Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “double robustness”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources

Sexual psychophysiology and effects of sildenafil citrate in oestrogenised women with acquired genital arousal disorder and impaired orgasm: a randomised controlled trial.

OBJECTIVE: Some postmenopausal women lose genital sexual responsivity despite preserved subjective sexual arousal from non-genital stimuli. When oestrogen replacement is without benefit, both the underlying pathophysiology and management of this acquired genital female sexual arousal disorder are unclear. We aimed to study the effect of sildenafil on sexual arousal and orgasmic functioning of such women. Secondly, we aimed to explore the concordance between a detailed historical assessment of genital response in real life, with laboratory vaginal photoplethysmographic assessment of genital vasocongestion. DESIGN: Session one consisted of a semi-structured clinical interview to assess real life sexual arousal. Session two employed vaginal pulse amplitude and self-report questionnaire assessment of erotica-induced sexual arousal. Sessions three and four were a randomised, double-blind, placebo-controlled crossover administration of sildenafil on orgasm latency, intensity, perception of genital congestion and subjective arousal to erotica plus clitoral vibrostimulation. SETTING: University associated Sexual Medicine Clinic and Psychophysiology Laboratory. SAMPLE: Volunteer sample of 34 oestrogenised postmenopausal women with acquired genital female sexual arousal disorder and impaired orgasm. METHODS: Sildenafil (50 mg) or placebo administered over two laboratory sessions. MAIN OUTCOME MEASURES: Orgasm latency and intensity during drug sessions; subjective and psychophysiological sexual arousal during photoplethysmography session. RESULTS: The erotic video significantly increased subjective sexual arousal in all women. Vaginal pulse amplitude responses varied from robust to absent. Although across all women, sildenafil improved neither arousal nor orgasm, subsequent analyses comparing high versus low vaginal pulse amplitude responders revealed significantly reduced latency to orgasm, and increased subjective sexual arousal and perception of genital arousal in the latter group of women. CONCLUSION: The data suggest that oestrogenised postmenopausal women with genital female sexual arousal disorder and orgasmic impairment based only on clinical assessment do not benefit from sildenafil. However, the photoplethysmograph had predictive value-those women showing low vaginal pulse amplitude response benefited from sildenafil compared with women with a higher response. Thus, oestrogenised women diagnosed with acquired genital female sexual arousal disorder may be a heterogeneous group and the photoplethysmograph might be useful in their further characterisation.

Adult↗

Long-term safety and efficacy of alosetron in women with severe diarrhea-predominant irritable bowel syndrome.

OBJECTIVES: To assess long-term safety and efficacy of alosetron in women with severe, chronic diarrhea-predominant IBS and in a subset having more frequent urgency (i.e., bowel urgency at least 10 of 14 days during screening). METHODS: Randomized patients received either alosetron 1 mg (n = 351) or placebo (n = 363) twice daily during a 48-wk, double-blind study. The primary endpoint was the 48-wk average rate of adequate relief of IBS pain and discomfort. Secondary endpoints included 48-wk average satisfactory control rates of urgency, stool frequency, stool consistency, and bloating. Other efficacy endpoints were average monthly adequate relief and urgency control rates and impact of provided rescue medication. RESULTS: Alosetron-treated patients had significantly greater 48-wk average adequate relief (p= 0.01) and urgency control (p < 0.001) rates, regardless of rescue medication use, compared with placebo. Results in subjects with more frequent urgency were more robust than those in the overall population (p= 0.005). In weeks without rescue medication use, satisfactory control rates for stool frequency and stool consistency were significantly greater in alosetron-treated patients than placebo. Alosetron-treated patients had significantly greater adequate relief than placebo-treated patients (p < 0.05) in 9 of 12 months and significantly greater urgency control (p < 0.001) in all months. Adequate relief and urgency control were maintained throughout the treatment. Adverse events and serious adverse events were similar between treatment groups, except for constipation. Neither ischemic colitis nor serious events related to bowel motor dysfunction was reported. CONCLUSIONS: Long-term use of alosetron is effective and well-tolerated in women with chronic, diarrhea-predominant IBS, including those with more frequent urgency.

Abdominal Pain↗

A genome wide search for alcoholism susceptibility genes.

