Magnetic resonance imaging of the pediatric musculoskeletal system.
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Bone Neoplasms↗
Biomedical subjects
M D Cohen
Publications and source records attributed to M D Cohen.
Weight reduction in obese hypertensive patients.
This study tested the feasibility of a low-technology office-based approach to weight reduction in obese hypertensive patients. Family practice residents were randomly assigned to either an experimental or a control group. Physicians in the experimental group were instructed in methods of weight reduction, which they then passed on to their patients. Patients of experimental physicians were seen monthly, their diets were discussed, and improvements were suggested. The control group patients received their usual care. After six months the experimental patients had lost significantly more weight than the controls and had significantly reduced the number of antihypertensive drugs while maintaining blood pressure control. After 12 months there was no significant difference between the two groups with respect to weight loss, blood pressure, or number of antihypertensive drugs. Experimental and control patients who lost weight had visited their physicians more frequently than those who did not and had reduced the number of antihypertensive medications they were taking. This educationally oriented intervention trial is an example of the type of research that is practical to perform in a family practice center and is applicable in family physicians' offices.
Adult↗
Estimation of coronary flow reserve by intracoronary Doppler flow probes and digital angiography.
This prospective study investigated two different methods used clinically to estimate coronary flow reserve during cardiac catheterization. First, the relationship between simultaneous digital angiography and intracoronary Doppler velocity measurements was determined in 61 patients. The correlation coefficient for 233 simultaneous pairs of papaverine-induced flow reserve was 0.70 (Doppler = 0.41 digital + 0.93, P less than 0.0001). Repeated basal flow determinations showed little variability (Doppler: 2 +/- 5% (mean +/- 95% confidence intervals); digital: 3 +/- 10%). Repeated hyperemic flow estimates by the Doppler technique were more reproducible (10 +/- 2%) than those by the digital method (26 +/- 6%). Second, estimates of coronary flow reserve by side-mounted and end-mounted Doppler catheters were compared in vitro and in patients. In vitro measurement of blood velocity was linear for both catheter designs and was highly correlated with volume flow determined by electromagnetic flow meter (r = 0.99 side-mounted; r = 0.96 end-mounted). In patients (n = 20), average coronary flow reserve for the side-mounted Doppler crystal was 2.64 +/- 0.15 and for the end-mounted Doppler crystal was 2.40 +/- 0.14 (P less than 0.02). When flow reserve was determined twice for each catheter, there was greater variability in repeated measurements using the side-mounted Doppler crystal (21 +/- 10%, n = 14) than using the end-mounted Doppler crystal (12 +/- 4%, n = 32).(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
A blotting method for monitoring the formation of chemically induced DNA-protein complexes.
The formation and identification of DNA-protein crosslinks are usually detected by filter binding assays such as alkaline elution. We describe a modified blotting method to selectively identify DNA-protein complexes (DPCs) formed in vitro by either Cr3+ ion or formaldehyde. This protocol allows DPC formation in vitro to be assayed with various chemical agents, requires minimal usage of radioactivity, and is performed in a shorter time frame than that commonly used to resolve DPCs from free proteins and unbound DNA.
Actins↗
An assessment of the genotoxicity of vanadium.
The activities of vanadium oxide (V2O3), vanadyl sulfate (VOSO4) and ammonium metavanadate (NH4VO3) in inducing sister chromatid exchange (SCE) and chromosomal aberrations (CAb) were assayed in Chinese hamster ovary cells. The toxic concentrations (TC50) for these compounds were found to be 25, 23 and 16 micrograms elemental vanadium/ml, respectively. At does 1/50-1/4 TC50, vanadium compounds were able to induce significant increases (P less than 0.01) in the SCE frequency with or without the addition of rat hepatic S9 mix. These compounds also induced CAb in the cells at doses closely equivalent to the TC50.
Animals↗
Magnetic resonance differentiation of acute and chronic osteomyelitis in children.
A comparison has been made of the MRI findings of 17 studies in 16 patients with osteomyelitis: eight studies were performed in patients with acute osteomyelitis, six in chronic and three in healed osteomyelitis. Soft tissues, cortex and marrow were assessed in all patients. The best predictors of acute osteomyelitis were poorly defined soft tissue planes, absence of cortical thickening, and a poor interface between normal and diseased marrow. In contrast, chronic osteomyelitis was suggested by the presence of well-defined soft tissue abnormality, thickened cortex, and a relatively good interface between normal and diseased marrow. The appearance of osteomyelitis did not vary in different anatomic sites.
Acute Disease↗
The availability of fellowship training for foreign family physicians.
The authors surveyed the 49 U.S. fellowship programs in family medicine listed in the 1988 Fellowship Directory published by the Society of Teachers of Family Medicine. The past experience and future intentions of the 47 responding programs toward non-immigrant foreign family physicians coming to the United States to undergo fellowship training in academic family practice were studied. Only a minority of the programs (22%) had ever trained a foreign fellow, and of these only five of 11 were definitely able to do so in the future. Over half (52%) of the programs that had never trained a foreign fellow stated that they were not prepared to train a foreign physician. Although foreign family physicians are encouraged by the American Academy of Family Practice to come to the United States for fellowships, this study shows that it is extremely difficult for these physicians to find programs willing to act as host.
