Abraham Colles and his contributions to anatomy.

Abraham Colles is known among the medical community for his detailed description of Colles' fracture, one of the most common occurring skeletal injuries. It is remarkable that something as seemingly simple as the diagnosis of Colles' fracture had not been established until nearly 200 years ago. While that may have been his most well known accomplishment, Colles made several other contributions to medicine across multiple fields of practice. In the field of anatomy, he is also credited for his discovery and description of Colles' fascia and Colles' ligament. Less commonly known, however, are his clinical observations and offered treatment regimens for syphilis, as well as his achievement in performing the first surgery for axillary artery aneurysm. The current paper will review the life and contributions of this early surgeon and anatomist.

A historical perspective: Bernhard von Langenbeck German surgeon (1810-1887).

Bernhard von Langenbeck is undeniably one of the world's greatest surgeons and inventors. The influence which he exerted upon the practice of surgery, as apparent by the numerous surgical tools and 21 operations credited to his name, represents the notable contributions of this amazing man. Despite the tools and techniques which bear his name, the establishment of a surgical journal, and his role in co-founding the German Surgical Society, many attest that Bernhard von Langenbeck's greatest contribution to the professional field was the vast knowledge he imparted on his pupils. Commonly credited with training nearly every celebrated surgical operator of his time, von Langenbeck merits posthumous acknowledgement for his vast contributions to the field of medicine and surgery.

Benjamin Alcock (1801-?) and his canal.

Benjamin Alcock (1801-?) was a prominent anatomist from Ireland who is remembered most for his description of the pudendal canal. He was privileged to train under the great Irish anatomist, Abraham Colles. Following his training and several early teaching engagements, he was appointed as the first Professor of Anatomy and Physiology at Queen's College, Cork. He became a Fellow of the Royal College of Surgeons in Ireland. After several years of teaching at Queen's College, Alcock was forced to resign after a dispute over the Anatomy Act of 1832, during which he conveyed his disapproval of participation in the procurement of corpses for the school. Several years after his resignation, he left for the United States and removed himself from the view of the profession. His anatomical contributions were published in The Cyclopaedia of Anatomy and Physiology. The description he gave of the sheath enclosing the pudendal nerve and internal pudendal vessels is his most famous contribution to the literature. He is remembered eponymously for Alcock's canal. This article's intent is to clearly and concisely depict the life and contribution of Benjamin Alcock.

Associated disorders of Chiari Type I malformations: a review.

A single pathophysiological mechanism of Chiari Type I malformations (CM-I) has been a topic of debate. To help better understand CM-I, the authors review disorders known to be associated with CM-I. The primary methodology found among most of them is deformation of the posterior cranial fossa, usually with subsequent decrease in volume. Other mechanisms exist as well, which can be categorized as either congenital or acquired. In understanding the relationship of such disorders with CM-I, we may gain further insight into the process by which cerebellar tonsillar herniation occurs. Some of these pathologies appear to be true associations, but many appear to be spurious.

Circadian rhythms in Neurospora crassa: Downstream effectors.

The circadian rhythm in Neurospora crassa is exhibited as alternating areas of conidiating and non-conidiating mycelia growth. A significant role in this circadian rhythm is played by the frq (frequency) and wc (white-collar) genes, comprising the "FWC" oscillator. Strains lacking the FWC can be restored to rhythmicity, which has been attributed to a second oscillator, called the FLO (frq-less oscillator). This study reports additional conditions that allow this rhythmicity to occur. Rhythmicity was restored to mutants lacking either the frq, or wc-1, or wc-2 genes in D/D (constant darkness) or L/L (constant light) by the addition of low levels of menadione, a known stimulator of ROS (reactive oxygen species). Additional studies are reported on the rhythm effects from caffeine, a known cAMP phospho-diesterase inhibitor as well as the effects from mutations in the csp-1 gene, the rco-1 gene, and other genes. A theme ties all of these "downstream effects" together, i.e., they affect either components thought to be part of the conidiation process itself, or the RAS-cAMP-protein kinase pathway. Since mutations in these components unexpectedly had rhythm effects, this suggests that these components may be good candidates for some part of the frq-less oscillator.

Rhythmic conidiation in constant light in vivid mutants of Neurospora crassa.

In Neurospora crassa, a circadian rhythm of conidiation (asexual spore formation) can be seen on the surface of agar media. This rhythm has a period of 22 hr in constant darkness (D/D). Under constant illumination (L/L), no rhythm is visible and cultures show constant conidiation. However, here we report that strains with a mutation in the vivid (vvd) gene, previously shown to code for the photoreceptor involved in photo-adaptation, exhibit conidiation rhythms in L/L as well as in D/D. The period of the rhythm of vvd strains ranges between 6 and 21 hr in L/L, depending upon the intensity of the light, the carbon source, and the presence of other mutations. Temperature compensation of the period also depends on light intensity. Dark pulses given in L/L shift the phase of the rhythm. Shifts from L/L to D/D show unexpected after effects; i.e., the short period of a vvd strain in L/L gradually lengthens over 2-3 days in D/D. The rhythm in L/L requires the white collar (wc-1) gene, but not the frequency (frq) gene. FRQ protein shows no rhythm in L/L in a vvd strain. The conidiation rhythm in L/L in vvd is therefore driven by a FRQ-less oscillator (FLO).

Peritoneal bands: a review of anatomical distribution and clinical implications.

The complexity of embryological development of the gastrointestinal tract and mesentery provides a platform for the formation of a wide variety of variant veils, folds, and membranes, collectively termed peritoneal bands. These structures, which represent anatomically unabsorbed portions of the omentum and mesentery, although often benign, have the potential to cause clinically significant manifestations in both the neonate and adult. Although these deviant structures may be identified over a broad range of the abdominal cavity, they are most commonly identified in the regions of the duodenum, duodenojejunal flexure, ileocecal junction, and ascending colon. As a result of the diverse location of these variant structures, clinical manifestations are highly variable, ranging from acute presentations of intestinal necrosis as a result of strangulated midgut volvulus to chronic, vague abdominal pain. This article seeks to highlight the importance of a thorough anatomical understanding of the distribution of the various abnormal peritoneal folds, bands, and ligaments, which may result from aberrations in embryonic gastrointestinal development and their respective clinical implications. Moreover, to advance the knowledge of peritoneal bands, this article discusses the appropriate diagnostic studies and treatment interventions required for these variant structures.