RESUMO
BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disease resulting in systemic microvascular thrombosis. The disease is caused by excessive platelet (PLT) adhesion to ultra-large (UL) von Willebrand factor (VWF) multimers inadequately cleaved by the processing enzyme ADAMTS-13. While many cases respond to plasma exchange performed with or without concurrent corticosteroids, treatment of the 10% to 20% of patients with refractory disease is difficult. Experimental studies demonstrating that N-acetylcysteine (NAC) inhibits PLT binding to endothelial cell-secreted and anchored UL VWF multimers suggest that NAC may be useful in the treatment of TTP. CASE REPORT: A 44-year-old woman presented with malaise, confusion, chest and abdominal pain, and transient visual loss. Laboratory results and peripheral blood smear were consistent with TTP. The patient was begun on plasma exchange and corticosteroid treatment, but after 10 days the PLT count was still less than 10.0 × 10(9) /L and she developed a fever. Rituximab was initiated, but the patient's condition worsened and she became comatose. Antibiotics were initiated, but cultures remained sterile. After 3 days of coma and further clinical deterioration, treatment with NAC was begun. The patient received a loading dose of 150 mg/kg NAC intravenously (IV) over 1 hour. Within 18 hours the patient awakened abruptly and began communicating with medical personnel. Plasma exchange, corticosteroids, rituximab, and NAC infusion (150 mg/kg IV over 17 hr daily × 10 days) were continued and by Day 17 the PLT count was more than 50 × 10(9) /L. The patient fully recovered and was discharged on Day 31. CONCLUSION: This is the first complete report of a TTP patient treated with NAC. NAC was a safe and effective supplementary treatment for refractory TTP in this patient.
Assuntos
Acetilcisteína/uso terapêutico , Púrpura Trombocitopênica Trombótica/tratamento farmacológico , Proteínas ADAM/sangue , Proteína ADAMTS13 , Adulto , Feminino , Humanos , Contagem de Plaquetas , Púrpura Trombocitopênica Trombótica/sangueRESUMO
Plasmablastic lymphoma (PBL) is a rare subtype of diffuse large B cell lymphoma (DLBCL), often associated with HIV infection. We present a case of a 53-year-old HIV-negative man with untreated hepatitis C viral infection who presented with abdominal pain and lymphadenopathy. Lymph node and bone marrow biopsies were consistent with plasmablastic lymphoma. He had partial response (PR) to 6 cycles of EPOCH but disease progressed seven weeks later. Repeat biopsy was consistent with plasmablastic lymphoma. Three cycles of bortezomib, ifosfamide, carboplatin, and etoposide (B-ICE) chemotherapy resulted in a partial response (PR). Five months later, he presented with widespread lymphadenopathy and tumor lysis syndrome with circulating blasts. Flow cytometry revealed a different population of lymphoma cells, this time positive for CD5, CD19, CD20, and CD22, with dim expression of CD45 and CD38. The patient died on the first day of ESHAP chemotherapy. There are no treatment recommendations or standard of care for plasmablastic lymphoma. A literature search yielded 10 cases in which bortezomib was administered in either HIV-positive or HIV-negative PBL. Six reported a partial response, 3 reported a complete response, and 1 was a near-complete response. Bortezomib, in combination with chemotherapy, may be an effective treatment option in PBL as reported here.
RESUMO
When 2-butoxyethanol (2-BE) is administered to rats, hemolysis occurs as the active metabolite butoxyacetic acid (BAA) is formed. Human red blood cells appear to be relatively resistant to the hemolytic effects of BAA in vitro, whereas rat red blood cells undergo changes in deformability, cell swelling, and hemolysis. In this study, exposure of human red blood cells to high concentrations of BAA resulted in loss of deformability and a small increase in mean cellular volume, but no significant hemolysis. These changes resembled the changes that occur in rat erythrocytes exposed to much lower concentrations of BAA. Therefore, a comparison was made between the sub-hemolytic effects of BAA at high concentrations (up to 10 mM) on human red cells with the sub-hemolytic effects of lower concentrations of BAA (up to 0.1 mM) on rat erythrocytes. Under these conditions, human and rat erythrocyte deformability decreased, while mean cellular volume (MCV) and osmotic fragility increased. Although there was a substantial shift in rat erythrocytes to lower densities, human erythrocyte density was only slightly decreased. Human and rat erythrocyte sodium also increased. Rat erythrocytes demonstrated increased spherocytosis. In a survey of blood samples from adults and children, none demonstrated an increase in hemolysis (n = 97) or MCV (n = 65) after exposure to 10 mM BAA for 4 h. In these experiments, in which hemolysis was not evident, human erythrocytes required exposure to a 100-fold greater concentration of BAA to develop changes in red cell deformability, osmotic fragility, and sodium content similar to those observed in rat erythrocytes. These concentrations are not likely to occur under normal human use of 2-BE-containing products.