Directories as Topic↗
Effects of desipramine hydrochloride on peripheral sympathetic nerve activity.
Tricyclic antidepressants cause orthostatic hypotension and have antiarrhythmic effects that may be partially due to effects on the sympathetic nervous system. We studied the influence of intravenous desipramine hydrochloride on renal (n = 12) and lumbar (n = 5) nerve traffic and mean arterial pressure in alpha-chloralose-anesthetized rabbits with sinoaortic and vagal denervation. Desipramine administration resulted in dose-dependent inhibition of renal and lumbar nerve activity that was markedly reduced or abolished by yohimbine (0.5 mg/kg iv), an alpha 2-blocker that enters the brain rapidly. In contrast, administration of phentolamine (0.75 mg/kg iv), an alpha 1- and alpha 2-blocker with limited access to the brain, failed to alter the responses to desipramine. Because renal nerves are postganglionic and lumbar nerves are preganglionic, desipramine does not act via a ganglionic mechanism. Our results are best explained by an effect of desipramine on the sympathetic nervous system mediated via central alpha 2-receptors. This sympathoinhibitory effect of desipramine may contribute to its postural hypotensive effect and to its efficacy as an antiarrhythmic agent.
Adrenergic alpha-Antagonists↗
The Robert Wood Johnson Foundation Program on Chronic Mental Illness: an overview.
In 1985 the Robert Wood Johnson Foundation implemented the Program on Chronic Mental Illness, which provides grants and assistance to nine cities across the country in their efforts to improve services to persons with chronic mental illness. A basic premise of the program is that a central mental health authority is the cornerstone of improved systems of care. To be eligible for participation in the program, each city had to develop a service system incorporating a central authority and four other features: continuity of care, a full range of services, a housing plan, and new sources of financing. The authors describe how the cities were selected and how the program operates. They also provide a case example of the problems one city faced in establishing a central authority.
Chronic Disease↗
Cardiac arrhythmias during theophylline toxicity. A prospective continuous electrocardiographic study.
To examine the effects of theophylline toxicity on cardiac rhythm, patients underwent continuous ambulatory ECG recording during acute theophylline toxicity and recovery. The patients, who were recruited form inpatient wards, intensive care units, and emergency departments of a University Medical Center and a Veterans Administration Medical Center, had serum theophylline concentrations (STC) greater than 30 mg/L. There were 14 men and two women with a mean age of 66 years. Fourteen patients had COPD and developed toxicity following long-term theophylline overmedication. Two patients had asthma and ingested an intentional overdose. The STC at the onset of ECG recording ranged from 23 to 67 mg/L. The principal rhythm was sinus in 15 patients; one patient had atrial fibrillation. Sinus tachycardia (heart rate greater than 100/min) was common, and heart rate fell in proportion to STC as toxicity resolved. Supraventricular ectopic beats (SVEs) were noted in seven patients with multiple runs of SVE being present in four. One patient developed multifocal atrial tachycardia (MAT) during toxicity that resolved spontaneously. During the 11 +/- 8 hours of recording during toxicity (STC greater than 20 mg/L), 80 percent of patients had ventricular premature beats (VPBs), 44 percent had paired VPBs, and 25 percent had ventricular runs. One elderly patient with heart disease developed sustained ventricular tachycardia (VT) when STC = 66 mg/L. No other patient had ventricular ectopy that required intervention. During the 10 +/- 6 hours of recording during the "recovery phase" (STC less than 20 mg/L), all patients with VPBs continued to have ectopy; however, the number of VPBs declined significantly. A follow-up 24-hour ECG recording obtained one week after recovery from toxicity in the patient with sustained VT demonstrated marked reduction in the frequency and complexity of VPBs. Patients with frequent (greater than 10/h) or repetitive VPBs were older (p less than 0.05) than those without complex ectopy. There was a trend (p = 0.07) suggesting patients with underlying heart disease were at risk for having complex ventricular ectopy. We conclude that sinus tachycardia, SVE, and VPBs are common among patients with theophylline toxicity; however, sustained ventricular or supraventricular tachyarrhythmias that require antiarrhythmic therapy are uncommon.
Acute Disease↗
Polymyalgia rheumatica.
