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Biomedical subjects

F U Garcia

Publications and source records attributed to F U Garcia.

23 records · Page 2Linked to original sources
PubMed1991

Bartonellosis. An immunodepressive disease and the life of Daniel Alcides Carrión.

The history of human Bartonellosis, a unique South American biphasic bacterial disease, is reviewed. The course of this disease and its natural history offer many puzzling problems. Its geographic distribution, its absence of a natural reservoir, the development of transient immunosuppression during the acute hematic phase, and the subsequent development of vascular proliferations are highlighted. These vascular proliferations represent a unique example of tissue reactivity recalling the vascular proliferations of patients with AIDS. In addition, the authors review the life and times of Daniel Alcides Carrión, a Peruvian medical student who in 1885 by self-experimentation linked both phases of the disease and died in doing so. Carrión's life, and the impact of his experiment on the subsequent study of Bartonellosis by Peruvian and international scholars, epitomize the constant struggle of the Peruvian medical profession (past and present) to upgrade domestic biomedical research and to find a national identity.

Bartonella Infections↗
PubMed1990

Bartonella bacilliformis stimulates endothelial cells in vitro and is angiogenic in vivo.

Bartonellosis, a biphasic disease caused by motile intracellular bacteria, produces in its tissue phase a characteristic dermal eruption (Verruga peruana) resulting from a pronounced endothelial cell proliferation. Bacteria are found in the interstitium and within the cytoplasm of endothelial cells (Rocha-Lima inclusion). The aim of this study was to determine if Bartonella bacilliformis produce a substance(s) that might be responsible for the vascular proliferation seen in the Verruga. This was assessed in an in vitro system using human endothelial cells and measuring proliferation as well as production of tissue type plasminogen activator after exposure to the endothelial cultures to B. bacilliformis extracts. Our results indicate that B. bacilliformis possess an activity that stimulates endothelial cell proliferation up to three times that of control. The factor(s) is specific for endothelial cells, heat sensitive, larger than 12 to 14 kd, not enhanced by heparin, has no affinity for heparin, and is precipitated by 45% ammonium sulfate. In addition, the B. bacilliformis extracts stimulate production of t-PA antigen in a concentration-dependent fashion. This activity is also heat sensitive and not lost after dialysis (12 to 14 kd). B. bacilliformis extracts, however, do not increase the production of plasminogen activator inhibitor. It was also determined that B. bacilliformis extracts stimulate the formation of new blood vessels in an in vivo model for angiogenesis. These results describe a bacterial factor(s) that stimulates two important steps in the development of new blood vessels in vitro, as well as the formation of new blood vessels in vivo. Determining the mechanism of action, combined with a complete characterization of this factor(s), may help in understanding the pathogenesis not only of the Verruga and angiogenesis in general but also the recently described Cat-Scratch-associated epithelioid hemangiomas in patients with AIDS and Kaposi sarcoma.

Animals↗
PubMedDate not supplied

Focal hematopoietic hyperplasia of the rib. Report of a case diagnosed by fine needle aspiration.

BACKGROUND: Focal hematopoietic hyperplasia (FHH) of the rib is a rare, benign, localized proliferation of bone marrow to such a degree that it produces a tumorlike expansion of the rib that can be the source of considerable clinical alarm. In the appropriate clinical setting, this lesion needs to be included in the differential diagnosis of solitary bone lesions, in particular when assessing the adequacy of a specimen at the time of aspiration. CASE: A large, lytic mass on the posterior aspect of the sixth rib was incidentally discovered on a chest roentgenogram from a 46-year-old male during a routine presurgical evaluation for diverticulitis. The radiologic characteristics of the tumor were thought to be consistent with a neoplasm; that prompted a recommendation for fine needle aspiration biopsy (FNAB). The mass was thoroughly sampled under radiologic guidance, performing multiple aspirations of different areas. All smears prepared at the time of the aspiration for the evaluation of specimen adequacy showed abundant marrow tissue without any evidence of malignancy. Although it was initially thought that the tissue was probably obtained from the periphery of the lesion, this notion was discarded after multiple passes from different areas showed only marrow tissue and since there was radiologic evidence that the sample was obtained from within the lesion. CONCLUSION: The diagnosis of FHH of the rib by FNAB or other small-biopsy techniques requires strict radiologic-pathologic correlation. Awareness of this entity will avoid unnecessary repeated biopsy procedures and potentially large, complicated surgical procedures. This case shares several features with the other two reported cases: a solitary lesion on the rib presenting in an asymptomatic patient with no evidence of associated hematologic disease.

Biopsy, Needle↗