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Biomedical subjects

A Vagenakis

Publications and source records attributed to A Vagenakis.

14 recordsLinked to original sources
PubMed2001

Non hypoxia-related splenic infarct in a patient with sickle cell trait and infectious mononucleosis.

Splenic infarction in patients with sickle cell trait is usually related to hypoxic conditions, while non-hypoxia-related infarcts are extremely rare. We report on a case of a 17-year-old male patient, living at sea level, who developed a severe left upper quadrant abdominal pain during the course of a febrile episode. On physical examination he had a mildly palpable but extremely painful spleen. A spleen scan revealed 2 areas of impaired radionucleide distribution. Hepatic enzymes were moderately increased and the IgM anti-EBV antibodies positive. Hemoglobin electrophoresis revealed the presence of 42% of hemoglobin S. A probable diagnosis of splenic infarction was established in a patient with sickle cell trait, during the course of infectious mononucleosis. The patient was treated symptomatically. The conditions of splenic congestion induced by the EBV infection and the high-grade fever may have contributed to splenic sequestration and subsequent infarcts.

Adolescent↗
PubMed1999

Autoimmune cholangitis in a patient with celiac disease: a case report and review of the literature.

Autoimmune cholangitis is a rare chronic cholestatic liver disease. We describe the case of a 65-year-old woman with celiac disease who presented to us with fever, jaundice and weight loss. Serum biochemical study showed marked increase in alkaline phosphatase and gammaGT levels. Antinuclear antibodies were positive, while antimitochondrial and anti-smooth-muscle antibodies were negative. Liver biopsy was compatible with primary autoimmune cholangitis. The patient was successfully treated with azathioprine and methylprednisolone. We describe here the uncommon association of autoimmune cholangitis with celiac disease and review the prevalence of liver diseases in patients with celiac disease.

Aged↗
PubMed1992

Gallbladder contraction after hormonal manipulations in normal subjects and patients under total parenteral nutrition.

Total parenteral nutrition (TPN) induces biliary dilatation, sludge and formation of gallstones. Cholecystokinin (CCK) induces gallbladder (GB) contraction. During thyrotropin-releasing hormone (TRH) testing for thyroid function, we observed that patients felt a strong micturition reflex attributable to smooth muscle contraction of the bladder. The possibility of GB contraction after TRH administration was studied compared to cholecystokinin-octapeptide (CCK-OP) and/or fatty meal administration. The effect of intravenous (IV) CCK-OP, TRH and a combination of the two on GB volume was studied in normal volunteers without GB or liver disease and in patients receiving TPN for greater than 2 weeks. Subjects included six normal volunteers who received an oral fatty meal only, 18 other normal volunteers (Group A) and 18 TPN patients (Group B). Gallbladder contraction was estimated by ultrasound prior to and after administration of the fatty meal; in the other 36 subjects, GB contraction was calculated prior to and after administration of CCK-OP, TRH, or both. Results are expressed as a percentage of the GB basal volume using each subject as his or her own control. Group A and Group B were each divided into three equal subgroups receiving IV CCK-OP (A1, B1), TRH (A2, B2), or both (A3, B3).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

A simple stress test for the evaluation of hypothalamic-pituitary-adrenal axis during the first 6 months of life.

In 33 normal infants, divided into 3 age groups (less than 1 month, 1-3 months, and 3-6 months) plasma cortisol was measured at 2230, 2300, and 2330 h. Baseline plasma cortisol at 2230 h. was, as expected, low in all infants, with mean +/- SEM values of 41 +/- 5, 72 +/- 14, and 97 +/- 17 nmol/L in each group, respectively. Thirty and 60 min after the painful stimulus of the venipuncture, plasma cortisol increased significantly (P less than 0.0005), reaching a maximum increase up to 458 +/- 50, 392 +/- 66, and 455 +/- 97 nmol/L in each age group, respectively. We conclude that in these infants the hypothalamic-pituitary-adrenal axis was functionally intact and responded to the painful stimulus of the venipuncture by a significant increase in plasma cortisol. This test may be used as a simple procedure for the evaluation of the integrity of the hypothalamic-pituitary-adrenal axis without the administration of pharmacological agents. Its usefulness, however, should be validated with patients having a disorder of the system.

Adrenal Glands↗
PubMed1991

Diagnosis of thyroid cancer in southwestern Greece.

A prospective study of 1,200 patients with thyroid disease was performed from 1983 to 1988 to appraise the reliability of various diagnostic techniques in patients with thyroid cancer. Histologic confirmation was obtained in 201 patients. By assuming that only solid lesions, single or multiple, represented malignancy, the sensitivity and specificity of ultrasonography was 4.64 and 52.2%, respectively. Findings of fine needle aspiration (FNA) cytology and of carcinoembryonic antigen (CEA) serum concentration were also evaluated. The sensitivity and specificity of these two methods (91.2% and 84.1% for FNA and 89.7% and 81.3% for CEA, respectively) were found to be high enough to permit surgical intervention after a diagnosis of malignancy was made. It appears that the combination of FNA cytology and CEA serum measurement represents the most accurate method for the pre-operative detection of thyroid cancer.

