Interventional treatments for prolapsing haemorrhoids: network meta-analysis

Background

Multiple treatments for early–moderate grade symptomatic haemorrhoids currently exist, each associated with their respective efficacy, complications, and risks. The aim of this study was to compare the relative clinical outcomes and effectiveness of interventional treatments for grade II–III haemorrhoids.

Methods

A systematic review was conducted according to PRISMA criteria for all the RCTs published between 1980 and 2020; manuscripts were identified using the MEDLINE, Embase, and CENTRAL databases. Inclusion criteria were RCTs comparing procedural interventions for grade II–III haemorrhoids. Primary outcomes of interest were: symptom recurrence at a minimum follow-up of 6 weeks, postprocedural pain measured on a visual analogue scale (VAS) on day 1, and postprocedural complications (bleeding, urinary retention, and bowel incontinence). After bias assessment and heterogeneity analysis, a Bayesian network meta-analysis was performed.

Results

Seventy-nine RCTs were identified, including 9232 patients. Fourteen different treatments were analysed in the network meta-analysis. Overall, there were 59 RCTs (73 per cent) judged as being at high risk of bias, and the greatest risk was in the domain measurement of outcome. Variable amounts of heterogeneity were detected in direct treatment comparisons, in particular for symptom recurrence and postprocedural pain. Recurrence of haemorrhoidal symptoms was reported by 54 studies, involving 7026 patients and 14 treatments. Closed haemorrhoidectomy had the lowest recurrence risk, followed by open haemorrhoidectomy, suture ligation with mucopexy, stapled haemorrhoidopexy, and Doppler-guided haemorrhoid artery ligation (DG-HAL) with mucopexy. Pain was reported in 34 studies involving 3812 patients and 11 treatments. Direct current electrotherapy, DG-HAL with mucopexy, and infrared coagulation yielded the lowest pain scores. Postprocedural bleeding was recorded in 46 studies involving 5696 patients and 14 treatments. Open haemorrhoidectomy had the greatest risk of postprocedural bleeding, followed by stapled haemorrhoidopexy and closed haemorrhoidectomy. Urinary retention was reported in 30 studies comparing 10 treatments involving 3116 participants. Open haemorrhoidectomy and stapled haemorrhoidopexy had significantly higher odds of urinary retention than rubber band ligation and DG-HAL with mucopexy. Nine studies reported bowel incontinence comparing five treatments involving 1269 participants. Open haemorrhoidectomy and stapled haemorrhoidopexy had the highest probability of bowel incontinence.

Conclusion

Open and closed haemorrhoidectomy, and stapled haemorrhoidopexy were associated with worse pain, and more postprocedural bleeding, urinary retention, and bowel incontinence, but had the lowest rates of symptom recurrence. The risks and benefits of each treatment should be discussed with patients before a decision is made.

Expression of erythropoietin and its receptor in kidneys from normal and cyclosporine-treated rats

Long-term treatment with cyclosporine A (CsA) is associated with various types of complications; however, CsA-induced anemia has not been reported. The present study examined the impact of CsA on hematopoietic parameters and intrarenal expression of erythropoietin (EPO) and the EPO receptor (EPOR) in a rat model of chronic CsA nephrotoxicity. Sprague-Dawley rats were fed a low-salt diet (0.05% sodium) and were treated daily for 4 weeks with vehicle (olive oil 1 mL/kg subcutaneously) or CsA (15 mg/kg subcutaneously). The expression of EPO and EPOR was evaluated by immunohistochemistry and immunoblotting, and hematopoietic parameters were assessed by measuring blood hemoglobin and hematocrit levels, and these variables were compared between treatment groups. Renal function, oxidative stress, histopathology (tubulointerstitial fibrosis), apoptotic cell death, and expression of transforming growth factor β-inducible gene-h3 (βig-h3) were also compared between treatment groups. In kidneys from vehicle-treated rats, endogenous EPO and EPOR protein were expressed constitutively in the outer stripe of the outer medulla and the cortex. EPO protein expression decreased significantly in kidneys from CsA-treated rats. By contrast, EPOR expression was higher in kidneys from CsA-treated rats than in vehicle-treated rats. These changes were accompanied by decreases in serum hemoglobin and hematocrit levels and correlated with the number of cells positive for terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (r = -0.769, P = .003) and βig-h3 protein expression (r = -0.910, P < .001). Long-term treatment with CsA suppresses renal endogenous EPO expression, resulting in anemia. Increases in apoptotic cell death and βig-h3 expression are closely associated with inhibition of EPO expression in chronic CsA nephrotoxicity.

