U-shape rotating anti-cathode compact X-ray generator: 20 times stronger than the commercially available X-ray source.

A new type of U-shape anti-cathode X-ray generator in which the inner surface of a cylindrical target is irradiated by an electron beam has been made by modifying a conventional rotating anti-cathode X-ray generator whose brightness in the catalog is 12 kW mm(-2). The target material (Cu), target radius (50 mm) and rotating speed (6,000 r.p.m.) were not changed in this modification. A brightness of 52 kW mm(-2) was obtained by this U-shape-type X-ray generator. This means that the brightness of the new type is 4.3 times greater than that of the old unmodified one. Furthermore, the new-type X-ray generator yielded a brightness of 129 kW mm(-2) by adding a carbon coating on the Cu target. This means an overall increase of brightness of ten times. The original generator has the highest brightness in the generators of the same class (having a radius of 50 mm and rotation speed of 6,000 r.p.m.). Observations showed that Cu Kα counts at vertical incidence of the electron beam onto the surface of the new target, which is initially optically smooth, decrease as the surface is roughened by a severe thermal stress caused by strong electron beam exposure. Further observation reveals, however, that oblique incidence of the electron beam onto the roughened surface drastically increased the X-ray output and amounts to twice as much as that from a smooth surface at vertical incidence. Thus, at the present stage, an overall increase of brightness has been realised at a level 20 times stronger than that of the original commercially offered X-ray generator that we modified.

Caspase-mediated changes in histone H1 in early apoptosis: prolonged caspase activation in developing olfactory sensory neurons.

Programmed cell death or apoptosis is required for the patterning and development of multicellular organisms. However, apoptosis is a difficult process to measure because the dead cells are rapidly degraded by their neighbors within a few hours. The post-caspase activation events that determine whether a cell will undergo apoptosis remain elusive. Here we report that apoptosis-specific nuclear events that occur before DNA fragmentation can be distinguished by monitoring the histone H1 status. In both mammals and Drosophila, dying cells failed to be immunolabeled with an anti-H1 monoclonal antibody, AE-4. Real-time imaging of caspase activation and H1 dynamics in mammalian neural cells revealed that H1 changed its location in the nucleus after caspase activation. In addition, the timing of this re-localization was largely dependent on the apoptotic stimulus used. From the staining patterns of AE-4 and anti-active caspase-3 antibodies, cells undergoing the transition from caspase activation to the apoptotic H1 change could be identified as H1-positive caspase-activated cells, providing a novel criterion for early apoptosis and making it possible to characterize caspase-activated cells in tissues. On the basis of these staining patterns, we found that many olfactory sensory neurons in the developing mouse olfactory epithelium showed sustained caspase activity without the H1 change, suggesting a unique caspase function in these neurons.

Highly bright X-ray generator using heat of fusion with a specially designed rotating anticathode.

A new type of rotating anticathode X-ray generator has been developed, in which the electron beam irradiates the inner surface of a U-shaped anticathode (Cu). A high-flux electron beam is focused on the inner surface by optimizing the shape of the bending magnet. The power of the electron beam can be increased to the point at which the irradiated part of the inner surface is melted, because a strong centrifugal force fixes the melted part on the inner surface. When the irradiated part is melted, a large amount of energy is stored as the heat of fusion, resulting in emission of X-rays 4.3 times more brilliant than can be attained by a conventional rotating anticathode. Oscillating translation of the irradiated position on the inner surface during use is expected to be very advantageous for extending the target life. A carbon film coating on the inner surface is considered to suppress evaporation of the target metal and will be an important technique in further realization of highly bright X-ray generation.

Medical rehabilitation of the patients with spinal cord injury caused by aortic aneurysm and its operation.

