Biomedical subjects

Miguel Caballero

Publications and source records attributed to Miguel Caballero.

8 recordsLinked to original sources

PubMed2005

Therapeutic immunization with dendritic cells loaded with heat-inactivated autologous HIV-1 in patients with chronic HIV-1 infection.

Therapeutic immunization with autologous monocyte-derived dendritic cells (DCs) loaded with heat-inactivated autologous human immunodeficiency virus type 1 (HIV-1) in 12 patients with chronic HIV-1 infection who were receiving highly active antiretroviral therapy (HAART) was feasible, safe, and well tolerated. Virus was obtained during an initial interruption of HAART (hereafter, "stop 1") so that DCs could be pulsed. After immunization and a second interruption of HAART (hereafter, "stop 2"), set-point plasma viral load (PVL; 24 weeks after stop 2) decreased > or =0.5 log(10) copies/mL relative to baseline PVL in 4 of 12 patients. We observed a significant lengthening in mean doubling time of PVL rebound and significant decreases in the area under the curve and the mean peak of PVL rebound after stop 2, compared with those after stop 1. This response was associated with changes in HIV-1-specific CD4(+) lymphoproliferative and CD8(+) T cell responses. These changes were not observed in a group of nonimmunized control patients.

AIDS Vaccines↗

PubMed2005

Immunoarchitecture of lymphoid tissue in HIV-infection during antiretroviral therapy correlates with viral persistence.

Plasma viral load and T-cell subset determinations in blood are the markers used for monitoring HIV-1 infection. However, key pathogenesis events, viral replication and most immunologic changes occur in the lymphoid tissues. We have studied the tonsillar biopsies of 30 patients in the early stages of the disease, before initiating treatment and after 12 and 36 months of fully effective highly active antiretroviral therapy. We have investigated the HIV RNA by polymerase chain reaction (lymphoid tissue viral load), the immunohistochemical HIV-p24 antigen expression, as well as the lymphoid tissue architecture and lymphoid cell subsets using morphometry. The lymphoid tissue viral load and the immunoexpression of p24, which was found to be mainly associated with follicular dendritic cells, decreased significantly after treatment, but did not disappear in all cases, even after 36 months of treatment. A significant improvement of the lymphoid tissue architecture was also observed after treatment, with recovery of follicular structures. These histological changes correlated with the lymphoid tissue viral load. Moreover, the counts of CD4+ increased whereas CD8+ and cytotoxic lymphocytes (CD8+ granzyme B+) decreased significantly, the latter in both interfollicular and intrafollicular areas. However, these cellular counts after treatment did not reach those of lymphoid tissue of non-HIV-infected patients used as control cases. Naive (CD45RA+) and memory (CD45RO+) cells also improved significantly after treatment. In conclusion, in HIV-infection the impact of treatment can only be assessed completely in the lymphoid tissue reservoir, where most of the virus is stored and associated with follicular dendritic cells. Highly active antiretroviral therapy produces a significant recovery of lymphoid tissue architecture and lymphoid cell subsets, which are associated with the decrease of lymphoid tissue viral load. However, these parameters studied in lymphoid tissue are not re-established completely, even after 36 months of highly active antiretroviral therapy.

Adult↗

PubMed2005

Epiglottitis and necrotizing fasciitis: a life-threatening complication of infectious mononucleosis.

Life-threatening cervical complications associated with infectious mononucleosis are rare. The combination of acute epiglottitis and subsequent necrotizing fasciitis of the head and neck in a patient with infectious mononucleosis has not been reported to date.A 47-year-old female with infectious mononucleosis and epiglottitis was admitted to hospital for i.v. therapy. Owing to her poor clinical condition and the spread of the infection to the throat and superior mediastinum, as evidenced by CT, a cervical debridement was performed. After cervical debridement, histological findings were consistent with necrotizing fasciitis. The bacteria identified were Streptococcus viridans, Veilonella spp. and Capnocytophaga spp. The patient was hospitalized for 33 days.Mononucleosis, usually a benign condition, may be associated with life-threatening septic complications in the neck and chest. Serial CT or MRI scans are necessary to assess the development of the infection in the deep layers of the neck. Rapid medical treatment, extensive surgical debridement and intensive care are vital.

Capnocytophaga↗

PubMed2005

Expression of membrane-bound mucins (MUC1 and MUC4) and secreted mucins (MUC2, MUC5AC, MUC5B, MUC6 and MUC7) in mucoepidermoid carcinomas of salivary glands.