Assuntos
Eritrócitos/metabolismo , Glicolatos/toxicidade , Hemólise/efeitos dos fármacos , Animais , Cátions/sangue , Tamanho Celular/efeitos dos fármacos , Densitometria , Eritrócitos/efeitos dos fármacos , Eritrócitos/ultraestrutura , Filtração , Humanos , Técnicas In Vitro , Microscopia de Contraste de Fase , Fragilidade Osmótica/efeitos dos fármacos , RatosRESUMO
We describe an HIV-infected 44-year-old man who presented 1 month after discontinuation of HAART therapy with a large mass extending from the mediastinum, enclosing the heart and extending through the diaphragm to the epigastric region. Biopsies subsequently revealed a highly aggressive non-Hodgkin's lymphoma (NHL) producing sheets of cells with an organoid distribution. The cells had abundant basophilic cytoplasm and a plasmacytic appearance. Although immunohistochemistry failed to show either B- or T-cell markers, antigens consistent with plasma cells were found. An immunoglobulin heavy chain clonal rearrangement was identified by PCR analysis. These studies were supportive of a diagnosis of a plasmablastic lymphoma. While awaiting the results of these tests, the patient was reinitiated on his HAART regimen. He was found on follow-up a month later to have complete resolution of his bulky mediastinal mass. He remained free of disease for 3 months with subsequent rectal and abdominal recurrence. Treatment with CHOP chemotherapy with filgrastim support was begun which resulted in another remission. Plasmablastic lymphoma is now reported in some studies to account for 2.6% of all HIV-related NHL. Originally described in 1997 in a series of 16 patients, this entity is highly associated with HIV infection in its later stages. Often, patients present with oral or jaw lesions with a rapidly progressive course. The tumors have the morphologic appearance of a plasmacytoid tumor with high proliferative index. Markers are positive mainly for LCA, CD79a, VS38C, and CD138. Co-infection with HHV-8 and EBV has not been consistently reported. Therapy with standard regimens has variable response. One case has been reported with a 3.5 year disease free survival. The regression of disease after resumption of HAART therapy alone in this patient suggests that HAART has an important role in the treatment of lymphoma in the HIV infected patient.
Assuntos
Fármacos Anti-HIV/administração & dosagem , Linfoma Relacionado a AIDS/tratamento farmacológico , Adulto , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Humanos , Linfoma Relacionado a AIDS/diagnóstico , Linfoma de Células B/diagnóstico , Linfoma de Células B/tratamento farmacológico , Linfoma de Células B/virologia , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/virologia , Masculino , Indução de RemissãoRESUMO
Understanding the process by which red cell precursors lose their nuclei developed in the late 19th and early 20th centuries led to the identification of nuclear remnants in circulating red cells in certain pathological states, particularly absence or decreased function of the spleen. William Howell, an American, and Justin Jolly, a Frenchman, were among a number of early contributors to this field. Early on, their names were applied, singly or in tandem, to these red cell inclusions, and the eponym, Howell-Jolly bodies, has stuck. It was, however, not until after the mid-20th century that Howell-Jolly bodies were clearly differentiated from basophilic stippling and that the mechanisms of their formation and removal from red cells were understood.
