Biomedical subjects

H C Lam

Publications and source records attributed to H C Lam.

At least 37 records · Page 2Linked to original sources

PubMed1993

Tissue contents of endothelin vary according to thyroid hormone status in rat.

Endothelin-1 (ET-1) is a 21-residue peptide isolated from the conditioned medium of cultured porcine endothelial cells and is widely distributed throughout the body, with relatively high levels in the kidney and lung. In this study we examined the influence of thyroid hormone status on immunoreactive endothelin (ir-ET) levels in the plasma, lung, and kidney tissues of rats. Three weeks after surgical removal of the thyroid gland from male rats, the ir-ET levels in the lung and kidney were reduced by 39% and 42%, respectively. Similarly, ir-ET levels were decreased by 46% in the lung and 45% in the kidney of rats rendered hypothyroid by treatment with 0.1% (wt/wt) n-propylthiouracil (PTU) in the drinking water for 30 days. Replacement with daily L-thyroxine (T4) injections (5 micrograms/100 g) prevented this decrease. However, thyrotoxicosis induced by daily L-T4 injections (10 micrograms/100 g) also caused a decrease of the lung ir-ET levels by 49%, but had no significant effect on the renal ir-ET levels. However, the plasma ir-ET levels were similar in each group. Fast protein liquid chromatography study verified the presence of ir-ET-1 in the plasma and tissue extracts. This study demonstrates that thyroid hormone status affects tissue levels of ir-ET differently and that a euthyroid status is required for the maintenance of physiologic concentrations of ir-ET in the lung of male rats.

Animals↗

PubMed1991

Cytokine stimulated endothelin release from endothelial cells.

Endothelin release from bovine endothelial cells of the aorta, pulmonary artery, and retinal microvessels was measured in response to various cytokines. Transforming growth factor beta (0.05-5 ng/ml) was found to be a potent stimulator (3-4 fold increase) of endothelin secretion in all three cell types. Tumour necrosis factor alpha (0.1-10 ng/ml) and interferon gamma (8-800 U/ml) had a small (1.5-2 fold increase) but significant effect on endothelin secretion from endothelial cells of large vessels but not the retinal microvessels. Interleukin-1 beta, Interleukin-6 and interleukin-8 at various doses did not affect endothelin secretion. These effects were observed at various time points from 6-24 hrs and indicate that of the cytokines tested, only transforming growth factor beta has a potent effect on endothelin release from endothelial cells of different organs.

Aorta↗

PubMed1991

Endothelin in human brain and pituitary gland: comparison with rat.

To investigate the physiological roles of endothelin (ET) in the brain and pituitary gland, the presence of immunoreactive (ir) ET and ET receptors was studied by radioimmunoassay and receptor assay in humans and rats. ir-ET concentrations in human brain (6-10 fmol/g of wet weight) were comparable with the levels in the rat brain (5-9 fmol/g of wet weight). Higher concentrations of ir-ET were found in human pituitary glands (147 +/- 30 fmol/g of wet weight, mean +/- SEM) and rat posterior pituitary lobes (88 +/- 26 fmol/g of wet weight). Fast protein liquid chromatography (FPLC) showed that the ir-ET in human hypothalamus and brainstem was mainly ET-1, while the ir-ET in human pituitary was mainly ET-3. FPLC of the whole rat brain extract showed a larger peak in the position of ET-3 and a smaller peak in the position of ET-1. Receptor assay showed that [125I]ET-1 binding sites were present in very large numbers in all five human brain regions and four rat brain regions examined but were much less abundant in the human pituitary. ET mRNA was detected by Northern blot hybridization in human pituitary but not in human hypothalamus. These findings are in accord with the possibility that ET acts as a neurotransmitter, neuromodulator, or neurohormone.

Animals↗

PubMed1991

Immunoreactive endothelin in human plasma, urine, milk, and saliva.