Mucins are glycoproteins normally synthesized by a variety of secretory epithelial cells. The aim of this study was to investigate the expression of mucins (MUC1, MUC2, MUC4, MUC5AC, MUCB, MUC6, MUC7) in mucoepidermoid carcinomas, the most frequent malignant tumor of salivary glands. Forty mucoepidermoid carcinomas and twenty-two normal salivary glands were studied for these mucins by immunohistochemistry from formalin-fixed and paraffin-embedded material. Normal salivary glands frequently expressed MUC1 and MUC4, mainly in ductal cells; MUC5B and MUC7 stained mucous and serous acini respectively of submandibular and minor salivary glands; and MUC5AC and MUC2 were poorly detected in excretory ducts. All mucoepidermoid carcinomas expressed MUC1, and 38/40 tumors expressed MUC4. Both membrane-bound mucins stained membranes and cytoplasm of all cell types (epidermoid, intermediate, mucous, clear and columnar). MUC5AC and MUC5B stained glandular differentiated cells in most tumors (29/40 and 33/40 cases, respectively). MUC6 was positive in 13/40 tumors, and both MUC2 and MUC7 in only 2/40 tumors. The high expression of MUC1 was related to high histologic grades, high recurrence and metastasis rates and a shorter disease-free interval (P < 0.05). Conversely, MUC4 high expression was mainly related to low-grade tumors, lower recurrence rates and a longer disease-free interval (P < 0.05). In conclusion, mucoepidermoid carcinomas of salivary glands usually express MUC1, MUC4, MUC5AC and MUC5B; less frequently MUC6; and rarely MUC2 and MUC7. This mucin expression pattern can be useful for diagnostic purposes. Therefore, MUC1 expression is related to tumor progression and worse prognosis, whereas MUC4 expression is related to a better prognosis.

Adolescent↗

PubMed2004

Particulate silicone for vocal fold augmentation: morphometric evaluation in a rabbit model.

To study the augmentation of the paralyzed vocal fold in response to the injection of particulate plastics in a rabbit model, we performed a prospective, experimental, and controlled study in 45 New Zealand rabbits with surgical vocal fold paralysis. We compared a control group (acute unilateral recurrent nerve section) with a group that underwent polytetrafluoroethylene (PTFE) injection and with another group that underwent polydimethylsiloxane (PDMS) injection. Equal volumes of implant material were injected. The animals were killed either 6 weeks or 6 months after intervention and compared by histomorphology using a digital measuring system. The injection sites showed a substantial foreign body giant cell reaction against the PDMS and PTFE, surrounded by a light, fibrous stroma. No differences in the frequency of displacement or disaggregation of implants were observed. No extrusion to the laryngeal lumen, signs of migration outside the larynx, or malignant changes were seen. No differences were found in the length of the vocal fold between the PDMS group and the PTFE group. The vocal fold was thicker in the PDMS group than in the PTFE group, but a statistically significant difference was found only for the anterior and middle thirds at 6 weeks. In the PDMS sample, the thicknesses were similar in the 6-week and 6-month subgroups. The group with injection of PDMS yielded histologic images compatible with greater and more stable medialization than did the group with injection of PTFE.

Animals↗

PubMed2003

Polydimethylsiloxane versus polytetrafluoroethylene for vocal fold medialization: histologic evaluation in a rabbit model.

The objective is to study the tissue reaction of the paralyzed vocal cord in response to the injection of particulate plastics in a rabbit model. Forty-five New Zealand rabbits with surgical vocal-fold paralysis were used in the study. Histologic reactions of the larynx and the regional lymph nodes were analyzed by a single blinded pathologist at 6 weeks and 6 months after a vocal-cord injection of Teflon or of silicone elastomer. Macroscopic studies of the liver, lungs, spleen, kidney, and brain were performed. The histological study showed a greater proportion of chronic granulomatous inflammation in animals injected with silicone than in those injected with Teflon. The immunohistochemical study showed a higher degree of phagocytosis of Teflon particles than of the silicone particles. The silicone group presented a more severe fibrous reaction than the Teflon group, but the difference was not significant. No migration particles were found. It is concluded that silicone, having a greater viscosity than Teflon because of the size of its particles, induces more fibrosis and a larger proportion of foreign giant cells in the host. Due to this histological reaction, silicone particles present greater anchorage and stability.

Animals↗

PubMed2003

Autologous elastic cartilage for laryngoplasty: histologic evaluation in a rabbit model.

A wide range of materials have been used to achieve medialization of the paralyzed vocal fold. Recently, medialization techniques using autologous cartilage have been described, but little information is available on cartilage integration and viability in this situation. In this prospective, experimental, controlled study, right vocal fold paralysis was surgically induced in 30 New Zealand rabbits. An autologous auricular cartilage transplant was inserted in the vocal fold in 15 animals. In the control group, only the laryngeal nerve was sectioned. Each group was divided into two groups with follow-ups of 6 weeks and 6 months, respectively. Histologic studies revealed no inflammatory reaction against the cartilage transplants. There were no differences in the transplant surfaces in the 6-week and 6-month groups. The results show tissue integration and a low level of initial transplant resorption that stabilizes with time. Autologous auricular cartilage appears to be an appropriate material for type I thyroplasty procedures because of the low absorption rate.

Animals↗

PubMed2003

Predictors of tonsillar tissue HIV-1 viral burden at baseline and after 1 year of antiretroviral therapy.

In 81 antiretroviral-navie HIV-1 chronic-infected patients, we found a correlation among tonsillar tissue viral load, and virological and immunological measures in blood at baseline. No correlation was observed after 1 year of antiretroviral therapy. A protease inhibitor-containing regimen was the best predictor of good tonsillar tissue virological response.

Acquired Immunodeficiency Syndrome↗