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Biomedical subjects

M D Cohen

Publications and source records attributed to M D Cohen.

At least 37 records · Page 2Linked to original sources
PubMed1998

Effect of breathing on the detection of in vivo simulated pulmonary nodules by spiral CT.

OBJECTIVE: To determine the effect of breathing on the detection of small dense pulmonary nodules of threshold conspicuity by spiral computed tomography (SCT). MATERIALS AND METHODS: Forty pulmonary nodules of high density were created by endobronchial deployment of 2 and 4mm diameter beads in the peripheral airways of five anaesthetized dogs. SCT was performed during induced breath-hold and quiet breathing, using 5 mm collimation, pitch 2 and reconstruction of contiguous 5 mm slices. Scans were reviewed by six radiologists. Detection rates were measured as the number of nodules seen by at least one reader. The data was modelled using ordinal logistic regression for repeated measures, and the Wald Chi-square statistic used to test if there was a breath-hold vs. breathing effect on reader confidence level. RESULTS: There was no difference in detection rates for breath-hold vs. breathing SCT (28 vs. 25, respectively; P=0.48). This was also true when only the 2 mm nodules (n=24) were considered (12 vs. 11, respectively; P=0.77). Reader confidence level was significantly higher for breath-hold vs. breathing SCT (Wald Chi-square statistic with 6 degrees of freedom=19.0; P=0.0041). CONCLUSION: SCT can be performed during quiet breathing without a significant reduction the overall detection rate for small dense pulmonary nodules, though reader diagnostic confidence level is reduced.

Animals↗
PubMed1998

Structural and functional reconstruction after resection of aneurysmal bone cyst of the fifth metatarsal: a case study.

We report a case of a primary benign bone tumor (aneurysmal bone cyst [ABC]) involving the distal portion of the fifth metatarsal, identified in an adolescent. The tumor, histologically identified as an ABC with reparative giant cell reaction, became symptomatic. Treatment included resection, followed by reconstruction of the fifth metatarsal using grafts of autologous bone with preservation of function in the metatarsophalangeal joint. The basis for selecting this form of treatment is discussed, as well as the natural history of ABC and giant cell reparative granuloma. Restoration of form and function is illustrated by this case study with a 23-month follow-up.

Adult↗
PubMed1998

Maximum intensity projection images in the detection of simulated pulmonary nodules by spiral CT.

This study was undertaken to investigate the use of maximum intensity projection (MIP) images in the detection of pulmonary nodules by spiral CT (SCT). 40 pulmonary nodules of high density were created by endobronchial deployment of 2 and 4 mm beads in the peripheral airways of five anesthetized dogs. Standard SCT was performed with 5 mm collimation, pitch 2 and reconstruction of contiguous slices. MIP images were generated from overlapped slabs of seven consecutive 3 mm slices, reconstructed at 2 mm intervals and acquired at pitch 2. Scans were reviewed by six radiologists. The data were modelled using ordinal logistic regression for repeated measures, and the Wald chi 2 statistic used to test if there was a difference in nodule detection and reader confidence level between the two techniques. MIP imaging increased the odds of nodule detection by 2.18 (p = 0.0002). Reader confidence level for nodule detection was significantly higher with MIP images (p < 0.00001). MIP images improve the detection rate for small high density pulmonary nodules and increase reader confidence level, when compared with standard SCT.

Animals↗
PubMed1998

Making sense of musculoskeletal disorders.

Evaluating musculoskeletal disorders can be challenging and time-consuming. Grouping the information from the history and physical examination into broad categories, inflammatory vs. non-inflammatory and local vs. systemic, serves as a general approach.

Diagnosis, Differential↗
PubMed1998

Hyaluronic acid treatment (viscosupplementation) for OA of the knee.

Viscosupplementation may be useful in the treatment of OA of the knee when other medical forms of therapy are contraindicated, toxic, or have failed. It may have a role in managing the patient with moderate to severe OA of the knee before considering total knee arthroplasty (Table 2). Viscosupplementation or medical treatment does not replace the need for thigh muscle strengthening or for overweight patients to lose weight. Whether or not efficacy will demand or warrant earlier or repeated use of hyaluronic acid-like products remains to be seen.

Humans↗
PubMed1997

Effects of vanadium upon polyl:C-induced responses in rat lung and alveolar macrophages.

