Site selection for fat autotransplantation: Some observations

The use of autologous fat for implantation has recently received renewed attention in the plastic surgery literature. Autologous fat reportedly has been used for the treatment of wrinkles and Romberg's disease, and for buttock and breast augmentation. While some measure of success has been achieved, many surgeons report that substantial resorption of fat tissue occurs at the site of implantation. There is lack of unanimity regarding the ideal site for extraction or injection in order to minimize fat resorption. Adipose tissue samples were taken from women undergoing surgical procedures on the abdomen, gluteal-femoral region, and breast. Facial adipose tissue samples from men and women were also analyzed. Adipocytes were isolated chemically and sized microscopically. Activity of the lipogenic enzyme adipose tissue lipoprotein lipase (ATLPL) was measured in frozen samples. Results suggest that femoral site samples are somewhat larger (NS) and have greater lipogenic activity (p<0.03) than other sites. In our study, small facial samples had very low or unmeasurable levels of ATLPL activity. Perhaps cell size and lipogenic activity should be considered when selecting tissues for autotransplantation.     

Gadoteridol dose dependence in MR imaging of a liver abscess model

A necrotic liver abscess model was studied with magnetic resonance (MR) imaging at 1.5 T before and after intravenous administration of gadoteridol at doses of 0.1, 0.25, and 0.5 mmol/kg in 24 rabbits. Enhancement characteristics and lesion delineation were assessed with both breath-hold and non-breath-hold imaging techniques. Lesion delineation, as assessed both by signal intensity measurements and evaluations by two image readers blinded to imaging technique, was greatest on high-dose (0.5 mmol/kg) breath-hold images. Lesion rim enhancement was seen consistently only on postcontrast images obtained at a dose of 0.5 mmol/kg and progressed with time after injection of contrast material.     

A study comparing biopharmaceutic characteristics of four once daily controlled release diltiazem preparations

Summary— In the present study we have compared the steady state biopharmaceutic characteristics of four diltiazem once daily controlled release capsules: Mono-Tildiem LP 300® (300 mg), Adizem® XL (300 mg)¹, Cardizem® (300 mg) and Dilacor® (240 mg). Sixteen healthy male volunteers (aged 22.9 ± 3.3 years, range 19–31 years) completed an open label, multiple oral dose, randomized, four-period crossover study without a washout period in between. The volunteers received each diltiazem formulation once daily for four days. Trough diltiazem and metabolites plasma concentrations were determined on days 3 and 4. The 24-h plasma concentration-time profiles were assessed after the dose on day 4 of each period. The following steady state pharmacokinetic parameters for diltiazem were calculated: the minimum plasma concentration (c_min), the maximum plasma concentration (c_max), the time to reach that concentration (t_max), the time interval during which the plasma concentration exceeds 50% of c_max (t₅₀), the area under the plasma concentration-time curve (AUC_72–96) and the peak-to-trough fluctuation (PTF). For the metabolites of diltiazem, N-mono-desmethyl-diltiazem (NDM) and desacetyldiltiazem (DAD), AUC_72–96 (AUC_NDM and AUC_DAD) and the ratio metabolite/parent compound were calculated. Steady state was achieved on day 3. Except one, all controlled release formulations have satisfactory controlled release properties allowing once daily administration. However, significant (P < 0.05) differences were found between the pharmacokinetic characteristics which do not allow exchange of the various formulations. Concentrations well below 50 ng·mL^-1 in the morning hours were observed for Dilacor® (240 mg) and Adizem® XL (300 mg), which could be a disadvantage of these formulations as it is well-known that ischaemic events occur at a higher rate during that part of the day. The plasma concentration profiles of NDM and DAD, the major circulating metabolites, parallel the plasma concentration profiles for the parent compound. From a clinical point of view, all treatments were well tolerated.     

Techniques for high-resolution MR imaging of atherosclerotic plaque

Atherosclerotic cardiovascular disease is the most common cause of death in the United States. Investigation of atherosclerotic plaque morphology and composition is important because the findings may be useful in predicting prognosis or response to therapy. This study presents high-resolution magnetic resonance (MR) imaging techniques developed on a 1.5-T whole-body imager with a custom-built surface coil, for characterizing the composition and morphology of plaque removed at carotid endarterectomy. The initial comparison of MR imaging and histologic results showed good correlation. In conjunction with MR angiography, these techniques could be used in in vivo imaging to define the size, location, and contents of atherosclerotic plaque at the carotid bifurcation.     

Segmental intestinal muscular thinning: a possible cause of intestinal obstruction in the newborn

Intestinal obstruction proximal to a transition zone without an interposed physical barrier usually indicates Hirschsprung disease. The authors report one case of focal small bowel muscular thinning just distal to a transition zone that produced clinical and radiographic findings that simulated long-segment Hirschsprung disease in a 2-day-old infant.     

alpha4 integrins and L-selectin differently orchestrate T-cell activity during diabetes prevention following oral administration of CTB-insulin

Oral administration of insulin conjugated to the B chain of cholera toxin (CTB-insulin) in non-obese diabetic (NOD) mice results in diabetes prevention. We investigated the respective contributions of L-selectin (CD62L) and alpha4-integrin pathways during CTB-driven tolerance. Purified CD62L+CD4+ cells from CTB-insulin fed mice significantly reduced the capacity of diabetogenic T cells to transfer diabetes in syngeneic recipients. In vivo antibody blockade of fed animals during adoptive co-transfer experiments indicated that both CD62L and alpha4-integrins pathways were necessary to develop a protective response after oral tolerance induction. In contrast, when antibodies were given to recipient mice, only CD62L was critical for the protection. In vitro stimulated CD62L+CD4+ cells from the spleen of fed animals secreted lower amounts of IL-4 and IL-10 but comparable levels of TGFbeta than CD62L-cells. A reduced IFN-gamma production between the two cell subsets was specifically observed in CTB-insulin fed mice. Furthermore, antibody treatments induced changes in T-cell migration to the spleen, mesenteric and pancreatic lymph nodes. The protective effect was also associated with migration of regulatory T cells into pancreatic islets. Taken together, our results suggest that L-selectin and alpha4-integrin have distinct but complementary roles in the generation and function of regulatory CD4+ T cells following CTB-insulin administration.