Mild head injury increasing the brain's vulnerability to a second concussive impact

OBJECT

Mild, traumatic repetitive head injury (RHI) leads to neurobehavioral impairment and is associated with the early onset of neurodegenerative disease. The authors developed an animal model to investigate the behavioral and pathological changes associated with RHI.

METHODS

Adult male C57BL/6 mice were subjected to a single injury (43 mice), repetitive injury (two injuries 24 hours apart; 49 mice), or no impact (36 mice). Cognitive function was assessed using the Morris water maze test, and neurological motor function was evaluated using a battery of neuroscore, rotarod, and rotating pole tests. The animals were also evaluated for cardiovascular changes, blood-brain barrier (BBB) breakdown, traumatic axonal injury, and neurodegenerative and histopathological changes between 1 day and 56 days after brain trauma. No cognitive dysfunction was detected in any group. The single-impact group showed mild impairment according to the neuroscore test at only 3 days postinjury, whereas RHI caused pronounced deficits at 3 days and 7 days following the second injury. Moreover, RHI led to functional impairment during the rotarod and rotating pole tests that was not observed in any animal after a single impact. Small areas of cortical BBB breakdown and axonal injury. observed after a single brain injury, were profoundly exacerbated after RHI. Immunohistochemical staining for microtubule-associated protein-2 revealed marked regional loss of immunoreactivity only in animals subjected to RHI. No deposits of beta-amyloid or tau were observed in any brain-injured animal.

CONCLUSIONS

On the basis of their results, the authors suggest that the brain has an increased vulnerability to a second traumatic insult for at least 24 hours following an initial episode of mild brain trauma.

Ski7p G protein interacts with the exosome and the Ski complex for 3'-to-5' mRNA decay in yeast

Two cytoplasmic mRNA-decay pathways have been characterized in yeast, and both are initiated by shortening of the 3'-poly(A) tail. In the major 5'-to-3' decay pathway, the deadenylation triggers removal of the 5'-cap, exposing the transcript body for 5'-to-3' degradation. An alternative 3'-to-5' decay pathway also follows the deadenylation and requires two multi-complexes: the exosome containing various 3'-exonucleases and the Ski complex consisting of the RNA helicase Ski2p, Ski3p and Ski8p. In addition, Ski7p, which has an N-terminal domain and a C-terminal elongation factor 1alpha-like GTP-binding domain, is involved in the 3'-to-5' decay. However, physical interaction between the exosome and the Ski complex, together with the function of Ski7p, has remained unknown. Here we report that the N domain of Ski7p is required and sufficient for the 3'-to-5' decay. Furthermore, the exosome and the Ski complex interact with the different regions of Ski7p N domain, and both interactions are required for the 3'-to-5' decay. Thus, Ski7p G protein appears to function as a signal-coupling factor between the two multi-complexes operating in the 3'-to-5' mRNA-decay pathway.

[Case report of CABG for progressive coronary artery stenosis after 22-year history of Kawasaki disease]

More than 30 years has passed since Kawasaki disease was recognized as an independent disease entity, but the cardiovascular complications of Kawasaki disease are still not well known. We report an 22-year-old woman who underwent triple coronary artery bypass grafting because of a coronary artery aneurysm and multiple coronary artery stenoses, 22 years after the diagnosis of Kawasaki disease. A 2 cm coronary artery aneurysm due to Kawasaki disease was diagnosed when she was 10 years old, when she first presented with the symptom of dyspnea on effort. Since then, she was followed at the outpatient clinic. When she was 19 years old, the first coronary catheterization was performed. Two years later, the second coronary catheterization revealed progression of coronary artery disease. Therefore, coronary artery bypass grafting was performed. This case is rare from the point of view of long-term progression of coronary artery disease.

Predicting blood transfusion factors in coronary artery bypass surgery

OBJECTIVE

Blood conservation has become one of the most important issues in cardiac surgery. We clarified preoperative predictors of the need for blood transfusions during coronary artery bypass graft surgery.

