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Papers by Vaidotas Urbanavicius
PubMed, Oct 1, 1980
Thirteen patients with prolactin-secreting and/or growth hormone secreting pituitary tumours have... more Thirteen patients with prolactin-secreting and/or growth hormone secreting pituitary tumours have been treated with bromocriptine in doses of about 10 mg/day for several months. Nine of these patients were previously submitted to external or interstitial radiotherapy and one case to pituitary microsurgery. Serum prolactin concentration in patients with prolactinomas was still very high within one year after pituitary irradiation or operation, i.e. 5,125.6 +/- 974 mU/l (mean +/- SEM). It has been reduced to normal level only during bromocriptine therapy, i.e. to 329.1 +/- 88mU/l (p less than 0.001), and increased thereafter, but remained to a significantly lower concentration than before bromocriptine treatment, i.e. 2,709.0 +/- 553 mU/l (p less than 0.05). Serial pneumonecephalotomography has demonstrated the reduction of tumour size afrer bromcriptine therapy to two prolactinomas with suprasellar extension. In patients with acromegaly the effects of bromocriptine were less evident. The antitumoral effects of bromocriptine on prolactin-secreting adenomas is independent and additional to the effects of pituitary radiotherapy or microsurgery, and has therapeuticical implications.
PubMed, Jul 1, 1980
Immunoreactive insulin level (IRI) in haemolyzed (HE) of normal fasting subjects was 49.2 +/- 3.5... more Immunoreactive insulin level (IRI) in haemolyzed (HE) of normal fasting subjects was 49.2 +/- 3.5 microU/ml. It was approximately 5 times higher compared within the plasma levels of the same subjects. Recovery and dilution tests for insulin in HE were positive. After an intravenous glucose load IRI in HE decreased to 14.3 +/- 3.6 microU/ml with 5 minutes and was low during 1 hour after glucose administration. Authors results suggest the presence of insulin in human erythrocytes and it release from erythrocytes during the first phase after glucose loading.
PubMed, Jul 1, 1980
ATP synthesis requires the presence of thyroid hormones that activate oxidative phosphorylation. ... more ATP synthesis requires the presence of thyroid hormones that activate oxidative phosphorylation. ATP supports the energy consuming reactions such as actin-myosin interaction, calcium and sodium pump, which are essential in a normal heart function. Thyroid insufficiency depresses mitochondrial oxidation, leading to ATP depletion which can not be compensated by activated glycolysis. Glycolysis under conditions of hypoxia due to accumulation of lactate or NADPH, impairs membrane permeability and mitochondrial function, causing enzyme release and pump failure. In severe hyperthyroidism an ATP deficiency occurs by uncoupling of oxidative phosphorylation, T4 stimulating the extra-mitochondrial metabolic pathways. There is a disproportion between consumption of O2 and nutrients and ATP production. The T4--T3 excess via trace metal (magnesium, copper, zinc, iron, etc.) chelation inhibits enzyme activity which had impaired ATP synthesis. At the same time the excess of T4 by stimulating ATP-ase causes heat release and dissipation of ATP, favouring cardiothyreosis.
