Quality of scientific articles

The paper discusses the difficulties in judging the quality of scientific manuscripts and describes some common pitfalls that should be avoided when preparing a paper for submission to a peer-reviewed journal. Peer review is an imperfect system, with less than optimal reliability and uncertain validity. However, as it is likely that it will remain as the principal process of screening papers for publication, authors should avoid some common mistakes when preparing a report based on empirical findings of human research. Among these are: excessively long abstracts, extensive use of abbreviations, failure to report results of parsimonious data analyses, and misinterpretation of statistical associations identified in observational studies as causal. Another common problem in many manuscripts is their excessive length, which makes them more difficult to be evaluated or read by the intended readers, if published. The evaluation of papers after their publication with a view towards their inclusion in a systematic review is also discussed. The limitations of the impact factor as a criterion to judge the quality of a paper are reviewed.

Tuberculosis in renal transplant patients

Tuberculosis (TB) was diagnosed in 25 of 466 patients who underwent renal transplant over a period of 15 years. TB developed from 1 month to 9 years post-transplant. In 56% of the cases the onset was within the first post-transplant year. TB affected several isolated or combined organs. Pulmonary involvement was present in 76% of cases, either as isolated pleuro-pulmonary (56%) or associated with other sites (20%). The non-pulmonary sites were: skin, joints, tests, urinary tract, central nervous system and lymphonodules. The diagnosis was confirmed by biopsy in 64% of the cases, by identification of tubercle bacilli in 24% and only at necropsy in 12% Biopsy specimens could be classified in three histological forms: exudative, that occurred in early onset and more severe cases granulomatous in late onset and benign cases; and mixed in intermediate cases. Azathioprine dosages were similar along post-transplant time periods in TB patients and in the control groups; and in TB patients who were cured and who died. The number of steroid treated rejection crises was greater in TB than in the control group. Prednisone doses were higher and the number of rejection crises was greater in TB patients who died than in those who were cured. Fifteen patients were cured and ten died, two of them of causes unrelated to TB. Six of the eight TB-related deaths occurred in the first 6 post-transplant months. The outcome was poor in patients in whom TB arose early in post-transplant period and where the exudative or mixed forms were present; whereas the prognosis was good in patients with late onset and granulomatous form of TB. In one patient TB was transmitted by the allograft.

The use of cyclosporine modifies the clinical and histopathological presentation of tuberculosis after renal transplantation

Tuberculosis is one of the most frequent opportunistic infections after renal transplantation and occurred in 30 of 1264 patients transplanted between 1976 and 1996 at Hospital São Paulo - UNIFESP and Hospital Dom Silvério, Brazil. The incidence of 2.4% is five times higher than the Brazilian general population. The disease occurred between 50 days to 18 years after the transplant, and had an earlier and worse development in patients receiving azathioprine, prednisone and cyclosporine, with 35% presenting as a disseminated disease, while all patients receiving azathioprine and prednisone had exclusively pulmonary disease. Ninety percent of those patients had fever as the major initial clinical manifestation. Diagnosis was made by biopsy of the lesion (50%), positivity to M. tuberculosis in the sputum (30%) and spinal cerebral fluid analysis (7%). Duration of treatment ranged from 6 to 13 months and hepatotoxicity occurred in 3 patients. The patients who died had a significant greater number of rejection episodes and received higher doses of corticosteroid. In conclusion, the administration of cyclosporine changed the clinical and histopathological pattern of tuberculosis occurring after renal transplantation.

The biological meaning of anti-HBC positive result in blood donors: relation to HBV-DNA and to other serological markers

In order to assess the potential risk of anti-HBc-positive blood donors for post-transfusional hepatitis and to investigate whether other HBV serological markers are capable of identifying the presence of the virus, 1000 first-time blood donors were enrolled between June and July 1997. These donors were screened using routine Brazilian blood center tests (HIV 1 and 2, HTLV 1 and 2, Chagas disease, Syphilis, HCV, HBsAg, anti-HBc and ALT ). The 120 (12%) found to be anti-HBc-positive underwent further tests: HBe, anti-HBe, anti-HBs and HBV-DNA by PCR. Ten cases were HBsAg positive and all were HBV-DNA positive by PCR. Three HBsAg-negative donors were HBV-DNA-positive. Two HBV-DNA-positive donors were also anti-HBs-positive. All the HBV-positive donors had at least one HBV marker other than anti-HBc. Anti-HBc is an important cause of blood rejection. Testing for HBsAg alone is not fully protective and anti-HBc remains necessary as a screening test. The presence of anti-HBs is not always indicative of absence of the virus. The addition of other HBV serological markers could represent an alternative in predicting the presence of the virus when compared with PCR. It is recommended that other studies should be carried out to confirm this finding.

