Influence of thyroid hormone receptors on breast cancer cell proliferation

BACKGROUND

The involvement of thyroid hormones in the development and differentiation of normal breast tissue has been established. However, the association between breast cancer and these hormones is controversial. Therefore, the objective of the present study was to determine the protein expression pattern of thyroid hormone receptors in different human breast pathologies and to evaluate their possible relationship with cellular proliferation.

PATIENTS AND METHODS

The presence of thyroid hormone receptors was evaluated by immunohistochemistry and western blot analysis in 84 breast samples that included 12 cases of benign proliferative diseases, 20 carcinomas in situ and 52 infiltrative carcinomas.

RESULTS

TR-alpha was detected in the nuclei of epithelial cells from normal breast ducts and acini, while in any pathological type this receptor was located in the cytoplasm. However, TR-beta presented a nuclear location in benign proliferative diseases and carcinomas in situ and a cytoplasmatic location in normal breast and infiltrative carcinomas. The highest proliferation index was observed in carcinomas in situ, although in infiltrative carcinomas an inverse correlation between this index and the TR-alpha expression was encountered.

CONCLUSIONS

The results of this study reveal substantial changes in the expression profile of thyroid hormone receptors suggesting a possible deregulation that could trigger breast cancer development.

Updated Metaanalysis of Steroid Withdrawal in Renal Transplant Patients on Calcineurin Inhibitor and Mycophenolate Mofetil

During the 1990s two metaanalysis of randomized clinical trials of steroid withdrawal after renal transplantation showed significant increases in acute rejection episodes and graft failure rates. A recently published metaanalysis of steroid withdrawal in patients on a calcineurin inhibitor and MMF included randomized clinical trials. We have updated this study, searching more publications during the last 2 years. Finally, the same six trials were included, four in patients receiving cyclosporine and two tacrolimus. Risk ratio (RR) for acute rejection was 2.28 [95%CI 1.65-3.16, P < .00001], and pooled risk difference (RD) was 0.08 [0.05-0.11, P < .001], indicating that the proportion of patients with acute rejection episodes after prednisone withdrawal was significantly higher compared with controls. RR for graft failure was 0.73 [0.42-1.28, P = .27], and RD was -0.01 [-0.03-0.01, P = .28], indicating that the proportion of patients with graft failure after withdrawal was not significantly different from that of controls. Total cholesterol was significantly lower after steroid withdrawal (weighted mean difference -0.53 mumol/L [-0.70--0.36, P < .0001]). Renal allograft recipients on triple therapy with a calcineurin inhibitor, MMF, and steroids are at low but significant risk of acute rejection after steroid withdrawal, but do not suffer an increased risk of early graft failure. It is necessary to extend controlled follow-up to confirm graft function stabilization.

Modifications of Renal Blood Flow and Serum Interleukin Levels Induced by Laparoscopic and Open Living Donor Nephrectomies For Kidney Transplant: An Experimental Study in Pigs

The increase of intraabdominal pressure (IAP) during laparoscopy modifies renal blood flow (RBF). However, laparoscopic techniques are less invasive than open procedures. The use of interleukins (IL) to evaluate operative trauma of different surgical techniques is controversial. The aim of the study was to analyze the, modifications induced by laparoscopic and open nephrectomies on RBF, renal function and IL levels. Thirty pigs underwent left nephrectomy, 15 by laparoscopy and 15 by an open approach in an experimental autotransplant model. A significant reduction in RBF was observed among the laparoscopic (80 +/- 27 mL/min) versus the open group (263 +/- 3 mL/min, P < .05). Laparoscopy reduced glomerular filtration (GF) (37.6 +/- 1.1%) to a greater extent than an open technique (80.5 +/- 0.4%; P < .05). Serum levels of IL-2, IL-6, IL-10, and tumor necrosis factor (TNF) were lower during laparoscopic than open nephrectomy: 6.8 +/- 0.6 versus 13 .9 +/- 1.1 pg/mL for IL-2, 46.2 +/- 2.3 versus 84.4 +/- 2.5 pg/mL for IL-6, 26.1 +/- 2.4 versus 92.8 +/- 12.6 pg/mL for IL-10, and 17.6 +/- 2.1 versus 38.5 +/- 4.8 pg/mL for TNF (P <.001). In conclusion, laparoscopic nephrectomy for living donor kidney transplant induced significant reductions in RBF and GF. However, there was less increase in IL levels during laparoscopic than the open approach. The influence of these circumstances on graft function after kidney transplantation is not clearly established.