Alcoholism is currently one of the most serious public health problems in the US. Lifetime prevalence rates are relatively high with one in five men and one in 12 women meeting criteria for this condition. Identification of genetic loci conferring an increased susceptibility to developing alcohol dependence could strengthen prevention efforts by informing individuals of their risk before abusive drinking ensues. Families identified through a double proband methodology have provided an exceptional opportunity for gene-finding because of the increased recurrence risks seen in these sibships. A total of 360 markers for 22 autosomes were spaced at an average distance of 9.4 cM and genotyping performed for 330 members of these multiplex families. Extensive clinical data, personality variation, and event-related potential characteristics were available for reducing heterogeneity and detecting robust linkage signals. Multipoint linkage analysis using different analytic strategies give strong support for loci on chromosomes 1, 2, 6, 7, 10, 12, 14, 16, and 17.

Age Factors↗

Symmetry and frustration in protein energy landscapes: a near degeneracy resolves the Rop dimer-folding mystery.

Protein folding has become one of the best understood biochemical reactions from a kinetic viewpoint. The funneled energy landscape, a consequence of the minimal frustration achieved by evolution in sequences, explains how most proteins fold efficiently and robustly to their functional structure and allows robust prediction of folding kinetics. The folding of Rop (repressor of primer) dimer is exceptional because some of its mutants with a redesigned hydrophobic core both fold and unfold much faster than the WT protein, which seems to conflict with a simple funneled energy landscape for which topology mainly determines the kinetics. We propose that the mystery of Rop folding can be unraveled by assuming a double-funneled energy landscape on which there are two basins that correspond to distinct but related topological structures. Because of the near symmetry of the molecule, mutations can cause a conformational switch to a nearly degenerate yet distinct topology or lead to a mixture of both topologies. The topology predicted to have the lower free-energy barrier height for folding was further found by all-atom modeling to give a better structural fit for those mutants with the extreme folding and unfolding rates. Thus, the non-Hammond effects can be understood within energy-landscape theory if there are in fact two different but nearly degenerate structures for Rop. Mutations in symmetric and regular structures may give rise to frustration and thus result in degeneracy.

Biophysical Phenomena↗

Effect of ramipril on insulin sensitivity in obese patients. Time-course study of glucose infusion rate during euglycaemic hyperinsulinaemic clamp.

To assess the effects of angiotensin converting enzyme (ACE) inhibitor on insulin action in obesity, five normotensive non-diabetic obese women were examined on two occasions as part of a double-blind, randomized, cross-over study involving ten days of treatment with either 1.25 mg ramipril or placebo. The study consisted of a euglycaemic hyperinsulinaemic clamp (two periods of insulin infusion at rates of 0.4 and 1 mU/kg/min, 2 h for each step) combined with indirect calorimetry. The most notable results involved a significantly faster time-course of glucose infusion rates during the first 30 min of each insulin infusion period [analysed by calculating slopes (S1 and S2)] after ramipril than placebo administration. The mean glucose infusion rates reached during the last 30 min of each insulin infusion period (G1 and G2), as well as the increases in carbohydrate oxidation rates during the clamp (C1-C0 and C2-C0) and the decreases in plasma nonesterified fatty acids (A0-A1 and A0-A2), were not significantly different after ramipril and placebo. According to robust principal component analysis of S1, S2, G1, G2, C1, C2, A1 and A2 (orthogonally to C0 and A0), insulin sensitivity was improved with ramipril as compared to placebo (p = 0.013). This study strongly suggests that a low dose of an ACE inhibitor increases the activation phase of insulin action in normotensive nondiabetic obese patients and may accelerate insulin action.

Adult↗

Serotonergic anxiolytics in the treatment of panic disorder: a controlled study with buspirone.

The efficacy of buspirone for panic disorder was tested in 60 patients who met Diagnostic and Statistical Manual of Mental Disorders (3rd ed.) criteria for panic disorder or agoraphobia with panic attacks. Patients were randomly assigned to treatment with buspirone (mean dose 29.5 mg/day), imipramine (mean dose 140 mg/day), or placebo, and treated for 8 weeks after a 4- to 7-day placebo lead-in period. Patients with 4 or fewer attacks per month and those without attacks at the baseline visit were excluded from panic frequency comparisons. Both buspirone and imipramine tended to be better than placebo on total number of panic attacks, global psychopathology, and the Hamilton Anxiety rating scale, but end point differences among treatments were not statistically significant. At the end of the study, 25% of the buspirone patients were panic-free, as were 7% of the imipramine patients and 14% of the placebo patients; again, these differences were not statistically significant. The results of this study were inconclusive, partly because of the relatively small number of patients (10-11) completing the study in each treatment group, and partly because of a robust placebo response in this population. Possible reasons for this high placebo response are discussed, as well as suggestions for changes in study design for future studies.