OBJECTIVES: To determine the natural course of spinal cord injury (SCI) after aortic aneurysm surgery. SETTING: Acute care and semi-acute wards in Osaka Rosai Hospital, Japan. METHODS: From 1998 to 2003, 12 patients with thoracic SCI (eight men and four women; mean age: 69 years) were enrolled and evaluated by the American Spinal Injury Association (ASIA) impairment scale and Functional Independence Measure (FIM), and the results were analyzed. RESULTS: The level of SCI was distributed from T5 to L1. The ASIA impairment scale was A in four patients, B in four, C in three and D in one. Finally, six patients were discharged to home, and two patients died during hospitalization. Excluding the value of the deceased patients, the mean motor FIM was initially 32+/-15.6 (13-59) points and became 61+/-21.4 (29-88) points at discharge. Referencing the databases of SCI in Japan and USA revealed that the complication rates of pneumonia and aspiration were higher in our cases. The motor FIM before rehabilitation and at discharge were relatively lower than in the databases, but the gain and the rate of gain were similar to the Japanese database. CONCLUSION: SCI associated with aortic aneurysm surgery was noticed especially in the elderly patients using airways (for example, tracheostomy). The higher age and recurrent nerve palsy were associated with deconditioning state to develop aspiration pneumonia. This state impaired the general condition, and such vicious cycle led to poor prognosis and functional outcome.

Measurement of positron production efficiency from a tungsten monocrystalline target using 4- and 8-GeV electrons.

Intense positron sources are being widely investigated for the next-generation linear colliders and B factories. A new method utilizing an axially oriented crystal as a positron-production target is one of the bright schemes, since it provides a powerful photon source through channeling and coherent bremsstrahlung processes when high-energy electrons penetrate the target. A series of positron-production experiments with tungsten crystals hit by 4- and 8-GeV single-bunch electron beams were carried out at the KEKB 8-GeV injector linac. Three tungsten crystals with different thicknesses (2.2, 5.3, and 9.0 mm) and those combined with amorphous tungsten plates were tested on a precise goniometer. The positron-production yields were measured with a magnetic spectrometer in the positron momentum (P(e(+))) range from 5 to 20 MeV/c. The angle of the <111> crystal axis with respect to the electron-beam direction was controlled by measuring the relative intensities of the produced positrons as a function of the rotational angle of the goniometer. The results show that the enhancements of the positron yield from crystal targets compared to amorphous targets of the same thickness at P(e(+))=20 MeV/c are from 1.5 to 3.7 and from 1.8 to 5.1, depending upon the target thickness for 4- and 8-GeV electrons, respectively.

A report of two cases treated with Pauwels' femoral osteotomy for advanced osteoarthritis resulting from a sequela of infectious coxitis in childhood.

Pauwels' femoral valgus osteotomy was performed on two osteoarthritic hips that developed as a sequela of infectious coxitis in the childhood. One of the hips was diagnosed as osteomyelitis of the ipsilateral femur before the operation and was treated with curettage and implantation of antibiotic-impregnated cement beads. The results of both hips were excellent and maintained for 9-11 years.

[Valvular heart surgery in osteogenesis imperfecta].

Osteogenesis imperfecta is a disease in which fragile bones readily cause fracture. Valvular disease concurrently develops. However, the surgery-related mortality rate is approximately 30%. In this study, we report 2 patients with osteogenesis imperfecta who underwent valvular heart surgery. Patient 1 was a 31-year-old male. He had previously been diagnosed as having osteogenesis imperfecta. Echocardiography suggested aortic valve insufficiency, and aortic valve replacement was performed. Patient 2 was a 59-year-old male. During admission, osteogenesis imperfecta was diagnosed. Echocardiography suggested mitral valve insufficiency, and mitral valve plasty was performed. In the 2 patients, intraoperative hemorrhage was marked. However, there were no fatal complications. We also reviewed the literature.

Lower lip-lifting brace for bilateral facial nerve palsy: a case report.

A 55-year-old man suffered from pontine hemorrhage 5 years before he visited our outpatient clinic with complaints of gait disturbance and dysphagia. At the first examination, his inability to close his mouth, eyes, and lower lip led to the diagnosis of facial diplegia. He was instructed to wear a gauze surgical mask and to use artificial saliva for his xerostomia. A videofluorogram of his swallowing excluded aspiration but revealed dysphagia attributable to neck hyperextension arising from efforts to prevent food spilling from his mouth. We prescribed a brace to lift his lower lip as a treatment of his dysphagia. This brace covered his chin to support his lower lip. Our brace resulted in improved function; liquids no longer leaked from his mouth and because the lip elevation eliminated his xerostomia, he no longer required artificial saliva or the gauze mask.

Aortic valve repair in dominant aortic regurgitation.