MHC-F DNA sequences in bonobo, gorilla and orangutan

The major histocompatibility complex (MHC)-F class Ib locus shows a limited polymorphism, and the function of its mainly intracellular protein is not clear. We have identified human leucocyte antigen (HLA)-F orthologous DNA sequences in Pongidae in order to study the MHC-F gene evolution and its products' function. HLA-F orthologous cDNA transcripts are found in chimpanzee and in the new primate species studied (bonobo, gorilla and orangutan). Analyses of the predicted amino acid sequences and their comparison with other primate MHC-F proteins show that MHC-F may be a protein with a typical class I structure and that the key residues of the peptide-binding region (PBR) are highly conserved in MHC-F in all studied primates species. Thus, MHC-F conservation along the primate evolution suggests an important role in cellular physiology. It is possible that the MHC-F protein could be involved, together with MHC-G and MHC-E, in the natural killer (NK) cell activity regulation, although rhesus macaque does not express MHC-G and MHC-E orthologues. The evolutionary pathway of the six-base-pair deletion at exon 2 existing in some primates is put forward.

Origin of Aymaras from Bolivia and their relationship with other Amerindians according to HLA genes

Aymara Amerindians from the Titicaca Lake Andean highlands are studied for HLA-A, HLA-B, HLA-DRB1 and HLA-DQB1 gene frequencies. Genetic distances, neighbour-joining and correspondence analyses are performed by using other Amerindian and worldwide populations (15384 chromosomes are studied). The HLA genetic profile of Aymaras is different from neighbouring and language-related Quechuas (Incas). Both Quechuas and Aymaras seem to present an HLA-DRB1*0901 high frequency, which is present in a very low frequency or absent in Mesoamericans (Mazatecans, Mayans) and most studied Amerindians. Moreover, it is observed a closer relatedness of Aymaras with Amerindians from the Amazon Basin and Chaco lowlands, compared to Quechuans.

Antioxidant enzymes in hypertensive and hypertriglyceridemic rats: effect of gender

In a model of hypertensive and hypertriglyceridemic rats (HTG), in which oxidative stress is increased, the influence of gender upon activities of catalase (CAT), glutathione peroxidase (GPX), and superoxide dismutase (SOD) was investigated. Statistically significant differences between antioxidant enzyme activities and treatment with relation to gender were analyzed. Weanling Wistar rats were given normal rat chow and either tap water for control group or 30% sucrose solution for HTG group, for 5-6 months. At the end of the experimental period, blood pressure was significantly higher in both male and female HTG groups, but males showed higher values than females. Serum, heart, kidney, and liver were obtained to determine antioxidant enzyme activities. Activities of CAT and GPX tended to be higher in male animals. A larger number of significant changes in enzyme activities associated with gender appears in HTG than in controls, which indicates the harmful effect of the treatment.

Activities of antioxidant enzymes in two stages of pathology development in sucrose-fed rats

The activities of catalase in liver, heart and kidney as well as glutathione peroxidase and superoxide dismutase in liver, heart, kidney, and serum from hypertriglyceridemic and hypertensive female and male rats were measured at 3 and 8 months of daily administration of sucrose in their drinking water. This treatment induces high levels of serum triglycerides, central obesity, moderate hypertension, hyperinsulinemia, and an increase in lipoper oxida tion, among other alterations. The experimental periods were chosen on the basis of previous observations: at 3 months the level of serum triglycerides increases significantly above the normal value and remains without major changes thereafter, but the blood pressure only rises significantly at about 4 months in males and 5 months in females. So, at 8 months the rats have been subjected to abnormal conditions for 3–4 months. The effect of these and the influence of sex on levels of antioxidant enzymes were investigated. Both factors, sucrose treatment and sex, were conducive to significant changes in those variables.Key words: antioxidant enzymes, gender influence, hypertriglyceridemia, hypertension, sucrose-fed rats.

HLA class I allele distribution of a Hong Kong Chinese population based on high-resolution PCR-SSOP typing

A stem cell registry population from Hong Kong, of Chinese ethnicity, was examined for HLA-A and HLA-B alleles using a two-stage sequence-specific oligonucleotide probe system. Comparison of the HLA-A and HLA-B frequencies with different populations showed a close relationship with a Chinese population from Singapore, although there were several differences in the presence/absence of alleles at the HLA-B locus. Having the data available on these registry donors will influence the search strategy and the ongoing compilation of new donors to the registry. In addition, knowing which alleles do/do not occur in this population will aid in the distinction of ambiguities which result from the use of many of the typing kits available.

