Spontaneous fistula formation as a complication of relaxing incisions with suture placement for postkeratoplasty high astigmatism

A 39-year-old man had a corneal relaxing incision with corneal compression suture placement to correct more than 10 diopters of corneal astigmatism. A permanent fistula formed from the compression suture, resulting in a localized corneal pocket of aqueous that broke through the surface. The aqueous drained into the tear film, requiring major surgical repair.     

Mechanical design aspects of the HYVAX railgun

The hypervelocity experiment (HYVAX) railgun (Fig. 1) is designed to produce projectile velocities greater than 15 km/s in a 13-m-long, round bore gun. The HYVAX gun incorporates a modular design enabling it to operate in either a distributed energy-storage mode or a single-stage mode. The gun is composed of seven O.3-m-long power input modules and nine 1.2-m-long accelerating modules. The gun is designed for a 100-shot life. To accommodate this, the bore may be enlarged from an initial diameter of 10.8 mm to a final diameter of 12.7 mm. This will allow the bore to be refinished several times during the life of the gun. To minimize mechanical and arc damage to the gun between bore refinishing operations, the gun will incorporate a low pressure helium projectile injector. Projectiles will be injected under vacuum at 350 m/s. The gun will be operated at a peak current and voltage of 600 kA and 6 kV respectively. The gun will undergo three phases of testing. The first phase will be the characterization of the gun's performance using a 3.0-m-long section of the gun comprising two power modules and two accelerating modules. This testing will be accomplished using two of the seven capacitor bank modules shown in Fig. 1. The second test phase will use a distributed power configuration and seven capacitor bank modules, as shown in Fig. 1, to demonstrate a velocity of 15 km/s with a 1-g projectile. The predicted performance of the gun for this test phase is illustrated in Fig. 2. In the third phase of testing we will use a magnetic flux compression generator (MFCG) to power the gun with a goal of demonstrating a velocity of 25 km/s.     

Results of renal transplantation in boys treated for posterior urethral valves

The results of renal transplantation in boys treated for posterior urethral valves were evaluated and compared with a matched control group. Patient and graft survival was equal in both groups, although serum creatinine levels were slightly higher in the posterior urethral valves group. Postoperative complications, such as urinary tract infections, occurred more frequently in the posterior urethral valves group. Urodynamic evaluation was performed before transplantation in 11 of 20 patients. Adequate treatment of bladder dysfunction, such as poor compliance and/or hyperreflexia, is essential in diminishing the risks of secondary graft damage due to severe bladder dysfunction.     

Virulence and viability of Yersinia pestis 25 years after lyophilization

When equal volumes of 6% lactose and a broth culture of Yersinia pestis were mixed before freezing, approximately 50% of the cells survived lyophilization and reconstitution on the following day. Concomitantly, the number of viable cells per 50% lethal dose increased from about 16 to 125 organisms. On subsequent storage of the lyophilized cells under vacuum in glass ampoules at 4 degrees C for 25 years, more than 25% of the cells remained viable. When stored cultures were assayed immediately after reconstitution, virulence for mice was significantly reduced (as many as 4,000 cells/50% lethal dose), but the virulence was fully restored when reconstituted cultures were held for 24 h at room temperature, or when a subculture was prepared in fresh medium.     

Detachment of the continent ileostomy poucn from the anterior abdominal wall: report of two unusual cases

The cases of two patients with continent ileostomies are presented. These illustrate the problems encountered with detachment of the pouch from the abdominal wall resulting in angulation of the efferent loop of the pouch in relation to the nipple valve and difficulty intubating the pouch. Both patients required operative correction of the separation. Several suggestions are made in order to prevent or decrease the incidence of the complications. Removal of a peritoneal strip around the efferent loop of the pouch appears to facilitate adequate fixation of the pouch to the anterior abdominal wall.