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.

Context: rs1333049 polymorphism on chromosome 9p21 has been shown to affect susceptibility to coronary artery disease (CAD) in Caucasians. This study examined the association of rs1333049 with myocardial infarction (MI), angiographic severity of CAD and clinical outcome after a first acute MI in Han Chinese.', 'rs1333049 polymorphism was genotyped in 520 patients with a first acute MI and in 560 controls. The number of angiographically documented diseased coronary arteries (luminal diameter stenosis > or = 50%), echocardiographic left ventricular ejection fraction (LVEF), and major adverse cardiac events (MACE) during follow-up (mean, 29+/-15 months) were recorded.', 'Patients with MI had higher frequencies of the CC genotype (30.0% vs. 20.7%) or C allele (55.5% vs. 46.2%) compared with controls (all p<0.01). rs1333049 polymorphism was strongly associated with MI [odds ratio (OR) 1.48, 95% confidence interval (CI) 1.22-1.79] after adjusting for traditional risk factors. Although longer hospitalization stay was observed in patients with the rs1333049-C allele, this polymorphism was not related to angiographic severity of CAD, LVEF, and occurrence of MACE after MI.\Question: Is chromosome 9p21 polymorphism associated with myocardial infarction but not with clinical outcome in Han Chinese?
This study demonstrates an association of rs1333049 polymorphism locus on chromosome 9p21 with risk for MI, but not with post-MI prognosis in Han Chinese.

Context: The aim of this study was the analysis of total, early and late complications following venous access port implantation between 1998 and 2008 at the Department of Surgery of the University of Rostock, Germany. A comparison between different implantation techniques addressing success rate, complication rate and duration of operation was performed. These results were further analysed in regard to the level of training of the participating surgeons.', 'A retrospective analysis of 1423 venous access port implantations between 1998 and 2008 was performed.', "The rate of total complications was 13.8%. Among 4.7% early complications pneumothorax was the most common. The rate of late complications was 9.1%. Most common were infection (4.9%) followed by dysfunction of the catheter (3.5%). 1322 venous access port implantations were performed using puncture of the subclavian vein and Seldinger's technique. 101 operations were performed by direct access through dissection of the cephalic vein and open introduction of the catheter. Operation time in the open group was significantly longer than in the puncture group (46.5\u2009min vs. 38.7\u2009min, p\u2009=\u20090.005). There were significantly more late complications (9.6% vs. 2%, p\u2009=\u20090.01) and total complications (14.5% vs. 4%, p\u2009=\u20090.005) in the puncture group vs. the open access group. Primary success rates of open access vs. puncture were 100% and 96.8%, respectively. The rate of complications was independent of the experience status of the surgeon. However, the rate of total and late complications significantly decreases with number of performed operations.\Question: Is [ Venous Access Port Implantation an Ideal Teaching Operation - An Analysis of 1423 Cases ]?
Venous port implantation is a relatively simple procedure despite its possible complications. An open access technique is safer than puncture. The rate of complications significantly decreases with increasing number of performed operations. Therefore venous port implantation and especially the open access method is an ideal teaching operation in a structured surgical training programme.

Context: The physiological basis of slow transit constipation (STC) in children remains poorly understood. We wished to examine pan-colonic motility in a group of children with severe chronic constipation refractory to conservative therapy.', 'We performed 24 h pan-colonic manometry in 18 children (13 boys, 11.6 +/- 0.9 yr, range 6.6-18.7 yr) with scintigraphically proven STC. A water-perfused, balloon tipped, 8-channel, silicone catheter with a 7.5 cm intersidehole distance was introduced through a previously formed appendicostomy. Comparison data were obtained from nasocolonic motility studies in 16 healthy young adult controls and per-appendicostomy motility studies in eight constipated children with anorectal retention and/or normal transit on scintigraphy (non-STC).', 'Antegrade propagating sequences (PS) were significantly less frequent (P < 0.01) in subjects with STC (29 +/- 4 per 24 h) compared to adult (53 +/- 4 per 24 h) and non-STC (70 +/- 14 per 24 h) subjects. High amplitude propagating sequences (HAPS) were of a normal frequency in STC subjects. Retrograde propagating sequences were significantly more frequent (P < 0.05) in non-STC subjects compared to STC and adult subjects. High amplitude retrograde propagating sequences were only identified in the STC and non-STC pediatric groups. The normal increase in motility index associated with waking and ingestion of a meal was absent in STC subjects.\Question: Does 24-Hour colonic manometry in pediatric slow transit constipation show significant reductions in antegrade propagation?

Prolonged pancolonic manometry in children with STC showed significant impairment in antegrade propagating motor activity and failure to respond to normal physiological stimuli. Despite this, HAPS occurred with normal frequency. These findings suggest significant clinical differences between STC in children and adults.