Clinical MR imaging with a Helmholtz-type surface coil

Limited-field-of-view radio-frequency receiver antennas provide improved near-field sensitivity for magnetic resonance imaging by decreasing the antenna volume. The Helmholtz-type surface coil, consisting of two flat rings, is an organ-encompassing antenna that takes advantage of this principle to yield an improved signal-to-noise ratio (S/N). The coil was tested in a group of 50 patients and 16 healthy volunteers. Images obtained with the Helmholtz coil demonstrated quantitatively superior S/N of 2.2-fold or greater than that of comparison body coil images, as well as qualitatively superior anatomic resolution.     

Longitudinal neurological follow-up of a group of HIV-seropositive and HIV-seronegative hemophiliacs: results from the hemophilia growth and development study

BACKGROUND: Boys and young men with hemophilia treated with factor infusions before 1985 had a substantial risk of acquiring the human immunodeficiency virus (HIV) and the acquired immunodeficiency syndrome. This study was designed to assess the effects of HIV and hemophilia per se on neurological function in a large cohort of subjects with hemophilia, and to investigate the relationships between neurological disease and death during follow-up. METHODS: Three hundred thirty-three boys and young men (207 HIV seropositive and 126 HIV seronegative) were evaluated longitudinally in a multicenter, multidisciplinary study. Neurological history and examination were conducted at baseline and annually for 4 years. The relationship between neurological variables, HIV serostatus, CD4+ cell counts, and vital status at the conclusion of the study was examined using logistic regression models. RESULTS: The risks of nonhemophilia-associated muscle atrophy, behavior change, and gait disturbance increased with time in immune compromised HIV-seropositive subjects compared with HIV seronegative or immunologically stable HIV-seropositive subjects. The risk of behavior change in immune compromised HIV-seropositive hemophiliacs, for example, rose to 60% by year 4 versus 10% to 17% for the other study groups. Forty-five subjects (13.5%), all of whom were HIV seropositive, died by year 4. Subjects who died had had increased risks of hyperreflexia, nonhemophilia-associated muscle atrophy, and behavior change. CONCLUSIONS: These results indicate that immune compromised, HIV-seropositive hemophiliacs have high rates of neurological abnormalities over time and that neurological abnormalities were common among subjects who later died. By contrast, immunologically stable HIV-seropositive subjects did not differ from the HIV-seronegative participants. Hemophilia per se was associated with progressive abnormalities of gait, coordination, and motor function.     

Solitary skeletal hemangioma of the extremities

Objective. To report the clinicopathologic features of solitary skeletal hemangioma of the extremities and to review previous cases in the English language medical literature. Patients. In addition to five of our own cases, 34 literature cases with substantial and 75 with partial clinicopathologic information were found. Results. Our patients, three men and two women, ranged in age from 37 to 83 years (mean 65.6 years). The lesion was an incidental radiologic finding in two patients, while three were symptomatic. In no case was a correct preoperative radiologic diagnosis made, a malignant process being considered as a possibility in all. The hemangiomas were medullary; two involved a metacarpal, two the fibula, and one the humerus. In contrast, previously reported patients were younger (mean age 32 years), predominantly female (60%), and symptomatic in over 90% of cases. The lesion is rare in those younger than age 10 years or older than age 60 years. As in our patients, the long bones are most frequently involved (75%), with the diaphysis or metadiaphysis, as in four of our patients, the most common locations. Although 20% of cases occur in the hands or feet, metacarpal involvement is rare. Medullary origin, as in all of our cases, is most frequent, but 45% of cases are either periosteal (33%) or intracortical (12%). In the literature, cavernous hemangioma is the most frequent type. Three of our hemangiomas were cavernous, one capillary, and one venous, the latter being rarely reported in extremity bones. Conclusions. Due to the diversity of radiologic patterns produced by skeletal hemangioma, a correct preoperative diagnosis is rarely made. Almost all patients do well, even those with less than complete removal of the lesion; local recurrence is rare. All of our patients were well following either therapeutic or simple diagnostic procedures. Due to the destructive nature of some biopsy procedures, the histologic diagnosis of hemangioma may at times also be problematic. Received: 7 February 2000 Revision requested: 31 March 2000 Revision received: 25 May 2000 Accepted: 26 May 2000     

Is multiple SNP testing in BRCA2 and BRCA1 female carriers ready for use in clinical practice? Results from a large Genetic Centre in the UK

