Nearly complete regression of tumors via collective behavior of magnetic nanoparticles in hyperthermia.

One potential cancer treatment selectively deposits heat to the tumor through activation of magnetic nanoparticles inside the tumor. This can damage or kill the cancer cells without harming the surrounding healthy tissue. The properties assumed to be most important for this heat generation (saturation magnetization, amplitude and frequency of external magnetic field) originate from theoretical models that assume non-interacting nanoparticles. Although these factors certainly contribute, the fundamental assumption of 'no interaction' is flawed and consequently fails to anticipate their interactions with biological systems and the resulting heat deposition. Experimental evidence demonstrates that for interacting magnetite nanoparticles, determined by their spacing and anisotropy, the resulting collective behavior in the kilohertz frequency regime generates significant heat, leading to nearly complete regression of aggressive mammary tumors in mice.

Heart muscle disease related to HIV infection: prognostic implications.

OBJECTIVES: To determine the natural course of heart muscle disease in patients infected with HIV. DESIGN: Prospective echocardiographic survey and observational study over four years. SETTING: Edinburgh. SUBJECTS: 296 adults infected with HIV (mean age 32.7 years (range 21.5 to 67.6) drawn from all the major groups at risk of HIV infection in Britain. MAIN OUTCOME MEASURES: Detection of myocardial dysfunction and time to death from index echocardiogram in serial echocardiography. RESULTS: Cardiac dysfunction was identified in 44 subjects (dilated cardiomyopathy, 13; isolated right ventricular dysfunction, 12; borderline left ventricular dysfunction, 19). Dilated cardiomyopathy was strongly associated with a CD4 cell count of < 100 x 10(6)/l, in contrast with the other forms of cardiac dysfunction. During the study 12/13 (92%) subjects with dilated cardiomyopathy, 5/12 (42%) with right ventricular dysfunction, and 8/19 (42%) with borderline left ventricular function died of conditions related to AIDS. Survival was significantly reduced in the subjects with dilated cardiomyopathy compared with those with normal hearts (P < 0.001). The median survival from the index echocardiogram was 101 days (95% confidence interval 42 to 146) for the subjects with cardiomyopathy compared with 472 days (383 to 560) for those with normal hearts and a CD4 cell count of < 20 x 10(6)/l. No significant difference existed in survival for subjects with borderline left or isolated right ventricular dysfunction. CONCLUSION: Even after adjustment for the significantly reduced CD4 cell count with which dilated cardiomyopathy is associated, the outlook for patients with HIV infection and dilated cardiomyopathy is poor. Isolated right and borderline left ventricular dysfunction are not associated with reduced CD4 cells counts and do not carry adverse prognostic implications.

A report of human parvovirus B19 infection in hydrops fetalis. First Australian cases confirmed by serology and immunohistology.

OBJECTIVE: To present the first Australian cases of fetal hydrops induced by parvovirus B19. CLINICAL FEATURES: Autopsies on two cases of intrauterine fetal death with hydrops fetalis and pallor revealed evidence of myocarditis and widespread characteristic inclusion-bearing cells, predominantly erythroblasts. The diagnosis of hydrops fetalis induced by parvovirus B19 was confirmed in both cases by immunohistological localisation of the viral inclusions by means of a monoclonal antibody to the VP1 and VP2 proteins of parvovirus B19. A low level of parvovirus B19 IgM antibodies was detected in the second case. CONCLUSIONS: It is possible that our relatively small population and lack of familiarity with the histopathological features may have led to underdiagnosis rather than a true absence of fetal parvovirus B19 infection in Australia. The condition can be diagnosed and treated antenatally and therefore should be included in the differential diagnosis of causes of hydrops fetalis.