Multiple sclerosis and Epstein-Barr virus: a growing association

The etiology of multiple sclerosis is an elusive field due to the lack of the usual cause-effect relationship model to explain a disease. In fact, with all the current evidence we start thinking in multiple sclerosis as a multi-factorial disease, where an infective agent on a genetically permissive host can lead to inflammation, demyelination and ultimately to neurological damage with dire consequences for the patients. This review will focus on the role of viruses in multiple sclerosis etiology and give some insight regarding this complicated issue.

Molecular analysis of the replication region of the pCIZ2 plasmid from the multiple bacteriocin producer strain Enterococcus faecium L50

The sequence analysis of the 7383 bp plasmid pCIZ2 from Enterococcus faecium L50 enabled the identification of a DNA region involved in its replication. The structural organization of the pCIZ2 replication region is highly similar to those of well-known theta-replicating plasmids. It contains an untranslated region, the putative replication origin (ori), constituted by two sets of direct repeats of 12 and 22 bp (iterons), and followed by three open-reading frames (orf8 to orf10). orf8 encodes the replication initiation protein (RepE). The transcriptional start site of the replication locus was identified 13 nucleotides upstream of the repE start codon. A two-dimensional agarose gel electrophoresis analysis revealed pCIZ2 intermediates profile typical of the theta-type replication mechanism. Subcloning of different DNA fragments of the pCIZ2 replication region in Escherichia coli and, subsequently, in the plasmidless E. faecium L50/14-2 allowed the determination of the minimal replicon on a 1.2kb DNA fragment containing only the overall ori and repE which also act in trans. The involvement of orf9 in the plasmid copy number and in the plasmid stability was investigated. The pCIZ2 recombinant plasmids constitute narrow-host range shuttle cloning vectors (E. coli-E. faecium) that could be very useful for enterococcal genes studies, allowing an easy identification due to their histochemical recognition.

Regulation of proliferation and differentiation of adipocyte precursor cells in rainbow trout (Oncorhynchus mykiss)

Here, we describe optimal conditions for the culture of rainbow trout (Oncorhynchus mykiss) pre-adipocytes obtained from adipose tissue and their differentiation into mature adipocytes, in order to study the endocrine control of adipogenesis. Pre-adipocytes were isolated by collagenase digestion and cultured on laminin or 1% gelatin substrate. The expression of proliferating cell nuclear antigen was used as a marker of cell proliferation on various days of culture. Insulin growth factor-I stimulated cell proliferation especially on days 5 and 7 of culture. Tumor necrosis factor alpha (TNFalpha) slightly enhanced cell proliferation only at a low dose. We verified the differentiation of cells grown in specific medium into mature adipocytes by oil red O (ORO) staining. Quantification of ORO showed an increase in triglycerides throughout culture. Immunofluorescence staining of cells at day 11 revealed the expression of CCAAT/enhancer-binding protein and peroxisome proliferator-activator receptor gamma, suggesting that these transcriptional factors are involved in adipocyte differentiation in trout. We also examined the effect of TNFalpha on the differentiation of these adipocytes in primary culture. TNFalpha inhibited the differentiation of these cells, as indicated by a decrease in glycerol-3-phosphate dehydrogenase activity, an established marker of adipocyte differentiation. In conclusion, the culture system described here for trout pre-adipocytes is a powerful tool to study the endocrine regulation of adipogenesis in this species.

Observation of the suppression of the flux of cosmic rays above 4 x 10 (19) eV

The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

Upper limit on the diffuse flux of ultrahigh energy tau neutrinos from the Pierre Auger Observatory

The surface detector array of the Pierre Auger Observatory is sensitive to Earth-skimming tau neutrinos that interact in Earth's crust. Tau leptons from nu(tau) charged-current interactions can emerge and decay in the atmosphere to produce a nearly horizontal shower with a significant electromagnetic component. The data collected between 1 January 2004 and 31 August 2007 are used to place an upper limit on the diffuse flux of nu(tau) at EeV energies. Assuming an E(nu)(-2) differential energy spectrum the limit set at 90% C.L. is E(nu)(2)dN(nu)(tau)/dE(nu)<1.3 x 10(-7) GeV cm(-2) s(-1) sr(-1) in the energy range 2 x 10(17) eV< E(nu)< 2 x 10(19) eV.