Using a highly sensitive radioimmunoassay, elevated plasma immunoreactive endothelin (ir-ET) levels were found in patients with diabetes mellitus (1.88 +/- 0.12 pmol/L, mean +/- SEM, n = 100), patients undergoing maintenance hemodialysis (4.28 +/- 0.76 pmol/L, n = 14), patients with acute myocardial infarction (3.43 +/- 1.03 pmol/L, n = 6), and patients with subarachnoid hemorrhage (4.92 +/- 0.64 pmol/L, n = 14) (normal controls: 0.54 +/- 0.05 pmol/L, n = 19). ir-ET was also present in urine (2.1 +/- 0.3 pmol/L, n = 12), breast milk (6.8 +/- 1.6 pmol/L, n = 16), and saliva (2.0 +/- 0.2 pmol/L, n = 15) obtained from healthy subjects. Chromatography studies verify the identity of endothelin. Fast protein liquid chromatography (FPLC) showed one peak in the normal plasma extract, three peaks in the plasma extracts from diabetic patients and patients undergoing maintenance hemodialysis, three peaks in the urine extract, four peaks in the milk extract, and five peaks in the saliva extract. When the materials eluting in the void volume on FPLC of urine and saliva extracts were loaded onto a Sephadex G-25 column, the ir-ET was eluted in a higher molecular weight region. Incubation of endothelin-1, endothelin-2, and endothelin-3 in urine for 5 h showed that the total amount of ir-ET decreased to less than 30% of the initial levels, suggesting that endothelins are very unstable in urine.

Adult↗

PubMed1991

Endothelin in human brain and pituitary gland: presence of immunoreactive endothelin, endothelin messenger ribonucleic acid, and endothelin receptors.

The presence of immunoreactive (IR) endothelin, endothelin mRNA, and endothelin receptors in human brain and pituitary gland has been studied by RIA, Northern blot hybridization, and receptor assay. IR endothelin was detected in all five brain regions examined (cerebral cortex, cerebellum, brain stem, basal ganglia, and hypothalamus) (6-10 fmol/g wet wt) and spinal cord (22 +/- 6 fmol/g wet wt, n = 7, mean +/- SEM). Higher concentrations of IR endothelin were found in the pituitary gland (147 +/- 30 fmol/g wet wt). Fast protein liquid chromatographic analysis of the IR endothelin in pituitary gland showed a large IR peak in the position of endothelin-3 and a smaller peak in the position of endothelin-1, whereas IR endothelin in the hypothalamus and brain stem was mainly endothelin-1. Endothelin messenger RNA was detected by Northern blot hybridization in the pituitary but not in hypothalamus. The receptor assay showed that 125I-endothelin-1 binding sites were present in large numbers in all five brain regions but were much less abundant in the pituitary gland. Binding capacity and dissociation constant were 5052 +/- 740 fmol/mg protein and 0.045 +/- 0.007 nM in brain stem and 963 +/- 181 fmol/mg protein and 0.034 +/- 0.009 nM in hypothalamus. In the pituitary gland, there were two classes of binding sites for endothelin with dissociation constants of 0.059 +/- 0.002 nM (binding capacity = 418 +/- 63 fmol/mg protein) and 0.652 +/- 0.103 nM (binding capacity = 1717 +/- 200 fmol/mg protein). Endothelin-1, -2 and -3 were almost equipotent in displacing the binding (IC50 approximately 0.04 nM). These findings are in accord with the possibility that endothelin acts as a neurotransmitter, neuromodulator or neurohormone in man.

Aged↗

PubMed1991

Endothelin-like immunoreactivity in rat models of diabetes mellitus.

