Overview of systematic reviews of risk factors for prosthetic joint infection

BACKGROUND

Prosthetic joint infection is one of the most serious complications in orthopedics. Prognostic systematic reviews (SR) detecting and assessing factors related to prosthetic joint infection, allow better prediction of risk and implementation of preventive measures. Although prognostic SR are increasingly frequent, their methodological field presents some knowledge gaps.

PURPOSE

To carry out an overview of SR assessing risk factors for prosthetic joint infection, describing and synthesizing their evidence. Secondarily, to assess the risk of bias and methodological quality.

MATERIAL AND METHODS

We conducted a bibliographic search in 4databases (May 2021) to identify prognostic SR evaluating any risk factor for prosthetic joint infection. We evaluated risk of bias with the ROBIS tool, and methodological quality with a modified AMSTAR-2 tool. We computed the overlap degree study between included SR.

RESULTS

Twenty-three SR were included, studying 15 factors for prosthetic joint infection, of which, 13 had significant association. The most frequently studied risk factors were obesity, intra-articular corticosteroids, smoking and uncontrolled diabetes. Overlapping between SR was high for obesity and very high for intra-articular corticoid injection, smoking and uncontrolled diabetes. Risk of bias was considered low in 8SRs (34.7%). The modified AMSTAR-2 tool showed important methodological gaps.

CONCLUSIONS

Identification of procedural-modifiable factors, such as intra-articular corticoids use, can give patients better results. Overlapping between SR was very high, meaning that some SR are redundant. The evidence on risk factors for prosthetic joint infection is weak due to high risk of bias and limited methodological quality.

[Translated article] Overview of systematic reviews of risk factors for prosthetic joint infection

BACKGROUND

Prosthetic joint infection is one of the most serious complications in orthopedics. Prognostic systematic reviews (SRs) detecting and assessing factors related to prosthetic joint infection, allow better prediction of risk and implementation of preventive measures. Although prognostic SRs are increasingly frequent, their methodological field presents some knowledge gaps.

PURPOSE

To carry out an overview of SR assessing risk factors for prosthetic joint infection, describing and synthesizing their evidence. Secondarily, to assess the risk of bias and methodological quality.

MATERIAL AND METHODS

We conducted a bibliographic search in 4 databases (May 2021) to identify prognostic SR evaluating any risk factor for prosthetic joint infection. We evaluated risk of bias with the ROBIS tool, and methodological quality with a modified AMSTAR-2 tool. We computed the overlap degree study between included SR.

RESULTS

Twenty-three SRs were included, studying 15 factors for prosthetic joint infection, of which, 13 had significant association. The most frequently studied risk factors were obesity, intra-articular corticosteroids, smoking and uncontrolled diabetes. Overlapping between SR was high for obesity and very high for intra-articular corticoid injection, smoking and uncontrolled diabetes. Risk of bias was considered low in 8 SRs (34.7%). The modified AMSTAR-2 tool showed important methodological gaps.

CONCLUSIONS

Identification of procedural-modifiable factors, such as intra-articular corticoids use, can give patients better results. Overlapping between SR was very high, meaning that some SRs are redundant. The evidence on risk factors for prosthetic joint infection is weak due to high risk of bias and limited methodological quality.

Working together for the family: determination of HER oncogene co-amplifications in breast cancer

HER2 is a well-studied tyrosine kinase (TK) membrane receptor which functions as a therapeutic target in invasive ductal breast carcinomas (IDC). The standard of care for the treatment of HER2-positive breast is the antibody trastuzumab. Despite specific treatment unfortunately, 20% of primary and 70% of metastatic HER2 tumors develop resistance. HER2 belongs to a gene family, with four members (HER1-4) and these members could be involved in resistance to anti-HER2 therapies. In this study we designed a probemix to detect the amplification of the four HER oncogenes in a single reaction. In addition, we developed a protocol based on the combination of MLPA with ddPCR to detect the tumor proportion of co-amplified HERs. On 111 IDC, the HER2 MLPA results were validated by FISH (Adjusted r ² = 0,91, p < 0,0001), CISH (Adjusted r ² = 0,938, p < 0,0001) and IHC (Adjusted r ² = 0,31, p < 0,0001). HER1-4 MLPA results were validated by RT-qPCR assays (Spearman Rank test p < 0,05). Of the 111 samples, 26% presented at least one HER amplified, of which 23% showed co-amplifications with other HERs. The percentage of cells with HER2 co-amplified varied among the tumors (from 2-72,6%). Independent in-silico findings show that the outcome of HER2+ patients is conditioned by the status of HER3 and HER4. Our results encourage further studies to investigate the relationship with patient's response to single or combined treatment. The approach could serve as proof of principle for other tumors in which the HER oncogenes are involved.

TP73 DNA methylation and upregulation of ΔNp73 are associated with an adverse prognosis in breast cancer

AIM

Accumulated evidence suggests that aberrant methylation of the TP73 gene and increased levels of ΔNp73 in primary tumours correlate with poor prognosis. However, little is known regarding the transcriptional and functional regulation of the TP73 gene in breast cancer. The aim of the present study was to determine the expression of the ΔNp73 isoform, its relationship with DNA methylation of TP73 and their clinical prognostic significance in breast cancer patients.

METHODS

TP73 gene methylation was studied in TCGA datasets and in 70 invasive ductal breast carcinomas (IDCs). The expression of p73 isoforms was evaluated by immunohistochemistry (IHC) and Western blot and correlated with clinicopathological variables and clinical outcome.

RESULTS

We observed that the methylation of diverse CpG islands of TP73 differed significantly between molecular subtypes. An inverse correlation was found between p73 protein expression and the methylation status of the TP73 gene. The expression of exon 3' of p73 (only expressed in ΔNp73) was significantly higher in patients with wild-type p53. Immunohistochemical analysis revealed that all p73 isoforms were localised in both the nuclear and cytoplasmic compartments. We confirmed a positive association between the expression of ∆Np73 and high histological grade.

CONCLUSIONS

Our findings suggest that high expression of ΔNp73 could be used to determine the aggressiveness of IDCs and could be incorporated in the pathologist's report.

Epigenetic regulation of ID4 in the determination of the BRCAness phenotype in breast cancer

BRCAness breast tumors represent a group of sporadic tumors characterized by a reduction in BRCA1 gene expression. As BRCA1 is involved in double-strand breaks (DSBs) repair, dysfunctional BRCA pathway could make a tumor sensitive to DNA damaging drugs (e.g., platinum agents). Thus, accurately identifying BRCAness could contribute to therapeutic decision making in patients harboring these tumors. The purpose of this study was to identify if BRCAness tumors present a characteristic methylation profile and/or were related to specific clinico-pathological features. BRCAness was measured by MLPA in 63 breast tumors; methylation status of 98 CpG sites within 84 cancer-related genes was analyzed by MS-MLPA. Protein and mRNA expressions of the selected genes were measured by quantitative real-time PCR and Western Blot. BRCAness was associated with younger age, higher nuclear pleomorphism, and triple-negative (TN) status. Epigenetically, we found that the strongest predictors for BRCAness tumors were the methylations of MLH1 and PAX5 plus the unmethylations of CCND2 and ID4. We determined that ID4 unmethylation correlated with the expression levels of both its mRNA and protein. We observed an inverse relation between the expressions of ID4 and BRCA1. To the best of our knowledge, this is the first report suggesting an epigenetic regulation of ID4 in BRCAness tumors. Our findings give new information of BRCAness etiology and encourage future studies on potential drug targets for BRCAness breast tumors.

DNA methylation and gene deletion analysis of brain metastases in melanoma patients identifies mutually exclusive molecular alterations

BACKGROUND

The brain is a common target of metastases for melanoma patients. Little is known about the genetic and epigenetic alterations in melanoma brain metastases (MBMs). Unraveling these molecular alterations is a key step in understanding their aggressive nature and identifying novel therapeutic targets.

METHODS

Genome-wide DNA methylation analyses of MBMs (n = 15) and normal brain tissues (n = 91) and simultaneous multigene DNA methylation and gene deletion analyses of metastatic melanoma tissues (99 MBMs and 43 extracranial metastases) were performed. BRAF and NRAS mutations were evaluated in MBMs by targeted sequencing.

RESULTS

MBMs showed significant epigenetic heterogeneity. RARB, RASSF1, ESR1, APC, PTEN, and CDH13 genes were frequently hypermethylated. Deletions were frequently detected in the CDKN2A/B locus. Of MBMs, 46.1% and 28.8% had BRAF and NRAS missense mutations, respectively. Compared with lung and liver metastases, MBMs exhibited higher frequency of CDH13 hypermethylation and CDKN2A/B locus deletion. Mutual exclusivity between hypermethylated genes and CDKN2A/B locus deletion identified 2 clinically relevant molecular subtypes of MBMs. CDKN2A/B deletions were associated with multiple MBMs and frequently hypermethylated genes with shorter time to brain metastasis.

