Estradiol and insulin: independent effects on eating and body weight in rats.

The effects of ovariectomy and estradiol replacement were determined in streptozotocin-diabetic female rats maintained on daily injections of protamine zinc insulin. Similar changes in food intake and body weight in these animals and in nondiabetic control animals indicate that the effects of estradiol on these measures are probably not dependent on changes in pancreatic insulin secretion. Acute and chronic insulin challenges in ovariectomized rats maintained on estradiol benzoate, nafoxidine or oil were also examined. The effects of insulin were not attenuated by prior estrogen conditioning, and there was no evidence of insulin resistance. These experiments suggest that the effects of estradiol on body weight and food intake in female rats are not dependent upon altered insulin levels nor attenuation of the effects of insulin. Estradiol may exert its influence on eating and body weight via separate and possibly more direct pathways. The data also are consistent with the suggestion that ovariectomy-induced and hypothalamic obesities are separate phenomena.     

Mild thyroid abnormalities and recurrent spontaneous abortion: diagnostic and therapeutical approach

PROBLEM: The aim of this study is to evaluate the role of mild thyroid abnormalities in recurrent spontaneous abortion, and to assess the effects of two different therapeutical protocols. METHOD: A prospective study in the population of recurrent aborters with mild thyroid abnormalities, evaluating the obstetric outcome in 42 patients. Sixteen thyroid autoantibodies positive patients were treated with thyroid replacement therapy, while 11 patients received intravenous immunoglobulins (IVIG). Fifteen patients, characterized by negative antithyroid antibodies, and having underlying thyroid pathology, were treated with thyroid replacement therapy. RESULTS: Among patients with thyroid antibodies, 6 out of the 11 pregnancies (54.5%) treated with IVIG ended in live birth. In the thyroid supplementation group, 13 out of 16 pregnancies (81.2%) ended in live birth. Only one pregnancy loss occurred among patients with a mild underlying thyroid pathology treated with thyroid replacement therapy. CONCLUSIONS: Mild thyroid abnormalities are associated with an increased rate of miscarriage. This poor obstetrical prognosis seems to be related to an impaired thyroid adaptation to pregnancy. Thyroid replacement therapy appears to be more effective than IVIG in preventing a new miscarriage.     

Reproductive risk factors in unilateral and bilateral renal agenesis

ABSTRACT  Renal agenesis (RA) appears to be a multifactorial condition with combined genetic and environmental influences. We performed a retrospective case-control study of reproductive history of 26 isolated RA live births cases referred to Sicilian Registry of Congenital Malformations. A statistical significant association for birth weight if we considered all RA together and for bilateral RA alone, an increasing risk for maternal age only in the bilateral RA subgroup and a male predominance both for unilateral and bilateral RA was found. Our results show that some reproductive risk factors may be associated with RA, moreover differences found between subgroups indicate that some risk factors may be different in unilateral and bilateral RA. The association between reproductive risk factors and RA may reflect pathogenetic interaction between genetic and environmental factors. Nevertheless further studies are needed to clarify these associations and to explore the role of perinatal factors in the etiology of renal agenesis. In fact if prenatal or perinatal risk factors are in a causal chain influencing the risk for developing RA, then these data could have important implications in the prevention or treatment of this condition.     

A low molecular weight heparin in hemodialysis

Summary The purpose of our study was to check whether the dosage recommended for the low molecular weight heparin tested here, i.e., 50% of the corresponding unfractionated heparin dose, is adequate to prevent clot formation in the extracorporeal system. Sixteen dialysis treatments of 4–5 h were given to each of six chronic dialysis patients. In dialyses 1, 2, 15 and 16 unfractionated heparin (initial dose 35 IU/kg, continuous dose 20 IU/kg/h) was given, and in dialyses 3–14 low molecular weight heparin (initial dose 17.5 anti-Xa U/kg, continuous dose 10 anti-X U/kg/h). At these dose levels of low molecular weight heparin, clot formation occurred in the extracorporeal system in five of the six patients, despite the fact that the plasma anti-Xa level of 0.5 U/ml recommended by the manufacturer had been attained. For this reason the continuous dose of low molecular weight heparin had to be raised to approx. 80% of the corresponding continuous dose of unfractionated heparin. A plasma anti-Xa level of 0.7 U/ml is necessary to prevent extracorporeal clot formation.Abbreviations anti-Xa U Anti-factor Xa unit - aPTT Activated partial thromboplastin time - AT III Antithrombin III - IU International unit - LMWH Low molecular weight heparin - UFH Unfractionated heparin     

Inactivation of the p16 gene by hypermethylation and loss of heterozygosity in adenocarcinoma of the lung