OBJECTIVE: We studied immediate and mid-term results after aortic valve repair. METHODS: Immediate and mid-term results were studied in 63 patients undergoing aortic valve repair, calculating survival and reoperation free rates. RESULTS: Subjects were 49 men and 14 women aged 15 to 76 years (mean: 53 +/- 17 years). Mean preoperative aortic regurgitation grading of 1 to 4 was 3.2 +/- 0.7. Mean preoperative New York Heart Association functional class was 1.9 +/- 0.8. Two in-hospital deaths occurred. (3.2%) Mean aortic regurgitation grade at discharge was 1.3 +/- 0.8 (p < 0.0001; vs preoperative grade) and functional class was 1.1 +/- 0.2 (p < 0.0001; vs preoperative class),--significantly improved. Overall follow-up was 98.4%, and mean follow-up continued 41.4 +/- 22.1 months. Mean functional class at follow-up was 1.2 +/- 0.4 (n = 49), improved from preoperative class (p < 0.0001). Mean aortic regurgitation grading at follow-up was 1.8 +/- 0.8 (n = 41), improved from preoperative grading (p < 0.0001). Five-year survival was 95.1 +/- 2.8%. One-year reoperation freedom was 96.6 +/- 2.4% and 5-year 77.9 +/- 6.9%. CONCLUSIONS: Survival after surgery was good, while reoperation was comparable to other reports but less satisfactory compared to reoperation freedom after aortic valve replacement. Based on reoperative findings, a change in indication was made. We believe technical refinements could improve postoperative results.

Lower limb amputation for diabetic foot.

We amputated 35 limbs of 27 patients with diabetic foot from March 1988 to March 1998. The mean age of the patients at the time of operation was 67 years, and the mean follow-up period was 27 months. Thirteen patients died in the period from 1 day to 39 months after the operation. All patients suffering from diabetic foot were referred to our department for surgical procedures after failure of conservative treatment conducted elsewhere. Their feet were classified into grade 2-3 in 18 limbs, grade 4-5 in 11 limbs, and gangrene of the lower leg and entire foot in 2 limbs, as classified by the Wagner system. Two patients had cellulitis of the foot and two other limbs had infectious gonarthritis. All patients had type 2 diabetes with poor blood sugar control, and 90% were treated by insulin. All patients suffered from diabetic neuropathy. Half of the patients were put on hemodialysis because of diabetic nephropathy. More than 60% of the patients suffered from arteriosclerosis obliterans. The amputation level of the limb was determined by skin thermography, but the patient's will was critical. The initial amputation levels were: débridement and synovectomy in 4 limbs, toe and digital ray in 15 limbs, transmetatarsal in 3 limbs, transtibial in 9 limbs, transfemoral amputations in 4 limbs. Upper level reamputation was conducted on 15 limbs. Logistic regression analysis revealed that lower temperature of the amputation site, being female, and being elderly were significant risk factors in reamputation. Skin thermography was one of the effective determinants of amputation level, in order to avoid reamputation.

Midline retroperitoneal versus midline transperitoneal approach for abdominal aortic aneurysm repair.

PURPOSE: The purpose of this study was to compare the midline retroperitoneal approach with the midline transperitoneal approach for abdominal aortic aneurysm (AAA) repair with respect to operative details, gastrointestinal complications, and wound complications. METHODS: From January 1990 through January 1998, 128 patients underwent elective aortic reconstruction for infrarenal AAA. Of these, 64 patients (the transperitoneal group) underwent conventional transperitoneal midline aortic exposure, whereas the remaining 64 patients (the retroperitoneal group) underwent retroperitoneal midline exposure of the aneurysm. RESULTS: Preclamp time, that is, the time from skin incision to aortic clamping, was significantly shorter in the transperitoneal group than in the retroperitoneal group (P <.001). However, the midline retroperitoneal approach was associated with decreased incidence of ileus (P <.01), earlier resumption of oral intake (P <.01), and decreased wound pain (P <.01), in comparison with the transperitoneal approach. Furthermore, there was no incidence of wound complications such as abdominal bulge or wound pain in any of the patients in the postoperative period or over the long term. CONCLUSIONS: The midline retroperitoneal approach for AAA was associated with fewer postoperative gastrointestinal and wound complications than the midline transperitoneal approach. Over the long term, there was no wound complication such as abdominal bulge and wound pain in any of the patients.

Factors influencing joint-preserving operations in the treatment of the late stages of osteoarthritis of the hip.