CONCLUSIONS

Melanoma cells that colonize the brain harbor numerous genetically and epigenetically altered genes. This study presents an integrated genomic and epigenomic analysis that reveals MBM-specific molecular alterations and mutually exclusive molecular subtypes.

Healthcare quality indicators of peripheral artery disease based on systematic reviews

OBJECTIVES

Peripheral artery disease (PAD) is a major health problem whose clinical management includes multiple options regarding risk factor control, diagnosis, and medical and surgical treatment. The aim was to generate indicators based on systematic reviews to evaluate the quality of healthcare provided in PAD.

METHODS

Electronic searches were run for systematic reviews in The Cochrane Library (Issue 6, 2011), MEDLINE, EMBASE, and other databases (up to June 2011). Conclusive systematic reviews of high methodological quality were selected to formulate clinical recommendations. Indicators were derived from clinical recommendations with moderate to very high strength of evidence as assessed by the GRADE system.

RESULTS

From 1,804 reviews initially identified, 29 conclusive and high-quality systematic reviews were selected and nine clinical recommendations were formulated with a moderate to very high strength of recommendation. Six indicators were finally generated: four on pharmacological interventions, antiplatelet agents, naftidrofuryl, cilostazol, and statins; and two lifestyle interventions, exercise and tobacco cessation. No indicators were derived for diagnostic tests or surgical techniques. Most indicators targeted patients with intermittent claudication.

CONCLUSIONS

These quality indicators will help clinicians to assess the appropriateness of healthcare provided in PAD. The development of evidence-based indicators in PAD is limited by the lack of methodological quality of the research in this disease, the inconclusiveness of the evidence on diagnostic and surgical techniques, and the dynamic nature of the vascular diseases field.

Malnutrition in community-dwelling adults with dementia (NutriAlz Trial)

OBJECTIVES

The objective of this study is to assess the nutritional status, measured by the MNA, in community-dwelling elderly individuals with dementia and to identify clinical risk factors for nutritional risk or malnutrition.

DESIGN

Cross-sectional analysis of a cluster randomized clinical trial (Nutrialz).

SETTING

Community-dwelling individuals attending dementia clinics.

PARTICIPANTS

940 individuals.

MEASUREMENTS

The clinical scales assessed were Mini Nutritional Assessment (MNA), Eating Behaviour Scale (EBS), Charlson comorbidity index, Clinical Dementia Rating (CDR), Mini-Mental State Examination (MMSE), Basic Activities of Daily Living (BADL) score, Instrumental Activities of Daily Living (IADL) score, Neuropsychiatric Inventory Questionnaire (NPI-Q), Cornell depression scale and Zarit Caregiver Burden Interview.

RESULTS

5.2% of participants were classified as being malnourished, 42.6% as being at risk of malnutrition and 52.2% as well nourished. Malnutrition by type of dementia was more frequent in Lewy bodies dementia (18.2%) than in the other types. Worse nutritional status is significantly related to more advanced age and worse cognitive, functional and behavioural profile, as well as increased burden for caregivers. Presence of behavioural symptoms is significantly related to worse nutritional level for all NPI-Q symptoms but depression, exaltation, lack of inhibition and irritability. The items more strongly related to malnutrition are appetite/feeding and hallucinations. Dependence in any basic or instrumental ADL is significantly related to higher risk of malnutrition. Dependence on feeding is a strongly related risk factor, while food preparation is only a moderate one. A logistic regression model to predict at risk/malnutrition kept as significant risk factors EBS (Odds Ratio (OR) 0.84, 95%CI 0.78 to 0.91), Cornell (OR 1.12, 95%CI 1.09 to 1.16), the number of dependent BADL (OR 1.29, 95%CI 1.17 to 1.42), age (OR 1.04, 95%CI 1.02-1.06), MMSE (OR 0.95, 95%CI 0.92 to 0.98) and Charlson (OR 1.18, 95%CI 1.05 to 1.34). A similar model built for prediction of malnutrition retained as significant covariables only EBS, Cornell and the number of dependent BADL.

CONCLUSION

These results will allow a better understanding of the clinical stage previous to malnutrition. An adequate diagnosis and treatment of identified modifiable factors like functional impairment, eating behaviours and depression could delay or avoid malnutrition.

Methylation profile of triple-negative breast carcinomas

Breast cancer is a group of clinically, histopathologically and molecularly heterogeneous diseases, with different outcomes and responses to treatment. Triple-negative (TN) breast cancers are defined as tumors that lack the expression of estrogen receptor, progesterone receptor and epidermal growth factor receptor 2. This subgroup accounts for 15% of all types of breast cancer and its prevalence is higher among young African, African-American and Latino women. The hypermethylation of CpG islands (CpGI) is a common epigenetic alteration for suppressing gene expression in breast cancer and has been shown to be a key factor in breast carcinogenesis. In this study we analyzed the hypermethylation of 110 CpGI within 69 cancer-related genes in TN tumors. For the methylation analysis, we used the methyl-specific multiplex-ligation probe amplification assay. We found that the number of methylated CpGI is similar between TN and non-TN tumors, but the methylated genes between the groups are different. The methylation profile of TN tumors is defined by the methylation of five genes (that is, CDKN2B, CD44, MGMT, RB and p73) plus the non-methylation of 11 genes (that is, GSTP1, PMS2, MSH2, MLH1, MSH3, MSH6, DLC1, CACNA1A, CACNA1G, TWIST1 and ID4). We conclude that TN tumors have a specific methylation profile. Our findings give new information for better understanding tumor etiology and encourage future studies on potential drug targets for triple-negative breast tumors, which now lack a specific treatment.

Methylation profile of human breast cancer: A possible biomarker for the detection of circulating tumor cells

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Background: Genetic and epigenetic events are complementary mechanisms involved in breast carcinogenesis. One of the most common epigenetic mechanisms by which genes are silenced is the aberrant methylation of their promoter CpG islands, i.e. hypermethylation in promoters of Tumor Suppressor Genes. The identification of circulating tumor cells (CTCs) in the blood of cancer patients, based on their aberrant methylation profile, appears as a potential tool for early detection and provides therefore the promise of a non-invasive and affordable cancer detection test. Methods: The methylation status of 26 cancer-related regions was studied, using Methyl Specific-Multiplex Ligation dependent Probe Amplification (MS-MLPA) assay in invasive breast tumors (n=24), axillary lymph nodes (n= 5), and normal breast tissue (n=2). A nested-Methyl Specific PCR (Nested-MSP) was designed for one of the methylated regions in the tumor suppressor gene rassf1A, to identify CTCs in peripheral blood samples. Blood samples from non tumor individuals were used as control. Results: We observed aberrant methylation of one or more of the 26 studied gene regions in all the breast cancer samples. The profiles were specific for each tumor. The more frequently aberrant methylated genes were: rassf1A promoter (62.5%), esr1 (54.17%), apc (54.17%) and rassf1A exon 1 (50%). Absence of aberrant methylation was confirmed in normal breast tissues. The specific methylation profile of tumors could be used to identify the metastasis origin in a patient with a left-sided breast tumor and bilateral tumor invasion of axillary lymph nodes. MS-MLPA revealed identical aberrant methylation patterns in both lymph nodes, revealing a left-sided origin of the right-sided lymph node. For the detection of CTCs in blood, a Nested-MSP on rassf1A was designed. This method allowed the detection of CTCs in the peripheral blood of a cancer patient by their aberrant rassf1A methylation. A healthy age-matched control blood sample revealed absence of CTCs. Conclusions: The identification of the methylation profile of the tumor by MS-MLPA allowed to establish the metastasis origin of invaded axillary lymph nodes and to detect CTCs in peripheral blood of a cancer patient.

No significant financial relationships to disclose.

Detection of deletions and duplications in the Duchenne muscular dystrophy gene by the molecular method MLPA in the first Argentine affected families

Deletions/duplications in the Duchenne muscular dystrophy (DMD) gene account for 60 to 70% of all alterations. A new technique, multiplex ligation-dependent probe amplification (MLPA), has been described that allows the detection of large genetic rearrangements by simultaneous amplification of up to 45 target sequences. The present article is based on the diagnosis of the first Argentine affected families by the application of MLPA. DNA samples from patients with and without a previous diagnosis were included. MLPA assays were performed according to manufacturer recommendations. Polymerase chain reaction and direct sequencing were performed when a single-exon deletion was detected. Results were analyzed using the Gene Marker v1.6 and Sequencing Analysis v5.2 software. In the samples with a previous diagnosis (as identified by short tandem repeat-polymerase chain reaction analysis), MLPA confirmed in some samples the same deletion and detected in others a larger deleted fragment. This enabled the prediction of the expected male phenotype. One deletion and one duplication were detected in patients without previous diagnosis. In this study, we investigated the applicability of MLPA in our country. Our results showed a 100% confirmation of the deleted fragments detected by short tandem repeat segregation analysis. Moreover, in some cases, the MLPA assay was able to refine the breakpoints involved. In addition, MLPA identified deletions/duplications in samples without previous diagnosis. In comparison to the available diagnosis strategies in Argentina, MLPA is less time-consuming, and spans the complete coding region of DMD. The application of MLPA will improve the genetic diagnosis of DMD/Becker muscular dystrophy in our country.

