bluuebunny/crossref_metadata_2025 huggingface dataset:
Adrenal receptors for natriuretic peptides and inhibition of aldosterone secretion in calf zona glomerulosa cells in culture
Authors: Cozza Eduardo N , Foecking Mark F , Vila Maria del Carmen , Gomez-Sanchez Celso E
Published: June 2009

Atrial and brain natriuretic peptides specifically bind to primary cultures of calf adrenal glomerulosa cells. Binding of both natriuretic peptides to the same receptor has been proved by: a Dixon plot showing competitive effects for the binding of 125I-labeled brain natriuretic peptide in the presence of increasing concentrations of unlabeled atrial natriuretic peptide; a Scatchard plot showing a lower dissociation constant (Kd) for atrial natriuretic peptide than for brain natriuretic peptide binding, but the maximum binding (Bmax) values were the same; autoradiography of sodium dodecyl sulfate polyacrylamide gels after cross-linking of 125I-labeled atrial natriuretic peptide and 125I-labeled brain natriuretic peptide, showing the same molecular weights for both peptide receptors—a single 66-kD band in whole cells and a main band at 125 kD in membranes. C-Type atrial natriuretic peptide only slightly displaced atrial natriuretic peptide binding. Angiotensin II- and potassium-mediated stimulation of aldosterone production were inhibited strongly and to the same degree by atrial and brain natriuretic peptide but only slightly by C-type atrial natriuretic peptide. Stimulation of aldosterone production mediated by adrenocorticotropin was only partially inhibited by atrial and brain natriuretic peptide, while baseline aldosterone was not affected. These results suggest that atrial and brain natriuretic peptide bind to the same receptors and provoke the same effects on aldosterone production. The weak effects found with C-type atrial natriuretic peptide suggest that the primary culture of calf adrenal glomerulosa cells contain the guanylate cyclase A receptor.
Role of vagal nerves and atrial natriuretic hormone in vasopressin release and a diuresis under hypertonic volume expansion
Authors: Sato Kazutoshi , Kimura Tokihisa , Ota Kozo , Shoji Masaru , Inoue Minoru , Ohta Masahiro , Yamamoto Tadasu , Funyu Takeharu , Yoshinaga Kaoru , Abe Keishi
Published: June 2009

To assess whether increases in circulating atrial natriuretic hormone (ANH) in response to the plasma volume expansion, besides the volume receptor-mediated mechanisms, attenuate the arginine vasopressin (AVP) response to increased plasma osmolality and whether changes in plasma AVP and ANH affect renal solute excretion under hypertonic plasma volume expansion, hypertonic saline (0.95 mol/l saline) alone, hypertonic saline with 6% dextran (6D-HS) and hypertonic saline with 9% dextran (9D-HS) were administered into anesthetized dogs. In the control study, 0.15 mol/l NaCI alone was administered. Plasma AVP and ANH and cardiovascular and renal functions were determined. Hypertonic saline and 9D-HS also were administered into the vagotomized and sham operated dogs, and the same parameters were determined. Mean blood pressure and heart rate never changed in all the groups, but central venous pressure and plasma volume increased markedly in 6D-HS and 9D-HS groups. In the control and hypertonic saline groups, central venous pressure increased slightly but plasma volume never changed. Plasma AVP increased in the order of hypertonic saline, 6D-HS and 9D-HS, but plasma ANH increased in reverse order. Vagotomy restored the AVP response to 9D-HS to 75% of its response to hypertonic saline, with a marked rise in plasma ANH. Urine sodium and potassium excretion and urine flow increased in hypertonic saline, 6D-HS and 9D-HS groups, but these increases were comparable among the groups. In the control group, these parameters never changed. These results suggest that the volume receptor-mediated vagal neural and ANH responses to the plasma volume expansion may have an effect on the suppression of the AVP response to osmotic stimuli, and increased plasma ANH release never potentiated the natriuresis under the hypertonic plasma volume expansion.
Reduced responsiveness of the hypothalamic-pituitary-adrenal axis in Boran (Bos indicus) cattle infected with Trypanosoma congolense
Authors: Abebe Getachew , Eley Robert M , ole-MoiYoi Onesmo K
Published: June 2009

The response of the pituitary-adrenal axis to corticotrophin-releasing hormone (CRH) and the adrenal response to adrenocorticotrophin hormone (ACTH) stimulation were studied during infection of Boran (Bos indicus) cattle with Trypanosoma congolense. For CRH, 15 animals were challenged during pre-infection and infection phases, while for ACTH 10 animals were challenged during pre-infection, infection and post-treatment phases of the experiments. The axis showed a reduced responsiveness after CRH challenge during patent parasitaemia, manifested by low (p<0.05) plasma ACTH and cortisol concentration as compared to the pre-infection CRH challenge concentrations. Cortisol concentration after ACTH challenge during pre-infection, infection and post-treatment phases did not differ. The reduced pituitary-adrenal response to CRH challenge and the normal adrenal response to ACTH challenge found during trypanosomiasis indicates pituitary dysfunction due to infection.
Kinetic changes of melatonin release in rat pineal perifusions at different circadian stages. Effects of corticosteroids
Authors: Zhao Zi-Yan , Touitou Yvan
Published: June 2009

The kinetic characteristics of melatonin release were documented in perifused pineal glands removed from rats sacrificed at six circadian stages (light/dark =12:12): three during the light phase, i.e. 3, 7 and 11 hours after light onset (HALO), and three during the dark phase, i.e. 15, 19 and 23 HALO. Whatever the circadian stage, the melatonin release decreased during the first 3–4 h and then remained fairly constant and roughly similar up to 8 h of perifusion. However, the kinetics of the release in the first 3 h differed in perifusions of pineal glands removed during the light (progressive decline during 3 h) as compared to perifusions of pineal glands removed during the dark (sharp decline during the first hour and then a progressive decline until reaching a constant level after 3 h).

