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At least 523 records · Page 29Linked to original sources
PubMed2000

Inhibitory effects of WR-2721 and cysteamine on tumor initiation in mammary glands of pregnant rats by radiation.

We evaluated the effect of WR-2721 [S-2-(3-aminopropylamino)-ethylphosphorothioic acid] and cysteamine (2-mercaptoethylamine) on the development of radiation-induced mammary tumors in rats. Pregnant rats were treated with WR-2721 or cysteamine 30 min prior to whole-body irradiation with gamma rays from a (60)Co source at a dose of 1.5 or 2.6 Gy. Additional pregnant rats were given saline and then exposed to gamma rays at a dose of 0, 1.5 or 2.6 Gy as a control. All rats were implanted with pellets of diethylstilbestrol, a tumor promoter, 1 month after termination of nursing and were observed for 1 year to detect palpable mammary tumors. No mammary tumors developed in the saline-injected nonirradiated rats. However, when rats were irradiated with 1.5 or 2. 6 Gy after saline treatment, the incidence of mammary tumors was high (71.4 and 92.3%, respectively). Administration of WR-2721 or cysteamine prior to irradiation with 1.5 Gy significantly decreased the tumor incidence (23.8 and 20.8%, respectively). Tumor prevention by either agent was less effective at the higher dose. The appearance of the first mammary tumor occurred later in rats treated with WR-2721 or cysteamine than in the control rats. An increasing rate of adenocarcinoma in the control group was observed with increasing dose from 1.5 Gy up to 2.6 Gy. However, the development of adenocarcinoma did not increase after pretreatment with WR-2721 or cysteamine in rats irradiated with 2.6 Gy. Many of the mammary tumors that developed in the control rats were of the ER(+)PgR(+) type. Administration of WR-2721 produced no tumors of the ER(+)PgR(+) type. Cysteamine treatment increased the development of ER-negative tumors. The serum concentration of progesterone was significantly higher in rats treated with WR-2721 or cysteamine than in the control rats. On the other hand, the estradiol-17beta concentration was reduced by treatment with WR-2721, but not significantly compared to the control. WR-2721 and cysteamine had no effect on the prolactin concentration of the irradiated rats. The results suggest that administration of WR-2721 or cysteamine prior to the irradiation has a potent preventive effect on theinitiation phase during mammary tumorigenesis.

Adenocarcinoma↗
PubMed1982

Effect of hypothalamic and pituitary irradiation on pubertal development in children with cranial tumors.

The purpose of the present study was to report on gonadotropin function and puberty of a large group of children treated by cranial irradiation for cranial and neck tumors and medulloblastoma. Forty-five children of pubertal age were investigated. The mean interval time since radiation was 5 2/12 yr. Gonadotropin and gonadal function were evaluated by clinical criteria, plasma sex steroids, and plasma LH and FSH responses to LRH. Puberty was complete or progressing normally in 31 cases and was abnormal in 14 cases. Severe gonadotropin deficiency, with lack of or slow progression of puberty and decreased LH and FSH responsiveness to LRH, was observed in 5 cases; 2 of these had moderately elevated plasma PRL levels. Secondary amenorrhea or lack of pubertal progression was found in 5 other cases. GH deficiency was associated with gonadotropin deficiency in 9 of these 10 cases. Adrenal function, estimated by basal dehydroisoepiandrosterone, dehydroisoepiandrosterone sulfate, and estrone, was normal according to pubic hair stages. In conclusion, complete or partial gonadotropin deficiency can be the consequence of cranial irradiation in children receiving 6000 rads or less. It is usually associated with GH deficiency. The site of the damage on the pituitary gland or the hypothalamus remains to be demonstrated.

Adolescent↗
PubMed1993

Endocrine function following single fraction and fractionated total body irradiation for bone marrow transplantation in childhood.

