Effects of caffeine on central and peripheral fatigue following closed- and open-loop cycling exercises

We examined whether endurance performance and neuromuscular fatigue would be affected by caffeine ingestion during closed- and open-loop exercises. Nine cyclists performed a closed-loop (4,000-m cycling time trial) and an open-loop exercise (work rate fixed at mean power of the closed-loop trial) 60 min after ingesting caffeine (CAF, 5 mg/kg) or placebo (PLA, cellulose). Central and peripheral fatigue was quantified via pre- to post-exercise decrease in quadriceps voluntary activation and potentiated twitch force, respectively. Test sensitivity for detecting caffeine-induced improvements in exercise performance was calculated as the mean change in time divided by the error of measurement. Caffeine ingestion reduced the time of the closed-loop trial (PLA: 375.1±14.5 s vs CAF: 368.2±14.9 s, P=0.024) and increased exercise tolerance during the open-loop trial (PLA: 418.2±99.5 s vs CAF: 552.5±106.5 s, P=0.001), with similar calculated sensitivity indices (1.5, 90%CI: 0.7-2.9 vs 2.8, 90%CI: 1.9-5.1). The reduction in voluntary activation was more pronounced (P=0.019) in open- (-6.8±8.3%) than in closed-loop exercises (-1.9±4.4%), but there was no difference between open- and closed-loop exercises for the potentiated twitch force reduction (-25.6±12.8 vs -26.6±12.0%, P>0.05). Caffeine had no effect on central and peripheral fatigue development in either mode of exercise. In conclusion, caffeine improved endurance performance in both modes of exercise without influence on post-exercise central and peripheral fatigue, with the open-loop exercise imposing a greater challenge to central fatigue tolerance.

Association between anaerobic components of the maximal accumulated oxygen deficit and 30-second Wingate test

The purpose of this study was to analyze the relationship between the anaerobic components of the maximal accumulated oxygen deficit (MAOD) and of the 30-second Wingate anaerobic test (30-WAnT). Nine male physical education students performed: a) a maximal incremental exercise test; b) a supramaximal constant workload test to determine the anaerobic components of the MAOD; and c) a 30-WAnT to measure the peak power (PP) and mean power (MP). The fast component of the excess post-exercise oxygen consumption and blood lactate accumulation were measured after the supramaximal constant workload test in order to determine the contributions made by alactic (ALMET) and lactic (LAMET) metabolism. Significant correlations were found between PP and ALMET (r=0.71; P=0.033) and between MP and LAMET (r=0.72; P=0.030). The study results suggested that the anaerobic components of the MAOD and of the 30-WAnT are similarly applicable in the assessment of ALMET and LAMET during high-intensity exercise.

Reduced expressions of Fas and Bcl-2 proteins in CD14+ monocytes and normal CD14 soluble levels in juvenile systemic lupus erythematosus.

In order to evaluate Fas and Bcl-2 expressions in CD14+ monocytes, to measure soluble CD14 serum levels and to analyze the relationships with lupus nephritis and disease activity, we enrolled 41 patients with juvenile systemic lupus erythematosus (JSLE) and 27 healthy volunteers. Disease activity was determined by SLEDAI score. Peripheral monocytes were stained for CD14, Fas and Bcl-2 molecules, and cellular expressions were determined by flow cytometry. Soluble CD14 levels were measured by a quantitative ELISA kit. JSLE patients, those with active disease and those with nephritis, presented significantly reduced expressions of Fas and Bcl-2 proteins in CD14+ monocytes compared with healthy controls. Significant inverse correlations between percentages of CD14+Fas+ cells, SLEDAI score and anti-dsDNA antibodies were observed. JSLE patients had soluble CD14 levels similar to controls, although sCD14 levels positively correlated with ESR, but not with SLEDAI score. JSLE patients with nephritis also presented sCD14 levels similar to controls. In conclusion, the reduced expressions of Fas and Bcl-2 proteins in CD14+ monocytes from JSLE patients depict that monocyte apoptotic mechanisms may be important in lupus pathogenesis.

MHC class I and II expression in juvenile dermatomyositis skeletal muscle.