METHODS

Subjects were 89 patients--66 men (74%) and 23 women (26%) 40 to 84 years old (mean: 66.2 +/- 8.3 years)--undergoing isolated coronary artery bypass surgery from September 1997 to December 1999. Of these, 66 patients (74%) received transfusion during hospitalization and 23 (26%) did not. Nine risk factors detected by univariate study were entered in a multivariate logistic regression model of the relationship between preoperative variables and blood transfusion.

RESULTS

Independent predictors were emergency surgery (P = .0023), lower hematocrit (P = .0027), older age (P = .0043), and the presence of peripheral vascular disease (P = .0070). Optimal cutoff of hematocrit for blood transfusion was 39% and age 64 years via receiver-operating characteristics curves based on the relation between sensitivity and specificity.

CONCLUSION

Patients older than 64 years with hematocrit less than 39% and/or peripheral vascular disease should be treated routinely using preoperative storage of autologous blood whenever the patient's condition permits. For patients undergoing emergency surgery, further studies are required, including lowering transfusion threshold and using determinants other than hematocrit.

Results of 256 consecutive abdominal aortic aneurysm repairs using extraperitoneal approach

Two hundred and fifty-six consecutive abdominal aortic aneurysms were repaired using three approaches for extraperitoneal exposure of the aorta and iliac vessels from February 1990 through September 1998. The perioperative mortality rate was 3.1% in 228 elective repairs and 14.3% in 28 ruptured cases. The initial 23 cases were repaired using Sicard's method. The duration of endotracheal intubation was 1.0+/-2.8 h, alimentation initiation was 2.7+/-1.6 days, and narcotic requirements were 1.2+/-1.1 times. Following these initial cases, we employed Williams' method for 192 abdominal aneurysms, however; repeated incisional pain and three cases of deforming bulge led us to avoid dividing muscles. In the last 13 cases, our approach was performed without muscle dividing. The narcotic requirements decreased to 0.3+/-0.7 times. As for postoperative complications, the larger skin incision approach had no shower embolism. However, the shorter skin incision had four cases of shower embolisms, one lymphorrhea and one vascular trauma by the aortic clamp. The extraperitoneal approach offers certain physiologic advantages with minimal disturbance of gastrointestinal and respiratory function. We believe that this method is useful for rapid approach to the proximal aorta in case of emergency. Postoperative wound complications could be prevented via an oblique incision without muscle dividing.

Association of bone mineral density with a dinucleotide repeat polymorphism at the calcitonin (CT) locus

Calcitonin (CT), a calcium-regulating hormone, lowers the calcium level in serum by inhibiting bone resorption. Because CT may play a role in the pathogenesis of osteoporosis, genetic variations in or adjacent to the CT gene may be associated with variations in bone mineral density (BMD). The present study examined the correlation between a dinucleotide (cytosine-adenine; CA) repeat polymorphism at the CT locus and BMD in 311 Japanese postmenopausal women (mean age, 64.1 years). Seven alleles were present in this population; each allele contained 10, 11, 16, 17, 18, 19, or 20 CA repeats. Thus, we designated the respective genotypes A10, A11, A16, A17, A18, A19, and A20. The A10 and A17 alleles were the predominant alleles in the population studied. Z scores (a parameter representing deviation from the age-specific weight-adjusted average BMD) were compared between individuals that possessed one or two alleles of each genotype and those that did not possess the allele. Subjects who possessed one or two A10 alleles had lower BMD Z scores than those who did not (lumbar 2-4 BMD Z score; -0.148 +/- 1.23 vs 0.182 +/- 1.54; P = 0.04). No significant relationships were observed between allelic status and background data or biochemical parameters. The significant association observed between BMD and genetic variations at the CT locus implies that polymorphism at this locus may be a useful marker for the genetic study of osteoporosis.

