Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

[Q]: Despite much clinical experience, there are few published accounts of the surgical manifestations of HIV/AIDS in children and still fewer guidelines for the best or most appropriate treatment. Our primary objective was to document the incidence of HIV infection in children who presented with a surgical emergency to a major pediatric surgical unit in South Africa. If possible, we aimed to provide a description of the impact of the disease in a surgical pediatric population and to raise awareness of the mode of presentation of HIV to the pediatric surgeon in a developing nation, now that specific antiretroviral therapies are available.', 'This was a prospective observational study of consecutive surgical emergency admissions to the Division of Paediatric Surgery at the University of the Witwatersrand, Johannesburg, South Africa, between April 1 and May 31, 2005. Consent for inclusion in the study was sought in all cases. The clinical profile of children presenting during the study period was recorded. If relevant, permission was sought from the parent/guardian to undertake HIV status testing if this were not already known.', 'Three hundred ninety-one children were admitted as emergency cases during the study period. Thirty-seven (9.5%) of 391 were excluded, because consent could not be obtained, leaving 354 children. Ages ranged between 1 day and 17 years, with a median age of 3 years. The diagnosis in most was trauma/burns (42%) and abdominal emergencies (27%). Infections occurred in 13% of these patients. Human immunodeficiency virus status was already known in 10 (3%) of 354 patients, and only 18 (5%) of 344 children were tested; of these, 10 (55%) were positive. As expected, the predominant surgical presentation of HIV positive children was sepsis. The prevalence of HIV/AIDS in those children not tested is unknown.
[A]: Are surgeons failing to recognize children with HIV infection?


[Q]: Restoration of posterior condylar offset during TKA is believed to be important to improving knee kinematics, maximizing ROM, and minimizing flexion instability. However, controversy exists regarding whether there are important anatomic differences between sexes and whether a unisex knee prosthesis can restore the anatomy of knees in males and females.', 'The purposes of our study were to determine if sex differences exist in (1) absolute posterior condylar offset size, (2) relative posterior condylar offset size in relation to total condylar height, and (3) posterior condylar articular cartilage thickness.', 'We identified 100 patients (50 men and 50 women) without a history of arthritis, deformity, dysplasia, osteochondral defect, fracture, or surgery about the knee who had MRI of the knee performed. All MR images were ordered by primary care medical physicians for evaluation of nonspecific knee pain. Using a previously described three-dimensional MRI protocol, we measured posterior condylar offset, total condylar height, and articular cartilage thickness at the medial and lateral femoral condyles and compared values to evaluate for potential sex differences. We performed an a priori power calculation using a 2-mm posterior condylar offset difference as the minimum clinically important difference; with 2n = 100, our power to detect such a difference was 99.8%.', 'Compared with females, males had greater medial posterior condylar offset (30 mm [95% CI, 29.3-30.7 mm; SD, 2.5 mm] vs 28 mm [95% CI, 27.0-28.5 mm; SD, 2.7 mm]), lateral posterior condylar offset (27 mm [95% CI, 26.2-27.3 mm; SD, 2.0 mm] vs 25 mm [95% CI, 24.2-25.4 mm; SD, 2.0 mm]), medial condylar height (63 mm [SD, 3.2 mm] vs 57 mm [SD, 4.4 mm]), and lateral condylar height (71 mm [SD, 5.2 mm] vs 65 mm [SD: 4.0 mm]) (all p values < 0.001). However, the mean ratio of medial posterior condylar offset to medial condylar height (0.48 [SD, 0.04] vs 0.49 [SD, 0.05]) and the mean ratio of lateral posterior condylar offset to lateral condylar height (0.38 [SD, 0.05] vs 0.38 [SD, 0.03]) were not different between sexes (p = 0.08 and p = 0.8, respectively). There also was no sex difference in mean articular cartilage thickness at either condyle (medial condyle: 2.7 mm [SD, 0.5 mm] vs 2.5 mm [SD, 0.7 mm]; lateral condyle: 2.6 mm [SD, 0.6 mm] vs 2.5 mm [SD, 0.8 mm]) (both p values ≥ 0.1).
[A]: Do no sex differences exist in posterior condylar offsets of the knee?


[Q]: Epidermal growth factor (EGF) has been shown to induce intestinal proliferation and maturation; however, little information is available regarding substrates of the intestinal EGF receptor tyrosine kinase. The purpose of this study was to determine if src homologous collagen-like protein (Shc) was an in vivo substrate of the intestinal EGF receptor.', 'Ten-day-old rats were treated with EGF or were breast-fed. In some experiments, IEC-6 cells were treated with EGF. Intestinal tissue and cell fractions were studied by immunodetection to compare the tyrosine phosphorylation state and the subcellular localization of intestinal proteins.', 'The total tyrosine phosphorylation state of intestinal proteins was increased threefold by EGF. Tyrosine phosphorylation of the EGF receptor and Shc were rapidly increased by EGF. The association of Grb2 with Shc increased fourfold and fivefold. Plasma membrane translocation of Shc and associated phosphotyrosyl proteins was increased within 30 seconds of EGF treatment.
[A]:
Is shc a substrate of the rat intestinal epidermal growth factor receptor tyrosine kinase?