OBJECTIVE: To assess MHC I and II expressions in muscle fibres of juvenile dermatomyositis (JDM) and compare with the expression in polymyositis (PM), dermatomyositis (DM) and dystrophy. PATIENTS AND METHODS: Forty-eight JDM patients and 17 controls (8 PM, 5 DM and 4 dystrophy) were studied. The mean age at disease onset was 7.1+/-3.0 years and the mean duration of weakness before biopsy was 9.4+/-12.9 months. Routinehistochemistry and immunohistochemistry (StreptABComplex/HRP) for MHC I and II (Dakopatts) were performed on serial frozen muscle sections in all patients. Mann-Whitney, Kruskal Wallis, chi-square and Fisher's exact statistical methods were used. RESULTS: MHC I expression was positive in 47 (97.9%) JDM cases. This expression was observed independent of time of disease, corticotherapy previous to muscle biopsy and to the grading of inflammation observed in clinical, laboratorial and histological parameters. The expression of MHC I was similar on JDM, PM and DM, and lower in dystrophy. On the other hand, MHC II expression was positive in just 28.2% of JDM cases and was correlated to histological features as inflammatory infiltrate, increased connective tissue and VAS for global degree of abnormality (p<0.05). MHC II expression was similar in DM/PM and lower in JDM and dystrophy, and it was based on the frequency of positive staining rather than to the degree of the MCH II expression. CONCLUSIONS: MHC I expression in muscle fibres is a premature and late marker of JDM patient independent to corticotherapy, and MHC II expression was lower in JDM than in PM and DM.

Detection of Merkel cell polyomavirus DNA in Merkel cell carcinomas.

BACKGROUND: Merkel cell carcinoma (MCC) is a rare, aggressive tumour for which an increasing incidence has been reported. A new human polyomavirus, Merkel cell polyomavirus (MCV), was recently isolated from these tumours by applying digital transcriptome subtraction methodology. OBJECTIVES: To detect the presence or absence of MCV in MCCs and other, randomly selected neoplasms. METHODS: Nine primary or recurrent MCCs from seven patients were examined; 29 other tumours (squamous cell, basal cell and basosquamous carcinomas and malignant melanomas) were examined for comparative purposes. Viral large T protein (LT1 and LT3), and viral capsid protein (VP1) were detected by primer-directed amplification, using a polymerase chain reaction (PCR)-based method, and the amplified PCR products were analysed by agarose gel electrophoresis and subsequent sequence analysis. RESULTS: The presence of viral T antigen and/or viral capsid DNA sequences was demonstrated in seven of the eight MCC lesions. None of the comparative samples contained MCV DNA. CONCLUSIONS: Our findings strongly support the hypothesis that MCV infection may well be specific for MCC, and MCV may play a role in the pathogenesis of MCC.

HLA-DRB1 alleles in juvenile-onset systemic lupus erythematosus: renal histologic class correlations

Human leukocyte antigens (HLA) DRB1*03 and DRB1*02 have been associated with systemic lupus erythematosus (SLE) in Caucasians and black populations. It has been observed that certain HLA alleles show stronger associations with SLE autoantibodies and clinical subsets, although they have rarely been associated with lupus renal histologic class. In the present study, HLA-DRB1 allele correlations with clinical features, autoantibodies and renal histologic class were analyzed in a cohort of racially mixed Brazilian patients with juvenile-onset SLE. HLA-DRB1 typing was carried out by polymerase chain reaction amplification with sequence-specific primers using genomic DNA from 55 children and adolescents fulfilling at least four of the American College of Rheumatology criteria for SLE. Significance was determined by the chi-square test applied to 2 x 2 tables. The HLA-DRB1*15 allele was most frequent in patients with renal, musculoskeletal, cutaneous, hematologic, cardiac, and neuropsychiatric involvement, as well as in patients positive for anti-dsDNA, anti-Sm, anti-U1-RNP, and anti-SSA/Ro antibodies, although an association between HLA alleles and SLE clinical features and autoantibodies could not be observed. The HLA-DRB1*17, HLA-DRB1*10, HLA-DRB1*15, and HLA-DRB1*07 alleles were significantly higher in patients with renal histologic class I, class IIA, class IIB, and class V, respectively. The present results suggest that the contribution of HLA- DRB1 alleles to juvenile-onset SLE could not be related to clinical or serological subsets of the disease, but it may be related to renal histologic classes, especially class I, class II A, class II B, and class V. The latter correlations have not been observed in literature.

Rituximab in refractory autoimmune diseases: Brazilian experience with 29 patients (2002-2004).