Adult↗

The innate immune facet of brain: human neurons express TLR-3 and sense viral dsRNA.

Inflammation is an important factor in the pathogenesis of neurodegenerative diseases, such as Alzheimer's disease or multiple sclerosis, and during microbial infections of the nervous system. Glial cells were thought to be the main contributor for cytokine and chemokine production and Toll-like receptor (TLR) expression in the brain. Here, we report that human neurons express TLR-3, a major receptor in virus-mediated innate immune response. We established that these cells can mount a strong inflammatory response characterized by the expression of inflammatory cytokines (TNF-alpha, IL-6), chemokines (CCL-5 and CXCL-10), and antiviral molecules (2'5'OAS and IFN-beta) after treatment with dsRNA - a by-product of viral infection and ligand of TLR-3. This work firmly establishes that human neurons, in absence of glia, have the intrinsic machinery to trigger robust inflammatory, chemoattractive, and antiviral responses.

Brain↗

Serotonin regulation of the human stress response.

Acute tryptophan depletion (ATD) is a technique that has been used to evaluate the effects on humans of acutely reducing serotonin neurotransmission. We have developed a model using a single breath of 35% CO(2) that activates the hormonal axis and produces autonomic and behavioural arousal, thus modelling a stress response. This study combines ATD and single breath 35% CO(2) inhalation to study stress responses in volunteers. A randomised, double-blinded, placebo-controlled, cross-over trial involving 14 healthy adult volunteers aged between 18 and 65 years was undertaken. Subjects underwent double-blind tryptophan depletion over 2 days and were then crossed over 1 week later. During each study day, at the time of peak depletion, participants were single blinded to receive a single breath of 35% CO(2) or air. This was followed 40 min later by the other gas. Psychological outcomes were assessed with the Spielberger State Anxiety Inventory (SSAI), Visual Analogue Scales (VAS), Panic Inventory (PI), Panic and Agoraphobia Scale (PSI) and Beck Depression Inventory (BDI). Physiological outcome was measured by serial plasma cortisol, prolactin and tryptophan levels, pulse and blood pressure. Tryptophan depletion did not exacerbate 35% CO(2) inhalation effects on anxiety symptoms. Single breath CO(2) robustly increased plasma cortisol levels in comparison to an air inhalation; this was less certain for prolactin levels. ATD influenced the HPA axis (associated with higher cortisol levels), apparently independent of CO(2) or air inhalation stressors. ATD and 35% CO(2) inhalation both induced a pressor response and bradycardia in these normal volunteers. Thirty-five percent CO(2) inhalation and ATD independently activate the human stress response, but do not appear to produce synergistic effects when combined, at least for the conditions produced in this study.

Adult↗

A double-blind controlled trial of bilateral fetal nigral transplantation in Parkinson's disease.

Thirty-four patients with advanced Parkinson's disease participated in a prospective 24-month double-blind, placebo-controlled trial of fetal nigral transplantation. Patients were randomized to receive bilateral transplantation with one or four donors per side or a placebo procedure. The primary end point was change between baseline and final visits in motor component of the Unified Parkinson's Disease Rating Scale in the practically defined off state. There was no significant overall treatment effect (p = 0.244). Patients in the placebo and one-donor groups deteriorated by 9.4 +/- 4.25 and 3.5 +/- 4.23 points, respectively, whereas those in the four-donor group improved by 0.72 +/- 4.05 points. Pairwise comparisons were not significant, although the four-donor versus placebo groups yielded a p value of 0.096. Stratification based on disease severity showed a treatment effect in milder patients (p = 0.006). Striatal fluorodopa uptake was significantly increased after transplantation in both groups and robust survival of dopamine neurons was observed at postmortem examination. Fifty-six percent of transplanted patients developed dyskinesia that persisted after overnight withdrawal of dopaminergic medication ("off"-medication dyskinesia). Fetal nigral transplantation currently cannot be recommended as a therapy for PD based on these results.

Adult↗

A new type of model-based Roentgen stereophotogrammetric analysis for solving the occluded marker problem.