Japanese fermented soybean food as the major determinant of the large geographic difference in circulating levels of vitamin K2: possible implications for hip-fracture risk

Increasing evidence indicates a significant role for vitamin K in bone metabolism and osteoporosis. In this study, we found a large geographic difference in serum vitamin K2 (menaquinone-7; MK-7) levels in postmenopausal women. Serum MK-7 concentrations were 5.26 +/- 6.13 ng/mL (mean +/- SD) in Japanese women in Tokyo, 1.22 +/- 1.85 in Japanese women in Hiroshima, and 0.37 +/- 0.20 in British women. We investigated the effect of Japanese fermented soybean food, natto, on serum vitamin K levels. Natto contains a large amount of MK-7 and is eaten frequently in eastern (Tokyo) but seldom in western (Hiroshima) Japan. Serum concentrations of MK-7 were significantly higher in frequent natto eaters, and natto intake resulted in a marked, sustained increase in serum MK-7 concentration. We analyzed the relation between the regional difference in natto intake and fracture incidence. A statistically significant inverse correlation was found between incidence of hip fractures in women and natto consumption in each prefecture throughout Japan. These findings indicate that the large geographic difference in MK-7 levels may be ascribed, at least in part, to natto intake and suggest the possibility that higher MK-7 level resulting from natto consumption may contribute to the relatively lower fracture risk in Japanese women.

[A case of tracheo-bronchial stenosis after extended end-to-end aortic arch anastomosis for interrupted aortic arch treated with suspension of the ascending artery and pulmonary artery]

A 9-day-old boy had pulmonary artery banding and extended end-to-end aortic arch anastomosis for ventricular septal defect (VSD) and type A interrupted aortic arch. Severe dyspnea gradually developed. At 3 months of age, intracardiac repair of VSD was performed. Weaning from the ventilator was difficult. Endoscopic examination and chest CT revealed stenosis of the right and left main bronchi and compression of tracheal bifurcation and the right and left main bronchi by the ascending aorta and pulmonary artery. Suspension of the ascending aorta and pulmonary artery was performed 15 days after VSD closure. Nine days after this procedure, the patient was weaned from respirator. Postoperative course was uneventful. Bronchial stenosis may be caused from extended end-to-end aortic arch anastomosis.

[Experiences of minimally invasive great saphenous vein graft harvest using with endopath]

We have experienced 20 cases of minimally invasive great saphenous vein graft harvest using with endoscopy, Endopath, from March 1999. As we experienced cases, we can harvest great saphenous vein graft, about 30-40 cm in size, from only two 4-cm incisions for about 50 minutes. There are no wound infection, pain, and edema. Great saphenous vein graft harvesting with Endopath is less invasive, painless after surgery and makes patients satisfied about cosmetic problem.

Recombinant human erythropoietin therapy for autologous blood donation in rheumatoid arthritis patients undergoing total hip or knee arthroplasty

The effect of recombinant human erythropoietin on autologous blood donation was investigated in 73 rheumatoid arthritis patients who underwent hip or knee arthroplasty. Autologous blood donation of 400 mL was successful with recombinant human erythropoietin (12,000 U per week), and no homologous blood was required. The mean period of blood collection was 33.8 days. Mean hemoglobin levels were 9.7 g/dL before treatment, 10.7 g/dL before surgery, and 10.2 g/dL after surgery. This study confirmed recombinant human erythropoietin is effective for enabling preoperative blood donation in rheumatoid arthritis patients.