Assuntos
Inclusões Eritrocíticas , Hematologia/história , Animais , França , História do Século XIX , História do Século XX , Humanos , Estados UnidosRESUMO
PURPOSE: To determine which internal medicine (IM) clerkship characteristics are associated with better student examination performance. METHOD: The authors collected data from 17 U.S. medical schools (1,817 students) regarding characteristics of their IM clerkships, including structural characteristics, pedagogical approaches, patient contact, and clinical teacher characteristics. Outcomes of interest were postclerkship National Board of Medical Examiners (NBME) subject examination score, United States Medical Licensing Examination (USMLE) 2 score, and change in score from USMLE 1 to 2. To examine how associations of various clerkship characteristics and examination performance may differ for students of different prior achievement, the authors categorized students into those who scored in the top (1/4) of the cohort on USMLE 1 and the bottom (1/4). The authors conducted analyses at both the school and the individual student levels. RESULTS: In school-level analyses (using a reduced four-variable model), independent variables associated with higher NBME subject examination score were more small-group hours/week and use of community-based preceptors. Greater score increase from USMLE 1 to 2 was associated with students caring for more patients/day. Several variables were associated with enhanced student examination performance at the student level. The most consistent finding was that more patients cared for per day was associated with higher examination performance. More structured learning activities were associated with higher examination scores for students with lower baseline USMLE 1 achievement. CONCLUSION: Certain clerkship characteristics are associated with better student examination performance, the most salient being caring for more patients per day.
Assuntos
Logro , Estágio Clínico/organização & administração , Currículo/normas , Medicina Interna/educação , Licenciamento em Medicina , Conselhos de Especialidade Profissional , Escolha da Profissão , Competência Clínica/normas , Estudos de Coortes , Docentes de Medicina , Humanos , Diretores Médicos , Relações Médico-Paciente , Preceptoria , Aprendizagem Baseada em Problemas , Estados UnidosRESUMO
Plasmablastic lymphoma is an aggressive neoplasm that shares many cytomorphologic and immunophenotypic features with plasmablastic plasma cell myeloma. However, plasmablastic lymphoma is listed in the World Health Organization (WHO) classification as a variant of diffuse large B-cell lymphoma. To characterize the relationship between plasmablastic lymphoma and plasmablastic plasma cell myeloma, we performed immunohistochemistry using a large panel of B-cell and plasma cell markers on nine cases of plasmablastic lymphoma and seven cases of plasmablastic plasma cell myeloma with and without HIV/AIDS. The expression profiles of the tumor suppressor genes p53, p16, and p27, and the presence of Epstein-Barr virus (EBV) and human herpes virus type 8 (HHV-8) were also analyzed. All cases of plasmablastic lymphoma and plasmablastic plasma cell myeloma were positive for MUM1/IRF4, CD138, and CD38, and negative for CD20, corresponding to a plasma cell immunophenotype. PAX-5 and BCL-6 were weakly positive in 2/9 and 1/5 plasmablastic lymphomas, and negative in all plasmablastic plasma cell myelomas. Three markers that are often aberrantly expressed in cases of plasma cell myelomas, CD56, CD4 and CD10, were positive in 5/9, 2/5, and 6/9 plasmablastic lymphomas, and in 3/7, 1/5, and 2/7 plasmablastic plasma cell myelomas. A high Ki-67 proliferation index, overexpression of p53, and loss of expression of p16 and p27 were present in both tumors. No evidence of HHV-8 infection was detected in either neoplasm. The only significant difference between plasmablastic lymphoma and plasma cell myeloma was the presence of EBV-encoded RNA, which was positive in all plasmablastic lymphoma cases tested and negative in all plasma cell myelomas. In conclusion, most cases of AIDS-related plasmablastic lymphoma have an immunophenotype and tumor suppressor gene expression profile virtually identical to plasmablastic plasma cell myeloma, and unlike diffuse large B-cell lymphoma. These results do not support the suggestion in the WHO classification that plasmablastic lymphoma is a variant of diffuse large B-cell lymphoma.
