A new local multiscale Fourier analysis for medical imaging

The Stockwell transform (ST), recently developed for geophysics, combines features of the Fourier, Gabor and wavelet transforms; it reveals frequency variation over time or space. This valuable information is obtained by Fourier analysis of a small segment of a signal at a time. Localization of the Fourier spectrum is achieved by filtering the signal with frequency-dependent Gaussian scaling windows. This multi-scale time-frequency analysis provides information about which frequencies occur and more importantly when they occur. Furthermore, the Stockwell domain can be directly inferred from the Fourier domain and vice versa. These features make the ST a potentially effective tool to visualize, analyze, and process medical imaging data. The ST has proven useful in noise reduction and tissue texture analysis. Herein, we focus on the theory and effectiveness of the ST for medical imaging. Its effectiveness and comparison with other linear time-frequency transforms, such as the Gabor and wavelet transforms, are discussed and demonstrated using functional magnetic resonance imaging data.     

Inhibition of experimental autoimmune encephalomyelitis in Lewis rats by nasal administration of encephalitogenic MBP peptides: synergistic effects of MBP 68-86 and 87-99

Induction of mucosal tolerance by inhalation of soluble peptides with defined T cell epitopes is receiving much attention as a means of specifically down-regulating pathogenic T cell reactivities in autoimmune and allergic disorders. Experimental autoimmune encephalomyelitis (EAE) induced in the Lewis rat by immunization with myelin basic protein (MBP) and Freund's adjuvant (CFA) is mediated by CD4+ T cells specific for the MBP amino acid sequences 68-86 and 87-99. To further define the principles of nasal tolerance induction, we generated three different MBP peptides (MBP 68-86, 87-99 and the non- encephalitogenic peptide 110-128), and evaluated whether their nasal administration on day -11, -10, -9, -8 and -7 prior to immunization with guinea pig MBP (gp-MBP) + CFA confers protection to Lewis rat EAE. Protection was achieved with the encephalitogenic peptides MBP 68-86 and 87-99, MBP 68-86 being more potent, but not with MBP 110-128. Neither MBP 68-86 nor 87-99 at doses used conferred complete protection to gp-MBP-induced EAE. In contrast, nasal administration of a mixture of MBP 68-86 and 87-99 completely blocked gp-MBP-induced EAE even at lower dosage compared to that being used for individual peptides. Rats tolerized with MBP 68-86 + 87-99 nasally showed decreased T cell responses to MBP reflected by lymphocyte proliferation and IFN-gamma ELISPOT assays. Rats tolerized with MBP 68-86 + 87-99 also had abrogated MBP-reactive IFN-gamma and tumor necrosis factor-alpha mRNA expression in lymph node cells compared to rats receiving MBP 110-128 nasally, while similar low levels of MBP-reactive transforming growth factor-beta and IL-4 mRNA expressing cells were observed in the two groups. Nasal administration of MBP 68-86 + 87-99 only slightly inhibited guinea pig spinal cord homogenate-induced EAE, and passive transfer of spleen mononuclear cells from MBP 68-86 + 87-99-tolerized rats did not protect naive rats from EAE. Finally, we show that nasal administration of MBP 68-86 + 87-99 can reverse ongoing EAE induced with gp-MBP, although higher doses are required compared to the dosage needed for prevention. In conclusion, nasal administration of encephalitogenic MBP peptides can induce antigen-specific T cell tolerance and confer incomplete protection to gp-MBP-induced EAE, and MBP 68-86 and 87-99 have synergistic effects. Non-regulatory mechanisms are proposed to be responsible for tolerance development after nasal peptide administration.      

Randomized placebo-controlled study of low-dose warfarin for the prevention of central venous catheter-associated thrombosis in patients with cancer.

