Nickel Catalyzed Olefin Oligomerization and Dimerization.

Brought to life more than half a century ago and successfully applied for high-value petrochemical intermediates production, nickel-catalyzed olefin oligomerization is still a very dynamic topic, with many fundamental questions to address and industrial challenges to overcome. The unique and versatile reactivity of nickel enables the oligomerization of ethylene, propylene, and butenes into a wide range of oligomers that are highly sought-after in numerous fields to be controlled. Interestingly, both homogeneous and heterogeneous nickel catalysts have been scrutinized and employed to do this. This rare specificity encouraged us to interlink them in this review so as to open up opportunities for further catalyst development and innovation. An in-depth understanding of the reaction mechanisms in play is essential to being able to fine-tune the selectivity and achieve efficiency in the rational design of novel catalytic systems. This review thus provides a complete overview of the subject, compiling the main fundamental/industrial milestones and remaining challenges facing homogeneous/heterogeneous approaches as well as emerging catalytic concepts, with a focus on the last 10 years.

Prospective evaluation of rapid point-of-care tests for the diagnosis of acute leptospirosis in dogs.

The early diagnosis of acute leptospirosis is still a major challenge in dogs. The aim of this prospective study was to evaluate the suitability of two in-clinic tests detecting anti-leptospiral IgM and IgG antibodies in diagnosing canine leptospirosis. The performances of the two rapid tests were compared to the microscopic agglutination test (MAT) carried out on acute sera and to diagnostic criteria adopted in this study to confirm leptospirosis infection (MAT upon admission, convalescent MAT and quantitative real-time PCR on blood and/or urine). The dogs were enrolled on the basis of reported exposure to known risk factors and clinical presentation (acute kidney injury and/or systemic inflammatory response syndrome with multi-organ damage). Eighty-nine dogs included in the study were sub-grouped on the basis of the results of the diagnostic criteria adopted: (1) confirmed leptospirosis cases (42/89 dogs); (2) negative leptospirosis cases (36/89 dogs); and (3) unconfirmed leptospirosis cases (11/89 dogs). The results supported the usefulness of the two rapid diagnostic tests as a first in-clinic screening tool for suspected leptospirosis; positive results in the in-clinic tests in dogs with suggestive clinical and laboratory signs strongly indicated acute leptospirosis, while negative results required additional diagnostic investigation to exclude the infection. Confirmatory tests recommended for canine leptospirosis are still necessary in addition to the use of rapid in-clinic tests.

Prospective analysis between the therapy of immunosuppressive medication and allogeneic microchimerism after liver transplantation.

After liver transplantation, migration of donor-derived hematopoietic cells to recipient can be detected in peripheral blood. This state is termed microchimerism. The aim of this study was to investigate prospectively the presence of allogeneic microchimerism, the occurrence of acute cellular rejection and the level of immunosuppression in transplanted patients. Microchimerism occurrence between 10 days and 12 months after liver transplantation was analyzed in 47 patients aged between 15 and 65 by a two-stage nested PCR/SSP technique to detect donor MHC HLA-DR gene specifically. A pre-transplant blood sample was collected from each patient to serve as individual negative control. Microchimerism was demonstrated in 32 (68%) of the 47 patients; of these, only 10 patients (31.2%) presented rejection. Early microchimerism was observed in 25 patients (78.12%) and late microchimerism in 7 patients (21.8%). Among the patients with microchimerism, 14 were given CyA and 18 were given FK506. In the group without microchimerism, 12 patients were given CyA and 03 were given FK506. There was a significant association between the presence of microchimerism and the absence of rejection (p=0.02) and also between microchimerism and the type of immunosuppression used. Our data indicate that microchimerism and probably differentiation of donor-derived leukocytes can have relevant immunologic effects both in terms of sensitization of recipient and in terms of immunomodulation toward tolerance induction.

[Behavioral group-based therapy improves quality of life in men recovering from radical prostatectomy]. / Terapia grupal de comportamiento mejora la calidad de vida en hombres post prostatectomía radical.