Cryptococcal meningitis in HIV negative pregnant women: case report and review of literature

INTRODUCTION: Cryptococcosis has become an important entity due to the epidemic of AIDS and therefore it is a significant opportunistic infection. However, there are case reports of cryptococcal meningitis in immune competent pregnant women. Since pregnancy is considered a period of relative immunosuppression, which likely prevents fetal rejection, this could explain the occurrence of opportunistic infections. OBJECTIVE: To report a case of cryptococcosis, and review all cases involving pregnancy and neurocryptococcal infection in immune competent pregnant patients. METHODS: Case report and systematic review of the literature using the MEDLINE and SciELO databases. DISCUSSION: A total of 27 patients were analyzed from 19 studies. The mean age at diagnosis was 26.4 years. There were six patients in their first trimester of pregnancy, 10 in the second, eight in the third and three post-partum. The most prevalent symptoms were headache (85.2%), altered vision (44.4%), altered mental status (44.4%), nausea (40.7%) and fever (33.3%). There were nine deaths (33.3%). Most of the patients received intravenous amphotericin B as treatment (77.8%). The majority (66.6%) of the patients accomplished a term delivery with healthy infants. CONCLUSION: Cryptococcal meningitis should be considered during pregnancy in cases of unexplained headache, altered vision, altered mental status, nausea and fever. Patients with a confirmed diagnosis should be admitted and treated with amphotericin B.

Clinical and epidemiological profile of blood donors with positive serology for viral hepatitis in southern Brazil

INTRODUCTION: Positive serological tests for hepatitis viruses B and C at blood banks are an important reason for blood deferral. Additionally, high residual risk for transfusing hepatitis-contaminated blood has been estimated in southern Brazil. This study aimed to identify risk factors for positive serological tests for viral hepatitis (VH) in blood donors (BD). METHODS: A case-control study included consecutive BD with positive serology for VH, between 2008 and 2009. Cases and controls (BD with negative serology for VH) were paired 1:1 by sex and donation date. Assessment of clinical and epidemiological characteristics related to viral hepatitis was conducted. RESULTS: Among 1,282 blood donors (641 cases and 641 controls), those with positive serology for viral hepatitis had higher mean age (p<0.001); higher proportion of replacement donation (p<0.001); first donation (p<0.001); and interviewer deferment (p=0.037), compared to controls. Furthermore, donors with positive tests were less regular donors (p<0.001), had less previous history of rejection (p=0.003) and showed lower hematocrit median before donation (p=0.019). Multivariate analysis demonstrated that age (OR=1.056, 95%CI 1.042-1.069, p<0.001), replacement donation (OR=1.545, 95%CI 1.171-2.038, p=0.002) and first donation (OR=9.931, 95%CI 7.486-13.173, p<0.001) were independently associated with positivity of serological tests for viral hepatitis. CONCLUSIONS: Specific characteristics of blood donors were associated with positive serology for viral hepatitis. These peculiarities should be taken into account when assessing candidates for blood donation.

Hormone replacement therapy and the risk of breast cancer: assessment of therapy acceptance in a cohort of previously treated breast cancer patients

INTRODUCTION: In the postmenopausal period, an average of 25% of women will present symptomatic ovarian failure requiring hormonal replacement therapy. Estrogen can relieve vasomotor symptoms. Hormonal replacement therapy is generally not recommended for breast cancer patients due to the potential risk of tumor recurrence. To answer the questions about the safety of hormonal replacement therapy in this subgroup of women, it is necessary to establish the acceptance of treatment. METHODS: Between September 1998 and February 2001, a cohort of 216 breast cancer patients were asked to complete a questionnaire. All patients had completed their treatment and were informed about survival rates after breast cancer and hormonal replacement therapy. RESULTS: Among the 216 patients, 134 (62%) would refuse hormonal replacement therapy. A hundred patients were afraid of relapse (74.6%). Adjuvant tamoxifen therapy was the only statistically significant variable (70.3% versus 29.7% p=0.003). Understanding clinical stage (p= 0.045) and type of medical assistance (private versus public , p=0.033) also seemed to influence the decision. Early stage disease (p= 0.22), type of surgical procedure (radical versus conservative, p=0.67), adjuvant chemotherapy (p=0.082) or marital status (p=0.98 ) were not statistically significant in decision making. Several patients submitted to adjuvant chemotherapy (41.6%) would accept hormonal replacement therapy under medical supervision, as did most of advanced clinical stage patients (58.3%; p=0.022). CONCLUSION: There is a high level of rejection for hormonal replacement therapy among breast cancer patients when current data on tumor cure rates, and potential risks of estrogen use is available. Adverse effects of tamoxifen in the adjuvant setting may be the reason for refusal of hormonal replacement therapy .

