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Biomedical subjects

M Rothman

Publications and source records attributed to M Rothman.

At least 37 records · Page 2Linked to original sources
PubMed1997

One balloon approach for optimized Palmaz-Schatz stent implantation: the MUSCAT trial.

BACKGROUND: After stent deployment, larger balloons are frequently needed to optimize stent expansion according to angiographic and intravascular ultrasound (IVUS) criteria. The objective of this trial was to assess the feasibility and safety of a single-balloon approach for predilation, stent implantation, and optimization with a differential-compliant balloon allowing for focal overexpansion. We also evaluated the achieved degree of stent expansion according to IVUS criteria. METHODS AND RESULTS: Forty-seven consecutive patients with 50 lesions received single or multiple Palmaz-Schatz coronary stents. The final angiographic diameter stenosis was -2.6 +/- 12.6% (reference diameter, 2.89 +/- 0.44 mm), and the residual lumen area stenosis (IVUS) was 13.0 +/- 12.3% (reference area 10.8 +/- 3.0 mm2). This result was achieved in two steps (first angiographic, then IVUS-guided stent optimization). The balloon inflation pressure increased from 13.1 +/- 3.0 bar at step 1 to 16.1 +/- 3.0 bar at step 2, which resulted in a balloon to artery ratio of 0.97 +/- 0.12 and 1.10 +/- 0.15, respectively, at the low-compliant peripheral balloon segments. The more compliant central balloon segments showed a balloon to artery ratio of 1.09 +/- 0.17 and 1.28 +/- 0.17, respectively. The primary success rate for stent deployment was 94%. Acute complications included two type A and one type B dissection without clinical sequelae. CONCLUSIONS: The single-balloon approach for stenting is feasible and safe. The acute result is comparable to that of other studies with IVUS-guided stent optimization, the primary success rate, however, is slightly lower with the presently available catheter.

Adult↗
PubMed1997

Orbital trauma.

The globe and orbit constitute a very small portion of the body; however, trauma to this region assumes critical importance due to the high value we place on vision. The evaluation of orbital trauma has progressed rapidly with the development and wide distribution of computer-assisted imaging. Plain radiography, angiography, computed tomography (CT), and magnetic resonance imaging (MRI), may all be used in the evaluation of orbital trauma and the search for foreign bodies.

Diagnosis, Differential↗
PubMed1996

Effects of alcohol ingestion on estrogens in postmenopausal women.

OBJECTIVE: To determine if moderate alcohol drinking increases circulating estradiol levels in postmenopausal women who are taking estrogen replacement. DESIGN: Randomized, double-blind, placebo-controlled crossover study of the effects of alcohol ingestion on plasma estradiol and estrone. SETTING: Inpatient Clinical Research Center. PARTICIPANTS: Twelve healthy postmenopausal women receiving oral estrogen (estradiol, 1 mg/day) and progestin (medroxyprogesterone acetate) replacement therapy were compared with 12 postmenopausal women who were not using estrogen replacement therapy (ERT). INTERVENTION: Each group drank alcohol (0.7 g/kg) and an isoenergetic (isocaloric) placebo (randomized sequence) on consecutive days. Women who were taking ERT were studied during the estrogen-only portion of their replacement cycle, and estrogen was administered each evening at 2100 hours. MAIN OUTCOME MEASURE: The impact of alcohol ingestion on plasma estradiol and estrone levels. RESULTS: Alcohol ingestion lead to a 3-fold increase in circulating estradiol in women on ERT; however, alcohol did not change estradiol significantly in control women who were not on ERT. In women using ERT, estradiol levels increased from 297 to 973 pmol/L (81 to 265 pg/mL) within 50 minutes (P<.001) during the ascending limb of the blood alcohol curve and remained significantly above baseline for 5 hours (P<.001). No significant increase in circulating estrone was detected in either group. However, estrone levels decreased after alcohol and placebo in women on ERT (P<.05). Blood alcohol levels did not differ significantly in women who used ERT and those who did not. Peak blood alcohol levels of 21 mmol/L were attained in each of the 2 groups within 50 to 60 minutes after drinking began. Changes in estradiol were significantly correlated with changes in blood alcohol levels on both the ascending (P<.001) and descending (P<.001) limb of the blood alcohol curve. CONCLUSIONS: Acute alcohol ingestion may lead to significant and sustained elevations in circulating estradiol to levels 300% higher than those targeted in clinical use of ERT. Potential health risks and benefits of the interactions between acute alcohol ingestion and ERT should be further evaluated.

