Progesterone and Its Metabolites Play a Beneficial Role in Affect Regulation in the Female Brain

Premenstrual dysphoric disorder is a female affective disorder that is defined by mood symptoms. The condition is linked to unstable progesterone concentrations. Progestin supplementation is given in cases of threatened or recurrent miscarriage and for luteal phase support. Progesterone is essential for implantation, immune tolerance, and modulation of uterine contractility. For a long time, the administration of progestins was associated with an unfavorable impact on mood, leading to negative affect, and, therefore, was contraindicated in existing mood disorders. Establishing the role of the natural progesterone derivative allopregnanolone in advances in the treatment of postpartum depression has shed new light on the general pathophysiology of mood disorders. Allopregnanolone directly interacts with gamma-aminobutyric acid type A (GABA-A) receptors even at nanomolar concentrations and induces significant anti-depressant, anti-stress, sedative, and anxiolytic effects. Postpartum depression is caused by a rapid drop in hormones and can be instantly reversed by the administration of allopregnanolone. Premenstrual dysphoric disorder can also be considered to result from insufficient neuroactive steroid action due to low progesterone derivative concentration, unstable hormone levels, or decreased receptor sensitivity. The decrease in progesterone levels in perimenopause is also associated with affective symptoms and an exacerbation of some psychosomatic syndromes. Bioidentical progesterone supplementation encounters several obstacles, including limited absorption, first-pass effect, and rapid metabolism. Hence, non-bioidentical progestins with better bioavailability were widely applied. The paradoxical, unfavorable effect of progestins on mood can be explained by the fact that progestins suppress ovulation and disturb the endocrine function of the ovary in the luteal phase. Moreover, their distinct chemical structure prevents their metabolism to neuroactive, mood-improving derivatives. A new understanding of progesterone-related mood disorders can translate the study results from case series and observational studies to cohort studies, clinical trials, and novel, effective treatment protocols being developed.

New Kid on the Block: The Efficacy of Phytomedicine Extracts Urox® in Reducing Overactive Bladder Symptoms in Rats

The aim of the current study was to determine if phytomedicine (Urox^®) would reverse retinyl acetate (RA)–induced changes characteristic of bladder overactivity. There were 60 rats divided into the following 4 groups: I—control, II—received RA to induce detrusor overactivity (DO), III—received Urox (840 mg daily for 14 days), and IV—received combination of RA and Urox^®. The cystometry was performed 2 days after the last dose of Urox^®. Next, urothelium thickness and biochemical parameter measurements were performed. In group IV, a decrease in basal pressure and detrusor overactivity index was noted when compared to group II. Furthermore, in group IV the following parameters were increased: threshold pressure, voided volume, intercontraction interval, and bladder compliance in comparison with group II. There were significant elevations in c-Fos expression in the neuronal voiding centers in group II, while the expression of c-Fos in group IV was normalized. No significant changes in the values of the analyzed biomarkers in group III were found, while in group II, an elevation in BDNF, NGF, CGRP, ATP, Rho kinase, malondialdehyde, 3-nitrotyrosine, TRPV1, OCT-3, and VAChT and then a decrease in E-cadherin and Z01 were found. A successful restoration of all the abovementioned biomarkers’ levels was observed in group IV. Phytomedicine extracts (Urox^®) were found to be potent in reversing RA-induced changes in several cystometric and biochemical parameters that are determinants of overactive bladder (OAB). The actions of Urox^® were proved to be dependent on several factors, such as growth factors and several OAB biomarkers but not pro-inflammatory cytokines.

Urogynecology Section of the Polish Society of Gynecologists and Obstetricians Guidelines on the management of recurrent pelvic organ prolapse

OBJECTIVES

The aim of the publication was to present the Guideline of the Urogynecology Section of the Polish Society of Gynecologists and Obstetricians (PSGO) for the management of recurrent pelvic organ prolapse, based on the available literature, expert knowledge and opinion, as well as everyday practice.

MATERIAL AND METHODS

In 2005, 2006 and 2010, the panel of PSGO experts published guidelines for the diagnosis and treatment of patients with lower urinary tract symptoms (LUTS). This publication presents an update of those recommendations and concerns recurrent POP treatment.

MAIN CONCLUSION

The analysis of data revealed that sacrocolpopexy with the use of commercial sets or polypropylene hernia mesh is the method of choice for the surgical repair of recurrent vaginal vault prolapse. However, a significantly higher risk of surgical and postoperative complications after sacrocolpopexy, as compared to vaginal surgeries, should be considered when making treatment decisions. In other types of recurrent POP, the choice of surgery method should be tailored to the individual needs of each patient and may depend on the medical center.

Psychiatric History and Overactive Bladder Symptom Severity in Ambulatory Urogynecological Patients

Introduction and hypothesis: A link between psychiatric comorbidities and overactive bladder symptomatology has been suggested by preclinical and clinical studies. Given this, we hypothesized that a psychiatric history and current treatment with psychotropic medications could be related to the severity of overactive bladder and incontinence symptoms in patients referred to a tertiary care urogynecological center. Methods: One hundred and twenty-seven female patients diagnosed with an overactive bladder were screened for a lifetime history of psychiatric disorders and the type and number of psychotropic medications currently taken. The overall severity of overactive bladder symptoms was assessed using the Indevus Urgency Severity Scale. The severity and impact of urinary incontinence on the quality of life were quantified with the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form. Urinary incontinence was further quantified with the aid of the Urinary Distress Inventory-6. The patients were screened for stress urinary incontinence using the Stamey Incontinence Score. Results: A psychiatric history, as well as current use of at least two psychotropic medications, was associated with increased severity of overactive bladder symptoms. A history of depression and current treatment with any selective serotonin reuptake inhibitor was associated with increased severity of stress urinary incontinence symptoms. Current treatment with other psychotropic medications, including sedative-hypnotics and drugs with anticholinergic properties was not related to the severity of overactive bladder and incontinence symptoms.