As the effects of steroid administration on melatonin secretion are a matter of controversy, we also studied the direct effects and their circadian stage dependence, if any, of corticosterone, deoxycorticosterone and dexamethasone on melatonin secretion by pineal glands removed 7 HALO (about the middle of the light phase) and 19 HALO (about the middle of the dark phase). High concentrations of corticosterone (0.8 × 10−1 mol/l) and dexamethasone (0.4×10−3 mol/l) resulted in a significant (p<0.001) inhibitory effect on melatonin production (about a 50% and a 30% decrease, respectively) whatever the circadian stage, whereas lower concentrations (10−4–10−5 mol/l of both steroids did not affect melatonin production. In addition, neither pharmacological (1.06 × 10−5 mol/l) nor physiological (for the rat) concentrations (2.1 × 10−7 mol/l) of deoxycorticosterone had any significant effect on pineal melatonin production. These data clearly show the time dependence of the kinetics of melatonin release and an effect of adrenocortical steroids on pineal melatonin production that may be quite different according to the steroid and dosage.
Twin genes and endocrine disease: CYP21 and CYP11B genes
Authors: Helmberg Arno
Published: June 2009

CYP21 and CYP11B genes have a common feature: they are "twin" genes. It seems as if doubling and subsequent drifting apart rendered these genes particularly sensitive to defect acquisition by mechanisms involving recombinatorial events. This creates specific difficulties in the molecular diagnosis of defects.
Effect of growth hormone and insulin-like growth factor I on urinary albumin excretion: studies in acromegaly and growth hormone deficiency
Authors: Hoogenberg Klaas , Sluiter Wim I , Dullaart Robin PF
Published: June 2009

Glomerular hyperfiltration is a characteristic feature of acromegaly but it is uncertain whether albuminuria is elevated in this disease. To investigate the role of abnormal growth hormone (GH) and insulin-like growth factor I (IGF-I) levels on urinary protein excretion, we measured the overnight urinary albumin excretion rate (UalbV) and creatinine clearance in 14 acromegalic patients with metabolically active disease (fasting GH > 5 μg/l and IGF-I > 2.2 kU/l), 8 GH-deficient patients and 20 control subjects. The UalbV was higher in the acromegalic patients (median 8.4 (range 4.2–68.2) μg/min) than in the GH-deficient patients (2.0(0.9–5.9) μg/min, p< 0.001) and control subjects (3.3 (1.0– 7.8) μg/min, p <0.01). Five acromegalic patients had UalbV levels above the normal upper normal limit of 10 μg/min. Only one patient with concomitant untreated hypertension had persistent microalbuminuria. Creatinine clearance also was higher in the acromegalic patients (p<0.05) and lower in the GH-deficient patients (p <0.05) than in the control subjects. In 11 of these acromegalic cases, the lowering of GH by 63% and of IGF-I by 48%, following treatment with the somatostatin analogue (N = 10) or spontaneous pituitary infarction (N=1), reduced the UalbV by 29% to 4.9 (3.1–45.2) μg/min (p<0.01). Among the acromegalic patients (25 observations), the UalbV was related to GH (r=0.61, p<0.01), IGF-I (r=0.57, p<0.01) and creatinine clearance (r=0.54, p<0.01). In conclusion, circulatory GH and IGF-I levels influence albuminuria. Because persistent microalbuminuria is uncommon in acromegaly, it is unlikely that GH elevation alone predisposes to clinically important glomerular damage.
Parathyroid hormone is able to enhance cyclic adenosine monophosphate formation without causing an increase in cytoplasmic Ca2+ in osteoblasts
Authors: Ljunggren Östen , Johansson Hans , Ridefelt Peter , Lerner Ulf H , Lindh Erik , Johansson Anna G , Ljunghall Sverker
Published: June 2009

There are several reports indicating that parathyroid hormone (PTH), besides inducing the formation of cyclic adenosine monophosphate (cAMP), also causes an increase in cytoplasmic free Ca2+ ([Ca2+]i) in osteoblasts, and it has been speculated that both of these second messengers are necessary to mediate PTH-induced bone resorption. In the osteoblastic cell line MC3T3-E1, bovine PTH 1–34 (10 nmol/l-1 μmol/l) stimulated cAMP formation but did not cause an increase in [Ca2+]i in adherent single cells (basal [Ca2+]i=151±5 nmol/l, mean±sem; N = 98). In contrast, subsequent addition of bradykinin (1 μmol/l) resulted in a transient increase in [Ca2+]i from a basal level of 155±11 nmol/l to a peak value of 351±60 nmol/l (N= 14). When the PTH challenge was followed by the addition of thrombin (10 U/ml), the latter induced a transient rise in [Ca2+]i from a basal level of 173±12 nmol/l to a peak at 341±33 nmol/l (N=20). Primary cultures of human osteoblasts were obtained from trabecular bone. These cells were also PTH-responsive in terms of cAMP formation. On the other hand, human PTH 1– 34 (100 nmol/l) did not affect [Ca2+]i in the isolated human osteoblasts, while bradykinin (1 μmol/l) caused a transient increase in [Ca2+]i (from a basal value of [Ca2+]i at 154±10 nmol/l to a peak value of 757±147 nmol/l within 30s;N= 16). Neither in the human osteosarcoma cell line SaOS-2 (basal value of [Ca2+]i at 94±10 nmol/l; N = 24), nor in the rat osteosarcoma cell line ROS 17/2.8 (basal value of [Ca2+]i at 85±9 nmol/l; N=9) was any effect of PTH (0.1 nmol/l-1 μmol/l) on [Ca2+]i demonstrated. In conclusion, we were unable to detect any effect of PTH on [Ca2+ ]i in single MC3T3-E1 cells, in isolated human osteoblasts, in SaOS-2 or in ROS 17/2.8 cells, whereas accumulation of cAMP was always seen. This indicates that cAMP is the major second messenger for PTH in osteoblasts.
Reduced bone mineral content in adult patients with growth hormone deficiency
Authors: Rosén Thord , Hansson Tommy , Granhed Hans , Szucs Janos , Bengtsson Bengt-Åke
Published: June 2009

