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Biomedical subjects

E Redondo

Publications and source records attributed to E Redondo.

At least 37 records · Page 2Linked to original sources
PubMed1998

Presence of pigment in the ovine pineal gland during embryonic development.

Light- and electron-microscopic analyses were used to identify and describe the characteristic features of cells containing pigment in the ovine pineal gland during prenatal development. 72 ovine embryos (36 male, 36 female) ranging in age from 54 to 150 days were used for this study. Cells containing pigment granules were a constant feature in this gland. When samples from the different groups were inspected using the naked eye, the detection of pigment was of 61% in groups I (54 to 67 days of prenatal development) and II (71 to 92 days of prenatal development), 83% in group III (98 to 113 days of prenatal development) and 25% in group IV (118 to 150 days of prenatal development). The morphological features and histochemical properties of the pineal pigment enabled it to be identified as melanin. Several types of pigment granules were ultrastructurally distinguished; these varied in size, shape and location within pineal cell populations. The pigment granules were detected in pinealocytes, interstitial cells and pigmented cells. The largest amount and the widest variety of pigmented granules were found in pigmented cells. The presence of cells containing pigmented granules amongst the cell populations of the developing ovine pineal gland was analysed and compared with that of other mammalian species.

Animals↗
PubMed1998

Thyroid function in acute pancreatitis.

OBJECTIVES: To analyze changes in the thyroid function in patients with acute pancreatitis. METHODS: Admission serum levels of triiodothyronine (T3), reverse triiodothyronine (rT3), thyroxine (T4) and thyrotropin (TSH) were determined in 20 patients with pancreatitis and 20 healthy control patients. Another group of 20 patients with upper digestive haemorrhage was included to study possible changes in the pattern of thyroid function in hemodynamic alterations. In addition, laboratory indicators of liver, renal and pancreatic functions were measured in all groups. RESULTS: Our results demonstrated low levels of T3 in 20% of patients with pancreatitis and increased rT3 levels in 75% of them. Thyrotropin was always among reference ranges and only one case presented a low level of T4. No significant alterations were detected in patients with upper digestive haemorrhage. CONCLUSIONS: These results suggest that pancreatitis may play a role in the genesis of these changes, since other factors such as diet and cellular hepatic alteration appear to have had no effect on the levels of thyroid hormones in these patients. In other studies those changes in the thyroid function can be relationed with the prognosis in acute pancreatitis.

Acute Disease↗
PubMed1998

KI67 proliferation index in tumors of the upper urinary tract as related to established prognostic factors and long-term survival.

OBJECTIVE: Nephroureterectomy is the standard treatment for tumors of the renal pelvis and ureter. Conservative management or indication of adjuvant treatment in these neoplasms is based mainly in histological grade and stage. The aim of this study is to assess the relation of Ki67 index with other established prognostic factors and to define its predictive value for long term survival, which could be useful in selecting the best treatment for each individual case. METHODS: 81 patients with urothelial tumors of the renal pelvis and ureter, diagnosed and treated between 1975 and 1993, comprised the present study. Ki67 immunostaining was performed in paraffin-embedded tissue. A cut-off limit of 20% was chosen. Tumor location, histological grade, histological pattern, local (T), nodal (N), vascular and perineural invasion and stage (TNM) were assessed in relation to the proliferation index and as prognostic criteria for survival in both univariate and multivariate analysis. RESULTS: The Ki67 proliferation index was found to be related to grade (p < 0.001), T (T0 vs T1-4; p < 0.01), N (p < 0.038), TNM categories (stage 0 vs I-IV; p < 0.048) and perineural invasion (p < 0.01). There was a marginal relation to vascular invasion (p < 0.11). Survival was better for the patients with low proliferating tumors (90%) than for high proliferating ones (67%) (p < 0.02). In the multivariate analysis only T stage was statistically significant (p < 0.01) but a highly suggestive trend was found for the Ki67 index (p < 0.07). CONCLUSIONS: Tumor proliferation assessed by Ki67 immunostaining is related to the progression of the disease and proved to be of predictive value for long-term survival in tumors of the renal pelvis and ureter. The Ki67 index is able to detect high-risk patients that could not be cured by radical surgery alone, raising the need for some type of aduvant treatment in these cases. The treatment predictive effect observed in low grade-low stage cases suggests its possible utility in patients managed conservatively.

