Positive assortative mating with family size as a function of predicted parental breeding values.

While other investigations have described benefits of positive assortative mating (PAM) for forest tree breeding, the allocation of resources among mates in these studies was either equal or varied, using schemes corresponding only to parental rank (i.e., more resources invested in higher-ranking parents). In this simulation study, family sizes were proportional to predicted midparent BLUP values. The distribution of midparent BLUP values was standardized by a constant, which was varied to study the range of distributions of family size. Redistributing progenies from lower- to higher-ranking families to a point where an equal number of progenies were still selected out of each family to the next generation caused minimal change in group coancestry and inbreeding in the breeding population (BP), while the additive genetic response and variance in the BP were both greatly enhanced. This generated additional genetic gains for forest plantations by selecting more superior genotypes from the BP (compared to PAM with equal family sizes) for production of improved regeneration materials. These conclusions were verified for a range of heritability under a polygenic model and under a mixed-inheritance model with a QTL contributing to the trait variation.

Open-nucleus breeding strategies compared with population-wide positive assortative mating: II. Unequal distribution of testing effort.

This study compares population-wide positive assortative mating (PAM) with open-nucleus breeding with an elite and main population when more effort is allocated to parents of the elite. A companion study showed that PAM is advantageous when testing effort is independent of parental value. In the present study,unbalanced testing was imposed by varying the number of crosses or the number of genotypes per cross. These unbalanced alternatives are compared with PAM, where the testing effort was varied so that better parents were mated more frequently. More effort allocated to parents of higher rank increased the additive effect and the additive variance and only slightly altered the group coancestry and inbreeding in the breeding population (BP) compared with completely balanced scenarios. Of particular interest to the breeder, large enhancement of the additive variance in the BP contributed to higher gains in the production population (PP). These simulations demonstrate that population-wide PAM leads to higher genetic gains compared with open-nucleus alternatives at any desired target level of diversity in the PP. This is true for both balanced (part I)and unbalanced distribution of testing effort (part II).

Open-nucleus breeding strategies compared with population-wide positive assortative mating: I. Equal distribution of testing efforts.

Positive assortative mating (PAM) can enhance the additive genetic variance in a breeding population(BP). This increases the potential for gains in the production population (PP, selected subset of the BP) for recurrent selection programs in forest trees. The assortment of mates can be either: (1) by individual tree rank across the whole BP (PAM), or (2) trees of similar rank can be merged into larger hierarchical groups and then mated randomly within group ("open"-nucleus breeding,NB). The objective of this study was to compare PAM and NB in quantitative terms. The NB simulation model assumed two tiers (nucleus, main) with unrestricted migration between the tiers. Clonal tests were used to predict breeding values and test resources per mate were kept constant for all mates. Both gain and diversity were combined into a single selection criterion, "group-merit selection." Alternatives were compared over five breeding cycles by considering genetic gain and diversity in a selected PP established in a seed orchard. The assortment of mates in both alternatives enhanced additive variance and increased the additive effect in the BP, leading to additional gain in the PP. Gains generated under PAM always exceeded gains under NB. Thus, the main message from this study is that PAM in both the short- and long-term results in more gain at any target level of diversity in the PP (the breeder's target) than is achieved by the NB alternative. The optimum size of the nucleus varies with the desired level of seed orchard diversity. At lower target diversity, smaller nucleus sizes are favorable, while larger sizes result in more gain when seed orchard diversity is considered more important.

Positive assortative mating with selection restrictions on group coancestry enhances gain while conserving genetic diversity in long-term forest tree breeding.

Selection and mating principles in a closed breeding population (BP) were studied by computer simulation. The BP was advanced, either by random assortment of mates (RAM), or by positive assortative mating (PAM). Selection was done with high precision using clonal testing. Selection considered both genetic gain and gene diversity by "group-merit selection", i.e. selection for breeding value weighted by group coancestry of the selected individuals. A range of weights on group coancestry was applied during selection to vary parent contributions and thereby adjust the balance between gain and diversity. This resulted in a series of scenarios with low to high effective population sizes measured by status effective number. Production populations (PP) were selected only for gain, as a subset of the BP. PAM improved gain in the PP substantially, by increasing the additive variance (i.e. the gain potential) of the BP. This effect was more pronounced under restricted selection when parent contributions to the next generation were more balanced with within-family selection as the extreme, i.e. when a higher status effective number was maintained in the BP. In that case, the additional gain over the BP mean for the clone PP and seed PPs was 32 and 84% higher, respectively, for PAM than for RAM in generation 5. PAM did not reduce gene diversity of the BP but increased inbreeding, and in that way caused a departure from Hardy-Weinberg equilibrium. The effect of inbreeding was eliminated by recombination during the production of seed orchard progeny. Also, for a given level of inbreeding in the seed orchard progeny or in a mixture of genotypes selected for clonal deployment, gain was higher for PAM than for RAM. After including inbreeding depression in the simulation, inbreeding was counteracted by selection, and the enhancement of PAM on production population gain was slightly reduced. In the presence of inbreeding depression the greatest PP gain was achieved at still higher levels of status effective number, i.e. when more gene diversity was conserved in the BP. Thus, the combination of precise selection and PAM resulted in close to maximal short-term PP gain, while conserving maximal gene diversity in the BP.