The relation among the diameter of the great saphenous vein, clinical state and haemodynamic pattern of the saphenofemoral junction in chronic superficial venous insufficiency

OBJECTIVE

To find out if there is a relation among the diameter of the great saphenous vein (GSV) when it is incompetent, the clinical gravity of the varicose syndrome and the type of insufficiency of the saphenofemoral junction (SFJ) in patients with chronic venous insufficiency (CVI) by means of duplex exploration.

METHODS

The sample included 145 extremities, 38 normal as a control group and 107 with incompetence of the GSV. According to the results of the Valsalva and Parana manoeuvres in the SFJ, they were distributed into four groups. The diameter of the GSV and the clinical state according to the clinical, aetiological, anatomical and pathological element classification were recorded for each group.

RESULTS

Statistically significant differences were obtained for the diameter and the clinical state in patients with positive manoeuvres with regard to other groups. The diameter was greater and the clinical state more severe (C4, C5 and C6) when two manoeuvres were positive.

CONCLUSIONS

The presence of both positive manoeuvres in the SFJ is related to severe clinical states and greater diameters of the GSV, allowing the establishment of a prognosis of the CVI and the most suitable surgical approach.

[Analysis of lung cancer cases diagnosed in an internal medicine department: from January 2001 to September 2006]

BACKGROUND

Lung cancer is one of the main health problems in the developed world. Our aims were to determine the symptomatic time prior to a specific diagnosis, the clinical and histological characteristics of the cases of lung cancer diagnosed in a department of internal medicine, and to analyze the survival factors.

MATERIAL AND METHODS

We studied retrospectively all patients diagnosed with lung cancer in the internal medicine department in the period between January 2001 and September 2006 reviewing clinical records. We specifically recorded age, gender, smoking habit, time and type of symptomatic presentation, radiological manifestations, methods of histological diagnosis, tumour staging, and performance status measured by ECOG classification. We also evaluated the factors associated with the survival time.

RESULTS

In this period 124 patients were diagnosed with lung cancer [mean age 68 +/-12 years, male 105 (85%), female 18 (15%), smokers 85%]. The mean symptomatic time before hospitalization was 74.5 +/-7 days. On hospitalization, respiratory symptoms were present in 40 (32%) patients. Tumour staging was carried out in 120 (97%) patients. In 96 (77%) patients non-small lung cancer was diagnosed, 62 (64%) in stage IV. In 28 (23%) patients small lung cancer was diagnosed, 22 (79%) in extended stage. Median time to diagnosis as an in-patient was 7 days. One hundred and thirteen (91%) patients died with a median survival time of 3 months. Factors associated with longer survival were the performance status and tumour stage.

CONCLUSIONS

In this community, lung cancer is diagnosed late and in advanced stages, with a high mortality rate. A better performance status and lower tumour stages appear to be associated with longer survival.

Diabetes team consultation: impact on length of stay of diabetic patients admitted to a short-stay unit

OBJECTIVE

To assess the impact of endocrinology team consultation on hospital stay and clinical outcomes of diabetic patients admitted with a primary non-diabetes-related diagnosis in a short stay unit (SSU).

METHODS

Patients admitted to the SSU between 2001 and 2005. Between 2001 and 2003 there was no endocrinology team consultation available and the management of hyperglycemia was handled by the SSU team alone. From 2003 until 2005 an endocrinology team was in charge of diabetes care. We compared in both periods: prevalence of diabetes, length of hospital stay, mortality, early readmissions and number of patients requiring conventional hospitalization.

RESULTS

In period 2001-2003, 1023 patients were admitted, among which 212 were diabetic (20.7%). Over the years 2003-2005, 892 patients were hospitalized, 223 were diabetic (25%). Clinical characteristics of diabetic patients from both periods were comparable, but glycaemia at admission was higher on the second period (217 mg/dl versus 198 mg/dl). The length of stay of diabetic patients in the second period decreased from 5.49 to 4.90 days. There were no significant differences in mortality (1.4% versus 0.4%) or in early re-admissions among the two periods.

CONCLUSIONS

The intervention of a diabetes team diminished the average length of stay of diabetic patients.