Alcohol Drinking↗
PubMed1996

Interventional cardiology in Europe 1993. Working Group on Coronary Circulation of the European Society of Cardiology.

An annual survey on cardiac interventions in Europe is performed by the working group on Coronary Circulation of the European Society of Cardiology with the help of the national societies of cardiology. A questionnaire about cardiac interventions in 1993 was mailed to a representative of the national societies of 35 members of the European Society of Cardiology. The data collection of coronary interventions was delayed by slow backreporting and from 10 of the 35 national members data were missing or grossly incomplete. They were excluded from the analysis. CORONARY ANGIOGRAPHY: A total of 756,822 coronary angiograms were reported resulting in an incidence of 1146 +/- 1024 per 10(6) inhabitants, ranging from 24 (Romania) to 3499 (Germany). This represents an increase of 12% compared to 1992. Germany (279,882 cases), France (157,237), the United Kingdom (77,000), Italy (44,934) and Spain (37,591) registered 79% of all the coronary angiograms performed. PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOPLASTY: A total of 183,728 percutaneous transluminal coronary angioplasty cases were reported in 1993, 24% more than in 1992. On average, they accounted for 18 +/- 7% (range 8 (Romania) to 35% (Sweden) of the coronary angiograms. Most of these percutaneous transluminal coronary angioplasties (82%) were confined to a single vessel. In 13% only, percutaneous transluminal coronary angioplasty took place immediately after the diagnostic study. Adjusted per capita. Germany ranks first with 873 percutaneous transluminal coronary angioplasties per 10(6) inhabitants, followed by France (737), Holland (725), Belgium (713), and Switzerland (665). The European mean of percutaneous transluminal coronary angioplasties per 10(6) inhabitants was 270 +/- 279, representing an increase of 14% compared with 1992. A major in-hospital complication was reported in 3.8% of the patients undergoing percutaneous transluminal coronary angioplasty: 0.6% hospital deaths, 1.5% emergency coronary artery bypass grafting, and 1.7% myocardial infarctions. NEW DEVICES: In 1993 stents were implanted in 6444 patients (3.5% of all percutaneous transluminal coronary angioplasty patients), equally distributed between bail-out situations (53%) and elective procedures. The 14 stent implanting countries showed a mean increase in incidence of coronary stenting of 53% compared with 1992. Other interventional devices were applied in 7045 cases, 3.8% of all percutaneous transluminal coronary angioplasty cases. Coronary ultrasound (2194 cases) and coronary angioscopy (380 cases) were performed infrequently. NON-CORONARY INTERVENTIONS: Valvuloplasties were most frequently performed non-coronary interventions European countries performed more than 300 valvuloplasties each in 1993. Most of them were mitral valvuloplasties in southern countries. CONCLUSIONS: Although partial backreporting might conclusions, several findings of this survey are noteworthy for the participating countries: The number of percutaneous taneous transluminal coronary angioplasties is universally increasing. There is an extremely wide range of coronary angiography and percutaneous translumina, coronary angioplasties performed per population. The most common additional procedure is a stent implantation while other new devices are only rarely applied. Mitral valvuloplasty is the most frequently performed non-coronary intervention.

Angioplasty, Balloon, Coronary↗
PubMed1996

Histopathology and CT analysis of partially resected middle turbinates.

Thirty-eight partial middle turbinate resections from 20 patients undergoing endoscopic sinus surgery were evaluated by histopathology of mucosa and bone and by computed tomography (CT) appearance prior to resection. Histopathologic analysis revealed not only mucosal inflammation but also chronic osteitis of the bone in all patients with sinus disease. The preoperative CT was accurate in predicting turbinate osteitis when the scans displayed advanced grades III and IV disease. These findings suggest that in advanced disease, conservative partial middle turbinate resections may be necessary to remove chronically infected bone from the osteomeatal complex. Because it is unsafe to remove all of the middle turbinate, consideration should also be given to long-term antibiotic therapy to treat the osteitis found in advanced disease.

Chronic Disease↗
PubMed1996

Cost utility of the multichannel cochlear implants in 258 profoundly deaf individuals.