The Potential of Asiatic Acid in the Reversion of Cyclophosphamide-Induced Hemorrhagic Cystitis in Rats

The purpose of this study was to determine if asiatic acid may act efficiently in the model of cyclophosphamide (CYP)-induced cystitis in rats. We performed experiments after administration of CYP (single dose 200 mg/kg, intraperitoneally), asiatic acid (30 mg/kg/day for 14 consecutive days, by oral gavage), or CYP plus asiatic acid, during which conscious cystometry, measurements of urothelium thickness and bladder edema, as well as selected biomarkers analyses were conducted. In rats that received asiatic acid together with CYP, a drop in bladder basal pressure, detrusor overactivity index, non-voiding contraction amplitude, non-voiding contraction frequency, and the area under the pressure curve were observed, when compared to the CYP group. Furthermore, a significant increase in threshold pressure, voided volume, intercontraction interval, bladder compliance, and volume threshold to elicit NVC were found in that group accordingly. Administration of the asiatic acid successfully restored concentrations of biomarkers both in bladder urothelium (BDNF, CGRP, OCT-3, IL-1β, IL-6, NGF, nitrotyrosine, malondialdehyde, TNF-α, SV2A, SNAP23, SNAP25, PAC-1, ORM1, occludin, IGFBP-3, HB-EGF, T–H protein, Z01, and HPX) and detrusor muscle (Rho kinase and VAChT) in CYP-treated rats. Finally, asiatic acid significantly decreased urothelium thickness and bladder oedema. Asiatic acid proved to be a potent and effective drug in the rat model of CYP-induced cystitis.

Bacterial Colonization as a Possible Source of Overactive Bladder Symptoms in Pediatric Patients: A Literature Review

Overactive Bladder (OAB) is a common condition that is known to have a significant impact on daily activities and quality of life. The pathophysiology of OAB is not completely understood. One of the new hypothetical causative factors of OAB is dysbiosis of an individual urinary microbiome. The major aim of the present review was to identify data supporting the role of bacterial colonization in overactive bladder symptoms in children and adolescents. The second aim of our study was to identify the major gaps in current knowledge and possible areas for future clinical research. There is a growing body of evidence indicating some relationship between qualitative and quantitative characteristics of individual urinary microbiome and OAB symptoms in adult patients. There are no papers directly addressing this issue in children or adolescents. After a detailed analysis of papers relating urinary microbiome to OAB, the authors propose a set of future preclinical and clinical studies which could help to validate the concept in the pediatric population.

The Urogynecology Section of the Polish Society of Gynecologists and Obstetricians Guideline on the use of urodynamic testing in gynecological practice

OBJECTIVES

The aim was to present an interdisciplinary Guideline of the Urogynecology Section of the Polish Society of Gynecologists and Obstetricians (PSGO) for the use of urodynamics (UDS) in the diagnostic process of patients with lower urinary tract symptoms (LUTS) based on the available literature, expert knowledge, and everyday practice.

MATERIAL AND METHODS

A review of the literature concerning the use of UDS in women, including current international guidelines and earlier recommendations of the PSGO Urogynecology Section, was conducted.

RESULTS

Urodynamic testing allows to make the urodynamic diagnosis which, nevertheless, remains to be the preliminary diagnosis. Medical history, physical examination, and detailed analysis of the previous test results (laboratory, imaging, endoscopic) need to be taken into consideration before making the final diagnosis. Urodynamic testing before surgical treatment of SUI is allowable, but the decision remains at the discretion of the physician. Urodynamic testing is not necessary before primary surgical treatment of uncomplicated SUI, but it has been demonstrated to optimize the therapeutic methods in complicated SUI. The significance of UDS in the diagnostic process of patients with overactive bladder symptoms, voiding dysfunction, and bladder outlet obstruction was discussed.

CONCLUSIONS

Urodynamic testing is a vital element of the urogynecological diagnostic process. The scope of UDS should reflect the individual needs and symptoms of each patient and be based on the current guidelines, expert knowledge and experience of the physician, indications, and eligibility, as well as additional test results of the affected patients. Due to formal and legal requirements, PSGO, in this Guideline, wishes to emphasize the need for an individualized approach to both, test performance and result interpretation.

Risk Factors for Surgical Treatment of Endometrial Cancer Using Traditional and Laparoscopic Methods

Surgical treatment is the most important part of therapy for endometrial cancer. The aim of the study was to define factors having the most significant impact on surgical treatment of endometrial cancer when using traditional and laparoscopic methods. In the study, we evaluated 75 females who were treated for endometrial cancer via laparoscopic surgery in 2019 and used a historical control of 70 patients treated by laparotomy in 2011. The evaluated risk factors included the method of surgery, type of lymphadenectomy, patient's age, various obesity parameters, histological grading, cancer clinical staging, pelvic dimensions, previous abdominal surgeries, comorbidities, and number of deliveries. The duration of hospitalization, operation time, loss of hemoglobin, and procedure-related complications were used as parameters of perioperative outcomes. Multivariable linear regression analysis confirmed the following factors as being predictors of worse perioperative outcomes: laparotomy, abdominal obesity (waist circumstance and waist-to-hip ratio), range of lymphadenectomy, prior abdominal surgeries, and larger pelvic dimensions. Abdominal obesity is a significant risk factor in the treatment of endometrial cancer. Laparotomy continues to be utilized frequently in the management of endometrial cancer in Poland as well as elsewhere, and adopting a minimally invasive approach is likely to be beneficial for patient outcome.

Anti-Müllerian hormone level is associated with vitamin D receptor polymorphisms in women with polycystic ovary syndrome

Objective

Our study aimed to investigate the relationship between polymorphisms (Apa1, Bsm1, Fok1, and Cdx2) in the VDR gene as well as AMH and AMHR2 genes and their influence on AMH and 25(OH)D levels in PCOS women.

Study design

Seventy-five patients with PCOS and 23 control women were included. Serum AMH and 25(OH)D levels in patients and controls were measured by enzyme-linked immunosorbent assay (ELISA). Polymorphisms in VDR gene Fok1 C/T (rs2228587), Bsm1 A/G (rs1544410), Apa1 A/C (rs7975232), and Cdx2 A/G (rs11568820) polymorphisms as well as AMH G/T (rs10407022) and AMHR2 A/G (rs2002555) were analyzed using real-time PCR.

Results

Analysis of the VDR Cdx2 polymorphism showed a significantly higher frequency of the homozygous GG (mutant) genotype in the PCOS group as compared with the control group (p < 0.05). The analysis revealed a statistically significant correlation between the presence of FokI and ApaI polymorphisms and AMH levels in PCOS women (p < 0.05). The presence of mutant genotypes (CT, TT) in the Fok1 and (CA, CC) in the Apa1 polymorphisms were associated with higher AMH level in PCOS women (p < 0.05). No statistically significant correlations between AMH and AMHR2 polymorphisms and AMH level were found. Moreover, there was no correlation between AMH and 25(OH)D levels in the PCOS or in the control group.

Conclusion

It seems that the elevated AMH level is associated with VDR Fokl and Apal polymorphisms, but not with 25(OH)D levels in PCOS women. Further research is needed to determine the role of VDR polymorphism in AMH level in PCOS.