BACKGROUND: This study evaluated the efficacy of 24-week, group-based, behavioral therapy in improving quality of life (QoL) among men treated for localized prostate carcinoma (PC) by means of radical prostatectomy (RP) who presented treatment-related dysfunctions: urinary incontinence (UI) and erectile dysfunction (ED). PATIENTS AND METHODS: Thirty men were assigned to 24-week behavioral group therapy. The intervention was designed to improve QoL by helping participants to identify and effectively manage stressful experiences. It focused on treatment-related sequelae from PC. Differences in variables were compared between the beginning and end of the study by means of Student's t test for paired samples. Multiple analysis was carried out by stepwise multiple linear regression following bivariate Pearson's correlation analysis. This was achieved for all predictors (i.e. general health perception, ED and UI impact) and relevant covariates (i.e. age, work/retirement status, alcohol addiction, attitude towards cancer and surgery, sexual satisfaction, and future plans). RESULTS: In all patients the time elapsed from surgery to attending the behavioral group therapy exceeded 24 months. There was no significant correlation between this time and the predictor variables. General health perception scores decreased by the end of the study (p = 0.000), as did the UI impact score (p = 0.023), thus denoting improvement in both factors. The difference in UI impact scores correlated negatively and significantly with both age (p = 0.04) and work/retirement (p = 0.05). Multiple stepwise regression showed that age was the most important variable (r2 = 26.0%). Considering age and work/retirement simultaneously, there was an increase of 10.3% (r2 = 36.3%). ED increased by the end of the study (p = 0.000), and the difference between the ED scores correlated positively and significantly with sexual satisfaction alone (p = 0.029), which signifies that previous sexual satisfaction had a positive influence over erectile dysfunction (r2 = 15.8%). CONCLUSION: 24-week behavioral group therapy was effective in improving the perceived QoL among men treated for PC. There were changes associated with the therapy, particularly the improvement in UI and ED.

Diagnostic value of combining immunostaining for CD3 and nuclear morphometry in mycosis fungoides.

BACKGROUND: Mycosis fungoides (MF) is the most common skin lymphoid neoplasm. In initial stages, differential diagnosis of MF from other benign dermal lymphoid infiltrates (BDLI) may be impossible on morphological basis alone. In previous studies, only deletion of CD7 in MF proved to be of diagnostic help, but not the ratio between immunoexpression of CD4 and CD8. METHODS: 30 cases of MF and 11 cases of BDLI were analysed, in order to compare morphometric parameters, which could be of diagnostic aid. As CD7 is frequently deleted in MF, immunohistochemical detection of T-cells was made using an antibody to CD3. Images of 100 CD3-positive cells per case in both groups were captured and analysed using a simple computer program for nuclear perimeter, area, diameter and nuclear contour index. RESULTS: All parameters showed statistically significant higher values for MF. Area was the variable with the strongest discriminating power between the two groups of patients. Thus even if morphological evaluation is not accurate to distinguish benign versus malignant dermal lymphoid infiltrates, due to the variability of size and shape of these cells, a more sensitive method promptly shows this difference. CONCLUSION: Results suggest that morphometry of CD3-positive lymphoid cells may add valuable information in the differential diagnosis of MF and benign dermatoses.

Allelic frequencies of the 35delG mutation of the GJB2 gene in different Brazilian regions.

Mutations in the GJB2 gene, which encodes the protein connexin 26, are a major cause of autosomal recessive deafness. The most frequent mutation, 35delG, has a carrier frequency as high as 4% in some countries, and this frequency varies in different ethnic groups. Most of the Brazilian population results from interethnic crosses of people from three continents (European, African, and Amerindian), and the proportion of each varies according to the geographical region of the country. To verify if the different ethnic composition of Brazilian regions leads to variable 35delG carrier frequencies, we performed the screening of the 35delG mutation using DNA from dried-blood filter paper samples obtained from 1,856 newborns from 10 cities in different regions. The 35delG mutation was found in 25 individuals (1.35%), indicating an overall carrier frequency of 1:74. This frequency was 1:47 in the north, 1:64 in the southeast, 1:85 in the south and 1:124 in the northeast, but these differences were not significant. The overall frequency of the 35delG allele was estimated as 0.0067, and comparison between expected and observed genotype frequencies indicates that the population is in Hardy-Weinberg equilibrium.

Molecular mechanisms associated with donor-specific microchimerism in peripheral blood of Brazilian patients after liver transplantation.