Roentgen stereophotogrammetric analysis (RSA) measures micromotion of an orthopaedic implant with respect to its surrounding bone. A problem in RSA is that the markers are sometimes overprojected by the implant itself. This study describes the so-called Marker Configuration Model-based RSA (MCM-based RSA) that is able to measure the pose of a rigid body in situations where less than three markers could be detected in both images of an RSA radiograph. MCM-based RSA is based on fitting a Marker Configuration model (MC-model) to the projection lines from the marker projection positions in the image to their corresponding Roentgen foci. An MC-model describes the positions of markers relative to each other and is obtained using conventional RSA. We used data from 15 double examinations of a clinical study of total knee prostheses and removed projections of the three tibial component markers, simulating occlusion of markers. The migration of the tibial component with respect to the bone, which should be zero, for the double examination is a measure of the accuracy of algorithm. With the new algorithm, it is possible to estimate the pose of a rigid body of which one or two markers are occluded in one of the images of the RSA radiograph with high accuracy as long as a proper MC-model of the markers in the rigid body is available. The new algorithm makes RSA more robust for occlusion of markers. This improves the results of clinical RSA studies because the number of lost RSA follow-up moments is reduced.

Biomechanical Phenomena↗

The role of transmembrane span 2 in the structure and function of subunit a of the ATP synthase from Escherichia coli.

The importance of the second transmembrane span of subunit a of the ATP synthase from Escherichia coli has been established by two approaches. First, biochemical analysis of five cysteine-substitution mutants, four of which were previously constructed for labeling experiments, revealed that only D119C, found within the second transmembrane span, was deleterious to ATP synthase function. This mutant had a greatly reduced growth yield, indicating inefficient ATP synthesis, but it retained a significant level of ATP-driven proton translocation and sensitivity to N,N(')-dicyclohexyl-carbodiimide, indicating more robust function in the direction of ATP hydrolysis. Second, the entire second transmembrane span was probed by alanine-insertion mutagenesis at six different positions, from residues 98 to 122. Insertions at the central four positions from residues 107 to 117 resulted in the inability to grow on succinate minimal medium, although normal levels of membrane-bound ATPase activity and significant levels of subunit a were detected. Double mutants were constructed with a mutation that permits cross-linking to the b subunit. Cross-linked products in the mutant K74C/114iA were seen, indicating no major disruption of the a-b interface due to the insertion at 114. Analysis of the K74C/110iA double mutant indicated that K74C is a partial suppressor of 110iA. In summary, the results support a model in which the amino-terminal, cytoplasmic end of the second transmembrane span has close contact with subunit b, while the carboxy-terminal, periplasmic end is important for proton translocation.

Bacterial Proton-Translocating ATPases↗

phyA dominates in transduction of red-light signals to rapidly responding genes at the initiation of Arabidopsis seedling de-etiolation.

Contrary to expectations based on the visible phenotypic behavior of seedlings undergoing de-etiolation in response to continuous red light (Rc), previous gene expression profiling showed that one or more of the five-membered phytochrome (phy) family of Arabidopsis, other than phyB, is predominantly responsible for transducing the Rc signals to light-responsive genes. To begin to identify which phys are involved, and to define potential primary targets of phy signaling, we have examined the genome-wide expression profiles of genes responding to Rc within 1 h (early response genes) of initial exposure of dark-grown wild-type, phyA, phyB and phyAphyB double mutant seedlings to the light signal. The data show that phyA has a quantitatively dominant role in Rc-induced expression of these early response genes, that phyB has minimal detectable regulatory activity in the presence of phyA, but assumes a quantitatively larger role in its absence, and that phyA and phyB combined are responsible for the full extent of Rc responsiveness of 96% of these genes. No evidence was obtained of a significant role for the remaining family members, phyC, phyD or phyE, in this process. In striking contrast, Rc-imposed repression of early response gene expression remains quantitatively strong in the phyAphyB double mutant, as well as the monogenic mutants, suggesting a significant role for one or more of the other three phys in this response. Examination of the established or predicted functional roles of the early response genes indicates that genes encoding transcription factors represent the largest single category, at a frequency three times their prevalence genome-wide. This dominance is particularly striking among those genes responding most robustly to the Rc signal, where >50% are classified as involved in transcriptional regulation, suggesting that these may have potentially primary regulatory roles at the interface between phy signaling and the light-responsive transcriptional network. Integration of the present data with those of a previous genome-scale transcriptional analysis of a pif3 mutant, suggests a complex network involving perception and transduction of inductive Rc signals by both phyA and phyB through both PIF3 and other undefined signaling partners to early response genes.

Arabidopsis↗

Predictors of response in generalized social phobia: effect of age of onset.

