Quality assessment of randomized controlled trials of contrast media

Numerous randomized controlled trials (RCTs) have been conducted to define the relative benefits of low-osmolality contrast media (LOM) and high-osmolality contrast media (HOM). Because of the clinical and economic significance of the conclusions drawn from these RCTs, the authors used a standardized instrument to evaluate the quality of study design and data analysis of 100 RCTs published between 1982 and 1987 that compared LOM and HOM. The mean quality score (+/- standard deviation) was 39 +/- 12 (maximum possible score, 100). The largest number of patients studied in any RCT was 435; the smallest was five. A majority of the RCTs received high scores on three attributes of quality, intermediate scores on seven, and low scores on nine. These results underscore the difficulty of designing, performing, analyzing, and reporting high-quality RCTs. Nevertheless, limitations in study design and data analysis need to be considered when interpreting results of these RCTs. Future RCTs comparing LOM and HOM should be performed with greater attention to basic elements of good study design and data analysis.     

HIV controllers exhibit potent CD8 T cell capacity to suppress HIV infection ex vivo and peculiar cytotoxic T lymphocyte activation phenotype

Some rare HIV-1-infected individuals, referred to as HIV controllers (HIC), have persistently undetectable plasma viral load in the absence of therapy. This control of HIV-1 replication has been associated with a strong, multifunctional specific CD8(+) T cell response. However, no direct link between this immune response and the control of viremia has so far been provided. We investigated parameters of specific CD8(+) T cell response and in vitro susceptibility to HIV-1 infection in 11 HIC. We found high frequencies of HIV-specific CD8(+) T cells. Interestingly, these cells expressed the activation marker HLA-DR but not CD38. This unique phenotype differentiates HIV-specific CD8(+) T cells from HIC and noncontroller subjects and likely reflects a high potential to expand upon exposure to antigen and a capacity to exert effector functions. Accordingly, although CD4(+) T cells from HIC were fully susceptible to HIV-1 superinfection, their CD8(+) T cells effectively suppressed HIV-1 infection. Remarkably, this potent anti-HIV activity was observed without prior stimulation of CD8(+) T cells. This activity was not mediated by secreted inhibitory factors but was due to the elimination of infected CD4(+) T cells and was observed only with autologous CD4(+) T cells, indicating an HLA-restricted cytotoxic mechanism. This constitutive antiviral capacity of CD8(+) T cells could account for the control of viral replication in HIC.     

Intraductal papillary-mucinous tumors of the pancreas: Clinicopathologic features, outcome, and nomenclature. Members of the Pancreas Clinic, and Pancreatic Surgeons of Mayo Clinic

BACKGROUND & AIMS: Intraductal papillary-mucinous tumor (IPMT) of the pancreatic ducts is increasingly recognized. This study investigated if clinical, imaging, or, histological features predicated outcome, formulated a treatment algorithm, and clarified relationships among IPMT, mucinous cystic neoplasms of the pancreas (MCN), and chronic pancreatitis. METHODS: The medical records, radiographs, and pathological specimens of 15 patients with IPMT (dilated main pancreatic duct or branch ducts with mucin overproduction) who were evaluated between October 1983 and January 1994 were reviewed. RESULTS: One patient had hepatic metastases. Fourteen underwent an operation (6 distal pancreatectomy, 4 total pancreatectomy, and 4 pancreaticoduodenectomy); all had dysplastic intraductal epithelium and chronic pancreatitis, whereas 3 had invasive adenocarcinoma. After a median of 25 months, 10 patients were alive; 3 of 4 with malignant and 2 of 11 with benign IPMT died (P < 0.05). Patients with or without carcinoma had similar clinical and radiographic features. A clinical diagnosis of chronic pancreatitis had been made in 9 patients with benign IMPT and in none with malignant IPMT (P < 0.05). CONCLUSIONS: IPMT is a dysplastic and likely precancerous lesion that is frequently diagnosed as chronic pancreatitis and is separate from MCN. Because it is not possible to distinguish noninvasive from invasive IPMT preoperatively, complete surgical excision of the dysplastic process is our treatment of choice whenever appropriate. (Gastroenterology 1996 Jun;110(6):1909-18)     

Reversal of acute ("malignant") myelosclerosis by allogeneic bone marrow transplantation

A 28-yr-old woman with acute malignant myelosclerosis received, as primary treatment, ablative chemotherapy and total body radiation therapy followed by bone marrow transplantation from her histocompatible brother. The patient is now well more than 15 mo after bone marrow transplantation, with normal peripheral blood counts, a normal bone marrow, no evidence of graft-versus-host disease, and is on no therapy. In light of the poor results obtained with conventional chemotherapy in this disease, bone marrow transplantation may represent the treatment of choice for patients who have an appropriate donor.     