Polymyalgia rheumatica is a syndrome that occurs in the elderly and is characterized by pain and stiffness involving the neck, the shoulder girdle, and the hip girdle. The aching should be present for greater than one month. Polymyalgia rheumatica may be more common than reported. The etiology remains unknown. There is generally little found pathologically in this disease. The physical examination is often not impressive. Synovitis may be a main contributing factor to many of the symptoms seen in patients with polymyalgia rheumatica. Symptoms often do not correlate with physical findings. Polymyalgia rheumatica must be differentiated from many conditions since the diagnosis remains entirely clinical. Osteoarthritis, flu syndromes, inflammatory myopathies, fibromyalgia, and depression all have features that may mimic polymyalgia rheumatica. Malignancies and infections may also be difficult to separate from polymyalgia rheumatica. Polymyalgia rheumatica may also be extremely difficult to differentiate from seronegative rheumatoid arthritis in patients older than 50 years. Although some patients with polymyalgia rheumatica have underlying giant cell arteritis, the majority apparently do not. The distinction between polymyalgia rheumatica and giant cell arteritis cannot be made on the basis of laboratory studies and relies solely on clinical symptoms and physical findings. Although nonsteroidal antiinflammatory medications may control symptoms in patients with mild disease, most patients with polymyalgia rheumatica require low-dose corticosteroids. The tapering schedule for the corticosteroids is contingent upon the response of symptoms and laboratory parameters. Polymyalgia rheumatica usually follows a benign course with almost complete response to an adequate treatment program. Recently, there have been several studies suggesting that the course of polymyalgia rheumatica may not be as short and simple as once proposed. Nevertheless, many patients may be completely weaned from corticosteroids. Other agents have been used in this disease, but for the most part their use remains somewhat controversial. Patients must be monitored carefully. Most patients do well, and treatment is effective.
Aged↗
Choosing contrast media for pediatric gastrointestinal examinations.
The availability of the new low osmolality contrast agents during the last few years has necessitated a reconsideration of which is the most appropriate contrast agent to utilize in the gastrointestinal (GI) tract. There are some clinical situations in which these new agents have become the contrast media of choice (e.g., evaluation of suspected necrotizing enterocolitis, evaluation of suspected bowel perforation). There are many other clinical situations in which one needs to weigh the potential benefits of the new agents against significantly increased costs. This report reviews in detail the available contrast agents for studying the GI tract and outlines the advantages and disadvantages of each agent. The new agents are compared with existing agents such as barium and the hypertonic water soluble agents (e.g., gastrografin, hypaque, conray, etc.). Guidelines for the use of each agent are presented.
Contrast Media↗
Abdominal magnetic resonance imaging.
A review of the first five years of experience with pediatric abdominal Magnetic Resonance Imaging (MR) is presented. The abdomen is examined organ by organ with description of normal anatomy and pathological processes. Practical clinical uses of MR are indicated. There is a brief review of motion artifact suppression techniques.
Abdomen↗
Decreased resistance to Listeria monocytogenes in mice following vanadate exposure: effects upon the function of macrophages.
We have previously demonstrated that ammonium metavanadate has a broad immunomodulating effect in mice after subchronic exposure. Because host resistance to pathogenic Listeria monocytogenes and in vitro phagocytic activity of harvested peritoneal macrophages (PEM) were strongly affected by vanadate treatment, we investigated the effect of vanadate on the functional role of resident PEM in active listeriosis in the mouse. Vanadium treatment results in altered patterns of clearance of the organism from the peritoneal cavity, liver and spleen. The total in vitro phagocytic uptake of Listeria by PEM was consistently decreased as a function of infection period. Similarly, intracellular killing of Listeria was decreased although the PEM from the vanadate-treated and control mice were more bacteriostatic than bactericidal. Population distributions of Listeria within infected PEM were not affected by host pretreatment with vanadate. Vanadate exposure interferes with both the uptake and ultimate intraphagolysosomal killing of Listeria. These results were expected in light of our previous studies of the effects of vanadate on PEM superoxide production, and hexose monophosphate shunt and glutathione redox cycle activity. The results provide additional information for the development of a mechanism to explain why workers exposed to vanadium-containing dusts have increased susceptibility to bacterial respiratory diseases.
Animals↗
Digital imaging of the newborn chest.
The study reports initial experience on utilising an area plate digital imaging system to obtain portable radiographic images on newborn infants. Initial results suggest that the system is a practical alternative to conventional portable radiography with potential advantages of decreasing the number of retake films and also of decreasing radiation dose.
Algorithms↗
Tc-99m MDP uptake in a case of hepatoblastoma.
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Carcinoma, Hepatocellular↗
Pericardial repair of endocardial defect following regional endocardial resection for ventricular tachycardia.
Regional endocardial resection is the accepted surgical treatment for sustained monomorphic ventricular tachycardia. In patients requiring extensive endocardial resection, or with large aneurysms involving the interventricular septum, the resulting defect may result in weakened myocardium and, ultimately, ventricular septal defect or ventricular rupture. A new approach for repair of the resulting defect is proposed using an autogenous pericardial patch sutured to normal endocardium and included in the aneurysm repair. This technique was performed in six patients undergoing surgery for drug refractory ventricular tachycardia. All patients had large anterior left ventricular aneurysms with endocardial scar extending onto the septum. The large endocardial defect left after endocardial resection and aneurysmectomy was repaired with a pericardial patch. No intraoperative complications (e.g., suture line bleeding) were observed as a result of this technique. All patients are alive, and five of the six patients no longer have inducible ventricular tachycardia. An improvement in congestive heart failure symptoms at 1-9 months of follow-up was noted following surgery. We conclude that the pericardium can be safely used to cover endocardial defects resulting from regional endocardial resection for sustained ventricular tachycardia.
Animals↗