Journal of Internal Medicine, Feb 1, 1995
Objective. To examine whether microalbuminuria in non-diabetic, treated hypertensive men is assoc... more Objective. To examine whether microalbuminuria in non-diabetic, treated hypertensive men is associated with insulin resistance and measures of endothelial function, thrombogenesis and fibrinolysis. Design. Cross-sectional study. Setting. Outpatient clinic in city hospital. Patients. Ninety-two treated hypertensive men, aged 57-77 years, either with a serum cholesterol of 2 6.5 mmol L-' or smokers, or both. Patients with diabetes mellitus or overnight urinary albumin excretion of > 100 mg 12 h-' were excluded. Main outcome measures. Overnight urinary albumin excretion, insulin-mediated glucose disposal (hyperinsulinaemic euglycaemic clamp), blood glucose and Results. Microalbuminuric patients had increased blood glucose concentrations during the oral glucose tolerance test and higher plasma fibrinogen levels compared with the normoalbuminuric patients. In a randomly selected subgroup (n = 36), insulinmediated glucose disposal was lower in microalbuminuric than in normoalbuminuric patients, and an inverse relationship between insulin sensitivity and albuminuria (r =-0. 3 7 : P = 0.028) was found. This relationship was not significant after adjustment for body-mass index (P = 0.098). In the univariate analyses including all patients, albuminuria was associated with blood glucose, serum creatinine, body-mass index, systolic blood pressure, fibrinogen, von Willebrand factor and cholesterol (negatively). In a multiple regression analysis, only the body-mass index was independently related to urinary albumin excretion. Conclusions. Microalbuminuria was associated with insulin resistance but obesity was a confounding factor. Relationships between microalbuminuria and fibrinogen as well as von Willebrand factor were found, but only in univariate analysis. plasma insulin during oral glucose tolerance test,
Several endogenous hormones have been proven to stimulate cancer growth, whereas at present very ... more Several endogenous hormones have been proven to stimulate cancer growth, whereas at present very few hormones are known to display oncostatic activity. The most widely investigated antitumor hormone is the pineal indole melatonin (MLT), and cancer progression has been shown to be associated with a decline in MLT secretion. Recently, another hormone, the adrenal steroid dehydroepiandrosterone-sulfate (DHEAS), has appeared to exert antitumor effects similar to those previously described for MLT. In addition, experimental studies suggest a diminished DHEAS production with neoplastic progression. This preliminary study was performed to evaluate the daily secretion of DHEAS in a group of early and advanced cancer patients. The study included 70 patients with solid tumors (gastrointestinal tract tumors: 28; breast cancer: 24; non-small cell lung cancer: 18), 28 without and 42 with distant metastases. The serum levels of DHEAS were measured by RIA in blood samples collected in the morning. The control group consisted of 100 age-and sex-matched healthy subjects. No significant difference in mean serum levels of DHEAS was observed between controls and non-metastatic patients. In contrast, metastatic patients, irrespectively of tumor histotype, showed significantly lower mean levels of DHEAS with respect to either controls or non-metastatic patients. Moreover, metastatic patients with visceral locations showed significantly lower values of DHEAS than those with bone or soft-tissue metastases. This preliminary study would suggest there to be a deficiency in the daily DHEA secretion in patients with disseminated cancer. Further studies evaluating circadian DHEAS secretion in relation to that of the pineal hormone MLT will be required to better define the biological significance of the advanced cancer-related decline in endogenous DHEAS production.
Acta Endocrinologica (Bucharest), 2018
Background. Mosaic karyotype 45,X/46,XY related mixed gonadal dysgenesis. Aim. To report a case o... more Background. Mosaic karyotype 45,X/46,XY related mixed gonadal dysgenesis. Aim. To report a case of mosaic karyotype and petroclival meningioma. Methods. Presentation of a clinical case with comments. Results. The case of a 37-year-old woman mosaic karyotype-45,X/46,XY, infertility, virilisation, Turner syndrome-like phenotype, primary amenorrhea, the absence of labia majora and petroclival meningioma. Concentrations of dehydroepiandrosterone sulphate (DHEAS), testosterone, luteinizing hormone (LH) and follicular stimulating hormone (FSH) were increased indicating hypergonadotropic hypogonadism. Low and high dose dexamethasone suppression tests demonstrated incomplete suppression of DHEAS concentration without connection between pulses of LH/FSH and DHEAS. Response to adrenocorticotropic hormone (ACTH) was normal. The morning/evening concentration ratio of DHEAS was very low in comparison with cortisol, ACTH and testosterone. Head magnetic resonance imaging (MRI) demonstrated petroclival meningioma without any adrenal or ovary abnormality. Menstruation started after treatment with 2 mg of estradiol. At control visit 1.5 years later she had no complaints. MRI did not demonstrate any signs of tumour progression. Conclusions. The main lesson learned from this case is that in searching the DHEAS secreting tumours one can find unusual cases with sustained high DHEAS and lack of confirmations of polycystic ovary syndrome, adrenal or ovary tumours using available ultrasound, CT and MRI.
Pädiatrie und Grenzgebiete, 1990
Insulin-degrading and insulinase-inhibiting activity of whole blood and erythrocytes of 146 child... more Insulin-degrading and insulinase-inhibiting activity of whole blood and erythrocytes of 146 children affected with acute leucosis of different stages were investigated. No statistically reliable difference between the data of insulin-degrading activity in acute leucosis and healthy children was found. Insulinase-inhibiting activity of both the hemolysate of blood and erythrocytes was increased in children in the active stage of the disease.