Forty-nine children who had undergone treatment with cyclophosphamide and total body irradiation before bone marrow transplantation were investigated for impaired endocrine function. Twenty-six patients received single fraction total body irradiation as a dose of 9-10 Gy, whereas 23 patients received fractionated total body irradiation as a total dose of either 12 Gy divided into six fractions or 14.4 Gy divided into eight fractions, administered over 3 or 4 days. Half of the patients in the single fraction group and nine in the fractionated group had received cranial irradiation prior to total body irradiation. Pathological changes in thyroid function were observed in 19 patients (73%) of the single fraction group (elevated thyrotrophin (58%) and decreased thyroxine levels (15%)), whereas in the fractionated group only six patients (25%) developed transient raised thyrotrophin levels: the mean observation period was 3.2 years in the single fraction group and 2.7 years in the fractionated group. The stimulated growth hormone peak concentration was influenced significantly by previous cranial irradiation and was independent of the type of total body irradiation administered. In the patients who had received cranial irradiation, the mean growth hormone peak levels were 8.4 mU/l (single fraction group) and 13.9 mU/l (fractionated group), whereas in those who received only total body irradiation they were 24.9 mU/l(single fraction group) and 28.1 mU/l (fractionated group). The basal gonadotrophin concentration in children older than 9 years showed elevated levels in nine patients (50%) of the single fraction group and in only three patients (30%) of the fractionated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1984

Hyperadrenalism in childhood and adolescence.

Hyperadrenalism in childhood and adolescence has unique features that influence diagnosis and management. We reviewed our experience with 18 patients, ranging in age from 18 months to 18 years. Nine had bilateral adrenal hyperplasia, eight had adrenal neoplasms, and one had micronodular hyperplasia. Patients with congenital adrenal hyperplasia and hyperaldosteronism were excluded. Six patients with Cushing's disease diagnosed in earlier years were treated by total adrenalectomy and recently two patients underwent transsphenoidal removal of pituitary tumors. Bilateral adrenalectomy was carried out in one patient with micronodular hyperplasia and in a second because of elevated adrenocorticotrophic hormone (ACTH) levels from an undefined source. Eight patients had adrenal neoplasms, including five adenomas and three carcinomas. We found no reliable criteria to differentiate before surgery between adrenal adenomas and adrenal carcinomas. The most recognizable characteristic of malignancy was tumor size, specifically weight greater than 75 gms. Of the three patients with adrenal carcinoma, one expired 20 months after adrenalectomy and 8 months after receiving palliative partial hepatectomy for liver metastasis. Two patients are well with normal growth and development at 11 and 20 years following adrenalectomy. With the exception of one patient who died 6 years after surgery from a glioblastoma multiforme, all patients with adrenal adenomas are well. Eight patients underwent bilateral adrenalectomy for hypercortisolism. Five of the six who have reached their adult stature are significantly stunted. Four of six patients with Cushing's disease, treated by total adrenalectomy, have developed Nelson's syndrome at 2, 6, 10, and 12 years after surgery. Of the two patients undergoing transsphenoidal surgery, one had recurrent disease at 2 years and was treated by pituitary irradiation with recovery. The patients undergoing adrenalectomy for micronodular hyperplasia and ectopic ACTH are well at 2 and 4 years, respectively. Cushing's disease in children and adolescents is best treated by transsphenoidal removal of the pituitary adenoma. Adrenalectomy, once the most accepted approach, plays a secondary role and is indicated primarily in micronodular adrenal hyperplasia, in patients with ectopic ACTH production of an undefined source, and in recurrent Cushing's disease following prior pituitary irradiation. The high incidence of Nelson's syndrome in children treated by adrenalectomy mandates that patients at risk be monitored lifelong for the progression of a pituitary tumor.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenoma↗
PubMed1995

Role of busulfan and total body irradiation on growth of prepubertal children receiving bone marrow transplantation and results of treatment with recombinant human growth hormone.

