- Published: October 7, 2021
- By: Arkana Author
Oh baby, another Arkana Tot is on the way! We showered our mom-to-be, Nicki, with all of the bows and diapers for baby Saylor. We can't wait to meet her!
- Published: October 5, 2021
- By: Stephen Bonsib, M.D., M.S.
- Tags: duct of Bellini, papillary tip, renal papilla, urothelial cells
Today’s eyeSCANdy image shows scanning EM of normal papillary tip showing the ostia of a duct of Bellini and surrounding urothelial cells. Photo credits to Dr. Stephen Bonsib!
- Published: October 1, 2021
- By: Jon Wilson, MD
- Tags: Myelin incisure, Node of Ranvier, PNS, Schwann cells
The patient is a 70-year-old male with recent bilateral foot drop. Laboratory studies showed normal/negative pANCA, cANCA, and MPO. His symptoms partially responded to treatment with prednisone. Nerve biopsy was performed to evaluate for vasculitis. What is the structure indicated by the arrow in the image? A. Internode B. Myelin incisure C. Traction artifact D. Node of Ranvier Answer: Node of Ranvier Peripheral nerve “nodes of Ranvier” are small gaps between adjacent segments of myelin sheath formed by individual Schwann cells. The specialized regions are rich in voltage-gated sodium ion channels and act as “booster stations” for the rapid...
- Published: September 28, 2021
- By: Stephen Bonsib, M.D., M.S.
- Tags: glomerular basement membrane, membranous, membranous glomerulonephritis, Scanning Electron Microscopy
This eyeSCANdy image shows an acellular scanning EM with "craters" at high power on the subepithelial aspect of the glomerular basement membranes from a biopsy with membranous glomerulonephritis. Photo credits to Dr. Stephen Bonsib!
- Published: September 27, 2021
- By: Arkana Author
Dr. Rachelle Gietzen has officially finished her renal path rotation at Arkana! We were so thrilled to immerse her in the world of kidney pathology this past month. As the winner of the Arkana Renal Rotation Award, she’s headed home with a certificate of completion of her training, a cash award of $1000, and a gift of a renal pathology book. And of course, a new love of kidney pathology. Interested in applying to our rotation? Find more info here - https://www.arkanalabs.com/education/renal-rotation/
- Published: September 24, 2021
- By: Jon Wilson, MD
- Tags: muscle fiber spindle, muscle fibers, Myotatic, skeletal muscle
The intrafusal muscle fibers also serve which of the following purposes? A. Force generation B. Maintain spindle tension C. Protein storage D. Protect nerves Answer: Maintain spindle tension The intrafusal muscle fibers are innervated by gamma and beta motor neurons and contract or relax to maintain the sensitivity of the spindle. For example when the quadriceps muscle contracts and becomes shorter, the intrafusal muscle fibers take up slack in the spindle to maintain its sensitivity to stretch. The intrafusal muscle fibers do not contribute significantly to the force of the muscle contraction, store significant protein, or protect nerves....
- Published: September 21, 2021
- By: Stephen Bonsib, M.D., M.S.
- Tags: acellular EM, craters, glomerular basement membrane, Segmental membranous
Today’s eyeSCANdy image shows scanning EM of acellular capillary loops from a biopsy with segmental membranous GN. Note the GBM crater formation along the BMs at middle left with relatively smooth BMs in other GBMs. Photo credits to Dr. Stephen Bonsib!
- Published: September 17, 2021
- By: Jon Wilson, MD
- Tags: muscle fiber spindle, muscle fibers, Myotatic, skeletal muscle
Toluidine blue-stained thick section prepared from glutaraldehyde-fixed EPON embedded tissue (400x original magnification) What of the following single choices regarding this structure is false? A. Generates contraction B. Senses muscle stretch C. Common in muscle D. Part of myotatic reflex Answer: Generates contraction The muscle fiber spindle detects length and rate of muscle stretch, is the most frequently found sense organ in skeletal muscle, and is part of the deep tendon reflex (monosynaptic stretch reflex/myotatic reflex). It does not contribute significantly to the force of muscle contraction. References Banks RW. The innervation of the muscle spindle: a personal history....
- Published: September 14, 2021
- By: Stephen Bonsib, M.D., M.S.
- Tags: acellular EM, craters, glomerular basement membrane, Segmental membranous
This eyeSCANdy image shows acellular SEM in segmental membranous GN showing large craters (arrows) along the GBM. Photo credits to Dr. Stephen Bonsib!
- Published: September 10, 2021
- By: Arkana Author
Our MYMP made a special appearance this week! Dr. Cassol (along with Dr. Sharma) recently published an article highlighting the underuse of machine learning as a research tool in the field of nephrology, titled Nephrology Lagging Behind in Machine Learning Utilization. Read the paper here: https://www.kidney-international.org/article/S0085-2538(21)00734-1/fulltext