Cost utility analysis is a method of cost-effectiveness analysis which provides results in terms of cost per quality-adjusted life-year (QALY). Cost utility for the multichannel cochlear implant was calculated using Ontario Health Utilities Index data from 229 Nucleus 22-channel implant users and 32 cochlear implant candidates awaiting surgery. The health utility of the implanted group was greater than that of the candidate group by 0.204 (P<.0001). Use of this figure in a cost utility calculation indicates that cochlear implantation costs approximately $15,928 per QALY provided. Sensitivity analysis, a technique which systematically varies the assumptions underlying the calculations, suggests a range for the true value of between $12,000 and $30,000. This compares very favorably with other medical interventions. It is concluded that profound hearing loss has a significant effect on quality of life, and measurement of the changes that result from cochlear implant use indicates that this technology provides significant improvements and is quite cost-effective.

Aged↗
PubMed1996

Pediatric brain tumors express multiple receptor tyrosine kinases including novel cell adhesion kinases.

We have used the polymerase chain reaction to clone and characterize growth factor receptor tyrosine kinases (RTKs) expressed in 3 pathologically distinct pediatric brain tumors, an anaplastic ependymoma, a glioblastoma multiforme and a primitive neuroectodermal tumor (PNET). These neoplasms are presumed to be derived from embryonic neuroepithelial precursor cells of the central nervous system. This cloning demonstrated expression of 24 distinct kinase genes: 16 receptor type kinases and 8 nonreceptor type kinases. The expression of 6 receptors, including Hek2, IRR, Ryk, FGFR3, and 2 members of the newly identified cell adhesion kinase receptor family, DDR and TKT, in such tumors has not been reported previously. Northern analysis of mRNA levels revealed DDR expression in 6 of 7 pediatric brain tumors including an ependymoma, PNET, glioblastoma and astrocytoma, and also in an adult pheochromocytoma. Thus, the DDR cell adhesion kinase may be widely expressed in pediatric brain tumors. Also, PCR cloning may be an effective procedure for characterizing RTKs in clinical tissue samples and revealing the expression of novel RTK species.

Adrenal Gland Neoplasms↗
PubMed1996

Stroke in Williams syndrome.

BACKGROUND: Williams syndrome is a genetic disorder characterized by a high incidence of heart disease, arterial stenosis, and hypertension. Despite these features, cerebrovascular accidents have been described only recently and only in association with stenoses of the cerebral vasculature. CASE DESCRIPTION: A 19-year-old girl with Williams syndrome developed an acute-onset hemiparesis. MRI demonstrated an infarct involving the internal capsule and putamen. No stenotic areas were seen on angiography. CONCLUSIONS: Stroke should be considered as a possible consequence of Williams syndrome, even in the absence of stenoses of the cerebral vasculature. Comparison of this case with those previously reported in the literature emphasizes the multiplicity of features in Williams syndrome that can contribute to the risk of stroke.

Adult↗
PubMed1996

A new decision model for cost-utility comparisons of chemotherapy in recurrent metastatic breast cancer.

In the absence of comparative clinical and pharmacoeconomic trial data for docetaxel versus paclitaxel as second-line therapy for patients with anthracycline-resistant metastatic breast cancer, a computer-based decision-analysis model was designed to evaluate the comparative utility to patients of these two taxoids. The model used the Markov process to analyse disease states (response, stable disease, progressive disease) and toxicities (acute, cumulative) for each treatment during the period from commencement of up to six 3-weekly cycles of chemotherapy, to death. A cost-utility analysis was carried out using the model, with a probability, a cost and a utility determined for each health state. Response rates were obtained from clinical trial data supplemented by expert clinical opinion. Costs were taken from UK national databases and published sources and the published UK prices of docetaxel and paclitaxel. Utilities for the various health states were established by use of standard gamble and visual analogue methods assessed by 30 oncology nurses in the UK who were acting as proxy patients. The results of the model showed that response rate is the key parameter determining the utility and cost utility of treatments for metastatic breast cancer. Although the total per-patient cost associated with docetaxel was marginally higher than that for paclitaxel (8233 pounds vs 8013 pounds), the higher response rate associated with docetaxel produced an improvement in utility to the patient at an incremental healthcare cost that is acceptable according to available defined limits. Sensitivity analyses revealed that, although the model was sensitive to changes in response rate and drug costs, the cost-utility ratio for docetaxel versus paclitaxel varied within acceptable limits in response to all likely changes in key parameters. In summary, in the base case used in this model, docetaxel produces a substantially larger utility benefit than paclitaxel, at a small additional cost per QALY gained (equivalent to 7 pounds per additional day of perfect health).