The factors associated with high concentrations of circulating plasma immunoreactive endothelin in patients with diabetes mellitus are unknown. Plasma and tissue (lung and kidney) immunoreactive endothelin levels were therefore measured by radioimmunoassay in three animal models of diabetes mellitus: dexamethasone-treated rats (2 mg/kg per day for 12 days), streptozotocin-treated rats (100 mg/kg, 4 days before being killed) and rats treated with both dexamethasone and streptozotocin. Plasma concentrations of immunoreactive endothelin in the dexamethasone-treated rats (3.13 +/- 0.28 pmol/l, mean +/- S.E.M., n = 15) were significantly (P less than 0.005) higher than those in controls (1.33 +/- 0.18 pmol/l, n = 15), while plasma concentrations of immunoreactive endothelin in streptozotocin-treated rats (n = 8) and rats treated with both dexamethasone and streptozotocin (n = 14) were undetectable (less than 0.5 pmol/l). Fast protein liquid chromatographic analysis of the plasma immunoreactive endothelin of dexamethasone-treated rats showed four peaks: one in the void volume, one eluting before endothelin-3, one eluting after endothelin-3 and before endothelin-1 and one eluting in a position identical with that of endothelin-1. Pulmonary concentrations of immunoreactive endothelin in the three groups of rats with diabetes mellitus were lower (P less than 0.005) but no significant change was found in renal immunoreactive endothelin. These findings indicate that short-term dexamethasone treatment increases plasma levels of immunoreactive endothelin while streptozotocin treatment decreases them. Thus, multiple factors may influence plasma concentrations of immunoreactive endothelin in diabetes mellitus.

Animals↗

PubMed1991

A twelve month double-blind randomized study of the efficacy and immunogenicity of human and porcine insulins in non-insulin-dependent diabetics.

This study aims to compare the effectiveness and immunogenicity of semisynthetic human insulin (NOVO) and highly purified (monocomponent) porcine insulin over a 12 month period in 16 non-insulin-dependent diabetic subjects not previously exposed to insulin. Sixteen patients were randomly allocated for treatment with either human (n = 9) or monocomponent porcine (n = 7) insulin in a double-blind trial. Both groups were identical with respect to age, sex and measures of metabolic control. Significant insulin antibody was detected in seven of the nine patients (78%) 3 months after the commencement of human insulin therapy whereas it was detected in all patients (100%) in the group treated with monocomponent porcine insulin as early as 2 months after insulin therapy. Besides the delayed rise of insulin antibodies during the first 3 months of human insulin therapy, it tended to have a lower mean insulin antibody titer, though statistically insignificant, at the end of the study. No adverse reaction to either type of insulins was noted. It is concluded that both semisynthetic human and monocomponent porcine insulin were safe and effective. Although human insulin showed a slightly lower immunogenicity than monocomponent porcine insulin of the same formulation and purities, it was not non-immunogenic. Hence, there is no reason to treat all insulin-requiring diabetic subjects with human insulin except those who have developed insulin allergy or those at risk or with a history of allergy.

Adult↗

PubMed1990

Binding sites of a novel neuropeptide pituitary-adenylate-cyclase-activating polypeptide in the rat brain and lung.