Bone mineral content was measured in a follow-up study of adult patients with hypopituitarism and growth hormone deficiency. There were 95 patients (59 males, mean age 54.0 years, range 21–74 years; 36 females, mean age 53.5 years, range 31–73 years). Routine replacement therapy with cortisone acetate and l-thyroxine was given. All males that were gonadal deficient were on proper testosterone therapy, except in four patients who were treated separately. Bone mineral content (g/cm) was measured using dual-photon absorptiometry in the third lumbar vertebra. Bone mineral content in the patients was compared with a control population (N=413, 25–74 years of age). Bone mineral content was significantly lower in males (N= 55, p<0.05) compared with controls. In females, bone mineral content was significantly lower both among the subjects with untreated gonadal deficiency (p<0.001) and among those with treated gonadal deficiency and normal premenopausal gonadal function (p<0.005) compared with controls. To summarize, patients with hypopituitarism on routine replacement therapy but not growth hormone have a lower bone mineral content than the controls. The reduced bone mineral content might be a result of untreated growth hormone deficiency.
Lipoprotein(a) and postmenopausal oestrogen
Authors: Farish Elizabeth , Rolton Hilary A , Barnes Judith F , Fletcher Colin D , Walsh David J , Spowart Keith JM , Hart David M
Published: June 2009

Epidemiological studies have shown that postmenopausal oestrogen therapy substantially reduces the risk of cardiovascular and cerebrovascular disease and this is partly mediated by oestrogen-associated changes in lipoproteins, particularly high-density lipoprotein. In this study, we investigated whether changes in lipoprotein(a) might help to account for the reduction in coronary heart disease and stroke associated with postmenopausal oestrogen therapy. The study group consisted of 18 women who had hysterectomy and bilateral oophorectomy at least 2 months prior to recruitment and had received no previous hormonal therapy. Serum samples were collected for measurement of lipoprotein(a) before and after 4 months of treatment with oestradiol valerate (2 mg/day). Lipoprotein(a) levels ranged from 35 to 720 mg/l (median 180 mg/l) before treatment and from 55 to 780 mg/l (median 1 30 mg/l) after oestradiol treatment and showed no consistent pattern of change. It would appear, therefore, that treatment with unopposed oestrogen in relatively low doses does not have a marked effect on lipoprotein(a), at least in the short term.
Endocrine and morphological features of cystic ovarian condition in antiprogesterone RU486-treated rats
Authors: Sánchez-Criado José E , Sánchez Antonio , Ruiz Antonio , Gaytán Francisco
Published: June 2009

Four-day cyclic Wistar rats (200 g body wt) were injected (sc) with the antiprogestagen RU486 (4 mg RU486/0.2 ml oil) on estrus, metestrus, diestrus and proestrus. Groups of rats (12–15) were decapitated on days 1 (day of expected ovulation), 5, 9, 13, 17 and 21 after the 4 days of RU486 treatment. Oil-injected rats decapitated on proestrus (day 0) and estrus (day 1 ) served as controls. In both controls and RU486-treated rats, the following parameters were noted: ovulation, vaginal smears and luteinizing hormone (LH), follicle-stimulating hormone (FSH), prolactin, testosterone and estradiol-1 7β serum concentrations. Also, pituitary, adrenal, uterus and ovary weight were recorded. RU486 induced ovulation blockade, persistent vaginal cornification, uterine ballooning and increased serum levels of LH, FSH, prolactin, testosterone and estradiol. Furthermore, the LH/FSH and testosterone/estradiol ratios in serum increased. Pituitary and ovary weights also increased. The enlarged ovaries showed follicular cysts undergoing atresia and/or different degrees of luteinization of granulosa cells resembling, in some cases, genuine corpus luteum containing the ovocyte. The small follicles showed extensive atresia and stimulated thecal cells. These effects are reversible and remain in a stationary state for about 9–13 days after RU486 treatment. While the endocrinological alterations found in rats treated with RU486 are similar to those exhibited in polycystic ovarian disease, the morphological alterations found in the ovaries seem to be more closely related to the multicystic ovarian condition. Overall, the results suggest that progesterone deficiency may be of relevance in the initiation of the cystic condition in the rat, and support the concept that a lack of progesterone is conducive to the perpetuation of the cystic state after the cyst follicles first develop.
Proopiomelanocortin, prolactin and growth hormone messenger ribonucleic acid levels in the fetal sheep pituitary during late gestation
Authors: Merei Jennifer J , Rao Alix , Clarke lain J , McMillen I Caroline
Published: June 2009

We have measured the relative levels of proopiomelanocortin (POMC), prolactin (PRL) and growth hormone (GH) messenger ribonucleic acid (mRNA) in the anterior and neurointermediate lobes of the fetal pituitary during the last 2–3 weeks of gestation. The mean POMC mRNA/18S RNA ratio in the fetal anterior pituitary was significantly greater (p<0.02) at 130–136 days (0.90±0.08; N=9) than at 141–143 days of gestation (0.67±0.07; N=6). In contrast, the mean PRL mRNA/18S RNA ratio increased significantly (p< 0.02) ) between 130 and 136 days (0.31±0.05; N = 9) when compared with 141–143 days of gestation (0.58±0.10; N = 6). There was no significant difference, however, between the mean GH mRNA/18S RNA ratio in fetal anterior pituitaries at 130–136 days (0.95±0.04; N = 9) when compared with 141–143 days of gestation (1.08±0.14; N=6). The POMC mRNA/18S RNA ratio in the neurointermediate lobes was seven-, five- and tenfold higher than in anterior pituitaries at 130–134, 135–136 and 141–143 days of gestation, respectively. We hypothesize that elevated circulating cortisol levels after 140 days of gestation act in the slow time domain (i.e. over days) to suppress POMC gene expression and that the increase in fetal pituitary PRL mRNA levels may be a consequence of oestrogen stimulation in late gestation.
Intraventricular injection of agents that enhance cyclic adenosine monophosphate formation leads to inhibition of proestrous luteinizing hormone surge in rats
Authors: Taleisnik S , Haymal B , Caligaris L
Published: June 2009