Permanent and temporary pacemaker implantation after orthotopic heart transplantation

PURPOSE:To determine the indication for and incidence and evolution of temporary and permanent pacemaker implantation in cardiac transplant recipients. METHODS: A retrospective review of 114 patients who underwent orthotopic heart transplantation InCor (Heart Institute USP BR) between March 1985 and May 1993. We studied the incidence of and indication for temporary pacing, the relationship between pacing and rejection, the need for pemanent pacing and the clinical follow-up. RESULTS: Fourteen of 114 (12%)heart transplant recipients required temporary pacing and 4 of 114 (3.5%) patients required permanent pacing. The indication for temporary pacing was sinus node dysfunction in 11 patients (78.5%) and atrioventricular (AV) block in 3 patients (21.4%). The indication for permanent pacemaker implantation was sinus node dysfunction in 3 patients (75%) and atrioventricular (AV) block in 1 patient (25%). We observed rejection in 3 patients (21.4%) who required temporary pacing and in 2 patients (50%) who required permanent pacing. The previous use of amiodarone was observed in 10 patients (71.4%) with temporary pacing. Seven of the 14 patients (50%) died during follow-up. CONCLUSION: Sinus node dysfunction was the principal indication for temporary and permanent pacemaker implantation in cardiac transplant recipients. The need for pacing was related to worse prognosis after cardiac transplantation.

Heart transplantation in neonates and children. Intermediate-term results

OBJECTIVE: To assess intermediate-term outcome in children who have undergone orthotopic heart transplantation. METHODS: We carried out a longitudinal and prospective study between October '92 and June '99 comprising 20 patients with ages ranging from 12 days to 7 years (mean of 2.8 years). We employed a double immunosuppression protocol with cyclosporine and azathioprine and induction therapy with polyclonal antithymocyte serum. Survival and complications resulting from the immunosuppression protocol were analyzed. RESULTS:The double immunosuppression protocol and the induction therapy with polyclonal antithymocyte serum resulted in an actuarial survival curve of 90% and 78.2% at 1 and 6 years, respectively, with a mean follow-up period of 3.6 years. One patient died due to acute rejection 40 days after transplantation; another patient died 2 years after transplantation due to lymphoproliferative disorder; a third patient died because of primary failure of the graft; and a fourth patient died due to bronchopneumonia. The major complications were as follows: acute rejection, infection, nephrotoxicity, and systemic hypertension. The means of rejection and infection episodes per patient were 2.9 and 3.4, respectively. After one year of transplantation, a slight reduction in the creatinine clearance and systemic hypertension were observed in 7 (38.9%) patients. CONCLUSION: Heart transplantation made life possible for those patients with complex congenital heart diseases and cardiomyopathies in refractory congestive heart failure constituting a therapeutical option for this group of patients in the terminal phase.

Analysis of the risk factors for allograft vasculopathy in asymptomatic patients after cardiac transplantation

OBJECTIVE: To study the influence of immune and nonimmune risk factors on the development of allograft vasculopathy after cardiac transplantation. METHODS: We studied 39 patients with a mean age of 46±12 years. The following variables were analyzed: weight (kg), body mass index (kg/m²), donor's age and sex, rejection episodes in the first and second years after transplantation, systolic and diastolic blood pressures (mmHg), total cholesterol and fractions (mg/dL), triglycerides (mg/dL), diabetes, and cytomegalovirus infection. The presence of allograft vasculopathy was established through coronary angiography. RESULTS: Allograft vasculopathy was observed in 15 (38%) patients. No statistically significant difference was observed between the two groups in regard to hypertension, cytomegalovirus infection, diabetes, donor's sex and age, rejection episodes in the first and second years after transplantation, and cholesterol levels. We observed a tendency toward higher levels of triglycerides in the group with disease. Univariate and multivariate analyses showed statistically significant differences between the two groups when we analyzed the body mass index (24.53±4.3 versus 28.11±4.6; p=0.019). CONCLUSION: Body mass index was an important marker of allograft vasculopathy in the population studied.

Morphology and dynamics of male gametogenesis in Sympterygia bonapartii (Chondrichthyes, Rajidae) from Northern Patagonia

ABSTRACT The smallnose fanskate, Sympterygia bonapartii Müller & Henle, 1841 is one of the most disembarked items in commercial harbors in Argentina. In this work, the microscopic architecture of mature male gonads and the dynamics of cysts development are analyzed as a contribution to awareness of the reproductive biology of the species. Some biological data related to reproduction are given as well. Two seasons were sampled (fall and spring) and length classes's frequency distribution and maturity stages frequency distribution are given. Size at first sexual maturation for males was estimated at 57 cm of total length. Testes are symmetric, peer, lobed, with several germinal zones. Inside the gonads, there are many spermatocysts, containing reproductive cells at the same developmental stage. On the basis of their cytological and microanatomical features, several maturative degrees of the spermatogenic series were differentiated. Few Leydig cells were recognized at the interstitial tissue among cysts. The microscopic and semiquantitative analysis performed in this work provides morphological information about male gametogenesis and some biological data for the North Patagonian population of this economically and ecologically important species.

