Clinical evaluation of a new automated anti-dsDNA fluorescent immunoassay.

The measurement of anti-double-stranded DNA (anti-dsDNA) antibodies is a useful tool for the diagnosis and the follow-up of systemic lupus erythematosus (SLE). Anti-dsDNA antibodies are involved in the pathogenesis of lupus nephritis and they are, specially the high-avidity antibodies, the most specific antibodies associated with SLE nephritis and active SLE. The aim of the present study was to assess the clinical utility of an enzyme-linked immunosorbent assay (EUSA) that utilizes a circular double-stranded plasmid DNA as a nucleic acid source, adapted to an automated fluorescence immunoassay (EliA dsDNA, Pharmacia, Freiburg, Germany). Also, we compared this method with other immunoassays used in clinical laboratories. We have measured anti-dsDNA antibodies in the serum of 179 patients with a positive result for antinuclear antibodies (ANA). Seventy six sera were from SLE patients (14 men and 62 women), and the other 103 sera (from 20 men and 83 women) constituted the control group. This latter group includes nine Sjogren's syndrome patients, six patients with rheumatoid arthritis and 88 with various other diseases, including connective tissue diseases (n=34), hepatopathies (n= 17; 11 primary biliary cirrhosis and 6 autoimmune hepatitis), and 37 patients with nonautoimmune diseases (viral hepatitis, renal disease, diabetes, exanthema and hypertension). Methods used were "EliA dsDNA" (Pharmacia, Germany), "Varelisa dsDNA" (Pharmacia, Germany), Farr (Amersham, UK) and Chritidia luciliae immunofluorescence test (Vitro-Immun, Germany). We assessed sensitivity, specificity, positive predictive value and negative predictive value in the clinical study, and kappa index and scatter plots in the comparative study. The results show a low concordance between methods (kappa < 0.6). The evaluated EliA method shows a very good specificity for SLE (93.2%) and a good sensitivity for active SLE (70.8%).     

Hypertension in HIV-infected patients: prevalence and related factors

BACKGROUND: Little is known about hypertension in the HIV-infected population. This study aimed to assess the prevalence of hypertension and related factors in HIV-infected patients. METHODS: In this prospective cross-sectional study, 710 HIV-infected patients (626 on combination antiretroviral therapy and 84 naive) managed at the outpatient clinic of a tertiary hospital during 2003 and 802 controls completed the study protocol consisting of medical examination and a 6-month follow-up period including three control visits. RESULTS: Hypertension prevalence was 13.1% in HIV-infected patients and 13.5% in the control group. Age (per 10-year increment) (odds ratio [OR]: 1.92; 95% confidence interval [CI]: 1.48-2.48), body mass index (OR: 1.18; 95% CI: 1.10-1.27), and lipoaccumulation pattern of fat redistribution (OR: 2.26; 95% CI: 1.20-4.24) were independently and significantly associated with the presence of hypertension in HIV-infected patients at logistic regression analysis. CONCLUSIONS: The present results suggest no meaningful difference in prevalence of hypertension between subjects with and without HIV infection. Thus, the influence of combination antiretroviral therapy appears to have little impact on the prevalence of hypertension.     

Diadenosine polyphosphate receptors. from rat and guinea-pig brain to human nervous system

Diadenosine polyphosphates are a family of naturally occurring nucleotidic compounds present in secretory vesicles together with other chemical messengers. The exocytotic release of these compounds permits them to stimulate receptors termed "purinoceptors" or "ATP receptors." Purinoceptors for nucleotides are named P2 in contrast with those sensitive to nucleosides (P1). P2 receptors are further subdivided into metabotropic P2Y receptors, further divided into 5 subtypes, and ionotropic P2X receptors, with 7 different subtypes. Diadenosine polyphosphates can activate recombinant P2Y(1), P2Y(2), and P2Y(4) and recombinant homomeric P2X(1), P2X(2), P2X(3), P2X(4), and P2X(6). Heteromeric P2X receptors change their sensitivity to diadenosine polyphosphates when co-assembly between different subunits occurs. Diadenosine polyphosphates can activate specific receptors termed dinucleotide receptors or P4 receptors, which are insensitive to other nucleosides or nucleotides. The P4 receptor is a receptor-operated Ca(2)+ channel present in rat brain synaptic terminals, stimulated by diadenosine pentaphosphate and diadenosine tetraphosphate. This receptor is strongly modulated by protein kinases A and C and protein phosphatases. The dinucleotide receptor is present in different brain areas, such as midbrain (in rat and guinea-pig), cerebellum (in guinea-pig), and cortex (in human).     