Biopsy, Needle↗
PubMed1980

Failure of a serotonergic receptor-blocking drug to change the twenty-four-hour luteinizing hormone secretory pattern in women.

The 24-h LH secretory pattern in women during the early follicular phase is characterized by inhibition during the early sleep period. Methysergide maleate was administered to six normal women to test the hypothesis that the effect of sleep on LH secretion is due to serotonergic mechanisms. The results demonstrated no change in the sleep effect on LH secretion after drug administration. The 4-h average deviation after sleep onset from the 24-h mean was -27.7% for the control studies and -25.5% after methysergide maleate. The data suggest tht serotonergic pathways are not critically involved in the control of the 24-h LH secretory program in women.

Adult↗
PubMed1973

Effects of replacement doses of sodium L-thyroxine on the peripheral metabolism of thyroxine and triiodothyronine in man.

Studies of the effect of L-thyroxine administration (0.3 mg daily for 7-9 wk) on the peripheral metabolism of (131)I-labeled triiodothyronine (T(3)) and (125)I-labeled thyroxine (T(4)) and on the concentration and binding of T(4) and T(3) in serum were carried out in 11 euthyroid female subjects. Administration of L-thyroxine led to consistent increases in serum T(3) concentration (137 vs. 197 ng/100 ml), T(3) distribution space (39.3 vs. 51.7 liters), T(3) clearance rate (22.9 vs. 30.6 liters/day) and absolute T(3) disposal rate (30 vs. 58 mug/day), but no change in apparent fractional turnover rate (60.3 vs. 60.6%/day). The proportion and absolute concentration of free T(3) also increased during L-thyroxine administration. Increases in serum total T(4) concentration (7.3 vs. 12.8 mug/100 ml) and in both the proportion and absolute concentration of free thyroxine also occurred. In five of the subjects, the kinetics of peripheral T(4) turnover were simultaneously determined and a consistent increase in fractional turnover rate (9.7 vs. 14.2%/day), clearance rate (0.84 vs. 1.37 liters/day), and absolute disposal rate (64.2 vs. 185.0 mug/day) occurred during L-thyroxine administration. Despite these increases in the serum concentration and daily disposal rate of both T(4) and T(3), the patients were not clinically thyrotoxic. However, basal metabolic rate (BMR) values were marginally elevated and, as in frank thyrotoxicosis, T(4)-binding capacities of thyroxine-binding globulin (TBG) and thyroxine-binding prealbumin (TBPA) reduced, suggesting that subclinical thyrotoxicosis was present. Thus, the often recommended replacement dose of 0.3 mg L-thyroxine daily may be greater than that required to achieve the euthyroid state. The studies have also provided additional evidence of the peripheral conversion of T(4) to T(3) in man and have permitted the calculation that approximately one-third of exogenously administered T(4) underwent deiodination to form T(3). To the extent that a similar fractional conversion occurs in the normal state, it can be calculated that a major fraction of the T(3) in serum derives from the peripheral deiodination of T(4) and that only a lesser fraction derives from direct secretion by the thyroid gland.

Adult↗
PubMedDate not supplied

The effect of light on plasma melatonin levels in premature infants.

Recent studies have shown that full term neonates actively secrete melatonin and that light deprivation during the first 72 h of life significantly increases plasma melatonin levels. In order to evaluate pineal gland activity and responsiveness to light in premature infants, we measured plasma melatonin levels in 23 healthy infants, 33-36 weeks of gestation, during their first week of life. Nine infants (Group A) remained under constant illumination conditions for 48 hour prior to melatonin measurements. Fourteen infants (Group B) were exposed for the same time period to an artificial alternation of day and night cycles by covering the eyes of the infants with eye pads during the night (20.00-08.00 h). Mean +/- SEM plasma melatonin at 20.00 h, 04.00 h, 12.00 h and 20.00 h was 14.8 +/- 1.6, 16.2 +/- 2.8, 18.7 +/- 3.1, 20.9 +/- 3.1 pg/ml in Group A and 20.5 +/- 3.2, 22.3 +/- 2.9, 20.2 +/- 2.2, 18.5 +/- 2.2 pg/ml in Group B respectively. The differences observed between the two groups were not statistically significant. Our results indicate that at this gestational age the pineal gland is actively secreting melatonin but does not respond to the light alternations attempted. Further studies are needed in order to evaluate the developmental maturation of the pineal gland in humans.

Birth Weight↗