A large number of studies in liver transplantation have demonstrated allogeneic microchimerism. The clinical and immunologic implications of this finding remain inconclusive, just as the influence of HLA mismatch and donor alloreactivity also are controversial. The present study analyzed the presence of allogeneic microchimerism in liver transplant recipients in relation to donor leukocyte kinetics and rejection episodes. The study was extended to determining the influence of immunogenetic factors in patients after liver transplantation. The presence of allogeneic microchimerism was analyzed on peripheral blood of 50 recipients. DNA extracted from the samples was subjected to typing for HLA-DRB1 and -DQB1 alleles by polymerase chain reactions using sequence-specific primers (PCR/SSP). Microchimerism was identified by nested PCR/SSP. Microchimerism was detected in 72% of patients. There was significant effect of microchimerism on rejection episodes (P=.002), while HLA mismatches did not show significance for one or two mismatches (P=.98). Allogeneic microchimerism detected in the majority of liver transplant patients was observed to be significantly associated with rejection episodes.

Chronic GVHD in minor salivary glands and oral mucosa: histopathological and immunohistochemical evaluation of 25 patients.

BACKGROUND: Graft-vs.-host disease (GVHD) is the major cause of morbidity and mortality in patients undergoing allogeneic Bone Marrow Transplantation (BMT). The aim of our study was to identify the most relevant histological features for diagnosis of chronic Graft-vs.-Host Disease (cGVHD) in oral mucosa and minor salivary glands of 25 patients, as well as to evaluate the immunophenotype of the inflammatory cells. METHODS: Sixteen patients that were submitted to allogeneic BMT but did not present cGVHD were selected as a control group. The sections were studied on H & E and CD68, CD45, CD4, CD8, CD20 staining. RESULTS: The most frequent histologic findings in oral mucosa at the day of diagnosis of cGVHD were: hydropic degeneration of the basal layer of the epithelium, apoptotic bodies, lymphocytic infiltration, and focal or total cleavage between the epithelial and connective tissue. In the labial salivary glands (LSG), lymphocytic infiltration, acinar loss and fibrosis were the main alterations. Cytotoxic CD8-T cells and macrophages were predominant both in the epithelium and connective tissue, as well as in minor salivary glands. CONCLUSIONS: Histological features were useful in the diagnosis of oral cGVHD. It is suggested that CD8-T cells and macrophages play important role in the pathogenesis of the disease.

Frequency of the 35delG mutation in the GJB2 gene in samples of European, Asian, and African Brazilians.

Mutations in the GJB2 gene are a major cause of congenital deafness. One specific mutation, the 35delG mutation, has accounted for most of the GJB2 mutations detected in European populations and is one of the most frequent disease mutations identified so far. We evaluated the frequency of the 35delG mutation in DNA samples from Brazilians of European, Asian, and African ancestry. All DNA samples were screened for the 35delG mutation using an allele-specific PCR. This study shows that the frequency of a common mutation (35delG) is significantly lower in non-European populations.

Development of donor-specific microchimerism in liver transplant recipient with HLA-DRB1 and -DQB1 mismatch related to rejection episodes.

Migration of donor-derived cells to recipient tissues after liver transplantation has been suggested as a mechanism to induce and maintain allograft tolerance, although important issues remain including acute rejection posttransplantation mortality, and complications related to immunosuppressive therapy. We therefore examined the relation of rejection to chimerism based upon recipient and donor mismatch of HLA-DRB1 and -DQB1 alleles. Laboratory analysis of peripheral blood was performed before and 10 days to 16 months after liver transplantation in 32 recipients, using ganglion or spleen cell samples of respective donors. DNA was extracted for HLA-DRB1 and DQB1 allele typing using polymerase chain reactions with sequence-specific primers (PCR-SSP). Microchimerism was analyzed through nested PCR. Our results confirmed that patients with one or two mismatched HLA-DRB1 and-DQB1 alleles showed microchimerism and no rejection (P <.05). Microchimerism was present in 71.88% of the patients, and a significant association of rejection P <.05 was found when microchimerism was correlated to graft rejection. These results suggest that the presence of microchimerism may be associated with acceptance, tolerance and survival of the allograft.

Genetic variation and relationships at six VNTR loci in two distinct sample populations in Brazil.