Selective serotonin reuptake inhibitors (SSRIs) are the gold standard for the pharmacological treatment of generalized social phobia (GSP). However, little is known about the predictors of response to treatment. Two hundred and four outpatients with GSP were randomized to sertraline (Zoloft) or placebo, for a 20-week double-blind study, with a flexible dose range of sertraline 50 to 200 mg/d. Response was defined as the percentage of patients with a Clinical Global Impression-Improvement scale (CGI-I) of 1 (very much improved) or 2 (much improved). Outcome analyses were conducted using regression models including treatment group as a categorical predictor and study visit as a repeated measure. Dependent measures included Marks Fear Questionnaire (MFQ), Brief Social Phobia Scale (BSPS), CGI-I, and Sheehan Disability Scale (SDS). We investigated several possible predictors of response to treatment including DSM-IV comorbidity, age, sex, age of onset of GSP, and duration of illness. Patients with later-onset (especially adult-onset) GSP tend to have a better response to treatment than those with earlier-onset GSP. This result generally appears in our analyses as a 2-way interaction, where the association with response is greatest for patients with adult-onset GSP (in contrast to those with child or adolescent onset). This finding is most robust for symptom measures, but is still apparent for the Sheehan measure of disability at work. This advantage for later-onset GSP can be accounted for neither by severity of illness nor by duration of illness. Superior treatment outcome for later-onset GSP may be mediated by the degree of social and family disability.

Adolescent↗

Relationships between changes in plasma lipid transfer proteins and apolipoprotein B-100 kinetics during fenofibrate treatment in the metabolic syndrome.

The aim of the present study was to investigate the association between changes in apoB (apolipoprotein B-100) kinetics and plasma PLTP (phospholipid transfer protein) and CETP (cholesteryl ester transfer protein) activities in men with MetS (the metabolic syndrome) treated with fenofibrate. Eleven men with MetS underwent a double-blind cross-over treatment with fenofibrate (200 mg/day) or placebo for 5 weeks. Compared with placebo, fenofibrate significantly increased the FCRs (fractional catabolic rates) of apoB in VLDL (very-low-density lipoprotein), IDL (intermediate-density lipoprotein) and LDL (low-density lipoprotein) (all P<0.01), with no significant reduction (-8%; P=0.131) in VLDL-apoB PR (production rate), but an almost significant increase (+15%, P=0.061) in LDL-apoB PR. Fenofibrate significantly lowered plasma TG [triacylglycerol (triglyceride); P<0.001], the VLDL-TG/apoB ratio (P=0.003) and CETP activity (P=0.004), but increased plasma HDL (high-density lipoprotein)-cholesterol concentration (P<0.001) and PLTP activity (P=0.03). The increase in PLTP activity was positively associated with the increase in both LDL-apoB FCR (r=0.641, P=0.034) and PR (r=0.625, P=0.040), and this was independent of the fall in plasma CETP activity and lathosterol level. The decrease in CETP activity was positively associated with the decrease in VLDL-apoB PR (r=0.615, P=0.044), but this association was not robust and not independent of changes in PLTP activity and lathosterol levels. Hence, in MetS, the effects of fenofibrate on plasma lipid transfer protein activities, especially PLTP activity, may partially explain the associated changes in apoB kinetics.

Adult↗

Cost-effectiveness of inhaled beta-agonists v. oral salbutamol in asthma: a randomized double-blind cross-over study.

BACKGROUND: Oral beta-stimulants are widely used in the management of chronic asthma in India, in spite of evidence suggesting the superiority of inhaled medication in achieving maximum bronchodilatation. An economic evaluation was performed in a randomized double-blind cross-over trial to evaluate the role of adjuvant oral beta-stimulants in the treatment of asthma. METHODS: Patients who had seasonal or perennial asthma and were using metered dose inhalers for control of symptoms were randomly selected for the study. They received either 4 mg of oral salbutamol or placebo as adjuvant treatment. During the study they controlled their symptoms by adjusting the dose of the inhaler medication. A cost minimization technique was used to assess the economic impact of this intervention in the treatment and control periods. A sensitivity analysis was performed to assess the robustness of the conclusions. RESULTS: The mean cost was significantly greater in the treatment period and a patient lost approximately Rs 20 per month (CI: 13 to 27; p = 0.001) as a result of the adjuvant treatment. There was no significant difference in the quality of life or peak expiratory flow rate during the two periods. The patients also noted mild but significantly increased tremors (p = 0.01) and palpitations (p = 0.001) during the treatment period. There was no treatment-to-period interaction. CONCLUSION: Adjuvant oral beta-agonists do not improve the quality of life or bronchodilatation in asthmatics using an inhaled beta-agonist for control of symptoms.