Acta endocrinologica, 2021
Objective To investigate the significance of DHEAS assessment in males of different ages. Methods... more Objective To investigate the significance of DHEAS assessment in males of different ages. Methods Retrospective cohort study of patients investigated in two large academic centres. Results The data of DHEAS assessment of 3533 patients (3013 females and 520 males) was analysed. DHEAS was 1.6 - 13.5 times more frequently investigated in women than in men. A peak of DHEAS evaluation test for women was at 25 years old and distribution was uniform in males over decades, excepting being lower in 0-9 and 75+ages. In the age group 10-24 years, DHEAS levels were higher in females. After 45 years, DHEAS was higher in men than in women. Analysis of 510 case records showed low DHEAS levels in boys (0-9 years) and in men aged 65 - 84+. Higher DHEAS levels were detected as a peak at 30 years old, but never after 55 years. In individuals with low DHEAS levels prevailed congenital adrenal hyperplasia (32%), adrenal tumours (30%) and primary or secondary adrenal insufficiency (19%). High DHEAS level...
Revue Roumaine de Morphologie d'Embryologie et de Physiologie Physiologie, Mar 7, 1980
Klinička psihologija, 2016
Objective: To determine the relation of the European Male Ageing Study (EMAS) Sexual function que... more Objective: To determine the relation of the European Male Ageing Study (EMAS) Sexual function questionnaire (SFQ) parameters in the groups of healthy (H) and type 1 diabetic (T1D) males and in groups of different ages and different centers of EMAS. Design and Method: The evaluation of EMAS SFQ of 204 persons: 82 H and 122 T1D patients was performed. The answers to the questions characterizing various domains of sexual activity were analyzed. Results: Results. Eight sexual parameters were counted. The ratio of H males (%) /40 - 49-year-old EMAS males (%) was above 1, except the frequency of erectile dysfunction which is very low in the group of H males and extremely high in the group of T1D males. The results were similar when the 50 - 59-year-old EMAS group was taken in comparison to H males. The H males group shows even more clear predominance while T1D males are similar to 50 - 59-year-old EMAS males. Comparing the results of H males and EMAS males from various centers the rarity ...
PubMed, Oct 1, 1980
Thirteen patients with prolactin-secreting and/or growth hormone secreting pituitary tumours have... more Thirteen patients with prolactin-secreting and/or growth hormone secreting pituitary tumours have been treated with bromocriptine in doses of about 10 mg/day for several months. Nine of these patients were previously submitted to external or interstitial radiotherapy and one case to pituitary microsurgery. Serum prolactin concentration in patients with prolactinomas was still very high within one year after pituitary irradiation or operation, i.e. 5,125.6 +/- 974 mU/l (mean +/- SEM). It has been reduced to normal level only during bromocriptine therapy, i.e. to 329.1 +/- 88mU/l (p less than 0.001), and increased thereafter, but remained to a significantly lower concentration than before bromocriptine treatment, i.e. 2,709.0 +/- 553 mU/l (p less than 0.05). Serial pneumonecephalotomography has demonstrated the reduction of tumour size afrer bromcriptine therapy to two prolactinomas with suprasellar extension. In patients with acromegaly the effects of bromocriptine were less evident. The antitumoral effects of bromocriptine on prolactin-secreting adenomas is independent and additional to the effects of pituitary radiotherapy or microsurgery, and has therapeuticical implications.
PubMed, Jul 1, 1980
Immunoreactive insulin level (IRI) in haemolyzed (HE) of normal fasting subjects was 49.2 +/- 3.5... more Immunoreactive insulin level (IRI) in haemolyzed (HE) of normal fasting subjects was 49.2 +/- 3.5 microU/ml. It was approximately 5 times higher compared within the plasma levels of the same subjects. Recovery and dilution tests for insulin in HE were positive. After an intravenous glucose load IRI in HE decreased to 14.3 +/- 3.6 microU/ml with 5 minutes and was low during 1 hour after glucose administration. Authors results suggest the presence of insulin in human erythrocytes and it release from erythrocytes during the first phase after glucose loading.