The effect of increasing hypothalamic levels of 3′,5′-cyclic adenosine monophosphate (cAMP) on the preovulatory surge of luteinizing hormone (LH) and ovulation was studied in cycling rats. Animals bearing chronically implanted guiding cannulae into the third ventricle were injected with agents known to enhance the cellular levels of cAMP. Hourly blood samples from the unanesthetized, unrestrained rats were obtained between 11.00 and 1 7.00 h through a plastic cannula inserted into the jugular vein. Intraventricular injections of serotonin (7.5 mg/ml; 2 μl) in the morning of proestrous blocked the preovulatory surge of LH and ovulation. This effect was assigned to an increased neuronal level of cAMP because it was prevented by a serum anti-cAMP. Third-ventricle injections of 2 μl of forskolin (0.5 mmol/l), guanosine 5′-0-(3-thiotriphosphate) (2 mmol/l) or dibutyryl-cAMP (1 mmol/l) at 11.00 h on the day of proestrus mimicked the inhibitory effect of serotonin on the proestrous release of LH. It is suggested that serotonin inhibits LH surge by acting directly on LH-releasing hormone neurons and/or on neurons that provide inputs to these neurons involving cAMP as a second messenger. Neurons releasing γ-aminobutyric acid (GABA) may serve as interneurons sensitive to serotonin, as well as to cAMP, inasmuch as the inhibitory effect of forskolin on the release of LH was partially blocked by the GABA antagonists, picrotoxin and bicuculline.
The prevalence of radiographic osteoarthritis is low in elderly patients with growth hormone deficiency
Authors: Bagge Eva , Edén Staffan , Rosén Thord , Bengtsson Bengt-Åke
Published: June 2009

The prevalence of radiographic osteoarthritis in hand and knee joints was studied in elderly patients with acromegaly and growth hormone deficiency, respectively, and compared with a normal population of elderly people. There were no major differences in the prevalence of osteoarthritis between the acromegalics and the normal population, but the patients with growth hormone deficiency had significantly (p<0.001) less osteoarthritis than the normal population. The lack of differences between the acromegalics and the normal population could be an effect of the age interval studied in which the prevalence of osteoarthritis is high. The low prevalence of osteoarthritis in patients with growth hormone deficiency suggests that growth hormone is an important factor in the development of osteoarthritis.
Hormonal status and clinical relevance of hirsutism in elderly women
Authors: Pepersack Thierry , Rossi Camelia , Dupuis Françoise , Lefevre André , Vanhaeverbeek Michel , Dekoninck Willy
Published: June 2009

Hirsutism is a common condition of elderly women, but its aethiopathogeny and its clinical implications remain unclear. We therefore studied circulating androgen concentrations in elderly women. In addition, this study aims to define a possible relationship between hirsutism and anthropometric determinations, bone mass and serum lipids. Androgen levels were determined at basal state, after adrenocorticotrophin (ACTH) stimulation and after dexamethasone administration in 10 hirsute elderly women and compared to 10 age-matched non-hirsute women. Anthropometric determinations included measurements of skinfold thickness and body mass index. Spinal bone mass density was assessed using dual photon absorptiometry. Hirsute women presented significantly higher levels of testosterone than controls (1.49±0.38 vs 0.59±0.05 nmol/l, mean±sem; p<0.05) and dihydrotestosterone (0.54±0.07 vs 0.32±0.03; p<0.02). 1 7-hydroxyprogesterone levels after ACTH stimulation tended to be higher in hirsute women than in controls. No differences were observed between the two groups in serum oestrogen concentrations, plasma lipid pattern or bone mineral density. Hirsute women had a lower body mass index and lower calculated percentage body fat than the control group. We conclude that:

(i) hirsutism of elderly women is associated with increased androgen levels, probably from adrenal origin;

(ii) in some cases, enhanced response in 17-hydroxyprogesterone after ACTH stimulation suggests a partial adrenal 21-hydroxylase deficiency;

(iii) hirsute women present anthropometric characteristics compatible with the known anabolic effect of androgens on fat-free mass.
Peripheral vein, ovarian vein and ovarian tissue levels of inhibin in a postmenopausal patient with a granulosa cell tumour
Authors: Sluijmer Alexander V , Heineman Maas J , Evers Johannes LH , de Jong Frank H
Published: June 2009

In a patient with a granulosa cell tumour, stage 1a1, peripheral and ovarian vein blood samples were drawn before, during and after bilateral oophorectomy. Before operation inhibin and follicle-stimulating hormone levels were in the premenopausal range, whereas the peripheral level of oestradiol and luteinizing hormone were in the normal postmenopausal range. In the ovarian vein at the side of the tumour, inhibin and oestradiol levels were elevated, whereas in the contralateral ovarian vein the concentrations of inhibin and oestradiol were in the same range as in the peripheral vein. Immunoreactive inhibin levels in the homogenized tumour were 23 times higher than in the contralateral ovary, whereas inhibin bioactivities in the same samples amounted to 126 and 14 U/mg protein, respectively. After removal of the tumour, peripheral serum follicle-stimulating hormone and inhibin levels were in the normal postmenopausal range again. We conclude that inhibin can have a role as a marker for granulosa cell tumours.
Pentoxifylline inhibits the proliferation and glycosaminoglycan synthesis of cultured fibroblasts derived from patients with Graves' ophthalmopathy and pretibial myxoedema
Authors: Chang Chih-Cheng , Chang Tien-Chun , Kao Shine CS , Kuo Yea-Fhey , Chien Li-Fei
Published: June 2009

