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Biomedical subjects

B Kaufman

Publications and source records attributed to B Kaufman.

At least 109 records · Page 6Linked to original sources
PubMed1984

Effects of deglycosylation on the architecture of ovine submaxillary mucin glycoprotein.

The structural features of native and deglycosylated ovine submaxillary mucin (OSM) were determined by electron microscopy of platinum unidirectionally shadowed preparations and by ultracentrifugation. Thin filamentous molecules, of which 90% were 100-230 nm in length with estimated diameters of 1.0-1.4 nm, were observed with dilute samples of OSM in high ionic strength solvents (5-30 micrograms/ml in 0.8 M NaCl or NH4Ac). Ultracentrifugation studies indicated that these filamentous structures were monomers and/or dimers. At higher mucin concentrations or in lower ionic strength solvents, OSM molecules were oligomers that appeared as long rope-like strands. Removal of sialic acid residues by incubation with Clostridium perfringens neuraminidase yielded filamentous structures similar to those observed with OSM and some smaller less extended structures. Subsequent removal of the GalNAc residues of asialo-OSM with C. perfringens alpha-N-acetylgalactosaminidase resulted in a dramatic change in appearance, from an extended filament to a globular form. The frictional ratios of OSM and deglycosylated OSM were consistent with the marked structural differences of these molecules. Native OSM had a frictional ratio of 3.09, comparable to that of highly asymmetric tropomyosin (3.22); deglycosylated OSM had a frictional ratio of 1.11, comparable to that of globular ovalbumin (1.08).

Amino Acids↗
PubMed1984

Postoperative use of epidurally administered morphine in children and adolescents.

Epidurally administered narcotics are increasingly used to provide relief of pain in adults after major surgical procedures. This report describes the use of epidurally administered morphine for postoperative analgesia in nine pediatric patients after 15 major surgical procedures. The mean dose of morphine was 0.12 +/- 0.03 mg/kg of body weight, and the mean duration of analgesia per dose was 10.8 +/- 4.0 hours. Catheters remained in place for a mean duration of 50.3 +/- 16.0 hours. Increasing the dose of morphine to more than 0.1 mg/kg did not prolong the duration of analgesia but it did increase the frequency of side effects. No complications from placement of the catheter and no serious side effects were encountered. The postoperative requirements for narcotics were significantly less in the patients who received morphine epidurally than in those who received narcotics parenterally. Epidurally administered morphine can provide reliable postoperative analgesia in pediatric patients. The potential benefits include improved quality of pain relief at low total requirements, improved pulmonary function, and early ambulation.

Adolescent↗
PubMed1984

MR imaging of the skull base.

Fifty-four patients with abnormalities primarily involving the base of the skull were evaluated by magnetic resonance (MR) imaging. The results were compared with information obtained by other radiologic studies, primarily X-ray CT. On MR imaging, better anatomic definition of soft tissues in the deep compartments of the nasopharynx was achieved through the high level of tissue contrast discrimination and lack of bone artifacts. The parapharyngeal fat plane, separating pterygoid from pharyngeal musculatures, was consistently demonstrated. However, the inability of MR to image compact bone proved to be a major drawback where bony detail was required. In general, MR imaging demonstrated 100% sensitivity to abnormalities involving the posterior compartment (clivus and craniovertebral junction) and was least valuable in the evaluation of the anterior compartment (orbits, cribiform plate, and sinuses.

Adolescent↗
PubMed1984

Head trauma evaluated by magnetic resonance and computed tomography: a comparison.

Magnetic resonance (MR) images and computed tomograms of 25 patients with head trauma were compared. MR proved to be superior in many ways for demonstrating extracerebral as well as intracerebral traumatic lesions. Isodense subdural hematomas, which present a diagnostic dilemma on CT images were clearly seen on MR, regardless of their varying CT densities. In a case of epidural hematoma, the dura mater was shown directly as nearly devoid of signal on MR. Direct coronal images provided excellent visualization of extracerebral collections along the peritentorial space and subtemporal area. In a patient with intracerebral hematoma, CT failed to demonstrate residual parenchymal changes in a 3-month follow-up study, but MR clearly depicted the abnormalities. The superiority of MR over CT was also well illustrated in a patient with post-traumatic osteomyelitis of the calvarium.

