Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

Abstract: Plastic bronchitis is an uncommon disease of children characterized by the formation of long, branching bronchial casts. Of three children with such bronchial casts, one developed status asthmaticus and coughed out a complete cast of the tracheobronchial tree. One other child also had a course of desensitization for allergies. Two children presented with what was originally thought to be pneumonitis, but when chest x-rays were taken, one child was suspected of having an inhaled foreign body, and the other had complete opacification of one lung. When these two children were examined bronchoscopically the tracheobronchial tree was found to be filled with white, cheesy material. This material was extremely hard to remove bronchoscopically as the material was too soft to grab with forceps but too thick to suction. The material extended all the way down into the tertiary bronchi, and in one child multiple bronchoscopies were necessary to remove this material, and even so he developed bronchiectasis. The pathologic examination of these casts showed layers of inspissated mucus and inflammatory cells.
Plastic bronchitis.

Abstract: The transsphenoidal route to the pituitary gland is well established in neurosurgical practice, and several approaches to the sphenoidal air sinus have been described. In this paper, the authors describe a technique that utilizes a direct route through the nasal cavity, thereby minimizing disruption of normal tissues.
A direct transnasal approach to the sphenoid sinus. Technical note.

Abstract: The cross-sectional relationship of endogenous androgens (testosterone, androstenedione, and dehydroepiandrosterone sulfate [DHEA-S]), estrogen (estradiol) and progestin (progesterone) to serum levels of lipoprotein cholesterol (very low-density [VLDL], low-density [LDL], and high-density lipoprotein [HDL]) and apolipoproteins (apo A-I and apo B) were studied in white (n = 251) and black (n = 258) adolescent boys, ages 11 to 17 years, as part of the Bogalusa Heart Study. Black boys had significantly higher levels of estradiol, HDL cholesterol, and apo A-I, and lower levels of androstenedione and VLDL cholesterol than white boys, independent of age and adiposity. Age was correlated strongly with testosterone and androstenedione, and moderately with DHEA-S and estradiol levels in both races. However, only in white boys was age consistently related to VLDL cholesterol (positively), HDL cholesterol (negatively), and apo A-I (negatively). Overall, testosterone was associated inversely with HDL cholesterol and apo A-I in white boys, while progesterone was related positively to apo A-I in both races after adjusting for age and adiposity. However, these relationships were found to differ with age. Partial correlations between levels of sex hormones and lipoproteins adjusted for age and adiposity showed no associations in the 11 to 12 year age group in boys of either race. A significant positive relation of testosterone to VLDL cholesterol, and inverse relations of testosterone to HDL cholesterol and apo A-I and DHEA-S to HDL cholesterol were apparent only in white boys in the 13 to 14 year age group.(ABSTRACT TRUNCATED AT 250 WORDS)
Racial (black-white) comparisons of the relationship of levels of endogenous sex hormones to serum lipoproteins during male adolescence: the Bogalusa Heart Study.