Comprehensive functional characterization of the glycoside hydrolase family 3 enzymes from Cellvibrio japonicus reveals unique metabolic roles in biomass saccharification

Lignocellulose degradation is central to the carbon cycle and renewable biotechnologies. The xyloglucan (XyG), β(1→3)/β(1→4) mixed-linkage glucan (MLG) and β(1→3) glucan components of lignocellulose represent significant carbohydrate energy sources for saprophytic microorganisms. The bacterium Cellvibrio japonicus has a robust capacity for plant polysaccharide degradation, due to a genome encoding a large contingent of Carbohydrate-Active enZymes (CAZymes), many of whose specific functions remain unknown. Using a comprehensive genetic and biochemical approach, we have delineated the physiological roles of the four C. japonicus glycoside hydrolase family 3 (GH3) members on diverse β-glucans. Despite high protein sequence similarity and partially overlapping activity profiles on disaccharides, these β-glucosidases are not functionally equivalent. Bgl3A has a major role in MLG and sophorose utilization, and supports β(1→3) glucan utilization, while Bgl3B underpins cellulose utilization and supports MLG utilization. Bgl3C drives β(1→3) glucan utilization. Finally, Bgl3D is the crucial β-glucosidase for XyG utilization. This study not only sheds the light on the metabolic machinery of C. japonicus, but also expands the repertoire of characterized CAZymes for future deployment in biotechnological applications. In particular, the precise functional analysis provided here serves as a reference for informed bioinformatics on the genomes of other Cellvibrio and related species.

Corrigendum: Complex pectin metabolism by gut bacteria reveals novel catalytic functions

This corrects the article DOI: 10.1038/nature21725.

Complex pectin metabolism by gut bacteria reveals novel catalytic functions

Carbohydrate polymers drive microbial diversity in the human gut microbiota. It is unclear, however, whether bacterial consortia or single organisms are required to depolymerize highly complex glycans. Here we show that the gut bacterium Bacteroides thetaiotaomicron utilizes the most structurally complex glycan known; the plant pectic polysaccharide rhamnogalacturonan-II, cleaving all but one of its 21 distinct glycosidic linkages. We show that rhamnogalacturonan-II side-chain and backbone deconstruction are coordinated, to overcome steric constraints, and that degradation reveals previously undiscovered enzyme families and novel catalytic activities. The degradome informs revision of the current structural model of RG-II and highlights how individual gut bacteria orchestrate manifold enzymes to metabolize the most challenging glycans in the human diet.

Systems analysis in Cellvibrio japonicus resolves predicted redundancy of β-glucosidases and determines essential physiological functions

Degradation of polysaccharides forms an essential arc in the carbon cycle, provides a percentage of our daily caloric intake, and is a major driver in the renewable chemical industry. Microorganisms proficient at degrading insoluble polysaccharides possess large numbers of carbohydrate active enzymes (CAZymes), many of which have been categorized as functionally redundant. Here we present data that suggests that CAZymes that have overlapping enzymatic activities can have unique, non-overlapping biological functions in the cell. Our comprehensive study to understand cellodextrin utilization in the soil saprophyte Cellvibrio japonicus found that only one of four predicted β-glucosidases is required in a physiological context. Gene deletion analysis indicated that only the cel3B gene product is essential for efficient cellodextrin utilization in C. japonicus and is constitutively expressed at high levels. Interestingly, expression of individual β-glucosidases in Escherichia coli K-12 enabled this non-cellulolytic bacterium to be fully capable of using cellobiose as a sole carbon source. Furthermore, enzyme kinetic studies indicated that the Cel3A enzyme is significantly more active than the Cel3B enzyme on the oligosaccharides but not disaccharides. Our approach for parsing related CAZymes to determine actual physiological roles in the cell can be applied to other polysaccharide-degradation systems.

The Mechanism by Which Arabinoxylanases Can Recognize Highly Decorated Xylans

The enzymatic degradation of plant cell walls is an important biological process of increasing environmental and industrial significance. Xylan, a major component of the plant cell wall, consists of a backbone of β-1,4-xylose (Xylp) units that are often decorated with arabinofuranose (Araf) side chains. A large penta-modular enzyme, CtXyl5A, was shown previously to specifically target arabinoxylans. The mechanism of substrate recognition displayed by the enzyme, however, remains unclear. Here we report the crystal structure of the arabinoxylanase and the enzyme in complex with ligands. The data showed that four of the protein modules adopt a rigid structure, which stabilizes the catalytic domain. The C-terminal non-catalytic carbohydrate binding module could not be observed in the crystal structure, suggesting positional flexibility. The structure of the enzyme in complex with Xylp-β-1,4-Xylp-β-1,4-Xylp-[α-1,3-Araf]-β-1,4-Xylp showed that the Araf decoration linked O₃ to the xylose in the active site is located in the pocket (−2* subsite) that abuts onto the catalytic center. The −2* subsite can also bind to Xylp and Arap, explaining why the enzyme can utilize xylose and arabinose as specificity determinants. Alanine substitution of Glu⁶⁸, Tyr⁹², or Asn¹³⁹, which interact with arabinose and xylose side chains at the −2* subsite, abrogates catalytic activity. Distal to the active site, the xylan backbone makes limited apolar contacts with the enzyme, and the hydroxyls are solvent-exposed. This explains why CtXyl5A is capable of hydrolyzing xylans that are extensively decorated and that are recalcitrant to classic endo-xylanase attack.

Recognition of xyloglucan by the crystalline cellulose-binding site of a family 3a carbohydrate-binding module

Type A non-catalytic carbohydrate-binding modules (CBMs), exemplified by CtCBM3acipA, are widely believed to specifically target crystalline cellulose through entropic forces. Here we have tested the hypothesis that type A CBMs can also bind to xyloglucan (XG), a soluble β-1,4-glucan containing α-1,6-xylose side chains. CtCBM3acipA bound to xyloglucan in cell walls and arrayed on solid surfaces. Xyloglucan and cellulose were shown to bind to the same planar surface on CBM3acipA. A range of type A CBMs from different families were shown to bind to xyloglucan in solution with ligand binding driven by enthalpic changes. The nature of CBM-polysaccharide interactions is discussed.

