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Biomedical subjects

A Alcaraz

Publications and source records attributed to A Alcaraz.

At least 37 records · Page 2Linked to original sources

Tacrolimus in induction immunosuppressive treatment in renal transplantation: comparison with cyclosporine.

The aim of the study was to compare the efficacy and safety of induction immunosuppression therapies based on tacrolimus or cyclosporine (CsA) in kidney transplantation. The 240 kidney allograft recipients were divided into two groups: group 1 (n=94) received tacrolimus (.01 mg/kg per day), mycophenolate mofetil (MMF, 2 g/d), and steroids (30 mg/d); and group 2 (n=146) CsA (6 mg/kg per day), MMF (2 g/d), and steroids (30 mg/d). Antilymphocyte serum was administered in cases of acute tubular necrosis. The acute rejection rate was higher among group 2 (30.6%) compared with group 1 patients (12.2%) (P=.001). There were no significant differences between the groups in terms of age, gender, body surface area, serologic virus markers (in donor and recipient), baseline creatinine levels, cause of death, HLA incompatibilities, response to acute tubular necrosis, and number of dialysis sessions. We conclude that both immunosuppressive regimens are effective and safe in kidney transplantation. The survival rates of patients and grafts were similar, but the incidence and degree of acute rejection events were reduced in group 1; this finding may forecast a decreased incidence of chronic renal allograft nephropathy.

Adrenal Cortex Hormones↗

Significance of cytomegalovirus infection in renal transplantation.

The aim of this study was to establish the relationship between vascular lesion chronic allograft nephropathy (CAN) and the presence of cytomegalovirus (CMV) in kidney transplanted patients. We studied 259 consecutive kidney transplant recipients with a minimum follow-up of 6 months; the induction immunosuppressive therapy included a calcineurin inhibitor, mycophenolate mofetil, steroids, and the use of an antilymphocyte serum if the patients developed delayed graft function. CMV early antigen detection (pp65) was performed on a weekly basis between days 30 and 90 post transplantation. Prophylactic treatment was administered in the donor +/recipient-risk group, and preemptive therapy delivered for positive antigenemia namely 3 days of intravenous [IV] gancyclovir [GCV] plus 11 days of oral therapy [in the case of infection], or 14 days of IV GCV [in the case of disease]). An acute kidney allograft rejection episode preceded CMV in 64.3% of the patients, and CMV preceded acute rejection in 35.7% of the cases. We conclude that CMV disease is an independent risk factor for CAN. CMV infection is probably associated with CAN, suggesting that the greater the viral load, the higher the risk of CAN. It may be advisable to perform universal prophylaxis to lower the viral load and CAN.

Cytomegalovirus Infections↗

Use of recombinant human erythropoietin in kidney transplant patients with stable graft function.

The purpose of this work was to determine the necessity for rhuEPO for 50 kidney transplant patients with stable graft function. We analyzed the red cell series, blood pressure, renal function, anthropometric data of the donor and recipient, proteinuria, and relationship with other factors, including immunosuppressants, angiotensin converting enzyme (ACE) inhibitors and angiotensin receptor blockers (ARB). The patients were divided into three groups depending on renal function: group A (with plasma creatinine <150 micromol/L), group B (151-250 micromol/L), and group C (>250 micromol/L). All patients were studied for 1 year. Erythropoietin use did not affect renal function, proteinuria or number of antihypertensive drugs group. The degree of renal dysfunction determined the time necessary to reach an adequate hemoglobin level (>12 g/L) and and the mean dose of weekly rhuEPO needed. The use of ACE inhibitors or ARBs increased the rhuEPO requirements in each group.

Angiotensin-Converting Enzyme Inhibitors↗

High-grade prostate intraepithelial neoplasia shares cytogenetic alterations with invasive prostate cancer.

BACKGROUND: High-grade prostate intraepithelial neoplasia (PIN) is the most likely precursor of prostate adenocarcinoma. However, the relationship between this lesion and prostate cancer has not yet been established. The detection of cytogenetic changes in the lesions prior to prostate adenocarcinoma would be useful in demonstrating such a pathogenic relationship. METHODS: Twenty eight high-grade PIN cases were found among 57 specimens of radical prostatectomy performed for clinically localized prostate cancer. Fluorescence in situ hybridization (FISH) analysis using centromeric probes to enumerate chromosomes 7, 8, 10, and 12 was performed to study the numerical chromosome alterations. FISH analysis was carried out over isolated nuclei obtained from high-grade PIN areas and prostate cancer foci in the same prostatectomy specimen. RESULTS: Of the 28 suitable cases it was possible to complete the study in 26 tumor and 20 PIN areas. The remaining cases were excluded because of insufficient tissue or poor preservation. Cytogenetic alterations (aneuploidy) were found in 16 of the 26 (62%) tumors studied. The most frequent chromosome alteration was trisomy 7, detected in 12 (75%) aneuploid tumors, followed by monosomy 8 present in 5 (31%) aneuploid tumors. Trisomy 7 was also the most frequent isolated chromosome alteration since it was detected in 7 (44%) tumors. Thirteen of 20 (65%) PIN cases were aneuploid when studied by FISH. Trisomy 7, trisomy 8, and monosomy 8 were the most common cytogenetic alterations in the 20 PIN areas studied, being observed in nine (45%), six (30%), and four (20%) cases, respectively. FISH analysis showed a high correlation (75% cases) in ploidy and pattern of cytogenetic alterations between high-grade PIN areas and the paired prostate cancer focus in the same specimen. CONCLUSIONS: The above results show a cytogenetic link between high-grade PIN and prostate cancer, suggesting that the former could be an early form of prostate cancer.