Activityin vitro of twelve antibiotics against clinical isolates of extended-spectrum beta-lactamase producing Escherichia coli

Twelve beta-lactam and non-beta-lactam antibiotics were evaluated against 115 clinical isolates of extended-spectrum beta-lactamase-producing (ESBLs) Escherichia coli using a broth microdilution test in accordance with the CLSI guidelines. Susceptibility was 100% with imipenem, ertapenem and amikacin, 95.7% with piperacillin-tazobactam, 91.3% with cefoxitin, 87% with tobramycin, 81.7% with amoxicillin-clavulanate, 80% with cefepime, 67.8% with ceftazidime, 27.8% with ciprofloxacin, 27% with levofloxacin and 13% with ceftriaxone. Ertapenem was the antibiotic with the lowest minimum inhibitory concentrations (MICs) for all isolates. There were no clinically relevant differences in the activity of the antibiotics in the presence of CTX-M-9 or SHV enzymes.

High presence of extended-spectrum β-lactamases and resistance to quinolones in clinical isolates of Escherichia coli

A study was conducted to detect the presence of extended-spectrum beta-lactamases (ESBLs) in 706 isolates of Escherichia coli, largely from outpatients (75.2%). The Clinical and Laboratory Standards Institute (formerly NCCLS)-recommended disk diffusion procedure was used to detect ESBL presence; the VITEK 2 system (bioMérieux, Marcy L'Etoile, France) was used to determine the susceptibility to antibiotics of clinical interest, and the ESBLs were characterized by biochemical study, determining the isoelectric point, and by molecular study with PCR. Clonal distribution was studied in eight hospital isolates. There were 115 ESBL-producing isolates (16.3%), with a predominance of CTX-M9 type (58.3%). We draw attention to the high resistance to quinolones (>70%) in CTX-M9 and SHV enzyme producing isolates and the lower aminoglycoside activity in the latter.

Insulin regulation of lipoprotein lipase (LPL) activity and expression in gilthead sea bream (Sparus aurata)

Lipoprotein lipase (LPL) is a key enzyme in lipoprotein metabolism by virtue of its capacity to hydrolyze triglycerides circulating in the form of lipoprotein particles. Here we analyzed the fasting effects of LPL in gilthead sea bream (Sparus aurata) and also present the first study in fish of the role of insulin as a potential modulator of both LPL activity and expression. Fasting for 2 weeks provoked a clear decrease in adipose tissue LPL activity, concomitant with lower levels of plasma insulin, while no effects were observed in red muscle. To elucidate the specific role of insulin, increases of plasma insulin were experimentally induced by arginine and insulin injections. However, arginine predominantly stimulated glucagon over insulin secretion in this fish species while LPL activity did not change significantly in adipose tissue. Instead, insulin administration induced an increase in adipose tissue LPL activity 3 h after the injection, whereas LPL activity in red muscle was not affected. Changes in LPL activity were accompanied by an increase in LPL mRNA levels in the adipose tissue of insulin-injected gilthead sea bream, although changes in LPL expression were delayed in time with respect to variations in LPL activity. Finally, LPL mRNA levels in red muscle were similar between control and insulin-injected gilthead sea bream, suggesting that insulin does not play a direct role in the regulation of LPL in this tissue. The current study shows that LPL activity is regulated by nutritional condition and underscores the importance of insulin as a modulator of LPL activity and expression in the adipose tissue of gilthead sea bream.

[Urinary infection by E. coli complicated with multiple abscesses]

Vertebral osteomyelitis and septic arthritis are pathologies that principally affect people over fifty years old, but their incidence seems to be growing due to the increase of nosocomial bacteraemia associated with intravascular devices and the aging of hospitalised people. The majority of cases are produced by Staphylococcus aureus. We present the case and diagnostic process of a patient with vertebral osteomyelitis caused by another organism, Escherichia coli, with fatal evolution despite adequate treatment.

Strong isotropic flux pinning in solution-derived YBa2Cu3O7-x nanocomposite superconductor films

Power applications of superconductors will be tremendously boosted if an effective method for magnetic flux immobilization is discovered. Here, we report the most efficient vortex-pinning mechanism reported so far which, in addition, is based on a low-cost chemical solution deposition technique. A dense array of defects in the superconducting matrix is induced in YBa(2)Cu(3)O(7-x)-BaZrO(3) nanocomposites where BaZrO(3) nanodots are randomly oriented. Non-coherent interfaces are the driving force for generating a new type of nanostructured superconductor. Angle-dependent critical-current measurements demonstrate that a strong and isotropic flux-pinning mechanism is extremely effective at high temperatures and high magnetic fields leading to high-temperature superconductors with record values of pinning force. The maximum vortex-pinning force achieved at 65 K, 78 GN m(-3), is 500% higher than that of the best low-temperature NbTi superconductors at 4.2 K and so a great wealth of high-field applications will be possible at high temperatures.