Adolescent↗
PubMed1984

Magnetic resonance imaging in the evaluation of the brainstem.

Magnetic resonance (MR) images of the brainstem region from 100 normal or asymptomatic individuals were reviewed in addition to those of 17 patients with intra-axial brainstem lesions and 15 patients with extra-axial masses around the brainstem. MR was able to demonstrate consistently the normal anatomy of the brainstem and adjacent cisterns, though the distinction between gray and white matter was seldom possible with the present technology. Masses in and around the brainstem were all accurately identified on MR and its sensitivity was superior to that of x-ray computed tomography (CT). These study results show that despite its technical limitations, MR is presently the examination of choice for the evaluation of brainstem abnormalities and eventually it will undoubtedly replace metrizamide CT cisternography.

Adolescent↗
PubMed1984

Magnetic resonance imaging of the orbit: a preliminary experience.

Eleven patients with various space-occupying lesions in the orbit were examined, using a 0.3-tesla superconducting magnet to assess the capabilities and limitations of magnetic resonance (MR) imaging in the investigation of orbital lesions. Although the images provided valuable anatomic data, the bright signal intensity of fat and the partial volume effects of large section thickness resulted in loss of resolution for small, low-signal-intensity structures. The limitations of MR imaging were also reaffirmed by the lack of visualization of calcifications and of the bony orbit. These preliminary results show that MR offers no advantage over x-ray computed tomography except for its lack of ionizing radiation. Further technical improvements are needed before MR imaging will be made useful in this area.

Adult↗
PubMed1984

Cervicomedullary junction tumor diagnosed by nuclear magnetic resonance scanning: case report.

A neurofibroma of the cervical medullary region was accurately delineated using nuclear magnetic resonance (NMR) scanning. The tumor and its compression of the spinal cord were so well visualized that evaluation by myelography and postmyelographic computed tomography (CT) was unnecessary. NMR scanning should be considered as a replacement for myelography with CT in the initial evaluation of cervicomedullary spinal cord tumors.

Adolescent↗
PubMed1984

Magnetic resonance imaging of the pituitary gland.

Magnetic resonance imaging (MRI), a nonionizing, biologically safe imaging technique, is bringing the desired goal of directly imaging the pituitary gland very close to reality. The exquisite anatomic demonstration of the gland and hypophyseal stalk and the perisellar structures and the usefulness of tissue characterizations (T1 and T2 values) firmly establish the role of MRI in imaging of pituitary gland abnormalities, with the potential of becoming the procedure of choice.

Adenoma↗
PubMed1984

RBC fragmentation and thymoma.

Thrombocytopenia and hemolytic anemia with fragmented RBCs were discovered in a 70-year-old woman with a large mediastinal mass. Investigation of the cause of the hematologic findings was negative. The mass was surgically excised and proved to be a thymoma of spindle cell type. The hemogram findings returned to normal within a month of surgery. We postulate the thymoma as the source of the RBC fragmentation and thrombocytopenia and explore the relationship between tumors and the hematologic findings.

Aged↗
PubMed1984

Extradural meningeal cyst. Case report and review of the literature.

Extradural meningeal cysts are rare spinal lesions. The clinical presentation is most often characterized by a slowly progressive spastic paraparesis, frequently associated with pain. Adequate drainage of the cyst with obliteration of the neck of the cyst or complete removal of the cyst can bring about a permanent resolution of the symptoms. The use of somatosensory cortical evoked responses also has an important role in the surgical management of this problem.

Child↗
PubMed1983

Surgical implications of Klippel-Trenaunay syndrome.

