Neural mechanisms for object and color recognition]

We reported double-dissociation between the visual processing of the edges and the surfaces of objects. Patients with lateral occipital damage showed selective impairment in the perception of edges whereas those with medial ventral occipital damage showed selective impairment in the perception of the 3D structure of the surface. Patients with medial ventral occipital damage also exhibited impaired perception of color, which is also a surface property. Those results were consistent with those from neuroimaging studies. Taken together, those studies suggest that objects may be processed in two separate pathways in the ventral occipital cortex: the edges of objects are processed in the lateral pathway and the surface of objects are processed in the medial pathway. Both edges and surfaces play important roles in object recognition, and both types of perception should be evaluated in patients with visual agnosia.     

Effects of hyperbaric oxygen exposure on experimental hepatic ischemia reperfusion injury: relationship between its timing and neutrophil sequestration.

Recent studies have shown that hyperbaric oxygen therapy (HBOT) reduces neutrophil endothelial adherence in venules and also blocks the progressive arteriolar vasoconstriction associated with ischemia-reperfusion (I-R) injury in the extremities and the brain. In order to elucidate the effects of HBOT after I-R in digestive organs, particularly in the liver, we evaluated the following: 1) the relationship between timing of HBOT and tissue damage; and 2) HBOT's effects on neutrophil sequestration. Using a hepatic I-R (45 minute) model in male rats, survival rate, liver tissue damage, and neutrophil accumulation within the sinusoids in the HBOT-treated group (Group H) were compared to those in the nontreated group (Group C). For the HBOT-treated group, HBOT was administered as 100% oxygen, at 2.5 atm absolute, for 60 minutes. When HBOT was given 30 minute after I-R, the survival rate was much better in Group H than in Group C. HBOT performed within 3 hours of I-R markedly suppressed increases in the malondialdehyde level in tissues of the liver and lessened the congestion in the sinusoids. In addition, HBOT just after I-R caused decreased number of cells stained by the naphthol AS-D chloroacetate esterase infiltrating into the sinusoids. HBOT 3 hours after reperfusion, however, showed no clear effects upon neutrophil sequestration compared to Group C. These results indicate that HBOT performed within 3 hours of I-R alleviates hepatic dysfunction and improves the survival rate after I-R. Herein, we propose 1 possible mechanism for these beneficial effects: early HBOT given before neutrophil-mediated injury phase may suppress the accumulation of neutrophils after I-R. In conclusion, we believe that the present study should lead to an improved understanding of HBOT's potential role in hepatic surgery.     

Deep vein thrombosis in the psychiatric patients under physical restraint]

Pulmonary thromboembolism induced by deep vein thrombosis (DVT), which is known as economy-class syndrome, is one of sudden death in psychiatric patients under physical restraint. (1) A decrease in venous blood flow, (2) damage to vessel walls, and (3) the enhancement of blood clotting are the major risk factors for DVT (Virchow triad). It has been speculated that physical restraint inhibits venous blood flow, and that antipsychotic drugs facilitate blood clotting. In order to prevent sudden death due to DVT, prophylactic measures and early diagnosis are crucial. Whereas Doppler ultrasonography and contrast venography are the gold standards for the diagnosis of DVT, more simplified methods are now under development. Of those, D-dimer measurement, which can be conducted with a small blood sample, is the most potent candidate for the biochemical diagnosis of DVT. Although there are many prophylactic measures, including anticoagulant medications and physical therapies, it is not clear which is the most effective and suitable in psychiatric practice. Psychiatric professionals should pay closer attention to DVT in psychiatric patients under physical restraint.     

Comparison of neurocognitive results after coronary artery bypass grafting and thoracic aortic surgery using retrograde cerebral perfusion.

OBJECTIVE: Retrograde cerebral perfusion (RCP) is used as an adjunctive method to hypothermic circulatory arrest to enhance cerebral protection in patients undergoing thoracic aortic surgery. It remains unclear whether RCP provides improved neurological and neuropsychological outcome. METHODS: Forty-six patients undergoing thoracic aortic surgery using RCP, and 28 undergoing coronary artery bypass grafting (CABG; n = 28) with CPB, were enrolled in the study. Patients receiving RCP were subdivided into two groups, those with less than 60 min of RCP (S-RCP; n = 27) and with 60 min or more (L-RCP; n = 19). The patients' neurocognitive state was assessed by the revised Wechsler Adult Intelligence Scale a few days before operation, at 2-3 weeks and 4-6 months after operation. RESULTS: There were no stroke, seizure, and hospital mortality in either group. Significant decline between baseline and early scores were seen in three subtests (digit span, arithmetic, and picture completion) for S-RCP and four (digit span, arithmetic, picture completion, and picture arrangement) for L-RCP. Significant decline between baseline and late scores were seen in one subtest (arithmetic) for S-RCP, four (digit span, arithmetic, picture completion, and picture arrangement) for L-RCP, and one (object assembly) for CABG. The mean change of scores for one late test (digit symbol) was significantly lower in S-RCP than in CABG. The mean change of scores for three early tests (digit span, vocabulary, and picture arrangement) and four late tests (information, digit span, picture completion, and picture arrangement) were significantly lower in L-RCP than in CABG. Stepwise logistic regression analysis disclosed that, after considering the other variables, significant difference in test score changes were observed between CABG and L-RCP for two early tests (picture completion and digit symbol) as well as for three late tests (digit span, similarities, and picture completion). None of test score changes showed significant difference between CABG and S-RCP. CONCLUSIONS: The neurocognitive outcome in patients undergoing RCP less than 60 min were comparable with patients undergoing CABG without circulatory arrest. Prolonged RCP of 60 min or more in patients undergoing surgery of the thoracic aorta was associated with postoperative neurocognitive impairment.     

