Effect of ketosis on respiratory sensitivity to carbon dioxide in obesity.

We investigated whether the respiratory defect in the obesity-hypoventilation syndrome might respond to dietary manipulation. The effects of hypocaloric ketogenic regimens on the ventilatory response to carbon dioxide were studied in a manner excluding changes in weight or thoracic mechanics as factors. Six obese subjects with hyporesponse (less than 1.1 1/min/mm Hg) and 12 with normal response were fasted or given a diet containing 400 kcal per day of protein. During ketosis carbon dioxide response more than doubled in those with hyporesponse (0.8 +/- 0.1 to 1.8 +/- 1/min/mm Hg, P less than 0.05) but was unchanged in those with normal response. This improvement could not be accounted for by changes in weight, pulmonary function, pH or degree of ketosis between the two groups. However, a significant positive (r = 0.70; P less than 0.001) correlation between ketone-body concentrations and carbon dioxide response was observed in subjects with hyporesponse. These results indicate that depressed sensitivity to carbon dioxide in obese patients can be increased by dietary manipulation.     

Microtubular inclusions in normal skin of systemic lupus erythematosus patients

Biopsy specimens of clinically normal skin of 9 consecutive patients with SLE were examined ultrastructurally to determine the presence and frequency of microtubular inclusions. Ten blood vessels were examined in each specimen; every specimen contained at least two positive blood vessels, and some contained 80 to 100% positive vessels. No correlation was found between the frequency of the inclusions and either the disease duration or antinuclear factor titer. The inclusions tended to be more frequent in patients with more acute disease. The absence of inclusions in normal skin may mitigate a diagnosis of SLE.