PubMed Health⌕ Search

Biomedical subjects

L Ferrer

Publications and source records attributed to L Ferrer.

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

CD26 expression and dipeptidyl peptidase IV activity in an aggressive hepatosplenic T-cell lymphoma.

The transmembrane serine aminopeptidase dipeptidyl peptidase IV (DPP IV) (also known as CD26) participates in several immunological functions and has a binding affinity for several molecules, including collagen, which may be an integral mechanism for T cells to traverse endothelial barriers. Since CD26 is phenotypically expressed in certain T-cell malignancies, this study utilized a novel four-color cytofluorographic procedure to measure DPP IV enzymatic activity concurrently with the expression of other surface markers in an aggressive hepatosplenic T-cell lymphoma. Immunophenotypic analysis by flow cytometry revealed the tumor to be CD2+, CD3+, CD5-, CD7+, TcR-gamma/delta+, CD4-, CD8+/-, CD56+, and CD11c+. The CD26 molecule was also expressed, and DPP IV activity was present, with the maximal activity detectable after 10 min of incubation. These results represent the initial description of enzymatically active CD26 in a T-cell malignancy, and raise the possibility that this molecule may be a participant in the pathogenetic mechanisms utilized by the neoplastic cells.

Adolescent↗
PubMed1997

Epidermal immunocompetence in canine leishmaniasis.

The antigen-presenting cell function of the epidermis was investigated immunocytochemically in 16 dogs with different types of skin lesions induced by Leishmania infection. The degree of epidermal immunocompetence was evaluated according to the presence of Langerhans cells (LC) and keratinocytes expressing class II major histocompatibility complex (MHC II) molecules on the one hand, and the relative numbers of macrophages, T cells, and parasites in the dermis on the other, as described for human cutaneous leishmaniasis. In alopecic dermatitis, appropriate numbers of LC and MHC II-positive keratinocytes were shown to be associated with a mild T cell infiltration without significant numbers of parasites. By contrast, when the epidermis lacked antigen-presenting cells, as occurred in nodular lesions, macrophages and parasites massively infiltrated the dermis. Ulcerative lesions showed intermediate patterns of inflammation. These results suggest that dogs with alopecic dermatitis develop an effective control of the infection, whereas those with a generalized nodular disease mount an impaired immune response against the parasite. Skin lesions in dogs infected by Leishmania might not only have a prognostic value, but also represent a suitable model to study the natural course of human cutaneous leishmaniasis.

Animals↗
PubMed1997

Effect of H1-antihistamines on histamine release from dispersed canine cutaneous mast cells.

OBJECTIVE: Because of the implication of histamine in canine atopic dermatitis, H1-antihistamines may provide a valid alternative to glucocorticoid therapy. In vitro study of these drugs prior to clinical testing can allow the most promising compounds to be selected for trials and render trials with drugs of doubtful efficacy unnecessary. SAMPLE POPULATION: Isolated canine cutaneous mast cells. PROCEDURE: Cells were preincubated with antihistamines at increasing concentrations and incubated with concanavalin A (1,000 micrograms/ml), calcium ionophore A23187 (1 microM), and substance P (100 microM). Compound 48/80 was not used because it proved to be cytotoxic. RESULTS: Generally, significant prodegranulating effect was not observed for most of the studied agents. Only terfenadine increased spontaneous histamine release at concentrations > 30 microM. Cetirizine did not block histamine release at any of the studied concentrations. Ketotifen had a low inhibitory effect only at the highest concentration (100 microM) after concanavalin A- (23.6 +/- 2.8%) and calcium ionophore A23187- (29.8 +/- 3.0%) induced release. Terfenadine caused a concentration-dependent inhibitory effect after ionophore A23187- (48.1 +/- 2.2%) and concanavalin A- (28.9 +/- 2.3%) activation, but was inactive against substance P-induced release. In contrast, loratadine had potent dose-dependent inhibition of concanavalin A- and ionophore A23187-induced histamine release, with maximal effect of 85.6 +/- 3.1% and 62.6 +/- 4.7%, respectively, at 100 microM concentration. After substance P activation, histamine release was only slightly inhibited by loratadine (14.8 +/- 1.1%). CONCLUSIONS: This study documents the behavior of isolated canine cutaneous mast cells in the presence of nonimmunologic stimulation. Using this in vitro method, we were able to determine that loratadine is the only antihistamine that has potent inhibition of histamine release from dog cutaneous mast cells without a substantial prodegranulating effect. Loratadine is, therefore, a good candidate for clinical testing.