OBJECTIVE: Rituximab, a monoclonal antibody against B-lymphocytes that express CD 20, is already available for the treatment of non-Hodgkin's lymphoma. Due to the increased relevance of B-cell regulation in the pathogenesis of autoimmune diseases, rituximab is being used in the treatment of patients whose condition is refractory to conventional therapy. METHODS: We retrospectively evaluated the short-term efficacy and tolerance of rituximab in patients with various autoimmune diseases who were treated at the Hospital Israelita Albert Einstein in the city of Sao Paulo. RESULTS: During the period 2002-2004, 29 patients with various autoimmune diseases were treated with rituximab 375 mg/m2 for 4 consecutive weeks, or two doses of 1 g 2 weeks apart. We observed remarkable short-term results in all cases, except for one patient with thrombocytopenic purpura. Of note, we describe the results in two patients with diseases not previously treated with rituximab (hypergammaglobulinemic purpura of Waldenstrom and eosinophilic fasciitis with hypergammaglobulinemia). Treatment was well tolerated, with no unexpected adverse events. We also observed a marked reduction in steroid dosage. CONCLUSION: Rituximab seems to be safe and effective in the treatment of patients with a variety of autoimmune diseases that are refractory to other modalities of treatment.

[Quality of life evaluation in children and adolescents with chronic and/or incapacitating diseases: a Brazilian study]. / Evaluación de la calidad de vida en niños y adolescentes portadores de enfermedades crónicas y/o incapacitadoras: un estudio brasileño.

OBJECTIVE: To evaluate quality of life in children and adolescents with acute lymphocytic leukemia (ALL) and juvenile rheumatoid arthritis (JRA). MATERIAL AND METHODS: We administered the Children's Global Assessment Scale (CGAS), the Vineland Adaptative Behavior Scale (VABS) and the Autoquestionnaire qualité de vie enfant imagé (AUQEI) to a sample of 28 children with ALL, 28 children with JRA, and 28 healthy controls, aged 4 to 13 years old, who were diagnosed between 1 and 5 years previously. RESULTS: Slight differences were found in age between patients with ALL and those with JRA. No significant differences were found in time since diagnosis or in CGAS scores. A significant difference was found in VABS global scores, as well as in VABS communication domain scores. No significant differences were found in VABS daily living skills domain scores between patients with ARJ and healthy controls. No significant differences were found among the groups in VABS socialization domain scores or in AUQEI scores. CONCLUSION: In our study, chronically ill children clearly performed worse in adaptative behavior development. Nevertheless, their quality of life was similar to that of healthy controls. Appropriate methods to identify pediatric patients' perception of their illnesses and treatment should be urgently developed.

[Takayasu's arteritis]. / Arteritis de Takayasu.

BACKGROUND: Takayasu's arteritis is a rare vasculitis in the pediatric population that affects the aorta and its branches. There are few studies with an appropriate number of patients and follow-up. OBJECTIVE: To describe the clinical manifestations, laboratory alterations, radiological findings, and treatment in eight children and adolescents with Takayasu's arteritis. METHODS: A retrospective analysis of patients' records from 1990 to 2001 was performed. RESULTS: There were six girls and two boys. The mean age at disease onset was five years and five months. The most common clinical manifestations were systemic findings and cardiovascular, dermatological and neurological abnormalities. In all patients inflammatory activity was high and in three patients the Mantoux test was strongly positive. The most common radiological findings were type IV and V. Treatment included steroids, methotrexate, cyclophosphamide, intravenous gamma globulin, and vascular surgery. Three patients presented sequelae. CONCLUSIONS: Takayasu's arteritis produces considerable morbidity and mortality. To make an early diagnosis, pediatricians should be aware of inflammatory systemic manifestations and cardiovascular abnormalities. To gain further knowledge of this entity prospective and ideally multicenter studies are required.

T-cell reactivity against streptococcal antigens in the periphery mirrors reactivity of heart-infiltrating T lymphocytes in rheumatic heart disease patients.