Human gut Bacteroidetes can utilize yeast mannan through a selfish mechanism

Yeasts, which have been a component of the human diet for at least 7000 years, possess an elaborate cell wall α-mannan. The influence of yeast mannan on the ecology of the human microbiota is unknown. Here we show that yeast α-mannan is a viable food source for Bacteroides thetaiotaomicron (Bt), a dominant member of the microbiota. Detailed biochemical analysis and targeted gene disruption studies support a model whereby limited cleavage of α-mannan on the surface generates large oligosaccharides that are subsequently depolymerized to mannose by the action of periplasmic enzymes. Co-culturing studies showed that metabolism of yeast mannan by Bt presents a ‘selfish’ model for the catabolism of this recalcitrant polysaccharide. This report shows how a cohort of highly successful members of the microbiota has evolved to consume sterically-restricted yeast glycans, an adaptation that may reflect the incorporation of eukaryotic microorganisms into the human diet.

Understanding how the complex molecular architecture of mannan-degrading hydrolases contributes to plant cell wall degradation

Microbial degradation of plant cell walls is a central component of the carbon cycle and is of increasing importance in environmentally significant industries. Plant cell wall-degrading enzymes have a complex molecular architecture consisting of catalytic modules and, frequently, multiple non-catalytic carbohydrate binding modules (CBMs). It is currently unclear whether the specificities of the CBMs or the topology of the catalytic modules are the primary drivers for the specificity of these enzymes against plant cell walls. Here, we have evaluated the relationship between CBM specificity and their capacity to enhance the activity of GH5 and GH26 mannanases and CE2 esterases against intact plant cell walls. The data show that cellulose and mannan binding CBMs have the greatest impact on the removal of mannan from tobacco and Physcomitrella cell walls, respectively. Although the action of the GH5 mannanase was independent of the context of mannan in tobacco cell walls, a significant proportion of the polysaccharide was inaccessible to the GH26 enzyme. The recalcitrant mannan, however, was fully accessible to the GH26 mannanase appended to a cellulose binding CBM. Although CE2 esterases display similar specificities against acetylated substrates in vitro, only CjCE2C was active against acetylated mannan in Physcomitrella. Appending a mannan binding CBM27 to CjCE2C potentiated its activity against Physcomitrella walls, whereas a xylan binding CBM reduced the capacity of esterases to deacetylate xylan in tobacco walls. This work provides insight into the biological significance for the complex array of hydrolytic enzymes expressed by plant cell wall-degrading microorganisms.

Evidence that GH115 α-glucuronidase activity, which is required to degrade plant biomass, is dependent on conformational flexibility

The microbial degradation of the plant cell wall is an important biological process that is highly relevant to environmentally significant industries such as the bioenergy and biorefining sectors. A major component of the wall is glucuronoxylan, a β1,4-linked xylose polysaccharide that is decorated with α-linked glucuronic and/or methylglucuronic acid (GlcA/MeGlcA). Recently three members of a glycoside hydrolase family, GH115, were shown to hydrolyze MeGlcA side chains from the internal regions of xylan, an activity that has not previously been described. Here we show that a dominant member of the human microbiota, Bacteroides ovatus, contains a GH115 enzyme, BoAgu115A, which displays glucuronoxylan α-(4-O-methyl)-glucuronidase activity. The enzyme is significantly more active against substrates in which the xylose decorated with GlcA/MeGlcA is flanked by one or more xylose residues. The crystal structure of BoAgu115A revealed a four-domain protein in which the active site, comprising a pocket that abuts a cleft-like structure, is housed in the second domain that adopts a TIM barrel-fold. The third domain, a five-helical bundle, and the C-terminal β-sandwich domain make inter-chain contacts leading to protein dimerization. Informed by the structure of the enzyme in complex with GlcA in its open ring form, in conjunction with mutagenesis studies, the potential substrate binding and catalytically significant amino acids were identified. Based on the catalytic importance of residues located on a highly flexible loop, the enzyme is required to undergo a substantial conformational change to form a productive Michaelis complex with glucuronoxylan.

Mesh retraction correlates with vaginal pain and overactive bladder symptoms after anterior vaginal mesh repair

INTRODUCTION AND HYPOTHESIS

The aim of the present study was to determine possible correlations between mesh retraction after anterior vaginal mesh repair and de novo stress urinary incontinence (SUI), overactive bladder (OAB), and vaginal pain symptoms.

METHODS

One hundred and three women with symptomatic prolapse of the anterior vaginal wall, stages 3 and 4 based on the Pelvic Organ Prolapse Quantification (POP-Q) system, underwent Prolift anterior™ implantation. At a 6-month follow-up, the patients were interviewed for de novo SUI, OAB, and vaginal pain, and underwent an introital/transvaginal ultrasound examination to measure the mesh length in the midsagittal plane.

RESULTS

Mesh retraction was significantly larger in a subgroup of patients (n = 20; 19.4 %) presenting de novo OAB symptoms on the follow-up assessment compared with those without this complication (5.0 cm vs. 4.3 cm; p < 0.05). Mesh retraction was also significantly larger in a subgroup of patients (n = 23; 22.3 %) reporting postoperative vaginal pain compared with the women who did not report any postoperative vaginal pain (5.3 cm vs. 4.2 cm; p < 0.01). A significant correlation was found between mesh retraction and the severity of vaginal pain (R = 0.4, p < 0.01). Mesh retraction did not differ between patients with de novo SUI symptoms and those without this complication.

CONCLUSIONS

Mesh retraction assessed on ultrasound examination after anterior vaginal mesh repair may correlate with de novo OAB symptoms and vaginal pain.

Understanding how noncatalytic carbohydrate binding modules can display specificity for xyloglucan

Plant biomass is central to the carbon cycle and to environmentally sustainable industries exemplified by the biofuel sector. Plant cell wall degrading enzymes generally contain noncatalytic carbohydrate binding modules (CBMs) that fulfil a targeting function, which enhances catalysis. CBMs that bind β-glucan chains often display broad specificity recognizing β1,4-glucans (cellulose), β1,3-β1,4-mixed linked glucans and xyloglucan, a β1,4-glucan decorated with α1,6-xylose residues, by targeting structures common to the three polysaccharides. Thus, CBMs that recognize xyloglucan target the β1,4-glucan backbone and only accommodate the xylose decorations. Here we show that two closely related CBMs, CBM65A and CBM65B, derived from EcCel5A, a Eubacterium cellulosolvens endoglucanase, bind to a range of β-glucans but, uniquely, display significant preference for xyloglucan. The structures of the two CBMs reveal a β-sandwich fold. The ligand binding site comprises the β-sheet that forms the concave surface of the proteins. Binding to the backbone chains of β-glucans is mediated primarily by five aromatic residues that also make hydrophobic interactions with the xylose side chains of xyloglucan, conferring the distinctive specificity of the CBMs for the decorated polysaccharide. Significantly, and in contrast to other CBMs that recognize β-glucans, CBM65A utilizes different polar residues to bind cellulose and mixed linked glucans. Thus, Gln¹⁰⁶ is central to cellulose recognition, but is not required for binding to mixed linked glucans. This report reveals the mechanism by which β-glucan-specific CBMs can distinguish between linear and mixed linked glucans, and show how these CBMs can exploit an extensive hydrophobic platform to target the side chains of decorated β-glucans.