Seventy-six prepubertal children receiving autologous or allogeneic bone marrow transplantation (BMT) were enrolled in a prospective study on the impact of different pretransplant preparative regimens on growth. Patients were divided into three groups: group I, consisting of 37 children who had received total body irradiation (TBI) and cytotoxic drugs as preparative regimen; group II, including 17 children receiving prophylactic cranial irradiation before being conditioned with TBI and cytotoxic drugs; and group III, composed of 22 patients transplanted after a busulfan (BU)-containing myeloablative therapy. All patients have a minimum follow-up of 2 years, whereas 48 and 34 patients have been studied until 3 and 4 years after transplant, respectively. Height and growth rate were expressed as standard deviation score (SDS). Growth hormone (GH) secretion in response to pharmacologic stimuli was evaluated after documented growth failure. Patients with GH deficiency were treated with recombinant human GH, and response to therapy was evaluated. The main impairment of growth rate in patients belonging to group II was observed in the first year after TBI (growth rate SDS changing from -0.12 +/- 0.23 to -1.23 +/- 0.25, P < .005), with only a slight loss in the following years, whereas in group I children growth failure occurred in the third year after TBI (-1.36 +/- 0.28 SDS in comparison to a pre-BMT SDS of 0.10 +/- 0.15, P < .005). Therefore, growth velocity between these two groups differed significantly in the first 2 years (P < .01) but subsequently equalized. On the contrary, all BU-treated children but 2 grew normally. GH deficiency was shown in the vast majority of children with growth impairment. Twenty-three children treated with recombinant human GH are evaluable; a successful response was observed in all but 1, with the mean growth rate increasing from -2.29 +/- 0.27 before treatment to 0.86 +/- 0.38 and to 1.66 +/- 0.56 SDS at 1 and 2 years after treatment, respectively (P < .001). In conclusion, growth rate impairment was common in patients receiving TBI, with the speed of onset of both decreased growth velocity and GH deficiency depending mainly on the total dose of radiation. On the contrary, patients receiving BU did not experience significant problems in terms of growth velocity. The timely start of appropriate hormonal replacement therapy may ameliorate the final growth of children undergoing BMT.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2003

The usefulness of the combined growth hormone (GH)-releasing hormone and arginine stimulation test in the diagnosis of radiation-induced GH deficiency is dependent on the post-irradiation time interval.

The diagnostic usefulness of the insulin tolerance test (ITT) in patients with radiation-induced GH deficiency (GHD) is well established, whereas that of the combined GHRH plus arginine stimulation test (AST) is unproven. Both tests were undertaken in 49 adult survivors (aged 16-53.7 yr), who were previously irradiated for non-pituitary brain tumors or leukemia, and 33 age-, gender-, and BMI-matched controls. The aims of the study were to examine the impact of the time interval after irradiation on the pattern of GH responsiveness to the two provocative tests and to establish the role of the GHRH + AST in the diagnosis of radiation-induced GHD. The median (range) peak GH responses to either test were significantly lower (P < 0.0001) in the patients [GHRH + AST, 19.9 (range, 2.7-103.5) microg/liter; ITT, 5 (0.2-34.8) microg/liter] than in normals [GHRH + AST, 55 (5.7-173.5) microg/liter; ITT, 23.8 (4.2-80) microg/liter]. In patients and normal controls, the median peak GH response to the GHRH + AST was significantly greater (P < 0.0001) than the response to the ITT. However, the ratio of the peak GH response to the GHRH + AST over that achieved with the ITT (discordancy ratio) was significantly higher (P = 0.007) in the patients (median, 3.45; range, 0.8-53.5) compared with normals (median, 2; range, 0.34-18.6), consistent with dominant hypothalamic damage and relatively preserved somatotroph responsiveness. The peak GH response to the ITT fell significantly within 5 yr of irradiation with little further change over the subsequent 10 yr. In contrast, the peak GH response to the GHRH + AST barely changed within 5 yr of irradiation but subsequently declined significantly over the next 10 yr. Thus, the evolution of change in GH responsiveness to the two different stimuli over time was markedly different, resulting in a significantly raised discordancy ratio of 6 within the first 5 postirradiation years, which then normalized over the next 10 yr. The peak GH responses to the GHRH + AST and the discordancy ratio were negatively correlated with the time interval after irradiation (r = -0.40, P = 0.0037; and r = -0.4, P = 0.0046, respectively). On a practical clinical level, the discordancy between the GH test results was important; 50% of those classified as severely GHD patients by the ITT were judged normal or only GH insufficient by the GHRH + AST. In conclusion, these findings suggest that hypothalamic dysfunction occurs early and somatotroph dysfunction occurs late, following radiation damage to the hypothalamic-pituitary axis. This time dependency of somatotroph dysfunction may reflect either secondary somatotroph atrophy due to hypothalamic GHRH deficiency or delayed direct radiation-induced damage to the pituitary gland. The high false negative diagnosis rate for severe GHD makes the GHRH + AST an unreliable test in clinical practice when GH status is explored in the early years after cranial irradiation with the intention to treat.

Adolescent↗