Immunosuppressive treatment for idiopathic membranous nephropathy in adults with nephrotic syndrome

BACKGROUND

Idiopathic membranous nephropathy (IMN) is the most common form of nephrotic syndrome in adults. The disease shows a benign or indolent course in the majority of patients, with a rate of spontaneous complete or partial remission of nephrotic syndrome as high as 30% or more. Despite this, 30-40% of patients progress toward end-stage renal failure (ESRF) within 5-15 years.

OBJECTIVES

To assess the benefits and harms of immunosuppressive treatment for IMN in adults.

SEARCH STRATEGY

We searched the Cochrane Renal Group Specialised Register (December 2003), The Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library Issue 4, 2003), MEDLINE and Pre-MEDLINE (1966 - December 2003), EMBASE (1980 - December 2003), reference lists of nephrology textbooks, review articles, prospective trial registers, relevant trials and abstracts from nephrology scientific meetings and the internet without language restriction. We also contacted principal investigators of controlled studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) and quasi-RCTs comparing any immunosuppressive interventions for the treatment of IMN in adults.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed and extracted information. Information was collected on method, participants, interventions and outcomes (death, ESRF, proteinuria, serum creatinine, GRF, remission, adverse events).

MAIN RESULTS

A total of 18 trials with 1025 patients were included. No differences were found when we combined data of all treatment categories as a group and compared them with placebo or no treatment. Oral glucocorticoids. No beneficial effect on any of the end points chosen for efficacy was observed. Alkylating agents showed a significant beneficial effect on complete remission (RR 2.37, 95%CI 1.32 to 4.25, P = 0.004) but not on partial remission (RR 1.22, 95%CI 0.63 to 2.35, P = 0.56) or complete or partial remission (RR 1.55, 95%CI 0.72 to 3.34, P = 0.27). Cyclophosphamide treatment resulted in significantly lower rate of discontinuations due to adverse events as compared to chlorambucil (RR 2.34, 95%CI 1.25 to 4.39, P = 0.008). There was no evidence of clinically relevant differences in favour of cyclosporin and there was insufficient data on anti-proliferative agents.

REVIEWERS' CONCLUSIONS

This review failed to show any long-term effect of immunosuppressive treatment on patient and/or renal survival. There was an increased number of discontinuations due to adverse events in immunosuppressive treatment groups. Within the class of alkylating agents there is weak evidence supporting the efficacy of cyclophosphamide as compared to chlorambucil. On the other hand, cyclophosphamide had fewer side effects leading to patient withdrawal than chlorambucil.

Increased fibrin polymerization rate in patients with primary antiphospholipid syndrome and systemic lupus erythematosus

The main event in blood coagulation is the thrombincatalyzed conversion of fibrinogen into fibrin. This singular transformation of a soluble protein into an insoluble polymeric network occurs with faultless precision. Abnormalities of fibrin polymerization can lead to hemorragic and thrombotic disorders. Increased fibrinogen plasma concentration (Fg) and fibrin polymerization rate (FPR) could be additional risk factors associated with atherothrombosis in antiphospholipid syndrome (APS) and in systemic lupus erythematosus (SLE). Our objective was to investigate Fg and FPR in consecutive patients with APS and SLE. Thirty-nine patients and 31 age- and gender-matched healthy controls were studied. Sixteen patients had primary APS, 13 patients had SLE, and 10 patients had SLE plus APS. The mean of the FPR was significantly increased (0.2799 +/- 0.091) in patients with APS plus SLE as compared with the control group (0.2052 +/- 0.055) (p < 0.05). Fg was higher in APS plus SLE (3.15 g/L +/- 0.43) and in primary APS (3.03 g/L +/- 0.29) than in controls (2.87 g/L +/- 0.49). Our results demonstrated an increased FPR in patients with APS plus SLE. This phenomenon could be an additional risk factor for thrombosis in these autoimmune diseases.

