Serial scintigraphy of choledochal cysts using 131I-rose bengal and 131I-bromsulphalein

Nine cases of congenital choledochal cysts are reported which were correctly diagnosed by 131I-rose bengal or 131I-bromsulphalein (BSP) serial scintigraphy. They were classified by scintigraphic patterns into two types depending on whether biliary obstruction was complete or incomplete. All but two showed incomplete obstruction. The correct diagnosis may be difficult to make by scintigraphy if complete biliary obstruction is present. In such cases the clinical findings and other diagnostic studies, such as angiography or ultrasound, should be carefully considered. Serial scintigraphy with 131I-rose bengal or 131I-BSP is nontraumatic, safe, and provides increased diagnostic accuracy. It is the examination of choice when choledochal cysts are suspected clinically.

Detection of mutagenic activity in particulate air pollutants

Ames's strains of Salmonella typhimurium were used to evaluate the mutagenic activity of airbone particulate materials collected at six different points in the industrial area of Ohmuta and the residential area Fukuoka. Tests were done in presence of rat-liver S-9 fraction isolated from rats that had been treated with Aroclor 1254. When the number of revertant colonies per plate was plotted against the amount of methanol extract of particulate air pollutants, using strain TA98, approximately linear relationships were observed for active samples. Generally, mutagenic activity of the samples increased in proportion to the density of air pollutants. In our system, 38--349 microng of methanol extract, from 0.225--4.51 m3 of air from the factory districts in Ohmuta City gave 100 his+ revertants per plate. On the other hand, 54--2300 microng of air pollutants, from 1.29--14.1 m3 of air from the residential districts in Fukuoka City, gave a comparable activity. Every sample from each area had mutagenic activity. Chemicals in air pollutants were fractionated by alumina column chromatography and identified by gas chromatography and mass spectrometry. More than 28 compounds, including 12 unknown substances were identified as polycyclic hydrocarbons. Twelve of these compounds are already known to be carcinogens and to induce reversions to histidine independence in strain TA98 of Salmonella.

Myosin-free ghosts of single fibers and an attempt to re-form myosin filaments in the ghost fibers

With the final aim of replacing myosin in a single muscle fiber, a technique for removing myosin almost completely from single fibers was developed and an attempt to "re-form" thick filaments in the myosin-free ghosts of single fibers was made. Complete removal of myosin from single glycerol-treated rabbit psoas fibers with Hasselbach-Schneider solution was difficult. However, when skinned glycerol-treated fibers were used and 1% (v/v) Triton X-100 was added to the Hasselbach-Schneider solution, almost complete removal of myosin was possible. The myosin-free ghosts of skinned single fibers were very fragile but retained the overall structure. In the ghost fibers, Z-membranes and thin filaments remained. The ghost fibers, after irrigation with myosin, underwent contraction upon addition of Mg-ATP. In the myosin-irrigated fibers, thick filaments were re-formed in lengths from one Z-membrane to the other Z-membrane of a sarcomere, running parallel to the thin filaments. The packing of these two filaments was not good. The isometric tension developed by the irrigated fibers upon addition of mg-ATP was about 10% of the tension developed by untreated fibers. The weak tension developed by irrigated fibers is probably due to the irregular packing of the thick and thin filaments in the fibers. The ghost fibers also contracted, though only slightly, upon addition of Mg-ATP after irrigation with heavy meromyosin.

Innervation and properties of the smooth muscle of the dog trachea

The membrane potential of dog tracheal muscle was stable at -59.2 mV. The length constant of the muscle tissue was 3.2 mm and the time constant of the membrane was 449 msec. Outward current pulses could not evoke a spike and showed marked rectification of the membrane. Tetraethylammonium, TEA, depolarized the membrane, suppressed the rectification of the membrane, and increased the membrane resistance, and in the presence of TEA outward current pulses could evoke a spike. Acetylcholine and histamine depolarized the membrane but could not evoke a spike. Mechanical response could be evoked by field stimulation via either nerve stimulation or direct muscle stimulation. The mechanical response induced by nerve stimulation was markedly suppressed by atropine. Phentolamine suppressed the contraction which was produced in the presence of atropine, and propranolol suppressed the relaxation. It is unlikely that nonadrenergic-non-cholinergic inhibitory nerves played an important role in the mechanical response. It is concluded regarding the neural actions to the dog trachea that a constriction is induced by cholinergic and adrenergic alpha-action and a dilation is induced by adrenergic beta-action. The relationship between the membrane potential and tension was measured in various [K]o. The mechanical response was triggered by only 5 mV depolarization. The physiological evidence and histological finding were compared in relation to nerve activity on the tracheal muscle activity.