Breast Neoplasms↗
PubMed1996

Fear of success among business students.

The concept of "Fear of Success" was measured with 352 male and female business students using the prompt, After first term finals, Ann(John) finds her(him)self at the top of her(his) Medical/Nursing school class. Analysis indicated a greater frequency of fear-of-success imagery among men than women and in particular to the John in Medical school and Ann in Nursing school cues. In addition, the Ann cue and the Medical school cue generated more fear-of-success responses among men than women.

Achievement↗
PubMed1995

Structural model of the phospholamban ion channel complex in phospholipid membranes.

Phospholamban is a 52 amino acid residue membrane protein involved with the regulation of calcium levels across sarcoplasmic reticulum membranes in cardiac muscle cells. The N-terminal 30 amino acid residues of the protein are largely hydrophilic and include two sites whose phosphorylation is thought to dissociate an inhibitory complex between phospholamban and Ca2+ ATPase. The C-terminal 22 amino acid residues are largely hydrophobic, anchor the protein in the membrane and are responsible for Ca2+ selective ion conductance. Specific interactions between the transmembrane domains stabilize a pentameric protein complex. We have obtained circular dichroism (CD), transmission Fourier transform infrared (FTIR) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectra of the full-length protein and have compared these results to those from a 28 residue peptide that includes the transmembrane domain. Both proteins reconstituted into phospholipid membranes are largely alpha-helical by CD and FTIR. Polarized ATR-FTIR measurements show that both the cytosolic and transmembrane helices are oriented perpendicular to the membrane plane with a tilt of 28 (+/- 6) degrees with respect to the membrane normal. This tilt angle is in close agreement to that calculated from a model for the transmembrane domain of phospholamban suggested by mutagenesis and molecular modeling. Phosphorylation does not significantly change the secondary structure or orientation of the protein. The pentameric complex is modeled as a left-handed coiled-coil of five long helices (40 (+/- 3) residues) that extend across the membrane from the lumenal carboxy terminus to the phosphorylation site in the cytoplasm. The helix bundle forms a perpendicular ion pore that may begin at a distance (17 to 29 A) from the membrane surface. Based on the above, we propose a mechanism by which phospholamban regulates Ca2+ levels across membranes that takes into account both its selective ion conductance and inhibitory association with the Ca2+ pump.

Amino Acid Sequence↗
PubMed1995

Localization of a misplaced coronary artery stent by magnetic resonance imaging.

Coronary artery stents have been developed to overcome arterial abrupt closure and restenosis following balloon angioplasty. Complications of stent insertion include loss of the device from its delivery system into the peripheral circulation. Certain types of stents are almost radiolucent, making localization of the lost devices difficult. Nonferromagnetic metallic biomedical implants induce alteration of the local magnetic field and this leads to loss of signal from the surrounding tissues. We have used this property to localize a misplaced coronary artery stent in a 53-year-old man who underwent unsuccessful stent insertion. A 0.5 Tesla magnetic resonance scanner was used to acquire gradient-echo and spin-echo images. An in vitro experiment was first carried out on a stent similar to that used in our patient to establish that it was nonferromagnetic and to determine the optimum imaging technique. Gradient-echo images with a relatively long echo time (22 ms) gave the largest area of signal loss around the stent, and this sequence was used for localization of the stent found in the patient's left profunda femoris artery. This was subsequently confirmed by digital radiography. We have demonstrated the convenience and practicality of using magnetic resonance imaging for the localization of a misplaced coronary artery stent in a patient. The technique is safe, noninvasive, and uses no ionizing radiation.

Angioplasty, Balloon, Coronary↗
PubMed1995

MRI of silicone vitreous ocular implants with phantom correlation.

We imaged two patients who had silicone oil injected their vitreous cavities. The images demonstrated an increased chemical shift artifact. We developed and tested an in vitro silicone oil model in an attempt to explain this. To our knowledge, this artifact has not been previously described. We constructed a phantom using medication cups containing water, lard and two types of silicone. Background control baths of water and lard were used to simulate different local environments. The phantoms were imaged with T1-and T2-weighted and T1-weighted fat suppression sequences. The artifacts were due to the pronounced chemical shift of silicone in relation to intraconal fat. Our model accurately reproduced our clinical images. Spectral analysis of the silicone model revealed different resonating frequencies for fat/silicone, thereby explaining the pronounced chemical shift artifact.