Adult↗
PubMed1997

Overexpression of p53 in transitional cell carcinoma of the renal pelvis and ureter. Relation to tumor proliferation and survival.

BACKGROUND: Clinical management of patients with tumors of the upper urinary tract is based mainly on histologic grade and stage of the tumors. In recent years, tumor proliferation has also proved to be an important factor in determining the prognosis of these and other transitional cell tumors. The aim of this study was to assess the role of p53 in regulating cell proliferation and tumor progression and to define its value in predicting the long term survival of patients with these tumors. Such information could be of use in selecting treatment in individual cases. METHODS: Eighty-three patients with urothelial tumors of the renal pelvis and ureter diagnosed and treated between 1975 and 1993 were included in this study. p53 immunostaining was performed on paraffin embedded tissue. Tumor location, histologic grade, histologic pattern, tumor proliferation by Ki-67, local (T classification), lymph node (N classification), vascular and perineural invasion, and clinical stage (TNM) were assessed in relation to p53 overexpression (Mann-Whitney U test and analysis of variance comparisons) and as prognostic factors for survival in both univariate analysis (log rank test) and multivariate analysis (Cox proportional hazards model). RESULTS: Overexpression of p53 was related to tumor proliferation as assessed by Ki-67 (P < 0.01), T classification (Ta vs. T1-4; P < 0.01), N classification (P < 0.054), and TNM staging (Stage 0 vs. I-IV; P < 0.01). There was also a statistically significant relation to vascular (P < 0.002) and perineural invasion (P < 0.04). Fifteen-year actuarial survival for the whole group was 75%. Patients having tumors with low p53 overexpression (< 30% of stained nuclei) had a better survival rate (88%) than those having tumors with high (> 30%) p53 overexpression (65%) (P < 0.02), and this effect reached statistical significance with high grade (P < 0.02) and infiltrating tumors (P < 0.04). Patients with low p53 and Ki-67 expression had a 15-year survival rate of 100%; in contrast, patients with overexpression of both markers had a 15-year survival rate of 61% (P < 0.003). In a multivariate analysis, only T classification (P < 0.001) and p53-Ki-67 expression (P < 0.026) were statistically significant. CONCLUSIONS: Overexpression of p53 is related to increased tumor proliferation and disease progression and is of value in determining the long term survival of patients with tumors of the renal pelvis and ureter. p53 immunostaining can be used to distinguish low risk patients in the theoretically unfavorable high grade, high stage group, and when used together with Ki-67 index, it is a predictive factor for survival.

Adult↗
PubMed1997

A combined immunohistochemical and electron microscopic study of the second cell type in the developing sheep pineal gland.

Ultrastructural and immunohistochemical techniques were used to study the second cell type in sheep embryo pineal glands. Thirty-two embryos were studied from day 54 of development through birth. Specimens were arranged in four age groups, defined in terms of the most relevant histological features: Group 1 (54-67 days of prenatal development), Group 2 (71-92 days), Group 3 (98-113 days), and Group 4 (118-150 days). At 98 days, a second cell type was observed which differed from pinealoblasts and showed uniform ultrastructural characteristics similar to those of astrocytes in the central nervous system. Ultrastructural homogeneity was not matched by the results of histochemical and immunohistochemical analysis: while all Type II cells stained positive to phosphotungstic acid hematoxylin, only 50% expressed glial fibrillary acidic protein. In the course of ovine intrauterine development, the vascular affinity of this second cell population, composed of glial-like or astrocytic cells at varying stages of maturity, leads to the formation of a limiting pineal barrier. This barrier may constitute the morphological expression of a hypothetical functional involvement in the exchange of substances between blood and pineal parenchyma.

Animals↗
PubMed1996

Central venous catheter infections in AIDS patients receiving daily home therapy for cytomegalovirus disease.