Human estrogenic 17beta-hydroxysteroid dehydrogenase: predominance of estrone reduction and its induction by NADPH

Human estrogenic 17beta-hydroxysteroid dehydrogenase (17beta-HSD1) plays a crucial role in the last step of the synthesis of estrogens. A detailed kinetic study demonstrated that the enzyme shows about 240 fold higher specificity towards estrone reduction than estradiol oxidation at physiological pH using tri-phosphate cofactors. The kcat/Km values are 96 +/- 10 and 0.4 +/- 0.1 s-1 (microM)-1 respectively for the above two reactions. However, it has been shown that this difference is closely linked to the use of NADPH and NADP cofactors. A binding study using equilibrium dialysis indicated similar KD (equilibrium dissociation constant) of 11 +/- 1 and 4.7 +/- 0.9 microM for estrone and estradiol, respectively. The binding affinity of 17beta-HSD1 to estrone was significantly increased with a KD of 1.6 +/- 0.2 microM in the presence of NADP, the latter used as an analogue of the NADPH. The results of binding studies agree with the steady-state kinetics, which showed that the Km of estrone is 12-fold lower when using NADPH as a cofactor than when using NADH. These results strongly suggest that the cofactor plays a crucial role in the stimulation of the specificity for estrogen reduction.

Human 17 beta-hydroxysteroid dehydrogenase: optical properties of its complex with NADP+

The apoenzyme of the human placental 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) and its complex with NADP+ were prepared from two alternative procedures. The apoenzyme (Form I) has an absorption maximum at about 279 nm, and an absorption ratio at 280 and 260 nm of 1.65 +/- 0.1; whereas the complex (Form II) has a broad absorption peak between 268-278 nm, and a 280 to 260 nm ratio of 1.1 +/- 0.05. Upon addition of the substrate estradiol to the complex, an absorption increase at 340 nm and a fluorescence emission at 450 nm, following NADPH formation, were produced. Both changes indicate that one cofactor is tightly bound to the 17 beta-HSD molecule in this complex. No significant optical change can be produced in this way for the apoenzyme. Convenient analyses of cofactor content of the enzyme are thus provided. The optical analyses and the homogeneous apo- or holo-enzyme preparations are important in the study of the enzyme's function and crystallization. This is the first human steroid converting enzyme which has yielded X-ray quality crystals.

Human 17 beta-hydroxysteroid dehydrogenase: overproduction using a baculovirus expression system and characterization

Estrogenic 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) plays a pivotal role in the synthesis of estrogens. We overproduced human placental estrogenic 17 beta-HSD using a baculovirus expression system for the study of the enzyme mechanism. A cDNA encoding the entire open reading frame of human 17 beta-HSD was inserted into the genome of Autographa californica nuclear polyhedrosis virus and expressed in Spodoptera frugiperda (Sf9) insect cells. Metabolic labeling and Western blot analysis using polyclonal antibodies raised against native human 17 beta-HSD indicated that a molecule with an apparent mass of 35 kDa was maximally expressed 60 h after infection. At that time interval, intracellular 17 beta-HSD activity reached 0.26 U/mg of protein in crude homogenate, about 70 times the level measured in human placenta. Purification of recombinant 17 beta-HSD was achieved by a single affinity fast liquid protein chromatography step yielding 24 mg of purified 17 beta-HSD protein per liter of suspension culture, with a specific activity of about 8 mumol/min/mg of protein for conversion of estradiol into estrone, at pH 9.2. In addition, the recombinant protein purified from infected Sf9 cells was assembled as a dimer with molecular mass and specific activity identical to those of the enzyme purified directly from placenta. The present data show that the baculovirus expression system can provide active 17 beta-HSD that is functionally identical to its natural counter-part and easy to purify in quantities suitable for its physico-chemical studies.

Preparation of the apoenzyme and holoenzyme forms of human 17 beta-hydroxysteroid dehydrogenase

The apoenzyme and holoenzyme (NADP+ complex) of human placental 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) were prepared from affinity chromatography using various elutions by column liquid chromatography. The apoenzyme was obtained using NAD+ elution in a Blue-Sepharose column, followed by NAD+ separation on a Phenyl-Superose hydrophobic-interaction or a Mono Q anion-exchange column. The 17 beta-HSD-NADP+ complex was prepared using NADP+ elution in a Blue-Sepharose column. The two forms have different A280/A260 ratios and are suitable for further study of enzyme-cofactor interactions.

Subunit identity of the dimeric 17 beta-hydroxysteroid dehydrogenase from human placenta

Human placental 17 beta-hydroxysteroid dehydrogenase has been purified with a new rapid procedure based on fast protein liquid chromatography, yielding quantitatively a homogeneous preparation with high specific activity catalyzing the oxidation of 7.2 mumol of estradiol/min/mg of enzyme protein at 23 degrees C, pH 9.2. This preparation was shown to have a subunit mass of 34.5 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis while having a molecular mass of 68 kDa by both Superose-12 gel-filtration and native pore gradient gel electrophoresis. When 17 beta-hydroxysteroid dehydrogenase was expressed in HeLa cells or overproduced in insect cells using the baculovirus expression system, both from its cDNA encoding a protein of 34 kDa, the enzyme had the same migration in native and sodium dodecyl sulfate-gel electrophoresis as the purified one from human placenta and eluted from the Superose-12 column at the same elution volume. Moreover, all the above forms of this enzyme have similar specific activity. These results clearly demonstrate the identity of the three enzyme forms. The enzyme produced from the cDNA is expressed as a dimer, and its two subunits are identical. 17 beta-Hydroxysteroid dehydrogenase subunit identity is thus proved. The NH2-terminal analysis revealed a unique sequence of Ala-Arg-Thr-Val-Val-Leu-Ile for the purified enzyme from placenta, further confirming the above conclusion.