Rotational occlusion of the vertebral artery at the atlantoaxial joint: is it truly physiological?

We present a patient with vertebrobasilar insufficiency, with vertigo and horizontal nystagmus, induced by turning the head to the right. Angiography demonstrated transient occlusion of the left vertebral artery at the atlantoaxial joint during rotation of the head. The pathogenesis and angiographic findings are discussed.     

Prognostic significance of the expression of ras oncogene product in non-small cell lung cancer.

The clinical significance of ras oncogene expression in non-small cell lung cancer was evaluated in 116 surgically treated patients. Archival paraffin sections of the tumors were analyzed immunohistochemically using anti-ras p21 monoclonal antibody (MoAb) rp-35, and p21 staining was correlated with clinicopathologic parameters and survival. Positive reactions (+ and ++) were observed in 72.5% of the adenocarcinomas and 55.6% of the squamous cell carcinomas studied. The T1 tumors showed a ++ reaction less frequently than T2 and T3 tumors (P less than 0.05). Stage I tumors also were less reactive with MoAb rp-35 than tumors in more advanced stages (P less than 0.05). Survival analysis showed that patients with p21-negative tumors had significantly longer survival times (a 5-year survival rate of 64.1%) than those with p21 + tumors (38.0%, P less than 0.05) or those with p21 ++ tumors (11.5%, P less than 0.005). The significant correlation between p21 staining and patient survival was independent of histologic type, stage of disease, tumor or node status, and the resectability of tumors. On Cox's multivariate analysis, p21 staining was a major and independent prognostic determinant of survival. These results suggest that enhanced ras p21 expression may be one of the important biologic and clinical markers indicating the malignant potential of non-small cell lung cancer.     

Orthotopic allotransplantation of the canine liver; a simplified technic with hypothermia

A simplified technique of the liver transplantation under hypothermia has been studied in dog. An immersion hypothermia was used in both the donor and the recipient. The temperature of the graft at excision was lowered to 20 degrees C with supplemental use of topical cooling. The temperature of the recipient was lowered at 27 degrees C when the transplantation was attempted. Chlorpromazine and dopamine were employed beneficially in hypothermia. No perfusion or irrigation of the graft was performed. The use of heparin was avoided. Anastomoses were carried out in turn of the proximal vena cava, portal vein, distal vena cava and the hepatic artery with a stem shaped aorta. Reperfusion was established after the completion of anastomosis between the proximal vena cava and portal vein. The anhepatic phase of the recipient was uneventfully lasted without heparinization. All dogs, 5 out of 11 without early surgical troubles survived more than 5 days. Immunosuppressive therapy was not employed except one which died of pneumonia on the 19th postoperative day. Histologically, these dogs were free from ischemic injury and/or thrombotic lesion throughout transplantation procedure.     

Detection limit in low-amplitude EEG measurement.

Electrocerebral inactivity for the determination of cerebral death is defined as no findings of EEG greater than the amplifier's inherent internal noise level when recording at increased sensitivity. A surface biopotential electrode contains two interfaces composed of skin gel (electrolyte) and gel electrode (metal), each forming a noise source. The power spectral density, S(f), of extremely low noise signals was obtained by means of autocorrelation and fast Fourier transformation. Interelectrode resistance, R(f), was measured with synchronous rectification. The formula of equivalent noise resistance R(n) = S(f)/4kT, where k is the Boltzmann constant and T is room temperature in Kelvin, gives a resistance that generates the thermal noise corresponding to the measured S(f). Rn/R is a parameter derived from normalization by R. When Rn/R = 1, measured noise contains thermal noise only. Meanwhile, Rn/R > 1 indicates presence of excess noise, such as 1/f, and tissue noise in addition to the thermal noise. Mean square root (Rn/R) of the scalp noise was 10.8 at 10 Hz, showing existence of excess noise. The study results suggest that it is necessary to take excess noise into consideration in the measurement of low-amplitude EEG for the determination of cerebral death.     

Response of postapoplectic hemichorea/ballism to GPi pallidotomy: progressive improvement resulting in complete relief.

We report on a 66-year-old woman in whom GPi pallidotomy produced progressive and eventually complete relief of hemichorea/ballism (HCB) after a subthalamic hemorrhage. Although choreoballistic movements were unchanged during and immediately after the surgery, the symptoms were gradually improved and consequently abolished by 5 days postoperatively. HCB has never recurred up to the present (9 months follow-up period). This note is the first report describing detailed postsurgical process in HCB relief after pallidotomy.     

Postoperative changes in the spinal cord in cervical myelopathy demonstrated by magnetic resonance imaging.

The relation between improvement of myelopathy achieved by surgery and postoperative spinal cord morphologic changes was investigated by magnetic resonance imaging in 51 patients with cervical myelopathy. In 22 patients, the cord indentation disappeared completely (Type I), in 23 it partially disappeared (Type II), and in 3 it remained unchanged (Type III). In three patients the cord enlarged after surgery (Type IV). With the exception of Type IV, increased restoration of cord morphology paralleled improvement in the myelopathy, suggesting that morphologic changes closely reflect neurologic recovery. In Type IV, notwithstanding the peculiar postoperative reaction, improvement was relatively good, and shrinkage of the cord enlargement was seen after 1 year. This kind of postoperative change has not been demonstrated previously by other conventional imaging methods.