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Biomedical subjects

G Hermann

Publications and source records attributed to G Hermann.

At least 253 records · Page 14Linked to original sources
PubMedDate not supplied

Computed tomography of solitary spinal osteochondromas.

Solitary osteochondromas rarely occur in the axial skeleton. These benign tumors may cause a variety of symptoms while remaining difficult to recognize by plain radiographic and myelographic studies. We present three cases of solitary osteochondromas of the spine and demonstrate the CT findings of these unusual tumors.

Adolescent↗
PubMedDate not supplied

Paget disease of the calvaria and facial bones with an osteosarcoma of the maxilla: CT and MR findings.

The CT and magnetic resonance (MR) findings of Paget disease of the calvaria and facial bones are described and compared with one another. The sites of dense, woven bone, myeloid marrow, and background Paget matrix can be clearly identified. A rare case of Paget sarcoma (osteogenic sarcoma) of the facial bones is also presented. The distinction between this sarcoma and the Paget bone was clearer on CT than on MR. This presumably is because the bone is directly seen on CT and only indirectly imaged on MR.

Angiography↗
PubMedDate not supplied

Tumor necrosis factor-alpha in the dorsal vagal complex suppresses gastric motility.

Gastric hypomotility, loss of appetite, nausea, and vomiting frequently accompany critical infectious illness, radiation sickness, and carcinogenesis. The present studies examined the possibility that the pro-inflammatory cytokine, tumor necrosis factor-alpha (TNF-alpha), may be responsible for provoking some of these autonomic signs associated with illness. Gastric motility of urethane-anesthetized rats was prestimulated with intracisternal applications of thyrotropin-releasing hormone (TRH), a peptide known to activate parasympathetic vagal excitatory pathways to the stomach. Microinjection of TNF-alpha (as low as 0.02 fmol) directly into the dorsal vagal comples (DVC) suppressed TRH-stimulated gastric motility for prolonged periods of time. Duration of suppression ranged from 5 min to more than an hour, dependent on both the dose of TNF-alpha and accuracy of placement of the microinjection within the DVC. This suppression demonstrated a dose-dependent effect of TNF-alpha that required an intact vagal pathway. These studies indicate that TNF-alpha may represent a unique cytokine 'afferent' signal which directly regulates the excitability of vago-vagal reflex circuits resulting in altered gastric motility during disease states.

Afferent Pathways↗
PubMedDate not supplied

Ewing's sarcoma of the mandible.

Ewing's sarcoma is an uncommon neoplasm that primarily occurs in the long bones of the lower and upper extremities. Only 2% involve the mandible, and the maxilla is involved one eighth as often as the mandible. The most common site of metastases is the lung. Increasing pain is the most common presenting symptom. A case of mandibular involvement is presented. The combination of a large, soft tissue mass adjacent to an area of bone destruction in a young male should suggest the diagnosis. The previously poor five- and ten-year survival rates of 8 and 4% respectively, may have promise of marked improvement. This improvement lies in a changing philosophy of treatment. Four-drug chemotherapy combined with prophylactic whole-lung irradiation has been added to local irradiation of the tumor bed. Five-year survival figures of 20 to 30% appear obtainable. Although extensive surgical resection of the primary tumor in the long bones has for the most part been replaced by local irradiation for control, surgery in mandibular cases may still be the treatment of choice.

Child↗
PubMedDate not supplied

Discoid medial meniscus: two cases of tears presenting as locked knee due to athletic trauma.

Two patients with a rare, massive type of discoid medial meniscus have been described. Both presented with a locked knee due to athletic trauma in the third and fifth decade of life, respectively. Clinically, discoid meniscus has only nonspecific signs. The arthrogram has proved to be a helpful preoperative diagnostic tool. Definitive diagnosis and treatment can be made with arthroscopy.

Adult↗
PubMedDate not supplied

The innominate steal syndrome.

Two patients with isolated innominate artery occlusion presented with symptoms of significant right-sided cerebrovascular insufficiency. One of these also noted progressive pain and weakness of the right upper extremity. Both were treated with dacron bypass grafts from the ascending aorta to the innominate bifurcation with complete relief of all symptoms. Unlike the subclavian steal, innominate artery occlusion induces distinct and much more significant hemodynamic alterations in extracranial arterial flow and is rarely asymptomatic. Three distinct patterns of blood flow have been described secondary to this lesion. Correction is best achieved by either innominate artery endarterectomy or dacron bypass grafting which the authors favor. Extra-anatomic bypasses represent a less satisfactory solution except in the poor risk patients. Long term relief of symptoms and patency of the reconstruction have been generally achieved by either of the recommended techniques.

Animals↗
PubMedDate not supplied

CT evaluation of the greater sciatic foramen in patients with sciatica.

Sciatic and lower extremity neurologic symptoms may be from pathologic involvement of the sacral plexus or sciatic nerve in the region of the greater sciatic foramen. Twenty-five patients were reviewed who presented consecutively over a 4 year period with sciatic symptoms secondary to pathologic changes in the greater sciatic foramen. Malignant neoplasm alone (18 patients) and malignant neoplasm associated with infection (two patients) account for most of these cases. Neurogenic tumors (three patients), both benign and malignant, and infection alone (three patients) were less frequent. Although sciatic symptoms usually derive from spinal abnormalities, the evaluation of sciatic symptoms should not be considered complete without CT scanning of the greater sciatic foramen.

Adult↗
PubMedDate not supplied

Changes of the intramyocardial electrogram after orthotopic heart transplantation.

Heart transplantation, including conventional immunosuppression, has allowed the use of the surface electrocardiogram to detect allograft rejection. With the use of cyclosporine this parameter is no longer sensitive, but voltage of the intramyocardial electrogram has correlated repeatedly with rejection. From July 1983 through February 1986, 98 patients had heart transplantation; 13 of those patients had a telemetry pacemaker simultaneously implanted. In previous studies, daytime dependent variabilities of the sum voltage of the surface electrocardiogram were reported. Therefore intramyocardial electrogram was measured at 7, 10, 13, 16, and 20 hours. In addition, the influence of exercise on intramyocardial electrogram voltage was studied in all patients. Analysis of the diurnal intramyocardial electrogram revealed substantial atrial and ventricular variability of both voltage measurements (p less than 0.05). Also, intramyocardial electrogram voltage was influenced by exercise, as demonstrated by a significant decrease after physical work at 25 W (-8%) and 50 W (-12%); p less than 0.05. Therefore we conclude that a high variability of intramyocardial electrogram may be found diurnally and on exercise testing after heart transplantation in humans. If intramyocardial electrogram is used to detect rejection, it should be applied at comparable hours and with the patients in a controlled resting state.

Adolescent↗