Sexual selection promotes hybridization between Pecos pupfish, Cyprinodon pecosensis and sheepshead minnow, C. variegatus.

Rapid and extensive genetic introgression has occurred between Pecos pupfish (Cyprinodon pecosensis) and sheepshead minnow (Cyprinodon variegatus) in the wild. We studied both female mate choice and male-male competition for mates among C. pecosensis, C. variegatus, and their F1 hybrids to determine what role these behaviours played in the formation of the hybrid swarm. Female C. pecosensis preferred male C. variegatus to conspecific males, C. variegatus females displayed no significant preference when given a choice between purebred males, and neither C. pecosensis nor C. variegatus females discriminated against F1 hybrid males. We found no evidence for female olfactory recognition of mates. Male F1 hybrids and C. variegatus were more aggressive than C. pecosensis males, achieving greater reproductive success under two different experimentally-induced mating systems. Hybrids were superior to C. variegatus when only two males competed (dominance interactions), but the two types were competitively equivalent in a territorial mating system. Our results indicate that active inter- and intra-sexual selection contributed to the accelerated hybridization between these two species. By including the possibility that some aspects of a hybridization and introgression event may be under positive selection, researchers may better understand the dynamics that lead to hybrid zone stability or the spread of introgressed genetic material.

Culture and physician-patient communication: a qualitative exploration of residents' experiences and attitudes.

BACKGROUND: Increasing evidence suggests that communication plays a central role in effective clinical care. To facilitate effective instruction in this domain, this study seeks to understand how pediatric residents approach the challenge of cross-cultural communication. METHODS: A convenience sample of 29 pediatric residents participated in five focus groups that were jointly facilitated by a clinical and a process expert. Discussion was stimulated using two video scenarios of pediatric cross-cultural communication challenges. RESULTS: Seven dominant categories were evident in the discussions: characteristics of culture, beliefs about culture, attitudes towards culture, opinions about how to build expertise in communication, cultural conflict, insights regarding prejudice, and comments about interview technique. Residents tended to view culture and difference as residing in patients (not in themselves), reflecting their assumption that western medicine is acultural. CONCLUSIONS: Residents believe that lack of knowledge about other cultures causes their communication difficulties. Our findings suggest, however, that more basic issues may underlie their difficulties. Residents may recognize prejudice in the abstract but fail to see it in their environment, and they may spend minimal time reflecting on their professional culture and beliefs.

Peripheral nerve injuries and repair in the upper extremity.

Peripheral nerve injuries are commonly seen as a result of domestic, industrial, or military trauma. Sharp objects usually cause these nerve injuries. When assessing these injuries, it is important to evaluate each nerves' motor and sensory function. One must be cognizant of associated injuries such as fractures, vascular damage, and musculotendinous lacerations. The time since the injury, level of injury, and age of the patient are important prognosticators impacting the return of function. Intraoperatively, one must assess the vascularity of the soft tissue bed and the nerve itself, the nerve gap, conduction, and the topography of the fascicles to insure proper orientation. Application of the principles of nerve repair (magnification, minimal tension, meticulous soft tissue handling, experienced surgeon and staff) can enhance the chances for a successful result. Additionally, to maximize functional recovery following peripheral nerve repair, a carefully planned program of postoperative occupational therapy and rehabilitation must be instituted.

Lifetime patterns of contraception and their relationship to unintended pregnancies.

BACKGROUND: For the past 30 years many effective methods of contraception have been available, yet unintended pregnancy rates still range from 30% to 50% in many populations. We examined patterns of women's contraceptive use throughout their lives and relate them to unintended pregnancy. METHODS: A total of 396 women aged 18 to 50 years chosen by convenience sampling from a family practice residency office were interviewed in a cross-sectional study about their history of using and changing contraception, and whether they believed they became pregnant while using a method of contraception. We analyzed the data for correlations and significance using chi-square and Student t tests. RESULTS: Most women had used both condoms and oral contraceptive pills, and tried an average of 3.54 methods during a lifetime. Two patterns of women's use of contraception emerged that describe 75% of the women. One third of the women--those who indicated a pattern of following their first method with a less effective method--are significantly more likely to have an unintended pregnancy while using contraception (odds ratio=1.4). The other group (50% of the entire sample) used increasingly effective methods and were less likely to have an unintended pregnancy. CONCLUSIONS: Pregnancy is an inherent natural consequence of sexual intercourse, even when using very effective contraceptive methods. By asking a few questions about a woman's history of contraceptive use, physicians may be able to determine those who are more likely to be at risk for an unintended pregnancy.

