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 Q]: Abstract: Faecal metronidazole and hydroxymetronidazole concentrations measured by high pressure liquid chromatography are reported during 10 episodes of Clostridium difficile colitis in nine patients. Bactericidal faecal concentrations were present in all patients with acute disease receiving oral or intravenous metronidazole, and all responded to therapy. Metronidazole and hydroxymetronidazole concentrations fell as the diarrhoea improved and neither substance was detectable in the faeces of five patients after recovery. This demonstration of intracolonic therapeutic concentrations of metronidazole supports the clinical experience of oral metronidazole being effective in the treatment of antibiotic associated diarrhoea caused by C difficile and also suggests a potential role for intravenous metronidazole in this disease.
Which is the apt title for the abstract? option1: Faecal metronidazole concentrations during oral and intravenous therapy for antibiotic associated colitis due to Clostridium difficile. option2: Planning for the health care needs of patients with AIDS [editorial]
[EX A]: Faecal metronidazole concentrations during oral and intravenous therapy for antibiotic associated colitis due to Clostridium difficile.

[EX Q]: Abstract: Microcephaly and its etiology were studied in an unselected Swedish urban infant population. Virtually, all live-born infants (14,724) born between October 1977 and December 1983 in the city of Malmo, Sweden, were included in the study. Special attention was given to the role of congenital infections, particularly to cytomegalovirus infection. The infant population was studied from two points of view. One part of the study was prospective and based on regular cytomegalovirus isolation in urine within the first week of life. About 80% of the newborns were adequately studied by this test. None of 56 infants shown to be cytomegalovirus excreters (congenitally infected) and followed up were born with or developed microcephaly (head circumference smaller than 3 SD below the mean for age and sex) during the first 1 to 7 years of life. However, two of the 56 infants had a head circumference of -2 SD. In the beginning of 1985, an inventory was made of the presence of symptomatic microcephaly in the above mentioned population still living in the city or deceased there. Of about 10,000 such children, 12 were found to have symptomatic microcephaly. By studies of personal, clinical, and laboratory data and by retrospective serologic studies of frozen pre- and postconceptional maternal sera, a possible explanation or a recognized syndrome was obtained in ten of the 12 cases. In one of them, the mother had a primary cytomegalovirus infection, possibly in early pregnancy. Although the infant had symptoms compatible with a congenital infection, no laboratory evidence of transmitted infection was found. In no case were congenital rubella virus or Toxoplasma gondii infections suspected.
Which is the apt title for the abstract? option1: Microcephaly and congenital cytomegalovirus infection: a combined prospective and retrospective study of a Swedish infant population. option2: Partial splenectomy using the TA stapler.
[EX A]: Microcephaly and congenital cytomegalovirus infection: a combined prospective and retrospective study of a Swedish infant population.

[EX Q]: Abstract: Several recent reports have addressed the problem of estimating the response slope from repeated measurements of paired data when both stimulus and response variables are subject to biological variability. These earlier approaches suffer from several drawbacks: useful information about the relationships between the error components in a closed-loop system is not fully utilized; the response intercept cannot be directly estimated; and the normalization procedure required in some methods may fail under certain circumstances. This paper proposes a new, general method of simultaneously estimating the response slope and intercept from corrupted stimulus-response data when the errors in both variables are specifically related by the system structure. A direct extension of the least-squares approach, this method [directed least squares (DLS)] reduces to ordinary least-squares methods when either of the measured variables is error free and to the reduced-major-axis (RMA) method of Kermack and Haldane (Biometrics 37: 30-41, 1950) when the magnitudes of the normalized errors are equal. The DLS estimators are scale invariant, statistically unbiased and always assume the minimum variance. With simple modifications, the method is also applicable to paired data. If, however, the relation between error components is uncertain, then the RMA method is optimal, i.e., having the least possible asymptotic bias and variance. These results are illustrated by using various types of closed-loop respiratory response data.
Which is the apt title for the abstract? option1: Estimation of response curves in closed-loop physiological control. option2: Increased porphobilinogen deaminase activity in patients with malignant lymphoproliferative diseases. A helpful diagnostic test.
[EX A]:
Estimation of response curves in closed-loop physiological control.