BRCA1 and BRCA2 are major breast cancer susceptibility genes. Nineteen single nucleotide polymorphisms (SNPs) at 18 loci have been associated with breast cancer. We aimed to determine whether these predict breast cancer incidence in women with BRCA1/BRCA2 mutations. BRCA1/2 mutation carriers identified through the Manchester genetics centre between 1996 and 2011 were included. Using published odds ratios (OR) and risk allele frequencies, we calculated an overall breast cancer risk SNP score (OBRS) for each woman. The relationship between OBRS and age at breast cancer onset was investigated using the Cox proportional hazards model, and predictive ability assessed using Harrell's C concordance statistic. In BRCA1 mutation carriers we found no association between OBRS and age at breast cancer onset: OR for the lowest risk quintile compared to the highest was 1.20 (95% CI 0.82–1.75, Harrell's C = 0.54), but in BRCA2 mutation carriers the association was significant (OR for the lowest risk quintile relative to the highest was 0.47 (95% CI 0.33–0.69, Harrell's C = 0.59). The 18 validated breast cancer SNPs differentiate breast cancer risks between women with BRCA2 mutations, but not BRCA1. It may now be appropriate to use these SNPs to help women with BRCA2 mutations make maximally informed decisions about management options.     

肝炎病毒利用DC-SIGN逃逸机体免疫作用

DC-SIGN是DC表面识别多种病原微生物的受体.一方面,DC借助DC-SIGN对固有免疫及适应性免疫发挥免疫调节作用;另一方面,DC-SIGN又成为某些病原微生物如肝炎病毒借以逃逸机体免疫防御功能的靶分子.我们就DC-SIGN的结构及功能、与病毒的相互作用等方面进行阐述.     

Induction of proliferation of B prolymphocytic leukemia cells by phorbol ester and native or recombinant interferon-gamma

Phorbol ester phorbol myristate acetate (PMA) induces proliferation in nonmalignant human B cells and B cells from a patient with B prolymphocytic leukemia (B-PLL). Mitogen-free T cell-derived conditioned medium acts synergistically with PMA in inducing proliferation of B-PLL cells but does not enhance the PMA-stimulated outgrowth of nonmalignant B cells. Interleukin 2 (IL-2) has no effect on the outgrowth of B-PLL cells, and monoclonal antibodies against the IL-2 receptor do not influence the response to PMA and conditioned medium. Recombinant interferon-gamma (IFN-gamma), in contrast, is a potent enhancer of PMA-induced proliferation of B-PLL cells. With gel filtration techniques and with the use of anti-IFN-gamma antibodies, it is shown that IFN-gamma in the conditioned medium is responsible for the observed increase in B-PLL cell proliferation. Preincubation of B- PLL cells with IFN-gamma induces responsiveness to PMA, whereas IFN- gamma alone had no effect on these cells when pretreated with PMA. The combined data show that, in the presence of PMA, native and recombinant IFN-gamma are growth factors for B cells from a B-PLL patient and that IL-2 is not involved in this process.     

Occurrence of the t(2;5)(p23;q35) in non-Hodgkin's lymphoma

Primary CD30(Ki-1)-positive anaplastic large-cell lymphoma (ALCL) is considered by some to be a distinct clinicopathologic entity associated with the t(2;5) (p23;q35). However, the specificity of t(2;5) for ALCL has not been carefully studied. Therefore, we performed a detailed analysis of all cases of ALCL with abnormal cytogenetics results in the Nebraska Lymphoma Study Group registry, as well as all other cases of non-Hodgkin's lymphoma with t(2;5) in the registry. We found the t(2;5) in only five of 10 cases of ALCL, four of whom were young patients. However, we also found the t(2;5) in 11 other cases of nonanaplastic lymphoma, including eight children with typical peripheral T-cell lymphomas of various types. The t(2;5) was also found in three older adults with B-cell lymphomas of various types. Thus, the t(2;5) was not specific for CD30+ ALCL. However, t(2;5) may define a clinicopathologic entity in children and young adults characterized by variable morphologies with a T-cell or indeterminate phenotype, CD30-positivity, nodal disease with frequent extranodal involvement, advanced stage, and an excellent response to therapy, including bone marrow transplantation for relapsed disease. The clinical relevance of the t(2;5) in older patients requires further study.