Down-Regulation of Matrix Metalloproteinase-9 (MMP-9) Expression in the Myocardium of Congestive Heart Failure Patients

Matrix metalloproteinases (MMPs) are proteolytic enzymes responsible for extracellular matrix protein degradation. They have an important role in tissue remodeling processes. Their activity is regulated at the transcriptional, translational, and posttranslational level and by tissue inhibitors (TIMPs). Our aim was to analyze whether expression changes in MMPs that degrade collagens and their inhibitors in the myocardium have an impact on ventricular remodeling and the fibrogenesis in congestive heart failure.

METHODS

We analyzed left ventricle biopsies from 18 patients with idiopathic dilated cardiomyopathy (iCDM) and severe congestive heart failure (HF) and 13 biopsies from organ donors. mRNA expression was quantified by real-time PCR, and fibrosis levels measured with picrosirius red staining.

RESULTS

The patients mean age was 53 +/- 3 years. Expression levels of MMP-1, MMP-2, MMP-3, and TIMP1 did not show differences in pathological hearts compared to control hearts. Expression levels of MMP-1 and MMP-3 were low. MMP-9 expression levels were down-regulated in the cardiomyopathic hearts (49.77 +/- 7.6 ng equivalents of cDNA [ng-eq]) compared to controls (91.24 +/- 10.8 ng-eq, P < .005). MMP-2 expression levels correlated with the fibrosis levels (P < .05, R2 = 0.33, n = 18).

CONCLUSION

MMP-9 mRNA expression down-regulation suggested that the protein levels were regulated at the posttranscriptional level. The correlation between MMP-2 expression levels and the collagen fraction in the pathological hearts indicated a putative role of MMP-2 in the fibrosis that takes place in congestive heart failure.

Correlation Between Mast Cell Density and Myocardial Fibrosis in Congestive Heart Failure Patients

Besides the well-established role of mast cells in allergic reactions as an important source of vasoactive and proinflammatory products, they have been related to tissue fibrosis and remodelling processes. In a heart failure (HF) animal model, mast cells were shown to synthesize transforming growth factor beta1 and basic fibroblast growth factor in myocardial tissue and were localized to an area with fibrosis. Our objective was to quantify mast cell density in left ventricles from patients with congestive heart failure who were candidates for transplantation and to analyze whether they showed a correlation with the fibrosis level of the same area.

METHODS

We obtained myocardial biopsies from 20 patients with end-stage HF secondary to idiopathic dilated cardiomyopathy (iDCM) undergoing heart transplantation and 15 controls (donors without cardiopathy). Mast cells were detected by immunohistochemistry with a human mast cell chymase antibody and fibrosis levels measured with picrosirius red staining of collagen fibrils with later quantification by morphometry.

RESULTS

The patients mean age was 51 +/- 3 years. Fibrosis levels in the myocardial sections from patients with congestive HF was three-fold higher than those in control myocardium (12.41 +/- 1.7% vs 3.98 +/- 0.63%, P < .001). Mast cell density correlated with the collagen fraction and could be fitted to a linear regression curve: collagen fraction = 0.78 + 0.05 mast cell density (n = 33, P < .005, R2 = 0.28).

CONCLUSION

The elevated collagen fraction present in failing hearts may be the cause of increased stiffness and loss of elasticity that is detected in patients with end-stage HF. Due to the mast cells capacity to synthesize vasoactive and fibrogenic products and the correlation between their density and fibrosis levels, they probably play a role in the ventricular remodelling in HF.

Infant position in neonates receiving mechanical ventilation

BACKGROUND

Several body positions other than standard supine position have been used in patients undergoing intensive care for reducing the incidence of pressure ulcers of the skin, contractures or ankylosis and for improving the patient's well being. In patients from different age groups undergoing mechanical ventilation (MV), it has been observed that particular positions, such as prone position, may improve some respiratory parameters. Benefits from these positions have not been clearly defined in critically ill newborns who may require mechanical ventilation for extended periods of time.

OBJECTIVES

To assess the effects of different positioning of newborn infants receiving MV on short term respiratory outcomes and complications of prematurity.

SEARCH STRATEGY

Databases searched (up to May 2006) were the Oxford Database of Perinatal Trials, CINAHL, MEDLINE, EMBASE and Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 2, 2006). Hand searches of proceedings of the Society for Pediatric Research from 1990 to May 2006 were used to identify unpublished studies.

SELECTION CRITERIA

Randomised or quasi randomised clinical trials comparing different positions in newborns receiving mechanical ventilation.

DATA COLLECTION AND ANALYSIS

Three independent and unblinded reviewers assessed the trials for inclusion in the review and extracted the data. Data were double-checked and entered into the Review Manager software.

MAIN RESULTS

Eleven trials involving 206 infants were included in this review. Several positions were compared: prone vs. supine, prone vs. lateral right, lateral right vs. supine, lateral left vs. supine, lateral right vs. lateral left and good lung dependent vs. good lung uppermost. Apart from one of the two studies that compared lateral right vs. lateral left positions, and one comparing prone vs. supine position, all the included studies had a crossover design. Comparing prone vs. supine position, an increase in arterial P02 in the prone position of between 2.75 and 9.72 mm Hg (95% CI) was observed (one trial). When % hemoglobin oxygen saturation was measured with pulse oximetry, improvement in the prone position was from 1.18 to 4.36% (typical effect based on four trials). In addition, there was a slight improvement in the number of episodes of desaturation. It was not possible to establish whether this effect remained once the intervention was stopped. Negative effects from the interventions were not described, although this issue was not studied in sufficient detail. Effects of position on other outcomes were not statistically significant; however, either positive nor negative effects cannot be excluded considering the small numbers that were studied.

AUTHORS' CONCLUSIONS

The prone position was found to slightly improve the oxygenation in neonates undergoing mechanical ventilation. However, we found no evidence concerning whether particular body positions during mechanical ventilation of the neonate are effective in producing sustained and clinically relevant improvements.

Calcitonin for metastatic bone pain

BACKGROUND

Pain is the most frequent symptom experienced by cancer patients, its intensity dependent on the site of the tumour. Tumours that compromise bone or nervous structures due to the bone destruction process are the most painful. There are several treatments to deal with pain (and other symptoms) caused by bone metastases. The hormone, calcitonin, has the potential to relieve pain, and also retain bone density, thus reducing the risk of fractures. This review is an update of a previously published review in The Cochrane Library (Issue 3, 2003) on this topic.

OBJECTIVES

To assess the effectiveness of calcitonin in controlling metastatic bone pain and reducing bone complications (hypercalcemia, fractures and nerve compression) in patients with bone metastases.

SEARCH STRATEGY

Electronic searches were performed in MEDLINE (1966 to 2005), EMBASE (1974 to 2005), the Cochrane Central Register of Controlled Trials (Issue 2, 2005), specialised registers of the Cochrane Cancer Network and of the Cochrane Pain, Palliative and Supportive Care Group. Registers of clinical trials in progress were also searched.

SELECTION CRITERIA

Studies were included if they were randomised, double-blind clinical trials of patients with metastatic bone pain, treated with calcitonin, where the major outcome measure was pain, assessed at four weeks or longer.

DATA COLLECTION AND ANALYSIS

Study selection and data extraction were performed by two independent review authors. Only two studies (90 patients) were eligible for inclusion in the review and therefore meta-analysis of the data was not possible. Intention-to-treat analysis was performed by imputing all missing values as adverse outcomes.

MAIN RESULTS

Of the two small studies included in the review, one study showed a non-significant effect of calcitonin in the number of patients with total pain reduction (RR 2.50; CI 95%, 0.55 to 11.41). The second study provided no evidence that calcitonin reduced analgesia consumption (RR 1.05; CI 95%, 0.90 to 1.21) in patients with painful bone metastases. There was no evidence that calcitonin was effective in controlling complications due to bone metastases; for improving quality of life; or patients' survival. Although not statistically significant, a greater number of adverse effects were observed in the groups given calcitonin in the two included studies (RR 3.35, CI 95%, 0.72 to 15.66).

AUTHORS' CONCLUSIONS

The limited evidence currently available does not support the use of calcitonin to control pain from bone metastases. Since the last version of this review, none of the new relevant studies have provided additional information on this treatment, in contrast to other therapeutic approaches that should be considered.