Adenocarcinoma↗

Interleukin-12 promotes pathologic liver changes and death in mice coinfected with Schistosoma mansoni and Toxoplasma gondii.

We previously demonstrated that mice concurrently infected with Schistosoma mansoni and Toxoplasma gondii undergo accelerated mortality which is preceded by severe liver damage. Abnormally high levels of serum tumor necrosis factor alpha (TNF-alpha) in the dually infected mice suggested a role for this and related proinflammatory mediators in the pathologic alterations. In order to evaluate the factors involved in increased inflammatory-mediator production and mortality, interleukin-12(-/-) (IL-12(-/-)) mice were coinfected with S. mansoni and T. gondii, and survival and immune responses were monitored. These IL-12(-/-) mice displayed decreased liver damage and prolonged time to death relative to wild-type animals also coinfected with these parasites. Relative to the response of cells from the coinfected wild-type animals, levels of TNF-alpha, gamma interferon, and NO produced by splenocytes from coinfected IL-12(-/-) mice were reduced, and levels of IL-5 and IL-10 were increased, with the net result that the immune response of the dually infected IL-12(-/-) mice was similar to that of the wild-type mice infected with S. mansoni alone. While dually infected wild-type animals succumb in the absence of overt parasitemia, the delayed death in the absence of IL-12 is associated with relatively uncontrolled T. gondii replication. These data support the view that S. mansoni-infected mice are acutely sensitive to infection with T. gondii as a result of their increased hepatic sensitivity to high levels of proinflammatory cytokines; IL-12 and TNF-alpha are implicated in this process.

Animals↗

Neutrophil depletion during Toxoplasma gondii infection leads to impaired immunity and lethal systemic pathology.

The immunomodulatory role of neutrophils during infection with Toxoplasma gondii was investigated. Monoclonal antibody-mediated depletion revealed that neutrophils are essential for survival during the first few days of infection. Moreover, neutrophil depletion was associated with a weaker type 1 immune response as measured by decreased levels of gamma interferon, interleukin-12 (IL-12) and tumor necrosis factor alpha. IL-10 was also decreased in depleted animals. Additionally, splenic populations of CD4(+) T cells, CD8(+) T cells, and NK1.1(+) cells were decreased in depleted mice. Neutrophil-depleted mice exhibited lesions of greater severity in tissues examined and a greater parasite burden as determined by histopathology and reverse transcription-PCR. We conclude that neutrophils are critical near the time of infection because they influence the character of the immune response and control tachyzoite replication.

Animals↗

Normothermic recirculation reduces primary graft dysfunction of kidneys obtained from non-heart-beating donors.

Our aim was to analyze the short- and long-term function of kidneys procured from non- heartbeating donors (NHBD) by means of three techniques: in situ perfusion (ISP), total body cooling (TBC) and normothermic recirculation (NR). Fifty-seven potential NHBD were included. Mean warm ischemia time was 68.9 +/- 35.6 min. Forty-four kidneys were obtained from donors perfused with ISP, 8 with TBC, and 8 with NR. Eighteen kidneys (32%) started functioning immediately, 29 (52%) showed delayed graft function (DGF) and 9 (16%) showed primary non function (PNF). The actuarial graft survival rate was 76.4% at 1 year and 56% at 5 years. The patient survival rate was 89.3% at 5 years. Incidence of DGF and PNF was significantly lower in kidneys perfused with NR than those with ISP or TBC (P < 0.01). Duration of DGF was shorter in kidneys obtained through TBC than in kidneys obtained with ISP (P < 0.05). In conclusion, NR reduces the incidence of DGF and may be considered the method of choice for kidney procurement from NHBD.

Adult↗

p53 expression predicts progression and poor survival in T1 bladder tumours.

OBJECTIVES: Histological grade (G) is the only parameter proved to have prognostic value for progression in T1 transitional cell carcinoma (TCC) of the bladder, although it is considered inaccurate to make clinical decisions on individuals. The aim of the present study was to evaluate the prognostic relevance of p53 expression in T1 TCC of the bladder. METHODS: Clinical records of 207 patients with T1 TCC of the bladder were reviewed for clinical parameters reported to influence the evolution of superficial bladder cancer. Among these 207 patients, 40 developed muscle-invasive disease (20 G2 and 20 G3). A retrospective case-control study was then carried out comparing the latter 40 tumours with 40 control tumours matched by grade, sex, age, number and size of the tumours, chemical exposure and presence of carcinoma in situ. p53 immunostaining with monoclonal antibody was performed in these two groups. RESULTS: Histological grade was the only clinical parameter that influenced evolution. p53 expression correlated with tumour progression, since it was observed in 21 out of 24 p53-positive tumours and in only 20 of 56 p53-negative tumours (p<0.0001), showing a specificity of 93. 5% and a sensitivity of 53%. p53 expression correlated as well with patient survival, being 39% in patients with p53-positive tumours and 80% in patients with p53-negative tumours at 60 months (p<0. 0001). CONCLUSIONS: p53 protein expression has prognostic value for survival and progression in T1 bladder tumours and can be used for early detection of poor-prognosis T1 bladder tumours.

