Maria Ximena Leighton

Dr. Maria Ximena Leighton


Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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MSMeera Srivastava
Meera Srivastava
ABAlakesh Bera
Alakesh Bera
OEOfer Eidelman
Ofer Eidelman
MTMinh B. Tran
Minh B. Tran
CJCatherine Jozwik
Catherine Jozwik
HPHarvey Pollard
Harvey Pollard
Annexin A7/ANXA7 is a calcium-dependent membrane fusion protein with tumor suppressor gene (TSG) properties, which is located on chromosome 10q21 and is thought to function in the regulation of calcium homeostasis and tumorigenesis. However, whether the molecular mechanisms for tumor suppression are also involved in the calcium- and phospholipid-binding properties of ANXA7 remain to be elucidated. We hypothesized that the 4 C-terminal endonexin-fold repeats in ANXA7 (GX(X)GT), which are contained within each of the 4 annexin repeats with 70 amino acids, are responsible for both calcium- and GTP-dependent membrane fusion and the tumor suppressor function. Here, we identified a dominant-negative triple mutant (DNTM/DN-ANXA7J) that dramatically suppressed the ability of ANXA7 to fuse with artificial membranes while also inhibiting tumor cell proliferation and sensitizing cells to cell death. We also found that the [DNTM]ANA7 mutation altered the membrane fusion rate and the ability to bind calcium and phospholipids. In addition, in prostate cancer cells, our data revealed that variations in phosphatidylserine exposure, membrane permeabilization, and cellular apoptosis were associated with differential IP3 receptor expression and PI3K/AKT/mTOR modulation. In conclusion, we discovered a triple mutant of ANXA7, associated with calcium and phospholipid binding, which leads to the loss of several essential functions of ANXA7 pertinent to tumor protection and highlights the importance of the calcium signaling and membrane fusion functions of ANXA7 for preventing tumorigenesis.

30 June 2022 in Diagnostics
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ASAriana Sheridan
Ariana Sheridan
ERElizabeth Reynolds
Elizabeth Reynolds
EMElizabeh Maynes
Elizabeh Maynes
GWGary Wind
Gary Wind
MLMaria Ximena Leighton
Maria Ximena Leighton
Guinevere GraniteGuinevere Granite
Guinevere Granite
A detailed understanding of the enteric vascular supply is of great importance for pre-operative planning. In the case of this 68-year-old white male donor, the following variations were observed: a hepatogastrophrenic trunk, a celiacomesenteric trunk, and a middle mesenteric artery. Literature review was conducted to understand the frequency and clinical significance of these variations.

10 April 2023 in Anatomia
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JKJoanna Klansek
Joanna Klansek
KMKeiko Meshida
Keiko Meshida
EMElizabeh Maynes
Elizabeh Maynes
MLMaria Ximena Leighton
Maria Ximena Leighton
GWGary Wind
Gary Wind
Guinevere GraniteGuinevere Granite
Guinevere Granite
While relatively uncommon, a duplication of the inferior vena cava is moderately well-discussed in the literature. This anatomical variation was noted in a 69-year-old white female donor. This variation is typically asymptomatic; however, it can be associated with complications, such as confusion with a mediastinal mass, increased risk for thromboembolism, and hemorrhage during surgery. It is also associated with a handful of comorbidities, including, but not limited to, congenital renal anomalies such as horseshoe kidney or fused crossed kidney. Research supports that the variation of a duplicated IVC (DIVC) can be due to a failure of the left supracardinal vein to regress during embryonic development.