[Metformin for type-2 diabetes mellitus. Systematic review and meta-analysis]

OBJECTIVE

To evaluate the efficacy of metformin against placebo, diet, oral anti-diabetics, or insulin in type 2 diabetes mellitus.

DESIGN

Systematic review.

DATA SOURCES

MEDLINE (1966-2003), EMBASE (1974-2003), LILACS (1986-2003), Cochrane library (Issue 3, 2003).

SELECTION OF STUDIES

29 randomized clinical trials of metformin in monotherapy, with results on mortality, morbidity, and biochemistry. EXTRACTION OF DATA: RevMan 4 computer program. Two reviewers extracted the data and evaluated the quality.

MAIN VARIABLES

any clinical event related to diabetes (mortality, coronary disease, stroke, arterial disease, and retinopathy). Secondary variables: weight and biochemistry.

RESULTS

29 clinical studies with 37 comparisons of metformin were analyzed (13 with sulphonylureas, 12 with placebo, 3 with diet, 3 with thiazolidinediones, 2 with alpha-glucosidase inhibitors, 2 with insulin, and 2 with meglitinides). Metformin was more beneficial than the sulphonylureas or insulin for any clinical event associated with diabetes (relative risk [RR]=0.78; 95% confidence interval [CI], 0.65-0.94) and than diet (RR=0.74; 95% CI, 0.60-0.90). Metformin decreased glycosylated hemoglobin A1 (weighted mean difference, -1.21%; 95% CI, -1.48 to -0.94), low density lipoprotein cholesterol (weighted mean difference, -0.24; 95% CI, -0.40 to -0.09), and weight (standardized mean difference, -0.11; 95% CI, -0.18 to -0.04). Metformin was more beneficial than the placebo, diet or the thiazolidinediones on glycosylated hemoglobin A1, and than the sulphonylureas or insulin on weight.

CONCLUSIONS

In the long term metformin reduces the risks of clinical events associated with diabetes. There are no long term clinical trials which compare alpha-glucosidase inhibitors, meglitinides, and thiazolidinediones with metformin, in primary results. The different treatments compared with metformin did not obtain more benefit for the secondary results evaluated.

Histological Basis of the Porcine Femoral Artery for Vascular Research

The similarities between the porcine and human cardiovascular systems make the pig a useful animal model for the study of vascular biology. However, a standardized method is needed to describe the normal histological properties of porcine arteries in order to evaluate pathologic lesions in future studies. Descriptive and morphometric analyses were done on 16 porcine femoral arteries. For these purposes, three histological stains (haematoxylin eosin, Masson's trichrome, and orcein), four immunohistochemical methods (using antibodies anti-alpha-actin, anti-CD3, anti-L1 and anti-lysozyme), and a glycohistochemical method (using Dolichos biflorus lectin) were performed. The porcine femoral arteries evaluated had a mean total area of 6.25 +/- 1.99 mm(2) and a diameter of 2.79 +/- 0.41 mm. The majority of the total area was occupied by the medial layer (42.97 +/- 5.38%) and was mainly constituted by smooth muscle cells (94.58 +/- 2.65%). All the cell markers used reacted with porcine paraffin-embedded tissue. However, the anti-lysozyme antibody was excluded from this histological analysis because of cytoplasmatic reactivity in smooth muscle cells. In summary, this study proposes histological methods to describe the normal characteristics of the porcine femoral artery and raises the possibility of applying this methodology in future studies on porcine vascular research.

Cryopreservation alters antigenicity of allografts in a porcine model of transplant vasculopathy

The need for arterial grafts in coronary surgery to complement autologous vessels has generated interest in cryopreservation of small diameter allografts. We evaluated functional and histologic changes occurring in cryopreserved allografts 3 months after porcine femoral artery transplants.

METHODS

Twenty recipient and 15 donor pigs included a control group of 16 fresh and 12 cryopreserved nonimplant arteries were used. Fresh (n=5) and cryopreserved (n=5) autografts were implanted to assess cryopreservation effects in the absence of rejection. Fresh allografts with or without treatment with cyclosporine (CsA) (n=6 of 8) and cryopreserved allografts with or without treatment with CsA (n=6 of 10) were performed to study the antigenicity of cryopreserved allografts. Arteries were stained with hematoxylin and eosin, Masson's trichrome, and orcein for morphometric analyses and immunostained to identify endothelial cells, smooth muscle cells, T lymphocytes, and macrophages.

RESULTS

Among nonimplant arteries, cryopreservation reduced alpha-actin expression and increased the luminal area. All implanted autografts were patent. Cryopreserved autografts showed reduced alpha-actin expression and developed intimal hyperplasia compared to fresh autografts. Treatment with CsA improved the patency of fresh allografts from 0% to 83% (P <.01) and of cryopreserved allografts from 40% to 100% (P <.05). Cryopreserved allografts showed substantial intimal hyperplasia, and fresh allografts had more T lymphocyte infiltration in the intimal layer with aneurysmal dilatation.

CONCLUSIONS

Cryopreservation reduces the deposition of inflammatory cells and prevents the thrombosis or aneurysmal lesions observed in fresh allografts. Therefore, cryopreservation modifies the antigenicity of vascular allografts.

Enalaprilat, losartan and LU 135252 in coronary blood flow regulation

BACKGROUND

High plasma levels of angiotensin II are found in several pathologies such as hypertension, heart failure and myocardial infarction. The effect of high concentrations of angiotensin II on coronary circulation is not well defined. The aim of the present study was to assess coronary blood flow regulation during tachycardia in the presence of elevated coronary plasma levels of angiotensin II, and the changes induced by ACE inhibition and blockade of angiotensin II and endothelin-A receptors.

DESIGN

Left anterior coronary artery was catheterized in 38 pigs to infuse the study drugs. Saline was infused for 15 min. Then, the first atrial pacing was performed. The pigs were distributed to: Group 1 (n = 7) angiotensin II; Group 2 (n = 7) enalaprilat + angiotensin II; Group 3 (n = 9) the bradykinin B2 antagonist HOE 140 + enalaprilat + angiotensin II; Group 4 (n = 7) losartan + angiotensin II; and Group 5 (n = 8) endothelin-A receptor antagonist LU 135252 + angiotensin II. After giving these infusions, a second pacing was repeated.

RESULTS

The increase in coronary blood flow induced by pacing with angiotensin II was reduced from 181 +/- 21% to 116 +/- 37% (P = 0.006 vs. saline). Enalaprilat, losartan and LU 135252 restored the capacity of coronary blood flow to increase during pacing (151 +/- 39%, 162 +/- 35% and 161 +/- 16%, respectively; P = NS, vs. saline), while HOE 140 abolished the effect of enalaprilat.

CONCLUSIONS

Moderately elevated coronary concentrations of angiotensin II reduced coronary blood flow during pacing. Enalaprilat, losartan and LU 135252 restored the hyperaemic coronary flow to similar values observed with saline. The beneficial effect of ACE inhibition is mediated through an increase in bradykinin.

Infant position in neonates receiving mechanical ventilation

BACKGROUND

Several body positions other than standard supine position have been used in patients undergoing intensive care for reducing the incidence of pressure ulcers of the skin, contractures or ankylosis and for improving the patient's well being. In patients from different age groups undergoing mechanical ventilation (MV), it has been observed that particular positions such as prone position may improve some respiratory parameters. Benefits from these positions have not been clearly defined in Neonatology, a field where it is common that patients require mechanical ventilation sometimes during extended time periods.

OBJECTIVES

To assess the effects on both short and long-term outcomes of different positioning of newborn infants receiving MV.

SEARCH STRATEGY

Databases searched (up to January 2002) were the Oxford Database of Perinatal Trials, CINAHL, MEDLINE, EMBASE and Cochrane Controlled Trials Register (The Cochrane Library, Issue 1, 2002). Hand searches of proceedings of the Society for Pediatric Research from 1990 to January 2002 were used to identify unpublished studies.

SELECTION CRITERIA

Randomised or quasi randomised clinical trials comparing different positions in newborns receiving mechanical ventilation.

DATA COLLECTION AND ANALYSIS

Three independent and unblinded reviewers assessed the trials for inclusion in the review and extracted the data. Data were double-checked and entered into the Review Manager software.

MAIN RESULTS

Ten trials involving 164 infants were included in this review. Several positions were compared: prone vs. supine, prone vs. lateral right, lateral right vs. supine, lateral left vs. supine, lateral right vs. lateral left and good lung dependent vs. good lung uppermost. Apart from one of the two studies that compared lateral right vs. lateral left positions, all the included studies had a crossover design. Comparing prone vs. supine position, an increase in arterial P02 in the prone position of between 2.75 and 9.72 mm Hg (95%CI) was observed (one trial). When % hemoglobin oxygen saturation was measured with pulse oximetry, improvement in the prone position was from 1.17 to 4.36% (typical effect based on four trials). It was not possible to establish whether this effect remained once the intervention was stopped. Negative effects from the interventions were not described, although this issue was not studied enough. Effects of position on other outcomes were not statistically significant; however, these cannot be excluded considering the small numbers that were studied.

