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Biomedical subjects

M D Cohen

Publications and source records attributed to M D Cohen.

At least 163 records · Page 9Linked to original sources

Neurosonographic identification of ventricular asymmetry in premature infants.

Routine head ultrasound scans have been performed on 185 consecutive infants weighing under 1500 g at birth. In 40 of these infants a significant difference in the size of the lateral ventricles was observed on one or more occasions. In 38 of these infants the left ventricle was larger than the right. The aetiology of this ventricular asymmetry is unknown. It is not believed to be due to germinal matrix or ventricular haemorrhage, hydrocephalus or the position of the infant at the time of scanning.

Cerebral Hemorrhage↗

Preoperative evaluation of pediatric abdominal tumor volumes by computerized tomography.

The volumes of two neuroblastomas and two Wilms' tumor masses were calculated by computerized tomography (CT) within 48 hours of surgical removal of the tumor. True volumes of the tumor masses were obtained by volume displacement. CT was very accurate in predicting volume with an error ranging from 1.5% to 7.5%. This accurate method of evaluating tumor volume will allow precise monitoring of the response of nonoperable tumors to chemotherapy and radiotherapy.

Abdominal Neoplasms↗

Bowel perforation in the newborn: diagnosis with metrizamide.

Although the diagnosis of bowel perforation is frequently straightforward, it may be difficult in the neonate. Clinical signs may be limited to abdominal distension. If the patient is on assisted ventilation, pneumoperitoneum may be due to air tracking down from the chest rather than perforation. The authors report 6 cases of bowel perforation in infants in whom the diagnosis could not readily be made from the clinical findings and plain radiographs but was apparent when oral metrizamide was employed. This suggests that metrizamide can be a valuable adjunct in some cases of neonatal bowel perforation.

Diagnosis, Differential↗

Magnetic resonance imaging of bone marrow disease in children.

Seven children underwent magnetic resonance imaging (MRI) of the bone marrow: results showed that it is technically feasible to obtain good MR images of marrow in children. MR has detected abnormality in the bone marrow of a child who had metastatic neuroblastoma. The extent of abnormality in the femur correlated well with findings of a bone marrow isotope scan. In one child who had idiopathic aplastic anemia, diseased marrow could not be distinguished from normal marrow on MR images. MRI identified abnormality of the marrow in osteogenic sarcoma, and demonstrated change in response to chemotherapy. It displayed marrow spread of tumor as well as CT. MRI showed marrow abnormality in four children who had leukemia.

Anemia, Aplastic↗

Evaluation of the gasless abdomen in the newborn and young infant with metrizamide.

The finding of a gasless abdomen on the abdominal radiograph of an infant over 12 hr old is usually abnormal and may reflect a serious pathologic disorder. Accurate diagnosis is important to plan appropriate therapy. A careful review of the clinical history and the plain chest and abdominal radiographs will often permit an accurate diagnosis to be made. In cases where the diagnosis remains in doubt, contrast studies of the bowel with metrizamide have proved helpful. This report presents six infants with gasless abdomens of unknown cause. In each case, a metrizamide contrast study of the bowel was helpful in providing an accurate diagnosis.

Child, Preschool↗

Metrizamide evaluation of the esophagus in infants.

Barium and conventional hypertonic water-soluble contrast media (e.g., Gastrografin) are not ideal contrast agents in the evaluation of the esophagus when leakage into the mediastinum or aspiration into the lung is possible. Metrizamide (Amipaque) is water-soluble and can be well visualized in isotonic solution. Three cases are presented where metrizamide was used successfully in the evaluation of suspected esophageal perforation or tracheoesophageal fistula.

Esophageal Perforation↗

Magnetic resonance imaging of neuroblastoma with a 0.15-T magnet.

Magnetic resonance imaging (MRI) in nine children with neuroblastoma showed that MRI can effectively demonstrate primary and metastatic disease and aid in predicting tumor resectability. MRI can show changes in tumor size and intensity in response to chemotherapy or radiation therapy. Neuroblastomas have an image intensity much lower than that of liver and muscle on inversion-recovery scans. On spin-echo 500/30 scans, the tumors have a greater intensity than muscle and a similar or slightly greater intensity than liver. On spin-echo 1000/60 scans, they are always of greater intensity than liver or muscle. At this stage, the overall accuracy of MRI as compared with other imaging methods is not known.

Adrenal Gland Neoplasms↗

Calcification and uptake of Tc-99m diphosphonates in neuroblastomas: concise communication.

Sixty-six percent of 54 patients with neuroblastoma demonstrated uptake of bone-seeking radioagents by the primary tumor. This is a higher incidence than previously reported. Uptake was slightly more common in abdominal than thoracic tumors. There was a significant correlation between the size of the tumor and tracer uptake. Calcification was demonstrated in the primary tumor in almost 90% of the 54 patients. This is a much higher incidence of calcification than previously reported. Microscopy shows that the calcification is not always due to tumor necrosis; it also occurs in areas of viable tumor cells. Tracer uptake is believed to be related to calcium metabolism. The rate of metabolic activity rather than the total amount of calcium present within the tumor may be the most important factor in determining the amount of uptake. No significant relationship was found between tracer uptake and tumor stage or homovanillic acid and vanillylmandelic acid metabolic activity.

Abdominal Neoplasms↗

Cauda equina syndrome secondary to long-standing ankylosing spondylitis.