We studied the infection rate of long-term intravenous access used for daily home treatment of cytomegalovirus (CMV) disease in 61 AIDS patients who had 75 central venous catheters implanted for antiviral maintenance therapy between February 1989 and December 1994. In 39 patients (64%) the risk factor for AIDS was intravenous drug abuse. Sixty-three catheters were Hickman type and 12 were totally implanted ports. The cumulative follow-up time was 19000 catheter-days (52 patient-years), with median duration of placement of 249 days. The infection rate was 0.22 infections per 100 catheter days. The probability of remaining free of catheter-related sepsis was 58% at 6 months. In 25 cases (61%) antimicrobial therapy without catheter removal was successful. Three patients died because of a catheter-related infection (mortality rate 7.3%). Infection-free survival time was not related to the risk factor for AIDS (p = 0.44) or type of device (p = 0.41). The total infection rate in these patients receiving daily home maintenance therapy for CMV disease through a long-term catheter was similar to that in other AIDS patients receiving weekly treatment in hospital facilities.

Acquired Immunodeficiency Syndrome↗
PubMed1996

[Comparative ontogenic analysis of the epithelium of the non-glandular stomach compartments of merino sheep].

A total of 74 embryos and fetuses were used in a comparative analysis of the epithelium of the non-glandular stomach compartments of merino sheep during development. The mechanical protection showed by the tegumentary epithelium in the superficial layers of the rumen, reticulum and omasum is supported by a buffer system of neutral mucopolysaccharides secreted by the deeper strata. Neutral mucopolysaccharides first appeared in epithelial cells at 46 days of fetal life. Acid mucopolysaccharides, mucins, and mucoid compounds were not detected. Growth curves and formulas were constructed for the epithelial layers.

Animals↗
PubMed1996

Pathological study of experimentally induced bovine respiratory syncytial viral infection in lambs.

An experimental model was designed to characterize lesions in the lung of lambs inoculated with bovine respiratory syncytial virus (BRSV). Twenty-five Merino lambs of both sexes, with a live weight of 17 +/- 3 kg, received an intratracheal inoculation of 20 ml saline solution containing 1.26 x 10(6) TCID50 BRSV (strain NMK-7) per ml. Lambs were slaughtered 1, 3, 7, 11 and 15 days postinoculation (DPI), and samples were taken for analysis using light-microscopic and immunohistochemical techniques. The results reflected the effect of the virus on airway epithelia. The presence of BRSV in ciliated bronchial and bronchiolar epithelial cells gave rise to cytopathological changes, including loss of cilia and cell necrosis; these changes might be expected to decrease the efficiency of mucociliary clearance, favouring the development of secondary bacterial bronchopneumonia. These results suggest a reduction in BRSV tropism for alveolar epithelia compared to bronchial and bronchiolar epithelia. Light-microscopic analysis revealed a narrowing of alveolar and airway lumina and a considerable interstitial inflammatory reaction.

Animals↗
PubMed1996

Prenatal development of the sheep pineal gland: an ultrastructural study.

The ultrastructure of the pineal gland of 32 sheep embryos was studied from day 54 of development through birth. Embryos were arranged in four age-groups, defined in terms of the most relevant histological features: group 1 (54 to 67 days of prenatal development), group 2 (71 to 92 days), group 3 (98 to 113 days), and group 4 (118 to 150 days). A primary cell type, designated the pinealoblast, was observed from 54 days until birth; ultrastructurally, this cell was found to contain all the organelles required for hormone synthesis. A second cell population, classified as interstitial cells by virtue of their location among pinealoblasts, appeared at 78 days gestation and persisted until birth. Interstitial cells were scarce and exhibited tropism for the perivascular space. From 118 days gestation until birth, a third cell type, termed the pigmented cell, was visible. Pigmented cells, whose ultrastructural characteristics differed from those of pinealoblasts, contained a large number of pigment granules of varying size and shape. The pineal gland of developing sheep embryos showed considerable innervation and abundant vascularization; this, together with certain ultrastructural characteristics, suggests that the gland has a secretory function in uterine life.

Animals↗
PubMed1995

Lesions in lambs experimentally infected with bovine respiratory syncytial virus.

An experimental model was designed to characterize lesions in the lung of lambs inoculated with bovine respiratory syncytial virus (BRSV). 25 Merino lambs of both sexes, with a live weight of 17 +/- 3 Kg, received an intratracheal inoculation of 20 ml saline solution containing 1.26 x 10(6) TCID50 BRSV (strain NMK-7) per ml. Lambs were slaughtered 1, 3, 7, 11 and 15 postinoculation days (PID), and histopathological, immunohistochemical and electron microscopic studies were performed. Results reflected a series of lesions, the most noteworthy of which were bronchiolitis obliterants with destruction of the mucociliary apparatus, the presence of syncytial cells in alveoli and a progressive interstitial reaction. BRSV antigen was detected in lung samples. These changes might be expected to decrease the efficiency of respiratory tract defence mechanisms, rendering the lung parenchyma susceptible to opportunist bacterial infection.

