Given an abstract, indicate which of the provided candidate titles (Option1 and Option2) best describes it (respond with the text of the title, not option1/2).

Ex Input:
Abstract: We studied thyroid growth-blocking activity in immunoglobulin G (IgG) fractions of serum from 24 patients with primary myxedema, 24 patients with goitrous Hashimoto's thyroiditis, and 18 normal subjects by measuring the ability of their IgG to inhibit TSH-induced [3H]thymidine incorporation into DNA in a rat thyroid cell line, FRTL-5. Both groups of patients were receiving T4 when studied. [3H]Thymidine incorporation induced by 0.1 mU/ml bovine TSH was significantly inhibited by the addition of 2 mg/ml IgG from patients with primary myxedema (P less than 0.01), while it was not affected by IgG from the normal subjects or 23 of the 24 patients with goitrous Hashimoto's thyroiditis. IgG from patients with primary myxedema also inhibited the [3H]thymidine incorporation induced by Graves' IgG, but not that induced by forskolin, cholera toxin, (Bu)2cAMP or phorbol-12-myristate-13-acetate. The inhibition of TSH-induced [3H]thymidine incorporation by IgGs from patients with primary myxedema was significantly correlated with their inhibitory activities against both TSH-induced cAMP generation and TSH binding (P less than 0.001). These data indicate that these growth-blocking antibodies are directed against the TSH receptor and might be one of the causes of the thyroid atrophy in patients with primary myxedema.
Which is the apt title for the abstract? option1: Inhibition of thyrotropin-induced growth of rat thyroid cells, FRTL-5, by immunoglobulin G from patients with primary myxedema. option2: Compressive neuropathy in childhood: a report of 14 cases.

Ex Output:
Inhibition of thyrotropin-induced growth of rat thyroid cells, FRTL-5, by immunoglobulin G from patients with primary myxedema.

Ex Input:
Abstract: Frozen cryosections, 8 microns thick, were cut parallel to the surface of porcine skin so as to provide separate samples representing various epidermal layers. These samples were dried, extracted with chloroform-methanol mixtures, and the lipids chromatographed on silica gel plates in different solvent systems. After spraying with sulfuric acid and charring, lipids were quantified using a scanning densitometer. It was thus possible to determine lipid concentrations in 12 consecutive epidermal layers, extending 96 microns into the skin. The phospholipids that were characterized all decreased in concentration toward the surface, whereas the neutral lipids and ceramides all increased. Glucosylceramide and acylglucosylceramide reached a peak concentration in the stratum granulosum and then decreased in the surface layers. Cholesterol sulfate reached a maximum concentration in the deeper stratum corneum and then abruptly decreased in the surface layer. These changes in patterns of lipid concentration are consistent with current theories regarding the formation of a water barrier in the stratum corneum that is composed mainly of neutral lipids, and with a possible function of cholesterol sulfate in cellular adhesion in the stratum corneum.
Which is the apt title for the abstract? option1: Variations in lipids in different layers of porcine epidermis. option2: Monoclonal patent. Hybritech versus Abbott [news]

Ex Output:
Variations in lipids in different layers of porcine epidermis.

Ex Input:
Abstract: These studies were designed to characterize constitutive steroidogenesis in Leydig tumor cells. Constitutive steroidogenesis was investigated by comparing constitutively active R2C Leydig tumor cells to trophic hormone-responsive MA-10 Leydig tumor cells. Unlike the MA-10 cells, R2C cells appeared to synthesize steroid hormones independently of the cAMP-protein kinase pathway. Although the adenylate cyclase of R2C cells could be stimulated in the expected manner by cholera toxin, cAMP concentrations in these cells were low, and R2C cell steroidogenesis could be dissociated from other cAMP-dependent processes. Two cAMP-dependent processes in steroidogenic cells, protein kinase activation and lactate formation, showed low basal activities in R2C cells and could be stimulated by (Bu)2cAMP with a dose dependence similar to that detected in MA-10 cells. Steroid hormone biosynthesis parallelled these other cAMP-dependent processes in MA-10 cells, but not in R2C cells. Cycloheximide, however, caused similar dose-dependent inhibition of steroidogenesis in both the R2C and MA-10 cells. Using a cell component bioassay, it was shown that R2C cells constitutively synthesize an extramitochondrial cycloheximide-sensitive factor that is functionally identical to the factor produced in response to hCG in MA-10 cells. This factor enhanced mitochondrial pregnenolone biosynthesis. Thus, constitutive steroidogenesis in R2C cells could be explained by the cAMP-independent but cycloheximide-sensitive constitutive production of an extramitochondrial factor that activated mitochondrial pregnenolone biosynthesis.
Which is the apt title for the abstract? option1: Constitutive steroidogenesis in the R2C Leydig tumor cell line is maintained by the adenosine 3',5'-cyclic monophosphate-independent production of a cycloheximide-sensitive factor that enhances mitochondrial pregnenolone biosynthesis. option2: Sex-specific criteria for interpretation of thallium-201 myocardial uptake and washout studies.

Ex Output:
Constitutive steroidogenesis in the R2C Leydig tumor cell line is maintained by the adenosine 3',5'-cyclic monophosphate-independent production of a cycloheximide-sensitive factor that enhances mitochondrial pregnenolone biosynthesis.