Novel Bionics Assessment of Anorectal Mechanosensory Physiology

Biomechatronics (bionics) is an applied science that creates interdisciplinary bonds between biology and engineering. The lower gastrointestinal (GI) tract is difficult to study but has gained interest in recent decades from a bionics point of view. Ingestible capsules that record physiological variables during GI transit have been developed and used for detailed analysis of colon transit and motility. Recently, a simulated stool named Fecobionics was developed. It has the consistency and shape of normal stool. Fecobionics records a variety of parameters including pressures, bending, and shape changes. It has been used to study defecation patterns in large animals and humans, including patients with symptoms of obstructed defecation and fecal incontinence. Recently, it was applied in a canine colon model where it revealed patterns consistent with shallow waves originating from slow waves generated by the interstitial Cells of Cajal. Novel analysis such as the “rear-front” pressure diagram and quantification of defecation indices has been developed for Fecobionics. GI research has traditionally been based on experimental approaches. Mathematical modeling is a unique way to deal with the complexity. This paper describes the Fecobionics technology, related mechano-physiological modeling analyses, and outlines perspectives for future applications.

Observations on the Flagellates of the Genera Trichomonas and Eutrichomastix

Three pure-line strains started from single individuals, 2 of Trichomonas and 1 of Eutrichomastix, all from snakes, were isolated from mixed cultures. These strains, and another of Eutrichomastix from a chamaeleon, were under observation for periods of from 3 to 10 weeks.The Eutrichomastix of snakes does not differ from that of the chamaeleon in any essential point, and neither developed an undulating membrane at any time during this prolonged period of observation.The Trichomonas of the grass-snake is morphologically distinct from that of the boa. Trichomonas of the boa has an ill-developed undulating membrane with only a few shallow waves, and may simulate a Eutrichomastix owing to the accidental detachment of the bordering flagellum.Trichomonas from snakes, as from most other hosts, readily feeds upon starch granules, whereas none of the Eutrichomastix were found to ingest unaltered starch.Eutrichomastix from snakes and the chamaeleon never develops an undulating membrane and does not assume a Trichomonas form.From these observations it can be definitely concluded that Trichomonas and Eutrichomastix are generically distinct.