REVIEWER'S CONCLUSIONS

The prone position was found to slightly improve the oxygenation in neonates undergoing mechanical ventilation. However, we found no evidence concerning whether particular body positions during mechanical ventilation of the neonate are effective in producing sustained and clinically relevant improvements.

Radioisotopes for metastatic bone pain

BACKGROUND

Bone metastases manifest through pain, which can arise even before the injury is radiologically detected. Pain occurs as a result of bone destruction and, as more destruction ensues, more pain can be experienced. Radiculopathies, plexopathies and shrinkage of spinal nerves due to tumour growth and fractures are very frequent in these patients. Relief of pain from bone metastasis can be achieved by treating the cancer itself; radiotherapy; conventional analgesics; and specific drugs that work on the bone tumour-induced alteration: biphosphonates, calcitonin or radioactive agents.

OBJECTIVES

To determine the efficacy of radioisotopes to control metastatic pain in patients with bone metastases and complications due to bone metastases (hypercalcaemia, bone fracture and spinal cord compression) as well as its efficacy in terms of patient survival and adverse effects.

SEARCH STRATEGY

Randomised and controlled clinical trials related to this review were retrieved electronically using MEDLINE (1966-2003), EMBASE (1974-2003) and Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 1 2003). general strategies to identify RCTs were combined with specific commands to identify trials of radioisotopes and metastatic bone pain.

SELECTION CRITERIA

The inclusion criteria were: randomised trials of patients with metastatic bone pain that compared treatment with radioisotopes and placebo, and where the major outcome was either pain or complications of bone metastases (eg, hypercalcaemia, bone fracture, spinal cord compression) assessed at least four weeks after treatment.

DATA COLLECTION AND ANALYSIS

The quality of included studies was assessed using the Jadad scale and the Oxford Pain Validity Score. Two independent reviewers extracted the data and completed a standard form designed for that purpose. An intention-to-treat analysis was performed, and global estimates of effect were calculated using a random effects model.

MAIN RESULTS

Four trials (325 patients) provided data that suggest a small effect of radioisotopes on pain control both at short and medium term (one to six months). No evidence was available to assess long-term effects (12 months). Only one study provided data on analgesia use and concluded that patients given either radioisotopes or placebo showed similar levels of analgesic use when compared to baseline use. Leukocytopenia and thrombocytopenia are secondary effects associated with the administration of radioisotopes. The incidence of leukocytopenia is significantly greater in patients treated with radioisotopes (RR=4.56, 95% CI (1.22,17.08)). There were also a greater number of thrombocytopenia events in the treatment group, without reaching statistical significance.

REVIEWER'S CONCLUSIONS

The efficacy of radioisotopes has been assessed in clinical trials with small sample sizes and short-term evaluations of the outcomes. There is some evidence indicating that radioisotopes may give complete reduction in pain over one to six months with no increase in analgesic use, but adverse effects, specifically leukocytopenia and thrombocytopenia, have also been experienced.

Calcitonin for metastatic bone pain

BACKGROUND

Pain is the most frequent symptom experienced by cancer patients, its intensity dependent on the site of the tumour. Tumours that compromise bone or nervous structures due to the bone destruction process are the most painful. There are several treatments to deal with pain (and other symptoms) caused by bone metastasis. The hormone, calcitonin, has the potential to relieve pain, and also retain bone density, thus reducing the risk of fractures.

OBJECTIVES

To assess the effectiveness of calcitonin in controlling metastatic bone pain and reducing bone complications (hypercalcemia, fractures and nervous compression) in patients with bone metastases.

SEARCH STRATEGY

Electronic searches were performed in MEDLINE (1966-2001), EMBASE (1974-2001), the Cochrane Central Register of Controlled Trials (Issue 2, 2001), specialised registers of the Cochrane Cancer Network and of the Cochrane Pain, Palliative and Supportive Care Group. Registers of clinical trials in progress were also searched.

SELECTION CRITERIA

Studies were included if they were randomised, double-blind clinical trials of patients with metastatic bone pain, treated with calcitonin, where the major outcome measure was pain, assessed at four weeks or longer.

DATA COLLECTION AND ANALYSIS

Study selection and data extraction were performed by two independent reviewers. Only two studies (90 patients) were eligible for inclusion in the review and therefore meta-analysis of the data was not possible. Intention-to-treat analysis was performed by imputing all missing values as adverse outcomes.

MAIN RESULTS

Of the two small studies included in the review, one study showed a non-significant effect of calcitonin in the number of patients with total pain reduction (RR 2.50; CI 95%, 0.55 to 11.41). The second study provided no evidence that calcitonin reduced analgesia consumption (RR 1.05; CI 95%, 0.90 to 1.21) in patients with painful bone metastases. There was no evidence that calcitonin was effective in controlling complications due to bone metastases; for improving quality of life; or patients' survival. Although not statistically significant, a greater number of adverse effects were observed in the groups given calcitonin in the two included studies (RR 3.35, CI 95%, 0.72 to 15.66).

REVIEWER'S CONCLUSIONS

The limited evidence currently available for systematic review does not support the use of calcitonin to control pain from bone metastases. Until new studies provide additional information on this treatment, other therapeutic approaches should be considered.

Helicobacter pylori does not play a part in the dyspeptic complaints of rheumatology patients receiving long term treatment with non-steroidal anti-inflammatory drugs

BACKGROUND

The presence of dyspeptic symptoms is a common finding in patients treated with non-steroidal anti-inflammatory drugs (NSAIDs). Some studies seem to support the involvement of Helicobacter pylori infection in the dyspeptic symptoms reported by these patients, and suggest that eradication may be useful.

OBJECTIVE

To determine the variables related to dyspepsia in rheumatology patients requiring NSAID treatment, assessing in particular the role of Helicobacter pylori infection.

METHODS

One hundred and eighty six consecutive patients with a rheumatological disorder requiring NSAID treatment (68 male, 118 female; mean (SD) age 55 (15) years) were included in a cross sectional study; dyspeptic symptoms were measured by a previously validated scale. Helicobacter pylori infection was determined by serology. Variables related to the severity of symptoms and the need for antisecretory drugs were determined by multivariate analysis.

RESULTS

No relation was found between Helicobacter pylori infection and dyspepsia or any of its surrogate markers (antisecretory drug use or NSAID intolerance). Female sex and treatment with antisecretory drugs were found to be independent predictors for the appearance and severity of dyspeptic symptoms. The only independent predictive variables of the requirement for antisecretory drugs were age, previous ulcer disease, taking NSAIDs with a medium or high anti-inflammatory potential, and the symptoms score.

CONCLUSION

Helicobacter pylori infection does not seem to play any part in the gastric symptoms of patients treated long term with NSAIDs.

[Prevalence of hypovitaminosis D in elderly institutionalized residents: influence of a substitutive treatment]

BACKGROUND

Osteoporosis in the elderly is a common and severe disease, vitamin D deficiency being an important causative factor. Hypovitaminosis D is frequent in old people, particularly those living in nursing homes.

SUBJECTS AND METHOD

We performed a cross-sectional study of 100 randomly recruited elderly institutionalized subjects. The prevalence of hypovitaminosis D and its possible repercussion on the phosphocalcium metabolism were assessed. The degree of sun exposure and the existence of co-morbidity were also recorded. Individuals with hypovitaminosis D were included in a longitudinal study (6 months' duration) aimed at assess the efficacy of treatment with calcium and two different therapeutic regimens with calcidiol (16,000 IU/week or 16,000 IU every 3 weeks).

RESULTS

87% of individuals had hypovitaminosis D; 21.8% of them had secondary hyperparathyroidism. The study population had a low degree of sun exposure and a high level of co-morbidity. The two doses of calcidiol led to a normalization of 25-OHD3 levels, increased calciuria and compensated secondary hyperparathyroidism, yet higher 25-OHD3 levels were achieved with the weekly therapeutic scheme.

CONCLUSIONS

Hypovitaminosis D prevalence appears to be very high In the elderly institutionalized population. Calcium and calcidiol supplementation normalized 25-OHD3, improved calcium absorption and compensated secondary hyperparathyroidism. Calcium and vitamin D supplementation should be employed routinely in the elderly institutionalized population.

Acute and mid-term combined hormone replacement therapy improves endothelial function in post-menopausal women with angina and angiographically normal coronary arteries

AIMS AND BACKGROUND

Coronary endothelial dysfunction improves after acute oestradiol treatment in women with angina and normal coronary angiograms. We sought to analyse whether this effect is also seen in the peripheral circulation and whether it is sustained after a mid-term period of treatment.