Excessive amounts of glycosaminoglycans accumulate in the extraocular muscles of patients with Graves' ophthalmopathy and in the affected skin of patients with pretibial myxoedema. It is widely accepted that fibroblasts are the sources of glycosaminoglycan synthesis. Pentoxifylline, an analogue of the methylxanthine theobromine, inhibits the proliferation and certain biosynthetic activities of fibroblasts derived from normal human skin and from skin of patients with some fibrotic disorders. Our objective was to determine whether pentoxifylline has similar effects on fibroblasts derived from patients with Graves' ophthalmopathy and pretibial myxoedema and could serve as a candidate for the treatment of these manifestations. Fibroblasts from the extraocular muscles of two patients with Graves' ophthalmopathy and normal extraocular muscles of two subjects with strabismus, as well as the affected skin of two patients with pretibial myxoedema were cultured in vitro in the presence and absence of pentoxifylline to assay its effect on the proliferation of fibroblasts and their production of glycosaminoglycans. In subconfluent fibroblast cultures, pentoxifylline treatment caused a dose-dependent inhibition of serum-driven fibroblast proliferation. In confluent fibroblast cultures both in the presence and absence of serum, exposure to pentoxifylline similarly resulted in a dose-dependent inhibition of glycosaminoglycan synthesis for all these different kinds of fibroblasts. These findings may form the rationale for a clinical trial using pentoxifylline for the treatment of Graves' ophthalmopathy and pretibial myxoedema.
Thyroid peroxidase: kinetics, pH optima and substrate dependency
Authors: Kootstra PR , Wever R , de Vijlder JJM
Published: June 2009

The oxidation of iodide, guaiacol and 2, 2′-azino-di[3-ethyl-benzthiazoline-(6)-sulphonic acid] and the iodination of tyrosyl residues in bovine serum albumin, catalysed by partly purified thyroid peroxidase, were studied. The enzyme showed pH optima with all electron donors. With the exception of guaiacol, the positions of the pH optima depended upon both the electron donor and hydrogen peroxide concentrations. With increased hydrogen peroxide concentrations the optima shifted to lower pH, and with increased iodide concentration to higher pH. For monoiodotyrosine (MIT) formation in bovine serum albumin the position of the pH optimum was also dependent on the hydrogen peroxide concentrations. The position of the pH optimum of the oxidation of guaiacol was pH 9 and independent of substrate and hydrogen peroxide concentrations. It is obvious from these findings that iodination reactions must be studied under well-defined conditions.
Parathyroid hormone-related peptide and milking-induced phosphaturia in dairy cows
Authors: Barlet Jean-Pierre , Abbas S Khawar , Care Anthony D , Davicco Marie-Jeanne , Rouffet Josette
Published: June 2009

Five intact and four thyroparathyroidectomized (TPTX) lactating dairy cows were fitted with polyvinyl catheters implanted into the left carotid artery and the left mammary vein (for blood sampling) and into the right external jugular vein (for injections), and with a Foley catheter inserted into the urinary bladder. In these nine cows, daily morning and evening milking induced a prompt and transient rise in mammary venous blood plasma parathyroid hormone-related peptide (PTHrP)(1–34) concentrations, followed by an increase in both urinary phosphate concentration and phosphate renal clearance. Such a milking-induced phosphaturia was not observed when (tyr)34-bPTH(7–34)-NH2 (5 pmol/kg body wt) was infused during milking into the TPTX cows. These results indicate that PTHrP released systemically by the mammary gland during milking might be responsible for the observed phosphaturia.
Amount of G-protein α-subunit in rat white adipocytes: lack of difference between subcutaneous and visceral fat
Authors: De Pergola Giovanni , Xu Xuefan , Eriksson Peter S , Carlsson Björn , Fu Ljang-Xiong , Yang Shumin , Edén Staffan , Giorgino Riccardo , Björntorp Per
Published: June 2009

It has been the purpose of this study to examine possible differences in the amount of stimulatory (Gs) and inhibitory (Gi) G-protein α-subunits (measured with a quantitative enzyme-linked immunosorbent assay in fat cell membrane preparation) between subcutaneous and intra-abdominal regions in rats. The lipolytic response to isoproterenol and the number of β-adrenergic binding sites were also examined. These parameters were all evaluated simultaneously in subcutaneous (inguinal), epididymal and perirenal fat samples collected from six male Sprague-Dawley rats. The membrane contents of the Gs and Gi α-subunits were similar in the three depots. Moreover, no difference was found among the different regions with regard to isoproterenol-stimulated glycerol release and β-adrenoceptor number, expressed per cell number. In conclusion, the present study shows for the first time in rats that the abundance of inhibitory and stimulatory G-protein α-subunits is similar in subcutaneous and in visceral adipocytes. Moreover, the number ofβ-adrenoceptors and the lipolytic response to isoproterenol do not show significant variations with the anatomical site. As the present results are apparently in contrast with those obtained previously in human adipocytes, there is a possibility that the different results observed in rat and in human fat cells could be explained by species differences.
Results of ultrasonically guided percutaneous ethanol injection into parathyroid adenomas in primary hyperparathyroidism
Authors: Vergès Bruno L , Cercueil Jean P , Jacob Denis , Vaillant Geneviève , Brun Jean M , Putelat Roger
Published: June 2009

