A two-color dual-comb system for time-resolved measurements of ultrafast magnetization dynamics using triggerless asynchronous optical sampling

We report on an Er-doped fiber (EDF)-laser-based dual-comb system that allows us to perform triggerless asynchronous optical sampling pump-probe measurements of ultrafast demagnetization and spin precession in magnetic materials. Because the oscillation frequencies of the two frequency-comb light sources are highly stabilized, the pulse-to-pulse timing jitter is sufficiently suppressed, and data accumulation without any trigger signals is possible. To effectively induce spin precession in ferromagnetic thin films, the spectral bandwidth of the output of one of the EDF frequency comb sources is broadened by a highly nonlinear fiber and then amplified at a wavelength of about 1030 nm by a Yb-doped fiber amplifier. The output of the other frequency comb source is converted to about 775 nm by second harmonic generation. We used this system to observe ultrafast demagnetization and spin precession dynamics on the picosecond and nanosecond time scales in a permalloy thin film. This time-domain spectroscopy system is promising for the rapid characterization of spin-wave generation and propagation dynamics in magnetic materials.

Midterm outcome of total hip arthroplasty for rapidly destructive coxarthrosis

PURPOSE

To compare the midterm outcome in 12 women who underwent total hip arthroplasty (THA) for rapidly destructive coxarthrosis (RDC) and in 12 controls who underwent THA for osteoarthritis.

METHODS

Records of 12 women aged 50 to 80 (mean, 72.3) years who underwent THA for RDC after a mean of 9 (range, 4-11) months since symptom onset were reviewed. They were compared with 12 age-and sex-matched controls who underwent THA for primary or secondary osteoarthritis. Acetabular bone deficiency of the 12 RDC patients was classified as type I (n=7), type II (n=4), or type III (n=1). Type I was treated with cementless THA, and types II and III were treated with THA with a cemented acetabular component. The femoral component was cementless. Pre- and post-operative Harris Hip Score was assessed. Radiographs of the hip were evaluated for implant migration, osteolysis, and periprosthetic radiolucency in the acetabulum and proximal femur.

RESULTS

The 12 women who underwent THA for RDC and the 12 controls who underwent THA for osteoarthritis were comparable in terms of pre-, intra-, and post-operative parameters. After a mean follow-up of 9.3 years, the mean Harris Hip Score improved from 38.3 to 81.1 in RDC patients and from 43.6 to 84.2 in controls (p=0.13). One RDC patient had dislocation but did not require revision surgery. One RDC patient developed a radiolucent line <2 mm in zones 1 and 7 of the femoral component, but no migration occurred. No patient had progression of bony destruction, loosening, osteolysis, migration, or radiolucency of the acetabular component.

CONCLUSION

Despite the rapid destruction of the acetabulum and femoral head in RDC patients, cemented or cementless THA achieved a good midterm outcome comparable to that for patients with primary or secondary osteoarthritis.

[Surgical fixation for flail chest]

Flail chest occurs by blunt chest trauma and is associated with pulmonary contusion, atelectasis, pneumothorax, hemothorax, and respiratory failure. Because of its severity, it may need internal pneumatic stabilization or surgical fixation. Some patients do not need the internal stabilization and are observed conservatively. Some of these patients, however, increase the flail after palliating the pain and getting up. These patients show inefficient ventilation and surgical fixation is needed. The operation should be performed after the improvement of pulmonary contusion. In this paper, we presented 2 patients who showed such course and clarified the surgical methodology.

Rotational acetabular osteotomy for acetabular dysplasia

Between 1986 and 1990, we carried out 55 rotational acetabular osteotomies in 54 patients with acetabular dysplasia. Five hips were lost to follow-up. Of the 50 remaining, the degenerative changes were classified according to the criteria of Tönnis as grade 0 in 23, grade 1 in 16 and grade 2 in 11. The mean age of the three men and 46 women at the time of operation was 31.8 years (13 to 53). The mean follow-up was 137 months (120 to 174).

At the most recent follow-up, 48 patients had satisfactory relief from pain. There was a slight decrease in the range of movement, particularly of flexion, in 18 hips. Radiologically, all osteotomies had united satisfactorily. There was radiological evidence of improvement in degenerative changes in 13 hips (5 grade 1 and 8 grade 2). Ten deteriorated (5 grade 0, 3 grade 1, and 2 grade 2) and one required total hip arthroplasty ten years after osteotomy. The osteoarthritis in the two hips with an associated valgus osteotomy progressed. The changes in radiological indices such as the centre-edge angle, acetabular femoral head index, acetabular root obliquity and horizontal or vertical displacement of the femoral head showed no statistical difference (unpaired Student’s t-test) between the patients with radiological progression and those with and without improvement.

Rotational acetabular osteotomy for severely dysplastic acetabulum

The operative procedures chosen for arthrosis with severe acetabular dysplasia vary among orthopaedic surgeons. We operated on 250 hips using the rotational acetabular osteotomy (RAO) method of Ninomiya and Tagawa [8]. In this report, we describe the technique of RAO and the results of this procedure in patients with severely dysplastic hips. Among the 250 hips, there were 6 which were classified as Severin group V. In those hips, the CE angle was less than 0 degrees, and the femoral head showed superolateral subluxation. After acetabular osteotomy with straight and curved osteotomes, smooth inferolateral rotation could be done in all cases. At the latest follow-up symptoms were improved remarkably, especially pain. Radiographically, adequate coverage of the femoral head was achieved and joint congruence improved in all 6 hips.