Chromatin Remodeling by SWI/SNF Results in Nucleosome Mobilization to Preferential Positions in the Rat Osteocalcin Gene Promoter

Changes in local chromatin structure accompany transcriptional activation of eukaryotic genes. In vivo these changes in chromatin organization can be catalyzed by ATP-dependent chromatin-remodeling complexes, such as SWI/SNF. These complexes alter the tight wrapping of DNA in the nucleosomes and can facilitate the mobilization of the histone octamer to adjacent DNA segments, leaving promoter regulatory elements exposed for transcription factor binding. To gain understanding of how the activity of SWI/SNF complexes may be modulated by the different DNA sequences within a natural promoter, we have reconstituted nucleosomes containing promoter segments of the transcriptionally active cell type-specific osteocalcin (OC) gene and determined how they affect the directional movements of the nucleosomes. Our results indicate that SWI/SNF complexes induce octamer sliding to preferential positions in the OC promoter, leading to a nucleosomal organization that resembles that described in intact cells expressing the OC gene. Our studies demonstrate that the position of the histone octamer is primarily determined by sequences within the OC promoter that include or exclude nucleosomes. We propose that these sequences are critical components of the regulatory mechanisms that mediate expression of this tissue-specific gene.

Atoxoplasma spp. Infection in Captive Canaries (Serinus canaria)

Clinical signs, histopathological and ultrastructural findings associated with Atoxoplasma spp. natural infection in captive canaries (Serinus canaria) are described. Intracytoplasmic Atoxoplasma-like protozoa were found in the liver and lung. In the liver, protozoa were found in hepatocytes and Kupffer's cells and were associated with granulomatous hepatitis and a marked bile duct hyperplasia. An usual finding was the presence of infected mononuclear cells adhered to the endothelium of the blood vessels in lung. The diagnosis was confirmed by ultrastructural examination of reprocessed paraffin-embedded tissues.

Role of insulin, insulin-like growth factors, and muscle regulatory factors in the compensatory growth of the trout (Oncorhynchus mykiss)

To examine the various mechanisms involved in compensatory growth in Oncorhynchus mykiss, an experimental protocol involving 1, 2 or 4 weeks of fasting followed by a single ad libitum re-feeding period of 4 weeks was designed for alevins. Morphological parameters including body weight, specific growth rates (SGR), and coefficient factor decreased significantly during fasting. Re-feeding accelerated growth and restored final body weight in groups previously fasted. Plasma insulin and glucose decreased in fasting, while normal levels were restored in all re-fed groups. The expression profile of insulin-like growth factors (IGFs) in liver and of the main muscle growth regulators in white muscle was examined using real-time quantitative RT-PCR. Fasting decreased the expression of IGF-I mRNA in both tissues, while re-feeding restored expression to control values. In contrast, IGF-II expression was not affected by any treatment in either tissue. Insulin- and IGF-I-binding assays in partial semi-purifications (of soluble proteins) in white skeletal muscle showed that insulin binding was not affected by either fasting or re-feeding, whereas fasting up-regulated IGF-I binding. The expression of IGFRIb mRNA in white skeletal muscle also increased with fasting, while IGFRIa increased with re-feeding, indicating that the two receptor isoforms are differentially regulated. The mRNA expression of myogenic regulator factors and fibroblast growth factors (FGFs) was not affected throughout the experiment, except for myogenin, which first decreased and then showed a rebound effect after 4 weeks of fasting. Myostatin mRNA expression did not change during fasting, although re-feeding caused a significant decrease. In conclusion, re-feeding of previously fasted trout induced compensatory growth. The differential regulation in muscle expression of IGF-I, IGF-I receptors, and myostatin indicates their contribution to this compensatory mechanism.

