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.

[EX Q]: Context: The BXD2 mouse strain spontaneously develops glomerulonephritis and erosive arthritis. The goal of this study was to identify the antigenic target proteins and epitopes and to unravel the mechanisms by which the related conditions arise in BXD2 mice.', 'Individual hybridomas isolated from the spleen of a 10-month-old BXD2 mouse were injected intraperitoneally into nonautoimmune mice for evaluation of pathogenicity of each autoantibody. Autoantigens were immunoprecipitated with the pathogenic autoantibody L3A4. Autoantigens were identified using enzyme-linked immunosorbent assay, Western blotting, 2-dimensional gel electrophoresis, and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MS) and tandem MS. Antigenic epitopes were determined using a high-throughput epitope mapping method.', 'The production of autoantibodies in BXD2 mice occurred in an orderly progression, with peak levels of autoantibodies to nitrotyrosine (NT)-modified enolase, Ro, alpha-actin, and heat-shock proteins (HSPs) preceding peak levels of antihistone, anti-DNA, and rheumatoid factor. Two monoclonal autoantibodies, L3A4 and T56G10, were identified that could induce immune complexes, renal disease, and/or arthritis. Both L3A4 and T56G10 were polyreactive, and each reacted with separate sets of autoantigens. The antigenic targets of L3A4 consisted of NT-modified enolase, ATP5b, alpha-actin, and Hsp70 family proteins including Hspa5 and Hsp74. The antigenic epitopes of NT-modified enolase and Hspa5 exhibited sequence homology and cross-reactivity, suggesting that epitope spreading may occur through a molecular mimicry mechanism.\Question: Does production of a novel class of polyreactive pathogenic autoantibodies in BXD2 mice cause glomerulonephritis and arthritis?
[EX A]: The polyreactivity of autoantibodies that target a novel class of autoantigens may enable these autoantibodies to induce erosive arthritis or glomerulonephritis either by direct pathogenic mechanisms or indirectly via Fc or immune complex deposition.

[EX Q]: Context: Ventriculo-peritoneal shunting is the most commonly used method for the treatment of paediatric hydrocephalus. The programmable valve with the ability to adjust the opening pressure non-invasively has made it easier to find exactly the right opening pressure for each child and reduce the risk of over- or under-drainage. The aim of this investigation was to study our clinical experience with the adult Codman Hakim programmable valve in children, with reference to complications and economic impact.', 'A seven-year retrospective study of 122 hydrocephalic children (aged from children born prematurely to 15 years old) shunted with the adult Codman Hakim programmable valve was performed.', 'The programmable valve was the first shunt in 76 children and in 14 after prior ventricular drainage. The remaining 46 had different non-programmable systems as their first shunt. The most common reason for changing to a programmable valve was over-drainage. With the programmable valve, catheter-related complications, e.g. proximal (36%) or distal obstructions (30%), were the main reasons for surgical revision. Non-invasive pressure adjustment was performed in 73% of the children. Among the children with the programmable valve as their first shunt, 57 (75%) were adjusted, 12 (21%) had severe symptoms of over-drainage and would have required urgent surgical change of the valve if it had not been adjustable. A resetting of the opening pressure after MRI was found in 38% and accidental resetting occurred in 4%. Programmable valves are about twice as expensive as non-programmable valves. We estimated the increased cost of the valve and compared it with the savings from a reduction in the number of re-operations. The total cost for the programmable valve (as the primary shunt) in our study was less than that for expected re-operations due to over- or under-drainage when using non-programmable valves.\Question: Is the programmable adult Codman Hakim valve useful even in very small children with hydrocephalus . A 7-year retrospective study with special focus on cost/benefit analysis?
[EX A]: The programmable valve was easy to handle; only one size was required and the adjustment made it possible to achieve an optimal intraventricular pressure with a lower total cost, reduced hospital stay as well as an increased quality of life for the children.

[EX Q]: Context: Back pain is among the most prevalent pain disorders causing chronic disability among adults, and insomnia is a common co-morbidity. However, whether insomnia precedes back pain or vice versa remains unclear. The current study tested the temporal association between insomnia and back pain.', 'A longitudinal design was used to investigate whether changes in insomnia over time predict the onset of back pain and vice versa. The study was conducted on a cohort of active healthy working adults (N = 2,131, 34% women) at three time points (T1, T2, and T3) over a period of 3.7 years (range = 2.2-5.12) years. Logistic regression analysis was used to test whether increased insomnia symptoms from T1 to T2 predicted the onset of new back pain. Ordinary least squares regression was used to test whether the existence of back pain at T2 predicted an increase in insomnia from T2 to T3.', 'The results indicated that after controlling for socioeconomic variables, self-reported health, lifestyle behaviors, and anthropometrics, a T1-T2 increase in insomnia symptoms was associated with a 1.40-fold increased risk of back pain at T3 (OR = 1.40; 95% CI = 1.10-1.71). No support was found for reverse causation; i.e., that back pain predicts subsequent increase in insomnia.\Question: Do increased insomnia symptoms predict the onset of back pain among employed adults?
[EX A]:
Insomnia appears to be a risk factor in the development of back pain in healthy individuals. However, no evidence of reverse causation was found.