Assuntos
Imunofenotipagem , Linfoma/patologia , Mieloma Múltiplo/patologia , Plasmócitos/patologia , Adulto , Idoso , Antígenos CD/análise , DNA Viral/genética , Proteínas de Ligação a DNA/análise , Infecções por Vírus Epstein-Barr/imunologia , Infecções por Vírus Epstein-Barr/patologia , Infecções por Vírus Epstein-Barr/virologia , Feminino , Herpesvirus Humano 4/genética , Herpesvirus Humano 8/genética , Humanos , Imuno-Histoquímica , Hibridização In Situ , Antígeno Ki-67/análise , Linfoma/imunologia , Linfoma/virologia , Linfoma Relacionado a AIDS/imunologia , Linfoma Relacionado a AIDS/patologia , Linfoma Relacionado a AIDS/virologia , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/virologia , Plasmócitos/imunologia , Plasmócitos/virologia , Reação em Cadeia da Polimerase , Proteínas Proto-Oncogênicas/análise , Proteínas Proto-Oncogênicas c-bcl-2/análise , Proteínas Proto-Oncogênicas c-bcl-6 , Fatores de Transcrição/análise , Proteína Supressora de Tumor p53/análiseRESUMO
Pappenheimer is credited with describing the intraerythrocytic collections of iron, or siderotic granules, as they appear on Wright-stained blood smears of certain patients after splenectomy. The history of their description and elucidation of their origin and disposition shows the interaction of morphology with the increasing understanding of red cell physiology in the mid-twentieth century.
Assuntos
Grânulos Citoplasmáticos , Eritrócitos/ultraestrutura , Hematologia/história , Anemia Sideroblástica/sangue , Eritrócitos/fisiologia , História do Século XX , HumanosRESUMO
We investigated the effects of sickle erythrocytes on the production of vasotone mediators in endothelial cells (ECs) using an in vitro recirculating flow system. Sickle erythrocytes increased the EC production of two important vasoactivators, prostacyclin and endothelin-1, under venous wall shear stress conditions of 1dyncm2. The presence of interleukin-1 in the perfusion system, as a model for inflammatory cytokine effects, enhanced the overall amounts of released prostacyclin but did not affect the production of endothelin-1. This study demonstrates the effects of sickle erythrocytes on the function and metabolism of ECs under vascular flow environments. The altered production of vasoactivators may contribute to the vasotone instability and vasoocclusive crises in sickle cell anemia.
Assuntos
Anemia Falciforme/sangue , Endotelina-1/biossíntese , Endotélio Vascular/metabolismo , Epoprostenol/biossíntese , Eritrócitos Anormais/fisiologia , 6-Cetoprostaglandina F1 alfa/biossíntese , Adulto , Células Cultivadas , Hemólise , Hemorreologia , Humanos , Interleucina-1/farmacologia , CinéticaRESUMO
BACKGROUND: Changes in academic medicine have left clerkship directors (CDs) anxious about their career pathway, because clerkship administrative efforts may detract from other activities. PURPOSE: The Clerkship Directors in Internal Medicine (CDIM) asked members about benefits of being a CD or CDIM membership toward career development. METHODS: Responses were on 1-5 Likert scales with 5 (strongly agree). Background and demographic issues were analyzed for associations with the career benefits statements. RESULTS: The response rate was 75% (n = 92). Mean agreement with CD benefit was 4.2 (SD = 0.82) and CDIM membership 3.8 (SD = 0.95). Eighty-one percent and 58% of CDs agreed with the respective statements. Significant predictors of CD benefit were CD and coordinator salary support, years as CD, and receiving a university teaching award. Structured discussions of expectations strongly predicted perceiving CDIM benefit. CONCLUSIONS: Most CDs agreed that their CD role and CDIM benefited their careers. Salary support and clearly defining expectations may increase the likelihood of perceiving benefit.
Assuntos
Mobilidade Ocupacional , Estágio Clínico/estatística & dados numéricos , Medicina Interna/organização & administração , Diretores Médicos/estatística & dados numéricos , Adulto , Autoria , Distinções e Prêmios , Canadá , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Papel do Médico , Apoio à Pesquisa como Assunto/estatística & dados numéricos , Estados UnidosRESUMO
Central nervous system (CNS) involvement is a rare occurrence in the course of human immunodeficiency virus (HIV)-related Hodgkin's disease (HD). We report the clinical course of a patient with HIV infection who developed systemic HD, mixed cellularity subtype, later complicated by leptomeningeal involvement. The patient died from his illness, and autopsy was performed. Examining the brain lesion, Epstein-Barr virus (EBV) presence was demonstrated in Reed-Sternberg cells by immunohistochemistry using an EBER probe for EBV RNA. This is the second case report in the English literature of HD involving the CNS in an HIV-positive individual, and the first demonstrating EBV presence. Extranodal presence of Hodgkin's disease in patients with HIV infection is probably related to immunosuppression, and physicians treating this illness should be alert to the potential of unusual sites of involvement.