Synthetic Assembly of Bifluorescence-Labeled Glycopolymers as Substrates for Assaying α-Amylase by Resonance Energy Transfer

To meet the need for a convenient substrate for sensitive and continuous assay for α-amylase, we developed a fluorescence resonance energy transfer (FRET)-based polymer substrate. Radical copolymerization of FRET-component monomers in different ratios of fluorogenic donor and acceptor was utilized to prepare such polymers. A glycomonomer as a fluorogenic donor was derived from naphthylmethylated maltotetraose, and a dansyl derivative monomer was used as an acceptor. Their mixture and acryl amide were copolymerized in a typical radical polymerization to yield a bifluorescence-labeled polymer in good yield. All of the polymers showed effective FRET and were used for the continuous assay of human salivary α-amylase. The time course of α-amylase reactions led to the apparent kinetic parameters of <i>K</i>_m = 4 μM and <i>V</i>_max = 0.29 nmol/min. The results strongly suggested that FRET-sensitive polymers are conveniently accessible and applicable for the sensitive determination of biochemical events

The associations between magnetic resonance imaging findings and low back pain: A 10-year longitudinal analysis

<div><p>Purpose</p><p>To conduct a 10-year longitudinal analysis of the relationship between magnetic resonance imaging (MRI) findings and low back pain (LBP).</p><p>Materials and methods</p><p>Ninety-one volunteers with a history of LBP, but without current LBP were recruited between 2005 and 2006. Participants’ baseline demographics and MRI findings were recorded. All volunteers were invited for a follow-up MRI in 2016; of these, 49 volunteers (53.8%) participated in the follow-up. We enquired whether they had LBP history during the 10 years between the baseline and follow-up examinations. Sagittal T1 and T2-weighted MRI were used to assess the intervertebral space from T12/L1 to L5/S1. We evaluated the presence of disc degeneration by Pfirrmann’s grading system, disc bulging, high intensity zone (HIZ), spondylolisthesis, and any type of Modic changes in the follow-up MRIs. We compared the follow-up MRI findings with the baseline findings; the progress of each finding over the 10 years were also compared between the groups with (n = 36) and without (n = 13) LBP.</p><p>Results</p><p>Average age of the study participants at follow-up was 44.8 years; 25 were female and 24 were male. Average age, sex, body mass index, and smoking habits of those who did and did not participate in the follow-up study, as well as the demographic characteristics of those who did and did not have LBP history during the 10 years, were not significantly different. Compared with the group without LBP history, the group that had LBP history during the 10 years did not have a significantly increased prevalence of disc degeneration, disc bulging, and HIZ in the follow-up and baseline MRIs. Spondylolisthesis and any type of Modic changes were also not associated with LBP history during the 10 years.</p><p>Conclusions</p><p>Follow-up MRI findings consistent with Pfirrmann grading ≥4, disc bulging, HIZ, spondylolisthesis, and any type of Modic changes were not associated with LBP history during the 10 years between the baseline and follow-up study. The progresses of these findings were also not associated with the LBP history. In addition, baseline MRI findings were not associated with LBP history during the 10 years; therefore, our data suggest that baseline MRI findings cannot predict future LBP.</p></div

Participant characteristics: psychometric testing of the STarT-J (n = 2000).

<p>Participant characteristics: psychometric testing of the STarT-J (n = 2000).</p

Score distribution of STarT-J items and risk group distribution (n = 2000).

<p>Score distribution of STarT-J items and risk group distribution (n = 2000).</p

Distribution of the displacement distance.

(A, B) Histograms showing the displacement distance distributions in the BFN group (A) and the PFNA group (B). Histograms are used in descriptive epidemiological studies. There was a significant difference in the displacement distance distribution between the two groups (p<0.001).</p

Mean number of absences for the three STarT-J risk groups.

<p>The linear trend was tested using the Jonckheere-Terpstra test (p < 0.0001). STarT-J: The Japanese version of the STarT Back Tool.</p

STarT Back Tool.

<p>Response options for items 1–8 are “disagree” (0 points) or “agree” (1 point). Responses to item 9 are on a scale of 1–5: “not at all,” “slightly,” “moderately,” “very much,” or “extremely.” The first three options (“not at all,” “slightly,” and “moderately”) are scored as 0, and the remaining two options (“very much” and “extremely”) are scored as 1. Items 1–4 constitute the physical subscale. Items 5–9 constitute the psychosocial subscale.</p

Reduction status and screw direction in the BFN and PFNA groups.

Reduction status and screw direction in the BFN and PFNA groups.</p

STarT Back Tool.

<p>Response options for items 1–8 are “disagree” (0 points) or “agree” (1 point). Responses to item 9 are on a scale of 1–5: “not at all,” “slightly,” “moderately,” “very much,” or “extremely.” The first three options (“not at all,” “slightly,” and “moderately”) are scored as 0, and the remaining two options (“very much” and “extremely”) are scored as 1. Items 1–4 constitute the physical subscale. Items 5–9 constitute the psychosocial subscale.</p

Spearman’s correlation coefficients for the STarT-J and related measures.

<p>Spearman’s correlation coefficients for the STarT-J and related measures.</p