An estrogen receptor beta isoform that lacks exon 5 has dominant negative activity on both ERalpha and ERbeta

An alternatively spliced isoform of human estrogen receptor beta (ERbeta) has been isolated from normal human testis mRNA that is coexpressed with wild-type ERbeta by reverse transcription polymerase chain reaction (RT-PCR). Sequence analysis of the ERbeta isoform PCR product reveals the absence of 139 bp that corresponds to the entire exon 5 of wild-type ERbeta, which predicts to lack part of the hormone-binding domain. The transient expression of the exon 5-deleted isoform of ERbeta (ERbetaDelta5) had no effect on basal transactivation activity of an estrogen-responsive luciferase reporter gene. This finding was in contrast to the previous reports that the exon 5-deleted isoform of ERalpha (ERalphaDelta5) acts as a dominant positive receptor, increasing basal gene transactivation itself. Moreover, when ERbetaDelta5 was cotransfected with the wild-type ERalpha or ERbeta, it behaved as a dominant negative receptor that inhibited not only estradiol-stimulated transactivation by ERbeta but also that by ERalpha. The ligand-independent nuclear localization of ERbetaDelta5 was confirmed by immunohistochemistry, and the coexpression of the isoform and the wild-type receptors could be observed in a single cell that transfected with both receptor cDNAs. These findings indicate that ERbetaDelta5 has a potential as a dominant negative receptor that blocks both ERalpha and ERbeta signaling pathways, suggesting some physiological roles of this isoform as an "ER inhibitor".

Prevention of paraplegia in transluminally placed endoluminal prosthetic grafts for descending thoracic aortic aneurysms

OBJECTIVE

To evaluate the efficacy of a temporary balloon occlusion test for the prevention of paraplegia following transluminally placed endoluminal prosthetic grafts for descending thoracic aortic aneurysms.

SUBJECTS AND METHODS

Two occlusion balloons were inserted via the brachial and femoral arteries and positioned in the proximal and distal neck of the descending thoracic aortic aneurysms using fluoroscopy. After temporary occlusion of the thoracic aorta by inflation of both the proximal and distal balloons, the evoked spinal potential was measured for 15 mins. A maximum amplitude during temporary balloon occlusion test decreasing by more than 20% of the pre-balloon occlusion level was considered to be significant, enough to not perform transluminally placed endoluminal prosthetic grafts, but instead an open repair. The test was applied in 12 cases (9 males and 3 females, 50-86 years old). All aneurysms were located between the Th6 and Th12 with a maximum diameter of 40-70 mm, and average of 56 mm.

RESULTS

The changes in maximum amplitude of evoked spinal potential remained within 20% of the value before balloon occlusion in 11 cases. Transluminally placed endoluminal prosthetic grafts were performed in these 11 cases and no instance of paraplegia or other complication relating to the test was observed. Deployment of stent-grafts was successful in 10 cases (91%).

CONCLUSION

It is suggested that the preoperative measurement of evoked spinal potential during temporary balloon occlusion is clinically useful for the assessment of the risk to paraplegia occurring in transluminally placed endoluminal prosthetic grafts.

[Effect of low dose aprotinin on reduction of blood loss after extracorpreal circulation]

Aprotinin administration during open heart surgery has been reported to reduce blood loss after extracorporeal circulation (ECC). We administered aprotinin to 12 patients undergoing CABG or prosthetic valve replacement. We examined the blood loss, the coagulation, and the fibrinolytic system in comparison with that in non-aprotinin group of 12 patients. In the aprotinin group, 1,000,000 units of aprotinin was infused intravenously before initiation of ECC and mixed with priming volume of ECC. After ECC, 250,000 units/hr was continuously infused until 1 hour after operation. The aprotinin group showed a significantly enhanced level of alpha 2 plasmin inhibitor and a significantly reduced level of plasmin-alpha 2 plasmin inhibitor complex and D-dimer. Post operative blood loss was not different between two groups. Operation time and closure time after heparinneutralization was shorter and postoperative blood use was lower in the aprotinin group. In conclusion, The administration of low dosed of aprotinin suppresses the fibrinolytic system resulting in the reduction of operation and closure time.

