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Biomedical subjects

E Shapiro

Publications and source records attributed to E Shapiro.

315 records · Page 18Linked to original sources
PubMedDate not supplied

Potential for localized, adjustable deep heating in soft-tissue environments with a 30-beam ultrasonic hyperthermia system.

Initial heating rates (degrees C/min) along parallel tracks at depths of 1-14 cm in a static, muscle-like phantom were determined from time-temperature profiles obtained with 'Helios', a 30-beam ultrasonic hyperthermia system developed by Varian Associates. Data were taken at a single operating frequency of 556 kHz, for different sets of focal plane ring diameters of the four-ring array applicator, different levels of transducer driving power and two different focal plane depths, 6 cm and 9 cm. In each experiment, at each point of temperature measurement, analysis of temperature versus time data over a 2 min heating interval permitted separation of the desired phantom heating from artefactual heating resulting primarily from absorption of transverse (shear) waves produced at phantom-metal probe catheter interfaces. The results of the studies conducted suggest that in a non-translating carriage mode, Helios can produce axially and laterally localized deep heating in soft tissues for tissue volumes of lateral dimension up to a minimum of 4 cm and tissue depths of at least 11 cm. The results obtained also suggest that Helios can produce laterally localized heating to tissue depths of at least 11 cm without excessive heating of superficial soft-tissue layers, for tissue volumes of lateral dimension up to a minimum of 8 cm. The methodology used in the phantom studies was applied to the production of localized heating in the right lobe of the liver of adult pigs. Temperature versus time profiles obtained in the in vivo studies indicated that, for the set of system parameters employed, concentration of ultrasonic power at greater depths in the liver (e.g. 10.5 cm versus 5 cm) could be achieved, suggesting that Helios should be able to produce localized heating of targeted hepatic volumes when its operating parameters are selected in accordance with effective treatment planning techniques.

Animals↗
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Heating patterns of the Helios ultrasound hyperthermia system.

Thermal dosimetry studies of the Helios ultrasound system were performed in a tissue-equivalent phantom and in porcine tissues in vivo. SAR distributions in the phantom demonstrate the adjustability of the power deposition pattern from the 50 cm diameter annular array of 30 transducers. Examples are given of well-localized SAR patterns (< 3 cm diameter) in the phantom, and of peripherally enhanced (doughnut-shaped) SAR patterns up to 10 cm in diameter at the focal plane. In vivo trials in porcine thigh muscle demonstrate the ability of the Helios system to produce regions of therapeutic heating (42-45 degrees C) as small as 20 cm3 and as large as 200 cm3 at depths of greater than 10 cm at a frequency of 0.5 MHz.

Animals↗
PubMedDate not supplied

Evaluation of treatment with single-dose ampicillin/sulbactam with probenecid or ceftriaxone in patients with uncomplicated gonorrhea.

This study compared ampicillin/sulbactam plus probenecid with ceftriaxone for treatment of uncomplicated gonorrhea. Of the 297 men and women who were enrolled and randomized to receive either ampicillin/sulbactam (1.0 g/0.5 g) with probenecid (1 g) or ceftriaxone (0.25 g), 274 patients were evaluable. Both ampicillin/sulbactam and ceftriaxone were administered by intramuscular injections. Patients were gonococcal contacts, had positive culture results for Neisseria gonorrhoeae, or had clinical evidence of gonorrhea. Specimens for gonococcal cultures were collected from the cervix (female patients), urethra, rectum, and pharynx at pretreatment and test-of-cure visits. The presence of N. gonorrhoeae and a test-of-cure visit were required for drug efficacy analysis. Of the 274 evaluable patients, 195 (71.2%) had positive culture results for N. gonorrhoeae. Cure was achieved in 93 (94.9%) of 98 patients receiving ampicillin/sulbactam with probenecid and in 96 (99.0%) of 97 patients receiving ceftriaxone. Penicillinase-producing N. gonorrhoeae strains were found in 21 (10.8%) patients; these were eradicated by either ampicillin/sulbactam with probenecid (N = 9) or ceftriaxone (N = 12). Overall, the two drug regimens were very well tolerated and no serious adverse effects were noted. Ampicillin/sulbactam with probenecid may be useful as single-dose therapy in patients with uncomplicated genitorectal gonorrhea.

Adolescent↗
PubMedDate not supplied

Increased infant mortality in Jersey City.

The infant mortality rate for 1982 in Jersey City, a medium-sized urban community, was found to have increased sharply from that for 1981. An investigation by health officials revealed that the increase occurred only among infants delivered to Jersey City residents at a large local municipal hospital. An increase in the incidence of newborns with birth weights of 501-1,000 grams (g) and a decrease in their survival rate accounted for much of the increase. Although local increases in infant mortality are reported in the lay press, the articles usually lack any meaningful analyses. Furthermore, investigations of such increases have not been described in the medical literature. This report describes the investigation of the rise in infant mortality for Jersey City, demonstrates how local officials can approach the problem, and indicates how essential the availability of linked birth and infant death records are to the effort.

Delivery, Obstetric↗
PubMedDate not supplied

Proton MR spectroscopy of childhood adrenoleukodystrophy.

PURPOSE: To determine the potential of proton MR spectroscopy to monitor patients with childhood-onset cerebral adrenoleukodystrophy (COCALD). METHODS: Single-voxel MR spectroscopy was performed in 16 children with COCALD (24 examinations) who had had no treatment and in 7 children (13 examinations) who had had bone marrow transplantation. RESULTS: In the untreated children with clinically active COCALD, the metabolite ratios N-acetyl-aspartate (NAA)/creatine (Cr) and NAA/choline (Ch) were decreased while Ch/Cr was increased. This trend agrees well with those reported by other researchers, although different experimental sequences and parameters were used in our study. Comparison of these ratios with those from a control group yielded significant differences in the occipital region. In the children who were clinically stable after bone marrow transplantation, the mean levels of the three ratios were between those of the control subjects and the patients with untreated COCALD: the differences in these ratios approached significance. In patients who had been monitored periodically, MR spectroscopy metabolite ratios correlated well with the dementia rating score, reflecting clinical status. CONCLUSION: There is good correlation between MR spectroscopy metabolite ratios and a patient's clinical status. MR spectroscopy appears to be a useful, noninvasive tool to monitor patients with adrenoleukodystrophy, and it increases the overall sensitivity of MR techniques in clinical applications.

Adolescent↗