METHODS

We studied 20 women with angina, signs suggestive of myocardial ischaemia and normal coronary angiograms. In five of them, coronary and peripheral endothelial functions were studied at baseline. Brachial artery flow-mediated dilation was reanalysed after 24 h of transdermal oestradiol treatment. In the other 15 women, brachial artery vasoreactivity was studied at baseline and after a 6-week period of treatment with transdermal oestradiol and medroxyprogesterone (HRT) or placebo in a double-blinded crossover fashion.

RESULTS

An abnormal coronary artery response to acetylcholine was observed in all women as well as impaired brachial flow-mediated dilation. Brachial flow-mediated dilation significantly increased after 24 h of oestradiol treatment (4.8+/-0.8% vs 0.06+/-0.6%, P<0.001). Peripheral flow-mediated dilation also increased after a 6-week period of HRT compared with baseline (4.1+/-3% vs 0.4+/-1%, P<0.01) and placebo treatment (4.1+/-3% vs 0.6+/-1.7%, P<0.01).

CONCLUSION

Impaired endothelium-dependent vasodilation exists both at the coronary and peripheral circulation in post-menopausal women with angina and normal coronary angiograms. Flow-mediated dilation improves in these women after short and mid-term therapy with transdermal oestradiol irrespective of concomitant progesterone use.

[Probabilistic models of mortality for patients hospitalized in conventional units]

BACKGROUND

We have developed a tool to measure disease severity of patients hospitalized in conventional units in order to evaluate and compare the effectiveness and quality of health care in our setting.

PATIENTS AND METHOD

A total of 2,274 adult patients admitted consecutively to inpatient units from the Medicine, Surgery and Orthopaedic Surgery, and Trauma Departments of the Corporació Sanitària Parc Taulí of Sabadell, Spain, between November 1, 1997 and September 30, 1998 were included. The following variables were collected: demographic data, previous health state, substance abuse, comorbidity prior to admission, characteristics of the admission, clinical parameters within the first 24 hours of admission, laboratory results and data from the Basic Minimum Data Set of hospital discharges. Multiple logistic regression analysis was used to develop mortality probability models during the hospital stay.

RESULTS

The mortality probability model at admission (MPMHOS-0) contained 7 variables associated with mortality during hospital stay: age, urgent admission, chronic cardiac insufficiency, chronic respiratory insufficiency, chronic liver disease, neoplasm, and dementia syndrome. The mortality probability model at 24-48 hours from admission (MPMHOS-24) contained 9 variables: those included in the MPMHOS-0 plus two statistically significant laboratory variables: hemoglobin and creatinine.

CONCLUSIONS

Severity measures, in particular those presented in this study, can be helpful for the interpretation of hospital mortality rates and can guide mortality or quality committees at the time of investigating health care-related problems.

Population screening of F508del (DeltaF508), the most frequent mutation in the CFTR gene associated with cystic fibrosis in Argentina

Cystic fibrosis (CF) is the most common autosomal recessive disease in the Caucasian population. The disease can be caused by one of the more than 900 different mutations in the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) gene. However, the deletion of the phe508-codon is the most prevalent mutation observed. Our aim was to perform a screening for this mutation (DeltaF508, or F508del) in the population of Mendoza, Argentina. For the screening, 1,000 blood samples were obtained from CF asymptomatic individuals and combined into 100 pools each containing 10 different blood samples. Pools containing at least one F508del carrier were detected by heteroduplex formation during the PCR amplification of exon 10. The PCR was designed to introduce a recognition site for a restriction enzyme that confirmed the presence of the deletion F508del in the positive pools. The results with this simple method indicate a frequency of carriers in the Mendoza population of 2.1% (1.3%-3.2, 95% confidence limits). The observed frequency of carriers is similar to that reported for European populations. Hum Mutat 18:167, 2001.

[Estradiol enhances endothelium-dependent vasodilation via a nitric oxide pathway]

BACKGROUND AND AIM

The mechanisms by which estradiol dilates arterial vessels are still unclear. Our aim was to study if estradiol enhances endothelium-dependent vasodilation in an experimental model of human arteries in vitro, and if this effect is nitric oxide mediated.

METHODS

Using organ bath chambers, we studied 18 arterial rings obtained from left internal mammary arteries during coronary artery bypass grafting surgery. Response to acetylcholine was evaluated at baseline and after the addition of estradiol 10-6 mol/l to the medium, both in the presence or absence of a nitric oxide synthase inhibitor (L-NNA 10-4 mol/l).

RESULTS

Estradiol significantly enhanced the relaxation of the arterial rings in response to acetylcholine (52 +/- 20% after estradiol versus 42 +/- 22% at baseline; n = 10; p = 0.02). However, endothelium-dependent vasodilation relaxation after estradiol addition was not enhanced in the presence of L-NNA (47 +/- 25% after estradiol versus 38 +/- 22% at baseline; n = 8; p = NS).

CONCLUSIONS

Estradiol in vitro enhances endothelium-dependent vasodilation of internal human mammary artery rings; this effect is blunted after the addition to the medium of a nitric oxide inhibitor. Therefore, the vasodilator properties of estradiol at the studied dosage depend on the nitric oxide pathway.

Proton pump inhibitors versus H2-antagonists: a meta-analysis of their efficacy in treating bleeding peptic ulcer

PURPOSE

To evaluate whether proton pump inhibitors are more effective than H2-antagonists (H2-A) for the treatment of bleeding peptic ulcer.

DATA SOURCES

PubMed database until January 2000.

STUDY SELECTION

Comparative randomized trials of proton pump inhibitors (omeprazole, lansoprazole, or pantoprazole) vs. H2-A (cimetidine, ranitidine or famotidine).

DATA EXTRACTION

Meta-analysis combining the odds ratios (OR) of the individual studies in a global OR (Peto method). OUTCOMES EVALUATED: Persistent or recurrent bleeding, need for surgery, or mortality.

DATA SYNTHESIS

Eleven studies fulfilled the inclusion criteria and contained data for at least one of the planned comparisons. Persistent or recurrent bleeding was reported in 6.7% (95% CI: 4.9-8.6%) of the patients treated with proton pump inhibitors, and in 13.4% (95% CI: 10.8-16%) of those treated with H2-A (OR 0.4; 95% CI: 0.27-0.59) (chi2-homogeneity test, 18; P=0.09). Surgery was needed in 5.2% (95% CI: 3.4-6.9%) of the patients treated with proton pump inhibitors, and in 6.9% (95% CI: 4.9-8.9%) of the patients treated with H2-A (OR 0.7; 95% CI: 0.43-1.13). Respective percentages for mortality were 1.6% (95% CI: 0.9-2.9%) and 2.2% (95% CI: 1.3-3.7%) (OR 0.69; 95% CI: 0.31-1.57). SUB-ANALYSIS: Five studies evaluated the effect of both therapies given in bolus injections on persistent or recurrent bleeding rate, which was 6% (95% CI: 3.6-8.3%) and 8.1% (95% CI: 5.3-10.9%), respectively (OR, 0.57; 95% CI: 0.31-1.05). Persistent or recurrent bleeding in high risk patients (Forrest Ia, Ib and IIa) occurred in 13.2% (95% CI: 7.9-8%) of the patients treated with proton pump inhibitors and in 34.5% (27-42%) of those treated with H2-A (OR 0.28; 95% CI: 0.16-0.48). In patients not having endoscopic therapy, persistent or recurrent bleeding was reported, respectively, in 4.3% (95% CI: 2.7-6.7%) and in 12% (95% CI: 8.7-15%) (OR 0.24; 95% CI: 0.13-0.43). Less marked differences were observed in patients having adjunct endoscopic therapy: 10.3% (95% CI: 6.7-13.8%) and 15.2% (11.1-19.3%) (OR 0.59; 95% CI: 0.36-0.97). Moreover, the significance disappeared in this group when a single outlier study was excluded.

CONCLUSIONS

Proton pump inhibitors are more effective than H2-A in preventing persistent or recurrent bleeding from peptic ulcer, although this advantage seems to be more evident in patients not having adjunct sclerosis therapy. This beneficial effect seems to be similar or even more marked in patients with Forrest Ia, Ib or IIa ulcers. However, proton pump inhibitors are not more effective than H2-A for reducing surgery or mortality rates. Nevertheless, the data are too scarce and heterogeneous to draw definitive conclusions, and further comparative trials are clearly warranted.