Fourteen patients with cauda equina syndrome secondary to long-standing ankylosing spondylitis are described. The roughly symmetrical neurological deficits were very slowly progressive and began long after the onset of the spondylitis, usually well after the rheumatological symptoms had stopped. Eventually every patient had cutaneous sensory loss in the fifth lumbar and sacral dermatomes. All patients developed urinary sphincter disturbances of a lower motor neuron type. There was prominent loss of rectal sphincter tone, and all but 2 patients had bowel complaints, including incontinence and severe constipation. Seven patients had mild to moderate weakness in the lumbosacral myotomes. Seven patients had pain in the rectum or lower limbs. Electromyographic abnormalities were consistent with multiple lumbosacral radiculopathies. Myelography and computed tomographic scanning of the lumbosacral spine showed characteristic enlargement of the caudal sac and dorsal arachnoid diverticula that had eroded the laminae and spinous processes. Recognition of this syndrome, coupled with computed tomographic scanning of the lower spinal canal, allows one to omit myelography, a procedure that is difficult because of the associated spine abnormalities. Surgical intervention should be avoided.

Adolescent↗

Elevation of creatine kinase in amyotrophic lateral sclerosis. Potential confusion with polymyositis.

Serum creatine kinase (CK) levels were recorded in 100 patients with amyotrophic lateral sclerosis (ALS). CK concentrations were elevated in 43% of the patients, with a mean level of 240 U/liter and a range of 59-1,327 U/liter (male normal less than 95 U/liter, female normal less than 59 U/liter). All patients with elevated CK had muscle weakness. Seven patients were initially misdiagnosed as having polymyositis and given high dose corticosteroids without clinical benefit, prior to the diagnosis of ALS. Such diagnostic confusion can be avoided by an awareness that CK levels cannot be used to reliably differentiate between ALS and primary muscle disease such as polymyositis.

Adolescent↗

Immunohistologic and cytochemical studies of temporal arteritis.

Arteritic lesions from 14 patients with temporal arteritis were studied by cytochemical and immunohistochemical methods to identify the nature of the inflammatory cell infiltrate and to demonstrate immunoglobulin deposition. The infiltrating cells typically seen were histiocytes, giant cells, monocytes, and lymphocytes. The lymphocytes were mainly T cells and the majority of them were of the helper/inducer (Leu-3a) T cell subset, as indicated by monoclonal antibody reactivity. Immunoglobulin deposits on the internal elastica were identified in only 6 patients and neutrophils were either very sparse or absent. These findings are consistent with the hypothesis that cell-mediated immunity may be important in the pathogenesis of temporal arteritis.

Acid Phosphatase↗

Osteoid osteoma: 95 cases and a review of the literature.

Osteoid osteoma is a benign bone tumor occurring primarily in patients under the age of 30 yr. Bone pain at night and relief by aspirin or other nonsteroidal antiinflammatory agents is a common symptom complex. The proximal femur and spine are frequent sites of involvement, but almost any bone can be involved. If plain roentgenograms do not demonstrate the lesion, tomography or a bone scan may be helpful. Complete surgical excision is the therapy of choice with a low recurrence rate. Osteoid osteoma may present initially with symptoms suggestive of inflammatory arthritis, degenerative joint disease, neoplasm, or infection. This lesion can therefore be a difficult diagnostic problem, especially if routine roentgenograms are normal. A high index of suspicion is necessary to make the diagnosis.

Adolescent↗

A new look at the neonatal bowel-contrast studies with metrizamide (Amipaque).

Metrizamide is the first water-soluble radiographic contrast agent which, because it is nonionic, can be used in isotonic solution and gives good visualization of the desired body structure. Its only major disadvantage is that it is very expensive. Metrizamide can be used to study the neonatal bowel in clinical situations where all the other existing contrast agents are contraindicated. The results of 55 metrizamide studies of the bowel in infants are reviewed. In necrotizing enterocolitis metrizamide aids in confirming or rejecting the diagnosis, identifying patients for surgery, and in evaluating the response to surgery. Metrizamide can identify the etiology in unusual cases of bowel obstruction. Metrizamide correctly identified a thoracic origin of free peritoneal air in four cases and a bowel origin in two cases. It identified bowel perforation in two patients in the absence of pneumoperitoneum. In six patients, the metrizamide study identified the cause for a gasless abdomen. It is concluded that metrizamide has a valuable role to play in evaluating a variety of neonatal bowel disorders.

Drug Evaluation↗

The role of computerized tomography in the diagnosis and management of patients with bilateral Wilms tumor.

We report 2 cases of bilateral Wilms tumor. In both cases computerized tomography provided accurate data for the diagnosis of bilateral tumors and predicted surgical resectability, without nephrectomy, of the smaller tumor. In 1 patient computerized tomography demonstrated tumor growth while on chemotherapy and radiotherapy. The role of angiography in the management of these patients is discussed.

Combined Modality Therapy↗

The diagnostic dilemma of the posterior mediastinal thymus: CT manifestations.

Extension of the normal thymus into the posterior mediastinum is rare. The CT appearance of this anomaly in an infant is presented. A mass of soft-tissue density extended from the anterior mediastinum to the posterior chest wall. The absence of any tissue-cleavage plane in the lesion and a smooth continuous lateral margin are signs of posterior extension of the thymus, and they help to distinguish this from a normal anterior thymus being present with a posterior tumor.

Diagnosis, Differential↗