Targeting both Notch and ErbB-2 signalling pathways is required for prevention of ErbB-2-positive breast tumour recurrence

BACKGROUND

We reported that Notch-1, a potent breast oncogene, is activated in response to trastuzumab and contributes to trastuzumab resistance in vitro. We sought to determine the preclinical benefit of combining a Notch inhibitor (γ-secretase inhibitor (GSI)) and trastuzumab in both trastuzumab-sensitive and trastuzumab-resistant, ErbB-2-positive, BT474 breast tumours in vivo. We also studied if the combination therapy of lapatinib plus GSI can induce tumour regression of ErbB-2-positive breast cancer.

METHODS

We generated orthotopic breast tumour xenografts from trastuzumab- or lapatinib-sensitive and trastuzumab-resistant BT474 cells. We investigated the antitumour activities of two distinct GSIs, LY 411 575 and MRK-003, in vivo.

RESULTS

Our findings showed that combining trastuzumab plus a GSI completely prevented (MRK-003 GSI) or significantly reduced (LY 411 575 GSI) breast tumour recurrence post-trastuzumab treatment in sensitive tumours. Moreover, combining lapatinib plus MRK-003 GSI showed significant reduction of tumour growth. Furthermore, a GSI partially reversed trastuzumab resistance in resistant tumours.

CONCLUSION

Our data suggest that a combined inhibition of Notch and ErbB-2 signalling pathways could decrease recurrence rates for ErbB-2-positive breast tumours and may be beneficial in the treatment of recurrent trastuzumab-resistant disease.

[Risk factors of pelvic organ prolapsed in women qualified to reconstructive surgery--the Polish multicenter study]

AIM OF STUDY

To evaluate the prevalence rate of various pelvic floor disorders among patients treated in 8 academic centers in Poland due to pelvic organ prolapse (POP).

MATERIAL AND METHODS

The study group consisted of 717 women scheduled for reconstructive surgery due to POP. Risk factors, functional abnormalities along with symptoms affecting quality of life, were assessed by means of disease specific questionnaire. The stage of the disease was assessed after gynecological examination using POP-Q score.

RESULTS

The mean age of affected women with POP was 61,25 years (median 61), and mean BMI--27.62 (median--27.29). 80% of women were menopausal. Mean time of symptoms related to disease was 65,6 months; whereas the time relapsed from first doctor diagnosis of POP to hospital admission was 50.6 months. 97.4% affected women were multiparous. Only 1.21% women with POP were nulliparous. Family history of prolapse was found in 13.4% of patients, whereas familial positive history of urinary incontinence was 10%. Lower urinary tract symptoms (LUTS) among the analyzed group were as follows: frequency--almost 50%, urgency 32.2%, feeling of improper voiding -29,6% and voiding difficulty -17.7%. Functional disorders of lower bowel were found in 43% of patients and the most prevalent symptom was constipation (31%), followed by empting difficulty (12%), dyschesia (9%), and urge stool empting (7.7%). Cardiovascular diseases were found among 43% of respondents, whereas pulmonary diseases with chronic coughing were present in 20% of the analyzed population. Subjective POP symptoms reported by women were as follows: feeling of heaviness in lower abdomen--378%, perineal pain--27.8%, lumbosacral pain-34.2%, and abdominal pain--28.4%. Female sexual disorders were reported by 9,8% women and dyspareunia was found in 7.6% of responders. POP was the main reason for sexual abstinence only in 1 out of 10 patients. More than 30% of patients from the study group underwent previously pelvic surgery due to various reasons. POP related quality of life measured by VAS (Visual Analogue Scale) was 61.4 points (median--60). The most common finding during gynecological examination was cystocele--96.5%, followed by rectoenterocele--92.7%, and central defect--79%. Mean POP quantification was stage III in POP-Q scale. LUTS symptoms (urinary incontinence, urgency and voiding difficulties) were present among 81% of patients whereas lower gastrointestinal disorders (constipation, fecal incontinence, dyschesia) were found in 43% of women affected by POP.

CONCLUSIONS

Mean delay time from objective POP diagnosis until decision concerning surgical treatment was more than 5 years. The most common risk factors associated with POP were: multiparity with vaginal deliveries, obesity and aging. The most common defect found among patients with POP was cystocele, followed by rectoenterocele and central defect however most patients presented with advanced combined defects.

Circular permutation provides an evolutionary link between two families of calcium-dependent carbohydrate binding modules

The microbial deconstruction of the plant cell wall is a critical biological process, which also provides important substrates for environmentally sustainable industries. Enzymes that hydrolyze the plant cell wall generally contain non-catalytic carbohydrate binding modules (CBMs) that contribute to plant cell wall degradation. Here we report the biochemical properties and crystal structure of a family of CBMs (CBM60) that are located in xylanases. Uniquely, the proteins display broad ligand specificity, targeting xylans, galactans, and cellulose. Some of the CBM60s display enhanced affinity for their ligands through avidity effects mediated by protein dimerization. The crystal structure of vCBM60, displays a β-sandwich with the ligand binding site comprising a broad cleft formed by the loops connecting the two β-sheets. Ligand recognition at site 1 is, exclusively, through hydrophobic interactions, whereas binding at site 2 is conferred by polar interactions between a protein-bound calcium and the O2 and O3 of the sugar. The observation, that ligand recognition at site 2 requires only a β-linked sugar that contains equatorial hydroxyls at C2 and C3, explains the broad ligand specificity displayed by vCBM60. The ligand-binding apparatus of vCBM60 displays remarkable structural conservation with a family 36 CBM (CBM36); however, the residues that contribute to carbohydrate recognition are derived from different regions of the two proteins. Three-dimensional structure-based sequence alignments reveal that CBM36 and CBM60 are related by circular permutation. The biological and evolutionary significance of the mechanism of ligand recognition displayed by family 60 CBMs is discussed.