T-cell molecular mimicry between streptococcal and heart proteins has been proposed as the triggering factor leading to autoimmunity in rheumatic heart disease (RHD). We searched for immunodominant T-cell M5 epitopes among RHD patients with defined clinical outcomes and compared the T-cell reactivities of peripheral blood and intralesional T cells from patients with severe RHD. The role of HLA class II molecules in the presentation of M5 peptides was also evaluated. We studied the T-cell reactivity against M5 peptides and heart proteins on peripheral blood mononuclear cells (PBMC) from 74 RHD patients grouped according to the severity of disease, along with intralesional and peripheral T-cell clones from RHD patients. Peptides encompassing residues 1 to 25, 81 to 103, 125 to 139, and 163 to 177 were more frequently recognized by PBMC from RHD patients than by those from controls. The M5 peptide encompassing residues 81 to 96 [M5(81-96) peptide] was most frequently recognized by PBMC from HLA-DR7+ DR53+ patients with severe RHD, and 46.9% (15 of 32) and 43% (3 of 7) of heart-infiltrating and PBMC-derived peptide-reactive T-cell clones, respectively, recognized the M5(81-103) region. Heart proteins were recognized more frequently by PBMC from patients with severe RHD than by those from patients with mild RHD. The similar pattern of T-cell reactivity found with both peripheral blood and heart-infiltrating T cells is consistent with the migration of M-protein-sensitized T cells to the heart tissue. Conversely, the presence of heart-reactive T cells in the PBMC of patients with severe RHD also suggests a spillover of sensitized T cells from the heart lesion.

Human breast cancer specimens: diffraction-enhanced imaging with histologic correlation--improved conspicuity of lesion detail compared with digital radiography.

Seven breast cancer specimens were examined with diffraction-enhanced imaging at 18 keV with a silicon crystal with use of the silicon 333 reflection in Bragg mode. Images were compared with digital radiographs of the specimen, and regions of increased detail were identified. Six of the seven cases (86%) showed enhanced visibility of surface spiculation that correlated with histopathologic information, including extension of tumor into surrounding tissue.

The place of magnetic resonance and ultrasonographic examinations of the parotid gland in the diagnosis and follow-up of primary Sjögren's syndrome.

OBJECTIVE: The aim was to determine the place of magnetic resonance imaging (MRI) and ultrasonographic (US) examination in the diagnosis and follow-up of Sjögren's syndrome (SS). METHODS: Parotid MRI and US examinations were carried out on 44 primary SS patients and 52 controls of similar age. RESULTS: The most important structural changes in SS were different degrees of parenchymal inhomogeneity, which could be detected by both methods, and were found more frequently in the SS patients than in the controls (MRI: 95.4 vs 17. 3%; US: 88.6 vs 7.7%; P<0.001). There was good agreement between the MRI and US findings both in the SS cases (93.2%) and in the controls (86.5%). In one SS patient who developed parotid lymphoma, the US examination showed a hypoechoic 'cobblestones'-like inhomogeneous internal pattern which was coupled with an almost homogeneous MRI pattern. CONCLUSIONS: MRI appears unnecessary as a routine method in the diagnosis of SS; US examination is suitable both for the diagnosis and follow-up of SS. The above combination of the seemingly contradictory US and MRI findings is highly characteristic of lymphoma which has developed in the course of the disease.

Posterior circulation aneurysms. Technical strategies based on angiographic anatomical findings and the results of 60 recent consecutive cases.

Ninety-eight patients with aneurysms of the posterior circulation were admitted to our department from 1993 to 1997. Sixty of them underwent microsurgical treatment, mostly in the acute stage of subarachnoid hemorrhage. Peri- and intraoperative management were carried out according to a structured treatment strategy. Special aspects of surgical technique included extradural selective anterior clinoidectomy for basilar head aneurysms, lateral suboccipital craniotomy and partial condylectomy without laminectomy for aneurysms of the vertebral artery or posterior inferior cerebellar artery, and a trans-Sylvian approach, as used in selective amygdalohippocampectomy, for aneurysms of the posterior cerebral artery. A careful angiographic evaluation of the aneurysms in relation to the neighboring important arteries and bony structures was essential for optimal surgical planning. Forty-nine patients (82%) made a good recovery by 3 months after surgery. The mortality was 7%.

Chest tube insertion: a prospective evaluation of pain management.