Hosts exposed to vanadium (V) display a subsequent decrease in their resistance to infectious microorganisms. Our earlier studies with rats inhaling occupationally relevant levels of V (as, ammonium metavanadate, NH4VO3) indicated that several nascent/inducible functions of pulmonary macrophages (PAM) were reduced. In the present study, V-exposed rats were examined to determine whether some of the same effects might also occur in situ. Rats were exposed nose-only to air or 2 mg V/m3 (as NH4VO3) for 8 h/d for 4 d, followed, 24 h later, by intratracheal (it) instillation of polyinosinic:polycytidilic acid (polyl:C) or saline. Analysis of lavaged lung cells/fluids after polyl:C instillation indicated that total lavageable cell/neutrophil numbers and protein levels, while significantly elevated in both exposure groups (as well as in saline-treated V-exposed rats), were always greater in V-exposed hosts. Exposure to V also affected the inducible production of interleukin 6 (IL-6) and interferon gamma (IFN gamma), but apparently not that of tumor necrosis factor-alpha (TNF alpha) or IL-1. Although polyl:C induced significant increases in lavage fluid IL-6 and IFN gamma levels in both exposure groups, levels were greater in V-exposed rats. If calculated with respect to total lavaged protein, however, V-exposed rats produced significantly less cytokine. Following polyl:C instillation, there were no marked exposure-related differences in basal or stimulated superoxide anion production by pooled lavaged cells or PAM specifically. With V-exposed rats, pooled cells recovered 24 h after saline instillation displayed reduced production (in both cases) compared to the air control cells; PAM-specific production was affected only after stimulation. In both exposure groups, polyl:C caused decreased superoxide production in recovered cells. Though less apparent with pooled cells, there was a time post polyl:C instillation-dependent decrease in stimulated PAM-specific superoxide production; this effect was greater in PAM from V-exposed rats than in PAM from air controls. Phagocytic activity of PAM from rats in both exposure groups was significantly increased by polyl:C instillation, although total activity in cells obtained from V-exposed rats was always significantly lower compared to air control cells. Our results indicate that short-term, repeated inhalation of occupationally relevant levels of V by rats modulates pulmonary immunocompetence. Modified cytokine production and PAM functionality in response to biological response modifiers (such as lipopolysaccharide, IFN gamma, or polyl:C) may be, at least in part, responsible for the increases in bronchopulmonary disease in humans occupationally exposed to V.

Administration, Inhalation↗
PubMed1997

Combined accelerated tissue-plasminogen activator and platelet glycoprotein IIb/IIIa integrin receptor blockade with Integrilin in acute myocardial infarction. Results of a randomized, placebo-controlled, dose-ranging trial. IMPACT-AMI Investigators.

BACKGROUND: Platelet activation and aggregation may be key components of thrombolytic failure to restore and maintain perfusion in acute myocardial infarction. We performed a placebo-controlled, dose-ranging trial of Integrilin, a potent inhibitor of platelet aggregation, with heparin, aspirin, and accelerated alteplase. METHODS AND RESULTS: We assigned 132 patients in a 2:1 ratio to receive a bolus and continuous infusion of one of six Integrilin doses or placebo. Another 48 patients were randomized in a 3:1, double-blind fashion to receive the highest Integrilin dose from the first phase or placebo. All patients received accelerated alteplase, aspirin, and intravenous heparin infusion; all but two groups also received an intravenous heparin bolus. The highest Integrilin dose group from the nonrandomized phase and the randomized patients were pooled for analysis and compared with placebo-treated patients. The primary end point was Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow at 90-minute angiography. Secondary end points were time to ST-segment recovery, an in-hospital composite (death, reinfarction, stroke, revascularization procedures, new heart failure, or pulmonary edema), and bleeding variables. The highest Integrilin dose groups had more complete reperfusion (TIMI grade 3 flow, 66% versus 39% for placebo-treated patients; P = .006) and a shorter median time to ST-segment recovery (65 versus 116 minutes for placebo; P = .05). The groups had similar rates of the composite end point (43% versus 42% for placebo-treated patients) and severe bleeding (4% versus 5%, respectively). CONCLUSIONS: The incidence and speed of reperfusion can be enhanced when a potent inhibitor of the glycoprotein IIb/IIIa integrin receptor, such as Integrilin, is combined with accelerated alteplase, aspirin, and intravenous heparin.

Adult↗
PubMed1997

An unusual case of carcinoma polyarthritis with associated vasculitis.

This report describes a patient who presented with an unusual polyarthritis syndrome. After extensive evaluation, squamous cell carcinoma of the lung was diagnosed. During the course of the illness, the patient developed vasculitic features and "rheumatoid-like" nodules. Two months after the administration of combined-modality therapy for stage IIIA non-small cell lung carcinoma, the signs and symptoms of polyarthritis and vasculitis had disappeared completely. Ten months later, the patient remains in clinical remission. This is the first published report of simultaneous vasculitic and polyarticular manifestations in a patient with carcinoma polyarthritis.

Anti-Inflammatory Agents↗
PubMed1997

Detection of pulmonary metastases with pathological correlation: effect of breathing on the accuracy of spiral CT.

BACKGROUND: CT of the chest for suspected pulmonary metastases in adults is generally performed using a breath-hold technique. The results may not be applicable to young children in whom breath-holding may be impossible. OBJECTIVE: Determine the effect of breathing on the accuracy of pulmonary metastasis detection by spiral CT (SCT). MATERIALS AND METHODS: Prior to euthanasia four anesthetized dogs with metastatic osteosarcoma underwent SCT with a collimation of 5 mm and a pitch of 2, during both induced breath-hold and normal quiet breathing. Images were reconstructed as contiguous 5-mm slices. Macroscopically evident metastases were noted at postmortem. Hard-copy SCT images were reviewed by ten radiologists, each of whom circled all suspected metastases. SCT images were compared with postmortem results to determine true and false positives. RESULTS: The pathologist identified 132 macroscopically evident pulmonary metastases. For metastasis detection, there was no significant difference between breath-hold SCT and breathing SCT. CONCLUSION: In our animal model, SCT can be performed during normal resting breathing without significant loss of accuracy in the detection of pulmonary metastases.