Surgery is the usual treatment for primary hyperparathyroidism. However, some patients with high surgical risks are not suitable for surgery. For such patients, we propose, as an alternative treatment, ultrasonically guided percutaneous ethanol injection into parathyroid adenomas, in order to induce necrosis of the tumor. We report, here, the results of ultrasonically guided percutaneous ethanol injection into parathyroid adenomas, during a prolonged follow-up period up to 49 months, in a group of 13 patients (median age 79 years) with primary hyperparathyroidism and contraindications for surgery. In seven patients, complete normalization of plasma calcium, phosphorus and parathyroid hormone (PTH) levels was achieved after ethanol injections, with no recurrence of hypercalcemia during a median follow-up period of 28 months (total success). In these seven patients, plasma calcium, phosphorus and PTH levels were normalized 48 h after the successful ethanol injection. In four patients, a partial success was obtained with clinical improvement and normalization of plasma calcium levels but without complete normalization of plasma PTH levels. This partial success is due to incomplete necrosis of the adenoma, as has been confirmed in one patient by histopathological examination. The ethanol injection treatment failed in only two patients. This treatment was always well tolerated and no major side-effects were observed. In conclusion, our results give evidence that ultrasonically guided percutaneous ethanol injection into parathyroid adenomas can be a very useful alternative therapy in patients not suitable for surgery.
Urinary growth hormone excretion in acromegaly: diagnostic value in mild disease activity
Authors: Main Katharina M , Lindholm Jörgen , Vandeweghe Mark , Skakkebaek Niels E
Published: June 2009

The biochemical assessment of disease activity in acromegaly still presents a problem, especially in treated patients with mild clinical symptoms. We therefore examined the diagnostic value of the measurement of urinary growth hormone (GH) excretion in seventy unselected patients with acromegaly of different activity by comparing it to serum GH, serum insulin-like growth factor I (IGF-I) and clinical activity. There were highly significant, positive correlations between urinary GH and serum GH, serum IGF-I as well as clinical activity score (p<0.00005), although some overlap between the groups was observed. In seven patients with low serum GH values (<2.0 μg/l) discordant results were found. Two of the seven patients were clinically mildly active, but only IGF-I was either elevated or within the upper normal range; in three other patients who appeared clinically cured either IGF-I (N = 1) or urinary GH (n = 2) alone were increased. In the remaining two patients elevated serum IGF-I and urinary GH as well as activity score suggested disease activity. Thus, in the majority of cases, urinary GH was significantly correlated to the other three parameters, but added little information to that obtained by serum IGF-I. In conclusion, urinary GH measurements in difficult cases may provide a more direct information on the GH status than IGF-I.
Growth hormone-releasing activity of growth hormone-releasing peptide-1 (a synthetic heptapeptide) in children and adolescents
Authors: Laron Zvi , Bowers Cyril Y , Hirsch Daniel , Almonte Antonio Selman , Pelz Moshe , Keret Ruth , Gil-Ad Irit
Published: June 2009

The heptapeptide growth hormone-releasing peptide-1 (GHRP-1 ), one of a series of recently synthesized small growth hormone (GH)-releasing peptides, was administered as an iv bolus (1 μg/kg) to 15 (six prepubertal, nine pubertal) short but healthy children and adolescents and to eight juvenile patients with pituitary insufficiency (four with isolated growth hormone deficiency, two with multiple pituitary hormone deficiencies, one with partial GH deficiency and one with GH-releasing hormone (GHRH) deficiency). Eleven out of 23 subjects also underwent an iv GHRH (1–29) test (1 μg/kg). All the healthy children responded with a progressive rise in plasma human GH (hGH) peaking at 15–30 min, with a significantly higher rise (p<0.05) in the pubertal than prepubertal group. The hGH response to GHRH (1–29) in these children was similar or slightly higher. Six hypopituitary patients had no response to either GHRP-1 or GHRH; the patient with partial GH deficiency had a hGH peak of 6.5 μg/l (at 5 min) to GHRP-1 and 9.2 μg/l (at 1 5 min) to GHRH. One patient had no response of hGH to hypoglycemia, clonidine and GHRP-1, but the plasma hGH rose to 10 μg/l after GHRH. Following the GHRP-1 bolus there was a significant (p <0.01) rise in plasma free thyroxine and a decrease of thyrotropin (p <0.01), both in the limits of normal values. There was also a transitory rise of plasma cortisol (p <0.05). Plasma prolactin, luteinizing hormone and follicle-stimulating hormone did not change. It is concluded that GHRP-1 is a potent GH-releasing drug because it acts also when administered orally and has great pharmaceutical and clinical applications.
Effects of bovine growth hormone (GH) expression in transgenic mice on serum and pituitary immunoreactive mouse GH levels and pituitary GH-releasing factor binding sites
Authors: Sotelo AI , Bartke A , Turyn D
Published: June 2009

Pituitary and serum levels of homologous growth hormone (GH) and characteristics of specific GH-releasing factor (GHRF) binding to pituitary homogenates were examined in transgenic mice expressing bovine GH (bGH) gene regulated by different promoters [mouse metallothionein-I (MT) or phosphoenolpyruvate carboxykinase (PEPCK)] and in their normal littermates. Pituitary GH concentration and GHRF binding were reduced by approximately 50% in transgenic MT-bGH mice in which serum bGH levels were about 20 μg/l and by approximately 95% in transgenic PEPCK-bGH mice in which serum bGH levels were tenfold higher. Suppression of plasma immunoreactive mouse GH (mGH) levels was detected in MT-bGH but not in PEPCK-bGH animals, presumably due to cross-reaction of the antiserum employed with bGH. Scatchard plots of GHRF binding to washed homogenates of pituitary glands from normal and young adult MT-bGH transgenic mice were curvilinear, indicating the presence of two types of binding sites, with low and high affinities. Both types of binding sites were reduced in number in MT-bGH transgenic mice without changes in their affinity. In 5–7-month-old MT-bGH transgenic mice there were changes in pituitary GH levels, in GHRF binding levels and in characteristics of GHRF binding that closely resembled the alterations described previously in aging rats. We conclude that over-expression of heterologous GH genes in transgenic mice can lead to partial or virtually complete suppression of somatotroph function, depending on the levels of heterologous GH in the circulation, and that transgenic MT-bGH mice exhibit symptoms of remarkably early onset of neuroendocrine aging.
Efficacy of insulin-like growth factor binding protein 3 in predicting the growth hormone response to provocative testing in children treated with cranial irradiation
Authors: Sklar Charles , Sarafoglou Kyriakie , Whittam Elizabeth
Published: June 2009