Restricted access of proteins to mannan polysaccharides in intact plant cell walls

How the diverse polysaccharides present in plant cell walls are assembled and interlinked into functional composites is not known in detail. Here, using two novel monoclonal antibodies and a carbohydrate-binding module directed against the mannan group of hemicellulose cell wall polysaccharides, we show that molecular recognition of mannan polysaccharides present in intact cell walls is severely restricted. In secondary cell walls, mannan esterification can prevent probe recognition of epitopes/ligands, and detection of mannans in primary cell walls can be effectively blocked by the presence of pectic homogalacturonan. Masking by pectic homogalacturonan is shown to be a widespread phenomenon in parenchyma systems, and masked mannan was found to be a feature of cell wall regions at pit fields. Direct fluorescence imaging using a mannan-specific carbohydrate-binding module and sequential enzyme treatments with an endo-β-mannanase confirmed the presence of cryptic epitopes and that the masking of primary cell wall mannan by pectin is a potential mechanism for controlling cell wall micro-environments.

Restricted access of proteins to mannan polysaccharides in intact plant cell walls

How the diverse polysaccharides present in plant cell walls are assembled and interlinked into functional composites is not known in detail. Here, using two novel monoclonal antibodies and a carbohydrate-binding module directed against the mannan group of hemicellulose cell wall polysaccharides, we show that molecular recognition of mannan polysaccharides present in intact cell walls is severely restricted. In secondary cell walls, mannan esterification can prevent probe recognition of epitopes/ligands, and detection of mannans in primary cell walls can be effectively blocked by the presence of pectic homogalacturonan. Masking by pectic homogalacturonan is shown to be a widespread phenomenon in parenchyma systems, and masked mannan was found to be a feature of cell wall regions at pit fields. Direct fluorescence imaging using a mannan-specific carbohydrate-binding module and sequential enzyme treatments with an endo-β-mannanase confirmed the presence of cryptic epitopes and that the masking of primary cell wall mannan by pectin is a potential mechanism for controlling cell wall micro-environments.

Carbohydrate-binding modules promote the enzymatic deconstruction of intact plant cell walls by targeting and proximity effects

Cell wall degrading enzymes have a complex molecular architecture consisting of catalytic modules and noncatalytic carbohydrate-binding modules (CBMs). The function of CBMs in cell wall degrading processes is poorly understood. Here, we have evaluated the potential enzyme-targeting function of CBMs in the context of intact primary and secondary cell wall deconstruction. The capacity of a pectate lyase to degrade pectic homogalacturonan in primary cell walls was potentiated by cellulose-directed CBMs but not by xylan-directed CBMs. Conversely, the arabinofuranosidase-mediated removal of side chains from arabinoxylan in xylan-rich and cellulose-poor wheat grain endosperm cell walls was enhanced by a xylan-binding CBM but less so by a crystalline cellulose-specific module. The capacity of xylanases to degrade xylan in secondary cell walls was potentiated by both xylan- and cellulose-directed CBMs. These studies demonstrate that CBMs can potentiate the action of a cognate catalytic module toward polysaccharides in intact cell walls through the recognition of nonsubstrate polysaccharides. The targeting actions of CBMs therefore have strong proximity effects within cell wall structures, explaining why cellulose-directed CBMs are appended to many noncellulase cell wall hydrolases.

[Predictors of smoking cessation after stroke]

Cigarette smoking is a major modifiable risk factor for stroke. Smoking dose dependently increases the risk of stroke, especially in patients below 75 years of age. Although smoking cessation is considered as one of the most effective methods of secondary stroke prevention, little is known about nicotine dependence and predictors of smoking cessation after stroke. Identification of such predictors could facilitate the development of anti-smoking interventions in post-stroke patients. Results of previous studies showed that smoking cessation is determined by the interplay of multiple factors, including sociodemographic (gender, age, race, living conditions, employment), clinical (functional status), psychobiological (nicotine dependence, depressed mood) and environmental (smoking household members) factors. Limitations of most studies were relatively small sample sizes and lack of verification of smoking status with a biochemical marker (e.g. expired CO). The aim of this article is to summarize current knowledge about predictors of smoking cessation after stroke.

[Foreign body in vagina--polyurethane foam. Case report]

This report presents the case of a 40-year-old woman hospitalized in the Department of Gynecology and Oncological Gynecology Military Institute of the Health Services, who was found to have had a foreign body (polyurethane foam) of significant amount for three days in her vagina. The foreign body was successfully removed during surgery and did not lead to any negative health consequences for the patient.

Reliability and clinical validity of a Polish version of the CONTILIFE: a quality of life questionnaire for urinary incontinence

INTRODUCTION AND HYPOTHESIS

The primary aim of the study was to translate and validate a Polish version of the CONTILIFE, a quality of life questionnaire. The clinical validity of the CONTILIFE was assessed against the number of urinary leaks, Valsalva leak point pressure (VLPP), and maximum urethral closure pressure (MUCP).

METHODS

One hundred women with stress urinary incontinence completed a Polish version of the CONTILIFE twice with a 4-day interval.

RESULTS

Internal consistency (Cronbach's alpha= 0.94) and test-retest reliability of the instrument (ICC = 0.96) were very good. A significant relationship was found between all the CONTILIFE dimension scores, the CONTILIFE global score, and the number of urinary leaks per week. A less significant relationship was found between VLPP, MUCP, and CONTILIFE dimension and global scores.

CONCLUSIONS

A Polish version of the CONTILIFE can be a reliable measure of quality of life in stress urinary incontinence patients.

Enzymatic treatments reveal differential capacities for xylan recognition and degradation in primary and secondary plant cell walls

The capacity of four xylan-directed probes (carbohydrate-binding modules CfCBM2b-1-2 and CjCBM15; monoclonal antibodies LM10 and LM11) to recognize xylan polysaccharides in primary and secondary cell walls of tobacco stem sections has been determined. Enzymatic removal of pectic homogalacturonan revealed differential recognition of xylans in restricted regions of cortical primary cell walls. Monoclonal antibody binding to these exposed xylans was more sensitive to xylanase action than carbohydrate-binding module (CBM) binding. In contrast, the recognition of xylans by CBMs in secondary cell walls of the same organ was more sensitive to xylanase action than the recognition of xylans by the monoclonal antibodies. A methodology was developed to quantify indirect immunofluorescence intensities, and to evaluate xylanase impacts. The four xylan probes were also used to detect xylan populations in chromatographic separations of solubilized cell wall materials from tobacco stems. Altogether, these observations reveal the heterogeneity of the xylans in plant cell walls. They indicate that although CBM and antibody probes can exhibit similar specificities against solubilized polymers, they can have differential capacities for xylan recognition in muro, and that the access of molecular probes and enzymes to xylan epitopes/ligands also varies between primary and secondary cell walls that are present in the same organ.