PURPOSE: In this multicenter, randomized, placebo-controlled clinical trial, we studied whether warfarin 1 mg daily reduces the incidence of symptomatic central venous catheter (CVC) -associated thrombosis in patients with cancer. PATIENTS AND METHODS: Two hundred fifty-five patients with cancer who required a CVC for at least 7 days were randomly assigned to receive warfarin 1 mg or placebo. RESULTS: There were 11 (4.3%) symptomatic CVC-associated thromboses among 255 patients, with no difference in the incidence of symptomatic CVC-associated thrombosis between patients taking warfarin 1 mg daily (six of 130 patients; 4.6%) and patients taking placebo (five of 125 patients; 4.0%; hazard ratio, 1.20; 95% CI, 0.37 to 3.94). Warfarin had no effect on CVC life span (84 days v 63 days in control and warfarin groups, respectively; 95% confidence limit, -16 to 55 days; P = .09), and it did not affect the number of premature CVC removals (23.2% v 25.4% in control and warfarin groups, respectively; 95% confidence limit of difference -8.34 to 12.71; P = .68) or the frequency of major bleeding episodes (2% v 0% in control and warfarin groups, respectively; P = .5, Fisher's exact test). CONCLUSION: Symptomatic CVC-associated thrombosis in patients with cancer, although significant, is less common than previously reported. In this study, the administration of warfarin 1 mg daily did not reduce the incidence of symptomatic CVC-associated thrombosis in patients with cancer. However, the low rate of symptomatic CVC-associated thrombosis means that a much larger trial is required to address this issue definitively.     

Challenges of connectedness in personal recovery for rural mothers with mental illness

Social connection is a fundamental human need, but challenging for individuals with characteristics that are socially stigmatized. Parenting with mental illness presents obstacles, as well as opportunities, for connection. In the present study, we examined connectedness within a personal recovery paradigm for rural mothers with a mental illness. In‐depth interviews with 17 mothers with a mental illness, utilizing constructivist grounded theory, resulted in six categories of meaning, including ‘yearning for connection’, ‘connecting intensely’, ‘encountering rejection and exclusion’, ‘choosing isolation’, ‘being known’, and ‘finding peers/helping others’. Women expressed a strong desire for connection, but for many, prior experiences of trauma and rejection created barriers to the development of trust, preventing some women from seeking opportunities for connection. Connectedness to self and significant others, and a broader life meaning and purpose can support and expedite personal recovery from mental illness for rural women. However the factors that contribute to the mental illness might also inhibit the development of trust needed to attain social connection. Increasing connectedness in mothers with mental illness is a complex endeavour requiring concerted focus as distinct from other service‐delivery goals. The perinatal period could be a key time for intervention.     

Prevalence of mental illness within families in a regional child‐focussed mental health service

Nearly 50% of all mental illnesses begin in childhood before the age of 14 years, and over 20% of parents have a mental illness. Few studies have examined the co‐occurrence of mental illnesses in parents and children. In the present study, we examined the extent of mental illness within families of 152 clients attending an Australian regional child and adolescent mental health service (CAMHS). A cross‐sectional study design was employed involving a case record review and clinician‐completed questionnaire of the children and youth attending a CAMHS. It was found that 79% of these children were living with a parent with mental illness. The predominant diagnosis of both child and parent was an anxiety or mood disorder, and many families had co‐occurring risk factors of domestic violence and limited social supports. The findings in this Australian cohort are similar to those of other international research. While novel in nature, the present study has highlighted the extent of both mental illness and scarce supports for both children and parents in the same family. The findings indicate the need for a coordinated multiservice delivery of appropriate and consistent family‐focussed interventions, responding to both mental illness and social supports for children and parents. Further research should examine specific components of family need and support, as seen through the eyes of the child and their parent.     

Diet and exercise in type 2 diabetes mellitus.

The question is no longer whether diet and exercise can benefit the individual with type 2 diabetes. Rather, the type and duration of exercise the magnitude of the effects on glycemic control, insulin sensitivity, and on risk factors for cardiovascular disease must be considered in determining the feasibility and acceptability of an intervention program. It is now clear that regular physical exercise is important in both the prevention and treatment of type 2 diabetes. The benefits of exercise are many and include increased energy expenditure, which, combined with dietary restriction, leads to decreased body fat, increased insulin sensitivity, improved long-term glycemic control, improved lipid profiles, lower blood pressure, and increased cardiovascular fitness. Persons with type 2 diabetes often find it difficult to exercise and are at increased risk for injury or exacerbation of underlying diseases or diabetic complications. Therefore, before starting an exercise program, all patients with type 2 diabetes should have a complete history and physical examination, with particular attention to evaluation of cardiovascular disease, medications that may affect glycemic control during or after exercise, and diabetic complications including retinopathy, nephropathy, and neuropathy. Exercise programs should be designed to start slowly, build up gradually, and emphasize moderately intense exercise performed at least three times a week and preferably five to seven times a week for best results.