BACKGROUND: The Brazilian population has been the focus of intensive genetic study due to admixture characteristics whereas there are few reports on the variability of VNTR loci in Brazil. PRIMARY OBJECTIVE: The aim of this study was to analyse genetic parameters in sample populations from two geographically distant regions: São Luis City, in Maranhão State and Campinas City, in São Paulo State. We investigated if distinct colonization influences could produce detectable differences in genetic background. SUBJECT AND METHODS: DNA samples from peripheral drained blood were obtained from unrelated individuals who underwent paternity testing. Allelic variation in six VNTR loci (D2S44, D4S139, D5S110, D8S358, DI0S28 and D17S79) was evaluated. The results were compared to reference databases available for general Latin-derived European and African-American populations as well as for other Brazilian groups. RESULTS: This study reveals that forensic population parameters did not show differences among regions, although we detected admixture values varying between the south-east and north-east of Brazil. CONCLUSIONS: Differences between the two samples are probably due to different admixture proportions of European- and African-derived alleles in each region: both populations are in Hardy Weinberg equilibrium. In addition, the allelic frequency for all loci, in both populations, can be used as database for forensic purposes.

The insulin tolerance test in morbidly obese patients undergoing bariatric surgery.

OBJECTIVE: To assess the effect of massive weight loss in relation to insulin resistance and its correlation to changes in glycemic homeostasis and lipid profile in severely obese patients. RESEARCH METHODS AND PROCEDURES: A prospective clinical intervention study was carried out with 31 morbidly obese women (body mass index: 54.2 +/- 8.8 kg/m(2)) divided into three groups according to their glucose tolerance test: 14 normal, 8 impaired glucose tolerance, and 9 type 2 diabetes. All subjects underwent an insulin tolerance test with intravenous bolus of 0.1 U insulin/kg body weight before silastic ring vertical gastroplasty Roux-en-Y gastric bypass surgery, and again at 2, 4, 6, and 12 months postoperatively. Fasting plasma glucose, hemoglobin A1c, and lipid profile were also evaluated. RESULTS: A reduction of 68 +/- 15% in initial excess body weight was evident within 1 year. Along with weight loss, the following statistically significant changes were found: an increase in the insulin-sensitivity index (Kitt) and a decrease in fasting plasma glucose and hemoglobin A1c, most notably in the type 2 diabetes group. An overall improvement in lipid profile was observed in all three groups. DISCUSSION: Bariatric surgery was an effective therapeutic approach for these obese patients because it reduced both weight and insulin resistance, along with improving metabolic parameters. Significant correlations were found between insulin resistance and metabolic improvements. Weight loss after bariatric surgery induced an improvement in metabolic fitness, related to the reduction in insulin resistance over a range of glucose tolerance statuses from normal to diabetic.

Cerebral atrophy related to corticotherapy in systemic lupus erythematosus (SLE).

The aim of this study was to evaluate the frequency and intensity of cerebral atrophy using CT scanning and the possible relation to corticosteroid therapy or disease in systemic lupus erythematosus (SLE) and to analyse the relationships between cerebral atrophy and activity disease and neuropsychiatric manifestations in lupus patients. We studied 107 consecutive SLE patients (American Rheumatology Association 1982 criteria) who were taking steroid drugs at the time and not selected for any particular manifestation (group 1). A complete clinical, neurological and laboratory evaluation was performed. The American College of Rheumatology's classification for neuropsychiatric manifestations and SLE disease activity index for activity were employed. Group 2 comprised 39 non-SLE patients with oral chronic steroid use (1 mg/k/day for more than 3 consecutive months); 50 normal individuals were the controls (group 3). There were no demographic differences between the groups. Brain CT was performed in all individuals and the frequency and the intensity (minimal, moderate and severe) of atrophy analysed, through well-defined measures and indices, by two neuroradiologists. Cerebral atrophy was significantly more frequent in groups 1 and 2 than in group 3, but with no significant difference between groups 1 and 2. The severity of cerebral atrophy was significantly higher in SLE patients (p<0.05), independent of steroid dose or duration of disease. In both groups no patient presented severe atrophy. Lupus patients with and without cerebral atrophy presented neuropsychiatric manifestations and activity disease in a similar proportion. The more frequent neuropsychiatric manifestation in lupus patients with cerebral atrophy was seizures (p<0.05). Chronic glucocorticoid therapy was responsible for cerebral atrophy, with a comparable incidence in both lupus and non-lupus patients compared to age and gender-matched normal subjects untreated with glucocorticoids. The disease activity was not related to cerebral atrophy in group 1 and seizures were the neurologic manifestation related to cerebral atrophy. The severity of the cerebral atrophy was independent of steroid dose, or duration of treatment. Moreover, the disease itself contributes to the severity of this process, but not to the development of cerebral atrophy.

