[Alzheimer disease, memory and estrogen]

Epidemiological studies of Alzheimer disease have shown a higher prevalence of women. Some data argue for a link between Alzheimer disease and the decrease of estrogen in post-menopausal women. Animal studies have shown a beneficial effect of estrogen on memory with a decrease of amyloid deposition in models of AD, whereas estrogen has a positive effect on BDNF. Six studies have shown a positive effect of estrogen therapy on memory and studies on structural and functional imaging have shown a beneficial effect of estrogens but the largest study on prevention of dementia with estrogens (WHI) showed a deleterious effect. To better understand this paradoxical situation, we reviewed the literature on estrogens, memory and Alzheimer disease. We first discuss the promnesic effect of estrogen on mice and rats, second the neuroprotector effect of estrogen on animal models of Alzheimer disease, and third the available human studies. We hypothesize a link with the time of instauration of the estrogen treatment. Nevertheless this hypothesis remains to be demonstrated.

[Maze-like vascular anomaly in partial mole. Interest for the pathological diagnosis of partial mole on chorionic villous sampling]

A case of maze-like angiomatoid anomaly in villi obtained by chorionic villous sampling (CVS) is described. This feature is pathognomonic of partial mole (triploid syndrome) and it was later confirmed by chromosomal analysis. Maze-like angiomatoid anomaly was previously described on specimen submitted after spontaneous or induced abortions, but it was never reported on CVS. This report emphasized that microscopic investigation of CVS cannot be conclusive for cytogenetic anomaly in almost all cases excepted for partial mole where diagnosis criteria are usually characteristic.

Structural and magnetic properties of DyMn(2)D(6) synthesized under high deuterium pressure

DyMn(2)D(6) has been prepared by applying high gaseous deuterium pressure on DyMn(2). This phase is isostructural with other RMn(2)D(6) (R = Y, Er) compounds and crystallizes with a K(2)PtCl(6) type structure having an ordered anion and a partially disordered cation arrangement because Dy and half the Mn atoms are randomly substituted in the same 8c site. The reverse susceptibility follows a Curie-Weiss law with an effective moment of 10 μ(B) similar to that of DyMn(2). Short range magnetic order, corresponding to ferromagnetic correlations, is observed in the neutron patterns up to 10 K and can be attributed to Dy-Dy interactions. The decomposition of the deuteride into Mn and DyD(2), studied by thermal gravimetric analysis, occurs between 470 and 650 K. A further deuterium desorption takes place above 920 K.

Incommensurate spin-density modulation in a copper oxide chain compound with commensurate charge order

Neutron diffraction has been used to determine the magnetic structure of Na8Cu5O10, a stoichiometric compound containing chains based on edge-sharing CuO4 plaquettes. The chains are doped with 2/5 hole per Cu site and exhibit long-range commensurate charge order with an onset well above room temperature. Below TN=23 K, the neutron data indicate long-range collinear magnetic order with a spin-density modulation whose propagation vector is commensurate along, and incommensurate perpendicular to, the chains. Competing interchain exchange interactions are discussed as a possible origin of the incommensurate magnetic order.

Effect of nutrient dilution on feed intake, eating time and performance of hens in early lay

1. An experiment with 480 ISA Brown layers was conducted to measure the effect of dietary energy (11.8, 11.2 and 10.6 MJ/kg) and non-starch polysaccharides (NSP) (128, 146 and 207 g/kg) concentration, soluble NSP content (64 and 85 g/kg), particle size distribution of the NSP fraction (fine and coarse) and feed form (mash and crumble) on feed intake, eating time and egg performance of laying hens in early lay (from 18 to 26 weeks of age). Twelve experimental diets were tested, each replicated 4 times. 2. Laying hens in early lay that were fed low- or high-NSP diets were able to compensate for 10% dietary dilution by 9.5 and 4.9% higher feed intakes, respectively. Feeding crumble or coarsely ground mash did not affect feed intake. 3. Eating time of the hens fed the undiluted diets increased over the experimental period from 16.4 to 24.6% of the observation period, but was not affected by sand or grit addition, particle size distribution or feed form. Feeding high-NSP diets increased eating time by 22%. 4. Egg performance and body weight gain of the hens that were fed low-NSP or high-NSP diets were similar or better compared to the undiluted diets, whereas coarse grinding of the diets showed 7 to 10% lower egg performance and weight gain. Egg performance and weight gain were not affected by feed form. 5. It is concluded that hens in early lay, fed energy-diluted diets, by adding sand or grit (low-NSP) or NSP-rich raw materials (high-NSP) to the control diet, were able to increase their feed intake, resulting in energy intake and egg performance comparable to the control group. Supplementing diets with insoluble NSP also decreased eating rate. Prolonged eating time using insoluble NSP could be useful in reducing feather pecking behaviour.

[Bilateral ductal carcinoma in situ of the breast: independent events or bilateral disease?]

OBJECTIVES

In a retrospective study of bilateral Ductal Carcinoma In Situ (DCIS), cases were analysed to determine the relationship between the two events.

MATERIAL AND METHODS

From 1971 to 2001, among 812 patients with DCIS in Bergonie Institute, 78 suffering from bilateral DCIS and only19 were treated entirely in our institute. It was either synchronous DCIS or asynchronous (before 6 months). We realised a comparative study between, clinical and pathological characteristics of each DCIS.

RESULTS

In case of asynchronous DCIS, contra lateral DCIS occurred after a median 75-months period and until 22 years after the first event. We found at least for one histological subtype an agreement in 53% of cases. In 31% of cases, the grade was the same. For low plus intermediary grade versus high grade, the agreement was 53%. There was a subtype and grade agreement of 32% and a subtype or grade agreement in 63% of cases.