Chagas' disease: selective affinity and cytotoxicity of Trypanosoma cruzi-immune lymphocytes to parasympathetic ganglion cells

The megaesophagus and megacolon endemic in South America are related , to Chagas' disease. These mega conditions are found in patients with chronic Chagas's infection, when the parasite is not demonstrable in the lesions. These are characterized by depopulation of parasympathetic ganglion cells, dilation and hypertrophy of the viscera. In the experiments described here we deminstrate a selective affinity and adherence of Trypanosoma cruzi-immune lymphocytes to myenteric, parasympathetic ganglion cells, leading to neuronolysis. None of these features are observed when non-immune lymphocytes from control rabbits are used, or when the immune lymphocytes are allowed to react with CNS neurons. This demonstration is an indication of the high degree of specificity of the destruction of parasympathetic neurons in Chagas' disease. We postulate that the T. cruzi-immune lymphocyte rejection of parasympathetic neurons, but not of CNS neurons, might be related to recognition of a cross-reacting antigenic determinant secreted only by the target neurons. In favor of this interpretation is the observation of lymphocytic infiltrates and parasympathetic ganglion cell destruction in chronic Chagas' infection in the absence of encephalitis.

Prevention of bone marrow graft failure by an anti LFA-1 monoclonal antibody

Graft rejection is the major cause of failure of HLA mismatched bone marrow transplantation because of residual host immunity. we have proposed to use a monoclonal murine antibody specific for the LFA-1 molecule (25-3) to prevent graft failure in HLA mismatched bone marrow transplantation (BMT). The rationale for this approach is three fold: LFA-1 deficient patients (3/3) do not reject HLA mismatched BMT; anti LFA-1 blocka in vitro the induction of T cell responses and T/ non T cytotoxic functions; LFA-1 is not expressed by other cells than leucocytes. We have accordingly treated twenty two patients with inherited diseases and 8 with leikemia. The bone marrow was T cells depled by E rosetting of Campath antibody. The antibody was given at days -3, -1, +1, +3, +5 at dose of .1 mg/kg/d for the first 9 and then .2mg/kg/d from day -3 to +6. Engraftment occured in 23/30 patients as shown by at least HLA typing. Hematological recovery was rapid, GVH was limited. Side effects of antibody infusion included fever and possibly an increased incidence of early bacteral infection (sepsis, 1 death). Immunological reconstitution occured slowly leading in six cases to EBV-induced B cell poliferation (1 death and in two others to transient auto immune hemolytic anemia. There has been only one secondary graft rejection. Sisteen patients are alive 3 to 26 months post transplant with functional grafts. Although the number of patients treated is still low the absence of late rejection so far, gives hope for long term maintenance of the graft using anti LFA-1. Since the antibody is an IgG 1 unable to bind human complement, and since it is known to inhibit phagocytosis, there is a good suggestion that 25-3 act through functional blocking of host T and non T luymphocytes at both induction and effector levels.

Sexual behaviour and stridulation during mating in Triatoma infestans (Hemiptera: Reduviidae)

Factors affecting mating behaviour in the bug Triatoma infestans were quantitatively studied in the laboratory. Experimental conditions were established so that the probability of copulation increased with the time elapsed since the first adult meal. Copulatory attempts by males did not vary as a function of time, but rejections by females became significantly less frequent with the post feeding time. Non-receptive females displayed four types of rejection behaviour, i.e. flattening, stridulation, evasion and abdominal movements. The occurrence of stridulation performed by females in a sexual context was observed in a regular fashion and was quantified for the first time in this species.

The noble enigma: Chagas' nominations for the Nobel Prize

Carlos Chagas, a Brazilian physician, discovered the American trypanosomiasis in 1909. Like other remarkable discoveries of those days, his work helped to articulate the insect-vector theory and other theoretical guidelines in tropical medicine. Unlike all other discoveries, all the stages of this work were accomplished in a few months and by a single man. Chagas' discovery was widely recognized at home and abroad. He was twice nominated for the Nobel Prize - in 1913 and in 1921-, but never received the award. Evidence suggests that the reasons for this failure are related to the violent opposition that Chagas faced in Brazil. The contentions towards Chagas were related to a rejection of the meritocratic procedures that gave him prominence, as well as to local petty politics.