FTIR spectra and chain conformations in the crystalline forms and clathrates of syndiotactic poly(p-methylstyrene)

Infrared spectra of syndiotactic poly(p-methylstyrene) (s-PPMS) samples, exhibiting various crystalline forms and clathrate structures, are reported in this contribution. Bands due to the syndiotactic stereostructure, bands typical of the two different chain conformations observed in the crystalline structures and bands sensitive to intermolecular interactions typical of the different modes of packing of chains are pointed out. The observed similarities with the case of syndiotactic polystyrene are alos indicated. A complete assignment, via FTIR analysis, of the chain conformations, is presented for all the known crystalline forms and clathrates of s-PPMS.     

Association of myopathy with large-scale mitochondrial dna duplications and deletions: Which is pathogenic?

We identified large-scale heteroplasmic mitochondrial DNA (mtDNA) rearrangements in a 50–year-old woman with an adult-onset progressive myopathy. The predominant mtDNA abnormality was a 21.2–kb duplicated molecule. In addition, a small population of the corresponding partially deleted 4.6–kb molecule was detected. Skeletal muscle histology revealed fibers that were negative for cytochrome c oxidase (COX) activity and had reduced mtDNA-encoded COX subunits. By single-fiber polymerase chain reaction analysis, COX-negative fibers contained a low number of wild-type or duplicated mtDNA molecules (ie, nondeleted). In situ hybridization demonstrated that the abnormal fibers contained increased amounts of mtDNA compared with normal fibers and that most of the genomes were deleted. We concluded that deleted mtDNA molecules were primarily responsible for the phenotype in this patient.     

Corneal desiccation staining with hydrogel lenses: Tear film and contact lens factors

This investigation monitored the response of established contact lens wearers using contact lenses made from Filcon 4a 77% water-content material in three different thicknesses (0.08, 0.10 and 0.12 mm) over a 6-hour period of wear under adverse environmental conditions. The results obtained showed the following. (1) In accordance with previous studies carried out with lenses of similar water content, the present lenses produced corneal desiccation staining under the challenging conditions of use. However, the staining produced was similar for all three lens thicknesses tested. (2) Corneal desiccation staining was present despite the good and stable fitting characteristics observed during the study, confirming that mechanical trauma is not a necessary cause for soft-lens-induced desiccation staining. (3) Corneal desiccation staining was associated with a rapidly destabilizing pre-lens tear film (PLTF) and a thinning lipid layer. The initial break-up of the PLTF and corneal staining were recorded with a higher incidence in the vertical quadrants than in the horizontal quadrants. The PLTF is thinnest and most unstable at the tear prism margin border, hence least efficacious at preventing evaporation. Corneal desiccation staining may be due, at least partly, to excessive evaporation at the contact lens front surface.     

Serous papillary carcinoma of the endometrium arising from endometrial polyps: a clinical, histological, and immunohistochemical study of 13 cases

Serous papillary carcinoma is an aggressive tumor. Point mutations in the p53 suppressor gene might explain in part the rapid growth of this malignant tumor and its unfavorable outcome. The aims of this study were to evaluate the behavior of serous papillary carcinoma developing in endometrial polyps and to assess the p53 protein overexpression. Patients included in this study were treated in our institution between 1982 and 2003. All clinical and pathological materials were examined. A p53 protein immunohistochemical analysis was performed on paraffin-embedded tissues. Thirteen serous papillary carcinomas arising from benign polyps of the endometrium were identified. The patients' age averaged 73 years. All patients were treated surgically. After an average follow-up of 22 months, 54% of the patients were dead or alive with disease. Of 10 serous papillary carcinomas, 8 (80%) for which paraffin blocks were available overexpressed the p53 protein. A serous papillary carcinoma arising from benign polyps of the endometrium remains a malignant neoplasia with an unfavorable outcome even if the primary tumor is limited to the polyp. The high rate of protein p53 overexpression suggests that a p53 gene mutation occurs early in the disease and might explain the rapid growth of the tumor.     

