The History of Myringotomy and Grommets

The first recorded myringotomy was in 1649. Astley Cooper presented 2 papers to the Royal Society in 1801, based on his observations that myringotomy could improve hearing. Widespread inappropriate use of the procedure followed, with no benefit to patients; this led to it falling from favor for many decades. Hermann Schwartze reintroduced myringotomy later in the 19th century. It had been realized earlier that the tympanic membrane heals spontaneously, and much experimentation took place in attempting to keep the perforation open. The first described grommet was made of gold foil. Other materials were tried, including Politzer’s attempts with rubber. Armstrong’s vinyl tube effectively reintroduced grommets into current practice last century. There have been many eponymous variants, but the underlying principle of creating a perforation and maintaining it with a ventilation tube has remained unchanged. Recent studies have cast doubt over the long-term benefits of grommet insertion; is this the end of the third era?

A Very Long Foreign Body in the Bladder

In the urinary tract, foreign body is most commonly found in the urinary bladder. But it is anatomically very difficult for a man to self-insert a long object into the urinary bladder. Here we report a case of a 49-year-old Japanese man who has inserted a 140-cm vinyl tube in the bladder for masturbation. He could not retrieve it, and the bladder foreign body remained in this position for about two years. He was referred to our hospital and open surgery was performed.

History of myringotomy and grommets

The first recorded myringotomy was in 1649. Astley Cooper presented two papers to the Royal Society in 1801, based on his observation that myringotomy could improve hearing. Widespread inappropriate use of the procedure followed, with no benefit to patients; this led to it falling from favour for many decades. Hermann Schwartze reintroduced myringotomy later in the nineteenth century. It had been realised earlier that the tympanic membrane heals spontaneously, and much experimentation took place in attempting to keep the perforation open. The first described grommet was made of gold foil. Other materials were tried, including Politzer's attempts with rubber. Armstrong's vinyl tube effectively reintroduced grommets into current practice last century. There have been many eponymous variants, but the underlying principle of creating a perforation and maintaining it with a ventilation tube has remained unchanged. Recent studies have cast doubt over the long-term benefits of grommet insertion; is this the end of the third era?

Wearable Force Display Using a Particle Mechanical Constraint

A particle mechanical constraint (PMC) is a soft vinyl tube containing Styrofoam beads. It can be freely compressed, elongated, bent, twisted, or otherwise manipulated in all degrees of freedom. Evacuation of the air inside the tube makes the PMC rigid so that it maintains whatever shape it has been given. The stiffness of the PMC is proportional to the reduction in internal pressure below atmospheric pressure. Viscosity is also controlled virtually by changing the inside air pressure in proportion to the speed of transformation of the PMC. We used a PMC to develop a wearable force display that provides the sensation of coming into contact with a wall or of moving in water with viscosity, in addition to that of moving in air. PMC is an inherently passive device that never exerts excessive force if it were to malfunction. In short, it is suitable as a wearable human interface because it is light, soft, and safe.

Evaluation of Asparagus officinalis Cultivars for Resistance to Stem Blight by Using a Novel Inoculation Method

Asparagus officinalis L. cultivars were evaluated for resistance to asparagus stem blight caused by Phomopsis asparagi (Sacc.) Bubák under controlled environmental conditions. The plants were inoculated with the vinyl tube and cotton inoculation method. Disease severity assessments, based on the percentage of diseased plants and the disease index, were made 4 weeks after inoculation. Estimates of the percentage of diseased plants ranged from 33% to 80%, and the disease index ranged from 28 to 79. None of the cultivars and lines showed high resistance, but there were significant differences in disease susceptibility among the cultivars and lines.