Derivation of sarcomas from mesenchymal stem cells via inactivation of the Wnt pathway

Malignant fibrous histiocytoma (MFH), now termed high-grade undifferentiated pleomorphic sarcoma, is a commonly diagnosed mesenchymal tumor, yet both the underlying molecular mechanisms of tumorigenesis and cell of origin remain unidentified. We present evidence demonstrating that human mesenchymal stem cells (hMSCs) are the progenitors of MFH. DKK1, a Wnt inhibitor and mediator of hMSC proliferation, is overexpressed in MFH. Using recombinant proteins, antibody depletion, and siRNA knockdown strategies of specific Wnt elements, we show that DKK1 inhibits hMSC commitment to differentiation via Wnt2/beta-catenin canonical signaling and that Wnt5a/JNK noncanonical signaling regulates a viability checkpoint independent of Dkk1. Finally, we illustrate that hMSCs can be transformed via inhibition of Wnt signaling to form MFH-like tumors in nude mice, and conversely, MFH cells in which Wnt signaling is appropriately reestablished can differentiate along mature connective tissue lineages. Our results provide mechanistic insights regarding the cell of origin of MFH, establish what we believe is a novel tumor suppressor role for Wnt signaling, and identify a potential therapeutic differentiation strategy for sarcomas.     

Active Bax and Bak are functional holins

The mechanism of Bax/Bak-dependent mitochondrial outer membrane permeabilization (MOMP), a central apoptotic event primarily controlled by the Bcl-2 family proteins, remains not well understood. Here, we express active Bax/Bak in bacteria, the putative origin of mitochondria, and examine their functional similarities to the λ bacteriophage (λ) holin. As critical effectors for bacterial lysis, holin oligomers form membrane lesions, through which endolysin, a muralytic enzyme, escapes the cytoplasm to attack the cell wall at the end of the infection cycle. We found that active Bax/Bak, but not any other Bcl-2 family protein, displays holin behavior, causing bacterial lysis by releasing endolysin in an oligomerization-dependent manner. Strikingly, replacing the holin gene with active alleles of Bax/Bak results in plaque-forming phages. Furthermore, we provide evidence that active Bax produces large membrane holes, the size of which is controlled by structural elements of Bax. Notably, lysis by active Bax is inhibited by Bcl-xL, and the lysis activity of the wild-type Bax is stimulated by a BH3-only protein. Together, these results mechanistically link MOMP to holin-mediated hole formation in the bacterial plasma membrane.     

Estudio prospectivo controlado y aleatorizado sobre la necesidad de la preparación mecánica de colon en la cirugía programada colorrectal

Introduction

Mechanical preparation of the colon (MPC) in colorectal surgery has been a dogma that has been questioned over the last few years. The objective of this study is to demonstrate that morbidity in scheduled colorectal surgery is the same or lower without MPC.

Material and method

Patients subjected to scheduled left colon and rectal surgery with primary anastomosis randomised into two groups. The “Preparation” group (MPC) received MPC and the “non-preparation” group (No-MPC) had only cleaning enemas. The variables collected were: demographic, oncological, nutritional, risk prediction models and morbidity-mortality.

Results

Of the 193 patients included: 69 received MPC and 71 did not; 89 patients with colocolic anastomosis (MPC, 38; no MPC, 51) and 50 colorectal (MPC, 31; no MPC, 19). Statistically significant differences were seen in the overall analysis in favour of “no preparation” as regards morbidity (43.55 % with MPC and 27% with No MPC) and nosocomial infection (27.5% and 11.4%). There was 11.6% wound infections in the MPC compared to 5.7% in the no MPC, which was not statistically significant. The only mortalities were in the MPC group 2/69 (2.9% of patients). As regards the location of the anastomosis, in the colocolics the differences were more pronounced, with statistically significant differences in the morbidity, anastomosis dehiscence, and nosocomial infection variables. The effect of no MPC was not so evident in colorectal anastomosis.

Conclusions

Our results suggest that there is no benefit in MPC before surgery in colocolic anastomosis. No-MPC is not associated with a higher morbidity in wound infection or anastomotic dehiscence. In colorectal anastomosis the differences are not so evident, therefore a much bigger series needs to be studied.     

