Hemopoietic neoplasms in lethally irradiated mice repopulated with bone marrow cells carrying the human c-myc oncogene: a repopulation assay.

Bone marrow (BM) cells from two transgenic mice carrying the human c-myc oncogene were separately harvested, and each sample was injected into 25 lethally irradiated mice. We observed the contribution of the myc gene to the occurrence of hemopoietic neoplasms in the BM-repopulated mice, establishing a new experimental system for analyzing oncogene expression in the hemopoietic system in vivo. The hybrid gene that was transferred into the original transgenic mice was a combination of the human c-myc gene with a regulatory unit consisting of a murine immunoglobulin-heavy chain with an SV40 early-T promoter gene (Ig/Tp-myc). Among the transgenic lines, the tested BM cells were chosen from two lines that had been low-prone in leukemia; in these lines hemopoietic neoplasms did not appear for greater than or equal 200 days after birth. Lethally irradiated controls received BM cells from litters of transgenic mice that did not carry c-myc. The lifetime incidence of hemopoietic neoplasms was 94% and 91% in the two groups of mice repopulated with myc+ BM. By contrast, only 15% of control mice with myc- BM developed hemopoietic lesions. The incidence of hemopoietic malignancies combined with nonthymic lymphomas and myeloma cases (88% and 65%) was higher in the repopulated mice than the incidence of pre-B cell lymphomas in the original transgenic lines (56%). Thirty-two of the 40 myc+ mice that were examined showed the presence of the transferred gene in either the normal hemopoietic tissue or in the hemopoietic neoplasm. Furthermore, 18 of 22 hemopoietic neoplasms studied by Northern hybridization expressed mRNA from the transgenic gene; in other four neoplasms, expression was weak or absent.     

Usefulness of two-dimensional time-of-flight MR angiography combined with surface anatomy scanning for convexity lesions

Thirty-eight patients with convexity lesions were studied prospectively with the two-dimensional time-of-flight (2D-TOF) magnetic resonance angiography (MRA) method. Of these 21 cases had additional surface anatomy scanning (SAS) and 7 cases had three-dimensional phase contrast (3D-PC) MRA. The findings were compared during surgery, and the predictability of 2D-TOF evaluated. 2D-TOF was obtained with 2 mm slice thickness after the administration of contrast media for routine magnetic resonance imaging (MRI). Cortical veins were visualized with a good resolution with a scan time of only 5 minutes. The tumor was also visible in the background, due to enhancement, and thus the tumor-vessels relation was shown. Slow-flow vessels were also adequately seen. SAS was done at the same sitting with fast spin echo (FSE) with a scan time of 3 minutes. Once both images were incorporated, information on gyri and their relation to the lesions and vasculature could be obtained from a single image. We found 2D-TOF alone, or at times in combination with SAS, useful for planning of operation for convexity lesions.     

Bilateral subclavian steal associated with severe coarctation of the thoracic aorta and an aberrant right subclavian artery

A 10-year-old girl having bilateral subclavian steal associated with severe coarctation of the thoracic aorta and an aberrant right subclavian artery was found, on admission, to have no difference between upper and lower extremity blood pressure, but echocardiography revealed severe thoracic aorta coarctation and systolic blood pressure in the carotid arteries exceeding 200 mmHg estimated by Doppler ultrasonography. Magnetic resonance imaging and angiography demonstrated bilateral subclavian steal without esophageal compression. We reconstructed the aortic arch using the left subclavian artery and a reversed Blalock-Park procedure, then repaired the coarctation with a 14 mm woven double velor vascular graft. The girl was symptom-free following uncomplicated recovery from surgery. Doppler ultrasonography 2 weeks after surgery showed the pressure gradient across the aortic arch had decreased from 180 mmHg to 60 mmHg. This residual gradient at the anastomosis between the ascending aorta and left subclavian artery may improve as native vessels grow.     

Prosthetic valve endocarditis due to candida albicans treated successfully with medical treatment alone

Prosthetic valve endocarditis (PVE) caused by Candida species is associated with high morbidity and mortality. A combination of surgical resection and antifungal drug therapy is the golden standard for treatment, yet surgical intervention is not possible in all cases of Candida PVE. We report a case of PVE due to Candida albicans cured by medical treatment alone. This case suggests that, in some instances, Candida PVE can be managed medically with antifungal therapy. Such a conservative approach should be applied with caution and necessitates very close follow-up on a long-term basis.     

Combined aortic and mitral valve repair in active infective endocarditis

We describe a case of successful combined repair of the aortic and mitral valves for an indication of active infective endocarditis involving both valves. Mitral valve repair was achieved by vegetation debridement, fixation of the anterior mitral commissure, resection and suturing of the posterior mitral leaflet, and posterior annuloplasty with autologous pericardium. Aortic valve repair was achieved by vegetectomy and commissural plication. Postoperative clinical course was without signs of recurrent infection, and echocardiogram demonstrated mitral valve competence with trivial aortic regurgitation. We concluded that simultaneous valve repair is a viable option in the context of active endocarditis.     

A study on the development of a filing system for funduscopic images with a personal computer for Twin AMHTS

A filing system for ocular fundscopic image data was developed by using a personal computer for the Twin AMHTS. The development of the system was tried as one of the data transfer system including image data between two similar AMHTSs named the Twin AMHTS through the information network system. The filing system is capable of storing 26782 data of ophthalmoscopic pictures with a data compression mode by using a magneto-optical disk (MOD) whose storage capacity of both sides is 616 MB. It takes no long time for retrieval and display of the image data in the filing system. Good quality of compression and decompression obtained and reproducibility of the ocular fundus picture is favorable regardless of normal or abnormal cases. As a result, it is suggested that the developed system has practical utility although it requires more improvement.     

Effect of sleep on interictal spikes and distribution of sleep spindles on electrocorticography in children with focal epilepsy.

OBJECTIVE: To determine how sleep with central spindles alters the spatial distribution of interictal spike frequency in children with intractable focal seizures, and whether such children have spindles arising from the medial temporal region in addition to the frontal-central region. METHODS: Seventeen children (age: 7 months-17 years) were studied using extraoperative electrocorticography (ECoG). RESULTS: Overall spike frequency across the subdural electrodes was greater during sleep with central spindles compared to wakefulness. In 13 children showing at least 1 spike/min in an electrode, the spatial distribution of spike frequency was similar during wakefulness and sleep; in addition, the spike frequency was greater in the seizure onset zones compared to the non-onset areas, regardless of wakefulness or sleep. Spindles were identified in the medial temporal region during sleep with central spindles in all 17 children. CONCLUSION: Overall spike frequency may be increased by sleep with spindles, but the spatial distribution of spike frequency appears similar during wakefulness and sleep in children with intractable focal seizures. SIGNIFICANCE: Both awake and sleep ECoG may be useful to predict seizure onset zones in children with intractable focal epilepsy. Medial temporal spindles are present in some children with focal epilepsy.     

CUSHING'S SYNDROME WITH BILATERAL MULTINODULAR ADRENAL HYPERPLASIA

An unusual case of Cushing's syndrome of a 59-year-old man with bilateral multinodular adrenal hyperplasia and microadenoma of the pituitary gland is presented. Failure to suppress plasma Cortisol with large doses of dexamethasone may suggest autonomous growth of hyperplastic nodules of the adrenals, which were at first induced by prolonged stimuli of ACTH from the microadenoma of the pituitary gland. ACTH could not be detected in the microadenoma cells on paraffin sections, while Crooke's cells were strongly positive for ACTH. The interrelation between bilateral multinodular adrenal hyperplasia and pituitary microadenoma is discussed.