As Oswego State students return from spring break relaxing after the stressful midterm week, biochemistry majors Kaitlyn McCue and Christina Li are finishing their research experiment examining whether stress could affect the immune system.

McCue and Li studied the connection between stress levels and infection with mosquito-borne diseases such as Zika, Dengue and Chikungunya from patient hair samples collected in Machala, Ecuador.

Working with their research advisor Kestas Bendiskas of the biochemistry program and in collaboration with researchers at the SUNY Upstate Medical University in Syracuse and local clinics in Machala, the Oswego research team built upon prior research by these teams to investigate the link between these diseases and stress levels.

“We’re providing the concrete information that supports [their] data,” McCue explained, as the Oswego team is focusing on measurable stress levels.

To evaluate stress, the Oswego researchers are measuring the cortisol concentration of their patients’ hair samples. Stress is a physiological reaction, with the body releasing hormones to compensate.

“Cortisol is that hormone that is released by the body and is like a biomarker for stress,” Li said.

The team used hair samples “because hair grows at a rate of about 1 cm per month. It serves as a good measurement for long-term stress,” McCue said. “Compared to different sampling methods like blood or urine, that’s only for the stress that day, whereas hair can measure it for about a month.”

The students are measuring the actual cortisol concentration within patients rather than measuring perceived stress, McCue said.

The data would then be compared between healthy patients and those with Zika, Chikungunya and different forms of Dengue. These measured values are more useful to scientists because they can draw stronger connections between data than simply survey responses, as perceived stress can be subjective for each patient.

The results of the experiment surprised the team, who expected cortisol levels to be higher among poorer patients and those with more severe forms of disease.

“What we actually found was that the index patients, the patients that had the diseases, had lower cortisol levels [than those without symptoms],” McCue said.

While surprising, the team found a basis for the results – those that live in high-stress environments are better able to cope and receive less cortisol from their bodies. If someone is less accustomed to stress, their body might not be good at dealing and coping with stress, so cortisol levels can be really high when they encounter stress, Li said.

“There was a previous study where they looked at PTSD veterans, and they found the same thing, where it was a low cortisol level with people that were constantly exposed to combat,” Li said. “It was surprising. It’s not what you expect, but if you think about it, it makes sense.”

To collect the samples, Bendiskas arranged for the Machala clinics to collect the hair samples. McCue explained that collaborators did the fieldwork in Machala, Ecuador, sending a sample of hair from the back of the patient’s head, per Bendiskas’ direction.

While the protocols were for a centimeter length of hair wrapped in non-static aluminum, the Oswego team received long lengths about the width of a pencil in static-charged plastic bags. The team needed the hair in 2 mm pieces.

“It took approximately 40 minutes to cut each hair sample, and there’s 156 hair samples, so it took a long time to just prepare the hair samples,” McCue said, laughing.

In the future, McCue and Li said they hope to work with a larger sample of index patients, the non-control patients examined by the study, in order to get a better sample size for statistical analysis. The team recently received the data back from SUNY Upstate Medical University and will take advantage of Friday’s holiday to analyze the data set.

The researchers hope the study will help them provide the framework for better prevention, control and disease surveillance models. Their work is the first study to associate hair cortisol concentrations with mosquito disease status while looking at other correlations between cortisol levels and age, gender or other cross-sections of their data.

The students are excited to finalize the project, which McCue will be presenting Wednesday during Oswego State’s Quest event.

The team decided to come in and work on the project with the help of Bendiskas instead of enjoying their break.

“We worked on this for the last seven months” McCue said. “We also worked on it over winter break for a couple of weeks because it would’ve been too hard to balance doing all this work with school at the same time.”

Next year, McCue will be attending SUNY Upstate Medical University PhD program for biomedical s ciences while Li has an internship at Upstate Medical University this summer before starting her senior year next fall.

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