Animals↗
PubMed1994

Spontaneous bovine respiratory syncytial virus infection in goats: pathological findings.

This paper presents the results of a study of eight cases of natural bovine respiratory syncytial virus (BRSV) infection in a herd of 50 Murciana kids from a intensive goat-farm in Spain. Clinical and pathological analysis confirmed the existence of natural BRSV infection in eight kids. In two of the eight animals there was also evidence of concurrent infection with P. haemolytica A.

Animals↗
PubMed1993

A new technique for accessing the cerebral ventricles of the horse.

A technique is described for catheterisation of the ventricular recess within the olfactory bulb of the horse. Twelve adult horses were used. The olfactory recess is in the frontal region, 42 +/- 3 mm below the skin, on the line joining the supraorbital foramina, and approximately 18 +/- 2 mm from the midline. The approach is relatively easy under normal experimental conditions.

Animals↗
PubMed1993

Histomorphometric analysis of the abomasum of the sheep during development.

Histomorphometric analyses were carried out on 64 embryos and fetuses and on 20 sheep (early postnatal to adult age). Histodifferentiation of the abomasum took place at 33 days of fetal life, with the appearance of abomasal villi at 53 days. By 64 fetal days, the epithelium had changed from pseudostratified to simple mucous cylindrical. Acidic glycoproteins appeared at 46 fetal days. Neutral glycoproteins did not appear until later stages of development, near birth. We believe that the configuration of a simple epithelium with acidic secretion is enhanced at birth by the secretion of neutral glycoproteins which act as a buffer against acidic substances, and particularly against the abomasal acidity during lactation. Growth curves and formulae were set out for each tissue layer.

Abomasum↗
PubMed1993

Changes in the coxofemoral articular cartilage in Wistar rats after systemic administration of corticoids.

A structural, ultrastructural and morphometric study of the coxofemoral articular cartilage of 48 Wistar rats was carried out after daily intramuscular injections of 2.5 mg prednisolone. The animals were divided into four groups, members of which were killed 15, 30, 60 and 90 days respectively after the start of the experiment. A degenerative process developed in the experimental animals, which led progressively to the death of chondrocytes in the middle zone of the articular cartilage after 90 days. Structural, ultrastructural and morphometric alterations were observed, both in cells and in the cartilage matrix. These gave rise to superficial changes in the femoral head.

Animals↗
PubMed1993

The immunologic response to experimental infection with bovine respiratory syncytial virus in lambs.

An experimental model was designed to study the humoral immune response in lambs experimentally infected with bovine respiratory syncytial virus (BRSV), 25 Merino lambs of both sexes, with a live weight of 17 +/- 3 kg, received an intratracheal inoculation of 20 ml. saline solution containing 1.26 x 10(6) TCID50 BRSV (strain NMK-7) per ml. Blood samples for serological analysis were collected from the jugular vein of the animals on days 0, 1, 3, 5, 7, 9, 11 and 15 post inoculation. Serum proteins were determined by electrophoresis, and a qualitative and quantitative analysis of immunoglobulins (Ig) was carried out using immunoelectrophoresis (IE) and light nephelometry, respectively. Serum anti-BRSV antibody levels were tested by enzyme-linked immunoabsorbent assay (ELISA). Lambs were necropsied 1, 3, 7, 11 and 15 postinoculation days (p.i.d.), and samples were taken for immunohistochemical analysis. IgA, IgG and IgM were labelled on paraffin-embedded lung sections using an avidin-biotin-peroxidase complex. Results reflected an increase in gamma fractions in experimental animals with respect to controls. IE analysis of these sera revealed a polyclonal increase in immunoglobulins. Nephelometric examination showed an increase in serum IgA, IgG an IgM levels up to 7 p.i.d., coinciding closely with high titres for humoral virus antibodies. After 9 p.i.d., titres and immunoglobulin levels both fell. Immunoglobulin labelling in formol-fixed and paraffin-embedded lung tissue samples detected IgG and IgA, mainly in bronchial, bronchiolar and alveolar epithelia. IgM, however, was not detected in the lungs of infected animals.

Animals↗