We investigated the aberrant promoter hypermethylation of p16, p15 and p14 genes and loss of heterozygosity (LOH) at 9p21-22 in 48 cases of adenocarcinoma of the lung. The frequencies of hypermethylation of genes were as follows: p16, 25.0%; p15, 22.9%; and p14, 18.8%. The frequency of LOH at chromosome 9p21-22 was 60.9%. The frequency of two-hit inactivation of the p16 gene by hypermethylation and LOH was 21.7%. Two-hit inactivation of the p16 gene showed loss of protein expression and was significantly correlated with tumor size, tumor grade and the Ki-67 labeling index. Hypermethylation of the p16 gene was not significantly correlated with hypermethylation of the p15 and p14 genes, both of which are close to the p16 gene locus, suggesting that hypermethylation of these genes occurs selectivity. In conclusion, biallelic inactivation of the p16 gene by hypermethylation and LOH might cause loss of p16 expression and play an important role in the development of adenocarcinoma of the lung. Therefore, controlling and monitoring for hypermethylation of the p16 gene may be partially useful for treatment and early diagnosis of adenocarcinoma of the lung.     

Effects of thyroxine and temperature manipulations upon the hatching of chick embryos (Gallus domesticus)

Thyroxine levels within chick embryos (Gallus domesticus) and incubation temperature were manipulated late in development in order to determine those events most proximal to the time of hatching that are both necessary and sufficient for the appearance of the hatched state. Events recorded include the time of breathing initiation, changes in breathing rate, time of puncture of the chorioallantoic membrane and changes in rate of loss of yolk sac material. It was found that a certain level of thyroxine is necessary for an animal to hatch, that breathing and puncture of the chorioallantoic membrane are necessary but not sufficient to predict the occurrence of hatching, and that a change in rate of loss of yolk sac material during the last 18 hr prior to hatching is sufficient to predict the occurrence of hatching. The explanatory hypothesis offered is that the endogenous increase in thyroxine levels acting via increased metabolic rates is necessary and sufficient for the animals to hatch.     

Dry heat loss in incubator: comparison of two premature newborn sized manikins

Keeping premature newborns warm is crucial for their survival. Their ability to prevent excessive heat loss to the environment and to control their body temperature is limited. The risk of hypothermia is particularly important for low-birth-weight newborns with a large body surface area in relation to their mass of heat-producing tissues. The present study was performed to assess the body heat loss difference between small and large body-size premature newborns using two anthropomorphic thermal manikins of premature newborns of 900 g and 1,800 g (respective body surface areas of 0.086 and 0.150 m²). The dry heat loss from the six body segments of the small manikin (S) was measured and compared with that of the large manikin (L). The two manikins were exposed to five different environmental temperatures ranging between 29 and 35°C in a single-walled, air-heated closed incubator. The magnitudes of heat loss decreased significantly by 20.4% between the two manikins [small manikin 110.1 (44.3) W/m² vs large manikin 87.6 (25.8) W/m², mean values with one standard deviation]. The results obtained from the comparison of the heat loss measures from the two manikins confirm the fact that the heat loss increases with an increase in the ratio of the body surface area to body mass. The thermal manikin appears to provide an accurate method for the assessment of thermal conditions in neonatal care.     

Radiographic quantification of alveolar bone level changes

The "random burst" theory has recently been proposed as an explanation of the pattern of periodontal disease progression. The theory predicts that the progression of bone loss at individual sites is not dependent upon previous bone loss and age. A longitudinal radiographic study was designed to test this hypothesis, and to describe the changes in bone level over 2 years in a group of 180 subjects (18-68 years of age) who were not under systematic periodontal treatment. The results indicated that 94% of the sites did not show significant changes in the alveolar bone level during the observation period. The mean annual bone loss for the total population was 0.11 mm. By regressing longitudinal bone loss upon age, it was shown that the rate of bone loss increased rapidly between 33 and 56 years of age while a different pattern was shown for the age intervals 18-32 and 57-68 years. Also, the rate of bone loss increased with increasing initial bone loss. This was less evident in the oldest age group. It was concluded that the progression of bone loss in the present material is consistent with a "burst" theory. However, the progression did not occur randomly with regard to previous loss of alveolar bone and time.     

睫状神经营养因子对应激大鼠体质量的影响及其机制探讨

①目的　探讨睫状神经营养因子 (CNTF)对躯体性和心理性应激大鼠体质量的影响及其与下丘脑促肾上腺皮质素释放激素 (CRH)含量的关系。②方法　建立应激大鼠动物模型 ,应用鼠脑立体定向方法 ,在应激前给予大鼠双侧海马微量注射CNTF ,称量大鼠应激前后的体质量变化 ,并用放射免疫分析法测定大鼠下丘脑CRH含量的变化。③结果　在应激前及应激期间给予双侧海马微量注射CNTF ,可以有效改善应激引起的大鼠体质量的下降 (t=2 .16 3.86 ,P <0 .0 5 ,0 .0 1) ,改善应激引起的下丘脑CRH含量的升高 (t=3.0 5 4.0 3,P <0 .0 1)。④结论　CNTF可以改善应激对大鼠生长的损害 ,其机制可能与CNTF降低应激大鼠下丘脑CRH的含量有关。