Liquid crystal thermography. A new tool for evaluating low back pain.

Liquid crystal thermography was used to determine low back skin temperature patterns in 62 patients hospitalized for low back pain and 22 college volunteers with no previous history of back pain. The patients were separated into four groups according to their diagnoses at discharge: patients with 1) degenerative discogenic lesions, 2) acquired lesions, 3) congenital and developmental lesions, 4) back pain resulting from unknown causes. No significant differences were found between the average equilibrated thermogram temperatures of the control subjects (32.4 +/- 0.5 degrees C) and patient groups. However, the temperature gradients found on the thermograms of patients with discogenic lesions (3.1 +/- 0.6 degrees C) and acquired lesions (3.1 +/- 1.0 degrees C) were significantly greater (p less than .05) than those of the pain-free subjects (2.5 +/- 0.5 degrees C). Tenderness to palpation was associated with elevated skin temperatures in 80 percent of the patients studied. This study suggests that liquid crystal thermography may be a potentially useful tool for localizing soft tissue trauma in patients with low back pain.

A soluble cadmium-binding component in rat and dog spleen.

The spleens of cadmium-treated Sprague-Dawley rats and mongrel dogs were examined for cytoplasmic soluble cadmium-binding moieties following the cessation of parenteral cadmium exposure. Cell homogenates prepared in 0.25M sucrose were centrifuged at 29,000 g and the supernatant fractionated on a fractionating column (Sephadex G-75). Ultraviolet absorbing peaks that showed characteristically high 250-nm to 280-nm absorbences were further analyzed for cadmium content by atomic absorption spectrophotometry. Cadmium-binding fractions isolated from the spleens of both species were characteristically similar to rat kidney metallothionein-like substances isolated and identified by the same procedure. Molecular weights for the canine and rat spleen cadmium-binding components were estimated at 14,783 +/- 343 and 13,916 +/- 490, respectively. These preliminary data indicate the production and persistence of soluble metallothionein-like substances in spleen that bind and retain cadmium ions long after cadmium exposure has ceased.

Cadmium deposition in canine heart and major arteries following intravascular administration of cadmium chloride.

The examination of ten arterial specimens from nine experimental dogs shows a generally persistent accumulation of cadmium in the blood vessels following acute cadmium exposure. Gel filtration analysis of the aorta revealed that this vascular cadmium is largely confined to the insoluble cellular compartment. The left and right ventricles of cadmium-treated dogs showed a cadmium deposition which significantly decreased over the five week period subsequent to exposure. Within all three time intervals, heart cadmium exceeded the level in any of the arteries examined. Control heart, renal and subclavian arteries, and ascending and thoracic aorta were all found to contain intrinsic cadmium. Of the arterial specimens examined, cadmium deposition was generally greatest in the renal arteries and lowest in the femoral and popliteal arteries.