Pituitary-adenylate-cyclase-activating polypeptide (PACAP) is a novel 38-amino-acid neuropeptide isolated from ovine hypothalamic tissues based on its activity of stimulating adenylate cyclase of rat pituitary cells. Binding sites for PACAP were studied in rat tissue membranes using a 27-amino-acid N-terminal derivative of PACAP [PACAP(1-27)] labelled with 125I. Particularly high specific binding sites of 125I-PACAP(1-27) were noted in the hypothalamus, brain stem, cerebellum and lung. Specific binding sites are also present in the pituitary gland, but at a lower concentration, and mainly in the anterior lobe. Very low concentration of 125I-PACAP(1-27)-binding sites were found in the colon, aorta and kidney membranes and no binding sites were detected in the pancreas and testis. Maximal binding of 125I-PACAP(1-27) was observed at pH 7.4. Interaction of 125I-PACAP(1-27) with its binding site was rapid, specific and saturable as well as time, pH and temperature dependent. PACAP(1-27) is more potent than PACAP in displacing the binding of 125I-PACAP(1-27) with brain membranes [concentration that inhibits 50% of the binding (IC50) = 7.45 +/- 1.52 nM and 11.45 +/- 3.65 nM, respectively; mean +/- SEM, n = 4] and lung membranes (IC50 = 4.41 +/- 0.87 nM and 10.68 +/- 3.09 nM, respectively). Vasoactive intestinal peptide displaced the binding of 125I-PACAP(1-27) in lung membrane (IC50 = 16.88 +/- 5.14 nM) but not in brain membranes. The equilibrium binding of 125I-PACAP(1-27) at 4 degrees C was characterized by a single class of binding site for the brain membrane with a dissociation constant (Kd) of 2.46 +/- 0.53 nM and a maximal binding capacity (Bmax) of 8.44 +/- 3.13 pmol/mg protein, but there were two classes of binding site for lung membranes with Kd of 1.02 +/- 0.51 nM and 5.19 +/- 0.99 nM, and Bmax of 2.84 +/- 0.72 pmol/mg protein and 9.13 +/- 1.89 pmol/mg protein, respectively. These findings suggest that subtypes of PACAP-binding sites exist and PACAP may have a physiological role in the hypothalamus/pituitary axis as well as in other regions of the brain and lung.

Amino Acid Sequence↗

PubMed1990

Presence of immunoreactive endothelin in human milk.

Endothelin-like immunoreactivity was detected in human milk at a concentration of 6.8 +/- 1.6 pmol/l (mean +/- SEM; n = 16) using a highly sensitive radioimmunoassay. Gel filtration and fast protein liquid chromatography (FPLC) verified the identity of the endothelin. FPLC revealed 4 peaks, one eluting just after the void volume, and the other three in the positions of endothelin-1, -2, and -3, respectively.

Chromatography, Gel↗

PubMed1990

Elevated plasma endothelin in patients with diabetes mellitus.

Plasma concentrations of endothelin, a vasoconstrictor peptide released from vascular endothelial cells, have been measured by radioimmunoassay in 100 patients with diabetes mellitus and 19 healthy subjects. The plasma immunoreactive-endothelin concentrations were found to be greatly raised in the patients with diabetes (1,880 +/- 120 fmol/l, mean +/- SEM) compared with the healthy subjects (540 +/- 50 fmol/l, p less than 0.005). The elevation of immunoreactive-endothelin could not be explained by secondary changes in blood pressure or renal disease and did not correlate with the presence of diabetic retinopathy, duration of diabetes mellitus, fasting blood glucose or serum fructosamine. Fast protein liquid chromatographic analysis of the diabetic plasma immunoreactive-endothelin showed three forms, one in a very big molecular weight position, one intermediate and one in the position of endothelin-1 itself. No material appeared in the positions of endothelin-2 and 3. Chromatographic analysis of normal plasma showed only the big molecular weight peak while material in the endothelin-1, 2 or 3 positions was below detection. The elevation of endothelin in diabetic patients may be a marker of, and further exacerbate, their vascular disease.

Adult↗

PubMed1990

Endothelin in the gastrointestinal tract. Presence of endothelinlike immunoreactivity, endothelin-1 messenger RNA, endothelin receptors, and pharmacological effect.