413 ULTRASONOGRAPHIC EVALUATION OF FETAL LIVER SIZE DURING PREGNANCY IN BOVINE CLONED FETUSES

In ruminants, abnormal increased liver size is a common description cited in many postmortem studies performed on aborted fetuses and stillborn cloned calves (Heyman et al. 2002 Biol. Reprod. 66, 6–13). Although fetal liver size can be accurately determined throughout pregnancy using ultrasonography as a method of monitoring fetal health in humans, there are no reports of this being done in cattle. Thus, the aim of this study was to prospectively characterize the ultrasonographic fetal liver growth pattern in IVF-derived pregnancies, and then to establish comparisons with measurements taken from cloned fetuses. For this purpose, (A) IVF-derived pregnancies were used as the control group (n = 10), and the cloned ones were split into 2 groups according to the outcome of their pregnancies: (B) clones that died between 110 and 282 days (n = 21), and (C) clones born alive (n = 16). All recipients were multiparous, nonlactating, and Aberdeen Angus breed. Measurements were done by ultrasonography (Toshiba Nemio 20, Tokyo, Japan) using a 5–10 MHz intraoperative finger probe from 72 to 114 days (transrectal) and a 3–6 MHz linear-array probe between 143 and 212 days (transabdominal). Three parameters of liver size were measured: (a) in a coronal (longitudinal) plane of the fetus, cephalocaudal diameter (CC) was taken from the dome of the right hemi-diaphragm to the tip of the right lobe; (b) in an axial (transverse) plane at right angles to one another passing through or slightly caudal to the portal umbilical venous complex: (b1) transverse diameter (TD) and (b2) sagittal diameter (SD) were determined (Gimondo et al. 1995 J. Ultrasound Med. 14, 327–333). A repeated-measure ANOVA detected significant interaction for the 3 variables included in this study (P &lt; 0.01); therefore, differences between groups at each week of gestation were analyzed using the Wald-Wolfowitz test (InfoStat V1.5; FCA, Universidad de Córdoba, Córdoba, Argentina). Results showed that CC, TD, and SD were statistically smaller in the IVF group throughout pregnancy (P &lt; 0.05). No significant differences between (B) and (C) groups were found at 72 and 87 days (P &gt; 0.05). However, from 143 days onward, liver of fetuses from the (B) group were statistically larger in CC, TD, and SD diameters than those values obtained in the (A) and (C) groups (P &lt; 0.05) (Table 1). To conclude, the present study showed that fetal liver size can be measured throughout gestation in cows using noninvasive ultrasonography. Secondly, since fetuses from (A) and (C) groups were born alive, increased abnormal size measurements after 140 days can be used as indicator of clones that fail late in gestation (B). Also, this methodology may enhance sonographic assessment of fetal growth abnormalities and conditions with fetal liver involvement. Further studies will be necessary to evaluate differences between naturally conceived and IVF fetuses and the correspondence of this three-dimensional evaluation of the liver and to estimate its weight. Table 1. TD and SD at 72, 143, and 212 days of gestation in (A), (B), and (C) groups (n = 16) (mean ± SD)

How healthy are clones and their progeny: 5 years of field experience

There is considerable concern regarding the health of cloned cattle and their safety as a source of food. The objective was to summarize 5 years of commercial experience with cloning in three countries (United States, Argentina and Brazil). Overall, only 9% of transferred embryos resulted in calves; efficiency ranged from 0 to 45% (most were from 1 to 10%, but 24% of cell lines never produced live calves). There was no significant difference in pregnancy rate following transfer of one versus two embryos. Before 90 days of gestation, two ultrasound markers for embryo death were found, either crown rump length (CRL) or heart beat less than 7.5mm and 150bpm, respectively, were observed alone or together in 27% of clones that died. In addition, after 100 days of pregnancy, placental edema, hydrops fetalis and increased abdominal circumference size were used as ultrasound findings of a fetus at risk of loss. At 114 days of gestation, abdominal circumference in clones that died was statistically larger than in clones that survived alive to term and from MOET- and IVF-derived pregnancies (P<0.05). Since elective cesarean section (C-section) was partially replaced by natural or assisted parturition, C-section rates decreased from 100% in 2000 to 54% in 2005. On average, 42% of cloned calves died between delivery and 150 days of life; the most common abnormalities were: enlarged umbilical cord (37%), respiratory problems (19%), calves depressed/prolonged recumbency (20%) and contracted flexor tendons (21%). From 11 blood parameters evaluated during the first week of life, lactate decreased twice and glucose doubled its original value from 24h to 7 days. Adult cloned females had normal breeding and calving rates and cloned bulls produced good quality semen and had normal fertility when used for AI or natural mating. In conclusion, cloning had no risks qualitatively different from those encountered in animals involved in modern agricultural practices, although the frequency of the risks appeared to be increased in cattle during the early portions of the life cycle of cattle clones.