Effect of p27 deficiency and rapamycin on intimal hyperplasia: in vivo and in vitro studies using a p27 knockout mouse model

SUMMARY

Rapamycin, an immunosuppressant and antiproliferative agent, reduces intimal hyperplasia after arterial injury in animal models and in a preliminary study in humans. Rapamycin treatment reportedly increases expression of p27, a cyclin-dependent kinase inhibitor. This mechanism was tested using a p27-deficient (p27 -/-) murine model. Aortic smooth muscle cells from wild-type (WT) and p27 -/- mice were isolated and cultured. Cell proliferation, assessed by cell count and (3)H-thymidine incorporation, was inhibited significantly by rapamycin in WT and p27 -/- cells at concentrations of 1 ng/ml, 10 ng/ml, and 100 ng/ml (p < 0.05, versus control). The in vivo effect on intimal hyperplasia was studied in p27 -/- and WT mice after femoral artery transluminal injury. Rapamycin treatment was started 2 days before injury and maintained for 2 weeks (1 mg/kg per 48 hours, ip). No significant differences in intima-to-media ratio were found between WT (1.1 +/- 0.1) and p27 -/- mice (1.0 +/- 0.1) 4 weeks after injury. Rapamycin significantly (p < 0.05) reduced intima-to-media ratios in both WT (0.7 +/- 0.1) and p27 -/- mice (0.5 +/- 0.1), compared with untreated mice. p27 deficiency did not alter the arterial wall proliferative response to injury. The inhibitory effect of rapamycin on intimal hyperplasia occurred via a p27-independent mechanism. The in vitro data showed that this effect was mediated through decreased proliferation and enhanced apoptosis.

Helicobacter pylori is not a risk factor for hepatic encephalopathy

BACKGROUND

Helicobacter pylori infection has been described as a risk factor for hepatic encephalopathy in patients with chronic liver disease although the topic remains controversial.

AIMS

To determine whether Helicobacter pylori infection is an independent predictive factor for encephalopathy in patients with liver cirrhosis.

METHODS

Clinical, epidemiological, analytical and nutritional parameters of 205 patients were collected. Helicobacter pylori infection was determined by serology. Encephalopathy (grade II or higher) was clinically assessed during follow-up. The relationship between each parameter and encephalopathy was analysed by Kaplan-Meier curves and the Log rank test. The most significant parameters underwent multivariate analysis by Cox regression.

RESULTS

Twenty-five variables were related to encephalopathy in the bivariate analysis. Multivariate analysis selected five independent factors: previous bouts of encephalopathy (Odds ratio 3.79; 95% confidence interval 1.94-7.38), albumin (Odds ratio 0.86; 95% confidence interval 0.80-0.92), tricipital skin fold (Odds ratio 0.79; 95% confidence interval 0.66-0.95) chronic pulmonary disease (Odds ratio 2.78, 95% confidence interval; 1.31-5.92), and on-going alcoholism (Odds ratio 2.62; 95% confidence interval 1.16-5. BB).

CONCLUSIONS

Helicobacter pylori is not an independent risk factor for hepatic encephalopathy.

Bladder cancer in the textile industry

OBJECTIVES

This study examined the occupations and industries at high risk for bladder cancer in an area where the textile industry is plentiful and the incidence of the disease is very high.

METHODS

A case-referent study concerning 218 incident bladder cancer cases diagnosed during 1993-1995 in the county of Vallès Occidental, Barcelona, was carried out. A reference group (N=344) was selected from municipal lists matched to the cases by age, gender, and area of residence. All the subjects were personally interviewed, and a complete occupational history was abstracted together with other sociodemographic and life-style factors. All odds ratios (OR) and 95% confidence intervals (95% CI) were adjusted for age, gender, and smoking.

RESULTS

No overall excess risk was found forever having worked in the textile industry (OR 1.13, 95% CI 0.79-1.63) nor for specific sectors of this industry (ie cotton, wool, silk). An excess risk was observed for spinners and winders employed for more than 20 years (OR 3.28, 95% CI 1.08-9.97) and for machine setters employed between 1960 and 1974 (OR 4.26, 95% CI 1.09-16.7).

CONCLUSIONS

The results of this study do not support the findings of some earlier studies for an increased bladder cancer risk in the textile industry. However, some elevated risks were observed among the workers with the highest exposures.

Inhibition of tissue factor reduces thrombus formation and intimal hyperplasia after porcine coronary angioplasty

OBJECTIVES

We investigated the in vivo effects of tissue factor (TF) inhibition with recombinant tissue factor pathway inhibitor (rTFPI) on acute thrombus formation and intimal hyperplasia and the in vitro effects on smooth muscle cell migration and proliferation.

BACKGROUND

Inhibition of TF with TFPI has been shown to reduce intimal hyperplasia in experimental models. However, its effects after coronary angioplasty and the cellular mechanisms involved have not been investigated.

METHODS

Twenty-three swine underwent multivessel coronary angioplasty. Fifteen (n = 25 arteries) were euthanized at 72 h to assess thrombus formation and eight (n = 24 arteries) at 28 days to assess intimal hyperplasia. Animals in the 72-h time point received: 1) human rTFPI (0.5 mg bolus plus 25 microg/kg/min continuous infusion for 3 days) plus heparin (150 IU/kg intravenous bolus) plus acetyl salicylic acid (ASA) (325 mg/day); 2) rTFPI regimen plus ASA and 3) heparin (150 IU/kg intravenous bolus) plus ASA.

RESULTS

On histology the control group had evidence of mural thrombus (area 0.8+/-0.4 mm2). Treatment with TFPI plus heparin abolished thrombus formation (mean area: 0.0+/-0.0 mm2, p < 0.05) but was associated with prolonged activated partial thromboplastin time and extravascular hemorrhage. Recombinant TFPI alone inhibited thrombosis without bleeding complications (mean area: 0.03+/-0.02 mm2, p < 0.05 vs. control). Animals in the 28-day time point received continuous intravenous infusion of rTFPI or control solution for 14 days. Tissue factor pathway inhibitor reduced neointimal formation with mean intimal area of 1.2+/-0.3 mm2 versus 3.2+/-0.4 mm2 in the control group; p < 0.01. Recombinant TFPI had no effect on human aortic smooth muscle cell growth but inhibited platelet-derived growth factor BB-induced migration.

CONCLUSIONS

Inhibition of TF with rTFPI can prevent acute thrombosis and intimal hyperplasia after injury. Tissue factor plasma inhibitor may prove useful as an adjunct to intracoronary interventions.

Apoptosis, proliferation, and p27 expression during vessel wall healing: time course study in a mouse model of transluminal femoral artery injury

OBJECTIVE

The balance between cell death and proliferation in the vessel wall influences neointimal formation, remodeling, and eventual luminal narrowing after arterial injury. In this study, the time course of apoptosis, proliferation, and expression of p27-a critical regulator of cell-cycle progression-is characterized in a mouse model of transluminal arterial injury associated with substantial neointimal formation.

METHODS

C57BL/6 mice underwent bilateral femoral artery injury by passage of an angioplasty guidewire. Expression of p27, Ki67 proliferative index, and apoptosis, as well as histomorphometry, were analyzed in cross sections of uninjured arteries and arteries harvested at different time intervals after injury.

RESULTS

In the uninjured arteries, no apoptotic cells were detected, and p27 and Ki67 were expressed in less than 5% of medial cells. After injury, apoptosis increased markedly in medial smooth muscle cells from 1 to 24 hours and decreased gradually thereafter. Ki67 proliferative index increased after 1 week, peaked at 2 weeks in both the media and neointima, and decreased thereafter. p27 expression was undetectable from 1 to 48 hours, and increased gradually from 1 to 4 weeks. Well-developed neointima was present at 2 and 4 weeks.

CONCLUSIONS

In vivo injury to the mouse femoral artery evokes a rapid apoptotic response and downregulation of p27, followed by gradual increase in proliferation. During later phases of arterial repair, p27 expression increases while a shift of proliferation rates toward baseline occurs. Future experiments using this model in genetically modified mice may help identify specific cell-cycle regulatory molecules as therapeutic targets for control of pathologic arterial healing.

[Prospective assessment of clinical outcomes in patients with lung cancer]

BACKGROUND

The aim of this study was to assess the outcome in patients with lung cancer.

PATIENTS AND METHODS

Prospective study in 93 patients with lung cancer in 3 community hospitals. In each evaluation (4-6 weeks) the following results were obtained: a) questionnaire on the quality of life or performance status (QoL/PS), based on different instruments (Karnofsky Performance Scale [KPS], ECOG, QLQ-C30, and the Nottingham Health Profile [NHP], and b) a clinical questionnaire. Active follow-up was for 18 months and survival tracking was to five years. A descriptive analysis of the outcome variables and a survival analysis (Kaplan-Meier) were done. The prognostic value of each instrument (Cox) and the correlation between the instruments (Spearman) were also evaluated.

RESULTS

The mean values recorded at the time of diagnosis between 60% and 70% of the maximum value possible. Mean survival was 12.4 months; accumulated survival was 30% to one year and 4% to 55 months. Only 17% of patients presented any disease-free period. Toxicity of treatment was almost always irrelevant. The correlation between the KPS, the QLQ-30 and the NHP was acceptable and their initial values were important prognostic factors. The QoL/PS scores for the survivors were similar to their initial values, but the global values were 11%.