CONCLUSION

Histological agreement between the two lesions indicated the possible existence of in situ bilateral disease in these women. The local relapse rate was 20% and all of them were invasive. The risk of relapse in controlateral breast is high and patient needs a long follow up even in case of mastectomy.

[Synchrotron radiation techniques for structural characterisation of biological entities: an example with renal stone analysis]

This paper describes the opportunities given by the synchrotron radiation techniques regarding the structural characterisation of biological entities. After a short recall on the characteristics of the synchrotron radiation, are described the experimental devices based on fluorescence X, wide angle X-ray scattering and X-ray absorption spectroscopy, which may applied for biological samples, especially in the field of stone analysis. Recent progresses in medical research using synchrotron radiation will be also discussed.

[Actions of a 19-norprogesterone derivative on mammary gland: nomegestrol acetate]

As the biological effects of progestins vary according to their molecular structure, it becomes essential to differentiate the various types of progestins, particularly with regard to the breast.

OBJECTIVE

The purpose of this review was to gather published data on the effects of a 19-norprogesterone derivative, nomegestrol acetate, on the breast. Materials and methods. All experimental and clinical published studies reporting data in the literature on nomegestrol acetate and breast were reviewed.

RESULTS

In experiments on steroid receptors, it was shown that nomegestrol acetate presents a high binding specificity and affinity for progesterone receptors, notably in normal and cancerous human breast tissues. It sharply inhibits synthesis of progesterone receptors in hormone-dependent T-47D human breast cancer cells grown in an estrogenic culture medium, thereby demonstrating its strong progestational activity. On the other hand, it does not bind to estrogen receptors and lacks any estrogenic potential, confirmed by the lack of induction of alkaline phosphatase activity of endometrial Ishikawa cells. Estrogen-induced synthesis of estrogen receptors is also inhibited by nomegestrol acetate, a major determinant of its strong intrinsic anti-estrogenic activity. Unlike androgenic progestins (e.g. 19-nortestosterone derivatives and medroxyprogesterone acetate) which may act indirectly on the breast by inducing modifications of sex hormone binding globulin (SHBG) and insulin-like growth factor-I (IGF-I), nomegestrol acetate is devoid of any androgenic activity. In studies carried out on the effects of progestins on enzyme activities involved in estradiol (E2) formation in breast tissue, nomegestrol acetate can control E2 levels in breast cancer tissue in vitro: it inhibits estrone sulfatase activity that converts estrone sulfate (E1S) to estrone (E1) and inhibits 17beta-hydroxysteroid dehydrogenase type 1 activity that converts E1 to E2, resulting in blockade of E2 bioformation in MCF-7 and T-47D human breast cancer cells. It also stimulates sulfotransferase activity and subsequently the transformation of non conjugated estrogens E1 and E2 into biologically inactive estrogen sulfates. In vitro studies on cell proliferation have demonstrated that nomegestrol acetate, on the one hand, is unable to stimulate proliferation of MCF-7 cells cultured in a medium devoid of estrogens and, on the other hand, can exert antiproliferative effects on T-47D cells grown in an estrogenic environment. Furthermore, studies on mammary apoptosis have shown that the withdrawal of nomegestrol acetate induces apoptosis peak of normal human breast epithelial cells in vitro and in vivo. In clinical trials carried out with premenopausal women, nomegestrol acetate administered in antigonadotropic sequence has demonstrated its efficacy in the treatment of cyclical mastodynia and early onset benign breast diseases. With postmenopausal hormone replacement therapy (HRT) combining estrogen and nomegestrol acetate, clinical trial results showed low incidence of mastodynia while under treatment as well as moderate increase in mammographic density, particularly with continuous combined regimens, however rapidly reversed by a short-term suspension of HRT. Noclinical data with this progestagen is available on breast cancer risk.

CONCLUSION

In addition to efficacy on mastodynia, in vitro and in vivo study results support the good tolerance of nomegestrol acetate on breast, in the short and medium term.

Effect of Rumen-Degradable Protein Balance and Forage Type on Bulk Milk Urea Concentration and Emission of Ammonia from Dairy Cow Houses

As the Dutch government and dairy farming sector have given priority to reducing ammonia emission, the effect of diet on the ammonia emission from dairy cow barns was studied. In addition, the usefulness of milk urea content as an indicator of emission reduction was evaluated. An experiment was carried out with a herd of 55 to 57 Holstein-Friesian dairy cows housed in a naturally ventilated barn with cubicles and a slatted floor. The experiment was designed as a 3 x 3 factorial trial and repeated 3 times. During the experiment, cows were confined to the barn (no grazing) and were fed ensiled forages and additional concentrates. The default forage was grass silage. The nutritional experimental factors were: (1) rumen-degradable protein balance of the ration for lactating cows with 3 levels (0, 500, and 1000 g/cow per d), and (2) proportion of corn silage in the forage ration for lactating cows with 3 levels (0, 50, and 100%) of forage dry matter intake. Several series of dynamic regression models were fitted. One of these models explained emission of ammonia by the nutritional factors and the temperature; another model explained ammonia emission by the bulk milk urea content and the temperature. The ammonia emission from the barn increased when levels of rumen-degradable protein balance increased. Furthermore, at a given level of rumen-degradable protein balance, the emission of ammonia correlated positively with the corn silage content in the forage ration. However, this correlation was not causal, but was the result of interaction between corn silage proportion and intake of ileal digestible protein. The bulk milk urea content and the temperature correlated strongly with the ammonia emission from the barn; the selected model accounted for 76% of the variance in emission. It was concluded that the emission of ammonia from naturally ventilated dairy cow barns was strongly influenced by diet. The emission can be reduced approximately 50% by reducing the rumen-degradable protein balance of the ration from 1000 to 0 g/cow per d. The milk urea content is a good indicator of emission reduction.