Acetylcholinesterase (AChE) demonstrated by a vascular perfusion incubation technique

For the cytochemical demonstration of enzymes, the commonly employed procedures involve using chopped small cubes or sections of tissue incubated in a proper medium. With the chopped tissue, penetration of substrate and capturing agents is very slow. When using frozen sections artifacts are difficult to avoid. Also proper vibratome sections are hard to achieve with small organs such as the pineal gland. In order to overcome these disadvantages, we have developed a vascular perfusion incubation technique for the demonstration of AChE.With this technique, a simple gravity flow apparatus for vascular perfusion with two glass containers for fixative and Tyrode solution was used. A needle (19g) with a 32 cm long vinyl tube was connected to the apparatus by a three-way valve. Adult Djungarian hamsters were anesthetized with 1.5 g/kg urethane. The needle was inserted into the ascending aorta through the left ventricle. The following solutions were then perfused for the times indicated: Tyrode, 1 min; fixative (1% purified glutaraldehyde and 2% formaldehyde, 0.05 M cacodylate buffer, pH 7.2), 5 min; Tyrode, 10 min; substrate-free incubation medium, 10 min; complete incubation medium, 20 min; pause for 10 min; repeat of the last two steps four times; isotonic sodium sulphate, 10 min; buffered sulphide, 30 min; isotonic sodium sulphate, 10 min; fixative (3% glutaraldehyde and 2% formaldehyde, 0.05 M cacodylate buffer), 5 min. The entire pineal gland and pieces of the tongue were taken. After osmium postfixation standard electron microscopic procedures were used.

Mixing in the Human Carotid Artery during Carotid Drug Infusion Studied with PET

The safety and efficacy of drug infusion into the carotid artery require adequate mixing of the infused solution with carotid blood. Using positron emission tomography (PET), we studied the mixing of solutions infused into the human carotid artery in seven patients by analyzing the distribution of [15O]H2O infused into the carotid artery and by vein. At four infusion rates ranging from 0.5 to 10 ml/min, the variability in distribution averaged 16.5–17.8% among the pixels in a large volume of interest, without dependence on the infusion rate. The overall correlation between [15O]H2O influx with arterial infusion and [15O]H2O influx with venous injection was 0.78–0.82 at the four infusion rates, with no trend toward higher correlations at the faster infusion rates. The distribution into the anterior, middle, and posterior cerebral artery territories differed from distribution throughout the entire carotid territory by an average of 6.2–9.6% at the four infusion rates, with no trend toward smaller differences at the faster infusion rates. Infusions performed into a vinyl tube simulating the carotid artery indicated that at 0.5 ml/min, the velocity of fluid exiting the catheter makes no apparent contribution to mixing. We conclude that with infusions at the carotid bifurcation, mixing in the human carotid artery is complete or nearly complete over a wide range of infusion rates. The mixing appears to result from the patterns of blood flow within the artery, and not from jet effects at the catheter tip.

Whole-blood red blood cell aggregometer for human and feline blood

A whole-blood aggregometer of red blood cells (RBC) is described. It consists of a transparent 0.26-cm ID vinyl tube of approximately 30 cm in length containing freshly drawn heparinized blood and a densitometer head that is attached to the tube. The densitometer head consists of an infrared light source of gallium arsenide and a light detector (silicon photodiode) to monitor changes in optical density of the blood in the tube. The tube and densitometer head were installed in a temperature-controlled box at 37 degrees C. The blood in the tube was first subjected to rapid flow with a solenoid so that the wall shear rate of the blood was approximately 500 s-1. The shear gave rise to a rapid increase in optical density of the blood due to dispersion of the blood corpuscles. The blood was then brought abruptly to a full stop. After the flow had stopped the densitometer head revealed a gradual decrease in optical density in association with RBC aggregate formation. The resultant pattern was termed by us an “RBC aggregogram.” The RBC aggregogram exhibited an exponential decay in its initial part, which was followed by an asymptotic decrease. A simple mathematical procedure was employed to calculate the rate constant of the initial decrease from the two values on the RBC aggregogram at 10 and 20 s. The rate constant k10 was 0.192 +/- 0.028 (5.2 s as time constant; 3.6 s as half time) for feline blood and 0.129 +/- 0.012 (7.7 s as time constant; 5.3 s as half time) for human blood. The RBC aggregation rate varied linearly with the hematocrit below 40%.