The possible production and role of endothelin in the gastrointestinal tract was investigated in rats by radioimmunoassay, Northern-blot hybridization, receptor assay using membrane preparations, and pharmacological study using gut strips. Endothelinlike immunoreactivity was detected in all regions (from stomach to colon) of the rat gastrointestinal tract (13-48 fmol/g wet tissue) including the mucosal layer of the ileum and colon (8.4 +/- 2.0 fmol/g wet tissue and 18.4 +/- 2.1 fmol/g wet tissue, respectively, mean +/- SEM; n = 5). Fast protein liquid chromatographic analysis of the endothelinlike immunoreactivity in jejunum, ileum, colon, and colon mucosa extracts showed peaks in the positions of endothelin-1 and endothelin-3. The presence of endothelin-1 messenger RNA was demonstrated by Northern-blot hybridization in the whole colon and pooled ileal and colonic mucosa, but not in the whole jejunum. Specific binding in the rat gastrointestinal tract was particularly high in the fundus of stomach, jejunum, ileum, and colon. In the ileum, many binding sites were found in the circular and longitudinal muscle layers, but few in the mucosal layer. Endothelin-1 and endothelin-3 caused contraction of rat stomach strips, rat colon, and guinea pig ileum. These findings indicate that endothelin is present in the rat gastrointestinal tract, perhaps produced by both vascular endothelial cells and mucosal epithelial cells, and can cause contraction of gastrointestinal smooth muscle. Thus, endothelin may have a physiological role in the control of gastrointestinal function.

Animals↗

PubMed1990

Endothelin immunoreactivity in mice with gram-negative bacteraemia: relationship to tumour necrosis factor-alpha.

1. To investigate the role of endothelin in Gram-negative bacteraemia and the possible involvement of tumour necrosis factor-alpha in its pathophysiology, we measured plasma and tissue (lung, kidney and spleen) immunoreactive endothelin levels in Gram-negative bacteraemic mice, with and without passive immunization by anti-(tumour necrosis factor-alpha) antibody. 2. Plasma immunoreactive endothelin levels were greatly increased after the Escherichia coli injection. Pretreatment with anti-(tumour necrosis factor-alpha) antibody did not suppress elevated plasma immunoreactive endothelin levels (P greater than 0.1). 3. Lung tissue immunoreactive endothelin levels in mice were increased 16 h after the E. coli injection and were not affected by prior passive immunization with anti-(tumour necrosis factor-alpha) antibody. Immunoreactive endothelin in spleen and kidney was undetectable (less than 34 fmol/g wet weight). 4. Injection of rMu tumour necrosis factor-alpha into mice did not increase plasma immunoreactive endothelin levels. 5. Antibody to endothelin given 30 min after a 90% lethal dose challenge with E. coli did not affect mortality. 6. We conclude that the rise in plasma and tissue endothelin that occurs in Gram-negative bacteraemia is independent of tumour necrosis factor-alpha.

Animals↗

PubMed1990

Comparison of insulin secretion and insulin sensitivity between normal and impaired glucose tolerance subjects with normal fasting plasma glucose.

To examine glucose-stimulated insulin secretion and insulin sensitivity in the normal subjects and patients with impaired glucose tolerance, we performed the oral glucose tolerance test (OGTT) and modified insulin suppression test in 34 non-obese subjects. The plasma glucose and insulin concentrations were measured during fasting and every 30 min up to 120 min following 75 g of oral glucose loading. Ten subjects were classified as impaired glucose tolerance (IGT), and 24 subjects were as having normal glucose tolerance. In addition, the insulin-stimulated glucose uptake was estimated in all subjects by measuring the final 30 min steady-state plasma glucose (SSPG) of a continuous infusion of somatostatin, insulin and glucose for 4 hours (modified insulin suppression test). The mean plasma glucose concentrations of fasting and 60, 90, 120 min during OGTT study were significantly higher in the IGT subjects than in the normals. In addition, the mean incremental glucose areas under the curve during OGTT study were also greater in the IGT subjects than in the normals. The mean serum insulin concentrations were significantly higher at 90 and 120 minutes in the IGT patients than in the normals. During the modified insulin suppression test, the mean SSPG concentrations were significantly higher in the IGT patients than in the normals under the similar steady-state plasma insulin in both groups. There was a good correlation between the incremental insulin areas under the curve (OGTT) and the SSPG in the normal subjects (p less than 0.0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Quantitation of fetal-maternal hemorrhage by flow cytometry. A simple and accurate method.

