Genetic diversity and population structure of castor (Ricinus communis L.) germplasm within the US collection assessed with EST-SSR markers

Castor is an important oilseed crop and although its oil is inedible, it has multiple industrial and pharmaceutical applications. The entire US castor germplasm collection was previously screened for oil content and fatty acid composition, but its genetic diversity and population structure has not been determined. Based on the screening results of oil content, fatty acid composition, and country origins, 574 accessions were selected and genotyped with 22 polymorphic EST-SSR markers. The results from cluster analysis, population structure, and principal component analysis were consistent, and partitioned accessions into four subpopulations. Although there were certain levels of admixtures among groups, these clusters and subpopulations aligned with geographic origins. Both divergent and redundant accessions were identified in this study. The US castor germplasm collection encompasses a moderately high level of genetic diversity (pairwise dissimilarity coefficient = 0.53). The results obtained here will be useful for choosing accessions as parents to make crosses in breeding programs and prioritizing accessions for regeneration to improve germplasm management. A subset of 230 accessions was selected and will be planted in the field for establishing a core collection of the US castor germplasm. Further evaluation of the US castor germplasm collection is also discussed.

Clinical genetics of familial keloids

BACKGROUND

Keloids are proliferative fibrous growths that result from an excessive tissue response to skin trauma. Most keloids occur sporadically, but some cases are familial. However, the genetics of keloid formation have only rarely been documented, and the mode of inheritance is not known.

OBJECTIVE

To elucidate the clinical genetic characteristics of keloid wound-healing disorder.

OBSERVATIONS

We studied the clinical and genetic characteristics of 14 pedigrees with familial keloids. The ethnicity of these families is mostly African American (n = 10), but also white (n = 1), Japanese (n = 2), and African Caribbean (n = 1). The pedigrees account for 341 family members, of whom 96 displayed keloids. Of the affected family members, 36 are male and 60 are female. The age of onset varies from early childhood to late adulthood. There is variable expression of keloids within the same families: some affected members have only minor earlobe keloids, whereas others have very severe keloids affecting large areas of the body. In the described pedigrees, 7 individuals are obligate unaffected carriers, revealing nonpenetrance in about 6.8% of keloid gene carriers. Syndromes associated with keloids, namely Rubinstein-Taybi and Goeminne syndrome, were not found in these families. Additionally, linkage to the gene loci of these syndromes and X-chromosomal linkage were excluded.

CONCLUSIONS

The pattern of inheritance observed in these families is consistent with an autosomal dominant mode with incomplete clinical penetrance and variable expression. This is the most comprehensive collection of keloid families described to date, and it allows for the first time the elucidation of the clinical genetic characteristics of the familial form of this wound-healing disorder.

Adult generativity and the socialization of adolescents: relations to mothers' and fathers' parenting beliefs, styles, and practices

Mothers, fathers, and their adolescent children participated in two studies investigating the relations between Erikson's concept of generativityin adulthood and patterns of parenting. Study 1 involved 77 mothers and 48 fathers of 1st-year university students; Study 2 was part of an investigation of socialization processes in 35 families with an adolescent, aged 14-18. Parental generative concern was assessed by the Loyola Generativity Scale (LGS) of McAdams and de St. Aubin (1992) in each study. In both studies, mothers demonstrated positive relations between scores on the LGS and an authoritative style of parenting, as well as between generativity and more positive, optimistic views of adolescent development. In Study 2, these more positive views in turn mediated some aspects of autonomy-fostering practices used with the adolescent. Variations in fathers' levels of generative concern were less consistently related to these indices of parenting, however.

Detection of Lead in the Carbon-rich, Very Metal-poor Star LP 625-44: A Strong Constraint on s-Process Nucleosynthesis at Low Metallicity

We report the detection of the Pb i lambda4057.8 line in the very metal-poor (&sqbl0;Fe&solm0;H&sqbr0;=-2.7), carbon-rich star, LP 625-44. We determine the abundance of Pb (&sqbl0;Pb&solm0;Fe&sqbr0;=2.65) and 15 other neutron-capture elements. The abundance pattern between Ba and Pb agrees well with a scaled solar system s-process component, while the lighter elements (Sr-Zr) are less abundant than Ba. The enhancement of s-process elements is interpreted as a result of mass transfer in a binary system from a previous asymptotic giant branch (AGB) companion, an interpretation strongly supported by radial velocity variations of this system. The detection of Pb makes it possible, for the first time, to compare model predictions of s-process nucleosynthesis in AGB stars with observations of elements between Sr and Pb. The Pb abundance is significantly lower than the prediction of recent models (e.g., Gallino et al.), which succeeded in explaining the metallicity dependence of the abundance ratios of light s-elements (Sr-Zr) to heavy ones (Ba-Dy) found in previously observed s-process-enhanced stars. This suggests that one should either (1) reconsider the underlying assumptions concerning the (13)C-rich s-processing site ((13)C pocket) in the present models or (2) investigate alternative sites of s-process nucleosynthesis in very metal-poor AGB stars.