Antiestrogenic potency of toremifene and tamoxifen in postmenopausal women.

In this nonblinded, controlled multicenter trial, postmenopausal women were randomly assigned to receive graded doses of toremifene and tamoxifen or no antiestrogen to assess dose-response levels and evaluation methodology. For standardization, transdermal estradiol (Estraderm-Ciba Geigy) was applied to all women for 38 days. The antiestrogens were added on days 29-38. For control and all treatment groups, there were no significant changes in serum chemistries or serum hormone levels, nor were there differences in adverse effects. The use of continuous estradiol precluded any meaningful assessment of the estrogenicity of tamoxifen or toremifene. As measured by vaginal superficial cytologic cell count changes, the antiestrogenic activity of toremifene doses ranging from 20 to 200 mg/day could not be distinguished from that of 20 mg/day of tamoxifen, the clinically recommended dose in North America.

Ovarian dysgerminoma: immunocytochemical localization of human chorionic gonadotropin in the germinoma cell cytoplasm.

A case of a pure ovarian dysgerminoma is reported in which the tumor was devoid of syncytiotrophoblastic giant cells, yet it produced human chorionic gonadotropin (hCG). Immunocytochemical studies localized the hCG in the germinoma cell cytoplasm, suggesting that these cells were the site of production.

Cervical adenoid cystic carcinoma associated with ascites.

Two new cases of cervical adenoid cystic carcinoma are reported. The addition of these two cases brings the total number of reported cases in the literature to 88 making this the most common gynecologic site of occurrence for this unusual tumor. Ascites developed in both of these cases after primary radiation therapy. The significance of this unique association is discussed.

Ultrasound screening for free-floating particles and fetal lung maturity.

Ultrasound examination to measure the fetal biparietal diameter (BPD) and examine amniotic fluid for the presence or absence of free-floating particles was performed in 213 patients undergoing amniocenteses for maturity testing at term. A modified lecithin to sphingomyelin ratio (L/S) was performed on all samples. A BPD greater than or equal to 92 mm predicted 37 of 111 (33%) mature L/S ratios of nondiabetic pregnancies. The presence of free-floating particles predicted 48 of 138 (35%) mature L/S ratios of nondiabetics. Combined, a BPD greater than or equal to 92 mm and/or the presence of free-floating particles predicted 57 of 110 (52%) mature L/S ratios of nondiabetics. It is concluded that a BPD greater than or equal to 92 mm and the presence of free-floating particles are independent yet complimentary predictors of fetal lung maturity.

Cholecystoenteric anastomosis with the EEA stapler for cancer of the pancreas.

The integrity of a stapled anastomosis of the small bowel to the gallbladder with malignant distal biliary obstruction was investigated. Seven dogs were studied during a 52 week period following completion of a cholecystoenterostomy (Roux-Y) with an EEA stapler for bypass of a ligated common bile duct. A widely patent and secure anastomotic line was documented. Three human patients with unresectable cancer of the head of the pancreas who underwent stapled cholecystojejunostomies received excellent palliation as well. Cholecystojejunostomy with the EEA stapler is a rapid and safe procedure for unresectable, malignant distal biliary obstruction.

Substrate composition and sepsis. Effects on immunity.

A randomized prospective study was performed to determine the effects of substrate composition on immunity in septic malnourished patients. A balanced substrate formula was administered to 11 patients with sepsis and 11 nonseptic patients. This provided 40 kcal/kg/day and 1 to 1.5 g of protein per kilogram each day with a carbohydrate-nitrogen ratio of 50:1. A 25% dextrose and 4.25% protein solution that provided 50 kcal/kg/day and 1 to 1.5 g of protein per kilogram each day with a carbohydrate-nitrogen ratio of 150:1 was provided to ten patients with sepsis and 11 without. Skin test conversion rates were not affected by substrate composition; however, the absolute lymphocyte count was significantly improved in septic patients who achieved positive nitrogen balance, regardless of the nutritional support regimen used. These findings suggest that substrate composition per se has no effect on immunologic responsiveness.

The effect of nutritional support on immune competency in patients suffering from trauma, sepsis, or malignant disease.

Thirty-nine patients, 25 of whom were suffering from trauma, sepsis, or malignant disease, were studied prospectively to determine the immunologic value of improved protein-calorie balance in this setting. All were suffering from varying degrees of malnutrition, and 72% (P less than 0.05) of the patients with anergy-inducing disease processes were anergic at the time of evaluation. In the presence of disease-induced anergy, skin test reactivity was not helpful in measuring the therapeutic response to nutritional support; among severely wasted patients, significant elevations in absolute lymphocyte count and serum albumin suggest that these are useful parameters when following the severely wasted patient who has concomitant trauma, sepsis, or malignant disease.