Artifacts↗
PubMed1995

Including deaths when measuring health status over time.

Measuring health status over time is problematic when some subjects die, because death does not have a defined value on most health status measures. This situation is different from the usual missing data problem because the health status of the dead is, in a sense, known. We examined eight strategies for incorporating deaths into such analyses using three health status measures taken from two data sets, after which we used computer simulation to explore more fully the effect of deaths. The strategies differed in the amount of influence given to the deaths, varying from none (deaths were discarded) to complete (mortality itself was the health measure). The strategies that gave less influence to deaths tended to show more favorable changes in health over time, and therefore, tended to favor the group that had more deaths. The strategies that were more influenced by death showed more negative changes over time and favored the group with fewer deaths. The choice of strategy should depend on the goals of an intervention. For health promotion studies, we recommend recoding the health variables to estimate the probability that a person will be healthy in 2 years (or in some other period that can be estimated from the data).

Aged↗
PubMed1994

Spinal epidural abscess with gadolinium-enhanced MRI: serial follow-up studies and clinical correlations.

We reviewed serial MRI with and without gadolinium-DTPA in eight patients with spinal epidural abscess and correlated the findings and the clinical manifestations. In four patients, diffuse abscesses spanned four vertebral bodies or more; the others had focal abscesses associated with osteomyelitis and/or diskitis. In three of the four patients with diffuse abscesses, MRI (NCMRI) showed diffuse encasement of the subarachnoid space. Contrast-enhanced MRI (CEMRI) demonstrated linear enhancement surrounding unenhanced pus. In the four patients with focal abscesses, CEMR delineated the inflammatory process more clearly than NCMR. On follow-up studies, decrease in abscess size and better visualization of the subarachnoid space correlated with clinical improvement in both diffuse and focal abscesses. Despite clinical improvement, contrast enhancement persisted in the disk or epidural space of three patients, and was thought to represent chronic granulomatous change or postsurgical scar. CEMR is very valuable for the initial diagnosis of an epidural abscess, particularly if it involves lengthy segments. During follow-up, CEMR can document responses to therapy, and provide information for determining appropriate treatment.

Abscess↗
PubMed1994

Accuracy of clinical examination versus computed tomography in detecting occult lymph node involvement in patients with oral epidermoid carcinoma.

PURPOSE: To determine the accuracy of clinical examination versus computed tomography (CT) scanning in detecting positive cervical lymph nodes (N) in patients with epidermoid carcinomas of the oral cavity, 27 patients with epidermoid carcinomas were reviewed. PATIENTS AND METHODS: The patients underwent 40 neck dissections, 20 with N- and 20 with N+ necks histologically. All patients were examined by the same clinician, and all CT scans were read by the same radiologist. Patients with clinical and CT N- necks underwent neck dissection only if the neck had to be entered to resect the primary tumor or if the primary tumor was T3 or T4 with a high probability of microscopic metastasis. RESULTS: Of the 20 necks that were histologically N-, 16 (80%) were clinically diagnosed as N- and 4 (20%) N+ versus 18 (90%) N- and 2 (10%) N+ diagnosed by CT scan. Of the 20 histologically N+ necks, 12 (60%) were clinically diagnosed as N+ and 8 (40%) N- versus 11 (55%) N+ and 9 (45%) N- diagnosed by CT scan. All lymph nodes diagnosed as N- by both clinical examination and CT scan were less than 1 cm in diameter. Overall, clinical examination of the neck was correct in 28 patients (70%) and the CT scan was correct in 29 patients (73%). Both clinical examination and CT scan were more accurate in diagnosis of N- necks. In 31 necks (78%), the CT and clinical examination were in agreement. Of these, 10 of 10 (100%) were correctly positive. Of the 21 in which both were negative, 14 were histologically N-, and 14 (67%) were correct. Overall, in those cases in which both CT and clinical examination were in agreement, the diagnosis was correct in 24 of 31 (77%). CONCLUSION: These results suggest that there is no significant difference in the accuracy of clinical examination versus CT scanning in detecting both positive and negative cervical nodes. When both CT and clinical examination agree, positive cervical nodes are almost always correctly diagnosed. However, one third of the negative cervical nodes were incorrectly diagnosed. Improved methods for detecting occult disease are still needed.

Carcinoma, Squamous Cell↗