OBJECTIVE: To evaluate pain associated with chest tube insertion in a group of patients with malignant pleural effusions. DESIGN: Prospective case series. SETTING: Acute care cancer center in an academic institution. PATIENTS: Fifty-two patients with symptomatic malignant pleural effusions. Twenty-six evaluated by conventional approach to chest tube insertion (group 1), 26 evaluated after institution of a new chest tube protocol (group 2). INTERVENTIONS: A new protocol was designed to improve pain control during chest tube insertion. The protocol included improved housestaff and nursing education, premedication, proper insertion techniques, and more liberal and precise delivery of local anesthetic. OUTCOME MEASURES: Both groups were evaluated by a verbal self-report scale (1-10) to assess pain and anxiety. RESULTS: The mean pain rating in group 1 was 6.2 (+/-0.76) compared with 3.7 (+/-5.6) in group 2 (p < 0.01). In group 1, pain or anxiety was 9 or 10 in 12 of 26 on a scale of 1 to 10, compared with 2 of 26 in group 2 (p < 0.001). Anxiety rating was 4.5 (+/-0.72) in group 1 compared with 1.5 (+/-0.54) in group 2 (p < 0.01). CONCLUSIONS: Chest tube insertion was associated with an unacceptably high level of pain and anxiety in our hospital. A new protocol, including housestaff education and changes in nursing policies, technical aspects, local anesthetic dose and delivery, and pre-medication, allowed us to approach the goal of a painless chest tube insertion.

Pyodermatitis-pyostomatitis vegetans.

A 43-year-old woman developed annular and pustular cutaneous lesions preceded by tiny yellow pustules coating the surface of the oral mucosa. The clinical, histological and immunopathological evidence clearly showed that the patient had pyodermatitis-pyostomatitis vegetans. It is suggested that this disease is a distinct entity which should be differentiated from pemphigus vegetans.

Kaposi's sarcoma-associated herpesvirus/human herpesvirus-8: a new virus in human pathology.

The discovery of a new human herpesvirus in Kaposi's sarcoma (KS) tissue of patients with AIDS has opened up new vistas in virology and oncology. This herpesvirus was first descriptively named KS-associated herpesvirus (KSHV), but was recently renamed human herpesvirus 8 (HHV8). KSHV/HHV8 DNA has been found in all forms of KS, suggesting that it might be involved in the pathogenesis of KS. In addition, KSHV/HHV8 can be detected in both malignant and benign lymphoproliferative disease. KSHV/HHV8 was also found in patients with angiosarcoma of the face and angiolymphoid hyperplasia with eosinophilia. Although only a limited portion of the virus has been sequenced, KSHV/HHV8 is equipped with genes that could confer oncogenic potential. The virus can now be cultured, providing the possibility for studies of viral replication and the mode of transmission. The recently developed serologic assays for antiviral antibodies suggest that infection with KSHV/HHV8 is not ubiquitous because KSHV/HHV8 seropositivity is limited to a small proportion of the population.

[Kaposi sarcoma-associated herpesvirus; human herpesvirus 8]. / Kaposi-sarcomához asszociált herpesvirus: human herpesvirus 8.

The discovery of a new human herpesvirus in Kaposi's sarcoma tissues of AIDS patients has opened up new facts in virology and oncology. This herpesvirus was first descriptively named Kaposi's sarcoma-associated herpesvirus, but was recently renamed human herpesvirus 8. Human herpesvirus 8 DNA has been consequently found in all forms of Kaposi's sarcoma, suggesting that it might be involved in the pathogenesis of the disease. Additionally, human herpesvirus 8 can be detected in both malignant and benign lymphoproliferative diseases, such as body-cavity-based B-cell lymphomas and multicentric Castleman disease. The virus was also recently found in rare vascular tumors in patients with angiosarcoma of the face and angiolymphoid hyperplasia with eosinophilia. Although only a limited portion of the viral DNA has been sequenced, it has become evident that the new herpesvirus is equipped with genes that could confer oncogenic potential. The virus can now be cultured, providing the possibility for studies of viral replication and the mode of transmission, and also for the development of serologic tests.

Implementing national standards for cancer pain management: program model and evaluation.

The purpose of this quasi-experimental (pre and posttest) study was to test a model pain management program (PMP) to implement the American Pain Society (APS) quality assurance standards for the management of acute and chronic cancer pain using a continuous quality improvement (CQI) approach to improve professionals' knowledge and skills, patient satisfaction, and to identify areas needing improvement. The sample consisted of 1210 nurse responses and 698 interviews of patients with pain during hospitalization at a major urban cancer center. The PMP provided a structure (standards), educational opportunities, and training in CQI methods. Outcome measures included a patient evaluation questionnaire and concerns checklist; nurse knowledge, attitude and barriers questionnaire; and focus groups to identify areas needing improvement. Significant improvements were found in patients' satisfaction, nurses' knowledge and attitude scores, and reductions in nurses' perceptions of barriers. Focus groups revealed the need for improved communication among disciplines about pain and better assessment of patients unable to self-report. The program met its goal of implementing the APS standards, educating nurses, and identifying "system" problems, and improving overall patient satisfaction.