Adult↗

Toxoplasma gondii and Schistosoma mansoni synergize to promote hepatocyte dysfunction associated with high levels of plasma TNF-alpha and early death in C57BL/6 mice.

To address the question of how the murine host responds to a prototypic type 1 cytokine inducer while concurrently undergoing a helminth-induced type 2 cytokine response, C57BL/6 strain animals with patent schistosomiasis mansoni were orally infected with the cystogenic Toxoplasma gondii strain ME49. Schistosoma mansoni infection resulted in a significantly higher mortality rate when mice were subsequently orally infected with ME49, and these animals displayed a defective IFN-gamma and NO response relative to animals infected with T. gondii alone. Plasma levels of TNF-alpha and aspartate transaminase in double-infected mice were greatly elevated relative to mice infected with either parasite alone. Consistent with the latter observation, these animals exhibited severe liver pathology, with regions of coagulative necrosis and hepatocyte vacuolization unapparent in mice carrying either infection alone. Interestingly, mean egg granuloma size was approximately 50% of that in mice with S. mansoni infection alone. The exacerbated liver pathology in coinfected mice did not appear to be a result of uncontrolled tachyzoite replication, because both parasite-specific RT-PCR analysis and immunohistochemical staining demonstrated a low number of tachyzoites in the liver. We hypothesize that mortality in these animals results from the high level of systemic TNF-alpha, which mediates a severe liver pathology culminating in death of the animal.

Animals↗

Numeric alterations in chromosomes 7 and 8 detected by fluorescent in situ hybridization correlate with high-grade localized prostate cancer.

OBJECTIVE: To compare the ability of flow cytometry (FCM) and fluorescent in situ hybridization (FISH), using a small set of 4 enumeration chromosome probes to detect aneuploidy in prostate tumors, and to correlate it with histological grade and pathological stage. METHODS: Among 28 suitable cases, 21 could be analyzed by FISH and FCM techniques. DNA centromeric probes were used in FISH analysis to enumerate chromosomes 7, 8, 10 and 12. RESULTS: (a) Of the 21 cases studied by FISH, 5 were diploid, 14 aneuploid and 2 were tetraploid. When studied by FCM, these tumors were: 14 diploid, 6 aneuploid, and 1 tetraploid. FISH proved to have a higher ability for detecting DNA aneuploidy than FCM while been equally specific, since all tumors aneuploid by FCM were also found to be aneuploid by FISH. (b) Of the 14 aneuploid tumors, 12 were of high histological grade, while only 2 of the 7 nonaneuploid were of high grade. A statistically significant association was observed between high histological grade and FISH aneuploidy (p = 0.033). (c) All the aneuploid tumors showed chromosome 7 and/or 8 aneusomy. Trisomy 7 and monosomy 8 were the most frequent alterations present in 56 and 42% of the aneuploid tumors, respectively. CONCLUSION: FISH analysis of chromosome 7 and 8 alterations proved to be more sensitive than FCM in the detection of aneuploid prostate tumors. This aneuploidy was significantly associated with a poor pathological prognosis.

Aneuploidy↗

Transient induction of heme oxygenase after cortical stab wound injury.

Heme oxygenase (HO) exists as two isoenzymes designated heme oxygenase-1 (HO-1) and heme oxygenase-2 (HO-2). HO-1 has been identified as a heat shock or stress protein and is inducible whereas HO-2 is largely refractory to induction. HO-2 is the predominant isoenzyme in normal brain and appears to have a predominantly neuronal distribution in cerebral cortex. Cortical stab wound injury resulted in HO-1 induction as determined by Western blot analysis. Immunohistochemical analysis suggested that induced HO-1 was largely restricted to reactive astrocytes and macrophage-like cells. Enhanced HO-1 immunoreactivity was observed in hypertrophied, GFAP+ reactive astrocytes near the wound margin as early as 12 h after injury. Very rarely were HO-1+ neurons observed and then only up to 6 h after stabbing. Maximal numbers of HO-1+ astrocytes were found 3 days after stabbing. Their numbers declined thereafter. By 5 days after stab injury few HO-1+ reactive astrocytes were observed although GFAP+ reactive astrocytes were still prominent near the wound margin. HO-1+ macrophage-like cells were initially observed between 1 and 3 days after injury and they persisted in the margin of the wound for at least 14 days. The proximity of HO-1+ cells to the wound margin suggests that factors associated with injury contribute to the regulation of HO-1 in injured cortex.

Animals↗