Between January 1956 and July 1981, 40 patients with Klippel-Trenaunay syndrome were seen at the Mayo Clinic. Twenty male and 20 female patients presented with the classic triad of soft tissue and bony hypertrophy of the extremity, hemangioma, and varicosity without evidence of functional arteriovenous fistulae. The lower extremity was involved in 38 patients (95%), the upper extremity in six patients (15%). In four of these cases (10%), both the upper and lower extremities were affected. The disease was unilateral in 34 patients (85%), bilateral in five cases (12.5%), and crossed-bilateral in one case (2.5%). Surgery was done in 13 patients (32.5%), nine of whom were operated on at the Mayo Clinic and four of whom had had previous surgery elsewhere. Excision and stripping of varices were performed in three patients; of these three, a deterioration of symptoms was observed in one, but the procedure was beneficial in the other two. Partial varicectomy was performed in four cases, while resection of the angioma was attempted in eight cases, with good results in three cases of small angiomas. Femoral and tibial epiphysiodesis stopped the overgrowth and produced an excellent result in one case. In four cases of epiphysiodesis at the foot level and two cases of derotational tibial osteotomy, moderate improvement was achieved. The indication for vascular or orthopedic surgery should be carefully considered in each patient who has this syndrome. One patient (2.5%) died of a severe form of the disease, but the relatively benign course is documented by the 21 patients (52.5%) who are free of complaints without any treatment or with elastic support only.

Adolescent↗
PubMed1983

NMR imaging of the spine.

The usefulness of nuclear magnetic resonance (NMR) images in the evaluation of spinal disorders below the craniocervical junction was studied. Six normal subjects and 41 patients with various spinal abnormalities were examined. NMR proved capable of demonstrating important normal and pathologic anatomic structures; it was useful in the evaluation of syringohydromyelia and cystic spinal cord tumors, and the bright signal intensity of lipoma was quite impressive. In the evaluation of herniated disk, NMR images offered a new perspective by visualizing abnormal degradation of the signal intensity of the nucleus pulposus itself. NMR images were least valuable in the evaluation of spondylosis and spinal stenosis. Although NMR imaging of the spine is still in a very early developmental stage, the absence of both ionizing radiation and risks associated with contrast material makes it especially attractive as a new diagnostic method. This limited experience with currently available equipment suggests that, with technical refinement, the efficacy of NMR of the spine will increase.

Adolescent↗
PubMed1983

Treatment of defects of the anterior abdominal wall in newborns.

Primary closure of an omphalocele or gastroschisis may cause respiratory compromise in the neonate. Some authors recommend primary closure of the defect with prolonged respiratory support because of dissatisfaction with staged visceral reduction and use of a Silastic pouch. Our experience with use of a Silastic pouch from 1975 to 1982 was reviewed. Twenty-three newborns with major defects of the abdominal wall (14 omphaloceles and 9 gastroschisis anomalies) were surgically treated, and only one death occurred. The mean birth weight of the infants was 2,927 g; nine of them were premature. Seven infants had major associated anomalies. The goal of the surgical procedure was closure of the abdominal wall without compromise of the cardiorespiratory status. During the operation, muscle relaxants were avoided and the infants breathed spontaneously. If progressive visceral reduction caused tachypnea (rate of more than 70/min) or hemodynamic instability, a Silastic pouch was constructed. Ten patients were treated with primary fascial closure, and 13 were treated with a Silastic prosthesis. The neonates with the prostheses required three to eight reductions, and the prostheses were in place for 4 to 22 days. No patient had wound dehiscence, wound infection, or an intestinal fistula. The one death occurred in an infant with trisomy 18 syndrome and multiple anomalies. Thus, the Silastic pouch was effective when the defect could not be closed primarily without respiratory compromise.

Critical Care↗
PubMed1983

Pseudorheumatoid subcutaneous nodules and the poststreptococcal state. A case report.

A 10-year-old girl with an acute illness fulfilling the Jones criteria for rheumatic fever is described. She had subcutaneous nodules, arthritis, an elevated ESR, and serologic evidence of a recent streptococcal infection. Her clinical course was benign and at ten weeks, the nodules disappeared, the joint pains had subsided, and the ESR was normal. Thus, there was little to support a diagnosis of rheumatic fever. We hypothesize that the patient had pseudorheumatoid subcutaneous nodules coincidental with poststreptococcal arthritis. A revision of the Jones criteria disallowing subcutaneous nodules as an independent major sign of rheumatic fever is proposed.

Arthritis, Infectious↗