Frequent carriage of Panton-Valentine leucocidin genes by Staphylococcus aureus isolates from surgically drained abscesses

Between 1 February and 15 April 2002, 95 patients were admitted to Gaston Bourret Territorial Hospital (New Caledonia, France) for drainage of community-acquired soft tissue abscesses. Staphylococcus aureus was detected in 68 cases (72%). Two-thirds of the patients with S. aureus infection had furuncles, which were located on the limbs in 82% of cases. The median interval between symptom onset and hospital admission was 5.7 days. Three-quarters of the patients were Melanesians living in tribes. Fifty-four S. aureus isolates were screened for toxin genes. Panton-Valentine leucocidin (PVL) genes were detected in 48 isolates (89%), the exfoliative toxin A gene was detected in 1 isolate, and no toxin genes were detected in 4 isolates. S. aureus nasal carriage was detected in 39.7% of patients with S. aureus infections. Two infecting S. aureus strains and two nasal carriage strains were resistant to methicillin. Comparative pulsed-field gel electrophoresis, performed in 16 cases, showed that five of six patients with PVL-positive nasal carriage strains were infected by the same strains. In contrast, 8 of 10 patients with PVL-negative nasal carriage strains were infected by PVL-positive strains. PVL genes thus appear to be a major virulence factor in both primary and secondary S. aureus skin infections.     

High risk HPV load estimated by Hybrid Capture II correlates with HPV16 load measured by real-time PCR in cervical smears of HPV16-infected women.

BACKGROUND: High risk human papillomavirus (HR-HPV) load determined by quantitative methods has already been considered as highly predictive of future development of high grade cervical lesions. Some studies also demonstrated that Hybrid Capture II (HCII) results can be considered as a reflection of HPV DNA load, while others did not. HCI assay, well suited for routine HR-HPV screening, is not especially dedicated for quantitative use. However, we have recently shown that women with high viral loads assessed by HCII were at increased risk of cervical precancer. OBJECTIVES: The aim of the study was to determine if the values given by the HCII assay can be considered as quantitative. STUDY DESIGN: We used a real-time PCR allowing precise quantification of both HPV16 genome and albumin gene to normalize the measuring HPV16 load in cervical cells and to compare the data with those obtained by HCIIin a series of 40 HR-HPV positive samples. RESULTS: Reproducibility of the HPV16 real-time PCR, assessed from nine independent experiments of serial dilutions of SiHa cell DNA, was reflected in coefficients of variation for standard curves of crossing point (Cp) values below 5%. The HPV16 loads with a broad individual variability were significantly related to the cumulative load estimated by HCII and did not depend on the cellularity of samples. CONCLUSIONS: We assume that the HCII values can be used as a quantitative measure of HR-HPV DNA, so long as cervical specimens are collected using standardized protocols.     

Electronic implementation of guidelines in the EsPeR system: a knowledge specification method

Despite initiatives to standardize methods for the development of clinical guidelines, several barriers hinder their integration in daily clinical practice: failure to fulfil quality criteria, poor effectiveness of their dissemination. Computerization of guidelines can favor their dissemination. The initial step of computerization is the knowledge specification from the text of the guideline. We describe the method of knowledge specification, which is used in EsPeR (Personalized Estimate of Risks), a web-based decision support system in preventive medicine, which allows, for a given person, to estimate risks and access recommendations, based on clinical profile. This method is based on a structured and systematic analysis of text allowing detailed specification of a decision tree. We use decision tables to validate the decision algorithm and decision trees to specify this algorithm, along with elementary messages of recommendation. Editing tools are used to facilitate the process of validation and the workflow between expert physicians and computer scientists. Applied to eleven different guidelines, the method allows a quick and valid computerization and integration in the EsPeR system. The method used for computerization could help to define a framework usable at the initial step of guideline development in order to produce guidelines ready for electronic implementation.     