Animals↗
PubMed1997

[Collagenous colitis: presentation of 12 cases].

Collagenous colitis (CC) is a cause of chronic aqueous diarrhea with normal radiologic study and endoscopic appearance of the colonic mucosa. Histologically, it is defined by the presence of a thickened subepithelial collagenous band and inflammatory changes of the mucosa. The cause of CC is currently unknown, although several mechanisms have been proposed, such as an inflammatory, autoimmune, origin, disregulation in collagen synthesis, plasma vasculosis and a possible role of bacterial or drug toxins. The clinicopathological data of 12 patients (9 females and 3 males) with a mean age of 52.4 years diagnosed by histologic criteria are presented. Aqueous diarrhea was observed in all the patients with a mean number of 5.4 stools/day during a time period between 3 weeks and 10 years (mean, 14.7 months). In a 6 patients allergies and/or associated diseases, mainly rheumatologic diseases were found. Laboratory and endoscopic data were normal or unspecific, with colon biopsy being carried out in all the patients. Several treatments were tested with good response with sulphasalazine derivatives, corticoids, antibiotics, and mebeverine, with no solution to the diarrhea in 2 patients. A review of the literature is also provided.

Adult↗
PubMed1996

Skin mast cell releasability in dogs with atopic dermatitis.

Isolated dermal mast cells from atopic dogs are a valuable tool for the analysis of their functional properties in atopic dermatitis. We have characterized the histamine secretory pattern of mast cells enzymatically dispersed from the skin of dogs naturally suffering from this condition. The total histamine content found per isolated skin mast cell was higher in the allergic dogs than in nonatopic (control) animals (8.7 pg/mast cell versus 5.2 pg/mast cell). This phenomenon together with the well known higher concentration of skin mast cell number in atopic dermatitis lesions might account for the observed increase in local histamine concentration (15.0 micrograms/g versus 9.0 micrograms/g). Atopic dog-derived mast cells were highly reactive to both non-immunological (ionophore A23187) and an immunological-like (concanavalin A) stimulus. Furthermore, histamine net release induced by concanavalin A (1 mg/ml) stimulation was clearly enhanced in the atopic dogs (33.3% net release versus 15.4% in controls). These results have not been described in dermal mast cells dispersed from the skin of individuals with atopic dermatitis and clearly support the hypothesis that mast cells play a major role in causing and possibly modulating atopic dermatitis, through enhanced sensitivity or releasability. However, whether these two phenomena are primary abnormalities of atopic dermatitis, or only secondary changes, remains undetermined.

Animals↗
PubMed1996

Immunocytochemical study of the pathogenesis of Pacheco's parrot disease in budgerigars.