Origin of Mayans according to HLA genes and the uniqueness of Amerindians

The HLA allele frequency distribution of the Mayans from Guatemala was studied and compared with those of other First American Natives and worldwide populations (a total of 12,364 chromosomes and 6182 individuals from 60 different populations). The main conclusions were (1): the closest Amerindian group to Mayans is the Arhuacs, who were the first recorded Caribbean Islands' inhabitants (2). Mayans are not so close to Mesoamerican Zapotec, Mixe and Mixtec Amerindians, who genetically cluster together. Mixe had been related to Mayans only on linguistic bases (3). DRB1*0407 and DRB1*0802 alleles are found in 50% of Mayans; these alleles are also found in other Amerindians, but the Mayans' high frequencies may be showing a founder effect for this Mesoamerican-Caribbean population (4). Extended Mayan specific HLA haplotypes are described for the first time (5). Language and genes do not completely correlate in microgeographical studies (6). Significant genetic input from outside is not noticed in Meso and South American Amerindians according to the genetic analyses; while all world populations (including Africans, Europeans, Asians, Australians, Polynesians, North American Na-Dene Indians and Eskimos) are genetically related. Meso and South American Amerindians tend to remain isolated in the neighbour joining analyses.

HLA alleles in isolated populations from North Spain: origin of the Basques and the ancient Iberians

HLA-A, -B, -DRB1, -DQA1 and -DQB1 alleles have been studied in three relatively isolated populations of northern Spain from Cantabria ( Pas Valleys inhabitants or Pasiegos and Cabuernigos) and from the Basque Country (Arratia Valley inhabitants). These populations have been compared with neighbouring ones and other Mediterraneans by using neighbour-joining dendrograms and plane genetic distances.

Ciliate communities of rotating biological contactor biofilms: a multivariate approach

Physical-chemical monitoring and characterization of ciliate communities from a full-scale rotating biological system (RBC) have been carried out for a year. RBC system operated efficiently in removing the organic matter, as the decrease of the BOD5 loading along the successive RBC units revealed. 55 species of ciliated protozoa were identified in the RBC biofilms. Differences in abundance, occurrence and type of species were found along the different units of the RBC system; the last RBC held a more stable and diverse ciliate community. The complexity of interspecific relationships among the ciliates has been outlined using multivariate methods (Cluster and Correspondence analysis). Correlation between ciliate species and physical-chemical conditions were obtained by regression analysis. Results show that 12 species of ciliates were related to an optimal efficiency in organic matter removal, Litonotus crystallinus being the most sensitive species. The presence and abundance of Litonotus crystallinus and Acineria uncinata was associated with a decrease in the organic factor. Metopus es was the only species related to a decrease in process efficiency due to its association with an increase in organic factor. The results provide statistical evidence of the use of certain ciliate species as reliable bioindicators in full-scale RBC wastewater treatment plants.

Modelling complex populations formed by proliferating, quiescent and quasi-quiescent cells: application to plant root meristems

A proliferating population of cells may be considered complex when its proliferative or growth fraction P is lower than 1 and/or when it is formed by subpopulations with different mean cycle times. The present paper shows that in such complex populations exponential growth is consistent with a steady-state distribution of cells. Obviously, when P=1 then cell distribution is only a function of cell age. An analytical model has been developed to study complex populations including both quiescent fractions formed by cells with unreplicated genome (G(0) cells) and cells with fully duplicated chromosomes (Q(2) cells). The model also considers those quasi-quiescent cells in their last transit through G(1) and S (Q(1) and Q(s) cells) before becoming quiescent. In order to solve the difficulties of a direct analysis of the whole population, its kinetic parameters have been obtained by studying the negative exponential distribution of two subpopulations: one formed by the proliferating cells and another formed by the quasi-quiescent cells. Additionally, the model could be applied when quiescence is initiated at any other cycle phase different from G(1) and G(2), for instance, cells in the process of replicating their DNA or being at any other mitotic phases. The utility of the method was illustrated in populations which constitute the root meristems of both Allium cepa L. and Pisum sativum L. Three facts should be stressed: (1) the method seems to be rather powerful because it can be carried out from different sets of experimentally measured parameters; (2) the rate of division and, therefore, the population doubling time can be easily estimated by this method; and (3) it also allows the determination of the amount of cells that had become quiescent either before they had replicated their DNA (G(0)) or after having completed their replication (Q(2)), as well as those quasi-quiescent cells which are progressing throughout their last pre-replicative and replicative periods (thus Q(1) and Q(s), respectively).

[Hypothyroidism protects the myocardium against ischemia-reperfusion injury]

This work describes experimental results indicating that mitochondria from hypothyroid rats are resistant to suffer membrane permeability transition as induced by matrix calcium accumulation. It is also shown that hypothyroidism provides resistance to myocardial reperfusion injury, after a period of 5 min ischemia. It is concluded that the protection is due to a low expression of mitochondrial proteins, as well as to a lack in cardiolipin as constituent of the lipid bilayer of the inner mitochondrial membrane.