T H E   N I H   C A T A L Y S T     J U L Y  –  A U G U S T   2004

MORE POSTBAC POSTERS: THE MEMORIES OF MAY LINGER ON
by Myrna Zelaya-Quesada

Verónica Chávez, Georgetown University, Washington, D.C., and Kathleen Sullivan, State University of New York, College at Genesco: "Spontaneous" Disclosure in Forensic Interviews
Preceptor: Margaret-Ellen Pipe, Laboratory of Comparative Ethology, NICHD

Spontaneous disclosure of sexual abuse by a victim, particularly a child, is unusual in the context of forensic interviews. Chávez and Sullivan set out to identify factors that might contribute to a child’s willingness to discuss such an experience.

They examined variables related to the children, their family circumstance, the nature of the abuse, the suspect, and the context of the disclosure within the interview.

They found that "spontaneous" disclosure most often occurred among younger children who had been prompted to tell the truth, children who had experienced a prior abuse investigation, and those who had suffered severe abuse—such as penetration.

The victim-suspect relationship and the events that triggered the investigation were not contributing factors. The researchers now plan to explore interviewer variables.

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Michelle Geiss, Bates College, Lewiston, Maine: Sex Differences in Familial Transmission of Migraine
Preceptor: Kathleen Merikangas, Mood and Anxiety Disorders Research Program, NIMH

Geiss’ group sought to examine whether familial transmission could explain the sex differences in lifetime prevalence of migraine headache—about twice as high in women.

Assuming that women’s threshold of risk for migraine is lower than men’s, the investigators reasoned that familial transmission would emerge as an important factor in sex differences if the relatives of men with migraine were found to be at greater risk than the relatives of women with migraine.

They interviewed male and female probands and their first-degree relatives, as well as control subjects and their relatives (a total of 1,501 people). Supporting previous findings in the field, they found a 2.4 times higher incidence of migraine among women and a three times higher incidence among relatives of people with migraine.

But the relatives of male probands were not at greater risk than the relatives of female probands, refuting the notion that familial transmission might explain the sex difference in prevalence. "In fact," Geiss said, "the relatives of female probands were at greater risk—just the opposite of what we thought might be the case."

The researchers will be exploring other explanations, such as maternal transmission and psychosocial factors.

 

Lindsay Zemba, Millersville University, Millersville, Pa.: Sex Differences in Play Behavior among Captive Common Marmosets (Callithrix jacchus
Preceptor: Lucille Roberts, Laboratory of Comparative Ethology, NICHD

Researchers believe that play in young animals may be one form of preparation for social interactions as adults. Zemba and her colleagues observed social groups of common marmosets at the NIH Animal Center in Poolesville to determine how play behavior relates to their social organization.

Common marmosets are monogamous primates that exhibit minimal sexual division of labor as adults. The researchers hypothesized that if social play is "affiliative," it would occur more frequently between the sexes; if "simulative," there would be little sex difference in quantity or quality of play.

Results demonstrated that "play is a form of affiliative behavior," with females receiving and males initiating more social play, especially rough and tumble play, Zemba said. Because the social organization of common marmoset families is similar to that of humans, the findings may be relevant to understanding the role of social play in children, including the potential negative effects of play deprivation in childhood, she added.

 

Seble Chekol, North Carolina State University, Raleigh: The Role of TLP (Trap-like Protein) in Various Cancers
Preceptor: Angelina Felici, Laboratory of Cell Regulation and Carcinogenesis,

Trap-like protein (TLP), which is structurally similar to TGF-b receptor-associated protein, is downregulated or absent in a variety of human cancers, according to the findings of Chekol and her colleagues.

Using a human cancer profiling array that included 13 tumor types, the team documented sparse or absent TLP in 20 to 45 percent of the solid cancer tissue samples they examined, including kidney, colon, stomach, uterus, and breast.

Chekol thinks this downregulation may demonstrate the involvement of the TLP gene in signaling pathways critical in the development of cancer.

To explore this possibility, Chekol cloned the target gene in antisense orientation into a tetracyclin-inducible retroviral vector system with which she infected human breast cancer cells. She intends to inject those tumor cells with reduced TLP levels into nude mice and monitor tumor growth rate.

 

Janet Benjamin, University of Maryland, Baltimore County: Identification of Natural Killer Cells Marker in Rhesus and Pig-tailed Monkeys
Preceptor: Domenico Mavilio, Laboratory of Immunoregulation, NIAID

Natural killer (NK) cells play an important role in simian and human immune systems as the body’s first line of defense against virus and tumor cells. They lyse infected cells by signaling both activating and inhibitory receptors on their surfaces. Benjamin and her colleagues sought to gain a better understanding of the immunophenotype and function of NK cells in monkeys—a pursuit that could aid in HIV vaccine development.

In this study, the researchers turned to the receptors to tease out NK cell function in monkeys. They used flow cytometry analysis to determine the expression of NKp46, NKp30, and NKG2D activating receptors, as well as NKp80 (an activating co-receptor) and NKG2A (an inhibitory receptor) in rhesus and pig-tailed monkeys.

"These new flow cytofluorometric analyses of NKG2A and NKp80, together or alone, combined with CD16 (a marker of human NK cells that is nonspecific in the monkeys), will allow us to identify the entire NK cells subset and to better understand the different roles of NK cells in the pathogenesis of different diseases," Benjamin said.


 

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