Metin Ozata

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The hormone leptin profoundly affects body weight and metabolism. Three human adults (two women, 35 and 40 yr old; one man, age 27) have been identified with a recessive mutation in the ob gene, which is homologous to the mutation in ob/ob mice, and produces leptin deficiency and morbid obesity. Because leptin replacement increases brain weight and changes(More)
Leptin signals the status of energy reserves to the brain. Leptin stimulates biosynthesis of TRH in vitro and influences the activity of the hypothalamic-pituitary-thyroid axis in vivo in rodents. Because blood levels of both leptin and TSH display diurnal variation with a distinct nocturnal rise, we sought to determine whether a relationship exists between(More)
BACKGROUND Many studies have evaluated patients with idiopathic hypogonadothropic hypogonadotropism (IHH), but few of these studies utilize event-related potentials (P300). AIMS To assess the cognitive functions of hypergonadotropic vs. hypogonadotropic patients. SETTINGS AND DESIGN The study group consisted of 41 untreated IHH patients, 32 untreated(More)
Several studies based on psychometric tests have determined an impairment of cognitive functions in patients with androgen deficiency. However, little is known about event-related potentials (ERPs) alterations in male hypogonadism. We investigated alterations of ERP in male hypogonadism before and 3 months after gonadotropin treatment. ERPs were elicited in(More)
In this report, we examine the effects of leptin on the intake of specific macro- and micronutrients in a female patient with leptin gene deficiency. The patient was studied off and on leptin at stable body weight, within the normal to mildly overweight range. The data were obtained by detailed dietary assessments, measuring dietary intakes by weighed food(More)
Leptin deficiency has been associated with extreme obesity and hyperphagia in rodents and humans. A rare genetic disorder in humans yields the absence of the hormone leptin, extreme obesity, and a ravenous appetite. Reports on these rare cases have indicated that therapy using leptin injections can yield significant weight loss and changes in appetite. The(More)
The electrophysiological results in 51 patients with diabetes mellitus type II were compared with those in 30 age and sex matched healthy control subjects. Peripheral and cortical latencies of median and tibial somatosensory evoked potentials (SEP), bilateral I-III and I-V interpeak latencies (IPL) of brainstem auditory evoked potentials (BAEP), bilateral(More)
OBJECTIVE To evaluate the cognitive function of patients with hypothyroidism, based on long-latency auditory event-related potentials (ERPs). METHODS We investigated alterations of P300 latency in patients with hypothyroidism before treatment and after restoration of euthyroidism. ERPs were elicited in 14 untreated patients with hypothyroidism (mean age,(More)
Functional alterations in the central nervous system and peripheral nerves are well documented in overt hypothyroidism, but not in subclinical hypothyroidism. Twenty-seven patients with subclinical hypothyroidism were compared with a control group of 20 age- and sex-matched subjects to determine whether subclinical hypothyroidism can lead to alterations in(More)
The effect of L-carnitine (LC) on brain stem auditory evoked potentials (BAEP), was examined in alloxan-diabetic rats. LC (200 mg kg-1, i.p., once daily) was given to diabetic rats starting from the third week after the induction of diabetes, lasting for 4 weeks. Age-matched non-diabetic rats served as controls. The latency of wave I and interpeak latency(More)