Cardiac function predicts mortality following thoracoabdominal and descending thoracic aortic aneurysm repair.

OBJECTIVE: Previous studies have identified age, renal failure and aneurysm extent as predictors of mortality following thoracoabdominal and descending thoracic aortic aneurysm (TAA) repair. We studied the impact of coronary artery disease (CAD) and cardiac function on 30-day mortality following TAA repair. METHODS: Between February 1991 and May 2001, we performed 854 TAA repairs. Two hundred ninety-one patients (34%) had a history of coronary artery disease. One hundred forty-one/291 (49%) had undergone coronary artery bypass surgery (CAB) prior to TAA repair. We conducted multivariable analyses of known risk factors along with the left ventricular ejection fraction (EF) and prior CAB to determine the adjusted effect of CAD on outcome. RESULTS: Mortality in patients with CAD was 54/291 (18%) compared to 75/563 (13%) without CAD (P<0.05). In patients who had prior CAB, mortality was 31/141 (22%) compared to 98/713 (14%) patients without prior CAB, (P<0.02). In multivariable analysis, the effects of CAD and CAB on mortality were eliminated by consideration of a low EF (defined as less than 50%). CONCLUSION: Impaired left ventricular function appears to be the strongest cardiac predictor of mortality for TAA repair, independent of the presence of coronary artery disease or coronary artery bypass revascularization.     

Light-scattering study of depolymerization kinetics of sickle hemoglobin polymers inside single erythrocytes.

The time course of intracellular depolymerization of hemoglobin S aggregates is directly observed by using microscope laser light-scattering spectroscopy in single sickle erythrocytes upon slow reoxygenation. From the correlation functions of the light intensity scattered from a single cell, we determine the average diffusion coefficient as well as the fraction of hemoglobin aggregates that have intracellular mobility. The oxygen saturation of the hemoglobin of the same cell is measured by single-cell absorption spectrophotometry. Combining the results obtained with these techniques and information on the cellular morphology, we propose a model for the depolymerization process of hemoglobin inside single erythrocytes as they transform from the fully sickled to the normal biconcave shape upon reoxygenation.     

Clinicopathologic Study of Angiogenesis in Japanese Patients with Breast Cancer

p = 0.0007) and tumor necrosis (TN) (HMC: p = 0.0050). Univariate analysis showed that AMC or HMC was a statistically significant predictor of overall survival in all patients ( p = 0.0086 and p = 0.0307, respectively). Multivariate analysis showed that AMC was an independent predictor of node status when we fitted a model with node status, BVI, and either AMC or HMC; but HMC was not independent. However, when we fitted a model including all 11 of the other indicators and AMC or HMC, the node status, HG, and LI were independent predictors, but AMC and HMC were not. Although AMC was a better method than HMC for evaluating angiogenesis, we cannot confirm angiogenesis as a significant independent prognostic factor associated with long-term survival in Japanese breast cancer patients.     

Prediction of morbidity after lung resection with risk factors using treadmill exercise test.

OBJECTIVE: To predict accurate morbidity after lung resection using treadmill exercise test. METHODS: A total of 130 patients (108 men and 22 women, with mean age 67.1+/-11.4 years (range, 34-78 years)) of 1129 patients underwent standard lobectomy were performed both treadmill exercise test and spirometry preoperatively. We measured maximum oxygen uptake/body weight (VO2max/BW) and change in arterial blood oxygen pressure from rest to symptom-limited maximum loading (delta aPaO2) and calculated exercise-induced hypoxemia (delta PaO2/delta VO2/BW), and retrospectively compared these parameters for patients with and without complications. RESULTS: There were five patients with severe postoperative complications, including three requiring use of a respirator, two with home oxygen therapy. %Vital capacity, VC (%, 80.2+/-13.2 vs. 92.5+/-20.9, P=0.026), delta PaO2 (Torr, -29.3+/-4.3 vs. -13.2+/-10.8, P=0.0004), VO2max/BW (ml/min/kg, 16.5+/-2.9 vs. 20.6+/-5.1, P=0.018) and delta PaO2/delta VO2/BW (Torr/ml/min/kg, -1.98+/-0.26 vs. -0.57+/-0.47) were significantly associated with worse outcome. All the five patients with complications had delta PaO2/delta VO2/BW<-1.7. CONCLUSIONS: Treadmill exercise testing is a good method for assessment of cardiopulmonary reserve. Limited resection must be performed if delta PaO2/delta VO2/BW is under -1.7.     

Germ cell tumor in the hypothalamo-neurohypophysial region: clinical features and treatment

Twenty-one patients with germ cell tumors (17 germinomas and 4 teratomas) involving the hypothalamic-neurohypophysial (HN) region were reviewed retrospectively. Eleven patients were males and 10 females, and their ages ranged from 7 to 45 years (average 18.5 years). Diabetes insipidus was the initial and the most prominent symptom in most germinomas; in teratomas the most prominent symptom was visual disturbance. Fifteen patients with germinomas were treated by radiotherapy, and 4 with teratomas were treated by surgical resection alone. Two recent germinoma patients with extensive CSF dissemination were treated with systemic chemotherapy consisting of anticancer platinum drugs and etoposide, which resulted in a complete disappearance of the tumors. Patients with germinoma treated after the introduction of CT scanning had a greatly improved mortality rate, and their actual survival rate was 87.5% over 10 years. On the basis of this review, the authors consider that diagnosis at an early stage of the disease and chemotherapy, which can be an effective therapeuric alternative to radiation therapy, may improve not only the mortality rate but also the quality of life of patients with HN germ cell tumors.