Administration, Inhalation↗

nef gene is required for robust productive infection by simian immunodeficiency virus of T-cell-rich paracortex in lymph nodes.

The pathogenesis of AIDS virus infection in a nonhuman primate AIDS model was studied by comparing plasma viral loads, CD4(+) T-cell subpopulations in peripheral blood mononuclear cells, and simian immunodeficiency virus (SIV) infection in lymph nodes for rhesus macaques infected with a pathogenic molecularly cloned SIVmac239 strain and those infected with its nef deletion mutant (Deltanef). In agreement with many reports, whereas SIVmac239 infection induced AIDS and depletion of memory CD4(+) T cells in 2 to 3 years postinfection (p.i.), Deltanef infection did not induce any manifestation associated with AIDS up to 6.5 years p.i. To explore the difference in SIV infection in lymphoid tissues, we biopsied lymph nodes at 2, 8, 72, and 82 weeks p.i. and analyzed them by pathological techniques. Maximal numbers of SIV-infected cells (SIV Gag(+), Env(+), and RNA(+)) were detected at 2 weeks p.i. in both the SIVmac239-infected animals and the Deltanef-infected animals. In the SIVmac239-infected animals, most of the infected cells were localized in the T-cell-rich paracortex, whereas in the Deltanef-infected animals, most were localized in B-cell-rich follicles and in the border region between the paracortex and the follicles. Analyses by double staining of CD68(+) macrophages and SIV Gag(+) cells and by double staining of CD3(+) T cells and SIV Env(+) cells revealed that SIV-infected cells were identified as CD4(+) T cells in either the SIVmac239 or the Deltanef infection. Whereas the many functions of Nef protein were reported from in vitro studies, our finding of SIVmac239 replication in the T-cell-rich paracortex in the lymph nodes supports the reported roles of Nef protein in T-cell activation and enhancement of viral infectivity. Furthermore, the abundance of SIVmac239 infection and the paucity of Deltanef infection in the T-cell-rich paracortex accounted for the differences in viral replication and pathogenicity between SIVmac239 and the Deltanef mutant. Thus, our in vivo study indicated that the nef gene enhances SIV replication by robust productive infection in memory CD4(+) T cells in the T-cell-rich region in lymphoid tissues.

Animals↗

GASepo-a software solution for quantitative analysis of digital images in Epo doping control.

A software has been developed that is aimed at quantitative analysis of images acquired by isoelectric focusing and double blotting procedures used for recombinant erythropoietin doping control. It represents a unified and easy-to-use tool for Epo doping experts in WADA accredited laboratories. It is based on image segmentation philosophy that enables identification of individual bands whose characteristics are needed for evaluation of the Epo doping positivity criteria. Several modules implemented in the GASepo software include an original know how, in particular, the method of robust calculation of the cut-off line, band segmentation and classification algorithms. GASepo is being used in several doping control laboratories worldwide.

Algorithms↗

The myofibroblast is the predominant plasminogen activator inhibitor-1-expressing cell type in human breast carcinomas.

The tumor level of plasminogen activator inhibitor-1 (PAI-1) is an informative biochemical marker of a poor prognosis in several cancer types. However, the tumor biological functions of PAI-1 and the identity of PAI-1-expressing cells are controversial. With the aim of immunohistochemically localizing PAI-1 in formalin-fixed, paraffin-embedded invasive ductal breast carcinoma samples, we raised new polyclonal antibodies against PAI-1 from different expression systems. The antibodies were affinity purified by absorption on immobilized preparations of PAI-1 different from those used for immunization. The specificity of the antibodies was ensured by immunoblotting analysis. In immunohistochemistry, the staining pattern obtained with the antibodies showed a good correlation with the PAI-1 mRNA expression pattern. In all 25 cases analyzed, PAI-1 immunoreactivity was predominantly localized in fibroblast-like cells. Double-immunofluorescence analyses showed co-expression of PAI-1 and alpha-smooth muscle actin in these cells, suggesting that they are myofibroblasts. PAI-1 was also seen in some myoepithelial cells surrounding occasional foci of ductal carcinoma in situ (9 of 25), some endothelial cells (8 of 25), some cancer cells (3 of 25), and some mast cells (6 of 25). In conclusion, we have provided a robust immunohistochemical procedure for detection of PAI-1 and shown that the majority of the PAI-1-expressing cells in invasive ductal breast carcinomas are myofibroblasts.

Actins↗