Magnetic resonance profiling of human skin in vivo using GARField magnets.

It is shown that one-dimensional magnetic resonance imaging (MRI-profiling) of human forearm and side-of-hand skin in vivo is possible using GARField magnets. Strong profile contrast originating from differing molecular mobility is seen for stratum corneum and viable epidermis. The first in vivo spatially-resolved field-gradient measurements of water self-diffusivity, D, in the stratum corneum (2.0 x 10(-6) cm(2)/s) and viable epidermis (8.5 x 10(-6) cm(2)/s) are reported. Also reported are spatially resolved measurements of the (1)H spin-lattice relaxation time, T(1), the spin-spin relaxation time, T(2). It is further shown that the application of moisturizing agents to the skin noticeably affects the profiles. However, universal behavior is not seen as both signal increases and decreases are observed dependent on agent and volunteer.

GARField magnetic resonance profiling of the ingress of model skin-care product ingredients into human skin in vitro.

A preliminary study of the ingress of mineral oil, decanol, and glycerine into samples of human abdominal skin tissue in vitro made using magnetic resonance profiling with a GARField magnet is reported. Two layers, each circa 50 microm thick and attributed to stratum corneum and viable epidermis, are spatially resolved. Clear differences are observed in the magnetic resonance response of these layers arising from the application of the model skin-care product ingredients. In the case of decanol and glycerine, it is suggested that the profiles show evidence for the effects of moisturization, as distinct from hydration. In the case of glycerine, the effective ingress diffusion coefficient is calculated to be 1.3 +/- 0.5 x 10(-9) cm2s(-1).

Intermediate term results of total lymphoid irradiation for the treatment of non-specific graft dysfunction after heart transplantation.

BACKGROUND: A proportion of heart transplant recipients develop poor graft function in the absence of cellular infiltrate in endomyocardial biopsies or transplant associated coronary artery disease. The condition has a poor prognosis and its aetiology is poorly understood. We report encouraging intermediate term results with total lymphoid irradiation (TLI) in the management of this condition. METHODS: Eleven adult cardiac transplant recipients who developed severe allograft dysfunction (NYHA class-4) at a median period of 4 months after orthotopic heart transplantation were successfully treated with TLI. Endomyocardial biopsies and coronary angiography were normal in each patient and biventricular failure developed in spite of immunosuppression with Cyclosporin-A, Azathioprine, oral Prednisolone, Cyclophosphamide and intravenous Methylprednisolone therapy. Total lymphoid irradiation was given with standard Mantle and inverted Y-fields over ten treatments to achieve a cumulative dose of 8 Gy. RESULTS: Each patient had a significant improvement in clinical response and in ventricular performance within 2 months of commencing TLI. Nine patients are currently well (four NHYA class-1, five NHYA class-2) at 4-48 (median 26) months following TLI. Two patients died; one from bacterial septicaemia and one as a consequence of chronic renal failure. Three patients developed opportunistic infection which was successfully treated with appropriate antimicrobial agents. An Ebstein-Barr virus associated lymphoproliferative disorder occurred in one patient and was successfully treated by reduction in immunosuppression and high dose Acyclovir. Two patients developed transient bone marrow suppression. CONCLUSION: The intermediate term results of TLI in the management of poor graft function in cardiac transplant recipients with normal endomyocardial biopsies and coronary angiography are encouraging. Although complications of opportunistic infection, bone marrow suppression and lymphoproliferative disorder occurred, treatment was successful in each case.

Is routine post-operative surveillance for cytomegalovirus infection following heart transplantation necessary?

OBJECTIVE: Cytomegalovirus infection (CMV) is an important cause of morbidity and mortality following cardiac transplantation. The purpose of the present study was to ascertain whether routine post-operative screening for CMV infection influenced clinical management. METHODS: Laboratory and case notes of 220 patients who received cardiac transplantation between November 1986 and October 1996 were reviewed. The range of follow-up was one to 120 (median 36) months. CMV surveillance involved blood tests for early antigen detection weekly for the first 6 post-operative weeks, fortnightly thereafter until the end of the third post-operative month and every 6 weeks to the end of the first post-operative year. Otherwise monitoring was performed if the patients had clinical symptoms suggestive of CMV infection. CMV sero-negative IgG recipients (R) of sero-positive IgG donor (D) organs and/or blood products received hyper-immune gammaglobulin for the first three post-operative months. Four patient groups were noted, namely R+D+ (59 patients), R+D- (70 patients), R-D+ (35 patients) and R-D- (56 patients). RESULTS: CMV antigenaemia was present in 40% (89) of patients and 48% (43) of these patients developed clinical features of CMV infection and received ganciclovir therapy. The distribution of clinical CMV infection requiring treatment was 25% (9/35) in the R+D- group, 50% (16/32) in the R+D+ group and 85% (18/22) in the R-D+ group. None of the patients in the R-D- group developed CMV antigenaemia. Forty six (52%) patients who were CMV antigen positive but who did not develop symptoms were not treated with ganciclovir and have remained well. CONCLUSION: Our results suggest that routine screening for CMV following cardiac transplantation is unnecessary. Surveillance did not result in the instigation of treatment for CMV unless there were associated clinical features of CMV infection.

Absence of bradycardic response to apnea and hypoxia in heart transplant recipients with obstructive sleep apnea.

In patients with obstructive sleep apnea, the vagal stimulation caused by inspiration against the upper airway obstruction results in sinus bradycardia during the apnea followed by a reflex tachycardia at apnea termination. We report on five heart transplant recipients with obstructive sleep apnea who demonstrated no change in baseline heart rate in spite of marked hemoglobin oxygen desaturation, presumably on account of parasympathetic denervation of the allograft. Heart transplant recipients with obstructive sleep apnea may be at an increased risk of development of potentially fatal ventricular arrhythmias if the allograft is unable to respond appropriately to hypoxia. Should cardiac parasympathetic reinnervation occur, prospective polysomnography may be a marker for this process in these patients.

Total lymphoid irradiation as rescue therapy after heart transplantation.

BACKGROUND: Allograft dysfunction develops in a proportion of heart transplant recipients without significant cellular infiltrate in endomyocardial biopsies and with normal coronary arteries at angiography. The mechanisms responsible for this presentation are unclear, and the prognosis is poor. We report encouraging experience with total lymphoid irradiation given in addition to cyclosporine A, cyclophosphamide, and prednisolone therapy in three heart transplant recipients with poor graft function with normal endomyocardial biopsies and coronary angiography. METHODS: Three patients who had severe allograft dysfunction after orthotopic heart transplantation, with normal endomyocardial biopsies and coronary angiography, were successfully treated with total lymphoid irradiation. Biventricular failure developed in each patient despite immunosuppression with cyclosporine A, azathiaprine, oral prednisolone, cyclophosphamide, and intravenous methylprednisolone therapy. Total lymphoid irradiation was given with standard mantle and inverted y fields over 10 treatments to achieve a cumulative dose of 8 Gy. RESULTS: Each patient had a significant improvement in clinical response and in ventricular performance after total lymphoid irradiation, which was well tolerated in each case. The patients remain well at 8, 9, and 12 months after completion of treatment. CONCLUSIONS: Total lymphoid irradiation should be considered as adjunct therapy to conventional immunosuppression for heart transplant recipients with poor graft function in the absence of cellular rejection or coronary artery disease.