A protein synthesis inhibitor, cycloheximide does not alter cue-induced reinstatement of saccharin seeking

A large body of evidence indicates that reactivation of aversive memories leads to protein synthesis-dependent memory reconsolidation which can be disrupted by cycloheximide and other protein synthesis inhibitors. The aim of the present study was to investigate whether cycloheximide would alter reconsolidation of the associations involving discrete cues paired with a sweet reward in an appetitive instrumental task. Rats trained to lever press for 0.1% saccharin were repeatedly tested for cue-induced reinstatement of non-reinforced responding for saccharin. CHX (3 mg/kg, s.c.) or its vehicle was injected immediately after each reinstatement session. The protein synthesis inhibitor did not alter the ability of the saccharin-paired cues to reinstate saccharin seeking. The present results suggest that passive re-exposure to saccharin-paired discrete cues in the reinstatement procedure does not lead to any cycloheximide-sensitive reconsolidation of the original associations.

Alcohol relapse induced by discrete cues activates components of AP-1 transcription factor and ERK pathway in the rat basolateral and central amygdala

Alcohol-related cues may induce relapse to heavy alcohol drinking and promote molecular adaptations in discrete brain regions. An exact nature of these molecular alterations is still unknown. In the present study, rats trained to self-administer ethanol were tested for cue-induced reinstatement of ethanol seeking after 30 days of abstinence. Next, a detailed immunocytochemical analysis of c-Fos activation was performed within seven nuclei of the amygdala. In the second experiment, c-Fos activation after reinstatement of ethanol seeking induced by discrete cues was compared with the activation pattern of its putative partner (c-Jun) and regulators (extracellular signal-regulated kinases and c-Jun N-terminal kinases). Reexposure to ethanol-associated context cues (an extinction session) potentiated c-Fos expression within the basolateral and central amygdala. Repeated presentation of ethanol-associated discrete cues in an extinction/reinstatement session led to even stronger c-Fos activation in the latter nuclei. In the second experiment, reexposure to the ethanol-associated context and discrete cues activated both c-Jun and extracellular signal-regulated kinases (ERK1/2) in the basolateral amygdala. Our observations suggest that the basolateral and central amygdala may be specifically involved in alcohol-seeking behavior induced by discrete cues.

Taste responses in patients with Parkinson's disease

OBJECTIVE

Preclinical studies indicate that dopaminergic transmission in the basal ganglia may be involved in processing of both pleasant and unpleasant stimuli. Given this, the aim of the present study was to assess taste responses to sweet, bitter, sour, and salty substances in patients with Parkinson's disease (PD).

METHODS

Rated intensity and pleasantness of filter paper discs soaked in sucrose (10-60%), quinine (0.025-0.5%), citric acid (0.25-4.0%), or sodium chloride (1.25-20%) solutions was evaluated in 30 patients with PD and in 33 healthy controls. Paper discs soaked in deionised water served as control stimuli. In addition, reactivity to 100 ml samples of chocolate and vanilla milk was assessed in both groups. Taste detection thresholds were assessed by means of electrogustometry. Sociodemographic and neuropsychiatric data, including cigarette smoking, alcohol consumption, tea and coffee drinking, depressive symptoms, and cognitive functioning were collected.

RESULTS

In general, perceived intensity, pleasantness, and identification of the sucrose, quinine, citric acid, or sodium chloride samples did not differ between the PD patients and controls. Intensity ratings of the filter papers soaked in 0.025% quinine were significantly higher in the PD patients compared with the control group. No inter-group differences were found in taste responses to chocolate and vanilla milk. Electrogustometric thresholds were significantly (p = 0.001) more sensitive in the PD patients.

CONCLUSIONS

PD is not associated with any major alterations in responses to pleasant or unpleasant taste stimuli. Patients with PD may present enhanced taste acuity in terms of electrogustometric threshold.

Depressive symptoms and taste reactivity in humans

Animal studies suggest that induction of depression-like states may alter preference for sweet tastants. A major goal of the present study was to search for correlations between depressive symptoms measured by the Beck Depression Inventory (BDI) and taste responses to sweet and bitter substances. Thirty-three nonclinical volunteers rated intensity and pleasantness of chocolate and vanilla milk as well as of sucrose- and quinine-soaked filter paper disks. Reactivity to citric acid (sour) and sodium chloride (salty) was also tested with the paper disk methodology. Taste detection thresholds were assessed by means of electrogustometry. A weak inverse relationship was found between the BDI scores (range: 3-33) and rated intensity of paper disks soaked in 60% sucrose. No correlations were found between depressive symptoms and intensity, pleasantness or identification of the other samples. Similarly, there was no relationship between the BDI scores and responses to chocolate and vanilla milk. BDI scores were not associated with electrogustometric thresholds. These data suggest that depressive symptoms may not influence taste reactivity in nonclinical population.

Time-dependent changes in alcohol-seeking behaviour during abstinence

Exposure of alcohol addicts to alcohol-related environmental cues may elicit alcohol-seeking behaviour even after protracted abstinence. The purpose of the present study was to assess time-dependent changes in alcohol-seeking behaviour in rats trained to respond for alcohol. The rats were re-exposed to alcohol-associated stimuli after 1, 28 or 56 days of withdrawal. During the re-exposure session, the rats were first allowed to respond in extinction. Then, reinstatement of alcohol-seeking behaviour was evoked by a complex of discrete alcohol-associated cues (auditory and light cues combined with taste and smell of alcohol). Extinction behaviour depended on abstinence duration with maximal responding after 28-day abstinence. Reinstatement of alcohol-seeking behaviour evoked by the discrete cues was highest after 56-day abstinence. No correlations were found between individual alcohol intakes, extinction behaviour and cue-induced reinstatement. These results suggest that: (i) alcohol-seeking behaviour may become more intense after long-term imposed abstinence; (ii) alcohol self-administration, extinction behaviour, and reinstatement of alcohol-seeking behaviour may be regulated by separate neural mechanisms.