PubMed, Jul 1, 1980
ATP synthesis requires the presence of thyroid hormones that activate oxidative phosphorylation. ... more ATP synthesis requires the presence of thyroid hormones that activate oxidative phosphorylation. ATP supports the energy consuming reactions such as actin-myosin interaction, calcium and sodium pump, which are essential in a normal heart function. Thyroid insufficiency depresses mitochondrial oxidation, leading to ATP depletion which can not be compensated by activated glycolysis. Glycolysis under conditions of hypoxia due to accumulation of lactate or NADPH, impairs membrane permeability and mitochondrial function, causing enzyme release and pump failure. In severe hyperthyroidism an ATP deficiency occurs by uncoupling of oxidative phosphorylation, T4 stimulating the extra-mitochondrial metabolic pathways. There is a disproportion between consumption of O2 and nutrients and ATP production. The T4--T3 excess via trace metal (magnesium, copper, zinc, iron, etc.) chelation inhibits enzyme activity which had impaired ATP synthesis. At the same time the excess of T4 by stimulating ATP-ase causes heat release and dissipation of ATP, favouring cardiothyreosis.
Journal of Internal Medicine, Feb 1, 1995
Objective. To examine whether microalbuminuria in non-diabetic, treated hypertensive men is assoc... more Objective. To examine whether microalbuminuria in non-diabetic, treated hypertensive men is associated with insulin resistance and measures of endothelial function, thrombogenesis and fibrinolysis. Design. Cross-sectional study. Setting. Outpatient clinic in city hospital. Patients. Ninety-two treated hypertensive men, aged 57-77 years, either with a serum cholesterol of 2 6.5 mmol L-' or smokers, or both. Patients with diabetes mellitus or overnight urinary albumin excretion of > 100 mg 12 h-' were excluded. Main outcome measures. Overnight urinary albumin excretion, insulin-mediated glucose disposal (hyperinsulinaemic euglycaemic clamp), blood glucose and Results. Microalbuminuric patients had increased blood glucose concentrations during the oral glucose tolerance test and higher plasma fibrinogen levels compared with the normoalbuminuric patients. In a randomly selected subgroup (n = 36), insulinmediated glucose disposal was lower in microalbuminuric than in normoalbuminuric patients, and an inverse relationship between insulin sensitivity and albuminuria (r =-0. 3 7 : P = 0.028) was found. This relationship was not significant after adjustment for body-mass index (P = 0.098). In the univariate analyses including all patients, albuminuria was associated with blood glucose, serum creatinine, body-mass index, systolic blood pressure, fibrinogen, von Willebrand factor and cholesterol (negatively). In a multiple regression analysis, only the body-mass index was independently related to urinary albumin excretion. Conclusions. Microalbuminuria was associated with insulin resistance but obesity was a confounding factor. Relationships between microalbuminuria and fibrinogen as well as von Willebrand factor were found, but only in univariate analysis. plasma insulin during oral glucose tolerance test,
Several endogenous hormones have been proven to stimulate cancer growth, whereas at present very ... more Several endogenous hormones have been proven to stimulate cancer growth, whereas at present very few hormones are known to display oncostatic activity. The most widely investigated antitumor hormone is the pineal indole melatonin (MLT), and cancer progression has been shown to be associated with a decline in MLT secretion. Recently, another hormone, the adrenal steroid dehydroepiandrosterone-sulfate (DHEAS), has appeared to exert antitumor effects similar to those previously described for MLT. In addition, experimental studies suggest a diminished DHEAS production with neoplastic progression. This preliminary study was performed to evaluate the daily secretion of DHEAS in a group of early and advanced cancer patients. The study included 70 patients with solid tumors (gastrointestinal tract tumors: 28; breast cancer: 24; non-small cell lung cancer: 18), 28 without and 42 with distant metastases. The serum levels of DHEAS were measured by RIA in blood samples collected in the morning. The control group consisted of 100 age-and sex-matched healthy subjects. No significant difference in mean serum levels of DHEAS was observed between controls and non-metastatic patients. In contrast, metastatic patients, irrespectively of tumor histotype, showed significantly lower mean levels of DHEAS with respect to either controls or non-metastatic patients. Moreover, metastatic patients with visceral locations showed significantly lower values of DHEAS than those with bone or soft-tissue metastases. This preliminary study would suggest there to be a deficiency in the daily DHEA secretion in patients with disseminated cancer. Further studies evaluating circadian DHEAS secretion in relation to that of the pineal hormone MLT will be required to better define the biological significance of the advanced cancer-related decline in endogenous DHEAS production.
