Medium-term Outcomes of Excision Using Surgical Microscope of Tenosynovial Giant Cell Tumors of the Hand.

BACKGROUND/AIM: The recurrence rate following the excision of tenosynovial giant cell tumors (TSGCT) of the hand is very high. Intraoperative application of a surgical microscope has been reported. However, to date, there are no reports of medium-term outcomes related to this technique. This study aimed to evaluate the medium-term outcomes of tumor excision using surgical microscope for TSGCT of the hand. PATIENTS AND METHODS: A total of 27 patients, who underwent an initial surgery for histologically-confirmed TSGCT of the hand, between 2008 and 2020, were included and evaluated. The mean follow-up time postoperatively was 6.8 years. Tumor recurrence and preoperative tumor characteristics were assessed. RESULTS: All tumors were adherent to tendons, tendon sheaths, neurovascular structures or periarticular ligaments and capsules. Bony lesions were observed in 11 tumors. The surgical microscope was used in 13 tumors. Recurrences were observed in three tumors (overall recurrence rate: 11%). Tumor characteristics were similar in both groups, but the recurrence rate in the group treated using the surgical microscope was 0%, whereas the recurrence rate in the group treated without the surgical microscope was 21%. Re-operations using the surgical microscope for recurrent tumors were performed, without recurrence postoperatively. CONCLUSION: Among patients with TSGCT of the hand treated with tumor excision using the surgical microscope, the postoperative recurrence rate was 0%. Based on the results of this study, the surgical microscope might be used for excision of TSGCTs of the hand.

Different Activity Patterns in Retinal Ganglion Cells of TRPM1 and mGluR6 Knockout Mice.

TRPM1, the first member of the melanoma-related transient receptor potential (TRPM) subfamily, is the visual transduction channel downstream of metabotropic glutamate receptor 6 (mGluR6) on retinal ON bipolar cells (BCs). Human TRPM1 mutations are associated with congenital stationary night blindness (CSNB). In both TRPM1 and mGluR6 KO mouse retinas, OFF but not ON BCs respond to light stimulation. Here we report an unexpected difference between TRPM1 knockout (KO) and mGluR6 KO mouse retinas. We used a multielectrode array (MEA) to record spiking in retinal ganglion cells (RGCs). We found spontaneous oscillations in TRPM1 KO retinas, but not in mGluR6 KO retinas. We performed a structural analysis on the synaptic terminals of rod ON BCs. Intriguingly, rod ON BC terminals were significantly smaller in TRPM1 KO retinas than in mGluR6 KO retinas. These data suggest that a deficiency of TRPM1, but not of mGluR6, in rod ON bipolar cells may affect synaptic terminal maturation. We speculate that impaired signaling between rod BCs and AII amacrine cells (ACs) leads to spontaneous oscillations. TRPM1 and mGluR6 are both essential components in the signaling pathway from photoreceptors to ON BC dendrites, yet they differ in their effects on the BC terminal and postsynaptic circuitry.

ß-Sitosteryl (6'-O-linoleoyl)-glucoside of soybean (Glycine max L.) crude extract inhibits Y-family DNA polymerases.

In the screening of selective DNA polymerase (pol) inhibitors, we isolated an acylated steryl glycoside, ß-sitosteryl (6'-O-linoleoyl)-glucoside (compound 1), from the waste extract of soybean (Glycine max L.) oil. This compound exhibited a marked ability to inhibit the activities of eukaryotic Y-family pols (pols η, ι and κ), which are repair-related pols. Among mammalian Y-family pols, the activity of mouse pol κ was most strongly inhibited by compound 1, with an IC(50) value of 10.2 µM. On the other hand, compound 1 had no effect on the activities of other eukaryotic pols such as A-family (pol γ), B-family (pols α, δ, and ε), or X-family (pols ß, λ and terminal deoxynucleotidyl transferase) pols. In addition, compound 1 had no effect on prokaryotic pols or other DNA metabolic enzymes such as calf primase of pol α, T7 RNA polymerase, T4 polynucleotide kinase, or bovine deoxyribonuclease I. Compound 1 consists of 3 groups: ß-sitosteryl (compound 2), linoleic acid (compound 3), and D-glucose (compound 4). Compound 3 inhibited the activities of all mammalian pols tested, but compounds 2 and 4 did not have any effect on the tested pols. Kinetic studies showed that the inhibition of pol κ activity by compound 1 was noncompetitive with both the DNA template-primer and nucleotide substrate, whereas compound 3-induced inhibition was competitive with the DNA template-primer and noncompetitive with the nucleotide substrate. The relationship between the structure of compound 1 and the selective inhibition of eukaryotic Y-family pols is discussed.