instruction:
Given a passage with a context and an answer, 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.
question:
Context: Parkinsonian signs, especially gait impairment, are common and associated with morbidity and mortality in older persons. Our objective was to test the hypothesis that substantia nigra neurofibrillary tangles (NFTs) are related to parkinsonian signs in older persons with and without dementia.', "We studied 86 deceased older Catholic clergy without idiopathic Parkinson's disease from the Religious Order Study, a longitudinal clinical-pathological study. Mean age at death was 85.3 years. Signs of gait disturbance, bradykinesia, rigidity, and tremor were assessed proximate to death using a modified Unified Parkinson's Disease Rating Scale. Forty-micrometer paraffin-embedded sections of substantia nigra were bleached before tau immunohistochemistry and the optical disector was used to count NFTs. We used multivariable linear regression to examine parkinsonian signs as a function of nigra NFTs, controlling for age, sex, education, and cortical NFTs.", 'Substantia nigra NFTs were present in 67 of 86 persons (77.9%). After controlling for age, sex, education, and cortical NFTs, nigra NFTs were related to gait impairment (p < 0.001), but not bradykinesia, rigidity, or tremor. Results were not confounded by dementia, Braak score, neuroleptic medication, cerebral infarcts, or Lewy bodies.
Answer: NFTs in the substantia nigra are associated with gait impairment in older persons with and without dementia.
answer:
Are substantia nigra tangles related to gait impairment in older persons?


question:
Context: Complications after immediate breast reconstruction pose a significant challenge to the reconstructive surgeon. Known risk factors include smoking, obesity, age, and adjuvant oncologic therapies. Less is known about the association between axillary lymph node dissection (ALND) and the development of postoperative complications.', 'We conducted a retrospective study of all patients who underwent immediate breast reconstruction after mastectomy at our institution over a 10-year period. Our outcome was an occurrence of a major complication within 90 days postoperatively. For each patient, we recorded data on demographics, smoking status, pertinent medical history, reconstruction type, adjuvant chemotherapy and radiation, tumor pathology, and whether an ALND was performed. Odds ratios (OR) were calculated to estimate the risk of a complication if an ALND was performed.', 'One hundred eighty-four women, with 270 surgically treated breasts, were identified as having mastectomy with immediate reconstruction between 2002 and 2012. Mean age was 49.4 years (range, 25-84 years). There were 71 mastectomies with ALND performed, with 22 complications, and 199 mastectomies without ALND, with 20 complications (31% complication rate vs 10%, respectively; OR, 3.84; P < 0.001). When adjusted for reconstruction type, smoking history, obesity, age, presence of invasive disease, chemotherapy, and radiation therapy, the OR for complications was 3.49 (P < 0.01). The most common complication was infection in both groups.
Answer: Mastectomy with ALND is associated with a 3-fold increase in risk of major complications in women undergoing immediate breast reconstruction, even after adjustment for known risk factors and confounders. Further studies are warranted to elucidate how ALND leads to these complications and what measures can reduce their occurrence.
answer:
Does axillary Lymph Node Dissection be a Risk Factor for Major Complications After Immediate Breast Reconstruction?


question:
Context: The purpose of this study was to evaluate the impact of a modified sagittal split osteotomy (SSO) surgical technique on the incidence of persisting inferior border defects. The secondary aim was to identify risk factors associated with the development of these complications.', 'The patient charts and radiographs of 276 consecutive patients who underwent bilateral SSO, performed by a single surgeon in 2 different centers from July 2012 to September 2014, were retrospectively examined. The predictor variable was length of advancement. The outcome variable was the presence or absence of an inferior border defect. Other variables included age and side of the jaw. In all cases the same surgical technique was used. All statistical analyses were performed using SAS software, version 9.4 (SAS Institute, Cary, NC).', 'The analysis included 408 operation sites in 204 patients (132 female and 72 male patients; median age, 22\xa0years; age range, 13 to 66\xa0years). In 5.1% of operation sites an osseous defect at the lower border of the mandible was observed. Age at the time of surgery (P < .0001) and length of advancement (P\xa0= .0111) were identified as risk factors for the development of a persisting osseous defect at the inferior border of the osteotomy gap after SSO.
Answer: This study confirms the findings previously reported by our research group that the modified inferior border osteotomy technique in SSO results in a substantial lower frequency of persisting inferior border defects. Surgeons are advised to ensure that the lingual cortex of the inferior border is not included in the split during mandibular advancements, and in cases in which the advancement is more than 10 mm and/or the patient is older than 30 years, surgeons might want to consider using a bone graft or a bone graft substitute.
answer:

Does modified Mandibular Inferior Border Sagittal Split Osteotomy reduce Postoperative Risk for Developing Inferior Border Defects?