Acta Endocrinologica (Bucharest), 2018
Background. Mosaic karyotype 45,X/46,XY related mixed gonadal dysgenesis. Aim. To report a case o... more Background. Mosaic karyotype 45,X/46,XY related mixed gonadal dysgenesis. Aim. To report a case of mosaic karyotype and petroclival meningioma. Methods. Presentation of a clinical case with comments. Results. The case of a 37-year-old woman mosaic karyotype-45,X/46,XY, infertility, virilisation, Turner syndrome-like phenotype, primary amenorrhea, the absence of labia majora and petroclival meningioma. Concentrations of dehydroepiandrosterone sulphate (DHEAS), testosterone, luteinizing hormone (LH) and follicular stimulating hormone (FSH) were increased indicating hypergonadotropic hypogonadism. Low and high dose dexamethasone suppression tests demonstrated incomplete suppression of DHEAS concentration without connection between pulses of LH/FSH and DHEAS. Response to adrenocorticotropic hormone (ACTH) was normal. The morning/evening concentration ratio of DHEAS was very low in comparison with cortisol, ACTH and testosterone. Head magnetic resonance imaging (MRI) demonstrated petroclival meningioma without any adrenal or ovary abnormality. Menstruation started after treatment with 2 mg of estradiol. At control visit 1.5 years later she had no complaints. MRI did not demonstrate any signs of tumour progression. Conclusions. The main lesson learned from this case is that in searching the DHEAS secreting tumours one can find unusual cases with sustained high DHEAS and lack of confirmations of polycystic ovary syndrome, adrenal or ovary tumours using available ultrasound, CT and MRI.
Pädiatrie und Grenzgebiete, 1990
Insulin-degrading and insulinase-inhibiting activity of whole blood and erythrocytes of 146 child... more Insulin-degrading and insulinase-inhibiting activity of whole blood and erythrocytes of 146 children affected with acute leucosis of different stages were investigated. No statistically reliable difference between the data of insulin-degrading activity in acute leucosis and healthy children was found. Insulinase-inhibiting activity of both the hemolysate of blood and erythrocytes was increased in children in the active stage of the disease.
Acta endocrinologica, 2021
Objective To investigate the significance of DHEAS assessment in males of different ages. Methods... more Objective To investigate the significance of DHEAS assessment in males of different ages. Methods Retrospective cohort study of patients investigated in two large academic centres. Results The data of DHEAS assessment of 3533 patients (3013 females and 520 males) was analysed. DHEAS was 1.6 - 13.5 times more frequently investigated in women than in men. A peak of DHEAS evaluation test for women was at 25 years old and distribution was uniform in males over decades, excepting being lower in 0-9 and 75+ages. In the age group 10-24 years, DHEAS levels were higher in females. After 45 years, DHEAS was higher in men than in women. Analysis of 510 case records showed low DHEAS levels in boys (0-9 years) and in men aged 65 - 84+. Higher DHEAS levels were detected as a peak at 30 years old, but never after 55 years. In individuals with low DHEAS levels prevailed congenital adrenal hyperplasia (32%), adrenal tumours (30%) and primary or secondary adrenal insufficiency (19%). High DHEAS level...
Revue Roumaine de Morphologie d'Embryologie et de Physiologie Physiologie, Mar 7, 1980
Klinička psihologija, 2016
Objective: To determine the relation of the European Male Ageing Study (EMAS) Sexual function que... more Objective: To determine the relation of the European Male Ageing Study (EMAS) Sexual function questionnaire (SFQ) parameters in the groups of healthy (H) and type 1 diabetic (T1D) males and in groups of different ages and different centers of EMAS. Design and Method: The evaluation of EMAS SFQ of 204 persons: 82 H and 122 T1D patients was performed. The answers to the questions characterizing various domains of sexual activity were analyzed. Results: Results. Eight sexual parameters were counted. The ratio of H males (%) /40 - 49-year-old EMAS males (%) was above 1, except the frequency of erectile dysfunction which is very low in the group of H males and extremely high in the group of T1D males. The results were similar when the 50 - 59-year-old EMAS group was taken in comparison to H males. The H males group shows even more clear predominance while T1D males are similar to 50 - 59-year-old EMAS males. Comparing the results of H males and EMAS males from various centers the rarity ...