Primordial Lithium and Big Bang Nucleosynthesis

Recent determinations of the abundance of the light-element Li in very metal-poor stars show that its intrinsic dispersion is essentially zero and that the random error in the estimated mean Li abundance is negligible. However, a decreasing trend in the Li abundance toward lower metallicity indicates that the primordial abundance of Li can be inferred only after allowing for nucleosynthesis processes that must have been in operation in the early history of the Galaxy. We show that the observed Li versus Fe trend provides a strong discriminant between alternative models for Galactic chemical evolution of the light elements at early epochs. We critically assess current systematic uncertainties and determine the primordial Li abundance within new, much tighter limits: &parl0;Li&solm0;H&parr0;p=1.23+0.68-0.32x10-10. We show that the Li constraint on OmegaB is now limited as much by uncertainties in the nuclear cross sections used in big bang nucleosynthesis (BBN) calculations as by the observed abundance itself. A clearer understanding of systematics allows us to sharpen the comparison with 4He and deuterium and the resulting test of BBN.

Generativity and moral development as predictors of value-socialization narratives for young persons across the adult life span: from lessons learned to stories shared

Little research so far has examined storytelling as a channel of value socialization. In the present study, 129 adults from 3 age groups (18-26, 28-50, 60-75) were asked to tell stories for adolescents about 2 of their past value-learning experiences. Generative concern (D. P. McAdams & E. de St. Aubin, 1992) and moral reasoning stage level were also assessed. Stronger generative concern was predictive of a greater sense of having learned important lessons from these past events, of stronger adult value socialization investment, and of more engaging narratives for adolescents as judged by a panel of uninstructed raters. Higher levels of moral reasoning were positively related to generative concern and to a stronger sense of past lessons learned. Generativity appears important to the project of value socialization across the adult life span.

Generativity and moral development as predictors of value-socialization narratives for young persons across the adult life span: from lessons learned to stories shared

Little research so far has examined storytelling as a channel of value socialization. In the present study, 129 adults from 3 age groups (18-26, 28-50, 60-75) were asked to tell stories for adolescents about 2 of their past value-learning experiences. Generative concern (D. P. McAdams & E. de St. Aubin, 1992) and moral reasoning stage level were also assessed. Stronger generative concern was predictive of a greater sense of having learned important lessons from these past events, of stronger adult value socialization investment, and of more engaging narratives for adolescents as judged by a panel of uninstructed raters. Higher levels of moral reasoning were positively related to generative concern and to a stronger sense of past lessons learned. Generativity appears important to the project of value socialization across the adult life span.

Acute excisional wounds treated with a tissue-engineered skin (Apligraf)

BACKGROUND

Tissue-engineered products are usually composed of living cells and their supporting matrices that have been grown in vitro, using a combination of engineering and life sciences principles. Apligraf is a bilayered product composed of neonatal-derived dermal fibroblasts and keratinocytes, and Type I bovine collagen.

OBJECTIVE

To evaluate in a prospective, multicentered open study, the effects of tissue therapy with a tissue-engineered skin (Apligraf) with partial or full-thickness excisional wounds.

METHODS

One hundred and seven patients participated in this study. The tissue-engineered skin was applied once, immediately after excisional surgery, usually for skin cancer, and patients were followed for up to one year.

RESULTS

The safety results were impressive, with no clinical or laboratory evidence of rejection. Clinically, graft persistence was good to excellent in 77 of 105 (73.3%) of patients at one week, falling to 56.6% and 53.6% at two weeks and one month respectively.

CONCLUSION

To date, this is the largest experience with a tissue-engineered skin product in acute wounds, and this study suggests that tissue therapy may be safe and useful.

Superficial x-ray therapy in keloid management: a retrospective study of 24 cases and literature review

Radiotherapy for the management of keloids was introduced in 1906. Eighty-eight years later there is no consensus among physicians who treat keloids that radiotherapy is safe, although it is generally accepted that radiotherapy is effective in reducing the recurrence of keloids following excision. This paper reports on a retrospective study of 24 patients whose keloid postexcisional sites were treated with superficial x-ray therapy. This paper compares the author's results with the results of 18 studies reported by other investigators. The objective of the paper was to determine the effectiveness and safety of superficial x-ray therapy. The paper concludes that superficial x-ray therapy does reduce the rate of postexcisional keloid recurrence. It stresses the need for better controls in reporting on superficial x-ray therapy in keloid management. A multi-institutional prospective study is proposed, and a suggested protocol is outlined. There has been only one case report of a carcinoma occurring subsequent to the treatment of a keloid postexcisional site with radiotherapy, and the causal relation was questionable. A system for long-term follow-up of patients who receive superficial x-ray therapy is proposed.