20 September 2022 in Diagnostics
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Andrea SparksAndrea Sparks
Andrea Sparks
SOScott Oplinger
Scott Oplinger
EMElizabeh Maynes
Elizabeh Maynes
KMKeiko Meshida
Keiko Meshida
MLMaria Ximena Leighton
Maria Ximena Leighton
Guinevere GraniteGuinevere Granite
Guinevere Granite
Screening for abdominal aortic aneurysms became the standard of care in 2005, yet screening procedures continue to be underutilized. While improvements in mortality rates have been noted over the past 15 years, continued patient mortality from ruptured abdominal aortic aneurysms suggests a need for further research, regarding the effectiveness of the current screening process. Abdominal aortic aneurysms can progress silently, and the risk of rupture increases significantly with increase in diameter. We report a large, untreated infrarenal abdominal aortic aneurysm of 17 cm in length and 8 cm in diameter, showing the chronic atherothrombosis discovered in a 91 year-old white male cadaveric donor. A literature review was conducted to elucidate current understanding of the pathology, risk factors, screening recommendations, and treatment options available for abdominal aortic aneurysms.

16 March 2023 in Anatomia
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Isabella PenkwitzIsabella Penkwitz
Isabella Penkwitz
GWGary Wind
Gary Wind
EMElizabeh Maynes
Elizabeh Maynes
MLMaria Ximena Leighton
Maria Ximena Leighton
Guinevere GraniteGuinevere Granite
Guinevere Granite
Forearm extensor muscle variations can be diverse and, in some instances, rare. During a routine anatomical dissection of human cadaveric donors during the 2021 first-year medical gross anatomy course and 2021 graduate nursing advanced anatomy course at the Uniformed Services University of the Health Sciences, bilateral agenesis of the extensor carpi ulnaris muscle was noted in one 70-year-old white male donor. This variation is described as extremely rare in the literature. The presence of an extensor indicis et digiti medii tendon, a variant of the extensor indicis tendon, appeared to be evident in post-dissection photographs on the left hand. The presence of a duplicated extensor indicis proprious tendon appears to be evident on the right hand. However, further inspection of this region was impeded as the body was sent for cremation prior to the variation being identified. The presence of various juncturae tendinum was also noted bilaterally. Reported prevalence of extensor indicis muscle variants ranges from 0.75% to 13%, depending on the specific type or grouping of variations observed. Knowledge of variations in the extensor compartment of the forearm and wrist is crucial for orthopedic surgeons and specialists. Alteration of surgical approaches may be necessary if such a variation is present. Such variations can be options for grafts, resulting in minimal functional change to the grafted area due to the continued existence of other muscles performing similar functions. Knowledge of such variations, and alternative, synonymous names for them, is also important for anatomy instructors, who may need to assist students in identifying these rare variations during anatomical dissection.

29 June 2023 in International Journal of Cadaveric Studies and Anatomical Variations
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Journal Article
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MLMaria Ximena Leighton
Maria Ximena Leighton
EMElizabeth Maynes
Elizabeth Maynes
KMKeiko Meshida
Keiko Meshida
GWGary Wind
Gary Wind
Guinevere GraniteGuinevere Granite
Guinevere Granite
During anatomical dissection of fifty donors in the 2020 undergraduate first-year anatomy course at the Uniformed Services University of the Health Sciences, a high origin of the radial and ulnar arteries, also known as a brachioradial artery and a brachioulnar artery, was observed on the left arm of a 90 year-old White female donor. The bifurcation of the brachial artery occurred in the proximal third of the arm. Both the left brachioradial and left brachioulnar arteries ran superficial and medial to the biceps brachii muscle. The brachioulnar artery continues as the UA in the forearm, ran superficial and lateral to the flexor carpi ulnaris muscle, traversed the flexor retinaculum, and continued to form the superficial arterial palmar arch. The brachioradial artery ran deep to the pronator teres muscle and continued as the RA in the forearm. It presented with an atypical branching pattern and was tortuous until it reached the hand. On the dorsum of the hand, the radial artery runs superficial to the first dorsal interosseous muscle, parallel to the first metacarpal bone. It also reached the palmar side of the hand in an unusual manner. Medical professionals, especially radiologists, orthopedic and vascular surgeons, need to be aware of these variations to avoid iatrogenic injuries during normal procedures, such as venipuncture and intravenous injections. Knowledge of these variations is also important during invasive procedures, such as elbow reconstructive surgery, percutaneous brachial catheterization, and when creating an arteriovenous fistula using the radial artery. When such variations are suspected, Doppler and angiogram studies are necessary.