Endocrine sequelae after radiotherapy in childhood and adolescence

Radiotherapy may result in endocrine abnormalities, osteoporosis, obesity and neurological sequelae in patients treated for cancer. In the hypothalamo-pituitary area, GH deficiency is the most frequent complication. The frequency, delay of appearance and severity of GH deficiency depend most on the dose delivered during cranial irradiation but variables as age at treatment and fractionation schedule may play an important role as well. Other hypothalamo-pituitary dysfunctions are also dose-dependent. Low dose cranial irradiation may induce precocious or early puberty, while high doses are related to gonadotropin deficiency. Endocrine complications due to extracranial irradiation such as gonadal or thyroid abnormalities are described. In spite of normal GH secretion, linear growth may be impaired by bone lesions secondary to craniospinal or total body irradiation. Results on final height have been optimized by better indicators of GH therapy associated with adequate treatment of early or precocious puberty. The purpose of this review is to explore the late endocrine sequelae of radiotherapy.     

Epidemiology of hepatocellular carcinoma

Year 2000 estimates of the incidence of cancer indicate that primary liver cancer remains the fifth most common malignancy in men and the eighth in women. The number of new cases has been predicted as 564,000, corresponding to 398,000 in men and 166,000 in women. The geographic areas at highest risk are located in Eastern Asia, Middle Africa, and some countries of Western Africa. Changes in incidence among migrant populations underline the predominant role of environmental factors in the etiology of primary liver cancer. In high-risk countries, the early cases of primary liver cancer occur already at ages 20 and above, underlying the impact of viral exposures early in life. In countries at low risk, primary liver cancer is rare before the 50s, translating the impact of late exposures with moderate risks and long latency intervals. Sex ratios are typically between 2 and 4. The incidence of primary liver cancer is increasing in several developed countries including the United States, and the increase will likely continue for several decades. The trend has a dominant cohort effect related to exposures to hepatitis B and C viruses. The variability of primary liver cancer incidence is largely explained by the distribution and the natural history of the hepatitis B and C viruses. The attributable risk estimates for the combined effects of these infections account for well over 80% of liver cancer cases worldwide. Primary liver cancer is the first human cancer largely amenable to prevention using hepatitis B virus vaccines and screening of blood and blood products for hepatitis B and C viruses.     

Gastrointestinal alterations in diabetes mellitus: oxidative stress and blood flow in the superior mesenteric artery--experimental study

BACKGROUND: Gastrointestinal symptoms are frequent in diabetes mellitus and may be related to the oxidative stress, which is defined by an imbalance between the pro-oxidant and antioxidant systems. AIMS: To assess some of the gastrointestinal changes in the diabetes mellitus model, such as the oxidative stress in the stomach and liver of diabetic animals and the blood flow in the superior mesenteric artery at different times of study. MATERIAL AND METHODS: Male Wistar rats weighing 250-350 g were used and ascribed to four different groups as follows: group I--7 days of diabetes, group II--30 days of diabetes, group III--60 days of diabetes, and group IV--90 days of diabetes. Diabetes was obtained by administering streptozotocin (70 mg/kg) intraperitoneally. RESULTS: A significant increase in liver and stomach lipoperoxidation of diabetic animals was found only at 90 days. A significant decrease in the activity of antioxidant enzymes catalase e glutathione transferase was found in stomach, whereas in liver only glutathione transferase was significantly decreased. The blood flow in the superior mesenteric artery of animals with 90 days of diabetes was increased as compared to controls. CONCLUSIONS: It is possible to suppose that the increase in the oxidative stress in stomach and liver as well as the change in the blood flow in the superior mesenteric artery are affected by the length of diabetes and the hyperglycemia found in the animals studied, which would determine gastrointestinal changes.     

Does Cyclophosphamide Play a Protective Role Against Neuronal Loss in Chronic <Emphasis Type="Italic">T.</Emphasis><Emphasis Type="Italic"> cruzi</Emphasis> Infection?

In this study, we verified the possible role of cyclophosphamide (CY) in protecting or not against neuronal losses in young and aged male Calomys callosus chronically infected with the MORC-1 strain of Trypanosoma cruzi through numerical quantification of neurons from the myenteric plexus of the colon and quantification of nitric-oxide concentration (NO) during the acute and chronic phase of infection. For this purpose, groups of young C. callosus were infected with the MORC-1 strain of T. cruzi. A group of infected animals received i.p. 0.2 mg/ml genuxal dissolved in distilled water treatment with CY. NO concentration in aged animals displayed reduced levels when compared to those found in young animals. No significant alterations in the number of neurons were observed in young animals, but for aged ones, a protective role of CY in reducing neuron loss was noted, in addition to enhancing the neuronal volume, area, and perimeter. These results suggest that CY administration, depending on the dose and time span, can act as a protective agent against neuronal losses.