Regression of left main coronary ostium stenosis after surgical revascularization and steroid therapy

We describe a patient in whom stenosis of the left main coronary ostium completely regressed after steroid treatment following surgical revascularization. A 46-year-old woman with unstable angina underwent double coronary artery bypass grafting. Although she did not fulfill diagnostic criteria for Takayasu's disease, we began postoperative steroid therapy on postoperative day 14 based on clinical manifestations and histological findings. Coronary angiography 33 days after surgery showed the ostial stenosis of the left main coronary artery had disappeared. Steroid therapy for suspected Takayasu's disease should be considered even after surgical revascularization.

Effect of Water-Soaking and Air-Drying on Survival of Aphelenchoides besseyiinOryza sativa Seeds

Several nematicides have been used to disinfest rice seeds contaminated with the white tip nematode, Aphelenchoides besseyi. We measured the efficacy of a standard disinfestation treatment that consists of soaking seeds in an aqueous emulsion of fenitrothion or fenthion and subsequently air-drying the seeds. We also measured the efficacy of the same treatments but without addition of nematicide to the soak water. Viability was monitored at key points during treatment. Our results showed that nematicides alone caused little nematode mortality within seeds. Most mortality occurred while seeds were being air-dried. Mortality caused by air-drying alone was 1.7 times greater than mortality caused by soaking seeds in water for 24 hours.

Significance of lung resistance-related protein in the clinical outcome of acute leukaemic patients with reference to P-glycoprotein

Lung resistance-related protein (LRP) overexpression in leukaemic blast cells from acute leukaemia patients and the effect of LRP or P-glycoprotein (P-gp) on the clinical outcome of acute leukaemia were investigated individually by dividing patients into four groups. The complete remission rate of group I (LRP and P-gp both negative) was 81.7%, group II (only LRP positive) 87.5%, group III (only P-gp positive) 87.1% and group IV (LRP and P-gp both positive) 40.0%. There were no statistical differences between group I and groups II or III, but a significant difference was observed between groups I, II or III and group IV. Median overall survival in group IV was significantly shorter (4.6 months) than in groups I, II or III, although no significant differences were observed between group I and groups II or III (18.9, 20.5 and 31.8 months). There was a tendency for disease-free survival in group III to be longer than that in groups I, II or IV. The reasons for these findings are discussed. Our present results indicate that the co-existence of LRP and P-gp strongly influenced the effectiveness of induction chemotherapy and long-term prognosis, whereas the isolated presence of LRP or P-gp did not.

Immunohistochemical staining of dystrophin on formalin-fixed paraffin-embedded sections in Duchenne/Becker muscular dystrophy and manifesting carriers of Duchenne muscular dystrophy

We succeeded in immunostaining of monoclonal anti-dystrophin antibodies on formalin-fixed and paraffin-embedded muscle sections from patients with Duchenne muscular dystrophy, patients with Becker muscular dystrophy, and manifesting carriers of Duchenne muscular dystrophy using Catalyzed Signal Amplification(TM) system. The Catalyzed Signal Amplification system is an extremely sensitive immunohistochemistry staining procedure based on the peroxidase-catalyzed deposition of a biotinylated phenolic compound. We used three mouse monoclonal antibodies: DYS1, DYS2, and DYS3. Muscle sections were treated using the Target Retrieval Solution(TM) and the Catalyzed Signal Amplification system. In control patients, DYS1 and DYS2 were stained at the sarcolemma, but DYS3 remained unstained. In Duchenne muscular dystrophy patients, DYS1 and DYS2 staining were undetected. In Becker muscular dystrophy patients, the immunolabeling of DYSI and DYS2 were weak and discontinuous. In manifesting carriers of Duchenne muscular dystrophy, DYS1 and DYS2 staining showed a mosaic pattern of dystrophin-positive fibers and dystrophin-negative fibers. DYS1 and DYS2 staining patterns of this study are similar to those of frozen sections using conventional methods previously reported. In cases from whom frozen muscle sections cannot be obtained, immunohistochemical dystrophin analysis using the Catalyzed Signal Amplification system will be beneficial for the diagnosis and the screening of neuromuscular diseases.