The Experience of Leader-Led Peer Supervision: Genetic Counselors' Perspectives.

As we proceed through our professional lives, it is essential that we challengeourselves in order to continue to develop our genetic counseling skills. Conferences, workshops,post-graduate courses, journal clubs, and involvement in professional organizations havebecome the traditional methods of continuing education for post-graduate geneticcounselors. While these forums address the need to stay updated on scientific orinformation-based topics, there is little available to counselors to promote growth incounseling skills. A group of Boston-based genetic counselors describe how their leader-ledsupervision group has established a setting to meet the needs of its members both forsupport and continued counseling training. We outline here the evolution of this group andhow it has become a valued part of our professional lives. We feel that the model of leader-ledpeer supervision holds great value in helping genetic counselors continue to enhancetheir interpersonal skills in a supportive, safe, and challenging environment. It is our hopethat others will elect to form similar groups in their own communities, thereby creating newopportunities for growth within the genetic counseling profession.

An adipogenic cofactor bound by the differentiation domain of PPARgamma.

Ligand activation of the nuclear receptor PPARgamma induces adipogenesis and increases insulin sensitivity, while activation of other PPAR isoforms (-alpha and -delta) induces little or no fat cell differentiation. Expression and activation of chimeras formed between PPARgamma and PPARdelta in fibroblasts has allowed us to localize a major domain of PPARgamma responsible for adipogenesis to the N-terminal 138 amino acids, a region with AF-1 transcriptional activity. Using this region of PPARgamma as bait, we have used a yeast two-hybrid screen to clone a novel protein, termed PGC-2, containing a partial SCAN domain. PGC-2 binds to and increases the transcriptional activity of PPARgamma but does not interact with other PPARs or most other nuclear receptors. Ectopic expression of PGC-2 in preadipocytes containing endogenous PPARgamma causes a dramatic increase in fat cell differentiation at both the morphological and molecular levels. These results suggest that interactions between PGC-2, a receptor isoform-selective cofactor and PPARgamma contribute to the adipogenic action of this receptor.

Biochemical analysis of p120/130: a protein-tyrosine kinase substrate restricted to T and myeloid cells.

T cell activation is mediated by a cascade of intracellular events involving protein-tyrosine kinases and their substrates. p56(lck) and p59(fyn) are protein-tyrosine kinases that associate with CD4/CD8 and the TCRzeta/CD3 complex, respectively. We previously reported the appearance of a protein doublet at 120 and 130 kDa that preferentially associates with p59(fyn) and undergoes tyrosine phosphorylation upon receptor ligation. In this paper, we demonstrate that p120/130 is a novel protein that is restricted in expression to T cells, thymocytes and myeloid cells. Internal peptide sequencing and immunoblotting using an anti-p120/130 antisera showed that p120/130 is a unique protein that is distinct from p130(cas) and p125(cbl). By contrast, p120 and p130 shared similar peptide patterns and are structurally related. Alkaline phosphatase digestion of precipitates showed that they are not related due to phosphorylation. p120/130 was found to associate constitutively with a 55-kDa protein of unknown identity, but which is distinct from p56(lck) and Shc. p120/130 also undergoes a unique kinetics of phosphorylation and associates with the Ag receptor in response to TCR ligation. In keeping with the association with p59(fyn), T cells from p59(fyn)-negative mice exhibit reduced phosphorylation of the protein. p120/130 therefore represents a novel TCR associated intracellular molecule with potential to play a role in T cell signaling.

