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.     

Investigation of the Photosensitive Child

Photosensitivity disorders in childhood frequently can be diagnosed and managed in the general dermatology clinic. Occasionally, when diagnostic doubt exists, referral to a specialist unit is required for diagnostic phototesting. Light testing equipment is fickle by nature, making such units uncommon. Phototesting using monochromator or provocation systems takes approximately 45 minutes. Immediate and delayed readings over the following 48 hours as appropriate are required to cover the diagnostic possibilities. Individual diseases are characterized by particular patterns of wavelength dependency and evolution of the abnormal response. Other investigations that may be required are autoantibodies to exclude lupus erythematosus, a porphyrin scan leading to full studies and, on occasion, cell mutation or survival, and chromosome studies for the rarer genophotodermatoses. Good investigative data frequently help clarify the common clinical variants.     

Inhibitory actions of GABA on rabbit urinary bladder muscle strips: mediation by potassium channels.

1. The actions of gamma-aminobutyric acid (GABA) upon rabbit urinary bladder muscle were investigated to determine whether they were mediated through potassium channels. 2. In vitro experiments were undertaken in which bladder muscle strips were caused to contract with carbachol. Addition of GABA or baclofen reduced the size of such evoked contractions in the case of GABA by 20.7 +/- 3.2%, in the case of baclofen by 22.4 +/- 2.2%. 3. Electrical stimulation of autonomic nerves in bladder wall strips also evoked contractions which were significantly smaller in potassium-free Krebs solution. The size of contractions produced by carbachol on the other hand were unaffected by the absence of potassium in the Krebs solution. 4. The inhibitory actions of GABA and baclofen on carbachol-induced contractions of bladder muscle were detected at much lower concentrations in potassium-free compared with potassium containing solutions. 5. The inhibitory effects of baclofen were completely reversed by tetraethyl ammonium chloride between 1 and 5 mM, caesium chloride between 0.5 and 3 mM and barium chloride between 0.5 and 2.5 mM. The actions of baclofen were only partially reversed by 4-amino-pyridine between 1 and 5 mM. 6. It was concluded that the GABAB receptor-mediated inhibitory actions on rabbit urinary bladder smooth muscle cells were produced by activation of potassium channels.     

Total hip reconstruction in a woman with Cornelia de Lange syndrome: a case report.

More than 250 cases of Cornelia de Lange syndrome have been reported in the medical literature, but not have described the use of hip reconstruction to correct the congenital dysplasia that may be associated with this condition. This article reports the application of a bipolar hemiarthroplasty and acetabular allograft reconstruction for a 32-year old woman with congenital dysplasia and degenerative joint disease of the hip secondary to de Lange''s syndrome. On admission, she was in considerable pain and unable to bear weight on the affected extremity. Her Harris hip score was 25. Following surgical intervention and a well-designed plan of rehabilitation, the patient''s functional status improved markedly. Her Harris hip score was 72, and her pain was alleviated.     

Improved immediate function of renal allografts with Belzer perfusate

The characteristics of 254 cadaveric kidneys were evaluated and the incidence of immediate function identified. The Belzer perfusate was used primarily (n = 140) and secondarily (n = 14) in combination with pulsatile machine perfusion. These two groups were compared with a previous group of kidneys machine-perfused with silica gel (cryoprecipitated human plasma). The incidence of immediate function of the group primarily perfused with Belzer perfusate was statistically significantly improved over that of the silica gel. The secondarily perfused Belzer group, "imported" kidneys previously preserved with simple cold storage, had notably longer periods of preservation and higher resistances on the machine. However, 100% of this group functioned immediately. Other findings in this study show that the Belzer perfusate allows for improved parenchymal function posttransplant, as noted by a more rapid clearance of serum creatinine posttransplant. When comparing the immediate function group with those suffering early dysfunction, there is a statistically significant increased resistance on the machine in the latter group. This allows for prediction of immediate function based on perfusion characteristics of the kidney. The Belzer perfusate, composed of metabolic substrates for high-energy phosphate production, improves the incidence of immediate function in machine-perfused kidneys, as well as improved qualitative function posttransplant. It also is effective as a "rescue" mechanism in previously simple cold-stored (ATP-depleted) kidneys.     