A simple and objective assay was developed for the detection and quantitation of fetal-maternal hemorrhage with the use of flow cytometry. In vitro prepared control mixtures of 10%, 2%, 1%, 0.5%, 0.25%, 0.125%, and 0.06% D+ RBCs in D- RBCs were tested (8-11) different times by flow cytometry and gave mean % D+ results of 11.10%, 1.90%, 0.92%, 0.45%, 0.24%, 0.11%, and 0.05%. The coefficient of variation of preparing and testing these mixtures ranged from 11.0 to 15.9% for the 10-0.125% mixtures. Thus, flow cytometry was accurate, reproducible, and sensitive. Flow cytometry was compared with Du tests, rosette tests, and acid elution. The Du test was highly variable because it was not sensitive enough to detect a significant bleed (approximately 0.6%) in some cases and too sensitive (necessitating quantitation of an insignificant bleed) in others. The rosette test was too sensitive. Acid elution and flow cytometry results did not always agree; acid elution results were approximately twice as high as flow cytometry. The authors believe flow cytometric detection of D+ red blood cells to be more accurate than the detection of fetal hemoglobin by acid elution techniques, which is known to have poor reproducibility. Postpartum samples from 56 D- women who delivered D+ babies were tested. Fifty-two had fetal bleeds less than 0.3% by acid elution and flow cytometry; all had negative Du test results, but there were two false positive results with the use of the rosette technique. Four had significant bleeds (greater than or equal to 0.6%); in all four cases the flow cytometry results were lower than the acid elution results. The authors were able to quantitate a bleed of fetal RBCs, which were D+ only by the Du test, in a D- mother with the use of flow cytometry, and D+ RBCs in a mother whose RBCs were of the rare DVI mosaic phenotype. This would not have been possible with the use of the standard Du or rosette techniques.

Erythrocyte Count↗

PubMed1989

Cushing's syndrome: analysis of 188 cases.

From January 1962 through April 1988, 188 patients with Cushing's syndrome were hospitalized at the Veterans General Hospital. Iatrogenic Cushing's syndrome was found in 123 (65.4%) of the patients. The other 43 patients (22.9%) had excess secretion of adrenocorticotropin (ACTH) and 22 patients (11.7%) had benign or malignant adrenocortical tumors. The clinical features and the functional reserve of the adrenal glands in those patients with iatrogenic Cushing's syndrome were evaluated. A retrospective analysis of the diagnostic rate of the various endocrine evaluations and the radiological examinations was also carried out. Four approaches were used in the management of Cushing's syndrome: (1) pituitary surgery, (2) pituitary irradiation, (3) adrenal surgery, and (4) drug therapy. Both the clinical and hormonal responses to these four management types were evaluated. The endocrinological, radiological, surgical and pathological experiences of 25 patients with Cushing's disease treated with pituitary surgery are presented. Five patients (20%) had an atypical endocrine pattern (20% false-negative). Twenty-four patients received a pituitary CT scan and 16 patients (66.7%) had positive CT findings. Of these 25 patients, 19 had pathology-proven microadenomas (less than 1cm), one had macroadenoma (greater than 1cm) and 5 had no evidence of adenomatous tissue. Among the 22 patients with adrenal Cushing's syndrome, 4 (18%) were suffering from adrenocortical carcinoma and 18 (82%) with benign adrenal tumors. The incidence of left adrenal adenoma was approximately twice that of right adrenal adenoma. The cure rate of adrenocortical adenoma by surgical treatment with unilateral adrenalectomy was excellent, but for adrenocortical carcinoma was poor.

Adolescent↗

PubMed1989

Primary hyperparathyroidism and coexisting hyperthyroidism--review of the literature.

