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Biomedical subjects

K L Weiss

Publications and source records attributed to K L Weiss.

28 records · Page 2Linked to original sources

High-field MR surface-coil imaging of the hand and wrist. Part II. Pathologic correlations and clinical relevance.

High-resolution magnetic resonance (MR) images of the hands and wrists of 12 patients with a variety of suspected pathologic conditions were obtained at 1.5 T using a prototype surface coil. Lesions included ganglions, rheumatoid arthritis, carpal fractures, carpal tunnel syndrome, and arteriovenous malformations. In the selected cases studied, MR images provided potentially relevant information. Surgical, pathologic, and radiographic correlations were obtained. MR imaging affords delineation of soft-tissue structure that is unmatched by other imaging methods, including computed tomography. It is anticipated that MR imaging of the hand and wrist will afford sufficient valuable clinical information in certain conditions to justify its expense outside a research setting. Further clinical testing, however, is warranted.

Adult↗

Ankle: surface coil MR imaging at 1.5 T.

High-field surface coil magnetic resonance (MR) images were obtained of 12 ankles: two from healthy volunteers, seven from patients, and three from fresh cadavers. The cadaver ankles were sectioned in the coronal, sagittal, and axial planes for direct comparison with the MR images. Plain film confirmation of pathologic conditions was obtained in all patients, and five underwent arthroscopy or surgery, or both. MR imaging provided excellent delineation of ligaments and cartilaginous structures in all cases.

Ankle↗

Intracranial pressure changes during bilateral radical neck dissections.

The management of the contralateral neck in patients with head and neck cancer who have undergone a radical neck dissection (RND) is controversial. A number of these patients will require a second RND. Sacrifice of both internal jugular veins (IJV) has been felt to lead to increased intracranial pressure (ICP) with subsequent neurologic sequelae. From 1987 to 1991 four patients had staged bilateral RNDs at the West Virginia University. In these patients a subarachnoid bolt was placed to directly monitor ICP. Jugular bulb, mean arterial, pulmonary artery, and central venous pressures were monitored. Electroencephalographic (EEG) monitoring was also performed. All patients demonstrated elevations in ICP immediately on head rotation. Further marked elevations were noted immediately after IJV ligation with a maximum peak at 30 minutes. Pressure levels of greater than 40 mm Hg were observed in three of four patients. Systemic hypertension was observed in response to elevated ICP (Cushing's reflex). All patients studied recovered from surgery without significant sequelae. Within 24 hours the ICP had returned to normal in all patients. Three patients required intraoperative intervention to lower their ICP. We demonstrate that even in a staged second RND there are significant rises in ICP. These are to a level that suggests emergency medical intervention is required. We feel that when the second IJV is sacrificed an increase in ICP should be anticipated, monitored, and treated accordingly.

Aged↗

Platelet transfusion from donors mismatched for crossreactive HLA antigens.

Increments in platelet counts following the transfusion of platelets mismatched for crossreactive antigens were evaluated in 67 patients with broad alloimmunization to HLA antigens. The corrected increments following 100 HLA, A-matched and B1U- or B2U-matched transfusions were compared with the increments following 307 B1X- or B2X-matched transfusions. HLA-A3 platelets were tolerated poorly by A1 and A11 recipients, as were A1 and A11 by A3 recipients, B17 and BW21 by recipients in the B7 crossreactive group, B5 by B15 and B17 recipients, and B27 by recipients in the B5 crossreactive group. B12 and BW21, and B8 and B14 platelets were not tolerated bidirectionally. Antigens associated with good increments included A28 in A2 recipients, B18 and BW16 (C match) in recipients in the B5 crossreactive group, B5 in B18 recipients, BW22 and B7 in recipients in the B7 crossreactive group. A1 and A11 were transfused successfully bidirectionally. These observations suggest that some private antigens within crossreactive groups are more immunogenic than others and support the observation of others than B17 and BW21 are not in the B5 crossreactive group.

Blood Donors↗

Posttraumatic pilomotor seizures: a case report.

Pilomotor epilepsy is a rare phenomenon. A 35-year-old man suffered a traumatic contusion of the right temporal lobe and subsequently developed spells characterized by diffuse piloerection and sweating. We believe this to be the first reported association between pilomotor epilepsy and posttraumatic head injury. Although pilomotor seizures may result from diverse etiologies, they appear to have a common involvement of temporolimbic structures.

Adult↗

Chemotherapeutic evaluation of 4-hydroxybenzylretinone (4-HBR), a nonhydrolyzable C-linked analog of N-(4-hydroxyphenyl) retinamide (4-HPR) against mammary carcinogenesis.

The antitumor effects of N-(4-hydroxyphenyl)retinamide (4-HPR), and its stable C-linked analog, 4-hydroxybenzylretinone (4-HBR) on the regression of established 7,12-dimethylbenz(a)anthracene(DMBA)-induced rat mammary tumors were compared. 4-HBR is a stable and nonhydroyzable derivative which cannot be converted in vivo to retinoic acid (RA). The results indicate that 4-HBR decreased mammary tumor volumes to the same extent as equimolar concentration (2 mmol/kg diet) of 4-HPR (-45% for 4-HBR vs. -42% for 4-HPR, p<0.01). Both 4-HPR and 4-HBR bind very poorly to nuclear retinoid receptors RARs and RXRs. The similarity of physicochemical properties of 4-HPR and 4-HBR as well as their equal antitumor potency suggests that 4-HPR like 4-HBR, is acting directly rather than through hydrolysis to free RA. Treatment with 4-HPR caused an almost 65% decrease in serum retinol levels. These results suggest that 4-HBR may have a significant chemotherapeutic advantage over 4-HPR, as the nonhydrolyzable analog may not cause night blindness which occurs as a significant side effect of 4-HPR usage.

9,10-Dimethyl-1,2-benzanthracene↗

MR imaging of acute spinal cord trauma.

The thoracic spinal cords of five mongrel dogs were imaged with a 1.5 T MR scanner before and after trauma induced by a well-established method of spinal cord impaction that produces central cord hemorrhagic necrosis. The anesthetized dogs were studied acutely with a 5-in. circular surface coil, 12-cm field of view, sagittal and axial partial-saturation (TR = 600, TE = 25 msec) and spin-echo (TR = 2000, TE = 25-100 msec) techniques. One normal dog was used as a control. The cords were surgically removed and histologically examined. Direct correlation of the pathologic findings and imaging data showed that at the level of trauma there was obliteration of epidural fat and CSF spaces secondary to central cord hemorrhage and edema. The traumatized cords expanded to fill the bony canal, and there was loss of visualization of the internal anatomy of the cord (gray- and white-matter structures). We conclude that MR can accurately identify cord hemorrhage and edema within a few hours of spinal trauma.

Animals↗