Multicenter trial of the proficiency of smart quantitative sensation tests

Introduction: We assessed proficiency (accuracy and intra‐ and intertest reproducibility) of smart quantitative sensation tests (smart QSTs) in subjects without and with diabetic sensorimotor polyneuropathy (DSPN). Methods: Technologists from 3 medical centers using different but identical QSTs independently assessed 6 modalities of sensation of the foot (or leg) twice in patients without (n = 6) and with (n = 6) DSPN using smart computer assisted QSTs. Results: Low rates of test abnormalities were observed in health and high rates in DSPN. Very high intraclass correlations were obtained between continuous measures of QSTs and neuropathy signs, symptoms, or nerve conductions (NCs). No significant intra‐ or intertest differences were observed. Conclusions: These results provide proof of concept that smart QSTs provide accurate assessment of sensation loss without intra‐ or intertest differences useful for multicenter trials. Smart technology makes possible efficient testing of body surface area sensation loss in symmetric length‐dependent sensorimotor polyneuropathies. Muscle Nerve 49 : 645–653, 2014     

Culture of autologous bone marrow in diffusion chambers: effect of host irradiation

Autologous bone marrow (BM) cells were cultured in diffusion chambers (DC) implanted into whole-body irradiated, non-irradiated, or sham- irradiated goats. Proliferation was apparent in DC implanted in both irradiated and nonirradiated goats. However, cells in DC cultured in irradiated hosts increased in number beginning earlier, proceeded at a faster rate, and reached higher numbers than in DC in nonirradiated hosts. Growth enhancement could not have occurred as a result of radiation-induced immunosuppression in autologous hosts. The nonirradiated "target cells" in the DC therefore constituted an indicator system for stimulatory or inhibitory substances in the host. The simultaneous increase in the number of granulocytes in peripheral blood and in DC of irradiated hosts was paralleled by an initial rise in serum colony-stimulating factor (CSF). A second, prolonged period of severe granulocytopenia following irradiation of the host correlated with high levels of serum CSF. Increased numbers of megakaryocytes were seen in DC as thrombocytopenia developed in the irradiated host. DC erythropoiesis disappeared rapidly in nonirradiated goats; however, in DC of irradiated goats, the number of erythrocytic precursors increased exponentially during ablation of host erythroid marrow. Anemia did not develop in the host during the culture period. Proliferation of mononuclear cells in DC was markedly stimulated by irradiation of the host. Proliferation of macrophages appeared independent of host treatment. These observations provide strong evidence for diffusion of specific and/or nonspecific humoral hematopoietic stimulators from the host into the DC. This stimulation appears to be elicited and/or intensified by irradiation of the host.     

Integrin alpha 4 beta 1 and glycoprotein IV (CD36) are expressed on circulating reticulocytes in sickle cell anemia

The abnormal adherence of red blood cells, especially circulating reticulocytes (erythrocyte precursors), to the endothelium is believed to contribute to vascular occlusion observed in patients with sickle cell disease. Although several plasma proteins including von Willebrand factor and fibronectin have been proposed to mediate this adhesion, the mechanism of sickle cell adhesion to the endothelium remains unknown. Using flow cytometry, we screened sickle red blood cells with monoclonal antibodies (MoAbs) against known adhesion receptors and detected integrin subunits alpha 4 and beta 1 and the nonintegrin glycoprotein IV on reticulocytes but not on erythrocytes. No reactivity was detected against integrin subunits alpha 2, alpha 3, alpha 5, alpha 6, alpha v, beta 2, beta 3, integrin alpha IIb beta 3, or the nonintegrin glycoprotein Ib. Immunoprecipitation of reticulocytes with either alpha 4- or beta 1-specific antibodies identified the alpha 4 beta 1 complex (alpha 4(70) and alpha 4(80) forms), a receptor for fibronectin and vascular cell adhesion molecule-1. An antibody against glycoprotein IV, a receptor reported to bind thrombospondin and collagen, immunoprecipitated an 88-kD protein consistent with its reported M(r). MoAbs against alpha 4 and glycoprotein IV bound to an average of 4,600 and 17,500 sites per reticulocyte, respectively. Identification of alpha 4 beta 1 and glycoprotein IV on reticulocytes suggests both plasma-dependent and independent mechanisms of reticulocyte adhesion to endothelium and exposed extracellular matrix.     

外伤性主动脉破裂致全程胸主动脉夹层1例

抢救1例因摩托车事故急诊入院男病人。X线胸片发现病人右气管旁外侧纹理和左纵隔影异常增宽，并扩展至主动脉弓水平。经食管心脏超声检查发现围绕主动脉根部和升主动脉的壁间水肿。延伸至主动脉弓和左横膈下水平的全程降主动脉；左锁骨下动脉起始点远端降主动脉上端全层断裂。急诊手术行降主动脉上端端端吻合，终因心跳骤停未及手术死亡。尸检证实全程胸主动脉自破裂处向前和逆向延伸，引起双向主动脉夹层。