In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

[Q]: Context: Hepatic osteodystrophy has been reported in patients with various chronic liver diseases, including liver cirrhosis. However, it has not been well investigated in patients with hepatitis B virus infection. The aim of this study was to investigate the association between hepatitis B surface antigen (HBsAg) seropositivity and bone mineral density (BMD) in a population representative of normal Koreans.', 'Subjects with both HBsAg and BMD levels examined during the 2008-2010 Korea National Health and Nutrition Examination Surveys were included. HBsAg-seropositive (+) subjects were compared with those who were HBsAg-seronegative (-). BMD was measured at the lumbar spine and femur by dual-energy X-ray absorptiometry. Multivariable logistic regression was performed for BMD .', 'In total, 11,306 participants were included in this study, among which 423 (3.7\xa0%) were HBsAg(+): 153 premenopausal female (3.4\xa0%), 83 postmenopausal female (3.5\xa0%), and 187 male (4.2\xa0%). Multivariable logistic regression analysis adjusted for age and body mass index showed that HBsAg(+) male had significantly lower BMD of the femoral neck than HBsAg(-) male (0.810\xa0±\xa00.009 vs. 0.827\xa0±\xa00.002\xa0g/cm(2), p\xa0=\xa00.035). Further adjustment for waist circumference, smoking, drinking, exercise, income, occupation, and vitamin D levels showed that HBsAg(+) male had significantly lower BMD of the femur neck (0.810\xa0±\xa00.010 vs. 0.831\xa0±\xa00.002\xa0g/cm(2), p\xa0=\xa00.032) and lumbar spine (0.953\xa0±\xa00.011 vs. 0.974\xa0±\xa00.003\xa0g/cm(2), p\xa0=\xa00.049) than HBsAg(-) male.\Question: Are males seropositive for hepatitis B surface antigen at risk of lower bone mineral density : the 2008-2010 Korea National Health and Nutrition Examination Surveys?
[A]: HBsAg seropositivity was significantly associated with lower BMD in male. Future long-term prospective studies investigating bone turnover markers and hormones are needed to better understand the pathophysiology and clinical significance of chronic hepatitis B virus-related hepatic osteodystrophy.


[Q]: Context: Cognitive impairment is a common feature of late-life bipolar disorder (BD). Yet, there is limited information on the biological mechanisms associated with this process. It is uncertain whether cognitively impaired patients with BD may present the Alzheimer's disease (AD) bio-signature in the cerebrospinal fluid (CSF), defined as a combination of low concentrations of the amyloid-beta peptide (Aβ1-42 ) and high concentrations of total tau (T-tau) and tau phosphorylated at threonine 181 (P-tau). In this study, we sought to determine whether cognitive impairment in elderly patients with BD is associated with the AD CSF bio-signature.", 'Seventy-two participants were enrolled in the study. The test group comprised older adults with BD and mild cognitive impairment (BD-MCI; n\xa0=\xa016) and the comparison groups comprised patients with dementia due to AD (n\xa0=\xa017), patients with amnestic MCI (aMCI; n\xa0=\xa014), and cognitively healthy older adults (control group; n\xa0=\xa025). CSF samples were obtained by lumbar puncture and concentrations of Aβ1-42 , T-tau and P-tau were determined.', 'CSF concentrations of all biomarkers were significantly different in the AD group compared to all other groups, but did not differentiate BD-MCI subjects from aMCI subjects and controls. BD-MCI patients had a non-significant reduction in CSF Aβ1-42 compared to controls, but this was still higher than in the AD group. Concentrations of T-tau and P-tau in BD-MCI patients were similar to those in controls, and significantly lower than those in AD.\Question: Is cognitive impairment in late-life bipolar disorder associated with Alzheimer 's disease pathological signature in the cerebrospinal fluid?
[A]: Cognitively impaired patients with BD do not display the so-called AD bio-signature in the CSF. We therefore hypothesize that cognitive deterioration in BD is not associated with the classical pathophysiological mechanisms observed in AD, i.e., amyloid deposition and hyperphosphorylation of microtubule-associated tau protein.


[Q]: Context: Contralateral groin exploration in children with unilateral inguinal hernia is still controversial, particularly in infants. The patency rate of processus vaginalis is highest in infants but there are few data on the subsequent risk of contralateral hernia development in infants. In this retrospective study, we aimed to find out the incidence of contralateral inguinal hernia following unilateral inguinal herniotomy in infants aged less than one year.', 'All infants who underwent a unilateral Inguinal herniotomy between January 1990 and December 1998 were studied retrospectively. Infants with bilateral hernia (n = 7) were excluded from the study.', 'One hundred and one infants (93 boys and 8 girls) were studied. Median age at operation was 23 (range 2-52) weeks. The herniotomy was right-sided in 75% of the infants. Follow-up ranged from three and a half years to 11 years. A contralateral hernia developed in nine infants (9.0%). One of the initial hernias was incarcerated. Median time from operation to occurrence of contralateral hernia was 18 (range 2-60) months. None of the contralateral hernia was incarcerated. Age, sex, incarceration and side of initial hernia did not influence the development of contralateral hernia.\Question: Is contralateral groin exploration justified in infants with a unilateral inguinal hernia?
[A]:
The low incidence and benign nature of contralateral hernia development in infants undergoing a unilateral inguinal herniotomy does not justify routine contralateral groin exploration.