HIV infection and AIDS in advanced age. Epidemiological and clinical issues, and therapeutic and management problems

The life expectancy of HIV-infected patients treated with highly active antiretroviral therapy (HAART) has increased and now approaches that of the general population, while also the definition of AIDS has lost most of its epidemiological and clinical significance, due to the immune recovery obtained by large-scale administration of potent antiretroviral combinations. The prolonged survival of subjects with HIV infection, and the late recognition of patients with occult disease, will contribute to a progressive increase in disease incidence in patients aged 50-60 years or more in the near future. Unfortunately, the large majority of therapeutic trials addressed to assess and compare novel antiretroviral molecules and associations, as well as studies regarding antimicrobial chemotherapy of prophylaxis of AIDS-related opportunistic infections, have just advanced age and/or underlying chronic disorders (i.e. liver or kidney failure) among main exclusion criteria, or do not allow the extrapolation of data regarding older subjects, compared with younger ones. The limited data available until now show that antiretroviral therapy has a similar virological efficacy in the elderly compared with younger patients. However, immune reconstitution is often slower and blunted according to age progression, although some well-designed studies have shown that the thymic function (which controls most quantitative and functional immune recovery) can be preserved in adults and even in advanced age. When facing older subjects, the Infectious Disease specialist has to pay careful attention to any chronic end-organ disorders, all possible pharmacological interactions, and overwhelming toxicity due to underlying drug therapies: all these issues may significantly interfere with HAART efficacy, patients' adherence to prescribed treatments, and frequency and severity of untoward events. Guidelines for antiretroviral therapy and treatment and prophylaxis of AIDS-associated illnesses should be appropriately updated, given the novel features due to the emerging increase in the mean age of the HIV-infected patient population.     

Cellulitis and soft tissue infection in patients with HIV disease: epidemiological and microbiological features

In order to assess the epidemiological, microbiological, and clinical features of cellulitis and soft tissue infection occurring during the course of HIV disease, clinical and laboratory data of 2221 hospitalizations carried out since 1991 were retrospectively examined, and 67 bacteriologically-proven episodes of cellulitis-soft tissue infection were identified (3.02% of overall admissions). Among the 92 cultured pathogens, Staphylococcus aureus was the most frequent (46 cases), followed by Pseudomonas spp., Escherichia coli, and Streptococcus pyogenes; 38.1% of patients had a polymicrobial infection. i.v. drug use (p<.02) and the male gender (p<.05), were significantly associated with the occurrence of these complications, while a great variation in the severity of underlying immunodeficiency was shown. An elevated rate (83.6%) of episodes of cellulitis or soft tissue infection were community-acquired in origin; the comprehensive frequency of these episodes significantly dropped during the highly active antiretroviral therapy (HAART) era (p<.01). Limbs were involved in over 80% of episodes, and an hematogenous dissemination of bacterial infection (which occurred in 25.4% of cases), proved significantly related to a CD4+ lymphocyte count <100 cells/microL (p<.03), and an absolute neutrophil count <1000 cells/microL (p<.05). S. aureus strains showed an elevated in vitro resistance rate to penicillin, ampicillin, and rifampin, and a 21.7% rate of methicillin-resistance, while among the 29 gram-negative microorganisms, resistance to ampicillin and first-generation cephalosporins, and that to amoxycillin-clavulanate and second-generation cephalosporin, occurred in over 90% and 60% of tested strains, respectively. All episodes of HIV-associated cellulitis and soft tissue infection were favorably treated in 5-16 days, in over 60% of cases with associated beta-lactam and aminoglycoside antibiotics; a recurrence of staphylococcal cellulitis occurred in 4 patients only, 6-17 months after the initial episode. Cellulitis and soft tissue infection are underestimated complications of HIV disease, but they have a broad etiological and clinical spectrum, are predominantly community-acquired, and are responsible for an appreciable morbidity, due to the supporting role of i.v. drug addiction, and the frequent hematogenous dissemination (which proved to be significantly related to the progression of immunodeficiency and underlying disease). The frequent polymicrobial etiology requires a combination antimicrobial therapy (to be guided by in vitro susceptibility studies), which may avoid a complicated and recurrent disease course in the great majority of cases.