The efficacy of anal fistula plug in fistula-in-ano: a systematic review

AIMS

To assess the efficacy of anal fistula plug (AFP) procedure for the treatment of fistula-in-ano especially the complex fistulas.

METHOD

The database of PUBMED, MEDLINE, SCOPUS, EMBASE and COCHRANE LIBRARY for the period 1995-2009 was searched. A systematic analysis was carried to evaluate the success rate of AFP procedure in fistula-in-ano.

RESULTS

A total of 25 studies were extracted and 12 (n = 317) were finally included in the systematic review. The follow-up period ranged from 3.5 to 12 months. The AFP procedure had a success rate (patient cure rate) ranging from 24% to 92%. In complex fistula-in-ano in prospective studies (8/12 studies), the success rate was 35-87%. The success rate in patients with Crohn's disease was 29-86%. The success rate in the patients with single tracts was 44-93% and in patients with multiple tracts, success ranged from 20% to 71%. The abscess formation/sepsis rate was 4-29% (11/108) and the plug extrusion rate was 4-41% (42/232-19%).

CONCLUSION

Anal fistula plug procedure has a success rate ranging from 24% to 92% in different studies. In prospective studies of complex fistula-in-ano, there was a moderate success rate of 35-87%. As AFP is associated with low morbidity and sepsis, it appears to be a safe procedure. Further randomized controlled trials studying objective parameters of fistula healing are needed to substantiate these findings.

Hdm2 negatively regulates telomerase activity by functioning as an E3 ligase of hTERT

In this study, we identified posttranslational regulation of human telomerase reverse-transcriptase (hTERT) by the E3 ligase Hdm2. The telomerase activity generated by exogenous hTERT in U2OS cells was reduced on adriamycin treatment. The overexpressed levels of hTERT were also decreased under the same conditions. These processes were reversed by treatment with a proteasome inhibitor or depletion of Hdm2. Furthermore, intrinsic telomerase activity was increased in HCT116 cells with ablation of Hdm2. Immunoprecipitation analyses showed that hTERT and Hdm2 bound to each other in multiple domains. Ubiquitination analyses showed that Hdm2 could polyubiquitinate hTERT principally at the N-terminus, which was further degraded in a proteasome-dependent manner. An hTERT mutant with all five lysine residues at the N-terminus of hTERT that mutated to arginine became resistant to Hdm2-mediated ubiquitination and degradation. In U2OS cells, depletion of Hdm2 or addition of the Hdm2-resistant hTERT mutant strengthened the cellular protective effects against apoptosis. Similar results were obtained with the Hdm2-stable H1299 cell line. These observations indicate that Hdm2 is an E3 ligase of hTERT.

Exposure of fish to high-intensity sonar does not induce acute pathology

This study investigated immediate effects of intense sound exposure associated with low-frequency (170-320 Hz) or with mid-frequency (2.8-3.8 kHz) sonars on caged rainbow trout Oncorhynchus mykiss, channel catfish Ictalurus punctatus and hybrid sunfish Lepomis sp. in Seneca Lake, New York, U.S.A. This study focused on potential effects on inner ear tissues using scanning electron microscopy and on non-auditory tissues using gross and histopathology. Fishes were exposed to low-frequency sounds for 324 or 628 s with a received peak signal level of 193 dB re 1 microPa (root mean square, rms) or to mid-frequency sounds for 15 s with a received peak signal level of 210 dB re 1 microPa (rms). Although a variety of clinical observations from various tissues and organ systems were described, no exposure-related pathologies were observed. This study represents the first investigation of the effects of high-intensity sonar on fish tissues in vivo. Data from this study indicate that exposure to low and midfrequency sonars, as described in this report, might not have acute effects on fish tissues.

Detection of citrate synthase autoantibodies in rats with chronic allograft nephropathy

Citrate synthase (CS) is the one of the key enzymes in the citric acid cycle and an important mitochondrial autoantigen. The autoimmune responses against CS have not been studied in chronic allograft nephropathy (CAN). This study investigated the role of specific CS autoantibodies in rats bearing renal allografts affected with CAN.