Between November 1983 and December 1992, 136 hips (119 patients) with coxarthritis were operated on using joint-preserving techniques based on the rationale of Pauwels' osteotomy. The criterion for selection was a patient in whom the height of the joint space in the weight-bearing area of the hip was less than 1 mm. The mean age at operation was 48 years and the mean follow-up 109 months (60 to 171). Hips were categorised using Bombelli's classification of osteoarthritis, into atrophic and non-atrophic types. The endpoint was defined as that at which the height of the joint space became less than 1 mm again. The Kaplan-Meier curve showed that the rate of survival of the non-atrophic group was significantly better than that of the atrophic group. Cox's proportional hazard model indicated that the factors influencing the results of joint-preserving operations included Bombelli's classification, postoperative incongruence of the joint and the height of the joint space.

Detection of hepatocellular carcinoma and its metastases with various pulse sequences using superparamagnetic iron oxide (SHU-555-A).

BACKGROUND: To identify the most useful combinations of various pre- and postcontrast magnetic resonance (MR) image sequences in detecting hepatocellular carcinoma (HCC) and its intrahepatic metastases before and after injection of SHU-555-A. METHODS: Thirty-eight lesions in 16 patients were evaluated before and after administration of SHU-555-A by using fast spin echo (FSE), gradient echo (GRE), and echo planar (EP) imaging sequences using a 1.5-Tesla superconducting MR system. The signal intensity ratio (SIR) and contrast-to-noise ratio (CNR) of the lesions, signal-to-noise ratios, and other parameters were calculated. RESULTS: Tumors were better detected after injection of SHU-555-A on all pulse sequences except on out-of-phase T1-weighted (T1W)-GRE sequences. Tumor detectability was higher for precontrast EP imaging and T2*-weighted (T2*W)-GRE sequences, whereas detectability at postcontrast was higher for T2*W-GRE, proton-density-weighted-FSE, and in-phase T1W-GRE sequences. The SIR and CNR at precontrast were highest for EP imaging, and those at postcontrast were highest for T2*W-GRE. CONCLUSION: SHU-555-A will increase the detectability of HCC and its liver metastases. T1W- and T2*W-GRE sequences would be the sequences of choice.

Postoperative renal function after an abdominal aortic aneurysm repair requiring a suprarenal aortic cross-clamp.

We describe herein the postoperative renal functions of patients who required a suprarenal aortic cross-clamp during abdominal aortic surgery. Seven patients required a unilateral suprarenal aortic cross-clamp (group A) and six patients required a bilateral suprarenal clamp (group B). Eighty-three patients who required an infrarenal aortic clamp were assigned to group C. Renal hypothermia with renal perfusion or topical cooling during suprarenal clamp was not performed. No hospital deaths were encountered. In group B, the postoperative creatinine and blood urea nitrogen (BUN) levels remained statistically significantly higher than that of group C until the seventh postoperative day. The postoperative renal dysfunction (serum creatinine level >2.0 mg/dl) was 28.6% in group A and 50% in group B, while it was only 8.4% in group C, although no patient required either temporary or permanent hemodialysis. The postoperative peak BUN over 30 min suprarenal clamp was significantly higher than that within 30 min. In summary, the postoperative renal function was impaired after an extended bilateral suprarenal clamp. These findings suggest that if prolonged renal ischemia is thus expected, then renal preservation should be considered.

High-Fat diet enhances accumulation of hexachlorobenzene in rat dams and delays its transfer from rat dams to suckling pups through milk.

Effect of diets on the distribution and transfer of hexachlorobenzene (HCB) from dams to fetuses and suckling pups was investigated. In pregnant rats, the amount of HCB accumulated in fat tissues of the high-fat diet group was higher than that of the control diet group (P < 0.05). The amounts of HCB in fetuses of the high-fat and control diet groups were estimated to be about 0.28 and 0.12% of the dam's total intake during pregnancy, respectively. In both groups, a large proportion of HCB in dams disappeared during lactation period and was transferred to their pups through the milk. In the pups of the high-fat diet group, the amount of HCB in stomach contents was lower immediately after birth and decreased slowly compared with that in the control diet group during lactation. These results showed that a high-fat diet reduced the speed of the transfer of HCB from the dams to their suckling pups through milk.

Evaluation of effect and distribution of heparin administered in vascular reconstructive surgery.