Thirty-five budgerigars were infected with the Psittacid herpesvirus 1 (RSL-1 strain, ATCC) to study the pathogenesis of Pacheco's disease. Intramuscular (i.m.) and oral (p.o.) infection routes were used in 21 and 14 animals respectively. Animals were euthanized on days 1, 2, 3, 4, 6 and 8 post-inoculation (p.i.) and complete postmortem examinations and histological studies were performed. The presence of viral antigen in tissues was detected by immunohistochemical techniques using a rabbit polyclonal antibody. In the i.m.-infected birds, lesions were first detected on the third day p.i. and included necrotizing hepatitis and splenitis, both associated to the presence of viral antigen. Necrotic and inflammatory lesions as well as viral antigen were detected in many organs after the fourth day p.i. (oesophagus, crop, pancreas, kidney, adrenal gland, thyroid and parathyroid glands, thymus, ovary and feathers) proving generalization of the disease. Chronology of the infection was similar in the p.o.-infected birds. However, two main differences were observed between the groups: In the p.o. group, viral antigen was first detected in cloacal mucosa (3rd day p.i.), liver and spleen; and viral entry into target cells and dissemination to the rest of the tissues was slower in this group. In addition, detection of viral antigen in feather follicular epithelial cells and in granulosa cells of organ follicles are findings that could be of relevance to the transmission of the virus.

Animals↗
PubMed1996

Geriatric patients with acute myocardial infarction: Cardiac risk factor profiles, presentation, thrombolysis, coronary interventions, and prognosis.

Elderly patients have a higher mortality after acute myocardial infarction (MI) yet are treated less aggressively than younger patients. To determine (l) the risk-factor profiles, (2) presentation, (3) management, and (4) hospital outcomes for the elderly (> or = 75 years) compared with middle aged (66 to 74 years) and younger (< or = 65 years) patients in the 1990s, we studied 561 consecutive patients with acute MI. Compared with younger patients, the elderly more frequently had congestive heart failure (40 percent vs 14 percent; p < 0.00001) and non-Q wave infarctions (76 percent vs 56 percent; p < 0.005), received thrombolysis (9 percent vs 34 percent; p < 0.0001), and underwent catheterization (35 percent vs 73 percent; p < 0.00001), percutaneous transluminal coronary angioplasty (9 percent vs 31 percent; p < 0.0002), and coronary artery bypass grafting (5 percent vs 15 percent; p < 0.03) less frequently. Those who did not receive thrombolysis all had contraindications. Mortality was higher in the elderly (19 percent vs 5 percent; p < 0.004), especially among those who did not receive thrombolysis (20 percent vs 7 percent; p < 0.03). Multivariate predictors of mortality included age, and congestive heart failure. In addition, when clinical course and management variables were considered, use of the intraaortic balloon pump was a predictor of mortality, whereas undergoing coronary angiography was a negative predictor (relative risk, 0.3; 95 percent confidence intervals, 0.1 to 0.6).

Adult↗
PubMed1996

Prevalence of antibiotics to hepatitis C in a population of intravenous drug users in Valencia, Spain, 1990-1992.

BACKGROUND: Hepatitis C has been related to other viral diseases such as the human immunodeficiency virus infection (HIV) or hepatitis B (HBV). The objective of this study was to estimate the prevalence and determinants of antibodies to hepatitis C virus (HCV) in intravenous drug users (IVDU) in Valencia (Spain) and to compare the seroprevalence between the HCV, HIV and HBV in this high risk group. METHODS: A cross-sectional study was conducted in a sample of 1056 current IVDU from the Valencia area who attended the city's AIDS Information Centre between January 1990 and December 1992. Information on sociodemographic, sexual behaviour, and drug use variables was collected by means of a structured questionnaire. Antibodies to HCV, HIV and HBV were assayed by ELISA test. RESULTS: The seroprevalence of HCV for the whole period was 85.5% (95% confidence interval [CI]: 83.2-87.5%), ranging from 76.5% in 1990 (95% CI: 71.9-81.1%) to 87.8% in 1992 (95% CI: 82.5-93.1%). Year of testing and prevalence of HBV markers showed an independent association with HCV seroprevalence. When only IVDU aged < 25 years were analysed, sharing of needles also appeared as an independent dominant. Of those IVDU with less than one year of addiction, 69% were HCV seropositive compared with 41% for HBV and 14% for HIV. CONCLUSIONS: Intravenous drug users in Valencia showed one of the highest reported hepatitis C seroprevalences (85.5%). A more efficient parenteral transmission of hepatitis C virus than HBV or HIV is suggested.