Recent data suggest that the plasma concentration of insulin-like growth factor binding protein 3 (IGFBP-3) is useful as a screening test for growth hormone (GH) deficiency. In this study, we measured by radioimmunoassay the levels of IGFBP-3 in a group of 20 subjects (12 males) of 5 years and 7 months to 16 years of age undergoing standard GH testing following cranial irradiation. The patients had received 1800 to > 6000 cGy of radiation to the hypothalamic-pituitary region, a median of 2.7 years (range 2–7 years) prior to testing. The IGFBP-3 concentrations were discordant with the results of GH testing 60% (12/20) of the time. Although IGFBP-3 levels were below the mean for age in 14 of 15 GH-deficient (peak GH <10 μg/l) patients, only three of 15 GH-deficient patients had IGFBP-3 concentrations that fell below age-adjusted norms. In contrast, the IGFBP-3 levels were within the normal range in all five patients with normal GH responses. The low sensitivity (20%) of IGFBP-3 in predicting the subjects with abnormal responses was not improved by adjusting the values for bone age or stage of puberty. We conclude that a single plasma determination of IGFBP-3 is not a useful screening test for GH deficiency among patients previously treated with cranial irradiation.
Regulation of bovine and ovine lymphocyte proliferation by progesterone: modulation by steroid receptor antagonists and physiological status
Authors: Monterroso Victor H , Hansen Peter J
Published: June 2009

Lectin-stimulated sheep and cow lymphocytes were used to test whether inhibitors of classical steroid receptors block suppressive effects of progesterone and whether effects of progesterone vary with physiological status. Neither RU 38486 nor RU 43044 blocked the inhibitory effects of progesterone on lymphocyte proliferation. Rather, these antagonists were themselves inhibitory. Effects of progesterone and antagonists were additive: the percentage inhibition caused by progesterone was similar whether antagonists were present or not. The degree of lymphocyte proliferation and the inhibitory effects of progesterone were of the same magnitude for pregnant/lactating cows, pregnant/non-lactating cows, postpartum/lactating cows and cyclic/non-lactating cows. In conclusion, progesterone does not appear to inhibit lymphocyte proliferation through actions that involve classical steroid receptors. There was no evidence that lymphocyte proliferation in the cow is suppressed during pregnancy or that the inhibitory effects of progesterone increase during pregnancy.
Prolactin stimulates [ 3H]dopamine release from dispersed rat tubero-infundibular dopaminergic neurons and dopamine decreases gonadotropin-releasing hormone release induced by calcium ionophore
Authors: Koike Koji , Kadowaki Kozo , Hirota Kenji , Ohmichi Masahide , Ikegami Hiromasa , Sawada Takeshi , Miyake Akira , Tanizawa Osamu
Published: June 2009

In order to investigate the involvement of prolactin-dopamine and dopamine-gonadotropin interactions in the hypothalamo-pituitary axis of hyperprolactinemia, in vitro studies were performed using primary cultures of dispersed rat hypothalamic heterogeneous cells containing tubero-infundibular dopaminergic neurons or gonadotropin-releasing hormone (GnRH) neurons. We observed that prolactin caused dose-dependent stimulation of [3H]dopamine release after a 16-h incubation. Staurosporin (10 nmol/l), an inhibitor of protein kinase C, significantly reduced the [3H]dopamine release induced by prolactin (1 mg/l). Incubation of tubero-infundibular dopaminergic neurons with prolactin (1 mg/l) had no effect on intracellular cyclic adenosine monophosphate accumulation. Dopamine (1 μmol/l) significantly (p < 0.01) reduced the release of GnRH induced by 50 μmol/l calcium ionophore from dispersed hypothalamic cells from the preoptic area, while prolactin had no effect on GnRH release. These data support the hypothesis that the antigonadotropic effect of prolactin on the hypothalamus is mediated by an inhibitory effect of dopamine on GnRH release.
Activation of the erythropoietin receptor in human skeletal muscle
Authors: Rundqvist Helene , Rullman Eric , Sundberg Carl Johan , Fischer Helene , Eisleitner Katarina , Ståhlberg Marcus , Sundblad Patrik , Jansson Eva , Gustafsson Thomas
Published: June 2009

Objective:Erythropoietin receptor (EPOR) expression in non-hematological tissues has been shown to be activated by locally produced and/or systemically delivered EPO. Improved oxygen homeostasis, a well-established consequence of EPOR activation, is very important for human skeletal muscle performance. In the present study we investigate whether human skeletal muscle fibers and satellite cells express EPOR and if it is activated by exercise.

Design and methods

Ten healthy males performed 65 min of cycle exercise. Biopsies were obtained from the vastus lateralis muscle and femoral arterio-venous differences in EPO concentrations were estimated.

Results

The EPOR protein was localized in areas corresponding to the sarcolemma and capillaries. Laser dissection identified EPOR mRNA expression in muscle fibers. Also, EPOR mRNA and protein were both detected in human skeletal muscle satellite cells. In the initial part of the exercise bout there was a release of EPO from the exercising leg to the circulation, possibly corresponding to an increased bioavailability of EPO. After exercise, EPOR mRNA and EPOR-associated JAK2 phosphorylation were increased.

