Steroids and the brain: 50years of research, conceptual shifts and the ascent of non-classical and membrane-initiated actions

This brief commentary reviews key steps in the history of steroid endocrinology that have resulted in important conceptual shifts. Our understanding of the "Fast Effects of Steroids" now reflect substantial progress, including the major concept that steroids act rapidly on a variety of physiological and behavioral responses, via mechanisms that are too fast to be fully accounted for by classical receptor-dependent regulation of gene transcription. Several so-called 'non-classical' mechanisms have been identified and include binding to membrane receptors and regulating non genomic signaling cascades. We survey the discovery of steroids, the initial characterization of their intracellular receptors, key progress in the understanding of the genomic effects of steroids and then the progressive discovery of the rapid non-classical and membrane-initiated actions of steroids. Foundational discoveries about brain steroid synthesis in neural processes and terminals has converged with emerging evidence for the rapid actions of steroids on brain and behavior. Had the rapid effects of steroids in the central nervous system been discovered first, these molecules would likely now be considered as a class of neurotransmitter.

Walter E. Dandy: his contributions to pituitary surgery in the context of the overall Johns Hopkins Hospital experience

BACKGROUND

Walter E. Dandy (1886-1946) was an outstanding neurosurgeon who spent his entire career at the Johns Hopkins Hospital. After graduating from medical school in 1910, he completed a research fellowship in the Hunterian laboratory with Harvey Cushing and then joined the Department of Surgery as resident, rising to the rank professor in 1931. Dandy made several contributions that helped building the neurosurgical specialty, most famously the introduction of pneumo-ventriculography to image brain lesions for which he received a Nobel prize nomination. He also performed many pituitary surgeries, although his role in this area is less known and overshadowed by that of Cushing's.

PURPOSE

This retrospective cohort study was designed to unveil Dandy's pituitary work and place it in the context of the overall pituitary surgeries performed at the Johns Hopkins Hospital.

METHODS

Pituitary surgery data were obtained by screening the paper and electronic surgical pathology records of the Department of Pathology, as well as the general operating room log books of the Johns Hopkins Hospital housed in the Chesney Medical Archives.

RESULTS

A total of 3211 pituitary surgeries associated with a pathological specimen were performed between February 1902 and July 2017 in 2847 patients. Most of the surgeries (2875 of 3211 89%) were done by 21 neurosurgeons. Dandy ranks 4th as number of surgeries, with 287 pituitary operations in 35 years of activity. He averaged 8 pituitary surgeries per year, a rate that positions him 6th among all Hopkins neurosurgeons. With the exception of his first operation done in July 1912 while Cushing was still at Hopkins, Dandy approached the pituitary gland transcranially, rather than transphenoidally. The majority of Dandy's pituitary patients had a pathological diagnosis of pituitary adenomas, followed by craniopharyngiomas and sellar cysts. In the decades Dandy operated, pituitary surgeries represented 0.56% of the total Johns Hopkins surgeries, a percentage significantly greater (p < 0.001) than the 0.1% observed in modern days. Dandy's pituitary clinical work was matched by important experimental studies done in the early stages of his career.

CONCLUSIONS

This study highlights the role of Dandy as an important contributor to advance our understanding of pathophysiology and treatment of pituitary diseases.

Milestones in the history of diabetes mellitus: The main contributors

Diabetes mellitus is a group of metabolic diseases involving carbohydrate, lipid, and protein metabolism. It is characterized by persistent hyperglycemia which results from defects in insulin secretion, or action or both. Diabetes mellitus has been known since antiquity. Descriptions have been found in the Egyptian papyri, in ancient Indian and Chinese medical literature, as well as, in the work of ancient Greek and Arab physicians. In the 2^nd century AD Aretaeus of Cappadocia provided the first accurate description of diabetes, coining the term diabetes, while in 17^th century Thomas Willis added the term mellitus to the disease, in an attempt to describe the extremely sweet taste of the urine. The important work of the 19^th century French physiologist Claude Bernard, on the glycogenic action of the liver, paved the way for further progress in the study of the disease. In 1889, Oskar Minkowski and Joseph von Mering performed their famous experiment of removing the pancreas from a dog and producing severe and fatal diabetes. In 1921, Frederick Banting and Charles Best extended Minkowski’s and Mering’s experiment. They isolated insulin from pancreatic islets and administrated to patients suffering from type 1 diabetes, saving thus the lives of millions and inaugurating a new era in diabetes treatment.