Basal cell carcinoma in blacks: a report of 15 cases

We report 15 cases of basal cell carcinoma (BCC) in black patients seen in an office practice over a 15-year period. Review of the literature supports our view that nonmelanoma skin cancer in blacks is more prevalent than generally thought. The major etiological factor in BCC development is exposure to ultraviolet light. Skin pigmentation, however, provides some degree of protection. We suggest that BCC development in blacks and in nonexposed areas in whites may represent a different pathogenesis from BCC caused by ultraviolet light exposure.

The effect of carbon dioxide laser surgery on the recurrence of keloids

The efficacy of carbon dioxide laser excision as a primary modality for the treatment of keloids was evaluated. This retrospective study focuses on 31 patients with one or more keloids, 23 of whom were available for follow-up after carbon dioxide laser excision. The patients' ages ranged from 5 to 72 years. There were 16 females and 7 males. One patient was Caucasian, 22 patients were non-Caucasian, and there were no Asians. The keloids that were excised ranged in size from 1 to 30 cm in greatest diameter. One patient had no recurrence of her keloid after carbon dioxide laser excision, 9 patients required steroids to suppress recurrences, and 13 patients were considered failures. Reasons for the failure of this modality, as well as speculation regarding the future of this procedure, are discussed.

Cosmetic and reconstructive breast surgery in blacks

Black women have not embraced cosmetic and reconstructive surgery of the breast with the same enthusiasm as their Caucasian counterparts because of fear of hypertrophic scars. The authors offer suggestions on how to minimize the scarring associated with breast surgery in black women. They feel that intraareolar incisions should be used whenever circumareolar incisions are indicated in augmentation mammaplasty, because the areola, being a favored area, is less likely to produce hypertrophic scars. The Marchac technique of reduction mammaplasty is recommended because it produces a short horizontal scar of 5 to 8 cm confined to the breast without medial and lateral extension, which may hypertrophy in black women. In the reduction of large breasts, secondary excision of dogears 6 or more weeks after mammaplasty reduces the medial and lateral extents of the scar. The use of liposuction as an adjunct to reduction mammaplasty may also accomplish the same thing. Amputation and free nipple-areola grafting should be used with caution in black patients because of the tendency of the grafted areola to hypopigment. In postmastectomy reconstruction, the authors suggest that the techniques described by Ryan and Radovan should be considered first before the techniques of reconstruction utilizing myocutaneous flaps. In these procedures, no new scars which may hypertrophy are created away from the site of reconstruction. Staples should not be used in skin closure in blacks because they cause cross-hatching of the wound even when removed early.

Reconstruction of half of the face

A 29-year-old man underwent a severe electrical burn involving the entire right side of the face, resulting in destruction of the temple, orbit, a portion of the nose, zygoma, and maxilla, through-and-through destruction of the cheek and lips, and a portion of the parotid gland and buccal mucosa. This massive and debilitating wound was an acute surgical emergency, as far as life-support measures were concerned. Gradually, the patient underwent débridement, and finally resurfacing of the entire right side of the face with a large deltopectoral flap. Over four years, this flap, the area of the orbit, and the area of the lips underwent rehabilitation and the transportation of residual regional muscles, and the debulking and repositioning of the flap was carried out. The orbit was finally rehabilitated with a prosthesis.

Responses of canine endocardium to stimulation of the upper thoracic roots

In each of 10 mongrel dogs anesthetized with alpha chloralose, strain-gauge arches were sutured to five epicardial and three endocardial locations. Comparisons of contractile force responses during stimulation of the left and right roots of the same segmental level revealed several differences dependent upon the particular myocardial area observed. Of the three left ventricular endocardial areas studied, the interventricular septum was the most responsive, particularly during stimulation of the right roots. The basal free wall and posterior papillary muscle were more responsive to left-root than to right-root stimulations. Epicardial responses were consistent with those previously reported. Generally, all areas responded to the greatest degree during stimulation of the second roots with the third and first next in order of effectiveness. Although stimulation of each level of preganglionic outflow activated all epicardial and endocardial segments of the myocardium, the magnitude of the changes in contractile force were highly variable dependent upon the specific level of preganglionic outflow and the location of the strain-gauge arch.

Responses of the canine myocardium to stimulation of thoracic cardiac nerves

The thoracic cardiac nerves were stimulated in each of 21 dogs anesthetized with alpha chloralose. Recordings were made of heart rate, blood pressure, and contractile force from all four cardiac chambers. Walton-Brodie strain-gauge arches were sutured to both atria, and to three locations of each ventricle, representing both anterior and posterior surfaces. The functional autonomic components of each nerve were summarized and classified into four basic types. Types I and II were both located medial to the thoracic vagi. These were shown to contain both sympathetic and parasympathetic components traveling to all four chambers of the heart. The sympathetic componnent of the type II nerves produced reflex changes in force of contraction and systemic blood pressure. Nerves classified as types III and IV produced no parasympathetic effect on the heart. These were all located lateral to the thoracic vagi. While the type III nerves carried sympathetic efferent fibers to all four chambers, the type IV nerve carried sympathetic fibers predominantly to the right atrium.