Adult↗
PubMed1996

[Splenic infarction].

A 53-year-old male suffered splenic infarction etiologically related to atrial fibrillation and non-obstructive hypertrophic cardiomyopathy. The main clinical manifestations were a one-month history of epigastric and left upper quadrant pain, with tenderness to palpation in the later zone. Laboratory tests revealed a slight leucocytosis (14.700) with left shift and a marked increase in LDH concentration (945 IU). Abdominal CAT and arteriography established the diagnosis, Echography proved normal. Patient evolution was satisfactory with conservative medical treatment. We conclude that splenic infarction should be considered in all cases of acute or chronic pain in the left hypochondrium. The diagnosis is established by CAT, arteriography and hepatosplenic gammagraphy. Medical management is initially advocated, surgery being reserved for those cases involving complications or in which diagnosis is not clear. Emphasis is placed on the main etiological, clinical, diagnostic and management characteristics of splenic infarction.

Angiography↗
PubMed1995

Serological diagnosis and treatment of canine leishmaniasis.

The changes in the titres of anti-leishmania antibodies in 25 dogs with leishmaniasis were studied by using a Dot-ELISA technique while they were being treated with N-methylglucamine and allopurinol. When the diagnosis of leishmaniasis was established, 21 of the dogs had positive titres (1:800 or higher), and after treatment, 15 of them still had high titres, in most cases the same as at the point of the diagnosis. In four dogs the titres decreased, and were less than the cut-off value in two cases nine months after treatment. Only four dogs had titres less than the cut-off value when they were diagnosed, but one month later the titres in all four dogs had reached the cut-off value. There was no correlation between the serological titres and the severity of the clinical signs. It is concluded that the Dot-ELISA is a sensitive method for the diagnosis of canine leishmaniasis but is not satisfactory for monitoring the clinical development of the disease.

Allopurinol↗
PubMed1995

Trends in incidence and prevalence of HIV-1 infection in intravenous drug users in Valencia, Spain.

Our objective was to describe and compare the trends of incidence and prevalence of HIV-1 infection in intravenous drug users (IDUs) in Valencia, Spain in 1987-1992. A cohort study was carried out in AIDS Information Centers located in the Valencia Region (Spain). Point seroprevalence was calculated for in each year according to HIV status at the first contact. Incidence annual rates were calculated from those IDUs identified as seronegative in their first visit and who returned for a new testing. From a total of 4,207 IDUs who contacted these centers, 4,131 (98.2%) asked voluntarily for HIV-1 testing. The seroprevalence for the whole period was 48.4% (95% C.I., 46.88, 49.92). Follow-up information was available for 604 subjects of the total 2,130 subjects who were seronegative in their first visit. The incidence rate for the 1988-1992 period was 12.02/100 person-years (95% C.I., 9.62, 14.41). Prevalence showed an overall decreasing pattern with a minimum corresponding to the year 1992 (43.6%). Incidence rates increased mildly until 1990 (13.93 per 100 person-years), to stabilize beyond at approximately 10 per 100 person-years. Our incidence rates are very high regardless of the decline of prevalence. Effective risk reduction programs among IDUs have been almost nonexistent in Spain up to now and should become an immediate priority.

Adult↗
PubMed1995

Ultrastructural co-localisation of vimentin and cytokeratin in visceral glomerular epithelial cells of dogs with glomerulonephritis.

The expression of cytokeratin and vimentin was studied in the glomerular epithelial cells of canine kidneys with and without glomerular abnormalities. Using ultrastructural, immunogold single and double labelling techniques, cytokeratin and vimentin were found together in the visceral glomerular epithelial cells (vGECs) of abnormal kidneys. In normal kidneys, the vGECs expressed only vimentin, and cytokeratin was found exclusively in parietal glomerular epithelial cells (pGECs). These results confirm previous findings in the same animals, obtained by immunohistological staining techniques.