Experimental staphylococcal endocarditis and aortitis

Summary The initial colonization, byStaphylococcus aureus, of the catheter damaged aortic valve and aorta of the rabbit, was examined by light and electron microscopy at 15 min, 3 h and 24 h post inoculation (PI). At 15 min PI, the majority of bacteria (80%) were located on the lateral surfaces of the thrombic vegetations while 20% were attached directly to the connective tissue of the aortic valve and aorta in areas where the endothelial lining was disrupted. By 3 h the bacteria on the thrombic vegetations were covered by fibrin. At this time, the bacteria both within the vegetations and on the surface of the vasculature were undergoing multiplication to form small groups. The precipitation of thrombus around the bacteria attached to the surface of the aorta to form microscopic infected vegetations had occurred by 24 h PI. The colonizing bacteria did not elicit any phagocytic response. The colonization of the cardiovasculature byStaph. aureus did not necessarily require pre-existing vegetations.     

Staphylococcal exopolysaccharides inhibit lymphocyte proliferative responses by activation of monocyte prostaglandin production.

The glycocalyx (exopolysaccharides) of Staphylococcus epidermidis has been reported to inhibit a variety of host defense mechanisms. We have examined the inhibitory effects of glycocalyx on the proliferation of human peripheral blood mononuclear cells (PBMC) and the mechanism of this inhibition. Glycocalyx isolated and partially purified under endotoxin-free conditions from defined liquid medium cultures of S. epidermidis and Staphylococcus lugdunensis inhibited the proliferative response of PBMC when added to cultures at 10 to 100 micrograms/ml. Glycocalyx-mediated inhibition of phytohemagglutinin-stimulated proliferation of PBMC required the presence of plastic-adherent peripheral blood monocytes. Culture supernatants of monocytes stimulated with glycocalyx contained a soluble factor that inhibited the proliferation of monocyte-depleted PBMC. This soluble inhibitory factor was not produced in the absence of glycocalyx or in the presence of both glycocalyx and indomethacin. Analysis of the supernatants of cultures of adherent monocytes revealed that glycocalyx from S. epidermidis and from S. lugdunensis could activate monocyte production of prostaglandin E2 (PGE2), human interleukin-1, and tumor necrosis factor alpha. The addition of purified PGE2, at the same levels of PGE2 (greater than or equal to 10(-9) M) generated in the monocyte cultures, to PBMC cultures resulted in a similar inhibition of proliferative responses. It is concluded that, contrary to previous suggestions, the bacterial glycocalyx does not have a direct inhibitory effect on T lymphocytes. However, it does appear that glycocalyx from coagulase-negative staphylococci can activate monocyte PGE2 production and that it is this activity that in turn contributes to the inhibition of T-cell proliferation.     

Effect of delayed specimen processing on cytomegalovirus antigenemia test results.

Blood samples held at either 4 degrees C or room temperature for 1 day had similar mean decreases in number of cytomegalovirus antigenemia-positive cells (52 to 55%) and similar false-negative test results (13 to 14%). After 2 days, samples held at 4 degrees C showed no further decline, whereas samples held at room temperature had a mean 81% decrease in positive cells, a 32% false-negative rate, and a more marked deterioration in cell morphology.     

Randomized controlled trial of brief cognitive behaviour therapy versus treatment as usual in recurrent deliberate self-harm: the POPMACT study

BACKGROUND: We carried out a large randomized trial of a brief form of cognitive therapy, manual-assisted cognitive behaviour therapy (MACT) versus treatment as usual (TAU) for deliberate self-harm. METHOD: Patients presenting with recurrent deliberate self-harm in five centres were randomized to either MACT or (TAU) and followed up over 1 year. MACT patients received a booklet based on cognitive behaviour therapy (CBT) principles and were offered up to five plus two booster sessions of CBT from a therapist in the first 3 months of the study. Ratings of parasuicide risk, anxiety, depression, social functioning and global function, positive and negative thinking, and quality of life were measured at baseline and after 6 and 12 months. RESULTS: Four hundred and eighty patients were randomized. Sixty per cent of the MACT group had both the booklet and CBT sessions. There were seven suicides, five in the TAU group. The main outcome measure, the proportion of those repeating deliberate self-harm in the 12 months of the study, showed no significant difference between those treated with MACT (39%) and treatment as usual (46%) (OR 0.78, 95% CI 0.53 to 1.14, P=0.20). CONCLUSION: Brief cognitive behaviour therapy is of limited efficacy in reducing self-harm repetition, but the findings taken in conjunctin with the economic evaluation (Byford et al. 2003) indicate superiority of MACT over TAU in terms of cost and effectiveness combined.