BACKGROUND: The aim of this study was to find out whether intravenously administered heparin is distributed equally not only proximal but also distal to the arterial occlusion level in vascular reconstructive surgery. METHODS: Ten consecutive patients (7 men and 3 women) with an average age of 69.9 years (range, 51 to 76 years) who underwent graft replacement for aortic abdominal aneurysm from April to December 1994 were studied. Mean aortic clamp time was 76 minutes. Heparin sodium (100 U/kg) was administered intravenously to keep activated clotting time (ACT) over 250 secs and was neutralized by protamine sulfate (1 mg/kg) just after reperfusion. ACT, blood lactate and CPK-MM in the brachial and dorsal pedis artery were measured before heparin administration (control), just after arterial occlusion, just before reperfusion and 10 minutes after protamine administration. RESULTS: ACT was significantly prolonged after arterial occlusion and recovered after protamine administration with no significant differences between proximal and distal values at each point. Lactate showed significant increase after arterial occlusion which was more remarkable distally. CPK-MM was all the way within the normal range. CONCLUSIONS: In vascular reconstructive surgery which requires temporary arterial occlusion for as long as 80 minutes, the effect of heparin is excellent and equal throughout the body by collateral vessels, and the metabolic influence due to blockade of the blood flow is not so critical as to lead to cellular damage although anaerobic glycolysis is promoted distally due to hypoxia.

Dynamic MR imaging of the carotid wall.

The purpose of this study was to clarify temporal changes of carotid wall enhancement using dynamic magnetic resonance (MR) and to correlate its findings with pathological conditions. Cervical carotid arteries of 84 consecutive patients were studied with a 1.5 T MR imager using phased array coils. Axial spoiled gradient-echo (SPGR) images (30-58 second scan time) with fat saturation were repeated 4-8 times after the injection of contrast material. We evaluated the presence and thickness of hypointense inner rims and hyperintense outer rims of the carotid wall, temporal changes of outer rim enhancement, and their changes in relation to pathological conditions. Hypointense inner rims and enhanced outer rims were clearly visualized in 87% (73/84) of our subjects. Enhancement of the outer rim was minimal in early phases and gradually increased. Patient age had a significant correlation with outer rim thickness. In the portions with large atheromatous plaques, inner rims were disrupted or thickened. A marked thickening of the outer rim was observed in one patient with arteritis. The outer rims adjacent to malignant tumors were often obscured. Our study suggests that dynamic MR images of the cervical carotid artery can uniquely demonstrate angiogenesis of the wall itself. The outer rim of the artery shows relatively rapid enhancement, and its thickness correlates with age.

Validation of a microwave sterilizer for injection ampules.

A program for validating the microwave sterilizer, which is a new type of sterilizer, was established and implemented. This program includes the following tests specific to microwave sterilizers: the internal pressure strength of ampules, the acceptable range of sterilizing temperature, performance and calibration of the infrared thermometer and the plane blackbody, maintaining of sterilizing temperature, the processing speed (sterilizing time), the unacceptable ampules selection mechanism, microwave leaks, and a microbiological challenge test of the ampule head space using a biological indicator. Injectable preparations of mecobalamin and diprophylline were used as models for validation of the microwave sterilizer. The bioburden approach was used for injectable mecobalamin preparation, and the over-kill approach was used for injectable diprophylline preparation. The basis for practical use of this microwave sterilizer has been confirmed by the establishment and implementation of this validation program.

Middle-term results of anatomic medullary locking total hip arthroplasty.

We report the results of cementless, anatomic, medullary locking hip prosthesis application in our first consecutive series. We used the so-called Asian size of prosthesis with proportionally smaller stem sizes in both diameter and length. Forty-seven stems and sockets were analyzed with a mean follow-up of 69 months. The mean Merle d'Aubigné hip scores were 8 points preoperatively and 16 points at the final follow-up. Radiologically, the stems showed excellent stability without loosening. Stress shielding around the stems did occur in most cases but did not progress. Preoperative bone quality influenced the extent of stress shielding evaluated at the final follow-up: higher stress shielding was noted in poorer quality bones at the time of operation. There were problems with the sockets. The shallow socket and impingement at the protruded rim seemed to cause a high incidence of dislocation (13%). Massive polyethylene wear occurred in 5 sockets. These sockets were 48 and 46 mm in diameter with 26 mm heads. In conclusion, the stems of the anatomic medullary locking hip prostheses used in Japan showed satisfactory stability even in poor quality bones, but there were problems with the polyethylene liners. Our solution was to use larger sockets with 22 mm heads.