Dissociation of ethanol and saccharin preference in fosB knockout mice

The Fos family of transcription factors may play a key role in various forms of brain plasticity. Among different genes coding Fos proteins is the fosB gene. Protein products of the fosB gene are thought to be critically involved in neural adaptations produced by chronic treatment with drugs of abuse. fosB gene transcription leads to accumulation of full-length FosB as well as its truncated form, deltafosB. Stable isoforms of deltafosB called chronic FRAs accumulate in the brain after chronic administration of various drugs of abuse. The purpose of the present study was to evaluate the role of the fosB gene in two-bottle choice ethanol self-administration. For this aim, ethanol (2-8% v/v) intake and preference was assessed in fosB mutant (n=17) and wild-type (WT) mice (n=16). For comparison, consumption of saccharin (0.05-0.8% w/v) and quinine (15-960 microM) solutions was assessed in the same animals. Ethanol preference in both groups varied from around 50% for the lowest to 20% for the highest ethanol concentration. Neither ethanol intake (g/kg) nor preference differed between the two genotypes. In contrast, saccharin preference, but not intake, was higher in the fosB mutants. Only slight and inconsistent between-group differences were observed in terms of quinine preference. The present results suggest that permanent elimination of fosB gene products does not alter ethanol intake but may enhance preference for sweet solutions in mice.

Ethanol-reinforced behaviour predicts acquisition but not extinction of cocaine self-administration in the rat

AIMS

The aim of the present study was to evaluate the relationship between operant oral ethanol self-administration and intravenous (i.v.) cocaine self-administration in male Wistar rats.

METHODS

Twenty-four rats were trained to lever press for 8% v/v ethanol in the sucrose-fading procedure. The subjects with the highest (high ethanol responders [HER], n = 7) and lowest (low ethanol responders [LER], n = 7) ethanol intakes were selected for further experiments. After a wash-out period, during which i.v. catheters were implanted, the HER and LER were trained to nose-poke for cocaine infusions (0.33 mg/kg/infusion, a FR1 schedule) for nine daily sessions.

RESULTS

The HER emitted more 'active' nose-pokes and obtained more cocaine infusions during sessions 2-4. Drug-seeking behaviour in the absence of cocaine reinforcement was then assessed for three consecutive extinction sessions. No between-group differences were found in terms of extinction of cocaine seeking. Locomotor responses to a novel environment were also similar in both groups.

CONCLUSIONS

The present results suggest that a propensity to self-administer ethanol predicts more rapid acquisition of cocaine self-administration behaviour but does not influence subsequent behaviour during extinction.

Different pattern of brain c-Fos expression following re-exposure to ethanol or sucrose self-administration environment

Exposure of alcohol addicts to alcohol-related environmental cues may elicit alcohol-seeking behavior and lead to relapse to heavy drinking. The aim of the present study was to identify brain regions activated by alcohol (ethanol)-related stimuli in Wistar rats trained to lever press for 8% ethanol solution in operant self-administration cages. Ethanol self-administration was stabilized in a maintenance phase, which lasted for 30 days. c-Fos protein expression was used as a marker of neuronal activation.Re-exposure to ethanol self-administration environment after 30-day but not after 24-h abstinence increased the number of Fos-positive nuclei in the thalamic paraventricular nucleus, granular insular cortex and medial prefrontal cortex. In general, no differences were found in c-Fos protein expression between the rats allowed to self-administer alcohol and the subjects exposed only to alcohol-related stimuli. In contrast, no increase in c-Fos immunoreactivity was observed in rats trained to lever press for sucrose solution and exposed to sucrose-related environmental stimuli after 30-day abstinence. Taken together, these results suggest that at least some thalamo-cortical circuits become more responsive to ethanol-paired stimuli after prolonged abstinence and that ethanol- and sucrose-seeking behavior may be regulated by partially different neural mechanism(s).

Relationship between dopamine D2 receptor-associated responses and operant ethanol self-administration in the rat: a factor analysis

AIMS

To characterize the relationship between dopamine D(2) receptor-associated responses and operant ethanol self-administration in Wistar rats.

METHODS

Thirty-two rats were first tested for apomorphine-induced sniffing and raclopride-induced catalepsy. Subsequently, the same subjects were initiated to lever press for ethanol in the sucrose-fading procedure. The subjects were allowed to respond for 8% v/v ethanol for 20 days. A factor analysis was used to characterize the relationship between D(2)-associated responses and parameters of sucrose and ethanol self-administration.

RESULTS

The analysis revealed three factors accounting for 88.3% of the total variability. The first factor comprised only parameters of ethanol-reinforced behaviour. Parameters of sucrose self-administration and cataleptic responses to raclopride loaded heavily on the second and third factors, respectively. None of the factors comprised apomorphine-induced stereotypy.

CONCLUSIONS

It appears that there is no relationship between apomorphine-induced sniffing, raclopride-induced catalepsy and operant responding for ethanol in Wistar rats. Our results, combined with previous reports, suggest that D(2) receptors are not primarily involved in the regulation of ethanol reinforcement.

Chorda tympani nerve transection does not alter operant oral self-administration of ethanol in the rat

In experimental conditions, it has been suggested that taste factors may contribute to ethanol preference in rodents. The aim of the current study was to assess the effects of transection of a gustatory branch of the seventh cranial nerve, the chorda tympani (CT), on operant self-administration of ethanol in rats. Male Wistar rats were trained to lever press for 8% [volume/volume (vol./vol.)] ethanol solution. When 8% ethanol intake stabilized, the CT nerve was transected bilaterally in six subjects. Another group received sham operations. There were no between-group differences in terms of self-administration of 8% ethanol, either before or after surgery. In addition, self-administration of 2% and 4% ethanol, measured after surgery, did not differ between the groups. In a control experiment, two-bottle consumption of as well as preference for 0.625% [weight/volume (wt./vol.)] sucrose were significantly decreased in the lesioned subjects. The results may indicate that gustatory input of the CT nerve is not necessary for maintenance of operant oral self-administration of ethanol.

Sucrose self-administration predicts only initial phase of ethanol-reinforced behaviour in Wistar rats

AIMS

To characterize the relationship between the sucrose- and ethanol-reinforced behaviour in Wistar rats.

METHODS

Subjects (n = 31) were trained to lever press for 8% (v/v) ethanol in an operant procedure where increasing concentrations of ethanol were introduced in the presence of 8% (w/v) sucrose. The sucrose concentration was subsequently decreased from 8 to 0%. Subjects were allowed to stabilize their intake of 8% ethanol over the next 20 days.

RESULTS

Self-administration of 8% sucrose (ml/kg) significantly correlated with ethanol consumption (g/kg) on days 1-5 of the 8% ethanol self-administration period. This relationship completely disappeared during the subsequent weeks of ethanol self-administration (days 6-20).

CONCLUSIONS

The results of the present study, combined with our previous findings, may indicate that self-administration of sucrose predicts only the initial phase of ethanol-taking behaviour in Wistar rats.