Animals↗
PubMed1997

Wilms tumor imaging: patient costs and protocol compliance.

PURPOSE: To evaluate the patient costs for imaging and compliance with imaging protocols in pediatric patients in the National Wilms Tumor Study (NWTS) IV. MATERIALS AND METHODS: The medical and imaging records of 60 patients (28 male, 32 female; aged 3 days to 12.6 years) in NWTS IV were reviewed. Initial imaging and follow-up imaging were evaluated separately. Three levels of follow-up compliance were evaluated. RESULTS: The total patient cost for imaging was $442,180: $94,212 for initial and $347,968 for follow-up studies. Many areas of potential cost savings were identified. Protocol compliance was variable. Seventy-five percent of patients underwent studies in full compliance with the initial protocol requirements. For follow-up, compliance was 0%-80% for different studies at different compliance levels. For no study was compliance 100%. CONCLUSION: Imaging costs in pediatric patients with Wilms tumor are substantial. Protocol compliance was not optimal.

Child↗
PubMed1997

TGF-beta 1 modulates human airway smooth-muscle cell proliferation induced by mitogens.

Asthma is a disease of airway inflammation and bronchoconstriction that results in airway smooth-muscle cell hypertrophy and hyperplasia. The underlying mechanisms that induce myocyte proliferation remain unknown. Evidence suggests that cytokines such as transforming growth factor (TGF)-beta 1 may play a role in modulating this process. In this study, we examined the effects of TGF-beta 1 on human airway smooth-muscle (HASM) cell proliferation. We found that treatment of HASM cells with TGF-beta 1 inhibited epidermal growth factor (EGF)- and thrombin-induced DNA synthesis. This inhibition was both dose and time dependent. We then investigated whether these effects are mediated through activation of mitogen-activated protein kinase (MAP kinase), an enzyme that is thought to play a central role in the regulation of cell proliferation. We found that MAP kinase activation induced by EGF was not modulated by TGF-beta 1, despite TGF-beta 1 inhibiting EGF-induced HASM cell growth. These data suggest that TGF-beta 1 inhibits mitogen-induced HASM cell proliferation, but does so downstream from MAP kinase activation, or via a parallel pathway that is independent of MAP kinase activation.

Calcium-Calmodulin-Dependent Protein Kinases↗
PubMed1997

Posterior vertebral body erosion by arachnoid diverticula in cauda equina syndrome: an unusual manifestation of ankylosing spondylitis.

Cauda equina syndrome is an uncommon complication of longstanding ankylosing spondylitis. It is associated with dorsal arachnoid diverticula, which may erode the lamina and spinous processes of the bony lumbosacral spine. We describe a patient who developed cauda equina syndrome associated with the unusual finding of erosion of the posterior aspect of 2 vertebral bodies by arachnoid diverticula. This was clearly revealed by magnetic resonance imaging of the spine.

Aged↗
PubMed1997

Imaging modalities in pediatric oncology.

Many imaging modalities are available for the diagnosis, follow-up, and sometimes treatment of pediatric oncology diseases. The advantages and disadvantages, indications and contraindications, techniques, and patient preparations of the most commonly used modalities are discussed in this article. The role of sedation and the most widely used drugs are also discussed.

Child↗
PubMed1996

Effects of ozone upon macrophage-interferon interactions.

Lung cell populations may be directly exposed to environmental airbone toxicants such as ozone (O3). Since pulmonary macrophages (M phi) play a pivotal role in host pulmonary immunocompetence, their function in this regard may be compromised by pollutant exposure thereby giving rise to an increased incidence of pulmonary disease. The current in vitro study was designed to provide some insight into possible mechanisms by which O3 induces decreased host pulmonary resistance against microbial pathogens. Specifically, this study investigated the impact of an acute O3 exposure upon the ability of a cultured mouse M phi cell line (WEHI-3) to interact with, and respond to, the major M phi-activating cytokine, interferon-gamma (IFN gamma). The results of this study indicate that WEHI-3 exposure to 1 ppm O3 for 4 h reduced both the binding of, and responsivity to, IFN gamma. Among the functional parameters affected by this inability to properly bind/respond to IFN gamma were: reactive oxygen intermediate production, phagocytic activity, and cellular calcium ion elevation; IFN gamma-enhanced expression of surface histocompatibility antigens was unaffected by O3 exposure. The reduced activity of any one of these critical M phi functions could provide a basis for previously-documented increases in microbial pathogen survival in the lungs, and overall compromise of host health following O3 exposure.

Animals↗
PubMed1996

Public managed care: the role of the consultant.

Consultants will be increasingly important as public systems retool to fund and monitor managed behavioral health care services. Medicaid agencies, heretofore limited primarily to paying claims, must now develop expertise in RFP preparation and managing contracts.

Clinical Competence↗