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Biomedical subjects

J M Falko

Publications and source records attributed to J M Falko.

At least 55 records · Page 3Linked to original sources

Gastrin Responses to a test meal in patients with familial medullary thyroid carcinoma.

The serum gastrin response to a standard test meal was evaluated in patients with familial medullary thyroid carcinoma (MTC) and in normal subjects. Patients with MTC and elevated plasma calcitonin levels had a lower gastrin response to the test meal than did normal persons or MTC patients who had normal calcitonin levels postthyroidectomy. There was no significant difference between the mean gastrin response of the normal group and that of the MTC patients with normal calcitonin levels. The serum gastrin response was studied before and after thyroidectomy in four patients. In all four, the post-operative response was greater than the preoperative one . We conclude that patients with MTC may have reduced gastrin responses to a test meal. This effect may be related to circulating calcitonin, somatostatin, or other factors related to familial MTC.

Adolescent↗

Effects of nicotinic acid therapy on plasma lipoproteins and very low density lipoprotein apoprotein C subspecies in hyperlipoproteinemia.

The effects of long term treatment with nicotinic acid on lipids, lipoproteins, and the plasma distribution of very low density lipoproteins (VLDL) apoprotein C (ApoC) subspecies were studied in 33 patients with types IIa (n = 9), IIb (n = 11), and IV (n = 13) hyperlipidemias. After 6 months of treatment, a significant decrease in triglyceride, total cholesterol, and low density lipoprotein (LDL) cholesterol levels occurred. High density lipoprotein (HDL) cholesterol increased significantly by 31.1%, 41.8%, and 32.0% in types IIa, IIb, and IV, respectively (P less than 0.01 for all). A significant negative correlation existed between changes in HDL cholesterol and triglycerides (r = -0.613; P less than 0.02) in all groups studied. Therapy also produced changes in VLDL, LDL, and HDL protein concentrations. VLDL protein decreased from 20.9 +/- 3.9 to 15.2 +/- 1.0 mg/dl (P less than 0.05) in type IIa. In types IIb and IV, mean VLDL protein decreased from 44.7 +/- 8.2 to 27.1 +/- 3.9 mg/dl (P less than 0.001) and from 46.3 +/- 7.1 to 30.6 +/- 4.9 mg/dl (P less than 0.001), respectively. LDL protein decreased significantly, and HDL protein increased in type IIa only. Gel isoelectric focusing of VLDL before and after nicotinic acid in types IIb and IV hyperlipidemia produced a significant increase in the VLDL ApoC-II component with simultaneous decreases in the total VLDL ApoC-III subspecies. This resulted in increases in the ApoC-II to ApoC-III area ratio from 0.50 +/- 0.1 to 1.02 +/- 0.2 (P less than 0.001) in type IIb and from 0.62 +/- 0.07 to 0.88 +/- 0.13 (P less than 0.01) in type IV, respectively. The ApoE subspecies and the ApoE-III to ApoE-II area ratio did not change significantly. Our results show that nicotinic acid produces a significant improvement in the lipoprotein profiles of these patients.

Adult↗

Serum lipoprotein responses during active and stable weight reduction in reproductive obese females.

An increase in high density lipoprotein-cholesterol (HDL-C) and a reduction in low density lipoprotein-cholesterol (LDL-C) accompany weight reduction in obese males. In contrast, obese females have had variable responses in these two lipoproteins after weight reduction. To evaluate the effects of weight reduction in obese women, 15 morbidly obese eugonadotropic women of reproductive age had serum lipids and lipoproteins measured before and after achieving a stable and reduced weight by either diet and/or a gastric stapling procedure. Total testosterone (T), free testosterone (free T), and testosterone-binding globulin serum concentrations were also determined before and after achieving a stable reduced weight to assess the role of androgens in modulating any lipoprotein changes. In 10 subjects, lipid analysis was also performed during active weight loss. Total serum triglycerides fell from 106 +/- 53 to 76 +/- 30 mg/dl during active weight loss (P less than 0.025). Total cholesterol, LDL-C, HDL-C, and the LDL-C to HDL-C ratio did not change. In contrast, after achieving a stable reduced weight (mean weight reduction, 25.9 +/- 6.7 kg), HDL-C rose from 24 +/- 8 to 32 +/- 9 mg/dl (P less than 0.005). This was accompanied by a reduction in LDL-C from 145 +/- 23 to 135 +/- 30 mg/dl (P less than 0.01) and in the LDL-C to HDL-C ratio from 6.7 +/- 2.6 to 4.8 +/- 1.9 (P less than 0.001). Total triglycerides and total cholesterol were unchanged. After obtaining a stable reduced weight, testosterone-binding globulin increased and free T fell, but no significant correlation existed between the changes in androgens and the changes in lipoprotein responses. Thus, in morbidly obese women, weight reduction increases HDL-C and lowers LDL-C serum concentrations. The reduction in the LDL-C to HDL-C ratio suggests that weight loss may favorably reduce the risk of coronary artery disease in these patients. A concurrent reduction of free T with weight loss does not appear to be a major controlling influence in these lipoprotein alterations.

Adult↗

Thyrotrophin-producing pituitary adenomas.

Hyperthyroidism due to thyrotrophin (TSH)-secreting pituitary tumors is rare. Four cases are described, with the features that allow preoperative diagnosis. In all the patients, thyroid hormone production was consistently elevated despite antithyroid therapy, and TSH levels were inappropriately elevated. All patients were treated with both surgery and irradiation. Each patient had recurrent tumor with suprasellar, intrasphenoidal, or intraorbital spread. The combination of a recurrent, aggressive tumor complicated by thyrotoxicosis makes this a complex and difficult surgical problem.

