Allergic alveolar diseases. Problems in diagnosis and management

One of the diagnostic possibilities to consider when a patient presents with cough, fever, dyspnea, or pulmonary infiltrates is hypersensitivity pneumonitis. Some of the problems encountered in diagnosis of diffuse lung disease are illustrated in two case reports. In one of the cases, interstitial pneumonitis of insidious onset was attributed to inhalation of thermophilic organisms in moldy silage. In the other, the outstanding pathologic feature was bronchiolitis obliterans, and circumstantial evidence pointed to a home humidifier as the source of the problem.     

Removal of a bound ligand from a macromolecule by gel filtration

If a solution of macromolecule of concentration c and volume a, initially saturated with a ligand of dissociation constant K, is gel filtered through a volume v of solution initially free of ligand, the saturation y with which it emerges is given by the equation y-lny-1=Kv/ca.     

"Conflicting" motion cues to the visual and vestibular self-motion systems around 0.06 Hz evoke simulator sickness

The basic question this research addressed was, how does simulator sickness vary with simulated motion frequency? Participants were 11 women and 19 men, 20 to 63 years of age. A visual self-motion frequency response curve was determined using a Chattecx posture platform with a VR4 head-mounted display (HMD) or a back-projected dome. That curve and one for vestibular self-motion specify a frequency range in which vestibular and visual motion stimuli could produce conflicting self-motion cues. Using a rotating chair and the HMD, a third experiment supported (p < .01) the hypothesis that conflicting cues at the frequency of maximum "crossover" between the curves (about 0.06 Hz) would be more likely to evoke simulator sickness than would conflicting cues at a higher frequency. Actual or potential applications of this work include a preliminary design guidance curve that indicates the frequency range of simulated motion that is likely to evoke simulator or virtual reality sickness; for simulators intended to operate in this frequency range, appropriate simulator sickness interventions should be considered during the design process.     

Surgical correction of torsion of the penis

Torsion of the penis is a rare anomaly, believed to be due to abnormal skin attachment and not to any structural abnormality of the corpora. The rotation is usually to the left in a counter-clockwise fashion. The urethral meatus is placed in a oblique position and the median raphe makes a spiral curve from the base of the penis towards the meatus. Three boys with congenital torsion of the penis are reported. A corrective operative for this condition is described. Penile torsion was first described by Verneuil in 1857, but in the past no operative correction was recommended, since attempts to move the skin around were believed not to correct the spiral alignment of the corpora cavernosa.     

Liver vitamin A slow release syndrome in cattle with a multiple nutrient imbalance

Data on liver vitamin A concentrations in malnourished, debilitated, down cattle in tropical, northern Australia support the hypothesis that 12% annual cattle mortality was due, in part, to a slow release of liver vitamin A. High Ca and low Zn levels in the legume forage apparently contributed to the slow release. The cattle showed marked sensitivity to sunlight and exhibited problems of sight. The malnourished yearling steers averaged 183.3 micrograms vitamin A/g wet liver vs 152.3 micrograms for steers slaughtered off good green wet season forage. Indications of a slow release of liver vitamin A were that: (1) only 4 to 7 micrograms vitamin A/g liver were in the alcohol fraction or release form; (2) after adjustments for decreases in liver and blood volume in starving animals, blood vitamin A was lowered to 18 micrograms/100 ml, which was low in relation to the adjusted liver vitamin A level of 91.7 micrograms/g, and (3) after adjustments, the liver had released only 1,667 units of vitamin A/day in the dry season, or about 1/4 of maintenance needs. The cattle were grazing a legume forage pasture containing 7.1% protein and no measurable carotene. The forage was deficient in Zn (25 ppm), which would slow the release of liver vitamin A. High Ca levels in the legume forage (.4 to .54%) in combination with low P levels (.11 to .18%) would further aggravate the low Zn level.