414 COLOR DOPPLER EVALUATION OF UMBILICAL BLOOD FLOW DURING PREGNANCY IN COWS

There are few reports describing the use of Doppler for reproductive imaging in large animals; only one study (in mares) assessed umbilical blood flow (Bollwein et al. 2004 Theriogenology 61, 499–509). Conditions that constrict the placental vascular bed (i.e. hemorrhage, thrombosis, abnormal development, etc.) increase resistance to incoming blood. Thus, blood flow in umbilical arteries can be used to monitor placental development and function (Giles et al. 1985 Brit. J. Obstet. Gynaecol. 92, 31–38). The objective of the present study was to characterize the Doppler flow velocity waveform in umbilical arteries of cows with apparently normal pregnancies. Twenty-three multiparous, nonlactating Aberdeen Angus cows with pregnancies achieved after transfer of embryos derived by IVF (n = 10) or multiple ovulation and embryo transfer (MOET) (n = 13) were examined weekly from 5 to 38 weeks of gestation. Ultrasonography (Toshiba Nemio 20, Tokyo, Japan) was done using a 5–10 MHz intraoperative finger transducer (transrectal) from 5 to 17 weeks of pregnancy and thereafter using a 3–6 MHz linear-array transducer (transabdominal). The interrogation angle (between the ultrasound beam and the artery) ranged from 45° to 60°. Three resistance indices were calculated: A/B ratio, Resistance Index (RI) = (A − B)/A, and Pulsatility Index (PI) = (A − B)/M. [A = systole, B = diastole, and M = mean maximum Doppler-Shift frequency over the cardiac cycle.] The mean ± SEM duration of pregnancy was 285 ± 1.6 days (range: 269 to 291 days). A repeated measure ANOVA was used to detect differences between groups for every week using the Wald-Wolfowitz test (InfoStat V1.5, FCA, Universidad de Córdoba, Córdoba, Argentina). All 3 resistance indices decreased (by &gt;50%) until 26 weeks, with no substantial change thereafter (Table 1). From 5 to 18 weeks of pregnancy, blood flow was characterized by a systolic pattern (i.e. high resistance with absence of diastolic flow); at 20 weeks, all fetuses had a diastolic flow, consistent with low resistance. There were differences (P &lt; 0.05) between IVF- and MOET-derived pregnancies for RI and PI at 38 and 26 weeks of gestation, respectively, indicating differences in the placental vascular development at these weeks of gestation. In conclusion, umbilical cord blood flow in cattle was characterized by high resistance (5 weeks of gestation), but resistance decreased until 26 weeks; consequently, blood flow was initially systolic but became diastolic. Doppler sonography was useful for assessment of umbilical blood flow from 5 to 38 weeks of pregnancy, and may be useful for assessing placental function in pregnancies under risk, e.g. clone-derived pregnancies (Bertolini et al. 2002 Theriogenology 57, 181–187). Table 1. RI and PI at 19, 22, 26, 30, and 38 weeks of pregnancy in IVF- and MOET-derived pregnancies (mean ± sd)

Meta-analysis of studies analyzing the relationship between bladder cancer and infection by human papillomavirus

PURPOSE

Studies have been done of the possibility that infection by human papillomavirus is a risk factor contributing to bladder cancer but no definite conclusions have yet been drawn. We performed a meta-analysis of observational studies published until July 2005 to ascertain the degree of association between bladder cancer and human papillomavirus infection.

MATERIALS AND METHODS

The MEDLINE database was searched using the key words bladder cancer and virus. Strict criteria were applied to select studies revealing the prevalence in serum of human papillomavirus infection or its direct detection in patients. A total of 44 articles with these methodological criteria were chosen.

RESULTS

In 39 studies the investigators determined the presence of human papillomavirus DNA, and found a prevalence of between 0% and 100% and significant homogeneity analysis (p <0.001). Pooled estimation of the presence of the infection was 16.0% (95% CI 12.8 to 19.1). Pooled OR estimation was 2.3 (95% CI 1.3 to 4.1) with no significant publication bias. In 7 studies human papillomavirus infection was studied by detecting the antigen or antibodies and a prevalence of between 14% and 60% was found with significant homogeneity analysis (p <0.001). Pooled estimation of the prevalence of infection was 32.4% (95% CI 17.0 to 47.8). Pooled OR estimation was 2.9 (95% CI 1.7 to 5.3).

CONCLUSIONS

Finding a relationship between bladder cancer and human papillomavirus depends on the method used. In the literature examined there are insufficient cases and samples compared to controls and studies rely on a combination of various microbiological techniques in the same patient and sample, making it difficult to draw any definite conclusion.