Discipline: Biological Sciences
Subcategory: Physiology and Health
Obinna Asawabelem - Howard University
Co-Author(s): Nicholas Guthrie, Howard University College of Medicine, Washington, DC ; Shihyun Kim, Howard University College of Medicine, Washington, DC ; Kesley Green, Howard University College of Medicine, Washington, DC ; Fatimah Jackson, Ph.D, Howard University Department of Biology, Washington, DC
Rib notching can occur on the inferior or superior surfaces of the ribs. Associated with a wide range of congenital and chronic disorders, rib notching is an important diagnostic marker used in the practice of medicine today. Unfortunately, Rib notches have not been studied in a human skeletal collection, and furthermore, a historical African American (AA) collection. This presents a unique opportunity to evaluate rib notching in the Cobb Collection (CC), originally comprised of 987 de-fleshed human cadavers that were either donated between 1931 and 1965, housed at the W. Montague Cobb Research Laboratory at Howard University (CRL). A sample of 49 CC individuals were selected and placed into groups to explore the hypothesis that rib notching can be used to indicate cardiovascular disease (CVD) in a skeletal collection. Our results show a strong link between CVD and rib notching. This provides a useful tool for diagnosing historical skeletal samples, using modern techniques to confirm previous diagnoses. BACKGROUND: Vascular structures undergo alterations to compensate for certain changes in the body such as extreme blood pressure levels, blockage of blood flow, and even imbalanced hormone levels. This vasculature may lengthen or thicken in response to high pressure, which may apply enough pressure and force to change the structures around them. Rib notching, therefore, can either be caused by vascular or non-vascular causes. Vascular rib notching is caused by enlarged intercostal vasculature which put greater pressure onto their neighboring ribs and, consequently, lead to bony erosion. Non-vascular rib notching are caused by neurogenic conditions such as neuromas and neurofibromatosis or irregular cortical thickening due to diseases such as hyperparathyroidism. Rib notching can also be classified based on location. Inferior Rib notching can have etiologies ranging from arterial, venous, neurogenic, and osseous causes. Superior rib notching, similarly, has osseous, autoimmune, and genetic etiologies. Rib notching has not been studied in a human skeletal collection, and furthermore, a historical AA collection. Historically, there has been a huge discrepancy between the amount of historical data and previous literature studies on minorities, namely AAs, compared to their other counterparts. There has been put forth a lot of effort in the past few decades to bridge the gap between the major contribution of AA biological information. This study provides a significant advantage in improving the inventory of literature on AA and on the subject of rib notching within that population. METHODS: Equipped with IRB-exemption for studying historic skeletal and dental remains, CITI-certified researchers evaluated the 987 clinical records of the Cobb Collection to identify individuals who died from cardiovascular involved diseases based on the ICD-10 classification of “Diseases of the Circulatory System”. A random sampling of non-cardiovascular involved group was also selected as a control. For each specimen being studied, ribs were assembled according to size. Due to incomplete and broken rib collections of certain individuals, the exact anatomical location of ribs were not analyzed; instead, ribs were prepared from smallest to longest ribs, with the smallest rib given a designation of “1” and numbering to follow. Ribs with notches were identified; ribs 3-9 (double check numbers) were more likely to have rib notching. Data for specific criteria were collected: Each individual was examined to determine whether the notches were unilateral or bilateral, total number of notches, and location of notches. If an individual was reported to have signs of rib notching, the arranged ribs as a whole and the individual ribs with signs of notching were photographed. In addition, care was taken not to count deformities or breaks in the skeletal materials. Ribs with clearly evident non-natural edges and man-made made notches were not included in the sampling. RESULTS: In the Cobb Collection, there are a total of 987 individuals, 780 of which have records of cause of death. From the records that are present, 49 individuals were surveyed for rib notching. Of the 49, 10 were female (range of *** avg age 55.5 years) and 39 were male (avg age 59.0). In addition, Demographic classification of the individuals were 9 colored, 3 white, and 37 negro. There are 13 individuals who were found to have rib notching present. Of these 13 individuals, 10 were male and 3 were female. Demographic information revealed 9 were classified as Negro, 2 as Colored, and 1 as White. For the purposes of this study, Negro and Colored are collapsed into a single category and designated as African American (AA). White is reclassified as European American (EA).Not Submitted
Funder Acknowledgement(s): We would like to thank Dr. Fatimah Jackson, Mr. ZhenHong Chen, and other researchers at the W. Montague Cobb Research Lab. We would also like to thank Dr. John Stubbs and his team from the Howard University College of Medicine for providing the opportunity to conduct research through Howard University's Medical Student Summer Research Program. None of this would have been possible if it were not for the donors and their family members who made the ultimate sacrifice in the name of science, thus paving the road for minority researchers. We hope that one day, our collective efforts will inspire future generations and ultimately help improve medicine.
Faculty Advisor: Fatimah Jackson, Ph.D., firstname.lastname@example.org
Role: For each individual studied, I arranged the ribs according to size, from smallest to longest, with the smallest rib given a designation of '1'. Ribs with notches were identified but due to incomplete and broken rib collections of certain individuals, the exact anatomical location of ribs were not examined. Each individual was examined to determine whether the notches were unilateral or bilateral, total number of notches, and location of notches. If an individual was reported to have signs of rib notching, I primarily assembled the ribs as a whole and photographed the individual ribs with signs of notching present.