Concomitance of hyperthyroidism and hyperparathyroidism is rare and only forty-nine well documented cases could be found in the literature. In the present study, only forty-three patients with adequate available clinical and laboratory data are reported. Hypercalcemia was found in all the patients and five of them (12%) had acute hyperparathyroidism. Two patients were also pregnant and had pancreatitis. Hypercalcuria was found in 73% and hypophosphatemia in 55% of the patients. Eleven patients (26%) had renal concretions. Skeletal roentgenograms showed abnormalities in 63% of the patients. Elevated serum level of alkaline phosphatase was present in 64% of the patients. However, there seemed to be no correlation with the severity of the skeletal lesions. Thyrotoxicosis commenced before that of Hyperparathyroidism in twenty-three patients (53%) whereas in the remaining twenty patients it was impossible to determine which disease began first. The etiologies of hyperparathyroidism as well as the differential diagnosis of parathyroid-related and nonparathyroid-related hypercalcemia are discussed. Microscopically, 74% of the patients had a single adenoma; 16% had hyperplasia of one to three parathyroid glands. One patient had an adenoma in combination with hyperplasia of one parathyroid gland, one had an adenoma and three hyperplastic glands, one had adenomas of two parathyroid glands in combination with hyperplasia of one parathyroid gland, and the other one had carcinoma of a parathyroid gland.2+ Finally, if a thyrotoxic patient still has hypercalcemia when becoming euthyroid after antithyroid therapy, coexisting hyperthyroidism should be considered and an operation should be performed as surgical treatment cured both diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma↗

PubMed1989

Immunogenicity of highly purified porcine and human insulins in diabetic patients with high titers of insulin antibody.

Twenty-nine non-insulin-dependent diabetic Chinese subjects previously treated with conventional porcine isophane insulin (NPH) for a period of time, whose titer of serum insulin antibody was greater than 40% were changed to either highly purified pork insulin (Nordisk, Denmark) or human insulin of recombinant DNA origin (Eli Lilly, USA) for 1 year in a double-blind and randomized trial. The human (n = 16) and pork insulin (n = 13) groups were carefully matched for age, sex and measures of metabolic control. In highly purified pork-insulin-treated patients, the glycated hemoglobin and fasting blood sugar values began to fall significantly from a mean of 13.2% to 12.3% (p less than 0.05) and 228 mg/dl to 183 mg/dl (p less than 0.005), respectively, 2 months after the commencement of this study, whereas insulin antibody levels began to fall significantly from a mean of 61.8% to 49.5% (p less than 0.01) 6 months after the start of the study. Also, daily insulin doses increased significantly from a mean of 58 units to 70 units (p less than 0.005) 6 months after the start of the study. In human-insulin-treated patients, there were no significant changes in the glycated hemoglobin values. The fasting blood sugar levels fell significantly (p = 0.0515) at the end of the study period but the insulin antibody levels did not show any significant change during the same study period. Daily insulin dose increased significantly from a mean of 51 units to 57 units (p less than 0.01) 4 months after beginning the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Concurrent hyperthyroidism and hyperparathyroidism: influence of hyperthyroidism on serum magnesium, free calcium and parathyroid hormone.

A patient with concomitant primary hyperparathyroidism and Graves' disease with hyperthyroidism was observed during treatment with carbimazole. His serum free calcium levels was initially elevated (6.3mg/dl, normal 4.5-5.3 mg/dl) whereas his serum magnesium level was depressed (1.6 mg/dl, normal 1.7-2.8 mg/dl), but immunoreactive parathyroid hormone levels were only slightly increased (96 pg/ml, normal less than 86 pg/ml). During therapy with carbimazole, the patient became euthyroid and serum free calcium levels decreased to 6.0 mg/dl whereas serum magnesium levels increased to 2.3 mg/dl, and parathyroid hormone increased to values clearly indicative of hyperparathyroidism (185 pg/ml). A subtotal thyroidectomy and parathyroidectomy corrected both diseases in this case. These observations suggested that hyperthyroidism per se causes a decrease in serum magnesium levels and also potentiates the osteoclastic effects of parathyroid hormone resulting in an exacerbation of hypercalcemia which in turn produced a relative inhibition of hormone secretion by the abnormal parathyroid tissue.

Adult↗