Adenoma↗

Spurious elevations in glycosylated hemoglobin (HbA1) secondary to hypertriglyceridemia.

Measurement of glycosylated hemoglobin (HbA1) is frequently helpful to clinicians in treating patients with diabetes, since a number of studies show that this reflects a reliable index of diabetic control over time. There are several methods of measuring HbA. The chromatographic method is the most frequently used and is the standard method for large demand. We recently encountered a patient with diabetes mellitus who had substantial lactescent plasma secondary to hypertriglyceridemia that falsely raised the HbA1 level. We examined the patient in detail and determined that triglyceride concentrations greater than 1,750 mg/dL would falsely raise the HbA1 levels. In vitro studies performed by adding lipemic plasma to a control sample confirmed this. Thus, spurious elevations in HbA1 can occur in patients with lactescent plasma. This would further complicate the already existing interrelationship between glucose intolerance and hypertriglyceridemia.

Chromatography↗

Thyrotoxicosis and a thyrotropin-secreting pituitary tumor causing unilateral exophthalmos.

Hyperthyroidism due to a TSH-secreting pituitary tumor has been noted by a number of investigators. We describe a unique case in which a 17-yr-old female presented with clinical hyperthyroidism, a goiter, and unilateral exophthalmos. Serum T4, free T4, and T3 (RIA) were consistently elevated along with elevated TSH levels (range, 10-100 microunits/ml). Skull x-rays and computed tomography scan revealed a tumor invading the right orbit. Other pituitary function studies were normal and LATs was undetectable. Surgery performed resulted in 70% removal of the pituitary tumor and confirmed the presence of tumor infiltration into the right orbit. TRH tests done pre- and postoperatively (patient still clinically hyperthyroid with elevated T4 and TSH levels) showed TSH and PRL responsiveness. Electron microscopy of the tumor demonstrated features typical of pituitary thyrotrophs. Monolayer cultures of pituitary cells released TSH over time into the media but did not respond to TRH stimulation. Pituitary adenoma tissue content of immunoreactive TSH was 65 microunits/g wet tissue and demonstrated immunosimilarity with human standard. We conclude that the patient had a TSH-secreting pituitary tumor responsive to TRH stimulation.

Adenoma, Chromophobe↗

Metrizamide cisternography in the investigation of the empty sella syndrome.

Pneumoencephalography, the usual method for demonstrating air within the sella turcica in empty sella syndrome (ESS), has been approached with reluctance by most physicians because of its technical difficulty and patient morbidity. For these reasons, neuroradiologists have investigated other contrast media in search of an ideal agent; metrizamide seems to be such an agent. Metrizamide is a nondissociable, water-soluble glucose amide containing three iodine molecules. This agent is miscible with CSF, and small recesses of the CSF-brain interface can be delineated with hypocycloidal tomography without performing cumbersome patient maneuvers to fill the cisterns. Furthermore, morbidity has been minimal, particularly with use of lower concentrations of metrizamide, allowed by the sensitivity of computerized tomographic (CT) scanning. Thus, at the present time, metrizamide cisternography (especially in conjunction with CT scanning) appears useful in evaluating an enlarged sella turcica, particularly when considering an entity such as ESS.

Adult↗

The effect of increasing doses of ingested glucose on insulin and gastric inhibitory polypeptide (GIP) concentrations in man.

Gastric inhibitory polypeptide (GIP) is insulinotropic in vivo and in vitro. It is released following glucose ingestion and is a leading candidate as a mediator of the enteroinsular axis. To investigate the GIP response to increasing amounts of oral glucose, and its relationship to glucose levels and insulin secretion, fourteen normal volunteers ingested 25, 50 and 75 g of glucose at random with 5-7 days between each test. Serum insulin, glucose and GIP concentrations were measured and total integrated incremental responses were determined. Peak mean responses to glucose, insulin and GIP occurred at 30 min following each glucose ingestion. There were no significant differences in glucose concentrations at any interval with the varying glucose doses. Mean peripheral insulin concentrations were significantly increased after 50 or 75 g of glucose as compared with the 25 g dose (P less than 0.02). Mean GIP concentrations were significantly greater (P less than 0.03) between 15 and 180 min with both the 50 and 75 g glucose stimulus. Total integrated areas under the response curves for glucose, insulin and GIP showed a graded increase in circulating insulin and GIP (P less than 0.01) as the amount of ingested glucose was increased from 25 to 75 g. These findings show that increasing doses of glucose stimulated greater levels of GIP and insulin and further support the insulinotropic properties of endogenous GIP in man.

Administration, Oral↗

Benign parotid enlargement in bulimia.

Bulimia is an episodic compulsive urge to overeat often followed by recurrent attempts to lose weight by self-induced vomiting. Seven young women with this eating disorder and associated benign bilateral painless parotid enlargement are described. The glandular swelling was generally intermittent, with parotid enlargement usually developing 2 to 6 days after a binge overeating episode had stopped. Several had hypokalemic alkalosis and a moderate elevation in serum amylase levels. None had clinical evidence of pancreatitis, and a parotid gland biopsy in one patient was normal. The clinician should be alerted to the association of benign parotid enlargement with this syndrome.

Adolescent↗