Animals↗
PubMed1995

Immunohistochemical detection of canine leucocyte antigens by specific monoclonal antibodies in canine normal tissues.

This report describes the immunocytochemical detection and distribution of different canine leucocytes antigens (Thy-1, CD5, CD4, CD8, MHC-II and B-cell antigen) by means of monoclonal antibodies (mAbs) in frozen tissue sections of lymphoid organs of the dog. CD5 is expressed exclusively by T lymphocytes. Thy-1 is expressed by T-lymphocytes and in a variety of non-lymphoid tissues. The mAb against canine MHC-II could detect B and T lymphocytes, macrophages, fibroblasts and antigen presenting cells. The CD4 antigen is expressed on many lymphocytes of the T-dependent areas of lymph organs and is also expressed by certain antigen presenting cells. CD8 is expressed in a minor proportion of T cells. The mAb against B cells detected lymphocytes in lymphoid follicles and epithelial cells of the thymic medulla.

Animals↗
PubMed1995

Immunohistochemical detection of CD31 antigen in normal and neoplastic canine endothelial cells.

This report describes the immunohistochemical detection of von Willebrand's factor (vWf) and CD31 antigen in paraffin wax-embedded, formalin-fixed tissue sections of canine normal organs and vascular neoplasms. CD31 antigen and vWf were detected in endothelial cells of all organs examined, except for the endothelia of the renal glomeruli, which were negative for vWf. All haemangiomas examined (15) were positive for both markers. Eleven of 15 haemangiosarcomas were positive for vWf and all 15 expressed the CD31 antigen. All other neoplasms investigated (fibrosarcomas, schwannomas, haemangiopericytomas) were negative for both markers. It is concluded that immunohistochemical detection of CD31 antigen is of value for studying vascular disorders of the dog in routinely processed tissue.

Animals↗
PubMed1995

[Malignant fibrous histiocytoma in the kidney of a dog].

Malignant fibrous histiocytomas occur rarely in internal organs of dogs. Only the spleen has been demonstrated as a primary site of tumor origin. In humans, malignant fibrous histiocytomas originate frequently from any retroperitoneal organ. This case report describes the clinical disease and morphological findings in a dog with a renal malignant fibrous histiocytoma.

Animals↗
PubMed1995

[Changes in protein repletion markers in undernourished patients receiving enteral nutrition and its relation with energy and nitrogen balance].

AIM: To study the relationship between the changes in protein repletion indicators and calorie and nitrogen balance in undernourished patients receiving enteral nutrition. PATIENTS AND METHODS: Fourteen patients (11 female, age range 55-85 years old) with an initial serum albumin below 3.5 g/dl or serum transferrin below 200 mg/dl, which received enteral nutrition, were studied. On days one and ten of nutritional support, indirect calorimetry, nitrogen balance and serum levels of albumin, transferrin, pre-albumin and total lymphocyte count were measured. RESULTS: Initial resting energy expenditure was 25.1 +/- 5 Kcal/kg/day (115.4 +/- 20% of that predicted by Harris Benedict equations) and urinary urea nitrogen 5.4 +/- 3.7 g/day. Initial and final nitrogen balances were 66.9 +/- 71 and 81.4 +/- 105.9 mg N/kg/day and mean energy balance throughout the study was +9.0 +/- 7.2 Kcal/kg/day. During the ten days of nutritional support, albumin improved significantly in 0.35 +/- 0.43 g/dl (15.2 +/- 19.8%). Transferrin, pre-albumin and total lymphocyte count did not change significantly. The changes in these last parameters did not correlate with nitrogen or calorie balance. CONCLUSIONS: Probably other factors, besides nutritional balances, influence serum protein levels and these may not change despite an adequate nutritional repletion.

Aged↗