed only one peak which eluted at the same position as that of 125I-hpGRH(1-44)NH2. Similar analysis of an extract from the optic chiasm showed one peak at the same position as that of 125I-hpGRH(1-44)NH2 and another peak which eluted after hpGRH(1-44)NH2. In contrast, an extract from the pancreas contained only one peak which eluted before 125I-hpGRH(1-44)NH2, indicating a possible precursor form of hpGRH(1-44)NH2. Limited trypsin digestion of the GRH-LI material from the pancreas, followed by gel permeation chromatographic analysis, yielded a major peak eluting at the same position as that of 125I-hpGRH(1-44)NH2. These results suggest that the GRH-LI detected in the hypothalamus most likely corresponds to hpGRH(1-44)NH2 in structure and that the GRH biosynthesized in the hypothalamus is transported to the stalk median eminence and stored there for release into the portal vessels.

Corticotropin-releasing factor test in normal subjects and patients with hypothalamic-pituitary-adrenal disorders.

Corticotropin-releasing factor (CRF) tests were performed in normal subjects and patients with hypothalamic-pituitary-adrenal disorders. In normal subjects, after iv administration of 500 micrograms synthetic ovine CRF, plasma ACTH rose significantly to approximately 3.6 times the basal level at 30-60 min and cortisol reached a peak of 2.3 times the basal level at 60-90 min, whereas aldosterone peaked at 1.6 times the basal level at 60 min. Injection of 100 micrograms CRF in normal subjects also caused a significant increase in plasma ACTH and cortisol levels but only a slight increase in aldosterone. However, the total hormone released and their peak levels were lower than those elicited by the 500-microgram dosage. In patients with Cushing's disease, although the basal and peak levels of plasma ACTH and cortisol induced by administration of CRF were variable, the ratios of increase for the two hormones elicited by CRF were lower than those in normal subjects, especially for cortisol. In patients with Cushing's syndrome due to an adrenal adenoma, basal levels of ACTH were markedly suppressed and plasma ACTH and cortisol did not rise after CRF. In patients with isolated ACTH deficiency or Sheehan's syndrome the basal level of plasma ACTH was less than 5 pg/ml and no change in plasma ACTH occurred after injection of CRF. In patients with Nelson's syndrome or Addison's disease the basal levels of ACTH were extremely elevated but infusion of CRF increased plasma ACTH to even higher levels.

Pituitary adenomas that caused Cushing's disease or Nelson's syndrome are not responsive to ovine corticotropin-releasing factor in vitro.

The response of pituitary adenomas obtained surgically from patients with Cushing's disease of Nelson's syndrome to synthetic ovine corticotropin-releasing factor (CRF), vasopressins, somatostatin-28, dexamethasone, 3-isobutylmethylxanthine or high [K+] was examined in vitro by measuring the amount of pro-opiomelanocortin (POMC)-derived peptides secreted into the culture medium. CRF did not stimulate the secretion of adrenocorticotropin-, beta-endorphin-, or gamma 3-melanotropin-like peptides from the pituitary adenomas at concentrations ranging from 1 x 10(-13) M to 1 x 10(-7) M whereas vasopressins, 3-isobutyrl-methylxanthine and high [K+] increased, while somatostatin-28 and dexamethasone suppressed, the secretion of these POMC-derived peptides. These findings suggest that either the pituitary ACTH-producing tumors have lost their receptors to CRF or their post-receptor mechanism to CRF is not functional.