METHODS

Fisher344 rat renal grafts were orthotopically transplanted into Lewis rats following the procedure of Kamada with our modification. Lewis-to-Lewis and Fisher344-to-Fisher344 kidney transplantations were also performed as autologous control groups (each n = 9). All the allograft recipients given cyclosporine (10 mg/kg(-1)d(-1) x 10 d) were divided into four groups (each n = 9): (1) vehicle: normal saline orally; (2) cyclosporine: 6 mg/kg(-1)d(-1); (3)FK506: 0.15 mg/kg(-1)d(-1); (4) mycophenolate mofetil (MMF): 20 mg/ kg(-1)d(-1). At 4, 8, and 12 weeks posttransplantation, the animals were sacrificed to harvest sera and renal allografts. The serum creatinine (SCr) was measured and pathological changes assessed according to Banff 97 criteria. IgM and IgG isotypes of CS antibodies were detected in all recipient sera by enzyme linked immunosorbent assays.

RESULTS

Both IgM and IgG isotype CS autoantibodies were observed in the sera of all the recipients before and after transplantation, but the levels of IgM CS autoantibody were obviously higher than IgG isotype in all the blood samples. It was stable not only in autologous but also in allograft groups. In both autologous groups, the SCr and IgM and IgG isotype CS autoantibodies showed no obvious change before and after transplantation, and no typical CAN occurred. The values of IgG isotype of CS autoantibody (DeltaOD) at 4, 8 and 12 weeks were stable. At 4 weeks, the values of SCr, Banff score, and IgG isotype CS autoantibody (DeltaOD) were not significantly different (P > .05) among the allograft groups. At 8 and 12 weeks, with progression of CAN in vehicle, cyclosporine and FK506 groups' values of SCr, Banff score, and IgG (DeltaOD) also increased dramatically (P = .005) in all three groups when compared with the baseline and 4 week values, but the differences among the three groups were not significant (P > .05). At 8 and 12 weeks, the MMF group suffered mild-to-moderate CAN, but the values of SCr and Banff score were significantly lower than those in the other three groups. MMF significantly inhibited the formation of IgG (DeltaOD) when compared with the other three groups (P = .02).

CONCLUSION

This study suggested that the IgG isotype of CS autoantibody contributes to CAN after kidney transplantation. The IgM isotype is physiological. MMF significantly inhibited the formation of IgG isotype CS autoantibody, which may be related to its effects to alleviate CAN.

Enhanced electroluminescence from SiN-based multilayer structure by laser crystallization of ultrathin amorphous Si-rich SiN layers

Luminescent SiN-based multilayers were prepared in a plasma enhanced chemical vapor deposition system followed by subsequently laser crystallization of ultrathin amorphous Si-rich SiN sublayers. The cross-sectional TEM analysis reveals that grain size of Si nanocrystals embedded in the Si-rich SiN sublayers is independent of the laser fluence, while the grain density can be well controlled by the laser fluence. The devices containing the laser crystallized multilayers show a low turn-on voltage of 5 V and exhibit strong green light emission under both optical and electrical excitations. Moreover, the device after laser-irradiated at 554 mJ/cm(2) shows a significantly enhanced EL intensity as well as external quantum efficiency compared with the device without laser irradiation. The EL mechanism is suggested from the bipolar recombination of electron-hole pairs at Si nanocrystals. The improved performance of the devices was discussed.

Abnormal motor reflexes and dormant facial motor neurons in rats with facial-facial anastomosis

After facial nerve injury, some post-paralysis sequelae, such as synkinesis, hemispasm and 'crocodile tears' syndrome appear. The psychosocial impact of these sequelae is unavoidable. Despite recent advances and the growing popularity of this field, the pathophysiological mechanisms of facial nerve injury and regeneration are still not well understood. In this report, an abnormal motor reflex coincident with synkinetic facial movement was examined in a rat model using the blink reflex technique. Some dormant facial motor neurons were found which could not innervate through the suture site but remained alive. These results suggest that such dormant neurons might exert roles distinct from those of re-innervated neurons during facial nerve injury and regeneration. Further study is required to elucidate the biomolecular structure and electrophysiological features of such neurons.