Silicone versus nonsilicone gel dressings: a controlled trial.

BACKGROUND: Silicone gel dressings decrease scar volume and soften hypertrophic tissue, allowing it to be more easily controlled by other methods. Although silicone does not appear to be an essential component of the treatment, nonsilicone dressings have been reported to cause no change in physical parameters during a 2-month treatment period. OBJECTIVE: To compare silicone and nonsilicone gel dressings in the treatment of keloids and hypertrophic scars, including a control group, and to evaluate the effectiveness of these treatments using two new assessment techniques. METHODS: Patients were randomly chosen to receive silicone or nonsilicone gel dressings in a 4.5-month controlled prospective study. Scar size, induration, and symptoms were evaluated before and after the treatment. Scar color was visually measured using a color palette catalog, and a new device was developed to measure intracicatricial pressure. RESULTS: All of the measured parameters were significantly reduced in both silicone- and nonsilicone-treated groups, as compared to the control, with no significant differences between them. CONCLUSION: Silicone and nonsilicone gel dressings are equally effective in the treatment of keloids and hypertrophic scars.

[Community genetics and hemophilia in a Brazilian population]. / Genética comunitária e hemofilia em uma população brasileira.

Hemophilia is an important hemorrhagic disease in Brazil, affecting about 1 out of every 10,000 males. Patient's self-perception of hemophilia and interaction with the community are relevant to the clinical management of this disease. We investigated several social, psychological, and community aspects of hemophilia in a Brazilian population (Campinas, São Paulo State), interviewing 30 hemophiliac males, a control sample comprised of 73 non-hemophiliac brothers, and 641 individuals from the community. According to our results, more severe social disability in the hemophiliac patient was related to economic factors, mainly unemployment; however, no difference was found in relation to marital status, reproduction, or education. Self-perception of changes in health and lifestyle by individuals with hemophilia showed frequent self-stigmatization, along with depression, anxiety, and insecurity. The community showed a widespread lack of familiarity with hemophilia (49%), viewing people with hemophilia with the kinds of prejudices often observed in relation to people with infectious diseases, like AIDS. The paper concludes by recommending that a community-based program be implemented to improve the social adjustment status of individuals with hemophilia.

Serum leptin levels after bariatric surgery across a range of glucose tolerance from normal to diabetes.

BACKGROUND: A longitudinal, clinical intervention study with bariatric surgery was done to investigate the relationship between leptin levels, BMI, and insulin during weight loss across a range of glucose tolerance from normal to diabetes. METHODS: 43 morbidly obese patients (BMI: 42-75 kg/m2) undergoing vertical banded gastroplasty Roux-en-Y gastric bypass (VBG-RGB), were divided into 3 groups: 21 normal (NGT), 12 impaired glucose tolerance (IGT) and 10 type 2 diabetes (DM). Leptin, insulin, glucose, lipids and uric acid were measured at baseline and 2, 4, 6, and 12 months following surgery. RESULTS: BMI fell from 54.1 +/- 9.1 to 34.6 +/- 6.3 kg/m2, similarly in all groups. Leptin decreased from 73.9 +/- 8.7 to 16.9 +/- 10.2 ng/ml and was strongly correlated with BMI during 1-year follow-up (r = 0.78; p < 0.001). Linear univariate analysis for repeated evaluation showed a positive correlation between leptin and glucose, triglycerides, uric acid, and insulin. Multivariate regression analysis indicated that BMI was independently correlated with the decrease in leptin (p < 0.001), accounting for 66% of the variance in leptin levels during weight loss. These results were found in the NGT and IGT groups. In the DM group, a small additional influence in leptin levels was attributed to glucose decrease. CONCLUSIONS: A strong link between leptin and BMI was found after surgery. BMI was the main determinant of the decrease of leptin. In these patients submitted to bariatric surgery, ranging from normal glucose tolerance to diabetes, changes in insulin levels and metabolic parameters, except for glucose in the DM group, did not appear to be correlated with changes in leptin levels.