Primary Extracranial Meningiomas: An Analysis of 146 Cases

Primary extracranial meningiomas are rare neoplasms, frequently misdiagnosed, resulting in inappropriate clinical management. To date, a large clinicopathologic study has not been reported. One hundred and forty-six cases diagnosed between 1970 and 1999 were retrieved from the files of the Armed Forces Institute of Pathology. Histologic features were reviewed, immunohistochemistry analysis was performed (n = 85), and patient follow-up was obtained (n = 110). The patients included 74 (50.7%) females and 72 (49.3%) males. Tumors of the skin were much more common in males than females (1.7:1). There was an overall mean age at presentation of 42.4 years, with a range of 0.3–88 years. The overall mean age at presentation was significantly younger for skin primaries (36.2 years) than for ear (50.1 years) and nasal cavity (47.1 years) primaries. Symptoms were in general non-specific and reflected the anatomic site of involvement, affecting the following areas in order of frequency: scalp skin (40.4%), ear and temporal bone (26%), and sinonasal tract (24%). The tumors ranged in size from 0.5 up to 8 cm, with a mean size of 2.3 cm. Histologically, the majority of tumors were meningothelial (77.4%), followed by atypical (7.5%), psammomatous (4.1%) and anaplastic (2.7%). Psammoma bodies were present in 45 tumors (30.8%), and bone invasion in 31 (21.2%) of tumors. The vast majority were WHO Grade I tumors (87.7%), followed by Grade II (9.6%) and Grade III (2.7%) tumors. Immunohistochemically, the tumor cells labeled for EMA (76%; 61/80), S-100 protein (19%; 15/78), CK 7 (22%; 12/55), and while there was ki-67 labeling in 27% (21/78), <3% of cells were positive. The differential diagnosis included a number of mesenchymal and epithelial tumors (paraganglioma, schwannoma, carcinoma, melanoma, neuroendocrine adenoma of the middle ear), depending on the anatomic site of involvement. Treatment and follow-up was available in 110 patients: Biopsy, local excision, or wide excision was employed. Follow-up time ranged from 1 month to 32 years, with an average of 14.5 years. Recurrences were noted in 26 (23.6%) patients, who were further managed by additional surgery. At last follow-up, recurrent disease was persistent in 15 patients (mean, 7.7 years): 13 patients were dead (died with disease) and two were alive; the remaining patients were disease free (alive 60, mean 19.0 years, dead 35, mean 9.6 years). There is no statistically significant difference in 5-year survival rates by site: ear and temporal bone: 83.3%; nasal cavity: 81.8%; scalp skin: 78.5%; other sites: 65.5% (P = 0.155). Meningiomas can present in a wide variety of sites, especially within the head and neck region. They behave as slow-growing neoplasms with a good prognosis, with longest survival associated with younger age, and complete resection. Awareness of this diagnosis in an unexpected location will help to avoid potential difficulties associated with the diagnosis and management of these tumors.     

Global cardiovascular risk in patients with HIV infection: concordance and differences in estimates according to three risk equations (Framingham, SCORE, and PROCAM)

To compare cardiovascular risk stratification according to Framingham, PROCAM (Prospective Cardiovascular Münster), and SCORE (Systematic Coronary Risk Evaluation) equations in patients with HIV infection, a cross-sectional study of a well-characterized cohort of 760 HIV-infected adults managed at the outpatient Infectious Disease Unit in 2003 was conducted. Cardiovascular risk score was examined and patients were classified as having low, moderate, or high risk using Framingham and PROCAM (<10%, 10%-20%, and <20%, respectively) and SCORE (<3%, 3%-4%, and >/=5%, respectively) equations. The prevalence of patients with low, moderate and high cardiovascular risk was 76.6%, 15.1%, and 8.3% by the Framingham, respectively, 90.1%, 4.9%, and 5% by the PROCAM, respectively, and 88.6%, 3%, and 8.4% by SCORE, respectively. Concordance between these three risk functions was significant, but globally moderate (Framingham and PROCAM, kappa 0.36, p < 0.0001; Framingham and SCORE, kappa 0.32, p < 0.0001; PROCAM and SCORE, kappa 0.46, p < 0.0001). The Framingham equation categorized a higher proportion of HIV-infected male patients with moderate cardiovascular risk and a lower proportion of those with low risk (p < 0.0001) compared with PROCAM and SCORE. The present study showed a high prevalence of HIV-infected patients at low cardiovascular risk regardless of the assessed coronary risk system used. However, compared with PROCAM and SCORE, Framingham risk equation in HIV-infected patients identified a higher number of male patients with moderate cardiovascular risk.