Attitudes toward the prenatal diagnosis of cystic fibrosis: factors in decision making among affected families.

The objective of this study was to explore psychosocial factors underlying decisions about use of prenatal diagnosis for cystic fibrosis (CF), among parents of affected children. Anonymous survey questionnaires, supplemented by voluntary interviews, were used at 12 CF centers in six New England states, for a consecutive sample of families of minor children visiting CF centers during a 4-mo period. In all, 227 (71%) of 318 families responded. We hypothesized that attitudes toward utilization would be affected by (a) intentions to have children, (b) knowledge, (c) perception of risk, (d) the health of the child with CF, (e) expectations about the child's future, (f) attitudes toward abortion, (g) insurance, (h) genetic counseling, and (i) sociodemographic factors (including attendance at religious services). Of the 227 couples who responded, 69% were surgically sterile, over 45 years of age, widowed, or divorced, and 31% were at risk. Of 70 at-risk couples, 44% intended to have more children; of these, 77% had had or were considering CF prenatal diagnosis. Most families knew CF could be diagnosed prenatally; 20% would terminate for CF. Among intended prenatal diagnosis users, 44% would carry a fetus with CF to term, 28% would abort, and 28% were undecided. Stepwise logistic regression showed three variables significantly related to intentions to use prenatal diagnosis: (1) respondent's willingness to abort for CF (P less than .02, odds ratio 3.36), (2) respondent's siblings' approval of abortion for CF (P less than .03, odds ratio 2.99), and (3) respondent listed no accomplishments for the child with CF (P less than .09, odds ratio 3.01). The majority of affected families reject selective abortion for CF; many will curtail childbearing rather than use prenatal diagnosis.

Attitudes toward abortion among parents of children with cystic fibrosis.

BACKGROUND: DNA prenatal diagnosis for cystic fibrosis (CF) has been available for parents of affected children since late 1985. METHODS: Using anonymous questionnaires, we surveyed 395 parents of children with CF at 12 New England CF centers with regard to 12 maternal or family situations and 11 fetal characteristics; 271 (68%) responded. RESULTS: The majority supported legal abortion in the first trimester for all 23 situations; 58% would abort for severe mental retardation (MR), 40% would abort for a genetic disorder leading to death before age five years, 41% for a child bedridden for life, 35% for moderate MR, 20% for CF and 17% for a severe incurable disorder starting at age 40 years. Few would abort for a disorder starting at age 60 years, for genetic susceptibility to alcoholism or for sex selection. Variables most strongly related to abortion for CF were attitudes of spouse, respondent's siblings, and CF doctor toward abortion for CF as well as infrequent attendance at religious services. CONCLUSIONS: Prenatal diagnosis may not reduce substantially the number of CF births to parents of CF children because most do not accept abortion for CF.

Serotyping of Campylobacter jejuni from an outbreak of enteritis implicating chicken.

An outbreak of campylobacter enteritis involving 7 of 17 people over a period of 5 days followed a dinner at a restaurant. A chicken casserole dish was implicated with a food-specific attack rate of 58%. Campylobacter jejuni Penner serotype 18/21/29, resistant to metronidazole, was isolated from 3 of 4 symptomatic patients and from three raw fresh chicken samples closely associated with the implicated chicken. Numbers of C. jejuni in the chicken ranged from 5.3 X 10(1) to 7.5 X 10(2) colony forming units per square centimeter of surface area. This is the first outbreak of campylobacter enteritis reported in Australia in which C. jejuni has been isolated from both human and food sources and the isolates serologically confirmed as identical.

Campylobacter jejuni: incidence in processed broilers and biotype distribution in human and broiler isolates.

Campylobacter jejuni was isolated from 18 of 40 processed broiler carcasses and 134 of 327 cloacal swabs obtained at four processing plants in Sydney, Australia. Three of four flocks examined carried C. jejuni. Eighty-two percent of chicken and 98% of human isolates from the area were of identical biotypes.