False aneurysm of the profunda femoris artery after total hip arthroplasty

A false aneurysm of the profunda femoris artery occurred after metal-on-metal total hip arthroplasty in 70-year-old woman. At 39 days after the operation, the wound suddenly opened, and a large hematoma was discharged. Eleven tornade coils were inserted into the base of the false aneurysm, and the bleeding was arrested. The prevention and management of this complication are discussed.

The usefulness of conducting investigations on intra-abdominal bacterial contamination in digestive tract operations

A bacteriological study of 108 cases of gastrointestinal surgery was conducted by analyzing intra-abdominal bacterial contamination (IABC) and postoperative surgical site infections (SSI). We utilized an anaerobic porter to detect intra-abdominal bacterial infection and transport bacteria to the laboratory. The positive IABC rate was 42.9% for gastric cancer surgery, 22.6% for biliary tract surgery, and 85.7% for colorectal cancer surgery. Most cases of SSI were IABC-positive, and isolated bacterial species from the SSI were similar to those from the IABC. In colorectal cancer surgery, a preoperative chemical intestinal preparation and the prophylactic use of antibiotics had a major influence on the sensitivity of bacteria isolated from the SSI. These data suggest that prophylactic antibiotics should be chosen from among those to which bacteria from the IABC are highly sensitive, and that therapeutic antibiotics should be chosen from among those to which bacteria isolated from the SSI are highly sensitive. Finally, the exploration of IABC enables us to predict the incidence of SSI.

Pharmacokinetic properties of YM17E, an inhibitor of acyl coenzyme A: cholesterol acyl transferase, and serum cholesterol levels in healthy volunteers

We conducted a single and repeat oral dose study of YM17E, a novel inhibitor of acyl coenzyme A (CoA): cholesterol acyltransferase, in healthy male volunteers to evaluate the pharmacokinetic profile, tolerability and effect of the drug on serum cholesterol. In the single administration study, YM17E was administered after a meal to two groups of subjects (each containing six subjects taking the drug and three taking placebo) receiving 3, 60 and 300 mg or 15, 60 and 450 mg YM17E, respectively. Plasma concentrations of unchanged drug following single oral administration at 3-300 mg after a meal increased with increasing dose. In contrast, plasma concentrations after administration of 450 mg were almost the same as after 300 mg. Unchanged YM17E was not detected in urine after single administration, suggesting that it was excreted via the bile or urine after metabolism. Five active metabolites (M1, M2-a, M2-b, M3 and M4) were observed in plasma at concentrations comparable to those of unchanged YM17E. Their plasma concentrations increased in a slightly greater than dose-dependent manner from 3 to 300 mg. The effect of food was studied in an open crossover design with a 1-week washout period. Twelve subjects received 150 mg YM17E in both the fasted and post-prandial states. The AUC and Cmax after fasting were closely similar to those after a meal, showing that bioavailability was not affected by food intake. In the repeated oral dose study, the subjects received test drug at 150 mg or 300 mg (n = 6 each) or placebo (n = 3) twice a day (after breakfast and after dinner) for 7 days. On days 1 and 7, the subjects received YM17E once a day (after breakfast) for evaluation of pharmacokinetic properties. After repeated oral administration of 150 mg b.d., plasma concentrations reached steady state by day 5 (mean Cmin 48.6 ng.ml-1). After repeated administration of 300 mg b.d., plasma concentrations prior to each daily morning dose increased up to the 5th day (mean Cmin 166.6 ng.ml-1) and then tended to decrease until the 7th day. No significant signs, symptoms or changes in serum cholesterol levels were observed during the single and repeated oral dose studies at 150 mg b.d. Although statistical analysis was not conducted because of the small number of subjects, all subjects receiving repeated oral administration of 300 mg twice daily showed a 25% decrease in serum cholesterol level on day 7, but also the simultaneous occurrence of diarrhoea.

Mouse-human chimeric antibody MH171 against the multidrug transporter P-glycoprotein

We have developed a mouse-human chimeric antibody MH171, in which the antigen-recognizing variable regions of the mouse monoclonal antibody MRK17 are joined with the constant regions of human IgG1 antibodies. The MRK17 recognizes specifically the multidrug transporter P-glycoprotein and inhibits the growth of human multidrug resistant (MDR) tumor cells in vitro and in the xenograft nude mouse model system. The established chimeric MH171 antibody forms an apparently intact IgG composed of heavy and light chains covalently assembled via disulfide bonds in sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis and is specific to MDR cell lines with a similar affinity to the original mouse MRK17. MH171 also displays strong antibody-dependent cell-mediated cytotoxicity to the target cells in vitro, when human mononuclear cells are used as effector cells. The chimeric antibody against P-glycoprotein, MH171, should be a useful agent in the treatment of human drug-resistant tumors.

[Effects of test-expectancies and test-sequence orders on the recognition failure of recallable words]

Two experiments examined the effects of test-expectancies and test-sequence orders on the phenomenon of recognition failure. In Experiment 1, 18 college students, half of which were male and the other half were female, were randomly divided into two experimental groups. Half of the subjects studied the 42 cue word-target pairs in anticipation of a cued recall test, while the remaining subjects studied the pairs in anticipation of a recognition test. In Experiment 2, 36 college students (18 male and 18 female students) were randomly divided into two experimental groups. Half of the subjects were tested successively, first for recognition and then for recall, and the remaining subjects were tested in the reverse order. The results showed that the magnitude of recognition failure decreased when the subjects expected the recognition test. There were no appreciable sequential testing effects on the magnitude of recognition failure, however. These results imply that the phenomenon of recognition failure is not an artifactual one in the recognition-recall testing order, and that the magnitude depends on encoding conditions.