CONCLUSIONS

The outcomes measures used in this study provide very useful information, although registration and analysis of the necessary data should be systematic. The KPS was comparable to the other QoL/PS indicators used, but it is shorter, more acceptable and easier to use. Better QoL/PS measurement instruments are needed to evaluate outcomes in the practice of clinical oncology.

Proton pump inhibitor, clarithromycin and either amoxycillin or nitroimidazole: a meta-analysis of eradication of Helicobacter pylori

AIM

To perform a meta-analysis of studies comparing twice daily, one-week triple therapy with a proton pump inhibitor, clarithromycin (C) and amoxycillin (A) (PCA) vs. those using proton pump inhibitor, clarithromycin and a nitroimidazole (N) (PCN) for H. pylori eradication.

REVIEW METHODS

SELECTION CRITERIA

Comparative randomized trials of PCA vs. PCN were included.

DATA SOURCES

PubMed database and abstracts from congresses until September 1999.

STATISTICS

Meta-analysis was performed combining the Odds Ratios (OR) of the individual studies in a global OR (Peto method) both on an intention-to-treat (ITT) and on a per protocol (PP) basis.

RESULTS

Twenty-two studies fulfilled the inclusion criteria. Eighteen studies reported ITT and 20 PP analysis. Mean H. pylori eradication rates were 81% (95% CI: 79-83%) ITT, and 84% (82-86%) PP with PCA, and 81% (78-83%) ITT and 84% (82-86%) PP with PCN; the odds ratio for the effect of PCA vs. PCN was 1 (0.83-1.22) on an ITT, and 0.98 (0.8-1.2) on a PP basis. Subanalysis showed that mean H. pylori eradication efficacy with PC(250 b.d.)A was 81% (78-85%) ITT, vs. 86% (83-89%) with PC(250 b.d.)N. The odds ratio for this comparison was 0.68 (0.48-0.98). Finally, when comparing PC(500 b.d. )A against PC(250 b.d.)N ITT cure rates were 77% (74-80%), and 75% (72-78%) with an odds ratio of 1.18 (0.93-1.5).

CONCLUSION

Overall, one-week combination regimens of PCA and PCN present similar H. pylori eradication efficacy. Nevertheless, the PCN regimen obtains significantly better results when using low doses of C (250 mg b.d.).

[Diagnosis by directed mutagenesis of a mutation at the hMSH2 gene associated with hereditary nonpolyposis colorectal cancer]

Hereditary nonpolyposis colorectal cancer (NHPCC) is the most common form of inherited colon cancer and one of the most frequent autosomal dominant disorders. HNPCC presents an early onset of colorectal cancer (< 50 years), proximal localization of the colonic tumors, and high risk of developing multiple primary colorectal tumors as well as extracolonic tumors. This disease is caused by mutations in at least four DNA mismatch repair genes, (hMSH2, hMLH1, hPMS1 and hPMS2) and estimations indicate that it affects 1:200-1:2,000 people in the Western populations. The identification of the genes responsible for HNPCC has prompted the search for mutations in affected individuals. DNA from an affected member of a family was sent to a Dutch HNPCC Diagnosis Centre. This Centre reported a germinal mutation, which introduces a premature stopcodon and causes the production of a truncated protein. This particular mutation has not been previously registered in the database of mutations related to this disease. After the identification of the mutation in the index patient, we have developed a quick and efficient procedure for detecting mutations in the rest of the family. The methodology is based on the amplification of the exon 13 in the hMSH2 gene using a forward primer that abuts the mutation site and introduces the cutting sequence of the enzyme Haelll++ only in the wild type allele. At present, seventeen members of the family have been diagnosed and nine have been found to be affected. The methodology is simple, specific, sensitive, inexpensive and applicable in low complexity laboratories.

Helicobacter pylori eradication: proton pump inhibitor vs. ranitidine bismuth citrate plus two antibiotics for 1 week-a meta-analysis of efficacy

OBJECTIVE

To compare the efficacy of proton pump inhibitor vs. ranitidine bismuth citrate (RBC) with two antibiotics for 1 week in Helicobacter pylori eradication.

METHODS

Randomized trials comparing 1-week regimens with (i) proton pump inhibitor plus two antibiotics [clarithromycin (C) and amoxycillin (A) or a nitroimidazole (N)]; or (ii) RBC plus the same antibiotics. Eradication was confirmed by histology or 13C-urea breath test at least 4 weeks after therapy. Data sources included PubMed database and abstracts from congresses until October 1999. Statistical analysis was by meta-analysis combining the odds ratios (OR) of the individual studies in a global OR (Peto method).

RESULTS

Twelve studies met the selection criteria. Nine compared proton pump inhibitor vs. RBC plus C and A, and five compared proton pump inhibitor vs. RBC plus C and N. With RBC, C and A, mean H. pylori eradication efficacy by intention-to-treat analysis (pooled data) was 76.6% (95% CI: 72-81%) and 73.7% (95% CI: 69-78%) with proton pump inhibitor, C and A. The OR for the effect of RBC vs. proton pump inhibitor (plus C and A) on H. pylori eradication was 1.15 (95% CI: 0.8-1.64%). Mean H. pylori eradication with RBC, C and N was 87. 2% (95% CI: 83-91%), and 74.9% (95% CI: 74-84%) with proton pump inhibitor plus these two antibiotics. The OR for the effect of RBC vs. proton pump inhibitor (plus C and N) on H. pylori eradication was 1.76 (95% CI: 1.08-2.85%).

CONCLUSION

RBC and proton pump inhibitor have similar efficacy for H. pylori eradication when given with C and A for 1 week, but RBC seems to have a higher efficacy than proton pump inhibitor when C and N are the co-prescribed antibiotics.

Validation of phone interview for follow-up in clinical trials on dyspepsia: evaluation of the Glasgow Dyspepsia Severity Score and a Likert-scale symptoms test

OBJECTIVE

To validate two widely used dyspepsia scores performed by phone interview.

DESIGN

Spanish translations of the Glasgow Dyspepsia Severity Score and a Likert-scale symptomatic test were evaluated. Responsiveness to the treatment, validity of the tests, and reproducibility of tests performed by phone interview were assessed.

SETTING

Gastroenterology and endoscopy unit of a county hospital.

PARTICIPANTS

Group I consisted of 16 ulcer patients undergoing Helicobacter pylori eradication; Group II consisted of 29 healthy volunteers; and Group III consisted of 95 patients undergoing upper endoscopy.

MEASUREMENTS

Glasgow Severity Dyspepsia Score and Likert test.

RESULTS

Both tests showed adequate improvement (responsiveness) after H. pylori eradication. With regard to validity, the Glasgow and Likert test were significantly higher in 95 patients undergoing endoscopy than in 29 healthy controls. Analysis of reproducibility showed that intraobserver variation was low on both the Glasgow and Likert scores. No differences were found between consecutive tests regardless of whether both were performed by phone (24 patients) or one by phone and the other by clinical interview (40 patients). Interobserver variation analysis showed that the Glasgow test remained highly reproducible even when performed by different observers using different methods (clinical interview 8.83, phone 8.44, P = 0.12). By contrast, Likert-scale tests showed significant differences between observers for all symptoms except abdominal pain.

CONCLUSIONS

(1) The Glasgow score is highly reproducible even when performed by different observers and using different methods. (2) By contrast, Likert tests show greater variability. To be reproducible in different conditions, they need to be performed by the same observer.

Comparative study of antithrombotic effect of a low molecular weight heparin and unfractionated heparin in an ex vivo model of deep arterial injury

Thrombosis after plaque rupture triggers the onset of acute coronary events. The treatment of choice for patients with acute coronary syndromes is conventional unfractionated heparin. Low molecular weight heparin has recently been reported to be as effective and even safer than unfractionated heparin. In this study, the effects of the low molecular weight heparin reviparin and unfractionated heparin on thrombus formation were examined under dynamic conditions using an extracorporeal perfusion chamber in a porcine model. Thrombus formation was assessed by the deposition of porcine 123I-fibrin(ogen) and autologous 111In-platelets on porcine tunica media at high and low shear rates. Reviparin reduced the fibrinogen molecules deposited on injured vessels at high shear rates (252+/-80 molecules x 10(12)/cm2 for reviparine (200 U/kg/hour) vs. 624+/-70 x 10(12)/cm for unfractionated heparin (200 U/kg/hour) (p<0.05). At low shear rates, fibrinogen deposition was also significantly reduced by reviparin (130+/-15 molecules x 10(12)/cm2) compared to unfractionated heparin (192+/-40 x 10(12)/cm2 at 200 U/kg/hour; p<0.05). No change in platelet deposition was detected after heparin administration in either treatment group. In conclusion, the low molecular weight heparin reviparin has a higher antithrombotic potential than unfractionated heparin. Reviparin may have advantages over unfractionated heparin in treatment and prevention of acute coronary syndromes.