Conclusions

Interaction with JAK2 is required for EPOR signaling and the increase found in phosphorylation is therefore closely linked to the activation of EPOR. The receptor activation by acute exercise suggests that signaling through EPOR is involved in exercise-induced skeletal muscle adaptation, thus extending the biological role of EPO into the skeletal muscle.
Role of the Pediatrician in Youth Violence Prevention
Authors:   Committee on Injury, Violence, and Poison Prevention
Published: June 2009

This Policy Statement was reaffirmed April 2019.

Youth violence continues to be a serious threat to the health of children and adolescents in the United States. It is crucial that pediatricians clearly define their role and develop the appropriate skills to address this threat effectively. From a clinical perspective, pediatricians should become familiar with Connected Kids: Safe, Strong, Secure, the American Academy of Pediatrics' primary care violence prevention protocol. Using this material, practices can incorporate preventive education, screening for risk, and linkages to community-based counseling and treatment resources. As advocates, pediatricians may bring newly developed information regarding key risk factors such as exposure to firearms, teen dating violence, and bullying to the attention of local and national policy makers. This policy statement refines the developing role of pediatricians in youth violence prevention and emphasizes the importance of this issue in the strategic agenda of the American Academy of Pediatrics.
Physicochemical properties of the soil, and the toxicity of heavy metals to rhizobia infecting pea and Egyptian clover in soil and liquid culture
Authors: Chaudhary P. , Dudeja S.
Published: June 2009

Soil samples were collected from 13 locations in Haryana, after irrigation with sewage water for the past 10–15 years, and were analysed for heavy metals (Cd, Cu, Zn and Ni) and physicochemical properties, such as pH, EC, C, N, and total and available (DTPA-extractable) P. The total heavy metal contents in the soils ranged from 1.3–6.7 mg kg
−1
for Cd, 55.8–353.2 mg kg
−1
for Cu, 356–1028 mg kg
−1
for Zn and 90.0–199.7 mg kg
−1
for Ni. Though soil sample size was small, a significant negative correlation was observed between the organic C and Ni contents in the soil (r
2
= −0.870, P=0.01). The survival of
Rhizobium leguminosarum
bv.
viciae
(strain PRH 1) and
R. leguminosarum
bv.
trifolii
(B 48) tagged with green fluorescent protein (
gfp
) was monitored in liquid culture as well as in the above soil samples. In liquid culture the order of heavy metal toxicity for both strains was Cd>Ni>Cu≥Zn. Soils receiving sewage water showed a 25–97% reduction in the viable cell number of
Rhizobium leguminosarum
strains. Available Cd showed a positive correlation and the other three metals a negative correlation with the reduction in cell numbers in both the strains.
Investigation of factors influencing the regeneration efficiency of Rubus species
Authors: Kálai K. , Csányi M. , Mészáros A. , Balázs E.
Published: June 2009

An efficient regeneration system is described based on the use of several genotypes and combining different cytokinins in the regeneration process. Optimal regeneration efficiency can be obtained if the factors affecting regeneration are examined with special attention to the maintenance of the stock plants, the composition of the medium, and the pre-treatment. The maintenance of stock plants proved to be optimal if the plants were kept on modified LS medium supplemented with 0.125 mg L−16-benzylaminopurine (BAP) and 0.01 mg L−1indole-3-butyric acid (IBA) in large vessels. Pre-treatment was found to increase the regeneration efficiency. Placing the leaves on to medium containing 1.5 mg L−1BAP-riboside and 0.1 mg L−1thidiazuron (TDZ) without wounding, and keeping them in the dark for 6 days gave the best results. The highest regeneration rate was observed on medium containing MS salts with B5 vitamins complemented with 20 g L−1glucose, 3 mg L−1BAP-riboside, 0.2 mg L−1TDZ and 0.2 mg L−1IBA. This system made it possible to achieve regeneration in each of the varieties examined, though to different extents.
Influence of 8-hydroxyquinoline sulphate and sucrose treatments on the post-harvest quality of cut flowers of Strelitzia reginae and Hippeastrum vittatum
Authors: Hassan F.
Published: June 2009

This investigation was carried out to study the effect of 100, 200 and 300 ppm 8-hydroxyquinoline sulphate (8-HQS) and 5 and 10% sucrose treatments on the vase life and post-harvest quality of cut flowers of
Strelitzia reginae
Ait. and
Hippeastrum vittatum
Herb. cv. Apple Blossome. All possible combinations of 8-HQS and sucrose were tested. The treatments were applied as holding solutions, and control flowers were held in distilled water till the end of the experiment. All the treatments significantly increased the vase life and number of open florets of
Strelitzia reginae
cut flowers compared to the control. Applying 8-HQS and sucrose treatments in both seasons improved the vase life and floret longevity of
Hippeastrum vittatum
cut flowers. In addition, the percentage of fresh weight gain from the initial weight and the carbohydrate content were also enhanced in both cut flower crops. In order to obtain the highest post-harvest quality of
Strelitzia reginae
Ait. and
Hippeastrum vittatum
Herb. cv. Apple Blossome cut flowers, treatment with 200 ppm 8-HQS + 10% sucrose was recommended.
Simon Coleman and Peter Collins (eds), Religion, Identity and Change: Perspectives on Global Transformations.
Authors: Cusack Carole M.
Published: June 2009

Simon Coleman and Peter Collins (eds), Religion, Identity and Change: Perspectives on Global Transformations. Ashgate, Aldershot, 2004, pp. xii+214, ISBN 0-7546-0450-0 (hbk).
Michael Washburn, Embodied Spirituality in a Sacred World.
Authors: Keating Ross
Published: June 2009

Michael Washburn, Embodied Spirituality in a Sacred World. State University of New York Press, Albany, 2003, pp. 256, ISBN 100791458474.