Evidence for frequency-dependent arterial damage in vibrated rat tails

The effects of single 4-hr bouts of continuous 30, 60, 120, and 800 Hz tail vibration (49 m/sec2, root mean squared) were compared to assess frequency-amplitude-related structural damage of the ventral caudal artery. Amplitudes were 3.9, 0.98, 0.24, and 0.0055 mm, respectively. Vibrated, sham-vibrated, and normal arteries were processed for light and electron microscopy. The Curry rat tail model of hand-arm vibration (Curry et al. Muscle Nerve 2002;25:527-534) proved well-suited for testing multiple frequencies. NFATc3 immunostaining, an early marker of cell damage, increased in smooth muscle and endothelial cells after 30, 60, and 120 Hz but not 800 Hz. Increased vacuolization, which is indicative of smooth muscle contraction, occurred for all frequencies except 800 Hz. Vacuoles increased in both endothelial and smooth muscle cells after 60 and 120 Hz. Only 30 Hz showed pronounced smooth muscle cell vacuolization along the internal and external elastic membranes, suggesting stretch-mediated contraction from the large amplitude shear stress. Discontinuities in toluidine blue staining of the internal elastic membrane (IEM) increased for all frequencies, indicating vibration-induced structural weakening of this structure. Patches of missing IEM and overlying endothelium occurred in approximately 5% of arteries after 60, 120, and 800 Hz. The pattern of damage after 800 Hz suggests that the IEM is disrupted because it resonates at this frequency. Vibration acceleration stress and smooth muscle contraction appear to be the major contributors to arterial damage. The pattern of vibration-induced arterial damage of smooth muscle and endothelial cells is frequency-amplitude-dependent.     

Accelerating the return to work (RTW) chances of coronary heart disease (CHD) patients: part 1--development and validation of a training programme

PURPOSE: Conventional phase II cardiac rehabilitation (CR) programmes have not resulted in an improvement in returning coronary heart disease (CHD) patients to work in over 35 years. This 4 year field-initiated research, sponsored by the National Institute on Disability and Rehabilitation Research, compares conventional CR programmes with a low-intensity CR programme that simulates elements of work (job-simulated CR programme) in terms of return to work (RTW) and physiological conditioning. The effect of training on physical capabilities of patients participating in the job-simulated CR programme was also of equal interest. METHOD: Thirty patients (15 bypass and 15 angioplasty; 15 males and 15 females) participated in a conventional CR programme (control group). The job-simulated CR programme included 15 male and 2 female bypass and angioplasty patients (experimental group). Patients in the control group underwent regular aerobic exercise training (treadmill and bicycle). Experimental group patients participated in a series of low-intensity exercises such as progressive time exercises, flexibility exercises, and dexterity exercises. RESULTS: All patients participating in the low-intensity job-simulated CR programme returned to the same job they held at the onset of myocardial infarction (MI). In contrast, only 60% of the control group patients returned to work; at least one-third of these did not go back to the same job they held at the onset of M1. Patients in both groups achieved the same level of physiological conditioning. The physical functional capabilities of the experimental group patients improved significantly throughout training. CONCLUSION: The results of this field-study lead to the conclusion that a low-intensity phase II cardiac rehabilitation programme that simulates elements of work may be far superior to conventional endurance exercise-based cardiac rehabilitation programmes in terms of returning patients to work. Such a programme also strengthens patients, improving their physical capabilities, without compromising their physiological conditioning.     

Metastatic Neuroendocrine Carcinoma Presenting as a "Superscan" on 68Ga-DOTANOC Somatostatin Receptor PET/CT

ABSTRACT: PET/CT imaging using Ga-labeled somatostatin analogs has become a popular noninvasive diagnostic modality in the workup of patients with neuroendocrine tumors. A 65-year-old man with pancreatic neuroendocrine tumor with confirmed liver metastases on conventional imaging underwent restaging Ga-DOTANOC PET/CT to monitor response to cold octreotide therapy. Previous PET/CT had shown presence of multiple liver and skeletal metastases along with a primary pancreatic tumor showing intense tracer uptake. The present PET/CT study showed an increase in number and uptake of the metastatic lesions suggestive of progressive disease resulting in the appearance of a superscan.     

Automated spectral analysis I: Formation of a priori information by spectral simulation

A spectral simulation method is described for generating a priori information for use in parametric spectral analysis. The method makes use of GAMMA (S. A. Smith, T. O. Levante, B. H. Meier, R. R. Ernst, J. Magn. Reson., 106A, 75–105, 1994), a programming environment that facilitates simulation of magnetic resonance phenomena. The input parameters consist of the chemical shifts and scalar spin-coupling constants for the compounds to be analyzed, the acquisition pulse sequence, and the field strength used. The resultant spectral information consists of the relative amplitude, frequency, and phase of all resonances, which are stored in a spectral database. This procedure can be rapidly and conveniently modified to reflect different acquisition parameters and data analysis requirements.     

Effects of calcineurin inhibitors on an in vitro assay for chronic urticaria

BACKGROUND: Chronic urticaria is a common skin disorder, which causes considerable morbidity. In approximately 40% of cases, patients have an autoimmune disorder in which functional antibodies cause degranulation of mast cells and basophils, and C5a complement augments this in varying amounts from patient to patient. Since the calcineurin inhibitor ciclosporin has been used in chronic autoimmune urticaria, we examined the effect of ciclosporin and other drugs on the release of histamine from basophils when stimulated by sera from patients with chronic autoimmune urticaria. METHODS: Leucocytes from healthy donors were isolated and incubated in varying concentrations of ciclosporin, ascomycin, methotrexate, diphenhydramine or hydroxyzine for 30 min prior to stimulation with serum from urticaria patients known to have functional immunoglobulin (Ig)G antibodies directed against the alpha subunit of the IgE receptor. Histamine release was then measured. RESULTS: Pre-incubating cells with ciclosporin and ascomycin produced dose-dependent inhibition of histamine release when cells were stimulated by sera of urticaria patients, by purified IgG from these sera, but not by C5a. Inhibition was not prevented by C5a receptor blocking antibodies. No inhibition was seen with methotrexate, diphenhydramine or hydroxyzine. CONCLUSIONS: This is the first demonstration of inhibition of histamine release by calcineurin inhibitors employing sera of patients with chronic autoimmune urticaria. These drugs may work by interfering with intracellular signalling in cells following cross-linking of the IgE receptor, but not following stimulation of the C5a receptor.     

Mycoses in India—study in Madras

The incidence of mycoses is high in Madras accounting for over 13% of dermatoses diagnosed in a three-year period. Dermatophytoses (tinea corporis and tinea cruris) and pityriasis versicolor were most common in May and October. A correlation was observed between these infections and environmental temperature, humidity and rainfall. Most cases of all dermatophytoses except tinea capitis were recorded between 10 and 30 years of age but the latter was most common between one and 10 years. Males were predominantly affected with all except tinea axillaris, candidiasis and piedra. The incidence of piedra and deep mycoses was low.