Prostate elastosis: a microscopic feature useful for the diagnosis of postatrophic hyperplasia.

BACKGROUND: Elastosis of the prostate may be seen on needle biopsy and radical prostatectomy specimens, but its significance is unknown. Prostatic atrophy (or postatrophic hyperplasia) is one of the most frequent mimics of prostatic adenocarcinoma. OBJECTIVE: To observe the frequent occurrence of elastosis of the prostate stroma in areas of postatrophic hyperplasia. DESIGN: A step-section method was used to cut the posterior lobe (or peripheral zone) in coronal planes at intervals of 0.3 to 0.5 cm in 100 consecutive autopsy specimens of men older than 40 years. Elastosis was detected because of a basophilic tinge of the stroma on hematoxylin-eosin stain and confirmed using elastic fiber stains. Presence of elastosis correlated with the following variables: age, prostatic atrophy (simple, hyperplastic, or sclerotic), local arteriosclerosis, histologic carcinoma, high-grade prostatic intraepithelial neoplasia, benign or malignant nephrosclerosis, generalized atherosclerosis, nodular prostatic hyperplasia, and acute inflammation. For statistics, a stepwise linear regression method adjusted for age was used. RESULTS AND CONCLUSIONS: Elastosis was found in 65 of the prostates examined and was significantly more frequent with increasing age (P <.001), prostatic atrophy (P <.001), and local arteriosclerosis (P <.02). There was no significant relation to histologic carcinoma, high-grade prostatic intraepithelial neoplasia, benign or malignant nephrosclerosis, generalized atherosclerosis, nodular prostatic hyperplasia, and acute inflammation. The correlation with local arteriosclerosis favors a possible role of ischemia to its etiopathogenesis. The absence of correlation to neoplastic and preneoplastic lesions and the striking spatial relationship of elastosis to prostatic atrophy (or postatrophic hyperplasia) add a new microscopic feature for the diagnosis of this latter lesion, helping in the differential diagnosis with prostate adenocarcinoma.

Hepatitis E virus immunoglobulin G antibodies in different populations in Campinas, Brazil.

The seroprevalence of anti-hepatitis E virus (HEV) antibodies was investigated by enzyme immunoassay in 205 volunteer blood donors, 214 women who attended a center for anonymous testing for human immunodeficiency virus (HIV) infection, and 170 hospital employees in Campinas, a city in southeastern Brazil. The prevalence of anti-HEV antibodies ranged from 2.6% (3 of 117) in health care professionals to 17.7% (38 of 214) in women who considered themselves at risk for HIV. The prevalence of anti-HEV antibodies in health care professionals was not significantly different from that in healthy blood donors (3.0%, 5 of 165) and blood donors with raised alanine aminotransferase levels (7.5%, 3 of 40). The prevalence of anti-HEV antibodies (13.2%, 7 of 53) in cleaning service workers at a University hospital was similar to that among women at risk for HIV infection. These results suggest that HEV is circulating in southeastern Brazil and that low socioeconomic status is an important risk factor for HEV infection in this region.

Bone mineral density, vitamin D and anticonvulsant therapy.

UNLABELLED: The aim of this study was to assess bone mineral density and vitamin D metabolism in patients on chronic anticonvulsant therapy. METHODS: Sixty-nine men, outpatients on chronic anticonvulsant therapy, who had been treated for at least 5 years, were studied, comparing them to thirty healthy controls. Bone mineral density was measured as well as serum levels of calcium, ionized calcium, alkaline phosphatase, PTH, 25-hydroxycholecalciferol and 1, 25-dihydroxycholecalciferol. RESULTS: No differences in bone mineral density, serum levels of vitamin D and intact-PTH were observed between patients and controls. Bone mineral density was not associated with chronic anticonvulsant therapy. CONCLUSION: Those adult patients who were on chronic anticonvulsant therapy and who lived in low latitude regions had normal bone mineral density as well as vitamin D serum levels.